[The beginnings and evolution of a pancreatic surgeon: a technical morphological analysis in first 5 years]

Objective: To explore the development of the pancreatic surgeon technique in a high-volume center. Methods: A total of 284 cases receiving pancreatic surgery by a single surgeon from June 2015 to December 2020 were retrospectively included in this study. The clinical characteristics and perioperative medical history were extracted from the medical record system of Zhongshan Hospital,Fudan University. Among these patients,there were 140 males and 144 females with an age (M (IQR)) of 61.0 (16.8) years(range: 15 to 85 years). The "back-to-back" pancreatic-jejunal anastomosis procedure was used to anastomose the end of the pancreas stump and the jejunal wall. Thirty days after discharge,the patients were followed by outpatient follow-up or telephone interviews. The difference between categorical variables was analyzed by the Chi-square test or the CMH chi-square test. The statistical differences for the quantitative data were analyzed using one-way analysis of variance or Kruskal-Wallis H test and further analyzed using the LSD test or the Nemenyi test,respectively. Results: Intraoperative blood loss in pancreaticoduodenectomy between 2015 and 2020 were 300,100(100),100(100),100(0),100(200) and 150 (200) ml,respectively. Intraoperative blood loss in distal pancreatectomy was 250 (375),100 (50),50 (65),50 (80),50 (50),and 50 (100) ml,respectively. Intraoperative blood loss did not show statistical differences in the same operative procedure between each year. The operative time for pancreaticoduodenectomy was respectively 4.5,5.0(2.0),5.5(0.8),5.0(1.3),5.0(3.3) and 5.0(1.0) hours in each year from 2015 to 2020,no statistical differences were found between each group. The operating time of the distal pancreatectomy was 3.8 (0.9),3.0 (1.5),3.0 (1.8),2.0 (1.1),2.0 (1.5) and 3.0(2.0) hours in each year,the operating time was obviously shorter in 2018 compared to 2015 (P=0.026) and 2020 (P=0.041). The median hospital stay in 2020 for distal pancreatectomy was 3 days shorter than that in 2019. The overall incidence of postoperative pancreatic fistula gradually decreased,with a incident rate of 50.0%,36.8%,31.0%,25.9%,21.1% and 14.8% in each year. During this period,in a total of 3,6,4,2,0 and 20 cases received laparoscopic operations in each year. The incidence of clinically relevant pancreatic fistula (grade B and C) gradually decreased,the incident rates were 0,4.8%,7.1%,3.4%,4.3% and 1.4%,respectively. Two cases had postoperative abdominal bleeding and received unscheduled reoperation. The overall rate of unscheduled reoperation was 0.7%. A patient died within 30 days after the operation and the overall perioperative mortality was 0.4%. Conclusion: The surgical training of a high-volume center can ensure a high starting point in the initial stage and steady progress of pancreatic surgeons,to ensure the safety of pancreatic surgery.

Unintrusive multi-cancer detection by circulating cell-free DNA methylation sequencing (THUNDER): development and independent validation studies

BACKGROUND

Early detection of cancer offers the opportunity to identify candidates when curative treatments are achievable. The THUNDER study (THe UNintrusive Detection of EaRly-stage cancers, NCT04820868) aimed to evaluate the performance of ELSA-seq, a previously described cfDNA methylation-based technology, in the early detection and localization of six types of cancers in the colorectum, esophagus, liver, lung, ovary and pancreas.

PATIENTS AND METHODS

A customized panel of 161,984 CpG sites was constructed and validated by public and in-house (cancer: n=249; non-cancer: n=288) methylome data, respectively. The cfDNA samples from 1,693 participants (cancer: n=735; non-cancer: n=958) were retrospectively collected to train and validate two multi-cancer detection blood test models (MCDBT-1/2) for different clinical scenarios. The models were validated on a prospective and independent cohort of age-matched 1,010 participants (cancer: n=505; non-cancer: n=505). Simulation using the cancer incidence in China was applied to infer stage-shift and survival benefits to demonstrate the potential utility of the models in the real world.

RESULTS

MCDBT-1 yielded a sensitivity of 69.1% (64.8%‒73.3%), a specificity of 98.9% (97.6%‒99.7%) and tissue origin accuracy of 83.2% (78.7%‒87.1%) in the independent validation set. For early stage (I‒III) patients, the sensitivity of MCDBT-1 was 59.8% (54.4%‒65.0%). In the real-world simulation, MCDBT-1 achieved the sensitivity of 70.6% in detecting the six cancers, thus decreasing late-stage incidence by 38.7%‒46.4%, and increasing 5-year survival rate by 33.1%‒40.4%, respectively. In parallel, MCDBT-2 was generated at a slightly low specificity of 95.1% (92.8%-96.9%) but a higher sensitivity of 75.1% (71.9%-79.8%) than MCDBT-1 for populations at relatively high risk of cancers, and also had ideal performance.

CONCLUSION

In this large-scale clinical validation study, MCDBT-1/2 models showed a high sensitivity, specificity, and accuracy of predicted origin in detecting six types of cancers.

20-MHz phased array ultrasound transducer for in vivo ultrasound imaging of small animals

In vivo ultrasound imaging with phased array transducers is of great importance for both clinical application and biomedical research. In this work, relaxor ferroelectric PMN-0.28PT single crystal with very high piezoelectric constant d₃₃ ≥ 2000 pC/N and electromechanical coupling coefficient k₃₃ ∼ 0.92 is used to fabricate high-frequency phased array transducers. A 128-element 20-MHz phased array transducer is successfully fabricated, and the optimized performance of -6 dB average bandwidth of ∼ 84 % and insertion loss of -43 dB are achieved. The axial and lateral imaging resolutions of the transducer are determined to be 81 µm and 243 µm, respectively. With Verasonics image platform, in vivo fisheye images are acquired, demonstrating the potential application of our developed high-frequency phased array transducer for biomedical research on small animals.

[Pancreas multidisciplinary team optimizes the diagnosis and treatment of pancreas-related diseases and improves the prognosis of pancreatic cancer patients]

Objectives: To evaluate the role of pancreas multidisciplinary team(MDT) clinic in the diagnosis of pancreatic diseases,patient compliance with MDT advice,and the impact of MDT on the postoperative survival of patients with pancreatic cancer. Methods: The study included 927 patients(554 males,373 females,aged (58.1±13.3)years (range: 15 to 89 years)) that had visited the pancreas MDT clinic of Zhongshan Hospital from May 2015 to December 2021,and 677 patients(396 males, 281 females, aged (63.6±8.9)years(range: 32 to 95 years)) who underwent radical surgery and with pathologically confirmed pancreatic adenocarcinoma from January 2012 to December 2020,of whom 79 patients had attended the pancreas MDT. The clinical and pathological data were collected and analyzed retrospectively. Diseases were classified in accordance with 2010 WHO classification of tumors of the digestive system and usual clinical practices. The Kaplan-Meier method was used for drawing the survival curve and calculating the survival rate. The univariate analysis was done by Log-rank test and the multivariate analysis was done by COX proportional hazards model. Survival rates were compared using χ2 test. Results: Among the 927 patients that had visited the MDT clinic,233 patients(25.1%) were referred due to undetermined diagnosis. A direct diagnosis was made in 109 cases (46.8%,109/233) by the MDT clinic, of which 98 were consistent with the final diagnosis,resulting in an accuracy of 89.9%(98/109). The direct diagnosis rate in the recent years(36.6%(41/112),from June 2019 to December 2021) decreased compared to that in the previous years(56.2%(68/121),from May 2015 to May 2019),yet the accuracy in the recent years(90.2%,37/41) was basically the same as before (89.7%,61/68). The rate of compliance of the entire cohort was 71.5%(663/927), with the compliance rate in the recent two and a half years(81.4%,338/415) remarkably higher than that in the previous four years(63.4%,325/512). Patients with pancreatic cancer that attended the MDT exhibited a trend toward longer median postoperative survival than patients that did not attend the MDT,but the difference was not statistically significant(35.2 months vs.30.2 months,P>0.05). The 1-year and 3-year survival rates of patients that attended the MDT were significanly higher than patients that did not attend the MDT(88.6% vs. 78.4%,P<0.05;32.9% vs. 21.9%,P<0.05,respectively),but the 5-year survival rate was not statistically different(7.6% vs. 4.8%,P>0.05). Conclusions: The pancreas MDT clinic is an accurate and convenient way to diagnose intractable pancreatic diseases,and in the recent years the patients' compliance rate with MDT advice has increased. Pancreatic cancer patients that have attended the MDT have higher 1-year and 3-year postoperative survival rates,but the long-term survival benefits of MDT still needs to be proved by clinical studies on a larger scale.

[Advances on the management of renal lesion in glycogen storage disease type I]

Glycogen storage disease (GSD) is a group of congenital defects involved in the synthesis and decomposition of glycogen. As the most common type, GSD I is caused by mutations in glucose-6-phophate catalytic subunit (type Ia), or glucose-6-phosphate transporter (type Ib). Both defects can lead to hypoglycemia and accumulation of glycogen in the liver and kidney. So renal lesion is one of the main complications, which may manifest as increased glomerular filtration rate in the early stage, followed by microalbuminuria and decreased glomerular filtration rate and proteinuria. Subsequently it may progress into renal interstitial fibrosis, glomerulosclerosis, and eventually renal failure. Early detection and timely intervention of renal impairment are very important. Here we mainly describe the progress of diagnosis and treatment on the kidney disease of glycogen storage disease type I.

Virtual and reality: risk and protective factors of cyber and offline relational victimization

Background

Cyber victimization (CV) and offline relational victimization (ORV) both impede adolescent development and might pose self-harm or suicide. The aim of this work is to examine the risk and protective factors of the two experiences across gender.

Methods

A total of 1,712 junior and senior high school students who came from 34 schools randomly sampled from northern Taiwan. The study included multi-facet supports (i.e. maternal, paternal, grandparent, peer, and teacher supports), positive and negative peer connections, smartphone addiction and family characteristics (i.e. parental marital status and self-perceived financial status) as predictors.

Results

10.3% of the participants reported CV more than once (56.8% girls) and 35.2% of them reported ORV more than once (52.4% girls) in the last three months. Results of logistic regression models showed that smartphone addiction positively related to CV (boys: OR = 1.3, 95% CI = 1.1-1.6; girls: OR = 1.6, 95% CI = 1.3-2.0) and ORV (boys: OR = 1.2, 95% CI = 1.1-1.4; girls: OR = 1.2, 95% CI = 1.1-1.3) regardless gender. Negative peer connection related to ORV only among boys (OR = 1.4, 95% CI = 1.7-1.7). Low-level self-perceived financial status related to having CV (OR = 2.8, 95% CI = 1.4-5.5) and ORV (OR = 2.0, 95% CI = 1.2-3.4) only among girls. Interestingly, paternal support is the only significant protective factor among three family supports. Paternal support negatively associated with CV (OR = 0.8, 95% CI = 0.6-0.9) and ORV of boys (OR = 0.8, 95% CI = 0.7-0.9) as well as ORV of girls (OR = 0.8, 95% CI = 0.6-0.9). Furthermore, teacher support negatively associated with girls' CV (OR = 0.8, 95% CI = 0.6-0.9) and boys' ORV (OR = 0.8, 95% CI = 0.7-0.9).

Conclusions

The study identified a few gender-specific risk factors. For both gender, to prevent CV and ORV, supporting adolescents to avoid smartphone addiction is critical. Enhancing paternal support and teacher support can be effective in preventing adolescents' cyber and offline relational victimization.

Key messages

Paternal and teacher supports, rather than other sources of supports, are protective factors of cyber victimization and offline relational victimization among adolescents. Smartphone addiction, regardless of gender, not only positively associated with cyber victimization but also positively related to offline relational victimization.

[Clinical analysis and prognosis factors of malignancy in the patients with mucinous cystic neoplasms of the pancreas]

Objective: To examine clinic pathological features of mucinous cystic neoplasms (MCN) of the pancreas and explore the prognosis factors associated with malignant transformation of MCN of the pancreas. Methods: This multicenter retrospective study included all patients with pancreatic MCN underwent surgery at Department of Pancreatic Surgery, Zhongshan Hospital of Fudan University between January 2008 and December 2018 and patients with MCN who confirmed by postoperative pathology from Multicenter Pancreatic Cystic Tumor Database. There were 50 males (14.4%) and 297 females (85.6%) and the mean age was 48.6 years (range: 24-77 years). According to the pathological results, all patients were divided into benign lesion group (including MCN and which associated with low/medium grade dysplasia) and malignant lesion group (including MCN with high-grade dysplasia or invasive carcinoma) . The preoperative clinical pathology and imaging features of the two groups were analyzed, and the risk factors associated with malignant transformation of MCN were statistically analyzed. Results: This multicenter retrospective study included 347 patients. Twenty-four of the 347 patients were malignant, including 7 males and 17 females. Univariate analysis showed that age, gender, carcino-embryonic antigen (CEA) , CA19-9, CA125, tumor maximum diameter, and tumor location were remarkably different in the two groups (P<0.05) . Logistic regression analysis found that the preoperative tumor maximum diameter (OR=1.023, 95% CI: 1.002-1.045, P=0.035) was an independent risk factor for MCN malignant transformation. Conclusions: Age, gender, CEA, CA19-9, CA125, tumor maximum diameter, and tumor location are important features of MCN malignant lesions.The maximum diameter of the preoperative tumor is an independent risk factor for MCN malignant transformation.

[Diagnostic value and patient compliance of a pancreas-oriented multidisciplinary clinic: a retrospective analysis from a Chinese pancreatic disease center]

Objective: To evaluate the role of multidisciplinary team (MDT) clinic in the diagnosis of pancreatic diseases and patient compliance with MDT advice in the current medical system. Methods: The study included 512 patients that had visited the pancreas-oriented MDT clinic of Zhongshan Hospital between May 2015 and May 2019.The clinical and pathological data were collected and analyzed retrospectively. Diseases were classified in accordance with 2010 WHO classification of tumors of the digestive system and usual clinical practices. Compliance was determined according to whether a patient received corresponding therapies or undergoing further checks or follow-ups. Results: Among the 512 patients that had visited the MDT clinic, 121 patients were referred due to undetermined diagnosis. Classified according to the final diagnosis, the rate of undetermined diagnosis in different disease categories from high to low in order was inflammatory diseases of the pancreas (75.0%, 24/32), other lesions of the pancreas (56.1%,23/41), pancreatic cystic lesions (19.1%,17/89), pancreatic carcinomas (18.3%,48/262) and pancreatic neuroendocrine neoplasms (pNEN)(10.2%,9/88). The MDT clinic made diagnosis to 68 patients directly with an accuracy of 89.7%. The rate of compliance in the entire cohort was 63.4%. The rate of compliance of patients from June 2017 to May 2019 (68.4%) was higher than that of patients from May 2015 to May 2017(59.6%). The compliance rate of patients in different disease categories from high to low in order was inflammatory diseases of the pancreas(84.4%, 27/32), pancreatic carcinomas (67.9%, 178/262), pNEN(60.2%,53/88), other lesions of the pancreas (56.1%,23/41), and pancreatic cystic lesions(49.4%, 44/89). The compliance rate of patients with different MDT advice from high to low in order was best supportive care(78.6%,22/28), antitumor approaches beyond surgery(71.6%,159/222), further tests(62.6%, 77/123), surgery(53.7%, 65/121) and follow-up(49.2%, 31/63). In patients suggested for surgery, the compliance rate of patients with carcinomas(67.4%, 33/49) was higher than patients with other kinds of neoplasms. Conclusions: MDT clinic could facilitate the diagnosis of pancreatic diseases conveniently and inexpensively. The overall compliance rate of MDT clinic patients is rather low, and patients with carcinomas have a relative high rate of compliance with the suggestion of surgery.

[The value of preoperative CA19-9 combined with platelet-to-lymphocyte ratio in predicting invasive malignancy in intraductal papillary mucinous neoplasms]

Objective: To explore preoperative predictive markers for invasive malignancy in intraductal papillary mucinous neoplasm(IPMN). Methods: The retrospective case-controlled study was adopted.Seventy-nine patients who underwent surgery and with pathologically confirmed IPMN from January 2005 to December 2014 at Department of Pancreatic Surgery, Zhongshan Hospital Fudan University were enrolled.Forty-six patients were male and 33 were female,with an average age of (62.9±8.9)years (range:37-82 years).Tumor sites:56 tumors were located at the head of the pancreas,22 were located at the body and tail of the pancreas,and 1 was located across the whole pancreas.Surgical procedures: 51 patients underwent pancreaticoduodenectomy, 22 patients underwent distal pancreatectomy, 4 patients underwent segmental pancreatectomy and 2 patients underwent total pancreatectomy.IPMNs were classified into non-invasive lesions and invasive carcinomas according to the histopathological findings of the tumor.Thirty-two tumors were non-invasive lesions and 47 were invasive carcinomas.The preoperative findings were compared between patients with non-invasive IPMN and patients with invasive carcinoma by univariate analysis using t test and χ(2) test accordingly,and factors with statistically significance were subsequently submitted to multivariate analysis. Results: Univariate analysis showed that tumor size(P=0.022), carcinoembryonic antigen(P=0.012), CA19-9(P=0.011), lymphocytes(P=0.034), neutrophil-to-lymphocyte ratio(P=0.010)and platelet-to-lymphocyte ratio(PLR)(P=0.004)were predictive markers with statistical significance.Multivariate analysis showed that CA19-9(P=0.012)and PLR(P=0.025) were independent predictive markers for invasive malignancy in IPMN.The area under curve of the combination factor of CA19-9 and PLR(0.864) was larger than that of CA19-9(0.806) or PLR(0.685) alone, and all the authentic indicators of the combination factor were better than those of each alone. Conclusions: CA19-9 and PLR are independent predictive markers for invasive malignancy in IPMN.The combination of CA19-9 and PLR has improved efficacy than each alone.

Dengue virus nonstructural protein 1 activates platelets via Toll-like receptor 4, leading to thrombocytopenia and hemorrhage

Dengue virus (DENV) infection, the most common mosquito-transmitted viral infection, can cause a range of diseases from self-limiting dengue fever to life-threatening dengue hemorrhagic fever and shock syndrome. Thrombocytopenia is a major characteristic observed in both mild and severe dengue disease and is significantly correlated with the progression of dengue severity. Previous studies have shown that DENV nonstructural protein 1 (NS1), which can be secreted into patients’ blood, can stimulate immune cells via Toll-like receptor 4 (TLR4) and can cause endothelial leakage. However, it is unclear whether DENV NS1 can directly induce platelet activation or cause thrombocytopenia during DENV infection. In this study, we first demonstrated that DENV but not Zika virus cell culture supernatant could induce P-selectin expression and phosphatidylserine (PS) exposure in human platelets, both of which were abolished when NS1 was depleted from the DENV supernatant. Similar results were found using recombinant NS1 from all four serotypes of DENV, and those effects were blocked in the presence of anti-NS1 F(ab’)₂, anti-TLR4 antibody, a TLR4 antagonist (Rhodobacter sphaeroides lipopolysaccharide, LPS-Rs) and a TLR4 signaling inhibitor (TAK242), but not polymyxin B (an LPS inhibitor). Moreover, the activation of platelets by DENV NS1 promoted subthreshold concentrations of adenosine diphosphate (ADP)-induced platelet aggregation and enhanced platelet adhesion to endothelial cells and phagocytosis by macrophages. Finally, we demonstrated that DENV-induced thrombocytopenia and hemorrhage were attenuated in TLR4 knockout and wild-type mice when NS1 was depleted from DENV supernatant. Taken together, these results suggest that the binding of DENV NS1 to TLR4 on platelets can trigger its activation, which may contribute to thrombocytopenia and hemorrhage during dengue infection.

Over the past 50 years, dengue has been a continuing global threat, with no effective vaccine or specific antiviral drug. Dengue infection causes a wide range of outcomes, from fever-like symptoms to severe dengue hemorrhagic fever. Thrombocytopenia, a reduction in platelet count, is a common feature observed in both mild and severe dengue and is correlated with disease severity. In this study, we used dengue viral supernatant or DENV recombinant NS1 protein to stimulate human-isolated platelets. We found that DENV NS1 could directly activate platelets through TLR4 and could further enhance platelet aggregation, adhesion to endothelial cells and phagocytosis by macrophages, which could lead to thrombocytopenia. We also proved that both NS1 and TLR4 are critical for DENV-induced thrombocytopenia and hemorrhage using a DENV-induced hemorrhagic mouse model. Our study reveals a new pathogenic role of NS1 during dengue infection and highlights that NS1 should be a topic of attention in the development of therapeutic drugs and vaccines against dengue infection.

[Temporal expression of triggering receptors expressed by myeloid cells-1 during the development of experimental periodontitis in rat]

Objective: To illuminate the temporal expression of the triggering receptor expressed on myeloid cells-1 (TREM-1) in the experimental periodontitis in rat and to investigate the function of TREM-1 in the pathogenesis of experimental periodontitis in rat. Methods: The experimental periodontitis model was established in the maxillary first molar by means of 'wire ligation + vaccination periodontal pathogen Porphyromanus gingivalis (Pg) + high-sugar diet' in Sprague-Dawley (SD) rats. The experimental animals were divided into six groups: the control group and each of the time points of establishing the models for one week and two to five weeks. There were six rats for each of the six groups. The bone loss of the palatal site was calculated to estimate whether the periodontitis model was successfully established. The expression of TREM-1, proinflammatory cytokines: tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6, anti-inflammatory cytokines: IL-4, IL-10 and transforming growth factor-β (TGF-β) were examined by using quantitative real-time PCR. The expression level of TREM-1 protein was analyzed by the method of immunohistochemistry. Results: The average bone loss area of the palatal site was (0.17±0.04) mm(2) in the group of three weeks and was statistically significant (P<0.05) compared to the control group [(0.10±0.01) mm(2)]. The experimental periodontitis model was successfully established in the group of three weeks. The expression of TREM-1 increased significantly in the inflamed periodontal tissues and reached to its maximum expression in the three weeks group accounting for 159.50±38.26 in protein expression and 4.35±0.60 in mRNA expression, respectively. TREM-1 expression difference between the three weeks group and control group was statistically significant (P<0.01). The expression of IL-6 by gingival tissues was correlated with the mRNA level of TREM-1 (r=0.813 P=0.049). Conclusions: TREM-1, as a proinflammatory receptor, could facilitate the periodontal inflammatory response. The possible way of TREM-1 to promote inflammation may be through controling the expression of IL-6.

[A major histocompatibility complex class Ⅱ deficiency case report and literature review]

OBJECTIVE

To summarize and report the clinical characteristics and laboratory results of a case and those reported in literature with MHC class Ⅱ deficiency.

METHOD

The clinical features, laboratory results and gene mutation analysis of an infant with MHC class Ⅱ deficiency, who was diagnosed and treated in Peking Union Medical College Hospital since December 2013, were retrospectively analyzed."Major histocompatibility complex class Ⅱ deficiency"or"bare lymphocyte syndrome"were used as keywords in order to retrieve reports from CNKI (from its establishment to October 2015) and Wanfang Database (from its establishment to October 2015), PubMed Database (from its establishment to October 2015) was searched. The characteristics, diagnosis, treatment and prognosis were summarized by reviewing related articles.

RESULT

The patient was a 8-month-old boy. Since the fourth month of life, he started to have repeated fever, susceptible to a variety of pathogens, immune hemolytic anemia, severe malnutrition, and finally diagnosed as MHC class Ⅱ deficiency disease when he was 20-month-old.No related reports were retrieved from CNKI and Wanfang database, there were 20 articles and 179 patients were reported worldwide in the past 10 years. Patients exhibit an extreme vulnerability to infections(resptratory infection(82%, 146/178), inpection of gastroin testinal(76%, 135/178)). The common laboratory examinations showed hypogammaglobulinemia, CD4(+) lymphopenia(93%, 107/115) etc. Diagnosis relies on the flow-cytometric analysis and genetic analysis.

CONCLUSION

It is considered necessary for patients with young onset age, manifestation of clinically opportunistic infection as immune deficient disease, including the MHC class Ⅱ deficiency disease, especially long-term diarrhea, poor development and cryptosporidium infection. This disease could coexist with autoimmune disorders.

Increased expression of triggering receptor expressed on myeloid cells 1 and 2 in inflamed human gingiva

BACKGROUND AND OBJECTIVE

Periodontitis is an infectious disease in which the host immune and inflammatory responses play essential roles in resistance to bacterial infection, as well as the induction of tissue destruction if the immune response is dysregulated. The triggering receptor expressed on myeloid cells (TREMs) modulates inflammatory and innate immune signaling. TREM-1 is considered as an amplifier of the immune response, while TREM-2 is a negative regulator that has yet to be explored in periodontal disease before. We hypothesized that TREMs participated in the innate immune responses during the pathogenesis of periodontitis. Therefore, the aim of this study was to evaluate TREM-1 and TREM-2 expression in the gingival tissues from patients with chronic periodontitis and healthy subjects as well as their correlation with clinical periodontal parameters. This study is the first to identify TREM-2 in periodontal tissue, as well as the protein expression changes of TREM-1 and TREM-2 in periodontal tissues.

MATERIAL AND METHODS

Gingival tissue sections were collected from 31 healthy subjects and 53 patients with chronic periodontitis. Immunohistochemistry and quantitative real-time polymerase chain reaction were employed to evaluate the protein and mRNA expression of these receptors in gingival tissues. The recorded clinical parameters were probing depth, clinical attachment loss, plaque index and bleeding on probing.

RESULTS

In addition to myeloid cells in gingival connective tissues, TREM-1 and TREM-2 were also found expressed in gingival epithelial cells. In particular, TREM-1 was detected in almost all gingival epithelium from both healthy and inflamed biopsies. The expression levels of TREM-1 and TREM-2 were significantly increased in the periodontitis group compared to the healthy group. Increased levels of these receptors are to be positively correlated with site-specific periodontal parameters.

CONCLUSION

The increased expression of TREM-1 and TREM-2 levels in periodontitis may confer diagnostic and potential therapeutic targets as well as indicating their association with the clinical severity of the disease.

Chronic Finger Joint Instability Reconstructed With Bone–Ligament–Bone Graft from the Iliac Crest

Five patients with chronic instability of digital joints presented with instability and functional disability. Two patients had ulnar collateral ligament damage of the thumb metacarpophalangeal joint and another had chronic multidirectional instability due to radial collateral ligament, dorsal capsule and palmar plate laxity of the metacarpophalangeal joint of the thumb. The fourth patient had a lax radial collateral ligament and palmar plate of the proximal interphalangeal joint of the little finger and the fifth had chronic laxity of the ulnar collateral ligament of the interphalangeal joint of the thumb. All were reconstructed with bone–ligament–bone graft harvested from the iliac crest. The graft was fixed with screws and joint stability was achieved intra-operatively in all patients. All patients achieved a stable joint with improved functional performance at final followup.

Carpal Ligament Injuries with Acute Scaphoid Fractures – A Combined Wrist Injury

Fifty-two consecutive patients with acute scaphoid fractures were treated by closed reduction and percutaneous screw fixation. In addition, all underwent a wrist arthrogram and 22 patients also underwent a wrist arthroscopy. Eighteen patients (34%) had an associated carpal ligament injury (four scapholunate ligament, eight lunotriquetral ligament, two combined, three TFCC and one minor leak from the distal carpal row). These patients had worse Mayo wrist scores (no ligament injury median score = 95: ligament injury median score = 85) at a mean final follow-up of 61 weeks. We advocate that scaphoid fractures with associated carpal ligament injuries should be defined as a combined wrist injury.

Role of mechanical strain and estrogen in modulating osteogenic differentiation of mesenchymal stem cells (MSCs) from normal and ovariectomized rats

Bone's adaptability to loading depends upon the process of bone remodeling. This adaptive mechanism is restricted in postmenopausal osteoporosis. Differentiation of mesenchymal stem cells (MSCs) is crucial to bone remodeling and regeneration. It is well accepted that mechanical loading influences the fate of MSC differentiation. The aim of this study was to explore the possible restricted mechanism in osteoporotic condition, through investigating response of MSCs from both sham-operated and ovariectomized rats. MSCs were exposed to estrogen and mechanical strain (2%, 1Hz, 6h/day) for 3 days. Osteogenic differentiation and β-catenin protein in MSCs were examined. Exposure to estrogen and mechanical strain alone enhanced expression of Runx2 (Cbfα1), type I collagen (ColI) and activated β-catenin protein in MSCs from both sham-operated and OVX rats. MSCs from both sham-operated and OVX rats stimulated with both mechanical strain and estrogen had higher expression of osteogenic genes and activated β-catenin protein than these cells exposed to estrogen and mechanical strain alone. Osteoporotic MSCs had lower expression of osteogenic genes and protein in the absence and presence of stimulation than did MSCs from sham-operated rats. Cumulatively, our results indicate that mechanical strain and estrogen in vitro enhance osteogenic potential and activation of β-catenin in MSCs from both sham-operated and OVX rats. Estrogen augments strain-induced osteogenic potential and activity of β-catenin in MSCs.

Possible s±-wave pairing evidenced by midgap surface bound states in Fe-pnictide superconductors

A phenomenological theory of tunneling spectroscopy for Fe-pnictide superconductors is developed by taking into consideration asymmetric interface scattering between particle and holes. It is shown that, consistent with anti-phase s(±)-wave pairing, appreciable zero-energy surface bound states exist on the [100] surface of Fe-pnictide superconductors. However, in contrast to the [110] bound states in d-wave cuprate superconductors, these bound states arise as a result of non-conservation of momentum perpendicular to the interface for tunneling electrons and the s(±) pairing, and hence they can only exist in a small window (~ ± 6°) in the orientation of edges near the [100] direction. Our results explain why a zero-bias conductance peak is often observed in tunneling spectroscopy and why, when it disappears, two coherent peaks show up. These results provide unambiguous signals to test for possible s(±)-wave pairing in Fe-pnictide superconductors.

Genetic variability in copper-transporting P-type adenosine triphosphatase (ATP7B) is associated with Alzheimer's disease in a Chinese population

Previous experiments demonstrated that transgenic mice carrying both amyloid precursor protein and mutant ATP7B transgenes reduce amyloid plaques and diminish plasma Abeta levels. These experiments showed that a structural change of ATP7B may affect Alzheimer’s disease (AD) susceptibility. In this study three missense SNPs in ATP7B gene (rs1801243, rs1801244, and rs1801249) were chosen to test whether they were associated with AD. We tested this hypothesis using a case control design. The experimental data showed that there was a significant deviation from Hardy-Weinberg equilibrium (HWE) for SNP rs1801249 (c.3419 T greater than C, Val1140Ala) in the case group (p = 0.014) but not in the control group and that there was an association between SNP rs1801249 and AD under a recessive model (p = 0.003). The data also showed that the genotype frequency distribution of the ATP7B c.1366 G greater than C polymorphism (rs1801244, Val456Leu) differed significantly between the AD patients and the normal subjects (p = 0.012). In addition, the frequency of the TGC haplotype of SNPs rs1801243, rs1801244, and rs1801249 was significantly higher in the AD patients compared with the normal subjects (p = 8.49×10-7). These observations suggested that genetic variations in the copper transporter gene ATP7B might contribute to AD pathogenesis in the Taiwanese population.

Interplay between periodicity and nonlinearity of indirect excitons in coupled quantum wells

Inspired by a recent experiment of localization-delocalization transition (LDT) of indirect excitons in lateral electrostatic lattices (Remeika et al 2009 Phys. Rev. Lett. 102 186803), we theoretically investigate the interplay between periodic potential and nonlinear interactions of indirect excitons in coupled quantum wells. It is shown that the model involving both attractive two-body and repulsive three-body interactions can lead to a natural account for the LDT of excitons across the lattice when reducing lattice amplitude or increasing particle density. In addition, the observations that the smooth component of the photoluminescent energy increases with increasing exciton density and that the exciton interaction energy is close to the lattice amplitude at the transition are also qualitatively explained. Our model provides an alternative way of understanding the underlying physics of the exciton dynamics in lattice potential wells.

Autologous osteochondral graft for traumatic defects of finger joints

Finger joint defects in 16 adults were treated with an autologous osteochondral graft from the base of the second metacarpal, the radial styloid, the base of the third metacarpal or the trapezoid and these patients were followed up from between 12 and 62 months. There was no donor site morbidity. One patient had resorption of the graft and developed pain. The joint was subsequently fused. The mean range of movement was 55.8% of the opposite normal joint. At follow up, 15 patients had no discomfort or mild discomfort. Three had mild narrowing of the joint space and two had slight joint subluxation. Only two patients with concomitant severe injury to the same limb had difficulty performing daily activities. Ten were open injuries and these had poorer outcomes. A hemicondylar defect of a finger joint can be treated using an osteochondral graft obtained from the same hand.

Association between red blood cell distribution width and macrovascular and microvascular complications in diabetes

AIMS/HYPOTHESIS

Red blood cell distribution width (RDW) has been reported to be a risk marker of morbidity and mortality for cardiovascular disease in various study populations. However, no studies have investigated the relationship between RDW and diabetes complications. We therefore evaluated RDW as a marker of macrovascular and microvascular complications in a nationally representative sample of the adult diabetes population in the USA.

METHODS

A cross-sectional study was performed using the nationwide 1988 to 1994 data set from the Third National Health and Nutrition Examination Survey. The association between RDW quartiles and macrovascular and microvascular complications was evaluated in 2,497 non-pregnant adults aged 20 years and older and affected by diabetes. Logistic regression modelling was used to adjust for potential confounding.

RESULTS

Compared with the lowest RDW quartile, higher RDW values (3rd and 4th quartiles) were associated with increased adjusted odds of any vascular complication (OR 4th quartile 2.06 [95% CI 1.11, 3.83]), myocardial infarction (OR 4th quartile 2.45 [95% CI 1.13, 5.28]), heart failure (OR 4th quartile 4.40 [95% CI 1.99, 9.72]), stroke (OR 4th quartile 2.56 [95% CI 1.21, 5.42]) and nephropathy (OR 4th quartile 2.33 [95% CI 1.42, 3.82]). The odds of developing diabetic retinopathy were not significantly increased across RDW quartiles.

CONCLUSIONS/INTERPRETATION

Higher RDW values are associated with increased odds of developing cardiovascular disease and nephropathy in a nationally representative sample of USA adults with diabetes. RDW may be an important clinical marker of vascular complications in diabetes and one that is independent of traditional risk factors and disease duration.

Normal-sized ovarian papillary serous carcinoma: a case report

A normal-sized ovarian papillary serous carcinoma is rare. We present the case of a 46-year-old woman with progressive abdominal fullness of one week's duration. The medical evaluation revealed abdominal carcinomatosis with normal-sized ovaries and an elevated serum CA-125 level of 147,365.8 U/ml. Cytoreductive surgery (hysterectomy, bilateral salpingo-oophorectomy, omentectomy, lymphadenectomy, infracolic omentectomy, peritoneal biopsy, washing cytology, and appendectomy) was performed. The histologic examination revealed an ovarian serous papillary carcinoma. Adjuvant chemotherapy was administered. The serum CA-125 level decreased after completion of treatment. Normal-sized ovarian serous surface papillary carcinomas should be kept in mind as an origin of disease in patients who have peritoneal carcinomatosis, which sometimes is a diagnostic dilemma of the disease source. We report this case to emphasize the clinical symptoms and importance of the early and accurate diagnosis of a normal-sized ovarian papillary serous carcinoma.

The association of clinical findings and exposure profiles with melamine associated nephrolithiasis

BACKGROUND

Little is known about the exposure profiles of melamine in children. We evaluated the association of clinical findings, exposure patterns and biomarkers with nephrolithiasis in children with potential exposure to melamine.

METHODS

A case-control study was conducted in children aged 0-16 years with potential exposure to contaminated dairy products. Cases were defined as nephrolithiasis detected by renal ultrasonography. On the basis of different brands of contaminated dairy products consumed, subjects were classified into high exposure, low exposure and control groups with estimated melamine exposure levels of higher than 2.5 ppm, 0.05-2.5 ppm and lower than detection limits <0.05 ppm. We measured urine melamine for those with nephrolithiasis and age-matched and gender-matched controls within the subset of the study population.

RESULTS

The duration of consumption of contaminated products was longer in children with nephrolithiasis in the high exposure group than in controls (median (IQR) 12.0 (3.3-24.0) vs 6.0 (4.0-7.0) months; p = 0.048). High melamine exposure levels were significantly associated with nephrolithiasis (OR 61.04 (95% CI 12.73 to 292.84)). The risk was found to increase with estimate melamine exposure levels (p for trend <0.001). Two among 10 affected subjects with nephrolithiasis showed elevated urine melamine levels. In comparison, levels of all 20 controls were lower than the detection limit.

CONCLUSIONS

The risk of melamine-associated nephrolithiasis was related to duration of consumption of contaminated products and estimated melamine exposure levels. Though urine melamine was not a sensitive test, it might serve as an exposure biomarker in melamine-associated nephrolithiasis.

A study on the influence of breathing phases in intensity-modulated radiotherapy of lung tumours using four-dimensional CT

During gated intensity-modulated radiotherapy (IMRT) treatment for patients with inoperable non-small cell lung cancer (NSCLC), the end-expiration (EE) phase of respiratory is more stable, whereas end-inspiration (EI) spares more normal lung tissue. This study compared the relative plan quality based on dosimetric and biological indices of the planning target volume (PTV) and organs at risk (OARs) between EI and EE in gated IMRT. 16 Stage I NSCLC patients, who were scanned by four-dimensional CT, were recruited and re-planned. An IMRT plan of a prescription dose of 60 Gy per respiratory phase was computed using the iPlan treatment planning system. The heart, spinal cord, both lungs and PTV were outlined. The tumour control probability for the PTV and normal tissue complication probability for all OARs in the EE and EI phases were nearly the same; only the normal tissue complication probability of the heart in EE was slightly lower. Conversely, the conformation number of the PTV, V20 of the left lung, V30 of both lungs, Dmax of the heart and spinal cord, V10 of the heart and D5% of the spinal cord were better in EE, whereas D(mean) of the PTV, V20 of the right lung and maximum doses of both lungs were better in EI. No differences reached statistical significance (p<0.05) except Dmax of the spinal cord (p=0.033). Overall, there was no expected clinical impact between EI and EE in the study. However, based on the practicality factor, EI is recommended for patients who can perform breath-hold; otherwise, EE is recommended.

Malignant transformation of extragonadal endometriosis: a case report

Though malignant transformation of endometriosis has been documented, malignancy arising from extragonadal endometriosis is rare. We present the case of a 39-year-old woman with abdominal pain and fullness after menstruation. Evaluation revealed a cul-de-sac mass and CA-125 level of 1048 U/ml. A hysterectomy, bilateral salpingo-oophorectomy, and omentectomy were performed. Endometrioid adenocarcinoma with a clearly defined transition zone from endometriosis to adenocarcinoma was noted histologically. Adjuvant chemotherapy and GnRH agonist treatment was administered. Serum CA-125 level was 1.51 U/ml 19 months after completion of treatment. Patients with endometriosis and elevated CA-125 levels should be managed aggressively and CA-125 levels monitored until they have normalized.

Neolysogenization of Xanthomonas campestris pv. citri infected with filamentous phage Cf16

All previously described filamentous bacteriophages are capable of persistent infection while their DNA replicates as an episome in the host cell. Filamentous phage Cf16 undergoes an infectious cycle different from other filamentous phages reported heretofore. Upon initial infection with Cf16, infective centers are formed, each of which produces a large number of phage particles. As the infectious cycle progresses, the phage particles released and infective centers formed per carrier cell decrease with time. Finally, the Cf16 enters a "prophage" state, in which the carrier cell becomes lysogenic containing only one complete phage genome in an integrated form. One out of 10(3)-10(6) lysogenic cells can develop spontaneously into an infective center, which releases only one to two phage particles per cell in stationary phase culture. After infection, the Cf16 genome integrates into the host chromosome and replicates as a part of it. Free RF (replicative form) coexists with the integrated form and replicates independently from host chromosome. Upon further division, carrier cells eliminate the free RF at each succeeding generation. When Cf16 reaches the "prophage" state, only the integrated phage genome remains in the carrier cell with no detectable free RF.

Spontaneous fractures in nursing home residents

OBJECTIVES

To evaluate spontaneous long bone fractures occurring in nursing home residents and to identify what factors put them at risk for fractures.

DESIGN

Retrospective study.

SETTING

Department of Orthopaedics and Traumatology of a pubic hospital in Hong Kong.

PATIENTS

A total of 30 nursing home residents who developed spontaneous long bone fractures between 1994 and 2005 were reviewed.

MAIN OUTCOME MEASURES

Demographic data, mechanism of injury, pattern of fractures, associated risk factors, complications, outcomes, and post-treatment status.

RESULTS

The mean age of patients was 84 years. Co-morbidities were as follows: 22 patients were bedridden, 21 required long-term feeding by Ryle's tube, 19 had a history of cerebrovascular accident and 18 of whom had a long bone fracture on the side of the hemiplegia, 15 had dementia, and 25 had lower limb contractures. Closed supracondylar fractures of the femur occurred in 23 patients, 17 of whom presented with limb deformity. In 21 patients, fractures were treated successfully with hinged braces. In one patient, the fracture changed from closed to open. In five patients, the fractures were complicated by sacrum or heel sores, and in one by infected nonunion. In 28 patients, the fractures eventually healed without further complications. Three formerly bedridden patients were able to sit after their fractures had been treated.

CONCLUSIONS

Female nursing home residents who require long-term Ryle's tube feeding, have dementia, hemiplegia, lower limb contractures, osteoporosis, or are bedridden, are at high risk for spontaneous fractures.

Oncogenic osteomalacia associated with an occult phosphaturic mesenchymal tumour: clinico-radiologico-pathological correlation and ultrastructural studies

A middle-aged man presented with bone pain at multiple sites due to tumour-induced osteomalacia. The underlying occult phosphaturic mesenchymal tumour was identified by octreotide scan 5 years after presentation and confirmed by computed tomography. Tumour resection resulted in normalisation of blood chemistry and bone densitometry. Clinico-radiologico-pathological correlation and ultrastructural studies of the tumour threw light on the pathogenesis and pathophysiology of this rare disease.

High-pressure injection injuries of the hand in a Chinese population

We performed a retrospective review of 28 digits in 28 patients who suffered high-pressure injection injuries of the hand during the last 10 years. They were all men, with a mean age of 36 years. All were work injury and the injuries were classified into mild, moderate and severe and were either treated conservatively or surgically. There were seven patients with mild injuries and six of these were successfully treated by conservative methods. Sixteen patients had moderate injuries and all were successfully treated with repeated debridement and delayed direct closure. The index fingers of two severely injured patients were salvaged with digital artery flaps and the remainder of the involved fingers were amputated. The authors advocate proper identification of mild injuries to allow conservative treatment, the application of digital artery flaps for resurfacing large finger defects and have formulated a treatment protocol according to the severity of the injury.

Squamous cell carcinoma of the nail bed: three case reports

Squamous cell carcinoma of the nail bed is rare, and the disease is often misdiagnosed as a benign condition. Digital amputation is often performed because of the delay in diagnosis and the involvement of the distal phalanx. Between March 1999 and March 2002, 3 patients presented to the Pamela Youde Nethersole Eastern Hospital, Hong Kong, with squamous cell carcinoma of the nail bed. Two of the patients underwent a digit-salvaging procedure-namely, wide local excision and flap coverage-and their functional outcome was satisfactory. The remaining patient received partial amputation of the thumb without significant functional loss. A high degree of suspicion is thus needed to detect squamous cell carcinoma of the nail bed; a biopsy of chronic recurrent nail bed lesions should be performed.

Natural history and pathogenesis of the patella clunk syndrome

INTRODUCTION

The current study aims to test the importance of the design of total knee prostheses in the 'patella clunk syndrome', which is one of the possible patellofemoral complications that can occur after total knee replacement.

MATERIALS AND METHODS

Three patient cohorts consisting of 75 consecutive patients with 80 Insall-Burstein II (IB II) total knee replacements; 57 patients with 60 Anatomic Modular Knee (AMK) total knee replacements; and 103 patients with 106 Low Contact Stress Rotating Platform (LCS) total knee replacements were studied during the period from 1995 to 2001. This was an unselected series of elderly patients with knee arthritis of comparable demographics; we excluded only those patients receiving revision surgery. We recorded the preoperative and postoperative Knee Society scores, and the patient subgroups with postoperative patellofemoral complications were analysed in detail and were serially followed up. Radiological analysis followed the recommendation of the Knee Society, and the degree of pain was recorded on a visual analogue scale. Also, since the majority of patients with patella clunk syndrome had refused operation and were followed up for several years, an idea of the natural history of this condition was obtained.

RESULTS

The relative frequency of occurrence of patella clunk syndrome among patients with the IB II, AMK, and LCS prostheses was 8.8%, 3.3%, and 0%, respectively. The calculated p value is strongly significant when comparing the IB II group with the LCS group (p<0.01); and of borderline significance when comparing the AMK with the LCS group (p=0.05); and not statistically significant between the IB II and AMK groups (p=0.19). Analysis of the results also showed that about half of the patients who underwent conservative treatment still had incapacitating symptoms after several years of follow-up, while the other half showed progressive improvement over time.

CONCLUSION

Given a good surgical technique in component placement and debridement of the peripatella synovium, the design of a total knee prosthesis has a strong bearing on the incidence of the patella clunk syndrome. The natural history of the patella clunk syndrome reveals that for as yet uncertain reasons about 50% will improve with time even when given conservative treatment.

Effect of sonication on the electroless Ni-B deposited powder from acid bath

The electroless deposition rate of Ni-B powder increased with sonication (ultrasonic agitation). The boron content in deposited amorphous powder was about 2.2% with and without sonication. When Ni(II) ion was 20.0 mol/dm(3), deposition efficiency was 65% in 14 mmol/dm(3) dimethylamine boran (DMAB) and 90.2% of Ni(II) ion deposited over 33.9 mmol/dm(3) DMAB adding 100 mg/dm(3) powder. When DMAB ion was 1.7 times of Ni(II) ion, deposition efficiency was 90.2% over 20.0 mmol/dm(3) Ni(II) ion adding 100 mg/dm(3) powder. The optimum ratio of Ni(II) ion and DMAB concentration was 1:1.7. Deposition efficiency was larger about two times compared with that of the stationary state. The powder was amorphous. The particle form was spherical. Particle size of 0.75-1.25 microm was about 40%, and that of 1.25-1.75 microm was about 25%. Crystals of amorphous powder formed by heating from 573 to 773 K.

Multiple inflammatory pseudotumors of the spleen: case report

The imaging findings of multiple splenic inflammatory pseudotumors in a 45-year-old male are described. Peripheral ring enhancement on arterioportal phase and gradual enhancement from the periphery to the center on venous delay phase on contrast-enhanced dynamic magnetic resonance imaging were compatible with the pathologic findings. This result may aid in the preoperative diagnosis of these benign lesions.

Early results of posterior-stabilised NexGen Legacy total knee arthroplasty

OBJECTIVE

To retrospectively assess the early results of the NexGen Legacy posterior-stabilised total knee prosthesis, which is a newer version of the Insall-Burstein II posterior-stabilised implant.

METHODS

48 consecutive elderly patients had 60 NexGen Legacy posterior-stabilised total knees. The mean follow-up duration was 21 months. Clinical evaluation was performed according to the Knee Society scores and a scoring system for patellofemoral articulation; radiographic assessment followed the guidelines of the Knee Society. Special emphasis was given to any patellofemoral complications, such as patellar clunk syndrome, patellar maltracking, and other disorders of the extensor mechanism.

RESULTS

Only one patient had mild patellofemoral anterior knee pain at the latest follow-up; 2 patients had patellofemoral crepitus but no pain. No patellar clunk or any other complication of the patellofemoral articulation, such as patellar fracture or subluxation was found. The mean preoperative and postoperative Knee Society scores were 60 and 85 respectively. The mean postoperative knee flexion was 115 degrees.

CONCLUSION

The overall early results from using the new implant were good, probably because of changes in design of the intercondylar box and its associated cam-and-post mechanism, and a more anatomic trochlea surface, so that the trochlea accommodates the natural patella.

Deep venous thrombosis after total hip or knee arthroplasty in a "low-risk" Chinese population

Scarcely any information has been published on deep vein thrombosis (DVT) in Chinese patients after total hip arthroplasty (THA) or total knee arthroplasty (TKA). However, generally, no prophylaxis is given to patients who do not have conventional high-risk factors because they are believed to be at "low risk." We performed a prospective study on 80 such "low risk" patients undergoing THA or TKA (58 TKA and 22 THA) without prophylaxis and performed duplex ultrasonography on both lower limbs 6 to 8 days after surgery. A total of 22 patients (27.5%) showed ultrasonographic evidence of DVT. Eighteen (31%) TKAs and 4 (18.1%) THAs were complicated by DVT. Three patients showed bilateral involvement, all of whom underwent TKA. Two patients had symptomatic pulmonary embolism. The sensitivity and positive predictive value of the clinical examination was 27.2% and 31.6%, respectively. This study showed that patients who are labeled "low risk" for DVT actually had a significant risk and suggests that the current practice of providing prophylaxis to only patients deemed at "high risk" should be revised.

Venous thromboembolism in the Chinese population--experience in a regional hospital in Hong Kong

OBJECTIVE

To estimate the incidence and determine the characteristic features of venous thromboembolism in the Hong Kong Chinese population.

DESIGN

Retrospective study.

SETTING

Regional hospital, Hong Kong.

SUBJECTS AND METHODS

Data were collected during a period of four years (1997-2000). Patients with duplex doppler ultrasonography or venography-documented venous thromboembolism and new episodes of deep vein thrombosis were identified from Department of Diagnostic Radiology records. Patients with high-probability ventilation-perfusion scans were identified from Department of Nuclear Medicine records and these scans were taken as evidence of pulmonary embolism. Patients with intermediate-probability ventilation-perfusion scans, with pulmonary embolism documented by either pulmonary angiography or spiral computed tomography scan, were also included in the study. Patients with autopsy-verified fatal pulmonary embolism were identified from Department of Pathology records. Patients with deep vein thrombosis at other sites were sought from patient discharge diagnostic coding data. Medical records were reviewed for patient characteristics and conditions associated with the development of venous thromboembolism.

RESULTS

Three hundred and seventy-six Chinese patients had venous thromboembolism during the study period. Of these, 352 had peripheral deep vein thrombosis, five had deep vein thrombosis at other sites (cerebral sinus and portal vein thrombosis), 40 had pulmonary embolism (26 had concomitant deep vein thrombosis), and six had fatal pulmonary embolism shown at autopsy.

CONCLUSION

The calculated annual incidence of venous thromboembolism in Hong Kong Chinese people was estimated at 16.6 events per 100,000 population, which is lower than incidence rates reported in Caucasians. The four conditions most commonly associated with venous thromboembolism were medical illness, malignancy, orthopaedic surgery, and intravenous drug use. Conditions associated with venous thromboembolism in patients younger than 45 years included intravenous drug use, thrombophilia, pregnancy, and the use of oral contraceptives.

Percutaneous cannulated screw fixation of acute scaphoid waist fracture

This prospective study assessed the outcome of percutaneous cannulated screw fixation in 49 of 60 acute scaphoid fractures. The union rate was 100% (mean time for radiological union at 12 weeks). There were no early or mid-term complications and all achieved an excellent functional recovery.

Comparison of two total knee prostheses on the incidence of patella clunk syndrome

The patella clunk syndrome is not an uncommon complication, particularly after posterior-stabilized (PS) total knee arthroplasty. The present study was a consecutive unselected series comparing the incidence of the patella clunk syndrome amongst two comparable groups of elderly patients with knee arthritis implanted with the Insall-Burstein (IB II) total knee system and the newer NexGen Legacy total knee prosthesis. While 7.5% of patients in the PS IB II group developed patella clunk syndrome, none occurred in the NexGen group (P=0.05). We believe the difference is due mainly to a change in the design of the prosthesis, especially the more posterior intercondylar box and femoral cam of the NexGen femoral component.

Nitric oxide reduces blood pressure in the nucleus tractus solitarius: a real time electrochemical study

Increasing evidence has demonstrated that nitric oxide (NO) is involved in central cardiovascular regulation. In this study, we directly measured extracellular NO levels, in real-time, in the nucleus tractus solitarius (NTS) of anesthetized cats using Nafion/Porphyrine/o-Phenylenediamine-coated NO sensors. We found that local application of L-arginine (L-Arg) induced NO overflow in NTS and hypotension. These responses were potentiated in the vagotomized animals. Pretreatment with NO synthase (NOS)/guanylate cyclase inhibitor methylene blue, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one or NO scavenger hemoglobin attenuated L-Arg-induced hypotension, suggesting that exogenous supplement of NO suppressed cardiac functions through the NOS/cyclic guanosine monophosphate mechanism. The role of endogenous NO was examined after local application of N(G)-nitro-L-arginine methyl ester (L-NAME). We found that L-NAME suppressed endogenous NO levels in NTS and elicited hypertension and tachycardia. Taken together, our data suggest that NO is tonically released in the NTS to inhibit blood pressure.

Fish allergy in atopic children

The prevalence of fish allergy among 11 atopic children with elevated levels of specific immunoglobulin (Ig) E for cod was determined. None of the children had a history of fish allergy. All of the children had asthma and allergic rhinitis and 5 of them had also atopic dermatitis. The children underwent allergy skin tests (codfish, tuna, catfish, salmon, flounder, and bass), specific IgE tests (salmon, trout, tuna, eel, and mackerel), and food challenge tests. Skin tests in cod-specific IgE-positive children were positive for codfish in 4 children, tuna in 2, catfish in 2, salmon in 6, flounder in one, and bass in 2. Three children had elevated specific IgE for salmon, 5 for trout, 8 for tuna, 4 for eel, and 4 for mackerel. Oral fish challenge with 10 g of fish did not result in positive reaction in any of the children. In conclusion, a positive food challenge test provided the only definitive confirmation of fish allergy, whereas positive allergy skin tests or positive specific IgE tests were less reliable. Skin tests and in vitro specific IgE assays were not correlated with clinical symptoms of fish allergy, and the results of these 2 tests did not correlate with each other in this study.

[Ni(R2pipdt)2](BF4)2 (R2pipdt = 1,4-disubstituted-piperazine-3,2-dithione) as useful precursors of mixed-ligand dithiolenes of interest for non-linear optics

A simple method to obtain in high yields mixed-ligand nickel-dithiolene complexes, which show strong negative solvatochromism and negative first molecular hyperpolarizability, and the use of Raman spectroscopy to establish the extent of electronic delocalisation in these complexes, are reported.

Blood transfusion in elderly patients with acute myocardial infarction

BACKGROUND

Anemia may have adverse effects in patients with coronary artery disease. However, the benefit of blood transfusion in elderly patients with acute myocardial infarction and various degrees of anemia is uncertain.

METHODS

We conducted a retrospective study of data on 78,974 Medicare beneficiaries 65 years old or older who were hospitalized with acute myocardial infarction. Patients were categorized according to the hematocrit on admission (5.0 to 24.0 percent, 24.1 to 27.0 percent, 27.1 to 30.0 percent, 30.1 to 33.0 percent, 33.1 to 36.0 percent, 36.1 to 39.0 percent, or 39.1 to 48.0 percent), and data were evaluated to determine whether there was an association between the use of transfusion and 30-day mortality.

RESULTS

Patients with lower hematocrit values on admission had higher 30-day mortality rates. Blood transfusion was associated with a reduction in 30-day mortality among patients whose hematocrit on admission fell into the categories ranging from 5.0 to 24.0 percent (adjusted odds ratio, 0.22; 95 percent confidence interval, 0.11 to 0.45) to 30.1 to 33.0 percent (adjusted odds ratio, 0.69; 95 percent confidence interval, 0.53 to 0.89). It was not associated with a reduction in 30-day mortality among those whose hematocrit values fell in the higher ranges. In one of seven subgroup analyses (among patients who survived at least two days), transfusion was not associated with a reduction in mortality for patients with hematocrit values of 30.1 percent or higher.

CONCLUSIONS

Blood transfusion is associated with a lower short-term mortality rate among elderly patients with acute myocardial infarction if the hematocrit on admission is 30.0 percent or lower and may be effective in patients with a hematocrit as high as 33.0 percent on admission.

The effect of combined 5-fluorouracil and dexamethasone on cultured human retinal pigment epithelial cells

This study was designed to investigate the inhibitory effect of 5-fluorouracil (5-FU) and dexamethasone (DEX) on the proliferation of human retinal pigment epithelial (RPE) cells in vitro. The human RPE cells (R-50 cell line) were cultured and exposed to various concentrations of combined 5-FU (0, 250, 500, 1000, 2000 ng/ml) and DEX (0, 1, 10, 100, 200 micrograms/ml). The cells were incubated for 96 hr and the medium was changed every 48 hr to replenish the drug action. Cell viability was assessed using cell counting and trypan blue exclusion method. Tetrazolium salt, which can be metabolized by mitochondrial dehydrogenase to form a formazan dye, was used to assay cell proliferation. Treatment with 5-FU alone inhibited cell proliferation in a dose-dependent manner. The concentration of 5-FU that inhibited growth by 50% (IC50) was found to be 704.12 ng/ml. There was a bimodal effect of DEX on RPE cells--stimulation at low concentrations (1, 10 micrograms/ml) and inhibition at high concentrations (100, 200 micrograms/ml). When the two drugs were combined, there was additive inhibition in the concentration of 200 micrograms/ml of DEX. These results indicate that a combination of 5-FU and DEX is no more effective in the inhibition of human RPE cells, except in combination with high concentrations of DEX (> or = 200 micrograms/ml).

The nNOS/cGMP signal transducing system is involved in the cardiovascular responses induced by activation of NMDA receptors in the rostral ventrolateral medulla of cats

Nitric oxide (NO) is synthesized from L-arginine by NO synthase (NOS). NO stimulates the soluble form of guanylyl cyclase (sGC) and induces accumulation of cyclic guanosine monophosphate (cGMP). The purpose of this study was to examine whether the cardiovascular responses induced by N-methyl-D-aspartate (NMDA) in the rostral ventrolateral medulla (RVLM) depend on the actions of NOS and sGC. In anesthetized cats, the extracellular NO level was measured by in vivo voltammetry using a nafion/porphyrine/o-phenylenediamine-coated carbon-fiber electrode. Microinjection of NMDA into the RVLM produced hypertension and bradycardia associated with NO formation. These NMDA-induced responses were attenuated by prior injections of 7-nitroindazole, a neuronal NO synthase (nNOS) inhibitor, and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, a sGC inhibitor. These findings suggest that NO is involved in the NMDA-induced cardiovascular responses in the RVLM.

Suppression of choroidal neovascularization by adeno-associated virus vector expressing angiostatin

PURPOSE

To test the efficacy of a recombinant adeno-associated virus (rAAV) vector that expresses mouse angiostatin in suppressing experimental choroidal neovascularization (CNV) in a rat model.

METHODS

An rAAV vector, rAAV-angiostatin, was constructed to deliver the mouse angiostatin gene. rAAV-angiostatin and a control virus, rAAV-lacZ, were delivered in vivo by subretinal injection in Brown Norway rats, and the delivery was confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR). For a CNV suppression experiment, CNV was generated by fundus krypton laser photocoagulation 7 days after the viral vector injection and was evaluated by fluorescein angiography (FA) and histology. Apoptosis in retina was analyzed using the TUNEL assay. Inflammation in the retina was investigated by immunohistochemistry, using antibodies that recognize lymphocytes.

RESULTS

rAAV-angiostatin injection led to sustained expression of the angiostatin gene in chorioretinal tissue for up to150 days. FA analysis revealed significant reduction of the average sizes of CNV lesions in rAAV-angiostatin-injected eyes when compared with rAAV-lacZ-injected eyes at both 14 (P = 0.019) and 150 (P = 0.010) days after injection. Moreover, histologic analysis of CNV lesions also revealed significantly smaller lesions in rAAV-angiostatin-injected eyes (P = 0.004). As for adverse effects, rAAV-angiostatin injection did not cause inflammation or apoptosis of cells in retina and choroid.

CONCLUSIONS

This is the first report that subretinal injection of rAAV-angiostatin can significantly reduce the sizes of CNV lesions. This and the absence of apoptosis and inflammation in chorioretinal tissue indicate the feasibility of a gene therapy approach for treatment of CNV disease.

Quality of care among elderly patients hospitalized with unstable angina

BACKGROUND

Guidelines for the management of unstable angina have been published by the United States Agency for Health Care Policy and Research (currently known as the Agency for Healthcare Research and Quality); however, little information is available about the quality of unstable angina care, particularly among elderly patients.

METHODS

We examined 1196 elderly Medicare-insured patients hospitalized with unstable angina (ruled out for acute myocardial infarction) at Connecticut hospitals between August and November 1995 to evaluate quality of care provided during hospitalization. Patients without therapeutic contraindications were evaluated for the use of 5 Agency for Health Care Policy and Research guideline-recommended measures: electrocardiographic examination within 20 minutes of admission, use of aspirin on admission, intravenous heparin on admission, achievement of therapeutic anticoagulation among patients provided heparin, and prescription of aspirin on discharge.

RESULTS

Less than half (49.6%) of patients underwent electrocardiographic examination within 20 minutes of admission. After excluding patients with contraindications, aspirin was provided to 80.1% of patients and intravenous heparin to 59.2% of indicated patients, of whom only 43.3% achieved therapeutic anticoagulation. Aspirin was prescribed to 82.3% of eligible patients at discharge. Performance on the 5 quality measures varied widely among hospitals.

CONCLUSIONS

Agency for Health Care Policy and Research guideline-recommended risk stratification and therapeutic interventions are underused in elderly patients hospitalized with unstable angina, with quality of care varying widely among hospitals.

Management of postvitrectomy diabetic vitreous hemorrhage with tissue plasminogen activator (t-PA) and volume homeostatic fluid-fluid exchanger

The incidence of recurrent vitreous hemorrhage of proliferative diabetic retinopathy following posterior vitrectomy ranges from 29% to 75% in reported series. Fluid-gas exchange and vitreous cavity lavage are the popular methods of treating this kind of recurrent hemorrhage. The fluid-gas exchange cannot offer clear vision immediately after the procedure. To improve the function of the classic vitreous cavity lavage, we designed a volume homeostatic fluid-fluid exchanger - Chen's I/A device. Tissue plasminogen activator (t-PA) is a protease that preferentially converts fibrin-bound plasminogen to the active proteolytic enzyme, plasmin. It has been clinically and experimentally proven effective in lysis of postvitrectomy blood clot and fibrin formation. When the blood clot is formed in the vitreous cavity, intravitreal injection of t-PA can convert plasminogen to plasmin and remove the clot. From July 1999 to January 2000, ten eyes of postvitrectomy diabetic vitreous hemorrhage (PDVH) were collected. In each case, 4 days after intravitreal injection (IVI) of t-PA (30 microg), vitreous cavity lavage was performed with Chen's I/A device. Of these cases, 8 eyes (80%) experienced an immediate clearing of the vitreous cavity. Early complications included anterior hyaloid fibrovascular proliferation (2 eyes) and postoperative intraocular pressure elevation (3 eyes). On the basis of the results of this study, our conclusion is that volume homeostatic vitreous cavity lavage, combined with intravitreal injection of t-PA, is an excellent method for treatment of postvitrectomy diabetic vitreous hemorrhage but, in cases of PDVH with iris rubeosis, the advantage of this procedure is uncertain.

History of hand surgery in Hong Kong

The development of hand surgery in Hong Kong can be largely divided into three phases: the early years, the 1960s and 70s, and the present. In the immediate post-World War II years, incidence of infectious diseases was high; there were many patients with tuberculosis, poliomyelitis, leprosy and osteomyelitis. In the 1960s and 70s, the light industry revolution brought along many patients with serious hand injuries caused by machines. Dr Yen-Shui Tsao was the first local surgeon trained in hand surgery. Prof. SP Chow and Prof. PC Leung were the two pioneers who developed this subspecialty and microsurgery during that period.

At present, with the change in economic environment, the disease pattern has also changed. Despite our heavy clinical involvement, we have been very active in academic researches. The Hong Kong Society for Surgery of Hand was formed in 1986. For the past 15 years, the society organized Workshops and Annual Congresses attended by overseas speakers, including surgeons from China. It also provided scholarships for Fellows of the Asia-Pacific countries. In addition, the society provided the participants with the chance to exchange ideas and forge friendships. Hong Kong has thus been and will continue to be the meeting point of the East and the West.