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Biomedical subjects

H Isaacs

Publications and source records attributed to H Isaacs.

At least 91 records · Page 5Linked to original sources
PubMed1981

The role of a defined formula diet in the prevention of stress-induced gastric mucosal injury in the rat.

The role of a defined formula diet, Vivonex HN, in the prevention of gastric mucosal injury was evaluated in the cold, restrained rat model. The mean grade of gastric bleeding and mean number of gastric lesions were 3.95 and 7.35 +/- 1.02, respectively, in the stressed, unprotected control group. In four random groups of rats given Vivonex HN, Maalox, Cimetidine (20 mg/kg) and Cimetidine (60 mg/kg) prior to stress, the mean grade of gastric bleeding was 0; 1.55; 2.33; 1.75; and the mean number of gastric lesions was 0; 1.2 +/0 0.31; 2.83 +/0 0.82; 2.2 +/- 0.65, respectively. The differences were statistically significant. Our experiments show that Vivonex HN was more effective than Maalox or Cimetidine in high dose in preventing gastric bleeding and gastric mucosal lesions in the cold, restrained rat. Cimetidine in a standard dose was the least protective. Clinical trials are needed to establish the role of Vivonex HN in the prevention of stress ulcers in patients at risk.

Aluminum Hydroxide↗
PubMed1981

Rectal suction biopsy for the diagnosis of Hirschsprung's disease.

The diagnosis of Hirschsprung's disease is at times difficult, particularly in the young patient. Since 1972 we have used rectal suction biopsy as a screening technique in neonates and infants with failure to pass meconium or evidence of obstruction. In addition, it is used to confirm the diagnosis of Hirschsprung's disease when suspected by barium enema study. This technique has been used in 444 patients, 302 of whom were less than one year of age. No anesthesia is necessary, and there have been no associated complications. Only one patient early in the study had an initial misdiagnosis. There have been no false-positive or false-negative specimens since this initial problem, and no patients have undergone inappropriate pull-through procedures for suspected Hirschsprung's disease. It is recommended that all neonates who do not pass meconium in the first 48 hours of life undergo rectal suction biopsy to establish the diagnosis of congenital megacolon.

Biopsy, Needle↗
PubMed1981

Lymphoid interstitial pneumonitis and hypogammaglobulinemia in children.

Lymphoid interstitial pneumonitis is an uncommon process, and an association with hypogammaglobulinemia in children is rare. Three patients, a 10-yr-old boy (Patient 1), a 17-yr-old girl (Patient 2), and a 13-yr-old boy (Patient 3) were evaluated for progressive interstitial pneumonitis and hypogammaglobulinemia. At presentation, symptoms or signs of lung disease had been present for 9, 6, and 1.5 yr and consisted of severe exertional dyspnea asymptomatic pneumonitis on roentgenogram, and mild exertional dyspnea, respectively. Serum immunoglobulin deficiencies were variable with IgG and IgA being depressed in all patients and IgM being within normal limits in Patient 2. In vitro neutrophil function and T lymphocyte number and mitogen responses were normal. Measurement of in vitro immunoglobulin production suggested a primary B lymphocyte dysfunction. Pulmonary function testing revealed restrictive lung disease in Patient 1, arterial hypoxemia in Patients 1 and 2, and increased alveolar-arterial oxygen differences in all patients. Microscopic examination of lung specimens from each patient revealed diffuse lymphoid parenchymal infiltration with formation of follicles with occasional germinal centers, varying degrees of fibrosis, and negative examinations for viruses, bacteria, and fungi. The factors responsible for the cessation of antibody production and for the striking lympho-proliferative process seen in these patients remain to be identified.

Adolescent↗
PubMed1981

Extraneural metastatic medulloblastoma during childhood.

From 1960 to 1977, 59 patients with histologically confirmed medulloblastoma were initially treated at Childrens Hospital of Los Angeles. Of this group, 49 have died and, of these, 34 were autopsied. Among the autopsied cases, 2 infants had neck masses that proved to be medulloblastoma that had spread from the cerebellar vermis before any surgical intervention. Four additional patients who had undergone a posterior fossa craniectomy without either the pre- or postoperative placement of a cerebrospinal fluid-diverting shunt were found to have extraneural metastatic medulloblastoma at autopsy. The extraneural metastatic medulloblastoma rate in the autopsied cases was 17.6% (6 of 34). Our series shows that the incidence of the extraneural spread of medulloblastoma is associated with being young, being male, and having diffuse tumor involvement of the subarachnoid space.

Age Factors↗
PubMed1981

Effect of enteral calorie/nitrogen ratios on weight gain and liver function and morphology in rats.

Seventy-five Simonson albino male rates, each weighing 200-300 grams, were randomly divided into five groups of fifteen rats each. Group I, the controls, received rat chow which provided a calorie/nitrogen ratio of 95 Kcal/gram/nitrogen. Animals in Groups II to V received an elemental diet with calorie/nitrogen ratios of 100, 150, 300 and 450 Kcal/gram/nitrogen each, respectively. During the 30-day experimental period, daily calorie intakes were recorded and the rats were weighed every third day. Pre- and post-treatment hepatic function and fatty infiltration were analyzed and compared. The animals treated with a calorie/nitrogen ratio of 100-150 calories/gram of nitrogen had a statistically significant better weight gain with less fatty infiltration of the liver when compared to the other groups. This study supports the clinical impression that administration of lower calorie/nitrogen ratios is associated with a better weight gain.

Animals↗
PubMed1980

Multicore disease.

Two additional cases of multicore disease are presented, the main reason being the rarity of presentation in adults. It would appear that when this disease occurs in adults the prognosis is not as benign as when it occurs in infancy. We were able to confirm that the serum enzyme levels are normal in this disease and that the condition is best shown up with oxidative enzyme staining. There is a gradual disappearance of the type 1 motor neurons so that, by adulthood, the number of type 2 fibres is extremely few. In this respect the disease bears a similarity to central core disease and nemaline rod disease.

Adult↗
PubMed1980

Medulloblastoma presenting as neck tumors in 2 infants.

Extension of neuroepithelial neoplasms outside the neuraxis, though uncommon, is well known and usually follows surgical intervention. More unusual is the brain tumor that appears beyond the bounds of the central nervous system prior to operative manipulation. Two infants presented with soft tissue masses in the neck that proved to be medulloblastomas. Autopsy examination in both infants showed primary medulloblastoma of the cerebellar vermis with extensive spread through the subarachnoid spaces. The neck masses may have been direct extensions from the central nervous system tumors, though this was not proved in either case.

Cerebellar Neoplasms↗
PubMed1980

Primary malignant tumors of the stomach in children.

Primary malignant tumors of the stomach are rare in children. During the years 1952--1977, eight children were seen at Childrens Hospital of Los Angeles with primary malignant tumors of the stomach. The patients were between the ages of 20 mo and 17 hr and included 5 males and 3 females. The series consisted of 3 malignant lymphomas, 2 adenocarcinomas, 2 leiomyosarcomas, and 1 rhabdomyosarcoma of the stomach. Three patients are living and five are dead. Clinical histories, treatment and pathologic findings are described along with a review of the literature and recommendations for the management of primary gastric malignancies in children.

Adenocarcinoma↗
PubMed1979

Multilocular cyst of the kidney.

Five cases of multilocular cyst of the kidney are presented with a follow-up of 8 mo to 13 yr. Two children were treated with partial nephrectomy and three with nephrectomy. Radiation therapy and chemotherapy were not given pre- or postoperatively. Ultrasonography is helpful in preoperative diagnosis of this lesion. A brief review of the literature, differential diagnosis, possible etiology, preoperative evaluation and treatment are discussed.

Child, Preschool↗
PubMed1979

Stiff man syndrome in a black girl.

A patient suffering from severe and continuous muscular spasms is presented. The condition has been classified as the stiff man syndrome and is the first case recorded of the condition in a young African girl. The electrophysiological, biochemical, histochemical, and ultramicroscopic aspects of this disorder have been studied. The spasm appears to be related to overproduction of brain noradrenaline.

Black People↗
PubMed1978

Primary chemotherapeutic management of unresectable and metastatic hepatoblastoma in children: report of four cases.

Four children presenting with unresectable hepatoblastomas and one with metastatic disease are reported. Following initial biopsy all were treated with chemotherapy which included Adriamycin. Three of the four children showed a significant reduction in tumor size, and in two, delayed resection of the primary lesion was possible. Chemotherapy including Adriamycin represents effective initial cytoreductive therapy for childhood hepatoblastoma, thereby reducing the morbidity and mortality associated with the extensive hepatic resection usually required for an untreated lesion.

Adolescent↗
PubMed1978

Clinical, endocrinological, and enzymatic characterization of two patients with 5 alpha-reductase deficiency: evidence that a single enzyme is responsible for the 5 alpha-reduction of cortisol and testosterone.

Two siblings with 46,XY male pseudohermapthroditism were demonstrated to have the phenotype characteristic of 5 alpha-reductase deficiency, namely normal testes and male Wolffian duct derivatives (epididymis, vas deferens, and seminal vesicle) terminating in a blind-ending vagina. Clitoromegaly was present at birth and increased further at the time of expected puberty. The diagnosis of 5 alpha-reductase deficiency was confirmed by demonstration of male levels of testosterone and testosterone precursors before and after hCG administration, elevated plasma testosterone to dihydrotestosterone and urinary etiocholanolone to androsterone ratios, and by in vitro studies indicating 5 alpha-reductase enzyme deficiency in the epididymis of one patient. Studies of control and mutant epididymal microsomes indicated that a single enzyme is responsible in the normal person for the 5 alpha-reduction of testosterone and cortisol (and probably other delta 4-3-ketosteroids as well) and that 5 alpha-reductase activity is undetectable for all substrates examined in the mutant. This finding explains why the formation of 5 alpha-reduced glucocorticoids is also defective in the disorder.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1977

Establishment of a human medulloblastoma cell line.

A cell line consisting of polygonal and fusiform cells was derived from a cerebellar medulloblastoma. Cells grew to high population density in liquid medium and formed colonies in agar medium. No neural or glial elements could be demonstrated in the cultured cells by electron microscopy nor were virus particles detected. The cells formed tumors in nude mice and in antithymocytic serum (ATS)-treated hamsters. The tumors had a microscopic appearance similar to that of the medulloblastoma from which the cell line was derived. The cell line and lines derived from the transplant tumors in two hosts had four common "marker" chromosomes as well as non-specific cytogenetic changes.

Animals↗
PubMed1977

An obscure inherited neuropathy characterized by pain and weakness.

Two brothers with inherited muscular atrophy and particular proneness to painful limbs are described. Symptoms of disease began at an early age with severe pains in the extremities. The pain is particularly aggravated by heat or fever and over the years has been associated with progressive muscular atrophy and sensory loss. A prominent feature of biopsy specimens was the tomaculous swellings which affected the myelin of the nerve axon and the motor nerve terminals.

Adolescent↗
PubMed1977

Peripheral neuromuscular changes in Parkinson's disease.

The muscle, nerve terminal and end plates of 3 patients suffering from idiopathic Parkinson's disease have been studied electrophysiologically, histologically, histochemically and electron microscopically. No characteristic neuromuscular features of parkinsonism were discernible. Four additional patients suffering from idiopathic parkinsonism complicated by diabetes, myasthenia gravis and spinal atrophy were also studied.

Aged↗
PubMed1977

Pathologic and immune factors in thyroid disease.

Thyroid glands from 33 children with hyperthyroidism and nine with juvenile lymphocytic thyroiditis were examined histologically and for IgG, IgA, IgM, and C3 by immunofluorescent staining. There was no significant difference between glands with JLT and those with hyperthyroidism in the degree of lymphoid infiltration or lymphoid follicle formation. In thyroiditis there was no correlation between the degree of histologic abnormalities and the presence of immunofluorescent staining for IgG, IgM, or IgA. In hyperthyroidism there was a correlation between the degree of histologic abnormalities and the presence of IgG. In both groups of patients LI and LFF were distinctly more severe in glands positive for C3. Postsurgical hypothyroidism correlated with LI but not with LFF, IgG, or C3.

Adolescent↗