Racial differences in intact erythrocyte ion transport

Epidemiologic studies indicate a much higher incidence of hypertension in blacks than in whites, although no clear biochemical correlates to account for such overt racial differences have been identified. In recent years, considerable evidence has linked perturbations in ion transport to the risk of developing hypertension. Potassium (K+) transport and the ouabain-sensitive component of K+ transport in the erythrocyte were measured in 54 healthy, age and sex matched black and white subjects. Blacks have a significantly (p less than 0.001) lower capacity for K+ transport (0.190 +/- 0.03 mumoles K+ per hr per 10(9) red blood cells [RBC] than whites (0.230 +/- 0.03 mumoles K+ per hr 10(9) RBC) with a significantly (p less than 0.001) higher percentage of K+ transport dependent upon ouabain-sensitive mechanisms (blacks 85.26 +/- 4.14 percent versus whites 76.69 +/- 6.67 percent). These data clearly define overt racial differences in K+ transport which suggest that blacks have a more limited capacity to exchange intracellular sodium for extracellular K+, and a higher percentage of that exchange is dependent upon ouabain-sensitive mechanisms. These findings need be kept in mind were clinical studies of ion transport are being assessed and may be germane to the increased prevalence in blacks for the development of hypertension.     

Comparison of digital systems and conventional dental film for the detection of approximal enamel caries

Objectives

The aims of this study were (1) to compare the accuracy of the detection of approximal enamel caries lesions using three intraoral storage phosphor plate digital systems and one conventional film-based radiographic system; and (2) to determine whether there is a correlation between the histological and radiographic measurements of enamel caries.

Methods

160 approximal surfaces were radiographed under standardized conditions using three storage phosphor stimulable systems (DenOptix and Digora FMX with white and blue plates), and one film system (Insight film). 17 observers scored the images for the presence and depth of caries using a 4-point scale. The presence of caries was validated histologically (gold standard). Two-way analysis of variance was used to test the differences in sensitivity, specificity and overall accuracy (TP + TN). The data from the radiographic and histological measurements were statistically analysed by Spearman’s rank correlation coefficient.

Results

Two-way analysis of variance and the post hoc t-test demonstrated that Digora (white plate) had higher specificity and overall accuracy values than DenOptix (P = 0.021); there was no statistically significant difference among the other imaging modalities (P > 0.05). There was no significant correlation between the histological depth measurements and the radiographic measurements from Digora (blue plate) (P = 0.43), Digora (white plate) (P = 0.15), DenOptix (P = 0.17) and Insight film (P = 0.06).

Conclusions

The results suggest that (1) the performance of the three storage phosphor image plate systems was similar to that of the Insight film for detection of approximal enamel caries, and (2) the increase in histological depth of enamel caries was not significantly correlated with radiographic measurements.     

An analysis of eccentric photo refraction

The optics of eccentric photo refraction are analysed. The variation of photo refractive lunula area with refractive error, pupil size, flash eccentricity and camera aperture were calculated using a model eye. Measurements from photographs of paraxial (eccentric) photo refraction of model eyes show that a good agreement exists between theory and experiment over a range of refractive errors from — 10 D to +10 D. Calculations were also made for a standard reduced eye. The optimal set-up for measuring refractive error accurately over a wide range of refractive states is discussed, as are the problems which arise from non-central fixation.     

Node negative breast cancer: the prognostic value of DNA ploidy for long-term survival.

The DNA content of breast tumours from 170 patients who presented between 1978 and 1980 was measured by flow cytometry. The relationship between tumour ploidy and disease outcome was assessed and its association with other prognostic factors evaluated. Compared with those with diploid tumours, patients with aneuploid tumours had significantly earlier relapse and shorter survival (P less than 0.0001). Tumour ploidy was strongly related to grade (P less than 0.001), but there was no significant association between DNA ploidy and c-erb-B-2 expression, lymph node status or tumour size. In lymph node negative and c-erb-B-2 negative patients, aneuploid tumours were associated with a poorer prognosis (P less than 0.001) than diploid tumours. Multivariate analysis showed that tumour ploidy gave independent information on disease free and overall survival. Tumour ploidy may be used as an independent prognostic variable in patients with breast cancer and it may be helpful in defining patients within the node negative or c-erb-B-2 negative groups likely to have a poor outcome who might benefit from adjuvant treatment.     

The effect of menopause and hysterectomy on systemic vascular endothelial growth factor in women undergoing surgery for breast cancer

Background  

Vascular endothelial growth factor (VEGF) is a potent angiogenic cytokine produced physiologically by the uterus. Pathological secretion by tumours promotes growth and metastasis. High circulating VEGF levels potentially have a deleterious effect on breast cancer by promoting disease progression.     

Chylothorax after oesophagectomy

Chylothorax is an uncommon complication of oesophagectomy. In a review of 537 oesophageal resections there were 11 cases of chylothorax, an incidence of 2.0 per cent. There was no correlation with site, size, penetration, lymph node status, length or type of tumour but there was a significant correlation between chylothorax and the type of operative procedure carried out. The incidence in 95 transhiatal resections was 10.5 per cent. The incidence following 442 transthoracic procedures was 0.2 per cent (P less than 0.001) with one chylous fistula occurring after a three-stage oesophagectomy. Initial management was conservative with chest drainage and total parenteral nutrition. Thoracotomy and duct ligation was subsequently carried out in three patients and was successful in two. The third patient died. Conservative management alone was successful in four out of eight patients, with closure of the fistula at a median of 35 days (range 14-42 days). Four patients treated conservatively died. Transhiatal oesophagectomy greatly increases the risk of chylothorax, a condition that carries a high mortality rate (46 per cent in this series) whether managed conservatively or by surgical intervention.     

NCL-CB11, a new monoclonal antibody recognizing the internal domain of the c-erbB-2 oncogene protein effective for use on formalin-fixed, paraffin-embedded tissue

The c-erbB-2 proto-oncogene encodes a 190 k Mr protein representing a putative growth factor receptor with considerable homology to the EGF receptor. Gene amplification and overexpression of the oncogene protein have been demonstrated in a variety of tumours including breast cancer, where it is associated with a poor prognosis. In this study we have produced and characterized a mouse monoclonal antibody, designated NCL-CB11, to the c-erbB-2 protein. NCL-CB11 was generated to a synthetic peptide sequence corresponding to a site of predicted antigenicity near the C-terminus of the internal domain of the protein. NCL-CB11 produces intense membrane-associated immunohistochemical staining in a proportion of human cancer cells. The specificity of the antibody is supported by Western blotting and immunoprecipitation studies. Reactivity with an internal site of the protein is confirmed by the necessity of cell permeabilization for reactivity in fluorescence-activated cell sorter (FACS) analysis. A high degree of correlation between immunohistochemical staining using NCL-CB11, and c-erbB-2 gene amplification has been observed. NCL-CB11 should prove to be a valuable reagent for investigations into the pathological significance of c-erbB-2 protein expression.     

Campylobacter pyloridis and gastritis: association with intercellular spaces and adaptation to an environment of mucus as important factors in colonization of the gastric epithelium

Stomach biopsy specimens from greater than 40 individuals with Campylobacter pyloridis-associated gastritis were examined by light and electron microscopy. The bacteria were consistently seen in two locations: within the gastric mucus and associated with intercellular junctions of gastric epithelial cells. C. pyloridis is suggested to be one of a broad group of spiral bacteria that are adapted to the peculiar niche provided by intestinal mucus. The spiral morphology and the form of motility of these organisms give them a selective advantage in a viscous environment. This point has been demonstrated in vitro by measurement of the velocity of clinical isolates in solutions of methyl cellulose of varying viscosity. The localization of C. pyloridis close to intercellular junctions is proposed to be due to the presence of preferred metabolites or growth factors, e.g., urea and hemin. All isolates show an extremely high urease activity and require hemin for growth.