Immune checkpoint inhibitor-related colitis in patients on immunotherapy for cancer

OBJECTIVES

Immune checkpoint inhibitors, a revolutionary class of cancer immunotherapy drugs, have transformed cancer treatment by bolstering antitumor immunity for various advanced-stage solid cancers. The US Food and Drug Administration has approved 7 immune checkpoint inhibitors that target 3 major immune checkpoint proteins: cytotoxic T-lymphocyte-associated protein 4, programmed cell death 1 protein, and programmed cell death 1 ligand 1. In addition to their remarkable efficacy, however, these inhibitors have been observed causing immune-related adverse events, particularly immune checkpoint inhibitor-related colitis, which often results in severe or life-threatening clinical issues.

METHODS

The diagnosis of immune checkpoint inhibitor-related colitis relies on incorporation of clinical evaluation as well as endoscopic and histopathologic examination, with exclusion of other potential etiologies.

RESULTS

The common histopathologic manifestations of immune checkpoint inhibitor-related colitis are acute active colitis, chronic active colitis, microscopic colitis (collagenous or lymphocytic), and ischemic colitis, with patterns overlapping. Notably, enterocyte apoptosis is a unique feature of immune checkpoint inhibitor toxicity. The proposed mechanisms for the pathogenesis of immune checkpoint inhibitor-related colitis are primarily associated with autoimmune-type dysregulation and gut microbiome alteration. This review summarizes the clinical and pathologic characteristics of immune checkpoint inhibitor-related colitis and elucidates its underlying pathogenic mechanisms.

CONCLUSIONS

Future successful management of this form of colitis relies on our comprehension of the intricate interplay between tumoral and systemic immune responses to immune checkpoint inhibitors and innovative approaches to modify these responses, along with specific immune cell populations, to preclude immune-related adverse events while achieving antitumor therapeutic outcomes.

Motionless volumetric structured light sheet microscopy

To meet the increasing need for low-cost, compact imaging technology with cellular resolution, we have developed a microLED-based structured light sheet microscope for three-dimensional ex vivo and in vivo imaging of biological tissue in multiple modalities. All the illumination structure is generated directly at the microLED panel-which serves as the source-so light sheet scanning and modulation is completely digital, yielding a system that is simpler and less prone to error than previously reported methods. Volumetric images with optical sectioning are thus achieved in an inexpensive, compact form factor without any moving parts. We demonstrate the unique properties and general applicability of our technique by ex vivo imaging of porcine and murine tissue from the gastrointestinal tract, kidney, and brain.

Involvement of eNAMPT/TLR4 inflammatory signaling in progression of non-alcoholic fatty liver disease, steatohepatitis, and fibrosis

Although the progression of non-alcoholic fatty liver disease (NAFLD) from steatosis to steatohepatitis (NASH) and cirrhosis remains poorly understood, a critical role for dysregulated innate immunity has emerged. We examined the utility of ALT-100, a monoclonal antibody (mAb), in reducing NAFLD severity and progression to NASH/hepatic fibrosis. ALT-100 neutralizes eNAMPT (extracellular nicotinamide phosphoribosyltransferase), a novel damage-associated molecular pattern protein (DAMP) and Toll-like receptor 4 (TLR4) ligand. Histologic and biochemical markers were measured in liver tissues and plasma from human NAFLD subjects and NAFLD mice (streptozotocin/high-fat diet-STZ/HFD, 12 weeks). Human NAFLD subjects (n = 5) exhibited significantly increased NAMPT hepatic expression and significantly elevated plasma levels of eNAMPT, IL-6, Ang-2, and IL-1RA compared to healthy controls, with IL-6 and Ang-2 levels significantly increased in NASH non-survivors. Untreated STZ/HFD-exposed mice displayed significant increases in NAFLD activity scores, liver triglycerides, NAMPT hepatic expression, plasma cytokine levels (eNAMPT, IL-6, and TNFα), and histologic evidence of hepatocyte ballooning and hepatic fibrosis. Mice receiving the eNAMPT-neutralizing ALT-100 mAb (0.4 mg/kg/week, IP, weeks 9 to 12) exhibited marked attenuation of each index of NASH progression/severity. Thus, activation of the eNAMPT/TLR4 inflammatory pathway contributes to NAFLD severity and NASH/hepatic fibrosis. ALT-100 is potentially an effective therapeutic approach to address this unmet NAFLD need.

Targeting SELPLG/P-selectin glycoprotein ligand 1 in preclinical ARDS: Genetic and epigenetic regulation of the SELPLG promoter

We previously identified a missense single nucleotide polymorphism rs2228315 (G>A, Met62Ile) in the selectin-P-ligand gene (SELPLG), encoding P-selectin glycoprotein ligand 1 (PSGL-1), to be associated with increased susceptibility to acute respiratory distress syndrome (ARDS). These earlier studies demonstrated that SELPLG lung tissue expression was increased in mice exposed to lipopolysaccharide (LPS)- and ventilator-induced lung injury (VILI) suggesting that inflammatory and epigenetic factors regulate SELPLG promoter activity and transcription. In this report, we used a novel recombinant tandem PSGL1 immunoglobulin fusion molecule (TSGL-Ig), a competitive inhibitor of PSGL1/P-selectin interactions, to demonstrate significant TSGL-Ig-mediated decreases in SELPLG lung tissue expression as well as highly significant protection from LPS- and VILI-induced lung injury. In vitro studies examined the effects of key ARDS stimuli (LPS, 18% cyclic stretch to simulate VILI) on SELPLG promoter activity and showed LPS-mediated increases in SELPLG promoter activity and identified putative promoter regions associated with increased SELPLG expression. SELPLG promoter activity was strongly regulated by the key hypoxia-inducible transcription factors, HIF-1α, and HIF-2α as well as NRF2. Finally, the transcriptional regulation of SELPLG promoter by ARDS stimuli and the effect of DNA methylation on SELPLG expression in endothelial cell was confirmed. These findings indicate SELPLG transcriptional regulation by clinically-relevant inflammatory factors with the significant TSGL-Ig-mediated attenuation of LPS and VILI highly consistent with PSGL1/P-selectin as therapeutic targets in ARDS.

A Humanized Monoclonal Antibody Targeting Extracellular Nicotinamide Phosphoribosyltransferase Prevents Aggressive Prostate Cancer Progression

Prostate cancer (PCa) is the major cause of cancer-related death in males; however, effective treatments to prevent aggressive progression remain an unmet need. We have previously demonstrated that secreted extracellular nicotinamide phosphoribosyltransferase (eNAMPT) is a multifunctional innate immunity regulator that promotes PCa invasion. In the current study, we further investigate the therapeutic effects of an eNAMPT-neutralizing humanized monoclonal antibody (ALT-100 mAb) in preclinical PCa orthotopic xenograft models. We utilized human aggressive PCa cells (DU145 or PC3) for prostate implantation in SCID mice receiving weekly intraperitoneal injections of either ALT-100 mAb or IgG/PBS (control) for 12 weeks. Prostatic tumors and solid organs were examined for tumor growth, invasion, and metastasis and for biochemical and immunohistochemistry evidence of NFκB activation. ALT-100 mAb treatment significantly improved overall survival of SCID mice implanted with human PCa orthotopic prostate xenografts while inducing tumor necrosis, decreasing PCa proliferation and reducing local invasion and distal metastases. The ALT-100 mAb inhibits NFκB phosphorylation and signaling in PCa cells both in vitro and in vivo. This study demonstrates that eNAMPT neutralization effectively prevents human PCa aggressive progression in preclinical models, indicating its high potential to directly address the unmet need for an effective targeted therapy for patients with aggressive PCa.

Immunotherapy in treatment of metastatic prostate cancer: An approach to circumvent immunosuppressive tumor microenvironment

Prostate cancer is the second most common cause of cancer-related death in men in the United States and the fifth worldwide. Most prostate cancer arises as an androgen-dependent tumor but eventually progresses into castration-resistance prostate cancer, incurable by the current androgen deprivation therapy and chemotherapy. The development of immunotherapy in cancer treatment has brought an exciting era of antiprostate cancer therapy through antitumor immune responses. Prostate cancer is recognized as a poorly immunogenic tissue with immunological ignorance showing low levels of antigen-presenting process and cytotoxic T-cell activation, high levels of immune checkpoint molecules and immunosuppressive cytokines/chemokines, and recruitment of immunosuppressive cells. Immunotherapies for prostate cancer have been developed to activate the innate and adaptive immune responses, such as vaccines and adoptive CAR-T cells, or to inhibit immunosuppressive molecules, such as immune checkpoint inhibitors or antibodies. The U.S Food and Drug Administration has approved Sipuleucel-T for the treatment of asymptomatic or minimally symptomatic metastatic castrate-resistant prostate cancer (mCRPC) and immune checkpoint inhibitor pembrolizumab for the treatment of all solid tumors, including prostate cancer, with impaired mismatch repair genes/microsatellite instability; however, the current clinical outcomes still need to be improved. As various immunosuppressive mechanisms coexist and cross-interact within the tumor microenvironment, different immunotherapy approaches may have to be combined and selected in a highly personalized way. It is hoped that this rapidly evolving field of immunotherapy will achieve successful treatment for mCRPC and will be applied to a wider range of prostate cancer patients.

Submucosal gastric heterotopia presenting as an upper esophageal nodule

Esophageal gastric heterotopia (GH), the presence of differentiated gastric tissue in the esophagus, is estimated in up to 14% of populations worldwide and has always been reported on the surface of the esophagus, where it is also known as inlet patch. However, submucosal GH, in any tissue, is a rare finding. We report the case of a 50 year-old male presenting with chronic cough, heartburn and raspy vocalizations. Endoscopic examination showed a single 7 mm esophageal nodule, 20 cm from the incisors, interpreted as a submucosal mass. Pathologic examination of the endoscopically excised nodule showed well-differentiated gastric mucosa within the submucosa underneath the overlying squamous mucosa, consistent with submucosal GH. This case raises the awareness of an atypical presentation and location of GH seen as a submucosal mass on endoscopy.

Role of secreted extracellular nicotinamide phosphoribosyltransferase (eNAMPT) in prostate cancer progression: Novel biomarker and therapeutic target

BACKGROUND

There remains a serious need to prevent the progression of invasive prostate cancer (PCa). We previously showed that secreted extracellular nicotinamide phosphoribosyltransferase (eNAMPT) is a multifunctional innate immunity regulator via TLR4 ligation which has been implicated in PCa progression. Here we investigate the role of eNAMPT as a diagnostic biomarker and therapeutic target in the progression of PCa.

METHODS

Tumor NAMPT expression and plasma eNAMPT level were evaluated in human subjects with various PCa tumor stages and high risk subjects followed-up clinically for PCa. The genetic regulation of NAMPT expression in PCa cells and the role of eNAMPT in PCa invasion were investigated utilizing in vitro and in vivo models.

FINDINGS

Marked NAMPT expression was detected in human extraprostatic-invasive PCa tissues compared to minimal expression of organ-confined PCa. Plasma eNAMPT levels were significantly elevated in PCa subjects compared to male controls, and significantly greater in subjects with extraprostatic-invasive PCa compared to subjects with organ-confined PCa. Plasma eNAMPT levels showed significant predictive value for diagnosing PCa. NAMPT expression and eNAMPT secretion were highly upregulated in human PCa cells in response to hypoxia-inducible factors and EGF. In vitro cell culture and in vivo preclinical mouse model studies confirmed eNAMPT-mediated enhancement of PCa invasiveness into muscle tissues and dramatic attenuation of PCa invasion by weekly treatment with an eNAMPT-neutralizing polyclonal antibody.

INTERPRETATION

This study suggests that eNAMPT is a potential biomarker for PCa, especially invasive PCa. Neutralization of eNAMPT may be an effective therapeutic approach to prevent PCa invasion and progression.

Current Microsatellite Instability Testing in Management of Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer worldwide. In the past decade, mismatch repair deficiency (dMMR), manifested as microsatellite instability-high (MSI-H), has been recognized as a distinct mechanism promoting tumorigenesis in 15% of CRCs including 3% Lynch syndrome and 12% sporadic CRCs. As the molecular classifications of CRCs are continuously evolving, MSI-H CRCs appear to be the most homogeneous CRCs with distinct molecular, morphologic, and clinical features. MSI-H CRCs have dMMR causing MSI-H and genetic hypermutation but with diploid chromosomes. Morphologically, MSI-H CRCs appear as poorly differentiated or mucinous adenocarcinoma with characteristic lymphocytic infiltration. Most importantly, MSI-H CRCs have better stage-adjusted survival, do not respond well to standard 5-fluorouracil-based adjuvant chemotherapy, but do respond to immunotherapy. The United States Food and Drug Administration granted accelerated approval to immune checkpoint inhibitors, anti-programmed cell death protein-1 antibodies pembrolizumab and nivolumab, and the combination of nivolumab with anti-CTLA4 antibody ipilimumab for the second-line treatment of patients with stage IV MSI-H CRCs in 2017. There are still ongoing phase III clinical trials evaluating pembrolizumab and anti-programmed death-ligand 1 antibody atezolizumab as the first-line treatment in stage IV MSI-H CRCs and a phase I study on the combination of nivolumab and ipilimumab in patients with early stage CRC. These ongoing clinical studies on immunotherapy may lead to practice-changing results in the management of MSI-H CRCs. The National Comprehensive Cancer Network 2018 guidelines recommended MSI to be tested in all newly diagnosed CRCs. The MSI test will become increasingly vital in guiding adjuvant chemotherapy and immunotherapy in the management of CRCs.

Direct Extracellular NAMPT Involvement in Pulmonary Hypertension and Vascular Remodeling. Transcriptional Regulation by SOX and HIF-2α

We previously demonstrated involvement of NAMPT (nicotinamide phosphoribosyltransferase) in pulmonary arterial hypertension (PAH) and now examine NAMPT regulation and extracellular NAMPT's (eNAMPT's) role in PAH vascular remodeling. NAMPT transcription and protein expression in human lung endothelial cells were assessed in response to PAH-relevant stimuli (PDGF [platelet-derived growth factor], VEGF [vascular endothelial growth factor], TGF-β1 [transforming growth factor-β1], and hypoxia). Endothelial-to-mesenchymal transition was detected by SNAI1 (snail family transcriptional repressor 1) and PECAM1 (platelet endothelial cell adhesion molecule 1) immunofluorescence. An eNAMPT-neutralizing polyclonal antibody was tested in a PAH model of monocrotaline challenge in rats. Plasma eNAMPT concentrations, significantly increased in patients with idiopathic pulmonary arterial hypertension, were highly correlated with indices of PAH severity. eNAMPT increased endothelial-to-mesenchymal transition, and each PAH stimulus significantly increased endothelial cell NAMPT promoter activity involving transcription factors STAT5 (signal transducer and activator of transcription 5), SOX18 (SRY-box transcription factor 18), and SOX17 (SRY-box transcription factor 17), a PAH candidate gene newly defined by genome-wide association study. The hypoxia-induced transcription factor HIF-2α (hypoxia-inducible factor-2α) also potently regulated NAMPT promoter activity, and HIF-2α binding sites were identified between -628 bp and -328 bp. The PHD2 (prolyl hydroxylase domain-containing protein 2) inhibitor FG-4592 significantly increased NAMPT promoter activity and protein expression in an HIF-2α-dependent manner. Finally, the eNAMPT-neutralizing polyclonal antibody significantly reduced monocrotaline-induced vascular remodeling, PAH hemodynamic alterations, and NF-κB activation. eNAMPT is a novel and attractive therapeutic target essential to PAH vascular remodeling.

Graft-Versus-Host Disease With Early Cytomegalovirus Infection in Gastrointestinal Tract Biopsies

Gastrointestinal (GI) graft-versus-host disease (GVHD) and cytomegalovirus (CMV) infection often simulate each other. However, distinction between GVHD and CMV infection is critical in the management of immunosuppression for transplant recipients. This study retrospectively reviewed 16 patients diagnosed with GVHD from 2010 to 2016 and found 4 cases (25%) coinfected with CMV. Two cases were initially diagnosed as GVHD only but found to have CMV infection by serological testing within 3 days after immunosuppression treatment for GVHD. The remarkable histological feature of CMV infection appeared to be significant acute inflammation in addition to apoptotic epithelial injuries, and particularly in an early stage of CMV replication, acute inflammation is possibly the only detectable feature of CMV infection.

Effects of Moringa oleifera silage on milk yield, nutrient digestibility and serum biochemical indexes of lactating dairy cows

This study investigated the effects of Moringa oleifera (MO) as a partial substitute of alfalfa hay on milk yield, nutrient apparent digestibility and serum biochemical indexes of dairy cows. MO was harvested at 120 days post-seeding. Fresh MO was cut, mixed with chopped oat hay (425:575 on a DM basis), ensiled and stored for 60 days. Sixty healthy Holstein dairy cows were allocated to one of three groups: NM (no MO or control), LM (low MO; 25% alfalfa hay and 50% maize silage were replaced by MO silage) or HM (high MO; 50% alfalfa hay and 100% maize silage were replaced by MO silage). The feeding trial lasted 35 days. The LM and HM diets did not affect dry matter (DM) intake, milk yield or milk composition (lactose, milk fat, milk protein and somatic cell count). The apparent digestibility of DM and NDF was lower for HM group than NM group. Additionally, there were no significant differences in serum biochemical indexes between the LM and NM groups. The HM group had lower serum concentrations of total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol and higher serum concentrations of urea than the NM group. The partial replacement of alfalfa hay (≤50%) and maize silage with MO silage had no negative effects on milk yield, in vivo nutrient apparent digestibility or serum biochemical indexes of lactating cows.

[Application of (125)I seeds combined with biliary stent implantation in the treatment of malignant obstructive jaundice]

OBJECTIVE

To study the feasibility and therapeutic effect of the application of (125)I seeds combined with biliary stent implantation on the treatment of malignant obstructive jaundice.

METHODS

Fifty patients with malignant obstructive jaundice treated from September 2010 to February 2013 in Yantai Yuhuangding Hospital were included in this study. Among them, 24 patients received biliary stent implantation combined with (125)I seeds intraluminal brachytherapy as experimental group, and 26 were treated by biliary stent implantation as control group.The total bilirubin, direct bilirubin and tumor markers (CA-199, CA-242, CEA) before and after surgery, the biliary stent patency status was assessed, and the survival time was evaluated.

RESULTS

The 24 patients in experimental group were implanted with 30 (125)I seeds successfully in a total of 450 seeds. Jaundice was improved greatly in both groups. The CA-199 and CA-242 after treatment in the experimental group were significantly decreased than that before treatment (P=0.003 and P=0.004). CEA was also decreased, but showed no statistical significance (P>0.05). There were no significant improvement comparing the CA-199, CA-242 and CEA before and 2 months after surgery in the control group (P>0.05). The rate of biliary stent patency was 83.3% (20/24) in the experimental group and 57.7% (15/26) in the control group (P=0.048). The mean biliary stent patency time in the experimental group was 9.84 months (range 1-15.5 months). The mean biliary stent patency time in the control group was 5.57 months (range 0.8-9 months). There was a significant difference between the two groups (P=0.018). The median survival time was 10.2 months in the experimental group and 5.4 months in the control group (P<0.05).

CONCLUSION

(125)I seeds combined with biliary stent implantation can inhibit the proliferation of vascular endothelial cells and the growth of tumor effectively, and can prolong the biliary stent patency time and the survival time obviously for patients with malignant obstructive jaundice, therefore, is a safe and effective treatment in this malignancy.

Cystic Nephroma/Mixed Epithelial Stromal Tumor

Cystic nephroma (CN) is a rare, benign, renal neoplasm composed of epithelial and stromal elements. Only about 200 cases have been reported since 1892 and recurrence has rarely been observed. We report a 32-year-old Hispanic woman, with a history of a right, complex cystic, renal mass treated by robotic decortication 2 years ago, who presented with flank pain, hematuria, and recurrent urinary tract infection. A magnetic resonance imaging study showed a 3.4-cm multicystic lesion with thickened septa and enhancement at the right kidney. The partial nephrectomy specimen revealed a well-circumscribed, multicystic tumor abutting the renal pelvis, with thick septa and smooth walls, filled with clear fluid. Microscopic examination showed variably sized cysts lined by cuboidal epithelium with focal hobnailing, without significant cytologic atypia and mitosis. The epithelial lining was positive for CK19, high molecular weight cytokeratin, and α-methylacyl-CoA racemase suggesting a primitive tubular epithelial phenotype. Primitive glomeruli-like structures were also present. The ovarian-like stroma was condensed around the cysts and was variably cellular with areas of muscle differentiation and thick-walled vessels. The stroma was positive for desmin, estrogen receptor, progesterone receptor, and CD10. We suggest that CN represents a variable mixture of epithelial and stromal elements, immature glomerular, tubular, muscle, and vascular elements, which may be present in variable proportions creating a spectrum of lesions previously described as CN and mixed epithelial and stromal tumors (MEST). This case emphasizes that CN/MEST clinically/radiologically mimics other cystic renal neoplasms, especially cystic renal cell carcinoma and tubulocystic carcinoma, necessitating histopathological examination and immunohistochemial studies for definitive diagnosis. Additionally, CN has the tendency to recur when not completely excised initially.

Metachronous bilateral testicular seminoma developing after an interval of 31 years: case report and review of the literature

Men diagnosed with testicular germ cell tumors are at higher risk for development of a second germ cell tumor in the contralateral testis. Metachronous bilateral testicular germ cell tumors usually occur within 5 years. Here, we report a case of a 63-year-old man previously diagnosed with testicular seminoma and treated with a left orchiectomy followed by radiation, developing contralateral testicular seminoma after an interval of 31 years. The patient was asymptomatic and found to have an enlarged, nontender right testis on routine urological examination. Further workup did not reveal evidence of metastatic disease or lymphadenopathy. The surgery specimen revealed a 4.2 × 3.1 × 1.8 cm distinct mass without tumor involvement of tunica albuginea or the tunica vaginalis. Microscopy showed classic seminoma with venous/lymphatic tumor invasion. The current case underscores the importance of recommending lifelong follow-up for patients with testicular germ cell tumors.

Single nucleotide polymorphism variants within tva and tvb receptor genes in Chinese chickens

Avian leukosis is an immunosuppressive neoplastic disease caused by avian leukosis viruses (ALV), which causes tremendous economic losses in the worldwide poultry industry. The susceptibility or resistance of chicken cells to subgroup A ALV and subgroup B, D, and E ALV are determined by the receptor genes tumor virus locus A (tva) and tumor virus locus B (tvb), respectively. Four genetic resistant loci (tva(r1), tva(r2), tva(r3), and tva(r4)) in tva receptor gene and a genetic resistant locus tvb(r) in the tvb receptor gene have been identified in inbred lines of White Leghorn. To evaluate the genetic resistance to subgroup A, B, D, and E ALV, genetic variations within resistant loci in tva and tvb genes were screened in Chinese local chicken breeds and commercial broiler lines. Here, the heterozygote tva(s1/r1) and the resistant genotype tva(r2/r2), tva(r3/r3), and tva(r4/r4) were detected in Chinese chickens by direct sequencing. The heterozygote tva(s1/r1) was detected in Huiyang Bearded chicken (HYBC), Rizhaoma chicken, and commercial broiler line 13 to 15 (CB13 to CB15), with the frequencies at 0.08, 0.18, 0.17, 0.25, and 0.15, respectively. The resistant genotype tva(r2/r2) was detected in Jiningbairi chicken (JNBRC), HYBC, and CB15, with the frequencies at 0.03, 0.08, and 0.06, respectively, whereas tva(r3/r3) and tva(r4/r4) were detected in 19 and 17 of the 25 Chinese chickens tested, with the average frequencies at 0.13 and 0.20, respectively. Furthermore, the resistant genotype tvb(r/r) was detected in JNBRC, CB07, CB12, CB14, and CB15 by pyrosequencing assay, with the frequencies at 0.03, 0.03, 0.11, 0.09, and 0.15, respectively. These results demonstrated that the potential for genetic improvement of resistance to subgroup A, B, D, and E ALV were great both in Chinese local chickens and commercial broilers. This study provides valuable insight into the selective breeding for chickens genetically resistant to ALV.

Effects of Ginkgo biloba extract on somatosensory evoked potential, nitric oxide levels in serum and brain tissue in rats with cerebral vasospasm after subarachnoid hemorrhage

This study aimed to investigate the protective effects of Ginkgo biloba extract on cerebral vasospasm and neural damage following subarachnoid hemorrhage (SAH) in rats. It was found that the regional cerebral blood flow decreased immediately and persistently after SAH in SAH rats. The latency of somatosensory evoked potential delayed progressively. The nitric oxide levels in serum and brain tissue decreased and increased, respectively, after SAH. Ginkgo biloba extract effectively antagonized the changes of above parameters. It was concluded that somatosensory evoked potential is useful for the judgement of cerebral ischemic damage during cerebral vasospasm after SAH. Decrease in serum nitric oxide and increase in brain tissue nitric oxide are important factors leading to cerebral vasospasm and neural damage, respectively, after SAH. Ginkgo biloba extract relieves cerebral vasospasm and cerebral ischemic damage by reversing the pathological alteration of nitric oxide.

Effects of blockade of cerebral lymphatic drainage on cerebral ischemia after middle cerebral artery occlusion in rats

This experiment aimed to investigate the effects of blockade of cerebral lymphatic drainage on cerebral ischemic damage. Seventy six Wistar rats were divided randomly into middle cerebral artery occlusion (MCAO) group and MCAO plus cerebral lymphatic blockade (MCAO+CLB) group for the experiment. The contents of water and electrolytes, the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) in the ischemic brain tissue were detected at 24, 48 and 72 hours after the operation. The morphologic examination was also performed. In MCAO group, contents of water, sodium and calcium in the ischemic brain tissue increased significantly at any time after the operation. The SOD activity decreased while the MDA content increased markedly. The morphologic findings showed severe damage of ischemic brain tissue and neurons. In MCAO+CLB group, the above parameters were altered more obviously. The present observation suggests that blockade of cerebral lymphatic drainage may deteriorate ischemic brain damage after MCAO.

[Changes of nitric oxide and endothelin-1 levels in rat brain tissue during cerebral vasospasm following subarachnoid hemorrhage and protective effect of nimodipine]

AIM

To investigate the changes of nitric oxide and endothelin-1 levels in brain tissue in rat with cerebral vasospasm (CVS) following subarachnoid hemorrhage (SAH), and the protective effect of nimodipine.

METHODS

Wistar rats were divided randomly into SAH group, nimodipine-treated group and sham-operated group. Diameters of basilar artery before and after operation were measured, and dynamic changes of regional cerebral blood flow (rCBF), brain nitric oxide and endothelin-1 levels were determined within 24 h. Pathological examination of hippocampus was also performed.

RESULTS

SAH resulted in significant and persistent decrease of rCBF. Diameter of basilar artery was reduced markedly. Neurons in hippocampus CA1 subfield were damaged severely. Both nitric oxide and endothelin-1 levels in brain tissue were increased significantly from 1 h to 24 h after SAH. However, the pathological changes of above parameters were not so severe in nimodipine-treated rats.

CONCLUSION

Increase of nitric oxide and endothelin-1 levels in brain tissue is probably involved in the development of ischemic brain damage caused by CVS after SAH. Nimodipine exerts its protective effect on brain neurons by antagonizing CVS and the pathological changes of nitric oxide and endothelin-1 in brain tissue.

[Effects of ginkgo biloba extract on somatosensory evoked potential and nitric oxide after subarachnoid hemorrhage]

OBJECTIVE

To observe the changes of somatosensory evoked potential(SEP) and nitric oxide (NO) after subarachnoid hemorrhage(SAH), and the influence of Ginkgo biloba extract (EGb).

METHOD

Rats in sham-operated group, SAH model group and EGb-treated group underwent measurement of dynamic changes of regional cerebral blood flow(rCBF), SEP and NO levels both in serum and in brain tissue within 24 h after operation.

RESULT

In SAH group, rCBF decreased immediately after operation, with no tendency to recover within 24 h. The latency of SEP delayed progressively from 1 h to 24 h after SAH. NO levels in serum and in brain tissue decreased and increased respectively from 1 h to 24 h after SAH. EGb effectively antagonized the changes of above parameters.

CONCLUSION

SEP is helpful in the judgement on brain ischemic damage after SAH. Decrease of NO in serum and increase of that in brain tissue may lead to cerebral vasospasm and ischemic brain damage respectively after SAH. EGb relieves SAH-induced brain ischemic damage by reversing the pathological alterations of NO.

Ancient and recent patterns of geographic speciation in the oyster mushroom Pleurotus revealed by phylogenetic analysis of ribosomal DNA sequences

Evidence from molecular systematic studies suggests that many mushroom species may be quite ancient. Gene phylogenies were developed to examine the relationship between reproductive isolation, genetic divergence, and biogeography in oyster mushrooms (Pleurotus). Sequence data were obtained for two regions of DNA from populations belonging to eight intersterility groups (biological species). Phylogenetic analysis of sequences from the 5' portion of the nuclear encoded large subunit rDNA demonstrates an ancient origin for four intersterility groups of broad geographic distribution (world-wide), with a more recent radiation of several intersterility groups that are restricted to the Northern Hemisphere. An expanded analysis using sequence data from the more variable rDNA internal transcribed spacer region also reveals a phylogenetically based pattern of genetic divergence associated with allopatric speciation among populations from different continents in the Northern Hemisphere. The ability of rDNA sequences to resolve phylogenetic relationships among geographically isolated populations within intersterility groups illustrates the importance of biogeography for understanding speciation in Pleurotus. Patterns of geographic distribution among intersterility groups suggest that several species lineages evolved quite early, with recently evolved groups restricted to the Northern Hemisphere and older lineages occurring throughout the world. Based on phylogenetic evidence, analysis of historical biogeography using area cladograms shows that multiple dispersal and vicariance events are responsible for patterns of speciation observed.

[Clinical analysis and percutaneous transhepatic cholangiography drainage treatment of 25 patients with clonorciosis]

The clinical data of 25 patients with clonorchiasis were analyzed. Some features shown by B-mode ultrasonography and percutaneous transhepatic cholangiography (PTC) were discussed. Application of percutaneous transhepatic cholangiography drainage (PTCD) for treatment of complete biliary tract obstruction caused by clonorchiasis was introduced.

Comparison of the clinical performance, contraceptive efficacy and acceptability of levonorgestrel-releasing IUD and Norplant-2 implants in China

The levonorgestrel-releasing IUD (LNG-IUD, 20 micrograms/d) and the Norplant-2 implants were studied in a randomized comparative clinical trial with 200 women for one year. No pregnancy or expulsion occurred with the Norplant-2. In the LNG-IUD group, there was one pregnancy at the 12th month of use after an unnoticed expulsion. The net cumulative pregnancy and expulsion rates of LNG-IUD were 1.0 and 3.0. The removal rate due to menstrual disturbances in both LNG-IUD and Norplant-2 groups was 3.0. The use-related discontinuation rates were 9.0 and 3.0, and the continuation rates were 90.0 and 96.0, respectively. The differences were not statistically significant. Menstrual disturbance was the main side effect. It was improved after long time use, especially in the LNG-IUD group. After one year, the percentages of women with amenorrhea were 18.9 for the LNG-IUD and 8.3 for the Norplant-2. The menstrual blood loss was statistically significantly reduced in the LNG-IUD group, and blood haemoglobin concentration increased in both groups. The LNG-IUD and Norplant-2 are highly effective, safe, long-acting, and well accepted by the Chinese women.

Menstrual blood loss and hematologic indices in healthy Chinese women

Menstrual blood loss, cyanmethemoglobin and serum ferritin were determined in 421 healthy, noncontracepting Chinese women. The range of menstrual blood loss (MBL) was 4.1-273.6 mL, the mean value was 54.2 mL, and the median was 42.9 mL. The range of hemoglobin was 8.3-16.7 g/dL, and the mean value was 13.2 g/dL. The range of ferritin was 1.2-180.0 ng/mL, the mean value was 22.8 ng/mL, and the geometric mean was 17.1 ng/mL. The upper normal limit of MBL in Chinese women was set at 80 mL.

Menstrual blood loss, haemoglobin and ferritin concentration of Beijing women wearing steel ring, VCu 200, and TCu 220c IUDs

Menstrual blood loss (MBL), serum ferritin and whole blood cyanmethemoglobin were measured at pre- and 1, 3, 6, 12, 18 and 24th postinsertion cycles in 60 women wearing the Steel Ring, the Copper V (VCu 200) or the Copper T (TCu 220c). The MBL, incidence of menorrhagia and iron deficiency anemia were lower among users of the Steel Ring than among users of the Copper V and T. Anemia occurred later and the duration of menstruation was shorter with the Steel Ring than with the Copper T. There were no statistically significant differences between the Copper V and T.