Association of dietary protein intake and coffee consumption with serum homocysteine concentrations in an older population

BACKGROUND: Elevated blood concentrations of total homocysteine (tHcy) have been implicated in the pathogenesis of atherosclerotic cardiovascular disease. Previous studies identified suboptimal nutritional status and dietary intake of folate, vitamin B-6, and vitamin B-12 as determinants of elevated tHcy. OBJECTIVE: We identified other nutritional factors associated with tHcy in 260 retired schoolteachers in the Baltimore metropolitan area. DESIGN: We performed observational analyses of baseline and 2-4-mo follow-up data collected in a study designed to test the feasibility of conducting a large-scale clinical trial of vitamin supplements by mail. The study population consisted of 151 women and 109 men with a median age of 64 y. At baseline, each participant completed a food-frequency questionnaire. At follow-up, fasting serum tHcy was measured. RESULTS: In multivariable linear regression and generalized linear models, there was an independent, inverse dose-response relation between dietary protein and In tHcy (P = 0.002) and a positive, significant dose-response relation between coffee consumption and In tHcy (P for trend = 0.01). Other significant predictors of In tHcy were creatinine (positive; P = 0.0001) and prestudy use of supplemental B vitamins (inverse; P = 0.03). In stratified analyses restricted to persons receiving standard multivitamin therapy, the association of 1n tHcy with dietary protein and coffee persisted. CONCLUSIONS: These results support the hypothesis that increased protein intake and decreased coffee consumption may reduce tHcy and potentially prevent atherosclerotic cardiovascular disease and other disease outcomes.     

Multidisciplinary team dynamics in the production of problem-based-learning cases in issues related to older adults

Two important goals in allied health education are to prepare future allied health professionals to function as members of interdisciplinary teams and to increase their awareness of issues related to the growing older adult population. The responsibility for achieving these goals rests on the faculty and administrators of allied health education programs, who may not themselves be proficient in either of these domains. A multidisciplinary team of health educators and administrators was brought together to produce six problem-based learning (PBL) cases related to older adults. Members of the team represented a variety of disciplines in health care, diverse philosophies of educational development, a variety of roles in allied health education, and differing levels of knowledge of issues related to older adults--parameters similar to those found in the members of an interdisciplinary healthcare team. The methods by which this multidisciplinary group functioned and the dynamics in attaining the goals of the project are presented.     

Activation of tyrosine receptor kinase plays a role in expression of long-term potentiation in the rat dentate gyrus

Long-term potentiation (LTP) in perforant path-granule cell synapses has been shown to be accompanied by an increase in glutamate release. The objective of this study was to examine the possibility that nerve growth factor (NGF), by activating tyrosine kinase, modulates glutamate release and, therefore, contributes to expression of LTP in dentate gyrus. The data indicate that NGF, in the presence of trans-1-aminocyclopentyl-1,3-dicarboxylate (ACPD), enhanced KCI-stimulated release and KCI-stimulated calcium influx in vitro and that these effects were blocked by the tyrosine receptor kinase (trk) inhibitor tyrphostin AG879. The data also indicate that NGF increased phosphorylation of trkA and the mitogen-activated protein kinase extracellular signal-regulated kinase (ERK) in dentate gyrus in vitro. In addition to its effects in vitro, tyrphostin AG879 inhibited the expression of LTP in perforant path-granule cell synapses and the accompanying increase in transmitter release. Analysis of phosphorylation of the two tyrosine kinase substrates trkA and ERK in synaptosomes prepared from untetanized and tetanized dentate gyrus revealed that LTP was associated with increased phosphorylation of both proteins; no evidence of such a change was observed in either tetanized or untetanized tissue prepared from tyrphostin-pretreated rats. These findings are consistent with the hypothesis that NGF, by interacting with trkA, triggers a sequence of tyrosine kinase-dependent phosphorylation steps that modulate glutamate release and calcium influx and impact on expression of LTP in dentate gyrus.     

Persistent transgene product in retina, optic nerve and brain after intraocular injection of rAAV.

Recombinant adeno-associated virus (rAAV) is a promising vector for retinal application as it transduces photoreceptors and retinal pigment epithelium cells efficiently and in a stable fashion. Because rAAV also transduces retinal ganglion cells, we reasoned that ocular application of rAAV might result in delivery of transgenic protein to the CNS. Here we describe high levels of green fluorescent protein (GFP) persisting at least 6 months in optic nerves and brains of mice and dogs after intravitreal delivery of rAAV-GFP. There was no clinical or histological evidence of inflammatory response although a mild humoral Th-2 response to viral capsid proteins was detected. These findings have important implications with respect to therapeutic applications of rAAV.     

Cancer-associated retinopathy

Patients with systemic cancer may have a variety of ocular complaints. Most commonly these are metastases or adverse effects of therapy. Paraneoplastic syndromes, like cancer-associated retinopathy, rarely cause ophthalmic symptoms. We describe a patient with a malignant mixed mullerian tumor and cancer-associated retinopathy who had circulating serum antibodies to recoverin and cells positive for recoverin in the tumor. We discuss the typical clinical symptoms as well as the pathophysiology of this uncommon disorder.     

Pharmacokinetics and protein binding of cis-dichlorodiammine platinum (II) administered as a one hour or as a twenty hour infusion

Summary The pharmacokinetics of cis-dichlorodiamminoplatinum (II) (cisplatin) have been studied in seven patients, of whom four received the drug as a one hour infusion and three received it as a 20 h infusion. The patients receiving the drug over one hour exhibited biphasic clearance of total platinum with a rapid initial phase (8.7–22.5 min) and a prolonged second phase (30.5–106 h). Free (ultrafilterable) cisplatin was readily detectable in this group and was rapidly cleared (half-life about 22 min). The volume of distribution of the drug was 50.3–65.6 liters and it was 26.6–50% excreted in the urine in 48h. In the patients receiving the 20 h infusion, a more complex plasma elimination curve was seen, with the appearance of a secondary peak. Free drug was not detectable in these patients and they showed less urinary excretion (21.4–25.9% at 48 h) than the one hour group. Cisplatin was bound to several plasma proteins, including albumin, transferrin, and -globulin. The data indicate that cisplatin is retained in the body more extensively after a 20 h infusion than after a one hour infusion.     

Possible health care professional-to-patient HIV transmission. Dentists' reactions to a Centers for Disease Control report.

On July 27, 1990, the Centers for Disease Control reported possible transmission of the human immunodeficiency virus (HIV) from a dentist to a patient as a result of patient care. We surveyed a random national probability sample of 300 dentists with a 26-item survey in August and September 1990 to assess reactions to the report (response rate, 59%). Respondents tended not to believe the report (mean was 3.2, median 3.0, where 1 indicated "do not believe" and 7 indicated "believe"). Our sample also tended to believe that transmission of HIV from dentists to patients was unlikely in the future (mean was 2.0, median 2.0, where 1 indicated "not at all likely" and 7 indicated "very likely"). Fifty-one percent of our sample recommended that dentists infected with HIV should discontinue practice, while 38% recommended continuing practice with changes in procedures. Seventy-four percent believed patients should be told if their dentist was infected with HIV. In summary, dentists doubted the possibility of dentist-to-patient transmission of HIV and did not believe the Centers for Disease Control case report, but they did believe infected dentists should refrain from clinical work or modify their practice.