High-brightness white-light source based on up-conversion phosphors

We report the implementation of a new, high brightness, high efficiency white-light source based on up-conversion phosphors. Up-conversion materials absorb near infrared light and re-emit in red, green, and blue. It is possible to combine these colors to create a white-light source. Such a source has the same appealing characteristics as those reported for up-conversion displays: very high brightness operation without damage to the emitters, long lifetimes, and efficiencies comparable to those of existing technologies. In addition, they offer simplicity of fabrication and a variety of operating modes. Here we demonstrate a 7-lm/W D65 white light emitter yielding 2 kcd/m/sup 2/ on a simple diffuser.     

Screening for gestational diabetes: who? How?

Despite many international conferences, there is no consensus on gestational diabetes mellitus and many groups only screen those women who present risk factors or who present during pregnancy complications attributable to this condition. Nevertheless, complications secondary to gestational diabetes are equally frequent whether the mother presents risk factor or not, and these risk factors are only present in 30 to 45% of gestational diabetes. Therefore, all pregnant women should be screened ... or none at all. The type of screening test to be used is just as controversial. The test proposed by the WHO alone allows screening and diagnosing simultaneously, but the cut-off value at 7.8 millimoles for post-charge glycemia seems to be too low for a pregnant woman, at the end of the second trimester. The real question of whether screening for and treating gestational diabetes will actually decrease perinatal morbidity and long-term complications for the mother and the infant cannot be answered as of yet. A large prospective study would be needed, including a control group that would not be treated despite pathological glucose levels, which is ethically inconceivable.     

Non-surgical prevention of uterine cancer

Non surgical prevention of uterine cervical cancer relies on regular performance of Pap smears and colposcopy. Screening for cervical dysplasia allows their treatment by laser vaporisation or cone biopsy, according to their grade, and therefore the prevention of invasive carcinoma. Unfortunately, 40% of the female population does not comply to cervical screening and Pap smears entail 20% false negative results. Prevention of endometrial carcinoma is even far more difficult in that endometrial smears are seldom practised. Periodic surveillance of women receiving oestrogenic hormonal therapy, addition of progesterone in order to eventually protect the endometrium, hysteroscopic detection of irregular endometrial hyperplasia, represent the only tools available today.     

Control of cardiac output in essential hypertension

We reviewed 179 patients who had undergone thoracotomy and resection of a suspected malignant coin lesion of the lung over the past 20 years to see if a policy of early thoracotomy was therapeutically valid. The average diameter of all lesions was 1.6 cm; the average diameter of 27 malignant lesions (15 percent) was 1.8 cm. Follow-up of the 27 patients with malignant neoplasms was 100 percent. The present survival rate of the 19 patients with primary lung cancer is 89 percent (17/19). Of 12 cases of primary lung cancer followed for five years, ten (83 percent) survived. The five-year survival of the eight patients with metastatic lesions was 25 percent (2/8). There were no postoperative deaths and few serious postoperative complications (four patients or 2 percent). Very small primary lung cancers detected and treated early do have the same poor prognosis as larger primary cancers.     

Use of granisetron in patients refractory to previous treatment with antiemetics

Since a high tissue penetration of dirithromycin (D) has been assessed in early studies, the aims of this study were to determine D concentrations in bronchial mucosa and secretions in patients suffering from an acute exacerbation of chronic bronchitis (AECB), to compare intra-individual bronchial mucosa and secretion concentrations and to relate bronchial concentrations of D and clinical efficacy. The main inclusion criteria were comprised of (1) AECB, defined by the presence of an increase in dyspnea, sputum production and change in sputum purulence, and (2) clinical indication of fiberoptic bronchoscopy allowing performance of bronchial biopsies. All patients were treated with a 500-mg once-daily D dose for 5 days. Patients were randomly divided into three groups, according to sampling times (24, 48 and 72 h after the last dose). Tissue concentration analyses were performed by one blinded microbiologist (microbiological agar diffusion assay). The results showed: (1) 37 out of the 46 patients (80.4%) had a favorable response to treatment at the time of fiberoptic bronchoscopy (14 cured, 23 improved); (2) bronchial mucosa concentrations were high in all groups, and (3) mean values at 24, 48 and 72 h after the last dose were respectively 6.51 +/- 1.44, 6. 61 +/- 2.7, 5.67 +/- 1.02 mg.kg-1; no statistical difference was observed between the groups. In bronchial secretions collected simultaneously, concentrations were lower, i.e. 1.26 +/- 0.3, 0.61 +/- 0.12, 0.84 +/- 0.12. Significant associations were observed between bronchial mucosa and secretion concentrations (r = 0.71, p = 0.0001), and between clinical response and bronchial concentrations (p = 0.03, Kruskall-Wallis test). In conclusion, these results may confirm the clinical significance of tissue concentrations measured in bronchial tissues of patients with AECB.     

The renin-angiotensin-aldosterone system in hypertensive subjects. I-Analytical study of 124 patients (author's transl)

An analytical study of the renin-angiotensin-aldosterone system was made in 124 individuals with essential hypertension, aged from 25 to 55 years. The results obtained, with rigorous control to posture and sodium balance, indicate the existence of a number of subgroups of hypertensive subjects related to their renin activity and plasma aldosterone in the upright position. This classification thus makes possible comparison with patients suffering from secondary hypertension.     

Problems in practical management of essential hypertension

A study of 100 men with arterial hypertension showed that: 1) hypertension was predominantly moderate with 14% index of placebo reactivity; 2) only 3 patients had a surgically curable etiologic factor; 3) frequent associated findings were hereditary factors (60%), overweight and metabolic disorders (30 to 40%). Such results suggest that: a) hypertension could be treated, in the majority of patients, without preliminary etiologic investigations and, b) non invasive hemodynamics techniques are required to evaluate arterial and cardiac lesions which are the dominant factors in the prognosis.     

Embryotoxic factors and recurrent spontaneous abortions]

The contributions of amino acids to the overall osmotic activity of cyst fluids were sought in this comparative study of fluids from the cysts of autosomal dominant polycystic disease (ADPKD) and gross cystic disease of the breast (GCDB). Fluids (n = 18) from 18 women with GCDB and from 8 patients with ADPKD (n = 25), grouped on the basis of sodium concentrations, were analyzed for potassium, chloride, protein, and osmolality by routine methods and for amino acids by reversed-phase high-pressure liquid chromatography. Similarities between kidney and breast cyst fluids included relative isosmolality, a wide range of sodium concentrations, an inverse relationship between sodium and potassium concentrations, higher concentrations of amino acids in low-sodium fluids, and significant correlations between sequential concentrations of amino acids in cyst fluids versus blood and some of its components. Therefore, cyst fluids in ADPKD and GCDB share compositional characteristics, and amino acids, possibly of blood protein origin, accumulate in small but osmotically significant amounts in some, particularly low-sodium, cysts of kidney and breast.