Effect of 1,25(OH)2D3 on BALB/c mice infected with Leishmania mexicana.

The most active metabolite of vitamin D, 1,25(OH)2D3 is a steroid hormone implicated in a wide range of cell functions such as differentiation, proliferation and apoptosis. Leishmania mexicana causes two kinds of cutaneous leishmaniasis: localized or diffuse. In this work we explored the effect of treatment of 1,25(OH)2D3 on a susceptible leishmaniasis mice model. A significant reduction in the lesion size was found in animals treated with 1,25(OH)2D3. Well preserved tissue and presence of large numbers of eosinophils and fibroblasts was found in the group treated with 1,25(OH)2D3. By contrast, destroyed epidermis was observed with large amount of neutrophils and epithelioid macrophages, on infected groups without 1,25(OH)2D3 treatment. The production of pro-inflammatory cytokines in mice infected and treated with 1,25(OH)2D3 was lower than the animals infected without 1,25(OH)2D3 treatment. Interestingly, there were no differences in the number of parasites in both groups. Finally, the amount of collagen was higher in animals with treatment compare with animals without 1,25(OH)2D3 treatment. In summary, mice treated with 1,25 (OH) 2D3 reflect a healing process without elimination of L. mexicana.

Pulmonary Embolism Complicated by Acute Limb Ischemia Managed by Surgical Pulmonary Embolectomy.

Acute pulmonary embolism (PE) is a manifestation of venous thromboembolic disease with potential serious and life-threatening complications. Management options for acute PE have drastically improved over the last 15 years with the introduction of multidisciplinary pulmonary embolism response teams throughout the world. We present the case of an 18-year-old woman diagnosed with acute PE complicated by near-complete occlusion of her left common femoral artery from a paradoxical embolus in the setting of patent foramen ovale (PFO), managed with surgical pulmonary embolectomy and surgical PFO repair.

Entamoeba histolytica: expression and localization of Gal/GalNAc lectin in virulent and non-virulent variants from HM1:IMSS strain.

We have purified Gal/GalNAc lectin from Entamoeba histolytica by electroelution. The purified protein was used to immunize rabbits and obtain polyclonal IgG's anti-lectin. These antibodies were used as tools to analyze the expression and localization of the amoebic lectin in both virulent (vEh) and non-virulent (nvEh) variants of axenically cultured HM1:IMSS strain. vEh is able to induce liver abscesses in hamsters, whereas nvEh has lost this ability. In vitro, amoebic trophozoites from both variants equally express this protein as shown by densitometric analysis of the corresponding band in Western blots from lysates. In both types of trophozoites, the pattern of distribution of the lectin was mainly on the surface. We have also compared by immunohistochemistry the presence and distribution of lectin in the in vivo liver lesions produced in hamsters. In order to prolong the survival of nvEh to analyze both variants in an in vivo model, hamsters inoculated with nvEh were treated with methyl prednisolone. Our results suggest that the Gal/GalNAc lectin is equally expressed in both nvEh and vEh.

Human and porcine neurocysticercosis: differences in the distribution and developmental stages of cysticerci.

OBJECTIVE: To describe and compare the clinical impacts of neurocysticercosis (NC) caused by Taenia solium in humans and pigs. METHODS: Comparative study of the brains of 16 asymptomatic pigs and 35 human NC cases (15 asymptomatic and 20 symptomatic). RESULTS: In humans, cysticerci were more frequently located in the ventricles and subarachnoid space at the base of the brain (11.8%vs. 1.6%; P = 0.001 and 25.9%vs. 0%; P < 0.0001, respectively) while in pigs, cysticerci were more frequently found in the parenchyma (44.4%vs. 7.6%; P < 0.0001). In human brains, 75.9% of the cysticerci were calcified, while in pigs all cysticerci were in the vesicular stage. CONCLUSION: The duration of infection and the host-parasite relationship (such as immune reactivity and brain haemodynamics) differ between humans and pigs. This may account for the different distribution and stage of the cysticerci among humans and pigs.

Vitamin D and Postoperative Vasopressor Use in Cardiopulmonary Bypass.

The use of cardiopulmonary bypass (CPB) in cardiac surgery often leads to a systemic inflammatory response. Up to 25% of patients undergoing CPB for cardiac surgery are reported to develop vasoplegic syndrome in the acute postoperative period, in which the patients are refractory to vasopressors. The purpose of this study is to assess vitamin D deficiency as a risk factor for vasoplegia after using CPB. We performed a retrospective review of 1322 patients undergoing adult cardiac surgery requiring CPB. Forty-six patients with previously recorded 25-hydroxy vitamin D (25(OH)D) levels within 6 months of surgery met the conditions of this study. The mean level of 25(OH)D was 32.7 ng/mL (standard deviation [SD] = 15.1). The mean age of patients was 67 (SD = 10.1) years old, most were male (63%) and white (78%). Average CPB time was 140 ± 44 minutes. Postoperative vasopressor use was compared to individual preoperative 25(OH)D levels. As a secondary end point, postoperative vasopressor use and vasoplegia were analyzed between 3 groups: Vitamin D deficient defined as 25(OH)D ≤20 ng/mL (n = 7), vitamin D insufficient defined as 25(OH)D between 20 and 29 ng/mL (n = 15), and vitamin D sufficient defined as 25(OH)D ≥30 ng/mL (n = 24). There was no correlation between vitamin D levels and postoperative vasopressor use. The mean doses of postoperative vasopressor use were 0.088 µg/kg/min (standard error of the mean [SEM] = 0.032), 0.085 µg/kg/min (SEM = 0.037), and 0.072 µg/kg/min (SEM = 0.024) of norepinephrine equivalents for the vitamin D deficient, insufficient, and sufficient groups, respectively. Incidence of vasoplegia for each group was the following: 0.143 for vitamin D deficient, 0.067 for vitamin D insufficient, and 0.125 for vitamin D sufficient. In this pilot study, there does not appear to be a relationship between vitamin D and vasopressor use following cardiac surgery utilizing CPB; however, there appears to be a trend toward an increased vasopressor usage in patients with decreased vitamin D levels. A larger sample size and a prospective analysis are warranted to further assess the significance of the relationship between vasoplegia and vitamin D deficiency. With further investigation, vitamin D has the potential to become a low-cost, low-risk therapeutic for improving outcomes in CPB surgery.

Real-time monitoring of cardiac metabolism using biosensors shows myocardial protection during ischemia-reperfusion injury with glucose-insulin-potassium administration.

BACKGROUND: Systemic infusion of glucose-insulin-potassium (GIK) is thought to confer myocardial protection during ischemia-reperfusion injury. Our laboratory has experience with real-time monitoring of glucose and pH levels using needle-mounted biosensors. We tested the hypothesis that GIK enhances myocardial metabolism as displayed by real-time myocardial metabolic monitoring. METHODS: A total of 40 kg male swine were randomized to receive GIK (n = 7) or lactated Ringer's (n = 7) solution intravenously at 1.5 mL/kg/hour. Ischemia was induced in the left anterior distribution (LAD) by 20 minutes LAD occlusion, followed by 20 minutes reperfusion. Hearts were instrumented anteriorly and posteriorly with continuously recording myocardial pH and glucose biosensors. Biopsies from the LAD distribution were taken at baseline, maximum ischemia, and after reperfusion to assess cardiac adenosine triphosphate (ATP) levels. RESULTS: GIK animals had less myocardial pH decrease than controls during both ischemia (pH decrease -0.03 vs -0.37, P = .04) and reperfusion (pH decrease -0.10 vs -0.44, P = .05). Neither ATP (74% vs 73% decrease from baseline) nor glucose (27% vs 33% decrease from baseline) varied significantly between groups during ischemia. GIK animals had faster normalization of ATP (100% vs 79% increase from ischemia) and glucose (69% vs 28% increase from ischemia) during reperfusion. CONCLUSIONS: Real-time myocardial metabolic monitoring shows that cardiac pH is improved by GIK during ischemia-reperfusion injury; however, ATP and glucose levels were not significantly enhanced. GIK animals trended toward earlier recovery during reperfusion. Mediators of this metabolic enhancement need to be explored.

Human neurocysticercosis: rightward hemisphere asymmetry in the cerebral distribution of a single cysticercus.

The distribution of single cysticerci between cerebral hemispheres was studied in 227 adult cases of calcified and vesicular neurocysticercosis (NC). A rightward lateralization of calcified cysticerci was significant only in women, whereas vesicular cysticerci were equally distributed in both hemispheres. Factors related with the differences in the inflammatory response and in the regional cerebral blood flow between genders could be involved.

Control of overweight and obesity in childhood through education in meal time habits. The 'good manners for a healthy future' programme.

OBJECTIVE: Our aim is to determine the effect of paced eating, exposure to an educational programme that promotes healthy eating habits and allowing the satiety reflex to limit food intake in controlling weight gain in healthy adolescents. METHODS: Fifty-four healthy individuals consisting of 18 adolescent girls and 36 boys aged 12 ± 2 years were given recommendations for reducing eating rate without changing diet or meal size according to the educational programme 'good manners for a healthy future'. Each participant was provided with a 30-s portable hourglass to pace time between bites. Individuals using and not using the hourglass were placed either into an 'adhering' or a 'non-adhering' group, respectively. Control data were obtained from a similar population. RESULTS: Initially, the adhering group had higher weight compared with the non-adhering group (64.1 ± 13.2 vs. 56.2 ± 11.7 kg). Control group weight was no different from the study group at baseline (56.3 ± 10.3 kg). Weight in the adhering group decreased after the first semester of participation by 2.0 ± 5.7% and after a year by 3.4 ± 4.8%, while the non-adhering group gained weight by 5.8 ± 4.5% and 12.6 ± 8.3%. The control group increased weight after a year by 8.2 ± 6.5%. In total, 18 non-adhering and 14 adhering adolescents completed the study. CONCLUSIONS: This 1-year study shows a statistically significant association between rate of food intake and weight control in adherence to an educational programme directed at developing healthy eating habits. The proposed behavioural training may serve as an option for weight control in adolescents.

Respiratory responses to stimulation of abdominal and upper-thorax intercostal muscles using multiple Permaloc electrodes.

Stimulation of abdominal and upper-thoracic muscles was studied with the long-term goal of improved respiratory care for spinal cord injury (SCI) patients. A 12-channel stimulator and multiple surface and implanted Permaloc electrodes were evaluated in five anesthetized canines. Abdominal stimulation with 100 mA using four bilateral sets of surface electrodes placed on the midaxillary line at the 7th through 13th intercostal spaces and with a closed airway at a large lung volume produced an expiratory tracheal pressure of 109 +/- 29 cm H2O (n = 2, mean +/- standard error of the mean). Similar high pressures were induced with implanted electrodes at the same locations. Upper-thoracic stimulation with 40 mA and four sets of implanted electrodes ventral to the axilla induced inspiratory pressures of -12 +/- 2 cm H2O (n = 5). Combined extradiaphragmatic pacing with an open airway produced a tidal volume of 440 +/- 45 mL (n = 4). The robust respiratory volumes and pressures suggest applications in SCI respiratory care.

Palliative radiotherapy for inoperable carcinoma of the lung: final report of a RTOG multi-institutional trial.

Between June 1973 and February 1979, 409 patients with inoperable advanced non-oat cell carcinoma of the lung were randomized on RTOG protocol 73-02. Three treatment arms were evaluated: 40 Gy split course, 30 Gy continuous course, and 40 Gy continuous course. Patients were also randomized to receive cytoxan or no further therapy following irradiation. Three hundred sixteen patients were evaluable. Palliation of symptoms was achieved in 60% with 1/4 of the patients becoming symptom-free. Complete regression of local and regional tumor was produced in 15% and partial regression in 26%. There is no significant difference between the treatment arms in these objective response rates. Median survival times were approximately 6 months. No significant benefit was demonstrated by the adjuvant use of Cytoxan. Although the number of complete responses produced was relatively small, patients achieving a complete response had a significantly longer median survival than the remaining patients, i.e., 14.5 months versus 6 months. Significant toxicity occurred in fewer than 6% of patients. Radiation pneumonitis counted for the majority of these adverse reactions. Toxicity occurred somewhat more often in the group treated with 40 Gy split course therapy. Implications for further studies are discussed.

The distribution of collagenase in normal rat tissues.

A rabbit monospecific anti-rat uterus collagenase antibody has been used to study the distribution of collagenase in normal rat tissues by immunohistochemical methods. Indirect staining was performed with fluorescein-conjugated goat anti-rabbit immunoglobulin G antibody. The organs studied were brain, lung, myocardium, liver, spleen, kidney, adrenal, testes, uterus, xiphoid cartilage, tail tendon, skeletal (triceps) muscle and skin. Collagenase is widely present throughout the connective tissue structures in all organs examined. The enzyme is apparently bound to collagen fibers, reticulum fibers and basement membranes. The results suggest that control of collagenase activity depends on factors other than the presence of the enzyme in tissues.

Immunohistochemical identification of collagenase in carrageenin granuloma.

The collagenase present in experimental carrageenin granuloma in the guinea pig has been purified to homogeneity in acrylamide gel electrophoresis by a combination of ammonium sulfate salting out and affinity chromatography on Sepharose 4B--collagen-packed columns. The single protein band thus obtained was used as an antigen to obtain a monospecific antibody in heterologous conditions. Several immunodiffusion, immunoaffinity chromatography, and immunoinhibition tests of the antibody against the specific antigen and various possible serum and tissue contaminants suggested that the antibody was specifically directed against the enzyme protein collagenase. Indirect immunohistochemical staining of carrageenin granulomas, samples at different developmental phases with this specific anti-collagenase antibody, revealed that the specific antigenic protein (the enzyme collagenase) is universally present on the extracellular structures at both the collagen-deposition and the collagen-resorption stages. A hypothesis is proposed to account for these findings, namely, that the enzyme collagenase is bound to its substrate (collagen) under both normal and pathological conditions, and that the critical point of control of collagen degradation must be the activation of the collagen-bound enzyme.

Ischemia in experimental acute amebic liver abscess in hamsters.

In experimental acute amebic liver abscess, produced in hamsters by the intraportal inoculation of 1 x 10(6) axenic trophozoites of Entamoeba histolytica strain HM-1, we examined the blood perfusion of the lesions 5, 10, 24 and 72 h after injection of the parasites. India ink introduced into the portal circulation filled all liver vessels but was systematically excluded from even the earlier amebic lesions. The absence of serum proteinase inhibitors from the lesions may allow the participation of amebic proteinases in the causation of tissue necrosis.

Pulsatile versus nonpulsatile reperfusion improves cerebral blood flow after cardiac arrest.

Cardiopulmonary bypass using nonpulsatile flow (NF) is currently advocated for treating refractory cardiac arrest. Although the heart can be revived using cardiopulmonary bypass support, the brain must recover if such therapy is to be considered successful. Previous studies have demonstrated that pulsatile flow (PF) reperfusion can improve neurologic outcome compared with NF reperfusion after cardiac arrest. The purpose of this study was to assess cerebral perfusion and oxygen consumption during either PF or NF reperfusion after cardiac arrest. Dogs (n = 22) underwent a 15-minute cardiac arrest followed by 1 hour of either PF or NF reperfusion. Microsphere techniques were used to assess cerebral perfusion and oxygen consumption at 3, 15, and 60 minutes of reperfusion. Mean arteriovenous gradients and total brain flows were similar in both groups. However, cerebral oxygen consumption was significantly improved at 3 minutes of reperfusion with PF versus NF (1.8 +/- 0.3 versus 0.9 +/- 0.3 mL O2.dL-1.min-1, respectively; p < 0.05). These results were coincident with improved gray-to-white flow ratios at 3 minutes of PF versus NF reperfusion (5.2 +/- 1.0 versus 2.0 +/- 0.3, respectively; p < 0.05). There were no statistically significant differences in brain perfusion variables by 15 minutes of reperfusion. However, a relative hyperemia was exhibited at 15 minutes of NF versus PF reperfusion, which suggests nutrient flow was insufficient during early NF versus PF reperfusion. In conclusion, PF reperfusion can better restore cerebral blood flow and oxygen consumption than can NF reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Extraction and partial characterization of a low molecular weight collagenase from normal rat kidney.

A matrix metalloproteinase with selective affinity for collagen was identified and partially purified from normal rat kidney. A two-step purification procedure consisting of gel filtration and affinity chromatography on Sepharose 4B-collagen resulted in an increase in specific activity of more than 3,000 times. The partially purified collagenase cleaved type I collagen and also showed low gelatinolytic activity. The enzyme required Ca2+ and revealed a neutral pH optimum; it was not inhibited by thiol or serineprotease inhibitors. Its activity was fully blocked using recombinant tissue inhibitor of metalloproteinases-1. Using SDS-PAGE and zymography, the estimated Mr of the collagenase was 16.5 x 10(3).

Phagocytosis and proteinase activity are not related to pathogenicity of Entamoeba histolytica.

To examine the relationship between phagocytosis, proteinase activity and pathogenicity of axenically grown trophozoites of E. histolytica of strain HM-1:IMSS four different cultures were used: 1) a culture preserved in our laboratory for over 4 years, that lost its pathogenicity 3 years ago; 2) a culture passaged several times through hamster liver, that lost its pathogenicity recently; 3) a highly virulent culture supplied by another laboratory; and 4) amebas recovered from hamster liver abscesses caused by the latter culture. Phagocytosis was measured as erythrophagocytosis. Proteinase activity was determined on azocasein. Pathogenicity was defined as the capacity to cause liver abscesses in hamsters. A negative correlation was found between phagocytic activity and pathogenicity, since amebas unable to cause liver abscesses had the highest phagocytic activity whereas those recovered from liver abscesses had the lowest phagocytic activity. The percent of phagocytic amebas increased progressively in all cultures through a 2-month observation period. No correlation was found between the level of proteinase activity and pathogenicity. It is concluded that neither phagocytosis nor proteinase activity are adequate markers of amebic pathogenicity.

Phenotypic heterogeneity in the expression of a 30 kDa cysteine proteinase in axenic cultures of Entamoeba histolytica.

A polyclonal antibody raised against a purified approximately 30 kDa cysteine proteinase derived from extracts of axenically grown trophozoites of E. histolytica strain HM-1:IMSS was used to stain 72 h cultures of the same amebas by indirect immunofluorescence. Fluorescence was limited to the outer membrane of the parasite and was either uniformly distributed or more condensed on a segment, at times on a single point of the membrane. In relation to the intensity of fluorescence staining, three distinct amebic populations were present: negative, weakly stained and intensely stained. The relative numbers of these three groups remained quite constant for at least one year under the same culture conditions. Flow cytometry was used to quantitate simultaneous variations in amebic size and intensity of fluorescence at various times after different treatments. Amebic size was registered in three levels: small (< 7 microns), medium (7-20 microns), and large (> 20 microns). Staining intensity was measured in arbitrary units. Exposure to 100% fresh hamster serum, phagocytosis of erythrocytes, exposure to cysteine proteinase inhibitors E-64 and cystatin, and to calmodulin antagonist W-7, resulted in various modifications of the phenotype of amebas in very short time periods. We conclude that the expression of the membrane approximately 30 kDa cysteine proteinase in axenic amebic cultures is phenotypically heterogeneous, and that such heterogeneity is modulated and not constitutive.