Sex Differences in Cognitive Flexibility and Resting Brain Networks in Middle-Aged Marmosets.

Sex differences in human cognitive performance are well characterized. However, the neural correlates of these differences remain elusive. This issue may be clarified using nonhuman primates, for which sociocultural influences are minimized. We used the marmoset (Callithrix jacchus) to investigate sex differences in two aspects of executive function: reversal learning and intradimensional/extradimensional (ID/ED) set shifting. Stress reactivity and motor function were also assessed. In agreement with human literature, females needed more trials than males to acquire the reversals. No sex differences in ED set shifting or motivational measures were observed. The findings suggest enhanced habit formation in females, perhaps due to striatal estrogenic effects. Both sexes showed increased urinary cortisol during social separation stressor, but females showed an earlier increase in cortisol and a greater increase in agitated locomotion, possibly indicating enhanced stress reactivity. Independent of sex, basal cortisol predicted cognitive performance. No sex differences were found in motor performance. Associations between brain networks and reversal learning performance were investigated using resting state fMRI. Resting state functional connectivity (rsFC) analyses revealed sex differences in cognitive networks, with differences in overall neural network metrics and specific regions, including the prefrontal cortex, caudate, putamen, and nucleus accumbens. Correlations between cognitive flexibility and neural connectivity indicate that sex differences in cognitive flexibility are related to sex-dependent patterns of resting brain networks. Overall, our findings reveal sex differences in reversal learning, brain networks, and their relationship in the marmoset, positioning this species as an excellent model to investigate the biological basis of cognitive sex differences.

Cysticercosis of the triceps--an unusual pseudotumor: case report and review.

Cysticercosis is a disease caused by encysted larvae of the tapeworm Taenia solium. Most muscular disease presents with central nervous system involvement or multiple cysts or both. The authors report a 25-year-old woman with a rare single muscle cyst presenting as a tender hard triceps mass. Results of clinical examination and magnetic resonance imaging were indicative of a soft tissue tumor. Excision of the mass revealed purulence, and the histologic diagnosis was cysticercosis. In the differential diagnosis of isolated muscular masses, a rare isolated cysticercus presenting as a pseudotumor should be considered.

Evaluation of study patients with Lyme disease, 10-20-year follow-up.

To determine the long-term impact of Lyme disease, we evaluated 84 randomly selected, original study patients from the Lyme, Connecticut, region who had erythema migrans, facial palsy, or Lyme arthritis 10-20 years ago and 30 uninfected control subjects. The patients in the 3 study groups and the control group did not differ significantly in current symptoms or neuropsychological test results. However, patients with facial palsy, who frequently had more widespread nervous system involvement, more often had residual facial or peripheral nerve deficits. Moreover, patients with facial palsy who did not receive antibiotics for acute neuroborreliosis more often now had joint pain and sleep difficulty and lower scores on the body pain index and standardized physical component sections of the Short-Form 36 Health Assessment Questionnaire than did antibiotic-treated patients with facial palsy. Thus, the overall current health status of each patient group was good, but sequelae were apparent primarily among patients with facial palsy who did not receive antibiotics for acute neuroborreliosis.

Biphasic material properties of lytic bone metastases.

It is necessary to prescribe the mechanical properties of tumor tissue when modeling the metastatically involved skeleton for clarifying the mechanisms of fracture. This study provides mechanical property data for lytic bone metastases. Specimens of human lytic tumor were tested under a confined compression uniaxial creep protocol and the mechanical behavior of the tumor tissue was modeled using linear biphasic theory. The tumor tissue was found to have an aggregate modulus (HA) of 3.6 +/- 1.6 kPa and a hydraulic permeability (k) of 0.59 +/- 0.46mm4 N(-1) s(-1). Tumors with a higher percentage of stromal content were found to be stiffer and more permeable than those with a more cellular composition. No significant differences in aggregate modulus or hydraulic permeability were found between lytic metastases of different types. These data are useful for the development of models to simulate the behavior of the metastatically involved skeleton using theoretical or finite-element analysis techniques and also have significance for developing effective tumor-drug-transport models. We anticipate that specification of the mechanical behavior of this tissue may help to better focus future treatment of lytic bony metastases through better assessment of fracture risk and improved drug delivery.

Neuropsychological deficits in Lyme disease patients with and without other evidence of central nervous system pathology.

A small percentage of Lyme patients develop mild to moderate encephalopathic symptoms months to years after diagnosis and treatment. Their symptoms typically include fatigue, memory loss, sleep disturbance, and depression. However, the etiology of this syndrome remains controversial. It is generally thought that Lyme patients with abnormal cerebral spinal fluid (CSF) have a neurological basis to their illness. To further examine this question, we compared Lyme patients with evidence of abnormal CSF, intrathecal antibody to Borrelia burgdorferi, elevated protein, or a positive polymerase chain reaction for B. burgdorferi DNA (n = 14); Lyme patients with normal CSF (n = 18); and healthy controls (n = 15) on a battery of neuropsychological and personality tests. Although both Lyme groups reported memory problems, only the Lyme group with abnormal CSF had measurable memory deficits. Both Lyme groups had higher depression scores than the normal control group, although depression was not correlated with memory scores. It appears that Lyme patients with abnormal CSF may have a neurological basis to their illness, whereas affective symptoms, common to many chronic disorders, may predispose other Lyme patients to the perception of cognitive dysfunction.

Patient outcomes after decompression and instrumented posterior spinal fusion for degenerative spondylolisthesis.

STUDY DESIGN: A retrospective study of patient outcomes after decompression and fusion for degenerative spondylolisthesis, using the SF-36 survey and a functional questionnaire. SUMMARY OF BACKGROUND DATA: In recent studies, patient outcomes have been examined more specifically; however, detailed functional outcomes are not available nor have widely used outcomes instruments been administered. METHODS: Thirty patients aged more than 40 years (average, 60.1 years) who had degenerative spondylolisthesis were evaluated after decompression and instrumented posterior fusion. Charts and radiographs were also reviewed. Questionnaires were administered by telephone, and consisted of the Medical Outcomes Study short form (SF-36) and 27 questions designed to evaluate function, quality of life, medication usage, and satisfaction with surgical results. RESULTS: Ninety-three percent of patient's were satisfied with their outcomes. Patients improved significantly in their ability to perform heavy and light activities, participate in social activities, sit, and sleep (P < 0.001) and also improved in pain, depression, and medication usage (P < 0.0001). SF-36 data showed significantly better overall assessment of health in all categories than that in a published cohort of patients with low back pain. The current study group also showed no difference in seven of eight categories when compared with the general population. Fusion rate was 93% at an average of 128 days. Three patients required reoperation: two for pseudarthrosis and one for a deep infection. A poorer outcome, scored by the SF-36, was associated with greater preoperative stenosis (P < 0.05) or occurrence of a complication (P < 0.05). CONCLUSIONS: Patients treated with decompression and fusion for degenerative spondylolisthesis had improved functional outcomes, when measured by a disease-specific questionnaire and by widely used instruments.

Testicular microlithiasis is associated with testicular pathology.

OBJECTIVES: To evaluate the impact of testicular microlithiasis (TM) on male health by describing our experience. TM is an uncommon condition characterized by calcium deposits in the lumina of seminiferous tubules. These intratesticular calcifications appear as bright, 2- to 3-mm echogenic foci on testicular ultrasound (US). METHODS: Patients diagnosed with TM by high-frequency testicular US over a 4-year period from two separate institutions were included in this study. Approximately 1100 testicular USs were performed (both hospitals combined) over the 4-year period. Patients were clinically identified by the characteristic appearance of TM on testicular US. Pathologic specimens were obtained in 14 (64%) of 22 patients. RESULTS: Thirty-eight testicles (16 bilateral cases) in 22 patients were found to have TM. The incidence of TM was approximately 2%. Mean age at presentation was 29 years (range 8 to 63). Eight (36%) of 22 patients had testicular malignancies. Five (23%) of 22 patients were infertile. Three (14%) of 22 patients presented with unilateral necrosis of the testes due to spermatic cord torsion. Two patients had varicoceles, 1 patient had epididymitis, and another patient had torsion of an appendix testis. Previously unreported associations of TM and neurofibromatosis (1 patient) and acquired immunodeficiency syndrome (AIDS) (1 patient) were noted. No patient with TM later developed a testicular malignancy, yet the mean follow-up was only 31 months (range 1 to 108). One patient with unilateral TM developed bilateral TM, and 1 patient with bilateral TM subsequently developed unilateral TM. One patient developed spermatic cord torsion and testicular infarction 4 years after previously documented TM. CONCLUSIONS: TM is usually diagnosed by testicular US performed for various indications. TM is an uncommon condition that is found in testes with both malignant and nonmalignant conditions. The association of TM and testicular malignancy suggests regular follow-up with testicular US examinations.

Rapid identification of bacterially contaminated platelets using reagent strips: glucose and pH analysis as markers of bacterial metabolism.

BACKGROUND: One in every 1000 units of platelets is bacterially contaminated, which puts patients at risk for transfusion-associated sepsis and death. However, there is currently no screening test in place to detect contaminated units. The use of commercially available multiple-reagent urine dipsticks for this purpose was evaluated. STUDY DESIGN AND METHODS: Platelet concentrates were inoculated with either sterile saline or suspensions of Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Klebsiella pneumoniae, or Serratia marcescens to a final concentration of 50 colony-forming units (CFU) per mL. The platelets were analyzed daily by the use of multiple-reagent strips, quantitative culture, and glucometry. RESULTS: B cereus grew rapidly, reaching 10(7) CFU per mL 1 day after inoculation, while S. epidermidis grew slowly, achieving similar concentration 4 to 6 days after inoculation. Two of 10 dipstick reagents, glucose and pH, proved useful in detecting bacteria. Both were lower in bacterially contaminated units than in controls. Glucose data obtained from automated analyzers validated the dipstick data. All organisms were detected at concentrations > or = 10(7) CFU per mL, and S. aureus and K. pneumoniae were detected in the range of 10(3) to 10(5) CFU per mL. CONCLUSION: The multiple-reagent test used had a sensitivity and specificity of 95 percent (> or = 10(7) CFU/mL) and 98 to 100 percent, respectively. These data indicate that urine dipsticks can be used to rapidly and inexpensively detect bacterial contamination in platelet concentrates, which potentially will reduce morbidity and mortality at minimal cost.

Transvenous implantation of cardioverter defibrillators in the Electrophysiology Laboratory at CAMC.

Since 1989, 78 patients have had Implantable Cardioverter Defibrillator (ICD) systems implanted in the Electrophysiology Laboratory (EPS) at the Charleston Area Medical Center. Between June 1993 and December 1994, 28 patients (21 males, 7 females) had new transvenous ICD systems successfully implanted in the Electrophysiology Laboratory. Coronary artery disease was present in 22 patients (76%). The mean left ventricular ejection fraction measured 28 percent (range 19%-45%), and the mean follow-up was 159 +/- 112 days (5.3 months). Twelve patients (43%) experienced shock, with an average of three per patient. The implantation of transvenous ICD systems in an electrophysiology laboratory is feasible, efficacious, safe, and associated with rapid patient recovery. With advances in technology, the procedure is becoming more comparable to a pacemaker implantation.

Score for Neonatal Acute Physiology: a physiologic severity index for neonatal intensive care.

The substantial variation in birth weight-adjusted mortality among neonatal intensive care units (NICUs) may reflect differences in population illness severity. Development of an illness severity measure is essential for comparisons of outcomes. The Score for Neonatal Acute Physiology (SNAP) was developed and validated prospectively on 1643 admissions (114 deaths) in three NICUs. SNAP scores the worst physiologic derangements in each organ system in the first 24 hours. SNAP showed little correlation with birth weight and was highly predictive of neonatal mortality even within narrow birth weight strata. It was capable of separating patients into groups with 2 to 20 times higher mortality risk. It also correlated highly with other indicators of severity including nursing workload (r = .59), therapeutic intensity (r = .78), physician estimates of mortality risk (r = .65), and length of stay (R2 = .59). SNAP is an important new tool for NICU research.

Effects of ice and recovery time on maximal involuntary isometric torque production using electrical stimulation.

This study was conducted in partial fulfillment of the requirements of the U.S. Army-Baylor University Graduate Program in Physical Therapy, Academy of Health Sciences, Fort Sam Houston, TX. The opinions and assertions contained herein are the private views of the authors and are not to be construed as official or representing the views of the Department of the U.S. Army or the Department of Defense. The purpose of this study was to investigate the effects of 30-minute ice treatments to the quadriceps femoris muscle and subsequent recovery time on involuntary isometric torque production (the dependent variable) using the Electrostim 180-2. Twenty healthy, male subjects (age 18-35) on active military duty completed the study. Each subject served as his own control. Collected data included maximum current tolerated during electrical stimulation and maximum involuntary isometric torque production pretreatment, immediately posttreatment, and 90 minutes posttreatment. From the statistical analysis, it was concluded that ice application did not significantly affect an individual's ability to tolerate more electrical current or to produce higher maximum involuntary isometric contraction (MIIC) torque values. Results showed a wide variation in subjective response to electrical stimulation. Suggestions for further research and implications for the clinical use of ice in combination with electrical stimulation modalities are discussed. J Orthop Sports Phys Ther 1991;13(5):240-248.

"Never believe an alcoholic"? On the validity of self-report measures of alcohol dependence and related constructs.

A study of 114 male and female alcoholics was conducted to evaluate the validity of information obtained by means of self-report questionnaires. Factor analysis was used to derive composite measures of alcohol dependence, withdrawal symptomatology, pathological intoxication, and alcoholic psychosis. Validation was conducted by comparing these measures with independent and external criteria; that is drinking estimates made by collateral informants, measures of general alcohol involvement, and drinking behavior 6 months after treatment. The results support each type of validity, and thereby contradict the assumption that the alcoholics' self-reports were not accurate. The question of unreliable self-report data due to the demand characteristics of the situation under which the information is obtained is also addressed.