Effect of lymphoid Leukosis virus on performance of layer hens and the identification of infected chickens by tests on Meconia

The effect of subclinical infection with lymphoid leukosis virus (LLV) on the productivity traits of layer hens was investigated. In hens that shed gs-antigen of LLV to albumen, onset of sexual maturity was delayed by a mean of 11 days and the number of eggs laid was reduced -by 68 per hen up to 75 weeks of age. Shedding hens laid on average 2 g lighter eggs and of lesser specific gravity. Thirty-four % less chickens were obtained in the reproduction programmes from LLV-shedders in comparison with non-shedders. LLV had no significant effect on fertility and hatchability. Reduced egg-related performance was only directly related to LLV-shedding and dams' shedding status had no effect on the egg-related performance of their LLV-free progeny. Dams' shedding status, however, correlated with higher mortality (10% higher) among their progeny. The percentage of non-layers was also higher in progeny of LLV-shedders. Meconia were highly suitable samples for identifying both transmitting dams and infected chickens but only if the test for infectious virus was performed. ELISA on meconia was less reliable than the test for virus and therefore is not recommended for the detection of residual of infected chickens in the flocks selected for reduced gs-antigen shedding.     

Concentration and turnover of intraperitoneal hyaluronan during inflammation

Aseptic peritonitis was induced in rabbits by intraperitoneal injection of irritating agents, mainly starch suspensions. The inflammatory response was followed in the peritoneal lavage fluid by cell counts (average increase about 800-fold the first day) and hyaluronan concentration (average increase about 200-fold on the second and third days). The turnover rate of hyaluronan was studied by injecting tritium-labeled hyaluronan intraperitoneally and by following the appearance of tritiated water in serum. In control animals given trace amounts of hyaluronan, half-lives of 1–14 h were recorded. When the labeled polysaccharide had been mixed with 10 mg/ml of unlabeled hyaluronan, the half-life was approximately one day. Rabbits with ongoing peritonitis exhibited half-lives between 1 and 16 h. It was concluded that there was a large individual variation in uptake kinetics, that the removal process could be receptor mediated, and that the increase in intraperitoneal hyaluronan in peritonitis mainly was due to an increased production of the polysaccharide rather than a decreased rate of removal.     

Fine-needle aspiration of pancreatic extramedullary plasmacytoma: Possible confusion with islet cell tumor

We report two cases of extramedullary plasmacytoma (EMP) of the pancreas, diagnosed by fine-needle aspiration (FNA). Plasmacytoma of the pancreas is a rare neoplasm with only 12 cases recorded in the literature. Because of its scarcity and the cytomorphologic similarity between plasma cells and endocrine cells, EMP of the pancreas may be confused with neuroendocrine (islet cell) tumors of the pancreas. Immunohistochemical staining for light chain and/or neuroendocrine markers will prevent diagnostic error when interpreting plasmacytoid neoplasms of any site susceptible to endocrine tumors, including the pancreas. © 1994 Wiley-Liss, Inc.     

A new physical assay method for tobacco mosaic virus using a radioactive virus recovery standard and the first derivative of the ultraviolet absorption spectrum

A new physical assay method for tobacco mosaic virus is described which incorporates two improvements on previous procedures. Losses of up to 75% of virus during extraction are corrected by adding a trace of radioactive virus to leaf samples before homogenization, and determining percentage recovery of radioactivity in final virus preparations. Estimation of virus concentration in partially purified preparations is from the first derivative (dA/d lambda) of the ultraviolet absorption spectrum, using a pronounced signal from the tryptophan fine-structure absorption band at 285-293 nm. This method is highly insensitive to ultraviolet-absorbing contaminants, which cause errors and increase variation between replicates, when estimation of virus concentration is by normal measurement of ultraviolet absorption (A260). The method can be applied to at least some other viruses.     

Population study of T cell receptor V beta gene usage in peripheral blood lymphocytes: differences in ethnic groups.

The T cell receptor (TCR) V beta repertoire in peripheral blood lymphocytes (PBL) of a large number of healthy individuals was analysed by quantifying V beta-specific mRNA using the method of anchored multiprimer DNA amplification and a reverse dot blot assay. Among 16 V beta gene families examined, particular V beta genes were noted to be unequally expressed in the PBL of 70 healthy donors. The frequently used genes belong to the V beta 4, 5, 6, 8 and 13 (12) families, while V beta 1, 9 and 15 were the least frequently used gene families. This bias in gene usage was observed in all individuals. Marked deviation from the mean percentage usage was noted for some V beta genes in individuals when their PBL were examined serially, but the common pattern of biased usage was not grossly distorted. When the TCR repertoire of different ethnic groups was examined, a lower mean frequency of V beta 3.2 was seen in the repertoire of 19 Caucasians compared with 25 age-matched Samoans (P < 0.003). Conversely, the expression of V beta 5.1 and V beta 5.3 was higher in Caucasians than in 51 age-matched Polynesians (Maoris and Samoans, P < 0.003). Considering the 20% co-efficient of variation in the estimate of V beta gene usage, our data from 70 unrelated individuals suggest that in PBL, individual variations in the TCR repertoire were superimposed upon a common biased usage of V beta genes in the general population.     

Differential expression of stem cell mobilization-associated molecules on multi-lineage cells from adipose tissue and bone marrow

Our laboratory has characterized a population of stromal cells obtained from adipose tissue termed processed lipoaspirate cells (PLAs). PLAs, like bone-marrow derived mesenchymal stem cells (BM-MSCs), have the capacity to differentiate along the adipogenic, osteogenic, chondrogenic, and myogenic lineages, In order to better characterize these two multi-lineage populations, we examined the surface phenotype of both bone marrow and adipose tissue-derived cells from five patients undergoing surgery. PLA and BM-MSC cells were isolated, subcultivated, and evaluated for cell surface marker expression using flow cytometry. PLA and BM-MSC cells both expressed CD13, CD29, CD44, CD90, CD105, SH-3, and STRO-1. Differences in expression were noted for cell adhesion molecules CD49d (Integrin alpha4), CD54 (ICAM-1), CD34, and CD106 (VCAM-1). While markedly similar, the surface phenotypes of PLA and BM-MSC cells are distinct for several cell adhesion molecules implicated in hematopoietic stem cell homing, mobilization, and proliferation.     

The effect of menopause on the relation between weight gain and mortality among women

OBJECTIVE: To examine the effect of menopause on the relation between weight gain and all-cause mortality. DESIGN: Prospective cohort study of 6,030 adults (ages 25-82 years) who never smoked cigarettes, had no history of coronary heart disease, cancer, or stroke, and were enrolled in a 29-year follow-up in which anthropometric data were given at baseline and at 17 years after baseline. RESULTS: Weight gain that occurred over a 17-year interval (baseline to 17 years after baseline) increased the mortality risk of men and middle-aged women, but decreased the mortality risk of older women. Further study of the women revealed that a strong protective effect of weight gains was only evident among the leanest (25 kg/m2) postmenopausal women [HR (95% CI) = 0.81 (0.41, 1.58)] or for premenopausal women [HR (95% CI) = 1.05 (0.49, 2.25) for 25 kg/m2]. We found that the protective effect of weight gain among the leanest postmenopausal women was primarily due to a more than threefold decrease in cardiovascular disease mortality risk. One possible explanation for these findings is that weight gain increases the level of adipose-tissue-derived estrogen among lean postmenopausal women. CONCLUSION: Moderate menopausal weight gain may be well tolerated in lean women.     

Repertoire of transcribed peripheral blood T-cell receptor beta chain variable-region genes in acute rheumatic fever.

Patients with severe group A streptococcal infections have abnormalities in the Vbeta repertoire of peripheral blood T cells that are consistent with superantigen stimulation by cytoplasmic membrane proteins. The purpose of this study was to determine whether similar changes in Vbeta repertoire could be found for patients with acute rheumatic fever (ARF). The mean Vbeta repertoire of peripheral blood T cells in nine hospitalized ARF patients was similar to that of 34 controls and did not change during 6 months of follow-up in 6 of the ARF subjects. We were unable to detect changes in the Vbeta repertoire of peripheral blood T cells from patients with ARF that could be attributed to the influence of a superantigen.     

Family cancer histories predictive of a high risk of hereditary non-polyposis colorectal cancer associate significantly with a genomic rearrangement in hMSH2 or hMLH1

Hereditary non-polyposis colorectal cancer (HNPCC) results from inactivating germline mutations in a set of DNA-mismatch-repair genes, of which the most clinically relevant are hMSH2 and hMLH1. Computer-assisted pedigree risk assessment tools are available to assist in the calculation of an individual's likelihood of bearing such a deleterious mutation. One such tool, cancergene version 3.4 (http://www3.utsouthwestern.edu/cancergene) was used to assess the risk of a deleterious mutation in the genes hMSH2 and/or hMLH1 in a series of probands selected from a panel of 67 South-western Ontario kindred previously identified as likely candidates for HNPCC by established clinical criteria. A DNA sample isolated from peripheral blood leukocytes obtained from each of these probands was examined for genomic rearrangement using the multiplex ligation-dependent probe amplification (MLPA) method. Of the individuals calculated to have a risk of >50% of a hMSH2 or hMLH1 gene mutation by the CancerGene risk assessment tool, 69% (9/13) were shown to have a genomic rearrangement resulting in the deletion of one or more exons of one of these two genes. Family cancer histories predictive of a high risk of HNPCC significantly associate with a genomic rearrangement in hMSH2 or hMLH1.     

Host responses to cryoablation of normal kidney and liver tissue

Following cryoablation of one kidney in Strain-2 guinea-pigs, the viable opposite kidney was assessed by functional, histological and immunopathological techniques for evidence of immunologically mediated damage. The autoantibody content of postoperative sera was also examined. Control operations involved ligation, surgical nephrectomy and the production of hepatic cryolesions. The results indicate that autoantibody production and glomerular deposition of immune complexes can occur and may cause abnormal passage of hippuran through the kidney. There is no evidence for autoallergy against highly tissue-specific determinants; the specificity, strength and time course of the reactions obtained was dependent on the site of the lesion, whether or not freezing was accompanied by ligation.