Evolutionary dynamics of the human immunoglobulin kappa locus and the germline repertoire of the Vkappa genes

We have determined the entire nucleotide sequence of the human immunoglobulin kappa locus, comprising a total of 1,010,706 nucleotides. The 76 Vkappa genes found by a hybridization-based approach and their classification in 7 families were confirmed. A Vkappa orphon located near the locus was also sequenced. In addition, we identified 55 novel Vkappa relics and truncated pseudogenes, which establish 5 new families. Among these 132 Vkappa genes, 46 have open reading frames. According to the databases and the literature, 32 unique Vkappa genes and 5 identical gene pairs form VJ-joints, 27 unique genes and 4 gene pairs are transcribed, and 25 unique genes and 4 gene pairs produce functional proteins. The Vkappa gene locus contains a 360-kb inverted duplication, which harbors 118 Vkappa genes. A comparison of the duplicated Vkappa genes suggests positive selection on the complementarity-determining regions of the duplicated genes by point mutations. The entire duplication unit was divided into 13 blocks, each of which has its distinct nucleotide sequence identity to its duplication counterpart (98.1 - 99.9 %). An inversion-mediated mechanism is suggested to generate the high-homology blocks. Based on the homology blocks and the mutation rates, the inverted duplication is assumed to have taken place approximately 5 million years ago. An orphon Vkappa gene near the kappa locus and a cluster of five Vkappa orphons on chromosome 22 have no counterparts within the kappa locus. This suggests possible mechanisms of the transposition of orphon Vkappa genes.

Fluorescence bronchoscopy in the detection of preinvasive bronchial lesions in patients with sputum cytology suspicious or positive for malignancy

BACKGROUND

A new strategy in the treatment of squamous cell carcinoma of the tracheobronchial tree is the detection and eradication of preinvasive bronchial lesions before they become invasive cancers. It is, however, difficult to detect preinvasive lesions by conventional white-light bronchoscopy alone.

PURPOSE

we conducted a detailed investigation on the use of fluorescence bronchoscopy in the detection of preinvasive bronchial lesions in patients with sputum cytology suspicious or positive for malignancy.

METHODS

64 participants with sputum cytology suspicious or positive for malignancy were examined with both white light and fluorescence bronchoscopy (LIFE group). Earlier to this study, before fluorescence bronchoscopy became available in our institute, 48 participants having sputum cytology suspicious or positive for malignancy were examined with white light bronchoscopy alone (control group). Biopsy specimens for pathological examinations were taken of all abnormal areas discovered by white light or fluorescence bronchoscopy examination.

RESULTS

In sputum cytology suspicious or positive for malignancy, the diagnosis of preinvasive bronchial lesions was greatly enhanced in the LIFE group as compared with the control group (45 vs. 7 lesions). The percentage of participants with preinvasive bronchial lesions was also significantly higher in the LIFE group than in the control group (40.6 vs. 12.5%, P = 0.00087, respectively).

CONCLUSIONS

Our study suggests that the use of fluorescence bronchoscopy in addition to conventional white-light examination could greatly enhance the detection and localization of preinvasive bronchial lesions in patients with sputum cytology suspicious or positive for malignancy.

Change in mortality and years of life lost attributable to tobacco in Japan, 1985 and 1995

Despite the secular trend of decreasing prevalence of smoking and consumption of tobacco in most industrialized countries, the prevalence of smoking in Japan continues to be one of the highest. Based on the alternative measure of population attributable fractions, the present study gives an estimate of the number of deaths and the years of life lost (YLLs) attributable to tobacco in Japan for both 1985 and 1995. This study shows a considerable increase in mortality from tobacco-related diseases over the decade, in particular from lung cancer and chronic obstructive pulmonary disease, a consequence of the intensified exposure to tobacco in the early 1960s. Although the period of the highest exposure to tobacco was in the late 1970s, prevalence of smoking is still considerably high in Japan and the burden from tobacco will persist if proper anti-smoking measures are not implemented immediately.

Blood lysate staining, a new microscopic method for diagnosis of fungemia using peripheral blood

We developed a microscopy method for the detection of fungal cells in peripheral blood, termed blood lysate staining, using an approximately 5x5 mm dotted blood lysate. This method was able to detect the emerging fungal pathogen Trichosporon asahii in murine models of systemic fungal infection and fungemia in patients quickly and at minimal cost. Pathogenic yeasts were successfully detected in 6 of 8 blood samples which were taken from feverish immunocompromised patients who were clinically suspected of having fungal infections. Fungal cells were observed as ovoid to elongated, 3x3 to 7x10 microm, and occurred singly, budding, and in short chains and clusters in a periodic acid-Schiff-stained blood smear. The yeast cells were easily distinguished from blood-cell debris by their size, shape and smooth yet rigid outline.

Effects of PKC inhibitors on suppression of thermotolerance development in tsAF8 cells

Effects of protein kinase C (PKC) inhibitors (H7, staurosporine, calphostin C) on thermotolerance development were investigated in temperature sensitive tsAF8 cells derived from Syrian hamster BHK21 cells. Cells were pre-heated at 45 degrees C for 20 min, incubated at 34 degrees C with PKC inhibitors for varying lengths of time, i.e. 1.25-10.0 h, and then heated at 45 degrees C for 30 min. Increasing survival fractions after the second heat treatment was inhibited by the treatment with H7 (40-160 microM), with staurosporine (0.05-1.0 microM), and with calphostin C (0.8, 1.2 microM) in a concentration dependent manner. When the concentrations of these PKC inhibitors were low, the restraint of increasing survival fractions was temporary, since survival fractions increased 3-7.5 h after pre-heating. However, the survival fractions were almost constant by the treatment with 160 microM H7 and 1.0 microM staurosporine. Induction of HSP72 after heat stress was investigated in tsAF8 and BHK21 cells. Cells were heated at 45 degrees C for 20 min and incubated at 34 or 39.7 degrees C (tsAF8), at 37 degrees C (BHK21). Intensity of intracellular fluorescence from HSP72 was measured by flow cytometry. HSP72 was induced in BHK21 cells, but there was no definite induction of HSP72 in tsAF8 cells at either 39.7 or 34 degrees C. These results suggest that PKC is related with the thermotolerance development in tsAF8 cells; however, HSP72 is not involved in the thermotolerance development in tsAF8 cells.

A physical map of the human genome

The human genome is by far the largest genome to be sequenced, and its size and complexity present many challenges for sequence assembly. The International Human Genome Sequencing Consortium constructed a map of the whole genome to enable the selection of clones for sequencing and for the accurate assembly of the genome sequence. Here we report the construction of the whole-genome bacterial artificial chromosome (BAC) map and its integration with previous landmark maps and information from mapping efforts focused on specific chromosomal regions. We also describe the integration of sequence data with the map.

Isolation and characterization of the UBASH3A gene on 21q22.3 encoding a potential nuclear protein with a novel combination of domains

In order to identify candidate genes for Down syndrome phenotypes or monogenic disorders that map to human chromosome 21q22.3, we have used genomic sequence and expressed sequence tags mapping to an autosomal recessive deafness (DFNB10) critical region to isolate a novel 2.5-kb cDNA that maps between TFF1 and D21S49. A semi-quantitative reverse transcription/polymerase chain reaction method revealed that UBASH3A gene expression is limited to only a few tissues, with its highest expression in spleen, peripheral blood leukocytes, and bone marrow. The putative 661-amino-acid protein shows considerable homology to a hypothetical protein from Drosophila melanogaster but only domain homologies to other organisms. Both the human and D. melanogaster proteins contain protein-protein interaction domains, viz., SH3 and ubiquitin-associated (UBA) domains, in addition to a novel domain also containing a nuclear localization signal. This is the first protein described containing both UBA and SH3 domains. The gene, thus called UBASH3A, spans 40 kb and is divided into 15 exons. Mutation analysis excluded UBASH3A as being responsible for DFNB10.

The effects of KNK437, a novel inhibitor of heat shock protein synthesis, on the acquisition of thermotolerance in a murine transplantable tumor in vivo

A newly synthesized reagent, KNK437, has been found specifically to inhibit the synthesis of heat shock proteins in vitro. In this study, we investigated the effects of KNK437 on the synthesis of heat shock proteins and the induction of thermotolerance in transplantable tumors in vivo. SCC VII cells were grown in vivo and transplanted into C3H/He mice. The concentrations of KNK437 in the tumors and the sera of the mice were examined by high-performance liquid chromatography. Hsp72 synthesis was examined by Western immunoblot analysis. The response to hyperthermia was evaluated in terms of the delay in tumor growth. KNK437 had low toxicity in vivo. The concentration of KNK437 in the tumors gradually increased and reached a peak 6 h after i.p. injection. Hsp72 were synthesized 8 h after hyperthermia at 44 degrees C for 10 min, and their synthesis was inhibited by administration of KNK437 6 h before hyperthermia. At a concentration of 200 mg/kg, KNK437 alone showed no antitumor effects and did not increase the thermosensitivity of nontolerant tumors. The same dose of KNK437 enhanced the antitumor effects of fractionated heat treatment at 44 degrees C in a synergistic manner. This study strongly suggests the inhibition of thermotolerance via the inhibition of HSP72 in vivo. The inhibition of thermotolerance by KNK437 may help to improve the efficacy of clinical fractionated hyperthermia.

Insertion of beta-satellite repeats identifies a transmembrane protease causing both congenital and childhood onset autosomal recessive deafness

Approximately 50% of childhood deafness is caused by mutations in specific genes. Autosomal recessive loci account for approximately 80% of nonsyndromic genetic deafness. Here we report the identification of a new transmembrane serine protease (TMPRSS3; also known as ECHOS1) expressed in many tissues, including fetal cochlea, which is mutated in the families used to describe both the DFNB10 and DFNB8 loci. An 8-bp deletion and insertion of 18 monomeric (approximately 68-bp) beta-satellite repeat units, normally present in tandem arrays of up to several hundred kilobases on the short arms of acrocentric chromosomes, causes congenital deafness (DFNB10). A mutation in a splice-acceptor site, resulting in a 4-bp insertion in the mRNA and a frameshift, was detected in childhood onset deafness (DFNB8). This is the first description of beta-satellite insertion into an active gene resulting in a pathogenic state, and the first description of a protease involved in hearing loss.

[Gene therapy for the treatment of hypertension]

Gene therapy for hypertension is very important for the next generation of antihypertensive drugs. Important question regarding vector-related limitations and suboptimal in vivo delivery systems will require expeditious attention for gene therapy to become a more widely applicable option in cardiovascular diseases including hypertension. However, the elucidation of molecular mechanisms of transcriptional activation of several important genes in the cardiovascular physiology enables us to develop clinical application of gene therapy for hypertension at the level of transcription factors. Recent studies showed that in vivo or ex vivo transfection of double-stranded oligodeoxynucleotides to block the binding of nuclear factors to specific cis-elements in the promoter regions of several genes resulted in inhibition of gene trans-activation and suppressed pathological changes in the cardiovascular system.

Cloning and characterization of a putative human glycerol 3-phosphate permease gene (SLC37A1 or G3PP) on 21q22.3: mutation analysis in two candidate phenotypes, DFNB10 and a glycerol kinase deficiency

Using multiple exons trapped from human chromosome 21 (HC21)-specific cosmids with homology to a putative Arabidopsis thaliana glycerol 3-phosphate permease, we have determined the full-length cDNA sequence of a novel HC21 gene encoding a putative sugar-phosphate transporter (HGMW-approved symbol SLC37A1, aka G3PP). The predicted protein has 12 putative transmembrane domains and is also highly homologous to bacterial glpT proteins. The transcript was precisely mapped to 21q22.3 between D21S49 and D21S113. Comparison of the SLC37A1 cDNA to genomic sequence revealed that the gene encompasses 82 kb, and it is split into 19 coding exons and 7 untranslated exons, which are alternatively spliced in a complex and tissue-specific manner. Glycerol 3-phosphate (G3P) is produced by glycerol kinase (GK) and is found in several biochemical pathways in different cellular compartments, such as the glycerol phosphate shuttle and glycerophospholipid synthesis. Thus SLC37A1 mutations may cause a phenotype similar to GK deficiency. Mutational analyses of SLC37A1 in seven patients with no mutations in the GK gene and low GK activity revealed only nonpathogenetic sequence variants, excluding SLC37A1 as the gene for the phenotype in these patients. SLC37A1 maps in the refined critical region of the autosomal recessive deafness locus, DFNB10, on 21q22.3. Mutation analyses also excluded SLC37A1 as the gene for DFNB10.

[Application of cost-effectiveness analysis of health care interventions in developing countries. A case study in Mauritius]

OBJECTIVE

Cost-effectiveness analysis is a tool to help inform the decision maker of efficient allocation of scarce health care resources and its application has increased in developing countries during the past decade. There are, however, a variety of different approaches used to calculate cost-effectiveness ratios, given the range and the controversies surrounding the use of some components of total cost, depending on the constraints faced by various decision-making bodies. This study is an investigation of cost-effectiveness of both currently delivered and prospective health interventions in Mauritius to set priorities and assess allocative efficiency by taking into account such constraints.

METHODS

Resource use and unit cost data were collected from the representative health facilities and the Ministry of Health to estimate costs of each health intervention per person. Effectiveness of each intervention was estimated from the results of the national burden of disease study and the efficacy database compiled for this exercise. Several types of cost-effectiveness were calculated for each intervention according to its characteristics and the constraints imposed by the existing infrastructures and other health interventions.

RESULTS

Cost-effectiveness ratios with and without the decision maker's constraints differed significantly. Infrastructure-constrained average cost-effectiveness of thirteen currently delivered and twenty one prospective interventions ranged from $127 to $92,949 and from $77 to $66,302 per DALY averted, respectively. Incremental cost-effectiveness of the prospective interventions was from $83 to $70,553. Among the currently delivered interventions, those for perinatal disorders, mental illness, and ischemic heart disease were particularly less cost-effective than the prospective interventions. Sensitivity analysis of both effectiveness and discount rates did not change the cost-effectiveness ranking significantly.

CONCLUSION

The present study showed that cost-effectiveness ratios differ significantly depending on the decision maker's constraints and that an interpretation of each cost-effectiveness study should be made with great caution when implementing its results in practice. Both average cost-effectiveness of the currently delivered interventions and incremental cost-effectiveness of the prospective interventions suggest that there is an allocative inefficiency among the currently delivered health interventions in Mauritius and a possibility of enhancing allocative efficiency through introducing alternative interventions.

Jet-Cooled Optical Spectroscopy of FeN between 16 300 and 21 600 cm(-1)

We report the first gas-phase spectroscopic study of iron mononitride (FeN). FeN molecules were generated by the reaction of laser-ablated Fe atoms with NH(3) under supersonic jet-cooled conditions. Laser-induced fluorescence excitation spectra were measured between 16 300 and 21 600 cm(-1), and rotational analyses have been performed for about 25 vibronic bands. The Omega value of the ground state has been determined to be 52, which could be the spin-orbit component of (2)Delta (ellipsis 1delta(3)9varsigma(2)) or (4)Pi (ellipsis 1delta(3)9varsigma(1)4pi(1)). The excited states in the visible absorption region show very complicated rovibronic structures due to heavy perturbations. Excited state lifetimes, (56)Fe(14)N/(56)Fe(15)N isotope shifts, and dispersed fluorescence spectra were measured for the majority of the bands, which were classified into the five Omega = 52-XOmega = 52 band systems. Copyright 2000 Academic Press.

Role of the gynoecium in natural senescence of carnation (Dianthus caryophyllus L.) flowers

Although the role of the gynoecium in natural senescence of the carnation flower has long been suggested, it has remained a matter of dispute because petal senescence in the cut carnation flower was not delayed by the removal of gynoecium. In this study, the gynoecium was snapped off by hand, in contrast to previous investigations where removal was achieved by forceps or scissors. The removal of the gynoecium by hand prevented the onset of ethylene production and prolonged the vase life of the flower, demonstrating a decisive role of the gynoecium in controlling natural senescence of the carnation flower. Abscisic acid (ABA) and indole-3-acetic acid (IAA), which induced ethylene production and accelerated petal senescence in carnation flowers, did not stimulate ethylene production in the flowers with gynoecia removed (-Gyn flowers). Application of 1-aminocyclopropane-1-carboxylate (ACC), the ethylene precursor, induced substantial ethylene production and petal wilting in the flowers with gynoecia left intact, but was less effective at stimulating ethylene production in the -Gyn flowers and negligible petal in-rolling was observed. Exogenous ethylene induced autocatalytic production of the gas and petal wilting in the -Gyn flowers. These results indicated that ethylene generated in the gynoecium triggers the onset of ethylene production in the petals of carnation during natural senescence.

Fc alpha/mu receptor mediates endocytosis of IgM-coated microbes

IgM is the first antibody to be produced in a humoral immune response and plays an important role in the primary stages of immunity. Here we describe a mouse Fc receptor, designated Fc alpha/microR, and its human homolog, that bind both IgM and IgA with intermediate or high affinity. Fc alpha/microR is constitutively expressed on the majority of B lymphocytes and macrophages. Cross-linking Fc alpha/microR expressed on a pro-B cell line Ba/F3 transfectant with soluble IgM or IgM-coated microparticles induced internalization of the receptor. Fc alpha/microR also mediated primary B lymphocyte endocytosis of IgM-coated Staphylococcus aureus. Thus, Fc alpha/microR is involved in the primary stages of the immune response to microbes.

The spatial separation of the poor in Canadian cities

We used the 1991 Canadian census to examine the extent of spatial separation of the poor in Canadian cities. Although there were no extensive areas of blight, decay, or housing abandonment, we found high spatial separation of poor visible minorities in the selected cities. The index of dissimilarity indicates high segregation of poor blacks and moderate separation of poor Asians from the nonpoor population. We tested the effects of three major structural factors--racial and ethnic segregation, income segregation, and urban redevelopment--and found that racial and ethnic residential patterns are related strongly to the spatial separation of poor persons. The relationship between income segregation and spatial separation of the poor is not significant, however. We also found that the relationship between urban redevelopment and spatial separation of the poor pertains only to blacks. These findings suggest that blacks are vulnerable in the process of urban redevelopment.

Asymmetrical temporal lobe atrophy with massive neuronal inclusions in multiple system atrophy

This report concerns a rare association of asymmetrical temporal lobe atrophy with multiple system atrophy (MSA). A 53-year-old Japanese woman developed cerebellar ataxia and parkinsonism and was diagnosed as olivopontocerebellar atrophy (OPCA). This patient showed forgetfulness and subsequent disorientation even in the early stage of the disease. She fell into a decorticate state at the age of 64, and died a year later. The autopsy showed MSA with asymmetrical atrophy of temporal lobes, intraneuronal globular inclusions mostly confined to the hippocampus, amygdaloid nucleus, and most abundant in the granule cells in the dentate fascia. These inclusions were intensely argyrophilic and expressed marked immunoreactivity to ubiquitin, but not to neurofilament (NF), tau and paired helical filaments (PHF). Ultrastructurally, they were composed of scattered short filamentous structures of 15 to 30 nm in diameter, ribosome-like granules, mitochondria and lipofuscin. The lack of immunoreactivity against tau, NF and PHF suggests that the inclusions are distinct from Pick bodies. To our knowledge, MSA in association with asymmetrical temporal lobe atrophy with the present neuronal inclusions has not been reported. This case is distinct from MSA combined with atypical Pick's disease in the distribution and immunohistochemical properties of neuronal inclusions, and may present a new variant of MSA since the neuronal inclusions are similar, in many respects, to those of neuronal inclusions reported in MSA. Globular inclusions are also discussed in variants of Pick's disease, amyotrophic lateral sclerosis and Alzheimer's disease.

[Effect of the level of basic activities of daily living on home caregiver burnout]

To relieve the stress of caregivers, it is critical to identify and classify the burden factors in the elderly patients. In order to determine the factors that exhaust caregivers, a cross sectional survey was done. The study employed a self-recording questionnaire form which included the Pines' burnout scale and the level of patient's basic activities of daily living (BADL). Seventy-three caregivers filled in the questionnaire. They reported the difficulty of care for an elderly patient in the home, and the degree of the difficulty correlated well with the burnout score (r = -0.517; p < 0.001). The caregivers' burnout score did not correlate so well with the level of their patient's BADL (r = -307; p = 0.014). Among the factors in BADL, aid for toilet use, feeding, sitting, and transferring raised the burnout scale. On the other hand, assistance for bathing and dressing did not correlate with the burnout score. On multiple regression analysis using the background factors for the burnout score as explanatory variables, aid for feeding and sitting were significant independent contributing factors. Since it became clear that the caregivers in the home were almost burnt out owing to the aid they need to give for the elderly person's BADL, attempts should be done to reduce their burden as soon as possible.

Expression of genes responsible for ethylene production and wilting are differently regulated in carnation (Dianthus caryophyllus L.) petals

Carnation petals exhibit autocatalytic ethylene production and wilting during senescence. The autocatalytic ethylene production is caused by the expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase and ACC oxidase genes, whereas the wilting of petals is related to the expression of the cysteine proteinase (CPase) gene. So far, it has been believed that the ethylene production and wilting are regulated in concert in senescing carnation petals, since the two events occurred closely in parallel with time. In the present study, we investigated the expression of these genes in petals of a transgenic carnation harboring a sense ACC oxidase transgene and in petals of carnation flowers treated with 1,1-dimethyl-4-(phenylsulfonyl)semicarbazide (DPSS). In petals of the transgenic carnation flowers, treatment with exogenous ethylene caused accumulation of the transcript for CPase and in-rolling (wilting), whereas it caused no or little accumulation of the transcripts for ACC oxidase and ACC synthase and negligible ethylene production. In petals of the flowers treated with DPSS, the transcripts for ACC synthase and ACC oxidase were accumulated, but no significant change in the level of the transcript for CPase was observed. These results suggest that the expression of ACC synthase and ACC oxidase genes, which leads to ethylene production, is differentially regulated from the expression of CPase, which leads to wilting, in carnation petals.

Inhibition of thermotolerance observed on tsAF8 cells

The characteristic development of thermotolerance was examined in tsAF8 cells, which were temperature sensitive cell line derived from BHK21. tsAF8 cells lose RNA polymerase II activity and arrest in the G1 phase of the cell cycle at the nonpermissive temperature of 39.5-40.6 degrees C. tsAF8 cells were pre-heated at 45 degrees C for 20 min, incubated at 34 or 39.7 degrees C for different durations, and then heated again at 45 degrees C for 30 min. The cells were trypsinized immediately after the second heating to evaluate cell survival. As a result, thermotolerance was developed rapidly in the cells incubated at 34 degrees C. However, the survival rate of the cells incubated at 39.7 degrees C was almost constant. Thermotolerance of BHK21 cells, which were wild-type cells of tsAF8 cells, developed at 39.7 degrees C. These results suggest that thermotolerance may be inhibited in tsAF8 cells incubated at 39.7 degrees C, and that some metabolism which is inhibited in tsAF8 cells at 39.7 degrees C may be related to thermotolerance development.