The mechanism of action of tumor necrosis factor (TNF) on tumor vascularity--study using a transparent chamber

Effects of human recombinant TNF on the tumor blood vessels and on the thrombus formation were investigated in relation to its mode of antitumor action against Meth-A sarcoma transplanted in BALB/c mice. The extent of the blood vessel lesion was evaluated by using transparent chamber placed in the mouse skin. Bleeding, hyperemia and congestion were observed at 1-2h, 4-6h and 24h after TNF (1 X 10(4)U/mouse) administration, respectively. In contrast, no histological changes in the normal blood vessels were observed microscopically following TNF injection. Thrombus formation was evoked in the tumor vessels 4h after TNF injection. However, when thrombus formation was prevented by heparin, no difference was observed among antitumor action of TNF against Meth-A fibrosarcoma necrotic response and the rate of complete cure. These results suggest that the direct effects of TNF causing lesions in the tumor blood vessels plays an important role in its antitumor action.     

Endogenous tumor necrosis factor exerts its protective function intracellularly against the cytotoxicity of exogenous tumor necrosis factor.

Based on the findings that expression of endogenous tumor necrosis factor (enTNF), which is not present in TNF-susceptible cells, was generally observed in TNF-resistant cells and that TNF gene transfection gives rise to TNF resistance, the assumption was made that enTNF may be a protective protein against the cytotoxicity of exogenous TNF. However, it remains unknown whether the protection by enTNF is exerted in an intracellular or extracellular (autocrine) manner. We therefore transfected a nonsecretory human TNF gene (pTNF delta pro) into highly TNF-sensitive mouse tumorigenic fibroblasts (L-M cells) and investigated their TNF susceptibility. The transfectants expressed enTNF which was not secreted into the medium and acquired an appreciable degree of resistance to exogenous TNF. A significant increase in the manganous superoxide dismutase level was also noted in the transfectants. These findings suggest that enTNF exerts its protective function intracellularly by inducing manganous superoxide dismutase production.     

Early experience with a novel plaque excision system for the treatment of complex coronary lesions.

The use of directional coronary atherectomy (DCA) in current practice has been limited. The SilverHawk System is a newly developed plaque excision device that aims to overcome the drawbacks of prior DCA platforms. The device was evaluated in a porcine coronary model and in a series of patients. Procedural variables along with outcomes were reviewed. Quantitative angiography (QCA) was performed and excised tissue fragments were weighed and examined histologically. In porcine cases, pretreatment MLD increased from 0.51 +/- 0.26 to 2.36 +/- 0.59 mm postdebulking and 19.9 +/- 7.6 mg of tissue was retrieved. In human cases, pretreatment MLD increased from 0.8 +/- 0.4 to 2.2 +/- 0.5 mm postdebulking and 15.2 +/- 7.8 mg of tissue was retrieved without complications. These data show that the SilverHawk System may offer significant utility in treating a wide variety of complex coronary lesions.     

Moderate acute rejection detected during annual catheterization in pediatric heart transplant recipients.

BACKGROUND: Acute rejection commonly occurs within the first year after heart transplantation, and then decreases in frequency with time. Recently, the long-term utility of endomyocardial biopsy during routine annual catheterization has been questioned. The purpose of this study was to retrospectively review the prevalence of biopsy-proven rejection during routine annual catheterization in our patient population, determine whether biopsies late after transplant are useful, and identify factors that correlate with late unsuspected rejection. METHODS: Biopsy results from the annual catheterization were evaluated from 1986 to August 2000. The prevalence of moderate rejection was evaluated and compared with the patient's immunosuppressive regimen; the prevalence of late rejection; and how late rejection correlated with recipient age, number of first-year rejections and presence of sub-therapeutic cyclosporine. RESULTS: A total of 1108 biopsies were performed in 269 children with a mean follow-up of 5 +/- 3 years (median 5 years, range 1 to 11 years). Three-drug immunosuppressive therapy, including steroids, was used in 93 patients. There was a persistent 8% to 10% prevalence of moderate rejection at up to 10 years post-transplantation. Moderate rejection was more likely in patients: (1). on 3-drug immunosuppressive therapy; (2). with a recipient age >1 year; and (3). with a relatively lower cyclosporine level. CONCLUSIONS: These data suggest that continued surveillance of pediatric transplant patients for acute rejection is indicated for long-term follow-up.     

The Hunger Games: Homeostatic State-Dependent Fluctuations in Disinhibition Measured with a Novel Gamified Test Battery

Food homeostatic states (hunger and satiety) influence the cognitive systems regulating impulsive responses, but the direction and specific mechanisms involved in this effect remain elusive. We examined how fasting, and satiety, affect cognitive mechanisms underpinning disinhibition using a novel framework and a gamified test-battery. Thirty-four participants completed the test-battery measuring three cognitive facets of disinhibition: attentional control, information gathering and monitoring of feedback, across two experimental sessions: one after overnight fasting and another after a standardised meal. Homeostatic state was assessed using subjective self-reports and biological markers (i.e., blood-derived liver-expressed antimicrobial protein 2 (LEAP-2), insulin and leptin). We found that participants who experienced greater subjective hunger during the satiety session were more impulsive in the information gathering task; results were not confounded by changes in mood or anxiety. Homeostatic state did not significantly influence disinhibition mechanisms linked to attentional control or feedback monitoring. However, we found a significant interaction between homeostatic state and LEAP-2 on attentional control, with higher LEAP-2 associated with faster reaction times in the fasted condition only. Our findings indicate lingering hunger after eating increases impulsive behaviour via reduced information gathering. These findings identify a novel mechanism that may underpin the tendency to overeat and/or engage in broader impulsive behaviours.     

Assessment of MUSASHI 1 and MUSASHI 2 expression in spermatozoa and testicular tissue

MUSASHI (MSI) family plays the main role in the spermatogenesis process. The purpose of this study was the assessment of sperm MSI1 and MSI2, and sperm functional tests in infertile men (n = 30) with varicocele and fertile men (n = 30). Furthermore, MSI1 and MSI2 proteins were assessed in testicular tissue of azoospermic men (n = 9) as well as epididymal spermatozoa and testis of mice. Expression of MSI1 and MSI2 was assessed at RNA and protein levels in human spermatozoa. Sperm concentration and motility were significantly lower, while abnormal sperm morphology, lipid peroxidation, DNA fragmentation and protamine deficiency were significantly higher in men with varicocele compared to fertile individuals. Any significant difference was not observed in the expression of MSI1 and MSI2 mRNA between the two groups. Unlike MSI1 protein that was not detectable in humans, the relative expression of MSI2 protein was similar in varicocele and fertile individuals. The expression level of both Msi1 and Msi2 proteins was also observable in mouse spermatozoa. No significant relationship was observed between sperm functional parameters with expression of these genes. The data of this study demonstrated that although MSI1 and MSI2 play important roles during spermatogenesis, their relative expression in spermatozoa was not affected by varicocele.     

What is the appropriate aganglionic bowel length on contrast enema for attempting single stage transanal endorectal pull-through in Hirschsprung disease?

PurposeTo identify influence of different values of age and abnormal bowel length in HD patients selected for single stage TERPT which affects the technique of surgery.MethodsThis observational study was carried out for over 2.5 years. All children younger than 14 years old with clinical suspicion for HD, typical transitional zone (TZ) on contrast enema (CE) distal to splenic flexure, preoperative diagnosis approved by full thickness biopsy, no previous surgical history and no urgency were included. The distance between the anus and TZ was considered as aganglionic length on CE. Biopsy was taken from distal to proximal of resected bowel to reach circumferentially normal innervated bowel. Paired sample Student's t-test, Pearson correlation test, receiver operating characteristic (ROC) analysis were performed.ResultsForty-eight patients were enrolled in this study. Measured mean for aganglionic bowel length on CE and pathology were 33.5 ± 17.1 cm and 56.8 ± 33.5 cm, respectively (p < 0.01). Correlation coefficient (R) and coefficient of determination (R2) were 0.632 and 40%, respectively (p < 0.01). The difference between radiologic and pathologic measurements in females was higher than males (mean: 29.3 vs 21.9 cm) but was not statistically significant (p = 0.75). There was statistically significant difference between CE and pathologic results in the infants younger than 10 months (p = .004). Abnormal bowel length equal to 52 cm predicted requirement of laparoscopy assistance/laparotomy with 75% sensitivity and 85% specificity.ConclusionOur investigation showed it is safe to attempt for single stage TERPT when aganglionic length on CE is less than 52 cm and the child with HD is older than 10 months. Chance of requiring additional laparotomy or laparoscopy assistance is low in these patients.Type of studyStudy of diagnostic test.Level of evidenceLevel II.     

Diminished expression of the α5β1 integrin (fibronectin receptor) by invasive clones of a human follicular thyroid cancer cell line

Altered adhesion plaques have been observed in transformed cell lines and are associated with enhanced metastatic potential. The prototypical adhesion plaque is formed by 51 fibronectin receptors (FnRs) interacting with the cellular actin network. We have found differences in the actin networks of noninvasive (FTC-133) and invasive (FTC-236, FTC-238) clones of a human follicular thyroid cancer cell line. Furthermore, thyroid-stimulating hormone (TSH) induces stress fibers in FTC-133. In order to investigate differences in adhesion plaques, expression of fibronectin (FN) and its receptor by these cells was analyzed. For these studies FTC-133, FTC-236, and FTC-238 were cultured in serum-depleted DME-H21 medium for 24 hours before the addition of TSH 30 mU/ml. No quantitative differences were noted in FN expression on Western blot in either the conditioned medium or cellular extracts. Western blots and immunohistochemical studies indicated that TSH induced secretion of FN only in FTC-133. Flow cytometry with an 5 antibody demonstrated a 52% and 45% reduction (p<0.01) in expression of FnR by FTC-236 and FTC-238, respectively, compared to FTC-133; this finding was supported by immunohistochemistry results. TSH treatment did not alter FnR expression. From these studies, we conclude that invasive clones of FTC decrease their expression of FnRs without changing their expression of FN. Furthermore, TSH treatment may promote FN secretion by FTC-133, although it does not seem to affect FnR or absolute FN expression. The diminished expression of FnR adhesion plaques may enhance metastatic potential in some follicular thyroid cancers.

---

Resumen Se han observado placas adhesivas alteradas en líneas celulares transformadas en asociación con un potencial metastásico incrementado. La prototípica placa adhesiva se forma por la interacción de receptores 5-1 con la trama celular de actina. Hemos encontrado diferencias en las tramas de actina en clones no invasivos (FTC-133) e invasivos (FTC-236, FTC-238) de una línea celular de cáncer folicular de tiroides.Además, la TSH induce líneas de estrés en FTC-133. Con el objeto de investigar las diferencias en las placas adhesivas, se hizo el análisis de la expresión de fibronectina (FN) y sus receptores en tales células.Para estos estudios se hizo el cultivo de FTC-133, FTC-236 y FTC-238, en sueros depletados de DME-H21 por 24 horas anteriores a la adición de 30 mU/ml TSH por 24 horas. No se observaron diferencias cuantitativas en la expresion de FN o en el Western blot ni en los medios condicionados ni en los extractos celulares. Los Western blots y los estudios inmunohistoquímicos indicaron que la TSH induce la secreción de FN sólo en FTC-133. La citometría de flujo con un anticuerpo 5 demostró una reducción de 52% y 45% (p<0.01) en la expresión de FnR por FTC-236 y FT-238, respectivamente, en comparación con FTC-133; este hallazgo fue verificado por inmuno-histoquímica. El tratamiento con TSH no alteró la expresón FnR. Con base en estos estudios, es nuestra conclusión que los clones invasivos de FTC disminuyen la expresión de FnR sin cambiar su expresión de FN. Además, el tratamiento con TSH puede promover la secreciòn de FN por FTC-133, aunque no parece afectar la expresión de FnR o la expresión absoluta de FN. Esta expresión disminuída de las placas adhesivas FnR puede incrementar el potencial metastásico en algunos cánceres foliculares de tiroides.

---

Résumé On a observé des altérations des plaques d'adhésion dans certaines lignées cellulaires transformées, et celles-ci semblent être associées à un potentiel métastatique augmenté. La plaque d'adhésion prototypique est formée par des récepteurs 51 de fibronectine (FnR) qui agissent sur le réseau cellulaire d'actine. Nous avons trouvé une différence entre les réseaux d'actine des clones noninvasifs (FTC-133) et invasifs (FTC-236, FTC-238) des lignées cellulaires dans le cancer folliculaire de la thyroïde chez l'homme. La TSH induit des fibres de stress dans le FTC-133. Afin d'évaluer les différences dans les plaques d'adhésion, l'expression de la fibronectine (FN) et de son récepteur ont été analysées. Pour ces études, les clones FTC-133, FTC-236 et FTC-238 ont été mis en culture dans le milieu DME-H21 dépourvu en sérum pendant 24 heures avant l'addition de 30 mU/ml de TSH/24 heures. II n'y avait aucune différence quantitative dans l'expression FN sur Western blot que ce soit sur le milieu ainsi conditionné ou sur les extraits cellulaires. Les Western blots et les études immunohistochimiques ont indiqué que la TSH n'induisait la sécrétion de FN que dans la lignée FTC-133. La cytométrie de flux avec l'anticorps 5 a démontré une réduction respectivement de 52% et de 45% (p<0.01) dans l'expression de FnR par les clones FTC-236 et FTC-238, comparé au FTC-133. Cette donnée a été confirmée par l'immunohistochimie. A partir de ces études, nous concluons que les clones d'invasion de FTC diminuent leur expression en FnR sans changer leur expression de FN. De plus, un traitement par la TSH peut induire la sécrétion de FN par le clone FTC-133 alors qu'il ne semble pas influencer le FnR ou l'expression FN. L'expression diminuée des plaques d'adhésion FnR semble potentialiser les métastases dans certains cancers de la thyroïde.

     

Social Contact Patterns Associated With Tuberculosis: A Case-control Study in Southwest Iran

ObjectivesTuberculosis (TB) is a major public health concern worldwide. Social contact patterns can affect the epidemiology and risk of airborne diseases such as TB. This study was designed to investigate the social contact patterns associated with TB.MethodsIn this case-control study, groups of participants with and without TB were matched by age and sex. Participants reported the nature, location, frequency, and average duration of social contacts over 1 month. The duration and number of social and spatial contacts were compared between groups using the chi-square test and the t-test. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to quantify the relationship between social contact time and TB status. Data were analyzed using Stata version 11 statistical software. A p-value of <0.05 was considered to indicate statistical significance.ResultsIn this study, 80 patients with TB and 172 control participants were included, and a total of 3545 social contacts were registered. Social contact with family members (OR, 1.72; 95% CI, 1.10 to 2.40), contact with a person with TB (OR, 1.53; 95% CI, 1.16 to 2.01), and contact at the participant’s home (OR, 1.42; 95% CI, 1.19 to 1.82) were significantly associated with TB status.ConclusionsThe duration of long-term social contact, rather than the number of contacts, may be the main contact-related factor associated with TB transmission in this population. The focus of contact-tracing efforts should be on finding and treating both family members and long-term contacts in non-household settings.