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Biomedical subjects

D A Baker

Publications and source records attributed to D A Baker.

At least 127 records · Page 7Linked to original sources
PubMed1981

Synthesis of the t [beta-D-Gal-(1 goes to 3)-alpha-D-GalNAc]-antigenic determinant in a form useful for the preparation of an effective artificial antigen and the corresponding immunoadsorbent.

The T antigenic determinant was synthesized in the form 8-methoxycarbonyloctyl 2-acetamido-2-deoxy-3-O-(beta-D-galactopyranosyl)-alpha-D-galactopyranoside (6) (beta-D-Gal-(1 goes to 3)-alpha-D-GalNAcO(CH2)8CO2Me). This T-hapten was used to prepare a T-BSA artificial antigen (7) and an immunoadsorbent (8), which were shown to possess the expected immunological properties. Nuclear Overhauser enhancements of the signals for anti-periplanar H-2' and the syn-axial H-3' of the beta-D-galactopyranosyl group were observed on saturation of H-1'. The signal for H-3 of the 2-acetamido-2-deoxy-alpha-D-galactopyranoside residue was also enhanced.

Antigen-Antibody Complex↗
PubMed1981

Artificial antigens. Antibody preparations for the localization of Lewis determinants in tissues.

High-titer antisera specific for the Lewis-a, -b, and -d determinants were obtained by the immunization of rabbits with artificial antigens prepared by coupling chemically synthesized haptens to bovine serum albumin. The use of the appropriate synthetic immunoadsorbents allowed the isolation of the desired antibodies from the sera and the elimination of cross-reactive antibody populations. The resulting refined antibodies proved highly effective for the localization by immunofluorescence staining of Lewis antigens in epithelial cells of gastric and duodenal tissue of H patients. Furthermore, the immunohistochemical procedures could be performed in conventionally prepared paraffin tissue sections. In erythrocyte Lewis-a and -b individuals, the strongest staining reactions were with the appropriate reagent. Lewis-a individuals were Lewis-d negative. Tissue from Lewis-a--b--secretors showed strong positivity in the epithelial cells of the stomach only with the Lewis-d reagent while none of the reagents showed strong reactions with the tissue from the one nonsecretor Lewis-a--b--patient. The significance of these results to the biogenesis of the Lewis antigens is discussed.

Animals↗
PubMed1980

Suppression by progesterone of nonspecific in vitro lymphocyte stimulation in mice as a mechanism for the enhancement of herpes simplex virus type 2 vaginal infection.

The role of antibody, interferon, and cell-mediated immunity (CMI) were studied to determine the mechanisms for progesterone enhancement of vaginal herpes simplex virus type 2 (HSV 2) infection in mice. Three groups of mice were studied: nonpregnant control, pregnant, and nonpregnant progesterone-treated mice. Vaginal infection with HSV 2 did not elicit a neutralizing antibody or a systemic interferon response in any of the groups tested. Splenic lymphocytes from noninfected and infected mice were stimulated in vitro with a nonspecific T-cell mitogen concanavalin (Con A) to measure the proliferative phase of CMI in these groups of mice. No suppression of (3H) thymidine (3HTdR) uptake was found in the pregnant or nonpregnant, progesterone-treated animals as compared to nonpregnant control mice. When progesterone was added directly to the splenic lymphocytes and continuously present during Con A stimulation a statistically significant depression of 3HTdR incorporation was found. We concluded that progesterone depresses Con A stimulation of murine lymphocytes, but progesterone must be continuously present to do so.

Animals↗
PubMed1980

Maternal and neonatal infection with coxsackievirus.

Evidence is growing that relates maternal coxsackievirus infection to increased neonatal mortality and an increase of congenital anomalies. Four cases of fulminant perinatal coxsackievirus infections that were fatal to the newborns are presented. Coxsackievirus infections in pregnancy are usually either subclinical or produce minimal symptoms in the mother. The cases presented point out the potential severity of coxsackievirus infections in the neonatal period. Prevention of the disease and isolation of infected individuals are the mainstays of therapy.

Adolescent↗
PubMed1980

Alpha-fetoprotein concanavalin A-binding variants in the diagnosis of neural tube defects and other communicating fetal abnormalities.

We have extended our initial observations (Smith et al., 1979) on th use of determining the alpha-fetoprotein (AFP) concanavalin A-binding variant patterns in amniotic fluid for the detection of certain fetal malformations. We report here our complete series of amniotic fluids between 14 and 36 weeks of gestation from 52 normal pregnancies and 28 abnormal pregnancies including anencephaly, open spina bifida, Turner's syndrome, omphalocele, osteogenesis imperfecta congenita, meningomyelocele, meningocele, spinal cysts, spontaneous abortion and fetal death. The percentage of the total amniotic fluid AFP which was not reactive with concanavalin A was significantly lower in the presence of a communicating fetal abnormality (mean = 4.8%, P less than 0.001), one in which the fetal/amniotic fluid barrier is defective, than in the presence of a normal fetus (mean = 24.7%) (or of a noncommunicating fetal abnormality. We applied the concanavalin A-binding assay to two of the above amniotic fluids from pregnancies in progress and correctly classified the gestations as abnormal. Our results indicate that measurement of the percentage of concanavalin A-non-reactive amniotic fluid AFP is a valuable adjunct in the diagnosis of a communicating fetal abnormality, especially when the elevation of amniotic fluid AFP concentration is equivocal (between 2 and 5 S.D. above the mean), when gestational aging is uncertain or when the total amniotic fluid AFP concentration and ultrasonographic data are inconsistent.

Amniotic Fluid↗
PubMed1980

Solitary nonparasitic hepatic cyst causing obstructive jaundice.

Solitary nonparasitic hepatic cysts are rarely associated with jaundice and abnormalities of liver function have been attributed to hepatocellular disease in the absence of a separate obstructing lesion of the biliary tree. This case represents the first cholangiographic documentation of a solitary nonparasitic hepatic cyst compressing biliary radicles resulting in obstructive jaundice. The implication for treatment is discussed.

Aged↗
PubMed1979

Ultrasound detection of a carcinoid tumor.

The intraluminal component of symptomatic malignant carcinoid tumors of the small bowel is typically small relative to the extension in the mesentery, and barium examinations are occasionally normal. This case report illustrates the diagnostic value of abdominal ultrasonography in the detection of extraluminal component of a carcinoid tumor.

Carcinoid Tumor↗
PubMed1979

Colonic ileus. Indication for prompt decompression.

Eleven cases of colonic ileus were associated with a variety of clinical conditions. The dominant roentgenographic finding was severe cecal dilation. Its recognition and prompt management are required to prevent possible disastrous perforation.

Cecum↗
PubMed1979

Water-borne contamination of intrauterine pressure transducers.

Internal intrapartum fetal monitoring has been implicated as a source of maternal and fetal sepsis. We report water-borne contamination of a component of the intrauterine pressure transducer and suggest that this may be a potential source of nosocomial infection.

Alcaligenes↗
PubMed1979

The influence of hydration and bladder distension on the sonographic diagnosis of hydronephrosis.

Renal sonography is frequently employed to exclude obstructive uropathy in patients with uremia. Sonographic findings of moderate bilateral hydronephrosis were encountered in a dehydrated patient undergoing rehydration. Subsequent excretory urography and a follow-up renal sonogram were normal. To investigate the possibility that hydration and bladder distension in an otherwise normal and unobstructed collecting system could result in hydronephrosis detectable by ultrasound, 23 apparently normal volunteers underwent renal sonography in the hydrated and basal states. The filled urinary bladder in a patient undergoing hydration frequently results in the sonographic appearance of hydronephrosis.

Adult↗