Correlates of postmenopausal female hormone use among black women in the United States

OBJECTIVE

To assess correlates of the use of postmenopausal female hormone supplements among black women.

METHODS

We assessed information obtained from 64,564 U.S. black women 21-69 years of age who enrolled in the Black Women's Health Study in 1995 by completing postal questionnaires. Included in the present analyses were 13,352 women 40-69 years of age who had ceased menstruating. Most resided in ten states, with 66% from California, New York, Illinois, Michigan, Georgia, and New Jersey; 41.0% had completed college.

RESULTS

Among the 13,352 women 40 years of age or older who had ceased menstruating, 49.2% reported ever use of female hormone supplements and 33.3% were using them currently. Unopposed oral estrogens accounted for 63.4% of the medications being used currently. The use of supplements was highest in the western U.S. and lowest in the Northeast. The strongest correlate of use was menopause due to bilateral oophorectomy. Use peaked at 50-54 years of age and then declined, and also was associated positively with lower body mass index, greater years of education, participation in vigorous exercise, and past oral contraceptive use. Use was associated inversely with having a positive history of diabetes, heart attack, or breast cancer. Some of the drug use reported was at variance with suggested guidelines: unopposed estrogen was taken by some women who had a uterus, and estrogen together with a progestin was taken by some women who had had a hysterectomy.

CONCLUSION

These data indicate that patterns of use of postmenopausal female hormone supplements among black women who participated in the present study are similar to those documented in white women. Women with risk factors for coronary artery disease were not more likely to use supplements than women at lower risk, a pattern that is not in accordance with suggestions that the greatest benefit of supplements may accrue to high-risk women. Because users differ from nonusers in important characteristics that may affect the incidence of coronary heart disease, breast cancer, and other illnesses, observational studies of the health effects of these medications must control carefully for correlates of use.

Transitional cell cancer of the urinary tract and renal cell cancer in relation to acetaminophen use (United States)

Experimental and epidemiologic evidence have suggested that phenacetin use increases the risk of transitional cell cancers of the urinary tract. The drug is no longer marketed but a commonly used metabolite, acetaminophen, has been linked recently to an increased risk of renal cancer. We assessed the relation of acetaminophen use to the risk of transitional cell cancer of the urinary tract and of renal cell cancer with data from a hospital-based study of cancers and medication use conducted from 1976-96 in the eastern United States. We compared 498 cases of transitional cell cancer and 383 cases of renal cell cancer with 8,149 noncancer controls and 6,499 cancer controls and controlled confounding factors with logistic regression. For transitional cell cancer, the relative risk (RR) estimate for regular acetaminophen use that had begun at least a year before admission was 1.1 (95 percent confidence interval [CI] = 0.6-1.9) based on noncancer controls, and 0.9 (CI = 0.5-1.6) based on cancer controls. RR estimates for use that lasted at least five years, and for nonregular use, were also close to 1.0. For renal cell cancer, the corresponding estimates were again close to 1.0. Our results suggest that acetaminophen, as used in present study population, does not influence the risk of transitional cell cancer of the urinary tract or of renal cell cancer.

Induced and spontaneous abortion in relation to risk of breast cancer (United States)

The relation of induced and spontaneous abortion to the risk of breast cancer is evaluated in a hospital-based case-control interview study conducted in three cities in the United States from 1985 through 1995. Cases were 1,803 women aged 25 to 64 years with newly diagnosed invasive breast cancer; controls were 4,182 women of the same ages admitted for conditions unrelated to reproductive factors. Other breast cancer risk-factors were controlled through multiple logistic regression. The reference for all analyses was women who had never had an abortion, either induced or spontaneous. Among parous women, the relative risk (RR) estimate was 1.1 (95 percent confidence interval [CI] = 0.9-1.5) for induced abortion overall, 1.0 (CI = 0.7-1.4) for abortion before the first birth, and 1.3 (CI = 1.0-1.8) for abortion after at least one birth. Among nulliparous women, the relative risk estimate for induced abortion was 1.3 (CI = 0.9-1.9). There was no trend of increased risk with number of abortions, nor was there consistent evidence of an increased risk in any particular subgroup. Spontaneous abortion was not associated with increased risk of breast cancer, either among nulliparous women or among parous women. These findings provide little support for the hypothesis that induced abortion increases breast cancer risk overall or in particular subgroups.

13 pairs of ribs--a predictor of long gap atresia in tracheoesophageal fistula

Results of treatment of tracheoesophageal fistula (TEF) have improved over the years. However, long gap atresias continue to be a problem and require modification in the conventional operation. Preoperative diagnosis of a long gap atresia in a case of TEF is difficult, and often the defect is noted only at thoracotomy, thus necessitating multiple intraoperative changes in the position of the neonate. In the past 5 years the authors have treated 61 cases of TEF. Of these, 12 had a long gap atresia. Nine of these 12 patients had 13 pairs of ribs. None of the patients with a short gap atresia had 13 pairs of ribs. Hence, the presence of 13 pairs of ribs is a good indicator of long gap atresia. In a child who has TEF with 13 pairs of ribs, suitable modifications in operative procedure can be planned. The report also discusses the possible embryological basis of this association.

The A10 cell line: a model for neonatal, neointimal, or differentiated vascular smooth muscle cells?

OBJECTIVES

The A10 cell line was derived from the thoracic aorta of embryonic rat and is a commonly used model of vascular smooth muscle cells (VSMC). Despite its wide use this cell line has not been well characterized. This is especially important in light of recent evidence of phenotypically distinct cell populations isolated from rat vascular tissue. Therefore, the present study was undertaken to confirm the VSMC nature of A10 cells and to investigate whether these cells particularly resemble adult, neonatal, or neointimal rat VSMC.

METHODS

A variety of defining characteristics were used that included immunofluorescent analysis for smooth muscle alpha-actin, smooth and non-muscle myosin heavy chains, desmin and vimentin; Western analysis for smooth muscle and non-muscle myosin heavy chains; mRNA analysis for smooth muscle myosin heavy chain, calponin, SM22 alpha, tropoelastin and PDGF-B peptide; and functional assays of cell migration, proliferation and agonist induced intracellular Ca transients.

RESULTS

A10 cells expressed smooth muscle alpha-actin, SM22 alpha, smooth muscle calponin and vimentin, characteristic of in vivo rat VSMCs; however they also resembled de-differentiated smooth muscle cells in that they expressed non-muscle myosin rather than smooth muscle myosin heavy chain. A10 cells resembled cultured rat neonatal smooth muscle cells ("pup cells") in that they had an epithelioid shape and lacked functional PDGF-alpha receptors: however they did not express PDGF-B mRNA or proliferate in low serum containing medium as do neonatal cells. A10 cells had several characteristics in common with neointimal cells including the expression of alpha-actin, vimentin, and non-muscle myosin and the lack of expression of PDGF-B mRNA as well as the ability to migrate in response to PDGF-BB.

CONCLUSION

In conclusion, A10 cells are nondifferentiated VSMC that differ from neonatal but bear significant resemblance to neointimal cells.

Minimum inhibitory concentration (MIC) of some antibiotics against Vibrio cholerae O139 isolates from Pondicherry

The antibiotic susceptibility pattern of Vibrio cholerae O139, Bengal, an emerging intestinal pathogen has been determined by the Kirby Bauer technique and the MIC values of some antibiotics against these strains by agar dilution technique. All the strains were susceptible to tetracycline, norfloxacin, ciprofloxacin and a majority was susceptible to gentamicin (95.7%) and nalidixic acid (82.9%). Only 51% were susceptible to cefotaxime and most strains were resistant to furazolidone (95.7%), ampicillin (87.3%) and co-trimoxazole (91.5%). The study shows the importance of judicious use of antibiotics in cholera cases and the need for monitoring the susceptibility status of these strains particularly because of their ability to cause extra-intestinal infections like septicaemia.

gamma-Aminobutyric acid contributes to modulation of cardiorespiratory control after chronic ventilatory loading

Diseases imposing chronic ventilatory loads may depress ventilation and cause chronic hypercapnia. This may be a result of mechanical loading imposed on pre-existing decreased respiratory drive or functional alteration of neural circuits involved in ventilatory control. To evaluate these possibilities, chronic resistive airway loading was imposed in rats via a circumferential tracheal band which tripled tracheal resistance (obstructed group). Sham surgery was performed in controls. After 8 weeks, animals were anesthetized (urethane) and tracheostomy performed relieving increased tracheal resistance. The ventral medullary surface (VMS) was exposed and the intermediate area (IA) identified. The integrated diaphragm EMG (EMGDI) was recorded. The obstructed group was hypercapnic while controls were eucapnic (PCO2, 45.1 +/- 7.9 vs. 37.6 +/- 3.4 Torr; P < 0.001). Respiratory rate (RR) remained lower in obstructed than in control animals despite relief of the resistive load by tracheostomy (58.5 +/- 5.1 vs. 75.4 +/- 5.4 bpm; P < 0.05). Application of 1 mM bicuculline soaked pledgets (BIC) to the IA of the VMS significantly increased EMGDI in obstructed but not in control animals (27.5 +/- 5.5 vs. 5.2 +/- 4.4%; P < 0.006). RR was unaffected. Mean arterial pressure increased with BIC in obstructed but not control animals (23.0 +/- 6.5 vs. 4.5 +/- 3.5%; P < 0.02). These data suggest that alteration of cardiorespiratory control occurs during chronic resistive hypercapnic loading and that GABAergic neurons in the VMS participate in this adaptive response.

Effect of chronic resistive loading on hypoxic ventilatory responsiveness

Depression of ventilation mediated by endogenous opioids has been observed acutely after resistive airway loading. We evaluated the effects of chronically increased airway resistance on hypoxic ventilatory responsiveness shortly after load imposition and 6 wk later. A circumferential tracheal band was placed in 200-g rats, tripling tracheal resistance. Sham surgery was performed in controls. Ventilation and the ventilatory response to hypoxia were measured by using barometric plethysmography at 2 days and 6 wk postsurgery in unanesthetized rats during exposure to room air and to 12% O2-5% CO2-balance N2. Trials were performed with and without naloxone (1 mg/kg i.p.). Room air arterial blood gases demonstrated hypercapnia with normoxia in obstructed rats at 2 days and 6 wk postsurgery. During hypoxia, a 30-Torr fall in PO2 occurred with no change in PCO2. Hypoxic ventilatory responsiveness was suppressed in obstructed rats at 2 days postloading. Naloxone partially reversed this suppression. However, hypoxic responsiveness at 6 wk was not different from control levels. Naloxone had a small effect on ventilatory pattern at this time with no overall effect on hypoxic responsiveness. This was in contrast to previously demonstrated long-term suppression of CO2 sensitivity in this model, which was partially reversible by naloxone only during the immediate period after load imposition. Endogenous opioids apparently modulate ventilatory control acutely after load imposition. Their effect wanes with time despite persistence of depressed CO2 sensitivity.

Clinical and laboratory profile of sixty patients with AIDS: a South Indian study

Sixty patients who fulfilled the WHO case definition of acquired immunodeficiency syndrome (AIDS) were admitted and treated between January 1993 and June 1995 in JIPMER Hospital, Pondicherry, South India. Their mean age was 30.3 +/- 6.4 years. Male: female ratio was 5 : 1. The heterosexual route was the major mode of transmission (96.7%). Fever was the commonest presentation (98.3%), followed by weight loss (85%) and cough (36.7%). The commonest opportunistic infection seen was tuberculosis (pulmonary, extrapulmonary - single or in combination) followed by esophageal candidiasis. Cryptococcal meningitis, intestinal crytosporidiosis, CNS toxoplasmosis, Pneumocystis pneumonia and group B Salmonella septicemia were the other infections encountered. Ten out of the 38 patients with tuberculosis were followed up on antituberculous treatment for 6 months. Seven out of 18 patients with esophageal candidiasis were treated with ketoconazole.

Histologic trends in thyroid cancer 1969-1993: a clinico-pathologic analysis of the relative proportion of anaplastic carcinoma of the thyroid

BACKGROUND

It was observed that new presentations of anaplastic carcinoma of the thyroid had become infrequent in the last two decades.

METHODS

All cases of thyroid cancer seen at our centre between 1969-1993 (n = 2921) were classified as papillary 49%, follicular 34%, medullary 7.5%, anaplastic 4.7%, and other 4.8%. The total number of thyroid cancers show a 3.5-fold rise.

RESULTS

The differentiated thyroid cancers show a significant rising trend as against the relative proportion of anaplastic carcinoma, which shows a significant decline (P = 0.002). Clinicopathologic data on 124 patients of anaplastic carcinoma revealed 50% patients had either long-standing goitres, previous thyroid abnormalities, or associated differentiated thyroid carcinoma on histology.

CONCLUSIONS

The decline in the relative proportion of anaplastic carcinoma may in part be explained by the clinicopathologic findings or it may be attributed to histological reclassification.

Influence of parental literacy and socio-economic status on infant mortality

The influence of parental literacy and socio-economic status (SES) on infant mortality rate (IMR) was studied. This report is only a part of much larger community-based prospective study conducted to determine the factors influencing infant mortality in Dakshina Kannada district of Karnataka, by the Department of Community Medicine, Kasturba Medical College, Manipal, with the financial assistance form IDRC, Canada. A total of 12,857 livebirths during the period of October 1, 1991, to September 30, 1992, where registered and followed up for one year. There were 391 infant deaths which gives an IMR of 30.4 per 1,000 livebirths. Univariate analysis and subsequent stepwise multiple logistic regression analysis revealed that, literacy and SES have a very significant role in reducing IMR.

Cytogenetic studies on a patient with prepubertal breast cancer: a case report

Cytogenetic studies were carried in a 10 year old girl with prepubertal breast cancer for assessing inherited genetic susceptibility to chromosome breakage. The girl presented with a tumour in the left breast. Histologically it was diagnosed as secretory carcinoma (SC). Chromosome anomalies observed in phytohemagglutinin (PHA-P) stimulated lymphocytes were del(2)(q33), del(3)(p24), del(7)(q22) and dup(12)(p11p12). The regions involved have been reported in breast tumors. These loci, detected in peripheral blood lymphocytes (PBL), could be the sites susceptible to breakage, its subsequent effect being manifested in the target (breast) tissue.

Improved survival in cervical cancer cases in a rural Indian population

In the first Rural Cancer Registry in India, 194 cervical cancer cases were registered during 1988-91. The 3 year survival was significantly higher in cases registered in 1990-91 (40.0%), than in those registered in the earlier years (26.6%). This improvement was due to the cancer education activities undertaken by the Registry.

Prognostic factors in follicular carcinoma of the thyroid: a study of 198 cases

BACKGROUND

Prognostic parameters for papillary carcinoma of the thyroid have been defined by several groups. However, no such study has been reported for follicular carcinoma.

METHODS

We undertook a retrospective study of well-differentiated carcinoma of the thyroid operated at the Tata Memorial Hospital during the period 1970-1985. In our series, follicular carcinoma formed 48% of the well-differentiated carcinomas of the thyroid. The variables age, sex, size, extrathyroidal spread, distant metastases, and lymph node metastases were evaluated. The survival was plotted according to the Kaplan-Meier method, and graphs compared by log-rank test. Univariate and multivariate analyses were performed.

RESULTS

Based on our experience we stratified the cases into low-risk and high-risk groups. The low-risk group included: age below 40 years, tumor size less than 5 cm. and no extrathyroidal extension or metastases. This low risk group had 100% survival at 15 years, compared with 40% survival for the high-risk group (P <.001). Seventy-three percent (73%) of our cases were in the high-risk group.

CONCLUSIONS

Based on our findings that the majority of our patients were in the high-risk group, we advocate a total or near-total thyroidectomy in treatment of follicular carcinoma of the thyroid. There is a need to arrive at a universally acceptable classification of risk groups in follicular carcinoma of the thyroid gland.

Case-control study of oral contraceptive use and risk of breast cancer

The relation of oral contraceptive use to the risk of breast cancer in white women aged 25-59 years was assessed with data collected during 1977-1992 in a case-control surveillance system in hospitals in Boston, New York, and Philadelphia. A total of 3,540 cases with breast cancer were compared with 4,488 controls with nonmalignant nongynecologic conditions unrelated to oral contraceptive use. Relative risk estimates were obtained by unconditional logistic regression with control for major risk factors. For at least 1 year of use relative to less than 1 year, the multivariate relative risk estimate was 1.7 (95% confidence interval (CI) 1.3-2.3) in women aged 25-34 years, 0.9 (95% CI 0.7-1.0) in women aged 35-44 years, and 1.2 (95% CI 1.0-1.4) in women aged 45-59 years (p < 0.01 for the difference across age). Among women aged 25-34 years, the relative risk estimates were greatest for use of long duration, but the trend was not statistically significant (p = 0.17); in addition, the duration of use was correlated with the recency of use, and it was not possible to distinguish their effects. Among women aged 35-44 years, the relative risk estimate decreased with increasing duration of use (p = 0.01). Among women aged 45-59 years, some relative risk estimates were increased, but there was no consistent pattern. The results add to the evidence of an association between oral contraceptive use and an increased risk of breast cancer at young ages.

Infant feeding--knowledge and attitudes in a rural area of Karnataka

A study of the knowledge and attitude towards infant feeding was conducted in South India on a group of 300 mothers whose babies' ages from 3 days to 17 months. Most of the mothers opined that breast-feeding had to be initiated within 24 hours of birth. However, only 32% felt that breast milk should be the first feed, whereas 68% considered prelacteal feeds a necessity. 71% of the mothers considered 3 to 5 months to be the optimum duration of exclusive breast-feeding. 90% felt that cow's milk was an ideal supplement. 78.3% subscribed to the view that breast-feeding should continue beyond one year. A sizeable proportion expressed the need to discontinue breastfeeds during babies' or maternal illness, particularly diarrhoea. Our results will form the babies of the content and the target groups in our future health education programme.

Improved stage at diagnosis of cervical cancer with increased cancer awareness in a rural Indian population

As part of its strategy to identify cancer cases in a rural population, the cancer registry of Barshi, India, has developed a methodology which includes education of the population about likely symptoms of cancer, and motivation of symptomatic individuals to undergo medical investigation. Patients with cervical cancer from the registry area who attended Barshi Cancer Hospital (84% of the total) showed a significant improvement in stage at diagnosis between 1988-1989 (38% in stages I and II) and 1990-1992 (51% in stages I and II). No change was observed in those attending the same hospital from a control area (38% vs. 34%). Among a random sample of the population of the registry area, 76% of women were aware of the symptoms of cervical cancer, compared with 25% of the population of control areas. It is suggested that action to raise awareness of symptoms of cancer, and to encourage medical consultation, should form an important initial component of cervical-cancer control programmes.

Stool culture as a diagnostic aid in the detection of Entamoeba histolytica in the faecal specimens

"The use of stool culture in Boeck & Drbohlav's biphasic amoebic medium as a routine diagnostic aid in the detection of Entamoeba histolytica in the faeces, is evaluated in the present study. A total of 3803 faecal specimens were examined for the presence of E.histolytica by direct smear, formalin ether concentration and culture during a study period of 1982-1990. A total of 259 stool specimens were positive for the parasite by any or all of these methods 42 (16.21%) stool specimen not cultured in Boeck & drbohlav's medium were possible by direct smear and concentration methods. 99 (38.22%) stool specimens were positive by all of these methods (direct smear, concentration and culture). The culture detected E. histolytica in additional 62 (23.93%) stool specimens which were negative by both the direct smear and concentration methods. Results of this study recommends the use of stool culture as a routine diagnostic aid in the laboratory, for the detection E. histolytica in the faeces".

Laryngectomy: a quality of life assessment

Cosmetic disfigurement and loss of voice following a total laryngectomy can cause major psychosocial problems. Fifty patients who had undergone a total laryngectomy and completed more than six months following surgery, were randomly selected during a routine follow-up, and asked to answer a questionnaire, to asses their degree of disability and extent of rehabilitation. The questionnaire have five main components viz. general information, functional evaluation, vocal rehabilitation, social assessment and economic sequelae. Results revealed that these patients suffered from a significant decrease in social acceptance (70%), social activity (82%), sexual activity (62%), ability to communicate vocally (58%), and severe financial repercussions (78%). A large number of patients (40%) were dissatisfied with the present level of rehabilitation offered. Inspite of these problems the majority (80%) were willing to accept a total laryngectomy as treatment of their cancer. This emphasizes the need for greater interaction between the treating surgeon, speech therapist, occupational therapist, and psychotherapist to rehabilitate these patients adequately.

Effect of chronic resistive loading on ventilatory control in a rat model

Acute resistive loading of the airway has been shown to activate the endogenous opioid system, with subsequent depression of ventilation. The present investigation was designed to assess the effect of chronic airway loading on ventilation and CO2 sensitivity, and to determine whether the endogenous opioid system contributes to long-term modulation of ventilatory control in this setting. A flow-resistive ventilatory load was imposed in 2-mo-old rats by surgical implantation of a circumferential tracheal band that approximately tripled tracheal resistance. Respiration and CO2 sensitivity were serially and noninvasively assessed by barometric plethysmography over a period of 21 wk. Ventilatory output was assessed as minute inspiratory effort, which was defined as the product of plethysmograph signal amplitude, inspiratory time, and respiratory rate (RR). CO2 sensitivity was calculated as the percent change in minute inspiratory effort from room air to CO2 exposure. The effect of naloxone administration on these parameters was also determine. Arterial blood gases demonstrated hypercapnia with maintenance of normoxia in loaded rats; these findings persisted for the duration of the study. Two days after surgery, rats with tracheal obstruction demonstrated a lower RR than controls during room air breathing and during CO2 stimulation. CO2 sensitivity was significantly depressed in obstructed animals at this time. Escape from suppression of RR and CO2 sensitivity was evident by 14 to 21 d after obstruction; however, suppression of these parameters reappeared and was maintained from 56 to 147 d after obstruction. Naloxone augmented minute inspiratory effort during CO2 stimulation at 2 d after obstruction but not thereafter; naloxone had no effect in control rats. These data indicate that chronic airway loading suppresses RR and CO2 sensitivity in a triphasic manner. The early suppression is partially reversible by naloxone; late-appearing suppression is unaffected by naloxone and is presumably mediated by mechanisms that do not involve endogenous opioids.

Oral contraceptive use and breast cancer risk among African-American women

Recent epidemiologic studies, most of them in predominantly White populations, have suggested that long duration of oral contraceptive (OC) use may increase the risk of breast cancer at young ages. We assessed the relationship of OC use to the risk of breast cancer in African-American women aged 25 to 59 years, using interview data from a multipurpose hospital-based case-control study. Five hundred and twenty-four cases hospitalized for invasive breast cancer were compared with 1,021 controls with nonmalignant conditions unrelated to OC use. Relative risks (RR) and 95 percent confidence intervals (CI) were estimated relative to a reference category of use for less than 12 months; potential confounders were controlled by multiple logistic regression analysis. Among women under age 45, three or more years of OC use was associated with an increased risk of breast cancer: the RR estimate was 2.8 (CI = 1.5-5.0) for three to four years of use, and declined to 1.5 (CI = 08.3.0) for 10 or more years of use. Recency and timing of use did not explain the observed association. Among women aged 45 to 59, OC use was associated with little or no increase in risk: the RR estimate for three or more years of use was 1.3 (CI = 0.7-2.4). The findings add to the evidence from studies of White women and a recent study of Black women which have suggested an increased risk of breast cancer at young ages for moderate or long duration use of OCs.

Extent of lymph node dissection in T3/T4 cancer of the alveolo-buccal complex

BACKGROUND

Cancer of the alveolo-buccal complex even when locally advanced is amenable to curative resection. However, the extent of lymph node dissection remains controversial.

METHODS

A total of 181 patients with T3/T4 cancer of the alveolo-buccal complex who underwent a radical neck dissection (RND) were analyzed retrospectively to determine the incidence and pattern of lymph node involvement and to define the extent of neck dissection required in these cancers.

RESULTS

Lymph node involvement was as follows: level I (85%), II (51%), III (19%), IV (18%), V (5%). Levels I and II were most commonly involved (94%). Skip metastases occurred in 13%. Levels IV and V were involved in 2% and 20% when levels I, II, and III were uninvolved and involved, respectively.

CONCLUSION

A supraomohyoid neck dissection (SOHD) should be performed and subjected to a frozen section evaluation in every patient. If lymph nodes are negative, then SOHD is adequate. If levels I, II, or III are positive, then a RND should be performed.

Coffee consumption and myocardial infarction in women

Whether coffee consumption increases the risk of coronary heart disease has not yet been established. In a case-control study of nonfatal myocardial infarction among Massachusetts women aged 45-69 years in 1986-1990, 858 cases with first infarctions were compared with 858 community controls matched on age and town precinct. Detailed information on coffee drinking, cigarette smoking, and other factors was obtained by telephone interview. Relative risks (as estimated by odds ratios) and their 95% confidence intervals were computed from multiple logistic regression analyses that controlled for smoking and other risk factors. The risk of myocardial infarction increased with increasing number of cups per day among both drinkers of any type of coffee and drinkers of caffeine-containing coffee only: tests for trend, p = 0.002 and p = 0.0004, respectively. For consumption of caffeine-containing coffee alone, the relative risk estimates for 5-6 cups, 7-9 cups, and 10 or more cups per day relative to less than 1 cup per day were 1.4 (95% confidence interval (CI) 0.8-2.5), 2.1 (95% CI 0.9-4.9), and 2.5 (95% CI 1.0-6.5), respectively. No increase was observed for fewer than 5 cups per day. The positive association with heavy coffee drinking was present among nonsmokers as well as smokers. These findings and other recent studies suggest that heavy coffee consumption increases the risk of myocardial infarction.

Mechanisms of myocardial depression after bolus injection of sodium bicarbonate

PURPOSE

The classic model for the effects of NaHCO3 on myocardial function predicts transient myocardial depression after an intravenous bolus of sodium bicarbonate in association with myocardial acidosis.

METHODS

Five anesthetized, paralyzed, and ventilated dogs underwent midline sternotomy. Myocardial global function was assessed by cardiac output, left ventricular (LV) dp/dt, LV end-systolic, and LV end-diastolic pressures. Regional myocardial function assessed by measuring the LV regional end-systolic, LV end-diastolic lengths, and LAD coronary blood flow. Coronary sinus, intramyocardial and arterial pH were measured as was free serum Ca++. Animals were made acidemia by infusion of 0.3 N HCl and then given a bolus of sodium bicarbonate. This produced transient depression followed by recovery of myocardial function.

RESULTS

During the depression phase there was no significant decrease in interstitial pH or an increase in A-VCO2 difference as predicted by the current model. However, there was a significant decrease in the serum free Ca++ that coincided with myocardial depression.

CONCLUSION

We could not confirm the predictions of the classic model and hypothesize that myocardial depression may be caused by decreased availability of free Ca++ of decreased Ca++ flux rather than intracellular acidosis.