Childhood narcolepsy in North China

STUDY OBJECTIVES

The purpose is to report the results of an effort to diagnose children with narcolepsy in a pediatric referral clinic.

DESIGN

Between September 1998 and December 1999, a program was implemented to emphasize recognition of childhood narcolepsy. Patients underwent brain computed tomography (CT) scan and magnetic resonance imaging (MRI) testing. All children received a MSLT test following a routine night's sleep, and serological HLA typing for HLA DR2. Three who reported occasional snoring also underwent nocturnal PSG prior to the MSLT.

SETTING

N/A.

PATIENTS OR PARTICIPANTS

N/A.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

29 (21 male, 8 female) children were identified with sleepiness and cataplexy. There was no evidence for brain functional or structural disease or for drug use. Sleep paralysis was elicited in 41%; hypnagogic hallucinations, in 59%. Psychosocial problems including emotional irritability and social isolation were present in 93% of the patients. Mean sleep latency on MSLT was 2.0+/-1.3 minutes; sleep-onset rapid eye movement (SOREM) occurred during 2/5 naps in 28 of 29 patients and 3/5 in 26/29 patients. The average number and latency of SOREM episodes were 4.2+/-0.9 episodes and 4.0+/-1.7 minutes, respectively. In those with snoring, a nocturnal PSG did not disclose sleep apneas/hypopneas. All patients but one were HLA DR2 positive. The estimated clinic incidence was 0.04%.

CONCLUSIONS

A program for recognition in a referral neurology clinic combined with an availability of the MSLT and HLA testing resulted in the new identification in North China of a number of children with narcolepsy syndromes.

[Structural and functional study of prokaryotic enhancer-like element VV1 from vaccinia virus]

Enhancer VV1 (about 283 bp) is selected as the target to analyze its structure and function systemically. Stepwise deletion experiment is used to identify the functional domain of VV1 element. The results suggest that the 20 bp at 5' terminal and 20 bp at 3' terminal are important to the activity of VV1, for without either of them its activity decreased greatly. Furthermore, the 30-50 bp at 5' terminal is essential to its activity, without which will lead to complete loss of its activity. By random mutagenesis assay it is found that base mutation can regulate the activity of enhancer VV1 positively or negatively. The more the activities of mutants descend, the more mutations take place. For singlebase mutation, the activities change relatively little, and most of the mutations always occur in the 50 bp at the 5' terminal.

[Changes of microarousal in OSAS patients during CPAP]

OBJECTIVE

To study the mechanism of microarousal, its clinical meaning and value in the diagnosis and treatment of sleep apnea-hypopnea syndrome (SAHS).

METHODS

270 snorers (218 men, 58 women) mean aged 48 years underwent standard polysomnography (PSG), from which AHI, sleep latency (SL), number of oxygen desaturation >/= 4% per hour (ODI(4)) and microarousal index (MAI) were calculated. The overnight PSG recordings were also repeated during nCPAP in 28 patients, who have filled in the Epworth Sleep Score (ESS) before and after the treatment to evaluate the improvement of daytime sleepiness.

RESULTS

Of the 270 snorers, there were 247 SAHS patients. Their AHI, ODI(4), MAI and SL were (43 +/- 27)/h, (44 +/- 23)/h, (29 +/- 16)/h and (12 +/- 17) min, respectively. AHI and MAI, ODI(4) and MAI were both positively correlated (r = 0.38, both P < 0.001). MAI and SL were negatively correlated (r = -0.15, P = 0.02), while AHI and SL, ODI(4) and SL were not correlated (r = -0.09, -0.02, P > 0.1). Of the 28 patients after CPAP, ODI(4) decreased from (48 +/- 25)/h to (4 +/- 9)/h, MAI decreased from (27 +/- 18)/h to (15 +/- 9)/h. The ESS and SL indicated that subjective and objective sleepiness improved.

CONCLUSIONS

Microarousals with at least 3 seconds EEG changes can be scored by computerized EEG analysis. MAI can reflect the severity of daytime sleepiness. MAI is complementary to AHI in the diagnosis and treatment of SAHS. After nCPAP, the patients' MAIs decreased and daytime sleepiness improved.

In situ RT-PCR detection of inducible nitric oxide synthetase gene expression in lung during endotoxemia in rabbits

OBJECTIVE

To detect the location of inducible nitric oxide synthetase (iNOS) protein and mRNA in lung during endotoxemia in rabbits.

METHODS

Northern blotting was performed before, 1 hour and 5 hours after the intravenous administration of lipopolysaccharide (LPS) in rabbits. Immunohistochemical analysis (IA), in situ hybridization and in situ reverse transcription-polymerase chain reaction (in situ RT-PCR) were also performed in lung sections.

RESULTS

iNOS mRNA expression was found using Northern blotting in lung 5 hours after LPS injection, while it was not found in control. The positive stain was found only in macrophages in lung 5 hours after LPS injection by standard hybridization and IA; while by in situ RT-PCR, the amplification products were found in macrophages, airway epithelial cells, vascular endothelial cells, smooth muscle cells and leukocytes, in addition to macrophages distributed abundantly throughout the lung. The signal was absent in control or samples.

CONCLUSIONS

Using an in situ RT-PCR technique, iNOS expression was not only observed in macrophages but also in many other kinds of cells in lung during endotoxemia in rabbits. This suggests that in situ RT-PCR is much more sensitive than in situ hybridization, and can be used to examine genes with low expression.

Physical mapping of the barley stem rust resistance gene rpg4

The barley stem rust resistance gene rpg4 was physically and genetically localized on two overlapping BAC clones covering an estimated 300-kb region of the long arm of barley chromosome 7(5H). Initially, our target was mapped within a 6.0-cM region between the previously described flanking markers MWG740 and ABG391. This region was then saturated by integrating new markers from several existing barley and rice maps and by using BAC libraries of barley cv. Morex and rice cv. Nipponbare. Physical/genetic distances in the vicinity of rpg4 were found to be 1.0 Mb/cM, which is lower than the average for barley (4 Mb/cM) and lower than that determined by translocation breakpoint mapping (1.8 Mb/cM). Synteny at high resolution levels has been established between the region of barley chromosome 7(5H) containing the rpg4 locus and the subtelomeric region of rice chromosome 3 between markers S16474 and E10757. This 1.7-cM segment of the rice genome was covered by two overlapping BAC clones, about 250 kb of total length. In barley the markers S16474 and E10757 genetically delimit rpg4, lying 0.6 cM distal and 0.4 cM proximal to the locus, respectively.

In-situ sampling and separation of RNA from individual mammalian cells

In this investigation RNA was directly sampled and separated at the single-cell level (without extraction) by capillary electrophoresis (CE). Laser-induced fluorescence (LIF) was employed to detect ethidium bromide-labeled RNA molecules under native conditions. Hydroxypropylmethylcellulose was used as a matrix for molecular sieving. Additives to the polymer solution included poly(vinylpyrrolidone) to eliminate the electroosmotic flow and mannitol to enhance the separation. Peak identities were confirmed as RNA by enzymatic treatment with RNase I. The individual Chinese Hamster Ovary (CHO-K1) cells were injected into a capillary and the cells were lysed online with sodium dodecyl sulfate (SDS) solutions before running electrophoresis. Low molecular mass (LMM) RNAs as well as larger fragments (tentatively identified as 18S and 28S ribosomal RNA by comparison with the literature) were detected with this system, which corresponds to a detected amount of approximately equals 10-20 pg of RNA/cell. A Proteinase K study showed that proteins incorporated with RNA molecules were eliminated by SDS treatment and thus did not influence the migration of RNA. Experiments were also performed with this technique to detect nucleic acid damage. Changes in the peak pattern were detected in the cells treated with hydrogen peroxide, which meant that strand breaks occurred in DNA and RNA. It was found that 60 mM caused the most severe damage to the nucleic acids.

Inheritance of ventilatory behavior in rodent models

Studies in mice and rats support the hypothesis that ventilation and its components (frequency and tidal volume) are determined to a significant extent by genetic mechanisms. The question can no longer be 'is there a genetic effect?' but rather 'how strong is the genetic component?' and 'what genes are involved?' The computational analyses of selectively bred animals now offer powerful tools to begin to dissect the genetic factors that track with ventilatory traits. Control of the conditions in the colony and in the laboratory are keys to reducing the environmental 'noise' and increasing the likelihood of detecting gene loci that correlate quantitatively with phenotype values before and during the response to chemosensory challenges. Knowing the chromosomal location of genes for ventilation will then permit the identification of proteins systems responsible for the structural and functional components for respiration.

[Some geographical features of the location and gene mutation of cancers occurring in Nantong City, China]

OBJECTIVE

To detect the location and geographical features of gene mutation of the cancer based on 30,709 clinical tumor biopsies.

METHODS

Thirty thousand seven hundred and nine cases of tumor biopsy materials were collected from the Department of Pathology of Nantong Cancer Hospital between June 1974 and December 1987. The address of the village and county of patients was collected and statistical analysis was performed on data from lab examination. DNA sequencing of 31 cases of hepatocellular carcinoma (HCC) was performed at the Department of Pathology of the Medical College of Tokyo University, Japan.

RESULTS

The data suggested that different carcinomas occurred predominantly in some districts and the frequency and type of mutation of the P53 gene in the HCC were different in different districts.

CONCLUSION

It seems that based on the clinical biopsy materials, carcinomas of the uterus cervix (CC) and nasopharynx tend to occur in some districts of Nantong City and the frequency and type of mutation of the gene P53 of the HCC were different in different districts. The reason for this is not understood and further study will be done.

[Functional and structural study of the prokaryotic enhancer-like element VV16 from vaccinia virus genome]

An enhancer-like element VV16 from Vaccinia virus genome DNA was obtained by using the plasmid with CAT reporter gene. Sequence analysis showed the element of 112 bp is a part of the DNA-dependent RNA polymerase, polyA polymerase and DNA polymerase (RPO30 gene). It contains 4 AT-rich regions. Detection of beta-galactosidase activity showed that VV16 in the positive direction can increase the activity 9.0 times and VV16 in the negative direction can increase 4.1 times. The RNA dot blotting confirmed the enhancing activity of the element are on the transcription level. DNA deletion experiment indicated the sequences of 10 bp at the 5' end and 12 bp at the 3' end in the element are important to its function and the sequence from nt76 to nt82 is essential to its activity.

A rapid and sensitive reporter gene that uses green fluorescent protein expression to detect chemicals with estrogenic activity

A reporter gene sequence was constructed within a eukaryotic expression vector. The altered plasmid contained 2 sequential estrogen response elements (ERE) coupled to a human phosphoglycerate kinase (PGK) promoter inserted upstream from a cDNA sequence encoding enhanced green fluorescent protein (GFP) with a 3'-polyadenylation signal. The plasmid was linearized and transfected into MCF-7 cells, a human breast cancer-derived line that expresses the estrogen receptor (ER). No selectable marker was present in the plasmid, requiring stably transfected cells to be selected by fluorescence-activated cell sorting based on GFP expression after the cells were treated with 10(-9) M 17beta-estradiol (E2). Stably transfected MCF-7 cells (MCF7-ERE) exhibited 2000-3000 times more fluorescence at 488 nm excitation and 512 nm emission than non-transfected cells. MCF7-ERE cells exhibited a linear increase in GFP expression induced over a range of 10(-12) M E2, a concentration giving 2 times the background expression, to maximal expression at 3 x 0(-10) M E2. From the maximal level, GFP expression plateaued, and then declined when E2 was increased to the highest concentration tested, 10(-7) M. 4-Hydroxytamoxifen (TFN-OH) treatment of cells produced a dose-dependent inhibition of E2-induced GFP expression, indicating the interaction of ER in the regulation of GFP gene expression. A series of estrogenic chemicals were evaluated for their capacity to induce GFP expression in MCF7-ERE cells, showing induced expression of GFP at concentrations 2-4 log units higher than the E2 concentration giving maximal GFP expression. The ERE-PGK-GFP reporter gene system is capable of rapid GFP expression in the presence of low concentrations of E2, and of quantifying estrogenicity of chemicals compared with a standard curve of the natural ligand, 17beta-estradiol.

Molecular cloning and expression patterns of mouse cartilage oligomeric matrix protein gene

OBJECTIVE

To develop transgenic mice harboring mutations in the COMP gene as animal models for pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED), autosomal dominant disorders characterized by early onset osteoarthritis and epiphyseal abnormalities. As a first step in generating a mouse model for COMP mutations, we have cloned the cDNA of mouse COMP and examined its tissue expression pattern.

DESIGN

Total mRNA was isolated from the skeletal tissues of newborn C57BL/6j mice and used as a template for oligo(dT) first-strand cDNA synthesis. The cDNA was used for PCR amplification of COMP using three oligonucleotide primer pairs designed from the published rat COMP cDNA sequence. Nested PCR was used to complete the sequence between the amplified fragments. The entire cDNA was sequenced and the expression pattern of the corresponding transcripts examined by Northern hybridizations.

RESULTS

A full-length COMP cDNA was isolated. Analysis showed that the entire translated region of the mouse COMP gene is 2268 bp and the derived amino acid sequence shows 90% homology to human COMP. Of eight adult mouse non-cartilage tissues tested, COMP expression was detected only in testis.

Protective effect of melatonin on neural cells against the cytotoxicity of oxyradicals

OBJECTIVE

To investigate the exact mechanism of melatonin to prohibit the apoptosis of neural cells induced by various kinds of cytotoxic agents.

METHODS

We used the methods of phase contrast microscopy, MTT assay and hoechst dye staining to check this mechanism in SKNSH and U251 cell lines.

RESULTS

Both 2 mmol/L H2O2 and 0.5 micromol/L amyloid beta-protein (Abeta) induce these two cell lines die via apoptosis. Either melatonin or glutathione can significantly protect both cell lines. The protective effect of 10 micromol/L melatonin is as same as that of 60 micromol/L glutathione.

CONCLUSION

Melatonin can partly inhibit the cytotoxicity of H2O2 and Abeta through its role as a free radical scavenger.

[Expression, purification and identification of human IFN-alpha 2 b/HBV Pre S2 fusion protein]

OBJECTIVE

To express a fusion protein of human interferon-a2b and HBV Pre S2 in E.coli for the purpose of investigating anti-HBV immunomodulatory protein.

METHODS

Human interferon-a2b and HBV Pre S2 encoding genes were amplified from plasmid templates through PCR, then fused and cloned into plasmid pBV220 through engineering technique to generate expression plasmid pBV-IFN-Pre S2. The plasmid was transfected into E. coli to produce fusion protein. RP-HPLC and ion-exchange chromatography were employed to purify fusion protein.

RESULTS

27 kDa fusion protein was expressed up to 15% of total bacterial protein in E. coli. After purification, the purity of fusion protein reached 95% of total protein. Anti-viral assay showed that IFN-Pre S2 protein induced a VSV-resistant activity of 1.25 x 10(8) lU/mg protein in Wish cell line, similar to the bioactivity of original recombinant human IFN-alpha 2b. ELISA data showed that IFN-Pre S2 protein had antigenicities of both human IFN-alpha 2b and HBV Pre S2. In addition, fusion protein showed the feature of binding to polymeric human serum albumin (PHSA).

CONCLUSIONS

The bifunctional fusion protein was efficiently expressed in E. coli. The work provided initial evidence for studying PHSA-receptor-targeting IFN-alpha 2b,which might have potential application for the treatment of HBV infection.

[Distribution and transferring of carbon in kast soil system of peak forest depression in humid subtropical region]

Taking Guilin Yaji Karst Experiment Site as an exemple and with the methods of field monitoring and laboratory analysis, this paper studied the distribution and transferring of carbon in the karst soil system of peak forest depression in the humid subtropical region of China. The carbon pools in biomass, litters and soil organic matter(SOM) and their mobility as expressed by oxidizability and decomposition rate of SOM, the concentration of soil CO2 and the emission rate of CO2 from soil were investigated. The mobile carbon pool in the system supplied a rich source of CO2, which drived the karst process. When active karst process happened in Spring and Summer, over 60% of carbon in the output water was derived from soil CO2, as traced by delta 13 C distribution in the system. Therefore, owing to the carbon transfer in the pathway of air-plant-soil-water, karst process took place rather under soil-rock-water interface than under air-rock-water interface. Thus, the epigenetic karst process was driven and accelerated by soil as an interface of carbon environmental geochemistry.

[Functional and structural analysis of a prokaryotic enhancer-like element in Escherichia coli MC1061 strain]

Cat and lacZ genes were used as reporter gene and three prokaryotic enhancer-like element (MC2, MC8 and MC9) were identified in the genomic DNA of MC1061 strain. All three fragments can improve the expression of lacZ gene by 2-5 times with the orientation independence. The results of in vivo transcription and Dot blot hybridization assays suggested that MC8 regulated the expression of lacZ at transcription level. Stepwise deletion expreriments showed the functional domain of MC8 located at 450-950 bp, and in regions 450-600 bp and 840-950 bp contain at least one functional loci. Sequence data indicated three are 3 A + T rich sections in MC8, 2 of them are in the functional loci.

Sequence analysis of a rice BAC covering the syntenous barley Rpg1 region

In the course of map-based cloning of the barley stem rust resistance gene Rpg1, we identified a rice bacterial artificial chromosome (BAC) containing the Rpg1 flanking markers. Based on the excellent gene order colinearity between barley and rice in this region, we expected that this rice BAC would contain the barley Rpg1 homologue. In order to identify the putative rice homologue, we sequenced ca. 35 kb of the rice BAC at random and then an additional 33 kb of contiguous sequence between the two most closely spaced Rpg1 flanking markers. Sequence analysis revealed a total of 15 putative genes, 5 within the 33-kb contiguous region. A rice Rpg1 homologue was not identified, although a gene encoding a hypothetical polypeptide with similarity to a membrane protein could not be eliminated as a candidate. Surprisingly, four of the genes identified in the 33-kb contiguous rice sequence showed a high degree of similarity with genes on Arabidopsis chromosome 4. The genome regions harboring these genes showed some relatedness, but many rearrangements were also evident. These data suggest that some genes have remained linked even over the long evolutionary separation of Arabidopsis and rice, as has also been reported for mammals and invertebrates.

Effects of sodium hyaluronate on experimental osteoarthritis in rabbit knee joints

The aim of this study was to examine the effects of intraarticular administration of hyaluronan (HA) on cartilage degradation. Using a partial menisectomy model of osteoarthritis (OA) in the rabbit knee, the authors investigated the catabolic and anabolic changes induced by intraarticular injection of HA. To analyze anabolic changes, the authors assessed cell proliferation by measuring [3H] thymidine uptake, and proteoglycan biosynthesis by noting [35S] sulfate incorporation. For catabolic changes, messenger ribonucleic acid (mRNA) expression of interstitial collagenase (MMP-1), stromelysin-1 (MMP-3), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in cartilage and synovium were detected with reverse transcriptase polymerase chain reaction (RT-PCR). Of significance for blocking the development of early OA in chondrocytes was the finding that total proteoglycan synthesis in the HA treatment group was significantly higher than in the controls. At the mRNA level in cartilage and synovium, HA inhibited MMP-3 and TIMP-1 production in the same way in the HA treatment group, while not affecting MMP-1 production. Thus it can be concluded that HA affects cartilage catabolism and anabolism to prevent the progress of OA.

Different frequencies of p53 codon-249 hot-spot mutations in hepatocellular carcinomas in Jiang-su province of China

Environmental carcinogens often induce specific mutations in the p53 gene, apparent in tumors. The relation between aflatoxin B1 (AFB1 )-related hepatocellular carcinomas (HCCs) and hot spot at codon 249 of the p53 gene has received a great deal of attention, but its significance is still controversial. To clarify this problem, we analyzed the p53-mutational status of HCCs in Jiang-su province in China, where AFB1 contamination of the staple food significantly differs between the northern and southern parts (prominent only in the latter), while other conditions are quite similar. Background liver status and mutations in exons 5 to 8 of p53 in a total of 31 cases were divided approximately equally between the 2 areas. In all, 15 tumors exhibited a total of 17 mutations in the p53 gene; 9 cases from the southern part of the province had the hot-spot mutation at codon 249 (9/16, 56%), but only one case from the northern part (1/15, 8%). These results suggest that AFB1 contamination may correlate with codon-249 mutations in HCC.

Different frequencies of p53 codon-249 hot-spot mutations in hepatocellular carcinomas in Jiang-su province of China

Environmental carcinogens often induce specific mutations in the p53 gene, apparent in tumors. The relation between aflatoxin B1 (AFB1 )-related hepatocellular carcinomas (HCCs) and hot spot at codon 249 of the p53 gene has received a great deal of attention, but its significance is still controversial. To clarify this problem, we analyzed the p53-mutational status of HCCs in Jiang-su province in China, where AFB1 contamination of the staple food significantly differs between the northern and southern parts (prominent only in the latter), while other conditions are quite similar. Background liver status and mutations in exons 5 to 8 of p53 in a total of 31 cases were divided approximately equally between the 2 areas. In all, 15 tumors exhibited a total of 17 mutations in the p53 gene; 9 cases from the southern part of the province had the hot-spot mutation at codon 249 (9/16, 56%), but only one case from the northern part (1/15, 8%). These results suggest that AFB1 contamination may correlate with codon-249 mutations in HCC.

Application of capillary nongel sieving electrophoresis for gene analysis

Capillary electrophoresis (CE) has proved to be a strong tool for DNA analysis and has found abundant applications in the fields of restriction fragment sizing, mutation screening, polymerase chain reaction (PCR) product characterizing and forensic identifying. CE may be the main alternative to slab gel electrophoresis. Capillary nongel electrophoresis is the most favorable mode when aiming for this purpose because of its advantages of long lifetime, easy operation, good reproducibility, and low expense. In this paper, a new kind of sieving matrix, with mannitol as the additive for capillary electrophoresis, as well as related methods and their application for gene analysis were reported. Nine DNA fragments amplified by multiplex PCR from a normal dystrophin gene were well separated by this system. Three different deletions were found in Duchenne muscular dystrophy (DMD) patients. Three to four copies of the sex-determination region of the Y chromosome (SRY) gene, as well as the phenylalanine hydroxylase (PAH) gene, could be detected in mixed samples. The frequencies of short tandem repeats (STR) in PAH genes was analyzed in 61 normal Chinese individuals and 6 phenylketonuria families. One case of prenatal gene diagnosis was performed. By using this matrix, CE coupled with reverse transcription PCR (RT-PCR), the analysis of the alternative splicing expression pattern of the fragile X mental retardation 1 (FMR1) gene in adult lung tissue was achieved.

[The role of breathing control disorder in the development of carbon dioxide retention in patients with obesity hypoventilation syndrome]

OBJECTIVE

To define the role of breathing control in the pathogenesis of carbon dioxide (CO(2)) retention in patients with obesity hypoventilation syndrome.

METHODS

10 obese obstructive sleep apnea syndrome (OSAS) patients were studied. They were separated according to their waking arterial partial pressure of CO(2) (PaCO(2)), 5 being eucapnic and 5 hypercapnic. Both groups had similar body mass index, apnea hypopnea index and normal lung function. The hypoxic (Delta P(0.1)/Delta SaO(2), Delta V(E)/Delta SaO(2)) and the hypercapnic response (Delta P(0.1)/Delta PaCO(2), Delta V(E)/Delta PaCO(2)) were tested before and during continuous positive airway pressure (CPAP) treatment (at 2, 4, 6 weeks).

RESULTS

Compared with the eucapnic patients, all the hypercapnic patients had lower Delta P(0.1)/Delta SaO(2) [(-0.04 +/- 0.02) cmH(2)O% vs (-0.14 +/- 0.03) cmH(2)O%], Delta V(E)/Delta SaO(2) [(-0.17 +/- 0.04) L x min(-1)% vs (-0.34 +/- 0.04) L x min(-1)%], Delta P(0.1)/Delta PaCO(2) [(0.23 +/- 0.1) cmH(2)O/mm Hg vs (0.49 +/- 0.1) cmH(2)O/mm Hg], Delta V(E)/Delta PaCO(2) [(1.32 +/- 0.7) L x min(-1) x mm Hg(-1) vs (2.18 +/- 0.81) L x min(-1) x mm Hg(-1)] and the Delta P(0.1)/Delta SaO(2), Delta V(E)/Delta SaO(2) were also lower than the normal value. After treatment with CPAP, the hypercapnic and the hypoxic response of the hypercapnic patients increased gradually, at about 4 approximately 6 week, both of them increased to the normal range, PaCO(2) showed a complete return to eucapnia, their weight were unchanged.

CONCLUSION

The depressed breathing control play an important role in the development of CO(2) retention in OSAS patients, and the disorder in breathing control may be secondary to hypoxia, hypercapnia and sleep disorder related to the OSAS.

[Utility of nocturnal oximetry for case finding in patients with suspected sleep apnea syndrome]

OBJECTIVE

Pulse oximeter is a useful screening device for SAS. We studied whether measurement of SaO2 could identify patients with SAS and evaluate the severity of SAS.

METHODS

174 snorers were assessed clinically and then underwent formal PSG and oximetry test at the same time. From the oximetry data, the percentage of time spent at SaO2 below 90% (SIT90%), waking SaO2(H SaO2%), the lowest SaO2(L SaO2%) during sleep, the mean SaO2(M SaO2%) and the number of oxygen desaturation > or = 4% per hour (DI4) were calculated. We also divided 100 cases among them into four groups by AHI, which were G0(AHI < 5), G1(AHI 5-19), G2(AHI 20-39), G3(AHI > or = 40), and evaluated whether the SIT90, ISaO2, MSaO2 and DI4 are different among the four groups.

RESULTS

There was an statistically significant correlation (r = 0.91 P < 0.001) between DI4 and AHI. DI4 > or = 5 per hour identified patients with AHI > 5 with a sensitivity of 94%; DI4 > or = 15 per hour identified patients with AHI > 5 with a specificity of 98%, and for patients with AHI > or = 20, the sensitivity was 100%. The SIT90 and DI4 were significantly different among the four groups (P < 0.01).

CONCLUSIONS

Oximetry with DI4 < 5 practically excludes clinically significant SAS, and DI4 > or = 15 identified almost all of them. SIT90 and DI4 could be used as parameters in evaluating the severity of SAS.

Pteridine analysis in urine by capillary electrophoresis using laser-induced fluorescence detection

Pteridines are a class of compounds excreted in urine, the levels of which are found to elevate significantly in tumor-related diseases. For the first time, we have developed a method, based on high-performance capillary electrophoresis (HPCE) and laser-induced fluorescence (LIF) detection, to monitor the pteridine levels in urine. HPCE provides better separation than high-performance liquid chromatography and the LIF detector enables us to detect minute amounts of pteridines in body fluid. Eight different pteridine derivatives were well separated in 0.1 M Tris-0.1 M borate-2 mM EDTA buffer (pH 8.75) using a 60-cm fused-silica capillary (50-micron i.d., 35-cm effective length), six of which were detected and characterized in urine samples from normal persons and different cancer patients. The detection limits of these pteridines are under 1 x 10(-10) M. The levels of neopterin, pterine, xanthopterin, and pterin-6-carboxylic acid were found to be significantly elevated in urine excreted by cancer patents, while the level of isoxanthopterin dropped in these patients. No significant change of biopterin level was found between healthy individuals and cancer patients. This method can be used in clinical laboratories either for cancer monitoring or for precancer screening.

Experience with the rectus abdominis myocutaneous flap with vascularized hard tissue for immediate orbitofacial reconstruction

For a considerable tissue defect of the orbitofacial region after skull base or head and neck tumor en bloc extirpation, we have developed the "flying buttress" technique using the vascularized hard tissue rather than the multi-stage operative method using bone graft or alloplastic materials. The procedure reconstructs the inferior orbital rim and the zygomatic prominence--flying buttresses bridging transversely in a missing face--with free flap coverage, simultaneously in the primary surgery so that the bony structure is maintained for years and ptosis of a large flap is minimized. We prefer to use the rectus abdominis myocutaneous flap for tissue restoration and two types of vascularized hard tissue: the costal cartilages combined with the flap and the temporalis muscle-pedicled calvarial bone. Representative cases are illustrated and the technique is detailed.