Selenium and vitamin E treatment of Duchenne muscular dystrophy: no effect on muscle function

16 boys with Duchenne muscular dystrophy (DMD) were treated with sodium selenite and vitamin E for one year. One group of patients (10 boys) was examined using a battery of tests to assess muscular strength and function and cardiopulmonary function, and by CT scanning of 2 muscle groups over the 4 years prior to treatment. Six boys with DMD entered the study when the treatment was begun. Tests of muscular force and function, cardiopulmonary tests and CT-scanning were performed at the onset of treatment, and after 6 and 12 months. No beneficial effect on either muscular force or function was found during the treatment period. It is concluded that selenium and vitamin E in high doses do not improve muscle function in DMD.

Benzene metabolism by ethanol-, acetone-, and benzene-inducible cytochrome P-450 (IIE1) in rat and rabbit liver microsomes

Ethanol is known to exert a synergistic effect on the toxicity of benzene. In the present investigation it was found that benzene was metabolized at a rate 20-65-fold higher in liver microsomes from ethanol- or acetone-treated rats than in microsomes from control animals. One high affinity site [Km = 19 +/- 5 (SD) microM] and one low affinity site [Km = 0.3 +/- 0.1 mM] for benzene metabolism were present in microsomes of acetone-treated rats, and similar sites were seen in microsomes from control or ethanol-treated rats. Treatment of the animals with either ethanol or acetone mainly influenced the Vmax values for benzene metabolism. Also benzene treatment of rats caused an increased rate of microsomal benzene metabolism. The hepatic microsomal NADPH-dependent metabolism of benzene was inhibited by compounds known to interact with the ethanol-inducible form of P-450 such as imidazole, ethanol, aniline, and acetone but was unaffected by addition of metyrapone. Anti-IgG against ethanol-inducible cytochrome P-450 from rat (P-450j) or rabbit liver (P-450 LMeb) inhibited the microsomal benzene metabolism effectively in rat or rabbit liver microsomes, respectively, whereas preimmune IgG was without effect. The level of rat ethanol-inducible P-450 (P-450j) was induced to an extent similar to that for the microsomal benzene metabolism, by either benzene, acetone, or ethanol. The data indicate that benzene is metabolized mainly by the ethanol-inducible P-450 form in liver microsomes and that the induction of this isozyme by ethanol can provide an explanation for the synergistic action of ethanol on benzene toxicity.

Significance of "ultra-early" rebleeding in subarachnoid hemorrhage

Knowledge of the local incidence of aneurysm rupture permits the conclusion that almost every patient in the population of 933,800 persons served by the authors' institution who was stricken by this catastrophe and survived long enough to be transported was treated at this center (121 patients during 34 months). Of these, 9.1% were admitted late (greater than 72 hours after subarachnoid hemorrhage (SAH]; of the remaining cases, 94.5% were seen within 24 hours and 50% within 6 hours post-SAH. Of the 121 patients, 10% were neurologically devastated on arrival, a late operation was planned for 19%, and the earliest possible surgery and nimodipine administration was selected for 71%. In this latter group, 50% of the operations were begun within 24 hours and 76% within 48 hours post-SAH. Sixty percent of all mortality and morbidity could be linked to the initial aneurysm bleed. The remaining 40% could be ascribed to potentially avoidable causes of unfavorable outcome. No less than 9.6% of all patients admitted within 24 hours after SAH suffered from "ultra-early" rebleeding during transportation or preparation for operation. The mortality rate from such rebleeding was 7.4%, compared with the 9.1% combined mortality rate from complications and late ischemia.

Ethanol-, fasting-, and acetone-inducible cytochromes P-450 in rat liver: regulation and characteristics of enzymes belonging to the IIB and IIE gene subfamilies

Two major forms of hepatic microsomal cytochrome P-450 were purified from starved and acetone-treated rats. On the basis of amino acid sequence analysis, they were identified as P-450j and P-450b. Ethanol or acetone treatment of rats caused a 9-fold increase in the amount of P-450j in liver microsomes accompanied by similar increases in the rate of NADPH-dependent metabolism of carbon tetrachloride, acetone, and benzene. Immunological experiments indicated that P-450j constitutes the major catalyst of the microsomal metabolism of the latter agents and contributes by about 50% to microsomal P-450-dependent ethanol oxidation under the conditions used. The P-450j-dependent catalytic activities had a high rate of turnover. In contrast, this was not the case for the immunodetectable P-450j, indicating the occurrence of inactive forms of this protein in microsomes. Starvation or ethanol or acetone treatment caused 10-30-fold increases in the amount of both mRNA and apoprotein of P-450b,e compared to control. Run-on experiments and the concomitant increases of the P-450b,e gene products at the mRNA and protein levels indicated the appearance of mainly a transcriptional activation by acetone, ethanol, or starvation. Fasting exerted, in addition, a pronounced synergistic effect on acetone-dependent induction of P-450b,e mRNA (3-fold), apo-P-450b,e (4.3-fold), P-450j mRNA (2-fold), and apo-P-450j (2-fold). No increase of mRNA coding for P-450j, compared to control, was seen after acetone or ethanol treatment alone. The results indicate that effects of ethanol, acetone, and/or starvation on drug and xenobiotic metabolism are caused by the induction of P-450 forms belonging to at least two gene subfamilies.

Ligand-dependent maintenance of ethanol-inducible cytochrome P-450 in primary rat hepatocyte cell cultures

Administration of ethanol, dimethylsulphoxide, 2-propanol or imidazole to rats caused 2-7-fold increases in the level of hepatic ethanol-inducible cytochrome P-450 (P-450j), without any concomitant enhancement of corresponding mRNA. All the compounds were able to stabilize P-450j in hepatocyte cultures for at least three days, whereas P-450j mRNA rapidly disappeared from the cultures. A correlation was reached between the concentration of Me2SO, ethanol and 2-propanol necessary to maintain P-450j in the cell cultures and their binding affinities to the enzyme. It is suggested that the ligand-bound form of P-450j in the hepatocytes is protected from degradation.

Effect of long-term isoproterenol treatment on caries development in the rat using a low-cariogenic model

Forty-eight Sprague-Dawley rats were divided into four groups. Two groups were injected daily with saline (groups 1 and 2) and two groups with isoproterenol (0.5 mg/kg body weight, groups 3 and 4) beginning at the age of 21 days. Groups 1 and 3 were each day fed nine subsequent sucrose-containing meals followed by eight starch-containing meals. Groups 2 and 4 were fed alternating sugar- or starch-containing meals, totally 17 meals per day. The animals were sacrificed after 14 weeks. At the end of the experiment, the animals in the isoproterenol groups had higher body weights. Caries development increased significantly after isoproterenol treatment. The diet regimen with alternating sugar- or starch-containing meals increased caries development, particularly in combination with isoproterenol treatment. Using low cariogenic conditions, we found that an unspecific beta-agonist (isoproterenol), given posteruptively at a low dose, enhances caries development.

Saliva composition and caries development during protein deficiency and beta-receptor stimulation or inhibition

We tested the hypothesis that a low protein diet (5%) would change the conditions for synthesis and release of protein from the salivary secretory cells and increase caries development. In addition, we tested whether the simultaneous use of a beta-adrenoceptor agonist or antagonist had an additive effect. After an experimental period of nine weeks the animals fed the 5% protein diet had lower body weights, saliva secretion rates and total protein secreted per minute than a control group fed a 20% protein diet. There were greater numbers of cariogenic streptococci on the teeth and the caries scores were higher in the rats fed the low protein diet than in the rats in the control group. The beta-receptor agonist, isoproterenol, given to rats fed the 20% protein diet, caused a reduction in protein concentration and amylase activity in saliva and a slight increase in caries development. Propranolol had no effect on either saliva composition or caries development.

Per-operative angiography--a useful tool in cerebral aneurysm surgery?

The value of per-operative angiography in elective surgery for aneurysms in the anterior cerebral circulation is evaluated. A progressive decrease in the number of difficulties was observed and was correlated with the introduction and refinements of microsurgery. From 1980-1983 approximately 5-8% of the angiograms revealed technical details which, as elucidated in the Discussion, did not always seem to require surgical correction. No case of an aneurysm neck remaining patent was encountered during this period. Similarly, main arterial branches were found to be occluded on only a few occasions, whereas significant unoccluded remnants of the base of the aneurysm occurred in roughly 5% of the cases despite modern microsurgery. It is felt by the authors that angiographic control of the operative result is no longer required in every aneurysm case because of the options for adequate visual control offered by the microtechnique. With this background it is concluded that, despite the optimal technical conditions available, per-operative angiography cannot be universally recommended in aneurysm surgery because of the inherent complexity of the procedure. Instead, post-operative angiography is more appropriate as a routine procedure for follow-up of a variety of selected cases in which visual control was unsatisfactory.

Restenosis and occlusion after carotid surgery assessed by duplex scanning and digital subtraction angiography

In a study of 140 patients operated upon with 143 carotid endarterectomies (mean follow-up time 5.2 +/- 2.3 years, range 1 month - 9.3 years), vessel morphology was examined with duplex scanning in 113 patients and with digital subtraction angiography (DSA) in 82 patients. The operative mortality was 1.4%; persisting stroke morbidity 3.6% and the combined operative mortality/morbidity 5%. During the follow-up time a further 20 patients (14.5%) died, 13 had new strokes and 14 new TIAs. By life table analysis, the annual rate of stroke including the operative period was 2.7% (1.7% on the operated side and 1.0% on the non-operated side). Fourteen new occlusions (12%) of the operated carotid artery was found and restenosis (greater than 50%) in 13 patients (11.2%). Progression of the atherosclerotic disease in the contralateral non-operated carotid artery was found in 41 patients (37%) including 3 new occlusions. Agreement DSA/duplex was 88% on the operated side and 92% on the non-operated side. New strokes or TIAs on the operated side were more common in patients with occlusions or restenosis (p less than 0.05), whereas no symptoms were referable to occlusions on the non-operated side. Risk factor analysis revealed an increased risk of atherosclerotic progression on the non-operated side in smokers and those with two or more risk factors. The risk of restenosis in the operated carotid artery was higher in females (p less than 0.025).

Hydroxylation of acetone by ethanol- and acetone-inducible cytochrome P-450 in liver microsomes and reconstituted membranes

Acetone oxidation in rat liver microsomes was induced 5- or 8-fold by the treatment of the animals with ethanol or acetone, respectively. The apparent Km of the reaction was 0.9 mM, a value lower than the concentration reported for plasma acetone under starvation conditions. The major acetone metabolite was identified as acetol by GC-MS. Acetone oxidation in microsomes was inhibited by typical P-450 inhibitors as well as by compounds (e.g. imidazole) known to interact with the ethanol-inducible P-450 form. Antibodies against this P-450 isozyme were inhibitory for the reaction in rabbit liver microsomes and this isozyme was the only one that showed acetone hydroxylation activity in reconstituted membranes. Imidazole inhibited the conversion of [14C]acetone into low-Mr compounds (e.g. glucose) in vivo. It is suggested that the ethanol- and acetone-inducible P-450 make use of acetone as an endogenous substrate in the utilization of the compound for, e.g. glucose production under conditions of starvation and diabetic ketoacidosis.

Prospective evaluation of the accuracy of duplex scanning with spectral analysis in carotid artery disease

Prospective evaluation of duplex scanning of the carotid vessels was performed over a 2-year period in 125 consecutive patients (249 vessels) with transient ischaemic attacks or minor stroke. Defining disease as a stenosis of greater than 15% reduction of the vessel diameter, with subgroups of 16-49% stenosis, 50-99% stenosis and occlusion, the sensitivity obtained was 96%, specificity 93% and accuracy 94%. With the use of linear multiregression analyses further subgrouping into 50-75% and 76-99% stenosis was performed. The best predictive variables were, in decreasing order, peak systolic velocity, late diastolic velocity and the difference between peak systolic and late diastolic velocity in the internal carotid artery. The additional periorbital Doppler examination caused a slight improvement in determination coefficient and diagnostic accuracy.

Duplex scanning and periorbital pulsed Doppler in the diagnosis of external carotid artery disease: analysis of causes of error

The external carotid arteries (ECA) were examined by duplex scanning in 123 consecutive patients with transient ischaemic attacks (TIA) and minor stroke. Two occlusions and five out of six high grade stenosis were correctly classified, yielding a sensitivity of 88% defining disease as stenosis greater than 50. Specificity was 94% and accuracy was 93%. Nine low grade stenosis (less than 50%) and six normal vessels were judged as high grade stenosis. A possible cause of this overestimation was a compensatory flow increase in the ECA caused by an occlusion or high grade stenosis in the internal carotid arteries (ICA), either on the same side or bilaterally. This was supported by the finding of a significantly (P less than 0.05) higher retrograde flow velocity in the ipsilateral supratrochlear arteries (STA) in patients with high ECA flow velocity, as compared to those with normal ECA flow. Thus in the evaluation of a possible ECA stenosis, the condition of the ICA should be considered in order to avoid overestimation of ECA lesions. The additional examination of flow direction and velocity in STA gives an indication as to whether or not an ECA stenosis might be present.

Carbon tetrachloride-induced lipid peroxidation dependent on an ethanol-inducible form of rabbit liver microsomal cytochrome P-450

Treatment of rats with ethanol or rabbits with either imidazole or pyrazole, agents known to induce the ethanol-inducible form of liver microsomal cytochrome P-450 (P-450 LMeb), caused, compared to controls, 3-25-fold enhanced rates of CCl4-dependent lipid peroxidation or chloroform production in isolated liver microsomes. No significant differences were seen when the rate of CCl4-dependent lipid peroxidation was expressed relative to the amount of P-450 LMeb in the various types of microsomal preparations. In reconstituted membranous systems, this type of P-450 was a 100-fold more effective catalyst of CCl4 metabolism than either of the cytochromes P-450 LM2 or P-450 LM4. It is proposed that the induction of this isozyme provides the explanation on a molecular level for the synergism seen of ethanol on CCl4-dependent hepatotoxicity.

The effect of malnutrition on caries development and saliva composition in the rat

The purpose of this study was to investigate the effect in rats of malnutrition on caries development and on some antibacterial substances in saliva. By gastric intubation, two groups of ten rats each were fed a liquid basic diet (100% diet), and two similar groups were fed the basic diet diluted with an equal volume of water to contain 50% of the nutrients of the basic diet (50% diet). One group on undiluted and one group on the diluted basic diet were offered sucrose as a supplement by mouth 17 times daily, using a programmed feeding machine, and the other two groups were offered starch in a similar manner. The extent and depth of the caries lesions were five times greater in the low-nourished (50% diet) sucrose group in comparison with the group given the undiluted diet supplemented with sucrose. The 50% diet group ate more frequently from the offered supplement. The 50% diet induced lower salivary lactoperoxidase activities, and there was an additive effect of starch as supplement. Higher concentrations of sIgA were found in the saliva of animals fed the 50% diet supplemented with sucrose than in those fed sucrose and the 100% diet. Significantly greater levels of sIgA and IgG were found in the saliva from the 50% diet-sucrose group than in the 50% diet-starch group. Plaque scores differed slightly but not significantly between the groups. The starch group receiving 100% diet showed a slightly lower level of S. mutans infection as compared with the 50% diet-starch group; the caries scores in the starch groups did not differ.

Studies of the effect of diet on saliva secretion and caries development: the effect of fasting on saliva composition of female subjects

In the present investigation 11 females of normal constitution were subjected to a standardized fasting diet for 8 days. Three subjects dropped out early during the experimental period. Saliva and blood samples were collected before, during and after the fasting period. Serum analyses were made of some parameters often studied during undernutrition. As expected, values for creatinine and uric acid were increased. Secretion rate, pH, buffer capacity, electrolytes, total protein, carbohydrates, some antibacterial substances, the amount of Streptococcus mutans, total streptococci, and lactobacilli were determined in the saliva samples. The rate of plaque formation was also estimated. The effect of fasting on the measured parameters varied greatly among the individuals. Fasting caused a significant decrease in secretion rate, concentration of phosphate and sialic acid in stimulated whole saliva. There was no significant increase in concentration of any substance measured. The decrease of the ratio of sialic acid to protein indicates a disturbance of glycoprotein synthesis. In resting saliva the activity of a bacteria-aggregating glycoprotein appeared to be unchanged, whereas the decreases in thiocyanate concentration and lysozyme activity were statistically significant. Lactoperoxidase activities did not change significantly. The amount of IgA, IgG, IgM as well as the microbial counts showed no changes. The rate of plaque formation increased during fasting.

Mechanisms of hydroxyl radical formation and ethanol oxidation by ethanol-inducible and other forms of rabbit liver microsomal cytochromes P-450

The hydroxyl radical-mediated oxidation of 5,5-dimethyl-1-pyrroline N-oxide, benzene, ketomethiolbutyric acid, deoxyribose, and ethanol, as well as superoxide anion and hydrogen peroxide formation was quantitated in reconstituted membrane vesicle systems containing purified rabbit liver microsomal NADPH-cytochrome P-450 reductase and cytochromes P-450 LM2, P-450 LMeb , or P-450 LM4, and in vesicle systems devoid of cytochrome P-450. The presence of cytochrome P-450 in the membranes resulted in 4-8-fold higher rates of O-2, H2O2, and hydroxyl radical production, indicating that the oxycytochrome P-450 complex constitutes the major source for superoxide anions liberated in the system, giving as a consequence hydrogen peroxide and also, subsequently, hydroxyl radicals formed in an iron-catalyzed Haber-Weiss reaction. Depletion of contaminating iron in the incubation systems resulted in small or negligible rates of cytochrome P-450-dependent ethanol oxidation. However, small amounts (1 microM) of chelated iron (e.g. Fe3+-EDTA) enhanced ethanol oxidation specifically when membranes containing the ethanol and benzene-inducible form of cytochrome P-450 (cytochrome P-450 LMeb ) were used. Introduction of the Fe-EDTA complex into P-450 LMeb -containing incubation systems caused a decrease in hydrogen peroxide formation and a concomitant 6-fold increase in acetaldehyde production; consequently, the rate of NADPH consumption was not affected. In iron-depleted systems containing cytochrome P-450 LM2 or cytochrome P-450 LMeb , an appropriate stoichiometry was attained between the NADPH consumed and the sum of hydrogen peroxide and acetaldehyde produced. Horseradish peroxidase and scavengers of hydroxyl radicals inhibited the cytochrome P-450 LMeb -dependent ethanol oxidation both in the presence and in the absence of Fe-EDTA. The results are not consistent with a specific mechanism for cytochrome P-450-dependent ethanol oxidation and indicate that hydroxyl radicals, formed in an iron-catalyzed Haber-Weiss reaction and in a Fenton reaction, constitute the active oxygen species. Cytochrome P-450-dependent ethanol oxidation under in vivo conditions would, according to this concept, require the presence of non-heme iron and endogenous iron chelators.

Sexual and contraceptive experience among teenagers in Uppsala

A questionnaire was offered to 181 sixteen-year-old boys (n = 88) and girls (n = 93) in different schools in the city of Uppsala. The questionnaire was introduced to the students by a nurse midwife during a regular lesson and included over 100 questions dealing partly with sexual education, attitudes towards sex and own experience of sex and contraception. Of the girls, 47% and of the boys, 31% answered that they had had intercourse. Twenty-eight per cent of the girls and 21.5% of the boys had had their first intercourse before the age of 15. Contraception was used at the first intercourse by 59% of the girls and by 70% of the boys. At the very first intercourse, the condom was the most commonly used contraceptive method. Increasing sexual experience changed the contraceptive pattern and at their last intercourse 48% of the girls were on the pill and 33% of the boys said that their girl friend was on the pill.

Hydroxyl radical-mediated, cytochrome P-450-dependent metabolic activation of benzene in microsomes and reconstituted enzyme systems from rabbit liver

The mechanism of benzene oxygenation in liver microsomes and in reconstituted enzyme systems from rabbit liver was investigated. It was found that the NADPH-dependent transformation of benzene to water-soluble metabolites and to phenol catalyzed by cytochrome P-450 LM2 in membrane vesicles was inhibited by catalase, horseradish peroxidase, superoxide dismutase, and hydroxyl radical scavengers such as mannitol, dimethyl sulfoxide, and catechol, indicating the participation of hydrogen peroxide, superoxide anions, and hydroxyl radicals in the process. The cytochrome P-450 LM2-dependent, hydroxyl radical-mediated destruction of deoxyribose was inhibited concomitantly to the benzene oxidation. Also the microsomal benzene metabolism, which did not exhibit Michaelis-Menten kinetics, was effectively inhibited by six different hydroxyl radical scavengers. Biphenyl was formed in the reconstituted system, indicating the cytochrome P-450-dependent production of a hydroxycyclohexadienyl radical as a consequence of interactions between hydroxyl radicals and benzene. The formation of benzene metabolites covalently bound to protein was efficiently inhibited by radical scavengers but not by epoxide hydrolase. The results indicate that the microsomal cytochrome P-450-dependent oxidation of benzene is mediated by hydroxyl radicals formed in a modified Haber-Weiss reaction between hydrogen peroxide and superoxide anions and suggest that any cellular superoxide-generating system may be sufficient for the metabolic activation of benzene and structurally related compounds.

The mechanism of cytochrome P-450-dependent oxidation of ethanol in reconstituted membrane vesicles

The mechanism of cytochrome P-450-dependent oxidation of ethanol has been investigated using reconstituted phospholipid vesicles containing purified preparations of rabbit liver microsomal NADPH-cytochrome P-450 reductase and cytochrome P-450 LM2. Incorporation of cytochrome b5 into the vesicles resulted in a 5-fold enhancement of cytochrome P-450-catalyzed O-dealkylation of 7-ethoxycoumarin, whereas the cytochrome P-450-dependent ethanol oxidation was slightly inhibited. Superoxide dismutase, added in increasing amounts to the vesicles, inhibited the formation of superoxide anions and, in a concomitant manner, also the production of acetaldehyde from ethanol in the system. Also horseradish peroxidase inhibited ethanol oxidation catalyzed by the vesicles; acetaldehyde formation and H2O2 formation decreased in a concomitant manner as the amount of the peroxidase was increased. Externally added hydrogen peroxide markedly stimulated cytochrome P-450-dependent ethanol oxidation, but not until the concentration of H2O2 reached 0.3 mM, whereas the hydroxyl radical scavenger mannitol completely inhibited the cytochrome P-450-dependent acetaldehyde production. Oxidation of ethanol was also accomplished using vesicles containing cytochrome b5 instead of cytochrome P-450 and in other systems regenerating superoxide anions, e.g. the xanthine-xanthine oxidase system and dihydroxyfumarate. The results are consistent with an iron-catalyzed Haber-Weiss mechanism for regeneration of hydroxyl radicals which subsequently react with ethanol, thereby giving the corresponding aldehyde.

Comparison between directional Doppler and angiography in the diagnosis of internal carotid artery disease

Directional Doppler examination (DD) with flow registration over the supraorbital and supratrochlear arteries and over the carotid artery in the neck was adopted to 99 carotid arteries in 56 patients without previous knowledge of angiography results, and thereafter DD and angiography findings were compared. On subgrouping of the angiography results into internal carotid artery (ICA) stenosis less than 50%, greater than 50%, and occlusion, a correct diagnosis was obtained by DD on 90 vessels (91%). All 11 ICA occlusions were correctly diagnosed by DD. The incorrect results obtained with DD were as follows: Four ICA stenosis less than 50% were classified as stenosis greater than 50%; four stenosis greater than 50% were classified as less than 50%; one stenosis greater than 50% was classified as occlusion. DD is a useful noninvasive screening method for the detection of occlusion and greater than 50% stenosis of ICA.

Carotid angiography of arteriovenous malformations during operation

The value of carotid angiography during operation in the surgical treatment of arteriovenous malformation is illustrated by 4 patients. After obliteration of the main supply to the malformation the blood may be redistributed to possible smaller feeding vessels now dilated and more clearly demonstrable than preoperatively. In some cases, angiography both preoperatively and during operation may be needed for a demonstration of the whole malformation with all its feeding vessels. Angiography during operation reduces the need for postoperative angiography.

Prognosis in patients with infarction and TIA in carotid territory during and after anticoagulant therapy

One hundred seventeen patients, 31 with TIA and 86 with cerebral infarction, had angiographically verified atherosclerosis within the relevant carotid artery territory and normal CSF. They were treated with anticoagulants for a mean of 11.1 months. No TIA but 1 cerebral infarction, appearing during inadequate anticoagulant therapy, was registered. Seventy-six of the patients, 20 with TIA and 56 with infarction, were followed for a mean of 4.4 months after cessation of anticoagulants or during inadequate antinecessitating re-institution of anticoagulant therapy. Long-term, anticoagulant treatment can be recommended in carefully selected patients with TIA, and also with infarction in the carotid territory.

Chromatographic properties of Sephacryl S-300 Superfine

Sephacryl S-300 Superfine is a new gel filtration medium that consists of allyldextran crosslinked with N,N'-methylenebisacrylamide. It was shown to have a separation range for proteins that extends to 1--2 x 10(6) dalton. The gel filtration properties were characterized by fractionation of human serum and of bovine colostrum. Thyroglobulin from pig could be isolated in one step in a very pure form. The flow properties were characterized by the relationship between flow rate and pressure drop. It was shown that Sephacryl has very good flow properties in comparison with Sephadex G-200 and that it can be used in large-scale columns.

Copper intrauterine contraceptive devices in adolescent nulliparae

Copper intrauterine contraceptive devices (IUCDs) were used in 243 young nulligravidae attending a gynaecological clinic for schoolgirls in Uppsala between March 1973 and June 1975; 226 of these girls (93%) were seen again during December 1975 making a total of 3138 months of observation. At the time of follow up, 126 patients (55.8%) still had the IUCD in situ; 20% had expelled the IUCD and in another 24.2% the IUCD had been removed because of bleeding and/or pain or because of suspected pelvic inflammatory disease (7 patients). Twelve of the girls conceived during the period of observation making the Pearl index 4.6; nine of the conceptions occurred within nine months of the insertion of the IUCD. Unlike others we do not advocate the use of the IUCD for young nulligravidae.

Gastric secretion and its facilitation as related to gastric mucosal histamine

1. In conscious rats provided with Pavlov or Heidenhain pouches the acid and pepsin responses to vagal stimulation, or infusions of gastrin, histamine, methacholine, and to various combinations of these stimulants have been established. The concomitant mobilization and increased formation of gastric mucosal histamine have also been examined.2. Histamine evoked graded acid responses in the Pavlov and Heidenhain pouches. The innervated pouch was more sensitive to histamine than the denervated. Stimulation of pepsin secretion was apparent only in the Heidenhain pouch.3. The acid response to vagal stimulation evoked by 2-deoxy-D-glucose was facilitated by infusion of histamine, but not that of pepsin, the secretion of which was depressed.4. Acid secretion in response to graded infusion of methacholine was enhanced by background infusions of histamine in subthreshold, sub-maximal and maximal dosages.5. The acid response to vagal stimulation was enhanced by a background infusion of gastrin, but not that of pepsin, the secretion of which was depressed.6. A background infusion of a large dose of histamine depressed the maximal acid response to gastrin in both types of pouches.7. Administration of histamine restrained the accelerating effect of gastrin on histidine decarboxylase activity, probably by a feed-back coupling.8. The increase in gastric mucosal histamine, as reflected in its urinary excretion, in response to gastrin infusion was enhanced by vagal stimulation.9. The amounts of histamine that can be mobilized and newly formed in the gastric mucosa have been evaluated and found to be fully adequate for efficient stimulation of the parietal cell.

Inhibitory and stimulatory effects of secretin on gastric secretion in conscious rats

1. The effect of pure secretin on gastrin-induced secretion has been studied in conscious rats with Pavlov or Heidenhain pouches.2. Rapid intravenous injection of secretin did not inhibit a plateau secretion of acid in the Heidenhain pouch, but infusion of the same amount of secretin over two hours inhibited secretion in both Heidenhain and Pavlov pouches.3. A rapid intravenous injection of secretin before the onset of gastrin infusion enhanced the acid secretory response to gastrin in both types of pouches.4. Secretin stimulated pepsin secretion.

Inhibition of gastric secretion by atropine in conscious rats

1. The effect of atropine on acid and pepsin secretion, stimulated by feeding, vagus excitation or infusions of gastrin, histamine and methacholine, was studied in conscious rats provided with a Pavlov or a Heidenhain pouch.2. The acid and pepsin secretion in response to food was substantially suppressed by atropine in the Pavlov pouch.3. The strong stimulatory effect of 2-deoxy-D-glucose on acid and pepsin secretion in the Pavlov pouch was almost abolished by atropine.4. A plateau secretion of acid obtained by infusion of submaximal doses of hog gastrin II, was significantly inhibited by atropine in the Pavlov and the Heidenhain pouch.5. Methacholine-induced acid and pepsin secretion in the denervated Heidenhain pouch was nearly completely inhibited by atropine.6. A plateau secretion of acid evoked by infusing histamine in a near maximal dosage was inhibited by atropine to the same extent as the gastrin-induced secretion in the Pavlov pouch.7. The mode of action of atropine as a gastric secretory inhibitor is discussed.