Composite reflective/absorptive IR-blocking filters embedded in metamaterial antireflection-coated silicon.

Infrared (IR)-blocking filters are crucial for controlling the radiative loading on cryogenic systems and for optimizing the sensitivity of bolometric detectors in the far-IR. We present a new IR filter approach based on a combination of patterned frequency-selective structures on silicon and a thin (25-75 µm thick) absorptive composite based on powdered reststrahlen absorbing materials. For a 300 K blackbody, this combination reflects ∼50% of the incoming light and blocks >99.8% of the total power with negligible thermal gradients and excellent low-frequency transmission. This allows a reduction in the IR thermal loading to negligible levels in a single cold filter. These composite filters are fabricated on silicon substrates, which provide excellent thermal transport laterally through the filter and ensure that the entire area of the absorptive filter stays near the bath temperature. A metamaterial antireflection coating cut into these substrates reduces in-band reflections to below 1%, and the in-band absorption of the powder mix is below 1% for signal bands below 750 GHz. This type of filter can be directly incorporated into silicon refractive optical elements.

Cisplatin, vinblastine, and hydrazine sulfate in advanced, non-small-cell lung cancer: a randomized placebo-controlled, double-blind phase III study of the Cancer and Leukemia Group B.

PURPOSE: To assess the chemotherapy regimen of cisplatin, vinblastine, and hydrazine sulfate administered to patients with non-small-cell lung cancer (NSCLC) in a randomized, placebo-controlled double-blind phase III study. PATIENTS AND METHODS: Between July 25, 1989 and February 1, 1991, 291 patients with stage IIIB or IV NSCLC and performance status 0 or 1 were randomized to receive cisplatin 100 mg/m2 intravenously (IV) every 28 days, vinblastine 5 mg/m2 IV per week times five, then every 2 weeks; and either hydrazine sulfate 60 mg three times per day orally or placebo. The concurrent use of corticosteroids, medroxyprogesterone, or other appetite stimulants was not permitted. Treatment groups were comparable for known prognostic variables. The primary end point of this study was survival; however, the influence of hydrazine sulfate on nutritional status, performance status, and quality of life was also assessed. RESULTS: Analysis of 266 eligible patients showed a median survival duration of 7.78 months for the hydrazine sulfate-treated group compared with 7.70 months for the placebo-treated group (P = .65, log-rank). Objective response rates were similar for the two groups, with 4% complete responses, 20% partial responses, and 2% regressions in those treated with hydrazine sulfate; 3% complete responses, 23% partial responses, and 2% regressions in those who received placebo. The major toxicity was severe or life-threatening neutropenia, which occurred in 65% of hydrazine sulfate patients and 63% of placebo patients. There were no differences noted between the two groups in degree of anorexia, weight gain or loss, or overall nutritional status. Sensory and motor neuropathy occurred significantly more often in patients treated with hydrazine sulfate. Quality of life was significantly worse in patients who received hydrazine sulfate. CONCLUSION: This study suggests no benefit from the addition of hydrazine sulfate to an effective cytotoxic regimen.

Soluble macrophage factors trigger apoptosis in cultured hippocampal neurons.

It is not clear whether macrophages which can phagocytose dead cells, may also contribute to death of potentially viable neurons when they enter brain lesion sites after insult. We have initially examined the effects of macrophage-conditioned medium on the integrity of hippocampal neurons in culture. We assessed qualitative and quantitative changes in neuronal status in terms of nuclear morphology, internucleosomal cleavage, cell membrane integrity and process density. Cell morphology with manual counts to quantitate findings showed that macrophage conditioned medium significantly increased the percentage of neurons with abnormal nuclei. Aurintricarboxylic acid attenuated this effect. Demonstration of laddering of DNA on agarose gels suggested an apoptosis-like event. A commercially available kit used to detect high concentrations of 3'-OH DNA ends showed marked increase in labelled cells. These combined findings confirmed that apoptosis was the main event triggered by conditioned medium. Although the number of cells with incompetent membranes also increased with conditioned medium application the majority of cells with apoptotic nuclei maintained membrane integrity. Conditioned medium also resulted in significant loss of cell processes. Conditioned medium from stimulated microglia showed a similar pattern of injury. The response of stressed neurons to conditioned medium was also tested. Exposure of cultures to mild hypoxia resulted in injury but did not significantly alter their subsequent vulnerability to macrophage-conditioned medium. Early experiments suggest that the documented changes in neuronal status are caused by relatively large and stable secreted macrophage proteins.

The sonographic fat/muscle ratio.

A wide variety of biochemical and morphometric parameters have been applied to estimation of nutritional status. A-mode ultrasound has been used to estimate subcutaneous fat thickness in humans; similar studies are reported in the veterinary literature. We applied B-mode ultrasonography to the triceps region of the nondominant arm. Subcutaneous fat and triceps muscle thickness were measured and the ratio of fat to muscle calculated.

Preoperative and postoperative assessment of nutrient intakes in patients who have undergone gastric bypass surgery.

The study of 25 morbidly obese patients who had undergone gastric bypass surgery was undertaken to determine the fat, carbohydrate (CHO), protein, and total caloric intake before and at 1, 3, 6, and 12 months postoperatively. No postoperative complications occurred, and all patients lost weight appropriately. The nutrient intakes were estimated from dietary recall. Dramatic decreases occurred in average total caloric intake from a preoperative value of 3979.4 to 351.6 kcal at 1 month, 471.3 kcal at 3 months, 932.7 kcal at 6 months, and 1091 kcal at 12 months. Fat, CHO, and protein intake decreased equally until 12 months when fat intake had reached a plateau while CHO and protein intake continued to rise. Weight reduction after gastric bypass surgery is related to decreased caloric intake, predominantly in the fat component.

Carboplatin in malignant mesothelioma: a phase II study of the Cancer and Leukemia Group B.

Carboplatin (400 mg/m2) was given at 28-day intervals to 41 patients with malignant mesothelioma. In all, 40 patients were eligible and evaluable for response. Partial responses were seen in 2 cases (5%); regression of evaluable disease, in 1 patient (2%); and stable disease, in 19 subjects (48%). A median of two doses of carboplatin per patient resulted in mild toxicity. Leukopenia (less than or equal to 2,000 cells/microliters) and thrombocytopenia (less than 100,000 cells/microliters) were seen in only 6% and 20% of the patients, respectively. Median survival from study entry was estimated at 7.1 months, with a 1-year survival of 25% +/- 7%. Carboplatin given at a dose of 400 mg/m2 at 28-day intervals shows minor activity against malignant mesothelioma.

Intensive etoposide and carboplatin chemotherapy for advanced non-small-cell lung cancer. A phase II trial of the Cancer and Leukemia Group B.

From April 2 to July 9, 1989, Cancer and Leukemia Group B (CALGB) conducted a Phase II study of etoposide and carboplatin in advanced (AJC Stage IIIb-IV) non-small-cell lung cancer (NSCLC) patients whose performance status (PS) was 0-2. The combination was given at the maximum tolerated dose as defined in a prior CALGB study. Of 76 eligible patients with follow-up data, complete responses were achieved in three patients (4%) and partial responses, in five patients (7%). One patient (1%) with evaluable disease showed improvement. There was only one partial response in the PS 2 patients. Performance status was a predictive factor for response or improvement (p = 0.0368). A high incidence (74%) of severe or life-threatening hematologic toxicity and fatal sepsis in four patients was a reflection of the intensity of the chemotherapeutic regime. The median survival from study entry was 7.4 months. Thirty-seven percent of the patients survived beyond 1 year; the median survival for the PS 0-1 patients was 11.7 months for the PS 2 patients, 4.1 months. Median time to treatment failure was 3.9 months, but treatment had not failed in 9% of the patients after 1 year, all of whom were PS 0-1 at time of study entry. Although the response rate with this dose-intensive chemotherapy regimen was disappointing, the median survival of PS 0-1 patients was equivalent to that of Stage III NSCLC patients in prior CALGB studies. In patients with NSCLC who are treated with chemotherapy, PS may be as important a prognostic factor as stage, when median survival is used as an endpoint.

Filling the gaps in stop-loss insurance.

Stop-loss insurance can provide protection from catastrophic medical claims for self-insured companies: But buyer beware.

Neurotoxicity of soluble macrophage products in vitro--influence of dexamethasone.

When macrophage conditioned medium is added to neurons in vitro, there is a loss of cell membrane integrity, a loss of cell processes, and a large increase in apoptotic neurons. We tested the influence of a potent anti-inflammatory steroid on the interaction between macrophages and neurons. Dexamethasone was applied to macrophages in culture for 24 h while the culture was stimulated with lipopolysaccharide and hypoxia. Conditioned medium was collected after dexamethasone was removed. The dexamethasone pretreated medium was not toxic to hippocampal neurons in contrast to medium from stimulated macrophages not treated with steroid. The dexamethasone effect was concentration dependent. Pretreatment of macrophages with indomethacin and transforming growth factor beta had similar but less impressive effects when compared to dexamethasone. The effect of dexamethasone may have been mediated by inhibiting the synthesis or release of neurotoxic macrophage protein(s), as a combination of medium from steroid pretreated macrophages with medium from nontreated macrophages was not neuroprotective. The toxin(s) did not appear to be tumor necrosis factor alpha or arginase. A role for most neutral proteases was also excluded. We also assessed the consequence of stressing neurons with a mild hypoxic exposure immediately prior to conditioned medium application. Medium from dexamethasone-treated macrophages did not exaggerate hypoxic neuronal injury, unlike medium from non-dexamethasone-treated macrophages. It did not, however, block the exaggerating effect when coapplied in equal volume with medium from nontreated macrophages. Dexamethasone at 100 nM had no impact when applied directly to neurons while they were being exposed to conditioned medium. This in vitro protection by dexamethasone may be relevant to the demonstrated benefit of glucocorticoids in selected brain and spinal cord conditions. Suspicion of a potential link between this in vitro finding and in vivo CNS injury justifies an assessment of more specific agents acting on macrophage protein synthesis or secretion.

Intravenous 6-thioguanine or cisplatin, fluorouracil and leucovorin for advanced non-small cell lung cancer: a randomized phase II study of the cancer and leukemia group B.

This randomized phase II study was designed to evaluate the activity of intravenous 6-thioguanine (6-TG) as a single agent and the combination of cisplatin and 5-fluorouracil (5-Fu) modulated by oral leucovorin (PFL) in patients with advanced non-small cell lung cancer (NSCLC). Eligible patients had measurable or evaluable stage III B or IV NSCLC, had no received prior chemotherapy and had a performance status of 0-2. Patients were randomized to treatment with intravenous 6-TG at 55 mg/m2 administered over 30 minutes for 5 consecutive days and repeated every 35 days, or PFL chemotherapy with cisplatin 100 mg/m2 on day 1, 5-FU 800 mg/m2/day as a continuous intravenous infusion over 5 days and oral leucovorin administered at 100 mg every 4 hours during the entire duration of the cisplatin and 5-FU infusions. PFL was repeated every three weeks. Ninety-five eligible patients were randomized, 46 to 6-TG and 49 to PFL. Response rates were 4% for 6-TG (95% confidence interval 0.5%-14.8%, 1 partial, and 1 complete response) and 29% (16.6%-43.3%) for PFL (all partial). The median time to treatment failure was 2 and 4 months, respectively, and the median survival times were 6 and 10 months, respectively. Toxicities with 6-TG were, generally, mild to moderate but severe or life-threatening granulocytopenia was observed in 21% of patients. With PFL, mucositis was dose-limiting, and 78% of patients had severe or life-threatening mucositis. This led to dose reduction of 5-FU and leucovorin during subsequent cycles or treatment termination in 82% of patients.(ABSTRACT TRUNCATED AT 250 WORDS)