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Biomedical subjects

A Morris

Publications and source records attributed to A Morris.

At least 217 records · Page 12Linked to original sources
PubMed1988

First trimester diagnosis of Gaucher disease in a fetus with trisomy 21.

A 38-year-old lady, who had a previous infant with type 2 Gaucher disease, underwent prenatal diagnosis by chorionic villus sampling at 9 weeks' gestation. Results on the fresh villus revealed a 47,XY,+21 karyotype and a marked deficiency (2 per cent of control) of beta-glucosidase activity. Following termination, villus material was cultured which initially revealed only a partial enzyme deficiency and a normal female karyotype, i.e., maternal cells. A subsequent culture contained 47,XY,+21 cells which were deficient in beta-glucosidase activity, thus confirming the diagnosis. The results in this interesting case illustrate the potential dangers of maternal cell contamination in cultured villus cells.

Down Syndrome↗
PubMed1988

MHC class I expression by developmental tumors: teratocarcinoma stem cells are TCA positive.

We have investigated the expression of antigens recognized by several alloantisera and monoclonal antibodies to class I and class I-like MHC gene products on four developmental tumor cell lines derived from teratocarcinoma and choriocarcinoma. The analysis by cytotoxicity, immunoprecipitation, and Northern blotting analysis was also performed following treatment of the cells with gamma interferon. Three of four of the cell lines apparently do not express polymorphic determinants of HLA-A,B,C class I MHC genes. Immunoprecipitation with antibodies to HLA monomorphic determinants or beta 2m showed that some cell lines express distinct novel class I MHC-like molecules; the latter show molecular sizes different from regular HLA molecules and are associated with beta 2m. The Northern blotting showed class I mRNA present in three out of four of the developmental tumor cell lines but at at least tenfold lower levels than in lymphoid cells; it is possible that the RNAs homologous to class I DNA probes include transcripts of non-HLA-A,B,C genes. The cells were serologically typed for one such locus, TCA, which lies telomeric to HLA-A; the choriocarcinomas are negative and the teratocarcinomas are positive. The relationship between the different antigenic molecules and their possible functional significance is discussed in terms of maternofetal interactions, cancer, and transplantation.

Choriocarcinoma↗
PubMed1988

Nonsteroidal anti-inflammatory drug-induced dyspepsia--is Campylobacter pyloridis implicated?

An endoscopic study of 34 patients with rheumatic diseases taking nonsteroidal anti-inflammatory drugs (NSAIDs) was undertaken to evaluate whether dyspepsia was associated with Campylobacter pyloridis. Twenty-two patients had an indication for upper gastrointestinal endoscopy and 12 patients were asymptomatic volunteers. Dyspepsia did not correlate with the macroscopic findings at endoscopy, the presence of histological gastritis or the presence of C. pyloridis. However, this study did demonstrate that macroscopic mucosal changes, histological gastritis and the presence of C. pyloridis have an equal prevalence in asymptomatic volunteers and symptomatic patients.

Adult↗
PubMed1988

Distribution of Campylobacter pylori in the human stomach obtained at postmortem.

The distribution of Campylobacter pylori, its prevalence, and its relationship to gastritis and urease activity have been studied in 54 postmortem stomachs. Infection was confirmed by finding C. pylori in a Gram-stained smear of gastric mucus harvested from the entire stomach. Eight tissue specimens were obtained from predetermined sites from each stomach and examined for histologic gastritis and urease activity. Thirty-seven per cent of stomachs were infected, and of these 80% had widespread histologic gastritis. The detection of urease activity provided information on the distribution of the organism and had a high correlation with histologic gastritis. The organism is capable of infecting any area of the stomach. Infection is common and is more prevalent in Polynesian subjects (60%) than in Caucasians (19%).

Adolescent↗
PubMed1988

Na+/H+ ion-exchange property of postmortem human gastric mucus.

The Na+/H+ ion-exchange property of human gastric mucus and its relationship to age has been studied. Mucus was collected from 40 postmortem human stomachs (age range, 21-83 years) within 24 h of traumatic death. Twenty-one stomachs (age range, 21-76 years) were free of Campylobacter pylori infection and histologic gastritis. Mucus from these stomachs was consistently a cation exchanger at pH 6 in an in vitro system. The cation-exchange capacity of mucus from seven stomachs within the age range 55-70 years was 50% less than the cation-exchange capacity of mucus from eight stomachs within the age range 20-35 years. This study shows that human gastric mucus at pH 6 is a cation exchanger and that the ion-exchange capacity decreases with age.

Adult↗
PubMed1988

Dark focus measured in Navy jet tactical fighter pilots.

Visual accommodation was measured with the laser-Badal optometer in 98 U.S. Navy fighter pilots who were in a dark environment without visual stimuli. The average dark focus of the pilots was 0.25 diopters of myopia; 40% were either emmetropic or hyperopic in the dark. Only 4% had as much dark myopia as 50% of a sample of 220 college students. Although the jet fighter pilots, as a population, differed from college students in terms of dark focus, it remains to be determined whether the remarkable dark focus of the pilots was a function of training or selection. The dark focus measurements of the pilots were compared to their mean night carrier landing scores and their mean target detection slant range scores--the distance at which an adversary aircraft is first sighted during an air combat maneuver training engagement. Neither the night carrier landing scores nor the target detection slant range scores correlated significantly with dark focus measurements.

Adult↗
PubMed1987

Infection of cultured murine brain cells by Semliki Forest virus: effects of interferon-alpha beta on viral replication, viral antigen display, major histocompatibility complex antigen display and lysis by cytotoxic T lymphocytes.

Primary brain cell cultures prepared from newborn mice were infected with Semliki Forest virus (SFV). The effects of interferon (IFN-alpha beta) treatment on SFV replication, SFV and major histocompatibility complex (MHC) class I antigen expression, and susceptibility to lysis by SFV-specific cytotoxic T lymphocytes (CTL) were determined. The IFN-alpha beta treatment prevented replication of SFV as determined by incorporation of [3H]uridine into SFV RNA and very markedly reduced the expression of SFV antigens on the cell surface as determined by lysis with antibody and complement or indirect immunofluorescence. However, IFN-alpha beta increased expression of MHC class I antigens, measured by indirect immunofluorescence and as assessed indirectly by susceptibility to killing by alloreactive T cell lines. SFV infection had no effect on MHC class I expression in either IFN-alpha beta-treated or -untreated cells. The infected IFN-alpha beta-untreated brain cells were susceptible to killing by the CTL at effector/target ratios in the range 3 to 30. The killing was MHC antigen-restricted, and uninfected cells were not killed. A target cell (YAC) highly susceptible to natural killer cell cytotoxicity was not killed by the CTL. IFN-alpha beta treatment prior to SFV infection resulted in an augmentation of lysis by the CTL, indicating that even where SFV antigen expression is reduced, in the context of enhanced MHC class I expression brain cells remain susceptible to CTL killing.

Animals↗
PubMed1987

Infective endocarditis. Current recommendations for prophylaxis.

Antibiotic prophylaxis is indicated for any patient with a predisposing cardiac lesion who undergoes a procedure likely to produce bacteraemia with an organism having the propensity to cause bacterial endocarditis. Cardiac abnormalities have been ranked according to their approximate risk and it is known that the organisms most likely to cause endocarditis are viridans streptococci, Group D streptococci and staphylococci. The procedures likely to induce bacteraemia with each of these are, respectively, dental and upper respiratory with bleeding, urinary and gastrointestinal, and cardiac valve surgery. Antibiotic prophylaxis is impractical when bacteraemia cannot be anticipated and is unnecessary when it is due to organisms such as anaerobes and Gram-negative bacilli which rarely colonise the endocardium. A variety of prophylactic antibiotic regimens, directed against the common aetiological organisms, have been evaluated in animal models of infective endocarditis and it is on the basis of this kind of indirect evidence that several expert committees have made and regularly update their recommendations. Because infective endocarditis is an uncommon disease, a controlled clinical trial to prove the efficacy of prophylaxis would require the enrolment of a prohibitive number of patients. Consequently, there is room for differences of opinion over what constitutes optimum prophylaxis in any particular situation. This review examines the rationale for prophylaxis and compares and contrasts several authoritative recommendations, among which the trend in recent years has been towards simpler oral regimens.

Anti-Bacterial Agents↗
PubMed1987

Ingestion of Campylobacter pyloridis causes gastritis and raised fasting gastric pH.

Campylobacter pyloridis was ingested by a volunteer who had a histologically normal gastric mucosa and fasting gastric pH recordings of less than 2. Three days later he developed moderate to severe attacks of epigastric pain. On the 5th day after ingestion C. pyloridis was cultured from antral biopsies which showed histological acute gastritis. However, fundal histology and fasting gastric pH were normal. On the 8th day fasting gastric pH rose to 7.6. On day 11 C. pyloridis was cultured from both antral and fundal biopsies which showed histological gastritis. Doxycycline was taken for 28 days but infection and gastritis persisted. Bismuth subsalicylate was taken for 28 days and final biopsies, taken 1 wk after stopping therapy, were culture negative. Histology showed a minimal residual chronic gastritis. C. pyloridis can cause an acute upper gastrointestinal illness associated with histological gastritis and an increase in fasting gastric pH.

Acute Disease↗
PubMed1986

Seroepidemiology of Campylobacter pyloridis.

A total of 1158 sera were tested by an enzyme linked immunosorbent assay (ELISA) for IgG and IgA antibodies to Campylobacter pyloridis. When used to test sera from gastroendoscopy patients this method had a sensitivity of 91% and a specificity of 75%. Ninety-eight of 108 infected patients (91%) were seropositive whereas only 23 of 92 (25%) uninfected patients were seropositive (p less than 0.001). Positive serology was also associated with histological gastritis (p less than 0.001). When sera from occupational groups were compared to random blood donor sera, meat workers, freezing works veterinary surgeons and pest control officers had significantly higher seropositivity. Cook Island (33 of 85 (39%)), Samoan (57 of 129 (44%)) and Tongan (39 of 56 (70%)) blood donors also had greater seropositivity than random blood donors (15 of 102 (15%)), (p less than 0.001 for all three ethnic groups). Seropositivity increased with age. The results indicate that C pyloridis infection is common among certain groups within New Zealand. The implication of this finding with respect to the hypothesis that C pyloridis is aetiologically related to dyspepsia and peptic ulcer disease is discussed.

Adolescent↗
PubMed1986

Campylobacter pyloridis infection in Auckland patients with gastritis.

A prospective study of 53 patients was undertaken to determine the presence of Campylobacter pyloridis infection in patients undergoing endoscopy at Auckland Hospital. Twenty-four patients (47%) were infected with C pyloridis. Twenty-three of the 28 patients with active chronic gastritis and one of the seven patients with chronic gastritis were infected. None of the 17 patients with normal antral histology were infected. Infection was significantly correlated with active chronic gastritis (p less than 0.001). Infection was not associated with any particular symptom complex or endoscopic finding.

Adult↗
PubMed1986

The interaction of interferon with the immune response.

Interferon (IFN) is a component of the immune response and influences immune responses as demonstrated by in vitro experimentation. In this review these complementary aspects of IFN's interaction with the immune response are discussed. Of chief interest is IFN-gamma ('immune' IFN) but IFNs-alpha and -beta are also considered.

Animals↗