Effect of melatonin on circadian rhythm, locomotor activity and body temperature in the intact house sparrow, Japanese quail and owl

We compared the effect of melatonin on circadian rhythm, body temperature, and locomotion in the intact house sparrow, Japanese quail and owl. Daily treatment with melatonin at a fixed time did not entrain the free-running rhythm of locomotor activity in the house sparrow and the disrupted rhythm in Japanese quail under constant dim light. However, melatonin clearly inhibited movement for several hours after treatment. The duration of resting after injection of melatonin was dose-dependent. Body temperature was significantly decreased after melatonin treatment, the effect being more potent during the active phase than in the resting phase. Although this effect of melatonin on body temperature was also dose-dependent, the magnitude of the decrease in body temperature after injection of melatonin was greater in the house sparrow than in the Japanese quail. On the other hand, melatonin induced a further large decrease of body temperature in a nocturnal bird, the owl, whose pineal gland is degenerate. The decrease of body temperature was larger in the active phase than in the resting phase, and melatonin did not prevent movement in spite of the decrease in body temperature. These results suggest that the effects of melatonin on circadian rhythm, locomotor activity and body temperature differ among avian species, and that these mechanisms may not be linked to each other.

Soluble CD44 in human ovarian follicular fluid

PURPOSE

In the present study, we investigated the existence of soluble CD44 (sCD44) in human follicular fluid, the relationship between the concentration of sCD44 and that of other hormonal parameters, and the prognostic value of sCD44 in follicular fluid in in vitro fertilization (IVF) programs.

METHODS

A total of 63 follicular fluid specimens from patients (n = 30) participating in our IVF programs was analyzed by RIA and enzyme-linked immunosorbent assay (ELISA).

RESULTS

The mean concentration (+/- SE) of sCD44 in follicular fluid was 265.4 +/- 7.8 ng/ml. The variation of the follicular fluid concentration of sCD44 was strictly associated with that of human chorionic gonadotropin (hCG) (r = 0.572, P < 0.0001). The mean concentration of sCD44 in follicular fluid was significantly higher in follicles containing subsequently unfertilized oocytes than that in those containing oocytes that had undergone fertilization (P = 0.0428). In the analysis of each follicle that contained an oocyte subsequently fertilized, the mean concentration of sCD44 was significantly higher in follicular fluid with the subsequently good-quality embryos than in that with the subsequently poor-quality embryos (P < 0.05).

CONCLUSIONS

These results indicated that the concentration of sCD44 in follicular fluid reflects the development of embryos derived from the same follicle, so the sCD44 in human follicular fluid may be useful in the assessment of the prognostic value of IVF programs.

Enantiomeric determination of L- and D-lactic acid in human cerebrospinal fluid by chiral ligand exchange high-performance liquid chromatography

Enantiomeric determination of L- and D-lactate in human cerebrospinal fluid (CSF) was achieved by HPLC on a chiral stationary phase with UV detection. Samples were submitted to a solid-phase extraction procedure using Oasis HLB Plus Extraction Cartridge and L- and D-lactate in the extract were separated by Shodex ORpac CRX-453 B column, a ligand exchange column for chiral separation, using a mobile phase containing copper (II) ion. L- and D-lactate were determined in 25 min. Intra-assay precision in CSF was 4.98% (mean 1.85 mmol/L) for L-lactate and 10.1% (mean 4.96 micromol/L) for D-lactate (n = 5). Detection limits were between 1.0 (L-lactate) and 1.5 (D-lactate) pmol. The mean values (n = 3) of analytical recovery for L- and D-lactate were 95% and 107%, respectively. The mean +/- SD of concentrations of L- and D-lactate in CSF (n = 20) were 1.52 +/- 0.54 mmol/L and 10.98 +/- 5.15 micromol/L, respectively.

Both corticotropin releasing factor and neuropeptide Y are involved in the effect of orexin (hypocretin) on the food intake in rats

Orexin (hypocretin) is a peptide that has been found to stimulate food intake in rats. However, we have recently demonstrated that orexin stimulates the release of corticotropin releasing hormone (CRF) which has been known to decrease the food intake. Therefore, we examined the mechanism of effect of orexin on food intake. Although the other appetite stimulating peptides; neuropeptide Y (NPY), agouti-related peptide (AGRP) and one of the growth hormone releasing secretagogue (GHRP-6) stimulated dose-dependently the food intake during 2 h in the early light period, orexin did not increase significantly the food intake. No significant increase was also observed during 2 h in the early dark period. However, pretreatment with alpha-helical CRF, an antagonist of CRF, or anti-CRF antiserum resulted in significant increase of food intake by orexin. Orexin-stimulated feeding under these conditions was blocked by NPY Y1 receptor antagonist (1229U91). In an 8 h-fasting rat, anti-orexin serum decreased slightly the food intake. These results suggest that effect of orexin on the food intake may be complex because of orexin-CRF and orexin-NPY linkage.

The increase of memory T cell subsets in children with idiopathic nephrotic syndrome

Two-color and three-color flow cytometry was carried out to determine whether the memory T cells (CD45RO+ T cells) play a major role in lymphocyte dysfunction of 26 children with idiopathic nephrotic syndrome (INS). The INS patients were divided into three groups: (1) 10 patients who were not receiving glucocorticoid hormone (GCH) and were suffering from acute nephrotic state were referred to as N1; (2) 8 patients who were in remission maintained by GCH therapy alone were referred to as N2; (3) 8 patients who were free of GCH therapy for at least 4 months were referred to as N3. Group N1 demonstrated a significant increase in the percentage of CD45RO+CD4+ T cells and CD45RO+CD8+ T cells (p < 0.05) compared with 11 controls, and these subsets were noted to have a tendency to decrease to control levels in groups N2 and N3. Furthermore, interleukin-2 receptor-alpha expressed subsets in CD45RO+CD4+ T cells (CD45RO+CD4+CD25+ T cells) were also increased only in group N1 (p < 0.02). A similar tendency of absolute counts was observed in these subsets. These results suggest that activated memory T cells reflect lymphocyte dysfunction at initial onset or relapse in INS children.

Neurochemical monitoring in the management of severe head-injured patients with hypothermia

The neuroprotective action and effect of hypothermia on the neurochemical system is not well understood. The present study was performed using six patients with GCS scores of 5 or less to clarify the relationship between monitored brain temperature, intracranial pressure (ICP), cerebral perfusion pressure (CPP) and oxygen saturation of the jugular venous blood (SjO2). Changes in concentration of excitatory amino acids, glutamate (GLU) and aspartate (ASP), and NO2 were studied using intracerebral microdialysis as well as in jugular venous blood and cerebrospinal fluid (CSF). Changes in brain temperature, CPP and SjO2 resulting from hypothermia and brain death associated with markedly higher concentrations of and fluctuations in the concentrations of GLU, ASP and NO2 were observed in the dialysate than in the jugular venous blood or CSF. Hypothermic treatment significantly reduces excitatory amino acid and NO2 concentrations, a finding which was associated with an improvement in CPP and SjO2. Measurement of GLU and ASP using intracerebral microdialysis is a clinically useful method for clarifying abnormal neurochemical events associated with severe head injury and for evaluating the effects of hypothermia.

[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.

Visualization of the calcitonin receptor-like receptor and its receptor activity-modifying proteins during internalization and recycling

Expression of the calcitonin receptor-like receptor (CRLR) and its receptor activity modifying proteins (RAMPs) can produce calcitonin gene-related peptide (CGRP) receptors (CRLR/RAMP1) and adrenomedullin (AM) receptors (CRLR/RAMP2 or -3). A chimera of the CRLR and green fluorescent protein (CRLR-GFP) was used to study receptor localization and trafficking in stably transduced HEK 293 cells, with or without co-transfection of RAMPs. CRLR-GFP failed to generate responses to CGRP or AM without RAMPs. Furthermore, CRLR-GFP was not found in the plasma membrane and its localization was unchanged after agonist exposure. When stably coexpressed with RAMPs, CRLR-GFP appeared on the cell surface and was fully active in intracellular cAMP production and calcium mobilization. Agonist-mediated internalization of CRLR-GFP was observed in RAMP1/CGRP or AM, RAMP2/AM, and RAMP3/AM, which occurred with similar kinetics, indicating the existence of ligand-specific regulation of CRLR internalization by RAMPs. This internalization was strongly inhibited by hypertonic medium (0.45 m sucrose) and paralleled localization of rhodamine-labeled transferrin, suggesting that CRLR endocytosis occurred predominantly through a clathrin-dependent pathway. A significant proportion of CRLR was targeted to lysosomes upon binding of the ligands, and recycling of the internalized CRLR was not efficient. In HEK 293 cells stably expressing CRLR-GFP and Myc-RAMPs, these rhodamine-labeled RAMPs were co-localized with CRLR-GFP in the presence and absence of the ligands. Thus, the CRLR is endocytosed together with RAMPs via clathrin-coated vesicles, and both the internalized molecules are targeted to the degradative pathway.

[Glioblastoma with a marked elevation of total protein and albumin in the cerebrospinal fluid]

We describe a patient with glioblastoma who showed very high levels of total protein and albumin in the cerebrospinal fluid. The patient was a 57-year-old man who underwent subtotal removal of a glioblastoma from the left temporal lobe. Two weeks after the operation, he had quadriplegia and a lumbar puncture was performed. The concentrations of total protein and albumin in the cerebrospinal fluid were 6000 mg/dl and 3600 mg/dl, respectively, which were more than 100 times higher than the upper limits of the reference ranges and were close to their serum levels. The magnetic resonance image suggested that these abnormal values were due to total spinal cord dissemination of the tumor. The results of the cerebrospinal fluid examination showed that the albumin concentration in the fluid might increase to the serum level and the prozone phenomenon should be kept in mind when measuring its concentration in the fluid.

[Exercise training improves activities of daily living in elderly patients with congestive heart failure]

Exercise training which is one of the multidisciplinary interventions for elderly patients with congestive heart failure, plays an important role for improving the quality of life and reducing the re-admission rate of these patients. We assessed the validity of exercise training for the improvement of patient's skeletal muscle functions and activities of daily living along with monitoring cardiac functions. Exercise training programs were performed in 12 patients with congestive heart failure (New York Heart Association class III or IV), including 5 with valvular disease, 4 with dilated cardiomyopathy and 3 with ischemic cardiomyopathy (mean 79 +/- 9 years). All patients were admitted because of exacerbation of congestive heart failure and were treated conventionally. The exercise training program was started after stabilization of their cardiac condition. The medication was not changed during the training period. After exercise training programs, the cardio-thoracic ratio decreased from 63.8 +/- 7.9% to 60.1 +/- 6.9% (p < 0.01), ejection fraction on echocardiography increased from 47.4 +/- 18.2% to 56.0 +/- 17.5% (p < 0.01), and brain natriuretic peptide decreased from 404.8 +/- 267.5 pg/ml to 313.6 +/- 239.5 pg/ml (p < 0.05). The quadriceps muscle power increased from 0.77 +/- 0.36 Nm/kg to 0.97 +/- 0.41 Nm/kg (p < 0.01). The maximum walking distance on flat surface increased from 149 +/- 164 m to 456 +/- 394 m (p < 0.05). In most patients, the activities of daily living, especially mobility, improved. Appropriate exercise training for the elderly patients with congestive heart failure improves activities of daily living and also reduces the amount of required care by the patients.

External quality control study of lymphocyte subset tests in Japan

We have evaluated external quality assurance of lymphocytes subset tests in Japan. The data suggest: 1) Values of lymphocyte subsets were variable at each medical laboratory in Japan. 2) Value of CD3 did not varied so much, but that of CD 19/20 or NK marker was widely varied. 3) Values of CD4 and CD8 varied in small extension. 4) CV of values was relatively low when analysis was carried out in commercial laboratories or when antibodies and instrument of Ortho-Clinical Diagnostics were used. 5) In some cases, CV was also relatively low if number of cell washing times was low or if self made lytic agents were used for cell lysing.

Volatile chemicals identified in extracts from leaves of Japanese mugwort (Artemisia princeps pamp.)

Extracts from leaves of Japanese mugwort (Artemisia princeps Pamp.) were obtained using two methods: steam distillation under reduced pressure followed by dichloromethane extraction (DRP) and simultaneous purging and extraction (SPSE). A total of 192 volatile chemicals were identified in the extracts obtained by both methods using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). They included 47 monoterpenoids (oxygenated monoterpenes), 26 aromatic compounds, 19 aliphatic esters, 18 aliphatic alcohols, 17 monoterpenes (hydrocarbon monoterpenes), 17 sesquiterpenes (hydrocarbon sesquiterpenes), 13 sesquiterpenoids (oxygenated sesquiterpenes), 12 aliphatic aldehydes, 8 aliphatic hydrocarbons, 7 aliphatic ketones, and 9 miscellaneous compounds. The major volatile constituents of the extract by DRP were borneol (10.27 ppm), alpha-thujone (3.49 ppm), artemisia alcohol (2.17 ppm), verbenone (1.85 ppm), yomogi alcohol (1.50 ppm), and germacren-4-ol (1.43 ppm). The major volatile constituents of the extract by SPSE were 1,8-cineole (8.12 ppm), artemisia acetate (4.22 ppm), alpha-thujone (3.20 ppm), beta-caryophyllene (2.39 ppm), bornyl acetate (2.05 ppm), borneol (1.80 ppm), and trans-beta-farnesene (1. 78 ppm).

Induction of unseasonable hibernation and involvement of serotonin in entrance into and maintenance of its hibernation of chipmunks T. asiaticus

Chipmunks that had been housed at 22 degrees C under a light-dark cycle of 14L:10D for at least one year were exposed to a short photoperiod (10L:14D) and low temperature to induce unseasonable hibernation. We were able to induce hibernation at any time of year and there was no significant difference in the duration of the hibernation bout, the duration of interbout euthermia and duration of bouts of torpor throughout the year; however entrance into hibernation took about 60 days in summer but only about 30 days in any other seasons. In addition, interbout euthermia predominantly occurred during the light phase in winter, whereas in spring interbout euthermia occurred equally in the light and dark phases. These results suggest that both the circadian and circannual systems are linked to hibernation in chipmunks. Subcutaneous infusion of a serotonin antagonist, para-chlorophenylalanine (PCPA), facilitated entrance into and interrupted hibernation in aroused and hibernating chipmunks in summer, respectively. On the other hand, opioid antagonist, naloxone, did not affect hibernation, but extended the period of interbout euthermia. These results suggest that the role of serotonin in entrance into and maintenance of hibernation in chipmunks is independent of the circannual system, and that opioid system may not be involved in hibernation in chipmunks.

Diesel exhaust particles activate human bronchial epithelial cells to express inflammatory mediators in the airways: a review

OBJECTIVE

Epidemiological as well as experimental studies suggest that particulate air pollutants, including diesel exhaust particles (DEP), may play a role in the recent increase of respiratory morbidity and mortality. We studied the effect of DEP on the production of inflammatory cytokines and mediators including IL-8 and granulocyte macrophage colony stimulating factor (GM-CSF) by human airway epithelial cells in vitro.

METHODOLOGY

Suspended DEP were added to cultured normal human bronchial epithelial cells or transformed BEAS-2B cells. The release of cytokines and mediators was evaluated by enzyme-linked immunosorbent assay. The transcriptional levels of IL-8 mRNA was studied by northern blot analysis and run-on transcription assay. Activation of transcription factors was assessed by electrophoretic mobility shift assay.

RESULTS

Non-toxic doses of suspended DEP showed a significant stimulatory effect on IL-8 and GM-CSF production by airway epithelial cells. Diesel exhaust particles increased the steady-state levels of IL-8 mRNA, which was suggested to be largely due to increased transcriptional rates. Electrophoretic mobility shift assay demonstrated that DEP induced increased binding to the specific motif of nuclear factor (NF)-kappaB, but not of transcription factor AP-1. Both N-acetylcysteine and pyrrolidine dithiocarbamate attenuated the action of DEP on IL-8 mRNA expression, suggesting that oxidant-mediated pathway might be involved in its processes. Transient transfection of airway epithelial cells with wild and NF-kappaB binding motifs indicated that the activation of NF-kappaB was essential for IL-8 gene upregulation by reporter gene assay.

CONCLUSIONS

These results suggested that DEP activate NF-kappaB, which might be an important pathway for the expression of inflammatory cytokines in vitro.

Diesel exhaust particles up-regulate expression of intercellular adhesion molecule-1 (ICAM-1) in human bronchial epithelial cells

Epidemiological and experimental studies suggest that diesel exhaust particles (DEP) may play an active role in the increased respiratory mortality and morbidity. We have shown that DEP augmented the production of inflammatory cytokines by human airway epithelial cells in vitro. ICAM-1 has been shown to play an important role in the local accumulation of inflammatory cells. We studied the effect of DEP on ICAM-1 gene expression and surface expression in human bronchial epithelial cell line BEAS-2B. DEP (5-50 microg/ml) showed a stimulatory effect on ICAM-1 mRNA levels as evaluated by reverse transcription-polymerase chain reaction (RT-PCR). Flow cytometric analysis demonstrated an increased ICAM-1 expression on the epithelial cell surfaces. The soluble form of ICAM-1 molecules was also increased by the stimulation of DEP. In vitro neutrophil attachment onto DEP-stimulated epithelial cells was augmented, which was partially blocked by anti-ICAM-1 neutralizing antibody. Finally, these events were significantly inhibited by pretreatment with anti-oxidants pyrrolidine dithiocarbamate and N-acetyl cysteine, and p38 mitogen activated protein kinase (MAPK) inhibitor SB203580. These findings suggested that DEP induced up-regulation of ICAM-1 gene, and this process might be largely dependent on oxidant-mediated NF-kappaB activation and p38-MAPK pathways.

Possible involvement of orexin in the stress reaction in rats

We examined whether corticotropin-releasing factor (CRF) was involved in orexin-induced grooming and face-washing behaviors, and whether orexin was involved in the stress reaction. Administration of alpha-helical CRF, CRF antagonist, alone had no behavioral effect, but it blocked the orexin-induced grooming and face-washing behaviors in rats. The level of corticosterone increased in a dose-dependent manner 15 min after icv injection of orexin, and it remained high for at least 60 min. In 2-month-old rats, 1 h of immobilization stress increased orexin mRNA levels, but not the melanin-concentrating hormone (MCH) mRNA, in the lateral hypothalamic area (LHA). In 6-month-old rats, 30 min of cold stress increased the expression of orexin mRNA in the LHA. Unlike in the 2-month-old rats, immobilization stress did not change orexin mRNA expression in 6-month-old rats. These results suggest that CRF is involved in orexin-induced behaviors, and that orexin may play an important role in some stress reactions.

A monoclonal antibody specific to the granulocyte-derived elastase-fragment D species of human fibrinogen and fibrin: its application to the measurement of granulocyte-derived elastase digests in plasma

When granulocytes are stimulated under certain clinical conditions, elastase is released therefrom and digests fibrin(ogen) independently of the plasmin system, which may also be mobilized simultaneously. Thus, discrimination of these 2 systems becomes urgent for the diagnosis and treatment of the underlying diseases. Using as immunogen a 97-kd granulocyte-elastase digest of human fibrinogen, we raised an antibody IF-123 that specifically recognizes elastase digests of human fibrin(ogen). The 97-kd elastase fragment resembles plasmic fragment D(1), and the epitope of this antibody is located on the Aalpha (196-204) residue segment. This segment appears to be masked in fibrin(ogen) but exposed when the Aalpha Leu 204-Ile 205 peptide bond is cleaved by elastase. Cathepsin G concomitantly released from granulocytes failed to expose the epitope. By an enzyme immunoassay using IF-123 as the capture antibody, the elastase digests of fibrin(ogen) can be measured in plasma samples without interference by abundantly coexisting fibrinogen. Indeed, we found that the elastase digests were mostly elevated in patients with inflammation or malignant tumors, but remained in a normal range in patients with a benign gastrointestinal tract disease such as duodenal ulcer and polyps in the gallbladder or the colon. Like the plasmic D-dimer, the elastase digests predominantly consisted of the DD/E complex and DD/E-containing high-molecular weight derivatives apparently corresponding to the phase-3 plasmic digests of cross-linked fibrin. (Blood. 2000;95:1721-1728)

Long-term intravenous perinatal cocaine exposure on the mortality of rat offspring

To examine the effects of chronic perinatal cocaine exposure, cocaine was administered intravenously throughout pregnancy and the postpartum period to the rat. Pregnant rats were divided into five groups: nontreated (naive); normal saline control (saline); cocaine first generation (cocaine); saline in the first generation and cocaine in the second generation (Sal-2G); and cocaine in both first and second generations (Coc-2G). The rats receiving cocaine in the second generation (Sal-2G and Coc-2G) were offspring of the saline and cocaine group, respectively. All cocaine-treated groups received cocaine 2 mg/kg/day intravenously (IV), and the saline group received normal saline 0.2 ml/day IV from GD 2 to the 21st day postpartum. Mean perinatal mortality was greater in all pups exposed to cocaine in utero during gestation; Cocaine (6.4%); Sal-2G (5.6%); Coc-2G (11.4%) groups than in the noncocaine groups (3.2%, 1.3%). Weight gain, physical, and neurological developments of the offspring were not affected. It was concluded that perinatal cocaine exposure had an increased perinatal mortality even at doses approximately 10 times lower than those previously reported, which were administered by extravascular routes. These findings indicate the importance of the route of drug administration in perinatal cocaine research.

Hyaluronic acid inhibits apoptosis in granulosa cells via CD44

PURPOSE

This study was designed to examine whether hyaluronic acid (HA) inhibits apoptosis in cumulus and mural granulosa cells and to examine whether this effect of HA was mediated through CD44.

METHODS

Mural and cumulus granulosa cells were obtained from in vitro fertilization patients. The cells were cultured with various concentrations of HA or HA plus various concentrations of anti-CD44 antibody without serum supplement. After 24 hr of culture, the cells were fixed and stained with Hoechst 33258. One thousand granulosa cells of each conditions were observed by fluorescence microscopy.

RESULTS

HA inhibited apoptosis in both kinds of granulosa cells, and anti-CD44 antibody prevented this effect of HA.

CONCLUSIONS

The incidence of apoptotic granulosa cells with fragmented condensed nuclei was reduced by HA via CD44.

Red wine polyphenols inhibit proliferation of vascular smooth muscle cells and downregulate expression of cyclin A gene

BACKGROUND

Red wine polyphenols have been shown to contribute to the "French paradox" phenomenon, which consists of lower morbidity and mortality from coronary heart disease in the French population. Although vascular smooth muscle cell (VSMC) proliferation plays an important role in the progression of atherosclerotic lesions, the effects of red wine polyphenols on VSMC proliferation have not been elucidated.

METHODS AND RESULTS

We extracted the total polyphenolic fraction from red wine (RW-PF) by column chromatography. Treatment with RW-PF showed a potent inhibitory effect on the proliferation and DNA synthesis of cultured rat aortic smooth muscle cells (RASMCs). In contrast, the inhibitory effect of RW-PF on the proliferation of bovine carotid endothelial cells was observed only at much higher concentrations. To elucidate the molecular mechanisms of this antiproliferative effect of RW-PF on RASMCs, we investigated the effects of RW-PF on cell cycle regulation. RW-PF downregulated the expression of cyclin A mRNA and cyclin A promoter activity. In addition, RW-PF decreased the binding of nuclear proteins to the activating transcription factor (ATF) site in the cyclin A promoter and downregulated the mRNA levels of transcription factors, cAMP-responsive element-binding protein (CREB), and ATF-1.

CONCLUSIONS

These results suggest that the downregulation of cyclin A gene expression may contribute to the antiproliferative effect of red wine polyphenols on RASMCs through the inhibition of transcription factor expression.

Structural analysis of the gene encoding RP58, a sequence-specific transrepressor associated with heterochromatin

RP58, a sequence-specific transcriptional repressor sharing homology with the POZ domain of a number of zinc-finger proteins, is highly synthesized in brain and localized in condensed chromatin regions, suggesting a role in transcriptional repression in the central nervous system. In the present study, genomic clones of the human rp58 gene were isolated to determine the complete genomic organization. Sequence analyses indicated that the human rp58 gene encoding the functional protein is uninterrupted over its entire 4.2 kb length. Comparison of the human and mouse rp58 genes revealed that they share not only a high homology in the amino acid sequences of their encoded proteins, but also a high degree of structural similarity at the genomic level. RT-PCR analysis also demonstrated the existence of an alternatively spliced form of rp58 similar to the previously reported zinc-finger cDNA, C2H2-171. Chromosomal mapping by fluorescence in situ hybridization analysis allowed localization of the rp58 gene to human chromosome 1q44 ter, a genetic region associated with a number of human malignancies and neurological disorders.