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Biomedical subjects

J Kristensen

Publications and source records attributed to J Kristensen.

At least 55 records · Page 3Linked to original sources
PubMed1993

Cervical conization and preterm delivery/low birth weight. A systematic review of the literature.

OBJECTIVE: Evaluate the effect of cervical conization on preterm birth/low birth weight (LBW). DESIGN: A systematic review of the literature using external or internal controls. RESULTS: The typical odds ratio for preterm delivery in women with prior cervical conization using external controls was 3.23 (95% confidence interval 2.29-4.55). Using internal controls the typical odds ratio for LBW was 2.97 (95% confidence interval 1.09-8.05). Using external controls the typical odds ratio for LBW was 2.31 (95% confidence interval 1.33-3.99). CONCLUSION: Women with cervical conization are at higher risk for preterm birth than external controls, and the surgical intervention as such is a major determining factor.

Cervix Uteri↗
PubMed1993

Increased risk of preterm birth in women with cervical conization.

OBJECTIVE: To determine the relation between cervical conization and preterm birth. METHODS: All Danish women with singleton pregnancies who gave birth to their first infant in 1982 and second infant during the time period 1982-1987 were included in a register-based cohort study. Information on pregnancy outcome and cervical conization in 1977-1987 was obtained from the Medical Birth Register and the National Register of Hospital Discharges. RESULTS: In a cohort of 14,233 women, 170 had cervical conization. Thirty-four had cervical conization before the first delivery, 62 between the first and the second, and 74 after the second delivery. Women with cervical conization had a significantly higher risk of preterm birth. In addition, women with subsequent cervical conization had a higher risk of preterm birth in previous pregnancies. However, the risk of preterm birth was higher in women with previous than with subsequent cervical conization. CONCLUSIONS: Cervical conization is correlated with preterm birth. Because women with subsequent cervical conization have an increased risk of preterm birth in preceding pregnancies, factors other than the surgical intervention may contribute to the significantly increased risk of preterm birth.

Adult↗
PubMed1992

Selective cytotoxic activity of cyclosporins against tumor cells from patients with B cell chronic lymphocytic leukemia.

A fluorometric microculture cytotoxicity assay was employed for the study of cyclosporin A induced cytotoxicity in tumor samples from patients with B type chronic lymphocytic leukemia (B-CLL). Tumor cells from patients with B-CLL were found to be significantly more sensitive to the cytotoxic actions of cyclosporin A than normal blood mononuclear cells and tumor cells obtained from patients with different types of acute leukemia and solid tumors. The effect of cyclosporin A on B-CLL samples could be reproduced by a non-immunosuppressive cyclosporin A analogue. One B-CLL patient treated with cyclosporin A responded with a significant decrease in tumor mass and alleviation of anemia and B symptoms. The results show that cyclosporin A and its non-immunosuppressive analogues appear selectively toxic to B-CLL cells, an observation which may have clinical implications.

Cell Survival↗
PubMed1992

Laboratory determination of chemotherapeutic drug resistance in tumor cells from patients with leukemia, using a fluorometric microculture cytotoxicity assay (FMCA).

An automated fluorometric microculture cytotoxicity assay (FMCA) based on the measurement of fluorescence generated from cellular hydrolysis of fluorescein diacetate (FDA) to fluorescein was employed for chemotherapeutic-drug-sensitivity testing of tumor-cell suspensions from patients with leukemia. Fluorescence was linearly related to cell number, and reproducible measurements of drug sensitivity could be performed using fresh or cryopreserved leukemia cells. A marked heterogeneity with respect to chemotherapeutic drug sensitivity was observed for a panel of cytotoxic drugs tested in 43 samples from 35 patients with treated or untreated acute and chronic leukemia. For samples obtained from patients with chronic lymphocytic and acute myelocytic leukemia, sensitivity profiles for standard drugs corresponded to known clinical activity and the assay detected primary and acquired drug resistance. Individual in vitro/in vivo correlations indicated high specificity with respect to the identification of drug resistance. The results suggest that the FMCA may be a simple and rapid method for in vivo-representative determinations of chemotherapeutic drug resistance in tumor cells obtained from patients with leukemia.

Antineoplastic Agents↗
PubMed1992

Noninvasive cardiac output determined with a new method based on gas exchange measurements and carbon dioxide rebreathing: a study in animals/pigs.

A system has been designed to determine cardiac output noninvasively. The system's main component is a closed breathing circuit and it measures oxygen uptake (VO2), carbon dioxide elimination (VCO2), and end-tidal CO2 partial pressure (PET). As an integral part of the system, periods of CO2 rebreathing can be automatically implemented. The CO2 partial pressure of oxygenated mixed venous blood (Pv) is obtained from the measured exponential rise of the PET value during such a CO2 rebreathing maneuver. A new method is described for estimating the pulmonary blood flow, alveolar ventilation, cardiac output (CO), and mixed venous oxygen saturation (SVO2) from PV, PET, VO2, VCO2, tidal volume, and arterial oxygen saturation. The method was evaluated in 6 anesthetized and mechanically ventilated pigs. A wide range of cardiac output, shunt fractions, and dead space to tidal volume ratios were induced by combinations of bronchoalveolar lavage, hypervolemia, hypovolemia, and variable levels of positive end-expiratory pressure (PEEP). The bias between the CO obtained with the noninvasive technique (CO L/min) and the thermodilution CO (Qt L/min) was 0.13 L/min (SD = 0.78 L/min) and the correlation was N = 64; R = 0.92; CO = 0.95*Qt + 0.38. The bias obtained for double determinations with the noninvasive CO technique was 0.3 L/min (SD = 0.5 L/min). The bias between the noninvasive estimates of Svo2 and the directly measured values was 1.1% (SD = 9.3%). For double determination with the noninvasive technique the bias was -0.9% (SD = 4.7%). It is concluded that in mechanically ventilated pigs the proposed method produces good estimates of CO and SVO2 also in the presence of significant ventilation/perfusion mismatch.

Anesthesia, Closed-Circuit↗
PubMed1992

In vitro analysis of drug resistance in tumor cells from patients with acute myelocytic leukemia.

A 72 hours fluorometric microculture cytotoxicity assay (FMCA) was used for the study of chemotherapeutic drug resistance in tumor cell suspensions from patients with acute myelocytic leukemia (AML). A marked heterogeneity with respect to sensitivity was observed for a panel of cytotoxic drugs tested in 76 samples from 60 patients with treated or untreated AML. Primary resistance to vincristine (Vcr) and prednisolone in untreated AML was observed as well as 'acquired' resistance to several other antileukemic drugs. Cross resistance patterns for AML active drugs revealed significant positive relationships between anthracyclines, VP16 and amsacrine (Amsa), whereas mitoxantrone (Mitox) was more weakly correlated. Sensitivity to cytosine arabinoside was unrelated to the anthracyclines, VP16, Amsa and Mitox but showed a significant relationship to 6-thioguanine. Several resistance modifying agents, including the novel non-immunosuppressive cyclosporin A analogue PSC 833, were able to potentiate the effects of doxorubicin and Vcr at concentrations achievable in the clinic. However, the pattern of activity was heterogenous and the frequency of responsive samples was higher in relapse compared to de novo cases. Individual in vitro/in vivo correlations based on quartile distributions of all accumulated drug sensitivity data from AML patients indicated a high specificity with respect to the identification of drug resistance. The results suggest that the FMCA may provide clinically valuable information on chemotherapeutic drug resistance in AML.

Antineoplastic Agents↗
PubMed1992

Feasibility of the fluorometric microculture cytotoxicity assay (FMCA) for cytotoxic drug sensitivity testing of tumor cells from patients with acute lymphoblastic leukemia.

The automated fluorometric microculture cytotoxicity assay (FMCA) was used for chemotherapeutic drug sensitivity testing of fresh and cryopreserved tumor cells from patients with acute lymphoblastic leukemia (ALL) at diagnosis and relapse. The technique success rate was 87% for fresh and 81% for cryopreserved samples. Up to 16 different cytotoxic drugs were routinely tested, but neither asparaginase nor methotrexate produced dose-response related cell kill. FMCA data showed good correlation to the well established Disc assay and the drug sensitivity reported by the FMCA was in good agreement with known clinical activity. Samples from children and initial ALL tended to be more drug sensitive than those from adults and ALL at relapse, respectively. For 36 samples clinical outcome was correlated to the quartile position in comparison to all other samples for the most in vitro active drug actually given to the patient. For patients with samples in the first, second, third, and fourth quartiles, the probabilities of complete remission were 89, 57, 38, and 0%, respectively. Using the median value as cut-off line, the sensitivity and specificity of the assay were 87 and 62%, respectively. It is concluded that the FMCA with a minimum of effort and with high success rate report clinically relevant drug sensitivity profiles for ALL.

Antineoplastic Agents↗
PubMed1991

Fibre-optic bronchoscopic evaluation of tracheal tube position.

Verification of tracheal tube position by fibre-optic bronchoscopy was evaluated in 20 critically ill adult patients. The distance between the carina and the tube was measured by direct visualization with a fibre-optic bronchoscope and compared with the corresponding measurement obtained from a concomitant chest radiograph. The measured values did not differ significantly and in 18 out of 20 patients the accuracy was within 2 cm. No adverse effects were observed. We conclude that verification of tracheal tube position by fibre-optic bronchoscopy is a safe alternative to chest X-ray.

Bronchoscopy↗
PubMed1990

[Laparoscopic sterilization of women by electrocoagulation. A 5-year material].

A retrospective questionnaire investigation was undertaken involving 253 women who had been sterilized by electrocoagulation in a small department of general surgery during a five-year period. This revealed a frequency of pregnancy of 1.6% following a total period of observation averaging 42 months. The average age of the women in this material was 35.8 years and these had, on an average, 2.8 children. 4.0% regretted the intervention. The majority of the women (97.0%) would choose laparoscopic sterilization as the method of contraception today, if they should choose again. The per- and postoperative frequency of complications was 4.3%. The operating time was 33.8 minutes on an average and the duration of postoperative hospitalization was 1.5 days on an average. On a average, the patients felt well after 7.9 days and they resumed sexual activities after an average of 16.7 days. The conclusion of this investigation is that laparoscopic sterilization by electrocoagulation carried out by an experienced surgeon in a small department for general surgery is a safe and cheap method of sterilization which is reasonably free from complications for the patients.

Adult↗
PubMed1990

Ringer's acetate and dextran-70 with or without hypertonic saline in endotoxin-induced shock in pigs.

The effects of Ringer's acetate, 6% dextran-70, 7.5% NaCl, and the combination of 7.5% NaCl and dextran-70 were tested in resuscitation from endotoxin shock induced by continuous iv infusion of Escherichia coli endotoxin in pigs. After about 3 h, a reproducible shock state was achieved and treatment was started, governed by the left atrial pressure. The hypertonic solutions (7.5% NaCl and 7.5% NaCl in dextran-70) did not show any overall advantages over the isotonic solutions (Ringer's acetate and dextran-70). Only transient beneficial hemodynamic effects lasting less than 30 min after infusion were seen. When dextran-70 was administered, cardiovascular function was markedly improved and oxygen delivery (DO2) and survival were significantly higher compared with the crystalloid groups (Ringer's acetate and 7.5% NaCl). Administration of large amounts of Ringer's acetate resulted in an immediate deterioration of pulmonary function. It was difficult to elevate left atrial pressure or even to keep it at baseline level, and cardiac index was only transiently increased. The overall result was a deterioration of DO2 and poor survival compared with the dextran-70 treated pigs. We conclude that dextran-70 is superior to Ringer's acetate in resuscitation from endotoxin-induced shock in pigs. Furthermore, we found no role for the use of hypertonic saline, alone or in combination with dextran, in the treatment of this type of prolonged endotoxin shock.

Animals↗
PubMed1990

A comparison of glucose-free 2% lidocaine and hyperbaric 5% lidocaine for spinal anaesthesia.

Fifty patients scheduled to undergo transurethral surgery of the bladder were allocated to receive spinal anaesthesia with either glucose-free 2% lidocaine (80 mg) or hyperbaric 5% lidocaine (80 mg). Onset time, cephalad spread of analgesia, duration of analgesia, duration and intensity of motor block, quality of analgesia, and the patients' ability to walk 5 m and to micturate postoperatively were assessed. Onset and spread of analgesia were fast and comparable in the two groups. At 60 min, the median segmental level of analgesia was T9 and T10 for the 2% and the 5% group, respectively, allowing transurethral surgery to be performed for at least 1 h. In the 2% group the motor block was more pronounced and longer lasting than in the 5% group. Two patients in the 5% group needed general anaesthesia because of pain. The time from injection of the spinal anaesthetic until the patients were able to walk 5 m and to micturate was equal in the two groups, and 89% of all the patients were able to walk and micturate within 4 h. It is concluded that spinal anaesthesia with 80 mg and 2% or 5% lidocaine provides analgesia for transurethral surgery and is characterized by fast recovery of motor and detrusor function.

Analgesia↗
PubMed1989

[Early retirement among the 1914 population in Glostrup. Significance of social and health problems in choosing early retirement].

In the population investigation in Glostrup, the 1914 population was examined at the ages of 50, 60 and 67 years. A total of 141 participants at the 67 years examination (106 men and 35 women) stated that they had chosen early retirement prior to transition to old age pensions. The social and health circumstances of these early retirees at the ages of 50 and 60 years are compared with the circumstances in the 243 persons in the cohort (154 men and 89 women) who remained occupationally active until the age for old age pensioning. In the group of early retirees, unskilled men predominated. Out of those who found the occupational environment stressful at the ages of 50 or 60 years, a majority subsequently chose early retirement. Significantly more of the men with abnormal findings in the heart and lungs at the health examinations subsequently chose early retirement. Where the remaining health variables were concerned, no connection could be found with subsequent choice of early retirement. Where the health conditions at the age of 60 years were concerned, a tendency for more frequent choice of early retirement was observed in men with a series of abnormal conditions in the lungs and intestinal tract but no distinct tendency was observed in women. Where both sexes were concerned, an increasing tendency to subsequent choice of early retirement was observed with increasing incidense of cardiovascular risk factors at the age of 60 years. Data concerning low back pain at the age of 60 years did not reveal any connection with subsequent choice of early retirement but may suggest early elimination of persons with low back pain.

Age Factors↗
PubMed1989

[Comparison of 2 non-ionic radiographic contrast agents in intravenous subtraction angiography].

A prospective randomised comparison was undertaken of iopromide and iopamidol in intravenous digital subtraction angiography. This revealed that the two contrast agents produced pictures of similar quality. A slightly increased number of side effects in patients with cardio-pulmonary disease was demonstrated in the investigation and a slightly increased number of side effects after injection of iopamidol.

Angiography↗
PubMed1989

[Preoperative evaluation of arteriosclerotic symptoms in the lower extremities by means of intravenous digital subtraction angiography].

Intravenous DSA was performed in 106 patients with symptoms of arterial insufficiency in the lower extremities, requiring treatment according to preceding clinical examination. The examinations were carried out using a 36.5 cm (14 in.) intensifier and a 5.5 F pigtail catheter located centrally. 71% of the examinations were carried out on out-patients. No complications were observed. In 96% of the cases, the intravenous DSA provided sufficient information to make decisions about treatment.

Adult↗
PubMed1989

Spinal anaesthesia with glucose-free 2% lignocaine. Effect of different volumes.

Spinal anaesthesia with 2, 3 or 4 ml of glucose-free 2% lignocaine was studied in 64 patients undergoing transurethral surgery of the bladder. Cephalad spread of analgesia, onset time, duration of analgesia, duration of motor block, quality of analgesia, and the cardiovascular effects were assessed. Two ml of 2% lignocaine was insufficient to produce reliable analgesia. Three ml provided sufficient analgesia in most of the patients, but 4 ml was needed to guarantee sufficient analgesia in all patients. Onset times for analgesia and motor block were 10-20 min. After 4 ml the median and interquartile values were: maximum cephalad spread: T8, (T10-T5); time from injection to regression of analgesia to T11: 84 min, (60-103 min); duration of complete motor block: 90 min, (60-120 min). All patients in the 3-ml and 4-ml groups developed complete motor block. There was a positive correlation between the dose and the duration of analgesia and motor block. A positive correlation, although weaker, was also seen between the dose and the maximum cephalad spread of analgesia. There was an inverse relationship between the cephalad spread of analgesia and the duration of motor block. Falls in systolic blood pressure greater than 30% were noted in seven patients in whom the cephalad spread of analgesia was higher than in the rest of the patients. Spinal anaesthesia with glucose-free 2% lignocaine in doses of 3-4 ml provides reliable analgesia for transurethral surgery of the bladder.

Aged↗
PubMed1989

The cardiovascular effects of vecuronium during halothane anaesthesia.

In a double-blind, placebo-controlled, prospective randomized trial in 70 otherwise healthy patients undergoing elective surgery of the thyroid gland, the breast, the inguinal canal or the lower limbs, we studied the cardiovascular effects of vecuronium during halothane-nitrous oxide anaesthesia. Vecuronium was found to have no clinically significant influence on heart rate or mean arterial pressure, before or during surgery. Bradycardia was a rare event under the special conditions of the study design.

Adult↗