Military deployment correlates with smaller prefrontal gray matter volume and psychological symptoms in a subclinical population.

Research investigating the effects of trauma exposure on brain structure and function in adults has mainly focused on post-traumatic stress disorder (PTSD), whereas trauma-exposed individuals without a clinical diagnoses often serve as controls. However, this assumes a dichotomy between clinical and subclinical populations that may not be supported at the neural level. In the current study we investigate whether the effects of repeated or long-term stress exposure on brain structure in a subclinical sample are similar to previous PTSD neuroimaging findings. We assessed 27 combat trauma-exposed individuals by means of whole-brain voxel-based morphometry on 3 T magnetic resonance imaging scans and identified a negative association between duration of military deployment and gray matter volumes in ventromedial prefrontal cortex (vmPFC) and dorsal anterior cingulate cortex (ACC). We also found a negative relationship between deployment-related gray matter volumes and psychological symptoms, but not between military deployment and psychological symptoms. To our knowledge, this is the first whole-brain analysis showing that longer military deployment is associated with smaller regional brain volumes in combat-exposed individuals without PTSD. Notably, the observed gray matter associations resemble those previously identified in PTSD populations, and concern regions involved in emotional regulation and fear extinction. These findings question the current dichotomy between clinical and subclinical populations in PTSD neuroimaging research. Instead, neural correlates of both stress exposure and PTSD symptomatology may be more meaningfully investigated at a continuous level.

Low molecular weight heparin and prevention of postoperative thrombosis in abdominal surgery.

In a prospective, double-blind, randomized multicenter trial the efficacy and safety of low molecular weight heparin and unfractionated heparin were compared for the prevention of postoperative deep vein thrombosis in patients undergoing abdominal surgery. Six hundred and seventy-three patients were randomly allocated to the two prophylaxis groups; 20 of these, however, did not undergo surgery and did not receive any prophylaxis. Of the remaining 653 patients 323 received one subcutaneous injection of 3,000 anti-Xa units of low molecular weight heparin and 330 received subcutaneously 5,000 U heparin three times a day. Treatment was initiated 2 h preoperatively and continued for 7 to 10 days. The occurrence of DVT was determined by the 125I-labelled fibrinogen uptake test and phlebography. Venous thrombosis was diagnosed in 24 of 323 patients (7.4%) treated with low molecular weight heparin and in 26 of 330 patients (7.9%) treated with low-dose heparin. DVT of proximal veins was detected in four patients of the low molecular weight heparin group and in three patients of the low-dose heparin group. During the observation period three pulmonary emboli - one fatal and two non-fatal - occurred in patients receiving prophylaxis with low-dose heparin. No pulmonary embolism was found in patients treated with low molecular weight heparin. Both prophylactic schemes were well tolerated. Intra- and postoperative blood loss, incidence of wound hematoma, frequency and volume of intra- and postoperative blood transfusion were similar in both groups with a slight advantage for the low molecular weight heparin group.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of 3,000 IU aXa of the low molecular weight heparin certoparin with 5,000 IU aXa in prevention of deep vein thrombosis after total hip replacement. German Thrombosis Study Group.

BACKGROUND: The aim of this randomized, double-blind and prospective clinical trial was to investigate whether an increase of the conventional daily dosage (3,000 IU aXa) of the low molecular weight heparin certoparin up to 5,000 IU aXa/day might lower the incidence of deep vein thrombosis (DVT) in patients undergoing elective hip surgery. METHODS: The main criterium of this trial was the incidence of DVT diagnosed by bilateral ascending venography, which was performed either if DVT was clinically suspected or in each remaining patient between the 12th and the 14th postoperative day. A total number of 172 patients were enrolled to receive the conventional dosage of 3,000 IU aXa (Mono-Embolex NM) and 169 patients to receive the high dosage form (5,000 IU aXa) once daily. The mean age (+/-SD) was 69.6+/-9.5 and 67+/-11.7 years. RESULTS: No relevant differences were found concerning predisposing risk factors. The duration of surgery was 93+/-25.2 and 88+/-21.4 min (mean+/-SD). Surgical type and approach were not different between the groups. Deep vein thrombosis was detected in 17 patients (9.9%) in the conventional dose group and in 16 patients (9.5%) in the high dose group (intent-to-treat analysis; n.s.). The rate of bleeding complications was not significantly different except the cell saver volumes (770+/-136 vs 475+/-186 ml; p<0.001). No significant difference was found in the serious adverse event reporting along the lines of EC-GCP (10 vs 8 events; p=0.65). CONCLUSIONS: This clinical trial confirmed that the conventional dosage (3,000 IU aXa/day) of certoparin ensures maximal antithrombotic activity.

Habitability research priorities for the International Space Station and beyond.

Advanced technology and the desire to explore space have resulted in increasingly longer manned space missions. Long Duration Space Flights (LDSF) have provided a considerable amount of scientific research on the ability of humans to adapt and function in microgravity environments. In addition, studies conducted in analogous environments, such as winter-over expeditions in Antarctica, have complemented the scientific understanding of human performance in LDSF. These findings indicate long duration missions may take a toll on the individual, both physiologically and psychologically, with potential impacts on performance. Significant factors in any manned LDSF are habitability, workload and performance. They are interrelated and influence one another, and therefore necessitate an integrated research approach. An integral part of this approach will be identifying and developing tools not only for assessment of habitability, workload, and performance, but also for prediction of these factors as well. In addition, these tools will be used to identify and provide countermeasures to minimize decrements and maximize mission success. The purpose of this paper is to identify research goals and methods for the International Space Station (ISS) in order to identify critical factors and level of impact on habitability, workload, and performance, and to develop and validate countermeasures. Overall, this approach will provide the groundwork for creating an optimal environment in which to live and work onboard ISS as well as preparing for longer planetary missions.

The diagnosis and treatment of a thoracic abscess in an alpaca.

A 6-month-old alpaca presented for lethargy, failure to thrive and leucocytosis. Diagnostic procedures, including thoracic ultrasound, radiographs and a computed tomography scan, were used to document a thoracic mass. Based on appearance and ultrasound-guided aspiration of purulent material, the mass was determined to be a large abscess. The abscess was treated with surgical drainage and long-term antibiotic therapy. The origin of this thoracic abscess was felt to be the caudal mediastinum, secondary to bacterial seeding of the caudal mediastinal lymph nodes. Although an aetiological agent was not definitively determined, the most likely was Actinomyces spp or Arcanobacterium pyogenes. The alpaca made a complete recovery following treatment.

[Thoracoscopically assisted en bloc esophagectomy]. / Thorakoskopisch-assistierte En-bloc-Osophagektomie.

We report outcomes of en bloc esophageal resection with a thoracoscopically assisted laparotomy approach. The operation data were as follows: 41 thoracoscopically assisted procedures, 41 intrathoracic anastomoses, conversion rate 0, 100% R0 resection rate, 25 (15-52) lymph node retrievals, leak rate 2, and one mortality. From these results we conclude that minimally invasive esophagectomy with high intrathoracic anastomosis is a safe procedure. The R0 resection rate, lymph node retrieval, and operating time are comparable with those of the open abdominothoracic approach.

[Active alveolar expansion for prevention of postoperative atelectasis. Functional and clinical effectiveness]. / Aktive alveoläre Expansion zur Prävention der postoperativen Atelektase. Funktionelle und klinische Wirksamkeit.

In a prospective study, the functional and clinical effectiveness of active alveolar expansion was tested by means of an incentive spirometer on 30 patients each of a treatment and control group. All patients (average age 61 and 58 years, respectively) had undergone a transabdominal pelvic artery reconstruction. Pre-operatively active alveolar expansion significantly reduced intrapulmonary right to left shunting from 11.1% to 4.2% of cardiac output (P less than 0.01). Correspondingly, right to left shunting on the second to fifth postoperative day was reduced significantly (P less than 0.05) by 5-10% of cardiac output in the treatment group, cardiac output being significantly (P less than 0.05) reduced by 1 l/min average. Clinically and radiologically there was a definite reduction in pulmonary complications from 40% to 13%. Peri-operatively performed active alveolar expansion is thus an effective method for the reduction of postoperative functional atelectasis and pulmonary complications.

[Reinterventions following the implantation of atrial electrodes (author's transl)]. / Korrektureingriffe nach Implantation von Vorhofelektroden.

During the past 3 years 41 atrial electrodes (36 J-leads and 5 screw-in electrodes) were implanted for stimulation and/or triggering in 39 patients selected by haemodynamic criteria. In seven patients (18%) reinterventions had to be performed because of a rise in threshold (four cases) and dislocation or unstable position of the electrode (three cases). Reposition of the electrode was successful in only one case, while in four cases a ventricular electrode was implanted and the stimulation mode converted to ventricular pacing. In two other patients the complication was managed by changing the type of electrode.

[Fiberoptic bronchoscopy in intensive care medicine--functional efficacy and methodological side effects]. / Die fiberoptische Bronchoskopie in der Intensivmedizin--funktionelle Wirksamkeit und methodische Nebenwirkung.

A prospective study was performed to determine the side effects of fiberoptic bronchoscopy on cardiopulmonary function, the influence of bronchial lavage on cardiopulmonary function, and the functional efficacy of fiberoptic bronchoscopy in obstructive atelectasis due to retained secretions. In 17 patients endotracheal intubation was immediately followed by a significant (P less than 0.01) rise in arterial, pulmonary artery and pulmonary capillary wedge pressure, heart rate, and cardiac output. There were no statistically significant differences in arterial blood gases and intrapulmonary right-to-left shunt. Two patients showed circulatory changes indicative of a heart insufficiency on the left side. A significant increase (P less than 0.001) in intrapulmonary right-to-left shunt from 12% to 17.5%, a significant decline in arterial oxygen tension of 15 mm Hg, and a significant increase of cardiac output from 6.4 to 7.71/min following saline solution lavage (20 ml in each bronchus) were observed in nine patients. The results indicate that bronchial lavage is the essential mechanism for the decline in arterial oxygen tension induced by fiberoptic bronchoscopy. In patients with unstable cardiopulmonary status, the cardiovascular response during bronchoscopy may be hazardous and the bronchoscopist should be aware of the pathophysiologic side effects involved. Fifteen therapeutic bronchoscopies were performed in five critically ill patients with obstructive atelectasis, due to retained secretions. Following the procedure, Qs/Qt declined from 23.9% to 15%, cardiac output from 9.3 to 7.31/min, and arterial Po2 increased from 58.9 to 70.9 mm Hg. The differences were statistically significant (P less than 0.0001). The therapeutic value of fiberoptic bronchoscopy in the treatment of obstructive atelectasis is demonstrated by the significant improvement in cardiopulmonary status.

Intraoperative ultrasonographic detection of occult liver metastases in colorectal cancer.

The efficacy of intraoperative ultrasonographic detection of colorectal cancer liver metastases was evaluated in 85 patients undergoing operation for primary colorectal tumors or liver secondaries. The results of intraoperative ultrasonography were compared with those of preoperative ultrasonography and computed tomography, as well as the intraoperative appearances of the liver. Additional information about the number of metastases was obtained in 12 cases (14.1%); 17 (24.3%) out of 70 metastases could only be detected by intraoperative ultrasonography. In 4 cases (4.7%) these lesions were solitary. As a result, the operative procedure of choice was changed in 15.3% of the patients. We conclude that intraoperative ultrasonography has a significantly higher ability to detect colorectal cancer liver metastases than preoperative methods or intraoperative inspection and palpation. Intraoperative ultrasonography should be performed in patients without preoperative evidence of liver metastases and in all patients with planned resection of metastases.

Ambulance, fire, and police dispatch times compared with the atomic clock.

OBJECTIVES: To quantify any differences between the times used by public safety answering points (PSAPs) in a multijurisdictional county compared with the atomic clock and to determine whether there was consistency in any time differences. METHODS: All 25 ambulance, fire, and police PSAPs were contacted by telephone. The current time in hours, minutes, and seconds on the dispatch center's timepiece was requested. The atomic clock time was simultaneously recorded. Time differences between the reported and atomic clock times were calculated and the absolute values were used to calculate the mean difference. The procedure was repeated one week later. Consistency in time deviation was evaluated by subtracting the time differences between weeks 1 and 2 for each center. RESULTS: All 25 centers were contacted and three declined to participate. Time differences ranged from -551 to 117 seconds (mean difference: 61.2 +/- 120.3) for week 1 and -103 to 79 seconds (mean difference: 36.9 +/- 33.4) for week 2. Time deviations between weeks 1 and 2 were: 0 seconds for one center, 1 to 30 seconds for 12 centers, 31 to 60 seconds for four centers, and more than 60 seconds for five centers. CONCLUSIONS: The maximum time difference between dispatch center and atomic clock times was 551 seconds. This difference may be clinically significant for time-dependent research, quality improvement tasks, or medical legal reviews when multiple PSAPs are involved. Lack of consistency in time deviation over one week suggests systematic adjustment for these differences may not be possible.

[The influence of pregnancy on the venous return from the lower extremities (author's transl)]. / Einfluss der Gravidität auf die venöse Drainagefunktion der unteren Extremitäten

Determination of intravenous pressure in the lower extremities revealed in 77 pregnant women a marked insufficiency of the venous drainage. In the last third of pregnancy the capacity of the venous drainage is reduced by approximately 30 per cent. Determination two to five days post partum showed a significant improvement but not yet complete normalization. The causes of the insufficiency of the venous drainage are hormonal influences, dilating the vessels, which are still active post partum. The insufficient venous return is a major factor in the genesis of varicosity during pregnancy. The disturbance of venous return by the large uterus will result in an increase of static venous pressure on the average of 10 mm Hg. In the upright position this is a qualitatively as well as quantitatively individually variable phenomenon. There ist no relation between the increase in static venous pressure and the occurrence of varicosity.

[Optimation of postoperative prophylaxis of thrombosis in gynaecology (author's transl)]. / Optimierung der postoperativen Thromboseprophylaxe in der Gynäkologie. Ein Vergleich von Heparin, Dihydroergotamin, ihrer Kombination und Azetylsalizylsäure.

The prophylactic effect of heparin dihydroergotamine, the combination of these two (Heparin-Dihydergot) and acetylsalicylic-acid in the prevention of deep vein thrombosis was investigated in a prospective randomized clinical trial involving 454 patients. Evidence of thrombosis was detected by the 125I-fibrinogen-uptake-test in 22 out of 75 patients (29.3%) in the control group. The application of 2 x 0.5 mgDHE or 2 x 5000 IU of heparin reduced the incidence of deep vein thrombosis to 7%, which is statistically significant. After simultaneous prophylaxis with both drugs the incidence dropped to 2%. The combined use of DHE and heparin may be considered the best prophylactic regimen available for lowering postoperative DVT. After application of 3 x 0.5 g of ASS frequency of DVT decreased only to 15.3% and shows poor prophylactic efficacy.

[Thromboembolism prophylaxis with low molecular weight heparin in abdominal surgery]. / Thromboembolieprophylaxe mit niedermolekularem Heparin in der Abdominalchirurgie.

The effect of low-molecular weight (LMW) heparin fragment (one injection of 1500 aPTT [activated partial thromboplastin time]-U/24 h)--group 1--was compared with unfractionated (UF) heparin (3 x 5000 IU/24 h)--group 2--in a randomized prospective double-blind trial of 404 patients (202 patients in each group), aged 50 years or older, undergoing abdominal surgery. The two groups were well matched for thromboembolic risk factors. The first subcutaneous injection was made two hours preoperatively; postoperative injections continued for at least seven days. The radiofibrinogen test served as the test criterion. If positive, phlebography and lung sequence scanning were performed. On complete prophylaxis the thrombosis rate was nearly identical in the two groups--10.8% vs 11.4%. No pulmonary emboli were detected in either group if correctly treated. There was no significant difference between the two groups with respect to peroperative blood loss, re-operation rate and wound haematoma rate. But there was a significantly higher number of injection haematomas in group 2. These results suggest that a single daily injection of 1500 aPTT-U LMW heparin provides effective prophylaxis against postoperative venous thromboembolism.

[Esophageal carcinoma: transthoracic esophagectomy with regional lymphadenectomy and reconstruction with deferred priority]. / Osophaguskarzinom: transthorakale Osophagektomie mit regionaler Lymphadenektomie und Rekonstruktion mit aufgeschobener Dringlichkeit.

In a retrospective analysis the risks were assessed of transthoracic oesophagectomy with mediastinectomy and regional lymphadenectomy followed 48-72 hours later by an abdomino-cervical operation with supra-pancreatic lymphadenectomy, retrosternal gastric interposition and cervical oesophageal stump anastomosis. Results in this group of 37 patients were compared with those in a group of 42 patients who had undergone a transmediastinal oesophagectomy (without thoracotomy) and immediate reconstruction. The 30-day death rate was 8.1% in the former (group I) and 7.1% in the latter (group II), total hospital death rate 10.8% and 11.9%, respectively. The complication rate was similar in the two groups, as was the recorded operative stress. The results indicate that the risk of an oncologically indicated oesophagectomy with regional lymphadenectomy is no greater than that of a palliative transmediastinal oesophagectomy.

[The effect of acute cellular rejection on liver function following orthoptic liver transplantation. Quantitative functional studies with the 14C-aminopyrine breath test]. / Einfluss der akuten zellulären Abstossung auf die Leberfunktion nach orthotoper Lebertransplantation. Quantitative Funktionsuntersuchungen mit dem 14C-Aminopyrin-Atemtest.

To test the effect of acute cellular rejection on liver function as represented by cytochrome-P-450 enzyme activity, the 14C-aminopyrine breath test (ABT) was performed prospectively in 46 patients (31 men, 15 women; mean age 48 [15-66] years) who had undergone a total of 50 orthotopic liver transplantations. Routine biochemical tests were performed daily until the 30th postoperative day, while the ABT was done daily on days 1-10 and three times weekly on days 11-30, and liver puncture biopsies were obtained once weekly or more often if there was clinical suspicion of rejection. Histologically confirmed cellular rejection occurred within the stated period of observation in eight patients (five women, three men; median age 45 [18-59] years). Results of routine laboratory tests (transaminases, bilirubin, thromboplastin time), as well as bile-flow and body temperature, did not vary uniformly. On the other hand, results of ABT at the time of rejection showed a decrease in all patients by an average of 65% (P < 0.01). Changes in the ABT preceded those in other tests by 1-2 days in four patients, being the only measurable functional abnormality in one. All rejection episodes responded to glucocorticoid pulse-treatment (three times 1 g methyl-prednisolone). Using ABT results as criterion, liver function became normal after the glucocorticoid injection within 4-11 days. These data indicate that the ABT is suitable in the routine monitoring of transplant function, thus facilitating early diagnosis and controlled treatment of acute cellular rejection.