Focal hyperexpression of hemeoxygenase-1 protein and messenger RNA in rat brain caused by cellular stress following subarachnoid injections of lysed blood

Induction of the hemeoxygenase-1 (ho-1) stress gene is of importance for rapid heme metabolism and protection against oxidative injury in vitro and in vivo. Although ho-1 expression is observed in glia following exposure to whole blood and oxyhemoglobin, expression is mild, and other stress genes are not induced simultaneously in this setting. Hemeoxygenase-1 can be induced by several other physiological stresses in addition to heme. In the brain, ho-1 induction has been observed in the penumbra following focal cerebral ischemia. Because lysed blood is a spasmogen, the authors studied focal hyperexpression of the ho-1 gene after injection of lysed blood, whole blood, or saline into the cisterna magna of adult rats. Immunocytochemical analysis of HO-1 was performed at 1, 2, 3, and 4 days after the injections. Because the 70-kD inducible heat shock protein (HSP70) is induced by cellular stress, alternate sections were immunostained for HSP70 to assess whether focal hyperexpression was a stress phenomenon. An oligonucleotide probe was also used for in situ hybridization to demonstrate that ho-1 messenger (m)RNA was present. Focal HO-1 immunostained areas were observed after lysed blood injection only and were located mainly in the basal cortex and cerebellar hemisphere, although focal hyperexpression was also found in many other regions. The intensity of staining and the number of regions were maximum at 1 day. Double-labeled immunofluorescence revealed that many HO-1-immunoreactive cells were microglia. The HSP70 immunostaining of adjacent sections from the same animals demonstrated focal regions of immunoreactivity whose topography corresponded exactly with the topography of the HO-1-immunostained areas. Conventional histology in regions of HO-1 hyperexpression was often normal. In situ hybridization using the same oligonucleotide demonstrated that ho-1 mRNA was induced in focal areas of forebrain and in large regions of cerebellum within 6 hours of injection. These results demonstrate that focal hyperexpression of the ho-1 stress gene occurs after lysed blood injection and appears to be an indicator of cellular stress and injury in regions in which infarction does not occur. These results also suggest that cellular injury that occurs after injection of lysed blood may go undetected using conventional histology. Although direct heme metabolism was not investigated, our results indicate that rapid metabolism of heme, both intracellular and extracellular, may prove to be beneficial after subarachnoid hemorrhage.     

Protective effects of various preservation solutions on cultured endothelial cells

Vascular endothelium represents the first target in organ preservation and plays an important role in reperfusion injury. Bovine aortic endothelial cells were cultivated and the most commonly used preservation solutions, such as University of Wisconsin HTK (Brettschneider's histidine-tryptophane-ketoglutarate), and Euro-Collins solutions were tested on the endothelial monolayer. In addition, one group of cultivated cells was preserved with cold saline solution, and endothelial monolayers grown in culture medium were used as controls. The quality of preservation was assessed after 24, 48, and 72 hours of cold storage. Reperfusion was simulated and its effects were observed by reincubation in culture medium at 37 degrees C for 6 hours. The total number of cells, cell viability (determined using trypan blue exclusion), and morphologic alterations were determined. Prostacyclin release was evaluated as a biochemical marker. University of Wisconsin solution maintains more than 99% cell viability after rewarming after both 24 and 48 hours of cold storage. After 72 hours, 86.7% of cells were still viable. Preservation with HTK and Euro-Collins solution allowed cell survival for only 24 hours (96.7%, HTK; 49.9%, Euro-Collins), with no viable cells seen after 48 hours. The cold saline-preserved sample showed 57.8% viable cells after 24 hours and 29.7% after 48 hours. No viable cells were detectable after 72 hours. Light microscopy revealed several patterns of both structural damage and intracellular change (nucleus and cytoplasm) in the endothelial monolayer after preservation with HTK, Euro-Collins solution, and cold saline solution. No morphologic alterations were seen in the University of Wisconsin solution group for as long as 72 hours.(ABSTRACT TRUNCATED AT 250 WORDS)     

Laboratory evaluation of the XR-Bond Dentin/Enamel Bonding System

The shear bond strengths of the XR-Bonding System used in conjunction with Herculite composite, to the dentine of forty extracted human permanent first and second molars were determined after the test specimens were stored in physiological saline at 37 degrees C for 48 hours, one week, two weeks and four weeks, respectively. A shear load was applied to the base of the bonded composite cylinders with a knife-edged rod at a crosshead speed of 0.5 mm/minute. The shear bond strengths were expressed in megapascals (MPa). The quantitative microleakage of Class V preparations in dentine (cementum) in forty-eight extracted human maxillary permanent canines restored with the same dentinal bonding system and after storage in physiological saline at 37 degrees C for the same time intervals as for the shear bond strength tests, was determined. On the final day of each time interval the teeth were thermocycled X 500 in a 2 per cent methylene blue solution between 8 degrees C and 50 degrees C with a dwell time of 15 seconds. Microleakage was determined by a spectrophotometric dye-recovery method and expressed in microgram dye/restoration. There was a significant trend for the shear bond strengths to increase with duration of storage (p = 0.01) but the quantitative microleakage was not significantly different (p = 0.75).     

Hematopoietic effects and clinical uses of granulocyte-macrophage colony-stimulating factor and PIXY321

We tested the influence of in vivo volume resuscitation on intrinsic contractile properties of left ventricular (LV) preparations of endotoxemic guinea pigs. Escherichia coli endotoxin (LPS)-injected animals were divided into nonresuscitated and resuscitated groups. Volume resuscitation improved cardiac output and stroke volume, increased arterial pH and body temperature, and decreased mortality. In isovolumetric LV preparations isolated 4 h after LPS injection, LV systolic pressures (in mmHg) preparations isolated 4 h after LPS injection, LV systolic pressures (in mmHg) of LPS with (42 +/- 3) and without (42 +/- 2) fluid resuscitation were consistently less than control values (70 +/- 3). LV end-diastolic pressure-volume (compliance) decreased in LPS-nonresuscitated hearts, while LV compliance of LPS-resuscitated hearts was similar to control. Thus, intravascular volume expansion selectively improved LV diastolic compliance of LPS hearts without affecting LV systolic function. These findings suggest that LV systolic and diastolic dysfunctions associated with endotoxemia and Gram-negative sepsis may involve separate pathogenic mechanisms.     

Investigation of ductile damage development in ferritic steel subject to uniaxial deformation

The object of this investigation is the influence of uniaxial deformation on both the formation of voids and ductile damage in ferritic steel. Specimens are prepared by means of a method which, to a large extent, is free of manipulation and permits the crystal's interior to be observed. These specimens were investigated using a scanning electron microscope (SEM). Anisotropic void formation and growth behaviour were exhibited which is correlated with the material texture using an EBSD investigation. Observing the crystalline structure by means of transmission electron microscopy (TEM) enables the effects of the pore formation and growth to be examined in more detail.     

Experimental toxoplasmosis in broiler chicks

To evaluate chicken toxoplasmosis both as an economic and a public health subject, 84 broiler chicks of a commercial strain, 30 days old, were distributed into seven groups of 12 birds (three replications of four chicks) experimentally infected with three developing T. gondii stages of the P strain as follows: tachyzoites, intravenous (two groups: 5.0 x 10(5) and 5.0 x 10(6)), cysts, per os (two groups: 1.0 x 10(2) and 1.0 x 10(3)) and oocysts, per os (three groups: 5.0 x 10(2), 5.0 x 10(3) and 5.0 x 10(4)). Twelve chicks received only a placebo (control group). During the next 30 days the following parameters were estimated: productivity (weight gain and feed conversion), clinical signs, including rectal temperature and parasitemia (bioassay). No clinical signs suggesting toxoplasmosis were seen and no statistical differences on productivity standards were found in comparison between inoculated and control chicks. However, fowls inoculated with tachyzoites and oocysts occasionally showed hyperthermia. Some haematological changes were detected in fowls inoculated with T. gondii. Anatomo-histopathological changes were not observed. From 14 parasitemias detected, 35.7% appeared on the 5th day after inoculation and 57.1% of them resulted from oocysts inoculation. After 30-35 days all birds were slaughtered: fragments from 12 organs or tissues from each of them were subjected to artificial peptic digestion and after that injected into T. gondii antibody-free mice (IIFR). T. gondii was detected in brain (12), pancreas (five), spleen (five), retina (five), kidney (two), heart (four), proventriculus (three), liver (two), intestine (two), lung (one), and skeletal muscle (one). Similar to observations with parasitemia, from 42 T. gondii isolations, 59.5% came from chicks which had received oocysts. It can thus be inferred that the developing form, expelled by cats, is the most important for T. gondii chicken infection and that brain is the most infected organ in birds. Attention must be paid to the potential importance of chicken meat in public health, since T. gondii was isolated from skeletal and heart muscles.     

Cognitive, adaptive, and behavioral characteristics of Williams syndrome

The difference of morphological injury between rabbit aorta and pulmonary artery was compared after the animal was exposed to the altitude 5 km (PO2 = 10.8 kPa) for 24 h. Hypoxia caused subendothelial edema, increased vacuoles and injured mitochondria and endoplasmic reticulums in both kinds of endothelial cells. The impairment of pulmonary artery was obviously more severe than aorta and its smooth muscle cells were also affected. Forthermore, the exposure increased mitochondria in pulmonary artery endothelial cells. Bubbled with a mixture air of 95% N2-5% CO2 (PO2 = 4 kPa) led to an increase of pulmonary in tension, while hypoxia to the same extent induced aorta relaxation. These results indicate that hypoxia produces the differential effects on these two kinds of vessels, providing a possible explanation for the production of hypoxic pulmonary hypertension.     

High-dose busulfan, melphalan, thiotepa and peripheral blood stem cell infusion for the treatment of metastatic breast cancer

The purpose of this study was to determine the outcome of patients with metastatic breast cancer treated with high-dose busulfan (Bu), melphalan (Mel) and thiotepa (TT) followed by peripheral blood stem cell (PBSC) infusion. Fifty-one patients with chemotherapy refractory (n = 32) or responsive (n = 19) metastatic breast cancer received Bu (12 mg/kg), Mel (100 mg/m2) and TT (500 mg/m2) followed by PBSC collected after chemotherapy and growth factor (n = 43) or growth factor alone (n = 8). The 100 day treatment-related mortality was 8% including one death from cytomegalovirus pneumonia, one from aspiration pneumonia and two from regimen-related toxicity (RRT). Seven of 28 refractory (25%) and 5/7 (71%) responsive patients with evaluable disease achieved a complete response of all measurable disease or all soft tissue disease with at least improvement in bone lesions (PR*). Fifteen of 51 patients (29%) are alive and progression-free a median of 423 days (range 353-934) after treatment, 5/32 (16%) with refractory disease and 10/19 (53%) with responsive disease. The probabilities of progression-free survival (PFS) at 1.5 years for the patients with refractory (n = 32) and responsive (n = 19) disease were 0.24 and 0.53, respectively. These preliminary data suggest that high-dose Bu/Mel/TT has significant activity in patients with advanced breast cancer and may be superior to some previously published regimens.