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Biomedical subjects

S A Young

Publications and source records attributed to S A Young.

At least 37 records · Page 2Linked to original sources
PubMed1995

Intrauterine coxsackie virus, group B type 1, infection: viral cultivation from amniotic fluid in the third trimester.

We report a case that presents clear evidence of an intrauterine infection of twin fetuses with an enterovirus. The mother had signs and symptoms of chorioamniotitis at 34 weeks' gestation. Coxsackie virus, group B type 1 (CVB1), was cultured from amniotic fluid obtained by transabdominal amniocentesis when the membranes of both fetuses were still intact. Delivery occurred vaginally approximately 24 hours later, following spontaneous rupture of membranes. At birth, both twins showed signs of sepsis. Postpartum, CVB1 was recovered from the mother's cervix, and the newborns' cerebrospinal fluid, nasopharyngeal, and rectal swabs. The present significance of this case is discussed.

Adult↗
PubMed1995

Rice cationic peroxidase accumulates in xylem vessels during incompatible interactions with Xanthomonas oryzae pv oryzae.

A cationic peroxidase, PO-C1 (molecular mass 42 kD, isoelectric point 8.6), which is induced in incompatible interactions between the vascular pathogen Xanthomonas oryzae pv oryzae and rice (Oryza sativa L.), was purified. Amino acid sequences from chemically cleaved fragments of PO-C1 exhibited a high percentage of identity with deduced sequences of peroxidases from rice, barley, and wheat. Polyclonal antibodies were raised to an 11-amino acid oligopeptide (POC1a) that was derived from a domain where the sequence of the cationic peroxidase diverged from other known peroxidases. The anti-POC1a antibodies reacted only with a protein of the same mobility as PO-C1 in extracellular and guttation fluids from plants undergoing incompatible responses collected at 24 h after infection. In the compatible responses, the antibodies did not detect PO-C1 until 48 h after infection. Immunoelectron microscopy was used to demonstrate that PO-C1 accumulated within the apoplast of mesophyll cells and within the cell walls and vessel lumen of xylem elements of plants undergoing incompatible interactions.

Amino Acid Sequence↗
PubMed1995

Rape trauma syndrome in the military courts.

The military courts have developed a rich case law tradition in the area of rape trauma syndrome testimony. These cases are particularly important in the context of a military that is both increasingly female and increasingly sensitive to mixed gender relationships. This article reviews the military court's approach to rape trauma testimony over the past 15 years. The author notes that military courts have been accepting of this testimony within certain well defined limits. The author analyzes the approach to testimony at one military medical center and offers a testimony model for the forensic psychiatrist who testifies in a military setting.

Adult↗
PubMed1994

Molecular epidemiology of gastric colonization by Enterococcus faecalis in a surgical intensive care unit.

We applied restriction endonuclease analysis of genomic DNA using pulsed field gel electrophoresis (PFGE) to study gastric colonization with Enterococcus faecalis among patients hospitalized in the surgical intensive care unit (SICU). Isolates were obtained by culturing prospectively the gastric contents of 140 patients in the SICU. In addition, cultures of respiratory specimens were obtained daily and cultures of blood, normally sterile body fluids, wounds, and urine were obtained when indicated clinically. A total of 177 isolates were obtained from 45 patients. Concentrations of E. faecalis in gastric fluid ranged from 1 x 10(2) colony forming units (CFU)/ml to greater than 5 x 10(7) CFU/ml (mean 8.0 x 10(6) CFU/ml). Overall, 33 different DNA types were identified by PEGE. In examining strain variation among isolates obtained from multiple anatomic sites over time, we found that the same DNA type was recovered from gastric aspirates, sputum, and wounds in a given patient and that these strains were carried over time. In general, given individuals were colonized with their own unique DNA type; however, one DNA type (type C) was shared by 11 different patients, and seven DNA types were shared by two individuals each. These results demonstrate the potential importance of gastric colonization as a reservoir for nosocomial strains of E. faecalis in an SICU setting.

Colony Count, Microbial↗
PubMed1994

Occult congenital syphilis in macerated stillborn fetuses.

Five cases of macerated stillborn fetuses with congenital syphilis were studied. Despite severe maceration with visceral autolysis, spirochetes could be easily detected using Warthin-Starry stains. Clues that led to performing silver stains included the presence of an enlarged liver, spleen, chorioamnionitis, and nucleated red blood cells in villous capillaries. In a patient population where prenatal care is not always obtained, and maternal serologic tests results are not available at the time of delivery, these pathologic clues are very helpful in detecting congenital syphilis in macerated stillborn fetuses where the classic findings of syphilitic infection, including hydrops fetalis and plasma cell infiltrates, may be masked.

Adolescent↗
PubMed1994

Nitrogen dioxide and respiratory illness in children. Part III: Quality assurance in an epidemiologic study.

This report describes the quality assurance and quality control program developed for the previously reported epidemiologic study of nitrogen dioxide (NO2) and respiratory illness in children (Health Effects Institute Research Report 58, Parts I and II). The specific aims of the program were to make certain that data were sufficiently accurate, complete, verifiable, and retrievable. The quality assurance and quality control program consisted of: a written protocol, standard operating procedures, written records, a project management system, appropriate data processing, data verification, and data analysis planning, and was staffed by qualified and appropriately trained personnel. Within the activities of the overall program, two focused quality assurance studies were conducted. During the first of these focused studies, parents maintained a calendar-diary of their child's daily respiratory symptoms. Telephone interviews were conducted at intervals of two weeks, and parents used the calendars to report on symptom occurrence since the previous call. To assess the comparability of illness events based on symptom reports from the parents with usual clinical diagnostic methods, nurse practitioners examined children during illness, and office and clinic records of outpatient visits were reviewed. Using the parent reports, respiratory illnesses were defined as symptom episodes of at least two consecutive days; lower respiratory illnesses included at least one day of either wet cough or wheeze. Runny or stuffy nose was reported for 93% of illnesses; and wet cough for 33% and wheeze for 6% of illnesses. In comparison with the diagnoses made by a nurse practitioner, parent reports of wet cough or wheeze were sensitive (93.4%) for detecting lower respiratory illnesses, but nonspecific (with specificity of only 24.2%). The majority of the false-positive lower respiratory illnesses had the symptom of wet cough. The comparison of parent reports with outpatient records provided similar findings. These findings indicate that standardized reporting of respiratory illnesses can be achieved with regular telephone interviews, but the classification of specific illnesses from the observations of parents' information may differ from diagnoses made by clinicians. The second focused quality assurance study evaluated the measurement error associated with the parents' use of passive diffusion samplers for NO2. Midway through the study, technicians conducted home visits to assess compliance with stated procedures, and to make independent measurements of NO2. Based on criteria for placement and use of the samplers, conditions of noncompliance were observed on about 40% of visits.(ABSTRACT TRUNCATED AT 400 WORDS)

Data Collection↗
PubMed1994

Outbreak of Hantavirus pulmonary syndrome in the southwestern United States. Response of pathologists and other laboratorians.

During late spring and early summer of 1993, national and international media called worldwide attention to a cluster of deaths in the southwestern United States. These patients succumbed to a rapidly progressive severe respiratory distress syndrome. After notification of state and national health agencies in mid-May, a major effort was launched to determine the cause of this often fatal respiratory distress syndrome, to advise the public on safety measures, and to determine the method of spread of this "mystery illness." Within weeks of recognition of the early cases, the Centers for Disease Control and Prevention announced the probable agent, a Hantavirus. This report details the response of pathologists, medical technologists, and other laboratory scientists to this new viral epidemic, with emphasis on activities that occurred within New Mexico.

Adolescent↗
PubMed1993

Relationship between frequent episodes of peritonitis and altered immune status.

A 60-year-old Native American diabetic female patient had a history of nine episodes of peritonitis (both relapsing and persistent) during the year that she was treated with continuous ambulatory peritoneal dialysis (CAPD). At the start of CAPD the patient had an inverted CD4 to CD8 ratio that decreased from 0.97 to 0.50 in 1 year. This finding was due to a decrease in CD4+ cells and an increase in CD8+ cells that were also positive for CD57 (Leu-7) and HLA-DR (Ia) antigen, suggesting a state of activation. The serology indicated a cytomegalovirus immunoglobulin G titer of 1:2,048. The patient also had significantly increased natural killer cells. These alterations suggest the presence of a chronic viral infection that may have caused the patient to be immunosuppressed, thereby predisposing her to repeated episodes of peritonitis.

CD4-CD8 Ratio↗
PubMed1993

Comparability of parent reports of respiratory illnesses with clinical diagnoses in infants.

In a cohort study of respiratory illnesses from birth through age 18 months, the investigators assessed the occurrence of illness by telephone reports of respiratory symptoms. To assess the comparability of illness events based on symptom reports with usual clinical modalities, a nurse practitioner examined children during illnesses, and office and clinic records of outpatient visits were reviewed. Respiratory illnesses were defined as symptom episodes of at least 2 days; lower respiratory illnesses included at least 1 day of either wet cough or wheeze. This report is based on 10,771 illnesses in the 1,315 subjects enrolled. Runny or stuffy nose was reported for most (93%) illnesses, wet cough in 33%, and wheeze in 6%. In comparison with the diagnoses made by a nurse practitioner, parent report of wet cough or wheeze was sensitive (93.4%) for detecting lower respiratory illnesses, but nonspecific with specificity of only 24.2%. The majority of the false-positive lower respiratory illnesses had the symptom of wet cough. The comparison of parent reports with outpatient records provided similar findings. Standardized reporting of respiratory illnesses can be achieved with a telephone surveillance system but classification of specific illnesses from the surveillance information may differ from diagnoses made by clinicians.

Cohort Studies↗
PubMed1993

Nitrogen dioxide and respiratory illnesses in infants.

Nitrogen dioxide is an oxidant gas that contaminates outdoor air and indoor air in homes with unvented gas appliances. A prospective cohort study was carried out to test the hypothesis that residential exposure to NO2 increases incidence and severity of respiratory illnesses during the first 18 months of life. A cohort of 1,205 healthy infants from homes without smokers was enrolled. The daily occurrence of respiratory symptoms and illnesses was reported by the mothers every 2 wk. Illnesses with wheezing or wet cough were classified as lower respiratory tract. Indoor NO2 concentrations were serially measured with passive samplers place in the subjects' bedrooms. In stratified analyses, illness incidence rates did not consistently increase with exposure to NO2 or stove type. In multivariate analyses that adjusted for potential confounding factors, odds ratios were not significantly elevated for current or lagged NO2 exposures, or stove type. Illness duration, a measure of illness severity, was not associated with NO2 exposure. The findings can be extended to homes with gas stoves in regions of the United States where the outdoor air is not heavily polluted by NO2.

Air Pollutants↗
PubMed1993

Nitrogen dioxide and respiratory illness in children. Part I: Health outcomes.

We have carried out a prospective cohort study to test the hypothesis that exposure to nitrogen dioxide increases the incidence and severity of respiratory infections during the first 18 months of life. Between January 1988 and June 1990, 1,315 infants were enrolled into the study at birth and followed with prospective surveillance for the occurrence of respiratory infections and monitoring of nitrogen dioxide concentrations in their homes. The subjects were healthy infants from homes without smokers; they were selected with stratification by type of cooking stove at a ratio of four to one for gas and electric stoves. Illness experience was monitored by a daily diary of symptoms completed by the mother and a telephone interview conducted every two weeks. Illnesses with wheezing or wet cough were classified as involving the lower respiratory tract; all other respiratory illnesses were designated as involving the upper respiratory tract. Exposure to nitrogen dioxide was estimated by two-week average concentrations measured in the subjects' bedrooms with passive samplers. This analysis is limited to the 1,205 subjects completing at least one month of observation; of these, 823 completed the full protocol, contributing 82.8% of the total number of days during which the subjects were under observation. Incidence rates for all respiratory illnesses, all upper respiratory illness, all lower respiratory illnesses, and lower respiratory illness further divided into those with any wheezing, or wet cough without wheezing, were examined within strata of nitrogen dioxide exposure at the time of the illness, nitrogen dioxide exposure during the prior month, and type of cooking stove. Consistent trends of increasing illness incidence rates with increasing exposure to nitrogen dioxide were not evident for either the lagged or unlagged exposure variables. The effect of nitrogen dioxide exposure on illness occurrence during at-risk intervals of two weeks' duration was examined using the generalized estimating equation approach. In these multivariate analyses, none of the odds ratios was significantly elevated for unlagged nitrogen dioxide exposures, lagged nitrogen dioxide exposures, or stove type. Duration of illness was assessed in relation to the same exposure variables; illness duration and nitrogen dioxide exposure were not associated. We have found that indoor exposure to nitrogen dioxide is associated with neither the incidence nor the duration of respiratory illnesses. The study was designed to have sufficient power to detect effects of nitrogen dioxide exposure of magnitudes previously reported and in a range relevant to public health concern; the lack of association cannot be attributed to potential bias from misclassification of outcome or exposure.(ABSTRACT TRUNCATED AT 400 WORDS)

Air Pollutants↗
PubMed1992

Physical and functional characterization of the gene cluster encoding the polyketide phytotoxin coronatine in Pseudomonas syringae pv. glycinea.

Pseudomonas syringae pv. glycinea PG4180 produces the polyketide phytotoxin coronatine. The coronatine synthesis genes in PG4180 were previously shown to reside on a 90-kb plasmid designated p4180A. In the present study, clones containing a 34-kb region of p4180A were saturated with Tn5, and 71 unique mutations were recombined into p4180A by marker exchange. The effect of each mutation on coronatine synthesis was determined by analyzing the organic acids produced by the mutants by reverse-phase high-performance liquid chromatography. The organic acids of selected mutants were derivatized to their methyl esters and analyzed by gas chromatography and gas chromatography-mass spectrometry. Mutations in a 20.5-kb region of p4180A completely blocked the synthesis of coronafacic acid and coronatine. Mutations within a 4.4-kb region of p4180A prevented the formation of coronatine but allowed for production of coronafacic acid, coronafacoylvaline, coronafacoylisoleucine, and coronafacoylalloisoleucine. The phenotypes of selected mutants were further confirmed in feeding experiments in which coronafacic acid or coronamic acid was added to the culture media. The results of this study allow us to speculate on the likely sequence of steps in the later stages of coronatine biosynthesis.

Amino Acids↗
PubMed1992

Frontal lobe cerebral aneurysm rupture presenting as psychosis.

A 23 year old male with acute onset of blunted affect, looseness of associations and auditory hallucinations presented to a tertiary care hospital 10 days after development of symptoms. Before transfer, the patient received a diagnosis of schizophreniform disorder and treatment with haloperidol was started which resulted in moderate improvement. Examination led to detection of a ruptured cerebral aneurysm in the left frontal lobe. Evacuation of the haematoma and repair of the aneurysm resulted in nearly complete resolution of symptoms. The rare incidence of acute aneurysm rupture, presenting in the case described, demonstrates the importance of a complete neurological examination in the evaluation of acute mental status changes.

Adult↗
PubMed1992

Early viral brain invasion in iatrogenic human immunodeficiency virus infection.

We report a 68-year-old man who received an IV inoculation of WBCs for an indium radionuclide scan containing 600 to 700 tissue culture infectious doses of human immunodeficiency virus type 1 (HIV-1) from an HIV-1-infected individual. The recipient immediately received zidovudine, then was switched to dideoxyinosine and interferon-alpha, but died of hepatorenal syndrome and hepatic encephalopathy 15 days later. HIV-1 cultures were positive from the recipient's blood on day 14 but not days 0, 1, and 8. At autopsy, cultures of parietal lobe isolated HIV-1. HIV-1 nucleic acid was present in several brain areas, but not in several other organs, by two independent laboratories using the polymerase chain reaction. The brain showed mild perivascular cuffing and a mild lymphocytic meningitis, but there was no evidence of glial nodules, giant cells, or white matter abnormalities. HIV-1 pg41 viral antigen was seen by immunoperoxidase staining in rare infiltrating cells within perivascular and subpial spaces. Thus, HIV-1 was isolated from brain 15 days after mistaken HIV-1 inoculation and 1 day after virus was first recovered from blood.

Aged↗
PubMed1991

Conservation of Plasmid DNA Sequences in Coronatine-Producing Pathovars of Pseudomonas syringae.

In Pseudomonas syringae pv. tomato PT23.2, plasmid pPT23A (101 kb) is involved in synthesis of the phytotoxin coronatine (C. L. Bender, D. K. Malvick, and R. E. Mitchell, J. Bacteriol. 171:807-812, 1989). The physical characterization of mutations that abolished coronatine production indicated that at least 30 kb of pPT23A DNA are required for toxin synthesis. In the present study, P-labeled DNA fragments from the 30-kb region of pPT23A hybridized to plasmid DNAs from several coronatine-producing pathovars of P. syringae under conditions of high stringency. These experiments indicated that this region of pPT23A was strongly conserved in large plasmids (90 to 105 kb) that reside in P. syringae pv. atropurpurea, glycinea, and morsprunorum. The functional significance of the observed homology was demonstrated in marker-exchange experiments in which Tn5-inactivated sequences from the 30-kb region of pPT23A were used to mutate coronatine synthesis genes in the three heterologous pathovars. Physical characterization of the Tn5 insertions generated by marker exchange indicated that genes controlling coronatine synthesis in P. syringae pv. atropurpurea 1304, glycinea 4180, and morsprunorum 567 and 3714 were located on the large indigenous plasmids where homology was originally detected. Therefore, coronatine biosynthesis genes are strongly conserved in the plasmid DNAs of four producing pathovars, despite their disparate origins (California, Japan, New Zealand, Great Britain, and Italy).

Journal Article↗
PubMed1991

Diagnostic efficacy of in vitro methods vs. skin testing in patients with inhalant allergies.

The purpose of our study was to investigate the diagnostic efficacy of two selected methods of in vitro allergy testing. Specifically, the PRIST/modified RAST I125 isotope systems and the Quantizyme/modified EAST alkaline phosphatase method were compared. The time, expense, convenience, and diagnostic efficacy of the two procedures are discussed. Special attention is given to the practicality of each method for the practicing physician.

Alkaline Phosphatase↗
PubMed1991

The formation and application of an overseas mental health crisis intervention team, Part I: Formation.

The creation of an overseas mental health crisis intervention team is described. The authors discuss the unique aspects of an overseas low intensity conflict environment and the importance of immediate mental health responses to disaster situations in such theaters. Key elements in the formation of the team are the use of local resources, command endorsement, and an emphasis on education of commanders and team members. Examples are cited of other military response team deployments. The authors present their experience in Panama as a model for other providers in similar environments.

Crisis Intervention↗