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The entire sequence of α2-CB2 from calf skin collagen, a cyanogen-bromide-derived peptide from the central portion of the α2 chain containing 30 amino-acid residues was established. The sequence of 22 N-terminal residues of α2-CB2 from human and rabbit skin collagen and of 26 residues of the corresponding peptide from pig skin collagen were also determined. Comparison of the sequences revealed six definite positions within the first 21 amino-acid residues of the peptide in which substitutions occurred, suggesting a portion of high sequence variability within the α2 chain.

In any radiotherapeutic treatment there is a maximum dose of radiation which may safely be given to the normal tissues at risk. The clinician is aware that any increase in dose above this level will increase the probability of causing late necrosis and other complications. In the skin of some patients waves of injury have been observed after irradiation. Each wave lasts longer than the preceding one, and late necrosis develops after high doses. The same phenomena have been observed in pig skin (1) and in rat skin (2). In order that a quantitative analysis may be made of the relationship between early and late irradiation damage, an examination of the different stages of reaction of the feet of rats has been made following various schemes of fractionated irradiation either with x rays or with fast neutrons. Technic The hind feet of male adult rats were irradiated with 250 kVP x rays or with fast neutrons from the cyclotron at Hammersmith Hospital (3, 4). Single doses, two and five fractions at daily interv...

Irradiation of pig skin was carried out with surface applicators containing radium (35 rads/hr.) and californium 252 (12–13 rads/hr.). Observations were made over a 100-day period and skin reactions scored. The dose required to produce a moist reaction which did not heal within fifty days was 8,400 rads for radium and 1,725 rads for californium; this yielded an RBE of 4.9. The results indicate very little recovery or repopulation during irradiation by californium 252.

Frequent reference is made in the literature to the presence of vitamin D precursors in human skin. In 1930 Hentschel and Schindel (1) demonstrated, by chemical and spectroscopic methods, the presence of a provitamin-like substance in human skin which they assumed to be ergosterol. The amount present was estimated as 0.42% of the isolated sterols. Windaus and Bock (2) in 1937 demonstrated the presence of vitamin D precursors in certain animal skins and were able to isolate 7-dehydrocholesterol (pro-vitamin D) from pig skin; they did not, however, examine human skin. More recently, Miller and Baumann (3) examined a single specimen of human skin from the mammary area and found that the isolated sterols contained 0.43% 7-dehydrocholesterol and 1.07% Liebermann-Buchardt “fast-acting “ non-provitamin compounds. This observation was not pursued further (Baumann (4)). In an extensive examination of human skin surface lipids, however, vitamin D precursors could not be detected (Festenstein and Morton (5); MacKenna, Wheatley, and Wormall (6)). More recently Boughton and Wheatley (7) were able to demonstrate only a trace (about 0.0008% of 7-dehydrocholesterol) in such lipids.

Thee copolymeric structure of pig skin dermatan sulfate was further studied with particular referene to residual glucuronic acid moieties present in the molecule after sequential treatment with testicular hyaluronidase and β-glucuronidase. Subsequent treatment with chondroitinase-AC lead to a further release of glucuronic acid in the form of disaccharides, tetrasaccharidies and higher oligosaccharides/glycopeptides. Since these products contained nonreducing teminal, unsaturated uronic acid residues, it was concluded that some of the residual glucuronic acid moieties were located in ultimate or penultimate reducing terminal chondroitin 4-sulfate repeating periods of fragments obtained after cleavage with testicular hyalyronidase. Additional, single chondroitin 4-sulfate repeating periods were present in the vicinity of the carbohydrate-protein linkage region or elsewhere in the chain. The former periods were regularly obseved 2-3 units apart from the linkage region whereas the latter periods occurred preferentially in sequences like…BBBBABABAAAA…(A and B are chondroitin 4-sulfate and dermatan sulfate repeating periods, respectively).

In the nuclear power and radioisotope handling facilities, one of the most important problems is a radioactive contamination on skin. Hand skin contamination occurs very often in the operation area and such surface contamination must be removed as soon as possible to protect an internal contamination.From 1967 to 1971, training courses for skin decontamination had been held with total 350 of trainee based on JAERI radiation protection manual at the Oarai Research Establishment. In the training courses, fresh pig skin samples used instead of human skin were contaminated with 137Cs, 131I, 144Ce and 239Pu aqueous solution, respectively. These samples were washed practically by trainee with the skin decontamination method recommended in the manual.Results obtained in the courses showed that such training itself is a significant work and this skin decontamination method is an excellent first aid.

The autoradiographic technique, using 5 μ paraffin sections in contact with 5 μ NTA emulsion for 10 hr. and similar sections of sputum for 3 days, was found to be more sensitive for detecting contamination with Pu239 than tests with a scintillation counter. Both human and pig skin were tested. The autoradiograms showed characteristic alpha tracks in the emulsion at sites of Pu deposition following its uptake either in solution or in particulate form. Autoradiography is recommended as a routine method to supplement information gained from chemical analyses and counting procedures.

Experiments on the skin of pigs showed a marked dose-rate dependence of the biological effect of cesium-137 or radium-226 gamma rays over the clinically useful range. The slope of a line relating duration of exposure to dose was 0.296 in a series of experiments. On the other hand, exposure to mixed neutron and gamma-ray 252Cf radiation resulted in effects which were much less dependent on dose rate. The relative biological effect varied markedly with dose rate from about 5 at acute exposures to over 7 at prolonged low-dose-rate exposures.

A fraction containing the least possible quantity of glucuronic acid was separated from skin itinsulfate of pig, and two disaccharides chondrosine and “dermosine” which is galactosamine-3-L-iduronide were isolated from its hydrolysate. The properties of those disaccharides are described.

This paper deals with skin contamination of plutonium, of which safe handling is a serious problem. Experiments were carried out by use of auto-radiographic analysis of plutonium contamination on pig skin.It was found that plutonium contaminated hair-tops, hair-shafts, hair-follicles, furrows and pores on the skin, and the hair contamination could not be disregarded in the decontaminating treatment. Exact analysis of skin contamination by plutonium is, however, in need of further investigation.

Purpose: The aim of this study is to present the results of evaluation of Plastic Surgery Clerkship by students using questionnaire, and to find out the ways to improve the evaluation method and content of clerkship. Methods: In 2002, the evaluation was conducted by Department of Plastic Surgery, College of Medicine, Inha University. The questionnaires were filled up by 28 junior students who completed the 2 weeks clerkship schedule. The questionnaires were consisted of 25 structured items with 5-grade scale each. Results: The students favored operation room training and emergency room duty where they could participated the procedures (suturing, cutting and etc.). They also favored the suturing exercise (300 stitches) using pig skin or sponge. The conferences (especially Journal Club) were least favored. The difficulty of the quiz was moderate. The most of the quiz items were included in the contents that the students gad learned during the clerkship. Conclusion: This result could be an basic data for improving the clerkship program. The students should be fully informed of the object of the evaluation be fore it is carried out. An organization which takes complete charge of the instruction evaluation should be established.

Collagen is an ubiquitous structural protein, which constitutes about 25-30% by weight of all proteins in the mammalian body. It functions as an important supporting element in vertebrate tissues. Using the method of cleaving the protein chains at the methionyl residues with cyanogen bromide (CNBr), many species of collagen from different sources have been isolated and characterized, e.g. rat skin [l ,2] , chick skin [3] , calf skin [4,5] and human skin collagen [6] . Pig skin collagen seems to be interesting from the point of view, that is, its applicability in the medical sector [7,11,12] , due to its poor or non-antigenic reactivity. We reported previously about the isolation and characterization of the large CB-peptides derived from both oiland cw2-chain of the pig skin collagen [8]. This report deals with the isolation, characterization and comparison of the N-terminal CB-peptides of soluble pig skin collagen with the corresponding peptides derived from rat skin, calf skin and human skin collagen.

This paper deals with the contaminabilily and the permeability of Pu with varying soiling lime and acidity of the soiling solution applied to pig skin. It was found that the contaminability of Pu was affected by the formation of colloidal substances in soiling solution, as in the case of Pm, Sb, Po and U, described previously. It was also found that 0.05% of the Pu penetrated through the pig skin with pH 1 soiling solution after 60 min.

Experiments were carried out to determine the surface and interior contaminations in layers of fresh pig skin that had been soiled with 35S, 125Sb, 147Pm, 204Tl, and 210Po solutions of various acidities for various periods of soiling time.It was proved that Tl+ is cationic, S(SO2-4) is anionic and Sb3+, Pm3+, Po4+ are radiocolloidal in their mode and character of skin contaminability. The last three showed distinctive skin contaminations in the acidity regions for radiocolloidal formation.It was found that interior contamination is almost negligible, regardless of contaminant species, acidity, or soiling time.

Selective periodate oxidation of unsubstituted l-iduronic acid residues in copolymeric dermatan sulphate chains was followed by reduction-hydrolysis or alkaline elimination. By this procedure the glucuronic acid-containing periods were isolated in oligosaccharide form; general formula: [Formula: see text] Further degradation of these oligosaccharides with chondroitinase-AC yielded three types of products: (a) sulphated trisaccharide containing an unsaturated uronosyl moiety in the non-reducing terminal and a C4 fragment in the reducing terminal, ΔUA-GalNAc-(-SO4)-R; (b) monosulphated, unsaturated disaccharide, ΔUA-GalNAc-SO4 when n is greater than or equal to 2; and (c) N-acetylgalactosamine with or without sulphate. Oligosaccharides containing a single glucuronic acid residue (n=1) comprised more than half of the glucuronic acid-containing oligosaccharides. The terminal N-acetylgalactosamine moiety of the shortest oligosaccharide was largely 4-sulphated, whereas higher oligosaccharides primarily contained 6-sulphated or unsulphated hexosamine moieties in the same position. Moreover, IdUA-SO4-containing oligosaccharides were encountered. These oligosaccharides were resistant to the action of chondroitinase-ABC.

The development of subcutaneous fibrosis after X irradiation in courses of 1, 6 or 30 fractions has been studied quantitatively in the domestic pig. The NSD formula fails to predict the correct variation in dose for changes in the number of fractions so as to produce comparable levels of connective tissue damage even over the clinically used range from 6f./18d. to 3Of./39d.; the error in the prediction may amount to an excess dose of circa 30 per cent. The slope the iso-effect curve between 6 and 30 fractions is 0·46, compared with the combined fractionation and time factors of 0·33 in the NSD formula. The degree of late fibrosis did not correlate with the severity of the early skin reaction. The results suggest that the NSD formula is not suitable for use when planning new treatment schedules in which the number of dose fractions is reduced.

Acid mucopolysaccharides from embryo skin have been isolated and identified. It was found that embryo skin contained only very small amounts of chondroitin sulfate B, in the presence of relatively large amounts of hyaluronic acid, while adult pig skin contains considerably more chondroitin sulfate B than hyaluronic acid. In addition, ambryo skin was found to contain a relatively large amount of chondroitin sulfate C.

Summary Reconstituted lyophilised pig-skin dressings have been used on skin graft donor sites. Their advantages are: They virtually eliminate all pain and discomfort from the donor sites. They allow earlier ambulation with comfort. By minimising the inflammatory reaction around the donor sites, pig-skin cover allows epithelialisation to proceed at an earlier date and the epithelium shows earlier maturation and organisation of the basal layers.

The skin of pigs has been used to study the effect of fractionated irradiation with fast neutrons of mean energy 6 MeV. Six, nine and 15 fractions have been used over a period of three weeks, and two fractions divided by short intervals of time up to 24 hours. The effects of fractionated treatments with X rays are also summarised. The RBE of the neutron beam rises steadily from 2·3 for a single dose to 3·6 for 15 fractions. Observations up to five years after treatment have failed to show any sign of increased late reactions after neutrons. There is less recovery during a fractionated course of treatment with fast neutrons than with X rays, the relative amount of recovery being 0·6. Very little recovery was observed during the first seven hours after treatment with neutrons. Reactions occurring after fractionated treatments with X rays show that the number of fractions is more important than the time over which the treatment is extended, up to 28 days, but that prolongation is nevertheless a sign...

A dermatan sulphate proteoglycan, representing approximately 30% of the dermatan sulphate in pig skin, has been isolated and purified. The preparation contained only trace amounts of other glycosaminoglycans and was completely free from collagen. It contained 58% of protein (w/w) and all of the polysaccharide chains were bound to the protein via alkali-labile linkages. The proteoglycan was polydisperse; the major portion had a weight-average molecular weight of 2.9·106, but the presence of non-covalent aggregates could not be excluded. The weight-average molecular weight of the constituent polysaccharide chains was 15 000.

1. The respiration of bacteria normally present in thin slices of skin taken from pig's trotters has been measured in Cruickshank micro-respirometers.2. These respirometers were originally designed to measure skin respiration in a medium including antibiotic to inhibit bacterial activity. The skin and medium was contained in a glass well. Using pig skin in a similar system without antibiotic, bacteria left the skin to grow independently in the medium. To overcome this difficulty polythene cups were made with an inner compartment for the tissue without medium and an outer compartment for water which provided a humid atmosphere.3. Using polythene cups without medium the skin respiration was neglible, bacterial respiration was measured in situ and correlation between oxygen uptake and bacterial counts was obtained. This correlation was valid within experiments only.4. Respiration of skin samples taken from adjacent areas of pig's trotter was similar, but there was large variation between samples from different trotters.5. Respiration due to bacteria increased rapidly for 6–9 hr., followed by a slower increase. This may be due to a limited food supply or to a state of equilibrium.

A COMBINATION of surgery and radiotherapy is frequently used in the treatment of malignant disease. By consu'ltation between surgeon and radiotherapist, and by careful planning, any necessary operation can sometimes be timed to take place at the optimal phase for healing in relation to the development of radiation effects (Ellis and Patterson, I968). More often, however, the surgeon is faced with the need to excise a tumour which has recurred following radiotherapy, or to treat the late damage resulting from irradiation. The problem then is to know how much tissue should be excised in order to clear the radiation-damaged area. The radiotherapist can indicate the exact limits of the fields of irradiation. It is much more difficult, however, to estimate how much scattered radiation has affected the tissues beyond this and how far the blood supply in these areas has been damaged. All surgeons are familiar with the problems of designing local flaps, and of getting grafts to" take "and wounds to heal near previously irradiated tissue. In view of the difficulties of studying this in man it would be useful to have an experimental system which would be as near to the clinical situation as possible. For reasons previously discussed (Patterson, I968), the pig is a suitable experimental animal. The opening of the Churchill Hospital Research Institute in April I97 o provided an environment in which surgeons, radiotherapists and radiobiologists could work together on these problems. The Institute has facilities for studying all aspects of malignant disease. This paper describes some of our preliminary results of the short-term radiation effects on pig skin. Assessment was by means of the skin flap preparation on the flank of the pig previously described (Patterson, I968 ). Here a rectangular flap of skin is raised in such a way that all blood supply is divided, except that coming in from a ventrally sited pedicle. The efficiency of this blood supply is then measured by the length of the flap that survives. Alterations in the blood supply as a result of radiation to a flap should thus be shown by alterations in the surviving length of the flap. In experiments on the pig for a different purpose some years ago it was found that an intra-vital dye (Disulphine blue), injected intravenously, was a fairly accurate predictor of the survival of skin flaps (Patterson and Milton, 1967). This technique was not directly applicable to the present experiments, but the dye was injected at varying times after radiation to see whether it would provide additional evidence of the state of the blood vessels in irradiated skin. Experimental Design. Large White pigs were paired for age and sex. The flank of one of each pair was shaved 24 hours before operation, the other pig being left unshaven. Under a general anaesthetic four flaps, I6 cm. long and 4 cm. wide, were marked out on the flank with a gap of 4 cm between each flap. The outlines were lightly scored with Indian ink as a permanent marker. Each flap was then given a single dose of x,863 fads or 2,I32 fads with 250 kVp X-rays (HVL I'3 mm. Cu.). These doses z This paper was presented at the joint meeting of theAssociation of Radiation Research and the Netherlands Radiobiological Society held in Oxford in April x97 x.

Fifteen fields on one pig were irradiated with 1, 2, 2, 3 and 5 fractions in 1, 5, 2, 3 and 5 days respectively. Skin reactions were recorded up to 80 or 100 days, so that the doses which produced equal reactions could be assessed. Three degrees of damage were analysed for early, medium and late reactions. As an example, the doses to produce one level of reaction over 30–85 days were respectively 2,050, 2,560–2,750, 2,750, 3,360 and 4,060 rads for the fractions listed above. The corresponding values of “DQ” = (Dn — D1)/(n —; 1) were high, 500–700 rads. The values of (Dn − D1)/(n − 1) became smaller with larger numbers of fractions. Two pigs were irradiated to investigate the “reciprocal vicinity” effect. It was found to be small for the field arrangements used, but the sensitivity of pig skin increased in the dorso-ventral direction and corrections were sometimes necessary. Two pigs were irradiated with pairs of equal doses separated by 0 to 24 hours. A recovery pattern was observed similar to that found ...

The effect of asiaticoside, a drug for which wound healing properties are claimed, has been investigated on pig skin in organ culture of young animals. The histological changes show that asiaticoside has an activating effect on the epidermis by activating the cells of the Malpighean layer and stimulating keratinisation. Also it probably has an activating effect on the dermis. Respiratory studies of skin in the presence of asiaticoside show that this compound, in spite of its ability to promote definite histological changes, has no effect on the respiratory rate. This would indicate thet either the respiratory changes are too small to be measurable or they do not exist. In either case the findings suggest that skin researchers should interpret metabolic studies involving total oxygen uptake of skin with considerable caution.

The Castroviejo Keratotome has been used in an attempt to determine the quantitative distribution of bacteria within various thicknesses of pig skin. Results of bacterial counts obtained from serial sections of pig skin indicated that even after vigorous washing, which would remove most of the “transient”surface bacteria, the majority of bacteria were found in the outer 0·3 mm, with decreasing numbers in progressively deeper sections. The results obtained from closely adjacent areas of pig skin from the same animal were comparable, but there were occasional high counts. This indicated that the distribution of bacteria along the skin surface was not constant. The possibility that these high counts were derived from areas immediately above a gland is discussed. The results of bacterial counts made on surface sections of human skin removed with the Keratotome are also presented.

Dr. Roger Berry was kind enough to send to me a copy of the article on Excess Late Subcutaneous Fibrosis after Irradiation of Pig Skin Consequent Upon the Application of the NSD Formula. I feel that the following comments are justified. (1) The value of 0·33 as the regression coefficient for the isoeffect line when log dose is plotted against log time has considerable basis in many previous publications. This is used as a basis which, suitably partitioned according to the NSD concept for the first time, made possible for the first time separation of the effects of fractionation and of time (Ellis, 1966; 1968; 1971).

HUMAN skin presents a high impedance to alternating current of low frequency1. The impedance is greatly reduced if the surface layers of the skin are abraded2. When the frequency of the applied a.c. is raised above 10 c/s, the impedance falls; the equivalent circuit is a polarization impedance in parallel with a resistance3. The impedance of rabbit or pig skin is less than that of human skin, and is also less dependent on frequency (Fig. 1).

ALTHOUGH the pig has well-developed structures in the skin which conform morphologically with apocrine sweat glands, the animal does not appear to sweat. Measurements made by Moritz and Henriques1 and Ingram2 showed that at temperatures below the critical temperature, cutaneous water-loss over the general body surface, but excluding the snout, is similar to that in man and other animals. At high environment temperatures, however, even when body temperature is elevated, water-loss from pig skin is only of the order of 30 g/m2 h and can be accounted for by the increased vapour pressure gradient consequent on the increase in skin temperature which occurs after vaso-dilatation. Confirmation of a low evaporative heat loss also derives from observation made on the new-born pig by Mount3, who estimated that the increased evaporative loss at high ambient temperatures could be accounted for by losses from the respiratory tract alone.

Dr. Frank Ellis has let us see his comments on our paper “Excess late subcutaneous fibrosis after irradiation of pig skin, consequent upon application of the NSD formula”, and we feel that the attention of uncommitted readers should be drawn to certain points: Comment (2) of Dr. Ellis' letter quotes two references which have no bearing on the point he makes—namely that we have not applied the correct dose for our work.

In a previous paper 1 I made a preliminary report on the predominance of subsurface growth on mediums made with hydrolyzed hair, hydrolyzed pig skin and cysteine hydrochloride. In this paper the types of subsurface growths noted, the variables incident to the correlation of subsurface growth with invasiveness and chronicity of pathogenic fungi for man, and the factors probably accountable for the results are discussed. Little is known regarding the basic factors accountable for the invasiveness and chronicity of micro-organisms. If anything was to be learned it was evident that if the culture in the test tube was to be studied and correlated, a medium made of tissues for which the organisms were selective was the point of departure. It is known that: 1. The type of growth might yield valuable information. 2. Organisms grown on mediums made of such ingredients as peptone and blood tend to dissociate. This is

The skin of pigs has been used to study the effect of fractionated irradiation with fast neutrons of mean energy 6 MeV. Six, nine and 15 fractions have been used over a period of three weeks, and two fractions divided by short intervals of time up to 24 hours. The effects of fractionated treatments with X rays are also summarised. The RBE of the neutron beam rises steadily from 2·3 for a single dose to 3·6 for 15 fractions. Observations up to five years after treatment have failed to show any sign of increased late reactions after neutrons. There is less recovery during a fractionated course of treatment with fast neutrons than with X rays, the relative amount of recovery being 0·6. Very little recovery was observed during the first seven hours after treatment with neutrons. Reactions occurring after fractionated treatments with X rays show that the number of fractions is more important than the time over which the treatment is extended, up to 28 days, but that prolongation is nevertheless a sign...