Genetic analysis of new restriction fragment length polymorphisms (RFLP) in the human IgH constant gene locus

The human immunoglobulin heavy chain constant gene locus (IGHC) is polymorphic at both the protein (Gm and A2m allotypes) and the DNA level [RFLP for the gamma genes (IGHG), the switch mu region (IGHSM) and the switch alpha regions (IGHSA)]. The polymorphisms have been a valuable tool for assessment of the IGHC locus organization and a variety of population genetics and immunological investigations. In this study three new probes, identifying regions related to the IGHG (IGHPG and IGHSG) or IGHA (IGHAT) genes, have been employed to describe 11 different loci, 6 of which were polymorphic. Most of the polymorphisms are probably due to short insertions/deletions, particularly the SG regions, due to their repetitive structure. Ten loci were assigned to the IGHC region on the basis of known restriction maps, deletion mapping and association with mapped RFLP; the 11th, despite a striking sequence similarity with the IGHPG regions, could not be assigned to any known IGHC subregion. Analysis of these and previously known IGHG RFLP in a sample of 65 unrelated subjects plus 15 families allowed us to draw a genetic map, with particularly high resolution in the GP-G2-G4 genes region, revealing a marked discontinuity in the linkage disequilibrium values between pairs of adjacent loci.     

Expression cloning of a human dual-specificity phosphatase.

Using an expression cloning strategy, we isolated a cDNA encoding a human protein-tyrosine-phosphatase. Bacteria expressing the kinase domain of the keratinocyte growth factor receptor (bek/fibroblast growth factor receptor 2) were infected with a fibroblast cDNA library in a phagemid prokaryotic expression vector and screened with a monoclonal anti-phosphotyrosine antibody. Among several clones showing decreased anti-phosphotyrosine recognition, one displayed phosphatase activity toward the kinase in vitro. The 4.1-kilobase cDNA encoded a deduced protein of 185 amino acids with limited sequence similarity to the vaccinia virus phosphatase VH1. The purified recombinant protein dephosphorylated several activated growth factor receptors, as well as serine-phosphorylated casein, in vitro. Both serine and tyrosine phosphatase activities were completely abolished by mutagenesis of a single cysteine residue conserved in VH1 and the VH1-related (VHR) human protein. These properties suggest that VHR is capable of regulating intracellular events mediated by both tyrosine and serine phosphorylation.     

Abnormal development of Purkinje cells and lymphocytes in Atm mutant mice

Motor incoordination, immune deficiencies, and an increased risk of cancer are the characteristic features of the hereditary disease ataxia-telangiectasia (A-T), which is caused by mutations in the ATM gene. Through gene targeting, we have generated a line of Atm mutant mice, Atm(y/y) mice. In contrast to other Atm mutant mice, Atm(y/y) mice show a lower incidence of thymic lymphoma and survive beyond a few months of age. Atm(y/y) mice exhibit deficits in motor learning indicative of cerebellar dysfunction. Even though we found no gross cerebellar degeneration in older Atm(y/y) animals, ectopic and abnormally differentiated Purkinje cells were apparent in mutant mice of all ages. These findings establish that some neuropathological abnormalities seen in A-T patients also are present in Atm mutant mice. In addition, we report a previously unrecognized effect of Atm deficiency on development or maintenance of CD4(+)8(+) thymocytes. We discuss these findings in the context of the hypothesis that abnormal development of Purkinje cells and lymphocytes contributes to the pathogenesis of A-T.     

Short-term strength training improves muscle quality and functional capacity of elderly women

To assess effects of a short-term strength training (ST) program on muscle quality (MQ) and functional capacity, 36 sedentary elderly women (age = 66.0 ± 8 year, height = 159.1 ± 9.2 cm, body mass = 68.3 ± 12.1 kg, body fat = 37.0 ± 4.2 %) were randomly divided into an experimental group (EG; n = 19) or a control group (CG; n = 17). The EG performed two to three sets of 12–15 repeats of leg press, knee extension, and knee flexion exercises, 2 days/week for 6 weeks. Before and after training, lower body one repetition maximum (1RM), functional performance tests, quadriceps femoris muscle thickness (MT), and muscle quality (MQ) (1RM and quadriceps MT quotient) were assessed. After training, only the EG showed significant improvements in 1RM (p < 0.05), 30-s sit-to-stand (p < 0.001), and 8 foot up-and-go (p < 0.001). In addition, only in the EG, significant increases in all quadriceps femoris MT measurements (vastus lateralis, vastus medialis, vastus intermedius, and rectus femoris) (p ≤ 0.05), and MQ (p < 0.001) were demonstrated. No changes were observed in the CG. Furthermore, there were significant associations between individual changes in MQ and corresponding changes in 30-s sit-to-stand (r = 0.62, p < 0.001), and 8 foot up-and-go (r = −0.71, p < 0.001). In conclusion, a ST program of only 6 weeks was sufficient to enhance MQ of the knee extensors in elderly women, which resulted in beneficial changes in functional capacity.     

Abnormal linear growth in paediatric adrenal diseases: Pathogenesis,prevalence and management

Abnormal adrenal function can interfere with linear growth, potentially causing either acceleration or impairment of growth in paediatric patients. These abnormalities can be caused by direct effects of adrenal hormones, particularly glucocorticoids and sex steroids, or be mediated by indirect mechanisms such as the disturbance of the growth hormone-insulin-like growth factor-1 axis and aromatization of androgens to oestrogens. The early diagnosis and optimal treatment of adrenal disorders can prevent or minimize growth disturbance and facilitate improved height gain. Mechanisms of growth disturbance in the following abnormal states will be discussed; hypercortisolaemia, hyperandrogenaemia and obesity. Prevalence and features of growth disturbance will be discussed in ACTH-dependent and ACTH-independent Cushing's syndrome, adrenocortical tumours, premature adrenarche, congenital adrenal hyperplasia and adrenal insufficiency disorders. Recommendations for management have been included.     

Treatment of inguinal hernia: a prospective study comparing Bassini's procedure,the inguinal pre-peritoneal prosthesis and the Lichtenstein technique

Inguinal hernia surgery has aroused considerable interest in recent years, with numerous advances being proposed to treat these disorders. Bassini's procedure, based on the importance of the transversalis fascia as a fundamental containment mechanism, was for many years the treatment of choice for inguinal hernia. In our study, covering eight years of activity, we focused our attention on this principle, comparing repair procedures such as Bassini's and those with a preperitoneal mesh, in which the repair involves the transversalis fascia, with procedures based on Lichtenstein's technique in which the fascia is left intact. The investigation protocol was thus based on the performance of the three techniques in parallel by the same surgical team. The parameters of immediate complications, lasting pain and recurrence were used to evaluate the results. The first two occurred infrequently in all groups (a greater incidence was seen with mesh procedures). Recurrence rates after preperitoneal mesh techniques were extremely low, confirming the paramount functional importance of the transversalis fascia. The results of our analysis substantiate the advantage of employing the preperitoneal mesh technique, which opens up new horizons for the treatment of recurrent hernia.     

Reactivation of CMV retinitis after treatment with subtenon corticosteroids for immune recovery uveitis in a patient with AIDS

We present the case of an HIV-infected patient who developed reactivation of CMV retinitis after a local steroid injection for the treatment of immune recovery uveitis. He responded promptly to reinduction with ganciclovir and recovered. To our knowledge this is the first case of CMV retinitis reactivation in an HIV-infected patient receiving steroids for immune recovery uveitis.     

The coeliac iceberg in Italy. A multicentre antigliadin antibodies screening for coeliac disease in school-age subjects

Background : Recent studies suggest that coeliac disease (CD) is one of the commonest, life-long disorders in Italy. The aims of this multicentre work were: (a) to establish the prevalence of CD on a nationwide basis; and (b) to characterize the CD clinical spectrum in Italy. Patients and methods : Fifteen centres screened 17201 students aged 6–15 years (68.6% of the eligible population) by the combined determination of serum IgG- and IgA-antigliadin antibody (AGA) test; 1289 (7.5%) were IgG and/or IgA-AGA positive and were recalled for the second-level investigation; 111 of them met the criteria for the intestinal biopsy: IgA-AGA positivity and/or AEA positivity or IgG-AGA positivity plus serum IgA deficiency. Results : Intestinal biopsy was performed on 98 of the 111 subjects. CD was diagnosed in 82 subjects (75 biopsy proven, 7 not biopsied but with associated AGA and AEA positivity). Most of the screening-detected coeliac patients showed low-grade intensity illness often associated with decreased psychophysical well-being. There were two AEA negative cases with associated CD and IgA deficiency. The prevalence of undiagnosed CD was 4.77 × 1000 (95% CI 3.79–5.91), 1 in 210 subjects. The overall prevalence of CD, including known CD cases, was 5.44 × 1000 (95% CI 4.57–6.44), 1 in 184 subjects. The ratio of known to undiagnosed CD cases was 1 in 7. Conclusions : These findings confirm that, in Italy, CD is one of the most common chronic disorders showing a wide and heterogeneous clinical spectrum. Most CD cases remain undiagnosed unless actively searched.     

Increasing incidence of childhood celiac disease in Sicily: results of a multicenter study

By screening the patient list of four Sicilian centers of gastroenterology and those with gluten-free product consumption, 1074 patients (607 females and 467 males) with celiac disease, diagnosed between 1975 and 1989, were identified. A maximum cumulative incidence rate by birth cohort was reached in 1986 (1.65/1000). When the incidence rate was adjusted for the years of follow-up, the actual standardized rate was 3 cases per 1000 live births. Growth failure and chronic diarrhea were the most common symptoms, but a diminishing trend for chronic diarrhea was observed when symptoms were distributed by year of diagnosis. Even though 61.1% of all cases were diagnosed within six months from the onset of symptoms, mean age at diagnosis showed an increasing trend, from less than two years to approximately four years of age. The results of our study showed an increasing incidence of celiac disease due to diagnosis of less typical cases at an older age and also to a steady increase in the rate of diagnosis of cases with a classic clinical picture.     

Neu differentiation factor/heregulin induction by hepatocyte and keratinocyte growth factors

Hepatocyte growth-factor (HGF) is a potent, widely produced, pleiotropic mediator of mesenchymal-epithelial interaction. In a study of changes in gene expression initiated by HGF in Balb/MK keratinocytes, we observed the induction of Neu-differentiation factor (NDF) mRNA (also known as heregulin, or HRG). Further characterization of the regulation of NDF expression in Balb/MK keratinocytes revealed potent induction by keratinocyte growth factor (KGF) and epidermal growth factor (EGF), but not by HGF/NK2, an alternative HGF isoform with motogenic but not mitogenic or morphogenic activities. Sustained treatment (8 h) of Balb/MK cells with KGF stimulated secretion of mature NDF protein into the culture medium, and Balb/ MK cells treated with purified recombinant NDF protein showed increased DNA synthesis. We also found evidence of NDF induction in two models of tissue repair in mice: in full-thickness skin wounds, following locally increased KGF production, and in kidney after partial hepatectomy, following elevation of circulating HGF levels. These results reveal that mesenchymally-derived HGF and KGF can activate autocrine NDF signaling in their epithelial targets, and suggest that this mechanism contributes to the coordination of stages of wound repair, and possibly development, where these growth factors act in concert to direct epithelial proliferation, morphogenesis and differentiation.