A survey into the respiratory effects of prolonged exposure to pulverised fuel ash.

Previous studies of respiratory disorders in workers exposed to pulverised fuel ash (PFA) have been confined to radiological effects that were found to be minimal. The present survey included 268 men (88% of the defined population) with a history of more than 10 years exposure to PFA in six power stations in the south east of England. Respiratory questionnaires with full occupational histories were obtained from all of these subjects, of whom 207 were actively employed and 61 had retired; 243 had lung function tests and 208 had chest x ray examinations. The men were grouped, using their occupational histories, into high, medium, and low exposure categories. Dust concentrations were obtained by personal sampling on a representative sample of men from the three exposure categories. Lung function tests showed that a modest effect on forced vital capacity, vital capacity, forced expiratory volume in one second, peak flow, and gas transfer (DCO) was associated with prolonged heavy exposure to PFA. The men with prolonged heavy exposure also showed higher prevalences of respiratory symptoms. No definite relation between exposure and x ray changes was established. The results of this cross sectional survey indicate that exposures to PFA should not exceed the limits recommended by the Health and Safety Executive for low toxicity dusts.     

Early gastric cancer: a report of 30 cases

Thirty patients with early gastric cancer have been reviewed. Endoscopy demonstrated gastric abnormality in 93% of patients examined and biopsy was accurate in 96% of cases. Twenty-nine patients were treated by partial gastrectomy, although three required further procedures. The commonest morphological type was type III (45%). Five patients with early gastric cancer had lymph node spread at the time of presentation. The relative 5-year survival rate was 68%. Four patients eventually died of gastric cancer. Three patients (10%) developed a second primary carcinoma. The significance of this diagnosis is emphasized and selective screening is considered.     

Zinc deficiency and hyperprolactinaemia are not reversible causes of sexual dysfunction in uraemia

We selected a group of male dialysis patients complaining of sexual dysfunction in whom penile vascular insufficiency and drug-induced impotence had been excluded. Monitoring of nocturnal penile tumescence was used to confirm organic disturbance. Patients with normal serum prolactin concentrations (n = 18) had significantly lower serum zinc values than normal controls (P less than 0.001) and were entered in a 6-month double-blind study comparing oral zinc acetate with placebo. Patients with elevated prolactin concentrations (n = 8) were entered in a 3-month double-blind crossover study comparing oral pergolide mesylate with placebo. In the zinc study, serum zinc concentrations increased (P less than 0.05) in the zinc-treated but not the placebo-treated group. One of nine patients receiving zinc reported improved sexual function, as did two of nine patients receiving placebo. There were no significant changes in sperm counts, nocturnal penile tumescence, testosterone, sex hormone binding globulin or gonadotrophin concentrations in either treatment group. In the pergolide study, serum prolactin values decreased (P less than 0.01) in the pergolide but not in the placebo treatment period. One patient reported improved sexual function during the pergolide treatment period and two during the placebo period. There were no significant changes in sperm counts, nocturnal penile tumescence, testosterone, sex hormone binding globulin or gonadotrophin concentrations after pergolide. These studies show no benefit of zinc or pergolide compared with placebo in the treatment of uraemic impotence.     

Biologic variation of common hematologic laboratory quantities in the elderly

Analytic, within-subject, and between-subject biologic variations were estimated for leukocytes, erythrocytes, hemoglobin, hematocrit, mean cell volume (MCV), mean cell hemoglobin (MCH), mean cell hemoglobin content (MCHC), platelets, and a three-component differential count (lymphocytes, monocytes, and granulocytes in terms of both concentration and percentage of leukocytes) in cohorts of 12 male and 12 female healthy elderly subjects. The assays were performed with an Ortho ELT-800 automated analyzer. The estimates of within-subject biologic variation were similar to published data on young subjects, indicating that this aspect of homeostasis is not compromised in the elderly. The data were used to derive objective analytic goals; goals were surpassed except for assays of erythrocytes, hematocrit, and the derived MCV, MCH, and MCHC. The changes required for serial results to be significantly different were determined and found to be generally valid because most quantities have no heterogeneity of within-subject variation. All quantities had significant individuality; in consequence, conventional population-based reference values are of limited utility, and screening using reference limits will not detect latent or early disease in many subjects.     

Osteosarcoma in young children

The clinicopathologic features of osteosarcoma in 12 children younger than 16 years of age treated at The Children's Hospital and Dana-Farber Cancer Institute, Boston, during a 70-year time period are presented. Only one of six children treated before 1972 is a long-term survivor. Four of six children (67%) treated after 1972 are disease-free with an average follow-up of 8.8 years. The year 1972 marked the onset of use of effective chemotherapy in osteosarcoma, namely, high-dose methotrexate and leucovorin rescue. It would appear that the pathologic features and behavior of osteosarcoma in young children is similar to that of osteosarcoma in older children and adolescents. A combination of complete (wide) surgical resection or amputation and aggressive chemotherapy offers the best chance of long-term survival.     

Association of diurnal variations in hypothalamic but not cortical opiate ([3H]-naloxone)-binding sites with the ability of naloxone to induce LH release in the prepubertal female rat

We report the existence of a diurnal variation in the binding of the opiate antagonist [3H]-naloxone to slices of the mediobasal hypothalamus from prepubertal female rats. The binding is highest in the early morning and reaches a nadir in the late afternoon. Opiate binding in cortical slices from such animals is constant over the course of the day. Changes in receptor density, and not in receptor affinity, account for the diurnal variation in the amount of ligand bound. These diurnal variations in receptor numbers are associated with changes in the ability of naloxone to release LH and may be crucial in the transition from the juvenile state to one of competent reproductive functioning.     

Inhibition of cytochrome P-450c-mediated benzo[a]pyrene hydroxylase and ethoxyresorufin O-deethylase by dihydrosafrole

1. Inhibitory activity of dihydrosafrole towards benzo[a]pyrene (BP) hydroxylase activity in hepatic microsomes from beta-naphthoflavone (BNF)-induced rats, and in reconstituted systems containing cytochrome P-450c, increased dramatically on preincubation of the inhibitor with NADPH; no inhibition occurred without preincubation. The level of BP hydroxylase inhibition was associated with the progressive formation of the 456 nm dihydrosafrole metabolite-cytochrome P-450c spectral complex during preincubation. 2. Inhibition of BP hydroxylase by dihydrosafrole in control microsomes, and inhibition of ethoxyresorufin O-deethylase (EROD) in microsomes (control or BNF-induced) and in reconstituted systems with cytochrome P-450c, did not require preincubation and apparently was not dependent on prior formation of the dihydrosafrole metabolite-cytochrome P-450 complex. 3. Kinetic studies established that, following preincubation with NADPH, dihydrosafrole was a noncompetitive inhibitor of both BP hydroxylase and EROD activities. In the absence of preincubation, dihydrosafrole was an effective competitive inhibitor of EROD in BNF-induced microsomes and in reconstituted systems with cytochrome P-450c. 4. Both ethoxyresorufin and benzo[a]pyrene inhibited the development of the type I optical difference spectrum of dihydrosafrole in reconstituted systems containing cytochrome P-450c. Inhibition by ethoxyresorufin was competitive while that caused by benzo[a]pyrene was noncompetitive in nature. 5. The type II ligand phenylimidazole was an effective noncompetitive inhibitor of EROD activity but failed to exert any inhibitory effect on cytochrome P-450c-mediated BP hydroxylase activity. Phenylimidazole inhibited formation of the dihydrosafrole type I optical difference spectrum non-competitively. 6. The results indicate that ethoxyresorufin and benzo[a]pyrene may occupy different binding sites on cytochrome P-450c and that dihydrosafrole binds primarily to the site utilized by ethoxyresorufin.     

荨麻疹性皮炎的定义：皮肤过敏反应模式的一种亚型

背景:荨麻疹性皮炎可能是代表一种反应模式的亚型的有用术语,病理学家通常将该反应模式命名为皮肤过敏反应。“荨麻疹性皮炎”这一术语不常用,需要定义以明确其临床相关性。目的:定义荨麻疹性皮炎并与其他荨麻疹性反应模式相鉴别,回顾皮肤科医师对荨麻疹性皮炎的临床诊断与组织