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Biomedical subjects

H Pedersen

Publications and source records attributed to H Pedersen.

At least 109 records · Page 6Linked to original sources
PubMed1988

Does gestational age affect the pharmacokinetics and pharmacodynamics of lidocaine in mother and fetus?

The pharmacokinetics and pharmacodynamics of lidocaine were studied in nine chronically prepared pregnant ewes and their fetuses at a mean ( +/- SE) gestation of 119 +/- 1.0 days, and the results were compared to the data previously published for ten animals at 138 +/- 1.2 days of gestation (term 148 days). Lidocaine was infused intravenously to the mother at a constant rate of 0.1 mg.kg-1.min-1 over a period of 180 min, in order to reach a steady-state maternal plasma lidocaine concentration of approximately 2 micrograms/ml. Maternal and fetal blood samples and maternal urine were collected at intervals throughout the infusion for determination of pH, blood gases, and lidocaine concentrations. Maternal and fetal heart rate, blood pressure, and intraamniotic pressure were continuously recorded. Fetal cardiac output and organ blood flow were determined before and at the end of lidocaine infusion using radionuclide-labeled microspheres. Lidocaine tissue concentrations were determined in several maternal and fetal organs excised at the end of infusion. In both groups, the steady-state plasma concentrations of lidocaine were similar; namely, 2.3 +/- 0.17 and 2.1 +/- 0.21 micrograms/ml in preterm and term ewes, respectively. There were also no significant differences in steady-state plasma drug concentrations in preterm and term fetuses (1.3 +/- 0.11 and 1.2 +/- 0.15 micrograms/ml). The mean fetal maternal concentration ratios (F/M) were the same; namely, 0.6. Maternal urinary excretion of lidocaine correlated with urine pH, being greater in the more acid urine. Tissue uptake of drug tended to be higher in the preterm than term mothers, but only significantly so in the brain and adrenals.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Obstetrical↗
PubMed1988

Ultrasound-guided percutaneous nephrostomy in the treatment of advanced gynecologic malignancy.

Adjuvant to cancer therapy, 35 percutaneous ultrasound-guided nephrostomies have been applied in 21 patients with ureteral occlusions or lesions secondary to advanced gynecologic malignancies. Application of the catheters was uncomplicated. Dislodgement of the catheters was the major problem with this technique, occurring in 9 cases. There were no serious complications. In 14 patients, normal ureteral function was restored after the cancer therapy, 2 had to be nephrectomized, and in 5 patients the nephrostomies had to remain permanently. It is concluded that nephrostomy is a useful tool in the management of advanced gynecologic malignancies in patients who have a prospect of cure or a period of meaningful tumor regression.

Female↗
PubMed1988

Sperm chromatin heterogeneity as an infertility factor.

Semen samples from husbands with a history of unexplained infertility (n = 33), of women with habitual abortion (n = 36), or normal fertile donors (n = 20) were subjected to conventional semen analysis (SA), Acridine orange test (AOT), and zona-free hamster egg penetration test (HEPT). The three tests operate independently. The most discriminatory test was AOT (p = 0.0001) followed by HEPT (p = 0.019). The frequency of sperm chromatin heterogeneity as detected by AOT red fluorescence was highest in habitual abortion (39.4%), followed by unexplained infertility (16.4%), and, last, donors (9.4%). However the percentage of penetration was highest in habitual abortion (50.7%), followed by donors (43.1%), and least in unexplained infertility (33.9%). Conventional semen parameters (sperm density, motility, abnormality, and vitality) were the least to discriminate between the three groups. The presence of abnormal sperm chromatin may lead to infertility as a result of early pregnancy loss.

Acridine Orange↗
PubMed1988

Acridine orange fluorescence as male fertility test.

Acridine orange fluorescence, semen analysis, and zona-free hamster egg penetration tests were performed on 100 consecutive semen samples. No significant correlation was detected between sperm motility and red fluorescence. However, abnormal sperm morphology correlated significantly with red fluorescence (p less than or equal to 0.001) and fluorescence index (p less than or equal to 0.001). Presence of a high percentage of red fluorescing sperm did not prevent their penetration of zona-free hamster egg, indicating that the presence of abnormal DNA had no effect on the sperm fertility. The significance of acridine orange fluorescence male fertility test requires further elucidation.

Acridine Orange↗
PubMed1988

Pharmacokinetics of lidocaine in nonpregnant and pregnant ewes.

The pharmacokinetics of lidocaine were studied in nonpregnant and pregnant ewes. The maternal femoral vessels were cannulated and, on the day of study, the urinary bladder was catheterized. Lidocaine HCl, 4-5 mg/kg, was administered by IV injection over 60 seconds. Serial samples of arterial blood and urine were collected over 4 hours, and drug concentrations were determined using a gas chromatographic technique. The volume of the central compartment was greater in pregnant than in nonpregnant ewes (1.51 +/- 0.20 vs. 0.96 +/- 0.16 L/kg) as was the volume of distribution at steady state (Vdss): 3.24 +/- 0.40 vs. 1.88 +/- 0.32 L/kg. The volume of distribution during the terminal exponential phase of drug elimination (Vd beta) and total clearance of lidocaine (Cl) were also higher in pregnant animals: 4.17 +/- 0.50 L/kg and 99.6 +/- 8.5 ml.min-1.kg-1, respectively; compared to 2.46 +/- 0.48 L/kg and 44.1 +/- 6.5 ml.min-1.kg-1, in nonpregnant ewes. However, the balance between these changes in Vd beta and Cl did not result in a significant difference in the elimination half-life of lidocaine (38.1 +/- 2.1 minutes in nonpregnant and 31.9 +/- 3.0 minutes in pregnant ewes). If these data are applicable to humans, the risk of drug accumulation after repeated administration of lidocaine is no greater in pregnant than in nonpregnant patients.

Animals↗
PubMed1987

Effect of lidocaine on the asphyxial responses in the mature fetal lamb.

The effects of lidocaine on the fetal circulatory responses to asphyxia were evaluated in chronically instrumented pregnant sheep. Twenty-six preparations were studied. Animals were assigned to one of three groups. The animals in group I (N = 10) did not have umbilical cord occluders placed. Lidocaine at 0.1 mg X kg-1 X min-1 was infused to the mother for 180 min. The animals in group II (N = 11) had an umbilical cord occluder, which was inflated to induce fetal asphyxia (PaO2 15 mmHg) for 90 min. Occlusion was then maintained for an additional 180 min while lidocaine at 0.1 mg X kg-1 X min-1 was infused. The animals in group III (N = 5) also had an umbilical cord occluder inflated for 90 min. While occlusion was maintained for an additional 180 min, saline was infused, in place of lidocaine. The infusion rate of lidocaine of 0.1 mg X kg-1 X min-1 over 180 min resulted in a steady-state arterial lidocaine blood concentration in the mother of approximately 2.15 micrograms/ml. Fetal circulatory responses to asphyxia were evaluated before and after maternal infusion of lidocaine or normal saline. Measurements included heart rate, blood pressure, arterial pH, and blood gases. Cardiac output and organ blood flow were determined using the radio-labelled microsphere technique. In general, arterial and tissue lidocaine concentrations in asphyxiated fetuses were higher than those in the nonasphyxiated ones, the differences being significant in the brain, heart, liver, and adrenal glands.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Epidural↗
PubMed1987

Ultrastructure of spermatozoa with abnormal morphology and predominantly single-stranded DNA.

Semen samples from two infertile men showed normal numbers of cells, but the majority of the spermatozoa were abnormal in shape and had very poor motility. The majority of the spermatozoa showed red fluorescence when stained with acridine orange, indicating the presence of single-stranded DNA. At the ultrastructural level the chromatin was decondensed to various degrees. The acrosomes were either lacking or highly abnormal in appearance. Abnormal tail elements were liberally scattered all over in the abnormal cells. Based on these findings and previous reports, it is suggested that certain infections and exposure to various toxic substances can result in such changes.

Acrosome↗
PubMed1987

Combined modality therapy for oesophageal squamous cell carcinoma.

In a prospective study 110 patients with histologically confirmed oesophageal squamous cell carcinoma received radiation therapy combined with bleomycin or a retinoid. Surgery was initially intended in 34 patients and was later on undertaken in 25 of them after irradiation; in 12 patients the operation was regarded as radical and in 4 of these no remaining tumour was found at operation. The survival rate was significantly higher in the operated than in the non-operated patients which entirely depended on the radically operated ones. Survivals up to more than 71 months were observed and the best results were apparently obtained in patients who became tumour-free after preoperative therapy. It is concluded, that the combined treatment was curative only in a few cases and that future studies should be focused on more intensive preoperative treatment and more critical selection of patients for surgery.

Adult↗
PubMed1987

Oral ftorafur versus intravenous 5-fluorouracil. A comparative study in patients with colorectal cancer.

The toxicities of oral Ftorafur (1 g/m2/day 1-21) and intravenous 5-fluorouracil (5-FU) (500 mg/m2/day 1-5) were compared in a prospective randomized study in patients with colorectal cancer. The treatment courses were repeated every 6th week. Leucopenia was more common after 5-FU. Leucocyte nadir in connection with first treatment cycle was on average seen on day 15 in patients receiving 5-FU and on day 28 in patients receiving Ftorafur. Significantly more patients on 5-FU developed stomatitis. There was no difference in the number of patients with diarrhea or nausea/vomiting. Median survival and response rates were not significantly different after the two treatment schedules.

Administration, Oral↗
PubMed1987

The substrate specificity of the enzyme amyloglucosidase (AMG). Part I. Deoxy derivatives.

The eight possible monodeoxy derivatives of methyl beta-maltoside and two bisdeoxy derivatives have been synthesized. The unprotected glycosides have all been investigated by NMR (1H and 13C) spectroscopy in order to confirm their structures and to obtain supporting information about their preferred solution conformations. The compounds have all been tested as substrates toward the hydrolase, amyloglucosidase (AMG) and it has been demonstrated that three hydroxy groups (3, 4' and 6') are essential for the compounds to act as substrate for the enzyme. The kinetic parameters KM (Michaelis-Menten constant) and VM (maximum rate for the reaction) have been determined using 1H NMR spectroscopy at 500 MHz.

Glucan 1,4-alpha-Glucosidase↗
PubMed1986

Carcinoembryonic antigen (CEA) and alkaline phosphatase in progressive colorectal cancer with special reference to patient survival.

The prognostic value of serial CEA tests was evaluated in 175 consecutive patients with progressive colorectal cancer who subsequently died of their disease. The upper normal plasma CEA limit was determined to be 8 ng/ml from serial CEA determinations in 31 patients radically operated on for colorectal cancer and observed in median 40 months without evidence of recurrence. A CEA value of greater than 8 ng/ml was highly suggestive of residual disease or recurrence, even when no clinical evidence was present. Approximately 90% of the patients dying from colorectal cancer showed an increase in CEA to greater than 8 ng/ml during the course of the disease. In 63% of the patients CEA increase preceded clinical progression or relapse, with a median time period of 4 months. Sixty-eight per cent of the patients had rising CEA values over an extended time period of many months, 14% had a preterminal increase, 13% had constantly normal and 5% constantly elevated CEA. As 6/9 patients developed a drop in CEA in relation to initiation of chemotherapy without clinical response, it is concluded that CEA is not a reliable indicator of clinical response to chemotherapy. Patients with liver metastases had higher CEA and alkaline phosphatase levels than patients with only localized disease. However, no good statistical correlation between CEA and serum alkaline phosphatase was found in patients with liver metastases (coefficient of correlation r = 0.35). An increase in CEA from normal to above 8 ng/ml predicted a decrease in survival time of median 60% counted from the time of diagnosis. The numerical CEA value was predictive of shortening of survival only when greater than 3000 ng/ml. Such high values were observed only in a minority of the patients (12%). Greater than 1000 U/l (27% of the patients) alkaline phosphatase predicted an extremely poor prognosis, with a median survival of 1 month (range 0.5-4 months). It is concluded that a rise in CEA to greater than 8 ng/ml indicates with high degree of certainty relapse or disease progression in colorectal cancer patients. CEA is not a reliable indicator of clinical response to chemotherapy, and an increase in the CEA level is of little prognostic value concerning survival. Alkaline phosphatase seems to be a more valuable predictor of a worsening of prognosis.

Alkaline Phosphatase↗
PubMed1986

Spontaneous remission of cerebral palsy.

Among 2100 children with a diagnosis of cerebral palsy (CP) twenty carried the diagnosis: Previous CP, now normalized. Seventeen patients could be traced and were reevaluated. Cerebral palsy was diagnosed in these seventeen children (ten boys, seven girls) between the ages of three months and three years (average eleven months). They were found to be normal when reexamined between the ages of one year and five years (average two years two months). Two patients had tetraplegia, three diplegia, nine paraplegia ("paraplegia" were cases of diplegia with minimal affection of the upper limbs - now called "diplegia type I"), and one hemiplegia. One patient had atactic diplegia, and one was athetotic. The records of these seventeen patients were evaluated with respect to aetiology and symptomatology. Upon reexamination seven patients were found to be completely normal. Five patients had no motor symptoms but showed signs of specific neuropsychological difficulties. Two patients were intellectually retarded without motor symptoms. One showed signs of neuropathy, and one had fetal alcohol syndrome. Signs consistent with CP could be demonstrated in one patient only. This study shows that signs of CP may in rare cases disappear altogether.

Brain↗