Ordered YBCO sub-micron array structures induced by pulsed femtosecond laser irradiation

We report on the formation of organized sub-micron YBa(2)Cu(3)O(7) (YBCO) dots induced by irradiating femtosecond laser pulses on YBCO films prepared by pulse laser deposition with fluence in the range of 0.21 approximately 0.53 J/cm(2). The morphology of the YBCO film surface depends strongly on the laser fluences irradiated. At lower laser fluence (approximately 0.21 J/cm(2)) the morphology was pattern of periodic ripples with sub-micrometer spacing. Slightly increasing the laser fluence to 0.26 J/cm(2) changes the pattern into organized sub-micron dots with diameters ranging from 100 nm to 800 nm and height of 150 nm. Further increase of the laser fluence to over 0.32 J/cm(2), however, appeared to result in massive melting and led to irregular morphology. The mechanism and the implications of the current findings will be discussed. Arrays of YBCO sub-micron dots with T(c) = 89.7 K were obtained.

Estimating the magnitude of trastuzumab effects within patient subgroups in the HERA trial

BACKGROUND

Trastuzumab (Herceptin(R)) improves disease-free survival (DFS) and overall survival for patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer. We aimed to assess the magnitude of its clinical benefit for subpopulations defined by nodal and steroid hormone receptor status using data from the Herceptin Adjuvant (HERA) study.

PATIENTS AND METHODS

HERA is an international multicenter randomized trial comparing 1 or 2 years of trastuzumab treatment with observation after standard chemotherapy in women with HER2-positive breast cancer. In total, 1703 women randomized to 1-year trastuzumab and 1698 women randomized to observation were included in these analyses. Median follow-up was 23.5 months. The primary endpoint was DFS.

RESULTS

The overall hazard ratio (HR) for trastuzumab versus observation was 0.64 [95% confidence interval (CI) 0.54-0.76; P < 0.0001], ranging from 0.46 to 0.82 for subgroups. Estimated improvement in 3-year DFS in subgroups ranged from +11.3% to +0.6%. Patients with the best prognosis (those with node-negative disease and tumors 1.1-2.0 cm) had benefit similar to the overall cohort (HR 0.53, 95% CI 0.26-1.07; 3-year DFS improvement +4.6%, 95% CI -4.0% to 13.2%).

CONCLUSIONS

Adjuvant trastuzumab therapy reduces the risk of relapse similarly across subgroups defined by nodal status and steroid hormone receptor status, even those at relatively low risk for relapse.

Roles for negative cell regulator 14-3-3sigma in control of MDM2 activities

The 14-3-3sigma, upregulated by p53 in response to DNA damage, can have a positive-feedback impact driving p53 activities and is a human cancer epithelial marker downregulated in various tumors. However, the precise roles of 14-3-3sigma during tumorigenesis are not well characterized. Here, we show that 14-3-3sigma is a critical regulator of murine double minute oncogene (MDM2). 14-3-3sigma interacts with MDM2 at the RING domain. The C-terminal region of 14-3-3sigma binds to MDM2 very efficiently. Importantly, 14-3-3sigma overexpression leads to destabilization of MDM2 through enhancing MDM2 self-ubiquitination and accelerating turnover rate. Conversely, loss of 14-3-3sigma results in a significant increase in MDM2 protein. Moreover, live-cell images indicated that 14-3-3sigma can affect the location of MDM2 from the nucleus to the cytoplasm, and that MDM2-mediated cytoplasmic localization of p53 can be reversed by the presence of 14-3-3sigma. Significantly, we further showed that 14-3-3sigma causes MDM2 downregulation, thereby stabilizing p53 and inhibiting tumor growth in animal tumors. Also, 14-3-3sigma blocks MDM2-mediated retinoblastoma degradation and p53 NEDDylation. Our results provide evidence that 14-3-3sigma is a pivotal MDM2 regulator involved in blocking a variety of activities of MDM2.

Phase Behavior of Poly(9,9-di-n-hexyl-2,7-fluorene)

Here we report the phase behavior of poly(9,9-di-n-hexyl-2,7-fluorene) (PFH), which previously received little attention as compared to its homologues poly(9,9-di-n-octyl-2,7-fluorene) (PFO) and poly(9,9-di-(2'-ethylhexyl)-2,7-fluorene) (PFEH). By means of differential scanning calorimetry, X-ray diffraction, and electron microscopy, we show that there exist four different phases in PFH. The as-cast film is mainly composed of a mesomorphic beta phase with layer spacing of ca. 1.4 nm. This beta phase is inherently metastable and, upon heating above 175 degrees C, transforms into a crystalline (alpha) form that melts into a nematic (N) liquid above 250 degrees C. Upon stepwise cooling, the nematic melt crystallizes into the alpha phase first, followed by solid-solid transformation into another crystalline (alpha') form. Unit cell structure of the alpha form is monoclinic whereas that of the alpha' form is triclinic, but departures from strict orthogonality are slight (by ca. 6 degrees). These observations not only support our previous assignment of two crystalline forms (both orthorhombic in structure) in PFO but also provide insights to the crystalline nature of the polyfluorene series.

Ultrasound-mediated delivery of TIMP-3 plasmid DNA into saphenous vein leads to increased lumen size in a porcine interposition graft model

Progressive saphenous vein graft (SVG) narrowing and occlusion remains a major limitation of coronary artery bypass grafting and is an important target for gene therapy. Ex vivo adenoviral gene transfer of tissue inhibitor of metalloproteinase 3 (TIMP-3) reduces adverse SVG remodelling postarterialization, but concerns remain over the use of viral vectors in patients. Ultrasound exposure (USE) in the presence of echocontrast microbubbles (ECM) substantially enhances nonviral gene delivery. We investigated the effects of ultrasound-enhanced gene delivery (UEGD) of TIMP-3 plasmid on vascular remodelling in porcine SVG. Maximal luciferase activity (3000-fold versus naked plasmid alone) and TIMP-3 transgene expression in porcine vascular smooth muscle cells in vitro was achieved using USE at 1 MHz, 1.8 mechanical index (MI), 6% duty cycle (DC) in the presence of 50% (v/v) BR14 ECM (Bracco). These conditions were therefore utilized for subsequent studies in vivo. Yorkshire White pigs received carotid interposition SVG that were untransfected or had undergone ex vivo UEGD of lacZ (control) or TIMP-3 plasmids. At 28 d postgrafting, lumen and total vessel area were significantly greater in the TIMP-3 group (10.1+/-1.2 and 25.5+/-2.2 mm2, respectively) compared to untransfected (6.34+/-0.5 and 20.8+/-1.9 mm2) or lacZ-transfected (6.1+/-0.7 and 19.7+/-1.2 mm2) controls (P<0.01). These data indicate that nonviral TIMP-3 plasmid delivery by USE achieves significant biological effects in a clinically relevant model of SV grafting, and is the first study to demonstrate the potential for therapeutic UEGD to prevent SVG failure.

The stochastic piston problem

We obtain analytical solutions for the perturbed shock paths induced by time-varying random motions of a piston moving inside an adiabatic tube of constant area. The variance of the shock location grows quadratically with time for early times and switches to linear growth for longer times. The analytical results are confirmed by stochastic numerical simulations, and deviations for large random piston motions are established.

Association of CTLA4 gene A-G polymorphism with rheumatoid arthritis in Chinese

The aim of this study was to investigate the allelic association of a single nucleotide polymorphism in exon 1 of the cytotoxic T-lymphocyte antigen-4 (CTLA4) gene with rheumatoid arthritis (RA) in Chinese people. One hundred and eighty-six unrelated adults with RA and 203 randomly selected normal adults were studied. All were ethnic Chinese living in Taiwan. The CTLA4 A-G polymorphism was genotyped with a polymerase chain reaction (PCR) and digestion with the restriction enzyme BstEII. The genotype and allele frequencies of CTLA4 in patients with rheumatoid arthritis differed significantly from those of adult controls (P=0.022 and P=0.037, respectively). Genotype CTLA4 49 G/G and allele G were associated with an increased risk of RA (RR=1.72, 95% CI=1.15-2.57, P=0.008; RR=1.39, 95% CI=1.02-1.89, P=0.037, respectively), whereas genotype A/G and allele A were associated with protection against RA (RR=0.58, 95% CI=0.39-0.87, P=0.008 and RR=0.72, 95% CI=0.53-0.98, P=0.037, respectively). We concluded that, the CTLA4 49 A-G polymorphism is associated with RA in Chinese patients from Taiwan.

Analysis of sonographic features for the differentiation of benign and malignant breast tumors of different sizes

OBJECTIVE

To analyze the value of various sonographic features in differentiating benign from malignant breast tumors of different sizes to improve the diagnostic accuracy in small lesions.

METHODS

The sonographic features of 1203 histologically confirmed solid breast lesions were prospectively documented with respect to anteroposterior (AP) diameter/width ratio, shape, margin, echogenicity, echotexture, posterior echo and bilateral refraction sign. The sensitivity, specificity and accuracy of breast ultrasound were calculated for lesions grouped according to size (< or = 1, 1.1-2 and > 2 cm). Univariate and multiple logistic regression analyses including calculation of odds ratios for single sonographic features were used to analyze the significance of the different diagnostic features.

RESULTS

The accuracy of breast sonography in differentiating between benign and malignant tumors < or = 1, 1.1-2 and > 2 cm in size was 75.6%, 86.4% and 88.4%, respectively. Univariate analysis demonstrated that all sonographic features were significant in tumors > or = 1.1 cm. Shape, margin, echogenicity and echotexture were the significant factors in those tumors < or = 1 cm. Multiple logistic regression analysis demonstrated that margin, shape, posterior echo and echogenicity were the significant factors for differential diagnosis in tumors > 2 cm. Echogenicity, margin, shape, bilateral refraction sign and echotexture were the significant factors for tumors 1.1-2 cm. On multiple regression analysis, margin was the only significant factor for tumors < or = 1 cm.

CONCLUSION

Tumor margin is the most important sonographic feature in evaluating breast lesions in any size group. With the combination of significant factors and emphasis on specific features according to size of lesion, the diagnostic accuracy of ultrasound for the differential diagnosis of malignant and benign tumors may be improved.

Sonographic differentiation of invasive and intraductal carcinomas of the breast

The purpose of this study is to evaluate the diagnostic ability of ultrasound and define the sonographic features of symptomatic intraductal and invasive breast carcinoma. To achieve this the ultrasound features of 488 invasive carcinomas and 65 non-screening detected intraductal carcinomas were compared retrospectively. The features included size, AP/W (anteroposterior diameter/width) ratio, shape, margin, internal echogenicity, internal echotexture, posterior acoustic transmission, bilateral edge shadowing sign and calcifications. The sensitivity and specificity of the detection of calcifications by ultrasound in comparison with mammography were also studied. The accuracy of ultrasound diagnosis is 92.0% for invasive carcinoma of breast and 84.8% for intraductal carcinoma. Differentiation of ultrasound features of intraductal and invasive carcinoma can be based on the internal hypoechogenicity, loss of bilateral edge shadowing, posterior acoustic transmission, irregular shape and non-uniform internal echotexture with odds ratio of 0.3, 0.3, 0.4, 0.5 and 0.5, respectively. Internal echogenicity was the only significant differentiating factor on multiple logistic regression analysis. Non-comedo type ductal carcinoma in situ can be differentiated from comedo type by irregular shape with odds ratio of 0.3. The sensitivity, specificity and accuracy rate for the detection of calcifications in invasive carcinomas by ultrasound were 65.1%, 61.9% and 63.2%; in comedo type intraductal carcinoma 62.5%, 66.7% and 63.6%, and in non-comedo type intraductal carcinoma 30.0%, 86.7% and 64.0%, respectively. The ultrasound appearance of non-screening detected intraductal carcinoma is relatively isoechoic in comparison with invasive carcinoma. More than 60% of microcalcifications in comedo type intraductal carcinoma can be accurately demonstrated by ultrasound. However, the role of ultrasound in detecting symptomatic intraductal carcinoma warrants further study.

Co-administration of dextromethorphan during pregnancy and throughout lactation significantly decreases the adverse effects associated with chronic morphine administration in rat offspring

In this study, we have focused our investigation of the facts whether co-administration of a NMDA antagonist dextromethorphan (DM) with morphine during pregnancy and throughout lactation could prevent the adverse effects associated with chronic morphine administration in rat offspring. Adult female Sprague-Dawley rats were randomly separated into four groups and were received subcutaneous injection of either saline, morphine, morphine + dextromethorphan or dextromethorphan twice a day and progressively increased 1 mg/kg at 7-day intervals from a beginning dose of 2 mg/kg for both morphine and dextromethorphan. The rats were mated between days 7 and 8. Administration of drugs was continued during pregnancy. After rat offspring were born, the doses of morphine or dextromethorphan injected into the maternal rats were increased by 1 mg/kg every two weeks till the offspring were 30 day old. The results showed that mortality of morphine group is much higher than control group. The offspring of morphine group weighed significantly less than control group on postnatal day 14 (p14), p30 or p60. The antinociceptive effect of morphine on p14 rats was reduced in the morphine group and indicated the development of morphine tolerance. The hippocampal NMDA receptor densities have been shown decreased on p14 rats. The precipitated withdrawal symptoms were assessed on p7 rats. Rats in morphine group showed greater frequency of abdominal stretch and wet dog shake in 2 hr than control group. On the other hand, co-administration of DM with morphine effectively prevented all these adverse effects of morphine to the offspring rats. DM co-administered with morphine also partially prevented the development of morphine tolerance in maternal rats. If this effect of dextromethorphan is applied to clinical pregnant patients with morphine addiction or chronic pain, it will have a great value for the benefit of their children.

Antitumor and immunoenhancing activities of polysaccharide from culture broth of Hericium spp

The fruiting body and culture broth of many edible mushrooms contain water-soluble polysaccharides. Numerous researchers have reported that these polysaccharides have immunoenhancing effects. In this study, Hericium erinaceus and Hericium laciniatum were separately cultivated in a shaker at 25 degrees C for 25 days. Polysaccharides were extracted from the culture broth. The molecular weights were larger than 1 x 10(5) k Da and their polysaccharide components were mainly glucose in H. erinaceus and galactose in H. laciniatum. Furthermore, we investigated these two purified water-soluble polysaccharides for their anti-artificial pulmonary metastatic tumor and immunoenhancing effects in ICR mice. The results revealed that both polysaccharides had significant anti-artificial pulmonary metastatic tumor effects in mice (p < 0.05). Additionally, the polysaccharide from H. erinaceus was more effective than that from H. laciniatum. However, both of the polysaccharides enhanced the increase of T cells and macrophages. The numbers of CD4+ cells and macrophages were significantly higher in the test group than in the control group (p < 0.05). From our results, no differences were found between the two purified water-soluble polysaccharides in the antitumor effects and immunoenhancing activities (p > 0.05).

Antibiotic treatment for threatened abortion during the early first trimester in women with previous spontaneous abortion

BACKGROUND

We retrospectively examined the usefulness of antibiotic therapy for management of first-trimester threatened abortion in women with previous spontaneous abortion.

METHODS

From 1993 through 1999, women with first-trimester threatened abortion received antibiotic therapy. Only those with gestational age less than 9 weeks and previous spontaneous abortion were included in this analysis. Women with mild abdominal cramping received amoxicillin plus erythromycin for 1 week; those with severe abdominal pain received amoxicillin plus clindamycin for 1 week. Recurrence was documented on the basis of either lower abdominal pain or vaginal bleeding.

RESULTS

Of the 23 women included, 15 (65%) had abnormal vaginal flora (a score above 4, Nugent's criteria). Seven of 16 women who received amoxicillin plus clindamycin and three of seven who received amoxicillin plus erythromycin had complete resolution of lower abdominal pain and vaginal bleeding without recurrence (p=1). The recurrence rate was higher, though not significantly, in women with abnormal bacterial vaginal flora (8/15 vs. 2/8, p=0.379). Twenty-two (96%) of the 23 pregnancies were carried to term, with no identifiable neonatal anomalies.

CONCLUSIONS

These results suggest the usefulness of early antibiotic therapy in preventing pregnancy loss in women with threatened abortion early in the first trimester, and warrant further clinical trials.

Randomized trial of gastrojejunostomy with duodenal partition versus antrectomy in unresectable periampullary cancer

BACKGROUND

A newly-designed gastrojejunostomy with duodenal partition was hypothesized to be a relatively easier and safer gastric bypass procedure in interrupting the "food reentry", as compared with antrectomy, for patients with unresectable periampullary cancer.

METHODS

Thirty patients with unresectable periampullary malignancy were randomized to receive gastrojejunostomy with either duodenal partition or antrectomy, in addition to biliary bypass, to compare surgical risk and efficacy of the gastric bypass between these two groups.

RESULTS

Gastrojejunotomy with either duodenal partition or antrectomy could significantly shorten the gastric emptying time 6 weeks after operation. There was no significant difference between these two groups in gastric outlet obstruction (GOO) symptoms, gastric emptying time, and time for resuming oral diet intake after operation. The median operation time was shorter in the duodenal partition group (180 min) than in the antrectomy group (240 min), p < 0.01. The median blood loss was less in the duodenal partition group (250 ml) than in the antrectomy group (400 ml), (p = 0.01). Complications occurred in 3 (20%) patients with duodenal partition and in 7 (47%) patients with antrectomy, (p = 0.25). One duodenal stump leakage occurred in antrectomy group. Surgical mortality occurred in 2 patients with antrectomy.

CONCLUSIONS

Duodenal partition, with shorter operation time and less blood loss, had similar efficacy with antrectomy in correction of GOO. Therefore, duodenal partition could be a relatively easier and safer alternative to antrectomy in interrupting the "food reentry" in gastrojejunostomy for patients with unresectable periampullary cancer.

Cytotoxicity and immunogenicity of SACCHACHITIN and its mechanism of action on skin wound healing

SACCHACHITIN membrane, a weavable skin substitute made from the residual fruiting body of Ganoderma tsugae, has been demonstrated to promote skin wound healing. Prior to its clinical application, it is critical to learn more about any possible cytotoxicity, immunogenicity, or allergy response, and at least some of its mechanism(s) of action(s). In the present studies, it has been found that SACCHACHITIN suspension at less than 0.05% shows no cytotoxicity to the primary culture of rat fibroblasts. However, at higher concentrations (> or = 0.1%), it does reduce the growth of fibroblasts, based on MTT assays. This might be caused by positive charges on chitin molecules that are too strong, and may be harmful to the cell membrane. SACCHACHITIN showed no immunogenicity after it was inoculated into rats three times; however, the unmodified, purified rabbit type I and type II collagens did. Subcutaneous injection of SACCHACHITIN suspension into rats showed no gross allergic responses on skin. Nevertheless, it did cause local acute inflammation, as observed by histological investigation. This is similar to what occurred in the wound site covered with SACCHACHITIN membrane. The chemotactic effect of SACCHACHITIN was exhibited in both intact and wounded skin tissues. This may be one of the initial beneficial effects of SACCHACHITIN membrane to wound healing. The rapid acute inflammatory process was followed by the appearance of angiogenesis and granulation tissue formation, which occurred earlier than it normally would. Coverage of the wound area with SACCHACHITIN membrane also induced an earlier formation of scar tissue to replace the granulation tissue. A 1.5 x 1.5 cm(2) wound area covered by SACCHACHITIN completely healed by 21 days, while that covered with cotton gauze did not. Therefore, SACCHACHITIN is a safe biomaterial for use as a wound dressing for skin healing. Its promoting action for wound healing might be due to its chemotactic effect for inflammatory cells. This, in turn, may facilitate subsequent angiogenesis, granulation tissue formation, and faster new tissue formation, leading to faster wound healing.

Identification of Atractylodes plants in Chinese herbs and formulations by random amplified polymorphic DNA

AIM

An efficient, precise, and sensitive method for identifying Atractylodes plants has been established and will contribute significantly to quality control and scientific analysis in Chinese traditional medicine.

METHODS

Twenty primers were applied for setting up the RAPD (randomly amplified polymorphic DNA) markers of Atractylodes plants, Atractylodes lancea DC (A lancea DC), Atractylodes japonica Koidz (A japonica K), and Atractylodes ovata DC (A ovata DC). The primer OPF03, OPF05, and OPF14 could discriminate them successfully. The results were also able to apply on the Chinese formulations with Atractylodes purchased from local markets.

RESULTS

RAPD was used to investigate phylogenetic relationships among and within closely related species. RAPD analysis reflects heritable changes in the nucleotides sequence in both the coding and noncoding regions, because it is conducted directly from the DNA level. This work first conducted RAPD analysis of Atractylodes plants to establish their RAPD makers.

CONCLUSION

The RAPD markers could be applied extensively in the Chinese herbal formulations.

Hemodynamic Response of Modified Fluid Gelatin Compared with Lactated Ringer's Solution for Volume Expansion in Emergency Resuscitation of Hypovolemic Shock Patients: Preliminary Report of a Prospective, Randomized Trial

The objective of this study was to compare the cardiac and hemodynamic responses to a rapid infusion of 1000 ml of modified fluid gelatin (group A) or 1000 ml of lactated Ringer's solution (group B) in emergency room patients suffering from shock. This prospective, randomized, open, noncrossover study was performed at a medical center university hospital in a surgical resuscitation room in the emergency department. The subjects were 34 patients with either hypovolemic or neurogenic shock who were admitted to the emergency room. A resuscitation protocol according to Advanced Trauma Life Support (ATLS) with an additional central venous line or Swan-Ganz catheters for hemodynamic monitoring was used. Physical parameters and hemodynamic variables were measured at baseline and 15 minutes, 30 minutes, and 1 hour after the infusion of each fluid. In both groups the mean arterial blood pressure (MAP), systolic and diastolic pressure, central venous pressure (CVP), and pulmonary artery occlusion pressure (PAOP) increased significantly. The CVP and PAOP increased significantly more in the modified fluid gelatin resuscitation group. In patients with traumatic or neurogenic shock due to acute volume deficiency, there was significantly better hemodynamic improvement, judged by CVP and PAOP measurements using the modified fluid gelatin for volume replacement than with lactated Ringer's solution during the first hour of resuscitation.

High-performance liquid chromatographic analysis for the characterization of triterpenoids from Ganoderma

A high-performance liquid chromatographic (HPLC) analysis of triterpenoids from Ganoderma is developed and validated in an attempt to explore a way to differentiate a number of species of the genus Ganoderma. Results show that 64 samples examined in this study could be divided into 18 groups based on characteristics of the HPLC pattern of triterpenoids. This result also conforms with those of the morphological examination and the interfertility test by di-monokaryotic mating. The HPLC analysis of triterpenoids further reveals that differentiation among samples from three different regions each of the two species G. lucidum and G. tsugae is workable. Even then, an incorrect designation is found for two of the groups of samples that were originally classified as G. resinaceum but showed different morphological characteristics and mating incompatibility. In conclusion, an HPLC analysis of triterpenoids is a simple and easy way to differentiate among different species of the genus Ganoderma.

Reappraisal of surgical risk and prognosis for periampullary lesions after pancreaticoduodenectomy

BACKGROUND

Pancreaticoduodenectomy remains a high-risk and formidable challenge to many surgeons. This study reappraised the surgical risk and prognosis for periampullary lesions in patients undergoing pancreaticoduodenectomy before and after 1990.

METHODS

Data on 308 patients with periampullary lesions undergoing pancreaticoduodenectomy were analyzed. The surgical risk was assessed by a variety of factors. Prognoses for periampullary cancers were determined and compared.

RESULTS

The overall surgical mortality, morbidity and pancreatic leakage were 12.7%, 47.7% and 14.9% respectively. Surgical morbidity (43.5% vs. 51.6%) and pancreatic leakage (12.9% vs. 16.8%) did not change significantly before 1990 and after 1990. Surgical mortality significantly decreased from 17.1% before 1990 to 8.7% after 1990 (p = 0.043). Surgeons having more experience in performing pancreaticoduodenectomy (count > 20) made significantly lowest rates of surgical mortality, pancreatic leakage and bile leakage, as compared with those having performed this surgery with medium count (10-20) or low count (< 10). Statistically, pancreatic leakage was highly associated with operative mortality, (p < 0.001). As analysed by multivariate logistic regression, the most independent risk factor of surgical mortality after pancreaticoduodenectomy was pancreatic leakage (odds ratio = 12.1), followed by date of operation (odds ratio = 2.5). The 5-year survival rate for overall periampullary cancers was 23.0%, with the highest in ampulla of Vater cancer (32.7%), followed by duodenal cancer (18.0%), distal common bile duct cancer (12.3%) and pancreatic head cancer (5.5%) (p < 0.001).

CONCLUSIONS

Surgical morbidity following pancreaticoduodenectomy remains high and unchanged while surgical mortality has significantly reduced. Pancreatic leakage is the most independent risk factor of surgical mortality. Patients with periampullary lesions appear to benefit from the experience of surgeons. The overall 5-year survival is most favorable for ampulla of Vater cancer and worst for pancreatic head cancer.

Non-functioning islet cell tumors of the pancreas--a multicentric clinical study in Taiwan

BACKGROUND/AIMS

Islet cell tumors of the pancreas are rare. Functioning tumors are characterized by the symptoms induced by the hormones they secrete. The clinical behaviors of non-functioning tumors are quite different. In this retrospective study, we scrutinized 16 patients with non-functioning islet cell tumor in three tertiary university hospitals in Taiwan during a 20-year period.

METHODOLOGY

There were 12 women and 4 men with a mean age of 47 years. Body-weight loss, abdominal pain and palpable mass were the most frequent symptoms.

RESULTS

The mean size of these tumors was 8.9 cm in diameter. Ten tumors were located at the tail of pancreas, the other 6 located at the head. Except for hyperbilirubinemia in 2 patients, none of the patients with non-functioning islet cell tumor showed abnormalities of laboratory data including serum tumor markers. Preoperative detection of these tumors by imaging modalities was not difficult due to the large size of the tumors. However, differentiation with functioning tumor or ductal cell carcinoma required clinical and imaging correlation. Fourteen tumors were malignant including 8 with regional lymph nodes involvement, 3 with locally microscopic invasion, 2 with hepatic metastasis and 2 with nearby organ invasion.

CONCLUSIONS

Even with its malignant behavior, non-functioning islet cell tumor still possessed a good prognosis after adequate surgical removal in comparison with a higher mortality rate of ductal carcinoma of the pancreas.

Antiplatelet activity of Staphylococcus aureus lipoteichoic acid is mediated through a cyclic AMP pathway

In this study, Gram-positive Staphylococcus aureus lipoteichoic acid (LTA) dose dependently (0.1-1.0 microg/mL) and time dependently (10-60 min) inhibited platelet aggregation in human platelets stimulated by agonists (i.e., thrombin and collagen). LTA also dose dependently inhibited intracellular Ca(2+) mobilization in human platelets stimulated by collagen. In addition, LTA (0.5 and 1.0 microg/mL) dose dependently increased the formation of cyclic AMP but not cyclic GMP in platelets. LTA (0.5 and 1.0 microg/mL) did not significantly increase the production of nitrate within a 10-min incubation period. Rapid phosphorylation of a platelet protein of M(r) 47,000, a marker of protein kinase C activation, was triggered by PDBu (0.03 microM). This phosphorylation was dose dependently inhibited by LTA (0.5 and 1.0 microg/mL) within a 10-min incubation period. Furthermore, LTA (0.5 and 1.0 microg/mL) also inhibited platelet aggregation induced by PDBu (0.03 microM) in human platelets. These results indicate that the antiplatelet activity of LTA may be involved in the increase of cyclic AMP, leading to inhibition of intracellular Ca(2+) mobilization and protein kinase C activity. Therefore, LTA-mediated alteration of platelet function may contribute to bleeding diathesis in septicemic and endotoxemic patients.

Splenic abscess--a changing trend in treatment

Fifteen patients with splenic abscesses were evaluated between 1985 and 1995. The most common predisposing factors were remote infection, diabetes mellitus and heart disease. Common clinical presentations included leucocytosis, fever, left upper quadrant abdominal pain and left pleural effusion. Four patients with splenic abscesses smaller than 4 cm in diameter were treated with antibiotics alone, and 1 in this treatment group died. Among the 10 patients with splenic abscesses larger than 4 cm in diameter receiving percutaneous drainage, 9 (90%) were successfully cured, including 8 with unilocular abscesses and 1 with multilocular abscesses. Two patients underwent splenectomy. In conclusion, percutaneous drainage using ultrasound or computed tomography guidance may be recommended as the treatment of choice for splenic abscess larger than 4 cm in diameter. Antibiotics alone may sometimes be considered for splenic abscesses smaller than 4 cm in diameter. Splenectomy is reserved for those cases where medical treatment has failed.

Diverticular disease of the small bowel

BACKGROUND/AIMS

The clinical picture of small bowel diverticula has not been well-clarified because of its infrequent incidence and limited case number in most published reports. We evaluated a large series of small bowel diverticula and further compared the clinical picture of the diverticula at different parts of small bowel.

METHODOLOGY

The medical records of 88 patients with diverticular disease of the small bowel were reviewed from 1979-1997. This study included all diverticula from duodenum to ileum.

RESULTS

The most common small bowel diverticulum was duodenal diverticulum (45%), followed by Meckel's diverticulum (23%). The most common clinical presentation was abdominal pain (48.9%), followed by gastrointestinal bleeding (29.5%). However, among the Meckel's diverticula, gastrointestinal bleeding (60%) was the most common presentation. The accurate diagnostic rate for diverticula, overall, was 25.0%. Thirty-nine (44.3%) of the diverticula were found incidentally. Twenty-three cases (26.1%) were diagnosed by gastrointestinal barium study. Thirty-eight (42.1%) diverticula were left alone without any sequela, and the remaining 55 (56.8%) diverticula needed either bowel resection (30.7%) or diverticulectomy (26.1%). All of the Meckel's diverticula were treated by surgery. Postoperative complication occurred in 9 (10.3%) patients. Hospital mortality rate was 3.4%.

CONCLUSIONS

Duodenal diverticulum was the most common small bowel diverticulum. Abdominal pain and gastrointestinal bleeding were the most common clinical presentations. The small bowel diverticula, except for Meckel's diverticulum, did not need to be treated if there were no significant symptoms.

Prospective study of gastric outlet obstruction in unresectable periampullary adenocarcinoma

Controversy persists regarding the role of prophylactic gastrojejunostomy in patients with unresectable periampullary adenocarcinoma. In review of the retrospective series, presence of gastric outlet obstruction (GOO) has been claimed to be a bad prognostic sign. This prospective study aimed to clarify the necessity of routine prophylactic gastrojejunostomy in patients with unresectable periampullary adenocarcinoma. The incidence and prognostic significance of GOO were also evaluated. Sixty-six patients with unresectable periampullary adenocarcinoma were enrolled. They were divided into 2 groups to receive either a single biliary bypass or a double bypass (concomitant gastric and biliary bypasses) if they had GOO. The single bypass group was followed up to assess the incidence of GOO and subsequent need of a gastric bypass. Prognostic factors were evaluated by univariate and multivariate analyses. Forty-four (67%) of the overall 66 patients presented with GOO at the time of diagnosis. There was no statistical difference regarding the morbidity and mortality between the 2 groups, except longer (7 days) hospital stay in the double bypass group. Seven (31.8%) of the 22 patients in the single bypass group subsequently developed GOO an average of 6.2 +/- 1.0 months after their initial biliary bypass. By univariate analysis, significant prognostic factors for unresectable periampullary adenocarcinoma were: GOO (p = 0.0379), pancreatic head origin (p = 0. 0146 by univariate analysis), and distant metastasis (p < 0.0001). After multivariate analysis, only pancreatic head origin and distant metastasis remained significant independent factors of poor prognosis. In conclusion, gastrojejunostomy should be performed prophylactically in addition to a biliary bypass in patients with unresectable periampullary adenocarcinoma. The presence of GOO is not an independent factor of poor prognosis, but a reflection of the aggressive biologic behavior of pancreatic head adenocarcinoma.

Glucagonoma syndrome: a case report

Glucagonoma is a very rare islet cell tumor of the pancreas. We present a case of pancreatic tail tumor with the typical glucagonoma syndrome of necrolytic migratory erythema (NME), diabetes mellitus (DM), anemia, weight loss and glossitis. After complete resection of the pancreatic tumor, the glucagonoma syndrome subsided. In reviewing 120 cases of glucagonoma in the literature, the average tumor diameter was 3.6 cm. Most (68.1%) of the tumors occurred in the pancreatic tail. Two-thirds of the reported glucagonomas were malignant and 53.5% metastasized to other organs. The curative resection rate was 45.8%. A triad of pancreatic tumor, NME and DM should lead to the diagnosis of glucagonoma.