Hydrocephalus shunt therapy: current titanium shunt valve implants obstructed by internal tissue proliferations identified as extracellular matrix membranes.

PURPOSE: Shunt valves, required for treatment of hydrocephalus, demand for high performance rates and lifelong excellent function. To overcome problems with traditional silicone materials, adjustable and gravity-adapted titanium valves were developed. Even modern shunt valve systems are still subject to occlusion. The aim of the present study was to investigate dysfunctional silicone and titanium valves for presence of cellular and proteinous materials inside the housings by means of histopathology. METHODS: A total of 19 explanted shunt valves from children between 2 and 182 months of age were investigated following dysfunction. After fixation in formalin and embedding in hard resin, slices were ground to a thickness of 5-30 µ. Besides standard histology, immunohistochemistry was performed using antibodies with markers for microglia, astrocytes, platelets, monocytes, and the proteins laminin, fibronectin, and collagen IV. RESULTS: Traces, layers, and plaques could be demonstrated in every investigated silicone or titanium valve with an implantation time of more than 6 days. Most of the tissue was found adjacent to silicone and titanium surfaces of the inner housing, the adjustment rotor, and ball-in-cone core. Markers for micro and astroglia stained positive in 40-60% of the specimen, mostly demonstrating a proteinous layer positive for laminin (80%), fibronectin (30%), and collagen IV (30%). CONCLUSIONS: Tissue reactions with formation of cellular and proteinous matrix components are common in obstructed silicone and titanium shunt valves. The tissue mimics astrocytic repair mechanisms genuine for basilar membrane matrix. The knowledge of these typical arachnoid patterns of colonization is a prerequisite for developing future shunt devices.

On the prediction of SAV transmission among Norwegian aquaculture sites.

Pancreas Disease (PD) is a viral disease that affects Atlantic salmon (Salmo salar) in Norwegian, Scottish and Irish aquaculture. It is caused by salmonid alphavirus (SAV) and represents a significant problem in salmonid farming. Infection with SAV leads to reduced growth, mortality, product downgrading, and has a significant financial impact for the farms. The overall aim of this study is to evaluate the effect of various factors on the transmission of SAV and to create a predictive model capable of providing an early warning system for salmon farms within the Norwegian waters. Using a combination of publicly available databases, specifically BarentsWatch, and privately held PCR analyses a feature set consisting of 11 unique features was created based on the input parameters of the databases. An ensemble model was developed based on this feature set using XG-Boost, Ada-Boost, Random Forest and a Multilayer Perceptron. It was possible to successfully predict SAV transmission with 94.4% accuracy. Moreover, it was possible to predict SAV transmission 8 weeks in advance of a 'PD registration' at individual aquaculture salmon farming sites. Important predictors included well boat movement, environmental factors, proximity to sites with a 'PD registration' and seasonality.

Erratum to "Use of a real-time location system to detect cows in distinct functional areas within a barn" (JDS Commun. 2:217-222).

[This corrects the article DOI: 10.3168/jdsc.2020-0050.].

Use of a real-time location system to detect cows in distinct functional areas within a barn.

Automated sensor-based monitoring of cows has become an important tool in herd management to improve or maintain animal health and welfare. Location systems offer the ability to locate animals within the barn for, for example, artificial insemination. Furthermore, they have the potential to measure the time cows spend in important areas of the barn, which might indicate need for improvement in the management of the herd or individuals. In this study, we tested the sensor-based real-time location system (RTLS) Smartbow (SB, Smartbow GmbH) under field conditions. The objectives of this study were (1) to determine the accuracy of the system to predict the location of the cow and the agreement between visual observations and RTLS observations for the total time spent by cows in relevant areas of the barn and (2) to compare the performance of 2 different algorithms (Alg1 and Alg2) for cow location. The study was conducted on a commercial Austrian dairy farm. In total, 35 lactating cows were video recorded for 3 consecutive days. From these recordings, approximately 1 h was selected randomly each day for every cow (3 d × 35 cows). Simultaneously, location data were collected and classified by the RTLS system as dedicated to the alley, feed bunk, or cubicle on a 1-min resolution. A total of 6,030 paired observations were derived from visual observations (VO) and the RTLS and used for the final data analysis. Substantial agreement of categorical data between VO and SB was obtained by Cohen's kappa for both algorithms (Alg1 = 0.76 and Alg2 = 0.78). Similar results were achieved by both algorithms throughout the study, with a slight improvement for Alg2. The ability of the system to locate the cows in the predefined areas was assessed, and the results from Alg2 showed sensitivity, specificity, and positive predictive value of alley (74.0, 91.2, and 76.9%), feed bunk (93.5, 86.2, and 89.1%), and cubicle (90.5, 83.3, and 95.4%) and an overall accuracy of 87.6%.The correlation coefficient (r) between VO and SB for the total time cows spent (within 1 h) in the predefined areas was good to strong (r = 0.82, 0.98, and 0.92 for alley, feed bunk, and cubicle, respectively). These results show the potential of the system to automatically assess total time spent by cows in important areas of the barn for indoor settings. Future studies should focus on evaluating 24-h periods to assess time budgets and to combine technologies such as accelerometers and location systems to improve the performance of behavior prediction in dairy cows.

The mechanism of the natriuresis of fasting.

This study tests the hypothesis than obligatory cation coverage of metabolicaly generated anions is the mechanism for the sodium diuresis of fasting. Nine obese female subjects were equilibrated on a constant sodium and caloric intake and then fasted while sodium intake was maintianed. Particular activity schedule during fasting as during control. Consecutive 3-h increases in urinary sodium , ammonium, and potassium excretion during fasting were matched against simultaneously determined increases in organic acid anions (OAS) and H2PO4 minus, which would exist in combination with the cations. The changes were significantly correlated (r equals 0.891, P less than 0.001) in the relationship y equals 0.73x plus 19 where y equals increases in organic acid salts plus H2POJ minus and x equals increases in cations. As ammonium excretion rose, sodium conservation occurred with ammonium replacing sodium at the major urinary cation. Corollaries to the hypothesis were also found to be true. They were: (a) Increases in ammonium excretion lagged considerably behind increases in OAS plus H2PO4 minus during the diuretic phase making sodium coverage necessary. (b) Sodium loss was much greater than chloride although chloride balance was minimally negative. (c) After refeeding with glucose, sodium excretion promptly decreased and appeared best correlated with simultaneous decreases in OAS. Ammonium excretion also fell but much less than sodium. The data support the hypothesis that obligatory cation coverage of metabolically generated aniuns is a major mechanism responsible for the sodium diuresis of fasting.

Effect of a novel dietary supplement on skin aging in post-menopausal women.

OBJECTIVE: The aim of the present study was to quantify the effects on skin in post-menopausal women of a novel dietary supplement (Imedeen Prime Renewal) that contained soy extract, fish protein polysaccharides, extracts from white tea, grape seed and tomato, vitamins C and E as well as zinc and chamomile extract. DESIGN: The study was a 6-month double blind, placebo controlled, randomized study on healthy post-menopausal females. SETTING: The study was performed at a commercial Contract Research Organisation (TJ Stephens & Associates Inc., TX, USA). INTERVENTIONS: Two tablets of Imedeen Prime Renewal or placebo were given twice daily for 6 months. SUBJECTS: Thirty-eight (active group) and 42 (placebo group) subjects completed the study out of 100. RESULTS: Clinical grading showed that the active group had a significantly greater improvement (P < 0.05) compared to placebo for the face after 6 months treatment for: forehead, periocular and perioral wrinkles, mottled pigmentation, laxity, sagging, under eye dark circles and overall apperance; skin on the décolletage after 2, 3 and 6 months treatment and skin on the hand after 3 and 6 months treatment. Photo evaluation showed that the active group had a significantly greater improvement (P < 0.05) on the face after 3 and 6 months for several parameters. Ultrasound measurements showed that the active group had a significantly greater improvement (P < 0.0001) for density measurements after 6 months treatment. CONCLUSION: In summary, this novel dietary supplement, Imedeen Prime Renewal, provides improved condition, structure and firmness of the skin in post-menopausal women after 6 months.

Double-helix coil for occlusion of large patent ductus arteriosus: evaluation in a chronic lamb model.

OBJECTIVES: We sought to evaluate the efficacy and tissue reaction of a new miniature interventional device for occlusion of large patent ductus arteriosus (PDA) in a neonatal lamb model. BACKGROUND: A variety of devices are used to close PDAs by interventional measures. Spring coils found to have a high cumulative occlusion rate have thus far been limited to smaller PDAs because of the physical limitation of grip forces. METHODS: Memory-shaped double-cone stainless steel coils with enhanced stiffness of the outer rings by a double-helix configuration were mounted on a titanium/nickel core wire. A snap-in mechanism attaches the coil to the delivery wire, allowing intravascular coil retrieval and repositioning. The system was placed through a 4F or 5F Teflon catheter. A chronic lamb model (n = 8) of PDA (>5 mm) was used in which ductus patency was secured by a protocol of repetitive angioplasty procedures. The animals were killed after 1 to 181 days, and the ductal region was examined by inspection as well as by light and electron microscopy. RESULTS: Placement of the coils within the PDA was possible in all lambs. Before final detachment, the coils were retrieved or repositioned, or both, up to 12 times. In all but one animal the ductus was closed within 6 days after the procedure. The coils caused no infections or aortic and pulmonary artery obstruction. Histologic and electron microscopic studies revealed endothelial coverage of the implants but no foreign body reaction or local or systemic inflammation or erosion of the implant. CONCLUSIONS: The device effectively closed large PDAs in our model and may overcome the previous limitations of coils. Clinical trials are indicated.

Plasma glucose turnover and oxidation during hemodialysis: nutritional effect of dialysis fluid.

Mass transfer of glucose from dialysis fluid into patients is a source of energy and a form of nutrition during hemodialysis. The effect of glucose mass transfer on endogenous glucose metabolism and the overall nutritional importance of glucose transfer is not known. Rates of plasma glucose turnover and oxidation were determined by radioisotope-dilution techniques in patients with chronic renal failure (CRF) in the basal state, during hemodialysis, and during the infusion of glucose at a rate similar to the mass transfer rate (Mt: 6.6 +/- 0.7 mumol.min-1.kg-1). Rates of plasma glucose turnover (11.8 +/- 0.8 mumol.min-1.kg-1) and oxidation (4.0 +/- 0.4 mumol.min-1.kg-1) and contribution of glucose oxidation to the metabolic rate were similar to those of control subjects both in the basal state and during glucose infusion. During hemodialysis with acetate and glucose, the plasma glucose turnover rate was similar to that in the basal state, but the energy from glucose oxidation was less (P < or = 0.02) even though energy expenditure was increased by 21%. Immediate oxidation of plasma glucose and acetate accounted for 65% of the patients' energy expenditure. Energy (1172 kJ) from acetate Mt and glucose Mt surpassed the patients' energy requirements, offsetting the utilization of endogenous fuels, a sparing effect equivalent to 31 g fat or 70 g carbohydrate. Rates of plasma glucose turnover and oxidation during bicarbonate-glucose and glucose-free acetate hemodialysis were similar to that during acetate-glucose hemodialysis. However, without glucose or acetate in the bath fluid, a deficit as much as 669 kJ must be met by the oxidation of endogenous fuels. Addition of organic nutrients that supply energy to dialysis fluids may over time be a beneficial supplemental treatment for the malnutrition and body wasting commonly observed in CRF.

Plasma pyridoxal-5'-phosphate levels and clinical correlations in chronic hemodialysis patients.

Plasma pyridoxal-5'-phosphate (PLP) was measured by a specific method in 45 stable, chronic hemodialysis patients and 13 normal adults. Despite oral pyridoxine supplements (1 to 5 mg/day) a majority (64%) of patients had low levels. The difference between normals (8.5 +/- 3.7 ng/ml) and dialysis patients (3.6 +/- 3.6 ng/ml) was significant at P less than 0.01. Plasma PLP appeared to decrease with increasing duration of time on dialysis therapy. In vivo clearance studies as well as pre- and postdialysis plasma levels indicated that PLP was not removed by the dialyzer. Mean plasma PLP levels were normal in patients with stable motor nerve conduction velocity and a low transfusion requirement and low in those with decreasing motor nerve conduction velocity or a high transfusion requirement but the difference between the means in each group was not statistically significant. High oral doses of pyridoxine (100 to 200 mg/day) but not low doses (1 to 5 mg/day) restored PLP levels to normal in a majority of patients after 2 weeks.

Influence of temperature during cardiopulmonary bypass on leukocyte activation, cytokine balance, and post-operative organ damage.

This study examined the hypothesis that core temperature (T(o)) during cardiopulmonary bypass (CPB) influences the perioperative systemic inflammatory response and post-operative organ damage. Twenty-four pigs were assigned to a T(o) regimen during CPB: normothermia (T(o) 37 degrees C; n = 8), moderate hypothermia (T(o) 28 degrees C; n = 8), or deep hypothermia (T(o) 20 degrees C; n = 8). Perioperative leukocyte activation, endotoxin release, and production of tumor necrosis factor-alpha (TNFalpha) and interleukin-10 (IL10) were examined with regard to post-operative organ damage, which was scored at histological examination of tissue probes of heart, lungs, liver, kidney, and ileum, taken 6 h after CPB. Total blood leukocyte count and TNFalpha plasma levels during CPB were significantly lower and IL10 levels were significantly higher in the moderate hypothermic group than in both other groups. Elastase activity, leukotriene B4-, and endotoxin levels were not affected by T(o) regimen. Moderate hypothermia was associated with the lowest histological organ damage score and normothermia with the highest. In all animals organ damage score for heart, lungs, and kidneys correlated significantly with TNFalpha levels at the end of CPB. Our data demonstrate a clear relationship between TNFalpha production during cardiac operations and post-operative multiple-organ damage. Moderate hypothermia, by stimulating IL10 synthesis and suppressing TNFalpha production during CPB, might provide organ protection.

Coil on the loop and selectively enhanced stiffness for improved control: feasibility study in the neonatal ovine model of the large patent ductus arteriosus.

RATIONALE AND OBJECTIVES: Several devices have been suggested and tested for interventional closure of the persistent ductus arteriosus. Coils were found effective only in small ducts due to their lack of maneuverability and physical limitation of grip forces leading to risk of embolization. The authors evaluated the feasibility to place single coils with selectively enhanced stiffness into high shunting ductus arteriosus, the coils being deployed and controlled through a veno-arterial loop in a bovine model. METHODS: "Double-cone" shaped, stainless steel coils with enhanced stiffness of the outer rings were mounted on either end on a nitinol core wire. A snap-in mechanism attaches the coil to this delivery wire and is freed by a pusher system of coiled steel wire that is advanced over the core wire. Forming a veno-arterial loop across the patent ductus allows for repositioning into the pulmonary artery or aortic catheter. A chronic lamb model of large patent ductus arteriosus (PDAs) (> or = 9 mm) was used in which ductus patency was secured by a protocol of repetitive angioplasties. Different systems (n = 10) were placed having retrieved the previous coil by a snare after definitive release. RESULTS: Placement of coils was possible in all 10 attempts. The coils were pulled back into the catheters between five and eight times before definitive release. CONCLUSIONS: The device allows controlled placement of single coils in our model of large PDAs and may lead the way to overcome previous limitations of coils. Clinical trials are warranted.

Retrievable patent ductus arteriosus plug for interventional, transvenous occlusion of the patent ductus arteriosus. Evaluation in lambs and preliminary clinical results.

RATIONALE AND OBJECTIVES: The clinically most widely used devices (Porstmann-plug, Rashkind-umbrella, Botallooccluder) have inherent specific limitations (eg, transarterial approach, residual shunts, limited retrieval). The authors assess practicability, efficacy, and tissue reaction of the new retrievable transvenous plug device for the occlusion of the persistent patent ductus arteriosus (PDA). METHODS: A foam plug (polyvinyl alcohol) is mounted on a titanium core pin where, at both ends, small legs (titanium nickel alloy) with titanium heads are anchored, to ensure safe fixation in the ductus. The device is introduced transvenously through a long sheath (Mullins sheath) and held by a modified biopsy forceps allowing complete retrieval until final release. A common lamb model of large PDAs (n = 11) was used to test for practicability and the histomorphologic outcome. Clinical results were obtained from a consecutive series of 16 patients (aged 13 to 71 years). RESULTS: In all lambs, placement of the plug within the PDA was possible. Histopathology (follow-up 10 to 215 days; mean 112 days) revealed an adequate ingrowing of the device and no pathologic foreign body reaction. The diameter of the human PDAs ranged from 3 to 7 mm (mean 5 mm). The size of the sheath used for introducing the plug (diameter 8 to 16 mm) ranged from 8 to 16 French. Fourteen of 16 PDAs were closed immediately after or on day 1 after implantation, 1 was closed after the 12-month follow-up, and 1 needed an additional plug after 30 months for definitive closure. CONCLUSIONS: The device demonstrated practicability and biocompatibility in our experimental lamb model and effectively closed the PDA in a consecutive series of 16 patients. A greater number of patients and a longer follow-up period are necessary for the definitive clinical assessment of the new device.

Maternal serum alpha-fetoprotein screening after chorionic villus sampling.

To evaluate whether maternal serum alpha-fetoprotein (MSAFP) concentrations at 15-18 weeks' gestation are influenced by chorionic villus sampling performed three to ten weeks earlier, MSAFP levels were determined for 417 postchorionic villus sampling patients and 967 control subjects without previous chorionic villus sampling. Statistical comparison of the medians, distributions, and proportions above defined multiples of the median demonstrated no significant difference between the two populations. These results indicate that MSAFP screening in postchorionic villus sampling patients should be reliable and that values may be interpreted using criteria similar to those used for the general population.

Acetate and energy metabolism during hemodialysis.

The oxidation of acetate infused in acetate infused in large quantities during acetate dialysis should provide considerable energy for the hemodialysis patient. Previous attempts to measure acetate oxidation rate and thus energy yield by measuring bicarbonate generation rate are flawed because bicarbonate generation occurs by equimolar proton consumption when acetate is activated to acetyl Co-A but before acetyl Co-A has entered the Krebs cycle. Besides the Krebs cycle, acetyl Co-A could enter many other nonoxidative pathways. By using the primed continuous infusion radioisotope (1-14C acetate) dilution technique of Steele, in conjunction with indirect calorimetry, we obtained direct measurements of acetate turnover and immediate oxidation rates and energy yield in 7 stable hemodialysis patients. Commercial dialysate contained glucose (12.4 mmoles/liter), acetate (38 mmoles/liter), plus routine electrolytes. Acetate turnover was 57.2 +/- 2.9 mumoles/min X kg. Of the acetate entering the body, 31.6 +/- 3.8 mumoles/min X kg were immediately oxidized to carbon dioxide and water, which accounted for 54.4 +/- 5.2% of the turnover rate. The amount that entered the blood was 869 mmoles, and 472 mmoles (54.4%) were oxidized; 138 mmoles (15.8%) made up the steady-state pool, and 258 mmoles were directed into nonoxidative pathways (29.7%). During dialysis, 40.3 +/- 4.8% of the carbon dioxide output or metabolic rate was accounted for by acetate oxidation. Thus, acetate emerged as the major contributor to energy production, supplying up to 65% of the total caloric needs during dialysis. The RQ calculated from the lung carbon dioxide excretion was 0.74 +/- 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)

Time course of cranial ultrasound abnormalities after arterial switch operation in neonates.

BACKGROUND: The object of this study was to investigate the time course and fate of abnormal findings in cranial ultrasound after performing an arterial switch operation in neonates with transposition of the great arteries, and to analyze the relationship to cerebral cell damage. METHODS: Cranial ultrasound was performed prospectively in 35 neonates with transposition of the great arteries before the operation as well as 4 hours, 1, 2, and 3 days, and 1 and 2 weeks postoperatively. Blood levels of neuron-specific enolase, a marker of cerebral cell damage, were determined before, during, and 4 and 24 hours postoperatively. RESULTS: In 17 of 35 neonates (49%), early postoperative cranial ultrasound revealed abnormalities indistinguishable from intraventricular hemorrhage. In 11 neonates findings were transient and were normalized 2 weeks postoperatively, whereas in the remaining 6 neonates there was evidence of resolving hemorrhage. In all neonates there was a rise in neuron-specific enolase blood concentrations during and 4 hours after extracorporal circulation without correlation to sonographic findings. CONCLUSIONS: Enhanced echogenicity of the choroid plexus or dilatation of the cerebral ventricular system is a frequent early postoperative finding that may be caused by transient plexus edema rather than intraventricular hemorrhage and is not related to cerebral cell damage.

Neurodevelopmental outcome related to cerebral risk factors in children after neonatal arterial switch operation.

BACKGROUND: Neurodevelopmental outcome after neonatal arterial switch operation for complete transposition of the great arteries is an important topic needing prospective assessment. METHODS: A group of 33 unselected children (3.0 to 4.6 years) operated on as neonates with combined deep hypothermic circulatory arrest and low flow cardiopulmonary bypass and a control group of 32 age-matched healthy children (3.0 to 4.8 years) underwent evaluation of socioeconomic and clinical neurological status and a standardized test comprising all areas of child development. Results of patients were related to those of the control group, to population norms, and to preoperative, perioperative, and postoperative cerebral risk factors. RESULTS: Clinical neurological status was normal in 26 patients (78.8%) and reduced in 7 (21.2%). Complete developmental score and the subscores for motor function, visual perception, learning and memory, cognitive function, language, and socioemotional functions were not different compared to population norms. Compared to the patients, the children of the control group scored higher on tests of complete development, cognition, and language, but also on socioeconomic status. Complete developmental score and the scores for motor, cognitive, and language functions were weakly inversely related to the duration of circulatory arrest, but not to the duration of bypass. Cerebral risk factors such as serum levels of the neuron-specific enolase, perinatal acidosis, perinatal asphyxia, peri- and postoperative cardiocirculatory insufficiency, or clinical seizures were not correlated to the test results. CONCLUSIONS: Neonatal arterial switch operation with combined circulatory arrest and low flow bypass is associated with neurological impairment, but not with reduced development as assessed by formal testing of motor, cognitive, language, and behavioral functions. Perioperative serum level of the neuron-specific enolase is not a valid marker for later developmental impairment.

QT dispersion in the surface electrocardiogram in elderly patients with major depression.

BACKGROUND: QT dispersion (QTd) is a measure of interlead variations of QT interval of the surface 12-lead electrocardiogram (ECG). Increased QTd, found in various cardiac diseases, reflects cardiac instability and is associated with increased cardiac death. Major depressive disorder (MDD) was found to be associated with high cardiovascular mortality rates. This study compares QTd in elderly patients with MDD to normal controls. METHODS: QTd and rate-corrected QTd of 18 physically healthy elderly patients (69.9 +/- 7.6 years) with MDD was compared to nine physically and mentally healthy age- and gender-matched controls (64.1 +/- 12.2 years). RESULTS: QTd and rate-corrected QTd were significantly higher in MDD compared to controls (68 +/- 30 vs. 40 +/- 13 ms, P=0.002 and 81 +/- 39 vs. 43 +/- 13 ms, P=0.001, respectively). Intra- and inter- observer reproducibilities were highly correlated (r=0.96, P <0.0001; r=0.88, P <0.001, respectively). LIMITATIONS AND CONCLUSIONS: The major limitations of this study are the small number of subjects and the fact that all the patients were maintained on antidepressant medication. However, it seems that QTd analysis might shed light on possible autonomic imbalance and also provide a novel cardiovascular risk factor for increased cardiac death in MDD.

Lithium and male sexual function in affective patients.

The aim of the present study was to evaluate sexual function and behaviour in male patients who take lithium. Participants included 35 bipolar and schizoaffective men, aged 43.3 +/- 9.6 years, who were in euthymic state and were receiving lithium as the sole medical treatment. Eleven patients (31.4%) reported sexual dysfunction on at least two items of the sexual function questionnaire. Notable results were reduction in frequency of sexual thoughts and loss of erection during sex in 23 and 20% of patients, respectively. Difficulties in achieving and maintaining erections (ease of arousal) were reported in 14% of patients. Nevertheless, almost all patients reported preserved pleasure during sexual activity and were satisfied with their sexual performance. There was no difference in serum lithium levels in patients with and without sexual dysfunction. No statistical correlation was found between sexual function scores and serum lithium levels. Lithium therapy may impair desire and arousal, yet it does not appear to have a major impact on patient self-satisfaction or subjective sense of pleasure during sexual activity. The degree of sexual dysfunction as reported in the present study was not a source of distress to patients and did not cause noncompliance.