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Biomedical subjects

H Isaacs

Publications and source records attributed to H Isaacs.

At least 109 records · Page 6Linked to original sources
PubMed1977

The muscles in club foot--a histological histochemical and electron microscopic study.

In talipes equino-varus the diminished bulk of the calf muscle suggests a neuromuscular defect. Accordingly, biopsies were taken from the postero-medial and peroneal muscle groups, and occasionally from abductor hallucis, in sixty patients mostly under the age of five years; 111 were studied histochemically and histologically, and a further fifty-three by electron-microscopy. Histochemical anomalies were revealed in ninety-two specimens; the muscle fibres in the other nineteen varied in size but were abnormal at the ultramicroscopic level, as were all specimens examined with the electron microscope. Evidence of neurogenic disease was seen in most instances and was more obvious in the older patients. The pattern of abnormality was similar in both muscle groups. It is thought that shortening of the postero-medial muscles may result from a small increase of fibrosis due to minor innervation changes occurring in intra-uterine life. There is evidence that immobilisation, stretching or relaxation of muscles does not account for the anomalies observed. This study of the extrinsic muscles in talipes equino-varus indicates a dominant neurogenic factor in its causation.

Biopsy↗
PubMed1977

Pulmonary sequestration in children: a twenty-five year experience.

Pulmonary sequestration occurs when some disturbance produces a cystic mass of nonfunctioning lung tissue which lacks normal communication with the tracheobronchial tree. In most cases the sequestered pulmonary tissue receives its blood supply from anomalous systemic vessels. This paper considers 15 children, 11 boys and four girls, ranging in age from one day to 14 years, with ten extralobar sequestrations and five intralobar pulmonary sequestrations. Although roentgenographic examination of the chest may suggest the diagnosis, conclusive diagnosis can only be obtained by arteriography and/or surgical exploration. Arteriography is strongly advocated in all cases, not only for its diagnostic value, but for its preoperative localization of the aberrant blood vessels that are the major technical concern to the surgeon.

Adolescent↗
PubMed1977

Surgical treatment of hyperthyroidism in children.

During the past ten years, subtotal thyroidectomy for hyperthyroidism was performed upon 43 children at Childrens Hospital of Los Angeles. There were no deaths, no recurrent laryngeal nerve injuries and no permanent hypoparathyroidism. During the one to ten year follow-up period, one patient had recurrent hyperthyroidism develop and was treated with 131I. Twenty-five patients are hypothyroid and require thyroid supplement; 14 are euthyroid and receiv no medication. Postoperative thyroid function did not correlate well with gland remnant size, degree of fibrosis or the extent of lymphoid follicle formation. Lymphocytic infiltration was more severe in patients who had hypothyroidism develop postoperatively. Transient hypocalcemia developed in 22 patients. The effectiveness and safety of the surgical treatment for hyperthyroidism in children is reaffirmed, and it is advocated for consideration over 131I or prolonged medical therapy.

Adolescent↗
PubMed1976

Malignant hyperthermia syndrome--evidence for denervation changes in human skeletal muscle.

The presence of denervation-like changes and abnormal mitochondria in the muscle of carriers of the malignant hyperthermia syndrome suggest a neuropathic basis for the human syndrome. A defect in mitochondrial ATP synthesis resulting from denervation, and potentiated by some general anaesthetics, may be the primary muscle fibre lesion in the human malignant hyperthermic syndrome.

Adenosine Triphosphatases↗
PubMed1976

Structural abnormalities of muscle tissue in ankylosing spondylitis.

Muscle tissue of patients with ankylosing spondylitis has been studied by means of histology, histochemistry and electron microscopy and has been shown to be grossly abnormal. The underlying basis of the muscle changes is probably neuropathic and we believe that these changes form part of the over-all pathology of this disease.

Adult↗
PubMed1976

Carcinoma of the stomach in childhood.

A case of mucinous adenocarcinoma of the stomach is described in a 20-month-old child with a large abdominal mass. The lesion arose from the lesser curvature of the stomach and invaded the submucosa and lymphatic channels. A partial response to chemotherapy, including vincristine, Cytoxan, actinomycin D, and adriamycin, was noted, but the patient died 3 1/2 months following diagnosis shortly after gastric perforation and peritonitis developed. Autopsy revealed a pattern of widespread visceral metastases, accompanied by pathologic findings suggestive of ataxia-telangiectasia. A diagnosis of mucinous adenocarcinoma, although it is rare, should be considered in the evaluation of primary neoplasms of the stomach in children.

Adenocarcinoma, Mucinous↗
PubMed1976

Endotoxin clearance after intralipid infusion.

Healthy 6-8-wk-old New Zealand white rabbits were injected with chromium-chloride- or sodium-chromate-labeled E. coli endotoxin after rapid infusion (10 ml/kg in 1 hr) or slow and repeated infusions (40 ml/kg daily for 7 consecutive days) of 10% Intralipid. Endotoxin clearance rates and RES organ uptakes were determined and the results were compared with those of the controls treated with correspondingly equal volumes of 5% D/W instead of fat. In the acute experiment, the clearance rates were similar in all animals during the first 15 min following endotoxin injection. After this phase, however, experimental animals had faster endotoxin clearance and eventually higher organ uptakes than the controls. In the chronic experiment, there was no significant difference in endotoxin clearance rates or total and per-gram organ uptakes between experimental and corresponding control animals infused with 5% D/W instead of fat. Experimental animals, particularly those having received multiple infusions of fat emulsion, showed deposition of polarizable brown pigment inside and outside the reticuloendothelial cells in the liver, spleen, and bone marrow. None of the controls had these pigments in their organs.

Animals↗
PubMed1976

Weakness associated with the pathological presence of lipid in skeletal muscle: a detailed study of a patient with carnitine deficiencey.

A patient with muscular weakness demonstrating pathological lipid accumulation and abnormal mitochondria in skeletal muscle has been studied. The lipid accumulation and mitochondrial changes are thought to be related to the established deficiency of carnitine in this patient's muscle. The symptoms of muscular weakness associated with lipid accumulation in the skeletal muscle in the absence of complaint of muscle cramps or myglobinuria are thought to be diagnostic of carnitine deficiency. The failure of the sarcoplasmic reticulum to accumulate Ca2+ is discussed. The patient's strength responded dramatically when propranolol was added to his steroid therapy.

Adult↗
PubMed1975

'Picture frame' fibres in a carrier of the trait for malignant hyperpyrexia.

A member of a family which was known to be susceptible to malignant hyperpyrexia, who was identified as a carrier by the presence of an elevated serum creatine-phosphokinase, has been investigated further. Muscle was examined biochemically, and the study included the sarcoplasmic ATPase-activity, actinomycin, Mg2+ ATPase activity, ATP, phosphocreatine and glucose-6-phosphate. In addition, the calcium uptake by the sarcoplasmic reticulum was studied. The histochemical analysis of the muscle revealed the presence of a new fibre type characterised by a dense rim of ATPase activity, which gives the impression of a 'picture-frame'. Ultramicroscopic study revealed changes in the mitochondria and areas of myofibrillar disruption with swelling of the sarcoplasmic reticulum.

Adenosine Triphosphatases↗
PubMed1975

The relationship between tumorigenicity, growth in agar and fibrinolytic activity in a line of human osteosarcoma cells.

The TE-85 osteosarcoma cell line has several of the in vitro properties of malignant cells, including colony formation in agar, but has low extracellular fibrinolytic activity and no capacity to form tumors in ATS-treated hamsters. Some TE-85 cells clones (clones 2, 4 and 6) have increased fibrinolytic activity but do not form tumors in hamsters. TE-85 cells infected with mammalian transformation-defective viruses have low (FeLV) or increased (RD-114 virus) levels of fibrinolytic activity and do not form tumors in hamsters. TE-85 cell either nonproductively infected with Ki-MSV or productively infected with M-MSV (RD-114), have fibrinolytic activity and can form tumors in hamsters. The MSV gene(s) but not colony formation in agar or extracellular fibrinolytic activity appears to be capable of rendering TE-85 cells tumorigenic in ATS-treated hamsters.

Agar↗
PubMed1975

Xanthine, hypoxanthine and muscle pain. Histochemical and biochemical observations.

A suspected case of xanthine oxidase deficiency has been further investigated. The patient complained of arthralgia and myalgia. Further studies included histochemical and ultramicroscopic analysis of muscle sarcoplasmic reticulum, and biochemical studies. High levels of xanthine and hypoxanthine were found, while uric acid was absent in the muscle extracts.

Adenosine Triphosphatases↗
PubMed1975

Childhood sarcomas and lymphomas. Characterization of new cell lines and search for type-C virus.

Four cell lines were derived from childhood malignancies: rhabdomyosarcoma, sarcoma, lymphosarcoma and an American Burkitt's lymphoma. Cells of the four lines formed tumors in immunosuppressed newborn hamsters. The tumors had a microscopic appearance like that of the tumors from which the cell lines were derived. No virus-like particles were detected by electron microscopy in the cell lines after treatment with bromodeoxyuridine; no hamster type-C virus expression was present in cell lines derived from the hamster tumors. Chromosome constitution and in vitro growth properties of the cell lines were studied as was the fibrinolytic function of the sarcoma lines.

Adolescent↗
PubMed1975

The influence of chemotherapy on the prognosis of rhabdomyosarcoma.

A study of 77 consecutive cases of childhood rhabdomyosarcoma treated initially at the Children's Hospital of Los Angeles from 1950 to 1972 demonstrated an impressive improvement in survival of patients when intensive chemotherapy was occurred in Stage II and Stage III disease. Eight out of 9 patients with a primary lesion of the lower extremities developed intra-abdominal disease. A general approach for treatment of Stage II, III, and IV rhabdomyosarcoma is proposed which involves intensive chemotherapy, following biopsy, as the principle treatment, with radiation and surgery used as a adjuvants.

Adolescent↗
PubMed1975

Idiopathic cardiomyopathy and skeletal muscle abnormality.

The skeletal muscle of three cases presenting with idiopathic congestive cardiomyopathy has been studied, histologically, histochemically, ultramicroscopically, and electromyographically. In all three there is clinical evidence of skeletal muscle weakness, and in all three, pathologic changes were found in the muscle. These changes were different in each case and varied from mitochondrial myopathy to spinal atrophy to vacuolar myopathy. Other reported cases of cardiomyopathy demonstrating skeletal muscle pathology are discussed.

Adolescent↗