Biomedical subjects
Publications and source records attributed to H Jensen.
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The pharmacokinetics of amikacin were examined in six bilaterally nephrectomized patients undergoing hemodialysis and in four patients with a minimal residual renal function undergoing peritoneal dialysis. The mean elimination half-life before the dialysis was 86.5 h in the anephric patients and 44.3 h in the patients with minimal residual kidney function. The results from the anephric patients suggest that some extrarenal elimination of amikacin may occur. The mean volume of distribution was about 25% of the total body weight. This is in accordance with values reported from subjects with normal renal function. During hemodialysis the half-life decreased to less than 10% (5.6 h) of the pretreatment value. The effectiveness of peritoneal dialysis was less as the half-life decreased to only about 30% (17.9 h) of the pretreatment value. During the dialyses a significant correlation between the half-life of amikacin and the decrease in blood urea and serum creatinine was demonstrated. The pharmacokinetic data were used to make dosage regimen recommendations for the treatment of patients undergoing intermittent hemodialysis or peritoneal dialysis.
The ultrastructure of the nuclear envelope was studied in cardiac muscle cells of 12 patients undergoing cardiopulmonary bypass surgery. Two main types of membrane inclusions, globular and tubular, were observed in the nuclei. The globular type was found in 6 patients. The globular inclusions were about 0-5mu to 1-5mu in diameter and lined by two unit membranes equal in structure to that of the nuclear envelope. The lining was probably always in continuity with the nuclear membranes. Such inclusions contained a granular matrix in which no cytoplasmic organelles could be seen, with the exception of a limited number of ribosomes. The tubular type of nuclear inclusion was observed in the cardiac tissue of 3 patients. These tubules ran in straight or slightly bent segments of about 0-2 mu to 1-6 mu length, interrupted by bendings at obtuse or right angles. The diameter of their lumina measured about 300 A to 800 A. Such tubules were nearly always found in areas of the nucleoplasm rich in heterochromatin. Nuclear pore-like structures were occasionally found in the tubular wall. The tubular wall consisted of a single unit membrane shown to be in continuity with the inner membrane of the nuclear envelope. Since these nuclear aberrances have been observed at all of the stages examined, the possibility is considered that they may represent a specific nuclear response to the process of cardiac hypertrophy.
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The ultrastructure of myocardial cell nuclei was examined in a group of 12 patients undergoing cardiopulmonary bypass surgery. In one patient (aged 60 years) with rheumatic heart disease, myocardial cells were observed which contained mitochondria with well preserved membranes within their nuclei. Such intranuclear mitochondria were observed with equal frequency in all of the three stages examined, i.e. at the start and end of aortic crossclamping and after 20 min of reperfusion. Approximately 2-3% of the total number of nuclei studied in this patient contained mitochondria. A partial disintegration of the membranes of the affected nuclei was sometimes seen. These findings are discussed in relation to the hypothesis of a de novo synthesis of mitochondria inside the nucleus, and also, in relation to the "trapping theory" of mitochondria through the nuclear envelope.
The aorta of Sympetrum danae possesses two dorsal diverticula: one in the mesothorax and one in the metathorax. They are very similar in form and position. Each diverticulum has a dorsal valve through which blood is pumped from the wings down into the aorta. The wall of the aortic diverticula consists of two simple cell layers: an outer epidermis-like layer and an inner muscle layer. The nuclei of the muscle cells are situated close to the lumen of the diverticula. The mitochondria are evenly dispersed between the myofibrils and are often paired up on either side of the Z-band. The Z-bands are thick and fragmented. The length of the sarcomeres varies from 3.3 to 6.1 mu. The A-band length is about 3 mu. The myofibrils consist of thick (250 A) and thin (85 A) filaments. Each thick filament is surrounded by 9-12 thin filaments. The sarcoplasmic reticulum is well developed and separates the myofibrils with one or two layers. The T-tubules are flattened and branch irregularly like a two-dimensional tree between the lamellar myofibrils. Intercalated discs are observed. The peculiarities of the muscle of aortic diverticula in S. danae are discussed in relation to various muscles of other insects and arthropods.
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Using an automated immunoprecipitin reaction, the urinary excretion of albumin, transferrin, haptoglobin, IgM, IgG, IgA, free lambda and kappa light chains from immunoglobulin, lysozyme and beta2-microglobulin has been investigated in 40 long-term bilaterally nephrectomized renal transplant patients. The excretion of the proteins, except lysozyme, was significantly increased in 21 of the paitents with Albustix-negative urine. In patients with glomerulonephritis prior to the transplantation, the excretion of albumin, transferrin, and IgG was significantly increased compared with the other patients. The IgM excretion was significantly increased in patients who had received C and D matches compared with those with A and B matches. Patients with severe surgical complications in the postoperative period had a tubular proteinuria, and in patients surviving more than 60 months after transplantation the excretion of several proteins was significantly increased compared with patients surviving less than 60 months.
Three adolescents with uraemic osteodystrophy were treated for 7 months with daily oral doses of 1alpha-hydroxycholecalciferol (0.25-10.0 mug). All the patients were hypocalcaemic and had high serum levels of alkaline phosphatase before the treatment. A rapid rise in serum calcium and a slow, but pronounced decline in serum alkaline phosphatase concentration were observed during the period of treatment. 1alpha-Hydroxycholecalciferol induced hypercalcaemia in two situations. In both cases the hypercalcaemia was transient, serum calcium being normalized in a few days by withdrawal of the drug. Withdrawal of the drug also in other situations resulted in a fall in serum calcium concentration in a couple of days. This suggests that 1alpha-hydroxycholecalciferol should be given daily or every other day. The response did not subside during 7 months of treatment. On the contrary, the maintenance dose necessary to keep serum calcium constant was smaller than the initial dose necessary to normalize serum calcium. Bone mineral content, estimated by photon absorptiometry, rose. The rachitic bone lesions seen radiologically were significantly ameliorated during the treatment.
The relative clearances of albumin, transferrin, haptoglobin, IgG, IgA, and IgM and the relative excretion of immunoglobin free lambda- and kappa light chains, lysozyme, and beta2-microglobulin were measured in 24 patients who had recently received renal transplants. Eleven out of 13 acute rejection episodes were predicted 1 to 5 days before the clinical diagnosis was made, and in 2 patients the clinical diagnosis of rejection and the prediction were made simultaneously. Successful antirejection therapy was followed by a decrease in protein excretion; in irreversible rejection episodes protein excretion continued to increase in spite of antirejection therapy. It is recommended that the relative clearances of IgG and haptoglobin be measured daily in patients recently treated by renal transplantation.
The influence of the duration of warm and cold ischemia on initial graft function on patient survival, graft survival, and graft function one year after transplantation was assessed in 234 consecutive cadaveric renal transplants. The number of grafts with delayed function was found to increase with increasing duration of the warm and cold ischemia times. On the other hand, the duration of the ischemia times and consequently the initial function, whether immediate or delayed, did not influence the survival of graft and patient nor the function of the graft one year after transplantation.
Three adolescents on regular haemodialysis were treated for more than one year with 1alphaOHD3 in doses of 0.25 - 10 mug/day orally. All the patients had hypocalcaemia, a high serum level of alkaline phosphatase and signs of uraemic osteodystrophy on X-ray. Clinical signs of bone disorder were present in two cases. During the treatment serum calcium and alkaline phosphatase normalised, and there was a marked improvement in the X-ray changes. Clinical improvement also took palce but not to the same extent as indicated by the laboratory data. It seems therefore important that treatment should start before severe bone lesions are present. Careful control of the treatment is necessary to avoid hypercalcaemia.
The membrane systems of the cardiac muscle cell of the isopod Cirolana borealis Lilljeborg are described. The sarcolemma invaginates at the level of the Z band, forming transverse tubules. Narrow tubules branch off in a longitudinal direction from these transverse and radially arranged Tz-tubules forming a transverse collar at each A-I level, where dyadic and triadic junctions are formed with the sarcoplasmic reticulum. Two different orientations of the coupling discs have been detected in the supercontracted sarcomere, and this observation has been discussed. Adjacent myofibrils are separated by a double layer of sarcoplasmic reticulum.
Two different muscle types are found in the body of Siboglinum fiordicum: body wall muscle and blood vessel muscle. Both are of a myomesothelial type. The myofibrils of the body wall muscle are non-striated and consist of thick and thin myofilaments. Scattered dense bodies and attachment plaques are described. The sarcoplasmic reticulum forms a three-dimensional network in the myofibrils and only peripheral couplings are observed. The thick filaments are of a paramyosin type and have a diameter ranging from 400-1500 A. The blood vessels muscle is non-striated, but sometimes a sarcomere-like organization has been observed. Both thick and thin filaments are present. The thick filaments have a diameter of 250-400 A and lack transverse striations. Dense bodies and attachment of plaques are few. The sparse sarcoplasmic reticulum is restricted to the myofibril periphery where it makes peripheral couplings with sarcolemma. The luminal surface of the vessels is lined by a basal lamina with collagen-like inclusions. No endothelium is found. The body wall muscle and the blood vessel muscle are compared with other muscle types described in invertebrates.
The dorsal hemal vessel in Parastichopus consists of three distinct layers: An outer flagellated epithelium, an intermediate circular muscle layer and an inner connective tissue layer which nearly fills the lumen. Between the outer and intermediate layer runs strands of nerve fibers. Each coelomic epithelial cell has one flagellum and some microvilli. It contains a number of different vacuoles and a few bundles of tonofilaments. One special type of vacuole which contains well organized myofilaments is described. Each muscle cell contains one myofibril of a non-striated type consisting of thick and thin filaments and no dense bodies. The sarcoplasmic reticulum is poorly developed, but peripheral coupling are frequently found. The muscle cells in the dorsal hemal vessel of Parastichopus are compared with other muscles in echinoderms and muscle types described in other phyla.
A 55-year old man with lithium intoxication showed increasing serum concentrations in spite of forced diuresis and dialysis. A high lithium content was found in gastric juice three days after the compound had been taken. The serum lithium level began to fall after gastric lavage.
Four patients with benign monoclonal immunoglobulinaemia and associated glomerulopathy are described. Immunohistochemical investigations of the immunoglobulin-containing cells in the bone marrow revealed an unexpectedly pronounced predominance of monoclonal over polyclonal cells as typically seen in macroglobulinaemia and multiple myeloma, but in contrast to the malignant plasma cell proliferations the percentage of immunoglobulin-containing cells only constitued 6-12% of the nucleated cells. The possible pathogenetic mechanisms relating monoclonal immunoglobulinaemia and glomerulopathy are unknown. The sera did not contain antibodies to glomerular basement membrane, cryoglobulins, antinuclear factors or antiglobulins. The immunohistochemical technique certainly offers a clear advantage over conventional bone marrow cytology in the study of patients with monoclonal immunoglobulinaemia.