The effect of thrombosis-related laboratory values on mortality in COVID-19 infection

OBJECTIVE

COVID-19 may cause thrombosis in both venous and arterial systems. Familiarity with the signs and symptoms of thrombosis and its treatment is essential in treating COVID-19 infection and its complications. D-Dimer and mean platelet volume (MPV) are measurements related to the development of thrombosis. This study investigates whether MPV and D-Dimer values could be used to determine the risk of thrombosis and mortality in the COVID-19 early stages.

PATIENTS AND METHODS

424 patients who were COVID-19 positive, according to the World Health Organization (WHO) guidelines, were randomly and retrospectively included in the study. Demographic and clinical characteristics such as age, gender, and length of hospitalization were obtained from the digital records of participants. Participants were divided into living and deceased groups. The patients' biochemical, hormonal, and hematological parameters were analyzed retrospectively.

RESULTS

White blood cells (WBC), neutrophils, and monocytes were significantly different in the two groups (p-value <0.001), and their values were lower in the living group than in the deceased group. MPV median values did not differ according to prognosis (p-value = 0.994). While the median value was 9.9 in the survivors, it was 10 in the deceased. Creatinine, procalcitonin, ferritin, and the number of hospitalization days in living patients were significantly lower than in patients who died (p-value <0.001). Median values of D-dimer (mg/L) differ according to prognosis (p-value <0.001). While the median value was 0.63 in the survivors, it was found as 438 in the deceased.

CONCLUSIONS

Our results did not show any significant relationship between the mortality of COVID-19 patients and their MPV levels. However, a significant association between D-Dimer and mortality in COVID-19 patients was observed.

The significance of a novel inflammatory biomarker, presepsin, in predicting disease prognosis in patients with COVID-19

OBJECTIVE

This study aims at determining the significance of a novel inflammatory biomarker, presepsin, in predicting disease prognosis in patients with COVID-19.

PATIENTS AND METHODS

This retrospective study was concluded at the University Hospital between April and August 2020. The study involved 88 COVID-19 patients (48 men and 40 women). The patients were categorized into two groups: the patients admitted to the COVID-19 clinic, described as the moderate COVID-19 patients (Group-1; n=44), and those admitted to the internal medicine outpatient clinic, who were the mild COVID-19 patients (Group-2; n=44). The groups were compared using inflammatory markers: presepsin, C-Reactive Protein to Albumin Ratio, Neutrophil to Lymphocyte Ratio, and procalcitonin.

RESULTS

Serum presepsin levels (195.29 vs. 52.12 pg/ml) were significantly higher in the Group-1 compared to the Group-2 (p=0.001). The gender distribution and average age were similar in both groups (p > 0.05). While ferritin, lactate dehydrogenase, D-Dimer, platelet lymphocyte ratio, C-Reactive Protein to Albumin Ratio (p=0.001), erythrocyte sedimentation ratio, C-Reactive Protein and presepsin were significantly higher in the Group-1 compared to Group-2 (p<0.05), while hemoglobin and lymphocyte were significantly lower in the Group-1 than in Group-2 (p<0.05).

CONCLUSIONS

Serum presepsin levels were found to be significantly higher in moderate clinical group COVID-19 patients compared to mild group. Presepsin, a new inflammatory biomarker, may be useful in predicting the prognosis and early treatment of COVID-19 infection.

Predictors of disease severity, clinical course, and therapeutic outcome in COVID-19 patients: our experience with 1,700 patients

OBJECTIVE

Our study aimed at investigating the impacts of demographic, hematological, and biochemical factors on the clinical course and the prognostic outcome in adult COVID-19 patients.

PATIENTS AND METHODS

This retrospective study was performed in the internal medicine departments of two hospitals, and data were extracted from the medical files of 1,700 adult COVID-19 patients (836 females, 49.2%; 864 males, 50.8%) with an average age of 48.23 ± 16.68 (range: 18-93). Clinical data included baseline descriptives, prior medical history, admission date, treatment, and hematological and biochemical blood test results. The relationship between the survival, length of hospitalization, hematological, and biochemical parameters was investigated.

RESULTS

Advanced age (p<0.001), presence of at least on comorbid disease (p=0.045), increased length of hospitalization (p=0.006), elevated white blood cell (p=0.001) and neutrophil (p=0.002) counts, increased serum levels of glucose (p=0.027), blood urea nitrogen (p<0.001), AST (p=0.006), LDH (p<0.001), CRP (p>0.001), and D-dimer (p=0.001). In contrast, diminution of serum levels of albumin (p<0.001), ALT (p=0.028), calcium (p=0.022), and platelet count (p=0.010) were associated with increased mortality. There was a positive and weak relationship between serum D-dimer levels and length of hospitalization.

CONCLUSIONS

Our data imply that identifying and validating indicators that predict COVID-19 disease progression to improve health outcomes is crucial. Age, comorbidities, immunological response, radiographic abnormalities, laboratory markers, and signs of organ dysfunction may all predict poor outcomes individually or collectively. Identifying characteristics that predict COVID-19 problems is critical to guiding clinical management, improving patient outcomes, and allocating limited resources.

Quality evaluation of cell spheroids for transplantation by monitoring oxygen consumption using an on-chip electrochemical device

Three-dimensional cell spheroids are superior cell-administration form for cell-based therapy which generally exhibit superior functionality and long-term survival after transplantation. Here, we nondestructively measured the oxygen consumption rate of cell spheroids using an on-chip electrochemical device (OECD) and examined whether this rate can be used as a marker to estimate the quality of cell spheroids. Cell spheroids containing NanoLuc luciferase-expressing mouse mesenchymal stem cell line C3H10T1/2 (C3H10T1/2/Nluc) were prepared. Spheroids of high or low quality were prepared by altering the medium change frequency. After transplantation into mice, the high-quality C3H10T1/2/Nluc spheroids exhibited a higher survival rate than the low-quality ones. The oxygen consumption rate of the high-quality C3H10T1/2/Nluc spheroids was maintained at high levels, whereas that of the low-quality spheroids decreased with time. These results indicate that OECD-based measurement of the oxygen consumption rate can be used to estimate the quality of cell spheroids without destructive analysis of the spheroids.

Predictive value of systemic immune-inflammation index for cerebral reperfusion and clinical outcomes in patients with acute ischemic stroke undergoing endovascular treatment

OBJECTIVE

The systemic immune inflammation (SII) index has been an excellent prognostic indicator in patients with acute ischemic stroke (AIS). In this study, we assessed the utility of the SII in predicting the prognosis and reperfusion status of patients with AIS who underwent endovascular treatment (EVT).

PATIENTS AND METHODS

123 consecutive AIS patients were enrolled in our study. The receiver-operating characteristics (ROC) curve was used to determine the cut-off value of SII for predicting unsuccessful cerebral reperfusion. Multivariate logistic regression analysis analyzed the association between SII and unsuccessful reperfusion rate after EVT.

RESULTS

The median value of SII was significantly higher in patients with unsuccessful reperfusion compared to patients with successful reperfusion [2,029 (1,217-2,771) vs. 1,172 (680-2,145) respectively, p=0.003)]. A ROC curve analysis showed that the best cut-off value of SII for predicting unsuccessful reperfusion status was 1,690, with sensitivity and specificity of 71% and 69%, respectively. The area under the curve (AUC) was 0.673 (95% CI; 0.552-0.793). Multivariate analysis demonstrated that SII ≥ 1,690 value was an independent predictor of unsuccessful cerebral reperfusion and unfavorable clinical outcome after EVT (Hazard ratio - H.R.=3.713, 95% CI: 1.281-10.76, p=0.016, HR=2.28, 95% CI: 1.06-4.88, p=0.035, respectively).

CONCLUSIONS

We suggested that SII is a potential indicator to predict the unsuccessful cerebral reperfusion and unfavorable clinical outcome for patients with AIS undergoing EVT.

The novel biomarker, neopterin, can predict the severity of COVID-19

OBJECTIVE

SARS-CoV-2 infection primarily affects T-lymphocytes, particularly CD4+ and CD8+ T cells. However, there is a need for simpler and less expensive laboratory tests with predictive values comparable to CD4+ cell counts. Thus, the goal of this study was to investigate the role of neopterin levels in predicting intensive care and mortality in coronavirus disease patients in 2019.

PATIENTS AND METHODS

This retrospective study included 87 hospitalized patients who were diagnosed with COVID-19. Patients were divided into two groups: those receiving intensive care (Severe COVID-19; S-COVID-19) and those receiving non-intensive care (Moderate COVID-19; M-COVID-19). Patients' clinical characteristics, serum neopterin levels, and other laboratory data were compared across groups.

RESULTS

The average age was 63.9±155.2 years, and 44 (%) of the participants were male. WBC (p = 0.008), neutrophil (p = 0.002), HDL (p = 0.009), ferritin, calcium, albumin, LDH, APTT, lymphocyte, INR, D-dimer, troponin, prothrombin time sedimentation, and PaO2 (p = 0.001) were all associated with death. The neopterin level in the M-COVID-19 group was 3 (min-max; 3.1-5.9) and 3.2 (2.3-7) in the S-COVID-19 group, with no statistically significant difference (p = 0.456). Gender differences between groups were not significant (p = 0.183). According to the ROC analysis, if parameters such as age, D-Dimer, troponin, ferritin, albumin, LDH, CRP, procalcitonin, and PaO2 exceed the cut-off values and lymphocyte levels are below, it can predict the need for intensive care and mortality in COVID-19 patients.

CONCLUSIONS

Although we did not find statistically significant results with neopterin in terms of mortality in COVID-19 individuals in our study, more thorough, prospective, randomized controlled studies with expanded patient populations at various phases of the disease are needed.

The role of neutrophil albumin ratio in predicting the stage of non-small cell lung cancer

OBJECTIVE

Inflammation forms the basis of cancer development and progression. It causes changes in complete blood count parameters, such as neutrophil counts. Low albumin levels are associated with poor prognosis in cancer patients. We aimed to investigate the association between neutrophil to albumin ratio (NAR) and the stage of non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

257 NSCLC patients (24 females and 198 males) were included in the study. Patients were divided into two groups. Group 1 (n=61) included patients with early stage cancer (stage 1 and 2), while group 2  (n=196) included those with advanced stage cancer (stage 3 and 4). Demographic data, neutrophil, lymphocyte, platelet, white blood cell counts (WBC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), ferritin and albumin levels at the time of diagnosis were recorded. The NAR of 2 groups were compared.

RESULTS

There were no significant differences between the lymphocyte count (2.0 vs. 2.0 103/mm3) and platelet count (291 vs. 311 103/mm3) of the two groups (p > 0.05). ESR (38.8 vs. 57.5 mm/h), CRP (158 vs. 57 mg/l), ferritin (85 vs. 261 ng/ml), WBC count (8.6 vs. 10.6 103/mm3), neutrophil count (5.6 vs. 7.5 103/mm3), albumin values (2.9 vs. 3.7 gr/dl), and (p < 0.05) NAR levels (1.6 vs. 2.3) (p < 0.05) were significantly higher in group 2.

CONCLUSIONS

NAR can be used in predicting the stage of NSCLC.

Sensitive New Assay System for Serum Wisteria floribunda Agglutinin-Reactive Ceruloplasmin That Distinguishes Ovarian Clear Cell Carcinoma from Endometrioma

Wisteria floribunda agglutinin (WFA)-reactive ceruloplasmin (CP) is a candidate marker for ovarian clear cell carcinoma (CCC) reported in our previous paper. Herein, a new measurement system was developed to investigate its potential as a serum marker for CCC. Site-specific glycome analysis using liquid chromatography/mass spectrometry showed that WFA-CP from CCC binds to WFA via the GalNAcβ1,4GlcNAc (LDN) structure. We used mutant recombinant WFA (rWFA), which has a high specificity to the LDN structure, instead of native WFA, to increase the specificity of the serum sample measurement. To improve the sensitivity, we used a surface plasmon field-enhanced fluorescence spectroscopy immunoassay system, which is approximately 100 times more sensitive than the conventional sandwich enzyme-linked immunosorbent assay system. With these two improvements, the specificity and sensitivity of the serum rWFA-CP measurement were dramatically improved, clearly distinguishing CCC from endometrioma, from which CCC originates. This rWFA-CP assay can be used clinically for the serodiagnosis of early-stage CCC, which is difficult to detect with existing serum markers.

Sleep and Physical Performance: A Case Study of Collegiate Women's Division 1 Basketball Players

In this work, we present a case study to evaluate the connections between sleep, training load, and the perceptions of physical/emotional state of a collegiate, division 1 Women's basketball team. The study took place during the off- (3 weeks) and pre-season (6 weeks) while sleep was tracked using WHOOP wearable straps. Training load was recorded by the strength coach and athletes. Short Recovery and Short Stress (SRSS) questionnaire was used to evaluate the perceptions of athletes on their own emotional and physical states. Our results showed that heart rate measurements are associated with stress levels and recovery perception. We also discovered that the training load was not linked to the sleep variables without the considerations of athletic performance. However, training load may alter perceived stress and recovery which requires further exploration.

Highly sensitive biomolecular interaction detection method using optical bound/free separation with grating-coupled surface plasmon field-enhanced fluorescence spectroscopy (GC-SPFS)

Grating-coupled surface plasmon field-enhanced fluorescence spectroscopy (GC-SPFS) with optical bound/free (B/F) separation technique was developed by employing a highly directional fluorescence with polarization of surface plasmon-coupled emission (SPCE) to realize highly sensitive immunoassay regardless of the ligand affinity. A highly sensitive immunoassay system with GC-SPFS was constructed using a plastic sensor chip reproducibly fabricated in-house by nanoimprinting and applied to the quantitative detection of an anti-lysozyme single-domain antibody (sdAb), to compare conventional washing B/F separation with optical B/F separation. Differences in the affinity of the anti-lysozyme sdAb, induced by artificial mutation of only one amino acid residue in the variable domain were attributed to higher sensitivity than that of the conventional Biacore surface plasmon resonance (SPR) system. The detection limit (LOD; means of six replicates of the zero standard plus three standard deviations) of the GC-SPFS immunoassay with optical B/F separation, was estimated to be 1.2 ng/ml with the low-affinity ligand (mutant sdAb Y52A: K_D level was of the order of 10⁻⁷ ~ 10⁻⁶ M) and was clearly improved as compared to that (LOD: 9.4 ng/ml) obtained with the conventional washing B/F separation. These results indicate that GC-SPFS with the optical B/F separation technique offers opportunities to re-evaluate low-affinity biomaterials that are neither fully utilized nor widespread, and could facilitate the creation of novel and innovative methods in drug and diagnostic development.

Clinical significance of the LacdiNAc-glycosylated prostate-specific antigen assay for prostate cancer detection

To reduce unnecessary prostate biopsies (Pbx), better discrimination is needed. To identify clinically significant prostate cancer (CSPC) we determined the performance of LacdiNAc‐glycosylated prostate‐specific antigen (LDN‐PSA) and LDN‐PSA normalized by prostate volume (LDN‐PSAD). We retrospectively measured LDN‐PSA, total PSA (tPSA), and free PSA/tPSA (F/T PSA) values in 718 men who underwent a Pbx in 3 academic urology clinics in Japan and Canada (Pbx cohort) and in 174 PC patients who subsequently underwent radical prostatectomy in Australia (preop‐PSA cohort). The assays were evaluated using the area under the receiver operating characteristics curve (AUC) and decision curve analyses to discriminate CSPC. In the Pbx cohort, LDN‐PSAD (AUC 0.860) provided significantly better clinical performance for discriminating CSPC compared with LDN‐PSA (AUC 0.827, P = 0.0024), PSAD (AUC 0.809, P < 0.0001), tPSA (AUC 0.712, P < 0.0001), and F/T PSA (AUC 0.661, P < 0.0001). The decision curve analysis showed that using a risk threshold of 20% and adding LDN‐PSA and LDN‐PSAD to the base model (age, digital rectal examination status, tPSA, and F/T PSA) permitted avoidance of even more biopsies without missing CSPC (9.89% and 18.11%, respectively vs 2.23% [base model]). In the preop‐PSA cohort, LDN‐PSA values positively correlated with tumor volume and tPSA and were significantly higher in pT3, pathological Gleason score ≥ 7. Limitations include limited sample size, retrospective nature, and no family history information prior to biopsy. LacdiNAc‐glycosylated PSA is significantly better than the conventional PSA test in identifying patients with CSPC. This study was approved by the ethics committee of each institution (“The Study about Carbohydrate Structure Change in Urological Disease”; approval no. 2014‐195).

Wisteria floribunda Agglutinin and Its Reactive-Glycan-Carrying Prostate-Specific Antigen as a Novel Diagnostic and Prognostic Marker of Prostate Cancer

Wisteria floribunda agglutinin (WFA) preferably binds to LacdiNAc glycans, and its reactivity is associated with tumor progression. The aim of this study to examine whether the serum LacdiNAc carrying prostate-specific antigen–glycosylation isomer (PSA-Gi) and WFA-reactivity of tumor tissue can be applied as a diagnostic and prognostic marker of prostate cancer (PCa). Between 2007 and 2016, serum PSA-Gi levels before prostate biopsy (Pbx) were measured in 184 biopsy-proven benign prostatic hyperplasia patients and 244 PCa patients using an automated lectin-antibody immunoassay. WFA-reactivity on tumor was analyzed in 260 radical prostatectomy (RP) patients. Diagnostic and prognostic performance of serum PSA-Gi was evaluated using area under the receiver-operator characteristic curve (AUC). Prognostic performance of WFA-reactivity on tumor was evaluated via Cox proportional hazards regression analysis and nomogram. The AUC of serum PSA-Gi detecting PCa and predicting Pbx Grade Group (GG) 3 and GG ≥ 3 after RP was much higher than those of conventional PSA. Multivariate analysis showed that WFA-reactivity on prostate tumor was an independent risk factor of PSA recurrence. The nomogram was a strong model for predicting PSA-free survival provability with a c-index ≥0.7. Serum PSA-Gi levels and WFA-reactivity on prostate tumor may be a novel diagnostic and pre- and post-operative prognostic biomarkers of PCa, respectively.

EFFECTS OF VITAMIN D ANALOGS ON ERYTHROPOIESIS-STIMULATING AGENT DASAGE AND SECONDARY ANEMIA IN HEMODIALYSIS PATIENTS

To investigate the effects of Vitamin D Analogs, paricalcitol and alphacalcidol, on hemoglobin levels and erythropoietin-stimulating agents' dosage in hemodialysis patients with chronic renal failure. A total of 310 patients under hemodialysis treatment for chronic renal failure were included in this retrospective multicenter study. Data on serum parathormone and hemoglobin levels, erythropoietin-stimulating agents' doses, C-reactive protein, calcium and phosphate levels were collected from medical records to comparatively evaluate paricalcitol, alphacalcidol and no treatment groups. Apart from significantly higher levels for hematocrit in patients treated with paricalcitol compared to pre-treatment values (32.3(3.8) vs. 34.1(3.1) p=0.007), pre-treatment and post-treatment values for biochemical parameters were similar in paricalcitol and alphacalcidol groups including ESA dose. A significant increase in parathormone levels (p=0.000 for each) while a significant decrease in calcium (p=0.003 and 0.040, respectively), Hb (p=0.001 and 0.009, respectively) and hematocrit (p=0.001 and 0.021, respectively) levels were determined in paricalcitol and alphacalcidol treated patients compared with untreated patients. Also, phosphate levels in alphacalcidol treated patients were significantly higher (p=0.018) than untreated patients. Our findings revealed insufficient suppression of parathormone levels and there of lower hemoglobin and hematocrit levels, but similar ESA dosage among CRF patients treated with Vitamin D analogs compared with untreated patients.

Sensitive detection of a tumor marker, α-fetoprotein, with a sandwich assay on a plasmonic chip

Two types of plasmonic silver- and gold-coated grating biosensor chips (plasmonic chip) were applied in the detection of α-fetoprotein (AFP) with a sandwich imunoassay and surface plasmon field-enhanced fluorescence. On the plasmonic chip, unlabeled marker in the sandwich immunoassay was first quantitatively detected over a wide range between 10(-12) and 10(-8) g/mL. The affinity constants between AFP and anti-AFP antibody, which were obtained by fitting the experimental data to the Langmuir isotherm adsorption curve, were 1 × 10(8) g(-1) mL regardless of the kind of metal in the plasmonic chips. Although the fluorescence intensity on the silver plasmonic chip was 5 times larger than that on the gold plasmonic chip, the limit of detection (LOD) was on the order of 10(-11) g/mL and not improved with a silver plasmonic chip. Herein, we used a new setup that generated less dispersions of both the fluorescence intensity for nonspecific adsorption and the background (optical blank) signal and improved the LOD of AFP to 4 pg/mL (55 fM) with the silver plasmonic chip. With the highly sensitive detection in the sandwich immunoassay, the development of a plasmonic chip for clinical diagnosis by a blood test is promising.

High-sensitivity immunoassay with surface plasmon field-enhanced fluorescence spectroscopy using a plastic sensor chip: application to quantitative analysis of total prostate-specific antigen and GalNAcβ1-4GlcNAc-linked prostate-specific antigen for prostate cancer diagnosis

A high-sensitivity immunoassay system with surface plasmon field-enhanced fluorescence spectrometry (SPFS) was constructed using a plastic sensor chip and then applied to the detection of total prostate-specific antigen (total PSA) and GalNAcβ1-4GlcNAc-linked prostate-specific antigen (LacdiNAc-PSA) in serum, to discriminate between prostate cancer (PC) and benign prostate hyperplasia (BPH). By using this automated SPFS immunoassay, the detection limit for total PSA in serum was as low as 0.04 pg/mL, and the dynamic range was estimated to be at least five digits. A two-step sandwich SPFS immunoassay for LacdiNAc-PSA was constructed using both the anti-PSA IgG antibody to capture PSA and Wisteria floribunda agglutinin (WFA) for the detection of LacdiNAc. The results of the LacdiNAc-PSA immunoassay with SPFS showed that the assay had a sensitivity of 20.0 pg/mL and permitted the specific distinction between PC and BPH within the PSA gray zone. These results suggested that high-sensitivity automated SPFS immunoassay systems might become a powerful tool for the diagnosis of PC and other diseases.

Kinetically Selective Inhibitors of Histone Deacetylase 2 (HDAC2) as Cognition Enhancers

Kinetically selective inhibitors of HDAC2 enhanced learning and memory in a CK-p25 mouse model of neurodegeneration.

Aiming towards the development of novel nootropic therapeutics to address the cognitive impairment common to a range of brain disorders, we set out to develop highly selective small molecule inhibitors of HDAC2, a chromatin modifying histone deacetylase implicated in memory formation and synaptic plasticity. Novel ortho-aminoanilide inhibitors were designed and evaluated for their ability to selectively inhibit HDAC2 versus the other Class I HDACs. Kinetic and thermodynamic binding properties were essential elements of our design strategy and two novel classes of ortho-aminoanilides, that exhibit kinetic selectivity (biased residence time) for HDAC2 versus the highly homologous isoform HDAC1, were identified. These kinetically selective HDAC2 inhibitors (BRD6688 and BRD4884) increased H4K12 and H3K9 histone acetylation in primary mouse neuronal cell culture assays, in the hippocampus of CK-p25 mice, a model of neurodegenerative disease, and rescued the associated memory deficits of these mice in a cognition behavioural model. These studies demonstrate for the first time that selective pharmacological inhibition of HDAC2 is feasible and that inhibition of the catalytic activity of this enzyme may serve as a therapeutic approach towards enhancing the learning and memory processes that are affected in many neurological and psychiatric disorders.

The effects of L type calcium channels on the electroencephalogram recordings in WAG/RIJ rat model of absence epilepsy

BACKGROUND

Epilepsy is one of the most important central nervous system disorder and 1% of the total world population suffers from this disorder which require a chronic drug treatment. Most of the researchers suggested that excessive calcium entry into neurons is the main triggering event in the initiation of epileptic discharges but the role of L type calcium channels has not been clarified in absence epilepsy.

AIM

In this study, it is aimed to investigate the antiepileptic effects of nifedipine, an L type calcium channel blocker and BAY K8644, an L type calcium channel opener in a genetic model of absence epilepsy in WAG/Rij rats.

MATERIALS AND METHODS

Thirty two WAG/Rij rats were allocated into four groups; sham (only saline injected), only nifedipine (an L type calcium channel blocker) injected group (40 µg/2 µl; 60 µg/2 µl; 80 µg/2 µl), only BAY K8644 (1,4 Dihydro-2,6-dimethyl-5-nitro-4-trifluoromethyl- phenyl-3-pyridine carboxylic acid methyl ester) (L-type Ca2+-channel activator) injected group (40 µg/2 µl; 60 µg/2 µl; 80 µg/2 µl) and combination of their most effective doses BAY K8644 (60 µg/2 µl) after nifedipine (60 µg/2 µl) injected group. All agents were given by intracerebroventricular injection. The beta, alpha, theta and delta wave ratios of electroencephalogram recordings and the frequency and duration of SWDs (spike and wave discharges) were analyzed and compared between four groups.

RESULTS

Nifedipine increased the number and duration of spike wave discharges whereas BAY K8644 decreased both of them. When BAY K8644 was given after nifedipine, there was no significant difference with control group.

CONCLUSIONS

L type calcium channels play an activator role on spike wave discharges and have positive effects on the duration and frequency.

The presence of Helicobacter pylori in cervical preinvasive lesions

PURPOSE

Helicobacter pylori (H. pylori) is believed to play a role in several gynecological and obstetric pathologies since the cervical mucosa resembles the gastric environment. The microorganism is expected to infect the upper genital tract via the oral-genital and fecal-genital routes.

METHODS

We studied 35 cases with benign, ASCUS, ASC-H, LSIL and HSIL pap-smear results. The presence of H. pylori in the uterine cervix and active infection were investigated with the H. pylori stool antigen test. Biopsy specimens were stained with hematoxylin-eosin and Warthin-Starry stains to find H. pylori in cervical tissue. Seroprevalence was investigated by using ELISA for H. pylori IgG and IgA.

RESULTS

The H. pylori seroprevalence was 65.7%; further, 17.1% of the cases had an active infection. H. pylori was not found in the cervix or the cervicovaginal secretions.

CONCLUSION

The cervix is not a reservoir for H. pylori, and the microorganism does not appear to be transmitted through the fecal-genital route.

Characteristics and medical management of patients with rheumatoid arthritis and ankylosing spondylitis

Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) are chronic, progressive, systemic inflammatory rheumatic diseases that lead to serious disability. The objective of this study was to investigate the demographic and clinical characteristics of the patients with RA and AS who were treated in tertiary hospitals in Turkey and to analyze their current medical management. A total of 562 RA and 216 AS patients were evaluated. The mean age of RA patients was 52.1 +/- 12.6 years. The female to male ratio was 3.7:1. Of the RA patients, 72.2% had positive rheumatoid factor (RF), 62.9% had high C-reactive protein, and 75.2% had radiological erosion. The ratio of patients with Disease Activity Score (DAS) 28 >3.2 was 73.9% and of those with Health Assessment Questionnaire (HAQ) > or =1.5 was 20.9%. There was a statistically significant increase in RF positivity and HAQ scores in the group with higher DAS 28 score. Frequency of extraarticular manifestations was 22.4%. The ratio of the patients receiving disease modifying antirheumatic drugs (DMARD) was 93.1%, and 6.9% of the patients were using anti-tumor necrosis factor (TNF) blocking agents. In AS, the mean age of the patients was 38.1 +/- 10.6, and the female to male ratio was 1:2.5. The time elapsed between the first symptom and diagnosis was 4.3 years. The ratio of peripheral joint involvement was 29.4%. Major histocompatibility complex, class I, B 27 was investigated in 31.1% of patients and the rate of positivity was 91%. In 52.4% of the patients, Bath AS Disease Activity Index (BASDAI) was > or =4. The erythrocyte sedimentation rate, Bath AS Functional Index, and peripheral involvement were significantly higher in the group with BASDAI > or =4. Frequency of extraarticular involvement was 21.2% in AS patients. In the treatment schedule, 77.5% of AS patients were receiving sulphasalazine, 15% methotrexate, and 9.9% anti-TNF agents. Despite widespread use of DMARD, we observed high disease activity in more than half of the RA and AS patients. These results may be due to relatively insufficient usage of anti-TNF agents in our patients and therefore these results mostly reflect the traditional treatments. In conclusion, analysis of disease characteristics will inform us about the disease severity and activity in RA and AS patients and could help in selecting candidate patients for biological treatments.

Effect of hypothyroidism on the purinergic responses of corpus cavernosal smooth muscle in rabbits

AIMS

Several studies have reported evidence of hormonal abnormalities in 25-35% of impotent men. Hypothyroidism has been reported to occur in 6% of impotent men. In the present study, we examined purinergic relaxation responses in hypothyroidism in an experimental rabbit model and compared them with controls to evaluate the possible involvement of the purinergic pathway.

MATERIALS AND METHODS

The study comprised 20 male New Zealand white rabbits. The rabbits were divided into two equal groups. We tested the effects of ATP, alpha beta ATP, and adenosine precontracted with phenylephrine on the isolated corpus cavernosum preparations from control and hypothyroid rabbits. We also evaluated the effects of ATP, alpha beta ATP, and adenosine on the cGMP levels in the isolated corpus cavernosum preparations from control and hypothyroid rabbits.

RESULTS

T3, T4, and testosterone levels were significantly lower in hypothyroid rabbits. ATP, alpha beta ATP, carbachol, and electrical field stimulation (EFS)-induced frequency-dependent relaxation responses in the isolated rabbit corpus cavernosum strips precontracted with phenylephrine reduced significantly (P<0.05). Adenosine-induced relaxation responses did not change significantly in hypothyroid rabbits.

CONCLUSION

Reduction of relaxation response in hypothyroid rabbits corpus cavernosum can depend on a decreased release of nitric oxide (NO) from nitrergic nerves and endothelium.

Investigation of the relaxant effects of propofol on ovalbumin-induced asthma in guinea pigs

BACKGROUND AND OBJECTIVE

Because the incidence of asthma appears to be increasing, the importance of proper perioperative management of individuals with asthma will also continue to increase. Although its mechanism of smooth muscle relaxation is unknown, propofol has been associated with less bronchoconstriction during anaesthetic induction. The aim of this study was to investigate the possible mechanism of these effects and the effects of propofol on the isolated trachea preparations from control and ovalbumin-sensitized guinea pigs.

METHODS

Adult male guinea pigs, weighing 280-330 g, were randomly allocated to two experimental groups, each consisting of 10 animals. Ten guinea pigs were sensitized by intramuscular injections of 0.30 mL of a 5% (w/v) ovalbumin/saline solution into each thigh (0.6 mL total) on days 1 and 4, whereas the remaining 10 served as controls receiving a total of 0.6 mL distilled water on days 1 and 4 as placebo. The isolated trachea preparations were mounted in tissue baths with modified Krebs-Henseleit solution and aerated with 95% oxygen and 5% carbon dioxide. We tested the effects of propofol (10(-7)-10(-3) M) on resting tension and after precontraction with carbachol and histamine on isolated trachea preparations from control and ovalbumin-sensitized guinea pigs. We also tested the effect of propofol on isolated trachea preparations precontracted with carbachol and histamine in the absence and presence of different inhibitors or antagonists. We investigated propofol responses in tracheal smooth muscle precontracted with CaCl2.

RESULTS

Propofol (10(-7)-10(-3) M) produced a concentration-dependent relaxation of isolated tracheal preparations precontracted by carbachol (10(-6) M) and histamine (10(-6) M) in both groups. Preincubation with N(w)-nitro L-arginine methyl ester (3x10(-5) M), indomethacin (10(-5) M) or propranolol (10(-4) M) did not produce a significant alteration on propofol-induced relaxation responses (P>0.05), while preincubation with tetraethylammonium (3x10(-4) M) significantly decreased the propofol-induced relaxation responses in both groups (P<0.05). Propofol (10(-7)-10(-3) M) induced concentration-dependently relaxations in isolated trachea rings precontracted with CaCl2 in both the control and ovalbumin-sensitized groups.

CONCLUSION

Propofol induced concentration-dependent relaxations in precontracted, isolated trachea smooth muscle of guinea pigs in both the control and ovalbumin-sensitized groups. These relaxations were independent of epithelial function and stimulation of beta adrenergic receptors. Opened Ca2+-sensitive K+ channels and inhibited L-type Ca2+ channels can contribute to these relaxations.

Characterization of cap-shaped silver particles for surface-enhanced fluorescence effects

Surface-enhanced fluorescence has potentially many desirable properties as an analytical method for medical diagnostics, but the effect observed so far is rather modest and only in conjunction with fluorophores with low quantum yields. Coupled with the fact that preparation of suitable surfaces at low costs has been difficult, this has limited its utilities. Here we report a novel method for forming uniform and reproducible surfaces with respectable enhancement ratios even for high-quantum-yield fluorophores. Formation of dense surface-adsorbed latex spheres on a flat surface via partial aggregation, followed by evaporation of silver, results in a film consisting of cap-shaped silver particles at high densities. Binding of fluorescence biomolecules, either through physisorption or antigen-antibody reaction, was performed, and enhancements close to 50 have been observed with fluorophores such as R-phycoerythrin and Alexa 546-labeled, bovine serum albumin, both of which have quantum yields around 0.8. We attribute this to the unique shape of the silver particle and the presence of abundant gaps among adjacent particles at high densities. The effectiveness of the new surface is also demonstrated with IL-6 sandwich assays.

The incidence and management of acute and chronic rejection after living donor liver transplantation

Living donor liver transplantation (LDLT) is a good alternative to cadaveric liver transplantation for end-stage liver disease. Herein we report the outcome of 132 LDLTs performed between 1999 and 2005, with special emphasis on the incidence and management of acute and chronic rejection. Among the LDLT population a first acute rejection episode (ARE) was clinically suspected in 24% and proven by liver biopsy in 11%. According to the Banff classification, 50% of AREs were grade 1, and 50%, grade 2. There was no grade 3 AREs. The first ARE occurred between 7 days and 23 months posttransplantation (mean 97 days, median 70 days). Ninety-seven percent (31/32) of the AREs occurred within the first year after transplantation and 3% (1/32) in the second year. Among the patients with ARE, 23% developed a second ARE between 4 and 11 months. A third ARE was detected in 8% of patients after month 18. All AREs responded to adjustment of immunosuppressive doses or steroid boluses. Chronic rejection (CR) was detected in 2%. In conclusion, the incidences of ARE and CR are consistent with the previously reported data. Acute and chronic rejections seem to be mild and easily manageable clinical conditions. Our results also showed a significant difference between clinically suspected and biopsy-proven ARE emphasizing the importance of indicated liver biopsies in the management of the LDLT population.

Vasorelaxant effect of opioid analgesics on the isolated human radial artery

BACKGROUND AND OBJECTIVE

Arterial grafts are prone to vasospasm. Opioid analgesics are commonly used in the perioperative course of cardiac surgical procedures. Therefore, we investigated the direct effects of morphine, meperidine, fentanyl and remifentanil on the human radial artery.

METHODS

Radial artery segments, obtained from 20 patients, were precontracted with phenylephrine. Using the organ bath technique, the endothelium-independent vasodilatation was tested in vitro by addition of cumulative concentrations of morphine, meperidine, fentanyl and remifentanil in separate organ baths, in the presence or absence of naloxone. Indomethacin and NG-nitro-L-arginine methyl ester was added to all organ bath in order to determine the effects of prostaglandins and nitric oxide, respectively.

RESULTS

Morphine (10(-8) - 10(-4) mol L-1), meperidine (10(-10) - 10(-6) mol L-1), fentanyl (10(-10) - 10(-6) mol L-1) and remifentanil (10(-8) - 10(-4) mol L-1) caused a concentration-dependent vasorelaxation in the human being artery rings. The relaxations in the presence of naloxane did not change. The maximal relaxant effects of meperidine and fentanyl were significantly greater than those of morphine and remifentanil (P < 0.05).

CONCLUSIONS

These findings indicate that morphine, meperidine, fentanyl and remifentanil produce concentration-dependent and endothelium-independent relaxations in human being radial artery rings. Meperidine and fentanyl are more potent relaxant agents than morphine and remifentanil in the human being radial artery in vitro.

Electrochemical mutagen screening using microbial chip

Electrochemical microbial chip for mutagen screening were microfabricated and characterized by scanning electrochemical microscopy (SECM). Salmonella typhimurium TA1535 with a plasmid pSK1002 carrying a umuC'-'lacZ fusion gene was used for the whole cell mutagen sensor. The TA1535/pSK1002 cells were exposed to mutagen solutions containing 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamido (AF-2), mitomycin C (MMC) or 2-aminoanthracene (2-AA) and embedded in a microcavity (5nl) on a glass substrate using collagen gel. The beta-galactosidase expression on the microbial chip was electrochemically monitored using p-aminophenyl-beta-d-galactopyranoside (PAPG) as the enzymatic substrate. This system has several advantages compared with the conventional umu test: drastic reduction of the sample volume, less time-consuming for beta-galactosidase detection (free from substrate reaction time) and lower detection limit for the three mutagens (AF-2, MMC, 2-AA). Finally, a multi-sample assay was carried out using the microbial array chip with four microcavities.

Amperometric detection of the bacterial metabolic regulation with a microbial array chip

A microbial array chip with collagen gel spots entrapping living bacterial cells has been applied to investigate the metabolic regulation in Paracoccus denitrificans. Scanning electrochemical microscopy (SECM) was used to monitor the ferrocyanide production that reflects the electron flow in the respiratory chain located within the internal membrane of P. denitrificans. The ferrocyanide production from P. denitrificans largely depends on the types of the carbon source (glucose or lactate), suggesting that the electron flow rate in the respiratory chain depends on the activity of the metabolic pathway located up-stream of the respiratory chain. More importantly, it was found that the enzymes affecting glucose catabolic reactions were significantly up-regulated in cultures with a nutrient agar medium containing D-(+)-glucose as a sole carbon source. Enzyme assays using crude extracts of P. denitrificans were carried out to identify the enzymes expressed at a higher level in cultures supplemented with D-(+)-glucose. It was confirmed that the pyruvate kinase and enzymes of the overall Entner-Doudoroff pathway were highly induced in cultures containing D-(+)-glucose.

Interactive effect of sevoflurane with isradipine or indomethacin on spontaneous contractile activity of isolated pregnant rat myometrium

Volatile anesthetics, calcium antagonists and non-steroidal anti-inflammatory drugs inhibit contractile activity of myometrial smooth muscle. The aim of this study was to investigate the interactive effect of sevoflurane with isradipine or indomethacin on spontaneous contractile activity of myometrial strips isolated from pregnant rats. The myometrial strips were excised from rats (250-300 g) at 19-21 days of gestation and mounted in tissue baths for recording of isometric tension. Sevoflurane (0.5 to 3 MAC) inhibited the amplitude and frequency of spontaneous myometrial contractions in a concentration-dependent manner (P<0.05). Sevoflurane responses were repeated in the presence of isradipine (a dihydropyridine-type calcium channel blocker) and indomethacin (a non-selective cyclooxygenase (COX) inhibitor). Pretreatment with isradipine (10(-6) M) or indomethacin (10(-7) M), concentrations that themselves had no effect on spontaneous contractility, significantly increased the inhibitor responses to sevoflurane on amplitude and frequency of myometrial contractions, beginning at 1 MAC (P<0.05). Blockade of calcium channels in myometrial smooth muscle may increase the inhibitor effect of sevoflurane. Further work is needed to determine the cellular mechanism(s) of this interaction.

Respiration activity of Escherichia coli entrapped in a cone-shaped microwell and cylindrical micropore monitored by scanning electrochemical microscopy (SECM)

The metabolic activity of E. coli cells embedded in collagen gel microstructures in a cone-shaped well and in a cylindrical micropore was investigated using scanning electrochemical microscopy (SECM), based on the oxygen consumption rate and the conversion rate from ferrocyanide to ferricyanide. The analysis of the concentration profiles for oxygen and ferrocyanide afforded the oxygen consumption rate and the ferrocyanide production rate. A comparison indicated that the ferrocyanide production rates were larger than the oxygen consumption rate, and also that the rates observed in the cylindrical micropore were larger than those observed in the cone-shaped well. The ferrocyanide production rate of a single E. coli cell was calculated to be (5.4 +/- 2.6) x 10(-19) mol s(-1), using a cylindrical micropore system.

On-chip electrochemical measurement of β-galactosidase expression using a microbial chip

[small beta]-Galactosidase expression in a small number of Escherichia coli cells has been measured in real time with an electrochemical sensor chip. E. coli cells were embedded using collagen gel within a micropore which was microfabricated onto a chip. The activity of the expressed [small beta]-galactosidase was determined using p-aminophenyl [small beta]-d-galactopyranoside (PAPG) as a substrate.

Fabrication of microbial chip using collagen gel microstructure

A microbial chip was fabricated by filling the micropores on a glass substrate with collagen-embedded Escherichia coli(E. coli) cells, and characterized by scanning electrochemical microscopy (SECM) in a solution containing ferricyanide. The activity of the E. coli cells in the collagen gel microstructure was imaged and characterized with SECM by mapping the localized concentration of ferrocyanide produced by the respiration of the cells. The SECM-based activity measurement detected as low as approximately 100 E. coli cells. Furthermore, the optical-microscopic observation indicated that the E. coli cells on the chip proliferated during the incubation. The sequential SECM measurements were performed for the same E. coli chip to obtain the microbial growth curve for a small number of microorganisms.

Monitoring the cellular activity of a cultured single cell by scanning electrochemical microscopy (SECM). A comparison with fluorescence viability monitoring

The respiratory activities of cultured HeLa cells were monitored at a single cell level using scanning electrochemical microscopy (SECM) that produces images of the localized distribution of oxygen around the cell. The change in the cellular activity was traced after exposures to KCN, ethyl alcohol and the antibiotic drug, Antimycin A. The results were compared with those from the conventional fluorescence monitoring using Calcein-AM that is sensitive to deformation of the cell membrane. The SECM-based measurement follows the decrease in the cellular activity upon exposure to KCN and Antimycin A more rapidly than the fluorescence-based measurements, demonstrating that SECM is suitable for studying the cellular influence of respiration inhibitors.

Differentiation of adrenal adenomas (lipid rich and lipid poor) from nonadenomas by use of washout characteristics on delayed enhanced CT

BACKGROUND

We describe nonenhanced, early contrast-enhanced, and delayed contrast-enhanced computed tomographic (CT) features and contrast washout characteristics of lipid-poor and lipid-rich adrenal adenomas and nonadenomas to determine the role of these methods in distinguishing one type from the other.

METHODS

Sixty-five patients with 77 adrenal masses (16 lipid-poor and 37 lipid-rich adenomas and 24 nonadenomas) were consecutively examined with dynamic helical CT. Nonenhanced CT was followed by early enhanced CT at 5, 10, 15, and 30 min delays after administration of contrast material.

RESULTS

The difference between the mean nonenhanced and early contrast-enhanced values of the lipid-poor adenomas and nonadenomas was statistically significant, but the ranges of the values were overlapping. The lipid-poor adenomas had lower mean attenuation values than those of nonadenomas on delayed contrast-enhanced scans at each delay time, but these differences did not reach statistical significance. Even though the relative percentage washout of the lipid-poor adenomas was lower than that of lipid-rich adenomas, it was remarkably different from that of the nonadenomas.

CONCLUSIONS

The absolute or relative percentage washout of contrast material on delayed contrast-enhanced CT is a highly specific test for the differentiation of lipid-poor and lipid-rich adrenal adenomas from adrenal nonadenomas.

Scanning electrochemical microscopy-based drug sensitivity test for a cell culture integrated in silicon microstructures

The respiratory activity of collagen-embedded living cells was imaged by scanning electrochemical microscopy (SECM) with the objective to study anticancer drug sensitivity. Two kinds of cancer cells, the human erythroleukemia cell line (K562) and its adriamycin-resistant subline (K562/ADM), were immobilized at the array of microholes micromachined on a silicon wafer for comparative characterization of their sensitivity to the anticancer drug, ADM. The results obtained by the SECM method showed correspondence to a conventional colorimetric assay (SDI assay). Furthermore, since the SECM assay is based on the noninvasive measurement of the respiration activity, continuous monitoring of a dose response was possible.

Computed tomography findings of primary serous papillary carcinoma of the peritoneum in women

With the aim to describe preoperative computed tomography (CT) findings, the clinical, histopathological, and CT findings of the 12 consecutive patients with a confirmed diagnosis of primary peritoneal serous papillary carcinoma (PPSPC) were retrospectively evaluated. Of the 12 patients with a mean age of 57.5 +/- 10.3 years, ten (83.3%) were postmenopausal. Serum Ca-125 levels were elevated in all patients. Ten (83.3%) had Stage III and two (16.7%) patients had Stage IV disease and none of the excised ovaries had deep parenchymal involvement. The most common CT findings were the omental (n = 11), mesenterial (n = 11) and parietal peritoneal involvements (n = 10), and variable amount of ascites (n = 10). Pelvic peritoneal involvement in four (33.3%) patients was so extensive that it resembled a mass in the Douglas pouch. Thickening of the wall of gastrointestinal viscera (n = 9), lymphadenopathy (n = 5) and pleural effusion (n = 5) were the other CT findings and calcification was seen in only three (25.0%) patients. Although, none of them was characteristic, CT features of diffuse peritoneal, omental and mesenterial involvement especially in middle-aged or elderly postmenopausal women with normal-size ovaries in the absence of an identifiable primary site in conjunction with elevated level of serum CA-125 should suggest the possibility of PPSPC.

A microbial chip combined with scanning electrochemical microscopy

A microbial chip for bioassay was fabricated and its performance was characterized by scanning electrochemical microscopy (SECM). The microbial chip was prepared by spotting a suspension of Escherichia coli on a polystyrene substrate by using a glass capillary pen. The respiration activity of the E. coli spot was imaged with SECM by mapping the oxygen concentration around the spot. The SECM images of the microbial chips clearly showed spots with lower reduction currents, indicating that E. coli in the spots uptake oxygen by respiration. The bactericidal effects of antibiotics (streptomycin and ampicillin) were measured using the E. coli-based microbial chip, and discussed in comparison with the minimum inhibitory concentration (MIC) determined by an agar plate dilution method.

Prevention of postoperative adhesion formation in rat uterine horn model by nimesulide: a selective COX-2 inhibitor

BACKGROUND

Pelvic surgery is one of the main causes of intraperitoneal (i.p.) adhesions that create various medical problems including pelvic pain, bowel obstructions and female infertility. A rat model was used to investigate the efficacy of nimesulide, a selective cyclooxygenase-2 inhibitor, in the prevention of adhesion formation.

METHODS

Fifty Wistar-Albino rats underwent bilateral uterine horn injury with a unipolar cautery. Study groups were as follows: (i) control group, no adjuvant therapy; (ii) i.p. Ringer's lactate group, 2 ml Ringer's lactate solution was instilled i.p.; (iii) i.p. Ringer's lactate plus nimesulide group, 1 ml Ringer's lactate plus 1 ml nimesulide (0.5 mg/ml) were given i.p.; (iv) intramuscular (i.m.) nimesulide group, 1 ml i.m. nimesulide (0.5 mg/ml) was given preoperatively for 5 days; and (v) i.p. nimesulide group, 1 ml nimesulide (0.5 mg/ml) was instilled i.p. At the end of the study all animals were killed, and a standard adhesion scoring system was applied by a blinded examiner.

RESULTS

The mean adhesion extent in study groups was as follows: 1.33 +/- 0.76 in control group, 1.40 +/- 0.90 in i.p. Ringer's lactate group, 0.75 +/- 0.70 in i.p. Ringer's lactate plus nimesulide group, 0.25 +/- 0.44 in i.m. nimesulide group and 0.31 +/- 0.70 in i.p. nimesulide group. The mean +/- SD adhesion severities of control, i.p. Ringer's lactate, i.p. Ringer's lactate plus nimesulide, i.m. nimesulide, and i.p. nimesulide groups were 0.58 +/- 0.35, 0.30 +/- 0.41, 0.27 +/- 0.3, 0.12 +/- 0.28 and 0.15 +/- 0.35 respectively. The lowest adhesions were found in the groups treated with nimesulide i.m. and nimesulide i.p. ( P < 0.05).

CONCLUSIONS

This study showed that preoperative i.m. or postoperative i.p. administration of nimesulide to the site of injury reduced the formation of postoperative adhesions in a rat uterine horn model.

Chloride channel blockers 5-nitro-2-(3-phenylpropylamino) benzoic acid and anthracene-9-carboxylic acid inhibit contractions of pregnant rat myometrium in vitro

OBJECTIVE

We compared in vitro relaxant effect of chloride channel modulators, such as 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) and anthracene-9-carboxylate (9-AC), and beta(2)-adrenergic agonists, such as ritodrine, in pregnant rat myometrium.

METHODS

Isolated myometrial strips were obtained from eight pregnant rats, and the strips were mounted in organ baths for recording isometric tension. The effects of 10(-8)-10(-4) M ritodrine, 10(-6)-3 x 10(-4) M NPPB, and 10(-6)-10(-3) M 9-AC on spontaneous contractions were recorded.

RESULTS

Ritodrine (10(-8)-10(-5) M) completely inhibited the amplitude and frequency of spontaneous contractions in myometrial strips isolated from pregnant rats in a concentration-dependent manner, but the relaxant effect of ritodrine at 10(-4) M concentration resulted in tachyphylaxis. The chloride channel blocker NPPB (10(-6)-3 x 10(-4) M) and the chloride transport inhibitor 9-AC (10(-5)-10(-3) M) decreased the amplitude of spontaneous myometrial contractions in a concentration-dependent manner; the maximum inhibition produced by the highest tested concentration of each drug was 43.8% and 42.1% of the original degree of spontaneous contractions, respectively. The frequency of myometrial contractions was significantly inhibited by NPPB and 9-AC beginning with the concentration of 10(-4) M.

CONCLUSION

NPPB and 9-AC appear to be effective relaxants of pregnant rat myometrium. These effects of NPPB and 9-AC might be therapeutically advantageous in clinical management of preterm labor.