Congenital bullous syphilis in a newborn: A novel approach to diagnosis using immunohistochemical staining on a blister roof

We describe a rare presentation of congenital bullous syphilis in a premature neonate born with extensive skin desquamation. The newborn was noted to have diffuse erythema with widespread, superficial skin desquamation in addition to plantar bullae and erosions, and an absence of mucosal involvement. Immunohistochemical syphilis diagnostic staining was performed on a blister roof, highlighting a novel diagnostic approach for congenital bullous syphilis.

Insisting on the Healer's Art: The Implications of Required Participation in a Medical School Course on Values and Humanism

THEORY

Elective courses, by definition, allow medical students to self-select for participation in the class. In a small-group learning setting, students uninterested or not ready for a particular learning topic might change the educational experience ("poison the well") for those students most interested in the topic. It is not known how medical students required to take a course in humanism (that they otherwise would not have elected to take) might be impacted by the course or how their presence might affect students originally interested in the course.

HYPOTHESES

Medical students in a required course on humanism and values in medicine will have different experiences based on whether a particular student might have or not have elected to enroll in the course. Students uninterested in taking a course in humanism and values, but required to enroll, will limit the benefit of the course for those students originally interested in participating.

METHOD

In 2012, all 1st-year students at a U.S. medical school were required to take the Healer's Art, an elective on professional values and humanism offered at more than 90 other schools in the United States and internationally. Students completed pre/postcourse surveys assessing emotional exhaustion, work engagement, positive emotions, and cynicism. We analyzed differences between those who would have elected to take the course (Elective students) and those who would not have elected to take it (Required students).

RESULTS

Elective students did not differ from Required students in baseline demographic characteristics, emotional exhaustion, work engagement, or positive emotions. At baseline, Elective students did report feeling safer to talk openly, a greater sense of community, and higher levels of cynicism. Over time, there were no differences in course evaluations or outcomes between Elective and Required students.

CONCLUSIONS

Required students do not differ greatly from those who would have elected to take Healer's Art, and all students appear to have similar experiences in the course.

Three-class antiretroviral resistance in a patient with acute HIV-1 infection

Antiretroviral resistance in treatment-naïve patients with HIV-1 infection is on the rise in both resource-rich and resource-poor countries. We report a case of three-class primary antiretroviral resistance detected by a genotypic assay in a 19-year-old woman with acute HIV-1 infection. Her risk factor for HIV acquisition was unprotected sexual intercourse with a HIV-positive man. At diagnosis, her HIV-1 RNA level was 730,376 copies per milliliter, and 2 weeks later her CD4+ cell count was 465 cells/mm(3). The patient's antiretroviral therapy was chosen based on the genotype of the source patient. Subsequent analysis of our patient's virus revealed an identical genotype to that of the source patient. The patient tolerated therapy well and continues to be virologically suppressed after 1 year of therapy. Her current CD4+ cell count is 537 cells/mm(3) and HIV-1 RNA is less than 400 copies per milliliter. This case supports the current recommendations from several HIV therapy guidelines to perform resistance testing in patients with acute HIV-1 infection.

Clonidine and yohimbine in opioid-dependent humans responding under a naloxone novel-response discrimination procedure

Opioid-maintained volunteers were trained to distinguish between a low dose of the opioid antagonist naloxone (0.15 mg/70 kg, i.m.; i.e. Drug A) and placebo (i.e. Drug B), under an instructed novel-response drug discrimination procedure in which subjects identify the drug condition as 'A', 'B', or 'N' (neither A nor B - 'novel'). Once the discrimination was acquired, doses of naloxone, the alpha2-adrenergic antagonist yohimbine, the alpha2-adrenergic agonist clonidine, and the training dose of naloxone in combination with clonidine were tested. Naloxone and yohimbine each produced a dose-related increase and decrease in naloxone- and 'novel'-appropriate responding, respectively, with the naloxone stimulus partially generalizing to yohimbine. Clonidine produced primarily placebo-appropriate responding. Naloxone produced expected changes in self-reports, but effects of yohimbine and clonidine were unremarkable, and yohimbine was never identified as an opioid antagonist. Clonidine partially attenuated naloxone-occasioned responding in a non-dose-related manner, and attenuated some, but not all, naloxone-induced changes in self-report measures. Naloxone attenuated or enhanced several clonidine-induced changes in self-report and physiological measures. These findings indicate that adrenergic mechanisms are involved in the expression of opioid withdrawal, but the involvement is indirect.

Activity of pallidal and striatal tonically active neurons is correlated in mptp-treated monkeys but not in normal monkeys

The goal of this study is to assess the function of tonically active neurons (TANs) of the striatum and their malfunction in the parkinsonian state. We recorded multiple spike trains of striatal TANs and pallidal neurons, which are the main target of striatal projections. Recordings were performed in two vervet monkeys before and after the induction of tremulous parkinsonism by systemic injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP). We then calculated cross-correlograms between TANs and pallidal neurons to evaluate the interactions between them. In the normal monkeys, only 1.3% (2/152) of the cross-correlograms displayed significant peaks, and 8.6% (13/152) displayed significant oscillations. After MPTP treatment, 42.8% (83/194) of the cross-correlograms displayed significant peaks or troughs, or both, and 58.8% (114/194) displayed significant 3-19 Hz periodic oscillations. The frequency content of the coherent oscillations matched the frequency content of the activity of individual TANs, but was only weakly related to that of individual pallidal cells. These results confirm the notion that in the normal state neurons in the basal ganglia tend to fire independently, whereas in the parkinsonian state they exhibit synchronized oscillatory activity. The low level of correlated activity in the normal state demonstrates that TANs have only a slight effect on pallidal activity during execution of familiar behavior. The high level of oscillatory correlated activity in the parkinsonian state further suggests that coherent oscillations of the whole basal ganglia circuitry underlie the clinical features of Parkinson's disease.

Nicotine transdermal patch and atypical antipsychotic medications for smoking cessation in schizophrenia

OBJECTIVE

Schizophrenic patients have high rates of cigarette smoking. The authors compared the outcomes of two group psychotherapy programs for smoking cessation in patients with schizophrenia or schizoaffective disorder who were also treated with the nicotine transdermal patch and with either atypical or typical antipsychotic medications.

METHOD

Forty-five subjects were randomly assigned to 1) the group therapy program of the American Lung Association (N=17) or 2) a specialized group therapy program for smokers with schizophrenia (N=28) that emphasized motivational enhancement, relapse prevention, social skills training, and psychoeducation. All subjects participated in 10 weeks of treatment with the nicotine transdermal patch (21 mg/day) and 10 weekly group therapy sessions and continued to receive their prestudy atypical (N=18) or typical (N=27) antipsychotic medications. Outcome variables included treatment retention, rate of smoking abstinence, and expired-breath carbon monoxide level.

RESULTS

Smoking abstinence rates did not differ in the two group therapy programs. However, atypical antipsychotic agents, in combination with the nicotine transdermal patch, significantly enhanced the rate of smoking cessation (55.6% in the atypical agent group versus 22.2% in the typical group), which was reflected by a significant effect of atypical versus typical agents on carbon monoxide levels. Risperidone and olanzapine were associated with the highest quit rates.

CONCLUSIONS

The results suggest that 1) smoking cessation rates with the nicotine transdermal patch are modest in schizophrenia, 2) specialized group therapy for schizophrenic patients is not significantly different from American Lung Association group therapy in its effect on smoking cessation, and 3) atypical agents may be superior to typical agents in combination with the nicotine transdermal patch for smoking cessation in schizophrenia.

Desipramine in opioid-dependent cocaine abusers maintained on buprenorphine vs methadone

BACKGROUND

Cocaine abuse occurs in 40% to 60% of patients entering opioid maintenance treatment, and effective pharmacotherapies are needed for this combined dependence.

METHODS

This 13-week, randomized, double-blind, placebo-controlled trial evaluated the efficacy of desipramine hydrochloride (0 or 150 mg/d) plus buprenorphine hydrochloride (12 mg/d) or methadone hydrochloride (65 mg/d) in 180 opioid-dependent cocaine abusers (124 men, 56 women). Supervised urine samples were obtained thrice weekly, and self-reported cocaine and heroin use was reported once weekly. Desipramine plasma levels were determined at weeks 4 and 10.

RESULTS

In men, opioid abstinence was increased more rapidly over time when treated with methadone than with buprenorphine, whereas cocaine abstinence was increased more with buprenorphine than with methadone. In women, opioid abstinence was increased the least rapidly when treated with buprenorphine plus placebo, while cocaine abstinence was increased more rapidly over time when treated with methadone than with buprenorphine. Regardless of sex or opioid medication, desipramine increased opioid and cocaine abstinence more rapidly over time than placebo. Self-reported opioid use confirmed these findings. Desipramine plasma levels were higher in women than in men, particularly those on buprenorphine maintenance. Higher desipramine plasma levels were associated with greater opioid, but not cocaine, abstinence.

CONCLUSIONS

Desipramine may be a useful adjunctive medication in facilitating opioid and cocaine abstinence in opioid-maintained patients. The efficacy of opioid medications to treat opioid or cocaine dependence may differ by sex. These findings highlight the importance of including sex as a factor when examining treatment outcome in these types of trials.

Physiology of MPTP tremor

Rhesus and vervet monkeys respond differently to treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride neurotoxin (MPTP). Both species develop akinesia, rigidity, and severe postural instability. However, rhesus monkeys only develop infrequent, short episodes of high-frequency tremor, whereas vervet monkeys have many prolonged episodes of low-frequency tremor. After MPTP treatment, the spiking activity of many pallidal neurons became oscillatory and highly correlated. Oscillatory autocorrelation functions were dominated by lower frequencies, cross-correlograms by higher frequencies. The phase shift distribution of the oscillatory cross-correlograms of pallidal cells in MPTP-treated vervet monkey were clustered around 0 phase shift, unlike the oscillatory correlograms in the MPTP-treated rhesus monkey, which were widely distributed between 0 degrees and 180 degrees. Analysis of the instantaneous phase differences between tremors of two limbs in the MPTP monkeys and human parkinsonian patients showed short periods of tremor synchronization. We thus concluded that the rhesus and the vervet models of MPTP-induced parkinsonism may represent the tremulous and nontremulous variants of human parkinsonism. We suggest that the tremor phenomena of Parkinson's disease (PD) are related to the emergence of synchronous neuronal oscillations in the basal ganglia. Finally, the oscillating neuronal assemblies in the pallidum of tremulous parkinsonian primates are more stable (in time and in space) than those of parkinsonian primates without overt tremor.

Gender stereotyping for sociability, dominance, character, and mental health: a meta-analysis of findings from the bogus stranger paradigm

A meta-analysis was conducted of target gender effects on trait attributions from 18 bogus stranger studies that had manipulated target gender and target physical attractiveness. Collapsed over sex of perceivers, female targets were seen as more sociable, happier, and possessing greater character than male targets. However, these effects were small and were often moderated by the perceivers' sex. Male perceivers viewed female targets as more sociable and happier than male targets, whereas female perceivers viewed male targets as more dominant than female targets. There was no moderation of the gender effect on attributions of character, as both sexes viewed females more favorably than males and the effect size was very small for perceivers of both sexes.

Physiological aspects of information processing in the basal ganglia of normal and parkinsonian primates

There are two views as to the character of basal-ganglia processing - processing by segregated parallel circuits or by information sharing. To distinguish between these views, we studied the simultaneous activity of neurons in the output stage of the basal ganglia with cross-correlation techniques. The firing of neurons in the globus pallidus of normal monkeys is almost always uncorrelated. However, after dopamine depletion and induction of parkinsonism by treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), oscillatory activity appeared and the firing of many neurons became correlated. We conclude that the normal dopaminergic system supports segregation of the functional subcircuits of the basal ganglia, and that a breakdown of this independent processing is a hallmark of Parkinson's disease.

Protease inhibitor therapy in children with perinatally acquired HIV infection

OBJECTIVE

To review the short-term response and safety of protease inhibitor therapy in HIV-infected children.

DESIGN

Retrospective chart review of open-label protease inhibitor-containing combination therapy.

SETTING

Two urban pediatric HIV centers.

PATIENTS

Twenty-eight HIV-infected children were prescribed 30 protease inhibitor-containing antiretroviral therapy combinations. The median age at initiation of protease inhibitor antiretroviral therapy was 79 months. Patients had been on previous antiretroviral therapy for a mean of 45.5 months.

RESULTS

Of the 28 children who completed at least 1 month of therapy, 26 experienced marked virologic and immunologic improvement (mean maximal decrease in viral load 1.90 log10 copies/ml; SD, 0.8; mean maximal rise in CD4+ lymphocytes of 279 x 10(6)/l; SD, 300 x 10(6)/l). Eleven patients achieved a viral nadir of < 400 copies/ml, and seven sustained this level of viral suppression for a mean of 6 months. Indinavir use was associated with a high incidence of renal side-effects, including two patients who developed interstitial nephritis. Two patients on ritonavir experienced a significant elevation of liver enzymes.

CONCLUSIONS

Protease inhibitor therapy was associated with substantial short-term virologic and immunologic improvement in this primarily heavily pretreated cohort, with 25% maintaining a viral load of < 400 copies/ml after 6 months of therapy. There was a significant rate of adverse events. Pharmacokinetic and safety data are needed to guide aggressive antiretroviral therapy in HIV-infected children, and further treatment options are required for those failing or intolerant to the available protease inhibitors.

Neuronal synchronization of tonically active neurons in the striatum of normal and parkinsonian primates

1. Previous studies indicate that tonically active neurons (TANs) are the cholinergic interneurons of the striatum and predict that their activity is synchronized. To test whether TANs do fire synchronously, and whether dopamine depletion affects their synchronization, we recorded the simultaneous activity of several TANs in the putamens of two vervet monkeys before and after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment. 2. Cross-correlation analysis revealed that most pairs of TANS (33 of 54; 61.1%) fire synchronously at +/- 60-ms delay. Correlated activity was more common between neurons with characteristic response to reward (17 of 19 pairs; 89.5%). 3. Cross-correlation study of 24 triplets of TANS showed synchronization of spiking activity of all 3 TANS in only 29.2% of cases (7 of 24 triplets). Correlated activity of two of three possible pairs was found in 25% of the cases. 4. After MPTP treatment and the development of parkinsonian symptoms, most TANS' auto- and cross-correlograms (22 of 28 units; 78.6%; and 23 of 28 pairs; 82.1%) became oscillatory. The number of correlated pairs was slightly increased (24 of 28; 85.7%). The strength of the synchronization was not significantly different from the normal values. 5. These findings support the notion that TANs function as distributed, partially overlapping synchronized networks. However, a normal dopaminergic system is not essential for synchronization of TANs; on the contrary, dopaminergic activity may even have a desynchronizing effect on the basal ganglia's system.

Generalizability of the type A/type B distinction across different psychoactive substances

Previous research using cluster analysis has found that abusers of both alcohol and cocaine can be categorized into more severe (Type B) and less severe (Type A) subgroups. This article sought to replicate and extend these findings in a sample of 521 inpatients, outpatients, and nontreatment-seeking abusers of alcohol, cocaine, marijuana, and opiates. Cluster analyses of subsamples that met the DSM-IV criteria for dependence or abuse for alcohol, cocaine, marijuana, and opiates found that the Type A/Type B distinction was largely generalizable across drugs. Type As--who consistently accounted for about 60% of all substance abuse and about half of abusers in treatment-scored lower than Type Bs on a variety of substance abuse and psychiatric measures that were administered both at intake and at a 6-month follow-up.

Construct validity of the dependence syndrome as measured by DSM-IV for different psychoactive substances

The Diagnosis of Drug Dependence in the Official Psychiatric Nomenclatures (DSM-III-R, DSM-IV, and ICD 10) are based on the Drug Dependence Syndrome construct. Although the validity and utility of the dependence syndrome has been widely documented for alcohol, the generalizability of the dependence syndrome to other psychoactive substances is still not clear. Thus, this article examines the construct validity of the drug dependence syndrome, as measured by diagnostic criteria for DSM-IV, using both internal consistency analyses and confirmatory factor analyses. Data were obtained from non-mutually exclusive groups of abusers for five drugs (alcohol, cocaine, marijuana, opioids, sedatives, stimulants) drawn from a pool of 521 subjects obtained from drug treatment, general psychiatric and community samples. As predicted by the theory, drug dependence items were found to be unidimensional and factorially distinct from measures of the consequences of substance abuse (e.g. legal problems) for all drug groups. Moreover, the drug dependence items yielded internally consistent scales that produced a distribution of scores reflecting a continuum from low to high severity of abuse for all drugs.

Neurons in the globus pallidus do not show correlated activity in the normal monkey, but phase-locked oscillations appear in the MPTP model of parkinsonism

1. To test the mode of functional connectivity in the basal ganglia circuitry, we studied the activity of simultaneously recorded neurons in the globus pallidus (GP) of a behaving rhesus monkey. The cross-correlograms of pairs of neurons in the GP were compared with those of neurons in the thalamus and frontal cortex and to the cross-correlograms of pallidal pairs after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment. 2. In contrast with cortical and thalamic neuronal activity, almost all pairs (n = 76/81 pairs; 93.8%, 1,629/1,651 histograms; 98.7%) of GP neurons in the normal monkey were not driven by a common input. 3. The monkey was systemically treated with MPTP until the appearance of parkinsonian signs and an intermittent 7- to 11-Hz action/postural tremor. After the MPTP treatment, many pallidal neurons (49/140; 35%) became oscillatory, and 19% (n = 31/162) of pallidal pairs had oscillatory cross-correlograms. 4. These results support the model of parallel processing in the basal ganglia of normal monkeys and suggest a breakdown of the independent activity in the parkinsonian state.

Construct validity of the abuse-dependence distinction as measured by DSM-IV criteria for different psychoactive substances

This article used the diagnostic criteria of the Diagnostic and Statistical Manual-Fourth Edition (DSM-IV) to compare the validity of a qualitative and a quantitative model of the abuse-dependence distinction for different psychoactive substances in samples of drug users drawn from drug treatment inpatients, general psychiatric patients, and the community. The hypothesis that DSM-IV abuse criteria differ from dependence criteria in kind rather than degree (a qualitative model) was only occasionally supported by confirmatory factor analyses of DSM-IV diagnostic criteria, by patterns of correlations of the two kinds of criteria with Addiction Severity Score (ASI) composites and measures of frequency of substance abuse, and by concurrent/prognostic validity analyses. However, the findings were consistent with a quantitative model of the abuse-dependence distinction that posits that abuse is a mild form of dependence. Whether abuse and dependence categories of users were established from separate DSM-IV criteria for abuse and dependence or from scores from a severity-of-dependence scale based on the pooled DSM-IV dependence and abuse criteria, abusers generally used drugs less than users in the dependence category and reported less problems associated with substance abuse on the ASI.

Gender differences in personality: a meta-analysis

Four meta-analyses were conducted to examine gender differences in personality in the literature (1958-1992) and in normative data for well-known personality inventories (1940-1992). Males were found to be more assertive and had slightly higher self-esteem than females. Females were higher than males in extraversion, anxiety, trust, and, especially, tender-mindedness (e.g., nurturance). There were no noteworthy sex differences in social anxiety, impulsiveness, activity, ideas (e.g., reflectiveness), locus of control, and orderliness. Gender differences in personality traits were generally constant across ages, years of data collection, educational levels, and nations.

A model integrating mental health and primary care services for families with HIV

The need to integrate mental health and primary care service delivery for individuals and families living with human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) has been well documented. Accessibility, flexibility, and cultural specificity are qualities necessary, but generally lacking, in existing models of integrated care. In this paper, NOAH (No One Alone with HIV), an innovative, hospital-based program of family-focused HIV mental health services, will be described. NOAH is designed to meet the needs of primary care providers, allied professionals/paraprofessionals, and the diversity of inner-city patients they serve. Central to the model are population-specific "family health facilitators," who collaborate with providers by offering mental health interventions at one or more levels along a continuum of service intensity. Whenever possible, primary care team members are empowered to manage mental health problems directly. When more intensive services are required, responsibility for direct intervention transfers to the family health facilitator. With the locus of inner-city HIV primary care shifting from hospitals to neighborhood health centers, this hospital-based program has been extended into the community to support the early integration of mental health and primary care services at the community level.

Gender differences in mate selection preferences: a test of the parental investment model

Evolutionary-related hypotheses about gender differences in mate selection preferences were derived from Triver's parental investment model, which contends that women are more likely than men to seek a mate who possesses nonphysical characteristics that maximize the survival or reproductive prospects of their offspring, and were examined in a meta-analysis of mate selection research (questionnaire studies, analyses of personal advertisements). As predicted, women accorded more weight than men to socioeconomic status, ambitiousness, character, and intelligence, and the largest gender differences were observed for cues to resource acquisition (status, ambitiousness). Also as predicted, gender differences were not found in preferences for characteristics unrelated to progeny survival (sense of humor, "personality"). Where valid comparisons could be made, the findings were generally invariant across generations, cultures, and research paradigms.

On the internal consistency of the beta II

The internal consistency of the Beta II, a recent revision of the Revised Beta Examination, was examined for a sample of alcoholic inpatients (81 men, 19 women) of low ability and socioeconomic status. They were aged 19 to 65 yr. ( M = 36.6, SD = 9.2) and had been admitted for treatment at a state agency for rehabilitation for alcoholism. Pearson inter-correlations were reported as well as the correlations between subtests and the sums of scaled scores. The median subtest intercorrelation was .51 and the median subtest-sum of scaled scores correlation was .76. Although these coefficients were smaller than those reported for the previous edition of the Beta, they compared favorably with results obtained for the recent revision of the Performance scale of the WAIS.

Validity of the Revised Beta Examination and a short-form Beta for hospitalized alcoholics

Although the Revised Beta Examination, a nonverbal measure of general intelligence, is one of the few group tests extensively validated for psychiatric patients in state hospitals, it has not been determined whether the instrument is useful for discriminating among alcoholic inpatients in state facilities. The Beta was administered to 494 detoxified alcoholics (471 men, 23 women), aged 20 to 60 yr. ( M = 3.99, SD = 10.1) and hospitalized in a state rehabilitation agency. They were grouped by prior occupational status and educational attainment. Means of the Beta Weighted Scores differed significantly among the groups on both criteria whereas the mean IQs differed only for the educational classification. Also reported was the development of a two-subtest short-form Beta based on the Digit Symbol and Picture Completion subtests. The short-form scores differentiated the groups about as well as the Weighted Scores.

Extracting maximum validity from the WAIS

Recent research (Feingold, 1982) on the incremental validity of the WAIS has found that the Vocabulary and Information subtests are each as valid as the Full Scale IQ. The present WAIS review demonstrated that weighting subtests that differ in validity equally in the computation of the IQ is responsible for reducing potential validity. Two main conclusions emerged from these data. One, Vocabulary and Information in concert yield a measure that has greater validity than either subtest by itself. Two, the addition of a third test in a stepwise multiple regression in which Vocabulary and Information already have been added will not result in a consistent increase in validity. These findings must be considered tentative, but can serve as a guide for devising research designs to validate the recent revision of the WAIS (WAIS-R).

Differences between employed and unemployed alcoholic inpatients in trouble for drinking and denial

The Trouble-Due-to-Drinking scale and the Denial scale of the MMPI were administered to two groups of inpatients of low socioeconomic status, an employed group (27 men, 3 women) and an unemployed one (44 men, 12 women), at a state alcoholism facility in an inner city catchment area. The former were significantly older than the latter; Ms = 40.4 and 35.5 yr., respectively. The Trouble scale correctly identified 98% of the unemployed group but only 83% of the employed group. The unemployed scored significantly higher on MMPI Denial and significantly lower on the Trouble scale than the unemployed. The Pearson r between scores on the two measures was negative and significant for the combined sample and for the unemployed as well, whereas r for the unemployed was negative but nonsignificant. It was concluded that the unemployed group was less given to the use of denial and had encountered more alcohol-related problems than the employed group.

Suxamethonium infusion rate and observed fasciculations. A dose-response study

Suxamethonium chloride (Sch) was administered i.v. to 36 adult males at six rates: 0.25 mg s-1 to 20 mg s-1. The infusion was discontinued either when there was no muscular response to tetanic stimulation of the ulnar nerve or when Sch 120 mg was exceeded. Six additional patients received a 30-mg i.v. bolus dose. Fasciculations in six areas of the body were scored from 0 to 3 and summated as a total fasciculation score. The times to first fasciculation, twitch suppression and tetanus suppression were inversely related to the infusion rates. Fasciculations in the six areas and the total fasciculation score were related directly to the rate of infusion. Total fasciculation scores in the 30-mg bolus group and the 5-mg s-1 and 20-mg s-1 infusion groups were not significantly different.

Crystalloid hemodilution, hypothermia, and halothane blood solubility during cardiopulmonary bypass

Sequential determinations of halothane blood solubility were determined in 8 patients undergoing cardiac surgical procedures with cardiopulmonary bypass (CPB), hypothermia, and crystalloid hemodilution. The mean temperature-corrected blood/gas partition coefficient (B/G) at the end of surgery (2.4) was lower than preceding induction (2.7). The greatest mean B/G (2.9) occurred after induction of anesthesia. The halothane B/G did not increase significantly at the inception of CPB but decreased from a mean 2.7 to 1.6 as the patients were rewarmed. The maximum range of B/G for a single patient was 1.4 to 3.1. For halothane, the increased blood solubility due to hypothermia was initially antagonized by the crystalloid hemodilution. This antagonism would also be anticipated for methoxyflurane, enflurane, and isoflurane. For N2O and diethyl ether, the increased blood solubility due to hypothermia would be unopposed by simultaneous crystalloid hemodilution.

Response time of the Narkotest anesthetic gas monitor

Response time (RT) of the Narkotest anesthetic gas monitor was measured for 7 inhalation anesthetics, using a 5 L/min fresh gas flow (FGF). Time to 63 percent of maximum response (RT63) and to 95 percent of maximum response (RT95) was directly related to rubber/gas and oil/gas partition coefficients. RT95 ranged from 7 seconds for N2O to 843 seconds for methoxyflurane. RT measured at 0.5 L/min FGF was markedly prolonged over RT at 5 L/min. When the Narkotest was placed on the expiratory limbs of circle-absorber breathing circuits, the difference between the calibrated Narkotest reading (Fn) and the mixed expired circuit concentration (Fc) was shown to depend on the rate of increase of the circuit concentration.

The pharmacokinetics of metabolism of inhalation anaesthetics. A simulation study

The non-steady state metabolism of inhalation anaesthetics during anaesthesia and recovery was simulated with a linear and non-linear whole body compartmental model. These two models were studied for nine anaesthetics during 1-MAC anaesthesias lasting 1, 4 and 8 h and recovery from 5 to 10 days. Both models demonstrated significant metabolism for several days following anaesthesia. For the linear model, both the percentage and the molar quantity of anaesthetic metabolized increased with increased duration of anaesthesia, increased anaesthetic fat solubility and increased assumed rate of hepatic metabolism. For the non-linear model, the duration of anaesthesia had little effect on the percentage metabolized but demonstrated increased molar quantities of anaesthetic metabolized with increased duration of anaesthesia and increased fat solubility. The agreement between the results obtained from the non-linear model and experimental data in the literature suggests that many inhalation anaesthetics belong to a class of xenobiotics whose biotransformation is limited by the same or similar non-linear rate-limiting step(s). A difference in the quantities of anaesthetic metabolized would be a direct consequence of the tissue solubilities of the anaesthetic.

A latex bag tonometer for determining the anaesthetic blood/gas partition coefficient

Many techniques for measurement of the tissue/gas partition coefficient are valid. Each has specific advantages and shortcomings. All the methods require suitable analytic equipment and means for controlling temperature. The disadvantages of a particular technique, the ability to cope with them and the availability of the necessary apparatus are the determining factors in choosing the best method. The latex bag tonometer has a precision and ease which compares favourably with previously described techniques for measuring anaesthetic blood/gas partition coefficients. The technique was successfully used to show the effect of in vivo haemodilution on the halothane blood/gas partition coefficient.

Analysis of tasks and human factors in anesthesia for coronary-artery bypass

A comprehensive task analysis of the anesthetist's activities during coronary-artery bypass procedures was carried out using time-lapse cinematography. This film was analyzed frame by frame to detect types of activities and the proportion of time spent on each. Link analysis was used to reveal recurring sequences of activities. Of the 9 activity categories, the anesthetist spends the greatest portion of time observing the patient and scanning the entire operative and monitoring field. Ten to 15% of the time is spent logging data on the anesthetic record. The challenge for the anesthetist is to optimize his performance, and those under his direction, in the face of the changing workload resulting from variations in patients' conditions. Use of an automated monitoring system that charts patient vital signs would allow the anesthetist to apportion this time among other tasks.

The effects of anesthetics on an in-vivo oxygen electrode

The IBC in-vivo oxygen electrode may be used during anesthesia. The possibility that three common inhalation anesthetics--halothane, enflurane, and methoxyflurane--might be reduced at the electrode, thereby changing the PO2 value, was tested. Enflurane and methoxyflurane do not affect the current produced at the electrode; halothane significantly increases PO2 readings at oxygen tensions below 105 torr. It is suggested that PaO2 readings below 105 torr be confirmed by the standard bench method.

A disposable in vivo oxygen electrode for the continuous measurement of arterial oxygen tension

An evaluation of the accuracy, perdision, and clinical safety of the IBC indwellling catheter electrode for the continuous monitoring of arterial oxygen tension during and after general anesthesia was made in a total of 62 patients. A comparison of the standard bench-type electrode (Radiometer) with the International Biophysics Corporation (IBC) electrode for the measurement of oxygen tension in tonometered blood also was performed. Three hundred and fifty comparisons in 51 patients were made of the indwelling electrode with a standard Radiometer unit and, while there was good correlation, there also was ome scatter. An additional small series of 44 comparisons in 11 patients was performed, the primary difference being that the electrode was maintained intr-arterially for approximately 1 day. In both in vivo studies there was excellent correlation but questionable precidion. Four IBC electrodes and eight Radiometer Pao2 electrodes in an additional study were compared at 11 different tonometered oxygen tensions in blood. The IBC electrodes measured oxyygen tension more accurately than did the Radiometer, and standard deviations were consistently smaller at all of 11 different oxygen tensions for the IBC unit. The authors believe that the poor precision within both in vivo studies might be due to the fact that the IBC probe, which was of unknown accuracy and precision, was compared to a standard device (the Radiometer) which in the in vitro investigation proved to be less accurate and less precise. No complications due to the insertion and maintance of this in vivo electrode were encountered. The authors suggest that the IBC method for measuring Pao2 continuously in vivo be considered as an alternative to intermittent gas analysis of oxygen tension.

Prevalence of hepatitis B antigen among army inductees

Eighteen thousand eight hundred and thirty-three consecutive army inductees from the Tel Aviv and Central Districts in Israel were examined for hepatitis B surface antigen (HBsAG) by the counterelectrophoresis technique. The overall prevalence was 1.36%, with a higher rate for males (1.84%) than for females (0.78%). The highest rates were observed among Jews of North African and Yemenite origin (4.14 and 3.97%, respectively) and the lowest rates was found among Jews of European origin (0.31%). There was a negative correlation between the prevalence of HBsAg and the level of education. If we assume that the prevalence of HBsAg in a population reflects the rate of infection with hepatitis B virus interacting with host factors, the results of this study support the hypothesis that infections with type B hepatitis in Israel occur mainly during childhood, more frequently among the lower socioeconomic classes, and with a predilection of either the infection or of the chronic carrier state for males and certain ethnic groups.