Sex Differences in Hierarchical Stability in a Formation of a Mixed-sex Group of Rhesus Macaques

Forming groups of captive rhesus macaques (Macaca mulatta) is a common management practice. New formations of unfamiliar macaques can be costly, with high levels of trauma, particularly as intense aggression is used to establish a dominance hierarchy. Combining previous subgroups into one new group may be beneficial, as some individuals already have established dominance relationships. We tested this hypothesis by forming a new mixed-sex group of rhesus macaques that combined an established group of females with an established group of males. Prior to the mixed-sex group formation, both the female and male hierarchies had been stable for 3 y; after mixed-sex group formation these hierarchies were maintained by the females and were initially maintained by the males for 3 wks. However, the temporary hospitalization (due to a laceration caused by aggression) of the alpha male destabilized the male hierarchy. Age and weight then predicted male rank. Temporary hospitalizations resulted in rank changes for the males, evidenced by reversals in subordination signals. This study indicates that using established groups of familiar individuals may maintain female hierarchical stability in a mixed-sex group formation, but further research is needed to understand how to maintain and predict male hierarchical stability to reduce trauma. Improved knowledge of hierarchical stability would be invaluable to managers of large rhesus macaque groups and would help improve the welfare of captive rhesus macaques.

Social group formations of captive nonhuman primates (NHPs) occur frequently for a variety of reasons (for example, breeding, research purposes, permanent housing arrangements). Rhesus macaques are the most used NHP in biomedical research.¹⁵ Classified as highly despotic, rhesus macaques rely on a heavy use of aggression to maintain and reinforce their dominance hierarchy,⁴⁷ which ultimately governs access to resources and mates.⁵⁰ Extensive aggression can result in significant traumas and even death.^12,51 Reducing trauma is therefore an important goal both to maintain the animals’ welfare and to minimize the associated cost of care. Thus, this research is aimed at improving the success of forming groups with minimal trauma.One strategy to potentially improve the success of group formations and decrease aggression is to mix familiar individuals with an already established dominance relationship.^18,53 However, dominance ranks are not static and can change if aspects of the social environment change,^1,11,17 such as the loss of keystone individuals³⁴ or addition of new allies.¹⁷ As many NHPs are housed in pairs or small social groups, substantial research has been aimed at understanding pairing success,^14,31,38 but less is known about factors that contribute to successful formations of large, naturalistic social groups. Because high levels of aggression and trauma can occur even in well-established groups,^8,45 gauging social stability in large group formations of rhesus macaques is difficult, as aggression does not necessarily equate to incompatibility or trauma.^8,31,38 Understanding whether individuals maintain their previous hierarchies is critical information for behavioral managers as they form new social groups.Wild female rhesus macaques remain in their natal groups and acquire adjacent ranks to their mothers through coalitionary support.¹⁰ Males also retain their ranks near their mothers while in their natal groups,¹⁶ but after dispersal at sexual maturity and entry into a new breeding group, males mainly enter the group at the bottom of the hierarchy and move up after dispersals or deaths (see²⁶ for general background information and an unusual case of rank acquisition). Because males emigrate from multiple natal groups, many of them will be unfamiliar to one another. Whether male dominance relationships in their natal groups affect their rank in subsequent groups as adults is uncertain, although some research suggests that postnatal nepotism occurs in long-tailed macaques (Macaca fascicularis), with males maintaining a high dominance rank longer in non-natal groups when other male kin are present.²⁵ In many groups in which males originate from multiple natal groups, tenure in the new social group often dictates male dominance rank.²⁶The current research sought to determine whether female and male rhesus macaques would maintain their established same-sex hierarchies during a group formation in which an established group of females was introduced to an established group of males. If previous relationships are maintained, this could indicate that using established groups of familiar same-sex individuals could lessen the trauma and associated costs of a group formation, as individuals would not need to use high levels of aggression to sort out their hierarchy. We predicted that previous social rank, rather than individual attributes, would predict social rank in the new mixed-sex social group.     

Transesophageal echocardiography in NeoChord procedure

Background:

Transapical off-pump mitral valve intervention with neochord implantation for degenerative mitral valve disease have been recently introduced in the surgical practice. The procedure is performed under 2D-3D transesophageal echocardiography guidance.

Methods:

The use of 3D real-time transesophageal echocardiography provides more accurate information than 2D echocardiography only in all the steps of the procedure. In particular 3D echocardiography is mandatory for preoperative assessment of the morphology of the valve, for correct positioning of the neochord on the diseased segment, for the final tensioning of the chordae and for the final evaluation of the surgical result.

Result and Conclusion:

This article is to outline the technical aspects of the transesophageal echocardiography guidance of the NeoChord procedure showing that the procedure can be performed only with a close and continuous interaction between the anesthesiologist and the cardiac surgeon.     

Cough ability measurements and recurrent respiratory symptoms in individuals with Ataxia Telangiectasia

Objectives: Ataxia-Telangiectasia (A-T) individuals often present with respiratory muscle weakness, causing recurrent respiratory system infections, asthma-like symptoms, and chronic cough life-threatening events. The cough flow volume maneuver may reveal powerless airflow needed for efficient cough. The study aims to explore cough ability in relation to the flow/volume maneuver. Methods: Data collected retrospectively from clinical charts of 35 A-T patients (age 12.7?±?4.9 years) included forced expiratory and cough flow/volume maneuvers performed on the same day. Analysis compared among the maneuvers matching indices, numbers of cough-spikes, flow rate decay, and the reference data of similar ages. Adjusted to age, BMI, and number of hospitalizations prior to the tests, values were correlated with the cough indices. Results: Cough peak-flow (C-PF) was propagated within 90?±?20?ms compared with peak expiratory flow (PEF?>?200?ms). C-PF measured values were higher than expiratory peak-flow measured values (3.27?±?1.53?L/s versus 3.02?±?1.52?L/s, respectively, but C-PF (%predicted) values were significantly lower than expiratory peak-flow (%predicted) (46?±?15 versus 68?±?20 %predicted, respectively, p?<?0.002). The number of spikes/maneuver was low when compared with reference (2.0?±?0.8 versus 6–12 spikes) and cough vital-capacity was lower than expiratory vital capacity (0.95?±?0.43 versus 1.03?±?0.47; p?<?0.01). Inefficient C-PF was more prevalent in patients suffering from recurrent respiratory illness. The length of wheelchair confinement duration mostly influenced the C-VC level. Conclusions: The cough flow–volume curve can be applied as a method to follow cough ability in patients with A-T who showed a significantly reduced cough capacity. Further studies are needed to establish if the findings may aid decisions regarding cough assistance.     

JC Virus T-Antigen DNA in Gastrointestinal Mucosa of Immunosuppressed Patients: A Prospective,Controlled Study

Background  

JC virus (JCV), a polyoma virus, is the etiological agent of progressive multifocal leukoencephalopathy in immunosuppressed patients. JCV T-Ag has proven oncogenic potential and is expressed in colonic polyps and carcinomas. We proposed that the prevalence of JCV T-Ag DNA is higher in the normal gastrointestinal (GI) mucosa of immunosuppressed patients compared with their immunocompetent counterparts.     

Maternal and fetal serum prolactin levels in cases of premature rupture of membranes

Serum prolactin levels were measured in maternal and fetal sera immediately post delivery in 20 cases of premature rupture of the membranes and in 20 controls. Fetal serum prolactin levels were 781 +/- 265 ng/ml in cases of PRM and 737 +/- 314 ng/ml in controls. Maternal serum prolactin levels were 504 +/- 264 ng/ml in cases of PRM and 731 +/- 361 ng/ml in controls. This difference is statistically significant (t = 1.81, p less than 0.05). A probable role of prolactin in maintaining fetal membrane integrity and the probable effect of the difference in maternal serum prolactin concentration in the two groups on the membranes' viscoelastic properties is discussed.     

Pharmacological,morphological and behavioral analysis of motor impairment in experimentally vitamin C deficient guinea pigs

The scurvy shows an inflammatory disease and gingival bleeding. Nevertheless, in an animal model for guinea pigs, described by Den Hartog Jager in 1985, scurvy was associated with a motor neuron disease with demyelinization of the pyramidal tract, provoking neurogenic atrophy of muscles. Aiming at searching the protective role of vitamin C in nervous system, a pharmacological, morphological and behavioral study was conducted. Three experimental groups were used: A100, animals receiving 100 mg/ vitamin C/ day; A5.0, animals receiving 5.0 mg/vitamin C/ day; and A0, animals without vitamin C. We analyzed the weight gain, muscular diameter and behavioral tests. In all tests examined, we found significant differences between the supplemented groups in comparison with scorbutic group (p<0.05). Thereafter, the animals were killed for histopathology of gastrocnemius muscle, spinal cord and tooth tissues. In addition, a morphometric study of periodontal thickness and alpha-motor neuron cell body diameter were done. The vitamin C-diet free regimen seemed to induce a disruption in spinal cord morphology, involving the lower motor neuron, as confirmed by a significant reduction in neuron perycaria diameter and muscular atrophy, complicated by increased nutritional deficit.     

Correlation of brain stem evoked response audiometry (BERA) with Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS)

The diagnostic value of electric responses from the brain stem (BERA) in neurosurgical patients is still a matter for debate in the literature. Therefore in the study an attempt was made to determine the relationship between GCS scores and BERA recordings. Participants in the study were 64 patients with various types of brain damage. Evoked potentials from the brain stem were registered using the Hortmann BERAmodul apparatus. To facilitate the interpretation of results a special scale was developed for quantitative measurement of changes in BERA recordings. Abnormalities in BERA recordings were reflected in changes in GCS scores, and correlation between the two dimensions was found to be statistically significant. The relationship between BERA recordings and GOS scores was also significant: pathological changes in BERA recordings assessed as severe were associated with an unfavorable therapeutic outcome in the GOS. The presented findings indicate auditory evoked brain stem response (BERA) usefulness for objective evaluation of brain-damaged patients' clinical state.     

Postoperative rhabdomyolysis in patients with end-stage renal failure

Four patients with end-stage renal failure on intermittent hemodialysis in whom rhabdomyolysis developed after major surgery are described. This possibly underdiagnosed complication was manifested by extreme hyperphosphatemia, hypocalcemia, and elevated creatine phosphokinase levels. Serum myoglobin levels further supported the diagnosis. The metabolic abnormalities reached a peak on the fourth postoperative day. The possible precipitating factors included opiates used for anesthesia and postoperative pain control, anesthetic agents, and surgical position. The preferred treatment option is increasing dialysis to control hyperphosphatemia and hypocalcemia.