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Biomedical subjects

R Allen

Publications and source records attributed to R Allen.

At least 37 records · Page 2Linked to original sources
PubMed1991

Caring for the uninsured. The Oregon experience.

A commission was appointed by the governor of Oregon to develop strategies to increase health care access for the estimated 400,000 Oregonians who were without health insurance. Because of real or perceived financial barriers to access, these uninsured usually had more expensive, acute, and episodic care that resulted in the shifting of cost to the insured and in higher health care costs. After studying the problem for 6 months, the commission made specific recommendations that if fully implemented, would ensure access to health care for virtually all uninsured Oregonians. The recommendations support existing medical and insurance systems, foster public and private partnerships, and provide for the leveraging of federal Medicaid dollars in a favorable ratio to the state. The implementation of these recommendations should ultimately reduce costs and at the same time provide more care.

Delivery of Health Care↗
PubMed1990

Human neutrophils exhibit disparate chemotactic factor gene expression.

The evolution of acute inflammation from initiation through resolution is associated with the changing character of the infiltrating leukocytes. Recruitment of these leukocytes is dependent upon the generation of chemotactic factors that have either global or specific activity for a particular leukocyte. In this manuscript we present data demonstrating that human neutrophils can express mRNA for neutrophil chemotactic factor/interleukin 8 (IL-8), but fail to express mRNA for monocyte chemotactic protein (MCP-1). The expression of IL-8 was observed upon adherence or in response to stimulation with lipopolysaccharide. Maximal IL-8 antigenic production was noted at 24 hrs. These studies demonstrate a disparate expression of chemotactic cytokines by neutrophils.

Acute Disease↗
PubMed1990

The genetics of six neurotic disorders: a twin study.

Persons who had met criteria for specific anxiety or depressive neuroses during their lifetime were identified from a sample of 446 pairs of adult twins. Although there was a genetic contribution to neuroticism and to symptoms, there was no inheritance of specific disorders. This concurs with previous work in a sample from the same Australian Twin Registry and with those from a Norwegian sample. It is concluded that while there is a genetic contribution to the predisposing trait, and therefore to the intermittent appearance of symptoms, this contribution is obscured by the grouping of symptoms into diagnoses and by the help seeking which is a prerequisite to clinical diagnosis.

Adolescent↗
PubMed1990

Chronic toxicity/carcinogenicity studies of sulphamethazine in Fischer 344/N rats: two-generation exposure.

Fischer 344 rats were given 10, 40, 600, 1200 or 2400 ppm sulphamethazine (SMZ) in the diet to determine the toxicity and potential carcinogenicity of SMZ. There were 225 rats of each sex in the control groups and 135 of each sex in each dose group. Animals were killed after 3, 12, 18 or 24 months of continuous dosing. Body weights, feed consumption, clinical observations, organ weights and histopathology data were collected. A slight decrease in body-weight gain was observed in the high-dose groups compared with the controls. No difference in feed consumption was found between the control and dosed rats. Mortality was inversely related to SMZ dose, especially in females, that is mortality was highest in the controls and decreased as the dose of SMZ increased. A statistically significant dose-related increase in the incidence of follicular cell adenocarcinomas of the thyroid gland was observed in the animals killed after 24 months. The incidences of non-neoplastic lesions of the thyroid gland in treated animals were significantly higher among treated animals than among controls; these lesions included follicular cell hyperplasia, follicular cell focal cellular change and multilocular cysts. The incidences of retinal atrophy, atrophy of the acinar pancreas (males), and dilatation of the uterine lumen also increased with increasing SMZ dose.

Adenocarcinoma↗
PubMed1990

Effect of electrocautery on wound healing in midline laparotomy incisions.

The effect of electrocautery on midline fascial wound healing was studied in 108 Sprague-Dawley rats. Midline wound tensile strength was significantly reduced in fascia incised with the coagulation current compared with the cutting current or scalpel. In addition, tissue necrosis and inflammation as well as adhesion formation between the incision and abdominal viscera were more extensive in animals with incisions made using coagulation current. The results of the study indicate that the use of electrocautery coagulation current is associated with increased tissue damage and a significant reduction in the tensile strength of healing wounds. The contribution of electrocautery to wound complications in patients needs further evaluation.

Abdominal Muscles↗
PubMed1990

Snap-gauge compared to a full nocturnal penile tumescence study for evaluation of patients with erectile impotence.

A total of 50 consecutive male patients underwent simultaneous Snap-Gauge and full nocturnal penile tumescence evaluation with objective rigidity measurements to determine the correlation between the 2 studies. Subsequent clinical evaluation was conducted in patients in whom the 2 tests differed regarding diagnoses to determine which test more accurately predicted the clinical outcome. One patient was excluded from the study for technical reasons. Of 14 patients who had a normal Snap-Gauge evaluation, defined by breakage of all 3 bands, 12 (86%) had a normal and 2 (14%) had an abnormal nocturnal penile tumescence evaluation. A total of 28 patients failed to break any of the Snap-Gauge bands and 7 broke only 1 or 2 bands. Of these 35 patients with an abnormal Snap-Gauge study 14 (40%) had a normal and 21 (60%) had an abnormal nocturnal penile tumescence evaluation. In a subsequent clinical evaluation 1 of the 2 patients with a normal Snap-Gauge study and an abnormal nocturnal penile tumescence test reported continued inadequate sexual function and, subsequently, he received a penile prosthesis. Of the 14 patients with an abnormal Snap-Gauge study and a normal nocturnal penile tumescence test 11 were located and 8 were sexually active with adequate erections for intercourse without further medical treatment other than counseling. We conclude that the correlation between Snap-Gauge and nocturnal penile tumescence is not good, and that the nocturnal penile tumescence test is more accurate to determine the clinical diagnosis.

Adult↗
PubMed1990

Use of [11C]aminocyclohexanecarboxylate for the measurement of amino acid uptake and distribution volume in human brain.

A quantitative positron emission tomographic (PET) method to measure amino acid blood-brain barrier (BBB) transport rate and tissue distribution volume (DV) has been developed using 11C-labeled aminocyclohexanecarboxylate (ACHC), a nonmetabolized amino acid analogue. Dynamic PET data were acquired as a series of 15 scans covering a total of 60 min and analyzed by means of a two-compartment, two-parameter model. Functional images were calculated for the amino acid transport rate constants across the BBB and the amino acid DV in the brain. Results show [11C]ACHC to have an influx rate constant in gray matter of approximately 0.03-0.04 ml g-1 min-1, indicating a single-pass extraction fraction of approximately 5-7%. The intersubject coefficient of variation was approximately 15% while intrasubject variability of repeat scans was only slightly greater than 5%. Studies were performed in 15 young normal volunteer control subjects, 5 elderly controls, 7 patients with probable Alzheimer's disease, and one patient with phenylketonuria. Results indicate that [11C]-ACHC will serve as the basis of a method for measuring amino acid transport rate and DV in the normal and pathological human brain.

Adult↗
PubMed1990

Discrimination between HIV-1 and HIV-2-seropositive individuals using mouse monoclonal antibodies directed to HIV transmembrane proteins.

Mouse monoclonal antibodies directed against the transmembrane proteins of HIV-1 or HIV-2 provided site-directed, unambiguous discrimination between HIV-1 and HIV-2 antibody-positive sera, when employed in immunoassays as competitive probes against serum antibodies. These monoclonal antibodies mapped to epitopes outside of the well-characterized immunodominant regions (IDR) of the transmembrane proteins. The monoclonal competitive immunoassay was a superior method for discrimination compared with immunoprecipitation of metabolically radiolabeled HIV envelope glycoproteins, Western blot against viral envelope glycoproteins, or noncompetitive enzyme immunoassays employing HIV recombinant transmembrane proteins or synthetic IDR peptides as serological targets. The monoclonal competitive assay was not affected by antigenic cross reactivity or nonspecific reactivity exhibited by selected serum samples toward envelope proteins or peptides, respectively. Results of the monoclonal competitive immunoassay were supported by results of a peptide inhibition assay employing free IDR peptides in competition with IDR peptides on a solid support for binding of serum antibody. IDR peptide inhibition clearly demonstrated non-cross-reactive antigenic specificity of sera toward either the HIV-1 IDR or the HIV-2 IDR. The monoclonal competitive assay also identified samples containing antibody to both HIV-1 and HIV-2 transmembrane proteins. Analysis of these samples by IDR peptide inhibition indicated they contained two distinct, non-cross-reactive populations of antibodies, one directed to the HIV-1 IDR and the other directed to the HIV-2 IDR.

AIDS Serodiagnosis↗
PubMed1990

Transplacental transfer of aflatoxin in humans.

This study quantified aflatoxin (AFB1, AFG1 and AFQ1) by enzyme-linked immunosorbent assay in human cord sera obtained at birth and in serum obtained immediately after birth from the mother. The subjects of the study were residents of Songkhla, Thailand. Of the 35 samples of cord sera, 17 (48%) contained aflatoxin in concentrations from 0.064 to 13.6, mean 3.1 nmol/ml. By comparison only two (6%) of 35 maternal sera contained aflatoxin (mean 0.62 nmol/ml). These results demonstrate transplacental transfer and concentration of aflatoxin by the feto-placental unit which may be of biological importance. Aflatoxins are mutagenic, carcinogenic and teratogenic and cause immunosuppression in animals. The implications of these findings are potentially profound and deserve further study.

Aflatoxin B1↗
PubMed1990

Children with congenital anomalies: the preschool period.

To address a gap regarding the development of preschool children with physical congenital anomalies and the adaptational responses of their caretakers, 37 children with anomalies and 44 control children were assessed. Children were administered the Stanford-Binet and the Preschool Language Scale, and the children and their mothers were observed in a series of semi-structured situations. Performance on linguistic and intellectual tests was related to socioeconomic status, not to medical risk. Children with anomalies were more socially reticent and compliant than peers, and their mothers were more controlling and nonverbally active during a teaching task. Results are discussed in terms of Bell's lower-limit adaptational pattern.

Child, Preschool↗
PubMed1990

A comparison of parallel versus perpendicular placement of retention sutures in abdominal wound closure.

A new technique for placement of retention sutures is described. Twenty-five rats underwent midline laparotomy incision. The control group was closed with traditional placement of through-and-through retention sutures placed in a perpendicular direction to the wound. The experimental group was closed with retention sutures placed in a parallel direction to the wound as described below. Wound bursting strength was significantly (P less than 0.001) greater at one to five days in the experimental group compared with the control animals. In addition, inflammatory reaction and pressure necrosis were greater in the control group. It appears that parallel placement of sutures has less of a tendency to cut through tissue when subjected to the distracting forces on a midline wound.

Abdomen↗
PubMed1990

Phase-shifting effects of bright morning light as treatment for delayed sleep phase syndrome.

Bright light has recently been shown to have phase-shifting effects on human circadian rhythms. In this study we applied this effect to 20 patients with delayed sleep phase syndrome (DSPS) who were unable to fall asleep at conventional clock times and had a problem staying alert in the morning. In a controlled treatment study, we found that 2 h of bright light exposure in the morning together with light restriction in the evening successfully phase advanced circadian rhythms of core body temperature and multiple sleep latencies in these patients. This finding corroborates the importance of light for entraining human circadian rhythms.

Arousal↗
PubMed1989

Interpersonal behavior and cardiovascular reactivity in pharmacologically-treated hypertensives.

This study examined the interpersonal behavior and concomitant cardiovascular reactivity (CVR) of hypertensive patients whose resting blood pressure was controlled by antihypertensive medication. Thirty hypertensive and 30 normotensive subjects matched for age, sex and occupational status were recruited from an industrial setting. The groups were compared on measures of interpersonal behavior, blood pressure and heart rate while they engaged in both role-played (RP) and naturalistic interactions (NI) requiring positive and negative assertion. Interpersonal behavior of the groups was generally similar, with two exceptions: hypertensives made fewer requests for new behavior in the negative RP and verbalized more praise statements in the positive NI. There were no differences between the groups on measures of CVR during interpersonal interactions. Overall effectiveness during scenes requiring negative assertion was associated with increased cardiovascular reactivity, especially for hypertensives. The interpersonal behavior and cardiovascular responses of patients taking beta-blocker medication did not differ from those taking diuretics. These findings are discussed with regard to methodological considerations pertinent to the assessment of interpersonal behavior and the issue of heterogeneity among hypertensives.

Adrenergic beta-Antagonists↗
PubMed1989

Meta-analysis of placebo-controlled studies of the efficacy of Epogam in the treatment of atopic eczema. Relationship between plasma essential fatty acid changes and clinical response.

Gamma-linolenic acid in the form of a particular variety of evening primrose oil (Epogam) has been reported of value in the treatment of atopic eczema. Nine controlled trials of evening primrose oil were performed in eight centres. Four of the trials were parallel and five cross-over. Doctors and patients assessed the severity of eczema by scoring measures of inflammation, dryness, scaliness, pruritus and overall skin involvement. Individual symptom scores were combined to give a single global score at each assessment point. In the analysis of the parallel studies, both patient and doctor scores showed a highly significant improvement over baseline (P less than 0.0001) due to Epogam: for both scores the effect of Epogam was significantly better than placebo. Similar results were obtained on analysis of the cross-over trials, but in this case the difference between Epogam and placebo in the doctors' global score, although in favour of Epogam, failed to reach significance. The effects on itch were particularly striking. There was no placebo response to this symptom, whereas there was a substantial and highly significant response to Epogam (P less than 0.0001). When the improvements, or otherwise, in clinical condition were related to changes in plasma levels of dihomogammalinolenic and arachidoni acids, it was found that there was a positive correlation between an improvement in clinical score and a rise in the fatty acid levels.

Adolescent↗