Problems and pitfalls in the assay of pentamidine. Implications for clinical use.
Explore the source record for details and available documents.
Chromatography, High Pressure Liquid↗
Biomedical subjects
L Henry
Publications and source records attributed to L Henry.
Pericapillary collagen in the human thymus: implications for the concept of the 'blood-thymus' barrier.
The deposition of collagen in the walls of capillary-size blood vessels was studied in 95 human thymuses with respect to the site of deposition, extent of the change and relation to age and degree of involution. When examined by electron microscopy the collagen was found to be situated between the 2 basement membranes of the so-called 'double-layered' capillaries characteristic of the thymus of many species. This results in the formation of substantial 'collars' of collagen around a proportion of the blood vessels examined. Few such collars are seen before birth, but their number and thickness increase markedly during the 1st year of life. The relationship of these changes to the degree of involution is less apparent. The significance of these changes to thymic structure and function is discussed in relation to cell traffic through the thymus and the postulated 'blood-thymus barrier', the existence of which is seen to be in some doubt.
Aging↗
Morphology of rejection in experimental pancreas transplantation and its modification by cyclosporin A administration.
Histology of pancreas transplant rejection is complicated by non-specific appearances related to undrained exocrine secretions. Using a rat model of pancreas transplantation with exocrine drainage into the urinary tract, morphology of acute rejection has been studied with minimal interference from non-specific change. Unmodified acute rejection was complete after 7-9 days. Intralobular lymphocytic infiltration, which differentiated allografts from isografts, was present 5 days after transplantation and lymphocytic infiltration of islets and blood vessel walls developed between 5th and 7th days. Cyclosporin A immunosuppression of allografts resulted in marked attenuation of the cellular infiltrate. The nature of the infiltrate and its suppression with cyclosporin A indicated an allograft reaction.
Acute Disease↗
p53 expression in human breast cancer related to survival and prognostic factors: an immunohistochemical study.
In a study of 90 breast cancer patients, tumour p53 protein expression was determined by immunohistochemistry using the monoclonal antibody PAb1801. Patient lymph node status and Bloom's grade were determined, and both oestrogen and progesterone status assessed, also by immunohistochemistry. Lymph node status, tumour grade, and progesterone receptor status all had a significant influence on survival. Patients with p53-positive tumours showed poorer survival but this did not achieve significance. p53 protein expression showed a significant relationship to high tumour grade and a weak correlation with negative oestrogen receptor status. The data suggest that p53 protein expression may be a marker of more aggressive carcinomas but that the prognostic power of expression is likely to be weak and unlikely, therefore, to be of clinical value. The results do not resolve whether detectable p53 protein expression represents a random product of dedifferentiation, or an important feature of the malignant phenotype, playing a key role in tumour behaviour. The number of patients in our study is small, however, and investigation of a larger series is clearly indicated.
Antibodies, Monoclonal↗
Pulsed dye laser lithotripsy of bile duct stones.
Efficacy and safety of pulsed dye laser lithotripsy was tested in 25 consecutive patients in whom bile duct stones could not be extracted after endoscopic sphincterotomy. The patients had one to six (mean, 1.8) bile duct stones (diameter, 10-35 mm; mean, 18 mm) located in the common bile duct (18 cases), the intrahepatic bile ducts (6 cases), or in a long cystic duct stump (1 case). Different approaches were tested depending on the presence of a T tube and on the localization of the bile duct stones. When a T tube was present (7 cases), the lithotripsy was performed under direct vision using a choledochoscope inserted through the T-tube tract. In 18 patients without a T tube in place, the lithotripsy was performed under fluoroscopy using a retrograde approach in case of common bile duct stones (14 cases) or under choledochoscopy using a percutaneous transhepatic approach in case of intrahepatic bile duct stones (4 cases). Fragmentation of all the bile duct stones and a complete bile duct clearance were obtained in all 11 cases with procedures performed under direct vision as compared with only 5 of 14 cases with procedures under fluoroscopic control. Moreover, 6 of the 9 failures using the latter approach were offered another session using a choledochoscope inserted through a percutaneous transhepatic tract and were also successfully treated. No complication related to the laser beam was noted. It is concluded that pulsed dye laser lithotripsy of bile duct stones (that are unable to be removed by standard endoscopic techniques) is safe and efficacious provided that it is performed under direct vision. Technical refinements are needed before this procedure can be reliably performed under fluoroscopy.
Aged↗
Fatal pulmonary fat embolism during total hip replacement due to high-pressure cementing techniques in an osteoporotic femur.
High-pressure cementing techniques, involving the use of a cement gun and cement restrictor, placed within the femoral medullary cavity, are commonly used to secure the femoral component of hip arthroplasties. Such techniques have been shown to be important in maintaining the integrity of the bone-cement interface and also the integrity of the cement itself. This case report illustrates that such techniques are not without complications.
Cementation↗
Effect of different body-exercise modes on the rate response of the temperature-controlled pacemaker Nova MR.
In order to evaluate the effect of different modes of physical exercise on the rate response of the temperature-controlled Nova MR, parameters such as temperature behaviour and correlation of work load to pacing rate were investigated using different types and protocols of stress testing. This study considered 21 patients (age: 66 +/- 12 y). The indications for the Nova MR were AV block (n: 14) and sick sinus syndrome (n: 7). The patients performed two different types of exercise (treadmill n: 13, bicycle n: 14) based on different protocols. We registered the surface ECG, pacing rate, exercise time, and (via data transmission by the RX 2000 programmer) blood temperature and pacing rate. An adequate rate response could be achieved with all the different types of exercise and protocols using more sensitive program settings. The type of stress testing used to adjust or evaluate the Nova MR seems to be secondary, although cycling as compared with treadmill exercise resulted in a slightly weakened reaction of temperature and pacing rate. Our investigations revealed a good correlation between work load and pacing rate independent of the type of stress testing. The initial DIP (48%) is not a constant phenomenon and showed inter- and intraindividual variations. Impressive psychological influences also exhibited an effect on temperature and pacing rate, sometimes preventing a DIP response. During exercise at lower work loads (under 50 watts, shorter than 3-4 min) the rate response of the Nova MR--without any detected DIP--is often delayed due either to a decrease or to a late and flat increase in temperature. An additional fast-reacting sensor could be advantageous in triggering the initial rate response in such cases.
Aged↗
Immunoglobulins in Hassall's corpuscles of the human thymus.
Ninety nine human thymuses were examined immunohistochemically for the presence of immunoglobulins G, A, M. D and E, light-chains, secretory component and albumin in the cells of Hassall's corpuscles. Igs G, A, M and secretory component were present. These showed a rise after birth until the age of 20 years and also increased with the degree of involution, falling when involution became complete. Albumin was also consistently demonstrated. There was a degree of correlation between the presence of Igs and production of Igs G, A and M by plasma cells in the thymic medulla. There was a close correlation between the amounts of IgA and secretory component in the cells of Hassall's corpuscles and the thymus may have to be regarded as a part of the secretory-IgA system. Light chains of the immunoglobulin molecule were also present, with lambda predominating over kappa, possibly reflecting the same kappa/lambda ratio found with thymic immunoglobulin production. No IgD or IgE was demonstrated. The presence of albumin may represent a passive uptake of protein in senescent cells but a more active uptake of Igs, particularly IgG and IgA, could be postulated. The production of Igs in the thymus and their presence in Hassall's corpuscles could be of significance in the maturation and regulation of the immune response.
Adolescent↗
Monoclonal antibodies detect and stabilize conformational states of smooth muscle myosin.
Antibodies with epitopes near the heavy meromyosin/light meromyosin junction distinguish the folded from the extended conformational states of smooth muscle myosin. Antibody 10S.1 has 100-fold higher avidity for folded than for extended myosin, while antibody S2.2 binds preferentially to the extended state. The properties of these antibodies provide direct evidence that the conformation of the rod is different in the folded than the extended monomeric state, and suggest that this perturbation may extend into the subfragment 2 region of the rod. Two antihead antibodies with epitopes on the heavy chain map at or near the head/rod junction. Magnesium greatly enhances the binding of these antibodies to myosin, showing that the conformation of the heavy chain in the neck region changes upon divalent cation binding to the regulatory light chain. Myosin assembly is also altered by antibody binding. Antibodies that bind to the central region of the rod block disassembly of filaments upon MgATP addition. Antibodies with epitopes near the COOH terminus of the rod, in contrast, promote filament depolymerization, suggesting that this region of the tail is important for assembly. The monoclonal antibodies described here are therefore useful both for detecting and altering conformational states of smooth muscle myosin.
Animals↗
Two distinct immunogenic epitopes on the alpha chain of human T cell antigen receptor.
Monoclonal antibodies (MAb) to human T Cell Antigen Receptor (TCR) have been used to study the structure and function of TCR. Using purified alpha/beta heterodimeric protein, we have generated two MAb against human TCR alpha protein. The two MAb, alpha F1 and alpha F2, recognized amino acid residues 141-159 and 212-231 of the constant region of the alpha chain TCR. Although neither MAb reacted with viable T cells, both antibodies immunoprecipitated TCR alpha/beta heterodimer from HPB-ALL, Jurkat, PBL and a 32 kDa in vitro translation product of alpha chain cDNA. These antibodies have been shown to be useful in the immunohistochemical staining of human tissues. These two MAb, together with other anti-framwork MAb to TCR, should provide valuable reagents in the study of TCR and clinical classification of T cell lineage neoplasms.
Antibodies, Monoclonal↗
Hemorrhagic myocardial infarction complicated by free wall-rupture: a case associated with unusual clinical features following intravenous thrombolytic therapy.
A patient is described who developed a systolic murmur soon after she was administered intravenous thrombolytic therapy for acute myocardial infarction. She died and autopsy revealed extensive hemorrhagic myocardial infarction and a free-wall rupture. A review of the literature suggests that this may be an unusual complication of thrombolytic therapy.
Aged↗
Pseudomembranous trigonitis of the bladder: hormonal aetiology.
Fourteen formalin fixed and paraffin wax embedded biopsy specimens from 10 women (age range 34-68) presenting with pseudomembranous trigonitis were studied using a combination of anti-oestrogen receptor monoclonal antibodies in an avidin-biotin immunoperoxidase technique. All epithelial areas showing vaginal metaplasia exhibited staining confined to the nucleus in the basal and parabasal layers of the squamous epithelium while no staining was encountered in adjacent trigonal transitional epithelium included in nine of the biopsy specimens. The selective expression of nuclear oestrogen receptor in trigonal epithelium affected by vaginal metaplasia in a distribution similar to that reported in vaginal epithelium by other workers lends further support to oestrogen mediated aetiology in this condition and is consistent with an embryological derivation of the trigone, distinct from that of the rest of the bladder.
Adult↗
Men's and women's mortality in the past.
This is a historical survey of adult mortality in western Europe from 1625 to 1900, with a focus on the state of women's health during this period. The author attempts to determine whether "women's health in the past was more precarious than it is to-day...[and assesses] the influence of maternal mortality on the excess mortality of women during part of their adult lives." Mortality comparisons are made among female age groups, countries, and historical periods.
Demography↗
An A-chain ricin immunotoxin targeted against rat class II major histocompatibility complex molecules. In vitro and in vivo effects.
Studies reported here have demonstrated that an antirat class II major histocompatibility complex molecule A-chain ricin immunotoxin could specifically remove, in a dose-dependent manner, the cells capable of stimulating the rat mixed lymphocyte reaction, an in vitro model of transplant rejection. It was further demonstrated that administration of a monoclonal antibody against class II major histocompatibility complex molecules to isolated rat pancreas grafts by hypothermic perfusion resulted in the targeting of cells bearing class II major histocompatibility complex molecules. But administration of the immunotoxin to isolated pancreases in a similar manner did not prolong their survival when allografted across a major histocompatibility barrier.
Animals↗
Clinical experience with new leads.
Recent developments in cardiac pacemaker electrodes have resulted in significant benefits to the group of pacemaker patients as a whole. The results of analysis of 2,818 chronic pacemaker electrodes are presented. These electrodes are divided into major categories according to their particularities: platinum iridium, elgiloy, carbon-tip, anodized platinum and granulated iridium-platinum. All leads were in the ventricular position. The results of acute and chronic threshold measurements reveal that carbon-tipped electrodes appear to have the most favorable overall characteristics. This will have a major influence on long-term pacing practices.
Carbon↗
A DNA element responsible for the different tissue specificities of Friend and Moloney retroviral enhancers.
The transcriptional enhancers of the Moloney murine sarcoma virus (MuSV) and Moloney murine leukemia virus (MuLV) have different cell type specificities from that of the Friend MuLV. While the three enhancers are approximately equally active in erythroid cells, the Moloney MuSV and Moloney MuLV enhancers are 20- to 40-fold more active than the Friend MuLV enhancer in T-lymphoid cells. Using mutant enhancers, we have shown that specific differences between the nucleotide sequences of the Moloney MuSV and Friend MuLV enhancers are responsible for their different activities in T cells. Our data allow the localization of a DNA element, repeated several times within the enhancer, which modulates the activity of the enhancer in T cells without affecting it in erythroid cells. This element therefore appears to be one of the determinants of the tissue specificity of the enhancer.
Base Sequence↗
The fertility of hypothyroid male mice.
Male mice homozygous for the hypothyroid gene mutation were compared with normal siblings to determine whether hypothyroidism induced infertility by impairing sexual behaviour. In addition, the fertility of the hypothyroid mice was examined. The experimental results provide unequivocal evidence that genetically-induced hypothyroidism in male mice does not impair sexual behaviour or cause infertility.
Animals↗
Pediatric home infusion therapy.
Explore the source record for details and available documents.
Adolescent↗