PubMed Health⌕ Search

Biomedical subjects

M A Goetz

Publications and source records attributed to M A Goetz.

31 records · Page 2Linked to original sources

Barceloneic acid A, a new farnesyl-protein transferase inhibitor from a Phoma species.

Three new diphenyl ethers, barceloneic acids A, B, and barceloneic lactone [1, 2, and 3, respectively] were isolated from a fermentation extract of a fungus of the genus Phoma. The structures of compounds 1-3 were determined by a combination of spectroscopic and single-crystal X-ray diffraction methods. The effect of these compounds on the inhibition of farnesyl-protein transferase (FPTase) was evaluated and results are presented. Barceloneic acid A [1] is a novel and modest inhibitor of FPTase with an IC50 value of 40 microM.

Alkyl and Aryl Transferases↗

Mountain cedar allergens found in nonpollen tree parts.

BACKGROUND: Mountain cedar (Juniperus ashei) pollen is the principal aeroallergen in south central Texas from late December through February. The major mountain cedar allergen is a 40-kD glycoprotein, gp40. OBJECTIVE: To identify allergens in mountain cedar wood, leaves, and berries and to detect mountain cedar allergen in smoke from burning male or female trees. METHODS: SDS-PAGE plus mountain cedar human sIgE and monoclonal antibody immunoblots identified mountain cedar allergens within pollen and nonpollen tree part extracts. RESULTS: IgE immunoblots identified a single wood allergen at 36 kD and three berry allergens at 36, 26-27, and 21 kD, in addition to known pollen allergens. Mountain cedar monoclonal antibody bound an allergen epitope present not only on 40, 33, and 28-kD pollen allergens, but also on 36 and 32-kD wood allergens, and the 26-27-kD berry allergen. Immunoblot studies detected no mountain cedar allergen in leaves and no allergen in smoke from burning male and female trees. Allergens constituted a much smaller percentage of extractable protein in wood and berries than in pollen. CONCLUSIONS: Mountain cedar berry allergen content is too small to give credence to the ingestion of berries as a folk medicine treatment of mountain cedar pollinosis. In addition, while smoke from burning mountain cedar trees may be irritating, it contains no allergens that could cause allergic rhinoconjunctivitis.

Allergens↗

A light stabilizer (Tinuvin 770) that elutes from polypropylene plastic tubes is a potent L-type Ca(2+)-channel blocker.

A pharmacologically active agent was easily extracted by aqueous or organic solvents from laboratory plastic tubes (Falcon Blue Max) and has been chemically identified as bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate. This compound (approximately 12 micrograms per tube approximately 25 nmol) blocked 1,4-dihydropyridine-sensitive 45Ca2+ uptake into GH3 cells with an IC50 value of 3.6 microM, inhibited Sr2+ currents through L-type Ca2+ channels in A7r5 smooth-muscle cells in whole-cell patch-clamp experiments after extracellular application, and affected the high-affinity binding of Ca2+ entry-blocker ligands to a variety of preparations. Bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate is a highly potent (IC50 values < 10 nM) inhibitor at the phenylalkylamine- and benzothiazepine-selective drug-binding domains of the alpha 1 subunit of L-type Ca2+ channels. This compound behaves as a heterotropic allosteric regulator for the 1,4-dihydropyridine-selective domain in purified Ca(2+)-channel preparations from rabbit skeletal muscle. (+)-Tetrandrine stimulation of 1,4-dihydropyridine binding to the membrane-bound L-type Ca2+ channel is inhibited by the compound in a competitive manner (Ki value = 6.8 nM). Bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate is therefore classified as the prototype of another class of L-type Ca(2+)-channel blockers that binds to the alpha 1 subunit at the drug-binding domains selective for (+)-tetrandrine or (+)-cis-diltiazem. This compound is identical to Tinuvin 770, which is used worldwide as a light stabilizer for polyolefins.

Alkaloids↗

A structurally unique, potent, and selective oxytocin antagonist derived from Streptomyces silvensis.

The in vitro and in vivo oxytocin/arginine vasopressin (OT/AVP) antagonist properties of two cyclic hexapeptides derived from a newly discovered natural product (L-156,373) of Streptomyces silvensis are described. In radioligand binding assays, L-156,373 [cyclo(L-Pro-D-Phe-N-OH-L-Ile-D-piperazyl-L-piperazyl-N-Me-D -Phe)] exhibited moderate affinity for rat uterine OT receptors (Ki, 150 nM), with some selectivity (approximately 20-fold) vs. liver AVP-V1 and kidney AVP-V2 receptors. Dehydroxylation of N-hydroxyisoleucine and oxidation of the piperazic acid residues of L-156-373 produced an interesting derivative, L-365,209. These structural modifications increased OT receptor affinity and selectivity by 20- and 2.5-5-fold, respectively. In the isolated rat uterus, L-365,209 was a potent (apparent dissociation constant, 1.7 nM) and competitive OT antagonist. L-365,209 also blocked the effects of AVP at both AVP-V1 (phosphatidylinositol turnover in rat hepatocytes) and AVP-V2 (adenylate cyclase in rat kidney medulla) receptors, but only at low micromolar concentrations. L-365,209, given iv to anesthetized rats, antagonized the action of exogenous OT on the uterus (ID50, 460 micrograms/kg) with a relatively long duration of action. L-365,209 represents a unique class of compounds that provides an entirely new approach for the design of antagonists for these neurohypophyseal hormones.

Animals↗

A potent nonpeptide cholecystokinin antagonist selective for peripheral tissues isolated from Aspergillus alliaceus.

A new, competitive, nonpeptide cholecystokinin (CCK) antagonist, asperlicin, was isolated from the fungus Aspergillus alliaceus. The compound has 300 to 400 times the affinity for pancreatic, ileal, and gallbladder CCK receptors than proglumide, a standard agent of this class. Moreover, asperlicin is highly selective for peripheral CCK receptors relative to brain CCK and gastrin receptors. Since asperlicin also exhibits long-lasting CCK antagonist activity in vivo, it should provide a valuable tool for investigating the physiological and pharmacological actions of CCK.

Animals↗

Prenatal alcohol consumption. Self versus collateral report.

The reservations expressed about the accuracy of patient self-reports of drinking may be heightened when obtaining information about prenatal alcohol consumption, which may be subject to fears of social or medical disapproval. Thus, clinicians may seek collateral reports to confirm patients' reports during this critical time. The purpose of this study is to compare the self and collateral reports of antepartum alcohol consumption by 247 pregnant women, obtained shortly after the initiation of prenatal care, and again after delivery. Collateral reports of subjects were exceeded by the subjects' self-reports of alcohol consumption before pregnancy and in the antepartum.

Adult↗

Evaluation of a hospital-based youth violence intervention.

To decrease adolescent morbidity and mortality and improve the quality of life, a violence-prevention consultation is offered to hospitalized victims of nondomestic violence. The context is a violence-prevention team approach to patient assessment, treatment, and follow-up. Psychoeducational counseling emphasizes the individual through a cognitive behavioral approach and also recognizes the individual in the proximal social setting through referrals to community resources. The in-hospital component draws on the health beliefs model, self-efficacy, the theory of reasoned action and their synergy with cognitive mediation theory as expressed in developmental psychology. The target group for the intervention is adolescents (12-17 years of age) who have been victims of violent assaults severe enough to warrant treatment at a Level One trauma center. The six steps in the intervention are to (1) review and assess the incident, (2) review the patient's conflict-resolution strategies and introduce nonviolent alternatives, (3) provide information on the prevalence of violence/homicide and determine the patient's risk status, (4) explore the patient's coping skills and support system, (5) develop a plan to stay safe, and (6) refer patient to services for follow-up activities. Approximately 15 study participants are identified each month, half of whom are randomly assigned to receive the intervention. Over the 12-month recruitment interval, approximately 180 adolescent patients will be identified. Baseline data are collected through hospital intake procedures and chart reviews. A battery of standardized measures supplemented by a brief structured, closed-ended interview is collected four months after the youths leave the hospital. Preliminary baseline data for 39 youths are reported. The "typical" youth is a 16-year-old African-American male. Even though nearly one third of victims had been shot, the typical patient was injured in a fight during which he was kicked, bitten, or beaten with or without a blunt instrument. The majority of incidents involved only one attacker who was known to the victim. Nearly half the injuries were precipitated by an argument or fight. No statistically significant differences between intervention subjects and nonintervention controls in terms of baseline variables have been observed. For inner-city adolescent victims of violent assaults, a hospital-based intervention offers a unique opportunity for reduction of the incidence of reinjury. We describe the elements of the intervention, including the theoretical basis and implementation; detail the overall evaluation design including modifications; and present preliminary analyses of baseline data.

Adolescent↗