Pathology of benzalkonium chloride toxicity and its effect on body weight gain in broiler birds

Four groups comprising 16 broiler birds each were given benzalkonium chloride (BC) at 100, 300, 500 and 700 ppm in drinking water for 40 days and one group of 16 birds (control) was kept on plain water. Clinical signs in higher dose groups were respiratory distress, drooling of saliva, difficulty in deglutition, inappetence, apathy, lethargy and loss of body weight. Better body weight gain was recorded in 100 ppm dose rate. At 300 ppm, no significant body weight variation was recorded, whereas, at 500 and 700 ppm dose rates, significantly poor body weight gain was recorded. Major pathological changes were seen in 500 and 700 ppm groups, which exhibited formation of yellow diphtheritic plaques in the buccal cavity, swollen and pale commissures of beak and shortening of tongue. Minute necrotic and ulcerative foci were seen in oesophagus and crop. Hyperplastic and hypertrophic alterations were seen in mucosa of the upper digestive tract. Crop of 300 ppm group revealed formation of well developed epithelial nest with pseudoepitheliomatous hyperplasia at the margin of the lesion. Serum alanine transaminase, urea and uric acid in 500 and 700 ppm groups were elevated whereas no significant variations were observed in the 100 and 300 ppm groups. BC could enhance performance of broiler birds at 100 ppm dose rate. It should not be used beyond 300 ppm.

Studies on persistence of temephos in sandy loam soil under field and laboratory conditions

Persistence of temephos was studied in soils under field and laboratory conditions in sandy loam soil to evaluate the effect of moisture and formulations on persistence. The insecticide was applied as 50 EC and 1 % S.G. granules @1 kg a.i. ha-1 on surface of the soil' and residues were determined spectrophotometrically. The soil was fortified separately with dilute emulsion of EC and suspension of granular formulation at 5 ppm level and incubated at different moisture levels at 25:1:1 degrees C for 90 days. The residues of temephos from both the formulations persisted upto 55 days in soil when applied @1 kg a.i. ha(-1). In 40 days 92 and 91.43 per cent temephos was dissipated from soil treated with EC and granular formulations, respectively. There was no leaching or downward movement of the toxicant beyond 7.5 cm. The half-life of temephos under field condition for EC and granular formulations were 18.14 and 20.44 days, respectively. Statistically, there was no significant effect of two formulations of temephos on its persistence. But at three different moisture conditions viz. airdry, field capacity and sub-merged, the difference was significant at 5% level.

The Bouveret syndrome: an unusual complication of gallstone disease

We present a case of Bouveret's syndrome which is gastric outlet obstruction due to gallstone impaction in the duodenum. The paper also discusses the aetiology, presentation, methods of diagnosis and options for management of Bouveret's syndrome.

Uracil-DNA glycosylase-deficient yeast exhibit a mitochondrial mutator phenotype

Mutations in mitochondrial DNA (mtDNA) have been reported in cancer and are involved in the pathogenesis of many mitochondrial diseases. Uracil-DNA glycosylase, encoded by the UNG1 gene in Saccharomyces cerevisiae, repairs uracil in DNA formed due to deamination of cytosine. Our study demonstrates that inactivation of the UNG1 gene leads to at least a 3-fold increased frequency of mutations in mtDNA compared with the wild-type. Using a Ung1p-green fluorescent protein (GFP) fusion construct, we demonstrate that yeast yUng1-GFP protein localizes to both mitochondria and the nucleus, indicating that Ung1p must contain both a mitochondrial localization signal (MLS) and a nuclear localization signal. Our study reveals that the first 16 amino acids at the N-terminus contain the yUng1p MLS. Deletion of 16 amino acids resulted in the yUng1p-GFP fusion protein being transported to the nucleus. We also investigated the intracellular localization of human hUng1p-GFP in yeast. Our data indicate that hUng1p-GFP predominantly localizes to the mitochondria. Further analysis identified the N-terminal 16 amino acids as important for localization of hUng1 protein into the mitochondria. Expression of both yeast and human UNG1 cDNA suppressed the frequency of mitochondrial mutation in UNG1-deficient cells. However, expression of yUNG1 in wild-type cells increased the frequency of mutations in mtDNA, suggesting that elevated expression of Ung1p is mutagenic. An increase in the frequency of mitochondrial mutants was also observed when hUNG1 site-directed mutants (Y147C and Y147S) were expressed in mitochondria. Our study suggests that deamination of cytosine is a frequent event in S.cerevisiae mitochondria and both yeast and human Ung1p repairs deaminated cytosine in mitochondria.

Pyridoxine-dependent seizures: a case report and a critical review of the literature

Pyridoxine-dependent seizures are a recognized, although rare, cause of intractable seizures in neonates. Patients with this autosomal recessive disorder have recurrent seizures that are resistant to conventional anticonvulsants but respond dramatically to intravenous administration of pyridoxine. Life-long supplementation with pyridoxine is required to prevent seizure recurrence. In the absence of a biological marker for the disease, clinical diagnosis is often delayed and severe neurological sequelae are common. Herein, we report on the clinical course of a neonate with pyridoxine-dependent seizures. Delayed normalization of the electroencephalogram and a normal developmental outcome (at 15 months of age) on a dose of 10 mg/kg pyridoxine are distinctive features of the present case. We also review recent clinical observations and neurochemical studies that have added to our knowledge of this disorder.

Validation of a modified GTNM classification in peri-junctional oesophago-gastric carcinoma and its use as a prognostic indicator

AIM

A modified GTNM classification (with additional T and N subdivisions) has been used for many years. The aim of this paper was to validate this classification in a group of patients with oesophago-gastric carcinoma and to see if the more detailed information may be useful.

METHOD

The 3-year survival of 139 consecutive patients who survived resection has been related to the individual values of the modified and international classifications.

RESULTS

A step-wise reduction in the survival was found with increasing values of G, T, N and M. The international T3 value yielded a 17.7% survival rate, when subdivided, rates of 37.5%, 17.3% and 3.2% were found. The international N1 value yielded a rate of 12.9% which subdivided into rates of 25.0%, 18.7% and 7.5%.

CONCLUSION

If these results are repeated in a larger and more detailed study, this modified classification may provide added information when discussing prognosis and management.

Prevalence of self-reported symptoms of reproductive tract infections among recently pregnant women in Uttar Pradesh, India

This study examines the prevalence of self-reported reproductive tract infections (RTIs) and treatment seeking among married, recently pregnant women in Uttar Pradesh state, India. Associations between RTI symptom reporting and background characteristics are examined in a population-based sample of 18,506 married women with a pregnancy in the 3 years prior to a 1995 statewide survey. Logistic regression analyses are used to assess the effects of sociodemographic covariates on the probability of reporting an RTI symptom. Nearly one out of four women reports experiencing at least one RTI symptom, with the most common symptoms being abnormal vaginal discharge and pain during urination. Reporting of RTI symptoms significantly increases if the woman's last pregnancy did not end in a live birth or if she has low economic status. Symptom reports also increase with age and decrease with parity. Only one-third of women reporting an RTI symptom sought treatment. The results indicate that survey interviews can be a cost-effective option for measuring the magnitude of RTI symptoms experienced and identifying sociodemographic influences. The findings suggest the need for improved RTI screening procedures and treatment at health facilities in this populous state of northern India.

Antigens of Mycobacterium tuberculosis expressed during preclinical tuberculosis: serological immunodominance of proteins with repetitive amino acid sequences

Four antigens of Mycobacterium tuberculosis that are expressed in vivo after aerosol infection but prior to the development of clinical tuberculosis (TB) in rabbits were identified by immunoscreening of an expression library of M. tuberculosis genomic DNA with sera obtained 5 weeks postinfection. Three of the proteins identified, PirG (Rv3810), polymorphic GC-repetitive sequence (PE-PGRS; Rv3367), and proline-threonine repetitive protein (PTRP) (Rv0538), have multiple tandem repeats of unique amino acid sequences and have characteristics of surface or secreted proteins. The fourth protein, MtrA (Rv3246c), is a response regulator of a putative two-component signal transduction system, mtrA-mtrB, of M. tuberculosis. All four antigens were recognized by pooled sera from TB patients and not from healthy controls, confirming their in vivo expression during active infection in humans. Three of the antigens (PE-PGRS, PTRP, and MtrA) were also recognized by retrospective preclinical TB sera obtained, prior to the clinical manifestation of TB, from human immunodeficiency virus-TB patients, suggesting that they are potential candidates for devising diagnostic tests for active, preclinical TB.

HNPCC mutations in the human DNA mismatch repair gene hMLH1 influence assembly of hMutLalpha and hMLH1-hEXO1 complexes

Hereditary nonpolyposis colorectal cancer (HNPCC) is a common inherited form of neoplasia caused by germline mutations in DNA mismatch repair (MMR) genes. MMR proteins have been reported to associate with several proteins, including the human exonuclease 1 (hEXO1). We report here novel HNPCC-hMLH1 mutant proteins (T117M, Q426X and 1813insA) in Danish HNPCC patients. We demonstrate that these mutant HNPCC-hMLH1 proteins are unable to form complexes with hEXO1 and hPMS2 in vivo. The results indicate that mutations found in HNPCC gene carriers disrupt hMLH1-hEXO1 complex formation and hMutLalpha heterodimer assembly essential for MMR activity.

Inactivation of Saccharomyces cerevisiae OGG1 DNA repair gene leads to an increased frequency of mitochondrial mutants

The OGG1 gene encodes a highly conserved DNA glycosylase that repairs oxidized guanines in DNA. We have investigated the in vivo function of the Ogg1 protein in yeast mitochondria. We demonstrate that inactivation of ogg1 leads to at least a 2-fold increase in production of spontaneous mitochondrial mutants compared with wild-type. Using green fluorescent protein (GFP) we show that a GFP-Ogg1 fusion protein is transported to mitochondria. However, deletion of the first 11 amino acids from the N-terminus abolishes the transport of the GFP-Ogg1 fusion protein into the mitochondria. This analysis indicates that the N-terminus of Ogg1 contains the mitochondrial localization signal. We provide evidence that both yeast and human Ogg1 proteins protect the mitochondrial genome from spontaneous, as well as induced, oxidative damage. Genetic analyses revealed that the combined inactivation of OGG1 and OGG2 [encoding an isoform of the Ogg1 protein, also known as endonuclease three-like glycosylase I (Ntg1)] leads to suppression of spontaneously arising mutations in the mitochondrial genome when compared with the ogg1 single mutant or the wild-type. Together, these studies provide in vivo evidence for the repair of oxidative lesions in the mitochondrial genome by human and yeast Ogg1 proteins. Our study also identifies Ogg2 as a suppressor of oxidative mutagenesis in mitochondria.

Characterization of a two-component system, devR-devS, of Mycobacterium tuberculosis

By subtractive hybridization, we isolated genes, differentially expressed in virulent strain (dev), that are expressed at higher levels in the virulent Mycobacterium tuberculosis H37Rv strain in comparison to its avirulent counterpart, H37Ra, and consequently may be associated with the virulence phenotype of M. tuberculosis. A two-component system, devR-devS, was identified by DNA sequencing of a dev clone. DevR, the predicted gene product of devR, is a response regulator (RR) in the NarL/ UhpA subfamily of two-component systems. The devS gene product displayed homology with histidine protein kinases (HPKs) including UhpB, NarX and NarQ. The devR-devS locus is preceded by gene Rv3134c that encodes a putative alanine-aline- rich protein. This locus was conserved in M. tuberculosis and M. bovis BCG but not in other mycobacteria. A devR -lacZ transcription fusion demonstrated beta-galactosidase activity in M. smegmatis and in M. tuberculosis. The devR and devS genes were cotranscribed and the levels of their transcripts were lower in two isolates of the avirulent H37Ra strain in comparison to the virulent H37Rv strain of M. tuberculosis. The level of DevR protein was also lower in one of the H37Ra strains in comparison to the H37Rv strain. However, in a third isolate of H37Ra, RNA and protein expression was equivalent to that in the H37Rv strain. Electron microscopic immunogold analysis of M. tuberculosis grown in laboratory medium and within human monocytes revealed specific labelling for DevR protein within the bacteria and the phagosomal lumen of infected monocytes. These findings collectively suggest a potential role for devR-devS in the regulation of genetic programmes unique to the tubercle bacillus.

Human homolog of the MutY repair protein (hMYH) physically interacts with proteins involved in long patch DNA base excision repair

The human MutY homolog (hMYH) is a DNA glycosylase involved in the removal of adenines or 2-hydroxyadenines misincorporated with template guanines or 7,8-dihydro-8-oxodeoxyguanines. hMYH is associated in vivo with apurinic/apyrimidinic endonuclease (APE1), proliferating cell nuclear antigen (PCNA), and replication protein A (RPA) in HeLa nuclear extracts as shown by immunoprecipitation and Western blotting. However, binding of hMYH to DNA polymerases beta and delta was not detected. By using constructs containing different portions of hMYH fused to glutathione S-transferase, we have demonstrated that the APE1-binding site is at a region around amino acid residue 300, that the PCNA binding activity is located at the C terminus, and that RPA binds to the N terminus of hMYH. A peptide consisting of residues 505-527 of hMYH that contains a conserved PCNA-binding motif binds PCNA, and subsequent amino acid substitution identified Phe-518 and Phe-519 as essential residues required for PCNA binding. RPA binds to a peptide that consists of residues 6-32 of hMYH and contains a conserved RPA-binding motif. The PCNA- and RPA-binding sites of hMYH are further confirmed by peptide and antibody titration. These results suggest that hMYH repair is a long patch base excision repair pathway.

Quality of underground waters of semi-arid tract and their impact on soil

Fifty eight (58) irrigation water samples were collected from 58 villages of Chirawa Block, Jhunjhunu district. The cations and anions in irrigation waters were found in the order of Na+ > Cl- > CO3(2+) + HCO3 > Ca2+ (+) Mg2+ > SO4(2)- > K+. SAR and RSC of the waters ranged between 2.54 to 17.21 and 0.10 to 6.0 meq/l, respectively. pHc and adj. SAR of the waters ranged between 7.1 to 8.2 and 4.0 to 36.0 respectively. EC of irrigation water has significant positive non-significant correlation with EC of soil and weak positive correlation with pH of soil. Significant positive correlation was found in SAR (0.53) and RSC (0.47) of irrigation water with pH of soil.

The Saccharomyces cerevisiae Sln1p-Ssk1p two-component system mediates response to oxidative stress and in an oxidant-specific fashion

Aerobic organisms experience oxidative stress due to generation of reactive oxygen species during normal aerobic metabolism. In addition, environmental gamma and UV radiation, as well as several chemicals also generate reactive oxygen species, which induce oxidative stress. Thus oxidative stress constitutes a major threat to organisms living in aerobic environments. Oxidative stress induces the expression of several genes in yeast Saccharomyces cerevisiae. However, the primary sensor(s) that trigger the response is unknown. This study demonstrates that primary sensors of osmotic stress, the Sln1p-Ssk1p two-component proteins, are involved in sensing oxidative stress specifically induced by hydrogen peroxide and diamide, but not by other oxidants used in the study. Wild type and sln1-ssk1 mutant were treated with hydrogen peroxide, diamide, menadione, UV, and gamma-radiation. Results show that sln1-ssk1 mutant is only sensitive to hydrogen peroxide and diamide but not to other oxidants. S. cerevisiae contains an additional cell surface osmosensor, Sho1p, that targets the osmotic signal to Hog1p. Data is presented that shows Sho1 and Hog1 proteins are also involved in signaling oxidant-specific cellular damage. Furthermore, it is demonstrated that expression of the mammalian homolog of Hog1p provides protection from oxidative stress induced by hydrogen peroxide. These results suggest that Sln1p-Ssk1p and Sho1p signal transduction pathways participate in oxidative stress response. However, this response to oxidative stress is limited to specific oxidants.

Use of herbal therapies by adults seen in an ambulatory care research setting: an exploratory survey

OBJECTIVE

To identify and characterize patterns of use of herbal products among patients participating in selected research clinics.

DESIGN

Survey of three National Institutes of Health (NIH) ambulatory care research clinics.

SUBJECTS

Convenience sample of 490 adult patients (168 male, 322 female) attending rheumatology, liver, and endocrinology/metabolic research clinics.

RESULTS

Of the patients surveyed, 16.7%: (n = 82) reported using herbs. There were no significant sociodemographic differences between herb and nonherb users. Indications for herb use differed among the disease groups; patients in the endocrine and rheumatology clinics were taking herbs predominantly for "energy" or "wellness"; those attending the liver clinic tended to use herbal therapies as treatment for their disease. Mean and median monthly expenditure for herbal products was $30 and $10, respectively. There was a significant positive correlation between number of herbs used and use of other dietary supplements (p < 0.0001).

CONCLUSIONS

One in six patients in ambulatory clinical research settings may be taking herbal products in addition to prescribed treatment. This figure is lower than in the general population, possibly because the patients may stop using herbs when participating in a research project. Although empirical evidence on the beneficial or adverse effects of herb therapy alone or in combination with drug therapies is limited, clinical researchers should be aware of the potential for confounding clinical trial results.

Assessment of oxidative stress and effect of antioxidant supplementation during radiotherapy in carcinoma of upper digestive tract

Oxidative stress was studied by estimating plasma levels of malondialdehyde (MDA), beta carotene, vitamin E and erythrocytic superoxide dismutase(E-SOD) activity in 50 cases of carcinoma of upper digestive tract which included carcinoma of oral cavity, pharynx and oesophagus. While plasma MDA level was found to be increased (3.5±1.0 nmole/ml), a significant decrease in beta carotene (81.2±14.5mg%), vitamin E (8.5±1.1 mg/L) level and E-SOD activity (657.0±80.6 U/G Hb) were observed in carcinoma of upper digestive tract. Patients were treated with radiotherapy which itself was toxic enough and produced its deleterious effects by generation of reactive oxygen species (ROS). As antioxdiants can detoxify ROS, beneficial effect if any, of antioxidant administration during radiotherapy was studied in two groups of patients, group A (n=5, supplemented with antioxidants) and group B (n=5, without antioxidant supplementation). Plasma MDA level was found to be elevated in both the groups but the increase in group B was significant, compared to pretreatment level. Further, body weight was found to be significantly decreased in group B patients, which was maintained in group A patients. Moreover, group A patients showed significant elevation in beta carotene concentration, thus showing beneficial effect of administration of antioxidants during radiotherapy without disturbing the desirable therapeutic effect of radiotherapy.

Fluorescence polarization for monitoring ribozyme reactions in real time

Fluorescence polarization has been used recently to monitor diverse macromolecular interactions. In this report, the application of fluorescence polarization has been extended to monitor ribozyme reactions in real time. With fluorescently labeled substrate RNAs, group I ribozyme ligation and hammerhead ribozyme cleavage reactions were studied by fluorescence polarization in substrate excess (multiple turnover) conditions. These results also show that fluorescently labeled RNAs remain active substrates for ribozymes. Furthermore, a direct comparison of fluorescence polarization with fluorescence resonance energy transfer showed that both techniques were comparable for monitoring ribozyme reactions.

The human cyclin B1 protein modulates sensitivity of DNA mismatch repair deficient prostate cancer cell lines to alkylating agents

DNA damage caused by alkylating agents results in a G2 checkpoint arrest. DNA mismatch repair (MMR) deficient cells are resistant to killing by alkylating agents and are unable to arrest the cell cycle in G2 phase after alkylation damage. We investigated the response of two MMR-deficient prostate cancer cell lines DU145 and LNCaP to the alkylating agent MNNG. Our studies reveal that DU145 cancer cells are more sensitive to killing by MNNG than LNCaP. Investigation of the underlying reasons for lower resistance revealed that the DU145 cells contain low endogenous levels of cyclin B1. We provide direct evidence that the endogenous level of cyclin B1 modulates the sensitivity of MMR-deficient prostate cancer cells to alkylating agents.

Comparison of in house polymerase chain reaction with conventional techniques for the detection of Mycobacterium tuberculosis DNA in granulomatous lymphadenopathy

AIMS

To evaluate the usefulness of the devR based polymerase chain reaction (PCR) in the detection of Mycobacterium tuberculosis in lymph node aspirates and tissues of lymphadenitis and to compare PCR with conventional diagnostic techniques.

SUBJECTS AND METHODS

Coded specimens of fine needle aspirates and biopsies from 22 patients with tuberculous lymphadenitis, 14 patients with non-tubercular lymphadenitis, and nine patients with granulomatous lymphadenitis were processed and subjected to analysis by PCR, smear microscopy, M tuberculosis culture, histology, and cytology.

RESULTS

Tuberculous lymphadenitis was correctly diagnosed by PCR in 18 patients, by culture in five patients, by histology in 13 patients, and by cytology in seven patients. PCR gave two false positive results in 14 patients with non-tubercular lymphadenitis. The sensitivity of the conventional techniques was significantly higher with biopsies (17 of 22 specimens; 77%) than with fine needle aspirates (nine of 22 specimens; 41%). However, the sensitivity of PCR was not significantly higher with biopsies (68%) in comparison with fine needle aspirates (55%). The sensitivity of either biopsy PCR or fine needle aspirate PCR was not significantly different from that of either histology combined with culture or cytology combined with culture. The overall combined specificity of PCR was 86%. Mycobacterium tuberculosis DNA was detected in six of nine patients with granulomatous lymphadenitis.

CONCLUSION

PCR is the most sensitive single technique available to date for the demonstration of M tuberculosis in specimens derived from patients with a clinical suspicion of tuberculous lymphadenitis. The value of PCR lies in its use as an adjunct test in the diagnosis of tuberculous lymphadenitis, particularly in those patients where conventional methods fail. Because fine needle aspiration is not an invasive procedure, it is the procedure of choice, and PCR should be performed initially on these samples. Excisional biopsy histology and PCR should be recommended only for patients in whom fine needle aspirate PCR is negative or when there is discrepancy with the clinical impression.

Sexual behaviors and reproductive health outcomes: associations with wife abuse in India

CONTEXT

Wife abuse has been associated with a variety of health concerns. Associations between abuse and reproductive health in India are not well known.

OBJECTIVE

To examine relationships between men's reports of wife abuse and reproductive health issues in northern India.

DESIGN

Structured face-to-face interviews were conducted as part of the male reproductive health supplement of the PERFORM System of Indicators Survey, a systematic multistage survey conducted in 1995-1996.

SETTING

The northern state of Uttar Pradesh, one of the least developed states in India.

PARTICIPANTS

A total of 6632 married men aged 15 to 65 years who lived with their wives and completed all survey questions for the study variables reported here.

MAIN MEASURES

Physically and sexually abusive behaviors toward wives, sexual activities outside marriage, sexually transmitted disease (STD) symptoms, contraception use, unplanned pregnancies, and sociodemographic characteristics.

RESULTS

Fifty-four percent of men reported not abusing their wives, while 17% reported physically but not sexually abusing their wives, 22% reported sexual abuse without physical force, and 7% reported sexual abuse with physical force. Abuse was more common among men who had extramarital sex (for sexual abuse using force: odds ratio [OR], 6.22; 95% confidence interval [CI], 3.98-9.72). Similarly, men who had STD symptoms were more likely to abuse their wives (with current symptoms: OR, 2.43; 95% CI, 1.73-3.42). Unplanned pregnancies were significantly more common among wives of abusive men, especially sexually abusive men who used force (OR, 2.62; 95% CI, 1.91-3.60).

CONCLUSIONS

Wife abuse appears to be fairly common in northern India. Our findings that abusive men were more likely to engage in extramarital sex and have STD symptoms suggest that these men may be acquiring STDs from their extramarital relationships, thereby placing their wives at risk for STD acquisition, sometimes via sexual abuse. These abusive sexual behaviors also may result in an elevated rate of unplanned pregnancies.

Mitochondrial DNA determines the cellular response to cancer therapeutic agents

Mutations in the mitochondrial genome leading to mitochondrial dysfunction have been reported in a variety of cancers. However, the potential implication of these findings in the cellular response to cancer therapeutic agents is unclear. To examine the importance of mitochondrial DNA (mitDNA) encoded functions in cancer therapeutic response, we determined the clonogenic survival of HSL2 (Rho+, HeLa subline), and its derivative cell line lacking mitDNA (Rho0) after exposure to different anticancer agents. We found that isogenic Rho0 cells lacking mitDNA were extremely resistant to adriamycin and photodynamic therapy (PDT) induced cell death, whereas the Rho+ cell line was sensitive. However, there was no measurable difference in the responses of these cell lines to either alkylating agent or gamma-radiation. We show that the development of resistance to adriamycin was not due to changes in apoptotic cell death, cell cycle response or to the uptake of adriamycin in isogenic Rho0 cells. We also demonstrate that exposure of HeLa cells to adriamycin leads to mutations in mitDNA. These studies provide direct evidence that mitDNA plays an important role in cellular sensitivity to cancer therapeutic agents.

Outcome in patients with colorectal cancer managed by surgical trainees

BACKGROUND

The surgeon is an important variable that influences outcome following colorectal cancer surgery. Operative training of suitable quality and quantity is essential if intersurgeon variation is to be reduced. The aim of this study was to examine the outcome of colorectal cancer surgery when a high proportion of the operations were performed by trainee surgeons.

METHODS

A prospective 7-year (1989-1996) audit of 306 consecutive colorectal cancers referred to a single general surgeon with a colorectal interest was carried out. The outcome (anastomotic leakage, 30-day mortality rate, local recurrence and cancer-related survival) of operations performed by the consultant was compared with that of his trainees.

RESULTS

Some 245 (92.5 per cent) of 265 patients undergoing laparotomy had a resection. Seventy (28.6 per cent) and 67 (27.3 per cent) of operations were performed by supervised and independent trainees respectively. There was no difference between the consultant, supervised and independent trainees for 30-day mortality rate (6.5, 6 and 4 per cent respectively), clinical anastomotic leakage rate (9, 2 and 5 per cent) and local recurrence rate (2, 3 and 7 per cent). There was no difference between the three groups for adjusted 5-year disease-related survival rates.

CONCLUSION

Properly supervised trainees can resect a high proportion of colorectal cancers without compromising immediate outcome or long-term survival. Presented in part to the annual meeting of the Association of Surgeons of Great Britain and Ireland, Bournemouth, UK, April 1997, and published in abstract form as Br J Surg 1997; 84(Suppl): 56

Rapid kinetic characterization of hammerhead ribozymes by real-time monitoring of fluorescence resonance energy transfer (FRET)

In established methods for analyzing ribozyme kinetics, radiolabeled RNA substrates are primarily used. Each data point requires the cumbersome sampling, gel electrophoretic separation, and quantitation of reaction products, apart from the continuous loss of substrate by radioactive decay. We have used stable, double fluorescent end-labeled RNA substrates. Fluorescence of one fluorophore is quenched by intramolecular energy transfer (FRET). Upon substrate cleavage, both dyes become separated in two RNA products and fluorescence is restored. This can be followed in real time and ribozyme reactions can be analyzed under multiple (substrate excess) and under single (ribozyme excess) turnover conditions. A detailed comparison of unlabeled, single, and double fluorescent-labeled RNAs revealed moderate kinetic differences. Results with two systems, hammerhead ribozymes in I/II (small ribozyme, large substrate) and in I/III format (large ribozyme, small substrate), are reported.

Utility of PCR assay in diagnosis of en-plaque tuberculoma of the brain

This is the first report of a case in which diagnosis of en-plaque tuberculoma on the basis of magnetic resonance imaging (MRI) findings was confirmed by a Mycobacterium tuberculosis complex-specific PCR assay of cerebrospinal fluid. The accuracy of the diagnosis was supported by good response to antitubercular drugs, which was shown by repeat MRI studies performed after treatment.

Husbands' reproductive health knowledge, attitudes, and behavior in Uttar Pradesh, India

To enhance the reproductive health status of couples in developing countries, the knowledge, attitudes, and behavior of both women and men must be investigated, especially where women depend on men for the decision to seek care. This study analyzes data from a survey of 6,727 husbands from five districts in the northern state of Uttar Pradesh, India. Data are presented on men's knowledge of women's health and on their own sexual behavior outside the context of marriage, on their perceptions of sexual morbidity and their attempts at treatment for specific conditions, and on their opinions concerning the social role of wives. Findings indicate that men know little about maternal morbidity or sexual morbidity conditions. Few husbands reported that they had had sexual experience outside of marriage and the majority of these few said they had had such a relationship with more than one partner. Of men who said they had had reproductive morbidity symptoms, many said they had not sought treatment. Men's views concerning the role of wives indicate a low level of women's autonomy in this region of India. Results indicate a pressing need for reproductive health education that targets both women and men in Uttar Pradesh.

Longevity of lobsters is linked to ubiquitous telomerase expression

Mammals have high growth rates in embryonic and juvenile phases and no growth in adult and senescent phases. We analyzed telomerase activity in a fundamentally different animal which grows indeterminately. Lobsters (Homarus americanus) grow throughout their life and the occurrence of senescence is slow. A modified TRAP assay was developed and the lobster telomeric repeat sequence TTAGG was determined. We detected telomerase activities which were dependent on RNA and protein components, required dGTP, dATP and dTTP, but not dCTP. Telomerase products with a five nucleotide periodicity were generated. High telomerase activities were detected in all lobster organs. We conclude that telomerase activation is a conserved mechanism for maintaining long-term cell proliferation capacity and preventing senescence, not only in cellular models or embryonic life stages but also in adult multicellular organisms.

Regulation of telomerase activity in quiescent immortalized human cells

Telomerase is a key enzyme in carcinogenesis; telomerase activity has been found in more than 90% of human tumors. Understanding the regulation of this enzyme will improve our knowledge of tumor biology and may lead to novel strategies in cancer therapy. We examined effects of growth arrest on telomerase activity in the human immortalized cell lines U 937 (lymphoma) and L 428 (Hodgkin's disease). Cells were starved by serum depletion for 4 days. After readdition of serum, a recovery phase followed. Cell proliferation was monitored with the monoclonal antibody Ki-S5. In the absence of serum, telomerase levels declined fivefold. After serum readdition, recovery to threefold increased level was observed. Furthermore, the prevalence of telomerase-positive cells in normal tissues is an important issue for understanding tumorigenesis. Our TRAP assay is robust against false positives and in mixed cell samples, we found a rather limited sensitivity of the telomere repeat amplification protocol (TRAP) assay. This means that adequate screenings for telomerase-positive somatic cells have to include enrichment steps.

Germ cell tumour of testis

Germ cell tumour, though rare, represents most common malignancy among young men aged between 15 to 35 years. In 1990's dramatic improvement has taken place in survival rate of testicular tumours (from 10% in 1970's and 90% in 1990's). This has been possible because of effective diagnostic techniques, accurate monitoring with biological markers and use of effective platinum based combination chemotherapy in its management. The most significant improvement in survival rate has occurred in advanced stage germ-cell tumours. Seminomas are sensitive to radiation therapy and NSGCT (Non Seminomatous Germ Cell Tumours). are effectively treated by combination chemotherapy of 3 drugs of which Bleomycin is most expensive and many patient can not afford it and so compliance is poor. In the present series we have tried only 2 drug regimen consisting of Platinum and Etoposide (PE). Since January 1992 to December 1994, 40 cases of testicular tumours were treated. 16 cases received PEB regimen and 24 cases were treated by PE regimen of which only 6 cases in the former and 20 cases in the later group completed the scheduled course. Patients were given 6 cycles of PE regimen (inj. Platinum 20 mg/m2 D1-D5, VP-16 (ETOPOSIDE), 100 MG/M2 1.V. D1-D5) repeated every three weeks. Final evaluation was done in June 1996. 17/20 (85%) patients on PE regiment exhibited complete regression of the disease by the end of June 1996, I was lost to follow up, and 2 of them had the disease in progressive stage and were considered for another regimen. 18 months disease free survival was 85%. Table I. Royal Marsden Staging System Stage I: Disease econfined to testes Stage II: Intradiaphragmatic node involvement A: Less than 2 cm B: 2-5 cm C: Greater than 5 cm Stage III: Supradiaphragmatic node involvement Stage IV: Extralymphatic disease Lung, Liver, Bone etc.

Audit of colorectal cancer surgery by non-specialist surgeons

BACKGROUND

Some authorities recommend that colorectal cancer should be treated in specialist units but evidence that non-specialist units demonstrate comparatively poor results may be lacking.

METHODS

Between 1987 and 1991, 267 patients were operated on by four general surgeons, none of whom was a specialist in colorectal surgery. Procedure-related complications, postoperative mortality and disease-related survival rates were analysed.

RESULTS

There were four cases of intraperitoneal sepsis (1 per cent) and five of 189 patients (3 per cent) had clinical anastomotic dehiscence; there was no case of wound dehiscence. The postoperative mortality rate after elective and emergency surgery was 2 and 13 per cent respectively. The 5-year disease-related survival rate for curative and palliative surgery was 67 and 9 per cent respectively. There were no significant differences between the surgeons.

CONCLUSION

Disease-related variables such as early-stage disease and fewer patients presenting as emergencies may have a greater favourable influence on ultimate survival than surgeon-related variables.

A sequence in the N-terminal region of human uracil-DNA glycosylase with homology to XPA interacts with the C-terminal part of the 34-kDa subunit of replication protein A

Uracil-DNA glycosylase releases free uracil from DNA and initiates base excision repair for removal of this potentially mutagenic DNA lesion. Using the yeast two-hybrid system, human uracil-DNA glycosylase encoded by the UNG gene (UNG) was found to interact with the C-terminal part of the 34-kDa subunit of replication protein A (RPA2). No interaction with RPA4 (a homolog of RPA2), RPA1, or RPA3 was observed. A sandwich enzyme-linked immunosorbent assay with trimeric RPA and the two-hybrid system both demonstrated that the interaction depends on a region in UNG localized between amino acids 28 and 79 in the open reading frame. In this part of UNG a 23-amino acid sequence has a significant homology to the RPA2-binding region of XPA, a protein involved in damage recognition in nucleotide excision repair. Trimeric RPA did not enhance the activity of UNG in vitro on single- or double-stranded DNA. A part of the N-terminal region of UNG corresponding in size to the complete presequence was efficiently removed by proteinase K, leaving the proteinase K-resistant compact catalytic domain intact and fully active. These results indicate that the N-terminal part constitutes a separate structural domain required for RPA binding and suggest a possible function for RPA in base excision repair.

Biodistribution of cocaine during perinatal period in rats

Differences in cocaine-induced central nervous system toxicity in pregnant and postpartum rats have been observed. For example, a 20 mg/kg, intraperitoneal dosage of cocaine that was tolerated during pregnancy caused tonic-clonic convulsions and death during the postpartum period. In the present study, biodistribution of cocaine during different perinatal periods was investigated to understand the differences in toxicity. Nonpregnant, 22-day pregnant, and postpartum rats were injected with 3H cocaine (12 mg/20 mu ci/kg, i.v.). Rats were sacrificed under ether anesthesia at predetermined time intervals. Brain, serum, fetal brain and placenta (from pregnant rats) samples were isolated, solubilized, and counted in a scintillation counter for radioactivity. Peak levels of cocaine were observed at 15 and 60 minutes after injection in maternal serum and brain, respectively, in 22-day pregnant rats. However, peak levels of cocaine were observed at 30 minutes after the injection in placental and fetal brain tissues from 22-day pregnant rats. Cocaine level of brain was elevated in all postpartum rats compared to nonpregnant and pregnant rats. These results indicated that higher levels of cocaine is distributed to brain after delivery compared to the nonpregnant and pregnant rats which may explain increased CNS toxicity during postnatal period.

Effect of chronic fenvalerate (synthetic pyrethroid) intoxication on the immune response of goats to Brucella abortus strain 19 vaccine

Fenvalerate, a widely used pesticide, was administered orally to goats at a dose rate of 15 mg/kg body weight, daily for 270 days. After 90 days of dosing, the animals, together with appropriate controls, were vaccinated with Brucella abortus strain 19. The fenvalerate reduced both the humoral and cell-mediated immune responses, as assessed by the standard tube agglutination test and delayed hypersensitivity test, respectively.

Reactivation of photosynthesis in the photoinhibited green alga Chlamydomonas reinhardtii: Role of dark respiration and of light

Effect of quality, quantity and minimum duration of light on the process of recovery was investigated in the photoinhibited cells of the green alga Chlamydomonas reinhardtii. Complete and rapid reactivation of photosynthesis took place in diffuse white light of 25 μmol m(-2) s(-1). The recovery was partial (< 10%) in the dark. Far red (725 nm), red (660 nm) and blue light (480 nm) in the range of 10 to 75 μmol m(-2) s(-1) did not enhance the process of reactivation. Photoinhibited cells incubated in dark for 15 min when exposed for 5 min to diffuse light (25 μmol m(-2) s(-1)) showed complete reactivation. Even exposure of 15 min dark incubated photoinhibited cells to photoinhibitory light (2500 μmol m(-2) s(-1)) for 5 s fully regained the photosynthesis. The study indicated a very precise and triggering effect of light in the process of reactivation. The dark respiratory inhibitor KCN and uncouplers FCCP and CCCP increased the susceptibility of C. reinhardtii to photoinhibition and also prevented photoinhibited cells to reactivate fully even after longer period of incubation under suitable reactivating conditions. Of the various possibilities envisaged to assign the role of dark respiration in recovery process, supply of ATP by mitochondrial respiration appeared sound and pertinent.

Clinical and etiological profile of ataxic hemiparesis

We studied the clinical profile and etiology of 28 cases of ataxic hemiparesis. After a detailed neurological examination, CT scan brain (plain and after IV contrast) was done in all. Age ranged from 18 to 80 years. Acute onset of symptoms was in 22, while 6 had insidious onset. 18 patients had major infarct, while 4 patients had lacunar infarct. 2 patients were found to have haematoma (1 following head injury) and 1 each had tuberculoma, meningioma, glioma and toxoplasma granuloma. The lesions were seen in various parts of brain stem, thalamus, basal ganglion, internal capsule and frontal, parietal and temporal region. Heterogeneity as regards to etiology and localisation is being highlighted.

Vasopressor responses in autosomal dominant cerebellar ataxia

Thirteen patients with autosomal dominant cerebellar ataxia were investigated for autonomic functions using standard tests. Patients showed no significant reduction in parasympathetic responses as measured by heart rate response to slow breathing and Valsalva manoeuvre. Measurement of blood pressure response to isometric exercise, cold exposure and 70 degrees head-up tilt showed a significant decrease in sympathetic pressor response.

SUPRACLAVICULAR FIRST RIB RESECTION FOR TREATMENT OF THORACIC OUTLET SYNDROME

Twelve patients with thoracic syndrome were operated during a 15 month period. Eleven patients had features of neurogenic thoracic outlet syndrome, while one presented with arterial ischemia due to distal embolism. The diagnosis was based on the characteristic history and positive stress tests. Cervical rib was present in 7 patients. Abnormal nerve conduction studies were present in 7 out of 8 cases. Supraclavicular first rib resection was done in all patients in view of the severity of symptoms. If present, the cervical rib was also excised. There was no major operative complication. Eleven out of twelve patients reported relief of symptoms. Thoracic outlet syndrome is not an uncommon disorder and often goes undiagnosed. Resection of first rib via the supraclavicular approach gives good results in majority of the patients who have incapacitating symptoms.

Design of hammerhead ribozymes to distinguish single base changes in substrate RNA

Hammerhead ribozymes are attractive tools in antisense gene inactivation because of their catalytic cleavage of target molecules. High sequence discrimination should be possible, since the cleavage efficiencies were already significantly reduced, if single base changes in substrate RNA introduce mismatches next to the cleavage site. This was observed at the first innermost base pair in helix I and the two innermost base pairs in helix III. In addition to its position, the nature of the mismatch pair was important.

Distribution of time of first birth in presence of social customs regulating physical separation and coital frequency

The interval between marriage and the first birth in India, particularly in rural areas, is much longer than what is observed in western countries. In eastern Uttar Pradesh, the mean interval is observed to be even longer, possibly due to traditional customs such as the female partner's visits to her parents in the early years of marriage and the smaller chance of coition because of the observance of rigid intercourse taboos. Thus the models to explain the length of the interval of marriage to first birth proposed by Western demographers, which assume that the period of cohabitation between marriage and first birth is uninterrupted, often do not describe the data satisfactorily when applied to rural India. In this paper a model to describe data on first birth interval is proposed that takes account of the distributions of timing and periods of physical separation and variation in fecundity with effective marriage duration.