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Biomedical subjects

J Walls

Publications and source records attributed to J Walls.

At least 73 records · Page 4Linked to original sources
PubMed1995

Cancer awareness and self-examination practices in young men and women.

Participants in this study (N = 178) were poorly informed about risk factors, warning signs, and self-examination (SE) practices for two common cancers in young adults, testicular cancer in men and breast cancer in women. Compared to women, men were less likely to know about, see the importance of, or practice SE. We found no relationship between internal locus of control, hypochondriasis, and loneliness, on the one hand, and cancer knowledge and SE, on the other. The best predictors of cancer awareness and SE were fear of developing cancer and self-rated confidence that SE was being done correctly. The results are consistent with a health belief model and self-efficacy theory of health behavior.

Adolescent↗
PubMed1995

Peritonitis rate: traditional versus low calcium dialysate.

The results of nonrandomized retrospective studies have suggested that low calcium dialysate (LCD; ionized calcium concentration 1.25 mmol/L) is associated with a higher peritonitis rate than traditional dialysate (TD; ionized calcium concentration 1.75 mmol/L). For this reason, 86 consecutive new continuous ambulatory peritoneal dialysis patients were randomized, in a single-blind fashion, to TD or LCD for 1 year. The results were analyzed on an intention-to-treat basis, no matter what fluid or what modality of treatment was being used at the end of the year. The two groups were well matched at baseline. At 1 year, 28 of 43 TD patients were still on continuous ambulatory peritoneal dialysis (one had a catheter changed due to peritonitis), four had a working transplant, one had recovered renal function, nine had died, and one had been transferred to hemodialysis because of peritonitis. Twenty-seven of 43 LCD patients were on continuous ambulatory peritoneal dialysis (one catheter change), nine had a working transplant, six had died, and one was on hemodialysis. There were 17 proven (33 possible) peritonitis episodes in 417 patient-months in the TD group. In the LCD group, there were 17 (35 possible) episodes in 432 patient-months. The proven peritonitis rate was 0.49 episodes/patient/yr in the TD group versus 0.48 episodes/patient/yr in the LCD group (P = NS). In conclusion, there is no controlled evidence that LCD is associated with a higher incidence of peritonitis than TD.

Calcium↗
PubMed1995

Parathyroid hormone-related protein (PTHrP) in breast cancer and benign breast tissue.

Parathyroid hormone-related protein (PTHrP) 1-86 was quantified by immunoassay in extracts of 132 breast cancers, 27 samples of normal breast tissue and four fibroadenomas. PTHrP 1-86, was detected in 68% of primary tumours (range 40-302,000 fmol/g), 33% of normal breast tissues (range 100-1800 fmol/g), and all four fibroadenomas (range 110-11,600 fmol/g). PTHrP displayed molecular heterogeneity on gel filtration chromatography, and 1-86, 1-34 and 37-67 immunoreactivity eluted as 25-27 kDa together with a peak of 19-21 kDA containing only 37-67 activity. Tumour PTHrP 1-86 levels correlated inversely with age (P < 0.05) and were higher in premenopausal women (P = 0.05). The proportion of tumours containing PTHrP was higher in axillary node positive premenopausal women (P < 0.05). These data suggest that oestrogen may regulate expression of PTHrP in breast cancer and that production of PTHrP may be linked to development of axillary node metastases.

Adult↗
PubMed1995

Metabolic acidosis is a potent stimulus for cellular inorganic phosphate generation in uraemia.

1. During metabolic acidosis, significant fluxes of inorganic phosphate (Pi) may occur from cellular to extracellular fluid. In this study Pi was measured in erythrocytes of uraemic patients before and after haemodialysis and was related to their plasma pH (acidosis), plasma Pi (hyperphosphataemia) and cellular organic phosphate concentrations. 2. Before dialysis, the ratio of cellular to extracellular Pi concentration correlated inversely with plasma pH, increasing 2.5-fold as pH fell from 7.4 to 7.2. 3. An increase in cellular Pi similar to that seen in the patients was observed within 90 min of adding acid to normal erythrocytes in vitro. 4. The total Pi content of the cell suspension increased 25% on decreasing plasma pH from 7.4 to 7.2, largely as a result of generation of Pi from 2,3-bisphosphoglycerate in the cells. This was accompanied by net efflux of Pi into plasma. 5. In addition, the increase in the steady-state cellular Pi concentration on adding a constant extracellular Pi load was 50% greater at pH 7.2 than at 7.4, implying that alterations in the regulation of the transmembrane Pi gradient also contribute to the rise in cellular Pi observed at low pH. 6. At normal plasma Pi concentration (1 mM), glycolytic flux (lactate production) was inhibited by 20% when pH was lowered from 7.4 to 7.2. However, this inhibition was blocked when cellular Pi was increased by adding Pi to the plasma in vitro. 7. Metabolic acidosis is therefore a potent stimulus for Pi generation in erythrocytes, and this Pi may serve to stimulate glycolysis which is normally inhibited by low pH.

Acidosis↗
PubMed1995

Metabolic acidosis does not contribute to chronic renal injury in the rat.

1. Metabolic acidosis invariably accompanies chronic renal failure, and short periods of metabolic acidosis cause renal growth and proteinuria in normal rats. Rates of ammoniagenesis are increased in chronic renal failure, and it has been suggested that this contributes to disease progression. This study assessed (i) whether prolonged acidosis causes chronic renal injury in the normal kidney and (ii) whether abrogation of acidosis slows disease progression in the remnant kidney. 2. Metabolic acidosis was induced in normal rats by dietary hydrochloric acid. Urinary excretion of total protein, lysozyme and albumin increased, peaking at week 8 but returning to baseline by week 14. At killing after 14 weeks, kidney weights, glomerular filtration rates and serum creatinine were the same in both groups, but kidney/body weight and kidney/heart weight ratios were greater in the acidotic group. All kidneys were normal by light microscopy. 3. Rats subjected to five-sixths nephrectomy were given sufficient dietary bicarbonate to abolish uraemic acidosis, and their outcome was compared with that of non-alkalinized remnants (controls). Proteinuria, glomerular filtration rates, blood pressure, histological injury and time to the development of terminal uraemia were no better in bicarbonate-supplemented animals than in controls. 4. These data demonstrate that metabolic acidosis neither causes nor exacerbates chronic renal injury. We conclude that the treatment of uraemic acidosis is unlikely to influence disease progression in patients with chronic renal failure.

Acidosis, Renal Tubular↗
PubMed1995

c-erbB-2 oncoprotein overexpression in uterine cervix carcinoma with glandular differentiation. A frequent event but not an independent prognostic marker because it occurs late in the disease.

The c-erbB-2 proto-oncogene (HER-2/neu) codes for a transmembrane, tyrosine kinase, 185 kD oncoprotein (p185erbB2), which is related to the epidermal growth factor receptor. p185erbB2 overexpression occurs in carcinomas at many sites, including the uterine cervix, and predicts poor clinical outcome. The authors hypothesize that p185erbB2 immunohistochemistry will provide additional information in the evaluation of uterine cervix carcinomas with glandular differentiation (CCGD), a difficult and more frequent clinical problem. Paraffin sections from 82 CCGDs including 41 pure adenocarcinomas and 41 adenosquamous carcinomas (7 glassy cell predominant and 34 exhibiting a gland forming component) are immunostained with anti-p185erbB2 (CB11 monoclonal, Novacastra Laboratories, Newcastle upon Tyne, UK). Seventy-seven percent of CCGDs exhibit p185erbB2 immunoreactivity with distinct plasma membrane localization (M) in 50%, the remaining 27% show cytoplasmic staining only. Adjacent benign tissue is negative. The p185erbB2 staining intensity and distribution is as follows: 54.9% strong diffuse (SD, > or = 50% cells positive) with 40.2% M, 17.1% strong focal (SF, < 50% cells positive) with 9.8% M, and 4.9% weak with no M. Immunoreactivity occurs in both squamous and glandular areas of adenosquamous carcinomas. Endometrioid histology is associated with absence of p185erbB2 (P < .01); all other histopathologic features show no association. Follow-up information is available in 77 patients: 37 exhibit recurrent disease (8 pelvic, 15 distant and 14 both) at 1 to 144 months (mean 34, median 16) and 40 were disease free at 12 to 216 months (mean 75, median 64). Strong p185erbB2 immunoreactivity predicts recurrence at 24 months (P < .05) but not overall recurrence at longer follow-up periods. Recurrent disease is associated with nuclear grade (P < .00001); high clinical stage (P < .001); vascular space invasion (P < .001); large size on clinical exam or pathologic evaluation (P < .005); and pelvic lymph node involvement (P < .05). Considering only patients in good prognosis groups, p185erbB2 immunoreactivity does not predict recurrence. Strong p185erbB2 immunoreactivity is associated with stage 3,4 disease (P < .01). p185erbB2 expression is associated with CCGD carcinogenesis but occurs late in the disease, in patients who present at late stage, hindering its prognostic predictive value. p185erbB2 immunolocalization may have a diagnostic role in confirming CCGD in histologically challenging cases, predicting high stage at initial biopsy, and defining therapeutic strategies.

Adenocarcinoma↗
PubMed1995

Haemoglobin--is more better?

Recombinant human erythropoietin (r-HuEPO) treatment reduces cardiac output and increases left ventricular mass: beneficial effects that might be expected to be maximized at near-normal haemoglobin values. Quality of life in dialysis patients treated with r-HuEPO has been shown to be related to haemoglobin, up to a haematocrit of 35%. The potential benefits of increasing the target haemoglobin must, however, be seen in the context of the haemodynamic changes that occur during r-HuEPO treatment, in particular, increased peripheral resistance (leading to hypertension), and possible adverse effects on the coagulation system and microcirculation. Pending further trials with a target haemoglobin of 14 g/dl or a haematocrit of 40%, a target haematocrit of 34-37% seems reasonable; it might also be appropriate to adjust the target haematocrit according to the individual's symptoms and lifestyle.

Anemia↗
PubMed1995

Can preoperative factors predict for residual malignancy after breast biopsy for invasive cancer?

The presence of malignancy at the resection margins of a malignant breast biopsy requires difficult therapeutic decisions about whether a re-excision biopsy is necessary. The aim of this study was to determine the factors predisposing to the involvement of the resection margins in 280 women undergoing breast biopsy for invasive malignancy from a single breast screening practice. Resection margins were assessed independently by a single pathologist who noted either the presence of tumour at the margins of the biopsy specimen or in the shavings taken from the biopsy cavity. Resection margin involvement (RMI) occurred in 113 patients. Mammographic microcalcification (MM) was seen in 87 women with invasive cancer and RMI occurred in 53 (61%) compared with 60/193 invasive cancers without MM (P < 0.001). If RMI was present the patients underwent a second procedure to ensure complete tumour excision, and 68% of re-excision specimens from tumours with MM and 36% of tumours without MM contained residual malignancy (P < 0.005). Statistical analysis demonstrated that these observations were independent of tumour size, grade, type, and axillary node status. The presence of mammographic microcalcification therefore indicates that wider than usual surgical resection margins should be taken.

Biopsy↗
PubMed1995

Hypercalcemia and bone resorption in malignancy.

Hypercalcemia is the most common paraneoplastic syndrome associated with cancer. This paper addresses the etiology and pathogenesis of hypercalcemia of malignancy and discusses the relative contributions of local and humoral effects on bone and renal calcium homeostasis. The roles of parathyroid hormone-related protein and other osteolytic cytokines are outlined. New biochemical markers that enable more specific monitoring of the response of bone metastases to treatment are introduced, including urinary excretion of the collagen crosslinks pyridinoline and deoxypyridinoline. The clinical management and prevention of hypercalcemia is systemically outlined, including indications for bisphosphonate, glucocorticoid, and calcitonin therapy. The results of recent trials of bisphosphonate therapy for the prevention of tumor progression and its subsequent problems such as bone pain, fracture, and hypercalcemia also are discussed.

Animals↗
PubMed1995

High incidence of end-stage renal disease in Indo-Asians in the UK.

In a retrospective survey, we show that the incidence of end-stage renal disease (ESRD) is significantly raised among immigrant Indo-Asians referred to two UK renal units (p < 0.001). In addition to the expected increase in diabetic nephropathy, glomerulonephritis and chronic pyelonephritis are also seen more frequently in Indo-Asians. The most striking finding was a five-fold increase in ESRD of uncertain cause (p < 0.001) presenting with small smooth kidneys, which was strongly associated with active, mostly non-renal tuberculosis. The causes of this generalized increased susceptibility to renal disease are unknown. These findings have important implications both for primary health care screening and for planning the provision of renal replacement therapy.

Adolescent↗
PubMed1994

Regulation of intracellular creatine in erythrocytes and myoblasts: influence of uraemia and inhibition of Na,K-ATPase.

The regulation of intracellular creatine concentration in mammalian cells is poorly understood, but is thought to depend upon active sodium-linked uptake of creatine from extracellular fluid. In normal human erythrocytes, creatine influx into washed cells was inhibited by 40 per cent in the absence of extracellular sodium. In washed cells from uraemic patients, sodium-independent creatine influx was normal, whereas the sodium-dependent component of creatine influx was 3.3 times higher than normal, possibly reflecting the reduced mean age of uraemic erythrocytes. In spite of this, the intracellular creatine concentration was no higher than normal in uraemic erythrocytes, implying that some factor in uraemic plasma in vivo inhibits sodium-dependent creatine influx. Both in normal and uraemic erythrocytes, the creatine concentration was 10 times that in plasma, and the concentration in the cells showed no detectable dependence on that in plasma, suggesting that the intracellular creatine concentration is controlled by an active saturable process. Active sodium-dependent accumulation of creatine was also demonstrated in L6 rat myoblasts and was inhibited when transport was measured in the presence of 10(-4) M ouabain or digoxin, implying that uptake was driven by the transmembrane sodium gradient. However, when creatine influx was measured immediately after ouabain or digoxin had been washed away, it was higher than in control cells, suggesting that Na,K-ATPase and/or sodium-linked creatine transport are up-regulated when treated with inhibitors of Na,K-ATPase.

Adult↗
PubMed1994

Response to intravenous bisphosphonate therapy in hypercalcaemic patients with and without bone metastases: the role of parathyroid hormone-related protein.

Plasma parathyroid hormone related-protein (PTHrP) may inhibit the calcium-lowering effect of bisphosphonate therapy. In this prospective study we examined the relationship between plasma PTHrP levels, renal tubular markers of calcium reabsorption, and the effectiveness of intravenous bisphosphonate therapy (IVBPT) in lowering serum calcium in patients with hypercalcaemia of malignancy (HM), with and without bone metastases. Thirty-five symptomatic hypercalcaemic patients (17 without and 18 with bone metastases) were treated with IVBPT (pamidronate 30-60 mg or BM21.0955 2-6 mg). Normocalcaemia was achieved in 24/35 (71%) patients with a mean fall in serum calcium of 0.85 mmol l-1 (range 0.11-1.93, P < 0.001). In the 35 patients studied, serum calcium levels reached a nadir between days 3 and 7, and this was accompanied by a small but significant reduction in plasma PTHrP levels (median reduction 0.77 pmol l-1, P = 0.007). Patients who responded to bisphosphonate therapy by becoming normocalcaemic had significantly lower basal plasma PTHrP levels, mean 4.06 vs 8.2 pmol l-1 (P < 0.04). A significant reduction in urinary calcium excretion was seen (mean 106 mumol l-1, P < 0.02) in patients with bone metastases, and urinary cAMP (mean 170 mmol l-1, P < 0.01) fell in all patients. Patients without demonstrable bone metastases had significantly higher plasma PTHrP levels (P < 0.002), required more doses of IVBPT, and had a poorer reduction in serum calcium compared with patients with bone metastases, only one of whom required more than one dose. We conclude that circulating PTHrP has an important role in increasing renal tubular reabsorption of calcium in HM, thus reducing the effectiveness of bisphosphonate therapy, particularly in patients with humoral HM and no bone metastases.

Bone Neoplasms↗
PubMed1994

Parathyroid hormone and parathyroid hormone-related protein in the investigation of hypercalcaemia in two hospital populations.

BACKGROUND AND OBJECTIVE: Parathyroid hormone-related protein (PTHrP) produced by cancers has a central role as a humoral mediator of hypercalcaemia in patients with malignancy. Since the prevalences of hypercalcaemia of malignancy and parathyroid disease reflect the population studied, hypercalcaemic patients from a district general hospital (DGH) and an oncology centre (OC) were studied in order to assess the diagnostic role of assays for serum PTH and plasma PTHrP in different clinical settings. DESIGN: A prospective study of consecutive patients presenting with their first episode of hypercalcaemia during an 18-month period. PATIENTS: A total of 123 patients (DGH, n = 69; OC, n = 54) had corrected serum calcium concentrations > 2.65 mmol/l. MEASUREMENTS: PTH, PTHrP, calcium and albumin were measured together with urine calcium and creatinine, enabling fractional calcium excretion to be assessed. Urine cyclic adenosine monophosphate was also measured. RESULTS: Hypercalcaemia was attributed to malignancy alone in 72 patients (DGH, n = 20; OC, n = 52), benign causes in 42 (DGH, n = 42) and parathyroid disease coexisting with malignancy in 9 (DGH, n = 7; OC, n = 2). Plasma PTHrP levels were increased in 59/72 (82%) patients with hypercalcaemia due to malignancy. Measurements of both analytes contributed to a change in the final diagnosis in 12 patients (10%). Thus serum PTH was increased in seven patients with parathyroid disease coexisting with malignancy, and plasma PTHrP was increased in five patients with previous undiagnosed malignancy. Median survival for patients with parathyroid disease and coexisting malignancy was 13 months compared with 3 months for those with hypercalcaemia due to malignancy alone (P < 0.02). CONCLUSIONS: Since hypercalcaemia was attributable to parathyroid disease in 10% of all patients with malignancy we advise measurement of serum PTH at the initial presentation of hypercalcaemia in all patients, while plasma PTHrP may be useful to identify those patients in whom malignancy may not be clinically apparent, or coexist with primary hyperparathyroidism.

Calcium↗
PubMed1994

Influence of nifedipine on interstitial fibrosis in renal transplant allografts treated with cyclosporin A.

AIMS: To compare the degree of interstitial fibrosis in renal transplant biopsy specimens from immunosuppressed patients using conventional doses of cyclosporin with and without calcium channel blockade with a combination of low dose cyclosporin and azathioprine; to correlate the degree of interstitial fibrosis with the glomerular filtration rate. METHODS: A single blind histomorphometric assessment was done of cortical interstitial volume fraction from biopsy specimens taken intraoperatively and at one, six, and 12 months after transplantation from three prospectively randomised groups of patients: (A) conventional dose cyclosporin; (B) conventional dose cyclosporin plus nifedipine; (C) low dose cyclosporin plus azathioprine. RESULTS: Interstitial volume increased with time in all groups. No differences in interstitial volume were present at operation or at one month, but at six months interstitial volume was significantly less in group B than group A (p < 0.001) or group C (p < 0.05). More grafts failed in group A than group B leaving only small numbers for comparison at 12 months. At 12 months the differences persisted but did not reach significance. These results strongly reflected the clinical findings, where glomerular filtration rate was significantly lower in group A than groups B or C at six and 12 months; no differences in glomerular filtration rate were found at one month. In a direct comparison glomerular filtration rate showed a significant negative correlation with interstitial volume fraction. CONCLUSIONS: These findings suggest that calcium channel blockade with nifedipine slows the development of interstitial fibrosis in renal transplant recipients treated with cyclosporin. When clinical data are considered, it is suggested that calcium channel blockade may have a mitigating effect on the long term nephrotoxic effects of cyclosporin and should be considered as adjunctive treatment in patients requiring this immunosuppressant following renal transplantation.

Azathioprine↗
PubMed1994

Continuing clinically severe vitamin D deficiency in Asians in the UK (Leicester).

Deprivational vitamin D deficiency began to be noted in immigrant Asians in the early 1960s. Although there have been suggestions that the level of this problem may be declining, we describe a number of clinical cases seen over a consecutive 3 1/2 year period. Musculoskeletal symptoms were the commonest though there were a variety of medical presentations requiring hospital referral. Most of the cases were Hindu vegetarians. There is likely to be significant underdiagnosis of this condition. In spite of the extensive medical, social and political attention this condition has received, our study shows that vitamin D deficiency continues to persist in certain Asians in a clinically florid fashion. An effective preventative policy is long overdue.

25-Hydroxyvitamin D 2↗