Pregnancy-induced severe left ventricular systolic dysfunction in a patient with hypertrophic cardiomyopathy

This paper reports the first case of hypertrophic cardiomyopathy (HCM) that developed postpartum congestive heart failure (CHF) and severe left ventricular (LV) systolic dysfunction. Review of the literature and clinical implications are discussed.     

Helicobacter pylori and the birth cohort effect: evidence of a continuous decrease of infection rates in childhood

OBJECTIVE: To investigate whether the decrease in rate of Helicobacter pylori infection in subsequent birth cohorts has continued during the last decades. METHODS: Determination by ELISA of IgG H. pylori antibodies in 314 serum samples from Dutch children (age 6-8 yr, n = 154) and young adolescents (age 12-15 yr, n = 160), collected in 1978 and 1993. RESULTS: The prevalence of H. pylori declined from 19% to 9% at age 6-8 yr and from 23% to 11% at age 12-15 yr. For the whole study population, a decline from 21% to 10% (p = 0.01) was observed between 1978 and 1993. On the basis of these data and an incidence of infection with H. pylori of 0.3% per year during the same period, a model for both past and future prevalence rates of H. pylori in the Dutch population was calculated. The outcome demonstrates a decrease from more than 50% around World War II to less than 20% for the whole population around year 2040. CONCLUSIONS: H. pylori infection rates in childhood have continued to decline until recent decades, demonstrating a persistent birth cohort effect. This decline will result in a very low prevalence of H. pylori infection in the Dutch population during the next decades, becoming even lower as the observed decline in children and young adolescents continues.     

Ligand-specific oligomerization of T-cell receptor molecules

T cells initiate many immune responses through the interaction of their T-cell antigen receptors (TCR) with antigenic peptides bound to major histocompatibility complex (MHC) molecules. This interaction sends a biochemical signal into the T cell by a mechanism that is not clearly understood. We have used quasielastic light scattering (QELS) to show that, in the presence of MHC molecules bound to a full agonist peptide, TCR/peptide-MHC complexes oligomerize in solution to form supramolecular structures at concentrations near the dissociation constant of the binding reaction. The size of the oligomers is concentration dependent and is calculated to contain two to six ternary complexes for the concentrations tested here. This effect is specific as neither molecule forms oligomers by itself, nor were oligomers observed unless the correct peptide was bound to the MHC. These results provide direct evidence for models of T-cell signalling based on the specific assembly of multiple TCR/peptide-MHC complexes in which the degree of assembly determines the extent and qualitative nature of the transduced signal. They may also explain how T cells maintain sensitivity to antigens present in only low abundance on the antigen-presenting cell.     

Congenital microgastria: a case report and review of literature

Congenital microgastria is an uncommon result of impairment of normal foregut development. To date, only 39 cases have been described in the literature. We report a boy born with microgastria and bilateral hypoplastic kidneys who had feeding problems, resulting in failure to thrive and growth retardation. After a short period of conservative management, he was operated upon at the age of 11 months. A Hunt-Lawrence pouch was created, leading to toleration of increasing amounts of oral feeding. Although his feeding problems have decreased, his height and weight are below normal (<10th percentile). The embryology, clinical presentation, diagnostic procedures, associated anomalies, and management are discussed.     

Effect of hamstring and psoas lengthening on pelvic tilt in patients with spastic diplegic cerebral palsy

The purpose of this study was to evaluate the effects of hamstring lengthenings and psoas recessions over the brim of the pelvis (OTB) on pelvic function in the gait of patients with spastic cerebral palsy. Seventy-three patients were divided into four groups based on surgical intervention: medial hamstrings (n = 37), medial and lateral hamstrings (n = 12), medial hamstrings with psoas OTB (n = 9), and medial and lateral hamstrings with psoas OTB (n = 15). Three-dimensional gait analysis was completed both before and approximately 1 year after surgery. When pelvic position in gait was normal or posterior of normal preoperatively, there was a significant increase in pelvic tilt (p < 0.05) when medial and lateral hamstrings were lengthened, irrespective of simultaneous psoas OTB surgery. Medial hamstrings alone, with or without simultaneous psoas OTB, did not result in a significant change in pelvic position, irrespective of preoperative pelvic position. The only surgical combination that caused a reduction in excessive preoperative anterior pelvic tilt was medial and lateral hamstrings with psoas OTB, a 4 degrees change of limited clinical significance. In general, psoas and medial hamstring surgery have minimal effect on the pelvic position during gait. Medial and lateral hamstring lengthening will increase pelvic tilt if preoperative pelvic position is normal or slightly posteriorly tilted. The results of this study suggest that the fundamental determinants of pelvic position during gait postoperatively are the extent of hamstring surgery (medial only vs. both medial and lateral hamstring lengthening) and the preoperative position of the pelvis.     

Odontogenic epithelium induces similar molecular responses in chick and mouse mandibular mesenchyme

Previous observations have shown that, during the initiation phase of odontogenesis, signals from mouse odontogenic epithelium can elicit teeth in non-odontogenic but neural crest-derived mesenchyme isolated from ectopic sites including chick mandibular mesenchyme. In the present study the formation of ectopic tooth buds and dental mesenchyme in chick mandibular mesenchyme was examined using heterospecific recombinations between E11 mouse odontogenic epithelium and stage 23 chick lateral mandibular mesenchyme. Both morphological criteria and chick-specific probes for Msx-1, Msx-2, and Bmp-4 mRNAs were used as markers for early dental mesenchyme. Our results demonstrated that interactions of mouse odontogenic epithelium with chick mandibular mesenchyme induce early changes in the chick mandibular mesenchyme including the appearance of a translucent zone, cell proliferation, and induction of expression of Msx-1, Msx-2, and Bmp-4, which have been shown to be associated with the formation of dental mesenchyme. In addition, tooth bud-like structures that resemble E13 tooth buds in vivo both morphologically and in their patterns of gene expression formed after 6 days in the heterospecific recombinations. The tooth bud-like structures consist of invaginated mouse mandibular epithelium and condensed chick mandibular mesenchyme expressing high levels of Msx-1 and Bmp-4, but undetectable levels of Msx-2. Unlike the induction of Msx-1, Msx-2, and Bmp-4 in the underlying mesenchyme, which is specific for signals derived from odontogenic epithelium, the induction of a translucent zone and cellular proliferation in the underlying mesenchyme may be related to the growth-promoting potential of embryonic epithelia and not be specific to signals derived from the odontogenic epithelium. Similar to mouse odontogenic epithelium, agarose beads soaked in recombinant BMP-4 induced a translucent zone, cellular proliferation, and expression of Msx-1, Msx-2, and Bmp-4 in chick mandibular mesenchyme after 24 hours. These observations together showed that avian mandibular mesenchyme has odontogenic potential that is expressed upon interactions with inductive signals from mouse odontogenic epithelium. Similar to odontogenesis in vivo, formation of dental mesenchyme in chick mandibular mesenchyme is mediated by the activation of Msx-1, Msx-2, and Bmp-4.     

Female injecting drug users: human immunodeficiency virus risk behavior and intervention needs

The mechanism of vesication from sulfur mustard remains unknown in spite of 80 years of investigation. We recently reported sulfur mustard-related inhibition of one or more protein (serine/threonine) phosphatases in tissue cytosol in vitro, suggesting a mechanism common to other vesicants such as cantharidin and Lewisite. Our investigation showed that this inhibition was related to the concentration of 2,2'-thiobis-ethanol (thiodiglycol), the hydrolysis product of sulfur mustard, rather than to the concentration of mustard itself. Related work showed an increase in the rate of NAD (but not NADP) reduction upon the addition of thiodiglycol to mouse liver cytosol. This result provided evidence that metabolism beyond thiodiglycol may be contributing to protein phosphatase inhibition. This observation indicated that metabolism involving one or more dehydrogenases may be necessary to produce the ultimate inhibitor of the protein phosphatases. We report here that thiodiglycol is a substrate for horse liver alcohol dehydrogenase (Km = 3.68+/-0.45 mM and Vmax = 0.22 +/-0.01 micromol min(-1) mg protein(-1)) and for pyridine nucleotide-linked enzymes in mouse liver and human skin cytosol. The alcohol dehydrogenase-specific inhibitor 4-methylpyrazole inhibited the oxidation of thiodiglycol by the pure horse liver enzyme as well as by the enzymes in human skin and mouse liver cytosol, indicating that the activity in the tissue preparations is also alcohol dehydrogenase.     

The prevalence of antibiotic-resistant faecal Escherichia coli in healthy volunteers in Venezuela

Faecal samples were collected from healthy volunteers in two regions in Venezuela, the village of Grulla (n = 195) and the city of Mérida (n = 181), and analysed for the prevalence of antibiotic resistant faecal Escherichia coli as well as the antibiotic susceptibility of the strains isolated. The highest prevalences of resistance were observed for amoxicillin, oxytetracycline, sulfamethoxazole and trimethoprim. The percentages found for Grulla were 46, 38, 44 and 30%, respectively; for Mérida 39, 65, 56 and 36%, respectively. In Mérida, a significantly higher prevalence of resistance for oxytetracycline was found (P < 0.05). Significant differences in the distribution of the MIC values between Grulla and Mérida were observed for amoxicillin, chloramphenicol and oxytetracycline (P < 0.05). In Grulla, the most frequent pattern was resistance to amoxicillin only and in Mérida to oxytetracycline only. Amoxicillin resistance was due to production of TEM1 beta-lactamase.