Biomedical subjects
Publications and source records attributed to C Nair.
Severe trauma to the liver and juxtahepatic cava require vascular isolation of the lesion. In addition to the techniques of vascular clamping and atriocaval shunting, venovenous bypass is a viable alternative to repair such injuries. We herein report its use in five consecutive patients. The technique obviates the hemodynamic sequelae of uncompensated caval occlusion and the technical dangers of atriocaval shunting.
Thirty-four patients with chronic myeloid leukemia in blast crisis (CML-BC) were evaluated for lineage differentiation with immunological markers and the presence of ultrastructural peroxidase. Eighteen (52.9%) were found to have myeloid blast crisis. Cytochemically, myeloperoxidase (MPO) could be detected only in six patients on light microscopy while in the remaining 12 patients, myeloid differentiation was confirmed only by demonstration of MPO either at ultrastructural level or by the reactivity with anti myeloperoxidase (anti MPO) antibody. Six (17.6%) had lymphoid blast crisis as identified by lymphoid specific markers (CD19; CD10; CD7; CD4) along with the absence of myeloid markers. Heterogenous blast cell populations with mixed lineage differentiation were seen in 4 (11.7%) patients. These cases showed both lymphoid (CD19, CD10) and myeloid (anti MPO and ultrastructural MPO) characteristics. A single case of megakaryoblastic blast crisis was identified with positivity for CD41 and CD42 along with the presence of platelet peroxidase at the ultrastructural level. Five cases (14%) of CML blast crisis remained unclassifiable. These results suggest that blast crisis in CML show an arrest of differentiation at an early stage when compared to de novo acute leukemias. This is particularly evident from the fact that MPO could only be demonstrated ultrastructurally or with anti MPO antibody in the majority of patients with myeloid differentiation. It is expected that utilisation of molecular studies including immunoglobulin and T-cell receptor gene rearrangement and m-RNA expression for myeloperoxidase will provide a better insight into the level of differentiation for the presently unclassifiable cases of CML-blast crisis.
A total of 25 patients with primary myelodysplastic syndrome (p-MDS) were cytogenetically investigated. The incidence of abnormal karyotypes was higher, detected in 88 per cent of the patients and the most frequent abnormality was a terminal deletion of chromosome 7 (45% of the patients with abnormal karyotypes) followed by an i (17q) (18%), +21(14%), -5/5q (9%), del (11) (q22) (9%). Cytogenetic analysis after therapy/after leukaemic transformation indicated either stable clones (2 patients) or emergence of new clones such as inv(5) (q32q36), del (17) (p13), +20, +22 (1 patient each). It is to be noted that of the 8 patients with leukaemic transformation, 5 had del (7q). The leukaemic transformation (32% of the patients) was not related to the percentage of abnormal karyotypes not to the percentage of blasts at the time of the MDS presentation. Chromosome instability was shown by 10 (45%) patients. Our data indicate that higher frequency of chromosomal aberrations with involvement of chromosome 7 may be the result of underlying disease.
Hospital morbidity data are useful for administrative purposes, but because Canadian data are based on the number of hospital visits for a given diagnosis rather than the number of patients with the diagnosis, they have historically been ineffective in determining how many people have been hospitalized with a given condition. Now, by linking computerized patient data, the records of the same patient can be combined. Linked records can be used to estimate disease prevalence, examine health care utilization, and evaluate the effectiveness of medical treatments, procedures and programs. Hospital morbidity records for the fiscal year 1989/90 were linked by person to study hospital utilization in New Brunswick and Saskatchewan. Approximately 11% and 12% of their populations, respectively, were admitted to hospital in the study period. The percentage of the population that was hospitalized increased with age from 50 onwards. About one in four hospital patients were admitted to hospital more than once in 1989/90, and approximately 4% were admitted four or more times. Cancer diagnoses were associated with the highest hospital re-admission rates. About half of hospitalized patients spent five days or less in hospital over the period studied. At the other extreme, 10% of patients, referred to as "high users," accounted for about half of the hospital days--but only 1% of the population in these two provinces. Typically, high users are patients with chronic conditions or illnesses severely affecting cognitive or physical abilities. This profile of high users suggests that high medical costs are due not so much to intensive care of terminally ill patients, but to ordinary medical and palliative care of chronically and seriously ill patients. Restructuring health care data so that all of the records for one patient could be linked would help identify problem areas in the health care system and help evaluate new ways of delivering health care.
In Canada in 1991, about 15,000 persons died from cerebrovascular disease, a figure that represented 7% of all deaths. Currently, cerebrovascular disease accounts for over 67,000 hospital discharges and 3.2 million days of hospitalizations per year. This paper examines the declining trends in stroke mortality from 1951 to 1991, by age and sex. Comparisons of mortality rates by income quintiles and cohort effects are discussed. By comparison with other countries, Canada has one of the lowest rates of death from cerebro-vascular disease. With an aging population, the burden of stroke measured in terms of death, disability and health care costs, remains a major challenge for preventive and health care policy.
This article presents an overview of health care systems in Canada and selected OECD countries (Australia, France, Finland, Germany, Sweden, the United States and the United Kingdom). The article discusses the organization of health care systems, health care expenditure, the availability and utilization of health services, and the health status of the population. In addition, it highlights and compares key health care indicators that are common to all health care systems. The article focuses on the relationship between health expenditure and health status in terms of life expectancy and infant mortality and shows that the United States had the highest infant mortality and second lowest life expectancy for females at birth in 1990 while it spent the most on health care as percentage of GDP. The article also shows that the overall health status indicators in some countries such as Finland and Sweden are comparable to that of Canada despite spending considerably less on health care.
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We report the cytogenetic findings of 100 patients with chronic myeloid leukemia (CML) [72 patients in chronic phase (CP) and 28 patients in blastic phase (BP)]. Of the 95 Ph + patients, six had Ph variant translocations involving chromosomes 1, 6, 7, 10, and 12. The percentage frequency of patients with chromosomal changes other than Ph was 7.3%. The additional aberrations (e.g., + Ph, + 8, i(17q), and + 19 were observed in 66.6% of BP patients. Of these anomalies, the frequency of + Ph and + 19 was higher in our patients than the incidence reported in literature. The association of + Ph and + 19 in patients with extramedullary T-cell blast crisis is an unusual finding as compared with reports in the literature and could be explained by geographic heterogeneity. The extra chromosomal abnormalities were almost absent in lymphoid blast crisis patients with blast phenotype of common acute lymphoblastic leukemia (ALL) type. Discrepancies were noted in different tissues (bone marrow and lymph node) in patients with extramedullary blast crisis of both myeloid and lymphoid type. These findings indicate the cytogenetic correlation with clinical and morphological picture, which consequently implicates the diagnostic and prognostic significance of chromosomal aspects.
Recent trends in cesarean section deliveries in Canada were explored using 1970-1988/89 hospitalization data from Statistics Canada's morbidity data base. The rate in Canada increased from 5.8 cesarean sections per 100 hospital deliveries in 1970 to 19.5 in 1988/89 and paralleled the increase in rates seen in the United States, which went from 5.5 to 24.7 during the same period. Canada had the second highest rate among the countries studied and in the last year of the study the Canadian rate was almost double that of the United Kingdom. Provincially the rates were highest in Newfoundland (23.3) and lowest in Manitoba (15.5). Cesarean sections were more frequent among women aged 35+ (27.3 per 100 hospital deliveries) compared with (13.9) for women under 20 years of age. Vaginal births after a previous cesarean increased significantly during the last 10 years from 3 per 100 previous cesarean sections in 1979/80 to 15.6 in 1988/89, perhaps indicating a significant shift in obstetric practice.
This paper reports preliminary and selected results of an analysis of the frequencies of 36 common surgical procedures in hospitals across Canada during the period April 1985 to March 1987. Age-sex-specific and age-sex-standardized procedure rates were calculated for each procedure for each of 245 Census Divisions (CDs) across Canada, as well as for 338 smaller urban areas (FSAs) within the province of Ontario. Special attention was given to adjusting the rates for differing population sizes of the geographical regions. Procedure rates were computed based on the residence of the patient, not on the location of the hospital. Graphical techniques, analysis of variance, and other statistical techniques were used to identify unusually high or low procedure rates and to determine effects due to differences in age, sex, and geographical region. The relationship of procedure rate to the socio-economic level of a region (as measured by the proportion of low-income individuals in the region) was analyzed.
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This article examines suicide mortality rates and trends in Canada for first-generation immigrants and the Canadian-born population. Data are analyzed by age, sex and country of birth. Since 1950, suicide rates worldwide for both men and women have been increasing. In North America and most of Europe, suicide has been one of the major causes of death for many years. In Canada, suicide rates are also rising. However, this increase is due entirely to a rise in the rate for men; the rate for women has remained relatively stable. Several differences are apparent between the rates for the Canadian-born population and those for first-generation immigrants. For example, three times as many Canadian-born men as women commit suicide. For first-generation immigrants, the ratio is two to one. Suicide mortality rates for the Canadian-born are higher than those for first-generation immigrants in every age group except for the 65 and over groups. Canadian born males have higher ASMR than first generation immigrant males. The rates for women show that first-generation immigrant women have higher suicide mortality rates than their Canadian-born counterparts, and that the highest rate for all women is for immigrants born in Asia.
Cardiovascular disease (CVD) is the major cause of death in Canada, as it is in most industrialized countries. Studies have shown that CVD mortality rates vary among ethnic groups. Since about one in six Canadian residents is a first generation immigrant, it is important to consider ethnic background when interpreting Canadian health statistics or planning health services. Overall, lower CVD mortality rates were found for first generation Canadians from Latin America, China and South Asia; higher rates are indicated for those from Scandinavia and Africa. The rates for North America are similar to those found for Eastern and Western Europe. Between two five-year time periods (1969-73 and 1984-88), CVD mortality rates generally were found to decrease, except for immigrants from Africa (age 35+). The rates were consistently higher for males than for females.
This report examines trends in the number and the rates of coronary artery bypass surgery (CABS) in Canada, performed over a six-year period from 1981-82 to 1986-87. The analysis includes comparisons of rates and events by sex, age and geographic location. In Canada 10,865 CABS were performed in 1986-87 representing a 39% increase over 1981-82. During the same period the rate of CABS rose to 43.2 per 100,000 population. In the twelve census metropolitan areas (CMAs) covered in this study, CABS increased 45.7% from 6,477 in 1981-82 to 9,439 in 1986-87, while hospital separations for Ischemic Heart Disease (IHD) increased by 22.6%. Regionally the coronary artery bypass surgery rate was lowest in Halifax at 62.4 per 100,000 population and highest in Ottawa-Hull at 131.8 per 100,000 population. The average annual proportion of CMAs ranged from 15.5% for residents in Halifax (84.5% for non-residents) to a high of 65.7% for residents in Montreal (34.3% for non-residents). Procedure rates increased consistently among the 65-74 and 75+ age groups, remained stable in the 55-64 age group, and decreased in the 35-54 age group. The variations among the CMAs may in part be due to the amount of resources available in each CMA, the demand for this type of service and perhaps to differing patterns of physician practice.
Since the first national mortality statistics were published in 1921, cardiovascular disease (CVD) has been the leading cause of death in Canada, accounting for almost half of all deaths each year. In 1987, more than 77,000 Canadians died from CVD, almost 60% more than cancer, the second leading cause of death. The costs of CVD are high in economic as well as human terms. CVD accounts for 21% of all hospital days and is responsible for 25% of all disability pensions paid by the Canadian Pension Plan before age 65. CVD hospital costs alone, excluding doctors' fees and costs of surgery, exceed $3 billion annually. Not all the news about CVD is bad, however. Overall CVD incidence has been steadily declining since the early 1950s, and since 1979 the total number of CVD deaths has actually been decreasing, despite a growing and aging population. Improved survival rates are probably the result from more widespread use of advanced surgical technology during the acute phases of heart attacks, and better medical care for people who survive heart attacks. As this paper shows, CVD incidence varies by sex, age, region, and socio-economic status, as does the prevalence of controllable factors that increase the risk of CVD. These risk factors include smoking, high blood pressure, overweight, lack of physical activity, high levels of dietary fat, and elevated cholesterol levels. Lowering CVD rates to those of nations such as Japan and France, both with less than half the Canadian rate, requires increased public awareness of the dangers of the 'typical' Canadian lifestyle. At the same time, lower-income Canadians, the group with the highest CVD rates, must be given increased opportunities to make healthy lifestyle choices.
The blast cell population of 60 patients with chronic myeloid leukaemia in blast crisis (CML-BC) were analyzed with a panel of monoclonal antibodies to determine the cell surface antigen phenotypes. In addition, cytochemical stains periodic acid Schiff (PAS), myeloperoxidase (MP), Sudan black B (SBB) and terminal deoxynucleotidyl transferase (TdT) were also utilized for subtyping. Nineteen cases (31.6%) expressed lymphoid phenotypes characteristic of common ALL cells and one case with extramedullary lymph node crisis expressed T-cell surface phenotypes. Thirty cases (50%) expressed solely myelomonocytic surface antigens with significant TdT activity in three. Cytochemical stains contributed to recognize only 57% of these myeloid blasts. Seven cases (11.7%) were with a mixture of heterogenous group of cells expressing phenotypic characteristics for various haemopoietic cells of different lineage--five of them from the cells of non-lymphoid series (myelomono-erythromegakaryocytic series) and the other two with cells from both lymphoid and myeloid series. Additionally, in two cases (3.3%), the precursor cells reacted only with the erythroid monoclonals. Finally, in one case, the blast cells remained unclassified due to nonreactivity with any of the monoclonals used but expressed significant TdT positivity. The response to uniform vincristine and prednisolone (V + P) therapy has shown that lymphoid blast crisis cases were highly responsive in contrast to the cases with non-lymphoid blast crisis (complete remission rate 86 vs 21.4%). The results confirm the evidence of multilineage blast crisis involving either single or mixed haemopoietic differentiation pathway and the utility of having phenotypic characterisation for designing protocols for chemotherapy in the CML patients at the time of blast crisis.
Twenty-one percent of all Hodgkin's disease in India was seen in the pediatric age groups at the Tata Memorial Hospital (Bombay, India). From 1975 to 1982, 151 cases of children were reviewed. The youngest presentation was at 3 years in three patients, with a marked male: female ratio of 5.5:1. Twenty-six patients were previously treated before referral while the remaining 125 cases were investigated and treated according to the prevalent protocols in 1975 to 1978 and 1979 to 1982. Clinical staging revealed 54% of patients in stages I and II with symptoms in 20%, and 46% of patients in stages III and IV with symptoms in 67%. Staging laparotomy was performed in 27 patients, with a total changes of staging in 17 children (63%). The mixed cell types (46%) and lymphocytic predominant types (31%) were the most common histologic presentations. Nine percent nodular sclerosis and 9% lymphocytic-depleted varieties were also observed. Five percent of all cases were not classifiable. Minimum adequate treatment was completed in 87 cases. Comparisons were made between the treatments administered to 40 patients during the initial period 1975 to 1978 when individualized treatment was administered, and the later 47 patients during the 1979 to 1982 period, when chemotherapy was the mainstay of treatment with involved field radiation.
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