Morbidly Obese Patients are Hemodynamically Stable During Laparoscopic Surgery: A Thoracic Bioimpedance Study

Purpose. Morbid obesity caries an increased risk of cardiovascular morbidity and might be associated with intraoperative hemodynamic instability. Based on clinical observation, we hypothesized that during laparoscopic surgery, morbidly obese patients behave hemodynamically similar to the nonobese patients and remain hemodynamically stable. Methods. In a prospective trial, thirty nonobese and tthirty morbidly obese (BMI ≥ 35 kg/m²) patients scheduled for elective laparoscopic surgery were assigned to receive standard balanced anesthesia. We aimed at equianesthetic levels by keeping the BIS (bispectral index) value between 40–50 throughout surgery. End-tidal isoflurane was measured every 5 min. Noninvasive hemodynamic measurements included cardiac index (CI), mean arterial pressure (MAP) and heart rate (HR), recorded every 5 min and at specific predetermined times. Systemic vascular resistance (SVR) was calculated. Episodes of MAP ≤ 60 and MAP ≥ 130 mmHg or HR ≤ 50 and HR ≥ 110 bpm occurring throughout surgery and requiring pharmacological intervention were considered main end-points. Additionally, hemodynamic variables were compared at specific time points and overall throughout surgery. Secondary end-points were CI and SVRI. Results. Heart rate was higher in obese patients in head-up position (79 ± 15 mmHg vs. 65 ± 12 mmHg – P=0.011). SVR was higher in the nonobese group with head-up position (1978 ± 665 dynes s cm⁻⁵ vs. 1394 ± 496 dynes s cm⁻⁵ P=0.01). Mean overall intraoperative MAP, HR, CI and SVR were similar. There were no episodes of MAP ≤ 60 and ≥130 mmHg or HR ≤ 50 and ≥110 bpm in either of the groups. Conclusion. Our study confirmed our hypothesis that for the most periods of laparoscopic surgery, obese patients are hemodynamically as stable as their nonobese counterparts.     

Cervical muscles weakness in chronic whiplash patients

BACKGROUND: Isometric cervical strength has been used for assessing the severity of cervical spine pathologies. However there is a conspicuous dearth of information relating to cervical strength data in patients suffering from chronic whiplash. Therefore the objective of this study was to compare absolute and ratio-based isometric cervical strength scores in chronic whiplash patients with reported corresponding scores in healthy subjects. METHODS: Isometric cervical strength was measured in the directions of flexion, extension, right and left lateral flexion in 97 patients, 51 women and 46 men, using a wall-mounted dynamometer. FINDINGS: Compared to published values of normal subjects, whiplash patients suffered sharp reductions of about 90% in both genders and in all directions. The consistency of the isometric cervical strength scores as indicated by the mean coefficient of variation was relatively low, 17% and 20% in men and women respectively. The flexion/extension strength ratio ranged 0.8--0.9, slightly higher than the reported range for normal subjects. This ratio was highly correlated (r=0.91, P=0.01) with the mean coefficient of variation in a subgroup of 9 patients. INTERPRETATION: In the absence of an obvious reason such as sever atrophy or grossly dysfunctional neurological control the indicated weakness of the cervical muscles may be associated with learned pain avoidance behavior which is typical among this group of patients.     

Trypanosome microtubule-associated protein p15 as a vaccine for the prevention of African sleeping sickness

Trypanosomes cause African sleeping sickness, affecting millions of humans and animals. We tested trypanosome microtubule-associate protein (MAP p15) as a vaccine in mice, and show that p15 (native or recombinant) generated up to 100% protection from an otherwise lethal challenge of a heterologous strain of Trypanosoma brucei. We also tested the adenovirus as a vaccine delivery system and show that both adenoviral vector containing p15 gene or control adenovirus containing lacZ gene generated a protective response and exhibited strong CD8+ T-cell proliferation. These results suggest that the p15 protein itself is an effective vaccine and that the adenovirus may be used to mount a non-specific cellular immune response.     

T-cell vaccination in multiple sclerosis

T cells that are autoreactive against myelin antigens play a pivotal role in the pathogenesis of multiple sclerosis (MS). The concept of T cell vaccination (TCV) has been developed to generate an immune response against these autoreactive pathogenic T cells. Immunologic data accumulated so far demonstrates depletion of T cells reactive against immunodominant myelin peptides after immunization in the animal model of experimental autoimmune encephalomyelitis, as well as in vaccinated MS patients. Clinical trials have confirmed the safety and efficacy of TCV in a small number of immunized MS patients. TCV resulted in reduced relapse rates and slowed the progression of neurological disability and MRI brain lesion load. Recently, there have been several double-blind, placebo-controlled studies initiated to evaluate the role of TCV in MS. Specifically, it is important to examine the effect of early TCV, given after the first episode suggestive of the disease, in order to prevent the process of epitope spreading.     

Causes and consequences of limited attention

This review focuses on the evolutionary causes and consequences of limited attention, defined as the restricted rate of information processing by the brain. The available data suggest, first, that limited attention is a major cognitive constraint determining animals' search for cryptic food, and, second, that limited attention reduces animals' ability to detect predators while involved in challenging tasks such as searching for cryptic food. These two effects of limited attention probably decrease animal fitness. Furthermore, a simulated evolutionary study provides empirical support for the prediction that focused attention by predators selects for prey polymorphism. The neurobiological mechanisms underlying limited attention have been widely studied. A recent incorporation of that mechanistic knowledge into an ecological model suggests that limited attention is an optimal strategy that balances effective yet economical search for cryptic objects. The review concludes with a set of testable predictions aimed to expand the currently limited empirical knowledge on the evolutionary ecology of limited attention.     

Secondary neurologic deficit due to unrecognized spine instability in multitrauma casualties: a report of three cases

We present three cases of major multiple injuries in which delayed diagnosis of spinal instability resulted in neurologic deficit. The spinal injuries, once diagnosed, were treated by urgent surgical stabilization, which resulted in prompt and full recovery. A set of recommendations is proposed to prevent these potentially disastrous consequences.     

Carbamoylphosphonates, a new class of in vivo active matrix metalloproteinase inhibitors. 1. Alkyl- and cycloalkylcarbamoylphosphonic acids

Matrix metalloproteinases (MMPs) are a family of over 20 zinc-dependent enzymes that hydrolyze connective tissue and are involved in a variety of diseases, which are associated with undesired tissue breakdown. This paper reports the synthesis, characterization, and biological evaluation of a novel class of MMP inhibitors based on the carbamoylphosphonic acid function. We report a series of 10 open chain N-alkylcarbamoylphosphonic acids (ranging from R = C(1) to C(6) groups), eight N-cycloalkylcarbamoylphosphonic acids (ranging from cyclopropyl to cyclooctyl rings), and four N,N-dialkylcarbamoylphosphonic acids. The compounds were evaluated in three in vitro models, which consisted of (a) the in vitro invasion across a reconstituted basement membrane, (b) determination of the IC(50) values on recombinant MMP-1, MMP-2 MMP-3, MMP-8, and MMP-9 enzymes, and (c) an in vitro capillary formation model, which is a model of angiogenesis. Several of the compounds were also tested in an in vivo murine melanoma model. The following general conclusions have been reached: Most compounds show selectivity for MMP-2 over the other MMP subtypes examined. Cycloalkylcarbamoylphosphonic acids are more potent than comparable open-chain alkyl compounds. Optimal activity against MMP-2 among the cycloalkyl derivatives was shown by N-cyclopentylcarbamoylphosphonic acid (3m). N,N-Dialkylcarbamoylphosphonic acids that were examined showed weak or no activity. The compounds examined showed toxic effects neither in vitro nor in vivo in the concentrations used. Carbamoylphosphonic acids are water soluble at physiological pH and are stable indefinitely.     

The role of sonographic assessment of cervical length in the prediction of preterm birth in primigravidae with twin gestation conceived after infertility treatment

OBJECTIVE: To identify the risk factors for preterm birth in primigravidae with twin gestation and the role of transvaginal ultrasonographic assessment of the cervix. METHODS: Between January 1996 and December 1996, 54 twin pregnancies were prospectively enrolled. All women were at their first pregnancy. All women conceived following infertility treatments and all had a normal uterine cavity proven by hysterosalpingography (HSG) or hysteroscopy. Multiple logistic regression analysis was used to evaluate the association between the length of the cervix at 18-24 weeks of gestation and outcome variables, controlling for possible confounding factors. RESULTS: The mean +/- SD maternal age was 30.9 +/- 5.3 years (range 22-46), and five of them were aged 40 or more. Nine patients (20.5%) delivered prematurely, defined as spontaneous delivery at or before 34 weeks of gestation. There was no statistically significant difference between women who delivered before or after 34 weeks of gestation in regard to maternal age, body mass index (BMI), weight gain in pregnancy, smoking and work during pregnancy. The mean cervical length of patients who delivered before 34 weeks of gestation (30.1 +/- 6.1 mm) was significantly shorter than that of women who delivered after 34 weeks of gestation (42.2 +/- 6.2 mm; P < 0.001). Cervical length longer than 35 mm predicted delivery after 34 weeks of gestation with sensitivity and specificity of 88.5% and 88.9%, respectively. The positive and negative predictive values were 96.9% and 66.7%. CONCLUSION: A transvaginal ultrasonographic measurement of the cervix > 35 mm at 18-24 weeks in twin gestation can identify patients at low risk for delivery before 34 weeks. Maternal age, BMI, weights gain, smoking and work during the pregnancy did not influence the duration of the pregnancy.