Improving gait classification in horses by using inertial measurement unit (IMU) generated data and machine learning.

For centuries humans have been fascinated by the natural beauty of horses in motion and their different gaits. Gait classification (GC) is commonly performed through visual assessment and reliable, automated methods for real-time objective GC in horses are warranted. In this study, we used a full body network of wireless, high sampling-rate sensors combined with machine learning to fully automatically classify gait. Using data from 120 horses of four different domestic breeds, equipped with seven motion sensors, we included 7576 strides from eight different gaits. GC was trained using several machine-learning approaches, both from feature-extracted data and from raw sensor data. Our best GC model achieved 97% accuracy. Our technique facilitated accurate, GC that enables in-depth biomechanical studies and allows for highly accurate phenotyping of gait for genetic research and breeding. Our approach lends itself for potential use in other quadrupedal species without the need for developing gait/animal specific algorithms.

Prolactin suppresses malonyl-CoA concentration in human adipose tissue.

Prolactin is best known for its involvement in lactation, where it regulates mechanisms that supply nutrients for milk production. In individuals with pathological hyperprolactinemia, glucose and fat homeostasis have been reported to be negatively influenced. It is not previously known, however, whether prolactin regulates lipogenesis in human adipose tissue. The aim of this study was to investigate the effect of prolactin on lipogenesis in human adipose tissue in vitro. Prolactin decreased the concentration of malonyl-CoA, the product of the first committed step in lipogenesis, to 77+/-6% compared to control 100+/-5% (p=0.022) in cultured human adipose tissue. In addition, prolactin was found to decrease glucose transporter 4 ( GLUT4) mRNA expression, which may cause decreased glucose uptake. In conclusion, we propose that prolactin decreases lipogenesis in human adipose tissue as a consequence of suppressed malonyl-CoA concentration in parallel with decreased GLUT-4 expression. In the lactating woman, this regulation in adipose tissue may enhance the provision of nutrients for the infant instead of nutrients being stored in adipose tissue. In hyperprolactinemic individuals, a suppressed lipogenesis could contribute to an insulin resistant state with consequences for the health.

Stroke among male professional drivers in Denmark, 1994-2003.

OBJECTIVES: (1) To estimate the relative risk of stroke among various groups of professional drivers; (2) to determine if any excess risk should be attributed to infarction or haemorrhage; (3) to estimate the relative risk ratio for stroke among professional drivers living in Greater Copenhagen compared to those living outside the metropolis. METHODS: A cohort of 6285 bus drivers, 4204 car, taxi, and van drivers, and 25,879 heavy truck and lorry drivers were followed up for hospital admission due to stroke and sub-diagnoses in the period 1994-2003. Using hospital admission for all economically active men as the standard, the standardised hospitalisation ratios (SHR) were calculated, taking age and county into consideration. RESULTS: There was a high SHR for stroke among all groups of professional drivers (SHR = 132; 95% CI 121-141). Among car, taxi, and van drivers the SHR was 157 (95% CI 132-189), among bus drivers it was 139 (95% CI 119-163), and among heavy truck and lorry drivers it was 124 (95% CI 113-136). The excess risk for all groups of professional drivers was highest for cerebrovascular infarction (SHR = 139; 95% CI 124-155) and lowest for non-traumatic intracranial haemorrhage (SHR = 113; 95% CI 96-133). The excess risks for all groups were significantly higher for cerebrovascular infarction than for non-traumatic intracranial haemorrhage (relative risk ratio (RRR) 1.23; 95% CI 1.01-1.51). The RRR of stroke among drivers in the metropolitan area compared to rural areas was 1.13 (95% CI 0.94-1.36). The RRR for stroke among car, taxi, and van drivers compared to drivers of heavy trucks and of lorries was 1.28 (95% CI 1.03-1.57). CONCLUSION: All groups of professional drivers are at increased risk of stroke. The excess risk is more due to cerebral infarctions than to non-traumatic intracranial haemorrhage. The risk of stroke is higher among drivers carrying passengers than among drivers carrying goods.

Regulation of oxidative enzyme activity and eukaryotic elongation factor 2 in human skeletal muscle: influence of gender and exercise.

AIM: To investigate gender-related differences in the responses of oxidative enzymes and eukaryotic elongation factor-2 (eEF2) to exercise. METHODS: The influence of exercise (90 min, 60%VO(2peak)) on citrate synthase (CS) and beta-hydroxyacyl-CoA dehydrogenase (HAD) activity and mRNA content, together with eEF2 expression and phosphorylation at rest, were assessed in skeletal muscle of untrained (UT) and endurance trained (ET) females and males. RESULTS: Citrate synthase and HAD mRNA were higher in females than in males (27% and 48%, respectively, P < 0.05) whereas CS and HAD activity did not differ between females and males (NS). In females only, CS activity was enhanced (P < 0.05) by 90 min exercise. Resting CS mRNA content did not differ between UT and ET but, nevertheless, CS activity was 56% higher in ET than in UT volunteers (P < 0.001). HAD mRNA and activity were not influenced by training status (NS). In UT, CS mRNA was enhanced 37% (P < 0.05) by exercise whereas exercise did not change CS mRNA in ET (NS). eEF2 expression was 31% higher (P < 0.05) and eEF2 Thr56 phosphorylation (which leads to translation inhibition) was 24% lower (P < 0.05) in females than in males. eEF2 expression and phosphorylation were unaffected by training status (NS). CONCLUSION: Basal transcriptional, translational, and/or post-translational control of CS and HAD seems to be gender-dependent. Also, gender differences in translation and/or post-translational protein modification of CS occur during exercise. Accordingly, the potential for peptide-chain elongation, based on eEF2 expression and phosphorylation, appears to be higher in females than in males.

Studies of plasma membrane fatty acid-binding protein and other lipid-binding proteins in human skeletal muscle.

The first putative fatty acid transporter identified was plasma membrane fatty acid-binding protein (FABPpm). Later it was demonstrated that this protein is identical to the mitochondrial isoform of the enzyme aspartate aminotransferase. In recent years data from several cell types have emerged, indicating that FABPpm plays a role in the transport of long-chain saturated and unsaturated fatty acids. In the limited number of studies in human skeletal muscle it has been demonstrated that dietary composition and exercise training can influence the content of FABPpm. Ingestion of a fat-rich diet induces an increase in FABPpm protein content in human skeletal muscle in contrast to the decrease seen during consumption of a carbohydrate-rich diet. A similar effect of a fat-rich diet is also observed for cytosolic fatty acid-binding protein and fatty acid translocase/CD36 protein expression. Exercise training up regulates FABPpm protein content in skeletal muscle, but only in male subjects; no significant differences were observed in muscle FABPpm content in a cross-sectional study of female volunteers of varying training status, even though muscle FABPpm content did not depend on gender in the untrained state. A higher utilization of plasma long-chain fatty acids during exercise in males compared with females could explain the gender-dependent influence of exercise training on FABPpm. The mechanisms involved in the regulation of the function and expression of FABPpm protein remain to be clarified.

Utilization of long-chain fatty acids in human skeletal muscle during exercise.

Long-chain fatty acids (LCFA) are important sources of energy in contracting skeletal muscle: during the course of endurance exercise the contribution of LCFA in energy metabolism increases whereas when the intensity of exercise increases, the energy need is covered more and more by carbohydrates. Although this has been known for nearly 100 years, the mechanisms controlling fatty acid uptake and oxidation during various exercise modes are still not completely elucidated. Besides passive diffusion, data suggest that both membrane-associated and cytosolic fatty acid binding proteins are involved in the uptake of LCFA into skeletal muscle. However, data from human studies suggest that the regulation of fatty acid utilization in skeletal muscle during exercise lies mainly within the entrance into the mitochondria or metabolism within the mitochondria. Although possible compartmentalization within the cell makes definitive conclusions difficult, available evidence suggests that changes in malonyl CoA concentration in muscle do not play a major regulatory role in controlling LCFA oxidation during exercise in man. In contrast, it is suggested that the availability of free carnitine may play a major regulatory role in oxidation of LCFA during exercise.

[Mortality during the first six years after cholecystectomy. A review of all cholecystectomies in women in Denmark during 1977-1981]. / Dødeligheden i de første seks år efter kolecystektomi. Opgørelse af samtlige kolecystektomier blandt kvinder i Danmark i perioden 1977-1981.

It has been a prevailing assumption that cholecystectomy patients by and large follow a pattern of survival similar to that of the normal population. This paper presents a population-based study of the long-term survival after cholecystectomy in order to reassess this assumption. Based on data available in the Danish National Hospital Register, the records of all Danish women who were operated between 1977 and 1981 were examined and studied up to six years subsequent to surgery. Cholecystectomy patients who were free of diagnosed cancer and who had no major co-surgery (n = 11,123) were compared to both hysterectomy patients and a sample of the female population. Adjusting for age and other covariates, patients with psychiatric hospital admissions prior to surgery experienced a threefold risk of dying within six years after surgery. Patients with prior somatic admissions and patient with acute admissions had a relative risk (RR) of about 1.5. Cholecystectomy patients had a significantly increased mortality when compared to hysterectomy patients, RR = 1.3 (1.1-1.6), and to the population sample. Heart diseases and cancer occurred significantly more often as causes of death among cholecystectomy patients when compared to hysterectomy patients, but our data suggest that the occurrence of many other causes of death may be increased among cholecystectomy patients as well. The authors concluded that cholecystectomy patients are subject to relatively higher levels of mortality than previously assumed in parts of the literature. Furthermore, the increase seems to be attributable to a multitude of causes of death. The most likely explanation of the excess mortality among cholecystectomy patients is that gallbladder patients are relatively fragile. Indeed, with this vulnerable group of patients the potential trauma of the surgical intervention itself needs careful consideration.

Survival until 6 years after cholecystectomy: female population of Denmark, 1977-1983.

It has been a prevailing assumption that cholecystectomy patients by and large follow a pattern of survival similar to that of the normal population. This paper presents a population-based study of the long-term survival after cholecystectomy in order to reassess this assumption. Based on data available in the Danish National Hospital Register the records of all Danish women who were operated between 1977 and 1981 were examined and studied up to 6 years subsequent to surgery. Cholecystectomy patients who were free of diagnosed cancer and who had no major co-surgery (n = 11,123) were compared to both hysterectomy patients and a sample of the female population. Adjusting for age and other covariates, patients with psychiatric hospital admissions prior to surgery experienced a threefold risk of dying within 6 years after surgery. Patients with prior somatic admissions and patient with acute admissions had a relative risk (RR) of about 1.5. Cholecystectomy patients had a significantly increased mortality when compared to hysterectomy patients, RR = 1.3 (1.1-1.6), and to the population sample. Heart diseases and cancer occurred significantly more often as causes of death among cholecystectomy patients when compared to hysterectomy patients, but our data suggest that the occurrence of many other causes of death may be increased among cholecystectomy patients as well. The authors concluded that cholecystectomy patients are subject to relatively higher levels of mortality than previously assumed in parts of the literature. Furthermore, the increase seems to be attributable to a multitude of causes of death. The most likely explanation of the excess mortality among cholecystectomy patients is that gallbladder patients are relatively fragile.(ABSTRACT TRUNCATED AT 250 WORDS)

[Postoperative mortality after cholecystectomy. A survey of all cholecystectomies among women in 1977-1981]. / Postoperativ mortalitet ved kolecystektomi. Opgørelse vedrørende samtlige kolecystektomier blandt kvinder i Danmark i perioden 1977-1981.

This paper assesses the risk of dying within thirty days of admission among 13,854 women who had a cholecystectomy performed as the principal operation during the period 1977-81. The overall crude mortality rate was 1.2%. Women who had a simple elective cholecystectomy performed had a mortality rate (0.2%) similar to women who had a simple hysterectomy, but significantly higher than in the general female population. High age, acute admission, admission to hospital in the three months prior to the index admission, the number of discharge diagnoses, and the geographical region were significantly associated with increased mortality. The higher mortality associated with exploration of the common bile duct disappeared when number of discharge diagnoses was taken into account. As regards early mortality, it is concluded that simple elective cholecystectomy is a safe procedure before the age of 50-60 years. Exploration of the common bile duct may not be as important an independent factor as previous assumed.

Complications after hysterectomy. A Danish population based study 1978-1983.

We studied complications after hysterectomy among all women in the Danish population who had a simple hysterectomy in the period 1978-81 based on data obtained from the Danish National Hospital Registry. Among patients, with neither diagnosed cancer nor major co-surgery (n = 23,386), we identified all the complications which occurred during hospital admission from the time of surgery up to six years from that point. Within 30 days of hysterectomy 2.6% of the patients had been diagnosed in hospitals as having complications according to our definition. The corresponding figures at 90 days and two years after the operation were 3.7% and 9.4%. The most frequently observed complications were post operative wound infections and bleeding, each affecting about 2% of all operated women. Logistic regression and Cox regression were used to identify prognostic indicators of readmission with complications. The probability of readmission with complications within six years after hysterectomy was estimated at 8% among low risk patients. The most pronounced increase in risk of readmission with complication occurred among women who had been admitted to psychiatric or somatic hospitals 0-12 months before they had their uterus removed (OR in the range 1.59 to 1.83). We discuss the prevailing difficulties of comparing observational evidence from different clinical settings reported in the literature, and emphasize the importance of developing a coordinated international strategy for non-experimental assessment of medical technology.

Early postoperative mortality following cholecystectomy in the entire female population of Denmark, 1977-1981.

This paper assesses the risk of dying within 30 days of admission among 13,854 women who had a cholecystectomy performed as the principal operation from 1977 to 1981. The overall crude mortality rate was 1.2%. Women who had a simple elective cholecystectomy performed had a mortality rate similar to women who had a simple hysterectomy. The mortality was significantly higher than in the general female population (p less than 0.05). Increased age, acute admission, admissions to hospital within 3 months prior to the index admission, the number of discharge diagnoses, and the geographical region were significantly associated with increased mortality. Exploration of the common bile duct was associated with higher mortality in the bivariate analysis, but the association disappeared when the number of discharge diagnoses was taken into account. Type of hospital and the population based cholecystectomy rate of the patient's residential area was not associated with mortality. As regards early mortality, it is concluded that simple elective cholecystectomy is a safe procedure before the age of 50 to 60 years. Acute admissions and more than one diagnosis at discharge were associated with an increased mortality, whereas exploration of the common bile duct may not be as important an independent factor as previously assumed.

Early postoperative mortality following hysterectomy. A Danish population based study, 1977-1981.

The main objective of this cohort study was to analyse the early postoperative mortality after 'simple' hysterectomy for benign indications and to compare it with that of a randomly selected reference group of women matched for age. Registry data covering the entire Danish female population were used. Included in the study were all patients operated in the period 1977-1981. Patients were only included if no cancer was diagnosed and if no major co-surgery was performed (29,192 patients). Cancer patients were also excluded in the reference group (16,182 women). Mortality was studied according to characteristics of patients, their residential area, the surgical approach and operating hospital. Overall 47 patients died within 30 days of admission for hysterectomy (overall mortality 16.1 per 10,000). Only seven deaths were expected on the basis of the population sample, and adjusted for age, the relative risk (RR) for hysterectomy patients was 6.38 (95% CI 4.33-9.39). Early postoperative mortality increased with age, and the risk was elevated among emergency patients (RR = 3.22; 1.72-6.04). Patients with more than one diagnosis at discharge (RR = 4.53; 2.12-9.70) were at high risk, but early postoperative mortality was independent of surgical approach. Causes of death are discussed. Compared to the general population, patients who undergo 'simple' hysterectomy are faced with a sixfold risk of dying within 30 days, but a complete assessment of the risks and benefits of hysterectomy requires prospective studies of survival and morbidity, including quality of life for longer periods of time following operations.

Prostatectomy in Denmark. Regional variation and the diffusion of medical technology 1977-1985.

In many countries prostatectomy is one of the most common surgical operations in elderly men. We used administrative data for the entire male population of Denmark to study temporal and regional variations in the use of prostatectomy from 1977 to 1985. The total annual number of prostatectomies increased by 43% during the period, when the transurethral procedure (TURP) gradually replaced traditional open surgery. TURP accounted for 56% of all operations in 1977 but increased its share to 92% in 1985. Substantial regional variations occurred with index values for prostatectomy in 72 recruitment areas ranging from 0.56 to 1.62 (SCV x 100 = 5.3). The amount of variation decreased during the process of technology diffusion, but remained at a relatively high level (as in other countries) even after the process had been completed (SCV x 100 = 5.1).

Elevated mortality following transurethral resection of the prostate for benign hypertrophy! But why?

This paper reevaluates the recently reported excess mortality following transurethral resection of the prostate (TURP) for benign hypertrophy as compared with traditional open resection (OPEN). We studied survival through linkage of hospital discharge data with mortality data for the entire male population of Denmark (1977-85). For a maximum of 10.5 years 38,067 prostatectomy patients were followed. Adjusting for age and health status before surgery, TURP patients were subject to significantly higher levels of mortality than OPEN patients (RR = 1.19, 95% confidence interval (1.15-1.24). The extent to which this difference is attributable to the surgical intervention itself remains an open question. The two groups of patients are quite different with regard to age and preoperative health status, and available data may not be sufficient to control such differences through statistical analysis. On the other hand, the difference in mortality persisted over calendar time, even during periods when the pattern of utilization for the two procedures changed significantly (constant RR = 1.19, adjusting for age and comorbidity). The most important causes of death among Danish TURP patients differ from the causes suggested on the basis of previously reported Canadian data. The current evidence is thus ambiguous with regard to hypothetical biologic mechanisms behind the excess mortality over TURP patients. Further investigations are needed to evaluate the safety and effectiveness of prostate surgery.

[Self-reported pattern of illness and hospitalization during pregnancy. Results from a nation-wide questionnaire study]. / Selvrapporteret sygdoms- og indlaeggelsesmønster under graviditet. Resultater fra en landsdaekkende spørgeskemaundersøgelse.

In a representative questionnaire investigation covering all of Denmark, 3,152 women provided information about their health during a recent pregnancy. Of these, 1,411 (45%) had been ill or had experienced severe complaints related to the pregnancy and 625 (20%) had been hospitalized during pregnancy. The average duration of hospitalization was two weeks with great variations in the various conditions. Women with multiple pregnancies were hospitalized for an average of six weeks. Increased incidence of hypertension and placental insufficiency were found among women over the age of 35 years whereas preeclampsia was most common among primigravidae. Women who had previously had a spontaneous abortion had an increased frequency of haemorrhage, threatened abortion and threatened premature delivery. Previous infertility was not associated with increased occurrence of complications of pregnancy-related morbidity were observed between women who had work outside the home and women who worked in their homes. Women with work outside the home who reported illness or severe pregnancy-related symptoms had an average period of sick-leave of six weeks for health reasons. The most prolonged periods of sick-leave were in cases of threatened abortion, threatened premature delivery and multiple pregnancies. The right to take leave with pay or maintenance allowance prior to the expected date of delivery is not utilized to any great extent more by women with illness during pregnancy. On the other hand, women with long educations utilized this right to a greater extent than unskilled women, who had, on the other hand increased leave on account of health reasons.

[Regional differences in the use of cholecystectomy in Denmark during the period 1977-1985]. / Regionale variationer i anvendelsen af kolecystektomi i Danmark 1977-85.

In a register-based study of all cholecystectomized patients in Denmark during the period from 1977-85 (37,048 patients) an account is given of the regional variations observed in connection with the intervention. The cholecystectomy operation is sub-divided into four types of operation dependent on whether the intervention is merely a matter of cholecystectomy or it involves the choledocus, the duodenum, the small intestine or other organs. The variation analysis is based on a division of the country into 75 areas, each primarily served by a single hospital. The method highly reflects the differences in clinical treatment strategies. The summarized rate of cholecystectomy for this period of time was 8.2 per 10,000 persons. In areas with the highest and the lowest rates of operation the figures were 12.3 per 10,000 and 5.1 per 10,000, respectively. In 18 areas, the rates of operation were significantly higher than average and in 18 other areas significantly higher than average and in 18 other areas significantly below average. SCV-score (X100) 2.19. There is no systematic correlation between the degree of specialisation in the operating department and the frequency in employing the operation. Areas with an operation index significantly above average had the same rate of more complicated operations than simple cholecystectomy as the other areas. Possible causes of national as well as international variations in the use of cholecystectomy are discussed, and the need for a radical evaluation of this kind of treatment is emphasized.