Precocene II metabolism: Comparative in vivo studies among several species of insects,and structure elucidation of two major metabolites

Several species of insects, exhibiting varying responsiveness to the juvenile hormone antagonist precocene II (6,7-dimethoxy-2,2-dimethylchromene), were challenged topically with a tritiated preparation of the title compound. Metabolism of [³H]precocene II was subsequently examined by withdrawing hemolymph samples from treated animals at appropriate time intervals and characterizing the extractable radiolabel chromatographically. Quantitative (or qualitative) differences observed between the respective metabolic profiles were found not correlative with specimen sensitivity to precocene. Production of two heretofore unreported metabolites, identified by spectral and chemical means as O-β-glucosides of 6- and 7-monodemethylated precocene II, was demonstrated in both sensitive and insensitive species. No evidence for the presence of a hemolymphborne, biologically effective “activated metabolite” produced in vivo by precocene-susceptible insects could be found. The latter finding may well argue for in situ bioactivation of precocene at the target tissue(s) by these sensitive insects.     

Clinical comparison of recovery from total intravenous anesthesia with propofol and inhalation anesthesia with isoflurane in dogs

The characteristics of recovery from total intravenous anesthesia (TIVA) with propofol and inhalation anesthesia with isoflurane was clinically compared in 149 client-owned dogs that anesthetized for surgical or diagnostic procedures. In all dogs, anesthesia was induced with an intravenous injection of propofol following premedication with acepromazine or diazepam. As a result, 58 dogs anesthetized with propofol-TIVA showed slower but smoother recovery than 91 dogs anesthetized with isoflurane anesthesia. The dogs stood at 34.5 +/- 19.3 and 27.7 +/- 17.2 min after propofol-TIVA and isoflurane anesthesia, respectively. Adverse effects, including hypersalivation, neurologic excitement (paddling, muscle tremor/twitching, opisthotonos) and vomiting/retching, were observed in similar infrequent incidences during the recovery from both anesthetic protocols. Propofol-TIVA is suggested to be an alternative anesthetic protocol for canine practice.     

The Combinatorial Effect of Different Equex STM Paste Concentrations,Cryoprotectants and the Straw‐Freezing Methods on the Post‐Thaw Boar Semen Quality

This study was to evaluate the combinatorial effect (14 treatments, A–N) of different Equex STM paste concentrations, cryoprotectants and the straw‐freezing method on the post‐thaw boar semen quality. Two ejaculates were collected from each of nine boars (three boars from each of three breeds). Semen was diluted in extenders with different concentrations of Equex STM paste and different cryoprotectants [glycerol or dimethylacetamide (DMA)] before cryopreserving via liquid nitrogen or dry ice. Motility, viability, percentage of spermatozoa with intense acrosomal staining and with normal morphology of post‐thaw sperm were evaluated. The qualities of thawed semen were best preserved in treatment H (extender with 0.5% Equex STM paste and 5% glycerol and freezing by dry ice) and were worst in treatment B (extender with 0% Equex STM paste and 5% DMA and freezing by dry ice). Significant difference (p < 0.05) was present in post‐thawed sperm motility (63% vs 27%), sperm viability (70% vs 33%) and sperm acrosomal integrity rate (68% vs 29%) between treatments H and B. However, sperm proportion with normal morphology showed no significant difference among treatments (66% vs 66%; p > 0.05). Moreover, statistical analysis suggests that no significant difference was present in semen quality among breed or individual donors (p > 0.05). These findings suggest that Equex STM paste improved the cryosurvival efficiency of boar sperm, and the favourable straw‐freezing method changes between glycerol and DMA.     

Early Pregnancy Detection of Iraqi Riverine Buffalo (Bubalus bubalis) Using the BioPRYN Enzyme‐Linked Immunosorbent Assay for PSPB and the Progesterone Assay

This study was undertaken to detect pregnancy in Iraqi riverine buffalo (Bubalus bubalis) using three different methods (rectal palpation, plasma progesterone concentration and detection of the presence of pregnancy‐specific protein B (PSPB) with the BioPRYN^® enzyme‐linked immunosorbent assay (ELISA) test. The aim of the study was to identify the most sensitive, early and accurate method for detecting pregnancy. Twenty‐two female riverine buffalo that were 6.0 ± 0.93 years old were used. Four blood samples per buffalo were taken via jugular venipuncture at days 22–24, 32–34, 42–44 and 58–61 post‐mating (PM) to measure the progesterone concentration (ng/ml) and to detect the presence of plasma PSPB. The rectal palpation method was employed to evaluate all buffalo on days 42–44 and 58–61 PM. The BioPRYN^® test differed (p < 0.01) from the other tests with earlier accuracy for detecting pregnant and non‐pregnant buffalo. Eighty‐eight percent of pregnant and 76.9% of non‐pregnant buffalo were distinguished early (days 22–24 PM) using BioPRYN^® and plasma PSPB‐ELISA level (2.09 ± 0.12 ng/ml) in relation to 66.7% and 53.9% detected using the progesterone assay at similar days (4.30 ± 0.40 ng/ml). In conclusion, these results described, for the first time, the early and accurate pregnancy detection of water riverine buffalo using BioPRYN^® technology and provided the plasma levels of PSPB using an ELISA test. These findings will improve the reproductive and productive efficiency of Iraqi riverine buffalo by adapting the recent management and reproductive strategies in Iraq and in the world.     

Characterization of the pattern of cytokeratin proteins in the epidermal cells of loach,Misgurnus anguillicaudatus (Cyprinformes)

The pattern of cytokeratin proteins in the epidermal cells of loach was studied by immunotechniques and partial separation of the epidermal cells. Two monoclonal antibodies, namely 8F7 and 1C45, against the cytokeratin proteins of the loach epidermis were prepared. these two monoclonal antibodies exhibit distinctive results in immunohistochemical staining. The 8F7 monoclonal antibody stains mainly with the epithelial cells, while the 1C45 monoclonal antibody stains specifically with the club cells. The pattern of cytokeratin proteins in the club cells and the epithelial cells of various epidermal layers was further determined by partial separation of these cells. Immunoblotting analysis of the cell fractions confirms the cytokeratin proteins to be differentially expressed in the club cells and the epithelial cells. However, the cytokeratin proteins expressed in the epithelial cells of the basal, middle and outer layers are same. The results indicate that differentiation of the epithelial cells seems limited during their translocation from basal to upper layers, but in those cells that do differentiate into club cells, the cytokeratin pattern changes.     

A Chemoautotrophically Based Cave Ecosystem

Microbial mats discovered in a ground-water ecosystem in southern Romania contain chemoautotrophic bacteria that fix inorganic carbon, using hydrogen sulfide as an energy source. Analysis of stable carbon and nitrogen isotopes showed that this chemoautotrophic production is the food base for 48 species of cave-adapted terrestrial and aquatic invertebrates, 33 of which are endemic to this ecosystem. This is the only cave ecosystem known to be supported by in situ autotrophic production, and it contains the only terrestrial community known to be chemoautotrophically based.     

Inhibition of juvenile hormone biosynthesis in the tobacco hornworm, Manduca sexta, by a bisthiolcarbamate juvenoid and related compounds

Biosynthesis of juvenile hormone in the tobacco hornworm, Manduca sexta, is inhibited by the bisthiolcarbamate juvenoid N-ethyl-1,2-bis(isobutylthiolcarbamoyl)ethane both in vitro and in vivo. In vitro an extremely steep dose-response curve was obtained with an ID₅₀ value of 6 × 10^?6M. However, in vivo topical treatment with the compound resulted in mild JH antagonistic symptoms, suggesting rapid metabolism of the compound. In agreement with results from metabolic studies performed on plants and in mammals, sulfoxidation of the thiocarbamate S-(4-chlorobenzyl)N,N-diethylthiocarbamate resulted in an enhanced inhibitory effect on JH biosynthesis in vitro. This suggests that the corresponding thiocarbamate sulfoxides may act as intermediates in carbomylating critical thiol sites important in the terpenoid biosynthesis pathway. Furthermore, this study shows that these prototype compounds are interesting tools for further investigation of chemical inhibition of JH biosynthesis in insects.     

Comparative Expression Analysis of Gametogenesis‐Associated Genes in Foetal and Adult Bubaline (Bubalus bubalis) Ovaries and Testes

This study was conducted to identify and analyse the expression of gametogenesis‐associated genes and proteins in foetal and adult buffalo gonads of both the sexes. Relative quantification of the genes was determined by qPCR and Western blotting. Immunohistochemistry was also performed for various gametogenesis‐associated proteins in foetal and adult gonads of both the sexes. We observed significantly (p < 0.05) increased expression of primordial germ cell‐specific, meiotic as well as genes associated with oocyte maturation and development in foetal ovaries as compared to the adult ones. However, significantly (p < 0.05) increased expression of proteins associated with oocyte maturation like GDF9 and ZP4 was found in adult ovaries, indicating temporal regulation of mRNA translation during oogenesis. Meiotic genes showed significantly (p < 0.05) increased expression in adult testes as compared to foetal testes and ovaries, indicating onset of meiosis at a later stage in spermatogenesis. In general, the expression of primordial germ cell‐associated as well as meiotic genes was higher in adult testes, indicating the increased biological activity in the organ. Immunohistochemistry revealed localized expression of gametogenesis‐associated proteins in ovarian follicles and seminiferous tubules of testes, while the surrounding somatic tissues were devoid of these proteins. The study gives an understanding of the sequential and temporal events of gene expression as well as mRNA translation during male and female gametogenesis. It could also be concluded that follicles and seminiferous tubules are the functional units of the female and male gonads, respectively, and their function could be enhanced by appropriate chemical and genetic intervention of the somatic tissue immediately surrounding them. This assumes importance in the context that buffalo attains sexual maturity at an older age of 2–3 years and have smaller ovaries with lesser number of primordial follicles in comparison with cattle, which is suggested to be the main reason of their poor breeding performance.     

Evaluation of head-out constant volume body plethysmography for measurement of specific airway resistance in conscious, sedated sheep

OBJECTIVE: To evaluate the use of a modified whole body plethysmograph in awake sheep. ANIMALS: 10 healthy adult sheep. PROCEDURE: Concurrent measurements of specific airway resistance (sR(aw)) and pulmonary resistance (R(L)) were obtained using a novel noninvasive head-out constant-volume plethysmograph and esophageal balloon-pneumotachography, respectively. All data were collected before and after external resistive loading with 1 and 5.6 cm H2O/L/s. Functional residual capacity (FRC) was measured by helium dilution for computation of airway resistance (R(aw)) preloading (R(aw) = sR(aw)/FRC). RESULTS: The sR(aw) and R(L) were closely correlated in 10 adult sheep. Additionally, sR(aw), and R(L) accurately reflected the magnitude of added resistance. The mean FRC was 52 mL/kg and used to calculate R(aw). At baseline, the values for R(aw) were significantly correlated with sR(aw) and R(L). CONCLUSIONS AND CLINICAL RELEVANCE: Precise measurements of sR(aw) and R(aw) at baseline and sR(aw) after external resistive loading were obtained by use of this novel noninvasive plethysmographic technology. This method should have application to veterinary patients or animals used in research in which noninvasive rapid or serial measurements of sR(aw) in the conscious state are required.