A new sesquiterpenoid from the rhizomes of Homalomena sagittifolia

A new sesquiterpenoid, 1α,4β,7β-eudesmanetriol (1), was isolated together with the known compounds 1β,4β,7β-eudesmanetriol (2) and oplopanone (3) from the rhizomes of Homalomena sagittifolia. The structures of these compounds were determined by extensive spectral analyses. The compounds 1 and 2 inhibited growth of Pseudomonas stutzeri with a MIC value of 117 µM when evaluated for antibacterial activity using the minimum concentration assay. Both these compounds showed remarkable activities against acetylcholinesterase enzyme with IC(50) values ranging between 25 and 26 µM. The isolation of these sesquiterpenoids and their biological activities observed in this study support the reported traditional uses of H. sagittifolia for the treatment of microbial related diseases and central nervous system disorders.

Navigation Endoscopic Assisted Tumor (NEAT) surgery for benign bone tumors of the extremities

A novel technique of using both a navigation system and an endoscope in intra-lesional curettage of benign bone tumors enables safe and adequate tumor removal via a minimal access approach. We performed curettage of benign bone tumors in five consecutive patients (4 female, 1 male, mean age 31.4 years) using a commercial CT-based navigation system supplemented by visual guidance through a shoulder arthroscope. The bone defect was filled with bone cement in four patients and with artificial bone substitute in one patient. Mean follow-up time was 8.8 months (range: 7-12 months). Mean duration of surgery was 144 min (range: 120-165 min). Mean wound length of each portal site was 19.5 mm (range: 15-25 mm). All patients could achieve a full range of joint movement and walk unaided at 4 weeks post-surgery. No local recurrence was noted.

Integration of CAD/CAM planning into computer assisted orthopaedic surgery

Modern Computer Aided Design/Modeling (CAD/CAM) software allows complex surgical simulations, but it is often difficult to transfer and execute precisely the planned scenarios during actual operations. We describe a new method of integrating CAD/CAM surgical plans directly into a computer surgical navigation system, and demonstrate its use to guide three complex orthopaedic surgical procedures: a periacetabular osteotomy of a dysplastic hip, a corrective osteotomy of a post-traumatic tibial deformity, and a multi-planar resection of a distal femoral tumor followed by reconstruction with a CAD custom prosthesis.

Focused ion beam characterization of bicomponent polymer fibers

Previous work has shown that focused ion beam (FIB) nanomachining can be effectively utilized for the cross-sectional analysis of polymers such as core-shell solid microspheres and hollow latex nanospheres. While these studies have clearly demonstrated the precise location selection and nanomachining control provided by the FIB technique, the samples studied consisted of only a single polymer. In this work, FIB is used to investigate bicomponent polymeric fiber systems by taking advantage of the component's differing sputter rates that result from their differing physical properties. An approach for cross sectioning and thus revealing the cross-sectional morphology of the polymeric components in a bicomponent polymeric fiber with the island-in-the-sea (I/S) structure is presented. The two I/S fibers investigated were fabricated using the melt spinning process and are composed of bicomponent combinations of linear low density polyethylene (LLDPE) and nylon 6 (PA6) or polylactic acid (PLA) and an EastONE proprietary polymer. Topographical contrast as a result of differential sputtering and the high surface specificity and high signal-to-noise obtained using FIB-induced secondary electron imaging is shown to provide a useful approach for the rapid characterization of the cross-sectional morphology of bicomponent polymeric fibers without the necessity of staining or other sample preparation.

Initial presentation and management of osteosarcoma, and its impact on disease outcome

OBJECTIVE

To evaluate the initial presenting symptoms and management of osteosarcoma in Hong Kong Chinese children, in relation to any possible impact on disease outcomes.

DESIGN

Retrospective study.

SETTING

A tertiary referral centre of bone cancer in a university teaching hospital in Hong Kong.

PATIENTS

All children aged younger than 18 years with a diagnosis of osteosarcoma who received treatment from March 1994 to October 2005.

RESULTS

A total of 51 children were studied. The median age of onset was 13 (range, 3-20) years; 61% were males. The tumours were located in the distal femur and proximal tibia, which accounted for 45% and 22% of the cases, respectively; 24% of patients had metastatic disease at presentation. Swelling (76%) and pain (90%) were the most common presenting complaints. Approximately one third of the patients had a preceding history of trauma. The median duration of initial symptoms to first medical consultation of any sort was 30 (range, 0-360) days. The median time from the first consultation to a definitive diagnosis was 21 (range, 0-350) days; 25% were diagnosed more than 52 days after presentation. Bonesetters were initially consulted by 37% of these patients. From presentation to diagnosis, the median duration was 61 (range, 4-361) days. Analysis of the duration of pre-diagnosis symptoms did not correlate significantly with the development of metastatic disease, response to chemotherapy, feasibility of limb salvage surgery, relapse rates, or survival rates.

CONCLUSIONS

In Hong Kong, initial consultation to bonesetters was common. A relatively long delay in between symptom onset and diagnosis of osteosarcoma was encountered. The public and medical practitioners should be made aware of this disease, especially in adolescents.

catena-Poly[[sodium-di-μ-β-d-glucose] chloride]

The asymmetric unit of the title compound, {[Na(C(6)H(12)O(6))(2)]Cl}(n), contains six glucose mol-ecules, three Na(+) ions and three Cl(-) ions, i.e. three independent {[Na(C(6)H(12)O(6))(2)]Cl} units. Each of these units forms polymeric chains along the c axis. Each Na(+) ion is surrounded by six O atoms from four glucose mol-ecules, forming a distorted octa-hedral geometry. All glucose mol-ecules adopt chair conformations. The constituent units are linked into a three-dimensional framework by O-H⋯Cl and O-H⋯O hydrogen bonds, utilizing all the O-H groups.

Characteristics of ovarian cancer in women residing in Aotearoa, New Zealand: 1993-2004

BACKGROUND

Few studies have compared ovarian cancer rates between different ethnic groups in the same country. The aim of this study was to describe ethnic patterns in the incidence and mortality of ovarian cancer in New Zealand, and to investigate ethnic and socioeconomic differences in the grade and stage of ovarian cancer.

METHODS

Data on all women registered with ovarian cancer on the New Zealand Cancer Registry (1993-2004) were analysed. Population data were taken from the 1996 and 2001 census. Logistic regression was used to estimate associations between ethnicity, deprivation and tumour characteristics.

RESULTS

Age-standardised incidence rates were highest in Pacific women, intermediate in Māori women, and lowest in non-Māori, non-Pacific women. Age-standardised mortality rates showed the same pattern. Ovarian cancer subtypes differed by ethnic group. There was no significant association between socioeconomic deprivation and tumour grade or stage. Age-adjusted models showed that Māori women were more likely to have well-differentiated tumours and less likely to present at a later stage compared to non-Māori, non-Pacific women. These patterns were partly explained by socioeconomic deprivation, and were not apparent for Pacific women.

CONCLUSIONS

Pacific and Māori women experience higher incidence of ovarian cancer and mortality, compared to non-Māori, non-Pacific women. Māori women seemed to have better prognostic factors (local stage and well-differentiated tumours) than non-Māori, non-Pacific women. More work is needed to improve current cancer prevention strategies, particularly in Pacific women.

Differential fadE28 expression associated with phenotypic virulence of Mycobacterium tuberculosis

Ability to persist in human macrophages is central to the virulence of Mycobacterium tuberculosis and is not invariable among various strains. Differential gene expression that is associated with phenotypic virulence may provide additional information of virulent genes involved in the pathogenesis of M. tuberculosis, which is not fully elucidated. Three hypervirulent strains of M. tuberculosis isolated from patients suffering with tuberculous meningitis were shown to grow more rapidly inside human macrophages in a previous study. In the current investigation, expression of 7 mycobacterial genes (fadE28, mce1A, mymA, acr, sigA, sugC, and Rv3723) of these strains during ex vivo macrophage challenge and in vitro acid shock was quantified by real-time PCR. Using rrs gene as a normalisation gene, fadE28 gene exhibited differential gene expression that is associated with phenotypic virulence, whereas the other 6 genes showed indistinguishable expression patterns. Up-regulation of fadE28 gene in the hypervirulent strains may account for virulence by increasing the efficiency of beta-oxidation, which is important for the persistence in macrophages as M. tuberculosis uses fatty acids preferably inside phagosome of macrophages. The fadE28 gene, together with its adjacent genes may also be critical in the process of lipid modification that could facilitate parasitism in human macrophages.

Precision tumour resection and reconstruction using image-guided computer navigation

The use of a navigation system in musculoskeletal tumour surgery enables the integration of pre-operative CT and MRI images to generate a precise three-dimensional anatomical model of the site and the extent of the tumour. We carried out six consecutive resections of musculoskeletal tumour in five patients using an existing commercial computer navigation system. There were three women and two men with a mean age of 41 years (24 to 47). Reconstruction was performed using a tumour prosthesis in three lesions and a vascularised fibular graft in one. No reconstruction was needed in two cases. The mean follow-up was 6.9 months (3.5 to 10). The mean duration of surgery was 28 minutes (13 to 50). Examination of the resected specimens showed clear margins in all the tumour lesions and a resection that was exactly as planned.

Molecular characterization of clinical isolates of Mycobacterium tuberculosis and their association with phenotypic virulence in human macrophages

Among 125 clinical isolates of Mycobacterium tuberculosis collected in Hong Kong and Shanghai, China, between 2002 and 2004, IS6110 typing revealed that 71 strains (57%) belonged to the Beijing family. The intracellular growth of the strains in human peripheral blood monocyte-derived macrophages was measured ex vivo on days 0, 3, 6, and 10. Among all tested strains, three hypervirulent strains showed significant increases in intracellular growth after 10 days of incubation. With an initial bacterial load of 10(4) CFU, most of the clinical isolates and H37Ra (an avirulent strain) exhibited no intracellular survival on day 10, while the three hypervirulent strains together with H37Rv (a virulent strain) showed on average a two- to fourfold rise in CFU count. These three hypervirulent strains belonging to a non-Beijing family were isolated from patients suffering from tuberculosis meningitis. Cytokines secreted by gamma interferon-activated macrophages were measured daily after challenge with selected strains of M. tuberculosis. The levels of tumor necrosis factor alpha were elevated after 24 h of infection among all strains, but the levels were significantly lower among the three hypervirulent strains, whereas interleukin 10 (IL-10) and IL-12 were not detected. Results were concordant with the differential expression of the corresponding cytokine genes in activated macrophages, as monitored by real-time PCR. Our findings highlighted that these three hypervirulent strains may possess an innate mechanism for escaping host immunity, which accounts for their characteristic virulence in patients presenting with a more severe form of disease.

Urine protein-to-creatinine ratio in an untimed urine collection is a reliable measure of proteinuria in lupus nephritis

OBJECTIVE

To evaluate the accuracy of urine protein-to-creatinine (P/C) ratio in an untimed urine specimen as compared with 24 h total protein excretion for measurement of proteinuria in patients with lupus nephritis.

METHODS

Proteinuria in patients with lupus nephritis was assessed by 24 h total protein excretion and spot urine P/C ratio. Correlation and limits of agreement between the two methods were evaluated. The discriminant cutoff values for spot urine P/C ratio in predicting 24 h protein 'threshold' excretion of > or =0.3, > or =0.5, > or =1.0 and > or =3.5 g/day were determined using receiver operating characteristic curves.

RESULTS

A total of 165 samples were available for assessment with 21.8% excluded due to inadequate collection. A strong correlation (r = 0.91, P < 0.0001) was found between spot urine P/C ratio and 24 h urine protein excretion. Bland-Altman plot showed the two tests had acceptable limits of agreement in low level of protein excretion (-0.86 to +0.92 g/day when protein excretion was <2.0 g/day). The limits became wider as the protein excretion increased. The spot urine P/C ratios of 0.45 (sensitivity 0.92; specificity 0.88), 0.7 (0.92; 0.89) and 1.84 (1.0; 0.86) mg/mg reliably predicted 24 h urine total protein equivalent 'thresholds' at > or =0.5, 1.0 and 3.5 g/day.

CONCLUSION

This study supports the recommendation of using spot urine P/C ratio in screening and monitoring proteinuria in patients with lupus nephritis. However, in assessing the exact amount of proteinuria, the urine P/C ratio may have unacceptably wide limits of agreement in high protein excretion range.

Transvenous embolisation of a carotid-trigeminal cavernous fistula

A carotid cavernous fistula is an abnormal communication between the internal carotid artery and the cavernous sinus. Rarely, this communication is associated with a persistent primitive trigeminal artery, with or without a trigeminal artery aneurysm. We report a case of spontaneous carotid-trigeminal cavernous fistula in which the persistent trigeminal artery was shown only on vertebral artery injection. The absence of an associated trigeminal artery aneurysm allowed a transvenous approach for endovascular treatment with coils and complete obliteration of the cavernous fistula.

Application of the mixed venous blood concentration equation in desflurane anesthesia

BACKGROUND

We have previously proposed an equation derived from Fick's law and Lin's concept of effective blood concentration (EBC) to calculate the mixed venous blood concentration (MVBC) of isoflurane. Desflurane has a lower blood/air partition coefficient than isoflurane and, as such, promotes a faster induction and recovery from anesthesia. In this study, we investigated the application of the MVBC equation to predict the MVBC of desflurane.

METHODS

We maintained anesthesia with a fixed inspired concentration (CI) of desflurane (10%) during cardiac anesthesia in 11 patients. In order to measure the real concentrations of desflurane in mixed venous blood, pulmonary arterial blood samples were collected at different time points via a Swan-Ganz catheter for gas chromatographic-mass spectrometric determination. The relationship between the calculated concentrations and the actual blood sample concentrations of desflurane in mixed venous blood was investigated. Lin's EBC method was also used and the results were compared with those of MVBC.

RESULTS

The calculations from our derived MVBC equation and the actual blood concentrations showed a similar kinetic pattern; the concentration levels were approximately the same and correlated well (r = 0.89) during anesthesia. However, the EBC method failed to accurately estimate the actual blood concentrations.

CONCLUSIONS

The results demonstrate that our equation, but not the EBC method, may be useful for estimating pulmonary blood concentrations of desflurane. The clinical significance and the importance of the method merit further investigation.