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Biomedical subjects

M Romero

Publications and source records attributed to M Romero.

At least 109 records · Page 6Linked to original sources
PubMed1996

Effective, single-dose treatment or porcine cysticercosis with oxfendazole.

The pig is a vital link in the transmission cycle of Taenia solium, the cestode responsible for human-porcine cysticercosis. Infected pigs also represent an important source of economic loss to farmers in developing countries. Past efforts to find an adequate therapeutic regimen to treat this parasite disease in swine have failed because of low efficacy, high cost, side effects, or the need for multiple doses. In this randomized, no treatment-controlled study, the efficacy and safety of oxfendazole and praziquantel for the treatment of porcine cysticercosis were evaluated in 16 naturally infected pigs. Four groups of four pigs were treated with oxfendazole, praziquantel, oxfendazole plus praziquantel, or untreated. The pigs were humanely killed 12 weeks post-treatment, the number of cyst was counted, and parasite viability was assessed by cyst evagination. No detectable side effects were seen in any of the pigs. Praziquantel treatment alone appeared to reduce the number of cysts, but did not decrease the viability of the remaining parasites. Treatment with oxfendazole alone or oxfendazole plus praziquantel killed all of the parasites, and left only microcalcifications in the meat. Oxfendazole provides, for the first time, a practical, effective, inexpensive, and single-dose therapy for porcine cysticercosis.

Animals↗
PubMed1996

[Directional coronary atherectomy in ostial lesions of the anterior descending coronary artery].

INTRODUCTION AND OBJECTIVES: Coronary stenoses at ostial level, when treated by balloon angioplasty, show a primary success rate much lower than those located in other parts of the coronary tree. Balloon dilation of lesions located at the left anterior descending ostium is associated with a high degree of restenosis, elastic recoil and the possibility of retrograde dissection to the left main coronary artery. Simpson atherectomy may be considered a percutaneous alternative in this particular location, since this technique produces fewer incidents of elastic recoil than balloon dilation. The purpose of the present study is to evaluate directional atherectomy in the treatment of patients with symptoms deriving from severe to stenosis at the origin of the left anterior descending artery. MATERIAL AND METHODS: From a total number of 302 patients treated by Simpson atherectomy, we have analyzed 45 with severe stenosis at the left anterior descending ostium (less than 3 mm from its origin). The mean age was 54 +/- 12 years. Eighty two percent of the patients were male. The clinical condition was stable in unstable in 34; eleven had had a previous myocardial infarction. Six had multivessel coronary disease, all of them underwent combined balloon angioplasty of other segments. The treated lesion was native in 41 patients and previously dilated by balloon (restenosis) in 4. Two patients needed balloon predilation with 2 and 2.5 mm to facilitate the pass of the atherocatheter. The size of the Simpson atherocatheter was mainly 7F (78%). The weight of the resected arteriosclerotic material was 11 +/- 7 mg. RESULTS: Primary success (residual stenosis < 40% without major complications) was obtained in 42 out of 45 patients (93%); 3 patients (7%) had major complications (1 death, 1 emergency surgery, and 1 non-Q wave myocardial infarction). A follow-up angiography study was available in 31 patients 7 +/- 8 months later. Restenosis was evidenced in 12 (39%). CONCLUSIONS: Simpson atherectomy for left anterior descending artery ostial lesions is an effective transluminal alternative in selected patients providing a high rate of primary success (93%) and an acceptable restenosis rate (39%).

Adult↗
PubMed1995

Skeletal muscle necrosis and regeneration after injection of BaH1, a hemorrhagic metalloproteinase isolated from the venom of the snake Bothrops asper (Terciopelo).

The effects of BaH1, a hemorrhagic metalloproteinase isolated from Bothrops asper venom, on mouse gastrocnemius muscle was investigated. The toxin induced severe hemorrhage within minutes after injection. Groups of necrotic muscle fibers were observed after the sixth hour, with evident disorganization of myofibrillar material. At the ultrastructural level myofibrils in these cells lost their regular arrangement, Z lines were absent, and sarcomeres were disoriented, although there was no evidence of myofilament clumping or hypercontraction. Plasma membrane was interrupted in many portions. Mitochondrial alterations included swelling and the formation of flocculent densities and dense intracristal plates. At 12, 24, and 48 hr necrotic cells had amorphous masses of myofilaments and abundant phagocytic cells were observed both within necrotic fibers and in the interstitial space. Fraction D-1, which contains the three hemorrhagic metalloproteinases BaH1, BH2, and BH3, did not cause direct muscle damage when incubated with gastrocnemius muscle in vitro. Upon intramuscular injection in mice this fraction induced a small but significant increment in muscle lactic acid levels. Observations carried out 7 and 14 days after BaH1 injection revealed some regenerating muscle fibers with centrally located nuclei. However, other areas had few regenerating fibers of reduced diameter, surrounded by abundant fibroblasts, fibrosis, calcification, and remnants of necrotic muscle cells. When BaH1 was injected together with B. asper myotoxin III, a myotoxic phospholipase A2 that induces myonecrosis but does not affect blood vessels, a poor muscle regeneration was observed. In contrast, if B. asper myotoxin III was injected alone, regeneration proceeded normally and successfully.

Animals↗
PubMed1995

Balloon-expandable stent repair of severe coarctation of aorta.

Experimental studies have shown that stents implanted at the aorta become incorporated within the aortic wall and can be further expanded in growing animals. This study evaluates the feasibility and immediate results of balloon-expandable stent implantation in 10 patients with severe coarctation of aorta. The ages of the patients ranged from 1 month to 43 years; 1 was an infant, 8 were children (mean age 5.3 +/- 4 years), and 1 was an adult. All had an unfavorable anatomy for balloon angioplasty; 9 had isthmus hypoplasia. Balloon predilation was first performed and its immediate effect evaluated. Then a balloon-expandable stent that was 30 mm long and covered the isthmus and coarctation levels was deployed, and it was further expanded to the preselected final diameter (12 +/- 4 mm). A final hemodynamic and angiographic evaluation was then obtained. Full deployment of an incompletely expanded and distally displaced stent in the infant led to aortic disruption that was controlled by a second stent covering the disrupted zone and the isthmus. After balloon angioplasty alone was done, the mean gradient (43 +/- 12 vs 31 +/- 10 mm Hg) and the percentage stenosis (72% +/- 11% vs 54% +/- 11%) had an insufficient decrease. However, after stent implantation was done, the gradient almost disappeared (mean 2 +/- 3 mm Hg). The angiographic stenosis disappeared in 7 patients and was markedly reduced in 3. The ratio of isthmus/descending aorta changed from 0.65 +/- 0.14 to 1 +/- 0.08 (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1995

Follow-up patency of side branches covered by intracoronary Palmaz-Schatz stent.

To assess the risk of late side branch occlusion after Palmaz-Schatz stent deployment, we analyzed the angiographic evolution of 62 patients treated by successful stent implantation who had a total of 85 side branches starting from the stented segment. Side branches were considered minor (n = 39) when the diameter was < 1 mm and intermediate (n = 46) when the vessel had > or = 1 mm diameter. One angiographic follow-up study was available in all patients at 8 +/- 5 months. Eight minor branches presented some degree of stenosis at origin before stent deployment (4 totally occluded). After stent deployment, 32 (82%) of 39 remained unchanged and 3 became occluded. Late progression at origin occurred in 4 of 34 (3 occluded). Before stent deployment, 48% of the intermediate branches had some compromise degree at their starting point (1 totally occluded). Eight of 45 intermediate branches became occluded after stent implantation. Late progression at origin happened in 5 of 32 branches (2 occluded). Some degree of follow-up stenosis regression at the origin was observed in 22 (26%) of 85 arteries. Neither clinical nor angiographic factors could be identified as predictors of late side branch occlusion or stenosis progression at its origin. Later occlusion or progression at origin of a side branch covered by a Palmaz-Schatz stent seems to be an uncommon occurrence (7% and 12% respectively) that cannot be predicted by angiographic or clinical factors. On the contrary, regression at follow-up of a side branch-origin stenosis can also come about.

Adult↗
PubMed1995

Isolation and characterization of a metalloproteinase with weak hemorrhagic activity from the venom of the snake Bothrops asper (terciopelo).

A metalloproteinase, named BaP1, was purified to homogeneity from the venom of Bothrops asper (Pacific region) of Costa Rica by ion-exchange chromatography on CM-Sephadex and gel filtration on Sephacryl S-200. The enzyme has a mol. wt of 24,000 and contains few Cys and high numbers of Asp, Leu, Ser and Glu. BaP1 hydrolyzes casein, hide powder azure and fibrinogen, having an optimal pH of 8.0. It rapidly digests the A alpha-chain of fibrinogen and, later on, the B beta-chain, leaving the gamma-chain unaffected. Chelating agents (EDTA and 1,10-phenanthroline) inhibited proteolytic activity, whereas 2-mercaptoethanol and soybean trypsin inhibitor did not affect this activity. BaP1 has a weak hemorrhagic activity, with a minimum hemorrhagic dose of 20 micrograms; this activity was inhibited by EDTA and was abolished after incubation at 60 degrees C. In addition, BaP1 induces edema and a mild myotoxic effect, lacking coagulant, defibrinating and lethal effects.

Amino Acids↗
PubMed1995

Validity of a scale measuring beliefs regarding the "positive" effects of punishing children: a study of Mexican mothers.

This paper discusses the influence that "beliefs concerning the corrective effects of punishment" have on child punishment and abuse in a Mexican population. One hundred and five mothers responded to a questionnaire measuring these beliefs, and their responses were contrasted with the report those mothers gave regarding the physical punishment they inflict upon their children. A scale consisting of six items registering beliefs was developed and administered. The reliability (internal consistency) of the scale was assessed, and its validity was tested by using a factor analytic structural equations model which produced high factorial loadings from a "beliefs" factor to the scale's items. This was interpreted as a confirmation of construct validity. An indication of predictive validity was found in a high, significant structural correlation between the beliefs factor and a "corrective punishment" factor, measured by a series of related items. Mothers reported as abusing their children produced higher scores on the "beliefs" scale as compared to "control" mothers. The direct, significant effect of parent's beliefs on the punishment of children explains much about the child maltreatment problem in the studied society.

Adult↗
PubMed1995

Acute myocardial infarction treatments in 58 Italian hospitals: a drug utilization survey.

OBJECTIVES: To provide an updated and comprehensive profile of therapeutic practice in the management of acute myocardial infarction (AMI) in a sample of Italian hospitals, and to test the possible role of a network of hospital pharmacists in providing drug utilization data. DESIGN: Prospective drug utilization survey. Participating pharmacists collected information on patients consecutively admitted to the hospital with a suspected AMI. The form reproduced those adopted in the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto miocardico trials. SETTING: Fifty-eight general hospitals in Italy belonging to the National Health Service, 6 of which are teaching hospitals. Thirty-four hospitals recruited patients from a coronary care unit, 10 from intensive monitoring beds in cardiology wards, and 14 from an intensive care unit. PARTICIPANTS: The study population consisted of patients consecutively admitted with a suspected AMI from May 31 through July 5, 1993. MAIN OUTCOME MEASURES: The management of AMI in terms of the use of drugs and nonpharmacologic treatments is described. RESULTS: Of the 676 patients recruited for the study, 47.8% received thrombolytic therapy; alteplase was the preferred agent (55.4% of treated patients). The use of thrombolytic therapy varied significantly according to different demographic and clinical parameters such as age, sex, delay from the onset of symptoms to admission, and Killip scale class. During the first day of hospitalization 63.9% of patients received aspirin, 83.3% received nitrates, 24.8% received beta-blockers, and 77.1% received heparin therapy. CONCLUSIONS: Thrombolytic therapy was prescribed in a higher percentage of patients than is reported in the US, but lower than that reported in large trials. That a low percentage of patients who experienced a long delay between the onset of symptoms and admission as well as elderly patients received thrombolytic therapy reflects the lower expectations of clinicians for these subgroups of patients. A low proportion of patients received aspirin therapy. This study showed that in Italy an institutional network of hospital pharmacists could be interested observers of therapeutic practice, but further training is needed before high-quality data can be collected.

Adrenergic beta-Antagonists↗
PubMed1995

Protective effect of coconut oil on renal necrosis occurring in rats fed a methyl-deficient diet.

Weanling rats fed a methyl-deficient diet develop renal necrosis with acute renal failure. The aim of this experiment was to explore further the role of coconut oil in this experimental model. Weanling Wistar male rats were fed methyl-deficient and their controls were fed methyl-supplemented diets. Coconut oil was fed at 14% and 20%, the latter concentration with and without 1% safflower oil (rich in linoleic acid); other groups received similar diets but instead of coconut oil, a mixture of hydrogenated vegetable oil and corn oil (rich in unsaturated fatty acids) was employed. Coconut oil fed at a 14% concentration did not evidence any protective outcome in relation to the renal lesions. Coconut oil at a 20% concentration showed a protective effect, mainly when the diet included safflower oil. The renal protective effect was evidenced by less or no mortality and increased survival time in the methyl-deficient rats receiving coconut oil, as well as by a reduced incidence (%) and severity of the renal lesions as evaluated by renal weight, and type (tubular and cortical necrosis or repair) and extent (grade) of the renal damage. The lack of a protective outcome when coconut oil was fed at 14%, along with the fact that in those rats receiving coconut oil at 20% the protection was greater when the diet was supplemented with 1% safflower oil, indicates that the protective effect should be attributed to the type of fatty acids coconut oil has and not to their shortage of essential fatty acids.

Animals↗
PubMed1995

[Recessive distal myopathies. Five cases].

We present five patients with distal weakness in the lower extremities with onset in adolescence. Paresis tended to occur in the gastrocnemia in 3 patients and was accompanied by marked elevation of CPK (> 10 times higher than normal). Muscle biopsies showed signs of dystrophy. The clinical picture for these patients was consistent with the diagnosis of recessive distal myopathy (Miyoshi's form). The differential sign in the other 2 cases was greater involvement of the anteroexternal leg muscles and the presence of rimmed vacuoles similar to those characteristic of Nonaka's vacuolar distal myopathy.

Adolescent↗
PubMed1994

Estimating maternal mortality in rural areas of Mexico: the application of an indirect demographic method.

OBJECTIVE: To measure maternal mortality levels in rural areas of Mexico. METHODS: In a cross-sectional study, a census of 13,378 households was carried out in the municipalities of Yecapixtla and Tlaltizapan, Morelos, Mexico. Information on 10,443 subjects from 12 to 49 years old was included in the analysis. An indirect method of measuring maternal mortality--the sisterhood method--was used to estimate maternal mortality. Information about the number of sisters of the interviewees who died due to maternal causes was collected in the census. With this information, estimates of maternal mortality related to a period of 10-12 years before the application of the census were obtained. An innovation to the original method was the calculation of a confidence interval for the estimated maternal mortality rate (MMR). RESULTS: The MMR in this region was 18.68/10,000 live births (95% CI 15.79-21.58/10,000 live births). The average risk of dying due to maternal causes was 1 in 87 for women between 12 and 49 years of age. CONCLUSIONS: The sisterhood method was effective for estimating maternal mortality in a small region, with no previous information about this indicator. The method proved to be useful for identifying a priority region for the implementation of maternal mortality reduction programs. Furthermore, the method was particularly convenient since it was applied as part of a multipurpose survey.

Adolescent↗
PubMed1994

Frequency of HLA-DPB1 alleles in a Spanish population: their contribution to rheumatoid arthritis susceptibility.

HLA-DPB1 allele frequencies in 181 unrelated control individuals and 70 rheumatoid factor-positive RA patients from Seville (Spain) were determined using oligonucleotide typing methods. All frequencies shown concern the percentage of individuals positive for a certain allele. HLA-DPB1*0401 was the most common DPB1 allele in the healthy individuals, possessed by 65.7% of them. In addition to HLA-DPB1*0401, only the following alleles were found in normal subjects at frequencies greater than 10%: DPB1*0101 (15.5%), DPB1*0201 (12.2%), DPB1*0301 (16.6), and DPB1*0402 (29.3%). When HLA-DPB1 allelic frequencies were compared between seropositive RA patients and controls, a negative association for DPB1*0301 and DPB1*0401 was found in RA patients, although it failed to reach statistical significance after correction for the number of comparisons made. The other DPB1 alleles exhibited almost identical frequencies in both groups. However, when only DR4+ patients and controls were considered, the decrease in the frequency of the DPB1*0301 and DPB1*0401 alleles lacked statistical significance. On the other hand, when DR4- RA patients and controls were compared, the frequency of DPB1*0301 was found decreased significantly again, even more than in the whole group of patients.

Alleles↗
PubMed1994

Expression of adhesion molecules in poststreptococcal glomerulonephritis.

Because adhesion properties of leukocytes are important for the influx and localization of leukocytes in sites of inflammation, we studied, the expression of intercellular adhesion molecule 1 (ICAM-1), lymphocyte-function-associated antigen 1 (LFA-1), vascular cell adhesion molecule- 1 (VCAM-1) and CD 11b in 14 kidney biopsies of PSGN patients, arbitrarily divided into early biopsies (less than 15 days after onset of PSGN) and late biopsies (17-90 days). In PSGN, intraglomerular ICAM-1 expression was increased in early biopsies (score 3.1 +/- SEM 0.2; P < 0.005) and decreased with time; in late biopsies the score (2.0 +/- 0.2) was similar to that of normal kidney (1.3 +/- 0.3). In the interstitium ICAM-1 was increased (early PSGN = 836 +/- 56 positive cells/mm2, late = 552 +/- 60.0; versus normal = 364 +/- 12.4; P < 0.05). LFA-1 expressing cells in glomeruli were also increased in early biopsies (10.0 +/- 2.1 positive cells per glomerular cross-section (gcs), versus normal 2.9 +/- 1.4; P < 0.05). In the interstitium, LFA-1 positive cells were increased (early PSGN = 221 +/- 79.6 cells/mm2, late PSGN = 134.5 +/- 45.1, normal = 21 +/- 8.7; P < 0.05). VCAM-1 in glomeruli and interstitium was not increased in PSGN. Our studies demonstrate increased expression of adhesion molecules ICAM-1 and LFA-1 in the kidney of PSGN patients, and these findings were more pronounced in early biopsies; adhesion molecules are probably involved in the inflammatory infiltration of this disease.

Adolescent↗
PubMed1993

An MTT-based method for the in vivo quantification of myotoxic activity of snake venoms and its neutralization by antibodies.

The reduction of the tetrazolium compound MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) was used as the basis for the development of a simple method for the quantitative estimation of metabolically active skeletal muscle tissue remaining after in vivo venom-induced myonecrosis. Using the venom of the snake Micrurus nigrocinctus as a potent myotoxic agent, this MTT-based technique was evaluated in comparison with available methods based on the measurement of creatine kinase (CK) activity, and a quantitative histological technique considered as a reference. Homogenates of the gastrocnemius muscle prepared in the presence of 1% Triton X-100 reduced MTT and this activity correlated closely with the number of viable cells in the tissue, as determined by histological evaluation. After venom injection, residual MTT-reducing activity of muscle homogenates showed higher correlation to the myonecrosis index obtained by histological analysis, than residual muscle CK activity. Using the new MTT-based assay, the ability of an anti-M. nigrocinctus equine antivenom to neutralize venom myotoxins was studied. The myotoxic activity of the venom was completely neutralized using 4 ml antivenom/mg venom, with a 50% effective dose (ED50) value of about 2.5 ml/mg. The MTT-based method described should be useful in the estimation and standardization of anti-myotoxic potency of antivenoms, and in the screening of other neutralizing agents, as a convenient and reliable alternative to the time-consuming quantitative histological methods.

Animals↗