Oil droplets and solid particles removal using circular separator with inclined coalescence mediums: comparison between co-current and counter-current flow

This research investigated the effects of co- and counter-current flow patterns on oil-water-solid separation efficiencies of a circular separator with inclined coalescence mediums. Oil-water-solid separations were tested at different influent concentrations and flowrates. Removal efficiencies increased as influent flowrate decreased, and their correlationship can be represented by power equations. These equations were used to predict the required flowrate, Q(ss50), for a given influent suspended solids concentration C(iss) to achieve the desired effluent suspended solids concentration, C(ess) of 50 mg/L, to meet environmental discharge requirements. The circular separator with counter-current flow was found to attend removal efficiencies relatively higher as compared to the co-current flow. As compared with co-current flow, counter-current flow Q(ss50) was approximately 1.65 times higher than co-current flow. It also recorded 13.16% higher oil removal at influent oil concentration, C(io) of 100 mg/L, and approximately 5.89% higher TSS removal at all influent flowrates. Counter-current flow's better removal performances were due to its higher coalescing area and constant interval between coalescence plate layers.

Utility of SPECT/CT with Meckel's scintigraphy

Meckel's diverticulum is a relatively common source of gastrointestinal tract morbidity in children. Individuals may present with symptoms of lower gastrointestinal tract bleeding, bowel obstruction or diverticulitis. Technetium-99 m pertechnetate scintigraphy is used to demonstrate those Meckel's diverticula that contain heterotopic gastric mucosa. We present a case of an adolescent male patient with rectal bleeding and suspected Meckel's diverticulum where the use of SPECT/CT fusion imaging provided valuable diagnostic information and prevented a false-negative study.

Broad spectrum of cytokine abnormalities in panic disorder and posttraumatic stress disorder

BACKGROUND

Proinflammatory cytokines have been reported to be elevated in individuals experiencing chronic stress as well as in those with major depressive disorder. Much less is known about cytokines in anxiety disorders such as posttraumatic stress disorder (PTSD) and panic disorder (PD). We hypothesized that PD and PTSD would be associated with a generalized proinflammatory cytokine signature.

METHOD

We utilized Luminex technology to examine 20 cytokines and chemokines in serum from 48 well-characterized individuals with a primary DSM-IV PD or PTSD diagnosis, and 48 age- and gender-matched healthy controls. We conservatively employed a Bonferroni correction for multiple testing (alpha=.05/20=.0025).

RESULTS

Individuals with primary PTSD or PD had significantly elevated median peripheral cytokine levels for 18 of 20 different cytokines compared to age- and gender-matched healthy controls (all P<.0025). To assess for the presence of a generalized proinflammatory state, we also examined the proportion of subjects with detectable levels of at least six of nine common proinflammatory cytokines and chemokines (IL-6, IL-1alpha, IL-1beta, IL-8, MCP-1, MIP-1alpha, Eotaxin, GM-CSF, and IFN-alpha). For men and women, 87% of anxiety patients had six or more detectable levels of these proinflammatory cytokines, compared with only 25% of controls (Fisher's Exact Test (FET) P=.000). Confirmatory analysis of the subset of individuals without current psychiatric medication use or comorbid depression was of comparable significance.

CONCLUSIONS

These findings suggest that a generalized inflammatory state may be present in individuals with PD or PTSD.

Hybrid SPECT-CT and PET-CT imaging of differentiated thyroid carcinoma

Hybrid imaging modalities such as radioiodine single photon emission CT with integrated CT ((131)I SPECT-CT) and 2-(fluorine-18)-fluoro-2-deoxy-D-glucose positron emission tomography with integrated CT (FDG PET-CT) allow the rapid and efficient fusion of functional and anatomic images, and provide diagnostic information that may influence management decisions in patients with differentiated thyroid carcinoma (DTC). Diagnostic localisation and therapy of these tumours are dependent upon their capacity to concentrate radioiodine ((131)I) via uptake through the sodium-iodide symporter and retention within the tumour. The prognosis for most patients with DTC is favourable, although controversy exists regarding the role of post-operative (131)I therapy in patients at low-risk for disease. Accurate identification of functional thyroid tissue (benign or malignant) using diagnostic (131)I planar scintigraphy complemented by SPECT-CT imaging enables the completion of post-operative staging and patient risk stratification prior to (131)I therapy administration. In patients with non-iodine-avid tumours (negative (131)I scan but elevated thyroglobulin indicative of persistent or recurrent disease), FDG PET-CT is used to identify tumours with enhanced glucose metabolism and to localise the source of thyroglobulin production. The CT component of this hybrid technology provides anatomic localisation of activity and allows CT-based attenuation correction of PET images. Images from 15 patients illustrate the applications of (131)I SPECT-CT and FDG PET-CT.

Scintigraphic imaging of adrenal disease

The nuclear medicine approach to adrenal imaging spans six decades with radiopharmaceuticals designed to take advantage of the unique characteristics of the functional divisions of the gland, substrate accumulation, hormone biosynthesis, receptor-ligand interactions and pharmacologic manipulation of mechanisms of central control. The recent introduction of hybrid imaging techniques that combine high resolution anatomy with the functional maps derived from the scintigraphic images is yet another step in the evolution of integrated imaging techniques that can be used to diagnostic advantage in the evaluation of disease of the adrenal gland.

A detailed examination of cytokine abnormalities in Major Depressive Disorder

Recent technological advances offer an opportunity to further elucidate the complex cytokine network in Major Depressive Disorder (MDD). Twenty cytokines were simultaneously assessed in 49 individuals with MDD and 49 age and gender matched controls. Multiple pro-inflammatory and two anti-inflammatory cytokines were significantly elevated in the MDD sample, including an antidepressant naïve subset. These data support a generalized chronic inflammatory state in MDD, and implicate additional cytokines and chemokines previously linked to cardiovascular disease.

Evaluation of the NK2 homeobox 1 gene (NKX2-1) as a Hirschsprung's disease locus

Hirschsprung's disease (HSCR, colonic aganglionosis) is an oligogenic entity that usually requires mutations in RET and other interacting loci. Decreased levels of RET expression may lead to the manifestation of HSCR. We previously showed that RET transcription was decreased due to alteration of the NKX2-1 binding site by two HSCR-associated RET promoter single nucleotide polymorphisms (SNPs). This prompted us to investigate whether DNA alterations in NKX2-1 could play a role in HSCR by affecting the RET-regulatory properties of the NKX2-1 protein. Our initial study on 86 Chinese HSCR patients revealed a Gly322Ser amino acid substitution in the NKX2-1 protein. In this study, we have examined 102 additional Chinese and 70 Caucasian patients and 194 Chinese and 60 Caucasian unselected, unrelated, subjects as controls. The relevance of the DNA changes detected in NKX2-1 by direct sequencing were evaluated using bioinformatics, reporter and binding-assays, mouse neurosphere culture, immunohistochemistry and immunofluorescence techniques. Met3Leu and Pro48Pro were identified in 2 Caucasian and 1 Chinese patients respectively. In vitro analysis showed that Met3Leu reduced the activity of the RET promoter by 100% in the presence of the wild-type or HSCR-associated RET promoter SNP alleles. The apparent binding affinity of the NKX2-1 mutated protein was not decreased. The Met3Leu mutation may affect the interaction of NKX2-1 with its protein partners. The absence of NKX2-1 expression in mouse but not in human gut suggests that the role of NKX2-1 in gut development differs between the two species. NKX2-1 mutations could contribute to HSCR by affecting RET expression through defective interactions with other transcription factors.

Quiescent subpopulations of human CD34-positive hematopoietic stem cells are preferred targets for stable recombinant adeno-associated virus type 2 transduction

We have previously demonstrated recombinant adeno-associated viral (rAAV) transduction of human CD34(+) hematopoietic stem cells (HSCs) capable of serial engraftment in vivo. Here we evaluated the capacity of rAAV2 to mediate gene transfer into nondividing, quiescent, primitive CD34(+) cells subdivided on the basis of metabolic, mitotic, and phenotypic properties. Results revealed that CD34(+)CD38() marrow cells are the most quiescent, exist primarily in G(0) at isolation and are the only population to remain nondividing during the entire exposure to free rAAV. Despite significant differences in the extended clonogenic capacities of CD34(+) subsets in stromal cultures, the frequency of rAAV marking of colonies derived from primitive progenitors was similar in all three populations, suggesting that both primitive and more differentiated progenitors were initially transduced at equal levels. After transduction, episomal and integrated rAAV genomes were detected in all CD34(+) subsets. However, the more quiescent cells displayed higher levels of integrated rAAV than did rapidly dividing cells. Importantly, stable long-term integration was observed only in the most primitive, quiescent CD34(+)CD38(-) subset, indicating that this HSC compartment comprises the preferred substrate for stable rAAV2 transduction. Previously described rate limitations to transgene expression were observed in transduced CD34(+) cells and could be overcome by tyrphostin pretreatment, which resulted in augmented second-strand synthesis. These results represent the first demonstration of rAAV-mediated gene transfer to primitive, quiescent human CD34(+)CD38(-) stem cells and reveal that nondividing CD34(+)CD38(-) HSCs are the optimal CD34(+) targets for rAAV transduction.

The effect of Nd:YAG laser posterior capsulotomy on stereoacuity

AIMS

To assess the effect of Nd:YAG laser posterior capsulotomy in the context of unilateral posterior capsular opacification (PCO) on spatial acuity, contrast sensitivity, and stereoacuity.

METHODS

This prospective study involved 60 consecutive subjects with unilateral PCO. The aforementioned parameters of visual function were assessed immediately prior and 3 weeks subsequent to unilateral posterior capsulotomy.

RESULTS

In eyes that underwent laser posterior capsulotomy, the median spatial acuity (log minimum angle of resolution (MAR)) improved from 0.34 (20/44) to 0.16 (20/29) (P=<0.001, Wilcoxon test), while the median contrast sensitivity improved from 22.4 to 35.5 dB (P=<0.001, Wilcoxon test) after posterior capsulotomy. Fellow eyes exhibited negligible change in these visual parameters. The median stereoacuity improved from 240 to 60 s of arc (P=<0.001, Wilcoxon test).

CONCLUSION

In the context of unilateral opacification of the posterior capsule, Nd:YAG laser posterior capsulotomy affords significant improvement in stereoacuity, apparently in excess of improvements in spatial acuity and contrast sensitivity. Routine measurement and documentation of these parameters of visual function is recommended especially when subjective visual disability appears disproportionate with impairment of spatial acuity.

Molecular phylogeny of modern coxsackievirus A16

A phylogenetic analysis of VP1 and VP4 nucleotide sequences of 52 recent CVA16 strains demonstrated two distinct CVA16 genogroups, A and B, with the prototype strain being the only member of genogroup A. CVA16 G-10, the prototype strain, showed a nucleotide difference of 27.7-30.2% and 19.9-25.2% in VP1 and VP4, respectively, in relation to other CVA16 strains, which formed two separate lineages in genogroup B with nucleotide variation of less than 13.4% and less than 16.3% in VP1 and VP4, respectively. Lineage 1 strains circulating before 2000 were later displaced by lineage 2 strains.

Myocardial Fiber Length Mapping with MR Diffusion Tensor Imaging

Diffusion tensor MRI is emerging as a rapid, nondestructive method to map myocardial fiber organization. A precise biological description of myocardial fiber performance requires knowledge of four variables: length, force, velocity and time. However, study of quantification of myocardial fiber length is lacking. The current study aims to show myocardial fiber length maps of formalin-fixed heats. Diffusion tensor MRI with medium diffusion resolution (15 directions) was performed in one isolated pig heart. Fiber length maps were investigated in multiple short-axis slices. The results provide supplementary information of myocardial fiber organization. To our knowledge, the present study is the first report of the myocardial fiber length mapping.

Differential expression of survivin splice isoforms in medulloblastomas

Survivin, a member of the inhibitor of apoptosis protein family, is implicated in the dysregulation of apoptosis in human cancers. Survivin and survivin-deltaEx3, one of its two alternatively spliced isoforms, confer anti-apoptotic activities in human tumours, while survivin-2B antagonizes such anti-apoptotic properties. The current study was undertaken to examine the mRNA expression of survivin isoforms and their correlation with clinical staging and outcome in 20 medulloblastoma (MB) tumours, three MB cell lines and normal brain tissues (a foetal and an adult cerebellum) by densitometry scanning of 32p-dCTP incorporated reverse transcription polymerase chain reaction (RT-PCR) products and quantitative real-time PCR. Our results showed that the normal adult brain only expressed low levels of survivin-deltaEx3 mRNA, while the foetal brain expressed all three isoforms, with wild-type survivin as the dominant transcript. All three survivin isoforms were detected in all the MB cell lines and tumours analysed. Immunohistochemical staining also demonstrated survivin protein expressions in all five paraffin-embedded MBs, with predominant nuclear localization. Although overexpressions of survivin were not associated with the presence of metastatic MB or tumour histological subtypes, elevated expressions of survivin-deltaEx3 were significantly associated with progressive/recurrent tumours (P-value = 0.024). Our data demonstrated that overexpression of survivin mRNA is a common feature in MBs, may contribute to their anti-apoptosis properties and clinical behaviours, and predicts a poor clinical outcome, independent of clinical staging or tumour histology.

Neonatal fungal ventriculitis

Intracranial fungal infection is increasingly seen in the neonatal intensive care setting, with premature infants at greatest risk. We report a case of fungal ventriculitis in an extremely low birth weight neonate due to Candida species. Cranial sonographic examination revealed extensive ventricular stranding with complete resolution in response to therapy.

Autoimmune polyendocrinopathy type II in a Chinese patient

Autoimmune polyendocrinopathy type II is rarely reported in Chinese patients. A 42-year-old Chinese woman with a history of Hashimoto's thyroiditis and hypogonadotropic hypogonadism presented with pneumonia. During hospitalisation, she went into an adrenal crisis and diabetic ketoacidosis. Subsequent dynamic hormonal tests revealed primary and secondary adrenal insufficiency. She also had pernicious anaemia, possible alopecia areata, and myasthenia gravis. This constellation of multiple endocrine and non-endocrine disorders led to the diagnosis of autoimmune polyendocrinopathy type II. As the syndrome can be lethal, it is important to maintain a high index of suspicion, enabling early diagnosis and the appropriate replacement therapy, to ensure a successful outcome.

Breakage of intramedullary femoral guide rod during total knee arthroplasty: a case report

We report a rare complication during primary total knee arthroplasty. An intramedullary femoral guide rod was broken during insertion. The broken part jammed into the isthmus of the femur. An initial attempt to push the broken rod via the proximal femur by a guide wire to the distal femur was unsuccessful because the broken rod was lodged in the isthmus. Ultimately, the isthmus was opened using a flexible 9-mm end-cutting reamer, and the broken rod was pushed down to the distal femoral entry site in an antegrade fashion under image intensification. Selecting a more medial entry site on the intercondylar notch with a smaller valgus cutting angle and using a shorter guide rod can avoid such a breakage.

Medications used to manage supraventricular tachycardia in the infant a North American survey

Supraventricular tachycardia is the most common pediatric arrhythmia, but there is no consensus and little evidence to guide its treatment. We sent a questionnaire to pediatric cardiologists in North America to assess the current practice pattern. Of 1534 surveys mailed, 352 (23%) were returned and 295 (19%) had complete data for analysis. In the acute setting, 11 different medications were chosen. The most commonly used in the infant without preexcitation were digoxin (42%), procainamide (21%), esmolol (13%), propranolol (10%), and amiodarone (8%). In the infant with preexcitation, propranolol (34%), procainamide (23%), esmolol (17%), amiodarone (11%), and digoxin (6%) were used. In the chronic setting, 8 different medications were chosen. The most commonly used in this scenario were digoxin (52%), propranolol (33%), amiodarone (4%), and sotalol (3%). In the infant with preexcitation, propranolol (70%), amiodarone (6%), digoxin (6%), atenolol (6%), and flecainide (5%) were used. Medication choices were influenced by additional electrophysiology training and preexcitation. Digoxin was used less in the setting of preexcitation. There are no comparative trials to explain the different medication choices. Although a number of medications may be efficacious, a randomized clinical trial is needed to offer further guidance.

Volar fixation of dorsally displaced distal radial fracture using locking compression plate

PURPOSE

To evaluate the functional and radiological results of treating unstable fractures of the dorsal distal radius with a volar locking plate.

METHODS

Dorsally displaced distal radial fractures in 30 patients (11 men and 19 women; mean age, 58.6 years) were fixed by volar locking compression plate and followed up for a minimum of one year.

RESULTS

At final functional assessment, 24 patients achieved excellent and 5 achieved good outcomes, with one patient exhibiting fair results. Radiological scores demonstrated 22 excellent and 8 good outcomes. No nonunion or infection occurred.

CONCLUSION

Volar locking compression plating is a safe and effective treatment for unstable fractures of the dorsal distal radius.

Recombinant AAV2 transduction of primitive human hematopoietic stem cells capable of serial engraftment in immune-deficient mice

A recombinant AAV2 (rAAV2) vector encoding antisense RNA to HIV-1 transactivating region (TAR) was evaluated for transduction of human cord blood CD34+CD38- hematopoietic stem cells (HSC) capable of serial engraftment in nonobese diabetic (NOD)/severe combined immunodeficient (SCID) mice. Results revealed long-term multilineage marking in primary and secondary recipients, and significantly, an enrichment of transduced cells in secondary hosts, indicating efficient transduction of multipotential self-renewing HSC. These results were confirmed by the persistence of rAAV marking of clonogenic progenitors in serial analyses of recipient marrow. Upon HIV-1 challenge, the macrophage progeny of transduced CD34+ cells expressed antisense RNA and exhibited sustained and significant inhibition of virus replication as compared with controls in every donor tested, without selective pressure. This study represents a clear in vivo demonstration of efficient rAAV2 transduction of human HSC.

Significance of the Hygiene Charter towards different sectors in Hong Kong

The occurrence of SARS in March 2003 has resulted in an increased interest, worldwide in emerging infectious diseases. The SARS experience provided us a lesson on the importance of promoting hygienic practices among individuals and different working sectors. In Hong Kong, a voluntary organization called the UNITE proposed a Hygiene Charter which aimed at taking hygiene to new levels. This action has been supported by individuals and different sectors including the Personal and Family, Management, Buildings, Catering, Education, Finance and Commercial, Industrial, Medical and Health, Public Transportation, Social Welfare, Sports and Culture and Tourism. As promotion and maintenance of environmental health requires input from different sectors, the signing of the Hygiene Charter provides an opportunity for individuals and the public to show their pledge and commitment to good hygiene practices. As a result, with environment improvement and good infectious disease control measures, prevention of epidemics of infectious diseases is deemed to be possible.

Performance of Large-Size Superconducting Coil in 0.21T MRI System

A high-temperature superconductor (HTS) was used on magnetic resonance imaging (MRI) receiver coils to improve image quality because of its intrinsic low electrical resistivity. Typical HTS coils are surface coils made of HTS thin-film wafers. Their applications are severely limited by the field of view (FOV) of the surface coil configuration, and the improvement in image quality by HTS coil is also reduced as the ratio of sample noise to coil noise increases. Therefore, previous HTS coils are usually used to image small in vitro samples, small animals, or peripheral human anatomies. We used large-size HTS coils (2.5-, 3.5-, and 5.5-in mean diameter) to enhance the FOV and we evaluated their performance through phantom and human MR images. Comparisons were made among HTS surface coils, copper surface coils, and cool copper surface coils in terms of the signal-to-noise ratio (SNR) and sensitivity profile of the images. A theoretical model prediction was also used to compare against the experimental result. We then selected several human body parts, including the wrist, feet, and head, to illustrate the advantage of HTS coil over copper coil when used in human imaging. The results show an SNR gain of 200% for 5.5-in HTS coil versus same size copper coils, while for 2.5- and 3.5-in coils it is 250%. We also address the various factors that affect the performance of large size HTS coils, including the coil-to-sample spacing due to cryogenic probe and the coil-loading effect.

Evaluation of pyrrolidin-2-imines and 1,3-thiazolidin-2-imines as inhibitors of nitric oxide synthase

Syntheses and evaluation of pyrrolidin-2-imines and 1,3-thiazolidin-2-imines as inhibitors of nitric oxide synthase (NOS) are discussed. An extensive SAR was established for pyrrolidin-2-imines class of compounds. The amidines came out as the most potent inhibitors in addition to displaying selectivity.