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Biomedical subjects

D Morrow

Publications and source records attributed to D Morrow.

At least 37 records · Page 2Linked to original sources
PubMed1993

The time-course of alcohol impairment of general aviation pilot performance in a Frasca 141 simulator.

This study examined the time-course of alcohol impairment of general aviation pilot simulator performance. We tested 14 young (mean age 25.8 years) and 14 older (mean age 37.9 years) pilots in a Frasca 141 simulator during alcohol and placebo conditions. In the alcohol condition, pilots drank alcohol and were tested after reaching 0.10% BAL, and then 2, 4, 8, 24, and 48 h after they had stopped drinking. They were tested at the same times in the placebo condition. Alcohol impaired overall performance. Alcohol impairment also depended on the order in which subjects participated in the alcohol and placebo sessions, with larger decrements for the alcohol-placebo order than for the opposite order. To examine the influence of alcohol independent of session order effects, we compared performance in the first alcohol session with performance in the first placebo session. This analysis showed that alcohol significantly reduced mean performance in the alcohol condition at 0.10% BAL and at 2 h. In addition, alcohol increased variability in performance in the alcohol session from 0.10% BAL to 8 h, suggesting that some subjects were more susceptible to alcohol than others. Older pilots tended to perform some radio communication tasks less accurately than younger pilots.

Adult↗
PubMed1992

Clinical effect of subgingival chlorhexidine irrigation on gingivitis in adolescent orthodontic patients.

Twenty-three adolescent orthodontic patients with gingivitis affecting all banded first molars volunteered for the study. Three measures associated with gingivitis (papilla bleeding index, plaque index, and probing depth) were recorded at four sites for all four molars. A single application of subgingival irrigation with 0.12% chlorhexidine digluconate or isotonic saline was performed for 5 seconds at each site. As determined by coin toss, the first molars on the right or left side of the mouth received either chlorhexidine or saline irrigation. The papilla bleeding index, plaque index, and probing depth were recorded before the treatment and subsequently at 2 weeks and then 4 weeks. The gingival bleeding as determined by papilla bleeding index, was virtually eliminated in 4 weeks by a single application of subgingival irrigation with either chlorhexidine or saline. However, there was no significant reduction in pocket depth or plaque index. In addition, no significant difference between the effect of chlorhexidine or saline was found for any of the outcome measures.

Adolescent↗
PubMed1991

Molecular characterization of the gene encoding a rice endosperm-specific ADPglucose pyrophosphorylase subunit and its developmental pattern of transcription.

The gene encoding a rice endosperm-specific ADPglucose pyrophosphorylase (AGPP) subunit was isolated and its structure determined by nucleotide (nt) sequencing. A comparison of the genomic and cDNA nt sequences revealed a complex gene structure with ten exons and nine introns spanning over 6 kb. The exons ranged in size from 293 to 99 nt and the introns were between 1435 and 84 nt in size, with the first intron being the largest. All of the intron splice sites, except intron-2, contained GT/AG borders and were similar to the published splice site consensus sequences. Intron-2 had CA/CC borders at the 5' and 3' ends, but sequences adjacent to the splice site borders shared homology to the splice site consensus sequence, suggesting that the overall splice region, rather than the specific GT/AG sequence, determines the splice site. Several sequence motifs which may play a role in the regulation of plant genes were evident upstream from the transcriptional start point. Analysis of the developmental pattern of expression revealed a maximum level of mRNA transcripts for AGPP at five days after flowering coincident with starch accumulation. This result suggests that starch biosynthesis is controlled at the transcriptional level during seed development.

Amino Acid Sequence↗
PubMed1991

Mandatory parental involvement prior to adolescent abortion.

The issue of parental involvement in an adolescent's decision to abort a pregnancy is complex and controversial. Consequently, the impact of legislation to mandate parental involvement is reviewed. Although the costs of such legislation are high, there are at least three important clinical benefits. First, a legal mandate will require many adolescents who would not otherwise involve their parents in this decision process to seek their counsel and emotional support. Second, parent's responsibility for the actions of their adolescent children is acknowledged within the legal system. Third, family unity may be promoted by allowing parents and adolescents an opportunity to deal more openly with the causes and implications of the pregnancy.

Abortion, Legal↗
PubMed1991

Elders' schema for taking medication: implications for instruction design.

We examined whether elders share a schema for taking medication and if instructions are better understood and recalled when organized to match this pre-existing schema. Experiment 1 investigated if elders agree on how to group medication information into categories, and if they agree on an order for arranging this information. Elders tended to organize information into three categories, arranged in the following order: General information about the medication (purpose), How to take (dose and schedule), and Outcomes (emergency information). In Experiment 2, we compared instructions that were: (a) compatible with this schema in terms of grouping and order, (b) compatible only in terms of grouping (category order was changed), and (c) incompatible, not matching the model in terms of either grouping or order. Memory for medication information increased with the compatibility of the instructions to the model. Elders also preferred the more compatible instructions. The findings suggest that elders possess a schema for taking medication, which they use to understand and recall medication instructions.

Aged↗
PubMed1991

Alcohol, age, and piloting: judgement, mood, and actual performance.

We have previously described acute and carry-over effects of alcohol on young and older pilots' performance. In the present paper we report the effects of alcohol and age on self-assessment of performance and mood in the same study. Young and older pilots flew in a simulator during an alcohol and placebo condition. In the alcohol condition, they flew after reaching .04 g/dL (.04%) BAL, after .10% BAL, and then 2, 4, 8, 24, and 48 h after .10% BAL (they flew at the same times in the placebo condition). They rated confidence in ability to fly, mood, alertness, and intoxication before each flight, and perceived workload and performance after each flight. As reported in Morrow et al., alcohol had both acute and carry-over effects for 8 h on actual flight performance, with greater acute impairment for older pilots. The present study reports that these older pilots tended to be more aware than the young pilots of acute and carry-over alcohol impairment out to 4 h. By 8 h, however, all pilots were unaware of impairment. Alcohol also had a biphasic effect on mood, which increased on the ascending limb and decreased on the descending limb of the BAL curve.

Adult↗
PubMed1990

The influence of alcohol and aging on radio communication during flight.

This study finds that alcohol and pilot age impair radio communication during simulated flight. Young (mean age 25 years) and older (mean age 42 years) pilots flew in a light aircraft simulator during alcohol and placebo conditions. In the alcohol condition, pilots drank alcohol and flew after reaching 0.04% BAC, after reaching 0.10% BAC, and then 2, 4, 8, 24, and 48 h after they stopped drinking at 0.10% BAC. They flew at the same times in the placebo condition. Alcohol and age impaired communication-based and overall flying performance during and immediately after drinking. Most important, alcohol and age cumulatively impaired performance, since older pilots were more impaired by alcohol. Notably, performance was as impaired 2 h after reaching 0.10% BAC as it was at 0.10% BAC. Moreover, overall performance was impaired for 8 h after reaching 0.10% BAC.

Aging↗
PubMed1988

The Y chromosome from autoimmune BXSB/MpJ mice induces a lupus-like syndrome in (NZW x C57BL/6)F1 male mice, but not in C57BL/6 male mice.

The Y chromosome of the BXSB mouse has been shown to be responsible for the acceleration of lupus-like autoimmune syndrome in inbred BXSB mice and in their F1 hybrids with NZB or NZW mice. To further define the role of this as yet unidentified gene linked to the BXSB Y chromosome, designated Yaa (Y chromosome-linked autoimmune acceleration), the Y chromosome was transferred from the BXSB strain to nonautoimmune C57BL/6 (B6) mice. The effect of the Yaa gene on the autoantibody formation and the development of glomerulonephritis was investigated in B6 mice and in their F1 hybrids with NZW mice. The presence of the BXSB Y chromosome was not able to induce significant autoimmune responses in B6 mice. However, (NZW x B6)F1 males bearing the BXSB Y chromosome developed a severe lupus-like autoimmune syndrome, as documented by the production of anti-DNA antibodies and gp70-anti-gp70 immune complexes and the development of lethal lupus nephritis. Both sexes of (NZW x B6)F1 hybrids without the BXSB Y chromosome were essentially normal. Our results suggest that (a) the BXSB Y chromosome by itself is not sufficient to initiate autoimmune responses in nonautoimmune B6 mice, and (b) it is able to induce autoimmune responses in mice potentially capable of developing the disease, but whose autosomal abnormality by itself is not sufficient to develop autoimmune diseases.

Animals↗
PubMed1988

Adherence and medication instructions. Review and recommendations.

Prescription medication nonadherence among the elderly is a serious medical problem. Nonadherence is primarily caused by poor communication between health professionals and elderly patients. More specifically, nonadherence often reflects the inability of patients to understand and remember their medication instructions. Therefore, adherence can be increased by designing instructions that enable elders to easily construct a clear and simple mental model of how to take their medication. Inexpensive microcomputer-based hardware and software makes it possible for pharmacists to provide elderly patients with effective instructions.

Aged↗
PubMed1986

Further evidence that "malignant angioendotheliomatosis" is an angiotropic large-cell lymphoma.

Malignant angioendotheliomatosis is a rare, generally fatal disease characterized by a multifocal proliferation of neoplastic mononuclear cells within the lumens of small blood vessels. Although the disease primarily involves the vasculature of the skin and central nervous system, vascular involvement of other organs may occur and may produce a variety of clinical findings. Some early investigators concluded that malignant angioendotheliomatosis was a neoplasm of endothelial cells, but recently others have suggested that it is of hematopoietic origin. We have studied three patients with the disease and have characterized the immunophenotype of the neoplasm on cryostat-cut fresh-frozen tissues. A detailed antigenic phenotyping of neoplastic lymphoid cells showed that one patient had the immunophenotype T11+, Leu-1+, Leu-3+, Leu-2+, B1-, B2-, SIg-, LN1-, LN2-, the predominant phenotype for peripheral T-cell lymphoma; the others had T11-, Leu-1-, Leu-3-, Leu-2-, B1+, B2+, SIg+, LN1+, LN2+, consistent with a B-cell-derived lymphoma. On the basis of our results, we suggest that angiotropic (intravascular) large-cell lymphoma would be more appropriate than malignant angioendotheliomatosis as a name for this disease.

Adult↗
PubMed1986

Pathogenesis of the delayed phase of Rauscher virus-induced thrombocytopenia.

BALB/c (H-2d) mice infected with Rauscher murine leukemia virus (RMuLV) developed two phases of thrombocytopenia: an acute phase, probably due to direct virus-platelet interactions, and a delayed phase, starting 2 to 3 wk after virus injection, which was associated with the infection of megakaryocytes by RMuLV and with the expression of RMuLV gp70 and p30 antigens on platelet membranes. This study was concerned with the pathogenesis of this second phase of thrombocytopenia. During this period, the number of marrow megakaryocytes was increased. A peripheral platelet destruction was further indicated by reduced platelet life span. It was shown that radiolabeled platelets, either normal or infected, were submitted to a more rapid clearance in infected recipients than in normal recipients. This might be due to the splenomegaly observed in infected recipients. However, the immediate clearance of gp70+ platelets was more accelerated in infected recipients with high titers of serum anti-gp70 antibodies than in infected recipients without detectable serum anti-gp70 antibodies. In addition, the passive transfer of anti-RMuLV serum to normal BALB/c mice induced a rapid and specific clearance of previously injected radiolabeled platelets expressing RMuLV antigens. In H-2d mice, viral gp70 antigen expression on platelets correlated with the development of delayed thrombocytopenia; but H-2k strains of mice, although susceptible to RMuLV and expressing RMuLV-related antigens on their platelets, did not develop any anti-RMuLV antibodies nor any delayed thrombocytopenia. These results suggest that specific clearance of gp70+ platelets in the presence of significant amounts of serum antiviral antibodies and nonspecific hypersplenism play a role in the development of delayed thrombocytopenia in RMuLV-infected mice.

Animals↗
PubMed1984

Isolation of Exophiala jeanselmei associated with esophageal pathology--three cases, laboratory and clinical features.

Exophiala jeanselmei was isolated from three esophageal cultures over an 11-month period at Lutheran General Hospital. We believe this provides evidence for a new site of isolation, since previous reports of the organism's incidence were confined to skin and lung. Case 1 is an eight-year-old female with a three-year history of gagging and vomiting. Esophagoscopy revealed a mass biopsied as vegetable material. Case 2 is a 66-year-old retired male with a history of obesity, diabetes and spinal stenosis. Following back surgery, the patient developed odynophagia. Esophageal biopsies showed ulceration and bacterial colonies with no evidence of fungus. Case 3 is a 62-year-old male gardener who is also a nail biter. Esophagoscopy revealed a gastro-esophageal stricture with reflux and evidence of a hiatus hernia. Material biopsied was consistent with Barrett's esophagus and evidence of fungi was seen. The esophageal mass of case 1 and the esophageal brushings of case 2 and 3 grew E. jeanselmei. Aspiration, reflux, and mechanical disruption of the esophageal mucosa are possible predisposing factors in colonization of esophageal lesions by this ubiquitous, normally low virulence organism.

Aged↗
PubMed1984

Care of low-birthweight and sick newborn infants in community hospitals. Effect of an education program.

We studied the effect of an education program on newborn care practices, documented by chart review, in nine community hospitals in central Pennsylvania. Following a visit to each hospital, specific recommendations were made and courses were offered at the regional center. A follow-up review of newborn charts showed significant improvement in newborn care. This kind of educational program, particularly if directed at identified problems in individual hospitals, appears to be effective. In addition, chart reviews can provide the information necessary for assessing both care practices and the effect of an educational program.

Delivery of Health Care↗
PubMed1984

Villus atrophy and malabsorption in a rhesus monkey.

Villus atrophy involving the proximal small intestine was diagnosed in a rhesus monkey (Macaca mulatta) at necropsy. A juvenile, male, captive-born monkey exhibited weight loss, hypoalbuminemia, patchy alopecia, eosinophilia, and vomiting. D-xylose absorption was impaired. Contrast radiography revealed thickening of the gastric and intestinal walls, gaseous distension of intestines and a rapid transit rate. There was no clinicopathologic evidence of involvement of organs other than the gastrointestinal tract. The intestinal villus atrophy was similar in distribution and morphology to that of human celiac disease.

Animals↗
PubMed1983

Use of prostaglandin F2 alpha in the treatment of unobserved estrus in lactating dairy cattle.

A field trial was conducted to evaluate the use of prostaglandin F2 alpha (PGF2 alpha) (lutalyse)a in lactating dairy cattle with unobserved estrus in the presence of a functional corpus luteum (CL) and clinically normal reproductive tract. Seventy-three Holstein and 9 Jersey cows, weighing between 340.0 and 772.7 kg, were allotted to treatment and control groups. All treated cows were inseminated within 80 hours after treatment as assigned by this trial. Control cows were inseminated at the first observed estrus. Of the treated cows, 50% showed estrus within 80 hours after treatment. In this trial, 96% of the treated cows and 92% of the control cows were determined to have at least 1 functional CL on the day of treatment. For the treatment group and the control group, mean serum progesterone concentrations were 4.1 ng and 3.5 ng (P less than 0.2, by Student's t test), respectively, on day of treatment and were 0.4 ng and 5.0 ng (P less than 0.005, by Student' t test) on day 5 after treatment. Pregnancy rates were 57% for treated and 47% for control cows (P = 0.5, by X2). Days from treatment to first-observed estrus, treatment to first service, and treatment to conception were significantly reduced in the treatment group compared with these criteria for the control group (P less than 0.05, 0.005, and 0.01 respectively). It was concluded that induction of luteolysis with PGF2 alpha in lactating dairy cattle with unobserved estrus and a palpable functional CL will be an effective addition to reproductive health programs.

Animals↗