Design of metallic nanoparticle gratings for filtering properties in the visible spectrum.

Plasmonic resonances in metallic nanoparticles are exploited to create efficient optical filtering functions. A finite element method is used to model metallic nanoparticle gratings. The accuracy of this method is shown by comparing numerical results with measurements on a two-dimensional grating of gold nanocylinders with an elliptic cross section. A parametric analysis is then performed in order to design efficient filters with polarization dependent properties together with high transparency over the visible range. The behavior of nanoparticle gratings is also modeled using the Maxwell-Garnett homogenization theory and analyzed by comparison with the diffraction of a single nanoparticle. The proposed structures are intended to be included in optical systems that could find innovative applications.

Photo-chemical study and optical properties of microtips self- written on vertical laser diodes using NIR photo-polymerization.

Near infra-red (NIR) self-guided photo-polymerization is investigated in the context of micro-optics photo-fabrication on VCSELs (Vertical-Cavity Surface Emitting Lasers). We present the optimized process we have developed to allow for a collective fabrication on III-V devices wafers under real-time optical monitoring. The influence of photo-chemical parameters on final micro-elements dimensions is studied for two types of single mode 760 nm VCSELs. The difference of the resulting tip shape between the two lasers is due to the strong differences of their emissions, as they are nicely reproduced by the computed near-field profiles. The tip shapes are also compared to those produced by the light emitted by an optical fiber and differences with VCSEL tips are discussed. Also the VCSEL characteristics with fabricated tips are discussed and found in good agreement with optical modeling.

Emphysematous pyelonephritis related to specific gas-forming Escherichia coli without diabetes mellitus.

A 60-year-old-man without a history of diabetes mellitus, or invasive manipulation or obstruction of the urinary tract was admitted for septic shock. Type I emphysematous pyelonephritis was clear in this case: gas within the renal parenchyma extending into the subcapsular region and the perirenal space was present on spiral computerised tomography (CT). Surgical nephrectomy was performed because biochemistry, urography and CT identified a damaged non-functioning left kidney. The outcome was favourable. All urine, blood and nephrectomy specimen cultures were positive for a specific Escherichia coli which produced a high level of gas compared to a reference E. coli strain in the same standard medium, despite the absence of diabetes mellitus. Certain strains of bacteria are able to produce high levels of nitrogen, carbon dioxide and hydrogen and such fermentation in the absence of a high glucose serum level might explain the acute gas-producing bacterial renal infection.

Two-hour versus six-hour administration of amphotericin B in the treatment of kala-azar.

In a randomised study, 50 parasitologically confirmed cases of kala-azar were allocated to two treatment groups: group A received amphotericin B in 5% glucose infusion for 6 h and group B for 2 h. Amphotericin B was given at an initial dosage of 0.05 mg/kg body weight, increasing to 1 mg/kg body weight on day 5, and this dose was given daily until patients had received a total of 20 mg/kg body weight. Toxicities like rise in serum creatinine, fall in serum potassium levels and diminution in appetite were no different in the two groups. There was no difference in clinical, parasitological and ultimate cures between the two groups. Man-hours spent in treating patients in the 2-h infusion group were one-third of the time with the 6-h infusion group. It was concluded that 2-h infusion of amphotericin B caused fewer infusion-related toxicities (shivering and fever) and saved time spent in treating patients; hence it should be recommended for use.

The treatment of kala-azar during pregnancy.

BACKGROUND: Kala-azar in pregnant women is difficult to treat because for them the two commonly used drugs, sodium stibogluconate and pentamidine, are not considered safe. We assessed the effect of amphotericin B on pregnancy, on the foetus and kala-azar. METHODS: Five pregnant women were administered amphotericin B at a dose of 1 mg/kg body weight daily starting with 0.5 mg/kg body weight till a total dose of 20 mg/kg body weight was given. The progress of pregnancy was monitored ultrasonographically and the mothers and children were followed for six months. RESULTS: All the 5 women were cured of the disease and there was no harmful effect on the children. CONCLUSION: Amphotericin B cures kala-azar during pregnancy with no harmful effects on the foetus.

Amphotericin B in resistant kala-azar in Bihar.

BACKGROUND: During the recent epidemic of kala-azar in Bihar, we identified a group of patients who were unresponsive to the two commonly used drugs--sodium stibogluconate and pentamidine. We evaluated the use of amphotericin B in these patients because it has been shown to be active in experimental animals against amastigotes and promastigotes, it has been found to be useful in South American patients and is now recommended by the World Health Organization as a second line drug. METHODS: We selected 300 patients who were unresponsive to sodium stibogluconate and pentamidine (out of 500 patients with kala-azar confirmed by demonstration of Leishmania donovani bodies in their splenic aspirates). Amphotericin B was given in a dose of 1 mg/kg body weight on alternate days starting with 0.05 mg/kg body weight with daily increments till a 1 mg dose was reached. A total dose of 20 mg/kg was given initially and repeated if the parasites persisted. The investigations done before and after treatment were splenic or bone marrow aspiration, measurement of the spleen and liver size, body weight, total and differential white cell counts, haemoglobin level, total serum protein, blood urea, serum creatinine, serum potassium, blood sugar, serum alanine and aspartate transaminase, electrocardiography and a chest X-ray. The efficacy of treatment was assessed at the end of treatment and after 6 months of follow up. RESULTS: After treatment with amphotericin B, 298 (99%) of the patients had been cured of their disease as evidenced by the disappearance of fever, reduction of hepatosplenomegaly, clearance of the parasites from the spleen and bone marrow and an absence of relapse on 6 months of follow up. Two hundred and sixty-eight (89%) patients required 1 g of the drug, 24 (8%) required 1.5 g and 6 (2%) required 2 g. All patients had shivering and fever during the infusion. Two had a cardiac arrest from which they could not be revived. Other complications included anorexia, stomatitis, jaundice, hypokalaemia and a rise in blood urea. However, these were only mild and improved after treatment was stopped. CONCLUSION: Amphotericin B is an effective drug for patients with kala-azar unresponsive to treatment with sodium stibogluconate and pentamidine, but it should be administered under close medical supervision.

Efficacy of amphotericin B in multi-drug resistant kala-azar in children in first decade of life.

Fifty children in the first decade of life, and suffering from multiple drug resistant kala-azar, confirmed by demonstration of amastigotes in aspirates of bone marrow or spleen were treated with amphotericin B in gradually increasing dosage to a total dose of 20 mg/kg. All patients had classical features of severe kala-azar, and had taken more than one course of antimony and pentamidine, and three patients had taken one additional course of ketoconazole besides many courses of antimony and pentamidine. The clinical response started just after first infusion in 8 patients, and the patients became afebrile. By 5th infusion, all looked better and 18 patients became afebrile. By 15th infusion all patients were afebrile and cheerful. Their spleens became smaller and body weights and total white cell counts increased. Forty eight patients had parasitological cure at the end of treatment, and only 2 patients required an additional 5 infusions for parasitological cure. All patients were ultimately cured. No one relapsed within six months of follow up. All patients had shivering, rigor and rise of temperature on the day of infusion, which could be minimized with prior administration of low dose of hydrocortisone, but could not be eliminated. Eighteen patients had loose motions during treatment, while 14 patients had decrease in appetite which improved quickly when the treatment was over. Fourteen patients had transient rise of blood urea, in six patients serum creatinine also increased and 16 patients had a minor fall in serum potassium.(ABSTRACT TRUNCATED AT 250 WORDS)

[Classification and treatment of ureteroceles in the adult]. / Classification et traitement des urétérocèles de l'adulte.

Ureterocele or congenital pseudocystic dilatation of the terminal portion of the ureter due to persistence of Chwalla's membrane is frequent in female adults (17-35%) in its orthotopic form. It expands the short submucosal segment of the normally situated ureter and may be intravesical or extravesical. The diagnosis is primarily radiological based on intravenous urography (IVU) and endoscopy (urethrocystoscopy). Treatment depends on the site of the ureterocele, the clinical context, associated anomalies and especially the dimensions. Endoscopic treatment has numerous advantages and deserved to be more widely used.

[Ureteral compression by mesenteric desmoid tumor. Report of 2 cases]. / Compressions urétérales par des tumeurs desmoïdes du mésentère. A propos de deux cas.

The authors report two cases of abdominal fibromatosis corresponding to Gardner's syndrome, causing hydronephrosis by extrinsic ureteric compression in young men in whom any form of surgical resection would have been in vain. These cases of ureteric compression were treated endoscopically by placement of a double J ureteric stent associated with treatment by tamoxifen in one case and sulindac in the other, with apparent stabilization of the disease. The two patients are regularly followed in the department with ureteric stent replacement two to three times a year.

Are incremental doses of amphotericin B required for the treatment of visceral leishmaniasis?

One-hundred-and-twenty visceral leishmaniasis patients, all with demonstrable splenic amastigotes after treatment with sodium stibogluconate and pentamidine, were treated with amphotericin B. The patients were allocated into two equal groups matched by age and sex. Patients in one group received amphotericin B in the traditional incremental dose regimen, i.e. 0.05, 0.10, 0.25, 0.50 and 1.0 mg/kg body weight on days 1, 2, 3, 4, and > 4, respectively. Patients in the other group received amphotericin B at a constant 1 mg/kg bodyweight per day from day 1. Each of the 120 patients received a total dose of 20 mg/kg bodyweight. By the end of treatment the incidence of infusion-related toxicities, such as rigor and fever, and of renal toxicities, such as elevated serum creatinine and low serum potassium, was the same in both groups (P > 0.05). The two treatment regimens were also equally effective; every patient was cured and none relapsed within 6 months' follow-up. It is therefore recommended that amphotericin B be given as the full optimal dose (1 mg/kg) from day 1. There seems no advantage in the incremental regimen; not only does it 'waste' 4 days before the optimal dose is reached but it is more expensive and may encourage the development of drug resistance.

Daily versus alternate-day regimen of amphotericin B in the treatment of kala-azar: a randomized comparison.

Using a randomized study, we compared a daily and an alternate-day regimen of amphotericin B for the treatment of kala-azar, with respect to efficacy, adverse reactions, cost-effectiveness, and tolerance. The study subjects were 80 kala-azar patients, drawn from the first four decades of life and matched by age, sex, and parasite load. The patients were randomly allocated to treatment groups A and B (40 patients per group). Patients in group A received a daily regimen of amphotericin B, starting with an escalating dose of 0.05 mg/kg body weight per day until a daily dose of 1 mg/kg was reached; the latter dose was then given daily till a total dose of 20 mg/kg body weight had been administered. The patients in group B also started with an escalating dose of 0.05 mg/kg but when 1 mg/kg was reached the drug was given on alternate days. All 80 patients using the two treatment regimens were cured, no patient relapsed in either group in 6 months of follow-up, and their bone-marrow aspirates were free of amastigotes. Treatment of kala-azar patients with the daily regimen of amphotericin B at a dose 1 mg/kg body weight was as effective, not more toxic, equally well tolerated, and much more cost-effective than the alternate-day regimen and should be adopted for treatment of this condition.

Surgical management of complex renal cysts: a series of 32 cases.

PURPOSE: The differentiation between benign cysts of the kidney and those that require surgical exploration remains difficult. The accuracy of radiological techniques (ultrasound, computerized tomography [CT], angiography, magnetic resonance imaging, cyst puncture and intraoperative pathological examination) is analyzed. MATERIALS AND METHODS: Surgical exploration was performed in 30 patients with 32 asymptomatic renal cysts, and the pathological specimens were compared retrospectively to the radiological findings. The classification of Bosnaik was used to categorize the ultrasound and CT findings. RESULTS: Of our complex renal cysts 41% proved to be malignant. Our results suggest that the radiological techniques are not well suited for characterization of these cysts. None of the Bosnaik types was sufficiently predictive of the lesion. Only a Bosnaik score of 4 (the sum of ultrasound and CT Bosnaik types) was not associated with renal cell carcinoma. According to the radiological findings, 1 patient was under treated (recurrent renal cell carcinoma) and 4 were over treated (radical nephrectomy for benign lesions). CONCLUSIONS: A practical therapeutic strategy is described in which radical nephrectomy is performed when malignant lesions are detected either by preoperative or intraoperative techniques. Conservative surgery is indicated for benign cysts according to the clinical status and risks of nephron sparing surgery.