Internet-delivered cognitive behaviour therapy for chronic health conditions: self-guided versus team-guided.

There is growing interest in offering Internet-delivered cognitive behaviour therapy (ICBT) to individuals with chronic health conditions, with this process often being guided by a single clinician. Due to lack of full time personnel, it is sometimes necessary to have multiple clinicians offer guidance or for no guidance to be offered. In this randomized trial, we compared team-guided ICBT (n = 90) to self-guided ICBT (n = 88). Participants completed measures at pre-, post-, and 3-months post-ICBT. Both groups showed similar rates of treatment completion and large improvements on depression and anxiety at post-treatment and follow-up. Unexpectedly, more participants in the self-guided versus team-guided condition showed clinically significant improvement on depression at post-treatment (76.5% vs 49.2%) and follow-up (70% vs 45.6%). Thus, team-guided ICBT may not provide significant benefits compared to self-guided ICBT. However, it may be an alternative approach to consider among a population of high risk individuals that wants or requires closer monitoring of symptoms.Trail registration TRN: NCT03500237; Date: April 18, 2018.

A randomized factorial trial of internet-delivered cognitive behavioural therapy: An 8-week program with or without extended support and booster lesson.

While internet-delivered cognitive behavioural therapy (ICBT) is effective, some patients suggest extended support post-treatment could improve care. In this randomized factorial trial, we examined the benefits of an 8-week therapist-assisted ICBT program offered with or without an optional 4-week extension of support (Factor 1) and with or without an optional booster lesson (Factor 2). Patients screened for ICBT for depression and/or anxiety were randomly assigned to the conditions (N = 434) and we examined the use of the extension and booster, differences between those who did or did not use extension or booster, and the impact of the extension or booster on outcomes, engagement, and satisfaction at 26-weeks post-enrollment. Therapists recorded time and observations with offering support during the extension and booster. In the extension group, 54.4% (n = 56) requested the extension, while in the booster group 50.9% (n = 56) accessed the booster, and in the combined group, 41.6% (n = 47) requested the extension and 51.3% (n = 58) accessed the booster. Those who requested the extension were older, and more likely to report medication and mental health service use and severe mental health-related disability at pre-treatment; they also reported putting less effort into ICBT and finding skills more difficult. The booster was more often used among those with lower symptom severity, and those who put more effort into and had more positive experiences with ICBT. As expected, those assigned to extension sent more messages to their therapist, and those assigned to booster logged in more often. Therapists also took more time to deliver ICBT with an extension (>18 min) or booster (>13 min) compared to the 8-week program, and perceived extension and booster as beneficial for some, but not all patients. Treatment satisfaction was high across conditions, and effect sizes were large from pre-treatment to 26-week follow-up on most measures. No significant group differences were found in this study. Lack of group differences, however, could reflect low use of the extension and booster. Results provide helpful information about the demand for extensions and boosters, and provide directions for future research.

A pragmatic factorial randomized controlled trial of transdiagnostic internet-delivered cognitive behavioural therapy: Exploring benefits of homework reflection questionnaires and twice-weekly therapist support.

With the growing demand for internet-delivered cognitive behavioural therapy (iCBT), this pragmatic factorial (2 × 2 × 2) randomized controlled trial evaluated strategies for facilitating iCBT engagement and outcomes in routine care. Specifically, the benefits to patients and therapists of using homework reflection questionnaires and offering patients twice-weekly therapist support were examined. Patients (n = 632) accepted into iCBT for depression and/or anxiety were randomly assigned to complete homework reflection questionnaires or not (factor 1), receive once- or twice-weekly support (factor 2), and to receive care from therapists employed in one of two settings (iCBT clinic or a community mental health clinic; factor 3). Outcomes were measured at pre-treatment, and 8, 12, and 24-weeks post-enrollment. Therapist time was tracked and a focus group was conducted to examine therapist experiences. No differences in patient outcomes were found between therapists employed in the two settings; as such, these two groups were combined for further analyses. In terms of engagement, homework reflection questionnaires were associated with fewer website log-ins and days accessing iCBT; twice-weekly support was associated with more patient emails sent to therapists. Despite engagement differences, homework reflection questionnaires and twice-weekly support did not significantly impact primary outcomes; all groups showed large improvements in depression and anxiety that were maintained at 24-week follow-up. Therapists perceived a number of benefits and challenges associated with responding to homework reflection questionnaires and offering twice-weekly support; most notably the strategies did not benefit all patients. Twice-weekly support was associated with increased therapist time and organizational challenges. It is concluded that neither completion of homework questionnaires nor offering twice-weekly support significantly improve iCBT in routine care.

Induction of DNA double-strand breaks by monochlorophenol isomers and ChKM in human gingival fibroblasts.

Phenol has been traditionally used in dental treatment as a sedative for the pulp or as disinfectant for carious cavity and root canal. However, phenol is regarded as a mutagenic and carcinogenic agent and its use in dental practice is now therefore restricted. Monochlorophenols are derivatives of phenol, which are still used clinically as root canal disinfectants, they are even more active antiseptics/disinfectants than phenol, and the so-called Walkhoff (ChKM) solution makes use of monochlorophenol for root canal disinfection. Ingredients in the ChKM solution are the monochlorophenol compound 4-chlorophenol (4-CP), camphor, and menthol. In literature, the use of the ChKM solution is controversial because of a possible DNA toxicity of the ingredient 4-CP. However, it is unknown whether ChKM can really induce DNA damage in human oral cells. In this study, the induction of DNA double-strand breaks (DSBs) by ChKM and monochlorophenol compounds (2-chlorophenol, 2-CP; 3-chlorophenol, 3-CP; and 4-chlorophenol, 4-CP) was tested in human gingival fibroblasts (HGFs). DNA DSBs (foci) induced in HGFs unexposed and exposed to monochlorophenols or ChKM solution were investigated using the γ-H2AX DNA focus assay, which is a direct marker for DSBs. DSBs result in the ATM-dependent phosphorylation of the histone H2AX. When cells were exposed to medium or medium + DMSO (1 %) (negative controls), an average of 3 foci per cell were found. In positive control cells (H2O2 + medium, or H2O2 + medium + DMSO (1 %), an average of 35 foci each were found. About 20 DSB foci per cell were found, when HGFs were exposed to 2-CP (4 mM), 3-CP (2.3 mM), 4-CP (2.1 mM), or ChKM (corresponding to 1.5 mM 4-CP). Our results show increasing DNA toxicities in the order of 2-CP < 3-CP < 4-CP < ChKM solution. An additive DNA toxicity was found for 4-CP in combination with camphor in the ChKM solution, compared to the 4-CP alone. No significant differences regarding multi-foci cells (cells that contain more than 40 foci) were found when HGFs were exposed to the EC50 concentrations (given in parenthesis) of ChKM (1.5 mM), 4-CP (2.1 mM), or 2-CP (4 mM). Significantly fewer multi-foci cells were found when HGFs were exposed to the EC50 concentration (given in parenthesis) of 3-CP (2.3 mM), compared to the EC50 concentrations of ChKM, 4-CP, or 2-CP. Monochlorophenol compounds and/or ChKM solution can induce DSBs in primary human oral (cavity) cells, which underscores their genotoxic capacity.

Passive stabilization of capillary bridges in air with acoustic radiation pressure.

Long liquid capillary bridges are normally unstable because of the growth of a mode where one end becomes slender while the other becomes rotund. This Rayleigh-Plateau instability was suppressed for weightless bridges on NASA's KC-135 aircraft by placing the bridge in an acoustic standing wave. With an appropriate acoustic wavelength and amplitude the radiation pressure automatically squeezes more on the rotund portion of the bridge so as to suppress the growth of the relevant capillary mode. Stabilization is a natural consequence of the interaction with the steady sound field.

Left ventricular systolic and diastolic function is unaltered during propofol infusion in newborn swine.

UNLABELLED: Propofol is a cardiac depressant with minimal diastolic effects in the adult myocardium. Cardiac effects of propofol in the newborn are unknown. We examined hemodynamic variables and systolic and diastolic left ventricular function in 12 newborn pigs exposed to propofol at three different infusion rates (7.5, 15, and 30 mg x kg(-1) x h(-1)) in random order with a background of fentanyl (100 microg x kg(-1) x h(-1)). Left ventricular (LV) pressure (Plv) and LV anterior-posterior dimension, determined by sonomicrometry, were continuously monitored. Mean arterial pressure (MAP), heart rate (HR), and LV end-diastolic pressure (LVEDP) were determined at every infusion. Systolic function was assessed by the maximal pressure-time derivative (dP/dt(max)), the slope of the end-systolic pressure-dimension relationship (ESP-D), and by the preload recruitable stroke work index (PRSWI). Diastolic function was assessed by relaxation indices, the minimal pressure-time derivative (dP/dt(min)) and the relaxation time constant (tau), and by a stiffness index, the slope of the EDP-D relationship. MAP decreased approximately 25%, from 75.9 +/- 15.6 to 56.3 +/- 14.8 mm Hg (P < 0.05) with propofol, with no dose effect. HR and LVEDP were unchanged from control. Both dP/dt(max) and dP/dt(min) decreased with propofol infusion, but load-independent indices of systolic function (ESP-D slope and PRSWI) and tau were unchanged. Diastolic stiffness was not affected with either 7.5- or 30-mg x kg(-1) x h(-1) infusions but decreased significantly from 0.27 +/- 0.18 mm Hg/mm at control to 0.18 +/- 0.18 mm Hg/mm (P < 0.05) with propofol 15 mg x kg(-1) x h(-1). With this profile, propofol may be useful for the newborn requiring anesthesia. IMPLICATIONS: Most anesthetics depress heart function in the newborn. We examined both heart contraction and relaxation during anesthesia with propofol in newborn pigs. Propofol had minimal influence on heart function in this model at the doses studied. This may therefore be a useful anesthetic to test in the newborn human.

Computer-controlled cardiopulmonary bypass increases jugular venous oxygen saturation during rewarming.

BACKGROUND: Conventional roller pump apulsatile cardiopulmonary bypass (CPB) was compared with computer-controlled pulsatile bypass, which was designed to recreate biological variability (return of beat-to-beat variability in rate and pressure with superimposed respiratory rhythms). The degree of jugular venous oxygen saturation (SjvO2) less than 50% during rewarming from hypothermic CPB was compared for the two bypass techniques. An SjvO2 less than 50% during rewarming from hypothermic CPB is correlated with cognitive dysfunction in humans. METHODS: Pigs were placed on CPB for 3 hours using a membrane oxygenator with alpha-stat acid-base management and arterial filtration. After baseline measurements and normothermic CPB, the animals were randomized to apulsatile CPB (n = 12) or computer-controlled pulsatile CPB (roller pump speed adjusted by an average of 2.9 voltage output modulations/s; n = 12). The animals were then cooled to a nasopharyngeal temperature of 28 degrees C. During rewarming to stable normothermic temperatures, SjvO2 was measured at 5-minute intervals. The mean and cumulative areas for an SjvO2 less than 50% were determined for all animals. RESULTS: No between-group differences in temperature were noted during hypothermic CPB or during rewarming. The rate of rewarming was not different between groups. Mean arterial pressure, partial pressure of oxygen in arterial blood, and partial pressure of carbon dioxide in arterial blood also did not differ between groups. The hemoglobin concentration was within 0.4 g/dL between groups at all time periods. Mean pulse pressure was 10.0 +/- 4.8 mm Hg in the apulsatile CPB group and 20.7 +/- 5.2 mm Hg in the pulsatile CPB group (p = 0.0002; unpaired t test). Markedly greater mean and cumulative areas under the curve for SjvO2 less than 50% were seen with apulsatile CPB (164 +/- 209 versus 1.9 +/- 3.6% x min, p = 0.021; and 1,796 +/- 2,263 versus 23 +/- 45% x min, p = 0.020, respectively). CONCLUSIONS: Computer-controlled pulsatile CPB was associated with significantly greater SjvO2 during rewarming from hypothermic CPB. Both the mean and cumulative areas under the curve for SjvO2 less than 50% exceeded a ratio of 75:1 for apulsatile versus computer-controlled pulsatile CPB. These experiments suggest that cerebral oxygenation was better preserved during rewarming from moderate hypothermia with computer-controlled pulsatile CPB, which returned biologic variability to the flow pattern.

The sociobiology of everyday life : A new look at a very old novel.

The 1000-year-old novel The Tale of Genji, written by Murasaki Shikibu around 1002 CE, shows the operation of general principles of sociobiology. Isolated from western influences and cloaked in Japanese traditions, the common traits associated with reproductive processes are clearly evident. The novel depicts the differential investment of males and females in offspring, male competitive behaviors, and concerns for paternity, kin selection, reciprocal social exchange, species-typical emotional expression, female mate choice, positive assortative mating, and acknowledgment of hereditary transmission of physical and psychological traits. The nature of human behavior in Genji's time seems little different than now and has all the attributes of species-specific and universal traits. Indeed, it can be argued that the fundamental characteristics of Homo sapiens have never changed, being influenced only in form by culture. The qualitative and quantitative evaluation of ancient texts is a strong methodology for understanding the invariant nature of human behavior.

Scattering observations for tilted transparent fibers: evolution of airy caustics with cylinder tilt and the caustic merging transition.

When a dielectric circular cylinder is obliquely illuminated, the scattering angle associated with the Airy caustics of the cylinder's primary rainbow depends on the tilt of the cylinder. We display records of the scattering pattern for a transparent poly(methyl methacrylate) fiber ranging from small values of tilt through values of tilt that are sufficiently large for the Airy caustics from both sides of the fiber to merge in a meridional plane containing the incident wave vector and the fiber's axis. The records are compared directly with the evolution of the caustic projected onto the observation plane, and certain qualitative features of the global evolution of the caustics are confirmed. Although the observations used laser illumination, they are relevant to anticipating the scattering by sunlit transparent tilted cylinders.

Cerebral hypoxia during cardiopulmonary bypass: a magnetic resonance imaging study.

BACKGROUND: Neurocognitive deficits after open heart operations have been correlated to jugular venous oxygen desaturation on rewarming from hypothermic cardiopulmonary bypass (CPB). Using a porcine model, we looked for evidence of cerebral hypoxia by magnetic resonance imaging during CPB. Brain oxygenation was assessed by T2*-weighted imaging, based on the blood oxygenation level-dependent effect (decreased T2*-weighted signal intensity with increased tissue concentrations of deoxyhemoglobin). METHODS: Pigs were placed on normothermic CPB, then cooled to 28 degrees C for 2 hours of hypothermic CPB, then rewarmed to baseline temperature. T2*-weighted, imaging was undertaken before CPB, during normothermic CPB, at 30-minute intervals during hypothermic CPB, after rewarming, and then 15 minutes after death. Imaging was with a Bruker 7.0 Tesla, 40-cm bore magnetic resonance scanner with actively shielded gradient coils. Regions of interest from the magnetic resonance images were analyzed to identify parenchymal hypoxia and correlated with jugular venous oxygen saturation. Post-hoc fuzzy clustering analysis was used to examine spatially distributed regions of interest whose pixels followed similar time courses. Attention was paid to pixels showing decreased T2* signal intensity over time. RESULTS: T2* signal intensity decreased with rewarming and in five of seven experiments correlated with the decrease in jugular venous oxygen saturation. T2* imaging with fuzzy clustering analysis revealed two diffusely distributed pixel groups during CPB. One large group of pixels (50% +/- 13% of total pixel count) showed increased T2* signal intensity (well-oxygenated tissue) during hypothermia, with decreased intensity on rewarming. Changes in a second group of pixels (34% +/- 8% of total pixel count) showed a progressive decrease in T2* signal intensity, independent of temperature, suggestive of increased brain hypoxia during CPB. CONCLUSIONS: Decreased T2* signal intensity in a diffuse spatial distribution indicates that a large proportion of cerebral parenchyma is hypoxic (evidenced by an increased proportion of tissue deoxyhemoglobin) during CPB in this porcine model. Neuronal damage secondary to parenchymal hypoxia may explain the postoperative neuropsychological dysfunction after cardiac operations.

Neurological outcome in a porcine model of descending thoracic aortic surgery. Left atrial-femoral artery bypass versus clamp/repair.

BACKGROUND AND PURPOSE: In a porcine model of thoracic aortic cross-clamping (AoXC), we compared the incidence and severity of paraplegia with two surgical techniques: left atrial-femoral artery (LA-FA) bypass (BP group; n = 9) and clamp/repair (CR group; n = 8). The descending thoracic aorta was clamped near its origin and distal to the third intercostal artery for 30 minutes. The intervening three intercostal arteries were ligated and divided. METHODS: All animals received methohexital anesthesia and were hyperventilated to a Paco2 of 28 to 32 mm Hg. Animals in the CR group received mannitol, and after AoXC, proximal hypertension was controlled with phlebotomy. In the BP group, proximal hypertension was controlled with LA-FA bypass using a centrifugal pump (Biomedicus 520C). Proximal mean arterial pressure, distal mean arterial pressure, central venous pressure, and cerebrospinal fluid pressure were measured; radioactive microspheres were injected at baseline, at AoXC + 5 minutes, at AoXC + 20 minutes, at AoXC off + 5 minutes, and after resuscitation. Neurological function was assessed at 24 hours. The animals were killed, and the spinal cord was removed to determine spinal cord blood flow. Histological cross sections of the lumbar spinal cord were stained with cresyl violet/acid fuchsin and then examined with light microscopy to determine the ratio of altered to total spinal cord neurons. RESULTS: Fifteen animals survived (one death in each group) and were assessed neurologically at 24 hours after AoXC. Despite better distal perfusion and lumbar spinal cord blood flow in the BP group, during AoXC, and at AoXC off + 5 minutes, there was no significant difference in the severity of spinal cord ischemic injury between groups as assessed neurologically by Tarlov score (P = .90, Mann-Whitney U test). As well, the ratio of altered to total lumbar spinal cord neurons did not differ between groups (P = .24). CONCLUSIONS: In this chronic porcine model, distal circulatory support with LA-FA bypass afforded better distal perfusion and improved lumbar spinal cord blood flow but did not influence the severity of spinal cord ischemic injury when compared with a clamp/repair technique.

Improved arterial oxygenation after oleic acid lung injury in the pig using a computer-controlled mechanical ventilator.

We compared computer-controlled mechanical ventilation programmed for biologic variability of respiratory rate (RR) and tidal volume (VT) with conventional intermittent positive-pressure ventilation (IPPV) in an oleic acid (OA) lung injury model. Seventeen pigs were ventilated with an Ohio 7000 anesthesia ventilator. Minute ventilation (VE) was adjusted to maintain PaCO2 at 30 to 35 mm Hg at baseline and was not altered further. OA was infused at 0.2 ml/kg/h until PaO2 decreased to < 125 mm Hg (F(I)O2 = 0.5). Animals were randomly assigned to continue with conventional IPPV (control group; n = 8) or had IPPV computer-controlled (computer group; n = 9). Hemodynamic, respiratory gas, airway pressure, and volume data were obtained at baseline (before OA infusion), at Time 30 (after infusion), and at 30-min intervals for 240 min after OA. At experiment completion, the lungs were removed to determine the wet:dry weight ratios. The control group had RR fixed at 20 breaths/min. The computer group had a RR of 20 +/- 2.3 breaths/min (range, 15 to 27 breaths/min), comprising 369 different RR values with reciprocal changes in VT over 1,089 s before the program looped to repeat itself. There was no difference between groups in the volume of OA infused. By 120 min after lung injury, animals in the computer group had significantly greater PaO2, associated with a lower Qs/QT. Mean airway pressures and mean peak airway pressures were not different in the two groups. By 180 min, respiratory system compliance (Crs) was significantly lower in the control group. The wet:dry lung weight ratios were greater in the control group. Thus, in a porcine model of OA lung injury, computer-controlled mechanical ventilation, which is programmed for biologic variability, resulted in improved blood oxygenation without increasing mean airway pressures when compared with conventional IPPV.

Isoflurane and halothane impair both systolic and diastolic function in the newborn pig.

PURPOSE: Volatile anaesthetics have considerable effects on diastolic relaxation in the adult myocardium. We hypothesized that isoflurane (1) and halothane (H) may have even greater effects on diastolic function in the newborn, as the newborn heart has increased passive stiffness and altered calcium handling relative to the adult. Using a newborn pig model, we compared I and H at three clinically relevant concentrations with respect to both systolic and diastolic function. METHODS: Sixteen newborn pigs were randomized for study at control (background fentanyl 100 micrograms.kg-1.hr-1 and 0.5, 1.0 and 1.5 MAC of I (n = 8) or H (n = 8). Temperature, arterial blood gases, and LVEDP were controlled. Left ventricular pressure (LVP) was monitored continuously and LV anterior-posterior dimension was determined by using sonomicrometry crystals. Systolic function was assessed by peak positive dP/dT (dP/dTmax) and the slope of the end-systolic pressure-dimension (ESP-D) relationship. Diastolic relaxation was given by peak negative dP/dT (-dP/dTmax) and the time constant for ventricular relaxation (tau). Left ventricular stiffness was calculated from the slope of the end-diastolic pressure-dimension (EDP-D) relationship. RESULTS: At equal MAC concentrations, I and H were identical in effect for every variable studied. Systolic function was depressed at all anaesthetic concentrations. Control dP/dTmax (I:1815 +/- 561 (SD) mmHg.sec-1, H:1841 +/- 509) decreased to 832 +/- 341 with 1.5 MAC I and 691 +/- 127 with 1.5 MAC H (P < 0.05 vs control). ESP-D slope decreased from 62 +/- 31 mmHg.mm-1 at control to 15 +/- 11 with 1.5 MAC I and from 79 +/- 16 to 37 +/- 15 with 1.5 MAC H (P < 0.05 vs control). Diastolic function was affected only at higher MAC anaesthesia. Control tau increased from 18.0 +/- 6 msec to 29.1 +/- 7.5 with 1.5 MAC I and from 20.8 +/- 5.9 to 30.0 +/- 11.3 with 1.5 MAC H (P < 0.05). EDP-D slope was increased at both 1 and 1.5 MAC anaesthesia. EDP-D slope increased from 0.16 +/- 0.24 mmHg.mm-1 at control to 0.58 +/- 0.46 with I MAC I and from 0.16 +/- 11 to 0.50 +/- 0.35 with 1 MAC H. The -dP/dTmax decreased at every MAC level of anaesthesia. CONCLUSION: These combined systolic and diastolic effects help to explain the increased sensitivity of the newborn myocardium to volatile anaesthetics.

Neuroanesthesia adjunct therapy (mannitol and hyperventilation) is as effective as cerebrospinal fluid drainage for prevention of paraplegia after descending thoracic aortic cross-clamping in the dog.

We compared cerebrospinal fluid (CSF) drainage (Group D; n = 8) to neuroanesthesia adjunct therapy (hyperventilation and mannitol administration; Group N; n = 8) for the prevention of paraplegia using a canine model of descending thoracic aortic cross-clamping (AXC; 2.5 mm distal to the left subclavian artery for 30 min). We expected no difference in neurologic outcome between groups. After surgical preparation and a 30-min stabilization period, dogs in Group D had CSF drained prior to application of the AXC. During the period of AXC, CSF was allowed to drain freely in an attempt to have cerebrospinal fluid pressure (CSFP) no greater than central venous pressure (CVP). Dogs in Group N were hyperventilated (PaCO2 28-32 mm Hg) and received 2 g/kg of mannitol prior to AXC and then 1 g.kg-1.hr-1 during clamping. Systemic hemodynamics, CSFP, and arterial blood gases were measured at 1) baseline, 2) 2 min after AXC, 3) 20 min after AXC, 4) 5 min after AXC release, and 5) 30 min after resuscitation. With release of the AXC, PaCO2 was not controlled in Group D; in Group N the minute ventilation was further increased to maintain PaCO2 constant. At precisely 24 h after AXC, the animals were assessed for incidence and severity of paraplegia, using the Tarlov score, by an observer unaware of the experimental protocol. The animals were then killed, and the entire spinal cord was removed for histologic assessment. Multiple sections of the lumbar spinal cord were processed and stained with hematoxylin and eosin, then examined by light microscopy for nonviable neurons in the anterior spinal cord.(ABSTRACT TRUNCATED AT 250 WORDS)

Environmental tracking by females : Sexual lability.

Human females are generally reserved in their sexuality, in keeping with their heavy investment in reproduction. Males tend to be less reserved. Relative to males, however, females demonstrate more variability in sexuality and are more likely to inhibit or express high levels of sexuality. The heightened variability may in part originate with genetic mechanisms that predispose females toward greater variability (the Lyon hypothesis). Menarche, menstrual cycles, menopause, food reactions, responses to living conditions, reactions to cultural factors, and responses to sexual stimuli and potential mates are unique to or are more variable among females than males. There is a correlation between the variation expressed and female reproductive potential-females tend to shift dramatically from sexual inhibition to sexual expression. Females apparently track the quality of the environment and link their sexuality to reproductive opportunities. Successful male reproduction depends less on quality environments and more on the availability of females. In short, females track the environment; males track the females.

Use of neuroanesthesia adjuncts (hyperventilation and mannitol administration) improves neurological outcome after thoracic aortic cross-clamping in dogs.

BACKGROUND AND PURPOSE: Using a canine model of thoracic aortic cross-clamping, we compared the incidence and severity of paraplegia with and without standard neuroanesthesia adjuncts (mannitol administration and deliberate hyperventilation). Better outcome was predicted for animals treated with mannitol and hyperventilation. METHODS: Nineteen dogs (mean +/- SD weight, 21 +/- 3 kg) were anesthetized with methohexital to an isoelectric electroencephalogram. Animals were randomized to group C (control; n = 9) or group M (mannitol administration and deliberate hyperventilation; n = 10). In group C, animals were maintained normocapnic (PaCO2, 38 to 42 mm Hg). In group M, animals were hyperventilated to a PaCO2 of 28 to 32 mm Hg and received mannitol 2 g.kg-1 during surgical preparation, then 1 g.kg-1.h-1 by continuous infusion. The thoracic aorta was cross-clamped for 30 minutes. Systemic hemodynamics, cerebrospinal fluid pressure, and arterial blood gases were measured at (1) baseline, (2) 2 minutes after cross-clamp, (3) 20 minutes after cross-clamp, (4) 5 minutes after cross-clamp release, and (5) 30 minutes after resuscitation. No attempt was made to control the hemodynamic consequences of cross-clamping in either group. With release of the cross-clamp, PaCO2 was not controlled in group C; in group M the minute ventilation was further increased to maintain PaCO2 constant. At precisely 24 hours after cross-clamp the animals were assessed for incidence and severity of paraplegia, using the Tarlov score, by an observer unaware of the experimental protocol. The animals were killed, and the entire spinal cord was removed for histological assessment. Multiple sections of the lumbar spinal cord were processed and stained with hematoxylin and eosin. RESULTS: With application of the cross-clamp, cerebrospinal fluid pressure and central venous pressure increased significantly in both groups. However, in group M the maximal mean cerebrospinal fluid pressure never exceeded baseline values in group C. With cross-clamp release, spinal cord perfusion pressure (distal mean aortic pressure minus mean cerebrospinal fluid pressure) was significantly greater in group M (86 +/- 23 vs 65 +/- 17 mm Hg; P = .0017 between groups). Acid-base balance was better maintained in group M. The incidence and severity of paraplegia were significantly lower in group M (P = .043; Mann-Whitney rank-sums test, two-tailed). In this group 10 of 10 animals could walk and 4 of 10 had complete recovery. In group C 4 of 9 animals were paraplegic. There was a strong negative correlation between the Tarlov score and the ratio of dead to total anterior spinal cord neurons in the lumbar region as assessed by light microscopy (P = .0004; Spearman's rank test). CONCLUSIONS: We conclude that a protocol using standard neuroanesthesia adjuncts (mannitol administration and deliberate hyperventilation) is associated with improved neurological outcome after thoracic aortic cross-clamping of 30 minutes' duration in dogs anesthetized with methohexital.

Treatment of proximal aortic hypertension after thoracic aortic cross-clamping in dogs. Phlebotomy versus sodium nitroprusside/isoflurane.

Thoracic aortic cross-clamping causes proximal aortic hypertension. Theoretically, the method used to treat hypertension can influence spinal cord perfusion pressure and neurologic outcome. Phlebotomy was compared to sodium nitroprusside/isoflurane in terms of ability to treat increased proximal mean aortic pressure (MAPp) after thoracic aortic cross-clamping in dogs. Dogs were assigned randomly to one of three groups depending on the method used to treat hypertension after cross clamping: 1) phlebotomy (n = 10); 2) sodium nitroprusside/isoflurane (n = 11); and 3) control (no treatment) (n = 8). In each dog, anesthesia was maintained with isoflurane in oxygen, 1.4% end-tidal. The thoracic aorta was occluded 2.5 cm distal to the left subclavian artery for 50 min and then was released. Hemodynamics, cerebrospinal fluid pressure (CSFP), and regional blood flows by the radioactive microsphere technique, were measured at 1) baseline; 2) 2 min after aortic cross-clamping; 3) after treatment of proximal aortic hypertension; 4) 5 min after aortic unclamping; and 5) 30 min after resuscitation. At 24 h, a neurologic assessment was performed. Thoracic aortic cross-clamping increased MAPp, decreased distal MAP (MAPd), and reduced lumbar spinal cord perfusion pressure (SCPPl), [SCPPl = MAPd - CSFP], in all three groups. Control of increased MAPp necessitated removal of 36 +/- 9 ml/kg of blood in the phlebotomy group. In the sodium nitroprusside/isoflurane group, sodium nitroprusside (16 micrograms.kg-1.min-1) was infused and end-tidal isoflurane concentration increased to 2.5 +/- 0.7%, restoring MAPp to baseline level.(ABSTRACT TRUNCATED AT 250 WORDS)

Washing, drying, and anointing in adult humans (Homo sapiens): commonalities with grooming sequences in rodents.

Very few behavioral patterns generalize across human and nonhuman species. We describe washing, drying, and anointing sequences in humans (Homo sapiens) that may have analogies with other species. The rank ordering of washing, drying, and anointing body parts was obtained over 3 successive days for 37 men and 60 women. Variation in rank ordering of body parts was nonrandom, and a cephalocaudal progression was evident for each behavior. Reliability of the behaviors as well as the correlations across rankings were highly significant, which indicates a generalized cephalocaudal progression for all 3 behaviors. Women's anointing was most variable, which suggests a more specific function. The cephalocaudal action pattern described for humans is similar to that for Mongolian gerbils and laboratory rats. Cross-species functions, such as these, may add to our understanding of common developmental and learning processes.