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Biomedical subjects

E F Schneider

Publications and source records attributed to E F Schneider.

18 recordsLinked to original sources
PubMed1994

Preeclampsia: progress and puzzle.

Preeclampsia is a major cause of maternal and fetal morbidity and mortality. It remains a management challenge despite recent advances in the understanding of the pathophysiology of this condition and its prevention, and it remains a major cause of maternal and fetal morbidity and mortality. The hallmarks of preeclampsia are proteinuria and edema in a woman who is hypertensive. Current theories suggest altered prostaglandin synthesis, inappropriate sensitivity to angiotensin II and immunologic factors as etiologies of preeclampsia. Low-dose aspirin therapy and high-dose calcium supplementation show promise in preventing preeclampsia and reducing its severity when it occurs. However, aggressive antenatal maternal and fetal assessment, magnesium sulfate therapy and early delivery are the standards of preeclampsia management.

Diagnosis, Differential↗
PubMed1993

The aseptic meningitis syndrome.

The diagnosis and treatment of acute meningitis is a challenge for the primary care physician. Differentiating between bacterial meningitis and aseptic meningitis is not always straightforward. The aseptic meningitis syndrome is usually viral in origin, and enteroviruses account for most cases. The aseptic syndrome also may be caused by unusual bacterial organisms such as Mycobacterium tuberculosis, Leptospira species, Brucella species, Borrelia burgdorferi and others. The classic presentation consists of the acute onset of meningismus, headache, fever, malaise with pleocytosis and normal glucose and slightly elevated protein in the cerebrospinal fluid. Cerebrospinal fluid lactate and serum C-reactive protein measurements may be helpful in differentiating aseptic meningitis from treatable bacterial meningitis. Aseptic meningitis of viral origin usually responds to expectant care. Other causes of aseptic meningitis must be searched for and treated if present.

Clinical Protocols↗
PubMed1979

Ultrastructural studies on the cell walls in Fusarium sulphureum.

The cell walls of Fusarium sulphureum have a microfibrillar component that is randomly arranged. X-ray-diffraction diagrams of the microfibrils are consistent with a high degree of crystallinity and show that they are chitin. The chitin microfibrils of the peripheral walls envelop the hyphal apex and extend across the septae. During the first 8h in culture, the conversion of conidial cells to chlamydospores is evidenced by a swelling of the cells and the original microfibrils remain randomly arranged. Within 24h new wall material is deposited as the cells expand and the wall thickens. The new microfibrils are indistinguishable from those of the original conidial cells. After 3 days in culture, the chlamydospores are fully developed and have the characteristic thick wall which is a continuous layer of randomly arranged microfibrils. Chlamydospores maintained in a conversion medium for 8 days have microfibrils identical with those in 3-day-old cultures; thus a further change in the microfibril orientation did not occur during that period. Alkaline hydrolysis of the walls removes most of the electron-dense staining constituents from the inner wall layer and leaves the outer wall layer intact. This treatment also reveals some of the wall microfibrils. An additional treatment of the walls with HAc/H2O2 completely removes the wall components that react positively to heavy metal stains. The results are discussed in relation to the structure of other fungal cell walls.

Cell Wall↗
PubMed1979

Effect of thiols on macroconidia of Fusarium sulphureum.

Treatment of Fusarium sulphureum macroconidial cells with five thiols alters their morphology. Macroconidial cells incubated in dithiothreitol (DTT), dithioerythritol (DTE), or thiourea differentiate into thick-walled, chlamydospore-like cells (thiol-induced spores). These cells appear similar in size and shape to chlamydospores in the light microscope, but differ markedly in cell wall structure when viewed in the electron microscope (EM). Incubation of macroconidia with both DTT and DTE also leads to the formation of large swollen cells (giant cells) which have a parietal cytoplasm and electron-tranparent cell walls; most of these giant cells lyse within 3 to 7 days of incubation. Thiourea-induced spores are characterized by the deposition of a thick, electron-dense, extracellular layer and an accumulation of mitochondria. DTT and DTE, at the concentrations used, inhibit macroconidial germination while thiourea, mercaptoethanol, and cysteine do not. With the latter three thiols, the newly formed hyphal cells become elongated with either one or both ends swollen. Mercaptoethanol-treated cells contain an abundance of mitochondria. The DTT-induced spore differs from both macroconidia and chlamydospores with respect to cellular lipid and cell wall composition. While the thiols have different effects on the macroconidia, the fact that they all induce cell expansion suggests that they react at some common sites.

Amino Acids↗
PubMed1977

Requirements for the rapid conversion of macroconidia of Fusarium sulphureum to chlamydospores.

Chlamydospores of Fusarium sulphureum were formed within 72 h by incubating macroconidia at 37 degrees C in stationary culture in a medium containing mannitol and inorganic salts. The conversion process was dependent on inoculum level, temperature, aeration, and the presence of an external source of nitrogen and carbon. Chlamydospore formation was not inhibited by an uncoupler of oxidative phosphorylation, 2,4-dinitrophenol, or by inhibitors of bacterial cell wall synthesis; however, it was affected by inhibitors of respiration and of protein and chitin synthesis.

Air↗
PubMed1977

Ontogeny of lipid bodies in the endoplasmic reticulum of Fusarium sulphureum.

The ontogeny of lipid bodies during the differentiation of conidial cells to chlamydospores in Fusarium sulphureum (F. sambucinum f. 6) is described. The lipid bodies are first seen as electron-transparent areas within dilated cisternae of the endoplasmic reticulum (ER). One or more such cisternae may be formed within a strand of ER. The intracisternal lipid bodies are bounded by a unit membrane derived from the double membrane of the ER. The dilated cisternae increase in size and remain electron-transparent; however, some electron-dense granular material is present in the lipid bodies. The limiting unit membrane is visible throughout development of the lipid body; however, in mature chlamydospores the membrane is obscured by a broad band of electron-dense material which may provide protection to the stored lipids during adverse environmental conditions. The system of lipid body development in F. sulphureum is discussed in relation to those described for higher plants.

Endoplasmic Reticulum↗
PubMed1977

Cellular bodies in developing chlemydospores of Thielaviopsis basicola1,2.

The development of chlamydospores of Thielaviopsis basicola from hyphal cells involves the thickening and pigmentation of the cell wall. Electron microscope studies showed that membrane-bound cellular bodies appearing in the cytoplasm of differentiating cells developed from dilated cisternae in the endoplasmic reticulum. Within the membrane-bound bodies, vesicles of up to 0.2-micronm diameter were observed which contained electron-dense particles. Vesicles resembling those seen in the cellular body were also present in the cytoplasm close to the plasmalemma. In newly formed chlamydospore cells where wall thickening was complete, the cellular bodies showed loss of internal organization, and most of the vesicles disappeared, leaving a structure resembling a vacuole. The cellular bodies were not present in undifferentiated hyphae or in mature chlamydospores.

Cytoplasm↗
PubMed1975

Cell wall of Fusarium sulphureum; I. Chemical composition of the hyphal wall.

The hyphae wall of Fusarium sulphureum Schlect. (Isolate 1) was isolated and purified. Electron microscopy studies showed that the isolated cell wall consisted of two distinct layers, an outer electron dense layer and a broader electron transparent inner layer. Chemical analysis revealed that the cell wall contained 66% carbohydrate, 7.3% protein, 5.5% lipid and 1.8% ash. The major cell wall component N-acetylglucosamine (39%) was shown by X-ray diffraction analysis to be present as chitin. Glucose constituted 14% of the cell wall, while mannose, galactose, and glucuronic acid, accounted for 15% of the cell wall. Glucuronic acid appears to be predominantly linked to galactose in the intact wall.

Acetylglucosamine↗
PubMedDate not supplied

24-Hour ambulatory blood pressure monitoring in primary care.

BACKGROUND: Both the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of Hypertension in Adults and the British Hypertension Society have made recommendations for the use of ambulatory blood pressure monitoring (ABPM) in select patient populations. This demonstration project explores the feasibility of a 24-hour ABPM service in assisting physicians with decisions regarding the implementation and modification of antihypertensive therapy. METHODS: After physician referral, patients met with a pharmacist for evaluation of their blood pressure. The pharmacist obtained a medication profile and instructed each patient on the proper use of the monitor. Patients completed an activity diary while wearing the monitor. After analysis of the reports, the pharmacist forwarded recommendations and the 24-hour blood pressure data to the referring physician. RESULTS: Sixty patients took part in the demonstration project. The primary reasons for referral included evaluation of suspected isolated office hypertension, drug resistance, blood pressure control in diabetic patients, and suspected drug-induced orthostatic hypotension. The referring physicians accepted 100% of the pharmacists' therapeutic recommendations. Unnecessary therapy was avoided in 12 of 40 of patients with suspected isolated office hypertension (30%), and more aggressive treatment was started in 6 of 7 of patients with type 2 diabetes (87.5%). CONCLUSIONS: This project shows that a 24-hour ABPM consultation service can provide useful information for determining which patients have isolated office hypertension and in guiding drug regimen modification for patients with diabetes, suspected resistant hypertension, or drug-induced alterations in blood pressure.

Aged↗
PubMedDate not supplied

Combination therapy with low-dose lovastatin and niacin is as effective as higher-dose lovastatin.

STUDY OBJECTIVES: To determine if low-dose lovastatin in combination with niacin causes a greater percentage reduction in low-density lipoprotein (LDL) cholesterol than lovastatin alone, and to determine if the combination increases the risk of serious adverse effects. design. Prospective, randomized, open-label, clinical trial. setting. Family medicine clinic of a university-affiliated hospital. Patients. Patients with fasting LDL cholesterol concentrations of at least 150 mg/dl after 4 weeks of dietary stabilization and washout of any cholesterol-lowering drugs. INTERVENTIONS: Twenty-eight patients received lovastatin 20 mg/day for 4 weeks after dietary stabilization and washout. If LDL cholesterol remained above 130 mg/dl (100 mg/dl in patients with coronary artery disease), they were randomized to receive either lovastatin 40 mg/day or a combination of lovastatin 20 mg/day and niacin 500 mg 3 times/day. MEASUREMENTS AND MAIN RESULTS: There was no difference in actual or percentage reductions of LDL cholesterol, total cholesterol, and triglycerides between the groups. A greater increase in high-density lipoprotein (HDL) cholesterol occurred with combination therapy (p = 0.024). There was no difference in liver function tests, glucose, or uric acid between the therapies. Based on drug-acquisition cost, combination therapy is approximately 40% less expensive than monotherapy. CONCLUSION: Low-dose niacin plus low-dose lovastatin was as effective as higher-dose lovastatin in lowering total cholesterol, LDL cholesterol, and triglyceride levels. The combination may offer benefit in raising HDL cholesterol levels.

Adolescent↗
PubMedDate not supplied

Comparison of two formulations of nifedipine during 24-hour ambulatory blood pressure monitoring.

STUDY OBJECTIVE: To determine if one commercial extended-release formulation of nifedipine (Adalat CC) is as effective as another (procardia XL) in controlling blood pressure over 24 hours. DESIGN: Open-label, randomized, crossover study. SETTING: University-affiliated family medicine clinic. PATIENTS: Fifteen patients with stage 1-4 primary hypertension. INTERVENTIONS: Procardia XL or Adalat CC once/day was titrated to achieve blood pressure control. The effective dose was continued for 4 weeks, washed out for 1 week, and reinstituted with other study drug. MEASUREMENTS AND MAIN RESULTS: Twenty-four-hour ambulatory blood pressure was recorded the conclusion of each treatment phase. Treatment phases were compared for mean 24-hour blood pressure, mean daytime (6:00 A.M.-10:00 P.M.) and mean nighttime blood pressure, and mean blood pressure load (percentage of blood pressure measurements > 140/90 mm Hg daytime and > 120/80 mm Hg nighttime). Thirteen patients completed the study. No statistically significant difference was seen in mean 24-hour blood pressure (138/86 mm Hg for Procardia XL vs 137/85 mm Hg for Adalat CC), daytime or nighttime blood pressure, or blood pressure load. Two patients experienced clinically significant adverse effects while taking Adalat CC. CONCLUSIONS: In these patients with primary hypertension, Adalat CC was as effective as Procardia XL at controlling blood pressure for 24 hours. Blood pressure, heart rate, and adverse effects should be monitored 2-4 weeks after any exchange of Adalat CC for Procardia XL.

Adult↗
PubMedDate not supplied

The role of troglitazone in treating the insulin resistance syndrome.

Insulin resistance is characterized by impaired responsiveness to endogenous or exogenous insulin and often results in the insulin resistance syndrome, a clustering of cardiovascular risk factors that includes abdominal obesity, hypertension, dyslipidemia, glucose intolerance, and hyperinsulinemia. Although the mechanism responsible for insulin resistance has not been completely defined, it is likely due to defective insulin receptor signaling and results in decreased use of glucose. Troglitazone, the first in a new class of drugs, directly decreases insulin resistance by improving insulin-mediated glucose disposal and reduces plasma insulin concentrations. Glycemic control achieved with troglitazone monotherapy is equivalent to that with sulfonylurea and metformin, and when combined with these agents offers additional plasma glucose reduction. Studies are necessary to determine the effect of thiazolidinediones on morbidity and mortality of patients with type 2 diabetes and insulin resistance.

Chromans↗