Correlation of aberrant expression of p53, Rad50, and cyclin-E proteins with microsatellite instability in gallbladder adenocarcinomas

Gallbladder carcinoma is an uncommon, but highly malignant tumor, with poor prognostic, and diagnostic manifestations in early stages. The Indian Council of Medical Research reported increased incidence of gallbladder carcinoma in the surviving population of the Bhopal gas tragedy that involved exposure of more than 500,000 people to methyl isocyanate gas. The severity of exposure, and increased multi-systemic morbidity in the survivors stimulated us to examine the molecular changes leading to gallbladder carcinoma. Surgically resected samples (N = 40) of gallbladder carcinoma were studied for the p53, Rad50, and cyclin-E expression by immunohistofluorescence bioimaging. Among the 40 samples, 23, 11, and 10 showed p53, Rad50, and cyclin-E expression, respectively, in moderately differentiated adenocarcinomas, demonstrating the prevalence and invasiveness of this disease in the methyl isocyanate-exposed population (P = 0.0009). Nevertheless, co-expression of Rad50, and cyclin-E with p53 was absent in adenomas with dysplasia, demonstrating their independent roles. We conclude that there was altered expression of p53, Rad50, and cyclin-E in the malignant transformation of gallbladder carcinoma in this methyl isocyanate gas-exposed cohort. Hence, these proteins may be useful as markers to identify premalignant lesions that are likely to progress into malignant adenocarcinoma.

Siva is an apoptosis-selective p53 target gene important for neuronal cell death

p53 plays a central role in neuronal cell death resulting from acute injury or disease. To define the pathway by which p53 triggers apoptosis, we used microarray analysis to identify p53 target genes specifically upregulated during apoptosis but not cell cycle arrest. This analysis identified a small subset of targets highly selective for the p53 apoptotic response, including Siva, a proapoptotic protein whose function is not well understood. Siva's expression pattern suggests that it plays an instructive role in apoptosis, and accordingly, we demonstrate that Siva is essential for p53-dependent apoptosis in cerebellar granule neurons. In addition, we determine that endogenous Siva is associated with the plasma membrane and that Caspase-8 and Bid are important for neuronal apoptosis. Our studies highlight the participation of membrane signaling events in p53's apoptotic program in primary neurons and have significant implications for understanding the mechanisms underlying pathogenesis after neuronal injury and in neurodegenerative diseases.

Fine needle aspiration cytology in reactional and non-reactional leprosy

BACKGROUND

Histopathological evaluation of skin lesions is not feasible in many leprosy endemic areas. Fine needle aspiration cytology (FNAC) is a simpler tool compared to histopathology for the evaluation of the cytomorphology of skin lesions.

AIMS

To study the cytomorphology of leprosy lesions in fine needle aspirates and correlate it with the histopathology.

METHODS

Seventy leprosy patients diagnosed and classified according to Ridley Jopling scale were included. Fine needle aspirates were taken from the lesion followed by a skin biopsy from the same site for histopathological examination after H/E staining.

RESULTS

Borderline leprosy patients with Type I reaction showed significantly large numbers of giant cells, collagen and elastin in their smears as compared to those without reaction. The smears were more heavily cellular with fragmented collagen and elastin along with significant increase in neutrophils in patients with Type II reaction while foamy macrophages with fatty background were common in non-reactional lepromatous leprosy patients. A complete correlation between histopathological and cytomorphological findings was observed in 77.3% of cases.

CONCLUSION

FNAC may be used as an alternative tool to assess leprosy lesions in areas where histopathological services are not readily available.

Efficacy trial on the purified compounds of the seeds of Carica papaya for male contraception in albino rat

The contraceptive efficacy and toxicological screening of the two principal compounds, MCP I and ECP I, isolated from the seeds of Carica papaya, in male albino rats at the standardized dose regimen, at 50 mg/kg b.w./day, for a period of 360 days and up to 90 days of treatment withdrawal have been reported. The body and organ weights, cauda epididymal sperm characteristics, androgen sensitive tissue biochemistry, reactive oxygen species and anti-oxidant defense system in the cauda epididymal microenvironment, histology and ultrastructure of testis and cauda epididymis, histology of seminal vesicle and prostate, toxicological investigations through routine hematology and serum clinical chemistry, sexual behaviour and fertility index have been studied. The results revealed that oral administration of MCP I and ECP I were equally effective, exhibiting complete inhibition of sperm motility following 90 days of treatment that coincided with a gradual and significant decline in cauda epididymal sperm density, percent viable spermatozoa and significant increase in sperm anomalies. Histology of testis of treated animals revealed degenerated germinal epithelium, vacuolization in Sertoli cells and proliferating germ cells and disturbances in spermatid differentiation. Spermatogonial stem cell reserves and Leydig cells appeared normal. Ultrastructure of the testis revealed vacuolization in the Sertoli cells and germ cells, loss of cytoplasmic characteristics in the Sertoli cells, nuclear degeneration and mitochondrial vacuolization in spermatocytes and spermatids. Leydig cells exhibited steroidogenic features. Cauda epididymis showed normal epithelial cell function. Absence of spermatozoa or disruption of spermatozoa clusters in the lumen were evident. Ultrastructure of cauda epididymis revealed normal secretory activity. Morphology of seminal vesicle and prostate of the treated animals were comparable to control animals. Serum testosterone, tissue biochemical and toxicological parameters remained unaffected. Fertility test revealed 100% efficacy. All the altered parameters showed sign of recovery following 90 days of treatment withdrawal. It is concluded that both MCP I and ECP I are equally effective in terms of contraceptive efficacy which is likely reversible and without adverse side effects.

Mycobacterium tuberculosis isolate with a distinct genomic identity overexpresses a tap-like efflux pump

BACKGROUND

One mechanism proposed for drug resistance in Mycobacterium tuberculosis (MTB) is by efflux of the drugs by membrane located pumps. We report a novel and definite association between drug resistance and transcription levels of a tap-like pump (Rv1258c) in a multi-drug resistant MTB patient isolate (ICC154) which possesses a unique genotypic signature.

MATERIALS AND METHODS

The isolate ICC154 was tested for drug sensitivity. Over-expression of Rv1258c as a function of drug pressure was analyzed by RT-PCR and the strain was typed using fluorescent amplified fragment length polymorhism (FAFLP).

RESULT

In the presence of rifampicin and ofloxacin, this isolate shows increased transcription of the gene Rv1258c. Genotypic fingerprinting revealed the presence of unique FAFLP markers.

CONCLUSION

A clear association between drug resistance and overexpression of an efflux protein is evident from our studies. The presence of specific markers has implications in rapid identification of MDR clinical isolates and consequent disease management.

Ultrastructural changes in the testis and epididymis of rats following treatment with the benzene chromatographic fraction of the chloroform extract of the seeds ofCarica papaya

The benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya at a dose of 10 mg/rat/day for 150 days, which has shown a total inhibition of motility, reduced sperm count and infertility, was tested to de fi ne the mode of action at the subcellular level in the testis and epididymis. The ultrastructure of the testis of the treated animals revealed no appreciable changes in the subcellular characteristics. The mechanism of protein synthesis as well as steroidogenesis were evident in the Sertoli cells while the spermatogonia, spermatocytes and spermatids, both round and elongated, depicted a prominent nucleus, distinct nuclear membrane and cytoplasmic characteristics indicating normal germ cell differentiation. The principal cells of the cauda epididymis were characterized by the presence of well-de fi ned rough endoplasmic reticulum, mitochondria, Golgi bodies and secretary granules, suggesting active secretory functions. The absorptive function of the cauda epididymis was evidenced by the presence of numerous vesicles and multivesicular bodies adjacent to stereocilia. It is concluded that the inhibition of sperm motility by the drug could be due to other epididymal factors rather than the subcellular characteristics of testis and epididymis.

Chloroform extract of Carica papaya seeds induces long-term reversible azoospermia in langur monkey

AIM

To evaluate the antifertility activity of the chloroform extract of Carica papaya seeds by oral administration in langur monkey, Presbytis entellus entellus.

METHODS

The chloroform extract of Carica papaya seeds, 50 mg/kg/day, was administered orally for 360 days to adult male langur monkeys. The sperm characteristics by light and electron microscopy, the sperm functional tests, the semen biochemistry, the serum testosterone level, the Leydig cell function, and the histology and ultrastructure of testis were determined to evaluate the antifertility activity and the blood biochemistry and hematology, to evaluate the toxicology.

RESULTS

The extract gradually decreased the sperm concentration since days 30-60 of treatment with a total inhibition of sperm motility, a decrease in sperm viability and increase in sperm abnormality. Azoospermia was observed after day 90 of treatment and continued during the whole treatment period. Treatment withdrawal resulted in a gradual recovery in these parameters and 150 days later they reverted to nearly the pretreatment values. Morphological observation of the ejaculated sperm by light and scanning electron microscopy showed deleterious changes, particularly on the mid-piece. Sperm functional tests, viz., sperm mitochondrial activity index, acrosome intactness test and hypo-osmotic swelling test scored in the infertile range during treatment and returned to the fertile values 150 days after drug withdrawal. Histology of the testis revealed shrunken tubules, germ cell atrophy and normal Leydig cells. Ultrastructure of the testis showed vacuolization in the cytoplasm of Sertoli cells and germ cells. Loss of cytoplasmic organelles were evident in the spermatocytes and spermatids. Round spermatids showed loss of Golgi bodies, peripheral mitochondria and vacuolated cytoplasm, indicating maturational arrest. Leydig cell functional test indicated a mild inhibition of steroidogenic function. Haematology and serum biochemistry study disclosed no significant toxicological effect and the serum testosterone level was not affected.

CONCLUSION

Carica papaya seed extract may selectively act on the developing germ cells, possibly mediated via Sertoli cells, leading to azoospermia.

Vas deferens, a site of male contraception: an overview

The vas deferens is a site which can be exploited for male contraception without undue side effects. The only effective technique available for male contraception is vasectomy, being practiced world wide, despite that it is a permanent surgical procedure and its successful reversal is not assured. Although no-scalpel vasectomy minimizes surgical procedures, the fate of its reversal is akin to that of vasectomy. Several occlusive and non-occlusive vasal procedures which claim to be reversible without surgical intervention, possess more disadvantages than advantages. Vas occlusion with plug, 'Shug' or medical grade silicone rubber, although claimed to produce reversible azoospermia without affecting spermatogenesis, requires skilled microsurgery for their implantation and later removal. RISUG, a non-sclerotic polymer styrene maleic anhydride (SMA), could be more advantageous than vasectomy and other vas occlusive procedures in that it could be a totally non-invasive procedure by "no-scalpel injection" and "non-invasive reversal". It is claimed to offer long-term contraception without adverse side effects and also to be possible as a male spacing method by repeated vas occlusion and non-invasive reversal. The drug is currently under multicentre Phase III clinical trial.

Metastatic placental site trophoblastic tumor: a case report

Placental site trophoblastic tumor (PSTT) is very rare. It is an unusual variant of gestational trophoblastic neoplasia usually confined to the uterus, although 10% of patients have metastases. The clinical behaviour of PSTT varies and despite knowledge of its histology, diagnosis of this rare form of trophoblastic disease and prediction of its biological behaviour remains difficult due to only a few cases reported in literature.

Reversible azoospermia by oral administration of the benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya in rabbits

Contraceptive efficacy, reversibility and toxicity, if any, of the benzene, chloroform and ethyl acetate chromatographic fractions of the chloroform extract of the seeds of Carica papaya have been investigated in adult male rabbits at a dose regimen of 50 mg/animal/day for 150 days of treatment. Body weight, semen analysis, hematology, serum clinical biochemistry and the fertility status of control and treated animals were evaluated. Chloroform and ethyl acetate chromatographic fractions did not produce appreciable changes in these parameters. However, the benzene chromatographic fraction resulted in uniform azoospermia after 15 days of treatment, which was maintained for the remainder of the 150-day observation period. The levels of fructose, glycerophosphocholine, acid phosphatase and lactate dehydrogenase in the seminal plasma were within the control range. Hematology and the serum clinical parameters showed no appreciable changes, indicating lack of toxicity. The libido of the treated animals was normal and the fertility rate was zero. Complete normalcy of altered parameters was observed 60 days following withdrawal of treatment. It is concluded that the benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya possesses reversible male contraceptive potential and the effects appear to be mediated through the testis.

Ideal ward round making in neurosurgical practice

The success of a perfect ward round lies in the role of the consultant leading the 'round making group' (RMG) as well as the hallmark of effective questioning and participation of each member. Twelve senior consultants with more than 10 years' experience in neurosurgical practice at three different university hospitals were observed during round making by a participant observer. Observations were made on the group climate of the RMG, the leadership pattern and language expressed by the clinician conducting the round and the effectiveness in his performance as a leader during clinical discussions. The group climate showed evidence of good productivity and flexibility with 92% and 75% consultants, pleasantness of climate was above average with only 50% (6/12) and poor objectivity with 42% (5/12) consultants. Forty two percent of the consultants were not always very well comprehensible, while only 50% (6/12) spoke exactly fitting the occasion. Only 33% (4/12) of the consultants used humour effectively, while 42% (5/12) spoke unnecessarily in between discussion and were poor in introducing the problems of patient to the round making group. Ward round making in neurosurgical practice needs a holistic approach with motivation, planning, leadership skills and structured curriculum to fulfill its objectives.

Solution structure of the catalytic domain of human collagenase-3 (MMP-13) complexed to a potent non-peptidic sulfonamide inhibitor: binding comparison with stromelysin-1 and collagenase-1

The full three-dimensional structure of the catalytic domain of human collagenase-3 (MMP-13) complexed to a potent, sulfonamide hydroxamic acid inhibitor (CGS 27023) has been determined by NMR spectroscopy. The results reveal a core domain for the protein consisting of three alpha-helices and five beta-sheet strands with an overall tertiary fold similar to the catalytic domains of other matrix metalloproteinase family members. The S1' pocket, which is the major site of hydrophobic binding interaction, was found to be a wide cleft spanning the length of the protein and presenting facile opportunity for inhibitor extension deep into the pocket. Comparison with the reported X-ray structure of collagenase-3 showed evidence of flexibility for the loop region flanking the S1' pocket in both NMR and X-ray data. This flexibility was corroborated by NMR dynamics studies. Inhibitor binding placed the methoxy phenyl ring in the S1' pocket with the remainder of the molecule primarily solvent-exposed. The binding mode for this inhibitor was found to be similar with respect to stromelysin-1 and collagenase-1; however, subtle comparative differences in the interactions between inhibitor and enzyme were observed for the three MMPs that were consistent with their respective binding potencies.

Sterility due to inhibition of sperm motility by oral administration of benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya in rats

The contraceptive effects of benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya have been reported in male albino rats at the dose regimens 5 and 10 mg/animal/day; oral for 150 days. The body weight, weight of testis, epididymis, seminal vesicle and ventral prostate remained unaltered during the entire course of the investigation. Total suppression of cauda epididymal sperm motility coincided with a decrease in sperm count, viability and an increase in per cent abnormal spermatozoa during 60-150 days observation period. Minor changes in the germ cell proliferations in the testis and vacuolization and pyknotic nuclei in the few epithelial cells of the cauda epididymis were observed. Histology and biochemical composition of testis and accessory sex organs, haematology and serum clinical biochemistry and serum testosterone levels remained unchanged throughout the course of the investigation. Test for estrogenicity indicated mild estrogenicity. Monthly fertility test showed negative fertility. All the altered parameters returned to normal level following 60 days withdrawal of the treatment. The results suggest that the benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya exerts antifertility effects in rats without adverse toxicity and that the effects may be directly rendered on the spermatozoa.

Human sperm immobilization effect of Carica papaya seed extracts: an in vitro study

AIM

To examine if the seed extracts of Carica papaya, which showed antispermatogenic/sperm immobilization properties in animal models, could cause human sperm immobilization in vitro.

METHODS

Chloroform extract, benzene chromatographic fraction of the chloroform extract, its methanol and ethyl acetate sub-fractions and the isolated compounds from the sub-fractions i.e., ECP 1 & 2 and MCP 1 &2, of the seeds of Carica papaya were used at concentrations of 0.1%, 0.5%, 1% and 2%. Sperm motility was assessed immediately after addition of extracts and every 5 minutes thereafter for 30 minutes.

RESULTS

There were dose-dependent spermicidal effects showing an instant fall in the sperm motility to less than 20% at 2% concentration. Isolated compounds ECP 1 & 2 were more effective inducing a motility of less than 10%. Many of the spermatozoa became vibratory on the spot. Total inhibition of motility was observed within 20-25 min at all concentrations of all products. Scanning and transmission electron microscopy revealed deleterious changes in the plasma membrane of the head and mid-piece of spermatozoa. Sperm viability test and the number of abnormal spermatozoa after completion of incubation suggested that the spermatozoa were infertile. The effects were spermicidal but not spermiostatic as revealed by the sperm revival test.

CONCLUSION

The results reveal spermicidal activity in vitro of the seed extracts of Carica papaya.

Purification and characterization of polygalacturonase from banana fruit

Polygalacturonase isoenzyme 3 (PG-3) was purified to homogeneity with a specific activity of 0.7 mu katal mg-1 protein from banana fruit pulp. The purified enzyme was a glycoprotein with ca. 8% carbohydrate. The molecular weight of the native enzyme was found to be 90 +/- 10 kDa with a subunit molecular weight of 29 +/- 2 kDa. The enzyme exhibited optimum activity at pH 4.3 and temperature 40 degrees C with activation energy 35.4 kJ mol-1. A unique property of the enzyme was the requirement of -SH groups for the enzyme activity. The enzyme was inhibited by p-CMB and activated by 2-ME and DTT. The inhibition of p-CMB could be reversed by DTT. The enzyme contained eight free -SH groups. The Km of the enzyme was 0.15% for polygalacturonic acid.

Contraceptive evaluation and toxicological study of aqueous extract of the seeds of Carica papaya in male rabbits

The contraceptive evaluation and toxicological effects of the aqueous extract of the seeds of Carica papaya in adult male rabbits have been reported. Thirty adult male rabbits were divided into five groups of six animals each; Group I, control; Groups II-V were administered orally with aqueous extract of the seeds of C. papaya at doses of 20, 50, 75 and 100 mg/kg per day for 150 days, respectively. The body weight, reproductive organs weight, semen analysis, semen biochemistry, toxicological profiles and the fertility status have been recorded. The aqueous extract failed to exhibit contraceptive effects at any of the dose regimens tested, contrary to the observations made in the previous studies. Unaltered toxicological profiles indicated that the drug was free of side effects. The results suggest that the failure of contraceptive effects may be due to species specificity, relative resistance of the animals to the drug or lack of potency of the extract due to factors generally affect biological activity of the plant preparations.

Estimation of oxidative products of nitric oxide (nitrates, nitrites) in preeclampsia

Oxidative products of nitric oxide, serum nitrates and nitrites were estimated in 50 primigravidas with preeclampsia and in 50 gestation and age-matched normotensive primigravidas. Thirty three (66%) of these women had mild preeclampsia and 17 (34%) had severe preeclampsia. Serum nitrate and nitrite levels were significantly higher in preeclamptic women (nitrates - 15 +/- 1.17; nitrites - 11.82 +/- 1.16 micromol/L) than in the normotensive pregnant women (nitrates 11.82 +/- 1.16; nitrites - 5.08 +/- 0.47 micromol/L, p < 0.001). In preeclamptic women, serum nitrate and nitrite levels correlated with the severity of the disease (mild preeclampsia nitrate - 14.46 +/- 1.98; nitrite 6.21 +/- 0.84 micromol/L, severe preeclampsia nitrate - 16.65 +/- 3.64; Nitrite - 6.87 +/- 1.56 micromol/L). In preeclampsia there was significant positive correlation between nitrate and nitrite levels and diastolic blood pressure and proteinuria.

The baculovirus antiapoptotic p35 gene also functions via an oxidant-dependent pathway

Cellular imbalance in the levels of antioxidants and reactive oxygen species resulting in apoptosis is directly associated with a number of parasitic infections, aging, and several genetic and multifactorial diseases. The baculovirus AcNPV-encoded antiapoptotic p35 gene prevents apoptosis induced by a variety of apoptotic agents in different systems. We demonstrate the ability of the p35 gene to inhibit oxidative stress-induced apoptosis. In vitro cultured Spodoptera frugiperda (Sf9) insect cells infected with wild-type AcNPV carrying the antiapoptotic p35 gene did not undergo apoptosis when subjected to oxidative stress generated by the exogenous application of oxidants or in vivo generation of reactive oxygen species or on direct exposure of cells to UV radiations. An AcNPV mutant carrying a deletion of the p35 gene failed to arrest cell death. Transfection of cells with a recombinant plasmid containing the p35 gene under the transcriptional control of a stress promoter (Drosophila hsp70) was also able to rescue cells from oxidative stress-induced cell death, demonstrating the direct involvement of P35. ESR spin-trapping studies conducted in vitro and in vivo demonstrated that P35 functions directly as an antioxidant by mopping out free radicals and consequently prevents cell death by acting at an upstream step in the reactive oxygen species-mediated cell death pathway.

Reversible contraception with chloroform extract of Carica papaya Linn. seeds in male rabbits

The contraceptive efficacy and reversibility of the chloroform extract of the seeds of Carica papaya in adult male rabbits were investigated. Eighteen adult male rabbits were divided into three groups of six animals each; Group I--control, Group II--administered chloroform extract of the seeds of Carica papaya at 20 mg/animal/d for 150 d by gavage, and Group III--administered the seed extract at 50 mg/animal/d for 150 d. Body weight and organ weight, semen analysis, sperm morphology by scanning electron microscopy, semen biochemistry, histology of the testis, haematology, serum clinical biochemistry, and the fertility status of the control and the treated animals were evaluated. Body weight and the weight of the testis, epididymis, seminal vesicles, and prostate did not show appreciable changes. Sperm concentration showed a gradual decline, reached severe oligospermia (fewer than 20 million/mL) after 75 d treatment, and attained uniform azoospermia after 120 d treatment. Sperm motility and viability were severely affected after 45 d treatment and reached less than 1% after 75 d treatment. The morphology of the spermatozoa by scanning electron microscopy revealed membrane damage in the acrosome, bent midpiece, coiled tail, and detached head and tail. The levels of fructose, glycerylphosphorylcholine, acid phosphatase, and lactate dehydrogenase in the seminal plasma were unaltered. Histology of the testis revealed arrest of spermatogenesis beyond the level of spermatocytes. No toxicity was evident from the haematology and serum biochemistry parameters. The libido of the treated animals was unaffected and the fertility rate was zero. The effects were comparable in both the dose regimens (Groups II and III) and were restored to normal 45 d after withdrawal of the treatment.

The expression, refolding, and purification of the catalytic domain of human collagenase-3 (MMP-13)

We have cloned, expressed, and purified a recombinant C-terminal truncated form (residues Glu103-Asn274) of human collagenase-3 (MMP-13) in Escherichia coli. The molecule contains the catalytic domain of the enzyme and is expressed almost exclusively as inclusion bodies. Using a combination of rapid dilution and diafiltration, the enzyme has been successfully refolded from these inclusion bodies. The protein was purified to homogeneity using cation-exchange and size-exclusion chromatography. The purified enzyme is a monomer with a Mr of approximately 19,600 and was characterized using a variety of techniques including, SDS-PAGE, RP-HPLC, LC-MS, amino acid analysis, and dynamic light scattering. Microheterogeneity at the NH2-terminus of the refolded, purified protein disappeared after incubating for 30-60 min at 37 degreesC. The enzyme was highly active using a fluorescent peptide substrate and was found to release S-GAG from bovine nasal cartilage chips.

Intravasal contraception with styrene maleic anhydride and its noninvasive reversal in langur monkeys (Presbytis entellus entellus)

In male langurs with azoospermia induced by vas occlusion with styrene maleic anhydride (SMA), the exploratory feasibility of azoospermia reversal by a new noninvasive reversal procedure has been assessed. Palpation, percutaneous electrical stimulation of the vas deferens, forced vibratory movement, suprapubic percussion, and per rectal digital massage of the vas deferens are the components of the multimodal noninvasive reversal procedure. The exploratory investigation reveals that a single application of the procedure leads to reversal of azoospermia. Normospermia with normal motility and viability appears after third ejaculation onwards after reversal manipulations. Ultrastructure of the spermatozoa, using scanning and transmission electron microscopy, revealed that the spermatozoa attained normalcy and sperm functional tests (i.e., hypo-osmotic swelling test, slide test for acrosome intactness, and test for sperm mitochondrial activity index) further confirmed the normalcy of the spermatozoa toward their fertilizing ability. Semen biochemistry appeared normal throughout the course of investigation. The morphology of the vas deferens, which showed exfoliation of the epithelium, was in the process of regaining normalcy after 90 days of reversal manipulations. The results suggest that noninvasive reversal technique offers the possibility of the functional azoospermia reversal within a short period of time.

Multiple forms of polygalacturonase from banana fruits

Three multiple forms of polygalacturonase (PG) in ripe and two in unripe banana (Musa acuminata) fruits were separated by DEAE-cellulose and further purified using Sephadex G-150 chromatography. The multiple forms can be differentiated from each other on the basis of their properties. PG1 and PG3 were identified as endo-PG and PG2 as exo-PG on the basis of decrease in viscosity, increase in reducing sugar and the reaction product. PG2 and PG3 increased with the ripening of fruits. PG1, PG2 and PG3 exhibited optimum activity at pH 3.3, 3.7 and 4.3, respectively. Complete loss of PG2 and PG1 activities occurred at 60 and 70 degrees, but PG3 retained 60 and 50% activity respectively. The three forms showed a different response towards divalent metal ions. Ca2+ activated PG1 activity only. Teepol 0.1%, inhibited PG1 activity by 25%, but PG2 and PG3 activities were completely inhibited. CTAB, 0.1%, had no effect on PG1 and PG2 activities, but inhibited PG3 activity by 40%. 2-ME stimulated PG2 and PG3 activities but had no effect on PG1 activity. Gel filtration through Sephacryl indicated M(r) of 23,200, 58,000 and 130,000, respectively, for PG1, PG2 and PG3. The substrate saturation curve for PG1 and PG2 were Michaelian, while PG3 showed biphasic curve. The Km values of PG1 and PG2 were 0.22% and 0.14%, respectively.

FliN is a major structural protein of the C-ring in the Salmonella typhimurium flagellar basal body

The Salmonella typhimurium FliN protein has been proposed to form a mutually interacting complex with FliG and FliM, the switch complex, that is required for flagellar morphogenesis and function. We have used affinity chromatography for purification of extended flagellar basal bodies sufficient for quantitative analysis of their protein composition. The belled, extended structure is predominantly comprised of the switch complex proteins; with FliN present in the most copies (111 +/- 13). This explains why single, missense fliN, fliG or fliM mutations, found in many non-motile strains, can alter the belled morphology. Cell lysates from these strains contained the wild-type complement of FliG, FliM and FliN; but the basal bodies lacked the outer, cytoplasmic(C)-ring of the bell and were separated by sedimentation from FliM and FliN. The amount of FliG present in basal bodies from wild-type and one such mutant, FliN100LP, was comparable. These data show that: (1) the mutations define a FliG and FliMFliN multiple contact interface important for motility. (2) FliG is responsible for the increased size of the membrane-embedded MS-ring complex of belled relative to acid-treated basal bodies. (3) FliN, together with FliM, account for most of the C-ring. As a major component of the C-ring, FliN is distinct from the other proteins implicated in axial flagellar protein export. Inner, cytoplasmic rod basal substructure, seen by negative-stain and quick-freeze replica electron microscopy, may gate such export. Lack of connectivity between the cytoplasmic rod and ring substructures places contacts between FliG and FliMFliN at the periphery of the basal body, proximal to the flagellar intramembrane ring particles. This topology is consistent with models where torque results from interaction of circumferential arrays of the switch complex proteins with the ring particles.