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Biomedical subjects

M D Williams

Publications and source records attributed to M D Williams.

At least 109 records · Page 6Linked to original sources
PubMed1991

Cardiopulmonary bypass, profound hypothermia, and circulatory arrest for neurosurgery.

Six female and 4 male patients (age, 23 to 75 years) underwent operation for difficult intracranial lesions. Preoperative diagnoses included four giant intracranial aneurysms, three base of skull glomus jugulare tumors, two arteriovenous malformations, and one cerebellar hemangioblastoma. All lesions were inoperable or nearly so by standard neurosurgical techniques. All patients were placed on total bypass via groin cannulations. Bypass times ranged from 111 to 269 minutes (mean, 174 minutes) with cooling times of 26 to 83 minutes (mean, 48 minutes) and warming times of 68 to 110 minutes (mean, 83 minutes). Circulatory arrest times ranged from 1.25 to 60 minutes with 1 patient not requiring arrest. The lowest core temperatures recorded varied from 8.4 degrees to 13.7 degrees C. There was one postoperative death and one major complication, both in patients with arteriovenous malformations. Eight patients (80%) have achieved an excellent result. Profound hypothermia with the option of circulatory arrest and exsanguination has been an indispensable adjunct to the safe management of intracranial aneurysm, glomus jugulare tumor, and hemangioblastoma.

Adult↗
PubMed1991

Complications in the use of compression plates in the treatment of mandibular fractures.

The use of internal rigid fixation with plates in the treatment of facial fractures continues to increase in popularity. The principal advantage is in avoiding the use of maxillary mandibular fixation (intermaxillary fixation), thus enabling early return of function. However, there are clear guidelines for their use and technique of placement. A case is reported that demonstrates several avoidable complications in the use of compression plates and outlines the principles for the correct use of bone plates in mandibular fractures.

Adult↗
PubMed1991

Pilomatrixoma: a rare condition in the differential diagnosis of a parotid swelling.

Pilomatrixoma is an uncommon tumour arising from hair follicles. It is more common in the hair bearing areas of the upper region of the body, but is relatively rare. A case is presented in which clinical examination, ultrasound and computed tomography suggested the presence of a pleomorphic adenoma arising from the superficial lobe of the parotid gland, but at operation the mass was found to be separate from it and subsequent histological examination revealed a pilomatrixoma.

Adenoma, Pleomorphic↗
PubMed1991

Consistently normal CD4+, CD8+ levels in haemophilic boys only treated with a virally safe factor VIII concentrate (BPL 8Y)

Prospective biochemical, virological and selected immunological follow up has been done for up to 32 months on 15 previously untreated haemophilic boys following treatment with an intermediate purity dry heated factor VIII concentrate (BPL 8Y). Tests for liver function and antibodies to blood-borne viruses have been assessed monthly for the first year after starting treatment and thereafter every 2 months. All patients were immunized against hepatitis B and have not developed hepatitis B core antibodies and no boy has shown any rise in alanine transaminase level nor has anyone developed antibodies to hepatitis C (HCV). All patients have remained anti-HIV seronegative. T lymphocyte subsets have been measured approximately every 4 months and in no patient has there been a significant rise in CD8+ cells; one patient showed a significant decrease in CD4+ cells but these and all CD4+ values for the other boys remained within normal age related limits. Changes in CD4+ levels in this one boy were not related to the total amount of treatment received. This group of patients who appear not to have contracted HIV, hepatitis B or non A non B hepatitis following treatment with this intermediate purity factor VIII concentrate have also not shown any consistent changes in CD4+ or CD8+ cells, which have been recorded previously in frequently treated haemophiliacs.

Aging↗
PubMed1991

Pleomorphic adenoma of the parotid gland.

A case of pleomorphic adenoma arising from the deep lobe of the parotid gland is presented. Controversy often surrounds the management of a parotid lump, and many investigations are of little help. The first operation cures most salivary tumours and the patient usually has no residual disability. There is no place for the use of radiotherapy, in the treatment of pleomorphic adenoma.

Adenoma, Pleomorphic↗
PubMed1990

Serological evidence that dry heating of clotting factor concentrates prevents transmission of non-A, non-B hepatitis.

A new test for antibodies specific for an agent causing non-A, non-B hepatitis (NANBH) was used to screen 45 children with coagulation disorders who received factor concentrates. It was found that the test results correlated with clinical evidence of NANBH and that heat treatment of concentrates (80 degrees C for 72 hours) appears to have prevented transmission of NANBH.

Child↗
PubMed1990

Trend toward nonoperative management of splenic injuries.

Treatment of splenic injuries has evolved over the past decade to reflect more effort to conserve function of the spleen. Records of 169 patients admitted over a 6-year period were identified as documenting the treatment of splenic injuries. We collected data regarding patient age, gender, degree of hemodynamic stability, number of units of blood required, severity of splenic injury, Injury Severity Score, and results of treatment. There were 143 adults (age greater than 16 years) and 26 pediatric patients (age less than 17 years), with mean age in the 2 groups of 31.6 and 11.4 years, respectively. Males comprised 72% of the group, and blunt injury occurred in 154 of the 169 patients. In the adults, splenectomy, splenorrhaphy, laparotomy without operative treatment of the spleen, and nonoperative management were observed 48%, 30%, 14%, and 8% of the time and in the pediatric group 31%, 27%, 19%, and 23% of the time, respectively. By using operative splenic repair techniques and increased use of nonoperative management, the splenic salvage rate has increased in the last 6 years from 41% to 61% without an increase in morbidity and mortality. Incidence of spleen salvage correlated with severity of spleen and overall injury and cardiovascular stability.

Adult↗
PubMed1990

Clinical and laboratory evaluation of the treatment of von Willebrand's disease patients with heat-treated factor VIII concentrate (BPL 8Y).

Adequate rises of vWF:activity and satisfactory haemostasis have been obtained in six von Willebrand patients treated with heated 8Y factor VIII concentrate, despite multimeric analysis showing the concentrate to have an alteration in the proportions of the different vWF:Ag multimers including slight loss of the highest molecular weight multimers and an abnormal triplet. As heat-treated concentrates reduce the risk of transmitting blood borne viruses 8Y concentrate should be considered as a possible first line treatment of vWD patients in the U.K. if they do not have mild forms of type I von Willebrand's disease which can be treated with desmopressin (DDAVP) infusions.

Adolescent↗
PubMed1990

Transmission of human parvovirus B19 by coagulation factor concentrates.

The prevalence of antibody to human parvovirus B19 was determined in 86 children with congenital bleeding disorders. Forty-seven of 53 boys (89%) receiving non-heat-treated factor VIII or prothrombin complex concentrates were anti-B19 IgG positive compared with 38% of their age-matched controls and 48% of children treated with cryoprecipitate. Acute B19 virus infection occurred in 2 boys 3-4 weeks after they had received the same batch of commercial factor VIII concentrate. Of 11 susceptible children who had only received heat-treated National Health Service factor VIII concentrate (8Y), 1 acquired anti-B19 IgG. This suggests that 8Y heat-treated concentrate has a much reduced risk of transmitting B19 virus and, by implication, other less heat-stable viruses such as human immunodeficiency virus.

Adolescent↗
PubMed1989

Early treatment of Campylobacter jejuni enteritis.

The bacteriologic and clinical effects of early antibiotic treatment of Campylobacter jejuni enteritis were studied. Erythromycin rapidly eliminated C. jejuni from stools, whereas trimethoprim-sulfamethoxazole did not. Despite its bacteriologic effectiveness, erythromycin did not reduce the duration or severity of diarrhea, abdominal pain, or other symptoms.

Adult↗
PubMed1988

A prospective study of HIV-infected haemophilic boys and the prognostic significance of immune and haematological abnormalities.

Fifty-seven haemophilic boys have been studied prospectively determining T lymphocyte subsets and haematological parameters over a period of 26 months. Clinical follow up of these patients has continued for a further 41 months. At the beginning of the study 21 boys were HIV antibody seropositive and seroconversion was documented in a further 9 during the study period, giving a 52.6% incidence of HIV seropositivity. It has been possible to define a group of patients with persistently falling T4 values and these have shown clinical evidence of HIV infection. Although persistent generalized lymphadenopathy has been observed in 30% of HIV antibody positive boys and some boys have had unexplained fevers, only one boy has progressed to have the acquired immune deficiency syndrome (AIDS) some 5 years and 3 months from HIV seroconversion. This boy had a persistently falling T4 value. The importance of these findings is discussed. To date the abnormalities found in these haemophilic boys irrespective of their age are similar to those already reported in adult haemophiliacs.

Adolescent↗
PubMed1988

Change in immune response to hepatitis B in boys with haemophilia.

Eleven of 27 haemophilic boys who received a common batch of Factor VIII concentrate subsequently developed acute hepatitis B; although 9 were considered not to have been previously exposed to the virus, 2 other boys had been considered immune to hepatitis B. The amount of concentrate received by each child, together with their HIV-antibody status and T-lymphocyte subset distribution prior to exposure, did not influence their response to the hepatitis B virus (HBV). The two previously immune children who became infected, however, had evidence of the HIV-associated persistent generalized lymphadenopathy syndrome. Detailed investigation of the suspect batch of concentrate revealed hepatitis B surface antibody to a titre of 112 miu/ml, but surface antigen was not detectable, even after dissociation of antigen and antibody. As a result of this outbreak, 5 of the 11 boys remain carriers of the virus and 2 other family members have contracted acute hepatitis B. The possibility that the response of the haemophiliacs to HBV may be altered due to acquired alteration of their immune function is discussed. Regular screening of haemophiliacs, including those immune to hepatitis B, is recommended, since even with regular donor screening, HBV remains a major infective risk to haemophiliacs receiving Factor VIII replacement therapy, and the risk to an individual may change with time.

Carrier State↗
PubMed1987

The variable anteroposterior position of the retroperitoneal colon to the kidneys.

Five hundred supine abdominal CT scans were reviewed retrospectively to determine the variation of colonic position about each kidney. The anteroposterior position of the retroperitoneal colon was evaluated for different age groups and sexes at the level of the upper-, mid-, and lower-renal poles. The ascending/descending colon generally assumed a more posterior position about the lower poles and left kidney vs. the upper poles and right kidney. There were few significant differences between the sexes and among different age groups with two exceptions. In middle-aged and older women, the descending colon lay more lateral to the left lower kidney than in their male counterparts. Second, although the colon was located behind the kidney (retrorenal colon), in a nearly equal number of men and women, most patients with this colonic position were 60 years of age or older and had it about their lower renal poles. The overall frequency of retrorenal colon in the supine patient was 1.9%.

Adolescent↗
PubMed1986

Interactions of antirheumatic drugs with the superoxide generation system of activated human polymorphonuclear leukocytes.

The effects of antirheumatic drugs on superoxide anion (O2-.) production by human polymorphonuclear leukocytes (PMNL) activated in vitro with phorbol myristate acetate (PMA) or N-formyl-methionyl-leucyl-phenylalanine (fMLP) were investigated. Chloroquine (CLQ), auranofin (AF) and chlorotriethylphosphine gold (CTEP-G) at 10(-6) to 10(-4) M inhibited PMA and fMLP induced O2-. production in a dose dependent fashion. These drugs had no effect on O2-. production by the hypoxanthine/xanthine oxidase system, indicating that their inhibitory effects were directed at the O2-. generating mechanism and that they were not scavengers of the O2-. formed. AF and CTEP-G inhibited the specific binding of 3H fMPL to PMNL membrane receptors, whereas CLQ had no effect. Colchicine (COL) and gold sodium thiomalate (GSTM) on the other hand did not significantly affect PMA and fMLP induced O2-. production or the specific binding of the ligands to PMNL. The antirheumatic drugs had no effect on isolated neutrophil membrane protease, a chymotrypsin-like enzyme that has been implicated in the activation of NAD(P)H oxidase. However, several of the drugs inhibited the enzymatic activity of a subcellular preparation of PMNL NAD(P)H oxidase, the order of potency being GSTM greater than CLQ greater than penicillamine greater than COL greater than AF approximately equal to CTEP-G. The isolated NAD(P)H oxidase was also inhibited by the thiol compounds--thiomalic acid and dithiothreitol, suggesting that the mechanism of inhibition may involve sulfhydryl-disulfide interchange reactions.

Anti-Inflammatory Agents↗