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Biomedical subjects

D L Watson

Publications and source records attributed to D L Watson.

At least 91 records · Page 5Linked to original sources
PubMed1984

Pregnancy outcome in 303 cases with severe preeclampsia.

The purpose of the present clinical investigation was to determine the influence of aggressive management, associated medical/obstetric complications, race, and gestational age on fetal, neonatal, and maternal risks associated with severe preeclampsia. Three hundred and three consecutive pregnancies complicated by severe preeclampsia were studied. All patients were delivered within 48 hours after admission to the perinatal center. In 91 patients the disease was superimposed on chronic hypertension. There was a significant difference between patients with and those without prior chronic hypertension regarding perinatal mortality (32 versus 7.7%), incidence of abruptio placentae (10 versus 4%), and frequency of small-for-gestational-age infants (33 versus 14%). Fifty-one patients (17%) had thrombocytopenia, 26 (8.5%) had hemolysis, elevated liver enzymes and low platelet count syndrome, and 22 (7.3%) had disseminated intravascular coagulopathy. There was significant difference between white and black patients regarding the frequency of thrombocytopenia (28 versus 13%), hemolysis, elevated liver enzymes, and low platelet count syndrome (19.7 versus 5.3%), and coagulopathy (13 versus 1.4%). However, most of this apparent racial difference resulted from higher incidence of abnormal hematologic findings among patients who had conservative management by private physicians before transfer. Perinatal survival was zero when severe preeclampsia developed at or before 28 weeks, whereas it was 100% when disease developed after 36 weeks' gestation. The above factors should be considered in counselling patients with severe preeclampsia.

Abruptio Placentae↗
PubMed1984

Fetal supraventricular tachycardia: in utero therapy with digoxin and quinidine.

Digoxin has been successfully used to treat fetal supraventricular tachycardia. When therapy with digoxin fails, alternative therapies have met with equivocal success. In this report, successful fetal therapy with maternally administered digoxin and quinidine is presented in three consecutive patients with fetal supraventricular tachycardia. The arrhythmia was eliminated in each instance. Fetal ascites, present in two fetuses, was completely reversed. Intrapartum fetal distress was not observed. The rationale of this therapy and a review of pertinent literature are also presented.

Administration, Oral↗
PubMed1984

Selective transport of serum-derived IgA into mucosal secretions.

The relative contribution of serum-derived and locally produced IgA has been estimated in sheep mammary secretion at various stages of lactation by comparing the transport of radiolabeled IgA and IgG2 from serum to secretions. During early and mid-lactation, but not during involution, serum IgA was selectively transported to mammary secretion on a large scale; in comparison, there was no transport of serum IgA into intestinal secretion. Estimates of local production indicated that the bulk of the IgA in mammary involution secretion and intestinal secretion was locally produced, whereas there was no evidence for local production of IgA in early or mid-lactation secretion. Our studies reveal an inverse relationship between the extent of local production of IgA by plasma cells underlying secretory epithelia and the selective transport of IgA from serum. This finding suggests that selective transport of serum IgA occurs at a number of mucosal sites, but is dependent on secretory component availability, because where local production is predominant, there are fewer secretory component molecules available for serum IgA transport. For this reason, bile transport of IgA does not represent a unique mechanism for the removal of IgA from serum.

Animals↗
PubMed1984

Effect of magnesium sulfate on electroencephalographic findings in preeclampsia-eclampsia.

Electroencephalograms (EEGs) were recorded in 36 eclamptic, 14 preeclamptic, and 13 normotensive control patients. In the eclamptic group, EEGs were recorded while patients were receiving intravenous magnesium sulfate (MgSO4) with serum magnesium (Mg) levels of 4.5 to 11 mg/dL, and recorded again after MgSO4 was discontinued (serum Mg levels 1.8 to 2.5 mg/dL). In preeclamptic patients, EEGs were recorded before starting MgSO4, during administration of the loading dose (serum Mg levels 6 to 10 mg/dL), and eight hours through the maintenance dose (serum Mg levels 3.6 to 6.2 mg/dL). Twenty-seven (75%) eclamptic patients had abnormal EEGs, four patients showed paroxysmal spike activity, and the others showed focal or diffuse slowing (delta waves). Seven (50%) preeclamptic women had abnormal EEGs (all had generalized slowing). In preeclamptic-eclamptic patients who had serial EEG recordings, the gross EEG findings obtained during MgSO4 infusion and in the absence of MgSO4 were similar. In addition, the abnormal EEG findings were frequent despite the serum Mg levels considered therapeutic in the clinical management of these patients. Two eclamptic patients had seizure activity at serum Mg levels of 9.6 and 11 mg/dL. These findings suggested that abnormal EEGs are frequent in preeclamptic-eclamptic patients. Abnormal EEG findings in such patients are not altered by serum Mg levels achieved in the clinical management of these patients.

Adolescent↗
PubMed1983

Properties of neutrophils recruited into inflammatory foci with homologous or heterologous antigen in immunized ewes.

Studies were undertaken to determine functional properties of neutrophils attracted into involuted mammary glands of Staphylococcus aureus--immunized ewes by soluble antigens prepared from S. aureus (homologous antigen) or from Bacillus cereus (heterologous antigen). The ewes were immunized with an S. aureus vaccine known to stimulate synthesis of cytophilic IgG2 antibody, and the inflammatory responses were elicited 4-8 weeks later by infusing homologous antigen into one gland and heterologous antigen into the other. Inflammatory cells were collected at 2, 4, and 8 h postinfusion. The magnitude of the cellular responses was similar in both glands with high proportions of viable neutrophils. There were no significant differences between neutrophil populations from each gland for proportions of cells bearing cytophilic immunoglobulin, although the proportions of cytophilic immunoglobulin-positive cells from both glands were lower in 2-h exudates than in 4-h or 8-h exudates. In invitro phagocytosis assays using 3H-labeled S. aureus and B. cereus no differences could be detected between the two populations of neutrophils in terms of phagocytic efficacy using a range of bacteria-neutrophil ratios and various opsonizing treatments.

Animals↗
PubMed1983

Late postpartum eclampsia: an update.

Eclampsia occurring more than 48 hours postpartum has been observed in an unusual number of patients. From August 1977 to November 1982 at E. H. Crump Women's Hospital and Perinatal Center (Memphis), there were 132 documented cases of eclampsia, of which 36 (27%) occurred postpartum. Seventeen (47%) of these occurred more than 48 hours postpartum. Preeclampsia was diagnosed before the onset of convulsions in 12 patients, all of whom received intravenous magnesium sulfate postpartum. The mean duration of postdelivery magnesium sulfate therapy was 32 hours (range 24 to 72 hours). Headaches and visual disturbances were reported by all 17 patients before onset of convulsions. Physical and laboratory findings immediately after the convulsions were consistent with eclampsia. Treatment consisted primarily of intravenous magnesium sulfate. Neurologic consultation was obtained to rule out a neurologic disorder, and metabolic studies were also done. Electroencephalograms were done on 15 patients; eight of them showed patterns consistent with encephalopathy.

Blood Pressure↗
PubMed1983

An immunopathologic study of the bovine prepuce.

The prepuces of 83 bulls with macroscopically normal reproductive tracts were obtained at slaughter and microbiological, immunological, and histologic studies were done and the findings were correlated. Some bulls had been vaccinated on several occasions against Campylobacter fetus. Mean concentrations of intrapreputial immunoglobulins (Ig) in 27 bulls were IgG1 - 1.8 +/- 5.2; IgA - 0.16 +/- 0.15; and IgM - 0.24 +/- 0.24 mg/ml. High concentrations of IgG2 in some bulls precluded precise estimation but mean concentration was in excess of 11.0 mg/ml (range 0 to 20+ mg/ml). Differences between these concentrations were significant (P less than 0.005). Mean prevalences of class specific, immunoperoxidase-labeled plasma cells in the preputial dermis of 35 bulls were IgG - 39.0 +/- 9.3; IgA - 16.6 +/- 6.6; and IgM - 2.2 +/- 1.8 labeled cells/100 nuclei (P less than 0.001). The prevalence of IgG labeled cells in the preputial dermis was, however, negatively correlated with the concentration of intrapreputial IgG (IgG1 + IgG2) (r = -0.4; P less than 0.05). Except for an apparently lower intrapreputial Ig concentration in Trichomonas foetus-infected bulls than in negative ones, there were no significant correlations between intrapreputial immunoglobulin concentration, histologic findings, and age, infection, or vaccination status of the bulls.

Animals↗
PubMed1983

Novel immunofluorescent technique for identification of ovine immunoglobulins and other potential opsonins binding to live Staphylococcus aureus.

A qualitative in vitro technique has been developed for identification of potential opsonins (immunoglobulins G1, G2, A, M; the third component of ovine complement C3, and fibronectin) of sheep origin, binding to cell walls of viable Staphylococcus aureus. The technique uses monospecific antisera to these ovine proteins. The antisera are conjugated to FITC-protein A such that the protein A-binding sites in the Fc region of the immunoglobulin molecules are occupied with FITC-protein A complexes and are prevented, therefore, from binding to protein A in the staphylococcal cell wall. The technique is highly specific and sensitive, and once conjugated monospecific antisera are prepared, many tests can be done in a short time. Staphylococcus aureus incubated in samples of milk whey showed variable binding of immunoglobulins G1, G2, and M; immunoglobulin A was bound from only one sample of milk whey, and the third component of ovine complement C3- and fibronectin binding were not detected. Most samples of blood serum and colostral whey produced binding of immunoglobulins G1, G2, A, and M, and the third component of ovine complement C3 to the Staphylococcus aureus cell surface; fibronectin binding was found in serum but not in colostral whey. Washings from involuted mammary glands invariably produced binding of all immunoglobulins but not of the third component of ovine complement C3 or fibronectin.

Animals↗
PubMed1983

Maternal-fetal correlations in patients with severe preeclampsia/eclampsia.

A prospective pair-controlled study of maternal, cord blood, and neonatal hematologic findings was done in 50 severely preeclamptic/eclamptic and 50 well-matched normotensive pregnancies. There were no neonatal complications in mature infants. Neonatal complications were similar in premature infants of both study and control group; however, neonatal deaths were higher in the study group. In the study group, there was a poor correlation between maternal and cord blood hematocrit (r = .07), platelet count (r = .11), and fibrinogen (r = .05). In addition, there was no correlation (r = .06) between maternal and cord blood thrombocytopenia. Within each subgroup, abnormal neonatal hematologic findings were usually associated with fetal growth retardation, perinatal asphyxia, acidosis, sepsis, or intracranial hemorrhage. The present findings suggest that abnormal hematologic findings described in neonates of severely preeclamptic/eclamptic pregnancies are the result of associated neonatal complications, rather than a direct consequence of preeclampsia.

Adolescent↗
PubMed1982

Cellular basis for differences in humoral immune responses of sheep immunized with living or killed Staphylococcus aureus vaccines.

An immunohistological study was made of immunoglobulin-containing cells and antibody-containing cells in abscesses/granulomas which formed at the injection site, draining popliteal nodes and contralateral popliteal nodes of sheep given either a living Staphylococcus aureus vaccine (Group L), a killed S. aureus vaccine with Freund's complete adjuvant (FCA) (Group K) or FCA alone (Group C). The injections were made subcutaneously in the hind legs and second injections were given 4 weeks later in the same site. Very large numbers of IgM-containing cells were found in granulomas of Groups K and C at 1 week post-injection (PI) but by 2 weeks PI only small numbers were recorded. Following booster immunization, the numbers of IgM-containing cells were greater in abscesses from sheep in Group L than from granulomas from sheep in Group K. Levels for Group C remained low after 1 week PI. There was evidence that the very early IgM-containing cell response in Group K was largely unrelated to specific anti-staphylococcal antibody synthesis. The IgG2-containing cell response was significantly greater than the IgG1-containing cell response in abscesses and nodes in Group L. In contrast, for animals in Groups K and C the IgG1-containing cell response predominated over the IgG2-containing cell response in granulomas and draining nodes. There were generally greater numbers of cells containing anti-staphylococcal antibody in abscesses/granulomas and nodes in Group L than in Group K.

Adjuvants, Immunologic↗
PubMed1982

The influence of site of antigen deposition on the local immune response in the mammary gland of the ewe.

Experiments were carried out to compare the local antibody responses in mammary glands of ewes immunized by infusion of antigen (killed Brucella abortus) into the lactiferous sinuses (trans-epithelial presentation of antigen) or injection into the mammary tissue near the supramammary lymph node (interstitial presentation of antigen). Although both methods of antigen presentation resulted in similar antibody levels in blood, infusion of antigen into the lactiferous sinus resulted in significantly higher levels of agglutinating antibody in milk whey than did injection of antigen. When within-animal comparisons were made, infusion of antigen was also significantly superior to injection of antigen in terms of levels of non-agglutinating antibody in milk as determined by Coomb's antiglobulin assays. Evidence from immunoglobulin estimations in milk whey suggested that any elevation in concentrations of immunoglobulins (including IgA) in milk from ewes, which had received injections of antigen into mammary tissue, was associated with chronic inflammatory damage to these glands.

Animals↗
PubMed1982

The role of humoral and cellular mediators in enhanced mammary inflammatory reactions to staphylococcal infection in systemically immunized ewes.

Prior systemic immunization with live Staphylococcus aureus vaccine enhances the early recruitment of neutrophils into nonlactating mammary glands infected with staphylococci. The study investigates the role of humoral and cellular mediators in this phenomenon. Intramammary infusion of bacteria suspended in immune sheep serum did not enhance the inflammatory response to infection in nonimmunized ewes despite the presence of complement in the infused serum. Infusion of complement activated by incubation with zymosan evoked a massive neutrophil influx into mammary secretions by 4 hr after infusion. Hemolytic complement activity was not detected in mammary secretions of immunized or nonimmunized ewes. These findings indicate that, despite the inflammatory effect of complement activation, humoral immune factors did not promote neutrophil migration into infected glands. Mammary glands of systemically immunized ewes stimulated 5 days previously with staphylococcal soluble antigens (SSA) supported larger neutrophil influxes during staphylococcal infection than contralateral glands stimulated with endotoxin 5 days prior to infection. Exudates of SSA-stimulated glands had significantly higher cell concentrations, prior to infection, than endotoxin-stimulated glands; however elevated cell concentrations in endotoxin-stimulated glands of nonimmune ewes did not support enhanced inflammatory responses. These findings suggest that qualitative but not quantitative characteristics of mammary leucocytes influence the inflammatory response to infection in systemically immunized ewes.

Animals↗
PubMed1982

Effect of immunisation on the early influx of neutrophils during staphylococcal mastitis in ewes.

The neutrophil influx into mammary secretions was studied in unimmunised, and in systemically and locally immunised, lactating and non-lactating ewes experimentally infected with Staphylococcus aureus. Systemic immunisation was effected by subcutaneous injection of live bacteria or by intramuscular injection of killed bacteria in Freund's incomplete adjuvant. The initial inflammatory response to infection of the mammary glands of systemically immunised lactating ewes was at first comparable with that for unimmunised, lactating ewes. However by eight hours after challenge the leucocyte concentrations were lower in systemically immunised ewes. In non-lactating ewes immunised with live vaccine, higher leucocyte concentrations and higher proportions of neutrophils were recorded four hours after infection (hpi) than for unimmunised ewes or ewes immunised with killed vaccine. Prior local immunisation, by unilateral infusion of killed bacteria into mammary glands, enhanced the initial neutrophil influx in comparison to infection of unimmunised contralateral glands of non-lactating ewes by four hpi. For these animals the proportion of neutrophils in washings from immunised glands were significantly greater than for unimmunised glands four and six hpi. In two of three locally immunised lactating ewes there was a larger neutrophil influx into secretions of locally immunised glands than unimmunised glands six hpi. Neutrophils comprised more than 93 per cent of leucocytes from all infected glands by eight hpi. The results suggest that differences in the rate of influx of neutrophils into infected mammary glands of immunised and unimmunised ewes could be attributed to immunological enhancement of neutrophil recruitment or to limitation of toxic damage to tissues with consequently diminished neutrophil invasion.

Animals↗
PubMed1982

Virulence of Staphylococcus aureus grown in vitro or in vivo.

Paired comparisons were made of various strains of Staphylococcus aureus grown in broth inside dialysis sacs anchored in the peritoneal cavities of sheep (in vivo culture) and in a variety of bacteriological media in the laboratory (in vitro culture). The organisms grown in vivo possessed enhanced virulence compared with in vitro grown organisms, when injected intradermally in sheep, when injected intraperitoneally in mice and when infused into lactating mammary glands of ewes. Growth under in vivo conditions conferred on the bacteria an increased resistance to phagocytosis by bovine neutrophils. The bacteria grown under in vivo conditions possessed an additional cell-associated component as determined by immunodiffusion tests and optic density profiles of gel filtration eluates; however, this substance was not visible in electron micrographs in the form of a capsule.

Animals↗
PubMed1981

The influence of immunization with live or killed Staphylococcus aureus vaccines on the early development of opsonizing and bactericidal factors in lymph and blood of sheep.

In order to obtain sensitive measurements on the synthesis of opsonins following immunization with live or killed S. aureus vaccines, lymph was collected from the efferent popliteal lymphatic duct of sheep during the early phase of the immune response. Lymph and blood serum were assayed for opsonizing capacity using 3H-labeled S. aureus. Within 1 hr after vaccination there was a rapid, transitory decrease in uptake by neutrophils of bacteria opsonized with lymph from sheep given the killed vaccine (Group 2). These results were in contrast to the relatively constant uptake rates of bacteria opsonized with lymph from sheep given the live vaccine (Group 1) and non-vaccinated controls (Group 3) at this time. At 72, 96, and 120 hr post-injection mean uptake values for bacteria opsonized with lymph from either vaccinated group were significantly greater than comparable values for controls. Mean uptakes for organisms opsonized with blood serum from Group 1 at 72 and 96 hr post-injection were significantly greater than comparable values for the control group. The percentage of viable neutrophil-associated bacteria decreased when lymph collected from animals in Group 2 in the first hour post-injection was used to opsonize the organisms. Percentages of viable, neutrophil-associated S. aureus for assays in which blood serum was used to opsonize remained relatively constant at around 45% for Groups 2 and 3. In contrast, however, values of viable neutrophil-associated bacteria for Group 1 decreased during the 120 hr after immunization.

Animals↗
PubMed1981

Immunisation against experimental staphylococcal mastitis in sheep - effect of challenge with a heterologous strain of Staphylococcus aureus.

Ewes were immunised in late pregnancy with killed Staphylococcus aureus vaccines prepared from organisms grown either under in vitro (vaccine T) or in vivo (Vaccine V) cultural conditions; other ewes were immunised with a live S. aureus vaccine and a further group remained non-vaccinated controls. The animals given either of the killed vaccines developed highest titres of agglutinating antibody in serum; there were only trivial levels of agglutinating antibody in milk from ewes in each treatment group. Ewes immunised with the live vaccine developed significantly greater levels of opsonins in serum than did those immunised with the killed vaccines or non-immunised controls. At 30 to 35 days post-partum the ewes were challenged by intramammary infusion of one million S. aureus of a strain different to the vaccination strain. In 4 of the 5 control ewes this resulted in the development of acute mastitis and a precipitous decline in milk production, whereas there was a considerable degree of resistance recorded in animals in each of the vaccinated groups. On criteria of milk production data, bacteriological status of milk and clinical signs of acute mastitis it was apparent that animals which had been immunised with the live vaccine were better protected from challenge than those immunised with either killed vaccines T or V.

Animals↗
PubMed1980

Failure to stimulate a local immune response in the mammary gland of the sow using intraperitoneal "priming".

An experiment was carried out to determine whether a local immune response could be produced in the mammary gland of sows by "priming" the animals with an intraperitoneal injection of antigen without adjuvant. Adjuvant was not used in the immunization regimen because it had been shown to induce acute peritonitis and multiple abscess formation when injected intraperitoneally in pigs. Four pregnant sows were "primed" by intraperitoneal injection of ferritin; a second dose of the antigen was given two weeks later into the lumen of the jejunum. Another group of pregnant sows was given two intra-muscular injections of ferritin two weeks apart and a third group of sows served as non-immunized controls. Antibody titres and concentrations of IgG, IgA and IgM in colostral and milk whey suggested that a local immune response had not been stimulated in the mammary glands of these sows. Mammary tissue was examined for the presence of immunoglobulin-containing and specific antibody-containing plasma cells. Results of these studies confirmed that intraperitoneal/intrajejunal injection of ferritin without adjuvant was not successful in inducing a local immune response in the mammary gland.

Animals↗