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Biomedical subjects

H Isaacs

Publications and source records attributed to H Isaacs.

At least 73 records · Page 4Linked to original sources
PubMed1984

Hemangiopericytoma in infants and children. A report of six patients.

The case histories of six infants and children (five male and two female) with hemangiopericytoma have been reviewed (two patients were born with the tumor). The tumor originated on an extremity in three patients, in the intranasal fossa in one, in the neck and upper mediastinum in one, and in the abdomen in another. In the patients with the tumor on the extremity, the lesion was removed with a margin of normal tissue. These patients remained well for 2,8, and 1.5 years after diagnosis. In the patient with an intranasal mass, the tumor was removed, but local recurrence developed 3 months later. The recurrent tumor was removed, and the patient remained well for 10 years. The patient with the neck and upper mediastinal tumor was born with the lesion and presented with airway obstruction at 2 months of age. This patient received radiotherapy and cyclophosphamide with no apparent response. He underwent partial excision of the lesion 1 month after diagnosis but died 1 month later from massive hemorrhage into the airway. The patient with the abdominal mass had extensive retroperitoneal tumor, and excision was not possible. He received chemotherapy and radiotherapy, and although the tumor decreased in size, osseous metastases developed 4 months after diagnosis. The metastatic lesions in this child disappeared with further chemotherapy, and at second-look operation 9 months after diagnosis, the tumor was removed. Postoperatively, new bone metastasis developed but again responded to chemotherapy with complete disappearance of the metastatic lesion. The patient had no evidence of disease 16 years after diagnosis.

Adolescent↗
PubMed1984

Transfusion-associated acquired immune deficiency syndrome in infants.

Two preterm infant boys not known to be at risk developed clinical, laboratory, and pathologic features of acquired immune deficiency syndrome (AIDS) after receiving multiple blood transfusions in the neonatal period. Their clinical courses were characterized by failure to thrive, recurrent otitis media, hepatomegaly, and fatal interstitial pneumonia. Laboratory evaluation revealed progressive lymphopenia, reversed T helper/suppressor ratios, increased percentages of B-lymphocytes, decreased lymphoproliferative responses to mitogens, hyperimmunoglobulinemia, and high levels of circulating immune complexes. At postmortem examination thymic involution, lymphocyte depletion in spleen and lymph nodes, and micronodular mineralization in the central nervous system were seen. The findings were not specific for other known congenital immune deficiencies and were most indicative of AIDS. The lack of other risk factors suggests transmission of AIDS via blood transfusions in the neonatal period.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Benign liver tumors in infancy and childhood. Report of 48 cases.

This is a clinicopathologic study of 48 patients with benign liver tumors seen during a 32 year period; 2 adenomas, 3 focal nodular hyperplasias, 14 mesenchymal hamartomas, and 29 hemangiomas were reviewed. All patients except those with adenomas were younger than 5 years. Thirty-four patients were symptomatic, 24 of whom were diagnosed by open liver biopsy, whereas 10 with hemangioma had their diagnoses based on clinical and radiologic findings. Death due to tumor occurred in four patients with hemangioma. Infants and children with liver hemangioma and congestive heart failure should receive steroids, digitalis, diuretics, and radiation, alone or in combination. If medical treatment is unsuccessful and the hemangioma is localized to one lobe, resection of the tumor can be performed, but if the lesion is massive, ligation or embolization of the hepatic artery should be considered.

Adenoma↗
PubMed1983

Improved survival in infants and children with primary malignant liver tumors.

Forty-six infants and children with primary malignant liver tumors were studied. Thirty-three had hepatoblastomas, 9 hepatocellular carcinomas, and 4 had sarcomas. Thirty-eight patients underwent liver biopsy or excision of the tumor. Nineteen patients were treated between 1952 and 1971 (mean survival 5.5 months) and the remaining 19 were treated between 1972 and 1981 (mean length of survival 30 months, 2 year survival rate 53 percent). In 21 patients with an unresectable tumor, biopsy alone was performed (mean survival 7 months). Ten patients underwent primary resection of their liver tumor (mean length of survival 23 months, 2 year survival rate 37.5 percent). Seven other patients with an unresectable tumor were treated with chemotherapy alone or in combination with radiotherapy for a mean period of 6 months before second-look celiotomy was carried out. Six of these patients (all treated after 1975) had significant reduction in the size of their tumors. Mean length of survival in this group was 4 years 2 months, and the 2 year survival rate was 100 percent; at present, 5 of these patients are living without the disease 2.5 to 7 years after diagnosis. Improved techniques in liver resection and chemotherapy before second-look celiotomy is undertaken for an unresectable lesion have improved prognosis in children with a malignant liver tumor.

Adolescent↗
PubMed1983

Respiratory activities of subsarcolemmal and intermyofibrillar mitochondrial populations isolated from denervated and control rat soleus muscles.

Ultraturrax and Nagarse released populations of mitochondria isolated from control and day 21 denervated rat soleus muscle were characterized with respect to their oxidative phosphorylation, ADP translocase and ATPase activities. Both Ultraturrax and Nagarse released mitochondrial populations displayed lower capacities for oxidative phosphorylation; lower ADP translocase activities and higher Mg2+ stimulated ATPase activities than their corresponding controls. For both the denervated and control states, the Nagarse-released mitochondrial populations displayed significantly higher respiratory activities than the Ultraturrax released fractions. The significance of these findings is discussed with regard to the process of mitochondrial respiratory control. In addition the role of mitochondrial dysfunction in denervation muscular atrophy is assessed.

Adenosine Triphosphatases↗
PubMed1983

Invasive properties of primary pediatric neoplasms in vitro.

Primary solid tumors were mechanically and/or enzymatically disassociated, and the resulting suspensions of single cells and small clumps of cells were seeded onto three different substrates, i.e., tissue culture plastic, rat smooth muscle cells (SMCs), and SMC-derived extracellular matrix. Tests of the relative effectiveness of these substrates in supporting the survival and/or growth of ten different neoplasms demonstrated that only two explants remained viable for longer than 2 weeks when seeded onto tissue culture plastic while nine of the ten survived on biological substrates for 1 month or longer. Thus, tissue culture plastic was a poor substrate for primary pediatric neoplasms. In general, more than 80% of the most common solid neoplasms in childhood (brain tumor, neuroblastoma, renal tumor, rhabdomyosarcoma, osteogenic sarcoma, and Ewing's sarcoma) routinely survived or grew in long-term cultures when cultured onto SMCs or their matrix. Both substrates were effective in promoting survival and/or growth; however, cells of neuroblastomas and certain brain tumors showed a preference for a living smooth muscle substrate. Tumor cells maintained their characteristic cellular and subcellular morphology when compared with the histology of the in vivo neoplastic lesions. Light and electron microscopy of selected neoplasms cultured on SMCs for various time periods demonstrated areas of distinct cellular invasion and/or partial destruction of the SMC multilayers which correlated with the invasive potentials of the neoplasms in patients. Invasion and destruction of the SMCs were also noticed with quiescent tumor cell cultures, indicating that growth was not a necessary property of invasion. Several neoplasms were also capable of the degradation of connective tissue proteins as indicated by the hydrolysis of radiolabeled SMC matrices, but simple correlations between the extent of matrix degradation and invasive ability could not be drawn. The culture system described consistently provided for the survival and/or growth of the most common pediatric tumors for long time periods. Thus, basic biological properties of primary tumors, e.g., growth, invasive potentials, and differentiation capabilities, could be investigated routinely.

Cell Transformation, Neoplastic↗
PubMed1983

Patterns of Hodgkin's disease at diagnosis in young children.

A retrospective analysis of 125 consecutive cases of Hodgkin's disease, seen at a pediatric institution, was conducted and 28 patients under the age of 7 years (young children) were selected for comparison with a control population, aged 7 or more years. Male to female ratios were: young children, 4.6:1 vs. 1.2:1 for the controls. Symptoms at diagnosis were present in 20% of patients under age 7 and in 42% of the others. Limited Hodgkin's disease (stages I and IIA) was found in 57% of young children and in 33% of the controls, while advanced disease (stages IIIB and IV) was diagnosed in 12% of young children and in 38% of the others. Histologic types differed as follows: the young group--lymphocyte predominance (LP) 21%, nodular sclerosis (NS) 50%, mixed cellularity (MC) 29%, and lymphocyte depletion (LD) 5%, vs. the controls--LP 5%, NS 73%, MC 17%, and LD 5%. Hodgkin's disease in the young child differs from that in older populations and appears to have a favorable distribution of prognostic criteria.

Adolescent↗
PubMed1982

Pulmonary blastoma associated with cystic lung disease.

A 2 1/2-year-old child with chronic cystic lung disease also had a large pulmonary tumor develop. A diagnosis of pulmonary blastoma, a rare primary malignant tumor of the lung, was made on pathologic examination. A review of the literature yielded reports of several patients with pulmonary blastoma who had either preexisting or concurrent cystic lung disease. Patients with chronic cystic pulmonary disease may have a predisposition for this malignant tumor.

Carcinoma, Squamous Cell↗
PubMed1982

Pseudorheumatoid nodule involving the orbit.

We report a clinicopathologic study of an unusual case of pseudorheumatoid nodule involving the right orbit of a child. Pathologically, the orbital lesion was similar to subcutanous nodules of rheumatoid arthritis and rheumatic fever. The physical findings and laboratory studies in our case did not reveal any evidence of systemic disease. Based on a review of reported cases involving other locations, this lesion appears clinically benign in children.

Child↗
PubMed1982

Metastatic medullary thyroid carcinoma in young children with mucosal neuroma syndrome.

Multiple endocrine neoplasia, type 2b (MEN 2b) is a disorder characterized by a distinct phenotype and a predisposition for medullary thyroid carcinoma (MTC) and pheochromocytoma. Two siblings aged 3 and 6 years with MEN 2b, who had elevated plasma calcitonin levels suggesting the presence of MTC are described. Microscopic foci of MTC were found in their thyroid glands and the glands were removed. In the younger child, a metastatic focus was present in a cervical lymph node. Of 12 previously reported children with MEN 2b and MTC who were less than 10 years of age at diagnosis, five had metastases. One of the present patients is the youngest described with this complication. The high frequency of metastases in very young patients with this syndrome has not been emphasized previously. These findings indicate the need for early diagnosis of MEN 2b and the importance of thyroidectomy at the earliest possible age when MTC is suspected by calcitonin screening tests.

Adult↗
PubMed1981

Ca2+-uptake properties of two populations of mitochondria from normal and denervated rat soleus muscle.

Ultraturrax- and Nagarse-released populations of mitochondria were characterized with respect to their Ca2+-uptake activities (i) by means of the indirect polarographic technique and (ii) directly by the 45Ca Ruthenium Red-quench method of Reed & Bygrave [(1974) Biochem. J. 140, 143-155]. The denervated-muscle subsarcolemmal and intermyofibrillar mitochondrial fractions displayed markedly decreased rates and capacities for Ca2+ uptake compared with their respective controls. The implications of these findings with respect to the process of cell necrosis are discussed.

Animals↗
PubMed1981

Characteristics of sarcoplasmic reticulum from normal and denervated rat skeletal muscle.

Denervation of rat skeletal muscle produces after 14 days a decrease in Ca2+ uptake of a heterogeneous population of sarcoplasmic-reticulum vesicles, when measured in the presence of oxalate. The Mg2+-dependent ATPase (Ca2+-independent) activity increased after the same period and the Ca2+ + Mg2+-dependent ATPase activity decreased. Concomitant with these changes, there was an increase in vesicle size and calcium content. The observations are discussed in terms of changes in altered membrane structure, manifested in the shift of the equilibrium of the ATPase from an enzyme involved in calcium transport to a phosphoenzyme giving rise to an increase in the Mg2+-dependent ATPase activity.

Adenosine Triphosphatases↗
PubMed1981

Increased muscle calcium. A possible cause of mitochondrial dysfunction and cellular necrosis in denervated rat skeletal muscle.

Mitochondrial preparations derived from denervated rat skeletal muscle and paired controls were characterized with respect to their ability to take up externally added Ca2+. The denervated and control muscle homogenates and mitochondrial [Ca2+] were also determined. Our data indicate that the denervated mitochondria are able to take up less Ca2+ than the controls before uncoupling occurs. This defect is associated with elevated [Ca2+] in homogenate and mitochondrial fractions in the denervated state. The causal relationship between Ca2+ overload, mitochondrial functional damage and cell necrosis is discussed.

Animals↗