Towards understanding the process of intestinal adaptation

When bowel is lost due to disease or surgery, the residual bowel increases its functional capacity in order to compensate for the loss of absorptive capacity. The success and extent of this adaptive process is critical to recovery. This article reviews the current understanding of the intestinal adaptation. Adaptation is a complex process which as yet is poorly understood and thus it is difficult to develop strategies to enhance the out-come of the adaptation phase. Extensive loss of bowel brings about functional as well as morphologic changes in the remaining intestine. The exact relationship between histologic changes and function is still unknown and some studies show that histologic changes may precede functional changes. Both nonnutritive and nutritive factors have been identified as major stimuli to the adaptive process. The importance of oral intake as a positive stimulus has been demonstrated and the role of diet composition rather than diet complexity being recognized. Recent studies attempt to understand the molecular basis of intestinal adaptation by seeking to characterize the nature of humoral factors involved and to establish alterations in the patterns of gene expression. These new approaches may facilitate the identification of both nutritional and pharmacological methods to manipulate the intestinal adaptation process.     

Analysis of the sex chromosomal equipment in spermatozoa of a 47,XYY male using two-colour fluorescence in-situ hybridization

The sex chromosomes in spermatozoa of a 47,XYY fertile male were analysed simultaneously by dual fluorescence in-situ hybridization (FISH), with two probes (pHY2.1 and pXBR). Of the 100000 cells analysed, 95179 spermatozoa (95.18%) exhibited one or more hybridization signals. Of the hybridized nuclei, 85.37% showed a normal sex chromosome constitution (37.37% X-bearing cells and 48.00% Y-bearing cells), with an X:Y ratio of 0.78:1. A total of 14.63% of the hybridized nuclei exhibited sex chromosome aneuploidy with a majority of XY- and YY-bearing spermatozoa (9.37 and 4.65% respectively). Even if the majority of spermatozoa have chromosomal haploidy, a large proportion of them exhibits numerical errors for the sex chromosomes. These observations raise questions about the commonly-admitted notions concerning the absence of chromosomal risk for XYY male offspring.     

Molecular definition and identification of new proteins of Mycobacterium leprae

This report describes N-terminal group analysis of six new proteins isolated from in vivo-grown Mycobacterium leprae, three of which correspond to products of the cysA, ahpC, and rpIL genes, which were recently defined through the M. leprae genome project and which encode a putative sulfate sulfurtransferase, an antioxidant enzyme, and the L7/L12 ribosomal protein, respectively.     

The deleterious effects of human erythropoietin gene driven by the rabbit whey acidic protein gene promoter in transgenic rabbits

Human erythropoietin (EPO) gene and cDNA associated with the rabbit whey acidic protein (WAP) gene promoter were used to tentatively produce the recombinant protein in milk of transgenic mice and rabbits. Several gene constructs showed good efficiency in the mouse mammary cell line HC11. None of them was able to direct the expression of the hormone at a concentration higher than 50 micrograms/mL in mouse and rabbit milk. With one of the construct, the rabbits had an abnormally high amount of red blood cells irrespectively of their sex, they could not reproduce and no milk could be obtained from them. These animals died prematurely. In these animals, the EPO gene was therefore expressed at a low but supraphysiological level in organs other than the mammary gland. These experiments show that transgenic animals obtained with gene constructs which do not contain insulators cannot be used as living fermentors to produce human erythropoietin in their milk at an industrial scale.     

Acute monoarthritis: a practical approach to assessment and treatment

A basic approach to the patient presenting with acute monoarthritis includes a careful history, a physical examination and a selected battery of laboratory tests and radiographs. Because of the possibility of septic joint, rapid assessment and treatment are required. The most common causes of acute monoarthritis are trauma, crystals (gout and pseudogout) and infection. The most important cause of acute monoarthritis is infection, which must be excluded through the use of diagnostic joint aspiration and culture of synovial fluid.     

Cytokinetic effects of cisplatin on diverse human head and neck carcinomas in vitro: dependence on the tumor sensitivity to cisplatin

Studies performed with xenografted human head and neck carcinomas in vivo have demonstrated that the cytokinetic phenomena occurring under the influence of cisplatin closely correlate with the response of the tumors to therapy. The present paper analyses whether this correlation also exists in vitro. Four human head and neck carcinoma cell lines showing different degrees of sensitivity to cisplatin, as determined by the trypan blue exclusion assay, were investigated by flow cytometry at various intervals after administration of cisplatin. Early cell-cycle blockades in the S phase always reflected a high degree of cytostatic potency of cisplatin and were usually succeeded by a pronounced inhibition of tumor cell proliferation and a reduction of cell viability. In the case of a minimal response to therapy and in untreated control cultures of all four tumor lines, the relative number of S-phase cells continuously diminished during the observation period. These findings point to the S-phase blockade as the crucial cytokinetic effect of cisplatin preceding relevant growth reductions. This knowledge might support the development of a drug-response assay that could predict the sensitivity of individual patient tumors in vitro before the beginning of clinical cancer chemotherapy.