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Biomedical subjects

J Carter

Publications and source records attributed to J Carter.

At least 217 records · Page 12Linked to original sources
PubMed1987

Functional analysis of a clonal expansion of Leu 11 positive NK active lymphoid cells.

A female patient with an unusual lymphoproliferative disease associated with marked neutropenia has been observed for 36 months. The expanded cell population consists of large lymphocytes, many of which contain large azurophilic granules with acid phosphatase activity. These cells were T3, T8, T11 and Leu 11 positive but lacked the M1, T10, IL-2 receptor and HLA.DR antigens. The majority of these cells (60-70%) were also Leu 7 (HNK-1) positive. Strong natural killer (NK) activity was found in both the Leu 7 positive and negative cell populations. This cytotoxic activity was inhibited by monoclonal antibodies known to inhibit NK activity but was unaffected by antibodies which block T cell and T/NK cell cytotoxicity. Further functional analysis indicated that these cells suppressed normal T cell responses to mitogens, MLC responses and PWM induced B cell immunoglobulin synthesis. No effect on bone marrow progenitor cell growth was demonstrated. Antibody dependent cellular cytotoxic (ADCC) activity was barely detectable despite the presence of the Leu 11 antigen. Southern blot DNA analysis demonstrated clonal rearrangement of the T cell receptor beta gene thereby confirming that this variant of T gamma lymphoproliferative disease was a neoplastic condition.

Adult↗
PubMed1987

Vacuum extraction and forceps delivery in a district hospital.

We compared 302 vacuum extractions and 205 forceps deliveries at Fairfield District Hospital, Sydney, over a period of 30 months. Age, parity, gestational age, length of labour and birth-weight were not significantly different between the 2 groups. Significantly less analgesia was required for mothers whose babies were delivered by vacuum extraction compared with mothers with forceps deliveries (p less than 0.01). Average blood loss was slightly higher during forceps delivery as compared with vacuum extraction and there was a significantly higher incidence of postpartum haemorrhage after forceps delivery (p less than 0.05). More babies were jaundiced after vacuum extraction and more required phototherapy, but the differences were slight and were not statistically significant. We conclude that vacuum extraction is a useful and safe alternative to forceps delivery in a district hospital setting.

Adolescent↗
PubMed1986

Proposed alignment of helical interruptions in the two subunits of the basement membrane (type IV) collagen.

We have isolated a cDNA clone for part of the alpha 2 type IV collagen (pCIV-2-176). Deoxynucleotide sequence analysis shows that this clone codes for 439 amino acids from the helical domain adjacent to the C-terminal globular domain of the alpha 2 (IV) chain. By aligning the deduced amino acid sequence of the alpha 2 (IV) chain with the published sequence for the alpha 1 (IV) chain, we find that all interruptions in the alpha 1 (IV) chain coincide with an interruption in the alpha 2 (IV) chain. Additional interruptions in the alpha 2 (IV) chain exist, however, three out of the four analysed only slightly disturb the collagen triple helix.

Amino Acid Sequence↗
PubMed1986

Lack of production of thromboxane A2 by the sheep heart following coronary occlusion.

Blood pressure, heart rate and ECG were monitored continuously and coronary venous blood samples assayed for thromboxane B2. Arterio-coronary venous lactic acid differences were estimated. In anaesthetized sheep, 60 sec occlusions of the left circumflex coronary artery caused hypotension with little change in heart rate. Five minute occlusions produced similar changes accompanied by cardiac arrhythmias and a larger fall in blood pressure. In conscious sheep heart rate rose and blood pressure was maintained. ECG and lactic acid changes indicated severe myocardial ischaemia but not change in thromboxane release was detected. The apparent lack of involvement of thromboxane may reflect a relative inability of sheep platelets to produce this substance or a failure to provide an adequate stimulus for synthesis.

Anesthesia↗
PubMed1986

Myocardial ischaemia following electrical stimulation of the left circumflex coronary artery in sheep: a role for thromboxane A2?

The electrical stimulation model of thrombus formation was tested on rabbit carotid artery and adapted to sheep left circumflex coronary artery (LCCA). LCCA blood flow, mean arterial pressure (MAP), heart rate (HR) and ECG were monitored continuously and arterial and coronary venous blood samples were taken for radioimmunoassay of thromboxane B2. Stimulation of the LCCA mimicked acute myocardial infarction; reduction in LCCA blood flow preceded a fall in MAP and appearance of ECG abnormalities. Thromboxane B2 levels rose by 126% 35 min after stimulation. These findings support the proposal by other authors that thromboxane plays an important role in the pathogenesis of acute myocardial infarction.

Anesthesia↗
PubMed1986

The effects of certain vasodilating prostaglandins on the coronary and hindlimb vascular beds of the conscious sheep.

Vasodilating prostaglandins were injected, in bolus doses, into the lower abdominal aorta or left circumflex coronary artery (LCCA) of conscious sheep. Local blood flow, mean arterial pressure (MAP), heart rate (HR) and ECG were monitored continuously. 6-Keto PGF1 alpha had no effect on either vascular bed in doses up to 100 micrograms. PGE2 was more potent than PGI2 in dilating hindlimb vasculature and PGE2 induced a more persistent hyperaemia whereas PGD2 elicited a biphasic response (constriction-dilation). PGE1, PGE2, PGD2 and PGI2 all produced dose-dependent vasodilation, the order of potency being PGD2 greater than PGI2 greater than PGE1 greater than or equal to PGE2. The effect of PGI2 was more transient and PGE1 and PGD2 caused small but consistent decreases in MAP and HR, respectively.

Animals↗
PubMed1986

The effects of vasoconstricting prostanoids on the coronary and hindlimb vascular beds of the conscious sheep.

Vasoconstricting prostaglandins were injected, in bolus doses, into the lower abdominal aorta on the left circumflex coronary artery (LCCA) of conscious sheep. Local blood flow, mean arterial pressure (MAP), heart rate (HR) and ECG were continuously monitored. Thromboxane B2 had no effect on either vascular bed in doses up to 100 micrograms. PGF2 alpha produced mild vasoconstriction in both vascular beds with no systemic response. The endoperoxide analogues, U-44069 and U-46619, produced complex responses in both vascular beds. Initial vasodilation was followed rapidly by prolonged vasoconstriction. In the coronary circulation, vasoconstriction was temporarily masked by a hyperaemic phase. The U-compounds also affected MAP, possibly as a result of pulmonary and systemic vasoconstriction.

Animals↗
PubMed1986

Buspirone in Parkinson's disease.

Buspirone, an anxiolytic unrelated to benzodiazepines that may act at the presynaptic dopamine receptor, was given to 11 patients with Parkinson's disease in an open label study. Seven patients completed the initial 10 week study achieving doses of 50-70 mg/day without any significant change in their clinical status. Six patients continued for an additional 3-11 weeks with increases in dose to 65-100 mg/day. Two of the three most severely affected patients had mild worsening of parkinsonian symptoms. Buspirone is ineffective in the treatment of Parkinson's disease, but at anxiolytic doses (less than 40 mg/day) does not adversely affect parkinsonian disability.

Adult↗
PubMed1986

Molecular defects in 2 examples of severe Hb H disease.

Severe Hb H disease presented in unexpected ways in 2 families of Greek origin. In 1, Hb H disease led to neonatal death. The underlying molecular defect was double-heterozygosity for the --Med/ alpha thalassaemia haplotype and a nondeletional alpha thalassaemia defect (alpha alpha T'Karditsa'/). The 2nd family requested antenatal diagnosis. The husband had mild nondeletional alpha thalassaemia. Initial investigations in the wife demonstrated unexpected gene mapping patterns. These have recently been shown to result from the (-alpha)Med 20.5/ haplotype.

Chromosome Mapping↗
PubMed1986

Cat scratch disease. Identification of bacteria in seven cases of lymphadenitis.

A retrospective study of lymph node biopsy specimens from nine patients with the clinical findings and histologic features of cat scratch disease was undertaken to determine whether the recent report by Wear et al. that pleomorphic bacteria are present in the lymph nodes of cat scratch disease could be confirmed. In seven of our nine cases, pleomorphic bacteria were demonstrated with the Warthin-Starry (WS) silver stain. These were gram-negative with the Brown-Hopps tissue Gram stain and were almost at the limit of microscopic resolution. Lymph node specimens from 13 additional patients with nonspecific lymphadenitis who had neither clinical nor histologic findings of cat scratch disease were studied similarly; in none of these were bacteria demonstrated with the WS silver stain. After examining the distribution of the organisms and the related morphologic features in cat scratch disease, we conclude that demonstration of pleomorphic, gram-negative, WS-positive bacteria in the appropriate clinical and histologic setting can firmly establish the diagnosis of cat scratch disease.

Adult↗
PubMed1986

Development and maintenance of bovine cytotoxic lymphocytes with recombinant human interleukin-2.

Long-term bovine lymphocyte cultures were initiated by stimulation with alloantigens and maintained in continuous culture using medium containing recombinant human interleukin-2 (rh IL-2). The development of specific and lectin-dependent killing was monitored following primary alloantigen challenge. Cytolytic activity was barely detectable after 7 days of culture, but gradually increased with peak activity occurring after 21 days of culture. A panel of monoclonal antibodies (MoAb) was used to determine whether a shift in the antigen phenotype of the cell population occurred during culture. The primary cell type that grew in culture was of the T-cell lineage with minimal or no expression of class II antigens. The activities of adenosine deaminase (ADA), purine nucleotide phosphorylase (PNP), adenosine kinase (AK), deoxyadenosine kinase (dAK), deoxycytidine kinase (dCK), 5'-nucleotidase (5'-N), AMP deaminase, hypoxanthine-guanine phosphoribosyl transferase (HGPRT or HPRT), and adenine phosphoribosyl transferase (APRT) were measured by microassay in resting peripheral blood lymphocytes (PBL) and in cells from long-term cultures. Large increases in the activities of PNP and HPRT with a decrease in the activity of ADA were observed. The data show that long-term cultures of lymphocytes can be readily generated, and that sequential changes in antigenic phenotype and function can be monitored and correlated with quantitative changes in enzyme activity.

Animals↗
PubMed1985

The cytotoxic and photodynamic inactivation of micro-organisms by Rose Bengal.

Rose Bengal was cytotoxic to the following bacteria at the concentrations given in parentheses (highest concentrations of dye in mol/l at which growth occurred on nutrient medium): Brochothrix thermosphacta and Deinococcus radiodurans (1 X 10(-6) or less); Streptococcus, Micrococcus, Staphylococcus, Bacillus, Arthrobacter and Kurthia spp. (1 X 10(-5)-1 X 10(-4], and Pseudomonas spp. and Enterobacteriaceae (5 X 10(-3)-1 X 10(-2) or greater). These organisms were killed rapidly when suspended in illuminated (170 microE/m2/s) solutions of Rose Bengal (1 X 10(-4) mol/l) providing oxygen was present. Singlet oxygen was identified as the lethal agent, because the rate of killing was increased by dissolving the dye in deuterium oxide while the organism were protected against photoinactivation by L-histidine or crocetin. Yeasts from chilled foods were killed in illuminated solutions of Rose Bengal but a light intensity of 315 microE/m2/s was needed for a death rate comparable with that of bacteria. The yeasts present in a range of chilled meat and dairy products failed to form colonies on Rose Bengal (5 X 10(-5) mol/l) media exposed continuously to modest illumination (55-80 microE/m2/s).

Bacteria↗
PubMed1985

Cardiac digital angiography: applications in ventriculography and coronary arteriography.

Clearly, computer-based digital subtraction offers several advantages over conventional approaches to contrast angiography. Using the newer method, in many situations contrast loads can be beneficially reduced, radiation exposure can be markedly diminished, and right ventricle evaluations can be simplified. In addition, storage of data on magnetic tape is less space consuming, and less costly, than storage on film. Over the 5- to 10-year life expectancy of a digitally equipped laboratory, these advantages probably justify the 30-50% increase in the initial monetary outlay for equipment in excess of that required for a conventionally equipped laboratory. However, the greatest promise of digital angiography is in the area of coronary arteriography. If three-dimensional reconstruction of coronary lesions and determination of regional flow can be effected, important advances in diagnosis and in prognostication theoretically might be expected, leading to more appropriate selection of therapy for individual patients than now can be achieved. However, currently available information does not yet indicate the extent to which such potential advantages will be realized. Thus, it will be several years before we will know whether the exciting potential of digital angiography in this area can be reached.

Angiography↗
PubMed1985

Fetal stimulation of maternal immunoglobulin production in mice.

Within 12-24 h of parturition in mice, there was a dramatic increase in the number of immunoglobulin secreting cells in the paraaortic lymph nodes (PALN) draining the pregnant uterus. Compared with stimulation with lipopolysaccharide the ratio of IgG:IgM forming cells was very high in PALN draining a pregnant uterus. The response was eliminated when fetectomy (ablating the embryo but leaving the placenta intact) was carried out on the 12th day of pregnancy. With unilateral fetectomy the uterine horn with intact fetal/placental units can be used as a positive control since lymphoid drainage is laterally confined. Neither healthy (gross and histological criteria) nor partly necrotic placentae stimulated Ig secreting cells in the PALN. The placentae of bilaterally fetectomized females were delivered apparently normally and at about the same time as normal (control) fetuses. Injection of prostaglandin E-2 or F-2 alpha into the tail base led to the appearance of Ig-forming cells in the PALN of normal (virgin) female mice. Indomethacin fed to the pregnant female greatly reduced the numbers of these cells in the PALN. We conclude that the observed local stimulation of maternal Ig production by the fetus may be involved in the transplacental transfer of Ig from mother to fetus.

Animals↗
PubMed1984

Perinatal bacterial infection after prolonged rupture of amniotic membranes: an analysis of risk and management.

Chi-square and logistic stepwise multiple regression analysis of perinatal determinants of infant bacterial infection following prolonged rupture of amniotic membranes for 24 hours or more prior to delivery was applied in 33 infected infants and 66 matched control infants from the NINCDS Collaborative Project. In order of statistical significance, the most important variables were placental inflammation (P = 0.002), gestational age less than 34 weeks (P = 0.008), gestational age 34 to 37 weeks (P = 0.013), male sex (P = 0.015), Apgar score less than 6 at 5 minutes (P = 0.023), and clinical amnionitis (maternal fever, fetal tachycardia, or amniotic or gastric fluid leukocytes or bacteria) (P = 0.044). Duration of labor during PROM, race, and maternal age and parity were insignificant. Using these predictive variables, identification of infected infants for either microbial surveillance (superficial and systemic cultures) or microbial surveillance and anticipatory antibiotic therapy (discontinued after 3 days of negative cultures) was highly significant (P = 0.0001). Incorporating these variables and derived coefficients from multivariate analysis, a mathematical model was used for evaluation and prediction of perinatal bacterial infection with a sensitivity of 82% and specificity of 70%. Analysis of 46 infants prior to and 310 infants after implementation of this process at Harbor-UCLA Medical Center indicated significant improvement in the appropriate management of these infants at risk (from 59% to 87% of the population, P less than 0.05). Inappropriate antibiotic therapy decreased from 35% to 10% (P less than 0.05). In the absence of a shift in the median days of hospitalization of non-PROM infants, determination of the grand median days of PROM infant hospital stay showed a decrease (P less than 0.01) after initiation of this evaluation and management scheme.

Amnion↗