PubMed Health⌕ Search

Biomedical subjects

D R Powars

Publications and source records attributed to D R Powars.

51 records · Page 3Linked to original sources
PubMed1980

Lack of influence of fetal hemoglobin levels or erythrocyte indices on the severity of sickle cell anemia.

Persons with sickle cell anemia who have elevated fetal hemoglobin or lowered erythrocyte mean corpuscular volume are reputed to have less severe clinical manifestations and a greater probability of survival. This study examines the relationship between seven clinical indicators of morbidity in sickle cell anemia and seven hematological parameters that were collected from 214 patients. Risks of sickle cell crisis, acute chest syndrome, hospital admissions, cerebrovascular accident, aseptic necrosis, meningitis/septicemia, and death were used as indicators of morbidity. The hematological parameters included percent fetal hemoglobin, absolute fetal hemoglobin, percent hemoglobin A2, hemoglobin concentration, packed cell volume, mean corpuscular volume, and mean corpuscular hemoglobin concentration. Statistical analyses of the data showed no relationship between the hematological parameters and six of the seven clinical indicators of the severity of sickle cell anemia. The only significant finding was an increased risk of stroke in those patients with lower levels of fetal hemoglobin. Therefore, with this exception, there is no predictable relationship between morbidity and mortality in sickle cell anemia and levels of fetal hemoglobin or erythrocyte indices. Thus, the general belief that there is an association between severity of sickle cell anemia and the levels of fetal hemoglobin has not been established.

Adolescent↗
PubMed1978

Neutropenia associated with chrysotherapy for juvenile rheumatoid arthritis.

Severe neutropenia, in the absence of generalized bone marrow depression, is a rare complication in adults receiving chrysotherapy for rheumatoid arthritis and has not been described in children. Isolated, severe neutropenia developed in five children with systemic onset JRA while they were receiving gold injections. This potentially fatal complication occurred within eight weeks of beginning therapy in four patients, and after 24 weeks of well-tolerated therapy in the fifth. Leukopenia preceded neutropenia in two children. Localized infection was successfully treated in one child; septicemia was fatal to a second child. Neutropenia resolved within eight to 14 days of its onset in the four survivors; chelation with dimercaprol in one child did not appear to alter the recovery time. It is suggested that a systemic onset of JRA in children less than 6 years of age identifies a higher risk group developing severe neutropenia during chrysotherapy. Cessation of gold therapy upon recognition of a decreasing neutrophil count may prevent or ameliorate a developing neutropenia; careful observation for, and early treatment of, infection may alter its outcome.

Agranulocytosis↗
PubMed1978

Staging laparotomy and splenectomy for Hodgkin's disease.

The major objective of diagnostic laparotomy in Hodgkin's disease is to define the extent of involvement not detectable by nonoperative means. Fifty patients in this institution had operative staging procedures; six for recurrent disease three to 11 years after initial therapy. Twenty-four patients had nodular sclerosis, 23 mixed cellularity, and three had other types. The clinical stages were advanced in 13 patients and decreased in seven patients. Two patients (both had mixed cellularity and systemic symptoms) had positive wedge biopsy of the liver, whereas direct needle biopsy was negative. Nineteen spleens contained Hodgkin's disease but only three could be palpated on physical examination. About half the patients with abnormal lymphangiograms had positive periaortic nodes; lymphangiogram had a false negative rate of 12%. Additional procedures performed included appendectomy, oophoropexy, and resection of Meckel's diverticulum. There was no mortality and only one case had severe postoperative Salmonella septicemia. Our findings are comparable with those reported in the literature.

Adolescent↗
PubMed1977

Staging laparotomy for Hodgkin's disease in children. Evaluation of the technique.

The evaluation of a technique of laparotomy for the staging of Hodgkin's disease in childhood, including 52 operative procedures, is reviewed. A standard protocol, including splenectomy, multiple hepatic and bone marrow biopsies, and the routine sampling of at least six designated lymph node groups, was employed. It was demonstrated that the surgeon is unable to identify Hodgkin's disease by gross inspection and that the biopsy of node groups previously not included in routine laparotomy studies, ie, mesenteric and porta hepatis nodes is essential to staging in childhood. Stage was altered from stages I and II to stages III and IV in 35% of the patients. The incidence of abdominal recurrence following a negative laparotomy was 7%, and the incidence of post-splenectomy hyperacute infection was 4.5%. This study included minimal use of the lymphangiogram (33%), which accounted for the relatively larger group of patients in clinical stages I and II.

Biopsy↗
PubMed1977

Leukemia following Reye's syndrome treated with exchange transfusions: search for type-C viral infection.

A 5-year-old child developed acute lymphoblastic leukemia during convalescence from an episode of Reye's syndrome that was treated with multiple exchange transfusions. Routine laboratory, histology, and viral serology were unable to establish a common etiology for the 2 illnesses. Cultural and immunologic methods to search for evidence of infection with type-C viruses or viral genes in lymphoblasts from the buffy coat and bone marrow failed to reveal these agents. Although no common infectious etiology was defined for the close temporal occurrence of 2 rare diseases, the possibility of an iatrogenically induced malignancy was considered.

Blood Transfusion↗
PubMed1977

Frequency analysis of the EEG in children with sickle cell disease.

An automated technique for EEG frequency analysis was employed in the study of nine children with sickle cell disease. Quotients, Q(1) (delta+theta/alpha+beta) and Q(2) (theta/alpha+8), were calculated from the computed power in each frequency range. Recordings from occipital-parietal and temporal-frontal areas resulted in a higher Q(1) for sickle cell disease patients than for reported normals (p<.002 and p<.05 respectively). Q(2) value from the occipital-parietal sites were also higher for the sickle cell group (p<.05).The technique reported here lends itself to serial studies in appropriate patient groups and suggests the possibility of an organic basis for some of the results found.

Adolescent↗
PubMedDate not supplied

Peripheral neuropathy in lead-intoxicated sickle cell patients.

Peripheral neuropathy and hypertension caused by lead intoxication are reported in two children with sickle cell anemia. One child had generalized weakness in the initial occurrence and distal paralysis during a relapse two years later. The second child had foot and wrist drop. Both had slow peripheral nerve conduction velocities during the episodes. Chelation therapy was successful and resulted in a return of strength (over a period of several months) and a normalization of the blood pressures. Children with sickle cell anemia who are subjected to lead intoxication appear to be predisposed to peripheral nerve damage.

Anemia, Sickle Cell↗
PubMedDate not supplied

The selective suppression of immunogenicity by hyaluronic acid.

A hyaluronidase-sensitive component of human peritoneal fluid from a patient with Wilms' tumor when injected into rabbits has been shown to suppress the formation of humoral precipitating antibodies to certain major classes of proteins present in the fluid. Furthermore, it has been found that hyaluronic acid, when included with certain test antigens (serum albumin, fetuin) or antigen mixtures (tumor isolates or mixtures of albumin, immunoglobulin G and immunoglobulin M), produces a marked distortion or complete blockage of immunoelectrophoresis precipitin arcs, as well as altered gel chromatography elution profiles. These findings that hyaluronic acid can interfere profoundly with both the elicitation of a complete antibody response and the formation of "normal" patterns of antigen-antibody precipitates in laboratory tests supports the possibility that this polysaccharide may play an immuno-regulatory role by masking potential immunogens. Consideration of the mechanisms for these in vivo and in vitro effects suggests that there may be some common basis in an "excluded volume" property of the hyaluronate, but this does not appear sufficient to explain the complexity and selectivity of the observed phenomena.

Animals↗