Predicting non-muscle invasive bladder cancer outcomes using artificial intelligence: a systematic review using APPRAISE-AI

Accurate prediction of recurrence and progression in non-muscle invasive bladder cancer (NMIBC) is essential to inform management and eligibility for clinical trials. Despite substantial interest in developing artificial intelligence (AI) applications in NMIBC, their clinical readiness remains unclear. This systematic review aimed to critically appraise AI studies predicting NMIBC outcomes, and to identify common methodological and reporting pitfalls. MEDLINE, EMBASE, Web of Science, and Scopus were searched from inception to February 5th, 2024 for AI studies predicting NMIBC recurrence or progression. APPRAISE-AI was used to assess methodological and reporting quality of these studies. Performance between AI and non-AI approaches included within these studies were compared. A total of 15 studies (five on recurrence, four on progression, and six on both) were included. All studies were retrospective, with a median follow-up of 71 months (IQR 32-93) and median cohort size of 125 (IQR 93-309). Most studies were low quality, with only one classified as high quality. While AI models generally outperformed non-AI approaches with respect to accuracy, c-index, sensitivity, and specificity, this margin of benefit varied with study quality (median absolute performance difference was 10 for low, 22 for moderate, and 4 for high quality studies). Common pitfalls included dataset limitations, heterogeneous outcome definitions, methodological flaws, suboptimal model evaluation, and reproducibility issues. Recommendations to address these challenges are proposed. These findings emphasise the need for collaborative efforts between urological and AI communities paired with rigorous methodologies to develop higher quality models, enabling AI to reach its potential in enhancing NMIBC care.

Existing trends and applications of artificial intelligence in urothelial cancer A scoping review

INTRODUCTION

The use of artificial intelligence (AI) in urology is gaining significant traction. While previous reviews of AI applications in urology exist, there have been few attempts to synthesize existing literature on urothelial cancer (UC).

METHODS

Comprehensive searches based on the concepts of "AI" and "urothelial cancer" were conducted in MEDLINE , EMBASE , Web of Science, and Scopus. Study selection and data abstraction were conducted by two independent reviewers. Two independent raters assessed study quality in a random sample of 25 studies with the prediction model risk of bias assessment tool (PROBAST) and the standardized reporting of machine learning applications in urology (STREAM-URO) framework.

RESULTS

From a database search of 4581 studies, 227 were included. By area of research, 33% focused on image analysis, 26% on genomics, 16% on radiomics, and 15% on clinicopathology. Thematic content analysis identified qualitative trends in AI models employed and variables for feature extraction. Only 19% of studies compared performance of AI models to non-AI methods. All selected studies demonstrated high risk of bias for analysis and overall concern with Cohen's kappa (k)=0.68. Selected studies met 66% of STREAM-URO items, with k=0.76.

CONCLUSIONS

The use of AI in UC is a topic of increasing importance; however, there is a need for improved standardized reporting, as evidenced by the high risk of bias and low methodologic quality identified in the included studies.

Continued Mentorship Program for MBBS Students during COVID-19 Pandemic in Virtual Mode: A Questionnaire-based Observational Study

Introduction: The Coronavirus Disease-2019 (COVID-19) pandemic situation propelled the regular student mentorship program onto a virtual mode. Various surveys and studies have uncovered the ramifications on mental health and academic upheaval caused by the changing academic regulations and protocols. Aim: To evaluate the perception of mentors and mentees regarding the utility of virtual mentorship and to deduce barriers in continuing virtual mode mentorship program for 1st-year medical students. Materials and Methods: The present observational study was conducted at Sri Siddhartha Institute of Medical Sciences and Research Centre, from April-June 2020. A feedback form was administered to all participants after two months of the online mentorship program, via a semistructured questionnaire. The questionnaire had four open and eight close-ended responses for mentees. The contents were related to the frequency of meetings, mode of communication, perceived barriers, and futility of course, along with one open and five close-ended responses for mentors on barriers to effective conduct and perceived level of the mentoring relationship forged with students. A total of 12 mentors and 125 students responded. Results: It was observed that 96% of mentees felt that the program helped to fight alienation and stay connected, 89.6% felt inspired to study and 83% felt oriented to the online teaching programs. Both 91.7% of mentors and 82.4% of mentees asked for better applications, connectivity, and network support. In fact, the major barrier to effective communication was quoted as being poor network connectivity and applications support (47%). A comparable trend was noted among both mentees and mentors with respect to the program being rated good and above (91.7% mentors and 85.6% mentees). Hence, in the observational study, via thematic analysis and content analysis of qualitative data, two points were observed-1. The virtual mentorship program helped mentees to get emotionally and academically connected, cleared their doubts, and helped to reduce stress. 2. Poor technical and connectivity support were deduced as major barriers to the successful conduct of virtual mentorship. Conclusion: A well-structured virtual mentorship program guides the mentors to effectively chaperone mentees through a stressful uninterrupted academic course period, enhance academic performances and help alleviate the feeling of alienation.

Effects of L-ascorbic acid on two cycles of cisplatin-induced DNA double-strand breaks and phosphorylation of p53 in the liver

Cisplatin, a commonly used anticancer drug, was studied to investigate its effects on structure, DNA damage and p53 along with the possible protective effects of L-ascorbic acid in the liver. Adult male BALB/c mice were treated with 0, 10 mg/kg L-ascorbic acid and two cycles of cisplatin 1 mg/kg/2.5 mg/kg with or without L-ascorbic acid (17 days recovery period between the cycles) and the livers were collected at 72 h after the last exposure. Structural damage was analyzed in Masson's trichrome and Hortega's silver stained liver tissues. The DNA double-strand breaks with duplex 3' overhangs and 5' P-blunt ends were labeled by in situ oligo ligation by using hairpin oligonucleotide probes. The expression of p53 and phosphorylated p53 (p-p53) was detected by immunohistochemistry. Structural changes such as vacuolization of hepatocytes, pyknosis, infiltration of leukocytes and pericentral fibrosis were observed without any protection from L-ascorbic acid. The reticular fibrous framework was affected and the incidence of Kupffer cells was decreased. Cisplatin induced the DNA double-strand breaks (p<0.001); however, the latter appeared in a p53-independent, but p-p53-dependent manner. L-ascorbic acid showed significant protective effect on cisplatin-induced DNA damage (p<0.001). Cisplatin also enhanced p53 phosphorylation in a dose-dependent manner and L-ascorbic acid reduced this biochemical change only in 1 mg/kg group. In conclusion, cisplatin-induced structural changes are not, but the DNA damage and phosphorylation of p53 are, significantly, but not completely, alleviated by L-ascorbic acid.

Methyl parathion induces the formation of symplasts by round spermatid fusion and alters the biochemical parameters in the testis

Methyl parathion (MP: O,O-dimethyl-O-4-nitrophenyl phosphorothioate) is an organophosphate pesticide used in agriculture to protect a variety of crops. Food stuffs such as fruits and vegetables could be contaminated with MP, which may be a potential route of exposure. Previous studies have shown that MP is a reproductive toxicant in animal models. The present study was designed to investigate the mechanism of symplast formation and biochemical changes that occur in the testis, following MP exposure. MP was treated to adult male Wistar rats (N=5/dose/sample time) as follows. Experiment 1 - 0, 0.75 or 1.5mg/kg/d i.p. for 25 days and experiment 2 - 0 or 3.5mg/kg/d p.o. for 25 days and sacrificed on Day 17, after the last exposure. Light microscopic examination of testis was made to evaluate the structural changes and also to establish a process of symplast formation and destruction. Quantitative biochemical estimations were made in the testis for acid phosphatase (ACP), cholesterol, total protein, uric acid, and lactate dehydrogenase (LDH). MP induced structural changes in the testis in consensus with the previous studies. The symplasts were found in the testes in experiment 1. Those cells were formed due to the cell fusion of round spermatids. The symplasts were degenerated by nuclear fragmentation. The nuclear fragments were extruded from the symplasts leaving behind only the eosinophilic cytoplasm. The cell fusion and multinucleated giant cell formation was the reason for MP induced tubular atrophy. Number of tubules with symplasts increased in experiment 1 in a dose-dependent pattern. Johnsen's scores also decreased in a dose-dependent manner in experiment 1 indicating a dose-dependent tubular destruction. The ACP, cholesterol, total protein, and LDH levels decreased in both experiments against their respective controls, whereas the uric acid level decreased in experiment 1 and increased in experiment 2 (P<0.01-0.001). The effects in experiment 1 were dose-dependent. In conclusion, MP induces the formation of symplasts by cell fusion of round spermatids, which is a process involved in tubular atrophy and also induces biochemical changes in the testis.

The effects of carbamazepine on sperm morphology in wistar rats

Carbamazepine (5 H-dibenz (b, f) azepine-5-carboxamide), is an antiepileptic drug which is expected to be administered regularly over a substantial part of patients lifetime. As the gender focus in epilepsy the later years has primarily been on women, there certainly is a lack of studies focused on the effects particular to men. The present study was aimed to investigate its effects on germ cell's by employing the sperm morphology assay. Twelve groups of male wistar rats were treated with sterile water 0.5 ml, cyclophosphamide (CP) 20 mg/kg, carbamazepine 9, 18, 36 mg/kg (i.p) and 2% gumacasia 0.25 ml/100 g respectively for 5 consecutive days at intervals of 24 hrs. Following the last exposure, on days 14 and 35 sperm morphology assay was conducted as per the standard procedure. Mann-Whitney 'U' test was used for statistical analysis and the level of significance was P<0.01. Neither carbamazepine nor cyclophosphamide induced formation of abnormally shaped sperms at 14 day time interval. Whereas on day 35, with 18 mg/kg dose level of carbamazepine there was an increase in the number of sperms with heads defects (P<0.01); Whereas in the other two dose levels the number of abnormally shaped sperms had decreased. 2% gumacasia increased the number of sperms with tail defects at day 35. (Mann-Whitney 'U' test).

CONCLUSION

Carbamazepine and 2% gumacasia could be germ cell mutagens and could cause infertility on prolonged use therefore further studies with serum drug level estimations are needed.

The effect of carbamazepine on sperm counts in Wistar rats--reflecting upon its mitogenic potential

The present study was aimed to investigate the effects of carbamazepine, an antiepileptic drug, on sperm count in rats. Male Wistar rats were treated with carbamazepine at doses of 9, 18, and 36 mg/kg for five consecutive days. Following the last exposure, on days 14 and 35, spermatozoa were collected from epididymis and counted. On day 14, carbamazepine treatment decreased the sperm number in a dose dependent pattern. On day 35, 9 mg/kg and 36 mg/kg of carbamazepine increased the sperm number in comparison with untreated rats. The results of the study suggest that carbamazepine is a germ cell mitogen.

Circulus arteriosus cerebri: a study of variation in the fetal and adult human brains of south Indians

The Circle of Willis or Circulus Arteriosus Cerebri and its branches are subject to many variations. The Circle of Willis with a classical description is very rare. The constituent arteries forming the circle vary greatly in size in different individuals and on two sides in the same subject. Study by dissection or by angiographic methods by several workers has shown that deviations from the normal pattern occur in a very high proportion of cases. There are differing views regarding the variations in the circle. Thus, this study was done to compare our findings with the others. In the present study, each artery taking part in the circle has been described in relation to the length, size and its origin separately and the findings have been compared.

Incidence, types and clinical implications of a non-metrical variant--mylohyoid bridging in human mandibles

Mylohyoid bridging (MB) is a non-metrical variant of the human mandible. The incidence and types of MB were investigated in 264 mandibles (edentulous 116, semi-dentulous 90 and dentulous 58). No mandible showed a complete type of MB, although 19 (7.2%) mandibles had a partial type. These were classified into two subtypes: distal partial (DP; Type I) and proximal partial (PP; Type II), depending on their location over the mylohyoid groove. The MB was present unilaterally in 7.76% of edentulous mandibles: right side 5.17% (3.45% PP type and 1.72% DP type) and left side 2.59% (1.72% PP type and 0.86% DP type). Of the semi-dentulous mandibles 3.33% had DP type of MB, 1.11% on the right side and 2.22% on the left side, and of the dentulous mandibles 1.72% had DP type of MB on the right side. A total of 13 mandibles out of 264 (4.92%) had unilateral MB. No dentulous mandible had bilateral MB, but 3.45% of edentulous and 2.22% of semi-dentulous mandibles did have. In total, 6 mandibles out of 264 bones (2.27%) had bilateral MB. Of the bilateral incidences 1.72% of edentulous mandibles had a DP-DP combination and the remaining 1.72% had a PP-DP combination. However, both instances of bilateral MB in semi-dentulous mandibles were of PP-DP combination. The incidence or types of MB showed no statistically significant differences between the groups or sides (p > 0.5; chi(2) test). In conclusion, the complete type of MB is a rare occurrence. The incidence increases with age, as edentulous mandibles had a higher incidence of MB than the other two groups. Clinically, MB may compress the mylohyoid neurovascular bundle, leading to neurological or vascular disorders.

A broad-spectrum organophosphate pesticide O,O-dimethyl O-4-nitrophenyl phosphorothioate (methyl parathion) adversely affects the structure and function of male accessory reproductive organs in the rat

Methyl parathion (MP) is an organophosphate pesticide used in agriculture, but also illegally used to spray homes and businesses to control insects. The present study was designed to investigate adverse effects of MP on accessory reproductive organs. Male Wistar rats aged 13-14 weeks were treated and sacrificed as follows. Experiment 1: 0.0 (water vehicle), 1.75, 3.5 or 7mg/kg (i.p.) for 5 days and sacrificed on day 14; experiment 2: 0.0, 0.5 or 1mg/kg (i.p.) for 12 days and sacrificed on day 130; experiment 3: 0.0, 0.5 or 1mg/kg (i.p.) for 12 days and sacrificed on day 77; experiment 4: 0.0, 0.75 or 1.5mg/kg (i.p.) for 25 days and sacrificed on day 17 and experiment 5: 0.0 or 3.5mg/kg (p.o.) for 25 days and sacrificed on day 17, after the last exposure. The accessory reproductive organs were removed, weighed and processed for histopathological analysis. Structural qualitative changes such as epithelial cell morphology and luminal observations were carried out for each organ in all experiments. Epididymis of one side was homogenized and biochemical estimations of acid phosphatase (ACP), cholesterol, total protein, uric acid, and Vitamin C were conducted by calorimetric methods in experiments 4 and 5. In experiment 1 the organ weights did not change; in experiment 2, the epididymal weight increased (P<0.001); in experiment 3, the weights of ductus deferens decreased at 1mg/kg and that of seminal vesicle decreased at both dose-levels (P<0.001). In experiments 4 and 5, weights of epididymis and prostate decreased, whereas in experiment 5, weights of ductus deferens and seminal vesicle increased (P<0.05-0.001). The sperm density was normal in control, moderately decreased in experiment 1 at 3.5 and 7mg/kg; in experiment 2 at 1mg/kg, and in experiment 5 at 3.5mg/kg, and severely decreased in experiment 3 at 1mg/kg and in experiment 4 at both dose-levels. The epithelial necrosis and nuclear pyknosis were seen in experiments 1, 3, 4 and 5, whereas nuclear degeneration was seen in experiment 1 and 4 and germ cells in the lumina of epididymis were seen in experiment 4. The nuclear pyknosis in the ductus deferens was seen in all experiments, except at 1.75mg/kg in experiment 1 and at 0.5mg/kg in experiment 3. Brush border disruption in the ductus deferens was seen in experiments 1 and 4; sperms were seen in the lumen in experiment 1 at 7mg/kg, and in experiments 4 and 5. The vacuoles in the epithelium were seen in experiments 1 and 4 and immature germ cells were seen in the lumen in experiment 4. The ACP and Vitamin C levels decreased in experiment 4 at both dose-levels, and in experiment 5 all biochemical parameters tested found decreased (P<0.01-0.001). The present results indicate that MP affects the structure and function of accessory reproductive organs in the rat.

The reproductive toxicity of the organophosphate pesticide 0, 0-dimethyl 0-4-nitrophenyl phosphorothioate (methyl parathion) in the male rat

Methyl parathion (MP) is a pesticide widely used to protect crops but also illegally used in many countries for spraying homes and businesses to contain insects. The present study was planned to investigate the effects of MP on the male reproductive organs in the rat. Male Wistar rats (13-14 weeks old) were treated with MP and sacrificed as follows. Experiment 1:0 (water vehicle), 1.75, 3.5 or 7 mg/kg (i.p.) for 5 days and sacrificed on day 14; experiment 2:0, 0.5 or 1 mg/kg (i.p.) for 12 days and sacrificed on day 130; experiment 3: 0, 0.5 or 1 mg/kg (i.p.) for 12 days and sacrificed on day 77; experiment 4: 0, 0.75 or 1.5 mg/kg (i.p.) for 25 days and sacrificed on day 17; experiment 5: 0 or 3.5 mg/kg (p.o.) for 25 days and sacrificed on day 17 after the last exposure. The reproductive organs were removed, weighed and processed for histopathological analysis. Structural changes, for example the morphology of the epithelium and the lumina of the organs, were observed in all animals. Biochemical estimates of acid phosphatase (ACP), cholesterol, total protein, uric acid, and vitamin C were conducted in the epididymes. The weight of the epididymes increased in experiment 2 in a dose-dependent pattern (p < 0.01) and decreased in experiments 4 and 5 (p < 0.01). The weight of the ductus deferens decreased in experiment 3 at 1 mg/kg dose level (p < 0.001) and increased in experiment 5 (p < 0.05). The weight of the seminal vesicle decreased in experiment 3 at both 0.5 mg/kg and 1 mg/kg dose levels (p < 0.001), and increased in experiment 5 (p < 0.01). The weight of the prostate decreased in experiments 4 (in a dose-dependent pattern) and 5 (p < 0.001). ACP levels decreased in experiment 4 (p < 0.001) with a greater effect at 0.5 mg/kg than at 1 mg/kg. In experiment 5 (p < 0.01) cholesterol levels decreased to less than 50% of the control level for this experiment (p < 0.01) and protein levels also decreased (p < 0.01). Vitamin C levels decreased in a dose-dependent pattern in experiments 4 (p < 0.001) and 5 (p < 0.01). There were no effects on uric acid level. Sperm density was decreased in the epididymes of the rats treated and the epithelium of the epididymis and ductus deferens showed cellular necrosis, brush-border disruption and nuclear pyknosis. Nuclei were haloed, except in experiment 2 and the 0.5 mg/kg group of experiment 3. Methyl parathion did not induce significant changes in the structure of the seminal vesicle and prostate, except that epithelial folding was shorter than in the control. In conclusion, MP is a reproductive toxicant in the male rat and causes deterioration in the structural integrity of the reproductive organs and also the biochemical parameters in the epididymis.

Studies on the luteolytic, oestrogenic and follicle-stimulating hormone like activity of plant Rhaphidophora pertusa (Roxb.)

The phytochemical, pharmacological and toxicological feature of plant Rhaphidophora pertusa (Roxb.) was done. Phytosteroids, flavonoids, tannins and glucosides were detected in the plant extracts. In cross-bred (Zebu X Holstein-Friesian or Jersey) dairy cows, subsequent to prostaglandin (PG) induced oestrus, to each group (n=4), cloprostenol (PG control) 100 microg i.m. on day 10, the rice gruel (vehicle) was fed on day 10 or the fresh stem (1 kg/animal/day) in rice gruel on day 9, or days 9 and 10, or days 9-11 of the oestrous cycle. Each group received subcutaneously either 5% gum acacia suspension or the plant ethyl acetate or methanol extract (1g in gum acacia) on days 8 (to bannur ewes) or 10 (to dairy cows) of the oestrous cycle. In PG control cows or ewes, there was induction of oestrus in 48 h and a fall in serum progesterone concentration. The feeding of fresh stem in the rice gruel or the s.c. administration of the plant extract did not induce oestrus or significantly (P>0.05) alter the serum progesterone, bilirubin, calcium, creatinine, phosphorus, magnesium and glucose concentrations or the total erythrocyte and leucocyte count, differential leucocyte count and haemoglobin concentration. The plant did not cause any toxicity in the cow or ewe. In immature rats, the aqueous or methanol (hot or cold) extract did not cause any follicle-stimulating hormone (FSH)-like activity. The methanol extract increased the uterine weight in ovariectomised rats. This suggested the presence of oestrogenic activity in the plant. In conclusion, the present study revealed the presence of oestrogenic activity in the plant and the absence of luteolytic or FSH-like or toxic activity.

Toxicity studies of Calycopteris floribunda Lam. in calf, rabbit and rat

The toxicological evaluation of the plant Calycopteris floribunda Lam. was done in calf, rabbit and rat. The phytochemical screening revealed the presence of flavonoids, alkaloids, tannins and saponins. Morbidity and mortality was observed in methanol extract-treated rats and rabbits. In rabbits (25 g/kg/day) and calves (35 g/kg/day) fed fresh leaves showed morbidity and mortality with premonitory clinical signs like depression, downer status, polyuria and characteristic forelimb paresis (seen only in rabbits). The serum urea, alanine-amino transferase, glucose and total cholesterol concentrations were significantly (P<0.05) increased compared to control values. Necropsy of calves revealed the congestion of liver, lung and petechiae on epicardium. The present study indicated the toxic nature of the plant in calf, rabbit and rat.

Dacarbazine induces genotoxic and cytotoxic germ cell damage with concomitant decrease in testosterone and increase in lactate dehydrogenase concentration in the testis

Treatment of cancers with cytotoxic agents such as alkylating drugs often, but not always results in transient to permanent testicular dysfunction. The present study was planned to investigate the effects of dacarbazine [5-(3,3-dimethyltriazeno) imidazole-4-carboxamide] on testicular function in mice. Swiss albino mice (9-12 weeks old) were treated with 0, 5, 25, 50, or 100mg/kg body weight/day dacarbazine (i.p.) for 5 days at intervals of 24h between treatments. Mice were sacrificed on days 7, 14, 21, 28, 35, 49, and 70 after the last treatment (6 mice/dose/sample time), and the epididymal sperm count, sperm motility, sperm morphology, testicular histopathology (qualitative histopathology, seminiferous tubular diameter and epithelial height), and intra-testicular levels of testosterone and lactate dehydrogenase were assessed. Dacarbazine decreased the body weight only on day 28 at 25mg/kg dose-level, but increased the paired testes weights at 50mg/kg on day 7, at 25-100mg/kg on day 14, and at 25 and 50mg/kg on day 21 (P<0.05-0.01; one-way ANOVA and Bonferroni's post hoc test). The sperm count was decreased on all sampling days except at 5 and 25mg/kg dose-levels on day 70, but with severe oligospermia on days 28 and 35 (P<0.05-0.001). The sperm motility was decreased at 100mg/kg on days 14 and 21, at 5, 25, and 100mg/kg on day 28, and at all dose-levels on day 35 (P<0.05-0.001). Dacarbazine induced both head and tail abnormalities and some sperms with cytoplasmic droplets, but significant increase was seen in all dose groups on days 14 and 21, and at 100mg/kg dose-level on day 35. Drug-induced epithelial sloughing was seen on days 14-35 and other histopathological changes observed were vacuoles and abnormal cells. The STD was increased at 25-100mg/kg on day 7, at all dose-levels on day 14, at 50-100mg/kg on days 21 and 28, but without any effects on days 35-70 (P<0.05-0.001), and the tubular lumen was found dilated. The SE was increased on days 7, 21 and 28 at 100mg/kg and on day 14 at 50-100mg/kg. Dacarbazine reduced the intra-testicular testosterone level at 100mg/kg on day 7, at 5, 50 and 100mg/kg on day 14, at all dose-levels on days 21, 28, and 35, and at 50mg/kg on day 49 (P<0.05-0.001). The intra-testicular lactate dehydrogenase concentration increased at all dose-levels up to day 35, but without any effect on days 49 and 70 (P<0.05-0.001). There was no particular dose-response of dacarbazine on any parameters tested. The sperm count (except on day 7-positive correlation; Pearson product moment correlation) or sperm motility did not have any relation but increase in abnormal sperms showed negative correlation with decrease in testosterone level on days 7, 21 and 28. Decrease in sperm count was in negative correlation on days 14 and 35, and increase in abnormal sperms showed positive correlation on day 35 with increase in LDH level. Finally, the decrease in sperm motility had no correlation with increase in abnormal sperm shapes. We conclude that dacarbazine is genotoxic and cytotoxic to the mouse testis in a transient fashion, and these effects are exerted along with decrease in testosterone and increase in lactate dehydrogenase levels in the testis.

Dermal exposure to the herbicide-paraquat results in genotoxic and cytotoxic damage to germ cells in the male rat

The effects of exposure to low doses of paraquat, a herbicide, via the dermal route were studied on the spermatozoa of Sprague-Dawley rats. Paraquat (1, 1'-dimethyl-4, 4'-bipyridinium dichloride) was administered once a day for five days, at intervals of 24 h at 0, 6, 15 and 30 mg/kg, and the rats were sacrificed on days 7, 14, 28, and 42 after the last exposure. The sperm suspensions were obtained by mincing the caudae epididymes and ductus deferens for the purpose of performing a sperm morphology test, sperm count and analysis of sperm mortality and sperm motility, as per the standard procedures. The sperm count was decreased (p < 0.05) only on days 7 and 14 but sperm abnormalities increased on all days (p < 0.05). Sperm mortality increased at higher dose-levels (p < 0.05) except on day 42, and motility was affected by 30 mg/kg only on day 42. In conclusion, paraquat is a genotoxic and cytotoxic agent to germ cells in the male rat.

Neonatal methyl parathion exposure affects the growth and functions of the male reproductive system in the adult rat

Methyl parathion (MP) is a well-known organophosphorus pesticide, to which humans are exposed in fruit and vegetables as residues of 0-2 mg/kg, children being at higher risk of exposure. The present study was planned to investigate the effects on the adult male reproductive functions of MP following neonatal exposure. New born male Wistar rat pups were treated orally with either 0 or 0.5 mg/kg MP from postnatal day (PND) 3 to PND 28 and sacrificed on PND 98 for the purpose of examination of the reproductive system. Methyl parathion lowered the body weights from days 10 to 24 (p < 0.01), the weights of the reproductive organs (p < 0.05-0.01), the epididymal sperm count (p < 0.01) and the homogenisation-resistant testicular spermatid head count (p < 0.01) and also decreased acid phosphatase (ACP), cholesterol, uric acid, protein, ascorbic acid, and lactate dehydrogenase (p < 0.01) levels in the testis but only ACP and cholesterol in the epididymis. The levels of abnormal sperm and testosterone in the testis were increased (p < 0.01), whereas the leutinising hormone level and total number of seminiferous tubules decreased in the testes of treated rats (p < 0.01). A few tubules showed exfoliation of epithelium and vacuoles. The incidence of stage XIV tubules and ratios of meiotic figures and elongating spermatids to Sertoli cell nucleoli decreased (p < 0.01; Mann-Whitney U test). The present results indicate that MP acts as an endocrine disruptor and consequently affects the postnatal development and growth of the male reproductive organs in the rat. These findings are important to the general public, as there is a chance of children being exposed to this pesticide.

Effects of methyl parathion (o,o-dimethyl o-4-nitrophenyl phosphorothioate) on rat sperm morphology and sperm count, but not fertility, are associated with decreased ascorbic acid level in the testis

Methyl parathion (MP; o,o-dimethyl o-4-nitrophenyl phosphorothioate) is an organophosphorous pesticide used world wide to spray agricultural crops. The present study was aimed to investigate the genotoxic and cytotoxic effects on male germ cells and their possible relation with testicular ascorbic acid levels. Adult male Wistar rats (n=5/group) received MP at 0, 0.5, or 1 mg/kg (experiments 1 and 2) for 12 days and 0, 0.75 or 1.5 mg/kg (experiment 3) for 25 days (i.p.) everyday at intervals of 24 h. The epididymal sperm count, sperm abnormalities and testicular ascorbic acid levels (by 2,4-dinitrophenyl hydrazine method) were estimated on days 130, 77 and 17 following the last exposure in experiments 1, 2, and 3, respectively. Virgin untreated female rats were mated with treated males from experiments 2 and 3 for a week effective from day 35 to 41 after the first treatment, and fertility indices were measured after the birth of pups. Sperm count was decreased in experiments 2 and 3 (P<0.01), and in all three experiments, the abnormal sperms increased (P<0.001). Concomitantly, the ascorbic acid levels decreased in the testis (P<0.05-0.001; one-way ANOVA and Bonferroni's post hoc test). The body weights of offspring of treated males did not show significant changes from those of the controls, although there were some decreases observed. MP reduced the lactation index in experiment 2 (P<0.001; Chi-square test). The number of pups/parent along with fertility indices showed some numerical decrease but without any statistical significance. The present findings suggest that MP is a weak genotoxic and cytotoxic agent in the rat exposed to human exposure dose-levels, and that these effects, except the fertility are well correlated with decreased ascorbic acid level in the testis. Furthermore, MP-induced changes in the germ cells do not have any significant effects on F1 generation.

L-ascorbic acid ameliorates postnatal endosulfan induced testicular damage in rats

The aim of the present study is to investigate the effect of L-ascorbic acid on postnatal exposure of endosulfan induced testis damage in the rat. Four groups of seven day old male Wistar rats were treated with 3, 6, 9 and 12 mg/kg endosulfan orally (10 pups/group), from postnatal day 7 to 60 at intervals of 24 h. For 2 more groups (n = 10/group), endosulfan (9 mg/kg and 12 mg/kg) was administered along with L-ascorbic acid (20 mg/kg). The sperm morphology, sperm count and sperm motility was analyzed in all the groups on postnatal day 70. Endosulfan significantly affected the testicular function enhancing the incidence of abnormal spermatozoa, decreasing the sperm count and sperm motility in a dose dependent manner. Abnormalities were of both head and tail and increase in their frequency was more than two-fold of the control value. Sperm count abruptly decreased in 12 mg/kg group and sperm motility decreased up to 50% of the control value. L-ascorbic acid has nullified the toxic effects of the pesticide significantly, but not to the control level. Endosulfan induces the testicular damage following postnatal exposure and L-ascorbic acid prevents the adverse effects considerably in the rat.

The antiviral drug ribavirin reversibly affects the reproductive parameters in the male Wistar rat

The present study was planned to evaluate the toxic effects of ribavirin on the reproductive parameters in the male Wistar rat. Rats (11--13 weeks old) were treated with 5 injections (i.p.) of 20, 100 or 200 mg/kg/day ribavirin at intervals of 24 h. The testes were processed for histopathological analysis on days 14, 35, 70 and 105 after the last exposure. The parameters studied were body weight, the weights of the testis, epididymis, seminal vesicle and prostate, seminiferous tubular diameter (STD), epithelial height (SE), epithelial sloughing, incidence of stage XIV tubules, sperm abnormality and total serum level of testosterone. Data were analysed by ANOVA and the Bonferroni post hoc test for significances between different groups. There was a decrease in body weight and organ weights, excluding those of the testis and epididymis, against control at higher dose-levels. Ribavirin induced the formation of vacuoles, gaps and sloughing of the seminiferous epithelium. The STD, SE and the incidences of stage XIV tubules decreased on days 14 and 35. Ribavirin also induced the formation of sperm with microcephaly and cephalocaudal junction defects, with or without fibrils jetting out. All these morphological defects recovered to control limit by day 105. The serum level of testosterone was decreased at all dose-levels and time points, although recovery had started by day 105. In conclusion, ribavirin is gonadotoxic in male rats but the effects are reversible after a period of 105 days. However, the endocrine-disrupting properties of ribavirin persist beyond this period.

Effect of extracts of Murraya koenigii leaves on the levels of blood glucose and plasma insulin in alloxan-induced diabetic rats

The effect of daily oral administration of aqueous extract (600 mg/kg b.wt.) and methanol extract (200 mg/kg b.wt.) of Murraya koenigii Spreng leaves for a period of eight weeks was studied on blood glucose and plasma insulin level in alloxan-induced diabetic rats. Blood glucose levels of diabetic rats treated with aqueous and methanol extracts of Murraya koenigii Spreng showed significant reduction (P<0.05) as compared to diabetic control groups. Plasma insulin showed significantly high on 43rd and 58th days of treatment in aqueous and methanol extracts of Murraya koenigii treated groups. This suggests that the hypoglycemic effect may be mediated through stimulating insulin synthesis and/or secretion from the beta cells of pancreatic islets of Langerhans.

Intraosseous course of the inferior alveolar (dental) nerve and its relative position in the mandible

The present study was planned to evaluate the position of the mandibular foramen (MF) and the course of the inferior alveolar nerve in 12 right and 14 left cadaveric hemimandibles. The soft tissue including the muscle attachments of the mandible was cleaned and the inferior neurovascular bundle was dissected up to the MF. The distances from the MF to the angle, symphysis menti, 3rd molar, and the lower point of the mandibular notch were measured. The bone was chiseled from its lingual surface to expose the mandibular canal. The distances from the nerve to the alveolar and inferior borders were measured. The distance from the MF to different landmarks did not show any side differences except the one to the symphysis menti (P<0.05; Mann-Whitney 'U' test). Similarly the distances from the nerve to the borders also did not show any significant side differences. These data indicate that, on average, MF is located at a symmetrical point on the ramus on either side, although, not exactly at a fixed distance from any landmarks tested. Further, the canals were located either at near to the middle or below near to the base of the mandible. This study concludes that, the location of the MF varies from bone to bone despite its bilateral symmetry. Further, the canal and consequently the nerve do not maintain a constant position in the mandible.

The genotoxic and cytotoxic effects of ribavirin in rat bone marrow

The genotoxic and cytotoxic effects of the antiviral drug, ribavirin, was studied in rat bone marrow by employing the micronucleus assay. Ribavirin in doses of 10, 15, 20, 30, 50, 75, 100 and 200 mg/kg, and cyclophosphamide (CP) 40 mg/kg (only for sex-difference study) were injected intraperitoneally. Bone marrow was collected at 24 h and 48 h following the injection. To evaluate the recovery, the bone marrow was also sampled at 72 h from 20, 100 and 200 mg/kg treated rats. The micronucleus assay was conducted according to the standard procedure. Ribavirin elevated the incidence of micronuclei (except 10 mg/kg) in erythrocytes (P<0.01). The micronucleated polychromatic erythrocytes showed the initial steep increase at 15 and 20 mg/kg dose level, then with the gradual increase, possibly due to the limited metabolism and action of higher doses. The incidence of micronucleated normochromatic erythrocytes was not dose dependent. The effect was more at 48 h than 24 h due to prolonged toxicity of the drug or its metabolites, and by 72 h, recovery was observed even though the genotoxicity was significant. The PCE% decreased as the dose was increased up to 75 mg/kg, then without much difference between two higher doses. Only 100 mg/kg ribavirin and CP showed more toxicity on male rats. Cytotoxicity was seen due to hindered erythropoiesis or cell destruction. Our findings suggest that ribavirin is genotoxic and cytotoxic agent for rat bone marrow.

Mechanism of cytotoxicity of ribavirin in the rat bone marrow and testis

Mechanisms of cytotoxicity of an antiviral drug, ribavirin was studied in the rat bone marrow and testis. Ribavirin at the dose levels of 20, 100 and 200 mg/kg was treated (i.p.) either as single (for bone marrow) or 5 (for testis) treatments. Bone marrow smears were obtained at 24, 48 and 72 h following the exposure and stained with the May-Gruenwald-Giemsa combination. Smears were screened for the incidence of dead cells, and at 24 h, a total of 2000 erythrocytes were counted to obtain the ratio of polychromatic erythrocytes (PCEs) to normochromatic erythrocytes (NCEs) (P/N). Step 19 spermatids/stage VII tubule, dividing cells (meiotic figures)/stage XIV tubule and the incidence of tubules with dead cells were counted in periodic acid--Schiff's reaction and haematoxylin (PAS-H) stained testicular sections on days 14, 35, 70 and 105. Significant decrease in the step 19 spermatids and meiotic figures, and increase in the incidence of tubules with dead cells (P < 0.05-0.01) were observed mainly on days 14 and 35. The cell death was observed in the bone marrow mainly at the two higher dose levels and significant decrease (P < 0.001) in P/N ratio was observed. This present study concludes that the cytotoxicity of ribavirin in these two target cell-lines in due to the induction of cell death and prevention of the cell division.

Ribavirin-induced sperm shape abnormalities in Wistar rat

Ribavirin (1-beta-D-ribofuranosyl-1,2,4, triazole-3 carboxamide) is a broad-spectrum antiviral drug. This study was aimed to investigate the mutagenicity of ribavirin on germ cells by employing sperm morphology assay. Male Wistar rats were treated with water, cyclophosphamide (CP) 40 mg/kg, and ribavirin 20, 100 and 200 mg/kg (i.p.) for 5 consecutive days at intervals of 24h. Following the last exposure, at 14, 28, 35, 42 and 70 days, the epididymal sperm smears were obtained and stained according to the standard procedure. One thousand sperms per animal were classified into normal and different abnormal types. Both CP and ribavirin-induced anomalies of head and tail of sperm except at 70 days. In CP groups, maximum incidence was observed at 28, 35 and 42 days. Ribavirin 20 mg/kg induced maximum incidence at 14 and 42 days, 100 mg/kg at 28 and 42 days and 200 mg/kg at 28-42 days. These results show that ribavirin is mutagenic to rat germ cells in a transient fashion.

Effect of ribavirin on epididymal sperm count in rat

Ribavirin (1-beta-D-ribofuranosyl-1, 2, 4-triazole-3-Carboxamide) is a potent inhibitor of inosine monophosphate dehydrogenase, used widely as an antiviral drug. Although it has been reported as a teratogen, its effect on spermatogenesis is not known. Male Wistar rats were segregated into 24 groups of 5 in each. Six groups were treated with water, 6 groups with 20 mg/kg, another 6 groups with 100 mg/kg and remaining 6 groups with 200 mg/kg for 5 days at intervals of 24 h (i.p.). Animals were anaesthetized at 14, 28, 35, 42, 70 and 105 days following the last exposure, laparatomy was conducted, epididymis was removed, minced in 1 ml phosphate buffered saline (PBS, pH 7.2), filtered and stained with 1% aqueous eosin Y. An aliquot was taken in haemocytometer, diluted in PBS and charged into Neubauer's chamber. Spermatozoa were counted in 8 squares except the central, and multiplied by 5 x 10(4). Data were analysed by Mann-Whitney "U" test. Ribavirin significantly decreased the sperm count in a dose and time dependent pattern and showed a recovery by day 105 except at 200 mg/kg. Ribavirin is reversibly cytotoxic to germ cells and decreases the production of spermatozoa.

Effect of ciprofloxacin on specific immune response in rabbits

Ciprofloxacin (10 mg/kg body weight, iv, twice daily for 4 days) failed to alter specific antibody titres, total immunoglobulin concentration, total serum protein concentration, total leukocyte count, lymphocyte percentage, phagocytic index and skin thickness in DNCB skin sensitivity test against Brucella plain killed antigen in New Zealand White rabbits. It can be concluded that ciprofloxacin at the dose and duration employed did not adversely affect specific immune response in normal rabbits.

Induction of seminiferous tubular atrophy by single dose of 5-fluorouracil (5-FU) in Wistar rats

Antimetabolite, 5-fluorouracil (5-FU) is known to cause testicular damage by epithelial sloughing and cell killing. However, it is not known whether 5-FU induces tubular atrophy and the fate of exfoliated germ cells. Present study was conducted to evaluate these effects of 5-FU on rat testis. Animals were injected, single dose of 5-FU (10.50 & 100 mg/kg, i.p.) and sampled at 1, 3, 15 and 30 day following the treatment. The testes were perfusion fixed by Bouin's fluid. Five micron thick paraffin sections of testes and epididymis were stained with haematoxylin and eosin. Slides were examined for the incidence of abnormal tubules (per 200 tubules), tubular diameter (STD), epithelial height (SEH) and for the presence of germ cells in the epididymis. Data were analysed by Mann-Whitney 'U' test. The testes weight, STD, SEH were decreased (P < 0.05-0.01) in treated animals. The abnormal tubules were increased in a dose dependent manner with atrophic tubules seen on 30 d. The exfoliated germ cells have not blocked the post testicular ductal system and found in the epididymis in a dose dependent manner. The present study concludes that 5-FU causes tubular shrinkage and atrophy. Further, epididymis is involved in the phagocytosis of germ cells.

5-fluorouracil (5-FU) induces the formation of giant cells and sloughing of seminiferous epithelium in the rat testis

The chemotherapeutic agent, 5-fluorouracil (5-FU) has been widely used in the treatment of a variety of cancers. Its effect on the testis has not been substantially studied. Present study was conducted to evaluate the gonadotoxicity of 5-FU in male albino rats. Animals were injected with single dose of 5-FU (10, 50 and 100 mg/kg, i.p.) and sampled on 1, 3, 15 and 30 day post exposure. Animals were anaesthetised, testes were perfusion fixed by Bouin's fluid. Five micron thick paraffin sections were stained with haematoxylin and eosin. Slides were screened for the incidence of partially and extensively sloughed tubules. Data were analysed by Mann Whitney 'U' test. Only 100 mg/kg induced multinucleated cells on 3rd day. All doses of 5-FU induced sloughing of the seminiferous epithelium. Maximum number of partially sloughed tubules were seen on third day. Partial sloughing was not dose dependent except on 15th day. The extensive sloughing was dose dependent except on 30th day. The result indicates that all the doses of 5-FU tested in this study cause sloughing of epithelium and only 100 mg/kg induces the formation of giant cells on third day.

The effect of malathion, an organophosphate, on the plasma FSH, 17 beta-estradiol and progesterone concentrations and acetylcholinesterase activity and conception in dairy cattle

The effect of malathion on jugular plasma concentrations of follicle-stimulating hormone (FSH), estradiol (E2), progesterone (P4) and acetylcholinesterase (AchE) on conception in dairy cattle during a cloprostenol (prostaglandin F2 alpha analogue, PG)-induced estrus was studied. Malathion (1 mg/kg, intraruminally) given at the onset of estrus (48 h after PG) did not alter the plasma FSH or E2 concentrations but significantly (P less than 0.05) inhibited plasma P4 concentration. The mean P4 concentration in the malathion-treated group on days 8 and 12 were 0.8 +/- 0.4 and 1.0 +/- 0.5 ng/ml, as compared to 2.6 +/- 0.0 and 2.4 +/- 0.3 ng/ml in the control group. There was a nonsignificant (P greater than 0.05) inhibition of plasma AchE activity in malathion-treated cattle. Conception was 16.6% in malathion-treated cows and 50% in controls. Inhibition of progesterone secretion and poor conception occurred after the single intraruminal dose of malathion at the onset of estrus.

Preliminary studies on cholinergic control of pituitary gonadotrophin secretion in the ewe

Administration of neostigmine, a cholinomimetic, to anoestrous ewes diminished the increase in jugular plasma luteinising hormone and follicle-stimulating hormone induced by oestradiol. Intravenous injection of atropine had no effect on the gonadotrophin surge.