The major lung cancer-derived mutants of ERBB2 are oncogenic and are associated with sensitivity to the irreversible EGFR/ERBB2 inhibitor HKI-272

Mutations in the ERBB2 gene were recently found in approximately 2% of primary non-small cell lung cancer (NSCLC) specimens; however, little is known about the functional consequences and the relevance to responsiveness to targeted drugs for most of these mutations. Here, we show that the major lung cancer-derived ERBB2 mutants, including the most frequent mutation, A775insYVMA, lead to oncogenic transformation in a cellular assay. Murine cells transformed with these mutants were relatively resistant to the reversible epidermal growth factor receptor (EGFR) inhibitor erlotinib, resembling the resistant phenotype found in cells carrying the homologous mutations in exon 20 of EGFR. However, the same cells were highly sensitive to the irreversible dual-specificity EGFR/ERBB2 kinase inhibitor HKI-272, as were those overexpressing wild-type ERBB2. Finally, the NSCLC cell line, Calu-3, overexpressing wild-type ERBB2 owing to a high-level amplification of the ERBB2 gene were highly sensitive to HKI-272. These results provide a rationale for treatment of patients with ERBB2-mutant or ERBB2-amplified lung tumors with HKI-272.

Recent progress of moving-actuator type mechanical circulatory support systems: AnyHeart and T-PLS

The mechanical circulatory support system using moving-actuator mechanisms were developed by Seoul National University and Korea University. AnyHeart is a fully implanted pulsatile bi-ventricular assist device, and T-PLS is a pulsatile flow versatile extracorporeal life support system. Through lots of in-vitro and in-vivo experiments, the developed mechanical systems are faced to produce on commercial scale. This paper describes the recent progress of two mechanical circulatory support systems, AnyHeart and T-PLS.

Evaluation of the methods for pupil size estimation: on the perspective of autonomic activity

The purpose of This work is to find the optimal calculation method about pupil size to estimate an activity of autonomic nerve system. To evaluate its state, we have to calculate an accurate pupil size from the image of free-rotated and yawed eye for 5 minutes. But calculation of the pupil size from image takes a long time. So we suppose three methods which considered cost (time), accuracy and evaluate for each. 'Method' 1 is to calculate the vertical pupil diameter from images, 'method 2' is to calculate the pupil size from whole image (method 2-1; by binarization and method 2-2; by binarization with shape evaluation) and 'method 3', the most accurate method, is from three-dimensional transformation of pupil image. As a result, for seven subjects, each method is takes about 6, 44, 124, 311 minutes to evaluate five-minute images (300,000 pixels/frame, 30 frames/sec). Also, the result of correlation between the parameter Lf/Hf ratio of heart rate variability, commonly used method for estimate the state of autonomic nerve system, and it of pupil size variability is, for each case, 0.34, 0.2, 0.69, 0.69.

Development of an implantable intrathecal drug infusion pump

An intrathecal drug infusion system has been designed, manufactured and tested. The system is composed of a drug reservoir and a pump/controller assembly. The drug reservoir made of SUS316L is a negative pressure gas chamber enclosing a bellows type drug chamber. The pump/controller assembly includes a bacterial filter, a controller circuit board, a battery and a micropump, and is connected to a catheter for intrathecal infusion. The micropump implements a peristaltic pumping of the drug by a sequential motion of three pairs of cam and cam-follower. In vitro performance tests were conducted with prototypes.

Hibernoma: MRI features in eight consecutive cases

AIM

To describe the preoperative magnetic resonance imaging findings of eight histologically-proven cases of hibernoma.

MATERIALS AND METHODS

The site, size, and signal characteristics of eight consecutive hibernomas were retrospectively assessed on T1-weighted spin-echo and short T1 inversion recovery (STIR)/fat-saturated T2-weighted fast spin echo magnetic resonance images. Four patients also had gadolinium-enhanced fat-saturated T1-weighted spin echo imaging. Patient age and sex, and duration of symptoms were recorded.

RESULTS

Three female and five male patients with an average age 36 years (range 16-53 years) were included. Seven lesions occurred in the thigh, four in the anterior compartment and three in the posterior compartment. One lesion occurred superficial to the scapula. All cases demonstrated common magnetic resonance imaging findings of a well-defined, heterogeneous mass, slightly or clearly hypo-intense to subcutaneous fat on T1-weighted spin-echo images, with prominent thin low signal bands throughout the tumour. The lesions failed to fully suppress on STIR or fat-saturated T2-weighted images. Only one of the four contrast-enhanced studies demonstrated increased vascularity in the tumour.

CONCLUSION

The MRI findings of a lesion that is diffusely slightly hypointense to surrounding subcutaneous fat, should prompt the operator to consider hibernoma in the differential diagnosis.

Managing venous stenosis in vascular access for haemodialysis

The prevalence of end-stage renal disease in Singapore is high and rising with some 2,700 patients requiring haemodialysis in the year 2004. In tandem with the increasing prevalence of diabetes mellitus, the number of dialysis patients is projected to rise to nearly 6,000 in the year 2010, adding to the national healthcare costs. Diabetic nephropathy accounts for about 40 percent of patients starting dialysis in Singapore. There have been few studies regarding vascular access for haemodialysis, despite its great demand in the local population. These vascular access channels are far from perfect, and provide great challenges for the vascular surgeons, nephrologists and interventional radiologists on a constant basis. The concomitant vasculopathies in diabetic patients also increase the risk of morbidity related to vascular access interventions. This paper will review the current state of interventions and research associated with managing venous stenosis in renal vascular access for haemodialysis.

Self-assembled Al(x)Ga(1-x)N nanorods grown on Si(001) substrates by using plasma-assisted molecular beam epitaxy

Hexagonal Al(x)Ga(1-x)N nanorods were grown by plasma-assisted molecular beam epitaxy (PAMBE) on Si(001) substrates. The Al mole fraction was determined from x-ray diffraction (XRD) measurement and its value was varied from 0 to 15. It is found that, under group III-rich conditions, the growth rate of the Al(x)Ga(1-x)N nanorods decreases and the diameter increases due to the possibility of incorporation of aluminium and gallium. In order to study structural and optical properties, x-ray diffraction and cathodoluminescence (CL) measurements were carried out. The Al content (x) is calculated from these measurements and their values are compared.

Imaging the infrapatellar tendon in the elite athlete

Extensor mechanism injuries constitute a major cause of anterior knee pain in the elite athlete. Sonography and magnetic resonance imaging (MRI) are the imaging methods of choice when assessing the infrapatellar tendon. A comprehensive imaging review of infrapatellar tendon normal anatomy, tendinopathy, and partial/full-thickness tendon tears is provided. The value of imaging the infrapatellar tendon in clinical practice, including whether sonography can predict symptoms in asymptomatic athletes, is discussed. Acute avulsion fractures, including periosteal sleeve avulsion, and chronic avulsion injuries, including Sinding-Larsen-Johansson and Osgood-Schlatter syndromes, are shown. Mimics of infrapatellar tendon pathology, including infrapatellar plica injury, patellar tendon-lateral femoral condyle friction syndrome, and Hoffa's syndrome, are illustrated.

Immunohistochemical Localization of Glutamate in the Gerbil Main Olfactory Bulb Using an Antiserum Directed against Glutamate

Information on the localization and the roles of glutamate in the nervous system is becoming valuable because the axon terminals of the olfactory sensory neurons and the synapses of the mitral and tufted output cells appear to be glutamatergic. In this study, we have analysed the distribution of glutamate immunoreactivity in the main olfactory bulb (MOB) of the Mongolian gerbil using an antiserum directed against glutamate. Glutamate immunoreactivity in the MOB was present in the olfactory nerve layer (Onl), glomerular layer (GL), external plexiform layer (EPL) and mitral cell layer (ML), but not in the granule cell layer (GCL). Glutamate immunoreactivity detected in the Onl was thought to be terminal ramifications of glomeruli. Some neurons in the periglomerular region showed glutamate immunoreactivity. In the EPL, glutamate immunoreactivity was found in some neuronal somata (tufted cells) and processes. In addition, mitral cells in the ML were labelled by the glutamate antibody. The pattern of glutamate immunoreactivity in the mitral cells was similar to that in the tufted cells. In brief, glutamate in the gerbil MOB is the neurotransmitter used by primary afferents and output neurons.

Design of a Subcutaneous Vascular Access Device Using Ni-Ti SMA Clamps for Hemodialysis

A subcutaneous vascular access device which utilizes an Ni-Ti shape memory alloy (Ni-Ti SMA) spring, has been developed as a new method for subcutaneous vascular access in the treatment of hemodialysis patients. Until now, the connection between the SVAD and needle cannot be externally monitored, and the clamp must be opened and closed with a percutaneous needle by a nephrologist.

The SMA-SVAD accomplishes the opening and closing of its clamp using two Ni-Ti SMA springs, and a transcutaneous energy transmission system (TET) transmits energy to the Ni-Ti SMA springs without the need for percutaneous wires. Two SMA springs open and close the clamp of the SMA-SVAD, without affecting any of the other parts of the system. Wasted thermal energy is reduced to minimal values via electrical regional heating methods. The state of the SMA-SVAD can be monitored according to the amount of power consumed by the external energy transmitter.

In in-vitro experiments, when the clamp was opened and the pressure difference in the hemodialysis machine was set to 50 mmHg, water flow through SMA-SVAD reached 500 ml/min. The maximal surface temperatures of the SVAD and catheter were successfully maintained at proper levels (38~39°C), 2~3 degrees higher than the temperature of the surrounding tissues. The time elapsed from the initiation of energy transmission until the opening of the SMA clamp was 5 seconds.

Postmastectomy Radiotherapy Reduces Locoregional Recurrence in Elderly Women with High-risk Breast Cancer

AIMS

Clinical trials of adjuvant radiotherapy after mastectomy have largely excluded women aged 70 years or over, even though they comprise 30% of the breast cancer population. This study examined outcomes in elderly women with high-risk breast cancer treated with or without postmastectomy radiotherapy (PMRT).

MATERIALS AND METHODS

Data were analysed for 233 women aged 70 years or over with high-risk breast cancer (tumours > 5 cm or > or = 4 positive axillary nodes) treated with mastectomy and referred to the British Columbia Cancer Agency from 1989 to 1997. Tumour and treatment characteristics were compared between two cohorts: women treated with PMRT (n = 147) vs women treated without PMRT (n = 86). Univariate and multivariate analyses of 10-year Kaplan-Meier locoregional recurrence (LRR), distant recurrence, breast cancer-specific survival and overall survival were carried out.

RESULTS

Median follow-up time was 5.5 years. The distribution of tumour sizes was similar in the two groups. Compared with women treated without PMRT, higher proportions of women who underwent PMRT had four or more positive nodes (83% vs 67%, P = 0.01) and positive surgical margins (14% vs 4%, P = 0.02). Systemic therapy, used in 94% of women, was comparable in the two cohorts (P = 0.63). Elderly women treated with PMRT had significantly lower LRR compared with women treated without PMRT (16% vs 28%, P = 0.03). No differences in distant recurrence, breast cancer-specific survival or overall survival were observed in the two treatment groups (all P > 0.05). On multivariate analysis, the omission of PMRT and the presence of high-grade histology were significant predictors of LRR, whereas an increasing number of positive nodes was significantly associated with distant recurrence and overall survival.

CONCLUSIONS

In women aged 70 years or over with tumours greater than 5 cm or four or more positive nodes, significantly lower LRR was observed in women treated with radiotherapy compared with women treated without radiotherapy. PMRT should be considered in the management of elderly women with these high-risk characteristics.

Fusing DEDD with ubiquitin changes its intracellular localization and apoptotic potential

DEDD, a highly conserved and ubiquitous death effector domain containing protein, exists in non, mono, and diubiquitinated forms. We previously reported that endogenous unmodified DEDD is only found in nucleoli and that mono- and diubiquitinated DEDD associate with caspase-3 in the cytosol suggesting that ubiquitination may be important to the apoptosis regulating functions of DEDD in the cytosol. We now demonstrate that many of its 16 lysine residues can serve as alternative acceptors for ubiquitination to maintain the monoubiquitination status of DEDD. A central region in DEDD (amino acids 109-305) outside the death effector domain was found to be essential for ubiquitination and/or the docking of the ubiquitination machinery. Fusion of ubiquitin to the C-terminus of DEDD to mimic monoubiquitinated DEDD relocated DEDD from nucleoli to the cytosol. This fusion protein also demonstrated a greater apoptosis potential than unmodified DEDD. Finally, we show that both mono- and polyubiquitination of DEDD can be achieved by the cellular inhibitor of apoptosis proteins 1 and 2 (cIAP-1/2). In addition, the cotransfection of DEDD with cIAP-1 or cIAP-2 results in the relocalization of the IAPs to the nucleoli. Our data suggest that monoubiquitination of DEDD regulates both its cytoplasmic localization and its proapoptotic potential and that IAP proteins can regulate DEDD's ubiquitination status.

Carcinoma erysipelatoides from squamous cell carcinoma of unknown origin

Carcinoma erysipelatoides, also known as inflammatory metastatic carcinoma, is a rare form of cutaneous metastasis from a malignancy. The characteristic histopathological finding is metastatic tumour cells inside the dermal lymphatic ducts. It is frequently observed in patients with breast carcinoma as well as adenocarcinoma of pancreas, rectum, lung, ovary and parotid gland. We present a 66-year-old man diagnosed to have metastatic squamous cell carcinoma by aspiration cytology from an enlarged neck lymph node and a core biopsy of a left axillary mass. He subsequently received radiotherapy; however, due to intolerance to erythema and swelling on local irradiated skin, radiotherapy was deferred. Skin lesions on upper chest and neck area, consisting of erythematous induration with telangiectasia and tenderness, progressed slowly and were treated as cellulitis. The erythema remained stationary with antibiotic treatment. Skin biopsy shows poorly differentiated squamous carcinoma cells within dermis and dilated dermal vessels.

Complex presentation of intussusception in childhood

The simultaneous occurrence of intussusception and volvulus in the paediatric age group is rare. We report the case of a volvulus of an ileoileal intussusception in an 8-year-old boy. This is the first time that computerised tomography (CT) images of a volvulus of an ileoileal intussusception have been published, and they clearly demonstrate both pathologies. This case highlights the use of CT in determining the nature of an abdominal mass and demonstrates how helpful it can be in diagnosing the cause of small bowel obstruction in children.

Adhesive capsulitis: sonographic changes in the rotator cuff interval with arthroscopic correlation

OBJECTIVE

To evaluate the sonographic findings of the rotator interval in patients with clinical evidence of adhesive capsulitis immediately prior to arthroscopy.

DESIGN AND PATIENTS

We prospectively compared 30 patients with clinically diagnosed adhesive capsulitis (20 females, 10 males, mean age 50 years) with a control population of 10 normal volunteers and 100 patients with a clinical suspicion of rotator cuff tears. Grey-scale and colour Doppler sonography of the rotator interval were used.

RESULTS

Twenty-six patients (87%) demonstrated hypoechoic echotexture and increased vascularity within the rotator interval, all of whom had had symptoms for less than 1 year. Three patients had hypoechoic echotexture but no increase in vascularity, and one patient had a normal sonographic appearance. All patients were shown to have fibrovascular inflammatory soft-tissue changes in the rotator interval at arthroscopy commensurate with adhesive capsulitis. None of the volunteers or the patients with a clinical diagnosis of rotator cuff tear showed such changes.

CONCLUSIONS

Sonography can provide an early accurate diagnosis of adhesive capsulitis by assessing the rotator interval for hypoechoic vascular soft tissue.

Livedoid vasculopathy: long-term follow-up results following hyperbaric oxygen therapy

BACKGROUND

Livedoid vasculopathy, also known as atrophie blanche, is a recurrent painful vasculopathy appearing mostly on the lower limbs. Treatment is challenging and relapses are frequent.

OBJECTIVES

To analyse the long-term effect and safety of hyperbaric oxygen (HBO) therapy in treating livedoid vasculopathy.

METHODS

Twelve patients with active livedoid vasculopathy were included in this study. All patients underwent HBO therapy five times a week. Each week photographs were taken and the total dose of analgesics was recorded. Side-effects were documented and assessed. Recurrence was defined as the presence of skin ulceration.

RESULTS

Of the eight patients who completed the treatment, resumption of ambulation and reduction of analgesics were achieved at an average of 4.9 HBO therapy sessions. Leg ulcers in all eight patients healed completely at a mean of 3.4 weeks (range 2-5 weeks). Six patients suffered relapses of ulceration and responded to additional HBO therapy. No significant side-effects were found.

CONCLUSIONS

HBO is a relatively safe, fast and effective method to treat patients with livedoid vasculopathy.

Longitudinal single-cell cytokine responses reveal recurrent autoimmune myelin reactivity in relapsing--remitting multiple sclerosis patients

The relationship between multiple sclerosis (MS) disease activity and myelin protein-induced cytokine responses over time is not elucidated. We addressed this relationship by examining longitudinal cytokine responses to myelin proteins every three months for one year, in the context of gadolinium (gad)-enhancing brain lesions and of clinical relapses. The ELISPOT assay was used to determine the ex vivo cytokine production in response to nine amino acid long peptides spanning the entire proteolipid protein (PLP) and myelin basic protein (MBP) molecules in relapsing-remitting (RR) MS patients and matched healthy controls. We identified three longitudinal levels of myelin-induced cytokine secretion by adding up the positive responses for all PLP or MBP peptides obtained for five timepoints, at three-month intervals: low reactivity (< 200 cumulative cytokine-secreting cells), isolated peptide reactivity (201-450 cumulative cytokine-secreting cells) and recurrent protein-wide bursts of cytokine reactivity (> 451 cumulative cytokine-secreting cells). The majority of MS patients showed recurrent bursts to PLP and MBP. In contrast, controls showed a more even distribution between all levels of cytokine reactivity. The majority of patients with gad-enhancing lesions showed PLP/IFN gamma and MBP/IFN gamma recurrent burst responses. This is the first longitudinal study on MS patients in which nine amino acid long myelin peptides are used to reveal the broad range of PLP- and MBP-peptide cytokine reactivity across the whole molecule of these two major myelin proteins. This study also reveals the extremely dynamic nature of the immune reactivity to numerous regions of myelin, which can fluctuate dramatically over time. Such fluctuation could hamper the efficacy of antigen-based therapies for MS.

Detection of oncogenic mutations in the EGFR gene in lung adenocarcinoma with differential sensitivity to EGFR tyrosine kinase inhibitors

The complete sequencing of the human genome and the development of molecularly targeted cancer therapy have promoted efforts to identify systematically the genetic alterations in human cancer. By high-throughput sequencing of tyrosine kinase genes in human non-small-cell lung cancer, we identified somatic mutations in the kinase domain of the epidermal growth factor receptor tyrosine kinase gene (EGFR) that are correlated with clinical response to EGFR tyrosine kinase inhibitors (TKIs). We have shown that these mutant forms of EGFR induce oncogenic transformation in different cellular systems. Cells whose growth depends on EGFR with mutations in exons 19 and 21 are sensitive to EGFR-TKIs, whereas cells expressing insertion mutations in exon 20 or the T790M point mutant, found in tumor biopsies from patients that relapsed after an initial response to EGFR-TKIs, are resistant. Furthermore, by applying a novel, massively parallel sequencing technology, we have shown that clinically relevant oncogene mutations can be detected in clinical specimens with very low tumor content, thereby enabling optimal patient selection for mutation-directed therapy. In summary, by applying high-throughput genomic resequencing, we have identified a novel therapeutic target, mutant EGFR, in lung cancer and evaluated its role in predicting response to targeted therapy.

Exogenous Bcl-xl fusion protein spares neurons after spinal cord injury

Spinal cord injury (SCI) induces neuronal death, including apoptosis, which is completed within 24 hr at and around the impact site. We identified early proapoptotic transcriptional changes, including upregulation of proapoptotic Bax and downregulation of antiapoptotic Bcl-xL, Bcl-2, and Bcl-w, using Affymetrix DNA microarrays. Because Bcl-xL is the most robustly expressed antiapoptotic Bcl-2 molecule in adult central nervous system, we decided to characterize better the effect of SCI on Bcl-xL expression. We found Bcl-xL expressed robustly throughout uninjured spinal cord in both neurons and glia cells. We also found Bcl-xL localized in different cellular compartments: cytoplasmic, mitochondrial, and nuclear. Bcl-xL protein levels decreased in the cytoplasm and mitochondria 2 hr after SCI and persisted for 24 hr. To test the contribution of proapoptotic decreases in Bcl-xL to neuronal death, we augmented endogenous Bcl-xL levels by administering Bcl-xL fusion protein (Bcl-xL FP) into injured spinal cords. Bcl-xL FP significantly increased neuronal survival, suggesting that SCI-induced changes in Bcl-xL contribute considerably to neuronal death. Because Bcl-xL FP increases survival of dorsal horn neurons and ventral horn motoneurons, it could become clinically relevant in preserving sensory and motor functions after SCI.

Histochemical study on neurodegeneration in the olfactory bulb after transient forebrain ischaemia in the Mongolian gerbil

In the present study, we investigated the ischaemia-related neurodegeneration in the main and accessory olfactory bulb (AOB) after 5 min transient forebrain ischaemia in the Mongolian gerbil using the acid fuchsin staining method. Between 5 and 15 days after ischaemia, acid fuchsin positive cells markedly increased in the external plexiform layer (EPL), mitral cell layer (ML) and glomerular layer (GL) of the main olfactory bulb (MOB), and in the mixed cell layer (MCL) and GL of the AOB. By 30 days after ischaemia reperfusion, acid fuchsin positive neurons were shrunken and showed low acidophilia in somata. Many necrotic vacuoles were found in the EPL and GL of the MOB 30 days after ischaemia. At this time, necrotic vacuoles were very few in the AOB. Therefore, our results suggest that the GL and EPL of the MOB are vulnerable to ischaemic damage at a later time after ischaemic insult, and that the AOB is more resistant to ischaemic damage as compared with the MOB.

Seeing the gene therapy: application of gene gun technique to transfect and decolour pigmented rat skin with human agouti signalling protein cDNA

We developed a gene gun method for the transfer of human agouti signalling protein (ASP) cDNA to alter rat skin colour in vivo. Human ASP cDNA was cloned into a modified cytomegalovirus plasmid and delivered to the skin of Long-Evans rats by gene gun bombardment. Skin pigmentation, body weight and blood sugar of ASP cDNA-transfected rats were recorded against the control group, which were injected with plasmids encoding for green fluorescent protein. The treated skin showed lighter skin colour after 3 days of ASP gene transfection. This depigmentation effect was most prominent on day 14 and the skin gradually returned to its original pigmentation by day 28. Successful transfection of ASP gene in skin and hair follicles, as well as downregulation of melanocortin-1 receptor (MC1R) and tyrosinase expression upon treatment, was confirmed using immunohistochemistry and Western blot analysis. Body weight and blood sugar in the treated rats did not show statistically significant differences as compared to control groups. These observations demonstrate that gene transfer using the gene gun method can induce high cutaneous ASP production and facilitate a switch from dark to fair colour without systemic pleiotropic effects. Such a colour switch may be that ASP is acting in a paracrine fashion. In addition, this study verifies that ASP exerts its functions by acting as an independent ligand that downregulates the melanocyte MC1R and tyrosinase protein in an in vivo system. Our result offers new, interesting insights about the effect of ASP on pigmentation, providing a novel approach to study the molecular mechanisms underlying skin melanogenesis.

Gene-specific expression and calcium activation of Arabidopsis thaliana phospholipase C isoforms

•  PI-PLCs synthesise the calcium releasing second messenger IP₃ . We investigated the expression patterns of the Arabidopsis PI-PLC gene family and measured in vitro activity of encoded enzymes. •  Gene specific RT-PCR and promoter-GUS fusions were used to analyse AtPLC gene expression patterns. The five available AtPLC cDNAs were expressed as fusion proteins in Escherichia coli. •  All members of the AtPLC gene family were expressed in multiple organs of the plant. AtPLC1, and AtPLC5 expression was localized to the vascular cells of roots and leaves with AtPLC5::GUS also detected in the guard cells. AtPLC4::GUS was detected in pollen and cells of the stigma surface. In seedlings, AtPLC2 and AtPLC3 were constitutively expressed, while AtPLCs 1, 4 and 5 were induced by abiotic stresses. AtPLC1-5 were all shown to have phospholipase C activity in the presence of calcium ions. •  AtPLCs showed limited tissue specific expression and expression of at least three genes was increased by abiotic stress. The differing calcium sensitivities of recombinant AtPLC protein activities may provide a mechanism for generating calcium signatures.

Age-related change of somatostatin-immunoreactive neurones in the main olfactory bulb of the rat

Somatostatin is found in the olfactory system, including the main olfactory bulb (MOB), and is thought to be one of the neuroactive substances for olfaction. However, somatostatin immunoreactivity in the olfactory system has not been determined during ageing. Hence, we examined the age-related changes of somatostatin-immunoreactive (IR) neurones in the rat MOB over a period of 2 years, at the following various ageing stages: post-natal month 1 (PM 1), PM 3, PM 6, PM 12 and PM 24. In PM 1 group, a few somatostatin-IR neurones were detected in the granule cell layer (GCL), and had slender or oval somata and short processes. At PM 3, somatostatin-IR neurones were observed in the glomerular, external plexiform and GCL. The size of somatostatin-IR somata was larger than that at PM 1. In PM 6 group, the number and size of somatostatin-IR neurones increased, and their processes became longer while running in various directions. At PM 12, somatostatin-IR neurones increased in number, and their processes became markedly longer than those at PM 6. At this stage, somatostatin-IR neurones had multipolar somata, and were the largest in size. In PM 24 group, somatostatin-IR neurones were most numerous. However, the processes of somatostatin-IR neurones were shorter than those at PM 12. This study suggests that the increased number of somatostatin-IR neurones in the MOB of aged rats may play a role to compensate for any decrease of olfactory function.

Evaluation of Serotypes of Staphylococcus aureus Strains Used in the Production of a Bovine Mastitis Bacterin

The five Staphylococcus aureus strains used in the manufacture of a commercially available bacterin were examined for capsular and surface polysaccharide serotypes. Double immunodiffusion assays of antigenic extracts of test and reference strains with monospecific typing sera to capsular serotypes 1, 2, 5, and 8 and to surface polysaccharide serotype 336 were performed to detect the specific reactivities and antigenic relationships of test samples. Antigenic extracts of two S. aureus strains reacted with antibodies to serotype 8, but not with antibodies to serotype 5, by producing specific precipitin lines. A third strain reacted with monospecific antibodies to serotype 5 and not with the antibodies to serotype 8. The extracts of two other strains failed to exhibit any detectable reaction with antiserum to serotypes 1, 2, 5, or 8. Antibodies to serotype 336, however, precipitated an identical, specific 336 antigen from the antigenic extracts of these two nontypeable strains. Thus, S. aureus bacterin includes one serotype 5, two serotype 8, and two serotype 336 strains, the three predominant serotypes responsible for bovine mastitis.

Improved production of teicoplanin using adsorbent resin in fermentations

AIMS

To use adsorbent resins in fermentations to eliminate toxic effects on growth, reduce feedback repression of production and assist in recovery of teicoplanin.

METHODS AND RESULTS

An adsorbent resin was added to the culture broth for the adsorption of teicoplanin. Amberlite XAD-16, Diaion HP-20, charcoal and silica gel were investigated as adsorbent resins. The adsorbed teicoplanin was extracted from the resin by 80% methanol after fermentation. Antibiotic activity was quantified by the disc-agar diffusion assay against Bacillus substilis, and qualitative evaluations were based on HPLC using YMC-Pack ODS-A column. Diaion HP-20 was the most effective adsorbent resin when added at a concentration of 5% (w/v) in the inoculation stage.

CONCLUSIONS

Addition of Diaion HP-20 in fermentations eliminated toxic effects on growth and reduced feedback repression of teicoplanin by adsorption. There was a 4.2-fold increase in the quantities of teicoplanin. Addition of adsorbent assisted in the recovery of teicoplanin by reducing the recovery steps.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study provide useful information for the production of teicoplanin, a glycopeptide antibiotic produced by Actinoplanes teicomyceticus. Addition of adsorbent in fermentation increased productivity of teicoplanin by more than five times.

Applications of the pulsatile flow versatile ECLS: in vivo studies

INTRODUCTION

T-PLS (Twin-Pulse Life Support) is the first commercial pulsatile ECLS (Extra Corporeal Life Support) device (1). The dual sac structure of T-PLS can effectively reduce high membrane oxygenator inlet pressure and hemolysis. To verify both the use of T-PLS for ECLS and the advantages of T-PLS, we tested various models.

METHOD AND RESULTS

In the partial CPB (cardio pulmonary bypass) model (swine), T-PLS (N = 6), and Biopump (N = 2), a single pulsatile pump (N = 2), were compared. In the case of single pulsatile flow, during pump systole, pressure increased to 700 - 800 mmHg at the inlet port of the membrane oxygenator. fHb, a hemolysis measurement value, was about 80 mg/dL at 3 hours. On the contrary, because of T-PLS's dual sac system, the pressure of T-PLS had a maximum value of about 250 mmHg and fHb was similar to that of the commercial centrifugal pumps. In the total CPB model (bovine, N = 6), the heart was stopped via cardioplegia (Kcl). T-PLS flow was maintained at 3.0-4.5 L/min. T-PLS functioned like a natural heart, having a pulse pressure of 26-43 mmHg and a pulse rate of 40-60 bpm (beats per minute). In the emergency case model (canine, N = 6), T-PLS was started 10 minutes after cardiac arrest from electronic shock. In spite of cardiac arrest for a period of 40 minutes, the heart was recovered after defibrillation. In the ARDS (Acute Respiratory Distress Syndrome) model (canine, N = 6), minimal ventilator parameters were set: tidal volume 130 ml, respiration rate = bpm, FiO2 = 10%. Three hours after starting T-PLS, PO2 of the carotid artery blood (after 2 hours: 195 +/- 89.4; after 3 hours: 258 +/- 99.3 mmHg) was above half the value of the femoral artery but was within normal range.

CONCLUSION

It is suggested that a portable pulsatile ECLS like T-PLS may be used as a CPB device and as an alternative CPR (cardiopulmonary resuscitation) device in the case of cardiac arrest. Due to the pulsatile flow, oxygenated blood is delivered to the patient without overloading the ARDS patients heart.

KCNQ1 mutations in patients with a family history of lethal cardiac arrhythmias and sudden death

Long QT syndrome (LQTS) is the prototype of the cardiac ion channelopathies which cause syncope and sudden death. LQT1, due to mutations of KCNQ1 (KVLQT1), is the most common form. This study describes the genotype-phenotype characteristics in 10 families with mutations of KCNQ1, including 5 novel mutations. One hundred and two families with a history of lethal cardiac events, 55 LQTS, 9 Brugada syndrome, 18 idiopathic ventricular fibrillation (IVF), and 20 acquired LQTS, were studied by single-strand conformational polymorphism (SSCP) and DNA sequence analyzes. Families found to have KCNQ1 mutations were phenotyped using ECG parameters and cardiac event history, and genotype-phenotype correlation was performed. No mutations were found in Brugada syndrome, IVF, or acquired LQTS families. Ten out of 55 LQTS families had KCNQ1 mutations and 62 carriers were identified. Mutations included G269S in domain S5; W305X, G314C, Y315C, and D317N in the pore region; A341E and Q357R in domain S6; and 1338insC, G568A and T587M mutations in the C-terminus. W305X, G314C, Q357R, 1338insC, and G568A, appeared to be novel mutations. Gene carriers were 26 +/- 19 years (32 females). Baseline QTc was 0.47 +/- 0.03 s (range 0.40-0.57 s) and 40% had normal to borderline QTc (< or = 0.46 s). Typical LQT1 T wave patterns were present in at least one affected member of each family, and in 73% of all affected members. A history of cardiac events was present in 19/62 (31%), 18 with syncope, 2 with aborted cardiac arrest (ACA) and six with sudden death (SD). Two out of 6 SDs (33%) occurred as the first symptom. No difference in phenotype was evident in pore vs. non-pore mutations. KCNQ1 mutations were limited to LQTS families. All five novel mutations produced a typical LQT1 phenotype. Findings emphasize (1) reduced penetrance of QTc and symptoms, resulting in diagnostic challenges, (2) the problem of sudden death as the first symptom (33% of those who died), and (3) genetic testing is important for identification of gene carriers with reduced penetrance, in order to provide treatment and to prevent lethal cardiac arrhythmias and sudden death.

Antibiotic selective pressure for the maintenance of antibiotic resistant genes in coliform bacteria isolated from the aquatic environment

Coliform bacteria isolated from the aquatic environment were investigated for antibiotic susceptibility and detailed structures of class 1 integrons. A high proportion of isolates were found to be resistant to sulfamethoxazole, aminoglycosides, and beta-lactams. The 750 (53.6%) isolates were resistant to one or more of the antibiotics tested out of 1,400 coliform bacteria. Based on the MIC of antibiotics and antibiogram, 150 isolates were selected and further studied for class 1 integrons. The intI1 gene was found in 36 (24.0%) of the 150 isolates. Twelve isolates carried the gene cassettes responsible for antibiotic resistance, while no gene cassettes were found in 24 isolates. Seven different genes, dfrA5, dfrA7, dfrA12, dfrA17, aaA2, aaA5, and aad(3'), were detected in gene cassettes. The dfrA and aad genes located on class 1 integrons were responsible for resistance to trimethoprim and aminoglycosides. The remaining 24 coliform bacteria had the incomplete or non-functional class 1 integrons. These results indicated that antibiotic selective pressures may play an important role to maintain gene cassettes of class 1 integrons and in the absence of sustained antibiotic pressures, such as the aquatic environment, coliform bacteria may carry empty or non-functional class 1 integrons.

Ramosetron for the prevention of cisplatin-induced acute emesis: a prospective randomized comparison with granisetron

Control of nausea and vomiting is very important in determining patient compliance with cisplatin chemotherapy. A multicentre, randomized, single-blind study was conducted to compare the tolerability and efficacy of ramosetron with those of granisetron over 24 h following cisplatin administration to cancer patients. In eight study centres, a total of 194 adult patients were randomly assigned to receive either intravenous ramosetron 0.3 mg or intravenous granisetron 3.0 mg. The anti-emetic effect of ramosetron determined from the no-vomiting rate lasted longer, but there was no significant difference in the number of acute vomiting episodes or the severity of nausea between the two groups. In the tolerability evaluation, there were no statistically significant differences between the two groups, except for a higher incidence of dull headache in the granisetron group. Ramosetron and granisetron appear to have equivalent efficacy and tolerability profiles, but the effects of ramosetron on the prevention of acute vomiting in patients undergoing cisplatin chemotherapy were longer lasting.

Investigation of the prognostic value of coexpressed erbB family members for the survival of colorectal cancer patients after curative surgery

Epidermal growth factor receptor (EGFR), erbB2, erbB3 and erbB4 are four transmembrane glycoproteins belonging to the subtype I tyrosine kinases. They share structure homologies and are believed to direct cellular growth through the ligand-stimulated tyrosine phosphorylation of intracellular substrate. The overexpression of these tyrosine kinases has been linked to various cancers. To examine the role of the erbB family in the neoplastic transformation of the human colon, we analysed the protein expression of these four members by immunohistochemistry in paraffin-embedded specimens from 125 resected colorectal cancers. Our data showed that for EGFR expression, 62 (50%) were scored as '+', and 2 (2%) as '++'. For erbB2 expression, 39 (31%) were classified as '+', and 5 (4%) as '++'. For erbB3 expression, 43 (34%) were scored as '+', and 3 (2%) as '++'. A significantly higher percentage of overexpressed erbB3 was observed in early stage carcinomas (Dukes' stage A or B) (50%) than in advanced stage cancers (Dukes' stage C or D) (15%) (P<0.0001). For erbB4 expression, 22 (18%) were scored as '+', and 5 (4%) as '++'. Early stage patients had a lower percentage of erbB4 overexpression than the late stage ones (18% versus 28%). Concomitant overexpression of erbB2 and erbB3 occurred in 21% (16/78) of the early stage carcinomas, whereas it occurred in only 2% (1/47) of the late stage ones (P=0.003). Conversely, simultaneous overexpression of erbB2 and erbB4 occurred in 17% (8/47) of the late stage carcinomas but in only 4% (3/78) of the early stage ones (P=0.02). Overexpression of EGFR, erbB2, erbB3 or erbB4 alone was not significantly associated with a shortened survival. However, patients with a simultaneous overexpression of erbB2 and erbB4 had a shorter overall survival time than others in the univariate analysis (P=0.01). This significance disappeared after adjustment for Dukes' staging in the Cox model. In conclusion, overexpressed erbB3 was common in early stage colorectal cancers, but its prevalence was significantly reduced in late stage ones. The percentage of its coexpression with erbB2 was significantly higher in early stage than in late-stage cancers. Heterodimerisation between erbB2 and erbB4 may play a role in the late stages of carcinogenesis.

p21(WAF1) is associated with CDK2 and CDK4 protein during HL-60 cell differentiation by TPA treatment

TPA-treated HL-60 cells are mainly arrested in G1 by p21(WAF1) accumulation. We investigate the downstream changes following such accumulation. Increased p21(WAF1) is associated with CDK2 and CDK4. pRb is dephosphorylated in the presence of p21-CDK2/4 complexes, and the Rb-E2F1 complex increases after TPA treatment, whereas the Rb-HDAC1 complex decreases slightly. Our results suggest that increased p21(WAF1) is associated with CDK2/4, and that these complexes induce pRb dephosphorylation. In turn, hypophosphorylated pRb are mainly complexed with E2F1, but HDAC1 appears not to be a key component in this process.

Deformation-enhanced fluctuations in the red cell skeleton with theoretical relations to elasticity, connectivity, and spectrin unfolding

To assess local elasticity in the red cell's spectrin-actin network, nano-particles were tethered to actin nodes and their constrained thermal motions were tracked. Cells were both immobilized and controllably deformed by aspiration into a micropipette. Since the network is well-appreciated as soft, thermal fluctuations even in an unstressed portion of network were expected to be many tens of nanometers based on simple equipartition ideas. Real-time particle tracking indeed reveals such root-mean-squared motions for 40-nm fluorescent beads either tethered to actin directly within a cell ghost or connected to actin from outside a cell via glycophorin. Moreover, the elastically constrained displacements are significant on the scale of the network's internodal distance of approximately 60-80 nm. Surprisingly, along the aspirated projection-where the network is axially extended by as much as twofold or more-fluctuations in the axial direction are increased by almost twofold relative to motions in the unstressed network. The molecular basis for such strain softening is discussed broadly in terms of force-driven transitions. Specific considerations are given to 1) protein dissociations that reduce network connectivity, and 2) unfolding kinetics of a localized few of the red cell's approximately 10(7) spectrin repeats.

Pyrimidinylimidazole inhibitors of p38: cyclic N-1 imidazole substituents enhance p38 kinase inhibition and oral activity

Optimization of a series of N-1-cycloalkyl-4-aryl-5-(pyrimidin-4-yl)imidazole inhibitors of p38 kinase is reported. Oral administration of inhibitors possessing a cyclohexan-4-ol or piperidin-4-yl group at N-1 in combination with alkoxy, amino(alkyl), phenoxy and anilino substitution at the 2-position of the pyrimidine was found to potently inhibit LPS-induced TNF in mice and rats. The selectivity of these new inhibitors for p38 kinase versus eight other protein kinases is high and in all cases exceeds that of SB 203580.

Anti-tumor effect associated with down-regulation of MHC class 1 antigen after co-transfection of GM-CSF and IFN-gamma genes in CT26 tumor cells

We previously reported that co-expression of GM-CSF and IFN-gamma genes in tumors induces a synergistic anti-tumor effect. Interestingly, we have used flow cytometry to identify two kinds of populations of CT26 cells that co-express GM-CSF and IFN-gamma genes: one population (CT26/G/I-down) that expresses very low levels of MHC class I and a second population (CT26/G/I-up) that expresses high levels of H-2Kd antigen. We have compared the anti-tumor effect between CT26/I-up and CT26/G/I-down cells. When wild-type (wt) CT26 cells were injected subcutaneously into Balb/c mice, tumor was formed 5-7 days after injection. However, when both CT26/G/I-up and CT26/G/I-down cells were injected, we did not identify any tumor. The protection' study showed that both CT26/G/I-up and CT26/G/I-down. cells could induce systemic immunity against secondary challenge with unmodified parental tumor cell. CT26/G/I-down cells showed normal expression of the heavy chain of MHC class I (HC), beta2-microglobulin (beta2m) and the TAP gene. Furthermore, in CT26/G/I-down cell, although the MHC molecules were detected normally in the cytoplasmic fraction, no message was detected in the membrane fraction. Pulse-chase experiments showed that class I antigen was normally synthesized like wt CT26 or CT26/G/I-up cells. Based on our results, non-MHC restricted immune effectors might play the major role in synergistic anti-tumor effects with co-expression of GM-CSF and IFN-gamma in CT26 tumor model.

Capsule production and growth phase influence binding of complement to Staphylococcus aureus

Complement-mediated opsonization of bacteria by C3 binding is an important component of the host innate immune system. Little information is available concerning the interaction between complement proteins and capsule type 5 and 8 Staphylococcus aureus strains, even though these isolates are responsible for approximately 70% of human staphylococcal infections. To investigate the importance of an intact complement pathway in an experimental staphylococcal infection, control and C3-depleted mice were challenged intravenously with 10(7) CFU of a serotype 5 S. aureus isolate. Whereas only 8% of the control mice succumbed to the infection, 64% of the complemented-depleted animals died. In vitro parameters of C3 binding to two heavily encapsulated (CP++) strains, three encapsulated (CP+) strains, and an isogenic capsule-negative (CP-) mutant were examined. The alternative pathway contributed 90% of C3 binding in 20% serum at 30 min, whereas it accounted for only 13% of C3 binding in 2% serum. Stationary-phase organisms bound only 10% as much C3 as mid-log-phase organisms; this was only in part due to capsule. When the S. aureus strains were cultivated on solid medium, the CP++ isolates bound 50% less C3 than CP+ strains; a CP+ strain bound 42% less C3 than the CP- mutant. Both C3b and iC3b fragments of C3 bound to S. aureus cells, and about one-third of the bound C3 was shed from the staphylococcal surface as iC3b, regardless of the CP phenotype of the strain. Thus, the phase of growth and presence of capsule are critical to opsonization.

Differential cardiovascular effects of pharmacological agents in chickens selected for high and low body weight

This study was conducted to investigate whether there are differences in the autonomic nervous system function of chickens from lines selected for high (HWS) or low body weight (LWS). The cardiovascular response to various pharmacological agents was used as an indicator of autonomic nervous system response. Ten individuals from each line and sex were used in the study. Catheters were introduced into the left brachial artery and vein and connected to a MP100-BIOPAC system to record blood pressure and heart rate (HR). Chickens were injected with phenylephrine, atropine, propranolol, and tetraethylammonium chloride (TEAC). The LWS birds exhibited a greater increase in mean arterial blood pressure (MABP) and a lesser increase in HR than the HWS birds following atropine. The response to atropine showed a line and sex interaction in which male birds had a greater increase in HR than females and LWS females had a lower increase in HR than the HWS females. Injection of phenylephrine following pretreatment with atropine caused a baroreceptor reflex in which males showed a greater decrease in HR than females. In response to the beta-adrenergic receptor blocker propranolol, females displayed a greater decrease in MABP than males and LWS birds had a greater decrease in HR than HWS birds. In response to the autonomic ganglionic blocker TEAC, MABP and HR decreased equally in both lines. The percentage of adrenal and sympathetic impact on regulation of HR showed that LWS females required greater adrenal activity than those from the other subclasses. Although changes in HR and MABP ratios in response to phenylephrine were different between lines, these responses were not different when phenylephrine was given following atropine. This pattern of response suggested that HWS birds had greater parasympathetic nervous system activity in order to maintain cardiovascular function. These results demonstrate that selection for HWS or LWS has resulted in greater parasympathetic and sympathetic nervous system tone in birds from the HWS and LWS birds, respectively, and suggest that differences between the lines could be at the level of the chromaffin tissue in the adrenal gland.

BAPTA/AM, an intracellular calcium chelator, induces delayed necrosis by lipoxygenase-mediated free radicals in mouse cortical cultures

1. Disruption of calcium homeostasis during neurodegenerative diseases is known to trigger apoptotic or necrotic death in neuronal cells. Recently, the authors reported that intracellular calcium restriction by NMDA receptor antagonists induces apoptosis in cortical cultures. To evaluate whether further restriction of intracellular free calcium can induce apoptosis or necrosis, we examined the neurotoxic characterization of BAPTA/AM, a permeable free calcium chelator, in mouse cortical cultures. 2. Exposure of mixed (glia and neuron) cortical cultures (DIV 13-16) to 3-10 microM BAPTA/AM (non-toxic concentration for glial cells) for 24-48 hr resulted in delayed and necrotic neuronal death. The necrotic findings included swelling and loss of mitochondria and endoplasmic reticulum (ER) with neuronal membrane rupture 24 hr after treatment with BAPTA/AM. Simultaneously, we observed a few TUNEL-positive cells in the neuronal subpopulation of the same cultures. 3. The neurotoxicity evoked by BAPTA/AM (10 microM) was significantly attenuated by the addition of 0.5 microM cycloheximide (a protein synthesis inhibitor), 10 microM actinomycin D (an RNA transcription inhibitor), a high extracellular potassium concentration (total 15 mM KCl), 100 microM t-ACPD (a metabotrophic agonist), 100 microM alpha-tocopherol (a free radical scavenger), 100 microM deferoxamine (a ferric ion chelator), 100 microM L-NAME (a nitric oxide synthase (NOS) inhibitor), 50 microM DNQX (a non-NMDA receptor blocker), and 3-30 microM esculetin (a lipoxygenase inhibitor). However, 0.3-3 mM ASA (a cyclooxygenase inhibitor), 100 ng/ml nerve growth factor (NGF), 10 microM MK-801 (a NMDA receptor antagonist), 20 microM zVAD-fmk (caspase inhibitor) and 50 U/ml catalase failed to inhibit the injury. 4. However, NGF and catalase blocked the neurotoxicity induced by BAPTA/AM in young neuronal cells (DIV 6). BAPTA/AM (10 microM) did not alter the expression of inducible nitric oxide synthase (iNOS) on glial cells. 5. These results suggest that the feature of neuronal death induced by BAPTA/AM exhibits predominantly delayed necrosis mediated by lipoxygenase-dependent free radicals.

Additive effects of a sodium chloride restricted diet and furosemide administration in healthy dogs

OBJECTIVE

To determine the effects of a low or high sodium (Na) diet with or without furosemide administration on plasma electrolyte concentrations and the renin-angiotensin-aldosterone system in healthy dogs.

ANIMALS

20 healthy adult dogs.

PROCEDURE

Dogs were randomly allotted to 4 groups of 5 dogs each as follows: dogs fed a low Na diet (0.08% Na and 0.8% chloride [CI] on a dry matter [DM] basis); dogs fed a low Na diet with added NaCl (1.0% Na and 2.2% Cl on a DM basis); dogs fed a low Na diet and treated with furosemide (2 mg/kg of body weight, PO, q 12 h); and dogs fed a low Na diet with added NaCl and treated with furosemide. Plasma electrolyte concentrations were measured on days 0, 21, and 35. Plasma renin activity and aldosterone concentration were analyzed by use of radioimmunoassays on days 0, 21, 35, and 53.

RESULTS

Furosemide treatment significantly decreased plasma Cl concentration and significantly increased plasma renin activity and aldosterone concentration. Dogs fed a low Na diet had significantly higher plasma renin activities and plasma aldosterone concentrations. A significant interaction between a low Na diet and furosemide administration resulted in the lowest plasma Cl concentrations, highest plasma renin activities, and highest plasma aldosterone concentrations.

CONCLUSIONS AND CLINICAL RELEVANCE

In healthy dogs, feeding a low Na diet and administering furosemide resulted in an additive effect on plasma Cl concentration, renin activity, and aldosterone concentration, which may be an important consideration for treating dogs with cardiac disease.

Cytochrome b gene for species identification of the conservation animals

A partial DNA sequence of cytochrome b gene was used to identify the remains of endangered animals and species endemic to Taiwan. The conservation of animals species included in this study were: the formosan gem-faced civets, leopard cats, tigers, clouded leopards, lion, formosan muntjacs, formosan sika deers, formosan sambars, formosan serows, water buffalo, formosan pangolins and formosan macaques. The control species used included domestic cats, domestic dogs, domestic sheeps, domestic cattles, domestic pigs and humans. Heteroplasmy was detected in the formosan macaque, domestic pig and domestic cats. The frequencies of heteroplasmy in these animals were about 0.25% (1 in 402bp). Sequences were aligned by Pileup program of GCG computer package, and the phylogenetic tree was constructed by the neighbor-joining method. The results of sequence comparison showed that the percentage range of sequence diversity in the same species was from 0.25 to 2.74%, and that between the different species was from 5.97 to 34.83%. The results of phylogenetic analysis showed that the genetic distance between the different species was from 6.33 to 40.59. Animals of the same species, both the endangered animal species and domestic animals, were clustered together in the neighbor-joining tree. Three unknown samples of animal remains were identified by this system. The partial sequence of cytochrome b gene adopted in this study proved to be usable for animal identification.

Identification and initial characterization of 5000 expressed sequenced tags (ESTs) each from adult human normal and osteoarthritic cartilage cDNA libraries

OBJECTIVE

To prepare, sequence and analyse adult human cartilage cDNA libraries to study the gene expression pattern between normal and osteoarthritic cartilage.

METHODS

Poly A(+)RNA from adult human normal and osteoarthritic articular cartilage was isolated and used to prepare cDNA libraries. Approximately 5000 ESTs from each library were sequenced and analysed using bioinformatic tools. The expression of select genes was confirmed by Northern blot and in situ hybridization analysis.

RESULTS

Multiple gene families including several classical cartilage matrix protein encoding genes were identified. Approximately 28-40% of the genes sequenced from these libraries were novel, while half of the genes encoded known proteins and 4-6% of the genes encoded novel homologs of known proteins. Several known genes, whose expression has not been reported previously in cartilage, were also identified. We have confirmed the cartilage expression of three known (CTGF, CTGF-L and clusterin) and two novel homologs of known genes (PCPE-2 and Gal-Nac transferase) by Northern blot and in situ hybridization analysis.

CONCLUSION

This is the first report of the preparation and sequencing of cDNA libraries from adult human normal and osteoarthritic articular cartilage. Further analysis of genes identified from these libraries may provide molecular targets for diagnosis and/or treatment of osteoarthritis (OA).

Resurfacing of the nasopharynx after nasopharyngectomy using a free radial forearm flap

BACKGROUND

Nasopharyngectomy is emerging as an important treatment option for salvaging locally recurrent nasopharyngeal carcinoma (NPC). After nasopharyngectomy, resurfacing the nasopharynx and covering the internal carotid artery is important to minimize the risk of infection, osteoradionecrosis, and carotid rupture. Previous authors have advocated the use of free grafts of skin and mucosa for this purpose but have also described significant rates of partial and total graft failure.

METHODS

We believe that the best and most reliable way to resurface the nasopharynx is with vascularized tissue, and our preference is for the use of a free radial forearm flap. To illustrate our approach, we present two patients who underwent nasopharyngectomy by means of a maxillary swing approach and who had resurfacing of the surgical defect with a free radial forearm flap.

RESULTS

Both patients had complete en bloc resection of tumor followed by the insetting of a free radial forearm flap to reline the surgical defect. Both flaps remained completely viable, and both patients achieved successful resurfacing of the entire nasopharynx. The morbidity of surgery was minimal, and there were no perioperative complications. On assessment 1 year later, the free radial forearm flap continues to reline the entire neonasopharynx, and the long-term functional recovery after surgery is excellent.

CONCLUSION

Resurfacing the nasopharynx after nasopharyngectomy with a free radial forearm flap aids healing and minimizes the risk of complications. The morbidity of surgery is minimal and the functional recovery is excellent.

Apoptotic cell death induced by Acinetobacter baumannii in epithelial cells through caspase-3 activation

Epithelial cell death induced by Acinetobacter baumannii infection was investigated using in vitro assays. Eight hours after live A. baumannii infection, HeLa cells exhibited detachment from the dish, rounding morphologies, high proportions of trypan blue-positive cells and extensive DNA breakdown with faint apoptotic banding, which is indicative of cells undergoing apoptosis. The enzymatic activity of caspase-3 was increased in cells as early as 2 h after infection. In addition, apoptosis of HeLa cells was induced by treatment with bacterial culture filtrates but not with formalin-killed bacteria. These results indicate that A. baumannii infection triggers apoptosis in HeLa cells through caspase-3 activation.

Structural and functional linkages between subunit interfaces in mammalian pyruvate kinase

Mammalian pyruvate kinase (PK) is a four-domain enzyme that is active as a homo-tetramer. Tissue-specific isozymes of PK exhibit distinct levels of allosteric regulation. PK expressed in muscle tissue (M1-PK) shows hyperbolic steady-state kinetics, whereas PK expressed in kidney tissue (M2-PK) displays sigmoidal kinetics. Rabbit M1 and M2-PK are isozymes whose sequences differ in only 22 out of 530 residues per subunit, and these changes are localized in an inter-subunit interface. Previous studies have shown that a single amino acid mutation to M1-PK at either the Y (S402P) or Z (T340 M) subunit interface can confer a level of allosteric regulation that is intermediate to M1-PK and M2-PK. In an effort to elucidate the roles of the inter-subunit interaction in signal transmission and the functional/structural connectivity between these interfaces, the S402P mutant of M1-PK was crystallized and its structure resolved to 2.8 A. Although the overall S402P M1-PK structure is nearly identical with the wild-type structure within experimental error, significant differences in the conformation of the backbone are found at the site of mutation along the Y interface. In addition, there is a significant change along the Z interface, namely, a loss of an inter-subunit salt-bridge between Asp177 of domain B and Arg341 of domain A of the opposing subunit. Concurrent with the loss of the salt-bridge is an increase in the degree of rotational flexibility of domain B that constitutes the active site. Comparison of previous PK structures shows a correlation between an increase in this domain movement with the loss of the Asp177: Arg341 salt-bridge. These results identify the structural linkages between the Y and Z interfaces in regulating the interconversion of conformational states of rabbit M1-PK.