We discuss the practical and clinical considerations encountered when planning a Phase IIa trial in chronic obstructive pulmonary disease (COPD). Various adaptive strategies for reducing the cost of the trial and the statistical implications of these are explored. Use of the EAST software to evaluate the properties of the study designs with one or more interim analyses for futility, efficacy or either is described. We emphasize the rationale for choosing between alternative designs and the relationship between the clinical and statistical considerations.

Clinical Trials, Phase II as Topic↗

PubMedDate not supplied

Numerical chromosomal abnormalities detected by atomic force microscopy.

The numerical abnormalities of human metaphase chromosomes, fixed according to standard procedures for optical microscopy but not treated for banding, were detected by atomic force microscopy (AFM). High-resolution AFM imaging of chromosomes in trisomy 13, 21, and Klinefelter syndrome can be compared directly with the traditional optical image. The unbanded metaphase chromosomes, including the extra ones in trisomic patients showed a structural pattern very similar to G-banding. Comparison of AFM images with light microscopic data allows the identification of specific chromosomes, and images of chromosomes showing numerical and structural abnormalities can then be analysed.

Chromosome Aberrations↗

PubMedDate not supplied

The mechanism of G-banding detected by atomic force microscopy.

The morphologic changes occurring in human chromosomes during G-banding by trypsin treatment on the same metaphase were followed with the aid of an atomic force microscope (AFM). It was found that trypsin treatment alone caused a pattern of collapse in the chromosomes that was clearly dependent on the duration of trypsinization. The progressive pattern of collapse first indicated the loss of internal differentiation between chromatids, then bands, and finally all internal structures, except for edges running around the chromosomes' perimeter. When stained with Giemsa, the collapsed chromosomes partly regained their original form, and transverse ridges appeared that correspond to G-positive band regions. However, the treatment of fixed chromosomes with trypsin for 42 s diminished the chromosomal edges, and the z-dimensions could not be measured even with the subsequent application of Giemsa.

Chromosome Banding↗

PubMedDate not supplied

C-banding visualized by atomic force microscopy.

C-banding is a method used for studying chromosome rearrangements near centromeres and for investigating polymorphisms. In human chromosomes, the C-bands are located at the centromere of all the chromosomes and the distal long arm of the Y chromosome. In this study, we aimed to detect the structural changes in chromosomes during the stages of C-banding by atomic force microscopy. We observed crater-like structures in the chromosomes after 2xSSC (saline sodium citrate) treatment and measured the relative difference between the heights of chromatid and centromere of the chromosomes. Results showed that the relative difference was 3 nm in chromosomes 1, 9, 16, and Y, whereas in the other chromosomes this value was 11.6 nm. After Giemsa staining, the relative difference increased by a factor of 16 in chromosomes 1, 9, 16, and Y. The other chromosomes showed no such increase, which is in accordance with our suggestion that nonhiston proteins associated with DNA in constitutive heterochromatin can make the constitutive heterochromatin resistant to C-banding.

Azure Stains↗

PubMedDate not supplied

Schistosomiasis japonica on Jishan Island, Jiangxi Province, People's Republic of China: persistence of hepatic fibrosis after reduction of the prevalence of infection with age.

Hepatic fibrosis due to schistosomiasis japonica was examined by ultrasonography in a cross-sectional community study of 825 individuals on Jishan Island, Jiangxi Province, China. The prevalence of active infection was 39.4% with peak infection in the 10-19.9 years age group followed by a significant decline. A similar pattern was observed for intensity of infection. The prevalence of hepatomegaly in the midsternal line > or = 6 cm peaked at 60% in the fourth decade and remained elevated. A progressive increase in the severity of hepatic periportal fibrosis was observed with age, with advanced fibrosis peaking in the fifth decade. The proportion of individuals with advanced fibrosis was significantly greater in males than in females despite equivalent prevalence and intensity of schistosome infection. In addition, a positive association (P < 0.01) was found between periportal fibrosis and both hepatomegaly > or = 6 cm and splenomegaly. This study suggests that the natural history of schistosomiasis japonica in this hyperendemic community in China is marked by persistence of hepatomegaly and schistosome-induced periportal fibrosis in adults despite a decrease in the prevalence of infection.

Adolescent↗

PubMedDate not supplied

Characteristics of male medical patients referred for alcoholism treatment.

PURPOSE: Medically ill alcoholics are frequently encountered in medical practice, yet little is known about this subgroup of alcoholics. Anecdotal evidence suggests that current treatment methods may be ineffective in some of these patients, and that many of them resist referral to treatment programs. In this pilot study, we sought to characterize this group, in order to determine whether further research was indicated. BASIC PROCEDURES: In the Minneapolis VA Medical Center, we conducted a retrospective chart review of 61 alcoholics from 3 groups of alcohol-dependent patients: medical inpatients who accepted transfer to treatment, medical inpatients who refused transfer, and ambulatory patients requesting treatment. The groups were compared on demographic, physical, psychological, and laboratory characteristics, and on compliance with medical appointments. Most Important Findings: As might be expected, inpatients were older and sicker than ambulatory patients, but also demonstrated fewer nonmedical complications of alcoholism. On psychological testing, those who transferred were more likely to exhibit anxiety and depression, while the ambulatory patients were more antisocial. Inpatients who transferred differed from those who refused in having fewer previous treatments and less severe medical illness and in showing more compliance with medical recommendations in general. PRINCIPAL CONCLUSIONS: These findings raise the possibility that these groups may significantly differ from one another, and suggest that further research on the characteristics of medically ill alcoholics is indicated. Improved characterization could potentially lead to more effective treatment approaches.

Adult↗

PubMedDate not supplied

Profile and outcome of childhood mycosis fungoides in Singapore.

Mycosis fungoides (MF) is the most common form of cutaneous T-cell lymphoma. It usually occurs in middle-aged and elderly persons, although several reports have described its occurrence in young children. The aim of this study was to review the profile and outcome of childhood MF in Singapore from 1989 to 1998. A total of nine patients (six males and three females) were diagnosed with MF before the age of 21 years. There were four Chinese, four Malay, and one Indian. The age at the time of histologic diagnosis ranged from 6 to 20 years (mean 14.3 years). Eight of the nine patients presented with hypopigmented patches and plaques. According to TNM staging, three were in stage 1A and six in stage 1B. The treatment modalities included psoralen plus ultraviolet A (PUVA) (n = 5), UVB (n = 2), and potent topical steroids (n = 2). We found that PUVA induced a faster clinical remission, but maintenance PUVA was required to prolong the relapse-free interval. This study also highlighted the need to consider MF in the differential diagnosis of hypopigmented dermatoses in dark-skinned individuals, especially if they occur on the buttocks.

Administration, Topical↗

PubMedDate not supplied

What syndrome is this? Hidrotic ectodermal dysplasia (Clouston syndrome).

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Adult↗