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Biomedical subjects

J Manfreda

Publications and source records attributed to J Manfreda.

At least 55 records · Page 3Linked to original sources
PubMed1995

Mite and cat allergen levels in homes and severity of asthma.

The relationships between mite and cat allergen levels in the home, skin test reactivity, and severity of asthma were explored in 120 asthmatic subjects, 57 in Vancouver and 63 in Winnipeg. Patients in the two cities were similar in age, gender distribution, and severity of asthma. Skin tests were performed using 13 common allergens, including D. pteronyssinus, D. farinae, and cat dander, as well as control subjects. Patients recorded their asthma symptoms, medication requirement, and twice daily peak expiratory flow rate for 1 yr. Dust samples were collected every 3 mo during each season of 1992 through 1993 in both cities. Mite and cat allergen levels were determined with an ELISA using monoclonal antibodies against Der p I, Der f I, and Fel d I. There was no relationship between skin test reactivity and levels of mite and cat allergens. In children with positive skin tests to either mite allergen, total mite (sum of Der p I and Der f I) allergen level was positively related to the mean daily symptom score and negatively related to the daily mean PEF (% of predicted). There was no such relationship among adult asthmatic patients with positive skin tests to either mite allergen. No relationship was found between cat allergen level and the severity of asthma.

Adult↗
PubMed1995

Tuberculosis as a primary cause of respiratory failure requiring mechanical ventilation.

Tuberculosis as a primary cause of respiratory failure requiring mechanical ventilation (TBMV) is an uncommon occurrence. Over a 10 yr period in the province of Manitoba, Canada (population 1,091,942 in 1991), 13 patients with TBMV were identified. Non-drug-resistant M. tuberculosis was isolated from each case. The patients fell into two categories: miliary or disseminated tuberculosis (n = 7) and tuberculous pneumonia (n = 6); eight developed ARDS (adult respiratory distress syndrome) and another two probable ARDS. The hospital mortality for TBMV was compared with that for mechanically ventilated nontuberculous pneumonia and ARDS patients. Hospital mortality for patients with TBMV (69%, nine of 13) was significantly worse than hospital mortality for patients with nontuberculous pneumonia requiring mechanical ventilation (36%, 34 of 94; p < 0.025) and similar to the hospital mortality for patients with ARDS of any cause (56%, 15 of 27; p > 0.10). APACHE II scores for all groups of patients were similar. Compared with patients with tuberculous pneumonia, patients with miliary or disseminated tuberculosis were significantly more likely to develop TBMV (18.9 versus 0.8%, p < 0.0001). Despite the availability of effective antituberculous drugs, TBMV is often associated with ARDS and carries a similarly high mortality rate. Among patients with pulmonary tuberculosis, those with miliary or disseminated disease are especially prone to develop TBMV.

APACHE↗
PubMed1995

Changes in asthma severity in Manitoba.

OBJECTIVE: To assess changes in the severity of physician-diagnosed asthma between 1983 and 1988. DESIGN: Cross-sectional studies examining the frequency of markers of asthma severity: hospitalizations, ICU admissions, hospital emergency department visits, multiple physician contacts, and referrals to specialists in patients aged 0 to 14 years, 14 to 34 years, and > or = 35 years separately. SETTING: Physicians' claims data from the universal Provincial Health Insurance Plan for fiscal years 1983 and 1988. PATIENTS: All patients with the diagnosis of asthma, bronchitis, and COPD identified from the Manitoba Health database. MEASUREMENTS: The markers of severity were related to the prevalence of patients seeing a physician and receiving a diagnostic label of asthma, COPD, or bronchitis. RESULTS: The number of patients with physician-diagnosed asthma increased by 36.4% over the 5 years. In 1983, 11% of asthmatics were hospitalized during the year and 8% were hospitalized in 1988 (-2.5%; 95% confidence interval [CI], -3.2 to -1.8%). During both years, about 75% of the patients hospitalized were in hospital once only. Mean and median duration of hospital stay declined. The percentage of asthmatics seen in the hospital emergency departments declined slightly in all age groups, the total being 21% in 1983 and 18% in 1988 (-3.5%; 95% CI, -4.5 to -2.5%). About one third of the patients with asthma were seen only once by a physician during both of the years examined, 43 to 45% of them being seen on three or more occasions during both years. Referrals to specialists for all asthmatics increased from 12 to 14% (1.9%; 95% CI, 1.0 to 2.8%) from 1983 to 1988. This was almost entirely due to an increase from 11 to 16% (5.1%; 95% CI, 4.0 to 6.2%) in the youngest age group, an increase not accompanied by an increase in any other marker of severity. Changes in asthma severity were similar to changes in the severity in patients with bronchitis and COPD. CONCLUSION: No increase in severity of asthma was seen between 1983 and 1988, but the prevalence of the diagnostic label of asthma increased substantially.

Adolescent↗
PubMed1995

Major cat allergen (Fel d I) levels in the homes of patients with asthma and their relationship to sensitization to cat dander.

BACKGROUND: Exposure and sensitization to the major cat allergen, Felis domesticus allergen I (Fel d I), significant causes of allergic respiratory disease. Many patients who are allergic to cats, however, do not own a cat and there is not an obvious source of allergen in their home environment. OBJECTIVE: We investigated the levels of Fel d I in dust from homes of 120 subjects with asthma in two climatologically diverse Canadian cities (Vancouver and Winnipeg). Fel d I levels were related to exposure to cats as well as to skin reactivity to cat dander. METHODS: Dust samples from bedroom floors and mattresses were collected in four different seasons and Fel d I content was determined by 2-site monoclonal antibody based-ELISA. RESULTS: Although only 18 patients (15%) were cat owners, detectable levels of Fel d I were found on at least one occasion in all homes. The geometric mean concentration of Fel d I on floors was 1.15 micrograms/g of dust (range 0.07 to 26.3 micrograms/g) and on mattresses 0.89 micrograms/g (range 0.01 to 17.4 micrograms/g). Seasonal variation of Fel d I levels was only observed in Winnipeg, where Fel d I concentrations were highest in the winter and spring compared with either summer (P < .05) or autumn (P < .005). The highest Fel d I levels were found in homes with a cat (P < .05), however, rather high levels were also found in homes of patients who did not have a cat but visited others with cats. Cat dander was the most frequent sensitizer (60%) in these patients but no correlation was found between the size of the wheal induced by cat dander extract and Fel d I levels in dust samples. CONCLUSION: Cat allergen was universally found in homes of asthmatic patients and this may explain the high frequency of cat sensitization among patients with asthma in these two cities. A seasonal variation in cat allergen was observed in Winnipeg with no variation in Vancouver.

Adolescent↗
PubMed1993

Antituberculous drug resistance in Manitoba from 1980 to 1989.

OBJECTIVES: To estimate the magnitude of antituberculous drug resistance and identify the risk factors for its development in tuberculosis patients in Manitoba over a 10-year period. As well, to examine the clinical course of the patients whose initial or subsequent isolates of Mycobacterium tuberculosis were resistant to one or more drugs. DESIGN: Comparison of drug-resistant and non-drug-resistant cases of tuberculosis. SETTING: Manitoba. PATIENTS: All people with tuberculosis reported to the Central Tuberculosis Registry of Manitoba between Jan. 1, 1980, and Dec. 31, 1989. MAIN OUTCOME MEASURES: Of 1478 cases of active tuberculosis 1086 were culture positive, and drug susceptibility testing was performed in these cases. The clinical course, including outcome of treatment, of all drug-resistant cases was described. RESULTS: Of 1086 culture-positive cases of tuberculosis 77 (7.1%) were drug resistant. Odds ratios suggested that the risk of drug resistance was significantly higher among the immigrants than among the other Canadians. Compared with the other Canadians the risk of drug resistance was 9.9 times greater among the immigrants in whom tuberculosis developed within the first year after arrival in Canada and 5.4 times greater among the immigrants in whom it developed 2 to 5 years after arrival in Canada. Of the 71 patients with drug-resistant disease whose type of resistance was known 62% had never taken antituberculous drugs before and 38% had. Most (91%) of the 77 cases of drug-resistant disease were resistant to first-line drugs, especially isoniazid and streptomycin. Thirty-two (42%) of the 77 cases were resistant to two or more first-line drugs. Of patients with drug-resistant disease a subgroup of 10 had disease that became resistant to several drugs over the 10-year period. The outcome of treatment in these individuals was poor, and they presented a particular public health problem. CONCLUSION: Resistance to one or more first-line antituberculous drugs continues to complicate the treatment of tuberculosis and may facilitate the spread of the disease.

Adolescent↗
PubMed1993

Recruiting healthy participants for a large clinical trial.

The Lung Health Study (LHS) is a multicenter randomized clinical trial evaluating treatments for the prevention of chronic obstructive pulmonary disease (COPD). Participants are otherwise healthy smokers with borderline abnormal lung function, who are at relatively high risk of developing COPD. LHS recruiting efforts in the city of Winnipeg, Canada, resulted in the screening of 9,062 people (21% of age-eligible smokers) and randomization of 577 participants. Approximately 50% of the screenees were obtained by direct mail with follow-up telephone calls, while another 14% of the screenees were obtained at worksites. Other recruiting methods included use of mass media, passive displays at community events, and interviewer-aided mall recruiting. Screening rates (percent of the total age-eligible population in Winnipeg screened) were inversely related to age, although eligibility rates were directly related to age. Screening rate was inversely related to indicators of socioeconomic status independent of smoking status. However, randomization rates (percent of the age-eligible population which was randomized) were directly related to socioeconomic status, in part because exclusions for medical reasons were also inversely related to socioeconomic status. Eligibility at initial screening was not related to the recruiting method, but the likelihood of randomizing eligible participants was significantly greater at this clinic for those recruited via mass media and workplace screening than for those recruited by direct mail, and significantly less when recruited at community events.

Administration, Inhalation↗
PubMed1993

Two-step tuberculin testing in staff and residents of a nursing home.

This study examined the prevalence and determinants of tuberculin reactors and the booster response in 272 (97%) residents and 218 (69%) staff of an urban nursing home where a case of miliary TB was being investigated. Many subjects were foreign born (56%), and 15% had a history of BCG vaccination (34% of staff). Testing was done with 5 TU PPD-S (Connaught). Those with < 10 mm induration at 48 h were retested at 1 wk. Test sizes > 9 mm were classified positive (reactors). A questionnaire was given to collect information on risk factors for a positive test. Results showed that 28% (36% staff and 22% of residents) of subjects were reactors at the initial test, 6% at the booster test (staff and residents), and 32% at either test (40% staff and 26% residents). BCG (OR 4.8) and foreign birth (OR 1.7) were significantly associated with total reactors. The association with foreign birth was inversely related to the time since immigration. Only BCG was associated with a positive booster test (OR 6.7). Of positive tuberculin reactions in individuals with a history of BCG, 72% were attributed to the vaccine. We concluded that (1) staff as well as residents should be two-step tested when retesting is anticipated; (2) the prevalence of tuberculin reactors is highly related to the prevalence of BCG vaccinees and foreign birth; and (3) chemoprophylaxis is probably not indicated for isolated tuberculin reactors with a history of BCG.

Adult↗
PubMed1993

Trends in physician-diagnosed asthma prevalence in Manitoba between 1980 and 1990.

We attempted to assess recent changes in the prevalence of physician-diagnosed asthma and the possible influence of diagnostic exchange on these trends. The routinely collected data of the provincial Health Insurance Plan (physicians' claims) were used to determine the annual prevalence of physician-diagnosed asthma in Manitoba. Results indicate that the prevalence of physician-diagnosed asthma increased for all age groups in both male and female subjects between 1980 and 1990. The average increases were the highest in the age group 5 to 14 years for both sexes. The average increases varied with age and there were significant differences between the two sexes. There was evidence of increasing diagnostic exchange, that is, a tendency to label patients with asthma instead of alternative diagnoses. This was particularly prominent in those younger than 35 years of age. However, the increased prevalence of physician-diagnosed asthma, even for the younger population, cannot be fully explained by diagnostic exchange.

Adolescent↗
PubMed1992

The natural history of electrocardiographic preexcitation in men. The Manitoba Follow-up Study.

OBJECTIVE: To examine the natural history of preexcitation occurring on the routine electrocardiogram (ECG). DESIGN: A longitudinal cohort study of 3983 originally healthy men followed prospectively for 40 years. SETTING: Free-living (community-dwelling) study members residing predominantly in Canada. PARTICIPANTS: Nineteen male study members with preexcitation occurring during routine examination in the 40-year follow-up of the Manitoba Follow-up Study. MEASUREMENTS: Routinely requested clinical examinations and ECGs, supplemented by information supplied by the study member or his physician. MAIN RESULTS: Ten study members were found to have preexcitation at enrollment, for a prevalence of 2.5 per 1000 (95% CI, 1.2 to 4.6). A delta wave was first detected during follow-up in an additional nine study members. Seventeen of 19 study members did not have the delta wave at some later time, and preexcitation was intermittently present in most of these members. Over time there was a loss of preexcitation, with 15 of 19 study members no longer exhibiting a delta wave by the end of follow-up. Five of 11 study members with symptoms had physician confirmation of an arrhythmia. Fourteen study members remain alive, and none of the five deaths was attributed to preexcitation. CONCLUSIONS: Preexcitation found on routine ECG in our originally healthy male study group did not confer excess morbidity or mortality, even in those study members who developed symptomatic arrhythmias. Most preexcitation was intermittent and disappeared over time.

Adolescent↗
PubMed1992

Regular narrow QRS complex tachycardias in the Manitoba Follow-up Study (1948-88).

OBJECTIVE: To determine the incidence, risk factors and prognosis of regular narrow QRS complex tachycardia (NQT), which develops in the absence of pre-excitation in subjects free from ischemic heart disease in the Manitoba Follow-up Study. DESIGN AND SETTING: The Manitoba Follow-up Study is a longitudinal cardiovascular study of 3983 initially healthy men (primarily living in Canada) followed prospectively for 40 years. Risk factors and prognosis were assessed in a nested case-control study. MAIN RESULTS: Twenty-two individuals were diagnosed with NQT before clinical and/or electrocardiographic manifestation of ischemic heart disease (145,408 person-years of observation). Between the ages of 30 and 80, the incidence of NQT was one per 6000 person-years and increased with age. History of childhood diseases, valvular disease, smoking, elevated blood pressure and body mass index did not increase the likelihood for NQT development. NQT was diagnosed concurrently with a serious noncardiac condition in seven cases; excess mortality resulted as six of these subjects died within one year of NQT diagnosis while only two subjects without concurrent disease at NQT diagnosis died during follow-up. In comparison with 2% of control subjects, 27% of subjects with NQT subsequently developed electrocardiographical evidence of atrial fibrillation (relative risk was 12 with lower 95% confidence limit of 1.8). CONCLUSIONS: NQT in an otherwise healthy individual is a benign condition and increases the likelihood of atrial fibrillation development.

Adult↗
PubMed1991

Impact of human immunodeficiency virus type 1 on tuberculosis in rural Haiti.

We conducted a case-control study to determine the relative and attributable risk of HIV seropositivity for bacillary-positive (smear and/or culture) pulmonary tuberculosis in Haiti. There were 274 patients with tuberculosis and an equal number of control subjects. Antibodies to HIV were present in 67 (24%) patients and eight (3%) control subjects. Odds ratios suggested that the risk of pulmonary tuberculosis was 15.7 times as great (95% confidence interval, 4.8 to 5.0; p less than 0.05) in patients 20 to 39 yr of age who were HIV-seropositive than in HIV-seronegative patients. In contrast, the relative risk in those 40 to 59 yr of age was elevated (3.0 times), though not significantly (lower 95% confidence interval, 0.8). In the 20- to 39-yr age group, 31% of tuberculosis was attributable to HIV infection (95% confidence interval between 23 and 39%). HIV-seropositive and HIV-seronegative patients did not differ with respect to sputum smear positivity. HIV-seronegative patients were twice as likely to be infected with resistant organisms, though this was not significant. We conclude that HIV infection is a major risk factor for pulmonary tuberculosis in young adult residents of Haiti. This, together with the fact that similar proportions of HIV-seropositive and HIV-seronegative patients were potentially infectious, suggests that without vigorous counteraction tuberculosis will become a greater problem for Haiti.

Acquired Immunodeficiency Syndrome↗
PubMed1991

The chest roentgenogram in pulmonary tuberculosis patients seropositive for human immunodeficiency virus type 1.

To determine the impact that co-infection with HIV has on the radiographic presentation of pulmonary tuberculosis, we examined the chest roentgenograms obtained before treatment in 225 HIV-tested adult Haitians with bacillary (smear or culture or both) positive pulmonary tuberculosis. There were 67 HIV-seropositive and 158 HIV-seronegative patients. Intrathoracic adenopathy alone was more common and parenchymal infiltrates less common in HIV-seropositive patients (p less than 0.05). Although a parenchymal infiltrate was less likely to be cavitating in the HIV-seropositive group (p less than 0.05) when cavitary parenchymal disease was present, HIV seropositivity did not affect the number of cavities (single or multiple) or the size of the largest cavity. Patients with AIDS were significantly more likely to have a chest radiographic pattern consistent with primary tuberculosis (80 percent) than HIV-seropositive patients without AIDS (30 percent), and the latter were significantly more likely to have such a pattern than HIV-seronegative patients (11 percent) (p less than 0.05). The HIV-seropositive patients were equally infectious, regardless of the pattern of disease (primary vs postprimary). Even though pulmonary tuberculosis in an HIV-seropositive adult probably results from reactivation of dormant foci or reinfection, the pattern on the chest roentgenogram often suggests primary disease, especially if the patient has AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1991

The impact of HIV on the usefulness of sputum smears for the diagnosis of tuberculosis.

In a developing country, 289 patients were examined for active pulmonary mycobacterial disease (sputum smear and culture) and HIV infection (serology) to compare the sensitivity and positive predictive value of sputum smears for diagnosing pulmonary tuberculosis in patients with and without antibodies to HIV. Seventy-nine percent of HIV-seronegative vs 66% of HIV-seropositive patients with positive cultures for Mycobacterium tuberculosis were smear positive (P less than .05), and a positive sputum smear predicted the presence of M. tuberculosis in 90% of HIV seronegative vs 80% of HIV seropositive patients (P less than .05). In our opinion, HIV did not significantly compromise the diagnostic utility of the sputum smear.

Adolescent↗
PubMed1991

Pulmonary tuberculosis, human immunodeficiency virus type-1 and malnutrition.

In rural Haiti we measured and compared the muscle protein and calorie reserves (anthropometrics) as well as the visceral protein reserves (serum albumin, tuberculin sensitivity) in 56 HIV (human immunodeficiency virus type-1) seropositive and 108 HIV seronegative pulmonary tuberculosis patients. Results in patients were also compared to the results of the same measurements made in 160 age, sex and residence matched HIV seronegative controls without tuberculosis. Tuberculosis patients, regardless of HIV status, had significantly reduced muscle protein and calorie reserves compared to controls. The serum albumin was significantly lower in HIV seropositive tuberculosis patients (21.0 g/l) compared to HIV seronegative tuberculosis patients (26.9 g/l) and the serum albumin in both tuberculosis groups was significantly lower than in controls (41.3 g/l). The lower the serum albumin in the tuberculosis patients the greater the likelihood of a negative tuberculin test. HIV seropositive tuberculosis patients were significantly more likely to be tuberculin negative than HIV seronegative tuberculosis patients. Tuberculosis is associated with significant malnutrition. Worse malnutrition in tuberculosis patients co-infected with HIV suggests that the effect of the two pathogens on nutrition is additive or, alternatively, that tuberculosis patients who are particularly malnourished are at increased risk for HIV.

Adult↗
PubMed1990

Tuberculosis surveillance in immigrants to Manitoba.

Despite a decrease in the incidence of tuberculosis in Canada over the last decade, the proportion of cases in people not born in Canada has increased. To determine the prevalence of active tuberculosis at the first surveillance clinic visit and the incidence of the disease over a 2-year to 6-year follow-up period, we reviewed the records of all 523 immigrants admitted to Manitoba between 1981 and 1985 who were placed under surveillance. Of the 523, 429 (82%) were seen at least once in the clinic. Among the 429, active tuberculosis was diagnosed at the first visit in 12 (3%) and during the follow-up period in 7 (2%). The relative risk of tuberculosis was 4.5 times higher for immigrants under surveillance than for those not under surveillance. Of the 483 immigrants who were to be seen in Winnipeg 232 (48%) were noncompliant: 94 were not seen at any time, and 138 did not attend for the full follow-up period. Active disease was not reported to have developed in any of the noncompliant subjects. Noncompliers were significantly older than compliers (p less than 0.005), and variations in compliance were noted according to region of origin. Further attempts to improve compliance with surveillance without resorting to punitive measures are indicated.

Adult↗
PubMed1990

The association between exercise blood pressure and the prevalence of ECG abnormalities.

The relationship between atrial and ventricular electrocardiographic abnormalities and exercise systolic blood pressure was studied in 246 male and 183 female subjects, of whom 199 males and 158 females were normotensive (resting blood pressure below 140/90 mmHg) and 47 males and 25 females were borderline hypertensive (resting systolic blood pressure 140 to 159 and/or diastolic blood pressure 90 to 99 mmHg). Subjects were classified into three groups according to systolic blood pressure during treadmill exercise (less than or equal to 180 mmHg, 180 to 199 mmHg and greater than or equal to 200 mmHg). With respect to atrial electrocardiographic abnormalities, the prevalence of abnormal values of the P-terminal force in lead V1 increased significantly with increased levels of resting exercise systolic blood pressure in males and females. The prevalence of electrocardiographic left ventricular hypertrophy, as reflected in abnormal values of one or more RS voltage indices, increased significantly with exercise systolic blood pressure in males but not in females. Males did not show a trend of increasing electrocardiographic left ventricular hypertrophy with increased resting systolic blood pressure means. In females, the significant difference between resting systolic blood pressure means and electrocardiographic left ventricular hypertrophy did not reflect a linear progression across resting systolic blood pressure categories. The significant association of the P-terminal force in lead V1 with exercise systolic blood pressure has not previously been reported. Although an association between left ventricular hypertrophy and exercise systolic blood pressure in hypertensives has been reported by others, the association seen in normotensive and borderline hypertensive males has not been reported previously.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Chronic respiratory disorders related to farming and exposure to grain dust in a rural adult community.

In a survey of chronic respiratory symptoms and airflow obstruction of a rural population aged 20-65 years, the effects of both farming and, in particular, the exposure to grain dust on the respiratory health of the people was examined. Of the 1,892 subjects (82% of the eligible population) studied, 924 were males and 968 females, with half living in the town. Three groups were identified: current, former, and never farmers. Almost all current farmers were exposed to grain for, on average, 2 months a year. There was no difference in atopic status between the groups. While there was a strong association between most symptoms and smoking, there was no association between symptoms and exposure to grain and farming category once age and smoking had been taken into account. Results of this study suggest that farmers do not have chronic respiratory symptoms or impairment of lung function because of their exposure to grain dust. Lung function of former farmers might have been affected by farming, and this may reflect more involvement with livestock in the past.

Adult↗