The cytotoxic effect of palytoxin on Caco-2 cells hinders their use for in vitro absorption studies

Palytoxin (PLTX), found in Palythoa zoanthids and Ostreopsis dinoflagellates, has also been detected in crabs and fish, through which it can enter into the food chain. Indeed, PLTX is considered the causative agent of several cases of human seafood poisoning resulting in systemic symptoms. Available epidemiological data on PLTX human toxicity suggest that the intestinal tract may be one of its in vivo targets and its potential site of access into the bloodstream. Hence, the purpose of this study was to investigate the suitability of the human intestinal Caco-2 cell line for evaluating PLTX oral absorption. A detailed analysis of PLTX cytotoxicity revealed a high sensitivity of Caco-2 cells: 4h toxin exposure reduced mitochondrial activity (MTT assay, EC(50) of 8.9±3.7×10(-12)M), cell density (SRB assay, EC(50) of 2.0±0.6×10(-11)M) and membrane integrity (LDH release, EC(50) of 4.5±1.4×10(-9)M and PI uptake, EC(50) of 1.0±0.8×10(-8)M). After low PLTX concentration (1.0×10(-11)M) exposure for 1-8h, followed by 24h recovery time in toxin-free medium, cell density reduction was only partially reversible. These results indicate that, due to the high susceptibility to PLTX cytotoxic effects, Caco-2 cells do not represent an appropriate and reliable model for investigating intestinal barrier permeation by this toxin.     

The potential value of early screening for neurological deficits in participants in certain sports

Physicians occasionally encounter the punch-drunk syndrome among boxers after longlasting careers characterized by blows to the head. The list of sports leading to punch-drunk syndrome is rapidly increasing, making it a notable public health problem. A lack of specific findings leads to defects in reporting the condition, and consequently to delay in treatment. Although the rigorous enforcement of sport rules and constant improvements of sporting equipment have decreased the occurrence of the syndrome, early detection of punch-drunk syndrome is crucial and would have comprehensive benefits. Two groups of signs and symptoms can be identified: dementia and Parkinsonism. A prompt diagnosis with a correct classification of the suspected cases is crucial. Therefore, we offer an overview of the symptomatology as well as proposing the introduction of a screening method among risk groups based on generic and minute neurological examination and dementia testing.     

Genetic analysis of 7 medieval skeletons from the Aragonese Pyrenees

Aim

To perform a genetic characterization of 7 skeletons from medieval age found in a burial site in the Aragonese Pyrenees.

Methods

Allele frequencies of autosomal short tandem repeats (STR) loci were determined by 3 different STR systems. Mitochondrial DNA (mtDNA) and Y-chromosome haplogroups were determined by sequencing of the hypervariable segment 1 of mtDNA and typing of phylogenetic Y chromosome single nucleotide polymorphisms (Y-SNP) markers, respectively. Possible familial relationships were also investigated.

Results

Complete or partial STR profiles were obtained in 3 of the 7 samples. Mitochondrial DNA haplogroup was determined in 6 samples, with 5 of them corresponding to the haplogroup H and 1 to the haplogroup U5a. Y-chromosome haplogroup was determined in 2 samples, corresponding to the haplogroup R. In one of them, the sub-branch R1b1b2 was determined. mtDNA sequences indicated that some of the individuals could be maternally related, while STR profiles indicated no direct family relationships.

Conclusions

Despite the antiquity of the samples and great difficulty that genetic analyses entail, the combined use of autosomal STR markers, Y-chromosome informative SNPs, and mtDNA sequences allowed us to genotype a group of skeletons from the medieval age.The spectrum of disciplines that have the ability to detect and analyze ancient molecules has increased substantially and contributed to the capabilities of palaeobiology and genetic anthropology. The parts of human remains that are best preserved after a long period of time are bones and teeth, which are most frequently used for molecular analyses. Immediately after death and in the transition from a living organism to a fossil, some changes occur to the cadaver and its circumstances (taphonomic processes) and others take place inside the bone (diagenetic processes). The type and extent of diagenetic processes are influenced by several factors (1,2) and it has been stated that at burial all bones have similar diagenetic parameters, but when the bones are recovered these values may widely differ (1). A single parameter or combination of parameters that better predicts the degree of preservation of DNA molecules has long been sought for. Much attention has been paid to the preservation of protein in bone, mainly collagen, which is the most abundant protein in bony tissues; but there is no consensus on the possible relation of collagen with the DNA yield (3-7).Autosomal short tandem repeats (STR) are forensically relevant genetic markers that offer the highest discrimination power and thus are the first choice for genetic identification in forensic case work. However, when it comes to ancient samples problems such as degradation, low copy number, and inhibition (8) very often preclude the analysis of relatively large fragments of nuclear DNA. Therefore, for analyzing degraded DNA, a more successful method has been mtDNA typing, due to its high copy number (1000-10 000 copies) per cell. Although autosomal STR typing is still not comparable to mtDNA typing, with the advent of highly robust commercial kits using a mini-STR format (9,10) it has become more effective than ever and is a valuable tool for molecular anthropology, archeology, and forensic genetics.The aim of this study was to genetically characterize 7 skeletons found in a medieval burial site in the Aragonese Pyrenees, as well as to assess the performance of the currently available autosomal STR systems to genotype difficult samples.     

Oxidative stress in soleus and extensor digitorum longus (EDL) muscles of spontaneously hypertensive rats

Systemic diseases affect skeletal muscle, and inflammation and oxidative stress are some of the involved mechanisms. There is scarce information about the effects of essential hypertension on skeletal muscle. The soleus and extensor digitorum longus (EDL) muscles of spontaneously hypertensive rats (SHR) were studied compared to control Wistar Kyoto (WKY) rats. The levels of nitrite and nitrate in micromol/mg-protein; endothelial (eNOS), neuronal (nNOS), and inducible (iNOS) nitric oxide synthases, nitrotyrosine and tumour necrosis factor alpha (TNF-alpha) in ng/mg-protein were determined. Compared with controls, the SHR showed increased levels of nitrotyrosine (soleus 24.4 +/- 5.0 vs. 3.3 +/- 0.3, p<0.001; EDL 20.2 +/- 4.3 vs. 4.5 +/- 0.4, p<0.0037), iNOS (soleus 26.6 +/- 3.7 vs. 8.3 +/- 0.9; EDL 21.3 +/- 3.7 vs. 11.0 +/- 0.8, both p<0.0001) and TNF-alpha (soleus 2.2 +/- 0.5 vs. 0.6 +/- 0.1, p<0.05; EDL 1.9 +/- 0.2 vs. 0.6 +/- 0.1, p<0.02). A decrease of eNOS was found in soleus muscle (20.6 +/- 1.4 vs. 30.3 +/- 1.2, p<0.00001); of nNOS (soleus 16.8 +/- 1.4 vs. 20.7 +/- 1.8, p< 0.05; EDL 13.6 +/- 1.3 vs. 21.9 +/- 1.8, p<.005) and nitrite in EDL (5.8 +/- 0.3 vs. 7.1 +/- 0.5, p<0.026).There was a positive correlation between TNF-alpha vs. nitrotyrosine in soleus (r=0.798; p<0.031) and a tendency in EDL (r=0.739; p=0.059); iNOS vs. nitrotyrosine (soleus: r=0.908; p<0.0001; EDL: r=0.707; p<0.01), a tendency between TNF-alpha and iNOS (EDL: r=0.736; p<0.059); and a negative correlation between eNOS vs. nitrotyrosine in soleus muscle (r=-0.816; p<0.0012). In conclusion, in skeletal muscles of SHR an inflammatory process was found evidenced by the increase in TNF-alpha, nitrotyrosine and iNOS. The decreased levels of constitutive synthases, together with the higher level of iNOS, are indicative of endothelial dysfunction.     

Schwann cell chondroitin sulfate proteoglycan inhibits dorsal root ganglion neuron neurite outgrowth and substrate specificity via a soma and not a growth cone mechanism

Sensory axons do not regenerate into or within the spinal cord because of the presence of the axon regeneration inhibitor chondroitin sulfate proteoglycan (CSPG) on activated astrocytes. In the peripheral nervous system, CSPG associated with denervated Schwann cells retards axon regeneration, but regeneration occurs because the balance of regenerating, inhibiting, and promoting factors favors regeneration. The present experiments were aimed at determining the mechanism by which Schwann cells inhibit adult human dorsal root ganglia (H‐DRG) neuron growth cone elongation and substrate specificity, restricting the growth cones to Schwann cell membranes and inhibiting their growth onto a poly‐l‐lysine/laminin substrate. Neurites of H‐DRG neurons free of soma contact with Schwann cells, or after the Schwann cell membranes' CSPG had been digested, were 11.1‐fold longer than those of neurons in soma contact with untreated Schwann cells. Growth cones of DRG neuron somas without Schwann cell CSPG showed no outgrowth inhibition or substrate specificity. These results indicate that the Schwann cell CSPG influences act via contact with neuron somas but not growth cones. These results suggest that eliminating CSPG associated with Schwann cells within DRG in vivo will make the neurons' growth cones insensitive to the regeneration inhibitory influences of CSPG, allowing them to regenerate through the dorsal root entry zone and into and within the spinal cord, where they can establish appropriate and functional synaptic connections. © 2009 Wiley‐Liss, Inc.     

Clinical and genetic characteristics of Mexican Huntington's disease patients

We report the characteristics of 691 Mexican patients with Huntington's disease (HD). These patients, representing 401 families, constitute the largest series of Mexican HD cases as yet described in the literature. We found the clinical characteristics of these patients to be similar to those of other populations, but we observed a higher frequency of infantile cases, a shorter disease duration and a lower suicide rate. In 626 cases, for which molecular analyses were available, CAG‐trinucleotide expansion size ranged from 37–106 repeats. The large number of CAG repeats (19.04 ± 3.02) in normal alleles and the presence of new mutations suggest that the overall prevalence of HD in the Mexican population could be expected to be within range of, or higher than, that reported for Europeans. © 2009 Movement Disorder Society     

Laparoscopic Radical Nephrectomy for Renal Masses 7 Centimeters or Larger

Objective:

To report our operative experience and oncologic outcomes for the laparoscopic management of large renal tumors.

Methods:

All laparoscopic and hand-assisted laparoscopic radical nephrectomies performed at our institution were reviewed. Thirty patients with tumors ≥7cm and a pathologic diagnosis of renal cell carcinoma were included.

Results:

Mean operative time was 175.7±24.5 minutes, and mean estimated blood loss was 275.5±165.8 mL. No case required conversion to open radical nephrectomy. The mean hospital stay was 2.4±1.6 days. Four patients (13%) had minor complications. Of the 30 tumors, 18 were pathologic stage T2, 9 were stage T3a, 2 were stage T3b, and one was stage T4. At a mean follow-up of 30 months (range, 10 to 70), 22 patients (73%) were alive without evidence of recurrence, and 5 patients (17%) were alive with disease. One patient (3%) died of complications related to renal cell carcinoma, and 2 patients (7%) died from other causes. Overall survival was 90%, cancer-specific survival was 97%, and recurrence-free survival was 80%.

Conclusion:

Laparoscopic radical nephrectomy for large tumors is a technically challenging operation. However, in experienced hands, it is a reasonable therapeutic option for the management of larger RCC neoplasms.     

Outdated and incomplete: a review of thyroid cancer on the World Wide Web.

OBJECTIVE: To evaluate the most frequently searched thyroid cancer websites for completeness, accuracy, and consumer friendliness. DESIGN: The 50 most popular thyroid cancer websites were evaluated using a novel instrument developed by a Delphi panel of endocrine experts and based on practice guidelines. Each website received independent scores for disease-specific information and a final quality score. Quality was related to website demographics using the Student t test, chi-square, and ANOVA analyses. MAIN OUTCOMES: Interrater reliability was excellent (kappa = 0.81). Most websites were not specific to thyroid cancer alone (72%), contained advertisements (72%), lacked references (66%), and were privately sponsored (50%). Only 38% had been updated within 2 years. "Government" and "Non-Profit" websites were the most consumer friendly. Mean quality score of medical content was 38%, with websites receiving the highest score in "Anatomy/Physiology" (55%) and lowest in "Surgery" (29%). Low quality score was attributed to information deficiency rather than inaccuracy. On univariate analysis, no significant associations were found between quality score and country of origin, currency, sponsorship, authorship, administration, advertisements, or references. CONCLUSIONS: Thyroid cancer websites are out of date and incomplete, lacking important information sought by patients, particularly surgical information. An accurate, comprehensive, easily available, and patient-oriented thyroid cancer Internet resource is needed for patients.