COMPARATIVE STUDIES ON RESPIRATION : V. THE EFFECT OF ETHER ON THE PRODUCTION OF CARBON DIOXIDE BY ANIMALS.

1. The experiments on frog tadpoles show that with 0.15, 0.37, and 0.55 per cent ether solutions there is a decrease in CO₂ output. The effect is reversible. With these concentrations the breathing movements and body movements remained normal during the experiment. In 3.65 and 7.3 per cent ether there is a decrease of respiration followed by an increase which in turn is followed by a decrease. The increase may reach about three times the normal rate. The increase in the CO₂ output is accompanied by the peeling of the skin. The effect is irreversible. 2. Experiments on an aquatic insect, Dineutes assimilis Aube, show that in 7.3 per cent ether there is a decrease followed by an increase which in turn is followed by a decrease. There is no apparent disintegration of structures in the organism accompanying the increase. The effect is irreversible. 3. The experiments on frog eggs with 7.3 per cent ether show a result similar to that found in aquatic insects. 4. Experiments on Fundulus embryos show that with 0.73 per cent ether there is a reversible decrease in the rate of CO₂ production. In 3.65 per cent ether there is a temporary decrease followed by an increase, after which the rate begins to fall off. In 7.3 per cent ether there is an immediate increase amounting to 307 per cent which is followed by a decrease. The increase in the 3.65 and 7.3 per cent ether is accompanied by irreversible changes leading to death. The decrease found in 0.73 per cent ether is not sufficient to cause narcosis, as is shown by experiments on which the same decrease is produced by lowering the temperature. 5. These experiments show that narcosis is not due to asphyxia. The action of anesthetics is due to some other cause than the effect on respiration. There is a difference between the animals studied and the plants described in this series of articles, since in animals the increase in the CO₂ output is accompanied by irreversible changes leading to death, while this is not necessarily the case in plants. The reversible (narcotic) action of ether on the animals studied was accompanied by a decrease in the carbon dioxide output; in plants this is not ordinarily the case. These facts are of considerable interest, but their interpretation must be left to future investigation.     

COMPARATIVE STUDIES ON RESPIRATION : III. THE EFFECT OF ETHER ON THE RESPIRATION AND GROWTH OF BACILLUS SUBTILIS.

1. In all the concentrations of ether studied (from 0.037 to 7.3 per cent) there is an increase in the rate of respiration of Bacillus subtilis followed by a decrease. 2. In 7.3 per cent ether in tap water there is an extraordinary increase in the output of CO₂ (amounting to 50 times the normal). This does not occur when 0.85 per cent NaCl is added, which indicates antagonism between ether and NaCl. 3. Ether is toxic in low concentrations (0.037 to 1.1 per cent) and high concentrations (3.65 to 7.3 per cent) but in intermediate concentrations (1.1 to 3.65 per cent) stimulates growth.     

COMPARATIVE STUDIES ON RESPIRATION : XIX. A PRELIMINARY STAGE IN THE PROGRESS OF ETHER ANESTHESIA.

Using these concentrations of ether (1 per cent, 3.65 per cent, 7.3 per cent), the following conclusions may be drawn. 1. The first effect of ether is to cause a depression in the rate of respiration. This is followed by a rapid rise above normal, which in turn is succeeded by a fall. 2. With all these concentrations the respiration is ultimately reduced to approximately the same level; the stronger the ether, the less time required to produce this result. 3. Even when the respiration has been reduced below normal, recovery is possible on removal from the ether, and appears to be complete, if sufficient time is allowed. If, however, the rate has been too far depressed, no recovery is possible. 4. These results extend those of Irwin on frog eggs and Fundulus embryos.     

COMPARATIVE STUDIES ON RESPIRATION : II. THE EFFECT OF ANESTHETICS AND OTHER SUBSTANCES ON THE RESPIRATION OF ASPERGILLUS NIGER.

1. In concentrations which are high enough to produce any effect, formaldehyde, ether, and acetone cause an increase, followed by a decrease, in the rate of respiration. 2. 3.65 per cent ether, which causes an increase with certain cultures, produces only a decrease with others. 3. The reaction producing an increase in the respiration with 7.3 per cent ether is a reversible process, while the reaction producing the decrease is not reversible. 4. 0.5 per cent caffeine produces only a decrease in respiration while a saturated solution causes an increase, which is followed by a decrease.     

Long Acting Single Injection Caudal Anesthesia—1,208 Obstetrical Deliveries with Mepivacaine

Long acting, single injection caudal anesthesia with mepivacaine was studied in 1,208 obstetrical cases.A 1 per cent solution was used in 671 patients and compared with a 1.5 per cent concentration in 537. No remarkable differences were found between the two groups. The 1 per cent solution provided relief of labor discomfort for from 60 to 180 minutes with an average of 110 minutes. In contrast, the 1.5 per cent solution provided an average of 115 minutes with a range of 80 to 210 minutes.A total volume of 30 ml of anesthetic agent yielded anesthesia to a level of the tenth thoracic vertebra or higher in 91 per cent of patients.Significant alterations in blood pressure were uncommon. About 1 per cent of patients required a vasopressor because of a drop in systolic blood pressure below 80 mm of mercury. Another 8 per cent had a drop of over 20 points in systolic pressure but from high enough levels that they did not require a vasopressor.Toxic effects similar to those of lidocaine were found in slightly more than 1 per cent of cases.This anesthesia requires a higher incidence of operative intervention for delivery.     

Ethanol extraction of free amino acids from soil

Summary A technique was developed for extracting and analyzing the free amino acid fraction of soil. Ethanol was used as an extracting agent. Ethanolextraction curves showed 20 per cent ethanol was the optimum percentage for extraction. Extraction-time curves indicated 18 to 20 hours of extraction with 20 per cent ethanol produced satisfactory results.The free amino acid fraction of soil was characterized and the limitations of the technique were determined. The naturally occurring amino acids extracted with 20 per cent ethanol were limited to acidic and neutral amino acids; basic amino acids were not extracted in sufficient quantities to permit detection. Based on the percent recovery of amino acids incorporated into soil and extracted with 20 per cent ethanol 90 to 95 per cent of the acidic, 80 to 85 per cent of the neutral and 1 to 5 per cent of the basic amino acids used were recovered with the technique.     

The Quantitative Yield in Purification of Cytokinins. Model-experiments with Kinetin, 6-Furfuryl-amino-purine

Model-experiments with kinetin, 6-furfuryl-amino-purine, to determine the quantitative yield in purification of cytokinin extracts have been performed. If kinetin in acidic water solution is partitioned three times with equal volumes of ethyl ether, about 50 per cent of the kinetin passes into the ether phases. In similar experiments with ethyl acetate more than 90 per cent of the kinetin goes over to the ethyl acetate phases. Accordingly, use of these two solvents in purification of cytokinin extracts leads to very large losses. Use of petroleum ether or n-hexane on the other hand leads to none or very small losses. Partitioning of alkaline kinetin solutions three times with equal volumes of 1-butanol results in an almost quantitatitve extraction of the kinetin from the water solution. About 7 per cent of the original amount of kinetin follows the acid auxin, when a saturated ether solution of kinetin is extracted according to a common method for acid auxins. Kinetin may thus interfere in later analyses for auxins. The dangers involved when cytokinins are “purified” according to normal practice are pointed out.     

LOCAL ANESTHESIA IN OPHTHALMOLOGY

With local anesthesia for intraocular operations, postoperative agitation, nausea and vomiting are less frequent, which tends to reduce the number of intraocular complications. Bleeding is less troublesome, and secretions are better controlled. Fewer cardiac and pulmonary complications occur with local anesthesia.Meperidine hydrochloride (Demerol®) and pentobarbital sodium (nembutal) remain drugs of choice in preoperative medication. Lidocaine (Xylocaine®), 1 or 2 per cent, is a most satisfactory local anesthetic for intraocular operations.Complete akinesia of the eyelids has been achieved in every instance by a modified combination of the O''Brien and Van Lint techniques, using lidocaine 1 per cent.Nasolacrimal procedures can be performed satisfactorily by injecting the nasociliary and infraorbital nerves with lidocaine 2 per cent.     

AN EVALUATION OF CESAREAN SECTION

The risks of cesarean section have been reduced in step with the increase in safety of all major surgical procedures.In a series of 13,153 deliveries, 1,265 (9.6 per cent) were by cesarean section. There were three obstetrical maternal deaths in 11,888 cases in which delivery was by the vaginal route—0.025 per cent. In the series of 1,265 deliveries by cesarean section there was one death attributable to the operation—0.08 per cent.The total uncorrected fetal loss following cesarean section was 3.8 per cent. This compares favorably with fetal loss of 3.2 per cent in the vaginal delivery group in this series, and with fetal loss rates reported from large obstetrical centers.Anesthesia by spinal injection is the method of choice in cesarean section. There were no maternal deaths or accidents attributable to spinal anesthetic, and in no case was it felt that fetal death was attributable to it.The incidence of maternal morbidity in the cesarean section group following spinal anesthesia was 15.8 per cent—less than half the incidence of morbidity following inhalation anesthesia.     

In vivo studies of carnitine and fatty acid metabolism: Problems with use of anesthetics

The use of ether anesthesia as a technique for obtaining liver tissue and plasma from living rats was compared to decapitation followed by in situ sample freezing. Parameters associated with fatty acid metabolism were examined to demonstrate differences in the two methodologies. Use of ether in fasted rats was associated with lower plasma free fatty acids and acetoacetate concentrations, as well as decreased hepatic total carnitine, carnitine, and acid-soluble acylcarnitine content when compared to decapitated animals. No qualitative differences between the ether and decapitated groups were noted, and the quantitative differences observed were consistent with effects induced by the anesthetic. Thus, with respect to in vivo studies of fatty acid metabolism use of anesthetic agents may induce significant changes without providing advantages over decapitation and in situ freezing.     

ISOLATION OF HYDROPHOBIC PROTEINS BINDING NEUROTRANSMITTER AMINO ACIDS: γ-AMINOBUTYRIC ACID RECEPTOR OF THE SHRIMP MUSCLE

Abstract— The total lipid extract of shrimp muscle ( Artemisia longinaris ) was precipitated with ether. The supernatant containing 95 per cent of the phospholipids and 50 per cent of the protein showed binding for L-[¹⁴C]glutamatc in the first peak of protein. The sediment, redissolved in chloroform-methanol was chromatographed on a Sephadex LH-20 column. A single peak was eluted in the chloroform (20-40 ml) having no lipid phosphorous and high affinity binding for [¹⁴C]GABA. The saturation was achieved at 1 mole per 80.000 g protein and the curve revealed a single type of binding site. The purification achieved was of about 4000-fold. There was no binding of L-[¹⁴C]glulamate to the ether precipitate. The specificity of the binding of [¹⁴C]GABA was further supported by competition experiments with bicuculline. picro-toxin and muscimol. It is suggested that the hydrophobic protein isolated by us represents the GABA receptor. The findings presented in the two papers of the series suggest that the excitatory and inhibitory receptor from crustacean muscle can be separated as two different proteins.     

Cardiac screening procedures

Seven per cent of a sample group of civil service employees were found to have diagnosable heart disease. The diagnosis was made on the basis of a complete physical examination and history taken by a specialist in internal medicine and/or heart disease. In addition a questionnaire form related to symptoms of heart disease was filled out by the patient, and various laboratory tests were made. As a technique in cardiac case-finding, the electrocardiogram was the best single device. Of all the cases of heart disease in this survey 65 per cent were detected from tracings obtained by using all 12 leads, and 57 per cent if only the three standard limb leads were taken; but of the presumably normal persons, 13 per cent would be erroneously suspected of possible heart disease by this technique. Heart disease was detected in 50 per cent of the diagnosed cases on the basis of answers to three of the questions in the questionnaire. Eighteen per cent of normal persons would also have been suspected of having heart disease by this case-finding device. Although the survey reported did not develop a simple cardiac case-finding technique, the data presented indicated that a questionnaire history-form, if judiciously used and evaluated, may be of value to physicians who examine large numbers of patients who are unwilling to submit to a complete cardiac evaluation.     

CRYSTALLINE TRYPSIN : V. KINETICS OF THE DIGESTION OF PROTEINS WITH CRUDE AND CRYSTALLINE TRYPSIN

The rate of digestion, as determined by the increase in non-protein nitrogen or formol titration, of casein, gelatin, and hemoglobin with crystalline trypsin preparations increases nearly in proportion to the concentration of protein, but with crude pancreatic extract the rate of digestion becomes independent of the protein concentration in concentrations of more than 2.5 per cent. With both enzymes the rate of digestion of mixtures of 5 per cent casein and gelatin is greater than would be expected from the point of view of a compound between enzyme and substrate. The rate of digestion of 5 per cent casein in the presence of 5 per cent gelatin is exactly the same as that of 5 per cent casein alone. This result is obtained with both enzymes. The digestion of casein with crude trypsin follows the course of a monomolecular reaction quite closely while with purified trypsin the velocity constant decreases as the reaction proceeds. In the case of hemoglobin the monomolecular velocity constant decreases with both purified and crude enzyme. When the reaction is followed by changes in the viscosity of the solution the abnormal effect of changing substrate concentration disappears and the reaction is in fair agreement with the monomolecular equation. The results as a whole indicate that the abnormalities of the reaction are due to the occurrence of several consecutive reactions rather than to the formation of a substrate enzyme compound.     

THE EFFECT OF LOW OXYGEN TENSION ON TISSUE METABOLISM (RETINA)

Lactic acid production by rat retina in a medium containing phosphate was studied chemically. One half as much lactic acid was found as in a medium containing bicarbonate. In our experience the rate of respiration in a phosphate medium was sensitive to oxygen tension, for it was 38 per cent lower at 10 per cent and 51 per cent lower at 5 per cent oxygen than at 100 per cent oxygen. Previously Laser had reported no decrease in respiration at 5 per cent oxygen in phosphate medium. In phosphate medium, when the oxygen tension was varied, respiration and glycolysis bore a reciprocal relationship to each other. In bicarbonate medium, when the oxygen tension was lowered from 95 per cent to 5 per cent there was no significant change in the respiration, but glycolysis was increased nearly to the anaerobic level. This agrees with the earlier experiment of Laser in bicarbonate medium and adds support to his conclusion that the rate of glycolysis is controlled by oxygen tension rather than by the rate of respiration, under the conditions of the experiment.     

粉剂防治粘虫Pseudaletia separata (Walker)研究

粘虫Pseudaletia separata(Walker)是粮食作物的毁灭性害虫,也是全国农业发展纲要(修正草案)所规定要消灭的八大害虫之一。粘虫在大发生时为害面积很广,虫体发育迅速,食量很大,过去多采用人工器械捕打办法,但不能澈底解决问题,尤其在作物密植的情况下,捕打也发生了困难,常因捕打时将作物践踏而引起损失,因此要求在发生时应用化学防治方法,以达到迅速消灭为害之目的。     

Androgen metabolism by rat epididymis. 1. Metabolic conversion of 3 H-testosterone in vivo

The epididymis of adult rats metabolize ³H-testosterone by experiments $\text{in vivo}$. Thirty minutes after the injection of 100 μCi ³H-testosterone, some 10 per cent of the total radioactivity of the epididymis was found in the water-soluble fraction, whereas 90 per cent was found in the ether soluble fraction (free steroids). The free steroids were examined further and the following androgenic metabolites identified: $\text{testosterone}$ (17β-hydroxy-4-androsten-3-one) 8, 9%, $\text{androstendipne}$ (4-androstene-3, 17-dione, 2,7%,$\text{5α-A-dione}$ (5α-androstane-3, 17-dione) 6,5%, $\text{DHT}$ (17β-hydroxy-5α-androstan-3-one) 47, 2%, $\text{3β-diol}$ (5α-androstane-3β, 17β-diol) 4, 4%, $\text{3α-diol}$ (5α-androstane-3α,17β-diol) 20, 8% and $\text{androsterone}$ (3α-hydroxy-5α-androstan-3-one) 3,4%. The relative amount of each metabolite is given in per cent of total radioactivity in the ether soluble fraction.     

Impact of ether anesthesia on the hypophyseal content of oxytocin neurophysin I and II: a comparative study with ketamine in the rat

The effect of anesthetic stress on the major hormones of the posterior pituitary (PP), such as oxytocin (OT), oxytocin-neurophysin (OTNP-I) and its metabolic product, OTNP-II, was studied. Rats were treated with either a combination of atropine (0.87 mg/kg) and diphenylhydantoin (85 mg/kg) and then anesthetized with ketamine (42 mg/kg) or were directly anesthetized with diethyl-ether, and then killed. Controls were killed with a laboratory guillotine. Our study revealed that 1.) animals killed with a guillotine or being medicated with our drug combination prior to sacrifice had similar concentrations of OT, OTNP-I and OTNP-II per PP and ml of blood; 2.) animals anesthetized with either prior to sacrifice had a decreased concentration of neuropeptides per PP; the blood concentration of OT was 1.6 times higher than in animals treated with the drug combination or killed directly with a guillotine. In addition plasma concentrations of OTNP-I and OTNP-II were above the baseline. We conclude that ether is not an adequate anesthetic for studying the neurophysins from the PP in vivo. Treatment of animals with atropine and diphenylhydantoin in combination with ketamine does not alter the profile of the major hormones from the PP during anesthetic stress.     

Effects of excess dietary phenylalanine on composition of cerebral lipids

Abstract— Concentrations in whole rat brains of lipids (total lipids, phospholipids, galactolipids, cholesterol, plasmalogens) and of proteolipid protein were not altered after feeding for 2 and 6 weeks of diets containing 5 per cent excess l -phenylalanine. After 2 weeks of diet with 7 per cent excess l -phenylalanine there was a slight reduction (5–10 per cent) in the concentrations in whole brain of cholesterol and galactolipids. No significant effects were noted in cerebral hemispheres after 3 weeks of diets with 7 per cent excess l -phenylalanine. In the 5 and 7 per cent supplemented groups of animals, the total amounts of the various lipids were initially reduced to levels which were within 10 per cent of those in diet-matched controls. The results for rats indicate that after 3 weeks of age only very moderate effects on accumulation of cerebral lipids can be produced by excess dietary l -phenylalanine fed at the most toxic levels of supplementation, while lower levels of dietary supplementation are without effect. The results suggest further that the more mature brain is resistant to alteration of deposition of myelin lipids by high levels of phenylalanine.     

Fat Metabolism in the West African Oil Palm (Elaeis Guineensis): PART I. FATTY ACID FORMATION IN THE MATURING KERNEL

Using a column chromatographic technique for the estimationand identification of fatty acids, a study has been made offat formation in developing Oil Palm kernels from 10 weeks afterpollination to full maturity (20 weeks), during which time thefat content may increase a hundredfold. Nuts from three differenttrees have been analysed and differences between these in ratesof maturation (as indicated by appearance of the endosperm)can be directly correlated with changes in character of theoil present. Amounts of reducing sugars, sucrose, and starch in the developingendosperm have also been followed, but these carbohydrates arepresent throughout in low concentration, and it is assumed thattranslocation from the rest of the plant to the developing kernelmust account for the major part of storage material. The mature kernel contains in its fat an unusual mixture ofeight different saturated fatty acids. The major such componentis lauric acid (46·1 to 49·5 per cent.) and thereare present two common unsaturated acids, oleic (15·7to 16·5 per cent.) and linoleic acid (0·7 to 3·1per cent.). At the earliest stage examined (10 weeks after pollination)all these acids are.present but in altered proportions, unsaturatedacids forming a larger fraction (36·5 to 81·2per cent., according to the tree investigated), and lauric acid(1·4 to 8·5 per cent.) a smaller. The results suggest that young kernels contain a small quantityof a largely unsaturated ‘protoplasmic’ fat, andthat at a certain stage in development some physiological changein the tissue results in the formation, in large quantities,of a new, highly saturated storage fat. No fatty acid interconversionscould be demonstrated although there is some suggestion thatoleic acid behaves anomalously. There is evidence that free fatty acids are not accumulatedprior to esterification.     

THE IMMUNOLOGICAL SPECIFICITY OF THE EUGLOBULIN AND PSEUDOGLOBULIN FRACTIONS OF HORSE AND H^MAN SERUM

That portion of horse and human serum globulin precipitated by 33 per cent saturation with ammonium sulfate and precipitated on subsequent dialysis was taken as euglobulin; and the fraction precipitated between 33 and 50 per cent saturation and remaining in solution on subsequent dialysis was taken as pseudoglobulin. The sera of rabbits injected with either of these antigens gave precipitation with both. However, two distinct and fraction-specific antibodies could be demonstrated by absorbing the sera with the one antigen, and testing the supernatant fluid with the other. The experimental results are adequately explained on the basis that there are at least two antigenically distinct globulins in serum which we may term globulin I and globulin II and which are largely associated with so called euglobulin and pseudoglobulin respectively. The ordinary methods of salting out and dialysis do not effect complete separation and each globulin preparation contains a trace of the other antigen. The antisera to these euglobulin and pseudoglobulin preparations therefore contain antibodies to both antigens. Each protein solution precipitates all the antibody specific for the one antigen and in addition, by virtue of the trace of contaminating protein, precipitates a portion, and only a portion of the antibody specific for the other antigen. The fact that antisera to whole serum contain these same fraction-specific antibodies suggests that this immunological specificity is an inherent property of two globulins present as such in serum and is not an artifact induced by their precipitation and purification. Lipoids extracted from the globulins by ether, petroleum ether, and alcohol give no demonstrable reaction with antisera to these globulins; antisera absorbed with a large excess of lipoid are not affected as regards their reactivity with the original protein; and globulins extracted with ether and petroleum ether at room temperature are not affected as regards their reactivity with antisera. It is concluded that the immunological specificity of the globulin fractions as evidenced by the precipitation reaction is not determined by lipoids associated with the protein.