Biomedical subjects

D D McIntire

Publications and source records attributed to D D McIntire.

At least 55 records · Page 3Linked to original sources

PubMed1995

Allele-specific chromosome 3p deletions occur at an early stage in the pathogenesis of lung carcinoma.

BACKGROUND: Deletions in the short arm of chromosome 3 (3p) are present in most lung carcinomas. OBJECTIVE: To investigate the role of these chromosome 3p deletions in the pathogenesis of non-small cell lung carcinomas. DESIGN: Seven archival, paraffin-embedded, surgically resected lung cancer specimens were studied. Fifty precisely identified malignant and preneoplastic lesions present in bronchi, bronchioles, and alveoli were microdissected from stained slides and analyzed for allele loss using polymerase chain reaction-based assays for dinucleotide repeat polymorphisms at three chromosome 3p loci (3p14, 3p21.3, and 3p25). SETTING: University-based medical center and affiliated hospitals. SUBJECTS: Samples were analyzed from seven patients who underwent surgical resection with curative intent for non-small cell lung cancer and whose specimens included extensive multifocal areas of preneoplastic lesions (hyperplasia, metaplasia, dysplasia, or noninvasive cancer). RESULTS: Lymphocytes from all seven cases were heterozygous (ie, informative) for all three microsatellites analyzed. Six (86%) of seven invasive cancers had loss of heterozygosity at one or more chromosome 3p sites. In the accompanying preneoplastic lesions, loss of heterozygosity was detected in none of two normal bronchioles, 13 (76%) of 17 hyperplasias, six (86%) of seven dysplasias, and four (100%) of four noninvasive cancers. Loss of heterozygosity was detected throughout the respiratory tract, in bronchi, bronchioles, and alveoli. In 18 (78%) of 23 preneoplastic lesions, the specific alleles lost were identical to those lost in the corresponding carcinomas. The probability of this happening by chance is 5.3 x 10(-3). CONCLUSIONS: Deletions in the short arm of chromosome 3 occur at the earliest stage (hyperplasia) in the pathogenesis of lung cancer and involve all regions of the respiratory tract. Allele loss is highly specific, but its mechanism remains unknown. Our findings may be of considerable biologic, prognostic, and clinical significance.

Aged↗

PubMed1995

Frequent loss of the short arm of chromosome 9 in resected non-small-cell lung cancers from Japanese patients and its association with squamous cell carcinoma.

We analyzed 87 Japanese non-small-cell lung carcinomas (NSCLC) including 30 squamous cell, 51 adenocarcinomas and 6 large-cell carcinomas for loss of heterozygosity (LOH) on the short arm of chromosome 9, and we correlated our findings with clinicopathological features. We used four polymorphic microsatellite markers on 9p (interferon A gene, D9S171, D9S126, and D9S169), which flank the critical region (9p21-22) involved in lung cancer. We observed alterations of DNA sequences at 9p in NSCLC (27 of 82 informative cases or 33%). Concordance among the four markers was high (87%), indicating that the deletions often were relatively large. The 27 genetic alterations observed on 9p include 26 examples of LOH, 1 homozygous deletion, and 1 case with LOH and evidence of microsatellite alteration characterized by shift in band mobility. We noted a high frequency of LOH at 9p especially in squamous cell carcinoma (17 of 29 informative cases or 59%), and in poorly differentiated NSCLC (12 of 23 informative cases or 52%). There was no correlation between LOH at 9p and the other clinical parameters, including survival, gender, tumor size and the presence of regional or distant metastases. In contrast to other reports, we found only rare instances of homozygous deletions (1%) and microsatellite alteration showed as a mobility shift (1%). Our findings demonstrate that LOH at the short arm of chromosome 9 is correlated with squamous cell and poorly differentiated carcinomas in Japanese patients with NSCLC.

Base Sequence↗

PubMed1995

Age-related differences in the distribution of peripheral atherosclerosis: when is atherosclerosis truly premature?

BACKGROUND: The natural history of peripheral atherosclerosis in young adults appears to be unfavorable compared with that in older patients. No universally accepted definition of "premature" atherosclerosis exists, however, making comparison of clinical studies difficult. This study examined age-related differences in distribution of atherosclerotic lesions and determined an age threshold at which such differences became apparent. Such a threshold may provide a definition of premature atherosclerosis. METHODS: Arteriograms of all patients 49 years of age and younger undergoing evaluation of lower extremity ischemia during the past 5 years were reviewed and the findings were tabulated. Medical records were reviewed to obtain demographic data, assess risk factors, and confirm disease etiology. Exclusion criteria included normal arteriograms (three patients), history of acute or remote trauma (six patients), unclear cause of ischemic symptoms (three patients), arteritis (four patients), aneurysmal disease (one patient), and acute ischemia without prior chronic symptoms (12 patients). For comparison we also reviewed arteriograms performed during the same period in 140 patients older than 50 years of age who had chronic lower extremity ischemia caused by atherosclerosis. RESULTS: The mean age of the 59 study patients was 43.4 +/- 5.8 years (median age, 46 years; range, 25 to 49 years). Arteriograms were available in all cases; medical records were available in 54 (92%). Atherosclerosis involved only the aortoiliac segment in 25 patients (42%), the femoropopliteal-tibial arteries alone in 21 (36%), and both levels in 13 (22%). Patients with distal atherosclerosis had a higher prevalence of diabetes than those with proximal atherosclerosis (p = 0.004). Ninety-two (66%) of the 140 patients older than 50 years of age had atherosclerosis confined to a single arterial segment, which was not significantly different from the prevalence of single-level disease in the study group. However, 25 (54%) of the 46 study patients with single-level atherosclerosis had aortoiliac disease compared with only 15 (16%) of 92 patients older than 50 years of age with single-level disease (p < 0.001). CONCLUSIONS: In contrast to the pattern of disease in older adults, atherosclerosis in young, nondiabetic patients most commonly involves the aortoiliac segment. Differences in lesion distribution become increasingly apparent with age but are most striking between those 49 years of age and younger and those 50 years of age and older. Accordingly, we propose that premature peripheral atherosclerosis be defined as beginning at or before the age of 49 years.

Adult↗

PubMed1995

Predicting survival in fulminant hepatic failure using serum Gc protein concentrations.

Plasma Ge protein sequesters actin released into the circulation after massive hepatocyte necrosis, but is greatly depleted in the process. In fulminant hepatic failure (FHF), Gc is present in serum both as a complex with actin and as unbound protein, the latter becoming completely exhausted in those patients with the most severe FHF. In the present study, 47 consecutive patients with FHF, 39 of whom were the result of acetaminophen (AC) overdose, were evaluated to determine whether measurement of Gc protein levels could be used to predict survival. Using serum samples obtained shortly after admission as well as later samples, levels for total Gc protein, percentage of Gc complexed with actin, and calculated unbound Gc remaining in serum were compared for survivors and those who died of their illness. The most marked changes were present in unbound Gc levels in nonsurvivors, the mean of which for follow-up samples was 10% of normal mean values, as compared with 23% of normal mean values in those who survived (P < .01). Using a cutoff value for unbound Gc protein of > or = 34 micrograms/mL to predict survival, outcome was correctly predicted in 32 of 47 (68%) patients using early samples, and in 24 of 27 (89%) patients using later sera. No differences were observed between values and/or outcome in AC and non-AC cases. Measurement of Gc protein level correctly predicted all patients dying of hepatic failure. This single measurement compares favorably with multifactorial predictive models, such as the King's College model, and might be a useful test for patients being considered for transplantation.

Forecasting↗

PubMed1994

Validation of a clinical prediction rule for the differential diagnosis of acute meningitis.

OBJECTIVE: To attempt to validate a previously reported clinical prediction rule derived to assist in distinguishing between acute bacterial meningitis and acute viral meningitis. DESIGN: Retrospective chart review of patients treated at five hospitals between 1981 and 1990. The criterion standard for bacterial meningitis was a positive cerebrospinal fluid (CSF) or blood culture or a positive test for bacterial antigen in the CSF. For viral meningitis, the criterion standard was a positive viral culture from CSF, stool, or blood or a discharge diagnosis of viral meningitis with no other etiology evident. SETTING: Two Department of Veterans Affairs (VA) hospitals, two county hospitals, and one private hospital, each affiliated with one of two medical schools. PATIENTS: All persons aged more than 17 years who were hospitalized over a ten-year period at one of five academically affiliated hospitals for the management of acute meningitis. MEASUREMENTS AND MAIN RESULTS: Sixty-two cases of bacterial meningitis and 98 cases of viral meningitis were confirmed. With all patients included, the discriminatory power of the model as measured by the area under the receiver operating characteristic curve (AUC) was 0.977 (95% CI, 0.957-0.997), compared with the AUC of 0.97 in the derivation set of the original publication. The AUCs (95% CIs) for data subsets were: Dallas cases 0.994 (0.986-1.0). Milwaukee cases 0.912 (0.834-0.990); ages 18-39 years 0.952 (0.892-1.0), ages 40-59 years 0.99 (0.951-1.0), and age > or = 60 years 0.955 (0.898-1.0). CONCLUSIONS: The authors conclude that the clinical prediction rule proved robust when applied to a geographically distinct population comprised exclusively of adults. There was sustained performance of the model when applied to cases from each city and from three age strata. Prospective validation of this prediction rule will be necessary to confirm its utility in clinical practice.

Acute Disease↗

PubMed1994

Maternal youth and pregnancy outcomes: middle school versus high school age groups compared with women beyond the teen years.

OBJECTIVE: We sought to measure and compare pregnancy complications in middle school versus high school versus older maternal age groups. STUDY DESIGN: From January 1988 through December 31, 1991, maternal and infant data from 16,512 consecutive nulliparous women were collected and electronically stored. These women were divided into three study groups: middle school (11 to 15 years old), high school (16 to 19 years old), and women 20 to 22 years old at delivery. Statistical analysis included logistic regression to control for potentially confounding demographic variables. RESULTS: Middle school-aged mothers were disproportionately black (50% vs 36% Hispanic vs 14% white), and very low birth weight (4% vs. 2%, p = 0.003) was increased in these youthful mothers. First births to high school-aged mothers were not found to be compromised compared with those of women 20 to 22 years old, and, indeed, cesarean birth was less frequent in these women compared with those > or = 20 years old. CONCLUSIONS: We conclude that the health hazard associated with school-age pregnancy is predominantly prematurity and is increased only in middle school-aged mothers. High school-aged mothers do not experience excess medical complications of pregnancy compared with older women. We suggest that middle school pregnancy, particularly for inner-city teenagers, should be a special focus for pregnancy prevention and intervention.

Adolescent↗

PubMed1994

Use of universal precautions in interventional radiology: results of a national survey.

OBJECTIVE: To determine current use of universal precautions by practicing interventional radiologists in the United States. METHODS: National survey mailed to interventional radiologists, conducted anonymously in November 1991. Of 1530 survey forms mailed to practicing interventional radiologists, 817 (53%) were returned and 804 (52%) were completed and evaluable. Both academic and private practice settings were represented. RESULTS: Eighty-five percent of respondents had changed their use of infection control measures in the previous 10 years. Of these, 96% cited personal concerns about AIDS as a reason for making changes. Sixty-two percent made changes in response to Centers for Disease Control and Prevention and Occupational Safety and Health Administration recommendations as well. Use of barrier precautions was quite variable. Although 86% of respondents always wore a sterile gown during procedures, only 32% routinely wore a face mask or shield and only 29% of those who did not wear corrective glasses routinely wore protective eye gear during procedures. Seven percent of respondents routinely double gloved for procedures. Twenty percent of reported percutaneous injuries occurred during recapping of used sharps; an additional 6% were related to improper disposal of used sharps. CONCLUSIONS: We conclude that use of universal precautions by interventional radiologists in the United States is variable. Some practices that may lead to preventable injury to health care workers remain common.

Acquired Immunodeficiency Syndrome↗

PubMed1994

Ultrasonographic evaluation of central and end-organ hemodynamics in antepartum pyelonephritis.

OBJECTIVE: Our purpose was to evaluate central and end-organ hemodynamic effects of antepartum pyelonephritis. STUDY DESIGN: Daily duplex ultrasonographic assessments of maternal cardiac output and resistive index values of the maternal renal and uterine arteries and the fetal umbilical arteries were performed in pregnant women admitted for acute pyelonephritis. For comparison, the same measures were repeated within 2 weeks after discharge. RESULTS: Thirty-seven women with antepartum pyelonephritis underwent serial 2-dimensional real-time and Doppler evaluation of maternal heart and duplex Doppler evaluation of maternal renal and uterine and fetal umbilical arteries. Significant differences in temperature, mean arterial pressure, and heart rate were observed during hospitalization compared with the follow-up visit. Total peripheral resistance was significantly decreased and cardiac output increased during acute infection. In women with unilateral signs and symptoms an increased resistive index was observed in the symptomatic kidney compared with the nonsymptomatic side; this difference disappeared on the follow-up study. No changes were observed in maternal uterine or fetal umbilical arteries. CONCLUSIONS: Uncomplicated pyelonephritis is associated with measurable depression of systemic vascular resistance. This likely represents an effect of infection that in the extreme would be the septic shock syndrome. It seems reasonable to attribute the increased resistive index of the symptomatic kidney to local effects of infection.

Acute Disease↗

PubMed1994

Cell size and the heat-shock response in rat brain.

The expression of mRNAs encoding two members of the heat-shock protein 70 family, the constitutively-expressed heat-shock cognate (hsc70) mRNA and the strictly heat-inducible (hsp70) mRNA, was quantitated in cerebellar and hippocampal cells of rats 3 h after amphetamine-induced or heat-induced hyperthermia. Intracellular heat-shock mRNA levels in specific cell types were compared with those of total polyadenylic acid [poly(A)] mRNA or 18S rRNA in the same cell type. Levels of poly(A) mRNAs, 18S rRNAs, and hsc70 mRNAs were highest in large neurons and lowest in glia. hsp70 mRNAs were also present at highest levels in large neurons, suggesting that hsp70 mRNAs accumulated as rapidly in these cell types as they did in small neurons and glia. However, compared with levels of intracellular poly(A) mRNAs or levels of rRNAs, large neurons contained two- to 12-fold lower levels of hsp70 mRNAs than neurons of intermediate size and five- to 30-fold lower levels than glia. These results suggest that hsp70 mRNAs accumulated as rapidly in large neurons as in small neurons and glia, but that the large size of these neurons precluded intracellular hsp70 mRNA concentrations increasing as quickly. The susceptibility of large neurons to stress-induced cell death could be due, in part, to their inability to synthesize rapidly hsp70 in sufficient amounts to protect these cells from the initial molecular consequences of stress.

Amphetamine↗

PubMed1994

Analyzing and adjusting for variables in a large-scale standardized-patient examination.

BACKGROUND: Structuring a clinical performance examination that uses standardized patients (SPs) for large groups of examinees often involves the use of two or more parallel forms of the examination with different SPs portraying the same case on the different forms. In addition, each form may be administered more than once on different days and/or in different locations. METHOD: To determine the effects of critical variables, such as day of examination, time of day (AM/PM), which of two simultaneous forms were taken, and sequencing effects, a univariate nested factorial analysis of variance was conducted for each of four annual SP examinations (1990-1993) at the University of Texas Southwestern Medical School. The examinations were given to approximately 200 second-year students per year at the end of their Introduction to Clinical Medicine course, and were graded on a pass/fail basis. RESULTS: Statistically significant differences were found for the following variables: (1) time of day (AM or PM) and day were significant but were inconsistent and of small magnitude; (2) sequencing for the first two stations was significant in each form of the examination and in all four years; and (3) form-within-case differences (i.e., differences between SPs) were significant between the two forms of the examination in each year of administration. To minimize the impacts of these variables, two mean equating formulas were applied to the scores. Few examinees' pass/fail status would have been affected by either adjustment. CONCLUSION: The parallel-forms examination format is minimally affected by the variables evaluated and is a fair pass/fail assessment of a student's performance. Mean equating is a valuable tool in minimizing the possibly unfair impact of variables on pass/fail decisions for homogeneous student populations.

Analysis of Variance↗

PubMed1994

Reference citations in radiology: accuracy and appropriateness of use in two major journals.

OBJECTIVE: Errors in reference citation and use are common in the medical and scientific literature. The prevalence of such errors in the radiology literature has not been reported. We did a study to assess the accuracy and appropriateness of use of references cited in two general radiology journals. MATERIALS AND METHODS: All references cited in the June 1993 issues of the American Journal of Roentgenology and Radiology were numbered consecutively. Fifty references were chosen at random from each journal, and copies of the original publications were obtained from the medical library at our institution or through interlibrary loan. Each reference was studied for accuracy and appropriateness of its citation in the June 1993 journal article (the "index article"). Errors were classified as major or minor in each category. Data were analyzed with the SAS statistical package. RESULTS: Forty-seven (94%) of 50 references were obtained from AJR, and 48 (96%) of 50 from Radiology. Of the 47 from the AJR, one (2%) had a major error and 21 (45%) had a minor error in accuracy. Of the 48 from Radiology, two (4%) had a major error and 11 (23%) had a minor error in accuracy. These values were significantly different for minor errors (p = .0188), but not for major ones (p = 1.000). When we adjusted for index article type, error rates for the two journals were not significantly different (p = .0612). We found four major errors (9%) and two minor errors (4%) in appropriateness of citation in the AJR references we studied. Three references (6%) from Radiology contained major errors in appropriateness of use; we found no minor errors of that type. These values were not significantly different (p = .232 for minor errors; p = .709 for major errors). One error in accuracy prevented location of the original reference. Errors were not related to the number of references cited in an index article (p = .528 for accuracy; p = .092 for appropriateness). CONCLUSION: The rate of minor errors in accuracy of references is fairly high in the two journals studied and is comparable to rates previously reported for other types of journals. The rate of major errors in accuracy of references is slightly lower than rates for other types of journals. The percentage of cited references that could not be located was also smaller than in previous reports. Errors in citation appropriateness were less common as well. Given the small number of errors that prevented references from being located, significant expenditure of time and money by journal staff members in checking references is probably not justified. However, authors should be encouraged to exercise greater care in checking all of their references for both accuracy and appropriateness of use. Differences in error rates between AJR and Radiology may have resulted in part from the random sampling method, which produced different mixtures of index articles for the two journals.

Bibliographies as Topic↗

PubMed1993

Postpartum perineal morbidity after fourth-degree perineal repair.

OBJECTIVE: We attempted to determine the frequency of postpartum perineal morbidity (dehiscence, infection, and rectovaginal fistula) in women after fourth-degree perineal repair. STUDY DESIGN: The medical records of 390 women at Parkland Memorial Hospital with fourth-degree perineal repair during 1989 and 1990 were retrospectively reviewed in a case-cohort study. Statistical analysis included chi 2 contingency tables, Fisher exact test, Mann-Whitney test, and analysis of variance. RESULTS: Twenty-one of 390 women (5.4%) had postpartum perineal morbidity. Seven (1.8%) had dehiscence alone, 11 (2.8%) had infection and dehiscence, and 3 (0.8%) had infection alone. Overall there were 18 dehiscences (4.6%) and 14 infections (3.6%) in the total group with perineal morbidity. Two high rectovaginal fistulas were concomitantly detected in women with perineal dehiscence. Only shoulder dystocia, metritis, and postpartum fever occurred significantly more frequently in patients with postpartum perineal morbidity than in women without perineal morbidity. Smoking and human papillomavirus infection were not associated with perineal repair morbidity. CONCLUSIONS: Postpartum perineal morbidity after fourth-degree perineal repair is an uncommon event. It is not predicted by readily preventable antepartum or intrapartum factors.

Adult↗

PubMed1993

Muscle proton T2 relaxation times and work during repetitive maximal voluntary exercise.

We studied the effects of progressive maximal voluntary handgrip contractions (MVCs) on muscle proton spin-spin (T2) relaxation times and work, measured as the integrated force vs. time curve (FTI). Six healthy volunteers performed 10, 20, 40, and 80 MVCs in a 0.35-T magnet on four separate occasions. Repeated measures analyses of variance of increases in T2 and FTI during successive bouts were significant (P < 0.005 and P < 0.001, respectively). FTI increased with successive bouts to a greater extent than did muscle T2 (P < 0.05). For T2, the Helmert contrast judged the 10-MVC response lower than the mean of the remaining responses (P < 0.005), and the differences between all others compared with the means of subsequent responses were not significant, indicating a "flattening" of the T2 response after the increase from 10 to 20 repetitions. For FTI, all the single degree of freedom Helmert contrasts were significant (P < 0.001), indicating a continual increase in response over increased MVCs. The curved nature of the T2 response conformed best to a hyperbolic function, suggesting that a limit of approximately 32% exists for the change in T2 during progressively longer bouts of MVCs. A limit in the T2 response is consistent with the existence of a limit in the amount of water that muscle can take up from the vasculature during exertion.

Adult↗

PubMed1993

Needle-stick injuries and blood contacts during invasive radiologic procedures: frequency and risk factors.

OBJECTIVE: Possible nosocomial transmission of blood-borne pathogens is a serious concern for health care workers and patients alike. Needle-stick injuries and blood contacts pose a risk of pathogen transmission during procedures. We performed a study to determine the frequency of injuries and blood contacts during invasive radiologic procedures and to examine procedure-related factors that may increase risk of injury or exposure. SUBJECTS AND METHODS: A prospective study of needle-stick injuries and blood contacts during invasive radiologic procedures was performed. During a 10-week period, information about procedures was recorded by technologists or physicians, and needle-stick injuries and exposures to patients' blood and body fluids were noted. Data were analyzed with the SAS statistical package. RESULTS: Accidental exposure to patients' blood and body fluids occurred in 15 of 501 cases (3.0%; 95% confidence interval, 1.7-4.9%). Of 729 operators at risk, 15 were exposed (2.0%; 95% confidence interval 1.1-3.3%). Exposure was parenteral in one case and cutaneous in 14. Risk of exposure was correlated with procedure duration (p = .003), but not with emergency vs elective procedure status (p = .796), procedure type (p = .275), or operator experience level (p = .554). Three needle-stick injuries (0.6% of cases) occurred, all with sterile instruments; bleeding occurred in two cases. Risk of injury was correlated only with procedure type (p = .046). In no case was a patient exposed to a physician's blood. CONCLUSION: Whereas cutaneous exposure of physicians to patients' blood was not infrequent, parenteral exposure was rare in this series. Most of the exposures in this study could have been prevented by the use of protective equipment. Patients' contact with physicians' blood did not occur in this study.

Blood↗

PubMed1993

Class A1 gestational diabetes: a meaningful diagnosis?

OBJECTIVE: To compare pregnancy outcomes in women diagnosed as having class A1 gestational diabetes with those of a group with a normal 3-hour glucose tolerance test (GTT) to assess morbidities attributable to glucose intolerance. METHODS: Selective 50-g GTT identified pregnant women who received a 3-hour GTT. Over a 16-month period, 159 women were diagnosed as having class A1 gestational diabetes according to the National Diabetes Data Group criteria. During the latter 12 months of this time period, 151 women who had a normal GTT result were identified for comparison. RESULTS: There were statistically significant differences in age and the development of peripartum hypertension in women with class A1 gestational diabetes compared with the normal 3-hour GTT group. There were no significant differences in any neonatal outcome variable, including percent delivering large for gestational age (LGA) neonates in women with A1 diabetes compared to controls. Overall, 111 (36%) of the 310 neonates were classified as LGA, a rate more than double that in the singleton population in our hospital. Maternal weight, parity, and a history of a previous macrosomic infant were significantly associated with LGA outcome. Mean maternal weight was the same in the two GTT groups, implying an independent effect on fetal size. Obstetric interventions were not significantly different between the groups, so differences in intervention could not account for the lack of difference in outcome variables. The impact of dietary counseling in the class A1 diabetic women is also an unlikely explanation for the lack of differences in outcome. Within the normal-GTT group, women with one abnormal 3-hour value had a frequency of LGA infants similar to that of women with all normal 3-hour GTT values. These results suggest that there is a selection effect of screening for glucose intolerance that may relate more to other risk factors for LGA outcome than to glucose intolerance. Maternal obesity is an independent and more potent risk factor for large infants than is glucose intolerance. CONCLUSION: The diagnosis of class A1 gestational diabetes is not significantly associated with obstetric and perinatal morbidities. A nondiscriminating diagnostic test undermines the validity of population screening for glucose intolerance.

Adult↗

PubMed1992

Disease-specific patterns of locus coeruleus cell loss.

Computer visualization techniques were used to map and to quantitatively reconstruct the entire locus coeruleus, including the nucleus subcoeruleus, to compare the topographic patterns of cell loss in postmortem brains from patients with Parkinson's disease, Alzheimer's disease, and Down syndrome. There was comparable cell loss in all three diseases (approximately 60%) compared with aged normal subjects, and there was a significant loss of nucleus subcoeruleus cells specifically in patients with Parkinson's disease (63%). There was a significant positive correlation between the magnitude of locus coeruleus cell loss and the duration of Alzheimer's disease, but no such correlation was found for Parkinson's disease. In patients with Parkinson's disease, there was comparable cell loss throughout the rostral-caudal extent of the nucleus; however, in patients with Alzheimer's disease and Down syndrome, the greatest cell loss always occurred within the rostral portion of the nucleus, with a relative sparing of caudal cells. These data are consistent with the hypothesis that cell loss in Parkinson's disease is the result of a pathological process that attacks the catecholaminergic cells of the locus coeruleus and the subcoeruleus in general; in Alzheimer's disease and Down syndrome, however, the pathological process only affects the rostral, cortical-projecting locus coeruleus cells and spares the caudal, noncortical-projecting cells.

Aged↗

PubMed1992

Factors affecting the dose response to oxytocin for labor stimulation.

For nearly 40 years synthetic oxytocin has been used for labor stimulation by titrating dosage rate to uterine contractions. We used a computerized data base to determine variables affecting the dose response to oxytocin in 1773 pregnancies. Statistically important predictors of required oxytocin dosage included cervical dilatation, parity, and gestational age. Maternal body surface area was found to be associated with a higher oxytocin dosage in women undergoing induction of labor. However, the broad range of the statistical confidence intervals precluded prediction of a given pregnancy's oxytocin requirement.

Dose-Response Relationship, Drug↗

PubMed1992

Occult glove perforations: frequency during interventional radiologic procedures.

Because the intact surgical glove is an important barrier against exposure to blood and other body fluids, occult glove perforations occurring during procedures may have implications for infection control and protection of health care workers. Although the frequency of occult glove perforations during surgery has been studied, no such data have been reported for interventional radiology. This study was designed to determine the frequency of occult glove perforations in interventional radiology. Gloves used during interventional radiologic procedures were collected and tested for occult perforations according to previously accepted methods. The frequency of occult defects in unused gloves was also determined. A form completed for each pair of gloves indicated length of use, awareness of perforations, and information about the procedure. The anatomic distribution of perforations was also studied. Occult perforations were found in 49 (10%) of 492 used gloves. The frequency of defects in unused gloves was 1% (2/160). Gloves worn fewer than 2 hr had a perforation rate of 7% (29/406), and those worn 2 hr or longer had a rate of 23% (20/86; p less than .0001). Perforations were noticed by the wearer in only three (6%) of the 49 perforations. The perforation rate for inner gloves of a double-glove set was 3% (1/34; the corresponding outer glove also was perforated). Although the 10% rate of occult glove perforation during interventional radiologic procedures found in this series is lower than rates described with surgical procedures, it is not insignificant. The significant increase in the rate of perforation when gloves are worn more than 2 hr suggests that gloves should routinely be changed at or before 2 hr of wear, particularly in procedures involving high-risk patients.

Equipment Failure↗