Biomedical subjects

M Lemus

Publications and source records attributed to M Lemus.

At least 19 recordsLinked to original sources

PubMed2004

Antifungal activity of actinomycetes from Cuban soils.

This study reports on the capacity of actinomycete strains isolated from Cuban soils to produce antifungal agents. The antimicrobial activities were determined by susceptibility disk assay methods. We isolated 563 different actinomycetes and 286 produced compounds with antifungal activity. Our screening method indicated the presence of many possible polyene macrolide antibiotics and the important antifungal activity in the soils rich in minerals.

Actinobacteria↗

PubMed2001

Arginine-vasopressin in nucleus of the tractus solitarius induces hyperglycemia and brain glucose retention.

Hypothalamic arginine-vasopressin (AVP) plays an important role both as a neurotransmitter and hormone in the regulation of blood glucose and feeding behavior. AVP-containing axons from the parvocellular subdivision of paraventricular nucleus of the hypothalamus terminate in the nucleus of the tractus solitarius (NTS), but the function of this projection is not known. Interestingly, the NTS also receives afferent information from the carotid body and other peripheral receptors involved in glucose homeostasis. We have previously reported that stimulation of the carotid body receptors initiates a hyperglycemic reflex and increases brain glucose retention. Here we show that direct administration of micro-doses of AVP into the NTS of anesthetized or awake rats rapidly increased the levels of blood glucose concentration and brain arterio-venous (A-V) glucose difference. This effect was not observed when the same doses of AVP were injected in the brainstem outside NTS. Arginine-vasopressin antagonist microinjections alone produced a small but significant reduction in brain A-V glucose. Pre-administered VP1-receptor antagonist [beta-mercapto-beta,beta-cyclopentamethylene-propionyl(1),O-Me-Tyr(2),Arg(8)]vasopressin blocked the effects of AVP. These results indicate that AVP acting on its receptors locally within the NTS participates in glucose homeostasis, increasing both blood glucose concentration and brain A-V glucose differences. Hypothalamic AVP may facilitate hyperglycemic responses initiated by peripheral signals processed at the level of the NTS.

Animals↗

PubMed2000

[Kinetic incorporation of mercury in Emerita portoricensis (Crustacea: Decapoda)].

Benthic test species used in toxicity assays are the best indicators of sediment toxicity because they live in direct contact with sediments and the water column. Mercury chloride is one the most toxic metallic salts. Its strong affinity for particles explains the high Hg content found in benthic populations. The genus Emerita is abundantly found in Venezuelan coasts and is a good bioaccumulator of pollutants, but the toxicological assays performend on this genus are scarce. The present experimental test reports on the distribution of mercury in the water column and sediment, using static bioassay in short term (24 hr) and the ability of Emerita portoricensis to bioconcentrate mercury under experimental conditions. Our results suggest that the Hg transference from water to sediment is enhanced in the presence of Emerita. The kinetic uptake of Hg in Emerita portoricensis shows a mechanism of rapid absorption reaching high metal concentrations in short exposure times.

Animals↗

PubMed2000

[Cooper, cadmium and lead in the fish Cyprinodon dearborni, in the sediments and in the water of two lagoons in Venezuela].

The concentration of copper, cadmium and lead in superficial sediment, water and the fish Cyprinodon dearborni was determined in two coastal lagoons of Sucre State, Venezuela. Chacopata lagoon is hyper saline while Los Patos lagoon is hypo saline and receives significant wastewater from Cumaná city. Water, sediment and fish samples were collected in February 1998. In the laboratory, samples underwent acid digestion and were analyzed by atomic absorption spectophotometry. The mean values of the metals in C. dearborni from the Chacopata lagoon were: 159.26 +/- 210.68 microg/g for Cu, 44.71 +/- 45.58 microg/g for Cd, and 9.31 +/- 23.34 microg/g for Pb, while for Los Patos lagoon the mean values were: 64.88 +/- 16.30, 19.48 +/- 5.81 and 22.85 +/- 20.00, respectively. In the water column, the metal concentration ranges were: 2.3-11.6, 3.9-5.4 and 21-32 mg/l for copper, cadmium and lead, respectively. These results suggest that metal levels in sediment, water column and organisms in both lagoons do not differ, except for lead, even though only Los Patos receives waste water.

Animals↗

PubMed1999

Ecological approach of macrolide-lincosamides-streptogramin producing actinomyces from Cuban soils.

We report in this study the frequency of Streptomyces strains to produce macrolide-lincosamide-streptogramin (MLS) antibiotics isolated from Cuban soils. The screening assay is based on the induction of MLS-resistance phenotype in a clinical isolated strain of Staphylococcus aureus S-18. Our results suggest that of 800 Streptomyces strains isolated from different soil samples, 6% were positives in the screening test used. The ferralitic red soil from Pinar del Río (north) provided the major percentage (3.6%) of MLS producing strains. The other soil samples tested belonging to Guira de Melena and Bauta in Havana, Matanzas City, Topes De Collantes (Villa Clara), and Soroa Mountains (Pinar del Rio) hill reached very low percentages.

Anti-Bacterial Agents↗

PubMed1993

[Practicability of panoramic hysteroscopy with CO2. Clinical experience: 923 cases].

Between 1987 and 1990, Diagnostic Panoramic Hysteroscopies with CO2 as distending medium was proposed in 890 cases. Age groups, complications and failures are discussed. The notion of "insufficient" hysteroscopy is defined as well as the attitude toward this situation. A technique, vaginoscopy is described, making possible to perform the examination in patients that never had sexual intercourse or senile patients. Vaginoscopy and repetitive hysteroscopy after the first hysteroscopy found insufficient are important tools to achieve good diagnosis and fewer than 1% failure of the procedure among patients with narrow introitus.

Adult↗

PubMed1989

[Diagnosis and treatment with Marlex mesh of vaginal posterior hernia].

A new surgical technic is described, for the vaginal posterior hernia (enterocele). The authors used the "Marlex" mesh in 6 patients with success.

Female↗

PubMed1989

[Selective and ambulatory salpingography].

A new technique is here proposed to enhance, in a selective or direct way, the fallopian tubes. This new approach is suggested because hysterosalpingography (with the filling of the uterine cavity) is an indirect procedure, and therefore not completely reliable. Since intrauterine pressure cannot exceed 200 mmHg, and more pressure is needed to reach the tube ostia, false negatives are produced; up to 50% of the fallopian tubes not enhanced during hysterosalpingography are normal. Thurmond et al. were the first to introduce selective salpingography. They used a blind procedure with fluoroscopy passing through the uterine cavity, catheterized, with probes, and performed repeated fluoroscopic examinations of the uterine cavity. We suggest a different technique consisting in the use of hysteroscopy to visualize the ostium, and of a direct image to place the probe into the fallopian tube. The intubation is then repeated, if needed, in the other tube, which is then enhanced with the conventional means. X-ray pictures of both tubes will then be made. The technique is thus a simple and quick one, which can be carried out on an out-patient basis at the Radiology Department, without premedication, and with no need for previous preparation. Neither is it necessary to dilate the cervix nor to anesthesize the patient if the Karl-Storz chorionscope is used, which has proved the most useful instrument for this purpose. No complications were observed and the contraindications were similar to those of hysterosalpingography and hysteroscopy. To optimize the method, 16 direct fallopian tube intubations were carried out on a selected group of patients suffering from different kinds of infertility. The procedure lasted no longer than 20 minutes, was well tolerated, and allowed the patients to immediately resume their usual activities. We believe this practical technique to be the procedure of choice when one/both fallopian tubes are not enhanced during conventional hysterosalpingography.

Female↗

PubMed1985