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Biomedical subjects

R David

Publications and source records attributed to R David.

At least 163 records · Page 9Linked to original sources

Long-term ocular hypotensive effect of levobunolol: results of a one-year study.

Data for the first 12 months are reported for an ongoing, multicentre, clinical study comparing the long-term, ocular hypotensive efficacy and safety of topical levobunolol (0.5% and 1%) and timolol (0.5%). This study was a double-masked trial testing 88 patients with chronic open angle glaucoma or ocular hypertension. During the 12-month period drops were instilled twice daily into both eyes after a washout of prestudy ocular hypotensive medication. The effect of the three treatments in reducing intraocular pressure (IOP) was similar. Mean IOP reductions over the 12 months averaged 7.2 mmHg for the 0.5% levobunolol group, 6.2 mmHg for the 1% levobunolol group, and 6.0 mmHg for the timolol group. Decreases in mean heart rate of up to 5 beats per minute were observed in the 0.5% levobunolol group, up to 8 beats per minute in the 1% levobunolol group, and up to 4 beats per minute in the timolol group. Several patients were removed from the study owing to side effects possibly related to levobunolol treatment.

Adult↗

Clear cell chondrosarcoma.

The clinical, radiologic, and histopathologic features of three cases of clear cell chondrosarcoma are described. On radiographs, this rather benign-appearing tumor resembles a chondroblastoma when it occurs at the end of a long bone, and may occasionally show a calcified matrix. However, it has distinctive tumor cells with a centrally placed vesicular nucleus surrounded by clear cytoplasm. The lesion has a low-grade malignancy and is amenable to en bloc surgical resection, which results in a much better prognosis than that of conventional chondrosarcoma.

Adult↗

Epidemiology of acute angle-closure glaucoma: incidence and seasonal variations.

126 cases of acute angle-closure glaucoma were encountered in the total population of the Israel Negev region during 12 years. This constitutes an incidence of 4.2/100,000/year in the total population and 11.1/100,000 in the over-30 population. The female:male ratio was 2.1:1 and the most frequently affected age-group was the 51-60 one; when age adjustment was made for the total population, the risk was equally high for all ages above 50. The ethnic origin had no effect on the incidence. A statistically significant preponderance of attacks occurring during summer and winter was found.

Acute Disease↗

Studies on HSV specific IgA antibodies in lacrimal fluid from patients with herpes keratitis by solid phase radioimmunoassay.

A highly sensitive solid phase radioimmunoassay (RIA) was adapted for determination of herpes simplex virus (HSV) specific IgA antibodies in lacrimal fluids. The RIA procedure was applied to examine HSV IgA antibodies in serial samples of lacrimal fluid and in sera from 14 patients with herpes keratitis. HSV-specific IgA antibodies were detected in the lacrimal fluid of the affected eye in 12 of the 14 patients. HSV IgA antibodies were also detected in the lacrimal fluid of the unaffected eye of 7 of these patients in titers lower than those found in the corresponding affected eye. Evidence for local HSV antibody production in lacrimal fluid in herpes keratitis was supported by examination for antibodies to the unrelated measles antigen. Detection of lacrimal fluid HSV IgA antibodies might be a useful adjunct in rapid diagnosis of herpes keratitis. The advantage of characterizing the local immune response as well as viral expression in the affected vs. the unaffected eye in the same individual as a model for understanding the factors leading to subclinical vs. clinical manifestations of recurrent ocular herpes virus infections will be discussed.

Adolescent↗

Autologous bone marrow transplantation with marrow decontaminated by immunotoxin T 101 in the treatment of leukemia and lymphoma: first clinical observations.

Four patients with T-cell malignancies of poor prognosis (three with non-Hodgkin's lymphoma and one with acute lymphoblastic leukemia) received the following consolidation therapy for complete or partial remission: cyclophosphamide (120 mg/kg) plus total-body irradiation, followed by reinfusion of cryopreserved autologous marrow previously purged in vitro by immunotoxin T 101 (SR 41322). This immunotoxin is made of the murine monoclonal T 101 antibody coupled to chain A of ricin. The doses of immunotoxin used were 10(-9) and 10(-8) M, and the durations of incubation were 4 and 20 hours at 37 degrees C. Recovery of progenitors CFUc and BFUe was total following incubation with immunotoxin T 101, but diminished after cryopreservation (15%-80% for CFUc, 33%-47% for BFUe), suggesting an increased fragility of the incubated progenitors to freezing. In every case, hematopoietic recovery occurred within normal time periods, with a wbc count greater than 10(9)/L and a platelet count greater than 50 X 10(9)/L on Day 22 (range, 15-31) and Day 21 (range, 22-47), respectively, demonstrating the feasibility of autologous bone marrow transplantation with marrow pretreated by immunotoxin. However, the slow recovery of lymphocytes and the development of severe infections in two patients may indicate that an in-depth study of immunological reconstitution after in vitro treatment of the marrow with immunotoxin T 101 is necessary.

Adolescent↗

Intracerebral hemorrhage in the full-term neonatal infant.

Supratentorial intracerebral hemorrhage was diagnosed in 18 full-term neonates, including six with primarily intraparenchymal hemorrhage and 12 with primarily intraventricular hemorrhage. Precipitating or associated factors were hypoxic-ischemic injury in five patients, polycythemia in two, and cranial birth trauma in two. Nine other infants had no identifiable medical risk events. The pathogenesis of intraparenchymal hemorrhage was probably related to hemorrhagic infarction, but the pathogenesis of intraventricular hemorrhage was often unknown. All 17 survivors returned for neurologic and developmental examinations between 1 and 7 years of age. Follow-up assessments were normal in nine children and abnormal in eight. Two had perceptual difficulties, three had moderate-to-severe cognitive deficiencies (two of the three had hemiplegia), and three had severe mental and neurologic handicaps. Eight of nine children with known or suspected hypoxic-ischemic or traumatic insults suffered moderate-to-severe disabilities whereas eight of nine children with no known precipitating cause for their hemorrhage developed normally.

Apgar Score↗

Adult Wilms' tumor: clinical and radiographic features.

The clinical and radiographic features of Wilms' tumor in 4 adult patients are described. Wilms' tumors in adults are usually bulky and contain numerous areas of necrosis and hemorrhage, imparting a complex appearance to the lesion on sonography and computed tomography. Angiography reveals the tumor to be hypovascular with some neovascularity. No specific features of the lesion differentiate it from hypernephroma. In contrast to the childhood variety, Wilms' tumors in adults have ill-defined margins and frequently extend into the retroperitoneum. Their treatment is the subject of debate and prognosis is poor.

Adult↗

Autologous bone marrow transplantation in the treatment of poor prognosis non-Hodgkin's lymphomas.

Twelve patients with non-Hodgkin's lymphomas of poor prognosis were treated by TACC high-dose chemotherapy (cyclophosphamide 45 mg/kg/day X 4, cytosine arabinoside 200 mg/m2 i.v. q 12 hr X 7,6-thioguanin 100 mg/m2 p.o. X 7 and CCNU 200 or 250 mg/m2 p.o., single dose) followed by autologous bone marrow transplantation (ABMI) (infused dose: 853-20,000 CFU-c/kg). Patients were divided into 2 groups: those in primary therapy with high tumor load (group 1; 3 initial diagnoses, 3 relapses) and those in consolidation therapy for a low tumor load (group 2; 5 complete and 1 partial remissions). Results show that: (1) the aplasia following autologous bone marrow transplantation was short. Leukocyte (greater than 10(9)/1) and platelet (greater than 50 X 10(9)/1) recoveries were observed on day 12 (range, 9-19) and day 14 (range, 8-27). (2) In group 1 there were 3 complete remissions (8,21, 45+ months) and 3 failures, including 1 death to toxicity of TACC. The 3 remissions occurred in patients in primary therapy and overall survival of these patients from the time of initial diagnosis was 48+, 48+ and 60+ months. In group 2 there were 5 persisting complete remissions (12+ to 40+ months) and 1 failure. Overall survival of these patients was 23+, 24+, 27+, 42+ and 70+ months. In both groups failures were associated with contamination of the frozen marrow by tumor. The toxicity of the association TACC + ABMT was acceptable and dominated by the risk of pericardial effusion and infection. The latter was absent in group 2 and occurred in 5/6 cases in group 1. These preliminary results indicate that autologous bone marrow transplantation has a possible role in the aggressive treatment of non-Hodgkin's lymphomas of high-grade malignancy and that its use should preferentially be in the consolidation mode.

Antineoplastic Combined Chemotherapy Protocols↗

A diagnostic approach to suspected obstructive sleep apnea in children.

Most children with obstructive sleep apnea will benefit from tonsillectomy and adenoidectomy. Although polygraphic monitoring remains the definitive diagnostic technique, we wondered if all children suspected of having OSA require such evaluation. We therefore administered a standardized questionnaire to the parents of 23 children with polygraphically proved OSA related to adenotonsillar hypertrophy, 46 age- and sex-matched normal children, and 23 children subsequently referred because of possible OSA. Significantly increased frequencies of the following symptoms were found in the OSA group compared with the control group: difficulty breathing during sleep, 96% vs 2%; apnea observed by the parents, 78% vs 5%; snoring, 96% vs 9%; restless sleep, 78% vs 23%; chronic rhinorrhea, 61% vs 11%; and mouth breathing when awake, 87% vs 18%. Using discriminant analysis, an OSA score was derived that correctly classified all control subjects and 22 of 23 patients with OSA. Considering the data from all groups, we found that (1) OSA scores greater than 3.5 were highly predictive of OSA requiring adenotonsillectomy; (2) no child with an OSA score less than -1 had OSA; and (3) in children with OSA scores between -1 and 3.5, polygraphic monitoring was required to determine the severity of sleep-related airway obstruction and the need for surgical treatment. Use of the OSA score should decrease the need for polygraphic monitoring and facilitate selection of children for tonsillectomy and adenoidectomy.

Adenoids↗

Abnormalities of thyroid function in infants with Down syndrome.

We describe 12 of 1130 infants with Down syndrome in whom various degrees of thyroid dysfunction were detected by neonatal screening. These aberrations were confirmed subsequently in 11 patients. In eight of 11 children, persistent primary hypothyroidism, was diagnosed, whereas in the remaining three patients transient thyroid abnormalities were noted. The twelfth patient died and could not be retested. We found an incidence of persistent primary congenital hypothyroidism in infants with Down syndrome of 1:141, or about 28 times more than in the general population. The cause of thyroid aberrations in these infants remains unclear; none of the studied patients had agenesis or ectopia of the thyroid gland. On initial screening most infants with Down syndrome had only mild biochemical abnormalities, with gradual decompensation occurring thereafter. Infants with Down syndrome are therefore at high risk for congenital hypothyroidism and should have careful follow-up to prevent further deterioration of their mental development or growth.

Child, Preschool↗

Estimated prevalence of glaucomatous blindness in the Negev region of Israel.

An estimate of the prevalence of glaucomatous blindness in the Negev region of Israel was obtained by pooling two sources of available data: a state-run regional registry of blind people and the records of the glaucoma clinic of the Soroka Medical Centre, Beer Sheva. The denominator was the total population insured with the Kupat Holim (Sick Fund) of the Histadrut (General Federation of Labour). Glaucoma was the cause of blindness in only 10% of registered cases. Ninety-five individuals fulfilling the blindness criteria (3/60 or less, or a reduction of the visual field to 20 degrees or less in the better eye) were identified from both sources: this represents a total population prevalence of 39 per 100 000 population and 153 per 100 000 for those aged 41 and over. Glaucomatous blindness was more frequent in males than females, but the risk appeared to increase exponentially with age in both sexes. These data provide a previously lacking quantitative estimate of the prevalence of glaucomatous blindness in the Negev region.

Adult↗

A syndrome of gonadotropin resistance possibly due to a luteinizing hormone receptor defect.

An 18-yr-old 46,XY man with primary hypogonadism and a microphallus is described whose Leydig cells appear to be partially insensitive to gonadotropin action. The external genitalia were well differentiated though abnormally small. The mean +/- SE baseline plasma testosterone (T) level was 62 +/- 3.9 ng/dl, and androstenedione was 34.5 +/- 7.3 ng/dl. Plasma levels of dehydroepiandrosterone, dehydroepiandrosterone sulfate, 17-hydroxyprogesterone, 17-hydroxypregnenolone, corticosterone, deoxycorticosterone, and 17 beta-estradiol were all normal. After the im administration of hCG, plasma T increased insignificantly from 71 to 78 ng/dl, and androstenedione increased from 22 to 47 ng/dl; there was no significant change in the levels of precursor steroids. The mean +/- SE serum FSH level was 17.4 +/- 3.6 mIU/ml, and LH was 15.4 +/- 1.1 mIU/ml (normal, 5-20); both responded briskly to iv GnRH. Exogenous T therapy resulted in normal virilization, whereas therapy with hCG was ineffectual. Testicular biopsy revealed Leydig cells in normal numbers, some spermatogenesis, and thickened tubular basement membranes. In vitro binding studies using [125I]hCG were performed with testicular homogenates from the patient and three normal subjects. With 7.4 fmol labeled hCG, the specific binding (mean +/- SD), expressed as femtomoles of hCG per mg protein, was 1.16 +/- 0.44 compared to 2.49 +/- 0.41 in normal subjects (P less than 0.05). These data demonstrate partial resistance to hCG and suggest that the defect in Leydig cell function may be at the LH receptor or postreceptor level.

Adolescent↗