Peripheral biomarkers and exposure to manganese.

Biochemical mechanisms underlying manganese (Mn) toxicity include dopamine (DA) auto-oxidation and free radical generation with subsequent neuronal damage. A neuroendocrine approach based on the measurement of serum prolactin (PRL) has been proposed to assess the tonic inhibition of pituitary lactotrope cells by the tubero-infundibular DA system. Low level exposure to Mn oxides in industrial settings is associated with a shift in the distribution of serum PRL towards higher levels as compared to matched controls.

Double-gracilis anorectal neosphincter: technique of reconstruction after necrosis of the distal part of the muscles.

Purpose: The aim of the present study is to demonstrate further reconstruction of a double-gracilis anorectal neosphincter that had been destroyed because of a severe postoperative perineal infection, with necrosis of the distal part of the muscles.

Method: Each residual gracilis muscle was split longitudinally into two branches, which surrounded the neorectum, one posteriorly and the other one anteriorly, so as to perform a perineorectal double sling.

Result: Owing to a poor functional result, continence was achieved only by the support of an implantable pulse generator.

Human defunctionalized colon: a histopathological and pharmacological study of muscularis propria in resection specimens.

Despite the regression of "diversion colitis," temporary functional disorders after bowel continuity restoration could be caused by changes in the smooth muscle of excluded segments; however, studies on the muscularis propria have yielded contradictory results. This study was aimed at evaluating possible histopathological changes in muscular layers and motility of the defunctionalized human colon. Ten patients with defunctionalized colorectum (group A) and 10 controls (group B) underwent restorative or primary resection surgery.

Regional sympathetic activity in pre-hypertensive phase of spontaneously hypertensive rats.

Imbalances in central and peripheral sympathetic nervous system (SNS) activity have been observed in essential and experimental hypertension. This study was carried out in order to evaluate SNS activity in two distinct tissue types of spontaneously hypertensive rats (SHR), compared to Wistar-Kyoto normotensive (WKY) rats, in the pre-hypertensive phase (4-5 weeks of age). Interstitial concentrations of norepinephrine (NE) and other catecholamines were measured by microdialysis in striated muscle, whose tone is controlled by baroreflexes, and in the subcutaneous adipose tissue where sympathetic output mainly controls metabolism.

Curative surgery for colorectal cancer: long-term results and life expectancy in the elderly.

Purpose: The long-term prognosis after curative surgery for colorectal cancer was evaluated in relation to age and life expectancy as a possible basis for assessing the risk to benefit ratios in the elderly.

Methods: Data relating to 1,256 patients operated on from 1976 to 1994 were stored in a computer database prospectively from 1987. Patients were subdivided into four age groups (A = <60 years; B = 60-69; C = 70-79; D = > or =80).

Selective vulnerability of dopaminergic systems to industrial chemicals: risk assessment of related neuroendocrine changes.

Increased serum prolactin (PRL) is a common finding among subjects exposed to styrene, perchloroethylene, lead (Pb), and manganese (Mn) at levels below the current threshold limit values. On a group basis, abnormally high basal PRL shows a dose-related distribution among workers exposed to styrene, Pb, and Mn. On the basis of dose-response relationships, the benchmark doses (BMD) for styrene metabolites in urine, lead in blood (Pb-B), and Mn in urine (Mn-U), are 4 mg/g creatinine, 112 micrograms/L, and 0.

Peripheral markers of neurochemical effects among styrene-exposed workers.

Monoamine oxidase B (MAO-B) activity in platelets, serum dopamine-beta-hydroxylase (DBH) activity, and serum prolactin (PRL) were measured during a cross-sectional investigation in workers occupationally exposed to styrene. The study group consisted of 53 workers (33 men and 20 women) employed for 9.3 years on average (range 1-22) in reinforced plastics plants.

Dopamine (DA) metabolism in PC12 cells exposed to manganese (Mn) at different oxidation states.

The present study was aimed at assessing the role of Mn valency state in Mn-induced changes in DA metabolism by PC12 cells. Mn(ll)Cl2, Mn(lll)Acetate, and Mn(IV)O2 were used for these experiments. PC12 cells were incubated for 3, 24 and 72 hours to Mn nominal concentrations ranging from 10-8 to 10(-4) M in 24-well plates containing 2 x 10(5) cells/well.

Age-related changes in interstitial norepinephrine. A microdialysis study in spontaneously hypertensive rats.

This study was aimed at evaluating the time course of interstitial norepinephrine (NE) concentrations in the white adipose tissue and at assessing NE release after local perfusion with tyramine hydrochloride (TYR) in rats of different ages. Two groups of eight spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats, aged 14 to 16 weeks, were studied. The same animals were reexamined at the age of 52 to 54 weeks.

Serum prolactin in subjects occupationally exposed to manganese.

To evaluate whether or not occupational exposure to manganese (Mn) affects basal levels of serum prolactin (PRL), a cross-sectional study was carried out in 31 occupationally-exposed workers, aged 39.2 years (DS 7.9) exposed to manganese (Mn) dusts for 14.

Effects of urinary macromolecules on the nucleation of calcium oxalate in idiopathic stone formers and healthy controls.

Urinary macromolecules have attracted great interest because of their possible role as both promoters and inhibitors of calcium oxalate (CaOx) crystallization and it remains unclear whether there is any difference, in their nucleating activity, between stone formers and controls. We selected 9 male idiopathic CaOx stone formers whose 24-h urines presented no evidence of common urinary stone risk factors such as hypercalciuria, hyperoxaluria, hyperuricosuria, hypocitraturia, hypomagnesiuria or low glycosaminoglycans excretion and 12 male controls (matched for age and body weight) whose 24-h urines did not differ from those of stone formers. The study of urinary CaOx nucleation was made in freshly voided overnight urines whose biochemical composition was almost identical in the two groups.

Quality assurance for immunochemical methods.

Recently developed immunochemical methods offer many advantages, although they may suffer from problems in standardisation due to the difficulties in the characterisation of immunological reagents. The reliability of the results is influenced by the availability of reference materials, calibrators, reagent kits and instruments. Since inter-laboratory quality control programmes have been limited by the lack of standard reference materials, laboratories using immunoassays should, at least, implement an internal quality control programme aimed at avoiding systematic errors, and adhere to the rules for good laboratory practice.

Endocrine tumours of the stomach.

This review illustrates the current classification of gastric endocrine tumors: a) carcinoid tumors (associated with chromic atrophic gastritis; with Zollinger-Ellison syndrome and multiple endocrine neoplasia type I; sporadic) and b) neuroendocrine carcinomas. The pathogenetic characteristics and clinical implications that justify this classification are discussed.

Monitoring norepinephrine levels by microdialysis in the white adipose tissue of spontaneously hypertensive rats.

1. To investigate whether microdialysis is suitable to monitor catecholamine in white adipose tissue of conscious rat and to assess eventual differences in norepinephrine (NE) interstitial levels, two groups of 12 male spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats, 14-16 weeks old, were compared. 2.

Microdialysis as a tool to assess interstitial norepinephrine levels in adipose tissue of spontaneously hypertensive rats.

The microdialysis technique was applied to the study of norepinephrine (NE) metabolism in white adipose tissue of spontaneously hypertensive (SHR, n = 6) and normotensive Wistar-Kyoto (WKY, n = 6) rats. Mean concentrations of interstitial NE were much higher in SHR as compared to WKY (mean +/- SEM: 980.9 +/- 125.

Immunological changes among workers occupationally exposed to styrene.

The functional status of the immune system was investigated in a group of 71 workers exposed to styrene and in 65 control subjects, recruited according to the same selection criteria and comparable as to sex, age, and confounding variables. Air and biological monitoring were used to characterize styrene exposure (median of the main urinary metabolites in the "next-morning" spot samples: 106 mg/g creatinine). Phenotypic analysis of peripheral blood lymphocytes (PBL) by automated flow cytometry revealed a reduced proportion of T lymphocyte subsets (CD3+, CD4+ and CD4+45+), with no changes in CD8+, and a higher proportion of B lymphocytes (CD19+) among styrene-exposed workers.

Nephropathies and exposure to perchloroethylene in dry-cleaners.

Even in specific risk groups, the relation between exposure to organic solvents and chronic renal diseases remains controversial. Thus, in a collaborative European study, we assessed the renal effects of occupational exposure to perchloroethylene (PCE) in dry-cleaners compared with matched controls who were simultaneously examined. Single high and low molecular weight proteins, kidney-derived antigens and enzymes, and prostanoids were measured in urine.

Abortive replication of influenza A viruses in HeLa 229 cells.

Several experimental data support the idea that certain mammalian cells are unable to replicate influenza viruses type A, although these viruses can efficiently penetrate the cells. This cannot be attributed to a lack of specific receptors on the cell surface, but depends upon the failure of specific step(s) to occur during viral growth. Here we report a study of abortiveness of human and avian type A influenza viruses in HeLa 229 cells.

Thyrotropin releasing hormone does not stimulate prolactin release in the preterm human fetus.

Previous studies have suggested that fetal PRL secretion does not respond to stimuli such as TRH, metoclopramide, and cimetidine. It was postulated that the lack of response to TRH could be due to the possibility that, in the term fetus, lactotropes secrete PRL maximally and would be unresponsive to further stimulation. In order to study this hypothesis, 200 micrograms TRH or saline were administered to preterm pregnant women in labor.

Relationship between blood pressure and plasma insulin in non-obese and obese non-diabetic subjects.

In this study, we have measured plasma insulin at fasting and following an oral glucose load and blood pressure after glucose load in 367 (247 non-obese, 120 obese) normotensive and untreated mildly hypertensive subjects. Overall, there was no independent association between fasting plasma insulin levels and blood pressure values. After controlling for age and body weight, a significant relationship between postglucose plasma insulin levels and diastolic blood pressure was found.

Dopaminergic regulation of fetal growth hormone (GH) secretion: study with maternal administration of bromocriptine.

To investigate the role of dopaminergic pathways on the control of growth hormone (GH) secretion, bromocriptine (BMC), a dopamine agonist drug, was orally administered at the dose of 5 mg to 46 pregnant women during labor whereas 41 received placebo. Maternal blood was obtained before drug administration and at delivery. Cord blood was obtained at delivery.