Inhibitory effects of low-level laser therapy on skin-flap survival in a rat model

BACKGROUND:Although several studies have demonstrated the effects of low-level laser therapy (LLLT) on skin flap viability, the role of higher doses has been poorly investigated.OBJECTIVE:To investigate the inhibitory effect of the LLLT (λ=670 nm) on the viability of random skin flaps in a rat model using an irradiation energy of 2.79 J at each point.METHODS:Sixteen Wistar rats were randomly assigned into two groups: sham laser irradiation (n=8); and active laser irradiation (n=8). Animals in the active laser irradiation group were irradiated with a 670 nm diode laser with an energy of 2.79 J/point, a power output 30 mW, a beam area of 0.028 cm², an energy density of 100 J/cm², an irradiance of 1.07 W/cm² for 93 s/point. Irradiation was performed in 12 points in the cranial skin flap portion. The total energy irradiated on the tissue was 33.48 J. The necrotic area was evaluated on postoperative day 7.RESULTS:The sham laser irradiation group presented a mean (± SD) necrotic area of 47.96±3.81%, whereas the active laser irradiation group presented 62.24±7.28%. There was a significant difference in skin-flap necrosis areas between groups (P=0.0002).CONCLUSION:LLLT (λ=670 nm) increased the necrotic area of random skin flaps in rats when irradiated with an energy of 2.79 J (100 J/cm²).     

Influence of shaking on peritoneal transfer in rats

To determine the role played by stagnant peritoneal fluid layers in the diffusion of solutes between peritoneal cavity and blood, we measured peritoneal transfer of urea, creatinine, [14C]-L-glucose and protein in anesthetized rats shaken at varying rates on an orbital platform shaker. The diffusion transfer rates of the low molecular weight solutes increased dramatically with shaking, with near maximal values obtained at a shaking rate of 250 RPM. The permeability area product (PA) for each of the low molecular weight solutes increased about fourfold with rapid shaking while the PA of protein increased by only about 50%. It seems likely while the PA of protein increased by only about 50%. It seems likely that shaking increased PA primarily via reduction of the thickness of stagnant peritoneal fluid layers, although increases in surface area or changes in tissue permeability cannot be excluded with certainty. We conclude that stagnant fluid layers probably are the rate limiting step in diffusive peritoneal transfer of low molecular weight solutes in stationary rats.     

Timely transfer of peritoneal dialysis patients to hemodialysis improves survival rates

AIMS: The two main renal replacement therapies (RRT)--hemodialysis (HD) and peritoneal dialysis (PD)--have been considered to be antagonistic in most published studies on the clinical outcomes of dialysis patients. Recently, it has been suggested that the complementary use of both modalities as an integrated care (IC) strategy might improve the survival rate of end-stage renal disease patients. The aim of this study was to estimate the final clinical outcome of PD patients when they transfer to HD because of complications related to PD. MATERIALS AND METHODS: We retrospectively analyzed data from the following patients that started RRT during the last 10 years: 33 PD patients (IC group; age 55 +/- 15 years, mean +/- SD) who transferred to HD, 134 PD patients (PD group, age 64 +/- 11 years) who remained in PD, and 132 HD patients (HD group, age 48 +/- 16 years) who started and continued in HD. The main reasons for the transfer to HD were relapsed peritonitis and loss of ultrafiltration, while various comorbid risk factors were adjusted by Cox hazards regression model (age, presence of diabetes or/and cardiovascular disease, serum hemoglobin and albumin levels, as well as the modality per se). RESULTS: 3- and 5-year survival rates for the IC, PD and HD groups were 97% and 81%, 54% and 28%, and 92% and 83%, respectively. The 5-year survival rate was significantly higher in IC patients than in PD patients (p < 0.00001) but, was not different from that in HD patients. CONCLUSIONS: Our results show that the IC of dialysis patients undergoing RRT improves the survival of patients on PD if they are transferred to HD upon the appearance of PD related complications.     

甲状腺组织培养条件对移植存活的影响

本文采用两大气压氧与低ＰＨ值相结合培养大鼠甲状腺组织４８小时，将甲状腺组织块移植入受体的肾包膜下，从Ｔ３、Ｔ４均值、均匀体重增长及移植组织观察四个方面评价移植物存活及排斥反应情况。     

Effect of hyperthermic preconditioning on the survival of ischemia-reperfused skin flaps: a new skin-flap model in the mouse

To investigate whether hyperthermic preconditioning can actually protect skin flaps against ischemia/reperfusion injury, the authors first developed a new skin-flap model in 15 mice, a dorsal bipedicle island skin-flap model. Then, another 75 mice were separated into five groups. Mice in Groups 1 to 4 received the same hyperthermic preconditioning, but had different recovery times of 6 hr, 24 hr, 48 hr, and 72 hr, respectively. Mice in Group 5 served as control. Island skin flaps were elevated in all groups, and then were subjected to 8 hr of ischemia and subsequent reperfusion. Flap survival was statistically significantly higher than in controls in animals in Groups 1 and 3, with recovery times of 6 hr and 48 hr, respectively. Mice in Groups 2 and 4 had recovery times of 24 hr and 72 hr, respectively. Hyperthermic preconditioning could thus protect skin flaps against ischemia/reperfusion injury, and there were two optimal periods for such a protective effect.     

术前TACE对可切除大肝癌术后无瘤生存率及生存率的影响

目的 分析术前经导管肝动脉化疗栓塞(TACE)对可切除大肝癌术后无瘤生存率及总生存率的影响,探讨可切除大肝癌术前TACE意义. 方法 108例大肝癌病例分成术前TACE组(n=52)与一期手术组(n=56),进行随访,并根据有无肉眼子灶、癌栓分组对照作生存分析. 结果 二期手术组与一期手术组无瘤生存率及总生存率差异无统计学意义. 结论可切除大肝癌术前TACE并未能提高无瘤生存率及总生存率,应首选手术治疗.     

Influence of hepatic artery ligation on survival: An experimental study in rats

Interruption of the arterial blood supply to the liver has been used clinically for more than 15 years in patients with nonresectable liver tumors. The induced effect of hepatic artery occlusion on blood flow and metabolism has been studied extensively, whereas survival time has hardly been examined. Evidence of prolongation of survival after hepatic artery ligation, although not properly statistically analyzed, has been found in previous series of experimental animals, but the effect has not been established clinically. In this experimental study of rats with adenocarcinoma in the liver, a statistically significant prolongation of survival time was observed for the animals subjected to hepatic artery ligation when compared with untreated control animals. A statistically significant increase in body weight developed in all ligated animals during the experimental period, whereas the untreated control animals showed a statistically significant decrease in body weight.     

Ten-year survival rates in breast cancer using combination chemotherapy.

The outcome in 254 patients with all stages of breast cancer treated by combination chemotherapy is presented. All the patients were treated 10 or more years ago. The 10-year survival rate for Stages I and II combined is 60 per cent, in Stage III 19 per cent and in Stage IV 3 per cent. The combined rate in Stages I and II differed markedly according to hormonal status. In premenopausal patients the rate was 84 per cent compared with 42 per cent in postmenopausal patients.     

Outpatient biopsy of breast cancer. Influence on survival.

From 1948 to 1975, at the Istituto Nazionale Tumori of Milan, 209 patients underwent extended radical mastectomy (ERM) for breast cancer classified as T1 NO-1 MO. In 57 patients (27.3%), the ERM was preceded by an excisional biopsy performed in the outpatient clinic (Group A), of which 75% were performed within 30 days of admission and 25% after 30 days (average, 25 days; range 5-99). The remaining 152 patients (Group B) underwent an extemporaneous frozen biopsy. There was no difference in the distribution of the histologic types in the two groups. The axillary lymph nodes (N) and the internal mammary chain (MI) were free of neoplastic invasion (N-, MI-) in 156 patients (74.6%), 44 in Group A (77.2%) and 112 in Group B (73.7%). Actuarial 10-year survival of the patients was 79.9% in Group A and 77.7% in Group B (p = NS). It was 90% in N- MI- patients of Group A and 81.9% in those of Group B (p = NS). Instead, for N+ patients, actuarial survival at 10 years was 50% in Group A and 67% in Group B (p = NS), and for MI+ patients it was 50% and 49.8%, respectively. These present data do not support the hypothesis that a delay between biopsy and radical surgery of breast cancer is an important prognostic factor.     

Inhibition of apoptosis prevents liver failure and improves survival rates after extensive hepatectomy in rats

An important cause of postoperative hepatic failure is an inappropriate extensive hepatectomy (HPx). Recent data indicate that apoptosis plays a crucial role in the post-HPx remnant liver dysfunction. We advanced the hypothesis that inhibition of apoptosis prevents liver failure after HPx. It was shown that Cyclosporin A (Cys) protects against apoptosis. To investigate whether post-HPx liver failure is an apoptosis dependent phenomenon, we pretreated Sprague-Dawley rats with Cys A (10 mg/kg) immediately before 85% HPx. A group was submitted to HPx only, and control animals were sham-operated. Twenty-four hours later, half of the animals of each group were sacrificed and liver was fixed for optical observation. The remaining rats were followed-up for survival rates. Liver dysfunction at sacrifice was significantly lower in Cys treated animals as demonstrated by serum levels of total and direct bilirubin, AST and ALT (p < 0.05). In parallel, the Cys A group disclosed a lower number of apoptotic cells, and less severe liver injuries (p = 0.000). HPx rat survival was marginally ameliorated by Cys pretreatment. Our data support the hypothesis that apoptosis is a relevant mechanism of post-HPx hepatic failure.     

Influence of previous immunization on skin graft survival.

The results of skin grafts transplanted in immunized and nonimmunized recipients was analysed. Specific sensitization for HLA-A or B determinants shortens graft survival if the recipients were immunized by s.c. injections of leukocytes. When the recipients had been pregnant, no such influence of specific HLA-A or B sensitization could be demonstrated. The variance in mean survival times of grafts exchanged between mixed lymphocyte culture (MLC)-positive donor-recipient combinations was significantly smaller than the variance in mean survival time (MST) of grafts exchanged between MLC-negative combinations. This difference could be the result of the influence of allograft immune-activating determinants of different strength in the MLC-negative donor-recipient combinations. Also the variance in MST of grafts in immunized recipients was significantly larger than the variance in MST of grafts in nonimmunized recipients. Apart from the obvious effect of HLA-A and B sensitization, other less well documented factors must have influenced graft survival. We did not find evidence for a graft enhancing effect of B cell-specific antibodies.     

Diabetic patients survival rates in dialysis

Since the beginning of the eighties, the prevalence and incidence of diabetes have been increasing in dialysis units. In France, type 2 diabetes accounts for approximately 90% of diabetic hemodialysis patients. Among the etiologies of renal failure, diabetes is characterized by increased hospitalization rates and reduced quality of life, transplantation rates and survival. In dialysis patients, diabetes mellitus enhances the main factors leading to an increase in cardiovascular and non-cardiovascular deaths: inflammation, dyslipidemia, hypertension, increased energy expenditure, oxidative stress and plasma assymetrical dimethylarginine. The prevention of these complications includes the control of blood glucose, plasma lipids, hypertension, and anemia. The role of antioxidant therapies remains to be evaluated.