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Biomedical subjects

P L Nielsen

Publications and source records attributed to P L Nielsen.

At least 19 recordsLinked to original sources
PubMed2005

The hypomagnesic rat model: dermatitis-prone hairless rats with mild magnesium depletion fed a diet low in lipids did not develop pruritic dermatitis.

BACKGROUND/PURPOSE: In the hypomagnesic dermatosis of rats, low-dietary magnesium leads to lowered serum Mg2+, universal dermatitis and scratching. The model is postulated to work better if the diet also has a low content of lipids. Pruritus is seen in patients suffering from anorexia nervosa and resolves on weight restoration. Lipid depletion of the diet and/or lowered body weight may therefore be important in developing pruritus. The purpose of the present study was to investigate whether a diet low in lipids can induce pruritus in dermatitis prone rats because of mild magnesium depletion thereby focusing on the role of lipids in the hypomagnesic dermatosis rat model. METHODS: Fourteen male hairless rats, 3 weeks of age, were fed a diet deficient in lipids and with a lower content of magnesium for a 4-week period and compared with 11 controls fed a normal diet. The skin was inspected daily and transepidermal water loss (TEWL), serum Mg2+ and scratching activity were measured. At the end, skin biopsies were taken from the flank and ears. RESULTS: Serum Mg2+ was significantly lowered in the diet group (P<0.001) but the rats developed no dermatitis or increased TEWL compared with 11 rats in a control group. Biopsies were normal with no sign of inflammation. Rats in the diet group had inferior weight gain, were less active and spent more time asleep than control rats (P<0.01). Furthermore, scratching activity monitored in the last week of the study as the number of scratch-sequences per awake minute was reduced in the diet group (P<0.001). CONCLUSION: The lipid-deficient diet was not able to induce pruritic dermatitis despite the fact that the rats were dermatitis prone because of mild magnesium depletion. It is not confirmed that dietary lipid depletion plays any significant role in the hypomagnesic dermatitis rat model. The dermatitis and the model appear to be strictly dependent on efficient magnesium depletion manufactured with very low magnesium levels.

Animals↗
PubMed2001

[Parasitic gallbladder infection].

In two cases of cholecystectomy for gall bladder calculi, the histological diagnoses were inflammation, fibrosis, and numerous calcified parasite eggs in the wall of the gall bladder, compatible with eggs from the liver fluke, which can infect humans who eat raw or undercooked fresh water fish (sushi!).

Adult↗
PubMed2001

An evaluation of the accuracy of shallow water matched field inversion results.

In this article the accuracy of geo-acoustic and geometric parameter estimates obtained through matched field inversion (MFI) was assessed. Multi-frequency MFI was applied to multi-tone data (200-600 Hz) received at a 2-km source/receiver range. The acoustic source was fixed and the signals were received at a vertical array. Simultaneously with the acoustic transmissions, a CTD (conductivity, temperature and depth)-chain was towed along the acoustic track. A genetic algorithm was used for the global optimization, whereas a normal mode model was applied for the forward acoustic calculations. Acoustic data received at consecutive times were inverted and the stability of the inverted parameters was determined. Also, the parameter estimates were compared with independent measurements, such as multi-channel seismic surveys (for geo-acoustic parameters). The obtained uncertainty in the inversion results was assumed to have two distinct origins. The first origin is the inversion method itself, since each optimization will come up with some solution close to the exact optimum. Parameter coupling and the fact that some parameters hardly influence the acoustic propagation further contribute to this uncertainty. The second is due to oceanographic variability. Both contributions were evaluated through simulation. The contribution of oceanographic variability was evaluated through synthetic inversions that account for the actual sound speed variations as measured by the towed CTD-chain.

Journal Article↗
PubMed1997

[Traumatic tricuspid valve insufficiency].

We report a case of tricuspid insufficiency in connection with blunt chest trauma. The patient was involved in a car accident. The central venous catheter showed a right ventricular pressure curve, suggestive of a tricuspid valve insufficiency. A transoesophageal echocardiographic examination supported this by revealing a papillary muscle rupture. This kind of injury has been seen more frequently during the last 35 years, partly because of better diagnostic procedures and a better understanding of the pathology. The decelerating force in the right ventricular chamber produces a regurgitation thereby initiating rupture of the papillary muscle and/or the chordae tendinae. In a literature study twelve out of thirteen patients were involved in car accidents. Some of them had a dominant V-wave in the venous pulse curve, but no clinical observation is directly diagnostic. Therefore, cardiac lesions should be kept in mind whenever there is a history of blunt chest trauma. The best diagnostic approach is echocardiography.

Accidents, Traffic↗
PubMed1996

Soft tissue gliomatosis. Morphologic unity and histogenetic diversity.

Normal-appearing tissues in non-native sites constitute one of the more common morphologic expressions of abnormal development. The presence of pancreas in the wall or on the serosa of the small intestine and adrenal cortical tissue in a hernia sac are two familiar examples of heterotopias. We report our experience of mature glial tissues in the soft tissues of six children who were between the ages of 4.5 months and 2 years when they presented with a solitary mass on the chest wall (three cases), scalp (two cases) and gluteal region (one case). These tumors were all characterized by pale-staining fibrillary foci of mature neuroglia, which were intensely immunoreactive for glial fibrillary acidic protein in each case. One of the two scalp lesions was accompanied by a nodule of cartilage and a meshwork of pseudovascular spaces, which were decorated with antibodies to vimentin and epithelial membrane antigen consistent with meningothelial tissue. The histogenesis of the neuroglial tissue in the gluteal region and scalp was, respectively, on the basis of a recurrence of a sacrococcygeal teratoma in the former case and sequestered encephaloceles in the last two cases. A facile explanation for the occurrence of neuroglial tissue in the soft tissue of the chest wall in the remaining three cases was less than obvious as none of the patients had accompanying neurologic or anatomic defects and all were in a nonmidline location. These three cases of soft tissue gliomatosis of the chest wall are similar to an earlier example in the recent literature whose histogenesis was as enigmatic as it proved to be in our three cases. Although the histologic and immunohistochemical features of these six cases were very similar in each instance, their origin varied from a recurrent sacrococcygeal teratoma and sequestered encephaloceles to essentially unknown.

Antigens, Neoplasm↗
PubMed1996

Staphylococcal enterotoxin B applied on intact normal and intact atopic skin induces dermatitis.

BACKGROUND AND DESIGN: Colonization of inflammatory skin diseases with Staphylococcus aureus is a frequent phenomenon and may cause exacerbation of the skin disease. Staphylococcus aureus strains present on atopic dermatitis are capable of releasing staphylococcal enterotoxins, a group of superantigens that are very potent T-cell activators. To determine whether the superantigen staphylococcal enterotoxin B can induce inflammation when applied on the skin, staphylococcal enterotoxin B was applied with and without occlusion on the volar aspect of the skin on the forearm of 10 subjects without skin disease and six subjects with atopic dermatitis of minimal activity and no eczema on the volar aspect of the skin on their forearm. The main outcome measures were clinical rating; determination of the increase of the thickness of the skin-fold; and determination of skin blood flow. RESULTS: Clinically, staphylococcal enterotoxin B induced skin changes of erythema and induration in 10 of 10 healthy volunteer subjects and six of six subjects suffering from atopic dermatitis, while the vehicle induced clinically evident skin changes in only one of 10 healthy subjects and none of six subjects with atopic dermatitis. On day 3 after the application of an occluded patch containing 10 micrograms/cm2 of staphylococcal enterotoxin B in the healthy subjects, the thickness of the skinfold increased 0.47 +/- 0.49 mm (mean +/- SD) (n = 9; P < .02) relative to the increase in the thickness of the skinfold following application of the vehicle. The Doppler laser-measured skin blood flow index had increased from 1.0 +/- 0.4 to 5.3 +/- 3.7 (mean +/- SD) (n = 10; P < .002). On day 3 after the application of occluded patchs containing 10 micrograms/cm2 of staphylococcal enterotoxin B in the subjects suffering from atopic dermatitis, the increase in the thickness of the skinfold increased 0.20 +/- 0.24 mm (n = 6; P, not significant) relative to the increased thickness in the skinfold following application of the vehicle. The Doppler laser-measured skin blood flow index had increased from 1.1 +/- 0.4 to 3.7 +/- 2.2 (n = 6, P, not significant). Three of six subjects suffering from atopic dermatitis experienced a flare of their disease in the elbow flexure ipsilaterally to where the staphylococcal enterotoxin B patch was applied. CONCLUSIONS: The superantigen staphylococcal enterotoxin B applied on intact skin from both normal subjects and patients with atopic dermatitis induces an inflammatory reaction. This finding suggests that superantigens released from S aureus present on the skin in inflammatory skin diseases may exacerbate and sustain the inflammation.

Adult↗
PubMed1993

The role of the internal thoracic artery in the sternal blood supply.

The altered arterial supply to the sternum after use of the internal thoracic artery in coronary bypass surgery was studied by delineation of the sternal arterial system with plastic material and by injection of ink/barium contrast for radiography and microscopy. The study was performed on 17 anterior chest walls from human cadavers. The total arterial supply was charted before and after 'harvest' of the internal thoracic artery. The dominant blood supply to the sternum was found to be periosteal and derived almost exclusively from branches of the internal thoracic artery. Following harvest of that artery, the arterial supply to the upper part of the corpus sterni was compromised, and based only on sparse ramifications to the periosteal membrane from the thoracoacromial artery via branches from the pectoralis major muscle.

Aged↗
PubMed1991

[Mastocytosis].

Mastocytoses are diseases caused by proliferating mast cells infiltrating one or more organs. The spectrum of mastocytosis includes the cutaneous forms urticaria pigmentosa and solitary mastocytoma (about 90% of mastocytoses) and systemic forms affecting other organs. Infiltrates are most often found in the bone marrow, spleen, lymph nodes and liver, but any organ may be affected. Patients with systemic mastocytosis may or may not have urticaria pigmentosa. About 35% of patients without urticaria pigmentosa have an associated malignant haematological disease and a poor prognosis. Symptoms caused by mast cell mediator release are best treated with antihistamines, but several other drugs may be used if the response is unsatisfactory. Many antineoplastic drugs have been tried to combat aggressive mastocytoses and mast cell leukaemia, but the results have been disappointing.

Adult↗
PubMed1991

[Epitheloid sarcoma--an overlooked diagnosis?].

Epitheloid sarcoma (ES) is a malignant soft-tissue tumour which occurs particularly on the hand and forearm in young adults. The tumour grows slowly and metastasizes relatively late but has, nevertheless, a considerable mortality and morbidity because it is frequently erroneously diagnosed, both clinically and pathologically, either as a benign tumour or as a reactive inflammatory process. Two typical cases with diagnostic delays of 12 and 15 years, respectively, which required amputations through the upper arm or forearm are described. Even although ES is a rare tumour form, clinicians and pathologists should be aware of this possibility as, in the early stages, the tumour can frequently be treated effectively and radically by wide local excision without amputation.

Adult↗
PubMed1991

Inverted papilloma of the nasal cavity: pathological aspects in a follow-up study.

The initially removed tumors from 42 patients with inverted papillomas of the nasal cavity and paranasal sinuses were subjected to an extensive histopathological examination in order to define the characteristics associated with multiple recurrences and development of malignancy. Two of the patients subsequently developed squamous cell carcinoma and eight patients had more than one recurrence. No specific histological characteristic was determined to be a predictor of multiple recurrences or development of malignancy. However, three patterns of characteristics emerged from the data which were found to be related to the development of malignancy, multiple recurrences, and benign behaviour. Malignancy was found to be associated with bilateral inverted papilloma, a predominance of mature squamous epithelium, the presence of all three epithelial types (metaplastic squamous, mature squamous, and cylindrical), severe hyperkeratosis, a mitotic index greater than or equal to 2 per high-power field (HPF), absence of inflammatory polyps among the papillomas, an abundance of plasma cells, and an absence of neutrophils. Multiple recurrences (without malignancy) were associated with a mitotic index greater than or equal to 2 per HPF and an absence of inflammatory polyps. Benign behaviour was associated with predominantly mucinous tumors, a mitotic index less than 1 per HPF, a ratio of neoplastic epithelium/connective tissue stroma greater than or equal to 6, and the presence of inflammatory polyps among the papillomas.

Carcinoma, Squamous Cell↗
PubMed1990

[Inverted papilloma of the nose and nasal sinuses. Incidence, long-term course, therapeutic results].

Inverted papilloma is an unusual tumour in the nose and nasal sinuses with a marked tendency to recurrence following surgical treatment and with a greatly increased risk for synchronous or metachronous development of carcinoma. A retrospective investigation comprising 42 patients with histological revision revealed an incidence of 0.6/100,000 per annum. Two patients had also carcinomata. No significant differences were observed between the recurrence rates following simple excision, excision via the maxillary sinus or via lateral rhinotomy. Follow-up control for ten years is recommended.

Adult↗
PubMed1989

[A review of pulmonary histiocytosis X].

The article contains a review and two case reports of pulmonary histiocytosis-X. This is a rare disease entity comprising about 3% of all chronic interstitial lung diseases. Diagnosis is confirmed by histological and electronmicroscopic demonstration of the typical histiocytosis-X cell. The course of the disease varies. About 25% of the patients show spontaneous remission, in 40% the changes remain stationary, while 35% progress and eventually die from respiratory insufficiency or cor pulmonale. Treatment with glucocorticoids and cytostatics should be initiated at high disease activity, with progressive X-ray changes and decreasing pulmonary function.

Adult↗
PubMed1989

Two malignant melanomas in skin and tonsil during consecutive pregnancies.

A patient is described with two primary malignant melanomas which developed during consecutive pregnancies four years apart. The first melanoma was of the cutaneous nodular type located on the arm. The second, of the superficial spreading type, was located in the oral mucosa near the right tonsil. The influence of pregnancy on the development and outcome of malignant melanomas is discussed, and the risk of a subsequent pregnancy is emphasised.

Adult↗
PubMed1987

A distinct subtype of idiopathic myelofibrosis with bone marrow features mimicking hairy cell leukemia: evidence of an autoimmune pathogenesis.

A young female patient presented with severe anemia and myelofibrosis. The spleen was not enlarged on clinical examination and no leukoerythroblastosis or tear-drop poikilocytosis was found. A bone marrow biopsy disclosed severe myelofibrosis and many megakaryocytes, which appeared morphologically normal. A striking feature was a heavy spongy infiltration by large lymphocytic cells, which were tartrate-resistant acid phosphatase negative and without hairy projections. This bone marrow appearance highly resembled the clear cell appearance of the hairy cell infiltrate in hairy cell leukemia. A diagnosis of acute autoimmune myelofibrosis was made. During high-dose glucocorticoid therapy the bone marrow fibrosis completely resolved and there was an improvement of peripheral blood values. The disorder is supposed to feature a distinct clinicopathological entity within the syndrome of idiopathic myelofibrosis. The disease should be considered in the differential diagnosis of patients with myelofibrosing disorders, including acute myelofibrosis and hairy cell leukemia.

Adult↗
PubMed1987

Intrinsic and extrinsic microbial contamination of home total parenteral nutrition manufactured in eva-infusion bags (the i.v. bag).

Microbial contamination of total parenteral nutrition including fat emulsions in 1-3 litres plastic infusion bags (the i.v. bag) was studied during production in the pharmacy and administration both at home and in the hospital. Production contamination was investigated by dispensing test bags containing growth medium mixed with dextrose-salt solution. In this highly sensitive system, contamination was detected in less than 4% of cases. In-use contamination was estimated at the end of the infusion. The average contamination rate (+/- growth) in the five patients studied was 6.7% accompanied by considerable variation. Identification of the contaminants revealed that 85% of the contaminated bags contained staphylococci, indicating skin contamination. An investigation on the effect of the procedure used for attaching the infusion set on the contamination rate, was carried out with bags that contained sterile growth medium. This showed no contamination in 14 cases indicating the catheter as the most plausible source of contamination. It is concluded that both production in the community pharmacy and administration in the home are not associated with a higher microbial contamination than in central hospitals. It is, however, recommended that the microbial quality of the production process and the administration procedure are regularly monitored.

Adolescent↗