Total occlusion of the left main coronary artery in a Hong Kong Chinese

Total occlusion of the left main coronary artery (LMCA) is a rare finding in patients with stable angina pectoris. To the best of our knowledge, it has not been described in Hong Kong Chinese before. In this paper, we report the clinical and angiographic findings of a Hong Kong Chinese with this condition treated in our unit.

Restrictive cardiomyopathy and constrictive pericarditis: non-invasive distinction by digitised M mode echocardiography

It is difficult to distinguish between restrictive cardiomyopathy and constrictive pericarditis on the basis of clinical findings and simple investigation. Cardiac catheterisation has been the reference standard for diagnosis but even this does not always permit an accurate distinction. A Summagraphics digitiser and Prime 750 computer system were used to digitise the echocardiograms of 15 patients with restrictive cardiomyopathy, 10 with constrictive pericarditis and a group of 20 age and sex matched normal subjects of similar age and sex distribution. Compared with controls, patients with restrictive cardiomyopathy showed a significant reduction in the following variables (a) decreased fractional shortening, (b) decreased peak left ventricular filling and emptying rates, (c) decreased percentage posterior wall thickening, and (d) decreased peak left ventricular posterior wall thickening and thinning rates. Whereas patients with constrictive pericarditis only had significantly reduced peak left ventricular filling and posterior wall thinning rates and significantly increased posterior wall thinning rate. When patients with restrictive cardiomyopathy were compared with those with constrictive pericarditis the significant differences were: (a) decreased peak left ventricular emptying rate, (b) decreased percentage posterior wall thickening, and (c) decreased peak left ventricular posterior wall thickening and thinning rates. Digitisation of M mode echocardiograms, with particular attention to posterior wall function, may be a useful adjunct to cardiac catheterisation in distinguishing restrictive cardiomyopathy from constrictive pericarditis.

Correlates of cervical cytologic screening

We investigated factors associated with the frequency of Papanicolaou cytologic screening among women between the ages of 20 and 54 years in metropolitan Atlanta. In a sample of 393 women who had not had a hysterectomy, the frequency of screening was uniformly high for women aged 20 to 49 years, but declined for women aged 50 to 54 years. Low household income and low gravidity were associated with less frequent screening among whites, but low income and low gravidity correlated positively with the frequency of screening among blacks.

Maternal cigarette smoking and tubal pregnancy

As part of a case-control study of tubal pregnancy, we sought to evaluate the potential etiologic role of maternal cigarette smoking. Between 1975-1979, 192 women who were treated for a tubal pregnancy in five Seattle hospitals were interviewed with regard to smoking habits and reproductive, contraceptive, and medical histories. For comparison, 459 Seattle-area women who delivered during the same period were also interviewed. Current cigarette smokers had a more than twofold increase in risk of tubal pregnancy (adjusted relative risk 2.2; 95% confidence interval 1.4-3.4) when compared with women who had never smoked. The risk for women who had stopped smoking before conception was 1.6 (95% confidence interval 1.0-2.8). There was no consistent trend between the risk of tubal pregnancy and the duration of smoking, average number of cigarettes smoked per day, age at which a woman began to smoke, pack-years of cigarettes smoked, or (among former smokers) the recency of smoking. Although several sources of bias in the present study may have created a spurious association between cigarette smoking and the occurrence of tubal pregnancy, it could well be that an increased risk of tubal pregnancy is yet another untoward consequence of cigarette smoking.

Sexually transmitted diseases and the risk of tubal pregnancy

Women who were hospitalized for tubal pregnancy in five hospitals in King County, Washington, between 1975 and 1979 were interviewed regarding a prior history of gonorrhea, genital herpes, genital warts and trichomoniasis. Their responses were compared to those of women who delivered a live-born child during the same period. Multiple logistic regression was used to control for the effects of race, gravidity, smoking, Dalkon Shield use, douching, number of sexual partners and history of additional sexually transmitted diseases. The risk of tubal pregnancy in women who reported a history of gonorrhea, relative to that in other women, was 5.1. As compared to controls, women with tubal pregnancy more often reported a history of genital herpes and a history of trichomoniasis.

Does prior infertility increase the risk of tubal pregnancy?

One hundred forty-nine patients who underwent surgery for tubal pregnancy at five hospitals in Seattle (WA) between 1975 and 1979 were interviewed to determine the risk factors for this disorder. Their responses were compared with those of 706 control women who had conceived an intrauterine pregnancy during the same time period during which the tubal pregnancies occurred. A higher proportion of cases reported a history of infertility (attempt to conceive without success for a period of at least 1 year) than controls (relative risk [RR] = 2.5; 95% confidence interval [CI] = 1.7-3.7). Women who were diagnosed in the investigation of their infertility as having tubal or ovulatory dysfunction had relative risks of tubal pregnancy of 5.8 (95% CI = 2.1-16.4) and 3.4 (95% CI = 1.3-8.5), respectively. The average time over which subjects had attempted to conceive before index pregnancies that were planned was longer among cases (15.4 months) than among controls (6.9 months). These results support the hypothesis that a history of infertility predisposes women to an increased risk of tubal pregnancy. The authors also found that, among infertile women, about twice as many cases (14.3%) as controls (6.8%) were current fertility drug users (RR = 3.1; 95% CI = 1.1-9.1), which suggests that the use of fertility drug(s) may further increase the risk of tubal pregnancy.

Decline in the incidence of carcinoma in situ of the cervix

Temporal trends in the incidence of carcinoma in situ of the uterine cervix were evaluated in metropolitan Atlanta between 1975 and 1983. The average annual age-adjusted incidence rates per 100,000 women decreased from 61.5 in 1975-77 to 40.1 in 1981-83 for Whites and from 118.3 to 51.8 for Blacks during the same time periods. The relative declines were uniform across all age groups and exceeded the corresponding reductions in the incidence of invasive cervical carcinoma.

IUD use and subsequent tubal ectopic pregnancy

As part of a case-control study of tubal ectopic pregnancy (TEP), we sought to evaluate the possible etiologic role of use of an intrauterine device (IUD) prior to conception. We interviewed 155 women who had a tubal ectopic pregnancy treated at one of five Seattle, Washington hospitals between 1975-79 regarding their reproductive, contraceptive, and medical histories; 456 women who delivered a baby in King County during the same period were identified from vital records and interviewed as controls. An elevated risk of TEP was detected among former users of the Dalkon Shield (adjusted OR = 2.5; 95% CI = 1.3-4.7). Women who had used other IUDs did not have an excess risk of TEP.

Vaginal douching as a potential risk factor for tubal ectopic pregnancy

The incidence of ectopic pregnancy in the United States has more than doubled in the past decade. Because a previous study has suggested that the practice of vaginal douching may increase the risk of pelvic inflammatory disease, a condition known to predispose to ectopic pregnancy, and because the sale of commercial douching products in the United States has more than tripled since 1974, we investigated this practice as a possible risk factor. We interviewed 155 women who had a tubal ectopic pregnancy treated at five Seattle hospitals between 1975 and 1979 as to their reproductive, contraceptive, and medical histories, demographic characteristics, and personal hygiene practices. During the same period, 456 women who were delivered of a baby in King County were identified from Vital Records and interviewed as controls. A higher proportion of cases than controls reported ever having douched in the past. Cases also douched more frequently than controls. After simultaneous adjusting for confounding factors in our data by means of a multiple logistic regression technique, the risk of tubal ectopic pregnancy for women who douched at least weekly was twice that of women who never douched (95% confidence interval = 1.03 to 4.00). The risk for women who used commercial douches on a weekly basis was 4.4 (95% confidence interval = 1.6 to 12.7) the risk for women who never douched.

Primary tubal infertility in relation to the use of an intrauterine device

Women who use an intrauterine device (IUD) are at increased risk of acute pelvic inflammatory disease, but the relation of the IUD to subsequent infertility is not established. We interviewed 159 nulligravid women with tubal infertility to determine their prior use of an IUD. Their responses were compared with those of a matched group who conceived their first child at the time the infertile women started trying to become pregnant. The risk of primary tubal infertility in women who had ever used an IUD was 2.6 times that in women who had never used one (95 per cent confidence interval, 1.3 to 5.2). The observed difference between cases and controls was not uniform for different types of IUD. The relative risk associated with use of a Dalkon Shield was 6.8 (1.8 to 25.2), and that associated with use of either a Lippes Loop or Saf-T Coil IUD was 3.2 (0.9 to 12.0). The smallest elevation in risk was found among users of copper-containing IUDs (relative risk, 1.9 [0.9 to 4.0] for all women who had ever used a copper-containing IUD). The relative risk for women who used only a copper-containing IUD was 1.3 (0.6 to 3.0). We conclude that use of the Dalkon Shield (and possibly of plastic IUDs other than those that contain copper) can lead to infertility in nulligravid women.

Ectopic pregnancy in relation to previous induced abortion

Women who were hospitalized for ectopic pregnancy in five hospitals in King County, Washington, were interviewed concerning history of induced abortion. For comparison, women who delivered a live-born child during this same time period were also interviewed. Relative to women who had never undergone an abortion, the risk in those who had was increased to a modest degree, but this increase could well have been the result of chance (relative risk, 1.4; 95% confidence interval, 0.7 to 2.6). For women who had two or more abortions, the relative risk was 1.8 (95% confidence interval, 0.5 to 7.1). Our results suggest that legal abortion as performed during the past decade in the United States does not carry a large excess risk for future ectopic pregnancy, but larger studies will be needed in order to determine more precisely the magnitude of any excess that does exist.

Control definition in case-control studies of ectopic pregnancy

In case-control studies of ectopic pregnancy, the optimal sampling frame for control selection is influenced heavily by the hypothesis being tested. The selection of women completing an intrauterine pregnancy, a common choice for a control group in studies to date, is appropriate only if the hypothesis does not relate to exposures that selectively prevent an intrauterine pregnancy (e.g., use of an intrauterine device (IUD) at the time of conception). Even for other exposures, the selection of such women can yield misleading results if the exposure is related to the likelihood of completion of the intrauterine pregnancy. On the other hand, the selection of nonpregnant women as controls, while permitting a valid evaluation of the risk associated with exposure such as the use of an IUD, can introduce a substantial degree of incomparability between cases and controls with regard to other contraceptive practices and their correlates. Whichever of the two sampling frames that is chosen, an appreciation of these potential biases can lead to ways of tailoring the selection of individual controls to minimize the magnitude of the bias.

Cholecystectomy and the incidence of cancer of the large bowel

As part of an epidemiologic study of cancer of the large bowel in women, female residents of King and Pierce counties (Washington) who were diagnosed during 1976--77 were interviewed regarding previous gallbladder surgery. Their responses were compared with those of a random sample of women from the same population. A history of cholecystectomy was somewhat more frequent among patients with colon cancer than among controls--we estimate the colon cancer risk in women without a gallbladder to be 1.4 times that of other women--but the 05% confidence limits of the relative risk included 1.0 (0.8--2.5). There was no association between cholecystectomy and rectal cancer and, among the subsites of colon cancer, the magnitude of the excess risk failed to show any consistent right--left gradient. Nonepidemiologic data suggest that cholecystectomy could increase the risk of colon cancer. However, if such an association truly exists it is not a strong one, and studies larger than those conducted to date are needed to detect this association reliably.

Cholecystectomy and the incidence of cancer of the large bowel

As part of an epidemiologic study of cancer of the large bowel in women, female residents of King and Pierce counties (Washington) who were diagnosed during 1976--77 were interviewed regarding previous gallbladder surgery. Their responses were compared with those of a random sample of women from the same population. A history of cholecystectomy was somewhat more frequent among patients with colon cancer than among controls--we estimate the colon cancer risk in women without a gallbladder to be 1.4 times that of other women--but the 05% confidence limits of the relative risk included 1.0 (0.8--2.5). There was no association between cholecystectomy and rectal cancer and, among the subsites of colon cancer, the magnitude of the excess risk failed to show any consistent right--left gradient. Nonepidemiologic data suggest that cholecystectomy could increase the risk of colon cancer. However, if such an association truly exists it is not a strong one, and studies larger than those conducted to date are needed to detect this association reliably.

Correlates of homosexual behavior and the incidence of anal cancer

To determine whether characteristics that are correlated with male homosexual behavior are associated with the incidence of cancer, the names of persons with a diagnosis of cancer in western Washington during 1974 to 1979 were linked to those in the state syphlis registry. Eight of 47 men with anal cancer were found to have had a reactive FTA test result; the expected number, based on the proportion of reactive cases among men with other sites of cancer, was only 0.40. Among men with anal cancer identified through ten population-based cancer-reporting systems in the United States, 24.4% had never been married, compared with 7.8% of men with colon and rectal cancer. Neither of these relationships was observed for women with anal cancer. Because in men, but not in women, having had syphilis and being single are associated with the practice of anal intercourse, our data suggest that anal intercourse may be a risk factor for anal cancer.

Incidence of cancer of the large bowel in women in relation to reproductive and hormonal factors

Female resident of King and Pierce Counties (Washington) in whom carcinoma of the colon or rectum was diagnosed during a 15-month period in 1976-77 were interviewed regarding their menstrual and reproductive histories. A random sample of women from the same population was interviewed for comparison. On the average, women with colon cancer had given birth to fewer children than had controls; compared to the incidence of colon cancer in nulliparous women, the incidence in women with 1 or 2 children was reduced by 30%, whereas the incidence in women with 3 or more children was reduced by 50% (P=0.004). No association was present between parity and rectal cancer. Neither contraceptive nor noncontraceptive estrogen use was related to the incidence of colon cancer. Use of oral contraceptives was more common among women with rectal cancer than among controls, but this result could well have arisen by chance (P=0.09). The data were not adequate to determine whether it was the inability to conceive and deliver a child that was related to colon cancer or the failure to undergo the physiologic changes that accompany pregnancy. Nonetheless, the association of low parity with the incidence of colon cancer has now observed several times, in each instance to a moderately strong degree. This observation suggests that events of reproductive life have a bearing on a woman's subsequent risk of developing colon cancer.