The effect of etophylline clofibrate on HDL subfractions

The effect of etophylline clofibrate on lipids and apolipoproteins of the high density lipoprotein (HDL) subfractions HDL2 and HDL3 as well as on very low density (VLDL) and low density lipoproteins (LDL) and the post heparin lipolytic activities (PHLA) of lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL) has been studied in 14 patients with type II hyperlipoproteinemia (HLP). The study was preceded by a 4-week washout phase, followed by a 6-week placebo period. During the next 12 weeks, the patients received 750 mg etophylline clofibrate per day. Then the drug was again replaced by placebo for another 6 weeks. During the study the patients were on a low fat diet poor in cholesterol with a P/S ratio over 1.0. HDL cholesterol and apoproteins increased significantly during treatment. In the first verum phase this effect was related to the rise in HDL2 components with minor changes in HDL3 concentrations, whereas in the second verum period a distinct increase of the HDL3 components could be detected. This development was accompanied by a significant increase of the LPL activities during the first 6 weeks of treatment, followed by a decrease to initially measured values after 12 weeks. The drug lowered plasma- and LDL-cholesterol levels by 19% and 22%, and plasma and VLDL triglycerides by 22% and 25%, respectively. VLDL-C apoproteins (C-I, C-II, C-III) declined by 31% with a percentage increase of apo C-II compared with apo C-I and apo C-III.     

Obesity, But Not High-Fat Diet, Promotes Murine Pancreatic Cancer Growth

Background

Obesity accelerates pancreatic cancer growth; the mechanisms underlying this association are poorly understood. This study evaluated the hypothesis that obesity, rather than high-fat diet, is responsible for accelerated pancreatic cancer growth.

Methods

Male C57BL/6J mice were studied after 19?weeks of high-fat (60?% fat; n?=?20) or low-fat (10?% fat; n?=?10) diet and 5?weeks of Pan02 murine pancreatic cancer growth (flank).

Results

By two-way ANOVA, diet did not (p?=?0.58), but body weight, significantly influenced tumor weight (p?=?0.01). Tumor weight correlated positively with body weight (R ²?=?0.562; p?<?0.001). Tumors in overweight mice were twice as large as those growing in lean mice (1.2?±?0.2?g vs. 0.6?±?.01?g, p?<?0.01), had significantly fewer apoptotic cells than those in lean mice (0.8?±?0.4 vs 2.4?±?0.5; p?<?0.05), and greater adipocyte volume (3.7 vs. 2.2?%, p?<?0.05). Apoptosis (R ²?=?0.472; p?=?0.008) and serum adiponectin correlated negatively with tumor weight (R?=?0.45; p?<?0.05).

Conclusions

These data suggest that body weight, and not high-fat diet, is responsible for accelerated murine pancreatic cancer growth observed in this model of diet-induced obesity. Decreased tumor apoptosis appears to play an important mechanistic role in this process. The concept that decreased apoptosis is potentiated by hypoadiponectinemia (seen in obesity) deserves further investigation.     

Fetal tissue engineering from amniotic fluid

BACKGROUND: We have recently shown, in an animal model, that amniotic fluid can be a source of cells for fetal tissue engineering. This study was aimed at determining whether fetal tissue constructs could also be engineered from cells normally found in human amniotic fluid. STUDY DESIGN: Cells obtained from the amniotic fluid of pregnant women at 15 to 19 weeks of gestation (n=6) were cultured in Dulbecco's Modified Eagle's medium (Sigma Chemical, St Louis, MO) containing 20% fetal bovine serum and 5 ng/mL basic fibroblast growth factor in a 95% humidified, 5% CO(2) chamber at 37 degrees C. A subpopulation of morphologically distinct cells was then mechanically isolated from the rest and selectively expanded. The lineage of this subpopulation of amniocytes was determined by immunofluorescent staining with antibodies against standard intermediate filaments and surface antigens. Cell proliferation rates were determined by oxidation assay. After cell expansion, colonies of amniocytes were statically and dynamically seeded onto both unwoven, 1-mm-thick polyglycolic acid polymer scaffold and acellular human dermis for 72 hours. The resulting constructs were analyzed by scanning electron microscopy. RESULTS: Amniocytes stained positively for smooth muscle actin, vimentin, cytokeratin 18, and fibroblast surface protein, and negatively for desmin, cluster of differentiation 31, and von Willebrand's factor (Dako, Carpenteria, CA). These findings are consistent with a mesenchymal, fibroblast-myofibroblast cell lineage. Mesenchymal amniocytes could be rapidly expanded in culture, based on results of the proliferation assay. Scanning electron microscopy of amniocyte constructs revealed dense, confluent layers of cells surrounding the polymer matrices and firm cell adhesion to both PGA and Alloderm (Lifecell Corp, Branchburg, NJ) scaffolds. No evidence of cell death was observed. CONCLUSIONS: Subpopulations of fetal mesenchymal cells can be consistently isolated from human amniotic fluid and rapidly expanded in vitro. Human mesenchymal amniocytes attach firmly to both polyglycolic acid polymer and acellular human dermis. The amniotic fluid can be a valuable and practical cell source for fetal tissue engineering.     

Involvement of cyclic nucleotides in renal artery smooth muscle relaxation

The elevation of vascular smooth muscle tone in the renal arteries during kidney transplantation and nephron-sparing surgery plays a major role in postsurgical organ dysfunction. Therefore, a better understanding of the intracellular mechanisms of contraction and relaxation is of fundamental interest to improve urological treatment. The present study was designed to investigate the complex intracellular system of cyclic nucleotides involved in the regulation of smooth muscle relaxation by using swine renal artery rings in the Schuler organ bath. Phenylephrine (PE) induced dose-dependent and fully reversible isometric contractions with a threshold concentration of 10 nM and an EC(50) of 804 nM. The receptor was identified as alpha(1A)-subtype by the selective antagonist WB4101. Increasing the intracellular concentration of cyclic 3':5'-adenosine monophosphate (cAMP) by dibutyryl-cAMP (5 mM) and forskolin (5 micro M) resulted in a decreased contractiltity of 48.0% and 76.3%, respectively. Elevation of the cytosolic content of cyclic 3':5'-guanosine monophosphate (cGMP) using dibutyryl-cGMP (1 mM), sodium nitroprusside (100 micro M) and SIN-1 (100 micro M) decreased the average PE-induced contraction by 16.4%, 41.9% and 62.4%, respectively. The unselective phosphodiesterase inhibitors theophylline (1 mM), papaverine (100 micro M) and IBMX (5 mM) reduced the PE-induced contraction by 37.3%, 93.1% and 95.5%, respectively. Furthermore, selective inhibition of phosphodiesterases by milrinone (PDE(3)-selective) resulted in a decreased contractility by 1.3% (50 micro M), 29.5% (100 micro M) and 93.5% (5 mM), and using rolipram (PDE(4) selective), the PE-induced contraction was inhibited by 57.9% (50 micro M) and 81.9% (100 micro M). The results suggest the involvement of cAMP and cGMP in the relaxation of renal artery smooth muscle cells. Moreover, phosphodiesterases, especially PDE(3) and PDE(4), seem to play a critical role in the regulation of renal artery smooth muscle tone.     

CDKN2A germline mutations in familial pancreatic cancer

OBJECTIVE: To evaluate the prevalence of mutations in the CDKN2A gene encoding p16 and p14 in familial pancreatic cancer (FPC). SUMMARY BACKGROUND DATA: The genetic basis of FPC is still widely unknown. Recently, it has been shown that germline mutations in the p16 tumor suppressor gene can predispose to pancreatic cancer. The presence of p14 germline mutations has yet not been determined in this setting. METHODS: Eighteen families with at least two first-degree relatives with histologically confirmed pancreatic cancer and five families with at least one patient with pancreatic cancer and another first-degree relative with malignant melanoma of the German National Case Collection for Familial Pancreatic Cancer were analyzed for CDKN2A germline mutations including p16 and p14 by direct DNA sequencing. All participating family members were genetically counseled and evaluated by a three-generation pedigree. RESULTS: None of 18 FPC families without malignant melanoma revealed p16 mutations, compared to 2 of 5 families with pancreatic cancer and melanoma. Truncating p16 germline mutations Q50X and E119X were identified in the affected patients of pancreatic cancer plus melanoma families. None of the 23 families revealed p14 germline mutations. CONCLUSIONS: CDKN2A germline mutations are rare in FPC families. However, these data provide further evidence for a pancreatic cancer-melanoma syndrome associated with CDKN2A germline mutations affecting p16. Thus, all members of families with combined occurrence of pancreatic cancer and melanoma should be counseled and offered screening for p16 mutations to identify high-risk family members who should be enrolled in a clinical screening program.     

Long-term outcome of conservative surgery for kidney cancer: survival,blood pressure,and renal function

PURPOSE: Nephron-sparing surgery (NSS) for renal cell carcinoma (RCC) remains controversial for elective indications (low stage RCC in the presence of a normal contralateral kidney). In this single center study survival rate and, as novel aspects, the frequency of postoperative arterial hypertension and renal function parameters were investigated to evaluate safety and efficacy of NSS. PATIENTS AND METHODS: The complete data of 248 patients operated nephron-sparing for RCC between 1975 and 1995 were evaluated. One hundred and seventy-five patients were treated for elective indication (95% with tumor stage T1 or T2), 73 patients for mandatory indication (bilateral tumors, solitary kidney, renal insufficiency). The mean follow-up was 75 months (maximum 23 years). RESULTS: Mean tumor-size was lower under elective (3.8 cm) than under mandatory (4.7 cm) indication. Overall tumor-specific survival after 5 years for both indications was 88%. Comparing preoperative vs. follow-up values, arterial blood pressure and serum-creatinine values remained unchanged for both indications. The incidence of postoperative proteinuria (19% imperative, 11% elective indication) was strongly related to hypertension. CONCLUSIONS: NSS for RCC under elective indication achieves patient survival comparable to the results of radical nephrectomy. The presented data do not indicate significant longterm complications such as arterial hypertension, proteinuria or deterioration of renal function as a result of glomerulosclerosis or hyperfiltration. This gives further argument for the concept of NSS in RCC as an alternative to radical nephrectomy in the presence of a healthy contralateral kidney.     

Regional response of cerebral blood volume to graded hypoxic hypoxia in rat brain

Background. The response of cerebral blood flow to hypoxic hypoxiais usually effected by dilation of cerebral arterioles. However,the resulting changes in cerebral blood volume (CBV) have receivedlittle attention. We have determined, using susceptibility contrastmagnetic resonance imaging (MRI), changes in regional CBV inducedby graded hypoxic hypoxia. Methods. Six anaesthetized rats were subjected to incrementalreduction in the fraction of inspired oxygen: 0.35, 0.25, 0.15,and 0.12. At each episode, CBV was determined in five regionsof each hemisphere after injection of a contrast agent: superficialand deep neocortex, striatum, corpus callosum and cerebellum.A control group (n=6 rats) was studied with the same protocolwithout contrast agent, to determine blood oxygenation leveldependent (BOLD) contribution to the MRI changes. Results. Each brain region exhibited a significant graded increasein CBV during the two hypoxic episodes: 10–27% of controlvalues at 70% Sa_O2, and 26–38% at 55% Sa_O2. There wasno difference between regions in their response to hypoxia.The mean CBV of all regions increased from 3.6 (SD 0.6) to 4.1(0.6) ml (100 g)^–1 and to 4.7 (0.7) ml (100 g)^–1during the two hypoxic episodes, respectively (SchefféF-test; P<0.01). Over this range, CBV was inversely proportionalto Sa_O2 (r²=0.80). In the absence of the contrast agent, changesdue to the BOLD effect were negligible. Conclusions. These findings imply that hypoxic hypoxia significantlyraises CBV in different brain areas, in proportion to the severityof the insult. These results support the notion that the vasodilatoryeffect of hypoxia is deleterious in patients with reduced intracranialcompliance. Br J Anaesth 2002; 89: 287–93     

Changes in C-reactive protein predict insulin sensitivity in severely obese individuals after weight loss surgery

The production of inflammatory mediators by abdominal adipose tissue may link obesity and insulin resistance. We determined the influence of systemic levels of interleukin-6 and C-reactive protein on insulin sensitivity after weight loss via Roux-en-Y gastric bypass surgery. Severely obese individuals (n 5 15) were evaluated at baseline and at 6 months after surgery. Insulin sensitivity was determined by frequently sampled intravenous glucose tolerance testing at the same time points. Visceral and subcutaneous adipose tissue volumes were quantified by computed tomography. Interleukin-6 and C-reactive protein were measured by enzyme-linked immunoassay in plasma and in adipose tissue biopsies. Correlation analysis was used to determine associations between insulin sensitivity and other outcome variables. Significance was set at P < 0.05. Plasma interleukin-6 concentrations were significantly correlated to the IL-6 content of subcutaneous adipose tissue (r = 0.71). At 6 months postsurgery, subcutaneous and visceral adipose tissue volumes were significantly reduced (34.7% and 44.1%, respectively) and insulin sensitivity had improved by 160.9%. Significant longitudinal correlations were found between insulin sensitivity and plasma C-reactive protein (r = 20.61), but not plasma interleukin-6 at 6 months. These findings offer insights that link obesity and insulin resistance via the activity of inflammatory mediators. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18, 2005 (oral presentation). Supported by National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Diseases 1R03 DK067167-01A1 (N.G.), the Emory University Research Committee Grant (N.G.), and the National Institutes of Health/National Center for Research Resources General Clinical Research Center Grant M01 RR00039 (N.G., E.L.).     

Current TNM classification of renal cell carcinoma evaluated: revising stage T3a

PURPOSE:: Recent studies of rare cases of pT3a renal cell carcinoma extending directly into the adrenal gland showed worse survival than in other pT3a cases and recategorization as stage pT4 was suggested. We assessed the prognostic validity of a stage pT3a diagnosis based on perirenal fat infiltration. MATERIALS AND METHODS:: The records of 1,794 patients with renal cell carcinoma who underwent surgical resection between 1975 and 2000 at our institution were analyzed retrospectively. Focusing on pT3a tumors, as defined by perirenal fat infiltration, numerous clinical and histopathological parameters were investigated by univariate and multivariate statistical methods with cancer specific survival as the primary end point. RESULTS:: We identified 237 of 1,794 patients with perirenal fat infiltration, classified as having pT3a disease. In patients with pT3a tumors tumor size was a significant parameter predicting survival. The most significant cutoff value for tumor size in pT3a disease was 7 cm. Patients with distant metastasis had a worse prognosis independent of T classification. Therefore, to assess the prognostic value of the current T classification in regard to T3a tumors we excluded patients with tumor stage cM+ for further subgroup analysis. Survival comparison of pT1 pNall, cM0 (744 of 1,794 cases) and pT3a pNall, cM0 7 cm or less (100 of 237) as well as pT2 pNall, cM0 (265 of 1,794) and pT3a pNall, cM0 greater than 7 cm (93 of 237) yielded similar results. After splitting pT3a into a modified T1/T2 classification a significant difference in 5-year survival analysis for a modified T1/T2 stage was found (pT1 plus pT3a less than 7 cm 90% vs pT2 plus pT3a greater than 7 cm 73%, p <0.001). Subsequently multivariate analysis in all 1,794 patients showed that modified T stage was an independent significant predictor of cancer specific survival. CONCLUSIONS:: We suggest revising the current pT3a classification based on perirenal fat infiltration but rendering a modified pT1/pT2 classification, which resolves pT3a cases without the loss of prognostic validity. Perirenal fat infiltration should not be used to assign T category. Tumors directly infiltrating the adrenal gland should be reclassified as T4.     

Use of interventions for reducing mother-to-child transmission of HIV in Australia

OBJECTIVE: To describe the extent and outcome of use of interventions for reducing the risk of HIV transmission from mother to child in Australia. DESIGN: National surveillance for perinatal exposure to HIV. PARTICIPANTS AND SETTING: Notified cases of HIV infection in women in Australia and their perinatally exposed children, 1982-1999. OUTCOME MEASURES: Trends over time in use of interventions (antiretroviral therapy in pregnancy, elective caesarean delivery and avoidance of breastfeeding) and perinatally acquired HIV infection. RESULTS: By 31 March 2000, 204 children were reported as having been born in 1982-1999 to 162 women whose HIV infection had been diagnosed by 31 December 1999. The child's HIV infection status was established for 182 (89.2%); the mother's HIV infection was diagnosed antenatally in 91 of these cases (50%). Among women diagnosed antenatally, use of elective caesarean delivery and antiretroviral therapy in pregnancy increased significantly, from 3% and 14% by women whose children were born in 1982-1993, to 21% (P=0.01) and 88% (P<0.001), respectively, by women whose children were born in 1994-1999. Most women (95%) diagnosed antenatally avoided breastfeeding their children. The percentage of infected children born to women diagnosed antenatally declined from 26% among children born in 1982-1993 to 19% among those born in 1994-1999. The percentage of infected children was significantly lower among those whose mothers used antiretroviral therapy in pregnancy (11% versus 36%; P=0.03). CONCLUSION: Antiretroviral use in pregnancy, elective caesarean delivery and avoidance of breastfeeding have been effective interventions for reducing the risk of mother-to-child HIV transmission in Australia. While the rate of perinatal HIV transmission has declined, it remains high in comparison with rates reported from other industrialised countries.