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Biomedical subjects

A L Parker

Publications and source records attributed to A L Parker.

18 recordsLinked to original sources
PubMed2001

Accidents and injuries among U.S. Navy crewmembers during extended submarine patrols, 1997 to 1999.

Accidents and injuries, the most common cause of morbidity in military populations, result in a significant number of work days lost each year and account for 75% of all active duty deaths. Rates of accidents and injuries during U.S. Navy submarine deployments have not been evaluated previously. A database designed to monitor the health of submarine crew-members was used to examine the rates and causes of accidents among deployed crewmembers aboard 196 submarine patrols between 1997 and mid 1999. The most common category of injuries was open wounds, followed by sprains and strains, contusions, superficial injuries, burns, and others. Rates of accidents and injuries decreased with increasing age and duration of military service. Among submariners working in supply departments, the rates were more than two times those of crewmembers working in other departments. Based on these data, among a submarine crew of 100 men at sea for 100 days, approximately four to five accidents or injuries might be expected and would result in an average of about 2 days of light or no duty per injury. Rates of accidents and injuries were very low; however, focused safety training could reduce rates among younger and less experienced crewmembers as well as among those working in particular areas of the submarine.

Absenteeism↗
PubMed1997

Effect of dietary vitamin E supplementation on the integrity of skeletal muscle in exercised horses.

The effect of vitamin E intake on indicators of muscle integrity was studied in exercised horses. Nineteen horses were blocked by sex and then assigned to one of three diets: no supplemental vitamin E (BASAL), BASAL plus 80 IU of supplemental vitamin E/kg DM (80), or BASAL plus 300 IU of supplemental vitamin E/kg DM (300). The BASAL diet contained less than 44 IU of vitamin E/kg DM, but it was adequate in all other nutrients. During the 90-d treatment period, horses were exercised 5 d/wk; in addition, serum and middle gluteal muscle alpha-tocopherol concentrations were measured at 0, 30, and 90 d. All horses performed a repeated submaximal exercise test (RSET) at the end of the 90-d period. The following were measured before and after the RSET: alpha-tocopherol, thiobarbituric acid reactive substances (TBARS), conjugated diene (CD) concentrations of the middle gluteal muscle, and serum creatine kinase (CK) and aspartate aminotransferase (AST) activities. Serum alpha-tocopherol concentrations of horses receiving the BASAL and 80 diets decreased (P < .05 and P < .06, respectively) during the 90-d treatment period but did not change in horses receiving the 300 diet. Serum and muscle alpha-tocopherol concentrations were higher (P < .05) at 30 and 90 d in horses receiving the 300 diet than in horses receiving the BASAL and 80 diets. Serum CK and AST activities increased (P < .05) following RSET but were not affected by dietary vitamin E level. Muscle alpha-tocopherol level did not affect muscle CD or TBARS.

Animals↗
PubMed1996

Mechanism of ATP-induced leukocyte adherence to cultured pulmonary artery endothelial cells.

Previously we have shown that ATP enhances the adherence of HL-60 cells and human neutrophils to bovine pulmonary artery endothelial cells. The current investigations extend earlier findings by showing that ATP and UTP dose-dependently stimulate human neutrophil adherence to human pulmonary artery endothelial cells. We have also explore the mechanisms of ATP- and UTP-stimulated adherence. We have found that fucose, a component of selectin receptors, inhibits ATP-stimulated HL-60 cell-bovine pulmonary artery endothelial cell adhesion. Additionally, pretreatment of HL-60 cells with neuraminidase abolishes ATP enhancement. However, fucose does not affect ATP- or thrombin-induced adhesion of freshly isolated human neutrophils to human endothelial cells. Antibodies to human P-selection intercellular adhesion molecule (ICAM)-1, and the beta-subunit of CD11/CD18 do not alter ATP-induced adherence of HL-60 cells to bovine endothelial cells. Similarly, antibodies to human P-selectin and ICAM-1 do not inhibit human neutrophil-human pulmonary artery endothelial cell adhesion. The platelet-activating factor receptor antagonists, WEB-2086 and L-659,989, are effective in attenuating ATP- and UTP-stimulated adherence. Preincubation of neutrophils or human pulmonary artery endothelial cells with ATP or UTP also enhances adherence, an effect that is blocked by L-659,989. Thus platelet activating factor, associated with both neutrophils and endothelial cells, mediates ATP- and UTP-induced neutrophil adherence. ATP, released during vascular injury, may exacerbate neutrophil-endothelial cell interaction and thereby contribute to neutrophil-induced injury.

Adenosine Triphosphate↗
PubMed1993

The effect of edge orientation and movement direction on the apparent misalignment of collinear bars.

Four experiments on apparent misalignment of oblique collinear bars are reported. The data from the first three experiments showed that the misalignment was slight but significant when no direction other than that of the bars themselves was delineated and about double when the vertical was delineated by movements of the adjustable bar. When the vertical was delineated by both these movements and the ends of the bars (or by vertical parallel lines), the misalignment was more than six times greater. Conversely, it was reduced when the bar ends delineated the vertical and bar movements delineated the direction at right angles to the bars. The data from a fourth experiment showed that the inner pair of edges were closely involved in apparent misalignment and that the outer ends were not. The relationship between the misalignment effect with bars and the Poggendorff figure (oblique lines separated by parallels), the delineation of direction by edges and movement, and the implications of these data for an explanation are discussed.

Adult↗
PubMed1992

The Poggendorff illusion and apparent interparallel extents.

An explanation of the Poggendorff misalignment effect in terms of apparent contraction of interparallel extent resulting from the Müller-Lyer illusion was tested in three experiments. Three of the eight stimulus figures had oblique transversals outside the parallels in the usual way, three had them inside, and two were controls consisting of the transversals only. Müller-Lyer forms were differently delineated between the parallels for the inside-transversal and outside-transversal figures, and were not delineated in the control figures. In the first experiment apparent misalignment occurred in four of the six parallel-line figures and in neither of the controls. In the second experiment oblique extent between the parallels was underestimated in six of the eight figures and right-angle extent was overestimated in all of them. The results of the third experiment showed that right-angle (horizontal) extent between the parallels without transversals is estimated without significant error. The data from the three experiments do not support the interparallel-extent explanation of apparent misalignment. Instead, the results are interpreted in terms of independent perceptual compromises, one involving alignment of the transversals and the other the distance between them.

Adult↗
PubMed1992

Pregnancy-related mortality in New Jersey, 1975 to 1989.

OBJECTIVES: National data are thought to underestimate pregnancy-related mortality in the United States. A multisource surveillance system for pregnancy-associated deaths in New Jersey offers an opportunity to identify the magnitude of and the trends in pregnancy-related mortality at the state level. METHODS: Data from all reported pregnancy-related deaths in the state from 1975 to 1989 were studied, and pregnancy mortality ratios were calculated. RESULTS: The New Jersey pregnancy mortality ratio decreased from the late 1970s to the early 1980s but began to rise in the late 1980s. The pregnancy mortality ratio for non-Whites was 3.6 times that for Whites for the 15-year period. The causes of pregnancy-related deaths changed over the 15-year period, with direct obstetrical causes playing a decreasing role. AIDS has become the major cause of pregnancy-related mortality in New Jersey. Finally, approximately 44% of the pregnancy-related deaths were considered to be preventable by the physician or patient or both. CONCLUSIONS: New efforts must be made to combat the recent rise in pregnancy-related deaths, with special attention to preventing deaths among non-White women.

Adolescent↗
PubMed1989

Pregnancy-associated deaths due to AIDS in the United States.

From 1981 to 1988, eighty percent of all women with the acquired immunodeficiency syndrome (AIDS) reported to the Centers for Disease Control were of reproductive age. Six pregnancy-associated deaths due to AIDS in this country have been reported in the medical literature. We identified 20 unpublished cases of women who died of AIDS during or within one year after termination of pregnancy. Analysis showed that these women were mostly black or Hispanic, half were intravenous drug abusers, and most died of Pneumocystis carinii pneumonia. Each pregnancy had an obstetric complication, primarily preterm delivery. The interval between diagnosis of AIDS and the death of these women ranged from one day to 15 months, with a mean interval of 113 days. Multiple reporting sources increased case detection and should be used for future investigations. Prospective case-control studies are needed to determine any further relationship between pregnancy complications and AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Pectus excavatum defect on liver-spleen scintigraphy.

A 58-year-old man with a pectus excavatum demonstrated a photon-deficient defect within the left lobe of the liver on liver-spleen scintigraphy using Tc-99m SCOL. Computed tomography of the liver clearly revealed the abnormal defect seen on the liver-spleen scan to be due to the pectus excavatum. This case confirms the impression that these skeletal aberrations may cause false-positive hepatic defects.

Funnel Chest↗
PubMed1986

Gastrointestinal dissemination of coccidioidomycosis.

An unusual case of extensive gastrointestinal involvement by the fungus Coccidioides immitis is reported in a 21-yr-old man. This unique case demonstrates the occurrence of this fungus within chylous ascites, the mesentery, and invasion of the entire length of the small bowel. Histological and cultural documentation for gastrointestinal tract involvement by C. immitis other than for the rare occurrence of peritonitis has not been previously reported. The significance of the disseminated gastrointestinal coccidioidomycosis in the setting of chylous ascites and extensive abdominal lymphatic involvement is discussed with respect to its pathogenesis and treatment.

Adult↗
PubMed1985

Combined common bile duct and gastric outlet obstruction demonstrated during hepatobiliary scintigraphy.

A 64-year-old man presented with jaundice. Hepatobiliary imaging using 99mTc-DISIDA revealed complete hepatobiliary tract obstruction with a photopenic area corresponding to a dilated gallbladder and a large photopenic region corresponding to a distended stomach as a result of gastric outlet obstruction. At surgery, carcinoma of the head of the pancreas was found to be the cause of the combined common bile duct and gastric outlet obstruction.

Cholestasis↗
PubMed1984

Scintigraphic and radiographic findings in Caroli's disease.

In recent years, noninvasive evaluation of Caroli's disease has been demonstrated by computed tomography, ultrasonography, and nuclear scintigraphy. Confirmation of Caroli's disease requires invasive procedures such as percutaneous transhepatic cholangiography or endoscopic retrograde cholangiography. All of the techniques give valuable information making it easier to diagnose Caroli's disease and to determine its extent. In addition, associated abnormalities in organs outside of the biliary system may be revealed. Two cases are presented to illustrate the radiographic and scintigraphic findings of Caroli's disease.

Adult↗