Lack of enterohepatic circulation of intact biliary phosphatidylcholine in the rat

The bile phosphatidylcholine was radioactively labelled by intraperitoneal or intravenous injection of [3H]- or [14C]-palmitic acid into bile fistula rats. The radioactive bile was infused intraduodenally into other bile fistula rats. On an average, only 1.0% of the infused radioactive phosphatidylcholine fatty acid reappeared in bile phosphatidylcholine, whereas about 68% of simultaneously infused [3H]-taurocholate was recovered over the same period of time (6 hours). There is thus no significant enterohepatic circulation of intact biliary phosphatidylcholine.

Radiation response modified by degradable starch microspheres. Experiments on the rat's foot

Skin reaction in the rat's foot was used as an experimental method to evaluate the protective potential of profound temporary hypoxia against roentgen radiation produced by a linear accelerator. Hypoxia was induced by intraarterial injection of degradable starch microspheres. The irradiation dose needed to evoke a certain reaction in the hypoxic feet was 2.0 times the dose giving the same reaction in a control group. The results point towards a new technique of inducing local hypoxia in healthy tissues which need to be protected in an irradiation field.

Comparison of extra-amniotic instillation of rivanol and PGF2alpha either separately or in combination followed by oxytocin for second trimester abortion

Second trimester abortion was induced in 92 women by extra-amniotic instillation of Rivanol and/or PGF2alpha followed by intravenous oxytocin after 24 hours. All instillations were made via a catheter with a balloon filled with 30 ml and left in place until abortion, but never for more than 24 hours. Induction was started by Rivanol alone (n = 23), PGF2alpha alone (n = 23), Rivanol combined with PGF2alpha (n = 23), or Rivanol combined with half dose PGF2alpha (n = 23) and the patients were allotted to the different groups in a random manner. The Rivanol solution was instilled as a single dose but PGF2alpha was instilled every 2nd hour for 24 hours. The mean induction-abortion time was similar in all 4 groups but a number of patients given PGF2alpha alone or in combination with Rivanol aborted earlier than patients induced by Rivanol alone, during the period before intravenous oxytocin was administered. Gastrointestinal side effects were equally common after Rivanol as after PGF2alpha. With the methods and doses used in the present investigation PGF2alpha alone or combined with Rivanol with subsequent oxytocin had no over-all advantage over Rivanol.

Effect on blood coagulation and fibrinolysis in women using norethisterone or a combination of ethinyloestradiol and quingestianol

Oral contraceptives of the combined type and contraceptives containing only progestagen were studied for their effect on blood coagulation and fibrinolysis. Several blood parameters were determined in 13 women before and during the 3rd month of use of either 0.3 mg norethisterone alone or 0.05 mg ethinyloestradiol combined with 0.5 mg quingestianol. Blood samples were obtained on days 2--4, 9--11, 16--18 and 23--25 of the menstrual cycle. Except on days 16--18, a significantly increased fibrinolytic activity and a significantly increased variation in plasminogen were observed in women using the combined type of contraceptives, but not in the women using contraceptives containing only norethisterone. The other variables studied were not significantly changed, which might be due to the doses and types of progestagens used in the present series.

Caesarean section. A clinical study with special reference to the increasing section rate

At Huddinge University Hospital 539 Caesarean Sections (C.S.) were made among 8415 deliveries from October 1972 to June 1976, corresponding to an over all C.S. rate of 6.4%. Over these years the rate has increased from 3.5% in 1972 to 9.7% in 1976. The main increase was due to a higher incidence of abdominal deliveries in cases of imminent fetal asphyxia. The maternal complication rate and the neonatal morbidity rate were both 6.5 times higher and the neonatal mortality rate was 4.1 times higher in emergency than in elective surgery. There was neither any mortality nor any morbidity in infants delivered by elective C.S. from healthy mothers at term.

Oxyphenbutazone--an adjuvant to be used in prevention of adhesions in operations for fertility

A laparotomy was performed in 40 rats and the cecum was subjected to a standardized trauma. Half the rats were treated with oxyphenbutazone in a dose of 40 mg/kg body weight daily for 14 days. The remaining 20 rats served as controls. All of the rats were killed 2 weeks after the laparotomy, and the number of intraperitoneal adhesions was recorded. There were significantly (P less than 0.001) fewer rats with adhesions in the group treated with oxyphenbutazone than in the control group.

The concentration of copper in human uterine secretion during four years after insertion of a copper-containing intrauterine device

The contraceptive action of a copper-containing intrauterine device (Cu IUD) is mainly associated with the copper ions released, thus its efficiency varies with the surface area of the copper wire. It is of considerable clinical interest to know the usful life-span of a Cu IUD. Therefore, the concentration of copper in the uterine secretion of women wearing a Cu-7 IUD (Gravigard) with a surface area of the copper wire of 200 sq mm was determined by atomic absorption spectroscopy. No decrease in the concentrations of copper was found in a series of women followed for 4 years after the insertion of a Cu IUD.

Intracerebroventricular glycerol: a potent inhibitor of ADH-release and thirst

Infusions of isotonic or hypertonic (0.3 or 0.5 M) glycerol into the lateral cerebral ventricle (60 min, 0.02 ml/min) of non-hydrated goats invariably induced a conspicuous and sustained water diuresis. Corresponding infusions of 0.3 M glycerol/0.16 M NaCl were almost equally efficient in this respect. A more short-lasting and less pronounced water diuresis was obtained in response to equivalent infusions of pure d-glucose, and the response to 0.3 M glucose/0.16 M NaCl was variable. Intravenous injections of vasopressin blocked the glucose-induced diuresis, but only postponed the glycerol-induced diuresis. Intracerebroventricular (IVT) infusions of 0.5 M glycerol caused a sustained, complete inhibition of the urge to drink in the 48 h dehydrated goat, whereas IVT glucose only attenuated dehydrative drinking. Twenty min after the infusions of glycerol the CSF [Na+] in the lateral ventricle was about 15% below normal. About 10% reduction of CSF [Na+] was obtained 20 min after the IVT infusion of glycerol/NaCl. The corresponding infusion of pure d-glucose reduced the CSF [Na+] by less than 5%. The glycerol and glycerol/NaCl infusions caused a moderate reduction of renal Na+ + K+ excretion. The possibility is discussed that the observed effects of IVT glycerol is a manifestation of its efficiency to inhibit choroidal and/or juxtaventricular (Na+-K+)-ATPase activity.

Accumulation of 14C-lidocaine in the inner ear. Preliminary clinical experience utilizing intravenous lidocaine in the treatment of severe tinnitus

Clinical experience has demonstrated that intravenously administered local anaesthetics have a mitigating effect on severe tinnitus. In an attempt to gain some insight into the mechanism of this effect, autoradiography of the inner ear of young pigmented rats was performed after intravenous injection of 14C-lidocaine. Some accumulation of lidocaine was found in the modiolus, but almost none in the stria vascularis. A large accumulation was observed in other melanincontaining tissues, such as the hair follicles and uvea. The in vitro accumulation of 14C-labelled lidocaine adsorbed on melanin granules was low (12%) as compared with that of other drugs, such as kanamycin (89%) and chloroquine (85%). These autoradiographic results indicate that lidocaine has an effect upon the inner ear, in addition to its previously demonstrated effect on the CNS.

The influence of copper on the in vitro motility of the human Fallopian tube

Experiments were designed to examine whether one contraceptive action of the copper intrauterine contraceptive devices (Cu-IUD's) could be associated with an influence on the smooth muscle activity of the Fallopian tube. Sections of the isthmic portion of human oviducts were removed during operation. Preparations from the circular muscle layer were mounted for isometric recording of contractile activity. Subsequently, spontaneous rhythmic contractions appeared within one to five minutes after the preparation procedure was completed. Transmural nerve stimulation or addition of norepinephrine or prostaglandin F2alpha to the Tris buffer medium caused an increase in tone and frequency. Addition of CuCl2 caused a concentration-dependent increase in frequency and a concomitant decrease in amplitude. High concentrations of CuCl2 produced a marked initial increase in frequency, but the rhythmic activity was soon abolished. Metallic copper in the incubation medium caused the same qualitative effects on the smooth muscle preparation as CuCl2. Influences of copper on contractions of rat portal vein preparations were studied in the same way, and similar effects were found. The copper concentration of the secretion in the Fallopian tube was measured by atomic absorption in seven patients wearing CU-IUD's until operation. The levels found were of the same order of magnitude as the concentration of free copper ions which in vitro caused effects on the smooth muscle. It is concluded that copper can affect smooth muscle activity. An influence of copper on the motility of the human oviduct has to be considered as a possible factor contributing to the contraceptive action of the Cu-IUD.

Active site of ribonucleoside diphosphate reductase from Escherichia coli. Inactivation of the enzyme by 2'-substituted ribonucleoside diphosphates

Ribonucleoside diphosphate reductase is an allosteric enzyme consisting of two nonidentical subunits, proteins B1 and B2. B1 contains dithiols which participate in the oxidation-reduction reactions of electron transport, while B2 contains a free radical essential for activity. Ribonucleoside diphosphates are bound to B1 but not to B2. Addition of 2'-deoxy-2'-chloro ribonucleoside diphosphates to ribonucleotide reductase irreversibly inactivates B1 without affecting B2. The reaction is specific since (a) it requires the presence of active B2, (b) it is controlled by allosteric effectors, (c) B1 is protected against inactivation by the normal substrates, and (d) the chloro-substituted nucleoside monophosphates have no effect. The inactivation of B1 is caused by a modification of the oxidation-reduction dithiols. The chloro derivatives decompose into free base, chloride ion, and 2-deoxyribose 5-diphosphate as a consequence of reaction with the enzyme. 2'-Deoxy-2"-azido ribonucleoside diphosphates cause an irreversible inactivation of B2 without affecting B1. The reaction is specific by the above criteria, indicating that the azido derivatives also bind to the active site of the enzyme. On reduction by ribonucleotide reductase, the azido derivatives function as radical scavengers and selectively destroy the free radical of B2, indicating that this radical participates in ribonucleotide reduction directly. On the basis of these results, a model of the active site of ribonucleotide reductase is proposed in which the site is formed from both B1 and B2. In the site the electron-donating oxidation-reduction active dithiols of B1 are in close contact with the free radical of B2. The azido derivative also inactivates the adenosylcobalamin-dependent ribonucleoside triphosphate reductase from Lactobacillus leichmannii and a ribonucleotide reductase preparation from calf thymus, indicating a general involvement of free radical intermediates in enzyme-catalyzed ribonucleotide reduction.

Adipocyte metabolism in endogenous hypertriglyceridemia

In order to define specific metabolic abnormalities of adipose tissue metabolism in endogenous hypertriglyceridemia (EH) patients with this condition were compared with normolipidemic controls matched for body fat and fat cell size. In vitro the enlarged fat cells of EH were found to have an increased basal and noradrenaline-stimulated lipolysis in comparison with cells of the same size from normolipidemic controls. The insulin inhibition of noradrenaline-stimulated lipolysis was blunted. Lipoprotein lipase activity in these cells was clearly depressed. Basal triglyceride synthesis from labeled glucose was low in relation to plasma insulin. The reduction of insulin tolerance in vivo suggested that the depression of plasma glycerol and free fatty acid concentration was small in EH, suggesting that the more detailed findings in vitro were of relevance for in vivo conditions. It was suggested that the hyperinsulinemia and decreased glucose tolerance of EH may well be responsible for some of the aberrations of adipocyte metabolism in EH. The decreased responsiveness of lipolysis to insulin and the low lipoprotein lipase activity are, however, findings not typical for enlarged fat cells exposed chronically to insulin and might be characteristic for the fat cells of EH. It seems of importance to further define the factor(s) responsible for these metabolic aberrations, because the abnormalities of the acipocyte metabolism in EH may well offer a possible explanation to the pathogenesis of that condition.

A modified "soft surface specimen technique" for examination of the inner ear

A new surface preparation method was devised for assessing intracochlear vessels and sensorineurepithelium. The method is a combination of the conventional osmic acid stained surface preparation method and a surface preparation technique with injection of Prussian blue and decalcification of the cochlea. Such a combination preserves most advantages of each and eliminates many of the disadvantages. To preserve the delicate sensory and nervous structures we examined variations of the preparation, paying particular attention to fixation, staining, and decalcification procedures and solutions. Varying the preparation had a less marked effect on external wall structures than on the basilar membrane; the primary changes consisted of variation in staining contrast. The method proved useful for demonstrating the normal anatomy and pathological changes in cochlear vasculature and in sensorineural and supporting structures of the labyrinth in light and phase contrast microscopy at moderate magnifications.

A study of different methods for the assay of lipoprotein lipase activity in human adipose tissue

A method for the assay of lipoprotein lipase activity (LPLA) in heparin eluates of needle biopsies of adipose tissue is presented. A serum activated phosphatidestabilized emulsion of labelled triolein has been used as substrate. This method and a previously described method using heparin eluates as enzyme source and a commercial triglyceride emulsion, Ediol, as substrate, showed a high degree of correlation (correlation coefficient = 0.94) when parallel determinations were performed on biopsies from 16 subjects. Further, the Ediol method similarly correlated well with a method for LPLA assay, previously described by Nilsson-Ehle and Belfrage, on acetone-ether extracts of adipose tissue (correlation coefficient = 0.88; 19 subjects).

Effect of an energy-reduced dietary regimen in relation to adipose tissue cellularity in obese women

Twenty-eight obese women were divided after arbitrary statistical guidelines obtained from control studies into hyperplastic (increase in fat cell number) (n equal to 10), hypertrophic obesity (increase in average fat cell size) (n equal to 11), and a remaining group (n equal to 7). All these subjects were treated on an outpatient basis with an energy-reduced diet (1,100 kcal/day) until weight decrease failure occurred. The fat cells of the femoral and gluteal regions were larger than in the abdominal region in hypertrophic obese subjects. This regional fat cell size profile was found also in middle-aged and young controls. The hyperplastic obese subjects on the other hand had larger fat cells in the abdominal site. At failure of therapy enlarged fat cells in either of the two obesity groups had decreased to the size of fat cells of controls. Fat cell number remained unchanged. Thus the hypertrophic obese patients ended up with a normal body fat while hyperplastic obese subjects had a pronounced remaining obesity. The results suggest that when the fat cell size in different regions of an individual are known, as well as the total fat cell number, the success of an energy-reduced dietary regimen might be approximately predicted both in terms of remaining total body fat and in regional fat depot decrease.

Influence of absorbed dose and field size on the geometry of the radiation-surgical brain lesion

Specimens from a number of patients locally irradiated in the thalamus for intractable pain with a multiple gamma beam technique have been examined. The geometry of well circumscribed necrotic lesions was ascertained. No correlation was seen between the dimensions of the lesions and the size of the field, 3 mm X 5 mm or 3 mm X 7 mm, within the clinically useful dose range, 16 to 25 krad.