Reconstruction of the mandible with conventional bone graft: an evaluation

Eighteen patients with bony defects of the mandible had the mandible reconstructed using conventional nonvascularized bone grafts from the iliac crest. After surgery they received radiotherapy for cancer in the oropharynx or oral cavity. This study was carried out over a 10-year period. All patients were followed-up both for their tumour growth and the results of their reconstruction. Four to 10 years after surgery 55.5 per cent were alive and well. Full dental rehabilitation was achieved in 33 percent and 12.5 percent were without dental rehabilitation.     

Percutaneous varicocele occlusion: long-term follow-up

We investigated the mechanism of resistance in murine L1210 leukaemia cells selected after treatment with FCE 23762 methoxymorpholinyl doxorubicin: (MMRDX), a methoxymorpholinyl derivative of doxorubicin active in vitro and in vivo on multidrug-resistant (mdr) cells, currently undergoing phase I clinical trials. The resistant subline obtained after repeated in vitro treatments, L1210/MMRDX, is resistant in vitro and in vivo to all tested methoxymorpholinyl derivatives and to cyanomorpholinyl doxorubicin, but shows resistance to morpholinyl derivatives only in vivo or following their activation with rat S9-liver fractions in vitro. L1210/MMRDX cells are sensitive to classic mdr- and altered topoisomerase (AT)-mdr-associated drugs. These cells do not appear to overexpress the mdr1 gene, nor do they exhibit impaired intracellular drug accumulation and efflux or altered levels of glutathione and glutathione S-transferase. The extent of DNA single-strand break formation and, after microsomal activation, of DNA interstrand cross-links after treatment with MMRDX was similar in the parent and the resistant subline. The mechanism of resistance in L1210/MMRDX cells remains to be identified but may prove a novel one, highly specific for this class of mdr-active anthracyclines.     

Partial replacement of saturated fatty acids with almonds or walnuts lowers total plasma cholesterol and low-density-lipoprotein cholesterol

Sixteen normolipidemic male volunteers aged 41 +/- 9 y (mean +/- SD) consumed a diet providing 36% of energy as fat (92 g fat/d) for 9 wk. A daily supplement of nuts (providing half of the total fat intake) was provided against a common background diet. In the first 3-wk period the background diet was supplemented with raw peanuts (50 g/d), coconut cubes (40 g/d), and a coconut confectionary bar (50 g/d), designed to provide 47 g fat with a ratio of polyunsaturated to monounsaturated to saturated fatty acids (P:M:S) to match the Australian diet (reference diet). During the following 3 wk the background diet was supplemented with monounsaturated fatty acid-rich raw almonds (84 g/d), equivalent to 46 g fat, and during the final 3-wk period the background diet was supplemented with polyunsaturated fatty acid-rich walnuts (68 g/d), equivalent to 46 g fat. Compared with the reference diet there were significant reductions in total and LDL cholesterol, 7% and 10%, respectively, after supplementation with almonds, and 5% and 9%, respectively, after supplementation with walnuts.     

Antioxidants protect podocyte foot processes in puromycin aminonucleoside-treated rats

Whether a reduction in urinary protein excretion in rats coadministered puromycin aminonucleoside and antioxidants was associated with a reduction in alterations to glomerular epithelial cell (podocyte) ultrastructure was examined. Daily urinary protein excretion was measured in rats that received a single i.v. injection of saline or puromycin aminonucleoside with or without coadministration of antioxidants. The coadministration of alpha-tocopherol/ascorbic acid, dimethyl thiourea, or superoxide dismutase to puromycin aminonucleoside-treated rats reduced proteinuria by approximately 90, 40, and 60%, respectively, over the 18-day period studied. For a second group of rats, daily urinary protein excretion was measured and kidneys were processed for light microscopy and transmission and scanning electron microscopy 4, 5, and 10 days after injection. Transmission electron microscopic morphometric analysis of glomeruli from puromycin aminonucleoside-treated rats coadministered antioxidants revealed significantly reduced foot process effacement on Days, 4, 5, and 10 compared with rats that received puromycin aminonucleoside alone. Thus, at Day 10, puromycin aminonucleoside-treated rats coadministered alpha-tocopherol/ascorbic acid, dimethyl thiourea, or superoxide dismutase contained 90, 74, and 88% (P < 0.01 in all cases) more glomerular epithelial cell filtration slits per unit length of glomerular basement membrane than rats treated with puromycin aminonucleoside alone. In contrast, by scanning electron microscopy, the antioxidants were found to provide no protection against the changes occurring in glomerular epithelial cell bodies and major processes. These results provide further evidence of a role for reactive oxygen species in puromycin aminonucleoside nephrosis and indicate that the antioxidants provide protection against the changes occurring in glomerular epithelial cell foot processes.     

Local-density studies of the structure and electronic properties of B and S in an Fe grain boundary

Previous works demonstrated that the excitatory role of serotonin (5-hydroxytryptamine, 5-HT) on ventilation is mediated by 5-HT1,2 receptors stimulation. We hypothesized that load-induced hypoventilation could be minimized by a central release of 5-HT. Conversely, blockade of 5-HT receptors should accentuate hypoventilation. We compared the ventilatory effects of methysergide (MS), a 5-HT1,2 receptors antagonist, in 3 groups of anesthetized, spontaneously breathing rabbits: (1) a group of animals breathing for 60 min through a 370 cm H2O.liter-1.s inspiratory resistive load (IRL group), whose paCO2 increased with IRL; (2) a Control group; (3) a Control + CO2 group, made hypercapnic to assess the possible effect of this stimulus on the ventilatory responses to MS. In the 3 groups, i.v. injection of MS induced the same ventilatory changes, characterized by a rapid shallow breathing with a shorter integrated diaphragmatic activity. This confirms the tonic facilitatory effect of 5-HT on ventilation and suggests that IRL would not increase 5-HT release in the sites close to the respiratory nuclei.     

The Vpu protein of human immunodeficiency virus type 1 forms cation-selective ion channels

Vpu is a small phosphorylated integral membrane protein encoded by the human immunodeficiency virus type 1 genome and found in the endoplasmic reticulum and Golgi membranes of infected cells. It has been linked to roles in virus particle budding and degradation of CD4 in the endoplasmic reticulum. However, the molecular mechanisms employed by Vpu in performance of these functions are unknown. Structural similarities between Vpu and the M2 protein of influenza A virus have raised the question of whether the two proteins are functionally analogous: M2 has been demonstrated to form cation-selective ion channels in phospholipid membranes. In this paper we provide evidence that Vpu, purified after expression in Escherichia coli, also forms ion channels in planar lipid bilayers. The channels are approximately five- to sixfold more permeable to sodium and potassium cations than to chloride or phosphate anions. A bacterial cross-feeding assay was used to demonstrate that Vpu can also form sodium-permeable channels in vivo in the E. coli plasma membrane.     

Obesity and high-density lipoprotein cholesterol in black and white 9- and 10-year-old girls: The National Heart, Lung, and Blood Institute Growth and Health Study

Acetaldehyde, the first metabolite of ethanol oxidation, has been proposed as a major initiating factor in ethanol-induced liver injury. The aims of this study were to examine whether acetaldehyde is absorbable from the digestive tract and whether, when delivered chronically in drinking water, it is capable of inducing liver injury in rats. Acetaldehyde concentrations in the rat portal and peripheral blood were measured by head space gas chromatography after intragastric (5 ml) and intracolonic (3 ml) administration of 20 mM acetaldehyde solution. In the hepatotoxicity study, rats were exposed to acetaldehyde (20 and 120 mM) delivered in drinking water for 11 weeks and histopathological changes in the liver were morphometrically assessed. Peak blood acetaldehyde levels were found at 5 min after acetaldehyde infusion and were 235 +/- 11 microM (mean +/- SE) after intragastric and 344 +/- 83 microM after intracolonic infusion of 20 mM acetaldehyde solution. The exposure of rats to 120 mM acetaldehyde solution for 11 weeks resulted in the development of fatty liver and inflammatory changes. Morphometric analysis showed significantly more fat accumulation in rats receiving 120 mM acetaldehyde solution (85 +/- 2 per cent of hepatocytes occupied by fat) than in rats receiving 20 mM acetaldehyde solution (38 +/- 11 per cent) or in controls (36 +/- 10 per cent). The dose of extrahepatic acetaldehyde (500 mg/kg per day) producing liver injury corresponds to only around 3 per cent of that derived from hepatic ethanol oxidation in animals receiving an ethanol-containing totally liquid diet (15 g/kg per day). These results indicate that acetaldehyde delivered via the digestive tract can reach the liver by the portal circulation and that acetaldehyde of extrahepatic origin appears to be more hepatotoxic than acetaldehyde formed during ethanol oxidation within the liver.     

The effect of batroxobin on coronary segmental resistance and coronary blood flow in acute myocardial ischemic dogs

To study the effects of batroxobin on coronary circulation and cardiac performance in acute myocardial ischemia, Batroxobin was given intravenously to dogs with experimental coronary stenosis. A dose-dependent increase of coronary blood flow (CBF) was observed. Forty minutes after batroxobin (2 BU.kg-1 at infusion rate 0.1 BU.kg-1.min-1) administration, CBF increased by 12% (P < 0.05), small coronary resistance(RS) decreased from 4.1 +/- 0.5 to 3.2 +/- 0.5 mmHg.min.ml-1 (P < 0.01), while large coronary resistance(RL) changed insignificantly from 3.9 +/- 0.8 to 3.8 +/- 0.7 mmHg.min.ml-1 (P > 0.05). Two hours following drug administration, the changes in CBF, RS and RL still remained and RT decreased by 13% (P < 0.05). The + LV(dp/dt)max and -LV(dp/dt)max increased by 14% and 16% (P < 0.05) respectively compared with those in control group. It is concluded that batroxobin improves the ischemic canine coronary circulation and cardiac performance by way of lowering the small coronary resistance and thus increasing CBF. The data also suggest the benificial effect of batroxobin in acute myocardial ischemia.     

Occupational asthma in a latex doll manufacturing plant

BACKGROUND: Occupational asthma caused by latex has been reported in health care workers and workers in glove manufacturing plants. OBJECTIVE: We report occupational asthma from latex in a newly identified occupational setting, a latex doll manufacturing plant. METHODS: We evaluated an index case of asthma associated with work in a latex doll manufacturing plant by performing a workplace challenge and evaluating the work environment. We then performed an occupational survey and skin testing of 22 workers in the doll manufacturing plant. RESULTS: The patient, a 21-year-old woman, had severe immediate bronchospasm within minutes of beginning a workplace challenge where sanding of latex parts was performed. Two of 22 workers surveyed (including the patient) reported flushing, rhinoconjunctivitis, and wheezing on exposure to sanded doll parts. These two workers were the only subjects surveyed to have a history of atopy and positive immediate-type skin test responses to a raw latex extract and to common aeroallergens. CONCLUSIONS: Sanding or grinding of solid latex during the manufacturing process may result in a significant incidence of occupational asthma and rhinoconjunctivitis from latex sensitization. Atopic workers appear to be most susceptible to developing latex sensitivity in this setting.     

Metabolic encephalopathies

Metabolic encephalopathies are common among patients in the critical care unit. Septic, hypoxic-ischaemic, hepatic and uraemic encephalopathies are most frequently seen. They produce global neurological dysfunctions ranging from lethargy or mild confusion to coma. Metabolic encephalopathies must be distinguished from other conditions such as structural brain lesions, infections of the central nervous system or drug reactions. Neurological manifestations are often present in the early stages of systemic illness and may be the first symptom. The severity of encephalopathy generally correlates with that of the systemic illness. Appropriate investigations often include drug and metabolic screens, cultures of blood and cerebrospinal fluids and neuro-imaging studies. Electroencephalogram is useful to grade the severity of encephalopathy. With some exceptions such as hypoxic-ischaemic encephalopathy, most metabolic encephalopathies are reversible unless secondary complications such as brain herniation occurred. Treatment is generally that of the underlying systemic illness and supportive measures.