Biomedical subjects
Publications and source records attributed to B Porter.
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A cohort of 199 individuals with mental retardation referred for behavioral and psychiatric crisis intervention services was studied to determine attributes differentiating physically aggressive behavior from other behavioral problems. Individuals with aggressive and nonaggressive behavior had similar neurological histories and current medical status and similar levels of seizure disorders and CNS abnormalities. Aggressive individuals more often had psychiatric diagnoses of organic brain syndrome, but frequencies of this diagnosis in each group were small. Current aggression was predicted by gender, level of mental retardation, and history of previous institutional placement; the strongest predictor was history of aggression. These data suggest a complex equation to describe social inadequacy involving interactions between CNS functioning and developmental cognitive and social variables that are only partially defined at this time. Further work to characterize this interaction almost certainly must include a prospective longitudinal analysis of social and developmental functions early in life.
BACKGROUND: Radiolabeled monoclonal antibodies recognizing B-lymphocyte surface antigens represent a potentially effective new therapy for lymphomas. We assessed the biodistribution, toxicity, and efficacy of anti-CD20 (B1 and 1F5) and anti-CD37 (MB-1) antibodies labeled with iodine-131 in 43 patients with B-cell lymphoma in relapse. METHODS: Sequential biodistribution studies were performed with escalating doses of antibody (0.5, 2.5, and 10 mg per kilogram of body weight) trace-labeled with 5 to 10 mCi of 131I. The doses of radiation absorbed by tumors and normal organs were estimated by serial gamma-camera imaging and tumor biopsies. Patients whose tumors were estimated to receive greater doses of radiation than the liver, lungs, or kidneys (i.e., patients with a favorable biodistribution) were eligible for therapeutic infusion of 131I-labeled antibodies according to a phase 1 dose-escalation protocol. RESULTS: Twenty-four patients had a favorable biodistribution, and 19 received therapeutic infusions of 234 to 777 mCi of 131I-labeled antibodies (58 to 1168 mg) followed by autologous marrow reinfusion, resulting in complete remission in 16, a partial response in 2, and a minor response (25 to 50 percent regression of tumor) in 1. Nine patients have remained in continuous complete remission for 3 to 53 months. Toxic effects included myelosuppression, nausea, infections, and two episodes of cardiopulmonary toxicity, and were moderate in patients treated with doses of 131I-labeled antibodies that delivered less than 27.25 Gy to normal organs. CONCLUSIONS: High-dose radioimmunotherapy with 131I-labeled antibodies is associated with a high response rate in patients with B-cell lymphoma in whom antibody biodistribution is favorable.
Rett syndrome was described relatively recently. It affects only females and is characterized by progressive deterioration of neurological status and impairment of psychomotor development. Psychomotor development is normal in the first year of life, but then there is deterioration of fine motor and language skills and later still, of gross motor skills. This results in severe motor function handicap and dementia. The arrested head growth, severe psychomotor retardation and typical "washing hands" movements are typical of Rett syndrome. We describe a 3-year-old Bedouin girl with the clinical picture of the syndrome and review the world literature, stressing the difficulty in detection and diagnosis.
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Infantile neuroaxonal dystrophy is a degenerative disease, mostly of nerve endings in the central and peripheral nervous system, with typical pathological findings. We describe a 3-year-old boy who had suffered from nystagmus, progressive muscle weakness and dementia since the age of 10 months. Biochemical work-up, MRI of the brain, and electrophysiological studies were within normal limits. Only skin biopsy, and sural nerve biopsy at a later stage, were diagnostic. We stress the importance of performing tissue biopsy even when intensive investigation is negative.
The design and synthesis of potent and selective neurokinin NK-2 receptor agonists 12 (GR64349) and 31 are described, together with structure-activity relationships for related analogues. Compound 12 (EC50 = 3.7 nM at NK-2 receptors in the rat colon; selectivity > 1000- and > 300-fold with respect to NK-1 and NK-3 receptors, respectively) was derived by incorporation of a Gly-Leu gamma-lactam conformational constraint into the C-terminal region of the neurokinin A octapeptide analogue [Lys3]-NKA(3-10). Compound 31 (EC50 = 15 nM in rat colon) contains a novel fused-bicyclic constraint at the corresponding site in the substance P hexapeptide analogue [Ava6]-SP(6-11).
Incorporation of D-Pro9 into substance P related peptides is known to enhance neurokinin NK-2 receptor agonist potency and selectivity with respect to other neurokinin receptors. We now report that replacement of D-Trp9 by D-Pro9 in the nonselective neurokinin antagonist [Arg5,D-Trp7,9, Nle11]-SP(5-11) gave a partial agonist with NK-2 receptor selectivity. Further incorporation of Pro10 provided the weak but selective NK-2 antagonist Arg-Ala-D-Trp-Phe-D-Pro-Pro-Nle-NH2 (compound 4; NK-2 pKB = 5.9; NK-1 pKB = 4.7; NK-3 pKB less than 4.6). Addition of a suitable lipophilic N-terminal substituent (e.g. Boc, PhCO, cyclohexylcarbonyl) to this compound greatly enhanced NK-2 antagonist activity (compound 10, GR 83074; NK-2 pKB = 8.2), and combined with further optimization of the N-terminal amino acids, provided the extremely potent and selective NK-2 antagonist PhCO-Ala-Ala-D-Trp-Phe-D-Pro-Pro-Nle-NH2 (compound 34, GR 94800; NK-2 pKB = 9.6; NK-1 pKB = 6.4; NK-3 pKB = 6.0). Compounds of this class produced a potent inhibition of NK-2 agonist-induced bronchoconstriction in the anaesthetized guinea-pig.
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A voluntary community-based preregistration year (internship) was created for graduates of a community-oriented medical school in Beersheva, Israel. Graduates were placed in community clinics which had been upgraded to meet the needs of the programme through provision of on-site laboratory facilities and specialist consultation, and placement of social workers and health education personnel in the clinics. The graduates participated in a weekly postgraduate education programme directed to their specific needs. There was a high degree of satisfaction with the programme among the trainees, the clinic team members and the patients. Relatively few of the trainees indicated a desire to pursue careers entirely devoted to primary care, despite their positive evaluation of the pre-registration experience. Though this might have been explained by problems encountered in the programme, such as the lack of adequate on-site supervision and lack of support from the health service providers, external factors such as a general move of graduates towards more lucrative subspecialties and the relative lack of status of family practice were probably the more significant reasons. Increasing focus on the internship year, in addition to the undergraduate and residency periods, is needed to help direct medical education to ambulatory settings.
A child with the distinguishing characteristics of Weissenbacher-Zweymuller syndrome (WZS), a rare syndrome characterized by multiple skeletal and radiological abnormalities, dwarfism and developmental delays, was followed from birth to eight years. Follow-up showed that the radiographic anomalies eventually disappeared, and that height, motor, cognitive and language development returned to normal by eight years of age. The child's normal development at school age supports the theory that WZS is a dysmaturational, rather than dysplastic, syndrome. Diagnosis of the syndrome at birth is essential to ensure proper management of the child and counselling for the parents.
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A trial has been initiated testing the effects of high dose radiolabeled monoclonal antibody administered in conjunction with marrow transplantation for treatment of lymphoma. This study is based on observations in mice demonstrating that radiolabeled antibody against a normal lymphocyte-associate antigen can induce regression of lymphoma masses. These preclinical studies also showed that large amounts of antibody are needed to achieve adequate biodistribution in vivo and that potentially curative doses of radionuclide induce substantial hematopoietic toxicity. Consequently, in patients with recurrent lymphoma, we are first evaluating the influence of dose on the biodistribution of a pan B-cell antibody, MB-1 (anti-CD37). In four patients, the biodistribution studies indicated that at the highest amount of antibody tested 131I-labeled antibody MB-1 (10 mg/kg) could deliver more radiation to tumor than to normal organs. These patients were treated with antibody MB-1 labeled with 250 to 482 mCi 131I estimated to deliver 380 to 1570 cGy to normal organs and 850 to 4260 cGy to tumor. Myelosuppression occurred in all patients and required infusion of cryopreserved marrow in one patient. Complete tumor regressions were observed in each patient. In three other patients with splenomegaly and/or large tumor burden, biodistribution studies indicated that 131I-labeled antibody could not deliver more radiation to tumor than to normal organs and these patients were not treated. Thus, tumor burden and spleen size may determine the feasibility of treatment with radiolabeled antibody. Treatment with this antibody labeled with high doses of 131I was well tolerated and may prove therapeutically useful. These studies are being continued to determine the maximal doses of radiation that can be tolerated by nonhematopoietic tissues after infusion of 131I-labeled antibody.
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Maternal incompetence in childrearing is described in three widely different cultural settings in the southern Negev area of Israel. It is suggested that this incompetence stems from "abandonment" of the parents by traditional family support systems and is reinforced by the inability or lack of readiness of the health system to supply the missing support mechanisms. This picture of parental "abandonment" in widely different cultural settings in Israel may represent an end result of cultural and social upheaval common to other communities in the world. Techniques for prevention include improving awareness of health workers to this problem, teaching appropriate strategies for improving parental confidence and competence, and ensuring that maternal and infant care focuses appropriately on issues of infant behavior and parental concerns.