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Biomedical subjects

R M Martinez

Publications and source records attributed to R M Martinez.

At least 19 recordsLinked to original sources
PubMed1999

Managed care in three states: experiences of low-income African Americans and Hispanics.

This article examines the experiences of low-income, nonelderly Hispanics, African Americans, and whites in managed care (MC), and compares them to their racial/ethnic counterparts enrolled in fee-for-service (FFS) health plans. Survey findings from Florida, Tennessee, and Texas show that MC and FFS enrollees do not differ substantially on most access and satisfaction measures, with a few notable exceptions. When compared with their FFS counterparts, African-American MC enrollees are twice as likely to report problems in obtaining needed care, and Hispanic MC enrollees are nearly twice as likely to rate the extent to which their providers care about them as "fair" or "poor." In contrast, whites in MC are less likely to be without a regular provider than their FFS counterparts, but report greater dissatisfaction with the extent to which providers care about them.

Black or African American↗
PubMed1998

Salidiuretic action by genistein in the isolated, perfused rat kidney.

The urinary isoflavonoid genistein inhibits membrane Na-K-Cl cotransporters at similar concentrations as furosemide, but the significance of this action is unknown. Genistein was therefore investigated in rats for its potential salidiuretic actions. In the isolated, perfused rat kidney, genistein induced a maximal salidiuretic action similar to that of furosemide but was 3 to 5 times less potent than furosemide in terms of active doses (natriuresis EC50, 237+/-92 versus 56+/-20 micromol/L for genistein and furosemide, respectively). Genistein and furosemide had no additive salidiuretic actions. Genistein had no significant effect on glomerular filtration rate but was able to significantly reduce renal vascular resistance with respect to vehicle isolated perfused kidney. Indomethacin (10 micromol/L), a blocker of prostaglandin biosynthesis, reduced salidiuresis and renal vasorelaxation by genistein. Subcutaneous genistein (15 mg/kg) induced a statistically significant increase in diuresis and natriuresis with respect to vehicle during the first 6 hours of administration in rats. In conclusion, genistein compares well with furosemide in vitro for its salidiuretic profile and potency in the isolated perfused rat kidney and is also natriuretic by the subcutaneous route in the rat. Further studies are required to investigate potential natriuretic and perhaps hypotensive actions of dietary genistein.

Animals↗
PubMed1998

Public health departments adapt to Medicaid managed care.

Millions of Medicaid beneficiaries have recently moved into private managed care plans across the country. Public health departments--which have acted as providers of primary care and other services for some Medicaid patients--are often not explicitly included in contracts between these designated Medicaid plans and the states. As a result, many of the 3,000 city and county public health agencies nationwide have lost both patients and significant revenue to plans. This Issue Brief describes how public health departments are adapting to this shift in state policy. According to our research conducted in 1997, many are de-emphasizing the delivery of direct health care services in favor of core public health functions, such as investigating community health problems and health promotion. Some are initiating new partnerships with Medicaid managed care plans.

Health Policy↗
PubMed1997

Renal and vascular actions of equol in the rat.

BACKGROUND: The urinary isoflavonoid equol inhibits membrane Na-K-Cl cotransporters at similar concentrations to those at which furosemide inhibits them, but the significance of this action is not known. OBJECTIVE: To investigate the potential salidiuretic and vascular actions of equol in the rat. METHODS: Renal functioning was assessed in vitro in the isolated perfused kidney and in vivo in conscious rats. The vascular contractility of isolated aorta was assessed. RESULTS: In the isolated perfused kidney equol was concentrated 50- to 70-fold in the urinary fluid, it was 3-4 times less potent than furosemide at increasing diuresis, natriuresis and kaliuresis (the difference was due to its higher protein-binding affinity), and it induced a modest but significant increase in glomerular filtration rate. In vivo, orally administered equol was a modest natriuretic agent, about 8-fold less potent than orally administered furosemide (in molar terms). In isolated aortic rings precontracted by administration of phenylephrine, administration of equol relaxed the contracted aorta at 10-fold lower concentrations (concentration for half-maximal activity 58.9 +/- 16 micromol/l, n = 3) than did furosemide (concentration for half-maximal activity 633 +/- 145 micromol/l, n = 3). CONCLUSIONS: Equol is a modest natriuretic and vasorelaxant agent in the rat. Further studies are required in order to investigate the potential natriuretic and perhaps hypotensive actions of dietary equol precursors (daidzein).

Animals↗
PubMed1996

Purification and chemical characterization of a potent inhibitor of the Na-K-Cl cotransport system in rat urine.

A potent inhibitor of the Na-K-Cl cotransport system was purified from urines of salt-loaded rats. Mass spectroscopy revealed a molecular mass of 242 Da. Nuclear magnetic resonance showed a spectrum identical to that of 3,4-dihydro-3-(4-hydroxyphenyl)-2H-1-benzopyran-7-ol (an "estrogen-like" isoflavonoid: equol). This compound inhibited cotransport fluxes at similar concentrations (IC50=16-24 microM) as furosemide (IC50 approximately 10 microM). Cotransport inhibitory activity of urines from rats drinking tap water was fully explained by urinary equol concentrations (approximately 27 microM, measured by high-performance liquid chromatography). Slat-loading increased urinary equol excretion, but not sufficiently high to fully explain the very important increase in cotransport inhibitory potency. We conclude that: (i) under basal conditions urinary equol can regulate Na-K-Cl cotransport activity in the kidney and (ii) salt-loading should evoke the appearance of other cotransport inhibitors.

Animals↗
PubMed1995

The effects of ultrapasteurization with and without homogenization on the chemical, physical, and functional properties of aseptically packaged liquid whole egg.

The effects of ultrapasteurization with and without homogenization on some chemical, physical, and functional properties of liquid whole egg were observed. Heat treatments of 64, 68, and 72 C each at 30, 60, and 95 s were conducted on liquid whole egg, unhomogenized and homogenized [10.34 mPa (1,500 psi)]. The viscosity of the egg increased with increased processing temperature, and unhomogenized egg was more viscous than homogenized egg. alpha-Amylase was inactivated at 68 C for 30 s. Although cake height was highly correlated to soluble protein content, this relationship did not hold for all time-temperature combinations. Due to homogenization effects on soluble protein results, soluble protein is not a reliable predictor of egg functionality when homogenization is used in the process. Homogenization had no effect on the population reduction of aerobic bacteria in all but three of the nine time-temperature combinations.

Bacteria, Aerobic↗
PubMed1995

Film oxygen transmission rate effects on ground chicken meat quality.

Effects of the packaging film oxygen transmission rate (OTR) on the odor, color, aerobic plate count, and cooked volatile compounds in ground chicken leg meat were evaluated over a 14-d refrigerated storage (4 C) period. Freshly desinewed and ground chicken leg meat was packaged under minimal vacuum in five films of different OTR. Films ranged from 30 to 12,000 mL oxygen/m2 per 24 h. Odor scores of meat in packages opened after 10 d were lower for the lowest OTR film than films with higher OTR. Aerobic plate counts increased at a faster rate in the higher OTR films, and cooked meat volatile profiles showed little variation due to OTR film type. Specific products will require different packaging to optimize shelf-life quality. For ground chicken leg meat, an intermediate OTR film is best to maintain a majority of the quality attributes during refrigerated storage.

Analysis of Variance↗
PubMed1993

Latina and African American women: continuing disparities in health.

Women of all races have faced incredible challenges as they sought to realize the promises of America. For women of color, these challenges were compounded by the second-class citizenship of U.S. racial and ethnic minority population groups. In an effort to assess the quality of life experienced by Latina and African American women, this article provides descriptive information on racial/ethnic differences in women's social conditions, health status, exposure to occupational and environmental risks, and use of health services. When possible, indices are stratified by family income to limit the effects of social class on the comparison of racial differences. The authors provide evidence that Latina and African American women are more likely than nonminority women to encounter social environments (e.g., poverty, densely populated neighborhoods, hazardous work conditions) that place them at risk for ill-health and injury. Although persistent racial disparities in health are often attributed to the lifestyle behaviors of racial minority populations, they are undoubtedly a consequence of poorer social conditions as well as barriers in access to quality health services. To achieve further gains, public policies must reduce social inequalities (i.e., by gender, race, and social class) and assure greater equity in access to resources that facilitate healthier environments and lifestyles. Public health initiatives should be community-based, reflecting a shared partnership that actively engages minority women in decision-making about their lives.

Adolescent↗
PubMed1993

[Cutaneous microcirculation in systemic sclerosis. Morpho-functional research using capillaroscopy and laser-Doppler].

Our previous researches proved that, in patients affected by Raynaud disease, microcirculatory alterations were greater in those cases in which the small vessels showed evocative appearances of a sclerodermatous connectivopathy. In this study we evaluated cutaneous microvasculature in 18 patients suffering from clear systemic sclerosis, compared with a group of 16 subjects affected by primitive Raynaud disease and a group of healthy subjects. We used videocapillaroscopy and laser-Doppler fluxmetry for morphological and functional study respectively. In patients affected by systemic sclerosis the rest flow was clearly reduced and morphological pattern of cutaneous small vessels deranged. The response to ischemic test allowed us to subdivide the skin-bounds in two subgroups: "no responders" 8 subjects (44%), in which reactive hyperaemia was completely absent, "responders" 10 patients (56%) in which the hyperaemia was completely overlapped with that of the two other groups, but with longer reaction times. In skinbounds the capillaroscopic pattern was clearly severe in comparison with other two groups (18.8 +/- 5.7 vs 5.7 +/- 2.3 and 3.6 +/- 1). Thus, in advanced stage of the pathology, is microangiopathy (in its tromboischemic and inflammatory aspects) that plays a very important role in the development of organ damage. Therefore, all those clinical and instrumental tests which may allow a differential early diagnosis between a primitive and a secondary Raynaud phenomenon be done, for its prognostic value in connection with the appearance of systemic sclerosis.

Adult↗
PubMed1986

[Argon laser trabeculoplasty in simple glaucoma].

In June 1984 the authors started a prospective study on the treatment of open-angle glaucoma with argon laser trabeculoplasty. The technique used was to treat 180 degrees of the anterior nonpigmented part of the trabecular meshwork with 80 to 100 burns. For retreatment the posterior pigmented part of the trabecular meshwork was coagulated with 80 to 100 burns. The burns were always applied to the pretreated half of the meshwork. At present the study includes 47 eyes treated posteriorly. Of these cases 12 eyes required retreatment. Five eyes had previously undergone an unsuccessful trabeculectomy. The preliminary results are satisfactory. The average reduction in intraocular pressure was 5.9 mm Hg; the mean intraocular pressure before therapy was 23 mm Hg. In 8 cases the trabeculoplasty failed, making a fistulating procedure necessary. The treatment was always well tolerated and there were only minor side effects which never led to any lasting damage.

Adult↗
PubMed1985

[Change in corneal refractive power following artificial lens implantation].

Report on the changes in the corneal refractive power of 284 eyes surgically treated for cataract, in which an IOL had been implanted. The mean corneal refractive power of the eyes was 43.31 +/- 1.43 D preoperatively and 43.39 +/- 1.46 D postoperatively (16th week). The postoperative astigmatism of 215 eyes in which a PCL had been implanted after ECCE was not higher than 1.1 +/- 1.1 D in the 16th postoperative week after selected removal of the nylon sutures. This study demonstrates that there is no statistically significant change in the mean corneal refractive power after cataract surgery with IOL implantation.

Astigmatism↗