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Biomedical subjects

R David

Publications and source records attributed to R David.

At least 181 records · Page 10Linked to original sources

Biochemical and morphological investigations of the toxicity of a Capmul preparation and a bile salt-EDTA solution in patients with bile duct stones.

Seventeen patients with bile duct calculi were treated alternately with a preparation of glycerol octanoate and a bile salt-EDTA solution via a nasobiliary tube. Of 14 patients (group I), it was necessary to operate on four immediately after irrigation therapy, success resulted from this conservative therapy in eight (57%) cases and two were unchanged. Laboratory investigations showed a decrease in zinc and copper concentrations in the serum. Of the patients 50-60% suffered from vomiting and diarrhea. For three patients (group II), there was an interval of 6-26 days between the end of the therapy and operation. Histological findings in the patients in group I and II subjected to operation included acute ulcerative and chronic inflammation in gallbladder and common bile duct walls. Since the alterations were of minor degree in four of the seven patients who subsequently underwent surgery the risk of irrigation therapy seems to be acceptable.

Aged↗

[Non-Hodgkin's malignant lymphoma. Therapeutic value of autologous bone marrow transplantation].

Twelve patients with non-Hodgkin malignant lymphoma of poor prognosis were treated with heavy chemotherapy of the TACC type (cyclophosphamide 45 mg/kg/day i.v. X 4; cytosine arabinoside 200 mg/m2/12 hours i.v. X 7; 6-thioguanidine 100 mg/m2/12-hourly p.o X 7 and CCNU 200 or 250 mg/m2 p.o. single dose) followed by autologus bone marrow transplantation (853 to 20.000 CFUc/kg). The patients were divided into 2 groups depending on whether they received an induction treatment for large visible tumoral mass (group I: 3 initial presentations, 3 relapses) or a consolidation treatment for small residual tumour (group II: 6 complete and 1 partial remissions). The results show that autologous bone marrow transplantation shortens the duration of the therapeutic aplasia. White cell (greater than 10(9)/l) and platelet (greater than 50.10(9)/l) recovery was observed on days 12 (range 9-19) and 14 (range 8-27) respectively. In group I, 1 patient died of myocardial TACC toxity and acute renal failure on tumoral kidney; there were 2 failures and 3 complete remissions (8, 21, 45 + months). Remissions occurred in patients treated initially; the overall survival since diagnosis was 48+, 48+ and 60+ months. In group II patients there were 1 failure and 5 complete remissions persisting after a 2+ months to 30+ months follow-up; the overall survival was 23+, 24+, 27+, 42+ and 70+ months. The 3 failures in the series occurred in circumstances suggesting contamination of the cryopreserved bone marrow by tumoral cells. The toxicity, largely due to infection, of the TACC-bone marrow transplantation combination was tolerable. It was clearly lower in group II (6 patients, no septicaemia) than in group I (5/6 patients with septicaemia). These preliminary results confirm that there is room for autologous bone marrow transplantation in highly malignant non-Hodgkin lymphomas, particularly during complete remissions to facilitate the use of an aggressive consolidation chemotherapy.

Adult↗

Outcome in neonates with convulsions treated in an intensive care unit.

Neurological and developmental outcome was assessed in 131 survivors of neonatal seizures aged 1 to 5 years who had been treated in a single intensive care unit from 1976 to 1979. Half the children had been born at less than 37 weeks' gestational age, and 28% at 31 weeks or less. Fifty-one children were normal on examination, 17 had minor abnormalities, 25 had moderate disabilities, 30 had severe disabilities, 6 had died because of profound neurological deficits, and 2 could not be located. Recurrent nonfebrile seizures had developed in 26 children. Most children with motor handicaps or visual loss were intellectually retarded, but 10 of 15 children with bilateral hearing loss were intellectually normal. Of 77 children whose seizures were caused by a hypoxic-ischemic insult, 41 developed moderate or severe disabilities. As determined by multivariate analysis, significant neonatal predictors of poor outcome in this group included seizures with late onset, tonic seizures, and seizures lasting for many days. Although seizure frequency and neonatal mortality associated with seizures were greatest in very premature infants, the outcome in premature infants who survived was not significantly different from that of term infants.

Brain↗

Siliceous deposits in human urinary calculi--an E. M. study.

Silica calculi in man are extremely rare; only 12 cases have been reported. In an electron microscopic study of human urinary stones, siliceous deposits were encountered in three out of 180 stones as a discrete component of stones. There were no histories of magnesium trisilicate administration in these cases. Morphology of the deposits was distinctive from any other components of the stones and bore some resemblance to animal silica calculi. Siliceous deposits in human urinary stones appear to be more common than generally recognized.

Electron Probe Microanalysis↗

Delayed kinetics of recovery of haemopoiesis following autologous bone marrow transplantation. The role of excessively rapid marrow freezing rates after the release of fusion heat.

Thirty-five patients were treated by intensive chemotherapy and/or whole-body irradiation followed by reinjection of cryopreserved autologous bone marrow. In 8 patients the kinetics of recovery of haemopoiesis was delayed (recovery to 10(9) leucocytes/litre beyond day 27 and recovery to 50 X 10(9) platelets/litre beyond day 25). This delay was directly responsible for the death of 3 patients and contributed to a fatal outcome in 2 others (mortality rate 9-14%). Retrospective analysis of these 8 cases revealed that failure of autologous transplantation was associated with poor recovery of CFUc, which was in turn related to an excessively rapid freezing rate after the release of fusion heat. Recovery of CFUc to 50% or more was achieved in 100% of cases when the freezing rate was less than 5 degrees C/min, 45% for freezing rates between 5 and 10 degrees C/min and 22% when the freezing rate exceeded 10 degrees C/min (n = 71, P less than 0.001). There was an inverse linear or logarithmic relationship between CFUc recovery and freezing rate after the transition phase (r = -0.46, r = -0.43, P less than 0.001). The quantity of nitrogen introduced into the freezing chamber to annul the fusion heat must therefore be calibrated with accuracy so that the desired shortening of the transition phase will not be accompanied by an overly marked increase in the freezing rate, which would result in the destruction of stem cells. To ensure an adequate freezing rate, it is crucial to monitor the temperature continuously in each sample of bone marrow during the freezing process. This study also suggested that other factors may have interfered with the kinetics of recovery after autologous bone-marrow transplantation. These factors include myelofibrosis, the presence of an Australia antigen and administration of compounds that are toxic for the bone marrow after reinjection of cryopreserved marrow. However, the responsibility of these factors cannot be stated with certainty.

Adult↗

Glaucomatous blindness in the Negev: a descriptive study of age, sex, and ethnic patterns.

Two sources of data (a blind register and the records of a glaucoma clinic) were used to study the age, sex, and ethnic characteristics of sufferers of glaucomatous blindness in the Negev region of Israel. Glaucoma was found to be the cause of blindness relatively infrequently (10% of eyes) among the registered blind population. The rate of blindness from glaucoma in the population was 0.38/1000. Glaucomatous blindness affected more males than females and more individuals of Eastern and Western origin. A steep gradient of increasing number of blind with advancing age was found in both sexes and both ethnic groups, but the gradient was steeper in males and females of Eastern origin. These findings are consistent with the pattern expected of a developing country and represent the first descriptive profile of the pattern of personal characteristics of sufferers from glaucomatous blindness in this region. The ethnic pattern resembles what is known about the natural history of glaucoma in pigmented and nonpigmented races.

Adult↗

Dense-core matrical mitochondrial bodies in oncocytic adenoma of the thyroid.

Single and/or multiple, round and homogeneous electron-dense bodies occurred within the mitochondrial matrix of a mitochondrion-rich follicular adenoma of the thyroid. These non-membrane-bound bodies varied greatly in size and often occupied a large portion of the mitochondrion. They were present in normal-sized or large mitochondria that exhibited cristolysis and/or dilatation of the intracristal space of the residual cristae and formation of intramatrical myelin figures. The globule-containing mitochondria frequently exhibited bundles of parallel intramatrical filamentous inclusions that were 6 to 8 nm in width and were randomly arranged in clusters. Megamitochondria up to 4.4 micrometers in widest diameter occurred in a frequency of one to two per cell and they displayed similar bundles of filamentous inclusions. This evidence of electron-dense bodies in non-steroid-hormone-secreting cells suggests that the bodies result from nonspecific mitochondrial reaction to injury rather than being inclusions specific for steroid-synthesizing cells.

Adenoma↗

Fatal barium embolization due to incorrect vaginal rather than colonic insertion. An ultrastructural and x-ray microanalysis study.

Fatal generalized barium sulfate (BaSO4) embolization followed erroneous vaginal insertion of the enema tip intended for colon examination. Light microscopy revealed the presence of swollen, granular reticuloendothelial cells in most visceral organs such as lung, liver, spleen, bone marrow, kidney, and brain. Transmission electron microscopy showed the reticuloendothelial cells loaded with uniformly electron-dense granules of various sizes. Scanning electron microscopy equipped with an energy-dispersive x-ray analyzer confirmed the BaSO4 composition of these granules when unstained paraffin sections of different organs mounted on glass slides without coverslips were examined. The use of the technique of x-ray microanalysis is recommended when absolute identification of inorganic material in human organs is needed. The technique can be used directly on routine paraffin-embedded material mounted on glass slides as well as with material expressly prepared.

Age Factors↗

Extrahepatic biliary obstruction and liver failure secondary to myeloma of the pancreas.

An unusual case of multiple myeloma in an 88-year-old patient is described. Besides skeletal involvement, there was myeloma of the thoracic and abdominal lymph nodes and of the liver and pancreas. In the pancreas, the myeloma extensively involved the head and body, and on computerized tomography scan was suggestive of a pancreatic carcinoma. The myeloma caused extrinsic compression of the common bile duct, resulting in severe jaundice and hepatic and renal failure. To the author's knowledge this is the second such case of pancreatic myeloma causing extrahepatic biliary obstruction.

Acute Kidney Injury↗

beta-Fibrillary bodies in low-grade adenocarcinoma of parotid gland: a histochemical and ultrastructural study.

Rounded or polyhedral, acellular, dense lamellated structures were seen within the cystic and glandular spaces in a case of low-grade papillary adenocarcinoma of the parotid gland. These structures displayed the histochemical characteristics of amyloid, namely, pink color with apple-green birefringence and bright red fluorescence with alkaline congo red, orthochromasia and red birefringence with standardized toluidine blue, positive dimethylaminobenzaldehyde nitrite and diazotization coupling reactions, and spontaneous autofluorescence. At the ultrastructural level the tumor consisted of cuboid, flattened, or elongated epithelial cells with varying degrees of differentiation, but most mature tumor cells had numerous intracellular intermediate filaments. These filaments were randomly oriented and had no lateral fasciation; they were 10 nm wide and similar to those constituting the intraluminal corpora amylacea. These bodies displayed increased fibrillary density. Cellular organelles and pyknotic nuclei were frequently present at the periphery of the fibrillary masses. Amyloid masses, histochemically and ultrastructurally indistinguishable from those in the lumens, were present in the stroma as well. It is postulated that both stromal and intraluminal beta-fibrillary bodies result from apoptosis and desquamation of neoplastic cells, with progressive release and confluency of intracellular intermediate filaments within closed cystic spaces. This additional evidence of beta-fibrillosis associated with a slow-growing non-hormone-secreting salivary gland tumor suggests that these tumors may be associated with amyloidosis more frequently than was previously suspected.

Adenocarcinoma, Papillary↗

Tannic acid-glutaraldehyde fixative and pleomorphic adenomas of the salivary gland: an ultrastructural study.

Four cases of pleomorphic adenomas of parotid glands were fixed by immersion in a mixture of 4% tannic acid and 3% glutaraldehyde followed by OsO4 postfixation and heavy metals staining. This clearly visualized the presence of dense amorphous elastic fibers in cellular and myxochondroid areas. The dense amorphous fibers were associated with varying numbers of peripheral filaments which appeared sometimes as bundles of parallel fibrils without intermingled amorphous material. These intermediate-sized filaments were seen indirect continuity with similar intracellular filaments with or without interposition of basal-membrane-like material and/or with extracellular filament-containing vesicles. It is suggested that these filaments are synthesized intracellularly and released into the extracellular space by neoplastic myoepithelial cells mainly by cytoplasmic vesicle separation. In addition, small round vesicles with a dense core of amorphous material and staining characteristics identical to those of extracellular elastin were frequently seen in the peripheral parts of these myoepithelial-like cells. It is possible that these dense-cored vesicles have a secretory function and contain a precursor of elastin.

Adenoma, Pleomorphic↗

Treatment of acquired aphasia: speech therapists and volunteers compared.

This paper reports on a multicentre trial comparing the effects of speech therapists and untrained volunteers on recovery from aphasia following stroke. One hundred and fifty-five patients entered the study and 96 completed it. Patients in both treatment groups improved, and there were no differences overall in the amount of progress made. A small subgroup of patients who started treatment much later had equivalent initial scores and made almost as much progress as those who started earlier. It is suggested that the improvement in communication which occurred during treatment may be due both to the appropriate stimulation which was based on detailed and accurate speech therapy assessment, and to the regular support and encouragement provided within the therapeutic relationship.

Aged↗

Study of granulocyte-macrophage progenitor (CFUc) preservation after slow freezing of bone marrow in the gas phase of liquid nitrogen.

Storage of human hematopoietic stem cells has been made possible through effective preservation of viability by freezing technique. We have studied the quantitative and qualitative aspects of granulocyte-macrophage precursor (CFUc) recovery from 29 bags of frozen bone marrow stored at - 160 degree C in the gas phase of liquid nitrogen for several months or years. it has been shown that with the freezing and preservation technique used, over 75% of the proliferative capacity of the cryopreserved CFUc was recovered. The influence of various factors on the quality of bone marrow preservation was studied and showed that dimethylsulfoxide (DMSO) appeared to cause substantial loss of CFUc at 4 degree C. Evaluation of CFUc in vitro is essential for determining the quality and richness of cryopreserved bone marrow with a view to using such marrow for autologous grafting intensive chemotherapy or total body irradiation in patients with hematological malignancies or solid tumors. No correlation was found between the number of nucleated bone marrow cells and CFUc content.

Adolescent↗

[Diagnosis and treatment of lacrimal pathway lesions].

The experience of a clinic dealing exclusively with lacrimal system problems is reported. 2,002 patients (2,497 eyes) were treated over the course of eight years. The great majority of patients were children under the age of 4 years. the etiology of the lacrimal dysfunction varied according to age. In infants and children under four 98% of the cases were of congenital defects. The most frequent causes in adolescents and adults was trauma, and in the elderly, inflammation. Inflammation of the lacrimal sac was more than twice as common in females, and the right side was more often affected that the left (4:3).

Adolescent↗

"Hyaline cells" in pleomorphic adenoma of salivary gland origin.

Fifty-two cases of pleomorphic adenoma of minor salivary gland origin and seventy-two cases of pleomorphic adenoma of major salivary gland origin were examined for the presence of hyaline cells (plasmacytoid cells). Hyaline cells were found in 38 percent of the minor salivary gland cases and 21 percent of the major salivary gland cases. When stained with hematoxylin and eosin, the hyaline cells exhibited an eccentric nucleus and a striking homogenous, ground-glass, eosinophilic cytoplasm. At the ultrastructural level, the cytoplasm of the hyaline cells was closely packed with intermediate-sized filaments having no apparent orientation. It is suggested that the hyaline cells are modified myoepithelial cells.

Adenoma, Pleomorphic↗