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Biomedical subjects

A Weiss

Publications and source records attributed to A Weiss.

At least 361 records · Page 20Linked to original sources

Role of T3 surface molecules in human T-cell activation: T3-dependent activation results in an increase in cytoplasmic free calcium.

The human T-cell leukemia, Jurkat, and a T3-negative mutant of Jurkat (S.5) were used to study the role of T3 in human T-cell activation. Incubation of Jurkat with phytohemagglutinin (PHA) resulted in the production of interleukin 2, which was markedly increased by the addition of phorbol 12-myristate 13-acetate (PMA). Antibodies reactive with T3 could activate Jurkat only if added together with PMA. However, S.5 cells failed to produce interleukin 2 in response to PHA and produced 1/16th the interleukin 2 activity that Jurkat produced in response to PHA and PMA. Incubation of S.5 cells with the calcium ionophore A23187 and PMA resulted in the production of interleukin 2 activity comparable to that produced by Jurkat. Like antibodies reactive with T3, A23187 demonstrated an obligate requirement for PMA in order to activate Jurkat or S.5. These observations suggested that T3 might participate in T-cell activation through mechanisms that increase intracellular Ca2+. This was examined by using the Ca2+ sensitive fluor, quin-2, to measure levels of cytoplasmic free Ca2+ [( Ca2+]i). Addition of PHA, A23187, or monoclonal antibodies reactive with T3 to Jurkat cells resulted in substantial increases of [Ca2+]i. In contrast, only A23187 could induce an increase in [Ca2+]i in S.5 cells. Three other monoclonal antibodies reactive with other membrane antigens expressed on Jurkat or S.5 did not increase [Ca2+]i. These results suggest that T3 and/or associated molecules participate in T-cell activation through mechanisms that lead to increases in [Ca2+]i and that their expression is a relative requirement for T-cell activation by PHA.

Animals↗

Ocular manifestations of the neurocutaneous syndromes.

Ocular involvement occurs frequently in the disorders known as neurocutaneous syndromes or phakomatoses. Recognition of characteristic eye lesions in the context of related skin and systemic abnormalities may be crucial to making the diagnosis of a neurocutaneous syndrome. Ocular disease in these conditions may be the cause of serious morbidity, leading to blindness or disfigurement, but successful treatment is often possible. All clinicians involved in the care of patients with neurocutaneous syndromes should have some familiarity with their ophthalmologic aspects. This review deals with ocular manifestations of neurofibromatosis, tuberous sclerosis, Sturge-Weber syndrome, von Hippel-Lindau disease, ataxia telangiectasia, and Bloch-Sulzberger syndrome. Clinical signs and symptoms, differential diagnosis, and natural history are considered in detail, with brief discussion of pathophysiology and management. No specialized knowledge of eye disease in general is presumed.

Ataxia Telangiectasia↗

The role of T3 surface molecules in the activation of human T cells: a two-stimulus requirement for IL 2 production reflects events occurring at a pre-translational level.

The human T cell leukemia Jurkat was used as a model to examine the requirements of T cell activation. These studies demonstrated that antibodies reactive with the T cell-specific T3 antigen were insufficient to result in the activation of Jurkat cells, determined by the secretion of IL 2. IL 2 production occurred only in the presence of a second stimulus, the phorbol ester PMA. With the use of an IL 2-specific cDNA probe, the appearance of IL 2 RNA, similarly, occurred only when cells were stimulated with both anti-T3 antibodies and PMA. These results demonstrate a two-stimulus requirement for gene expression in human T cells.

Antibodies, Monoclonal↗

Parent-child relationships of adopted adolescents in a psychiatric hospital.

This study compared the parent-child relationships of 140 adopted and non-adopted adolescents treated in a psychiatric hospital through examination of information contained in the adolescents' medical records. Specifically, comparisons were made of the mention of parental contribution to the problems precipitating hospitalization, psychiatric restriction of parental visits to hospitalized offspring, and referral of parents to an adjunct parents' group. Data were gathered by uninformed research assistants, from the hospital charts of adolescents who had already been discharged from the hospital. Statistical analysis of the data yielded the following results. Adoptive parents were significantly more frequently restricted in their visits to their children. In addition, they were also more likely to have been involved in the precipitants to hospitalization and to have been referred subsequently for adjunctive treatment. It was concluded that parent-child relations may be more problematic among hospitalized adopted, as compared with non-adopted , adolescents. It was also suggested that psychiatric bias concerning "typical" adoptive family dynamics might have contributed to the observed differences.

Adjustment Disorders↗

[Non-caloric compounds with fat-like functional properties (pseudofats)].

The review deals with the synthesis, characterization, physicochemical and physiological properties with respect to nutrition of acaloric fat-like compounds (pseudofats) with special regard to fatty acid esters of sucrose, glycerol ethers and glycerol dicarbonic acid esters. Furthermore an outlook is given of other classes of compounds that are potentially suited to substitute fat as for instance polycarbonic acid-, polyglycerol-, and polyglycol derivatives.

Chemical Phenomena↗

Morphometric analysis of aging skeletal muscle following endurance training.

Aging of skeletal muscle in the hindleg of the mouse is accompanied by a progressive increase in the amount of the interstitial tissue and especially that of lipid cells and fibroblasts. Quantitative analysis indicates that there was a nonsignificant increase in the total number of muscle fibers per unit area, perhaps due to a splitting process. The proportion of high oxidative fibers was decreased to a nonsignificant degree, and the remaining high oxidative fibers underwent a significant compensatory hypertrophy. Concomitantly, the number of low oxidative fibers increased significantly. This study revealed that endurance training in young animals induced morphometric changes very similar to those noticed in intact aging animals (i.e., splitting phenomenon, hypertrophy of high oxidative fibers, and an increased proportion of low oxidative fibers). It also became apparent that the skeletal muscle of old animals lacks the capacity to respond to enforced training, except for a further increase in the proportion of low oxidative fibers. It appears that aging muscle is unable to adapt to changing environmental circumstances.

Aging↗

Bacterial periorbital and orbital cellulitis in childhood.

The clinical features, microbiologic data, complications, and treatment in 137 children with periorbital cellulitis and 21 children with orbital cellulitis is presented. Periorbital cellulitis was more frequent (87%) than orbital cellulitis (13%). Periorbital cellulitis is a heterogeneous disease that may complicate trauma of the eyelids, external ocular infection, and upper respiratory infection. Children with periorbital cellulitis related to trauma or external infection tended to be less than 5 years old with negative blood cultures (99%) and positive cultures of percutaneous aspirates (42%); while children with periorbital cellulitis related to upper respiratory infection also tended to be less than 5 years of age, but blood cultures were frequently positive (42%) and cultures of percutaneous aspirates were usually negative (92%). Three children in the latter group developed meningitis. Intravenous antibiotic alone was effective treatment in most patients (90%). Orbital cellulitis was more frequent in children older than 5 years and frequently associated with sinusitis (90%). Blood and skin cultures were usually negative. Intravenous antibiotics alone were effective management in many patients (62%), but a significant proportion required paranasal sinus or orbital surgery (38%).

Bacterial Infections↗

[Frequency of kidney cyst wall cancer--results of 22,000 ultrasound studies].

In 22 198 sonographic examinations of the epigastric region, the authors identified 759 renal cysts (3.4%) and 165 renal tumours (0.74%). The percentage of incidence of the renal cysts is identical with that found in post-mortem examinations, whereas tumours were distinctly more frequent. Tumours of the cystic wall had been found in 0.5% of all sonographically diagnosed cysts and in 4% of renal cysts examined via fine-needle biopsy. Of the latter cysts (i.e. out of the 4% of cysts diagnosed by fine-needle biopsy), which were associated with tumours, two had been diagnosed as tumour suspects via sonography. Hence, the sonographic absence of abnormal findings in carcinoma of the renal cyst wall is rare. However, cysts diagnosed via sonography which cannot be subjected to fine-needle biopsy, should be rechecked and followed up at regular intervals. If all possible methods of diagnosis are utilised (I.V. urography, sonography, fine-needle biopsy guided by sonography, computed tomography, angiography), successful differential diagnosis of localised pathological conditions of the kidneys can be achieved in 97% of all cases. Patient risk and cost of diagnosis can be kept at a minimum by proceeding in steps as described in the article. Primary surgical exposure of the kidneys in case of a cystic renal process would now appear justified for therapeutic reasons only, not for the purpose of arriving at a diagnosis.

Adenocarcinoma↗

Renal osteodystrophy in end-stage renal failure patients in Israel.

Renal osteodystrophy is one of the major complications in patients on long-term hemodialysis. A group of 42 patients on hemodialysis (mean age 42 yr) were investigated in order to assess the prevalence of renal osteodystrophy in Israeli patients. The patients were examined by X-ray, and 66.7% were found to have signs of osteodystrophy. Of 14 patients without signs of bone involvement, 10 had been on treatment less than 1 yr. A bone biopsy, performed in 28 patients (mean age 43 yr), showed signs of renal osteodystrophy in all. Two of these patients were diagnosed as having mainly osteitis fibrosa, four as having osteomalacia and the rest as having the symptoms of both.

Adult↗

Intraaortic balloon counterpulsation in acute myocardial infarction.

Intraaortic balloon counterpulsation was undertaken in 24 patients with acute myocardial infarction. The patients were divided into four groups: severe left ventricular dysfunction (11 patients), mechanical lesions (6), intractable angina pectoris (6) and refractory ventricular tachycardia (1). The clinical condition and the hemodynamic measurements improved dramatically in 21 patients, but there were only 9 long-term survivors. Intraaortic balloon counterpulsation gave the best results in patients with preinfarction angina pectoris or patients with left ventricular dysfunction where the hemodynamic status deteriorated after an acute but reversible cardiovascular event. Numerous local complications were observed.

Adult↗