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Biomedical subjects

T White

Publications and source records attributed to T White.

At least 145 records · Page 8Linked to original sources
PubMed1989

Glomerular filtration rate up to 10 years after urinary diversion of different types. A comparative study of ileal and colonic conduit, refluxing and antirefluxing ureteral anastomosis and continent caecal reservoir.

To evaluate the influence of conduit type (ileal or colonic) and method of ureterointestinal anastomosis (refluxing or antirefluxing) on renal function in patients with urinary diversion, a prospective randomized trial was conducted in 1977-1984. During these years urinary diversion via a continent caecal reservoir emerged as an alternative to conduit diversion at our hospital, and these patients with continent reservoir were also included in the study. Total and separate glomerular filtration rate (GFR) were measured, the latter with scintillation camera renography, preoperatively and at follow-up in 70 patients. Measurements 2-10 years postoperatively showed slight to moderate decrease of GFR in all groups, with no significant difference between values according to conduit type or caecal reservoir or between refluxing and antirefluxing ureterointestinal anastomosis. Almost all of the anastomotic strictures involved the ureter that had been brought beneath the sigmoid mesentery, indicating that ischemia secondary to extensive ureteral mobilization is a likely cause of stricture in these cases.

Anastomosis, Surgical↗
PubMed1989

Partial brain dopamine D2 receptor agonists in the treatment of schizophrenia.

Partial dopamine agonists showing high affinity but low efficacy at D2 receptors can act as dopaminergic "buffers," reducing dopaminergic activity when it is excessive, and promoting it when reduced. This makes them of interest as potential therapeutic agents for the treatment of both positive and negative symptoms in schizophrenia, where they should also result in fewer or less severe motor disturbances than classical neuroleptics. SDZ 208-911 and SDZ 208-912 are amino-ergolines exhibiting partial agonistic properties in the rat, where they inhibit apomorphine-induced stereotypies, are only weakly cataleptogenic, induce varying degrees of circling behavior after unilateral lesioning of the nigrostriatal pathway, and strongly suppress prolactin secretion. The least agonistically acting agent, SDZ 208-912, should be effective against positive symptoms, whereas SDZ 208-911 could be suitable for the treatment of negative symptoms. In addition to possible therapeutic effects, the clinical testing of this class of agent should help to elucidate the status of central dopaminergic function in schizophrenic psychosis.

Brain Chemistry↗
PubMed1988

5-Hydroxytryptamine releases adenosine from primary afferent nerve terminals in the spinal cord.

5-Hydroxytryptamine (serotonin, 5-HT) increased the release of endogenous adenosine from dorsal, but not ventral, spinal cord synaptosomes. This release was reduced by (i) the 5-HT receptor antagonist methysergide, (ii) removal of Ca2+ from the medium, (iii) inhibition of ecto-5'-nucleotidase and (iv) capsaicin pretreatment. These data suggest that activation of 5-HT receptors on primary afferent terminals releases a nucleotide which is converted extracellularly to adenosine. This adenosine may contribute to the spinal antinociceptive effect of 5-HT.

Adenosine↗
PubMed1988

Immunoblotting studies of the molecular forms of protein C in plasma.

Anti-plasma protein C monoclonal antibodies were prepared and characterized, and quantitative immunoblotting techniques were developed to determine the molecular forms of protein C in whole plasma. Two antibodies reacted with the heavy chain of protein C, four reacted with the light chain, and two reacted only with nonreduced protein C. A doublet of protein C (MW = 63-66K) was seen on nonreduced immunoblots of normal plasma and 30 heterozygous protein C deficient plasmas (2-77% protein C antigen). In reduced plasma, approximately 75% of protein C presented as doublet heavy chains (MW = 39-42K) and doublet light chains (MW = 22-25K), and approximately 25% was single chain (MW = 64K). The immunoblotting technique was quantitative, specific, sensitive, and correlated with electroimmunoassay results. It also provided visual qualitative information not obtainable with other methods of quantitation.

Antibodies, Monoclonal↗
PubMed1988

Quantitative evaluation of tomographic 201-thallium myocardial scintigraphy.

Myocardial 201Tl emission computed tomography was performed on 25 normal subjects and 27 patients with angiographically significant coronary artery disease. A semi-automatic computer program was designed to define the left ventricular myocardial volume in all short axis sections. Within this volume the relative mean myocardial pixel count was calculated. This parameter was found to separate the 2 patient groups with a sensitivity of at least 81% at a specificity of 100%.

Adult↗
PubMed1987

Low serum iron status and akathisia.

26 patients were studied to assess the association between iron deficiency and akathisia. 13 akathisic patients were matched with 13 non-akathisic controls. Serum iron and percentage saturation were significantly decreased in the akathisic group, whereas total iron-binding capacity was significantly increased. A negative correlation between serum iron and akathisia rating (rs = -0.42) was also found.

Akathisia, Drug-Induced↗
PubMed1987

Evaluation of renal parenchyma in children by DMSA scintigraphy, X-ray computed tomography and intravenous urography.

The demonstration of diminished or scarred renal parenchyma in children is often the decisive factor in determining the future management of children with urinary tract malformations. Renal scintigraphy using technetium 99m-labelled dimercaptosuccinic acid (DMSA), computed tomography (CT) and intravenous urography (IU) were used to evaluate the renal parenchyma prior to ureter re-implantation in a series of 13 children. Their ages ranged from 5 months to 3 years 8 months. The indication for operation was ureteric reflux in 8 children and distal ureteric stenosis in 5. CT was performed on a Toshiba TCT-80 scanner. Renal scintigraphy was performed 3 hours after intravenous injection of DMSA. Compared with IU, DMSA imaging gave more information about the renal parenchyma in 6 children, gave equal information in 6 and less in 1. Compared with CT, DMSA imaging gave more information in 2 children, was equally informative in 8 and less so in 3. Accordingly, DMSA imaging was judged to be more sensitive than IU and as sensitive as CT. DMSA imaging can be used both for the initial evaluation and for follow-up assessment of renal parenchymal damage.

Child, Preschool↗
PubMed1986

Studies on renal damage from percutaneous nephrolitholapaxy.

To study in detail the effects of percutaneous nephrolitholapaxy on renal function, a consecutive series of 11 patients were investigated preoperatively by excretory urography, gamma camera renography for determination of individual renal function and computerized tomography of the kidneys. Postoperatively, gamma camera examination, computerized tomography, antegrade nephrostography, renal angiography and excretory urography were performed. With 2 exceptions, percutaneous nephrostomy, dilation of the tract and stone removal were done in 1 stage with the patient under continuous epidural anesthesia. Nephrostomy tract dilation was done with an Olbert type balloon catheter or Alken metallic dilators. Thickening of Gerota's fascia was demonstrated by computerized tomography in most cases, and small to moderate perirenal hematomas were found in several. At gamma camera examination decrease of renal function was noted regularly on postoperative day 1 and returned to near initial levels 2 weeks postoperatively in most cases. Angiography in 10 patients showed discrete parenchymal scarring in some and a peripheral arteriovenous fistula in 1. We conclude that percutaneous renal stone surgery usually is tolerated well by the kidney.

Adult↗
PubMed1986

Detection of in vitro and in vivo cleavage of high molecular weight kininogen in human plasma by immunoblotting with monoclonal antibodies.

Purified human high-mol-wt kininogen (HMWK), the cofactor of the contact phase of blood coagulation, migrated as a single band (approximately 110,000 mol wt) in a continuous buffer sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), but appeared as two separated bands (approximately 120,000 and 105,000 mol wt) when analyzed in a discontinuous buffer SDS-PAGE system. After elution from SDS polyacrylamide gels, each of the two bands showed coagulant activity. Six murine monoclonal antibodies (Mabs) against HMWK were produced and purified. In immunoblotting studies, three Mabs bound to the isolated alkylated heavy chain and one to the alkylated light chain of HMWK, whereas the remaining two bound only to the single-chain or unreduced two-chain molecule. None of the Mabs inhibited the clotting activity of HMWK or its binding to kaolin. Two of the Mabs, one directed against the light chain and one against the heavy chain, were used as specific probes to study HMWK in plasma samples using an immunoblotting technique. The anti-light chain Mab identified two distinct bands (approximately 120,000 and approximately 105,000 mol wt) in normal human plasma, but not in plasma from patients with hereditary HMWK deficiency. The anti-heavy chain Mab detected two additional bands (approximately 60,000 and approximately 54,000 mol wt) corresponding to low-mol-wt kininogen (LMWK) in normal plasma. A sensitive and specific quantitative immunoblotting assay of HMWK antigen in plasma was developed. Moreover, the immunoblotting technique with the anti-light chain Mab was used to detect the cleavage of HMWK in plasma samples after in vitro or in vivo activation of the contact system. The anti-light chain Mab demonstrated in vivo activation and cleavage of HMWK during an angioedema attack in a patient with hereditary angioedema and C1-inhibitor deficiency.

Antibodies, Monoclonal↗
PubMed1985

Incidence of hepatitis A virus (HAV) infection in rural Liberia.

To provide background for future hepatitis A vaccine trials, sera were collected from 0- to 4-year-old Liberian infants and their mothers on two occasions an average of 14.75 months apart and tested for antibody to hepatitis A virus (anti-HAV). The prevalence of anti-HAV rose from 2.5% in infants 0-6 months of age to 70% in children 3-4 years of age and did not differ between male and female infants. The annual incidence of new infections was slightly lower in the first year of life (35%) than in the subsequent 3 years, when it averaged 45%. The presence of HBV infection did not affect the incidence of HAV seroconversion. No clinical hepatitis was recognized in the subjects who seroconverted. Dual hepatitis A and B virus infection were observed; these were all clinically inapparent. The extraordinary incidence of HAV infection documented in the present study offers an opportunity for vaccine efficacy trials requiring minimal numbers of subjects.

Adolescent↗
PubMed1985

Counterphase lightness induction.

When half-cycle wide mid-grey test elements are superimposed on a black and white square wave induction grating, their apparent lightness is a linear function of their phase relationship with the induction grating; being judged lightest when in phase with the black bars of the grating, and darkest when in phase with the white bars. This finding justifies the use of the term "counterphase induction" to describe the effect, and emphasizes the similarity between this effect and McCourt's (1982) [Vision Res. 22, 119-134] grating induction effect. The fact that the same linear function holds whether the test elements are square or rectangular favours a global over a local explanation.

Female↗
PubMed1984

Isolation and sequence analysis of the human apolipoprotein CIII gene and the intergenic region between the apo AI and apo CIII genes.

We have isolated and characterized the gene for human apolipoprotein CIII, a major component of the triglyceride-rich lipoproteins. Determination of the complete DNA sequence of this gene revealed that the coding sequence is interrupted by three introns, which occur in the 5' noncoding region, in the region encoding the signal sequence and in the region coding for the mature plasma protein, respectively. We present an analysis of the structure of the apo CIII gene and compare it to the gene for apolipoprotein AI. In addition, we present the DNA sequence of the intergenic region lying between the apo AI and the apo CIII genes.

Apolipoprotein A-I↗
PubMed1984

Quantitative assessment of individual renal function. A comparison between creatinine excretion and a radionuclide method.

Individual renal function was evaluated in 21 patients. Two methods were used in each case, namely gamma camera renography and measurement of creatinine excretion in urine collected via a nephrostomy. The scintigraphic technique utilized measurement of renal parenchymal radionuclide uptake in an early phase. Good agreement was found between the results from both methods in most patients. Gamma camera renography was found to be clinically useful for assessing the function of individual kidneys.

Adult↗