Effects of nicotine on bacterial toxins associated with cot death

Toxins produced by staphylococci and enterobacteria isolated from the nasopharynx of cases of sudden infant death syndrome (SIDS) have a lethal effect when injected into chick embryos. If the toxins are progressively diluted the lethal effect disappears, but certain combinations of toxins show synergy so that if sublethal doses are mixed a highly lethal effect is produced. In this paper it is shown that nicotine at very low concentrations (less than that produced in man by 0.05 cigarettes) potentiates the lethal action of certain SIDS associated bacterial toxins and markedly potentiates the lethal action of synergistic combinations of bacterial toxins. These results could explain, at least in part, why parental smoking increases the risk of SIDS. They also provide further support for the common bacterial toxin hypothesis of cot death.     

A neural basis for the effect of candidate appearance on election outcomes

Election outcomes correlate with judgments based on a candidate''s visual appearance, suggesting that the attributions viewers make based on appearance, so-called thin-slice judgments, influence voting. Yet, it is not known whether the effect of appearance on voting is more strongly influenced by positive or negative attributions, nor which neural mechanisms subserve this effect. We conducted two independent brain imaging studies to address this question. In Study 1, images of losing candidates elicited greater activation in the insula and ventral anterior cingulate than images of winning candidates. Winning candidates elicited no differential activation at all. This suggests that negative attributions from appearance exert greater influence on voting than do positive. We further tested this hypothesis in Study 2 by asking a separate group of participants to judge which unfamiliar candidate in a pair looked more attractive, competent, deceitful and threatening. When negative attribution processing was enhanced (specifically, under judgment of threat), images of losing candidates again elicited greater activation in the insula and ventral anterior cingulate. Together, these findings support the view that negative attributions play a critical role in mediating the effects of appearance on voter decisions, an effect that may be of special importance when other information is absent.     

The Harvey ras 1 gene is activated in papillomavirus-associated carcinomas of the upper alimentary canal in cattle

The possible activation of ras sequences in papillomavirus-associated carcinomas of the upper alimentary canal of cattle was investigated by restriction enzyme and hybridization analysis, and by DNA-mediated transformation of NIH3T3 cells. In three cancers, a squamous cell carcinoma of the palate, a squamous cell carcinoma of the rumen, and a transitional cell carcinoma of the urinary bladder, repetitive DNA sequences present in the Ha-ras 1 locus showed anomalous restriction patterns, indicating rearrangements and, in the case of the palate cancer, amplification. Genomic DNA from several cancers was capable of inducing focus formation in the NIH3T3 transformation test. DNA from primary, secondary and tertiary transformants was analysed by hybridization to bovine ras probes and by nucleotide sequencing of polymerase chain reaction products. Bovine Ha-ras 1 sequences were found in all transformants, but no nucleotide differences were detected in exon 1 or exon 2 between normal, cancer and transformed cells. It is concluded that the Ha-ras 1 gene is activated in alimentary canal carcinomas, although the activating mutation has not yet been mapped. The possible relationship between papillomavirus infection and activation of the ras gene is considered.     

Radiographic progression of hospital referred osteoarthritis of the hip.

Various factors have been considered important in the rate of progression of osteoarthritis of the hip, though few data are available from large longitudinal studies. One hundred and thirty six patients referred to hospital (85 women, 51 men; mean age 65 years, range 29-86 years) with osteoarthritis of the hip (192 affected hips) were followed up for a median of 27 (range 3-72) months. One hundred and six patients (144 affected hips) were reviewed for a minimum of one year (median 28, range 12-72 months). Fifty three per cent of all osteoarthritic hips required an operation at a median of 14 (range 3-48) months from entry. All radiographs before and after entry were examined (median four films for each patient over a median of three years, range 0.5-19 years). Hips showing rapid radiographic progression on prospective films more often had superior migration, or an atrophic bone response; those with no progression more often had an indeterminate, medial, or axial migration pattern, protrusio or mild osteoarthritis at presentation. A higher occurrence of rapid progression was seen in women, in those of older age at symptom onset, and in hips with a higher Kellgren grade at entry; men more often showed no progression. Age at presentation, body mass index, symptom duration, or presence of chondrocalcinosis, hand osteoarthritis/nodes, or Forestier's disease did not influence progression. This study supports the contention that, at the time of hospital referral, certain patient characteristics and radiographic features at the hip may help to identify those at high risk of rapidly progressive hip osteoarthritis.     

Von Hippel-Lindau disease: an important differential diagnosis of polycystic kidney disease

Von Hippell Lindau disease is a dominantly inherited familial cancer syndrome, characterized by retinal, spinal, and cerebellar haemangioblastomas, renal cell carcinomas, and phaeochromocytomas. Cysts of the kidney and pancreas may also occur. We describe a large three-generation Irish family with VHL disease who initially presented with features typical of autosomal dominant polycystic kidney disease. Eight clinically affected individuals were found. Visceral complications were particularly prominent within the family. There were no cases of retinal angiomata or phaeochromocytoma. The diagnosis was confirmed by genetic linkage analysis in this family, although the exact mutation has yet to be defined.