An evaluation of anti-multiplier factors in kidneys with obstructed ureters

Ureteral obstruction has been known to reduce the renal concentration gradients of chloride, sodium, urea, and osmolality. A quantitative analysis of the factors responsible for the decrease in the gradients has been performed. By applying the equation of conservation of matter to data obtained in this laboratory it is concluded that:a. at least, 62.5 per cent of the decrease in concentration gradients is due to drainage by circulatory vessels;b. at most, 25 per cent of the decrease is due to increase in water content of medulla; andc. at most, 12.5 per cent of the decrease is due to diffusion of solutes through the interstitium. Work done under the tenure of an Established Investigatorship of the American Heart Association.     

The effect of container porosity on root environment and plant growth

Summary The effect of container porosity on water relations in the substrate and on plant growth was examined. With clay containers the proportional effect of the wall on water loss varied with season, being responsible for 42 per cent of the total loss in winter and 25 per cent in summer. Water loss from plastic containers was 55 per cent of that from clay containers in winter, and 66 per cent in summer. Wall porosity also had a significant effect on water distribution within the container under high radiation conditions. Tomato plants grown under three water regimes showed no effect of matric stress in winter, but growth was significantly reduced for each increase in stress in summer. There was no interaction between container type and water stress. Non-porous containers gave a higher water-use efficiency and had a lower irrigation requirement than porous ones, their greatest advantage being under conditions of low transpirational loss and high evaporative loss.     

The Effects of Temperature on Root Initiation in Detached Cotyledons of Sinapis alba L.

A thermoplate system is described which enables uniformly illuminatedpetri dish cultures to be maintained under a range of temperatureregimes. The system is evaluated and used to investigate theeffects of incubation temperatures between 10 and 35 ?C on rootinitiation. Sinapis cotyledons root most rapidly and in greatest numbersat 25 and 30 ?C. Below 25 ?C, rooting is reduced and delayed,and above 30 ?C rooting is prevented. The optimum temperaturefor initiation of primordia is close to 25 ?C, where, after4 days over 80 per cent of petioles have at least one primordiumand over half of these are already elongating. Initiation isconsiderably reduced at temperatures above 30 ?C and below 25?C and primordium elongation either fails to take place (35?C) or is delayed (20, 13, 10 ?C). At 25 ?C, 90 per cent of the primordia are initiated in theterminal 1.5 mm of the petriole. A similar pattern occurs atother temperatures, but the relative numbers of primordia initiatedin the upper petiole are increased when cotyledons are incubatedat temperatures below 25 ?C. At 25 ?C a higher proportion ofprimordia are initiated in the upper petiole in cotyledons withmany primordia than in cotyledons with few, but the developmentof primordia to the elongation stage is not affected by theirposition in the petiole nor by the numbers of primordia present.     

The role of external irradiation in the treatment of transitional cell carcinoma of the bladder-a review of fifty cases

Of 100 patients with carcinoma of the bladder seen in the Section of Therapeutic Radiology, University of California, San Francisco, between 1957 and 1962, 59 were accepted for radiation treatment. Fifty had transitional cell carcinoma and were treated with supervolt therapy (1 mev or cobalt-60).TWO TYPES OF TUMORS WERE AGAIN FOUND SUITABLE FOR EXTERNAL IRRADIATION: Papillary carcinomas Grades II and III, as long as they have not, or at least have not massively, invaded muscle; and undifferentiated carcinomas, Grade IV, regardless of degree of extension through the pelvis. The former type, if single, is treated by irradiation for the first recurrence after one attempt with radical transurethral resection. In the presence of multiple lesions at the first examination, radiation therapy is given immediately. The latter type is treated by radiation therapy without any attempt at surgical removal.Of 37 patients, Stages A to C, treated more than three years ago, 14 (38 per cent) lived more than three years and eight (22 per cent) had no cystoscopic or clinical signs of active disease and had normal bladder function. Of 23 patients treated more than five years ago, eight were alive after five years (35 per cent) and four (17 per cent) remained controlled by radiation therapy alone, with normal bladder function.No major complications were observed. In particular, no fibrosis of the bladder occurred. Doses ranged from 5,000 r in five and a half weeks to 6,000 r in seven weeks.A close cooperation between urologic surgeons and radiotherapists during recent years permits long-range treatment planning from the time of diagnosis, which is essential in the effective therapy of carcinoma of the bladder.     

The Role of External Irradiation in the Treatment of Transitional Cell Carcinoma of the Bladder—A Review of Fifty Cases

Of 100 patients with carcinoma of the bladder seen in the Section of Therapeutic Radiology, University of California, San Francisco, between 1957 and 1962, 59 were accepted for radiation treatment. Fifty had transitional cell carcinoma and were treated with supervolt therapy (1 mev or cobalt-60).Two types of tumors were again found suitable for external irradiation: Papillary carcinomas Grades II and III, as long as they have not, or at least have not massively, invaded muscle; and undifferentiated carcinomas, Grade IV, regardless of degree of extension through the pelvis. The former type, if single, is treated by irradiation for the first recurrence after one attempt with radical transurethral resection. In the presence of multiple lesions at the first examination, radiation therapy is given immediately. The latter type is treated by radiation therapy without any attempt at surgical removal.Of 37 patients, Stages A to C, treated more than three years ago, 14 (38 per cent) lived more than three years and eight (22 per cent) had no cystoscopic or clinical signs of active disease and had normal bladder function. Of 23 patients treated more than five years ago, eight were alive after five years (35 per cent) and four (17 per cent) remained controlled by radiation therapy alone, with normal bladder function.No major complications were observed. In particular, no fibrosis of the bladder occurred. Doses ranged from 5,000 r in five and a half weeks to 6,000 r in seven weeks.A close cooperation between urologic surgeons and radiotherapists during recent years permits long-range treatment planning from the time of diagnosis, which is essential in the effective therapy of carcinoma of the bladder.     

Effect of varying static and changing moisture levels during incubation on extractability of soil phosphate

Summary A sandy loam (pH 6.5) was incubated at 28°C at static moisture levels, ranging from 10 per cent saturation to 133 per cent saturation (waterlogging), for 6 and 12 weeks; other samples covering the same moisture range were first incubated for 6 weeks, and after changing all moisture levels to 50 per cent saturation were incubated for a further 6 weeks.With increasing static soil moisture level during incubation there was a slight reduction in Morgan-extractable phosphate up to 70 per cent saturation, but thereafter, due to anaerobic effects, there were considerable increases in extractable phosphate with increasing moisture level.With changing moisture level during incubation the effects of anaerobiosis became apparent where original moisture level was greater than 50 per cent saturation; extractable phosphate was reduced to levels lower than those occurring where the soil was maintained continuously at 50 per cent saturation. The extent of reduction in extractable phosphate increased with original soil saturation level.     

Investigating movement in the laboratory: dispersal apparatus designs and the red flour beetle,Tribolium castaneum

The natural dispersal of Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) has been emulated in the laboratory for more than 50 years, using a simple dispersal apparatus. This has typically comprised of a starting container (initial resource or patch) connected by tubing, which contains thread for the animals to climb into a tube and hence to an end container. That is, beetles move to a new viable resource or patch from an inter‐patch zone or non‐viable habitat. We modified this basic apparatus design to test the effect of tubing length and tubing insertion angle on the dispersal rate and proportion of successful dispersers. We expected that the proportion of successful dispersers would be repeatable within each apparatus design, and that increasing tubing length and steepness of the insertion angle would reduce dispersal rate and success across apparatus designs. Dispersal increased linearly through time, similarly so for both males and females. The design with the most vertical tubing insertion angle had a lower proportion of successful dispersers. Tubing length also had a negative relationship with dispersal success (as judged by insects reaching the end container), but a significant reduction in dispersal success was only apparent between the shortest and longest tubing between containers. We suggest that locating and climbing the vertical section of string before they can enter the tubing between containers restricts dispersal and that at higher densities, insects exhibit greater inclination to climb. This type of apparatus has flexible design tolerances and further potential to study the dispersal of other small insect species that primarily use pedestrian locomotion.     

Automatic lipid extraction and thin-layer chromatography application with a prgrammed flow system

An eight-channel programmed flow system for automatic lipid extraction and TLC application is described. Each channel has a container for lipid extraction connected by Acidflex tubing through an AutoAnalyzer pump to a TLC applicator needle. Extraction containers are prepared from disposable Oxford sampler pipet tips by inserting a small cotton filter into their lower, narrower end, which is connected to the pump tubing. The applicator needles are supported vertically in a manifold, and their tips rest on a TLC plate placed on a hot plate. Serum is added to isopropanol in each extraction container, and proteins are completely precipitated in 2 min and retained in the extraction chambers by the cotton filters; lipid extracts are then transferred on to the heated TLC plate by intermittent pumping at a rate allowing for continuous evaporation of isopropanol under streams of warmed air or nitrogen. The lipids accumulate on the plate in eight small spots, one for each channel. Solvent is proportionally added into the extraction chambers from a common reservoir through Acidflex tubing in a second AutoAnalyzer pump. During the extraction procedure, both pump motors are automatically operated by a programmed timer with a solid-state switch. Of several different solvents tested, isopropanol is the fastest for protein precipitation and lipid extraction and does not extract substances from the Acidflex tubing which interfere with chromatographic separation.     

Contraceptive use and efficacy in a genetically counseled population

Abstract

This paper reports contraceptive use and efficacy rates among 648 married women aged 15 to 44 who had received genetic counseling six months previously. Over half (53.5 per cent) of the counseled population were using non‐surgical contraception; 20 per cent were pregnant or postpartum; 10 per cent were seeking to become pregnant; 11 per cent were sterilized. Only 4.5 per cent were neither using contraceptives nor seeking to become pregnant. Women who were certain about their reproductive intentions after counseling utilized contraceptives effectively, with only two pregnancies at six months among those seeking to delay wanted pregnancies and only one pregnancy among those seeking to prevent pregnancy. This represents six‐month contraceptive failure rates of 4.3 and 2.1 per cent respectively for the two groups, rates similar to those with comparable intentions in the U. S. population at large. A distinguishing characteristic of the genetically counseled group was that 32 per cent of contraceptive users reported that their reproductive intentions were uncertain after counseling. The six‐month pregnancy rate in this uncertain group was 10 per cent.     

Etiotropic antibiotic therapy and immunotherapy of patients with pyo-inflammatory processes]

A 3-year experience was reviewed in the treatment of patients with pyoinflammatory processes (PIP) which developed during the postoperative period in 387 persons with closed injury and multiple penetrating wounds of the chest and stomach complicated by massive hemorrhage. When the PIP was localized in the abdominal cavity, enterobacteria and bacteroides were the main pathogens: 49.4 +/- 2.1 and 32.8 +/- 1.4 per cent, respectively. When the PIP was localized in the thoracic cavity, the most frequent pathogens were staphylococci, Pseudomonas aeruginosa, and enterobacteria: 26.5 +/- 1.4, 24.6 +/- 1.4 and 13.3 +/- 0.8 per cent, respectively. In all the cases high variability of the antibiotic susceptibility of the isolates and predominance of the strains resistant to 5 or more drugs were observed. A suppressive effect of thienam on the immune system was revealed. The immunocorrection in parallel with the antibiotic therapy made it possible to prevent further development of immune deficiency and to recover the bactericidal potency of the phagocyting cells. The use of various physiochemical methods in complex treatment of PIPs is substantiated.     

Some effects of temperature, meal size and body weight on gastric evacuation time in the dab Limanda limanda (L)

Gastric emptying time in the dab, Limanda limanda , has been studied using an X-ray technique. The addition of 25 % barium sulphate to a test meal did not significantly affect the transit time. Lowering the experimental temperature from 16.4 to 8.5°C markedly decreased gastric evacuation time. An increase in ration size led to an increase in the time required to empty the stomach and also to increase the amount of food digested per unit of time. For any given ration size, expressed as per cent body weight, the larger the animal the longer is the time required for evacuation of that meal. We suggest that the food intake per day, as a percentage of live body weight, will be smaller for larger L. limanda in the wild.     

ELECTRON MICROSCOPICAL STUDY OF SKELETAL MUSCLE DURING ISOTONIC (AFTERLOAD) AND ISOMETRIC CONTRACTION

Bundles of the curarized semitendinosus muscle of the frog were fixed during isotonic (afterload) and isometric contraction and the length of the A and I bands investigated by electron microscopy. The sarcomere length, during afterload contraction initiated at 25 per cent stretch, varied depending on the afterload applied between 3.0 and 1.2 µ, i.e. the shortening amounted to 5 to 50 per cent. The shortening involved both the A and I bands. Between a sarcomere length of 3.0 to 1.7 µ (shortening 5 to 35 per cent) the A bands remained practically constant at about 1.5 µ (6 to 8 per cent shortening); the length of the I bands decreased from 1.4 to 0.3 µ (80 per cent shortening). Below a sarcomere length of 1.7 to 1.2 µ the A bands shortened from 1.5 to 1.0 µ (from 6 to 8 to 25 per cent). At sarcomere lengths 1.6 to 1.2 µ the I band was replaced by a contraction band. During isometric contraction the A bands shortened by about 8 to 10 per cent; the I bands were correspondingly elongated.     

Transport of O2 along a model pathway through the respiratory region of the lung

A pathway through the system of branching in the respiratory region of the lung is modelled by a circular cylinder, closed at one end, with partitions which define the component respiratory units. In this model the transport of O₂ during inspiration, generated by diffusion is compared with that produced by diffusion together with convection and the importance of convection in the respiratory region in promoting oxygen uptake at the alveolar wall is discussed. For this discussion it is only necessary to consider inspiration. The equations are solved numerically for flow rates of 10, 85 and 200 liters/min. O₂ uptake at the wall and curves of constant O₂ concentration are shown to illustrate the influence of convection. It is found that after a 2 sec inspiration from an O₂ tension of 98 mm Hg and a lung volume of 2300 ml, convection is about 12 per cent as important as diffusion at a flow rate of 85 liters/min, whereas at 10 liters/min convection is only about 0.4 per cent as important as diffusion.     

Influence of seed moisture content and post-irradiation hydration temperature on the kinetics of reactivity towards oxygen or decay of oxygen-sensitive sites.

The rate of development of post-irradiation oxygen-dependent damage when oxygen is available, and its rate of elimination when seeds are first post-hydrated in oxygen-free water prior to their transfer to oxygenated water, was studied in barley seeds of approximately 3 per cent, approximately 8 per cent and approximately 9 per cent moisture contents at 3 degrees C, 25 degrees C and 37 degrees C. The magnitude of oxic damage at a given dose (35 krad) decreases as the initial seed moisture content increases from approximately 3 per cent to approximately 9 per cent. Significant (P = 0.01) oxic damage is observed in seeds of all the three moisture contents at 3 degrees C and 25 degrees C; however, at 37 degrees C significant (P = 0.01) oxic damage is observed only in seeds of approximately 3 per cent and approximately 8 per cent moisture contents. The magnitude of oxic damage in seeds of a given moisture content remains unaltered following oxygenated post-hydration of seeds at 3 degrees C and 25 degrees C, but it registers a significant (P = 0.01) decrease if post-hydration in oxygenated water is carried out at 37 degrees C. The radiation-induced oxygen-sensitive (An) sites react with oxygen approximately 6 to 8 times faster as compared to their rate of decay in the absence of oxygen at both 3 degrees C and 25 degrees C; however, at 37 degrees C they react only approximately 3 to 4 times faster, in seeds of all the three moisture contents. Moreover, the initiation of the decay of An sites becomes evident much earlier in very dry (approximately 3 per cent moist) seeds than in relatively moist (approximately 8 per cent and approximately 9 per cent) seeds. It is also observed that this fraction of An sites which is capable of a very rapid rate of decay in the absence of oxygen is capable also of an even more rapid rate of reactivity towards oxygen.     

A forced-air individually ventilated caging system for rodents

The practice of using a protective filter apparatus when housing five mice per cage resulted in ammonia levels exceeding 25 ppm. A forced-air individually ventilated caging system was constructed using polyvinyl-chloride tubing fitted to a rodent rack. The ammonia level was decreased using this ventilation system.     

Microbiological Synthesis of Fat: THE FORMATION OF FAT FROM SUCROSE

1. Forty-three strains of moulds, selected from ten species,were examined to ascertain their capabilities as producers offat, when grown in four different solutions of nutrient inorganicsalts together with sucrose. The three highest yields of feltwere given by Penicillium javanicum van Beyma, P. Soppi Zaleski,and Aspergillus nidulans Eidam, in that order. The fat contenton felt weight was maximal at 34·8 per cent, with P.Soppi, at 28·4 per cent. with Fusarium lini(1), and at25·8 per cent. with A. nidulans; on sugar utilized itwas maximal at 11·4 per cent. with P. Soppi, at 7·9per cent, with A. nidulans, and at 5·6 per cent. withF. lini(1). 2. Other moulds considered worthy of further trial were P. spinulosum,P. aurantiobrunneum, F. graminearum, A. flavus, F. oxysporum,A. clavatus, and P. oxalicum.     

The antibiotic prophylaxis of postoperative complications in breast cancer patients

The studies showed that infectious complications in patients operated for breast cancer (BC) most frequently developed after removal of the drainage tube resulting in poorer discharge favourable for development of infections. The causative agents in such cases are usually exogenous bacteria differing from endogenous ones (Staphylococcus epidermidis) inhabiting the human skin and sometimes contaminating the operative field. The endogenous bacteria are detectable bacteriologically in 60 per cent of the cases. Still, since the operation wound contains humoral and tissue immunity factors (specifically active against the host microflora) such bacteria rarely grow on artificial media (18 per cent) and even more rarely cause infections. Therefore, to prevent postoperative infections in patients with BC it should be recognized rational to use broad-spectrum antibacterial drugs such as ampiox, ampicillin, doxycycline, cephalosporins of the 2nd and 3rd generations, etc. for 5 to 6 days after the drainage removal. If an infection develops the preventive therapy should be replaced by an adequate therapy in accordance with the pathogen sensitivity.     

Characterization of hydroxyl radical-induced damage after sparsely and densely ionizing irradiation

The extent of hydroxyl radical mediated cell inactivation was measured for a variety of particle beams ranging from 8.5 Me V/u neon ions to 570 Me V/u argon ions. In general, the fraction of the total radiosensitivity caused by OH decreases from close to 60 per cent at low ionization density or low linear energy transfer (low LET) to close to 25 per cent at high LET for aerobically irradiated mammalian cells. The extent of OH induced cell lethality can be explained in terms of LET infinity only for low energy or low atomic number particles where fragmentations and complicated track structures do not contaminate the characteristic particle LET. For example, at a calculated LET infinity of 100 ke V/micron, the OH mediated fraction of the total radiation damage is about 25 per cent for low energy carbon but close to 40 per cent for high energy carbon ions. For low energy charged nuclei of approximately the same energy, as the 5.4-13.4 MeV/u He, Li, C and Ne ions in this report, there is a predictable diminution of the OH mediated effect with increasing LET infinity; however, the biological effect cannot be predicted accurately from calculated LET infinity values for high energy particle irradiation, nor indeed from a variety of low energy charged particles of quite different energies (incident velocities). This illustrates the unsuitability of using LET as a unifying parameter, except under specific circumstances. As more is learned about the energy deposition for energized charged particles in terms of track structure (core and penumbra), it may be possible to characterize the radiobiological data with a better physical parameter than LET infinity.     

Behavior of a viscoelastic valveless pump: a simple theory with experimental validation

Background  

A valveless pump generates a unidirectional net flow of fluid around a closed loop of soft viscoelastic tubing that is rhythmically compressed at one point. The tubing must have at least two sections with two different stiffnesses. When a short segment of the tube is squeezed asymmetrically at certain frequencies, net flow of fluid around the loop can occur without valves.     

STUDIES ON THE CROSS-STRIATION OF THE INDIRECT FLIGHT MYOFIBRILS OF THE BLOWFLY CALLIPHORA

1. The cross-striation in the indirect flight myofibrils of Calliphora has been studied by phase contrast and polarised light microscopy. The band pattern at rest-length has been determined in flies killed in osmium tetroxide vapour while their wings remained in the resting position. All other observations have been made on unfixed fibrils. Although length changes in situ are probably very slight (about 2 per cent), isolated fibrils, by treatment with crude muscle extract or with ATP, can be induced to elongate to 104 per cent rest-length, or to shorten by 8 per cent but no more. Over the range 98 to 104 per cent rest-length, experimentally induced length changes are reversible. The fibrils can also be stretched beyond 104 per cent rest-length, but the process is irreversible. During the course of glycerol extraction the fibrils elongate to 104 per cent rest-length. 2. The changes in band pattern observed over the range 104 to 92 per cent rest-length are qualitatively the same as the changes observed over a wider range (about 130 to 40 per cent rest-length) in the skeletal myofibrils of rabbits. The earlier stages of shortening appear to be effected by retraction of the I bands into the A bands where they fill up the H zones. No evidence has been found that any changes in band pattern are due to a migration of the A substance. 3. Two components of the sarcomere can be extracted from it and a third component remains behind. These three components, which have also been demonstrated in skeletal myofibrils of the rabbit, where they behave in the same way, are: (a) the A substance which does not change its position as the fibril changes its length, and which can be extracted by the same procedures as remove myosin (shown elsewhere to be the A substance) from rabbit fibrils; (b) a material which extends from the Z lines to the borders of the H zone and which moves inwards during contraction and outwards during elongation; it can capture rabbit myosin from solution and form with it a contractile system, and it is thought to be actin; (c) a "backbone" or stroma bearing Z and M lines. 4. Since all these features of the cross-striation are the same in the insect fibrils as in rabbit fibrils, it is considered very probable that the sarcomere is similarly organised in both types of muscle and contracts by essentially the same mechanism.