Appendectomy and asthma: a search for an association in older subjects.

INTRODUCTION: Several risk factors found to be associated with postoperative complications and cancer surgery, which carry a significant morbidity risk to cancer patients. Therefore, prehabilitation is necessary to improve the functional capability and nutritional status of a patient prior to surgery, so that the patient can withstand any postoperative activity and associated deterioration. Thus, this study aims to assess the effectiveness of prehabilitation interventions on the functional status of patients with gastric and oesophageal cancer who underwent esophagectomy and gastrectomy. MATERIAL AND METHODS: An interventional study was carried out among oesophageal and gastric cancer patients who had undergone surgery at the National Cancer Institute of Malaysia. The prehabilitation process took a maximum of two weeks, depending on the patient's optimisation before surgery. The prehabilitation is based on functional capacity (ECOG performance status), muscle function (handgrip strength), cardio-respiratory function (peak flow meter) and nutritional status (calorie and protein). Postoperative outcomes are measured based on the length of hospital stay, complications, and Clavien-Dindo Classification. RESULTS: Thirty-one patients were recruited to undergo a prehabilitation intervention prior to gastrectomy (n=21) and esophagectomy (n=10). Demographically, most of the cancer patients were males (67.7%) with an ideal mean of BMI (23.5±6.0). Physically, the majority of them had physical class (ASA grade) Grade 2 (67.7%), ECOG performance status of 1 (61.3%) and SGA grade B (51.6%). The functional capacity and nutritional status showed a significant improvement after one week of prehabilitation interventions: peak expiratory flow meter (p<0.001), handgrip (p<0.001), ECOG performance (p<0.001), walking distance (p<0.001), incentive spirometry (p<0.001), total body calorie (p<0.001) and total body protein (p=0.004). However, those patients who required two weeks of prehabilitation for optimization showed only significant improvement in peak expiratory flow meter (p<0.001), handgrip (p<0.001), and incentive spirometry (p<0.001). Prehabilitation is significantly associated postoperatively with the length of hospital stay (p=0.028), complications (p=0.011) and Clavien-Dindo Classification (p=0.029). CONCLUSION: Prehabilitation interventions significantly increase the functional capacity and nutritional status of cancer patients preoperatively; concurrently reducing hospital stays and complications postoperatively. However, certain cancer patients might require over two weeks of prehabilitation to improve the patient's functional capacity and reduce complications postoperatively.

Insights from molecular docking and molecular dynamics on the potential of vitexin as an antagonist candidate against lipopolysaccharide (LPS) for microglial activation in neuroinflammation.

BACKGROUND: Neuroinflammation has been identified to be the key player in most neurodegenerative diseases. If neuroinflammation is left to be unresolved, chronic neuroinflammation will be establish. Such situation is due to the overly-activated microglia which have the tendency to secrete an abundance amount of pro-inflammatory cytokines into the neuron microenvironment. The abundance of pro-inflammatory cytokines will later cause toxic and death to neurons. Toll-like receptor 4 (TLR4)/MD-2 complex found on the cell surface of microglia is responsible for the attachment of LPS and activation of nuclear factor-κB (NF-κB) downstream signalling pathway. Albeit vitexin has been shown to possess anti-inflammatory property, however, little is known on its ability to bind at the binding site of TLR4/MD-2 complex of microglia as well as to be an antagonist for LPS. RESULTS: The present study reveals that both vitexin and donepezil are able to bind at the close proximity of LPS binding site located at the TLR4/MD-2 complex with the binding energy of - 4.35 and - 9.14 kcal/mol, respectively. During molecular dynamic simulations, both vitexin and donepezil formed stable complex with TLR4/MD-2 throughout the 100 ns time length with the root mean square deviation (RMSD) values of 2.5 Å and 4.0 Å, respectively. The root mean square fluctuation (RMSF) reveals that both compounds are stable. Interestingly, the radius of gyration (rGyr) for donepezil shows notable fluctuations when compare with vitexin. The MM-GBSA results showed that vitexin has higher binding energy in comparison with donepezil. CONCLUSIONS: Taken together, the findings suggest that vitexin is able to bind at the binding site of TLR4/MD-2 complex with more stability than donepezil throughout the course of 100 ns simulation. Hence, vitexin has the potential to be an antagonist candidate for LPS.

Staphylococcal aureus bacteraemia: Clinical characteristic & evaluation of Prolex Staph Xtra latex agglutination test in the rapid identification of Staphylococcus aureus.

BACKGROUND: Staphylococcus aureus is a leading cause of community as well as healthcare-associated bacteraemia. This study aimed to describe clinical characteristics of S. aureus bacteraemia (SAB) and to evaluate the performance of the Prolex Staph Xtra Latex agglutination test in the identification of Staphylococcus aureus. METHODS: Cross-sectional study was conducted from Jun 2018 to May 2019. Isolates from first-positive peripheral blood cultures were tested with Prolex Staph Xtra Latex agglutination test, together with routine tube coagulase and DNase test. All isolates were further confirmed with Vitek2 GP. RESULTS: Hundred isolates were tested with Prolex Staph Xtra Latex. Twelve isolates were excluded due to incomplete medical records. Eighty-eight isolates were analysed, yielded sensitivities, specificities, positive and negative predictive values of 100%, 91.7%, 98.7%, and 100%, respectively. Of these, 76 were identified as S. aureus and 12 CoNS. Seventy-six patients were included in the SAB analysis. Fifty-nine out of 76 (78.6%) had underlying comorbidities. Thirty-four percent of the episodes were considered as primary SAB. Skin and soft tissue infection were accounted for the highest source of bacteraemia, 24(31.6%). Both MRSA and MSSA bacteraemia were seen mostly among healthcare-associated bacteraemia (HCA) (7/16, 43.8% and 28/60, 46.7%). Liver cirrhosis was significantly associated with MRSA bacteraemia (P=0.048). Metastatic infection & complicated SAB were identified in 13(17.1%) and 30(39.5%) of cases, respectively. All-cause mortality was 22.4%. CONCLUSION: S. aureus bacteraemia is a serious infection associated with significant metastatic complications and mortality. Prolex Staph Xtra Latex agglutination test has excellent sensitivity and specificity with 100% and 91.7% respectively.

Functionality among stroke survivors with upper limb impairment attending community-based rehabilitation.

INTRODUCTION: There is scarcity of research information on upper limb (UL) functionality among Malaysian post-stroke population despite the increasing number of stroke survivors. This study intends to evaluate functionality among stroke survivors residing in the community, with a specific focus on the UL. METHODS: This cross-sectional study involved 65 stroke survivors with UL dysfunction (mean (SD) age = 64.83 (8.05) years, mean (SD) post-stroke duration 41.62 (35.24) months) who attended community-based rehabilitation program. Upper limb functionality was assessed using the UL items of Stroke Specific Quality of Life Scale (SSQOL), the Lawton Instrumental Activities of Daily Living (IADL) Scale and the Jebsen-Taylor Hand Function Test (JTHFT). The stroke survivors' performance in completing JTHFT using their affected dominant hand was compared with standard norms. RESULTS: The three most affected UL daily living tasks were writing (64.7%, n=42), opening a jar (63.1%, n=41) and putting on socks (58.5%, n=38). As for IADL, the mean (SD) score of Lawton scale was 3.26 (2.41), with more than 50% unable to handle finance, do the laundry and prepare meals for themselves. Performances of stroke survivors were much slower than normal population in all tasks of JTHFT (p<0.05), with largest speed difference demonstrated for 'stacking objects' task (mean difference 43.24 secs (p=0.003) and 24.57 (p<0.001) in males and females, respectively. CONCLUSION: UL functions are significantly impaired among stroke survivors despite undergoing rehabilitation. Rehabilitation professionals should prioritize highly problematic tasks when retraining UL for greater post-stroke functionality.

Lymphoma with superimposed tuberculosis and fungal infection mimicking parapharyngeal abscess complicated with recurrent neurocardiogenic syncope: a case report.

INTRODUCTION: Lymphoma of parapharyngeal space (PPS) is a rare condition. The clinical presentations may vary and often masquerades as infection or an inflammatory condition. A misdiagnosis will lead to a delay in treatment of the disease. Due to the complex anatomy of PPS, any attributed pressure from masses can lead to a life-threatening event such as cardiac syncope. CASE REPORT: We report a rare case of PPS B-cell non-Hodgkin lymphoma with superimposed Tuberculosis (TB) and fungal infection that presents with several episodes of syncope and hemodynamic depression. DISCUSSION: The clinical entities in PPS lesions syncope and its associated syndromes, pathophysiology, and differential diagnosis together with possible managements are further discussed.

Elderly males with or without existing osteoporotic vertebral fracture have much lower future vertebral fracture risk than elderly females: the MrOS (Hong Kong) year-4 follow-up spine radiograph study.

MrOS (Hong Kong)'s year-4 follow-up shows, for subjects at baseline without vertebral deformity (VD) and endplate or/and cortex fracture (ECF), the VD progression/new VD rate during follow-up in males was half of our paired MsOS (Hong Kong) study's results. For those with VD or ECF, the VD progression/new VD was less than one sixth of females' rate. INTRODUCTION: This study documents MrOS (Hong Kong)'s year-4 follow-up, and the results are compared with the MsOS (Hong Kong) study. Of elderly females with Genant's grade-0, -1, -2, and -3 VD, at year-4 follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or incident VD, respectively. METHODS: Spine radiographs of 1500 Chinese males with baseline (mean age 71.7 years, range 65-91 years) and year-4 follow-up were evaluated according to Genant's VD criteria and ECF (non-existent, ECF0; or existent, ECF1). Grade-2 VDs were divided into mild (VD2m, 25-34% height loss) and severe (VD2s, 34-40% height loss) subgroups. Study subjects were graded into eight categories: VD0/ECF0, VD1/ECF0, VD2m/ECF0, VD0/ECF1, VD1/ECF1, VD2m/ECF1, VD2s/ECF1, and VD3/ECF1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new VD incident was a change from grade-0 to grade-2/3, or to grade-1 with ≥ 10% height loss. RESULTS: Of subjects with Genant's grade-0, 2.05% (25/1219) developed at least one VD progression or/and new VD, while of subjects with Genant's grade-1, -2, and -3 VD, only 2% (3/149), 3.1% (3/96), and 2.8% (1/36) developed at least one VD progression/new VD, respectively. Among the three ECF0 groups, there was a significant difference in new ECF incidence, with VD0/ECF0 being the lowest and VD2m/ECF0 being the highest. CONCLUSION: VD progression/new VD is much less common in elderly men than in elderly women. Vertebrae with VD had a higher risk of developing ECF.

Osteoporotic vertebral deformity with endplate/cortex fracture is associated with higher further vertebral fracture risk: the Ms. OS (Hong Kong) study results.

Compared with vertebrae without deformity, vertebrae with mild/moderate deformity have a higher risk of endplate or/and cortex fracture (ecf). Compared with subjects without ecf, subjects with ecf are at a higher risk of short-term (4-year period) deformity progression and new incident deformity. INTRODUCTION: The progression and incidence of osteoporotic vertebral deformity/fracture (VD/VF) in elderly Chinese females remain not well documented. METHODS: Spine radiographs of 1533 Chinese females with baseline and year-4 follow-up (mean age 75.7 years) were evaluated according to Genant's VD criteria and endplate/cortex fracture (non-existent: ecf0 or existent: ecf1). Grade-2 VDs were divided into mild (vd2m, 25-34% height loss) and severe (vd2s, 34-40% height loss) subgroups. According to their VD/VF, subjects were graded into seven categories: vd0/ecf0, vd1/ecf0, vd2m/ecf0, vd1/ecf1, vd2m/ecf1, vd2s/ecf1, and vd3/ecf1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new incident VD was a change from grade-0 to grade-2/3 or to grade-1 with ≥ 10% height loss. RESULTS: Of subjects with Genant's grades 0, - 1, - 2, and - 3 VD, at follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or new incident VD respectively. Among the three ecf0 groups, there was no difference in VD progression or new VD; while there was a significant difference in new ecf incidence, with vd0/ecf0 being lowest and vd2m/ecf0 being highest. Vd1/ecf0 and vd2m/ecf0 vertebrae had a higher risk of turning to ecf1 than vd0/ecf0 vertebrae. If vd1/ecf0 and vd2m/ecf0 subjects were combined together (range 20-34% height loss) to compare with vd1/ecf1 and vd2m/ecf1 subjects, the latter had significantly higher VD progression and new VD rates. CONCLUSION: Vertebrae with grade-1/2 VDs had a higher risk of developing ECF. Subjects with pre-existing ECFs had a higher risk of worsening or new vertebral deformities.

Finned spacer for efficient membrane fouling control in produced water filtration.

Membrane based technologies are highly reliable for water and wastewater treatment, including for removal of total oil and grease from produced water. However, performances of the pressure driven processes are highly restricted by membrane fouling and the application of traditional air bubbling system is limited by their low shear stress due to poor contacts with the membrane surface. This study develops and assesses a novel finned spacer, placed in between vertical panel, for membrane fouling control in submerged plate-and-frame module system for real produced water filtration. Results show that permeability of the panel is enhanced by 87% from 201 to 381 L/(m2 h bar). The spacer system can be operated in switching mode to accommodate two-sided panel aeration. This leads to panel permeability increment by 22% higher than the conventional vertical system. The mechanisms of finned spacer in encouraging the flow trajectory was proven by visual observation and flow simulation. The fins alter the air bubbles flow trajectory toward the membrane surface to effectively scour-off the foulant. Overall results demonstrate the efficacy of the developed spacer in projecting the air bubble trajectory toward the membrane surface and thus significantly enhances membrane panel productivity.

Two-way switch: Maximizing productivity of tilted panel in membrane bioreactor.

Membrane fouling is a major challenge in membrane bioreactors (MBRs) and its effective handling is the key to improve their competitiveness. Tilting panel system offers significant improvements for fouling control but is strictly limited to one-sided panel. In this study, we assess a two-way switch tilting panel system that enables two-sided membranes and project its implications on performance and energy footprint. Results show that tilting a panel improves permeance by up to 20% to reach a plateau flux thanks to better contacts between air bubbles and the membrane surface to scour-off the foulant. A plateau permeance could be achieved at aeration rate of as low as 0.90 l min-1, a condition untenable by vertical panel even at twice of the aeration rate. Switching at short periods (<5min) can maintain the hydraulic performance as in no-switch (static system), enables application of a two-sided switching panel. A comparison of vertical panel under 1.80 l min-1 aeration rate with a switching panel at a half of the rate, switched at 1 min period shows ≈10% higher permeance of the later. Since periodic switching consumes a very low energy (0.55% of the total of 0.276 kWh m-3), with reduction of aeration by 50%, the switching tilted panel offers 41% more energy efficient than a referenced full-scale MBR (0.390 kWh m-3). Overall results are very compelling and highly attractive for significant improvements of MBR technologies.

Tackling membrane fouling in microalgae filtration using nylon 6,6 nanofiber membrane.

Microalgae technology, if managed properly, has promising roles in solving food-water-energy nexus. The Achilles' heel is, however, to lower the costs associated with cultivation and harvesting. As a favorable technique, application of membrane process is strongly limited by membrane fouling. This study evaluates performance of nylon 6,6 nanofiber membrane (NFM) to a conventional polyvinylidene fluoride phase inverted membrane (PVDF PIM) for filtration of Chlorella vulgaris. Results show that nylon 6,6 NFM is superhydrophilic, has higher size of pore opening (0.22 vs 0.18 µm) and higher surface pore density (23 vs 18 pores/µm2) leading to higher permeance (1018 vs 493 L/m2hbar) and better fouling resistant. Such advantages help to outperform the filterability of PVDF PIM by showing much higher steady-state permeance (286 vs 120 L/m2hbar), with comparable biomass retention. In addition, unlike for PVDF PIM, imposing longer relaxation cycles further enhances the performance of the NFM (i.e., 178 L/m2hbar for 0.5 min and 236 L/m2hbar for 5 min). Overall findings confirm the advantages of nylon 6,6 NFM over the PVDF PIM. Such advantages can help to reduce required membrane area and specific aeration demand by enabling higher flux and lowering aeration rate. Nevertheless, developments of nylon 6,6 NFM material with respect to its intrinsic properties, mechanical strength and operational conditions of the panel can still be explored to enhance its competitiveness as a promising fouling resistant membrane material for microalgae filtration.

Comparative analysis of first-year fingolimod and natalizumab drug discontinuation among Swedish patients with multiple sclerosis.

BACKGROUND: Natalizumab (NTZ) and fingolimod (FGL) are mainly used second line in relapsing-remitting multiple sclerosis (MS), although pivotal trials included mainly treatment-naïve patients. OBJECTIVE: This study aims to provide real-world data on safety and discontinuation rates. METHODS: Using IMSE, a drug monitoring registry for all newer MS drugs in Sweden, we analysed differences in baseline characteristics and 1-year drug survival for patients registered 2011-2013, initiating treatment with NTZ (n=640) or FGL (n=876). Among FGL initiators, n=383 (44%) had previously used NTZ (FGL(afterNTZ)). RESULTS: Compared with NTZ, the FGL cohort was older and more often male (36/38 years, 24%/33% males). Baseline Expanded Disability Status Scale was similar across groups, but MS Severity Score was higher in NTZ patients, and Symbol Digit Modalities Test and MS Impact Scale (MSIS-29) was higher in FGL(afterNTZ) versus FGL(NTZ-naïve) patients. Proportion on drug after 1 year was high, NTZ=87%, FGL(NTZ-naïve)=83% and FGL(afterNTZ)=76%. Adverse events was the most frequent reason for discontinuing FGL (FGL(NTZ-naïve)=9%, FGL(afterNTZ)=12%), and was significantly higher than on NTZ (3%). In contrast, the proportion of patients stopping treatment due to lack of effect was more similar: NTZ=4%, FGL(NTZ-naïve)=3%, FGL(afterNTZ)=8%. CONCLUSION: FGL and NTZ were both well tolerated, but FGL less so than NTZ, especially in patients switching to FGL from NTZ. Group differences were not explained by differences in recorded baseline characteristics.

Induced pluripotent stem cells: history, properties and potential applications.

The development of induced pluripotent stem cells (iPSCs) has been met with much enthusiasm and hailed as a breakthrough discovery by the scientific and research communities amidst the divisive and ongoing debates surrounding human embryonic stem cells (hESC) research. The discovery reveals the fact that embryonic pluripotency can be generated from adult somatic cells by the induction of appropriate transcriptional factor genes essential for maintaining the pluripotency. They provide an alternative source for pluripotent stem cells, thus representing a powerful new research tool besides their potential application in the field of regenerative medicine. In this review, the historical background of iPSCs generation will be discussed together with their properties and characteristics as well as their potential therapeutic applications.

Inhibition of Activin A suppressed tumor necrosis factor-α secretion and improved histopathological conditions in malarial mice.

Malaria infection still remains as one of the most prominent parasitic diseases afflicting mankind in tropical and subtropical regions. The severity of malaria infection has often been associated to exuberant host immune inflammatory responses that could possibly lead to severe immunopathological conditions and subsequent death of host tissues. Activin A is a protein belonging to the transforming growth factor-beta (TGF-ß) family that regulates multiple physiological processes and pathological-associated diseases. The biological roles of activin A have been associated with manipulation of inflammation-related processes and modulation of host immune responses. This implies that activin A protein could play a role in malaria pathogenesis since malaria infection has been closely linked to severe immune responses leading to death, However, the actual in vivo role of activin A in malaria infection remains elusive. Hence, this study was undertaken to investigate the involvement of activin A in malaria infection as well as to assess the modulating effects of activin A on the cytokine releases (TNF-α, IFN-γ and IL-10) and histopathological changes in major affected organs (kidney, liver, lung, brain and spleen) in malarial mice infected with Plasmodium berghei ANKA. Our results showed that the concentrations of plasma activin A were significantly increased in malarial mice throughout the study periods. Also. the systemic activin A level was positively correlated with malaria parasitemia. This indicates that activin A could play a role in malaria pathogenesis and malaria parasitemia development. Plasma TNF-α, IFN-γ and IL-10 cytokine levels were significantly increased in malarial mice at day-5 post infection, suggesting that these cytokines attributed to severe malaria pathogenesis. Histopathological features such as sequestration of parasitized red blood cells (pRBCs) and hemozoin formation were amongst the most common pathological conditions observed in tissues of major affected organs (kidney, liver, lung, brain and spleen) in malarial mice. Neutralization of activin A production via recombinant mouse activin RIIA Fc chimera (rmActivin RIIA Fc chimera) had significantly reduced the parasitemia levels in malarial mice. The release of TNF-α cytokine was significantly reduced as well as the sequestration of parasitized pRBCs and hemozoin formation in major affected organs in malarial mice were also alleviated following inhibition of activin A production. Overall, this preliminary study suggests that activin A could play an immune modulation role in malaria pathogenesis through modulation of TNF-α release that benefits host from severe pathological destructions provoked by intensified inflammatory responses. Further studies are warranted to elucidate the precise mechanism of immune modulation mediated by activin A and its associated immune-modulation mediators in regulating the inflammatory responses elicited during the course of malaria infection.

Potential application of biomass derived graphene for COVID-19 pandemic.

Since the emergence of the novel coronavirus disease (COVID-19) pandemic, intense research has been carried out to find the effective vaccine. However, this issue remains as a global challenge. Graphene has captured various attention due to promising antimicrobial and antiviral applications, hydrophobic characteristic and superior electrical conductivity. Recently, biomass derived graphene also promises great opportunity to combat the spread COVID-19. In this paper, we demonstrated the ability and role of biomass derived graphene as superhydrophobic coating, biosensors and disinfectant in the fight against COVID-19.

ABO-Incompatible Living-Donor Kidney Transplantation in a Developing Country: A Multicenter Experience in Malaysia.

Malaysia has a low deceased-donor donation rate and has not embarked on a paired kidney exchange program; therefore, ABO-incompatible and HLA-incompatible transplantation remain the main contributor to the sustainability of the national kidney transplantation (KT) program. There were 26 cases of ABO-incompatible KTs performed from 2011 to 2018 in 3 major transplant centers, namely, Hospital Kuala Lumpur, University Malaya Medical Centre, and Prince Court Medical Centre. We collected perioperative and follow-up data through June 2019. The desensitization protocol varies and is center specific: the localized Japanese protocol and Swedish protocol with a target anti-A/B isoagglutinin titer of 16 or 32 on the day of transplant. The induction and tacrolimus-based maintenance protocol was nearly identical. The median follow-up time was 62.3 months (interquartile range, 37.0-79.7). Fifteen subjects had the highest predesensitization anti-A/B titer of ≥32 (57.7%). The acute cellular rejection and antibody-mediated rejection incidence were 12.5% (3 cases) and 8.3% (2 cases), respectively. Patient, graft, and death-censored graft survival rates were 96.2%, 92.3%, and 96.0%, respectively, 1 year post-living-donor KT (LDKT) and 96.2%, 87.2%, and 90.7%, respectively, 5 years post-LDKT. Our experience shows that ABO-incompatible LDKT using a suitable desensitization technique could be a safe and feasible choice for LDKT even with varied desensitization regimens for recipients with relatively high baseline isoagglutinin titers.

An improved simplified rules Fuzzy Logic Speed Controller method applied for induction motor drive.

Fuzzy Logic Speed Controller (FLSC) has been widely used for motor drive due to its robustness and its non-reliance to real plant parameters. However, it is computationally expensive to be implemented in real-time and prone to the fuzzy rules' selection error which results in the failure of the drive's system. This paper proposes an improved simplified rules method for Fuzzy Logic Speed Controller (FLSC) based on the significant crisp output calculations to address these issues. A systematic procedure for the fuzzy rules reduction process is first described. Then, a comprehensive evaluation of the activated crisp output data is presented to determine the fuzzy dominant rules. Based on the proposed method, the number of rules was significantly reduced by 72%. The simplified FLSC rule is tested on the Induction Motor (IM) drives system in which the real-time implementation was carried out in the dSPACE DS1103 controller environment. The simulation and experimental results based on the proposed FLSC have proved the workability of the simplified rules without degrading the motor performance.

Development patterns of necrophagous flies infesting rabbit carcasses decomposing in Mount Kapur Cave and its surrounding primary forest in Kuching, Sarawak.

In addition to the scarcity of forensic entomology baseline data on oviposition of necrophagous insects and completion of their life cycles in the Borneo region, similar data derived from caves remain unreported. Since entomological baseline data can differ from one biogeoclimatic region to another, the lack of such data would limit the practical values of applying entomological evidence in estimating minimum postmortem interval (mPMI). Therefore, this present research that investigated oviposition and completion of life cycles of necrophagous flies infesting rabbit carcasses decomposing in Mount Kapur Cave and its surrounding forest habitat in Kuching, Sarawak merits forensic consideration. In general, 13 taxa of necrophagous flies were identified viz. Hypopygiopsis violacea, Hypopygiopsis fumipennis, Hemipyrellia ligurriens, Hemipyrellia tagaliana, Chrysomya megacephala, Chrysomya villeneuvi, Chrysomya rufifacies, Chrysomya chani, Chrysomya pinguis, Chrysomya nigripes, Ophyra spinigera and Ophyra chalcogaster, as well as unidentified Sarcophagidae. In addition, Hyp. violacea and Hyp. fumipennis were the two earlier necrophagous flies that oviposited in all rabbit carcasses decomposing in both habitats. While all these necrophagous flies were observed infesting carcasses in Mount Kapur Cave, Hem. ligurriens and Hem. tagaliana were not found infesting carcasses in the surrounding forest habitat. Complete life cycles for six and five different necrophagous fly species were successfully observed in Mount Kapur Cave and its surrounding forest habitat, respectively. Significant delay in oviposition, as well as longer durations for completing the life cycles in several necrophagous fly species were observed in Mount Kapur Cave when compared with those of surrounding forest habitat (p < 0.05). These findings deserve consideration as the first ever forensic empirical baseline data on oviposition and completion of life cycles for necrophagous flies in Sarawak as well as in a cave habitat, in view of its practical values for estimating mPMI for forensic practical caseworks.

Determining the relationship between three-dimensional power Doppler data and true blood flow characteristics: an in-vitro flow phantom experiment.

OBJECTIVES: Three-dimensional (3D) ultrasound can be used to acquire power Doppler data which can be quantified to give an objective impression about blood flow within a tissue or organ. Proprietary software can be used to calculate three indices of vascularity: vascularization index (VI), flow index (FI) and vascularization flow index (VFI). Although these indices appear to have a predictive value in the clinical setting and can be shown to vary between different patient populations and over time within the same population, their relationship with true in-vivo blood flow characteristics has not been established. The objective was to examine the effect of flow rate, vessel number, attenuation and erythrocyte density on these indices. METHODS: A computer-driven flow phantom was used to continuously pump a nylon particle-based blood mimic (Orgasol(trade mark)) around a closed system through three different ultrasound test tanks. These tanks were designed specifically for these experiments and contained C-Flex(trade mark) tubing, in a variety of arrangements, encased in an agar-based tissue mimic. The test tanks were insonated with a modified 3D transvaginal 4-8-MHz ultrasound transducer and 3D power Doppler data were then acquired over a graduated series of flow rates, depths and blood mimic concentrations. Regression analysis was used to determine the resulting relationships. RESULTS: The VI increased linearly with an increase in flow rate (P < 0.05), whereas the FI increased in a cubic manner with a more rapid initial increase (P < 0.05). The VI demonstrated a similar linear increase with an increase in the erythrocyte mimic density (P < 0.05), whereas the FI increased markedly with a small change in erythrocyte mimic density and then plateaued (P < 0.01). There was a significant reduction in each index as the distance between the transducer and vessel increased (P < 0.05). Patterns similar to those seen in relation to the change in flow rate were evident, with a more linear relationship between depth and the VI and VFI than between depth and the FI, although the FI remained relatively constant and was not significantly affected by distance from the transducer until a depth of 55 mm was reached. Although a positive linear relationship was seen between vessel number and VI and VFI (P < 0.05) the FI demonstrated a very different and complex, cubic relationship (P < 0.001), increasing linearly until a maximum of three vessels were present when it decreased, and no overall correlation was seen (P > 0.05). CONCLUSIONS: The VI, FI and VFI are all significantly affected by volume flow, attenuation, vessel number and erythrocyte density, but in different ways. The VI and VFI seem to have a more predictable relationship, whereas the FI often demonstrates a more complex cubic relationship that is not always logical. Further work is required to establish the effect of other confounding parameters before valid conclusions may be made and a better understanding of 3D power Doppler ultrasound imaging achieved.

Evaluation of the effect of machine settings on quantitative three-dimensional power Doppler angiography: an in-vitro flow phantom experiment.

OBJECTIVES: Three-dimensional (3D) ultrasound is being used increasingly to acquire and subsequently quantify power Doppler data within the clinical setting. One proprietary software package calculates three 3D vascular indices: the vascularization index (VI), the flow index (FI), and the vascularization flow index (VFI). Our aim was to evaluate how different settings affect the Doppler signal in terms of its quantification by these three indices within a 3D dataset. METHODS: A computer-driven 'flow phantom' was used to continuously pump a nylon particle-based blood mimic (Orgasol(trade mark)) around a closed system through a C-flex(trade mark) tube embedded in an agar-based tissue mimic. The test tanks were insonated with a modified 3D transvaginal 4-8-MHz ultrasound transducer (V530D) and power Doppler data were acquired over a series of different settings. Each experiment involved the manipulation of just one Doppler setting in order to study it in isolation. RESULTS: As expected, all of the power Doppler settings, when altered, were found to effect significant changes (P < 0.05) in the VI, FI and VFI. The gain and signal power had the greatest effect, producing no Doppler signals at the lowest settings and the highest recordable indices at the maximum settings. The pulse repetition frequency (PRF) was the next most influential setting but a Doppler signal was seen and measurable at all of the different settings. The other Doppler settings had a much less profound effect on the vascular indices, with subtle but significantly different measures across the full range of settings. The speed of data acquisition was also found to affect the vascular indices, all of which were reduced when the fast mode was used although the only significant effect was on the VFI. CONCLUSIONS: The VI, FI and VFI are all affected significantly by variations in power Doppler settings and by the speed of acquisition. The gain and signal power have the greatest effect on the power Doppler signal, followed closely by the PRF. The other settings and speed of acquisition also influence the signal, but to a much lesser degree. It is essential to maintain Doppler settings if any meaningful comparisons are to be made within and between subjects.