A narrative review of toxicity of chemoradiation and immunotherapy for unresectable, locally advanced non-small cell lung cancer

Despite declining smoking rates, lung cancer remains the second most common malignancy in the United States and the leading cause of cancer-related mortality. Non-small cell lung cancer (NSCLC) comprises roughly 85% of cases, and patients tend to present with advanced disease. Historically, concurrent chemoradiotherapy (CRT) has been the standard of care for stage III unresectable NSCLC but outcomes even with multimodal therapy have remained relatively poor. Efforts to improve outcomes through radiation dose escalation with conventional dose fractionation were unsuccessful with RTOG 0617, demonstrating significantly decreased overall survival (OS) with high dose radiation with respect to standard therapy. The recent PACIFIC trial established a new role for consolidative immune checkpoint blockade therapy after CRT using the programmed death ligand 1 (PD-L1) inhibitor durvalumab, by demonstrating significantly improved progression free survival and OS. Although promising, the addition of immunotherapy to multimodal therapy has generated debate regarding the most effective immune pathways to target, appropriate sequencing of therapy, most effective radiation techniques, and toxicity-related concerns. This review will highlight recent and ongoing trials in unresectable, locally advanced NSCLC that incorporate chemotherapy, radiation, and immunotherapy with an emphasis on analysis of treatment-related toxicities and implications for future study design.

Linac-based fractionated stereotactic radiosurgery for high-risk meningioma

PURPOSE

Single-fraction stereotactic radiosurgery(SRS) for meningioma has high rates of symptomatic perilesional edema in some settings. Fractionated stereotactic radiosurgery(fSRS) could decrease edema rates while maintaining tumor control.

METHODS AND MATERIALS

Patients at an institution were retrospectively reviewed(2013-2017). Adults receiving definitive, linear accelerator(linac)-based fSRS (25-30Gy/5 fractions) were included. fSRS was recommended for tumors at high risk for perilesional edema with SRS due to large size, prior irradiation, or proximity to organs at risk. Endpoints included rates of symptomatic, radiographically-defined perilesional edema and local control(LC).

RESULTS

12 Patients with 13 meningiomas met criteria. 24-month actuarial LC and overall survival were 87% and 100%. Symptomatic, post-treatment edema was identified on follow-up MRI in 31% of cases. No variables predicted edema, but affected lesions were larger(6.82 v. 2.46cc).

CONCLUSION

Linac-based fSRS for meningioma has high local control and modest toxicity rates similar to SRS in the literature. Prospective studies comparing fSRS/SRS are warranted.

Hemostatic and fibrinolytic status in patients with ovarian cancer and benign ovarian cysts: could D-dimer and antithrombin III levels be included as prognostic markers for survival outcome?

We determined the hemostatic and fibrinolytic status in 60 patients with ovarian cancer and benign ovarian cysts. Hypercoagulation, increased platelets, and enhanced fibrinolysis were seen in patients with preoperative ovarian cancer compared to patients with benign ovarian cysts. Enhanced thrombin generation, evidenced by increased F1+2 and decreased antithrombin III (ATIII) levels with further enhanced fibrinolysis by elevated D-dimer, was seen in advanced cancer. Ten ovarian cancer patients died within 13 months after diagnosis and another died at 24 months, all from advanced stage of cancer, except one from stage IC cancer who died at 11 months. The survival rates from the disease at 13 months and 24 months were 66.7% and 45%, respectively. Most of the patients had gone through the complete course of chemotherapy, and those patients still alive have been disease free between 13 and 42 months. No statistical relationships for the hemostatic parameters studied in ovarian cancer patients could be found between those who died and those still living 13 and 24 months after diagnosis, except for ATIII and D-dimer levels. Elevated D-dimer levels were associated with those who died within 13 and 24 months from the disease, and the decreased ATIII levels only reached statistical significance by 24 months. It could be suggested that these two parameters might be useful as systemic prognostic markers in survival outcome from the disease for the first 24 months in advanced ovarian cancer, in addition to the known correlation with the International Federation of Gynecology and Obstetrics stage.

Proerectile pharmacological effects of Tribulus terrestris extract on the rabbit corpus cavernosum

INTRODUCTION

The objective of the present study was to investigate the effect of oral treatment of Tribulus terrestris (TT) extract on the isolated corpus cavernosal tissue of New Zealand white (NZW) rabbits and to determine the mechanism by which protodioscin (PTN), a constituent of the TT, exerts its pharmacological effects.

MATERIALS AND METHODS

Twenty-four NZW rabbits were randomly assigned to 4 experimental groups of 6 each. Group I served as control. Groups II to IV were treated with the extract at different dose levels, i.e. 2.5 mg/kg, 5 mg/kg and 10 mg/kg body weight, respectively. The TT extract was administered orally, once daily, for a period of 8 weeks. The rabbits were then sacrificed and their penile tissue isolated to evaluate the responses to both contracting and relaxing pharmacological agents and electrical field stimulation (EFS).

RESULTS

PTN on its own had no effect on the isolated corpus cavernosal strips. The relaxant responses to EFS, acetylcholine and nitroglycerin in noradrenaline precontracted tissues from treated groups showed an increase in relaxation of a concentration dependent nature compared to that of the tissues from control group. However, the contractile, anti-erectile response of corpus cavernosal tissue to noradrenaline and histamine showed no significant change between the treatment and the control groups.

CONCLUSIONS

The relaxant responses to acetylcholine, nitroglycerin and EFS by more than 10%, 24% and 10% respectively compared to their control values and the lack of such effect on the contractile response to noradrenaline and histamine indicate that PTN has a proerectile activity. The enhanced relaxant effect observed is probably due to increase in the release of nitric oxide from the endothelium and nitrergic nerve endings, which may account for its claims as an aphrodisiac. However, further study is needed to clarify the precise mechanism of its action.

Evacuation interval after vaginal misoprostol for preabortion cervical priming: a randomized trial

OBJECTIVE

To determine the optimal interval for evacuation after preabortion cervical priming with vaginal misoprostol.

METHODS

One hundred eighty healthy nulliparas requesting legal termination of pregnancy between 6 and 11 weeks' gestation were assigned randomly to receive 400, 600, or 800 microg of intravaginal misoprostol. Vacuum aspiration was done after 3 hours in the 400-microg group and after 2 hours in the 600- and 800-microg groups. The degree of cervical dilatation before operation was measured with a Hegar dilator. Preoperative and intraoperative blood loss and associated side effects were also assessed.

RESULTS

Eleven (18.3%) and 15 (25.0%) women in the 600-and 800-microg groups, respectively, had cervical dilatation of at least 8 mm after an interval of 2 hours; 55 (91.7%) women who received 400 microg for a 3-hour interval had similar cervical dilatation. Using 400 microg as a baseline, the odds ratio (OR) was 0.02; 95% confidence interval (CI) was 0.01, 0.06 for 600 microg and OR 0.03; 95% CI 0.01, 0.09 for 800 microg for achieving successful preabortion cervical dilatation of at least 8 mm. The mean cervical dilatation of 6.7 mm and 6.8 mm for the higher doses was also significantly less than that of 8.1 for the 400-microg dose (P<.001). The mean preoperative and intraoperative blood loss was only statistically different when the 400- and 800-microg groups were compared (P = .03). There were also significantly more side effects, namely abdominal pain and fever above 38.0 C, in the 600- and 800-microg groups (P<.001), compared with the 400-microg group. When the 600- and 800-microg groups were compared, there were still significantly more women complaining of abdominal pain (P<.001). None of the women in the study required analgesics for pain or antipyretics for fever.

CONCLUSION

The minimal evacuation interval should be at least 3 hours for successful preabortion cervical priming.

Does an acidic medium enhance the efficacy of vaginal misoprostol for pre-abortion cervical priming?

Absorption pharmacokinetics reveal a relationship between plasma concentrations of misoprostol and its therapeutic effect. To achieve a constant plasma profile and optimal efficacy, it is important to develop a medium that ensures complete dissolution of vaginal misoprostol tablets. Vaginal misoprostol is said to liquefy better in an acidic medium; thus, the aim of this study was to determine whether a 200 microg misoprostol tablet dissolved in acetic acid would be more efficacious than 200 microg misoprostol dissolved in water for pre-abortion cervical priming. A total of 120 healthy nulliparous women requesting legal termination of pregnancy between 6-12 weeks gestation were allocated randomly to either of the study groups. Vacuum aspiration was performed 3-4 h after insertion of the misoprostol tablet. Using Hegar's dilator, the degree of cervical dilatation before operation was measured. Of 60 women, 14 (23%) achieved a cervical dilatation of >/=8 mm when the misoprostol dose was dissolved in acetic acid; 12 (20%) achieved a similar cervical dilatation when the dose was dissolved in water. The mean cervical dilatation for the acid and water media used was 6.3 mm and 6.2 mm respectively; these differences were not statistically significant, neither were pre-operative and intra-operative blood losses statistically different between the two groups. Twenty-four (40%) and four (7%) respectively of women in whom a water medium was used experienced vaginal bleeding and abdominal pain; 20 (33%) and 0 women respectively among those in whom an acetic acid medium was used experienced vaginal bleeding and abdominal pain. These differences in side effects were not statistically significant. Our study shows that the use of acetic acid to dissolve vaginal misoprostol does not improve the efficacy in achieving successful cervical dilatation for pre-abortion cervical priming.

Vaginal misoprostol for pre-abortion cervical priming: is there an optimal evacuation time interval?

OBJECTIVE

To determine the optimal evacuation time interval in the use of vaginal misoprostol for cervical priming before first trimester termination of pregnancy.

DESIGN

Prospective double-blind randomised study.

SETTING

Fertility Control Centre, National University Hospital, Singapore.

METHODS

Sixty healthy nulliparous women requesting legal termination of pregnancy between 6 and 11 weeks of gestation were randomly allocated to either the 400 microg or 600 microg misoprostol group. Vacuum aspiration was performed after three hours in the 400 microg group and at the end of two hours in the women given 600 microg misoprostol. Using Hegar's dilator, degree of cervical dilatation before operation was measured. Other parameters assessed included the amount of additional dilatation required (if < Hegar 8), pre-operative and intra-operative blood loss, and associated side effects.

RESULTS

For the 600 microg group, only five women (16.7%) achieved a cervical dilatation of > or = 8 mm, compared with 28 women (93.3%) in the 400 microg group. Using the 400 microg misoprostol group as a baseline, the odds ratio was 0.014 (95% CI 0.003-0.080) for 600 microg for successful pre-operative cervical dilatation of > or = 8 mm. The mean cervical dilatation for 400 and 600 microg misoprostol was 8.1 mm and 6.6 mm, respectively (P < 0.001). Despite the shorter evacuation time interval of two hours, the 600 microg dose was associated with an increase in side effects such as vaginal bleeding, abdominal pain and a fever of > 38.0 degrees C. However, other than abdominal pain, no significant differences in the frequency of these side effects were shown.

CONCLUSION

Use of 400 microg misoprostol with a minimal evacuation time interval of three hours still appears the optimal dosage and evacuation time for cervical priming before first trimester termination of pregnancy.

Effects on hemostasis after two-year use of low dose combined oral contraceptives with gestodene or levonorgestrel

We studied 67 healthy women who were randomly allocated to receive third generation gestodene (Gynera) or second generation levonorgestrel (Microgynon 30) combination of low-dose estrogen oral contraceptives (OCs) for their hemostatic effects over 2 years. Hemostatic changes were apparent within 3 months of OC use. Hematocrit (Hct) was not affected, but hemoglobin (Hb) concentration decreased by 18 months. Shortened prothrombin time (PT) and activated plasma thromboplastin time (APTT) were associated with elevated fibrinogen within the 12-month use of both OCs. Factor VII was reduced only in Micro 30 during the 18 months of use. Enhanced thrombin-antithrombin (TAT)-complex level was seen at 18 months of Gynera use. Prothrombin fragment1+2 (F1+2) rise was seen at 3 months with Micro 30. Reduced antithrombin III (ATIII) activity was seen at 18 months with Gynera and at 24 months with Micro 30. Increased protein C activity was seen at 3 months and reduced protein S occurred at 18 months of Gynera use. Tissue plasminogen activator (t-PA) activity was enhanced for 6 months in both OCs with raised D-dimer levels for 12 months with Gynera and 6 months with Micro 30. Decreased t-PA antigen was seen at 18 months and decreased urokinaselike plasminogen activator (u-PA) antigen occurred throughout the 24 months of both OCs use. Enhanced u-PA activity was only seen in Gynera users. Elevated plasminogen levels were apparent throughout both OCs use. PAI-1 levels were significantly decreased with Micro 30. With Gynera, the decreased PAI-1 activity was seen only at 18 months and PAI-1 antigen at 12 months. No change in platelets and von Willebrand factor (vWF) were seen in long-term OC use except that beta-thromboglobulin (beta-TG) showed decreased trends reaching statistical significance by 18 and 24 months of Micro 30 use and by 24 months of Gynera use. A further significant decrease in beta-TG, u-PA antigen, ATIII, and protein S levels were seen 3 months after pill stoppage compared with pretreatment levels. Activated protein C resistance (APCR) was negative in all subjects before and during OC use. The study indicated dynamic balance between coagulation and fibrinolysis with no endothelial activation. However, because some hemostatic markers showed wide fluctuations during OC use, a longer term study is warranted to investigate any adverse hemostatic changes that might enhance the risks of venous thromboembolism in Asian subjects known to be less prone to thrombosis.

Randomized trial to determine optimal dose of vaginal misoprostol for preabortion cervical priming

OBJECTIVE

To determine the optimal dosage of vaginal misoprostol for cervical priming before vacuum aspiration abortion.

METHODS

One hundred twenty women were assigned randomly to receive 200, 400, 600, or 800 microg of misoprostol given vaginally. Vacuum aspiration was performed 3-4 hours after the insertion of misoprostol tablets. The degree of cervical dilation before operation was measured with a Hegar dilator. Preoperative and intraoperative blood loss and associated side effects also were assessed.

RESULTS

Twenty-nine (96.7%) women in the 400-microg group and all in the 600-microg and 800-microg groups achieved cervical dilation of at least 8 mm. The success rate for the 200-microg group was only 23.3%, significantly less efficacious than the 400-microg dose (odds ratio 95.3; 95% confidence interval 10.9, 830.9; P < .001). There was no significant difference among the 400-, 600-, and 800-microg groups (P = .364) with respect to achieving cervical dilation at least 8 mm. However, 800 microg was associated with significantly more side effects than 600 microg (preoperative and intraoperative blood loss, P < .001; abdominal pain, P = .005; products of conception at os, P < .001; fever higher than 38.0C, P = .002). When 400 microg and 600 microg were compared, we found that the higher dose also was associated with significantly more side effects. The 600-microg group was used twice in the comparison, but all P values remained significant even after the Bonferroni adjustment for multiple comparisons.

CONCLUSION

Vaginal application of 400 microg of misoprostol is the optimal dose for vacuum aspiration preabortion cervical dilation in first-trimester nulliparas.

A comparative study using two dose regimens (200 microg or 400 microg) of vaginal misoprostol for pre-operative cervical dilatation in first trimester nulliparae

OBJECTIVE

To determine the optimal dosage and dosing interval for the use of misoprostol administered vaginally for pre-operative cervical dilatation.

DESIGN

Prospective double-blind randomised study.

SETTING

Fertility Control Centre, National University Hospital, Singapore.

METHODS

Women were randomly allocated to either the 200 microg or the 400 microg misoprostol group. Vacuum aspiration was performed at either three or four hours after the insertion of misoprostol tablets. Using Hegar's dilatator, degree of cervical dilatation before operation was measured. Other parameters assessed included the amount of additional dilatation required (if it was < Hegar 8), pre-operative and intra-operative blood loss, and associated side effects.

RESULTS

For the 200 microg misoprostol group, only seven (23.3%) achieved a dilatation of > or = 8 mm compared with 29 women (96.7%) in the 400 microg misoprostol group. The odds ratio was 95.3 (95% CI 10.9-830.9) for 400 microg misoprostol for successful pre-operative cervical dilatation of > or = 8 mm. The mean cervical dilatation for 400 microg and 200 microg misoprostol was 8.2 mm and 6.4 mm, respectively (P < 0.001). The use of 400 microg misoprostol with an evacuation interval of three hours appears to be the optimal dosage and evacuation time interval. Increasing the time interval beyond three hours did not confer any additional advantage on the rate of successful cervical dilatation but was instead associated with an increase in side effects such as vaginal bleeding, lower abdominal pain and the appearance of products of conception at the cervical os. However, besides vaginal bleeding, no significant differences in the frequency of these side effects were demonstrated.

CONCLUSION

This first report on the comparison of differing dosages and time intervals to determine the optimal dosage treatment schedule shows that the vaginal application of 400 microg misoprostol for at least three hours is optimal for pre-operative cervical dilatation before vacuum aspiration in first trimester nulliparae.

Abortion trends in Singapore: a 25-year review

STUDY OBJECTIVE

Abortion legislation in Singapore has gone through dramatic changes in the past 25 years. In this paper, we studied the effect of abortion legislation on abortion trends in Singapore.

SETTING AND PARTICIPANTS

The Ministry of Health, Singapore, collects data on all abortions performed in Singapore. These data have been analyzed and are presented in this paper.

RESULTS

The liberalization of abortion legislation resulted in a dramatic increase in the number of abortions performed beginning in 1974. The rate peaked at 23,512 abortions in 1985, and in fact, 35% of all pregnancies were terminated in 1985. The introduction of mandatory abortion counseling in 1986 resulted in a decline in the number of abortions to 16,476 in 1993 with only 24.6% of pregnancies being terminated. The teenage abortion rate was 0.2 per 1000 female teenagers under 20 years of age in 1970. With the liberalization of abortions, the rate reached a peak of 13.7 per 1000 female teenagers in 1985. In 1993, the teenage abortion rate was 9.5%. The proportion of nulliparous women seeking abortion has increased phenomenally from 0.5% in 1976 to 40.6% in 1993. Close to 95% of the women seeking abortions in 1993 did so for social reasons, 3.7% for medical reasons, and 2.0% for failed contraception (Table 3).

CONCLUSION

Mandatory abortion counseling and a change in the government policy which now encourages Singaporeans to have more children if they can afford it, have resulted in a decrease in the number of abortions being performed. The problems of teenage abortions, nulliparous abortions, and repeated abortions need to be further addressed.

Termination of early human pregnancy with either 50 mg or 200 mg single oral dose of mifepristone (RU486) in combination with either 0.5 mg or 1.0 mg vaginal gemeprost

Mifepristone (RU486) is licensed for use in France at a dose of 600 mg in combination with 1.0 mg of vaginal gemeprost (a prostaglandin E1 analogue) for medical termination of early pregnancy up to 7 weeks' amenorrhoea resulting in 96% complete abortion rates. This study examines if it is possible to use lower doses of mifepristone and gemeprost to achieve similar success for women with pregnancies up to 56 days' amenorrhoea. Four groups of 25 women were scheduled to be given single oral doses of either 50 mg or 200 mg of mifepristone followed 48 hours later by insertion of a single vaginal pessary of 0.5 mg or 1.0 mg gemeprost. The lowest dose combination (i.e. 50 mg mifepristone + 0.5 mg gemeprost) was found to have unacceptable efficacy with a complete abortion rate of only 82%; the highest dose combination (i.e. 200 mg mifepristone + 1.0 mg gemeprost) resulted in a satisfactory complete abortion rate of 96% which is comparable with the rates for the recommended high 600 mg mifepristone dose (+ 1.0 mg gemeprost) in routine clinical use in France. The current study shows that efficacy can be maintained using a third of the recommended dose of mifepristone.

Blood loss in termination of early pregnancy with mifepristone and gemeprost

The combination of an antiprogestogen with prostaglandin has been shown to be an effective alternative to surgical procedures for pregnancy termination in the first 49 days of amenorrhoea and has been available in France since late 1988. Mifepristone when used alone caused poor efficacy with unacceptable vaginal bleeding. The addition of a prostaglandin analogue (sulprostone, gemeprost) produced acceptable efficacy with less bleeding. The present study provides a quantitative assessment of blood loss in a sample of 20 women undergoing medical termination of early pregnancy (amenorrhoea < or = 49 days). Vaginal bleeding occurred between days 3 and 15 of commencing therapy. The median number of days of bleeding was 4 with a median blood loss of 91.5 mL. The mean blood loss was 136.8 mL (+/- SD 159.2) but this did not adversely affect the hemoglobin level in the volunteers. Most patients describe the experience as that similar to a heavy period and viewed the procedure positively especially since they are spared the anaesthetic risks and hospitalization attendant with surgical abortion. Caution is still however advised as there may be the occasional subject with excessive haemorrhage (as in this study where one woman bled a total of 761.4 mL) and close supervision by a physician is essential.

The feasibility of early second trimester pregnancy (12 to 14 weeks) termination with single intra-amniotic injection of 15-methyl PGF2 alpha

Prostaglandin analogues have proven to be safe and effective for second trimester pregnancy terminations when given by various routes. Of these, the intra-amniotic (IA) route has proven to be safer, especially in women with medical disorders, as it causes the least occurrence of systemic side-effects. Previously, blind transabdominal IA instillation of the analogue 15-methyl PGF2 alpha was routinely possible only after 16 weeks' gestation. With the advent of ultrasound-guided techniques, it has now become possible to use the IA route for very early second trimester pregnancies. This study examines the use of single 1.5 mg 15-methyl PGF2 alpha IA injection for termination of 12-14 weeks pregnancies. Single injection resulted in successful abortion in 76.5% of women and, in the unsuccessful cases, additional prostaglandin injection resulted in successful abortion in all women within 48 hours without problems. It is therefore feasible to use ultrasound-guided IA prostaglandin injection for successful termination of early second trimester pregnancies.

Prevalence of intestinal parasites in rural areas of district Shahjahanpur, Uttar Pradesh

A stool survey was carried out in some of the villages of Dadraul and Bhawal Khera PHC's of district Shahjahanpur (Uttar Pradesh). Out of 381 individuals examined 111 (29.2 per cent) were found positive for one or the other intestinal parasite. Ascaris lumbricoides superseded all the parasites by showing a positivity of 17.85 percent. Other parasites found were Hookworm, Hymenolepis nana, Tapeworm, Trichuris trichiura, Enterobius vermicularis, Entamoeba histolytica, E. coli and Giardia lamblia. Parasitic load was slightly higher in females (33.59 per cent) than males (28.18 per cent). The highest positivity was encountered in the age groups between 6 to 14 years. This high prevalence of intestinal parasites may be due to the lack of awareness about personal cleanliness and hygiene and illiteracy among rural women. Majority of them had helminthic infections. It is concluded that in rural areas of district Shahjahanpur intestinal helminthic infections are more prevalent that protozoan infections.

'Pregnancy tumour' of the nasal septum

The origins of pyogenic granulomas are subject to much debate. It is viewed as overexuberant growth of epithelium and capillary loops (i.e. granulation tissue) in response to trauma by some authorities, and is considered a capillary haemangioma with a unique lobular organization by others. Although the pathogenesis of the lesion is unclear, marked variation in sexual distribution suggests a hormonal factor, and the profound metabolic and endocrine changes in pregnancy seem to provide especially fertile soil for its growth. Its appearance and rapid rate of growth might easily lead the practitioner to mistake its identity for something more ominous.

Malaria as a cause of diarrhoea--a review

Malaria causes a number of clinical complications, including diarrhoea. There are relatively few reports on the frequency of diarrhoea in malaria, but diarrhoea attributable to malaria is thought to be more common among children and nonimmune adults with hyperparasitaemia. The reported incidence of diarrhoea during malaria varies from 5 to 38%. The pathological changes in patients infected with malaria are very complex and involve many organs, including the small bowel. However, the causes of gastrointestinal manifestations during malaria are still not clear, and the mechanism of diarrhoea during malaria is likely to be multifactorial. Massive gastrointestinal bleedings with multiple foci of mucosal haemorrhage have also been observed. Tumor necrosis factor has been implicated in malaria and free oxygen radicals which can cause tissue injury in the liver, pancreas and intestine are enhanced during malaria infection; this can result in various disorders of the digestive system including diarrhoea and intestinal bleeding. Prostaglandins and cyclic AMP may also be involved in the development of diarrhoea in malaria.

Control of mosquito breeding through Gambusia affinis in rice fields

Studies on mosquito breeding and its control through Gambusia affinis in nursery and paddy fields after transplantation of seedlings were carried out during June to October 1991 in about 10 ha rice field area. Six anopheline species, viz. An. culicifacies, An. annularis, An. subpictus, An. nigerrimus, An. barbirostris and An. aconitus, and four culicine species, viz. Cx. tritaeniorhynchus, Cx. bitaeniorhynchus, Cx. quinquefasciatus, and Aedes sp. could be identified. These were found breeding in rice fields with fluctuations in their percentage composition, exhibiting species succession in different months. G. affinis survived well in submerged rice fields and provided 87.8% mosquito larval control. In rice fields which exhibited intermittent drying up leading to formation of pools, puddles etc., moderate larval control was achieved. However, in nursery rice fields, this method was not applicable. Mosquito larval control through larvivorous fish in rice fields can be achieved but the method has limitations.

Prevalence of filariasis in rural areas of Shahjahanpur district (Uttar Pradesh)

Night blood survey was carried out during May, 1990 to December, 1991 in 18 villages of 5 Primary Health Centres of district Shahjahanpur (UP), to find out the prevalence of filariasis in the area. Out of 2141 individuals surveyed randomly, 217 were found positive for microfilariae of Wuchereria bancrofti. The microfilaria rate, filarial disease rate and filarial endemicity rates were 10.1, 11.4 and 18.8 per cent respectively. An entomological survey revealed Culex quinquefasciatus as the vector. The average man hour density was 25.8. It is clear from the results that filariasis is more endemic in rural areas than urban area of Shahjahanpur as observed by local filariasis control unit.

Availability and utility of local fishes of Shahjahanpur for mosquito control

A survey of fishes in Shahjahanpur in different aquatic habitats revealed 35 indigenous fish species. Out of 35 fish species, 24 were found feeding on mosquito larvae of which 6 species, viz. Chela bacaila, Puntius stigma, Rasbora daniconius, Esomus danricus, Colisa fasciatus and Danio sp., had good larvivorous potential. Most of the fish species preferred to feed on III and IV instar larvae. In the presence of planktonic food, the consumption capacity of fishes for mosquito larvae was lesser on third day (D3) of observation than on first day (D1). The difference in the consumption of mosquito larvae between D1 and D3 was significant (P < 0.01). Similarly, difference in the feeding capacity of fishes in the months of September and January was highly significant (P < 0.001). But there was no seasonal variation in the preference of instar-wise consumption. Indigenous fish species such as C. fasciatus, E. danricus, P. stigma, R. daniconius and Danio sp. could therefore play a significant role in controlling mosquito breeding in this area.

Gambusia affinis: dispersal due to floods and its failure to colonize new water bodies in Shahjahanpur District (U.P.)

In villages of District Shahjahanpur, 122 decentralized Gambusia multiplication ponds were established to cover the need of the entire district. Profuse breeding of Gambusia was observed in these ponds. The fishes are being successfully used in mosquito control all over the district. In July 1990 there was a widespread flood due to which 70 Gambusia multiplication ponds were affected and the fish was washed away in large numbers, leaving only a scanty population in the flood-affected ponds. We utilized this opportunity to study the natural dispersal and colonization of Gambusia in different aquatic habitats. The study revealed that Gambusia was either not found in most habitats or was present in very small numbers, and on its own Gambusia was unable to eliminate the local fauna to become a dominant species. Predatory fishes and birds played a major role in eliminating Gambusia. Gambusia is therefore unlikely to pose any ecological hazard in vector-control programmes.