Search PubMedSearch

Biomedical subjects

S Sutherland

Publications and source records attributed to S Sutherland.

At least 19 recordsLinked to original sources

Donated organ as a source of cytomegalovirus in orthotopic liver transplantation.

The importance of the donated organ as a source of CMV was assessed in 120 patients following orthotopic liver transplant and the CMV infections that developed in these patients were graded by severity. Forty-four recipients were CMV antibody negative pre-transplant. Eighteen of these received organs from CMV antibody positive donors and 15 (83%) developed primary CMV infections, 13 (87%) of which were symptomatic. Twenty-six received organs from CMV antibody negative donors and only 2 (8%) became CMV positive post transplant (P less than 0.001). These data suggest that there would be a considerable advantage in matching CMV antibody negative recipients with negative donors. Forty-five percent of secondary infections were asymptomatic compared with 12% of primary infections, and only 11% became disseminated compared with 53% of primary infections. The secondary infections that followed transplantation of an organ from a CMV antibody positive donor were more likely to be symptomatic and were more severe than those in patients who received seronegative livers.

Antibodies, Viral

Intrafamilial phenotypic expression of autosomal dominant polycystic kidney disease.

It has been suggested that the clinical expression of autosomal dominant polycystic kidney disease (ADPKD) is uniform among individuals of a given family. To test this hypothesis, intrafamilial variations in ages at onset of first symptoms, types of first symptoms, serum creatinine concentrations, and renal sizes were evaluated in 131 patients with ADPKD from 36 unrelated families. These parameters were compared in younger and older affected relatives in the same family at a single time, due to difficulties of following them longitudinally. Because the natural course of the disease is to progress with age, it was presumed that disease progression in a given family was nonuniform if older individuals had lower serum creatinine concentrations, and/or smaller kidneys than their affected younger relatives, or if relatives of similar ages had different serum creatinine concentrations and/or kidney sizes. Nonuniform progression was suggested in 38% of affected relatives by serum creatinine concentrations and in 53% by kidney sizes. Ages at onset of first symptoms and types of first symptoms were also different in patients from the same families. These data indicate that phenotypic expression of ADPKD may differ considerably among patients who belong to the same families.

Adolescent

Detection of HIV in haemopoietic progenitors.

Peripheral blood cytopenias present a major problem in the management of patients with HIV infection. Their pathophysiology is likely to be multifactorial, although there is controversy as to whether haemopoietic progenitors are a target for HIV. In order to investigate the haemopoietic defect in HIV infection, we looked at bone marrow culture characteristics of marrow from eight HIV+ patients compared to normal controls. We performed long-term liquid culture (LTC) and colony forming assays for granulocyte-macrophage (CFU-GM) and granulocyte, erythroid, megakaryocyte, macrophage (CFU-GEMM). In LTC we found normal stromal appearance and haemopoietic focus formation. There was no difference in colony assays of CFU-GM and CFU-GEMM between HIV+ and normal controls. Colonies taken from CFU-GM and CFU-GEMM were analysed for HIV DNA sequences, and we were able to detect HIV DNA in colonies from all HIV+ patients. Our results indicate that despite infection of haemopoietic progenitor cells by HIV, bone marrow function is preserved. This suggests that HIV-related cytopenias may be due to alternative mechanisms not present in our in vitro system.

Adult

A serological investigation of human herpesvirus 6 infections in liver transplant recipients and the detection of cross-reacting antibodies to cytomegalovirus.

Sera from 50 orthotopic liver transplant recipients were examined for antibodies to human herpesvirus 6 (HHV-6) and cytomegalovirus (CMV), and the findings correlated with the clinical condition of the patients. Both primary and secondary HHV-6 infections were detected serologically following liver transplantation. Interpretation of serological assays is complicated by CMV and HHV-6 antibody cross reactions which were common. Sera from 5 patients became HHV-6 antibody negative following absorption with CMV infected cells. Thirty patients were initially seronegative for HHV-6 antibodies, 12 remained so following transplantation, 5 developed cross reacting antibodies, and 13 seroconverted. The seroconversions occurred at 4 to 8 weeks post-transplant in the same time period as CMV antibody rises. HHV-6 IgM was detected in only 4 of the 13. Of the 7 patients who had serological evidence of active HHV-6 infections but no evidence of CMV infection, 4 (56%) had fever, 1 (14%) hepatitis, 1 (14%) lung dysfunction, and 3 (42%) neurological disorders. In the 12 patients who remained HHV-6 antibody negative, there were fewer fevers and neurological disorders.

Antibodies, Viral

Identification of jack-jumper ant (Myrmecia pilosula) venom allergens.

Jack-jumper ant venom proteins were electrophoretically separated on SDS-polyacrylamide gels, transferred to nitrocellulose and probed with sera from subjects who had experienced an allergic reaction after being bitten by a jack-jumper ant. Ant venom components that bound IgE antibodies were detected by addition of 125I-anti-human IgE followed by autoradiography. Of the 17 polypeptides resolved by electrophoresis only three, of molecular weights approximately 14 kD, 12 kD and 10 kD, bound IgE antibodies from the panel of 50 sera examined. There was a marked similarity in the binding patterns by individual sera with almost all of the sera recognizing the 14kD and 12 kD components. IgE-binding profiles of separated ant venoms from ants collected in different regions of Australia appeared to be very similar if not identical. Identification of the ant allergens is a necessary prelude to the preparation of standardized venom sac extracts suitable for safe and effective diagnostic and therapeutic use.

Allergens

The efficacy of antivenom in prevention of cardiovascular depression and coagulopathy induced by brown snake (Pseudonaja) species venom.

The efficacy of antivenom in prevention of cardiovascular depression and coagulopathy induced by Brown Snake species (Pseudonaja textilis, Pseudonaja affinis) was investigated in anaesthetised mechanically ventilated dogs. Venom and antivenom in variable amounts were incubated together at 37 degrees C for 30 minutes prior to intravenous injection. The dose of antivenom required to prevent severe cardiovascular depression and coagulopathy induced by Pseudonaja textilis venom was 25 times the current recommended dose for clinical use. A tenfold dose of antivenom was required to neutralise similar effects induced by Pseudonaja affinis venom. Large amounts of antivenom may be required in clinical use if coagulopathy or cardiovascular depression are present after envenomation by species of the Brown Snake genus.

Animals

The effect of genetic determinants of low density lipoprotein levels on lipoprotein (a).

Levels of Lipoprotein(a) [Lp(a)] correlate directly with atherosclerosis risk. The Lp(a) particle is physically and chemically similar to low density lipoprotein (LDL), the main difference being the presence of apolipoprotein(a) [apo(a)] bonded to the apoB-100 moiety of LDL. Genetic variation of apo(a) primarily determines Lp(a) phenotype. However, other genetic factors may also have a role in determining Lp(a) levels. Large families provide a unique opportunity to evaluate the contribution of genetic factors to disease. In several large Utah kindreds with various genetic abnormalities of lipoprotein metabolism we determined that: 1) Lp(a) levels are associated with defects at the apoB gene; 2) Lp(a) levels are not associated with defects at the LDL-receptor gene; 3) high density lipoprotein (HDL) levels are associated with genetic variation at the apo(a) locus; and 4) the DNA sequence of the apoB-100 binding domain does not vary between siblings with high and low Lp(a) levels.

Apolipoprotein B-100

Factors that influence the prevalence of positive catch trials in glaucoma patients.

We evaluated factors that influence the catch-trial response in automated perimetry by consecutively examining 408 glaucoma patients (703 eyes) with either the program 30-2 or a 76-point screen with a quantified defect on the Humphrey Field Analyzer. The prevalence of positive catch trials using both programs was: 15.9% fixation losses, 5.5% false-positives, and 17.0% false-negatives. The only significant difference between the two programs was a lower prevalence of false-negatives on the program 30-2 (P less than 0.01). False-positive responses showed a significant positive correlation to fixation losses, and the catch trial response in general was correlated significantly to defect depth, test time, age, and visual acuity (P less than 0.05). This study suggests that the prevalence of positive catch trials is not an independent variable when testing glaucoma patients with automated perimetry and is not reduced by using a screening strategy over a full-threshold exam.

Adolescent

Clinical manifestations of autosomal dominant polycystic kidney disease in patients older than 50 years.

The purpose of this study was to define manifestations of autosomal dominant polycystic kidney disease (ADPKD) in older patients with the disease. Fifty-seven subjects age 50 years or more, who were at risk for having inherited the gene for ADPKD, were evaluated for renal size, hypertension, back and abdominal pain, symptoms consistent with urinary tract infection (UTI), hematuria, end-stage renal failure, and liver cysts. The diagnosis of ADPKD was made in 32 of the 57 at-risk subjects (56%). At the time of study, only one patient with the disease was asymptomatic and normotensive and denied any previous symptoms suggestive of the disease. Clinical manifestations of ADPKD in the 31 symptomatic patients were hypertension (69%), a history of back and abdominal pain (47%), symptoms consistent with UTI (41%), hematuria (31%), and end-stage renal failure (47%). Liver cysts were found in 44% of patients. No statistically significant differences in the frequency of any manifestations of ADPKD between men and women were found, although the frequency of symptoms consistent with UTI tended to be higher in women (53%) than in men (27%). Most patients developed symptoms after the age of 40 years. Notably, 31% of the older patients with ADPKD had normal serum creatinine levels. Thus, older subjects with kidney cysts who are at risk to have inherited the gene for ADPKD, should be considered to have the disease even in the presence of well-preserved kidney function. This observation may play an important role in assessing the prognosis of older subjects at risk who have bilateral renal cysts and in genetic counseling of their relatives.

Abdominal Pain

Seroprevalence of HIV-1 infection in a cohort of homosexually active men.

A non-clinic cohort of 525 homosexually active men from London and South Wales were recruited in 1988 for a study by interview of sexual behaviour. A sample of blood was tested for HIV-1 antibodies. Seropositivity in London was 9.2% compared with 3.4% in South Wales. Men who were not regular STD clinic attenders had a lower rate of seropositivity than did those who were regular attenders. Men who were seropositive reported more sexual partners with whom they had anal intercourse and also reported more episodes of syphilis. Overall, rates of seropositivity were lower than those reported by studies from STD clinics.

Adolescent

Studies on Australian snake venoms. Part 1: The haemodynamic effects of brown snake (Pseudonaja) species in the dog.

The haemodynamic effects of Brown Snake (Pseudonaja) species (textilis, nuchalis, affinis) were investigated in anaesthetised, mechanically ventilated dogs. Blood pressure decreased to minimal levels five minutes after intravenous envenomation. Hypotension was accompanied by significant decrements in cardiac output and stroke volume and a rise in peripheral vascular resistance. Heart rate increased transiently during 0.5-2.0 minutes after envenomation but had declined below resting levels five minutes after envenomation. No statistically significant change was recorded in central venous pressure. Depression of myocardial contractility is postulated as the mechanism of venom induced hypotension.

Animals

Cytomegalovirus infection and donor/recipient HLA antigens: interdependent co-factors in pathogenesis of vanishing bile-duct syndrome after liver transplantation.

The contribution of cytomegalovirus (CMV) infection and its interrelation with HLA antigens in the development of chronic rejection (vanishing bile-duct syndrome--VBDS) was investigated in 101 patients surviving for at least 3 months after liver transplantation. A 1-2 antigen match for HLA DR antigens (30.9% vs 4.5% for zero DR match; p less than 0.002), a zero match for HLA A/B antigens (27.5% vs 10.9% for 1 or more A/B match; p less than 0.05), and active CMV infection (26.3% vs 4.4% for no CMV infection; p less than 0.005) were independently associated with an increased risk of VBDS. The coexistence of a 1-2 HLA DR match and CMV infection carried the highest relative risk (10.1) of VBDS; these two variables were probably interdependent since either alone was associated with a low relative risk (0.45 and 0.5). The association between VBDS and active CMV infection was not a consequence of alterations in immunosuppressive therapy. The findings would be consistent with precipitation of chronic rejection by CMV-induced HLA antigen expression in patients rendered susceptible by the donor/recipient HLA antigen match.

Adolescent