[Stress fractures in the military context]

BACKGROUND

Soldiers, especially as recruits, are exposed to significantly elevated stress patterns of the foot due to occupation-related marching and excessive running. This can lead to military-specific stress fractures of the metatarsals, i.e., marching fractures. The treatment and prevention of stress fractures are of particular importance in the military context due to the impact on operational capability and treatment costs. A uniform classification of these fractures does not yet exist.

OBJECTIVE

Review of stress fractures in the military setting with presentation of the incidence, risk factors, classification, treatment and prevention possibilities.

MATERIAL AND METHODS

A PubMed®-based review of the current literature on stress fractures in the military context was conducted and the results were discussed with a focus on specific military medical treatment options.

RESULTS

There are several possibilities to classify stress fractures, the most well-known being a 4-level magnetic resonance imaging (MRI)-based classification. Prevention and treatment possibilities are multifaceted but so far insufficiently validated.

CONCLUSION

Military-specific stress fractures should be grouped according to a 4-level and MRI-based classification. The treatment options include both conservative and surgical measures and should be implemented taking the patient's individual requirements into account. Preventive measures play a key role in the military context. They include the adaptation of screening tools, training and equipment and require continuous evaluation and development.

Virtual reality for assessing stereopsis performance and eye characteristics in Post-COVID

In 2019, we faced a pandemic due to the coronavirus disease (COVID-19), with millions of confirmed cases and reported deaths. Even in recovered patients, symptoms can be persistent over weeks, termed Post-COVID. In addition to common symptoms of fatigue, muscle weakness, and cognitive impairments, visual impairments have been reported. Automatic classification of COVID and Post-COVID is researched based on blood samples and radiation-based procedures, among others. However, a symptom-oriented assessment for visual impairments is still missing. Thus, we propose a Virtual Reality environment in which stereoscopic stimuli are displayed to test the patient's stereopsis performance. While performing the visual tasks, the eyes' gaze and pupil diameter are recorded. We collected data from 15 controls and 20 Post-COVID patients in a study. Therefrom, we extracted features of three main data groups, stereopsis performance, pupil diameter, and gaze behavior, and trained various classifiers. The Random Forest classifier achieved the best result with 71% accuracy. The recorded data support the classification result showing worse stereopsis performance and eye movement alterations in Post-COVID. There are limitations in the study design, comprising a small sample size and the use of an eye tracking system.

Teleglaucoma Using a New Smartphone-Based Tool for Visual Field Assessment

PRCIS

COVID-19 underlines the importance of telemedical diagnostics. The smartphone-based campimetry (Sb-C) is a newly developed digital application allowing visual field testing using a head-mounted device and a smartphone. It enables visual field screening remotely from a clinic.

BACKGROUND

Sb-C is a newly developed tool for functional ophthalmic diagnosis. This study aimed to examine the comparability of the Sb-C and Octopus 900 to ensure ophthalmological care in times of social distancing.

METHODS

Total 93 eyes were included in the study. After an ophthalmological examination, the visual field was tested by the Octopus program G1 and by the smartphone-based campimeter. The Sb-C was performed using VR glasses and an iPhone 6. The software Sb-C was downloaded and installed as SmartCampiTracker app and is examining the 30-degree visual field with 59 test positions corresponding to the G pattern of Octopus G1. Sensitivities were recorded and saved on the app. In addition, test-retest reliability was tested on 6 ophthalmologically healthy participants.

RESULTS

The group comprised 48 women and 45 men (mean age: 62.52±12.2 y) including 19 controls, 17 patients with ocular hypertension, 11 preperimetric glaucomas, and 46 perimetric glaucomas. The mean sensitivity (MS) of all points of G1 perimetry was 23.13 dB (95% CI, 22.08-24.18). The MS of the Sb-C was 21.23 dB (95% CI, 20.37-22.08). The correlation between the mean MS measured by G1 perimetry and the Sb-C was strong ( r =0.815, P <0.05). The test-retest reliability showed a correlation of r =0.591 ( P <0.05) .

CONCLUSIONS

With some technical adjustments, the Sb-C shows promise for screening glaucoma and monitoring disease progression remotely from an ophthalmologic clinic.

Antagonizing microRNA-19a/b augments PTH anabolic action and restores bone mass in osteoporosis in mice

Postmenopausal bone loss often leads to osteoporosis and fragility fractures. Bone mass can be increased by the first 34 amino acids of human parathyroid hormone (PTH), parathyroid hormone‐related protein (PTHrP), or by a monoclonal antibody against sclerostin (Scl‐Ab). Here, we show that PTH and Scl‐Ab reduce the expression of microRNA‐19a and microRNA‐19b (miR‐19a/b) in bone. In bones from patients with lower bone mass and from osteoporotic mice, miR‐19a/b expression is elevated, suggesting an inhibitory function in bone remodeling. Indeed, antagonizing miR‐19a/b in vivo increased bone mass without overt cytotoxic effects. We identified TG‐interacting factor 1 (Tgif1) as the target of miR‐19a/b in osteoblasts and essential for the increase in bone mass following miR‐19a/b inhibition. Furthermore, antagonizing miR‐19a/b augments the gain in bone mass by PTH and restores bone loss in mouse models of osteoporosis in a dual mode of action by supporting bone formation and decreasing receptor activator of NF‐κB ligand (RANKL)‐dependent bone resorption. Thus, this study identifies novel mechanisms regulating bone remodeling, which opens opportunities for new therapeutic concepts to treat bone fragility.

[Binocular vision training for professional athletes]

BACKGROUND

Optimal visual abilities including stereo acuity seem to be an important issue in sports. There is increasing evidence that stereo acuity can be sustainably improved by digital vision training even for people with good stereo acuity.

STUDY DESIGN AND TEST METHODS

In this study 31 male and female tennis players (professionals, young professionals, coaches and former professionals) completed at least 6 training units each with 192 dynamic stereoscopic tasks (N = 1152) within 6 weeks including a 4-option test with different levels of difficulty on a 3D screen at a distance of 5 m. The parameter reaction time and correctness at 15-300 arcseconds was determined. For a more precise representation of the reaction time improvement as a function of the difficulty level, the parameter reaction time increase per stereo disparity reduction (ReST) was defined.

RESULTS

Reaction time to 15 arcsecond stimuli significantly decreased from 3.9 s to 1.6 s (59%) as a result of digital vision training. The correctness at 30 arcsecond stimuli significantly increased by 23%.

DISCUSSION

The observed improvement in reaction time during vision training did not result in decreasing correctness when answering the visual questions. This represents an overall improvement in stereo vision.

CONCLUSION

Dynamic visual training over 6 weeks improves stereoscopic performance including stereo acuity, response time and correctness.

Predicting defibrillation success in out-of-hospital cardiac arrested patients: Moving beyond feature design

OBJECTIVE

Optimizing timing of defibrillation by evaluating the likelihood of a successful outcome could significantly enhance resuscitation. Previous studies employed conventional machine learning approaches and hand-crafted features to address this issue, but none have achieved superior performance to be widely accepted. This study proposes a novel approach in which predictive features are automatically learned.

METHODS

A raw 4s VF episode immediately prior to first defibrillation shock was feed to a 3-stage CNN feature extractor. Each stage was composed of 4 components: convolution, rectified linear unit activation, dropout and max-pooling. At the end of feature extractor, the feature map was flattened and connected to a fully connected multi-layer perceptron for classification. For model evaluation, a 10 fold cross-validation was employed. To balance classes, SMOTE oversampling method has been applied to minority class.

RESULTS

The obtained results show that the proposed model is highly accurate in predicting defibrillation outcome (Acc = 93.6 %). Since recommendations on classifiers suggest at least 50 % specificity and 95 % sensitivity as safe and useful predictors for defibrillation decision, the reported sensitivity of 98.8 % and specificity of 88.2 %, with the analysis speed of 3 ms/input signal, indicate that the proposed model possesses a good prospective to be implemented in automated external defibrillators.

CONCLUSIONS

The learned features demonstrate superiority over hand-crafted ones when performed on the same dataset. This approach benefits from being fully automatic by fusing feature extraction, selection and classification into a single learning model. It provides a superior strategy that can be used as a tool to guide treatment of OHCA patients in bringing optimal decision of precedence treatment. Furthermore, for encouraging replicability, the dataset has been made publicly available to the research community.

Salivary Markers for Quantitative Dehydration Estimation During Physical Exercise

Salivary markers have been proposed as noninvasive and easy-to-collect indicators of dehydrations during physical exercise. It has been demonstrated that threshold-based classifications can distinguish dehydrated from euhydrated subjects. However, considerable challenges were reported simultaneously, for example, high intersubject variabilities in these markers. Therefore, we propose a machine-learning approach to handle the intersubject variabilities and to advance from binary classifications to quantitative estimations of total body water (TBW) loss. For this purpose, salivary samples and reference values of TBW loss were collected from ten subjects during a 2-h running workout without fluid intake. The salivary samples were analyzed for previously investigated markers (osmolality, proteins) as well as additional unexplored markers (amylase, chloride, cortisol, cortisone, and potassium). Processing all these markers with a Gaussian process approach showed that quantitative TBW loss estimations are possible within an error of 0.34 l, roughly speaking, a glass of water. Furthermore, a data analysis illustrated that the salivary markers grow nonlinearly during progressive dehydration, which is in contrast to previously reported linear observations. This insight could help to develop more accurate physiological models for salivary markers and TBW loss. Such models, in turn, could facilitate even more precise TBW loss estimations in the future.

Effects of lymphatic drainage and local cryo exposition regeneration after high-intensive exercises

BACKGROUND

Recovery from exercise and competition is important in sports medicine, particularly when rest periods are short. The objective is to determine the efficacy of cryo exposition (CRY) and manual lymphatic drainage (MLD) to hasten short term recovery of muscle performance after eccentric contractions.

METHODS

In a randomized controlled trial, 30 healthy sport students (21 males, 9 females; age: 25.7±2.8 years) performed 4×20 eccentric contractions of knee extensors, followed by 30 min MLD, CRY, or rest (RST) under controlled laboratory environment. Maximal voluntary contractions (MVC), electrically induced muscle fatigue (FI), and electrically induced tetani (EIT) at low (T2: 20 Hz) and high frequencies were tested.

RESULTS

Force decline and recovery kinetics regarding MVC, FI, and EIT did not differ significantly (p<0.05) between groups. That is, 24 h after the intervention, MVC (MLD: 80.9±5.5%; CRY: 81.1±8.5%; RST: 83.5±7.3%), FI (MLD: 83.2±23.7%; CRY: 81.2±38.8%; RST: 93.2±22.9%), and EIT (T1: MLD: 53.0±29.5%; CRY: 39.0±32.9%; RST: 46.3±26.1%; T2: MLD: 84.2±27.2%; CRY: 64.2±24.2%; RST: 66.6±22.3%) were similarly depressed irrespective of applied treatments.

CONCLUSION

Neither CRY nor MLD hastened the recovery of muscle performance, when applied for 30 min. Identification number of the Primary Registry Network: DRKS00007608.

Effects of stimulation frequency, amplitude, and impulse width on muscle fatigue

INTRODUCTION

We investigated the effect of stimulation intensity (in percent of maximal tolerated stimulation current, mTSC), frequency, and impulse width on muscle fatigue.

METHODS

Using a randomized crossover design, 6 parameter combinations (80% mTSC, 80 Hz, 400 μs; 60% mTSC, 80 Hz, 400 μs; 80% mTSC, 20 Hz, 400 μs; 60% mTSC, 20 Hz, 400 μs; 80% mTSC, 80 Hz, 150 μs; 60% mTSC, 80 Hz, 150 μs) were tested in both legs of 13 athletic men (age 26 ± 2.3). The slope of the linear regression line over all tetani (FIS) and the number of tetani whose force was above 50% of the initial tetanus (FIN) were used to quantify fatigue.

RESULTS

FIS and FIN were significantly lower in high-frequency protocols. No effects on FIS and FIN were found for intensity and impulse width.

CONCLUSIONS

Stimulation frequency, but not impulse width or intensity, affected fatigue kinetics.

A Temperature-Based Bioimpedance Correction for Water Loss Estimation During Sports

The amount of total body water (TBW) can be estimated based on bioimpedance measurements of the human body. In sports, TBW estimations are of importance because mild water losses can impair muscular strength and aerobic endurance. Severe water losses can even be life threatening. TBW estimations based on bioimpedance, however, fail during sports because the increased body temperature corrupts bioimpedance measurements. Therefore, this paper proposes a machine learning method that eliminates the effects of increased temperature on bioimpedance and, consequently, reveals the changes in bioimpedance that are due to TBW loss. This is facilitated by utilizing changes in skin and core temperature. The method was evaluated in a study in which bioimpedance, temperature, and TBW loss were recorded every 15 min during a 2-h running workout. The evaluation demonstrated that the proposed method is able to reduce the error of TBW loss estimation by up to 71%, compared to the state of art. In the future, the proposed method in combination with portable bioimpedance devices might facilitate the development of wearable systems for continuous and noninvasive TBW loss monitoring during sports.

On sweat analysis for quantitative estimation of dehydration during physical exercise

Quantitative estimation of water loss during physical exercise is of importance because dehydration can impair both muscular strength and aerobic endurance. A physiological indicator for deficit of total body water (TBW) might be the concentration of electrolytes in sweat. It has been shown that concentrations differ after physical exercise depending on whether water loss was replaced by fluid intake or not. However, to the best of our knowledge, this fact has not been examined for its potential to quantitatively estimate TBW loss. Therefore, we conducted a study in which sweat samples were collected continuously during two hours of physical exercise without fluid intake. A statistical analysis of these sweat samples revealed significant correlations between chloride concentration in sweat and TBW loss (r = 0.41, p <; 0.01), and between sweat osmolality and TBW loss (r = 0.43, p <; 0.01). A quantitative estimation of TBW loss resulted in a mean absolute error of 0.49 l per estimation. Although the precision has to be improved for practical applications, the present results suggest that TBW loss estimation could be realizable using sweat samples.

Data mining in the U.S. National Toxicology Program (NTP) database reveals a potential bias regarding liver tumors in rodents irrespective of the test agent

Long-term studies in rodents are the benchmark method to assess carcinogenicity of single substances, mixtures, and multi-compounds. In such a study, mice and rats are exposed to a test agent at different dose levels for a period of two years and the incidence of neoplastic lesions is observed. However, this two-year study is also expensive, time-consuming, and burdensome to the experimental animals. Consequently, various alternatives have been proposed in the literature to assess carcinogenicity on basis of short-term studies. In this paper, we investigated if effects on the rodents' liver weight in short-term studies can be exploited to predict the incidence of liver tumors in long-term studies. A set of 138 paired short- and long-term studies was compiled from the database of the U.S. National Toxicology Program (NTP), more precisely, from (long-term) two-year carcinogenicity studies and their preceding (short-term) dose finding studies. In this set, data mining methods revealed patterns that can predict the incidence of liver tumors with accuracies of over 80%. However, the results simultaneously indicated a potential bias regarding liver tumors in two-year NTP studies. The incidence of liver tumors does not only depend on the test agent but also on other confounding factors in the study design, e.g., species, sex, type of substance. We recommend considering this bias if the hazard or risk of a test agent is assessed on basis of a NTP carcinogenicity study.

Cardiac function in mild primary hyperparathyroidism and the outcome after parathyroidectomy

OBJECTIVE

Primary hyperparathyroidism (PHPT) is associated with cardiovascular morbidity. The extent of cardiovascular abnormalities in patients with mild-asymptomatic disease is unclear. Using sensitive echocardiographic methods, we compared cardiac structure and function in patients with mild PHPT and in healthy controls, and evaluated the changes after parathyroidectomy (PTX).

METHODS

In a prospective case-control design, we studied 51 PHPT patients without any cardiovascular risk factors/diseases and 51 healthy matched controls. Cardiac structure, and systolic and diastolic function were evaluated by echocardiography and Doppler tissue imaging (DTI). Blood pressure (BP) and heart rate were measured.

RESULTS

We observed no differences in systolic or diastolic function or in cardiac morphology between the PHPT patients and the age-matched healthy controls. The regional peak systolic myocardial velocities (S') measured with DTI decreased at all sites (P<0.05) after PTX (tricuspid annulus 14.23+/-1.85 to 13.48+/-1.79, septal 8.48+/-0.96 to 7.97+/-0.85, and lateral 9.61+/-2.05 to 8.87+/-1.63 cm/s, part of the mitral annulus). At baseline, systolic BP was higher in patients compared to controls (127.6+/-17.1 vs 119.6+/-12.6 mmHg, P<0.05). After PTX, both systolic (127.6+/-17.1 vs 124.6+/-16.6 mmHg, P<0.05) and diastolic (80.3+/-9.6 vs 78.4+/-8.6 mmHg, P<0.05) BP decreased.

CONCLUSIONS

Our results indicate that patients with PHPT without cardiovascular risk factors have a normal global systolic and diastolic function and cardiac morphology. BP and the systolic velocities were marginally reduced after PTX, but reflected the values of the control group. Our findings warrant further investigation of the clinical and prognostic significance of these possibly disease-related inotropic effects.

miR-29b expression is associated with disease-free survival in patients with ovarian serous carcinoma

Micro-RNAs are a group of small noncoding RNAs approximately 22 nucleotides in length. Recent work has shown differential expression of mature micro-RNAs in human cancers. We characterized the alteration in expression of miR-29b in ovarian serous carcinoma. miR-29b expression was analyzed using quantitative stem-loop reverse transcriptase polymerase chain reaction on a set of 50 formalin-fixed, paraffin-embedded ovarian serous carcinoma samples. Protein expression of p53, estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, Ki-67, and insulinlike growth factor 1 was quantified in the corresponding tissue microarray. The expression profile of miR-29b was correlated with clinicopathological and patient survival data. We provide definitive evidence that miR-29b is down-regulated in a significant proportion of ovarian serous carcinomas and is associated with specific clinicopathological features, most notably high miR-29b expression being associated with reduced disease-free survival.

Suicide after bereavement: an overlooked problem

BACKGROUND

To examine the effect of time on suicide after bereavement among widowed persons.

METHOD

The data were extracted from Swiss mortality statistics for the period 1987-2005. The time between bereavement and subsequent death, specifically by suicide, was determined by linkage of individual records of married persons. The suicide rates and the standardized mortality ratios in the first week/month/year of widowhood were calculated based on person-year calculations.

RESULTS

The annualized suicide rates in widowed persons were highest in the first week after bereavement: 941 males and 207 females per 100,000. The corresponding standardized mortality ratios were approximately 34 and 19 respectively. In the first month(s) after bereavement, the rates and the ratios decreased, first rapidly, then gradually. Except in older widows, they did not reach the baseline levels during the first year after bereavement.

CONCLUSIONS

The suicide risk of widowed persons is increased in the days, weeks and months after bereavement. Widowed persons are a clear-cut risk group under the aegis of undertakers, priests and general practitioners.

Dissociation of depletional induction and posttransplant lymphoproliferative disease in kidney recipients treated with alemtuzumab

Transplant patients are at the risk for posttransplant lymphoproliferative disease (PTLD), a virally-driven malignancy. Induction with the depleting antibody preparations Thymoglobulin and OKT3 is associated with PTLD suggesting that the T-cell depletion increases PTLD risk. We therefore studied 59 560 kidney recipients from the Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) database for a relationship between induction agent use and PTLD. Two agents with comparable T-cell depletional effects, alemtuzumab and Thymoglobulin, were compared to nondepletional induction agents or no induction. The overall incidence of PTLD was 0.46% and differed significantly by induction strategy (p < 0.01): without induction (0.43%), basiliximab (0.38%), daclizumab (0.33%), Thymoglobulin (0.67%) and alemtuzumab (0.37%). Thymoglobulin was associated with significantly increased PTLD risk (p = 0.0025), but alemtuzumab (p = 0.74), basiliximab (p = 0.33) and daclizumab, which trended toward a protective effect (p = 0.06), were not. Alemtuzumab and Thymoglobulin treated patients did not differ in any established parameter affecting PTLD risk although alemtuzumab is known to have a more pronounced B-cell depleting effect. Interestingly, maintenance therapy with an mTOR inhibitor was strongly associated with PTLD (0.71%, p < 0.0001). Thus, depletional induction is not an independent risk factor for PTLD. Rather, maintenance drug selection or perhaps the balance between B- and T-cell depletion may be more relevant determinants of PTLD risk.

Topoisomerase II-alpha expression increases with increasing Gleason score and with hormone insensitivity in prostate carcinoma

AIM

To investigate and compare topoisomerase II-alpha expression in benign prostatic hyperplasia (BPH), prostate cancer of varying Gleason scores and hormone-insensitive prostate cancer.

METHODS

The immunohistochemical expression of topoisomerase II-alpha antibody in the above-mentioned diagnostic categories was investigated and compared.

RESULTS

Increased expression of topoisomerase II-alpha was seen in the prostate cancers of Gleason scores 7 and 8-10 (p = 0.000) compared with prostate cancers of Gleason score 6 and BPH (p = 0.245). Statistically significant differences were found in the topoisomerase II-alpha gene expression between prostate cancers categorised by Gleason Score. Also, increased expression of topoisomerase II-alpha was seen in the known hormone-resistant prostate carcinomas compared with prostate cancers with no hormone treatment in the subgroup with Gleason scores 8-10, which approached statistical significance (p = 0.081). No statistically significant difference was observed in topoisomerase II-alpha expression between the groups with BPH and prostate carcinoma of Gleason score 6 (p = 0.245).

CONCLUSION

Topoisomerase II-alpha expression was found to increase with the known prognostic marker Gleason score and with hormone insensitivity. Objective evidence is provided for clinical trials with drugs targeting topoisomerase II-alpha to be targeted to patients with prostate cancers of Gleason Score >6 and, in particular, prostate cancers of Gleason Scores 8-10.

Dynamics of Campylobacter spp. spread investigated in 14 broiler flocks in Switzerland

Ten conventional and four extensive outdoor broiler flocks, distributed over nine farms, were investigated twice per week during a 35-58-day rearing period to observe the dynamics of Campylobacter spp. spread within these flocks. Strains isolated during this period were genotyped by restriction fragment length polymorphism analysis of the flaA gene and macrorestriction profiling with pulsed field gel electrophoresis. A total of 4112 samples were collected; 157 (3.8%) of these samples were Campylobacter positive, with all C. jejuni. The positive samples were distributed over three conventional and two extensive outdoor flocks on five farms. These five positive flocks were colonized from the fifth to the seventh week of age and remained colonized until slaughter. Each of the flocks showed a flock-specific genotype of Campylobacter that predominated until slaughter. Presuming different ways of entry, a combination of this fact and the observed dynamics of C. jejuni spread within the flocks indicates that a single source from the environment may have been responsible for the colonization of each flock. These conclusions may serve to further develop combat strategies at farm level.

p16INK4A, CDC6, and MCM5: predictive biomarkers in cervical preinvasive neoplasia and cervical cancer

AIM

To analyse and compare expression patterns of three potential biomarkers-p16(INK4A), CDC6, and MCM5-and evaluate their use as predictive biomarkers in squamous and glandular cervical preinvasive neoplasia.

METHODS

Immunocytochemical analysis of p16(INK4A), MCM5, and CDC6 expression was performed on 20 normal, 38 cervical intraepithelial neoplasia 1 (CIN1), 33 CIN2, 46 CIN3, 10 squamous cell carcinoma, 19 cervical glandular intraepithelial neoplasia (cGIN), and 10 adenocarcinoma samples. Staining intensity was assessed using a 0-3 scoring system. p16(INK4A), MCM5, and CDC6 expression was also examined in ThinPrep slides exhibiting mild, moderate, and severe dyskaryosis. Human papillomavirus (HPV) was detected using a modified SYBR green assay. Fluorogenic polymerase chain reaction (PCR) and solution phase PCR were used for specific HPV typing.

RESULTS

All three markers showed a linear correlation between expression and grade of dysplasia. p16(INK4A) and MCM5 protein expression was upregulated in all grades of squamous and glandular dysplasia. CDC6 protein was preferentially expressed in high grade lesions and in invasive squamous cell carcinoma.

CONCLUSION

p16(INK4A) expression was closely associated with high risk HPV infection-all grades of squamous and glandular cervical lesions were immunohistochemically positive. MCM5 staining intensity was independent of high risk HPV infection, highlighting its potential as a biomarker in both HPV dependent and independent cervical dysplasia. CDC6 may be a biomarker of high grade and invasive lesions of the cervix, with limited use in low grade dysplasia. p16(INK4A) was the most reliable marker of cervical dysplasia. Combinations of dysplastic biomarkers may be useful in difficult diagnostic cases.

P16INK4A positivity in benign, premalignant and malignant cervical glandular lesions: a potential diagnostic problem

A wide array of immunohistochemical markers have been evaluated with respect to their specificity in staining dysplastic cervical cells in cervical biopsies and cervical cytological smears. However, there is still a significant demand for better biomarkers to identify neoplastic cervical glandular and squamous epithelial cells precisely. The CDKN2A gene, located on chromosome 9p21, encodes the tumour suppressor protein, p16INK4A, which decelerates the cell cycle by inactivating CDK4 and CDK6. The aim of this study was to compare and contrast the expression pattern of p16INK4A in benign and neoplastic glandular lesions and tubo-endometrioid metaplasia. All cases in each category displayed some p16INK4A expression. Adenocarcinoma and in situ cases showed a combination of intense nuclear and cytoplasmic staining. It was observed that all cases of tubo-endometrioid metaplasia showed occasional nuclear positivity and definite cytoplasmic staining. These findings may have important implications for the potential utility of p16INK4A as a biomarker for glandular dysplastic lesions. While p16INK4A has been demonstrated to be an excellent marker of cervical dysplasia in squamous neoplastic lesions of the cervix, it has potential pitfalls in cervical glandular lesions that may limit the utility of this biomarker in resolving the nature of suspicious glandular lesions, particularly in cytopathology.

p16INK4A as a marker for cervical dyskaryosis: CIN and cGIN in cervical biopsies and ThinPrep smears

AIM

To examine the potential of p16(INK4A) as a biomarker for dysplastic squamous and glandular cells of the cervix in tissue sections and ThinPrep smears.

METHODS

Immunocytochemical analysis of p16(INK4A) expression was performed on 22 normal cervical tissue samples, five cervical glandular intraepithelial neoplasia (cGIN), 38 cervical intraepithelial neoplasia 1 (CIN1), 33 CIN2, 46 CIN3, and 10 invasive cancer cases (eight squamous and two adenocarcinomas). All samples were formalin fixed and paraffin wax embedded, and immunohistochemical analysis was carried out using a mouse monoclonal anti-p16(INK4A) antibody after antigen unmasking. The staining intensity was assessed using a 0 to 3 scoring system. In addition, the expression status of p16(INK4A) was examined in 12 normal ThinPrep smears, one smear exhibiting cGIN, and a total of 20 smears exhibiting mild, moderate, and severe dyskaryosis. Human papillomavirus (HPV) detection was carried out using a modified SYBR green assay system. Fluorogenic polymerase chain reaction (PCR) and solution phase PCR were used for specific HPV typing.

RESULTS

p16(INK4A) immunoreactivity was absent in all normal cervical tissues examined. Dysplastic squamous and glandular cells were positive for p16(INK4A) expression in all cases included in this study, except for one CIN3 case. p16(INK4A) expression was mainly nuclear in CIN1 cases, and both nuclear and cytoplasmic in CIN2, CIN3, cGIN, and invasive cases. All cases positive for HPV expressed the p16(INK4A) protein, although not all cases found positive for p16(INK4A) were HPV positive. In general, the p16(INK4A) staining intensity was lower in cases negative for HPV or those containing a low risk HPV type.

CONCLUSION

This pattern of overexpression demonstrates the potential use of p16(INK4A) as a diagnostic marker for cervical squamous and also glandular neoplastic lesions. In addition, the technique can be used to identify individual dyskaryotic cells in ThinPrep smears. Thus, p16(INK4A) is a useful marker of cervical dyskaryosis.

Evaluation of liquid-based cytology in cervical screening of high-risk populations: a split study of colposcopy and genito-urinary medicine populations

A split study evaluated the ThinPrep(R) PapTesttrade mark (TP; Cytyc Corp., Boxborough, MA) compared with current methodologies of cervical cytology in two high-risk cohorts. One thousand, three hundred cases from a colposcopy clinic and a genito-urinary medicine outpatient clinic were examined. The TP reported increased detection of all grades of dyskaryosis (mild, moderate and severe; + 4.5%) and a decrease in borderline and unsuitable cases (- 4.9%). Four cases of high-grade dyskaryosis (moderate or severe) were detected only using the TP, while an additional four cases classified as high-grade dyskaryosis with the TP were reported as borderline by our conventional methods. The split-study finding of increased sensitivity with the TP provides for improved clinical management of patients in our high-risk cohorts.

Chronic effects of ACE-inhibition (quinapril) and angiotensin-II-type-1 receptor blockade (losartan) on atrial natriuretic peptide in brain nuclei of rats with experimental myocardial infarction

Alterations of the central nervous system may be important for imbalance of cardiovascular and fluid regulation in heart failure. The central renin-angiotensin and atrial natriuretic peptide (ANP) systems act as mutual antagonists. The effects of angiotensin converting enzyme (ACE) inhibition (quinapril, 6 mg/kg/day) and angiotensin II type 1 (AT1) receptor blockade (losartan, 10 mg/kg/day) on ANP levels in 18 selected, microdissected brain nuclei were determined in sham-operated rats and rats with left ventricular dysfunction 8 weeks after myocardial infarction (MI). Plasma ANP tended to increase in MI rats and was further increased by quinapril. ANP was decreased in 12 brain areas of MI rats. ANP concentration was also significantly decreased by quinapril in six brain nuclei including subfornical organ and organum vasculosum laminae terminalis (areas lacking blood-brain barrier), and by losartan in 16 brain nuclei outside and within the blood-brain barrier in sham operated rats. However, both quinapril and losartan prevented a further reduction of central ANP as a result of myocardial infarction. These data suggest that there are effects on central ANP that result from chronic left ventricular dysfunction as well as an ACE-inhibitor and AT1-antagonist. Mechanisms and consequences of central ANP depression remain unclear. They could, however, support systemic vasoconstriction and sodium and fluid retention.

Mechanism of action of the calcium-sensing receptor in human antral gastrin cells

BACKGROUND AND AIMS

Human G cells express the calcium-sensing receptor and respond to extracellular calcium by releasing gastrin. However, the receptor on G cells is insensitive to serum calcium levels. We investigated whether this is a result of differential regulation of signaling pathways compared with parathyroid or calcitonin cells.

METHODS

Gastrin release from primary cultures of human antral epithelial cells enriched for G cells (35%) was measured by radioimmunoassay. G cells were stimulated by increasing extracellular calcium concentration for 1 hour in the presence or absence of antagonists of specific intracellular signaling pathways. Intracellular calcium levels were monitored to evaluate the effect of the antagonists on calcium influx.

RESULTS

Inhibition of phospholipase C decreased calcium-stimulated gastrin release, but blockers of adenylate cyclase, phospholipase A(2), or mitogen-activated protein kinase had no effect. Inhibition of protein kinase C, nonselective cation channels, and phosphodiesterase increased basal and calcium-stimulated gastrin release while decreasing calcium influx. These data were consistent with basally active phosphodiesterase.

CONCLUSIONS

The calcium-sensing receptor on the G cell activates phospholipase C and opens nonselective cation channels, resulting in an influx of extracellular calcium. Protein kinase C isozymes expressed by the G cells play multiple roles regulating both gastrin secretion and phosphodiesterase activity.

Fetal DNA in maternal circulation of first-trimester spontaneous abortions

OBJECTIVE

To establish whether fetal DNA can be identified in the maternal circulation in first-trimester spontaneous abortions.

METHODS

Women with confirmed spontaneous abortions and no histories of previous pregnancy were recruited. Peripheral venous blood samples were obtained and DNA extracted. Real-time quantitative polymerase chain reaction was done using SRY and beta-actin systems for calculating fetal and total DNA, respectively.

RESULTS

Of 25 women, SRY-specific signals were detected in 11 indicating that the abortions were male. The remaining 14 were negative for the SRY gene. Women with positive results were of similar gestational age to those who were negative (mean 68.4 and 69.0 days). Fetal:total DNA ratio was calculated for positive samples and ranged from 15.8 to 360.1 x 10(+3). Mean ratio was 99.4 x 10(+3) and median was 67.5 x 10(+3).

CONCLUSION

Fetal DNA is present in the maternal circulation of first-trimester spontaneous abortions.

Identification and analysis of Lydia, a LTR retrotransposon from Lymantria dispar

Degenerative PCR primers to conserved amino acid motifs were used to identify an LTR retrotransposon from Lymantria dispar. The isolated retrotransposon, Lydia, is 6655 base pairs (bp) in length and contains perfect 300 bp terminal repeats. The identified gag and pol related ORFs have a high degree of similarity to the corresponding regions of the retrotransposon Ted from Trichoplusia ni, although several reading frameshifts and missense mutations are evident. The high degree of similarity between Lydia and Ted LTRs lends support for a family of lepidopteran retrotransposons. Southern blot analysis of individuals from two geographically distinct gypsy moth populations demonstrates that Lydia is found in both populations and the position of this element within the genome of these isolated populations is variable.

Doppler tissue imaging in congestive heart failure patients due to diastolic or systolic dysfunction: a comparison with Doppler echocardiography and the atrio-ventricular plane displacement technique

BACKGROUND

Doppler tissue imaging (DTI) is an echocardiographic technique by which regional contractility, relaxation properties and time intervals are obtained easily. DTI has been reported to be relatively pre-load independent and could, in comparison with the commonly used mitral pulse wave Doppler (MPWD) method, be of clinical interest for identification of patients with diastolic dysfunction. The atrio-ventricular plane displacement (AVPD) method is an established technique to assess left ventricular systolic function.

AIMS

To determine the pulsed Doppler DTI-pattern in patients with heart failure and to examine whether it has a similar capacity as MPWD and AVPD to diagnose diastolic dysfunction.

METHODS

We studied 15 controls without congestive heart failure (CHF), 15 patients with diastolic (EF>45%+CHF) and 15 patients with systolic (EF<35%+CHF) left ventricular dysfunction and CHF.

RESULTS

The DTI maximal velocities during systole (s), early filling wave (e) and atrial filling wave (a), decrease with reduced left ventricular ejection fraction, r=0.75, r=0.56 and r=0.66 (P<0.001) and regional isovolumetric contraction and intraventricular relaxation time measured by DTI are prolonged, r=0.59 and r=0.73, respectively (P<0.001). The 15 patients with diastolic heart failure were identified by MPWD or DTI but only 11 by AVPD with 8, 10 and 9 false-positive, respectively (P<0.01, P<0.05 and NS).

CONCLUSIONS

Regional DTI show a consistent pattern in patients with left ventricular dysfunction and heart failure. Regional DTI has similar accuracy as MPWD in identifying diastolic heart failure patients and is superior to the AVPD technique. DTI may be a useful diagnostic tool in diastolic heart failure patients.

Influence of age and cardiovascular factors on regional pulsed wave Doppler myocardial imaging indices

AIMS

To describe the influence of age and other cardiovascular factors on regional pulsed wave Doppler myocardial imaging (DMI), and to compare DMI with conventional transmitral echocardiography and the atrioventricular plane displacement (AVPD) method.

METHODS AND RESULTS

Eighty-eight healthy subjects aged 20-81 years were examined by DMI, performed in the intraventricular septum just below the mitral annulus and in the corresponding lateral region, by transmitral pulsed wave Doppler echocardiography, and by AVPD. The DMI peak velocity during the left ventricular (LV) early filling phase (e), decreased with age from 12.3 +/- 2.3 cm/s in the youngest to 7.0 +/- 1.7 cm/s in the oldest tercentile (r=- 0.76, P<0.001). The DMI peak velocity during atrial contraction (a), increased from 7.5 +/- 2.2 cm/s in the youngest to 9.7 +/- 1.7 cm/s in the oldest tercentile (r=0.41, P<0.001). The DMI systolic peak velocity (s), decreased with age from 8.2 +/- 1.1 (youngest tercentile) to 6.9 +/- 1.1 (oldest tercentile), r=-0.39, P<0.001 cm/s, while the fraction shortening of the LV increased from 33.7 +/- 4.1 to 38.2 +/- 5.9% (r=0.36, P<0.01). The DMI e/a correlated with the transmitral early/atrial (E/A) (r=0.83, P<0.001) and with the AVPD measurement of diastolic function AV-LA/AV-mean (r=0.82, P<0.001). The DMI e velocity correlated with the transmitral E velocity (r=0.38, P<0.001). In the multiple regression analysis of DMI e, age was the strongest factor and LV mass index correlated inversely and independently with e. No DMI variables were influenced by gender, while transmitral E correlated with gender. The LV dimension variables explained 35% (R2 adjusted) of the DMI e velocity changes; only 7% of the transmitral E changes were explained by those variables.

CONCLUSION

Regional DMI indices are highly age-dependent. In comparision with conventional echocardiography, regional DMI might be more influenced by LV geometry and by myocardial structural changes. These findings suggest a complementary role for regional DMI to conventional echocardiography for the assessment of myocardial function.

Cellular localisation of HHV-8 in Castleman's disease: is there a link with lymph node vascularity?

AIMS

Human herpesvirus 8 (HHV-8) has been identified in multicentric Castleman's disease and in angioimmunoblastic lymphadenopathies. However, the presence of the virus does not necessarily indicate an aetiological role in these conditions. This study investigates the cell types infected by HHV-8 in Castleman's disease and examines the correlation between HHV-8 and Castleman's disease lymph node angiogenesis.

METHODS

Sixteen formalin fixed, paraffin wax embedded samples from patients with Castleman's disease (six multicentric, 10 solitary) were examined for the presence of HHV-8 using the polymerase chain reaction (PCR), non-isotopic in situ hybridisation, PCR in situ hybridisation (PCR-ISH), and real time quantitative TaqMan PCR to HHV-8 open reading frame 26 (ORF-26), and viral (v)-cyclin encoding regions. Vascularity was assessed using CD34, CD31, and factor VIII immunocytochemistry, and lymph nodes were scored as "low" or "high".

RESULTS

Five multicentric Castleman's disease and two solitary Castleman's disease biopsies were positive for HHV-8. HHV-8 was identified in approximately 10% of intranodal B lymphocytes, in endothelial cells, and in subcapsular spindle cell proliferations. The copy number of HHV-8 was low at 10-50 copies/1000 cells. The highest copy number was in subcapsular spindle cells. There was no correlation between vascularity score and HHV-8 status.

CONCLUSION

The preferential localisation of HHV-8 in subcapsular spindle cell proliferations (where early intranodal Kaposi's sarcoma initiates) and endothelial cells in Castleman's disease might finally explain the link between intranodal Kaposi's sarcoma and Castleman's disease.

Localisation of HHV-8 in AIDS related lymphadenopathy

BACKGROUND

Many lymph node abnormalities have been described in AIDS. These include opportunistic infections that sometimes result in spindle cell pseudotumours, Kaposi's sarcoma (KS), malignant lymphoma (Hodgkin's and non-Hodgkin's), and florid reactive hyperplasia. Among these, reactive hyperplasia is the most common manifestation of AIDS related lymphadenopathy.

AIM

To examine whether human herpesvirus 8 (HHV-8), the aetiological agent of KS, can be localised in AIDS related lymphadenopathy and whether its appearance in such nodes is predictive of Kaposi's sarcoma development.

METHODS

A series of human immunodeficiency virus (HIV) positive men (n = 21) with AIDS related lymphadenopathy who at the time of presentation had KS or subsequently developed KS (n = 5) were examined. The prevalence of HHV-8 was assessed in these patients using solution phase polymerase chain reaction (PCR), real time TaqMan quantitative PCR, and in cell amplification techniques (PCR in situ hybridisation (PCR-ISH) and labelled primer driven in cell amplification).

RESULTS

Using standard solution phase PCR in a nested format, only two of the 21 patients with AIDS related lymphadenopathy were positive for HHV-8. The lymph node of one of these patients contained KS lesions. Three HHV-8 positive patients were identified using TaqMan PCR (the original two positive patients and one additional patient). All of the positive patients either subsequently developed KS (n = 2) or had KS at the time of diagnosis (n = 1). Two additional patients subsequently developed KS, but were negative for HHV-8 by solution phase PCR and TaqMan PCR. Using PCR-ISH, HHV-8 amplicons were identified in some lymphoid cells (in one patient) and in spindle cells of the KS lesion in another. The positive lymphoid cells were predominantly concentrated in B cell areas of the affected lymph nodes, confirming the B cell tropism exhibited by HHV-8.

CONCLUSIONS

The presence of HHV-8 in AIDS related lymphadenopathy is predictive of KS development and probably represents seeding of HHV-8 infected B cells from the peripheral blood. These findings support a role for HHV-8 in the pathobiology of KS.

Improved in situ detection method for telomeric tandem repeats in metaphase spreads and interphase nuclei

Peptide nucleic acid technology (PNA) has become an extremely useful tool and promises to impact on molecular biology and diagnostics. These synthetic DNA analogues pair with DNA and RNA molecules according to Watson and Crick base pairing rules. This paper describes a sensitive and quick fluorescent in situ hybridisation (ISH) technique to determine DNA telomere repeat sequences (TTA GGG)n using epifluorescence microscopy. Telomeres are special, repeated structures at the end of each eukaryotic chromosome and serve as protective caps to prevent DNA rearrangements and fusion of chromosomes. A model system has been developed, using stimulated peripheral blood lymphocytes, which facilitates simultaneous detection of telomeres in metaphase as well as in interphase nuclei. A fluorescein isothiocyanate labelled PNA probe (18 mer) directed against complementary telomeric sequences at the end of each chromosome is used. In addition, a simple, easy to perform PNA-ISH protocol is described that overcomes common hybridisation problems encountered using DNA and RNA oligoprobes. Furthermore, the usefulness of a chromogenic immunocytochemical detection system is shown for PNA-ISH.

The role of protein kinase C isozymes in bombesin-stimulated gastrin release from human antral gastrin cells

Two of the most effective stimuli of gastrin release from human antral G cells are bombesin and phorbol esters. Both agonists result in activation of the protein kinase C family of isozymes, however, the exact contribution of protein kinase C to the resultant release of gastrin has been difficult to assess, possibly due to the presence of multiple protein kinase C isozymes in the G cells. The results of the present study demonstrated that the human antral G cells expressed 6 protein kinase C isozymes alpha, gamma, theta, epsilon, zeta, and mu. Of these protein kinase C, gamma and theta were translocated by stimulation of the cells by either 10 nM bombesin or 1 nM phorbol ester. Inhibition of protein kinase Cmu (localized to the Golgi complex) did not decrease bombesin-stimulated gastrin release indicating that this isozyme was not involved in the secretory process. The use of selective antagonists of the calcium-sensitive conventional protein kinase C subgroup resulted in an increase in bombesin-stimulated gastrin release and indicated that protein kinase Cgamma was involved in the desensitization of the bombesin response.

Association between HLA-DR1 and -DR3 antigens and unexplained repeated miscarriage

Few, mostly small, studies have investigated the distribution of HLA class II antigens among women with unexplained recurrent miscarriage. Although some studies have reported statistically significant associations between this syndrome and certain HLA-DR antigens--especially the -DR1 and -DR3 antigens--other studies have been unable to demonstrate such associations. For the present meta-analysis, 18 cross-sectional or case-control studies (published or unpublished) reporting on frequencies of HLA-DR1 and -DR3 antigens among Caucasian women with unexplained repeated miscarriage were identified by searching literature databases (MEDLINE and EMBASE), reading the references of identified studies, and by contacting researchers within the field. The studies comprised a total of 1508 patients. The methodological quality of most of the studies was low, especially because of small numbers of patients and because patients with only two miscarriages were included in many studies; this is defined as repeated miscarriage. The odds ratios of repeated miscarriage for the HLA-DR1 and -DR3 antigens were calculated for the individual studies and subsequently the pooled odds ratios for the studies were calculated. The combined odds ratio for HLA-DR1 was 1.29 [95% confidence interval (CI) = 1.05-1.58] (17 studies) which is statistically significant (P <0.05). The combined odds ratio for HLA-DR3 was 1.00 (95% CI 0.80-1.24) (18 studies), which is not significant. The results of the meta-analysis suggest that the HLA-DR antigen DR1 is associated with an increased susceptibility to unexplained repeated miscarriage.

Primary structure of ovine fibroblast growth factor-1 deduced by protein and cDNA analysis

The amino acid sequence of full-length ovine fibroblast growth factor-1 (FGF-1) was determined by a combination of protein and cDNA sequencing. FGF-1 cDNA analysis indicated that ovine kidney cells express mRNAs encoding both full-length FGF-1 and a truncated FGF-1 variant. An overall comparison of the ovine FGF-1 primary sequence to the eight species studied to date revealed a high degree of conservation, with ovine FGF-1 sharing 90 and 95% sequence identity with human FGF-1 and bovine FGF-1, respectively. Additionally, the FGF-1 proteins from the various species have conserved cysteine residues at positions 30 and 97 and contain acetylated amino-terminal alanine residues. Mass spectrometry analysis confirmed that the blocking group of ovine FGF-1 is also consistent with that of an acetyl-moiety. In contrast to the other FGF-1 proteins, the 154 residue primary sequence of ovine FGF-1 contains three unique amino acid differences: Arg9, Arg44, and Ile123. Ovine FGF-1, unlike human FGF-1, is a potent mitogenic factor for NIH 3T3 fibroblasts in the absence of heparin. In the presence of exogenous heparin, the mitogenic activity of ovine FGF-1 is potentiated slightly.

Expression of Schistocerca gregaria ion transport peptide (ITP) and its homologue (ITP-L) in a baculovirus/insect cell system

We expressed an N-terminally extended Schistocerca gregaria ion transport peptide (ScgITP) and its homologue (ion transport peptide-like; ITP-L) in insect Sf9 cells using baculovirus expression vectors. Antibodies raised against peptide fragments of ITP and ITP-L were used to detect and characterize the baculovirus expressed peptides (bacITP, bacITP-L). Biological activity of the expressed peptides was assayed using the highly specific bioassay for native ITP, namely the increase in ileal short-circuit current which is a measure of active Cl- transport. BacITP and bacITP-L expression was optimal in Sf9 cells infected at a multiplicity of infection of 1, grown in Grace's medium, and harvested 2-3 days after infection. Western blots showed that bacITP was 2 kDa larger than native or synthetic ITP. This difference was not due to glycosylation and could in part be attributed to post-translational cleavage of the ITP propeptide at a site 11 amino acids upstream of the cleavage site used by S. gregaria to produce native ITP. BacITP stimulated ileal short-circuit current but is significantly less active (270-fold) than synthetic ITP (synITP) possibly as a result of the N-terminal extension. Production of bacITP-L permitted us to show that it is not stimulatory in the bioassay but reduces the synITP response in vitro and thus may have some potential for enhancing the effectiveness of biological control agents such as baculoviruses.