Smaller fetal thymuses in pre-eclampsia: a prospective cross-sectional study.

OBJECTIVE: To determine whether the thymus is smaller in fetuses of pre-eclamptic mothers than in those of normal controls. METHODS: This was a cross-sectional, prospective, comparative study of sonographically determined fetal thymus measurements in 39 pregnancies with pre-eclampsia and 70 healthy pregnancies. RESULTS: Both the diameter and the perimeter of the fetal thymus were smaller in pregnancies with pre-eclampsia than in healthy controls. The means of the thymus diameters were 28.6 ± 5.9 and 32.9 ± 4.5 mm and of thymus perimeters 80.9 ± 16.5 and 93.1 ± 16.6 mm for pre-eclamptic and healthy pregnancies, respectively (P < 0.001). General linear models showed that smaller fetal thymuses in pre-eclampsia were independent of gestational age, estimated fetal weight, small for gestational age status and antenatal steroid use. CONCLUSIONS: Pre-eclampsia is associated with smaller fetal thymuses.

The potent bone-resorbing mediator of Actinobacillus actinomycetemcomitans is homologous to the molecular chaperone GroEL.

Actinobacillus actinomycetemcomitans is a Gram-negative bacterium implicated in the pathology of localized juvenile periodontitis, a condition involving rapid destruction of alveolar bone. We have established that gentle extraction of this bacterium in saline releases a proteinaceous fraction (which we have termed surface-associated material [SAM] which has potent osteolytic activity in the murine calvarial bone resorption assay. Fractionation of the SAM has now revealed that activity is associated with a 62-kD protein. This bone-resorbing activity can be blocked by a monoclonal antibody (raised to the whole bacterium) that is claimed to recognize a protein homologous to the Escherichia coli molecular chaperone GroEL. Purification of this bone-resorbing protein to homogeneity has been achieved by a combination of anion exchange, gel filtration, and ATP-affinity chromatography and the NH2-terminal sequence shows > 95% homology to E. coli GroEL. This GroEL homologue is found in the SAM of A. actinomycetemcomitans but is not found in the osteolytically active SAM from other Gram-negative or Gram-positive bacteria. The GroEL protein from E. coli, but not from Mycobacterium tuberculosis and Mycobacterium leprae, also showed activity in the bone resorption assay. We believe this to be the first observation that a molecular chaperone has the capacity to stimulate the breakdown of connective tissue.

Calcium regulation of skeletal myogenesis. II. Extracellular and cell surface effects.

The process of myoblast fusion during skeletal myogenesis is calcium regulated. Suppression of fusion is obtained by lowering medium [Ca2+] and re-initiated by raising medium [Ca2+]. Previously, we showed that such changes in medium [Ca2+] produced concomitant changes in myoblast [Ca2+] and that a critical cellular concentration of calcium must be present in myoblasts for fusion to occur. In this study, we report on further investigations on the relationship between myoblast [Ca2+] and fusion and also present data which suggest that an outer cell surface pool of calcium is involved in the fusion process. Cellular [Ca2+] must reach greater than 0.8 pmoles/cell and the medium [Ca2+] must be greater than 0.2-0.4 mM for myoblast fusion to occur. These conditions do not have a trigger effect on the entire myoblast population; instead, myoblast fusion was a dose-dependent linear response. If medium [Ca2+] was not maintained at 0.9 mM then cellular [Ca2+] decreased below a critical 0.8 pmoles/cell nucleus and fusion ceased. The cell surface pool of calcium was detected with the calcium antagonist lanthanum. A defined culture medium with 0.9 mM Ca2+ was used to maintain cell viability, and to prevent precipitation of medium components and changes in medium pH with La3+ (0.1 mM). La3+ did not enter the myoblasts as detected by electron microscopy, did not inhibit Ca2+ movement into the cells and the cellular [Ca2+] was sufficient to promote myoblast fusion. Under these conditions, myoblast fusion was inhibited. Morphologically, the fusion-suppressed myoblasts resembled those suppressed by lowered medium [Ca2+]. After removal of the fusion-block by washing, the myotubes that formed were equivalent to those present in unaltered cultures. These results suggest that a La3+ displaceable Ca2+ pool exists at the surface of myoblasts which is involved in myoblast fusion. Thus, it appears that myoblast fusion is dependent on the continuous presence of cell surface calcium and an adequate intracellular Ca2+. An influx of calcium alone is not sufficient to promote myotube formation.

Health status, somatization, and severity of posttraumatic stress disorder in Vietnam combat veterans with posttraumatic stress disorder.

OBJECTIVE: A two-part study was conducted to examine the health status of Vietnam veterans with posttraumatic stress disorder (PTSD). In part 1, veterans with and without PTSD were compared on health behaviors and on self-reported and physician-rated health problems. Consistency of self-report with physician rating for health problems across the two groups was compared. In part 2, the association between health status and PTSD symptom severity, depression, somatization, and health behaviors in PTSD patients was evaluated. METHOD: In part 1, 276 combat veterans (225 with PTSD and 51 without PTSD) provided health status information, and medical records were reviewed. In part 2, 225 PTSD patients completed standardized PTSD severity, somatization, and depression measures. RESULTS: When analyses controlled for age, socioeconomic status, minority status, combat exposure, alcohol use, and pack-year history, veterans with PTSD reported and were rated as having a greater number of health problems than veterans without PTSD. Agreement between self-report and physician ratings for both groups ranged from low to moderate. Level of agreement between patient and physician was similar across groups. In the analysis of veterans with PTSD, somatization and PTSD symptom severity were significantly related to self-report of health problems, whereas only PTSD symptom severity was related to physician-rated health. Pack-year history was significantly related to self-reported health status in both groups. CONCLUSIONS: The presence and severity of PTSD in veterans were associated with greater physical health problems and conditions. Psychological variables (e.g., PTSD status, PTSD severity, somatization) and a behavioral variable (pack-year history) were related to health status.

Influence of nutritional status on growth hormone-dependent circulating somatomedin-C activity in mature sheep.

The effect of daily administration of ovine GH for a period of 4 weeks on somatomedin-C biological activity in plasma was investigated in mature Merino sheep fed a maintenance energy intake (low plane; LP) or 1.6 times this amount (high plane; HP). The GH treatment resulted in a significant (P less than 0.05) increase in plasma GH levels in blood samples collected 23.5 h after each daily injection in both LP and HP groups. Plasma concentrations of somatomedin-C activity and insulin were significantly stimulated to a maximum level by the third GH injection and remained at this level for 7 days. Subsequently, circulating levels of both hormones fell to 40-50% of the peak response to GH and returned to basal levels within 48 h of the cessation of GH injections. In the HP group the response of plasma insulin and somatomedin-C activity to GH injection was greater than in the LP group.

Drug use and validity of substance use self-reports in veterans seeking help for posttraumatic stress disorder.

The present study assessed drug use and the validity of self-reports of substance use among help-seeking veterans referred to a specialty clinic for the assessment of posttraumatic stress disorder (PTSD). Patients (n = 341) were asked to provide a urine sample for use in drug screening as part of an evaluation of PTSD. Self-reports of substance use were compared with same-day supervised urine samples for 317 patients who volunteered to participate in a drug screening. Results suggested that self-reports were generally quite valid. Only 8% of the cases involved patients not reporting substance use detected by urine screens. A total of 42% of the participants were identified as using drugs of abuse (excluding alcohol) through self-report and urine drug screens. Among participants using drugs, PTSD diagnosis was significantly associated with greater marijuana and depressant use as compared with stimulant (cocaine and amphetamines) use.

Chronic posttraumatic stress disorder and chronic pain in Vietnam combat veterans.

A study was conducted to investigate chronic pain patterns in Vietnam veterans with posttraumatic stress disorder (PTSD). Combat veterans with PTSD completed standardized PTSD severity, pain, somatization, and depression measures. Of 129 consecutive out-patient combat veterans with PTSD, 80% reported chronic pain. In descending order were limb pain (83%), back pain (77%), torso pain (50%), and headache pain (32%). Compared to PTSD combat veterans without chronic pain, PTSD veterans who reported chronic pain reported significantly higher somatization as measured by the Minnesota Multiphasic Inventory 2 hypochondriasis and hysteria subscales. In the sample of 103 combat veterans with PTSD and chronic pain, MMPI 2 hypochondriasis scores and B PTSD symptoms (reexperiencing symptoms) were significantly related to pain disability, overall pain index, and current pain level MMPI 2 hypochondriasis and depression scores were also significantly related to percent body pain. These results are discussed in the context of current conceptualizations of PTSD.

Prevalence and correlates of heavy smoking in Vietnam veterans with chronic posttraumatic stress disorder.

A study was conducted to investigate smoking patterns in 445 Vietnam veterans with and without posttraumatic stress disorder (PTSD). Combat veterans with PTSD reported similar occurrence of smoking (53%) compared to combat veterans without PTSD (45%). For those who smoked, combat veterans with PTSD reported a significantly higher rate of heavy smoking (> or = 25 cigarettes daily): 28% of combat veterans without PTSD were heavy smokers and 48% of combat veterans with PTSD were heavy smokers. PTSD diagnosis and heavy smoking status were independently and differentially related to motives for smoking. In combat veterans with PTSD, heavy smoking status was positively related to total health complaints, lifetime health complaints, health complaints in the past year, negative health behaviors, total PTSD symptoms, DSM-IV C cluster (avoidance and numbing) and D cluster (hyperarousal) PTSD symptoms. Heavy smoking status was also associated with fewer positive health behaviors.

Doppler sonographic measurements of arterial blood flow and their repeatability in the equine foot during weight bearing and non-weight bearing.

In six normal adult horses, pulsed-wave Doppler sonographic inspections were made of the left and right lateral palmar proper digital artery (LPPDA) of each thoracic limb. Using a two-period, crossover design with repeated measures, each LPPDA was inspected on four occasions throughout the day over a 7 hour period and, on each occasion, with the limb weight bearing and non-weight bearing. In comparison with the observations made during weight bearing, there were significant increases (P<0.001) in blood-flow velocities when the limb was non-weight bearing. There was no relationship between blood velocities and the time of day, the order in which the inspections were made, resting heart rate, age of the horse, or hoof angle. In both weight bearing and nonweight bearing, the Doppler waveform demonstrated a systolic peak followed by at least two diastolic peaks and an end diastolic plateau. Horses that moved least during sonographic inspections had the lowest co-efficients variation.

Postprandial arterial vasodilation in the equine distal thoracic limb.

The effects of feeding on blood flow to the equine foot are poorly understood. In a temperature-controlled room, duplex Doppler ultrasonographic observations were made pre- and postprandially of the lateral proper palmar digital artery of 5 horses, randomly assigned to twice and 4 times daily feeding in an unbalanced 2 period crossover design. Arterial diameter and blood velocity were measured over 4 h and additional observations made of heart rate, blood pressure, total plasma protein, packed cell volume, plasma glucose and insulin. There was no effect of the feeding regimen on any variable. Postprandially, there were significant increases in arterial diameter, blood velocity, total plasma protein, plasma glucose and insulin; the other variables were unchanged. It appeared that the normal postprandial response was an increase in blood flow to the foot. The value of ultrasonography for noninvasive investigation of the peripheral vasculature of the conscious horse was established; and in the future it may have a role in the diagnosis of vascular diseases of the foot.

Use of Doppler ultrasonography to evaluate renal arterial blood flow in horses.

OBJECTIVE: To obtain Doppler ultrasonographic images of renal arteries in horses and to establish reference range values for systolic and diastolic renal arterial blood flow and resistive indices. Also to determine whether Doppler ultrasonography could be used in horses to detect changes in renal blood flow after IV administration of furosemide. ANIMALS: 11 clinically normal adult horses. PROCEDURES: Pulsed-wave Doppler examinations were performed on arcuate arteries of 5 sedated horses. Continuous-wave Doppler examinations were performed on pyelorenal arteries in 7 nonsedated horses and were repeated in 6 horses after furosemide administration. Peak-systolic velocity (SV) and end-diastolic velocity (EDV) were measured and the resistive indices (RI) were calculated. RESULTS: Using pulse-wave Doppler ultrasonography in sedated horses, arcuate arteries were determined to have a SV of 0.406 +/- 0.116 m/s (mean +/- SD), EDV of 0.184 +/- 0.057 m/s, and RI of 0.549 +/- 0.044. Using continuous-wave Doppler ultrasonography in nonsedated horses, pyelorenal arteries were determined to have SV of 1.047 +/- 0.009 m/s, EDV of 0.510 +/- 0.006 m/s, and RI of 0.512 +/- 0.004. Doppler waveforms from the arcuate and pyelorenal arteries had a low resistance flow pattern, characterized by a systolic peak followed by a continuous antegrade diastolic flow. After furosemide administration, the pyelorenal arterial velocities increased, but the RI remained unchanged. CONCLUSIONS: Doppler ultrasonography may be used to record renal blood flow in horses and to detect changes following furosemide administration. CLINICAL RELEVANCE: Doppler ultrasonographic images may assist in the diagnosis of renal diseases that affect either blood flow or Doppler waveform.

Rearing performance of farmed fallow deer (Dama dama).

The ability of fallow does to rear fawns to weaning age was examined in a group of 243 adult does of known age (Group 1) and 509 adult does of unknown age (Group 2). All does had between 1 and 8 opportunities to rear fawns. There was an increasing proportion of does that failed to rear a fawn to weaning age as the number of rearing opportunities increased, although most does (93.6%) only failed on one occasion. A small percentage of does in groups 1 and 2 failed repeatedly to rear fawns to weaning. At slaughter, the presumed causes of failure in chronic non-breeders included pyometron, cystic ovaries, cervical cysts, a vulval neoplasm and salpingitis. The overall rearing success of both groups of deer was 82.4% and there was no consistent pattern of rearing failure relating to parity or previous rearing history.

Echocardiographic measurements in greyhounds, whippets and Italian greyhounds--dogs with a similar conformation but different size.

OBJECTIVE: To determine the effect of body size on various echocardiographic measurements in dogs of widely differing size, but identical body conformation. DESIGN: A randomised echocardiographic study of healthy sighthounds. ANIMALS: 60 dogs comprising an equal number (20) of racing Greyhounds, Whippets and Italian Greyhounds. PROCEDURE: Following sedation with acepromazine and morphine, and acclimatization, a thorough echocardiographic examination was performed on each dog using standard methods. RESULTS: Dimensions measured echocardiographically were highly correlated with body size. These data were subsequently examined using analyses of variance and regression. Body surface area was the best overall predictor of dimensional measurements. In comparison to previous studies using dogs of differing size and conformation, the spread of values for measurements plotted against body surface area showed substantially narrower ranges. Thus, the relationship between echocardiographic measurements and body surface area was much closer for dogs with an identical somatotype than for dogs of differing size and conformation. Commonly used ejection phase indices (fractional shortening, ejection fraction and velocity of circumferential fibre shortening) were negatively correlated with body size. In contrast, the thickening fraction of the left ventricular posterior wall, another ejection phase index, was independent of body weight and body surface area for all three breeds and when the data were pooled. CONCLUSION: Taken in consideration with previous work, this study demonstrates that body conformation and body size both influence canine echocardiographic measurements. Commonly used ejection phase indices are significantly affected by body size, with larger sighthounds having lower values. A more appropriate method of quantitating left ventricular function may be the determination of the thickening fraction of the left ventricular posterior wall.

Smoking in help-seeking veterans with PTSD returning from Afghanistan and Iraq.

Past research has shown that veterans and individuals with posttraumatic stress disorder (PTSD) have increased rates of smoking. However, the rates of smoking in younger help-seeking veterans returning from Afghanistan and Iraq, and possible correlates of smoking among this population are unknown. In this study, we evaluated the rate of lifetime and current smoking among a sample of 90 returning male veterans diagnosed with PTSD. Fifty-nine percent reported a lifetime history of smoking including 32% that were current smokers. Current smokers were significantly younger than non-smokers. Current smokers (mean age=31) reported a mean age of smoking onset as 15.86 with a pack year history of 8.89. These smokers reported on average five previous quit attempts. According to a stages of change model, one-half of the smokers were in the contemplation phase of stopping smoking (50%), 29% were in the pre-contemplation phase and 21% were in the preparation phase. The results are placed in the context of non-psychiatric and psychiatric smokers.

Pulmonary dendritic cells and alveolar macrophages are regulated by gammadelta T cells during the resolution of S. pneumoniae-induced inflammation.

gammadelta T cells commonly associate with mucosal and epithelial sites, fulfilling a variety of immunoregulatory functions. While lung gammadelta T cells have well-characterized pro-inflammatory activity, their potential role in the resolution of lung inflammation has yet to be explored in any detail. Indeed, given the importance of minimizing inflammation, the cellular mechanisms driving the resolution of lung inflammation are poorly understood. Using a murine model of acute Streptococcus pneumoniae-mediated lung inflammation, we now show that resolution of inflammation following bacterial clearance is associated with a > 30-fold increase in gammadelta T-cell number. Although inflammation eventually resolves in TCR delta(-/-) mice, elevated numbers of alveolar macrophages and pulmonary dendritic cells, and the appearance of well-formed granulomas in lungs of TCR delta(-/-) mice, together indicated a role for gammadelta T cells in regulating mononuclear phagocyte number. Ex vivo, both alveolar macrophages and pulmonary dendritic cells were susceptible to lung gammadelta T cell-mediated cytotoxicity, the first demonstration of such activity against a dendritic cell population. These findings support a model whereby expansion of gammadelta T cells helps restore mononuclear phagocyte numbers to homeostatic levels, protecting the lung from the consequences of inappropriate inflammation.

Dietary n-3 and n-6 fatty acids alter avian glucose metabolism.

(1) This investigation studied the effects of dietary saturated and polyunsaturated fatty acids (PUFAs) from the n-3 and n-6 series on insulin action and glucose uptake in broiler chickens. (2) One-day-old male chicks were fed on a commercial starter diet for 3 weeks, randomly divided into three groups (n = 6) and fed ad libitum on isonitrogenous experimental diets of equal energy density for a further 6 weeks. The diets contained 20.8 g/100 g protein and 80 g/kg of either edible tallow, fish oil or sunflower oil, giving diets high in saturated fatty acids, n-S PUFAs or n-6 PUFAs, respectively. (3) Jugular catheterisation was performed under general anaesthesia during week 4 of the dietary treatments and the birds given 7 d post-surgery to recover. To estimate insulin action, a bolus glucose infusion (1 g/kg) was given to each chicken and sequential blood samples taken over a one-hour period. To estimate the disappearance rate of glucose from the plasma and its incorporation into tissues, 2-deoxy-D-3H glucose (2DG-3H glucose) was infused into each chicken (50 microCi) 2 d later. (4) Although there were no significant differences in glucose clearance rate following the glucose infusion, the maximal insulin release in response to the glucose infusion was higher in the tallow group than in either the n-3 or n-6 PUFA dietary groups. There were no significant differences in the clearance rate of 2DG-3H glucose. Labelled glucose incorporation into the breast muscle was greater in birds given fish oil than in birds given tallow and significantly greater than in birds given sunflower oil. (5) The data suggest that the type of dietary fat can influence glucose metabolism and that this change in glucose utilisation may alter the energy metabolism of the broiler.

Physiology of the sternoradialis muscle: sexual dimorphism and role in amplexus in the Leopard frog (Rana pipiens).

1. The role of upper arm muscles in amphibian amplexus was investigated. 2. The musculature of the male frog is arranged so that the response to any form of massive stimulation is flexion of the forelimbs, the fundamental pattern in amplexus. 3. The sternoradialis, one of the forelimb flexors, exhibited several sexually dimorphic characters. It was found to be larger in males than females and possessed a large population of small diameter muscle fibers. 4. Mechanical evidence indicated that the male sternoradialis contains a significant number of tonic or slow muscle fibers. These tonic fibers undergo physiological changes during amplexus including a membrane potential shift in the direction of the mechanical threshold and greater efficiency of contraction. 5. It was concluded that the sternoradialis contributes significantly to muscular response in amplexus and that the tonic fibers in this muscle play an important role in amplexus.

The utilization by pigs of methionine from five protein concentrates compared with synthetic methionine.

Pigs (n 100) between 28 and 56 d of age were given diets containing one of five protein concentrates ad lib. The utilization of methionine from the protein concentrates was compared with synthetic methionine. Increasing the methionine content of the diets from 1.5 to 2.2 g/kg diet increased the weight gains of the pigs from 61 g/d to 198-292 g/d. The feed conversion efficiencies decreased from 2.56 to 1.34-1.56. The utilization of methionine from the protein concentrates for weight gain, as compared with synthetic methionine, was meat meal A 0.89, meat meal B 0.97, soya-bean meal 1.02, cotton-seed meal 0.87 and dried skim milk 1.04.

Supplemental protein degradation, bacterial protein synthesis and nitrogen retention in sheep eating sodium hydroxide-treated straw.

1. Alkali (sodium hydroxide)-treated wheat straw was given to six rumen- and abomasal-cannulated sheep to study the rumen degradation of cotton-seed meal (CSM) and barley (B), and the effects of these supplements on nitrogen retention and efficiency of bacterial protein synthesis were measured. 2. N degradation, using porous synthetic (nylon) bags incubated within the rumen (P), and in vivo measurement determined from the abomasal flow of N (V), distinguished quantitatively between the two supplements. Estimates of P, corrected for fractional outflow rates/h (FOR), underestimated estimates of V when FOR of undegraded protein from the rumen (k) of 0.05 and 0.08 were used. Estimates of V for CSM and B were 70.9 and 80.8% respectively. 3. Intakes of alkali-treated straw were not affected by the supplements. Intakes of digestible organic matter (DOM) for the diets comprising alkali-treated straw alone (W), straw plus CSM (WC) and straw plus barley (WB) were 477, 575 and 590 g/d respectively (P less than 0.05) and organic matter (OM) apparently digested in the rumen (OMADR) was 339, 399 and 435 g/d respectively (P less than 0.05). 4. On W, WC and WB respectively, flows at the abomasum were 11.0, 14.0 and 13.3 g/d for bacterial N (P less than 0.05) and 0, 2.8 and 0.5 g/d for dietary supplemental N; g bacterial N/kg OMADR were 32.4, 35.6 and 30.9 (P greater than 0.05) and N balances were 2.37, 4.27 and 3.29 g/d (P less than 0.05) on the respective treatments. It was suggested that supplements increased total OM intake as a result of increased OM digested in the rumen rather than OM flow from the rumen.