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Biomedical subjects

I Mandelbaum

Publications and source records attributed to I Mandelbaum.

At least 19 recordsLinked to original sources

Comparative measures of single-wall carbon nanotube dispersion.

Model composites of DNA-wrapped single-wall carbon nanotubes in poly(acrylic acid) are used to evaluate metrics of nanotube dispersion. By varying the pH of the precursor solutions, we introduce a controlled deviation from ideal behavior. On the basis of small-angle neutron scattering, changes in near-infrared fluorescence intensity are strongly correlated with dispersion, while optical absorption spectroscopy and resonant Raman scattering are less definitive. Our results represent the first systematic comparison of currently accepted measures of nanotube dispersion.

Acrylamides↗

Intrapleural therapy for malignant pleural effusions. A randomized comparison of bleomycin and tetracycline.

Between December 1985 and August 1988, there were 115 patients at 13 centers who were entered on a randomized comparison of tetracycline and bleomycin for treatment of malignant pleural effusions. Fifteen patients were not treated, primarily due to rapid progression of systemic cancer. Fifteen patients entered on a high-dose regimen of bleomycin (120 units) were excluded from this analysis (following early closure of that arm), leaving 85 patients randomized to low-dose bleomycin (60 units; 44 patients) or tetracycline (1 g; 41 patients). Patients were required to have a cytologically positive pleural effusion, good performance status (0, 1, or 2), lung reexpansion following tube thoracostomy with drainage rates of 100 ml/24 or less, no prior intrapleural therapy, no prior systemic bleomycin therapy, no chest irradiation, and no recent (four weeks) change in systemic therapy. A total of 11 patients (five with bleomycin and six with tetracycline) were not evaluable due to technical problems with tube drainage (one), loss to follow-up (two), sudden death due to pulmonary embolus (one), and rapid progression of systemic disease (seven). There were no clinically significant differences in demographic factors, primary site, performance status, or presence of metastases other than pleural effusion. Overall survival did not differ between the two groups. Median time to recurrence or progression of the effusion was 32 days for tetracycline-treated patients and at least 46 days for bleomycin-treated patients (p = 0.037). The recurrence rate within 30 days of instillation was 36 percent (10/28) with bleomycin and 67 percent (18/27) with tetracycline (p = 0.023) (not all patients were restudied in the first 30 days). By 90 days the corresponding recurrence rates were 30 percent (11/37) for bleomycin and 53 percent (19/36) for tetracycline (p = 0.047). Toxicity was similar between groups.

Adult↗

[Antiseptic properties of saliva and metabolism of activated oxygen in neutrophils: comparison of the 2 enzymatic bactericidal systems and of their behavior in an acid environment].

Growth control of anaerobes in the oral cavity, is secured--among other means--by: 1) phagocytosis of opsonized bacteria; 2) synthesis of hypothiocyanite by the salivary peroxidase system. The former may be inhibited by bacterial acid byproducts. As for the salivary hypothiocyanite, it proved itself able of hindering in vitro the growth of bacterial strains known as customary periodontal pathogens. Its possible effectiveness in vivo remains however hypothetical in the case of deep gingival pockets according to the poor diffusion there of salivary components.

Anti-Bacterial Agents↗

Postchemotherapy resection of residual tumor in limited stage small cell lung cancer.

To determine the feasibility of post-chemotherapy resection of residual tumor in small cell lung cancer, 24 selected patients with limited-stage disease were evaluated for exploratory thoracotomy. All 24 patients achieved partial or complete clinical response to chemotherapy and were considered adequate medical candidates for surgical resection. Fifteen patients underwent a lobectomy or pneumonectomy, 13 of whom had residual tumor in the resected specimen. Of the nine remaining patients, seven had no tumor found on biopsy at thoracotomy and two had unresectable mediastinal node involvement. No chemotherapy was administered postoperatively in any patient until disease progression or relapse was documented. Median survival for the entire group was 19 months and did not differ according to the surgical procedure performed. Nineteen patients had relapse. Patients undergoing biopsy only recurred locally in six of seven cases a median of five months post-thoracotomy (range one to six months). Two "biopsy only" patients were tumor free at 34+ and 56+ months. Local recurrence was observed in six of 12 resected patients, while six patients experienced only extrathoracic metastases. Median time to recurrence for resected patients was also five months. Four resected patients experienced late recurrence 16 to 36 months postoperatively and were alive with tumor at 29+ to 42+ months. Two resected patients were tumor-free at 13+ and 37+ months. Post-chemotherapy surgical resection was feasible in limited-stage patients and improved local control of disease.

Antineoplastic Agents↗

Teratoma following cisplatin-based combination chemotherapy for nonseminomatous germ cell tumors: a clinicopathological correlation.

From April 1975 through May 1981, 51 patients had teratoma resected from residual disease following cisplatin-based combination chemotherapy. All patients had normal serum markers before resection of abdominal (25), lung (12), mediastinal (5), thoracoabdominal (8) or other (1) disease. Teratoma was classified as mature in 29 cases, immature in 15 or immature with nongerm cell elements in 7. Of the 51 patients 31 (61 per cent) remain free of recurrent disease, while 20 either had recurrent carcinoma (10) or teratoma (10) requiring further therapy. Nine patients died, including 1 in whom angiosarcoma developed, which was thought to be secondary to previous radiation therapy. In 4 patients the initial relapse of carcinoma developed beyond 2 years after resection. Univariate factors predicting for relapse include tumor burden, immature teratoma with nongerm cell elements and site (mediastinum), while only immature teratoma with nongerm cell elements and site predicted for survival. Patients with immature teratoma had a comparable relapse-free and over-all survival as those with mature teratoma. Using a multivariate analysis, primary tumor site at the mediastinum was the most significant adverse factor predictive for relapse and survival. This study appears to support the various pre-clinical models that demonstrate multipotential capabilities of teratoma. Complete surgical excision of teratoma remains the most effective treatment with continued close followup recommended for high risk patients (immature teratoma with nongerm cell elements, large tumor burden and primary mediastinal tumors) with resected teratoma.

Antineoplastic Combined Chemotherapy Protocols↗

Resection of thoracic and abdominal teratoma in patients after cisplatin-based chemotherapy for germ cell tumor. Late results.

Fifty-one patients with primary testicular (N = 46) or mediastinal germ cell cancer (N = 5) were treated from April, 1975, through May, 1981, and had teratoma resected from residual disease after cisplatin-based combination chemotherapy. All patients had normal serum markers before resection of pulmonary (N = 12), mediastinal (N = 5), thoracoabdominal (N = 8), supraclavicular (N = 1) or abdominal disease (N = 25). Teratoma was classified as mature teratoma (N = 29), immature teratoma (N = 15), or immature teratoma with non-germ cell elements (N = 7). Thirty of 51 (60%) patients remain free of recurrent disease, whereas 20 patients have either recurrent carcinoma (N = 10) or teratoma (N = 10). One patient has a presumed second malignancy. After additional chemotherapy, four patients with recurrent carcinoma are alive and disease free and six have died. After an additional operation, eight of 10 patients with recurrent teratoma are long-term survivors. In four patients the initial relapse of carcinoma developed more than 2 years after therapy; in an additional patient carcinoma recurred after a 32 month disease-free survival period. Univariate factors predicting for relapse include tumor burden, immature teratoma with non-germ cell elements, and site (mediastinum), whereas only immature teratoma with non-germ cell elements and site predicted for survival. Immature teratoma and mature teratoma had similar relapse-free intervals and overall survival intervals. According to a multivariate analysis, primary tumor site at the mediastinum is the most significant adverse factor predictive for both relapse and survival (two of five patients survived). This study appears to support the various preclinical models that demonstrate multipotential capabilities of teratoma. Complete surgical excision of teratoma remains the most effective treatment with continued close follow-up recommended for high-risk patients (immature teratoma with non-germ cell elements, large tumor burden, or primary mediastinal tumors.

Abdominal Neoplasms↗

Purine enzyme levels in rheumatoid arthritis.

We studied purine metabolism in rheumatoid arthritis (RA), adenosine deaminase (ADA), 5'-nucleotidase (5'NU) and purine nucleoside phosphorylase (PNP) activities by measuring the circulating mononuclear cells of patients with RA and healthy controls. Patients had significantly lower levels of ADA and 5'NU but not of PNP than controls. The decreases could not be related to age, antiinflammatory therapy, decreased percentages of T cells or imbalance between major T cells subsets. Differences in cell maturation or traffic could account for our observation. Alternatively, abnormalities of purine metabolism are not definitely excluded in RA if the lower enzyme activity is not sufficient to perform the metabolic steps.

5'-Nucleotidase↗

Methylthioadenosine phosphorylase and purine nucleoside phosphorylase in B-chronic lymphocytic leukemia.

Enzymes of purine metabolism have potential utility as biological markers of normal lymphocytes and their neoplastic counterparts. The activity of two of them, methylthioadenosine phosphorylase (MTA phosphorylase) and purine nucleoside phosphorylase (PNP) were measured in peripheral mononuclear cells from 11 patients with B-chronic lymphocytic leukemia (B-CLL) and compared with those obtained in cells from 10 normal volunteers. An inverse relationship between the two phosphorylases was demonstrated in patients, with higher MTA-phosphorylase and lower PNP activities than in control subjects.

Adult↗

The importance of one-stage median sternotomy and retroperitoneal node dissection in disseminated testicular cancer.

More than 350 patients with testicular germ cell cancer have been treated with cisplatin combination chemotherapy. Seventy-two with metastases to the thorax who had operation are discussed here. In a subgroup of 24 patients with additional retroperitoneal disease, a one-stage median sternotomy was performed in 18 patients, and a thoracotomy in 6, with retroperitoneal node dissection. Seventeen patients had similar pathological lesions in the thorax and retroperitoneum; in 7, the lesions differed. There was no operative mortality in the entire group. Overall, chemotherapy altered the metastases to mature teratoma in 28 patients, and 27 are long-term survivors. Among 22 patients with fibrotic, necrotic masses, 19 are long-term survivors; 6 of the 22 with persistent carcinoma had chemotherapy postoperatively and are long-term survivors. The overall cure rate for patients with disseminated testicular cancer is approximately 80%. Among those who had a one-stage thoracoretroperitoneal procedure, long-term survival is 83%; for the entire thoracic surgical group, it is 74%.

Adolescent↗

Fanconi's anaemia. Simultaneous onset in 2 siblings and unusual cytological findings.

Fanconi's anaemia is reported in 2 siblings. The simultaneous onset of pancytopenia after possible exposure to common external agents suggest that both a frail genotype and environmental factors may be etiologically involved in the disorder. One of the children died after having developed a monoblastic leukaemia. This patient disclosed very striking cytological abnormalities, including a dyserythropoietic pattern and ropalocytosis. The physiopathology of the latter abnormality, which has hitherto not been noticed in Fanconi's anaemia, is uncertain.

Adolescent↗

In vitro study of the incorporation and transport of nonesterified fatty acids into the phospholipids of the red blood cell membranes of cystic fibrosis patients.

The in vitro incorporation and transport of plasma nonesterified fatty acids into phospholipids of red cell membranes have been studied in cystic fibrosis and healthy children. Red blood cells were labeled in vitro by an active "acyltransferase"-dependent incorporation of radioactively labeled nonesterified fatty acids. [3H]-Palmitic and [14C]-linoleic acid, bound to albumin, have been studied simultaneously because it has been shown before that the concentration of palmitic acid increases and the concentration of linoleic acid decreases both in the plasma nonesterified fatty acid fraction and in the various phospholipids of the erythrocyte membranes of cystic fibrosis patients. The labeled cells were reincubated in autologous serum and the radioactivity present in the serum lipids and in the major phospholipid fractions of the erythrocyte membranes was measured. A general conclusion is that the in vitro turnover of labeled palmitic and linoleic acids in the phospholipids of the erythrocyte membranes is higher for cystic fibrosis patients than for healthy children. No difference is detectable between the in vitro behaviour of [14C]-linoleic versus [3H]-palmitic acid in cystic fibrosis patients compared with healthy children.

Biological Transport↗

Oxidative haemolysis in protein malnutrition.

A study of the haemolytic anaemia observed in protein-energy malnutrition (PEM) in Kivu disclosed the following results. The in vitro resistance to oxidative aggressions of PEM patients' erythrocytes was decreased: when incubated with acetylphenylhydrazine, a higher percentage of the cells showed Heinz bodies, as compared with erythrocytes of local controls. Normal or increased activities were found for certain erythrocyte enzymes involved in the detoxification of activated oxygen: glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and glutathione reductase. The level of reduced glutathione was not decreased. Reduced activities were observed for two enzymes containing trace elements: glutathione peroxidase and superoxide dismutase. It is suggested that the shortened erythrocyte lifespan observed in PEM patients corresponds to an oxidative process which results from the decrease of both enzyme activities. The hypothesis that depletion of trace elements could be responsible for the decreased activity of those enzymes is discussed.

Adolescent↗

Surgical resection in disseminated testicular cancer following chemotherapeutic cytoreduction.

Platinum combination chemotherapy will regularly produce a 70% complete response rate in testicular cancer. Many patients failing to achieve complete remission can still be rendered disease-free with surgical resection of residual localized disease. Twenty-one patients underwent resection for residual pulmonary lesions and 41 underwent lymphadenectomy for persistent retroperitoneal disease. There were no characteristic radiographic findings for fibrous tissue versus mature teratoma versus carcinoma. Although elevated HCG or AFP levels indicated the presence of carcinoma, negative HCG and AFP did not rule out such a diagnosis as 12 of 22 resected carcinoma patients were seronegative. Of 35 patients, 31 (89%) with fibrous tissue or mature teratomas and all four patients with immature teratomas have been continuously free of disease with a minimal postoperative follow-up time of six months. However, only two of 22 patients with resected carcinomas have been continuously disease-free. Post-operative chemotherapy for mature teratoma or fibrous tissue is probably not necessary. However, we feel that further aggressive chemotherapy is needed in the resected carcinoma patient with at least two courses of platinum combination chemotherapy. Surgical resection of residual disease following chemotherapy-induced cytoreduction with platinum combination chemotherapy may be therapeutic in some cases and helps to define the optimal subsequent treatment strategy.

Antineoplastic Agents↗

Surgical treatment and course of pulmonary pseudotumor (plasma cell granuloma).

A number of benign clinical conditions of the lung may simulate carcinoma. Pulmonary pseudotumor, which falls into this category, may present as a mass lesion or rarely as an infiltrate. This paper describes six patients with pulmonary pseudotumor, their surgical treatment and, for the first time, a postoperative follow-up ranging from 1 to 10 years. Histories of heavy cigarette smoking were obtained in four. Discrete masses on x-ray films were present in five, and one had localized infiltrates. Lobectomy was performed in two and partial mass resection or removal of tissue for biopsy in four. In this latter group, postoperative x-ray films from 1 to 10 years later showed complete disappearance of the lesions. No subsequent malignant lesion developed, and there was no early or late mortality. This unique experience documents for the first time the natural course of pulmonary pseudotumor. On the basis of this and isolated reports in the literature, pseudotumor must be carefully differentiated from carcinoma. Once diagnosed, as minimal lung resection as possible is indicated.

Adult↗

Aggressive surgical management of testicular carcinoma metastatic to lungs and mediastinum.

During the past six years, more than 200 patients were treated with chemotherapy for disseminated testicular cancer with a 70% complete remission rate. In 22 patients who were 17 to 46 years old, there was persistent thoracic disease, which was treated surgically. Six required a median sternotomy for bilateral pulmonary involvement or mediastinal metastasis. In 8 patients, chemotherapy had altered the histological appearance of the metastases from that of an undifferentiated primary tumor to a mature cystic teratoma. Five patients had nodules in the lungs, which were necrotic and fibrosed with no evidence of tumor. Nine showed embryonal cell carcinoma metastases in the lungs. All who had cystic teratoma are alive and free from disease. Three of the 5 with nodules and 1 of the 9 with metastases are currently free from disease. Agressive surgical intervention is important in this unique group of patients in order to determine the precise pathological category of the lesions, to remove intrathoracic malignancy, and to assess the need for additional chemotherapy. An operative mortality of zero and a low morbidity justify this approach.

Adolescent↗