Usefulness of Diffusion-Weighted Imaging in Evaluating Acute Cellular Rejection and Monitoring Treatment Response in Liver Transplant Recipients

Acute cellular rejection (ACR) is a significant immune issue among recipients following liver transplantation. Although diffusion-weighted magnetic resonance imaging (DWI) is widely used for diagnosing liver disease, it has not yet been utilized for monitoring ACR in patients after liver transplantation. Therefore, the aim of this study was to evaluate the efficacy of DWI in monitoring treatment response among recipients with ACR. This study enrolled 25 recipients with highly suspected ACR rejection, and all subjects underwent both biochemistry and DWI scans before and after treatment. A pathological biopsy was performed 4 to 24 h after the first MRI examination to confirm ACR and degree of rejection. All patients were followed up and underwent a repeated MRI scan when their liver function returned to the normal range. After data acquisition, the DWI data were post-processed to obtain the apparent diffusion coefficient (ADC) map on a voxel-by-voxel basis. Five regions of interest were identified on the liver parenchyma to measure the mean ADC values from each patient. Finally, the mean ADC values and biochemical markers were statistically compared between ACR and non-ACR groups. A receiver operating characteristic (ROC) curve was constructed to evaluate the performance of the ADC and biochemical data in detecting ACR, and correlation analysis was used to understand the relationship between the ADC values, biochemical markers, and the degree of rejection. The histopathologic results revealed that 20 recipients had ACR, including 10 mild, 9 moderate, and 1 severe rejection. The results demonstrated that the ACR patients had significantly lower hepatic ADC values than those in patients without ACR. After treatment, the hepatic ADC values in ACR patients significantly increased to levels similar to those in non-ACR patients with treatment. The ROC analysis showed that the sensitivity and specificity for detecting ACR were 80% and 95%, respectively. Furthermore, the correlation analysis revealed that the mean ADC value and alanine aminotransferase level had strong and moderate negative correlation with the degree of rejection, respectively (r = -0.72 and -0.47). The ADC values were useful for detecting hepatic ACR and monitoring treatment response after immunosuppressive therapy.

Identification of the HNSC88 Molecular Signature for Predicting Subtypes of Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSC) exhibits genetic heterogeneity in etiologies, tumor sites, and biological processes, which significantly impact therapeutic strategies and prognosis. While the influence of human papillomavirus on clinical outcomes is established, the molecular subtypes determining additional treatment options for HNSC remain unclear and inconsistent. This study aims to identify distinct HNSC molecular subtypes to enhance diagnosis and prognosis accuracy. In this study, we collected three HNSC microarrays (n = 306) from the Gene Expression Omnibus (GEO), and HNSC RNA-Seq data (n = 566) from The Cancer Genome Atlas (TCGA) to identify differentially expressed genes (DEGs) and validate our results. Two scoring methods, representative score (RS) and perturbative score (PS), were developed for DEGs to summarize their possible activation functions and influence in tumorigenesis. Based on the RS and PS scoring, we selected candidate genes to cluster TCGA samples for the identification of molecular subtypes in HNSC. We have identified 289 up-regulated DEGs and selected 88 genes (called HNSC88) using the RS and PS scoring methods. Based on HNSC88 and TCGA samples, we determined three HNSC subtypes, including one HPV-associated subtype, and two HPV-negative subtypes. One of the HPV-negative subtypes showed a relationship to smoking behavior, while the other exhibited high expression in tumor immune response. The Kaplan-Meier method was used to compare overall survival among the three subtypes. The HPV-associated subtype showed a better prognosis compared to the other two HPV-negative subtypes (log rank, p = 0.0092 and 0.0001; hazard ratio, 1.36 and 1.39). Additionally, within the HPV-negative group, the smoking-related subgroup exhibited worse prognosis compared to the subgroup with high expression in immune response (log rank, p = 0.039; hazard ratio, 1.53). The HNSC88 not only enables the identification of HPV-associated subtypes, but also proposes two potential HPV-negative subtypes with distinct prognoses and molecular signatures. This study provides valuable strategies for summarizing the roles and influences of genes in tumorigenesis for identifying molecular signatures and subtypes of HNSC.

Combination of Sarcopenia and Anemia Predicts Worse Outcome in Elderly Patients With Diffuse Large B-Cell Lymphoma

BACKGROUND/AIM

In diffuse large B-cell lymphoma (DLBCL), sarcopenia is associated with increased side-effects of chemotherapy and poor survival, especially in elderly patients. Anemia, a complex condition resulting from cancer itself and inflammation, might have a correlation with loss of muscle mass and might also indicate a worse outcome. In this study, we aimed to investigate the association of the skeletal muscle index (SMI) at the third lumbar vertebra (L3) with hemoglobin (Hb) levels and its predictive value for the outcome of DLBCL.

PATIENTS AND METHODS

The study included patients, aged 70 or older, newly diagnosed with DLBCL who received immunochemotherapy. Sex-specific L3-SMI was measured by computed tomography, and Hb levels before treatment were recorded. The Kaplan-Meier method and Cox regression model were used to analyze survival and prognostic factors.

RESULTS

Anemia was correlated with a low SMI. The presence of either low L3-SMI or anemia (Hb <10.5 g/l) indicated a poor prognosis for both progression-free and overall survival. A novel score combining L3-SMI, and Hb and lactate dehydrogenase levels as independent predictive factors was proposed for treatment response, progression-free and overall survival after adjusting for International Prognostic Index.

CONCLUSION

This study highlights the importance of sarcopenia and anemia in patients with DLBCL, particularly in the elderly population. The proposed novel score combining L3-SMI, Hb, and lactate dehydrogenase may provide additional prognostic information for patients with DLBCL, aiding in treatment decisions and management.

Efficacy and Safety of Combined Ethanol-Lipiodol Mixture and Drug-Eluting Bead TACE for Large HCC

Purpose

To evaluate treatment response, survival and safety of a novel TACE using combination of ethanol-Lipiodol mixture and drug-eluting beads in patients with large unresectable HCC, single tumor >8 cm or multiple tumors with the largest tumor diameter >5 cm and total tumor diameter >10 cm.

Patients and Methods

Between June 2016 and February 2020, a total of 27 patients were enrolled in this retrospective cohort study. Treatment response was assessed at first month after the treatment; progression-free survival (PFS) and overall survival (OS) were evaluated. The prognostic factors associated with patient survival were statistically analyzed by the Cox regression model. Adverse events were recorded.

Results

The maximum diameter of the tumors ranged from 5 cm to 17 cm (mean 10.48 cm). The objective response and disease control rates were 56% and 78%, respectively, at 1-month follow-up. The median survival time was 15.9 months (95% CI, 9.03-34.76 months). The OS rates were 76.9% at six months, 65.2% at one year and 44.8% at two years. AFP >400 ng/mL (p = 0.0306), maximum tumor size >10cm (p = 0.0240) were potential risk factors for OS. Regarding safety, major complications occurred in one patient (1/27, 3.7%), presenting with transient hepatic encephalopathy.

Conclusion

Combined DEB-TACE appeared to have favorable objective tumor response. It can be an effective treatment option for large unresectable HCC.

Discovery of moiety preference by Shapley value in protein kinase family using random forest models

Background

Human protein kinases play important roles in cancers, are highly co-regulated by kinase families rather than a single kinase, and complementarily regulate signaling pathways. Even though there are > 100,000 protein kinase inhibitors, only 67 kinase drugs are currently approved by the Food and Drug Administration (FDA).

Results

In this study, we used “merged moiety-based interpretable features (MMIFs),” which merged four moiety-based compound features, including Checkmol fingerprint, PubChem fingerprint, rings in drugs, and in-house moieties as the input features for building random forest (RF) models. By using > 200,000 bioactivity test data, we classified inhibitors as kinase family inhibitors or non-inhibitors in the machine learning. The results showed that our RF models achieved good accuracy (> 0.8) for the 10 kinase families. In addition, we found kinase common and specific moieties across families using the Shapley Additive exPlanations (SHAP) approach. We also verified our results using protein kinase complex structures containing important interactions of the hinges, DFGs, or P-loops in the ATP pocket of active sites.

Conclusions

In summary, we not only constructed highly accurate prediction models for predicting inhibitors of kinase families but also discovered common and specific inhibitor moieties between different kinase families, providing new opportunities for designing protein kinase inhibitors.

Use of blood oxygen level-dependent magnetic resonance imaging to detect acute cellular rejection post-liver transplantation

OBJECTIVES

Acute cellular rejection (ACR) is a major immune occurrence post-liver transplant that can cause abnormal liver function. Blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) can be used to evaluate liver disease, but it has not been utilized in the diagnosis of ACR post-liver transplant. Therefore, the purpose of this study is to evaluate the diagnostic performance of BOLD MRI and to monitor treatment response in recipients with ACR.

METHODS

This prospective study was approved by the local institutional review board. Fifty-five recipients with highly suspected ACR were enrolled in this study. Each patient underwent hepatic BOLD MRI, blood biochemistry, and biopsy before treatment. Of 55 patients, 19 recipients with ACR received a follow-up MRI after treatment. After obtaining the R2* maps, five regions-of-interest were placed on liver parenchyma to estimate the mean R2* values for statistical analysis. Receiver operating characteristic curve (ROC) analysis was performed to assess the diagnostic performance of R2* values in detecting patients with ACR.

RESULTS

The histopathologic results showed that 27 recipients had ACR (14 mild, 11 moderate, and 2 severe) and their hepatic R2* values were significantly lower than those of patients without ACR. ROC analysis revealed that the sensitivity and specificity of the R2* values for detection of ACR were 82.1% and 89.9%, respectively. Moreover, the R2* values and liver function in patients with ACR significantly increased after immunosuppressive treatment.

CONCLUSION

The non-invasive BOLD MRI technique may be useful for assessment of hepatic ACR and monitoring of treatment response after immunosuppressive therapy.

KEY POINTS

• Patients with acute cellular rejection post-liver transplant exhibited significantly decreased R2* values in liver parenchyma. • R2* values and liver function were significantly increased after immunosuppressive therapy. • R2* values were constructive indicators in detecting acute cellular rejection due to their high sensitivity and specificity.

Portosystemic Shunt in Pediatric Living Donor Liver Transplant

BACKGROUND

To evaluate the significance of portosystemic shunts and associated long-term outcomes in living donor liver transplant (LDLT) among pediatric patients.

METHODS

Retrospective review of 121 pediatric patients who underwent LDLT between May 1994 and December 2015 at Taiwan Kaohsiung Chang Gung Memorial Hospital. Pre- and postoperative computed tomography images of the liver were reviewed, and portal vein complications were assessed.

RESULTS

Ninety-seven pediatric patients were included in the study, and 70 had portosystemic shunts before transplant. Thirty-three patients have portal systemic shunt (PSS) 6 months after transplant (mean [SD] shunt size, 4.59 [1.98] mm). Thirty-seven patients' portosystemic shunts closed spontaneously (mean [SD] shunt size, 3.14 [1.06] mm). Smaller PSSs tend to close spontaneously with a cutoff point of 3.35 mm by receiver operating characteristic curve (P = .01). Patients with PSS have more portal vein complications than those without PSS (44.3% vs 11.1%, P = .02). Among PSS recipients, patients with portal vein complications tend to have larger PSS size (mean [SD], 4.14 [1.96] mm vs 3.59 [1.48] mm), although the difference is not statistically significant (P = .19).

CONCLUSIONS

In pediatric patients, preoperative portosystemic shunts are significantly correlated with portal venous complications, some of which require minimal interventions after LDLT with good outcomes. Shunts larger than 3.35 mm tend to persist after transplant with increased portal venous complications.

Clinical Impact of Gadoxetic Acid-Enhanced Magnetic Resonance Imaging on Living Donor Liver Transplant

BACKGROUND

Gadolinium-ethoxybenzyl-diethylene triamine pentaacetic acid (Gd-EOB-DTPA) is a newer magnetic resonance contrast that has the combined effect of conventional and liver-specific contrast. The use of Gd-EOB-DTPA may aid in management of patients with hepatocellular carcinoma (HCC) undergoing living donor liver transplant (LDLT).

MATERIALS AND METHODS

We retrospectively reviewed all HCC patients who received LDLT with Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) as part of a pretransplant evaluation between October 2012 and October 2016. The detection rate and impact on decision making were assessed between multidetector-row computed tomography (MDCT) and Gd-EOB-DTPA-enhanced MRI with pathology of the explanted liver being the reference standard.

RESULTS

We analyzed 25 patients with 80 nodules. Gd-EOB-DTPA-enhanced MRI showed superior detection rate for HCCs than MDCT (76.1% vs 35.8%). Among the 25 patients, 16 had additional HCCs detected by Gd-EOB-DTPA-enhanced MRI, which led to changes in therapeutic decisions in 11 patients. The recurrence rate and mortality rate were 4% (1 of 25). In the same period in our institution, the mortality rate was 13.9% (25 of 180) for those who did not receive Gd-EOB-DTPA-enhanced MRI as part of the pretransplant evaluation.

CONCLUSIONS

The use of Gd-EOB-DTPA-enhanced MRI can aid in characterization of indeterminate nodules and detect more HCCs and thus more adequate downstaging and pretransplant neoadjuvant treatment ensue, which may lower the recurrence rate after LDLT.

An integrated systematic approach for investigating microcurrent electrical nerve stimulation (MENS) efficacy in STZ-induced diabetes mellitus

Diabetes mellitus (DM) is a major metabolic disorder and an increasing health problem worldwide. Effective non-invasive therapies for DM are still lacking. Here, we have developed Microcurrent electrical nerve stimulation (MENS), a non-invasive therapy, and tested on 46 mice clustered into five groups, such as control, STZ-induced DM, and MENS treatment groups. Experimental results show that MENS treatment is able to improve seven biochemical indexes (e.g., hemoglobin A1c and glucose level). To investigate the mechanisms of MENS treatment on STZ-induced DM, we selected six representative samples to perform microarray experiments for several groups and developed an integrated Hierarchical System Biology Model (HiSBiM) to analyze these omics data. The results indicate that MENS can affect fatty acid metabolism pathways, peroxisome proliferator-activated receptor (PPAR) signaling pathway and cell cycle. Additionally, the DM biochemical indexes and omics data profiles of MENS treatment were found to be consistent. We then compared the therapeutic effects of MENS with anti-diabetic compounds (e.g., quercetin, metformin, and rosiglitazone), using the HiSBiM four-level biological functions and processes of multiple omics data. The results show MENS and these anti-diabetic compounds have similar effect pathways highly correlated to the diabetes processes, such as the PPAR signaling pathway, bile secretion, and insulin signaling pathways. We believe that MENS is an effective and non-invasive therapy for DM and our HiSBiM is an useful method for investigating multiple omics data.

154 Enhancing Communication Between Foundation Doctors and Radiologists

Introduction

Facilitating radiological imaging for patients is an essential task for all Foundation Year (FY) doctors. Achieving competence in this task can expedite patient management. We evaluated the confidence and skills of FYs in facilitating radiological imaging before and after introduction of formal training.

Method

Surgical FYs working at a teaching hospital were surveyed to evaluate their baseline level of competence in booking and discussing imaging with radiology colleagues. Parameters were measured on a Likert scale, including confidence in discussing requests and satisfaction of their own performance following discussions. Eight radiology consultants were surveyed to evaluate their opinions on FYs’ communication and established areas for improvement. A teaching session was then delivered to improve communication skills. Furthermore, PACCSS poster was introduced to remind the FYs of the salient information required when discussing imaging.

Results

One month after the intervention, the participants were re-surveyed. This demonstrated a statistically significant improvement in self-reported confidence from 5.3/10 to 7.3/10 (p &lt; 0.001), and in satisfaction of own performance from 5.4/10 to 7.0/10 (p &lt; 0.001).

Conclusions

We identified deficiencies in surgical FY doctors’ confidence and skills in facilitating radiological imaging. There was a demonstrable benefit with focused training. Inter-specialty communication should be introduced into under- and post-graduate educational curriculum.

CoMI: consensus mutual information for tissue-specific gene signatures

Background

The gene signatures have been considered as a promising early diagnosis and prognostic analysis to identify disease subtypes and to determine subsequent treatments. Tissue-specific gene signatures of a specific disease are an emergency requirement for precision medicine to improve the accuracy and reduce the side effects. Currently, many approaches have been proposed for identifying gene signatures for diagnosis and prognostic. However, they often lack of tissue-specific gene signatures.

Results

Here, we propose a new method, consensus mutual information (CoMI) for analyzing omics data and discovering gene signatures. CoMI can identify differentially expressed genes in multiple cancer omics data for reflecting both cancer-related and tissue-specific signatures, such as Cell growth and death in multiple cancers, Xenobiotics biodegradation and metabolism in LIHC, and Nervous system in GBM. Our method identified 50-gene signatures effectively distinguishing the GBM patients into high- and low-risk groups (log-rank p = 0.006) for diagnosis and prognosis.

Conclusions

Our results demonstrate that CoMI can identify significant and consistent gene signatures with tissue-specific properties and can predict clinical outcomes for interested diseases. We believe that CoMI is useful for analyzing omics data and discovering gene signatures of diseases.

Diffusion-weighted imaging for identifying patients at high risk of tumor recurrence following liver transplantation

Background

Tumor recurrence is the major risk factor affecting post-transplant survival. In this retrospective study, we evaluate the prognostic values of magnetic resonance (MR) diffusion-weighted imaging (DWI) in liver transplantation for hepatocellular carcinoma (HCC).

Methods

From April 2014 to September 2016, 106 HCC patients receiving living donor liver transplantation (LDLT) were enrolled. Nine patients were excluded due to postoperative death within 3 months and incomplete imaging data. The association between tumor recurrence, explant pathologic findings, and DWI parameters was analyzed (tumor-to-liver diffusion weighted imaging ratio, DWI_T/L; apparent diffusion coefficients, ADC). The survival probability was calculated using the Kaplan–Meier method.

Results

Sixteen of 97 patients (16%) developed tumor recurrence during the follow-up period (median of 40.9 months; range 5.2–56.5). In those with no viable tumor (n = 65) on pretransplant imaging, recurrence occurred only in 5 (7.6%) patients. Low minimum ADC values (p = 0.001), unfavorable tumor histopathology (p <  0.001) and the presence of microvascular invasion (p <  0.001) were risk factors for tumor recurrence, while ADC_mean (p = 0.111) and DWI_T/L (p = 0.093) showed no significant difference between the groups. An ADC_min ≤ 0.88 × 10^− 3 mm²/s was an independent factor associated with worse three-year recurrence-free survival (94.4% vs. 23.8%) and overall survival rates (100% vs. 38.6%).

Conclusions

Quantitative measurement of ADC_min is a promising prognostic indicator for predicting tumor recurrence after liver transplantation.

Predicting post-hepatectomy liver failure by combined volumetric, functional MR image and laboratory analysis

BACKGROUND & AIMS

To assess the efficacy of functional MR image with volumetric, liver function test and indocyanine green clearance (ICG) in identifying the patients who are at risk of post-hepatectomy liver failure (PHLF).

METHODS

We retrospectively included 115 patients undergoing gadoxetic acid-enhanced MR imaging before hepatectomy at one medical centre from January 2013 to December 2015. Contrast enhancement ratio (CER) between transitional and hepatobiliary phases (3 and 30 minutes post-contrast) was calculated. Total liver volume (TLV) and spleen volume (Sp) were measured. Post-operatively, the histological Ishak fibrosis score was collected. Potential risk factors for liver failure were analysed, and the performance was examined by receiver operating characteristic curve.

RESULTS

Post-hepatectomy liver failure (PHLF) occurred in 16 patients (13.9%). TLV/SLV, ADC value, CER_HBP/TP and total liver contrast enhancement ratio (tCER) were associated with PHLF (P < .05). Between PHLF and non-PHLF groups, remnant liver volume (RLV), RLV/SLV, Sp/RLV, remnant liver contrast enhancement ratio (rCER) and Ishak fibrosis score showed statistical difference. rCER showed superiority in diagnostic performance (AUC = 0.78) with the optimal cut-off value of 1.23.

CONCLUSIONS

Gadoxetic acid-enhanced MR imaging with volumetric is a reliable method for evaluating functional liver volume and determining the risk of PHLF.

The novel synthesized 6-fluoro-(3-fluorophenyl)-4-(3-methoxyanilino)quinazoline (LJJ-10) compound exhibits anti-metastatic effects in human osteosarcoma U-2 OS cells through targeting insulin-like growth factor-I receptor

Our previous study demonstrated that 6-fluoro-(3-fluorophenyl)-4-(3-methoxyanilino)quinazoline (LJJ-10) possesses potential anticancer activity and exhibits greater antitumor effect than the other quinazoline compounds in human osteogenic sarcoma U-2 OS cells via in vitro screening. In this study, we focused on investigating the anti-metastatic activity and the signaling pathways involved in LJJ-10 action in U-2 OS cells. The results from wound healing and Boyden chamber transwell assays indicated that LJJ-10 exhibited an inhibitory effect on the migration and invasion of U-2 OS cells. LJJ-10 also inhibited matrix metalloproteinase-2 (MMP-2) and MMP-9 enzyme activities and caused a concentration-dependent decrease in protein levels by gelatin zymography assay and Western blot analysis, respectively. Meanwhile, LJJ-10 suppressed MMP-2 and MMP-9 mRNA levels in a concentration-dependent fashion after 12-h exposure in U-2 OS cells. Computational modeling showed that LJJ-10 is bound into the IGF-1R via hydrophobic interactions with Leu975, Val983, Ala1001, Glu1050 and Met1052 with one hydrogen bond between 6-F and Met1052. LJJ-10 reduced the protein levels of p-JNK, p-p38, p-ERK, p-AKT and p-IGFR by Western blotting and these influences are concentration-dependent. Based on these observations, this study suggests that molecular targeting of the insulin-like growth factor-I receptor (IGF-1R) signaling leads to the suppression of downstream MAPK/AKT signaling and downregulation of MMP-2 and -9 RNA levels and protein levels in LJJ-10-treated U-2 OS cells. Therefore, the inhibition of metastasis in human osteosarcoma cells by treatment with this novel agent, LJJ-10 may be a useful chemotherapeutic approach.

The synthesized novel fluorinated compound (LJJ-10) induces death receptor- and mitochondria-dependent apoptotic cell death in the human osteogenic sarcoma U-2 OS cells

We designed the 6-fluoro-2-(3-fluorophenyl)-4-substituted anilinoquinazoline derivatives as less toxic anti-cancer candidates. Our result demonstrated that LJJ-10 has greater cytotoxicity than that of the other compounds in human osteogenic sarcoma U-2 OS cells. LJJ-10-induced apoptosis was associated with enhancing ROS generation, DNA damage, and an increase of the protein levels of Fas, FasL, FADD, caspase-8, cytochrome c, Apaf-1, AIF, Endo G, caspase-9 and caspase-3 in U-2 OS cells. LJJ-10-triggered growth inhibition was significantly attenuated by N-acetylcysteine, cyclosporine A, anti-FasL monoclonal antibody, and caspase-8, -9 and -3 specific inhibitors in U-2 OS cells. We suggest that LJJ-10-induced apoptotic cell death in U-2 OS cells through death receptor- and mitochondria-dependent apoptotic signaling pathways.

Amphotericin B up-regulates angiogenic genes in hepatocellular carcinoma cell lines

BACKGROUND

Amphotericin B (AmB) has a discordant influence on epirubicin (4'-epidoxorubicin) cytotoxicity in hepatocellular carcinoma (HCC). This indicates that the cellular function of HCC may be significantly influenced by AmB. Whether the influence of AmB on HCC has any possibility to influence cancer growth has not been studied. This study was to try and clarify this issue.

MATERIALS AND METHODS

Two HCC cell lines including one without augmentation of the epirubicin cytotoxicity by AmB (cell line A; HCC24/KMUH) and one with this effect (cell line B; HCC38/KMUH) were studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and whole human genome microarray (experimental group: 2.5 microg mL(-1) AmB).

RESULTS

Differential expressions of genes induced by AmB in two cell lines had no influence on cell proliferation as determined by MTT assay. Only cell line B showed up-regulation of genes related to oxidative stress, acute phase reaction, cytokine-cytokine receptor interaction and complement and coagulation cascades. Among the chemokine genes up-regulated by AmB, five genes (CCL2, CXCL1, CXCL5, CXCL6, IL8) were angiogenic. Cell line B also showed up-regulation of one angiogenic C10orf10 gene and down-regulation of one angiostatic chemokine gene (CXCL10). Up- or down-regulation of other genes in cell line A and B did not show any evidence to promote angiogenesis.

CONCLUSION

AmB has the capacity to concomitantly up-regulate angiogenic genes in HCC cells susceptible to AmB-induced oxidative stress.

Alterations in the basement membrane zone in pili annulati hair follicles as demonstrated by electron microscopy and immunohistochemistry

BACKGROUND

Pili annulati is a rare autosomal dominant inherited hair shaft abnormality in which clinical examination reveals alternating light and dark bands leading to a shiny appearance of the hair. The clinically light bands are the abnormal areas due to cavities within the cortex. The pathogenesis remains unknown.

OBJECTIVES

To investigate the expression of the basement membrane zone (BMZ) components in pili annulati hair follicles of the scalp.

METHODS

Transmission electron microscopy (TEM) was carried out on scalp sections of six individuals with pili annulati and six controls. Longitudinal sections of scalp tissues from four individuals with pili annulati and six normal controls were studied by immunohistochemistry with a panel of monoclonal antibodies to the following BMZ components: alpha(6)beta(4) integrin, laminin 5, LH39 antigen, laminin 1, collagen IV and collagen VII.

RESULTS

Using TEM, pili annulati scalp specimens exhibited a reduplicated lamina densa in the region of the root bulb in comparison with the single thin electron-dense band in controls. Using immunohistochemistry, there was a wavy BMZ in pili annulati follicles with antibodies to components of the lamina lucida, lamina densa and anchoring fibrils, whereas the BMZ in control hair follicles was as a smooth linear band. The expression of the hemidesmosome-associated alpha(6)beta(4) integrin was linear in both pili annulati and control hair follicles.

CONCLUSIONS

Our results suggest that the genetic defect may be a mutation in proteins involved in signalling and regulation of formation and degradation of the lamina densa and sublamina densa region resulting in abnormal assembly or remodelling of the BMZ.

Comparison between the expression of basement membrane zone antigens of human interfollicular epidermis and anagen hair follicle using indirect immunofluorescence

BACKGROUND

The composition of the basement membrane zone (BMZ) or dermal-epidermal junction in the interfollicular skin has been well documented. However, little is known about the BMZ or connective tissue-epithelial junction along the hair follicle.

OBJECTIVES

To determine whether the BMZ antigens in the interfollicular epidermis are also present in the BMZ of the anagen hair follicle and to compare whether the expression and distribution of the BMZ components vary between the interfollicular epidermis and the anagen follicle and within different regions of the hair follicle.

METHODS

Longitudinal cryostat sections of scalp margin specimens from four adult patients undergoing cosmetic surgery, and without known pathology were stained with a panel of monoclonal and polyclonal antibodies to different BMZ constituents using standard indirect immunofluorescence.

RESULTS

All the BMZ antigens found in the normal interfollicular epidermis were expressed in the anagen follicle; however, there were regional variations in the intensity and patterns of fluorescence. All the antigens were expressed in a continuous linear pattern along the BMZ of the interfollicular skin, the infundibulum, and the middle part of the hair follicle. Differences were observed in the lower follicle and the hair bulb. There was continuous expression throughout the BMZ of the follicle of laminin-1 and collagen IV, but in contrast, expression of other antigens decreased down the lower follicle. There was weak or even negative staining with antibodies to alpha 6 beta 4 integrin, laminin-5, anchoring filaments, and type VII collagen in the outer aspect of the bulb compared with the hair papilla. In addition, there were special patterns observed along the bilateral middle and lower follicle.

CONCLUSIONS

Despite the common embryological origin between the interfollicular epidermis and the hair follicle, there is variation in the expression of the BMZ antigens. This may be explained by the histological specialization and functional requirements that reflect the dynamic hair growth cycle.

Spinal anesthesia in MELAS syndrome: a case with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes

MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) is one of the classic mitochondrial encephalomyopathies with variable clinical presentation and multisystem involvement. Enhanced sensitivity to neuromuscular blockade or anesthetic agents and susceptibility to malignant hyperthermia in these patients have ever been reported, all of which complicate the management of general anesthesia. To avoid these appalling troubles in general anesthesia, we chose spinal anesthesia for a patient with MELAS syndrome receiving appendectomy. The patient obtained adequate anesthesia and good recovery without neurologic sequelae. Although there is little information about the application of regional anesthesia in MELAS patients, we demonstrate that it may be a satisfactory choice. However, it is suggested that regional anesthesia is performed only when neurological abnormalities of spinal cord or peripheral nerves are definitely ruled out.

Tissue damage and regeneration of ureteric smooth muscle in rats with obstructive uropathy

OBJECTIVE

To investigate regeneration in obstructed ureters and to elucidate the role of hyperplasia in the thickening of the smooth muscle layer in the late stages of complete ureteric obstruction.

MATERIALS AND METHODS

The expression of Ki-67 antigen, c-Fos, c-Jun and c-Myc in the smooth muscle layer of obstructed ureters was determined using immunohistochemistry in 40 Sprague-Dawley rats. After unilateral ligation of the ureter, five rats each were killed for examination at 1, 3, 7, 10, 14, 21, 28 and 42 days after ligation: dive rats that underwent a sham operation were also examined as controls.

RESULTS

The severity of hydroureter and thickening of the smooth muscle layer progressed consistently in the ligated ureters, but no mitosis was detected in myocytes within 14 days of ligation. Fibrosis in the smooth muscle layer appeared 21 days after ligation and progressed. There was no expression of Ki-67 antigen and oncoproteins until 14 days after ligation. The expression of Ki-67 and c-Myc increased gradually to a peak after 28 days, then declined. However, the expression of c-Fos and c-Jun was low and transient.

CONCLUSION

Cell regeneration is impaired in the damaged muscle layer of obstructed ureters. Only hypertrophy and not hyperplasia of the smooth muscle layer developed during the course of complete ureteric obstruction in this rat model of obstructive uropathy.

Early genetic and cellular responses in the smooth muscle layer of obstructed ureters in a rat model of obstructive uropathy

OBJECTIVE

To investigate the early genetic and cellular responses in the smooth muscle layer of completely obstructed ureters, and to determine whether myocytes proliferate (hyperplasia) in the ureters during the early stage of obstructive uropathy.

MATERIALS AND METHODS

The study comprised 35 female Sprague-Dawley rats which had undergone unilateral ligation of their ureters. After ureteric ligation, five rats each were killed and examined at 0.5, 1, 2, 4, 8, 16 and 24 h after ligation. The proximal portion of the ureters was prepared for light and electron microscopy. The expression of c-Fos, c-Jun, c-Myc and Ki-67 antigen was assessed immunohistochemically.

RESULTS

c-Fos and c-Jun were detected 2 h after ligation and the expression of these two proteins reached a maximum after 4 h, becoming undetectable 16 h after ligation. The expressions of c-Fos and c-Jun were strongly correlated (r = 0.9854, P < 0.001). The expressions were of c-Myc and Ki-67 antigen was not detected within 24 h after ureteric ligation. The amount of rough endoplasmic reticulum (rER) in the ligated ureters increased soon after complete ligation and the increase continued throughout the period of ureteric obstruction (r = 0.9699, P < 0.001). The change in rER was also significantly correlated with the expression of c-Fos and c-Jun within 8 h after ligation.

CONCLUSION

The expression of c-Fos and c-Jun, but not c-Myc, might contribute to the hypertrophy of the ureteric smooth muscle layer during the course of complete ureteric obstruction. There is no hyperplasia in ureteric smooth muscle in the early stages of obstructive uropathy.

Simultaneous occurrence of papulonecrotic tuberculide and erythema induratum and the identification of Mycobacterium tuberculosis DNA by polymerase chain reaction

The simultaneous occurrence of two tuberculides in one patient is rare. We report the case of a 32-year-old man presenting with both papulonecrotic tuberculide and erythema induratum. Mycobacterial DNA was identified from both skin lesions by polymerase chain reaction using formalin-fixed and paraffin-embedded tissues, suggesting that tuberculides are related to tuberculosis. New skin lesions developed after the patient discontinued his medication on his own initiative, 2 months after triple antituberculous therapy had been started. It is important to continue therapy for a prolonged period.

Immune effector cells induced by complete Freund's adjuvant exert an inhibitory effect on antigen-specific type 2 T helper responses

BACKGROUND

It has been well documented that environmental factors such as antigenpresenting cells and related cytokines could affect the development of T helper cells.

OBJECTIVE

The purpose of this study is to investigate the effect of different adjuvants on T cell development.

METHODS

Ovalbumin (OVA) combined with aluminum hydroxide (Alum) plus pertussis toxin (PT) or complete Freund's adjuvant (CFA) were used to sensitize mice; the production of IgG and IgE anti-OVA antibodies was then followed. In addition, OVA-specific proliferative responses and cytokine production by spleen cells were also investigated.

RESULTS

The data showed that the adjuvants themselves could modify the pattern of immune response: (1) IgG2a anti-OVA antibody was higher in mice sensitized with OVA + CFA compared to that of mice sensitized with OVA + Alum + PT; (2) the ratio of IFN-gamma/IL-4 produced by OVA-stimulated spleen cells was higher in mice sensitized with OVA + CFA than that of mice sensitized with OVA + Alum + PT: (3) increased percentage of gamma delta T cells was noted in the peritoneal exudate cells of OVA + CFA immunized mice; and (4) the immune response of mice sensitized with OVA + Alum + PT was inhibited by the adoptively transferred ascitic cells from OVA + CFA immunized mice.

CONCLUSION

In general, the data suggested higher IgG2a and the ratio of IFN-gamma/IL-4 was noted in mice sensitized with OVA + CFA. Further elucidation of the regulatory mechanism of allergen-specific T helper cells development and exploration of possible agents for immunotherapy might shed light on the management of atopic diseases.

Influence of furosemide on the ureteric damage in a rat model of obstructive uropathy

Furosemide has been used in the diuretic renography and diuretic radionuclide scan to evaluate the severity of hydroureter and hydronephrosis. To elucidate the influence of furosemide on obstructed ureters, unilateral ligation of ureter was performed in 45 rats. Twenty-four of the rats received intramuscular injections of furosemide (6 mg/kg/day) after the third day postligation. Eight rats were sacrificed for examination on days 7, 10 and 14 after ligation, respectively. The remaining 21 untreated rats were also sacrificed for comparison. The severity of hydroureter and hydronephrosis in the ligated side of the furosemide-treated rats was significantly higher than that of the untreated rats. However, the histological changes in the treated and untreated rats showed no significant difference. The ultrastructural alterations aggravated along the course of ureteric obstruction. Intriguingly, the ultrastructural changes were significantly milder in the treated rats. We conclude that the administration of furosemide might increase the severity of hydroureter, but it does not accelerate the ureteric damage of the obstructed ureters.

Different kinds of antigen-presenting cells exert different effects on T-helper cells development

It has been well documented that environmental factors such as antigen-presenting cells and related cytokines can affect the development of T-helper cells. The purpose of this study was to investigate the role of different antigen-presenting cells on T-cell development. Ovalbumin (OVA) combined with complete Freud's adjuvant (CFA) was used to sensitize mice subcutaneously or intraperitoneally, and then to follow-up production of IgG and IgE anti-OVA antibodies. In addition, semiquantitative PCR was used to determine the level of cytokine mRNA of different antigen-presenting cells. Resulting data showed that antigen-presenting cells expressed with different characteristics: (1) IgG2a anti-OVA antibody was higher in mice sensitized subcutaneously compared to those sensitized intraperitoneally. (2) The levels of cytokine mRNA were higher in antigen-stimulated spleen cells of mice immunized subcutaneously compared to those of mice immunized intraperitoneally. (3) Langerhans cells expressed a high level of IL-12; in contrast, peritoneal B cells expressed a high level of IL-10, but not IL-12. In summary, cytokine levels such as IL-10 and IL-12 were different among different kinds of APC, and their role in production of different isotypes of antibodies needs further elucidation.

In vitro and in vivo functional analysis of CD5+ and CD5- B cells of autoimmune NZB x NZW F1 mice

Polyclonal B cell activation has been thought to play the critical role in production of autoantibodies, and possible activation of autoreactive T cells in murine lupus, especially abnormal expansion of CD5+ B cells, is one of the characteristic findings in these mice. The aim of this study was to investigate further the characteristics and function of CD5+ and CD5- B cells. Both CD5+ and CD5- B cells were isolated for in vitro autoantibody production, cytokine expression and in vivo anti-DNA antibody production with reconstitution of severe combined immunodeficient (SCID) mice. The data showed: (i) both CD5+ and CD5- B cells produced a high level of anti-DNA antibody after stimulation with lipopolysaccharide (LPS) plus IL-5; (ii) both peritoneal CD5+ and CD5- B cells expressed a high level of IL-10 mRNA after stimulation with LPS, while in contrast CD5- B cells of non-autoimmune BALB/c mice did not express IL-10 mRNA after stimulation; (iii) SCID mice reconstituted with either CD5+ or CD5- B cells all produced significant levels of anti-DNA antibodies in vivo and manifested with proteinuria. These data suggest both CD5+ and CD5- B cells play important roles in polyclonal B cell activation and subsequent autoantibody production. Generalized polyclonal B cell activation, instead of expanding a certain subpopulation of B cells, contributed to the pathogenesis of autoimmunity in murine lupus.

Change of chemokines during immunotherapy in asthmatic children

Histamine-releasing factor (HRF) consists of a group of cytokines that can cause basophil/mast cell to release histamine, however, the composition of HRF still remains undefined. This study was designed to measure the concentrations of chemokines in asthmatic children receiving immunotherapy. Peripheral blood mononuclear cells culture supernatants were obtained from six asthmatic children before and four, eight months after immunotherapy (IT). The levels of monocyte chemotactic and activating factor (MCAF), macrophage inflammatory protein-1a (MIP-1a), regulated on activation normal T-cell expressed and secreted (RANTES) and interleukin-8 (IL-8) spontaneously and after stimulation with PHA and mite allergen in the supernatants. The data showed: 1) The levels of MCAF and MIP-1a increased four months, and decreased eight months, after IT; 2) By contrast, the level of RANTE increased after IT; 3) The level of IL-8 also tended to increase after IT. Abnormal chemokine production may contribute to the pathogenesis of bronchial asthma and restoration of normal chemokine production may be used to partially explain the clinical efficacy of immunotherapy.

Growth characteristics of normal and dystrophic myoblasts in primary myoblast cultures

This study employed immunocytochemistry and toluidine blue counterstaining to compare different procedures utilized in primary myoblast cultures, from which an optimal culture model for normal myoblasts could be derived. The growth characteristics of normal and dystrophic myoblasts were also investigated by means of this model. Results indicate that the requirements for an ideal myoblast culture should include a combined enzyme of 0.25% trypsin and 0.2% collagenase (type IV) (1:1), a preplating time of approximately 15-20 minutes, and a seeding density of 1 x 10(5) cells/ml. Furthermore, the mouse samples should be newborn mice. A better proliferative capacity of myoblasts was noted in an incubator with 10% CO2 coupled with Dulbecco's MEM plus 15% fetal calf serum. With regard to the growth characteristics of normal and dystrophic myoblasts, the doubling time of normal myoblasts was shorter than that of dystrophic myoblasts. In terms of the fusion percentage of myoblasts, dystrophic myoblasts tended to fuse earlier than normal ones, especially after 5 days in culture. The findings of this study are valuable in understanding the myogenesis of myoblasts under different culture conditions. The establishment of requirements for good growth of myoblast cultures will facilitate myoblast transfer therapy. Finally, the growth characteristics of normal and dystrophic myoblasts as well as variances in the proliferation and differentiation of these two types of cells are clarified.

CPEO and carnitine deficiency overlapping in MELAS syndrome

Mitochondrial myopathy, encephalopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome is one of the mitochondrial encephalomyopathies that has distinct clinical features including stroke-like episodes with migraine-like headache, nausea, vomiting, encephalopathy and lactic acidosis. We report a 27-year-old woman who presented with partial seizure, stroke-like episodes including hemiparesis, hemianopia and hemihypethesia, sensorineural hearing loss, migraine-like headache, and lactic acidosis. Brain computed tomographic scan showed encephalomalacia in the right parieto-occipital area and recent hypodensity in the left temporoparieto-occipital area with cortical atrophy. Muscle biopsy revealed ragged-red fibers and paracrystaline inclusions in the mitochondria. Genetic study revealed an A to G point mutation at nucleotide position (np) 3243 of mitochondrial DNA. External ophthalmoplegia and ptosis were also found during two exaggerated episodes in this patient. Therefore, the overlapping syndrome of chronic progressive external ophthalmoplegia in the MELAS syndrome is considered in this case. Furthermore, we also found carnitine deficiency in this patient and she was responsive well to steroid therapy. Muscle biopsy also revealed excessive lipid droplets deposits. Therefore, the carnitine deficiency may occur in MELAS syndrome with the A to G point mutation at np 3243. We recommend the steroid or carnitine supplement therapy be applied to the MELAS syndrome with carnitine deficiency.

The temporal relationship between the severity of hydroureter and the dynamic changes of obstructed ureters in a rat model

OBJECTIVE

To investigate dynamic changes in the obstructed rat ureter and to evaluate the usefulness of the rat model in the study of obstructive uropathy.

MATERIALS AND METHODS

Unilateral ligation of the ureter was performed in 26 rats. After ureteric ligation, four to seven rats were killed and examined after 1, 3, 7, 10, and 14 days. The severity of hydroureter and hydronephrosis was assessed by pyelography and the hydroureter-hydronephrosis index. The middle portion of the ureter was prepared for light and electron microscopic observation. Five rats which received a sham operation were also examined as controls.

RESULTS

The severity of hydroureter and hydronephrosis in the ligated ureters progressively increased during the period of obstruction (P < 0.005) and reached a maximum 10-14 days after ligation. Hypertrophy of the smooth muscle layer developed on the third day after ligation and proliferation of submucosal connective tissue occurred on the 10th day after ligation. The changes in smooth muscle and connective tissue layers also progressed consistently during ureteric obstruction (P < 0.001 and < 0.005, respectively). The number and size of granular endoplasmic reticulum and Golgi apparatus in the smooth muscle cells increased after ureteric ligation and then caveolae exocytosis developed. Deposition of collagen fibres between muscle cells became apparent later.

CONCLUSION

The rat model of hydrouropathy demonstrated a clear temporal relationship between the severity of hydroureter and the dynamic changes in the obstructed ureter and could be used as a conventional method for the study of obstructive ureter.

MELAS syndrome associated with diabetes mellitus and hyperthyroidism: a case report from Taiwan

MELAS syndrome is a form of mitochondrial myopathy with manifestations of seizure, stroke-like syndrome, lactic acidosis, ragged red muscle fibres and mitochondrial encephalopathy. The syndrome has been reported in association with a variety of endocrine and metabolic disorders including diabetes mellitus (DM), hypothalamo-pituitary hypofunction, hypothalamic growth hormone deficiency and delayed puberty. Mitochondrial DNA (mtDNA) point mutation may be the major pathological defect. However, association of MELAS syndrome with hyperthyroidism has not previously been reported. A case is reported from Taiwan of a 32-year-old woman suffering from MELAS syndrome with associated DM and hyperthyroidism. When the latter was diagnosed in April 1988, the patient underwent subtotal thyroidectomy. There was no family history of thyroid disease. Because of repeated seizures, she had computed tomography (CT) and magnetic resonance imaging (MRI) of the brain which showed focal, low-density lesions over the cerebral hemispheres. Both serum and cerebral spinal fluid lactic acid levels were elevated. Mild elevations of serum T4 and T3 and a high titre of TSH receptor antibody were still present. Hyperglycaemia was noted during hospitalization and DM confirmed by oral glucose tolerance test. Muscle biopsy showed ragged red fibres. DNA analysis showed an A-to-G transition at the 3243rd nucleotide position of the tRNA(Leu(UUR)) gene of the mtDNA from the patient. Quantitative polymerase chain reaction (PCR) and restriction analysis revealed that about 60% of the blood mtDNA was of mutant type. The patient received antithyroid drugs for hyperthyroidism, diet control for DM and anti-epileptic drugs for seizure.

[Clinical significance of dystrophin positive fibers in Duchenne muscular dystrophy]

Dystrophin is a protein product of the Xp 21 gene which is defective in patients with Duchenne muscular dystrophy (DMD). In immunohistochemical staining of dystrophin, the majority of DMD muscle fibers show negative staining. Nevertheless, biopsy specimens from DMD patients labeled with many different antibodies may show a small number of fibers which are clearly dystrophin positive. This very small percentage of dystrophin-positive fibers (DPF) probably represents somatic reversion, suppression of the DMD gene mutation or alternating splicing of dystrophin mRNA. To determine the significance of isolated DPF in muscle specimens of DMD patients, we examined 30 DMD muscle specimens, aged 4 years to 16 years, by the use of monoclonal antibody against the C-terminal region of dystrophin. Additionally, muscle specimens from 2 normal human controls and 2 mice with X-linked muscular dystrophy were used for positive and negative controls, respectively. Muscle specimens from DMD patients and mdx mice showed almost totally negative dystrophin staining in most of their muscle fibers, but in 20 patients, three was a trace of isolated DPF ranging from 0.06% to 0.77%. DMD patients with no isolated DPF seemed to have higher functional disability. In the whole group of 30 patients, a significant negative correlation was found between the abundance of DPF and clinical functional grading (r = -0.85, p < 0.0001, based on linear regression). It is suggested that even the very low concentrations of dystrophin found in DMD patients may have a favorable functional significance.

[Study of myoblast culture and myoblast transfer therapy in dystrophic mice]

In this report, we study the suitable conditions for myoblast cultures through analysis of myoblast growth and differentiation, and then try to develop a mouse model for myoblast transfer therapy (MTT). Recently, some research has indicated that Muscular Dystrophy Murine Mice (MDX) have an X-linked recessive dystrophin deficiency which is caused by dystrophin gene point mutation at the X chromosome. Therefore, MDX mice are usually used for MTT models of muscular dystrophy disease. Control mice, C57BL10/SCSN (B-10) were chosen as a source of normal myoblasts. Myoblasts isolated from the hindlimb muscle tissues of two- to three-day-old neonatal B-10 mice were cultured in vitro for one to seven days. Through our modifyied techniques of isolation and culturing conditions, a myoblast purity of 70% could be achieved, with fibroblast the only contaminating cell type. The proliferative capacity and the doubling time of myoblasts were counted from analysis of growth kinetics. While differentiative capacity was analyzed morphologically, we found the fusion of myoblasts was time-dependent. Immunostaining myoblasts of different stages with anti-dystrophin antibody showed that purified myoblasts with the capacity of fusion can express dystrophin and can be utilized as a donating source in MTT. In the MTT experiment, eight young MDX mice were injected with normal myoblasts at a concentration of 1 x 10(6) cells. All transplated mice received daily cyclosporine A injection for immunosuppression. Two to three months later, dystrophin was found in the myoblast-transferred muscles while staining immunocytochemically. The result suggests that we successfully transferred the normal dystrophin gene from the normal myoblasts into the MDX mice since their myoblast-injected muscle could express dystrophin.

Dystrophin immunostaining of muscle from Chinese patients with various neuromuscular diseases

The localization of dystrophin was studied using the immunohistochemical method of diagnostic muscle specimens from 68 patients, aged 9 days to 65 years, with various neuromuscular disorders. Additionally muscle specimens from 2 normal humans and 2 normal mice were used as positive controls, and those from 2 mice with x-linked muscular dystrophy as negative controls. The specimens from all 14 Duchenne muscular dystrophy (DMD) patients, including one with preclinical DMD, showed negative dystrophin staining except for two which had 0.2% to 0.8% positive fibers. The mdx mice also showed negative dystrophin staining. In Becker muscular dystrophy (BMD), muscle fibers stained in a patchy or discontinuous fashion. Two symptomatic DMD carriers exhibited a distinct mosaic pattern of dystrophin positive and negative fibers. In contrast, dystrophin was present in all 7 biopsies from patients with 4 other types of muscular dystrophy (limb-girdle, congenital, myotonic and facioscapulohumeral). Other specimens, those from normal humans and control mice, revealed homogeneous immunostaining along the surface membranes of all muscle fibers. We thus conclude that immunohistochemical dystrophin staining can aid in differentiating DMD from preclinical DMD or BMD, as well as in the detection of DMD carriers.

Highly efficient conversion of picosecond Nd laser pulses with the use of group-velocity-mismatched frequency doubling in KDP

We report an increase in the conversion efficiency from approximately 40% to approximately 75% for type II frequency doubling of 1.053-microm, 1.6-ps-duration pulses in KDP when a delay of approximately 1.45 +/- 0.1 ps between the extraordinary and ordinary pulses is introduced at the input to the doubling crystal. The delay compensates for the effect of group-velocity dispersion in the crystal with the result that the effective interaction length in the crystal is approximately doubled.

Nonresonant chi((3))(1111)obtained by nearly degenerate four-wave mixing using chirped-pulse technology

Picosecond chirped-pulse technology is used to generate two spectrally separate, time-synchronized pulses for chi((3)) measurements by nearly degenerate four-wave mixing. Near 1053 nm, nonresonant relative measurements of chi((3))(1111)are carried out on three model substances, nitrobenzene, alpha chloronaphthalene, and 4'-decyloxynaphthyl-1'-(4-decyloxybenzoate). Their chi((3)) values are normalized to CS(2).

Acute effects of fever, fasting and aspirin on infant rat gastric mucosa

Clinical experience shows that young children with gastrointestinal bleeding have frequently had some preceding febrile illness for which aspirin was administered. Febrile young children often have poor food or liquid intake, or have been in a fasting state because of diarrhea, vomiting or anorexia. The objective of this study was to determine the acute effects of fever, fasting and oral aspirin administration on the gastrointestinal mucosa. One hundred and sixty-eight infant rats, from 21 to 28 days of age and weighting from 70 to 120 g were studied. Random assignment was made to eight groups (Grs): Control (Gr I); aspirin administration only (Gr II); fasting only (Gr III); fever only (Gr IV); aspirin and fever (Gr V); fasting and fever (Gr VI); aspirin and fasting (Gr VII); and aspirin, fever and fasting (Gr VIII). Aspirin was given orally in a single daily dose of 200 mg/kg for two days. Fever was induced by an intraperitoneal injection of 0.6 ml salmonella vaccine. Fasting time lasted from 40 to 48 hours (8 hours prior to the beginning of the experiment to the end of study). The severity of the gastric bleeding was estimated by scoring the number of petechiae and the percentage of the hemorrhagic erosion area from grade 0 to 3. Results showed that rats in Grs VII and VIII had significantly more severe grades of petechiae and hemorrhage than the other groups. These were the groups where the risk factors of fasting and aspirin administration coexisted. In addition to fasting, Gr VIII had fever, but this group did not show more gastric mucosal damage than Gr VII showed.(ABSTRACT TRUNCATED AT 250 WORDS)