High-strength graphite fibre/lithium aluminosilicate composites

Graphite fibre/lithium aluminosilicate composites of matrix composition Li₂O Al₂O₃·nSiO₂ wheren=3, 4, and 8, have been developed with a high volume fraction of undirectionally aligned graphite fibres. Graphite fibre/ceramic matrix tapes were produced on a drumwinding apparatus and hot-pressed to final dimensions. This composite system exhibits a combination of useful properties, including high strength, low density, excellent thermal shock resistance and impact strength. Shear strength, cyclic modulus of rupture and modulus of elasticity and optical and electron microscopic evaluation of microstructure are discussed. Modulus of rupture as a function of vol % fibres was studied. The high modulus of rupture and impact strength are discussed in terms of the relative properties of fibre and matrix.     

Placental peroxidase--further purification of the enzyme and oxidation of thiobenzamide

Non-Immunoglobulin Salivary Agglutinins (NIA) which directly bind to microbes [including HIV] were studied for their potential to activate the first complement component (C1). It was determined that NIA had the same specific activity as heat aggregated IgG in binding to C1q and in activating C1. In order to determine the region of C1q which bound to NIA, C1q globular heads and C1q stems (collagen-like regions) were prepared and separated via a Western blot procedure. NIA bound principally to the globular heads of C1q and weakly to the collagen-like stem region. NIA were also studied for their potential to activate native C1 in normal human serum. Heat-aggregated IgG and cardiolipin served as positive controls. It was observed that incubation of isolated NIA with fresh normal human serum resulted in the formation of sodium dodecyl sulfate (SDS)-irreversible complexes of activated C1r-C1 inhibitor and activated C1s-C1 inhibitor and in activated C1s mediated C4 conversion. This indicated that isolated NIA had the potential to directly and effectively mediate classical complement pathway activation. Preincubation of NIA with C1q, blocked NIA mediated C1r and C1s activation and C4 conversion. The concn of NIA required to activate C1r and C1s was similar to that of heat-aggregated human IgG. In kinetic ELISA, NIA or aggregated IgG (positive controls) were first immobilized on microtiter plates, blocked with gelatin then incubated with fresh human serum as a source of complement. Depositions of C4b, C3b and iC3b substantiated that the complement system was effectively activated by immobilized NIA. The optimal relative NaCl concn for C4b deposition was 0.11 M. While pre-incubation of NIA with C1q blocked the subsequent C1 fixing potential of NIA, pre-incubation of NIA with rgp160 [HIV-1] or fibronectin did not interfere with the potential of NIA to fix C1.     

Dietary risk factors for pre-eclampsia among women attending Harare Maternity Hospital, Zimbabwe

OBJECTIVE: To identify specific foods that predispose Zimbabwean women to a higher or lower risk of pre-eclampsia and/or eclampsia. DESIGN: A case control study was implemented. Participants were asked by questionnaire to recall the specific amounts of meats, poultry, fruits, fish, vegetables and dairy products they had consumed in the month prior to giving birth. SETTING: Harare Maternity Hospital, Harare, Zimbabwe between June of 1995 and April of 1996. SUBJECTS: 180 women clinically diagnosed with pre-eclampsia (144) or eclampsia (36), and 194 normotensive women without these conditions. MAIN OUTCOME MEASURES: Pre-eclampsia/eclampsia. RESULTS: There were few associations between consumption of specific food items and the occurrence of pre-eclampsia/eclampsia. Meat and fruit were the only foods found to be significantly associated with pre-eclampsia. Women who consumed 12 or more servings of meat per month were more likely to have pre-eclampsia/eclampsia when compared to women eating 11 servings of meat or less per month. While intake of bananas and mangos was unrelated to risk, women who consumed other fruits (i.e. apples, oranges, grapes, peaches, apricots, paw paw, and plums), were 1.7 (95% CI = 1.0 to 3.1) times more likely to develop pre-eclampsia/eclampsia as women who ate none of these fruits. However, women who consumed relatively large quantities of these fruits were not at a particularly high risk. Increased consumption of kapenta was modestly associated with a decrease in disease risk, but this finding was well within the limits of chance and no association was present with intake of other types of fish. CONCLUSIONS: Our findings suggest that variation in consumption of specific foods do not have a strong effect on the incidence of pre-eclampsia in this population. However, further research involving the use of a more comprehensive dietary measure, biochemical measurements of nutrients, pre-pregnancy assessment and ascertainment of dietary intake prior to the development of pre-eclampsia are needed.     

Reduction in the cumulative incidence rate of cervical cancer by one life time selective screening

PATIENT: A 35-year-old man had suffered from leukemia since September 1990. A transplantation of bone marrow was carried out in February 1994. He developed a graft-versus-host disease in November 1995. In December 1995 a keratoplasty was necessary because of a perforated corneal ulcer. 17 days later the patient noted a complete loss of vision, first in the left and one day later in the right eye. The optic nerve head was white and the retina looked ischaemic like in central retinal artery occlusion. A hypodensic area was found in the frontal brain reaching up to the optic chiasm in computer tomography. Inspite of intensive treatment the immunosuppressed patient died 4 days after he had become blind. Autopsy showed a mycotic infiltration by mucormycosis of the brain and the right optic nerve sheath. This human- pathogenic fungal infection belongs to the group of mould as well as aspergillus. CONCLUSION: Mycosis should be considered in the differential diagnosis of acute visual loss in immunosuppressed patients.     

Use of temporary bypass in surgical treatment of limbs large arteries injuries

The results of application of temporary bypass in surgical treatment of injuries of large arteries of the limbs in 40 victims are analysed. The causes of thrombosis of temporary shunt are studied its wide use is thought unreasonable. Indications for the use of temporary bypass in patients with damages of large arteries of the limbs at the stages of qualified surgical and specialised angiosurgical care are determined.     

Role of nitric oxide in the inhibition of cytochrome P450 in the liver of mice infected with Chlamydia trachomatis

In this study, we attempted to determine the effect of a systemic infection with Chlamydia trachomatis on cytochrome P450(CYP)-dependent metabolism in mice. Furthermore, we wanted to assess if these effects were mediated through NO. BALB/c(H-2d) female mice were inoculated intraperitoneally with the C. trachomatis mouse pneumonitis (MoPn) biovar, and induction of NO synthase (NOS) was detected by measuring [NOx] levels and inducible NOS protein content in peritoneal macrophages by Western blotting. Recovery of C. trachomatis from liver, lung, and spleen peaked at 4 days postinfection. Following cotreatment with N(G)-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO synthase, there was a significant increase in the intensity and the length of the infection. Six days after inoculation with C. trachomatis, CYP1A- and CYP2B-mediated metabolism in the liver of the mice was diminished up to 49% of control levels. However, when animals were treated with N(G)-nitro-L-arginine methyl ester at days 4 and 6 postinfection, the decrease in the metabolism of CYP1A and CYP2B was largely blocked. These results suggest that C. trachomatis infection can depress cytochrome P450 in a manner similar to other types of infections and that NO is likely to be a mediator of this depression. This finding may be of significance to patients taking drugs that are metabolized by phase I enzymes during infections with some bacteria such as C. trachomatis.     

Intensive medical therapy versus coronary angioplasty for suppression of myocardial ischemia in survivors of acute myocardial infarction: a prospective, randomized pilot study

BACKGROUND: Patients who have inducible ischemia after acute myocardial infarction (AMI) generally undergo coronary angiography with the intent to revascularize. Whether this approach is superior to intensive treatment with anti-ischemic medications is unknown. METHODS AND RESULTS: We performed a prospective, randomized pilot study comparing intensive medical therapy with coronary angioplasty (PTCA) for suppression of myocardial ischemia in 44 stable survivors of AMI. Myocardial ischemia was quantified with adenosine 201Tl tomography (SPECT) performed 4.5+/-2.9 days after AMI. All patients at baseline had a large total (>/=20%) and ischemic (>/=10%) left ventricular perfusion defect size (PDS). SPECT was repeated at 43+/-26 days after therapy was optimized. The total stress-induced PDS was comparably reduced with medical therapy (from 38+/-13% to 26+/-16%; P<0.0001) and PTCA (from 35+/-12% to 20+/-16%; P<0.0001). The reduction in ischemic PDS was also similar (P=NS) in both groups. Cardiac events occurred in 7 of 44 patients over 12+/-5 months. Patients who remained clinically stable had a greater reduction in ischemic PDS (-13+/-9%) than those who had a recurrent cardiac event (-5+/-7%; P<0.02). Event-free survival was superior in the 24 patients who had a significant (>/=9%) reduction in PDS (96%) compared with those who did not (65%; P=0.009). CONCLUSIONS: In this small pilot study, intensive medical therapy and PTCA were comparable at suppressing ischemia in stable patients after AMI. Sequential imaging with adenosine SPECT can track changes in PDS after anti-ischemic therapies and thereby predict subsequent outcome. Corroboration of these preliminary findings in a larger cardiac-event trial is warranted.