A simple approach to assess VT during a field walk test.

We aimed to examine whether the ventilatory threshold (VT) during an incremental shuttle walk test (ISWT) could be determined using heart rate variability (HRV) analysis. Further aims were to assess variables capable of predicting performance in the ISWT and the intensity of this test. Beat-to-beat RR intervals and gas exchange values in 10 healthy subjects (31-83 years; 7 men) were collected during the ISWT. The ventilatory equivalent was used to assess VT from respiratory components. To determine the HRV threshold (HRVT), the instantaneous beat-to-beat variability values of the RR intervals at each stage of exercise were graphically plotted against walking speed (WS). The oxygen consumption at HRVT was calculated (VO2HRVT). No significant differences were found between walking speed (WS) at VT and WS at HRVT (5.04±1.00 vs. 5.10±1.04 km/h; p=0.89). Linear regression analysis revealed a strong correlation between VO2VT and VO2HRVT (r(2)=0.896). The Bland and Altman plot analysis revealed an agreement between VO2VT and VO2HRVT (-0.05; 95%CI: -0.30-0.20 L/min). Thus, the VT can be assessed during the ISWT using a simple heart monitor. The ISWT may be a useful tool to assess exercise capacity and prescribe walking programs.

Chronic granulomatous disease. Report on a national registry of 368 patients.

A registry of United States residents with chronic granulomatous disease (CGD) was established in 1993 in order to estimate the minimum incidence of this uncommon primary immunodeficiency disease and characterize its epidemiologic and clinical features. To date, 368 patients have been registered; 259 have the X-linked recessive form of CGD, 81 have 1 of the autosomal recessive forms, and in 28 the mode of inheritance is unknown. The minimum estimate of birth rate is between 1/200,000 and 1/250,000 live births for the period 1980-1989. Pneumonia was the most prevalent infection (79% of patients; Aspergillus most prevalent cause), followed by suppurative adenitis (53% of patients; Staphylococcus most prevalent cause), subcutaneous abscess (42% of patients; Staphylococcus most prevalent cause), liver abscess (27% of patients; Staphylococcus most prevalent cause), osteomyelitis (25% of patients; Serratia most prevalent cause), and sepsis (18% of patients; Salmonella most prevalent cause). Fifteen percent of patients had gastric outlet obstruction, 10% urinary tract obstruction, and 17% colitis/enteritis. Ten percent of X-linked recessive kindreds and 3% of autosomal recessive kindreds had family members with lupus. Eighteen percent of patients either were deceased when registered or died after being registered. The most common causes of death were pneumonia and/or sepsis due to Aspergillus (23 patients) or Burkholderia cepacia (12 patients). Patients with the X-linked recessive form of the disease appear to have a more serious clinical phenotype than patients with the autosomal recessive forms of the disease, based on the fact that they are diagnosed significantly earlier (mean, 3.01 years of age versus 7.81 years of age, respectively), have a significantly higher prevalence of perirectal abscess (17% versus 7%), suppurative adenitis (59% versus 32%), bacteremia/fungemia (21% versus 10%), gastric obstruction (19% versus 5%), and urinary tract obstruction (11% versus 3%), and a higher mortality (21.2% versus 8.6%).

The structure of DSM-IV alcohol dependence in a treatment sample of Mexican and Mexican American men.

AIMS: To examine the symptom profile and factorial structure of DSM-IV alcohol dependence. DESIGN: Subjects were interviewed in program facilities by trained interviewers using a standardized questionnaire. The response rate was 95% in Mexico and 90% in the United States. SETTING: Two publicly funded inpatient facilities in Mexico and five in the United States. In Mexico the programs were located in Mexico City. In the United States the programs were located in Santa Clara County, California. PARTICIPANTS: Three hundred and ninety-one Mexican and 212 Mexican American men in treatment for alcohol problems in Mexico and the United States. MEASUREMENT: Dependence criteria were assessed with the Composite Diagnostic Interview-Substance Abuse Module (CIDI-SAM). FINDINGS: The unidimensional structure of alcohol dependence fits the Mexican American data but not the Mexican data. However, when Mexican clients were divided according to place of interview (treatment program), the unidimensional structure fits one of the groups but not the other. CONCLUSIONS: The test of unidimensionality must be seen as inconclusive with regard to the Mexican data. These results highlight the potential influence that client selection methods may have on study results, especially in cross-cultural projects.

Epidemiologic status of drug abuse in Mexico.

Abuse of alcoholic beverages and tobacco appear to constitute priority public health problems in Mexico, while abuse of other drugs is sufficiently widespread to justify concern. More specifically, a recent national survey (11) found that over 10% of the male subjects 18 to 65 years old met established international criteria for alcohol dependence, while about a quarter of those surveyed were active smokers. A total of 4.3% said they had used one or more drugs other than tobacco or alcohol at some time in their lives.

[Epidemiological status of drug abuse in Mexico]. / Situación epidemiológica del abuso de drogas en México.

As a country that produces marijuana and opium, and as a route for cocaine traffic to the United States of America, Mexico is experiencing serious social and health problems related to the trafficking, use, and abuse of these drugs and other dependency-producing substances. In 1988 a national survey of addiction was undertaken in which information was collected on the prevalence of the use of alcohol, tobacco, inhalants, marijuana, cocaine, hallucinogens, opium, heroin, narcotic analgesics, sedatives, and tranquilizers. A sample was identified in the population between the ages of 12 and 65 living in urban areas of more than 2,500 inhabitants, which account for approximately 65% of the country's total population. This sample consisted of 12,557 persons. According to the results of the survey, 51% of the population between 18 and 65 years of age use alcoholic beverages and 24.7% of the entire study population are active smokers. In addition, 43% had used one or more drugs other than tobacco or alcohol at some time. Prevalence of marijuana use was 2.6%, while the rates for tranquilizers, inhalants, and amphetamines were identical (0.7%). For cocaine the rate was 0.3%, and for heroin, 0.1%.

Situación epidemiologica del abuso de drogas en México / Epidemiological status of drugs abuse in México

As a country that produces marijuana and opium, and as a route for cocaine traffic to te United States of América, México is experiencing serious social and health problems related to the trafficking, use and abuse of these drugs, and other dependency-producing substances. In 1988 a national survey of addiction was undertaken in which information was collected on the prevalence of the use of alcohol, tobacco, inhalants, marijuana, cocaine, hallucinogens, opium, heroin, narcotic analgesics, sedatives and traquilizers. A sample was identified in the population between the ages of 12 and 65 living in urban áreas of more than 2,500 inhabitants, which account for approximately 65 percent of the country's total population. This sample consisted of 12,557 persons, according to the results of the survey, 51 percent of the population between 18 and 65 years of age use alcoholic beverage and 24.7 percent of the entire study population are active smokers. In addition, 43 percent had use one or more drugs other than tobacco or alcohol at some time. Prevelence of marijuana use was 2.6 percent, while the rates for tranquilizers, inhalants, and amphetamines were identical (0.7 percent). For cocaine the rate was 0.3 percent, and for heroin 0.1 percent

Situación epidemiológica del abuso de drogas en México / Epidemiological status of drugs abuse in Mexico

As a country that produces marijuana and opium, and as a route for cocaine traffic to te United States of America, Mexico is experiencing serious social and health problems related to the trafficking, use and abuse of these drugs, and other dependency-producing substances. In 1988 a national survey of addiction was undertaken in which information was collected on the prevalence of the use of alcohol, tobacco, inhalants, marijuana, cocaine, hallucinogens, opium, heroin, narcotic analgesics, sedatives and traquilizers. A sample was identified in the population between the ages of 12 and 65 living in urban areas of more than 2,500 inhabitants, which account for approximately 65 percent of the country's total population. This sample consisted of 12,557 persons, according to the results of the survey, 51 percent of the population between 18 and 65 years of age use alcoholic beverage and 24.7 percent of the entire study population are active smokers. In addition, 43 percent had use one or more drugs other than tobacco or alcohol at some time. Prevelence of marijuana use was 2.6 percent, while the rates for tranquilizers, inhalants, and amphetamines were identical (0.7 percent). For cocaine the rate was 0.3 percent, and for heroin 0.1 percent

Epidemiologic status of drug abuse in Mexico

The contents of this special issue were also published in Spanish in the Boletín de la Oficina Sanitaria Panamericana Vol. 107, N0. 6, 1989