Indian J Exp Biol

FEBRUARY 2002

CODEN: IJEB (A6)  40(1)  123-238  (2002)

ISSN: 0019-5189

 

 

 

Indian Journal of Experimental Biology

http : // www.niscom.res.in; http : // www.bioline.org.br/

VOLUME 40

NUMBER 2

FEBRUARY 2002

 

CONTENTS

 

Review Article

Phospholipase A2-activating protein ¾ An important regulatory molecule in modulating cyclooxygenase-2 and tumor necrosis factor production during in­fl­a­m­­ma­­tion

Deborah A Ribardo, Johnny W Peterson & Ashok K Chopra

 

129

 

 

Papers

 

Peripheral nerve connections influence the appearance of neurosecretary material in neural sheath of ventral ganglion of the fly Sarcophaga bullata: An immunocytochemical study

P Sivasubramanian & Prem Prakash Sood

 

 

139

 

 

Induced liver tumour further support to a genetic marker with its high correlation with chorioallantoic membrane phenotypes in selected layer lines

A K Ghosh & P K Pani

 

144

 

 

Protein mediated cholesterol absorption in locusts Schistocerca gregaria (Forskal) and Locusta migratoria (Linn)

Ravi Kant Upadhyay, H C Agarwal & Ravi Dhar

 

151

 

 

Acute and sub-acute effects of 2-butenoic acid-3-(diethoxy phosphinothioyl) methyl ester (RPR-II) on testis of albino rat

I A Khan, B V Reddy, M Mahboob, M F Rahman & Kaiser Jamil

 

162

 

 

Effects of short term treatment of solasodine on cauda epididymis in dogs

R S Gupta & V P Dixit

169

 

 

5-HT3 receptors in selective animal models of cognition

N Sridhar, A Veeranjaneyulu, D K Arulmozhi, C N V H B Gupta & R J Babu

174

 

 

Protective effect of N-acetylcysteine against gamma ray induced damages in rats –Biochemical evaluations

S Sridharan & C S Shyamaladevi

 

181

 

 

Inhibition of endocytotic functions in Dictyostelium discoideum treated with a

carbamate pesticide

Y Gurumurthy & S Chatterjee

 

187

 

 

Native state, energetic interaction of chlorophyll precursors and intraplastid location of S-adenosyl-L-methionine : Mg-protoporphyrin IX methyltransferase in etiolated leaves

Natalia Averina, Valentina Rassadina & Leonid Fradkin

 

 

192

Contd

Induction of metabolic shocks in source and sink of two cucurbits by molybdenum stress

Seema Kaushik & C M Govil

 

202

 

 

RAPD based DNA markers linked to anthracnose disease resistance in
Sorghum bicolor (L.) Moench.

S Panday, A Sindhu & K S Boora

 

206

 

 

In vitro propagation of Lagerstromia parviflora Roxb. from adult tree

S K Tiwari, M K Kashyap, M M Ujjaini & A P Agrawal

212

 

 

Impact of copper application on soil metabolism, energy budget and formation of stable aggregates by anecic earthworm in tea plantations

Aliva Patnaik

 

216

 

 

Notes

 

Potentiality of a new compound for in vitro differentiation between halophilic and non-halophilic vibrios

R Ray, A K Das, N K Dutta, A N Chakrabarty, B N Chaudhuri, S Seth

& Sujata G Dastidar

 

220

 

 

Assessment of performance of UV sterilizer for room air bacteria

P V Joshi

223

 

 


Reversibility of oxygen induced inactivation of nitrogenase in some enterobacteria

V Kannan & P N Raju

227

 

 

High frequency in vitro production of microrhizomes of Curcuma amada

Sanghamitra Nayak

230

 

 

Partial molecular characterization of some kiwi fruit cultivars by RAPD markers

Poonam Shirkot, D R Sharma, T Mohapatra & C K Shirkot

233

 

 

Report

 

Symposium on Challenges in Clinical Pharmacology

Dr M K Singhal

237

 

 

AUTHOR INDEX

 

Agarwal H C                               151

Agrawal A P                                    212

Arulmozhi D K                     174

Averina Natalia                           192

                                                   

Babu R J                                     174

Boora K S                                   206

                                      

Chakrabarty A N                        220

Chatterjee S                                 187

Chaudhuri B N                            220

Chopra Ashok K                         129

                                      

Das A K                                      220

Dastidar Sujata G                        220

Dhar Ravi                                    151

Dixit V P                                     169

Dutta N K                                   220

                                      

Fradkin Leonid                            192

                                      

Ghosh A K                                  144

Govil C M                                  202

Gupta C N V H B                       174

Gupta R S                                   169

Gurumurthy Y                            187

                                                   

Jamil Kaiser                                162

Joshi P V                                     223

                                                   

Kannan V                                    227

Kashyap M K                            212

Kaushik Seema                            202

Khan I A                                     162

                                                   

Mahboob M                                 162

Mohapatra T                              233

                                                   

Nayak Sanghamitra                     230

                                                   

Panday S                                     206

Pani P K                                      144

Patnaik Aliva                              216

Peterson Johnny W                     129

                                                   

Rahman M F                               162

Raju P N                                     227

Rassadina Valentina                    192

Ray R                                          220

Reddy B V                                  162

Ribardo Deborah A                     129

                                                   

Seth S                                          220

Sharma D R                                 233

Shirkot C K                                 233

Shirkot Poonam                          233

Shyamaladevi C S                       181

Sindhu A                                     206

Singhal M K                                237

Sivasubramanian P                      139

Sood Prem Prakash                      139

Sridhar N                                     174

Sridharan S                                  181

                                                   

Tiwari S K                                  212

                                                   

Ujjaini M M                               212

Upadhyay Ravi Kant                   151

                                                   

Veeranjaneyulu A                       174

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 129-138

 

 

Review Article

Phospholipase A2-activating protein ¾ An important regulatory molecule in modulating cyclooxygenase-2 and tumor necrosis factor production during
inflammation

Deborah A Ribardo, Johnny W Peterson & Ashok K Chopra

Inflammation is a complex multifactorial process and a hallmark of many inflammatory diseases. Most of the tissue destruction that occurs in these diseases is the result of an aberrant or often uncontrolled immune response. Factors that play an important role in such diseases include pro-inflammatory cytokines, complement, and eicosanoids. This review focuses on eicosanoids and their regulation via phospholipase A2-activating protein, which could be targeted as a new therapeutic tool to control inflammatory diseases.

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 139-143

 

 

Papers

Peripheral nerve connections influence the appearance of neurosecretary material in neural sheath of ventral ganglion of the fly Sarcophaga bullata:
An immunocytochemical study

P Sivasubramanian & Prem Prakash Sood

 

This study examined the role of the brain and peripheral connections with the target organs in the appearance of neurosecretary material within the dorsal neural sheath of the ventral ganglion of the fly S. bullata. Specifically, the accumulation of the neuropeptide FMRFamide (the neurosecretary material) was examined by immunocytochemistry. Immunoreactions were performed on: (1) a normal intact ventral ganglion, (2) an isolated ventral ganglion that was cultured in vivo, and (3) a ventral ganglion that was isolated by transection from the brain, but retained its peripheral nerve connections. The results demonstrate that (a) the neurons of the ganglia survive and exhibit FMRFamide immune reaction independent of their peripheral connections, and (b) the accumulation of neuropeptide in the dorsal neural sheath is controlled by intact peripheral nerve connections with the ganglion. It is suggested that in the absence of their peripheral connections, the axons of FMRFamide immunoreactive neurons fail to invade the neural sheath resulting in the accumulation of neurosecretary material.

 

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 144-150

 

 

Induced liver tumour further support to a genetic marker with its high correlation with chorioallantoic membrane phenotypes in selected layer lines*

A K Ghosh & P K Pani

The conventional chorioallantoic membrane (CAM) phenotype assay was conducted using 11-day-old embryonatic eggs of white Leghorn strains, each inoculated with 0.2 ml of subgroup A Rous sarcoma virus (RSV) and subgroup C RSV separately containing 103pfu ml-1. Eggs were further incubated for hatching. Harvesting of CAMs for counting of pocks and monitoring chicks for liver tumour (LT) mortality during 4 weeks of post-hatching period were followed. The conversely associated phenotype (CAP) incidence i.e. CAM(+) LT(-) and CAM(-) LT(+) was observed in all three lines for both subgroup A and C virus infection. The LT deaths of chicks in all strains occurred within 21 days post-hatch irrespective of virus subgroups. The regression analysis of %LT death (transformed data) distributed within pock count range (PCR) basis was performed. The regression coefficients (bi’s) were found to be non-significant, indicating that %LT death did not correlate with number of particles that entered the cells because the chicks that had at least 25 pock counts in CAMs died with few exceptions. This study upheld the view that the CAM phenotypes (S and R) under the control of a pair of alleles, as and ar at the tva locus and cs and cr at the tvc locus as reported extensively. Because of a high correlation coefficients between CAM and LT phenotypes [S and LT(+)] in respect of subgroup A (r = 0.72) and subgroup C (r = 0.81) infection, it is obvious that one could postulate a pleiotropic control of the two traits by the tva and tvc genes, respectively. Indeed fitting a 4-allele model in both tva and tvc locus, suggesting that CAPs are the indicator for nullifying the conventional 2-allele model proposed for the induced tumour expression phenotypes by leukosis sarcoma viruses.

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 151-161

 

 

Protein mediated cholesterol absorption in locusts

Schistocerca gregaria (Forskal) and Locusta migratoria (Linn)

Ravi Kant Upadhyay, H.C. Agarwal & Ravi Dhar

Absorption and transport of 3H cholesterol from the midgut to hemolymph and other tissues was studied in the locusts Schistocerca gregaria and Locusta migratoria. S. gregaria are able to absorb dietary cholesterol in the midgut and release into the hemolymph in vivo and into the incubation medium in virto. Certain proteins of midgut origin are involved in the absorption and release of cholesterol. The proteins designated as cholesterol binding proteins (CBP’s) were fractionated by gel filtration chromatography using Sepharose CL-6B-200 column. Presence of a protein and its binding with cholesterol is confirmed by TCA precipitation after subsequent incubation of midgut in the incubation medium. Cholesterol binding with the proteins was also confirmed in native polyacrylamide gel electrophoresis. Biosynthesis of this protein takes place in the midgut which is inhibited by a protein synthesis inhibitor, cycloheximide. It also inhibits absorption and release of cholesterol from the midgut. The cholesterol binding activity was associated with a peak containing proteins ranging from molecular weights of 17-32 kDa in SDS-PAGE gels. Treatment of midgut with cycloheximide resulted in reduced cholesterol binding activity. Dilipidation of mucin and transport in presence of bile salts yielded a higher cholesterol binding activity. Although the absorption and release of cholesterol was observed in the hemolymph of both sexes, the ovary exhibited higher cholesterol binding as compared to testis.

 

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 162-168

 

 

Acute and sub-acute effects of 2-butenoic acid-3-(diethoxy phosphinothioyl) methyl ester (RPR-II) on testis of albino rat*

I A Khan, B V Reddy, M Mahboob, M F Rahman & Kaiser Jamil

 

Acute and sub-acute toxic effects of a novel phosphorothionate coded as RPR-II on testis of albino rats were studied. In acute study rats received a single dose of 12.3 mg/kg of RPR-II and sacrificed after 24 hr. For sub-acute study 0.58 mg/kg/day was administered orally to rats for 10 and 21 days. Acute exposure of rats to RPR-II brought no change either in the gonadosomatic index (GSI) or in the structure of testis or in the serum levels of testosterone. Testis glutathione (GSH) level and glutathione S-transferase (GST) activity was significantly decreased whereas, acid phosphatase (AcP) levels increased significantly at 24 hr post-treatment. On 7th day (withdrawal period) after the cessation of the treatment the GSH, GST, AcP, and AkP levels reached to near control. The sub-acute study revealed a significant decrease in GSI on 10th and 21st day of the treatment. In contrast, a time-dependent and significant increased in GSH level and GST activity was observed on 10th and 21st day of post-treatment, except GSH level on 10th day, which was declined. Due to RPR-II treatment the testis AcP and alkaline phosphatase (AkP) levels were significant at both 10th and 21st day of medication but AcP levels were increased whereas AkP levels decreased. The histopathological studies on day 10th showed considerable loss of spermatozoids in testis and at 21st day complete derangement of cellular organization was observed. Testosterone levels decreased significantly on 10th day and remained significantly low at 21st day. However, withdrawal studies showed a recovery in testis of rat treated with RPR-II. GST, GSH, GSI, AcP and AkP values recovered, testosterone levels were also well recovered but recovery in testis structure remained at a low profile. The present study suggests that RPR-II may cause testicular toxicity in rats affecting the normal functioning of testis and it also gave some new information in withdrawal studies.

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 169-173

 

 

Effects of short term treatment of solasodine on cauda epididymis in dogs

R S Gupta & V P Dixit

Oral administration (80 mg/kg body wt./day for 30 days) of solasodine (extracted and isolated from the berries of the Solanum xanthocarpum) to intact dogs significantly decreased the epithelial cell height of cauda epididymides. The cells became atrophic and the lumen was devoid of spermatozoa. Castration followed by the adminstration of solasodine further reduced the epithelial cell height in comparison to castrated controls. Concurrent treatment of solasodine along with testosterone propionate was unable to restore the normal epithelial lumen parameters. Total protein, sialic acid, glycogen and acid phosphatase activities were significantly reduced in solasodine treated cauda epididymides. These result suggest antiandrogenic potency of solasodine.

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 174-180

 

 

5-HT3 receptors in selective animal models of cognition

N Sridhar, A Veeranjaneyulu, D K Arulmozhi, C N V H B Gupta & R J Babu

 

Role of 5-HT3 receptors in cholinergic hypofunctional models of cognitive impairment in the elevated plus maze model and a passive avoidance model is studied. Cognitive impairment was caused by scopolamine (1 mg/kg, ip) in mice and 5-HT3 ligands mCPBG (1 and 5 mg/kg, ip) and ondansetron (0.5 and 5mg/kg, ip) were administered before the pre-learning phase to study the effects on acquisition, while post-learning administration was used to determine the effects on consolidation. Ondansetron improved acquisition and retention in cholinergic hypofunctional models while mCPBG potentiated selected impaired cognitive indices. The results indicate the role of 5-HT3 receptors in cognition and that an ideal evaluation of 5-HT3 ligands in cognition should distinguish true cognitive effects from locomotor, motivational and emotional effects.

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 181-186

 

 

Protective effect of N-acetylcysteine against gamma ray
induced damages in rats  Biochemical evaluations

S Sridharan & C S Shyamaladevi

 

Received 20 July 2001; revised 11 October 2001

The effect of N-acetylcysteine (NAC) (1g/kg body weight in saline for 7 days) against the damages induced by gamma ray was studied. Whole body exposure of rats to g-rays (3.5 Gy) caused increases in lipid peroxides (P < 0.01). Reduced glutathione (GSH) (P < 0.01) and total sulphydryl groups (TSH) (P < 0.05), were found to be increased probably to counteract the damages produced by the lipid peroxides. The plasma antioxidant vitamins E, C and A were reduced. The activities of antioxidant enzymes, superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) were enhanced, which might be to eliminate the superoxide radical and H2O2 and accompanied by a fall in glutathione-s-transferase (GST) and glutathione reductase (GR) activity. The excessive production of free radicals and lipid peroxides might have caused the leakage of cytosolic enzymes such as aminotransferases (AST and ALT), lactate dehydrogenase (LDH), creatine kinase (CK) and phosphatases. Membrane damage is quite evident from histological studies undertaken in the intestinal tissue, which is susceptible to radiation damage. Intragastric pretreatment of NAC (1g/kg body weight in saline for 7 days) prevented the radiation induced damage to an appreciable extent. From the results it may be concluded that NAC is effective in protecting from the damages caused by g-ray radiations and its prospects as an adjuvant to radiotherapy should be considered.

 

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 187-191

 

 

Inhibition of endocytotic functions in Dictyostelium discoideum treated with a carbamate pesticide

Y Gurumurthy & S Chatterjee

Administration of a carbamate pesticide carbaryl (1-Naphthyl-N-methyl carbamate) at a concentration of 60 and 100 ppm greatly inhibits the endocytotic functions during growth of the cellular slime mold D. discoideum. The ingestion of fluorescien isothiocynate (FITC) labeled E.coli is reduced between 30 and 40% in the treated cells as compared to controls. Similarly, the uptake of FITC-labeled dextran, which has been used as fluid-phase marker for pinocytosis also show 40-50% inhibition in the treated cells. 3H-leucine uptake and incorporation are also inhibited in the treated cells. SDS-PAGE analysis of cytoskeletal proteins shows a higher actin association with the membrane of treated cells. The results demonstrate the detrimental effects of Carbamate on the soil microbe even at a very low concentration and the efficacy of the slime mold cells as a biosensor for the carbamate-induced cytotoxicity.

 

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp.

 

 

Native state, energetic interaction of chlorophyll precursors and intraplastid
location of S-adenosyl-L-methionine : Mg-protoporphyrin IX methyltransferase
in etiolated leaves

Natalia Averina, Valentina Rassadina & Leonid Fradkin

 

Low temperature fluorescence spectra (FS) and fluorescence excitation spectra (FES) of protoporphyrin IX (Proto), Mg-protoporphyrin IX and its monomethyl ester (MgProto-ME) and protochlorophyllide (Pchlide) in etiolated barley leaves treated with 5-aminolevulinic acid and/or 2,2'-dipyridyl were studied. The spectra of Proto and MgProto-ME showed a little dependence on temperature of registration and exhibited similarity to low temperature spectra in diluted organic and buffer solutions. However, a red wavelength shift for Soret bands of Proto and MgProto-ME was observed due to porphyrin interaction with bovine serum albumin in 0.05 M, Na2HPO4 solution at room temperature. Disaggregating treatments had no effect on Proto and MgProto-ME spectra in plants. These results suggested that in etiolated leaves Proto and MgProto-ME molecules were in a monomer state. The spectral properties of these molecules were determined by interaction of porphyrins with proteins and other plastid membrane components. The spectral analyses indicated an efficient energy migration from Proto and MgProto-ME molecules to active form of Pchlide which emitted at 656nm, and no energy transfer from carotenoids to porphyrins in vivo. These findings suggested that Proto and MgProto-ME from carotenoids, and close location of these porphyrins and photoactive Pchlide in etioplast membranes. The latter conclusion was strongly supported by an observation that in etiolated leaves, S-adenosyl-L-methionin:Mg-protoporphyrin IX methyltransferase, which converts MgProto into MgProtoME, were located not only in prothylakoids but also in prolamellar bodies containing photoactive Pchlide.

 

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 202-205

 

 

Induction of metabolic shocks in source and sink of two cucurbits
by molybdenum stress

Seema Kaushik & C M Govil

Different concentrations of ammonium molybdate (10-7 to 10-4M) affected the levels of metabolites in the source and sink organs of the seedlings of C. melo and C. vulgaris and data were recorded at 7, 14 and 21 days after treatment (DAT) of molybdenum (Mo). Reducing and non reducing sugars declined with an increase in concentration of ammonium molybdate from 10-7 to 10-4M. Soluble protein and dry weight of seedlings increased in source at lower concentration (10-7 M) and gradually decreased in all other concentrations (10-6, 10-5 and 10-4 M). Starch was slightly accumulated in hypocotyl and fresh weight constantly declined with an increase in ammonium molybdate concentration from 10-7 to 10-4 M in all the parts of seedlings viz. cotyledon, hypocotyl and roots. Thus molybdenum at higher concentration induced decline in the metabolite levels in source and sink as well as in transporting organs.

 

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 206-211

 

 

RAPD based DNA markers linked to anthracnose disease resistance in
Sorghum bicolor ( L.) Moench
.

S Panday, A Sindhu & KS Boora

Anthracnose caused by Colletotrichum graminicola is one of the major diseases of sorghum. The locus for disease resistance in sorghum [Sorghum biocolor (L.) Moench] accession G73 was found to segregate as a simple recessive trait in a cross to susceptible cultivar HC136. In order to identify molecular markers linked to the locus for disease resistance, random amplified polymorphic DNA (RAPD) analysis was coupled with bulk segregant analysis. DNA from the parental cultivars and the bulks were screened by PCR amplification with 114 RAPD primers. Three RAPD primers amplified a sequence that consegregated with the recessive resistance allele, while another three amplified a band linked to the susceptible allele. The six disease linked markers were screened with individual resistant and susceptible genotypes to observe degree of linkage of identified RAPD markers with the gene for resistance. Two primer sequences (OPI 16 and OPD 12) were found to be closely linked to the locus for disease resistance.

 

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 212-215

 

 

In vitro propagation of Lagerstromia parviflora Roxb. from adult tree

S K Tiwari, M K Kashyap, M M Ujjaini & A P Agrawal

 

A micropropagation protocol based on axillary bud proliferation has been developed from mature Lagerstromia parviflora adult tree. Nodal segments cultured on woody plant medium supplemented with 5.0 µl. BAP and 0.25µm IAA gave maximum (86.9%) morphogenetic response. Proliferated shoots (10.7 per explants) were elongated to 3.9 cm within 6 weeks. In vitro produced micro-shoots were subjected to an IBA treatment (500 ppm for 2 min. dip) and placed under misting conditions for rooting. Misting beds were prepared with sand: soil (3:1) for 80.6% rooting and was acclimatized. Shoot length seems to be important to induce adventitious roots. The highest (91.7%) rooting was recorded on shoots ranging a length between 3.1-4.0 cm. Rooted and hardened plants were later transferred to poly bags and maintained in shadenet house. The protocol has the realizes capacity to produce 260 plants from a single explants within 10 months multiplication cycle.

 

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 216-219

 

 

Impact of copper application on soil metabolism, energy budget and formation of stable aggregates by anecic earthworm in tea plantations

Aliva Patnaik

 

The preparation of daily energy budget of earth worm Lampito mauritii showed (i) decrease in consumption by about 66%, (ii) decrease of egestion 97%, (iii) decrease in growth by 80%, and (iv) enhancement in maintenance cost by about 31.5% on exposure to 8 ppm copper in comparison to zero level exposure. The stable aggregate formations also decreased by 67.6% at 8 ppm copper as compared to zero level exposure. Two way ANOVA showed significant decrease in stable aggregate formation and biomass at 5% level of significance on exposure to 8 ppm copper. The soil metabolism also increased under the negative impact of copper.

 

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 220-222

 

 

Notes

Potentiality of a new compound for in vitro differentiation between
halophilic and non-halophilic vibrios

R Ray, A K Das, N K Dutta, A N Chakrabarty, B N Chaudhuri, S Seth & Sujata G Dastidar

Sensitivity of 21 halophilic vibrios and 16 clinical isolates of non-halophilic vibrios was determined against a new possible antivibrio agent, a pyrimidine analogue, 4, 6-dimethylpyrimidine -2-thiol (4,6-DMPT). It appeared to be a vibriocidal agent, having a mean MIC and MBC of 32 mg/ml for halophilic strains and 64 mg/ml for non-halophilic strains and an LD50 of 300 mg/Kg body weight of mice. Thus, 4,6-DMPT may help an in vitro distinction between halophilic and non-halophilic vibrios. Sensitivity of these strains was also studied with respect to pteridine, crystal violet and Tween 80 hydrolysis as further markers distinguishing between these 2 groups which could also be differentiated by their growth on TCBS or/and CLED media.

 

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 223-226

 

 

Assessment of performance of UV sterilizer for room air bacteria

P V Joshi

Paper presents a technique for performance of UV sterilizer for room air bacteria. Patterns of decay of room air bacteria concentration during sterilization and build-up there after as a function of time is studied. Decay process seems to follow exponential pattern. Half-lives during decay are estimated. For single sterilizer unit with a dose of 16 W the decay half-life is around 8.6 min. For the dose of 32 W (2 sterilizers), half-life is estimated to be 6.18 min. The removal rates of room air bacteria due to sterilizer are compared with the natural decay of aerosols at steady state. The importance of decay half-life in the assessment has been stated. The bacteria concentration buildup process after putting off the sterilizers seems to be sigmoidal in nature. The buildup half-life is estimated to be around 53 min for present experimental conditions.

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 227-229

 

 


Reversibility of oxygen induced inactivation of nitrogenase in some enterobacteria

V Kannan & P N Raju

Aerobic and microaerobic diazotrophs possess numerous oxygen restriction strategies to protect nitrogenase from inactivation by oxygen without interfering with energy generation through oxidative phosphorylation. Protection by conformational change in nitrogenase was first detected and described in Azotobacter. This strategy once considerd unique for Azotobacter has been shown in this study to occur in Citrobacter freundii (Braak) Werkman and Gillen and Klebsiella pneumoniae subspecies rhinoscleromatis (Trevisan) Migula also. However, in these enteric bacteria the entire enzyme is not protected probably due to the absence of any respiratory protection similar to that found in the aerobe, Azotobacter.

 

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 230-232

 

 

High frequency in vitro production of microrhizomes of Curcuma amada

Sanghamitra Nayak

Microrhizomes were induced at the base of the in vitro derived shoots of Curcuma amada grown in the liquid MS medium supplemented with BA (5 mg/l), sucrose (80 g/l) and incubated under 16 hr photoperiod. They were produced year round in culture, harvested after 90 days of growth in medium, and could be used as seeds and germinated to plantlets showing normal growth.

 

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 233-236

 

 

Partial molecular characterization of some kiwi fruit cultivars by RAPD markers

Poonam Shirkot, D R Sharma, T. Mohapatra & C K Shirkot

Molecular variability among seven cultivars of A. deliciosa var. deliciosa was investigated through RAPD markers. Thirty four decamer primers were screened generating polymorphic patterns of amplified DNA for these cultivars. Twenty one selected primers gave clear and reporducible patterns. A total of 430 bands were produced and 29.37% of them were polymorphic. The patterns distinguished between the cultivars and their analysis established an approach to classification within A.deliciosa var. deliciosa based on RAPD markers. The dendrogram clearly differentiated male from female cultivars. While abbot and allison female cultivars were closely related, bruno and abbot female cultivars showed maximum dissimilarity.

 

Indian Journal of Experimental Biology

Vol. 40, February 2002, pp. 237-238

 

 

Report

Symposium on ‘Challenges in Clinical Pharmacology’