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Biomedical subjects

M B Bracken

Publications and source records attributed to M B Bracken.

At least 19 recordsLinked to original sources
PubMed1992

A model for estimating level and net severity of spinal cord injuries.

Objective and detailed neurological assessments are essential in studies of the treatment and the epidemiology of acute spinal cord injuries. In practice, investigators use the expanded score, found by taking the total of the individual determinations, but this summary obscures important detail as to the level and the overall severity of injury. To address this issue, we present a method for estimating level and net severity of injury that makes use of isotonic regression and the Spearman-Kärber estimator. We describe the method for both sensory and motor assessments of neurologic function. In the special case where one gives an identical weight to the response at each level, these estimators algebraically partition the expanded score into separate contributions due to level and net severity. We provide a numerical example using data from the first National Acute Spinal Cord Injury Study, and we present a summary of the distribution of these parameters for this population.

Evaluation Studies as Topic↗
PubMed1992

The relationship between acute inflammatory lesions of the preterm placenta and amniotic fluid microbiology.

OBJECTIVE: Our objective was to determine the relationship between microbial invasion of the amniotic cavity and the presence and severity of acute inflammatory lesions in the placenta. STUDY DESIGN: Placental histologic and amniotic fluid microbiologic studies were performed in 92 consecutive patients who were admitted with preterm labor and intact membranes and delivered within 48 hours after amniocentesis. RESULTS: The prevalence of a positive amniotic fluid culture was 38% (35 of 92). There was a strong association between the presence and severity of inflammation in the amnion, chorion-decidua, umbilical cord, and chorionic plate and the results of the amniotic fluid culture (p less than 0.0001 for each tissue section). Three patterns of inflammation of the chorion-decidua were identified: marginating, nonmarginating, and a mixed pattern. The marginating and the mixed patterns of inflammation were strongly associated with the presence of a positive amniotic fluid culture. Acute inflammation of the chorionic plate was the most sensitive indicator of a microbial invasion of the amniotic cavity (sensitivity 96.6%), and funisitis and umbilical vasculitis had the highest specificity (85.7%). CONCLUSION: The presence of acute inflammatory lesions of the chorioamniotic membranes can serve as a marker of microbial invasion of the amniotic cavity.

Amnion↗
PubMed1992

Methylprednisolone or naloxone treatment after acute spinal cord injury: 1-year follow-up data. Results of the second National Acute Spinal Cord Injury Study.

The 1-year follow-up data of a multicenter randomized controlled trial of methylprednisolone (30 mg/kg bolus and 5.4 mg/kg/hr for 23 hours) or naloxone (5.4 mg/kg bolus and 4.0 mg/kg/hr for 23 hours) treatment for acute spinal cord injury are reported and compared with placebo results. In patients treated with methylprednisolone within 8 hours of injury, increased recovery of neurological function was seen at 6 weeks and at 6 months and continued to be observed 1 year after injury. For motor function, this difference was statistically significant (p = 0.030), and was found in patients with total sensory and motor loss in the emergency room (p = 0.019) and in those with some preservation of motor and sensory function (p = 0.024). Naloxone-treated patients did not show significantly greater recovery. Patients treated after 8 hours of injury recovered less motor function if receiving methylprednisolone (p = 0.08) or naloxone (p = 0.10) as compared with those given placebo. Complication and mortality rates were similar in either group of treated patients as compared with the placebo group. The authors conclude that treatment with the study dose of methylprednisolone is indicated for acute spinal cord trauma, but only if it can be started within 8 hours of injury.

Acute Disease↗
PubMed1992

The Second National Acute Spinal Cord Injury Study.

In 1990, the Second National Acute Spinal Cord Injury Study reported that high-dosage methylprednisolone improves neurologic recovery in spinal-injured humans. The study showed that patients who received the drug within 8 hr after injury improved, whereas those who received the drug later did not. The drug significantly increased recovery even in severely injured patients who were admitted with no motor or sensory function below the lesion, contradicting a long-held dogma that such patients would not recover. Some researchers, however, have questioned the stratification of the patient population, the use of summed neurologic change scores, and the absence of functional assessments. The stratification by injury severity and treatment time was planned a priori and based on objective criteria. Detailed analyses revealed no differences between groups attributable to stratification or randomization. While multivariate analyses of the summed neurologic scores were used, the conclusions were corroborated by other analytical approaches that did not rely on summed scores. For example, treatment with methylprednisolone more than doubled the probability that patients would convert from quadriplegia or paraplegia to quadriparesis or paraparesis, analgesia to hypalgesia, and anesthesia to hypesthesia. The treatment also significantly improved neurologic scores in lumbosacral segments, indicating that beneficial effects were not limited to segments close to the lesion site. The treatment did not significantly affect mortality or morbidity. The study strongly suggests that methylprednisolone has significant beneficial effects in human spinal cord injury, that these effects occur only when the drug is given within 8 hr, and that it helps even in patients with severe spinal cord injuries. These conclusions have important implications for spinal cord injury care and research.

Drug Administration Schedule↗
PubMed1991

Medication in early pregnancy: prevalence of use and relationship to maternal characteristics.

Medication use was assessed in a population of 4186 women who were delivered of infants at Yale-New Haven Hospital, New Haven, Connecticut, between 1980 and 1982. The frequency of over-the-counter and prescription drug use, and the association of such use with maternal characteristics was studied. Of all women, 66% used at least one drug. The mean number of drugs used by all subjects was 1.3 and, among drug users, 2.9. Of all drugs used, 68% were over-the-counter and 32% were prescription preparations. Internal analgesics, autonomic drugs, antiinfective agents, and antacids were most frequently used. Women who used prescription drugs were also more likely to use over-the-counter medications. Maternal characteristics that were associated with an increase in both over-the-counter and prescription drug use were being white, smoking more than 20 cigarettes a day, using alcohol, using caffeine, and smoking marijuana. These findings suggest that women who engage in "risk-taking behavior" during pregnancy are also more likely to use medications while pregnant.

Adult↗
PubMed1991

Treatment of acute spinal cord injury with methylprednisolone: results of a multicenter, randomized clinical trial.

Although some evidence of neurological improvement with naloxone exists in this trial, the improvement was never significantly better than that seen for placebo. Methylprednisolone (MP) was effective in reducing some of the permanent paralysis after acute spinal cord injury at the doses studied, but only when treatment began within 8 h after injury. There is currently no support for the administration of higher or lower doses of the drug and an apparent contraindication to initiating administration of MP at any dose more than 8 h after injury.

Acute Disease↗
PubMed1990

A randomized, controlled trial of methylprednisolone or naloxone in the treatment of acute spinal-cord injury. Results of the Second National Acute Spinal Cord Injury Study.

Studies in animals indicate that methylprednisolone and naloxone are both potentially beneficial in acute spinal-cord injury, but whether any treatment is clinically effective remains uncertain. We evaluated the efficacy and safety of methylprednisolone and naloxone in a multicenter randomized, double-blind, placebo-controlled trial in patients with acute spinal-cord injury, 95 percent of whom were treated within 14 hours of injury. Methylprednisolone was given to 162 patients as a bolus of 30 mg per kilogram of body weight, followed by infusion at 5.4 mg per kilogram per hour for 23 hours. Naloxone was given to 154 patients as a bolus of 5.4 mg per kilogram, followed by infusion at 4.0 mg per kilogram per hour for 23 hours. Placebos were given to 171 patients by bolus and infusion. Motor and sensory functions were assessed by systematic neurological examination on admission and six weeks and six months after injury. After six months the patients who were treated with methylprednisolone within eight hours of their injury had significant improvement as compared with those given placebo in motor function (neurologic change scores of 16.0 and 11.2, respectively; P = 0.03) and sensation to pinprick (change scores of 11.4 and 6.6; P = 0.02) and touch (change scores, 8.9 and 4.3; P = 0.03). Benefit from methylprednisolone was seen in patients whose injuries were initially evaluated as neurologically complete, as well as in those believed to have incomplete lesions. The patients treated with naloxone, or with methylprednisolone more than eight hours after their injury, did not differ in their neurologic outcomes from those given placebo. Mortality and major morbidity were similar in all three groups. We conclude that in patients with acute spinal-cord injury, treatment with methylprednisolone in the dose used in this study improves neurologic recovery when the medication is given in the first eight hours. We also conclude that treatment with naloxone in the dose used in this study does not improve neurologic recovery after acute spinal-cord injury.

Acute Disease↗
PubMed1990

Association of cocaine use with sperm concentration, motility, and morphology.

Use of cocaine within 2 years of their first semen analysis has been found to be twice as common among men with sperm counts less than 20 X 10(6) mL (odds ratio [OR] = 2.1, 95% confidence interval [CI] 1.0, 4.6). Duration of cocaine use for five or more years was more common in men with low sperm motility (OR = 2.0, 95% CI 1.0, 4.1) and in those with low concentrations and a large proportion of abnormal forms. Other major risk factors for these three indicators of male subfertility also have been identified, but the cocaine risk factors remained after adjustment for them. This association, together with the high prevalence of cocaine use in the general male population, suggests cocaine may now be related to male subfertility and that history of use should be ascertained during diagnostic interviews.

Adult↗
PubMed1990

Effect of maternal work activity on preterm birth and low birth weight.

The association of the prolonged standing required by certain jobs with the rate of preterm births and low birth weight deliveries was examined in New Haven, Connecticut, between 1980 and 1982. In a sample of 1,206 women, the rate of preterm births (births occurring less than 37 weeks from the last menstrual period) was higher among women with jobs requiring prolonged standing (7.7%) compared with those with sedentary (4.2%) or active jobs (2.8%). The odds of preterm delivery in the standing group was 2.72 (95% confidence interval of 1.24-5.95). A significant association between standing on the job and preterm birth was demonstrated when adjustment was made for the following variables in a logistic regression model: parity, smoking, education, caffeine use, marijuana use, race, gestational age at interview, and marital status. The low birth weight (less than 2,500 g) rate was higher among those in the standing group (5.5%) compared with those in the sedentary (4.0%) and active groups (4.0%), but this association was not significant when confounding factors were controlled.

Adolescent↗
PubMed1990

Oral contraception and congenital malformations in offspring: a review and meta-analysis of the prospective studies.

The technique of meta-analysis was used to derive typical estimates of the risk of congenital malformations from oral contraceptive (OC) exposure in early pregnancy. Several definitions were used for non-exposure to reduce bias from this source. Congenital heart defects and limb reduction defects were analyzed separately. The typical relative risk from the 12 prospective studies analyzed was 0.99 (95% confidence interval 0.83, 1.19) for all malformations. The definition of non-exposure did not materially change this estimate. The typical risk for congenital heart defects was 1.06 (95% confidence interval 0.72, 1.56) and for limb reduction defects, 1.04 (95% confidence interval 0.30, 3.55). This lack of an association between OCs and birth defects in prospective studies agrees with the results of most of the better-designed case-control studies.

Abnormalities, Drug-Induced↗
PubMed1990

Conception delay after oral contraceptive use: the effect of estrogen dose.

A significant delay was observed in conception among 248 former oral contraceptive (OC) users compared with women discontinuing other methods of contraception (n = 1,365). The mean time to conception was 5.88 cycles (95% confidence interval [CI] 5.38, 6.38) for former OC users and 3.64 cycles (95% CI 3.49, 3.79) after other contraceptives. Women discontinuing OCs with higher doses of estrogen (greater than or equal to 50 micrograms) had greater conception delays than those on lower estrogen doses who, in turn, had longer delays than other method users. Oral contraceptive use was associated with significant reductions in conception for each of the first six cycles after discontinuation. This study provides further evidence for a direct effect of oral contraception on delayed conception, suggests that the delay lasts longer than previously thought, and finds that the probability of conception after OC discontinuation depends on the estrogen dose of the OC.

Adolescent↗