Effect of intrapartum fetal stress associated with obstetrical interventions on viability and survivability of canine neonates.

AIM: This study was conducted with the objective of identifying and evaluating intrapartum fetal stress in connection with the type of delivery in bitches. MATERIALS AND METHODS: A total of 26 bitches between 1 and 5 years, belonging to 10 different breeds were evaluated. Bitches were subjected to detailed clinico-gynecological examination based on history. Neonatal stress associated with spontaneous whelping (SW), assisted whelping (AW), and emergency cesarean section (EC) was evaluated using umbilical vein lactate (UL) estimation by collecting the blood from umbilical vein. RESULTS: A high umbilical vein lactate value was associated with fetal distress. The mean umbilical lactate value was highest in EC (12.54±0.8 mmol/L) followed by AW (8.86±0.9 mmol/L) and the lowest value was found in SW (7.56±0.58 mmol/L). A significant increase (p<0.05) in umbilical lactate level was observed in EC group of canine neonates compared with AW and SW groups. Overall mean umbilical lactate values of neonates which died within 24 h (13.31±1.08 mmol/L) and the neonates which survived beyond 24 h (8.87±0.55 mmol/L) differed significantly at 5% level. CONCLUSION: Immediate identification of neonatal distress by use of umbilical vein lactate estimation is helpful for the clinician to undertake resuscitation or medical therapy to ensure better neonatal survivability.

Effect of cholesterol supplementation on cryosurvival of goat spermatozoa.

AIM: Sperm membrane cholesterol influences cryodamage during cryopreservation. The present study was carried out to evaluate the effect of varying cholesterol levels in Tris based extenders on the freezability of sexually healthy Malabari buck semen. MATERIALS AND METHODS: A total of 48 ejaculates from two adults healthy sexually healthy Malabari bucks were utilized for the study. The collected and pooled ejaculates were divided into four groups with Group I serving as Control - I, Group II and III were treated with 1 mg and 2 mg of cholesterol-loaded-cyclodextrin (CLC)/120 × 10(6) spermatozoa, respectively, and Group IV, treated with 1 mg methyl-ß-cyclodextrin (MßCD) served as Control - II. Manual freezing was carried out to cryopreserve the treated and control spermatozoa. RESULTS: Treatment of semen samples with CLC resulted in improved maintenance of sperm motility at pre-freeze and post-thaw stages of cryopreservation without affecting hypo-osmotic swelling response. Treatment of semen with 1 mg of CLC/120 × 10(6) spermatozoa was observed to be better than treatment with 2 mg of CLC/120 × 10(6) spermatozoa. In general, MßCD treatment was found to result in significantly lower sperm characteristics than those of Control - I and CLC treatment at pre-feeze and post-thaw stages and when incubated up to 4 h. CONCLUSION: Cholesterol treatment of sexually healthy Malabari buck semen was found to hold promise for improving cryopreservability of spermatozoa.

Comparative efficacy of bromocriptine, cabergoline and thyroxine in inducing oestrus in bitches.

Forty bitches in anoestrus for more than six months from the last heat, with a serum progesterone level less than 1 ng/ml were subjected to oestrus induction trials using anti-prolactin drugs and levothyroxine, once daily orally for 20 consecutive days. The mean serum progesterone level among them was found to be 0.57 +/- 0.03 ng/ml. Out of 10 animals treated in each group, five (50%) in Group I (bromocriptine @ 50 microg/kg body weight), nine (90%) in Group II (cabergoline @ 5 microg/kg body weight), eight (80%) in Group III (thyroxine @10 microg/kg body weight) and seven (70%) in Group IV (thyroxine @ 5 microg/kg body weight) responded by evincing proestrual bleeding. The mean (+/-SEM) time taken from initiation of treatment to onset of proestrual bleeding in Groups I, II, III and IV was 28 +/- 3.39, 13.44 +/- 3.12 (P < 0.05), 24.50 +/- 3.18 and 33 +/- 2.21 days respectively. The mean (+/-SEM) duration of proestrus and oestrus in the treatment groups was 9.80 +/- 0.86, 10.11 +/- 0.68, 11.25 +/- 0.88 and 10.71 +/- 0.68 days and 7.60 +/- 0.24, 8 +/- 0.29, 8.5 +/- 0.63 and 7.85 +/- 0.46 days respectively. The conception rate in relation to the number of animals responding to oestrus induction in the treatment groups was 80%, 78%, 63% and 57%, respectively. The mean (+/-SEM) gestation length calculated from the last breeding date and litter size in the treatment groups varied from 60.50 +/- 1.55 to 64.00 +/- 0.82 days and 5.14 +/- 0.34 to 6.40 +/- 0.40 respectively.

Interspecific hybridization and genetic variability of Phlebotomus sandflies.

The first successful hybridization is reported between Phlebotomus papatasi and P. duboscqi, two important Old World sandfly vectors of leishmaniasis and other diseases. Laboratory strains of P. papatasi and P. duboscqi were separable by six diagnostic enzyme loci: Est-3, Idh-1, Mdh-2, Mpi, Tre-1 and Tre-3. Hybrids between the two species were verified by the recovery of heterozygous isozyme patterns for the diagnostic loci. No F2 or backcross progeny were obtained. P. papatasi was separated from P. bergeroti by three diagnostic enzyme loci: Est-3, Mpi and Pgd. The isozyme patterns of P. bergeroti contain elements of both P. duboscqi and P. papatasi, although seven diagnostic loci (Est-3, Idh-1, Me, Mpi, Pgd, Tre-1 and Tre-3) separated P. bergeroti from P. duboscqi. Genetic variability profiles of the three species were established for 20 enzyme loci. Three geographically distant strains of P. papatasi from Calcutta, Maharashtra and Israel had isozyme genetic distances of < 0.05. The recently established Calcutta strain showed an unexpectedly low genetic variability with only one (Idh-2) of 20 loci being polymorphic (average heterozygosity of 1.9%) in contrast to 5-8 polymorphic loci (10-12% heterozygosity) in the Maharashtra and Israel strains. Mass and single pair crosses between the three P. papatasi strains were fertile with normal progeny numbers. Thus we found no signs of speciation in P. papatasi.

The effect of anti-sandfly saliva antibodies on Phlebotomus argentipes and Leishmania donovani.

A study was undertaken to find the effect of repeated bites of the sandfly, Phlebotomus argentipes, on its host as well as on the vector itself. The study also aimed to find the effect of the immune serum on the parasite, Leishmania donovani, naturally transmitted by the vector. The hamster which was exposed to sandfly feeding showed good antibody titre against the sandfly salivary-gland secretion, which indicates that the salivary-gland secretion is immunogenic in nature. The result also revealed that the feeding attraction of the females, which has been expressed as the percentage of engorgement, gradually decreased as the mortality rate increased during the subsequent bites. Similar mortality rate was observed when the flies were fed with the immune sera through an artificial membrane feeding method. When the sandflies were fed both with the immune sera and the blood-parasite (L. donovani) suspension, in addition to the major loss of the number of vectors, there was an inhibition of development in the gut and a concomitant reduction in the migration of the parasite in the surviving females. These results indicate that the anti-sandfly saliva immune sera probably bind with the respective antigen-presenting sites of the sandfly salivary gland and, thus, cause the sandfly death. The possible explanation of the inhibition of the forward movement of the parasites is that the attraction of the parasites to the oesophagus, mediated by the sandfly saliva, is inhibited by the anti-saliva antibodies. The importance of anti-sandfly saliva antibodies as a tool of vector control and also to block the transmission of leishmaniasis has been indicated.

Short report: Leishmania DNA in Phlebotomus and Sergentomyia species during a kala-azar epidemic.

The presence of Leishmania donovani DNA in sand flies caught in Indian kala-azar patients' dwellings during the epidemic of 1990-1992 was studied using the polymerase chain reaction (PCR). Amplification of miniexon-derived RNA genes and gpG3 mRNA was achieved in single Phlebotomus argentipes, P. papatasi, and Sergentomyia babu flies. The data suggest the possible involvement of multiple sandfly species in kala-azar transmission.

Diagnostic importance of female external genital structure of phlebotomine sand flies (Diptera: Psychodidae) as observed by scanning electron microscopy

Morphological description of sand flies has remained a neglected area. The different organs used in taxonomy have not yet been described adequately with the scanning electron microscopy (SEM). We have examined the external genital structures of females of three Old World phlebotomine sand flies under SEM and recorded the morphological variations of the organs. We have found the female external genital strutures of the three species varied considerably in morphology. The importance of the female external genital structures in sand fly identification is indicated.

Breeding places of Phlebotomus argentipes Annandale and Brunetti (Diptera: Psychodidae) in West Bengal, India.

A search for the breeding places of Phlebotomus argentipes Annandale and Brunetti was undertaken in West Bengal during 1988-1990. Sugar flotation technique was applied for the isolation of larvae from the collected soil samples and emergence trap and sticky paper trap were used for the collection of adults. Soil incubation method was followed for the collection of emerged adults from the soil sample. A total 131 soil samples were analysed by flotation technique which produced 19 immature stages--7 from indoor and 12 from outdoor habitat. Soil incubation technique produced 38 adults of which 18 from indoor and 20 from outdoor. With the help of emergence trap 26 and 43 flies were collected from indoor and outdoor respectively. The number of immature stages and adult flies recovered from the outdoor showed higher recovery during post-monsoon months and lower in pre-monsoon and monsoon months. The result of this investigation indicated that probably the majority of the indoor catches are due to the migration of outdoor-produced sandflies specially in close surroundings where dried cow dung droppings were left. The necessity of spraying in these close areas in addition to indoor areas has been indicated to control the sandflies by antilarval measure.

Gel diffusion analysis of host preference pattern of Anopheles subpictus in West Bengal, India.

Host preference pattern of Anopheles subpictus was studied from cattlesheds and human dwellings of Uttarpara, Hooghly, West Bengal using a modified gel diffusion technique. Our results reveal that An subpictus is becoming less zoophagic in this area.

Metacyclogenesis of Leishmania spp: species-specific in vitro transformation, complement resistance, and cell surface carbohydrate and protein profiles.

Metacyclic (stationary) and logarithmic (log) forms of promastigotes of Leishmania donovani and Leishmania major were characterized in several ways. The highly active metacyclic forms were larger with more protein and less carbohydrate. The flagellum increased in length 2.4 times in L. major as compared to 1.8 times in L. donovani. Resistance to complement-mediated lysis by normal human serum of in vitro grown Leishmania promastigotes was related to the species, the growth phase in culture, and also the temperature. Metacyclic forms of both species had a much increased resistance to killing by normal serum at different temperatures. Differences in membrane-exposed carbohydrates were detected by fluorescein-conjugated lectins. Peanut agglutinin and Ulex agglutinin I differentiated log and stationary phase promastigotes of L. major. Higher amounts of acid phosphatase were demonstrated in the metacyclic phase. Differences in polypeptides were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Two polypeptides of approximately 51 and 114 kDa were found exclusively in metacyclic promastigotes of both species, whereas 38- and 23-kDa polypeptides were lost or reduced during transformation from log to metacyclic phase promastigotes of L. donovani. In addition, a 75-kDa polypeptide was expressed only in metacyclic promastigotes of L. major.

Blood meal analysis of Phlebotomus argentipes in eight districts of West Bengal.

Eight districts of West Bengal (India) were surveyed for the biting habit of Phlebotomus argentipes using agar gel diffusion method. Blood meal indices were found different in the two biotopes, human dwellings and cowsheds. A total of 395 blood meals were analyzed. The blood meal indices in the human dwellings were human 68.8 per cent, cow 38.9 per cent, both human and cow 10.2 per cent, others 2.5 per cent and in the cowsheds: human 19.7 per cent, cow 91.6 per cent, human and cow 13.9 per cent and others 2.5 per cent. These indicated that P. argentipes did not show preference to any blood meal.

Kinetoplastid flagellates: surface-reactive carbohydrates detected by fluorescein-conjugated lectins.

Membrane-associated carbohydrate residues of 3 isolates of Leishmania derived from etiological agents of visceral leishmaniasis (VL), postkala-azar dermal leishmaniasis (PKDL), and cutaneous leishmaniasis (CL), as well as 2 other nonpathogenic insect gut kinetoplastid flagellates, Bodo sp. and Herpetomonas sp., were characterized with the aid of 8 fluorescein-conjugated lectins. Four lectins, concanavalin A, Dolichos biflorus, phytohemagglutinin P, Ricinus communis agglutinin, bound to all kinetoplastid flagellates at different concentrations. All Leishmania promastigotes showed reactions with Ulex agglutinin. Although these lectins were bound to all kinetoplastids, the site and intensity of binding was different. All skin-dwelling Leishmania parasites, viz., Leishmania donovani of PKDL and Leishmania tropica of CL showed unique selectivity toward peanut agglutinin (PNA), soybean agglutinin, and wheatgerm agglutinin (WGA). More interestingly, Herpetomonas showed positive fluorescence with PNA and WGA, whereas Bodo was negative. The results demonstrated that no lectin could distinguish between the pathogenic and nonpathogenic status of kinetoplastid flagellates. Moreover, the antigenic (carbohydrate) profiles of Herpetomonas corresponded more closely to those of L. tropica, whereas Bodo shared some common lectin receptors with L. donovani of VL.

Characterization of potentially pathogenic free-living amoebae in sewage samples of Calcutta, India.

1. It is widely accepted that foul or polluted environments are the principal sources of potentially pathogenic species of free-living amoebae. The present paper is the first report of occurrence of potentially pathogenic free-living amoebae in sewage samples of Calcutta, India. 2. We describe the occurrence, isolation, specific identification and comparative mouse pathogenicity test of two pathogenic amoebae, viz., Naegleria fowleri (N. aerobia) Carter, 1970, causing human meningoencephalitis and Acanthamoeba castellanii Douglas, 1930, causing granulomatous amoebic encephalitis, and one non-pathogenic amoeba, viz., A. astronyxis Ray and Hayes, 1959, in sewage samples of Calcutta, India. 3. The existence of both pathogenic and non-pathogenic amoebae living side by side is of considerable epidemiological relevance.

Characterization of potentially pathogenic free-living amoebae in sewage samples of Calcutta, India

1. It is widely accepted that foul or polluted environments are the principal sources of potentially pathogenic species of free-living amoebae. The present paper is the first report of occurrence of potentially pathogenic free-living amoebae in sewage sample of Calcutta, India. 2. We describe the occurrence, isolation, specific identification and comaprative mouse pathogenicity test of two pathogenic amoebae, viz., Naegleria fowleri (N. aerobia) carter, 1970, causing human meningoencephalitis and Acanthamoeba castellanii Douglas, 1930, causing granulomatous amoebic encephalitis, and one non-pathogenic amoeba, viz., A astronyxis Ray and Hayes, 1959, in sewage samples of Calcuta, India. 3. The existence of both pathogenic and non-pathogenic amoebae living side by side is of considerable epidemiological relevance

Excreted factors and membrane-associated carbohydrates of Indian leishmaniae.

Antigenic identity between the cell surface carbohydrate ligands and their excreted factor (EF) in all forms of Indian leishmaniasis were assessed by 11 carbohydrate-specific lectins. Our results demonstrated that 3 lectins, viz. PNA, SBA and WFA showed unique selectivity towards skin-dwelling parasites. The EFs of visceral leishmaniasis (VL), post-kala-azar dermal leishmaniasis (PKDL) and cutaneous leishmaniasis (CL) formed band against ConA at 1000, and 500 micrograms/ml concentration, respectively. RCA-120 at 3 mg/ml concentration was positive to both Leishmania tropica and L. major, whereas SBA was specific to L. tropica, L. major and PKDL strains at the same concentration. Antisera directed against the EFs (EF-As) induced agglutination to homologous promastigotes suspension. Cross-reactivity of agglutination was observed in different strains but highest was found among PKDL and CL strains. Although PKDL cases are normally found in patients with the history of visceral leishmaniasis (kala-azar), surprisingly in this study, the surface saccharides of PKDL strains had close affinity to CL type instead of VL.