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Biomedical subjects

D G Kirch

Publications and source records attributed to D G Kirch.

At least 19 recordsLinked to original sources

Measuring contributions to the clinical mission of medical schools and teaching hospitals.

This is the final report of a panel convened as part of the Association of American Medical College's (AAMC's) Mission-based Management Program to examine the use of metrics (i.e., measures) in assessing faculty and departmental contributions to the clinical mission. The authors begin by focusing on methods employed to estimate clinical effort and calculate a "clinical full-time equivalent," a prerequisite to comparing productivity among faculty members and departments. They then identify commonly used metrics, including relative-value units, total patient-care gross charges, total net patient fee-for-service revenue, total volume per CPT (current procedural terminologies) code by service category and number of patients per physician, discussing their advantages and disadvantages. These measures reflect the "twin pillars" of measurement criteria, those based on financial or revenue information, and those based on measured activity. In addition, the authors urge that the assessment of quality of care become more highly developed and integrated into an institution's measurement criteria. The authors acknowledge the various ways users of clinical metrics can develop standards against which to benchmark performance. They identify organizations that are sources of information about external national standards, acknowledge various factors that confound the interpretation of productivity data, and urge schools to identify and measure secondary service indicators to assist with interpretation and provide a fuller picture of performance. Finally, they discuss other, non-patient-care, activities that contribute to the clinical mission, information about which should be incorporated into the overall assessment. In summary, the authors encourage the use of clinical productivity metrics as an integral part of a comprehensive evaluation process based upon clearly articulated and agreed-upon goals and objectives. When carefully designed, these measurement systems can provide critical information that will enable institutional leaders to recognize and reward faculty and departmental performance in fulfillment of the clinical mission.

Efficiency, Organizational↗

MRI changes during water loading in patients with polydipsia and intermittent hyponatremia.

OBJECTIVE: Patients with polydipsia and intermittent hyponatremia have greater ventricle-brain ratios (VBRs) than matched patients without polydipsia and intermittent hyponatremia and normal subjects. Unlike previous studies, this study controlled for the impact of water loading when examining the volume of intracranial structures. METHOD: Under controlled conditions, eight male schizophrenic patients with polydipsia and intermittent hyponatremia were first assigned to either normal fluid intake or oral water loading and then the alternative condition the following day. Magnetic resonance imaging (MRI) volumetric measurements were made with the use of a standardized protocol. RESULTS: During water loading, total VBR and lateral ventricle volume significantly decreased by 13.1% and 12.6%, respectively. A strong association between change in serum sodium concentration and change in VBR was noted across conditions. CONCLUSIONS: These findings indicate that 1) water loading does not account for the diminished brain volume observed in patients with polydipsia and intermittent hyponatremia in previous studies, and 2) hyponatremia can significantly alter brain morphology on MRI.

Adult↗

Impact of minority physicians on health care.

BACKGROUND: There is concern that anti-affirmative-action measures will negate gains made ill educating underrepresented minority physicians and that this underrepresentation may have a negative impact on access to health care for these same underrepresented groups. METHODS: A review of the literature was completed to examine the relationship between opportunities for underrepresented minorities in medical education and the role of minority physicians in providing access to health care for underserved populations. The current number of minority physicians in the United States is discussed, and a historical perspective is provided regarding efforts to increase the numbers. RESULTS: The data consistently indicate that minority physicians provide a disproportionately greater share of health care to underserved groups. CONCLUSION: These findings reveal that there may be a significant negative impact on access to health care among poor, minority, and underserved populations as a result of judicial and legislative actions that curtail affirmative action programs in medical education.

Education, Medical↗

CSF IL-1 and IL-2 in medicated schizophrenic patients and normal volunteers.

It is clear that cytokines exert a variety of modulatory actions on the central nervous system. As part of our work exploring the relationship between immune activation and psychosis, we measured cerebrospinal fluid (CSF) IL-1 alpha and IL-2 levels in 60 medicated schizophrenic patients and in 21 normal volunteers using a competitive enzyme immunoassay. The two groups did not differ significantly in their mean cytokine levels: 1.01 (0.149) ng/ml (patients) vs. 1.28 (0.150) ng/ml (controls) for IL-1 alpha and 0.970 (0.038) ng/ml (patients) vs. 1.25 (0.086) ng/ml (controls) for IL-2. There was a significant positive correlation between CSF IL-1 alpha and IL-2 levels for all subjects (r = 0.50, n = 44, p = 0.0001).

Adult↗

The relationship between urine excretion and biogenic amines and their metabolites in cerebrospinal fluid of schizophrenic patients.

Concentrations of norepinephrine and metabolites of biogenic amines were measured in lumbar cerebrospinal fluid of 30 patients with chronic schizophrenia, nine of whom were polyuric. The mean level of norepinephrine was two-fold higher (p < or = 0.025) in polyuric patients than in patients whose excretion of urine was within the normal range. CSF levels of histamine's primary metabolite, tele-methylhistamine, an index of brain histaminergic activity, were positively correlated (p < 0.005) with daily urine volume. These results are consistent with the known influence of norepinephrine and histamine on fluid regulation and suggest that norepinephrine and histamine may be involved in psychogenic polydipsia-polyuria in schizophrenic patients.

3,4-Dihydroxyphenylacetic Acid↗

Diagnostic accuracy and confusability analyses: an application to the Diagnostic Interview for Genetic Studies.

The dominant, contemporary paradigm for developing and refining diagnoses relies heavily on assessing reliability with kappa coefficients and virtually ignores a core component of psychometric practice: the theory of latent structures. This article describes a psychometric approach to psychiatric nosology that emphasizes the diagnostic accuracy and confusability of diagnostic categories. We apply these methods to the Diagnostic Interview for Genetic Studies (DIGS), a structured psychiatric interview designed by the NIMH Genetics Initiative for genetic studies of schizophrenia and bipolar disorder. Our results show that sensitivity and specificity were excellent for both DSM-III-R and RDC diagnoses of major depression, bipolar disorder, and schizophrenia. In contrast, diagnostic accuracy was substantially lower for subtypes of schizoaffective disorder-especially for the DSM-III-R definitions. Both the bipolar and depressed subtypes of DSM-III-R schizoaffective disorder had excellent specificity but poor sensitivity. The RDC definitions also had excellent specificity but were more sensitive than the DSM-III-R schizoaffective diagnoses. The source of low sensitivity for schizoaffective subtypes differed for the two diagnostic systems. For RDC criteria, the schizoaffective subtypes were frequently confused with one another; they were less frequently confused with other diagnoses. In contrast, the DSM-III-R subtypes were often confused with schizophrenia, but not with each other.

Bipolar Disorder↗

pros-Methylimidazoleacetic acid in cerebrospinal fluid of patients with chronic schizophrenia: relationships to ratings of symptoms, ventricular brain ratios, and rates of urine excretion.

Concentrations of pros-methylimidazoleacetic acid (p-MIAA) were measured in cerebrospinal fluid of 30 patients with chronic schizophrenia. Levels of p-MIAA correlated negatively with mean scores of the Psychiatric Symptom Assessment Scale for positive symptoms (r = -0.48), but not negative symptoms, and with ventricular brain ratios (r = -0.48). Patients with abnormal ventricular enlargements had much lower concentrations of p-MIAA than those with normal ventricles. These results suggest that processes that reduce accumulation of p-MIAA in CSF may be associated with increased severity of symptoms among patients with chronic schizophrenia.

Adult↗

Depression and smoking initiation among US Latinos.

We assessed the relationship between depression and smoking initiation among people of Mexican, Puerto Rican and Cuban ancestry residing in specific geographic areas of the United States. Survey data were examined to calculate incidence of smoking initiation and prevalences and odds ratios for ever smoking by presence of depressed mood, a history of major depression or both conditions. Depressed mood, a history of major depression or both conditions were associated with smoking initiation risks during childhood, adolescence and young adulthood. These findings suggest that the relationship between depressive states and smoking initiation is established early in life. More definitive studies are needed to confirm these findings.

Adolescent↗

Histamine metabolites in cerebrospinal fluid of patients with chronic schizophrenia: their relationships to levels of other aminergic transmitters and ratings of symptoms.

Levels of the histamine metabolites, tele-methylhistamine (t-MH) and tele-methylimidazoleacetic acid (t-MIAA), and metabolites of other aminergic transmitters and of norepinephrine were measured in cerebrospinal fluid of 36 inpatients with chronic schizophrenia and eight controls. The mean t-MH level from controls was nearly identical to the levels seen previously in healthy volunteers. Compared with controls, the mean level of t-MH in the schizophrenic patients was 2.6-fold higher (p = 0.006); 21 of the patients had levels exceeding the range of controls. There was no significant difference (p > 0.05) in levels of other analytes, although the levels of t-MH correlated significantly with those of t-MIAA, homovanillic acid, 3,4-dihydroxyphenylacetic acid, norepinephrine, 3-methoxy-4-hydroxyphenylglycol and 5-hydroxyindoleacetic acid. The difference in levels of t-MH were not attributable to medication, since those taking (n = 10) or withdrawn from (n = 26) neuroleptic drugs had nearly the same mean levels of t-MH; each group had higher levels than controls (ANOVA: p < 0.05). Patients with or without tardive dyskinesia showed no significant differences in means of any analyte. Only levels of t-MH among those with schizophrenia correlated with positive symptom scores on the Psychiatric Symptom Assessment Scale (rs = 0.45, p < 0.02). The elevated levels of t-MH in cerebrospinal fluid, which represent histamine that was released and metabolized, suggest increased central histaminergic activity in patients with chronic schizophrenia.

Adult↗

Increased serum soluble interleukin-2 receptors in Caucasian and Korean schizophrenic patients.

Recent studies have identified immunologic abnormalities in some schizophrenic subjects. This experiment replicates previous findings that serum soluble interleukin-2 receptors (SIL-2Rs) are elevated in schizophrenic patients, and is the first study to describe this phenomenon in non-Caucasian patients. Despite differences between Korean and Caucasian schizophrenic patients in absolute serum SIL-2R levels, both groups were significantly elevated when compared with their respective ethnic control groups (477 +/- 171 U/ml versus 354 +/- 172 U/ml and 763 +/- 347 U/ml versus 567 +/- 231 U/ml, respectively). Neither age, gender, medication status, nor duration of illness correlated with SIL-2R levels. These findings are further evidence that immune activation is present, regardless of ethnic origin, in some schizophrenic patients.

Adult↗

Effect of chronic haloperidol treatment on dopamine-induced inositol phosphate formation in rat brain slices.

The effects of chronic haloperidol administration on the accumulation of inositol phosphates were examined in rat brain slices pre-labeled with [3H]myo-inositol and incubated with various dopaminergic drugs. Rats were treated with haloperidol-decanoate or its vehicle (sesame oil) for two, four or six weeks. Dopamine and the selective D1 agonist, SKF38393, induced a significant increase in lithium-dependent accumulation of [3H]inositol monophosphate (IP1) in the frontal cortex, hippocampus and striatum of vehicle-treated animals, while the selective D2 agonist quinpirole did not show any effect on IP1 accumulation. The actions of dopamine and SKF38393 were blocked by the D1 antagonist, SCH23390, but not by the D2 antagonist, spiperone, in all three brain regions. Haloperidol treatment did not affect basal phosphoinositide turnover in the three brain regions. Four or six weeks of haloperidol treatment significantly decreased dopamine-induced IP1 accumulation in the striatum (by 30% and 25%, respectively), but not in the frontal cortex and the hippocampus. Four weeks of treatment with haloperidol significantly decreased IP1 levels in the striatal slices when measured in the presence of quinpirole. However, the accumulation of IP1 measured in the presence of SKF38393 was not significantly altered after haloperidol treatment. The loss of dopamine-sensitive IP accumulation was not observed in the presence of spiperone after haloperidol treatment. The number, but not the affinity, of [3H]sulpiride binding sites in the striatum was significantly increased (by 34-46%) after chronic haloperidol treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗

A multidimensional approach to analysis of cerebrospinal fluid biogenic amines in schizophrenia: I. Comparisons with healthy control subjects and neuroleptic-treated/unmedicated pairs analyses.

Recent hypotheses and findings indicate that measurements of interactions between cerebrospinal fluid (CSF) biogenic amine systems, rather than measurement of CSF biogenic amine metabolites, better correlate with clinically important findings in schizophrenia. To test hypotheses, we used a recent technological advance in high performance liquid chromatography with electrochemical detection and combined it with multivariate statistical analyses to study biogenic amine concentrations in CSF in schizophrenia. This approach enabled the study of the interactions of several metabolites of each of the three major neurotransmitter pathways (dopaminergic, noradrenergic, and serotonergic) to test existing hypotheses regarding the neurobiochemical basis of schizophrenia. Twenty biogenic amines, their metabolites, and other compounds from 24 medication-free schizophrenic patients and 12 normal control subjects were simultaneously measured using a recently developed technique of gradient high performance liquid chromatography coupled with a 16-channel electrochemical array detector. After covariation for storage time, results of a stepwise discriminant function analysis comparing the control and patient groups identified tryptophan, tryptophol, and epinephrine as discriminating variables. Hotelling's paired T2 test from a subgroup of schizophrenic patients studied while they were and were not receiving neuroleptic treatment did not yield any significant differences between subgroups. A discussion of the findings and a comparison with previous studies of CSF biogenic amines in schizophrenia are presented.

Adult↗

A multidimensional approach to analysis of cerebrospinal fluid biogenic amines in schizophrenia: II. Correlations with psychopathology.

As part of a multidimensional study of cerebrospinal fluid biogenic amine metabolites in schizophrenia, the relationship between neurochemical measures and psychopathology assessed using the Psychiatric Symptom Assessment Scale (PSAS) was analyzed. In a group of 20 unmedicated patients, 3,4-dihydroxyphenylacetic acid (DOPAC) was a predictor of symptom severity in a stepwise multiple regression model. Values of 3-hydroxykynurenine and metanephrine in the unmedicated state predicted clinical response in a stepwise multiple regression model, as measured by improvement in PSAS mean item score following 6 weeks on a standard dose of neuroleptic. In a subgroup of 14 patients in whom both off- and on-medication concentrations of cerebrospinal fluid biogenic amines and metabolites were measured, change in 3-hydroxykynurenine predicted clinical outcome in a multiple regression model. These findings point toward the need to examine the role of the kynurenine pathway of tryptophan metabolism in the pathophysiology of schizophrenia.

Adult↗

Event-related potential abnormalities correlate with structural brain alterations and clinical features in patients with chronic schizophrenia.

Patients with schizophrenia appear to have abnormalities in both brain structures and information processing. Several recent reports have suggested that correlations exist between such measures. We examined the volume of several brain regions using magnetic resonance imaging (MRI), and also assessed both information processing, using brain event-related potentials (ERPs), and clinical symptomatology in sixteen medicated patients with schizophrenia. Subjects were tested using auditory and visual discrimination tasks. From the ERPs elicited by stimuli presented with relative probabilities of 0.1, the N100, N200, and P300 components were identified and measured. All subjects also had MRI scans that included 12 contiguous coronal sections, each 1 cm thick. From these scans, the following structures were identified and the volume or area quantified: third ventricle, lateral ventricles (partial), amygdala and hippocampus (one slice), partial brain volume (in one slice through the parietal lobe), and total prefrontal and temporal lobe gray and white matter in both cortical regions. Significant correlations were found between hippocampal area and the amplitude of the auditory and visual N200, and between the right hippocampus and the visual P300. Lower but significant correlations were seen between auditory P300 and measures of left temporal lobe structures. Auditory P300 amplitude correlated inversely with positive symptoms of schizophrenia. These preliminary results suggest that the ERP abnormalities in patients with schizophrenia are associated with temporal lobe pathology.

Adult↗

Cerebrospinal fluid oxytocin concentration in schizophrenic patients does not differ from control subjects and is not changed by neuroleptic medication.

Cerebrospinal fluid (CSF) oxytocin concentrations in 20 neuroleptic-treated schizophrenic patients, 31 neuroleptic-withdrawn schizophrenic patients, and 15 normal control subjects were compared. Neither within-subject comparisons of CSF oxytocin concentration measurements made during neuroleptic treatment and withdrawal (n = 11), nor comparison of the combined neuroleptic-withdrawn and neuroleptic-treated patient group (n = 40) with control subjects (n = 15) differed significantly, suggesting that CSF oxytocin concentration is not altered in schizophrenia.

Adult↗

Effects of water loading in schizophrenic patients with polydipsia-hyponatremia: an MRI pilot study.

We conducted an MRI pilot study of three schizophrenic patients with the syndrome of polydipsia-hyponatremia. Paired MRI scans were obtained at baseline and in the water-loaded state to study the acute effects of water loading and accompanying changes in serum sodium and osmolality on brain structures. We report the pilot data on the observed individual MRI changes of reduced volume of the lateral ventricles in all three patients, and the third ventricles in two patients, in the water-loaded state. These changes were not statistically significant possibly because of small sample size.

Adult↗

Effects of haloperidol, lithium, and valproate on phosphoinositide turnover in rat brain.

The effects of acute, subacute, and chronic treatment with haloperidol, lithium, and valproate on inositol phosphate (IP) formation were examined. Acute treatment with haloperidol or the combination of haloperidol and lithium significantly reduced IP basal cortical levels. Subacute (three days) treatment with lithium decreased the IP basal level in the frontal cortex. Chronic treatment with haloperidol (14 and 28 days) caused a significant attenuation of carbachol-sensitive IP accumulation in the frontal cortex and striatum and a significant decrease in norepinephrine (NE)-induced IP formation in the frontal cortex (14 and 28 days) and striatum (28 days). Lithium treatment for 14 days produced a significant reduction in the IP basal cortical value, and a significant reduction in cortical carbachol- and NE-induced IP formation was found after 28 days of lithium treatment. The combination of haloperidol and lithium for 28 days decreased the striatal carbachol- and cortical NE-induced IP accumulation and caused a significant increase in NE-sensitive IP formation in the striatum at 14 days. Valproate treatment for 28 days was associated with a significant attenuation in striatal agonist-stimulated IP formation. Therefore, three drugs with different specificities for primary neurotransmitters may have common effects on second-messenger systems.

Animals↗