Orthostatic hypotension in pediatrics

Transient orthostatic hypotension is a common experience of many healthy adolescents and is the expected outcome of relatively dilated-dependent vascular tone. These children may experience brief symptoms of orthostatic intolerance when standing up rapidly, but they have no chronic symptoms or diseases. However, persistent orthostatic hypotension and chronic symptoms of orthostatic intolerance indicate postural tachycardia syndrome.     

Randomized trial evaluating a new 0.5% fluorouracil formulation demonstrates efficacy after 1-, 2-, or 4-week treatment in patients with actinic keratosis

The efficacy and safety of a new 0.5% fluorouracil topical cream were compared with vehicle control for the treatment of actinic keratosis (AK). Active treatment applied once daily for 1, 2, or 4 weeks was more effective than vehicle control in achieving reduction from baseline in lesion counts and lesion clearance. Active treatment also resulted in significantly better global assessments of overall improvement. Treatment was effective regardless of the number of baseline lesions. Although longer treatment duration correlated with greater efficacy, treatment for 1, 2, or 4 weeks was effective. This new microsphere-based fluorouracil formulation was generally well tolerated; adverse events were primarily limited to facial irritation that resolved quickly after treatment. This new treatment provides a safe alternative to the topical fluorouracil formulations currently available for the 1-, 2-, or 4-week treatment of AK.     

A genome-wide scan for linkage to chromosomal regions in 382 sibling pairs with schizophrenia or schizoaffective disorder

OBJECTIVE: Some genome-wide scans and association studies for schizophrenia susceptibility genes have yielded significant positive findings, but there is disagreement between studies on their locations, and no mutation has yet been found in any gene. Since schizophrenia is a complex disorder, a study with sufficient power to detect a locus with a small or moderate gene effect is necessary. METHOD: In a genome-wide scan of 382 sibling pairs with a diagnosis of schizophrenia or schizoaffective disorder, 396 highly polymorphic markers spaced approximately 10 centimorgans apart throughout the genome were genotyped in all individuals. Multipoint nonparametric linkage analysis was performed to evaluate regions of the genome demonstrating increased allele sharing, as measured by a lod score. RESULTS: Two regions with multipoint maximum lod scores suggesting linkage were found. The highest lod scores occurred on chromosome 10p15-p13 (peak lod score of 3.60 at marker D10S189) and the centromeric region of chromosome 2 (peak lod score of 2.99 at marker D2S139). In addition, a maximum lod score of 2.00 was observed with marker D22S283 on chromosome 22q12, which showed evidence of an imprinting effect, whereby an excess sharing of maternal, but not paternal, alleles was present. No evidence of linkage was obtained at several locations identified in previous studies, including chromosomes 1q, 4p, 5p-q, 6p, 8p, 13q, 15p, and 18p. CONCLUSIONS: The findings of this large genome-wide scan emphasize the weakness and fragility of linkage reports on schizophrenia. No linkage appears to be consistently replicable across large studies. Thus, it has to be questioned whether the genetic contribution to this disorder is detectable by these strategies and the possibility raised that it may be epigenetic, i.e., related to gene expression rather than sequence variation. Nevertheless, the positive findings on chromosome 2, 10, and 22 should be pursued further.     

HVI and HVII mitochondrial DNA data in Apaches and Navajos

Most mtDNA studies on Native Americans have concentrated on hypervariable region I (HVI) sequence data. Mitochondrial DNA haplotype data from hypervariable regions I and II (HVI and HVII) have been compiled from Apaches (N=180) and Navajos (N=146). The inclusion of HVII data increases the amount of information that can be obtained from low diversity population groups. Less mtDNA variation was observed in the Apaches and Navajos than in major population groups. The majority of the mtDNA sequences were observed more than once; only 17.8% (32/180) of the Apache sequences and 25.8% of the Navajo sequences were observed once. Most of the haplotypes in Apaches and Navajos fall into the A and B haplogroups. Although a limited number of haplogroups were observed, both sample populations exhibit sufficient variation for forensic mtDNA typing. Genetic diversity was 0.930 in the Apache sample and 0.963 in the Navajo sample. The random match probability was 7.48% in the Apache sample and 4.40% in the Navajo sample. The average number of nucleotide differences between individuals in a database is 9.0 in the Navajo sample and 7.7 in the Apache sample. The data demonstrate that mtDNA sequencing can be informative in forensic cases where Native American population data are used.     

Patients' views of the burden of asthma: a qualitative study

OBJECTIVES: To explore the burden of asthma on the lives of people presenting to hospital emergency departments for asthma treatment. DESIGN: A qualitative study. Consenting individuals with asthma who presented to emergency departments were interviewed in-depth, and interviews were taped, transcribed and thematically analysed. Questionnaire data on medication use, respiratory health and asthma knowledge were also collected. Asthma severity was determined from the medical records. SETTING: A tertiary teaching hospital and a suburban hospital during March and April 2000, and a rural hospital during July and August 2000. PARTICIPANTS: Sixty-two participants (19 male and 43 female), aged 18-70 years. RESULTS: The burden of asthma was broad, affecting social life, personal relationships, employment and finances. The cost of asthma medication was an issue for nearly two-thirds of participants. Individuals performed their own "cost-benefit analysis" for medication use, weighing up expense, perceived side effects and potential benefits. As a consequence, several participants chose to alter their medication dose, or not to take prescribed medications. For some participants, asthma directly contributed to diminished employment opportunities. CONCLUSIONS: To achieve a therapeutic partnership, doctors need to be aware of the substantial social, personal and financial burden of asthma for their patients. They should also recognise that patients' perceptions of treatment cost may compromise treatment adherence.     

Local and systemic effects of intra-arterial desmopressin in healthy volunteers and patients with type 3 von Willebrand disease. Role of interleukin-6

Intra-arterial desmopressin caused dose and time dependent increases (p <0.001 for all) in forearm blood flow (all doses) and plasma tissue plasminogen activator (t-PA) concentrations (desmopressin > or = 70 ng/min). Although plasma t-PA concentrations rose in both forearms, there was a modest local release of t-PA in the infused forearm (14 ng/100 mL of tissue/min, p <0.05). At desmopressin doses > or = 300 ng/min, plasma von Willebrand factor (vWf) and Factor VIII:C concentrations rose in both forearms (p <0.001) and correlated with the rise in interleukin-6 concentrations (r = 0.92, p <0.001: r = 0.85, p = 0.002 respectively). Neither desmopressin nor substance P caused t-PA, vWf or Factor VIII:C release in the patients, although desmopressin increased plasma interleukin-6 concentrations as in healthy volunteers. We conclude that desmopressin releases t-PA, vWf and Factor VIII:C predominantly via systemic mechanisms, possibly mediated by cytokine release. Patients with type 3 vWD appear to have a generalised failure to release t-PA acutely despite a normal interleukin-6 response to desmopressin infusion.     

Gender as a health determinant and implications for health education.

Gender is a health determinant, but gender itself is influenced, in part, by biological and psychological variables. Understanding gender's influence on health therefore requires an understanding of the determinants of the construct gender. A review of certain gender determinants is presented. The authors consider the modifiability of these determinants and present recommendations about which of these determinants should be targeted for health promotion and policy creation activities. In concluding, they argue that gender is a multidetermined construct that encompasses many factors that may be modifiable through intervention, and consideration of all of these factors should be vigorously pursued.