Phorbol esters down-regulate transcription and translation of the CD4 gene

This study investigated the effects of PMA on biosynthesis and transcription of the CD4 molecule and gene in order to define mechanisms resulting in reduced cell surface expression of the CD4 molecule after treatment with PMA. Cells treated with PMA showed reduced biosynthesis of the CD4 molecule but not of class I HLA molecules. Furthermore, PMA treatment resulted in reduced steady-state levels of CD4 mRNA and inhibition of the relative rate of transcription of the CD4 gene. Cells expressing transfected CD4 cDNA gene products modulated in response to PMA, however, re-expressed CD4 earlier than cells expressing the product of the wild-type CD4 gene. These data suggest that the cell surface expression of the CD4 molecule is probably down-regulated at the level of the protein, as well as the gene, and that inhibition of transcription may affect the kinetics of CD4 expression. These observations provide further insight into the mechanisms by which HIV affects expression of CD4.

Does stimulus context affect loudness or only loudness judgments?

Marks (1988) reported that when equal-loudness matches were inferred from magnitude estimates of loudness for tones of two different frequencies, the matches were affected by changes in the stimulus intensity range at both frequencies. Marks interpreted these results as reflecting the operation of response biases in the subjects' estimates; that is, the effect of range was to alter subjects' judgments but not necessarily the perception of loudness itself. We investigated this effect by having subjects choose which of two tone pairs defined the larger loudness interval. By using tones of two frequencies, and varying their respective intensity ranges, we reproduced Marks' result in a procedure devoid of numerical responses. When the tones at one frequency are all soft, but the tones at the other frequency are not all soft, cross-frequency loudness matches are different from those obtained with other intensity range combinations. This suggests that stimulus range affects the perception of loudness in addition to whatever effects it may have on numerical judgments of loudness.

Neonatal body proportionality and body composition after in utero exposure to cocaine and marijuana

The relationship of maternal use of marijuana and cocaine during pregnancy to measures of neonatal body proportionality and body composition was assessed in a multiethnic sample of 1082 newborn infants. Maternal use of marijuana and cocaine during pregnancy was ascertained by self-report and by an enzyme-multiplied immunoassay technique for screening of urine samples obtained prenatally and again post partum. After each substance was analytically controlled for use of the other and for other potentially confounding variables, detection of marijuana metabolites in maternal urine was associated (p less than 0.05) with depressed mean arm muscle circumference and nonfat area of the arm but not with any measure of neonatal fatness. In contrast, detection of cocaine in maternal urine was associated (p less than 0.05) with decrements of subscapular fat folds and of the fat and nonfat areas of the arm. Although both substances were associated with depressed birth weight, there was no decrement of neonatal ponderal index or of the arm circumference/head circumference ratio in association with exposure to either substance. We conclude that both marijuana exposure and cocaine exposure during pregnancy are associated with symmetric intrauterine growth retardation, but that deficits are in differing compartments of intrauterine growth. These findings suggest that marijuana may retard fetal growth through maternal-fetal hypoxia, whereas cocaine may alter nutrient transfer to the fetus and fetal metabolism.

Formulation of tissue conditioners

Dental tissue conditioners are compliant gels, formed in situ under a denture from a polymer powder and a plasticizer system. Hitherto, the powder has been poly(ethyl methacrylate) and the liquid a phthalate/ethanol mixture. These materials are temporary, because they harden from plasticizer leaching. The current work has been aimed at producing material with extended oral lifetimes. A range of n-butyl/ethyl methacrylate copolymers have been studied, together with various ester-ethanol liquid systems, with respect to gelation behaviour with various alcohols and esters, viscoelastic behaviour of the set gels, and water extraction. Materials based on poly(ethyl methacrylate) show that gelation speed depends upon particle size, and the degree of ball milling of the powder, and the molar volume of the plasticizer. Systems based on n-butyl/ethyl methacrylate copolymers need less or no ethanol in the liquid system, although gelation speed is very temperature dependent. The gels from these last materials are more compliant, and retain their compliance longer in aqueous media than those based on poly(ethyl methacrylate).

Soft prosthesis materials based on powdered elastomers

A new class of soft prosthesis material has been developed, based on the combination of a powdered elastomer and a methacrylate monomer that polymerizes to an elastomer. Such systems are processable by conventional dental technology. This principle avoids the use of plasticizers. Natural rubber, butadiene styrene and butadiene acrylonitrile elastomers have been used, together with a number of higher alkyl methacrylates (C8-C13) and 2-ethoxyethyl methacrylate. Such systems have been evaluated with respect to mechanical properties, including tear strength, adhesion to denture base poly(methyl methacrylate), water sorption and visco-elastic properties. A number of potentially viable systems have emerged, which may be useful in external prostheses. Many have high long-term water absorption, which makes questionable their long-term usefulness interorally. Nevertheless, there is still considerable scope for development in this area.

Perioperative rate-related silent myocardial ischemia and postoperative death

A case is presented that demonstrates heart rate (HR)--related silent myocardial ischemia occurring preoperatively, subsiding intraoperatively, then recurring and leading to a post-operative cardiac death in a patient undergoing peripheral vascular surgery. This case illustrates that patients may have an ischemic threshold for HR whereby recurrent depression of the ST segment may occur during increase of HR to rates as low as 80 to 85 beats per minute (bpm), even in the absence of acute blood pressure (BP) changes. Myocardial ischemia may be HR related; however, the authors are not aware of a case that demonstrates repeated episodes of rate-related ischemia occurring at HRs well below the 100 bpm traditional definition of tachycardia. The authors conclude that patients at risk for perioperative myocardial ischemia should be identified and the hemodynamic management of these patients should include control of HR. This implies control of the physiologic variables that influence HR, along with the use of beta-adrenergic blockers. This case also demonstrates the value of Holter monitoring for ischemia, which, when done preoperatively, can detect patients at risk for unfavorable cardiac outcomes. Ischemia monitoring also may be useful during the intraoperative and postoperative periods, a time when ischemia is often silent and undetected. The early recognition of ischemia would allow for anti-ischemic interventions, which could decrease the morbidity and mortality of patients at risk for perioperative cardiac complications.

Antituberculous drug resistance in central Haiti

To determine the prevalence of antituberculous drug resistance in Haiti, we conducted a 1-yr survey in a central district. From a bacillary positive (smear and/or culture positive) case rate of 80/100,000, there were 282 patients from whom Mycobacterium tuberculosis was cultured. Each isolate was packaged and delivered to Canada where speciation and drug susceptibility testing were performed. Reported resistances are those using the proportions method (Laboratory Center for Disease Control, Ottawa, Canada). Resistance to one or more drugs was found in 22% of isolates. Age was the most important predictor of resistance in Haiti; resistance rates for age groups less than 14, 14 to 29, 30 to 44, greater than or equal to 45 were 8, 19, 22, and 31%, respectively. In patients not known to have received antituberculous drugs in the past, resistances were isoniazid (19%), streptomycin (5%), ethambutol (2%), ethionamide (2%), rifampin (1%). We conclude that antituberculous drug resistance is prevalent in Haiti, especially in older age groups, and that in persons with no known antituberculous drug use in the past, resistance to isoniazid is significant.

A double-blind, placebo-controlled study of oral acyclovir in postherpetic neuralgia

Twenty-one patients with postherpetic neuralgia of two- to 84-months duration participated in a double-blind, placebo-controlled study of oral acyclovir. Pain perception was assessed with the Melzack Pain Questionnaire at baseline and at two-to six-week intervals during the ensuing six months. Clinically significant pain reduction occurred in eight patients: four received acyclovir, and four received a placebo. Several treatment strategies have been advocated for relief of postherpetic neuralgia. Results of the present study demonstrate the need for a double-blind, placebo-controlled paradigm to substantiate the efficacy of new clinical approaches. The same caveat applies to the more common syndromes encountered in psychiatric practice.

Maternal depressive symptoms during pregnancy, and newborn irritability

Maternal depression is associated with a wide range of adverse outcomes for children, including poor mother-infant interactions at 3 months post-partum. The aim of this study is to determine whether maternal depressive symptoms during pregnancy are associated with neonatal neurobehavioral functioning, as measured by the Neurologic and Adaptive Capacity Scale. The study population consists of 1,123 mothers and their term infants who were participants in a larger study of maternal health and infant outcomes. Women were administered the Center for Epidemiologic Studies-Depression (CES-D) questionnaire for depressive symptoms during their pregnancy. Their infants were subsequently assessed by a pediatrician blind to their CES-D scores. The CES-D score was associated with unconsolability and excessive crying (p less than 0.01). The higher the mother's CES-D score, the more likely it was that the infant would be unconsolable or cry excessively. Mothers with CES-D scores at the 90th percentile were 2.6 times more likely to have unconsolable newborns, compared with women with CES-D scores at the 10th percentile (95% C.I. = 1.54, 4.23). When potentially confounding variables, such as cigarette smoking, alcohol, marijuana, and cocaine use, poor weight gain, income, birth weight, and other drug use, were controlled, the relationship between CES-D score and newborn unconsolability and excessive crying remain unchanged. The results of this study suggest that the relationship between early childhood problems and maternal depressive symptoms may be part of a sequence that starts with depressive symptoms during pregnancy.

Paget's disease of bone and previous pet ownership in the United States: dogs exonerated

Paget's disease of bone is currently believed to be the result of a paramyxovirus infection of osteoclasts. Previously reported immunohistological data have suggested that a virus resembling either the measles virus or a respiratory syncytial virus is the probable causative agent, but no organism has been isolated or definitively identified to date. A recent study reporting an increased exposure to dogs during childhood and adolescence in a small series of cases from the North West of England proposed that a canine virus, possibly distemper, might be the primarily infectious agent. To study this hypothesis further, we examined prior dog and cat ownership from childhood through adulthood in 433 cases of Paget's disease and an equal number of matched controls living in the US. We found no differences related to prior pet ownership. We conclude that past dog (or cat) ownership is not a risk factor for the development of Paget's disease.

Influence of single and multiple doses of oral ranitidine on the gastric transit of an indigestible capsule in humans

The effect of single and multiple doses of ranitidine on the gastric residence time of an indigestible pH-sensitive radiotelemetric device, the Heidelberg capsule, was evaluated in 12 healthy men (mean age, 29 +/- 8 years) in a placebo-controlled, randomized, crossover study. Each subject received 150 mg ranitidine or placebo orally 2 hours before administration of the Heidelberg capsule. A 500 kcal standardized breakfast was served 1/2 hour before the capsule was administered. Gastric pH was monitored at 15-minute intervals, until pyloric passage (pH increase greater than or equal to 3 U) of the Heidelberg capsule was observed. Blood samples (n = 12) were collected 0 to 8 hours after administration of drug or placebo. The subjects continued to receive ranitidine or placebo b.i.d. for 7 days and returned on day 8 for a similar evaluation. After a 1-week washout period, the subjects received the alternative treatment. The mean (+/- SD) gastric residence time of the Heidelberg capsule was significantly decreased after both single and multiple doses of ranitidine compared to placebo (3.1 +/- 0.9 versus 3.8 +/- 1.1 hours, p less than 0.02; and 2.9 +/- 0.74 versus 3.9 +/- 0.9 hours, p less than 0.005, n = 9). Gastric residence time was not determined in three subjects who showed unusually slow gastrointestinal motility after both placebo and ranitidine. Mean AUC(0-8 hr) and AUC(0-infinity) were significantly increased, whereas Cmax, tmax, and t1/2 remained unchanged after 7 days of ranitidine b.i.d. treatment. No ranitidine double-peak profile or linear pharmacokinetic-pharmacodynamic relationship was identified.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the need for follow-up in an out-patient clinic

We have identified 164 patients regularly attending a chest clinic whose condition had been defined as stable on the basis of clear-cut criteria. These patients were randomly allocated to either routine follow-up at 3 monthly intervals (the 'follow-up' group) or annual follow-up (the 'discharge' group). After 1 year, on the basis of a questionnaire sent to the patients' general practitioners, there were no significant differences in outcome between the two groups apart from a just-significant increase in deaths in the 'follow-up' group. Nevertheless, at the conclusion of the trial clinic doctors felt that only 45% of patients and general practitioners that only 27% of patients should be discharged from the clinic. At the conclusion of the study patients in the 'discharge' group were significantly more likely to feel that they had been attending too infrequently and that their condition had worsened, although the latter was not borne out by objective data. We suggest that all these patients could have been discharged from the clinic without any difference in outcome. This study highlights the reluctance of clinic doctors and general practitioners to consider and effect the discharge of stable patients from routine clinic attendance.

Partial hospitalization: an update

As a treatment modality for serious mental disorders, partial hospitalization has been proven to have therapeutic and economic advantages. However, it has relatively low utilization and poor third-party reimbursement compared to the more traditional outpatient and inpatient treatments. The authors provide a review and update of the definitions, historical development, models, staffing, and referral patterns of partial hospitalization. They comment on the role of the psychiatrist as a member of the multidisciplinary team in this treatment setting.

Intensity discrimination and loudness for tones in broadband noise

In two previous papers (Parker & Schneider, 1980; Schneider & Parker, 1987), we developed a model, based on Fechner's assumption, which successfully predicted the relationship between loudness and intensity discrimination for tones presented in quiet and in notched noise. In the present paper, pure-tone intensity-increment thresholds and loudness matches were determined for several levels of a standard tone in the presence of a broadband masker whose spectrum level was set to 35 dB below that of the standard tone. The model was unable to relate loudness to intensity discrimination under these conditions. Thus, the spectral composition of the masker affects the relationship between loudness and intensity discrimination in ways that cannot be accounted for by the model.

Jitteriness in full-term neonates: prevalence and correlates

The prevalence and correlates of jitteriness were evaluated in a sample of 936 healthy full-term infants. Jitteriness was seen in 44% of this sample: 23% were classified as mildly jittery, 8% as moderately jittery, and 13% as extremely jittery. Jitteriness was seen most commonly in infants who were sleepy or active and least commonly in infants who were quietly wakeful during the neonatal examination. Jittery infants were more likely to be difficult to console when crying (P less than .01) and less visually alert (P less than .001) than were nonjittery infants. Jitteriness was seen more commonly in slightly smaller (P less than .05) and shorter (P less than .001) infants, in those more than 12 hours old (P less than .01), and in those not exposed to general anesthesia (P less than .05). In an expanded sample of 1054 healthy and sick full-term infants, jitteriness was observed more commonly in neonates who had been exposed prenatally to maternal marijuana use (P less than .01), but not to cocaine use (P = .1), and whose mothers had a positive postpartum urine assay for marijuana (P less than .05) or cocaine (P = .06). The magnitude of these drug effects, however, was small. These findings have important implications for the early parent-infant relationship, pediatric practice, and future research.

Double-blind, crossover placebo controlled trial of selegiline in Parkinson's disease--an interim analysis

The response to selegiline was assessed in ten (2 females, 8 males) idiopathic parkinsonian patients with the wearing off response. Selegiline was compared to placebo in each patient in a double blind crossover study carried out over ten months. After 16 weeks of therapy selegiline significantly prolonged response to levodopa, extending response to 3 hours (p less than 0.05) in most patients and to 4 hours (p less than 0.001) in some patients. Baseline scores (zero time: 12 hours after their previous dose of medication) were also significantly better after selegiline therapy (p less than 0.05). Selegiline did not improve peak response (1 hour after medication) to levodopa indicating that these patients were on optimum therapy prior to receiving selegiline. Adverse effects (nausea (2), dyskinesia (2), fear reaction (1) and postural dizziness (1] occurred in 5 patients during the trial.

A ration of care, a measure of doubt

With limited dollars and skyrocketing costs, Medicaid programs around the country are feeling the squeeze. While some hope to guarantee basic health services by withholding access to certain high-ticket procedures, the question remains: Should we deny any level of care to the poor?