Human osteoarthritic chondrocytes are impaired in matrix metalloproteinase-13 inhibition by IFN-gamma due to reduced IFN-gamma receptor levels

OBJECTIVE

Human osteoarthritic (OA) cartilage type-II collagen is preferentially cleaved by the proinflammatory cytokine-induced matrix metalloproteinases-13 (MMP-13). Interferon-gamma (IFN-gamma) potently inhibits interleukin-1 (IL-1)-induced MMP-13 expression in healthy chondrocytes. Our goal was to study the previously unknown impact of IFN-gamma on MMP-13 in OA and compare the levels and functional activity of IFN-gamma receptor (IFN-gammaR1) in healthy and OA chondrocytes.

METHODS

Chondrocytes were obtained from OA patients and non-arthritic control subjects and treated with IL-1+ or- IFN-gamma. MMP-13 mRNA and protein expression were measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. IFN-gammaR1 expression was assessed by flow cytometry, immunoprecipitation and immunohistochemistry with fluorescein-labeled antibody. IFN-gammaR1 was neutralized with its antibody and signal transducer and activator of transcription 1 (STAT1) phosphorylation analyzed by Western blotting. OA chondrocytes were also transfected with control and IFN-gammaR1 expression vectors.

RESULTS

OA chondrocytes displayed a drastically impaired MMP-13 suppression by IFN-gamma compared to control cells. IFN-gammaR1 levels were significantly decreased in OA chondrocytes as assessed by flow cytometry, immunoprecipitation and immunohistochemistry. Consequently, IFN-gamma-stimulated STAT1 phosphorylation mediated by IFN-gammaR1 was also considerably reduced in OA patient chondrocytes. IFN-gammaR1 overexpression in OA cells restored MMP-13 suppression by IFN-gamma.

CONCLUSIONS

Ability of IFN-gamma to suppress IL-1-induced MMP-13 expression is diminished in OA chondrocytes due to decreased IFN-gammaR1 levels, activity and impaired downstream signal transduction. Therefore, IFN-gammaR1 modulation and weakened endogenous IFN-gamma response may be important mechanisms in OA pathogenesis and cartilage degradation.

A study of microbial colonisation of orthopaedic tourniquets

INTRODUCTION

Tourniquets are employed widely in orthopaedic surgery. The use of the same tourniquet on a repetitive basis without a standard protocol for cleaning may be a source of cross-infection. This study examines the contamination of the tourniquets in our institution.

MATERIALS AND METHODS

Agar plates were used to take samples from 20 tourniquets employed in orthopaedic procedures. Four sites on each tourniquet were cultured and incubated at 37 degrees C for 48 h.

RESULTS

All sampled tourniquets were contaminated with colony counts varying from 9 to > 385. Coagulase-negative Staphylococcus spp. were the most commonly grown organisms from the tourniquets (96%). Some tourniquets had growths of important pathogens including methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas spp., and S. aureus. On cleaning five tourniquets with Clinell (detergent and disinfectant) wipes (GAMA Healthcare Ltd, London, UK), there was a 99.2% reduction in contamination of the tourniquets 5 min after cleaning.

CONCLUSIONS

In addition to the manufacturers' guidelines, we recommend the cleaning of tourniquets with a disinfectant wipe before every case.

Photoperiod-testicular-immune interaction in a seasonal breeder Indian palm squirrel Funambulus pennanti during the reproductively inactive and active phases

The differential effect of long (LD; 16 : 8 h light/dark), short (SD; 10 : 14 h light/dark) and natural day length (NDL; 12 : 12 h light/dark) during the reproductively inactive (RIP) and active (RAP) phases was assessed in relation to immunity and reproductive function of a tropical rodent Funambulus pennanti. They presented high immunity and low testicular activity during RIP and an opposite during RAP. SD increased spleen and thymus weight, leukocyte and lymphocyte counts, cell mediated immunity [i.e. blastogenic response in terms of percentage stimulation ratio of splenocytes and thymocytes (when challenged with concanavalin A)] and delayed type hypersensitivity to oxazolone. SD during RIP increased the above mentioned parameters and reduced testes weight compared to NDL groups. During RAP, LD reduced all the immunological parameters when compared with NDL and SD experiencing groups of RIP and RAP phases. The LD group reduced the immunological parameters compared to RAP, suggesting that LD had always an inhibitory effect on immune status being independent of reproductive phases. The intensity of the stimulatory effects of SD and inhibitory effects of LD during both reproductive phases was significantly different. We exposed another set of squirrels to the above photoperiodic schedule for prolonged period (30 weeks) during RAP. A clear testicular refractoriness followed by immunorefractoriness was observed in the group experiencing SD and LD for 30 weeks. The photorefractoriness presented by the testes was inversely related to the immunorefractoriness. The peripheral melatonin level of those squirrels reflected the photoperiodic signal perceived by squirrels for immunomodulation and gonadal function, suggesting that immune system and gonadal function might have coevolved.

Head injury with temporal bone fracture: one year review of case incidence, causes, clinical features and outcome

To investigate the case incidence, causes, clinical profile and outcome of temporal bone fracture complicating head trauma. A 1-year (2005) retrospective study of head injured patients presented to the Emergency Department, Hospital Tengku Ampuan Afzan, Kuantan, Pahang, Malaysia. Gender distribution, cause of injury, radiological findings and otorhinolaryngological clinical presentations were analyzed. Of 1309 patients, 61 patients were diagnosed to have temporal bone fracture (4.7%). Majority of cases were caused by motor vehicle accident (85.9%) and were predominantly male (88.5%). The right temporal bone was more frequently fractured (62.3%). Most (88.5%) were petro-mastoid fractures. Sixty-seven percent of the petrous fractures were longitudinal type. Clinical presentations mostly reported were blood rhinorrhea (36%) and blood otorrhea (32.7%). Other clinical presentations were hearing loss (9.8%), cranial nerve palsy (8.2%), cerebrospinal fluid oto-rhinorrhea (8.2%) and labyrinth concussion (6.5%). Four out of five cranial nerve palsies were facial nerve. Out of the 61 cases, 16 (26.2%) had no clinical presentation at the time of Emergency Department consultation. Thirteen (21.3%) died due to severe head injury. The case incidence of temporal bone fracture in head injured patients in our centre is 4.7%. The petro-mastoid type fracture predominates. Proper early diagnosis and management minimize complications.

Modulation of striatal dopamine release by 5-HT2A and 5-HT2C receptor antagonists: [11C]raclopride PET studies in the rat

RATIONALE

Antagonism at serotonin 5-HT2A and 5-HT2C receptors modulates cortical and striatal dopamine (DA) release and may underlie some aspects of the clinical efficacy of 'atypical' antipsychotic compounds. However, it is not known whether 5-HT2A/2C receptor-mediated modulation of DA release can be quantified with non-invasive neurochemical imaging, as would be required for investigation of these processes in man.

OBJECTIVE

The objective of the study was to perform a feasibility study in the rat in order to determine whether 5-HT2A/2C modulation of DA release can be observed using positron emission tomography (PET) imaging.

MATERIALS AND METHODS

Rats were administered with either vehicle, a combined 5-HT2A/2C antagonist (ketanserin, 3 mg/kg i.p.), or the more selective 5-HT2C antagonist SB 206,553 (10 mg/kg i.p.) 30 min before administration of the PET DA D2 receptor radiotracer [11C]raclopride ( approximately 11 MBq) and were then scanned for 60 min using a quad-high-density avalanche chamber small animal tomograph. Using the same technique, modulation of amphetamine (4 mg/kg)-induced decreases in [11C]raclopride binding by 5-HT2A antagonism (SR 46349B, 0.2 mg/kg i.v.) was also determined.

RESULTS

Consistent with the increase in DA release measured by others using microdialysis, 5-HT2C antagonism markedly reduced striatal [11C]raclopride binding (p < 0.003), while amphetamine-induced reductions in striatal [11C]raclopride binding (p < 0.001) were attenuated by 5-HT2A antagonist administration (p = 0.04).

CONCLUSIONS

These results inform the feasibility of monitoring 5-HT2A/2C receptor-mediated modulation of DA systems in man using PET and, more generally, demonstrate that D2 radiotracer PET imaging may be used to monitor the efficacy of new DA modulators in attenuating stimulated DA release.

Synthesis of α-Mannosylated Phenolics as α-Glucosidase Inhibitors*

BF3OEt2-catalysed glycosidation of phenolic compounds 3 and 6 with the mannofuranosyl glycosyl donor 2 separately gave the corresponding alpha-mannofuranosyl derivatives 4 and 7 in good yield, and the latter on selective deacetonation (hydrolysis) with 2% aqueous HCl afforded 5 and 8 respectively. Compounds 4 and 7 inhibited rat intestinal alpha-glucosidase more effectively than a standard drug acarbose.

Sea urchin spine injuries of the hand

Sea urchin spine injuries are common. They usually cause local pain and swelling that subsides. Chronic granulation is rare. We report two cases of sea urchin granulomata involving finger metacarpophalangeal joints. Both resolved following surgery.

Posterior mediastinal abscess secondary to esophageal perforation following fish bone ingestion

Accidental swallowing of fish bone, which arrested in esophagus, is fairly common. However the incidence of esophageal perforation due to fish bone swallowing is low. Delayed posterior mediastinal abscess as a result of the esophageal perforation is a rare manifestation and may lead to fatal outcome. Two cases of delayed formation of posterior mediastinal abscess following esophageal perforation due to accidental fish bone ingestion are described here. In these cases patients presented with interscapular back pain. In one of the cases the patient died because of the presentation was misdiagnosed hence leading to delay in the intervention. Radiological findings and surgical management namely esophagoscopy and neck exploration are briefly described.

The use of an In House Scoring System Scale versus Glasgow Coma Scale in non-traumatic altered states of consciousness patients: can it be used for triaging patients in Southeast Asian developing countries?

Non-traumatic Altered States of Consciousness (ASC) are a non-specific consequence of various etiologies, and are normally monitored by Glasgow Coma Scale (GCS). The GCS gives varriable results among untrained emergency medicine personel in developing countries where English is not the first language. An In House Scoring System (IHSS) scale was made by the first author for the purpose of triaging so as to quickly asses patients when seen by medical personel. This IHSS scale was compared to the GCS to determine it's specificity and sensitivity in the accident and emergency department (ED) of Hospital University Sains Malaysia (HUSM). All patients with non-traumatic ASC were selected by purposive sampling according to pre-determined criteria. Patients were evaluated by the two systems, IHSS and GCS, by emergency physicians who were on call. Patient demographics, clinical features, investigations, treatment given and outcomes were collected and followed for a period of 14 days. A total of 221 patients with non-traumatic ASC were studied, 54.3% were males. The mean age of the patients was 56 years old. The mean overall GCS score on presentation to the ED was 10.3. The mean duration of ASC was 11.6 hours. One hundred thirty patients (58.8%) experienced ASC secondary to general or focal cerebral disorders. The mortality rate was 40.3% 2 weeks after the ED visit. Fifty-four point three percent of the patients were awake and considered to have good outcomes while 45.7% of the patients had poor outcomes (comatose or dead) 2 weeks after the ED visit. The mean overall GCS score, verbal and motor subscores as well as the IHSS had significantly decreased (worsened) after treatment in the ED. A poor IHSS scale, hypertension, current smoking, abnormal pupillary reflexes and acidosis were associated with a worse 2-week outcome. The mean age and WBC count was lower and the mean overall GCS score and eye, verbal and motor subscores were higher as well as those having a lower IHSS scale for the good outcome category. Multivariate analysis revealed that smokers and hypertensives were at higher risk for a poor outcome. Higher eye scores on the GCS were associated fewer poor outcomes. There was significant agreement between the IHSS scale and GCS scores in the assessment of non-traumatic ASC. The sensitivity and specificity of the IHSS score versus GCS were 71.9% and 100.0%, respectively.