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Biomedical subjects

R A Williams

Publications and source records attributed to R A Williams.

At least 127 records · Page 7Linked to original sources
PubMed1990

Events precipitating psychiatric hospitalization of children.

The precipitating events that preceded the admission of 50 children to an inpatient psychiatric program were studies and defined. These events, while varying in their particulars, could be grouped into three broad conceptual categories: 1) emotionally related events; 2) severe-conduct events; and 3) school-related events. The emotionally related events were the most numerous: suicide threats or attempts preceded the admission of 22% of the sample. The study findings are discussed in terms of their developmental, treatment, and preventive significance and are compared with the findings obtained from a previous study with adolescent patients.

Child↗
PubMed1990

The effect of inpatient psychiatric hospitalization on weight gain in children and adolescents.

Measures of weight were obtained both at admission and at discharge for children and adolescents receiving inpatient services at a private psychiatric hospital. The sample included 20 males and 20 females from each of three units: child psychiatric, adolescent psychiatric, and adolescent substance abuse. The difference between the actual weight change of the subjects and the weight change predicted from growth charts was obtained. Overall, subjects gained a significant amount of weight. The actual mean increase in weight was roughly 3.5 times greater than the predicted increase, and there were no significant differences in weight gain between males and females among patients from each of the three units. Potential explanations for this increase in weight are explored, and the implications are discussed.

Adolescent↗
PubMed1990

Safety of operation in biliary pancreatitis during the same hospitalization.

Over the past 4 years, 61 patients with biliary pancreatitis were managed, 48 of whom had operation on the biliary tree within the same hospital admission. Initial therapy was medical and operation was performed at a median of 6 days from admission (range: 3-14 days). Two patients required surgery for non-resolution of the pancreatitis, but the other 44 patients had clinical and biochemical resolution prior to surgery. At operation, oedematous-interstitial pancreatitis was found in 18 patients, necrotizing pancreatitis in two and a normal pancreas in 28 patients. Common duct exploration in 15 patients resulted in 10 positive explorations. One death occurred in a patient with necrotizing pancreatitis and an impacted stone, but overall morbidity was low and total hospitalization in the operated group averaged 12 days. There was a statistically significant difference in the incidence of bile duct stones (five of 10 versus seven of 38, P = 0.019) and operative findings of pancreatitis (seven of 10 versus 11 of 38, P = 0.038) in patients having surgery before or after 4 days of hospitalization. Initial conservative management for 4 days allows resolution of pancreatitis in most patients, minimizing the need for and potential risk from common duct exploration.

Acute Disease↗
PubMed1990

The experience of a child and adolescent inpatient unit in London.

The Mildred Creak Unit of the Hospital for Sick Children, Great Ormond Street, London, England, has been evaluating and treating children and adolescents now for over 16 years. A portion of their valuable experience, with 394 patients reviewed, is presented in this article. Items discussed include: (1) major diagnostic labels utilized and their frequency of use; (2) ages and sex of young people within the major diagnostic categories; and (3) information on discharge status plus average length of stay. This paper affords the reader an opportunity to compare the Mildred Creak Unit experience with his or her own experience, hopefully enhancing further international sharing of child and adolescent data.

Adolescent↗
PubMed1990

The clinical significance of fluid collections in acute pancreatitis.

Computed tomography (CT) displays fluid collections in patients with acute pancreatitis as well defined intra- or extrapancreatic homogeneous areas with low attenuation numbers. We followed, prospectively, the clinical courses of 128 patients who had CT during an episode of acute pancreatitis, to determine the natural history and clinical significance of any fluid collections that developed. Fluid collections were found in 48 (37%) of the 128 patients with pancreatitis. Thirty-eight developed in the 86 (44%) patients with alcoholic pancreatitis, five in the 33 (15%) with biliary pancreatitis and five in the nine (55%) with other causes of pancreatitis (excluding chronic pancreatitis, trauma, or malignancy). On clinical follow-up of the 48 patients with fluid collections, 21 patients required operation; two died before an operation was done and 25 did not require operation. Operations were done to treat pseudocysts (14), abscess (5), and necrosis (3). One patient had an operation for a pseudocyst and an abscess. All 14 patients requiring operation for pseudocyst had collections greater than 7 cm and 13 of these patients had alcoholic pancreatitis. Of the 25 patients not requiring operation, five were lost to follow-up, and 19 of the 20 who had spontaneous resolution of their fluid collection(s) had collections less than 6 cm in diameter. The eight patients who required operative pancreatic debridement for abscess or necrosis had multiple small fluid collections. In summary, fluid collections were found in one-third of patients with acute pancreatitis and were often associated with the development of local complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Abscess↗
PubMed1989

Non-aqueous size-exclusion chromatography coupled on-line to reversed-phase high-performance liquid chromatography. Interface development and applications to the analysis of low-molecular-weight contaminants and additives in foods.

An interface has been developed which permits the on-line coupling of size-exclusion chromatography in tetrahydrofuran with aqueous reversed-phase high-performance liquid chromatography. The interface isolates the required size exclusion chromatography fraction and dilutes it with water to ensure reconcentration of analytes on the reversed-phase column prior to gradient elution. Operational parameters and the influence of analyte polarity have been examined in detail. A predictive system is presented for determining the applicability of the system to any analyte, based on solute retention times on an ODS phase eluted with a methanol-water gradient. The method is illustrated with examples of direct analyses of crude lipid extracts from a snack product for 2,6-di-tert.-4-methylphenol and from chocolate for dibutyl phthalate. Detection limits of ca. 0.5 mg/kg have been achieved.

Chromatography, Gel↗
PubMed1989

Transfusion of infants with activation of erythrocyte T antigen.

A protocol for transfusion of infants with erythrocyte T-antigen activation was evaluated for safety and effectiveness in a prospective, 3-year, sequential series of 1672 infants admitted for intensive care. Erythrocyte T antigens are activated by enzymes produced by clostridia or other bacteria in infants with sepsis, often in association with necrotizing enterocolitis. Transfusion of these infants with blood products containing plasma carries the risk of causing intravascular hemolysis. Our transfusion protocol included testing for T-antigen activation, restricting transfusion of patients with activated T antigens to washed erythrocytes or washed platelets whenever possible, and selecting donors with low-titer anti-T when plasma-containing blood products were required. In this series, 10 patients had T-antigen activation, including four with clostridial infections. Severe hemolysis occurred in one patient who received plasma before T-antigen activation developed. Of five patients who received low-titer anti-T plasma, mild hemolysis occurred in three and no hemolysis in two. Four patients who received no plasma-containing blood products experienced no hemolysis. Used cautiously, this protocol allows a full range of transfusion therapy to infants with T-antigen activation.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1989

Risk factors for emotional/behavioral problems in young adolescents: a prospective analysis of adolescent and parental stress and symptoms.

Stressful events in the lives of 309 10- to 15-year-olds and stressful events and psychological symptoms reported by their parents were examined in a 9-month study. Ss' self-reported emotional/behavioral problems were predicted by their reports of stressful events and their fathers' reports of psychological symptoms in cross-sectional analyses. Analyses at follow-up after controlling for initial reports of emotional/behavioral problems and prospective analyses predicting from first assessment to follow-up yielded significant effects for Ss' self-reported stressful events. Mothers' reports of children's problems were predicted by mothers' psychological symptoms in cross-sectional analyses and at follow-up after controlling for initial emotional/behavioral problems. Only prior levels of maternal reports of emotional/behavioral problems predicted mothers' reports of their children's problems 9 months later.

Adolescent↗
PubMed1989

Acquired immune deficiency syndrome (AIDS). Indications for abdominal surgery, pathology, and outcome.

Thirty-six major abdominal operations were performed on 35 Acquired Immune Deficiency Syndrome (AIDS) patients (33 men, two women). Twenty-two elective operations were indicated for diagnosis of abdominal or retroperitoneal mass (6), incomplete bowel obstruction (5), intra-abdominal infection (4), biliary symptoms (3), thrombocytopenia (3), and toxic megacolon (1). Fourteen emergency operations were for perforated viscus or peritonitis (11), massive gastrointestinal bleeding (2), and cecal volvulus (1). In 5 of 22 (23%) elective operations AIDS was unknown to the treating physicians until diagnosed by the surgical pathology; in contrast, all 14 emergency operations were in patients who had a known diagnosis of AIDS. The operative findings were related to AIDS in 34 of 36 (94%) operations. Cytomegalovirus was the most common pathogen, isolated or identified microscopically in 11 patients (eight emergency and three elective operations). Mycobacterial infections presented as retroperitoneal adenopathy or splenic abscess in six patients. Non-Hodgkins lymphoma was the most common malignancy found, presenting as an abdominal mass (4), bowel obstruction (3), or with gastrointestinal bleeding (2). Kaposi's sarcoma was diagnosed at laparotomy in four patients. The 1-month operative mortality rate for elective operation was 9% (2 of 22) and 46% (6 of 13) in emergencies. Postoperative complications included 1 reoperation for sepsis caused by inadequately resected CMV colitis; 1 pancreatic fistula; 1 wound dehiscence, and 2 minor wound infections.

Abdomen↗
PubMed1989

Events precipitating hospital treatment of adolescent drug abusers.

Recognition of and response to child and teenage drug abuse is poor. It seems that behavioral crises are necessary to bring a child and family to treatment, often after an extensive history of drug abuse. This study examines the events that occur immediately before hospitalization and lead to admission. Clusters of precipitating factors and psychosocial problems appear to accompany the use of alcohol and drugs. Recognition of these predictable behavior patterns (syndromes) may prove a more sensitive index of drug involvement than direct signs or sequalae of intoxication.

Acting Out↗
PubMed1989

Iron deficiency reduces cytochrome concentrations of mitochondria isolated from hamster cheek pouch epithelium.

The effects of iron deficiency on the aerobic pathway of energy metabolism were studied using mitochondria isolated from epithelial cells from the hamster cheek pouch. A statistically significant reduction in the concentrations of cytochromes aa3, b and c (P less than 0.05), a reduction (P = 0.064) in cytochrome cl and altered cytochrome ratios were found in the mitochondria of iron deficient compared to normal animals. State 4 respiration was demonstrated in the mitochondria of both normal and iron deficient animals but state 3 respiration could not be demonstrated; this suggests uncoupling of oxidative phosphorylation which may be an artefact associated with the separation of epithelium from its connective tissue. Nevertheless we conclude that the reduction in cytochrome concentration is a real effect of iron deficiency which may explain, at least in part, the reduction of both energy production and cell proliferation seen in oral epithelia under these conditions.

Animals↗
PubMed1989

Assessment of ST segment depression in patients with cardiac disease after local anesthesia.

This study found that dental treatment with 2% lidocaine with 1:100,000 epinephrine did not provoke myocardial ischemia, as assessed by greater than or equal to 1 mm of ST segment depression. Although in some cases systolic and diastolic blood pressure and rate pressure product increased slightly after local anesthetic administration, these changes were not statistically significant. Because these patients were medically supervised and compliant with cardiac therapy, this study suggests that such patients are not at great risk while receiving local anesthesia with 1:100,000 epinephrine for routine dental care.

Aged↗
PubMed1989

Qinghaosu-mediated oxidation in normal and abnormal erythrocytes.

Qinghaosu, a potent antimalarial agent, has recently been shown to act via oxidative mechanisms. Hence, we have investigated what effect qinghaosu has on cellular oxidation in normal and oxidant-sensitive red blood cells (RBCs). At 500 mumol/L, qinghaosu was found to directly alter red cell deformability (DI) in both normal (hemoglobin AA) and abnormal (hemoglobins SS, AE, and EE) RBCs, with the maximum DI being 70% to 80% of that of untreated RBCs. Although concentrations of less than or equal to 200 mumol/L qinghaosu had a minimal effect on the maximum DI, qinghaosu was found to act as an efficient prooxidant at these concentrations. Cellular deformability was lost more rapidly in response to exogenous oxidants in the qinghaosu-treated RBCs than in control cells. Hemoglobin SS and EE RBCs pretreated with qinghaosu demonstrated a much more rapid decrease in cellular deformability than did the control RBCs in response to exogenous oxidants. Additionally, qinghaosu resulted in a dose-dependent increase in red cell lysis and methemoglobin generation while decreasing reduced glutathione concentration. As a consequence of qinghaosu challenge, a decrease in unsaturated fatty acids was noted. Deoxyqinghaosu, which lacks the endoperoxide bridge and is pharmacologically inactive, did not affect cellular deformability and did not function as a prooxidant. Additionally, deoxyqinghaosu had no effect on fatty acid composition, red cell lysis, methemoglobin generation, or reduced glutathione concentration. In conclusion, although the oxidative effects of qinghaosu on uninfected erythrocytes were only seen at concentrations much greater than that necessary for antimalarial activity, these results confirm the proposition that qinghaosu may act via oxidative mechanisms. Furthermore, qinghaosu-mediated oxidation was significantly increased in erythrocytes characterized by enhanced oxidant sensitivity caused by unstable hemoglobins.

Artemisinins↗
PubMed1988

Operant measurements of contrast sensitivity in infant macaque monkeys during normal development.

The development of contrast sensitivity was measured longitudinally in seven Macaca nemestrina monkeys. Operant conditioning methods were used to train and then test infant monkeys from the ages of 1 to 12 months. Several changes were observed in the contrast sensitivity function, including an overall increase in sensitivity to contrast, a shift in the peak of the function toward higher spatial frequencies, and an increase in the cutoff spatial frequency. The time-courses for the changes in the contrast sensitivity function were characterized by rapid development during the first 10-20 weeks, followed by a gradual asymptotic development to adult levels over the remainder of the year. Sensitivity to contrast was found to develop with different time-courses for different spatial frequencies; sensitivity to low spatial frequencies reached adult levels much earlier than sensitivity to high spatial frequencies.

Aging↗