Biomedical subjects
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Computed tomography (CT) was performed in 338 active professional boxers. CT scans were abnormal in 25 boxers (7%). The most common CT abnormality was brain atrophy (22 cases). Focal lesions of low attenuation consistent with posttraumatic encephalomalacia were noted in only three boxers. Boxers with abnormal CT scans did not differ from those with borderline or normal CT scans in regard to age, win-loss record, number of bouts, or history of an abnormal electroencephalogram. Thirty-seven boxers with borderline CT scans (49%) and 17 with abnormal CT scans (68%) reported a previous technical knockout (TKO) or knockout (KO), compared with only 89 (37%) of the 238 boxers with normal CT scans (P < .01). Brain atrophy was noted more frequently in boxers with a large cavum septum pellucidum (CSP) than in those with a small or no CSP (P < .05). Boxers with abnormal or borderline CT scans who experienced a TKO or KO were slightly older than those with normal CT scans and a history of a TKO or KO (P < .05).
OBJECTIVE: To determine the yield and morbidity of comprehensive restaging laparotomy in women with presumed early ovarian carcinoma who have undergone incomplete initial staging procedures. METHODS: We conducted a retrospective review of 30 women with apparent early ovarian carcinoma who underwent a comprehensive restaging laparotomy including multiple random intraperitoneal biopsies and selective pelvic/para-aortic lymphadenectomy before receiving adjuvant therapy. Positive findings were compared with clinicopathologic features. RESULTS: Only 17% of patients had adequate skin incisions, 53% had pelvic washings, and 37% had omental biopsy at primary surgery. Complications of restaging laparotomy included 53% severe adhesions, 20% bowel complications, and 20% vascular complications requiring suture. Nine patients (30%) had disease upstaged and six (20%) had stage III disease established by comprehensive restaging laparotomy. Two-thirds of the upstaged patients had occult metastases identified only through cytology, random peritoneal biopsies, or selective lymphadenectomy. Women with poorly differentiated or papillary serous lesions were more likely to have disease upstaged than those with well- and moderately differentiated lesions or other histologic types (P < .05). Other clinicopathologic features did not predict upstaging. CONCLUSION: A comprehensive staging laparotomy is needed to detect occult metastatic disease in women with apparent early ovarian carcinoma.
Based on self-reported family histories, a sample of 1,270 adolescents were categorized into one of three groups: a) family history of alcoholism (FHA), b) family history of heavy drinking (FHHD), and c) family history symptom free (FHSF). These subjects were assessed on 26 measures tapping intra- and interpersonal competence at three points in time. Results of repeated measures (test time) ANOVAs revealed that FHA subjects (as compared to the two other groups) exhibited greatest levels of stress due to their inability to get along with others and the lowest level of attachment to their parents. Over the three test times, FHA subjects appeared to maintain an inappropriately low level of social orientation and display decreases in self-efficacy, goal directedness, and the level of trust and respect for their parents. Children of heavy-drinking, nonalcoholic parents also exhibited low levels of school achievement motivation and social orientation. The alcohol/drug use pattern of the subject was found to be associated with more measures of competence than was family drinking background. Examination of the relationship of varying levels of substance use and competence measures by age group revealed that deficits are not static during the span of adolescence through young adulthood.
In the past several years, image processing techniques based on Bayesian models have received considerable attention. In our earlier work, we developed a novel Bayesian approach which was primarily aimed at the processing and reconstruction of images in positron emission tomography. In this paper, we describe how the technique has been adopted to process magnetic resonance images in order to reduce noise and artifacts, thereby improving image quality. In this framework, the image is assumed to be a statistical variable whose posterior probability density conditional on the observed image is modeled by the product of the likelihood function of the observed data with a prior density based our prior knowledge. A Gibbs random field incorporating local continuity information and with edge-detection capability is used as the prior model. Based on the formalism of the posterior density, we can compute an estimate of the image using an iterative technique. We have implemented this technique and applied it to phantom and clinical images. Our results indicate that the approach works reasonably well for reducing noise, enhancing edges, and removing ringing artifact.
A model of chronic left ventricular dysfunction characterized by left ventricular dilation, elevated filling pressures and histologic changes has been lacking. In this study the use of coronary microsphere embolization-induced ischemia was explored as a method of producing chronic left ventricular dysfunction. Acute ischemic left ventricular dysfunction was induced in 13 mongrel dogs with 50 microns plastic microspheres until the peak positive first derivative of left ventricular pressure (dP/dt) decreased by 25% and the left ventricular end-diastolic pressure increased to greater than or equal to 12 mm Hg. After 8 weeks of observation, hemodynamic and echocardiographic variables were measured in each dog. Acute left ventricular dysfunction resulted in a dilated left ventricle with systolic dysfunction (area ejection fraction 24 +/- 6% vs. 57 +/- 9% initially, p less than 0.01) and elevated left ventricular filling pressures. Isovolumetric relaxation was prolonged and the peak rapid filling/atrial filling velocity and integral ratios were reduced. Eight weeks after embolization, there was an increased left ventricular size (end-diastolic area 15.1 +/- 2.1 cm2 at 8 weeks vs. 13.5 +/- 1.4 cm2 early after microsphere injection, p less than 0.05), unchanged end-systolic area, improved area ejection fraction and increased left ventricular mass. Left ventricular end-diastolic pressure increased and, despite continued abnormal relaxation, the peak rapid filling/atrial filling velocity and integral ratios increased to above baseline values, demonstrating a "restrictive" pattern. Gross and histologic examination revealed diffuse, patchy scarring associated with perivascular fibrosis. Thus, coronary microsphere embolization resulted in a model of chronic moderate left ventricular systolic dysfunction and abnormal diastolic function characterized by a "restrictive" filling pattern.
Thromboembolic events occur with a frequency of 3-5% in children with nephrotic syndrome (NS). Although numerous abnormalities in all phases of coagulation have been described in NS, the pathogenesis of clotting abnormalities remains poorly understood in this group of patients. We describe a child with long-standing NS in whom a severe deep venous thrombosis and pulmonary embolism secondary to acquired protein S deficiency and a strong lupus-type circulating anticoagulant developed. In addition, this patient had a markedly decreased plasma level of C4b binding protein. Although acquired protein S deficiency has been described in various clinical disorders including NS, our patient is unusual in having C4bBP deficiency, and his is the only reported pediatric case of NS complicated by thromboembolism in which a circulating anticoagulant has been implicated, to our knowledge.
This study examines the overall and relative contributions of a variety of family environment measures to a child's alcohol, marijuana and other drug use, delinquent activity, and dysfunctional methods of coping with problems. The family environment variables tapped aspects of parental behaviors and attitudes, parenting styles, and family harmony and cohesion. Data were collected as part of a prospective, longitudinal study that examined the acquisition and maintenance of a variety of behaviors. Data were gleaned at two points in time, spanning 3-year intervals, from subjects ranging in age from early to late adolescence. In general, alcohol use among the younger subjects was more strongly determined by the use and attitudes of the same sex parent. In contrast, among older subjects, father's alcohol use was important to the offspring's use. While models predicting illicit drug use and the extent of problems related to alcohol and marijuana use fared least well, it was generally found that hostility and lack of warmth on the part of the parents contributed most to these outcomes in subjects. Finally, hostility displayed by both parents helped to determine the incidence of delinquency among sons and the use of dysfunctional coping methods among sons and daughters.
Wilson's disease (WD) is an autosomal recessive disorder of copper accumulation leading to liver and/or brain damage. Although fatal if untreated, the condition can be treated effectively. Autosomal recessive inheritance indicates that siblings of affected patients are at 25% risk of having the disease. If they are diagnosed prior to becoming symptomatic, affected siblings can be kept free of symptoms by prophylactic therapy. In this paper we have examined the utility of copper-related variables, along with other clinical and molecular findings, in identifying those siblings of affected patients who should be further evaluated with a liver biopsy. Data are presented on a series of 13 presymptomatic patients in whom we have made the diagnosis of WD based on liver biopsy findings. Signs of liver disease were present in 12 out of 13 cases. The classic, noninvasive, screening approaches that we evaluated were not adequate to identify all cases of WD in this group of patients. These included positive Kayser-Fleischer (KF) rings, elevated liver serum alanine transferase, elevated urine copper, or elevated plasma nonceruloplasmin copper. We have introduced the use of molecular genetics for screening siblings of affected patients for WD. We show that a probe from the linked retinoblastoma (RB) gene can be very helpful in problem cases. However, at this time, the quantitative determination of liver copper concentration remains as the definitive diagnostic criterion.
Zinc therapy in Wilson's disease is a lifelong treatment to prevent reaccumulation of copper. Previous reports have shown that in normal male subjects, zinc ingestion has reduced high-density lipoprotein cholesterol level. This finding raises the possibility that lifelong zinc therapy could be atherogenic. In the present work, the effects of zinc therapy on serum lipids over a period of years is evaluated in patients with Wilson's disease. Zinc therapy reduces total cholesterol level by about 10% in both sexes and reduces high-density lipoprotein cholesterol level by about 20% in male patients. The mechanisms of these interesting effects of zinc on cholesterol metabolism are unknown. The coronary heart disease risk factor is not changed significantly by zinc therapy in either sex, and further, it remains below average in these patients after zinc therapy. We conclude that zinc therapy in Wilson's disease is not atherogenic.
Inotropic and vasodilator therapy for congestive heart failure improve left ventricular systolic performance by different mechanisms. However, the nature and extent to which diastolic filling is altered have not been well described. Acute severe left ventricular dysfunction was induced in 21 dogs by severe left ventricular global ischemia produced by left main coronary artery microsphere embolization until left ventricular end-diastolic pressure was greater than or equal to 18 mm Hg. Dobutamine was infused in seven dogs until the peak positive first derivative of left ventricular pressure (dP/dt) increased by greater than or equal to 33%. Nitroprusside was infused in seven dogs until left ventricular end-diastolic pressure was less than 15 mm Hg. Seven dogs were observed for 1 h after the induction of acute severe left ventricular dysfunction and served as the control group. In all groups of dogs, severe left ventricular dysfunction resulted in left ventricular dilation, reduction in area ejection fraction, elevation of left ventricular end-diastolic pressure and an early redistribution of diastolic filling (increased 1/3 and 1/2 filling fractions) despite a markedly abnormal time constant of relaxation. No changes were noted in any variable after 1 h of observation in the seven control dogs. Nitroprusside reduced left ventricular size and filling pressure, increased cardiac output, improved relaxation and redistributed diastolic filling to later in diastole as characterized by a reduced 1/3 filling fraction (19.4 +/- 7.4% versus 51.4 +/- 10%, p less than 0.001). The pressure-area curve was shifted downward and leftward.(ABSTRACT TRUNCATED AT 250 WORDS)
We examined the continuity and stability of relational patterns among putative risk factors and measures of total drug use over the age period of 12 to 18. Using Marlatt's (1987) affect-based model of moderation versus dependence, risk factors were classified on the basis of their assumed relationships to (a) positive and negative affect and (b) low versus high constraint. It was hypothesized that two distinct developmental pathways characterize the emergence of drug use in a normal population sample of adolescents: one indicative of low constraint and a predominance of positive affect, the other indicative of low constraint and a predominance of negative affect. Results of principal components analyses generally support the hypothesis. Theoretical and methodological implications are discussed.
Data concerning adolescents' alcohol- and drug-using behaviors, as well as the drinking patterns of their parents, were obtained from a sample of 1,380 New Jersey youth born between 1961 and 1969. Initially tested between 1979 and 1981 at ages 12, 15 or 18, these subjects were retested two additional times at 3-year intervals (retest rate = 92%). We wished to determine if offspring of families exhibiting a positive history of alcoholism (FH+) reported a serious alcohol or drug problem (including seeking treatment) at a higher rate than those without such backgrounds (FH-). Analyses indicated that FH+ rates for a self-reported alcohol and/or drug problem were about twice the rate for FH- individuals and about 1.5 times as high as the base rate for the entire sample. However, there were no significant differences between the two groups of troubled youth in terms of alcohol or marijuana use patterns or the frequency of use-related negative consequences. Our data also illustrated that FH+ females were as likely as FH+ males to report a serious problem and that FH+ families reported a higher rate of having more than one troubled offspring. It is of special import that these results are based upon observations of a community-based sample of adolescents and young adults in contrast to studies relying upon clinical samples and retrospective reports.
Recent information has suggested that early diastolic filling may be influenced by the left ventricular filling pressure, especially in the failing left ventricle. Acute severe left ventricular dysfunction was induced in 14 dogs by severe left ventricular global ischemia produced by left main coronary artery microsphere embolization until the left ventricular end-diastolic pressure was greater than or equal to 20 mm Hg. To assess the importance of left ventricular filling pressure on left ventricular diastolic filling, nitroglycerin was infused and titrated to reduce left ventricular end-diastolic pressure to less than 15 mm Hg in seven dogs, whereas the remaining seven dogs were observed for 1 h after acute severe left ventricular dysfunction. In both groups of dogs, severe left ventricular dysfunction resulted in left ventricular dilation and elevation of end-diastolic pressure, reduction in area ejection fraction (echocardiographically determined) and an early redistribution of diastolic filling (increased filling fractions at one-third and one-half diastole) despite prolongation of the time constant of left ventricular pressure decline. Pressure-area plots shifted upward and rightward with severe left ventricular dysfunction and were unchanged at 1 h as were all other variables. Nitroglycerin infusion reduced left ventricular size and filling pressure, redistributed diastolic filling to later in diastole as characterized by reduced filling fraction at one-third diastole (left ventricular dysfunction 48.8 +/- 9.7%, nitroglycerin 17.9 +/- 7.9%, p less than 0.001) and shifted downward left ventricular pressure-area plots. Nitroglycerin also improved the time constant of relaxation (left ventricular dysfunction 83 +/- 15 ms, nitroglycerin 52 +/- 15 ms, p less than 0.001) and lengthened the diastolic filling period.(ABSTRACT TRUNCATED AT 250 WORDS)
Data concerning adolescent alcohol and drug using behaviors, as well as the drinking patterns of their parents, were obtained from a sample of 1,380 New Jersey youth born between 1961 and 1969. Initially tested between 1979 and 1981 at ages 12, 15 or 18, these subjects were retested between 1982 and 1984 (retest rate = 95%). We wish to describe the early differences in patterns of alcohol and drug use between offspring of families exhibiting a positive history of alcoholism (FH+) and those without such backgrounds (FH-). FH+ subjects are compared to three other groups from varying parental backgrounds (heavy drinking nonalcoholic parents, high stress families and symptom-free families) as regarding problem use. Several indicators of problem use (e.g., early onset of intoxication, frequent intoxication, escape drinking) were not found to be more prevalent among FH+ than FH- adolescents. Analyses indicate, however, that FH+ adolescents are more likely than FH- adolescents from symptom-free families to report experiencing problems/consequences related to both drinking and drug taking.
This study assessed the prevalence of driving under the influence of alcohol and marijuana among a sample of 18 and 21 year olds and examined the across-time relationships between intoxicated driving and consumption, risk-taking/impulsive orientation, negative intrapersonal state, stress and use of alcohol and other drugs to cope with problems. Self-report data were collected from 556 men and women, ages 18 and 21, at two points in time. The data indicated that at least a minimum level of drinking and driving, as well as smoking marijuana and driving, is engaged in at least once for the majority of youth. Correlations between eight driving behaviors and consumption variables indicated that frequency of substance use was strongly related to frequency of driving while intoxicated (DWI). Regression analyses revealed that coping use of substances was the strongest predictor of driving under the influence. A path model examining the effect of stress, negative states and risk-taking orientations (T1) on driving under the influence as mediated through coping use (T2) was tested. Results showed that risk-taking orientation was the strongest predictor of DWI, both directly and indirectly (as mediated through coping use). Findings suggest that impaired driving may be part of a global syndrome of risk-taking behavior and is an activity engaged in most often by those who frequently use alcohol and other drugs to cope with problems.
A social learning model which incorporates measures from both the sociological perspective of differential association and the psychological perspective of behavior reinforcement is analyzed as an explanation of continued alcohol and marijuana use among youths. Data were gathered at two points in time from a sample of adolescents from New Jersey. The measurement and structural relationships among peer associations, attitudes, reinforcing and punishing consequences, and patterns of use were examined. It was found that, overall, the model fit the data for use of both substances, proving to be invariant across age and gender groups. The most pronounced difference between the alcohol and marijuana models was that differential associations exhibited the strongest relationship to maintenance of alcohol use while reinforcers were most salient to continued marijuana use.
The isolated perfused kidney of the guinea pig has been used to assess the mechanism that accounts for the maintenance of the positive phosphate (Pi) balance during development. The kidneys obtained from mature guinea pigs (n = 25) had a glomerular filtration rate (GFR) of 0.48 +/- 0.04 ml/min (mean +/- SE), whereas those of the newborn (n = 20) had a GFR of 0.15 +/- 0.02 ml/min. These values compare favorably with those observed in intact animals. The fractional excretion of Na+ (FENa) was 3.8 +/- 0.7% in the mature kidneys and 4.7 +/- 0.7% in the newborn kidneys. The maximal tubular reabsorption of Pi (TmPi) by the newborn kidney was 24.3 +/- 2.8 micrograms/min. The filtered load at which the TmPi of the newborn was reached exceeds by 2.5-fold the filtered load of Pi encountered under physiological conditions. In the adult the TmPi was 53.9 +/- 2.6 micrograms/min. The filtered load at which the TmPi of the adult was reached is only slightly higher than the average normal filtered load of Pi. The TmPi/GFR was significantly higher (P less than 0.02) in the newborn (117.4 +/- 10.8 micrograms X min-1 X ml-1 GFR) compared with the adult (82.6 +/- 3.6 micrograms X min-1 X ml-1 GFR). Moreover, at any filtered load of Pi below Tm the newborn animals reabsorbed twofold more Pi per gram kidney weight than the adult (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)