Changes in peak inspiratory flow rate and peak airway pressure with endotracheal tube size during chest compression / 世界急诊医学杂志（英文）

@#BACKGROUND: Adequate airway management plays an important role in high-quality cardiopulmonary resuscitation (CPR). Airway management is usually performed using an endotracheal tube (ETT) during CPR. However, no study has assessed the effect of ETT size on the flow rate and airway pressure during CPR. METHODS: We measured changes in peak inspiratory flow rate (PIFR), peak airway pressure (Ppeak), and mean airway pressure (Pmean) according to changes in ETT size (internal diameter 6.0, 7.0, and 8.0 mm) and with or without CPR. A tidal volume of 500 mL was supplied at a rate of 10 times per minute using a mechanical ventilator. Chest compressions were maintained at a constant compression depth and speed using a mechanical chest compression device (LUCAS2, mode: active continuous, chest compression rate: 102±2/minute, chest compression depth 2–2.5 inches). RESULTS: The median of several respiratory physiological parameters during CPR was significantly different according to the diameter of each ETT (6.0 vs. 8.0 mm): PIFR (32.1 L/min [30.5–35.3] vs. 28.9 L/min [27.5–30.8], P<0.001), Ppeak (48.84 cmH2O [27.46–52.11] vs. 27.45 cmH2O [22.53–52.57], P<0.001), and Pmean (18.34 cmH2O [14.61–21.66] vs.13.66 cmH2O [8.41–19.24], P<0.001). CONCLUSION: The changes in PIFR, Ppeak, and Pmean were related to the internal diameter of ETT, and these values tended to decrease with an increase in ETT size. Higher airway pressures were measured in the CPR group than in the no CPR group.

Analysis of Upper Eyelid Fat Pad Changes with Aging and Body Mass Index in Korean

PURPOSE: To evaluate differential changes in the central and nasal fat pads of the upper eyelid associated with aging and the effect of body mass index in Koreans. METHODS: Using a standardized scale, the volume grade of the central and nasal fat pads was graded from 0 to 3 (0 for depressed, 1 for flat, 2 for mildly protruded, and 3 for markedly protruded) in normal adults, consisting of 20 males and 20 females from 30 years of age to 80 years of age. The body mass index was calculated for every patient through interviews using their height and weight. Statistical evaluations correlating age and body mass index with central and nasal fat pad changes were performed. Statistical evaluations correlating age with fat pad changes except for the effect of body mass index were performed. RESULTS: Except for the effect of body mass index, the central fat pad increased (r = -0.176, p = 0.007) and nasal fat pad decreased (r = 0.252, p < 0.001) with aging, which was statistically significant. CONCLUSIONS: With aging, the central fat pad increases and nasal fat pad decreases in the upper eyelid. Clinically, this finding has implications in cosmetic and functional upper eyelid blepharoplasty. In addition, the results may be useful to determine whether to conserve or remove the fat as well as the amount of fat removal during upper blepharoplasty.

Screening Wild Yeast Strains for Alcohol Fermentation from Various Fruits

Wild yeasts on the surface of various fruits including grapes were surveyed to obtain yeast strains suitable for fermenting a novel wine with higher alcohol content and supplemented with rice starch. We considered selected characteristics, such as tolerance to alcohol and osmotic pressure, capability of utilizing maltose, and starch hydrolysis. Among 637 putative yeast isolates, 115 strains exhibiting better growth in yeast-peptone-dextrose broth containing 30% dextrose, 7% alcohol, or 2% maltose were selected, as well as five alpha-amylase producers. Nucleotide sequence analysis of the 26S rDNA gene classified the strains into 13 species belonging to five genera; Pichia anomala was the most prevalent (41.7%), followed by Wickerhamomyces anomalus (19.2%), P. guilliermondii (15%), Candida spp. (5.8%), Kodamaea ohmeri (2.5%), and Metschnikowia spp. (2.5%). All of the alpha-amylase producers were Aureobasidium pullulans. Only one isolate (NK28) was identified as Saccharomyces cerevisiae. NK28 had all of the desired properties for the purpose of this study, except alpha-amylase production, and fermented alcohol better than commercial wine yeasts.

Changes in RNFL Thickness According to the Myopia in Patients with Glaucoma and Ocular Hypertension

PURPOSE: To evaluate the changes in retinal nerve fiber layer (RNFL) thickness according to the degree of myopia in patients with glaucoma and ocular hypertension. METHODS: Ninety-eight patients (165 eyes) diagnosed with glaucoma or ocular hypertension underwent optical coherence tomography (OCT) and scanning laser polarimetry using variable corneal compensation (GDx-VCC) to analyze the correlation between the degree of myopia and the thickness of the RNFL. A partial correlation coefficient analysis was performed to adjust for various factors such as age, laterality, intraocular pressure, and the mean deviation from visual field test, which can influence the RNFL thickness. RESULTS: The average, nasal, superior, and inferior sectorial RNFL thicknesses measured by OCT significantly decreased with increasing myopia (p<0.05). However, RNFL thickness measured by GDx-VCC was not significantly correlated with the degree of myopia. CONCLUSIONS: The RNFL thickness measured by OCT decreased with increasing myopia in eyes with glaucoma and ocular hypertension.

The Effects of Cheap Tinted Contact Lenses on Corneal Swelling and Ocular Surface Inflammation

PURPOSE: To evaluate the effects of cheap tinted contact lenses on corneal swelling and ocular surface inflammation, compared to hydrogel and silicone hydrogel contact lenses. METHODS: Forty eyes of 20 New Zealand white rabbits were randomly assigned to 4 groups. Two types of tinted contact lenses, hydrogel lenses, and silicone hydrogel lenses were each applied to 10 rabbit eyes. Corneal thickness and tear lactate dehydrogenase (LDH) activity were measured at 1 and 4 days after contact lens wear, and the inflammation of ocular surface was scored at 4 days after contact lens wear. The internal surface of the cheap tinted lens was examined with a scanning electron microscope to compare the surface quality between the tinted and non-tinted area. RESULTS: Although the corneal swelling of the silicone hydrogel lens group was significantly lower than the other 3 lens groups after contact lens wear (p0.1). Tear LDH activity at 1 and 4 days after contact lens wear showed no significant difference among the 4 groups (p>0.29). The scores of ocular surface inflammation in the 2 tinted contact lens groups were greater than the hydrogel and silicone hydrogel lens groups (p=0.03). The scanning electron microscope revealed the internal surface of the tinted area in the tinted contact lens was coarse and irregular though the surface of the non-tinted area was relatively smooth. CONCLUSIONS: Regarding corneal swelling and tear LDH activity, the cheap tinted contact lenses used in Korea were not significantly different from the common hydrogel contact lenses. However, tinted contact lenses showed a greater tendency to provoke ocular surface inflammation than other lenses. The coarse and irregular surface of the tinted area in the tinted contact lens appears to play a role in provoking severe ocular surface inflammation.

Inactivation of TPEF Gene by Aberrant Methylation in Hepatocellular Carcinoma

BACKGROUND: Abnormalities of genomic methylation patterns have been shown to play a role in the development of carcinoma, and the silencing of tumor suppressor genes is related to local de novo methylation. METHODS: Using methylation specific arbitrarily primed-Polymerase Chain Reaction (Ms AP-PCR), we identified a 322 bp sequence that contained a 5' un-translated and exon1 regions of the TPEF gene. To evaluate the inactivation of the TPEF gene through hypermethylation in hepatocellular carcinoma (HCC), we investigated the correlation between methylation patterns and TPEF expression in tumor tissues of human HCC and cell lines via a Combined Bisulfite Restriction Assay (CoBRA) and RT-PCR. RESULTS: A dense methylation pattern of the TPEF was detected in most cell lines, as well as in 10 of the 14 (71.4%) HCC tissues. In addition, loss of heterozygosity (LOH) from the TPEF gene was observed in 5 of the 14 (36%) HCC tissues. Furthermore, RT-PCR analysis revealed TPEF expression in 5 of 8 (62.5%) cell lines. Finally, treatment with a demethylating agent, 5-Aza- 2'-deoxycitidine (5-AzaC), increased the expression of TPEF mRNA. CONCLUSION: These results indicate that inactivation of the TPEF gene through hypermethylation may be a mechanism by which tumorigenesis occurs in HCC.

Clinical Usefulness of Laser Cystectomy

PURPOSE: To evaluate the usefulness of laser cystectomy for the treatment of patients with dacryocystitis and sump syndrome. METHODS: Thirteen patients (13 eyes) diagnosed with acute or chronic dacryocystitis, and nine patients (9 eyes) who developed sump syndrome after dacryocystorhinostomy from 2005 to 2006 underwent laser cystectomy and endonasal dacryocystorhinostomy. RESULTS: Pain and swelling around the orbit improved immediately after the operation in patients with acute dacryocystitis, and all symptoms of sump syndrome disappeared by 1 month postoperatively. Epiphora reduced in all patients. During the follow-up period, functional nasolacrimal duct obstruction occurred in one eye and membranous obstruction developed in two eyes. In these two eyes with membranous obstruction, revisional surgery was performed successfully. No recurrence of dacryocystitis was noticed. CONCLUSIONS: Laser cystectomy with endonasal dacryocystorhinostomy is a simple and effective treatment modality for patients with dacryocystitis and sump syndrome that minimizes the risk of recurrence.

Clinical Manifestations of Avellino Corneal Dystrophy Diagnosed by Non-invasive Genetic Test

PURPOSE: To introduce a new genetic method for the diagnosis of Avellino corneal dystrophy (ACD), which is non-invasive and can be easily performed on an outpatient basis, and to evaluate the relationship between the degree of corneal opacity and age or sex. METHODS: A genetic study was performed on 11 patients who had a specific corneal opacity by slit-lamp examination and on four normal patients by using a specific adhesive tape to obtain epidermal keratinocytes. Corneal dystrophy was diagnosed according to the genetic study. RESULTS: All 11 patients were confirmed as having heterozygous ACD. Heterozygous ACD patients were classified into five stages: trace, mild, moderate, severe, or very severe, based on slit-lamp photography status. Corneal stages had no relationship with sex (p=0.982), but the severity of ACD increased with age (p=0.005). CONCLUSIONS: A non-invasive sticker-type genetic study kit, the "U-gene test" is a good method to diagnose corneal dystrophy genetically. Avellino corneal dystrophy becomes more severe over time but has no relationship with sex.

Effects of Genistein and Daidzein on the Growth of Human Colon Cancer HCT-116 Cells

BACKGROUND: Genistein and daidzein are two major soybean isoflavones. They have received increasing attention because of their possible roles for cancer prevention. However, their mechanisms of action and molecular targets on the human colon cancer cells are not fully understood. METHODS: Human colon cancer HCT-116 cells were treated with genistein and daidzein to investigate their effects on the cell growth and this was analyzed with MTT assay. TUNEL assay and Hoechst33342 stain were carried out to identify apotosis. RESULTS: Daidzein was able to inhibit cell proliferation and induce apoptosis of the HCT-116 cells, but genistein didn't affect the cell growth. The ER antagonist ICI182780 didn't attenuate the antiproliferative and proapoptotic effects of daidzein: this means the effect of daidzein on the HCT-116 cells may not be dependent on the ER pathway. The other soybean isoflavone, genistein, attenuated the effects of daidzein on the HCT-116 cells and its mechanism should be elucidated. CONCLUSIONS: These data suggest that daidzein may act as a preventive agent on human colon cancer, and its mechanism of action doesn't involve the ER-dependent pathway.

Use of real-time quantitative PCR to identify high expressed genes in head and neck squamous cell carcinoma cell lines

Head and neck squamous cell carcinoma(HNSCC) is the sixth most common cancer among men in the developed world affecting the tongue, pharynx, larynx and oral cavity. HNSCC is thought to represent a multistep process whereby carcinogen exposure leads to genetic instability in the tissue and accumulation of specific genetic events, which result in dysregulation of proliferation, differentiation, and cell loss and the acquisition of invasive capacity. Despite therapeutic and diagnostic progress in oncology during the past decades, the prognosis of HNSCC remains poor. Thus it seems that finding a biological tumor markers which will increase the early diagnosis and treatment monitoring rates, is of paramount importance in respect to improving prognosis. In an effort to identify gene expression signatures that may serve as biomarkers, this study several genes were selected, such as H3,3A, S100A7, UCHL1, GSTP1, PAI-2, PLK, TGFbeta1 and bFGF, and used 7 HNSCC cell lines that were established various anatomical sites, and also 17 other cancer cell lines were used for control group using real-time quantitative RT-PCR and immunocytochemical analysis with a monoclonal antibody. In this study, S100A7 showed a clearly restricted occurrence in tongue originated cell line, and GSTP1 expression level in the pharynx originated cell line was very increased, relative to corresponding other cell lines. These results suggest that S100A7 and GSTP1 genes' expression can occur during tongue and pharynx originated head and neck tumorigenesis and that genetic change is an important driving force in the carcinogenesis process. This data indicate that S100A7 and GSTP1 expression pattern in HNSCC reflect both diagnostic clue and biological marker. And this is provides a foundation for the development of site-specific diagnostic strategies and treatments for HNSCC.

Genistein Induces G2/M Cell Cycle Arrest and Apoptosis in Rat Neuroblastoma B35 Cells; Involvement of p21(waf1/cip1), Bax and Bcl-2

BACKGROUND: The effect of genistein on different types of cells has been investigated. However, its effect on the nervous system is still unclear. The aim of the present work is to explore the effect of genistein on rat neuroblastoma B35 cells. METHODS: The effect of genistein on the proliferation of B35 cells, its cytotoxicity, the cell-cycle distribution, the ultra-structural changes and the induction of apoptosis were determined using MTT assay, LDH assay, Flow-cytometric analysis, transmission electron microscopy and Hoechst staining, respectively. Furthermore, Real-time quantitative RT-PCR and Western blotting were used to examine the transcriptional and post-translational alterations of the G2/M cell-cycle arrest marker cyclin-dependent kinase inhibitor p21(waf1/cip1) and the apoptosis-related genes after genistein treatment. RESULTS: Genistein significantly inhibits cell survival, slightly elevates the release of lactate dehydrogenase and induced apoptosis in B35 cells. Genistein increased the number of cells at S-phase and induced cells to accumulate at the G2/M phase. These G2/M arrested cells are associated with a marked up-regulation of p21(waf1/cip1) at both the mRNA and protein levels. We observed that genistein up-regulates pro-apoptotic Bax with concurrent down-regulation of the anti-apoptotic Bcl-2 protein. CONCLUSION: These observations suggest that the anticancer effect of genistein on B35 neuroblastoma cells is mediated through multiple cellular pathways including G2/M cell-cycle arrest and the induction of apoptosis.

Effects of Selective Cyclooxygenase-2 Inhibitor NS-398 Pretreatment on the Rat Spinal Cord after Contusion Injury

BACKGROUND: Secondary spinal cord injury (SCI) that follows an initial mechanical insult can exacerbate the overall damage, limit the restorative processes and eventually lead to an in- creased neurological deficit. We hypothesized that selective inhibition of cyclooxygenase-2 (COX-2) may decrease the delayed cell death, and so this will contribute to decreased level of the secondary injury. METHODS: The dorsal surface of the cord at the T9 level was subjected to weight drop impact using a 10 g rod. To block COX-2 activation, a selective COX-2 inhibitor (NS-398) was administered (5 mg/kg, i.p.) 15 min prior to SCI. The COX-1, COX-2, Caspase-3 and PGE2 expressions were measured by real time quantitative RT-PCR and fluorescence immunostaining. RESULTS: Many activated caspase-3 positive cells were observed at 6 h and they increased until 72 h after SCI. The expression of COX-2 peaked at 6 h after SCI, while the COX-1 expression was unaffected. The principal cells that showed a COX-2 expression were the neurons and microglia. Pretreatment with NS-398 caused a significant decrease in the expression of prostaglandin E2 and activated caspase-3 positive cells after SCI. CONCLUSION: These data suggest that COX-2 is one of the main factors related with the pathologic deficits from secondary SCI.

The Prevalence of Hematuria and Proteinuria in School Children in Seoul

BACKGROUND: Since 1998, mass urinary screening tests have been conducted in Korean school children. We analyzed the urinary screening test data gathered from the metropolitan city, Seoul, to identify the prevalence of persistent urine abnormalities. METHODS: The students were tested for hematuria and/or proteinuria using dipstick urinalysis. If the results were positive, the students were asked to visit a medical clinic to recheck urinalysis and in report their results. RESULTS: Among 1,337,210 students, who were screened with initial urinalysis, 10,871 students (proteinuria, 3,626 (0.27%); hematuria, 7,634 (0.57%); both, 389) were recommended to undergo second urinalysis in which 8,819 students (81.1%) did. Among them, 851 had persistent proteinuria and 2,618 had persistent hematuria. The results of the first urinalysis were scored based on the severity of hematuria and proteinuria from +1 to +4. Among all students 24.7% of the students who scored +1 and 40.4% who scored +3 proteinuria on the first test had persistent proteinuria, and 56.4% with both proteinuria and hematuria had persistent proteinuria on the second test. For hematuria, the more positive in the first test showed more prevalence of persistent hematuria. And 61.6% of students with both proteinuria and hematuia had persistent hematuria on the second test. CONCLUSION: The presence of both hematuria and proteinuria seemed to be a powerful predictor for persistent abnormal urine finding. And the more positive response in the first test was related to persistent abnormal finding. Therefore we should follow up closely for those students with positive findings.

DNA methylation of TPEF gene in head and neck squamous cell carcinoma cell lines

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide. The molecular mechanisms involved in the development and progression of these carcinomas are not well known. Abnormalities of genomic methylation patterns have been attributed a role in carcinogenesis and local de novo methylation at tumor suppressor loci was held to be involved in silencing of tumor suppressor genes. Using Ms APPCR, we previously isolated a hypermethylated fragment corresponded to the 5'end of TPEF gene from primary liver and lung cancer cells. To confirm the inactivation of TPEF gene by hypermethylation in HNSCC, we investigated correlation between methylation pattern and expression of TPEF in 10 HNSCC cell lines. In methylation analysis such as combined-bisulfite restriction analysis(COBRA) and bisulfite sequencing, only RPMI 2650 showed none methylated pattern and another 9 cell lines showed dense methylation. The TPEF gene expression level analysis using RT-PCR showed that these 9 cell lines had not or significantly low expression levels of TPEF as compared with RPMI 2650. In addition, the increase of TPEF reexpression by 5-AzaC as demethylating agent in 9 cell lines also indicated that TPEF expression was regulated by hypermethylation. These results of this study demonstrate that epigenetic silencing of TPEF gene by aberrant methylation could play an important role in HNSCC carcinogenesis.

The Characteristics of Cultural Conditions for the Mycelial Growth of Macrolepiota procera

Macrolepiota procera, one of edible mushrooms belongs to Agaricaceae of Basidiomycota, has a good taste and good medicinal value. As a preliminary study for the development of artificial cultivation method of edible mushroom, cultural characteristics of M. procera was investigated on various culture media under different environmental conditions. Mycelial growth was compared on culture media composed of various carbon and nitrogen sources, and C/N ratios. The optimal conditions for the mycelial growth were 30degrees C and pH 7. M. procera showed the rapid mycelial growth in the PDA media. The optimal carbon and nitrogen sources were maltose and glycine, respectively. The optimum C/N ratio was about 10 : 1 in case that 1% glucose was supplemented to the basal media as carbon source.

Culture Conditions Affecting the Optimal Mycelial Growth of Cystoderma amianthinum

Cystoderma amianthinum, one of edible fungi belongs to Agaricaceae of Basidiomycota, has a good taste and flavor. This study was carried out to obtain the basic informations for the optimum mycelial growth of C. amianthinum. The optimal conditions for the mycelial growth were 25degrees C and pH 5 in potato dextrose agar (PDA). C. amianthinum showed the favorable growth in the PDA and yeast malt extract agar (YMA). The favorable carbon and nitrogen sources promoting mycelial growth were fructose and histidine, respectively. The optimum C/N ratio was about 30 : 1 in case that 1% glucose was supplemented to the basal medium as a carbon source.

The Role of Inducible Nitric Oxide Synthase Following Spinal Cord Injury in Rat

Acute spinal cord injury (SCI) is two-step process that first involves the primary mechanical injury and then the secondary injury is induced by various biochemical reactions. Apoptosis is one of secondary SCI mechanisms and it is thought to play an important role for the delayed neuronal injury. The enhanced formation of nitric oxide (NO) via inducible nitric oxide synthase (iNOS) has been implicated in the pathogenesis of apoptosis in SCI. The level of .iNOS mRNA peaked at 6 hr after SCI and it declined until 72 hr after SCI in a rat model. Double-immunofluorescence staining revealed that iNOS positive cells were stained for ED-1, synaptophysin, GFAP, and oligodendrocyte marker. The terminal deoxynucleotidyl-transferase-mediated dUDP-biotin nick end-labeling (TUNEL) positive cell count was higher for the 72 hr post-SCI group than for the 24 hr post-SCI group. This cell count was also higher going in the caudal direction than in the rostral direction from the epicenter, and especially for the 72 hr group. Treatment with a selective iNOS inhibitor resulted in the reduction of TUNEL-positive cells at the lesion site. These findings suggest that nitric oxide generated by the iNOS of macrophages, neurons, oligodentrocytes, and astrocytes plays an important role for the acute secondary SCI that results from apoptotic cell death.

DNA Hypermethylation of Tumor-Related Genes in Gastric Carcinoma

The hypermethylation of the CpG islands is a common mechanism for the inactivation of tumor-related genes. In the present study, we analyzed the methylation status of genes for cell repair such as hMLH1, MGMT, and GSTP1, and a gastric cancer-specifically methylated DNA fragment, MINT 25 in gastric cancer cases and control groups. The study population consisted of 100 gastric cancer patients (50 distal and 50 proximal carcinomas), and 238 healthy controls. All genes showed more frequent hypermethylation in the cases than in the control group (p<0.0001). We investigated the association between promoter hypermethylation and relevant parameters including age, gender, alcohol consumption, smoking, and family history. There was a common hypermethylation of hMLH1 (p=0.008), MGMT (p= 0.0001), and GSTP1 (p=0.0003) in females. This study also demonstrates that hypermethylation was strongly associated with non-drinkers (MGMT, p=0.046 and MINT 25, p=0.049) and non-smokers (hMLH1, p=0.044; MGMT, p=0.0003; MINT 25, p=0.029). Moreover, the frequency of MINT 25 hypermethylation increased with age (p=0.037), and MGMT methylation was frequently detected in distal gastric cancer than in proximal type (p=0.038). Our study suggested that promoter hypermethylation of the genes involved in cell repair system and MINT 25 is associated strongly with some subgroups of primary gastric carcinoma.

Expression of Tumor Necrosis Factor-alpha, Interleukin-1beta and Inducible Nitric Oxide Synthase after Stereotaxic Injection of Lipopolysaccharide in Rat Hippocampus

BACKGROUND: Brain inducible nitric oxide synthase (iNOS) might be detectable in several pathologic conditions, and it is thought to play an important role in their pathophysiology. Tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta are believed to be essential factors of iNOS induction of the brain. METHODS: After intrahippocampal stereotaxic injection of lipopoly-saccharide (LPS), the rat brains were removed at 6, 12 and 24 h. The rat brain tissues were examined to clarify the expression patterns of TNF-alpha, IL-1beta and iNOS. RESULTS: The inflammatory cells which were stained with anti-TNF-alpha antibody, appeared in 6 h and increased for 24 h after LPS injection. The iNOS positive cells appeared after 12 h of LPS injection. A semiquantitative analysis of reverse transcription-polymerase chain reaction (RT-PCR) revealed that the TNF-alpha and IL-1beta mRNA arose at 1 h, peaked at 6 h and then declined until 48 h after LPS injection. The iNOS mRNA arose after 6 h, peaked at 12 h, and declined until 48 h after LPS injection. CONCLUSIONS: We conclude that the induction of inflammatory events by intrahippocampal injection of LPS activates TNF-alpha and IL-1beta secretion, and this is followed by an induction of iNOS expression. TNF-alpha and IL-1beta seem to be related with iNOS expression in brain inflammation.

Correlation Between Neuronal Apoptosis and Expression of Inducible Nitric Oxide Synthase after Transient Focal Cerebral Ischemia

BACKGROUND: Neuronal death in acute-phase cerebral ischemic injury is caused by necrosis. However, neuronal injury after reperfusion can be associated with apoptosis. METHODS: We used Sprague-Dawley rats whose brains were reperfused after middle cerebral artery occlusion for either 30 min or 2 h. We examined a relationship between apoptosis and the expression of inducible nitric oxide synthase (iNOS) in the brain tissue from 3 h to 14 days after reperfusion in both groups. RESULTS: TUNEL and iNOS positivity were closely related in both groups. The 2-h ischemia group exhibited increases in the amount of TUNEL and iNOS-positive cells for up to 3 days after reperfusion, at which the TUNEL and iNOS-positive cells decreased. The 30-min ischemia group exhibited peak positivity 24 h after reperfusion, followed by a similar decrease. iNOS mRNA expression peaked 3 h after reperfusion in the 30-min ischemia group, at which time it decreased. In the 2-h ischemia group, iNOS mRNA increased 3 h after reperfusion, peaked 24 h after reperfusion, and then decreased. CONCLUSION: These results indicated the occurrence of delayed apoptosis in transient cerebral ischemia. Increased expression of iNOS is closely associated with this apoptosis, and oxygen free radical-producing materials, such as nitric oxide, may play an important role in the induction of this apoptosis.