Intracellular lipid droplets in functioning transitional parathyroid oxyphil adenomas. A caveat.

Histochemical demonstration of intracellular lipid droplets on frozen section has been used to distinguish normal parathyroid tissue from that of adenoma and chief cell hyperplasia. Differentiation is based on the observation that the cells of adenoma and chief-cell hyperplasia largely lack intracellular lipid, which is present in the suppressed chief cells of normal glands in patients with adenoma. We present two functional transitional oxyphil adenomas that contained abundant intracellular lipid.

Spurious cell surface receptors: inadequate correction for saturable, nonspecific binding mimics receptor binding.

Methods commonly used for the characterization of receptors on cell surfaces may be subject to adsorption artifacts that mimic the action of receptors even when no receptors are present. Traditional techniques such as incubation in the presence of an unrelated protein to minimize adsorption or extensive washing to eliminate nonspecific binding may be inadequate to ensure that the observed binding is due to a cell membrane--ligand interaction. In this paper three serum proteins, albumin, transferrin, and immunoglobulin G, are shown to exhibit behavior suggestive of receptor-mediated binding even in the absence of cells.

Lack of effect of atenolol and nadolol on the metabolism of theophylline.

The effects of 7 days of pretreatment with atenolol, 150 mg day-1, or nadolol, 80 mg day-1, on the pharmacokinetics and metabolism of theophylline were determined in six male smokers. Theophylline clearance, volume of distribution, half-life and the urinary excretion of theophylline and its metabolites were unchanged during either treatment compared with control.

The prediction of midlife coronary heart disease and hypertension in young adults: the Johns Hopkins multiple risk equations.

Educating medical students about the identification of risk factors for coronary disease and hypertension should be enhanced by exercises in which medical students identify their own risk factors and visualize the impact of current risk status on future risk of disease. A cohort of 1,130 former Johns Hopkins medical students were examined in medical school and followed annually from 1948 to 1964 to identify youthful factors associated with the development of coronary heart disease and hypertension in midlife. In the ensuing years through 1984, 51 cases of coronary heart disease and 114 cases of hypertension developed.

Major genetic mechanisms in pulmonary function.

Regressive models were used to search for possible major gene effects on pulmonary function in two groups of families: one ascertained through patients with chronic obstructive pulmonary disease [COPD defined as forced expiratory volume in one second (FEV1) less than 70% forced vital capacity (FVC)] and the other ascertained through patients with non-pulmonary disorders. There were 85 COPD families with data on 270 individuals and 56 non-pulmonary families with data on 199 individuals. The analysis was done on residuals obtained from a regression of FEV1 on age, sex, race, height, and ascertainment group.

The Bassett Farm Safety and Health Project.

The Bassett Farm Safety and Health Project was started in 1980 when Drs. May and Pratt made clinical observations on respiratory illnesses in farmers. The initial work involved the investigation of clinical syndromes associated with dust exposures and, from there, environmental dust studies.

The effect of tamoxifen on cervical squamous maturation in Papanicolaou stained cervical smears of post-menopausal women.

Using cervical smears obtained as part of routine gynaecological examinations, a retrospective study of the effects of the drug tamoxifen on squamous epithelial maturation of the cervix of post-menopausal women being treated for advanced breast cancer was made. The degree of squamous epithelial maturation was quantitated by using the Maturation Index and the Maturation Value. Although tamoxifen is a synthetic, non-steroidal compound classified as anti-oestrogenic, the findings indicate that this drug commonly produces a level of squamous maturation indicative of oestrogenic stimulation in Papanicolaou stained cervical smears from post-menopausal patients receiving this drug.

Plasma free thyroxine concentrations in patients receiving levothyroxine for thyroid suppression.

The usual recommendation is to follow total triiodothyronine (T3) concentration during levothyroxine (L-thyroxine) therapy because 65% of clinically euthyroid patients receiving L-thyroxine have normal T3 but elevated total thyroxine (T4) levels. Because free thyroxine (FT4) is the metabolically active form of T4, our study was designed to determine whether FT4 by analog radioimmunoassay method is normal or increased in euthyroid patients receiving L-thyroxine. Twenty-seven clinically euthyroid patients, 5 males and 22 females, receiving L-thyroxine for thyroid suppression, were studied in a prospective protocol.

Dendritic cell ontogeny.

Abundant evidence indicates that dendritic cells arise from the bone marrow. In vitro, precursors that differ phenotypically from mature dendritic cells divide several times to form functional dendritic cells. A soluble factor(s) produced in the supernatants of ConA-stimulated spleen cells enhances the production of dendritic cells.

Long-term results of bifocal therapy for accommodative esotropia.

We studied the long-term course of 65 accommodative esotropes who required bifocals to maintain alignment at near. Average follow-up was 10.5 years.

Gentamicin pharmacokinetics, nephrotoxicity, and prediction of mortality in febrile neutropenic patients.

The pharmacokinetics of gentamicin in 34 febrile neutropenic patients (40 courses) were compared with those in 40 nonneutropenic patients receiving the drug. No pharmacokinetic differences were seen in half-life, volume of distribution (liter per kilogram; total and ideal body weight), or clearance (milliliter per minute per 1.73 m2).

Absence of tobramycin pharmacokinetic and creatinine clearance variation during the menstrual cycle: implied absence of variation in glomerular filtration rate.

During the menstrual cycle, a 20% increase in creatinine clearance (CL(CR] has previously been reported between the menstrual (phase 1) and late luteal (phase 4) phases. Tobramycin pharmacokinetics and CL(CR) were studied in eight healthy women with documented, regular, ovulatory menses. During the first and fourth phases of the menstrual cycle (as determined by urinary luteinizing hormone peak and basal body temperature shift), subjects received tobramycin by intravenous bolus.

The albumin receptor effect may be due to a surface-induced conformational change in albumin.

To determine whether equilibrium binding between albumin and hepatocytes involves a cell surface receptor for albumin, we incubated freshly isolated rat hepatocytes with 125I-albumin and determined the amount of albumin associated with the cells as a function of the total albumin concentration. The resulting two-phase binding curve showed the rat albumin-hepatocyte interaction to consist of a saturable binding interaction with a dissociation constant of 1.1 microM and 2 X 10(6) sites/cell in addition to a weak, nonsaturable binding interaction.

Constancy of glucose and starch fermentations by two different human faecal microbial communities.

The fermentation of glucose and corn starch by faecal suspensions from two subjects was examined over a three and a half year period. The substrate specificity and products of the faecal fermentations of each subject were relatively stable during this period and were significantly different between subjects. The major soluble end products of fermentation of glucose or starch were acetate, propionate, and butyrate.

A comparison of retrobulbar and periocular anesthesia for cataract surgery.

Complications of retrobulbar anesthesia are rare but significant. Periocular anesthesia has been advocated as an alternative to retrobulbar injections. In a prospective, randomized, masked study of 79 consecutive cataract extractions with intraocular lens implantations, 40 patients received retrobulbar injections and 39 patients received periocular injections.

Solubility and stability of amphotericin B in human serum.

The solubility and stability of amphotericin B in human serum in vitro was assessed using a sensitive high performance liquid chromatographic technique. The solubility of amphotericin B at concentrations ranging from 0.5 micrograms/ml to 10 micrograms/ml in human serum at pH 7.

Influences on CHD incidence and case fatality: medical management of risk factors.

The possible role of medical management of risk factors as an explanation of international trends in coronary heart disease (CHD) mortality has been reviewed. In general, hypertension, hypercholesterolaemia and smoking are the only risk factors that can be detected and treated, with a significant effect on CHD risk. Few organized international data are available to relate to international CHD trends.