Severe congenital neutropenia: clinical effects and neutrophil function during treatment with granulocyte colony-stimulating factor

We studied neutrophil function and clinical responses in seven patients with severe congenital neutropenia (SCN) after they received treatment with recombinant human granulocyte colony stimulating factor (rhG-CSF). Two subpopulations of patients with SCN were defined by their pattern of absolute neutrophil response, superoxide production, and cytochrome b559 levels. One group had an oscillating absolute neutrophil count and reduced ability to produce superoxide and cytochrome b559 (n = 4), and the second group had a relatively constant absolute neutrophil count response with normal superoxide and cytochrome levels (n = 3). Neutrophils from both groups had decreased surface expression of FcRIII and abnormal upregulation of the C3bi receptor (CR3). All patient neutrophils, however, had normal contents of the primary granule constituent, beta-glucuronidase, and the specific granule constituent, vitamin B 12 binding protein. The clinical response to rhG-CSF was evident by marked improvement in the degree of periodontitis and reduction in the number of oral ulcers in both groups of patients. Although neutrophil function is not completely normal in patients with SCN, it is likely that enough redundancy exists in neutrophil bactericidal capacity to promote normal host response to inflammation.

Insulin-dependent diabetes mellitus: applications of health records for understanding etiology. The Pittsburgh IDDM Registry Group

The estimation of incidence (or risk) of disease depends on accurate and complete reporting of new cases and precise estimation of the population at risk. Therefore, incidence studies are often based on population-based incidence registries. A critical problem in diabetes research, however, has been the lack of adequate population-based data. For diseases that have a distinct and rapid onset, the best method of obtaining population-based data is to develop registries of community health information. These disease registries form an important tool for assessing the clinical course of diseases and can lead to an understanding of their etiology and pathogenesis. Moreover, by facilitating identification of cases, disease registries can serve as a population source for genetic and immunological testing, the results of which can be directly related to absolute risk. Evaluation of factors associated with a disease can suggest methods for reducing its incidence and even lead to its eradication. Such registries also permit the evaluation of existing or proposed health care measures. Registry information can rapidly be communicated to the local area health authorities to assist in altering patterns of care. Registries are therefore important for understanding the etiology and complications of chronic diseases as well as for evaluation of medical care in populations. For diabetes, and in particular, insulin-dependent diabetes, the development and comparison of registries in diverse populations worldwide may be more important than for other diseases. A major reason for developing them is that the disease is very costly both for patients and society.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of chromosome 18 and X centric heterochromatin in the interphase nucleus of cultured human cells

In situ hybridization of human chromosome 18 and X-specific alphoid DNA-probes was performed in combination with three dimensional (3D) and two dimensional (2D) image analysis to study the interphase distribution of the centric heterochromatin (18c and Xc) of these chromosomes in cultured human cells. 3D analyses of 18c targets using confocal laser scanning microscopy indicated a nonrandom disposition in 73 amniotic fluid cell nuclei. The shape of these nuclei resembled rather flat cylinders or ellipsoids and targets were preferentially arranged in a domain around the nuclear center, but close to or associated with the nuclear envelope. Within this domain, however, positionings of the two targets occurred independently from each other, i.e., the two targets were observed with similar frequencies at the same (upper or lower) side of the nuclear envelope as those on opposite sides. This result strongly argues against any permanent homologous association of 18c. A 2D analytical approach was used for the rapid evaluation of 18c positions in over 4000 interphase nuclei from normal male and female individuals, as well as individuals with trisomy 18 and Bloom's syndrome. In addition to epithelially derived amniotic fluid cells, investigated cell types included in vitro cultivated fibroblastoid cells established from fetal lung tissue and skin-derived fibroblasts. In agreement with the above 3D observations 18c targets were found significantly closer (P less than 0.01) to the center of the 2D nuclear image (CNI) and to each other in all these cultures compared to a random distribution derived from corresponding ellipsoid or cylinder model nuclei. For comparison, a chromosome X-specific alphoid DNA probe was used to investigate the 2D distribution of chromosome X centric heterochromatin in the same cell types. Two dimensional Xc-Xc and Xc-CNI distances fit a random distribution in diploid normal and Bloom's syndrome nuclei, as well as in nuclei with trisomy X. The different distributions of 18c and Xc targets were confirmed by the simultaneous staining of these targets in different colors within individual nuclei using a double in situ hybridization approach.

Double in situ hybridization in combination with digital image analysis: a new approach to study interphase chromosome topography

Double in situ hybridization with mercurated and biotinylated chromosome specific DNA probes in combination with digital image analysis provides a new approach to compare the distribution of homologous and nonhomologous chromosome targets within individual interphase nuclei. Here we have used two DNA probes representing tandemly repeated sequences specific for the constitutive heterochromatin of the human chromosomes 1 and 15, respectively, and studied the relative arrangements of these chromosome targets in interphase nuclei of human lymphocytes, amniotic fluid cells, and fibroblasts, cultivated in vitro. We have developed a 2D-image analysis approach which allows the rapid evaluation of large numbers of interphase nuclei. Models to test for a random versus nonrandom distribution of chromosome segments are discussed taking into account the three-dimensional origin of the evaluated 2D-distribution. In all three human diploid cell types the measurements of target-target and target-center distances in the 2D-nuclear image revealed that the labeled segments of the two chromosomes 15 were distributed both significantly closer to each other and closer to the center of the nuclear image than the labeled chromosome 1 segments. This result can be explained by the association of nucleolus organizer regions on the short arm of chromosome 15 with nucleoli located more centrally in these nuclei and does not provide evidence for a homologous association per se. In contrast, evaluation of the interphase positioning of the two chromosome 1 segments fits the random expectation in amniotic fluid and fibroblast cells, while in experiments using lymphocytes a slight excess of larger distances between these homologous targets was occasionally observed. 2D-distances between the labeled chromosome 1 and 15 segments showed a large variability in their relative positioning. In conclusion our data do not support the idea of a strict and permanent association of these homologous and nonhomologous targets in the cell types studied so far.