The development of a rapid prototyping prosthetic socket coated with a resin layer for transtibial amputees

This article proposes a type of transtibial socket composed of an inner layer fabricated by a rapid prototyping (RP) machine and an outer layer coated with unsaturated polyester resin. This work integrates contemporary technologies including a handheld scanner and CAD systems, to design a thin primary socket shape and then manufactures the socket using a fused deposition-modeling machine. To prevent breakage caused by the layer-based forming process and to reinforce flexural strength, the current research coats the preliminary RP socket with a layer of unsaturated polyester resin. After shaping the proximal brim of the resin-reinforced RP socket to match the specific stump, this study assembles and aligns a shank and a prosthetic foot to form a prosthesis set. After completing a trial safety walk wearing the prosthesis, which is satisfactory to the amputee and a registered prosthetist, this research measures interface pressures between the stump and the resin-reinforced RP socket. Experiment results demonstrate that the resin-reinforced RP socket is applicable for transtibial amputees. In addition to strengthening the FDM socket and producing consistent socket fit, this study also demonstrates a feasible procedure that employs current technologies to design and manufacture transtibial sockets without plaster moulds.

Effect of PHY906 on capecitabine (CAP)-induced diarrhea in patients with GI malignancies

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Background: 15.4% of pts with GI cancers treated with CAP alone at 1250mg/m2 BID D1–14 q 3 wks (14/7) develop G3/4 diarrhea (Hoff et al. JCO, 2001). PHY906 composed of 4 herbs, Scutellaria baicalensis Georgi, Glycyrrhiza uralensis Fisch., Ziziphus jujuba Mill., and Paeonia lactiflora Palla, has been used to treat diarrhea since approximately 300AD. Preliminary studies showed synergistic activity of PHY906 with chemotherapeutics and reduction of chemotherapy-induced GI toxicities, especially chemotherapy-induced diarrhea (CID). Methods: We prospectively evaluated 44 pts treated on a clinical study with CAP plus PHY906 for diarrhea (experimental arm) and compared to historical data by Hoff et al., CAP 14/7 alone arm (control arm). Experimental arm consisted of pts with refractory solid tumors in phase I and gemcitabine-refractory advanced pancreatic cancer (APC) in phase II. Ph I pts received PHY906 800mg BID D1–4 with escalating doses of CAP (1000mg/m2→1250mg/m2→1500 mg/m2→1750mg/m2 BID) D1 -7 q 2 wks (7/7), until MTD. Ph II treated pts with APC at 1500 mg/m2 and PHY906 800mg BID D1–4. Toxicity was assessed per NCI-CTCAE-v3.0. In addition, correlative chemokine (IL-2, IL-4, IL-5, etc) levels will be quantified by cytometric bead array. Results: 44 pts (30M/14F; median 64yr) received 209 cycles (median:3, r:<1–14) of PHY906 in the four CAP-7/7 escalation cohorts in Phase I (19 pts), then at the MTD of 1500mg/m2 BID in Phase II (25 pts). Phase I pts had GI malignancies; 15 (63%) had APC and 6 (25%) colorectal. Of all phase I and phase II pts, G3/4 diarrhea was observed in 5 (11.4%) pts, without G3/4 constipation. One pt with APC who received 3 cycles at the 1500mg/m2 dose level was diarrhea-free until he was removed from the study; he continued on single-agent CAP at 1000mg/m2 BID and developed G3 diarrhea. Conclusions: In this study, G3/4 diarrhea was reduced by 19.5% in pts treated with PHY906 (experimental arm) when combined with CAP 7/7 compared to historical controls (control arm). As an underlying mechanism of CID may include cytokine activation, evalation of cytokines is ongoing.

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A phase II study of capecitabine (CAP) plus PHY906 in patients (pts) with advanced pancreatic cancer (APC)

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Background: Gemcitabine (G) is regarded as the standard treatment for pts with APC. However, a standard second-line chemotherapy regimen has yet to be defined after G. PHY906, a 4-herb traditional Chinese medicine has a history of > 1,800 yrs of human use to treat GI symptoms including diarrhea. Preclinical studies showed that PHY906 may potentiate antitumor activity of CAP in human PANC-1 xenograft (ASCO 2007). A phase I study showed that CAP can be escalated up to 1750 mg/m2 PO BID on d1- 7 and PHY906 800mg PO BID on d1–4 q 2 wks with no DLTs (ASCO, 2008). Delivered dose-intensity of CAP was similar at 1750mg/m2 dose level as 1500mg/m2. Therefore, 1500mg/m2 of CAP and PHY906 was further tested in a phase II study as second-line treatment in pts with APC. Methods: Pts with G-refractory APC with ECOG PS <2 were treated with CAP 1500mg/m2 d1–7 with PHY906 800mg d1–4 q 2 wks. Response was assessed by CT scan according to RECIST q 6 wks and toxicity according to NCI-CTC v3.0. Primary objective is overall survival. Secondary objectives include overall RR, PFS and measurement of cytokines to assess inhibition of NF-kappa B, a possible mechanism responsible for PHY906's pharmacological activity. Results: As of January 5, 2009, 25 pts have been enrolled. Baseline characteristics include median age, 65 (range, 40–85); male/female,15/10; ECOG PS 0/1, 4/19; median cycles: 3 (r: 0.5–15). At this point 5 pts are still in active treatment. 4 pts have confirmed OS > 6 ms (1 still on study) with 2 further pts approaching 6 ms. Among evaluable pts, 1 had PR (5.3%), 11 SD (57.9%) and 7 PD (36.8%) after initial restaging scan. 36 % pts had >30% reduction in CA19–9 as biochemical response. There were 7 deaths on/within 30 days of study treatment, 6 related to PD and 1 had acute MI. G3/4 toxicities diarrhea 3/25 (12%), fatigue, 1/25 (4%), HFS 1/25 (4%) and mucositis 1/25 (4%). 1 pt was removed from study due to G3 HFS. Biomarker studies (IL4, GM-CSF, TNF-alpha, IL10, MCP-1, IL2, IL6) are ongoing. Conclusions: This is the first clinical study to evaluate a botanical formulation PHY906 with CAP in G-refractory APC pts. CAP + PHY906 regimen appears a safe and feasible salvage therapy in APC and warrants further investigation. In addition, PHY906 may have a cytoprotective antidiarrheal and anti-HFS effect, making treatment with CAP more tolerable.

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Review of dengue fever cases in Hong Kong during 1998 to 2005

OBJECTIVE

To describe the epidemiology, clinical and laboratory findings, and outcomes of patients presenting locally with dengue.

DESIGN

Retrospective review of case records.

SETTING

Public hospitals, Hong Kong.

PATIENTS

Medical records of all laboratory-confirmed dengue patients admitted to public hospitals during 1998 to 2005 were reviewed retrospectively.

RESULTS

A total of 126 cases were identified, 123 (98%) being dengue fever and three (2%) dengue haemorrhagic fever. One patient who had blood transfusion-acquired dengue fever was highlighted. A total of 116 (92%) cases were 'imported', while 10 (8%) were local. Among the 56 dengue cases confirmed by reverse transcription-polymerase chain reaction, dengue virus type 1 was the most common accounting for 48% of them, followed by type 2, type 3, and type 4 responsible for 23%, 16%, and 13%, respectively. Only type 1 and type 2 were present in locally acquired infections. The median age of the patients was 38 years and the mean duration of hospitalisation was 6 days. There was no mortality, and nearly all patients (98%) presented with fever. Other symptoms at presentation included: myalgia (83%), headache (65%), fatigue (59%), and skin rash (60%). More than one third of patients had gastro-intestinal and upper respiratory complaints. Maculopapular skin rash was the most common physical finding. Thrombocytopenia, neutropenia, and lymphopenia were present in 86%, 78%, and 69% of the patients, respectively. In only 29% of the patients was dengue fever included in the initial differential diagnosis. The demographic, clinical, and laboratory findings as well as outcomes did not differ significantly among the four dengue serotypes, but the lowest lymphocyte counts of type 3 was lower than the other serotypes (P=0.004).

CONCLUSION

When physicians encounter patients with a relevant travel history, presenting with fever and skin rash, and having compatible haematological findings, dengue fever should be included in the differential diagnosis.

Clinical characteristics of nosocomial norovirus outbreaks in Hong Kong

Norovirus outbreaks occur worldwide every year and have become more frequent over the last few years. There were extensive outbreaks in Hong Kong from May to July 2006 and our aim was to describe nosocomial outbreaks from 1 May 2006 to 31 July 2006 in this retrospective observational study. A total of 38 confirmed norovirus outbreaks involving 218 patients were identified. Most of these patients were elderly with a mean age of 74.5 years (range: 3 months to 97 years); 62% of them were either totally or partially dependent for help with daily activities, 83.9% had underlying chronic medical problems and 56% had limited mobility. In all, 97.2% of individuals presented with diarrhoea and only 46.3% of them had vomiting. The median duration for diarrhoea was 3 days and the longest 24 days. The median duration of vomiting was one day and the longest 15 days. Fever occurred in one-third of all cases. Reverse transcriptase-polymerase chain reaction was positive for norovirus in 72.6% cases. We conclude that nosocomial norovirus infection often involves frail elderly patients with limited mobility and that these patients may have more prolonged symptoms.

Serological identification and bioinformatics analysis of immunogenic antigens in multiple myeloma

Identifying appropriate tumor antigens is critical to the development of successful specific cancer immunotherapy. Serological analysis of tumor antigens by a recombinant cDNA expression library (SEREX) allows the systematic cloning of tumor antigens recognized by the spontaneous autoantibody repertoire of cancer patients. We applied SEREX to the cDNA expression library of cell line HMy2, which led to the isolation of six known characterized genes and 12 novel genes. Known genes, including ring finger protein 167, KLF10, TPT1, p02 protein, cDNA FLJ46859 fis, and DNMT1, were related to the development of different tumors. Bioinformatics was performed to predict 12 novel MMSA (multiple myeloma special antigen) genes. The prediction of tumor antigens provides potential targets for the immunotherapy of patients with multiple myeloma (MM) and help in the understanding of carcinogenesis. Crude lysate ELISA methodology indicated that the optical density value of MMSA-3 and MMSA-7 were significantly higher in MM patients than in healthy donors. Furthermore, SYBR Green real-time PCR showed that MMSA-1 presented with a high number of copy messages in MM. In summary, the antigens identified in this study may be potential candidates for diagnosis and targets for immunotherapy in MM.

Blockade of interleukin 6 accelerates acinar cell apoptosis and attenuates experimental acute pancreatitis in vivo

BACKGROUND

It remains unclear whether interleukin (IL) 6 plays a role in initiating either the inflammatory or antiapoptotic responses in severe acute pancreatitis. This study examined the effect of neutralizing antibody against IL-6 on the induction of pancreatic acinar cell apoptosis and attenuation of the severity of severe acute pancreatitis.

METHODS

Experiments were conducted on laboratory mice with severe acute pancreatitis induced by lipopolysaccharide injection following six injections of caerulein at intervals of 6 h. Neutralizing monoclonal anti-IL-6 antibody was administered either 5 min or 2 h after the first caerulein injection. Apoptosis in pancreatic sections was determined by the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick-end labelling method.

RESULTS

Administration of caerulein and LPS induced an increase in serum amylase and IL-6 levels, severe acute pancreatitis, pancreatitis-associated lung injury, and phosphorylation of signal transducer and activator of transcription (STAT) 3 in the pancreas. A neutralizing antibody against IL-6 effectively suppressed these responses. Application of IL-6 neutralizing antibody caused the induction of apoptosis in the pancreatic acinar cells of mice with acute pancreatitis.

CONCLUSION

Blocking IL-6 suppresses STAT-3 activation in the pancreas and consequently attenuates the severity of severe acute pancreatitis by promotion of pancreatic acinar cell apoptosis.

The effect of global SSTR5 gene ablation on the endocrine pancreas and glucose regulation in aging mice

INTRODUCTION

The purpose of this study was to examine the effect of global gene ablation of SSTR5 on the endocrine pancreas, insulin secretion, and glucose tolerance in aging mice, as SSTR5 is a primary regulator of insulin secretion in the mouse pancreas.

METHODS

Global SSTR5-/- mice were generated and genotypes were verified using Southern blot and RT-PCR. Glucose tolerance and in vivo insulin secretion in SSTR5-/- and WT mice were examined using intraperitoneal glucose tolerance test (IPGTT;1.2-2.0 mg/kg) at 3 and 12 months of age (n = 8 per group). Basal and glucose-stimulated insulin secretion in vitro was studied using the isolated perfused mouse pancreas model at 3 and 12 months. Pancreata were removed and levels of insulin, glucagon, somatostatin, and SSTR1 were studied using immunohistochemical analysis along with H&E staining of the pancreata.

RESULTS

Genotyping verified the absence of SSTR5 in SSTR5-/- mice. IPGTT demonstrated that 3-month-old SSTR5-/- mice were glucose intolerant despite similar insulin secretion both in vivo and in vitro and enlarged islets. At 12 months of age, SSTR5-/- mice had basal hypoglycemia and improved glucose intolerance associated with hyperinsulinemia in vivo and in vitro and enlarged islets. SSTR5-/- mice had increased insulin clearance at 3 and 12 months of age. SSTR1 expression was significantly increased in islets at 3 months of age, but was nearly absent in islets at 12 months of age, as was somatostatin staining in SSTR5-/- mice.

CONCLUSIONS

These results suggest that both SSTR5 and SSTR1 play a pivotal role in insulin secretion and glucose regulation in mice and that their regulatory effects are age-related.

Method for the control of NOx emissions in long-range space travel

The wheat straw, an inedible biomass that can be continuously produced in a space vehicle has been used to produce activated carbon for effective control of NOx emissions from the incineration of wastes. The optimal carbonization temperature of wheat straw was found to be around 600 degrees C when a burnoff of 67% was observed. The BET surface area of the activated carbon produced from the wheat straw reached as high as 300 m2/g. The presence of oxygen in flue gas is essential for effective adsorption of NO by activated carbon. On the contrary, water vapor inhibits the adsorption efficiency of NO. Consequently, water vapor in flue gas should be removed by drying agents before adsorption to ensure high NO adsorption efficiency. All of the NO in the flue gas was removed for more than 2 h by the activated carbons when 10% oxygen was present and the ratio of carbon weight to the flue gas flow rate (W/F) was 30 g min/L, with a contact time of 10.2 s. All of NO was reduced to N2 by the activated carbon at 450 degrees C with a W/F ratio of 15 g min/L and a contact time of 5.1 s. Reduction of the adsorbed NO also regenerated the activated carbon, and the regenerated activated carbon exhibited an improved NO adsorption efficiency. However, the reduction of the adsorbed NO resulted in a loss of carbon which was determined to be about 0.99% of the activated carbon per cycle of regeneration. The sufficiency of the amount of wheat straw in providing the activated carbon based on a six-person crew, such as the mission planned for Mars, has been determined. This novel approach for the control of NOx emissions is sustainable in a closed system such as the case in space travel. It is simple to operate and is functional under microgravity environment.

Effects of different exercise modes on mineralization, structure, and biomechanical properties of growing bone

Weight bearing during exercise plays an important role in improving the mechanical properties of bone. The effect on bone of non-weight-bearing exercise such as swimming remains controversial. To investigate the effects of exercise mode on growing bone, 29 male Wistar rats (7 wk old) were randomly assigned to a running exercise group (Run, n = 9), a swimming exercise group (Swim, n = 10), or a nonexercise control group (Con, n = 10). During an 8-wk training session (20-60 min/day, 5 days/wk), the Run rats were trained at progressively increasing running speeds (12-22 m/min), and weights attached to the tail of the Swim rats were progressively increased from 0 to 2% of their body weight. The bone mineral density of the proximal tibiae of the Run rats was significantly higher than in the Swim (P < 0.05). Femoral wet weights of the two exercise groups were significantly higher than in the control group (P < 0.05). Interestingly, the percent difference between the tissue wet weight and dry weight (water content ratio), which is related to bone mechanical properties, was significantly higher in the tibiae of the Swim rats and the femora of both exercise groups compared with controls (P < 0.05). Extrinsic as well as intrinsic biomechanical material properties were measured in a three-point bending test. Bone mechanical properties of the tibiae and femora of rats in the Swim and Run groups were significantly greater than those in the control group (P < 0.05). In summary, different modes of exercise may benefit bone mechanical properties in different ways. The specific effects of swimming exercise (non-weight-bearing exercise) on bone require further study.

Decomposition of NO on the alkalized Pt/Al2O3

Catalytic decomposition of NO on platinum catalysts at 873-1,173 K was investigated in the present work. The yield of N2 in the NO decomposition process was significantly increased on the alkalizing Pt/Al2O3 catalyst. The enhancement may be attributed to a trap of additional NO molecules by basic sites ofthe alkalized catalyst. The interstitially adsorbed species (NaOH(NO)Pt) might increase the NO adsorption strength during the catalytic NO reduction process. Pt on the high acidity HY was also active for catalytic decomposition of NO. Nevertheless, its activity decreased at higher temperatures (>1,073 K) because of the distortion of the HY framework. Combined results of XPS (X-ray photoelectron spectra) and TPR (temperature programmed reduction) showed that PtO and PtO2 were the main active species on the alkalized Al2O3 and HY during NO reduction.

Local symmetry breaking by impurities and mode splitting in doped SmS

We introduce the idea of local symmetry breaking by impurities to explain the recently observed splitting of the J=0-->1 propagating excitation in doped Sm1-xYxS. While preserving the global cubic symmetry of the crystal, Y impurities change the local crystal-field environment of each Sm ion from cubic to tetragonal, thereby splitting the J=1 triplet into a m(i).J=0 level with energy Delta(1) and a m(i).J=+/-1 doublet with energy Delta(2)>Delta(1). A model with a randomly oriented quantization axis m(i) fits not only the observed mode frequencies but also their intensities, which strongly depends on the wave vector.

Electron solvation in two dimensions

Ultrafast two-photon photoemission has been used to study electron solvation at two-dimensional metal/polar-adsorbate interfaces. The molecular motion that causes the excess electron solvation is manifested as a dynamic shift in the electronic energy. Although the initially excited electron is delocalized in the plane of the interface, interactions with the adsorbate can lead to its localization. A method for determining the spatial extent of the localized electron in the plane of the interface has been developed. This spatial extent was measured to be on the order of a single adsorbate molecule.