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Biomedical subjects

M Hinojosa

Publications and source records attributed to M Hinojosa.

At least 19 recordsLinked to original sources
PubMed2005

Development of an HPLC method for determination of diphenidol in plasma and its application in an oral multi-dose bioequivalence study in a healthy female Mexican population.

Diphenidol was determined by an HPLC method developed in our laboratory. It was validated and proved to be linear in the 40-400 ng/ml range. Accuracy for quality-control samples for intra and inter day assays ranged from 96.1-98.9% and 98.8-101.4%, respectively. This method was applied to a multi-dose bioequivalence study. No serious side effects were observed in the multi-dose design. Pharmacokinetic parameters (mean+/-standard error [S.E.]) of Cavg (ng/ml) and AUCtau (ngh/ml) for reference and test products were 139.54+/-12.66 versus 148.60+/-16.51 and 551.07+/-53.53 versus 588.78+/-69.02, respectively. Log-transformed values were compared by analysis of variance (ANOVA) followed by the classical 90% confidence interval (CI 90%) test and Schuirmann's test. Confidence limits ranged from 91.48-116.18% for Cmax and from 91.24-117.65% for AUCtau. These results suggest that the analytical method was linear, precise, and accurate for our purpose, and that both assayed formulations were bioequivalent.

Adult↗
PubMed2005

Bioequivalence evaluation of two brands of meloxicam tablets (Promotion and Mobicox): pharmacokinetics in a healthy female Mexican population.

We conducted a randomized, crossover study in 23 healthy young female volunteers to compare the bioavailability of two brands of meloxicam (7.5 mg) tablets and to obtain pharmacokinetic parameters of this molecule in Mexican population not reported previously. Two tablets (15 mg) were administered as a single dose on 2 treatment days separated by a 1-week washout period. After dosing, serial blood samples were collected for a period of 72 h. Plasma harvested was analyzed for meloxicam by a modified and validated high-performance liquid chromatography (HPLC) method previously reported. Pharmacokinetic parameters AUC(0-t), AUC(0-alpha), C(max), T(max), k(e), MRT and t(1/2) were determined from plasma concentrations of both formulations, resulting in a C(max) 120% larger than and a T(max) 65% faster than those reported in other populations. AUC(0-t), AUC(0-alpha), and C(max) were statistically tested for bioequivalence after log transformation data in a non-balanced design, and no significant differences were found either in 90% classical confidence interval (90% CI) or in Schuirmann test (p < 0.05); thus, we concluded that bioequivalence existed between both formulations.

Administration, Oral↗
PubMed2004

Bioequivalence evaluation of two brands of ketoconazole tablets (Onofin-K and Nizoral) in a healthy female Mexican population.

A randomized, crossover study was conducted in 24 healthy female volunteers to compare the bioavailability of two brands of ketoconazole (200 mg) tablets; Onofin-K (Farmacéuticos Rayere S.A., Mexico) as the test and Nizoral (Janssen-Cilag, Mexico) as the reference products. The study was performed at the Clinical Pharmacology Research Center of the Hospital General de Mexico in Mexico City. Two tablets (400 mg) were administered as a single dose with 250 ml of water after a 12 h overnight fast on two treatment days separated by a 1 week washout period. After dosing, serial blood samples were collected for a period of 12 h. Plasma harvested was analysed for ketoconazole by a modified and validated HPLC method with UV detection in the range 400-14000 ng/ml, using 200 microl of plasma in a full-run time of 2.5 min. The pharmacokinetic parameters AUC(0-t), AUC(0-alpha), Cmax, Tmax and t(1/2) were determined from plasma concentrations of both formulations and the results discussed. AUC(0-t), AUC(0-alpha) and Cmax were tested for bioequivalence after log transformation of data, and no significant differences were found either in 90% classic confidence interval or in the Anderson and Hauck test (p < 0.05). Based on statistical analysis, it is concluded that Onofin-K is bioequivalent to Nizoral.

Adolescent↗
PubMed2003

Celecoxib, a highly selective COX-2 inhibitor, is safe in aspirin-induced asthma patients.

BACKGROUND: In 5-10% of adult patients with asthma, aspirin and most other nonsteroidal anti-inflammatory drugs (NSAIDs) precipitate acute asthmatic attacks. Therefore, choosing an alternative anti-inflammatory agent for patients who have suffered adverse reactions to a nonsteroidal anti-inflammatory agent is a common problem in clinical practice. The discoveries that cyclooxygenase COX-2 is an inducible form of COX involved in inflammation and COX-1 is the major isoform responsible for the production of prostaglandins have provided a reasonable basis for the development of specific COX-2 inhibitors as a new class of anti-inflammatory agents. OBJECTIVE: The purpose of this study is to demonstrate that celecoxib, a specific inhibitor of COX-2, does not cause asthmatic attacks in patients with aspirin and/or other nonsteroidal anti-inflammatory drug-induced asthma. METHODS: We studied 33 patients, all of whom suffered from asthma induced by at least two different NSAID drugs. They were challenged in a single-blind manner with different doses of celecoxib on three different days, until either the therapeutic dose of 200 mg or intolerance was reached. Each patient was rechallenged with 200 mg celecoxib seven days later if no evidence of intolerance was previously observed. RESULTS: Celecoxib 200 mg was proven to be well tolerated in all 30 three aspirin- and NSAID-induced asthma patients. CONCLUSION: Our study appears to demonstrate that celecoxib is a suitable NSAID in aspirin-induced and/or nonsteroidal anti-inflammatory drug-induced asthma patients.

Adult↗
PubMed2002

Drug use, travel and HIV risk.

A study was conducted to examine the travel experiences of a community sample of 160 drug users and 44 non-users recruited as part of a study of HIV risk. Of the sample, 47% (96/204) reported intercity travel in the previous ten years. Results showed that men were more likely to travel than women, Anglos more than minorities, and young persons more than old. When travellers testing HIV-seropositive (n = 13) were compared with seronegative travellers, HIV-positive travellers reported more sex while travelling than HIV-negative persons, but virtually all of the difference reported involved sex with condoms. There were no significant differences in sex risk behaviours while travelling between drug users and non-drug users, or in sex risk behaviors between drug injectors and non-injectors. Travellers had fewer injection partners while travelling than they had while at home. There was also a significant difference in number of sex partners with whom a condom was not used, with fewer sex partners while travelling.

Adult↗
PubMed2001

Dermoid cyst in the posterior fossa accompanied by Klippel-Feil syndrome.

OBJECTS: Dermoid cysts accompanied by Klippel-Feil syndrome are uncommon, and the coincidence of these two rare diseases suggests an interesting idea about the pathogenesis of a dermoid cyst, which the authors consider with reference to an actual case. A posterior fossa dermoid cyst with dermal sinus and Klippel-Feil syndrome are reported in the same patient. A 23-year-old woman was admitted to hospital with progressive headaches. METHODS: Cervical radiography demonstrated C4-5 vertebral fusion, and magnetic resonance imaging revealed a large cystic mass in the midline of the posterior fossa. The cystic lesion was totally removed along with the accompanying dermal sinus. It was histopathologically diagnosed as a dermoid cyst. CONCLUSION: The rare coincidence of a dermoid cyst and Klippel-Feil syndrome suggests the possibility that a disturbance in the mesoderm before the fourth week of gestation might play an important part in the causation of dermoid cyst.

Adult↗
PubMed2001

Microwaves as an energy source for producing beta-SiC.

This work describes the production of silicon carbide using microwaves as the energy source, which was supplied by means of variable power, up to 2000 Watts, magnetron operating at 2.45 GHz. The obtained samples were analyzed by means of X-ray diffraction and observed with electron microscopy (SEM). Temperatures achieved were around 2000 degrees C, which is the upper limit for the beta-SiC growth regime, before getting other SiC polytypes. Analysis of different portions of the sample showed that beta-SiC was the only formed compound, although free SiO2 and graphite were also present. Observations made by SEM demonstrated different crystal growth regime, meaning that thermal conditions were not totally uniform. The amount of beta-SiC found and the relative simplicity of the device prove that production of this material from silica and graphite is possible by applying microwaves as an energy source.

Carbon Compounds, Inorganic↗
PubMed2001

Stipatosis or hypersensitivity pneumonitis caused by esparto (Stipa tenacissima) fibers.

Hypersensitivity pneumonitis or extrinsic allergic alveolitis may be defined as an immunological pulmonary disease caused by a variety of antigens reaching the lungs through inhaled organic and inorganic dusts derived from different sources, although they are usually occupational. Farmer's lung and pigeon breeder's lung are probably the most well-known types of hypersensitivity pneumonitis worldwide. Esparto grass (Stipa tenacissima), which is a grammineous plant which is commonly found in the Mediterranean countries, has a wide variety of uses. Esparto fiber is used for the manufacturing of ropes, hemp sandals, rush mats and parkets; for decorative stucco plates, used on walls and ceilings. Esparto supports a large industry in Spain. The first reports referring to esparto dust as a cause of respiratory disease did not appear until the 1960s, and it was first described as a byssinosis-like disorder. The first cases reported, in which immunologic and challenge tests were used to confirm this association, were described 14 years ago and referred as hypersensitivity pneumonitis nominated as stipatosis. Later, a large number of cases of esparto dust-induced hypersensitivity pneumonitis were reported by different authors, so that esparto may be nowadays considered as the main substance causing extrinsic allergic alveolitis in Spain. Afumigatus has been revealed to be the main inducing cause of stipatosis but probably is not the only one since other microorganisms could be implicated. On the other hand esparto fibers may also cause occupational asthma. In this article the prominent clinical findings of this disease as well as the results of serologic, bronchoalveolar lavage (BAL) and specific inhalation tests are shown. A complete historical review of esparto-induced allergic respiratory disease is also described.

Adult↗
PubMed1996

Hypersensitivity pneumonitis in workers exposed to esparto grass (Stipa tenacissima) fibers.

Esparto grass (Stipa tenacissima), which is commonly found in the Mediterranean countries, has a wide variety of uses. Five stucco makers who had cough, dyspnea, malaise, and fever after exposure to esparto fiber used in their jobs showed a significant decrease in symptoms when they were away from work. Precipitating antibodies against an esparto extract were found in the sera of all patients. Specific IgG antibodies against the esparto extract were also demonstrated in all patient sera, as were IgG antibodies to Aspergillus fumigatus and thermophilic microorganisms (Micropolyspora faeni and Thermoactinomyces vulgaris) by means of an ELISA method. Esparto activity was inhibited in different ranges by the above antigens by inhibition ELISA. Only A. fumigatus could be identified after microbiologic evaluation of the esparto fiber samples. After inhalation challenge tests were performed with esparto extracts, all patients showed significant decreases in forced vital capacity, transfer lung CO, and PaO2 blood gas from baseline values. Fever, chills, malaise, dry cough, tachycardia, tachypnea, and rales on chest auscultation were also observed in all patients. Findings from bronchoalveolar lavage were suggestive of allergic alveolitis. Transbronchial biopsy specimens showed interstitial alveolitis with lymphocyte-macrophage infiltrate and granuloma. Unexposed control subjects did not exhibit reactivity to any of the tests listed above. The dust derived from esparto fibers can cause hypersensitivity pneumonitis in exposed subjects. Organisms such as A. fumigatus and thermophilic actinomyces could be the causative antigens. "Stipatosis" might be an appropriate name for this disorder.

Adult↗