Screening for alcohol abuse using the CAGE questionnaire

A prospective study of 518 patients admitted to the orthopedic and medical services of a community-based teaching hospital during a six-month period was performed to test the hypothesis that a short, easily administered questionnaire would improve the detection rate by physicians of alcohol abuse. The CAGE questionnaire--a mnemonic for attempts to cut back on drinking, being annoyed at criticisms about drinking, feeling guilty about drinking, and using alcohol as an eye opener--was utilized as a screening instrument. The mean corpuscular volume of red blood cells, liver transaminase levels, and the gamma-glutamyl transpeptidase level were also evaluated as screening tests. The presence or absence of alcoholism and alcohol abuse for a consecutive sample of CAGE-negative patients and all patients answering "yes" to one or more of the CAGE questions was established through the administration of the Michigan Alcoholism Screening Test, a detailed chart review, and analysis of quantity of alcohol consumed. Diagnostic criteria were those described in the Diagnostic and Statistical Manual III. The prevalence of alcohol abuse was 20 percent. The mean corpuscular volume, gamma-glutamyl transpeptidase value, and liver transaminase levels were very insensitive as screening tests. In contrast, the CAGE questionnaire had a sensitivity of 85 percent and a specificity of 89 percent. Only 63 percent of the alcoholic subjects and alcohol abusers were detected by their physicians, and in only 24 percent of these cases did a physician address the problem with the patient. The CAGE questionnaire is a simple, sensitive, and specific screening test for alcohol abusers.

Neurotoxicity of polychlorinated biphenyls: structure-activity relationship of individual congeners

Neurotoxicity of Polychlorinated Biphenyls: Structure-Activity Relationship of Individual Congeners, Shain, W., Bush, B., Seegal, R. (1991). Toxicol. Appl. Pharmacol. 111, 33-42. Experimental and epidemiological data indicate that polychlorinated biphenyls (PCBs) may function as neurotoxicants. The mechanism(s) of action of PCBs in the brain is not well understood. One reason for our lack of understanding of PCB action in the central nervous system is that, in general, commercial mixtures of PCBs have been used for these experiments. We used a homogeneous cell line, PC12 cells, to investigate the relative potency of 43 individual PCB congeners. The neurotoxicant action of PCB congeners was measured as a decrease in cell dopamine content. We first described the potency of individual congeners; 2,2'-dichlorobiphenyl was the most potent congener (EC50 = 65 microM). The structure-activity relationships described in these experiments indicated that (i) congeners with ortho- or ortho-, para-chlorine substitutions were most potent; (ii) chlorination in a meta position decreased cell dopamine content in ortho-substituted congeners, but had little effect in ortho-, para-substituted congeners; and (iii) increasing congener chlorination did not correlate with a decrease in potency, though total chlorination of a ring appeared to reduce potency. Second, we determined that potency did not correlate with either cellular PCB content or gas chromatographic retention time. Finally, experiments with 2,2'-dichlorobiphenyl indicated that PCBs and not their metabolites were the toxicants. Thus, PCB congeners decrease cell dopamine content by interaction at specific sites that have preference for ortho- or ortho-, para-substituted congeners. The neurotoxic action of PCBs may occur by a different mechanism than PCB hepato- and immunotoxicity since these effects are most sensitive to non-ortho-substituted, dioxin-like, congeners.

Outcome after traumatic brain injury: pathway analysis of contributions from premorbid, injury severity, and recovery variables

OBJECTIVE

To examine the relationship of premorbid variables, injury severity, and cognitive and functional status to outcome 1 year after traumatic brain injury (TBI) and to assess the feasibility of multivariate path analysis as a way to discover those relationships.

DESIGN

Prospective, longitudinal.

SETTINGS

Level I trauma center, acute inpatient rehabilitation hospital.

PATIENTS

One hundred seven subjects (87 men, 20 women; mean age, 33.91 +/- 14.2 yr) who had experienced severe TBI, typically from motor vehicle crashes.

INTERVENTIONS

Acute medical and rehabilitation care.

MAIN OUTCOME MEASURES

Disability Rating Scale, Community Integration Questionnaire, and return to employment. Evaluated in acute rehabilitation, and at 6 and 12 months' postinjury.

RESULTS

Path analyses revealed that premorbid factors had significant relationships with injury severity, functional skills, cognitive status, and outcome; injury severity affected cognitive and functional skills; and cognitive status influenced outcome. No significant relationships were found between injury severity and emotional status, injury severity and outcome, emotional status and outcome, and functional skills and outcome.

CONCLUSIONS

Multivariate analysis is important to understanding outcome after TBI. Injury severity, as measured in this study, is less important to 12-month outcome than the premorbid status of the person and the difficulties (particularly cognitive deficits) exhibited at follow-up 6 months after the trauma.

Lightly chlorinated ortho-substituted PCB congeners decrease dopamine in nonhuman primate brain and in tissue culture

Exposure of the nonhuman primate, Macaca nemestrina, to Aroclor 1016, a commercial mixture of 26 lightly chlorinated PCB congeners, decreased dopamine concentrations in the caudate, putamen, substantia nigra, and hypothalamus. Only three ortho-substituted nonplanar PCB congeners (2,4,4', 2,4,2',4', and 2,5,2',5') were detected in these brain regions, suggesting that these congeners may be responsible for the observed decreases in dopamine. The ability of these and other PCB congeners to alter dopamine function was tested directly by applying them to dopamine-synthesizing cells in culture, PC-12 pheochromocytoma cells. In vitro testing demonstrated that these three congeners reduced cellular dopamine concentrations while planar, dioxin-like congeners, e.g., 3,4,3',4' and 3,4,5,3',4', did not. Thus, these ortho-substituted nonplanar congeners may be directly responsible for the observed changes in in vivo neurochemistry. Furthermore, these results suggest that the observed decreases in both in vivo and in vitro dopamine concentrations may occur through a novel mechanism and not through the Ah-receptor complex thought to mediate immunotoxic and hepatotoxic changes following exposure to dioxin and dioxin-like PCBs.

High-performance liquid chromatography of biogenic amines and metabolites in brain, cerebrospinal fluid, urine and plasma

A method for high-performance liquid chromatographic separation and electrochemical detection of biogenic amines and metabolites in a variety of biological matrices is described. The method employs either homogenization, precipitation or dilution followed by direct injection of the samples and permits the chromatographic resolution of dopamine, norepinephrine, epinephrine, serotonin (5-HT), 3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) in brain; 3-methoxy-4-hydroxyphenylglycol, DOPAC, 5-HIAA and HVA in cerebrospinal fluid; 5-HIAA, HVA and 5-HT in plasma; and 5-HIAA and HVA in urine. Alterations in chromatographic conditions, voltammetry and in vivo pharmacological manipulations are employed to verify the identity of the putative neurotransmitter and metabolite peaks in the biological samples.

Congener-specific distribution of polychlorinated biphenyls in brain regions, blood, liver, and fat of adult rats following repeated exposure to Aroclor 1254

Our previous in vitro studies with both isolated organelles and primary neuronal cell cultures found that intracellular signal transduction can be perturbed by some noncoplanar PCBs at exposure levels of </=10 microM. However, it is not clear whether such concentrations are achievable in brain in vivo. Also, the pattern of congener disposition and quantities of the PCB accumulation in tissues of animals exposed to commercial PCB mixtures is not well studied. In the present study, we have conducted PCB congener-specific analysis in different brain regions, liver, blood, and fat of adult male Long-Evans rats dosed orally with Aroclor 1254 (0 or 30 mg/kg/day; once per day, 5 days/week for 4 weeks) in corn oil. Twenty-four hours after the last dose, rats were euthanized, and the brains were removed and dissected to obtain cerebellum, frontal cortex, and striatum. Liver, blood, and fat samples were also collected at the same time. Congener-specific analysis of PCBs was performed by high-resolution gas chromatography with electron capture detection. While PCB concentrations in control rat brain regions were less than 0.02 ppm, total PCB congeners in treated animals accumulated to much higher levels. Total levels in the frontal cortex, cerebellum, and striatum were 15.1 +/- 0.3, 13.1 +/- 1.7, and 8.2 +/- 2.6 ppm, respectively. The levels of PCBs in the fat, liver, and blood were 0.041, 0.002, and 0.001 ppm in control rats and 552, 38.3, and 1.6 ppm in treated rats, respectively. In addition to the differential total uptake between tissues, there was differential accumulation of PCBs with respect to the number of chlorines. In all the tissues, the more lightly chlorinated (tetra- and penta-) congeners accumulated less than their respective proportions in the parent Aroclor 1254 mixture. On the other hand, heavily chlorinated (hexa- to nona-) congeners accumulated more than the proportion of these congeners found in Aroclor 1254 mixture. This shift toward accumulation of heavily chlorinated congeners seems to be more pronounced in the brain than liver and fat. Predominant congeners (5-32% of total PCBs) detected in different brain regions, blood, liver, and fat are: 2,3,3',4',5,6- (no. 163) + 2,2',3,4,4',5- (no. 138) (coeluted); 2,2',4,4',5,5'- (no. 153) + 2, 2',3,3',4,6'- (no. 132) (coeluted); 2,3,3',4,4',5- (no. 156) + 2,2', 3,3',4,4',6- (no. 171) (coeluted); 2,3',4,4',5- (no. 118); 2,2',4,4', 5-(no. 99); and 2,3,3',4,4'- (no. 105). These congeners together accounted for about two thirds of the total PCB load in brain. All these predominant congeners are ortho-substituted and therefore are noncoplanar in nature. The total PCB concentrations accumulated in brain were as high as 50 microM (based on average molecular weight of 326.4 for Aroclor 1254) and, at these concentrations, intracellular second messengers were significantly affected in neuronal cultures and brain homogenate preparations in vitro. These results indicate that concentrations that altered Ca2+ disposition and second messenger systems in vitro are achievable in brain in vivo following repeated exposure.

Comparison of effects of Aroclors 1016 and 1260 on non-human primate catecholamine function

Adult male non-human primates, Macaca nemestrina, were orally-exposed to corn oil or corn oil containing either Aroclor 1016 or 1260 at doses of 0.8, 1.6 or 3.2 mg/(kg.day) for 20 weeks. Brain concentrations of biogenic amines and individual PCB congeners were determined following exposure. Aroclor 1016 significantly decreased concentrations of dopamine and its metabolites in the caudate, putamen, substantia nigra and hypothalamus but did not alter neurotransmitter or metabolite concentrations in the globus pallidus and hippocampus. Total PCB concentrations ranged from 1 to 5 ppm with only three congeners detected (2,4,4'; 2,4,2',4' and 2,5,2',5') making up, on average, 72%, 18% and 7% respectively of the total residue in brain. There were no discernible differences in the congener make-up between brain regions. Aroclor 1260 reduced dopamine concentrations in the caudate, putamen and hypothalamus but produced no effects in the substantia nigra, globus pallidus or hippocampus. Aroclor 1260 concentrations ranged from 18 to 28 ppm with the highest levels found in the hippocampus. Of the congeners that made up more than 5% of the total residue in brain, all were hexa- and heptachlorinated di-ortho-substituted congeners. There were no discernible differences in congener make-up between brain regions. We conclude that: (1) ortho-substituted non-planar congeners are responsible for the observed changes in neurochemical function; (2) both Aroclor 1016 and Aroclor 1260 decrease dopamine concentrations by similar mechanisms; and (3) based on differences in brain concentrations of Aroclor 1260 congeners compared to Aroclor 1016 congeners, lightly-chlorinated congeners are more effective in reducing central dopamine concentrations than are the more highly chlorinated congeners.

Validity of the Orientation Log, relative to the Galveston Orientation and Amnesia Test

OBJECTIVE

To establish the validity of the Orientation Log (O-Log) by comparison with the Galveston Orientation and Amnesia Test (GOAT).

DESIGN

Correlation of daily measures of orientation.

SETTING

Acute rehabilitation hospital.

SUBJECTS

Sixty-eight inpatients receiving rehabilitation following traumatic brain injury (TBI).

PRIMARY MEASURES

The O-Log and GOAT.

RESULTS

There was a significant correlation between the GOAT and O-Log (r = .901, P<.001). A cutoff of 25 on the O-Log was found to be comparable with the 75 cutoff on the GOAT. The scales were equivalent in measuring duration of posttraumatic amnesia.

CONCLUSIONS

The O-Log is a valid measure of orientation for people with TBI and offers some advantages in administration over the GOAT.

High friction from a stiff polymer using microfiber arrays

High dry friction requires intimate contact between two surfaces and is generally obtained using soft materials with an elastic modulus less than 10 MPa. We demonstrate that high-friction properties similar to rubberlike materials can also be obtained using microfiber arrays constructed from a stiff thermoplastic (polypropylene, 1 GPa). The fiber arrays have a smaller true area of contact than a rubberlike material, but polypropylene's higher interfacial shear strength provides an effective friction coefficient of greater than 5 at normal loads of 8 kPa. At the pressures tested, the fiber arrays showed more than an order of magnitude increase in shear resistance compared to the bulk material. Unlike softer materials, vertical fiber arrays of stiff polymer demonstrate no measurable adhesion on smooth surfaces due to high tensile stiffness.

Polychlorinated biphenyls produce regional alterations of dopamine metabolism in rat brain

Adult male rats were gavaged with a mixture of polychlorinated biphenyls (PCBs; Aroclors 1254 and 1260) at either 500 or 1000 mg/kg body weight. Concentrations of dopamine (DA) and its major metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), were determined in caudate nucleus and lateral olfactory tract on postgavage Days 1, 3, 7 and 14. DA and DOPAC concentrations in caudate decreased after exposure to PCBs, as did HVA/DA ratios. DA concentrations in the lateral olfactory tract were unaffected, although DOPAC/DA ratios decreased. These results demonstrate that the mature mammalian nervous system is sensitive to a brief exposure to PCBs and that regional differences exist in the neurochemical sequelae of exposure to PCBs.

Decreases in dopamine concentrations in adult, non-human primate brain persist following removal from polychlorinated biphenyls

Adult male non-human primates, Macaca nemestrina, were orally exposed for 20 weeks to 3.2 mg/kg per day of either Aroclor 1016 or Aroclor 1260 made up in corn oil. Following cessation of exposure, the animals were observed for either an additional 24 or 44 weeks. After killing, regional brain concentrations of biogenic amines and polychlorinated biphenyls were determined by high-performance liquid chromatography (HPLC) and gas chromatography (GC), respectively. Brain dopamine (DA) concentrations were significantly decreased, compared to controls, in all polychlorinated biphenyl-exposed animals. Most importantly, in spite of significant decreases in brain polychlorinated biphenyl concentrations observed following removal from exposure (an average decline of 60%), there was no statistically discernible relationship of the changes in brain DA concentrations to either time following removal from polychlorinated biphenyls or brain polychlorinated biphenyl concentrations. These findings demonstrate that sub-chronic exposure of the adult non-human primate to polychlorinated biphenyls results in long-lasting changes in brain DA concentrations.

Cognitive and functional recovery at 6 and 12 months post-TBI

Outcome studies examining recovery from traumatic brain injury (TBI) often fail to provide a clear understanding of the time course of cognitive, emotional, and behavioural recovery. The present study represents an effort to prospectively study individuals with TBI at fixed intervals, specifically 6 and 12 months post-injury with a window of +/- 1 month. Seventy-two individuals with new-onset TBI underwent neuropsychological evaluation and clinical interview at 6 and 12 months post-injury. Results revealed significant improvements in cognitive abilities, including memory, processing speed, language abilities, and constructional skills. There were significant gains in community integration and involvement in productive activities, but limitations in driving activities remained. Although individuals with mild-moderate TBI performed better than individuals with severe TBI, both groups demonstrated equivalent rates of recovery across domains. The results of this study provide important information regarding the time course of TBI recovery.

Transbronchial biopsy without fluoroscopy. A seven-year perspective

The use of fluoroscopic guidance for transbronchial biopsy (TBB) during flexible fiberoptic bronchoscopic examination has been controversial. Patient records and bronchoscopy reports for 112 transbronchial biopsies performed with fluoroscopy over a seven-year period were reviewed and compared with those of 135 transbronchial biopsies performed without fluoroscopy over the same interval. Complication rates with regard to pneumothorax, fever, and hemorrhage were compared, as were yield data for neoplasm, sarcoidosis, and other miscellaneous pulmonary diagnoses. Complication rates were low in both groups and not statistically different; yield data were likewise comparable, particularly in diffuse neoplasm and sarcoidosis. This report suggests that TBB without fluoroscopy (in the basilar segments) is safe and that diagnostic yield, particularly in sarcoidosis and diffuse neoplasm, is good.

Ethylene glycol toxicity: the role of serum glycolic acid in hemodialysis

OBJECTIVE

To correlate serum glycolic acid levels with clinical severity and outcome in ethylene glycol poisoning and to determine if glycolic acid levels are predictive of renal failure and the need for hemodialysis.

METHODS

We measured serum ethylene glycol and glycolic acid levels by gas chromatography/mass spectrometry for 41 admissions (39 patients) for ethylene glycol ingestion and performed retrospective chart reviews.

RESULTS

Eight patients died, all of whom developed acute renal failure. Of the survivors, 15 also developed acute renal failure, whereas 18 did not. Of those with normal renal function, 8 had glycolic acid levels below detection limits (< 0.13 mmol/L) despite ethylene glycol levels as high as 710 mg/dL; 7 of these patients coingested ethanol. Pertinent initial laboratory data for each group are as follows (mean; range): Deceased: pH 6.99 (6.82-7.22); bicarbonate, 4.8 mmol/L (2-9); anion gap, 28.6 mmol/L (24-40); glycolic acid, 23.5 mmol/L (13.8-38.0); ethylene glycol, 136.5 mg/dL (6-272). Survived/acute renal failure: pH 7.07 (6.75-7.32); bicarbonate, 5.6 mmol/L (1-12); anion gap, 28.7 mmol/L (18-41); glycolic acid, 20.2 mmol/L (10.0-30.0); ethylene glycol, 238.8 mg/dL (12-810). No acute renal failure with glycolic acid > 1.0 mmol/L: pH 7.29 (7.12-7.46); bicarbonate, 14.7 mmol/L (4-23); anion gap, 16.5 mmol/L (10-26); glycolic acid, 6.8 mmol/L (2.6-17.0); ethylene glycol, 269.1 mg/dL (6-675). No acute renal failure with glycolic acid < 1.0 mmol/L: pH 7.41 (7.38-7.47); bicarbonate, 23.4 mmol/L (17-25); anion gap, 11.8 mmol/L (8-18); glycolic acid, 0.1 mmol/L (0-0.66); ethylene glycol, 211 mg/dL (8-710). The mean time postingestion to admission generally correlated with severity as follows: deceased, > or = 10.4 h; survived/acute renal failure, > or = 9.9 h; no acute renal failure with glycolic acid > 1.0 mmol/L, > or = 6.2 h; no acute renal failure with glycolic acid < 1.0 mmol/L, > or = 3.7 h. Hematuria was more prevalent than oxaluria (86% and 41%, respectively), but neither was individually predictive of acute renal failure. Good correlations were found between glycolic acid levels and anion gap (r2 = 0.7724), pH (r2 = 0.7921), and bicarbonate (r2 = 0.6579); poor correlations (r2 < 0.0023) occurred between ethylene glycol levels and glycolic acid, pH, anion gap, and bicarbonate. Measured ethylene glycol values were highly correlated with ethylene glycol values calculated from the osmolal gap (r2 = 0.9339), but the latter overestimates the true value by about 7%, on average. An initial glycolic acid level > or = 10 mmol/L predicts acute renal failure with a sensitivity of 100%, a specificity of 94.4%, and an efficiency of 97.6%. Ethylene glycol levels are not predictive of acute renal failure or central nervous system manifestations of toxicity. If only ethylene glycol values are available (measured or calculated), an initial anion gap > 20 mmol/L is 95.6% sensitive and 94.4% specific for acute renal failure when ethylene glycol is present. Likewise, initial pH < 7.30 is 100% sensitive and 88.5% specific for acute renal failure.

CONCLUSION

We propose glycolic acid > 8 mmol/L as a criterion for the initiation of hemodialysis in ethylene glycol ingestion. Patients with glycolic acid < 8 mmol/L probably do not need dialysis, regardless of the ethylene glycol concentration, when metabolism of ethylene glycol is therapeutically inhibited. In the absence of glycolic acid values, an anion gap > 20 mmol/L or pH < 7.30 predicts acute renal failure.

Fish consumption and breast milk PCB concentrations among Mohawk women at Akwesasne

A study was conducted to determine the relation between the consumption of contaminated local fish and concentrations of total polychlorinated biphenyls (PCBs) and 68 PCB congeners in the milk of nursing Mohawk women residing near three hazardous waste sites. From 1986 to 1992, 97 Mohawk women were interviewed and donated at least 50 ml of breast milk. The comparison population consisted of 154 Caucasians. After adjustment for potential confounders, Mohawk mothers who gave birth in 1986-1989 had a geometric mean milk total PCB concentration of 0.602 ppm (fat basis) compared with 0.375 ppm for the control group (p = 0.009). These Mohawk women also had significantly higher geometric mean concentrations of nine congeners. Beginning in 1990, however, there were no significant differences between the Mohawk women and the comparison group. Estimated cumulative lifetime exposure from local fish consumption was significantly related to milk total PCB and to three congeners only among those Mohawks who gave birth from 1986 to 1989. The reduction in breast milk PCB concentrations parallels a corresponding decrease in local fish consumption and may be the result of the advisories that have been issued over the past decade recommending against the consumption of local fish by pregnant and nursing Mohawk women.

Mesh Generation—A Survey

This report discusses pertinent schemes in finite element mesh generation. It is divided into two parts; node point generation and element generation. Node generation consists of automatically determining the coordinates of the finite element nodes. The basic node generation methods reviewed are straight line interpolation, sides and parts, electro-mechanical devices, simplified finite difference, the equipotential method and the natural coordinate system method. Element generation consists of automatically connecting the nodes to form elements. These methods are simple increments, sides and parts pseudo I-J transformation, fully surrounded point, and I-J transformation.

Human health and chemical mixtures: an overview

Unlike laboratory animals, people are rarely exposed to a single hazardous chemical. However, most of the information documenting adverse human health effects from environmental and occupational contaminants has come from studies focused on exposure to single chemicals, and there is little information available on how two or more contaminants affect humans. Most information on the effects of mixtures comes from animal systems and limited investigations of isolated human cells in culture, even though the study of mixtures in such systems has also been neglected. Two or more compounds may show additive, antagonistic, or synergistic interactions or may act on totally different systems and thus not interact. Furthermore, even a single chemical may have multiple effects and affect more than one organ system. Effects may vary with age, and metabolites may have totally different actions from the parent compound. This paper will review the variety of health effects in humans that may result from environmental contaminants and discuss how such contaminants may interact with each other. We will also present examples on how different contaminants interact from toxicologic studies of polychlorinated biphenyls performed as part of our Albany, New York, Superfund Basic Research Program project.

PCBs reduce long-term potentiation in the CA1 region of rat hippocampus

Prenatal exposure to polychlorinated biphenyls (PCBs) has been associated with a lower IQ in childhood. We have examined the effects of acute exposure to PCB mixtures and two single congeners on synaptic transmission between Schaffer collaterals and CA1 neurons of the rat hippocampus as well as posttetanic potentiation (PTP), paired pulse facilitation (PPF), and long-term potentiation (LTP). PTP and PPF represent transient increases in transmitter release immediately after stimulation, while LTP is a measure of long-term changes in synaptic plasticity that has been related to learning and memory. LTP, but neither PTP nor PPF, was reduced by Aroclor 1016 in a dose-dependent fashion at concentrations that had little effect on general synaptic transmission. The more highly chlorinated Aroclor 1254 at low concentrations specifically blocked LTP, but at higher concentrations also reduced synaptic transmission. The mono-ortho PCB congener 2,4,4'-trichlorobiphenyl and the coplanar congener 3,3',4,4'-tetrachlorobiphenyl also blocked LTP without effect on PTP or PPF. We conclude that PCBs selectively impair the process of LTP in CA1 neurons of the hippocampus.

Exercise dysfunction in patients seropositive for the human immunodeficiency virus

To confirm the presence of exercise dysfunction in patients seropositive for the human immunodeficiency virus (HIV), 32 such patients without AIDS were evaluated with cardiopulmonary exercise testing, pulmonary function testing, bronchoalveolar lavage, chest roentgenography, and gallium scanning. No evidence of pulmonary opportunistic infection was found. When compared to an otherwise similar group of HIV-seronegative controls, the patients exercised to a significantly lower workload (195 +/- 30 versus 227 +/- 31 W, p less than 0.001). The ventilatory anaerobic threshold (VAT) values were also significantly lower for the patients (49.2 +/- 13.0 versus 61.9 +/- 9.1% of maximum predicted VO2, p less than 0.001). Nine of the patients had VAT values less than the 95% confidence interval for the controls. This subgroup exercised to a significantly lower maximum VO2 (69.9 +/- 11.2 versus 95.9 +/- 17.5% of maximum predicted VO2, p less than 0.001) and workload (165 +/- 21 versus 227 +/- 31 W) when compared to the control group. These patients demonstrated a mild tachypnea throughout exercise relative to the controls and had a significant increase in the slope of the heart rate to VO2 relationship. These findings are most consistent with a limitation of oxygen delivery to exercising muscles, which may represent occult cardiac disease in this group.

Assessment of prenatal exposure to PCBs from maternal consumption of Great Lakes fish: an analysis of PCB pattern and concentration

The current study was designed to assess the pattern and concentration of prenatal PCB exposure in the newborns of women who consumed Great Lakes fish. We compared the pattern and concentration of umbilical cord blood PCBs of 145 women who reported never having consumed Great Lakes fish to 134 women who reported consuming at least 40 PCB-equivalent fish lbs of Great Lakes fish in their lifetime (Lonky et al., 1996). Although the average levels of total PCBs in cord blood were exceedingly low (approximately 1.0 ppb), the data clearly indicated that both the proportion (mol%) and the absolute concentration (ppb) of the most heavily chlorinated and persistent PCB homologues (homologues C17-C19) were markedly elevated in the cord blood of fish eaters. This effect grew markedly as a function of the total PCBs detected in the sample. Moreover, the concentration of the most heavily chlorinated PCB homologues was significantly dependent on how recently the fish were consumed relative to pregnancy. The order of highly chlorinated PCB concentration was consumed fish throughout pregnancy > consumed fish up until pregnancy > stopped consuming fish in 1984 > never consumed Lake Ontario fish. In contrast, PCB homologues of light (Cl1-Cl3) or moderate (Cl4-Cl6) chlorination were unrelated to fish consumption. Analysis of the relationship between the PCB homologues in cord blood and their homologues in breast milk provided further converging evidence of these findings. While PCB homologues of light (Cl1-Cl3) or moderate (Cl4-Cl6) chlorination did not correlate with their breast milk homologues, the most persistent and heavily chlorinated PCB homologues (Cl7-Cl9) were significantly and positively correlated with breast milk levels. These data indicate that the most heavily chlorinated PCBs provide valid and reliable exposure information in a lean medium such as cord blood. We conclude that maternal consumption of Great Lakes fish increases the risk of prenatal exposure to the most heavily chlorinated PCB homologues.

Hyperactivity and impulsiveness in rats fed diets supplemented with either Aroclor 1248 or PCB-contaminated St. Lawrence river fish

We examined whether exposure to polychlorinated biphenyls (PCBs) around puberty would produce hyperactivity and impulsiveness in adult Sprague-Dawley rats. Randomly assigned groups consumed food containing environmental concentrations of Aroclor 1248, PCB-contaminated St. Lawrence River carp, or corn oil (control). All received operant training to a final multiple (mult) 120-s, fixed interval (FI), 5-min extinction (EXT) schedule. Pressing rates of both exposed groups for drops of water averaged more than 1.5 times that of controls, especially toward the end of the 120-s interval. This overactivity included bursts with short (< or =0.5 s) interresponse times (IRTs), behavior characteristic of hyperactive boys and genetically hyperactive rats. The exposed groups also overreacted to the decreases in reinforcement density associated with transition to the final schedule. The results were interpreted in terms of the possible alterations in the animals' reinforcement mechanisms and the possible neurotoxic effects of PCB exposure.

Alcohol abuse in women seeking gynecologic care

In several retrospective studies, alcoholic women have reported menstrual problems significantly more often than nonalcoholic women. There is no information, however, comparing the prevalence of alcohol abuse in women who receive periodic gynecologic care and those who seek care for menstrual disorders such as the premenstrual syndromes. This question was studied in two private practice settings. Women seeking periodic care were obtained from a suburban, general gynecology practice. Women seeking treatment for premenstrual syndrome (PMS) were obtained from a practice that specialized in the care of PMS. Ninety-five patients with PMS and 147 patients seeking periodic care were screened with the CAGE questions--a mnemonic for attempts to Cut back on drinking, being Annoyed at criticism about drinking, feeling Guilty about drinking, and using alcohol as an Eye-opener. Women who gave affirmative responses to one or more of the CAGE questions were evaluated for the presence of alcohol abuse. In the women seeking periodic care, 33% were CAGE positive and 12% were alcohol abusers. In the PMS practice, 51% were CAGE positive and 21% were alcohol abusers. Alcohol abuse is a common problem in gynecologic practice. Women who seek medical care for PMS are at much greater risk to be alcohol abusers.