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Biomedical subjects

M Sanchez

Publications and source records attributed to M Sanchez.

232 records · Page 13Linked to original sources
PubMedDate not supplied

Actinoplanic acids A and B as novel inhibitors of farnesyl-protein transferase.

Actinoplanic acids A and B are macrocyclic polycarboxylic acids that are potent reversible inhibitors of farnesyl-protein transferase. Actinoplanic acids A and B were isolated from Actinoplanes sp. MA 7066 while actinoplanic acid B was isolated from both MA 7066 and Streptomyces sp. MA 7099. Actinoplanic acids A and B are competitive with respect to farnesyl diphosphate and are selective inhibitors of farnesyl-protein transferase because they do not inhibit geranylgeranyl-protein transferase type 1 or squalene synthase. MA 7066 is believed to be a novel species of actinomycetes while MA 7099 is believed to be a novel strain of Streptomyces violaceusniger on the basis of morphological, biochemical and chemotaxonomic characteristics as well as its production of actinoplanic acids.

Actinomycetales↗
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Septic shock: pathogenesis and treatment.

Septic shock is the host's inflammatory response to infection. There are multiple endogenous mediators responsible for the pathogenesis of septic shock. Cytokines, nitric oxide and prostaglandins are some of the major mediators. The term sepsis syndrome allows for an earlier diagnosis and treatment. Management of septic shock is focused in maintaining hemodynamic stability and an adequate oxygen delivery and utilization. Careful attention to each organ-system is of paramount importance to prevent complications and improve outcome. Experimental therapies to modulate the inflammatory response are promising.

Acute-Phase Proteins↗
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HIV-associated pruritus.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
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Blood lead levels in children in south central Los Angeles.

We retrospectively reviewed 3 679 pediatric records from King/Drew Medical Center, south central Los Angeles, between 1991 and 1994. Blood lead levels of children were followed to age 18 y. Patients were not referred specifically for lead poisoning. The sample was primarily Latino. Geometric mean blood lead peaked at 6.7 micrograms/dl (0.32 mumol/l) between 2 and 3 y of age. There was a downward secular trend and a seasonal trend. Males had higher lead levels than females. Children who lived in several zipcode areas, in which the lowest family incomes were reported, had higher lead levels. More Latino children had higher lead levels than African American children. Latino children (i.e., 20.2%) who were 1-5 y of age had blood lead levels that were > or = 10 micrograms/dl. Young Latino children in this zone of Los Angeles may be at increased risk for lead exposure.

Adolescent↗
PubMedDate not supplied

Maternal blood lead level during pregnancy in South Central Los Angeles.

Twenty-five years of public health efforts produced a striking reduction in lead exposure; the blood lead average in the United States has decreased to less than 20% of levels measured in the 1970s. However, poor minority groups that live in large urban centers are still at high risk for elevated lead levels. In this study, our data showed that pregnant immigrants (n = 1,428) who live in South Central Los Angeles--one of the most economically depressed regions of California--have significantly higher (p < .0001) blood lead levels (geometric mean = 2.3 microg/dl [0.11 micromol/l]) than 504 pregnant nonimmigrants (geometric mean = 1.9 microg/dl [0.09 micromol/l]). The most important factors associated with lower blood lead levels in both groups were younger age; more-recent date of blood sampling (i.e., decreasing secular trend); and blood sampling in mid-autumn, instead of mid-spring (i.e., seasonal trend). Blood lead levels of immigrants were strongly dependent on time elapsed since immigration to the United States; each natural log increase in years of residence was associated with an approximately 19% decrease in blood lead levels. Although blood lead means for both groups were almost the same as the estimated national average, 25 of the 30 cases of elevated blood lead (i.e., > or = 10 microg/dl [0.48 micromol/l) occurred in the immigrant group. The odds ratio (95% confidence intervals within parentheses) for having elevated blood lead levels (a) was 9.3 (1.9, 45.8) if the immigrant engaged in pica; (b) was 3.8 (1.4, 10.5) if the immigrant had low dietary calcium intake during pregnancy; and (c) was .65 (.43, .98) for every natural log unit increase of years of residence in the United States. The control of pica and dietary calcium intake may offer a means of reducing lead exposure in immigrants.

Adolescent↗
PubMedDate not supplied

Blood lead level and blood pressure during pregnancy in South Central Los Angeles.

In many studies in which the relationship between blood pressure and blood lead level has been examined, investigators have found significant--but small--associations. There was only one previous report of a significant association of blood lead with blood pressure in pregnant women. We measured blood lead level and sitting blood pressure of 1,627 women in their third trimester of pregnancy. We eliminated subjects with known causes of hypertension. Most women (98.4%) were normotensive. We controlled for body mass index, age, and stress--among other factors--and constructed multiple-regression models of lead association with diastolic and systolic blood pressures. Immigrants (73% of total) had significantly higher blood lead levels and different blood pressures than nonimmigrants, suggesting that analysis be stratified by "immigrant, nonimmigrant" status. Positive relationships between blood lead level and blood pressure were found only for immigrants (p < or = .001). From the 5th to 95th blood-lead percentiles (0.9-6.2 microg/dl) in immigrants, systolic blood pressure increased 2.8 mm Hg, and diastolic blood pressure increased 2.4 mm Hg. Higher prior lead exposure of immigrants (97.7% from Latin countries) than nonimmigrants might explain the differential effect of these low levels of blood lead on blood pressure in nonimmigrants. Perhaps some immigrants are at higher risk than nonimmigrants for lead-associated elevated blood pressure during pregnancy, despite blood lead levels within the currently considered acceptable range.

Adult↗
PubMedDate not supplied

Skin response to ultraviolet B light in patients infected with human immunodeficiency virus.

Photosensitivity disorders have been reported in human immunodeficiency virus (HIV)-infected patients, often as the initial manifestation of the disease. The objective of this study was to evaluate whether the HIV-infected population demonstrates increased sensitivity to ultraviolet B (UVB) radiation. Minimal erythema dose values to UVB (MED-B) of 57 consecutive HIV-infected patients were compared to those of a control group of 57 consecutive patients with skin diseases, who were otherwise healthy and had no risk factors for HIV infection. MED-B determinations were performed in all individuals prior to the initiation of phototherapy for treatment of skin disease. None of the patients had a history of photosensitivity. Furthermore, the mean levels of the highest UVB doses received by each group during the treatment courses were compared. The mean age of the HIV-infected cohort was 43 years (range 26-61 years). The mean MED-B for this group was 82.8 +/- 3.8 (SEM) mJ/cm2. The mean age of the control group was 45 years (range 24-77 years), and their mean MED-B was 81.0 +/- 3.8 (SEM) mJ/cm2. After 12 weeks of treatment, one HIV-infected patient developed photosensitivity associated with a decreased MED-B value. The mean level of the highest UVB doses received by the HIV-infected group [427.5 +/- 67.2 (SEM) mJ/cm2] was lower than that received by the control group [640.8 +/- 65.9 (SEM) mJ/cm2], since HIV-infected patients received fewer treatments (mean: 34.7 treatments per patient) than the patients in the control group (mean: 65.6 treatments per patient). These data indicate that the HIV-infected patient population, without history of photosensitivity, does not show increased sensitivity to UVB light as determined by MED-B values.

Adult↗
PubMedDate not supplied

Diet, lipids and brain development.

Brain development is a sequential anatomical process characterised by specific well-defined stages of growth and maturation. One of the fundamental and necessary events in the normal development of the central nervous system in vertebrates is the formation of a myelin sheath. It is becoming more evident that this process is influenced by dietary lipids. A number of findings have indicated that the administration of a diet deficient in essential fatty acids during development causes hypomyelination in the rat brain. Our studies have shown that lipids can also play a role in accelerating myelinogenesis in the brain of rats whose mothers had been fed, during pregnancy and lactation, a lipid fraction extracted from yeast grown on n-alkanes. Further studies have shown that accelerated myelinogenesis is connected to a precocious appearance of behavioural reflexes. Thus, the use of particular lipids in human nutrition must be carefully screened for possible effects on brain development.

Animals↗
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Effects of fibrin sealant on incorporation of autograft and xenograft tendons within bone tunnels. A preliminary study.

The anterior and posterior tibialis tendons in both hindlimbs of six adult dogs were rerouted through extraarticular bone holes created in the distal tibial metaphysis. Xenograft tendons of comparable dimensions were used in an additional six dogs. Fibrin Sealant System (FSS) was applied to the bone tendon interface in the right legs, whereas the left legs were used as controls. The animals were sacrificed at 5, 9, and 28 days. Coronal sections of the distal tibias were studied histologically and microangiographically. The autogenous tendons appeared to incorporate by means of fibrous ingrowth, whereas spicules of new bone in direct opposition to the xenografts were observed at 28 days. FSS promoted organization and maturation of fibrous connective tissue surrounding both implants at early sacrifice but did not appreciably alter incorporation at 28 days.

Animals↗
PubMedDate not supplied

Survey of canine heartworm in the city of Recife, Pernambuco, Brazil.

Six hundred and eleven random-source dogs (338 male, 273 female) one year of age or older, from six sections of the city of Recife, Pernambuco, were examined antemortem for circulating microfilariae Dirofilaria immitis and Dipetalonema reconditum adult heartworm (D. immitis) antigen, and examined postmortem for adult heartworms. The prevalence of heartworm infection was 2.3% (14/611), as determined by necropsy for adult worms, and 1% (6/611) had circulating microfilariae of D. immitis; thus, 57.1% of the heartworm-infected dogs had occult infections. The results of serological testing indicated that 1.3% (8/611) of the dogs were positive for adult heartworm antigen. A total of 42 (6.9%) of the dogs had microfilariae of D. reconditum; 40 of these had only D. reconditum and two additional dogs had microfilariae of both species, D. immitis and D. reconditum.

Animals↗
PubMedDate not supplied

[Design of a vaccination campaign against hepatitis b virus].

Plans for a vaccination campaign among the health care personnel at the "Valle del Nalón" Hospital are discussed. For this purpose, first of all, the serological testing to determine the markers as compared to the VHB was done using the ELISA technique, and in following, the vaccine based on genetic engineering, ENGERIX BR was provided, initially according to the criteria established to this effect by law, and then from a less restricted view, according to the principles which are given in the text. We have observed that 14.74% of the workers in our town have some positive marker priori to the vaccination and that 1.81% are carriers. The level of tolerance was that of 45.79%, said level being related to the professional group in question and the service in which they work, differences obtained in both cases being statistically quite significant (p less than 0.0001).

Hepatitis B↗