Effects of the surface characteristics of nano-crystalline and micro-particle calcium phosphate/chitosan composite films on the behavior of human mesenchymal stem cells in vitro.

Calcium phosphate (CaP) compounds, the main inorganic constituent of mammalian bone tissues, are believed to support bone precursor cell growth and osteogenic differentiation. Chitosan, a deacetylated derivative of chitin, is a versatile biopolymer to offer broad possibilities for cell-based tissue engineering. In the present study, different scales of CaP crystals on chitosan membranes were prepared for culture of human mesenchymal stem cells (hMSCs) in vitro. A series of aqueous CaP suspensions with different concentrations were mixed with chitosan solution and chitosan/calcium phosphate (C/CaP) films were fabricated by the solvent-casting method. With different weight ratios of CaP in chitosan solution, the various surface characteristics of nano-amorphous (C/CaP 0.1), nano-crystalline (C/CaP 0.5) and micro-particle (C/CaP 2) CaP compounds were examined by scanning electron microscopy and electron dispersion spectroscopy. X-ray diffraction on micro-particles of CaP indicated the formation of crystalline hydroxyapatite. The behavior of hMSCs, including proliferation, cell spreading and osteogenic differentiation, was studied on the C/CaP films. In basal culture medium, the incorporation of CaP into chitosan films could promote the proliferation of hMSCs. The C/CaP 0.5 film with connected CaP nano-crystals had better cellular viability. The fluorescence microscope images at 14 days of culture revealed extensive networks of F-actin filaments of hMSCs on chitosan, C/CaP 0.1 and C/CaP 0.5 films. The cellular morphology on C/CaP 2 film with discrete CaP micro-particles was partly restrained. In osteogenic medium, the alkaline phosphatase (ALP) activity of hMSCs increased and showed the process of osteogenic differentiation. The ALP levels on C/CaP 2 film were higher than those on C/CaP 0.1 and C/CaP 0.5 films. These results demonstrated that the crystallinity and topography of CaP on chitosan membranes could modulate the behaviors of cultured hMSCs in vitro.

Endoscopic comparison of the gastroduodenal safety and the effects on arachidonic acid products between meloxicam and piroxicam in the treatment of osteoarthritis.

Our objective was to evaluate the efficacy, the gastroduodenal safety, and the effects on arachidonic acid products of meloxicam, a new acidic enolic non-steroidal anti-inflammatory drug which preferentially inhibits cyclo-oxygenase-2 over cyclo-oxygenase-1, versus piroxicam in patients with osteoarthritis of the knee. Meloxicam 7.5 mg or piroxicam 20 mg daily was administered for 4 weeks in this double-blind parallel-groups randomised study. The efficacy for pain relief of the two tested medications was assessed by means of visual analogue scale and other clinical parameters. Pre- and post-treatment endoscopies were performed, and the findings were scored and recorded. The gastric fluid was aspirated at each time and prostaglandin E2, thromboxane B2 and leukotriene B4 were determined by ELISA. There was no significant difference between the groups regarding the primary efficacy. Changes in endoscopic findings by means of Lanza score showed statistically significant differences between the two treatment groups in favour of meloxicam at all sites--gastric, duodenal and total. Within-group comparisons showed a statistically significant difference (worsening) in gastric and total score with piroxicam, but no significant difference with meloxicam. The frequency of clinically relevant cases (total score >2) also showed a statistically significant worsening in the piroxicam group. The better GI tolerability of meloxicam was also suggested by fewer adverse GI events and no withdrawals due to adverse events compared with piroxicam. The pre-/post-study gastric juice concentration of PGE2, TXB2, and LTB4 in the meloxicam group was 135.2 +/- 85.8/71.2 +/- 32.2, 116.3 +/- 81.7/99.4 +/- 107.5 and 388 +/- 321/223 +/- 98 pg/ml respectively. The pre-/post-study gastric juice concentration of PGE2, TXB2 and LTB4 in the piroxicam group was 105.7 +/- 43.1/68.2 +/- 34.9, 94.0 +/- 50.9/105.9 +/- 121.1 and 625 +/- 1574/828 +/- 1464 pg/ml, respectively. Both meloxicam and piroxicam significantly inhibited gastric PGE2 levels after 4 weeks' treatment; however, there was no difference between these two groups. Neither of these medications had an effect on TXB2. Only meloxicam inhibited LTB4 concentration significantly, and the between-groups difference was significant. Meloxicam 7.5 mg once daily had better gastrointestinal tolerability and an efficacy comparable to that of piroxicam 20 mg over 4 weeks in patients with osteoarthritis of the knee.

Human monocyte adhesion and activation on crystalline polymers with different morphology and wettability in vitro.

This study evaluated the effects of crystalline polyamide (Nylon-66), poly(ethylene-co-vinyl alcohol) (PEVA), and poly(vinylidene fluoride) (PVDF) polymers with nonporous and porous morphologies on the ability of monocytes to adhere and subsequently activate to produce IL-1beta, IL-6, and tumor necrosis factor alpha. The results indicated monocyte adhesion and activation on a material might differ to a great extent, depending on the surface morphology and wettability. As the polymer wettability increases, the ability of monocytes to adhere increases but the ability to produce cytokines decreases. Similarly, these polymers, when prepared with porous surfaces, enhance monocyte adhesion but suppress monocyte release of cytokines. Therefore, the hydrophobic PVDF with a nonporous surface stimulates the most activity in adherent monocytes but shows the greatest inhibition of monocyte adhesion when compared with all of the other membranes. In contrast, the hydrophilic Nylon-66, which has a porous surface, is a relatively better substrate for this work. Therefore, monocyte behavior on a biomaterial may be influenced by a specific surface property. Based on this result, we propose that monocyte adhesion is regulated by a different mechanism than monocyte activation. Consequently, the generation of cytokines by monocytes is not proportional to the number of cells adherent to the surface.

Chronic idiopathic intestinal pseudo-obstruction.

Chronic idiopathic intestinal pseudo-obstruction (CIIP) is a rare heterogeneous clinical syndrome characterized by recurrent episodes of symptoms and signs of intestinal obstruction in the absence of a mechanically obstructing lesion. Dilatation of other viscera, such as the renal pelvis, ureter or urinary bladder, is identified in a minority of patients. We report the cases of two patients with CIIP presenting with abdominal fullness and constipation. Radiologic examination of the first patient revealed dilatation of the esophagus, stomach, duodenum and bowel loops up to the ascending colon. The nerve conduction velocity study of the right extremities revealed polyneuropathy and urinary bladder manometry revealed poor sensation. The patient had been admitted to our hospital three times for symptomatic relief within the prior six months. During the last admission, his symptoms persisted without response to medical treatment. Soon after discharge, the patient underwent surgery at another hospital and died of nutritional problems. The second patient was transferred to our hospital after an exploratory laparotomy was performed one month earlier. A radiographic examination revealed distention of the stomach, duodenum, small intestine and ascending colon, as well as bilateral hydronephrosis. Rheumatologic examination revealed no evidence of autoimmune disorder. The patient also had heavy proteinuria due to minimal change disease that was proven by renal biopsy. After receiving prokinetic, cathartic and corticosteroid medication for kidney disease, symptoms improved, but hydronephrosis persisted.

High frequency of cytotoxin-associated gene A in Helicobacter pylori isolated from asymptomatic subjects and peptic ulcer patients in Taiwan.

Cytotoxin-associated gene A (CagA), expressed in about 60% of H. pylori isolates in Western countries, may play a role in the pathogenesis of peptic ulcer. In this study, we determined the prevalence and significance of the H. pylori cagA gene and protein expression in Taiwan. Genomic DNA from antrum biopsies and H. pylori isolates were analyzed for cagA using polymerase chain reaction, Southern hybridization, or colony hybridization. CagA seropositivity was analyzed using Helico blots. In addition, Western blotting was performed to detect the CagA protein. About 94% of antrum tissues from both asymptomatic subjects and duodenal ulcer patients and all 76 H. pylori isolates (21 asymptomatic subjects, 39 with duodenal ulcers, 13 with gastric ulcers, 2 with gastric cancers, and 1 with mucosa-associated lymphoid tissue [MALT] lymphoma) were positive for the cagA gene. Moreover 77 out of 78 H. pylori-positive serum and all 27 H. pylori lysates had anti-CagA antibodies or CagA protein, respectively. H. pylori isolated from patients with various upper gastrointestinal diseases in Taiwan contained the cagA gene and expressed CagA protein at high frequencies.

Polyethylene failure in New Jersey low-contact stress total knee arthroplasty.

From January 1985 to December 1990, 598 consecutive New Jersey low-contact stress (LCS) total knee arthroplasties (TKAs) were performed for gonarthrosis. Among these 598 operations, 322 were with rotating platform elements and 276 were with meniscal bearing elements. During 5 to 8 years of follow-up, eight knees had severe symptomatic polyethylene failure that required revision surgery; all eight cases were meniscal bearing types. The failed polyethylene inserts were retrieved and studied. It was observed that there were four probable failure mechanisms associated with the catastrophic polyethylene wear. First, insufficient thickness of the meniscal bearing was the major reason for wear. Second, the malpositioning of the metal tibial tray in the transverse plane resulted in the breaking of the meniscal bearing. Third, the inability of the patellar to rotate due to tissue ingrowth made the polyethylene break. Last, yellowing of the subsurface of the meniscal bearing was a sign of polyethylene failure. These four possible failure mechanisms are all associated with the design of the meniscal bearing type of LCS knee prostheses. Therefore, it is suggested that the design of the LCS knee prosthesis should be modified.

Detection of alphafetoprotein-expressing cells in the blood of patients with hepatoma and hepatitis.

The presence of tumour cells in the blood circulation may predict disease recurrence and metastasis. We have evaluated the specificity and sensitivity of detecting hepatoma cells in blood using nested polymerase chain reaction with primers specific for the alphafetoprotein (AFP) gene. The nested polymerase chain reaction amplified a 270-base pair AFP DNA fragment from cDNA of Hep 3B hepatoma cells. In a reconstitution experiment, AFP mRNA was detected from peripheral mononuclear cells isolated from 10 ml of blood containing as few as ten Hep 3B cells. Peripheral mononuclear cells from the blood of 20 hepatoma patients were analysed, and 19 patients showed positive AFP mRNA expression. Seven of 13 samples from hepatitis patients also showed positive AFP mRNA expression. All five paired samples of peripheral blood or umbilical cord blood from pregnant mothers and their babies, respectively, showed positive AFP expression. None of 22 control samples was positive. The presence of AFP mRNA in the blood of hepatitis or hepatoma patients suggests the presence of circulating hepatoma cells or hepatocytes in the circulation. The high incidence of AFP mRNA in the blood of hepatoma patients supports the notion of early haematogenous spreading of the disease.

The accuracy of the rapid urease test and 13C-urea breath test in the diagnosis of Helicobacter pylori infection.

BACKGROUND: Helicobacter pylori (H. pylori) is an important predisposing factor in peptic ulcer disease. Many tests have been proposed, but there is no generally accepted single method for the detection of H. pylori. This study compared the four available methods in the detection of H. pylori. METHODS: One hundred and thirteen patients were studied with endoscopic biopsy. Biopsy specimens were examined with modified Giemsa stain and rapid urease (CLO) test. Serology (ELISA) and 13C-urea breath test (13C-UBT) were also performed. The 13C-UBT results were expressed at an excess delta 13CO2 excretion of 5 per mil as the upper limit. Multiple breath samples were collected 15, 30 and 60 minutes following 13C-urea ingestion (t = 15, 30, 60) in the first 60 patients. Gastric inflammatory changes were graded according to the Whitehead classification. The diagnostic gold standard was defined when three or more of the four test parameters showed positive. RESULTS: According to this diagnostic gold standard, the positive rates of H. pylori were 97.9% for duodenal ulcer, 81.8% for gastric ulcer, 47.6% for symptomatic gastritis and 13.6% for asymptomatics. Rapid urease test and the 13C-UBT had better sensitivity (93.6% and 96.2%) and accuracy (93.8% and 93.8%). The specificity and positive predictive value for rapid urease test was better than 13C-UBT (94.3% v.s. 88.6%, 97.3% v.s. 94.9% respectively). Modified Giemsa stain had the lowest sensitivity (87.2%), and the ELISA test had the lowest specificity (71.4%). Severity of the gastric inflammatory processes was directly correlated with the excess delta 13CO2 (r = 0.576). CONCLUSIONS: Both the CLO and 13C-UBT had higher accuracy in the detection of H. pylori. When the CLO test result is positive, there is little additional diagnostic benefit from performing other tests. If patients refuse endoscopic examination, 13C-UBT is a good alternative for the detection of H. pylori, either during diagnosis or follow-up after therapy.

Cystic lymphangioma of the transverse colon: report of a case and review of the literature.

A 32-year-old Chinese man with cystic lymphangioma of the transverse colon is described. He presented with a 1-year history of altered bowel habits. Double-contrast barium enema study demonstrated a submucosal lesion in the midportion of the transverse colon with intact mucosa. Computed tomography (CT) showed a round 3.0-cm submucosal cystic mass lesion. Colonoscopy revealed a smooth, soft polypoid mass on a broad base. He underwent segmental resection of the colon. Histologically, the lesion was characterized by cystic lymphangioma originating from the submucosa. The clinical features, radiology, appropriate treatment, and possible pathogenesis of colonic lymphangioma are discussed.

Soluble CD44 isoforms in serum as potential markers of metastatic gastric carcinoma.

A splice variant of CD44 (exon V4-V7) confers metastatic behavior in a rat carcinoma model; aberrant expression of splice variants has been detected on a variety of human tumor cell lines as well as primary and metastatic human tumors, including lymphomas, carcinomas (colon, thyroid, mamma, bladder), and glioma. We used enzyme-linked immunosorbent assay to determine the concentration of soluble CD44 in the serum samples of 10 normal individuals and 41 patients with various stages of gastric cancer. Soluble CD44S and its isoforms, V5 and V6, were present in the serum of normal individuals (288.53 +/- 18.33, 25.49 +/- 1.70, and 148.32 +/- 3.15 ng/ml, respectively). The concentrations of soluble CD44 V5 and V6 were elevated in patients with advanced gastric carcinoma (69.39 +/- 6.06 and 216.62 +/- 32.98 ng/ml, respectively). Serum CD44 V5 concentrations correlated with the extent of tumor invasion (T), the status of lymph node involvement (N), and distant metastasis (M) (TNM staging) (p < 0.05), whereas CD44S did not. These results suggest that detection of abnormal regulation of CD44 splicing could be helpful in gastric cancer diagnosis and disease evaluation.

Hydatid cysts in the liver.

A 67-year-old Taiwanese woman with multilocular hydatid cysts of the liver presented with a 5-month history of intermittent right upper abdominal discomfort. Abdominal ultrasonography and computed tomography showed multiple cysts in both lobes of the liver. Subsequent selective celiac angiography revealed an avascular space-occupying lesion in the right lobe. She underwent a radical excision of the cyst by total closed (without opening the wall) cystopericystectomy over segments 4, 5 and 6. Histologic study of the lesions showed three structural components: 1) an outer acellular laminated membrane, 2) a thin nucleated germinal membrane and 3) several protoscolices with Echinococcus granulosus suckers. The patient has been well for 5 years since her discharge. Although hydatid cysts of the liver are extremely rare in Taiwan, they may cause life-threatening complications and mortality. Making a preoperative diagnosis is important and is only possible if this rare disease is kept in mind.

A rare case of multiple intussusceptions: intense segmentary lipomatosis of the ileum.

We report a patient who presented with intestinal obstruction; his small intestine showed intense segmentary lipomatosis associated with unusually situated multiple intussusceptions. Preoperatively, we diagnosed intussusceptions in the ileocecal region by ultrasonography and computed tomographic scan. During surgery, the ileum was dilated and contained numerous movable polypoid masses. One reducible intussusception was encountered in the ileocecal region. In addition, an ileoileal intussusception that could not be reduced was resected with an end-to-end anastomosis. At histological examination, more than 150 submucosal lipomas were found.

An investigation of whether polymorphisms of cytochrome P4502E1 are genetic markers of susceptibility to alcoholic end-stage organ damage in a Chinese population.

The human cytochrome P4502E1 gene (P4502E1), coding for an ethanol-inducible nitrosamine-metabolizing P-450, is involved in the metabolism of ethanol and many known carcinogens. Recently, restriction fragment length polymorphisms (RFLPs) within the P4502E1 have been suggested as genetic markers of susceptibility to alcohol-induced liver disease but the previous studies disagree whether alcoholics with c1 or c2 allele are more susceptible to alcohol-induced liver diseases. Using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, we determined the RsaI and PstI polymorphism of P4502E1 in 77 Chinese alcoholic patients (54 with alcohol-induced cirrhosis and 23 with acute alcohol-induced pancreatitis) and 164 non-alcoholics and compared them with previously published data. The PCR-RFLPs showed three P4502E1 genotypes: type A, homozygote c1/c1; type B, heterozygote c1/c2; and type C, homozygote c2/c2. The RsaI and PstI polymorphism of P4502E1 were completely linked in both Chinese alcoholics and nonalcoholic controls. The rare allele (c2) occurs at similar frequency of 0.232 and 0.234 (P > .05) in nonalcoholic controls and alcoholics, respectively. The genotype distributions of P4502E1 between Chinese alcoholics and nonalcoholics are not significantly different. The genotype and allele frequencies of P4502E1 for Chinese are significantly different from those of Swedes, European-Americans, and African-Americans, respectively (P < .00001), but very similar to Japanese (P > .05). In conclusion, ethnic variations exist between Asians and Caucasians and between Asians and African-Americans. No allelic variants at loci associated with RsaI/PstI RFLPs result in phenotypes displaying greater susceptibility to alcohol-induced cirrhosis or alcoholism in Chinese populations, which contradicts previous reports from Japanese groups.

Captopril-induced agranulocytosis: a case report.

Captopril 12.5 mg twice daily was initially administered given to a woman with chronic renal failure and hypertension. Three weeks later, she developed chills, high fever and sore throat. Hemogram showed severe neutropenia; the white cell count showed 600/cu mm; bone marrow aspirate and biopsy revealed a paucity of myeloid series. Antineutrophil antibody was not detected in the serum. The neutrophil counts returned to normal after captopril was discontinued two weeks later. We recommend that the peripheral white blood cell count in patients whom captopril is prescribed must be carefully monitored in the first three months, particularly in those with impaired renal function.