Apparent genotype–phenotype correlation in childhood,adolescent, and adult Chediak‐Higashi syndrome

Chediak‐Higashi syndrome (CHS) is a rare autosomal recessive disorder characterized by severe immunologic defects, reduced pigmentation, bleeding tendency, and progressive neurological dysfunction. Most patients present in early childhood and die unless treated by bone marrow transplantation. About 10–15% of patients exhibit a much milder clinical phenotype and survive to adulthood, but develop progressive and often fatal neurological dysfunction. Very rare patients exhibit an intermediate adolescent CHS phenotype, presenting with severe infections in early childhood, but a milder course by adolescence, with no accelerated phase. Here, we describe the organization and genomic DNA sequence of the CHS1 gene and mutation analysis of 21 unrelated patients with the childhood, adolescent, and adult forms of CHS. In patients with severe childhood CHS, we found only functionally null mutant CHS1 alleles, whereas in patients with the adolescent and adult forms of CHS we also found missense mutant alleles that likely encode CHS1 polypeptides with partial function. Together, these results suggest an allelic genotype–phenotype relationship among the various clinical forms of CHS. © 2002 Wiley‐Liss, Inc.     

A multimethod assessment of behavioral and emotional adjustment in children with asthma

OBJECTIVE: Examine behavioral adjustment and emotion regulation among 6-year-old children with asthma and a group of healthy controls. METHOD: Subjects were 81 children with asthma and 22 healthy controls. Asthma and allergy statuses were confirmed by objective measures. Emotional and behavioral functioning were assessed through parent report, child interview, and child participation in an emotional regulation paradigm. RESULTS: Maternal report revealed more internalizing and total behavior problems for children with asthma compared to controls. Child interview and behavioral observations of emotion regulation yielded no differences between groups. Severity of asthma was related to increased emotional difficulties by clinician interview and observation but not by maternal report. CONCLUSIONS: Two groups of children with asthma who have psychological difficulties include those with increased anxiety and those with poor emotion regulation and more asthma symptoms. Different measures of child adjustment yield a complex picture of the behavioral difficulties associated with pediatric asthma.     

Evaluation of a new molecular assay for detection of human immunodeficiency virus type 1 RNA, hepatitis C virus RNA, and hepatitis B virus DNA.

BACKGROUND: Rapid, sensitive, specific, and cost-effective screening of donated blood to prevent transmission of infectious agents remains challenging. In recent years, incorporation of nucleic acid testing for HIV-1 and HCV RNA improved blood safety by reducing the window period between infection and serologic detection. For HBV infection, this window period with most serologic assays is 50-60 days. Adding a nucleic acid test (NAT) for HBV DNA with existing NATs for HIV-1 and HCV RNA would further improve blood safety and blood screening efficiency. OBJECTIVE: To evaluate the Procleix Ultrio Assay for simultaneous detection of HIV-1 and HCV RNA and HBV DNA and corresponding discriminatory assays. STUDY DESIGN: The performance of these assays, which utilize the same technology and assay format as the Procleix HIV-1/HCV assay, was determined using relevant clinical specimens and analytical sensitivity and specificity panels. RESULTS: The Procleix Ultrio Assay demonstrated specificity of > or =99.5% in healthy donor blood specimens and in plasma containing potentially interfering substances or other blood-borne pathogens. Assay sensitivity demonstrated >95% detection of 100copies/mL, 30IU/mL, and 15IU/mL for HIV-1 and HCV RNA, and HBV DNA, respectively. The assay detects all known HIV-1 subtypes and HCV and HBV genotypes and is highly reproducible. Statistical analysis using receiver operating characteristic plots demonstrated wide analyte cutoff values for each assay associated with assay specificity and sensitivity of > or =99.5%. CONCLUSIONS: In this investigational study, the Procleix Ultrio Assay sensitivity and specificity were similar to existing NATs used in blood-bank settings to detect HIV-1 and HCV RNA and provided equivalent sensitivity and specificity for detection of HBV DNA. Using this combination assay, blood safety may be improved and the multiplex format enhances blood screening efficiency. The throughput capability of this assay is compatible with large volume processing and the chemistry is adaptable to full automation.     

Lassa fever. Effective therapy with ribavirin

In a study of Lassa fever in Sierra Leone, West Africa, we identified two variables associated with a high risk of death, and we evaluated the efficacy of ribavirin and Lassa virus-convalescent plasma for the treatment of Lassa fever. A serum aspartate aminotransferase level greater than or equal to 150 IU per liter at the time of hospital admission was associated with a case-fatality rate of 55 percent (33 of 60). Patients with the same risk factor who were treated for 10 days with intravenous ribavirin, begun within the first 6 days after the onset of fever, had a case-fatality rate of 5 percent (1 of 20) (P = 0.0002 by Fisher's exact test). Patients whose treatment began seven or more days after the onset of fever had a case-fatality rate of 26 percent (11 of 43) (P = 0.01). Viremia with levels greater than or equal to 10(3.6) TCID50 per milliliter on admission was associated with a case-fatality rate of 76 percent (35 of 46). Patients with this risk factor who were treated with intravenous ribavirin within the first six days after onset of fever had a case-fatality rate of 9 percent (1 of 11) (P = 0.006), whereas those treated after seven days or more of illness had a fatality rate of 47 percent (9 of 19) (P = 0.035). Oral ribavirin was also effective in patients at high risk of death. Lassa-convalescent plasma did not significantly reduce mortality in any of the high-risk groups. We conclude that ribavirin is effective in the treatment of Lassa fever and that it should be used at any point in the illness, as well as for postexposure prophylaxis.     

Seven new HLA-B alleles associated with antigens in the B7 CREG

This paper describes seven novel HLA-B alleles. Five of these new alleles contain polymorphic motifs previously reported in HLA-B alleles, suggesting an origin resultant from a gene conversion mechanism. B*0723 contains a polymorphism previously unreported in class I HLA molecules. B*4105 contains a nucleotide substitution previously unreported in class I HLA molecules, which encodes a protein sequence previously reported only in HLA-C locus alleles.     

Noradrenergic modulation of firing pattern in guinea pig and cat thalamic neurons, in vitro

1. The electrophysiological actions of norepinephrine (NE) in the guinea pig and cat thalamus were investigated using intracellular recordings from neurons of in vitro thalamic slices. 2. Application of NE to neurons of the lateral and medial geniculate nuclei, nucleus reticularis, anteroventral nucleus, and the parataenial (PT) nucleus resulted in a slow depolarization associated with a 2- to 15-nS decrease in input conductance and an increase in the slow membrane time constant from an average of 27.7 to 37.7 ms. The slow depolarization was not abolished by blockade of synaptic transmission, indicating that it was a direct (postsynaptic) effect. 3. The reversal potential of the NE-induced slow depolarization varied as a Nernstian function of extracellular potassium concentration ([K]o), indicating that it is due to a decrease in potassium conductance. This conclusion was supported by the finding that the amplitude of the NE-evoked depolarization was affected by changes in [K]o between 0.5 and 5.0 mM as expected for a K-mediated response. 4. Neurons of the PT nucleus displayed unusually large afterhyperpolarizations (AHPs) in comparison to cells in other thalamic nuclei. NE application to PT neurons caused not only a marked slow depolarization and decreased conductance, but also selectively reduced the slow AHP. 5. The NE-induced slow depolarization effectively suppressed burst firing and promoted the occurrence of single spike activity. NE-induced reduction of the slow AHP in PT neurons was accompanied by a decrease in spike frequency accommodation and the emergence of a slow afterdepolarization. 6. We suggest that through these electrophysiological actions, NE can effectively inhibit the generation of thalamocortical rhythms and greatly facilitate the faithful transfer of information through the thalamus to the cerebral cortex.     

Clinical and microbiological features of Aeromonas hydrophila-associated diarrhea.

The prevalence of Aeromonas hydrophila in stool specimens from patients with diarrhea was studied during 18 months. A. hydrophila was found in 1.1% of patients with diarrhea and in none of 533 control patients (P less than 0.02). Cases were detected 1.5 times more often during the summer months than the winter months, and most occurred in children less than 2 years of age. Clinical features included fever greater than 38 degrees C (55%), abdominal cramps (35%), vomiting (25%), and duration of illness greater than 10 days (50%). Detection of A. hydrophila in stools was facilitated by the use of sheep blood agar with 15 micrograms of ampicillin per ml which was flooded with oxidase reagent after growth. A cytotoxin was produced by 62% of the isolates, and the cytotoxic strains showed positive results in a hemolysin assay and a lysine decarboxylase reaction.     

How are different types of continuity achieved? A mixed methods longitudinal study

BACKGROUND: In the context of developments in healthcare services that emphasise swift access to care, concern has been expressed about whether and how continuity of care, particularly interpersonal continuity, will continue to be achieved. AIM: To explore how patients regard and use primary care services in relation to continuity of provider and access to care, to identify factors that promote or hinder their success in achieving their preferences, and to describe what this means for how different types of continuity are achieved. DESIGN OF STUDY: Longitudinal, mixed methods. SETTING: Community in London and Leicester. METHOD: Purposive sample of 31 patients recruited from general practices, walk-in centres and direct advertising. Data collection involved in-depth interviews, consultation record booklets completed over 6 months and general practice records for the year including the study period. Data were analysed qualitatively. RESULTS: Four patterns were identified in the way patients used primary care. These were shaped by their own preferences, by the organisation and culture of their primary care practices, and by their own and their provider's efforts to achieve their preferences. Different configurations of these factors gave rise to different types of continuity. Patients were not always able to achieve the type they wanted. Patients with apparently similar consulting patterns could experience them differently. CONCLUSION: Within a programme of modernisation, policies that promote a commitment to meeting the preferences of different patients with flexibility and understanding are most likely to provide continued support for interpersonal and other types of continuity of care.