Ecthyma gangrenosum: A case report in a child with acute lymphoblastic leukaemia

Aim

We present a case of Ecthyma gangrenosum (EG) affecting left thigh in a child with acute lymphoblastic leukaemia (ALL) with an aim to raise awareness about this condition.

Case presentation

A 7-year-old female child who presented with lethargy, pallor and lumps to inner lip was diagnosed with B-cell precursor ALL. She was started on treatment as per UKALL 2011 guidelines Regime B. On day 28, she developed neutropenic sepsis along with a new lesion in her left thigh. She was started on intravenous Meropenum, Gentamicin and Caspofungin. The clinical diagnosis of EG was made based on lesion progression, positive blood and wound swab & tissue cultures for Pseudomonas aeruginosa and patient's immunocompromised status. The wound healed with secondary intention following debridement. We present a series of photographs to demonstrate her remarkable improvement.

Discussion

EG occurs in 1-30% of cases of Pseudomonas sepsis; other bacteria and fungi can be associated with this condition. It is identified more in oncology patients as seen in our patient. A multidisciplinary team approach should be provided in 3 stages with empirical antibiotics, followed by targeted antibiotics or antifungals & surgical debridement. Our patient was treated in similar fashion and made a good recovery.

Conclusion

It is a rare skin condition associated with a high mortality. We suggest all clinicians to be vigilant about this condition to be able to provide accurate diagnosis and prompt treatment to improve the overall prognosis.

Spontaneous rupture of the right aortic sinus resulting in a sterile aorto-atrial fistula in a pet rabbit (Oryctolagus cuniculus)

Aortocardiac fistula is a broad term used to describe defects between the aorta and other cardiac chambers that can occur in humans and animals. A 1.5-year-old, 1.7 kg, male castrated Holland lop rabbit (Oryctolagus cuniculus) was presented for a two-week history of a heart murmur with corresponding cardiomegaly on radiographs. Physical examination confirmed a grade-V/VI continuous heart murmur on the right sternal border with a regular rhythm and a gallop sound. Echocardiography revealed an aortic-to-right-atrial fistula causing severe left-sided volume overload. Based on the echocardiographic findings, rupture of the right aortic sinus was suspected. Due to the poor prognosis, euthanasia was elected. On necropsy, a fistula was found connecting the right aortic sinus with the right atrium, without evidence of an inflammatory response nor evidence of an infectious etiology. The sudden onset of a heart murmur supported acquired fistulation from a ruptured aortic sinus (also known as the sinus of Valsalva), though a congenital malformation could not be completely excluded.

Routine four-quadrant cavity shaving at the time of wide local excision for breast cancer reduces re-excision rate

INTRODUCTION

Breast conservation therapy (BCT) has been shown to have comparable long-term survival outcomes when compared with mastectomy. Clearance of excision margin is one of the mainstays of the surgical treatment, which if not achieved at the first operation of BCT results in the need for subsequent surgery.

METHODS

This study evaluated the impact of routinely taken cavity shavings on re-excision rates. This retrospective two-centre study describes the use of routine four-quadrant cavity shaving in 449 patients with consecutively treated with wide local excision for invasive cancer or ductal carcinoma in situ.

RESULTS

The overall incomplete excision rate was 10.6%. Routine cavity shaving prevented the need for re-excision in 84 patients (18.7%) and identified the need for further re-excision in 33 patients (7.3%). Median time from surgery to radiotherapy was 50 days (range 13-209) for non-re-excised patients versus 78 days (range 47-260) for re-excised patients (p<0.001). Median time to chemotherapy (n=75) was 44 days (range 14-106) for non-re-excised patients versus 56 days (range 35-116) for re-excised patients (p=0.017).

CONCLUSIONS

This study demonstrates that routine cavity shaving decreases re-excision rate in patients treated with wide local excision and prevents delays to adjuvant treatment due to incomplete excision.

Autologous fat transplantation alters gene expression patterns related to inflammation and hypoxia in the irradiated human breast

BACKGROUND

Radiation-induced fibrosis, an adverse effect of breast cancer treatment, is associated with functional and cosmetic impairment as well as surgical complications. Clinical reports suggest improvement following autologous fat transplantation, but the mechanisms underlying this effect are unknown. A global gene expression analysis was undertaken to identify genetic pathways dysregulated by radiation and evaluate the impact of autologous fat transplantation on gene expression.

METHODS

Adipose tissue biopsies were taken synchronously from irradiated and contralateral non-irradiated breasts, before and 1 year after autologous fat transplantation. Whole-genome gene expression analyses were performed, and Hallmark gene set analysis used to explore the effect of radiotherapy and autologous fat transplantation on gene expression.

RESULTS

Forty microarrays were analysed, using bilateral biopsies taken from ten patients before and after autologous fat transplantation. Forty-five pathways were identified among the 3000 most dysregulated transcripts after radiotherapy in irradiated compared with non-irradiated breast (P ≤ 0·023; false discovery rate (FDR) no higher than 0·026). After autologous fat transplantation, 575 of the 3000 genes were again altered. Thirteen pathways (P ≤ 0·013; FDR 0·050 or less) were identified; the top two canonical pathways were interferon-γ response and hypoxia. Correlative immunohistochemistry showed increased macrophage recruitment in irradiated tissues.

CONCLUSION

The present findings contribute to understanding of how autologous fat transplantation can ameliorate radiation-induced fibrosis. This further supports the use of autologous fat transplantation in the treatment of radiation-induced fibrosis. Surgical relevance Clinical studies have indicated that autologous fat transplantation (AFT) stimulates regression of chronic inflammation and fibrosis caused by radiotherapy in skin and subcutaneous fat. However, there is a paucity of biological evidence and the underlying processes are poorly understood. Human data are scarce, whereas experimental studies have focused mainly either on the effect of irradiation or AFT alone. The present results indicate that radiotherapy causes dysregulated gene expression in fibrosis-related pathways in adipose tissues in humans. They also show that AFT can cause a reversal of this, with several dysregulated genes returning to nearly normal expression levels. The study provides biological evidence for the impact of AFT on radiation-induced dysregulated gene expression in humans. It supports the use of AFT in the treatment of radiation-induced fibrosis, associated with severe morbidity and surgical challenges.

A literature-based algorithm for the assessment, management, and monitoring of drug-induced QTc prolongation in the psychiatric population

BACKGROUND

Certain psychotropics and a number of other medications used to treat medical conditions in psychiatric patients can increase the risk of prolonging the corrected QT (QTc) interval on the electrocardiogram, which puts patients at risk of life-threatening ventricular arrhythmias such as torsades de pointes. Pharmacists are often consulted about medications which are known to prolong the QTc interval. Although this information is often accessible, advising how to identify, assess, manage, and refer psychiatric patients at risk for drug-induced QTc prolongation is more challenging.

OBJECTIVES

The objective of this project was first to review the literature, which describes guidelines and recommendations for the assessment and management of drug-induced QTc prolongation, and then to design an algorithm to be used by pharmacists working closely with mental health professionals or who provide care to psychiatric patients.

METHODS

A review of the literature was undertaken. Predefined keywords were used to perform the database search in MEDLINE, EMBASE, and International Pharmaceutical Abstracts to identify reviews, reports and guidelines on the assessment, prevention and monitoring of drug-induced QTc prolongation with an emphasis on psychotropic medications and management in the psychiatric population.

RESULTS

The electronic database search retrieved 637 relevant citations. These were initially screened by title and all duplicates were removed. The abstracts were then reviewed for relevancy based on the inclusion/exclusion criteria. Additional citations were retrieved from the bibliography of the articles identified in the initial search. A total of 79 articles describing QTc prolongation in the psychiatric population were thoroughly examined, but only 31 articles were selected to guide the development of the algorithm.

CONCLUSION

The literature-based algorithm developed provides a stepped-based approach for the assessment, monitoring, and management of drug-induced QTc prolongation in the psychiatric population. The algorithm may assist mental health clinicians in the decision-making process when psychiatric patients are prescribed medications known to increase the QTc interval.

Attitudes about Organ and Tissue Donation among the General Public and Blood Donors in Hong Kong

Context

The cadaveric organ and tissue donation rate in Hong Kong is not satisfactory; 1 million blood donors are registered and more than 300 000 are active. However, the current attitudes toward organ and tissue donation in the general public and blood donors of Hong Kong are unknown.

Methods

Random general public (n = 1018) and blood donors (n = 1227) of Chinese origin, with age ranging from 16 to 60 years, were interviewed using a standard verified questionnaire that examines attitudes and knowledge of organ and tissue donation.

Results

The mean age of the general public and blood donors were 32.6 and 28.9 years, respectively. Of the general public, 44.4% were men and among blood donors, 60% were men. About 56% of both groups thought that organ donation is an obligation of citizens. Blood donors were more aware than the general public about the types of organs that can be donated. When compared with the general public, a significantly higher percentage of blood donors were willing to donate their organs (81% vs 53%), had heard about organ donation cards (98.3% vs 89.5%), and had signed the cards (49.9% vs 22.6%). About 70% of both groups who had signed a card were carrying it. Thirty-nine percent of the general public and 17% of blood donors had not decided whether they would donate. For blood donors, 49.7% were willing to donate their relatives' organs, compared with 41.8% of the general public. Most individuals in both groups would not object to their relatives' decision to donate. About two thirds of individuals in both groups disagreed with the concept of an opt-out law, though only 20% of the general public and 14.4% of blood donors would refuse donation if an opt-out law were in practice.

Conclusions

This study shows that blood donors have better knowledge of organ donation and are more willing to donate their organs and sign an organ donation card than the general public. However, a substantial proportion of blood donors have not signed a donor card. It would be useful to design promotion programs to facilitate blood donors' participation in organ donation.

Level 5 Lymphadenopathy Warrants Heightened Suspicion for Clinically Significant Pathology

We conclude that patients presenting with level 5 lymphadenopathy should be investigated with heightened clinical vigilance. Our results suggest that up to 80 % will harbour clinically significant pathology requiring further medical treatment, three quarters of which will be malignancy. We report an observational study of histological outcomes of level 5 lymph node biopsies from a regional histopathology department across 5 years. 184 subjects were identified as having a biopsy of a lymph node from the level 5 region within the study period. One hundred and fifty six cases (84.8 %) had clinically significant pathology on final histology requiring further medical treatment. Lymphoma accounted for the highest number of cases (n = 72, 39.1 %), followed by metastatic carcinoma (n = 65, 35.3 %) and granulomatous change (n = 17, 9.2 %). Gender and laterality were not shown to be independent predictors of pathology significance (p > 0.05).

Osteogenic efficacy of bone marrow concentrate in rabbit maxillary sinus grafting

Maxillary sinus grafting is required to increase bone volume in the atrophic posterior maxilla to facilitate dental implant placement. Grafting with autogenous bone (AB) is ideal, but additional bone harvesting surgery is unpleasant. Alternatively, bone substitutes have been used but they limit new bone formation. The strategy of single-visit clinical stem cell therapy using bone marrow aspirate concentrate (BMAC) to facilitate new bone formation has been proposed. This study aimed to assess bone regeneration capacity of autologous BMAC mixed with bovine bone mineral (BBM) in maxillary sinus grafting. Twenty-four white New Zealand rabbits were used and their maxillary sinuses were randomly assigned for grafting with 4 different materials. Rates of new bone apposition in augmented sinuses were measured and bone histomorphometry were examined. Significant increase in the quantity of nucleated cells and colony forming unit-fibroblasts were confirmed in BMAC. Mesenchymal stem cells in BMAC retained their in vitro multi-differentiation capability. Higher rates of mineral appositions in the early period were detected in BBM + BMAC and AB than BBM alone, though they are not significantly different. Graft volume/tissue volumes in BBM and BBM + BMAC were found to be higher than those in AB and sham.

Ceramides are associated with inflammatory processes in human mediastinal adipose tissue

BACKGROUND AND AIM

Ceramides are poorly characterized in human adipose tissue. The aim of this study was to investigate concentrations of different ceramide species in human subcutaneous and visceral adipose tissue depots and to determine associations between ceramides and global gene expression profiles.

METHODS AND RESULTS

Concentrations of six ceramide species were determined in plasma and in subcutaneous and mediastinal adipose tissue from 10 overweight subjects (BMI 29.4 ± 4.9 kg/m(2)). In the adipose tissue biopsies gene expression arrays were performed and relationships between ceramides and gene expression analyzed. Immunostaining of the two adipose tissue depots was performed in an independent group of 10 patients. Mediastinal adipose tissue contained significantly higher concentrations (p < 0.05) of all six ceramide species than the subcutaneous depot. Of the six ceramides in plasma, concentrations of only two (Cer d18:1/18:0 and Cer d18:1/22:0) correlated significantly (p < 0.05) with the corresponding species in mediastinal adipose tissue, but there were no significant correlations between ceramides in plasma and subcutaneous adipose tissue. Multivariate analysis identified significant correlations between the total ceramide concentration and global gene expression within mediastinal, but not subcutaneous adipose tissue, according to cross-validation. Gene ontology analysis of genes related to ceramides in the mediastinal depot revealed that genes positively correlated with ceramides were associated mainly with immune and inflammatory categories, while genes negatively correlated with ceramides were associated mainly with lipid and carbohydrate metabolism.

CONCLUSIONS

Ceramides in human mediastinal adipose tissue may be involved in inflammation and lipid and carbohydrate metabolism.

Emergency management of dental trauma: knowledge of Hong Kong primary and secondary school teachers

OBJECTIVES. To investigate the level of knowledge about emergency management of dental trauma among Hong Kong primary and secondary school teachers. DESIGN. Questionnaire survey. SETTING. A teachers' union that unites 90% of teachers in Hong Kong. PARTICIPANTS. Randomly selected primary and secondary school teachers. RESULTS. Only 32.8% of respondents correctly stated that a person sustaining dental trauma should go to dentists directly. In all, 73.1% of teachers correctly stated that a dental trauma patient should go for treatment immediately. Only 32.5% knew that a fractured tooth should be put in liquid. Even fewer (23.2%) realised that the displaced tooth should be repositioned back to the original position. Relatively more respondents (74.7%) understood that an avulsed baby tooth should not be put back. Disappointingly, only 16.3% of teachers knew that an avulsed permanent tooth should be replanted. Furthermore, only 29.6% of teachers thought that they were able to distinguish between deciduous teeth and permanent teeth, whilst 20.4% correctly identified at least one of the appropriate mediums: milk, physiological saline or saliva, for storing an avulsed tooth. Teachers who previously received first-aid training with dental content or acquired dental injury information from other sources, scored significantly higher than teachers without such training or acquired information. CONCLUSION. The knowledge on emergency management of dental trauma among primary and secondary school teachers in Hong Kong is insufficient, particularly on the handling of permanent tooth avulsion and the appropriate storage medium for avulsed teeth. Receipt of first-aid training with dental contents and acquisition of dental injury information from other sources were positively correlated with knowledge in managing dental trauma.

Continuous on-line monitoring of secretion from rodent pituitary endocrine cells using fluorescent protein surrogate markers

We have developed a system to use secreted fluorescent proteins (FPs) as surrogate markers for the continuous on-line monitoring of hormone release from perfused tissue slices. We have tested this system using GH-GFP transgenic rats with green fluorescent protein (GFP) targeted to the secretory vesicles (SVs) of pituitary growth hormone (GH) cells. Brief exposures of vibratome slices to GH secretagogues [GH-releasing hormone (GHRH), GH-releasing peptide-6 (GHRP-6)] or somatostatin caused changes in FP output that correlate with hormone secretion, subsequently measured in fractions of perfusate by radioimmunoassay. The temporal resolution of this method was capable of revealing differences in the kinetics of response to GHRH and GHRP-6 between wild-type and dwarf (dw/dw) rats harbouring the GH-GFP transgene. We further tested the utility of the system by generating transgenic mice with red FPs targeted to secretory vesicles (PRL-mRFP(sv)) and to the cytoplasm (PRL-DsRed(cyto)) of lactotrophs. Dopamine had no effect on the FP output from pituitary slices of PRL-DsRed(cyto) mice but inhibited output from those of PRL-mRFP(sv) animals, with a rebound increase of release after removal, which again correlated with hormone output measured in the perfusate by radioimmunoassay. The inhibition of monomeric RFP secretion by dopamine was dose-dependent, as was stimulation by low concentrations of oxytocin. The temporal resolution afforded by this method provides useful insight into the release kinetics from large populations of pituitary cells, and fills a temporo-spatial gap between single vesicle and single cell monitoring of exocytosis in milliseconds, and in vivo sampling studies of release into the bloodstream on a time scale of minutes.

Risk factors of neurosensory deficits in lower third molar surgery: an literature review of prospective studies

This literature review assessed the risk factors linked to inferior dental nerve (IDN) and lingual nerve (LN) deficits following lower wisdom tooth surgery. A computer search of several databases with specified key words was performed. 32 articles were selected; the risk factors for IDN deficit were reported in 4 articles, LN in 9 and both IDN and LN in 19. Data were analysed statistically to evaluate the potential risk factors. Literature review showed specific radiographic signs and intra-operative IDN exposure increased the risk of IDN deficit. Raising the lingual flap significantly increased the risk of LN deficit. Unerupted tooth and lingual split technique increased IDN and LN deficit risks significantly. Age was linked to IDN and LN deficits, and deep impaction was related to IDN deficit, but no statistical tests were performed on these two risk factors owing to the heterogeneity of data from the studies. This literature review found increased age, unerupted tooth, deep impaction, specific radiographic signs, intra-operative IDN exposure and lingual split technique were risk factors for IDN deficit; increased age, unerupted tooth, distal impaction, raising of lingual flap and lingual split technique were risks factors for LN deficit in lower wisdom tooth surgery.

Maxillary distraction versus orthognathic surgery in cleft lip and palate patients: effects on speech and velopharyngeal function

This clinical randomized controlled trial was performed to compare the effects of distraction osteogenesis (DO) and conventional orthognathic surgery (CO) on velopharyngeal function and speech outcomes in cleft lip and palate (CLP) patients. Twenty-one CLP patients who required maxillary advancement ranging from 4 to 10 mm were recruited and randomly assigned to either CO or DO. Evaluation of resonance and nasal emission, nasoendoscopic velopharyngeal assessment and nasometry were performed preoperatively and at a minimum of two postoperative times: 3-8 months (mean 4 months) and 12-29 months (mean 17 months). Results showed no significant differences in speech and velopharyngeal function changes between the two groups. No correlation was found between the amount of advancement and the outcome measures. It was concluded that DO has no advantage over CO for the purpose of preventing velopharyngeal incompetence and speech disturbance in moderate cleft maxillary advancement.

Incidence of neurosensory deficits and recovery after lower third molar surgery: a prospective clinical study of 4338 cases

A prospective study of all lower third molar surgery performed in the outpatient extraction clinic of a teaching dental hospital was conducted from January 1998 through October 2005 to determine the incidence of subsequent neurosensory deficit due to inferior alveolar nerve (IAN) and lingual nerve (LN) injury, to examine possible contributing risk factors and to describe the pattern of recovery. 3595 patients were included (61% female, 39% male; age range, 14-82 years). Of the 4338 lower third molar extractions performed by various grades of operators, 0.35% developed IAN deficit and 0.69% developed LN deficit. Distoangular impaction was found to increase the risk of LN deficit significantly (p<0.001). Depth of impaction was related to the risk of IAN deficit (p<0.001). Undergraduates caused more LN deficits (p<0.001). Sex, age, raising of a lingual flap, protection of LN with a retractor, removal of distolingual cortex, tooth sectioning and difficulty in tooth elevation were not significantly related to IAN or LN injury. Postoperative recovery from IAN and LN deficits was noted most significantly at 3 and 6 months, respectively. By the end of the follow-up period, 67% of IAN deficits and 72% of LN deficits had recovered completely.

Three-dimensional ultrasound features of the polycystic ovary in Chinese women

OBJECTIVES

To quantify the three-dimensional (3D) ultrasound characteristics of ovaries in Chinese women with polycystic ovarian syndrome (PCOS) and to compare these with previous data on a Caucasian cohort with PCOS.

METHODS

3D pelvic ultrasound was performed in 40 Chinese women with PCOS and 40 controls. Ovarian volume, stromal volume and echogenicity, and antral follicle count (AFC) were measured and ovarian blood flow was quantified using both 3D power Doppler and two-dimensional (2D) pulsed wave Doppler. These data were compared with previously published data on a Caucasian cohort with PCOS.

RESULTS

Compared with controls, women with PCOS had a higher AFC (median (range), 15 (11-30) vs. 5.5 (1-10) per ovary, P < 0.01), ovarian volume (12.32 (8.10-16.16) mL vs. 5.64 (2.62-8.81) mL, P < 0.01) and stromal volume (9.74 (6.44-13.56) mL vs. 4.07 (1.52-6.67) mL, P < 0.01) but were comparable in stromal echogenicity and ovarian blood flow as measured by 3D power Doppler or 2D pulsed wave Doppler indices. However, in comparison with a previously reported Caucasian cohort with PCOS, the ovaries of Chinese women with PCOS had a significantly smaller stromal volume (median (range), 9.74 (6.44-13.56) mL vs. 10.79 (5.65-17.12) mL, P < 0.05), were less echogenic as reflected in a lower mean gray value (22.43 (13.13-35.50) vs. 32.36 (19.35-53.71), P < 0.01), and had reduced ovarian blood flow as reflected in a lower flow index (30.19 (23.32-44.88) vs. 33.54 (21.88-51.65), P < 0.05).

CONCLUSION

Based on 3D ultrasound measurements, Chinese women with PCOS have an increased stromal volume compared with controls. However, their stromal volume, echogenicity and vascularity is significantly lower than that in Caucasian women with PCOS. The possible etiology for these differences is discussed.

Distraction or orthognathic surgery for cleft lip and palate patients: which is better?

Maxillary deformities of cleft lip and palate (CLP) can be treated by either conventional osteotomies (CO) or distraction osteogenesis (DO). Which one is better for CLP patients suffering from a moderate extent of maxillary hypoplasia? The aim of the study was to evaluate the treatment outcomes of CO and compared with DO in correction of moderate maxillary hypoplasia. The results showed that CLP patients receiving DO were more anxious and depressed during the first three months but became happier in the long-term. The nasalance of DO and CO was found to be similar. However, on the skeletal stability, DO was shown to be significantly more stable when compared with CO in the horizontal plane within the first six months and in vertical plane during the first three months and between 1-2 year.

Influence of nicotine on blood perfusion and bone healing during distraction osteogenesis

Nicotine is the main chemical component in tobacco products and its effect on bone healing remains controversial. This study aims to evaluate the influence of nicotine on blood perfusion and bone healing using a rabbit model of mandibular distraction osteogenesis. The dose dependent effect of nicotine on bone regeneration, and the effect of nicotine on blood perfusion and angiogenesis were assessed by radiography, micro-computed tomography, histological and immunohistochemical analysis, real time PCR and Laser Doppler monitoring. Results showed that bone healing was compromised by high dose nicotine treatment. Nicotine exposure increased microvessel density, whereas inhibited blood flow and bone formation. The expression of bone morphogenetic protein (BMP)-2 in osteoblasts was also decreased. The present study supported that nicotine has a dose dependant influence on bone healing in distraction osteogenesis. Nicotine compromises bone regeneration possibly by causing ischemia and inhibiting BMP expression in osteoblasts. Nicotine exposure enhances angiogenesis but can not compensate for the adverse effect of vasoconstriction.

Quantitative evaluation of tissue invasion by wild type, hyphal and SAP mutants of Candida albicans, and non-albicans Candida species in reconstituted human oral epithelium

BACKGROUND

Oral candidiasis is a common problem in compromised patients. Although several non-albicans Candida species have emerged as pathogens the majority of candidal infections are caused by Candida albicans. Morphogenesis from the blastospore to filamentous phase, and production of secretory aspartyl proteinases (SAP) are two major virulence attributes of these opportunistic yeast. Histopathology of oral candidiasis is characterized by fungal invasion of the superficial epithelium although the invasive potentials of different Candida species vary. Computerized image analysis systems (IAS) utilizing immunohistochemistry have been successfully employed for quantification of such histopathological features. The purpose of this study was to evaluate quantitatively the in vitro invasive potential of C. albicans and its hyphal and SAP mutants, and five other non-albicans Candida species using a computerized IAS.

METHODS

In vitro human oral candidiasis was produced using five wild type and one reference C. albicans isolates, hyphal and SAP mutants of C. albicans SC 5314, and one wild type and one reference isolate each of C. tropicalis, C. dubliniensis, C. glabrata, C. parapsilosis and C. krusei in a reconstituted human oral epithelium (RHOE) model. The infected tissues were examined histologically at 12, 24 and 48 h. Invading fungal elements were visualized by periodic acid-Schiff (PAS) staining and quantitatively evaluated as a percentage of total tissue invasive area, using a computerized IAS.

RESULTS

All C. albicans isolates including hyphal mutant cph1/cph1 and SAP mutants; sap 1-3, sap 4-6 produced hyphae and differentially (P < 0.05) invaded the tissue over 48 h. The invasive potential of hyphal mutant cph1/cph1 and SAP mutants (sap 1-3, sap 4-6) were similar to the parent wild-type isolate at 12 h although after 24 h their invasion was dissimilar (P < 0.05). Non-albicans Candida species and hyphal mutants; efg1/efg1, efg1/efg1 cph1/cph1 were all non-invasive.

CONCLUSIONS

RHOE model in combination with computerized image analysis permits for the first time, the assessment of invasive potential of Candida species in a quantitative manner. The differential tissue invasive patterns of various C. albicans isolates, their mutants and other Candida species are also described.

A meta-analysis of cleft maxillary osteotomy and distraction osteogenesis

This meta-analysis aims to provide evidence-based data to assist surgeons to make an informed choice between distraction osteogenesis or conventional osteotomy for cleft lip and palate patients. A PUBMED search of the National Library of Medicine from 1966 to December 2003 was conducted. Keywords used in the search were 'cleft', 'distraction', 'maxilla', 'maxillary', 'advancement', 'osteotomy', and 'orthognathic surgery'. This study concluded that distraction osteogenesis tends to be preferred to conventional osteotomy for younger CLP patients with more severe deformities. In such cases it was feasible to use distraction to correct moderate to large movement of the maxilla by either complete or incomplete Le Fort I osteotomy, and a concurrent mandibular osteotomy was less frequently required. Intra-operative and post-operative complications were uncommon with either technique, and some of the traditional ischemic complications related to conventional osteotomy were replaced by infection of the oral mucosa due to the prolonged retention of the distractors. There is still no conclusive data on any differences in surgical relapse, velopharyngeal function and speech between the two techniques. Both distraction osteogenesis and conventional osteotomy can deliver a marked improvement in facial aesthetics.

Visible and near-infrared calibrations for quality assessment of fresh phase I and II mushroom (Agaricus bisporus) compost

Previous studies have shown that visible and near-infrared spectra (Vis-NIR) of dry and milled compost can be used for generating partial least squares (PLS) calibrations of phase II compost parameters including ammonia, nitrogen dry matter (NDM), dry matter (DM), pH, conductivity, carbon, microbial population, and potential productivity. The objective of this study was to develop robust calibrations for some of the key parameters from the spectra of fresh phase I and II composts. Samples of substrates from six commercial production yards were obtained during winter and summer months of 2000-2004 to monitor changes in quality and were analyzed for the test factors. Vis-NIR reflectance measurements of fresh samples (740) were made over the range of 400-2500 nm. After mathematical pretreatments, PLS calibrations of the key parameters were developed using the NIR (1100-2500 nm) and visible and NIR (400-2500 nm) regions and subsequently validated using an independent sample set of 123 phase I and II samples obtained during 2004-2005. The phase I and II standard errors of laboratory measurements of ammonia, pH, conductivity, DM, NDM, and ash were lower than the standard error of predictions of the same parameters, respectively, by the best NIR or Vis-NIR models. The degree of precision for some of the calibrations, especially ammonia, NDM, and DM, is suitable for composters to monitor changes in quality parameters during production. The laboratory measurement errors for phase I samples were greater than those of the phase II samples, except for ash, due to a higher degree of heterogeneity in the substrate. The calibrations, especially for pH, conductivity, and ash, need to be improved with new sample sets. A major advantage of NIR spectroscopy is the ability to assess substrate quality for a range of target parameters simultaneously, within a few hours of receiving the samples. The main drawbacks are the expensive instrumentation, expertise, and training necessary for operating the spectrometer and a dedicated chemometrician required for maintaining the equations compared to the reference methods.

A comparison of post-operative complications following wisdom tooth surgery performed with sterile or clean gloves

This randomised prospective study aimed at evaluating possible differences in the post-operative complication rate following lower wisdom tooth surgery performed with either sterile or clean surgical gloves. The microbiological profiles of the tooth sockets and glove surfaces were also evaluated and compared. A total of 275 ASA I, non-smoking and non-drinking patients consented to be randomly assigned into two groups for lower wisdom tooth surgery, performed by operators wearing either sterile or clean gloves. All the patients returned for a post-operative assessment visit one week later. An additional 40 patients were recruited and randomised into the sterile glove group (n = 20) or the clean glove group (n = 20) for the microbiology study. Specimens were taken from the glove surfaces and the post-operative socket wounds during wisdom tooth surgery. This clinical trial showed no significant difference between the sterile and clean glove groups in the incidence of acute inflammation, acute infection and dry sockets in the wounds. No single peri-operative factor had a statistically significant effect on post-operative pain intensity. Most of the bacterial isolates from the clean gloves were Gram-positive cocci or spore-forming bacilli. The total number of colony forming units and the variety of bacterial isolates from the socket wounds in the sterile and clean glove groups were similar. The study concluded that there was no advantage in using sterile surgical gloves rather than clean gloves to minimize post-operative complications in wisdom tooth surgery. There was also no apparent relationship between the bacteria contaminating the clean glove surfaces and those isolated from the socket wounds.

Active mobilisation after flexor tendon repair: comparison of results following injuries in zone 2 and other zones

PURPOSE

To prospectively study the role of active mobilisation after flexor tendon repair.

METHODS

The standard modified Kessler's technique was used to repair 46 digits in 32 patients with flexor tendon injuries. Early active mobilisation of the repaired digit was commenced on the third postoperative day. Range of movement was monitored and recovery from injury in zone 2 was compared with injury in other zones.

RESULTS

There were 24 and 22 injuries in zone 2 and other zones respectively. The total active motion score of the American Society for Surgery of the Hand was measured. Patients with zone-2 injuries achieved similar results to those with other-zone injuries apart from a 3-week delay in recovery. The final results were good to excellent in 71% and 77% of zone-2 and other-zone cases respectively (p < 0.05). There were 2 ruptures in zone-2 and one rupture in zone-3 repairs (6.5%).

CONCLUSION

Preliminary results of this study showed that active mobilisation following flexor tendon repair provides comparable clinical results and is as safe as conventional mobilisation programmes although recovery in patients with zone-2 injury was delayed.

TNF and TNFR polymorphisms in severe sepsis and septic shock: a prospective multicentre study

Tumour necrosis factor (TNF) is an important pro-inflammatory cytokine produced in sepsis. Studies examining the association of individual TNF single nucleotide polymorphisms with sepsis have produced conflicting results. This study investigated whether common polymorphisms of the TNF locus and the two receptor genes, TNFRSF1A and TNFRSF1B, influence circulating levels of encoded proteins, and whether individual polymorphisms or extended haplotypes of these genes are associated with susceptibility, severity of illness or outcome in adult patients with severe sepsis or septic shock. A total of 213 Caucasian patients were recruited from eight intensive care units (ICU) in the UK and Australia. Plasma levels of TNF (P = 0.02), sTNFRSF1A (P = 0.005) and sTNFRSF1B (P = 0.01) were significantly higher in those who died on ICU compared to those who survived. There was a positive correlation between increasing soluble receptor levels and organ dysfunction (increasing SOFA score) (sTNFRSF1A R = 0.51, P < 0.001; sTNFRSF1B R = 0.53, P < 0.001), and in particular with the degree of renal dysfunction. In this study, there were no significant associations between the selected candidate TNF or TNF receptor polymorphisms, or their haplotypes, and susceptibility to sepsis, illness severity or outcome. The influence of polymorphisms of the TNF locus on susceptibility to, and outcome from sepsis remains uncertain.

Reconstruction of maxillectomy defect by transport distraction osteogenesis

The study aimed to explore the feasibility of posterior maxillectomy reconstruction by transport distraction in a primate model. In each of 14 male adult rhesus monkeys, posterior partial maxillectomy was performed on one side of maxilla to create a posterior maxillary deflect. Immediately after the maxillectomy, a dentoalveolar segment anterior to the defect was osteotomized as transport segment and a custom-made transport distractor was fixed on the residual maxilla. After a latency period of 5 days, the distractor was activated 1 mm daily to move the transport segment backward to the defect. This process lasted about 2 weeks. The transport segment was allowed to consolidate and the animals were sacrificed at different defined intervals. Transport distraction was successful in six animals. Three other cases were completed with minor wound dehiscence and one had a small oro-antral fistula with subsequent maxillary sinusitis. New bone bridging the distraction gap was confirmed by radiography and histology in the animals completing distraction. Reconstruction of posterior maxillectomy defect is proven feasible by transport distraction osteogenesis.

The effects of tobacco use on oral health

OBJECTIVE

To review the effects of tobacco use on oral health, with particular emphasis on the effects of periodontal diseases, dental implant failures, and risk of development of oral cancers and precancers.

DATA SOURCES

Medline literature search (1977-2002).

STUDY SELECTION

Key words for the literature search were 'tobacco smoking', 'periodontal disease', 'dental implant', and 'oral cancers and precancers'.

DATA EXTRACTION

Evidence-based literature review.

DATA SYNTHESIS

The prevalence and severity of periodontal diseases in their various forms are higher among smokers than among non-smokers. The success of dental implant treatments is significantly influenced by addiction to tobacco smoking. The failure rate of implant osseointegration is considerably higher among smokers, and maintenance of oral hygiene around the implants and risk of peri-implantitis are adversely affected by smoking. The risks of developing oral cancers and precancers are greater in smokers. Betel nut chewing and smokeless tobacco produce similar risk to cancer incidence as tobacco smoking. Cessation of tobacco use has a beneficial effect on halting the progression of periodontal diseases and on the outcome of periodontal therapy.

CONCLUSIONS

Medical and dental teams should be aware of oral problems associated with tobacco use. Counselling on smoking cessation and smoking prevention programmes should be an integral component of medical and dental teaching and practice.

Prevalence of impacted teeth and associated pathologies--a radiographic study of the Hong Kong Chinese population

OBJECTIVES

To investigate the prevalence and pattern of impacted teeth and associated pathologies in the Hong Kong Chinese population.

SETTING

The Reception and Primary Care Clinic, Prince Philip Dental Hospital, Hong Kong.

DESIGN

Retrospective study.

SUBJECTS AND METHODS

The records of 7486 patients were examined to determine whether the chief complaints were related to impacted teeth and associated pathologies, which were investigated using panoramic radiographs.

RESULTS

A total of 2115 (28.3%) patients presented with at least one impacted tooth. Among the 3853 impacted teeth, mandibular third molars were the most common (82.5%), followed by maxillary third molars (15.6%), and maxillary canines (0.8%). Approximately 8% of mandibular second molars associated with impacted third molars had periodontal bone loss of more than 5 mm on their distal surfaces. Caries were also found on the same surfaces in approximately 7% of the second molars. Approximately 30% of patients with dental impaction had symptoms, and 75% had complaints limited to one side of the mouth.

CONCLUSIONS

The prevalence of impacted teeth was high, and there was a predilection for impacted third molars in the mandible. More than 50% of maxillary third molars had erupted, creating potential trauma of the pericoronal tissues of the partially erupted mandibular third molars. Caries and periodontal diseases were commonly seen in relation to the impacted third molars, whereas cystic pathology and root resorption were rarely observed.

The biological behaviour of human adenoid cystic carcinoma cells transduced with interleukin-2-gene

Adenoid cystic carcinoma (ACC) of the salivary glands is a highly infiltrative malignant tumour with a tendency for lung metastasis. Gene therapy could be a potentially effective therapy for ACC and its metastasis. The aims of the study were: To transduce interleukin-2 (IL-2) gene into an ACC cell line with predisposition for lung metastasis (ACC-M); to compare the bioactivity of the gene-transduced cells and the parent cell line in vitro and in vivo. The IL-2 gene was transduced via a bicistronic retroviral vector into the ACC-M cells. The growth rate and DNA cell cycles of the parent ACC-M, the control viral vector AmGCEN, and the gene transduced AmIL-2 cell cultures were compared quantitatively and by flow cytometry, respectively. The tumourigenic ability of the three cell lines was verified by inoculation in athymic nude mice. The tumours developed were extracted and compared quantitatively and histologically. There was no difference in the growth rate and the DNA count between the ACC-M, AmGCEN, and AmIL-2 cell cultures. In the animal experiment, both the ACC-M and AmGCEN cells stimulated lung metastasis in all the mice, whereas there was no tumour found in the 1 x 10(6) AmIL-2 cells inoculation. On 3 x 10(6) AmIL-2 cells stimulation, three out of six mice developed tumours but the mass and volume of the tumours were smaller than the other two groups. Under light microscopy, the ACC-M tumours were mainly poorly differentiated with minimal cellular matrix, whereas the AmIL-2 tumours were well differentiated with ample matrix. The transduction of IL-2 gene can reduce the tumourigenicity of ACC-M cells and induces tumour cell differentiation in mice. The IL-2 gene can be a potential effective gene for the treatment of adenoid cystic carcinoma of salivary glands and its lung metastasis.

Refinement of facial reconstructive surgery by stereo-model planning

The development of rapid prototyping has evolved from crude milled models to laser polymerized stereolithographic models of excellent accuracy. The technology was advanced further with the recent introduction of fused deposition modelling and a three-dimensional ink-jet printing technique in stereo-model fabrication. The concept of using a three-dimensional model in planning the operation has amazed maxillofacial surgeons since its first application in grafting a skull defect in 1995. It was followed by many bright ideas for applications in the field of facial reconstructive surgery. Stereo-models may assist in diagnosis of facial fractures, joint ankylosis and even impacted teeth. The surgery can be simulated prior the operation of complex craniofacial syndromes, facial asymmetry and distraction osteogenesis. The stereo-model can be used for preparation of reconstructive plate or joint prostheses. It is of enormous value for educational teaching and as a patient information tool when obtaining the consent for surgery.

An evaluation of complications following dental extractions using either sterile or clean gloves

This randomized prospective study aims to evaluate any differences in the postoperative infection rate from dental extraction using either sterile or clean surgical gloves and to determine any predisposing factors that may complicate socket healing. A total of 609 patients were randomly assigned to two groups, with the operators wearing either sterile or clean gloves in performing forcep extractions. 551 patients, who had 811 extractions performed, returned for the postoperative assessment visit. There was no difference in the incidence of an acutely inflamed socket, acutely infected socket and dry socket and also no significant predisposing factors found between the sterile and clean glove groups. The pre-operative diagnosis of caries, periodontal disease or retained root had a higher tendency of producing an acute-inflamed socket, whereas an acutely infected socket only developed in the cases of retained root. On the pain intensity level, an acutely inflamed socket caused mild to moderate pain, on acutely infected socket caused moderate to severe pain; and a dry socket caused severe pain in the majority of cases. The study concluded that the use of sterile surgical gloves does not offer an advantage over clean gloves in minimizing socket inflammation, infection, as well as a dry socket following dental extraction.

Attitudes about organ and tissue donation among the general public and blood donors in Hong Kong

CONTEXT

The cadaveric organ and tissue donation rate in Hong Kong is not satisfactory; 1 million blood donors are registered and more than 300,000 are active. However, the current attitudes toward organ and tissue donation in the general public and blood donors of Hong Kong are unknown.

METHODS

Random general public (n = 1018) and blood donors (n = 1227) of Chinese origin, with age ranging from 16 to 60 years, were interviewed using a standard verified questionnaire that examines attitudes and knowledge of organ and tissue donation.

RESULTS

The mean age of the general public and blood donors were 32.6 and 28.9 years, respectively. Of the general public, 44.4% were men and among blood donors, 60% were men. About 56% of both groups thought that organ donation is an obligation of citizens. Blood donors were more aware than the general public about the types of organs that can be donated. When compared with the general public, a significantly higher percentage of blood donors were willing to donate their organs (81% vs 53%), had heard about organ donation cards (98.3% vs 89.5%), and had signed the cards (49.9% vs 22.6%). About 70% of both groups who had signed a card were carrying it. Thirty-nine percent of the general public and 17% of blood donors had not decided whether they would donate. For blood donors, 49.7% were willing to donate their relatives' organs, compared with 41.8% of the general public. Most individuals in both groups would not object to their relatives' decision to donate. About two thirds of individuals in both groups disagreed with the concept of an opt-out law, though only 20% of the general public and 14.4% of blood donors would refuse donation if an opt-out law were in practice.

CONCLUSIONS

This study shows that blood donors have better knowledge of organ donation and are more willing to donate their organs and sign an organ donation card than the general public. However, a substantial proportion of blood donors have not signed a donor card. It would be useful to design promotion programs to facilitate blood donors' participation in organ donation.

Different effects of a single amino acid substitution on three adjacent epitopes in the gp41 C-terminal tail of a neutralizing antibody escape mutant of human immunodeficiency virus type 1

The envelope protein of human immunodeficiency virus type 1 (HIV-1) comprises the outer gp 120 SU domain and the anchoring gp41 TM domain, and the conventional view is that it has a single transmembrane region with the following C-terminal sequence situated entirely within the virion. However, we have recently proposed that the gp41 C-terminal region comprises three transmembrane regions and an external loop structure. Part of this loop is the peptide 731PRGPDRPEGIEEEGGERDRDRS752 that carries three antibody epitopes, 734PDRPEG739, 740IEEE743, and 746ERDRD750. PDRPEG is not detected in virions but reacts with its cognate MAb (C8) in Western blots, IEEE is a linear and non-neutralizing epitope, and ERDRD is a conformational and neutralizing epitope. Here we show that escape mutants selected with neutralizing ERDRD-specific antibody had a single 732R-->G substitution, 14 residues upstream of the cognate epitope, and no longer bound the selecting antibody. The same amino acid substitution altered epitope PDRPEG in the virion so that it now reacted with MAb C8, but left epitope IEEE unaffected. Introduction of 732R-->G by site-specific mutagenesis into the gp41 of cloned HIV-1 NL4-3 virions allowed them to escape neutralization by ERDRD-specific IgG, and confirms that 732R makes a major contribution to the neutralizing conformation of the 731-752 region of the C-terminal tail of gp41.

Pecam-1 is a modulator of stat family member phosphorylation and localization: lessons from a transgenic mouse

PECAM-1 (CD31) is a member of the immunoglobin (Ig) superfamily of cell adhesion molecules whose expression is restricted to hematopoietic and vascular cells. PECAM-1 can recruit adapter and signaling molecules via its immunoreceptor tyrosine activation motif (ITAM), suggesting that PECAM-1 plays a role in signal transduction pathways. To study the involvement of PECAM-1 in signaling cascades in vivo, we used the major histocompatibility (MHC) I gene promoter to target ectopic PECAM-1 expression in transgenic mice. We noted an attenuation of mammary gland development at early stages of virgin ductal branching morphogenesis. STAT5a, a modulator of milk protein gene expression during lactation, was localized to the nuclei of ductal epithelial cells of 6-week-old virgin PECAM-1 transgenics, but not in control mice. This correlated with decreases in ductal epithelial cell proliferation and induction of p21, an inhibitor of cell cycle progression. Using in vitro model systems we demonstrated PECAM-1/STAT5a association and found that residue Y701 in PECAM-1's cytoplasmic tail is important for PECAM-1/STAT5 association and that PECAM-1 modulates increases in STAT5a tyrosine phosphorylation levels. We suggest that by serving as a scaffolding, PECAM-1 can bring substrates (STAT5a) and enzymes (a kinase) into close proximity, thereby modulating phosphorylation levels of selected proteins, as previously noted for beta-catenin.

PECAM-1 shedding during apoptosis generates a membrane-anchored truncated molecule with unique signaling characteristics

Shedding of cell surface molecules, including growth factor receptors, provides a mechanism by which cells regulate signal transduction events. Here we show that platelet-endothelial cell adhesion molecule (PECAM)-1 is shed from the endothelial cell surface during apoptosis and accumulates in the culture medium as a approximately 100 kDa soluble protein. The cleavage mediating the shedding is matrix metalloproteinase (MMP) dependent, as GM6001, a broad-spectrum MMP inhibitor, inhibits PECAM-1 accumulation in the culture medium in a dose-responsive manner. In addition to the 100 kDa soluble fragment, PECAM-1 cleavage generates the formation of a truncated (Tr.) approximately 28 kDa molecule, composed of the transmembrane and the cytoplasmic PECAM-1 domains. Transfections of the full-length (Fl) and the Tr. PECAM-1 gene constructs into endothelial and nonendothelial cells were performed. We found 1) significantly more gamma-catenin and SHP-2 bound to the truncated than to the full-length PECAM-1; 2) stable expression of the truncated PECAM-1 in SW480 colon carcinoma cells resulted in a dramatic decrease in cell proliferation, whereas expression of comparable levels of the full-length PECAM-1 had no effect; 3) the decrease observed in cell proliferation is due, in part, to an increase in programmed cell death (apoptosis) and correlated with continuous caspase 8 cleavage and p38/JNK phosphorylation. These results support the intimate involvement of PECAM-1 in signal transduction cascades and also suggest that caspase substrates (e.g., PECAM-1) may possess distinct and unique functions on cleavage.