Pneumonia complicating abdominal sepsis: an experimental model of hematogenous contamination of the lung.

Pulmonary infection complicating intra-abdominal sepsis is a major clinical problem. An experimental model for intra-abdominal sepsis was created with implantation of gelatin capsules, containing 3 x 10(8) cfu E. coli strain no. 2554, in the peritoneal cavity of 20 rats (10 animals received and 10 did not receive antibiotic therapy with ceftriaxone) in order to verify the role of the primary site of infection in the pathogenesis of pneumonia. Ten rats were sacrificed to determine the relative pulmonary weight and 10 were submitted to simple laparotomy and insertion of a germ-free capsule (sham-operated group). In this group of animals there was only one death (10%). All the rats that received antibiotic therapy survived until sacrifice while all the rats that did not receive ceftriaxone died, 7 within the 2nd and 3 on the 6th postoperative day. Pneumonia and peritonitis developed only in the animals that did not receive ceftriaxone. Bacteriological findings of material obtained from peritoneal and pleural cavities revealed the same strain of E. coli used for the experiment, suggesting that bacteria involved in the pleuro-pulmonary infections may originate in the primary site of infection and that antibiotic therapy started at the moment of contamination, can prevent this major complication.     

How are health professionals earning their living in Malawi?

Background  

The migration of health professionals from southern Africa to developed nations is negatively affecting the delivery of health care services in the source countries. Oftentimes however, it is the reasons for the out-migration that have been described in the literature. The work and domestic situations of those health professionals continuing to serve in their posts have not been adequately studied.     

Plasminogen activator system modulates invasivecapacity and proliferation in prostatic tumor cells

The malignant phenotype of prostatic tumor cells correlates with the expression of both uPA and itscell-membrane receptor (uPAR); however, there is little information concerning the role of cell-bound uPAin matrix degradation and invasion. Our results suggest that cell-associated uPA plays a key role in regulat-ingthe amount of plasmin present at the surface of prostatic carcinoma (PRCA) cells and show that differ-entialproduction of uPA corresponds with the capacity to bind and activate plasminogen. In addition, weprovide direct evidence that both uPA secretion and the presence of uPA-uPAR complexes characterize theinvasive phenotype of PRCA cells and suggest the existence of several pathways by which tumor cells acquireplasmin activity. LNCaP cells (which do not produce uPA but express uPAR) may activate plasmin throughexogenous uPA. In vivo, the source of uPA may be infiltrating macrophages and/or fibroblasts as observedin several other systems. PAI-1 accumulation in the conditioned medium (CM) limits plasmin action to thepericellular microenvironment. Our results indicate that MMP-9 and MMP-2 are also activated by plasmingenerated by cell-bound but not by soluble, extracellular uPA. Plasmin activation and triggering of the pro-teolyticcascade involved in Matrigel invasion is blocked by antibodies against uPA (especially by anti- A-chainof uPA which interacts with uPAR) and by PA inhibitors such as p-aminobenzamidine which mayregulate levels of cell-bound uPA. uPA may also regulate growth in PRCA cells. Indeed, antibodies againstuPA A-chain (and also p-aminobenzamidine treatment) interfere with the ATF domain and inhibit cell growthin uPA-producing PC3 and DU145 prostate cancer cell lines, whereas exogenous uPA (HMW-uPA with ATF)induces growth of LNCaP prostate tumor cell line. These data support the hypothesis that in prostatic can-cerpatients at risk of progression, uPA/plasmin blockade may be of therapeutic value by blocking both growthof the primary tumor and dissemination of metastatic cells. ©Kluwer Academic Publishers     

Some endocrine and morphological aspects of the acute toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

Hormonal status was evaluated in TCDD-treated rats and in pair-fed and ad libitum-fed controls in order to separate hormonal changes resulting from the toxic insult of TCDD from those arising from progressive feed deprivation as it occurs in pair-fed controls. TCDD-treated rats received either a usually non-lethal (25 micrograms/kg) or a usually lethal (125 micrograms/kg) dose of TCDD whereas pair-fed and ad libitum-fed controls were given vehicle alone. Animals were terminated at predetermined time intervals and several hormones measured in serum or plasma. In addition, the morphology of the thyroid, pancreas, and pituitary was also examined. In both dosage groups, TCDD-treatment had the following effects: decreased TT4, FT4, insulin, and glucagon; mixed effects upon TT3, FT3, TSH, and GH. Pair-feeding to the non-lethal dose of TCDD had no effect on any of the hormones measured. Pair-feeding to the lethal dose of TCDD had the the following effects: slightly decreased TT4, FT4, TT3, TSH, and insulin; no effect on FT3 and glucagon. It is concluded that the endocrine status of TCDD-treated rats was different from that of pair-fed rats suggesting that some hormonal changes represent responses to an insult other than that due to starvation stress alone. A differential response between TCDD-treated and pair-fed rats was also observable morphologically in the corresponding endocrine glands indicating the importance of this additional control for morphologic observations in instances when reduced feed intake and body weight loss are prominent features of toxicity.     

Scintigraphic assessment of "effort" axillary-subclavian vein thrombosis.

"Effort" axillary-subclavian vein thrombosis (Paget-Schroetter syndrome) is an uncommon deep venous thrombosis due to repetitive activity of the upper limb. Clinical suspicion is usually confirmed by contrast venography. This report describes a case where the diagnosis was made by radionuclide venography (Tc-99m DTPA). The examination was carried out in the acute phase and clearly demonstrated the presence and the site of the obstruction as well as the collateral vessels. Despite a complete clinical recovery, obtained by medical therapy, further examinations performed in the follow-up period showed persistence of the thrombotic obstruction and a rich development of collateral vessels. In the authors' opinion, radionuclide venography is worth considering as a first-choice procedure when an axillary-subclavian vein thrombosis is suspected, and contrast venography should be performed only when surgical treatment is indicated.     

Hypoxia and glucose metabolism in malignant tumors: evaluation by [18F]fluoromisonidazole and [18F]fluorodeoxyglucose positron emission tomography imaging.

PURPOSE: The aim of this study is to compare glucose metabolism and hypoxia in four different tumor types using positron emission tomography (PET). (18)F-labeled fluorodeoxyglucose (FDG) evaluates energy metabolism, whereas the uptake of (18)F-labeled fluoromisonidazole (FMISO) is proportional to tissue hypoxia. Although acute hypoxia results in accelerated glycolysis, cellular metabolism is slowed in chronic hypoxia, prompting us to look for discordance between FMISO and FDG uptake. EXPERIMENTAL DESIGN: Forty-nine patients (26 with head and neck cancer, 11 with soft tissue sarcoma, 7 with breast cancer, and 5 with glioblastoma multiforme) who had both FMISO and FDG PET scans as part of research protocols through February 2003 were included in this study. The maximum standardized uptake value was used to depict FDG uptake, and hypoxic volume and maximum tissue:blood ratio were used to quantify hypoxia. Pixel-by-pixel correlation of radiotracer uptake was performed on coregistered images for each corresponding tumor plane. RESULTS: Hypoxia was detected in all four patient groups. The mean correlation coefficients between FMISO and FDG uptake were 0.62 for head and neck cancer, 0.47 for breast cancer, 0.38 for glioblastoma multiforme, and 0.32 for soft tissue sarcoma. The correlation between the overall tumor maximum standardized uptake value for FDG and hypoxic volume was small (Spearman r = 0.24), with highly significant differences among the different tumor types (P < 0.005). CONCLUSIONS: Hypoxia is a general factor affecting glucose metabolism; however, some hypoxic tumors can have modest glucose metabolism, whereas some highly metabolic tumors are not hypoxic, showing discordance in tracer uptake that can be tumor type specific.     

Gender-specific brachial artery blood pressure-independent relationship between pulse wave velocity and left ventricular mass index in a group of African ancestry

AIM: As it is uncertain whether arterial stiffness is related to left ventricular mass and left ventricle mean wall thickness independent of blood pressure measured at the brachial artery, we aimed to ascertain this effect in never-treated participants with a high prevalence of risk factors for large artery dysfunction. METHODS: The conventional and ambulatory blood pressure-independent relations between indices of large artery function and either left ventricular mass or mean wall thickness were determined in 309 never-treated randomly recruited South Africans of African ancestry with prevalent risk factors for large artery changes [24% were hypertensive, 63% were overweight/obese, and 17% had diabetes mellitus or abnormal blood glucose control (glycosylated hemoglobin A1c > 6.1%)]. Large artery function was assessed from applanation tonometry performed at the carotid, radial and femoral arteries and central augmentation index and aortic pulse wave velocity (carotid femoral pulse wave velocity) derived from these measures. Left ventricular mass indexed for height (left ventricular mass index) and mean wall thickness were determined using echocardiography. RESULTS: Pulse wave velocity was associated with left ventricular mass index (r = 0.67, P < 0.0001) and mean wall thickness (r = 0.61, P < 0.0001) in women, but not in men (r = 0.04-0.08) (P < 0.0001 for the interaction between pulse wave velocity and gender). On multivariate analysis with appropriate adjustments including either conventional systolic blood pressure, pulse pressure or mean arterial pressure, pulse wave velocity was independently associated with left ventricular mass index (partial r = 0.25, P < 0.005 after adjustments for systolic blood pressure) and with mean wall thickness (partial r = 0.17, P < 0.05 after adjustments for systolic blood pressure) in women, but not in men. With the inclusion of 24-h ambulatory rather than conventional systolic blood pressure, pulse pressure or mean arterial pressure in the regression equation, pulse wave velocity was similarly independently associated with left ventricular mass index (partial r = 0.39, P < 0.001 after adjustments for 24-h systolic blood pressure) and mean wall thickness (partial r = 0.33, P < 0.003 after adjustments for 24-h systolic blood pressure) in women, but not in men. Central augmentation index was not independently associated with left ventricular mass index or mean wall thickness. In women, the contribution of pulse wave velocity to left ventricular mass index or mean wall thickness independent of systolic blood pressure (standardized beta-coefficient for left ventricular mass index=0.37 +/- 0.13, P < 0.005) was equivalent to the contribution of systolic blood pressure (standardized beta-coefficient for left ventricular mass index = 0.38 +/- 0.13, P < 0.005). Moreover, after adjusting for clinic or ambulatory systolic blood pressure and other confounders, in women every one standard deviation increase in pulse wave velocity (2.1 m/s) translated into a 4.3 or 6.2 g/m increase in left ventricular mass index, respectively. CONCLUSION: Arterial stiffness is associated with left ventricular mass index and left ventricle wall thickness independent of conventional or ambulatory blood pressure and additional confounders in a never-treated population sample of women, but not men, of African ancestry with prevalent risk factors for large artery dysfunction.     

超声心动图评估梗阻性与非梗阻性完全型肺静脉异位引流

目的 探讨完全型肺静脉异位（TAPVC）的超声诊断特点及梗阻性与非梗阻性TAPVC在手术前后的异同。方法 选取TAPVC患儿112例,分为梗阻组34例及非梗阻组78例。分别于术前、术后一个月及六个月进行超声心动图检查,评价心内结构、功能及肺静脉引流情况。应用M型超声测量左、右心室舒张末期内径（LVD, RVD）,脉冲多普勒测量肺静脉流速,连续多普勒测量三尖瓣反流峰值压差（PTR）。分析并比较同一患儿术前术后以及两组患儿间心室内径及PTR的变化,以及两组间死亡率及术后肺静脉梗阻（PVO）发生率。 结果 超声心动图对TAPVC的诊断率为100%,准确率为89%。梗阻组较非梗阻组手术月龄及体重低,差异具有统计学意义（P值均<0.001）。术后一个月两组患儿LVD及LVD/RVD均明显增大,RVD及PTR明显减小,差异均有统计学意义（P值均<0.01）。术后一月及六个月两组患儿PTR及LVD/RVD均没有统计学上的差异 （P值均>0.05）。术后死亡率梗阻组较高,差异具有统计学意义（11.8% vs 0%,P<0.01）。术后PVO发生率在两组间没有统计学差异（P>0.05）。结论 超声心动图是TAPVC早期诊断的有效方法,且可对分型、肺动脉压力及梗阻性TAPVC的梗阻部位及程度进行较为准确的评估。梗阻性患儿更需要早期诊断及时治疗,两组患儿在外科矫治后均可获得较为满意的预后,梗阻性患儿死亡率相对较高,而术后PVO发生率没有明显差异。