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Biomedical subjects

R Rosenberg

Publications and source records attributed to R Rosenberg.

At least 19 recordsLinked to original sources
PubMed1992

Random mating of natural Plasmodium populations demonstrated from individual oocysts.

DNA amplified from individual Plasmodium vivax oocysts, produced by feeding mosquitoes directly on naturally infected humans in Thailand, was used to study cross-mating of 2 polymorphs of the circumsporozoite (CS) gene, VK 210 and VK 247. Alleles were detected in matched blood parasites, sporozoites, and individual oocysts with oligoprobes specific to characteristic repeat units. Oocysts developing from 3 cases in which mixed alleles were present in the blood parasites had genotype frequencies, including hybrids, consistent with the Hardy-Weinberg equilibrium. There was apparently no barrier to hybridization of the 2 alleles nor a bias, as has been found in some laboratory experiments, favoring hybrid formation. These are the first measurements of cross-mating frequencies directly from natural Plasmodium infections and the first observations of genetic hybridization in P. vivax.

Alleles↗
PubMed1992

Development and evaluation of an enzyme-linked immunosorbent assay for Plasmodium vivax-VK247 sporozoites.

An enzyme-linked immunosorbent assay (ELISA) for the Plasmodium vivax-VK247 (variant) circumsporozoite (CS) protein was developed and evaluated using sporozoites produced by feeding mosquitoes on Thai patients with parasitologically confirmed P. vivax infections. The ELISA had a detection threshold of fewer than 50 sporozoites. Using this assay in conjunction with an ELISA for the VK210 polymorph, nearly 16% of the 235 P. vivax cases produced sporozoites positive only for the variant; 69% produced sporozoites positive only in the VK210 assay; and 15% were positive in both assays, indicating mixed infections. Twelve cases (5%) produced sporozoites negative in one assay and with unexpectedly low activity in the other ELISA, indicating the possibility of other CS protein polymorphs.

Amino Acid Sequence↗
PubMed1992

Effects of cetirizine, loratadine and terfenadine on histamine weal and flare reactions.

This randomised double-blind, placebo-controlled, cross-over study compared the effects of single oral doses of terfenadine 120 mg, cetirizine 10 mg, and loratadine 10 mg on experimentally induced weal and flare reactions. The areas of weal and flare induced by intracutaneous injections of histamine were measured using planimetry, weal thickness by A-scan pulsed ultrasound and erythema index by a device which measures the relative reflectance of red and green light. All three antihistamines suppressed the weal and flare area and weal thickness 3, 6, 12 and 24 h after dosing. At the usual currently recommended doses terfenadine and cetririzine were most effective after 6 h and were more potent than loratadine for the first 6 h of the study.

Administration, Oral↗
PubMed1992

Use of intraperitoneal chemotherapy for treatment of ovarian cancer.

Second line chemotherapeutic therapy following failure with Cis-platinum combined regimens for treatment of cancer of the ovary is discouraging. Similarly, results with the use of Cis-platinum combined regimens for patients with less than well debulked primary surgery are also discouraging. In an attempt to improve these results, a series of 57 patients were subjected to high dose Cis-platinum and AraC given intraperitoneally. 44 of these patients were those that had been subjected to a second look procedure after 8-12 months of Cis-platinum therapy and were found to have residual disease in the form of positive cytology or microscopic disease up to nodules of 1.5 cm in diameter. 13 of the patients, because of less than well-debulked surgical procedures, were also accepted for therapy. In all patients, a subcutaneously implanted catheter was introduced into the patient and the tube was tunneled through the subcutaneous tissue into the peritoneal cavity. Cis-platinum and AraC were introduced into the peritoneal cavity through this cutaneous line. Concurrently, with the administration of the intraperitoneal therapy, Sodium Thiosulfate was given intravenously for systemic protection from Cis-platinum toxicity. Treatments were given every three to four weeks and the number of courses varied from 3 to 8 for a total of 184 injections for the entire group. In seven of these patients distribution studies were carried out using radioactive sulfur colloids which were injected peritoneally prior to the first treatment and preceding each subsequent treatment in order to evaluate the anticipated distribution of the chemotherapeutic agents. Only 4 of the 44 patients in group 1 and 3 of the 13 patients in group 2 are alive without evidence of disease at the present time. The low success rate is believed due to the poor distribution of the chemotherapeutic agents after the first two or three injections. In most of the patients, by the third or fourth treatment, they were found to have developed loculated restricted areas with minimal distribution of the agents. This was also demonstrated by the distribution studies carried out with the sulfur colloid.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

The Pain Behavior Check List (PBCL): factor structure and psychometric properties.

The construct of "pain behaviors" as observable and measurable manifestations of pain occupies a central role in Fordyce's operant model of pain. The present study was designed to evaluate the multidimensional nature of the construct and to explore the psychometric properties of a newly developed self-report instrument called the Pain Behavior Check List (PBCL). Subjects were 126 chronic pain patients who completed an initial version of the PBCL and other standardized questionnaires as part of their evaluation by the West Haven VAMC. Factor analysis identified four factors labeled Distorted Ambulation, Affective Distress, Facial/Audible Expressions, and Seeking Help. Substantial reliability and stability estimates for the total PBCL and the subscales support the potential clinical and theoretical utility of the instrument.

Affect↗
PubMed1991

Subtyping panic disorder by major depression and avoidance behaviour and the response to active treatment.

In order to establish the clinical validity of currently used ways of subtyping panic disorder the predictive power of associated current avoidance behaviour and (secondary) major depression for the response to active treatment (alprazolam, imipramine) was tested. The analysis was based on the data from the Cross-National-Collaborative-Panic-Study. Limited support for validity evidenced by predicting drug response was found for grading panic disorder by the severity of avoidance behaviour; patients with panic attacks and agoraphobia are more responsive to imipramine (compared with alprazolam) when using the reduction of the total number of panic attacks (or of spontaneous panic attacks) as the outcome criterion; patients without any avoidance behaviour did better with alprazolam (compared with imipramine).

Adult↗
PubMed1991

Plasmodium vivax: gametocyte infectivity of naturally infected Thai adults.

Up to 200 laboratory reared Anopheles dirus mosquitoes were fed on each of 496 symptomatic Thai men who had patent, naturally acquired Plasmodium vivax gametocytaemia. Mean gametocyte densities were 455/mm3 (range: 0-3281), geometric mean oocyst number was 9 (0-142), mean frequency of infection was 43% (0-100%), and mean sporozoite number in salivary glands was 9525 (0-285,000). There was little relation between gametocyte density and either oocyst number or frequency of mosquito infection. There were, however, statistically strong positive correlations between oocyst numbers and frequency of infection, and between number of oocysts and number of salivary gland sporozoites. The data suggest that each oocyst contributed about 850 sporozoites to a gland infection.

Adult↗
PubMed1991

Validation criteria for panic disorder as a nosological entity.

Panic disorder (DSM-III, DSM-III-R) has been thoroughly studied in recent years. The main evidence for panic disorder as a nosological entity is reviewed, to delineate some important questions for future research. Validation criteria include epidemiological, phenomenological, genetic, neurobiological, pharmacological and behavioral findings. Biological, behavioral and psychodynamic considerations on etiology, pathogenesis and treatment are presented.

Alprazolam↗
PubMed1991

A trend analysis of changes during treatment of panic disorder with alprazolam and imipramine.

A total of 123 Scandinavian patients participated in a cross-national study of panic disorder. Twelve outcome measures, including number of panic attacks and phobias, have been used to describe changes in symptoms during treatment. This article gives a trend analysis of remission for each variable, analysing changes through the total period from baseline to week 8 and also changes in first and second half of this period, separately. Important differences between treatments are demonstrated. Alprazolam had an early effect on variables relating to panic attacks, such as severity of spontaneous attacks and avoidance, whereas imipramine showed a more delayed effect on global measures. Duration of illness, sex and the occurrence of depression in patients' history all affected the sequence of improvement.

Alprazolam↗
PubMed1991

Characteristics of panic disorder patients responding to placebo.

Forty-one panic disorder patients receiving placebo were investigated in a double-blind comparison of alprazolam, imipramine and placebo in panic disorder. A significantly higher drop-out rate was found in the placebo group than in the active treatment groups, but placebo response was found in 34% of the patients, defined as reduction of panic attacks to zero, and in 23%, defined as a score of greater than or equal to 8 on the Physician Global Improvement Scale (0-10 points). Several predictors of response to placebo were found. The responders had fewer panic attacks than the nonresponders at baseline. They also reported less psychopathology and were less help-seeking than the nonresponders. The implications for psychopathology and possible response to psychotherapy among responders and nonresponders are discussed. It is hypothesized that the responders show more signs of realistic processing of internal and external stimuli and fewer signs of subjective distress than the nonresponders. Responders will therefore probably be more responsive to psychotherapy than nonresponders.

Alprazolam↗
PubMed1991

Secondary depression in panic disorder: an indicator of severity with a weak effect on outcome in alprazolam and imipramine treatment.

Depressive symptoms are frequent in panic disorder. Among 123 Scandinavian patients participating in a placebo-controlled multicenter study of the efficacy of alprazolam and imipramine treatment in panic disorder, 21% and 23% fulfilled the DSM-III criteria of current and past major depressive episode, respectively, and 17% had dysthymia, even when melancholia and depressive episode with onset prior to the panic symptoms were excluded. According to a subscale of the Hamilton Rating Scale for Depression (HRSD) with higher validity than the full scale, 18% were classified as major depression and 57% as minor depression. A major finding was that patients with affective symptoms had higher scores on many psychopathological measures, including several Symptom Checklist-90 factors. Accordingly, secondary depression was suggested as an indicator of the severity of panic disorder. Depressed and nondepressed patients significantly improved on major outcome measures, but patients with current minor or major depression improved less. Although the sample was too small for detailed analysis of differences in drug efficacy, there was no indication that imipramine was more effective than alprazolam, considering scores on an HRSD subscale.

Alprazolam↗
PubMed1991

Alprazolam, imipramine and placebo treatment of panic disorder: predicting therapeutic response.

Factors that predicted the outcome of drug treatment (alprazolam or imipramine) of panic disorder were studied in a sample of 123 Scandinavian patients participating in a multicenter placebo-controlled 8-week trial. The attrition rate was 95% for alprazolam, 73% for imipramine and 46% for placebo. For the intention-to-treat and 3-week-completer samples, drugs and anxiety symptoms at baseline were the best predictors of improvement on the Global Improvement Scale and on symptom scales focusing on panic attacks, phobic behavior and anticipatory anxiety. For completers of the 8-week trial, only baseline scores predicted outcome. Generally, more severe symptoms at baseline predicted a worse outcome. A subsample of patients had a marked placebo response. Avoidance, sex, age, childhood psychopathology and previous treatment experience had no or only a weak impact on the outcome. The relationship between panic disorder and mood disorder is presented elsewhere.

Adult↗
PubMed1991

Some themes from the philosophy of psychiatry: a short review.

Some major themes in the philosophy of science are briefly reviewed, considering epistemological, ontological and ethical problems in modern psychiatry. A conception of realism at the ontological, empiricism at the methodological level and humanistic ethics is proposed. Meta-psychiatry is suggested as a theoretical discipline integrating clinical research methodology and philosophy of science.

Ethics, Medical↗
PubMed1991

The number of sporozoites produced by individual malaria oocysts.

Mature oocysts of Plasmodium falciparum and P. vivax from western Thailand were separated from the midguts of Anopheles dirus by collagenase digestion, and the number of sporozoites contained in each was counted. For 26 P. vivax oocysts, the mean count was 3, 688 (range 1, 954-5, 577) and for 14 P. falciparum, the mean count was 3, 385 (range 1, 359-4, 554); a single P. cynomolgi oocyst contained 7, 521. Counts were not significantly correlated with oocyst density, oocyst age, or identity of the examiner. There may have been strain differences in fecundity, particularly between P. falciparum lines maintained in vitro. Mosquitoes receiving a second, uninfected blood meal seven days after feeding on P. vivax-infected volunteers developed no additional sporozoites per oocyst, but had salivary glands 3.4 times as infected. By calculation, more than 20% of P. vivax sporozoites released from oocysts subsequently invade the salivary glands.

Animals↗
PubMed1991

Multicenter, crossover study of the efficacy and tolerability of terfenadine, 120 mg, versus cetirizine, 10 mg, in perennial allergic rhinitis.

In this 3-week randomized, double-blind, double-dummy multicenter, crossover study terfenadine, 120 mg, was compared with cetirizine, 10 mg, both given once daily in the treatment of perennial allergic rhinitis in sixty patients. Compared with the investigators' pretreatment assessment, both terfenadine and cetirizine significantly reduced the severity of all five symptoms (P less than .001). The two treatments were equally effective in controlling eye irritation, sneezing, nasal congestion and itchy nose, throat and palate, but cetirizine improved rhinorrhea more than terfenadine (P less than .05). Daily symptom assessments by the patients for the last 14 days of each treatment period showed no difference in efficacy between the two drugs for any of the symptoms. There were also no differences between the two drugs for overall assessments of efficacy or patient preference. Adverse events were recorded more frequently while taking cetirizine, with 14 attributable events compared with only five with terfenadine. Four of the cetirizine-related events were drowsiness or tiredness, but none was reported while patients were taking terfenadine. There was a tendency to increased weight (greater than 1 kg) with both treatments.

Adult↗