Trismus and trigeminal neuralgia in one patient with colon cancer

A 64-year-old man got trismus and trigeminal neuralgia under the diagnosis of colon cancer with mandibular metastasis after emergency appendectomy and elective hemicolectomy. The patient chose to forgo further surgery and was given only palliative chemotherapy and radiotherapy. He died six months after diagnosis. Metastatic tumors to the oral cavity are relatively uncommon. They are found most commonly in the mandible, and 70% of cases are adenocarcinoma-most commonly from breast and lung, followed by adrenals, kidneys, prostate, thyroid and colon. Mandibular mass is usually the first sign, then soft-tissue swelling, pain and paresthesias. Tissue proof is needed to confirm the diagnosis. The treatment depends on the nature of the primary, the degree of dissemination and the precise location. However, the prognosis is grim, with the mean survival after diagnosis being only about 6-7 months.     

Efficacy of body ventilation system for reducing strain in warm and hot climates

This study determined whether a torso-vest forced ambient air body ventilation system (BVS) reduced physiological strain during exercise-heat stress. Seven heat-acclimated volunteers attempted nine, 2-h treadmill walks at 200 W m⁻² in three environments, −40°C, 20% rh (HD), 35°C, 75% rh (HW), and 30°C, 50% rh, (WW) wearing the Army Combat Uniform, interceptor body armor (IBA) and Kevlar helmet. Three trials in each environment were BVS turned on (BVS_On), BVS turned off (BVS_Off), and no BVS (IBA). In HD, BVS_On significantly lowered core temperature (T _re), heart rate (HR), mean skin temperature (T _sk), mean torso skin temperature (T _torso), thermal sensation (TS), heat storage (S), and physiological strain index (PSI), versus BVS_Off and IBA (P < 0.05). For HW (n = 6), analyses were possible only through 60 min. Exercise tolerance time (min) during HW was significantly longer for BVS_On (116 ± 10 min) versus BVS_Off (95 ± 22 min) and IBA (96 ± 18 min) (P < 0.05). During HW, BVS_On lowered HR at 60 min versus IBA, T _sk from 30 to 60 min versus BVS_Off and IBA, and PSI from 45 to 60 min versus BVS_Off and at 60 min versus IBA (P < 0.05). BVS_On changes in T _re and HR were lower in HD and HW. During WW, BVS_On significantly lowered HR, T _sk, and T _torso versus BVS_Off and IBA (P < 0.05) during late exercise. Sweating rates were significantly lower for BVS_On versus BVS_Off and IBA in both HD and WW (P < 0.05), but not HW. These results indicate that BVS_On reduces physiological strain in all three environments by a similar amount; however, in hot-dry conditions the BVS_Off increases physiological strain.     

Sex comparison of hamstring structural and material properties

Background

Musculotendinous stiffness provides an estimate of resistance to joint perturbation, thus contributing to joint stability. Females demonstrate lesser hamstring stiffness than males, potentially contributing to the sex discrepancy in anterior cruciate ligament injury risk. However, it is unclear if the sex difference in hamstring stiffness is due to differences in muscle size or to inherent/material properties of the musculotendinous unit. It was hypothesized that hamstring stiffness, stress, strain, and elastic modulus would be greater in males than in females, and that hamstring stiffness would be positively correlated with muscle size.

Methods

Stiffness was assessed in 20 males and 20 females from the damping effect imposed by the hamstrings on oscillatory knee flexion/extension following joint perturbation. Hamstring length and change in length were estimated via motion capture, and hamstring cross-sectional area was estimated using ultrasound imaging. These characteristics were used to calculate hamstring material properties (i.e., stress, strain, and elastic modulus).

Findings

Stiffness was significantly greater in males than in females (P < 0.001). However, stress, strain, and elastic modulus did not differ across sex (P > 0.05). Stiffness was significantly correlated with cross-sectional area (r = 0.395, P = 0.039) and the linear combination of cross-sectional area and resting length (R² = 0.156, P = 0.043).

Interpretation

Male’s hamstrings possess a greater capacity for resisting changes in length imposed via joint perturbation from a structural perspective, but this property is similar across sex from a material perspective. Females demonstrate lesser hamstring stiffness compared to males in response to standardized loading conditions, indicating a compromised ability to resist changes in length associated with joint perturbation, and potentially contributing to the higher female ACL injury risk. However, the difference in hamstring stiffness is attributable in large part to differences in muscle size.     

Do Y geniculate neurons have greater contrast sensitivity than X geniculate neurons at all visual field locations?

Contrast sensitivities for gratings of different spatial frequencies drifting at 5.2 Hz were measured for X- and Y-type neurons of the cat's dorsal lateral geniculate nucleus. It was found that, for cells with neighboring receptive fields, the peak contrast sensitivities of Y-type cells were always greater than those of X-type cells. This greater contrast sensitivity of Y geniculate cells was found not to depend on the area of visual field in which the cells' receptive fields were located.     

Modulating the therapeutic activity of nanoparticle delivered paclitaxel by manipulating the hydrophobicity of prodrug conjugates

A series of paclitaxel prodrugs designed for formulation in lipophilic nanoparticles are described. The hydrophobicity of paclitaxel was increased by conjugating a succession of increasingly hydrophobic lipid anchors to the drug using succinate or diglycolate cross-linkers. The prodrugs were formulated in well defined block copolymer-stabilized nanoparticles. These nanoparticles were shown to have an elimination half-life of approximately 24 h in vivo. The rate at which the prodrug was released from the nanoparticles could be controlled by adjusting the hydrophobicity of the lipid anchor, resulting in release half-lives ranging from 1 to 24 h. The diglycolate and succinate cross-linked prodrugs were 1-2 orders of magnitude less potent than paclitaxel in vitro. Nanoparticle formulations of the succinate prodrugs showed no evidence of efficacy in HT29 human colorectal tumor xenograph models. Efficacy of diglycolate prodrug nanoparticles increased as the anchor hydrophobicity increased. Long circulating diglycolate prodrug nanoparticles provided significantly enhanced therapeutic activity over commercially formulated paclitaxel at the maximum tolerated dose.