Trial of calcium to prevent preeclampsia

BACKGROUND

Previous trials have suggested that calcium supplementation during pregnancy may reduce the risk of preeclampsia. However, differences in study design and a low dietary calcium intake in the populations studied limit acceptance of the data.

METHODS

We randomly assigned 4589 healthy nulliparous women who were 13 to 21 weeks pregnant to receive daily treatment with either 2 g of elemental calcium or placebo for the remainder of their pregnancies. Surveillance for preeclampsia was conducted by personnel unaware of treatment-group assignments, using standardized measurements of blood pressure and urinary protein excretion at uniformly scheduled prenatal visits, protocols for monitoring these measurements during the hospitalization for delivery, and reviews of medical records of unscheduled outpatient visits and all hospitalizations.

RESULTS

Calcium supplementation did not significantly reduce the incidence or severity of preeclampsia or delay its onset. Preeclampsia occurred in 158 of the 2295 women in the calcium group (6.9 percent) and 168 of the 2294 women in the placebo group (7.3 percent) (relative risk, 0.94; 95 percent confidence interval, 0.76 to 1.16). There were no significant differences between the two groups in the prevalence of pregnancy-associated hypertension without preeclampsia (15.3 percent vs. 17.3 percent) or of all hypertensive disorders (22.2 percent vs. 24.6 percent). The mean systolic and diastolic blood pressures during pregnancy were similar in both groups. Calcium did not reduce the numbers of preterm deliveries, small-for-gestational-age births, or fetal and neonatal deaths; nor did it increase urolithiasis during pregnancy.

CONCLUSIONS

Calcium supplementation during pregnancy did not prevent preeclampsia, pregnancy-associated hypertension, or adverse perinatal outcomes in healthy nulliparous women.

Randomized clinical trials in periodontology: ethical considerations

Ethical justification for starting a clinical trial requires at the outset an accurate statement of "no difference" regarding the two or more agents to be compared. This may be expressed as "theoretical equipoise" (no data to support the superiority of one of the agents) or, preferably, as "clinical equipoise" (there are insufficient data to resolve controversy among experts as to which is superior). This presents a problem when a placebo control is proposed, particularly when the outcome measure entails irreversible loss of function; preliminary data often suggest the superiority of the "active agent." Informed consent should ordinarily include the fact that treatment assignments will be accomplished by a process of randomization and, in the case of double-blind designs, that neither the subject nor the investigator will know the subject's treatment assignment until the end of the trial. In general, clinical trials should be monitored by data and safety monitoring boards that have access to unblinded data; they should be guided by stopping rules that should be agreed upon by all concerned before the trial is begun. Women and minorities must be included unless there is strong justification for their exclusion. Care must be taken to balance the competing objectives of validity (the results will be correct), generalizability (the results will be broadly applicable), and efficiency (the study will not be unduly expensive).

Trial of Calcium for Preeclampsia Prevention (CPEP): rationale, design, and methods

The results of ten clinical trials suggest that supplemental calcium may prevent preeclampsia. However, methodologic problems and differences in study design limit the acceptance of the results and their relevance to other patient populations. Many of the trials were conducted in countries where, unlike the United States, the usual daily diet contained little calcium. Moreover, none of the trials has reported the outcome of systematic surveillance for urolithiasis, a potential complication of calcium supplementation. In response to the need for a thorough evaluation of the effects of calcium supplementation for the prevention of preeclampsia in the United States, the trial of Calcium for Preeclampsia Prevention (CPEP) was undertaken at five university medical centers. Healthy nulliparous patients were randomly assigned to receive either 2 g supplemental calcium daily (n = 2295) or placebo (n = 2294) in a double-blind study. Study tablets were administered beginning from 13 to 21 completed weeks of gestation and continued until the termination of pregnancy. CPEP employed detailed diagnostic criteria, standardized techniques of measurement, and systematic surveillance for the major study endpoints and for urolithiasis. The nutrient intake of each patient was assessed at randomization and at 32-33 weeks gestation. This report describes the study rationale, design, and methods.

Patellar tendon rupture. The importance of timely recognition and repair

Patellar tendon rupture is not uncommon in active adults, although it occurs less often than rupture of the ligaments. The diagnosis is easily missed on initial examination. Delay of surgical treatment leads to a complicated repair and a less functional outcome. The key physical finding is inability to actively extend the affected leg. Patients may also have severe, rapid swelling and depression in the infrapatellar region. The mechanism of injury usually involves forced hyperflexion or rapid extension from a weight-bearing position. Radiographic findings include patella alta and possible subluxation. This case report described an infrapatellar tendon rupture in a patient with no underlying systemic disease or history of repetitive trauma.

Myosin light chain phosphorylation affects the structure of rabbit skeletal muscle thick filaments

To identify the structural basis for the observed physiological effects of myosin regulatory light chain phosphorylation in skinned rabbit skeletal muscle fibers (potentiation of force development at low calcium), thick filaments separated from the muscle in the relaxed state, with unphoshorylated light chains, were incubated with specific, intact, myosin light chain kinase at moderate (pCa 5.0) and low (pCa 5.8) calcium and with calcium-independent enzyme in the absence of calcium, then examined as negatively stained preparations, by electron microscopy and optical diffraction. All such experimental filaments became disordered (lost the near-helical array of surface myosin heads typical of the relaxed state). Filaments incubated in control media, including intact enzyme in the absence of calcium, moderate calcium (pCa 5.0) without enzyme, and bovine serum albumin substituting for calcium-independent myosin light chain kinase, all retained their relaxed structure. Finally, filaments disordered by phosphorylation regained their relaxed structure after incubation with a protein phosphatase catalytic subunit. We suggest that the observed disorder is due to phosphorylation-induced increased mobility and/or changed conformation of myosin heads, which places an increased population of them close to thin filaments, thereby potentiating actin-myosin interaction at low calcium levels.

Analysis of federally imposed penalties for violations of the Consolidated Omnibus Reconciliation Act

STUDY OBJECTIVE

To identify the incidence of federally imposed penalties for violations of the Consolidated Omnibus Reconciliation Act (COBRA).

METHODS

Under the Freedom of Information Act, we retrieved a copy of any document related to fines imposed on, settlements made by, or litigation against physicians or hospitals as a result of COBRA violations from the Office of the Inspector General. Under a separate inquiry, also under the Freedom of Information Act, we requested and received from the central office of the Health Care Financing Administration the National Composite Log showing the status of all complaint investigations pursuant to COBRA since the inception of the law.

RESULTS

One thousand seven hundred fifty-seven complaint investigations were authorized. Of the 1,729 investigations completed, 412 (24%) were found to be out of compliance with federal regulations. Of these, 27 cases resulted in fines imposed on hospitals. These fines ranged from $1,500 to $150,000 with a mean of $33,917, a median of $25,000, and standard deviation of $35,899. The six fines that were imposed against physicians ranged in value from $2,500 to $20,000 with a mean of $8,500, a median of $7,500, and an SD of $8,612. Seven hospitals but no physicians were terminated from the Medicare program for COBRA violations.

CONCLUSION

The incidence of federally imposed penalties for COBRA violations is low given the multitude of patient transfers that have occurred since the enactment of COBRA. The growing concern regarding this issue may be related to current litigation efforts to broaden the scope and applications of these laws.

Bilateral vocal cord paralysis following blunt trauma to the neck

Blunt trauma to the anterior neck has been known to cause upper-airway obstruction requiring emergency tracheostomy. We report the case of a 26-year-old man who sustained blunt trauma to the anterior neck in whom upper-airway obstruction developed. Although computed tomography of the neck revealed a thyroid cartilage fracture and a retropharyngeal hematoma, fiberoptic examination of the larynx identified vocal cord paralysis as the primary cause of his upper-airway obstruction. Emergency tracheostomy was performed, and the patient recovered uneventfully. A Medline search of the literature for the past 3 years failed to identify any individual case reports of bilateral vocal cord paralysis secondary to blunt anterior neck trauma.

Mortality of iron foundry workers. III. Lung cancer case-control study

A nested case-control study was undertaken to identify the determinants of lung cancer mortality in a cohort of 8147 foundry men among whom an excess of lung cancer deaths was previously observed. The present study consisted of all lung cancer deaths (N = 220) that occurred within this cohort between 1950 and 1989. both living and dead controls, matched on race and attained age, were selected in the ratio of 10:1 (N = 2200) by means of the incidence density sampling procedure. All cases and two controls per case, randomly selected from each case's 10 controls, were included in a smoking history survey. Basic smoking history information was obtained for about 71% of these study subjects. For the purpose of this study, formaldehyde exposure levels were categorized as high, medium, low, and none. Airborne silica exposure was categorized only as high, medium, and low levels, because all foundry workers were known to be exposed to silica. Conditional logistic regression analyses indicated that cigarette smoking was a strong predictor of lung cancer mortality in this cohort. Neither exposure to formaldehyde nor silica exposure level, nor employment in any of the six major work areas within the foundry, showed an association with lung cancer.

The impact of HIV infection on society's perception of clinical trials

All international codes of research ethics and virtually all national legislation and regulation in the field of research involving human subjects project an attitude of protectionism. Written with the aim of avoiding a repetition of atrocities like those committed by the Nazi physician-researchers, calamities like the thalidomide experience, or ethical violations like those of the Tuskegee syphilis study, their dominant concerns are the protection of individuals from injury and from exploitation. In recent years, however, society's perception of clinical research has shifted dramatically. Now, largely as a consequence of the efforts of the AIDS activists, clinical research is widely perceived as benign and beneficial. Although this shift in attitude has resulted in some important improvements in research policies and practices, this new perception is just as wrong-headed as was the earlier excessive protectionism. It is necessary to maintain a balanced perspective; our policies should encourage the conduct of ethical research while maintaining the vigilance necessary to safeguard the rights and welfare of the subjects.

Ethics of clinical trials. Do they help the patient?

Ethical justification of a randomized clinical trial requires at the onset that the investigators be able to state an honest null hypothesis regarding the therapies to be compared. For example, in a randomized clinical trial with only two arms (A and B), it is necessary to state that there is no scientifically validated reason to predict that therapy A will prove to be either superior or inferior to therapy B. Moreover, there must be no therapy C known to be superior to A and B unless there is a cogent reason to reject therapy C; the population of research subjects will consist either of those in whom therapy C has been tried without success or individuals who are aware of therapy C and have rejected it for various reasons. Thus, theoretically, the patients enrolled in a randomized clinical trial are assured that they will receive one of the two best known therapies for their condition. At first glance, one might conclude that randomized clinical trials do, in general, help the patient. There are some features of at least some clinical trials, however, that may be detrimental to the interests of some patients. It commonly is said, for example, that patients in randomized clinical trials are deprived of the "good of personal care." The physician-investigator may be constrained by rigid protocol requirements from being responsive to the particular needs and desires of the patient. Additionally, the process of obtaining informed consent to randomized clinical trials may be preemptive: patients who might have chosen palliative care rather than chemotherapy may not be afforded adequate opportunity to make such a choice. Any randomized clinical trial should maximize the likelihood of helping the patient.