Neurologic complications of gas myelography by the lumbar route.

Gas myelography is not a new technique, but its acceptance in neuroradiologic diagnosis has been relatively recent. Previously reported series have emphasized the benign nature of this technique and the lack of significant accompanying complications. From a series of 174 gas myelograms performed during a four-year period, two reports are presented wherein transient exacerbation of neurologic deficit followed exchange of cerebrospinal fluid and gas under pressure by the lumbar route. One patient with cervical spondylotic myelopathy experienced an increase in paresis, while another was found to have marked fasciculations. Speculation regarding possible mechanisms involved with these complications is presented. It is suggested that exchange of cerebrospinal fluid and gas under pressure via the lumbar route be used with caution in those patients with compromised cervical spinal cords.


Cultural differences in hemisphericity: a critique.

A series of four articles on the "other side" of the brain has been published in this journal by Dr. Joseph Bogen and his colleagues (1, 2, 3, 4). The first three of these are rapidly becoming minor classics for those of us interested in hemispheric specialization. However, the fourth article reports a combination of sociologic and neurologic observations which, in our opinion, are misinterpreted. This misinterpretation stems primarily from the use of inappropriate statistical procedures and the misleading characteristics of a variable which is comprised of a ratio of two other variables (i.e. the A/P ratio). In short, we argue that the sociologic data presented (4) are not consistent with the constant sum model of hemisphericity discussed in that paper. An alternative model is discussed.


Supplemental sensory feedback for the VA/NU myoelectric hand. Background and preliminary designs.

Methods for realizing three SSF systems for the VA/NU myoelectric hand have been shown. In some cases, estimates concerning amputer acceptance, and references relating to improvements in function, were made. These estimates are purely speculative, and are not intended as a substitute for accurate information which can only be obtained by complete laboratory evaluations of the SSF system codes and by placing the systems on subjects. At this time, it appears that all three of the systems are technically feasible, and that they could be made clinically practical through careful design.


[Apparent cardiac malformations in old age].

In patients aged 79, 80 and 81 cardiac malformations were found at autopsy which did not permit to decide with certainty whether they were congenital or acquired. In the first case the lesions appeared as a band-shaped fibromuscular subvalvular aortic stenosis, the second one being an isolated aneurysm of the membranous septum directed to the righ side and combined with a minute diverticulum in the muscular part of the interventricular septum. The apex of the aneurysm faced the septal cusp of the tricuspid valve. From its dorsocranial circumference two tunnel-like formations projected in the dorsocranial direction terminating blindly beneath the atrial septal endocardium. The ventral canal protruded into the right, the dorsal one into the left atrium. Rather marked regressive changes and areas of florid chronic inflammation were found in the terminal parts of these channels. In the third case observed the pathological lesion were aneurysms of the Valsalva sinuses.


[The course of healing of cutaneous wounds in young and old rats].

Healing of cutaneous wounds produced on the backs of young and old rats has been compared at ten various intervals between days 3 and 28. The only differences disclosed pertained to the exsudative and proliferative phases between days 3 and 5, which were found to develop more rapidly in young rats. The phase of the (predominantly afibrillar) connection of the wound stumps was reduced to less than 5 days. The exact nature of the "sticking" intercellular substance has not been clarified; most probably the substance represents nonfibrillar collagen. In the group of old rats neoformation of fibrillary neocollagen was somewhat more marked during days 7 to 9 than in yound rats, in whom a rather pronounced exsudative component was found during that period. No significant differences between the two groups were disclosed during the later stages of the experiment. Fibroblasts participated in collagen phagocytosis during the definitive reconstruction of the provisional, imperfectly oriented fibrillar connection of the wound edges.


[Familial malignant melanoma].

Two families with a familiar occurrence of malignant melanoma have been described. In the first family malignant melanoma has been histologically verified in two generations. In the other family, malignant melanoma occurred in four generations, but it has been verified histologically in two of them only. In the remaining two generations there were positive anamnestic data.


[The ultrastructure of bovine lymphocytes in chronic lymphocytic leucosis].

The morphology of blood lymphocytes as obtained from cows suffering from chronic lymphocytic leucosis (CLL) and from healthy control animals was studied with the electron microscope. In the leukemic lymphocytes there was a significantly higher occurrence of the so-called nuclear pockets (13.8 per cent in the healthy ones). Marking the surface of the lymphocytes with Rutherium Red permitted to discern between two distinct populations of lymphocytes in peripheral blood. By using this method, B-lymphocyte were shown to prevail in CLL, accounting for 89.7 per cent of the total lymphocyte count.


[Mesothelial polyp of the epicardium].

In an autopsied male aged 31 who had been suffering from chronic bronchitis, a polyp anchored at the site of the crossing of the aorta with the pulmonary artery was found in the pericardial sac. Histologically, the polyp was classed as benign mesothelioma.


[Mesenchymal neoplasms of the skin. (A normative study)].

On the basis of a retrospective study of a large bioptic material, a scheme for a histological classification of mesenchymal cutaneous neoplasms has been suggested. The scheme as proposed here has been discussed and compared with the elaborations of WHO (1,2) and those of AFIP (3,4).


Ultrastructural characterization of the interphase nucleus of Gonyostomum semen.

The interphase nucleus of the chloromonadophycean alga, Gonyostomum semen (Ehrenberg) Diesing, has a highly distinctive appearance. Interphase chromatin is readily distinguishable in both light and electron microscope preparations. It extends throughout the neucleus and frequently makes contact with the nucleoli and with the nuclear envelope. Among the chromatin filaments are large numbers of 35-46 nm diameter granules which occur singly or in clusters. The nucleoli are characteristically located in the posterior half of the nucleus and are composed of granular and non-granular components. Nuclear pores occur in slight depressions of the nuclear surface; their lumen has a diameter of approximately 75 nm and contains electron-dense material. The chromatin and the large numbers of nuclear granules are unusual and warrant further investigation.


On formation of melanosomes in a cultured melanoma line.

Melanosomes are present in abundant numbers in HPM-73 melanoma cells maintained in surum-containing cultures. However, withholding of serum for 3 days caused severe retardation of development of these organelles. Addition of chondroitin-4-sulphate (0.4 mg/ml) to serum-containing culture media for 3 days resulted in greater numbers of premelanosomes and melanosomes relative to mitochondria. The same amount of chrondroitin-4-sulphate (0.4 mg/ml) added to serum-free cultures also resulted in an increased ratio of premelanosomes and melanosomes to mitochondria but, within the 3-day period many of these organelles did not attain the pattern of maturity evident in melanoma cells reared in serum-supplemented media. By exploitation of slowed rates of development of melanosomes in cultures (especially, but not exclusively, in serum-free samples) it was possible to examine various early developmental forms of these organelles. It was found that in this cell line mitochondria appear to be involved in the process of melanosome formation.


Carcinogenesis: a late effect of irreversible toxic damage during development.

Intrauterine and early postnatal life are periods of exceptionally high susceptibility to certain kinds of chemical carcinogens. The most potent known transplacental carcinogens are direct acting alkylating agents. Most nonreactive compounds, which require enzymes for metabolic conversion into chemically reactive "proximate carcinogens," are less effective because the required enzymes are present at low levels in the fetus, and many proximate carcinogens are too reactive to reach the fetus when formed in maternal tissues. Despite this, many carcinogens which require metabolic activation are very active transplancentally, as the intrinsic susceptibility of rapidly dividing fetal cells compensates effectively for comparatively low tissue levels of reactive metabolites. Transplacental carcinogens of all kinds are most effective late in gestation, generally after organogenesis has begun and after the period of greatest susceptibility to teratogens. Only a small number of known carcinogens have been tested for transplacental carcinogenic activity. The great majority of tumors induced transplacentally in the well-studied rodent and lagomorph species (mouse, rat, Syrian hamster, and rabbit) have morphologic features of adult, rather than embryonal, tissues. A given agent tends to induce in a given species largely the same types of tumor when given transplacentally as when administered directly to postweaning animals, unless its carcinogenic effect in the latter is ascribable to some peculiarity of distribution, metabolism, or physiology. In a second species, the spectrum of tumors induced either before of after birth may be quite different. For bioassay of suspected carcinogens, the significance of perinatal carcinogenesis lies in the facts that the fetal and preweaning rodent is an extremely sensitive indicator of carcinogenic activity, and that the facile adaptibility of fetal cells to tissue culture and their rapid expression in vitro of properties of neoplastic transformation make possible a rapid in vivo/in vitro screening system for chemical carcinogens.


Molecular biology and biochemistry of differentiation.

Recent work in the field of molecular biology and differentiation has been directed towards an assessment of the number of different genes involved in the development and differentiation process. By the techniques of RNA-DNA hybridization to single copy DNA, it appears that some 60,000-200,000 different RNA sequences are expressed during embryonic development in the mouse. The differentiating brain shows the highest degree RNA transcription diversity. The new technique of cDNA-poly(A)-containing RNA hybridization is described. The nuclear poly(A)-containing RNA appears to reflect the high complexity of sequences as determined in RNA-DNA experiments described above. The cytoplasmic poly(A)-containing RNA or messenger RNA appears to represent a subset of approximately 10-20% of the information in the nuclear poly (A)-RNA. Also, the major portion of frequency class of messenger RNA in different organs such as kidney, spleen, and liver are common to these different organs. However, brain, although containing many of the cytoplasmic messenger RNA sequences found in liver, kidney, and spleen, has a large class of messenger RNA sequences which are specific to the nervous system.


Techniques for assessment of teratologic effects: embryo culture.

A simple method is described for growing rat embryos in vitro for 48 hr from head-fold to early limb-bud stages at rates of development and protein synthesis indistinguishable from those in vivo. Culture of the embryos can be continued for longer periods but at a reduced growth rate. Preheating the culture serum to 56 degrees C for 30 min improves embryonic development, but raising the culture temperature 2-3 degrees C or exposing the presomite embryos to 20% O2 (160 mm Hg) causes malformations, particularly of the brain and spinal cord. The value of such culture methods for teratology is briefly discussed.


Techniques for assessment of teratogenic effects: developmental enzyme patterns.

Most studies designed for assessing teratogenic effects focus on only three of four types of final manifestations of abnormal development; namely intrauterine death, malformations, and growth retardation. Developmental toxicity evaluations generally do not include functional deficits. Current techniques are inadequate for assessing functional capability during perinatal development, and there is a need for improved measures. Thus, measurement of developmental enzyme patterns is proposed as an approach that directly evaluates acquisition of metabolic competence of fundamental organ systems. During ontogenesis most organs acquire their full complement of enzyme activities in a programmed sequence which corresponds to attainment of complete functional capability. The usual alterations in enzyme activity that characterize these patterns occur at one of three time periods, namely, late fetal, early neonatal, or late suckling. Qualitative or quantitative changes in these patterns at any time by one or more key enzymes of a tissue could be indicative of developmental toxicity. Factors are outlined relating to consideration of developmental enzyme profiles as indices of maturation capable of reflecting the action of toxic agents. This presentation: (1) reviews the current state of the art for evaluating effects on development, (2) considers the applicability of enzyme patterns for biochemical assessment of development, (3) characterizes the target tissues and those metabolic pathways and/or specific enzymes most sensitive and adaptable to practical toxicity evaluations, and (4) describes the steps being taken to validate this system. The ultimate objective of this approach is to determine whether alterations in developmental enzyme profiles will provide a technique with improved capability for assessing developmental toxicity.


Techniques for assessing teratogenic effects: epidemiology.

Epidemiologic studies of malformations can aid in the understanding of human teratogenesis. Employing a variety of approaches epidemiology can develop or test hypotheses concerning possible causes or through surveillance provide data useful for a variety of purposes. Drawing heavily upon our experiences at the Center for Disease Control, this paper reviews some concepts and uses of epidemiology in studies of human teratogenesis.


Studies in adaption to ambient oxidant air pollution: effects of ozone exposure in Los Angeles residents vs. new arrivals.

To test the hypothesis that adaptation protecting against acute effects of ambient ozone (O3) exposures develops in Los Angeles residents, human volunteers were exposed to 0.4 ppm O3 under conditions simulating ambient pollution exposures. Blood biochemical, pulmonary physiological, and clinical responses were assessed. Los Angeles residents (N = 6) showed only minimal clinical or physiological response to O3, while new arrivals (N = 9) showed significant losses in pulmonary function and a tendency toward increased symptoms. Most biochemical responses did not differ significantly between residents and new arrivals. These results agree with others in suggesting that exposures to elevated ambient concentrations of O3 produce adaptation in a least some residents of photochemical pollution areas. The underlying mechanisms and long-term consequences of such adaptation are unknown.


Comparative developmental aspects of selected organ systems. II. Gastrointestinal and urogenital systems.

A brief description of the basic patterns of mammalian organogenesis of the gastrointestinal and urogenital systems is presented based on events as they occur in human beings. The emphasis is not on the details of this development, but rather on its organization and timing, with tables of comparative development providing a comparison of similar events in man, rat, mouse, and chick.


Behavioral testing as a method for assessing risk.

Behavioral effects have been found to result from the prenatal administration of substances known to be teratogenic to the CNS. These effects occur at dose levels lower than those producing gross malformations and when the agent is administered at times other than that optimal for CNS relevant technique for detecting adverse consequences of prenatal exposure to drugs and chemicals. Behavioral testing, however, also appears to have attributes that dictate a thoughtful approach to its role as a method for assessing risk, and additional research is needed to obtain usable techniques. The need for such research is intensified by the present inability to identify potential behavioral teratogens by means other than laboratory investigation.


Research strategies for behavioral teratology studies.

Several compelling aruguments have been advanced in support of expanding the use of "behavioral teratology" evaluations as routine components of toxicologic screening procedures. As a basis for development of effective behavioral teratology screening approaches, a conceptual framework is presented which interrelates: (1) changes in relative functional brain capacity with age, (2) possible times and durations of exposures to environmental insults, and (3) various types of toxicity testing procedures carried out at appropriate time points in relation to different exposure period. Within the context, several research strategies for behavioral teratology studies are concisely posed and evaluated. These include: (1) clinical hypothesis testing, where particular effect(s) of a given agent are evaluated based on hypotheses derived from clinical or epidemiological observations; (2) comprehensive screening approaches, where multifaceted, long-term longitudinal neurobehavioral evaluations are employed to assess whether any of a large number of possible deletarious effects are exerted by an agent and at what threshold exposure levels; (3) alternative screening heuristics, by which adequate assessments of neurobehavioral toxicity of various agents may be accomplished without completion of more exhaustive, but also more expensive and time-consuming comprehensive screening protocols.


Assessment of current test procedures.

The belief that screening tests for teratogenicity are of low predictive value has many supporters who point to the inconsistency with which malformations are induced. However, to fault the test systems when such inconsistency is predictable from both the inherently unstable nature of a malformation and from fundamental principles of teratology, is unrealistic, and, as is shown, perhaps the greater faults lie with the critics. It is suggested by examples that, if attention was concentrated not on the inconsistent malformations but on more consistent embryopathic effects which in one form or another are always associated with malformations, the predictive value of the screening tests would appear in a more favorable light. Thus, even if malformations are not demonstrated, the range of conditions (dosages) in which they might occur can be determined. Such information, used in conjunction with that obtained from other preclinical studies, can then form a reasonably sound basis for extrapolation to man.


The foot-and-mouth disease situation in Iran.

Foot-and-mouth disease has been known in Iran since long ago. Typing of virus was done in 1950 at Mérieux Institute and since 1959 at Razi Institute. Type Asia 1 was isolated three times: in 1957, in 1964 and in 1973. In June 1962, FMD type SAT 1 entered Middle-Eastern countries; it was soon controlled, and completely eradicated by the end of 1963. At the present time, endemic types of FMD cause limited and sporadic outbreaks in some regions of Iran; their incidence is lowered every year. Except the endemic types A and O, all other types in Iran are considered as exotic. The control measures are: 1) stamping-out policy against exotic types, 2) mass-vaccination of all healthy susceptible animals by a polyvalent vaccine, 3) regular disinfection of premises and utensils, 4) strict application of sanitary measures.


[Occurence of foot-and-mouth disease in Senegal].

From December 1975 to October 1976, 13 outbreaks of foot-and-mouth disease were studied in Senegal. The virus, SAT2, identified at Pirbright, was in all probability brought from Mali or from Mauritania by transhumant animals or animals imported illegaly. The disease, which attacks bovines, evolved in its rough form without lethality. Treatment was symptomatic. Only vaccination of imported breeding stock and draught animals was decreed.


An assessment of the current status of foot-and-mouth disease in Nigeria.

Foot-and-mouth disease has been widespread throughout the country in recent years. The disease occurs mainly in cattle though spillover of infections has been observed in sheep and pigs. Virus types A, SAT 2 and SAT 1 are the usual cause of outbreaks. The present field control method is a 6-monthly vaccination schedulae for animals in government ranches, the few semi-commercial ranches and piggeries as well as for other valuable animals and exotic animals of high production quality. Arrangements are under way to institute a strict and more comprehensive control programme against the disease in view of the envisaged expansion of livestock development projects and improved zoo-sanitary status projected for our 3rd National Livestock Development Plan. A national policy of a barrier and frontier vaccination programme supplemented with strategic vaccinations in vulnerable foci is here recommended and discussed on the basis of a survey on the present status of the disease.


Trends in freeze-drying equipment and materials.

The above discussion outlines some trends seen in the development of equipment for freeze-drying of various biological-like products. It has been pointed out that many similarities in equipment now exist. There are still areas in which a consensus on best design has not been reached and in these areas the user is offered some clear choices. Various changes have been introduced in recent years into freeze-drying equipment principally in an effort to increase reliability and improve the quality of the product produced. It is probable as more products are freeze-dried (and particularly as these products become more cost-sensitive) that manufacturers will also require that greater performance-capability be built into their equipment. This may perhaps translate into requirements for carrying high peak-vapor-rates and for automatic control in an effort to reduce drying cycles and increase throughput in a given machine.


Freeze-drying equipment.

Illustrated presentation of a sophisticated research freeze-drying apparatus, fitted with many controls including a program controller. With this machine, it is possible to remove samples from any part of the chamber, at any time, without interfering with the freeze-drying process. By this ability to sample, the apparatus makes it possible to study, during the freeze-drying process, the influence on the dried product of many parameters and to reproduce in the chamber the same drying conditions offered by the production-scale machines. The figures include one of a production-scale machine, and a patented device for automatic loading and unloading of the freezers and the freeze-dryers.


Rubber closures for freeze-dried products.

Once a biological product has been developed to perform its required medical or pharmaceutical function, it is essential that a container-closure system by chosen which will preserve the efficacy of the product up to the point of administration. The general requirements applicable to proper closure function will be reviewed and the suitability of natural and synthetic elastomers to perform these functions will be discussed. The specialized application of elastomeric materials as closures for freeze-dried products presents additional requirements which are superimposed upon those previously discussed. The first of these unique considerations relates to the proper physical design which will permit the outgassing of water vapor during the sublimation step in the lyophilizing chamber. During this outgassing the design must also permit the closure to remain affixed in the neck while only partially inserted. Since these preparations are lyophilized because they are unstable in aqueous solutions, the elastomer used must constitute an effective barrier to the transmission of moisture vapor through the closure. The MVT and gas transmission properties of elastomers will be discussed. Special consideration will be given to the extremely low temperatures used in the sublimation, stoppering, and storage before use of lyophilized products. The phenomenon of glass transition points with different elastomers will be explained as its relation to satisfactory performance of the closure function at low temperatures.


Some problems in sealing gas-filled glass ampoules.

We have studied recently the ends of hand-sealed and machine-sealed, gas-filled ampoules of borosilicate glass. The hand-sealed ampoules were of two types: tip-sealed and draw-sealed. The openings in the tip-sealed ampoules were estimated to range from 5 to 10 mu; in the machine-sealed ampoules the helix-like openings were less than approximately 10 mu. From the dimensions and nature of the openings we conclude (1) that the usual, simple methods used to test for "leakers" are not successful for small bore channels because pressure differences are less than one atmosphere and the test-time period insufficient, (2) that the failure of ampoules to seal may be due to the physical properties of glass and if this is so, ampoules containing liquid or freeze-dried preparations under gases cannot be sealed completely by ordinary means, and (3) that complete, satisfactory sealing can be done by dipping the ends of the ampoules into an elastomer solution which when cured provides an effective barrier even when stored at -70 degrees C for 12 months.


On the adequacy of the draw-sealing of gas-filled glass ampoules.

It is recommended that a very clear distinction be made between draw-sealed and tip-sealed glass ampoules. We would, that is, defend the draw-seal for its proven value and its demonstrated freedom from microscopic channels. Where tip-sealing is still employed, we would suggest its reevaluation. Little more can be said in the absence of an immediate reason for the differences in the behavior of the glass in the course of the two procedures. Others may be able to explain the persistence of the capillary in the tip-seal in physico-chemical terms. As to balloon-seals, the third "variety" in common use, it would seem that their characteristics must derive from the way they are made. Ballooned tip-seals appear to have been shown by Greiff et al. (1975) to suffer the same shortcomings as the simple tip-seal. Where a draw-sealed ampoule is heated at the tip after the completion of the seal, a ballooned end would seem to have to retain the true seal effected in the draw process. It is perhaps sufficient to let the subject rest with a reassurance as to the adequacy of the common draw-seal.


The importance of storage temperature to the quality of freeze-dried biological products.

Several important practical steps are recognized in the process of freeze-drying of biologic material. The first of these is the selection of conditions optimal for the stability of the substance at the normal storage temperature, usually +5 degrees C. The second step involves the collection of material, storage at some choice freezing temperature (preferably around -20 degrees C) until use. The third step consists of the freeze-drying process itself, with preliminary freezing at another temperature, usually between -60 degrees and -80 degrees C. How these steps affect the quality of biologic products, proteins and polysaccharides has been the subject of study in our laboratories. The results have led us to the conclusion that molecular rearrangements occur at certain critical frozen temperatures which, in combination with time, leads to inactivation in some cases, stability in others. Such critical temperatures can be measured for other products and systems.


Parameters to consider in the selection and purchase of a freeze-drying system.

When considering the purchase of a freeze-dryer, the user must establish his own performance standards and particular requirements for the following reasons: 1. Large monetary investment required for the purchase, operation and maintenance of the equipment. 2. The expense and stability of the products to be freeze-dried. Some of the basic parameters that must be considered: 1. Product requirements, such as volumes, optimum temperature, and vacuum limits. 2. Facility restraints relating to the availability of space, and utilities. 3. Return on the capital investment (ROI) 4. Technical competence of operating and maintenance personnel. When the parameters are established, the buyer is prepared to purchase a freeze-dryer to best suit his needs. Precise cycle development, reliable hardware and personnel training, assure productivity and product quality.


Review of United States requirements for residual moisture in drugs.

Officially recognized procedures for residual moisture determinations on biological products are described. These include gravimetric at ambient temperature and thermogravimetric analysis at specified temperatures for specific products. The bases for selecting the optimum residual moisture for a new product are discussed and values established for currently licensed products are listed. Comparisons are made between the procedures and requirements for biological products and the water determinations specificed in U.S. Pharmacopeia XIX.


Moisture analysis of lyophilized allergenic extracts.

A simple, relatively fast, coulometric method to determine both the surface-moisture and bound-moisture content of a wide variety of lyophilized, allergenic extracts has been developed. The method has been found suitable for the detection of residual-moisture levels in both lyophilized protein and carbohydrate samples. Isothermal rate-changes in moisture desorption, normalized with respect to sample size and plotted versus time, yield desorption curves which are characteristic of several individual classes of lyophilized materials. The method, when compared to the Official Loss on Drying Procedure for Lyophilized Biologicals, has proven to be faster (1.5 hr.) and more sensitive, with increased specificity and accuracy.


Numerical analysis of heat and mass transfer during freeze-drying.

The transient-state external heat and mass-transfer during freeze-drying was investigated. The spaces between the heaters and porous product-surfaces were simulated as semi porous channels, with mass-injection into the channels from the sublimation of ice. The energy, vorticity, concentration, and stream function/vorticity equations were the governing equations used as the mathematical model. These partial differential-equations were solved by finite-difference, numberical methods. The Fromm, Alternating Direction Implicity, and Upwind Difference methods were used in solving the parabolic equations; and the Successive Over Relaxation method was adopted to solve the elliptic equation. Numerical solutions obtained from the digital computer for the external heat and mass-transfer during freeze-drying were computed for Reynolds numbers equal t0 0.1, 1.0, and 4.0 and Grashof numbers equal to 0, +/- 100, and +/- 1000. The Prandtl number selected for water vapor was 1.0. One set of these solutions were compared to a known, analytical solution, and good agreement was obtained. The external heat and mass-transfer mechanism was then combined with the internal-heat-transfer mechanism developed by Dyer and Sunderland (1968), and the equations describing the relation of heater temperatures and product surface-temperatures developed by Massey and Sunderland (1972). A thorough computer-simulation was carried out for the combined heat and mass-transfer mechanism during freeze-drying of food products.


Freeze-drying today and tomorrow.

The freeze-drying process and equipment have been improved over the years; the cycle times have shortened and the dried products have improved as a result. This talk will deal with these improvements and how we have progressed from the early systems to where we are today. Such areas of discussion will include: vacuum pumping systems, how they are sized and designed to meet the needs for general and special applications; heat transfer systems, and their use in maintaining the drying profile; condensing surface design, and what is best for certain types of dryers; controls and instrumentation, and how these have played a big part in the drying process and have made it possible to get repeatability; refrigeration systems, and the part they play in the performance of freeze-drying; and lastly the effect of internal stoppering, bottomless trays, and other items such as these have had on the present state of the art. It goes without saying that there have been many changes and there will continue to be changes and we shall endeavor to look into the future--as to what might well bo some of these changes. Included in the talk will be a number of slides and illustrations to point out the various items as they are discussed.


Sublimation of formaldehyde in freeze-drying.

Formaldehyde solution, commonly used to inactivate bacterial, rickettsial and viral suspensions during the preparation of vaccines, is known to have a deleterious effect on many antigens during freeze-drying. Sublimation of formaldehyde in shell-frozen and plug-frozen aqueous samples was investigated by measuring the residual formaldehyde periodically during the freeze-drying procedure. It was found that formaldehyde, even while subliming, concentrated on a volume basis. This was more apparent with the plug-frozen than with the shell-frozen material. Moreover, in the preparations taken to dryness, the formaldehyde polymerized to form paraformaldehyde. It was found that the addition of methanol not only prevented polymerization, but also significantly increased the sublimation of formaldehyde without concentration of the latter.


A new freeze-drying technique for processing biological materials.

Wet granulation and dry blending are standard techniques used in tablet formulation. Both techniques impose limitations on the ability to produce homogeneous tablets with rapid dissolution and controllability of the matrix for active ingredients. This report describes the development and application of a new freeze-system using a swirling bath of Freon-12 to process sensitive biological materials. The frozen beads produced with this process are subsequently freeze-dried and may be used to produce precise tablets. The ultra rapid freezing (7-14 milliseconds) provided by the Freon-12 process yiels amorphous homogeneous spheres by retarding component migration which permits precise control of pH and redox potential in the final product. Dissolution of tablets prepared by this Du Pont process is so rapid (8-12 seconds) that a special testing technique is required for measurement of dissolution time. Improved recoveries of activity have been demonstrated for sensitive biological materials compared to conventional freeze-drying. The optimization of droplet sizes is controlled by injection rate, stream diameter and surface velocity of the Freon-12 bath. Droplet size control permits attainment of weight precision in the range of 0.6 +/- 0.06% for a final 50 mg tablet. This compares with a tablet weight precision of 1% to 2% typical of dry blending and wet granulating. Potential applications of this technology include pharmaceuticals and the production of ultra precise reagent tablets for the Du Pont Automatic Clinical Analyser.


Long term storage studies with a new stabilised formulation of yellow fever virus vaccine.

A new formulation of yellow fever virus vaccine incorporating a stabiliser has been prepared which is very much more stable than conventional unstabilised vaccines. This vaccine has a half life of 2-4 years at 4 degrees C, 9 months at 20 degrees C and 10 days at 37 degrees C. Its greater stability should have considerable advantages, especially when it is used in tropical countries.


Freeze-drying of a purified human diploid cell rabies vaccine.

A rabies vaccine prepared in human diploid cell strains was purified by continuous-flow sucrose density gradient centrifugation. The peak fractions containing 35-40% sucrose were diluted with a stabilizer consisting of degraded gelatine in a Tris-EDTA-buffer, and then inactivated with beta-propiolactone and freeze-dried to a residual moisture of approximately 2.5%. This vaccine was stable as proved by accelerated stability tests.


Stability of live, freeze-dried virus vaccines.

Stability of live, freeze-dried vaccines is a major factor for successful vaccinations. Vaccines may be stored at -20 degrees C or less for long periods without loss of activity and this storage does not affect stability during subsequent storage. Storage in the refrigerator for long periods is harmless for certain very stable vaccines such as influenza, rubella, NDV, Marek's. Other vaccines, such as IBV, show a significant loss in titer after 2 years. The routine use of an accelerated stability test, e.g. exposure of each lot manufactured to 37 degrees C during 7 days, provides useful information regarding the stability of the vaccine at +4 degrees C. In general the loss during the accelerated stability test is higher than the loss after 24 months storage in the refrigerator. Specifications requiring that each vaccine lot must possess, after the accelerated test, a titer equal to or higher than the minimum titer needed for immunization, are a guarantee of sufficient potency at the time of administration. To solve the problems in tropical countries stable vaccines are essential. Cendevax and Rimevax exposed to tropical temperatures still possess the minimum required titer after several days.


Stability characteristics of freeze-dried human live virus vaccines.

Freeze-drying (lyophilization) of biologically active materials such as human live virus vaccines is an accepted method of preserving potency. Since freeze-drying does not assure total stability, a formal system of monitoring stability, i.e., potency, has been established. Two experimental desings are utilized: (1) Long term studies to duplicate normal use storage at -20 degrees C and 2-8 degrees C and (2) Accelerated studies which predict long term stability through regression analysis using the Arrhenius equation. Data summarizing stability experience over a long period of study will be presented.


The production and use of rinderpest cell culture vaccine.

Description of preparation, safety and efficacy testing of a rinderpest cell culture vaccine which is observed in lyophilized form and should be used within two hours following its reconstitution. Excellent results have been obtained with this vaccine in Kenya, Uganda and Tanzania.


Methods for determining favorable conditions for freeze-drying biological reference materials.

By predetermining favorable conditions for freeze-drying samples through pilot runs, one can gain more assurance that relatively large batches of lyophilized biological reference materials produced have the desired characteristics. Included in the pilot studies are the determination of the characteristics of the lyophilizer with a specific freeze-drying cycle, simulation of the water load expected for the production run, residual moisture analyses of the lyophilized samples, and biological activity of the samples before lyophilization and after exposure to elevated temperatures. Various reference materials have been lyophilized by these procedures. Among them are clinical chemistry reference samples, bacterial suspensions, and candidate serum-protein reference immunological standards. A batch of 6,300 vials of the latter was successfully freeze-dried and showed less than 0.1% residual moisture; different proteins (including complement) were both functionally (enzymatically) and antigenically active.


Freeze-drying of spermatozoa.

Bull semen was diluted to a concentration of 2 X 10(8) cells/ml, cooled to 5 degrees C in 5 h, frozen in 0.025 ml spheres on the surface of solid carbon dioxide, and stored in liquid nitrogen. 50% by volume of the diluent was 325 m0sm Tes:N-tris (hydroxymethyl) methyl-2-amino ethane sulfonic acid titrated to pH 7.2 with 325 m0sm Tris:tris (hydroxymethyl) amino methane. The diluent also contained 30% by volume isotonic sodium citrate and 20% by volume egg yolk. The frozen spermatozoa were freeze-dried in 400 mg quantities in test tubes at -50 degrees C with a condenser at -196 degrees C. Moisture content was determined by weighing the individual samples before and after freeze-drying. Drying the samples for several days at 20 degrees C removed 868 mg from each gram of frozen material and this was considered the zero moisture level. Samples were stored at 20 degrees C or -196 degrees C after freeze-drying. The freezer-dried samples were rehydrated by flooding with five times their original volume of isotonic sodium citrate. Tests of the recovered spermatozoa included percentage motile cells, acrosome damage, enzyme release, protein denaturation, hypotonic swelling and fertility testing. Sperm motility decreased with dryness until it reached zero at 3% moisture. Acrosome morphology and enzyme release appeared normal down to 1% moisture. Preliminary results showed some fertility at all levels of dryness with -196 degrees C storage, and fertility at less than 1% moisture with 20 degrees C storage. Additional fertility testing is underway.


Freeze-drying of histocompatibility typing sera.

This report describes a unit employed for the freeze-drying of histocompatibility typing sera using a 50-h cycle. The unit will process approximately 3,200 3-ml vials with a final residual moisture content of less than 2%. The system employs dry ice-alcohol cooled circulating baths to maintain the condensers below -60 degrees C, and two shelf-cooling baths to maintain the product at the required temperatures during the freeze-drying process. The results of a recently conducted 5-year study of the effect of residual moisture as a function of time and storage temperature are also included. Studies conducted to date indicate that with residual moistures below 2%, freeze-dried histocompatibility sera can be stored at +4 degrees C without the loss of significant tissue typing factors. Solubility of all serum was lost when samples were stored at +37 degrees C or higher during this same 5-year period. The long-term storage studies are being continued.


Biological standards: problems in large-scale production.

A biological standard usually consists of a batch of perhaps several thousand ampoules. In defining a batch of ampoules to be a standard, we are in essence making a number of fundamental claims: (1) That in terms of content, (mass and potency) each individual ampoule is identical to every other amoule in the batch. (2) That in the  course of preparation of the standard, the contents of each ampoule have been treated in exactly the same way and held for the same length of time under the same conditions, (i.e. all the ampoules of the standard have been treated as one single batch, each stage of processing being carried out under constant conditions in one complete working session, however long). (3) That the stability or instability of the biological activity of the contents of each ampoule of the batch is identical to every other ampoule (i.e. that moisture, oxygen, light, raised temperature--all factors which cause deterioration of biological activity--have been exculuded to the same degree in each and every ampoule in the batch, so that each ampoule of the standard is equally stable or unstable). It is quite a difficult task to meet these criteria even in a small number of ampoules at the bench. It becomes a very demanding exercise to achieve the same results in 4,000 ampoules--the normal batch size at NIBSC. Details of the methods used at NIBSC for the production of large batches of ampoules of biological standards have already been published (Campbell, 1974). The author of the papers will take the opportunity to develop various aspects of the published detail.


Research and development of phamaceutical dosage forms.

The development of a suitable formulation and a freeze-dry cycle for a pharmaceutical dosage form requires knowledge of some basic properties such as (1) eutectic temperature, if one exists, (2) temperature effect on solubility, (3) degree of supercooling, (4) heat transfer properties of the frozen product and (5) equipment design and equipment capability. Basic work with several inorganic and organic salts shows that eutectic temperature is a function of the melting point and the differential heat of solution of a drug. From a knowledge of these parameters, a mathematical expression can be used to estimate eutectic temperature. The desired characteristics which can be achieved by proper formulation of the solution to be freeze-dried and by employing optimum freeze-drying cycles include an intact cake, sufficient strength, uniform color and rapid reconstitution. By utilizing resistivity measurements to determine eutectic temperature and supercooling properties it is possible to reformulate products, increase batch sizes and reduce overall times for freeze-drying cycles.


The physico-chemical basis for the freeze-drying process.

To the extent that the final form and quality of a freeze-dried product depends on the way the freeze-drying is conducted, an understanding of the many factors involved is most important. The numerous effects of the design and mode of operation of the freeze-drying equipment on the course of the process need to be known, as do the properties intrinsic to the material to be freeze-dried. Much can be learned and predicted from the study of the "supplemented phase diagram", a series of experimental plots describing the equilibrium and the non-equilibrium phase behavior of the system in question. Such diagrams map and distinguish eutectic and amorphous phase behavior. Further information is available from gravimetric studies allowing the construction of "desorption isotherms", the plots describing the loss of sorbed water accompanying the sublimation of ice, frequently termed "secondary drying". These plots relate the water retained by the product to the "water activity", or relative humidity at different temperatures. Observations in the freeze-drying microscope contribute additional information, in that they reveal the actual course of the process at the microscopic level. These and other laboratory findings facilitate the analysis and comparison of pilot-plant and commercical scale processing experiences. Where scientific and engineering factors appear to interrelate, the nature and extent of the interdependence can often be determined.


Predicting stability of lyophilized products.

The usual purpose of freeze-drying is to enhance the stability and thus the marketability of a product. Increasing the length of a product's integrity, however, often requires that the formulator be able to predict the extent of that increased shelf life. Based on the Arrhenius principles, techniques are available that can allow such shelf life estimates with an acceptable degree of confidence. The presentation reviews examples of ongoing studies demonstrating predictive techniques as applied to freeze-dried products. The examples cover the most common situations which call for straight-forward and generally accepted principles of prediction; that is, measuring a specific potency loss at several elevated temperatures and then predicting the time for the same loss at normal storage. Other situations, however, as is the case with many in vitro diagnostic products used in clinical laboratories, require a modification of this technique. In those instances, monitoring of the proper "functioning" of samples of a product subjected to exaggerated temperature conditions with an eye to predicting shelf life is reviewed.


Optimization in freeze-drying.

The author assumes that success in freeze-drying must be judged in economic terms. Following a summary of the reasons given for adopting freeze-drying, and an historical outline to explain the changing emphasis in the performance requirements of equipment, desirable features in design and operation are reviewed as the basis for a charter for plant manufacturers and an aid to comparison between different types of plant. Ways of appraising value for money are examined and a novel method is proposed for maximizing throughput by optimising the conditions in the freeze-dryer.


Acute alterations in stroke volume during exercise at 3,100 m altitude.

Following 3 weeks exposure to an altitude of 3,100 m, the cardiac output response to upright submaximal exercise was examined in 3 healthy subjects breathing ambient air and breathing 60% oxygen. The procedure allowed acute alteration of the 2 conditions within a single testing period of 30 min, 60% oxygen breathing either preceding or following breathing ambient air. Cardiac output was also measured in two of the subjects during maximal exercise under these two conditions. Administration of the high oxygen inspirate during exercise had little effect on the level of cardiac output but resulted in an immediate bradycardia and a dramatic increase of approximately 16% in stroke volume. Stroke volumes during maximal exercise were also increased by approximately 10% by the administration of high oxygen. It is suggested that the condition of decreases exercise stroke volume which develops with chronic exposure to altitude may be largely the result of diminished myocardial contractility stemming from a condition of myocardial hypoxia.


Problems of ergonomics in Bali, Indonesia.

Development in Indonesia, particularly in Bali, has been planned and done through several stages of the Five-Year Development Programs, which started in 1969, and emphasized intensification of agriculture and extensification of industries related to potential resources available in the region. In the process, industrialization, being regarded as a prerequisite to higher living standards, brought with it problems concerning safety, health, and work conditions, especially with respect to transfer of technology. As examples, experiences and data, related particularly to ergonomics in the sectors of agriculture, hotel business, textile mills, transportation, and others in Bali, Indonesia, are reported. In dealing with such possible consequences of development, efforts to find fundamental solutions should be given the highest priority. It is necessary to make use of all the existing institutions having potential functions and roles in the policy of development planning, and to take into consideration the factors of safety, health, and work conditions in specifying technical and financial development projects for industrialization.


Effects of industrialization on working schedules.

Recent increase in industrialization has resulted in attention being drawn to diversity of working schedules and their interrelation with content of work. The results of joint research revealed that adaptation to industrial jobs is made difficult because of urban conditions and modern work-control systems, such as workers in flexible-working-time systems who apparently favored regular daily working cycles. Long overtime work in smaller undertakings and the spread of shift systems are two important features of industrial work schedules, each being dominant among skilled and non-skilled jobs. Another important facet is the problem of intra-shift work-rest schedules significant for machine operations and vigilance tasks. It is suggested that phases of work that become intolerable are correlated with unnatural work rhythms. More emphasis should thus be laid on both phase-shifted work and non-self-governing work, the key factor being the relevance of attained data to real work in the whole course of schedules of work and rest.


Ergonomics in traditional Iranian industries.

It is an acknowledged fact that Iranian carpet weavers are subject to excessive fatigue. Earlier investigation has shown this to be largely due to a non-ergonomic body position while working at a traditional loom. It would appear that significantly increased production could be achieved by eliminating or reducing this fatigue. An Iranian engineer has attempted to do this by inventing a metal loom which takes ergonomic factors into consideration. The purpose of this study was to evaluate the effect of the new loom by comparing the productivity of two groups in Kerman, Iran: one using the new ergonomic loom and the other using the traditional loom. In preliminary investigations various factors were taken into account so that the two groups might be considered comparable. After several observations the average productivity of each weaver was calculated (according to knots per day). The results showed that the ergonomic loom had the highest productivity figures for both sexes and that increased productivity was directly related to the degree of comfort of the carpet weavers.


Some observations on the needs of ergonomics in industries in Hong Kong.

The author's interest in ergonomics lies in the common ground it shares with occupational health, since ergonomics aims to make work easier, safer, and more productive and to promote efficiency, comfort, and health. In Hong Kong, owing to lack of natural resources and guaranteed markets, industrialization has not taken a smooth course. Only light industries exist, and one industry flourishes after another. Occupational health and safety tends to be neglected not only by the employers but by the employees. The government becomes the promoter of labor legislation. There is almost no information on occupational diseases. There are some elementary official statistics on occupational accidents. There is practically no research activities on this area going on. There is a very critical lack of occupational health, workers in Hong Kong. Ergonomics may help in improving the present situation because its aims are more positive to the industrialists and the workers who should be converted into educated consumers of ergonomics. In the long run, advancement in occupational health and safety practice will be made.


Application of ergonomic principles in the factories of a developing country.

Several examples of the need for the application of sound ergonomic principles in Singapore factories are presented. Emphasis is laid on the necessity to consider local habits and customs in the devising of ergonomic solutions to occupational health problems. Examples are given concerning vehicle cabin design, difficulties due to climate differences in applying personal protective equipment or in building design, inadequate displays warning dangers, and health consequences of technical improvements, safety measures, or measures to achieve greater efficiency. Sometimes ergonomic practices may promote productivity but be prejudicial to health. In rapidly-changing and cosmopolitan Singapore, ergonomic principles are vital to all facets of manufacturing processes and the transportation and distribution of goods, but ergonomic practice can be complicated by several factors as indicated by such examples.


Ergonomics for occupational hygienists in developing countries with examples from Sri Lanka.

Occupational health problems in developing countries, especially those situated in the tropical zone, are difficult to define. The conditions are more adverse in unorganized small-scale industries. The application of ergonomic principles in the practice of occupational health in developing countries must be subject to all aspects of community health and impact of industrialization as well. Ergonomics offers a broad concept to health scientists in developing countries. "Systems ergonomics" is not applicable. On the contrary, the fact that ergonomics conveys a different meaning to those in developing countries is highlighted by a few examples from Sri Lanka. The author presents his view for consideration in the development of international instruments to prescribe the sale of guarded machinery to developing countries and the limitation of incentive schemes for performing arduous tasks leading to occupational illnesses.


Designed and real working situations in machine systems operation.

New work situations designed at the stage when new machine systems are introduced are realized on the assumption that the new systems can maintain their designed functions consistently, generally eliminating previous work habits and without sufficient knowledge about real working processes and skills. This may produce differences between designed and real working situations. Some examples are presented from observations on influence of modern design of cargo ships on their crews. It was difficult for crews to maintain stable working conditions, especially when machine systems deviated from their designed functions. Often the crew had to work in off-duty hours giving up private freetime activities. Among various factors contributing to the discrepancies between designed and real work, lack of availability of the new systems is the most important factor. Also important is lack of back-up systems which would function either when the machine systems are out of order or when previous working skills and habits must be applied. A need for developing methods of evaluation of these two factors from ergonomic points of view is pointed out.


Shoulder muscle tenderness and physical features of female industrial workers.

Physique, muscle strength, and jump-step scores of female industrial workers, ages 17--34, were studied in relation to tenderness of shoulder muscles for five groups, (A) character display operators, (B) fluorescent lamp assemblers, (C) photographic film rolling workers, (D) teachers and nurses of handicapped children, and (E) office workers. No significant differences were found between the five groups in mean body height, body weight, and skinfold thickness, but mean knee extension force of groups A and C and mean back muscle strength of groups A, B, and C was significantly lower than that of group E. Workers of groups C and D with a low tenderness threshold of m. trapezius of 0.6 kg/cm2 or less had stiff shoulders more frequently and lower force levels of knee extension, back muscle, and upper arm abduction than those without tenderness. No similar tendency was found for groups B and E. Further, among workers with objective signs of occupational cervicobrachial disorder, there were few whose knee extension force or jump-step scores were above the averages of normal office workers. Shoulder muscles of such operators were revealed to be continuously contracted during operations. The possible effects of chronic fatigue due to repetitive operations on developing localized tenderness and occupational hazards are discussed.


Gonadal effects of pinealectomy and immunization against N-acetylindolealkylamines in the hamster.

In order to determine whether circulating melatonin (MEL) is necessary for the gonadal regression seen in hamsters exposed to a short photoperiod, animals were immunized with N-acetylserotonin (NAS) conjugated to protein. Antibodies formed against this conjugate bind MEL and NAS equally. When exposed to a short photoperiod (L:D, 1:23), a dramatic regression was seen in gonadal weight with no effect on body, Harderian gland or adrenal weight. Plasma testosterone levels also dropped. Immunization against NAS did not modify these effects, suggesting that circulating MEL does not mediate the antigonadal effect of the short photoperiod.


Differential localization of pituitary-adrenal activation and temperature changes following intrahypothalamic microinjection of morphine in rats.

Microinjections of morphine (MOR) into the basal mid-hypothalamus of rats elevate corticosteroid production of adrenal glands in vitro and plasma corticosterone (B) levels. Injections in or close to the rostral part of the arcuate nucleus were most effective in producing pituitary-adrenal activation, without affecting body temperature. Injections of MOR in the anterior hypothalamic area caused hyperthermia or hypothermia, depending on the dose and the site of injection, with little or no effect on piutitary-adrenal activity. The results indicate that piutitary-adrenal activation by MOR is mediated by structures in or close to the rostral part of the arcuate nucleus and that these structures can be distinguished from structures where MOR elicits temperature changes.


Biogenic amine control of growth hormone secretion in the fetal and neonatal rat.

The development of the hypothalamic-pituitary axis for growth hormone (GH) secretion has been studied in the rat fetus and in the neonate 4, 24, 48 and 72 h after birth. Injections of the serotonin blocker cyproheptadine (Cypro) and a catecholamine, dopamine (DA), each led to reductions in the level of serum GH in 21 to 22 day fetuses and in neonates up to 3 days after birth. The O-methylated derivative of dopamine, dimethoxyphenylethylamine (DMPEA), did not alter serum GH levels from those seen in saline-treated control animals. These results indicate that biogenic amines exert control over GH secretion in the fetus, close to term, and in early neonatal period. They suggest that this control is similar to that seen in the adult rat and in man and that such control may operate through serotonin receptors.


Biochemical effects of treatment with oral contraceptive steroids on the dopaminergic system of the rat.

The effects of acute and chronic administration of a combination of lynestrenol-mestrenol, a widely employed contraceptive medication, on the dopaminergic system of the rat forebrain and striatum were investigated to better understand the biochemical basis of the neurological side-effects of steroid contraceptive drugs (SCDs). Both acute and chronic treatment increased the disappearance rate of striatal dopamine (DA) after synthesis blockade with alpha-methyl-p-tyrosine (alpha-MpT). Moreover, the conversion of 3H-tyrosine (3H-T) into 3H-DA was increased in the forebrain and striatum after chronic administration of this steroid combination. In the same animals, the utilization of tyrosine (T) is increased.


Ophthalmoplegic migraine and periodic migrainous neuralgia, migraine variants with ocular manifestations.

The spectrum of migraine has been outlined with particular attention to two entities: Ophthalmoplegic Migraine and Periodic Migrainous Neuralgia. Although quite different in many respects from classical migraine, the relationship of a periodic localized vascular phenomenon giving rise to headache and transient neurologic signs, classify PMN and OPGM as migraine variants. Supportive of this concept, the literature has been reviewed in both entities, and some observations are made on the validity of earlier reports. It is the author's opinion that Raeder's syndrome should be reserved for patients with a lesion localizing in the paratrigeminal area. This does not exclude migraine as an etiologic agent but also recognizes tumors, infections and fractures as being more common.


[Fatal traffic accidents in the South Moravian Region during 1964-1974 and their social consequences].

A statistical evaluation of 2,327 persons killed during or as a result of road accidents and post-mortem examined in the years 1964-1974 brought to light the fact that the actual number of those deceased was considerably higher than that quoted by official statistics. In this particular group there were 81 cases of people whose lives might have been saved provided they had been given immediate medical and technical aid. An examination of the social consequences of the above cases made it clear that approximately every 100 cases of adults killed in their productive age (16-60 years) were associated with 77 unilaterally orphaned children, or else that for every 100 persons killed that particular period of life there were about 5 completely orphaned children .--Any effort at eliminating the all too ofter unnecessary deaths of persons involved in road accidents then makes it absolutely imperative to establish an appropriate system enabling toe recruitment of immediate medical and technical aid.


[Drugs and alcohol in 105 fatally injured participants of traffic accidents].

A total of 105 fatally injured participants of traffic accidents were examined for drugs and alcohol. Drugs were found in 12.38% subjects (12.5% drivers, 25% cyclists, 13.95% pedestrians and 9.09% fellow travellers). Drugs in combination with alcohol were found in 5.72% subjects, alcohol alone was detected in 21%. Out of 100 blood samples taken from living persons and sent for alcohol examination, drugs were found in 5 subjects. In 4 of them the alcohol level in the blood ranged from 0.67% to 1.64%.


[Results of blood group evaluations in terms of expert opinion in disputes over paternity].

The author evaluates the results of control blood group estimations in the sense of supreme expertise in paternity cases as performed during 7966 through 1974. As ensues from the analysis, the percentage of unconfirmed eliminating conclusions remains to be high, i. e. 5,5%. Different findings as occurring in various group systems have been encountered in 284 cases. Therefore revision of eliminating couclusions cannot be abandoned.


[Oxygen absorption of a biodynamic system in a transitional regimen. I. Determination of operational parameters].

In this first of three parts, operational parameters (power consumption with and without aeration, aeration number, oxygen volumetric transfer coefficient and hold up) of the system used are presented, together with graphs and tables to show the relation between these parameters and controlable operating variables. Later the values here presented will be correlated with KLa determined by SOM, the kinetics of oxygen transfer in yeast cultures.


[Aminoaciduria screening in newborn infants using, comparatively, chromatographic and colorimetric methods].

The authors showed that the colorimetric methods used to effect aminoacidopathies screening are inadequate and unspecific. The thin layer chromatography was chosen to effect such screening and the authors showed the incidence in newborns of some aminoacid metabolism abnormalities.


[Influence of lactose rate on calcium fixation in bones. Study in rats].

This investigation was performed to study the effect of lactose on the fixation of calcium in bones of rats. Lactose 3% and 10% concentration was used and the action was compared to that obtained by 67 U.I. of vitamin D in 100 g diet. The data obtained indicated very definitely that the presence of lactose in the diet favorably influences the fixation of Ca in bone, when the amount is 10%; at 3% concentration lactose don't seem influence Ca fixation in bone.


Effect of postoperative hypoparathyroidism on bone density.

The mean radiographic vertebral density of permanently hypoparathyroid patients was elevated above the normal-for-age, while the vertebral density of transiently hypoparathyroid patients was normal. Of the patients who received desiccated thyroid, both the transient and permanent hypoparathyroid patients had significantly higher-than-normal vertebral densities (P less than 0.01 and P less than 0.02, respectively). The duration of thyroid treatment corresponded with the degree of hypermineralized vertebral density in the patients with permanent hypoparathyroidism and permanent hypothyroidism (r = .728, P less than 0.01). However, in the transient hypoparathyroid patients, no significant relationship was found between the duration of thyroid treatment and vertebral density. Visual assessment of spinal radiographs for incidence of vertebral compressions revealed no significant differences between hypoparathyroid patients and the controls. In the patients with transient and permanent hypoparathyroidism who received calcium and vitamin D, the initially depressed blood calcium levels were within normal limits at the follow-up observation, but the untreated permanent hypoparathyroid patients were still depressed.


The Lx bodies of an eosinophilic granuloma in vivo and in vitro.

The ultrastructure of an eosinophilic granuloma is described. The typical tumor cell in vivo is the generally round histiocyte containing Langerhans cell type granules (Lx bodies), lamellar bodies, cytoplasmic clefts, and a markedly indented nucleus. In vivo, the Lx body was often continuous with the cell membrane, contained a typical periodic or nonperiodic median density, and had dilatations. Some dilatations were coated and similar to membrane-coated vesicles. The longest Lx body measured 4000 nm. After 18 days in culture, the ultrastructure of the histiocytes was similar to those in vivo. However, the Lx body in vitro had no association with the cell membrane, had no membrane coating, the median density was usually nonperiodic, and the longest body measured 7000 nm. Lx bodies in vivo were occasionally associated with vesicles containing membrane-enclosed particles (70--80 nm in diameter) without dense cores, whereas the median density of some Lx bodies in vitro were associated with membrane-enclosed particles (42--85 nm in diameter) with dense cores. Descriptions of the Lx body, its transformations in vitro, and its relation to lamellar bodies, membrane coated vesicles, and virus-like particles are the principal subjects of this report.


The effect of angiotensin II on electrolyte excretion by the renal tubules.

In vivo studies were done on mongrel dogs to determine the effect of angiotensin II on renal electrolyte excretion. Angiotensin II was infused directly into the left renal artery at a rate of 1 ng/kg/min. Angiotensin produced consistent reductions in the excretion of Na+, K+, and Cl- in the left kidney. These reductions could not be attributed to decreases in GFR or RPF. Electrolyte excretion by the right kidney was constant. These data are consistent with the hypothesis that angiotensin II may function as an intrarenal, antinatriuretic hormone.


Distribution of trace elements in the Houston environment: relationship to mortality from arteriosclerotic heart disease.

The relationship of trace elements to arteriosclerotic heart disease (AHD) was assessed. Samples of water supplies in the Houston area were analyzed periodically for cadmium, lithium, iron and zinc. Mortality data for each of the sampling areas, delineated according to boundary of water service, were used to compute average annual age-adjusted death rates for white males aged 35 to 64 during the years 1969 to 1971. Linear regression analyses were performed on the chemical constituents for the age-adjusted death rates due to AHD. Positive correlation coefficients for lithium and zinc were found to be statistically significant at the 0.05 probability level.


Renal autotransplantation: current perspectives.

Autotransplantation, with or without an extracorporeal renal operation, has been done 39 times in 37 patients. Indications for the procedure included severe ureteral injury in 4 patients, failed supravesical diversion in 2, renal carcinoma in a solitary kidney in 1, renovascular hypertension in 1 and donor arterial reconstruction before renal transplantation in 29. Success was obtained in all but 2 procedures, both of which involved previously operated kidneys with severe inflammation and adhesions involving the renal pelvis and pedicle. Based on our experience and a review of currently available literature we believe that renal autotransplantation and extracorporeal reconstruction can provide the best solution for patients with severe renovascular and ureteral disease not correctable by conventional operative techniques. The technique can be of particular value in removing centrally located tumors in solitary kidneys and in preparing donor kidneys with abnormal arteries for renal transplantation. The role of autotransplantation in the management of advanced renal trauma and calculus disease is less clear. A long-term comparison of patients treated by extracorporeal nephrolithotomy versus conventional lithotomy techniques will be necessary before a conclusion is reached in these disease categories.


Hormones in renal cancer.

Plasma renin, erythropoietin and chorionic gonadotropin levels were evaluated in 57 patients with renal adenocarcinoma. Renin elevation, found in 37 per cent, was unrelated to blood pressure levels but was associated with high grade, high stage lesions of mixed histologic cell type and predicted a poor prognosis. Erythropoietin was raised in 63 per cent of patients and was more sensitive than renin in indicating the presence of renal adenocarcinoma. However, it was less specific and did not correlate directly with tumor grade, stage, histologic type, prognosis or hematocrit and hemoglobin levels. None of the patients had elevated chorionic gonadotropin levels. Therefore, we believe that renin and erythropoietin determinations may be of value as biochemical tumor markers in renal adenocarcinoma.


Results of non-operative management of blunt renal trauma.

A study of 84 patients with blunt renal trauma has revealed that expectant, non-operative management of the clinically stable patient with either minor or more severe injuries (excluding vascular pedicle trauma) gives satisfactory results and entails few subsequent complications. The nephrectomy rate with expectant management is markedly lower than that reported after an immediate operation. The salvage of functioning renal tissue appears to be commensurate with angiographic delineation of devascularized tissue and would seem to be comparable to that of patients afforded immediate surgical intervention, without the threat of loss of the renal unit that appears to be entailed by early operation.


Elevated urinary levels of 5-hydroxyindole acetic acid and its relationship among levels of plasma follicle stimulating hormone, testosterone and testicular pathology in patients with severe oligospermia and/or azoospermia.

Plasma follicle stimulating hormone, testosterone and urine 5-hydroxyindole acetic acid levels were measured in 300 patients seen at an andrology clinic. Testicular biopsies were obtained from many of the severely oligospermic or azoospermic patients. Plasma follicle stimulating hormone concentrations were related inversely to sperm cell concentration, while plasma testosterone concentrations were depressed as the sperm count decreased to 5 times 106 per ml. The urine levels of 5-hydroxyindole acetic acid followed the same pattern as follicle stimulating hormone and were elevated in the group of individuals with sperm counts less than 10 times 106 per ml. Elevations in 5-hydroxyindole acetic acid often were associated with abnormalities in the testicular biopsy. Only 30 per cent of the patients who had elevated 5-hydroxyindole acetic acid also had elevated follicle stimulating hormone or depressed testosterone levels. The factors responsible for the elevation in 5-hydroxyindole acetic acid levels as the sperm count declines remain unclear.


Motion picture: transpubic total prostatectomy.

The transpubic approach for total prostatectomy is ideal in cases involving small glands that have been resected and reported as stage A tumors. The approach also is ideal for stage B1 and B2 tumors. It allows great ease in the osmosis of the bladder to the urethra and dissection of the lymph nodes in the obturator and iliac areas.


The continued evaluation of the effects of chemotherapy in patients with advanced carcinoma of the prostate.

The response and duration of survival were evaluated for patients with stage D relapsing prostatic cancer who were randomized to cyclophosphamide (Cytoxan),5-fluorouracil (5-FU) or standard therapy, or to subsequent chemotherapies. The chemotherapies on initial randomization were superior to the standard therapy in the number of responders and duration of response. Survival was longer for responders (stable or partial regression) on chemotherapy by comparison to responders (stable only) on standard therapy. The survival for patients receiving initial and crossover chemotherapy was significantly improved for patients who responded to therapy. Chemotherapy of advanced relapsing stage D prostatic cancer is more beneficially treated by specific chemotherapy as shown in this randomized study.


Thoughts on the prevention of urologic liability claims.

We have approached the problems of increasing urological liability claims with a superficial study of their causes and some suggested solutions. We believe that this approach is important because it is one that the urological community can take immediately rather than waiting for changes in state and federal laws that may be of benefit in decreasing the impact of these suits. It seems to be the common disease and the simple operation that lead to the lodging of a claim.


Benzydamine: a new weapon in the treatment of interstitial cystitis.

Benzydamine hydrochloride was synthesized in 1966 and developed in Italy. It belongs to a chemical class that has not been used previously in the treatment of inflammatory conditions. Benzydamine is not related to steroids or other anti-inflammatory drugs, it is given by mouth and its toxicity is low. A pilot trial was done in 25 cases of interstitial cystitis and virtually complete relief of pain was noted in 18 cases.


Correlation of ureteral orifice position with renal morphology.

Double ureters and kidneys have provided models for the comparison of radiographic appearances and the microstructure of each renal segment, as well as the correlation with the position of the corresponding ureteral orifice. An orifice located within the limits of the normal vesical trigone portends normal renal radiography and morphology. Orifices outside the normal limits of the trigone signify accompanying renal malformations in the corresponding kidneys, such as hypoplasia or aplasia of nephrons that are often difficult to determine histologically but that give rise to thin kidneys and clubbed calices, dysplasia of nephrons and abnormal interstitial tissue and blood vessels, all of which are detected more readily on microscopic examination. The more abnormal the orifice is in location and characteristics the more abnormal are the ureteral and renal segments. The correlation also applies to upper tracts when they are associated with lower tract anomalies, such as congenital urethral valves, neuropathic bladders of myelomeningocele patients and paraureteral diverticula.


Complications of single and multistage operations for hypospadias: a comparative review.

From 1970 through 1975, 198 children with hypospadias were operated upon at our clinic. Three basic types of primary urethroplasty were used: 1) a modified 2-stage Cecil urethroplasty after separate straightening, 2) a modified 1-stage Denis Browne procedure after prior correction of chordee and 3) a 1-stage combined repair of hypospadias and chordee. A comparative review of early complications is presented.


Central pressor actions of angiotensin II.

Involvement of the area postrema in experimental hypertension has been investigated. Ablation of the rear apex of the fourth brain ventricle (=the region of the area postrema) elevated blood pressure, heart rate and plasma angiotensin II level. The same characteristic changes were seen in the two kidney Goldblatt rat model of hypertension. A possible involvement of the area postrema in this model of hypertension is discussed. Intraventricular perfusion of angiotensin II elevated blood pressure without a significant change in heart rates. This pressor response appeared to be dependent on release of antidiuretic hormone. The results are discussed in relation to the intrinsic brain angiotensinogenase system.


Iron absorption and loss in psoriasis.

59Fe absorption has been studied in psoriatics to elucidate the iron deficiency state. To determine the rate of iron loss, elimination of injected 59Fe was measured. In psoriasis mean iron absorption did not differ from the mean in the normal group, but a pathologically low absorption was found in 8 cases. Iron loss was significantly higher in psoriatics than in normal men, while it did not differ significantly from iron loss in  women with regular menses.


Indocyanine green plasma clearance in normal human males and females.

The plasma clearance of indocyanine green (Cardio-Green, 0.5 mg/kg body weight) was studied in a total of 352 plasma samples from 7 male and 8 female healthy volunteers, and total bilirubinaemia in 6 males and 6 females. Statistical analysis (linear regression, SAAM programmes by BERMAN and WEISS [2],t-test. F-test and rank correlation) disclosed a significantly higher plasma disappearance rate of indocyanine green and significantly lower total bilirubinaemia in females than in males with a statistically almost significant negative correlation of both phenomena. A better excretion of indocyanine green from liver to bile in males though statistically significant could be an artefact caused e.g. by a not quite significant abnormally of the calibration straight line of the dye.


DNA synthesis in cells of human tuberculous lymph nodes.

DNA metabolism of cells of tuberculous lymph nodes was studied autoradiographically with 3H-thymidine injected directly into one of the afferent lymph vessels. The undifferentiated mononuclear cells showed the most intensive DNA synthesis, but a large number of epitheloid cells had also become labelled. The nuclei of the giant Langhans cells took no label.


Basal and insulin-stimulated glucose metabolism of isolated human fat cells.

Glucose-U-14C-activity added to the incubation medium of isolated human fat cells was studied for its conversion to CO2 and its incorporation into fat cell triglyceride. In view of the wide scatter of the figures found under basal conditions as well as in the presence of 100 muU/ml of insulin, the correlations of fat cell glucose metabolism to ponderal index, total body fat mass weight, mean fat cell diameter, fat cell TG-content and age were analysed. The activity of glucose metabolism in obese individuals was found to be inversely related to the degree of obesity under basal conditions as well as under the effect of insulin. According to partial regression analysis, of all these parameters it was the ponderal index which showed the most significant inverse correlation to the activity of fat cell glucose metabolism. No appreciable relationship was found between the production of CO2 from glucose and age. Incorporation of 14C-activity into fat cell triglyceride showed a slight age-related increase under basal conditions as well as on insulin stimulation. It is concluded that at the cellular level it is the triglyceride saturation of fat cells which constitutes the endogenous regulatory factor responsible for the impaired biological action exerted by insulin on the enlarged fat cells in obesity.


[Calibration of gel-chromatographic columns for examination of dextrans for clinical use].

A procedure is described which allows to obtain integral distribution in molecular weights for oligodextran preparations of clinical use from the elution profiles obtained by gel-filtration. The calibration procedure requires the use of commercially available dextran fractions with known distribution in molecular weight (the M.W. distribution of the standards may be checked through absolute determination of Mn and Mw). For given column dimensions and elution conditions, the outlined procedure yields an accurate plot of log Mw vs k (partition coefficient).


[Automation in analysis. VII. Automatic mineralization and determination of organic phosphorus].

An automatic manifold for the organic phosphorus mineralization is described. The device at issue does consist in an electrically heated aluminium blok, in which 80 holes are drilled, in order to hold 80 hydrolysis vials. The heating is automatically controlled by an independent unity. The ortophosphate determination is performed photometrically with the previously described automatic apparatus.


[Selection and acceptability of food].

In this paper the following factors which in one way or the other may have influence on the selection and acceptability of foods are treated: 1. Fisiological and psycological aspects; a) genetic factors, b) neurophysiological factors, c) emotional factors, d) perceptive factors. 2. Physical and ecological aspects. 3. Social and cultural aspects, a) habits and traditions, b) religious believes, c) tabues, d) nutrition faddism, e) prejudice, aversions and perversions, f) social value of foods, g) industrialized foods. 4. Economic aspects. 5. Educational aspects.


[Isolation of preparative amounts of polyribosomes from normal rabbit and guinea pig spleen].

Preparative amounts of polyribosomes were isolated from normal rabbit and guinea pig spleen; up to 40 optical units of the polyribosome preparation could be obtained by centrifugation in a Spinco L-2B centrifuge with SW-27 rotor. The amount of polyribosomes isolated from spleens of immune animals was 2-3 higher than that isolated from normal animal spleens. Concentration of polyribosomal preparations by lyophylization and the storage of dried preparations do not alter the sedimentation properties of the polyribosomes. The distribution pattern of normal rabbit spleen polyribosomes in a linear sucrose gradient and the sedimentation constants of the polyribosome peaks are in good agreement with data reported by some other authors for plasmocytome polyribosomes. Using electrophoresis in agarose-polyacrylamide gel the radioactive proteins synthesized in the cell culture of normal rabbit spleen it was shown that in normal spleen the average amount of globulins makes up to 35% of total protein synthesis, as reported by some authors.


[Application of phase partition method for the fractionation of hydrophobic membrane proteins].

Phase partition method in a two-phase polyethylene glycol-dextrane system has been applied to fractionation in Triton X-100 of hydrophobic membrane proteins from Micrococcus lysodeikticus. This method allowed to separate the cytochrome b556 from other cytochromes. Spectral and gel electrophoretic patterns of isolated cytochrome are given.


[Proteins of bacterial membranes. Purification of NADH-dehydrogenase by electrofocusing].

A highly purified preparation of NADH dehydrogenase was isolated from bacteria M. lysodeikticus membranes. The purification procedure involved extraction of the enzyme complex from isolated membranes by EDTA, solubilization of the complex by non-ionogenic detergent (1% Triton X-100), chromatography on DEAE-cellulose and electrofocussing in the pH gradient 4-6. The isoelectric point of the preparation is at 4.5; its main component is a protein with m.w. of about 76.000.


[Control of RNA biosynthesis in rat liver. Some features of RNA biosynthesis during prolonged protein synthesis inhibition].

A drastic inhibition of protein biosynthesis in rat liver in vivo by cycloheximide (CHI) (0.3 mg/100 g of body weight) first caused an increase of RNA synthesis (after 1 hour), which was then followed by its decrease. Partial gradual restoration of the protein synthesis level was shown to be accompanied by a repeated increase of RNA synthesis (12 hs) and its normalisation after 24 hs. The first maximum of RNA synthesis increase in the isolated nuclei system was AU-type RNA synthesis (sensitive to alpha-amanitine), the second one was due to GC-type RNA synthesis (resistant to this toxin). Purified chromatine template activity in the system with E. coli RNA polymerase (by 14%) an hour after CHI treatment, but 3 hrs later was decreased and subsequently restored (12 hrs after CHI injection). The changes of RNA biosynthesis induced by prolonged protein synthesis inhibition suggest the existence of continuous RNA synthesis control in nuclei. This control is realized by translation system using the feed back principle.


[Steady-state kinetics of electron transfer through the cytochrome chain of uncoupled submitochondrial particles. General kinetic analysis].

Steady-state kinetics of electron transfer through the cytochrome chain of uncoupled ultrasonic submitochondrial particles at different pH values were studied. The rate constants calculated according to Pring's equation (k1=V/Prpoxt i+1) were found to increase linearly with the increase in the rate of electron transfer. Linearity was observed, however, only at relatively low rates of electron transfer. Several kinetic models were developed and analysed to fit the experimental data on the basis of the suggested activation of respiratory chains induced by their functioning. The best agreement with the experimental data was obtained with the model implying that the rate of activation of the electron carriers is directly proportional to the overall rate of electron transfer and the portion of non-activated respiratory chains in the system. It followed therefrom that electron transfer through already activated chains induced activation of adjacent non-activated chains. This model made it possiple to determine the rate constants for non-activated (ki) and activated (k) carrier states and the life-times of activated carriers (tau).


[Effect of 2,4-diamino-5-chlorphenyl-6-ethylpyrimidine on the oncorporation of P32-phosphate into adenylic nucleotides of rat embryo and placenta].

Teratogenic doses of antimalaria preparation, 2,4-diamino-5-p-chlorophenyl-6-ethylpyrimidine (chloridine), known in biochemistry as a specific inhibitor of dihydrofolate reductase, result in the decrease of 32P-phosphate incorporation into ATP and ADP, coupled with the inhibitions of DNA synthesis, in rat embryo and placenta on 13th day of development, while the incorporation of 14C-formiate into free nucleotides of acid soluble embryo and placenta fractions (at the same intervals after teratogen injections), is the same as in the control. These data show that the primary blocking of folate cycle and DNA biosynthesis in 13 days old embryos with induced anomalies of development is some way coupled with disturbances of ATP metabolism.


[Localization of the Meler's reaction with ethanol catalase trap in the chain of photosynthetic electron transport].

The common view of photosystem I as the action site of catalase and ethanol at oxygen uptake in chloroplasts  are based on indirect data on this reaction. That is why the question on Mehler reaction localization in electron transport chain with ethanolcatalase trap has been investigated anew. It has been demonstrated that oxygen uptake with catalase and ethanol does not decrease in presence of dibromothymoquinone (2,5-dibromo-3-methyl-6 isopropyl-p-benzoquinone--DBTQ) which blocks electron transfer to photosystem I at plastoquinones level. The summation of oxygen uptake activities is observed on the combined action of catalase and ethanol with any of the Mehler reagents functioning in photosystem I (methylviologen,FMN, epinephrine, ferredoxin). Catalase and ethanol in contrast to methylviologen have no effect on photooxidation rate of reduced dichlorphenolindophenol in photosystem I. The quatum yield of oxygen uptake with catalase and ethanol versus wave length of actinic light shows a distinct maximum in the photosystem II absorption area and a "red drop" in the longware area. The obtained data show that the Mehler reaction with catalase and ethanol takes place in photosystem II only.


[Lipid-mobilizing activity of a synthetic peptide identical to 33-44 fragment of human growth hormone].

The lipid-mobilizing activity of a synthetic peptide, NH2-Phe-Glu-Glu-Ala-Tyr-Ile-Pro-Lys-Glu-Gln-Lys-Tyr-Ser-Phe-COOH, corresponding to the 31-44 amino-acid sequence of human growth hormone, was studied. The peptide stimulated lypolysis upon administration to fasted rats and during incubation with isolated epidiymal adiposed tissue of rat and perirenal adiposed tissue of rabbit. The lipid-mobilizing effect of the peptide,unlike the corresponding effect of the native growth hormone, developed fast and was markedly pronounced 15-30 min after the incubation was started. Direct dependence between the peptide dose logarithm and the effect studied was observed at concentrations of 0.01-10microng/ml during incubation with rat adipose tissue and at 0.001-0.1 microng/ml during incubation with rabbit tissue.


[Acetylcholinesterase of cobra venom. Determination of concentration of active sites].

O-Nitrophenyl dimethylcarbamate and organophosphorus inhibitors O-n-propyl-p-nitrophenyl methylphosphonate, O-n-butyl-p-nitrophenyl methylphosphonate, O,O-diethyl-p-nitrophenyl phosphate, O-n-butyl-S-(beta-ethylmercaptoethyl) methylthiophosphonate, methysulphate of O,O-diethyl-S-(beta-phenyldimethylammoniumethly) thiophosphate were used in the titration of acetylcholinesterase active site concentratration in Naja naja oxiana venom. No side reactions with the acetylcholinesterase molecule as well as with other components of the venom were observed. In titration the effective concentrations of organophosphorus inhibitors with asymmetric phosphorus were 50% of their analytical concentrations, since cobra venom cholinesterase showed practically absolute stereoselectivity against the compounds.


[Characteristics of the activity of "satellite" enzymes of gluconeogenesis in the oocytes and embryos of loach].

The activity of "satellite" enzymes related to gluconeogenesis has been measured in the oocytes and embryos at the early stages of loach (Misgurnus fossilis L.) embryogenesis. The activity of pyruvate dehydrogenase increase during oocyte maturation by 30%, remains constant at the cleavage and blastula stages and decreased on the onset of gastrulation. In the both oocytes and embryos pyruvate dehydrogenase has been found only in the active form. The activity of citrate synthase, malate dehydrogenase and pyruvate carboxylase remained constant during oocyte maturation and et all early stage of embrional development. Citrate lyase and "malic"-enzyme were not found, Oocyte maturation is followed by a considerable increase in the malate and oxalacetate content, the level of pyruvate and acetyl-CoA being found invariable.


[Molecular hybridization of native and modified subunits of lactate dehydrogenase isoenzymes and aldolase A in rats].

Experimental conditions for the molecular hybridization in vitro between iodine and native subunits of isoenzymes 1 and 5 of lactate dehydrogenase (LDH) are described. It is also shown that the covalently fixed on the polyacrylamide beads rat J125 labelled LDH-5 and J125 labelled aldolase A, under conditions of complete dissociation of the quaternary structure of these enzymes, only one of the four subunits remain bound with the beads. Subunit of LDH-5, which is covalently bound with the polyacrylamide beads, is capable to hybridize (reassociated) with 3 native subunits. In addition, the immobilized LDH-5 subunits and aldolase A are capable to hybridize with J125 labelled subunits of these enzymes. Thus, when thyrosine, lysine and N-terminal amino acids are modified, subunits of LDH-5 and aldolase A retain their capacity to restore their quaternary structures.


[Beta-cyanoalanine synthase: Its purification and basic physico-chemical properties].

A method has been developed for the purification of beta-cyano-L-alanine synthase from etiolated 10-day-old seedlings of blue lupine. High purity preparations of the enzyme were obtained with specific activity exceeding 4000-fold that of the seedling homogenate. Preparations were homogeneous on electrophoresis in polyacrylamide gel. The yield of total activity after purification was approximately 20%. Glutamic acid is the enzyme's only N-terminal amino acid; the molecular weight of the enzyme (both native and treated with 6 M urea) is 52000. The synthase containes one mole of pyridoxal-P per mole of protein; its isoelectric point is situated at pH 4,8. The enzyme's absorption spectrum has a maximum at 410 nm i.e., in the characteristic range of many pyridoxal-U-containing enzymes. Data on the amino acid composition of the enzyme are presented.


[Plasma kallikrein: new functions].

The literature data on some new functions of human plasma kallikrein have been discussed. The role of kallikrein as an enzymatic activator of Hageman factor in fluid-phase was emphasized, and the description of this effect, brought about by a feedback mechanism was given. These new findings stress the importance of plasma kallikrein in the initiation of kinin-forming, intrinsing clotting and fibrinolysis. The chemotactic activity of the kallikrein molecule for human neurophiles was considered. New data were given concerning Hageman factor as proteinase and its substrates in human plasma-coagulation factor XI (PTA), plasminogen proectivator and prekallikrein.


[The change of template activity of dog kidney chromtin by polyene antibiotics in vivo and in vitro].

Effect of amphotericin B and nistatin on template activity of nuclear membrane-bound (DNPm) and free (DNPo) dog kidney chromatin after intravenous injections of antibiotics and after the incubation of isolated kidney cell nuclei with the antibiotics is studied. It is found that injections of amphotericin B and nistatin resulted in the increase of DNPo template activity in RNA polymerase system, the stimulating effect of nistatin being higher than that of amphotericin B. Injections of nistatine stimulated also template activity of DNPm, while amphotericin B produced no effect on DNPm. When studing the effect of polyene antibiotics on template activity of DNPo and DNPm in vitro, it is found that the intensity of RNA synthesis after incubation of isolated nuclei with antibiotics is considerably increased, and stimulating effect of nistatin is higher than of amphotericin B. Both antibiotics produced no effect on template activity of DNP in vitro. Thus, comparative analysis of changes in template activity of dog kidney chromatin under the effect of polyene antibiotics in vivo and in vitro has revealed the similarity of these drugs and draws to the conclusion that nistatin and amphotericin B produce a direct effect on template activity of chromatin.