Changes in retinoblastoma gene expression during cervical cancer progression

The role of tumour suppressor genes in the development of human cancers has been studied extensively. In viral carcinogenesis, the inactivation of suppressor proteins such as retinoblastoma (pRb) and p53, and cellular oncogenes overexpression, such as c-myc, has been the subject of a number of investigations. In uterine-cervix carcinomas, where high-risk human papillomavirus (HPV) plays an important role, pRb and p53 are inactivated by E7 and E6 viral oncoproteins, respectively. However, little is known about the in situ expression of some of these proteins in pre-malignant and malignant cervical tissues. On the other hand, it has also been demonstrated that c-myc is involved in cervical carcinogenesis, and that pRb participates in the control of c-myc gene expression. By using immunostaining techniques, we investigated pRb immunodetection pattern in normal tissues, squamous intraepithelial lesions (SILs) and invasive carcinomas from the uterine cervix. Our data show low pRb detection in both normal cervical tissue and invasive lesions, but a higher expression in SILs. C-Myc protein was observed in most of the cellular nuclei of the invasive lesions, while in SILs was low. These findings indicate a heterogeneous pRb immunostaining during the different stages of cervical carcinogenesis, and suggest that this staining pattern could be a common feature implicated in the pathogenesis of uterine-cervix carcinoma.     

Activation of AMP-activated protein kinase in the liver: a new strategy for the management of metabolic hepatic disorders

It is now becoming evident that the liver has an important role in the control of whole body metabolism of energy nutrients. In this review, we focus on recent findings showing that AMP-activated protein kinase (AMPK) plays a major role in the control of hepatic metabolism. AMPK integrates nutritional and hormonal signals to promote energy balance by switching on catabolic pathways and switching off ATP-consuming pathways, both by short-term effects on phosphorylation of regulatory proteins and by long-term effects on gene expression. Activation of AMPK in the liver leads to the stimulation of fatty acid oxidation and inhibition of lipogenesis, glucose production and protein synthesis. Medical interest in the AMPK system has recently increased with the demonstration that AMPK could mediate some of the effects of the fat cell-derived adiponectin and the antidiabetic drugs metformin and thiazolidinediones. These findings reinforce the idea that pharmacological activation of AMPK may provide, through signalling and metabolic and gene expression effects, a new strategy for the management of metabolic hepatic disorders linked to type 2 diabetes and obesity.     

Biliopancreatic Diversion: 170 patients in a 7-year follow-up

During the past 7 years, 170 morbidly obese patients have been subjected to a biliopancreatic diversion. Mean weight loss achieved over 2 years was greater than 70% of excess weight and was maintained. Early complications were rare. The most common side-effects are discussed. The re-operation rate because of these side-effects was 7%. Eating normal meals, together with a stable weight loss, has provided these patients with a better quality of life.     

Differentiation of proton-pumping activity in cultured renal inner medullary collecting duct cells

Cultured inner medullary collecting duct (IMCD) cells have been shown to secrete protons (H⁺) by two mechanisms: anN-ethylmaleimide-and dicyclohexyl-carbodiimide-sensitive electrogenic H⁺-ATPase or H⁺ pump, and an amiloride-sensitive, secondary active Na⁺/H⁺ exchanger. These cells also express Cl^–/HCO₃ ^– exchange and carbonic anhydrase activity in common with other renal epithelial cells involved in acid-base transport. Video fluorescence microscopy of individual cells using 2, 7-biscarboxyethyl-5(6)-carboxyfluorescein has demonstrated that adjacent-cultured IMCD cells show substantial functional intercellular heterogeneity. The development of H⁺-pumping activity is associated with high-baseline intracellular pH and peanut agglutinin (PNA) affinity, and loss of mitotic activity and of Na⁺/H⁺ exchange. The H⁺-pumping activity may be further enhanced by removal of fetal calf serum for 6–54 h or by selecting cells with high PNA affinity. IMCD cells in their most differentiated state form domes, which consistently showed the highest rates of H⁺-pumping activity, as well as high affinity for peanut lectin. When IMCD were plated at low density, domes developed relatively late (2–4 weeks), at which time cells located in the center of nests of contiguously growing cells were quiescent and showed H⁺-pumping activity but no Na⁺/H⁺ exchange. On the other hand, dense plating was associated with early development of domes (end of 1st week), at which time adjacent cells showed a high mitotic activity and Na⁺/H⁺ exchange, but no H⁺-pumping activity. We speculate that differentiation of IMCD cells results in the development of cell polarity. This could include either loss of the apical Na⁺/H⁺-exchange activity, or localization of this exchanger only to the basolateral membrane, while the H⁺ pump differentiates at the apical membrane.     

电解可脱性铂弹簧圈栓塞治疗颅内动脉瘤26例

目的：报告使用电解可脱性钱弹簧圈（Ｇｕｇｌｉｅｌｍｉ ｄｅｔａｃｈａｂｌｅ ｃｏｉｌ,ＧＤＣ）栓塞治疗颅内动脉瘤的情况。方法：气管内插管全订和肝素抗凝下,使用Ｓｅｌｄｉｎｇｅｒ’ｓ技术,经Ｔｒａｃｋｅｒ微导管放置ＧＤＣ栓塞颅内动脉瘤。成功栓塞２６例３１个颅内动脉瘤,其中２７个为１００％栓塞,３个为９５％,１个为９０％。３个９５％栓塞均为宽颈动脉瘤。１个９０％栓塞者,为Ｈｕｎｔ分级Ⅳ级,存在严重脑血     

Measurement of the vasoconstrictive substances endothelin,angiotensin II,and thromboxane B2 in cold storage solution can reveal previous renal ischemic insults

In a rat model, the left kidney was subjected to 60 min of normothermic ischemia followed by 15 min of reperfusion, whereas the right kidney, serving as a paired control, was not rendered ischemic. Both kidneys were then perfused in situ with either Euro-Collins (EC) solution (n=12) or University of Wisconsin (UW) solution (n=6) for 10 min. Each kidney was then harvested and stored at 4°C in its respective solution. After 24 and 48 h of cold storage, the following vasoactive substances were measured in the preservation media: endothelin (ET), angiotensin II (A-II), thromboxane (B₂) (TxB₂), and prostaglandin I₂ (PGI₂). After 24 h in EC solution, left kidneys uniformly produced significantly higher concentrations of each vasoactive substance than right kidneys: ET 1.64±0.3 pg/ml vs 0.82±0.1 pg/ml (P0.009); A-II 20.8±6.2 pg/ml vs 7.75+2.3 pg/ml (P0.007); TxB₂ 100.8±17.7 pg/ml vs 40.1±11.7 pg/ml (P0.04); PGI₂ 638.3±41.1 pg/ml vs 318.3±36.4 pg/ml (P0.001), respectively. At 48 h, a similar pattern of results was obtained as the kidney continued to produce TxB₂ and prostacyclins during the 24–48 h period. In the UW solution, basal levels of ET and A-II were lower than those in EC solution, but similarly increased after initial ischemia. At 24 h, the concentrations produced by the left and right kidneys were as follows: ET 0.66±0.1 pg/ml vs 0.48±0.1 pg/ml (P0.14); A-II 10.36±3.7 pg/ml vs 2.14±0.7 pg/ml (P0.006); TxB₂ 178±53 pg/ml vs 52±23.1 pg/ml (P0.001); and PGI₂ 448.3±49 pg/ml vs 323±44.3 pg/ml (P0.01), respectively. After 48 h, the range of concentrations of each substance was similar to that obtained after 24 h. In further studies, the concentrations of ET and A-II were measured in solution previously used to preserve human kidneys (n=7). The mean concentration of ET and A-II in these samples was 3.82±1.14 pg/ml and 21.3±9.2 pg/ml, respectively, whereas in control media both substances were below the limits of detection. These results demonstrate that vasoconstrictive substances can be measured in the preservation media after a kidney has been stored cold and that higher concentrations are found when the organ has been subjected to prior normothermic ischemia. The measurement of these vasoactive substances before transplantation may reveal that the kidney has been subjected to previous ischemic events. Moreover, these vasoactive substances could be involved in the early recovery of renal function after kidney transplantation.     

o-cresol: a good indicator of exposure to low levels of toluene

This study evaluates the suitability of using urinary excretion of o-cresol (o-CR) as a biological marker of occupational exposure to various concentrations of toluene (TOL). Thirty-eight individuals from three plants involved in the manufacture of paints or inks agreed to participate in the environmental and biological monitoring evaluations, which lasted one to two days. In all, 62 measurements of environmental TOL and urinary o-CR and hippuric acid (HA) levels were made. The eight-hour TOL exposure (time-weighted average [TWA]) ranged from 0 to 111 ppm, depending on plant and job title. TOL exposure was well correlated to post-shift urinary o-CR (r = 0.89) and HA (r = 0.67) levels. At low exposure levels (below 50 ppm), however, o-CR shows a stronger correlation (r = 0.71) than HA (r = 0.24). Based on our results, occupational exposure to 50 ppm of TOL would result in end-of-shift urinary o-CR concentration of 0.72 mumol/mmol creatinine (0.69 mg/L, assuming a urinary creatinine concentration of 1 g/L). This value is of the same order of magnitude as the level proposed by the American Conference of Governmental Industrial Hygienists (ACGIH) in 1998 for exposure to 50 ppm of TOL, namely 0.5 mg/L. Our results suggest that the level of urinary o-CR is a more sensitive index of exposure to low concentrations of TOL than is the urinary concentration of HA.     

Stability of Natural Self-Reactive Antibody Repertoires During Aging

We have used a quantitative immunoblotting technique to analyze the repertoires of self-reactive antibodies in serum samples obtained from the same five healthy adults over a 25-year interval. The average age of the donors was 43 years at the time of the first serum sample and 69 years at the time of the second serum sample. The antibody repertoires of IgM and IgG were found to be strikingly similar among individuals in both early and late samples. Densitometric profiles of self-reactivity of serum IgM and of purified serum IgG remained unchanged over the 25-year interval. The total reactivity of serum IgG decreased significantly over the 25-year period. The observed stability of the natural self-reactive IgM and IgG antibody repertoires with aging supports the view that autoreactive B cells in the normal immune system are positively selected for reactivity with a limited set of immuno-dominant self-antigens throughout life.     

Modulation of 5-HT1A receptor signalling by point-mutation of cysteine351 in the rat Galpha(o) protein.

The activity state of G proteins is involved in the ligands' maximal responses that can be produced by activating the 5-HT1A receptor (Pauwels et al., 1997). The present study investigated the ligand responses at the recombinant h 5-HT1A receptor (RC: 2.1.5HT.01A) as mediated by the Galpha(o) protein. Therefore, a fusion protein was constructed between the 5-HT1A receptor and a pertussis toxin resistant rat Galpha(o)Cys351Gly mutant protein to define its pharmacological properties at a receptor: Galpha(o) protein density ratio of 1. Pertussis toxin treatment (100 ng/ml) affected neither the expression of the 5-HT1A receptor fusion protein as measured by [3H] MPPF (3.0+/-0.7 pmol/mg protein) nor the 5-HT-mediated [35S]GTPgammaS binding response (146+/-34 fmol/mg protein) in Cos-7 cells. 8-OH-DPAT (Emax: 55+/-7%) and buspirone (Emax: 22+/-4%) yielded partial agonist activity as compared to 5-HT, whereas WAY 100635 acted as a competitive antagonist (pK(B): 9.75+/-0.17). The magnitude of the 8-OH-DPAT response (Emax, %) was highly dependent on the nature of the amino acid 351 in the C-terminus of the Galpha(o) protein: Ile351 (93+/-4) > Cys351 (79+/-3) > Gly351 (55+/-7). The Emax values (%) of buspirone displayed the following gradient: 69+/-5 approximately/= 62+/-8 > 22+/-4. For comparison, maximal responses of 8-OH-DPAT and buspirone were enhanced versus 5-HT upon co-expression of the 5-HT1A receptor with the respective Galpha(o) proteins, probably due to an altered receptor: Galpha(o) protein density ratio. In conclusion, residue 351 of the rat Galpha(o) protein is involved in determining the magnitude of 5-HT1A receptor activation that ligands can produce at these receptors. Moreover, the fusion protein approach allows quantitative comparisons of the intrinsic activities of ligands between one single receptor subtype with different Galpha protein subtypes.     

Rectal Mucosa Damage in Rabbits After Subchronical Application of Suppository Bases

The effect of suppository bases on rabbit rectal mucosa was investigated using six triglyceride bases, polyethylene glycol, and a triglyceride base combined with monoglycerides or fatty acids and methyl esters of those acids. Rectal irritation was evaluated and scored according to defined pathological features. Pure triglycerides and a triglyceride to which a nonionic surfactant was added caused severe mucosal damage with ulceration and inflammation. Hyperemia was characteristic for irritation by polyethylene glycol suppositories. Mucosal damage by a pure triglyceride combined with monoglycerides or fatty acids and methyl esters of those acids was similar but statistically less pronounced than with all other bases.