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Biomedical subjects

K Nielsen

Publications and source records attributed to K Nielsen.

At least 343 records · Page 19Linked to original sources
PubMed1967

Metabolism of bovine immunoglobulin. II. Metabolism of bovine IgG in cattle with secondary hypoimmunoglobulinemia.

The turnover of I(131)-labelled IgG has been studied in cattle with mild hypoimmunoglobulinemia secondary to gastrointestinal disorders. A gastrointestinal loss of immunoglobulin was the most likely cause of the hypoimmunoglobulinemic condition. Thus, 6 animals with severe digestive symptoms (diarrhoea) had increased turnover rates of I(131)-IgG, whereas animals that had recovered from diarrhoeal diseases had normal or even low turnover rates (table I). It is concluded that the pattern of immunoglobulin metabolism is closely related to the clinical picture of the digestive disease.

Agammaglobulinemia↗
PubMed1966

Metabolism of bovine immunoglobulin. I. Metabolism of bovine IgG in cattle with chronic pyogenic infections.

Isolation of IgG-slow by anion exchange chromatography is described. The turnover of IgG-I(131) has been studied in 10 cows, 5 of which were hyperimmunoglobulinemic, i. e. with serum immunoglobulin levels above 3.0gm/100 ml. These hyperimmunoglobulinemias were caused mainly by pyogenic infections. When these cows were compared with 5 normoimmunoglobulinemic cows the salient turnover data were, high fractional turnover rates, short plasma half lives, low Ev:Iv ratios and extended plasma volumes (table I). The results are discussed in relation to similar findings in other animal species and man. Possible mechanisms of the observed hypercatabolism are outlined.

Animals↗
PubMed1965

An experimental obliterating thromboangiitis limited to the posterior part of the body.

After a brief outline of the principles involved in the production of thrombohemorrhagic phenomena (THP) with special organotropic localizations, an experimental technique is described which permits the production of acrocyanosis and thrombohemorrhagic lesions largely limited to the posterior part of the body. This phenomenon can be consistently produced by certain combinations of THP elicitors, anaphylactoid agents and noradrenaline (NA). The most effective combination among those tested is thorium dextrin (Th-Din) plus tannic acid plus NA. Several drugs can decisively influence the course of this reaction. Most otable among these are Neo-Antergan (an antihistaminic) which sensitizes for the production of the aboral THP, while heparin (presumably through its anticoagulant effect) and Dibenamine (presumably through its antiadrenergic action) offer virtually complete protection. When only Th-Din plus tannic acid is given, there develops an intense but reversible cyanosis in the hind paws and tail; additional treatment with NA induces obliterating thromboangiitis with hemorrhages and gangrene. None of hese changes are produced by Th-Din, tannic acid or NA alone. Evidently, here, e are dealing with pluricausal experimental diseases whose possible relationship to Raynaud's disease, thromboangiitis obliterans and anaphylactoid purpura is briefly discussed.

Animals↗
PubMedDate not supplied

The effects of aging on the frequency of nerve fibers in rhesus monkey striate cortex.

In the rhesus monkey primary visual cortex, there are bundles of vertically oriented myelinated axons, which mainly contain efferent fibers originating from pyramidal cells. At the level of layer 4Cbeta, the bundles are regularly arranged and the nerve fibers in them are closely packed. In order to determine if a significant loss of intracortical nerve fibers occurs as the primate cerebral cortex ages, the frequency of vertically oriented myelinated fibers was examined at the level of layer 4Cbeta in 1 microm-thick, tangential sections. The results show no statistically significant differences in the numbers of vertically oriented fibers beneath 1 mm(2) of cortical surface between young, middle-aged, and old monkeys, and electron microscopic examination reveals few signs of degenerating axons. There is, however, an age-related breakdown of the myelin in sheaths that surround some axons. Thus, the data indicate that there is not a loss of vertically oriented myelinated fibers from the cortical gray matter during aging, although their sheaths may be altered.

Aging↗
PubMedDate not supplied

Extracorporeal membrane oxygenation after lung or heart-lung transplantation.

Extracorporeal membrane oxygenation (ECMO) has proven to be life-saving in cases of reversible lung injury. One potential application of ECMO in the field of lung transplantation is the support of the patient with acute pulmonary failure immediately after transplantation until the transplanted lung has resumed satisfactory gas transfer function. The authors have had experience with ECMO in three patients who have had acute pulmonary failure and inadequate oxygenation after bilateral single lung (BSLT) or heart-lung transplantation (HLT). Patient 1 is a 47-year-old woman with alpha-1 antitrypsin deficiency who underwent a HLT and experienced fulminant pulmonary edema secondary to an intraoperative coagulopathy that required massive transfusion. Patient 2 was a 45-year-old man with a patent ductus arteriosus (PDA) that resulted in Eisenmenger's complex. Patient 2 underwent an HLT and experienced acute pulmonary failure. Patient 3 is a 58-year-old woman with an atrial septal defect (ASD) and pulmonary hypertension who underwent repair of the ASD and BSLT. Patient 3 experienced complete atelectatic collapse of the right lung and pulmonary edema of the left lung. These three patients had PO2 measurements of 23, 39, and 23 mmHg, respectively, despite receiving 100% FiO2 and maximal ventilatory support. All three patients were subsequently placed on ECMO and had improvement of their oxygenation. Patients 1 and 3 were successfully weaned from ECMO and extubated on post-operative day (POD) 21 and 16, respectively. Patient 2 had significant improvement in oxygenation but died on POD 4 of persistent mediastinal hemorrhage.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Loss, Surgical↗