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Biomedical subjects

D Williams

Publications and source records attributed to D Williams.

At least 505 records · Page 28Linked to original sources
PubMed1984

Klebsiella and acute anterior uveitis.

Samples of the faeces of 153 consecutive patients presenting with acute anterior uveitis (AAU), and of 47 controls were examined for the presence of Klebsiella pneumoniae. No increase in the carriage rate of klebsiella was found in the AAU patients as compared with the controls. Furthermore no increase was found in any group of patients whether subdivided by HLA-B27 status, sex, or presence of ankylosing spondylitis (AS). No difference was found between patients having their first attack of AAU and those with recurrences.

Feces↗
PubMed1984

Penetration of the left ventricular myocardium by benign peptic ulceration: two cases and a review of the published work.

Two cases of penetration of the left ventricular myocardium by benign peptic ulcer are reported. Twenty five similar cases in the world published work are reviewed. The condition is only possible when there are fibrous adhesions between the stomach and diaphragm and the pericardium. In addition, the left lobe of the liver may be small. Alternatively, an ulcer within a hiatus hernia may erode into the left ventricle.

Aged↗
PubMed1984

A comparison of the effects of semisynthetic human insulin and porcine insulin on transmembrane ion shifts and glucose metabolism during euglycaemic clamping.

Disturbances of potassium, calcium, phosphate and magnesium homeostasis in diabetes mellitus are well documented. We have compared the effects of semisynthetic human and pancreatic porcine insulin on transmembrane shifts of these ions, and on glucose metabolism, at two insulin infusion rates, 20 and 50 mU/kg/h, during euglycaemic clamping for 2 h in 6 normal volunteers. The glucose requirements and the changes in blood metabolite concentrations were not significantly different during the porcine and human insulin infusions. Serum potassium levels, however, showed a significant greater decline with infusions of porcine insulin (4.2 +/- 0.1 to 3.5 +/- 0.1 mmol/l) compared with human insulin (4.2 +/- 0.1 to 3.7 +/- 0.1 mmol/l) at 50 mU/kg/h (P less than 0.05). Potassium levels were significantly lower during the porcine insulin infusion at 105 and 120 min and at 15 and 30 min after stopping the infusion. Electrocardiographic T-wave voltage decreased during the porcine and human insulin infusion by 0.13 +/- 0.02 and 0.10 +/- 0.01 mV, respectively (P less than 0.02). Changes in serum levels of magnesium, calcium, phosphate, and red blood cell concentrations of magnesium and 2,3-DPG, were not significantly different between the insulins. Thus a small but significant greater decline in potassium levels with similar glucose requirements was found during iv administration of porcine insulin compared with human insulin.

Animals↗
PubMed1984

Ponticles of the atlas: a review and clinical perspective.

The condition of ponticles of the atlas was reviewed in relation to their development, anatomy, incidence and diagnosis with an objective directed toward assessment of their clinical significance. The ponticles are commonly encountered radiographic anomalies characterized by osseous bridging of the posterior margin of the superior articular facet and the posterior arch of the atlas. They are present to a variable degree in about 35% of dissections and a complete osseous ring enclosing the vertebral arteries is identifiable in up to 15% of cases. The ponticles have been considered a significant factor in transient vertebro-basilar insufficiency, Barre-Lieou syndrome and chronic upper cervical syndrome. The presence of atlantic ponticulus should be considered to some degree as a contraindication to forceful manipulation of the cervical spine.

Cervical Atlas↗
PubMed1984

Lineage switch in acute leukemia.

Conversions of leukemic cell lineage (lymphoid or myeloid) have been reported only rarely. Our review of the cytochemical and immunophenotypic features of 89 cases of childhood leukemia in marrow relapse indicated lineage switch (lymphoid to myeloid or the reverse) in six patients (6.7%). Five patients with acute lymphoblastic leukemia (ALL) at diagnosis had converted to acute nonlymphoblastic leukemia (ANLL), and one had converted from ANLL to ALL. Each child received lineage-specific multiagent chemotherapy when initially diagnosed, and all achieved a complete remission. After conversion, four patients readily achieved second remissions with treatment for the phenotype evident at lineage switch. Two patients with ANLL at conversion failed ALL-directed reinduction, while one of the two responded to high-dose cytarabine but died during bone marrow hypoplasia, emphasizing the importance of prompt recognition of lineage switch and selection of an appropriate plan of retreatment. Cytogenetic studies disclosed evidence of clonal selection in one patient and clonal stability in two. These findings indicate an unexpectedly high frequency of lineage switch in patients who relapse in the bone marrow after intensive chemotherapy. Although specific causative factors could not be identified, our observations suggest at least two general mechanisms for lineage switch in acute leukemia. In one, chemotherapy appears to eradicate the dominant clone present at diagnosis, permitting expansion of a secondary clone with a different phenotype. In the second, drug-induced changes in the original clone may either amplify or suppress differentiation programs so that phenotypic shift is possible.

Acute Disease↗
PubMed1984

Silicone implants in dogs. A ten-year histopathologic study.

The biocompatibility of implanted materials is important to the successful long-term results obtained in reconstructive surgery with these materials. Recently, interest has emerged regarding host response to the wear debris of implanted material. Since 1962 flexible implant materials have been studied in the Orthopaedic Research Department at Blodgett Memorial Medical Center. An important aspect of this study has been a concern for host tolerance and the evaluation of biologic responses to implanted silicone elastomer. Three dogs in which implants of silicone elastomer had been in place for more than ten years were carefully studied by complete autopsy. A benign foreign-body giant cell response to local silicone wear debris was observed. No silicone particles or macrophage giant cell reactions were found in any distant organs. The host response to silicone wear debris was benign, and no adverse systemic influences were noted.

Amputation Stumps↗
PubMed1983

Studies of X-chromosome inactivation with an improved histochemical technique for ornithine carbamoyltransferase.

Studies of X-linked enzymes provide an approach to the study of tumour and normal cellular development. We have assessed the technique for the histochemical demonstration of one such enzyme, ornithine carbamoyltransferase (EC 2.1.3.3). Various stages in the Mizutani technique for ornithine carbamoyltransferase were re-examined, and the resulting improved technique applied to normal mice and to mice of the sparse fur strain (Spf) known to have an abnormal form of ornithine carbamoyltransferase inherited as an X-linked characteristic. Positive enzyme activity was present in all hepatocytes from normal mice, the strongest reaction being present in the periportal area with a gradual reduction of activity towards the centrilobular region. No activity was demonstrable in hepatocytes from hemizygous male Spf mice. In heterozygous female Spf mice, there was a clear-cut separation of ornithine carbamoyl-transferase-positive and -negative cells. These were present in very variable proportions in different liver lobes and different animals. Preliminary studies were also carried out using a high pH reaction mixture to detect the abnormal enzyme. These studies demonstrate conclusively the X-linkage of ornithine carbamoyltransferase in mice, showing the mosaic pattern of distribution predicted by the Lyon hypothesis. They show that the Spf strain of mice can be used for studies of both development and tumorigenesis in the liver, and that histochemical study of an animal strain with an X-linked enzyme abnormality provides a powerful investigative tool.

Animals↗
PubMed1983

Evaluation of the rapid micromethod for ultracentrifugal separation of labeled plasma lipoproteins.

The fractionations of plasma lipoproteins by 2 methods were compared to evaluate the rapid separation (Airfuge) method for lipoprotein distribution studies. When [125I] labeled very low density, low density, and high density lipoproteins (VLDL, LDL, HDL), were separately centrifuged in buffers at d = 1.006, 1.06 or 1.2 g/ml by the conventional ultracentrifuge and the Airfuge, separations of the fractions in the Airfuge were incomplete at both 5 C and 24 C, especially at d = 1.006. [3H] Benzo (a)pyrene, when added to plasma, associates with the plasma proteins and lipoproteins, especially LDL. Compared to the standard techniques, the Airfuge method greatly overestimated its distribution into VLDL. The distribution of [3H] vitamin D3 into the VLDL plus LDL fraction was also overestimated by the Airfuge procedure. It is concluded that caution should be observed in quantitative studies of lipoproteins in the Airfuge. A careful comparison of the distribution into or fractionation of lipoproteins by the 2 methods should always precede any quantitative determinations involving the Airfuge.

Humans↗
PubMed1983

Protective effect of nonspecific immunostimulation in postsplenectomy sepsis.

The enhanced risk of severe sepsis following splenectomy is now well recognized in both adult and pediatric patients. Prophylactic antibiotics and bacterial vaccines have been utilized with limited success to inhibit the high morbidity and mortality. This study reports the use of glucan, a beta-1,3-polyglucose, as a nonspecific immunostimulant for postsplenectomy pneumococcal sepsis. ICR mice were treated with glucan or glucose (5% w/v) following splenectomy or sham operation. Mice were then challenged with 1 X 10(9) Streptococcus pneumoniae intranasally. Glucan significantly increased survival in the splenectomy group (75%) compared to controls (27%). Phagocytic function, as measured by the clearance of 131I-triolein-labeled reticuloendothelial test lipid emulsion, was increased in the glucan group when compared to control glucose animals, both in the presence and absence of pneumococcal infection. Splenectomy alone did not significantly decrease phagocytic function. An increased leukocytosis in response to pneumococcal infection was observed in splenectomized glucan-treated animals. Nonspecific immunostimulation appears to have significant potential as a treatment strategy against postsplenectomy infection.

Animals↗
PubMed1983

On the use of word association norms in aging research.

The word associations of young, middle-aged, and older adults were compared to cohort matched normative word associations. Cohort differences in most common response were observed for a subset of stimulus words which did not have strong primary responses in the norms. For those stimulus words assumed to be free of cohort differences, there were no significant differences between the three age groups in amount of agreement with the normative responses. It is concluded that standard word association norms are as reliable for older individuals as for the young provided that words with strong associates are selected.

Adult↗
PubMed1983

Granular acute lymphoblastic leukemia.

Granules in blasts are most typical of acute myeloblastic leukemia. However, there have been scattered reports of patients with acute lymphoblastic leukemia (ALL) that have lymphoblasts with azurophilic cytoplasmic granules. These reports do not describe immunologic markers or cytogenetics. We report five additional cases with detailed cytologic, immunologic, and cytogenetic studies. At diagnosis one of these patients had central nervous system disease, while the others had no unusual features. Four of the five patients attained remission. The blasts of all five patients contained distinct cytoplasmic azurophilic granules. The granules were negative for peroxidase and chloroacetate esterase and positive for PAS, acid phosphatase, alpha-naphthyl acetate esterase incompletely fluoride inhibited, alpha-naphthyl butyrate esterase, and in one case, Sudan black B. In the one patient studied by electron microscopy, characteristic lymphoblasts contained membrane-bound electron lucent inclusions, which stained positively with non-specific esterase. Immunologic markers showed a common ALL phenotype. Different cytogenetic abnormalities were seen in all cases. It is important to recognize the characteristics of this morphologic subtype of ALL in order to avoid a misdiagnosis of acute nonlymphocytic leukemia.

Adolescent↗
PubMed1983

Altitude-related deaths in seven trekkers in the Himalayas.

The clinical features and necropsy findings are described for seven trekkers in the Himalayas whose deaths were related to high altitude. The fatal outcome was due to serious pulmonary and cerebral disease. Oedema of the lungs and brain was prominent but so was thrombosis and haemorrhage, features of acute mountain sickness that have received insufficient recognition in the past. Most of the men were middle aged. Some began their trekking soon after flying to high altitude before becoming acclimatised and some remained at high altitude or climbed even higher despite the development of vomiting, breathlessness, and exhaustion. In one case death occurred despite prompt recognition and treatment of symptoms by administration of oxygen and swift evacuation to low altitude.

Adult↗