[Stress tolerance of different osteosynthetic procedures in pertrochanteric fractures (author's transl)]. To obtain valid information on stress tolerance of pertrochanteric fractures, we exposed three different methods of osteosyntheses to dynamical stress and the results were compared. The methods of osteosyntheses were application of a 130 degrees angle plate, performing an adjoining osteosynthesis with bone cement or using cephalocondylar nails. The measurements in connection with photographical and roentgenological examinations of osteosyntheses under stress gave the following results: Compared with the other methods treatment with condylar nails gave equal results in static behaviour yet was clearly superior in its dynamic reaction.


[Experimental investigations to the problem of a stress of compensation of the contralateral hip after hip arthrodesis (author's transl)]. It has been demonstrated through experimental investigations that the periankylotic locomoter center of the non stiffened hip after hip arthrodesis by the moment of a stress of compensation according to the age of the arthrodesis must leed to a coxarthrosis.


[Lunatomalacia therapy. II. Operative treatment (author's transl)]. This report concerns the post-operative examination of 26 patients operated for 27 lunate bone necrosis. The following treatments were given: conservative (7), alloplastic (6), partial or total wrist arthrodesis (6), interposition tendon graft (5) and denervation of the wrist (1). The longest period of observation, an average of 13 4/12 years (maximum 21 years) was with the methods which have been grouped together under the heading conservative, after A. Beck (2), Konjetzny (2), Schneider (2), and Matti (1), the shortest period with the alloplastics and interposition tendon graft. Strict criteria were applied and the conservative method was judged "good" in only 2 cases whereas the interposition tendon graft, despite several disturbances in the carpal structure, produced 3 good subjective results. The metal endoprosthesis, which cannot be sutured, is not to be employed again because of the possibility of complications. A report on the results of arthrodesis of the wrist has already been published (Reichelt, 1973, 1975).


[Aneurysmal bone cysts (author's transl)]. Authors describe histological observations of 15 cases of aneurysmal bone cysts. Frequent occurrence of areas similar to giant cell tumor or solitary bone cyst was found together with fields producing chondroid intercellular substance. Attention is called to the differentiation of the two lesions described above and occasionally tumors and tumor-like conditions of chondroblastic origin. The vascular changes observed in the surroundings (arteriologsclerosis) support the earlier hypotheses attaching importance to local hemodynamic disturbance in the pathogenesis of the lesion. In certain cases penetration of aneurysmal bone cyst into the epiphyseal cartilage was found. Previous infraction or recurrence does not alter the histological picture fundamentally.


[On myositis ossificans localisata and its operative treatment (author's transl)]. We observed 52 patients with myositis ossificans localisata partly of a traumatic, neurogenic or morbid (inflammable) origin. The fact that preferably young men are concerned in cases of traumatic and neurogenic myositis ossificans localisata is certainly not only caused by their increased exposition to trauma, but also by disposition. For indication and operative treatment it is necessary to classify as well as radiologically III different stages of development as respective groups of muscles. In posttraumatic and neurogenic cases relapses post operationem may probably be avoided in case, there is a radiological stage III (total development of muscle ossification).


[Development and application of a new polyurethane plastics support bandage (author's transl)]. Experiences with a newly developed plastics support bandage on 1007 patients are reported. A polyurethane hard foam composition developed specially for medical purposes was used, which is created by blending the two components A (polyol) and B (isocyanate). The principle of our support bandage lies in the fact that after being mixed in a 1:1 ratio, the two highly viscous components are packed into a cotton stocking having a high transverse elasticity. After being rolled out to the desired thickness, the stocking is wrapped around the extremity which it is to support, where it hardens out into a polyurethane hard foam composition. By reason of the moisture content of the scoured cotton stocking, a 1 to 2 mm thick layer of foam forms in the contact region and renders any further padding unnecessary. Correspondingly, by using a double chamber stocking, circular bandages have been produced which can be removed, by means of incorporated zip and interengaging hook fasteners. Reclining shells, abduction bandages and body corsets can be made in the same way. The physical properties of the support bandage are illustrated: apart from its low weight, the bandage is particularly advantageous by reason of its high strength, insensitivity to water and ideal permeability to X-rays. The support bandages are easily made up and entail negligible cost.


[Hohmann's procedure for epicodylitis humeri ulnaris (author's transl)]. Report about 4 operations using Hohmann's procedure in therapy-resistent epicondylitis humeri ulnaris. The ulnar nerve was not seen during operation. The intervention is as simple as on the radial side. It can be recommended.


[Myelography--what is it really worth?]. The routinelike employment of myelography is attached and as follows established. 1. Primum non nocere! This old medical axiom also here has its validity, there are enough examples of incidents and late damages in employment of this method. 2. The myelography is not reliable. Errors are described. 3. Superfluous painful examinations should be spared for the patient: operation and myelography are two interventions. 4. The myelography costs time and prolongs staying in hospital.


[Kienböck's disease. Follow-up studies and therapeutic considerations (author's transl)]. This paper presents a follow-up of patients with Kienböck's disease up to 30 years after their first symptoms. Only the shortening of the radius and the grafting of the lunate with cancellous bone offers some kind of basic therapy. The intercarpal arthrodesis, the arthrodesis of the wrist and the operation named after Steinhäuser should only be considered in cases with severe deformation and disabling pain.


[Complications after total hip replacement (author's transl)]. Alloarthroplastic replacement of the hip comprises certain risks. Therefore good apparative and instrumental equipment and biological understanding of the post operative phase are necessary. Our rate of operative complications was 1.3% of all cases. In this number fat embolism after implantation of acrylic cement is of special interest. Reference is made of animal experiments on the pathogenesis of this phenomenon. Early complications comprise luxation of the prosthesis, bleeding and hematoma formation, iliotibial-nerve syndrome, phlebothrombosis, embolism, early infection. Late complications comprise infection and loosening of the prosthesis. In a total of 1200 implantations we had early complications in 1.8% and late complications in 0.9%. Reference is made of clinical and X-ray signs of loosening of the implant. Arthrography proved to be the most dependable method. We found periarticular calcifications in 30% of all cases. Fractures of the prosthesis were extremely rare: in few cases we found fractures of the polyestercup. In all cases the aggressive granuloma will leed to rarefication of bone sooner or later going along with loosening of the implant.


[About the relief of severe spasticity in paraplegics (author's transl)]. The treatment of spasticity following spinal cord injuries demands a well coordinated team of neurologists, neuro-surgeons, surgeons and orthopedic surgeons. The causes of the beginnings of spasms, circumstances, by which the intensity of existing spasticity is supplementary advanced, will be described. The intensity of spasms in joints of the paralysed limbs can be improved by controlled "Passive Body Exercises" for a short time. But we have never seen relievings of spasticity by drugs. In certain cases a systematic rehabilitation takes only effect, if intractable spasticity--especially concerning the knee and hip joints--is either completely removed or at least recovered. By means of a posterior rhizotomy by Förster (posterior nerve rotts section) spasms following traumatic spinal cord lesions can be eliminated completely or at least changed for the better just depending largely upon the level of the injury to the cord.


[Cytological examinations of synovial for judgement arthrotic conditions at knee joint (author's transl)]. Even if you use very refinded methods of investigation, there might be some difficulties in the estimation of praearthrotic and arthrotic conditions in the knee joint, especially under the aspect of differential diagnostical considerations. In those cases all the diagnostical measures available should be applied. In this paper the value and power of evidence of cytological investigations with arthrotic alterations of the knee joint are checked. For this purpose some synovial liquid was punctured in 25 cases--chosen out of a total number of 140--of operations (mostly on behalf of suspectes meniscopathy). The liquid was worked up in the method found by Vojtisek and analysed. It was possible to correlate the thus found results (analysis of the differential cell formation) with the findings which were objectively gained during the operation. Thereby you could see that the macroscopically visible changes of the synovialis, the menisci and the cartilage, which were divided into 5 groups regarding their form and their degree of significance, allowed a comparison with the findings of the differential cell formations. It is possible to attach certain forms of the differential cell formation to varying macroscopic-anatomic changes of the knee joint. The results are thoroughly discussed.


[Roentgenologic and morphologic studies of experimental tibial-plateau fractures (author's transl)]. Experimental tibial-plateau fractures had been produced to a series of 12 knee joints of corpses. The knee-joints had been exposed to vertical pressure in an extended position. The exerted pressure and the achieved deformation had been noted down in a diagram. The following radiological and morphological examination of the specimen showed that clear impressed fractured had arrived in case of a small deformation, whereas stronger compression had always caused combinated impression and split fractures. Impressions up to a depth of 3 to 5 mm cannot be proved radiologically. A certain unknown figure must be reckoned with in cases of distorsions of the knee-joint without a striking radiological finding. This will, however, hardly involve therapeutic consequences, because the carrying capacity of the tibial condyle will not be considerably reduced by such small impressions, and there is no fear of a further impression under load.


[The influence of immobilisation on the alcaline phosphatase activity from adults and children (author's transl)]. Alcaline phosphatase activities in the sera from 75 children of the age of 2-9 years were determined after immobilisation of various degree. A significant decrease of enzymatic activity was to be seen with increasing immobilisation, in contrast to the adult, where the immobilisation had no influence on the alcaline serumphosphatase.


Otitis media and linguistic incompetence. In the examination of some effects of chronic middle ear disorders on the development of auditory processing skills in socioculturally disadvantaged children, three groups of children received a battery of tests assessing speech hearing in quiet, speech hearing in noise, auditory discrimination, phonemic synthesis, dichotic listening, verbal intelligence, and nonverbal intelligence. The experimental group consisted of 14 Australian aboriginal children with histories of chronic middle disorder, whereas two control groups, one European and the other aboriginal, each contained 18 children with normal middle ear function. The results demonstrated that chronic middle ear impairment not only restricts the development of some auditory processing skills, but distorts their integrational pattern.


Viral infection as a cause of acute peripheral facial palsy. Among 51 patients with acute peripheral facial palsy, varicella-zoster virus was isolated from the cerebrospinal fluid (CSF) in one case, and Herpesvirus hominis from the nasopharynx in two cases. In 12 other cases, complement-fixing antibody or hemagglutination inhibition tests indicated a recent viral infection (varicella-zoster, seven; herpes simplex, one; cytomegalovirus, one; influenza type B virus, two; and mumps virus, one). One additional patient had clinical signs of herpes zoster oticus. About one third of these 16 virus-positive patients, but also one third of the remaining group, had increased levels of alpha 1-antitrypsin, orosomucoid, haptoglobin, and immunoglobulins. Evidently, an inflammatory reaction preceded or coincided with the facial palsy in both groups. In CSF, an increase of total proteins and gamma-globulins was frequently found among all 20 patients examined (eight were virus-positive).


Laryngeal vibration patterns. Machine-aided measurements from high-speed film. A report is given on the development of procedures to process laryngeal high-speed films to extract the glottal wave-form and other glottal measurements. The glottal waveforms that are derived by this direct method are being used to determine whether the pathological larynx is manifested in its abnormal vibratory pattern. The glottal waveforms measured by sonic-sensing pen tracing, cursor outlining, a photocell technique, and television camera scanning are presented and compared with the conventional polar planimeter method. To date, the television camera method is the most rapid procedure and can process approximately 400 frames per hour in a semiautomatic mode. This method determines the glottal area, length, and width by a combination of analog-digital circuitry and minicomputer processing. This information is being used to explicate the exact nature of the vibrational patterns produced by the normal and pathological larynges.


Acoustic reflex characteristics in spastic dysphonia. Acoustic reflex characteristics were studied in six persons with spastic dysphonia. Two methods of analysis were used: (1) a double-blind qualitative judgment of acoustic reflex recordings, and (2) a quantitative analysis of specific temporal characteristics of the acoustic reflexes. Judgments of reflex recordings did not reliably differentiate spastic dysphonia subjects from controls. An analysis of five latency measures revealed a difference between groups only in one measure, reflex contraction time.


Action of inflammatory mediators on middle ear mucosa. A method for measuring permeability and swelling. We describe a technique for measuring changes of permeability and vasodilation-edema in middle ear and Eustachian tube mucosa when this tissue is challenged with an inflammatory mediator. A ten-minute exposure to histamine, bradykinin, and prostaglandin E1 or E2 causes marked increases in permeability and a vasodilation-edema that lasts from 30 minutes to two hours. The passage across the mucosa of a small ion-pertechnetate-is increased by these mediators. Protein molecules, normally prevented from permeating the blood-mucosal barrier, permeate in substantial amounts after the middle ear mucosa is challenged with inflammatory mediators. Thus, the mediators seem capable of producing two of the cardinal signs of middle ear inflammation. They may be the proximal cause of middle ear effusions and their continued presence may be responsible for the chronic nature of this disease.


Cross-sectional area of scala tympani in human and cat. The cross-sectional area of scala tympani is measured in midmodiolar sections of both human and cat temporal bones (20 pairs each). The areal sizes of scala tympani in different turns of human cochlea are more than twice those in the cat. A noticeable area reduction between the lower basal turn and the upper basal turn is found in the cat. The cross-sectional view of scala tympani is ovoid to round and flat on top in the basal turns, but it is more like a flat triangle in the lower middle turn and above. The area measurement of the scala tympani assists the development of the implantable electrode. The information also contributes to the construction of models for physiological experiments.


Functional veloplasty in bilateral palatal palsy. A new technique for the treatment of bilateral palatal palsy involves the submucosal transposition of the tensor palati muscles of both sides to form an active muscular sling for the elevation of the paralyzed soft palate. The effect of the rerouted tensor palati muscle on Eustachian tube function and its efficacy as a substitute for the levator palati muscle in lifting the soft palate was evaluated by animal experimentation. Subsequently, two patients with bilateral palatal palsy, who failed to show improvement during a six-month period, were treated successfully with this new surgical technique, "functional veloplasty", without complication.


The audiometric utility of brain stem responses to low-frequency sounds. The human scalp-recorded vertex-positive brain stem response to a click or high-frequency tone pip is an excellent audiometric indicator. Its latency of 6-9 ms is practically independent of the polarity of the stimulus but is inversely related to intensity. With a 4,800- or 2,400-Hz tone pip (filtered click) its threshold of detectability is usually at or below 10 dB SL. With a 500-Hz tone pip, with rise and fall of 2-3 ms, the response at 30 dBSL is low in amplitude, rounded in wave form, and has a latency of about 10 ms. When the polarity of the stimulus is reversed, the latency shifts by 1 ms. At and above 40 dB, this late response is obsured by a larger and earlier response. High-pass (1,500 Hz) masking noise does not affect the low-level response but the earlier high-level response is reduced in amplitude and delayed by about 1 ms. The large early response seems to be initiated by stimulation of the basal turn of the cochlea by the low-frequency transient. The frequency-following response (FFR) to a 500-Hz tone burst with a 2-ms rise time has a threshold at about 40 dB SL. Its relatively short latency is appropriate to the basal turn. A later low-amplitude apically generated response can sometimes be detected, either at a lower stimulus level or in the presence of high-pass masking noise. The usual FFR often has complex wave forms and some individuals show only an onset response, even at 70 dB SL. It is almost impossible to edentify with certainty the first individual waves of FFR as they relate to the individual waves of the tone burst and as they change amplitude with intensity. The audiometric usefulness of the high-threshold responses to 500 Hz that are initiated in the basal turn is doubtful. The low-threshold responses initiated in the apical turn are so difficult to identify with certainty that they are not likely to be of clinical value unless high-pass masking noise can be used to clarify them.


[Effects of duration on the equal loudness contours of short and brief tones: 40 phones equal loudness contours. Preliminary experiments (author's transl)]. Loudness balances have been obtained between 10-, 20-, 100- and 1,000-ms tones of different frequencies (62.5, 125, 250, 500, 1,000, 2,000, 4,000, 8,000 and 12,000 Hz), and a constant reference tone of 1,000 Hz and 1,000 ms duration at 40 dB SPL. The absolute thresholds were also measured on the same observers at each duration. Progressive shifts of the equal loudness contours appear when the durations become shorter, in the same direction as the corresponding shifts of the threshold curves; the shifts of the equal loudness contours and the corresponding shifts of the threshold curves do not however appear completely similar; some differences may also exist between tones of differing frequencies. These experiments were preliminary ones; some problems arise, in relation with the technique used; improvements appear necessary.


High-frequency audiometry above 8,000 Hz. Human auditory sensitivity for the frequencies 8, 10, 12, 16, 18, and 20 kHz was examined in a group of 41 female university students ranging in age from 19 to 22 years. The purpose of this study was twofold: to determine the feasibility of high-frequency testing using procedures routinely employed in clinical audiometry and to collect normative data using this procedure on a young adult population. A modified Hughson Westlake procedure was employed and thresholds were obtained for both ears of each subject. It was noted that for the 20-kHz tone only 52% of the subjects tested were able to respond. Statistical analysis revealed no significant threshold differences between right or left ears for all subjects at any frequency. The approach described in the present study provided reliable thresholds and was found to be clinically feasible. Comparisons were made with similar previous studies and the results of the present study were found to be in general, overall agreement.


Typing of Békésy audiograms.

Typing of Békésy audiograms. Jerger's method for classifying BEKESY AUDIOGRAMS is the most widely acccepted clinical classification system. The audiologist types the BEKESY audiogram based upon visual inspection of the relation between the continuous- and interrupted-tone tracings. To determine the extent of agreement among audiogram type, four expert judges using a forced-choice, blind procedure, independently typed 170 audiograms. Contingency coefficients were between 0.89 and 0.90 for the six sets of paired judges. Contingency coefficients between each judge and a numerical criterion classification system ranged from 0.86 to 0.94 representing the validity of the visual method. The visual method is a valid procedure for typing BEKESY AUDIOGRAMS.


Comparison of two methods to predict cochlear pathology from Békésy tracings. Two different methods for classifying cochlear pathology were applied to 62 BEKESY AUDIOGRAMS obtained from cochlear pathology subjects to determine which method was the better indicator of cochlear pathology. The two methods compared were: (1) Jerger's type II, which is based upon the difference (D) between the client's threshold for the interrupted-tone tracing and the threshold for the continuous-tone tracing; and (2) Bilger's Wc, which is the swing width of the continuous tone tracing for 4,000 Hz. Results indicated that D classified 62% of the audiograms (39) correctly, and Wc classified 52% of the audiograms (32) correctly. Both measures jointly classified 37% of the audiograms (23) correctly and jointly missed 23% of the audiograms (14). Statistical analysis showed no difference between the two methods in classifying cochlear pathology.


Speech audiometry for children and subjective probability of Polish words. Word lists used for speech audiometry should fulfill a number of conditions in order that the results of hearing tests be unambiguous and directly interpretable not only in terms of possible hearing loss but also in terms of the neurolinguistic decoding process. In order to construct a proper word list, it was decided to attempt to estimate the subjective probability of word occurrence in schoolchildren. Nine different lists of over 300 words each were prepared, containing words of all assumed degrees of familiarity. In the preliminary stage, the lists were presented to 600 children in primary and secondary schools. The children were asked to mark each word with a number indicating their relative familiarity with the word. The answers were examined for homogeneity.


Audiological status of children with cleft palate. A review of 350 cases. 350 children treated for cleft palate at the children's Hospital of Cape Town, have been followed by periodic examination at the Audiological Unit of the Groote Schuur Hospital over a period of 7 years. The incidence of middle ear disease has been found to be over 60%. Its frequency and severity has been assessed and the progress of the hearing loss in individual cases during childhood years has been followed in many instances. The causation is discussed and methods of management described. The incidence is correlated with the type of operation performed for cleft repair and with the age at which it was done.


Performance of hearing aids with an induction loop amplification system: laboratory versus classroom setting. This study was designed to investigate the acoustic response of ten body-type hearing aids when used with an induction loop amplification (ILA) system in the laboratory and in the actual classroom setting. Undesirable frequency response characteristics were discovered in the classroom ILA system used in this study. These consist of a slightly poorer low-frequency response and a deep notch at about 2,500 Hz. Had the frequency response of the classroom ILA system been flat, differences between laboratory and classroom measures would have been minimized. Findings of this study support the practicality of measurement in the classroom of the operating characteristics of ILA systems.


Masking level difference for speech: effects of ear dominance and age. A comparison was made of right and left ear discrimination of monosyllables presented with competing 'cocktail party' in conditions of signal monaural-noise monaural, and signal monaural-noise binaural and in-phase interaurally. The effects of these conditions were compared in 20 normal children aged 5-6 years, 40 normal young adults and 20 adults aged 66-76 years. The magnitudes of right and left ear masking level differences (MLDs) were compared at each age level. (1) MLDs occurred for all three age groups; (2) for the two adult age groups, mean right ear scores exceeded mean left ear scores in the case of monaural noise presentation, although the difference was significant only for the young adults; (3) no interaural difference appeared for the children, and (4) marked variability of the magnitude of the MLDs occurred among subjects of all three age groups.


Intelligibility of speech transduced via classroom-installed FM and conventional audio induction loop amplification systems. This study was designed to investigate the intelligibility of speech transduced through a classroom-installed FM system and a conventional induction loop amplification (ILA) system and to examine the applicability of an FM adapter when used with commercially available hearing aids. Findings indicate that speech reproduced via the FM system is significantly better than that of the conventional audio induction loop used in this study. It seems likely that the irregular high-frequency response of the ILA system was responsible for this difference. When an FM adapter was used in conjunction with body-type hearing aids, the frequency response of the telecoil along with the positioning of the adapter determine the total performance of the aid.


N1 latencies of the slow auditory evoked potential. Several studies have been published concerning the relation between stimulus level and amplitude of the slow auditory evoked response. Little attention has, however, been given to the relation between level and latency of the N1 component (100-200 ms). A mathematical model of such a relation is proposed based on the assumption of an exponential relationship. The model has been tested on normally hearing subjects as well as on patients with sensorineural lesions, cochlear as well as retrocochlear. The results indicate that the proposed method of evaluating the slow evoked responses offers a way of threshold extrapolation with rather good accuracy. It also appears to be useful in determining the type of hearing loss.


Reliability and validity of late vertex-evoked response audiometry. In order to evaluate the current visual scoring technique in the late vertex-evoked response audiometry (ERA), the detectability of the response, errors in judgment, consistency between scorers and test-retest reliability were studied in adults and young children in waking and sleeping states. In waking adults, ERA proved to be a quite reliable and valid method for testing hearing objectively. On the contrary, a marked inconsistency was found in the appearance of the response in children during sleep. From a clinical standpoint, ERA in waking adults and sleeping children should be regarded as two substantially different methods.


Relations between electric response audiometry, conventional audiometry and psychodiagnostic examinations in hearing-impaired children. To obtain a more objective determination of the hearing loss and thereby a more effective therapy, we compared the results of conventional audiometry (reflex and behavioural audiometry) with electric response audiometry (ERA) results in 522 children whose median age was 3 years. ERA threshold was more sensitive at 10.8 +/- 17.5 dB. The mean difference and its standard deviation are both much greater for the younger children and particularly for non-cooperative children, but neither relates clearly to intelligence. In the case of 'difficult-to-test' children (due to behavioural disturbance, mental retardation or brain damage), we carried out a psychological examination consisting of several special non-verbal tests. 62.7% of children with IQs under 70 needed sedation; for the children whose IQs lay above 70, this proportion was only 37.3%. Our artefact rejection system greatly reduced the percentage of sedations required, particularly for children under 3 years of age.


Use of frequency-shifted/time-compressed speech with hearing-impaired children. Several electromechanical aids to education for hearing-impaired children have been studied. One method that has received minimal attention is that of frequency-shifted/time-compressed (FS/TC) speech. This study was designed to determine if intelligibility scores on a standard intelligibility measure for children, whereby the words on the test was modified by 35% FS/TC, would show improvement from a pre- to a post-testing session. Nine hearing-impaired children were presented a 0 and 35% FS/TC speech pretest, then trained for 15 days using 35% FS/TC speech signals, and subsequently were presented a 0 and 35% FS/TC speech post-test. A second group of 9 hearing-impaired children were presented similar pre- and post-tests, but were trained under a 0% FS/TC speech condition. The group trained under the 35% FS/TC speech condition showed score gains from the pre- to post-test session, whereas the 0% FS/TC speech group showed essentially no gains from the pre- to the post-test session. The potential application of FS/TC speech to the education of hearing-impaired children were discussed.


Binaural speech discrimination.

Binaural speech discrimination. The phenomenon of binaural summation in which the addition of signals presented to the two ears simultaneously takes place at a central level, has been known for many years. It is reasonable to assume that the pattern of summation differs between subjects with central lesions and those with lesions in the peripheral auditory tracts. Various tests have been proposed to aid in locating the site of the lesion which compare the monaural and binaural speech discrimination scores. In the present work, two of these tests have been examined. Three groups of subjects have been used: (1) a normally hearing group; (2) a group with hearing impairment resulting from cochlea pathology, and (3) a group with hearing impairment resulting from lesions at the level of the cochlear nuclei. The results showed that neither test differentiated between peripheral and cochlear nuclei lesions.


Threshold improvement and acoustic gain with hearing aids. Aided speech reception thresholds were obtained from 20 hearing-impaired listeners with three hearing aids adjusted to confort settings, and with the aids adjusted to deliver 40 dB of acoustic gain. The aided speech reception threshold under each condition was substracted from the unaided speech reception threshold to yield a measure of threshold improvement. Threshold improvement and acoustic gain comparisons revealed that, at comfort setting, these two measures were quite similar. However, at the 40-dB gain setting, acoustic gain exceeded threshold improvement by an average of 5.6 dB. For the high-gain condition, it appeared that the threshold improvement obtained by subjects with relatively good unaided sensitivity was limited by the ambient noise in the test chamber.


Speech audiometry and fitting of hearing aids in noise. Conventional speech audiometry, performed in a noise-free testing room, often gives only little information on the patient's impairment of speech perception in daily life. A sensitized form of free-field speech audiometry is suggested which simulates everyday speech perception and, at the same time, supplies comparable and reproducible results. The test material consists of phonetically balanced sentences. From separate loudspeakers, a standardized environmental noise with a constant sound pressure level, 50 dB(A) is admixed. By this technique, certain handicaps in speech perception, undetected by conventional test procedures, can be revealed. Above all, the results are in good accordance with the subjective assessment of disability. A standardization of 'handicap speech audiometry' based on these principles is therefore suggested. The comparative hearing-aid fitting in noise improves the final selection with special regard to practical use.


An evaluation of the Australian beef carcase appraisal system. The australian Beef Carcase Appraisal System (ABCAS) which evaluates the commerical worth of carcases by scoring fat percentage, estimated from carcase weight and fat thickness, and by scoring muscle weight, estimated from rib-eye area (REA) and carcase length (CL), was used on 45 steer carcases. Scores were related to carcase components determined by total dissection. ABCAS underestimated fat percentage in 44 of the 45 carcases, the degree increasing with carcase fatness. In 26 of the 44 carcases (59.1%) fat was underestimated by over 7%. Twenty-nine of the 45 carcases (64.4%) received more points for the ABCAS estimates of fat percentage than for dissected values. Nine (20.0%) received the same score for the estimate but in 7 of these this was the minimum score for overfatness. Seven carcases only (15.6%) scored less for estimated fat percentage, 6 of these resulting from under-estimations on the ABCAS scale. Nine carcases which should have been penalised for overfatness were penalised for underfinish. ABCAS adjustments to estimated fat percentage for carcase weight were contradicted because of the small (0.03) but highly significant positive regression of fat percentage on carcase weight. ABCAS scores for carcase muscle, based on REA and CL were neither closely nor consistently related to dissected muscle percentage. The range of dissected muscle in the fat-free carcase (72-81%) was not accurately reflected by the ABCAS points score range (14-46). REA and CL were not satisfactory predictors of carcase muscle. It is concluded that differences in weight or percentage of muscle between carcases at constant fat-free carcase weight may be too small to determine accurately using current prediciton parameters. A useful estimation of the commercial value of a carcase may be based on cold carcase weight and fat thickness at the 10th rib. Two equations utilising these measurements are given for estimating fat percentage and muscle weight.


Bovine nasal granuloma in Victoria -- a search for the causative allergens. Cows with nasal granuloma showed skin sensitivity to a range of environmental allergens while clinically normal control animals showed little sensitivity. The allergens producing the greatest number of positive reactions included the pollens of dock, capeweed, clover, paspalum, sorrel, rye grass, pepper tree and wattle, the spores of penicillium, cladosporium, botrytis and rye grass rust and extracts of sheep's wool and mite. It is likely that different allergens are important in different animals and in different regions and their importance in the aetiology of nasal granuloma probably depends on their presence in the inhaled air in high concentration for long periods.


[The use of the stapedius reflex in the fitting of hearing aids (author transl)]. The authors made experiments concerning the stapedius reflex without and with an hearing aid; there is a relation between this reflex and the discomfort threshold for the selection. The stimulus is given on a loudspeaker and the stapedius reflex permits in some cases to know the gain of the hearing aid and also the limit of discomfort. This method very useful particulary for children is objective.


Bovine nasal granuloma: a review.

Bovine nasal granuloma: a review. The literature on granulomatous nasal diseases of cattle is reviewed, with emphasis on nasal granuloma, a disease of unknown cause which is enzootic in Australian dairy cattle. It is concluded that on available evidence the disease is most probably a form of allergic rhinitis.


An economic analysis of two schemes for the anthelmintic control of helminthiasis in weaned lambs. The economic benefit obtained from 2 schemes for the strategic control of helminthiasis in weaned lambs has been assessed in the Western District of Victoria. The results were compared with those from sheep in control groups which were given a single anthelmintic treatment during an outbreak of helminthosis. Mortality in sheep receiving the critical treatment scheme of 2 appropriately timed anthelmintic treatments was 12%, compared with 22% in the group receiving the traditional series of summer and autumn treatments, and 26% in the control group. As a result of this difference in mortality rate, the critical treatment scheme was the most profitable control strategy at 1970-71 prices, yielding a net benefit of $70 per 100 sheep in comparison with the control group which received no strategic treatment. This is 538% return on funds invested in anthelmintic treatment. The benefit from this scheme was not unduly affected by variation in wool or sheep prices, nor to possible differences in mortality rate within the expected range. The traditional treatment scheme also yielded positive net returns, but the results were adversely affected by a small change in mortality rate and therefore could not be recommended for routine use on commerical farms.


Effects of reflex middle-ear muscle contractions on cochlear responses to bone-conducted sound. The effects of contralaterally elicited middle-ear muscle (MEM) reflexes on cochlear microphonic responses to air- and bone-conducted tones were examined in decerobrate cats. Stapedius effects on bone condn air conduction were almost identical in configuration and amplitude to those on air conduction at all frequencies. However, tensor tympani effects were more complex, the configuration of the bone-conduction effects varying with the location of the transducer on the skull and with frequency. The relative contributions of the two muscles to the effects of joint contractions varied markedly between animals. It is suggested that non-reflex MEM contractions associated with activity of the facial musculature might provide protection against masking of environmental sounds by the low-frequency bone-conducted sound generated by such activity.


A comparison of worm burdens in grazing merino sheep and angora goats. The worm burdens of Angora and Merino wethers grazing with their own species or in a mixed flock were compared over a 4 month period. Based on faecal egg counts and larval differentiation, all animals had similar levels and types of infection at the beginning of the experiment when they were 15 months old. Although the initial infection in sheep and goats was similar, sheep subsequently developed a stronger resistance to worms. Therefore, at the termination of the experiment the sheep had significantly fewer worms of all species, except Nematodirus, than did the goats. There was no significant within-host difference in worm burdens whether the animals grazed exclusively with their own species or in the mixed flock.


The isolation of Bordetella bronchiseptic from an outbreak of canine pneumonia. This report describes an outbreak of bronchitis and bronchopneumonia among young dogs in a breeding kennel following the introduction of two pups from another area. Bordetella bronchiseptica was isolated in heavy culture from affected animals which responded well to antibacterial therapy. There was no evidence of distemper virus involvement. Important bacteriological properties of Bord. bronchiseptica are discussed particularly as they relate to its known pathogenicity in the young of several species of animal. During the outbreak reported, it was noted that only young pups were clinically affected and it is suggested that Bord. bronchiseptica may be pathogenic in a certain age-group within the canine population. This seems to require further investigation.


Efficacy of chlortetracycline against Mycoplasma synoviae isolated in two periods. Isolates obtained in 1954-55 were generally more pathogenic for the synovial membranes than those obtained in 1969-73. All isolates were capable of producing synovitis when inoculated into the foot pad. Chlortetracycline was effective in controlling signs of infectious synovitis at the 100-g/ton concentration. The 50-g concentration prevented mortality and reduced morbidity. All concentrations of chlortetracycline used (50, 100, or 200 g/ton of feed) reduced immune response, positive agglutination tests, and isolation of MS below that of inoculated untreated birds. Chlortetracycline at all concentrations prevented the spread of MS in contact controls. Chlortetracycline was more effective against the 1954-55 isolates than the 1969-73 isolates when measured by gross lesions, development of agglutinins, and isolation of mycoplasma. No difference in efficacy was found in mortality, weight gain, and feed efficiency.


Detection of four serotypes of avian adenovirus in New Zealand. Twenty agents with adenovirus morphology were recovered from New Zealand domestic hens by means of chick kidney cell cultures. All the agents gave distinct cytopathic effects (CPE) in cell cultures, with two different types of CPE observed. On the basis of neutralization tests, the twenty agents were assigned to four distinct serological groups. Physicochemical tests on a "prototype" strain from each serological group confirmed that these agents are adenoviruses. The four prototype strains recovered in New Zealand are related to established overseas strains. One strain is serologically related to agents that cause IBH.


Serologic studies with Mycoplasma synoviae in experimentally inoculated chickens. Three strains of Mycoplasma synoviae (MS) (Olson-WVU 1853, reported in 1956; and Massachusetts 9895 and 5044, respectively isolated in 1957 and 1972) were used for experimental inoculation of chickens to evaluate the various mycoplasma serologic tests. The MS plate agglutination and hemagglutination-inhibition (HI) tests were highly sensitive for detection of infection; reactions persisted for test periods extending to 63 weeks. Correlation between MS HI-tube and micro methods was good. HI titers were highest in sera from birds inoculated with strain 9895. All three strains produced cross-reactions with M. Gallisepticum (MG) plate antigens, which were detectable for 2 to 12 weeks following MS inoculation; strain 5044 produced the lowest percentage of cross-reactions. MG HI titers of 16 were observed occasionally in sera from all three group inoculated with strain 1853. It appears from these limited serologic studies in chickens that there may be antigenic differences among the three MS strains.


Studies on genetic and vaccination-induced resistance of chickens to lymphoid tumor transplants. 1. Marek's disease tumor transplant (JMV). Six strains and 4 inbred lines of chickens that differed in susceptibility to Marek's disease (MD) were inoculated in the wing web with JMV when 5 weeks old. Wing web tumors (WWT) developed in all strains and lines inoculated with low-passage JMV (JMV-L) but were largest in Cornell Strain S (highly susceptible to MD). Of 3 strains inoculated with high-passage JMV (JMV-H), only Strain S had appreciable WWT development. Seventy-five percent of the unvaccinated S strain chickens challenged with JMV-L or JMV-H died during the experiments, and approximately half of this mortality occurred during the second week postinoculation. Inbred Line GC ranked next in susceptibility to Strain S and was more susceptible than other lines and strains, including the strain from which it originated. Vaccination with turkey herpesvirus one week before challenge protected against mortality and suppressed WWT development. The effect on WWT development was less, however, in Strains S and NH than in other strains.  The transplantability of the tumor was investigated with the use of sex chromosomes as cell markers. Five to 7 days postinoculation of male Strain S chicks with JMV-L or JMV-H, most cells in metaphase from wing web or visceral tumors were of female origin. By 56 days, only male cells were found in visceral tumors. The interpretation was that early lesions were due to tumor transplantation and later lesions were induced by virus.


Agarose droplet method of macrophage migration-inhibition test of Newcastle disease virus in chickens. The migration of peritoneal exudate cells collected from chickens immunized against Newcastle disease virus was inhibited by the inactivated virus antigen. The agarose droplet method for macrophage migration-inhibition test in chickens is described.


Studies on genetic and vaccination-induced resistance of chickens to lymphoid tumor transplants 2. Transmissible lymphoid tumor of Olson. Transmissible lymphoid tumor (TLT) was inoculated in wing webs of five-week-old chickens of 6 strains. About half of the chickens of each strain had been vaccinated with turkey herpesvirus (HVT) one week before challenge in the wing web with TLT. Tumors which developed at the site of inoculation usually reached maximum size within 2 weeks and then regressed. In some chickens, however, tumors developed in visceral organs and caused death in the 2nd through 5th weeks postinoculation. Comparisons among strains of chickens in Expt. 1 revealed no differences in mortality. Vaccination with HVT reduced mortality and also the incidence of wing-web tumors (WWT) in all strains of chickens. A lymphoid leukosis virus and a Marek's disease (MD) virus of low virulence were detected in preparations of TLT, and it is suggested that the immunity induced by vaccination may have been directed against tumor antigens associated with MD virus.


Competition between nonplaquing and plaquing strains of Newcastle disease virus as affected by temperature. If lentogenic (nonplaquing) strains of Newcastle disease virus were inoculated into a monolayer of chicken embryo fibroblasts before velogenic (plaquing) strains, the plaquing of the latter were inhibited partially or completely. An interval of 22 hours between the two inoculations gave greater inhibition than did 1 hour. In general, lentogenic strains grew better at 37 C (inhibited plaquing more effectively) than at 42 C. Enzootic velogenic strains that produce a neurotropic form of the disease in chickens were inhibited more than were exotic velogenic strains that produce a viscerotropic form. The lentogenic strains differed markedly in ability to interfere with velogenic strains.


Aerosol vaccination against Newcastle disease. II. Effect of vaccine diluents. Three diluents (deionized water, 2% dry milk, and 20% buffered glycerin) were used to suspend the Newcastle disease vaccine for aerosol-vaccination studies. Particle size and the effect on humoral antibody response in chickens was determined for each diluent. For all diluents, the greatest number of particles were found in the size range of 0.5-3 mum. Total particle counts were higher with glycerin than with either milk or water. Antibody response and resistance to challenge, however, were higher with water or milk.


Natural resistance to Marek's disease at hatching in chickens lacking maternal antibody, and relationship between this early resistance and resistance acquired with age. Chickens of lines 6 and N, selected for resistance to Marek's disease (MD) and lacking maternal antibody, were resistant to MD mortality when exposed to pathogenic MD virus (MDV) at 1 day old. This finding indicated that natural resistance to MD is well developed at hatching in certain lines and is not dependent upon increasing age. Evidence obtained for lesion regression in early resistance and for possible genetic control of resistance acquired with age indicated that resistance at hatching and that acquired with age may be similar in character and may represent early and late manifestations of common natural resistance, possibly mediated through similar mechanisms.


Studies on Pasteurella multocida. III. In vitro assay for cell-mediated immunity. Peripheral blood lymphocytes (PBL) from turkeys immunized against fowl cholera with a bacterin or a live avirulent vaccine (strain CS-148) were cultured in vitro with various antigenic preparations from Pasteurella multocida (strain P-1059). The degree of lymphocyte stimulation (blastogenesis) was quantitated by measurement of the uptake of (3H) thymidine. Higher stimulation indices were obtained with immune lymphocytes rather than nonimmune lymphocytes. Stimulation was specific since PBL from turkeys immunized against P. multocida failed to react with Escherichia coli or Mycoplasma synoviae antigens. These differences were statistically significant as analyzed with the student's t-test. The lymphocyte transformation assay was emphasized as a convenient and useful in vitro indicator of cell-mediated immunity that should help define the role of cell-mediated immunity in P. multocida infections of turkeys.


Evaluation of avian mycoplasma membranes as antigens. Mycoplasma gallisepticum and M. synoviae membranes were obtained by lysing mycoplasma cells with carbonate bicarbonate buffer at pH 10. Membrane preparations were compared with whole-cell preparations as to efficacy in the plate and tube agglutination and hemagglutination-inhibition tests. Membrane antigens were somewhat more sensitive in the plate and tube agglutination tests, whereas the hemagglutination-inhibition test showed no major difference between whole and membrane antigens. The membrane preparations were equal to whole-cell antigens in specificity.


Cooperative state-federal turkey ornithosis task force, Texas, 1974. Ornithosis was suggested by a routine analysis of tissue specimens from Texas turkey flocks submitted to the Texas A&M University Poultry Disease Laboratory at Gonzales on April 30, 1974, and of subsequent specimens from four additional flocks. Subsequently, illness in humans at turkey processing plants in Texas, Nebraska, and Missouri, implicating turkeys from Texas, was confirmed as ornithosis in July 1974; and, associated with this outbreak, ornithosis was suspected as the cause of the death of one human. Action was taken by state and federal poultry disease control and inspection officials, public health agencies, and the turkey industry in Texas.


Observations on the transmissibility of lentogenic strains of Newcastle disease virus: significance of variables. Virus strain and age of chicken influenced the transmissibility of lentogenic strains of Newcastle disease virus (NDV). The ability of LaSota, B1, V4, CT, F, and Ulster strains to spread from cages of oronasally inoculated chickens to adjacent cages of susceptible chickens was assessed by virus isolation, serology, and immunity to challenge with virulent NDV. Although all inoculated chickens were immune to challenge, the immunity of contact chickens ranged from 100% for LaSota and CT strains to 0% for Ulster strain. The transmissibility of B1 and V4 strains for chickens 1, 4, 8, and 16 weeks old was assessed by within-cage contact infection, exposure to contaminated food and water containers, and exposure to air from infected chickens. Serology and immunity to challenge with virulent virus were used as criteria. Differences in transmissibility were observed for the strain of virus used, route of exposure, and age of chickens. Care must be used in interpreting the significance of strain differences until the effect of variables can be minimized by further improvements in design of the test procedure.


Efficacy of monensin against turkey coccidiosis in laboratory and floor-pen experiments. Monensin at 60, 80, or 100 ppm in feed reduced mortality and lesion scores while protecting against weight loss of turkeys infected with the major pathogenic species: Eimeria adenoides, E. meleagrimitis, and E. gallopavonis. With single and mixed infections in battery-cage experiments, the death rate of unmedicated turkey poults was 33-75%. Weight gains were significantly (P is less than or equal to 0.05) better with 100 ppm monensin than 60 ppm, as were also lesion scores. Under floor-pen conditions there were no significant differences among monensin treatments. Moisture content of the litter was significantly lower in all monensin-medicated pens (40%, compared with 52% moisture in pens of unmedicated controls).


Effect of route of Newcastle disease vaccination on the incidence of airsacculitis in chickens infected with Mycoplasma synoviae. In two separate experiments, broiler-type chickens were vaccinated at 11 days old with either the B-1 or LaSota strain of Newcastle disease virus (NDV) by aerosol, drinking water, or eyedrop and simultaneously infected with Mycoplasma synoviae (MS). The MS-infected and aerosol-vaccinated chickens had the highest mean lesion scores for airsacculitis. The aerosol-vaccinated groups had the highest hemagglutination-inhibition titers against NDV. Infection with MS had no effect on antibody titers against NDV, and there were no consistent effects on weight gains.


Changes in glucose, insulin, and growth hormone levels associated with bedrest. Changes in plasma glucose, insulin, and growth hormone (HGH) resulting from exposure to 56 d of bedrest were determined in five healthy young male subjects. Blood samples were collected by repeated venous puncture at 4-h intervals for 48-h periods before bedrest, at 10, 20, 30, 42 and 54 d after confinement to bed and at 10 and 20 d after bedrest. Changes in the daily levels of these factors for each subject were expressed as the mean of the six samples per 24-h period. The level of HGH dropped after 10 d of bedrest, then showed a 1.5-fold increase at 20 d (p less than 0.05) and subsequently decreased gradually reaching levels of 2.5 mg/ml/24 h, well below pre-bedrest controls of 4.2 mg/ml/24 h, by the 54th d. In spite of a marked increase in the daily plasma insulin levels during the first 30 d of bedrest, glucose levels remained unchanged. Beyond 30 d of bedrest, insulin began decreasing toward pre-bedrest levels and glucose followed with a similar reduction to below the control levels of 75 mg/100 ml/24 h on day 54. The daily mean changes reflect a change in the amplitude of the diurnal variation. The daily peak in plasma insulin shifted progressively to the late evening during the bedrest period.


The occurrence of virus in leukocytes of vaccinated chickens following challenge with virulent Newcastle disease virus. Chickens that had been vaccinated with a lentogenic strain 2 to 9 weeks before challenge with a virulent virus remained clinically normal following challenge and circulated virus within leukocytes for as long as ten days. The virulent virus was detected by inoculating embryonating eggs with leukocytes separated from blood shortly after drawing. Freezing the leukocytes before inoculating the eggs reduced isolation 64.8%. Virus was demonstrated most readily in chickens challenged when antibody was decreasing, about 9 weeks after vaccination. The observation that virus in blood may be contained within a cellular component and be readily demonstrable only if the cells are separated and washed is significant both to an understanding of the immunological responsiveness of vaccinated chickens exposed to field challenge and to an understanding of epizootiological events.


A presumptive diagnosis in the fowl (Gallus gallus domesticus) from Assam (India). In postmortem examination of carcasses of White Leghorn chickens, 3 had typical gross lesions of necrotic enteritis affecting the small intestines. The occurrence of avian necrotic enteritis was noticed after an outbreak of coccidiosis had subsided. On the basis of the gross and microscopic examination the disease was differentiated from coccidiosis and ulcerative enteritis.


Effect of a 22-day space flight on the lymphoid organs of rats. The effect of a 22-d space flight on the lymphoid organs of rats has been investigated. It has been shown that the flight leads to hypoplasia of lymphoid organs, the spleen and thymus weight decreasing very noticeably. Histological, morphometric, and cytological examinations have demonstrated that hypoplasia of the spleen occurs due to a reduction of the number of lymphocytes and erythroid cells and hypoplasia of the thymus and lymph nodes due to a decrease of the lymphocyte number. Changes found in the lymphoid organs of the flight rats are reversible and the structure of lymphoid organs recovers 27 d postflight. Pathogenetic mechanisms of the changes developing in lymphoid organs of rats under the influence of space flight are discussed. The animal data are compared with the results of postflight medical examinations of astronauts.


Microscopic lesions suggestive of Marek's disease in a Black Francolin (Francolinus f. francolinus). Microscopic lesions suggestive of Marek's disease were found in tissues from the exotic game bird Black Francolin (Francolinus f. francolinus). These lesions consisted of a solitary spherical mass near the syrinx, histologically composed of sheets of small pleomorphic lymphocytes and a few plasma cells. Lymphocytic cell infiltrates were also seen microscopically in cuffs around vessels of the brain, in the sciatic nerve, and in several visceral organs.


Indirect evidence for arterial chemoreceptor reflex facilitation by face immersion in man. It has been demonstrated that the usual diving bradycardia can be greatly intensified when face immersion is superimposed on a state of apneic exercise. This intensification is neither due to chemoreceptor stimulation, or to face immersion per se. It is concluded that the intensification is caused by chemoreceptor reflex facilitation, due to stimulation of trigeminal receptors in the face.


Water exchange in rats exposed to cold, hypoxia, and both combined. Male rats were exposed chronically to cold (5 degrees C air), hypoxia (12% oxygen in nitrogen), and both combined. Intake of water and food, as well as urinary excretion, were measured during both a 5-d pretreatment control period and throughout the first 3 weeks of the treatment period. Regression analysis of water intake on urine output revealed that, at a given water intake, all three treated groups excreted significantly more urine than controls. No significant differences occurred among treated groups. Serum osmolalities of all three treated groups, measured at the end of the 48-d treatment period, were elevated significantly above the level of the control group. All treated groups also manifested a thirst immediately following return to control environment (26 degrees C, 20.9% oxygen). Water intakes of all three treated groups were significantly greater than that of the control group during the first 2 h after return to control environment. Thus, the three treated groups appeared to be dehydrated relative to the control group. The results further suggest that the effect of combined cold (5 degrees C) and hypoxia (12% oxygen) on water exchange is not a summation of that occurring separately during cold and hypoxia. The factors inducing dehydration in cold and hypoxia are apparently related to increased evaporative water loss and to alterations in thirst and renal mechanisms.


Effects of mevinphos (Phosdrin) on unit discharge patterns in avian hippocampus. Low doses of the acetylcholinesterase inhibitors, mevinphos and physostigmine, reduce hippocampal inhibitory phenomena, measured in terms of the duration of the poststimulus inhibitory pause seen in individual hippocampal neurones in the pigeon. The cholinergic antagonist, atropine, increased hippocampal inhibition. At near threshold doses, mevinphos could, in part, reverse atropine effects. At higher doses, mevinphos synergized with atropine. In the discussion, it is suggested that any organophosphate or carbamate pesticide and its antidote, atropine, may alter "attention" or "short-term memory" through effects on hippocampus at doses too low to induce grossly detectable peripheral symptomatology. Extreme caution in the use or handling of these compounds by aerial applicators is urged. Since the effects of atropine and mevinphos can synergize, the use of atropine to permit poisoned applicators to resume activity is questioned.


An occurrence of avian influenza virus infection in laying chickens. The isolation of avian influenza virus from chickens is reported for the first time in the United States since the fowl plague outbreak of 1929. The type-A virus was isolated from commercial Leghorn laying hens between 54 and 55 weeks old and involved three different farms in north-central Alabama. These flocks experienced up to 69% mortality and a severe decrease in egg production within a 14-day period.


Paralysis in chickens caused by larvae of the poultry tick, Argas persicus. White Leghorn pullets 20 weeks old submitted to the diagnostic laboratory were found heavily infested with the larval stage of the poultry tick, Argas persicus. The birds were severely depressed and recumbent. The signs were quickly reversed when the tick larvae were removed. The rapid rate of recovery and negative results in detailed diagnostic procedures suggested that the tick larvae caused the paralysis.


Use of H2 as an inert gas during diving: pulmonary function during H2-O2 breathing at 7.06 ATA. A review of the characteristics of hydrogen as an inert gas for use in diving is presented, with special emphasis on the extension of the respiratory limitation in diving by use of this least dense of all gases. Forced vital capacity, FEV1, FEV2, PEFR, PIFR, and MVV were measured on groups of subjects using the following gas mixtures, all at 7.06 ATA: four subjects breathing 97% H2-3% O2, two subjects breathing 97% He-3% O2, and two subjects using 97% N2-3% O2. The MVV while breathing H2-O2 at 7.06 ATA was 14% higher than with air at the surface, and was improved 40% compared with He-O2 and 171% when compared with N2-O2 at 7.06 ATA. Similar findings were obtained for FEV1, FEV2, PEFR, and PIFR. The values in this study for the relationship of relative gas density (rho) to flow are rho-0.41 for MVV, rho-0.44 for PEFR, and rho-0.45 for PIFR (method of Wood and Bryan).


Effects of organophosphate pesticides and other drugs on subcortical mechanisms of visual integration. Atropine, scopolamine, mevinphos, and eserine selectively block directional sensitivity of visual integrative neurones in the thalamus. Cholinergic drugs that do not penetrate the blood-brain barrier are without effect. The neurones studied are important links in reflex brain systems controlling visual attention and eye movements. The results suggest that any cholinergic drug that can get into the brain will disturb visual functions. Since the changes are qualitative and the system is reflex, the affected individual may be unaware of dysfunction. The resultant dangers to aerial applicator personnel are discussed, particularly with respect to atropine, which is necessary in the therapy of organophosphate and carbamate poisoning but is potentially harmful if self-administered for either pro-phylaxis or treatment.


Hypoxia and auditory thresholds.

Hypoxia and auditory thresholds. This paper reports the effects of hypoxia on hearing. Pure tone hearing and speech discrimination were tested at ground level and during hypoxic states at simulated altitudes of 4,600 m (15,000 ft) and 6,100 m (20,000 ft) in a high-altitude chamber. Pure tone hearing was not significantly altered during hypoxia produced by this method. Speech discrimination showed alterations, possibly due to central nervous system hypoxia. It was concluded that hypoxia does not cause significant deterioration of hearing for pure tones.


Ineffectiveness of heparin treatment in burn shock in the guinea pig. The cardiovascular and metabolic responses during burn shock were characterized in 10 guinea pigs burned to the xyphoid process for 3 s in boiling water. This produced a burn of approximately 70% of the body surface. Their responses were compared to the values obtained at corresponding times in a group of unburned controls (n=10). The effect of Heparin treatment on burn shock was evaluated in another group (n=8) of guinea pigs burned to the xyphoid process and injected subcutaneously with 50,000 U Heparin/kg immediately after being burned. In the burned, untreated (BUT) animals, cardiac output was reduced more than 50% at 15 mins post-burn, and cardiac output remained depressed for the  next 8 h. Mean arterial blood pressure was initially maintained in the BUT animals, but started to fall after 3 h. Heart rate, oxygen consumption and core temperature all decreased progressively in the BUT group. Hemoconcentration was evident in the BUT animals, and there was an elevation in the post-burn glucose and lactate levels, a decrease in pH, and no change in free fatty acids. Heparin treatment did not significantly modify 24-h survival, and the post-burn cardiovascular responses of the Heparin-treated animals were similar to those of the BUT animals. Metabolically, the Heparin-treated animals had a significant elevation in free fatty acids post-burn, but otherwise closely resembled the BUT animals.


Biochemistry and hematology at decompression sickness: a case report. A 24-year-old hospital corpsman, a volunteer in a series of dry chamber air dives to a simulated pressure equivalent to 188 FSWG (57.3 MSWG), developed left knee pain shortly after standard decompression. A tentative diagnosis of decompression sickness was made and recompression therapy was initiated with alleviation of pain occurring at 60 FSWG (18.3 MSWG). A U.S. Navy Treatment Table "5 (oxygen breathing) regimen was then selected and completed uneventfully. The subject had been undergoing biomedical evaluation for several days prior to diving; thus, a clinically diagnosed case of dysbarism with subsequent treatment was available for study. This individual was then monitored for a 10-d period. The acute phase of decompression sickness was characterized by a marked shortening of clotting time and a thrombocytopenia with accompanying increased platelet aggregates. The recovery phase was categorized by a variety of hematological and bio-chemical changes. Hemodilution, an elevated megathrombocyte index, and a tendency toward eosinopenia were evident for most of the 10-d observation period. Other persistent alterations detected during this period included a relative hyperglycemia, depressed urine Na+/K+, and increased ketosteroid excretion. These observations indicate that abatement of pain after treatment of dysbarism can be followed by the onset of a variety of biochemical and hematological changes. Moreover, complete recovery may require upwards of 10 d.


Five-year study of emergency aeromedical evacuation in the United States. During the time period, 1 July 1969-30 June 1974, a total of 7056 patients were moved on the C-9A Nightingale on an "urgent" or "priority" basis. In support of the request for urgent airlift, an average of 21 C-9A aircraft were launched monthly. The domestic aeromedical evacuation missions were highly flexible and productive, yet inexpensive when compared with other means of moving patients. A means for determining precedence for the pickup and movement of patients is essential for an aeromedical evacuation system. When the patient is properly evaluated and the urgency for flight movement determined, unnecessary, costly, hazardous, or special flights are avoided. More than 50% of the "urgent" patients airlifted during this 5-year span originated in the central part of the United States. The Northeast and Far West were each responsible for less than 10% of the patients requiring urgent evacuation over the same period. More than 50% of the urgent patients moved were in the categories of newborn complications, burns, and neurological problems. During this period, no patient was moved on an urgent basis for a psychiatric problem--aeromedical evacuation simply becomes a very effective tool in ensuring complete health care for seriously ill patients.


Technique for electrocardiographic monitoring of working divers. An improved technique to record high-equality electrocardiographic (ECG) signals on the surface, from immersed humans during rest and exercise, in both normothermic and hypothermic exposures, has been devised. Recorded tracings were adequate for research purposes. Waveform signals obtained allow accurate continuous monitoring as well. The best recordings resulted from proper selection of electrode placement sites, careful preparation of the skin, and diligent protection of the skin-electrode interface. The resulting signals recorded from male divers working in 3.05 m (10 ft) of water contained very little artifact or shift in baseline of the ECG tracing. Post-dive examination of the placement sites showed neither separation of ECG electrodes from the skin nor intrusion of water between the electrode and skin surface. The relationship of the new ECG recording technique to a previously described system for acquiring physiologic data is described.


Physiologic and anti-G suit performance data from YF-16 flight tests. Biomedical data were collected during high-G portions of 11 YF-16 test flights. Test pilots monitored revealed increased respiratory rate and volume, decreased tidal volume, and increased heart rate at higher G levels, with one pilot exhibiting various cardiac arrhythmias. Anti-G suit inflation and pressurization lags varied inversely with G-onset rate, and suit pressurization slope was near the design value.


Influence of tachycardia on regional myocardial flow in chronic experimental coronary occlusion. The influences of tachycardia on regional myocardial flow was studied in normal dogs and in dogs with chronic coronary artery occlusions. Coronary vasodilation was induced by coronary occlusion and subsequent release, i.e. by reactive hyperemia. Local myocardial blood flow was determined with the tracer microspheres technique. In normal hearts atrial pacing produced a slight but significant increase in coronary resistance in the subendocardial layers of the left ventricle. The coronary resistance of the subepicardium remained unaffected. In the right ventricle atrial pacing had no influence on the resistance to flow. In hearts with multiple coronary occlusions tachycardia-induced changes of coronary resistance were more pronounced. In the collateral dependent subendocardium coronary resistance increased from 0.4-2.2 resistance units when the heart rate was raised to 200 beats/min. Perfusion of the right ventricular myocardium became also rate-dependent when the right coronary artery was chronically occluded. We conclude that regional perfusion dependes upon the relationship between the effective perfusion pressure, which is reduced in chronic coronary occlusion, and the integral of effective tissue pressure, which is increased with tachycardia. The results cannot be explained by assuming excessive O2-demand but rather by a rate-induced lowered O2-supply.


Determination of arterial input impedance spectra from non-invasively recorded pulses. The frequency spectra of modulus and phase of the input impedance (Zin) of large human arteries (abdominal aorta, femoral and subclavian arteries) were computed from transcutaneously recorded, uncalibrated pressure and flow pulses picked up as sphygmograms and Doppler flow velocity pulses, respectively. Since these pulses cannot be calibrated, the modulus (Zin) of the input impedance is calculated in relative units; its spectrum, however, is not influenced by this fact. A modification of the computing procedure makes it possible to determine approximately quasi-continuous frequency spectra of Zin from natural pressure and flow pulses which may be regarded as periodic functions. This is the prerequisite for a detailed analysis of the wave transmission properties of the arterial bed which manifest themselves of the input impedance. For this purpose the peripheral reflection site was moved in a proximal direction by bilateral occlusion of limb arteries. This was done by inflating cuffs placed symmetrically on both sides around the upper or lower parts of the respective limbs. When the occluding cuffs were placed around both lower legs or both thighs, the shortening of the arterial wave transmission line resulted in a marked shift of the first maximum of Zin to higher frequencies in the spectrum of Zin of the abdominal aorta and femoral artery. Bilateral occlusion of the arteries of the forearms or upper arms, however, did not have any measurable influence on Zin of the subclavian artery. Theoretical considerations show that this difference in behaviour of the several parts of the arterial system may be attributed to the varying extent of their inhomogeneity.


The influence of glycerol on the Ca flux in the isolated perfused rat heart. Perfusion of the isolated rat heart with a fluid containing 800mM glycerol in addition to its normal constituents causes a contraction height decrease of about 50%. A change to normal perfusion fluid causes a period of contracture to occur. After this period the heart is perfectly viable. Mechanical and osmotic effects could be ruled out as possible causes. No gross disturbances were seen in the electron micrographs. An effect on intermediary metabolism is equally unlikely. Presumably, we must seek the explanation in a direct effect of the glycerol on the Ca++ fluxes across the cellular and intracellular membranes.


The role of myocardial edema in the left ventricular diastolic stiffness. It has been shown that simultaneous administration of norepinephrine (10mug/kg/min) and drotaverine (200 mug/kg/min) does induce interstitial myocardial edema which tends to increase left ventricular diastolic stiffness. These results suggest that in myocardial ischaemia temporary increase of left ventricular diastolic stiffness may be caused by interstitial edema.


Hemodynamics and myocardial electrolyte (k+/na+) metabolism early in hemorrhagic shock during asphyxia. In tests on guinea pig hearts in situ asphyxia tolerance was found to be increased early in hemorragic shock four times control value. These results are suggestive of an energy saving mechanism in shock whereby the heart is not damaged out metabolically relieved. Myocardial analyses showed that, owing to shock-related cardiac relief, under a simultaneous asphyctic stress the intracellular potassium stock decreases later and markedly less.


[Effects of coronary stenosis and mean aortic pressure on coronary blood flow, poststenotic coronary pressure, and reactive hyperemia]. Six dogs were subjected to an acute stenosis of the left  anterior descending coronary artery. The mean aortic pressure was fixed with a windkessel and an occluder on four different levels. A significant decrease of coronary blood flow and poststenotic coronary pressure was closely related to the level of mean aortic pressure. With lower aortic pressure the decrease occurred earlier than with higher aortic pressure. A 50% stenosis did not significantly influence coronary flow and poststenotic coronary pressure. A 90% stenosis resulted in decrease below 10% of control. In a range of aortic pressure between 60 and 140 mm Hg reactive hyperemia was significantly diminished at a 60% stenosis. Reactive hyperemia was completely abolished when coronary stenosis was 90%.


[Recording of ventricular pressure by conventional catheter manometer systems. I. Minimal requirements of blood pressure recording systems and estimation of frequency response characteristics]. Parallel recordings of pressure pulses by conventional catheter manometer systems and catheter tip manometer demonstrate severe errors in the peak velocity of pressure rise estimated by conventional systems. This fact is due to inadequate dynamic response characteristics of conventional systems in relation to the frequency content of pressure curves. During cardiac rest the error in dp/dt max is less than 10% if the frequency response of the recording system is uniform up to 10 Hz, the corresponding value under maximal cardiac stimulation is about 40 Hz. This is equal to the first 10 harmonics of heart rate. The examination of left and right ventricular pressure curves leads to similar results. The experimental determination of dynamic response characteristics of cathermanometer systems requires a test system producing suitable sinus or step functions, parallel high fidelity recording of pressure functions to be recommended. A simple test station is described. Examinations of temperature influence on catheter material and resulting changes in dynamic response characteristics were carried out. The incubation of catheters at the temperature of 37 degrees C is indispensable. A new diagram for simplifying the interpretation of results is described. Other publications are discussed in viewpoint of employed techniques and representation of results.


Accumulation and turnover of the classical Folch-Lees proteolipid proteins in developing and adult rat brain. The turnover of classical Folch-Lees proteolipid proteins was studied after administration of [2,3-3H]tryptophan to both developing and adult rat brain. The animals were killed from 2h to 250 days after subcutaneous injections of [3H]tryptophan. The measured specific radioactivity in developing brain attained maximum value 24h after the administration of label, whereas the total radioactivity per brain reached a maximum 21 days after injection. The half-life of proteolipid protein from the measured specific radioactivity was 7-20 days, depending on the time-points used for the calculation, whereas calculation from total radioactivity between 28-77 and 91-257 days gave half-lives of 35-40 and 188 days respectively. In contrast, in animals injected at 40 days of age, the half-life from the whole-brain-radioactivity data was 188 days. The problem of the recycling of radioactivity for the synthesis of myelin proteins from either a general or a discrete amino acid pool is discussed.


The influence of adenine nucleotides and oxidizable substrates on triethyltin-mediated chloride uptake by rat liver mitochondria in potassium chloride media. In a 100 mM-KCl medium, pH 6.8, containing ATP increasing concentrations of triethyltin cause an uptake of Cl- into mitochondria with a maximum at 1 muM. This can be inhibited by atractylate or oligomycin, but is virtually unaffected by the presence of rotenone. When the medium contains substrate (pyruvate, beta-hydroxybutyrate or succinate), both in the presence and absence of adenine nucleotides, Cl- uptake is greater with a maximum at 1-10 muM-triethyltin. If substrate oxidation is blocked by respiratory-chain inhibitors the Cl- uptake mediated by triethyltin is inhibited except in the media containing ATP, when the characteristics of Cl- uptake similar to that found in the medium containing ATP alone are observed. Under all conditions tested Cl- uptake is decreased by the presence of 2,4-dinitrophenol. It is concluded that energy from either the oxidation of substrate or the hydrolysis of ATP is associated with the generation of sufficient OH- to enable the triethyltin-mediated Cl-/OH- exchange to occur under the metabolic conditions relevant to this action of triethyltin.


A stopped-flow dual-wavelength spectrophotometer suitable for the study of respiratory chains. The requirements for a dual-wavelength stopped-flow spectrophotometer to be suitable for studying limited quantities of respiratory-chain preparations are described. They can be met by a design using mainly commercially available components. The constructed apparatus has a dead-time of approx. 2.6 ms, a mixing ratio of 17:1, and a minimal requirement for 0.5 ml of mixed reactants per flow.


Effect of hyperphenylalaninaemia on lipid synthesis from ketone bodies by rat brain. The effect of hyperphenylalaninaemia on the metabolism of ketone bodies in vivo and in vitro by developing rat brain was investigated. The incorporation in vivo of [14C]acetoacetate into cerebral lipids was decreased by both chronic (for 3 days) and acute (for 6h) hyperphenylalaninaemia induced by injecting phenylalanine into 1-week-old rats. In studies in vitro it was observed that the incorporation of the radioactivity from [14C]acetoacetate and 3-hydroxy[14C]butyrate into cerebral lipids was inhibited by phenyl-pyruvate, but not by phenylalanine. Phenylpyruvate also inhibited the incorporation of 3H from 3H2O into lipids by brain slices metabolizing either 3-hydroxybutyrate or acetoacetate in the presence of glucose. These findings suggest that the decrease in the incorporation in vivo of [14C]acetoacetate into cerebral lipids in hyperphenylalaninaemic rats is most likely caused by phenylpyruvate and not by phenylalanine. Phenylpyruvate as well as phenylalanine had no inhibitory effects on ketone-body-catabolizing enzymes, namely 3-hydroxybutyrate dehydrogenase, 3-oxo acid CoA-transferase and acetoacetyl-CoA thiolase, in rat brain. Phenylpyruvate but not phenylalanine inhibited the activity of the 2-oxoglutarate dehydrogenase complex from rat and human brain. These findings suggest that the metabolism of ketone bodies is impaired in brains of untreated phenylketonuric patients, and in turn may contribute to the diminution of mental development and function associated with phenylketonuria.


Insulin-like actions of nickel and other transition-metal ions in rat fat-cells. NiC12 (1-6mM) decreased adrenaline and glucagon-stimulated lipolysis in rat fat-cells, and also considerably stimulated [U-14C]glucose incorporation into fat-cell lipids. 2. These insulin-like effects were also observed with CuCl, CuCl2, CoCl2 and (to a lesser extent) with MnCl2. 3. NiCl2 was less effective in mimicking insulin effects on [U-14C]fructose metabolism than on glucose utilization. 4. It is tentatively suggested that these transition-metal ions may mimic actions of insulin at the fat-cell plasma membrane which decrease lipolysis and stimulate glucose transport, but do not mimic certain other effects of the hormone on intracellular metabolic processes. 5. These results are discussed with reference to suggestions that redistributions of cellular Ca2+ are associated with insulin action in fat-cells.


Nature of the facilitated messenger ribonucleic acid transport from isolated nuclei. Cytoplasmic macromolecules were previously identified which regulate both qualitatively and quantitatively the release of messenger-like RNA from isolated nuclei. These macromolecules are now shown to be denatured at 45-50 degrees C and their synthesis is sensitive to pactamycin or cycloheximide. The putative regulatory proteins are essentially quantitatively precipitated with high specificity from the cytosol by streptomycin at a concentration 10-fold higher than that used to precipitate RNA. The nuclear concentration-dependence of RNA transport from successive samples of nuclei strongly suggests that the regulatory factors are recycled. Quantitative changes in the sequences transported at various dilutions of the cytosol suggest that not all the different classes of the putative regulatory macromolecules are present in an effective concentration at any one dilution.


Deoxycytidine transport and pyrimidine deoxynucleotide metabolism in phytohaemagglutinin-stimulated pig lymphocytes. Increased entry of deoxy[3H]cytidine begins at about 12h after addition of phytohaemagglutinin to peripheral pig lymphocyte cultures, and is accompanied by a parallel stimulation of deoxycytidine kinase up to the beginning of DNA synthesis at 24h. The increased deoxycytidine uptake is characterized by an increase in Vmax. without alteration of the apparent Km (0.7 +/- 0.11 muM). Although the entries of both nucleosides are promoted at the same time, the stimulation of deoxycytidine uptake is less than that of thymidine, and the two nucleosides are transported by separate systems. In addition to deoxycytidien kinase, the synthesis of deoxycytidylate deaminase and thymidylate synthetase are stimulated after addition of phytohaemagglutinin, but to a lesser extent than that of thymidine kinase. The importance of the latter enzyme in forming dTMP, and of thymidylate kinase in providing dTTP, is discussed.


Preparation and properties of mitochondria derived from synaptosomes. A method has been developed whereby a fraction of rat brain mitochondria (synaptic mitochondria) was isolated from synaptosomes. This brain mitochondrial fraction was compared with the fraction of "free" brain mitochondria (non-synaptic) isolated by the method of Clark & Nicklas (1970). (J. Biol. Chem. 245, 4724-4731). Both mitochondrial fractions are shown to be relatively pure, metabolically active and well coupled. 2. The oxidation of a number of substrates by synaptic and non-synaptic mitochondria was studied and compared. Of the substrates studied, pyruvate plus malate was oxidized most rapidly by both mitochondrial populations. However, the non-synaptic mitochondria oxidized glutamate plus malate almost twice as rapidly as the synaptic mitochondria. 3. The activities of certain tricarboxylic acid-cycle and related enzymes in synaptic and non-synaptic mitochondria were determined. Citrate synthase (EC 4.1.3.7), isocitrate dehydrogenase (EC 1.1.1.41) and malate dehydrogenase (EC 1.1.1.37) activities were similar in both fractions, but pyruvate dehydrogenase (EC 1.2.4.1) activity in non-synaptic mitochondria was higher than in synaptic mitochondria and glutamate dehydrogenase (EC 1.4.1.3) activity in non-synaptic mitochondria was lower than that in synaptic mitochondria. 4. Comparison of synaptic and non-synaptic mitochondria by rate-zonal separation confirmed the distinct identity of the two mitochondrial populations. The non-synaptic mitochondria had higher buoyant density and evidence was obtained to suggest that the synaptic mitochondria might be heterogeneous. 5. The results are also discussed in the light of the suggested connection between the heterogeneity of brain mitochondria and metabolic compartmentation.


Growth hormone and drug metabolism. Acute effects on microsomal mixed-function oxidase activities in rat liver. Adult male rats were subjected either to sham operation or to hypophysectomy and adrenalectomy and maintained for a total of 10 days before treatment with growth hormone. Results of the early effects of growth hormone on the activities of the mixed-function oxidases in rat liver over a 96h period after growth-hormone treatment are presented. 2. Hypophysectomy and adrenalectomy result in decreased body and liver weight and decreased drug metabolism (mixed-function oxidases). Concentrations of electron-transport-system components are also decreased. 3. In the hypophysectomized/adrenalectomized rats, growth hormone decreases the activities of the liver mixed-function oxidases and the cytochrome P-450 and cytochrome c reductases, as well as decreasing the concentration of cytochrome P-450 compared with that of control rats. Similar but less dramatic results are obtained with sham-operated rats. 4. It is concluded that whereas growth hormone enhances liver growth, including induction of many enzyme activities, it results in a decrease in mixed-function oxidase activity. Apparently, mixed-function oxidase activity decreases in liver when growth (mitogenesis) increases.


A deoxyribonucleic acid-replication intermediate in the growing mosquito. In previous experiments on growth and aging in the yellow-fever mosquito, Aedes aegypti, a low mol. wt. (500000) DNA species was found in the supernatant fraction after ultracentrifugation of homogenates of rapidly-growing larvae. This DNA species, "sDNA", constituted 30-40% of total DNA in 2-4-day-old larvae, but was less than 5% in older larvae, pupae and adults. We have now isolated and characterized sDNA and initiated experiments to determine its metabolic role. Isolated sDNA has the same physical and chemical characteristics as bulk DNA, "pDNA", and differs only in size. In CsCl isopycnic centrifugation the buoyant densities of sDNA and pDNA were 1.700 and 1.697 g/cm3 respectively. The "melting" temperature of both DNA species was 84 degrees C. Base compositions calculated from these data and other methods were 38.9 mol% of guanine-plus-cytosine for sDNA, and 38.5 for pDNA. Also, the size of newly-synthesized DNA was investigated by pulse-labelling and pulse-chase experiments. In neutral sucrose gradients the labelled DNA component after a 2h pulse had a sedimentation coefficient of about 8S, but after a 4h pulse sedimented in a broad band from 10-19S. In alkaline sucrose gradients a single peak around 7S was observed for pulse times up to 4h. After a 6h pulse and a 1 day "chase", labelled DNA species had sedimentation coefficients ranging from 10-15S in alkaline sucrose, and after a 2-day chase the values were 17-31S, similar to those of pDNA under alkaline conditions. These results suggest that sDNA represents an intermediate form in the replication of DNA in mosquito larvae.


The biosynthesis of deoxyribonucleic acid during the life-span of the mosquito. Previous results from this laboratory [Kao et al, (1976) Biochem. J. 154, 471-480] demonstrated that a low-molecular-weight DNA species, "sDNA", present in high concentrations during rapid larval growth of the yellow-fever mosquito, Aedes aegypti, may be an intermediate in DNA replication. We have now determined the life-span profiles of synthetic rates and the steady-state contents of sDNA and total DNA by radiometric and biochemical procedures and by using mosquitoes grown and maintained under defined and controlled conditions, including axenic culture and synchronization of stages. 2. Our results showed exponential increases in DNA contents and synthetic rates which paralleled the changes in weight during larval growth. Of special importance was the finding that in rapidly-growing larvae and newly-emerged adult mosquitoes high contents and rates of synthesis of sDNA were correlated with increases in total DNA/organism, which suggests that sDNA content may be an index of DNA replication. In senescent mosquitos a twofold increase in the synthetic rate of bulk DNA ("pDNA") without an increase in sDNA may reflect repair synthesis. 3. The significance of this investigation is that it may be the first quantitative and systematic description of the synthetic rates and contents of both DNA-replication intermediates and total DNA in an axenic, eukaryotic organism rather than a specific cell type. Equally important is that these findings describe DNA changes during growth and also during aging through senescence in an age-characterized organism.


Similarities in the polypeptide composition of glyoxysomal and endoplasmic-reticulum membranes from castor-bean endosperm. Microsomal fractions, glyoxysomes and mitochondria were isolated from homogenates of germinating castor-bean (Ricinus communis) endosperm by sucrose-density-gradient centrifugation. Washed membrane preparations from these cellular fractions were examined by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. At corresponding developmental stages the endoplasmic-reticulum and glyoxysomal membranes were strikingly similar in polypeptide composition, at least 16 polypeptides being present in membranes isolated from 3-day-old tissue. Supplying [35S]methionine to intact endosperm tissue resulted in the labelling of all membrane polypeptides, the specific radioactivity in the endoplasmic reticulum being greater than for equivalent polypeptides of the glyoxysomal membrane. Washing these membranes with sodium deoxycholate solution extensively solubilized protein components, with the exception of a predominant polypeptide of mol.wt. 55000. Mitochondrial membrane preparations differed from those of the endoplasmic reticulum and glyoxysomes in polypeptide molecular-weight distribution and the [35S]methionine-labelling pattern. The similarity in polypeptide composition between endoplasmic-reticulum and glyoxysomal membranes is discussed in relation to glyoxysome biogenesis.


The cellular origin of glyoxysomal proteins in germinating castor-bean endosperm. The capacity of castor-bean endosperm tissue to incorporate [35S]methionine into proteins of the total particulate fraction increased during the first 3 days of germination and subsequently declined. At the onset of germination 66% of the incorporated 35S was found in the separated endoplasmic-reticulum fraction, with the remainder in mitochondria, whereas at later developmental stages an increasing proportion of 35S was recovered in glyoxysomes. The kinetics of [35S]methionine incorporation into the major organelle fractions of 3-day-old endosperm tissue showed that the endoplasmic reticulum was immediately labelled, whereas a lag period preceded the labelling of mitochondria and glyoxysomes. When kinetic experiments were interrupted by the addition of an excess of unlabelled methionine, incorporation of [35S]methionine into the endoplasmic reticulum rapidly ceased, but incorporation into mitochondia and glyoxysomes continued for a further 1h. Examination of isolated organelle membranes during this period showed that the addition of unlabelled methionine resulted in a stimulated incorporation of [35S]no methionine into the endoplasmic-reticulum membrane for 30 min, after which time the 35S content of this fraction declined, whereas that of the glyoxysomal membranes continued to increase slowly. The 35S-labelling kinetics of organelles and fractions derived therefrom are discussed in relation to the role of the endoplasmic reticulum in protein synthesis during glyoxysome biogenesis.


Identification of bile acids in the serum and urine in cholestasis. Evidence for 6alpha-hydroxylation of bile acids in man. In this qualitative study of the pattern of bile acid excretion in cholestasis, methods are described for the isolation of bile acids from large volumes of urine and plasma. The bile acids were subjected to a group separation and identified by combined gas chromatography-mass spectrometry. The techniques were developed to allow identification of the minor components of the bile acid mixture. Four bile acids that have not previously been described in human urine and plasma were detected, namely 3beta, 7alpha-dihydroxy-5beta-cholan-24-oic acid, 3alpha, 6alpha-dihydroxy-5beta-cholan-24-oic acid (hyodeoxycholic acid), 3alpha, 6alpha, 7alpha-trihydroxy-5beta-cholan-24-oic acid (hyocholic acid) and 3alpha, 7beta, 12alpha-trihydroxy-5beta-cholan-24-oic acid. In addition three C27 steroids were found; 26-hydroxycholesterol and a trihydroxy cholestane, probably 5 beta-cholestane-3alpha, 7alpha, 26-triol were found in the sulphate fraction of plasma and urine. In the plasma sample, a sulphate conjugate of 24-hydroxycholesterol was found. The presence of these compounds probably reflects the existence of further pathways for bile acid metabolism. It is not yet known whether this is a consequence of the cholestasis or whether they are also present in normal man, at much lower concentrations.


The metabolism of high-molecular-weight ribonucleic acid including polyadenylated species, in the developing rat brain. High-molecular-weight RNA was isolated from rat brain at various times after the intracranial administration of [32P]Pi. The synthesis of 28S and 18S rRNA could be detected within 1h of the injection of the radioactive precursor and appeared to be more pronounced, relative to other high-molecular-weight RNA, in the brains of older rats compared with those of newborn rats. Polyadenylated RNA, representing most mRNA and their precursors, was isolated by chromatography on oligo(dT)-cellulose. The contribution of this polyadenylated RNA to total RNA synthesis was investigated in the cerebral cortex and the phylogenetically older brain stem at different stages in the development of the rats by using a 5h period of labelling as an arbitrary index of transcription. In the brain stem the proportion of labelled polyadenylated RNA comprised 27-30% of the total RNA. The corresponding values for the cortex decreased from 34% in newborn rats to 23% in 40-150-day-old rats. These data indicated that proportionately more polyadenylated RNA is synthesized in the cortex of the newborn than in the adult rat and that there is a progressive decrease in the synthesis of polyadenylated RNA relative to rRNA during development.