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Biomedical subjects

C Jensen

Publications and source records attributed to C Jensen.

At least 19 recordsLinked to original sources
PubMed1992

Does the shunt opening pressure influence the effect of shunt surgery in normal pressure hydrocephalus?

Thirteen patients with normal pressure hydrocephalus were operated upon with an externally maneuverable shunt system (Sophy SU8) in order to investigate its influence on clinical outcome, intracranial pressure and cranial CT parameters. The opening pressure was set at high at surgery and lowered stepwise at intervals of three months to medium and low. The clinical condition, intracranial pressure and cranial CT parameters were examined at the end of the 3 months interval on each pressure level. The patients improved within the first 3 months inspite of an unchanged mean intracranial pressure and remained in a stable clinical condition during the rest of the study period. The intracranial pressure was significantly reduced at 9 months. The ventricular index, Evans index, temporal horn and third ventricle width were reduced 3 months post-operatively and did not change significantly during the rest of the study. The pre-operative third ventricle width was correlated to high psychometric test results after shunt surgery. Reduction in ventricular index, Evans index and third ventricle width after surgery correlated to improvement in psychometric scoring. The clinical improvement after shunt surgery for normal pressure hydrocephalus is seen within 3 months and is independent of the adjusted valve pressure.

Aged↗
PubMed1992

Elbow flexion test in the normal population.

The elbow flexion test was investigated in 204 elbows in 102 normal volunteers. The effects of various wrist and shoulder positions were also studied. In 20 elbows in 15 persons (10%) flexion tests were positive with the wrist and shoulder in neutral position. In 27 elbows in 20 persons (13%) tests were positive with wrist extension and shoulder abduction.

Adolescent↗
PubMed1991

The effect of forced expirations on mucociliary clearance in patients with chronic bronchitis and in healthy subjects.

Animal studies have shown that frequent coughing may damage the mucociliary apparatus in flow-limiting segments of the central airways. To determine whether mucociliary clearance in humans is affected by repeated dynamic compression associated with forced expirations, we measured pulmonary deposition and mucociliary clearance for 2 h of inhaled [99Tcm]albumin. The subjects inhaled [99Tcm]albumin on 2 study days (randomized) using (A) slow inspirations and forced expirations, while inhalation using (B) forced inspirations and slow expirations served as control. The study was conducted using 10 patients with chronic hypersecretory/obstructive bronchitis and six normal subjects. We found that inhalation of [99Tcm]albumin by the two manoeuvres (A and B) resulted in similar patterns of aerosol deposition. There was no significant difference in retention of radioactivity in the central lung region at 1 h in the patients with chronic bronchitis after inhalation with manoeuvre A (102%) and with manoeuvre B (91.5%), or in the healthy subjects after manoeuvre A (74%) and manoeuvre B (77%). There was also no difference in the retention at 2 h or in overall mucociliary clearance in any of the groups. We conclude that dynamic compression in the central airways associated with forced expiration does not affect bronchial clearance in the airways of healthy subjects or in patients with chronic bronchitis.

Adolescent↗
PubMed1991

The effects of postural drainage and positive expiratory pressure physiotherapy on tracheobronchial clearance in cystic fibrosis.

We studied the effects of two chest physiotherapy regimens on whole lung and regional tracheobronchial clearance (TBC) in ten patients with cystic fibrosis. The regimens were given on two separate days and consisted of 20 min of (1) postural drainage and the forced expiration technique (PD + FET), and (2) positive expiratory pressure (PEP-mask) and FET (PEP + FET). A third day served as control. The study days were randomized. Each day, the clearance of lung radioactivity was measured for 3 h by gamma camera. The number of spontaneous coughs was recorded and the sputum expectorated was sampled. We found that both PD + FET and PEP + FET improved whole lung TBC at 30 minutes and 1 h four or fivefold (p less than 0.01) compared with control, whereas at 2 h and 3 h only the improvement following PEP + FET (approximately 1.4 times) was significant (p less than 0.05). There was no significant difference in whole lung or regional TBC between the PD + FET and PEP + FET treatments. The correlations between TBC and the radioactivity content in sputum expectorated (rs2 = 0.76) and between TBC and numbers of coughs (rs2 = 0.65) were better than between TBC and the weight of sputum expectorated (Rs = 0.39). We conclude that PD or PEP when combined with FET have similar effects on short-term whole lung and regional TBC in patients with cystic fibrosis. Evaluation of TBC during chest physiotherapy when only based on the weight of sputum expectorated seems inadequate.

Adolescent↗
PubMed1991

Intra-abdominal location of peritoneal catheters during CAPD.

Thirteen patients were studied on two random occasions in order to evaluate the relationship between 1) volume and rate of dialysis outflow and the subsequent inflow, 2) patient's impression of the location of the catheter tip, and 3) stability of the catheter tip location. Outflow with the catheter tip located in the middle part of the abdomen was significantly lower than with the tip located in the inferior quadrants (p less than 0.02). No catheter tips were located in the far upper regions of the abdomen. Only one patient was able to state the exact location identical to fluoroscopy. 92% of the fluoroscopic evaluations showed that catheter tips were located in the same anatomical region in the upright as well as in the supine position. If vertical "neighbour" anatomical regions were included in the evaluation of the catheter tip migrations, all catheter tips were located in the same or the vertical "neighbour" region at the two study periods.

Abdomen↗
PubMed1991

Peritoneal catheter tip location during non-complicated continuous ambulatory peritoneal dialysis.

In the present study, we evaluated the relationship between 1. the volume and rate of dialysis outflow and subsequent inflow, 2. the patient's impression of the location of the catheter tip and 3. the stability of the catheter tip location. Thirteen patients were studied on 2 random occasions (periods 1 and 2). Inflow (L/min) was significantly faster than outflow (p less than 0.05). No catheter tips were located in the far upper part of the abdomen. Outflow with the catheter tip located in the middle part of the abdomen was significantly lower than with the tip located in the inferior quadrants (p less than 0.02). Two patients were able to feel the catheter tip at Period 1, and 4 at Period 2, but only 1 patient was able to state the exact location identical to fluoroscopy. Ninety-two percent of the fluoroscopic evaluations showed catheter tips located in the same anatomical regions in upright as well as supine positions. If vertical "neighbour" anatomical regions were included in the evaluation of the catheter tip migrations, all catheter tips were located at the same or the vertical "neighbour" region in the 2 study periods.

Aged↗
PubMed1990

Developmental time and mortality of the reduviid bug Triatoma infestans with differential exposure to coprophagic infections with Blastocrithidia triatomae (Trypanosomatidae).

Developmental time and survival in larvae of the reduviid bug Triatoma infestans were studied in uninfected groups and in those exposed to a coprophagic infection with Blastocrithidia triatomae. Addition to young uninfected larvae of (a) different numbers of infected bugs, (b) infected and uninfected bugs, and (c) fresh or dry infectious feces were compared. Retardation of development was evident in groups given infected larvae or fresh feces. Mortality rates were correlated with infection rates and were higher in groups given more infected bugs, independent of the presence of uninfected bugs. Therefore, bugs did not discriminate between feces from infected and uninfected bugs, or they did not reject infectious feces. Dry feces had to be redissolved with fresh feces before infection was possible.

Animals↗
PubMed1990

The effect of Blastocrithidia triatomae (Trypanosomatidae) on the midgut of the reduviid bug Triatoma infestans.

The pathogenic flagellate Blastocrithidia triatomae disrupts the digestion of Triatoma infestans; the midgut ultrastructure of bugs infected with the flagellate and of uninfected bugs is compared. Third or fourth instar larvae were dissected either unfed or 1 week after feeding. In all uninfected bugs extracellular membrane layers (e.m.l.) covered the apical microvillar border of the epithelial cells. Some midgut regions of bugs infected with B. triatomae appeared normal but often adjacent cells showed pathological effects. In affected cells the e.m.l. and the microvilli and finally the cells themselves were reduced or destroyed. Correlated with these observations of pathogenicity the method of attachment of parasites changed. When the e.m.l. were present only rarely were flagella found, but on extracellular membrane-free cells B. triatomae attached by flagellar enlargement to the microvillar border or, if this was reduced, to the apical host cell membrane. No hemidesmosome-like plaques were found at the attachment site. Although some flagella were inserted into the apical region of the cells no intracellular flagellates were observed.

Animals↗
PubMed1990

Chest radiography in the intensive care unit. Indications for radiography and effects of selective archiving of films.

Consecutive chest radiographs (n = 2,303) in 601 patients in the intensive care units (ICU) were analyzed with regard to main disease and indication. Two thirds of the patients were transferred for routine post-operative treatment, 14 per cent mainly for cardiopulmonary insufficiency. The remainder were referred because of various clinical conditions. The main indications for chest radiography were routine radiographic follow-up and/or control of the position of catheters, tubes, drainages etc. (50%). Obvious clinical indications appeared in only about 1/4 of the patients. When the patients were discharged from the ICU all chest radiographs were analyzed with regard to their predicted future value. Films considered not worth storing were removed and stored in a separate archive (57%). During a 15-month follow-up period none of the removed films were requested, indicating that a substantial number of films can be sorted out continuously. The possibility to reduce and to 'clinically compress' the amount of data in a future digital picture archive is emphasized.

Humans↗
PubMed1989

[Klippel-Trenaunay-Weber syndrome. Magnetic resonance imaging diagnosis of medullary involvement].

The Klippel-Trenaunay-Weber (KTW) syndrome is a rare congenital syndrome of unknown etiology consisting of the triad: a large cutaneous naevus, congenital varicosities and hypertrophy of bones and soft tissues. A heterogenous group of vascular malformations may also occur. The case record of acute myelopathy in a patient aged 42 years with recognized KTW syndrome is presented. It is concluded that magnetic resonance imaging is indicated in cases of suspected intramedullary haemorrhage in patients with congenital vascular malformations.

Adult↗
PubMed1987

Effect of lysophosphatidylserine on immunological histamine release.

The effect of lysophosphatidylserine on immunological histamine release has been studied in rat peritoneal mast cells actively sensitized with horse serum and in human basophils challenged with anti-IgE. In contrast to other lysophospholipids, lysophosphatidylserine enhances the immunological histamine release in rat mast cells. The effect shows the kinetics of a saturable process with an apparent Km for lysophosphatidylserine of 0.26 microM. A similar Km value (0.21 microM) is found when measuring the non-immunological histamine release activated by lysophosphatidylserine plus nerve growth factor. A comparison with phosphatidylserine shows that a half-maximal response to lysophosphatidylserine occurs at a concentration 4-times lower. In addition, the magnitude of the response is higher. At variance with rat mast cells, lysophosphatidylserine does not influence the histamine release elicited by immunological and non-immunological stimuli in human basophils. The histamine secretion in these cells is instead affected by a calcium ionophore or tetradecanoylphorbolacetate, a compound producing activation of protein kinase C.

Animals↗
PubMed1987

Histamine release induced by bacteria. A new mechanism in asthma?

Bacteria release histamine from human basophil leukocytes and mast cells. The release can be caused by an immunological (IgE-dependent) mechanism, but mostly we found a non-immunological (lectin-mediated) mechanism which indicates that mediator release triggered by bacteria can occur without the person being sensitized to the micro-organism in question. Both bacteria and bacterial products such as endotoxins potentiate basophil histamine release caused by allergens in allergic patients or by bacteria in persons sensitized to the micro-organisms. It is therefore tempting to speculate that bacteria and their products might be of importance for asthma by their capacity to release histamine and to potentiate mediator release.

Asthma↗