A pre-admission triaging tool to predict severe COVID-19 cases: ABCD score

INTRODUCTION

Isolation of SARS-CoV-2-infected individuals is an important COVID-19 pandemic control measure. While most cases have uncomplicated infection, a small proportion of them has developed life-threatening disease. We set up a retrospective study to determine preadmission triaging tool to predict the development of severe COVID-19.

MATERIALS AND METHODS

A retrospective study was conducted from 1 October 2020 to 31 January 2021 with enrolment of all SARS-CoV-2 PCR-confirmed persons aged ≥13 years. The disease severity was assessed on admission and daily throughout the hospitalisation. Test-positive individuals were considered as having "severe COVID-19" if they had ≥1 of the following: room air oxygen saturation 30 breaths/minute, signs of severe respiratory distress, or received mechanical ventilation and/or vasopressor therapy. Uni- and multi-variate analyses using SPSS Statistics Ver. 26 were performed.

RESULTS

We showed that age ≥ 60 years, BMI ≥ 30.0, presentation on days 7-12 of illness, and ≥1 comorbidity were associated with development of severe COVID-19. A scoring system based on the four variables is a useful COVID-19 risk assessment tool. A total score ≥2 had a sensitivity of 60.9%, specificity of 88.2%, positive predictive value of 37.8% and negative predictive value of 95.0%.

CONCLUSION

Development of preadmission triaging tool can help health care providers (HCPs) decide on the placement of test-positive individuals to appropriate isolation facilities according to the risk of developing severe COVID-19.

Effect of Early Adverse Events on Survival Outcomes of Patients with Metastatic Colorectal Cancer Treated with Ramucirumab

BACKGROUND

Studies of patients treated with bevacizumab and other vascular epithelial growth factor (VEGF) inhibitors have reported that hypertension adverse events (AEs) are associated with improved overall survival (OS) or progression-free survival (PFS).

OBJECTIVE

Our objective was to evaluate the association between early AEs and survival outcomes for patients treated with ramucirumab, an antibody targeting the VEGF receptor-2 (VEGFR-2), plus FOLFIRI for metastatic colorectal cancer (mCRC).

METHODS

Data from 529 patients treated with ramucirumab plus FOLFIRI for mCRC in the RAISE clinical trial (NCT01183780) were evaluated to see whether early (first 6 weeks of therapy) AEs predicted subsequent OS and PFS. A Cox proportional hazard approach was used to evaluate associations between early AEs and survival outcomes. A secondary analysis between FOLFIRI and placebo was conducted as a sensitivity analysis.

RESULTS

Of 529 patients treated with ramucirumab plus FOLFIRI, 479 were alive and progression free at 6 weeks after commencing therapy. No significant association was identified between hypertension occurring within the first 42 days of ramucirumab plus FOLFIRI therapy and OS (grade 1-2, hazard ratio [HR] 0.90 [95% confidence interval (CI) 0.66-1.24]; grade 3+, HR 1.02 [95% CI 0.67-1.55]; P = 0.803) or PFS (grade 1-2, HR 0.98 [95% CI 0.74-1.28]; grade 3+, HR 0.93 [95% CI 0.64-1.37]; P = 0.93). However, there was a significant association between diarrhea occurring within the first 42 days of ramucirumab plus FOLFIRI therapy and worse OS (grade 1-2, HR 0.96 [95% CI 0.76-1.20]; grade 3+, HR 2.72 [95% CI 1.67-4.44]; P = 0.001) and PFS (grade 1-2, HR 1.01 [95% CI 0.83-1.23]; grade 3+, HR 2.22 [95% CI 1.43-3.45]; P = 0.005). No other AEs were significantly associated with OS or PFS.

CONCLUSIONS

Ramucirumab-induced hypertension was not associated with improved OS and PFS in patients with mCRC treated with ramucirumab and FOLFIRI, but severe diarrhea was associated with poorer OS and PFS.

CLINICAL TRIAL REGISTRATION

No. NCT01183780.

Association of fatty acid composition in serum phospholipids with metabolic syndrome and arterial stiffness

BACKGROUND AND AIM

We examined the association of fatty acid (FA) composition in serum phospholipids with the features of metabolic syndrome (MetS) and arterial stiffness.

METHODS

Korean men (n = 593, 30-79 yrs) were categorized based on the number of MetS risk factors (RFs) and measured for the markers of MetS, serum phospholipid FA composition and brachial-ankle pulse wave velocity (baPWV), an index for the severity of arterial stiffness.

RESULTS

Insulin resistance (HOMA-IR), baPWV, LDL size, and adiponectin were significantly altered corresponding to the number of MetS RFs. The proportions of total monounsaturated FA, palmitoleic acid (16:1), oleic acid (18:1ω-9) and dihomo-γ-linolenic acid (DGLA, 20:3ω-6) in serum phospholipids, and DGLA/linoleic acid (LA) (20:3ω-6/18:2ω-6), deta9-desaturase activity (D9D-16: 16:1/16:0 and D9D-18: 18:1ω-9/18:0) significantly increased corresponding to the number of MetS RFs, but D5D (20:4ω-6/20:3ω-6) decreased. baPWV positively correlated with HOMA-IR, palmitic acid (16:0), oleic acid, D6D (18:3ω-6/18:2ω-6), DGLA/LA and D9D-18, and negatively with adiponectin, LDL size, LA, docosahexaenoic acid (DHA, 22:6ω-3) and D5D. Multiple stepwise regression models revealed that baPWV was significantly influenced by systolic blood pressure, age, body weight, triglyceride and LA in serum phospholipids (R(2) = 0.378). Interestingly, baPWV (1419 ± 1 cm/s) and MetS (22%) were highest in individuals with lower proportion of LA (< 12.361%) and higher proportion of DGLA (≥ 1.412%) in serum phospholipid FAs.

CONCLUSION

The features of MetS significantly related to serum phosopholipid FA composition. Particularly, arterial stiffness was associated with LA additively together with DLGA. It may suggest a potential benefit of sufficient amounts of LA in serum or in diet can reduce cardiovascular risk.

Optoacoustic induced vibrations within the inner ear

An acoustic transient can be generated inside an absorbing tissue as a result of laser-tissue interaction after pulsed laser irradiation. Herein we report a novel application of this physical process, the optoacoustic wave generation in the inner ear and subsequently the induction of basilar membrane vibrations. These laser induced vibrations show a direct correlation to the laser energy and an indirect correlation to the distance from the irradiation focus. Through these characteristics they may be used, in a new generation of cochlear implants, to improve the frequency specific cochlear activation and consequently improve speech perception in hearing impaired patients with residual hearing.

Atherogenecity of LDL and unfavorable adipokine profile in metabolically obese, normal-weight woman

OBJECTIVE

The relationship of visceral adiposity with adipocytokines and low-density lipoprotein (LDL) particle distribution and oxidation in Asian metabolically obese, normal-weight (MONW) individuals has not been evaluated. We aimed to investigate the association between visceral adiposity and adipocytokines and cardiovascular disease (CVD) risk factors in MONW Korean women with normal glucose tolerance.

METHODS AND PROCEDURES

We examined the metabolic characteristics of 135 non-obese (BMI <25 kg/m(2)) women aged 25-64 years. Twenty-five women (BMI <25 kg/m(2) and visceral fat adiposity (VFA) > or =100 cm(2)) were classified as MONW and 25 women (BMI <25 kg/m(2) and VFA <100 cm(2)), pair-matched for age, weight, height, and menopausal status, as control group. Plasma lipid profiles and adipocytokines were evaluated in these two groups.

RESULTS

MONW subjects had higher systolic (P < 0.05) and diastolic blood pressure (P < 0.005) and higher concentrations of triacylglycerol (TG) (P < 0.005), insulin (P < 0.01), and free fatty acid (FFA) (P < 0.05) than control subjects. There was no significant difference between two groups in LDL-cholesterol (LDL-C) concentrations; however, MONW subjects had smaller LDL particles (P < 0.01) and higher concentrations of oxidized LDL (ox-LDL) (P < 0.05) compared with controls. Moreover, MONW subjects had higher concentrations of tumor necrosis factor-alpha (TNF-alpha) (P < 0.05), interleukin-6 (IL-6) (P < 0.05) and leptin (P < 0.05), and lower plasma adiponectin concentrations (P < 0.05). Higher intake of saturated fat with lower ratio of polyunsaturated fatty acids (PUFAs) to saturated fatty acids (SFA) and lower fiber intake than normal subjects were found in MONW women.

DISCUSSION

We found an unfavorable inflammatory profile and a more atherogenic LDL profile in MONW female subjects even in the absence of a known CVD risk factors. Moreover, MONW consumed more saturated fat and less fiber than the control group.

Effects of phase duration and pulse rate on loudness and pitch percepts in the first auditory midbrain implant patients: Comparison to cochlear implant and auditory brainstem implant results

The auditory midbrain implant (AMI), which is designed for stimulation of the inferior colliculus (IC), is now in clinical trials. The AMI consists of a single shank array (20 contacts) and uses a stimulation strategy originally designed for cochlear implants since it is already approved for human use and we do not yet know how to optimally activate the auditory midbrain. The goal of this study was to investigate the effects of different pulse rates and phase durations on loudness and pitch percepts because these parameters are required to implement the AMI stimulation strategy. Although each patient was implanted into a different region (i.e. lateral lemniscus, central nucleus of IC, dorsal cortex of IC), they generally exhibited similar threshold versus phase duration, threshold versus pulse rate, and pitch versus pulse rate curves. In particular, stimulation with 100 mus/phase, 250 pulse per second (pps) pulse trains achieved an optimal balance among safety, energy, and current threshold requirements while avoiding rate pitch effects. However, we observed large differences across patients in loudness adaptation to continuous pulse stimulation over long time scales. One patient (implanted in dorsal cortex of IC) even experienced complete loudness decay and elevation of thresholds with daily stimulation. Comparing these results with those of cochlear implant and auditory brainstem implant patients, it appears that stimulation of higher order neurons exhibits less and even no loudness summation for higher rate stimuli and greater current leakage for longer phase durations than that of cochlear neurons. The fact that all midbrain regions we stimulated, which includes three distinctly different nuclei, exhibited similar loudness summation effects (i.e. none for pulse rates above 250 pps) suggests a possible shift in some coding properties that is affected more by which stage along the auditory pathway rather than the types of neurons are being stimulated. However, loudness adaptation occurs at multiple stages from the cochlea up to the midbrain.

Tophaceous gout causing atlanto-axial subluxation mimicking rheumatoid arthritis: a case report

This is a case report of an extremely rare condition of atlanto-axial subluxation secondary to gouty arthritis, which mimicked rheumatoid arthritis at presentation. Gouty arthritis involving the spine is a rare condition. We highlight a case of gouty arthritis involving the atlanto-axial joint resulting in joint instability, subluxation, and neurological deficit. A 66-year-old obese woman who had a polyarticular disease for the previous 3 years presented with neck pain and progressive neurology. A 2-stage procedure was performed: posterior decompression and occipitocervical fusion followed by further anterior trans-oral decompression. However, after an initial neurological improvement, she succumbed to aspirational pneumonia and septicaemia. Atlanto-axial subluxation caused by gouty arthritis can present in the same way as rheumatoid arthritis. Therefore, the possibility of this as a differential diagnosis should be kept in mind.

Coronal plane and apical vertebral rotation correction of adolescent idiopathic scoliosis with multisegmented hook-rod system--a retrospective review

Between April 1998 and December 1999, thirty patients with Idiopathic Scoliosis were operated with Multisegmented Hook-Rod System. These patients were operated at the mean age of 16 years and were followed up for a mean of 22.3 months (range 13-34 months). Seven patients had anterior release to increase the curve flexibility followed by second stage posterior instrumentation on the same day. The average operating time for a posterior instrumentation alone and anterior release combined with posterior instrumentation were 270 minutes and 522 minutes respectively. The average blood loss was 2.2 litres for posterior instrumentation alone and 3.3 litres for single day anterior release and posterior surgery. The mean preoperative Cobb's angle was 70 degrees. The mean immediate postoperative and final follow up Cobb's angles were 38 and 42 degrees, which represented an average coronal plane correction of 46.7% and 40.0% respectively. The mean preoperative apical vertebral rotation was 25 degrees, which improved to 15 degrees after the operation. At final follow up, the mean apical vertebra rotation was 20 degrees, which represented a mean apical vertebral rotation correction of 20%. Complications of the procedure included one transient neurological deficit, one infection, one graft site infection and one case of screw cut out. We were able to obtain satisfactory correction of idiopathic scoliosis with the Multisegmented Hook-Rod System.

Predicting significant hyperbilirubinaemia and early discharge for glucose-6-phosphate dehydrogenase deficient newborns

INTRODUCTION

This study aims to assess the usefulness of day 3 (49 to 72 hours) pre-phototherapy total serum bilirubin (TSB) in predicting subsequent significant hyperbilirubinaemia (SHB) and the feasibility of early discharge for term and near-term glucose-6-phosphate dehydrogenase (G6PD) deficient newborns.

MATERIALS AND METHODS

This prospective cohort study involved in born G6PD deficient neonates who were > or = 35 weeks and weighted > or = 2000 g at birth. TSB levels and phototherapy requirements in their first two weeks of life were studied. Day 3 pre-phototherapy TSB in the subgroup weighing > or = 2500 g at birth was analysed for its value in predicting subsequent SHB.

RESULTS

Of the 129 neonates, 58 (45%) required phototherapy in the first week. Of these, only 4 patients (3.1%) needed phototherapy to be restarted in the second week. Seventy-one (55%) neonates did not require phototherapy at all. In the absence of SHB in the first week, the probability of its development in the second week was zero (95% confidence interval, 0 to 0.057). In the subgroup weighing > or = 2500 g at birth, day 3 pre-phototherapy TSB < or = 154 umol/L predicted no measurable risk of subsequent SHB (sensitivity, 100%; 95% confidence interval, 91.4% to 100%; negative predictive value, 100%; 95% confidence interval, 86.7% to 100%).

CONCLUSIONS

G6PD deficient newborns without SHB in their first week of life were at no measurable risk of its development in the second week. Day 3 pre-phototherapy TSB in the subgroup weighing > or = 2500 g was useful for predicting the risk of subsequent SHB. Low-risk infants, thus identified, may be eligible for discharge on or before day 7 of life. Evidence-based early discharge can decrease the social and financial burden of G6PD deficiency in Singapore.

EMLA cream versus dorsal penile nerve block for postcircumcision analgesia in children

We conducted a prospective, randomized, double-blinded trial comparing preoperative application of EMLA cream and sodium chloride solution dorsal penile block (n = 31) with placebo cream and bupivacaine dorsal penile nerve block (n = 32) for postcircumcision analgesia. Pain was assessed using modified Children's Hospital of Eastern Ontario Pain Scale and the duration of block by the time to requirement of first dose of postoperative analgesic. There was no difference in Children's Hospital of Eastern Ontario Pain Scale between the two groups, but bupivacaine dorsal penile nerve block resulted in longer analgesia (P = 0.003). There were no local or systemic complications related to either technique, and there was a very small incidence of vomiting. We conclude that preoperative application of EMLA cream is an effective and simple method to produce postcircumcision analgesia with a very small incidence of adverse effects.

Respiratory conditions in Malaysian asbestos cement workers

A cross-sectional study was conducted to determine the prevalence and type of respiratory conditions including asbestos-related diseases among Malaysian asbestos cement workers. The study population consisted of 1164 workers who had undergone medical surveillance from 1995 to 1997, including full history, physical examination, chest radiography and spirometry. More than half the male workers were smokers or ex-smokers, with smokers having more respiratory symptoms and signs, and reduced FEV1 compared with non smokers. The five most common respiratory conditions diagnosed were bronchial asthma, chronic bronchitis, pulmonary tuberculosis, upper respiratory tract infections and allergic rhinitis. On follow-up, there were also two cases of asbestosis and one case of bronchial carcinoma. The asbestosis cases were probably related to heavy occupational exposure to asbestos fibres in the past, before governmental regulations were gazetted in 1986. Further follow-up is essential for continued monitoring of the health status of asbestos workers.

Early expressed Clb proteins allow accumulation of mitotic cyclin by inactivating proteolytic machinery during S phase

Periodic accumulation and destruction of mitotic cyclins are important for the initiation and termination of M phase. It is known that both APC(Cdc20) and APC(Hct1) collaborate to destroy mitotic cyclins during M phase. Here we show that this relationship between anaphase-promoting complex (APC) and Clb proteins is reversed in S phase such that the early Clb kinases (Clb3, Clb4, and Clb5 kinases) inactivate APC(Hct1) to allow Clb2 accumulation. This alternating antagonism between APC and Clb proteins during S and M phases constitutes an oscillatory system that generates undulations in the levels of mitotic cyclins.

Intercostal nerve neurotization of the femoral nerve in patients with paraplegia--an anatomical feasibility study

Neurotization of the brachial plexus is an established procedure in the upper limb. However, neurotization of the lower limb remains experimental. Brunelli reported the use of the ulnar nerve to neurotize the lower limb. Zhao et al reported the use of intercostals nerve to neurotize the lower limb in rats. The aim of the study was to determine the feasibility of using intercostals nerve to neurotize the femoral nerve in human cadavers and to ascertain the ideal intercostals nerve that has the anatomical course that suit this role. Six fresh cadaveric dissection were performed through an extensile midline incision in the postmortem room and the lower six (T7-T12) were identified and traced from their origin. Their length and course identified and charted. T9 and T10 intercostal nerve was thought to be the most suitable nerve as the donor nerve, and the T11 and T12 intercostal nerve could not be free from its intra-muscular course sufficiently to be use as donor.

Delayed decompression of chronic C1C2 subluxation in a pediatric patient with tetraplegia--is recovery possible?

A 2 year-old Malay girl was admitted to our institution with a chesty cough and breathlessness but later found to have a chronic C1/C2 subluxation for one and half year with tetraplegia. Her cervical cord was decompressed and occipito-cervical fusion performed. Her neurological status improved significantly post-operatively and is able to care for her personal hygiene. The authors believe that the ability of the cervical cord to recover in the paediatric age group is remarkable that surgical option should be considered even when all seen lost. We believe that this is the first report in the literature to support this potential.

Dynamic measurement of axial vertebral rotation and rotational flexibility in scoliosis by flouroscopic method

The Pedriolle torsion meter is an established method of vertebral rotation assessment in scoliosis. However, the assessment of scoliosis by this method is static and indirect. The objective of this study is to compare the accuracy of a direct method of assessing scoliosis rotation by fluoroscopy compared to the Pedriolle torsion meter. Secondly, to determine that vertebral body rotation changes with supine posture compared to erect position. Eight volunteers with idiopathic scoliosis were assessed for the apical vertebral rotation with this method and the Pedriolle torsion meter. These patients were also assessed in the supine and erect position with the fluoroscopic method to determine if the apical vertebral rotation would change with posture. The mean Cobb angle of the curves was 62.8 degrees (range 45 degrees to 86 degrees). The mean apical vertebral rotation in a standing position was assessed to be 21.5 degrees by Pedriolle torsion meter and 29 degrees by the fluoroscopic method. This difference was not statistically significant by the student t-test. In most patient, the rotation of vertebrae improved by a varying degree ranging from none to 24 degrees in the supine position. In conclusion, the fluoroscopic method is an alternate mean of measuring vertebrae rotation in idiopathic scoliosis, with comparable accuracy to the Pedriolle torsion meter method. The amount of vertebral rotation changes with posture of the patient.

Life and death cell labeling in the microcirculation of the spontaneously hypertensive rat

Spontaneously hypertensive rats (SHRs) have elevated numbers of apoptotic cells. However, the extent and pattern of cell death at the microvascular level is unexplored. We developed a technique to determine early forms of cell death in vivo in the mesentery by use of the life/death indicator ethidium bromide (EB). The mesenteric microvasculature was superfused with 5 microM EB for a period of 3 min, rinsed and immediately viewed by digital fluorescence microscopy. EB-positive cell structures were observed both in the wall of microvessels as well as in the tissue parenchyma. The microvessels had about 2--4 EB-positive cell structures per 100 microm of vessel length. Larger arterioles (>25 microm) in the SHR had an increased EB-positive structure density. After normalization of the blood pressure in the SHR with adrenalectomy, no significant differences remained between Wistar-Kyoto (WKY) rats and SHRs. After dexamethasone treatment, the adrenalectomized SHRs had a higher EB-positive cell density in the smaller class of microvessels than the WKY rats. In addition, EB-positive cell fragments (0.5--2 microm) were observed in the mesentery microvessel wall, and with TUNEL labeling, they were demonstrated to represent DNA fragments. The percentage of microvessels with EB-positive fragments was higher in the SHR arterioles and capillaries. Capillaries and larger venules (>30 microm) in the SHR had higher levels of cell fragments per vessel length. After adrenalectomy, no significant differences remained between WKY rats and SHRs in any of the microvessel categories. When adrenalectomized rats were treated with dexamethasone, a higher number of EB-positive fragments was detected in the wall of SHR capillaries. These results indicate that the mesentery microcirculation in both strains is subject to an early and nonuniform pattern of cell death, as detected by EB, but is enhanced in selected individual microvascular segments of the SHR by a glucocorticoid-driven mechanism.

Analysis of proteoglycan gene messages in human nasal mucosa and nasal polyp using dot blot hybridization

It has been suggested that the formation and growth of nasal polyp require the remodeling of extracellular matrix. Proteoglycans (PGs) are major components of the extracellular matrix that maintain the integrity of structural tissue. The leucine-rich repeat PGs include lumican, decorin and biglycan and have many important biologic activities in various pathologic conditions, including the remodeling of the extracellular matrix. Therefore, these small-PG families may be involved in the formation and growth of nasal polyp. In the present study, surgical specimens of nasal polyps and nasal mucosa were assessed for expression of mRNA coding for lumican, decorin and biglycan using reverse transcriptase-polymerase chain reaction followed by dot blot hybridization. Lumican, decorin and biglycan mRNA were expressed in all tissue samples examined. Semiquantitative dot blot hybridization revealed that the levels of the lumican and biglycan messages are lower in nasal polyp tissues than in nasal mucosa. The decorin messages in nasal polyp were expressed at levels similar to those in nasal mucosa. These results suggest that lumican, decorin and biglycan may be important components of the extracellular matrix in nasal mucosa. Considering the function of these PGs, normal levels of decorin associated with low levels of biglycan and lumican may play a role in the pathogenesis of nasal polyposis.

Traumatic posterior rotatory fracture-dislocation of lumbo-sacral spine

Fracture-dislocation of the lumbo-sacral spine was an unusual injury and was divided into anterior, posterior and lateral types depending on the displacement of the cephalad portion of the spine over the caudal portion. According to the authors' knowledge, only 31 cases of traumatic fracture-dislocation of the lumbo-sacral spine were reported in the English literature. Only 3 previous reports referred to this injury with a posterior displacement, which was an even rarer injury. This was the fourth report of this type of injury.

Expression patterns of p27Kip1 and Ki-67 in cholesteatoma epithelium

OBJECTIVES

The cell cycle must be involved in cell proliferation of the epithelium of middle ear cholesteatoma Cyclins and cyclin-dependent kinase (CDK) complexes have important regulatory roles during cell cycle progression. Cyclin-CDK complexes are in turn regulated by the cyclin-dependent kinase inhibitors (CDKIs), which generally inhibit cell cycle progression. One of the important CDKI members is p27(Kip1). The goal of this study is to evaluate the expression of p27(Kip1) and Ki-67, a proliferation marker, in cholesteatoma and in the skin of the external ear canal.

METHODS

The expressions of p27(Kip1) and Ki-67 in cholesteatoma epithelium (n = 20) and ear canal epithelium (n = 7) were investigated by an immunohistochemical technique.

RESULTS

In cholesteatoma epithelium specimens, the expression of p27(Kip1) was observed from the parabasal layer to the granular layer, but not in the basal layer. Ki-67 was expressed dominantly in the basal and parabasal cell layers. Their expressions tend to be increased compared with their expressions in the normal ear canal skin. The expression pattern of the proliferation marker Ki-67 in the epithelial layers of two groups was inversely related to the expression of p27(Kip1).

CONCLUSIONS

In cholesteatoma, the expressions of CDKI and Ki-67 were both increased in this study. The ability to inhibit proliferative activity was also increased in the cholesteatoma epithelium. The expression pattern of the proliferation marker Ki-67 in the epithelial layers was inversely related to the expression of p27(Kip1). Not only is the proliferation activity increased, but also the ability to inhibit hyperproliferation is increased in the cholesteatoma epidermis. Despite increased proliferative activity in the cholesteatoma epidermis, epithelial cells still retain the capability to prevent cell cycle arrest by means of p27(Kip1).

The use of intravenous atropine after a saline infusion in the prevention of spinal anesthesia-induced hypotension in elderly patients

We investigated the efficacy of IV atropine for preventing spinal anesthesia-induced hypotension in elderly patients. Seventy-five patients undergoing transurethral prostate or bladder surgery were randomized to receive either placebo (n = 25), atropine 5 microg/kg (small-dose atropine, n = 25) or atropine 10 microg/kg (large-dose atropine, n = 25) after the induction of spinal anesthesia. All the patients received an IV infusion of 10 mL/kg 0.9% normal saline over 10 min before the induction of anesthesia. The systolic blood pressure decreased in all three groups after spinal anesthesia. There was a significant increase in the mean heart rate in both atropine groups as compared to the placebo group (placebo group: 78 bpm, 95% confidence interval [CI]: 76.6-78.5; small-dose atropine group: 86 bpm, 95% CI 83.9-88.8; large-dose atropine group: 97 bpm, 95% CI 94.5-100.3; P: = 0.001). There was a significant decrease in the incidence of hypotension in patients who received atropine (placebo group: 76%, small-dose atropine group: 52%, large-dose atropine group: 40%, P: = 0.03). The mean dose of ephedrine required was significantly decreased in the atropine groups (placebo group: 12.2 mg [SD= 10.5], small-dose atropine group: 7.4 mg [SD= 10.0], large-dose atropine group: 5.4 mg [SD= 8.7 mg], P: = 0.048). The total amount of IV fluid and number of patients requiring metaraminol in addition to 30 mg of ephedrine were not significantly different among the three groups. Significant side effects, such as confusion, ST segment changes or angina were not detected in any of the patients. We conclude that IV atropine may be a useful supplement to the existing methods in preventing hypotension induced by spinal anesthesia.

IMPLICATIONS

IV atropine increases heart rate in a dose-dependent manner in elderly patients undergoing spinal anesthesia. It reduces the incidence of hypotension and the dose of ephedrine required. Small-dose atropine may be a useful supplement in preventing spinal anesthesia-induced hypotension in elderly patients.

Clinical experiences with acute mastoiditis--1988 through 1998

The incidence of acute mastoiditis has declined dramatically during the postantibiotic era. Even so, antibiotic-resistant or unusual pathogens can still cause this disease entity. At our hospital, we documented an increase in antibiotic-resistant and atypical pathogens such as Actinomyces spp. and Mycobacterium tuberculosis. In this paper, we discuss the optimal diagnosis and treatment strategy for acute mastoiditis, and we describe our retrospective review of 13 patients with mastoiditis who were treated at our hospital from 1988 through 1998. Eight of these patients recovered following treatment with intravenous antibiotics, with or without myringotomy, and five who had complications of disease were managed surgically. Among these five, one developed chronic otitis media and one developed cholesteatoma 3 years later. For patients with acute mastoiditis, we emphasize the need to be aware of any unusual pathogens that do not respond to empiric antibiotic therapy.

Protective role of superoxide dismutase in rat eustachian tubal mucosa against acute otitis media induced by upper respiratory tract infection

Superoxide dismutase has been known to play a role as an anti-oxidative system against oxidative injury during acute inflammation. To investigate the role of superoxide dismutase in eustachian tubal mucosa during acute otitis media (AOM), an animal model was made. Sprague-Dawley rats were inoculated with Streptococcus pneumoniae through the nasal cavity following development of virus-induced upper respiratory infection. The animals were divided into three groups according to their tympanic cavity conditions following bacterial inoculation; inoculated animals with no resultant AOM (no-AOM), animals with resultant AOM (AOM) and animals with resolving otitis media (recovery). The changes of superoxide dismutase in each tubal mucosa were compared with that of the normal control using immunohistochemistry and immunoblotting methods. On Western blot, there were little changes of optical density and surface area in no-AOM (213.5 +/- 22.4, 13.2 +/- 0.8 mm2) and recovery group (219.3 +/- 18.7, 14.8 +/- 0.7 mm2) compared to the normal control (223.5 +/- 26.2, 16.7 +/- 0.4 mm2). However, a marked decrease was found in the AOM model (167.6 +/- 19.3, 6.5 +/- 0.9 mm2). These findings suggest that superoxide dismutase may play a role in protecting tubal mucosa from free radical injury during AOM.

Changes in cochlear electrical stimulation induced Fos expression in the rat inferior colliculus following deafness

Fos immunoreactive (IR) staining was used to examine changes in excitatory neuronal activity in the rat inferior colliculus (IC) between normal hearing and 21 day deaf rats evoked by basal or apical monopolar cochlear electrical stimulation. The location of evoked Fos IR neurons was consistent with expected tonotopic areas. The number of Fos IR cells increased as stimulation intensity increased in both normal and 21 day deaf animals. Stimulation at 1. 5x threshold evoked fewer Fos IR cells in 21 day deafened animals compared to normal hearing animals. At 5x and above, however, significantly increased numbers of Fos IR neurons (in a larger grouping) were evoked in 21 day deafened animals compared to normal hearing animals. Another group of animals had 7 days of deafness followed by 14 days of chronic basal cochlear electrical stimulation. In this group basal monopolar stimulation at 5x evoked not only a greater number of Fos IR neurons, compared to normal hearing animals, but the location of their grouping was slightly shifted to a more dorso-lateral region in the contralateral IC, compared to the normal hearing and 21 day deaf groups. These observations indicate that both deafness and chronic electrical stimulation may alter central auditory processing.

Selective thoracic fusion of King II scoliosis with segmental spinal instrumentation

Segmental spinal instrumentation with Harrington rod secured to the spine by sublaminar wires was a popular method of scoliosis correction in 1980's. It was gradually replaced by newer rod-hook systems due to concern about neurological complications. However, correction of type II and III curves by selectively fusing the thoracic curves with these new instruments has resulted in poor results in some cases. The aim of this study is to review the result of selective thoracic fusion treated by segmental spinal instrumentation. Between January 1989 to October 1994, 31 patients with King II scoliosis were treated operatively in our unit. These consisted of 29 girls and 2 boys. The mean age of these patients were 11.3 years. The study population consisted of 21 Chinese, 5 Malays and 5 Indians. In one patient, the thoracic curve was convex to the left whilst the thoracic curves in the majority were to the right. The surgery was performed by three surgeons using harrington rods and posterior fusion with autograft. Anterior releases were also required in eight patients to increase flexibility. The curve correction obtained was an improvement from a average preoperative cobb's angle of 71.5 degrees to 39.5 degrees postoperatively. After an average follow-up period of 77.9 months, the correction deteriorated by 22% in the thoracic curve and 59% in the lumbar spine without disturbance to truncal balance. Only one sublaminar wire broke. However, no implant failure or removal has to be performed as yet. This technique appears useful in our institution with minimal morbidity.

External quality assurance in Malaysia

An activity supportive of the MOH QA Programme, the National EQAS for clinical chemistry monitors for analytical performance in core routine biochemical testing by the pathology laboratories, with unsatisfactory performance scores serving to alert against deficiencies or problems and the scores in subsequent challenges providing the feedback of effectiveness of remedial actions taken. While unacceptable individual analyte performance score (variance index score, VIS) indicated problems in instruments, reagent and calibrators, or the use of inherently poorer methods, repeated occurrence of unsatisfactory OMRVIS was traceable to generally poor laboratory management of usually inadequately-equipment small laboratories. The outcome has been one of slow but gradual improvement in the overall performance of participating laboratories, with a move towards methods upgrading and standardization to achieve greater concordance of results. Presently, the programme is limited to 61 government and 4 private hospital laboratories in the country for 12 commonly assayed clinical biochemistry analytes. It is hoped that the NEQAS could be extended to the other private laboratories and that of academic institutions. However, this is dependent to a large extent on the manpower and financial support obtainable by the organizing body of the programme in the future. Belk and Sunderman, 1947 demonstrated that laboratories participating in an quality assessment scheme could rapidly and dramatically improve their analytical performance. In some countries, participation has become mandatory, and acceptable performance is a requirement in laboratory accreditation. The need and value of the NEQAP is, therefore, evident. While there may be limitations in the national programme. efforts are being made at improving the programme within the means and resources of the organising body. The goals of the NEQAP are not just to monitor performance but also to educate. On this, matters related to and supportive of these goals have also been pursued. The annual workshop/forum on quality controls had allowed exchange of information between representatives of participating laboratories and the organising body. Recently in the 1997 MOH Quality Improvement evaluation, Quality Control has been evaluated together with the other 17 such activities. The study on knowledge, attitude and practice has provided the necessary feedback and will be used for future planning in making efforts at increasing the effectiveness and benefits of the all QC activities including this NEQAP for clinical chemistry. In addition, there is a need to look into areas such as selection of methods and test systems, and improvement of continuing education, training as well as research in quality improvement as suggested by the Quality Improvement evaluation.

Olfactory mucosal findings in patients with persistent anosmia after endoscopic sinus surgery

Sixty-three biopsy specimens were obtained from the olfactory region of 15 patients with persistent anosmia and 6 patients with normosmia after sinus surgery. Immunohistochemical examination of all specimens with microtubule-associated protein 5 (MAP5) antisera demonstrated olfactory epithelium in 11 of 18 specimens from normosmic patients and in 12 of 45 samples from anosmic patients. There was a significant difference in the proportion of specimens containing olfactory epithelium between the two groups of patients. In normosmic patients, most of the biopsy samples contained normal-appearing olfactory tissue. However, 2 main patterns of histologic findings were noted in the olfactory mucosa of anosmic patients. First, the olfactory receptor cells were remarkably decreased in number. Second, the orderly arrangement of cells characteristic of normal olfactory epithelium was lost, demonstrating a degenerative appearance. These data suggest that olfactory epithelium can be degenerated even in chronic sinusitis and thereafter extensively replaced with respiratory epithelium, resulting in increased sampling error. Moreover, an unimproved olfactory deficit after sinus surgery may be due to the abnormalities observed at the olfactory epithelium level.

The operative treatment of closed tibial fractures

The tibia is a subcutaneous bone. Operative fixation of tibial fractures is a demanding undertaking. Thirty-five patients with 36 tibial fractures were admitted to our institution between May 1995 and April 1996. The patients were predominantly male (male to female ratio of 4) and the average age of the patients was 31.4 years (range 14 to 67 years). Ten fractures were located in the proximal third, 18 in the middle third and 8 in the distal third. The indications for operation included displaced intra-articular fragments, failed conservative treatment, compartment syndrome, multiple fractures and unstable fracture configuration. Operative procedures included plating in 29 cases and nailing in 7 cases. These patients were reviewed retrospectively and assessed for complications and radiological and functional outcome. The overall results were satisfactory in 88.9% and poor in 11.1%. The complications were reviewed and various factors affecting the incidences analysed. Three deep infections occurred. All were found after discharge from inpatient care. A prolonged interval between admission and surgery as well as high energy of impact are thought to be the main contributing factors.

Exit from mitosis in budding yeast: biphasic inactivation of the Cdc28-Clb2 mitotic kinase and the role of Cdc20

Cdc20, an activator of the anaphase-promoting complex (APC), is also required for the exit from mitosis in Saccharomyces cerevisiae. Here we show that during mitosis, both the inactivation of Cdc28-Clb2 kinase and the degradation of mitotic cyclin Clb2 occur in two steps. The first phase of Clb2 proteolysis, which commences at the metaphase-to-anaphase transition when Clb2 abundance is high, is dependent on Cdc20. The second wave of Clb2 destruction in telophase requires activation of the Cdc20 homolog, Hct1/Cdh1. The first phase of Clb2 destruction, which lowers the Cdc28-Clb2 kinase activity, is a prerequisite for the second. Thus, Clb2 proteolysis is not solely mediated by Hct1 as generally believed; instead, it requires a sequential action of both Cdc20 and Hct1.

Expression of vascular endothelial growth factor in otitis media

Increased vascular permeability and endothelial cell growth are important in the pathogenesis of otitis media with effusion (OME) and the vascular endothelial growth factor (VEGF) is known to play an important role in the increased vascular permeability and angiogenesis. To date, at least five isoforms of the VEGF family have been identified as VEGF transcripts, encoding polypeptides of 206, 189, 165, 145 and 121, but their physiological roles are unclear. The purpose of this study was to investigate the expression of VEGF, in both endotoxin-induced OME of the rat and human otitis media. We instilled endotoxin and saline as a control into the middle ear cavity of the rat. Middle ear mucosa were taken at 0 h, 1 h, 3 h, 6 h, 12 h, 1 day, 3 days, 7 days and 14 days and the expression of VEGF mRNA and VEGF protein was evaluated using semi-quantitative RT-PCR and immunohistochemistry. Expression of VEGF164 mRNA and VEGF120 mRNA was first identified 1 h after endotoxin instillation and was dramatically increased over the period 6 h-1 day and then progressively decreased by day 7. The level of expression of VEGF120 mRNA was slightly higher than that of VEGF164 mRNA and that of VEGF164 mRNA was much higher than that of VEGF188 mRNA. Immunostaining revealed expression of VEGF during 6 h to day 3 and its expression was localized to ciliated cells and some inflammatory cells. We also performed RT-PCRs of cDNA from middle ear fluids of 8 human OME patients and middle ear mucosa of 4 chronic otitis media patients for the identification of VEGF mRNA expression. VEGF121 mRNA was highly expressed in all samples compared with VEGF165 mRNA. These results suggest that VEGF may be primarily responsible for increased vascular permeability and endothelial cell growth in OME and that VEGF seems to play a significant role in the pathogenesis of OME.

Cdc20 protein contains a destruction-box but, unlike Clb2, its proteolysisis not acutely dependent on the activity of anaphase-promoting complex

Both chromosome segregation and the final exit from mitosis require a ubiquitin-protein ligase called anaphase-promoting complex (APC) or cyclosome. This multiprotein complex ubiquitinates various substrates, such as the anaphase inhibitor Pds1 and mitotic cyclins, and thus targets them for proteolysis by the 26S proteasome. The ubiquitination by APC is dependent on the presence of a destruction-box sequence in the N-terminus of target proteins. Recent reports have strongly suggested that Cdc20, a WD40 repeat-containing protein required for nuclear division in the budding yeast Saccharomyces cerevisiae, is essential for the APC-mediated proteolysis. To understand the function of CDC20, we have studied its regulation in some detail. The expression of the CDC20 gene is cell-cycle regulated such that it is transcribed only during late S phase and mitosis. Although the protein is unstable to some extent through out the cell cycle, its degradation is particularly enhanced in G1. Cdc20 contains a destruction box sequence which, when mutated or deleted, stabilizes it considerably in G1. Surprisingly, we find that while the inactivation of APC subunits Cdc16, Cdc23 or Cdc27 results in stabilization of the mitotic cyclin Clb2 in G1, the proteolytic destruction of Cdc20 remains largely unaffected. This suggests the existence of proteolytic mechanisms in G1 that can degrade destruction-box containing proteins, such as Cdc20, in an APC-independent manner.

Expression of human beta-defensin 1 mRNA in human nasal mucosa

Antimicrobial peptides are cationic proteins that are found in a wide range of organisms. Recent reports suggested that human beta-defensin 1 (hBD-1), a prominent group of antimicrobial peptides, is an important component of the innate immune response, particularly at mucosal surfaces that are vulnerable to colonization by potential pathogens. Therefore, hBD-1 may participate in providing intrinsic nasal mucosal defence against microbial infections. The present study aimed to look for hBD-1 mRNA in human nasal mucosa without obvious signs of inflammation. Total RNA was isolated from human inferior turbinate mucosa and hBD-1 mRNA was detected in these tissues by using reverse transcription and polymerase chain reaction (RT-PCR). By in situ hybridization, hBD-1 mRNA was predominantly localized in superficial epithelial cells and submucosal glandular epithelium of human inferior turbinate mucosa. These data suggest that nasal epithelia and submucosal glands may secrete hBD-1, contributing to the mucosal defences of the nose.

Identification and characterization of a putative C. elegans potassium channel gene (Ce-slo-2) distantly related to Ca(2+)-activated K(+) channels

Two putative homologues of large conductance Ca(2+)-activated K(+) channel alpha-subunit gene (slowpoke or slo) were revealed by C. elegans genome sequencing. One of the two genes, F08B12.3 (Ce-slo-2), shows a relatively low amino acid sequence similarity to other Slo sequences and lacks key functional motifs, which are important for calcium and voltage sensing. However, its overall structure and regions of homology, which are conserved in all Slo proteins, suggest that Ce-SLO-2 should belong to the Slo channel family. We have cloned a full-length cDNA of the Ce-slo-2, which encodes a protein containing six putative transmembrane segments with a K(+)-selective pore and a large C-terminal cytosolic domain. Green fluorescent protein (GFP) and whole-mount immunostaining analyses revealed that Ce-slo-2 is specifically expressed in neuronal cells at the nerve ring, at the ventral nerve cord of the mid-body, and at the tail region. We have also identified a putative human counterpart of Ce-slo-2 from a human brain EST database, which shows a stretch of highly conserved amino acid residues. Northern blot and mRNA dot blot analyses revealed a strong and specific expression in brain and skeletal muscle. Taken together, our data suggest that Ce-slo-2 may constitute an evolutionarily conserved gene encoding a potassium channel that has specific functions in neuronal cells.

Scoliosis in a patient with lipodystrophy--treatment difficulties and literature review

A 12 year-old Chinese schoolgirl presented with left-sided scoliosis at the age of 9 years. She has a rare defect in lipid metabolism, which is not known to be associated with spinal deformity. Her scoliotic curve deteriorated despite bracing. We report a rare occurrence of scoliosis in patient with lipodystrophy and the difficulty of using instrumented fusion in treating this condition.

Asbestosis in Malaysia: report on first two cases

The first two cases of asbestosis in Malaysia are reported. Both had considerable occupational exposure to asbestos dust in the past, with a long latency period exceeding 30 years. One case presented with distinctive clinical and radiological features, while the other case was only confirmed by histological diagnosis. The usefulness of modern investigation techniques such as CT scan in the diagnosis of asbestosis is also illustrated.

Cdc20 is essential for the cyclosome-mediated proteolysis of both Pds1 and Clb2 during M phase in budding yeast

Chromosome separation during the cell-cycle transition from metaphase to anaphase requires the proteolytic destruction of anaphase inhibitors such as Pds1 [1-3]. Proteolysis of Pds1 is mediated by a ubiquitin-protein ligase, the anaphase-promoting complex (APC) or cyclosome [4,5]. The APC is also necessary for the ubiquitin-dependent degradation of mitotic cyclins in late telophase as cells exit mitosis [6-9]. Although phosphorylation seems to be involved [10], it is not clear what activates the APC at the onset of anaphase. In Saccharomyces cerevisiae, chromosome segregation also requires the CDC20 gene, whose product contains WD40 repeats [11,12]. We have investigated the functional relationship between the APC and the Cdc20 protein. We present evidence that strongly suggests that Cdc20 is an essential regulator of APC-dependent proteolysis such that in the absence of Cdc20, cells are unable to degrade either Pds1 at the onset of anaphase or the mitotic cyclin Clb2 during telophase. This notion is consistent with our observations that Cdc20 is localized in the nucleus and co-immunoprecipitates with an APC component, Cdc23.

Uncemented total hip replacements using the Mecron acetabular cup--a prospective study

The uncemented threaded cup gained some popularity over the past decade, firstly as a revision and then as a primary procedure. We elected to test the Mecron acetabular threaded cup system as a routine hip replacement. As there was no matched femoral component, we decided to use an uncemented femoral stem of the Ring system of the hip prosthesis. All patients were logged on to the study at the outset although this is not a controlled comparison with another system. Patients were assessed annually for up to 4-years at the time of reporting. There were 104 primary total hip replacements in 99 patients between 1987 and 1991. The mean follow-up for this report was 22.5 months (range 12 to 48 months). The mean age was 76.3 years (range 24 to 88 years) and the female to male sex ratio was 3.3:1. Within the study period, 5 hips required revision, all for acetabular loosening. Patients were assessed by the modified Harris score annually and 60.6% of the cases had an excellent or good short-term result. Poor results were observed in 18.3% of cases. Radiographic studies of the acetabular component were undertaken annually and measured. Migration and tilting of the acetabular cup was observed in all cases. Heterotropic bone formation occurred in 10 patients. As a result of these poor results, the prosthesis was abandoned in 1991. The cohort of patients continues to be followed. Failure of the Mecron acetabular cup in our series was mainly due to tilting and migration and not untwisting.

Cdc20, a beta-transducin homologue, links RAD9-mediated G2/M checkpoint control to mitosis in Saccharomyces cerevisiae

In the budding yeast Saccharomyces cerevisiae, the DNA damage-induced G2 arrest requires the checkpoint control genes RAD9, RAD17, RAD24, MEC1, MEC2 and MEC3. These genes also prevent entry into mitosis of a temperature-sensitive mutant, cdc13, that accumulates chromosome damage at 37 degrees C. Here we show that a cdc13 mutant overexpressing Cdc20, a beta-transducin homologue, no longer arrests in G2 at the restrictive temperature but instead undergoes nuclear division, exits mitosis and enters a subsequent division cycle, which suggests that the DNA damage-induced G2/M checkpoint control is not functional in these cells. This is consistent with our observation that overexpression of CDC20 in wild-type cells results in increased sensitivity to UV irradiation. Overproduction of Cdc20 does not influence the arrest phenotype of the cdc mutants whose cell cycle block is independent of RAD9-mediated checkpoint control. Therefore, we suggest that the DNA damage-induced checkpoint controls prevent mitosis by inhibiting the nuclear division pathway requiring CDC20 function.

Spindle pole body separation in Saccharomyces cerevisiae requires dephosphorylation of the tyrosine 19 residue of Cdc28

In eukaryotes, mitosis requires the activation of cdc2 kinase via association with cyclin B and dephosphorylation of the threonine 14 and tyrosine 15 residues. It is known that in the budding yeast Saccharomyces cerevisiae, a homologous kinase, Cdc28, mediates the progression through M phase, but it is not clear what specific mitotic function its activation by the dephosphorylation of an equivalent tyrosine (Tyr-19) serves. We report here that cells expressing cdc28-E19 (in which Tyr-19 is replaced by glutamic acid) perform Start-related functions, complete DNA synthesis, and exhibit high levels of Clb2-associated kinase activity but are unable to form bipolar spindles. The failure of these cells to form mitotic spindles is due to their inability to segregate duplicated spindle pole bodies (SPBs), a phenotype strikingly similar to that exhibited by a previously reported mutant defective in both kinesin-like motor proteins Cin8 and Kip1. We also find that the overexpression of SWE1, the budding-yeast homolog of wee1, also leads to a failure to segregate SPBs. These results imply that dephosphorylation of Tyr-19 is required for the segregation of SPBs. The requirement of Tyr-19 dephosphorylation for spindle assembly is also observed under conditions in which spindle formation is independent of mitosis, suggesting that the involvement of Cdc28/Clb kinase in SPB separation is direct. On the basis of these results, we propose that one of the roles of Tyr-19 dephosphorylation is to promote SPB separation.

Dephosphorylation of threonine 169 of Cdc28 is not required for exit from mitosis but may be necessary for start in Saccharomyces cerevisiae

Entry into mitosis requires activation of cdc2 kinase brought on by its association with cyclin B, phosphorylation of the conserved threonine (Thr-167 in Schizosaccharomyces pombe) in the T loop, and dephosphorylation of the tyrosine residue at position 15. Exit from mitosis, on the other hand, is induced by inactivation of cdc2 activity via cyclin destruction. It has been suggested that in addition to cyclin degradation, dephosphorylation of Thr-167 may also be required for exit from the M phase. Here we show that Saccharomyces cerevisiae cells expressing cdc28-E169 (a CDC28 allele in which the equivalent threonine, Thr-169, has been replaced by glutamic acid) are able to degrade mitotic cyclin Clb2, inactivate the Cdc28/Clb2 kinase, and disassemble the anaphase spindles, suggesting that they exit mitosis normally. The cdc28-E169 allele is active with respect to its mitotic functions, since it complements the mitosis-defective cdc28-1N allele. Whereas replacement of Thr-169 with serine affects neither Start nor the mitotic activity of Cdc28, replacement with glutamic acid or alanine renders Cdc28 inactive for Start-related functions. Coimmunoprecipitation experiments show that although Cdc28-E169 associates with mitotic cyclin Clb2, it fails to associate with the G1 cyclin Cln2. Thus, an unmodified threonine at position 169 in Cdc28 is important for interaction with G1 cyclins. We propose that in S. cerevisiae, dephosphorylation of Thr-169 is not required for exit from mitosis but may be necessary for commitment to the subsequent division cycle.

Age-related changes of IgA immunocytes and serum and salivary IgA after tonsillectomy

For determining treatment options of tonsillar diseases, the authors compared immunohistochemical differences for IgA immunocytes and measured the changes in concentrations of the serum immunoglobulin A and salivary secretory immunoglobulin A before and after tonsillectomy according to age in 126 cases (60 control cases, 66 tonsillectomy cases). The serum IgA and salivary SIgA concentrations of the control group reached to adult's level at the age of 11 to 13. In the tonsillectomies, the serum IgA concentrations below the age of 10 were higher than that of controls and were decreased to the levels of the controls after tonsillectomy in all ages and the salivary SIgA concentrations were decreased to the levels of the controls at the 30th postoperative day, especially at the age of 5 to 7 and 8 to 10. Morphometric features of tonsils in the group below the age of 8 were more active than those in the group above the age of 8 in the controls. In the tonsillectomies, morphometric features of the tonsils were similar to those in the group above the age of 8, but the reticular part of the crypt epithelium remained significantly. Total number of IgA immunocytes was the highest at the age of 5 to 7 with a decline by age, especially at the age of 19 in the controls. In the tonsillectomy group, the number of IgA immunocytes of the extrafollicular area and the reticular part of crypt epithelium decreased below the levels of the control group. In conclusion, tonsils in preschool children are important as a local immunologic defense mechanism, but no significant changes in the immunologic system occurs after tonsillectomy.

Review of results of ankle fracture fixation in Alexandra Hospital (Singapore) between January 1987-April 1990

In 67 consecutive cases of ankle fracture treated operatively in Alexandra Hospital in Singapore, 35 ankles (53.7%) were available for review of the post-operative results. Thirteen fractures were of AO type A, 13 were type B and 9 type C. These patients had a minimum follow-up period of 16 months. They were assessed subjectively with a questionnaire and objectively by measuring the ankle movements. Good or excellent subjective results were obtained in 71% of the patients, while functional ankle scores were good or excellent in 88.5% of cases. Some restriction of ankle motion was present in 33.9% of patients. Difficulty in squatting was the most common complaint.

Bilateral acute haemangioma of the knee

Recurrent knee swelling is a common orthopaedic problem which sometimes can be a diagnostic enigma. We report a case of bilateral haemangioma of the knee, which presented clinically after trauma, as an unusual cause of knee swelling. This case demonstrates the therapeutic difficulties in surgical treatment of an haemangioma and emphasises the need for complete excision of this lesion. We further postulate that the aetiology of these lesions was possibly a result of trauma initiated growth of pre-existing haemangiomata.

Operative treatment of acetabular fractures

A retrospective review of 23 patients with acetabular fractures operated upon between January 1985 and December 1990 was conducted. Eighteen patients were available for assessment of functional outcome. Radiological results were also evaluated. The majority of the patients were male and the average age was 35 years. Three-quarters of the patients had an injury to another system. Three-quarters of the patients were operated upon within two weeks and only two patients had complications directly related to the operation. Radiological result was excellent or good in 61%, fair in 22%, and poor in 16% of the patients. Functional score was excellent or good in 72%, fair in 16% and poor in 11%. In summary, operative treatment of acetabular fracture is a safe and acceptable method of managing displaced acetabular fractures.

Detection of HSP 72 synthesis after acoustic overstimulation in rat cochlea

The purpose of this study was to determine if high intensity acoustic stimulation would induce HSP 72 in rat cochlea. The animals were exposed to 110 dB SPL broad band noise for 1.5 h and sacrificed 4, 6 and 8 h after stimulation. Immunocytochemistry and western blotting were used to detect the expression of HSP 72 in the cochlear tissues. Western blots showed an intense 72 kD band in the noise exposed animals compared to a very light band in non-stimulated control animals. Immunocytochemical results in the cochlea revealed noise induced HSP 72 immunoreactive staining of outer hair cells. Only a few immunoreactive stained inner hair cells were seen and spiral ganglion cells were not stained. These results indicate that acoustic overstimulation can induce the expression of HSP 72 in outer hair cells of the rat cochlea. HSP 72 may serve as a marker for cellular stress and potential damage and may be involved in protection from insult.

Alpha 2-chimerin, an SH2-containing GTPase-activating protein for the ras-related protein p21rac derived by alternate splicing of the human n-chimerin gene, is selectively expressed in brain regions and testes

n-Chimerin (alpha 1-chimerin) is a brain GTPase-activating protein (GAP) for the ras-related p21rac. We now report the occurrence of another form of chimerin, termed alpha 2-chimerin. This is the product of an alternately spliced transcript of the human n-chimerin gene encoding an N-terminal SH2 (src homology 2) domain in addition to the phorbol ester receptor and GAP domains. alpha 1- and alpha 2-chimerin mRNAs were expressed differently. In the rat brain, only alpha 1-chimerin mRNA was expressed in cerebellar Purkinje cells, although both alpha 1- and alpha 2-chimerin mRNAs occurred in neurons in the cerebral cortex, hippocampus, and thalamus. Only alpha 2-chimerin RNA was expressed in rat testes, in early pachytene spermatocytes. A 45-kDa SH2-containing chimerin corresponding to the alpha 2 form was purified from rat brain. As with Escherichia coli 45-kDa recombinant alpha 2-chimerin, purified brain alpha 2-chimerin exhibited racGAP activity which was stimulated by phosphatidylserine. The recombinant SH2 domain bound several 32P-labelled phosphoproteins of PC12 cells, whose phosphorylation increased in response to trophic factors, including nerve growth factor. To examine the relationships of alpha 1- and alpha 2-chimerin transcripts, human genomic DNA clones were characterized. In alpha 2-chimerin mRNA, a 3' splice acceptor site within exon 1 of alpha 1-chimerin mRNA was used, replacing its 5' untranslated region and N-terminal coding sequence. The single human n-chimerin gene was mapped to chromosome 2q31-q32.1, colocalizing with the CRE-BP1 transcription factor gene (2q32). It contained several splice junctions conserved with the sequence-related protein kinase C and bcr genes. alpha 2-Chimerin is only the second SH2-containing GAP and the first example of an SH2 domain generated by alternate splicing.

The CDC42 homologue from Caenorhabditis elegans. Complementation of yeast mutation

A Caenorhabditis elegans cDNA encoding a homologue of the p21 ras-related CDC42, designated as CDC42Ce, was isolated from a nematode mixed stage cDNA library. The encoded protein of 188 amino acid residues has 85% identity to both human G25K and CDC42Hs and 79 and 76% identity to the yeast CDC42Sp and CDC42Sc proteins, respectively. The CDC42Ce cDNA maps to a position on C. elegans chromosome II in close proximity to lin-26, a cell lineage gene. The CDC42Ce cDNA hybridizes to 2- and 1.5-kilobase mRNAs. Their expression is developmentally regulated with highest levels at the embryonic stage, decreasing progressively during development except for an increase of the more abundant 1.5-kilobase mRNA at the L3 stage. The glutathione S-transferase/CDC42Ce fusion protein expressed in Escherichia coli displays both GTP binding and intrinsic GTPase activities. The GTPase activity of CDC42Ce is moderately stimulated by human n-chimaerin, a GTPase-activating protein for the related p21 rac1. The CDC42Ce protein complements the temperature-sensitive lethal mutation cdc42-1 in yeast Saccharomyces cerevisiae. These data suggest that CDC42Ce is the C. elegans homologue of the yeast CDC42. The developmental expression pattern of mRNA and is biochemical properties of its encoded protein which are closely related to CErac1 suggest that the two p21s might be involved in related biological processes.

A new member of the ras superfamily, the rac1 homologue from Caenorhabditis elegans. Cloning and sequence analysis of cDNA, pattern of developmental expression, and biochemical characterization of the protein

A new member of the ras superfamily, designated CErac1 has been identified. The CErac1 cDNA clone was isolated from a Caenorhabditis elegans mixed stage library and encodes a protein of 191 amino acids with 82 and 79% identity to human rac1 and rac2 proteins, respectively. The CErac1 cDNA maps to a position on C. elegans chromosome IV in close proximity to cha-1, a choline acetyltransferase gene. The CErac1 cDNA hybridizes to two mRNAs (1.7 and 0.9 kilobases). Their expression is developmentally regulated, that of the more abundant 1.7 kilobases being highest at the embryonic stage and decreasing dramatically during development with 10% of the embryonic level in adult nematodes. The glutathione-S-transferase/CErac1 fusion protein expressed in Escherichia coli binds GTP and exhibits intrinsic GTPase activity. The GTPase activity of the CErac1 protein is stimulated by human n-chimaerin, a GTPase-activating protein for p21 rac1. These data suggest a role of CErac1 in C. elegans early development. The conserved biochemical properties indicate that further characterization of CErac1 by genetic analysis will be helpful in elucidating not only its role in the signal transduction, but also the biological function of its mammalian homologues.

Developmental regulation and neuronal expression of the mRNA of rat n-chimaerin, a p21rac GAP:cDNA sequence

Human n-chimaerin is a GTPase-activating protein (GAP) for p21rac and a phorbol ester receptor. We have isolated rat n-chimaerin cDNA and investigated the cellular and developmental pattern of mRNA expression in the brain. There is extensive sequence conservation with human n-chimaerin in the coding region and the first 400 nucleotides of the 3'-untranslated region (UTR) (90% and 83% identity respectively). The rat cDNA encodes an additional 35 N-terminal amino acids compared with the reported human cDNA, which has a 5'-UTR sequence inversion and a 41-nucleotide deletion including the putative initiator methionine. The rat cDNA encodes a 334-amino acid protein (38200 M(r), pI 8.04) with 97% amino acid sequence identity with the human protein, after correction of the human 5'-DNA sequence. n-Chimaerin mRNA was detectable in embryonic rat brain at day 15 and increased in amount postnatally from birth to 20 days, coincident with cellular differentiation and synaptogenesis. n-Chimaerin mRNA is restricted to neurons, with highest concentrations in hippocampal pyramidal cells, granule cells of the dentate gyrus and cortical neurons. In the cerebellum the mRNA was detected only in Purkinje neurons. The pattern and specificity of mRNA expression suggests an important role for n-chimaerin in neuronal signal-transduction mechanisms.