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.

Protein-energy malnutrition and anemia in Kivu.

Protein-energy malnutrition in Kivu is associated with a discrete normocytic, normochromic anemia. An attempt to define the physiopathology of this anemia disclosed the following results. As compared with local controls, both iron and total iron binding capacity were low, but with siderophilin saturation and sideroblast counts either normal or elevated; serum and erythrocyte folate was normal, plasma vitamin B12 was normal or elevated, and serum ascorbic acid was normal or elevated. The riboflavin nutritional status was normal. During refeeding, iron and riboflavin deficiencies became apparent. Characteristic findings on admission were the presence of giant erythroblasts and a diminished erythrocyte survival time implicated to an intracorpuscular hemolysis. Two results from the present study could contribute to explanation for the aforementioned abnormalities: low plasma vitamin E levels and, perhaps more importantly, low plasma selenium levels. In conclusion, the anemia of protein-energy malnutrition, as observed in Kivu, is a classifiable nonadaptive anemia that cannot be explained by isolated iron or vitamin deficiencies and whose physiopathology is distinct from that of the anemia of chronic disorders. It is suggested that a selenium deficiency may play an important role in the pathogenesis of this anemia.

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.

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.

Combined therapy for small cell undifferentiated carcinoma of the lung.

Fifty-eight patients with small cell lung cancer were treated from September, 1974, to March, 1976, with combined chemotherapy and radiotherapy. Surgical resection of the lung lesion was performed in three patients, and a number of surgical diagnostic methods were carried out in the remaining patients with unresectable of disseminated lesions. Nineteen patients were from the Veterans Administration Hospital and 39 from Indiana University Medical Center. The median Karnofsky performance status was 60. Thirty-nine patients had extensive disease, and 19 had disease limited to the chest and supraclavicular area. All patients received chest radiotherapy and prophylactic whole brain radiation. Adriamycin, cyclophosphamide, and vincristine were given on day 1 and continued every 3 weeks. There were 27 (48 percent) partial remissions of a median duration of 26 weeks. There were 25 patients (43 percent) with complete remission. The median survival for the entire group was 51 weeks. Six of 58 patients (10 percent) are alive and disease free from 24 to 38 months after treatment. Six of 19 patients with limited disease (32 percent) are presently alive and disease free. This includes one patient in whom surgical resection was performed. Combined therapy influences favorably the prognosis of small cell cancer of the ling, expecially in those patients with limited disease and favorable performance status.

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.

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.

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.

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%.

Erythrocyte glycolysis in protein-energy malnutrition.

Erythrocyte glycolysis has been studied in the anaemia associated with protein-energy malnutrition (PEM) in Kivu. Several results were compatible with a lowering of the mean age of the erythrocyte population, notably raised levels of glucose-6-phosphate, hexokinase, Na+-K+- adenosinetriphosphatases and potassium, and low sodium concentration. Non-significant differences were observed for glucose utilization, lactate formation, and for concentrations of fructose-6-phosphate, fructose-1,6-diphosphate, adenosine diphosphate and pyruvate kinase; there was no gross disturbance of cation transport. The level of adenosine triphosphate was slightly decreased and that of 2,3-bisphosphoglycerate was not elevated, in spite of anaemia. The latter could not be explained by an instability of this metabolite. It is concluded that slight erythrocyte glycolytic abnormalities may occur in the anaemia of Kivu PEM, but that they are not the main cause of the haemolysis observed in this syndrome.

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.

[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]. / Pouvoir antiseptique de la salive et métabolisme de l'oxygène activé dans les neutrophiles: comparaison de deux systèmes enzymatiques bactéricides et de leur comportement en milieu acide.

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.

[Erythrocyte metabolism in vitamin D deficiency rickets]. / Métabolisme érythrocytaire dans le rachitisme carentiel.

In an attempt to explain the hemolysis observed in vitamin D deficiency rickets in the infant, we studied erythrocytic glycolysis, the level of ATP and some of the key enzymes of the glycolytic pathway. This study was performed in one group of vitamin D deficient infants and in one control group. The values obtained in these two groups did not differ significantly. In the absence of a defect in the glycolytic pathway, we suggest that an anomaly exists in the red cell membrane of these patients.