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Biomedical subjects

P Hansen

Publications and source records attributed to P Hansen.

At least 37 records · Page 2Linked to original sources
PubMed2000

Variations in self-reported health status: results from a New Zealand survey.

AIMS: To report measures of the self-reported health of a sample of the New Zealand adult population elicited using the EuroQol Group's EQ-5D questionnaire, and to investigate variations in these measures, according to respondents' socio-demographic characteristics. METHODS: Personal health status questions were included in a self-completed postal questionnaire mailed to a non-stratified sample of 3000 New Zealanders, selected at random from the electoral roll. 1350 questionnaires were completed and returned. Each respondent rated their health on the five EQ-5D dimensions- mobility, self care, usual activities, pain/discomfort and anxiety/depression- and assigned a global score to their profile. RESULTS: Pain/discomfort was the most commonly experienced health problem, with 41% of all respondents and 63% of over-70 year olds reporting moderate or extreme problems. Just 4.5% of respondents reported problems with self-care. Respondents were more likely to report problems on each of the five dimensions and to have a lower global score if they smoked, if they were unemployed, a houseworker or retiree, and if their education did not continue past the minimum school leaving-age, or they did not have a degree or equivalent qualification. Problems on all dimensions were more common the older the respondent, and the global score was lower for over-70 year olds than for younger people. Neither the global score nor the incidence of problems on any of the dimensions was related to sex or ethnicity. CONCLUSIONS: The EQ-5D is a potentially useful instrument for monitoring health in the New Zealand context. Further research to explore its validity and reliability, particularly for Maori, would be valuable.

Adult↗
PubMed2000

Hand-assisted laparoscopic surgery (HALS) with the HandPort system: initial experience with 68 patients.

OBJECTIVE: To evaluate the feasibility and potential benefits of hand-assisted laparoscopic surgery with the HandPort System, a new device. SUMMARY BACKGROUND DATA: In hand-assisted laparoscopic surgery, the surgeon inserts a hand into the abdomen while pneumoperitoneum is maintained. The hand assists laparoscopic instruments and is helpful in complex laparoscopic cases. METHODS: A prospective nonrandomized study was initiated with the participation of 10 laparoscopic surgical centers. Surgeons were free to test the device in any situation where they expected a potential advantage over conventional laparoscopy. RESULTS: Sixty-eight patients were entered in the study. Operations included colorectal procedures (sigmoidectomy, right colectomy, resection rectopexy), splenectomy for splenomegaly, living-related donor nephrectomy, gastric banding for morbid obesity, partial gastrectomy, and various other procedures. Mean incision size for the HandPort was 7.4 cm. Most surgeons (78%) preferred to insert their nondominant hand into the abdomen. Pneumoperitoneum was generally maintained at 14 mmHg, and only one patient required conversion to open surgery as a result of an unmanageable air leak. Hand fatigue during surgery was noted in 20.6%. CONCLUSIONS: The hand-assisted technique appeared to be useful in minimally invasive colorectal surgery, splenectomy for splenomegaly, living-related donor nephrectomy, and procedures considered too complex for a laparoscopic approach. This approach provides excellent means to explore, to retract safely, and to apply immediate hemostasis when needed. Although the data presented here reflect the authors' initial experience, they compare favorably with series of similar procedures performed purely laparoscopically.

Abdomen↗
PubMed2000

Transgenic mice overexpressing GLUT-1 protein in muscle exhibit increased muscle glycogenesis after exercise.

The purpose of the present study was to determine the rates of muscle glycogenolysis and glycogenesis during and after exercise in GLUT-1 transgenic mice and their age-matched littermates. Male transgenic mice (TG) expressing a high level of human GLUT-1 and their nontransgenic (NT) littermates underwent 3 h of swimming. Glycogen concentration was determined in gastrocnemius and extensor digitorum longus (EDL) muscles before exercise and at 0, 5, and 24 h postexercise, during which food (chow) and 10% glucose solution (as drinking water) were provided. Exercise resulted in approximately 90% reduction in muscle glycogen in both NT (from 11.2 +/- 1.4 to 2. 1 +/- 1.3 micromol/g) and TG (from 99.3 +/- 4.7 to 11.8 +/- 4.3 micromol/g) in gastrocnemius muscle. During recovery from exercise, the glycogen concentration increased to 38.2 +/- 7.3 (5 h postexercise) and 40.5 +/- 2.8 micromol/g (24 h postexercise) in NT mice. In TG mice, however, the increase in muscle glycogen concentration during recovery was greater (to 57.5 +/- 7.4 and 152.1 +/- 15.7 micromol/g at 5 and 24 h postexercise, respectively). Similar results were obtained from EDL muscle. The rate of 2-deoxyglucose uptake measured in isolated EDL muscles was 7- to 10-fold higher in TG mice at rest and at 0 and 5 h postexercise. There was no difference in muscle glycogen synthase activation measured in gastrocnemius muscles between NT and TG mice immediately after exercise. These results demonstrate that the rate of muscle glycogen accumulation postexercise exhibits two phases in TG: 1) an early phase (0-5 h), with rapid glycogen accumulation similar to that of NT mice, and 2) a progressive increase in muscle glycogen concentration, which differs from that of NT mice, during the second phase (5-24 h). Our data suggest that the high level of steady-state muscle glycogen in TG mice is due to the increase in muscle glucose transport activity.

Animals↗
PubMed1999

Shared structural motifs in TCR of glycopeptide-recognizing T cell hybridomas.

The TCR structure of T cell hybridomas recognizing a tumor glycan-defined epitope has been studied using reverse transcriptase-PCR and gene sequencing. The hybridomas had been raised against a glycopeptide, T72(Tn), consisting of the mouse hemoglobin-derived decapeptide Hb(67 - 76), O-glycoslated in position 72 with alpha-D-GalNAc. The glycan-specific hybridomas varied widely in their use of Valpha genes although Valpha4 was predominant, being present in one third of them. The Vbeta gene usage was more restricted and dominated by Vbeta1 and Vbeta15. There was no correlation between Valpha and Vbeta usage and antigen fine specificity of the hybridomas. The overall amino acid composition of the complementarity-determining region (CDR) 3 of the hybridomas was dominated by small polar residues such as Gly, Asn, Ser, Glu and Ala, amino acids reported in the literature to be frequent in glycan-recognizing proteins. Furthermore, the CDR3 of most hybridomas also contained an aromatic residue with preference for Tyr. A few of the hybridomas raised against the T72(Tn) glycopeptide were peptide specific, i. e. they responded to the unglycosylated peptide only. The amino acid usage of their CDR3 regions was not radically different from that of the glycopeptide specific hybridomas. They also preferentially used Valpha4. However, Vbeta4 and Vbeta8 were the dominating beta chains.

Amino Acid Sequence↗
PubMed1999

Altered cholinesterase and monooxygenase levels in Daphnia magna and Chironomus riparius exposed to environmental pollutants.

Biochemical indices were investigated for their potential use as variables of sublethal toxicity in Daphnia (cholinesterase) and Chironomus (cholinesterase and biotransformation enzymes). Parathion, dichlorvos, and aldicarb caused dose-related inhibition of cholinesterase (ChE) in 24-h bioassays with both species. Ratios of Daphnia and Chironomus ChE IC50 values to corresponding immotility EC50 values derived from the same experiment covered the range 0.26 to 1.2. Estimates of the ChE inhibition caused by the immotility EC50 were in the range 53-99% below control activity. ChE IC50 values of dichlorvos, parathion, and aldicarb were 0.17, 0.61, and 95 microg/liter in Daphnia and 6.2, 2.9, and 27 microg/liter in Chironomus, respectively. Cytochrome P450-dependent monooxygenase activities (ethoxyresorufin-O-deethylase, methoxyresorufin-O-deethylase, and ethoxycoumarin-O-deethylase) were detectable in Chironomus but not in Daphnia. Chironomus monooxygenase activities were significantly inhibited to about 30% of control values after 4 days of exposure to 50 microg/liter 3, 4-dichloroaniline but remained unchanged by 0.5 microg/liter parathion. An approximately 1.3-fold induction of monooxygenase activities was caused by the model inducer naphthalene (0.1mg/liter). These results suggest that cytochrome P450-dependent monooxygenase activities may be useful variables in toxicity tests with aquatic insects.

Aldicarb↗
PubMed1999

[Arrhythmias in patients with congenital heart disease and their impact on prognosis].

Patients with congenital heart disease have an increased chance to suffer from brady- as well as tachyarrhythmias. The impact of these on quality of life, morbidity and mortality is more often imperative as compared to heart-healthy individuals. The substrate for these may be either congenital or acquired. Improvements of the surgical management of these patients have led, on the one hand, to improved survival rates with prolonged life expectancy within the last 2 decades, which on the other hand provided the basis for a higher rate of acquired cardiac arrhythmias. Together, this not only challenges diagnostics and therapy but also the prognostic relevance of these arrhythmias. The therapeutic strategies and prognostic markers have until now mostly been based on retrospective studies limited by the low number of patients and inhomogeneous patient selection. Despite these limitations, an increased risk of sudden cardiac death has been substantiated for certain patient groups, e.g., those operated on by the Mustard- or Senning procedures in patients with transposition of the great arteries and patients operated on with correction of the tetralogy of Fallot. However, until now it has not been possible to identify reliable markers for establishing the risk on an individual basis within these patient cohorts. For achieving reliable data on the symptomatic and prognostic effects of present-day--as well as new-coming--therapeutic strategies, it is mandatory to perform prospectively based, randomized multicenter studies. Furthermore, the well-appreciated synergism of hemodynamically and primarily of arrhythmia-based effects on prognosis could potentially be divided into their relative weight to better guide appropriate, substrate-related therapy. In addition, this should help to get better estimates of the risk for sudden cardiac death in different, etiologically homogeneous, groups of patients with congenital heart disease.

Arrhythmia, Sinus↗
PubMed1999

Comparison of laparoscopic ultrasonography and fluorocholangiography in 300 patients undergoing laparoscopic cholecystectomy.

BACKGROUND: This study compares laparoscopic ultrasonography to fluorocholangiography in detecting common bile duct (CBD) stones and delineating biliary anatomy. METHODS: A prospective nonrandomized study of 300 consecutive patients undergoing laparoscopic cholecystectomy in a university hospital was performed. After port placement but before dissection, laparoscopic ultrasonography of the extrahepatic CBD was performed in both transverse and longitudinal planes. Cystic duct fluorocholangiography was attempted in all patients. RESULTS: Of 300 patients, CBD stones were detected in 26 (9%) with 25 of these (96%) detected on laparoscopic ultrasonography. Sonography identified the location and size of the CBD as well as anomalous anatomy prior to dissection. No CBD injuries were encountered. End-fire transducers were easier to use than rigid or flexible side-fire transducers; all gave excellent image quality. CONCLUSIONS: In this large study, laparoscopic ultrasonography and fluorocholangiography were equally sensitive in detecting CBD stones. Sonography delineates the biliary anatomy noninvasively and does not require dissection or opening of the biliary system. Laparoscopic ultrasonography may improve the safety of laparoscopic cholecystectomy, especially in cases of acute inflammation or distorted anatomy.

Cholangiography↗
PubMed1999

Failure of autoresuscitation in weanling mice: significance of cardiac glycogen and heart rate regulation.

"Autoresuscitation" (AR) is the spontaneous recovery from hypoxic apnea by gasping. We examined aspects of heart function in two situations: 1) the maturationally acquired failure of AR that is characteristic of SWR, but not BALB/c, weanling mice and 2) AR failure in BALB/c mice induced by repeated exposures to anoxia. We determined maturational changes in heart and liver glycogen. Unlike liver glycogen levels, heart glycogen levels in SWR mice differed from those in BALB/c mice. They were consistently much lower throughout maturation and reached a nadir during the brief period when SWR weanling mice are vulnerable to AR failure. Also, rate of cardiac glycogen utilization in vulnerable SWR mice was lower than that of same-aged BALB/c mice and was nil during the latter one-half of the gasping stage when heart function is critical for AR success. Therefore, because glycogen utilization reflects cardiac work, heart failure could explain AR failure in SWR weanlings. Additionally, the increase in hypoxic heart rate that occurs with maturation is developmentally delayed in SWR mice, and this may contribute to their AR failure. Cardiac glycogen was not fully depleted in BALB/c mice during repeated anoxic exposures, indicating other reasons for AR failure. We view these findings as a potential model for the age-related peak in incidence of sudden infant death syndrome.

Age Factors↗
PubMed1998

Isolation and purification of immunoglobulins from chicken eggs using thiophilic interaction chromatography.

We report on the use of thiophilic interaction chromatography for the purification of IgY from egg yolk. This procedure permits the purification to homogeneity of IgY in a single chromatographic step after ammonium sulfate fractication. This study also compares the use of an improved T-gel which has a higher capacity for immunoglobulin than the original T-gel, having a capacity in excess of 25 mg IgY/ml resin. The recovery from this procedure is close to 100%, providing a simple and efficient means for purifying IgY from egg yolk. We also determined that the amount of specific antibody present in egg yolk from an immunised chicken is around 1% of total IgY.

Animals↗
PubMed1998

Bolus injection (2-4 min) versus short-term (10-20 min) infusion of 5-fluorouracil in patients with advanced colorectal cancer: a prospective randomised trial. Nordic Gastrointestinal Tumour Adjuvant Therapy Group.

The use of bolus 5-fluorouracil (5-FU) as a short-term infusion over 10-30 min is increasing at the cost of a push injection, mainly due to practical advantages. Since even a short prolongation of the administration time results in lower 5-FU peak and area under the curve (AUC) levels, there might be a risk of decreased efficacy. The aim of this study was to compare a rapid intravenous (i.v.) 5-FU injection and a short-term 5-FU infusion with respect to objective responses and toxicity in patients with advanced colorectal cancer. 203 patients with measurable advanced colorectal cancer were randomised to bolus 5-FU either as an injection for 2-4 min or as a short-term infusion lasting 10-20 min. In both groups, the 5-FU dose was 500 mg/m2 and leucovorin 60 mg/m2 was given 40 min after the start of 5-FU. Treatment was given on two successive days every other week until progression. Objective tumour regression was seen in 27/100 (27%) in the injection group and in 13/103 (13%) in the infusion group (P = 0.02). Severe toxicity was rare and did not differ significantly between the groups. Progression-free survival tended to be longer in the injection group (P = 0.07), but overall survival did not differ between the groups. Bolus 5-FU should be administered as a rapid i.v. injection rather than as a short-term infusion, since the former rate of administration results in a higher response rate without being significantly more toxic.

Adult↗
PubMed1998

Template for surgical crown lengthening: fabrication technique.

This article describes a technique for the easy fabrication of a template to facilitate surgical lengthening of the clinical crown to enhance esthetics and/or increase retention of a fixed prosthesis. The use of this surgical guide should result in more predictable clinical results.

Crown Lengthening↗