Human dis3p, which binds to either GTP- or GDP-Ran, complements Saccharomyces cerevisiae dis3

Saccharomyces cerevisiae Dis3p, which interacts with Ran/Gsp1p, complements Schizosaccharomyces pombe dis3-54. Consistent with the functional conservation of Dis3p in S. cerevisiae and S. pombe, the human ORF (accession number: R27667) was found to be highly homologous to yeast Dis3p. Based on its nucleotide sequence, we cloned a full-sized human DIS3 cDNA. The cloned human cDNA partly but significantly restored the temperature-sensitivity of S. cerevisiae dis3. Thus, Dis3p was found to be structurally and functionally conserved from yeast to mammals. Consistent with the report that S. cerevisiae Dis3p is identical to Rrp44p, which comprises the exosome involved in ribosomal RNA processing, S. cerevisiae Dis3p was found to be localized in the nucleolus. Similar to S. cerevisiae Dis3p, human Dis3p enhanced RCC1-stimulated nucleotide release from Ran, in a dose-dependent manner, and bound to GTP- or GDP-Ran.

Prevalence of ischemic heart disease among patients with sleep apnea syndrome

We investigated the prevalence of ischemic heart disease (IHD) in sleep apnea syndrome (SAS) and the presence of coronary risk factors involved in the onset of IHD in 386 subjects with suspected SAS due to heavy snoring. The prevalence of IHD among patients with untreated SAS was found to be 23.8%, and the percentage of patients having SAS complicated with IHD was high among those with moderate or severe SAS. Sleep apnea syndrome patients with IHD also showed high prevalences of hypertension and hyperlipidemia. It appears that sleep apnea aggravates the factors that cause coronary vascular disorders, and is involved in the onset of IHD.

Ubc9p and the conjugation of SUMO-1 to RanGAP1 and RanBP2

The yeast UBC9 gene encodes a protein with homology to the E2 ubiquitin-conjugating enzymes that mediate the attachment of ubiquitin to substrate proteins [1]. Depletion of Ubc9p arrests cells in G2 or early M phase and stabilizes B-type cyclins [1]. p18(Ubc9), the Xenopus homolog of Ubc9p, associates specifically with p88(RanGAP1) and p340(RanBP2) [2]. Ran-binding protein 2 (p340(RanBP2)) is a nuclear pore protein [3] [4], and p88(RanGAP1) is a modified form of RanGAP1, a GTPase-activating protein for the small GTPase Ran [2]. It has recently been shown that mammalian RanGAP1 can be conjugated with SUMO-1, a small ubiquitin-related modifier [5-7], and that SUMO-1 conjugation promotes RanGAP1's interaction with RanBP2 [2,5,6]. Here we show that p18(Ubc9) acts as an E2-like enzyme for SUMO-1 conjugation, but not for ubiquitin conjugation. This suggests that the SUMO-1 conjugation pathway is biochemically similar to the ubiquitin conjugation pathway but uses a distinct set of enzymes and regulatory mechanisms. We also show that p18(Ubc9) interacts specifically with the internal repeat domain of RanBP2, which is a substrate for SUMO-1 conjugation in Xenopus egg extracts.

[Pregnancy and delivery in the patients with spina bifida--report of 5 cases]

BACKGROUND

Because of improvement in the management for life-threatening complications of spina bifida, quality of life in the patient has become better and pregnancy is becoming more common problem in adolescent and adult female patients. In this paper, we reported patients with spina bifida who became pregnant and delivered a baby.

METHODS

There were 6 deliveries from 5 patients. Mean patient age at the first pregnancy was 27.6 years (ranged from 26 to 32 years). Four patients had undergone surgical managements before pregnancy, of whom 1 had augmentation cystoplasty. Urological and obstetrical conditions during the pregnancy were analyzed.

RESULTS

Upper urinary tract deterioration which was transient, was observed in 3 pregnancies. Serum BUN and creatinine levels remained stable throughout pregnancy in 4 patients. Pyelonephritis complicated 3 of 6 pregnancies. Delivery was vaginal in 4 and by cesarean section in 2. There were 7 obstetrical complications, which consisted of premature labor (2), uterine inertia (2), cephalo pelvic disproportion (2) and hydramnios (1). There were no significant anomalies in the newborns of these patients.

CONCLUSION

To achieve successful pregnancy and delivery in the patient with spina bifida, careful urological and obstetrical observation for the potential complications is needed.

[Long-term follow up of patients with spina bifida--a review of 228 cases]

BACKGROUND

The objective of this report is to evaluate the upper urinary tract changes of the patients with spina bifida who have been followed up for more than 10 years.

METHODS

We analyzed 228 patients (97 males and 131 females) of spina bifida. Mean patient age was 18.7 years (10 to 51 years) and follow up period ranged from 10 to 27 years (mean 13.4 years). Upper urinary tract deterioration (Hydroureter and/or hydronephrosis), vesicoureteral reflux (VUR) and bladder deformity were investigated by excretory urography and voiding cystourethrography. We compared these 3 parameters in the initial and final examinations.

RESULTS

In the initial examinations, upper urinary tract deterioration, VUR and bladder deformity were observed in 32.9%, 33.3% and 40.0%, respectively. During the follow up period, upper urinary tract was improved in 47.3% and VUR in 80.0%. Bladder deformity was disappeared in 14.4%. On the other hand, upper urinary tract was deteriorated in 9.3%. VUR and bladder deformity was newly developed or progressed in 8.0% and 29.3%, respectively. Finally, upper urinary tract deterioration, VUR and bladder deformity were observed in 31.3%, 18.2% and 52.0%, respectively.

CONCLUSION

These results revealed that upper urinary tract and VUR were relatively controlled, however, bladder deformity was increased in its frequency. To prevent upper urinary tract deterioration, further analysis of sequential changes of urinary tract conditions should be demanded.

Proviral inactivation of the Npat gene of Mpv 20 mice results in early embryonic arrest

The Mpv 20 transgenic mouse strain was created by infection of embryos with a defective retrovirus. When Mpv 20 heterozygous animals were crossed, no homozygous neonatal mice or midgestation embryos were identified. When embryos from heterozygous crosses were cultured in vitro, approximately one quarter arrested as uncompacted eight-cell embryos, indicating that proviral insertion resulted in a recessive lethal defect whose phenotype was manifest very early in development. Molecular cloning of the Mpv 20 insertion site revealed that the provirus had disrupted the Npat gene, a gene of unknown function, resulting in the production of a truncated Npat mRNA. Expression of the closely linked Atm gene was found to be unaffected by the provirus.

[Long-term follow-up of female tetraplegic patients with cutaneous vesicostomy]

Tetraplegic women who underwent a cutaneous vesicostomy in our institutions were studied to evaluate long-term urinary complications and their quality of life (QOL). A total of 5 patients (C4, C5 and C6 injuries in one patient each and C7 injury in 2) were followed for 98 to 125 months (mean 107 months). Autonomic hyperreflexia disappeared after surgery in all patients. None of the patients showed deterioration of the upper urinary tract. Urinary tract infections were noted in 3 of 5 patients, but not severe. Bladder stones developed in 2 patients and a stomal stricture in 1. A questionnaire survey showed the patients to be satisfied with the operation, which had improved their QOL. These findings suggest that a cutaneous vesicostomy is an excellent surgical procedure for tetraplegic women.

[Development of a regimen comprehension scale]

Whether elderly patients can take prescription drugs as directed by a physician is often unclear. So elderly patients could receive adequate instruction regarding their medications, we developed a regimen comprehension scale (RCS) with simple questions regarding information on dosage and administration. This information was written on the outside of the paper bags in which the medications are usually dispensed. The subjects were 21 healthy volunteers (11 men and 10 women, averaged age 38.3 +/- 11.2 years) and 17 inpatients (9 men and 8 women, averaged age 73.4 +/- 6.8 years). Five kinds of drugs, which differed with respect to dosage and administration were used. The subjects were questioned in an interview about taking the five drugs and their regimen comprehension was assessed with the RCS (maximum score: 10 points, lowest score: 10 points. Then regimen comprehension was classified into 4 grades: normal (10), caution needed (9 or 8), training needed (7 or 6), and assistance needed (5 or less). In addition, intelligence was tested with the revised version of Hasegawa's dementia scale (HDS-R). Eight of the 21 healthy volunteers (38%) and 13 of the 17 elderly patients (76%) misunderstood some aspects of the regimens written on the paper bags. The regimen comprehension was classified as "normal", "caution needed", and "training needed" in 13, 7, and 1 of the healthy volunteers, respectively, it was classified as "normal", "caution needed", "training needed", and "assistance needed" in 4, 4, 4, and 5 elderly patients, respectively. The five elderly patients classified as "assistance needed" were suspected to have dementia because they had scores on the HDS-R of 21 or less. A significant positive correlation (r = 0.797) was noted between scores on the HDS-R and on the RCS. When treating elderly patients with chronic disease (for example, hypertension) it is important to evaluate their regimen comprehension with an index such as the RCS to determine the need for medication counseling before the start of a medication regimen.

[Electroejaculation and assisted reproductive techniques in the patients with spinal cord injury]

BACKGROUND

Most of the patients with spinal cord injury (SCI) have fertility problems by an ejaculation and a poor fertility of the ejaculate. The objective of this paper is to evaluate the clinical effectiveness of electroejaculation (EE) and combined use of EE and assisted reproductive techniques for the patients with SCI.

PATIENTS AND METHODS

Using a Seager Model, EE was attempted on 69 patients with SCI. Of the 69 patients 14 (20%) had cervical, 49 (71%) thoracic and 6 (9%) lumbar paraplegia. Mean patient age was 30 years (range 19 to 47 years) and the mean interval from spinal injury to the first EE was 9 years (range 1 to 38 years). Artificial insemination of husband (AIH), in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) were used to achieve a pregnancy.

RESULTS

Antegrade ejaculation was obtained in 60 patients (86.9%). Patients with under-active bladder showed low induction rate (58.3%). Volume of ejaculate was ranged from 0.05 to 5.2 ml (average 1.0 ml) and sperm concentration was ranged from 0 to 546 x 10(6)/ml (average 40.3 x 10(6)/ml), but sperm motility was poor (range 0 to 70%, average 9.4%). Assisted reproductive techniques was attempted on 87 occasions (AIH 80, IVF 2, ICSI 5) on 15 couples. To date, there have been 4 pregnancies (AIH 2, ICSI 2) resulting in 3 healthy live births.

CONCLUSION

Combined use of EE and assisted reproductive techniques is excellent management for the patients with SCI who wish to father children.

[A comparative study of the effects of granisetron alone and a combination of granisetron plus steroids on CDDP-based combination chemotherapy-induced emesis--outcomes of a multicenter randomized comparative study using the central registration method. Nara Medical University Kytril Study Group]

The present investigation was conducted to examine the effects of granisetron alone and a combination of granisetron plus steroids on CDDP-based combination chemotherapy-induced emesis by multi-institutional randomized comparative trial using a central registration method. A total of 62 patients with urological cancer enrolled this study were randomized into two groups: granisetron (40 micrograms/kg) only group and granisetron (40 micrograms/kg) plus steroids (500 mg of methylprednisolone or 8 mg of dexamethasone) group. There were 31 patients eligible in the granisetron only group and 28 in the combination group. The same anti-emetic treatments were given in the recycling courses of chemotherapeutic regimens. Therefore, eligible patients of the second and the third cycle numbered 31 (17 in the granisetron only group, 14 in the combination group) and 21 (11 in the granisetron only group and 10 in the combination group). Significant inhibition of acute emesis in combination group was observed when compared with the granisetron only group in each cycle. Delayed emesis was also significantly inhibited in the combination group on Day 2 and 3 of the first cycle and on Day 2 of the second and third cycle. In addition, appetite loss was significantly reduced in the combination group on Day 2 and 3 of the first and second cycle. No adverse events were seen in either group. These results suggested that a combination of granisetron and steroids was useful for preventing CDDP-based combination chemotherapy-induced emesis.

A survey of habitual snoring in centenarians

OBJECTIVE

To ascertain whether centenarians in the surveyed group would be nonhabitual snorers.

DESIGN AND SETTING

A cross-sectional survey of centenarians residing in the Aichi Prefecture of Japan.

PARTICIPANTS

A total of 103 centenarians (21 men and 82 women).

MEASUREMENTS

Questionnaire on sleep habits, breathing, and snoring.

RESULTS

Nineteen centenarians (18.4%; 5 men and 14 women) were habitual snorers and two (1.9%) were suspected of having sleep apnea syndrome because of the presence of heavy snoring and nocturnal respiratory arrest.

CONCLUSION

Most centenarian subjects were nonsnorers and without breathing pauses during sleep; their snoring rates were no different from those of younger aged older adults in the same population.

Current status of antihypertensive therapy for elderly patients in Japan

To assess how elderly Japanese hypertensive patients are treated by specialists, we conducted a cross-sectional survey. A total of 1,163 outpatients aged 50 years or older were studied. Hypertension was diagnosed in 939 of these patients, and 827 were receiving drug therapy. The average blood pressure during therapy was 143 +/- 16/81 +/- 10 mmHg. In patients aged 70 years or older, systolic blood pressure during antihypertensive therapy was significantly higher (p < 0.01) and diastolic blood pressure was significantly lower (p < 0.01) than the corresponding values in those aged 50 to 59 years or 60 to 69 years. The calculated mean blood pressures were similar in the different age groups. The rate of monotherapy in the patients aged 70 years or older was 58.8%, which was significantly higher (p < 0.01) than the rates of monotherapy in the other age groups. Calcium channel blockers were prescribed in about 80% of patients, irrespective of age or comorbidity. Of the patients receiving calcium channel blockers, 43.5% were treated with monotherapy. This rate significantly (p < 0.01) increased with advancing age. Diastolic blood pressures were significantly lower (p < 0.05) in patients with stroke and in those with ischemic heart disease, diabetes mellitus, or dyslipidemia, as compared with patients with no comorbidity. Among patients aged 70 years or older, the difference in systolic blood pressure between those with ischemic heart disease and those with no comorbidity was not significant. Blood pressure in elderly hypertensive patients was reduced to a level similar to that in younger patients. The target blood pressure was influenced by the presence of comorbidity. Furthermore, specialists showed a high preference for the use of calcium channel blockers in the management of hypertension.

Chromosomal localization of the mouse and rat DNA double-strand break repair genes Ku p70 and Ku p80/XRCC5 and their mRNA expression in various mouse tissues

The Ku p70 and Ku p80/XRCC5 genes are involved in DNA double-strand break repair and V(D)J recombination, and their gene products are the components of the DNA-dependent protein kinase. We have determined the chromosomal locations of the mouse Ku p70 and Ku p80/XRCC5 genes by both in situ hybridization and molecular linkage analysis: the Ku p70 gene was localized to mouse chromosome 15 and rat chromosome 7, and the Ku p80/XRCC5 gene was localized to mouse chromosome 1 and rat chromosome 9. Both genes were mapped to a region of conserved linkage homology among three species, i.e., the mouse, rat, and human. Molecular linkage analysis using interspecific backcross mice revealed that the murine Ku p70 locus was localized 0.7 cM terminal to D15Mit1 and that the murine Ku p80/XRCC5 locus was 0.7 cM proximal to D1Mit46. To determine the size and tissue transcription specificity of the mouse Ku p70 and Ku p80/XRCC5 mRNA, Northern blot analysis was carried out with six mouse tissues. Each tissue expressed one species of the Ku p70 gene transcript with 2.4 kb and one species of the Ku p80/XRCC5 gene transcript with 2.6 kb. In the latter case, however, the brain showed two sizes of transcript, 2.6 and 2.9 kb.

Retrospective study on the usefulness of radius and lumbar bone density in the separation of hemodialysis patients with fractures from those without fractures

We measured bone mineral density (BMD) at the lumbar spine (LS-BMD), 1/3 radius (1/3R-BMD), and ultradistal radius (UDR-BMD) in 59 men (4 with spine fractures and 4 with nonspine fractures) and 65 women (10 with spine fractures and 9 with nonspine fractures), all receiving maintenance hemodialysis (HD). The BMD at each site expressed absolutely in g/cm2 was significantly lower in women than in men (p = 0.0001). In men, the absolute and age-matched values of both 1/3R- and UDR-BMD were inversely and significantly correlated with the duration of HD, and with serum alkaline phosphatase and parathyroid hormone levels (p < 0.05), whereas such relationships were obscure in women. On the other hand, the absolute values of BMD at each site in women but not in men were inversely and significantly correlated with patient age (p < 0.001). In both sexes, R-BMD was significantly lower in both the spine and nonspine fracture groups than in the nonfracture group (p < 0.05 and p < 0.01, respectively), whereas the only significant difference in LS-BMD was that it was lower in women with spine fractures than in women without fractures, when expressed as its absolute value (p < 0.05). By receiver operating characteristic analyses, both the absolute and age-matched values of R-BMD were better than LS-BMD as a determinant of non-spine fracture histories, and were similar to absolute LS-BMD as a determinant of spine fracture histories. We conclude that R-BMD is more valuable than LS-BMD for discriminating HD patients with all types of fractures from those without fractures.

A novel benzodiazepine inverse agonist, S-8510, as a cognitive enhancer

1. Pharmacological actions of a novel benzodiazepine receptor ligand, S-8510 (2-(3-isoxazolyl)-3,6,7,9-tetrahydroimidazo[4,5-d]pyrano+ ++[4,3-b] pyridine monophosphate monohydrate), were examined in in vitro and in vivo studies. 2. S-8510 was characterized as a partial inverse agonist with a modest GABA ratio and low efficacy. 3. S-8510 ameliorated memory impairment induced by cholinergic deficit in the water maze paradigm of Wistar rats. 4. S-8510 augmented LTP of the Schaffer collateral/commissural fiber-CA1 synapses in the hippocampal slice preparations of SD rat. 5. S-8510 increased the extracellular levels of acetylcholine and noradrenaline in the hippocampus of Wistar rat. 6. S-8510 selectively potentiated pentylenetetrazol-induced convulsion without affecting minimal electroconvulsive shock- or strychnine-induced convulsion in ddY mice. 7. S-8510 failed to induce any sign of anxiety in the Wistar rat pro-conflict test. 8. S-8510 showed antidepressant-like pharmacological actions in ddY mice. 9. These results suggest that S-8510 can be used as a therapeutic drug for senile dementia, including Alzheimer's disease with little risk for inducing anxiety or convulsion.

Urethral opening pressure in patients with myelodysplasia

We evaluated 60 patients with myelodysplasia using the urethral opening pressure (UOP) which is defined as the total intravesical pressure at the moment when urine passes through the external sphincter by the Credé or the Valsalva maneuver. Twenty nine of the patients showed UOP value greater than 35 cmH2O and 31 below 35 cmH2O. In the high pressure group, patients showed a tendency to preserve sphincter activity and had mild paralysis of the lower extremities. In contrast, most of patients in the low pressure group showed an underactive sphincter and severe paralysis of the lower extremities. The incidence of deterioration of the upper urinary tract, vesicoureteral reflux (VUR) and bladder deformity were significantly high in the high pressure group than those in the low pressure group (75.9% vs 16.1%, 72.4% vs 22.6%, 82.8% vs 29.0%, respectively, P < 0.05). During the follow-up period (42 months on average), the voiding methods were changed in 15 patients from the Credé maneuver to clean intermittent catheterization, and total of 12 operations were performed (10 antiVUR operation and two with an ileocystoplasty). Finally, approximately 90% of the patients in both the high and the low pressure groups were evaluated as improved or stable in the upper urinary tract, VUR and bladder deformity after conservative or surgical managements. UOP is considered to be one of the useful parameters to select the high risk patient in the urological management of myelodysplastic patients.

Roles of XPG and XPF/ERCC1 endonucleases in UV-induced immunostaining of PCNA in fibroblasts

To investigate the relationship between proliferating cell nuclear antigen (PCNA) complex formation and dual incisions in the nucleotide excision repair (NER) process, xeroderma pigmentosum group G (XP-G), XP-F, and XP-G equivalent mouse UV-sensitive mutant ERCC group 5 cells were utilized as a model in this study. These cells are deficient in endonucleases related to 3' (XP-G and ERCC group 5) or 5' (XP-F) incision of the DNA lesions in the NER process. PCNA complex formation was detected by an indirect immunofluorescence method after the cells were fixed in methanol. When Sps1 (XP-G) and XL216-7 (ERCC group 5) cells were UV irradiated, neither of them showed PCNA staining. In contrast, SFN4 (a human normal strain) and heterokaryons of Sps1 and XP96TO (XP-A) cells fused by polyethylene glycol treatment showed PCNA staining following UV irradiation. Furthermore, XLgfPAneo1 cells, derived from XL216-7 cells transfected with a plasmid containing mouse ERCC5 (xpg) cDNA, also restored staining and UV sensitivity. On the other hand, we observed a very faint PCNA staining in XP2YO (XP-F) cells, expressing no detectable ERCC1 or XPF protein, after UV irradiation. X rays induced PCNA staining in all cell lines with a similar staining pattern, and radiosensitivity was exactly the same between XL216-7 and XLgfPAneo1 cells. These results may have implications for the NER process in vivo in that coordinately occurring dual incisions by XPG and XPF/ERCC1 proteins play an important role in inducing PCNA complex formation, but the step may not be required for PCNA-dependent repair of X-ray-induced DNA damage.

Comparative genome mapping of the ataxia-telangiectasia region in mouse, rat, and Syrian hamster

Chromosomal locations of the Atm (ataxia-telangiectasia (AT)-mutated) and Acat1 (mitochondrial acetoacetyl-CoA thiolase) genes in mouse, rat, and Syrian hamster were determined by direct R-banding FISH. Both genes were colocalized to the C-D band of mouse chromosome 9, the proximal end of q24.1 of rat chromosome 8, and qa4-qa5 of Syrian hamster chromosome 12. The regions in the mouse and rat were homologous to human chromosome 11q. Fine genetic linkage mapping of the mouse AT region was performed using the interspecific backcross mice. Atm, Acat1, and Npat, which is a new gene isolated from the AT region, and 12 flanking microsatellite DNA markers were examined. No recombinations were found among the Atm, Npat, Acat1, and D9Mit6 loci, and these loci were mapped 2.0 cM distal to D9Mit99 and 1.3 cM proximal to D9Mit102. Comparison of the linkage map of mouse chromosome 9 (MMU9) and that of human chromosome 11 (HSA11) indicates that there is a chromosomal rearrangement due to an inversion between Ets1 and Atm-Npat-Acat1 and that the inversion of MMU9 originated from the chromosomal breakage at the boundary between Gria4 and Atm-Npat-Acat1 on HSA11. This type of inversion appeared to be conserved in the three rodent species, mouse, rat, and Syrian hamster, using additional comparative mapping data with the Rck gene.

Augmented very low frequency component of heart rate variability during obstructive sleep apnea

After documenting the presence of obstructive sleep apnea syndrome (OSAS) through polysomnographic monitoring, we performed simultaneous ambulatory recordings of electrocardiogram, oronasal airflow, and pulse oximetry on 12 OSAS patients with normal autonomic nervous function for a period of 24 hours. The power spectrum of heart rate variability was investigated before and during treatments using dental appliances. Freuquency domain analysis showed that the very low frequency component of heart rate (0.008-0.04 Hz) was increased in OSAS patients and that a very low frequency peak appeared during episodes of obstructive sleep apnea. The increase in very low frequency identification was synchronized with episodes of absence of air exchange or hypoxemia (decreased arterial oxygen saturation) that occurred repeatedly at a cycle length of 25-120 seconds in our subjects. Frequency domain analysis of heart rate variability before and during prosthetic mandibular advancement treatment showed that only the very low frequency was significantly decreased during prosthetic mandibular advancement treatment, whereas the other frequencies, i.e. high, low, and ultralow frequency component values, showed no significant changes. Time domain analysis of heart rate variability before and during prosthetic mandibular advancement treatment showed no significant changes in any of these parameters. Frequency domain analysis of heart rate variability during nocturnal sleep, especially investigation of very low frequency and very low frequency peak, can be a noninvasive low-cost approach to diagnose and even better monitor subjects undergoing treatment at home, particularly considering that R-R intervals can be extracted from pulse oximetry and that analysis software programs are already commercially available.

Blood pressure "dipping" and "non-dipping" in obstructive sleep apnea syndrome patients

Obstructive sleep apnea syndrome (OSAS) has been associated with a higher than normal cardiovascular morbidity and mortality. Some OSAS patients lack the sleep-related, nocturnal decrease, or "dip," in blood pressure which is seen in normal individuals. These subjects, called "non-dippers," may be at greater risk for cardiovascular problems. We studied 40 OSAS patients (including 3 women) and 6 control subjects, all identified by polysomnography, for nocturnal blood pressure "dipping." We performed a second nocturnal polysomnogram to determine their apnea and hypopnea indices, (A + H)I, and oxygen saturation levels at the beginning of the study and then initiated 48 hours of ambulatory blood pressure monitoring, with data points collected every 30 minutes. Controls, which included one hypertensive subject, were all dippers. Nineteen OSAS subjects (48% of OSAS individuals) were systolic non-dippers and only 9 of them (22.5%) were diastolic non-dippers. We considered the following clinical variables as potential predictors of non-dipping: age, body mass index, respiratory disturbance index, years of reported loud snoring by bed partners, lowest oxygen saturation during nocturnal sleep, and percentage of sleep time spent with oxygen saturation below 90%. Multiple regression analyses indicated respiratory disturbance index as the only significant variable for systolic (p = 0.04) and diastolic (p = 0.03) blood pressure non-dipping. When we forced the following two nonsignificant variables into the model, they showed a very meager impact: number of years with reported loud snoring (p = 0.4 and p = 0.5, respectively for systolic and diastolic blood pressure non-dipping) and age (p = 0.5 and p = 0.6). The calculated model explained only a low percentage of the variance with an r2 of 0.25 and 0.26 for systolic and diastolic blood pressure non-dipping, respectively. Analysis of hypertension/normotension and dipping/non-dipping failed to show a significant relationship in the studied population. Fifty percent of the normotensive OSAS subjects were non-dippers and 43% of the hypertensive OSAS subjects were also non-dippers. We found a relationship between increasing respiratory disturbance index and increasing average 24-hour systolic blood pressure only when OSAS subjects were non-dippers and hypertensive.

Purification and properties of the 26S proteasome from the rat brain: evidence for its degradation of myelin basic protein in a ubiquitin-dependent manner

A ubiquitin(Ub)/ATP-dependent proteolytic complex (26S proteasome) was highly purified from the rat brain. The brain 26S proteasome consisted of 22-110 kDa subunits characteristic of the typical 26S proteasome on the basis of SDS-PAGE. The two-dimensional PAGE (NEPHGE and SDS-PAGE) pattern revealed that the pI values and molecular masses of the brain 26S proteasome subunits were similar to those of the subunits of 26S proteasomes purified from the rat liver and skeletal muscles. The enzymatic properties of the brain 26S proteasome were similar to those of the liver complex and also to the Ub-conjugate degrading activity in the cerebral cortex extract. Furthermore, it was found that the brain 26S proteasome was capable of degrading the myelin basic protein in a Ub-dependent manner. These results indicate that the brain contains the Ub-conjugate-degrading 26S proteasome, the subunit composition of which appears similar to those of the other tissues, and that the myelin basic protein may be a candidate physiological substrate for the brain 26S proteasome.

Upper airway resistance syndrome, nocturnal blood pressure monitoring, and borderline hypertension

Upper airway resistance syndrome (UARS) is a sleep-disordered breathing syndrome characterized by complaints of daytime fatigue and/or sleepiness, increased upper airway resistance during sleep, frequent transient arousals, and no significant hypoxemia. Of a population of 110 subjects (58 men) diagnosed as having UARS, we investigated acute systolic and diastolic BP changes seen during sleep in two different samples. First, six patients from the original subject pool were found to have untreated chronic borderline high BP, and were subjected to 48 h of continuous ambulatory BP monitoring before treatment and another 48 h of BP monitoring 1 month after the start of nasal-continuous positive airway pressure (N-CPAP) treatment. Five of six subjects used their equipment on a regular basis and had their chronic borderline high BP completely controlled. No change in BP values was seen in the last subject, who discontinued N-CPAP after 3 days. A second protocol investigated seven normotensive subjects drawn from the initial subject pool. Continuous radial artery BP recording was performed during nocturnal sleep with simultaneous polygraphic recording of sleep/wake variables and respiration. BP changes were studied during periods of increased respiratory efforts and at the time of alpha EEG arousals. Increases in systolic and diastolic BP were noted during the breaths with the greatest inspiratory efforts without significant hypoxemia. A further increase in BP was noted in association with arousals. Three of these subjects also underwent echocardiography during sleep, which demonstrated a leftward shift of the interventricular septum with pulsus paradoxus in association with peak end-inspiratory esophageal pressure more negative than -35 cm H2O. Our study indicates that, in the absence of classic apneas, hypopneas, and repetitive significant drops in oxygen saturation (below 90%), repetitive increases in BP can occur as a result of increased airway resistance during sleep. It also shows that, in some patients with both UARS and borderline high BP, high BP can be controlled with treatment of UARS. We conclude that abnormal upper airway resistance during sleep, often associated with snoring, can play a role in the development of hypertension.

Rodent complementation group 8 (ERCC8) corresponds to Cockayne syndrome complementation group A

US31 is a UV-sensitive mutant cell line (rodent complementation group 8) derived from a mouse T cell line L5178Y. We analyzed removal kinetics for UV-induced cyclobutane pyrimidine dimers and (6-4) photoproducts in US31 cells using monoclonal antibodies against these photoproducts. While nearly all (6-4) photoproducts were repaired within 6 h after UV-irradiation, more than 70% of cyclobutane pyrimidine dimers remained unrepaired even 24 h after UV-irradiation. These kinetics resembled those of Cockayne syndrome (CS) cells. Since US31 cells had a low efficiency of cell fusion and transfection, which hampered both complementation tests and gene cloning, we constructed fibroblastic complementation group 8 cell line 6L1030 by fusion of US31 cells with X-irradiated normal mouse fibroblastic LTA cells. Complementation tests by cell fusion and transfection using 6L1030 cells revealed that rodent complementation group 8 corresponded to CS complementation group A.