Increased hypoxemia in neonates secondary to the use of continuous positive airway pressure.

Five neonates are presented who, while receiving continuous transpulmonary pressure, developed increased systemic arterial hypoxemia, which was relieved when this therapeutic modality was decreased or discontinued. Three of the five had chest radiographs consistent with hyaline membrane disease: the other two had atypical radiographs. None had evidence of air leaks. Levels of positive airway pressure utilized when the hypoxemia was noted ranged from 5 to 15 cm H2O. Calculated shunt fractions (Qs/Qt) improved from a mean of 73% to 37% when the continuous positive airway pressure was lowered. The site of shunting in these infants could have been in the lung or through anatomic extrapulmonary shunts. Improvement in total cardiac output may also have contributed to the improved oxygenation. This paradoxical effect of continuous transpulmonary pressure appears to be mediated through changes in the pulmonary vascular resistance brought about by the continuous transpulmonary pressure.     

IMMUNOLOGICAL STUDIES IN TWO CHILDREN WITH RECURRENT PAROTITIS

ABSTRACT. In two children with recurrent parotitis, labial salivary gland biopsies showed chronic sialoadenitis. Immunofluorescence studies disclosed deposits of immunoglobulins and complement in juxta-acinar small vessels. Case 1 had gluten enteropathy, IgA deficiency and high titres of antinuclear antibodies (ANA), and in vivo fixation of ANA to nuclei of different cells in lip, skin and jejunum was present. Case 2 showed deposition of IgM in the dermo-epidermal junction of the skin. These findings suggest that autoimmune reactivity and immune complexes may play a role in the pathogenesis of this disorder.     

Ventricular tachycardia associated with transmyocardial migration of an epicardial pacing wire

A 66-year-old man who had undergone a three-vessel coronary artery bypass grafting (CABG) procedure 3 years previously presented with ventricular tachycardia (VT) and cardiac arrest. Echocardiography demonstrated a wire coursing through the right ventricle into the pulmonary artery. The wire was removed with a snare and confirmed to be an epicardial temporary pacing wire placed during the CABG operation. We suspect that the epicardial pacing wire eroded through the right atrium and migrated into the right ventricle, contributing to the VT. Complications due to temporary epicardial pacing wires placed during CABG are discussed.     

Effect of leptin on arterial thrombosis following vascular injury in mice

CONTEXT: Complications of atherosclerosis are the leading cause of morbidity and mortality in industrialized societies. Obesity has emerged as an independent risk factor for complications of atherosclerotic vascular disease. Leptin, a hormone produced by the adipocyte, increases with obesity and appears to modulate energy balance and food intake. In addition, other actions of leptin have been proposed, including an in vitro effect on platelet aggregation. Thus, the elevated plasma leptin levels in obese individuals may promote vascular thrombosis. OBJECTIVE: To test the hypothesis that leptin contributes to in vivo thrombosis via the leptin receptor. DESIGN AND MATERIALS: Between September 2000 and September 2001, a vascular thrombosis model was used to test male 10- to 12-week-old mice completely deficient in leptin or the leptin receptor and mice with platelet leptin-receptor deficiency. MAIN OUTCOME MEASURE: Time to formation of an occlusive thrombus in the common carotid artery following experimentally induced endothelial injury. RESULTS: Following onset of vascular injury, wild-type mice (n = 8) formed occlusive thrombosis in a mean (SD) of 42.2 (4.6) minutes, whereas leptin-deficient (n = 5) and leptin receptor-deficient mice (n = 7) formed occlusive thrombosis in 75.2 (10.1) and 68.6 (10.3) minutes, respectively (leptin deficient vs wild-type mice, P =.008; leptin-receptor-deficient vs wild-type, P =.03). When recombinant murine leptin was administered to leptin-deficient mice (n = 4), the time to occlusion was reduced to 41.8 (6.6) minutes (P =.035 vs vehicle control). Following bone marrow transplantation from leptin receptor-deficient (donor) mice to wild-type (recipient) mice, the time to occlusion was prolonged from 22.3 (2.8) minutes in wild-type mice receiving wild-type marrow (n = 3) to 56.8 (5.0) minutes in wild-type mice receiving leptin receptor-deficient bone marrow (n = 5) (P =.003). CONCLUSIONS: Leptin contributes to arterial thrombosis following vascular injury in vivo and these prothrombotic effects appear to be mediated through the platelet leptin receptor.     

Close mapping of the focal non-epidermolytic palmoplantar keratoderma (PPK) locus associated with oesophageal cancer (TOC)

Focal non-epidermolytic palmoplantar keratoderma (PPK or palmoplantar ectodermal dysplasia type III) is associated with oesophageal cancer in three families: two large pedigrees located in Liverpool, UK and in the midwestern American states and one smaller family from Germany. In these families, the PPK is inherited as autosomal dominant and has a late onset, usually manifesting between 7 and 8 years of age. The disease is characterised by thickening of the pressure areas of the soles, but is not restricted to the feet and also presents with oral leukokeratosis and follicular hyperkeratosis. The disease locus [previously termed the "tylosis oesophageal cancer gene' (TOC) locus] has been mapped to 17q23-qter by linkage analysis. This region is located telomeric to the keratin 16 gene, in which mutations have been identified in focal PPK families who show no increased cancer risk. We describe the close mapping of this locus to the interval between AFMb054zf9 and D17S1603 using haplotype analysis of additional Genethon markers in the region and show that although the American family is unlikely to be related to either of the other two, the UK and German pedigrees may share a common descent. This work provides a basis for positional cloning and candidate gene analysis in order to identify a gene that may be involved in familial oesophageal cancer.      

A New Retrieval System for Cement-Retained Implant Superstructures: A Technical Report

This article discusses two methods for improving the retrievability of cement-retained implant superstructures. One method involves incorporating a removal screw in the superstructure and the second method uses a small dimple on the abutment, accessed through a vent in the superstructure.     

Incipient ovarian failure associated with raised levels of follicle stimulating hormone and reduced levels of inhibin A in older sheep

In women there is a gradual rise in the basal level of follicle stimulating hormone (FSH) in the years prior to the menopause (pre- menopause) which is thought to be due to a relative lack of ovarian factors reflecting the number of antral follicles present in the ovaries. Experimental animal models for this phenomenon, particularly in mono-ovulatory species, have been lacking due to most animals' relatively short life span. We have available a group of experimental ewes in which the right ovary was removed and the left ovary was autotransplanted to the neck at least 10 years previously, which have been maintained in good health until an age of 12-13 years. Two experiments were conducted with these animals to determine the endocrine and follicular effects of age: a retrospective experiment in the same Finn-Merino ewes (n = 5) when the animals were 6-7 or 12-13 years of age; and a cohort experiment in old (12-13 years, n = 6) and young (2 years, n = 5) ewes of the same breed. In both retrospective and cohort experiments, the concentrations of FSH were significantly higher (P < 0.05) in older animals during the luteal phase when oestradiol secretion was low. This increase in FSH was associated with a decrease in the concentration of inhibin A (P < 0.05) in older animals in both the follicular and luteal stages of the cycle but the concentrations of oestradiol were similar between ages. Although there were significantly fewer antral follicles (P < 0.05) available for development in older ewes during the early luteal phase of the cycle, the ovulation rate was similar to that observed in younger animals (2.0+/-0 vs 2.0+/-4; P > 0.05) but the interval from luteal regression to the onset of the LH surge was longer (P < 0.05) in older animals. In conclusion, the endocrine changes associated with increasing reproductive age in sheep are therefore similar to those observed in women, suggesting that the sheep could be a useful animal model to study the effect of age on human fertility.      

International Salmonella Typhimurium DT104 infections, 1992-2001

The incidence of multidrug-resistant (MDR) Salmonella Typhimurium infections in humans, and in particular MDR definitive phage type 104 (DT104), has increased substantially in many countries in the last 2 decades, often associated with increased illness. To examine the magnitude of this problem, a survey was conducted among countries with available antimicrobial resistance or phage typing surveillance data. A total of 29, primarily industrialized, countries participated in the survey, which covered the years 1992-2001. Overall, the incidence of MDR S. Typhimurium and DT104 increased continuously during this period, although the problem affected primarily Europe and North America. The increase appeared to have peaked in the United Kingdom but not in other countries. Also, the incidence of quinolone-resistant S. Typhimurium was increasing. This survey implies that MDR S. Typhimurium constitutes an increasing public health problem in large parts of the world and emphasizes the importance of surveillance and control programs.     

Cytotoxicity as an indicator for transport mechanism: evidence that murine bone marrow progenitor cells lack a high-affinity leucine carrier that transports melphalan in murine L1210 leukemia cells

Cytotoxicity of melphalan to murine L1210 leukemia cells was reduced to a limiting maximum value of 50% by 2-aminobicyclo[2,2,1]heptane-2- carboxylic acid (BCH), indicating that cytotoxicity is partially dependent on drug uptake by system L. L-Leucine, but not alpha- aminoisobutyric acid (AIB), completely reduced the remaining 50% of drug cytotoxicity. These results contrast with those obtained with a sensitive host tissue, the bone marow progenitor cells of the white cell series (CFU-C), in that a high-affinity leucine transport system corresponding to system L was not identified.