Frailty phenotype as mediator between systemic inflammation and osteoporosis and fracture risks: A prospective study

BACKGROUND

Systemic inflammation and frailty have been implicated in osteoporosis (OP) and fracture risks; however, existing evidence remains limited and inconclusive. This study aimed to assess the associations of systemic inflammation and frailty phenotype with incident OP and fracture and to evaluate the mediating role of frailty phenotype.

METHODS

The present study analysed data from the UK Biobank, a comprehensive and representative dataset encompassing over 500 000 individuals from the general population. Baseline peripheral blood cell counts were employed to calculate the systemic inflammation markers, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and systemic immune-inflammation index (SII). Frailty phenotype was assessed using five criteria, defined as frail (≥3 items met), pre-frail (1-2 items met) and non-frail (0 items met). OP and fracture events were confirmed through participants' health-related records. Multivariable linear and Cox regression models were utilized, along with mediation analysis.

RESULTS

Increased systemic inflammation was associated with increased risks of OP and fracture. The corresponding hazard ratios and 95% confidence intervals (CIs) for OP risk per standard deviation increase in the log-transformed NLR, PLR and SII were 1.113 (1.093-1.132), 1.098 (1.079-1.118) and 1.092 (1.073-1.111), and for fracture risk, they were 1.066 (1.051-1.082), 1.059 (1.044-1.075) and 1.073 (1.058-1.089), respectively. Compared with the non-frail individuals, the pre-frail and frail ones showed an elevated OP risk by 21.2% (95% CI: 16.5-26.2%) and 111.0% (95% CI: 98.1-124.8%), respectively, and an elevated fracture risk by 6.1% (95% CI: 2.8-9.5%) and 38.2% (95% CI: 30.7-46.2%), respectively. The systemic inflammation level demonstrated a positive association with frailty, with β (95% CI) of 0.034 (0.031-0.037), 0.026 (0.023-0.029) and 0.008 (0.005-0.011) in response to per standard deviation increment in log-transformed SII, NLR and PLR, respectively. The frailty phenotype mediated the association between systemic inflammation and OP/fracture risk. Subgroup and sensitivity analyses confirmed the robustness of these findings.

CONCLUSIONS

Systemic inflammation and frailty phenotype are independently linked to increased risks of OP and fracture. The frailty phenotype partially mediates the association between systemic inflammation and osteoporotic traits. These results highlight the significance of interventions targeting systemic inflammation and frailty in OP and fracture prevention and management.

Early-life tobacco smoke elevating later-life osteoporosis risk: Mediated by telomere length and interplayed with genetic predisposition

INTRODUCTION

The growing prevalence of osteoporosis (OP) in an aging global population presents a significant public health concern. Tobacco smoke negatively affects bone turnover, leading to reduced bone mass and heightened OP and fracture risk. However, the impact of early-life tobacco smoke exposure on later-life OP risk remains unclear.

OBJECTIVES

This study was to explore the effects of early-life tobacco smoke exposure on incident OP risk in later life. The mediating role of telomere length (TL) and the interaction with genetic predisposition were also studied.

METHODS

Data on in utero tobacco smoke exposure (IUTSE) status and age of tobacco use initiation from the UK Biobank were used to estimate early-life tobacco smoke exposure. Incident OP cases were identified according to health-related records. Linear, Cox, and Laplace regression models were mainly used for data analysis.

RESULTS

Individuals with IUTSE showed a higher OP risk [hazard ratio (HR): 1.06, 95 % confidence interval (CI): 1.01, 1.11] and experienced earlier OP onset by 0.30 years [50th percentile difference = -0.30, 95 % CI: -0.51, -0.09] compared to those without. Participants initiating tobacco smoke in childhood, adolescence, and adulthood had 1.41 times (95 % CI: 1.23, 1.61), 1.17 times (95 % CI:1.10, 1.24), and 1.14 times (95 % CI: 1.07, 1.20) the risk of OP, respectively, compared to never smokers. They also experienced earlier OP onset by 2.16, 0.95, and 0.71 years, sequentially. The TL significantly mediated the early-life tobacco exposure and OP association. Significant joint and interactive effects were detected between early-life tobacco smoke exposure and genetic elements.

CONCLUSIONS

Our findings implicate that early-life tobacco smoke exposure elevates the later-life OP risk, mediated by telomere length and interplayed with genetic predisposition. These findings highlight the importance of early-life intervention against tobacco smoke exposure and ageing status for precise OP prevention, especially in individuals with a high genetic risk.

Mediating role of host metabolites in strontium's effect on osteoporosis among older individuals: Findings from Wuhan, China

Strontium is receiving widespread attention due to its remarkable biological qualities in preventing bone resorption and fostering osteogenesis. However, the chemical processes behind strontium's dual activities on bone cells are not yet fully understood. This study used the metabolomic technique to identify and examine potential biomarkers between strontium exposure and osteoporosis (OP) risk. A total of 806 participants were recruited for the detection of plasma strontium content via inductively coupled plasma-mass spectrometry. Plasma metabolites were profiled in 254 participants through an untargeted metabolomics technique. Generalized linear models were primarily used to analyze associations among plasma strontium, metabolites, and OP. The mediating effects of metabolites on the strontium-OP association were further investigated. A total of 31 differential metabolites were observed, 10 of which were upregulated and 21 were downregulated in the OP group compared with the non-OP group. Five metabolites (3-phenoxybenzoic acid, Cer (t18:0/16:1), HexCer(t16:1/12:1(2OH)), HexCer(t14:2/18:1(2OH)), and TG(16:0-18:1-24:4)) were selected as potential mediators based on their significant association with OP risk and with femoral neck and lumbar spine bone mineral density (BMD). Moreover, all except TG(16:0-18:1-24:4) were involved in the OP discrimination model with excellent power combined with several traditional variables. 3-Phenoxybenzoic acid and Cer(t18:0/16:1) had significant indirect effects on the strontium-OP association. The five candidate metabolites mediated 83.79 % of the strontium-OP association. Plasma strontium level was associated with reduced OP risk in the Han population in Wuhan. Thus, plasma metabolite profiling revealed five BMD/OP-associated metabolites that acted as mediators in the strontium-OP association. Our findings provided evidence of the mediating role of host plasma metabolites in strontium's effect on OP pathology.

Role of lifestyle factors in mediating the effect of educational attainment on bone mineral density: a Mendelian randomization study

We performed two-step multivariable Mendelian randomization analysis to explore the mediating role of lifestyle factors in educational attainment (EA) and bone mineral density (BMD). Summary statistics from genome-wide association studies of European lineages were used. Coffee intake and processed-meat intake mediated the association between EA and BMD.

PURPOSE

This study aimed to explore the causal relationship between educational attainment (EA) and bone mineral density (BMD), as well as the potential mediating roles of lifestyle factors in the expected EA-BMD relationship. By identifying modifiable lifestyle factors, we hope to provide relevant information to prevent osteoporosis or low BMD in the less educated population.

METHODS

Using summary statistics from genome-wide association studies (GWAS) of major European lineages, one- and two-sample Mendelian randomization (MR) analyses were performed to estimate the association between EA (in the social sciences genetic association consortium (SSGAC) involving 766,345 individuals and in the UK Biobank (UKB) involving 293,723 individuals) and BMD (in the Genetic Factors for Osteoporosis Consortium involving 426,824 individuals selected from the UKB). The EA variable in both consortia were expressed by years of schooling completed. Two-step multivariable MR was used to assess the mediating roles of eight lifestyle-related factors (moderate-to-vigorous physical activity, watching television, computer using, smoking initiation, coffee intake, alcohol intake frequency, tea intake, and processed-meat intake) in the EA and BMD association, and the corresponding mediating proportion was calculated. Meta-analysis was used to present a pooled estimate.

RESULTS

A total of 317 and 73 independent single-nucleotide polymorphisms (SNPs) of GWAS significance (P < 5.0 × 10-8) were selected as instrumental variables (IVs) for EA in the SSGAC and UKB, respectively. A total of 513 SNPs were selected as IVs for the BMD. The results of one- and two-sample MR revealed that the genetically predicted BMD increased by 0.094 and 0.047 g/cm2, respectively, in response to each SD increment of genetically predicted schooling years. Among the eight candidate mediators, coffee intake and processed-meat intake were potential mediators revealed by the two-step multivariable MR analysis, mediating 26.87% and 23.92% of EA's effect on BMD, respectively. Meta-analysis showed consistent findings. Results of sensitivity analysis indicated the robustness of our findings.

CONCLUSION

We elucidated the causal protective effect of EA on BMD and the mediating roles of coffee intake and processed-meat intake. Intervening with these factors can potentially reduce the burden of bone density loss or osteoporotic fractures among the less educated population.

Metal mixture and osteoporosis risk: Insights from plasma metabolite profiling

The pathophysiology of osteoporosis (OP) is influenced by exposure to nonessential harmful metals and insufficient or excessive intake of necessary metals. Investigating multiple plasma metals, metabolites, and OP risk among older adults may reveal novel clues of underlying mechanisms for metal toxicity on bone mass. A total of 294 adults ≥ 55 years from Wuhan communities were included. Plasma concentrations of 23 metals and metabolites were measured via inductively coupled plasma-mass spectrometry and global metabolite detection. To investigate the relationships between plasma metals, OP risk, and OP-related metabolites, three different statistical techniques were used: generalized linear regression model, two-way orthogonal partial least-squares analysis (O2PLS), and weighted quantile sum (WQS). The mean ages were 66.82 and 66.21 years in OP (n = 115) and non-OP (n = 179) groups, respectively. Of all 2999 metabolites detected, 111 differential between-group members were observed. The OP risk decreased by 58.5% (OR=0.415, 95% CI: 0.237, 0.727) per quartile increment in the WQS index indicative of metal mixture exposure. Consistency remained for bone mineral density (BMD) measurements. The O2PLS model identified the top five OP-related metabolites, namely, DG(18:2_22:6), 3-phenoxybenzoic acid, TG(16:1_16:1_22:6), TG(16:0_16:0_20:4), and TG(14:1_18:2_18:3), contributing most to the joint covariation between the metal mixture and metabolites. Significant correlations between each of them and the metal mixture were found using WQS regression. Furthermore, the five metabolites mediated the associations of the metal mixtures, BMD, and OP risk. Our findings shed additional light on the mediation functions of plasma metabolites in the connection between multiple metal co-exposure and OP pathogenesis and offer new insights into the probable mechanisms underpinning the bone effects of the metal mixture.

Highly Variable Expression of ESR1 Splice Variants in Human Liver: Implication in the Liver Gene Expression Regulation and Inter-Person Variability in Drug Metabolism and Liver Related Diseases

Estrogen receptor alpha (ESR1) plays an important role in many tissues including the liver. Numerous alternative splice variants of ESR1 exist that encode ESR1 proteins with varying functions. We aim to study ESR1 genomic organization and its mRNA expression profile in human liver by incorporating information from literature and genomic databases (Ensembl, NCBI and GTEx), and employing a quantitative method to measure all known ESR1 mRNA splice variants in 36 human livers. We re-constructed ESR1 genomic organization map that contains 29 exons. ESR1 mRNA splice variants with varying 5' untranslated region (5'UTR) and/or missing each of eight coding exons are readily detectable in liver and other tissues. Moreover, we found extensive inter-individual variability in splice variant pattern of ESR1 transcripts. Specifically, ESR1 transcripts lacking first coding exon are the main transcripts in liver, which encode ESR1 proteins missing N-terminal 173 amino acids (for example, ERα46), reported previously to have either constitutive activity or dominant negative effects depending on cellular context. Moreover, some livers predominantly express ESR1 transcripts missing exon 10 or 16, encoding C-terminal truncated ESR1 proteins with varying ESR1 activities. Inter-person variability in ESR1 expression profile may contribute to inter-person variability in drug metabolism and susceptibility to liver related diseases.

Does having a rotator cuff repair prior to reverse total shoulder arthroplasty influence the outcome?

Aims

The number of rotator cuff repairs that are undertaken is increasing. Reverse shoulder arthroplasty (RSA) is the procedure of choice for patients with rotator cuff arthropathy. We sought to determine whether patients who underwent rotator cuff repair and subsequent RSA had different outcomes compared with a matched control group who underwent RSA without a previous rotator cuff repair.

Patients and Methods

All patients with a history of rotator cuff repair who underwent RSA between 2000 and 2015 with a minimum follow-up of two years were eligible for inclusion as the study group. Outcomes, including the American Shoulder and Elbow Surgeons (ASES) scores, were compared with a matched control group of patients who underwent RSA without having previously undergone rotator cuff repair.

Results

The study group included 45 patients. Their mean age was 69 years (sd 8.6) and 27 patients (60%) were women. The mean ASES score improved from 43.1 to 76.6 two years postoperatively, and to 66.9 five years postoperatively. There was no significant difference between the outcomes at two years in the two groups (all p ≥ 0.05), although there was significantly more improvement in ASES scores in the control group (44.5 vs 33.4; p = 0.01). However, there was no significant difference between ASES scores at two and five years when baseline ASES scores were matched in the two groups (p = 0.42 at two years; p = 0.35 at five years).

Conclusion

Significant improvements in ASES scores were seen following RSA in patients who had previously undergone rotator cuff repair. They had higher baseline ASES scores than those who had not previously undergone this surgery. However, there was no significant difference in outcomes between the two groups, two years postoperatively. Previous rotator cuff repair does not appear to affect the early outcome after RSA adversely.

Carbon-13 urea breath test for Helicobacter pylori infection in patients with uninvestigated ulcer-like dyspepsia: an evidence-based analysis

BACKGROUND

Dyspepsia is a condition defined by chronic pain or discomfort in the upper gastrointestinal tract that can be caused by Helicobacter pylori. The carbon-13 urea breath test (¹³C UBT) is a non-invasive test to detect H. pylori.

OBJECTIVES

We aimed to determine the diagnostic accuracy and clinical utility of the ¹³C UBT in adult patients with ulcer-like dyspepsia who have no alarm features.

DATA SOURCES

A literature search was performed using Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid Embase, the Wiley Cochrane Library, and the Centre for Reviews and Dissemination database, for studies published between 2003 and 2012.

REVIEW METHODS

We abstracted the sensitivity and specificity, which were calculated against a composite reference standard. Summary estimates were obtained using bivariate random effects regression analysis.

RESULTS

From 19 diagnostic studies, the ¹³C UBT summary estimates were 98.1% (95% confidence interval [CI], 96.3-99.0) for sensitivity and 95.1% (95% CI, 90.3-97.6) for specificity. In 6 studies that compared the ¹³C UBT with serology, the 1¹³C UBT sensitivity was 95.0% (95% CI, 90.1-97.5) and specificity was 91.6 % (95% CI, 81.3-96.4). The sensitivity and specificity for serology were 92.9% (95% CI, 82.6-97.3) and 71.1% (95% CI, 63.8-77.5), respectively. In 1 RCT, symptom resolution, medication use, and physician visits were similar among the ¹³C UBT, serology, gastroscopy, or empirical treatment arms. However, patients tested with ¹³C UBT reported higher dyspepsia-specific quality of life scores.

LIMITATIONS

Processing of the ¹³C UBT results can vary according to many factors. Further, the studies showed significant heterogeneity and used different composite reference standards.

CONCLUSIONS

The ¹³C UBT is an accurate test with high sensitivity and specificity. Compared with serology, it has higher specificity. There is a paucity of data on the ¹³C UBT beyond test accuracy.

PLAIN LANGUAGE SUMMARY

Breath test for detecting bacteria in patients with ulcer-like symptoms. Dyspepsia is a condition that causes long-term pain or discomfort in the upper abdomen. Symptoms can include heartburn, burping, bloating, nausea, or slow digestion. Dyspepsia can be caused by a bacterium that also causes ulcers and stomach cancer. Half of the world's people are believed to be infected with these bacteria. A test has been developed to detect the bacteria in a breath sample. Our review determined the accuracy of this breath test in adults with ulcer-like symptoms. From 19 studies, the breath test correctly identified 98% of patients with the bacteria and 95% of patients without the bacteria, as determined by a reference standard. Six studies compared the breath test to a blood test that is currently used. Both the breath and blood tests performed well in correctly identifying patients with the bacteria. However, the blood test was incorrectly positive in 20 more patients who did not have the bacteria according to the breath test. This means that more patients would have received unnecessary treatment. Thus, the breath test is an accurate test to detect the bacteria in adult patients who have ulcer-like symptoms. But the many differences among the studies in our review included several steps taken to perform the breath test and the reference standards used to compare a blood test with the breath test.

Methodological and reporting quality of systematic reviews on tuberculosis

BACKGROUND

Systematic reviews are used to inform tuberculosis (TB) guidelines. However, there are no data on whether TB systematic reviews are conducted well and reported transparently.

METHODS

We searched four databases for reviews published between 2005 and 2010. Methodological quality was evaluated using AMSTAR and quality of reporting was assessed using PRISMA.

RESULTS

Of 152 articles, 137 (90%) met the inclusion criteria. Only 3 of 11 AMSTAR quality items were met in most reviews: appropriate methods to combine findings (67%), comprehensive literature search (72%) and presentation of characteristics of included studies (90%). The other eight items were met in 4-53% of the reviews. Only 4% of the reviews disclosed conflicts of interest. The majority of the PRISMA items were reported in more than 60-76% of the reviews. Only nine items were reported in less than 55% of the reviews, the lowest being the full-search strategy (30%), risk of bias across studies in the Methods (27%) and Results (21%) sections, and indication of a review protocol (15%).

CONCLUSIONS

Systematic reviews in our survey were well reported but generally of moderate to low quality. Better training, use of reporting guidelines and registration of systematic reviews could improve the quality of TB reviews.

Simulation of Core Deflection in Powder Injection Molding

Core deflection in powder injection molding is one of the main causes of the structural defects in the molded part. Simulation of the core deflection in the injection molding process requires solution of the fluid-solid interaction problem, in which the fluid flow and solid deformation problems are coupled along the fluid-solid interface. A three-dimensional finite element program was developed in this work for a non-isothermal injection molding simulation including the fluid-solid interaction effects. With the assumption of small deformation in the solid structure, the fluid flow problem is formulated in an Eulerian frame-work, whereas the solid structure problem is formulated in a Lagrangian framework. Numerical simulation of the filling stage of injection molding for an airfoil-shaped part is presented and compared with the experimental data. The predicted melt-front advancement as well as the pressure is in good agreement with the corresponding experimental results. The predicted core deflection during the filling stage of the injection molding process is also compared with the measurements on a molded part.

High prevalence of smoking among patients with suspected tuberculosis in South Africa

There is growing evidence that tobacco smoking is an important risk factor for tuberculosis (TB). There are no data validating the accuracy of self-reported smoking in TB patients and limited data about the prevalence of smoking in TB patients from high-burden settings. We performed a cross-sectional analysis of 500 patients with suspected TB in Cape Town, South Africa. All underwent comprehensive diagnostic testing. The accuracy of their self-reported smoking status was determined against serum cotinine levels. Of the 424 patients included in the study, 56 and 60% of those with active and latent TB infection (LTBI), respectively, were current smokers. Using plasma cotinine as a reference standard, the sensitivity of self-reported smoking was 89%. No statistically significant association could be found between smoking and active TB or LTBI. In Cape Town, the prevalence of smoking among patients with suspected and confirmed TB was much higher than in the general South African population. Self-reporting is an accurate measure of smoking status. These results suggest the need to actively incorporate tobacco cessation programmes into TB services in South Africa.

Tuberculosis in children: New diagnostic blood tests

The interferon-gamma-release assays were developed to overcome the pitfalls and logistic difficulties of the tuberculin skin test (TST) for the diagnosis of latent tuberculosis infection (LTBI). These blood tests measure the in vitro production of interferon-gamma by sensitized lymphocytes in response to Mycobacterium tuberculosis-specific antigens. Two interferon-gamma-release assays are registered for use in Canada: the QuantiFERON-TB Gold In-Tube assay (Cellestis Inc, Australia) and the T.SPOT-TB test (Oxford Immunotec, United Kingdom). Evaluation of these tests has been hampered by the lack of a gold standard for LTBI, and limited paediatric data on their use. It appears that they are more specific than the TST, and may be useful for evaluating TST-positive patients at low risk of true LTBI. Moreover, they may add sensitivity if used in addition to the TST in immunocompromised patients, very young children and close contacts of infectious adults. A summary of these tests, their limitations and their application to clinical paediatric practice are described.

Teaching a complex verbal response to a hearing-impaired girl

A 3-yr-old hearing-impaired girl, who used neither the article "the" nor the auxiliary verb "is" was taught to use these words in describing a picture, initially through imitation and then in response to the command, "Tell me about this". As a result, she was able to use sentences in the present progressive form to describe a number of pictures on which she had received no training. This newly acquired behavior was subsequently extinguished and then reinstated.

Tuberculosis in children: New diagnostic blood tests

The interferon-gamma-release assays were developed to overcome the pitfalls and logistic difficulties of the tuberculin skin test (TST) for the diagnosis of latent tuberculosis infection (LTBI). These blood tests measure the in vitro production of interferon-gamma by sensitized lymphocytes in response to Mycobacterium tuberculosis-specific antigens. Two interferon-gamma-release assays are registered for use in Canada: the QuantiFERON-TB Gold In-Tube assay (Cellestis Inc, Australia) and the T.SPOT-TB test (Oxford Immunotec, United Kingdom). Evaluation of these tests has been hampered by the lack of a gold standard for LTBI, and limited paediatric data on their use. It appears that they are more specific than the TST, and may be useful for evaluating TST-positive patients at low risk of true LTBI. Moreover, they may add sensitivity if used in addition to the TST in immunocompromised patients, very young children and close contacts of infectious adults. A summary of these tests, their limitations and their application to clinical paediatric practice are described.

Full scale implementation of the nutrient limited BAS process at Södra Cell Värö

A combination of the suspended carrier biofilm process and the activated sludge process (biofilm-activated sludge--BAS) has been shown to be very successful for the treatment of different types of pulp and paper mill effluents. The robust biofilm pre-treatment in combination with activated sludge results in a stable, compact and highly efficient process. Recent findings have shown that nutrient limited operation of the biofilm process greatly improves the sludge characteristics in the following activated sludge stage, while minimising sludge production and effluent discharge of nutrients. The nutrient limited BAS process was implemented at full scale at the Södra Cell Värö kraft mill and taken into operation in July 2002. After start-up and optimisation over about 5 months, the process meets all effluent discharge limits. The removal of COD is close to 70% and the removal of EDTA greater than 90%. Typical effluent concentrations of suspended solids and nutrients during stable operations have been 20-30 mg/L TSS, 0.3-0.5 mg/L phosphorus and 3-5 mg/L nitrogen. The sludge production was 0.09 kgSS/kg COD removed and the sludge volume index was 50-100 mL/g.

Healthcare expenditure in patients treated with venlafaxine or selective serotonin reuptake inhibitors for depression and anxiety

We compared healthcare expenditure over a six-month period following initiation of therapy with either venlafaxine (immediate and extended-release) or a selective serotonin reuptake inhibitor (SSRI) in depressed patients with or without anxiety. Patients beginning treatment for a new depressive episode were identified retrospectively using the administrative data of the MEDSTAT MarketScan database for the period 1994-1999. Before beginning therapy, patients prescribed venlafaxine had more non-mental illnesses (0.85 vs 0.76; p<0.01) and hospitalisations for mental illness (0.53 vs 0.29; p<0.05) than patients prescribed SSRIs. In the six months after initiating treatment, venlafaxine was associated with lower hospitalisation expenditure for non-mental illness ($177 vs $526; p<0.01) than SSRIs, although total healthcare expenditure was not significantly different. Venlafaxine was associated with a 50% decrease in the odds of hospitalisation for non-mental illness compared with SSRIs, with significantly lower inpatient expenditure.

The preparation and characterization of an immobilized l-glutamic decarboxylase and its application for determination of l-glutamic acid

This paper is to study the preparation and characterization of an immobilized L-glutamic decarboxylase (GDC) and develop a sensitive method for the determination of L-glutamate using a new biosensor, which consists of an enzyme column reactor of GDC immobilized on a novel ion exchange resin (carboxymethyl-copolymer of allyl dextran and N.N'-methylene-bisacrylamide CM-CADB) and ion analyzer coupled with a CO(2) electrode. The conditions for the enzyme immobilization were optimized by the parameters: buffer composition and concentration, adsorption equilibration time, amount of enzyme, temperature, ionic strength and pH. The dynamic response of Na(2)HPO(4)-citric acid buffer system selected is much better than that of the others, 0.10 M HAc-0.10 M NaAc and 0.10 M sodium citrate-0.10 M citric acid. The initial rate of the enzyme reaction v(0) in this buffer system is 1.76 mol. l(-1) min(-1), moreover, the rate of the enzyme reaction appears linear in the first 4 min. The optimum adsorption equilibrium time is around 6 h. The amount of enzyme adsorbed on CM-CADB resin affects the response to substrate L-glutamic acid, the widest range of linearity is obtained with over 30 mg (GDC)/g(resin). The GDC activity immobilized on CM-CADB reaches a maximum when the immobilization temperature was kept around 40 degrees C. pH was kept at 4.4 when measuring the activity of the immobilized GDC. No variation of the activity of immobilized GDC is observed when the capacity is over 2.5 meq/g.(CM-CADB resin). The properties of the immobilized enzyme on CM-CADB were characterized. No significant improvement can be achieved when the substrate concentration exceeds 12.00 mmol/l, where the activity of immobilized GDC is equal to 1.58 mmol/l.min.g. The optimum pH is found to be 5.2, which changes 0.2 unit, comparing with that of the free GDC (5.0). The optimum temperature is found to be around 48 degrees C, which is lower than that of free GDC (55 degrees C). The critical temperature of the free GDC and the immobilized GDC is approximately 50 degrees C and 45 degrees C, respectively. The half-life of the activity is 127 days when the immobilized enzyme was stored in the cold (4 degrees C). An immobilized GDC enzyme column reactor matched with a flow injection system-ion analyzer coupled with CO(2) electrode-data collection system made up the original form of the apparatus of biosensor for determining of L-glutamic acid. The determination conditions are that the buffer solution is 0.10 M Na(2)HPO(4)-0.05 M citric acid at pH 4.4 and t = 37 degrees C. The limit of detection is 1.0 x 10(-)(5) M. The linearity response is in the range of 5 x 10 (-2) - 5 x 10 (-5) M. The equation of linear regression of the calibration curve is y = 43.3x + 181.6 (y is the milli-volt of electrical potential response, x is the logarithm of the concentration of the substrate of L-glutamic acid). The correlation coefficient equals 0.99. The coefficient of variation equals 2.7%.

Bifidobacterium thermacidophilum sp. nov., isolated from an anaerobic digester

A new phenotypic group of Bifidobacterium strains, isolated from an anaerobic digester for the treatment of waste water from a bean-curd farm, was described previously. In this study, the DNA-DNA relatedness between strain 36 (type strain, AS 1.2282T) of this new group and the type strains of other described Bifidobacterium species was analysed. The low level of DNA homology (0-58.9%) as well as comparison of the 16S rDNA sequences confirmed the distinct phylogenetic position of strain 36. In addition, the new species differed from other Bifidobacterium species in its phenotypic characteristics, such as its growth at moderately thermophilic conditions (49.5 degrees C) and at relatively low pH (4.0), as well as its sugar-fermentation pattern. On the basis of phenotypic, genetic and phylogenetic studies, a new Bifidobacterium species, Bifidobacterium thermacidophilum sp. nov., was designated.

[Some basic techniques of virtual reality body healthiness vehicles for rehabilitation]

Some know-how techniques of virtual reality rehabilitation vehicles are discussed in this paper after a brief introduction of the application background and the structure and functions of the vehicles. This kind of vehicles can be used for psychological treatment during rehabilitation. Pateints can select different modes of physical exercises according to their individual situations, and therefore they can get rehabilitation much faster and more easily than those under the traditional treatments.

[The prospects of research on VR rehabilitation engineering]

In this paper, we present the recent development of Vitual Reality (VR) technology and rehabilitation engineering and discuss the rationality and feasibility of the application of VR to rehabilitation. With VR technology, psychological induction can be better introduced in rehabilitating exercises and patients can be tremendously released from fret during traditional physical training for rehabilitation. The VR is expected to bring about a technological revolution in rehabilitation engineering.

[An investigation of precipitation of airborne fungi particles in the rooms of university library]

Precipitation of airborne fungi particles in the rooms of an University library and the influencing factors were studied in May 1994 with the fallen plate method. The total average precipitation of airborne fungi particles was 11.68 per dish in 5 minutes. The differences were significant from different room patterns, floors and times, so were the humidity assayed. The book-store rooms and reading rooms had an average precipitation of 15.01 and 8.35 per dish in 5 minutes respectively (P < 0.05), and humidity of 41.7 and 11.4 percent respectively (P < 0.01). The influencing factors were: different floors and room patterns, the people's activity, the different time, humidity, ventilation and book pollution.

[Numerical taxonomy of bifidobacteria and homology analysis of some representative strains]

Fifty five strains of bifidobacteria belonging to Bifidobacterium from various sources were studied by using numerical taxonomic techniques. These organisms included 13 reference strains and 42 newly isolated strains (19 strains of human sources, 25 strains of animal sources and 11 strains obtained from sewage). Several strains isolated from the animals weren't isolated before. Overall similarities of the strains for 75 characters contained morphological, physiological and biochemical characteristics and antibacterial susceptibility were determined. Dendrogram of numerical analysis based on unweighted pair cluster average linkage were achieved. Five clusters were defined at 70% Sm level. The relationships of these strains among five clusters were analysed. The strains of human sources were basically separated from the animal strains, and the sewage strains were distributed between the animal clusters and the human clusters. On the basis of the numerical analysis, the G + C content of DNA of some representative strains among these clusters were measured. Biotin-labeled DNA segments, complementary to variable regions of 16S rRNA, were amplified using PCR as probes. In the dot-blot hybridization the relationships of DNA segments among some strains were discussed. The test results showed that the homologies among the strains in same species and various species were different. The studies are valuable for further research in the relationships of some species among bifidobacteria of various sources.

[Effect of lidocaine on cardiovascular response to stomach tube intubation before surgery]

The purpose of this study was to observe the effect of lidocaine on cardiovascular responses to stomach-tube intubation. 80 patients (ASA I-II) were randomly divided into two groups: study group with 2% lidocaine 5 ml throat surface anesthesia (n = 40) and control group without lidocaine (n = 40). Hemodynamic variables including systolic blood pressure (SBp), heart rate (HR), and rate-pressure product (RPP) were measured before, immediately, 1 min, 3 min, ore stable than that in control group (P < 0.05 or P < 0.01).

CONCLUSION

2% lidocaine can effectively prevent cardiovascular responses to the intubation.

[P53 expression and clinical significance in oral squamous cell carcinoma]

P53 protein expression was investigated in oral squamous cell carcinomas and oral premalignant lesions by monoclonal antibody Do-1 and immunohistochemistry technique. 4 of 12 (33.3%) samples of severe epithelial dysplasia and 25 of 44 (56.8%) samples of squamous cell carcinoma expressed P53 protein while all the normal mucosa, mild and moderate epithelial dysplasia were negative. The P53 expression in carcinomas was associated with differentiation, lymph node metastasis and tumour stage. This result indicated that P53 genic mutation might be an early event in oral mucosa carcinogenesis and related to oral tumor progression. Detection of P53 protein probably has clinical significance in identifying the premalignant lesions of oral mucosa and predicting the prognosis of oral carcinomas.

Tracheoesophageal fistula in a patient with recurrent Hodgkin's disease. A case for hope or despair

Tracheoesophageal fistula (TEF) is a devastating complication of malignancies; however, those associated with Hodgkin's disease (HD) may carry a better prognosis. We present a patient with recurrent HD and TEF.

Continuous intravenous infusion of rocuronium (ORG 9426) in patients receiving balanced, enflurane, or isoflurane anesthesia

BACKGROUND

Rocuronium (ORG 9426) is a new nondepolarizing neuromuscular blocking agent with a rapid onset and an intermediate duration of action. This study obtains the infusion requirements of rocuronium in 30 patients in whom anesthesia was maintained with barbiturate-nitrous oxide-opioid, nitrous oxide and enflurane, or nitrous oxide and isoflurane.

METHODS

For all 30 patients, anesthesia was induced with intravenous thiopental and fentanyl, followed by 0.45 mg/kg rocuronium. Patients were randomly allocated to receive either: 1) nitrous oxide in 40% oxygen supplemented with fentanyl, thiopental, and droperidol (balanced anesthesia), 2) 1.25 MAC enflurane-nitrous oxide, or 3) 1.25 MAC isoflurane-nitrous oxide. Once blockade had recovered to 95% depression of twitch height, muscle relaxation was maintained by continuous infusion of rocuronium, adjusted to maintain mechanical twitch response at 95% depression.

RESULTS

At 90 and 120 min, the enflurane and isoflurane groups had lower infusion requirements than those receiving barbiturate-nitrous oxide-opioid anesthesia (P < 0.02), but these did not differ significantly between the two volatile agents. Final infusion requirements (mean +/- SD) were 9.8 +/- 3.7, 5.9 +/- 3.1, and 6.1 +/- 2.7 micrograms.kg-1.min-1 for the groups receiving barbiturate-nitrous oxide-opioid, enflurane, and isoflurane anesthesia, respectively. Spontaneous recovery began soon after termination of the infusion; in all patients, twitch tension equaled 10% of control within 5 min.

CONCLUSIONS

The infusion requirements to maintain 95% twitch depression approximated 10 micrograms.kg-1.min-1 during barbiturate-nitrous oxide-opioid anesthesia. These requirements were reduced by 40% during anesthesia involving enflurane or isoflurane.

Oral cancer progression and c-erbB-2/neu proto-oncogene expression

Monoclonal antibody PAb3 to c-erbB-2/neu protein was utilized in the immunoperoxidase staining of 86 human specimens from oral mucosa. These tissue specimens represented a spectrum from 7 normal to 9 simple hyperplasia, 15 mild dysplasia, 14 moderate dysplasia, 20 severe dysplasia and 21 squamous cell carcinoma. Our study indicated that as the cells acquire a more malignant phenotype, there was a progressive increase in neu expression. It also suggested that neu may be involved in the development of oral cancers and that its evaluation in the early stages may assist in the diagnosis and management of oral cancers.

Perceptual-oral training of two hearing-impaired children in the recognition and production of /s/ and /z/

Two hearing-impaired children were tested and trained in the utilization of an artificial acoustic cue that signalled the presence of /s/ and /z/ in verbal stimuli. These sounds, chosen because they are among the most important morphemes in English, were both perceived and produced significantly better by the subjects following only seven training sessions when the cue, automatically signalled by a specially designed laboratory device, was presented at a 20 dB sensation level in a frequency range immediately above the subjects' upper limits of hearing for amplified speech. The implications of the study are briefly discussed in relation to testing and training procedures involving sensory aids.

[Staging of prostatic carcinoma. Accuracy of magnetic resonance]

Twenty-nine prostatic cancer patients were evaluated for staging purpose by Magnetic Resonance (MR). MR findings were correlated with the pathologic examination in 18/29 patients who underwent radical prostatectomy. Four MR staging parameters were evaluated individually: periprostatic fat; periprostatic venous plexus; seminal vesicles and pelvic adenopathy. MR correctly staged 16/18 patients, with one case of overstaging and one case of understaging. The diagnostic accuracy of MR in differentiating intracapsular stage B from extracapsular stage C was 87%, with a sensitivity of 90% and a specificity of 87%. MR and CT results agreed in 4 of the 7 operated patients who were examined with both techniques; in 3 cases there was disagreement, and MR was correct.

Adrenal gland: MR imaging

The authors investigated the utility of magnetic resonance (MR) imaging in identifying the normal adrenal gland in 100 patients as well as in distinguishing adrenal adenomas (n = 12) from malignant neoplasms (n = 14). The left adrenal gland was seen in 99 of 100 cases and the right in 91 of 100 cases. The adrenals were most easily seen with T1-weighted spin-echo pulse sequences. The ratio of the intensity of the adrenal mass to that of fat at 2,100/90 (repetition time msec/echo time msec) was most helpful in distinguishing adrenal adenomas from malignant neoplasms. In contrast to other studies, the adrenal mass/liver intensity ratios were not helpful. All ten lesions with adrenal mass/fat ratios at 2,100/90 of 0.8 or greater were malignant, whereas all eight adrenal masses with a ratio less than 0.6 were adrenal adenomas. However, eight (31%) of the masses (four adenomas and four malignant neoplasms) had ratios between 0.6 and 0.8. Although MR imaging has considerable potential in characterizing adrenal masses, larger studies are needed to determine its true sensitivity and specificity.

Primary bladder carcinoma: evaluation with MR imaging

Magnetic resonance (MR) imaging was performed in 23 patients (25 tumors) with proved bladder neoplasms. MR studies were retrospectively evaluated and compared with computed tomographic (CT) and pathologic findings. Bladder neoplasms, having a signal intensity intermediate between those of urine and perivesical fat, were best seen on T1-weighted and proton-density images. MR imaging was as accurate as technically well-performed CT studies in detecting extravesical tumor extension. MR could additionally be used to assess the integrity of the bladder wall. On T2-weighted images the normal bladder wall appeared as a thin, linear, low-intensity structure. The disruption of this low-intensity line was indicative of deep muscle invasion, whereas preservation of this low intensity line implied a more localized lesion. Although chemical shift artifacts might cause apparent disruption of the bladder wall, knowledge of this artifact coupled with additional imaging along different planes helps avoid misinterpretation of this artifact as deep muscle invasion.

MR imaging of the scrotum with a high-resolution surface coil

Magnetic resonance (MR) imaging of the scrotum with a high-resolution surface coil was performed in ten healthy volunteers and 20 patients with scrotal abnormalities demonstrated by high-resolution real-time ultrasound (US). Four patients had an abnormal testis (two tumors, one cyst, one testicular atrophy), and 16 patients had extratesticular abnormalities (four hydroceles, five epididymal cysts, one hernia, and six cases of epididymitis). The normal structures of the scrotum were depicted clearly on MR images. In all cases, the tunica albuginea was easily differentiated from the testis and epididymis. MR imaging enabled one to distinguish intratesticular from extratesticular lesions and to determine whether a lesion was solid or cystic. Complicated and simple fluid collections could also be differentiated. In general, MR imaging and US scanning provided similar information. A potential advantage of MR imaging is in the evaluation of patients with painful scrotal lesions that may limit US evaluation.

Diagnosis and staging of renal cell carcinoma: a comparison of MR imaging and CT

MR studies were performed in 36 patients with proven renal cell carcinoma. In 27 patients in whom a radical nephrectomy was performed, MR studies were reviewed and compared with CT and pathologic findings. Renal cell carcinomas had a varied MR signal with the most common appearance being a mass with an intensity intermediate between the renal cortex and the medulla on T1-weighted images and hyperintense on T2-weighted images. MR was similar to CT in staging renal cell carcinomas (74% for MR vs 67% for CT). Neither CT nor MR was reliable in differentiating stage I from stage II lesions. MR clearly showed venous invasion without the use of IV contrast medium and was superior to CT in differentiating lymphadenopathy from small vascular structures. Because of the limited availability, longer imaging time, and more stringent patient requirements (patients with pacemakers, intracranial aneurysm clips, life-supporting systems, and severe claustrophobia need to be excluded), the authors recommend MR only for patients with known contraindications to iodinated contrast medium, patients with prior suboptimal bolus-contrast CT studies, or patients in whom the CT findings are equivocal.

Clinical stage B prostate carcinoma: staging with MR imaging

Magnetic resonance (MR) imaging studies were performed in 29 patients with clinical findings of stage B prostatic carcinoma with use of both T1 and T2-weighted spin echo sequences. MR imaging findings were correlated with surgical/pathologic results in 18 patients who underwent an operation. Periprostatic fat, periprostatic venous plexus, seminal vesicles, and lymph nodes were assessed from MR imaging studies. When each was assessed independently, the periprostatic fat signal had a sensitivity of 29%, specificity of 100%, and accuracy of 85% in detecting extracapsular tumor extension, whereas the periprostatic venous plexus had a sensitivity of 57%, specificity of 86%, and accuracy of 80%. MR imaging had a sensitivity of 50%, specificity of 97%, and accuracy of 89% for detecting seminal vesicular involvement. When all four anatomic features were taken into consideration, MR imaging had an accuracy of 89% (16 of 18 patients) in differentiating stage B from stage C or D disease (sensitivity 87%, specificity 90%). Our data indicate that MR imaging is a promising method for staging prostatic carcinoma.

Acute renal rejection versus acute tubular necrosis in a canine model: MR evaluation

Findings of magnetic resonance (MR) imaging in acute renal rejection and acute tubular necrosis (ATN) were studied in dogs. On T1-weighted images, corticomedullary differentiation was absent in kidneys undergoing acute rejection. The loss of corticomedullary differentiation in these kidneys was secondary to a decrease in the relative signal intensity of the cortex, indicating prolongation of the T1 relaxation time of the cortex. In contrast, corticomedullary differentiation was preserved on T1-weighted images of autotransplanted kidneys and kidneys with ATN. MR imaging findings correlated with changes in water content in these three groups of kidneys. Kidneys undergoing acute rejection showed a marked increase in water content compared with kidneys in the other two groups. No change in fat content was found in any group.

Percutaneous drainage of prostatic abscesses

Percutaneous catheter drainage of intra-abdominal abscesses currently is a well established technique. We report on 2 anuric patients on maintenance hemodialysis who presented with a prostatic abscess. We elected to use a transperineal, percutaneous drainage technique. Adequate drainage was documented by pelvic computerized tomography scans and followup confirmed satisfactory long-term results.

Uterine neoplasms: MR imaging

Magnetic resonance (MR) studies were performed on 20 healthy volunteers and 41 patients with proved cervical and uterine neoplasms. MR imaging demonstrated normal uterine landmarks in all patients. On T2-weighted images, the normal uterine wall could be differentiated into three distinct layers: a central high-intensity zone, a junctional low-intensity band, and a peripheral medium-intensity area. While most of the normal cervices had only two distinct zones (central high-intensity zone and peripheral low-intensity zone), a small percentage had three layers of signal intensity, similar to the uterine body. Primary cervical and uterine neoplasms could be identified on MR images. In 18 of 22 patients with proved carcinoma, a mass with a signal intensity higher than that of normal cervical lips was seen on T2-weighted images. Endometrial carcinoma was most often identified as expansion of the central high-intensity area; discrete tumor nodules were visible in nine of 15 patients. Mixed müllerian sarcoma appeared as a large pelvic mass with complete obliteration of normal uterine landmarks. MR imaging delineates primary cervical and endometrial carcinoma better than computed tomography does.

Isolation and structure determination of crisamicin A, a new antibiotic from Micromonospora purpureochromogenes subsp. halotolerans

A new antibiotic, crisamicin A, with in vitro activity against Gram-positive bacteria, B16 murine melanoma cells, and herpes simplex, vaccinia, and vesicular stomatitis viruses, has been isolated from Micromonospora purpureochromogenes subsp. halotolerans. On the basis of 1H and 13C NMR spectroscopic, high resolution field desorption mass spectrometric, and circular dichroism studies of the antibiotic and several of its derivatives, the structure of crisamicin A has been assigned.

High resolution sonography in diagnosing testicular neoplasms: clinical significance of false positive scans

We describe the use of high resolution real-time ultrasound to evaluate scrotal masses. From August 1980 to September 1984, 249 patients underwent scrotal ultrasound using high resolution real-time scanners with 10 mHz. transducers to evaluate scrotal abnormalities. The ultrasound diagnosis was consistent with a testicular neoplasm in 20 patients. Pathological and surgical confirmation was available in all 20 patients. Only 10 of 20 patients had malignant tumors, whereas 10 had benign lesions (false positive rate of 50 per cent). Testicular lesions producing false positive studies were principally hypoechoic in 8 patients and hyperechoic in 2. Testicular neoplasms characteristically were hypoechoic with or without focal hyperechoic areas. There was 1 false negative ultrasound study. Our results suggest that radical orchiectomy should not be performed indiscriminately in all patients with testicular lesions that are sonographically suspicious for neoplasm. In selected cases with hyperechoic sonographic features associated frequently with benign testis lesions open testicular biopsy and a testis-sparing operation may be indicated.

MRI of extracranial hematomas: preliminary observations

Thirteen patients (16 examinations) with extracranial hematomas (four mediastinum, three pelvis, two calf, two psoas muscle, one liver, one abdominal wall) were examined with magnetic resonance imaging (MRI). With the exception of an acute hematoma (less than 48 hr), which did not have a distinctive MRI appearance, subacute and chronic hematomas (up to 10 months' duration) had areas of high signal intensity on both T1- (TR 500/TE 30) and T2- (TR 1500/TE 90) weighted pulse sequences. The hematomas in 10 of the patients were also evaluated by computed tomography (CT). The MRI findings complemented those seen on CT. Low-intensity parts of the hematoma on both T1- and T2-weighted images corresponded to areas of high attenuation on CT, whereas high-intensity zones correlated with regions of low attenuation. This observation was more apparent on the T1-weighted images. While older hematomas did not exhibit areas of hyperdensity that would allow a specific diagnosis on CT, MRI did demonstrate regions of high signal intensity indicative of hemorrhage.

Urography with a low osmolality contrast agent. Comparison of Hexabrix with Conray 325

A double-blind, parallel group comparison study of Hexabrix and Conray 325 for adult intravenous urography was performed. Sixty patients with a mean age of 54 years were included. Doses of contrast ranged from 0.5-1.1 ml/kg for both groups with a mean of 0.7 ml/kg. Hematology, urinary and biochemical laboratory tests were performed prior to the study in all patients and at 24 hours afterward in nearly half the group. Biochemical laboratory tests were done at 72 to 96 hours in approximately one third of the patients. Hexabrix proved satisfactory for standard urography at a chosen dose of 16 g of iodine (50 ml). There were no statistically significant differences in the diagnostic quality of the urogram in the two groups except for bladder filling. The decreased osmotic diuresis associated with Hexabrix necessitated delayed bladder filming for optimal evaluation. Excellent patient tolerance was achieved with less pain on injection with Hexabrix. There was one death in the Hexabrix group in a patient with multiple medical problems. Although the patient's medical problems appeared well controlled and did not meet specific rejection criteria, they almost certainly played a role in his death. Hexabrix may be useful for adult urography at a lower dose range, eg, 16 g iodine, than is typically used, which also may be cost effective (competitive) given the higher projected cost of the new low osmolar agents.

Prostatic carcinoma and benign prostatic hyperplasia: inability of MR imaging to distinguish between the two diseases

Forty patients with prostatic carcinoma or benign prostatic hyperplasia (BPH) underwent magnetic resonance (MR) imaging of the prostate. In vitro MR images of six prostate specimens were also obtained. The prostatic parenchyma was best evaluated by a T2-weighted spin-echo pulse sequence. The prostate both in patients with prostatic carcinoma and patients with BPH often had an inhomogeneous and nodular appearance on T2-weighted images. While most of the prostatic carcinomas appeared hyperintense relative to muscle and adjacent prostatic parenchyma, some of the hyperplastic nodules had a signal intensity similar to carcinoma. With current imaging techniques, MR imaging cannot differentiate prostatic carcinoma from BPH with certainty.