Long-term health care use and diagnosis after hospitalization for COVID-19: a retrospective matched cohort study

BACKGROUND

Knowledge pertaining to the health and health care utilization of patients after recovery from acute COVID-19 is limited. We sought to assess the frequency of new diagnoses of disease and health care use after hospitalization with COVID-19.

METHODS

We included all patients hospitalized with COVID-19 in Alberta between Mar. 5 and Dec. 31, 2020. Additionally, 2 matched controls (SARS-CoV-2 negative) per case were included and followed up until Apr. 30, 2021. New diagnoses and health care use were identified from linked administrative health data. Repeated measures were made for the periods 1-30 days, 31-60 days, 61-90 days, 91-180 days, and 180 and more days from the index date. We used multivariable regression analysis to evaluate the association of COVID-19-related hospitalization with the number of physician visits during follow-up.

RESULTS

The study sample included 3397 cases and 6658 controls. Within the first 30 days of follow-up, the case group had 37.12% (95% confidence interval [CI] 35.44% to 38.80%) more patients with physician visits, 11.12% (95% CI 9.77% to 12.46%) more patients with emergency department visits and 2.92% (95% CI 2.08% to 3.76%) more patients with hospital admissions than the control group. New diagnoses involving multiple organ systems were more common in the case group. Regression results indicated that recovering from COVID-19-related hospitalization, admission to an intensive care unit, older age, greater number of comorbidities and more prior health care use were associated with increased physician visits.

INTERPRETATION

Patients recovered from the acute phase of COVID-19 continued to have greater health care use up to 6 months after hospital discharge. Research is required to further explore the effect of post-COVID-19 conditions, pre-existing health conditions and health-seeking behaviours on health care use.

Quantitative detection of seizures with minimal-density EEG montage using phase synchrony and cross-channel coherence amplitude in critical care

Seizures frequently occur in paediatric emergency and critical care, with up to 74% being sub-clinical seizures making detection difficult. Delays in seizure detection and treatment worsen the neurological outcome of critically-ill patients. Gold-standard seizure detections using multi-channels electroencephalograms (EEG) require trained clinical physiologists to apply scalp electrodes and highly specialised neurologists to interpret and identify seizures. In this study, we extracted phase synchrony and cross-channel coherence amplitude across 4 and 8 pre-selected scalp EEG signals. Binary classification is used to determine whether the signal segment is seizure or non-seizure, and the predictions were compared against the gold-standard seizure onset markings. The application of the algorithm on a cohort of forty routinely collected EEGs from paediatric patients showed an average accuracy of 77.2 % and 76.5% using 4 and 8 channels, respectively. Clinical Relevance- This work demonstrates the feasibility of seizure detection with pre-defined 4 and 8 EEG electrodes with an average accuracy of 77%. This means for the first time seizure detection is possible using an EEG montage that can be applied readily at the bedside independent of expert input.

902 Safe Elective & Emergency Surgery During the COVID-19 Crisis: Experience of a Large Tertiary Centre During the First Wave of the Pandemic

Aim

In addition to a reduction in elective surgery, the COVID-19 pandemic has been associated with concerning rates of post-operative mortality in COVID-19 patients highlighting the threat of nosocomial transmission. Relocation of elective patients into a protected cold wing of a tertiary centre, vigilant testing and staff test, and trace were implemented to address these issues.

Method

Retrospective analysis of 5069 consecutive patients who underwent procedures in theatre from 11/03/20 – 08/09/20 was performed. Comparison of numbers of procedures was compared with the same study dates in 2019. Detailed analysis of nosocomial transmission of COVID-19 and mortality was performed using patient notes and death certificates.

Results

5854 procedures were performed in 2020 compared with 13219 in 2019, representing a reduction of 55.7%. The overall mortality in 2020 was 2.7% (135/5069). COVID-19 negative mortality was 2.36% (119/5033). 74 patients tested positive for COVID-19 at any time (1.3%); mortality amongst patients who tested positive seven days pre- to 30 days post-procedure was 5.4% (4/74). Nosocomial transmission rate was 0.27% in elective admissions (10/3773) and 0.97% in acute admissions (20/2052).

Conclusions

The first wave of the pandemic has predictably caused a significant reduction in elective activity. Our hospital infection prevention measures have kept nosocomial transmission rates low, particularly for elective admissions. We have observed lower rates of post-operative mortality in COVID-19 patients than published in other centres. Continuation of surgical services is important for patient outcomes, and essential for training the surgeons of tomorrow.

How Does the Facilitation Effort of Clinical Educators Interact With Aspects of Organizational Context to Affect Research Use in Long-term Care? Evidence From CHAID Analysis

PURPOSE

Organizational context influences the effect of facilitation efforts on research use in care settings. The interactions of these factors are complex. Therefore, the use of traditional statistical methods to examine their interrelationships is often impractical. Big Data analytics can automatically detect patterns within the data. We applied the chi-squared automatic interaction detection (CHAID) algorithm and classification tree technique to explore the dynamic and interdependent relationships between the implementation science concepts-context, facilitation, and research use.

DESIGN

Observational, cross-sectional study based on survey data collected from a representative sample of nursing homes in western Canada.

METHODS

We assessed three major constructs: (a) Conceptual research utilization (CRU) using the CRU scale; (b) facilitation of research use measured by the frequency of contacts between the frontline staff and a clinical educator, or person who brings new ideas to the care unit; and (c) organizational context at the unit level using the Alberta Context Tool (ACT). CHAID analysis was performed to detect the interactions between facilitation and context variables. Results were illustrated in a classification tree to provide a straightforward visualization.

FINDINGS

Data from 312 care units in three provinces were included in the final analysis. Results indicate significant multiway interactions between facilitation and various aspects of the organizational context, including leadership, culture, evaluation, structural resources, and organizational slack (staffing). Findings suggested the preconditions of the care settings where research use can be maximized.

CONCLUSIONS

CHAID analysis helped transform data into usable knowledge. Our findings provide insight into the dynamic relationships of facilitators' efforts and organizational context, and how these factors' interplay and their interdependence together may influence research use.

CLINICAL RELEVANCE

Knowledge of the combined effects of facilitators' efforts and various aspects of organizational context on research use can contribute to effective strategies to narrow the evidence-practice gap in care settings.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

KidsBrainIT: A New Multi-centre, Multi-disciplinary, Multi-national Paediatric Brain Monitoring Collaboration

OBJECTIVES

Validated optimal cerebral perfusion pressure (CPP) treatment thresholds in children do not exist. To improve the intensive care unit (ICU) management of the paediatric traumatic brain injury (TBI) population, we are forming a new paediatric multi-centre collaboration to recruit standardised ICU data for running and reporting upon models for assessing autoregulation and optimal CCP (CPPopt).

MATERIALS AND METHODS

We are adapting the adult BrainIT group's approach to develop a new Paediatric Brain Monitoring and Information Technology Group (KidsBrainIT), which will include a repository to store prospectively collected high-resolution physiological, clinical, and outcome data. In the first phase of this project there are 7 UK Paediatric Intensive Care Units, 1 Spanish, 1 Belgium, and 1 Romanian Centre interested in participating. In subsequent phases, we plan to open recruitment to other centres both within Europe, US and abroad. We are collaborating with the Leuven Group and plan to use their LAx (low-frequency autoregulation index), DATACAR (dynamic adaptive target of active cerebral autoregulation), CPPopt and visualisation methodologies. We also plan to use the continuous diffuse optical monitoring and tomography technology developed in Barcelona as an acute surrogate end-point for optimising brain perfusion. This technology allows non-invasive continuous monitoring of deep tissue perfusion and oxygenation in adults but its clinical application in infants and children with TBI has not been studied previously.

RESULTS

We report on the current status of setting up this new collaboration and also on pilot analyses in two centres which are the basis of our rationale for the need for a prospective validation study of CPPopt in children. Specifically, we demonstrated that CPPopt varied with time for each patient during their paediatric intensive care unit (PICU) stay, and the median overall CPPopt levels for children aged 2-6 years, 7-11 years and 12-16 years were 68.83, 68.09, and 72.17 mmHg respectively. Among survivors and patients with favourable outcome (GOS 4 and 5), there were significantly higher proportions with CPP monitoring time within CPPopt (p = 0.04 and p = 0.01 respectively).

CONCLUSIONS

There is a need and an interest in forming a multi-centre PICU collaboration for acquiring data and performing analyses for determining validated CPPopt thresholds in the paediatric TBI population. KidsBrainIT is being formed to meet that need.

A six-year trend of the healthcare cost of arthritis in a population-based cohort of older women

ABSTRACT ObjectivesTo examine the trend of the healthcare cost of arthritis in a population-based cohort of older women and to estimate the mean adjusted incremental healthcare costs, and selected percentiles. ApproachThis is a healthcare cost study based on individual-level data. Data included health survey and linked administrative data, from 2003 to 2009, from the Australian Longitudinal Study on Women’s Health. The Medicare Australia datasets include the Pharmaceutical Benefits Scheme (unit record data on claims for government-subsidized prescription medicines) and the Medicare Benefits Schedule (listing of health services subsidized by the Australian Government) datasets; they were the source for all healthcare utilization and cost data in this study. The main outcome measure was the incremental healthcare cost of arthritis (estimated from the Australian Government’s cost perspective) expressed as dollars per person per year. All costs were expressed in 2012 Australian dollars. Regression models were used to estimate the adjusted incremental costs of arthritis. The mean adjusted incremental healthcare cost of arthritis was computed using GLMs with a logarithmic-link function and a gamma distribution for costs. The adjusted incremental costs at the 25th, 50th, 75th, 90th and 95th percentiles were computed using Quantile Regression. These percentiles were chosen because cost data are skewed to the right and it was expected that there would be smaller differences between the lower percentiles but bigger differences between upper adjacent percentiles. ResultsData from 4287 women were included in the analysis. Adjusted incremental healthcare cost of arthritis did not increase significantly from 2003 to 2009. However, there were indications that costs at the lower percentiles decreased slightly over the study period while costs at higher (above 50th) percentiles increased. The estimated median cost was $480 (95% CI: $498 - $759) per person per year in 2009. However, ten percent of women had more than 300% higher cost than the “average person” with arthritis. ConclusionHealthcare cost of arthritis represents a substantial burden. However, considering only overall cost does not provide a detailed picture of expenditure. Our results suggest that higher cost patients had different experiences in arthritis cost over time, compared to patients with lower costs, although overall cost has not increased over time. As healthcare spending is concentrated in the high-cost patients, characterising these patients and formulating initiatives that target them could have a considerable impact on improving care and lowering health expenditure due to arthritis.

Discordance between self-reported arthritis and musculoskeletal signs and symptoms in older women

BACKGROUND

Arthritis is a gendered disease where women have a higher prevalence and more disability than men with arthritis of the same age. Health survey data is a major source of information for monitoring of the burden of arthritis. The validity of self-reported arthritis and the determinants of its accuracy among women have not been thoroughly studied. The objectives of this study were to: 1) examine the agreement between self-report diagnosed arthritis and musculoskeletal signs and symptoms in community-living older women; 2) estimate the sensitivity, specificity, and predictive values of self-reported arthritis; and 3) assess the factors associated with the disagreement.

METHODS

A cross-sectional survey of women was undertaken in 2012-13. The health survey asked women about diagnosed arthritis and musculoskeletal signs and symptoms. Agreement between self-reported arthritis and musculoskeletal signs symptoms was measured by Cohen's kappa. Sensitivity, specificity, and predictive values of self-reported arthritis were estimated using musculoskeletal signs and symptoms as the reference standard. Factors associated with disagreement between self-reported arthritis and the reference standard were examined using multiple logistic regression.

RESULTS

There were 223 participants self-reported arthritis and 347 did not. A greater number of participants who self-reported arthritis were obese compared to those who did not report arthritis. Those who reported arthritis had worse health, physical functioning, and arthritis symptom measures. Among the 570 participants, 198 had musculoskeletal signs and symptoms suggesting arthritis (the reference standard). Agreement between self-reported arthritis and the reference standard was moderate (kappa = 0.41). Sensitivity, specificity, and positive and negative predictive values of self-reported arthritis in older women were 66.7, 75.5, 59.2, and 81.0% respectively. Regression analysis results indicated that false-positive is associated with better health measured by the Short Form 36 physical summary score, the Health Assessment Questionnaire disability index, or the Western Ontario and McMaster University Osteoarthritis Index total score; whereas false-negative is negatively associated with these variables.

CONCLUSION

While some women who reported diagnosed arthritis did not have recent musculoskeletal signs or symptoms, others with the signs and symptoms did not report diagnosed arthritis. Researchers should use caution when employing self-reported arthritis as the case-definition in epidemiological studies.

Rheological properties of corn meal dough / Propiedades reológicas de la pasta de harina de maíz

The rheological properties of cooked corn meal dough were determined by squeezing flow, steady shear, and dynamic shear rheological methods. Under biaxial extension, the material exhibited strain- thinning behavior and the normal stress difference could be modeled as a function of biaxial strain rate, with a flow behavior index, n, of 0.38-0.52 and the biaxial consistency coefficient, Kb, ranging from 4.63 x 107 to 9.75 x 107 Pa.s". Steady and dynamic shear studies suggest that the dough exhibits shear-thinning behavior at a shear rate range of 1-40 s-1 and more viscous-like characteristics under dynamic conditions (0.5-10 s-1 frequency). Particle size distribution of the corn meal may affect some of the rheological properties ( K b, K, n) of the cooked dough. Further research is necessary to establish correlation between material variation and product quality for improvement of processes such as extrusion, baking or frying.

A 6-year trend of the healthcare costs of arthritis in a population-based cohort of older women

OBJECTIVE

To provide an accurate representation of the economic burden of arthritis by estimating the adjusted incremental healthcare cost of arthritis at multiple percentiles and reporting the cost trends across time.

METHODS

A healthcare cost study based on health survey and linked administrative data, where costs were estimated from the government's perspective in dollars per person per year. Quantile regression was used to estimate the adjusted incremental cost at the 25th, 50th, 75th, 90th, and 95th percentiles.

RESULTS

Data from 4287 older Australian women were included. The median incremental healthcare cost of arthritis was, in 2012 Australian dollars, $480 (95% CI: $498-759) in 2009; however, 5% of individuals had 5-times higher costs than the 'average individual' with arthritis. Healthcare cost of arthritis did not increase significantly from 2003 to 2009.

CONCLUSION

Healthcare cost of arthritis represents a substantial burden for the governments. Future research should continue to monitor the economic burden of arthritis.

Tuberculosis case notification by private practitioners in Pune, India: how well are we doing?

SETTING

Pimpri Chinchwad Municipal Corporation area, Pune, India.

OBJECTIVE

To assess the proportion of private practitioners (PPs) who notified tuberculosis (TB) patients during February-April 2013 and their contribution to the overall number notified, and to determine their perceived challenges in reporting TB cases.

DESIGN

Mixed-method study including an analysis of notification data, followed by in-depth interviews with PPs. Interviews were transcribed and inductive content analysis was performed to derive themes.

RESULTS

Of 831 PPs, 533 (64%) participated in case notification; of these 87 (16%) notified at least one TB case during the study period. In all, 138 TB cases were notified by PPs, accounting for 20% of the total TB cases notified. Emerging themes among perceived challenges and barriers were lack of complete knowledge about TB notification, fear of a breach of patient confidentiality, lack of a simplified operational mechanism of notification, and lack of trust and coordination with the government health system.

CONCLUSION

About two thirds of PPs participated in case notification and contributed significantly to the overall TB cases notified. India's national TB programme should focus on training PPs and targeted media communication campaigns, and establish alternative mechanisms for notification, such as the internet and mobile telephones, to overcome perceived barriers.

Equine model for soft-tissue regeneration

Soft-tissue regeneration methods currently yield suboptimal clinical outcomes due to loss of tissue volume and a lack of functional tissue regeneration. Grafted tissues and natural biomaterials often degrade or resorb too quickly, while most synthetic materials do not degrade. In previous research we demonstrated that soft-tissue regeneration can be supported using silk porous biomaterials for at least 18 months in vivo in a rodent model. In the present study, we scaled the system to a survival study using a large animal model and demonstrated the feasibility of these biomaterials for soft-tissue regeneration in adult horses. Both slow and rapidly degrading silk matrices were evaluated in subcutaneous pocket and intramuscular defect depots. We showed that we can effectively employ an equine model over 6 months to simultaneously evaluate many different implants, reducing the number of animals needed. Furthermore, we were able to tailor matrix degradation by varying the initial format of the implanted silk. Finally, we demonstrate ultrasound imaging of implants to be an effective means for tracking tissue regeneration and implant degradation.

Role of disrupted in schizophrenia 1 (DISC1) in stress-induced prefrontal cognitive dysfunction

Recent genetic studies have linked mental illness to alterations in disrupted in schizophrenia 1 (DISC1), a multifunctional scaffolding protein that regulates cyclic adenosine monophosphate (cAMP) signaling via interactions with phosphodiesterase 4 (PDE4). High levels of cAMP during stress exposure impair function of the prefrontal cortex (PFC), a region gravely afflicted in mental illness. As stress can aggravate mental illness, genetic insults to DISC1 may worsen symptoms by increasing cAMP levels. The current study examined whether viral knockdown (KD) of the Disc1 gene in rat PFC increases susceptibility to stress-induced PFC dysfunction. Rats were trained in a spatial working memory task before receiving infusions of (a) an active viral construct that knocked down Disc1 in PFC (DISC1 KD group), (b) a 'scrambled' construct that had no effect on Disc1 (Scrambled group), or (c) an active construct that reduced DISC1 expression dorsal to PFC (Anatomical Control group). Data were compared with an unoperated Control group. Cognitive performance was assessed following mild restraint stress that had no effect on normal animals. DISC1 KD rats were impaired by 1  h restraint stress, whereas Scrambled, Control, and Anatomical Control groups were unaffected. Thus, knocking down Disc1 in PFC reduced the threshold for stress-induced cognitive dysfunction, possibly through disinhibited cAMP signaling at neuronal network synapses. These findings may explain why patients with DISC1 mutations may be especially vulnerable to the effects of stress.

Prediction of noisy chaotic time series using an optimal radial basis function neural network

This paper considers the problem of optimum prediction of noisy chaotic time series using a basis function neural network, in particular, the radial basis function (RBF) network. In the noiseless environment, predicting a chaotic time series is equivalent to approximating a nonlinear function. The optimal generalization is achieved when the number of hidden units of a RBF predictor approaches infinity. When noise exists, it is shown that an optimal RBF predictor should use a finite number of hidden units. To determine the structure of an optimal RBF predictor, we propose a new technique called the cross-validated subspace method to estimate the optimum number of hidden units. While the subspace technique is used to identify a suitable number of hidden units by detecting the dimension of the subspace spanned by the signal eigenvectors, the cross validation method is applied to prevent the problem of overfitting. The effectiveness of this new method is evaluated using simulated noisy chaotic time series as well as real-life oceanic radar signals. Results show that the proposed method can find the correct number of hidden units of an RBF network for an optimal prediction.

Universal features of terahertz absorption in disordered materials

Using an analytical theory, experimental terahertz time-domain spectroscopy data, and numerical evidence, we demonstrate that the frequency dependence of the absorption coupling coefficient between far-infrared photons and atomic vibrations in disordered materials has the universal functional form, C(omega)=A+Bomega(2), where the material-specific constants A and B are related to the distributions of fluctuating charges obeying global and local charge neutrality, respectively.

Recombinant arginase as a novel anti-melanoma agent

12032

Background: BCT-100 is a recombinant arginase comprised of 329 amino acid residues. Arginase converts arginine to urea and ornithine. Previous studies suggested that melanoma cells were auxotrophic for arginine due to absence of argininosuccinate synthetase (ASS) expression. Thus, we hypothesized that recombinant arginase, BCT-100, is cytotoxic to human melanoma cells and its cytotoxicity correlates with absence of ASS expression. Methods: BCT-100 pegylated recombinant human arginase was manufactured by large scale fermentation of a recombinant B. subtilis strain LLC101 encoded with a human arginase gene. Following fermentation, the recombinant protein was extracted, purified, pegylated, and ultra-dialyzed. Ten established human melanoma cell lines were used. Cells were grown to 90% confluence, harvested, and plated at 104 cells per well in a 96-well plate and co-cultured with increasing concentrations of pegylated BCT-100 for 72 hours. CellTiter 96 Aqueous Non-radioactive Cell Proliferation Assay (Promega, Madison, WI) was used to measure percent viability, with absorbances measured at 490 nm. Total cellular RNA was isolated from established melanoma cell lines converted to cDNA at a concentration of 5 ng/ul. Quantitative real time polymerase chain reaction was performed on a 7300 Real Time PCR System, using Gene Expression Assays for ASS and GAPDH (Applied Biosystems). 10,000 fold standard curves were generated for all samples using GAPDH expression. Results: All ten cell lines demonstrated decreased viability as concentrations of BCT-100 increased. Average IC50 value was 0.11 IU/ml. Eight of the 10 cells lines have IC50 values < 0.1 IU/ml. Of the 8 cell lines with IC50< 0.1 IU/ml, all of them have low or undetectable ASS expression using quantitative RT-PCR. Of the 2cell lines with IC50 > 0.1 IU/ml, ASS expression was detected in 1 of 2. Conclusions: Arginine depletion with recombinant arginase, BCT-100, was cytotoxic to melanoma cells in vitro. The cytotoxic effect of BCT-100 on melanoma cells correlated with expression of argininosuccinate synthetase. BCT-100 is a promising novel agent for treatment of melanoma. Further in vivo experiment with BCT-100 is ongoing.

[Table: see text]

Comparison of a nested polymerase chain reaction--restriction fragment length polymorphism method, the PATH antigen detection method, and microscopy for the detection and identification of malaria parasites

A nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, the PATH antigen detection method, and light microscopy were compared for their capacity to detect and identify Plasmodium species. One hundred and thirty-six blood specimens obtained from patients suspected of having malaria were examined by each of the three methods. Forty-four specimens were positive for malaria using microscopy as the "gold standard". The sensitivity for nested PCR was 100%, and the specificity was 98%. For the detection of Plasmodium falciparum, the antigen detection method had a sensitivity of 100% and a specificity of 97%. Species identification obtained using PCR-RFLP was identical or superior to light microscopy in 42 cases (96%). Although the nested PCR-RFLP method was more sensitive and specific, the rapid turnaround time and high sensitivity of the antigen detection method makes it a useful adjunct to standard microscopy.

Cloning and sequence analysis of two copies of a 23S rRNA gene from Helicobacter pylori and association of clarithromycin resistance with 23S rRNA mutations

In this study, two identical copies of a 23S-5S gene cluster, which are separately situated within the Helicobacter pylori UA802 chromosome, were cloned and sequenced. Comparison of the DNA sequence of the H. pylori 23S rRNA gene with known sequences of other bacterial 23S rRNA genes indicated that the H. pylori UA802 23S rRNA genes are closely related to those of Campylobacter spp. and therefore belong in the proposed Proteobacteria subdivision. The 5'-terminal nucleotide T or A of the 23S rRNA is close to a Pribnow box which could be a -10 region of the transcription promoter for the 23S rRNA gene, suggesting that a posttranscriptional process is likely not involved in the maturation of the H. pylori 23S rRNA. Clinical isolates of H. pylori resistant to clarithromycin were examined by using natural transformation and pulsed-field gel electrophoresis. Cross-resistance to clarithromycin and erythromycin, which was transferred by natural transformation from the Cla(r) Ery(r) donor strain H. pylori E to the Cla(s) Ery(s) recipient strain H. pylori UA802, was associated with an single A-to-G transition mutation at position 2142 of both copies of the 23S rRNA in UA802 Cla(r) Ery(r) mutants. The transformation frequency for Cla(r) and Ery(r) was found to be approximately 2 x 10(-6) transformants per viable cell, and the MICs of both clarithromycin and erythromycin for the Cla(r) Ery(r) mutants were equal to those for the donor isolate. Our results confirmed the previous findings that mutations at positions 2142 and 2143 of the H. pylori 23S rRNA gene are responsible for clarithromycin resistance and suggest that acquisition of clarithromycin resistance in H. pylori could also result from horizontal transfer.

Altered IGFBP5 gene expression in the cerebellar external germinal layer of weaver mutant mice

The IGF system components play important roles in cerebellar development as demonstrated by their specific spatial-temporal expression. IGF-I, type I IGF receptor (IGFR-I), IGFBP2 and IGFBP5 mRNA are localized in distinct cell populations, and all are expressed at the highest levels at the peak of Purkinje cell growth, active synaptogenesis and dendritic formation. To understand IGF-I's action at the cellular level, in situ hybridization was employed to investigate the distribution of IGF system gene transcripts in the cerebellum of weaver mutant mice (wv/wv). Although located ectopically, the surviving Purkinje cells express IGF-I mRNA at the same level in wv/wv as in +/+. No alteration in the cellular distribution or mRNA levels was observed with IGFBP2, or IGFR-I mRNAs. However, the pattern of IGFBP5 expression is altered in the external germinal layer of wv/wv mice. Not only is IGFBP5 expressed by more granule cell precursors of wv/wv cerebellum, but its mRNA level is 2.3 fold that of +/+. The altered IGFBP5 gene expression in granule cell precursors may modulate the interaction of IGF-I with IGFR-I in ways that contribute to their massive death occurring in the development of wv/wv cerebellum.

Comparison of measurements of human sperm motility characteristics by the automated CellSoft system and time-exposure photomicrography

Human sperm motility characteristics in 28 semen samples with sperm concentrations less than 40 x 10(6) ml-1, as determined by the World Health Organization manual analysis (WHO, 1987), were measured by the automated CellSoft semen analyser (Cryo Resources Ltd, New York, NY, USA) using different system parameter settings (Mortimer & Mortimer, 1988a). The results were compared with those obtained by time-exposure photomicrographic (TEP) analysis. It was found that the settings of the minimum video frame rate and the threshold velocity used to distinguish motile from immotile sperm by the automated CellSoft system had a significant influence on measurements of percentage motility but not on linear velocity. At the five different parameter settings used in the present study, the automated CellSoft system gave significantly lower mean values for percentage motility in comparison with the WHO manual and TEP analyses. Measurements for linear velocity between the automated CellSoft system and TEP analyses were found not to be significantly different in these defined semen samples.

The accuracy of sperm concentration determination by the automated CellSoft semen analyzer before and after discontinuous Percoll gradient centrifugation

The automated CellSoft semen analyzer identifies human spermatozoa on the basis of user-defined values for cell size and luminosity. Previous studies have shown that the non-sperm particles usually present in seminal plasma would interfere with the computerized determination of sperm concentration by the CellSoft system. Therefore, an effective method to separate the sperm from non-sperm particles would be desirable to obtain accurate determination of sperm concentration. In the present study, sperm concentrations in 72 semen samples before and after discontinuous Percoll gradient centrifugation were determined by the automated CellSoft system and the results compared with those obtained with the routine procedure using the haemocytomer according to the World Health Organization laboratory manual. The computerized measurement caused a significant overestimation when the sperm concentration in semen was less than 80 x 10(6)/ml. Processing of human semen sample by the simple two-layer discontinuous Percoll gradient centrifugation removed the majority of non-sperm particles and the overestimation by the automated CellSoft system became significant only when the sperm concentration in the final Percoll sperm preparation was less than 10 x 10(6)/ml. These findings indicate that the automated CellSoft semen analyzer has to be improved to allow for the correction of non-sperm particles in seminal plasma or processed sperm samples before it can be used to provide sufficiently accurate sperm concentration results for routine laboratory service or research purposes.

Computer-assisted image analysis of sperm concentration in human semen before and after swim-up separation: comparison with assessment by haemocytometer

Evaluation of male fertility is based predominantly on results from semen analysis and determination of the sperm concentration is one of the main parameters of the analysis. The availability of a fully automated videomicrographic digital image analyser would offer both an objective and rapid method for determination of the sperm concentration. In the present study the sperm concentration in 327 semen samples was determined by haemocytometer according to the World Health Organization guidelines, and also by a computer-assisted digital image analyser system. Results were classified according to the routine procedure (haemocytometer) before statistical analyses. The computerized measurements caused a shift to the right in the frequency distribution of sperm concentration. Sperm concentrations were more often overestimated significantly (P less than 0.001) by the computerized measurements in semen samples with concentrations up to 80.0 x 10(6)/ml. This overestimation seemed to be caused by the presence of particles in seminal plasma that were recognized incorrectly as sperm by the computer program. The computerized digital image analyser gave an average sperm concentration of 2.2 +/- 0.6 x 10(6)/ml (mean +/- SEM) in 17 azoospermic semen samples while the routine procedure did not detect the presence of sperm cells. After removing the seminal plasma by washing and centrifugation with culture medium, and using the swim-up procedure to harvest motile sperm, the computerized measurements showed comparable results with the routine procedure for those sperm preparations (n = 44) with sperm concentrations greater than 5.0 x 10(6)/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of computerized analysis of sperm movement characteristics and differential sperm tail swelling patterns in predicting human sperm in vitro fertilizing capacity

Multivariate discriminant analysis was used to evaluate the usefulness of computer image analysis of sperm movement characteristics and differential patterns of sperm tail swelling after hypoosmotic treatment for predicting the human sperm in vitro fertilizing capacity assessed by the zona-free hamster egg penetration assay. Fifty-five semen samples, mostly normospermic, from untreated infertility clinic patients were analyzed. The % normal sperm morphology, linearity of seminal sperm movement, seminal sperm head beat frequency, mean and maximum amplitudes of lateral head displacement, and hypoosmotic sperm tail swelling patterns c, d and f were selected by multivariate discriminant analysis to be capable of discriminating the samples exhibiting the presence or the absence of sperm in vitro fertilizing capacity. The % total sperm tail swelling did not give additional information about in vitro fertilizing capacity. These preliminary data suggest that computer image analysis of sperm movement characteristics and differential evaluation of hypoosmotic sperm tail swelling might be useful for the prediction of human sperm fertility. Further prospective studies are necessary to validate their predictive functions.

Diagnostic value of sperm function tests and routine semen analyses in fertile and infertile men

The results of routine semen analyses, the zona-free hamster oocyte penetration test, the hypoosmotic swelling test, and semen adenosine triphosphate levels were studied in 66 fertile and 130 infertile men. Multivariate discriminant analysis demonstrated that routine semen parameters including semen volume, sperm count, percent sperm motility, and percent normal spermatozoa in combination could predict the fertility of these patients with 70.4% accuracy. Of the three sperm function tests evaluated, the zona-free hamster oocyte penetration test and the hypoosmotic swelling test were selected by the multivariate discriminant analysis as variables capable of providing significant information on the fertility status of the patients. However, the addition of the results of these two tests to the routine semen analysis did not significantly improve the predictability of fertility. The overall correct prediction rate was 77.6% after incorporation of the results of these two sperm function tests. In this group of subjects, the presently available sperm function tests did not predict the fertility status of a patient with a high degree of accuracy.

A ten-year follow-up study of Chinese schizophrenics in Hong Kong

One hundred and thirty-three Chinese schizophrenic patients first seen in 1965 were traced for a follow-up assessment in 1975. Eighty-two patients attended and were fully evaluated, 47 failed to attend and 4 were known to have died. The course and outcome were graded into four categories, and it was found that 65 per cent of the fully evaluated group had full and lasting remission or showed no or mild deterioration only, despite some relapses. Intra-group comparison showed that being female, a shorter duration of illness, an acute onset, symptom-groups other than disturbances of emotion and volition, and the presence of a supportive relative are factors which affect the prognosis favourably.