Fracture separation of the coracoid process associated with acromioclavicular dislocation: conservative treatment--a case report and review of the literature. Complete acromioclavicular dislocation associated with fracture separation of the base of the coracoid process is uncommon. This is a report of a 51-year-old man with severe emphysema and limited physical demands in whom the acromioclavicular dislocation and coracoid process fracture were treated conservatively with sling immobilization and early motion and exercises. Good power and full, painless range of motion with minimal symptoms was observed at 6 months follow-up. The strong coracoclavicular ligaments, rather than rupture, may avulse the coracoid process near its base and with disruption of the acromioclavicular joint may allow complete dislocation of the clavicle. A satisfactory result may be obtained without operative reduction of either the acromioclavicular joint or the coracoid process.


Gram negative bone and joint infection: sixty patients treated with amikacin. Sixty patients with bone and joint infections secondary to gram negative infection were evaluated in relation to treatment with amikacin. Forty-seven of these patients had osteomyelitis, and 13 had joint infections, including 3 prosthetic replacements. The patients' average was 35 years and there was no predilection for any particular skeletal location. Only 6 patients had no associated predisposing medical problems. Of these problems fracture, diabetes and narcotic abuse were most common. Thirty patients had Psuedomonas infection, and 15 others had multiple pathogens including Pseudomonas. Aminoglycoside antibiotics had been previously used in 25. Amikacin was given for an average of 22 days with a mean dose of 13.4 mg/kg. Bone and synovial fluid levels of amikacin were in therapeutic range. At least 48 patients had concurrent local wound treatment in addition to parenteral administration of amikacin. In 47 patients enough information was available to determine the efficacy of treatment. Twenty-seven (57%) of these patients were considered cured, both clinically and for bacteriologic response; and additional 9 (19%) were considered partially cured. Amikacin is effective against susceptible pathogens in bone and joint infections and is a reasonable choice when aminoglycoside antibiotic is indicated.


Wide resection of primary tumors of bone and replacement with massive bone grafts: an improved technique for transplanting allogeneic bone grafts. The treatment by wide resection of 104 local aggressive and low grade malignant bone tumors is presented with results after follow-up for 5.0 years on the average. The series comprises 29 giant cell tumors, most of them malignant or premalignant, 25 cartilaginous tumors (12 verified chondrosarcomas and 13 chondromas suspect of malignancy), 14 cases of sarcoma, 6 of fibrosarcoma, 4 parosseal sarcomas, 3 osteosarcomas and one chordoma. The remaining 36 cases include: aneurysmal bone cysts, fibrous dysplasia, chondroblastomas, osteoblastomas, giant chondromyxoid fibroma, and hemangiomas. After resection of the affected area, the resulting defect was replaced with massive autologous or allogeneic bone or osteoarticular graft in altogether 68 cases (autologous bone transplant in 61 cases and allograft in 7). A metallic endoprosthesis was used in replacement in 8 cases. No replacement of the defect was needed in 28 cases. The technique of the allogeneic bone transplantations consisted of massive bone or bone cartilage grafts which had been stored at a low temperature, and firm osteosynthesis. In every case, allogeneic (stored) bone was supplemented with autologous cancellous bone around the juncture of graft and host bone. This supplement proved to be important for success of the operation. The overall results were good in 81% and fair in 11%. Five cases had to be amputated and 3 patients were lost to follow-up, a possible total of 8% poor results. Extensive resection with massive bone grafting is a worthwhile approach in the treatment of selected cases of aggressive and low grade malignant bone tumors.


Effects of hormones on osteocyte function and perilacunar wall structure. Microradiographical and ultrastructural aspects of periosteocytic lacunae are determined by osteocytic activity, lacunar modeling and perilacunar miniremodeling in particular. The miniremodeling activity is constituted by two alternating processes: osteolysis and osteoplasis. Modifications of lacunar shape and size and of perilacunar wall ultrastructure, caused by a direct or indirect effect of certain hormones on osteocytic activity, were observed. The lacunar modeling alterations, particularly in cases of VDH or PTH deficiency, result in an irreversible impaired calcification of the lacunar walls and consequently, mottled lacunae. The alterations of periosteocytic osteolysis are characterized by an increase in number of enlarged lacunae and/or by increased magnitude of this lacunar enlargement. Usually observed as an effect of PTH and VDH, these alterations can also be induced by GC, T4, PG. On the other hand, CT causes a decrease in periosteocytic osteolysis. Periosteocytic osteoplasis is characterized by perilacunar bone formation of various aspects and is known to be stimulated by CT. The osteocytic response to hormones is a function of concentration and not of time; it is transient and not integrative. It can be concluded that none of the perilacunar wall modifications observed is characteristic of any particular hormonal effect or metabolic bone disease.


Antibiotic penetration of synovial fluid in infected and normal knee joints. A spectrum of new and commonly used antibiotics was examined with regard to their ability to penetrate into joint fluid in normal and E. coli infected rabbit knee joints. In order to carry out this investigation a new, simple method of measuring antibiotics in very small amounts of synovial fluid was developed. Cephalothin, cefazolin, cefoxitin, carbenicillin, amikacin, and gentamicin all penetrated into synovial fluid effectively achieving peak concentrations within 30 minutes to one hour. Synovial fluid antibiotic concentrations at 2 hours were equal to or higher than simultaneous serum levels. This relationship persisted thereafter. Penetration of antibiotics into infected joints was dependent primarily on serum concentration and was not altered importantly by the presence of acute chronic or previous infection. Antibiotic doses employed were equivalent to clinical usage on a weight basis. Penetration of all antibiotics studied was satisfactory for use against their normally intended pathogens.


One stage femoral lengthening.

One stage femoral lengthening. Femoral lengthening can be obtained by a technique using a Z osteotomy and a distraction device separate from the operative field. The expected gain in length is 3-3.5 cm in children, 4-4.5 cm in adults. Sustained flexion of the knee during the procedure prevents vascular and nervous complications. One peroneal nerve and 2 femoral nerve palsies were nevertheless observed in 180 cases of the whole series. These were caused by a failure to comply with technical details. Bony union occurs promptly in young children. Pseudarthrosis occurred 11 times in patients more than 16-years-old, and once in an 8-year-old child. Avascular necrosis of the bone fragments after total separation of the soft tissue from the femoral shaft explains the frequency of non-union after the age of skeletal maturity. Faster and sound union in adolescents and adults is obtainable by the use of decortication to exposure the femur and strong internal fixation. The best indication for this method is a moderate discrepancy allowing a safe and complete equalization of limb length.


Septic arthritis associated with avascular necrosis of the femoral head. Avascular necrosis may predispose joints to a septic process particularly in the immunosuppressed individual. The clinical and radiographic presentation may not be diagnostic in the patient with pre-existing joint disease. Suspicion of infection and early aspiration of the involved joint are the keys to early diagnosis. Four patients with avascular necrosis of the femoral head, secondary to renal transplantation and corticosteroids in 3, and systemic lupus erythematosus and corticosteroids in one, presented with super-imposed joint infections. All were treated with intravenous antibiotics and frequent joint aspirations and the infection was resolved.


Eikenella corrodens in human bites.

Eikenella corrodens in human bites. Eikenella corrodens, a gram negative rod, was cultured in about one third of 24 patients with human bite wounds. The organism was sensitive to penicillin but not to methicillin. Clinically the infections in which Eikenella corrodens were found were not different from other infections. Because of the variety of possible pathogens in human bite infections, we start the patients on a broad spectrum antibiotic while awaiting the results of the culture and sensitivity. However, antibiotics alone are not sufficient treatment in HBI; 20 of 24 patients in this series required surgical drainage. Surgical treatment consists of thorough exploration, exteriorization and excision of devitalized tissues. Complications were more frequent in sutured wounds, or when surgical drainage was delayed.


Conjunctivitis in children. A refresher survey of diagnosis and contemporary treatment. The management of acute conjunctivitis need not be confusing. In the newborn period the common etiologic agents are chemical, TRIC, and bacterial. The latter two causes are effectively treated with sulfacetamide ophthalmic preparations. Dacryostenosis should be suspected in any child with recurrent conjunctivitis in the first six months of life. With older children the major causes can be classified as viral, allergic, foreign bodies, and bacterial. Bacterial conjunctivitis almost always responds to sulfacetamide ophthalmic preparations.


Prazosin in hypertension with and without methyldopa. The efficacy of prazosin was assessed in 21 patients with essential hypertension who failed to respond adequately to a combination of methyldopa and hydrochlorothiazide. The patients were divided randomly into two groups; in the first group prazosin was substituted for methyldopa and in the second group prazosin was added to the combination. In group 1, the average blood pressure (BP) fell from 144/102 mmHg (sitting) and 142/105 mmHg (standing) to 136/91 mmHg (sitting) and 129/91 mmHg (standing) after prazosin (17 mg) was substituted for methyldopa. The fall in the diastolic BP was statistically significant (p less than 0.01). In group 2, BP fell from 146/101 mmHg (sitting) and 143/103 mmHg (standing) to 126/87 mmHg (sitting) and 118/86 mmHg (standing) when prazosin 14 mg was added to methyldopa and hydrochlorothiazide. The reductions in systolic and diastolic pressures were statistically significant (p less than 0.001).


Acebutolol in supraventricular arrhythmias. The effect of intravenous acebutolol on supraventricular arrhythmias was evaluated in 20 patients, 5 with chronic obstructive pulmonary disease. A rapid ventricular rate in atrial fibrillation was slowed greater than 15% in all of 10 patients by acebutolol and in none of 5 patients by saline. A rapid ventricular rate in atrial flutter was slowed greater than 15% in all of 6 patients by acebutolol and in none of 3 patients by saline. Frequent premature atrial beats were abolished or reduced by greater than 75% in each of 2 patients by acebutolol and not in a patient by saline. Acebutolol converted multifocal atrial tachycardia to sinus rhythm in a patient. Digitalis-induced nonparoxysmal atrioventricular junctional tachycardia was not affected by saline but was abolished by acebutolol in a patient. Acebutolol was well tolerated in each of 5 patients with chronic obstructive pulmonary disease. Acebutolol is useful in the treatment of supraventricular arrhythmias.


The effects of calcium and calcium-ionophores (X 537 A and A 23187) on renin release in the isolated perfused rat kidney. 1. Calcium depletion from the medium of the isolated perfused kidney reduced renin release and renal perfusate flow. 2. Reintroduction of calcium increased renin release and perfusate flow. 3. The ionophore X 537 A (0.1-4 micromol/1) increased renin release both in the presence and absence of calcium in the medium. 4. The ionophore A 23187 (1-10 nmol/1) increased as well as decreased renin release. There was a positive correlation between direction of this effect and renal perfusate flow. 5. The results are compatible with the view that the effects of calcium and ionophores on renin release are the sum of direct and indirect effects of these agents, the predominant indirect effect being the modification of vascular tone.


Implications of prostacyclin generation for modulation of vascular tone. 1. The biotransformation of arachidonic acid and prostacyclin in the circulation was studied in anaesthetized dogs, using the blood-bathed organ technique. 2. In passage through the lungs, arachidonate (50-800 microgram kg-1 min-1) was transformed into prostacyclin. No thromboxane A2 or prostaglandin E2 could be detected in arterial blood. 3. In dogs treated with indomethacin (5 mg/kg), intravenous infusions of arachidonate had no cardiovascular effects and no prostacyclin was produced. Therefore, the vasodilator effects of arachidonate in vivo may be attributable to prostacyclin formation. 4. Prostacyclin, unlike prostaglandin E2, is not inactivated by passage across the lungs, and only about 50% disappears in one passage through peripheral vascular beds. 5. Thus prostacyclin released from the lungs could function as a circulating vasodilator and contribute to the regulation of blood vessel tone and blood pressure.


The role of prostaglandins in the pathogenesis of hypertension. 1. Biosynthesis of PGE2 from [14C]arachidonic acid has been found to be lower and PGF2alpha higher in the renal medulla of spontaneously hypertensive (SH) rats than in normal Wistar (NW) rats. 2. Biosynthesis of prostacyclin (PGF1alpha) from [14C]arachidonic acid was decreased in lungs, aorta and heart of SH rats. 3. Metabolism of [3H]PGF1alpha was decreased in renal cortex and lungs and PGE2 increased in SH rats in comparison with NW rats. Thus the lungs of SH rats let more PGF and less PGE enter the systemic circulation. 4. Emotional stress decreased the metabolism of [3H]PGF1alpha in lungs of SH and NW rats, the effect being less in SH rats.


Interpretive reporting of laboratory data. Gastric analysis. The reporting of gastric analysis data requires clearly formatted and documented analytic results, accurately calculated secretory rates, appropriate normal values based on age, sex and weight of the patient, and interpretive review of the data based on well-documented personal experience or comprehensive studies reported in the medical literature. We report here a technique using inexpensive and flexible data processing equipment suitable to most community hospital laboratories.


A computer program for estimation of reference percentile values in laboratory data. It has been suggested that the physician would be aided in his interpretation of clinical laboratory results if the data were reported in terms of percentile ranking in a reference population as well as in conventional units. This paper describes a FORTRAN porgram for estimating the necessary reference percentile values by means of regression over 20% of the distribution rather than by interpolation between adjacent points. The regression estimates are shown to have a negligible bias and to be somewhat more stable than those obtained by interpolation.


Evaluating the performance of a computer-based consultant. The performance of a computer-based clinical consultation system is evaluated. The program, called MYCIN, is designed to function as an aid for infectious disease diagnosis and therapy selection, with an initial emphasis on bacteremias. The evaluation methodology is discussed, as well as the difficulties encountered in attempting to evaluate clinical judgments. Specialists in infectious diseases judged MYCIN's final therapy recommedation, and intermediate conclusions about the significance of the infection and identity of infecting organisms. The evaluation techniques described may be useful in assessing the performance of other clinical decision aids. Results of the evaluation show that the program's therapy recommedations meet Stanford experts' standards of acceptable practice 90.9% of the time (table 2), with some variation noted both among individual experts and between Stanford experts and others (tables 1, 2).


Texturized proteins: fabrication, flavoring, and nutrition. This paper provides a comprehensive review of the current methods used for the texurization of proteins, with emphasis on soy proteins. The sensory characteristics, i.e., flavor, texture, and color are discussed, particularly in relation to the problems of simulating meat flavored products. The nutritional qualities of texturized products are reviewed, and current regulations concerning their use in foods are cited.


Colorimetry--methodology and applications. Color and appearance, those nebulous aspects of food acceptability which are taken for granted by most consumers, are coming under increasingly severe scrutiny. For this reason, it is essential that an adequate knowledge base for measurement be available to those working in the field. This base must be grounded upon the fact that color is a sensory phenomenon, and its measurement must include the physical, psychological, and physiological aspects. That is, measurement must involve tristimulus colorimetry, whether obtained by spectrophotometric or colorimetric techniques. It is the object of this article to review the general area of tristimulus colorimetry along with the techniques required for measurement. It is essential to include a section on the manipulation of data as well, since colorimetric data is often misused. Further treatment will be given to object-light interactions and how these affect not only measurement but sample perception, since manipulation of the physical parameters of the sample can affect the total appearance and color. Instruments and their usage will be reviewed so that decisions may be made on the correct instrument for a particular measuring system. In addition, a section will be devoted to on-line color measurement which may facilitate continuous processes. A final section of this article will deal with some advances in data manipulation and the development of new scales for color measurement. Fundamental colorimetric theory is essential in this area for proper usage. It is the aim of this paper to integrate theory with application in order to facilitate optimization of both the color of food and its measurement.


The psychophysical relationships between color and flavor. Psychophysics has become a well-defined discipline in science and is undergoing a period of transition from the theoretical and academic to the applied. Certainly the use of magnitude estimation in flavor evaluation is becoming more accepted, and concurrently the food research area is utilizing the colorimetric techniques which are available. However, there has been virtually no investigation carried out on the quantitative relationships which exist between color and flavor in a psychophysical sense. Intuitively, many researchers state the qualitative effect of color on flavor, but the quantification of these techniques is practically nonexistent. This paper will attempt to summarize the psychophysical techniques which are available for such studies, as well as discuss the importance of these studies. Great controversy exists concerning the need for colorants in food. If color does indeed affect flavor quantitatively, it will affect intake and, therefore, final nutritional status of the public in a quantitative manner. This controversy should be resolved in the light of fact, not intuition.


Culture conflict and coping in a group of aboriginal adolescents. Critical incidents adapted to presentation in picture form were used to investigate responses of Aboriginal adolescents from Elcho Island mission in the Northern Territory of Australia in conflict situations arising from culture contact. These Aboriginal youths are part of a complex environment where choice behaviour is mediated by specific and broader situational characteristics of the social environment. Results showed a relationship between conflict responses and orientation to traditional values and skills, but no apparent relationship between conflict responses and modern value orientation or psychopathology variables. Adolescents who attended high school in Darwin were seen as more mission and academically oriented than locally educated youth. Contary to expected patterns, males appeared to be less involved in both mission and traditional activities and more restricted by traditional social expectations than were females.


[Amikacin and gentamicin: a controlled comparison (author's transl)]. In a randomised double-blind study 25 patients each were treated with amikacin (375 mg/d three times i.m.) or gentamicin (three times 80 mg/d i.m.). The dose was decreased according to a predetermined schedule if there was impaired renal function. Treatment indication was urinary tract infections of different severity with gram-negative organisms resistant to penicillin and cephalosporin. The bacteriological findings of a urine sample obtained by bladder puncture three and ten days after the end of treatment were the criterion of success. In addition, the number of white cells in the urine was taken into account. On the basis of various criteria, amikacin was found to give the higher success rate. The most important criterion, disappearance of the initially demonstrated microorganism, demonstrated a statistically significant advantage of amikacin over gentamicin.


[Rubella immunity: immunofluorescence test as a rapid and reliable alternative to the haemagglutination inhibition test (author's transl)]. Nowadays the haemagglutination inhibition test (HIT) is used almost exclusively in the assessment of rubella immunity. But this test has a few weaknesses. Indirect immunofluorescence test (IFT), on the other hand, has had little attention paid to it. The author performed parallel tests on 1621 sera. Of 1339 HIT- positive sera 1299 (97%) were also also positive in the immunofluorescence test, which takes two hours. The IFT in many situations proved to be superior to the HIT. It is recommended as an alternative to HIT, both in the assessment of rubella immunity and in checking HIT results.


[Angiopathy in a case of primary oxalosis combined with familial spherocytosis (author's transl)]. An 18-year-old female with primary oxalosis, seen first when she was in advanced renal failure, developed a severe necrotizing angiopathy which began after a rapid decrease in renal function requiring chronic dialysis. Because of the severe angiopathy the preliminary diagnosis of an acute autoimmune vasculitis had been made. The correct diagnosis was revealed by renal biopsy and a renal transplantation performed. Soon after severe oxalosis led to failure of the renal transplant and death. The patient had also had familial spherocytosis, inherited from her father, while the oxalosis had been inherited from her mother. It is suggested that early transplantation at the onset of renal failure, as long as the blood oxalate level is still tolerably low, may give better results than have so far been reported.


[Asa foetida in the treatment of the irritable colon: a double-blind trial (author's transl)]. In a double-blind trial of two groups of 50 patients each with irritable colon (of whom 91 could be evaluated) asa foetida was found to be effective at the 1% significance level.


[Some parameters in reproduction of a Maroccain sheep breed (race d'Man) (author's transl)]. The importance of the sheep in Marocco was shown with help of statistical data. As there exist very few scientific work on sheep reproduction in this country, we began to work on local breeds with the race d'Man. The breed is asaisonal and is able to lamb 2 times within 13 months, with mostly 2 or more youngs (1,8 lambs per partum). The delay of gestation was found with 150 days, the duration of a cycle 17 days. The libido shown by the rams is violent. They easily accepted an other male as phantome for the collection of sperm with the easily accepted artificial vagina. The gonads are ovoid formed and are early developed. Remarkable is the tail of the epididymis which is covered in a pocketlike formed structure of the distal scrotum. Its volume is remarkable. Concerning the characteristics of the sperm there is no difference with other breeds. Therefore the conclusion seems reasonable that this apparent development of the epididmymis tail is an organ for thermoregulation for the sperm as the breeds origin are the oasis of the Sahara. The early onset of puberty as well as the violent sexual interest and the high rate of reproduction and asaisonal behavior could be a reference to a "primitive breed".


Vasodilators in myocardial infarction: rationale and current status. While digitalis and diuretics constitute conventional therapy of congestive heart failure due to acute myocardial infarction, systemic vasodilator drugs offer an innovative approach of decreasing left ventricular systolic wall tension (afterload) by reducing aortic impedance and/or by reducing cardic venous return. Thus, vasodilators increase lowered cardiac output by diminishing peripheral vascular resistance and/or decreasing increased left ventricular end-diastolic pressure (ventricular preload) by reducing venous tone. Concomitantly, there is a reduction of myocardial oxygen demand thereby potentially limiting infarct size and ischaemia. The vasodilators produce disparate modifications of cardiac function depending on their differing alterations of preload versus impedance: nitrates principally cause venodilatation (decrease left ventricular end-diastolic pressure); sodium nitroprusside, phentolamine and prazosin produced relatively balanced arterial and venous dilatation (decrease left ventricular end-diastolic pressure while increasing cardiac output, provided upper limits of normal left ventricular end-diastolic pressure are maintained); and hydrallazine solely effects arteriolar dilatation (increases cardiac output). Combined sodium nitroprusside and dopamine therapy synergistically enhances cardiac output and decreases left ventricular end diastolic pressure. In addition, sodium nitroprusside is aided by mechanical counterpulsation which sustains myocardial perfusion pressure in acute myocardial infarction.


Potential toxicity of materials used for home insulation. The two aqueous solutions used for production of residential home insulation by the so-called urea-formaldehyde process were tested for their ability to react with cellular macromolecules. One of the components (the catalyst-surfactant) changed the apparent molecular weight of isolated DNA and increased its rate of attachment to bacterial and animal cells. The other component (the formaldehyde-urea resin) showed both these activities, especially following its exposure to mouse or rat liver extracts (postmitochondrial supernatants). Actively growing HeLa cells exposed to the catalyst-surfactant solution and then extracted with phenol yielded diminishing amounts of DNA, suggesting the formation of strong bonds to other cellular macromolecules, most likely to proteins. Formation of complexes between nucleic acids and proteins, enhanced cellular binding of DNA, and decreased extractability of DNA from growing cells exposed to chemicals have been found in separate studies to correlate with carcinogenic activity of various substances. Since a significant number of buildings will be insulated with this urea-formaldehyde foam and since such foam is also used in agriculture on crops, appropriate precautions should be taken to limit human exposure to the component materials.


[The corrosion behavior of the bonded alloy Ultratek]. Ultratek crystal has a multiphasic structure; beryllium is concentrated in one phase. Under the influence of the solvent, this phase is attacked and the Be salts are released. Measurement of atom absorption revealed that the amount of beryllium actually released is extremely low. Under the influence of reagents present in the buccal cavity or which come in contact with it, the amount of beryllium is 10(4) times lower (per 1 cm2 free surface metal per day) than the maximal values permitted according to the calculation of an earlier MAC value (maximal concentration for working conditions).


[Materials for fusing ceramics, their properties and behavior]. Tests of bending strength carried out on rods of metal alloys and ceramic material as well as on rods of bound metal ceramic material provided information concerning the properties of the basic materials. The influence of the 0.2% limit and the E-modulus of metal alloys on the strength of the bound constructions is only ascertainable in a few cases. This is attributed to the considerable influence of the binding strength of the metal ceramic material on the strength of the whole construction.


[Comparison between 2 elution methods for biological testing of materials]. The possibility of separating the eluate and the actual biologic test for determining tissue tolerance was studied using two cements containing copper and two cements without copper. Both the materials and the two eluates obtained according to the different procedures were tested immediately. Distilled water was added to one sample of the material, and the mixture was placed in an autoclave for one hour. A second sample was leached in nutrient solution for 24 hours at 37 C. Uniform results were obtained with the copper-free material. Results with the material containing copper however varied; the results of the eluate obtained after one hour in the autoclave were different from the results obtained after 24 hours in the nutrient solution or after direct testing. The test results for the last two procedures were similar. Comparison of the two elution methods indicates that extraction in physiologic nutrient solution is better than the autoclave method using distilled water.


[Coating of metal implants with the bioactive glass ceramics Ceravital]. The bioactive glass ceramic Ceravital forms a physicochemical bonding with bone which is capable of withstanding stress caused by tension. This glass ceramic may already be put to clinical use as replacement for minor osseous parts. However, physical data are limited for maximum stress withstanding or gracile whole ceramic implants. In this study, metal cylinders from an alloy of CoCrMo are initially coated with a bio-compatible adhesive layer of enamel, approximately 0,2 to 0,3 mm thick. The adhesive strength of this kind of enamel amounts to about 120 to 140 kp/cm2. After the enamelling process, the glass ceramic is pressed into the enamel in granules at a particle size of 100 to 200 micrometer. As the first results show, this new process is suitable for the combination of metal implant stability and tissue compatibility of glass ceramic.


[Animal experimental studies on the regeneration of controlled bone lesions in varying cooling preceedures]. Various controlled defects were inflicted under cooled conditions in the femur and humerus of sheep. Radiologic, histologic, and fluorescence microscopic examinations showed that an internally cooled fraise was advantageous. The positive effects, particularly in deeper areas of bone, were determined via quantitative analysis.


Consecutive gas chromatographic determination of phenytoin, phenobarbital, primidone, phenylethylmalondiamide, carbamazepine, trimethadione, dimethadione, ethosuximide, and valproate from the same serum specimen. A quantitative gas-liquid chromatographic procedure is described for the consecutive determination of phenytoin, phenobarbital, primidone, phenylethylmalondiamide, carbamazepine, trimethadione, dimethadione, ethosuximide and valproate from a single serum specimen of 1.2 ml. After extraction from serum by two different procedures, the anticonvulsants are chromatographed without further purification on a 3% OV 17 column either with or without derivative formation by means of "on-column" methylation. Multiple internal standards are employed in order to enhance the reproducibility of drug-concentration measurement.


Antibiotic susceptibility of the peptidyl transferase locus of bovine mitochondrial ribosomes. We have a used a modified 'fragment reaction' to compare the susceptibility of isolated bovine mitochondrial ribosomes, bacterial (Escherichia coli) ribosomes and eukaryotic (bovine microsomal) ribosomes to several antibiotics. All of these ribosomes share certain structural features of their peptidyl transferase center, as indicated by their interaction with substrates, puromycin and gougerotin. Bovine mitochondrial ribosomes have other structural features in common with bacterial, but not cytoplasmic ribosomes, as revealed by their susceptibility to chloramphenicol and the streptogramin antibiotics. While mitochondrial ribosomes are susceptible to all inhibitors of bacterial ribosomes tested, their low susceptibility to the lincosamines and macrolides suggests that some component(s) of the binding sites for these antibiotics is altered.


The effects of tiamulin, a semisynthetic pleuromutilin derivative, on bacterial polypeptide chain initiation. Tiamulin, a water-soluble and highly effective semisynthetic derivative of pleuromutilin leads to the formation of physiologically inactive polypeptide chain initiation complexes which readily decompose and do not enter the phase of peptide chain elongation. Once elongation has begun it continues even in the presence of tiamulin as has been shown by measuring the formation of N-acetylphenylalanine-poly(phenylalanine). The formation of abortive initiation complexes was observed regardless of whether AcPhe-tRNA of fMet-tRNA was used as an initiator or whether artificial messengers or a natural messenger, like R17 bacteriophage RNA, was used. When this drug was acting on whole cells, it led to the disappearance of polysomes. The only structures which could be detected were of the monosome size. Therefore, polysomes seem to elongate the polypeptide chains in whole cells in the presence of this antibiotic, but since effective reinitiation is blocked, the polysome pool of the cell soon becomes depleted.


Biodegradative threonine dehydratase. Reduction of ferricyanide by an intermediate of the enzyme-catalyzed reaction. The threonine-dependent reduction of ferricyanide catalyzed by the purified biodegradative threonine dehydratase of Escherichia coli has been studied. The rate of production of 2-oxobutyrate in the presence of ferricyanide was lower than that found in the absence of ferricyanide. The concentrations of threonine required for half-maximal effects for the reduction of ferricyanide and, in the presence of the dye, for 2-oxobutyrate production, were 3 mM and 9mM, respectively. Reduction of ferricyanide was accompanied by evolution of CO2, and even within a very short incubation time with the enzyme, the ratio of ferricyanide reduced over CO2 evolved was approximately 7. Stopping the enzyme activity after a brief exposure to threonine at pH 9.7 resulted in the accumulation of an intermediate (with a half-life of 4 min at 25 degrees C) which formed an adduct with N-ethylmaleimide; the accumulated intermediate, in the absence of N-ethylmaleimide, reduced ferricyanide with concomitant evolution of CO2. We conclude from these results that 2-aminocrotonate is the intermediate which serves as a source of reducing equivalent for ferricyanide, and nonstoichiometric amount of ferricyanide reduction may be attributed to some secondary reactions of ferricyanide with compounds derived from the oxidation product of 2-aminocrotonate.


The mechanism of substrate activation of pyruvate decarboxylase: a first approach. The sigmoidal shape of the curve for v[S], characteristic of pyruvate decarboxylase, indicates that the catalytic activity of this enzyme is regulated by the substrate. The enzyme, which is inactive in the absence of its substrate, is activated not only by 2-oxo acids but also by 2-oxo acid amides, which cannot act as a substrate of the enzyme. Whilst the dissociation constant of the enzyme-activator complex depends on the electrophilic nature of the carbonyl group, the catalytic activity reached at saturation concentrations of the activator species is independent of the structure of the activator molecules. The mechanism of activation which proceeds via two reversible steps could be evaluated exactly by stopped-flow techniques. The kinetic parameters of the activation and deactivation reaction were estimated and the validity of the equations derived which describe the activation kinetics could be proved by comparing them with the measured data. Using glyoxylic acid as an irreversibly binding active-site marker, it could be shown that addition of the substrate to the enzyme-bound thiamin diphosphate is the step of the catalytic mechanism whose rate is controlled by the substrate (activator) molecule.


Identification of cysteine-10 of protein S18 as part of the mRNA-binding site of Escherichia coli ribosomes by affinity-labeling studies with a chemically reactive A-U-G analog. The reaction of a bromoacetamidophenyl derivative of the initiation codon A-U-G (A-U-G) with tight couples of Escherichia coli ribosomes leads to an exclusive crosslinking of label to protein S18. This crosslinking inhibits A-U-G-directed fMet-tRNAfMet binding into the puromycin-sensitive site of ribosomes and stimulates elongation-factor-dependent binding of Met-tRNAmMet. It is, therefore, concluded that protein S18 is located at or near the aminoacyl-tRNA binding site of E. coli ribosomes. Peptide as well as amino acid analysis shows that the reaction between A-U-G and ribosomes took place at cysteine-10 of protein S18. A-U-G could not be crosslinked to ribosomal proteins of the temperature-sensitive E. coli strain 258ts, where arginine-11 of protein S18 is replaced by a cysteine residue.


Gastric secretory function in coeliac disease. Volume, total titrable acidity, total proteolytic activity and pepsin activity have been determined in 14 coeliac patients and in 8 controls of comparable ages and body weights. Basal secretion (B.O.), total outputs (T. O.) and peak outputs (P.O.) after pentagastrin injection have been determined. Peak outputs (values 60 min/kg) of these parameters are as follows: volume 5.0+/-1.7 ml in coeliacs, 4.3+/-1.2 ml in controls; total titrable acidity 406.1+/-155.0 mEq in patients, 296.1+/-182.4 in conttrols; total proteolytic activity 962.1+/-501.1 micronEq in coeliacs, 569.6+/-272.2 in controls; pepsin activity 789.1+/-521.8 micronEq in patients, 447.6+/-150.4 in controls.


Once daily propranolol in the treatment of mild to moderate hypertension: a dose range finding study. Propranolol was administered in a single dose of 80 mg, 120 mg, 160 mg, 240 mg, or 320 mg, to 23 patients with essential mild to moderate hypertension in a randomised, double-blind cross-over study. All treatments produced a significant fall in lying and standing blood pressures compared with placebo, but there was no statistically significant difference in the effects of the different doses. The percentage of patients showing a satisfactory fall in blood pressure was not different in the five treatment groups. The major anti-hypertensive effect of each dose was present by two weeks. The frequency of side-effects were similar on all the doses.


Effect of the mucoregulator S-carboxy-methyl-cysteine in patients with chronic bronchitis. Twenty patients with stable chronic bronchitis entered a double-blind study in which changes in clinical and respiratory function and biochemical and rheological variations were examined after treatment with the mucoregulator S-carboxy-methyl-cysteine (S.C.M.C.). After one week of single-blind placebo, a two week double-blind study was initiated with placebo or oral S.C.M.C. 3 g/24h. After two weeks, a significant clinical improvement was observed in patients treated with S.C.M.C. During treatment, there was no change in respiratory function, although a drop in FEV1/VC was noted in the placebo group. A significant increase in the viscosity of the expectorations was observed after treatment with S.C.M.C. for two weeks. The levels of secretory IgA and of serum albumin in the expectorations remained stable, whereas in the placebo group, there was a slight but significant increase in serum albumin. In this group of non-infected chronic bronchitic patients, S.C.M.C. appeared to normalize the secretory function of the bronchial mucosa by preventing inflammation and enhancing the viscoelastic properties of bronchial secretions.


Clinical response and plasma concentration of amitriptyline and its metabolite nortriptyline. Plasma levels of amitriptyline and nortriptyline were measured twice weekly in 62 patients treated for three weeks with i.m. amitriptyline 120 mg/day. In half the patients the ratio of amitriptyline to nortriptyline was under 1 and in the other half it was greater than 1. 30 of these 62 patients were clinically monitored with the Hamilton Rating Scale and the side effects of the drug were recorded. There was no correlation between plasma level of the drug and its side effects, but there was a statistically significant curvilinear correlation between the plasma levels of amitriptyline plus nortriptyline and nortriptyline alone, and the clinical effect. The practical value of this type of investigation was demonstrated by showing that patients whose drug plasma level was not in the therapeutic range, were clinically improved after adjustment of the dose. The plasma level of amitriptyline plus nortriptyline must lie between 60 to 220 ng/ml, and that of nortriptyline between 60 to 140 ng/ml, to obtain the best clinical effect. Associated treatments, age, weight and sex of patients, and the type of depression did not appear significantly to affect the plasma level of the drug.


Effect of labetalol on plasma noradrenaline and adrenaline in hypertensive man. Injection i.v. of labetalol, a new adrenergic alpha- and beta-blocking agent, decreased arterial blood pressure in 9 hypertensive subjects resting in the supine position, when standing and during supine exercise. Heart rate after labetalol was unchanged in the resting supine position, and it fell in the latter two conditions. Plasma noradrenaline concentration was higher after labetalol in all three experiments as compared to a control study. Plasma adrenaline after labetalol was increased only in the standing position, when the highest plasma noradrenaline concentrations were observed. Blood glucose concentration tended to increase after labetalol, but the difference was not statistically significant. The changes in plasma noradrenaline and blood glucose after labetalol mimic findings observed after alpha-adrenergic receptor blockade. The beta-adrenergic receptor blocking property of labetalol is responsible for the reduced heart rate and it is likely to contribute to the higher plasma noradrenaline concentration observed when standing and during supine exercise.


Pharmacokinetics of ordinary and sustained-release lithium carbonate in manic patients after acute dosage. An ordinary and a sustained-release lithium carbonate preparation were administered acutely at equivalent dosage (1.80 g = 24.3 mmol) in a crossover fashion to manic patients. Serum lithium levels were determined by atomic absorption spectroscopy and pharmacokinetic parameters were calculated. Maximum mean serum levels of 1.13 mmol/l and 0.78 mmol/l were achieved at 6 h and 12 h respectively with the ordinary and sustained-release forms. The mean half-lives of absorption, redistribution and elimination were 0.78 h +/- 0.05 (SE), 5.06 h +/- 0.23, 26.8 h +/- 4.5 and 3.73 h +/- 0.37 (SE), 4.42 h +/- 0.28 and 25.6 h +/- 5.5 for the ordinary and sustained-release forms respectively. In healthy volunteers the ordinary preparation was completely absorbed but only 85% of the sustained-release form was absorbed in the manic subjects. Lithium ion distributed into two kinetic compartments and the final compartment appeared to correspond to total body water.


Plasma concentration of diazepam and N-desmethyldiazepam in children after a single rectal or intramuscular dose of diazepam. The absorption of diazepam and N-desmethyldiazepam after administration of diazepam solution for parenteral injection per rectum and intramuscularly was studied in 9 children (ages 3--12 years). Rectal administration of diazepam 1 mg/kg led to rapid absorption with plasma levels of 270--320 ng/ml within 5 min, and peak levels of 600--1300 ng/ml 10--60 min after administration. The absorption was comparable to that after intramuscular administration. A second peak in plasma diazepam concentration 6--12 h after dosing was observed in 6 children, which may have been due to mobilization of diazepam from the gastrointestinal mucosa produced by feeding 4 h after administration of the drug. A slowly increasing plasma level of N-desmethyldiazepam was observed during the first 24 h after administration of diazepam.


Labetalol, a cross-over double blind controlled trial. 20 patients (12 female) with moderately severe essential hypertension [blood pressure during placebo treatment 181 +/- 6 (systolic), 107 +/- 3 (diastolic)] completed a double-blind, cross-over dose-titrated comparison of labetalol and methyldopa. Both drugs reduced lying and standing arterial blood pressure to a similar extent, although only labetalol reduced heart rate. Compliance was high (greater than 95%) with both drugs, and the incidence of subjective adverse effects was similar.


Timolol and bendrofluazide in the management of hypertension in general practice. The beta-adrenergic blocking drug, timolol, was combined with bendrofluazide in a comparative trial between once and twice daily dosage, conducted on 51 patients suffering from hypertension seen in general practice. During the initial control period seven of these patients became normotensive, leaving 44 who entered the trial. Using a crossover design, treatment was continued for a total period of up to 16 weeks. With both dose regimes, systolic and diastolic pressures were rendered normotensive in over three-quarters of the patients, significant reductions occurring within the first two to four weeks of treatment.


Recognition of idiotypes in lymphocyte interactions. II. Antigen-independent cooperation between T and B lymphocytes that possess similar and complementary idiotypes. Antigen-independent cooperation between T and B lymphocytes is demonstrated in vitro in two different experimental protocols: (a) B cells from A/J mice immunized in vivo either with Group A streptococcal vaccine (Strep A) or with the IgG1 fraction of guinea pig anti-idiotypic antibody to the A5A idiotype, mature into plaque-forming cells (PFC) with specificity for Group A streptococcal carbohydrate (A-CHO) during a 4-day culture together with T cells from A/J mice immunized in vivo with A5A idiotypic antibody. (b) B cells from A/J mice immunized in vivo with Strep.A generate PFC specific for A-CHO when cultured in the presence of small concentrations of anti-A5A idiotypic antibody and of T cells primed with Strep.A. In both cases, antigen-independent cooperation is idiotypically selective, such that only those B cells respond that secrete antibody with the A5A idiotype. The data are interpreted to suggest that, in addition to antigen-specific helper cells, idiotype-specific may participate in antibody responses, and that the latter type of help may be responsible for the idiotypic selectivity in T-B cooperation observed previously. Furthermore, idiotype-specific cooperation may be a means to generate and maintain B cell diversity during the evolution and ontogeny of the immune system.


Cell-mediated immunity to myelin basic protein in Lewis rats made unresponsive to experimental allergic encephalomyelitis. Lewis rats with experimental allergic encephalomyelitis (EAE) exhibited cell-mediated immunity to myelin basic protein as determined both with in vivo and in vitro assays. Positive skin test reactions and production of migration inhibitory factor (MIF) were observed before onset and after recovery from EAE. Rats rendered unresponsive to EAE exhibited in vitro cell-mediated immunity to basic protein, although in vivo manifestations were depressed. However, tolerant rats failed to respond to the encephalitogenic determinant; rats with EAE exhibited cell-mediated immunity to this region of the molecule. The results indicate that EAE-unresponsive rats possess lymphocytes capable of responding to basic protein, but that reactivity to the encephalitogenic peptide is suppressed.


Effects of ionophores A23187 and X537A on vascular smooth muscle activity. The ionophore A23187 initiated contractions in both dog coronary artery and rabbit aortic strips in a dose-dependent manner whereas X537A contracted rabbit aortic strips and relaxed KCl-induced contractions in dog coronary artery. Diphenylhydantoin (DPH) and verapamil ccompletely abolished KCl-induced responses in both vascular tissues. DPH (10(-4) M) partially prevented A23187-induced responses in both tissues and verapamil (33 micrometer) partially prevented A23187-induced responses in dog coronary artery but not in rabbit aorta. Phenoxybenzamine (10(-5) M), but not practolol, significantly reduced X537A-induced contractions in rabbit aortic strips but did not affect A23187-induced contractions in either tissue. The inability of DPH and verapamil to completely block the A23187 contractions leads one to conclude that these agents do not completely block calcium influx, or that A23187 does not work solely by increasing the permeability of the cell membrane to calcium. The effect of X537A on rabbit aorta, however, may be mediated at least partially, via release of catecholamines.


A stereotaxic method based on ventricular radiography in the cat (with special reference to the stereotaxic topography of the substantia nigra). A method based on an intracerebral coordinate system and contrast ventriculography was developed for stereotaxic surgery in the cat. The intercommissural (CA-CP) line was used as the principal reference because its length showed little variability in animals within a wide weight range. The stereotaxic coordinates of the substantia nigra (SN) in relation to the CA-CP line and the midline were evaluated in serail sections. Stereotaxic operations with the use of ventricular radiography were performed in different parts of the SN in 18 cats. Histological verification showed that the selected target regions within the SN were very accurately reached in all animals operated with this method. The precision of the stereotaxic method based on the intracerebral coordinate system compared to the Horsley-clarke method is discussed.


The chick embryo choriallantoic membrane as a bioassay for angiogenesis factors: reactions induced by carrier materials. A variety of filter materials, sponges, and gels were placed on the chick chorioallantoic membrane (CAM), the reactions of it investigated and compared with those induced by natural egg materials (white eggshell membrane, coagulated albumen and yolk). Independently of the kind and nature of the naterials the CAM reacted nearly regularly underneath these diverse materials with a proliferation of ectodermal cells, fibroblasts, and blood vessels forming a highly capillarized granulation tissue. The area of the CAM surrounding the foreign materials frequently displayed an increase of small blood vessels macroscopically discernible and showing a radial arrangement (spoke-wheel-appearance according to FOLKMAN 1974). It is concluded that this type of vascular reaction cannot be considered as a characteristic feature for the action of a special tumour angiogenesis factor, since it can be induced by a variety of stimuli leading to an inflammatory reaction in the CAM. For the detection of special angiogenetic activities an objective quantification of the vessel reactions is necessary under consideration of the reactions induced by the mere presence of such foreign materials.


Determination of the numerical density of spherical and ellipsoidal particles in the adrenal zona glomerulosa, based on distribution measurements. I. Methods. Two methods are described to determine the numerical density of spherical and ellipsoidal particles. Both methods are based on the estimation of distribution of corpuscles. The distribution of spherical elements was determined by an approximate form of the Schwartz-Saltykov method for obtaining the average tangent diameter of particles, and in consequence of measurability limits practical modifications were introduced. The equation published by WEIBEL and GOMEZ (1962) was the basic relationship of the numerical density calculation of elliposidal corpuscles. The required distribution and shape coefficient of this equation was estimated from the size and shape distribution of particles. Statistical independence was assumed between the size and shape, and consequently the two distributions can be estimated separately. To determine the size distribution the Schwartz-Saltykov method, and for determination of the shape distribution the Wicksell's method was used. The mathematical bases of measurements and calcualtions are presented in this paper.


Morphology of lymphoreticular tissues in mice with reticulosarcoma. The response of murine lymphoreticular tissues to transplantation of a syngenic reticulosarcoma with mild transplantation antigenicity was studied by recording weight changes and histology. The results were compared with those obtained in normal mice and mice challenged with syngenic spleen cells. The tumor induced vigorous histological response in regional lymph nodes and mild response in nonregional lymph nodes and spleen. Mesenteric lymph nodes and thymus did not respond to the tumor. Observed morphological and gravimetrical changes indicated that both regional and nonregional lymph nodes and spleen take part in host immune response to tumor. A possible contamination of tumor tissue by viruses has been excluded.


Anti-myosin stains chromaffin cells.

Anti-myosin stains chromaffin cells. The presence in fixed chromaffin cells of antigenic sites for a myosin antibody was demonstrated using immunofluorescence techniques. Tests on viable cells showed that at least some of the antigenic sites seem to be localized on or close to the cell surface and explained the cell agglutination that occurred with the addition of the myosin antibody to cells isolated by a method described in this paper.


Role of intracellular calcium in promoting muscle damage: a strategy for controlling the dystrophic condition. It is suggested that various muscle diseases and examples of experimentally-induced muscle damage arise because of a high calcium level in the myoplasm. When [Ca2+]i is raised experimentally in amphibian or mammaliam muscle by treatment with A23187 or caffeine, myofilament degradation follows quickly. Such a rapid action suggests the involvement of a sequence of proteolytic activity that is stimulated by a rise in [Ca2+]i. Ca2+ might either trigger protease activity directly or indirectly, or promote the release of lysosomal enzymes. A high [Ca2+]i in dystrophic muscle is believed to be the resultant of a sequence of events that is summarized in the figure. Suggestions are presented for different ways in which the steady-state position of [Ca2+]i might ultimately be controlled for the clinical amelioration of some dystrophic conditions.


Induction of deoxyribonucleic acid degradation in Escherichia coli by ozone. Cell survival and deoxyribonucleic acid (DNA) degradation wave measured for wild-type Escherichia coli B251 cells after exposure to different concentrations of ozone. The results show that extensive breakdown of DNA occurs after ozonation and that the extent of ozone-induced DNA degradation generally correlates with the colony-forming ability of the cells.


Clinical fever: its history, manifestations and pathogenesis. A short summary of some aspects of the history of clinical fever is presented with special reference to its association with inflammation. The role of bacterial endotoxins and endogenous pyrogen (released from inflammatory cells) in the genesis of human fevers is reviewed. Clinical diseases are tabulated within various broad categories and discussed in relation to the frequency with which they are associated with fever and the probable pathogenetic mechanisms involved. Certain unresolved discrepancies are emphasized in the light of our present knowledge.


The present state of development of cancer chemotherapy. Cancer chemotherapy has evolved through 3 decades of remarkable progress. At the present time over 40 drugs and biologicals are employed in the treatment of cancer, and hundreds of promising compounds and analogs await their turn in the clinic. The medical management of cancer patients with chemotherapy has developed into a recognized subspecialty--medical oncology, a discipline that now works closely and effectively with surgery and radiotherapy in planning treatment strategies. Major areas of progress to date include the concept of combination chemotherapy, the development of hematologic and microbiologic supportive care, and the demonstration of effective adjuvant chemotherapy. Further progress is anticipated in a number of areas: rational selection of anticancer compounds based on metabolic or kinetic vulnerability; increased attention to biologic substances that modify neoplastic cell behavior; continued refinement of doses and schedules of active compounds to optimize therapeutic benefit and minimize toxicity; awareness of novel methods of drug delivery; and development of physical or chemical modifications to enhance drug effects.


Gonadotropin and testosterone secretion in normal human males after stimulation with gonadotropin-releasing hormone (GnRH) or potent GnRH analogs using different modes of application. Gonadotropin-releasing hormone (GnRH) and some potent long-acting GnRH analogs, applied by different routes of administration, were tested in six healthy human males. The effects on gonadotropin secretion were compared with the one after intravenous (i.v.) bolus injection of 25 microgram of GnRH. The net increase of luteinizing hormone (deltaLH) in serum produced by 25 microgram of GnRH i.v. was matched by subcutaneous (s.c.) injection of 100 microgram of GnRH, dissolved in 20% gelatin or without gelatin; 5 microgram of D-Ser (TBU)6-des-Gly10-GnRH-ethylamide i.v.; 5 microgram of D-Leu6-des-Gly10-GnRH-ethylamide i.v.; and 50 microgram of D-Trp6-des Gly10-GnRH-ethylamide given pernasally (p.n.). D-Leu6-des-Gly10-GnRH-ethylamide, 50 microgram p.n., produced one-half such increase as did also multiple p.n. administrations of 200 microgram of GnRH every 2 hours. With 100 microgram of GnRH and all analogs, elevation of serum LH lasted for about 7 to 9 hours. The longest elevation was observed with GnRH dissolved in gelatin and with D-Ser (TBU)6-des-Gly10-GnRH-ethylamide, as reflected by the greatest areas under the curves of net increase. The longer the duration of the action of LH secretion, the higher was the observed increase in follicle-stimulating hormone (FSH). Correlation between effect on LH secretion and testosterone secretion was not found. By infusion of 1 microgram/kg/hour od D-Leu6-des-Gly10-GnRH-Ethylamide in two men over a period of 15 hours, a plateau of gonadotropin levels was reached within 7 to 9 hours. These plateau levels, especially of FSH, were higher than after bolus injection or p.n. application.


["Entero-insular axis" and regulation of blood sugar and insulin levels following oral glucose loading]. The mineral water Essentuki 17 administered per so with glucose exerted a modifying effect on the regulation of glycaemia and insulinaemia in intact rats. This effect undergoes a few phases of changing and disappears by the 30th day. Under conditions of this adaptation, the glycaemia regulation is somewhat worsening. After i.v. administration of glucose during this period the regulation of glycaemia and insulinaemia remains unaltered. This suggests that the mineral water exerts its biological effect, mainly, on the entero-insular axis system (Unger and Eisentraut, 1969) and that the modifying effect is due not to a concrete complex of the mineral water electrolytes but rather to the unspecific factor of "perturbation" in the enteral medium.


Evidence for the presence of non-muscle actin in LW13K2 rat neoplastic cells. It was demonstrated that I-bands in cultured cardiac muscle cells and non-interrupted fibrils in smooth muscle cells, irrespective of phenotypic state and number of subculture, stained with an antibody directed against native actin from chicken gizzard smooth muscle, but that non-muscle cells in the same cultures did not stain. Neoplastic rat LW13K2 cells, whether confluent or subconfluent, did not stain with the same muscle-actin antibody. This is by no means evidence of a non-muscle origin of LW13K2 cells. However, it does show that these cells express in culture an actin which is not the same as that in muscle cells, and consequently that it can be used as a source of non-muscle actin.


Detection of binding areas on removable partial denture frameworks. Owing to a multiplicity of errors introduced during impression procedures and fabrication, disclosure of binding areas on the metal framework is an essential part of any removable partial denture service. Disclosure is best accomplished with an indicator that provides a sensitive, thin, even, and opaque coating. The aims of adjustment or relief are to maintain forces along the long axis of abutment teeth and ensure passivity, and in so doing create a more favorable prognosis. Careful consideration and thought must precede any reduction. Experience should contribute greatly in determining the indicated reduction and the accuracy of performing it.


Overdenture oversights.

Overdenture oversights. Overdenture oversights can occur in the following areas: patient selection, hard and soft tissue preparation, laboratory procedures, or post-placement maintenance. If the dentist takes steps to control these factors, overdenture therapy can be an enjoyable and satisfying part of his service to his patients. Certainly the measures outlined in this article require minimal effort, and should be included routinely in treatment.


Prevention of failures in making impressions and dies. I have attempted to provide information that will help to prevent failures that occur during partial denture construction as a result of unsatisfactory fabrication of crowns. Methods of exposure of the preparation margins, provision of adequate bulk of the elastic impression material, proper selection of die construction, and the removable die technique were discussed.


Considerations in fixed prosthodontics.

Considerations in fixed prosthodontics. More than any other treatment procedure, the success of removable partial denture prosthodontics depends upon planning and coordination of treatment. It is essential that both the patient and the dentist understand and agree upon the approach to be taken. Fixed prosthodontic restorations are often the foundation upon which the removable partial denture is constructed, and their contribution to the overall success cannot be minimized.


Treatment planning and design: prevention of errors of omission and commission. It has been emphasized how fully removable partial prosthodontics can and should affect the mouth in a program of preventive dentistry. Indeed, a partial denture can have greater effect than any other single restoration. Additionally, among the many aspects and procedures in treatment planning and design, are a number of very familiar but often neglected ones. Hopefully the reader will seriously ask himself if he is routinely including them in his planning and execution.


Preventing ceramic failures when integrating fixed and removable prostheses. The successful integration of fixed and removable units requires diagnostic skill, careful planning, and adherence to detail in execution. Failures can be either in function or esthetics, may occur in either the fixed or removable segment, and can be catastrophic or insidious. Success demands that all the customary requirements for each independent unit, fixed or removable, be met and then the additional requirements for integration be ascertained and fulfilled. In such situations there are an exponentially greater number of possibilities for failure. When the dentist is alert to the potential for failure he may intercept and prevent it. Meticulous care pays long-term dividends in the lasting satisfaction of a patient who enjoys imporved masticatory performance, preservation of the existing tissues, and self-confidence borne from a smile that does not reveal differences between the natural and the simulation of nature. The integration of fixed and removable units is another manifestation of the skillful blending of science and art.


Esthetic factors in removable partial prosthodontics. For the patient, the appearance of the finished restoration is of paramount importance. To avoid an esthetic failure, the dentist should pay attention to those various components of removable partial dentures which play a role in esthetics.


I-bar: myth and countermyth.

I-bar: myth and countermyth. An attempt has been made to stress the importance of removable partial denture design totality and to clarify the relationship of other major components to I-bar retainer usage. As outlined in this article, I-bar retainer usage is only one part of a given, comprehensive design philosophy. Its successful use has been shown to be as much based on proper application as upon appropriate, defensible design. There is no realistic concept of a simple I-bar partial denture just as there has never been one "technique" that serves as a panacea for all treatment situations.


Stressbreakers: a practical approach.

Stressbreakers: a practical approach. The use of stressbreakers for removable partial dentures will doubtless continue to be controversial. Most of the data available for guidance are clinical trials and observations. It is not reasonable to expect a 100 per cent success rate for any biomechanical device. All available designs should be considered in order to choose the right treatment for the situation. When indicated and correctly executed, the 12-gauge chrome wire and the split palate stressbreakers have proved to be practical adjuncts to our treatment armamentarium.


Dentist and laboratory: a "love-hate" relationship. The author's intent has been to promote a close working relationship between the dentist and the technician. Certainly, McCracken was doing that when he said that he hoped they could "work together in proper sequence to develop restorations that are biologically and mechanically sound and to produce removable partial dentures that reflect continuous progress in prosthetic dentistry". That's the secret. The dentist and the technician should work together and in proper sequence. Too often dental education and the dental profession have seemed to espouse the idea that the technician must function as an automaton in the fabrication of removable partial dentures. The practitioner of general dentistry can certainly ask for ideas and suggestions from the technician and still control the ultimate outcome. The dentist can share thoughts with the technician to ameliorate the "love-hate" relationship and still be responsible for the removable partial denture treatment.


Structure of LiCl core particles of 50 S ribosomal subunits from Escherichia coli by electron microscopy. The structure of 50 S E. coli ribosomal subunits was studied by electron microscopy as these particles were gradually depleted of proteins by incubation with 0.5 to 6.0 m LiCl. Changes observed in the structure of the depleted subunits were correlated with the location of the deleted ribosomal proteins on the control 50 S particle. These changes were particularly striking in the "crown" region, the site of a considerable number of the proteins necessary for the biological activity of the 50 S subunit. Protein L 16, the first to be removed by the LiCl treatment, was found to be essential for the structural integrity of the large subunit through interactions with ribosomal proteins residing in the left-hand side crest and the interface. Based on electron microscopic evidence, a scheme was proposed for the structural changes accompanying the stepwise unfolding of the 50 S E. coli subunit by LiCl.


Pituitary-testicular axis in diabetic men with and without sexual impotence. In nine impotent diabetics (ID), eight diabetics with normal sexual function (ND), eight impotent non diabetics (IN) and seven normal patients (NN), we found normal basal FSH and LH levels. Plasma testosterone (T) values were significantly lower in ID and IN in comparison with NN and ND. After LHRH injection, plasma T increased in ID up to normal values. In non diabetic patients (NN and IN), LHRH induced a slight but significant rise in blood glucose. Post LHRH gonadotropins response was in the normal range for all groups and the amplitude of the response was highly correlated with basal levels except for LH in ND. Mean blood glucose during the test and LH response to LHRH were not inversely correlated in the patients studied. We conclude that impotence in diabetic patients is a neurological complication and that low testosterone levels are probably secondary to a decreased coital frequency. ID and IN probably share a common pattern of inadequate hypothalamic feedback control in the presence of low testosterone levels.


Glucagon secretion in rats bearing a growth hormone producing tumor (MtT-W-15). The release of glucagon from pancreatic and extrapancreatic sources was studied in normal rats and in rats carrying transplants of a MtT-W-15 tumor which secretes large quantities of growth hormone and prolactin. The tumor-bearing rats had high serum levels of A cell immunoreactive glucagon (IRGa), total immunoreactive glucagon (IRGT) and immunoreactive insulin (IRI) and an increased total glucagon and insulin content of the pancreas. Pancreatic islets isolated from tumor-bearing rats secreted more glucagon under basal conditions but did not respond significantly to low glucose stimulation. However, they contained more insulin per islet and secreted more insulin under basal and stimulated conditions. The serum IRGa response to arginine infusion in vivo was lower in the tumor-bearing than in the normal rats. The introduction of a 5% glucose solution into the small intestine caused similar increases in the level of serum IRGT in the two groups of rats. Thus, the tumor increased the total pancreatic glucagon content and basal secretion, blunted the A cell response to stimulation, but did not significantly alter the secretion of glucagon by the intestine. We attribute these responses to tumor-induced hypersomatotropinism although we cannot rule out an effect of the large amounts of circulating prolactin.


Simultaneous determination of insulin secretion and glucose oxidation rates during incubation of isolated rat islets of Langerhans. Insulin secretion being related to glucose metabolism of the B cell, it seemed of interest to develop a suitable system to measure these two parameters on the same islet pool, in order to overcome the great individual differences observed when these are measured in separate experiments. For this reason, we used an incubation system allowing the measurement of insulin secretion concomitantly with the determination of the corresponding oxidation rate. The results obtained agree well with those described by several authors using separate experimental procedures. Thus, our experimental design appears to be a reliable method for simultaneous determination of insulin secretion and glucose oxidation rates.


Dissociation of the porcine anterior pituitary: the kinetics of luteinizing hormone release in response to luteinizing hormone-releasing hormone. A method has been developed for disaggregating porcine anterior pituitary tissue and for providing dissociated preparations which have good, stable viability in culture. The secretory capacity for these preparations in terms of their ability to release luteinizing hormone in response to luteinizing hormone-releasing hormone has been documented in detail. In following the short-term kinetics of LH secretion a biphasic pattern of release has been demonstrated in which a sharp initial peak, maximal at 2 min, is followed by a second, more prolonged phase of release reaching a maximum between 10 and 20 min.


Effects of calcium, lanthanum, and bicarbonate ion on epinephrine modification of insulin release in vitro. The role of calcium flux in mediating epinephrine modification of insulin release was investigated by using lanthanum, an inhibitor of calcium flux, in the in vitro perifusion system. Lanthanum inhibits insulin secretion stimulated by glucose and by acetylcholine to basal levels. Epinephrine and lanthanum have additive effects in inhibiting insulin secretion to glucose stimulation. The effect of epinephrine prestimulation on insulin secretion to subsequent glucose challenge varies markedly, depending on the presence or absence of bicarbonate ion: epinephrine priming is reversed in the absence of bicarbonate, and effect possibly related to reduced calcium uptake. In the presence of bicarbonate, lanthanum blocks the priming effect of epinephrine on insulin secretion. The data further support the postulated role of calcium in adrenergic effects on beta cell function.


Regranulation of islets of Langerhans and normalization of in vivo insulin secretion in ob/ob mice treated with oxytetracycline. Oxytetracycline (OTC) treatment was associated with regranulation of the islet cells and increased pancreatic insulin content in the ob/ob mouse. This was accompanied by an improvement of the in vivo insulin secretory response to glucose. Because of the wide-ranging effects of OTC on other membrane-related functions, it is postulated that this compound may exert ist effect by altering the composition of cellular membranes.


Insulin and glucagon secretion by islets isolated from fetal and neonatal rats. Islets were isolated by mild collagenase digestion and microdissection from rat fetuses 2 days before term and pups 1 or 2 days after birth and their insulin and glucagon secretion studied in vitro. Fetal B cells were stimulated by 16.7 mmol/l glucose, 20 mmol/l leucine or 20 mmol/l arginine. Fetal A cells were not affected by glucose or leucine, but were significantly stimulated by arginine. Somatostatin abolished the effect or arginine on both IRI and IRG output. Neonatal islets proportionally released more insulin and glucagon than their fetal counterparts, but reacted to the tested agents in a similar fashion. During the perinatal period, pancreatic insulin storage increased at a higher rate than that of glucagon. It is concluded that fetal B cells are equipped with sensors to a variety of agents and able to modulate their secretory rate according to the concentration of these agents. A cells are reactive to arginine 2 days before term but do not become glucose reactive until several days after birth.


Preservation of beta cell function in adult human pancreatic islets for several months in vitro. Islets of Langerhans were isolated from four human kidney donors, aged 16 to 21 years by the collagenase method described for isolation of rodent islets. So far the human islets have been kept in tissue culture, without attachment, in medium RPMI 1640 supplemented with 10% calf serum for more than 9 months, with preservation of the ability to release insulin in response to glucose stimulation. Replacement of calf serum with serum from normal human subjects did not affect B-cell survival, but resulted in elevated insulin values partly due to lower insulin degrading activity. Thus the described technique presents a valuable tool for studying chronic effects of metabolites and hormones on islet function, as well as for islet storage prior to transplantation into humans.


Inhomogeneity of surface labelling of B-cells at prospective sites of exocytosis. Using ferritin-labelled Ricinus communis agglutinin to detect lectin-binding sites of the pancreatic B-cell surface, we show that limited regions of the plasma membrane are deprived of lectin-binding sites over marginated secretory granules. Such deprived regions increased during glucose stimulation of B-cells in monolayer culture: 56 +/- 8 of them were found in high (300 mg/100 ml) glucose as compared to only 27 +/- 5 in low (50 mg/100 ml) glucose (p less than 0.005). In addition, non-membrane, intracytoplasmic bridges were detected between the plasma membrane and the membrane of the marginated granule suggesting the involvement of cell web components in promoting the change in surface labelling.


Rat gastric secretion studies with synthetic gastrin-like tetrapeptide. Gastric acid and pepsin secretions were measured in the perfusing rat stomach preparation with sodium-citrate-phosphate buffer, pH 6.6. In anesthetized rat stomach preparation, acid output in both basal and stimulated conditions seemed to be small, but pepsin output was observed even in a short period. In the rats which were fed freely just before use, basal pepsin output was significantly lower than that of fasted rats, although in the basal acid output and in the acid and pepsin output during stimulation in both groups, there was no difference statistically. Intravenous infusion of tetragastrin (1, 2, 4, 8, 16 and 32 microgram/kg/hr) produced a dose dependent acid and pepsin secretions. Tetragastrin, at the dose of 8 microgram/kg/hr, stimulated acid and pepsin output. Acid output was kept constant for three hours, but pepsin output was made to peak within an hour and formed a plateau after 1.5 hours at a level of 30% of peak pepsin output.


Immunofluorescence studies of apolipoprotein B in intestinal mucosa. Absence in abetalipoproteinemia. During fat absorption, active synthesis of cholesterol, phospholipids, and specific apolipoproteins are required for chylomicron formation and secretion. In the inherited disease abetalipoproteinema, chylomicrons cannot be made in response to fat feeding, and they as well as low and very low density lipoproteins are completely absent from plasma. The genetic defect in the disease is presumed to be an inability to synthesize apolipoprotein B, the apoprotein common to all the above lipoprotein classes, but such a defect has not been directly demonstrated. With peroral intestinal biopsies and immunofluorescence and intracellular localization of apolipoprotein B within jejunal epithelial cells of five normal subjects and have shown that its content increases markedly after fat feeding. In two patients with abetalipoproteinemia no apolipoprotein B was seen by immunofluorescence techniques in the jejunal mucosa in the fasting state or after a fatty meal. Intestinal synthesis of apolipoprotein B appears not to occur in abetalipoproteinemia.


Treatment of duodenal ulcer with antacid and sulpiride. A double-blind controlled study. The effect of aluminum-magnesium hydroxide tablets (800 mg seven times per day) and that of sulpiride, a hypothalamic neurolaptic, were studied in 101 patients with duodenal ulcer in a double-blind controlled 4-wk trial. Significantly more of the patients treated with antacid, sulpiride, or antacid-sulpiride combination showed a greater than 50% reduction in ulcer size than did the patients treated with placebo. However, only in the antacid- and antacid-sulpiride-treated groups did the ulcer, with and without residual inflammation, disappear statistically more often than in the placebo-treated group. Furthermore, only in the antacid-sulpiride-treated group did complete healing, with no trace of inflammation, occur statistically more often than in the placebo-treated group. Disappearance of ulcer pain was likewise statistically more frequent in the antacid-sulpiride group than in the placebo-treated group. Antacid therapy with aluminum-magnesium hydroxide tablets appears to accelerate the rate of ulcer healing. Sulpiride appears to have a minor but definite synergism with antacids. Cigarette smoking affected ulcer healing adversely; on the other hand, factors favorable to healing were the early onset age of ulcer symptoms and acid hypersecretion. Male patients also healed more favorably than females.


[Herpes genitalis and herpes neonatorum (author's transl)]. This review discusses some basic virologic as well as epidemiologic aspects of herpes genitalis and herpes neonatorum. The clinical picture of herpes neonatorum is presented. At the moment, from the point of view of survival and of psycho-motoric development, the prognosis of this neonatal infection is poor. This fact, as well as the inability of therapeutic trials to modify the prognostic outlook, derive from the hitherto published experiences. Up to this time, the literature also fails to prove the validity of prophylactic cesarean section in preventing neonatal herpes simplex infection. Based on theoretical grounds, however, this prophylactic intervention seems still to be justified under specific circumstances. Repeated cervical smears toward the end of pregnancy are recommended: virologic cultures, whose results can often be communicated after 24 hours, are helpful in deciding if cesarean section is to be performed.


[Measurement of LH in urine by HI-gonavis test for the predetermination of ovulation (author's transl)]. The immunological LH/HCG test HI-Gonavis was used to measure the LH-excretion in urine of 30 patients during 1 to 3 cycles. The level of LH in plasma was determined simultaneously by radioimmunoassay. 12,5IU LH/L urine, the limit of sensitivity of HI-Gonavis, coincide with 7,2 mIU/ml plasma. 50 or 100 IU LH/L urine were found in patients showing a LH plasma level which was higher than 12,5 mIU/ml. In the ovulatory cycle this value is reached 1 day before the LH-peak. From the correlation of the preovulatory increase of LH in the plasma and the LH-excretion in the urine it can be concluded, that the detection of 50 IU LH/L urine indicates the ovulation within the next 12--30 hours. The practicability of this test for the predetermination of ovulation is demonstrated by examples.


Ultraviolet-induced reversion of cyc1 alleles in radiation sensitive strains of yeast. II. rev2 mutant strains. The range of specificity of the rev2-1 mutation, an allele that reduces the frequency of ochre revertants induced by UV in Saccharomyces cerevisiae (LEMONTT 1971a), has been investigated by examining its influence on the reversion of eleven well-defined and contrasting cyc1 mutations. We have shown, in support of a suggestion of LEMONTT (1971a), that the REV2 gene product is concerned only with the reversion of ochre alleles; it plays virtually no role in the reversion of amber, missense or frameshift mutations. We have also shown that its effect is specific and confined to only some highly revertible ochre alleles. The REV2 gene product appears to enhance reversion at these sites by facilitating the conversion of two otherwise nonmutagenic photo-products into a single premutational lesion. UV-induced killing of rev2-1 strains was found to be significantly greater on fermentable rather than on nonfermentable media.


Properties of the translocatable tetracycline-resistance element Tn10 in Escherichia coli and bacteriophage lambda. A number of independent insertions into bacteriophage lambda of the translocatable tetracycline-resistance element Tn10 have been isolated and characterized. The physical positions and relative orientations of several such insertions were determined. Two independent insertions appear to lie in the same orientation at or very near the same site in the cI gene, and two more lie in opposite orientations at or near the same position in or near the rex gene. Insertions in or near genes cI, rex, and cIII have been characterized genetically for their effects on expression of nearby genes. Tn10 appears to exert a polar effect on expression of distal genes when it is inserted within an operon, even when expression of that operon is under the influence of lambda N-function. In addition, Tn10 insertions in rex appear to influence in some way expression of an "upstream" gene, cI. Lambda derivatives carrying Tn10 give rise to spontaneously occurring, tetracycline-sensitive deletions at high frequencies. It is likely that formation of these deletions is promoted in some way by the Tn10 element. Lambda::Tn10 phages carrying a Tn10 element that has undergone several successive cycles of translocation since its first isolation and characterization have been analyzed. The results confirm that Tn10 often retains its physical and functional integrity during many cycles of translocation. Lambda derivatives carrying Tn10 have been used to generate insertions of Tn10 in the chromosome of Escherichia coli. This process is independent of recA function, and seems to be quite analogous to the translocation of Tn10 in Salmonella typhimurium as studied previously.


Reversion at the HiS1 locus of yeast.

Reversion at the HiS1 locus of yeast. The his1 gene (chromosome V) of Saccharomyces cerevisiae specifies phosphoribosyl transferase (E.C.2.4.2.17), the first enzyme of histidine biosynthesis. This hexameric enzyme has both catalytic and regulatory functions. The spontaneous reversion rates of seven his1 mutations were studied. The reversion rates of the alleles at the proximal end of the locus (relative to the centromere) were about 50-fold higher than distal alleles. Spontaneous reversion to prototrophy was studied in diploids homoallelic for each of the seven his1 mutations. Based on tetrad analysis, the prototrophy revertants could be assigned to three classes: (1) revertant tetrads that carried a prototrophic allele indistinguishable from wild type; (2) revertant tetrads that carried a prototrophic allele characterized by histidine excretion and feedback resistance; and (3) revertant tetrads that did not contain a prototrophic spore, but rather a newly derived allele that complemented the original allele intragenically. Four of the seven his1 mutations produced the excretor revertant class, and two mutations produced the complementer revertant class. The significance of these findings to our understanding of gene organization and the catalytic and regulatory functions of gene products are discussed.


Novel interallelic complementation at the his1 locus of yeast. In yeast, 17 histidine-requiring mutants derived from and interallelically complementary to his1-7 were analyzed. The genetic basis of the complementation response was elucidated by mitotic and meiotic gene conversion. Each allele probably carries an unaltered 7-site mutation and a unique second-site alteration. The second-site alterations appear to be clustered within the proximal and distal segments of the his1 structural gene. Models of intraalelic complementation are reviewed in light of the unique complementational response between a single-site mutant and a double mutant including the identical altered base sequence.


Abnormal mitochondrial genomes in yeast restored to respiratory competence. When crosses are performed between newly arisen, spontaneous petite mutants of Saccharomyces cerevisiae, respiratory competent (restored) colonies can form. Some of the restored colonies are highly sectored and produce large numbers of petite mutants. The high-frequency petite formation trait is inherited in a non-Mendelian manner, and elimination of mitochondrial DNA from these strains results in the loss of the trait. These results indicate that abnormal mitochondrial genomes are sometimes formed during restoration of respiratory competence. It is hypothesized that these abnormalities result either from recombination between mitochondrial DNA fragments to produce molecules having partial duplications contained on inverted or transposed sequences, or else recombinational "hot spots" have been expanded.


Cloning of the lacI gene into A ColE1 plasmid. The binding of lac repressor to lac operator was utilized to isolate an EcoRI fragment of lambda h80dlac (i+ as well as iq) that contains the lacI gene and lac promoter-operator regions. Ligation of this fragment into EcoRI cleaved pMB9 yielded chimeric DNA molecules of mol. w.t. 9.6 . 10(-6) and 1.5 . 10(7) daltons. Transformed strains containing the plasmids were analyzed for repressor production in vivo and in vitro. Repressor production in one plasmid strain is 7-fold greater than that in heat-inducible lambda h80dlac(iq)lysogens.


Factors affecting the transformation of Escherichia coli strain chi1776 by pBR322 plasmid DNA. The susceptibility of E. coli strain chi1776 to transformation by pBR322 plasmid DNA was examined and optimized. Maximum transformation to tetracycline (Tc) resistance was achieved when cells were harvested from L broth at 5.0--6.0 . 10(7) cfu/ml, followed by washing twice in cold 0.1 M NaCl + 5 mM MgCl2 + 5 mM Tris, pH 7.6. Cells grown in the presence of D-cycloserine (Cyc) rather than nalidixic acid (Nx) transformed markedly better. The presence of 5 mM Mg2+ ions in washing and CaCl2 solutions stimulated transformation about 2-fold. Optimal conditions for transformation included a pH range of 7.25-7.75 and a cell-to-DNA ratio of about 1.6 . 10(8) cfu/ng plasmid DNA. The frequency of transformation was highest when cells were exposed to 100 mM CaCl2 in 250 mM KCl + 5 mM MgCl2 + 5 mM Tris, pH 7.6, before mixing with DNA. A 60 min incubation period for cell + DNA mixtures held on ice produced the maximum number of Tcr transformants. In our hands, heat shocks at 37 degrees C or 42 degrees C for various times all decreased transformation to about one-half of optimal levels. Furthermore, the recovery of transformants was best when cell + DNA mixtures were plated on precooled (4 degrees C) Tc agar plates. The efficiency of plating was optimum when only 5 microliter of cell + DNA mixture was spread per plate, suggesting that non-viable background chi1776 cells on selective medium inhibited the recovery of transformants. It was also found that the presence of linear DNA molecules in cell + DNA mixtures markedly inhibited the transformation of chi1776 by pBR322 plasmid DNA. On the basis of these findings, a new procedure for the plasmid-specific transformation of E. coli chi1776 by pBR322 plasmid DNA is proposed. The use of this technique has allowed us to attain transformation frequencies in excess of 10(7) transformants/microgram pBR322 plasmid DNA.


Insertion of a transposon for chloramphenicol resistance into bacteriophage Mu. We have isolated mutants of bacteriophage Mu carrying the X mutations caused by the insertion of cam (Tn9), a transposon for chloramphenicol resistance. The Mu X cam mutants were obtained by selecting for heat-resistant survivors of a Mucts62, P1cam dilysogen. Like the previously described X mutants, Mu X cam mutants are defective prophages which can be excised from the host DNA at a frequency of 10(-5) to 10(-7) per cell. Tn9 insertions in Mu X cam mutants are located within 5000 base pairs of the left end of Mu DNA in a region that controls early replication functions of Mu. There is one EcoRI cleavage site in Tn9. The Tn9 transposon itself can be excised precisely from the Mu X cam mutants to generate wild type Mu. In most Mu X cam mutants, precise excision of Tn9 occurs at a low frequency (10(-6) per cell), whereas in some, the frequency is higher (10(-4) per cell). Mu X cam prophages can replicate after induction with the help of wild type Mu. The lysates containing Mu X cam particles, however, fail to transduce chloramphenicol resistance at a high frequency; Mu X cam mutants apparently have a cis dominant defect in integration.


Analysis of transposable elements inserted in the genomes of bacteriophages Mu and P1. We have examined the genomes of the temperate bacteriophages Mu and P1 and some of their insertion mutants for hybridization with the prokaryotic transposable elements IS1 and IS2. We used the DNA blotting-hybridization technique in which denatured DNA fragments are transferred to nitrocellulose paper directly from agarose gels and hybridized to 32P-labeled probe DNA. The 800 base pair insertion in an X mutant of Mu was found to hybridize with IS1. The chloramphenicol resistance transposon, Tn9, in Mu X cam mutants was found to be located at or close to the sites of IS1 insertion in X mutants; Tn9 also hybridized with IS1. The restriction endonuclease BalI cleaved IS1 once; it cleaved Tn9 in all Mu X cam mutants twice to release a fragment of about 1700 base pairs. These results support the conclusion that Tn9 contains one copy of IS1 at each end. In the P1cam isolate, from which Tn9 was transposed to Mu, BalI made a third cut in Tn9 giving rise to fragments of about 850 base pairs. The data further suggested that Tn9 is present in tandem copies in the P1cam isolate we examined. P1 itself was found to harbor IS1. The two P1 strains tested had a common fragment containing IS1; one strain had an additional copy of IS1. The IS1 element common to the P1 strains was shown to be the site of the Tn9 insertion in the P1cam isolate examined. No hybridization between IS2 and any of the Mu and P1 strains could be detected.


Heteroduplex electron microscopy of phage Mu mutants containing IS1 insertions and chloramphenicol resistance transposons. We have examined by electron microscopy the DNA heteroduplexes of six bacteriophage Mu mutants, Mu X cam, generated by the insertion of the Tn9 transposon for chloramphenicol resistance. Tn9 was found to be 2.8 +/- 0.2 kilobases (kb) in length and to consist of a cam determinant flanked by two IS1 sequences arranged in a direct order. In two of the six Mu X cam mutants, the Tn9 insertion was at a fixed location, 3.9 kb from the left, or c, end. In the other four mutants, the position of the insertion varied, even though the lysogenic cultures induced were grown from single colonies. The insertion was located at either 3.3 kb, 3.9 kb, or, less frequently, at 4.4 kb from the left end of the DNA. Furthermore, at low frequencies, the insertions were found to be in an orientation opposite to what predominated in the preparation. Thus, Tn9 in the Mu X cam mutants examined could appear to undergo rapid rearrangements during Mu growth or over a few generations of cell growth. One of the Tn9 insertion sites was apparently the same as that for a 0.8 kb insertion found in a Mu X mutant. This latter insertion was identified as an IS1 sequence. The DNA molecules from all the Mu X cam mutant phage particles were found to be missing the bacterial DNA at the S (right) end, along with a variable amount of the adjoining Mu DNA in the beta region. This observation supports the headful packaging model for Mu DNA.


SstI: a restriction endonuclease from Streptomyces sp. stanford. A strain of Streptomyces has been isolated which is a convenient source of a new restriction endonuclease. The enzyme has been prepared from extracts of these cells and its cleavage sites localized on phage lambda DNA. The enzyme, termed SstI, produces cohesive ends and should be useful for molecular cloning experiments.


Refined molecular weights for phage, viral and ribosomal RNA. The RNAs of the Escherichia coli bacteriophages MS2 and Qbeta as well as E. coli 16S ribosomal RNA were examined under identical conditions by electron microscopy using the protein-free benzyldimethylalkylammonium chloride (BAC) spreading technique. From the contour length ratios of the RNAs and the known number of nucleotides for MS2, the chain lengths for Qbeta RNA and 16S RNA were found to be 4790 +/- 150 and 1645 +/- 55 nucleotides. Correcting for the base composition of Qbeta RNA the molecular weight of the Na salt of this RNA is (1.64 +/- 0.06) . 10(6) daltons. Since published values on the relative lengths of Qbeta RNA and several other homogeneous RNAs (E. coli 23S rRNA, E. Coli bacteriophage R17 and f2 RNAs, Pseudomonas aeruginosa phage PP7 RNA and Newcastle disease virus RNA) are available, we are able to calculate the approximate number of nucleotides for these useful standards.


Amplification of the respiratory NADH dehydrogenase of Escherichia coli by gene cloning. A relatively simple method has been used to clone the gene coding for the respiratory NADH dehydrogenase (NADH-ubiquinone oxidoreductase) of Escherichia coli from unfractionated chromosomal DNA. The restriction endonucleases EcoRI, BamI and HindIII were used to construct three hybrid plasmid pools from total E. coli DNA and the amplifiable plasmids pSF2124 and pGM706. Three different restriction endonucleases were used to increase the chances of cloning the ndh gene intact. Mobilization by the plasmid F was used to transfer the hybrid plasmids into ndh mutants and selection was made for Apr and complementation of ndh. DNA fragments complementing ndh were isolated from both the EcoRI and HindIII hybrid plasmid pools. The strain carrying the hybrid plasmid constructed with EcoRI produced about 8--10 times the normal level of the respiratory NADH dehydrogenase in the cytoplasmic membrane. Treating the cells with chloramphenicol to increase the plasmid copy number allowed the level of NADH dehydrogenase in the membrane to be increased to 50--60 times the level in the wild type. The results indicate the potential of gene cloning for the specific amplification of particular proteins prior to their purification.


Isolation and analysis of recombinant DNA molecules containing yeast DNA. 2500 recombinant plasmids containing insertions of yeast nuclear DNA have been cloned in Escherichia coli. It can be calculated that about 85% of the yeast genome is represented in this collection. The clones have been characterized by hybridization to purified RNA species. Of the 2000 clones examined, 75 contain insertions of yeast ribosomal DNA, 201 contain insertions of yeast tRNA genes, and 26 contain DNA sequences that are complementary to abundant mRNA species.


[Gunshot wounds in peace and their treatment. Review of the literature]. For therapy of bullet-wounds in peace profound knowledge of their pathogenesis is necessary. This may be especially true for wounds evoked by new developed weapons. It may be assumed that often therapists are not familiar with the effects of these modern weapons. This review of 27 international publications therefore represents particularities of wounds of the body cavities and the extremities. Furthermore the problem of bulletembolies is represented.