[Current trends in medical and surgical treatment of epilepsy].

The AA., after a critical review of the literature, discuss the actual problems related to the various forms of the epilepsie susceptible of an appropriate surgical treatment. The AA. consider that the modern S.E.E.G. techniques, such as the formed in the highly specialized center of Bancaud and Talairach, open new perspectives particularly for the cases resistant to medical treatment and without evidence of focalisation. The AA. discuss the criteria, justifying such limitations and auspicate the institution of a much limited number of such centers, also in Italy.


[Mutagenic action of platinum and palladium compounds on bacteria].

Platinum complex compounds are shown to cause mutations in S. typhimurium strains, TA-100 and TA-98 bearing plasmid pKM-101 but not in isogenic strains TA-1535 and TA-1538 lacking the plasmid. The mutagenic action depended on the ligand nature in the complex and did not depend on the extent of the central atom oxidation. No mutagenic activity of the palladium compounds tested was found.


[Use of mathematical recombination models for mapping Escherichia coli K-12 markers].

The possibility is discussed of mapping the E. coli K-12 markers on the basis of mathematical models of recombination previously developed by the authors. The analysis showed that it is advisable to use the symmetrical crossing-over model for mapping the genes close to the selective marker. The stochastic model of recombination gives good results also for genes located in the proximal part of the chromosome.


Combined ultrasound--radiographic detection of ureteral obstruction in renal transplants.

A case of renal transplantation is presented in which ultrasound was used to detect and control the puncture and aspiration of a renal abscess and a lymphocele. Subsequently, the combined sonographic-radiographic technique was used to diagnose and demonstrate the site of obstruction of the ureter. Ultrasound, in combination with fine-needle puncture when necessary, has many advantages in the management of renal transplantation.


Escherichia coli diarrhoea in pigs with or without the K88 receptor.

There was a high incidence of neonatal scours in 38 litters of pigs born at Compton in a four month period during 1978. The most important cause of the disease was an enteropathogenic Escherichia coli strain which possessed the K88 antigen. The Compton herd has been bred to produce pigs of three genotypes with respect to the presence or absence of the intestinal receptor for the K88 antigen. These are homozygous dominants (SS) and heterozygotes (Ss) susceptible to infection by virulent K88-positive E coli, and homozygous recessives (ss) resistant to the disease. The highest incidence of diarrhoea was in the susceptible progeny of resistant dams and susceptible sires. There was no K88 associated diarrhoea in resistant progeny or in susceptible progeny of susceptible dams.


A review of olfactory dysfunctions in man.

Although a large number of individuals experience olfactory disorders following accidents, disease states, medical interventions, aging, and exposure to environmental chemicals and pollutants, few medical practitioners have the expertise or staff to provide appropriate clinical evaluation, treatment, counseling, or referral for such patients. The present review examines studies associated with the diagnosis and treatment of olfactory disorders, as well as ones noting olfactory signs as diagnostic markers for brain tumors and other serious problems. A basic taxonomy of smell dysfunctions is presented, along with a review of etiologic factors, including local diseases and mechanical obstruction of the airways, viral infections, trauma, congenital anomalies, endocrine disorders, tumors, psychiatric disorders, aging, drugs, environmental and industrial pollutants, iatrogenic factors, and miscellaneous diseases. A discussion of current disability compensation guidelines in the United States and Britain is also presented.


The effect of a plasmid on growth and survival of E. coli.

We studied the growth characteristics of a pair of Escherichia coli strains, isogenic apart from the possession of a nonconjugative plasmid. There was no difference between the two strains when they were grown separately. In mixed culture, a second slow phase of growth that normally occurred following the end of rapid exponential growth, was absent from the plasmid-carrying strain. This resulted in a considerable decrease in the proportion of the cells that carried the plasmid after overnight incubation. The effect of different conditions of growth is reported. The plasmid-carrying strain survived extended incubation (150 days at 37 degrees C) as well as did the plasmid free strain separately. In a mixture, the proportion of plasmid-carrying cells declined rapidly, and none was detected after 100 days.


Activity of some enzymes during growth and sporulation of Clostridium botulinum type E.

The activities of alkaline and acid phosphatases, glucose dehydrogenase and NADH oxidase were assayed in cell-free extracts of sporogenic and asporogenic mutants of Clostridium botulinum. During growth of both mutants, the activities of alkaline and acid phosphatases were relatively constant, but during sporulation of the sporogenic mutant, the alkaline phosphatase activity rose to a maximum of 70 mumol/min x mg protein whereas the acid phosphatase decreased rapidly before it increased, indicating a possible role in sporogenesis. Glucose dehydrogenase activity was detected only in cell-free extracts of the sporogenic mutant and reached a maximum of 7 mumol/min x mg protein during the endospore maturation stage. The NADH oxidase activity was detected in both mutants. The NADH oxidase seems to stimulate glucose oxidation in both mutants during growth and the dehydrogenation processes of the butyric type of fermentation during spore formation in the sporogenic mutant. The findings suggest that increased glucose dehydrogenase activity in C. botulinum, as in Bacillus species, may serve as a spore event marker and that alkaline and acid phosphatases may play a regulatory role in anaerobic sporulation metabolism.


Colonization by Salmonella typhimurium and Shigella flexneri III of the gastrointestinal tract of mice treated with beta-2-thienylalanine and streptomycin.

Mice fed beta-2-thienylalanine (beta-2-T) by oesophageal tube were no more susceptible to gastrointestinal tract colonization by Salmonella typhimurium or Shigella flexneri III than control mice fed water. In both beta-2-T-fed and water-fed groups, the increasing dosage of S. typhimurium, in logarithmic increments to groups of mice, resulted in increasing numbers of these bacteria detectable on dilution plates from organ homogenates. Colonization by S. flexneri III only occurred at a dosage of 10(8) bacteria for both groups. Pretreatment with 50 mg streptomycin allowed 10(3) Salmonella or 10(4) Shigella to colonize both beta-2-T and water-fed groups. Coliforms, inhibited by beta-2-T under certain conditions in vitro, were found in equal numbers in both groups. No obvious differences were noted in either types of other bacteria detected or numbers recovered from the two groups. No gross behavioural changes were noted in mice fed beta-2-T and not challenged with pathogenic bacteria, and no pathological changes were noted in hepatic or splenic tissues. With increasing Salmonella dosage, collections of polymorphonuclear leucocytes, which were almost focal, and increased numbers of giant cells were noted in splenic red pulp areas, in both groups.


Cell cycle regulation in mammalian cells: hormones and commitment to DNA synthesis.

The growth regulation of cultured mouse fibroblasts and functional adrenal cells was studied. Variants of mutants from these cell lines were obtained. The effects of classical hormones (insulin, hydrocortisone and adrenocorticotropin) and of growth factors (EGF and PF) were analysed. These hormones stimulate or inhibit the entry of cells into S phase. However G1 cells become irreversibly committed to DNA synthesis 5 hours before entering S phase.


Relationship between basic proteins associated to DNA and replication during early development of Echinoderms.

A close relationship between histone synthesis and DNA replication has been suggested for many biological systems. The presence of histonic proteins has been demonstrated in practically all kinds of eukaryotic cells. During the clevage period of sea urchins it has been postulated that histones are not present in nuclei, and that only at blastula stage they do associate with DNA. Our results suggest that the failure to isolate histonic proteins from nuclei derived from cleavage cells might be caused by the presence in those cells of proteases activated by NaHSO3. This compound has being widely used to inhibit proteolytic action in other biological systems. By changing the method for chromatin isolation, we have been able to isolate basic proteins from nuclei of gametes, zygotes and 2-4 blastomeres. These proteins behave like calf thymus histones in urea-acetic acid polyacrylamide gels, and they do not show great differences from proteins isolated from nuclei of blastula, gastrula, prism, and pluteus. The electrophoretic patterns of basic proteins obtained from eggs and zygotes are practically identical, except for one protein moving like lysine-rich calf thymus histones. This protein appears in zygote nuclei at the beginning of the first replication wave.


[Some parameters of cellular immunity in renal transplantation after more than three years].

This paper evaluates the cellular immune system of 16 cadaver kidney transplant recipients more than three years after transplantation. The number and percent of active E rosette forming cells, of E rosette forming cells and of IgG and IgM bearing lymphocytes were determined; the blastogenic response of peripheral blood lymphocytes to PHA and PWM was studied in homologous and autologous serum. Significant alterations of the tests performed were found in patients who had undergone kidney transplant, suggesting a pathogenetic role of chronic immunosuppressive therapy but not excluding other possible factors.


Epidemiological survey of hepatitis B virus infections in various groups of population.

An epidemiological survey of hepatitis B virus (HBV) infection has been carried out from 1974 up to 1978 in four laboratories, with the aim of identifying high-risk groups in the population. Radioimmunoassay procedures were used in order to detect the hepatitis B surface antigen (HBsAg) and the corresponding antibody (anti-HBs) in serum samples from over 100,000 individuals of various geographical origin (mainly from Ligury or from other areas in Northern Italy). The groups of population under monitoring included: individuals without hepatic illness just after admittance into hospitals (these groups were found to be adequately representative of the corresponding open population), groups of children and boys from the open school population, individuals living in various communities (foundling hospital, children college, recruits, institutionalized old people, subnormal individuals and their assistance staff), non-assistance working categories (workers from metallurgical and chemical industries, shipped seamen), hospital assistance personnel, dialyzed and transplanted renal patients, blood donors. The results obtained showed a considerable variability of HBV infections among the examined groups of population. In particular, the frequency of HBsAg and/or anti-HBs detection appeared to be significantly affected by each of the following epidemiological parameters: geographical area, sex, age, pregnancy, life in communities and contacts with hepatitis patients, mental deficiency, non-assistance working activities, assistance activity in the hospital environment, hemodialysis and transplants, selection of population groups by HBsAg screening.


[In vitro studies on megakaryocytes.-I-].

Normal rat's recent bone marrow has been suspended in an isoionic, oxygenated, warmed solution; platelets production by megakaryocytes has never been verified.


[Glucose tolerance and insulinemia in patients with hepatic cirrhosis and portal hypertension treated by portacaval anastomosis].

Development of diabetes mellitus is a common complication of side to side porta-caval anastomosis (PCA). Five patients with liver cirrhosis and portal hypertension have been studied with intravehous (IVGTT, 0,5 g/Kg B.W.) and oral (OGTT, 1 g/Kg B.W.) glucose tolerance tests before and three weeks after PCA. Fasting plasma glucose was 84 +/- 7 before and 87 +/- 3 mg/dl after PCA. Fasting IRI increased from 17 +/- 3 to 31 +/- 6 microU/ml. The pattern of plasma glucose and IRI response to IVGTT did not change after PCA. Plasma glucose resonse to OGTT after PCA showed only an earlier rise at 60 instead of 90 minutes, whereas IRI resonse (area under the insulin curve) was significantly enhanced (from 12.4 to 19.8 U/l, p < 0.05). These data suggest a role of gut polipeptides in determining hyperinsulinemia and insulin resistence in PCA patients.


The retrograde transport of horseradish peroxidase: problems in the interpretation of its ultrastructural aspects.

In this study we consider critically the use of HRP in research on the ultrastructure of the Central Nervous System. In fact, although controls make by optical microscope on semi-thin sections made us certain that some of the neurons were definitely marked with the enzyme, when the same specimen was observed by electron microscope, in no case was it possible for us to distinguish any particular aspect of the ultrastructural morphology of labelling within neurons.


The importance of K. E. Tsiolkovskii's ideas in the formation and development of space medicine.

The importance of K. E. Tsiolkovskii's ideas in the formation and development of space medicine is argued. The author analyzes K. E. Tsiolkovskii's science fiction writings and his basic researchs in aerodynamics and rocket techniques and shows that, besides the technical aspects of the problem, Tsiolkovskii penetrated deeply into the nature of the biological phenomena and revealed their essentials in a series of short descriptions. Tsiolkovskii argued convincingly in support of the view that man can withstand the action of factors of space flight and, step by step, can conquer cosmic space.


Oxidation of tryptophan-P-1 and P-2 by beef liver catalase-H2O2 intermediate: comparison with horseradish peroxidase.

Tryptophan-p-1 (trp-p-1) and p-2, which have high mutagenic and carcinogenic potential, are oxidized by catalase- and horseradish peroxidase (HRP)-H2O2 intermediates with optimum pH 5.9 (0.2 M-acetate) in catalase and pH 5.0 (0.2 M-acetate), 8.0 (0.01 M-phosphate) in HRP. The rate constants (k4) of the oxidation in the catalase at pH 5.9 (0.2 M-acetate) were 2965 M-1 x sec-1 for trp-p-1 and 576 M-1 x sec-1 for trp-p-2. In the case of HRP, 1894 M-1 x sec-1, (pH 5.0, 0.2 M-acetate) for trp-p-1 and 705 M-1 x sec-1 (pH 8.0, 0.001 M-phosphate) for trp-p-2 under each optimum condition. The oxidation products of trp-p-1 and p-2 by catalase or HRP lost completely their mutagenic potential in the mutation assay.


Single cell analysis of changes in electrokinetic properties of a growing ascitic tumor.

An ascitic tumor (SEWA) induced by polyoma virus in A.SW mice was analyzed in vivo as well as in vitro with regard to the electrophoretic mobility (EPM) which may be considered as a reliable criterion of surface charge. After the i.p. transplantation of 10(5) cells, the EPM decreased up to 14th day. Then, the mobility gradually increased with the age of the tumor. In the first phase of tumor growth, we have considered the possibility that immunoglobulin cell coating may be responsible for the decrease in EPM. In the late phase of SEWA growth, the progressive increase in EPM might be due to a rearrangement of sialic acids on the outer part of the cell membrane.


Studies of lymphocyte adenosine deaminase activity in patients with renal and transitional cell carcinoma.

Adenosine deaminase (ADA) is a critical enzyme in purine metabolism and lymphocyte ADA activity is specifically related to immunocompetence in man. Since immunologic factors are relevant in patients with renal and transitional cell carcinoma, we studied lymphocyte ADA activity in these patients. In renal adenocarcinoma patients lymphocyte ADA activity was reduced. Such reductions were most marked in low-as compared to high-stage lesions. Nephrectomy resulted in a rise and disease progression in a decline in ADA activity. In contrast, bladder, carcinoma patients showed elevated lymphocyte ADA activity most marked in high-stage lesions. Disease progression was associated with a rise and tumor resection with a decline in lymphocyte ADA activity. Discordance in patterns of lymphocyte ADA activity when patients with renal and transitional cell carcinoma are compared suggests unique host-tumor interactions at the enzyme level. Studies of ADA may offer insight into molecular aspects of immune mechanisms.


Adjuvant immunotherapy.

Because systemic spread occurs early in the growth of many malignancies, control of occult micrometastases must be an integral part of cancer treatment. For this reason, surgery and radiation therapy alone may fail to achieve a cure despite eradication of the primary tumor. Chemotherapy is potent and systemic in its effects but kills tumor cells by first-order kinetics so the last cancer cell may not be eliminated. An agent is needed that can selectively attack and destroy small numbers of tumor cells on a systemic basis without a significant increase in toxicity. Experimental observations indicate that immunotherapy could fill this role. Immunotherapy has been tested as an adjuvant to surgery, radiation therapy, and chemotherapy, and is clearly beneficial for selected cancer patients. There are many unresolved questions regarding the underlying mechanisms as well as the practical application of adjuvant immunotherapy, but the initial investigations indicate that it could play a vital part in the treatment of cancer. There is evidence that stimulation of host resistance can result in control of systemic micrometastases.


Repeatability and validity of a modified activities of daily living (ADL) index in studies of chronic disability.

In order to measure disability in a randomised controlled trial of different intensities of rehabilitation following stroke, a modification of existing methods has been developed; it makes use of 17 items of activities of daily living (ADL) which are rated on a three-point scale, and it has been subjected to tests of repeatability and validity. While some activities (e.g. use of taps, ascending or descending stairs) are either redundant or repetitive, others provide independent measures of disability. There was no significant inter-observer variability; the assessors disagreed on 78 (3.7%) out of a total of 2,125 paired observations. In a study of short-term within-patient variability, different scores were assigned on 49 (14.4%) out of a total of 340 observations made on two separate occasions. Minor differences (mainly in activities involving equipment e.g. cookers) emerged when scores obtained in hospital were compared with those obtained at home, but the two sets of scores were still highly correlated (r = 0.962. There was, however, considerable discrepancy between the hospital scores and those derived from the patients' own estimates of their activities at home, the latter falling below actual capabilities as indicated by the hospital scores. A clinical validation of the index showed a significant association between the hospital ADL scores and the extent of cerebral lesions determined by the number of neurological deficits. This modified ADL index is sufficiently repeatable and valid for the assessment of patients with moderate disability as a result of stroke and other chronic diseases; in most circumstances, it can probably be simplified to include only five or six items.


Are hospital assessments of daily living activities valid?

The level of functional achievement gained during a rehabilitation programme provides the basis for supplying aids and requesting community services on discharge. In a study of follow up regimes for patients with rheumatoid arthritis a comparison was made between functional assessments in hospital before discharge and at home shortly after discharge. A small number of the activities assessed showed a significant change at home and these changes were all towards a lower level of independence.


Influence of the vagus and splanchnic nerves on insulin secretion and glycemia.

The role of the autonomic nervous system in control of the acute and the late-phase of insulin secretion was studied in mongrel dogs before and after bilateral severance of the vagus, splanchnic, and vagus plus splanchnic nerves. Glucose-stimulated acute insulin secretion increased after splanchnicotomy or transection of both autonomic nerves but remained unchanged after vagotomy alone. Late-phase insulin secretion was not altered by transection of any of the nerves alone or in combination; similar results were obtained as to fasting insulin levels. In contrast, fasting glycemia was increased after vagotomy and decreased after splanchnicotomy. These findings disclose tonic sympathetic and parasympathetic influences on blood glucose basal concentration and indicate an acute inhibitory role of the sympathetic system on insulin secretion.


Problems of reconstruction in neurosurgical patients. (The use of boiled bone in cranioplasty).

The authors report their experience in six cases of head surgery for the simultaneous reconstruction of skin, bone and dura mater. They recommend the use of teflon as a dural substitute and the autogenous bone opercolum, boiled to have it free from cancer cells or infection.


Evidence for a role of exogenous or endogenous hyperlactatemia in insulin secretion in the dog.

Various types of experimental hyperlactatemia were induced in the normal anesthetized dog, and the changes in insulin secretion were measured in the pancreatico-duodenal vein. Hyperlactatemia was induced in the absence or in the presence of an infusion of sodium dichloroacetate (DCA), which activates pyruvate dehydrogenase. 1. Exogenous hyperlactatemia: The infusion of sodium L(+)lactate resulted in a strong increase in blood lactate level which was accompanied by a significant increase in the insulin output from the pancreatico-duodenal vein. The administration of DCA did not counteract the increase in lactate level and did not modify insulin output either. 2. Endogenous hyperlactatemia: This was induced either by pharmacological means: the subcutaneous injection of an antidiabetic biguanide, phenformin (20 mg/kg), or by physiological means: intense muscular work. In both cases an increase in the lactate level and in insulin output was recorded. The administration of DCA suppressed the hyperlactatemia and counteracted the increase in insulin output. These results show that there is a relationship between lactate level and insulin secretion, and give evidence for a role of endogenous lactate in the regulation of insulin secretion.


The history of vocational training for general practice.

We feel that it is worth recording the story of how vocational training for general practice was first proposed, how the earliest experiments were started, and how this prolonged exercise in teamwork developed throughout the UK. It is appropriate to do this now that Parliament has recently voted that this training should be an obligation for all doctors who wish to work as general practitioner principals in the NHS. Moreover, the first person to exert a crucial influence, Henry Cohen (Lord Cohen of Birkenhead) has recently died.We write this account in historical sequence, not comprehensively, but selecting what in retrospect we believe to have been of chief importance. We describe initiatives at first unrelated to each other, but all contributing to one end. As the story unfolds, so does coordination in the common effort. The account ends at 1970.


Clinical assessment of laboratory rodents on long term bioassay studies.

The disease status of laboratory rodents should be clinically assessed before the animals are placed on toxicological bioassay programs. This is especially important when the stress of dietary or parenteral intake of toxic substances may trigger the clinical onset of latent diseases in research animals. In clinical evaluation of rodents, the environmental influence on biochemical, physiological and behavioral status of the animals must be continually monitored. Temperature, humidity, ventilation, lighting, and the microenvironment of the cage will all influence, independently or in consort, the response of the animal to various microbial or chemical insults. Unwanted variables in the diet can also markedly after the biological response of the animal and thus alter interpretation of experimental data. Adequately trained personnel, both professional and technical, must be available to provide daily care, clinical observation, and necessary treatment if signs of illness are noted in the laboratory rodent or bioassay experimentation. Clinical signs associated with commonly encountered diseases in laboratory rodents are briefly described. Clinical surveillance and assessment of rodents in part consists of recognition of and detailed recording of clinical signs, coupled with proper diagnostic resources to substantiate clinical observations. It is possible, with proper diagnosis, to evaluate the overall effect of a particular disease on the animal's health, the likelihood that the disease is jeopardizing the health of the other animals on test, and the effect of the disorder on interpretation of experimental results.


[Use of simethicone in the prevention of postoperative abdominal discomfort and gastrointestinal distension after cesarean section].

A double blind trial was performed in patients with Cesarean section in order to study the effect of Simeticon (Stuart Pharmaceutical Company, Pasadena, California) on the occurrence of subjective and objective signs of gas distress during the immediate postoperative period. The results obtained with Simeticon show a highly significant reduction of the analysed subjective complaints (nausea, vomiting, meteorism, discomfort in the stomach, abdominal pains) in relation to placebo. Peristaltic movements in patients treated with Simeticon appeared in the first two days in 100% of cases and only in 30% in the placebo group. Flatulence also appeared in all the patients receiving Simeticon, in contrast to only 20% in the placebo group. There was no difference in spontanous defecation between the groups. On the basis of the results obtained, and considering the non-toxicity of the drug, its chemical inertnees, good tolerance, and simple use, the authors consider simeticon very useful for the prevention and therapy of postoperative discomfort due to gas accumulation and gastro-intestinal distention after Cesarean section.


Endothelial cell density determined by specular microscopy and scanning electron microscopy.

Human eyes were photographed with a specular microscope and later examined wit a scanning electron microscope. Corneas from patients undergoing corneal transplantation in whom we were able to obtain preoperative specular micrographs were similarly analyzed. An attempt was made to correlate the counts obtained with both microscopic techniques by determining the amount of shrinkage the cornea undergoes while being processed for SEM. All specimens were counted with a planimeter. We found that the specular microscope adequately analyzes the endothelial cell density in the central and paracentral cornea of a normal eye, but because of its small sampling area specular microscopic counts are subject to significant error when dealing with nonhomogeneous populations such as postoperative cases. We found the peripheral corneal endothelial density to be less than the central endothelial density. Furthermore, we found that we could maximize the accuracy of counting by using a variable frame in a nonhomogeneous population, counting a minimum of four photographs per specimen, analyzing different areas, and analyzing larger areas.


Lateral canthal tendon tuck.

Senile and involutional entropion is occasionally associated with a marked relaxation of the canthal tendons. A simple adjunctive procedure to the imbrication of the lower lid retractors for the correction of senile entropion is described. This adjunctive procedure--the lateral canthal tendon tuck--should further reduce the remarkably low recurrence rate associated with the imbrication surgical procedure that directly corrects the pathophysiology of senile entropion.


Superior tarsal muscle resection to correct blepharoptosis.

Resection of the superior tarsal muscle (STM) is effective in correcting congenital or acquired blepharoptosis in patients who have satisfactory elevation of the eyelid with a preoperative phenylephrine eye drops test. Advantages of this procedure are that only the STM is resected, the conjunctiva and basic lacrimal secretors are preserved, tarsal stability is maintained, no special instruments are required, and the preoperative phenylephrine eye drops test reliably predicts the postoperative result.


Inheritance of Fuchs' combined dystrophy.

The inheritance pattern of Fuchs' combined corneal dystrophy is not confirmed. Published pedigrees fail to demonstrate a 50% segregation and sex ratio. They include no more than two generations of affected individuals and indicate a strong, female predilection. The pedigree we will present shows 16 affected persons in four generations. The ratio of affected to unaffected and men to women is 1:1. Penetrance is apparently 100%. Nine of the affected are under 50 years of age; four are subteen age. Light and electron micrographs of corneal tissue from three patients in three different generations are consistent with the diagnosis of Fuchs' dystrophy. Fuchs' dystrophy can therefore be established as a classic autosomal dominant pattern.


[Geographical hematology and population dynamics].

Hemotypology, which is based on the study of a large number of immunological and enzyme systems in the blood, has shown the extraordinary polymorphism of the human species and the lack of a genetic barrier between groups once considered as separate races. The typological mode of thought predominated in anthropology until the middle of this century. Mankind was divided into races according to a theoretical profile characteristic of each one, the holotype, which all the members of the same race were thought to resemble. Today we tend toward the substitution of population thinking: the human species, like all the other animal or plant species, is made up of populations, reproductive units whose members are more likely to mate within the group than outside it. A population is never totally closed and it is the interpopulational genetic flux which assures the homogeneity of the species. Three factors play a fundamental role in the genetic structure of human populations: 1. An ancestral genetic heritage from the distant past is modified by external contribution such as genetic flux and hybridization; 2. Chance is an especially important factor in very isolated small groups; 3. Natural selection: the majority of all genetic factors are not neutral, as we used to think, but possess a certain selective value. This nonneutrality doubtless explains the maintenance of the hemotypological polymorphism in man, as in the model proposed by A.E. Mourant and J. Ruffié. Following these ideas, sometimes it is possible to find the hemotypological traces of important events, especially of the great migrations of the beginning of the neolithic or the beginning of the historic period. Examples are cited which concern the peopling of sub-Saharan Africa, the western Mediterranean and western Europe, and of the continental Far East and Japan. This conceptual revolution, based on the dynamic idea of populations and not on that of the typological conception of race, has shed new light on the science of anthropology and has bridged the gap between hematology and history.


[The platelet membrane: some aspects of the pathophysiology of haemostasis].

Platelet membranes play a key role in all stages of the haemostatic mechanism. Four of these in particular are considered here: adhesion to subendothelium, which involves an interaction between the glycoprotein I complex in the platelet membrane (deficient in the Bernard-Soulier syndrome) and plasma factor VIII; aggregation, involving the membrane glycoprotein IIb/IIIa complex (deficient in thrombasthenia), plasma fibrinogen and divalent cations; platelet factor 3 availability, a function of surface membrane phospholipids; and thromboxane synthesis, a function of the phospholipids of the membrane of the dense tubular system. The glycoprotein I complex also carries binding sites for thrombin and for drug-dependent antibodies, and glycoprotein IIb/IIIa is the site of the P1A1 antigen and of alpha-actinin.


[Immunologic factors and platelet vessel wall interactions (author's transl)].

Platelet subendothelium interaction is an essential step in thrombosis and hemostasis which can be modulated by immunoglobulins, immune complexes, complement, and leukocytes. Antiplatelet antibodies can induce thrombocytopenia which is accompanied by a reduced vascular wall thickness and an increased fenestration. Antigen-antibody complexes can activate platelets inducing platelet release and aggregation. This reaction is amplified by the first component of complement C1q. Cytotoxic antibodies directed against endothelial cells have been observed in transplantation. These antibodies can be directed against HL-A antigens or specific endothelial antigens. Anticollagen antibodies have been detected in patients with leprosy. The C1q component can inhibit adhesion of platelets to collagen and platelet aggregation induced by collagen. The association of acquired or congenital C1q deficiency and vasculitis has been reported. C3a is taken up by endothelial cells and metabolized. C3a and C5a can modify vessel wall permeability and activate granulocytes which can become toxic for endothelial cells. Leukocyte cationic protein can reduce platelet aggregation. An anti-von Willebrand antibody could be the origin of hemostatic abnormalities and endothelial lesions. The involvement of immunologic factors in platelet vessel wall interactions is complex. Immune complexes and some antibodies seem capable of promoting thrombosis, while a component of complement (C1q) may also have an antithrombotic role.


[Arterial subendothelial structures: anatomy, biochemistry, functions].

This review summarizes the main structural and biochemical features of the fibrillar constituents of the subendothelial layers of the arterial wall. Several constituents are directly identified by various histochemical methods and electron-microscopic studies. (1) The microfibrils (MF), stained by tannic acid, cationic stains such as ruthenium red, and various peroxidase-labeled lectins are mostly found in association with elastin within the internal elastic lamina (IEL). They have been characterized by chemical analysis as acidic glycoproteins, hydrolyzed by a variety of proteases, but resistant to collagenases. The endothelial cells seem to participate in their biosynthesis. (2) Elastin (El), which is the main constituent of the IEL, forms a wide, concentric, electron-lucent, tannic-acid-stainable zone. Fibrous El results from the association of tropoelastin (or proelastin) molecules by intermolecular cross-linkage. During the elastigenesis, this cross-linkage occurs directly between tropoelastin molecules which have been previously sterically oriented by the MF probably synthetized by the same cells (smooth muscle cells and possibly endothelial cells). (3) Interstitial collagen forms sparse fibers characterized by their cross-striation (with a periodicity of 640 A). They are relatively resistant to most proteolytic enzymes, except collagenases. They result from the intermolecular cross-linkage of rigid molecules, resulting themselves from the intramolecular cross-linkage of three helical alpha chains as a triple helix. The interstitial subendothelial collagen has been identified by indirect immunofluorescence as a type III collagen. The same technique has also been used to detect type IV collagen and fibronectin. This glycoprotein could play a role in the attachment of the endothelial cells to the fibrillar network of the subendothelium, despite an affinity which is greater toward denatured collagen than toward native collagen. One of the most important functions of the subendothelium is its role in thrombogenesis, in which both MF and collagen are involved. In type III collagen, this property is linked to the preservation of an ordered structure in which a 9-amino acids fragment, localized in the central part of each chain, could bear an adhesion site.


Comparison of a high performance liquid chromatographic and an enzyme immunoassay technique for quantitation of theophylline in serum.

High performance liquid chromatograhic (HPLC) and enzyme immunoassay (EMIT) methods for quantitating theophylline concentrations in serum were evaluated. For both methods, standard curves were linear over the therapeutic range of serum concentrations. Precision was acceptable, with coefficients of variation being less than 9%. The HPLC assay was slightly, but not significantly, more precise. No interference was noted in either method by caffeine, theobromine, diphylline, 8-chlorotheophylline, or by metabolites such as 1-methylxanthine, and 3-methylxanthine, or by potentially interfering compounds such as urea and uric acid. The two methods correlated well, with a correlation coefficient of 0.98%. The enzyme immunoassay was superior in terms of lower costs, greater ease of performance, and potential for automation.


Rotating grating treatment for amblyopia.

The recently published method of treatment of amblyopia by the use of rotating gratings is very similar to an older technique. Used apparently extensively during the 1930s in the United States, the method, called 'visual gyration' was based on use of a rotating disk pattern like a grating. Differences between the old and new procedures are described in this paper.


Nonvisualized ("phantom") renal calyx: causes and radiological approach to diagnosis.

A calyx which fails completely to opacify on excretory urography (phantom calyx) is often the harbinger of serious underlying renal disease. Causes of a phantom calyx include tuberculosis, tumor, calculus, ischemia, trauma, and congenital anomaly. The pathologic basis for the radiographic findings in each of these entities is described and an overall approach to diagnosis is set forth.


Definitive identification methods: antibiotic sensitivity and microtube system.

The definite identification of species and subspecies of an anaerobe implies certain difficulties, such as the poor and slow fermentation of carbohydrates under anaerobic conditions and the fact of having many keys in common. As a result several tests are required and as the number of tests increases the chances of error and the number of variables also increase. Hence specific methods have been developed in order to try and obtain satisfactory results. The A. refers his experience and judgement on V.P.I. and A.P.I. and on identification based upon antibiotic sensitivity spectrum. When properly used, such techniques enable the species and subspecies of non-sporing anaerobes to be more easily identified.


Metronidazole in the prevention and treatment of anaerobic sepsis.

Clinical trials were carried out in order to determine the value of metronidazole in preventing the development of anaerobic infections after surgery. Following a successful controlled trial of hysterectomy patients, among whom the prophylactic use of oral metronidazole resulted in a reduction of the anaerobic sepsis rate from 25% to nil, further trials were carried out with patients having urgent appendicectomy, those having elective colonic surgery and pregnant women having delivery by the vaginal and caesarean routes. These studies were conducted as double-blind trials in which metronidazole was compared with a placebo; patients were randomly allocated to the two "drug" groups. Since completion of the hysterectomy trial over 618 hysterectomies have been performed under metronidazole cover, none of which were complicated by anaerobic sepsis. Among appendicectomy patients, anaerobic infection did not develop in any of the 49 patients who received prophylactic metronidazole, but bacteriologically confirmed clinical anaerobic infections developed in 9 (19%) of 46 control patients. Since completion of the trial over 1098 appendectomies have been performed under metronidazole cover, only two of which developed an anaerobic infection. Among colonic surgery patients, anaerobic infections did not develop in any of 27 patients who received prophylactic metronidazole, but bacteriologically confirmed clinical anaerobic infections developed in 11 (58%) of 19 control patients. Since completion of the trial over 126 colonic operations have been performed under metronidazole cover, none of which were complicated by anaerobic sepsis. Pregnant women having vaginal delivery were not especially prone to anaerobic infections so that metronidazole prophylaxis is not indicated in these patients. Delivery by caesarean section appears to carry a risk of post surgical anaerobic sepsis in about 20% of patients not protected with metronidazole prophylaxis. Metronidazole is regarded as the drug of choice for the treatment of those non-clostridial anaerobic infections that require antimicrobial therapy. It may be given orally, rectally, intravenously and topically, has virtually no side effects and its use is characterized by a strikingly rapid and sustained clinical and microbiological response.


[Intestinal bacterial flora in normal adults].

In this preliminary study we have examined 12 healthy men aged between 20-60 years, by three specimens each. All the isolated could be assigned to genera by biochemical tests and gas-liquid chromatography. The results showed a 10(8)/g concentration of aerobe bacteria in faeces and a 10(10)/g concentration of anaerobe non sporing bacteria. The results of the count of Clostridia showed a variability among the examined individuals. The predominant groups of aerobes in the faeces were found to be E. coli and S. faecalis spp. and the predominant group of non sporing anaerobes were Bacteroides and Bificobacteria. These results were similar to the data obtained from foreign AA., showing the predominance of anaerobes in the faeces and particularly of Bacteroides.


Anaerobic sepsis.

Anaerobic bacteria are the major residents of the skin and mucous-membrane surfaces, it is reasonable to suspect therefore, that these organisms play a part in the pathological processes associated with disturbances of these sites. The improvements in laboratory methods and the clarification of taxonomy have resulted in an increased awareness of the prevalence and virulence of the non-sporing anaerobic organisms in clinical infections. In this paper, only a brief outline of the types of infections associated with the normal flora and the types of bacteria isolated from these infections are given. Finally some of the pathogenetic mechanisms of anerobic infections are discussed.


[Methods for collection, transport and culture media].

A crucial factor affecting the ultimate success of anaerobic cultures is a proper specimen collection, with care to avoid inclusion of normal flora often present on human mucosa. In general, material for anaerobic cultures is best obtained using a needle and syringe, from which the air must be expelled. Then the specimens should be placed immediately into an anaerobic transport broth and then in suitable culture pre-reduced media.


[Technics for isolation, incubation and preliminary identification tests].

In this report the AA. emphasize the fact that anaerobes are mostly isolated from mixed cultures in which several bacteria are present. Therefore they suggest to grow all the bacteria under the best conditions and consequently to select the anaerobes from the aerobes. Furthermore they describe the selecting techniques used at Istituto Superiore di Sanità and Clinica Medica III, to attain this aim and enumerate the best methods used for anaerobic incubation.


Intestinal bacterial flora in normal adults in the U.K.

The A. reports on the composition of the bacterial flora being present all through the intestine of normal adults in the United Kingdom, listing the number and families of the aerobes and anaerobes occupying the various portions of the alimentary tract. Emphasis is then laid on a comparison between the normal "British" flora in the colon and rectum, where the ratio of anaerobes to aerobes is 100 to 1, and the flora found in normal adults in Africa, India and Japan, stressing the major differences in the numbers of clostridia and non-sporing anaerobes. The A. finally highlights the importance of the factors governing the intestinal bacterial ecology, as well as the serious consequences likely to arise from the alteration of such flora.


[A definitive identification method: gas-liquid chromatography].

The definitive identification of many anaerobes requires the use of gas-liquid chromatography to detect alcohol and volatile acids end-products of their metabolism. In this study we have used the gas-liquid chromatography for the identification of 360 non sporing anaerobes isolated from faeces of healthy individuals. These analyses were performed on a Variant-Aerograph mod. 2700 gas chromatography fitted with a column without phosphoric acid. The results showed a good percentage of typing (83%).


[Modifications of the fluorescence method for detecting salmonella in feces].

The Authors illustrate two modifications of the indirect method for identifying Salmonellae on faeces using fluorescent antibodies. They compare a Commercial polyvalent serum with serum containing only the fundamental antigens of groups B, C and D of Kauffmann-White with the aim of reducing the phenomenon of aspecificity. In order to reduce the time required for this test they substitute the enrichment of the specimen in broth by filtering, first the specimen of faeces and then, successively, centrifuging the filtrate. These two modifications have been demonstrated satisfactorily when the test is carried out in children with active gastroenteritis.


Immunological markers in non-Hodgkin's lymphomas.

Membrane markers of lymphomatous cells were studied in 33 patients with non Hodgkin's lymphoma and correlated with morphological diagnosis according to Rappaport's classification. Nodular lymphomas and the majority of lymphocytic lymphomas showed B cell characteristics, whereas only 6 out of 23 with diffuse pattern were B. None of the histiocytic lymphomas were B, 3 were T, and 4 non T-non B. Mixed lymphocytic/histiocytic lymphomas showed different immunological patterns (B, T, non T-non B, B and T). These results confirm the importance of functional classification, which can clarify the pathogenesis of lymphoma.


[Insulin response and NEFA behavior in volunteers with a flat response to oral glucose tolerance test].

The insulin response and the NEFA behaviour of 7 lean and 8 obese subjects with a flat response to an oral glucose tolerance test have been studied. A flat response has been defined as one in which the maximum glycemic increase and the area of increase does not exceed 32 mg% and 18 mg% respectively. The insulin response and the NEFA behaviour were similar both in lean and in obese subjects to controls with normal O.G.T.T. The glucose/I.R.I. ratios were increased. A possible physiopathological interpretation is proposed.


Regulation of endogenous proteolysis in rat liver slices.

Methodological difficulties limit studies on cell protein catabolism both in intact animals and in vitro. We have studied the rate of protein degradation by measuring in vitro the release of acid-soluble radioactivity from rat liver slices and tested some factors that control the process. We found a rate of protein degradation of 6.5, or 2% per hr after 1 or 15 hrs of labelling in vivo during the first 90 min. These results indicate that a correlation exists between the rate of production of acid-soluble radioactivity by liver slices and the fast-or slow-turnover rate of the liver proteins. Cyanide and fluoride greatly inhibit the production of acid-soluble radioactivity from both slow- and fast-turnover proteins. Glucagon increases this production while insulin shows an opposite effect. Our preliminary investigations show that liver slices are a suitable surviving medium to study protein catabolism and its modifications under physiological and pathological stimuli.


[Lipids of Candida lipolytica cultivated in n-alkanes by the industrial method ("Toprina")].

The following lipidic classes are examined in the present study: Total Lipids, Phospholipids, Neutral Lipids, Sterols, and Carotenoid Pigments from dried biomasses of Candida lipolytica grown on n-alkanes by industrial process following the BP technique ("Toprina"). The composition of the lipid classes examined in "Toprina" agree generally with bibliographic data about n-alkanes grown Candida lipolytica in batch cultures.


[Higher fatty acids of Candida lipolytica grown in n-alkanes by the industrial method ("Toprina")].

The present study deals with the composition of superior fatty acids of total lipids, polar lipids, and neutral lipids from dried biomass of Candida lipolytica grown by industrial process ("Toprina") on n-alkanes (C10-C20) extracted from petroleum. The data related to our knowledge about yeast and Candida lipolytica, lead to the conclusion that fatty acids feature of "Toprina" are similar to the Candida lipolytica ones grown in batch culture at the same conditions. In addition, a possible physiologic role of 17:1 and 17:2 is considered, in the perspective of the utilization of "Toprina" in animal food.


[Unusual fatty acids in turkeys fed a diet containing "Toprina". I. Composition of the higher fatty acids in "Toprina", the diet, feces and blood].

Totals lipids (TL) phospholipids (PL) and fatty acid composition of TL and PL (the latter in blood only) were estimated in Candida lipolytica cultivated on n-alkanes by industrial method ("Toprina"), in 0%, 10% and 15% "Toprina" diets and in faeces and blood of turkeys, males and females, fed these diets. With increasing concentrations of dietary "Toprina" phospholipids and 15:0 and 17:0 fatty acids increased, 17:1 and 17:2, typical of the product, appeared and increased in diets and blood. Other lipid and fatty acids values were not affected by dietary yeast.


[Behavior of plasma cortisol during testing with insulin and with LVP in obese subjects compared to normal subjects after resperine administration].

The behaviour of plasma cortisol levels was studied in fifteen overweight subjects with comparison to normal subjects. In eight subjects the insulin hypoglycemic test was performed before and after medication with reserpine (4mg/24HR); the other seven subjects were tested with LVP before and after treatment with reserpine. In both cases, premedication with reserpine significantly reduce the cortisolemic response. This behaviour is similar to the response observed in normal subjects.


[Acetylsalicylic acid and hormonal response in insulin induced hypoglycemia].

The influence of a short-term treatment with acetylsalicylic acid (ASA 3,2 g/daily), an inhibitor of endogenous prostaglandin synthesis, on plasma glucose, glucagon and growth hormone responses to insulin-induced hypoglycemia, has been investigated in seven subjects. ASA caused a slight but significant reduction in basal glucose levels, but did not alter the pattern of glucagon and growth hormone secretion following hypoglycemia. On the basis of these results, it is hypothesized that endogenous prostaglandins are not implicated in the response of pancreatic alfa-cell to hypoglycemia.


[Vascular alterations and GH secretion in latent chemical diabetes].

The AA. have investigated the relationship between the secretion of GH and diabetic angiopathy a group of 17 subjects with chemical diabetes during a standard dexamethasone os i.v. glucose test. The results show that functional subclinical microangiopathy was present in the majority of the diabetics studied, who also showed an exaggerated growth hormone response to glucose. Thus, these results suggest that a positive correlation exists between alterations in the secretion of growth hormone and the development of diabetic microangiopathy.


[Surface immunoglobulins (SmIg) in human B-lymphocytes: effect of enzymatic digestion].

In order to determine the number of circulating B lymphocytes which can synthetize their surface membrane immunoglobulins, we have evaluated by immunofluorescence their presence before and after enzymatic exposure to pronase. After pronase treatment the majority of lymphocytes carrying SmIg has been disappeared (from 7.8% to 1.9%; p < .0.0005). After 18 hours incubaton only a small proportion (4.6%) of B lymphocytes risynthetized their SmIg. This observation support the hypothesis that a subset of lymphocytes present in the peripheral blood carries on its membrane only cytophilic SmIg and therefore may interfere in the determination of the number of B lymphocytes.


A trial of house dust mite extract in bronchial asthma. Mite Allergy Subcommittee of the Research Committee of the British Thoracic Association.

Patients with asthma considered to be due to house dust mite allergy were allocated at random to treatment with (a) increasing weekly injections of house dust mite extract for 18 weeks followed by monthly injections to complete 18 months of treatment; (b) similar injections for 18 weeks followed by placebo injections up to 18 months or (c) placebo injections for 18 months. Fifty-six patients completed at least six months of observation. In patients not on corticosteroids the treated group did a little better than the controls as judged by night asthma scores, discontinuation of bronchodilators and overall blind assessment of the records by a panel of independent physicians. No benefit was apparent by extending treatment from 18 weeks to 18 months. In contrast, patients on corticosteroids given placebo injections did a little better than the treated group. The extract used was stronger than the commercially available preparation and the injections had to be stopped in one-sixth of the patients because of side-effects. The improvement in patients not on corticosteroids in this trial was of doubtful clinical importance.


Long-term comparison of salbutamol powder with salbutamol aerosol in asthmatic out-patients.

Salbutamol dry powder was compared with salbutamol aerosol in 38 asthmatic patients. The study was double-blind and took place over six months. Salbutamol powder in a dose of 200 micrograms per capsule was able to control asthma as well as the aerosol, but some patients needed to increase the frequency of dosage when using the powder. The device used for powder administration, the Rotahaler, was well accepted and was preferred to the pressurized aerosol by one-third of patients. Dry powder administered by Rotahaler allows salbutamol to be given by inhalation to many patients previously using aerosols inefficiently.


Continuous and intermittent salbutamol tablet administration in asthmatic children.

We studied 22 asthmatic children aged seven years two months to thirteen years eight months over a four-month period. Each child received two months continuous and two months intermittent salbutamol tablets using a double-blind cross-over technique. No significant clinical differences were found between the two treatment regimens as judged by daily diary card scores. Daily PEFRs (both a.m. and p.m.) were significantly higher (P < 0.05) when the children were receiving continuous salbutamol and this was more obvious in the eleven children under ten years old. Lung function tests performed monthly in hospital showed no significant differences between the two treatment regimens.


Primary culture of a primordial cyst from a case of Gorlin's syndrome.

The tissue culture characteristics of a primordial cyst are described and compared with normal oral mucosa. The potential application of this method to other aspects of oral biology is suggested.


[Mitotic index modifications in a series of gliomas related to degree of malignancy].

We have measured on semi-thin sections, the mitotic index in 5 benign gliomas and 5 malignant gliomas among a whole of about 80,000 cells in each group, divided into fields of 750 cells on an average. We have differentiated between normal mitoses and abnormal mitoses on one hand, between viable and adequate mitoses and non-viable mitoses on the other. If we take into account the total number of mitoses, the mitotic index is not greatly different between the 2 groups of tumors (about 5 per thousand), although slightly superior in the benign gliomas. If we take into account the viable or adequate mitoses only, the mitotic index is greatly superior among the benign gliomas. These results are discussed according to other data related with the kinetics of proliferation of gliomas and according to the possibility of cellular fusions as a process of a minor spreading of malignant gliomas.


[Applications of the urocytogram in primary-secondary amenorrhea in adolescents].

In the urinary sediment, the cellular material mainly originates from cells of the bladdertrigone. These cells are submitted to hormonal stimulation and their study constitutes the base of a cytological method called "urocytogram". The urinary sediment was examined in thirty-five young girls with backward puberty. The repeated examinations contribute to differential diagnosis and help in etiologic diagnosis. Whenever it is necessary to investigate adolescent's sex hormones, an urocytogram, a simple and painless method, is indicated.


[Lymphatic system of the human testis].

The distribution of lymph vessels in the human testis was investigated using ink injection methods, light and electron microscopy. Lymph capillaries occur in the septula testis but are absent in the intertubular tissue. They consist of endothelial cells provided with an incomplete basal lamina and bound by anchoring filaments to the adjacent connective tissue. Frequently, the endothelial cells are separated by gaps (measuring up to 2 microns). The lymph capillaries of the septula testis are connected to lymph vessels in the rete testis and tunica albuginea. These vessels have occasional smooth muscle cells and valves. At the posterior margin of the testis, the network of lymphatics merges into collecting ducts that together with vessels derived from the rete testis are drained by lymphatics in the spermatic cord.


[Advantage of phase contrast for the identification of the cellular constituents of urinary sediment].

Phase contrast microscopic observation of the urinary sediment has to be performed on freshly collected urine. This technique, which permits an excellent definition of the cells and the maintenance of intra cellular motility, gives therefore a great accuracy in differential diagnosis, especially for little round cells. Among these, polynuclear granulocytes are easily recognized, because of their lobulated nuclei and of their numerous intra cytoplasmic motile granulations. Lymphocytes and lymphoblasts have round, regular, homogeneous nuclei. Renal tubular cells exhibit eccentric nuclei, with smudged chromatine, and round, refringent cytoplasmic vacuoles. Rapid and easy, this technic should be used for routine microscopic study or urinary sediments.


[Use of the intravisceral graft technic for the study of histologic changes in the skin after freezing].

The authors present their technique for freezing thin skin samples which may be used for intravisceral grafts in the testis, the liver and the kidney to test developing potentials for grafts conserved in this manner. In comparison with fresh grafts, they show that frozen samples not only retained their vitality, but the ability to multiply, differentiate and mature. They eliminate any ambiguities in the interpretation of the results. At the same time, they note that the period spent in liquid nitrogen does not prevent graft rejection in the case of allografts.


[Exploration of possible associations of antineoplastic chemotherapeutic agents in view of their mechanisms of action (author's transl)].

A careful study of the principal multidrug regimes wil reveal in each case the criteria upon which the drug association was based. In this paper the authors emphasize the importance of correlating the parameter, point of attack of the drug, with the parameter, metabolism of the malignant cell, the latter being differentiated into different functions according to thermodynamic criteria and to the particular organization of enzyme systems in the cells. Thus a multidrug association will be the more rational, the greater the number of parameters taken into consideration in its engineering; in these terms the authors outline a method of drug association affording more and more complex combinations and also the replacement of one or more component drugs in the case of resistance phenomena.


[Diagnostic picture of spinal tumors].

A correct classification both primary and secondary of the spinal tumour is given dealing with a present argument. The clinical aspect and The radiology of the different kinds of tumour are specified. Moreover they are classified according to their anatomo-pathological aspect. A complete analysis of the argument is the result of this work.


[Anatomical and functional specialization of the cortex and the organization of gestures. An animal experimental contribution to the study of apraxia].

Apraxia has traditionally been considered the province of clinical investigation, but in recent years a series of animal studies have provided data that appear to be relevant to its interpretation. They are reviewed in the present paper with the aim to integrate and specify the classical model proposed by Liepmann, particularly as far as the roles of the inferior parietal lobe (area 40 in man and part of area 7 in the monkey) and of the motor association cortex (area 6 in man and periarcuate area in the monkey) are concerned. Monkey data suggest that the relation of the inferior parietal lobe to apraxia is not simply due to the interruption of the many sensory pathways that run in the subjacent white matter towards the frontal lobe, as implied by Liepmann's theorization, but rather to its being a center specialized in planning motor programs. Specifically, it would award the gesture with the spatial (directional) features needed to its proper execution. The periarcuate area, on the other hand, would participate in the organization of gesture, programming the temporal sequence of its component movements. It is in a favourable position to do this, because this receives information not only from the sensory association areas and the inferior parietal lobe, but also from the cortex of the depth and around the sulcus principalis, which is committed to keep record of the spatial characteristics of the stimulus as well as of the motor response. The implications of this dual system for the interpretation of apraxia in man are discussed.


Cellular mechanisms of proteinase release from inflammatory cells and the degradation of extracellular proteins.

Neutrophils and macrophages produce, store and release large amounts of various acid and neutral proteinases. The two main proteinases of neutrophils are elastase and cathepsin G. They are localized in the azurophil granules, together with proteinase 3 and the acid cathepsins B and D. In addition neutrophils contain collagenase in the specific granules, acid proteinases in the C-particles and plasminogen activator in organelles with the characteristics of secretory vesicles. The granule-bound proteinases are released during phagocytosis while plasminogen activator is apparently secreted. In macrophages, the acid hydrolases are bound to lysosomes while the neutral proteinases are confined to secretory vesicles. The main mechanism of enzyme release in macrophages is secretion. Lysosomal hydrolases are also released by phagocytosis. Enzyme secretion is a characteristic property of activated or inflammatory macrophages. Macrophages become activated after phagocytosis of certain particles and the metabolic burst appears to be an initial event in the activation process. The action of neutrophils and of purified elastase or plasmin on cartilage was tested. These experiments indicate that neutrophil-mediated degradation of cartilage proteoglycans is largely dependent on elastase.


Inactivation of cytosol enzymes by a liver membrane protein.

Non-proteolytic inactivation reactions have been suggested to play an important role in determining the relative rates of enzyme degradation within cells. An inactivation factor is present at high specific activity in hepatocyte plasma membrane which inactivates cytosol enzymes at rates roughly proportional to their rates of degradation in vivo. This factor has been purified about 100-fold and has similar catalytic selectivity to the crude factor. The inactivation reaction is accelerated by disulphide compounds and can be partially reversed by thiols. Furthermore, inactivation of enzymes is accompanied by a loss of measurable thiols in the enzymes. From these experiments it is concluded that the inactivation factor carries out a disulphide attack on surface thiol groups in cytosol enzymes leading to the formation of mixed disulphides which have lost catalytic activity. The inactive enzymes may be substrates for lysosomal or non-lysosomal proteolysis.


Lysosomes and protein degradation.

Considerable evidence from studies with group-specific proteinase inhibitors, in particular pepstatin, the aspartic proteinase inhibitor, implicates lysosomes in turnover of endogenous cellular proteins. Recent experiments using a new group-specific inhibitor of thiol (cysteine) proteinases, Z-Phe-Ala-diazomethyl ketone, are described. Lysosomal participation is most clearly established for the degradation of long half-life proteins in situations in which turnover is accelerated because of nutritional or hormonal deficiencies. Some evidence indicating their involvement in 'basal' proteolysis is also discussed. Whether lysosomal proteolysis is selective remains to be established, and possible approaches to this question are outlined.


Lysosomal cysteine proteinases.

Cathepsin B has so far been the most investigated cysteine (thiol) proteinase of lysosomes. The use of cytosol proteins as substrates has allowed the detection of two new lysosomal cysteine proteinases from rat liver: the endoaminopeptidase cathepsin H and cathepsin L, which splits almost no synthetic substrates but has a more than 10-fold higher specific activity with proteins as substrates than other mammalian cysteine proteinases. The properties of cathepsin L are compared with those of other cysteine proteinases (cathepsin B,H,N,S and others) from different tissues in relation to substrate specificity and sensitivity to inhibitors. A new test system for determining cathepsin L allows us to investigate the distribution of this enzyme between different cell types and to speculate about the special role of cysteine proteinase in intracellular protein degradation.


Insights into mechanisms of intracellular protein turnover from studies on pinocytosis.

Pinocytosis is a widespread phenomenon and involves the internalization of large amounts of plasma membrane. Much of this membrane is probably returned to the plasma membrane in vesicular form, and reasons are advanced why this recycling may occur chiefly before pinosome--lysosome fusion and may be related to vacuole fusion events. Some internalized membrane must nevertheless enter the lysosomal compartment and, in order to maintain a steady state, must be removed at the same rates as it enters. This constant lysosomal involution probably occurs by the budding of vesicles either inward (for digestion) or outward (for return to the plasma membrane). The former process allows for the transfer of cytosol components into the lysosome. Quantitative studies on pinocytosis have shown that selective substrate capture is commonly achieved by the adsorption of substances to the plasma membrane being internalized. In contrast the basal rate of uptake of liquid and membrane is not easily modified. If similar considerations apply to uptake by the quasi-pinocytic lysosomal involution, modification of proteins leading to adsorption to the cytoplasmic face of the lysosome could be the rate-determining step in the degradation of endogenous cytoplasmic proteins by lysosomes.


A possible role for neutral proteolysis in the degradation of intracellular proteins.

A neutral proteinase has been solubilized from rat intestinal muscle by extraction at low ionic strength. It has an apparent mol. wt. of 33,000 and is stable only around neutral pH. Characterization studies with specific inhibitors and substrates have shown it to be a trypsin-like serine proteinase. The rat proteinase and bovine pancreatic trypsin have equivalent activities as measured with peptide and denatured protein substrates but the rat proteinase is about 300 times more active than an equimolar amount of trypsin towards proteins in their native conformation. It has been shown that the activity of the rat proteinase can be modulated (1) by changing the conformation of the substrate protein(s) and (2) by means of an endogenous inhibitor. The inhibitor has been purified to homogeneity from rat intestinal muscle. It has a mol. wt. of 8,000 and binds only weakly to the rat proteinase (Ki approximately equal to 10(-6) M). It did not inhibit any of the other proteinases tested. The implications for such a proteinase--inhibitor system in the non-lysosomal pathway of intracellular protein degradation are considered.


Studies of the ATP dependence of protein degradation in cells and cell extracts.

Experiments with metabolic inhibitors in vivo indicate that intracellular protein degradation requires the continuous production of ATP. We have established soluble cell-free preparations from rabbit reticulocytes, rat liver, and Escherichia coli that degrade abnormal protein in an ATP-dependent fashion. These enzymes appear to be responsible for the selective breakdown of abnormal protein that may result from mutations, biosynthetic errors or intracellular denaturation. Experiments with inhibitors indicate that this process and the degradation of many short-lived normal proteins does not occur in the lysosome. The cell-free extracts prepared from these crude extracts hydrolyse [14C] globin by a process stimulated 2--3-fold by ATP and to a lesser extent by GTP, CTP or UTP. These activities degrade globin to large peptides which are then cleaved by soluble peptidases. The ATP-stimulated protease that partially purified from rat liver cytoplasm is also stimulated by pyrophosphate. This protease has an apparent molecular weight of 480,000. In contrast, the E. coli enzyme has an apparent molecular weight of 115,000 and is completely dependent on ATP, after partial purification by ion exchange and gel chromatography. This enzyme can be distinguished from six other proteolytic enzymes from E. coli active at pH 7.8. E. coli contains, in addition, four proteases that are not stimulated by ATP and degrade globin to acid-soluble material. We have also demonstrated in E. coli and reticulocytes other proteases that appear specific for small protein substrates and may play a role in the later steps in protein breakdown. The ATP-stimulated endoproteases appear to catalyse the rate-limiting steps in intracellular protein breakdown. However, the actual role of ATP in the degradative process is not known.


Coordination of protein synthesis and degradation.

The degree of coordination between protein synthesis and protein degradation in developing and mature cels is considered. Studies on specific enzyme and general protein turnover in developing liver and differentiating mammary gland are presented. In the mature liver mitochondrion average protein degradation rates are higher for outer membrane and intermembrane space proteins than for matrix and inner membrane proteins. Significant heterogeneity of protein degradation rates was observed only in the outer mitochondrial membrane. During postnatal development the rates of degradation of proteins in many liver cellular fractions are increased. In the mitochondrion only the average rates of degradation of proteins in the outer membrane and intermembrane space fractions increase during development. Evidence for hormonally regulated changes in both protein synthesis and degradation during mammary cell differentiation is given. The data indicate that a transitory decrease in protein degradation accompanies the increase in protein synthesis on hormonal stimulation of the tissue. The results from the two model systems are collated and used to formulate a phenomenological hypothesis of protein degradation and its integration with protein synthesis in steady-state and non-steady-state conditions.


Application of liver perfusion as an in vitro model in studies of intracellular protein degradation.

Amino acids appear to be prime regulators of autophagy and proteolysis in liver. They both attain a maximum rapidly when livers from fed rats are perfused in the single-pass mode without amino acids and are suppressed to basal levels by amino acid additions. The fact that their greatest responsiveness to amino acids occurs slightly below normal plasma levels suggests that these cellular processes could play a role in regulating plasma amino acid concentrations in vivo. Autophagy and proteolysis are also inhibited by insulin and stimulated by glucagon. In the latter instance the hormonal action is not direct but mediated indirectly by depletion of intracellular glutamine, probably as a consequence of enhanced gluconeogenesis. Close correlations among (1) rates of intracellular proteolysis, (2) the aggregate volume of lysosomal elements, and (3) estimates of degradable protein internalized within lysosomes indicate that lysosomal function can explain total intracellular protein degradation (with the possible exception of rapidly turning over fractions) over the full range of proteolysis from maximum down to and including the basal state. Since ratios of degradable intralysosomal protein to corresponding rates of proteolysis in intact liver are constant over this range, protein internalization may be the rate-limiting step in lysosomal proteolysis.


Protein degradation and the regulation of protein balance in muscle.

The rate of of protein degradation in muscle changes in many states but the nature of these changes is often paradoxical. Thus there can be increases during growth (anabolic increases) as well as during wasting (catabolic increases). Decreases can occur during growth (anabolic decreases) as well as during wasting (catabolic decreases). These changes are observed in man (as judged by changes in 3-methylhistidine excretion) and in experimental animals. The nature of the changes is not understood but it is possible that muscle growth induces increased degradation as part of the accompanying myofibre remodelling. The rate of protein degradation can also be influenced by thyroid status, since in thyroid deficiency degradation is reduced and can be stimulated by triiodothyronine. This response is independent of changes in muscle growth. Finally, acute exercise suppresses protein degradation in vivo in man as well as suppressing protein synthesis (in vivo in rats). When protein degradation rates change, acid proteinase activities also change in muscle. The anabolic increase in degradation appears to involve increases in mainly cathepsin D whereas catabolic increases in degradation are associated with an increase mainly in pepstatin-insensitive acid autolytic activity.


Protein degradation in metabolic and nutritional disorders.

The increased protein degradation associated with diabetes appears to be different in many respects from protein catabolism in normal, well-nourished cells. In all normal eukaryotic cells examined, degradation of cytosolic proteins exhibits several striking features. Large proteins tend to be degraded more rapidly than small proteins, acidic proteins tend to be degraded more rapidly than neutral or basic proteins, and glycoproteins are degraded more rapidly than non-glycoproteins. Furthermore, a general correlation exists between protein half-life in vivo and susceptibility to proteolytic attack in vitro. In streptozotocin-diabetic rats the relationships between degradative rate and protein size, net charge, and carbohydrate content are absent or markedly reduced among cytosolic proteins of the liver. However, the correlation between protein half-life and susceptibility to proteinase in vitro is unaltered. Therefore, the enhanced protein degradation in diabetes shows little or no selectivity towards large, acidic, glycoproteins but does show specificity for proteins than tend to be sensitive to proteinases. Similar studies using other tissues from diabetic rats are reported and general characteristics of the enhanced liver protein catabolism in starvation and hyperthyroidism are briefly discussed. The biochemical reasons for the increased protein catabolism in diabetes are unclear although several possible explanations are presented. The enhanced breakdown is probably not due to cellular proteins becoming more proteinase sensitive in diabetes since experiments with a variety of endoproteinases including pronase, chymotrypsin, pepsin, and lysosomal cathepsins have failed to demonstrate more rapid digestion of liver proteins from diabetic animals.


Proteinase inhibitors in severe inflammatory processes (septic shock and experimental endotoxaemia): biochemical, pathophysiological and therapeutic aspects.

Plasma levels of antithrombin III, alpha 2-macroglobulin and inter-alpha-trypsin inhibitor, as well as those of various clotting, complement and other plasma factors, were significantly decreased in 18 patients suffering from hyperdynamic septic shock. A similar statistically significant reduction of the concentrations of several plasma factors (prothrombin and antithrombin III, plasminogen and alpha 2-plasmin inhibitor, complement factor C3 and clotting factor XIII) was observed in experimental endotoxaemia. In this model the reduction in the plasma levels of these factors was considerably diminished by the intravenous injection of a granulocytic elastase--cathepsin G inhibitor of lower molecular weight from soybeans. The results of both studies indicate that consumption of plasma factors in the course of Gram-negative sepsis proceeds not only via the classical routes (by activation of the clotting, fibrinolytic and complement cascades by system-specific proteinases such as thrombokinase or the plasminogen activator) but also to an appreciable degree of unspecific degradation of plasma factors by neutral proteinases such as elastase and cathepsin G. The endotoxin-induced release of both sorts of proteinases, the system-specific ones and the unspecific lysosomal proteinases from leucocytes and other cells, is likely to be mainly responsible for the consumption of antithrombin III and alpha-2-macroglobulin via complex formation (followed by elimination of the complexes) and the increased turnover of the inter-alpha-trypsin inhibitor as observed in the clinical study. The therapeutic use of an exogenous elastase--cathepsin G inhibitor in the experimental model was stimulated by the observation that human mucous secretions contain and acid-stable inhibitor of the neutral granulocytic proteinases, called HUSI-I or antileucoproteinase. This inhibitor protects mucous membranes and soluble proteins against proteolytic attack by leucocytic proteinases released in the course of a local inflammatory response. Preliminary results indicate that HUSI-I, which is produced by the epithelial cells of mucous membranes, does not belong to any known structural type of acid-stable proteinase inhibitor. The search for other candidates suitable for medication in humans led to the discovery of a potent elastase--cathepsin G inhibitor, called eglin, in the leech Hirudo medicinalis. This acid-stable inhibitor with a molecular weight close to 8100 has an unusual structural property in that the structure of the molecule is not stabilized by any disulphide bridge.


Cathepsin D: the lysosomal aspartic proteinase.

Cathepsin D was originally known simply as 'cathepsin' and was first purified in the late 1930s. Nowadays the enzyme is purified by conventional column chromatography, and by isoelectric focusing (which resolves isoforms), but affinity chromatography with pepstatin--Sepharose is also important. Cathepsin D is a glycoprotein of about 42,000 molecular weight; sometimes it comprises a single polypeptide chain but often this is found to have been 'nicked' about two-thirds of the way from one end. Cathepsin D is an 'aspartic proteinase' and may be one of the more primitive members of the family. The activity of cathepsin D is expressed exclusively at acidic pH values and the specificity shows a strong preference for cleavage near hydrophobic amino acids. Specific inhibition of cathepsin D with antibodies and pepstatin has provided strong evidence that the enzyme plays a part in intralysosomal proteolysis but there is as yet little evidence for extracellular activity.


Neutral proteinases of leucocytes and the inflammatory process.

Plasminogen, the inactive precursor of plasmin, a general trypsin-like proteinase, is present at high concentration in blood and in body fluids. Most cells can recruit this proteolytic potential by secreting plasminogen activator (PA) to generate localized proteolysis in the surrounding microenvironment. PA and plasmin are serine enzymes whose pH optima match extracellular pH; further, in view of the large amount of circulating proenzyme and the broad substrate range of plasmin, the possibility that this proteolytic system can initiate a variety of proteolytic reactions or sequences should be kept in mind. PA production is precisely regulated by hormones, temporal programming, or both; and enzyme synthesis is correlated with some physiological and pathological processes requiring proteolysis. Thus PA production is coordinately regulated with ovulation, trophoblast implantation, spermatogenesis, polypeptide hormone synthesis, and some developmental phenomena; and with inflammation, tumour promotion, and neoplasia. Tissue remodelling and cell migration are common to many of these processes. Macrophage (monocyte) and polymorphonuclear leucocyte PA production is modulated by many biologically active substances. Enzyme synthesis is induced and stimulated by stimuli that recruit these cells to sites of inflammation, and it is repressed by anti-inflammatory agents, notably by glucocorticoids.


Human leucocyte elastase and cathepsin G: structural and functional characteristics.

Two of the major enzymes present in an released from neutrophil granulocytes are the endoproteinases elastase and cathepsin G. While the former is believed to be one of the major causative agents responsible for tissue destruction in emphysema and rheumatoid arthritis, little is known about the function of cathepsin G. We have recently developed simple procedures for isolating the isoenzymes of each type of proteinase as well as for their specific controlling plasma inhibitors. We have also prepared synthetic substrates and inhibitor analogues. Some sequence studies have been initiated and the results indicate homology of these enzymes not only with each other and with the pancreatic proteinases but also between cathepsin G and proteolytic enzymes present in muscle and mast cell tissue. Significantly, both types of enzyme can degrade the structural protein myosin, as well as elastin and proteoglycan. However, their relative importance in muscle protein turnover or muscle disease has not yet been clarified.


Escherichia coli and group B streptococcal infections in experimental animals.

Small doses of Escherichia coli endotoxin or of viable E. coli caused only a mild illness in pregnant mice but severely impaired fetal development. After intravenous injection and after experimental renal infection E. coli multiplied in placental tissue, causing resorption of the conceptuses and sometimes fetal infection. It is suggested that in humans coliform bacteraemia sometimes results in abortion and premature delivery because of the placental damage brought about by E. coli and its abortifacient endotoxin. Isolates of group B streptococci from various sites in 175 patients varied markedly in their pathogenicity for mice, and pregnant animals were less susceptible to infection than non-pregnant. In late pregnancy streptococci multiplied rapidly in placental tissue, suggesting that the placenta may be a significant focus of infection at the time of delivery. After antibiotic treatment the majority of mice infected with a highly pathogenic strain died but the majority of those infected with a strain of low pathogenicity survived. Preliminary experiments suggest that guinea-pigs and rabbits may be useful for studying the role of maternally derived antibodies in protecting the neonate against group B streptococci.


The secretory IgA system in the neonatal period.

It is still not known when the secretory IgA response, important for defence of the mucous membranes, becomes fully competent in the human infant. The infant is, however, provided with 0.25--0.5 g of secretory IgA/day via the maternal milk. The milk contains secretory IgA antibodies against a wide variety of antigens from microorganisms, including bacteria, viruses and parasites. Many of the antibodies are directed against important virulence factors such as bacterial pili, enterotoxins, capsular polysaccharides and endotoxic lipopolysaccharides. The passive transfer of antibodies through the milk may explain why breast-fed infants are resistant to enteric infections in particular. The antibodies in the milk are often directed against antigens in the mother's milieu and intestine. An entero-mammary gland link, possibly consisting of lymphoid cells homing from the Peyer's patches in the intestine to the mammary gland, has been suggested. A limited selective uptake of oligomeric IgA from serum in exocrine glands, including the mammary glands, has also been indicated. Whichever the mechanism, the antibodies transferred via breast milk are composed to meet the needs of the infant.


Perinatal implications of the lower genital tract flora.

In a longitudinal study of the microflora of the lower genital tract at three stages in pregnancy and once postnatally, 20 different groups or genera of microorganisms were isolated. No substantial change was demonstrated in the flora as pregnancy progressed, although there was a fall in the rate of isolation of organisms after delivery. Few infants acquired organisms from their mother's lower genital tract. Caucasian mothers colonized by genital ureaplasmas gave birth to infants with a higher mean birth weight for length of gestation than the infants of ureaplasma-negative mothers. There was no correlation between birth weight and maternal genital colonization with ureaplasmas in the infants of Asian mothers. Group B streptococci were recovered from the ano-rectum more frequently than from the posterior vaginal fornix during pregnancy and strains recovered from these sites in individual patients were indistinguishable by serotyping and phage typing, suggesting that the ano-rectum or bowel is the probable source of the organism. Group B streptococci were never recovered from Asian patients (16% of the study population). Sera of women colonized with group B streptococci and cord sera from their infants had higher levels of type-specific IgG antibody than non-colonized controls and their neonates.


Neonatal group B streptococcal infection.

Group B streptococcus is now recognized as a major cause of serious neonatal infection. Between January 1973 and July 1979 35 infants with 'early onset' group B streptococcal infection were admitted to the Special Nursery, Aberdeen Maternity Hospital. Ten infants died, nine of whom were of low birth weight. Current research is directed towards defining 'high risk' groups and establishing an effective means of prevention. The concept of early administration of antibiotics to 'high risk' infants, particularly those of low birth weight, is recommended. While there is already evidence in support of the effectiveness of such an antibiotic policy, the nature of protective immunity and the place of immunoprophylaxis have yet to be clarified. Analysis of our data suggests that vaginal carriage of group B streptococcus is not associated with the mother's blood group but there appears to be an increased incidence of neonatal group B streptococcal infection in infants of mothers of blood group B.


Mutagenicity of cross-links and monoadducts of furocoumarins (psoralen and angelicin) induced by 360-nm radiation in excision-repair-defective and radiation-insensitive strains of Saccharomyces cerevisiae.

The furocoumarin psoralen can form both monoadducts and cross-links with DNA when combined with 360-nm radiation, whereas the analog angelicin can form monoadducts only. Psoralen plus 360-nm radiation causes mutation induction with a slope of 2 (log-log plot) for a radiation-insensitive strain, whereas angelicin action with 360-nm radiation displays a slope of unity. For a radiation-sensitive mutant defective in the excision-repair pathway, the actions of both angelicin and psoralen plus 360-nm radiation exhibit one-target kinetics, but at higher exposures psoralen plus 360-nm radiation assumes a slope of 2. The excision-repair-defective strain is considerably more sensitive to the furocoumarins plus 360-nm radiation than is the radiation-insensitive strain, both for killing and mutation induction. The simplest explanation for the data is that both cross-links and monoadducts, formed by furocoumarins with DNA when exposed to 360-nm radiation, are capable of inducing mutations, and that monoadducts are repaired 20 times more efficiently than cross-links by the excision-repair pathway.


Effect of the co-carcinogen benzo[e]pyrene on microsome-mediated chemical mutagenesis in Salmonella typhimurium.

Chemical agents that possess the ability to alter tumorigenicity of carcinogens (administered at subthreshold dose) constitute a major health hazard. We have employed the Ames Salmonella assay to examine the effect of co-carcinogenic benzo[e]pyrene (B[e]P) on microsome-mediated chemical mutagenesis. B[e]P enhanced the mutagenic activity induced by 2-acetylaminofluorene (2-AAF) and benzo[a]pyrene (B[a]P) in strains TA1538 and TA98. Enhancement was also noted with N-hydroxy-2-AAF (the proximal metabolite of 2-AAF) but not with an ultimate carcinogenic form (N-acetoxy-2-AAF). These results suggest the use of this approach to detect chemical agents that possess the ability to alter the activity of mutagenic or carcinogenic chemicals.


The mutagenicity of dialkyl nitrosamines in the Salmonella plate assay.

N-nitrosodimethylamine (DMN) is not mutagenic in the standard Salmonella plate incorporation assay (Ames test) in the presence of an in vitro metabolic activation system (S-9) derived from rat liver. When the S-9 was derived from Aroclor- or phenobarbital-induced mouse or hamster liver or from uninduced hamster liver, mutagenic activity was observed. Increasing the amount of S-9 above the usual maximum level of 50 microliter per plate increased the mutagenic response. Similarly, the mutagenicity of N-nitrosodiethylamine (DEN) and N-nitrosodi(n-butyl)amine (DBN) was greater in the presence of hamster liver S-9 than when mouse or rat liver was used. Data are also presented indicating that the ability of rat liver S-9 to mediate the mutagenic activity of DMN in the "preincubation" assay is due to the fact that the various components are present in this assay at several times the concentrations attained in the standard plate incorporation assay.


Problems associated with the application of short-term tests for mutagenicity in mass-screening programs.

The application of short-term tests for toxicological evaluation of environmental chemicals is certainly a reality in the near future as a result of the Toxic Substances Control Act, as well as other regulations under development [de Serres, 1977]. Many of the problems associated with this testing in the area of genetic toxicology are under study at the National Institute of Environmental Health Sciences in our National Toxicology Program and at the Environmental Protection Agency in their Gene-Tox Program. The other problems that I have discussed in connection with standardization of protocols, protocol review and modification, and training of personnel are not being pursued aggressively. Perhaps with their definition and acceptance as meaningful problems, mechanisms will be established for their resolution. It is in these latter areas that I hope that this society can provide the forceful leadership that will result in their resolution in the near future.


Bile as a source of mutagenic metabolites produced in vivo and detected by Salmonella typhimurium.

The in vivo metabolic activation of several mutagenic compounds was assayed in the bile of rats, with Salmonella typhimurium as the indicator organism. It was determined that for some compounds, particularly the aromatic amines, a substantial percentage of the compound was excreted into the bile as either a nonmutagenic glucuronide conjugate or a mutagenic metabolite of the compound. Relatively low doses of the chemical were detected, and it was possible to follow the excretion pattern of the compounds over the collection period.


Mutagenicity detection of in vivo nitrosation of dimethylamine by nitrite.

In vivo nitrosation of dimethylamine by nitrite was measured with an intrahepatic host-mediated mutagenicity assay using Salmonella typhimurium as the detecting organism. It was possible to detect the product, N-nitrosodimethylamine, at much lower doses with this system than with previously reported in vivo systems. This and other improvements made it possible to detect the formation of nitrosodimethylamine from relatively low levels of gavaged precursors.


Mutagenic activity of epoxy embedding reagents employed in electron microscopy.

Components of epoxy-based embedding media used in electron microscopy were examined for their mutagenicity in the Ames Salmonella system. The compounds, singly and in combination, were shown to be active with strain TA100 (base substitution indicator) but not with TA98 (frameshift indicator). When tested separately the epoxy resins Araldite, Epon, and vinyl cyclohexen dioxide (VCD) and the plasticizer diglycidyl ether of propylene glycol (DER-736) were found to be significantly mutagenic. These active compounds, in combination with liver mixed oxidase preparation (S9), showed increased mutagenicity over similar preparations in the absence of microsomal activation.


Phototherapy for neonatal hyperbilirubinemia--a potential environmental health hazard to newborn infants: a review.

Phototherapy has been shown to be an effective therapy for severe neonatal jaundice. However, because of its seemingly innocuous effect on normal babies, this therapeutic modality has been widely used to prevent jaundice in circumstances where it may be neither necessary nor beneficial. The present report summarizes results which indicate that phototherapy is endowed with DNA-modifying properties and has therefore the potential for inducing genetic and carcinogenic effects. These disconcerting findings concerning the long-term hazardous consequences of an accepted therapeutic procedure require that the unique physiologic and pharmacologic characteristics of the newborn populations be recognized when assessing the risks and benefits of phototherapy.


Mutagenicity of organic extracts from Canadian drinking water in the Salmonella/mammalian-microsome assay.

Organic extracts of chlorinated Ontario drinking water samples have been found to induce mutation and lethality in the Salmonella/mammalian-microsome histadine reversion assay. Collections of water were made at water treatment plants in five municipalities in June 1978. To determine the reproducibility of the positive mutagenic effects found, a second sampling at the same plants was performed in September 1978. Preparation of extracts involved passing 200 liter samples through XAD-2 resin columns which were eluted with a mixture of hexane and acetone, and the eluent was evaporated to dryness. For those extracts with sufficient organic matter, dose-related increases in mutagenicity were observed. Extracts of untreated water from a river and a well were weakly mutagenic.


Mutagenicity of resin acids identified in pulp and paper mill effluents using the Salmonella/mammalian-microsome assay.

Ten resin acids which have been identified as constituents of pulp and paper mill effluents have been examined for potential mutagenicity in the Salmonella/mammalian-microsome assay. Only neoabietic acid has been found to be mutagenic. Neoabietic acid showed dose-related increases in mutagenicity in strains TA1535, TA100, TA1538, and TA98, but not in strain TA1537. Metabolic activation with a preparation of Aroclor 1254-induced liver homogenate (S9) slightly reduced the mutagenic responses. Negative responses were found for abietic acid, dehydroabietic acid, levopimaric acid, 7-oxodehydroabietic acid, monochlorodehydroabietic acid, dichlorodehydroabietic acid, pimaric acid, isopimaric acid, and sandaracopimaric acid.