Analysis of CD40 expression in breast cancer and its relation to clinicopathological characteristics

Breast cancer is currently the most common cancer in women worldwide. For this reason, new biomarkers for better predicting response to treatment are needed. CD40, described as expressed in haematological and epithelial tumors, is linked to apoptosis and offers promise as a new predictive/ prognostic marker. We evaluated CD40 expression in formalin-fixed, paraffin-embedded samples from 181 breast carcinomas using immunohistochemical staining with CD40 antibody. Samples were divided according to hormone (oestrogen receptor /ER/, progesterone receptor /PR/) and her-2/neu status into groups: 1.Luminal A (ER+PR+her-2/neu-), 2. Luminal B (ER+PR+her-2/neu+), 3.Triple-negative (ER-PR-her-2/neu-) and 4. Her-2/neu (ER-PR-her-2/neu+). The results of CD40 staining were correlated with clinicopathological data. CD40 was found to be expressed in membrane, cytoplasm and nucleus. Normal ducts expressed cytoplasmic CD40 in 30% of cases, in breast tumor ducts in 53% of cases. CD40 was evaluated as an independent marker and significant positive correlation was found with Bcl-2 (p =0.002), early stage (p =0.016) and preoperative chemotherapy (p =0.043). There was higher overall survival for patients with cytoplasmic CD40 expression (0.05). Differences in expression of cytoplasmic CD40 between groups with different hormonal and her-2/neu status were statistically highly significant (p=0.00003). In groups with different hormonal status, a positive statistical correlation was found for the luminal A group with relapse (p=0.024) and stage (p=0.006). No correlation was found with age, disease onset, family history of cancer/ breast cancer, patient history, hormonal replacement therapy, menopausal status at onset of disease, adjuvant chemotherapeutic treatment or disease free survival. Nuclear expression of CD40 was found to be unrelated to any clinicopathological data. However, there was higher ratio of positive cases in cancer cases (83%) than in normal tissue (30%). In conclusion, cytoplasmic expression of CD40 is related to factors connected to better prognosis and suggest that CD40 may have potential as a new prognostic factor in breast cancer.

Expression of adipokines and estrogen receptors in adipose tissue and placenta of patients with gestational diabetes mellitus

The purpose of this study was to assess the expression profile of genes with potential role in the development of insulin resistance (adipokines, cytokines/chemokines, estrogen receptors) in subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT) and placenta of pregnant women with gestational diabetes mellitus (GDM) and age-matched women with physiological pregnancy at the time of Caesarean section. qRT-PCR was used for expression analysis of the studied genes. Leptin gene expression in VAT of GDM group was significantly higher relative to control group. Gene expressions of interleukin-6 and interleukin-8 were significantly increased, whereas the expressions of genes for estrogen receptors alpha and beta were significantly reduced in SAT of GDM group relative to controls, respectively. We found no significant differences in the expression of any genes of interest (LEP, RETN, ADIPOR1, ADIPOR2, TNF-alpha, CD68, IL-6, IL-8, ER alpha, ER beta) in placentas of women with GDM relative to controls. We conclude that increased expression of leptin in visceral adipose depot together with increased expressions of proinflammatory cytokines and reduced expressions of estrogen receptors in subcutaneous fat may play a role in the etiopathogenesis of GDM.

Analysis of VEGF, Flt-1, Flk-1, nestin and MMP-9 in relation to astrocytoma pathogenesis and progression

Astrocytomas, particularly high grade astrocytoma, are brain tumors with potent angiogenic activity. Our immnunohistochemical study assessed vascular endothelial growth factor (VEGF), VEGF receptors (Flk-1, and Flt-1), the intermediate filamental protein nestin which plays a role in central nervous system development, and MMP-9, which belongs the family of matrix metalloproteinases implicated in tumor invasion and angiogenesis regulation. We investigated the expression of VEGF, its receptors, nestin and MMP-9 in astrocytomas and their correlation with tumor grade. We used paraffin-embedded samples from 66 patients, 29 with low grade (WHO-grade II) and 37 with high grade (WHO-grade III and IV) astrocytomas. Antibodies against VEGF, Flk-1, Flt1, nestin, CD34 and MMP-9 were used, followed by standard indirect immunohistochemical methods. Expression of Flt-1 and Flk-1 showed no significant differences between low and high grade tumor groups. Expression of VEGF and MMP-9 was increased in the high grade group (p equal to or less than 0.026 and 0.024). Nestin expression in tumor astrocytes and endothelial cells increased in high grade group (p same 0.007 and 0.003). Higher expression of VEGF in high grade astrocytomas may subsequently lead to activation of survival, angiogenesis and migration. Expression of nestin and MMP-9 also suggest their likely role in astrocytoma vascular development and proliferation.

Could changes in the regulation of the PI3K/PKB/Akt signaling pathway and cell cycle be involved in astrocytic tumor pathogenesis and progression?

The most frequent alterations found in astrocytomas are two major groups of signaling proteins: the cell cycle and the growth factor-regulated signaling pathways. The aim of our study was to detect changes in expression of the following proteins: the tumor suppressors PTEN, p53, and p21Waf1/Cip1, glial fibrillary acidic protein (GFAP, as a marker of astroglial differentiation), the phosphorylated form of protein kinase B/Akt (PKB/Akt), which is downstream to the epidermal growth factor receptor (EGFR), and MDM2, which degrades p53. Paraffin-embedded astrocytoma tissue samples from 89 patients were divided into low grade (grade I-II; 42 samples) and high grade astrocytomas (grade III-IV; 47 samples). Mouse monoclonal antibodies against GFAP, PTEN, PKB/Akt phosphorylated on serine 473, EGFR, p53, p21Waf1/Cip1 and MDM2 were used, followed by standard indirect immunohistochemical method. EGFR protein was detected in 29 % of low grade and in 60 % of high grade astrocytomas. The expression of phosphorylated PKB/Akt was found in roughly the same proportions: in 86% of low grade and in 79% of high grade astrocytomas. PTEN was not found in most of astrocytomas, 64% of low grade and 74% of high grade tumors showed no PTEN staining. Overexpression of the mutated form of p53 or loss of p53 expression, however, was found in about 63% in both groups of astrocytomas with no differences between them. GFAP expression was decreased in tumor astrocytes compared to normal astrocytes and this decreased with grading. GFAP positive tumor cells were detected in only 50% of low grade, and 32% of high grade astrocytomas. The level of MDM2 expression was similar in both grades. Loss of p21Waf1/Cip1 expression was shown in 20% of low and in 45% of high grade tumors. In the subgroup of high grade tumors with wild type p53, 86% showed p21Waf1/Cip1 expression, whereas in the subgroup of high grade tumors with altered p53, only 35% displayed p21Waf1/Cip1. We conclude that EGFR expression increases with astrocytoma grading. EGFR activation may subsequently lead to stimulation of the PKB/Akt survival pathway. PTEN defects may also participate in aggressive tumor behaviour through activation of the PKB/Akt pathway. The alteration of p53 supports the finding that the cell cycle regulation is also disrupted during development of astrocytomas. The changes in PTEN and p53 expression, and activation of PKB/Akt are events in the early stages of astrocytomagenesis. EGFR is one of the factors, which drives the progression of astrocytomas from low to high grade stage.

Dynamic study of the distribution of microcirculatory blood flow in multiple splanchnic organs in septic shock

OBJECTIVES

To study dynamic distribution of microcirculatory blood flow in multiple splanchnic organs during septic shock; to test the hypothesis that changes in microcirculatory blood flow in splanchnic organs correlate with changes in regional flow during septic shock.

DESIGN

A prospective, controlled, animal study.

SETTING

Animal laboratory in a university medical center.

SUBJECTS

Nine anesthetized and mechanically ventilated domestic pigs.

INTERVENTIONS

Systemic flow (cardiac output) was measured with thermodilution and regional (superior mesenteric artery) flow with transit time flowmetry. Local blood flow (microcirculatory flow) was continuously measured in splanchnic organs (gastric, jejunal, and colon mucosa, liver, and pancreas) and the kidney with multichannel laser Doppler flowmetry. Septic shock was induced with fecal peritonitis. After 240 mins of sepsis, intravenous fluids were administered to alter hypodynamic shock to hyperdynamic septic shock.

MEASUREMENTS AND MAIN RESULTS

In this severe septic shock model, systemic and regional flows decreased by approximately 50% during the first 240 mins. Similar reductions were recorded in microcirculatory flow in the mucosa of the stomach (-41%; p < .001) and colon (-47%; p < .001). In the jejunal mucosa, on the other hand, flow remained virtually unchanged. Microcirculatory flow was also significantly decreased in the liver (-49%; p < .001), pancreas (-56%; p < .001), and kidney (-44%; p < .001). Administration of intravenous fluids at 240 mins was followed by three-fold increases in systemic and regional flows (approximately 70% above baseline). In the jejunal mucosa, flow also increased significantly above baseline (42%; p < .001), whereas in the stomach and the colon, it barely reached baseline. Kidney blood flow increased to baseline, whereas pancreas and liver flows remained 26% (p < .05) and 34% (p < .001), respectively, below baseline.

CONCLUSION

Changes in microcirculatory blood flow in the splanchnic organs are heterogeneous, both in early hypodynamic and in hyperdynamic septic shock, and cannot be predicted from changes in systemic or regional flows. Microcirculatory blood flow in the jejunal mucosa remains constant during early septic shock, whereas pancreatic blood flow decreases significantly more than regional flow.

Continuous measurements of microcirculatory blood flow in gastrointestinal organs during acute haemorrhage

Hypoperfusion of splanchnic organs is an important contributor to the development of multiple organ failure after major surgery and trauma. During general anaesthesia and surgery we compared changes in systemic haemodynamics and regional blood flow with changes in the distribution of microcirculatory flow (MBF) in multiple splanchnic organs in pigs exposed to acute haemorrhage. Seven pigs (25 kg) were bled to a mean arterial pressure of 40 mm Hg; 180 min later the shed blood was retransfused. MBF was measured in the intestinal mucosa (stomach, jejunum, colon), pancreas, liver and kidney using a six-channel laser Doppler flowmeter. Cardiac output was measured by thermodilution and superior mesenteric artery flow by ultrasonic flowmetry. During haemorrhage, MBF in the gastric and colon mucosa and flow in the liver and kidney decreased to a similar extent to regional and systemic flows (30-50%). In contrast, MBF in the jejunal mucosa remained virtually unchanged and flow in the pancreas decreased significantly more than systemic and regional flows (60%, P < 0.05). We conclude that: (1) changes in the distribution of MBF in the gastrointestinal tract during acute haemorrhage are heterogeneous and cannot be predicted from changes in systemic or regional haemodynamics; (2) MBF in the jejunal mucosa did not decrease during haemorrhage, indicating that autoregulation of blood flow in the mucosa remained intact during shock; and (3) MBF in the pancreas decreased significantly more than systemic and regional flows during shock, suggesting that the pancreas is particularly vulnerable to haemorrhage.

Effects of sodium nitroprusside and phenylephrine on blood flow in free musculocutaneous flaps during general anesthesia

BACKGROUND

Hypoperfusion and necrosis in free flaps used to correct tissue defects remain important clinical problems. The authors studied the effects of two vasoactive drugs, sodium nitroprusside and phenylephrine, which are used frequently in anesthetic practice, on total blood flow and microcirculatory flow in free musculocutaneous flaps during general anesthesia.

METHODS

In a porcine model (n = 9) in which clinical conditions for anesthesia and microvascular surgery were simulated, latissimus dorsi free flaps were transferred to the lower extremity. Total blood flow in the flaps was measured using ultrasound flowmetry and microcirculatory flow was measured using laser Doppler flowmetry. The effects of sodium nitroprusside and phenylephrine were studied during local infusion through the feeding artery of the flap and during systemic administration.

RESULTS

Systemic sodium nitroprusside caused a 30% decrease in mean arterial pressure, but cardiac output did not change. The total flow in the flap decreased by 40% (P < 0.01), and microcirculatory flow decreased by 23% in the skin (P < 0.01) and by 30% in the muscle (P < 0.01) of the flap. Sodium nitroprusside infused locally into the flap artery increased the total flap flow by 20% (P < 0.01). Systemic phenylephrine caused a 30% increase in mean arterial pressure, whereas heart rate, cardiac output, and flap blood flow did not change. Local phenylephrine caused a 30% decrease (P < 0.01) in the total flap flow.

CONCLUSIONS

Systemic phenylephrine in a dose increasing the systemic vascular resistance and arterial pressure by 30% appears to have no adverse effects on blood flow in free musculocutaneous flaps. Sodium nitroprusside, however, in a dose causing a 30% decrease in systemic vascular resistance and arterial pressure, causes a severe reduction in free flap blood flow despite maintaining cardiac output.

Effects of extradural anesthesia on microcirculatory blood flow in free latissimus dorsi musculocutaneous flaps in pigs

Free musculocutaneous flaps are used frequently in plastic surgery to reconstruct soft-tissue defects after radical cancer surgery and trauma. Despite improved surgical techniques, some of these flaps fail due to insufficient blood supply. Extradural anesthesia causes both sensory (pain relief) and sympathetic (vasodilatation) block that may be advantageous in free-flap surgery. This hypothesis, however, has not yet been studied. An experimental model in pigs was developed in which clinical conditions for anesthesia and microvascular surgery on the lower extremity were simulated as closely as possible. The effects of extradural anesthesia as well as phenylephrine infusion, combined with general anesthesia, on central hemodynamics and on microcirculatory blood flow in skin and muscle of the latissimus dorsi free flap were studied. After surgery, seven animals received extradural anesthesia during stable normovolemic conditions and another seven during mild hypovolemia (10 percent blood loss). The extradural block was objectively evaluated using the temporal summation test. Thirty minutes after induction of extradural anesthesia, the animals received an intravenous infusion of phenylephrine 1 microgram/kg per minute over a period of 15 minutes. Multichannel laser-Doppler flowmetry was used to measure microcirculatory blood flow in skin and muscle of the free flap as well as in control skin and muscle on the same extremity simultaneously. In normovolemic animals, extradural block caused a 10 percent decrease in mean arterial pressure and cardiac output and an approximately 20 percent decrease in microcirculatory blood flow in both the skin and muscle of the flap (all changes were nonsignificant). In slightly hypovolemic animals, however, extradural anesthesia caused a significant decrease in cardiac output (31 percent, p < 0.01), mean arterial pressure (24 percent, p < 0.01), and in mean blood flow in the flap muscle (22 percent, p < 0.05) and skin (20 percent, p < 0.05). During phenylephrine infusion, mean arterial pressure increased significantly (p < 0.05) in both hypovolemic and normovolemic animals, while cardiac output and microcirculatory blood flow in the flap remained almost unchanged. Extradural anesthesia does not improve microcirculatory blood flow in free musculocutaneous flaps in pigs. It causes a significant decrease in cardiac output, mean arterial pressure, and microcirculatory blood flow in slightly hypovolemic animals. During phenylephrine infusion, the microcirculatory blood flow in free flaps slightly improves due to the increase in mean arterial pressure. We suggest that extradural anesthesia for microvascular surgery should be used with great caution until human data are available.