Determining what immune cells see.
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Biomedical subjects
Publications and source records attributed to M Hoffman.
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Injury within the myocardium may cause disturbances of the intraventricular conduction and may be manifested by altered spectrum of the QRS complex. The purpose of this report is to indicate the existence of microvolt early waves appearing at the beginning of the QRS complex in some postinfarction patients with low ejection fraction. The method used incorporated the high resolution ECG recording, where the "pyramid" electrode location was applied. Results indicated a relationship between high frequency potentials, QRS duration time, and ejection fraction, as well as dependence between ventricular tachycardia/fibrillation (VT/VF) occurrence and early and/or late ventricular activity. In patients with secondary VT/VF where early and late potentials were found, the ejection fraction (EF) was the lowest (26 +/- 15%). Early waves appeared more often in patients with secondary VT/VF (30%) compared with those with primary VT/VF (8%). In patients without VT/VF and without myocardial infarction (MI) early potentials were not remarked. In those patients late potentials also appeared less often. It could be concluded that existence of early potentials, late activity, and significant prolonged total ventricular activation time is associated with wide dispersion and nonuniform delay of the electrical activity within the myocardium as well as with serious lowering of the ejection fraction. Therefore, existence of early waves seems to be a significant diagnostic factor for the poor hemodynamic condition as well as a serious warning for the recurrent late ventricular tachycardia/fibrillation.
Although blue-green molds of the genus Penicillium are ubiquitous in the human environment, invasive penicilliosis is uncommon and primarily encountered among immunosuppressed patients. A patient with HIV infection who died of severe necrotizing esophagitis caused by Penicillium chrysogenum is reported and the relevant English language literature on human penicilliosis is reviewed. Although infectious esophagitis is commonly associated with AIDS, Penicillium esophagitis has not been described in such patients.
Using denture acrylic pieces coated with either whole human stimulated saliva or oral streptococci, the binding ability of three different Candida albicans strains was investigated. The C. albicans strains include a clinical isolate with the commonly observed, smooth, round colonial morphology (strain 613p), a morphological variant spontaneously derived from the clinical isolate strain 613p (strain 613m1BK) and a clinical isolate from an oral lesion that was also a morphological variant upon primary isolation (strain 228). Levels of adhesion to the acrylic pieces were determined radiometrically using C. albicans cells metabolically labelled with [35S]-methionine. Whole stimulated saliva significantly increased the binding of all strains compared to uncoated acrylic. However, the level of binding of strain 613p to saliva-coated acrylic was significantly greater than the levels observed for the morphological variant strain 613m1BK. Coating acrylic pieces with either Streptococcus sanguis NCTC 10904, Strep. mutans GS-5 or Strep. sobrinus ATCC 27352 instead of saliva resulted in significantly greater binding by strain 613p compared to uncoated acrylic. Pre-coating the acrylic with the oral streptococci did not significantly increase the binding of morphological variant strains 613m1BK and 228 compared to uncoated acrylic. In general, preincubation of adherent streptococci with sucrose to induce the synthesis of extracellular carbohydrate polymers did not significantly increase the binding levels of the C. albicans strains above those observed using streptococci in buffer alone. Compared to its parental strain 613p, morphological variant strain 613m1BK adhered poorly to denture acrylic coated with either salivary constituents or oral streptococci, while strain 228 adhered to the same substrates at an intermediate level. Furthermore, physical disaggregation of clusters of the morphological variant strain 613m1BK did not appear to increase its binding capacity to saliva-coated denture acrylic. The effect of whole stimulated saliva on the adherence of C. albicans 613p to a variety of plastic substrates in addition to denture acrylic was examined. Overall, saliva pre-coating of the various plastics promoted C. albicans 613p adhesion. The adhesion of strain 613p to denture acrylic coated with whole stimulated saliva from each of five different donors or with parotid and submandibular/sublingual saliva from each of two donors was also examined. Regardless of donor, a coating of whole stimulated saliva significantly increased the binding of strain 613p to denture acrylic compared to uncoated acrylic. In addition, a coating of parotid saliva significantly increased the binding of strain 613p to denture acrylic compared to submandibular/sublingual saliva.
Of 535 consecutive cases of acute leukaemia diagnosed in the Cape Province between 1978 and 1985, demographic data are incomplete in 75 black patients and they have had to be excluded from the spatial analysis. Of the remaining 460 cases, 223 (48.5%) occurred in white patients and 237 (51.5%) in those of mixed ancestry, classified as coloureds according to the Population Registration Act No. 30 of 1950. The average incidence was 2.12, 1.37 and 0.58/100,000 for whites, coloureds and blacks respectively. There was no temporal trend in the incidence of acute leukaemia between the three race groups. The median age for whites was 30 years and for the coloureds was 15 years, which is comparable to the 16 years for the black patients. The two-peak age distribution for leukaemia was seen in the white group, but was absent in the other two groups. This is accounted for by a different distribution in non-lymphoblastic as opposed to lymphoblastic subtypes. Furthermore, there was a disproportionately high frequency of acute progranulocytic leukaemia in the black patients, whereas the white and coloured groups were similar. There was a single, clearly defined macro-scale cluster restricted to white patients in Statistical Region 17 (SR-17). This exploratory study provides the first epidemiologic data for acute leukaemia in the Cape Province. It needs to be extended in order to verify these observations under more controlled circumstances and to seek evidence for some environmental factors that may account for the geographical cluster.
Following intraperitoneal administration, the lymphatic targeting of polyacrylic nanoparticles has been evaluated in thoracic duct cannulated rats. The dosage forms administered consisted of carbon-14 polyhexylcyanoacrylate nanoparticles (PHCA) and polymethylmethacrylate (PMMA) nanoparticles. The carbon-14 concentrations were much higher in the excreted thoracic lymph than in the blood for both types of particles. The most dramatic results were found in the mediastinal nodes since the carbon-14 concentrations of rats receiving PHCA and PMMA nanoparticles by the ip route were 70- to more than 2000-fold higher than in the corresponding nodes of animals treated by the intravenous route. This potential lymphatic targeting could prove valuable in cancerology to treat tumors that metastasize in the peritoneal cavity or via lymphatic pathways such as colon carcinomas.
Platelets can be damaged easily or activated during isolation, making them unsuitable for functional studies. The most common technique for isolating platelets involves centrifugation. Although gentler methods have been devised to isolate platelets by density gradient centrifugation or electrophoresis, these techniques either result in a relatively dilute platelet preparation or are time-consuming. A simple, gentle technique for isolating concentrated platelet preparations for experimental or clinical use is reported. Freshly drawn whole blood was spun over a commercially available density gradient medium for 30 minutes. The mononuclear cell layer (which also contains most of the platelets) was collected and nucleated cells were pelleted by centrifugation. The recovery of platelets was about 60%. Contamination with leukocytes was less than 1%, and the platelet concentration was about 130% of blood concentration. Higher concentrations can be obtained if more whole blood is layered onto the Mono-Poly Resolving Medium (MPRM; Flow Laboratories, McLean, VA). About 10% of the platelets expressed the activation marker GMP-140 by flow cytometric analysis. They could be activated by thrombin so that 70% to 90% of the platelets expressed GMP-140. Thus, this technique can rapidly and easily yield a functionally intact platelet preparation. This preparation can be purified again if needed. No specialized skills or equipment are needed. A significant advantage of the method is that platelets can be obtained from thrombocytopenic patients in final concentrations that are high enough to use for platelet function testing.
1. The haemodynamic effects of S-12968-(-), a new dihydropyridine calcium entry blocker (enantiomer of S-11568), were compared with those of the stereoisomer, S-12967-(+), nifedipine, and sodium nitroprusside. 2. A first experiment was performed in conscious, young male rats chronically implanted with femoral artery and vein cannula and repeated in rats previously treated with vitamin D3 and nicotine. Such treatment produces marked vascular calcium overload, especially of the compliance arteries, with no overt sign of toxicity as far as can be judged from the plasma profile. 3. In conscious rats the hypotensive effects of S-12968-(-), nifedipine and sodium nitroprusside were of similar potency. The falls in blood pressure produced by nifedipine and sodium nitroprusside were accompanied by reflex tachycardia which was less marked in the vascular calcium overload model. S-12968-(-) did not induce reflex tachycardia. S-12967-(+) increased blood pressure in both models. 4. A second experiment was performed in open-chest pentobarbitone-anaesthetized rats with electromagnetic flowprobes on the ascending aorta. In controls the falls in blood pressure produced by low doses (0.1 and 0.3 mg kg-1, i.v.) of S-12968-(-) were accompanied by falls in total peripheral resistance. The higher dose (1 mg kg-1, i.v.) of S-12968-(-) produced no change in total peripheral resistance, and in rats pretreated with vitamin D3 and nicotine, cardiac output fell. 5. In conclusion, S-12968-(-) appears to have a dual action and to lower blood pressure at higher doses at least in part by a cardiac effect. This phenomenon is more pronounced in rats pretreated with vitamin D3 and nicotine.6. S-12967-(+) resembles a calcium channel activator in this model.
The safety and efficacy of patient-controlled analgesia for the long-term control of cancer pain was tested prospectively. Respiratory rates, mental status, and pain relief were recorded at baseline and compared with those during the study period. Patients had a lower analgesic demand (i.e., self-administered less morphine during the nighttime); specifically, dosing declined 48% from the daytime level. Respiratory rates did not change appreciably during the study and no cases of significant respiratory depression were encountered. Patients self-administered sufficient morphine to produce adequate but not complete pain relief in almost all trials. Pain relief was safely achieved by both intravenous and subcutaneous routes of administration in both the inpatient and outpatient settings. Mean 24-h morphine use stayed relatively constant even for patients receiving more than 2 weeks of treatment. In conclusion, patient-controlled analgesia is effective and safe therapy for the long-term control of severe cancer pain.
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This review summarizes basic pathophysiology, epidemiology, classification and theories on the etiology of osteoporoses. Diagnostic, preventative and therapeutic aspects are discussed including the use of hormones and hormone analogues (estrogen, progestins, calcitonins, anabolic steroids), calcium, fluoride, bisphosphonates, vitamins D and their metabolites and the recently proposed "coherence therapy". Reference is made to new compounds under study including imidazoquinazolinones, methylxanthines and benzothiophenes.
The cardiopulmonary support system is an extracorporeal device that allows for rapid cardiopulmonary support of the critically ill patient in the intensive care unit. It provides immediate and complete support of cardiac and pulmonary functions to maintain perfusion to vital organs in patients who are severely physiologically compromised (eg, in cardiogenic shock, adult respiratory distress syndrome or pulmonary edema). Successful cardiopulmonary support requires systemic anticoagulation, percutaneous venous and arterial cannulation and careful monitoring by the critical care team to maintain adequate tissue perfusion and oxygenation. Although patient mortality can occur secondary to bleeding, embolism or sepsis, this technique provides life-sustaining circulatory and respiratory support until definitive treatment can be initiated.
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