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Biomedical subjects

L Alexander

Publications and source records attributed to L Alexander.

At least 73 records · Page 4Linked to original sources
PubMed1990

Transcriptional regulation of the murine TSH subunit genes.

These studies have demonstrated that the murine TSH subunit genes are sensitively regulated by thyroid hormone. The T3 receptor complex interacts with both the TSH beta and alpha-subunit gene either in or near the 5' flanking region in close proximity to the transcriptional start sites. This interaction interrupts transcription from the start sites, thus decreasing transcription of the two genes. As a result steady state mRNA levels of both TSH beta and alpha-subunit genes are decreased in the cytoplasm of thyrotropic cells. This series of interactions explains most of the effects of T3 on TSH biosynthesis.

Animals↗
PubMed1989

Chromatographic separations of serum proteins on immobilized metal ion stationary phases.

The separation of proteins on stationary phases consisting of a bound organic chelator and a chelated divalent transition metal has been studied as a function of (A) metal ion species; (B) mobile phase composition and pH; and (C) anion and cation concentration. Optimum separation was observed at alkaline pH on chelated nickel stationary phases. Ammonium and Tris salts reduced the affinity of the metal chelate packing for serum proteins. Halide ions caused the proteins to be more strongly bound to the stationary phase. High salt concentrations had only a small effect on the binding of serum proteins in the absence of amine containing buffers or salts. It was also observed that the ease of elution and the recovery of protein were dependent on pH and upon the presence of halides. The general order of elution of serum proteins, based on isoelectric focusing, was independent of metal ion species and elution conditions, suggesting that a single mechanism or a unique sequence of mechanisms was operative. The results suggest that ligand exchange is the major mechanism of separation under basic conditions and that hydrophobic effects are the result of the competition of nonnitrogen ions with ammonium ions or amines for ligand binding sites modifying or participating in protein binding. Protein binding studies under weak acidic conditions are also presented although the mechanism responsible for protein binding is unclear.

Blood Protein Electrophoresis↗
PubMed1989

Ibuprofen, acetaminophen, and placebo treatment of febrile children.

A double-blind, parallel-group, triple-dummy-designed, single-oral-dose study compared the efficacy, tolerability, safety, and dose-response of 5 mg/kg (n = 32) and 10 mg/kg (n = 28) ibuprofen suspension, 10 mg/kg acetaminophen elixir (n = 33), and placebo liquids (n = 34) in 127 children (2 to 11 years of age) with fever (101 degrees to 104 degrees F). Blood samples, oral temperatures, pulse, blood pressure, and respiration were obtained before and 1/2, 1, 2, 3, 4, 5, 6, and 8 hours after the dose was administered. The study was terminated early if oral temperature was greater than 104 degrees F or if it increased 1 degree F above baseline. All agents were well tolerated and more effective than placebo (p less than 0.05) for fever control. Ibuprofen, 10 mg/kg, was favored over 10 mg/kg acetaminophen (p less than 0.05). For temperatures greater than 102.5 degrees F, a dose-response relationship for 5 and 10 mg/kg ibuprofen was demonstrated in terms of percentage of fever reduction and in terms of the initial 2-hour rate of decrease in temperature. Antipyretic efficacy for temperatures greater than 102.5 degrees F was 10 mg/kg ibuprofen greater than 5 mg/kg greater than 10 mg/kg acetaminophen greater than placebo. All treatments were well tolerated. No significant clinical or laboratory abnormalities were noted. Ibuprofen suspension may be a safe and effective antipyretic in children.

Acetaminophen↗
PubMed1986

The effects of diabetes mellitus, exercise, and single doses of biguanides upon lactate metabolism in man.

The polymorphism of phenformin oxidation has been investigated in 103 non-insulin-dependent (Type II) diabetics. The frequency distribution was clearly bimodal and 14 poor metabolisers were identified. The frequency of the recessive allele (0.369) was not significantly different from that found previously in non-diabetics. Six of the extensive metabolisers of phenformin were matched for age, sex and oxidizer phenotype with non-diabetic controls. All subjects underwent a standard 3-min exercise test, using a bicycle ergometer, after which plasma lactate concentration was monitored for 90 min. There was no significant difference between groups in lactate accumulation or elimination. Ten extensive metabolisers, ten poor metabolisers and seven non-diabetics (matched for age, sex and phenotype with seven of the diabetic extensive metabolisers) were challenged with a fasting oral dose of phenformin (50 mg), after which plasma lactate, and blood pyruvate and glucose concentrations were monitored for 4 h. A further ten diabetics (five extensive and five poor metabolisers of phenformin) received a single dose of metformin (1 g) following an identical protocol. No significant changes were observed in any group.

Adult↗
PubMed1986

Acoustic emission cochleography--practical aspects.

Otoacoustic emissions are discussed as a means of objectively examining cochlear status. Practical uses of otoacoustic emission recording are reviewed, and the technical requirements of a clinical test are discussed. Details are given of an advanced cochlear echo test procedure, and results from normal and hearing impaired ears are discussed. Finally the alternative technique of distortion product analysis is discussed and results are given.

Biomechanical Phenomena↗
PubMed1985

Ornithodoros coriaceus (pajaroello tick) as a vector of bluetongue virus.

Preliminary studies demonstrated that the argasid tick, Ornithodoros coriaceus Koch, could become infected with bluetongue virus (BTV). Ticks became infected after feeding through artificial membranes on BTV-infected suspensions of cell cultures, chicken embryos, and sheep blood. Ticks also became infected after natural feeding on viremic sheep (BTV serotype 17) and cattle (BTV serotype 11). Virus was recovered from the hemolymph and salivary glands of ticks which had ingested BTV either through an artificial membrane or by natural feeding on a host animal. Ticks infected with BTV serotype 13 were capable of transmitting the virus to a susceptible cow at 42 days after ingestion of virus-infected cultures, thus demonstrating the potential of the tick to serve as a biological vector of BTV.

Animals↗
PubMed1983

Inoperable gastric lymphosarcoma mistaken for carcinoma: response to radiation with twenty-year survival to date.

With suitable treatment, the potential for long survival with gastric lymphoma is well-documented. However, since these tumors constitute only about 1-3% of gastric malignancies, they may occur only rarely in a particular radiologist's experience. The present report of a remarkable therapeutic response is a reminder that the possibility of lymphosarcoma should be included in the differential diagnosis of every gastric neoplasm.

Carcinoma↗
PubMed1983

Two helping alliance methods for predicting outcomes of psychotherapy. A counting signs vs. a global rating method.

This paper reports on the development of measures of helping alliances in psychotherapy, i.e., the patient's experience of the treatment or relationship with the therapist as helpful, or potentially helpful. The helping alliance counting signs measure, which is the special focus of this paper, entails the counting of certain types of patient statements (signs) which are identified in a manual. The main findings were: a) these types of statements were found to be "scorable" with moderate interjudge agreement; b) scores based on the manual showed moderate agreement with a similar helping alliance manual based upon global ratings; c) scores were fairly to moderately consistent from early to late in treatment; d) scores predicted outcome significantly, e.g., early positive signs of helping alliance correlated .57 (p less than .01) with rated benefits, and .59 (p less than .01) with change in the first target complaint (Battle, C., Imber, S., Hoehn-Saric, R., et al. Target complaints as criteria of improvement. Am. J. Psychother., 20: 184-192, 1966); and e) basic background similarities between patient and therapist, such as in age and religious activity, attained highest correlations with the helping alliance measure, e.g., the sum of 10 similarities correlated .60 (p less than .01) with early positive helping alliance counting signs.

Adult↗
PubMed1982

Lithium in aggressive behavior.

A patient with intractable aggression was treated with lithium carbonate. On the basis of the authors' study and their review of the literature, they conclude that lithium may exacerbate the interictal aggression sometimes noted in patients with temporal lobe spike activity.

Adult↗
PubMed1981

An alternative model for the psychiatric clerkship.

Clinical clerkships in psychiatry are traditionally based on in-patient services and thus limit student exposure in the main to seriously ill psychiatric patients. Such clerkships have been criticized as having questionable relevance to the primary care careers which are increasingly selected by medical students. The present paper describes a clerkship in which half the students are taught on a traditional in-patient service while half go to a special medical-psychiatric unit. In the latter situation, medical and psychiatric patients are housed together and consultation-liaison experiences play a prominent part in the students' experience. Some comparative data are presented which suggest that the two clerkship experiences are equally satisfactory to the students. It is concluded that a psychiatric clerkship utilizing settings and experiences which are close in character to primary care is educationally feasible.

Education, Medical, Undergraduate↗
PubMed1980

Epidemiology of acromegaly in the Newcastle region.

In an attempt to derive estimates of the incidence and prevalence of acromegaly a survey of the population in the area served by the former Newcastle Regional Hospital Board has been conducted to detect cases of acromegaly alive after 1 January 1960 and diagnosed before 31 December 1971. Cases were detected by means of letters to general practitioners, hospital physicians, neurosurgeons and to hospital records officers, as well as from death certificates. From the population of 3.1 millions a firm diagnosis of acromegaly was made in 164 patients, in eighty-one on clinical grounds alone and in eighty-three with confirmation by assay of human growth hormone (hGH). The annual incidence of acromegaly appears to be close to three cases per million and the prevalence of diagnosed cases up to forty cases per million. In male acromegalics there was a significant increase in the risk of death from cardiovascular, cerebrovascular respiratory and malignant diseases but in females from cerebrovascular disease only.

Acromegaly↗