Mercuric chloride induced alterations in the intestinal transport of glucose and fructose in the fresh water murrel Channa punctatus

The effect of five concentrations of mercuric chloride (10 mM, 5 mM, 1 mM, 0.5 mM, and 0.l mM) on the uptake of glucose and fructose from the intestine of the fresh water murrel Channa punctatus after 15, 30 and 60 min was studied. Intestinal glucose and fructose transport was also assessed in fish exposed to a sublethal concentration (3 μg l^?1) of mercuric chloride for 10 and 30 days. The results show that the uptake of glucose and fructose from the intestine was reduced by all five concentrations of mercuric chloride. Maximum reduction was observed after 60 min of exposure to 10 mM mercuric chloride. The rate of absorption of glucose and fructose increased with time in controls and in all concentrations of mercury except the highest concentration (10 mM) where the rate of absorption decreased gradually. The reduction in the rate of absorption of the two sugars was not dependent on the concentration of mercury in the instilled medium. In fish exposed to mercuric chloride in laboratory media, the reduction of glucose and fructose absorption was greater after 30 days of exposure than after 10 days.     

Genetic resource enhancement by isolation of diversegenotypes from seed progeny in predominantly sterile rose scentedgeranium Pelargonium graveolens

Four new accessions (BSP1-4) of rose scentedgeranium Pelargonium graveolens were derivedfrom the spontaneous half-sib seed progeny of mostly sterilepopulations of the cultivar accession Bipuli. The seed producingplants of Bipuli had been growing among the populations of cultivaraccessions Hemanti and Kunti in the temperate agroclimate ofKodaikanal, Tamilnadu in India. The four new accessions were comparedwith the cultivar accessions Bipuli, Hemanti and Kunti in fieldexperiments under subtropical agroclimate of Lucknow, Uttar Pradeshfor essential oil yield and quality related traits and in terms oftheir RAPD profiles. The crop yield and essential oil parameters andDNA profiles of the four new accessions and three cultivar accessionsallowed the conclusion that the accessions BSP-1, BSP-2 andBSP-3 were Bipuli × Kunti hybrids and BSP-4was a Bipuli × Hemanti hybrid. The accession BSP-4demonstrated hybrid vigour in several of the essential oil yieldrelated traits; on average basis it out yielded other accessions by afactor of about 2.4. The essential oil of BSP-4 had 89%rhodinol content in which citronellol to geraniol ratio was 1:1 andthe contents of isomenthone, menthone, 10-epi--eudesmol, 6,9-guaiadiene, decanoic acid andisodecanoic acid were relatively lower than in the oils of accessionsBipuli and/or Hemanti. The present study has shown a way for thegeneration of new genotypes in rose scented geranium in which thecultivars have been vegetatively maintained for decades and thegenetic resources are scanty.     

Generation of a large combinatorial library of the immunoglobulin repertoire in phage lambda

A novel bacteriophage lambda vector system was used to express in Escherichia coli a combinatorial library of Fab fragments of the mouse antibody repertoire. The system allows rapid and easy identification of monoclonal Fab fragments in a form suitable for genetic manipulation. It was possible to generate, in 2 weeks, large numbers of monoclonal Fab fragments against a transition state analog hapten. The methods described may supersede present-day hybridoma technology and facilitate the production of catalytic and other antibodies.     

Ectopic hepatocellular carcinoma in a dog

CASE HISTORY: A 14-year-old neutered male Bearded Collie was presented with a history of recurrent, intermittent urinary incontinence of 7 years duration.

CLINICAL FINDINGS: A large, firm, non-painful mass was found in the mid-abdominal region on palpation. Ultrasonography of the mass revealed a compartmentalised structure with mixed echogenicity, and which did not appear to be associated with any of the abdominal organs. Ultrasound-guided fine needle aspirates contained several clusters of epithelial cells with cytological features of hepatocytes. At exploratory laparotomy, the mass was found in the gastrosplenic ligament within the greater omentum.

PATHOLOGICAL FINDINGS AND DIAGNOSIS: Histopathologically, the mass consisted of sheets of hepatocytes, but without the characteristic hepatic architecture. The cells showed moderate variation in nuclear size and were sometimes binucle- ate. A diagnosis of hepatocellular carcinoma (HCC) in the mesentery was made.

CLINICAL RELEVANCE: The presence of ectopic hepatic tissue has been reported rarely in man and cats, but not in the dog. Neoplastic transformation of ectopic hepatic tissue is seen in man. This is the first report of the presentation, clinical findings and treatment of a dog with ectopic HCC.     

The effect of fertility control on the transmission of bovine tuberculosis in wild brushtail possums

AIM: To determine the effect of fertility control on the rate of transmission of bovine tuberculosis (Tb), caused by Mycobacterium bovis, in brushtail possums (Trichosurus vulpecula).

METHODS: At two study sites with a history of Tb infection in the resident possum population, a sample of adult male and female possums (n=50), determined by palpation to be Tb-free, was surgically sterilised by gonadectomy. A sample of untreated Tb-free male and female possums (n=54) served as controls. Each study site was trapped every 2 months over a 3-year period, and the Tb status of the individuals in the trial assessed. At the conclusion of the trial, all remaining experimental individuals were killed, necropsied and examined for characteristic lesions typical of Tb. The rate of transmission of Tb infection was estimated using the incidence of tuberculous cases in the experimental animals and comparing it between sites, sex and sterilisation treatment.

RESULTS: Sterilisation by gonadectomy resulted in a reduction in the rate of transmission of Tb in male possums by 53%, but a corresponding increase in sterilised females for reasons that are still unclear. However, this interaction was statistically weak (p=0.10). When the sexes were combined, there was no overall effect of sterilisation on the rate of transmission of Tb (p=0.43). Sterility treatment notwithstanding, there was a highly significant difference in the rate of transmission between the sexes (p=0.01), being almost one order of magnitude higher in untreated males compared with untreated females.

CONCLUSIONS: Although lacking strong statistical support, these results suggest that fertility control that targets endocrine control of fertility may provide some additional benefits for disease control over that achieved by reductions in population density, by reducing the rate of transmission of M. bovis in male possums. However, additional studies are needed to confirm the validity of these results. The large difference in the rate of transmission of M. bovis in untreated males compared with untreated females suggests that transmission of Tb among males may be an important driver of the dynamics of Tb infection in possums.     

The Acidic Probe LysoSensor™ is not Useful for Acrosome Evaluation of Cryopreserved Ram Spermatozoa

To try new acrosomal probes for assessing ram spermatozoa, we compared the LysoSensor^? probe, which labels acidic organelles, with the frequently used peanut agglutinin acrosomal probe (PNA‐PE; phycoerythrin as fluorescent moiety). The previous microscopic observations showed a lack of relationship of LysoSensor^? with acrosomal status. Semen was obtained from five rams and frozen in four pools. Each pool was analysed carrying out a triple staining propidium ioide/PNA‐PE/LysoSensor^? Green DND‐189 to test acrosome labelling, and a double staining SYBR‐14/PI, to assess sperm viability. Stained samples were analysed by flow cytometry. All measurements were replicated. Data were processed using agreement and repeatability tests. LysoSensor^? labelling did not agree with PNA (mean of differences: 30.8%; coefficient of agreement: 22.6%), confirming microscopic observations. Nevertheless, when LysoSensor^? was compared with SYBR‐14/PI, the agreement was high (mean of differences: ?0.05%; coefficient of agreement: 5.07%). Repeatability of both methods was high and similar. LysoSensor^? did not seem to specifically stain the acrosome, but it may accumulate in the cytoplasm and label viable spermatozoa. Therefore, LysoSensor^? might not be used as an acrosomal probe in ram spermatozoa, but it could be used in other kind of studies, taking advantage of its pH sensitivity.