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Biomedical subjects

A Kedar

Publications and source records attributed to A Kedar.

At least 37 records · Page 2Linked to original sources
PubMed1990

Lipid coating of paramagnetic microspheres reduces non-specific binding to Kelly neuroblastoma cells.

In an effort to reduce non-specific binding interactions (binding in the absence of antibody), sheep anti-mouse IgG1 (Fc) antibody linked to magnetic microspheres (also referred to as microbeads or beads) were treated with phosphatidylcholine (PC), phosphatidylglycerol (PG), or a mixture of PC and PG. The lipid-treated microspheres were mixed with Kelly neuroblastoma cells, which had been pre-labelled with Hoechst fluorochrome. After 30 minutes of incubation, the microsphere adherent cells were separated from the non-adherent cells and counted. PC or mixed lipid treatment of beads reduced nonspecific binding to 8.3%, compared to 25.8% in the untreated samples. PG, on the other hand, increased non-specific binding. Lipid treatment of beads did not adversely affect specific antibody mediated binding. When a non-specific antibody was added to the incubation mixture, non-specific binding of untreated control beads to cells was increased, but binding of PC-treated beads was unaffected.

Animals↗
PubMed1989

Neuroblastoma: imaging evaluation by sequential Tc-99m MDP, I-131 MIBG, and Ga-67 citrate studies.

Fourteen children with histopathologically confirmed neuroblastoma underwent sequential correlative imaging studies using I-131 MIBG, Tc-99m MDP, and Ga-67 citrate during various stages of the disease. Of the patients 86% showed I-131 MIBG accumulation in the primary tumoral site, whereas 71% showed Tc-99m MDP and 79% Ga-67 citrate uptake. In 86% at least one of the two latter radiopharmaceuticals concentrated in the primary tumor. The use of all three radiopharmaceuticals raised the detection rate to 93%. Of the osseous or extraosseous metastases 100% were detected by Tc-99m MDP studies. The I-131 MIBG studies were positive in 71% of the osseous metastases and in 70% of the extraosseous metastases. No Ga-67 citrate uptake was demonstrated in osseous metastases, although one extraosseous lung metastasis concentrated this radiopharmaceutical. Tc-99m MDP bone imaging was the best method for diagnosing metastatic spread of the disease and for monitoring the results of treatment. Primary tumor uptake was best indicated by I-131 MIBG. Both Ga-67 citrate and I-131 MIBG were superior to Tc-99m MDP with regard to accurately demonstrating the extent of primary tumors. Only Tc-99m MDP indicated the relationship of these tumors to the kidneys and neighboring osseous structures, providing early screening of kidney compression. Ga-67 citrate study was mainly indicated in tumors with catecholamine depletion, which failed to concentrate the other two radiopharmaceuticals. I-131 MIBG proved especially useful in detecting neuroblastoma with negative Tc-99m MDP and Ga-67 citrate studies and also proved to be helpful with those cases in which I-131 MIBG was planned for therapy. The following strategy is suggested for evaluating neuroblastoma.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Iodobenzylguanidine↗
PubMed1989

Behcet disease: long-term follow-up of three children and review of the literature.

Behcet disease is rare in children. There are only two reports of Behcet disease in childhood, describing seven patients. Three pediatric patients are described, in whom the age of onset ranged from 6 to 11 years. Aphthous stomatitis and arthritis were present in all of the patients; genital ulcers, iridocylitis, erythema nodosum, and CNS involvement were present in two patients. Other manifestations included Stevens-Johnson-like eruption, fever of unknown origin, and testicular involvement. All of the patients responded to glucocorticoids; two were also treated with colchicine and one was treated with chlorambucil. In two patients, follow-up of more than 10 years was done, with complete cure in one patient and benign course of illness in the other. Because of the rarity of the disease in childhood and the difficulty in making the diagnosis, there is not enough awareness by pediatricians concerning this disease.

Behcet Syndrome↗
PubMed1988

Neuroblastomas contain iron-rich ferritin.

The ultrastructure of neuroblastoma was examined using unstained sections so that ferritin particles could be identified by the electron density of their iron cores. Ferritin and hemosiderin were found in ten of 11 neuroblastomas that were examined when the patients first presented. The study was therefore expanded to an additional group of children, including some diagnosed by noninvasive procedures and given chemotherapy before the excision of their tumors. In this second group 12 of 20 specimens contained ferritin and hemosiderin in variable amounts. In both groups there was a tendency for patients with advanced disease to have increased amounts of iron compounds in the tumor tissue (Stage III and particularly Stage IV). Most Stage IV patients also had elevated serum ferritin levels. However, based on the available heterogenous material, no absolute relationship could be established between age, disease stage, tumoral storage iron, and the level of serum ferritin. The presence of ferritin in neuroblastoma may be linked to the elevated serum ferritin levels and may be implicated in tumorigenesis.

Child↗
PubMed1988

Rhabdomyosarcoma of the trachea.

A 12-year-old girl was admitted on two occasions to our department because of severe dyspnoea, necessitating emergency tracheostomy. On the second admission, a lateral neck X-ray demonstrated a globular tumour which was found to be an embryonal rhabdomyosarcoma. The patient received post-operative radiation therapy followed by two years of continued chemotherapy. She is now five years post diagnosis and requiring no further therapy for about three years and her condition remains in remission.

Child↗
PubMed1987

Sacroiliitis as a sole manifestation of Brucella melitensis infection in a child.

A case of a 12-year-old boy with sacroiliitis documented by positive Tc-99m MDP and Ga-67 scans is described. Isolation of brucella melitensis from the blood and bone marrow established the diagnosis. He responded promptly to docycycline therapy. Throughout the course of his disease this boy had neither fever nor other signs of brucellosis, and x-ray was normal.

Arthritis, Infectious↗
PubMed1985

Brain mass as a manifestation of very late relapse in nonendemic Burkitt's lymphoma.

A 4-year-old boy was diagnosed as suffering from Burkitt's lymphoma with abdominal and maxillary involvement. The child was from a nonendemic area for Burkitt's lymphoma, and no association with Epstein-Barr virus was found. Two years after the completion of therapy, (3.25 years later) the child developed a solitary brain tumor, which was completely excised and was diagnosed as Burkitt's lymphoma. No meningeal involvement was found. Very late relapse in nonendemic Burkitt's lymphoma is very rare, and its presentation as a solid brain mass without meningeal involvement has not been reported before.

Brain Neoplasms↗
PubMed1984

Ewing sarcoma of the hand: literature review and a case report of nonsurgical management.

A case of a 12-year-old girl with Ewing sarcoma of the third metacarpal bone is described. Following an incisional biopsy, radiation therapy and adjuvant chemotherapy were given. The girl is now 34 months postdiagnosis and 25 months off therapy in sustained complete remission and functionally normal right hand. Of the seven previously published cases only two are long-term survivors (one had disarticulation, and the other resection of the fourth and fifth rays).

Adolescent↗
PubMed1984

Methotrexate-related deaths in patients previously treated with cis-diamminedichloride platinum.

Among 106 patients treated with conventional-dose methotrexate (MTX) following prior therapy with cis-diamminedichloride platinum (CDDP), six died with clinical manifestations of MTX toxicity. Death occurred 6-13 days after the administration of 20-50 mg/m2 MTX. Toxicity included severe stomatitis and myelosuppression, which appeared in all six patients, skin rash in five, and diarrhea in four. Renal failure appeared in five cases and hepatic toxicity in four. All these patients had received MTX earlier without developing any serious toxicity. At the time of the last MTX administration, all had normal blood counts and also normal kidney and liver function tests. Prior therapy with CDDP may be responsible for this relatively high incidence of MTX-related deaths.

Aged↗
PubMed1983

The effect of single-dose radiation on cell survival and growth hormone secretion by rat anterior pituitary cells.

Cranial irradiation has been shown to impair growth hormone secretion in children. In this study a cell culture of dispersed rat anterior pituitary cells was exposed to single doses of radiation in the range of 100-1500 rad: Survival curves were obtained for the different anterior pituitary cell lines, and growth hormone secretion was measured in the tissue culture medium. Both survival and growth hormone secretion curves showed an initial shoulder in the range of 0-300 rad, followed by a decline between 300-750 rad. It is concluded that growth hormone secreting acidophilic pituicytes are sensitive to radiation at single doses greater than 300 rad.

Animals↗
PubMed1982

Long-term survival determinants in Wilms' tumor.

This is a retrospective report of 54 patients with the diagnosis of Wilms' tumor treated at Roswell Park Memorial Institute from 1946 to 1977. The age ranged from 1 month to 57 years with a mean of 7.2 years and a median age of 5 years. An analysis of the survival results showed that patients continued to die of disease until 66 months post-diagnosis, making the 5-year survival a much better evaluation criterion for this group than the traditional 2-year survival. Males fared significantly better in this series (p less than 0.01). This was not due to detectable differences in age group, or histology. While the older age group (more than 15 years old) showed a somewhat better survival outlook for the first 2 years post-diagnosis, this difference became negligible at 5 years post-diagnosis.

Adolescent↗
PubMed1981

Severe hypertension in a child with ganglioneuroblastoma.

A 26-month-old boy with Stage III abdominal ganglioneuroblastoma had tachycardia and hypertension. The hypertension increased following the institution of chemotherapy and necessitated the use of both alpha and beta adrenergic blocking agents to control the effects of the marked catecholamine production. After excision of the residual tumor, the blood pressure and urinary catecholamine excretion returned to normal. Histologic examination of this tissue under light microscopy revealed some sections of ganglioneuroblastoma as well as large areas of ganglioneuroma. Examination by electron microscopy demonstrated a moderate number of dense core neurosecretory-type granules in the cell bodies of the ganglion-like cells and an abundance of the same type of granules in the bundles of the interwoven cytoplasmic neural processes. To data, 32 months after diagnosis and 20 months off chemotherapy, the patient remains free of tumor and is in excellent general health. We postulate that the large number of secretory granules in this tumor permitted storage and release of markedly increased quantities of norepinephrine and resulted in a clinical profile similar to that associated with pheochromocytoma.

Abdominal Neoplasms↗
PubMed1981

Effect of postoperative chemotherapy and radiotherapy, on the survival of subcutaneously implanted Furth Wilms' tumor.

The effect of surgery, postoperative combination chemotherapy and postoperative radiotherapy was evaluated in subcutaneously implanted Wistar/Furth rat Wilms' tumor. Four groups were studied. Group A (controls, no treatment given) had a median survival of 44 days. Group B (surgical excision of the primary tumor on day 14 after implantation) showed a median survival of 77 days, with 40% tumor-free long-term survivors (sacrificed on day 175). Group C (excision followed by chemotherapy consisting of vincristine, actinomycin D and adriamycin) had a median survival of 61 days with 35% tumor-free long-term survivors. Group D received the same postoperative chemotherapy as well as radiotherapy and had 55% tumor-free long-term survivors. This tumor may serve as a treatment model for some human Wilms' tumor cases who do not respond well to current therapies.

Animals↗
PubMed1981

Failure of actinomycin D entrapped in liposomes to prolong survival in renal cell adenocarcinoma-bearing mice.

The potential prolongation of survival of actinomycin D entrapped in liposomes was examined in Balb C/Cr mice inoculated intrarenally with renal cell adenocarcinoma. There were five groups of animals: group A, a control group, received phosphate-buffered saline 0.3 cm3 i.p.; group B received free actinomycin D 300 micrograms/kg i.p.; group C received liposomes containing actinomycin D 300 micrograms/kg i.p.; group D received a mixture of free actinomycin D 300 micrograms/kg and empty liposomes i.p.; group E received empty liposomes i.p. The best median survival was of group D (free drug) - 54 days followed by group C (liposome entrapped actinomycin D) 45.2 days and group E (a mixture of free and entrapped actinomycin D) - 42 days. In vitro studies utilizing cell lines obtained from the tumor showed no statistical difference in ID50 or in cytotoxicity between the cells treated with free actinomycin D and those treated with liposomes containing drug.

Adenocarcinoma↗
PubMed1980

Effect of actinomycin D-containing lipid vesicles on murine renal adenocarcinoma.

Forty Balb C/CR mice inoculated with renal cell adenocarcinoma were divided into five groups. Group A (seven animals) received phosphate buffered saline intraperitoneally; group B (seven animals) received free actinomycin D 300 microgram/kg IP; group C (nine animals) received lipid vesicles containing actinomycin D 300 microgram/kg IP; group D (eight animals) received a mixture of free actinomycin D 300 microgram/kg and empty lipid vesicles IP. The median survival of group A was 32 days, of group B 30 days, of group C 45.2 days, of group D 54 days, and of group E 42 days. It is suggested that giving the mixture of the drug and the lipid vesicles produces a balance similar to that found in a vesicle solution containing the actinomycin D. It is also suggested that liposomes slow the absorption of actinomycin D from the peritoneum.

Adenocarcinoma↗