Subclinical impairment of brain function in chronic hepatitis C infection

BACKGROUND/AIMS: Central nervous system abnormalities such as fatigue and depression occur more frequently in chronic hepatitis C virus (HCV) infection than in many other causes of chronic liver disease. The finding that fatigue is unrelated to activity of hepatitis or mode of infection could indicate an independent effect of HCV on brain function. This study tested the hypothesis of a subclinical cognitive dysfunction in HCV-infected patients. METHODS: One-hundred untreated HCV-RNA positive biopsy-proven patients were investigated by P300 event-related potentials, a sensitive electrophysiologic test of cognitive processing. Health-related quality of life and fatigue were assessed using the SF-36 questionnaire and the Fatigue Impact Scale, respectively. RESULTS: Cognitive brain function was subclinically impaired in the cohort of HCV-infected patients as indicated by significantly prolonged P300 latencies (P=0.01 for comparison to matched healthy subjects) and reduced P300 amplitudes (P<0.001, respectively). Seventeen of the 100 HCV-infected patients had P300 latencies outside the age-adjusted normal range. Abnormal P300 characteristics were not related to the degree of histologic or biochemical activity of hepatitis, severity of fatigue or mental health impairment. CONCLUSIONS: This study demonstrates that patients with HCV infection showed a slight but significant neurocognitive impairment, possibly indicating a further extrahepatic manifestation of chronic hepatitis C.     

Genomewide production of multipurpose alleles for the functional analysis of the mouse genome

A type of retroviral gene trap vectors has been developed that can induce conditional mutations in most genes expressed in mouse embryonic stem (ES) cells. The vectors rely on directional site-specific recombination systems that can repair and re-induce gene trap mutations when activated in succession. After the gene traps are inserted into the mouse genome, genetic mutations can be produced at a particular time and place in somatic cells. In addition to their conditional features, the vectors create multipurpose alleles amenable to a wide range of post-insertional modifications. Here we have used these directional recombination vectors to assemble the largest library of ES cell lines with conditional mutations in single genes yet assembled, presently totaling 1,000 unique genes. The trapped ES cell lines, which can be ordered from the German Gene Trap Consortium, are freely available to the scientific community.     

Type IIB von Willebrand's disease: gene mutations and clinical presentation in nine families from Denmark, Germany and Sweden

Summary Type IIB of von Willebrand's disease (vWD) is a variant in which the structurally abnormal von Willebrand factor (vWF) shows an increased affinity for the platelet vWF receptor, glycoprotein Ib (GPIb). This may sometimes give rise to platelet aggregation and thrombocytopenia in vivo. In 20 patients from nine unrelated families with type IIB vWD from Denmark, Germany and Sweden we studied the molecular defect by amplification and direct sequencing of parts of exon 28 which encode for the vWF domain that interacts with platelet GPIb. Three different point mutations were identified one of which has not previously been reported. Fifteen patients from five families were heterozygous for the Arg⁵⁴³Trp substitution. The mutation had occurred independently in all five families and in two of them represented a de novo mutation. In one of these families the father, though asymptomatic and with normal laboratory test results, carried the mutation in heterozygous form. In three families, four affected members were found to be heterozygous for the Arg⁵⁴³°Cys substitution. The mutations were of different origin at least in two of the families. The third substitution, Val⁵⁵⁴Leu, which has not previously been described, was found in one patient and was due to a de novo mutation. In most of the patients spontaneous thrombocytopenia had been recorded on at least one occasion. Five of the patients with the Arg⁵⁴³Trp substitution and the one with the Val⁵⁵⁵Leu substitution had all had bleeding associated with thrombocytopenia in the neonatal period of early infancy.     

CD44 expression in benign and malignant colorectal polyps

PURPOSE: This retrospective study was undertaken to evaluate immunohistochemically the expression of CD44 standard protein and CD44v5 and CD44v6 isoforms in colorectal adenomas and early invasive cancers developing within adenomas as possible markers characterizing colorectal polyps with a more aggressive biologic potential. METHODS: Archival tissues of 81 consecutive locally resected colorectal polyps, comprising 57 colorectal adenomas and 24 carcinomas-in-adenomas, were stained immunohistochemically with the use of commercially available mouse monoclonal antibodies: SFF-2 for CD44 standard protein, VFF-8 for CD44v5, and VFF-7 for CD44v6. RESULTS: Sixtythree percent of the colorectal polyps were positive for CD44 standard protein, 59 percent were positive for CD44v5, and 27 percent were positive for CD44v6. Ninetythree percent of the low-grade adenomas were CD44 standard protein-positive, in contrast to 50 percent of the high-grade adenomas and only 42 percent of the carcinomas-in-adenomas (Kendall's Tau =–0.42;P<0.0001). CD44v6 expression was more frequently found in early invasive cancers (54 percent) than in high-grade adenomas (25 percent) and low-grade adenomas (7 percent). This difference also was statistically significant (Kendall's Tau-b =0.39;P=0.00003). Surprisingly, a downregulation of CD44 standard protein expression was observed in the adenoma tissue adjacent to carcinomas (62 percent) and areas with high-grade atypia (71 percent), compared with low-grade adenomas (93 percent; Kendall's Tau-b =–0.28;P=0.004). CONCLUSIONS: Our data suggest that CD44 standard protein and CD44 isoform v6 expression differs considerably in benign and malignant colorectal polyps. Clinical studies with larger patient groups could clarify the prognostic potential of CD44 further     

Identifikation akut-geriatrischer PatientInnen in der Freien und Hansestadt Hamburg (“Direkterhebung”)

Zusammenfassung Die Berechnung eines station?ren Leistungsangebotes (“Bettenbedarfs”) erfolgte in der Vergangenheit vorwiegend über diagnosebezogene Fallzahlstatistiken (Krankenhausf?lle). Die Entscheidung für die station?re Versorgung in einer geriatrischen Abteilung wird jedoch zus?tzlich durch Faktoren wie “Selbsthilfestatus”, “soziales Umfeld” und “Komorbidit?t” entschieden. Diese k?nnen direkt am Patienten ermittelt oder durch die Befragung der Pflege und/oder des ?rztlichen Dienstes erfa?t werden. Für diese Befragung wird ein neues Me?instrument vorgestellt. Das Kernstück bildet der Barthel-Index (BI). Flankierend erfolgt die Aufnahme der Eckdaten zur sozialen Situation sowie die Erfassung des modifizierten Screenings nach Lachs. Das dreiteilige Me?instrument wurde vom 6. September bis 14. Dezember 1997 an sieben Hamburger Kliniken (darunter eine Universit?tsklinik und eine geriatrieführende Klinik) im Rahmen einer repr?sentativen Stichprobe eingesetzt. Die gesammelten Daten erfassen 18 Aufnahmetage aller 60j?hrigen und ?lteren, welche am Tag der Befragung den fünften Tag im jeweiligen Akutkrankenhaus verbrachten. An einigen Kliniken wurden zus?tzlich Daten ab dem dritten bzw. bis zum sechsten Tag nach Aufnahme erfa?t. Insgesamt wurde durch die ermittelten Daten eine ganze “virtuelle Tagesaufnahme” der 60j?hrigen und ?lteren am fünften Tag für die Stadt Hamburg erfa?t. Von 425 Patienten waren 137 bereits vor der Befragung verlegt oder entlassen worden, 4 waren verstorben. Von den verbliebenen 284 PatientInnen lehnten 2 die Befragung ab, die Daten von 6 PatientInnen waren nicht auswertbar; somit wurden 276 PatientInnen befragt. Von diesen stellen 231 “keine potentiellen KandidatInnen für eine Geriatrie oder geriatrische Tagesklinik” dar, 8 sind “KandidatInnen für eine geriatrische Tagesklinik direkt nach der Entlassung aus der Prim?rversorgung”, und 37 sind “KandidatInnen für eine station?re Geriatrie”. Der vorgestellte dreiteilige Frage- und Befundbogen zeigt eine Sensitivit?t von 89,2% und eine Spezifit?t von 92,2%. In den H?nden eines geschulten Untersuchers stellt das Me?instrument sowohl im Rahmen des geriatrischen Konsils als auch für die Ermittlung eigener direkt erhobener statistischer Kenndaten “potentieller Kandidaten für eine station?re Geriatrie” ein valides und in der Handhabung praktisches “Handwerkszeug” dar. Eingegangen: 26. Juni 1998, Akzeptiert: 7. Juli 1998     

Functional determination of plasminogen activator in arginine-stabilized plasma.

Reliable data on plasminogen activator (PA) activities in blood of patients receiving fibrinolytic treatment are lacking. This is due to the continuing in vitro action of PA after blood withdrawal. We have elaborated a new simple stabilization technique for plasma involving the addition of arginine in final concentrations greater than 500 mM. In this study, new assays for PA in stabilized plasma are developed. The assay was performed with substrate plasma, that is, pooled normal plasma, preoxidized with chloramine-T; oxidant amount and oxidation time were optimized. The chloramine consumption by plasma was assayed with a KJ-assay (absorbance increase at 405 nm by addition of 200 microL 4 M KJ to 25 microL oxidized plasma). The substrate plasma concentration in the PA assay and the PA acting time was optimized. The inhibition of PA by the cations Na(+), K(+), Mg(2+), and Ca(2+) was evaluated. The optimized PA assay consists of incubation of 10 microL arginine-stabilized plasma with 10 microL 1.5 M arginine, pH 8.7 and 10 microL 100 mM CT in PBS. After 30 minutes (37 degrees C), 175 microL 15 mM CT oxidized EDTA plasma are added. After 40 minutes (37 degrees C), 75 microL Stop-CS Reagent is added and DeltaA at 405 nm was determined, giving PA + plasmin activity in plasma. A control value (basal plasmin activity) consists of the addition of Stop-CS Reagent before 175 microL oxidized EDTA plasma. To obtain plasmatic PA activity, the control value has to be subtracted from the PA main value. The assay is matrix-independent and linear up to 1250 IU/mL t-PA, 790 U/mL reteplase, or 199 IU/mL u-PA (37 nM). With arginine stabilization of plasma and the described determination of plasminogen activator activity in arginine-stabilized plasma, it is feasible to determine the activity of plasminogen activators in blood of patients receiving fibrinolytic treatment without artefactual in vitro changes of the samples.     

Functional-task exercise versus resistance strength exercise to improve daily function in older women: a randomized, controlled trial

OBJECTIVES: To determine whether a functional-task exercise program and a resistance exercise program have different effects on the ability of community-living older people to perform daily tasks. DESIGN: A randomized, controlled, single-blind trial. SETTING: Community leisure center in Utrecht, the Netherlands. PARTICIPANTS: Ninety-eight healthy women aged 70 and older were randomly assigned to the functional-task exercise program (function group, n=33), a resistance exercise program (resistance group, n=34), or a control group (n=31). Participants attended exercise classes three times a week for 12 weeks. MEASUREMENTS: Functional task performance (Assessment of Daily Activity Performance (ADAP)), isometric knee extensor strength (IKES), handgrip strength, isometric elbow flexor strength (IEFS), and leg extension power were measured at baseline, at the end of training (at 3 months), and 6 months after the end of training (at 9 months). RESULTS: The ADAP total score of the function group (mean change 6.8, 95% confidence interval (CI)=5.2-8.4) increased significantly more than that of the resistance group (3.2, 95% CI=1.3-5.0; P=.007) or the control group (0.3, 95% CI=-1.3-1.9; P<.001). Moreover, the ADAP total score of the resistance group did not change significantly compared with that of the control group. In contrast, IKES and IEFS increased significantly in the resistance group (12.5%, 95% CI=3.8-21.3 and 8.6%, 95% CI=3.1-14.1, respectively) compared with the function group (-2.1%, 95% CI=-5.4-1.3; P=.003 and 0.3%, 95% CI=-3.6-4.2; P=.03, respectively) and the control group (-2.7%, 95% CI=-8.6-3.2, P=.003 and 0.6%, 95% CI=-3.4-4.6; P=.04, respectively). Six months after the end of training, the increase in ADAP scores was sustained in the function group (P=.002). CONCLUSION: Functional-task exercises are more effective than resistance exercises at improving functional task performance in healthy elderly women and may have an important role in helping them maintain an independent lifestyle.     

The crystal structure of avian CD1 reveals a smaller,more primordial antigen-binding pocket compared to mammalian CD1

The molecular details of glycolipid presentation by CD1 antigen-presenting molecules are well studied in mammalian systems. However, little is known about how these non-classical MHC class I (MHCI) molecules diverged from the MHC locus to create a more complex, hydrophobic binding groove that binds lipids rather than peptides. To address this fundamental question, we have determined the crystal structure of an avian CD1 (chCD1–2) that shares common ancestry with mammalian CD1 from ≈310 million years ago. The chCD1–2 antigen-binding site consists of a compact, narrow, central hydrophobic groove or pore rather than the more open, 2-pocket architecture observed in mammalian CD1s. Potential antigens then would be restricted in size to single-chain lipids or glycolipids. An endogenous ligand, possibly palmitic acid, serves to illuminate the mode and mechanism of ligand interaction with chCD1–2. The palmitate alkyl chain is inserted into the relatively shallow hydrophobic pore; its carboxyl group emerges at the receptor surface and is stabilized by electrostatic and hydrogen bond interactions with an arginine residue that is conserved in all known CD1 proteins. In addition, other novel features, such as an A′ loop that interrupts and segments the normally long, continuous α1 helix, are unique to chCD1–2 and contribute to the unusually narrow binding groove, thereby limiting its size. Because birds and mammals share a common ancestor, but the rate of evolution is slower in birds than in mammals, the chCD1–2-binding groove probably represents a more primordial CD1-binding groove.     

Rhabdomyomatous dysplasia of the newborn lung associated with multiple congenital malformations of the heart and great vessels

Interstitial proliferation of striated muscle in the lung is extremely rare. Most cases are associated with other congenital malformations, such as lung sequestration, diaphragmatic hernia, or cardiac malformations. We describe a newborn with rhabdomyomatous dysplasia of the lung associated with multiple congenital malformations of the heart and great vessels. The female neonate was born at 37 weeks of gestation as the second child to a 31-year-old woman without relevant previous medical or family history. In week 26 of gestation, a complex heart malformation and polyhydramnion were diagnosed by ultrasound. Postnatally, right lung hypoplasia, a bilobar right and left lung, anomalous drainage of the pulmonary veins, atrial and ventricular septal defects, and double-outlet right-ventricle and multiple aortopulmonary collaterals were described. Histological examination of a biopsy of the right lung demonstrated the presence of numerous bundles of striated muscle fibers arranged randomly in the pulmonary interstitium. Unilateral resection of the right lung was not a therapeutic option, because the left lung had developed bronchopulmonary dysplasia with severe reduction in gas exchange as a consequence of long-term mechanical ventilation. Symptomatic relief and palliative cardiac surgery were offered. At age 5 months, the infant died of a pulmonary hemorrhage following cardiac surgery.