Neurological deficit as a presentation of occult metastatic thyroid carcinoma

Three cases of occult metastatic thyroid carcinoma presenting with neurological deficits are reviewed. In each case the patient's initial presentation was with symptoms of neurological deficiency secondary to a spinal cord compression. All patients received a combination of surgery, external beam radiotherapy and postoperative thyroxine treatment. Two of the three patients are alive and well, able to mobilize with minor neurological dysfunction. The diagnosis and management of the patients, as well as their outcomes are reviewed, with a discussion on further management issues alongside a review of the current published work.     

Human S-cone vision: relationship between perceptive field and ganglion cell dendritic field

We measured the S-cone contrast threshold for stimuli of different size modulated along the white -90 deg direction in the isoluminant plane of DKL color space. The stimuli were presented at eccentricities of 5-30 deg in the horizontal temporal retinal meridian. Ricco's area of complete spatial summation was estimated using a bilinear fit of the log threshold/log area function. Ricco's area increased towards the retinal periphery to include an increasing number of S-cones while remaining 1.6-1.8 times larger than the dendritic field area of the small bistratified and parasol retinal ganglion cells. Assuming constant coverage factor by the dendritic field, Ricco's area incorporated a constant number (three to four) of small bistratified cells. It was also found that the threshold contrast for stimuli that matched Ricco's area was constant across the studied eccentricity range, similar to previous findings for achromatic vision. Our data support the point of view that this invariance is the result of a constant number of cells involved in stimulus detection.     

Percutaneous renal access simulators

Percutaneous renal access is an integral step in percutaneous renal drainage and percutaneous nephrolithotomy. Urologists are increasingly obtaining access themselves, as this eliminates reliance on a second "surgeon" and increases flexibility with respect to procedure timing and the location of the access tract. Surprisingly few models have been developed to train urologists in percutaneous renal access. Harvested porcine kidney/ureter units mounted so they can be viewed radiographically and accessed by needle puncture through material simulating the human flank have been incorporated into two models. The PERC Mentor (Simbionix; Lod, Israel) is a virtual-reality simulator developed specifically for training in percutaneous renal puncture. Hands-on intraoperative training continues to be the primary method for learning percutaneous renal access. However, bench model and simulator-based education offer a useful adjunct.     

Androgen receptor (CAG)n polymorphism and androgen levels in women with systemic lupus erythematosus and healthy controls

Systemic lupus erythematosus (SLE) is an autoimmune disorder that affects mainly females. Therefore, interrelations between the reproductive and immune system have been assumed. Considering the complex influence of hormones and receptors, we aimed to investigate the influence of androgens and androgen receptor (AR) polymorphism in women with SLE. One hundred and sixteen patients and 44 healthy women were investigated. Testosterone, sex hormone-binding globulin (SHBG), dehydroepiandrosterone-sulphate (DHEAS) concentrations and AR (CAG)n polymorphism were determined. SLE patients had significantly lower levels of total and free testosterone and DHEAS in comparison with the controls. No differences in the CAG repeat length between the groups were established. Women with two alleles carrying more than 22 CAG repeats had significantly higher levels of SHBG (101.51 ± 61.81 vs. 69.22 ± 45.93 nmol/l, p = 0.015) and DHEAS (3.11 ± 2.65 vs. 2.11 ± 3.06 μmol/l, p = 0.007) and a tendency to higher testosterone concentrations (2.35 ± 2.10 vs. 1.71 ± 1.70 nmol/l, p = 0.056) in comparison with other women. The CAG repeat length in the relatively longer (CAG)n allele was inversely related to the Systemic Lupus International Collaborating Clinics/ACR index (r = ?0.258, p = 0.009). In conclusion, the androgen receptor (CAG)n polymorphism is not related to the development of SLE, but it could modulate the severity of the lupus chronic damages as well as the androgen levels in women.     

Activation of PAR1 in the lateral hypothalamus of rats enhances food intake and REMS through CB1R

The activation of protease-activated receptor 1 (PAR1) in cultured rat hippocampal neurons triggers synaptic retrograde signaling through the endocannabinoid 2-arachidonoylglycerol, thereby activating the cannabinoid receptor 1 (CB1R). CB1R is a metabotropic receptor activated by marihuana and endocannabinoids that suppresses neurotransmitter release. Also, activation of the CB1R increases rapid eye movement sleep (REMS) and food intake. The lateral hypothalamus is a crucial structure to modulate both feeding and waking. To evaluate the effect of PAR1 stimulation in the lateral hypothalamus on food intake and on the sleep-waking cycle, we implanted rats with electrodes, for recording sleep, and cannulae, to administer S1820, a selective PAR1 agonist peptide, bilaterally into the lateral hypothalamus. To determine whether the effects induced by PAR1 stimulation were mediated by CB1R activation, we administered AM251, a CB1R inverse agonist, to block S1820 effects. Our results show that the stimulation of PAR1 into the lateral hypothalamus increases both food intake and REMS and such effects were prevented by AM251, indicating that PAR1 modulates both food intake and the sleep-waking cycle, in the lateral hypothalamus, through CB1R activation. This study shows novel behavioral changes induced by PAR1 activation and further supports the notion that endocannabinoids are food intake and REMS promoters.     

Variations in blood supply to the anterior interventricular septum: incidence and possible clinical importance.

The variations of the blood supply to the anterior interventricular septum in a series of 1,089 patients are described. Special attention has been given to variations and frequency of occurrence of the septal perforators originating from the left anterior descending artery. These variations may have clinical significance in this era of coronary angioplasty and coronary bypass surgery.