A223 UNMASKED OR INDUCED COLITIS: COULD IT BE SECUKINUMAB?

Background

Spondyloarthropathies (SpA), such as Ankylosing Spondylitis (AS) are inflammatory disorders which have coheritability with inflammatory bowel disease (IBD). Secukinumab is a monoclonal antibody inhibitor of IL-17A used to treat SpA, but has also been reported to cause de novo and exacerbations of known IBD. Rare reports of Secukinumab induced microscopic colitis have also been documented.

Purpose

To present and discuss the diagnostic challenges in a case of undifferentiated colitis in a patient with AS treated with Secukinumab.

Method

Case report and literature review.

Result(s)

Case Report: A 62-year-old male with a history of AS was admitted to hospital with acute on chronic diarrhea. The patient’s AS was unresponsive to Infliximab, Methotrexate, and Adalimumab, although the latter improved his diarrhea at the time.

A Colonoscopy completed 14 years earlier for chronic diarrhea was endoscopically normal with biopsies of the left colon notable for mild patchy inflammation and fibrosis. A subsequent Colonoscopy with random biopsies 8 years later showed normal mucosa while he was treated with Adalimumab.

He was started on Secukinumab 4 months prior to hospitalization noting progressive watery diarrhea and weight loss of 15kg. Investigations were notable for microcytic anemia (Hemoglobin 120 g/L, MCV 78 fL), elevated CRP (33 mg/L), and a creatinine of 508 µmol/L. Negative tTg antibodies and normal IgA levels ruled out celiac disease. Stool studies were unremarkable. Colonoscopy showed several linear ulcerations in the descending colon and rectum with a normal terminal ileum, transverse, and ascending colon. Biopsies from the endoscopically normal mucosa showed thickened subepithelial collagen band suggestive of microscopic colitis while the ulcerated regions showed cryptic rupture with associated granuloma representing possible Crohn’s colitis versus drug-induced injury. Stains were negative for CMV.

Secukinumab was stopped and he was started on Budesonide with significant improvement in symptoms.

Literature Review

Almost half of all patients with SpA have microscopic intestinal inflammation and of these, 7% eventually develop IBD. Shorter symptom duration, higher SpA activity and male sex are known risk factors for underlying intestinal involvement. However, the exact role of microscopic intestinal inflammation in SpA has yet to be determined.

Secukinumab is an inhibitor of IL-17A with significant efficacy in the treatment of SpA but has been associated with exacerbations of Crohn’s disease and de novo cases of IBD. Thus, the role of IL-17 in IBD remains uncertain and may suggest a protective effect rather than an inflammatory one seen in SpA. The long half-life of Secukinumab (24-31 days) presents challenges when considering treatment with other biologics, such as anti-TNFs, which may cause excessive immunosuppression.

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Conclusion(s)

New onset colitis is a described but rare entity in patients treated with Secukinumab presenting several diagnostic and treatment challenges.

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Disclosure of Interest

None Declared

A137 AN ELUSIVE GASTROINTESTINAL BLEED: A CASE OF RUPTURED CYSTIC ARTERY PSEUDOANEURYSM WITH PREVIOUS BILLROTH-II SURGERY

Background

Cystic artery pseudoaneurysm (CAP) is a rare but potentially life-threatening cause of upper gastrointestinal (GI) bleeding and requires urgent intervention.

Aims

To describe the clinical enigma of CAP in the context of distorted anatomy and discuss management.

Methods

Case report and review of literature

Results

Case Report

A healthy 91-year-old man with a remote history of gastric ulcer perforation leading to Billroth-II surgery 40 years ago presented to a community hospital with melena. He had no abdominal pain and liver enzymes were normal. His hemoglobin was 97 g/L (from 137 g/L the month prior) with a BUN:Cr ratio of 50.6 mg/dL and white cell count of 14.4 x109/L. Upper endoscopy identified a large adherent clot in the stomach that could not be dislodged and was suspected to obscure the culprit lesion. Afferent and efferent limbs from previous Billroth-II surgery were identified but not intubated. He was managed supportively with acid suppression and blood transfusion, but his hemoglobin continued decreasing, leading to transfer to a tertiary centre. Upon arrival he had new-onset abdominal pain, rigors, and diaphoresis with a heart rate of 175 beats/minute and blood pressure of 75/40 mmHg. After resuscitation, emergent CT angiogram demonstrated acute contrast extravasation into the gallbladder in keeping with a ruptured CAP. He underwent successful coiling of the cystic artery. Following this, his abdominal pain resolved, and hemoglobin stabilized. Repeat endoscopy demonstrated Billroth-II anatomy without bleeding lesion. He was treated with antibiotics for presumed cholecystitis and discharged home for outpatient cholecystectomy.

Literature Review

CAP is a rare cause of hemobilia, described only in case reports. The complete hemobilia triad of jaundice, right upper quadrant pain, and GI bleeding is absent in the majority of cases, requiring endoscopic evaluation of the ampulla of Vater or contrast CT. The most common causes of CAP are iatrogenic from cholecystectomy, cholecystitis, gallstones, and malignancy. These mechanisms, whether through trauma or inflammation, lead to damage of the gallbladder wall and the cystic artery. Contained CAP can lead to intermittent bleeding whereas ruptured CAP causes brisk arterial bleeding, necessitating arterial embolization or emergent cholecystectomy. In cases of biliary obstruction, either from the original process or subsequent blood clot at the ampulla, ERCP can lead to successful decompression.

Conclusions

We present a case of ruptured CAP which eluded diagnosis due to diagnostic rarity, lack of clinical clues, and distorted anatomy. CAP should be considered with a history of recent cholecystectomy, acute cholecystitis, or gallstones. Maintaining an index of suspicion for rare causes of GI bleeding can ensure timely diagnosis and escalation to the appropriate level of care.

Funding Agencies

None

A85 LIKELIHOOD OF ENDOSCOPY CANCELLATION BASED ON VANCOMYCIN-RESISTANT ENTEROCOCCI (VRE) COLONIZATION STATUS AND INFECTION CONTROL PRACTICES

Background

“Terminal cleaning” is a practice of rigorous cleaning of endoscopy suite following endoscopies for patients colonized with vancomycin-resistant enterocci (VRE) with the intention of reducing VRE transmission. Such practice entails double-wiping all surfaces including the floor with disinfectants before a non-VRE patient can use the endoscopy room. While intuitive, such time-consuming practice is not supported by evidence and may have unintended negative impact on patient access to timely endoscopic evaluation.

Aims

To determine whether terminal cleaning of endoscopy suite for VRE-colonized patients has any negative impact on inpatient access to timely endoscopic evaluation.

Methods

As part of a quality improvement study, inpatient endoscopy data was gathered over a 3-month period between February 2021 and April 2021 at a tertiary centre. EUS, ERCP, and travel cases outside of the endoscopy suite were excluded. The cancellation rates were compared between VRE-colonized patients and non-VRE patients using the Fisher’s exact test. P value of <0.05 was considered statistically significant.

Results

A total of 262 inpatient endoscopic procedures were scheduled and included in the study. Sixty-six (25.2%) of inpatient procedures were cancelled during this period (Table 1). A total of 24 procedures were scheduled for VRE patients, 9 of which were cancelled because of insufficient operating time and two due to concurrent carbapenamase-producing organism carriage and poor bowel preparation. In the non-VRE group, 55 (23.3%) procedures were cancelled for various reasons (Table 1). In subgroup analysis where cancellations related to COVID-19 (n=14) were omitted, VRE patients had a significantly higher rate of procedure cancellations compared to non-VRE patients (42.3% vs. 18.5%; p<0.01).

Conclusions

The overall endoscopy cancellation rate for VRE-colonized patients was higher than those who were non-VRE-colonized. We propose that this is likely secondary to the delays from unnecessary terminal cleans imposed for VRE-colonized patients and await for post-intervention data.

Funding Agencies

None

A276 TOTAL PANCREATIC LIPOMATOSIS AND EXOCRINE PANCREATIC INSUFFICIENCY IN A PATIENT WITH CELIAC DISEASE: AN UNUSUAL ENTITY

Background

Exocrine pancreatic insufficiency (EPI) is characterized by maldigestion and malabsorption of nutrients and is most commonly caused by diseases of the pancreatic parenchyma including chronic pancreatitis and cystic fibrosis (CF). However, EPI is also observed in other conditions including celiac disease (CD).

Aims

We report a case of EPI in a patient with CD found to have total fatty replacement of the pancreas.

Methods

A case report and review of the literature were performed.

Results

Case Report:

A 42-year-old man with CD on gluten-free diet (GFD) presented with a two-year history of increasing bowel frequency (4–6 times daily) and steatorrhea. Quantitative fecal fat over 72 hours confirmed fecal fat excretion of 101g/day; N &lt; 7g) and total stool weight of 3761g. Nadir weight was 67.6 kg. There was a dramatic response to pancreatic enzyme replacement therapy (PERT) with marked improvement in bowel habits and weight gain to 74.8 kg over half a year. There is no history of pancreatitis, abdominal pain or alcohol abuse. He does not smoke but drinks 1–2 units of alcohol per week at most. Family history is negative for pancreatitis and pancreatic malignancy. On examination, following PERT, the patient appeared well-developed and nourished. He did not have clinical features or biochemical evidence of fat-soluble vitamin deficiency following PERT.

Anti-tTG was equivocal (7.6 U/mL; N &lt; 7 U/mL). IgG subclasses were normal. Chromogranin was mildly elevated (100mcg/L; N &lt; 94mcg/L), but gastrin (15ng/L) and 24-hour urine for 5-hydroxyindoleacetate [5-HIAA] (23umol/d) were normal. Endoscopic evaluations including upper endoscopy, colonoscopy, and capsule endoscopy demonstrated intact duodenal villous architecture without inflammation, no microscopic colitis, and no small bowel mucosal disease, respectively.

CT of the abdomen revealed total fatty replacement of the pancreas with no pancreatic parenchyma (Figure 1). Sweat sodium test was positive (67 mmol/L, N &lt; 60 mmol/L) but CFTR gene sequencing was negative. There was no evidence of diabetes, hyperlipidemia, hyperferritinemia, Cushing’s syndrome, or hepatic disease on biochemical investigations.

Literature Review:

Total pancreatic lipomatosis (TPL), or fatty replacement of the pancreas, is a rare cause of EPI which leads to maldigestion, malabsorption, and malnutrition. The pathogenesis of TPL is poorly understood but predisposing factors include obesity, diabetes mellitus, hyperlipidemia, malnutrition, Cushing’s syndrome, hemochromatosis, chronic pancreatitis and CF. EPI can also manifest in patients with CD due to active small bowel inflammation or chronic pancreatitis. Last but not least, there appears to be higher prevalence of CD in CF patients.

Conclusions

Persistent steatorrhea with weight loss despite GFD in patients with CD should prompt other considerations of EPI and trial of PERT.

Funding Agencies

None

A174 RARE BUT DEADLY: AN APPROACH TO MANAGEMENT OF DUODENAL VARICEAL HEMORRHAGE

Background

Common etiologies of upper gastrointestinal bleeding (UGIB) in cirrhotic patients with portal hypertension include gastroesophageal varices (GOV), portal hypertensive gastropathy (PHG) and gastric antral vascular ectasia (GAVE). Less commonly, patients with portal hypertension develop varices in ectopic sites, including the rectum, biliary tree and duodenum. Ectopic varices are rare, contributing to 1–5% of all variceal bleeding, of which 17% is from duodenal varices.

Aims

To describe the management of duodenal variceal hemorrhage.

Methods

A case report and literature review was performed.

Results

Case report:

We present a case of recurrent UGIB in a 59-year-old male with decompensated cirrhosis due to non-alcoholic steatohepatitis (CP-C; Meld 14). Initial endoscopy was negative for GOV, peptic ulcer, PHG, and GAVE, but an erosion over a mucosal bulge in the third segment of the duodenum was identified, raising possibility of vascular malformation versus ectopic varix. There was active bleeding after water provocation, so clips were deployed for hemostasis. CT imaging showed mesenteric venous collaterals abutting the duodenum, again raising possibility of duodenal varix, which was ultimately confirmed by endoscopic ultrasound (EUS). Patient had recurrent overt bleeding despite beta-blockage for prophylaxis, endoscopic clipping on four separate occasions, attempted angioembolization by interventional radiology, and cyanoacrylate glue. Transjugular intrahepatic porto-systemic shunt (TIPS) was not possible due to portal vein occlusion, so he underwent EUS-guided cyanoacrylate glue a second time.

Literature review:

Ectopic varices are rare, contributing to 1–5% of all variceal bleeding, of which 17% is from duodenal varices. Duodenal variceal hemorrhage can lead to hemorrhagic shock, and is potentially life threatening, with quoted mortality rates of 40%. Unfortunately, duodenal varices can be difficult to identify. Diagnosis is often delayed due to a combination of lower awareness and endoscopic challenges given the unusual serosal and submucosal location.

Evidence-based guidelines for the management of ectopic varices are limited. For this reason, our current management strategies rely heavily on local expertise. Splanchnic vasoconstrictor medication, endoscopic ligation, EUS guided gluing, interventional radiology guided embolization, TIPS, balloon retrograde transvenous obliteration and surgical shunts are potential therapeutic options to manage the acutely bleeding varix. Following a variceal bleed, liver transplantation should be considered in eligible patients with no other contraindications.

Conclusions

Duodenal varices are a rare, potentially fatal, and underrecognized cause of gastrointestinal bleeding in patients with portal hypertension. Definitive therapy currently relies upon local expertise in the absence of clear guideline-based therapy.

Funding Agencies

None

Polydopamine deposition with anodic oxidation for better connective tissue attachment to transmucosal implants

BACKGROUND AND OBJECTIVE

Nowadays, most designs for the transmucosal surface of implants are machined-smooth. However, connective tissue adhered to the smooth surface of an implant has poor mechanical resistance, which can render separation of tissue from the implant interface and induce epithelial downgrowth. Modification of the transmucosal surface of implants, which can help form a good seal of connective tissue, is therefore desired. We hypothesized that anodic oxidation (AO) and polydopamine (PD) deposition could be used to enhance the attachment between an implant and peri-implant connective tissue. We tested this hypothesis in the mandibles of Beagle dogs.

MATERIAL AND METHODS

AO and PD were used to modify the transmucosal region of transmucosal implants (implant neck). The surface microstructure, surface roughness and elemental composition were investigated in vitro. L929 mouse fibroblasts were cultured to test the effect of PD on cell adhesion. Six Beagle dogs were used for the in vivo experiment (n = 6 dogs per group). Three months after building the edentulous animal model, four groups of implants (control, AO, PD and AO + PD) were inserted. After 4 months of healing, samples were harvested for histometric analyses.

RESULTS

The surfaces of anodized implant necks were overlaid with densely distributed pores, 2-7 μm in size. On the PD-modified surfaces, N1s, the chemical bond of nitrogen in PD, was detected using X-ray photoelectron spectroscopy. L929 developed pseudopods more quickly on the PD-modified surfaces than on the surfaces of the control group. The in vivo experiment showed a longer connective tissue seal and a more coronally located peri-implant soft-tissue attachment in the AO + PD group than in the control group (P < .05).

CONCLUSION

The modification of AO + PD on the implant neck yielded better attachment between the implant and peri-implant connective tissue.

α5β1-Integrin promotes tension-dependent mammary epithelial cell invasion by engaging the fibronectin synergy site

Fibronectin-ligated α5β1 integrin promotes malignancy by inducing tissue tension.

Tumors are fibrotic and characterized by abundant, remodeled, and cross-linked collagen that stiffens the extracellular matrix stroma. The stiffened collagenous stroma fosters malignant transformation of the tissue by increasing tumor cell tension to promote focal adhesion formation and potentiate growth factor receptor signaling through kinase. Importantly, collagen cross-linking requires fibronectin (FN). Fibrotic tumors contain abundant FN, and tumor cells frequently up-regulate the FN receptor α5β1 integrin. Using transgenic and xenograft models and tunable two- and three-dimensional substrates, we show that FN-bound α5β1 integrin promotes tension-dependent malignant transformation through engagement of the synergy site that enhances integrin adhesion force. We determined that ligation of the synergy site of FN permits tumor cells to engage a zyxin-stabilized, vinculin-linked scaffold that facilitates nucleation of phosphatidylinositol (3,4,5)-triphosphate at the plasma membrane to enhance phosphoinositide 3-kinase (PI3K)-dependent tumor cell invasion. The data explain why rigid collagen fibrils potentiate PI3K activation to promote malignancy and offer a perspective regarding the consistent up-regulation of α5β1 integrin and FN in many tumors and their correlation with cancer aggression.

Identification of a novel HLA-A allele, A*11:209 by sequence-based high-resolution typing in an HIV-infected individual

The novel allele A*11:209 shows three nucleotides difference from A*11:27 in exon 3.

The new allele HLA-DPB1*363:01 identified by sequence-based typing in a donor from the Chinese Marrow Donor Program

The new allele HLA-DPB1*363:01 most closely resembles DPB1*92:01, differing at a single position 191 (exon 2, codon 35).

In vitro subminimum inhibitory concentrations of macrolide antibiotics induce macrolide resistance in Mycoplasma pneumoniae

AIM

This study aims to investigate the inducing effect of subminimum inhibitory concentrations of macrolide antibiotics on Mycoplasma pneumoniae (M. pneumoniae) resistance to drugs.

MATERIALS AND METHODS

One M. pneumoniae reference strain M129 (ATCC 29342) and 104 clinical isolates were incubated at 37C for 6-8 days. Genomic DNA of M. pneumoniae was extracted using TIANamp Bacteria DNA kit and amplified by polymerase chain reaction (PCR).

RESULTS

Ten sensitive isolates obtained from 104 M. pneumoniae clinical isolates were induced by subminimum inhibitory concentrations of macrolide antibiotics. Among them, three were found to possess mutations in L4 and L22 ribosomal proteins. Two cases carried simultaneously the C162A and A430G mutations of L4 and the T279C mutation of L22. In addition, one case had only the A209T mutation of L4.

CONCLUSIONS

Repeated in vitro exposure to subminimum inhibitory concentrations of macrolide antibiotics could induce selective mutations in ribosomal genes of M. pneumoniae clinical isolates that cause resistance to macrolide antibiotics. Hippokratia 2015, 19 (1): 57-62.

A novel HLA-B allele, HLA-B*15:325, is identified by sequence-based typing in a HIV infected individual

The novel allele B*15:325 shows difference from B*15:02:01 at codon 127 resulting in changes from Asn to Ser.

Comparison of 16S rRNA gene PCR and blood culture for diagnosis of neonatal sepsis

Septicemia is a common cause of morbidity and mortality among newborns in the developing world. However, accurate clinical diagnosis of neonatal sepsis is often difficult because symptoms and signs are often nonspecific. Blood culture has been the gold standard for confirmation of the diagnosis. However, the sensitivity is low and results are usually not promptly obtained. Therefore, the diagnosis of sepsis is often based on clinical signs in association with laboratory tests such as platelets count, immature/total neutrophils ratio (I/T), and a rise in C-reactive protein (CRP). Polymerase chain reaction (PCR) methods for the detection of neonatal sepsis represent new diagnostic tools for the early identification of pathogens.

METHODS

During a 4-month prospective study, 16S rRNA PCR was compared with conventional blood culture for the diagnosis of neonatal bacterial sepsis. In addition, the relationship between known risk factors, clinical signs, laboratory parameters, and the diagnosis of sepsis was considered.

RESULTS

Sepsis was suspected in 706 infants from the intensive neonatal care unit. They all were included in the study. The number of positive cultures and positive PCR results were 95 (13.5%) and 123 (17.4%), respectively. Compared with blood culture, the diagnosis of bacterial sepsis by PCR revealed a 100.0% sensitivity, 95.4% specificity, 77.2% positive predictive value, and 100.0% negative predictive value. In this study, Apgar scores at 5 min, weight, icterus, irritability, feeding difficulties, gestational age (GA), premature rupture of membrane (PRM), platelets count, I/T, and a marked rise in CRP were important in establishing the diagnosis of sepsis in the newborn. In addition, weight, GA, PRM, irritability, duration of antibiotic usage, mortality rate, and number of purulent meningitis cases were significantly different between early-onset sepsis and late-onset sepsis.

CONCLUSION

16S rRNA PCR increased the sensitivity in detecting bacterial DNA in newborns with signs of sepsis, allowed a rapid detection of the pathogens, and led to shorter antibiotic courses. However, uncertainty about the bacterial cause of sepsis was not reduced by this method. 16S rRNA PCR needs to be further developed and improved. Blood culture is currently irreplaceable, since pure isolates are essential for antimicrobial drug susceptibility testing.

Involvement of decreased hypoxia-inducible factor 1 activity and resultant G1-S cell cycle transition in radioresistance of perinecrotic tumor cells

Cancer patients often suffer from local tumor recurrence after radiation therapy. Some intracellular and extracellular factors, such as activity of hypoxia-inducible factor 1 (HIF-1), cell cycle status and oxygen availability, have been suggested to affect DNA damage responses and eventual radioresistant characteristics of cancer cells. But when, where, and how these factors affect one another and induce cellular radioresistance is largely unknown. Here, we analyzed mechanistic and spatio-temporal relationships among them in highly heterogeneous tumor microenvironments. Experiments in vitro demonstrated that a decrease in the glucose concentration reduced the transcriptional activity of HIF-1 and expression of a downstream gene for the cell cycle regulator p27^Kip1 even under hypoxic conditions. Then, the proportion of cells in the radioresistant S phase increased, whereas that in the radiosensitive G₁ phase decreased, significantly. Immunohistochemical analyses showed that cancer cells in perinecrotic hypoxic regions, which should be under low-glucose conditions, expressed little HIF-1α, and therefore, were mainly in S phase and less damaged by radiation treatment. Continuous administration of glucagon, which increases the blood glucose concentration and so improves glucose availability in perinecrotic hypoxic regions, induced HIF-1α expression and increased radiation-induced DNA damage. Taken all together, these results indicate that cancer cells in perinecrotic regions, which would be under low-glucose and hypoxic conditions, obtain radioresistance by decreasing the level of both HIF-1 activity and p27^Kip1 expression, and adjusting their cell cycle to the radioresistant S phase.

Contribution of intestinal epithelial cells to innate immunity of the human gut--studies on polarized monolayers of colon carcinoma cells

The aim was to establish an in vitro model for studies of innate defence mechanisms of human intestinal epithelium. Ultrastructural characterization and determination of mRNA expression levels for apical glycocalyx and mucous components showed that polarized, tight monolayers of the colon carcinoma cell lines T84 and Caco2 acquire the features of mature- and immature columnar epithelial cells, respectively. Polarized monolayers were challenged with non-pathogenic Gram+ and Gram- bacteria from the apical side and the proinflammatory cytokines interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) from the basolateral side. Immune responses were estimated as changes in mRNA expression levels for the mucous component mucin-2 (MUC2), the glycocalyx components carcinoembryonic antigen (CEA), CEA-related cell adhesion molecule-1 (CEACAM1), CEACAM6, CEACAM7 and MUC3, the antimicrobial factors human beta-defensin-1 (hBD1), hBD2, hBD3 and lysozyme, the chemokine IL-8 and the cytokines IL-6 and TNF-alpha. Tight monolayer cells were generally unresponsive to bacterial challenge, but increased their hBD2 levels when challenged with Bacillus megaterium. T84 cells also increased their TNF-alpha levels upon bacterial challenge. Tight monolayer cells responded to cytokine challenge suggesting awareness of basolateral attack. TNF-alpha induced significantly increased levels of IL-8 and TNF-alpha itself in both cell lines suggesting recruitment and activation of immune cells in the underlying mucosa in vivo. Cytokine challenge also increased levels of CEACAM1, which includes two functionally different forms, CEACAM1-L and CEACAM1-S. In T84 cells, IFN-gamma was selective for CEACAM1-L while TNF-alpha upregulated both forms. Increased CEACAM1 expression may influence epithelial function and communication between epithelial cells and intraepithelial lymphocytes.

Concentration and detection of SARS coronavirus in sewage from Xiao Tang Shan Hospital and the 309th Hospital of the Chinese People's Liberation Army

A worldwide outbreak of severe acute respiratory syndrome (SARS) had been reported. Over 8439 SARS cases and 812 SARS-related deaths were reported to the World Health Organization from 32 countries around the world up to 5 July 2003. The mechanism of transmission of SARS-CoV has been limited only to close contacts with patients. Attention was focused on possible transmission by the sewage system because laboratory studies showed that patients excreted coronavirus RNA in their stools in Amoy Gardens in Hong Kong. To explore whether the stool of SARS patients or the sewage containing the stool of patients would transmit SARS-CoV or not, we used a style of electropositive filter media particle to concentrate the SARS-CoV from the sewage of two hospitals receiving SARS patients in Beijing, as well as cell culture, semi-nested RT-PCR and sequencing of genes to detect and identify the viruses from sewage. There was no live SARS-CoV detected in the sewage in these assays. The nucleic acid of SARS-CoV was found in the sewage before disinfection from both hospitals by PCR. After disinfection, SARS-CoV RNA could be detected from some samples from the 309th Hospital of the Chinese People's Liberation Army, but not from Xiao Tang Shan Hospital after disinfection. In this study, we found that the virus can survive for 14 days in sewage at 4 degrees C, 2 days at 20 degrees C, and its RNA can be detected for 8 days though the virus had been inactivated. In conclusion, this study demonstrates that the RNA of SARS-CoV could be detected from the concentrates of sewage of both hospitals receiving SARS patients before disinfection and occasionally after disinfection though there was no live SARS-CoV; thus much attention should be paid to the treatment of stools of patients and the sewage of hospitals receiving SARS patients.

Intraflagellar transport motors in Caenorhabditis elegans neurons

IFT (intraflagellar transport) assembles and maintains sensory cilia on the dendritic endings of chemosensory neurons within the nematode Caenorhabditis elegans. During IFT, macromolecular protein complexes called IFT particles (which carry ciliary precursors) are moved from the base of the sensory cilium to its distal tip by anterograde IFT motors (kinesin-II and Osm-3 kinesin) and back to the base by retrograde IFT-dynein [Rosenbaum and Witman (2002) Nat. Rev. Mol. Cell Biol. 3, 813–825; Scholey (2003) Annu. Rev. Cell Dev. Biol. 19, 423–443; and Snell, Pan and Wang (2004) Cell 117, 693–697]. In the present study, we describe the protein machinery of IFT in C. elegans, which we have analysed using time-lapse fluorescence microscopy of green fluorescent protein-fusion proteins in concert with ciliary mutants.

Inhibited anabolic effect of insulin-like growth factor-I on stromal bone marrow cells in endothelial nitric oxide synthase-knockout mice

AIMS

Insulin-like growth factor-I (IGF-I), parathyroid hormone (PTH) and PTH-related protein (PTHrP) are hormones that have anabolic effects on bone formation. The aim of this study was to investigate whether production of nitric oxide (NO) is involved in the effect of IGF-I and PTH/PTHrP on osteoblast-like cells.

METHODS

Bone marrow stromal cells from adult endothelial nitric oxide synthase (eNOS)-knockout (eNOSKO) mice and wild type (WT) counterparts were cultivated with osteogenic substances. The cells showed an osteoblastic phenotype measured as osteocalcin production and alkaline phosphatase activity. DNA synthesis was measured as [3H] thymidine incorporation in the bone marrow cells and in a human osteosarcoma cell-line (SaOS-2).

RESULTS

The stimulatory effect of IGF-I on thymidine incorporation seen in WT animals was absent in eNOSKO mice. Addition of a NO donor to eNOSKO cells recovered the effect of IGF-I on thymidine incorporation. PTH/PTHrP stimulated cell proliferation in both WT and eNOSKO mice. In SaOS-2 cells, incubation with IGF-I together with a NOS inhibitor resulted in an inhibition of the anabolic effect of IGF-I on cell proliferation.

CONCLUSIONS

The stimulatory effect of IGF-I on WT cell proliferation was abolished in eNOSKO cells, recovered by an NO donor and inhibited in osteosarcoma cells by a NOS inhibitor. The results indicate that the effect of IGF-I is dependent on NO production. The impaired IGF-I response may contribute to the bone defect formation seen in eNOSKO animals.

Improved efficacy of chemotherapy for glioblastoma by radiation-induced opening of blood-brain barrier: clinical results

PURPOSE

To improve the efficacy of chemotherapy for glioblastoma through the radiation-induced opening of the blood-brain barrier (BBB).

METHODS AND MATERIALS

In two previous articles, we have described the results of brain scanning using technetium 99m-labeled somatostatin and the measurement of methotrexate (MTX) concentrations in blood and cerebrospinal fluid (CSF) after i.v. injection. We discovered that the BBB and blood-cerebrospinal fluid barrier opened to a certain extent after 20- to 40-Gy irradiation, thus increasing the degree to which MTX permeated the brain tissue. On the basis of these findings, we retrospectively analyzed the outcome in 56 patients with glioblastoma given either chemotherapy (CCNU) after 20- to 40-Gy irradiation (28 patients) or radiation therapy alone (28 patients).

RESULTS

The 1-, 3-, and 5-year survival rates were 57.14%, 22.50%, and 15.00% in the combined-therapy group and 17.86%, 7.14%, and 3.57% in the radiotherapy alone group, respectively. The respective median survival times were 29.11 +/- 6.99 and 9.86 +/- 3.45 months (p < 0.001), which represented a statistically significant difference.

CONCLUSION

Our study further confirms that opening of the BBB induced by irradiation with 20-40 Gy may optimize the effects of intracranial chemotherapy.

[Therapeutic effect on glioblastoma of chemotherapy on the basis of brain irradiation]

OBJECTIVE

To study the efficacy of chemotherapy for glioblastoma on the basis of brain irradiation.

METHODS

It was previously reported that the permeability of the blood brain barrier (BBB) to methotrexate could be increased by brain irradiation. In this study, glioblastoma patients were divided into 2 groups, 28 patients in each group. On group of patients was treated with CCNU or BCNU after having given 20-40 Gy irradiation to the brain. The other group of patients received radiation treatment alone.

RESULTS

The 1-, 3-, and 5-year survival rate of the two groups of patients was 57.1%, 22.5%, 15.0% and 17.9%, 7.1%, 3.6%, respectively. The median survival time was 29.7 +/- 7.0 and 9.7 +/- 3.5 months, respectively (P < 0.001).

CONCLUSION

Increase in permeability of the BBB after 20-40 Gy brain irradiation may provide an optimal chance for intracranial chemotherapy of glioblastoma.

[Histological study on the polyhydroxybutyric ester(PHB) membrane used for guided bone regeneration around titanium dental implants]

OBJECTIVE

To evaluate the effects of PHB membrane around dental titanium implants used in guided bone regeneration technique.

METHODS

Endosseous cylindrical implants were placed in dogs' mandibles after extraction of all the mandibular premolars and the first molars immediately. Ideal implant placement sites were modified by creating standardized 3 mm x 5 mm facial dehiscent defects. The defects were covered with PHB membrane and titanium membrane respectively, then the membranes were fixed on the periosteum by sutures, and the remainder served as controls. Tissue closure was achieved with mattress and interrupted single sutures, and antibiotic injection was given to the dogs in the following 3 days. The dogs were divided into three groups according to the healing time of 1, 2 and 3 months, then the three groups of dogs were sacrificed. After that, tissue blocks containing the implants and the control ones were removed and studied by gross observation, X-ray radiograph and fluorescence microscope, and the surfaces of the membranes were observed by scanning electron microscope. The specimen used for light microscope study were fixed with 10% formaldehyde for 24 hours, and decalcified with 0.5 mol/L EDTA for 2 weeks. After the titanium implants were carefully removed, the tissue blocks were embedded into the paraffin wax, and the sections were obtained.

RESULTS

The PHB membrane degraded slowly and partly 3 months after placement, and the biodegradable property of the PHB membrane deserved a longer period of study; The bone defects covered with PHB and titanium membrane were filled with much more new bone than that of the control group.

CONCLUSION

PHB membrane can enhance bone formation and can be used for guided bone regeneration.

Regulation of expression of granulocyte-macrophage colony-stimulating factor in human bronchial epithelial cells: roles of protein kinase C and mitogen-activated protein kinases

GM-CSF has a major role in the immune and inflammatory milieu of the airway. Airway epithelial cells (AEC) are among the first targets of environmental stimuli and local cytokines, in response to which they can produce GM-CSF. The regulation of GM-CSF is only minimally understood in AEC. We hypothesized that GM-CSF expression in AEC would result from activation of protein kinase C (PKC) and subsequent activation of the extracellular signal-regulated kinase (MAPKerk1/2) pathway, so we investigated signal transduction pathways in human primary culture bronchial epithelial cells (HBECs). TNF-alpha, IL-1beta, and PMA induced the release of GM-CSF in HBECs. The robust response to PMA was not detected in SV40 adenovirus-transformed normal human bronchial epithelial cells (BEAS-2B). PMA and TNF-alpha stimulation of GM-CSF required activation of PKC (inhibition by staurosporine and bisindolylmaleimide I). GM-CSF expression was up-regulated by a nonphorbol PKC activator, but not by an inactive PMA analogue. PMA-induced GM-CSF production in HBECs did not require a Ca2+ ionophore and was not inhibited by cyclosporin A. Activation of MAPKerk1/2 via PKC was associated with and was required for GM-CSF production induced by PMA and TNF-alpha. The data demonstrate regulation of GM-CSF in HBECs by PKC pathways converging on the MAPKerk1/2 pathway and further define cell-specific regulation critical for local airway responses.

[In situ hybridization with digoxigenin-labelling oligonucleotide: an practical approach to skeletal tissues]

The purpose of this study was to investigate the in situ hybridization technique of paraffin-embedded skeletal tissues by non-radioactive labelling oligonucleotide, Five six-week-old male SD rats were selected and the proximal epiphyseal growth plates of bilateral tibiae were removed to be decalcified in 0.5 mol/L EDTA. The tissues were embedded by paraffin and the sections were treated and hybridized with RNase-free reagents. Control groups were set to testified the sensitivity and the specificity of the experiment. The results showed that this method preserved the integrate structures and effectively detected the mRNA of the tissues. These indicated that it was an efficient and practical approach to the biomolecular research of skeletal tissue.

[IGF-I mRNA expression level of cell in the interfaces of bone and four kinds of substitutive materials for bone tissues by the technique in situ hybridization]

Four kinds of substitutive materials for hard tissues were inserted into tibias of rat, effect of substitutive materials on IGF-I mRNA expression level of cell in the interfaces of bone and four kinds of substitutive materials were studied by the technique in situ hybridization. It showed that the biomaterials could affect the level of IGF-I mRNA expression, the enhanced expression level was associated with cell proliferation, formation of matrix and calcification, formation of new bone. Measurement of IGF-I mRNA could attribute to judge the functional state of cell, and to predict the final character of the interface.

[The research on effect of four kinds of substitutive materials for the bone tissues on IGF-I mRNA expression level of osteoblast]

The authors studied the expression level of IGF-I mRNA of osteoblasts cultured from the rats' calvarias, affected by four kinds of substitutive materials for bone tissues, using the technique in situ hybridization. The result showed that the substitutive materials could affect the expression level of IGF-I mRNA of osteoblasts. The measurement of expression regulation may be a parameter for evaluation of biocompatibility of substitutive materials for bone tissues.

Inheritance of somatic embryogenesis and organ regeneration from immature embryo cultures of winter wheat

Diallel analyses of F1 and reciprocal crosses among five winter wheat lines show that additive, non-additive, and cytoplasmic genetic effects were significant in the genetic control of somatic embryogenesis, shoot, and root induction frequencies as well as in numbers of somatic embryos, shoots, and roots. However, additive genetic effect appears to be most important since, in most cases a larger portion of the cross variation was accounted for by general combining ability. The results suggest that somatic embryogenesis and organ regeneration in winter wheat can be improved through genetic manipulation. Due to the presence of maternal effects, it may be critical to use a suitable genotype as a female parent in a selection program.