Diagnostic criteria for schwannomatosis.

The neurofibromatoses are a diverse group of genetic conditions that share a predisposition to the development of tumors of the nerve sheath. Schwannomatosis is a recently recognized third major form of neurofibromatosis (NF) that causes multiple schwannomas without vestibular tumors diagnostic of NF2. Patients with schwannomatosis represent 2.4 to 5% of all patients requiring schwannoma resection and approximately one third of patients with schwannomatosis have anatomically localized disease with tumors limited to a single limb or segment of spine. Epidemiologic studies suggest that schwannomatosis is as common as NF2, but that familial occurrence is inexplicably rare. Patients with schwannomatosis overwhelmingly present with pain, and pain remains the primary clinical problem and indication for surgery. Diagnostic criteria for schwannomatosis are needed for both clinicians and researchers, but final diagnostic certainly will await the identification of the schwannomatosis locus itself.

Cu/Zn superoxide dismutase activity in familial and sporadic amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a degenerative motor neuron disease that is inherited as an autosomal dominant trait in approximately 10% of cases. Recently we and others identified several single-base mutations in the Cu/Zn superoxide dismutase (SOD1) gene in patients with familial ALS (FALS). Using single-strand conformational polymorphism, we studied the C to G mutation in exon 2 of the SOD1 gene (resulting in a leucine to valine substitution in position 38) in affected and unaffected members of a large Belgian family with FALS. We measured the SOD1 activity in red blood cell lysates in 14 members of this family, including the only surviving clinically affected patient. SOD1 activity of the family members carrying the mutation was less than half that of members without the mutation. In addition, in 11 patients with sporadic ALS and 11 age- and sex-matched controls, red blood cell SOD1 activity was normal. These studies indicate that SOD1 activity is reduced in these FALS patients but not in sporadic ALS patients. Moreover, this SOD1 enzyme abnormality is detectable years before onset of clinical ALS in carriers of this FALS mutation.

Lipid and lipoprotein distributions in black adults. The Cincinnati Lipid Research Clinic's Princeton School Study.

To provide population data on levels of plasma cholesterol, triglyceride, and high- and low-density lipoprotein-cholesterol (HDL-C and LDL-C) in black adults, 627 black adults, aged 20 to 59 years, 206 men and 421 women, were studied in the Cincinnati Lipid Research Clinic's Princeton School Study. Comparisons were made with 2,493 white adults, aged 20 to 59 years, 1,111 men and 1,382 women, from the Princeton School Study. Black men had total plasma cholesterol levels that were comparable with those in whites; plasma cholesterol levels were higher in black than white women. Black men had lower levels of plasma triglycerides, higher HDL-C levels, and lower LDL-C levels than white men. Black women not taking exogenous sex steroid hormones had higher total cholesterol and HDL-C levels, and lower triglyceride and LDL-C levels than white women not taking exogenous sex steroid hormones. Black women taking exogenous sex steroid hormones had lower plasma cholesterol and triglyceride levels and slightly higher HDL-C and lower LDL-C levels than white women taking exogenous sex steroid hormones. These differences not only require the use of race-specific lipoprotein distribution tables for characterization of individual subjects, but are consistent with putatively reduced risk for coronary heart disease in blacks when compared with whites.

Clustering and interrelationships of coronary heart disease risk factors in schoolchildren, ages 6-19.

Clustering and interrelationships of common and easily identifiable risk factors in 951 children (ages 6-19) from the Cincinnati Lipid Research Clinic's Princeton School of District Study were assessed. Several patterns of partial correlation coeffieients appeared after multiple regression analysis with adjustment for age, sex, Quetelet index, and race. Systolic blood pressure (SBP) was positively correlated with plasma cholesterol and triglyceride, and with saturated fat intake. Plasma high density lipoprotein cholesterol (C-HDL) was positively associated with occupation of the head of the household and inversely associated with cigarette smoking and sucrose intake. Using multiple regression equations, from 29-41% of the variance for SBP and diastolic blood pressure (DBP) could be explained by the measured variables, with age, skinfold thickness, Quetelet, occupation, and education of the head of the household recurrently appearing in the regression equatons. Low density lipoprotein cholesterol (C-HDL) was the variable for which the lowest amount of variance could be explained in the four race-sex groups. Discriminant function analysis allowed an assessment of interrelationships of C-LDL-C-HDL aggregate groups to other risk factor mean residuals. The variables which contributed significantly to the discrimination between lipoprotein groups were Quetelet index, skinfold thickness, and DBP. Children in the highest C-LHL-lowest C-HDL quintile group had by far the highest residual Quetelet index and skinfold thickness, along with above average SBP, while those in The lowest C-LDL-highest C-HDL quintile group had the lowest residual Quetelet index, skinfold thickness, and SBP. Common risk and anti-risk factors for coronary heart disease (CHD) in children cluster, allowing identification of groups of children putatively at relatively high and low CHD risk as adults.

The significance of the MB isoenzyme in patients with acute cardiovascular disease with a normal or borderline total CPK activity.

CPK MB isoenzymes were qualitatively identified using an electrophoresis method in 166 patients with acute cardiovascular disease during a six month period. Forty-three had total CPK activity in the normal or borderline range (0--75 U/Liter at the time the MB isoenzyme was first identified. Fifteen of these patients were diagnosed as having had a new acute myocardinal infarction (Group I) and another 15 as having had an old myocardial infarction (Group II). Diagnosis was based on electrocardiographic changes or autopsy findings. The remaining 13 patients were classified as "ischemic heart disease" (Group III) in the absence of strict electrocardiographic criteria or autopsy evidence of myocardial infarction. Nine of the 15 patients in Group I subsequently had elevations of their total CPK activity above 75 U/L. In contrast the total CPK activity of only one patient from Group II and Group III subsequently exceeded 75 U/liter. All 43 patients had evidence of cardiovascular disease. Our findings suggest that the detection of MB isoenzyme in the presence of a normal total CPK activity is a significant laboratory finding and is indicative of cardiac myofiber injury.

Determination of acetaminophen concentrations in serum by high-pressure liquid chromatography.

We describe a method for determination of serum acetaminophen concentrations in serum by reversed phase high-pressure liquid chromatography. The homolog N-propionyl-p-aminophenol was used as an internal standard. The procedure, which requires only a single extraction with diethyl ether, can be optimized to be linear over the ranges of 10 to 100 or 1 to 20 mg/liter. Within-run CV was 1.2%; between-run CV was 4.4% and 4.9% at two different concentrations. Many commonly used drugs were tested and found not to interfere. The procedure is simple and rapid enough for use on an emergency basis in cases of overdosage, and can be optimized for measurement of either therapeutic or toxic concentrations.

A clinical study of the role of enterococci as sole agents of wound and tissue infection.

Patients who had enterococci isolated from wounds or tissues were identified from laboratory records. The charts of patients with pure cultures of enterococci were reviewed to determine the degree of clinically significant infection. We found that the frequency of infections in patients with pure cultures of enterococci was not significantly different from the frequency of infections in a control series of patients with negative cultures, but that it was significantly different from the frequency of infections in a series of patients with pure cultures of Staphylococcus aureus. Our conclusion that enterococci are not by themselves significant pathogens in wound or tissue infections is supported by a few experimental studies of other authors.

Interpretation of blood cultures yielding Staphylococcus aureus.

Forty-eight patients with blood cultures positive for Staphylococcus aureus were classified according to clinical criteria in three groups: "definite", "possible", and "doubtful" septicemia. Using traditional blood culture sets with two bottles (thioglycollate and tryptic soy broths), we found that patients with "definite" septicemia always showed more than one positive bottle per day if more than one set was drawn, that the mean detection time was 1.7 days, and that 95% of the first positive bottles and 92% of all positive bottles grew within two days of incubation. Patients with "doubtful" septicemia were more often (88%) positive in one bottle only, the mean detection time for all bottles was 3.7 days, and only 35% of the first positive bottles and 33% of all positive bottles yielded growth within two days. "Possible" cases took a position between these two extremes but tended more towards the "doubtful" cases. The implications of these findings for the interpretation of blood cultures with S. aureus are discussed.

Savings from generic prescriptions. A study of 33 pharmacies in Rochester, New York.

Brand name and gereric prescriptions for 12 drugs were surveyed at 33 pharmacies in the Rochester, New York, area to determine how frequently generic prescriptions were filled with a product other than the major brand, and at a savings to the consumer. Generic prescriptions for ampicillin, erythromycin, propoxyphene, and dioctyl sodium sulfosuccinate were often filled at prices lower than comparable brand name prescriptions. Occasional, but often substantial, savings were obtained for papaverine, pentaerythritol tetranitrate, and conjugated estrogens. No savings were obtained for penicillin V, chlorpheniramine, diphenylhydantoin, sulfisoxazole, or methenamine mandelate. The pharmacists included in the survey identified correctly a mean of 18.5 out of 22 drugs as to whether products other than the major brand were available. A sample of physicians identified correctly a mean of 14.1 drugs. Pharmacists who were better informed as to which drugs were available generically were more likely to stock alternative products and more likely to charge lower prices on generic prescriptions than on brand name prescriptions.