PubMed Health⌕ Search

Biomedical subjects

J Christensen

Publications and source records attributed to J Christensen.

At least 19 recordsLinked to original sources
PubMed1992

How can a standard software package for data management in anesthesia be achieved?

Collecting data for administrative, statistical, medical, and organizational purposes is becoming increasingly important in anesthesia. In 1986 the Swiss Society for Anesthesiology decided to create a program that would be compatible for different computers and would expedite data collection. The system developed was called Information System for Operations (ISOP), which was written in the database and programming system Massachusetts General Hospital Utility Multi Programming System (MUMPS). It was installed in eight hospitals and met the initial requirements, but the individual requirements of the hospitals were greatly underestimated. MUMPS has an impressive data storage capability and handling when used in a personal computer (PC) network. The user-interface, however, is inferior to other PC packages, partly because windowing and mouse support were not implemented when the ANSI standard was set. Improved statistical programs, a module for on-line data acquisition, and intensive care unit (ICU) use will be additional modules to the program.

Anesthesia Department, Hospital↗
PubMed1992

Distributions of interstitial cells of Cajal in stomach and colon of cat, dog, ferret, opossum, rat, guinea pig and rabbit.

Electrical slow waves vary in prominence from one location to another in stomach and colon. If interstitial cells of Cajal are involved in generation of the slow waves, they might be more abundant in regions where slow waves are prominent than in regions where slow waves are small or absent. We calculated the density of distribution of interstitial cells of Cajal in colon and stomach of cat, dog, ferret, guinea pig, opossum, rabbit, and rat, using the zinc iodide-osmic acid reaction for light microscopy. The cells in the stomach were concentrated in the myenteric plexus and in the circular muscle layer. Along the greater curvature, cells were relatively sparse in the fundus, more frequent in the corpus and densest in the antrum. Along the lesser curvature, they were denser distally than proximally in all species except guinea pig. In the colon most cells lay with an axonal network at the circular muscle-submucosal interface. The axons were sparse in the cecum but uniformly conspicuous from the ileocolonic junction to the internal and sphincter. The density of the interstitial cells of Cajal in cat, dog, opossum, and rabbit rose from a relatively low level in the cecum to a maximum in the mid-colon, declining toward the rectum. In guinea pig, rat, and ferret, the levels throughout the most proximal colon were high. Since gastric slow waves are absent from the fundus, diminutive in the body, and prominent in the antrum, the density of interstitial cells of Cajal in the stomach roughly parallels the prominence of slow waves. Colonic slow waves are most prominent in the right colon and mid-colon, and so the density distribution of interstitial cells of Cajal in the colon also roughly parallels the prominence of slow waves.

Animals↗
PubMed1992

Biomechanical properties of duodenal wall and duodenal tone during phase I and phase II of the MMC.

We used a new method, impedance planimetry, to look at variations in compliance, tone, and distension-induced peristaltic activity during phase I and phase II of the migrating myoelectric complex (MMC) in the human duodenum. A balloon was inflated stepwise with pressures up to 30 cmH2O in the duodenum, while the pressure and balloon cross-sectional area (CSA) were measured simultaneously. The biomechanical wall parameters were calculated from these measurements. Nine duodenal phase IIIs were recorded in six subjects. A balloon pressure of 20 cmH2O induced a smaller CSA in early phase I [266 (236-324) mm2] than in late phase II [385 (276-474) mm2] (P < 0.05). Balloon distensions elicited no contractions in phase I, whereas they increased contractile activity 60% (P < 0.05) proximal to the balloon and 4% distal to the balloon in late phase II. Step distensions in phase I with balloon pressures between 10 and 30 cmH2O increased the CSA from 40 (30-81) to 645 (603-704) mm2. It increased circumferential wall tension from 35 (28-63) to 429 (402-466) mm x cmH2O and the pressure elastic modulus from 9.7 (9.0-14.7) to 33.8 (27.6-33.8) cmH2O, respectively. Thus compliance differs from phase I to phase II. This is most likely caused by increased smooth muscle tone during phase I. Duodenal wall stiffness increases with the balloon pressure applied.

Adult↗
PubMed1992

The consequences for renal function of widening of the interstitium and changes in the tubular epithelium of the renal cortex and outer medulla in various renal diseases.

The following parameters were measured in 63 renal biopsy specimens, most of which exhibited mesangioproliferative glomerulonephritis: the relative area of the interstitium and the area of the capillaries in the cortex and outer stripe of the outer medulla, and the area of the epithelium of the proximal tubules and of the ascending limbs of Henle's loop. The percentage of hyalinized glomeruli was also determined. Investigation of correlations between these values and parameters of renal function revealed the following: 1) The serum creatinine concentration increases and the endogenous creatinine clearance decreases significantly as the interstitium of both the cortex and the outer stripe of the outer medulla increases in width. 2) The urine osmolality decreases significantly as the epithelial areas of the proximal tubules and ascending limbs of Henle's loop decrease, and as the serum creatinine concentration rises and the areas of the interstitium increase. 3) No significant correlation exists between the percentage of hyalinized glomeruli and the urine osmolality. 4) The total area of the intertubular capillaries in the cortex decreases significantly as the interstitium in this area increases in width and as the serum creatinine concentration increases. 5) Compensatory hypertrophy of individual nephrons, as proposed by Bricker's hypothesis, was found only where more than 90% of the glomeruli were hyalinized.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Risk of cervical intraepithelial neoplasia in women with glomerulonephritis.

OBJECTIVE: To investigate the occurrence of cervical intraepithelial neoplasia in women with glomerulonephritis and its possible association with immunosuppressive treatment. DESIGN: Retrospective study of cytological or histological specimens from women presenting with glomerulonephritis and a group of case and age matched controls. SETTING: University department of pathology, Norway. PATIENTS: 81 women presenting with glomerulonephritis from 1981 to 1988, from whom gynaecological cytological or histological specimens were available. A group of 162 case and age matched controls. MAIN OUTCOME MEASURES: Age when glomerulonephritis of cervical intraepithelial neoplasia was diagnosed, type and characteristics of kidney lesion, stage of cervical intraepithelial neoplasia and presence of human papillomavirus, use of immunosuppressive treatment. RESULTS: Cervical intraepithelial neoplasia was more common in women with glomerulonephritis than in their controls (16/81 (20%) v 7/162 (4%), p less than 0.001) and was more advanced in those with glomerulonephritis than in the controls (9/81 (11%) of the study group had grade III cervical intraepithelial neoplasia compared with 1/162 (1%) of the controls). The increased occurrence of cervical lesions was independent of the use of immunosuppressive treatment, but the individual lesions tended to be more advanced when it was used (four of the seven cervical lesions in women with glomerulonephritis who had received immunosuppressive treatment were carcinoma in situ). Of the nine cervical lesions tested, seven were virus associated. CONCLUSION: Women with glomerulonephritis should have regular cervical smears, irrespective of their use of immunosuppressive treatment.

Adult↗
PubMed1991

Paradoxical relationship between substrates and agonist-induced contractions of opossum esophageal body and sphincter in vitro.

Possible differences in the abilities of esophageal body and lower esophageal sphincter muscles to utilize substrates to support agonist-induced contractions were studied. Strips of longitudinal, circular, and lower esophageal sphincter muscle from the opossum esophagus were first contracted to approximately 70% of the maximal contraction elicited by acetylcholine, histamine, or substance P. The tissues were then exhausted by exposure to 5 x 10(-4) M carbachol and a 15% O2-5% CO2-80% N2 gas mixture for 90 min. They were next reequilibrated with one of a number of alternative substrates and 95% O2-5% CO2 for 3 hr. Responses to the initial agonist doses were again noted and compared to controls. The alternative substrates were: 2-deoxyglucose, glucose, fructose 1-6 diphosphate, pyruvate, lactate, acetate, butyrate, caprylate, histidine, leucine, aspartate, alanine, succinate, acetoacetone, and beta-hydroxybutyrate. The results obtained show qualitative differences in the ability of the three muscle types to use these substrates. More importantly, however, the ability of any one substrate to support contractions was a function of the agonist used to stimulate the muscle. The evidence suggests, therefore, that not all pharmacologic receptors have equal access to intracellular energy sources.

Acetylcholine↗
PubMed1991

The distribution of myelinated nerve fibers in the mature opossum esophagus.

Myelination of nerve fibers could be important in establishing normal esophageal peristalsis. We therefore examined the general distribution and the age of appearance of myelinated nerve fibers in the smooth-muscle part of the esophagus of the American opossum. Tissues stained with thionein and Sudan black B were examined by light microscopy. Other tissues were prepared for electron microscopy and examined in the light microscope in Toluidine blue stained sections as well as at electron microscopy. In mature animals (weight greater than 2.0 kg, age greater than or equal to 1 year), myelinated nerve fibers, oriented mainly craniocaudally, were most abundant at the striated muscle-smooth muscle junction, and declined in density distally along the organ. They were nearly absent at the esophagogastric junction. They were more abundant in the stomach just below the esophagogastric junction. The myelinated nerve fibers commonly lay within sheathed fascicles that had the appearance of peripheral nerves, like the shunt fascicles of the stomach and colon. In immature animals myelinated fibers did not appear until a weight of about 1 kg was reached, 50 days after weaning and about 150 days after birth. Since the younger animals are presumably swallowing normally, myelination of the extrinsic nerves is not essential for esophageal motor function.

Animals↗
PubMed1991

Atrial natriuretic peptide concentrations in umbilical cord plasma from pre-eclamptic women.

Atrial natriuretic peptide (ANP) was measured in arterial and venous umbilical cord plasma at the time of delivery by cesarean section in pre-eclamptic (n = 7) and normal women (n = 6). In addition venous samples were obtained from pre-eclamptic (n = 7) and normal pregnant women (n = 7) near term. ANP plasma levels were higher in pregnant women with pre-eclampsia than in normal pregnant women (27.9 +/- 4.4 [mean +/- SEM] and 14.1 +/- 2.5 pmol l-1, respectively, P less than 0.05). Immediately after delivery plasma ANP in pre-eclamptic mothers was 66.7 +/- 12.8 pmol l-1 compared to 13.9 +/- 2.2 pmol l-1 in normal mothers (P less than 0.01). However, in the pre-eclamptic group the levels of ANP in arterial and venous umbilical cord plasma (19.5 +/- 4.2 and 16.7 +/- 4.3 pmol l-1, respectively) were significantly (P less than 0.01) lower than ANP levels in arterial and venous cord plasma (39.6 +/- 1.0 and 31.1 +/- 4.2 pmol l-1, respectively) from normal mothers. It is concluded that the increased ANP plasma level in pre-eclamptic women originates from a maternal source. In addition, since the ANP level is lower in cord plasma than in maternal plasma in pre-eclampsia, feto-placental volume homeostasis may also be changed in pre-eclampsia.

Adult↗
PubMed1990

Quantitative measurement of Fc receptor activity on human peripheral blood monocytes and the monocyte-like cell line, U937, by laser flow cytometry.

The expression of high affinity Fc receptors for IgG (FcRI) on the cell line U937 has been measured by flow cytometry, using fluorescein isothiocyanate-conjugated human IgG (FITC-IgG) calibrated spectrofluorimetrically against lasergrade fluorescein (Fl). A standard curve is presented, relating the effective fluorescence in terms of fluorescein equivalents per IgG molecule, to the degree of conjugation of FITC-IgG. The flow cytometer was calibrated with commercially available fluorescein-coupled latex beads. The quantitation of FcRI, in terms of sites per cell and affinity constants, was compared with a radioligand assay performed concurrently on the same cell population. Good agreement between the two assays was observed. The Fc receptors on peripheral blood monocytes were measured in unpurified lysed blood by gating on forward/side scatter. Monomer IgG binding to monocyte FcRII or FcRIII cannot be measured in direct IgG radioligand analyses because of the low affinity of these receptors and their low numbers per cell. However, flow cytometry may be employed for measuring both high and low affinity ligand-FcR interactions, using monomer FITC-IgG.

Antigens, Differentiation↗
PubMed1990

Acute renal failure in man: new aspects concerning pathogenesis. A morphometric study.

The morphometric investigation of the proximal and distal tubules, the cortical interstitium, the intertubular capillaries, the renal corpuscles and the juxtaglomerular apparatuses (JGAs) in 56 cases in the oligoanuric, polyuric, and normuric phases of human acute renal failure (ARF), 6 cases of myeloma kidney with clinically confirmed ARF and 21 control kidneys revealed the following: (1) The main pathological change in human ARF is swelling of the epithelial cells of the proximal and distal tubules. Necrosis of these cells was observed in some cases but usually only as single cell necroses. (2) The interstitium of the cortex and of the outer stripe of the outer medulla is significantly widened in most cases of ARF. (3) In proximal tubules proximal to occluding casts (which were observed only in the plasmacytoma cases), the lumina are not widened but are narrower than normal, and the cross-sectional area of the epithelium is not greater but smaller than normal. (4) The JGAs were significantly larger in kidneys in the oligoanuric phase of ARF (with 1 exception) than in normal kidneys. In the normuric and polyuric phases they were slightly (not significantly) smaller than normal. In myeloma kidneys with occluding casts and/or diffuse interstitial fibrosis, the JGAs were significantly smaller than normal. From these findings it is concluded that: (1) The fall in glomerular filtration rate (GFR) in the postshock phase of ARF is not caused by nonselective back-diffusion of the primary urine through necrotic tubules or by compression of the lumina of the proximal and distal tubules by interstitial edema. A fall in GFR associated with occluding casts in the distal tubules is found only in the myeloma kidney and does not lead to widening of the proximal tubules but to tubular atrophy and narrowing of the lumen. (2) The casts seen in the lumina of the ascending limb of Henle's loop in some cases of ARF, which consist of hemoglobin, Tamm-Horsfall protein or desquamated blebs, do not occlude the lumen, since they are not associated with atrophy or luminal dilatation of the proximal tubules. (3) The JGAs with their secretory product renin-angiotensin II, together with adenosine, which is released in kidneys with ischemic or toxic damage, play a critical role in the pathogenesis of ARF. (4) In myeloma kidneys with ARF, in which the JGAs are markedly atrophic, the potentiated effect of adenosine that has been observed with a chronic absence of urine flow probably leads to a progressive, irreversible drop in GFR associated with tubular atrophy.

ADP-Ribosylation Factor 6↗
PubMed1989

[Anterior gastropexy using the Boerma method in gastroesophageal reflux].

The results obtained in 38 patients with gastro-oesophageal reflux who had been submitted to operation by Boerema's method are presented. Twenty-nine (76%) became entirely symptomfree and eight (21%) experienced reduction of symptoms. Postoperative oesophageal stenosis was demonstrated in five patients.

Adolescent↗
PubMed1989

[Readmitted patients at a medical ward. 1. Health conditions].

The object of this investigation was to describe the health and social-medical conditions of readmitted patients and to assess which of these conditions was the main reason for readmission. A total of 166 patients (with an average age of 73 years) readmitted to the ward within three months of the last discharge from the ward were interviewed about their health, social and housing conditions in the period prior to admission. In this first report from the investigation it was found that 57% were readmitted within one month. 71% stated that they had experienced symptoms from the heart and/or respiratory system and 52% had experienced symptoms from the locomotor system. Only 13% did not receive any daily prescription drugs. Approximately 1/3 considered their health to be good and 1/3 poor, respectively. These results were compared with the data available in the literature about the health conditions of non-hospitalized elderly persons. It was demonstrated that the readmitted patients had more health complaints, a more extensive medication and considered their health worse.

Adult↗