[The official American guidelines for prevention of nosocomial pneumonia. U. S. Centers for Disease Control]

The official German guidelines for prevention of nosocomial pneumonia were published by the Bundesgesundheitsamt, now called Robert-Koch-Institut, twelve years ago. The recently published official "guidelines for prevention of nosocomial pneumonia" of the Centers for Disease Control and Prevention (CDC) are categorized according to scientific evidence. The American guidelines are very detailed and differ in some aspects from the official German guidelines. The purpose of the present paper is to inform the German anaesthesiologist about the official CDC guidelines and to provide a renewed background for the prevention of nosocomial pneumonia.

Thoracoscopic interruption of patent ductus arteriosus compromises cardiopulmonary function in newborn pigs

Interruption of patent ductus arteriosus (PDA) using video-assisted thoracoscopic surgery (VATS) has recently been introduced into clinical practice. To study cardiovascular and pulmonary function during VATS, we treated 16 newborn pigs (weight 1421+/-44 g) with PDA with conventional surgical interruption (CSI; n = 7) or interruption via VATS (n = 9). Measurements of hemodynamics and gas exchange were performed before, during, and after surgery. Systemic perfusion was calculated using Fick's equation. Stress hormones (ACTH, epinephrine, and norepinephrine) were determined before and after surgery. The duration of the surgical procedure was 41+/-8 min for CSI and 49+/-9 min for VATS (mean+/-SEM). With VATS, PaO2 decreased during and after surgery (P < 0.05), whereas alveolar-arterial PO2 difference (PA-aO2) and PaCO2 were increased (P < 0.05). Compared with CSI after surgery, PaO2 with VATS was decreased (130+/-10 vs 171+/-12 mm Hg; P < 0.05). Systemic perfusion was lower during VATS (76.7% of baseline) than during CSI (107% of baseline; P < 0.05). Heart rate, mean arterial pressure, and right ventricular end-diastolic pressure remained unchanged with both treatments. Stress hormones were comparable between groups. We conclude that systemic perfusion and oxygenation were impaired during VATS compared with CSI. Therefore, VATS may be contraindicated in pediatric patients with minor cardiopulmonary reserve.

IMPLICATIONS

We studied the cardiopulmonary effects of endoscopic interruption of the patent ductus arteriosus in an animal model of newborn pigs. Gas exchange and systemic perfusion were impaired compared with conventional interruption of the patent ductus arteriosus after thoracotomy.

How reliable is atrial sensing in single-lead VDD pacing: comparison of three systems

This study evaluated the reliability of atrial sensing, expressed as AV synchronous stimulation, in three VDD systems with the atrial sensitivity (AS) programmed to a conventional value with a 2:1 safety margin compared to most-sensitive values. We studied 34 sex- and age-matched patients with 3 VDD systems: 14 with Unity 292-07, 10 with Saphir 600, and 10 with Thera VDD (5 model 8948 and 5 model 8968i). Two 24-hour Holters were performed on consecutive days. The AS was programmed in a randomized order to its most-sensitive value or to a 2:1 safety margin. All other parameters were programmed identically. The patients underwent a myopotential oversensing test and a daily life activity protocol. A beat-to-beat analysis of the Holters was performed to determine AV synchrony. For the entire group AV synchrony with conventional AS was 98.63% +/- 2.57%, compared to 99.80% +/- 0.43% with most-sensitive values (p = 0.002). There was no difference between the three systems with conventional AS. With the most-sensitive AS, AV synchrony was: Unity 99.99% +/- 0.03%, Saphir 99.42% +/- 0.60% (P = 0.002), Thera 99.81% +/- 0.35% (ns). In the Saphir system with an atrial blanking period of 150 ms, ventricular far-field sensing could be demonstrated in 5 of 10 patients. This reduced the percentage of AV synchrony due to an unwanted mode-switch to a nontracking mode. Myopotential oversensing was not detected in any patient.

CONCLUSION

The VDD systems tested under identical conditions showed reliable P wave sensing at the most-sensitive atrial sensing setting without myopotential oversensing. Ventricular far-field sensing reduced AV synchrony and must be avoided by appropriate refractory periods.

First experience with an automatic sensing algorithm in single-lead VDD stimulation

An "Autosensing" algorithm available in SSI(R) and DDR(R) pacemakers automatically adapts the device's sensitivity to changing intracardiac signals. The atrial sensing function of this algorithm was tested for the first time with a VDD pacing system in which large variations of the atrial signal may occur because the atrial electrodes float in the atrial blood pool.

METHODS

15 patients with a VDD pacing system were studied (Unity 292-07, lead 425; Sulzer Intermedics). The atrial sensing threshold was measured, and the atrial sensitivity was programmed with a 2:1 safety margin. The autosensing algorithm and sensitivity profile were temporarily activated, and an ambulatory ECG with continuous marker annotation was recorded. All patients underwent a 30-minute daily life activities protocol. A beat-to-beat analysis of the ambulatory ECG was correlated with the changes in atrial sensitivity.

RESULTS

The algorithm changed the baseline sensitivity from 0.57 +/- 0.23 mV during the test to 0.39 +/- 0.20 mV after the final rest period (P < 0.05). During the test 12.6 +/- 10.2 adaptations of the sensitivity occurred (range 0-33). In eight patients atrial undersensing occurred in 4.4% +/- 7.5% of the cycles (4-458 unsensed P waves). In these patients, the algorithm continuously adjusted the sensitivity towards more sensitive values, operating 19.1 +/- 18.3 changes compared with 5.4 +/- 7.3 changes in patients without undersensing (P = 0.009). Oversensing did not occur.

CONCLUSION

The autosensing algorithm effectively optimized atrial sensitivity in VDD pacing. In patients with atrial undersensing the algorithm continuously remained near the most sensitive settings, thus reacting as intended. A faster sensitivity adjustment of the system would be desirable.

Clinical profile of saruplase: angiographic findings

Saruplase is a relatively new fibrinolytic drug. Dose finding studies indicated that 70-80 mg saruplase given intravenously results in a high perfusion rate. With a 20 mg bolus followed by a 60 mg infusion over 1 h, a rapid and complete restoration of blood flow can be achieved in a fairly high number of patients. This dose regimen was used in subsequent studies comparing saruplase with other thrombolytic agents. The PRIMI (Pro-urokinase In Myocardial Infarction) study compared saruplase with streptokinase. Early patency rate at 60 min (TIMI grade 2 and 3 flow) was significantly higher with saruplase (71.8%) than with streptokinase (48.0%). In the SESAM (Study in Europe with Saruplase and Alteplase in Myocardial Infarction) study comparing saruplase with alteplase, at 60 min patency rate was 79.9% versus 75.3%, respectively, and at 90 min the rate was 79.9% versus 81.4%, respectively. In the LIMITS (Liquemin in Myocardial Infarction during Thrombolysis with Saruplase) study a heparin bolus of 5000 IU was shown to have an important impact on patency rate. Both heparin and acetylsalicylic acid are recommended as adjunctive therapy before fibrinolysis with saruplase. The reocclusion rates within 24-40 h were between 0.9% and 2.4% in the saruplase studies. There is some variation in estimating whether patency rates are higher with anterior or with inferior infarctions. Saruplase appears to be equally effective in the treatment of infarction in both locations.

Paroxysmal atrial fibrillation and high degree AV block: use of single-lead VDDR pacing with mode switching

Dual chamber rate responsive pacing incorporating a mode switching option is increasingly used in patients with chronic paroxysmal atrial fibrillation and high degree AV block. Single-lead VDDR pacemakers have rarely used for this indication. The purpose of this study was to determine their reliability of atrial sensing during atrial fibrillation, the percentage of atrial synchronous ventricular pacing, and the behavior of the sinus rate outside the phases of atrial fibrillation. We studied ten patients with a single-lead VDDR pacemaker implanted for this indication. Follow-up visits were performed at predischarge and after 1, 3, 6, 12, 18, and 24 months. During the mean follow-up period of 18.9 +/- 6.9 months, the atrial sensing thresholds in sinus rhythm remained stable. Atrial synchronous ventricular stimulation was achieved in 68.7 +/- 31.2% (median 82.5%) of the whole follow-up time. All patients showed an adequate atrial rate response during sinus rhythm. Atrial fibrillation was detected by the pacemakers in 24.0 +/- 29.8% of time. In 3 of 10 patients the duration of atrial fibrillation showed a steady increase from visit to visit. The sensed amplitudes of atrial fibrillation ranged from 0.1-1.0 mV. A programmed atrial sensitivity of 0.1 mV was necessary to achieve complete sensing of atrial fibrillation. None of the patients experienced tachycardias with optimized pacemaker programming. Single-lead VDDR pacing incorporating a mode-switching option is useful in patients with high degree AV block and paroxysmal atrial fibrillation, since it provides atrial synchronous ventricular pacing in more than two-thirds of follow-up time. In a subgroup of patients, a progressive increase of the time during atrial fibrillation was demonstrated. A reliable detection of paroxysmal atrial fibrillation requires the programming of the atrial sensitivity to its most sensitive value.

Unit-based acute confusion resource nurse: an educational program to train staff nurses

Despite the high prevalence of acute confusion among elders and the importance of its early detection, there are few reports of systematic efforts to increase staff competence. This article describes the development and evaluation of an 8-hour educational program designed to prepare staff nurses to perform in a new role, the unit-based acute confusion Resource Nurse (ACRN). Pre- and posttest scores were obtained for the 80 registered nurses who participated in the program. Paired t tests showed that knowledge and confidence significantly increased for participants as a result of their participation in the educational program. This program can serve as an effective model for geriatric staff education.

[Flow quantification of intracardiac shunt volumes using MR phase contrast technique in the breath holding phase]

PURPOSE

Comparison of a breath-hold, velocity-encoded, phase-difference magnetic resonance (MR) sequence for intracardiac shunt flow measurement with the invasive shunt size determination by oximetry.

PATIENTS AND METHODS

10 patients with different cardiac shunts (6 ASD/3 VSD/1 PDA) and four healthy individuals were investigated using a 1.5 Tesla Siemens Vision system. For flow measurements a breath-hold, velocity-encoded, phase-difference magnetic resonance (MR) sequence was used ('through plane', FLASH 2D-sequence, TR/TE 110/5 ms, 'velocity encoding' 250 cm/s). Mean flow (ml/R-R interval) in the ascending aorta, the pulmonary trunk, and the right and left pulmonary arteries was determined. The ratio of the mean flow in the pulmonary circulation (Qp: sum of the mean flows in the right and left pulmonary arteries) and the systemic circulation (Qs: mean flow in the proximal aorta) was compared with the Qp/Qs ratios determined by the invasive oxymetric technique. Oximetry was performed within 24 hours after MR imaging.

RESULTS

In the 4 healthy individuals MR flow measurement yielded a Qp/Qs ratio of 0.96 +/- 0.15. In the 10 patients with the various shunt defects, the non-invasive shunt determination by MR gave a Qp/Qs ratio of 2.09 +/- 0.67. The percentage of the calculated shunt sizes was 47.05 +/- 17.45%. In the comparison with the results determined by the invasive oxymetric technique, the MR data showed a strong correlation of r = 0.87.

CONCLUSIONS

Breath-hold, velocity-encoded, phase-difference MR-technique enables a reliable quantification of cardiac shunts within a short acquisition time.

Impact of routine angiographic follow-up after angioplasty

BACKGROUND

There is an ongoing controversy as to whether repeat coronary angiography should be routinely performed after successful percutaneous transluminal coronary angioplasty (PTCA).

METHODS

We examined the 10-year outcome in 400 patients who had or had not undergone an angiographic control 6 months after successful PTCA and a subsequent event-free 6-month period. Our comparison was based on data gathered by questionnaire and telephone interview in 315 patients with (group A) and 85 patients without (group B) a routine 6-month angiographic control. Multivariate analysis (Cox model) was performed to identify predictors of adverse events.

RESULTS

During the 10-year follow-up period, 22 (7%) of the 315 patients in group A died, compared with 16 (19%) patients in group B (P= .003). In groups A and B, respectively, acute myocardial infarction occurred in 28 (9%) and 10 (12%) patients (not significant [NS]); coronary artery bypass grafting (CABG) was performed in 42 (13%) and 14 (16%) patients (NS); repeat PTCA was performed in 89 (28%) and 11 (13%) patients (P= .012); and serious adverse events (death, myocardial infarction, CABG) occurred in 76 (24%) and 32 (38%) patients (P= .02). Absence of a 6-month angiographic follow-up was identified as an independent predictor of death associated with a 2.7 times higher mortality rate during the 10-year follow-up period. Previous myocardial infarction increased the risk of death 2.5 times. Any increase of residual diameter stenosis by 10% was combined with a 1.4 times higher mortality rate. The chance of bypass surgery was higher in patients with multivessel disease (2.9 times), in patients with unstable angina (2.1 times), and in case of an increase of residual diameter stenosis by 10% (1.3 times). No predictor for the risk of myocardial infarction was found. Angiographic follow-up increased the likelihood of PTCA 2.5 times.

CONCLUSIONS

A routinely performed angiographic control 6 months after successful PTCA is associated with a significantly higher rate of repeat PTCA but, most important, is correlated with a significantly lower mortality rate during the 10-year follow-up period.

Changes of neurohumoral parameters and endothelin-1 in response to exercise in patients with mild to moderate congestive heart failure

Plasma endothelin levels are increased in patients with moderate and severe CHF. Conflicting data exist about the endothelin-1 (ET) level in patients with mild to moderate CHF and the effect of maximal exercise on plasma ET levels.

METHODS AND RESULTS

We determined the plasma levels of ET and various neurohumoral parameters in 93 patients with CHF in functional class II and III of the NYHA classification at rest and after maximal bicycle exercise. Baseline ET level was increased compared to an age-matched healthy volunteer group (6.95+/-0.31 vs 3.29+/-0.17 pg/ml, mean+/-S.E.M., P<0.05), without significant differences between NYHA class II and III patients. Maximal exercise did not increase the ET level. In contrast, the neurohumoral parameters were significantly increased with maximal exercise. In conclusion, plasma levels of ET are increased in patients with mild to moderate CHF. However, no further increase in response to exercise was observed. Thus, it is highly unlikely that exercise capacity may be limited by ET-mediated peripheral vasoconstriction.

The alpha-chemokine, stromal cell-derived factor-1alpha, binds to the transmembrane G-protein-coupled CXCR-4 receptor and activates multiple signal transduction pathways

The alpha-chemokine stromal cell-derived factor (SDF)-1alpha binds to the seven transmembrane G-protein-coupled CXCR-4 receptor and acts to modulate cell migration and proliferation. The signaling pathways that mediate the effects of SDF-1alpha are not well characterized. We studied events following SDF-1alpha binding to CXCR-4 in a model murine pre-B cell line transfected with human CXCR-4. There was enhanced tyrosine phosphorylation and association of components of focal adhesion complexes such as the related adhesion focal tyrosine kinase, paxillin, and Crk. We also observed activation of phosphatidylinositol 3-kinase. Wortmannin, a selective inhibitor of phosphatidylinositol 3-kinase, partially inhibited the SDF-1alpha-induced migration and tyrosine phosphorylation of paxillin. SDF-1alpha treatment selectively activated p44/42 mitogen-activated protein kinase (Erk 1 and Erk 2) and its upstream kinase mitogen-activated protein kinase kinase but not p38 mitogen-activated protein kinase, c-Jun amino-terminal kinase or mitogen activated protein kinase kinase. We also observed that SDF-1alpha treatment increased NF-kappaB activity in nuclear extracts from the CXCR-4 transfectants. Taken together, these studies revealed that SDF-1alpha activates distinct signaling pathways that may mediate cell growth, migration, and transcriptional activation.

Evidence for opening of hair-cell transducer channels after tip-link loss

The mechanosensitive transducer channels of hair cells have long been proposed to be gated directly by tension in the tip links. These are thin, elastic extracellular elements connecting the tips of adjacent stereocilia located on the apical surface of the cell. If this hypothesis is true, the channels should close after destruction of tip links. The hypothesis was tested pharmacologically using receptor currents obtained in response to mechanical stimulation of the stereociliary bundle of outer hair cells isolated from the adult guinea pig cochlea. Application of elastase (20 U/ml) or 1,2-bis(2-aminophenoxy)ethane-N,N,N', N'-tetra-acetic acid (BAPTA; 5 mM), both of which are known to disrupt tip links in other hair-cell preparations, led to the expected irreversible loss of receptor currents. However, the cells then displayed a maintained inward current, implying that channels were left permanently open. This current was similar in magnitude to the receptor current before treatment and was reduced reversibly by known blockers of mechanosensitive channels, namely, dihydrostreptomycin (100 microM), amiloride (300 microM), and gadolinium ions (1 mM). These observations suggest that the maintained current flows through the mechanosensitive channels. Electron microscopical analysis of isolated hair cells, exposed to the same concentrations of elastase or BAPTA as in the electrophysiological experiments, demonstrated an almost total loss of tip links in hair bundles that showed no evidence of other mechanical damage. It is concluded that although the tip links are required for mechanoelectrical transduction, the channels are not gated directly by the tip links.

[Hemodynamic effects of a single intravenous administration of prostaglandin E1 in a patient sample with chronic NYHA-stage II/III heart failure]

We investigated the hemodynamic effects of a single infusion of PGE1 (60 micrograms infused over a period of 2 h--this is the single dose used in courses of treatment for peripheral occlusive arterial disease) in patients with chronic heart failure NYHA class II-III. The ejection fraction of these patients was < 55%, their average age was 58.4 years (standard deviation 10 years), and their condition was stable. Nineteen of the patients had coronary heart disease and one patient had myocarditis. The hemodynamic data were obtained invasively by catheterization of the right and left heart. Blood pressure and pulse rate were measured manually. Intravenous infusion of 60 micrograms PGE1 over a period of 2 hours did not significantly alter contractility or hemodynamics. Dp/dtmax, dp/dtmax/p, and dp/dt DP40, which are parameters of left ventricular contractility, determined with the aid of a catheter-tip manometer, did not differ significantly over time from those in the placebo control group. Similarly, the other data furnished no evidence that administration of PGE1 had any hemodynamic or myocardial effects. Hence, it is reasonable to state that it is safe to administer PGE1 to patients with peripheral occlusive arterial disease.

Clinical and morphological characteristics in Streptococcus bovis endocarditis: a comparison with other causative microorganisms in 177 cases

AIM

To compare the clinical and morphological characteristics of patients with Streptococcus bovis endocarditis with those of patients with endocarditis caused by other microorganisms.

METHODS

177 consecutive patients (Streptococcus bovis, 22; other streptococci, 94; staphylococci, 44; other, 17) with definite infective endocarditis according to the Duke criteria were included. All patients underwent transthoracic and transoesophageal echocardiography. In 88 patients, findings from surgery/necropsy were obtained.

RESULTS

S bovis endocarditis was associated with older patients, with a higher mortality (p = 0.04), and with a higher rate of cardiac surgery (p < 0.001) than other microorganisms, although embolic events were observed less often (p = 0.02). Pathological gastrointestinal lesions were detected in 45% of the patients. Multiple valves were affected in 68% of the patients with S bovis endocarditis and in 20% of those with other organisms (p < 0.001). Moderate or severe regurgitation occurred more often in S bovis endocarditis than with other microorganisms (p = 0.05). When surgery or necropsy was performed, infectious myocardial infiltration of the left ventricle was confirmed histopathologically in 36% of the patients with S bovis endocarditis and in 10% of those with other organisms (p = 0.002).

CONCLUSIONS

S bovis endocarditis is a severe illness because of the more common involvement of multiple valves, and of the frequent occurrence of haemodynamically relevant valvar regurgitation and infectious myocardial infiltration.

The transition from hospital to long-term institutional care

The focus of this article is user and carer involvement in the transition of older people from acute hospital to continuing institutional long-term care. The policy context and research of relevant studies are reviewed. Findings from an action research project currently in progress further elucidate the concerns of older users and carers.

Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in young Chinese adults

The aim of this study was to determine the presence or absence of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in young Chinese adults and to examine the A. actinomycetemcomitans isolates from positive subjects with regard to the serotype distribution, presence of the leukotoxin gene lktA and the promoter for the leukotoxin operon as well as the incidence of phage Aa phi 23. Sixty subjects, working in a knitting factory in the Province of Guangzhou, People's Republic of China, were investigated. Subgingival microbial samples were taken from both upper first molars. They were cultured both anaerobically and in 5% CO2. P. gingivalis was found in 33 subjects. On average, it constituted 7% of the total anaerobic cultivable counts. A. actinomycetemcomitans was detected in 37 subjects of which seven yielded counts > 10(5). Twenty-one subjects were positive for both organisms. A. actinomycetemcomitans serotype a was found in 9 subjects, serotype c was found in 23 and serotype e in 5. A. actinomycetemcomitans serotypes b and d were not detected in any subjects. Presence of the leukotoxin gene lktA was demonstrated for all A. actinomycetemcomitans isolates; however, none of the A. actinomycetemcomitans strains from the present study had a deletion in the promoter region of the leukotoxin operon. The results of this investigation show a high frequency of the putative periodontal pathogens P. gingivalis and A. actinomycetemcomitans and corroborate the concept that there is variation in virulence and pathogenic potential among isolates from different subjects.

Detection of coronary artery calcifications predicting coronary heart disease: comparison of fluoroscopy and spiral CT

The aim of this study was to evaluate the clinical relevance of coronary artery calcifications detected by spiral CT, congruence with fluoroscopy (FS) and coronary angiography, and comparison with studies reporting on application of double-helical CT and ultrafast CT. Forty patients underwent spiral CT (2-mm slice thickness, table feed 3 mm/s), coronary angiography, and FS (performed in the usual manner). Stenosis and calcifications were evaluated semiquantitatively. Nineteen patients suffering from a stenosis >/= 75 % were verified at coronary angiography. All had coronary artery calcification on spiral CT. Fluoroscopy did not detect 8 of 19 patients with a stenosis >/= 75 % (1 vessel: n = 1; 2 vessels: n = 3; 3 vessels: n = 4). In spiral CT sensitivity was 100 % and specificity was 33 % (FS: 58 and 48 %). Positive predictive value was 83 % for spiral CT (FS: 50 %), and negative predictive value was 100 % (FS: 56 %). A significant linear increase in the calcification score was found for increasing maximal stenosis (p < 0.005). Spiral CT is more sensitive than FS in the recognition of hemodynamic relevant stenoses using the detection of coronary artery calcifications. Statistical parameters are comparable to ultrafast-CT. Spiral CT is a suitable non-invasive diagnostic technique in coronary heart disease. Coronary calcifications found incidentally in symptomatic patients at chest CT should be reported to the referring physician for further cardiological workup.

Extensive ligand rearrangements around the [2Fe-2S] cluster of Clostridium pasteurianum ferredoxin

The [2Fe-2S] cluster of the ferredoxin from Clostridium pasteurianum is coordinated by cysteines 11, 56, and 60 and by a fourth cysteine, residue 24 in the wild-type protein, located on a flexible and deletable loop around residues 14-30. New mutated forms of this ferredoxin show that the fourth cysteine ligand can be located in any one of positions 14, 16, 21, 24, or 26. Another set of molecular variants has unveiled a new case of ligand swapping on the cysteine 60 ligand site. Replacement of cysteine 60 by alanine and introduction of a cysteine in position 21 yielded a ferredoxin that assembles a [2Fe-2S] cluster of which the ligands are cysteines 11, 21, 24, and 56. This cysteine ligand pattern is similar to that occurring in plant-type or mammalian-type ferredoxins, although the overall sequence similarities are below detection. Moreover, the vibrational and electronic properties of the resulting [2Fe-2S]2+/+ center, as revealed by resonance Raman and EPR studies, are strikingly similar to those of mammalian-type ferredoxins. The extensive set of mutated forms of the C. pasteurianum ferredoxin now available indicates that cysteine ligand exchange may occur on residues 24 and 60, but not on residues 11 and 56. It is thus suggested that cysteines 24 and 60 are part of a solvent accessible aspect of the Fe-S cluster, whereas cysteines 11 and 56 are buried and form the more rigid part of the polypeptide ligand framework. In view of the unprecedented versatility of this [2Fe-2S] cluster and of its polypeptidic environment, the introduction of ligands other than cysteine in various positions has been attempted. These experiments have remained unsuccessful, and even including previous studies, noncysteinyl ligation has been obtained with this protein in only very few cases. The data provide an extensive confirmation that Fe-S clusters have a strong preference for thiolate ligation and rationalize the relatively rare occurrence of noncysteinyl ligation in native Fe-S proteins.

NIMH Genetics Initiative Millenium Schizophrenia Consortium: linkage analysis of African-American pedigrees

The NIMH Genetics Initiative is a multi-site collaborative study designed to create a national resource for genetic studies of complex neuropsychiatric disorders. Schizophrenia pedigrees have been collected at three sites: Washington University, Columbia University, and Harvard University. This article-one in a series that describes the results of a genome-wide scan with 459 short-tandem repeat (STR) markers for susceptibility loci in the NIMH Genetics Initiative schizophrenia sample-presents results for African-American pedigrees. The African-American sample comprises 30 nuclear families and 98 subjects. Seventy-nine of the family members were considered affected by virtue of having received a DSMIII-R diagnosis of schizophrenia (n = 71) or schizoaffective disorder, depressed (n = 8). The families contained a total of 42 independent sib pairs. While no region demonstrated evidence of significant linkage using the criteria suggested by Lander and Kruglyak, several regions, including chromosomes 6q16-6q24, 8pter-8q12, 9q32-9q34, and 15p13-15q12, showed evidence consistent with linkage (P = 0.01-0.05), providing independent support of findings reported in other studies. Moreover, the fact that different genetic loci were identified in this and in the European-American samples, lends credence to the notion that these genetic differences together with differences in environmental exposures may contribute to the reported differences in disease prevalence, severity, comorbidity, and course that has been observed in different racial groups in the United States and elsewhere.

Genome scan of European-American schizophrenia pedigrees: results of the NIMH Genetics Initiative and Millennium Consortium

The Genetics Initiative of the National Institute of Mental Health (NIMH) was a multisite study that created a national repository of DNA from families informative for genetic linkage studies of schizophrenia, bipolar disorder, and Alzheimer's disease. The schizophrenia families were collected by three sites: Washington University, Harvard University, and Columbia University. This article, one in a series that describes the data collected for linkage analysis by the schizophrenia consortium, presents the results for the European-American sample. The European-American sample comprised 43 nuclear families and 146 subjects. Ninety-six of the family members were considered affected by virtue of having received a DSM-III-R diagnosis of schizophrenia (N = 82) or schizoaffective disorder, depressed (N = 14). The families contained a total of 50 independent sib-pairs. Using the significance threshold criteria suggested by Lander and Kruglyak [(1995): Nat Genet 241-247], no region showed statistically significant evidence for linkage; two markers on chromosome 10p showed statistical evidence suggestive of linkage using the criteria of Lander and Kruglyak [(1995): Nat Genet 241-247]: D10S1423 (nonparametric linkage (NPL) Z = 3.4, P = .0004) and its neighbor, D10S582 (NPL Z = 3.2, P = .0006).