A method for training and evaluating the reception of ongoing speech.

The "tracking procedure" is a method to train and evaluate the reception of ongoing speech. A talker and a receiver engage in a dialogue for a designated period of time in which the receiver reports his perception of successive segments of read text and is corrected by the talker until the text is repeated verbatim. Performance is measured in number of words of text repeated correctly per unit of time. The procedure is illustrated by its application to a project for training and evaluating use of a vibrotacile-electrotactile aid to lipreading. Differences between experimental conditions are described over time in terms of absolute words per minute, increment of aided over unaided words-per-minute scores, and percent of normal listening rate. Data from identification tests with syllables, words, and sentences are also presented. Tracking is suggested as an additional procedure for communication training in aural rehabilitation or classroom setting, and for evaluation of other communication systems.


Auditory responses in cats produced by pulsed ultrasound.

Auditory-nerve responses and cochlear microphonics are produced in cats by pulsed 5-MHz ultrasonic energy from a transducer placed against the dura mater. The pulses must be relatively intense (approximately 30 W/cm2) to produce a response, but can be sufficiently brief (less than 70 microsecond) that the brain tissue is not observably heated. The cats apparently respond to radiation pressure transients accompanying the absorption of the ultrasound in the brain tissue. Both the amplitude and latency of the N1 neural responses to the ultrasound can be matched to those produced by relatively weak tone pips or clicks from an external source. The cochlear microphonic (CM) produced by a pulse shows a prominent ringing at 5-10 kHz in different cats; the amplitued of the N1 response exhibits broad maximum, for constant amplitude pulses, a pulse widths of 20-60 microsecond. This variation of N1 response amplitude with pulse width is similar to that of a high-pass filter with a cutoff frequency at the dominent frequency of the CM, which is tentatively identified with a ringing frequency of the skull.


Backward masking: detection versus recognition.

The backward detection masking of 10-ms tonal targets by a 150-ms tonal mask was contrasted with the backward recognition masking of the same tones by the same mask. The target-mask interval required for 75% correct performance was about eight times as great in the recognition condition as in the detection condition. Furthermore, a generalized improvement in performance occurred over the initial course of training in both the detection and recognition conditions. In a second experiment it was found that a remote mask produced greater backward recognition masking but less backward detection masking. That these differences were observed with the same subjects, at the same level of training, and with identical stimuli, indicates that procedural differences alone cannot account for the differences between backward detection and recognition masking.


Correlational study of speakers' heights, weights, body surface areas, and speaking fundamental frequencies.

The purpose of this investigation was to determine the relationship among speakers' heights, weights, body surface areas, and speaking fundamental frequencies. The recordings of 30 speakers' readings of a standard prose passage were analyzed by means of the Fundamental Frequency Indicator (FFI) to obtain their speaking fundamental frequency characteristics. The speakers' heights and weights were obtained by means of standard measurement procuedures, and their body surface areas were calculated. Pearson product-moment correlation coefficients, computed separately for men and women, indicated that speakers' heights, weights, and body surface areas were not significantly correlated with their speaking fundamental frequencies; female speakers showed a slight negative correlation while male speakers showed a low, positive trend. Implications of these findings and suggestions for future research are discussed.


Frequency dependence of ultrasonic absorption in mammalian testis.

The earlier report that the frequency dependence of ultrasonic absorption of mammalian testis memicked a single relaxation process is explained as an effect of ultrasonic beam width upon the transient thermoelectric technique. More detailed measurements show that the frequency dependence of the ultrasonic absorption in testis is much the same as the attenuation in other soft tissues, viz., a proportional to f1.1. The earlier finding that testis exhibits an ultrasonic absorption coefficient significantly lower than reported for other tissues is confirmed.


Aging--a jewel in the mosaic of life. 15th Lenna Frances Cooper Memorial Lecture.

It is time to disabuse ourselves of the prevalent negative stereotypes and myths about aging. More people are living to an older age without the handicap of disease--and many of them are living independent, satisfying lives. True, there are old people who are loney, sick, and /or poor, but they are the minority. Nevertheless, they cannot be forgotten. There is an urgency to try to make their lives better. By ridding society of these negative stereotypes, better progress in the field of gerontology can be made. With nutrition  woven so intimately into the fabric of satisfying living, opportunities beckon to the dietitian to provide service to the elderly. Done effectively, such service can add to the quality of life of all older persons, so that the later years can have dignity and meaning and indeed become a jewel in the mosaic of life.


Title VII--Nutrition Program for the Elderly. I. Contribution to one day's dietary intake.

Food records kept by 466 individuals participating in the federally funded Nutrition Program for the Elderly show that those eating at the meal site on the day of the food record consumed more energy, protein, and calcium than non-participants and participants who did not eat there on the day of the record. Dietary ratings, which included eight nutrients and energy, indicated they also had better overall diets than non-participants. Non-participants consumed more iron than participants. The daily intake of all nutrients, except calcium, of those eating at the meal site reflected what was offered. Between 40 and 50 per cent of the total daily intake was consumed at the meal center. Women consumed a significantly greater proportion of their daily intake of most nutrients from the food provided by program than the men. The desirability of providing a high proportion of the recommended allowances for protein and other nutrients through the meal program menus is emphasized. The results of the study demonstrated the importance of nutritionists in administrative roles at the state and area levels in determining the effectiveness of a meal program, since food intake reflected menu planning.


Nutritional knowledge, attitudes, and dietary practices of the elderly.

The nutritional knowledge and attitudes toward food and nutrition of sixty-four non-institutionalized elderly persons were surveyed. Findings were then examined in relation to these individuals' actual dietary behavior, measured as nutrient intakes and the purchase of health foods and vitamin/mineral supplements. On the basis of data from three-day food records per participant from three groups of elderly, it was found that, with the exception of energy and calcium intakes, mean nutrient intakes were satisfactory. Those who ate with others and who consumed more snacks had the most satisfactory diets. Socioeconomic status and nutritional knowledge were the key independent variables. A pattern of attitudes and beliefs, such as a belief that nutrition is important, a tendency to regard food and supplements as medicine, a belief in taking vitamin/mineral supplements, and weight-reducing misconceptions, acted as intervening variables to mediate the link between the indepedent variables and the dependent variables (dietary practices).


Nutritional improvement in Hokkaido orphanage children--1960-1970.

In 1960, a survey showed Japanese orphanage children to be shorter in stature than Japanese children in general. In 1964, food budgets for orphanages were increased and, on Hokkaido, 180 gm. milk per day was made available for each child. In 1968, a further improvement in the diet was made by providing for an egg a day for each child, plus more liberal money allowances. Data from surveys in 1965 and 1970 on food served to these children reflected the improvements, as compared with 1960, Figures on the stature of the orphanage children were also compared. By 1970, the only orphanage children falling below the national mean were the teen-age boys and, to a lesser extent, the adolescent girls. Weight differences in all three surveys were less striking.


A multi-echelon menu item forecasting system for hospitals.

A multi-echelon system was designed to generate statistical forecasts of menu-item demand in hospitals from one- through twenty-eight-day intervals prior to patient meal service. The three interdependent echelons were: (1) Forecasting patient census, (2) estimating diet category census, and (3) calculating menu-item demand. Eighteen weeks of supper data were utilized to analyze diet category distribution patterns and menu-item preferences, to test forecasting models, and to evaluate the performance of the forecasting system. A cost function was used to evaluate the efficiency of the mathematical forecasting system and manual technique over a nine-week period. The cost of menu-item forecast errors resulting from the use of adaptive exponential smoothing and Box-Jenkins formulations was approximately 40 per cent less than costs associated with the manual system.


Visual acuity in hard and soft contact lens wearers: a comparison.

Visual acuity measurements with spectacles, with hard contact lenses and with hard contact lenses plus overrefraction were made on 75 eyes. Similar data was taken on 75 eyes wearing soft contact lenses. In each case, some eyes showed a decrease in visual acuity with contact lenses but the soft lenses wearers showed a greater percentage of eyes with visual acuity decrease.


Soft lens cleaners: their effectiveness in removing depostis.

The useful life of a hydrophilic lens is often reduced by deposits forming on or within the polymeric structure of the lens. To eliminate this problem, several cleaning agents have been formulated to prevent and/or remove these deposits. The efficacy of these agents in cleaning heavily deposited lenses is the topic of this investigation.


Reliability and repeatability study of a technique for measuring the center thickness of a hydrogel lens.

Various techniques of measuring the center thickness of hydrogel contact lenses are discussed. A new device called the Bisurfaced Hydrogel Lens Platform (BHLP) is described which in combination with the radiuscope allows for easy measurement of the center thickness of hydrogel lenses. The results of reliability and repeatability studies of this new device are reported which suggest the ability to measure the center thickness of hydrogel lenses within a range of .01 mm.


A minimum clearance molded scleral cosmetic-refractive contact lens.

The author describes the prescribing of a minimum clearance, molded fenestrated cosmetic scleral contact lens with a 2 mm lens in the iris section in front of an optical iridectomy. The lens was designed to improve cosmesis, and to restore a blind eye to 20/90.


The "multi-purge procedure" and its application for hydrophilic lens wearers utilizing preserved solutions.

The multi-purge procedure has been used to remove or dilute preservatives in chemical rinsing, storage or disinfecting solutions for soft lenses. It is used for patients who use preserved solutions and who develop eye reactions to these solutions.


Experience with the lathe cut Bausch & Lomb SOFLENS: Part 1--Clinical study.

This study consists of clinical experience with the recently produced lathe cut Bausch & lomb SOFTLENS. Sixteen patients were fitted with the spin cast and then lathe cut lens. Visual acuities were better with the lathe cut lens. Comfort was good with both lenses. Some degree of circum-corneal injection was noted with the larger lathe cut design.


Contact lenses for the graying American.

The 1960s were the time of civil rights, the 1970s emphasized women's rights. and the 1980s will embrance the rights of the aging. By then, the median age of the U.S. population will be over 30 and the fastest growing segment of the population will be the 24 or 44 year olds, who underpin the nation's economic growth. With fewer children and more working wives, contact lenses are affordable and attractive but these people are becoming presbyopic. Optometrists interested in contact lenses have liked to think of their patients as youthful so the graying of America will bring sweeping changes to the field. Mature patients deserve the improved vision and pleasure they can experience wearing contact lenses.


Utilization of the Hydrocurve soft lens for increasing success in soft lens fitting.

With the Food and Drug Administration approval of the Hydrocurve soft contact lens, previously unsuccessful soft contact lens candidates may now be able to wear a Hydrocurve lens rather than being limited to the new ultrathin "semiflexible" or hard contact lenses as the only viable alternative. The Hydrocurve has proven to be an excellent lens with a potential to greatly increase the percentage of successful soft lens patients for the practitioner. Due to Hydrocurve's extensive flexibility in terms of base curve and diameter it has shown to be quite useful where other lenses have failed due to a lesser variability in parameters.


A clinical study of CAB lens wear.

A clinical study of 100 patients fit with gas permeable contact lenses (cellulose acetate butyrate) reveals a 79% success rate. The authors found good eye physiological response with minimum corneal edema, minimum corneal staining, no increase in follicular hypertrophy and minimum spectacle blur.


Evaluating the effects of wearing contact lenses: morning and afternoon testing.

Corneal steepening and myopic increases are characteristic of diurnal variations which affect habitual wearers of contact lenses. Testing before insertion of lenses and after wearing lenses for 8 hours provided a good indication of the magnitude of diurnal changes in 35 individuals.


Soft lenses to protect the cornea after Fasanella ptosis surgery.

Soft lenses are used continuously for a prolonged period as a corneal protective device following unique under-lid surgery for ptosis correction. Until this procedure was employed, this excellent surgical technique had been all but abandoned.


Refractive amblyopia: a differential diagnosis.

The diagnostic characteristics of refractive amblyopia are discussed and compared to those of strabismic amblyopia. Those characteristics which have appeared in the literature include refractive error type, suppression pattern, fixation type, crowding phenomenon, effect of illumination on visual acuity, color vision and electrodiagnostic tests.


The fixation disparity-heterophoria relationship.

If the heterophoria is the cause of a fixation disparity, then certain conditions can be experimentally observed. An experiment was performed and the conditions previously set forth as indicative of a cause-effect relationship between the heterophoria and fixation disparity were observed.


The regression of hypertensive retinopathy.

The detection of severe hypertensive retinopathy in a relatively symptomless 30-year-old white female contact lens patient is reported. The regression is documented during subsequent antihypertensive therapy. The retinopathy resolved uneventfully despite fluctuating blood pressure.


Vision and sports.

The relationship between optimal visual skills and optimal athletic performance is discussed along with specific examples of how performance can be affected in tennis, basketball, football, baseball, and golf. A step-by-step method is presented to evaluate these specific skills during the optometric evaluation.


Hollenhorst plaques.

Detection of Hollenhorst plaques in the retinal circulation of the asymptomatic patient should be considered to be indicative of atherosclerotic disease. Such patients should be referred for medical evaluation and amelioration of risk factors.


Erickson goniolens system.

The Optometric Research Institute has clinically evaluated the effectiveness and efficiency of the Erickson Goniolens System. Operational procedures and interpreting the results are discussed. Advantages, disadvantages and conclusions are expressed.


The eye--part 2.

Although it is remarkabel how well the sturdy eye is protected against hostile forces, it is still vulnerable. It is precisely because of the specialized nature and complex origin of the eye's structure that it is so vulnerable to a variety of allergic manifestations. Allergy has come to be accepted as a major etiology factor in ocular pathology.


Alcohol and open angle glaucoma--influence on detection, IOP, BP/IOP ratios.

This study was undertaken to determine whether the ingestion of moderate amounts of ethyl alcohol should be contraindicated in the presence of open-angle glaucoma and/or might interfere with glaucoma detection by methods based on measurement of intraocular pressure (IOP) alone or of the ratios, systolic blood pressure and diastolic blood pressure to intraocular pressure, sBP/IOP and dBP/IOP, respectively. Following ingestion of alcohol at the rate of 1 ml/kg body weight, IOP, sBP, and dBP were measured in 73 adult subjects at 15 minute intervals for 90 minutes. Ingestation of alcohol resulted in a reduction of IOP, sBP, and dBP. The ratios sBP/IOP and dBP/IOP showed an increase. This included five subjects with a baseline sBP/IOP of less than 5.75. Results of this study suggest that ingestion of moderate amounts of alcohol will probably reduce IOP in open-angle glaucoma, and need not be contraindicated. On the other hand, consumption of a moderate quantity of alcohol by a subject one to two hours prior to participation in a gluacoma screening program may result in a missed detection by either of the usual criteria of IOP alone or of a BP/IOP ratio.


An overview of visual rehabilitation and training of the low vision patient.

The field of low vision requires a thorough understanding of the many psychologic considerations in visual rehabilitation as well as the current training procedures in the use of distance and near aids. This paper is an overview of these considerations with recommendations for the future.


Residual astigmatism in hard and soft contact lens wearers.

Residual astigmatism in a group of hard contact lens wearers and an equal size group of soft contact lens wearers was compared. Generally, the criteria used were to fit patients with refractive astigmatism greater than 0.75 D with hard lenses and those with refractive astigmatism of 0.25 D or less with soft ones. Those with refractive astigmatism between 0.25 D and 0.75 D were fitted with either modality depending upon other factors. The amount of residual astigmatism in the two groups proved to be nearly equal.


Experience with the lathe cut Bausch & Lomb Soflens: Part II--Power and optics study.

Ten familiar spin cast and ten lathe cut Bausch & Lomb SOFLENS contact lenses were measured as to their power on a lensometer and on an eye. Both quality of the optics and quantitative measurements were considered. Lens flexure and the presence of a fluid lens between the posterior surface of the contact lens and the anterior cornea is indicated for both lenses to explain differences between power of the lens in air and on the eye. The spin cast lens design appears to create a quantitatively larger fluid lens, and one which will add positive optical power to the lens/eye system. Either from this and/or additional factors, the lathe cut lens appears to give improved optical performance both in air and on the eye.


Commercial factor VIII associated hepatitis, 1974-75, in the United Kingdom: a retrospective survey.

A retrospective survey of transfusion hepatitis associated with a brand of commercial Factor VIII was carried out in 24 Haemophilia Centres from January 1974 until December 1975. Of 371 patients who were transfused with this product, and were followed up, 78 cases of hepatitis affecting 66 patients were found (17.7%). Two types of hepatitis were observed: hepatitis B and non-B hepatitis, the latter with an incubation period of between 8 and 60 days. Twelve patients contracted two types of hepatitis, non-B followed by hepatitis B. Only one patient died after contracting hepatitis B. Four of the suspect batches of concentrate were found to be positive for HBsAg by radioimmunoassay. There was evidence that the presence of hepatitis B surface antibody in a patient's serum prior to exposure was associated with immunity to hepatitis B. Evidence was presented suggesting that the non-B hepatitis observed was not due to hepatitis A. The factors affecting the incidence of transfusion hepatitis in haemophiliacs were discussed.


Antibody titres in women six to eight years after the administration of RA2713 and Cendehill rubella vaccines.

Titres of haemagglutination-inhibiting antibody have been measured repeatedly in young women during a period of 6-8 years after the administration of RA27/3 and Cendehill attenuated rubella vaccines. Mean antibody titres were initially 217 after RA27/3 and 159 after Cendehill, but the difference diminished after the first year. Antibody titres were subsequently well maintained in both groups and did not reveal any need for regular revaccination. Mean titres in the Cendehill group were partly maintained by symptomless reinfection which was commoner after Cendehill than after RA27/3. Significant falls in titre were equally common after both vaccines, but low titres of 30 or less were more frequent in subjects who had received Cendehill. Mean neutralizing antibody titres were initially 15.4 after RA27/3 vaccine and 9 after Cendehill. Titres remained higher after RA27/3 for 3 years, but the difference then diminished and became insignificant during the fifth year. Revaccination of women with low antibody titres produced significant increases in 69% of subjects when standard RA27/3 vaccine was used; a special preparation of RA27/3 of higher potency produced a similar number of rises (70%) but elicited higher titres and might occasionally be useful for revaccinating women who are likely to come into contact with rubella. Challenge with RA27/3 vaccine produced weaker responses in women who had experienced natural infection than in those whose antibody was vaccine-induced. Rises in antibody titre after revaccination consisted mainly of IgG, but traces of IgM antibody were detected in one vaccinee who had recently experienced natural reinfection and in 1 woman with naturally acquired antibody who had been challenged with high titre RA27/3 vaccine.


Corynebacterium kutscheri and its alleged avirulent variant in mice.

Corynebacterium kutscheri and its alleged avirulent variant were re-examined in C57Bl/6 and Swiss Lynch mice. It was confirmed that while C57Bl/6 mice were resistant and Swiss Lynch susceptible to C. kutscheri, the alleged atypical variant was avirulent in both mouse strains. However, following immunosuppression of C57Bl/6 mice with hydrocortisone acetate, it was not possible to reactivate latent C. kutscheri or the alleged atypical variant; this was contrary to previous reports. Moreover, sequential hysterectomy derivation over four generations of C57Bl/6 mice did not eliminate their resistance to C. kutscheri compared with conventionally born animals. Vaccination with live attenuated C. kutscheri protected susceptible mice against virulent challenge; vaccination with the alleged atypical variant afforded no such protection. The suggested role of the alleged avirulent variant in resistance to C. kutscheri is challenged and an alternative explanation of such resistance is proposed.


Laboratory evaluation of pyriminyl used as a rodenticide against the lesser bandicoot rat, Bandicota bengalensis.

The properties of pyriminyl (N-3-pyridylmethyl-N'-p-nitrophenyl urea) as a rodenticide against the lesser bandicoot rat (Bandicota bengalensis) in Rangoon, Burma, were investigated in the laboratory. The acute LD 50 and LD 95 dose of orally administered pyriminyl for B. bengalensis were found to be 6.7 mg/kg and 23.0 mg/kg of body weight respectively. When caged bandicoots were given a choice between plain and poisoned baits, the optimum rodenticidal concentration in the bait was found to be 0.25-0.5%. Symptoms of pyriminyl poisoning appear from 1 to 4 h after feeding starts, giving individual animals time to consume from 2 to over 30 LD 50 doses of 0.5% pyriminyl before feeding stops. Deaths occurred from 4 to 96 h after either oral dosing or free-choice feeding. There appeared to be no significant aversion to the poison at 0.25% or 0.5% concentration in foods. The potential hazards and use of pyriminyl as a field bait against populations of B. bengalensis are discussed.


A study of the susceptibility of cattle to oral infection by salmonellas contained in raw sewage sludge.

Raw sewage sludge, containing up to 10(5) naturally occuring salmonellas/1, was included in the diet of one group of cattle at the rate 1 ]/animal/day and in a second group at the rate of 1 ]/animal/week. Sterilized sludge, to which had been added 10(5) S. dublin/litre, was included in the diet of a third group of animals at the rate of 1 ]/animal/day. Salmonellas were isolated from all samples of raw sewage sludge but were not isolated from the faeces or carcasses of animals fed on the sludge. Salmonellas were isolated from the faeces of one animal and the carcasses of two animals fed on sterilized sludge to which S. dublin had been added.


A study of the surface and somatic antigens of Bacteroides fragilis.

Antisera against live cultures of 20 strains of Bacteroides fragilis produced in rabbits agglutinated homologous whole-cell as well as O-antigen suspensions with several cross-reactions. Pure specific antisera were produced by absorbing cross-reacting antigens. O-antisera reacted against O-antigens but failed to do so against most whole-cell suspensions, suggesting the presence of surface structures which might have blocked the reactions. The titres of the whole-cell antisera were not significantly higher than those of O-antisera, but the reactions were more definite and easier to read. This system may prove useful in serological studies of B. fragilis.


Various methods of lymphocyte separation and their relevance with the formation of non-immune rosettes.

Lymphocytes (leukocytes mainly containing mononuclear cells) are separated by six different methods and these lymphocytes are used for non-immune rosette formation. It is found that the percentage of non-immune rosettes varies according to the method of separation of lymphocytes. Buffy coat on Dextran-70 and Gravity Sedimentation method give the best rosette yields as compared with lymphocytes separated by centrifugation of heparinized blood (unsupported centrifugation) P less than 0.001) or on Hypaque-Ficoll or Diaginol-Ficoll gradients (supported centrifugation) P less than 0.05). Furthermore, the buffy coat separated on Dextran-70, layered on Ficoll-gradients (supported centrifugation) yields lower values of rosettes (P less than 0.05). It is possible that in certain methods which yield lower values of rosettes there is loss of selected subpopulations of lymphocytes. This loss of subpopulation appears to be due to the centrifugation of the blood and the loss is appreciably more on 'unsupported' than 'supported' centrifugation.


A sensitive rosetting method for detecting subpopulations of lymphocytes which react with alloantisera.

A procedure is described for directly estimating the proportion of mouse lymphoid cell suspensions which react with alloantisera. The method entails reacting Ig-capped lymphoid cells with alloantisera, and then assessing the uptake of alloantibodies by rosetting the lymphocytes with SRBC coated with sheep IgG specific for mouse Ig. This rosetting procedure was found to be generally more sensitive than the conventional dye exclusion microcytotoxicity test for detecting the binding of alloantibodies to lymphocytes. Furthermore, the rosette method has the advantage that, unlike the complement lysis technique, it has a low and reproducible background and lymphocyte subpopulations which react with alloantisera can be isolated.


Preparation of trinitrophenylated red cells for antibody independent lysis by complement.

Based on the earlier observation that DNP-HSA interacts directly with C1q, a subcomponent of the first component of complement (Loos and König, 1977), evidence is presented that TNP bound to erythrocytes (E-TNP) can interact with the whole complement sequence leading to the lysis of the TNP-carrying erythrocytes; in this test system the erythrocytes are used as an indicator of the TNP-complement reaction. To exclude any antibody-mediated lysis either the heterologus sera were exhaustively absorbed with the erythrocytes used in the test system or serum and erythrocytes of one individual person were taken. The strongly temperature-dependent interaction of TNP-sulfonic acid with the erythrocytes resulted in the formation of E-TNP as well as of a TNP-protein complex released into the supernatant. The TNP-protein complex strongly inhibited purified C1 similar to DNP-HSA. The antibody independent lysis of E-TNP by complement was dependent upon the TNP concentration per cell, the temperature and time as well as the complement concentration. The reaction of E-TNP with complement showed similar characteristics to those for the reaction of antibody sensitized erythrocytes (EA) with complement. E-TNP is a helpful tool to study antibody-independent activation of the complement system.


A sandwich method of enzyme-immunoassay. II. Quantification of rheumatoid factor.

A sandwich enzyme-immunoassay (EIA) has been applied to the determination of the rheumatoid factor (RF). This non-competeitive assay comprises 3 steps: 1) the RF to be assayed is extracted for the biological medium by an immunosorbent of aggregated IgG linked to cellulose; 2) the solid phase is then incubated with the enzyme-labeled aggregated IgG; 3) the enzymatic activity of the immunosorbent is then measured with a suitable chromogenic reagent. This activity is a direct function of the amount of RF to be assayed. This assay gave reproducible results in the range 0.5-50.0 IU/ml. A good agreement was obtained between the EIA and the Waaler-Rose test but no correlation was obtained with the latex slide-test. This assay permits a quantitation of RF with a good reproducibility (coefficient of variation in the range of 10% for moderately elevated values) and thus allows a closer follow-up of patients. The results do not depend on the interpretation of the technician performing the test, which can be easily automated. Finally, it may detect some RF devoid of agglutinating activity.


Cellular assay for measuring anti-erythrocyte antibody responses.

Splenocytes from mice immunized with sheep red cells (SRC) or donkey red cells (DRC) were able to lyse radiolabeled SRC or DRC respectively. The cytotoxic effect was mediated by the active supernatant which was released from the immune splenocytes and which was characterized as antibody. This cellular cytotoxic response was found to be a very reliable, efficient, rapid and objective assay for measuring anti-erythrocyte antibody responses.


A simple microtitration technique for quantitating total haemolytic complement levels.

A simple microtitration technique for the determination of total haemolytic complement levels in human serum is described. The method is fast and reproducible, and provides a routine screen of total complement activity for use in clinical medicine.


Haemagglutination assay for HBsAg -- a new approach to reagent preparation.

Human group O rhesus negative erythrocytes were spherocyted and fixed in glutaraldehyde, then coated initially with HBsAg and subsequently with anti-HBs. The resulting reagent was found to agglutinate in the presence of HBsAg positive serum, but not in HBsAg negative serum. The assay was evaluated for blood donor screening (39,962 donations) over a 6-month period, and was compared with Hepatest (RPHA) and AUSRIA-2 (RIA) for the study of two established HBsAg panels.


An improved method for detection and titration of antibodies cytophilic for macrophages.

A new microtechnique for detection and titration of antibodies cytophilic for homologous macrophages is introduced and experiments designed to determine the optimum conditions for its performance reported. The technique employs a series of small chambers formed on a microscope slide by the application of a plastic film in which holes have been punched. The procedure uses 5 x 10(4) cells and 25 microliter of serum per chamber, and each test can be completed in 2 h. A permanent preparation results which can be examined as and when convenient.


A method for measuring cyto-adherence on frozen tissue sections.

A simple method for quantifying the cells adhering to frozen sections of mouse spleen using a microscope equipped with a drawing tube attachment, and a planimeter is described. It is a straightforward and reproducible technique which was been preliminarily employed to study optimal binding conditions for Esheep and EoxAC.


Quantitation of leukotaxis in agarose by three different methods.

The agarose method for measuring chemotaxis has been rigorously examined by a variety of quantitative approaches, including measurements of the distance of cell migration ('leading front'), counts of total numbers of migrated cells, and counts of migrated cells in single planes. These methodologies are described in detail. It is demonstrated for the first time that the results are dependent on the concentration of chemotactic factor. Results obtained by the three quantitative methods are similar. Measurement of cells migrating in a single plane is preferable because this method is reliable and relatively simple. The assay conforms to a pattern determined by checkerboard analysis that confirms a true chemotactic response.


Ornithine decarboxylase in rat skin.

Ornithine decarboxylase (ODC; E.C.4.1.1.17) activities can be stimulated 2-10 fold in rat epidermis and dermis by hair plucking. Stimulation does not involve the removal of a soluble ODC inhibitor. ODC activity in the dermis and whole skin decreased with aging, while the epidermis showed little change. The apparent Km for ornithine and the heat stability of ODC in plucked and unplucked skin were similar. ODC was assayed in plucked and unplucked skin of rats fed diets containing between 2 and 24% protein. Activities in both plucked and unplucked skin were higher in the animals fed diets with higher protein contents. ODC levels were positively correlated with the weight changes undergone by rats on controlled-protein diets. In animals restricted to 2% protein diets and rehabilitated with 16% protein diets, enzyme levels were increased after 2 days rehabilitation and peaked after 5 days rehabilitation. The responsiveness of ODC to changes in dietary protein may be useful in the diagnosis of protein malnutrition.


Plasma immunoreactive beta-melanocyte-stimulating hormone in chronic liver disease and fulminant hepatic failure.

Hyperpigmentation believed to be due to melanin, is a feature of chronic liver disease, especially primary biliary cirrhosis and hemochromatosis. Normal plasma concentrations of immunoreactive beta-melanocyte-stimulating hormone (beta-MSH) have been found in both these conditions; thus elevation of plasma beta-MSH plays no role in the pathogenesis of hepatic pigmentation. Normal levels are also found in hepatocellular failure, which supports the hypothesis that the kidney and not the liver is the site of metabolism of this hormone.


Increased sebaceous gland activity in the adult rat after alpha-melanocyte-stimulating hormone treatment during early life.

Sebum secretion was measured in adult female and male rats given alpha-melanocyte stimulating hormone (alpha-MSH) during early life. Daily treatment with 40 microgram alpha-MSH/100 gm body weight for the first 5 weeks of life increased sebum secretion in female and male rats at 8, 11, and 15 weeks of age. A lower dose of alpha-MSH (10 microgram/100 gm body weight) produced similar changes in male but not in female rats. No effect on sebum secretion was found in female and male rats aged between 8-28 weeks when alpha-MSH was given (1) from the day of birth to 3 weeks; (2) 3--5 weeks; (3) 1st and 5th weeks and (4) 7--12 weeks. Apparently alpha-MSH must be given throughout the first 5 weeks of life in order to produce a sustained effect on the sebaceous glands. The fact that males appear to be more sensitive than females, in that they responded to a lower dose of alpha-MSH, may indicate that MSH acts by enhancing the response to androgen. Early alpha-MSH treatment failed to alter the sebaceous gland response to testosterone in adult female and male rats but the possibility that alpha-MSH enhances the action of androgen in early life cannot be ruled out.


Growth rate of cultured human fibroblasts increased by glucocorticoids.

Selected glucocorticoids have been demonstrated to increase the growth rate of human skin fibroblasts in culture, over a physiologically significant concentration range. At the same concentrations and identical conditions, the glucocorticoid compounds tested inhibited the growth rate of mouse L-929 cells. We have discussed currently acceptable theories of glucocorticoid mechanism of action that permit this dichotomous effect, the main point being that inhibition can no longer be regarded as the only response of fibroblasts to glucocorticoids. Conclusions drawn from observations of cell cultures affected by addition of glucocorticoids must have considered the source of the cells, as response may vary with source and biologic state of the cells in culture.


Mast cell analyses in hypertrophic scars, hypertrophic scars treated with pressure and mature scars.

Granulation tissues, hypertrophic scars, hypertrophic scars treated with mechanical pressure and mature scars from deep thermal injuries, or equivalent trauma, were examined for the presence and dermal distribution of mast cells. Statistical analyses of mast cell counts indicate that 1) the hypertrophic scar contains significantly greater numbers of mast cells than the other tissues studied. 2) as granulation tissue develops interstitial collagen, mast cells begin to appear, 3) mature scars contain significantly fewer mast cells than hypertrophic scars, 4) based on mast cell data, the effect of pressure therapy is first detected in the upper and middle reticularis of the dermis, and 5) on a mast cell statistical basis mature scar and hypertrophic scar under pressure are indistinguishable.


Enhancement of L-dopa incorporation into melanoma by dopa decarboxylase inhibition.

Melanoma cells possess a special biochemical pathway for the conversion of L-dopa to melanin. Selective incorparation of exogenous L-dopa into melanoma cells in vivo has been limited by extensive decarboxylation to dopamine. Pretreatment of animals bearing the S-91 Cloudman or ACI melanomas with Ro4-4602, a potent dopa decarboxylase inhibitor limited incorporation of label into adrenal tissue and enhanced entry of label into tumor. Six hours following pretreatment, the ratio of tumor to adrenal specific activities was altered from 0.25 to 1.5 for the S-91 melanoma and 0.68 to 1.99 for the ACI melanoma indicating diversion of metabolism away from catecholamine formation. The possibility of a selective diagnostic and/or therapeutic approach is proposed.


Measurement of lactic acid in cerebrospinal fluid of patients with infections of the central nervous system.

The concentration of lactic acid in cerebrospinal fluid (CSF) was determined by gas-liquid chromatography in 205 samples of CSF from 97 patients with or without infections of the central nervous system. Patients without infection or those with nonbacterial (presumably viral) meningitis consistently had low concentrations of lactic acid in CSF (i.e., less than or equal to 35 mg/100 ml), whereas patients with bacterial or tuberculosis meningitis consistently had concentrations of lactic acid in CSF of greater than 35 mg/100 ml. There was no overlap in concentrations of lactic acid between these two groups. Further, lactic acid concentrations in CSF from patients partially treated for meningitis were generally greater than 35 mg/100 ml through the third day of therapy and, thereafter, progressively declined to less than 20 mg/100 ml by the seventh to 10th day of therapy. Relapse of bacterial infection was consistently documented by a recurrence of an increased concentration of lactic acid in CSF. Preliminary experience with determination of the concentration of lactic acid in CSF suggests that it may be useful in distinguishing bacterial (with or without positive cultures) and tuberculous meningitis from meningitis due to nonbacterial causes.


Coxsackievirus B4 myocarditis in mice: valvular changes in virus-infected and control animals.

Suckling, weanling, and adult HaM/ICR and Swiss-Webster mice were inoculated intraperitoneally with the TC631 and Dowell strains of coxsackievirus B4. Vero cell-inoculated and uninoculated control mice were also studied under code. An intense, necrotizing myopericarditis was produced in suckling mice; it was less severe in weanlings. Myocarditis did not occur when coxsackievirus B4 was inoculated into adult mice. Progressive sclerosis and thickening of all valves in both strains of mice were observed with equal frequency in infected and control mice. There was no evidence that coxsackievirus B4 induced a specific valvular or endocardial lesion.


Inactivation of penicillin G during experimental infection with Bacteroides fragilis.

An animal model implanted with intraperitoneal plastic reservoirs was used for study of the penetration of penicillin G into sites infected with Bacteroides fragilis. Penicillin G was given to rabbits, and its concentration in uninfected reservoirs and in those infected with B. fragilis was determined. The mean percentage penetration ([concentration in capsule divided by peak concentration in serum] X 100) of penicillin into uninfected capsules was 19.9%, whereas that into heavily infected capsules was 1.5%. The percentage penetration of radiolabeled penicillin into infected capsules was 12.5%, whereas the proportion of bioactive drug in the same capsules was again very low (1%). These results show that there is a modest reduction in penetration of penicillin into infected sites and a striking inactivation of the drug by B. fragilis in this experimental model.


Infection of the uterine cervix with Chlamydia trachomatis.

For identification of those variables in the history and in the clinical and routine laboratory examination that are most likely to indicate infection of the uterine cervix with Chlamydia trachomatis, 284 women attending a venereal disease clinic were studied, were studied, of whom 58 (20.4%) yielded the organism from the cervix. Women with chlamydial cervical infection showed no distinctive symptoms. Although associations were found between the presence of C. trachomatis and cervical discontinuity, purulent cervical exudate, and inflammatory changes in cervical cytology, these signs were not pathognomonic of chlamydial infection since they were also seen in some women infected with other microorganisms. There was a significant relationship between the presence of antibodies, detected by immunofluorescence, and the recovery of C. trachomatis in cell culture. There were no associations between ethnic group, history of sexually transmitted disease, method of contraception, phase in the menstrual cycle, or numbers of sexual contacts and infection with C. trachomatis.


Interaction of cephalosporins with human and canine serum proteins.

The kinetic interaction of cephalothin and cefamandole with human serum protein and of cephalothin with canine serum protein was studied with use of a rate-of-dialysis method. Binding of antibiotic to serum proteins was complete in less than 1 min and was immediately reversible. Human serum bound 76.9% of cephalothin and 73.7% of cefamandole at 10 microgram/ml, and canine serum bound 41.3% of cephalothin at 10 microgram/ml when this technique was used. Quantitative binding determined by ultracentrifugation was 78.5% for cephalothin and 80.1% for cefamandole in human serum and 45.6% for cephalothin and 32.5% for cefazolin in canine serum. There was no delayed binding of these antibiotics to either human or canine serum. In addition, a large number of antibiotic-binding sites appeared to be present on both human and canine serum protein when the antibiotic concentration was increased to 10(5) microgram/ml.


Clindamycin-induced enterocolitis in hamsters.

A lethal enterocolitis was induced in hamsters by oral or parenteral administration of clindamycin in amounts comparable to those used in treatment of humans. The intestinal lesions were characterized histologically as an acute inflammatory reaction with pseudomembrane formation and resembled the lesions seen in humans with antibiotic-induced colitis. Results of quantitative stool cultures showed the numbers of Peptostreptococcus and Corynebacterium decreased in animals with colitis after challenge with 100 mg of clindamycin/kg, while numbers of Escherichia coli, Streptococcus faecalis, and clindamycin-resistant Clostridium sordellii and Clostridium difficile increased. Bacteria were not seen within the intestinal lesions. Viruses were not isolated from hamsters with colitis. Although the pathogenesis of this syndrome is not completely established, the evidence is consistent with the hypothesis that the disease is caused by clostridial toxins and that the production of these toxins by organisms within the intestines is enhanced by the effects of clindamycin upon the bowel flora.


Effects of infection with Coxiella burnetii on synthesis of RNA in L cells.

Experimental infections with Coxiella burnetii augment rates of ribonucleic acid (RNA) synthesis in guinea pigs. The activity of deoxyribonucleic acid-dependent RNA polymerase in L cells persistently infected with C. burnetii was threefold greater than that in unifected cells; the polymerase activity in infected cells was predominantly of class I, whereas that in uninfected cells was predominantly of class II. A search for regulatory factors of polymerase activity revealed that preincubation of uninfected L cells with lipopolysaccharide of C. burnetii or with putrescine, spermidine, or spermine enhanced polymerase activities. Because sonicated nuclei were assayed rather than purified enzymes, it cannot be stated definitely whether augmented polymerase activites were consequences of direct effects of infection on polymerases or a triggering of secondary regulatory factors.


Comparative beta-lactamase resistance and antistaphylococcal activities of parenterally and orally administered cephalosporins.

Two parenterally administered cephalosporins (cephalothin and cephapirin) and four orally administered cephalosporins (cephalexin, cephradine, cefatrizine, and cefaclor) were investigated by use of 29 beta-lactamase-producing strains of Staphylococcus aureus for determination of their relative rates of hydrolysis (RH) by beta-lactamase (RH of penicillin G =100) and their antistaphylococcal activities. Cephalothin (RH less than 0.01) and cephapirin (RH = 0.1) were relatively stable in the presence of staphylococcal beta-lactamase. Cephalexin and cephradine (RH of each = 0.3) were less stable than cephalothin and cephapirin but more stable than cefatrizine (RH = 1.4) and cefaclor (RH = 3.4). Agents that were more resistant to hydrolysis were affected less by the size of the inoculum when tested against large ;(10(7)) and small (10(3)) inocula of beta-lactamase-producing staphylococci than those that were hydrolyzed rapidly. Cephalothin and cephapirin were four to eight times more active than the orally administered cephalosporins against 10(3) staphylococci. Cephalosporins that are relatively stable in the presence of staphylococcal bata-lactamase may be preferable to less stable ones for treatment of serious infections due to beta-lactamase-producing staphylococci.


Differential inactivation of cephapirin vs. cephalothin by penicillin-resistant strains of Staphylococcus aureus: a preliminary study.

The bactericidal effectiveness of cephapirin and cephalothin against small (approximately 10(5)) and large (approximately 10(8)) inocula of penicillin-resistant Staphylococcus aureus was evaluated. With the smaller inoculum, no differences in bactericidal activity between the two drugs (tested at 2 and 40 microgram/ml) were seen after incubation for 2, 4, 6, or 24 hr. Neither cephalosporin effectively killed a larger inoculum in a concentration of 250 times the minimal bactericidal concentration for selected strains. Total inactivation of cephapirin (40 microgram/ml) by eight of 13 strains was demonstrated with the larger inoculum. These preliminary studies indicate that inactivation of cephapirin is pH-dependent. No strain inactivated cephapirin in less than or equal to 4 hr. Inactivation was independent of temperature at 37 C and 42 C. Although cephalothin was resistant to inactivation under the same conditions, the inoculum required to inactivate cephapirin was not killed by 100 microgram of cephalothin/ml. Although strains of S. aureus that slowly inactivate cephapirin appear to be prevalent, no strain that rapidly inactivates this cephalosporin was identified.


Cefamandole in treatment of peritonitis.

Cefamandole was evaluated as the sole antimicrobial agent used to treat bacterial peritonitis in 113 patients. Dosage varied between 1 and 2 g given intravenously every 6 hr. Laparotomy for excision of infected or gangrenous tissues, closure of gastrointestinal perforations, or drainage of an established abscess was required in 99 of the cases. A good clinical response was obtained in 107 patients, or 95% of the total group. Of the six deaths only one could be attributed to infection. No evidence of renal, hepatic, or hematopoietic toxicity was noted. There were no allergic reactions, although 13 patients (12%) developed phlebitis in a vein used for antibiotic administration. Bacteriological studies revealed aerobic peritonitis in 99% of the patients, with anaerobe participation in 60% of these cases. Sensitivity testing by the disk diffusion and tube dilution methods confirmed the appropriateness of cefamandole therapy; 91% of the gram-negative rods and 61% of the anaerobes were susceptible. From results of this study, it would appear that cefamandole is a reliably effective antibiotic for use in treatment of most forms of acute peritonitis. Its role in surgical prophylaxis may be even more promising.


Clinical experience with cefamandole for treatment of serious bone and joint infections.

The safety and efficacy of treatment with cefamandole were evaluated in 30 patients (from 18 institutions) with serious bone and joint infections. Five of the subjects were children. The antibiotic was given intramuscularly or intravenously in doses ranging from 2 to 12 g daily for five to 44 days. Twenty-six of the 30 patients responded satisfactorily. Fourteen of the fifteen infections due to Staphylococcus aureus were among the successful cases. Other pathogens were streptococci, Escherichia coli, Proteus mirabilis, and Bacteroides fragilis. The drug was well tolerated in patients in this series. Studies indicated that cefamandole penetrated the bones and joints. Further investigation of cefmandole in the treatment of bone and joint infections is warranted.


Cefamandole in the treatment of infections due to Enterobacter and indole-positive Proteus.

Clinical and bacteriologic results are reported for 80 patients treated with 1.5--12 g of cefamandole daily for a variety of infections caused by Enterobacter and indole-positive Proteus, organisms that have been resistant to most available cephalosporins. Of 45 patients with infections due to Enterobacter, 41 (91%) had satisfactory clinical responses; 36 were bacteriologic successes, and six cases of complicated urinary tract infections relapsed. Of 37 patients with infections due to indole-positive Proteus, 28 (88%) were clinical successes and 30 (81%) were bacteriologic successes. Fourteen cases of complicated urinary tract infection relapsed. Of 104 patients in whom the drug was evaluated for safety, use of cefamandole was discontinued in five; nine adverse reactions were considered drug-related. A summary of published in vitro data shows that the majority of strains of these organisms were susceptible to cefamandole at concentrations achievable in the serum. Minimal inhibitory concentrations are variable, and there is a significant inoculum effect, the clinical significance of which has not been determined.


Carbenicillin plus cefamandole in the treatment of infections in patients with cancer.

The combination of carbenicillin plus cefamandole was administered to 88 patients with cancer during 116 evaluable episodes of fever. The overall response rate to carbenicillin plus cefamandole for the 116 episodes was 57%. There were 60 documented infections, of which 60% responded to this combination of antibiotics. The response rate was only 43% in patients with pneumonia. The etiologic agent was identified during 38 infections, of which 74% responded to carbenicillin plus cefamandole. Responses occurred less frequently in patients with neutropenia than in those without neutropenia and less frequently in patients whose infection was caused by organisms resistant to both antibiotics than in those with infection caused by organisms sensitive to one or both of the drugs. No side effects could be attributed to the antibiotic regimen.


Cephalosporin antibiotics in therapy of experimental Streptococcus pneumoniae and Haemophilus influenzae meningitis in rabbits.

Six cephalosporin antibiotics (cefamandole, cefazolin, cephacetrile, cephalothin, cephaloridine, and cephradine) and two penicillin (ampicillin and penicillin G) were evaluated in vitro and in a rabbit model of experimental meningitis due to Haemophilus influenzae or Streptococcus pneumoniae. The percentage penetration ([concentration in cerebrospinal fluid/concentration in serum] X 100%) of these antibiotics varied from 0.7% for cephalothin to 17% for cephaloridine. The penetration varied inversely with binding to serum proteins. The bactericidal rate of all of the cephalosporin antibiotics was similar in vitro and in vivo to that of penicillin G. However, as demonstrated with cephalothin, concentrations considerably above the minimal bactericidal concentration (as determined in broth) were necessary to initiate the bactericidal effect. Cefamandole was found to be as effective as ampicillin in the therapy of H. influenzae meningitis in rabbits.


Hydrolysis of cefamandole nafate to cefamandole in vivo.

The hydrolysis of cefamandole nafate, and the O-formyl ester of cefamandole, to cefamandole was studied in vivo in dogs and normal human subjects. After administration of cefamandole nafate to dogs or humans, the parent compound disappeared rapidly from plasma. Disappearance was slightly faster in dogs (half-life [t1/2], 4--6 min) than in humans (t1/2, 6--9 min). The calculated rate constant for hydrolysis of cefamandole nafate was also higher in dogs than in humans, yielding t1/2 values of 6--7 min and 10--17 min, respectively. The rapid hydrolysis of cefamandole nafate to cefamandole in vivo, combined with the partial hydrolysis of cefamandole nafate in vitro before administration (caused by Na2CO3 in the formulation), resulted in circulating levels of cefamandole nafate lower than those of cefamandole. In humans the disappearance of cefamandole nafate was not significantly altered after administration of large (4.0 g) or multiple (4.0g every 6 hr) doses of cefamandole nafate.


Toxicologic evaluation of cefamandole nafate in laboratory animals.

The safety of cefamandole nafate in laboratory animals was evaluated in six species. The acute toxicity of cefamandole after intravenous or subcutaneous administration was similar to that of cephalothin sodium. The subacute and chronic toxicity of cefamandole was studied in rats and dogs for periods of two weeks to six months at doses of 250--1,000 mg/kg per day in rats and 125--1,500 mg/kg per day in dogs. No evidence of significant systemic toxicity was observed in these studies. There were, however, various degrees of local injury at the injection sites that resulted in slight decreases in hemoglobin, hematocrit, and red blood cell counts in the animals in which injury at the injection site was most severe. Studies of reproduction in rats and mice indicated that cefamandole nafate had no teratogenic effects and no adverse effects on fertility, gestation, or growth of offspring. Comparative studies of nephrotoxicity in rabbits demonstrated that the nephrotoxicity of cefamandole nafate was considerably less than that of cefazolin.


The nephrotoxicity of cephalosporins: an overview.

The cephalosporin antibiotics cephaloridine and cephalothin are known to cause renal damage. Experience with newer congeners is not yet sufficient to predict their potential nephrotoxocity. The renal lesion produced by cephaloridine is primarily due to the intrinsic toxicity of this drug for the cells of the proximal renal tubule and depends upon its peculiar transport characteristics. In contrast, renal injury due to cephalothin resembles that seen with the penicillins. Thus, some instances of cephalothin nephropathy appear to be toxic in nature with a histologic picture of acute tubular necrosis, whereas others exhibit signs of hypersensitivity including rash, eosinophilia, and interstitial nephritis. Among the factors alleged to contribute to the nephrotoxicity of cephalosporins is their administration with aminoglycosides. Although the physician should be aware of the possibility of a potential adverse interaction between these groups of antibiotics, the evidence is not sufficiently conclusive to warrant avoidance of the combination when it appears to be therapeutically useful.


Comparison of the pharmacokinetics of cefamandole and other cephalosporin compounds.

The pharmacokinetic properties of cefamandole were determined and compared with the properties of other cephalosporin agents. Cefamandole was found to be approximately 70% bound to protein. The mean peak concentration in serum after intramuscular (im) injection of 1 g of cefamandole was 20 microgram/ml at 0.5 hr, whereas the level at 6 hr was 1 microgram/ml. After intravenous (iv) infusion of 1 g of cefamandole, levels in serum ranged from 68 to 147 microgram/ml depending on the period of infusion. At 4 hr after infusion, levels were less than 1 microgram/ml. Probenecid elevated serum levels and prolonged excretion. The half-life (t1/2) of cefamandole after im injection ranged from 1 to 1.5 hr and from 0.45 to 1.2 hr after iv injection. Rates of serum and renal clearance of cefamandole ranged from 210 to 300 microliter/min per 1.73 m2. The apparent volume of distribution ranged from 12.4 to 17.9 liters/1.73 m2. Urinary excretion was rapid, with 60% of a dose excreted in the first 2 hr after injection. In 6 hr 90% of a dose was excreted. The pharmacokinetic properties of cefamandole were similar to those of cephalothin and cefoxitin, but the serum t1/2 was shorter than that reported for cefazolin and cefuroxime. Correlation of in vitro studies with pharmacokinetic properties revealed that cefamandole would inhibit most susceptible gram-positive and gram-negative bacteria if given by suggested im or iv regimens.


The detection of "purified" incubation damage by several radioimmunoassay separation methods.

Damage to labeled peptides has been recognized as an almost unavoidable consequence of exposure to plasma during radioimmunoassay incubat ions, which can cause serious errors in estimating plasma hormone concentrations. Surprisingly little is known about the nature and behavior of damaged labeled peptides in various systems for separating antibody-bound from free labeled hormones. This is due in part to lack of a generally applicable definition of "incubation damage" as an altered molecule rather than a phenomenon observed in the separation system. We have proposed the definition, "nonimmunoreactive radioactive peptide(s) produced during incubation of radioactively labeled peptide antigens." With 125I-hbetaMSH used as a model labeled peptide antigen, incubation damage was produced under defined conditions and purified by gel filtration. It appeared smaller than 125I-hbetaMSH, suggesting that it resulted from enzymic proteolysis. The behavior of purified incubation damage in five representative separation systems was not consistently predictable. In the paper chromatoelectrophoresis and QUSO-plasma systems, it behaved like a large molecule, partitioning in the "bound" phase. In these two systems, incubation damage must be detected in appropriate control tubes containing the specimen without antibody. In the dextran-charcoal, polyethylene glycol, and second-antibody systems, damage behaved like a small nonimmunoreactive peptide and partitioned in the "free" phase. In these systems, since incubation damage cannot be separated from free 125I-labeled peptide, damage control tubes must have excess antibody added after incubation. The apparent lack of incubation damage in some radioimmunoassays may be due to inappropriate controls for its detection, leading to erroneous estimation of plasma hormone concentrations.


Sodium transport in dogs with acute remnant and glomerulonephritic kidneys.

The nephron site responsible for the different patterns of sodium excretion in response to extracellular volume expansion observed in dogs with bilateral acute remnant kidneys, acute NTN, and normal kidneys was studied with clearance and micropuncture techniques. Mean kidney GFR's in the remnant and NTN kidneys were similar at 14 and 15 ml/min, respectively, compared to 28 ml/min for the normal kdineys. However, SNGFR's were normal in the remnant kidneys but markedly reduced in dogs with NTN. Mean absolute sodium excretion was similar for the remnant and normal kidneys both during the control phase and after volume expansion. Because of the reduced GFR, FENa of the remnant kidneys was significantly higher in each situation. In contrast, mean absolute sodium excretion was markedly less in dogs with NTN than in normal dogs both before and after volume expansion. Although FENa during the control phase was similar to that in normal dogs, it increased significantly less with volume expansion. Despite these differences in urinary sodium excretion, the percent sodium reabsorption at the end of the proximal convoluted tubule was similar in all three groups. In addition, volume expansion depressed proximal SFENa to the same degree in each group. Therefore the different patterns of urinary FENa were the result of differences in fractional sodium reabsorption by the nephron segments distal to the proximal convoluted tubule. Decreased distal delivery of sodium secondary to the reduced SNGFR also contributed to the decreased sodium excretion in acute NTN.


Human hexosaminidase isozymes. III. Distribution and activity of isozymes in peripheral blood leukocytes and platelets.

The specific activity and distribution of the isozymes of hex have been studied in platelets, granulocytes, monocytes, and lymphocytes isolated from venous blood. Since there are considerable differences in the content of the various hexosaminidase isozymes in these cell types, the relative activity of the A isozyme, expressed as a percent of total hexosaminidase in a mixed leukocyte preparation, is dependent on the proportion of the individual cell types present in a sample of peripheral blood. Because of variation in the proportion of cell types, the results may not accurately reflect the genotype of the blood donor. In contrast, chromatographic separation and assay of platelet extracts for activity of hexosaminidase isozymes provides a most convenient and satisfactory method of discriminating carriers and noncarriers of the Tay-Sachs mutant gene. Moreover, the ease of isolating platelets and the smaller volume of blood required compared with methods for obtaining purified leukocyte preparations offer additional advantages for identification or verification of the Tay-Sachs heterozygote state.


Carbamylation distributions in extracorporeal treatment of sickle cell anemia.

The extracorporeal exposure of blood from patients with sickle cell anemia results in the binding of different amounts of cyanate to the hemoglobin of individual erythrocytes. This distribution pattern of carbamylated hemoglobin may affect the efficacy of treatment. A computer model has been developed to predict the carbamylation distribution attained in batch ex vivo exposures. In addition, an autoradiographic technique has been developed whereby the actual distribution pattern of carbamylated hemoglobin in small volumes of blood can be determined. Agreement was demonstrated between the computer model predictions and the actual distribution patterns. The model was applied to published results of extracorporeal treatments of sickle cell patients, and profiles of loading were compared. With the use of such approaches it will be possible to test the importance of the erythrocyte distribution of carbamylated hemoglobin on clinical effects and to design protocols to achieve an optimum distribution. The procedure may be adapted to the distribution of other therapeutic agents as they become available.


Experimental pneumococcal meningitis. IV. The effect of methyl prednisolone on meningeal inflammation.

This study was undertaken to determine whether adrenal corticosteroids suppress meningeal inflammation in experimental pneumococcal meningitis in rabbits and, if so, whether the mechanism of suppression involves inhibition of chemotactic activity in CSF or modification of granulocyte responses to inflammation mediators. It was found that methyl prednisolone, administered intramuscularly in doses of 15 or 30 mg/kg 24 hr and 48 hr after induction of meningitis, significantly reduced (p less than 0.01) the mass of granulocytes present in the meninges 72 hr after infection, the time of maximum meningeal inflammation. The larger dose of steroid produced approximately twice the suppressive effect of the smaller dose (p less than 0.05). The regime of methyl prednisolone that produced maximal suppression of meningeal inflammation (30 mg/kg/day) did not alter CSF chemotactic activity or chemotactic responsiveness and phagocytic activities of granulocytes from rabbits with meningitis. However, steroid therapy inhibited an increase in granulocyte adherence that was observed in untreated animals with meningitis (p less than 0.05). Thus methyl prednisolone in doses of 15 and 30 mg/kg given daily to rabbits with pneumococcal meningitis produced a suppressive effect on meningeal inflammation that was dose-dependent and was possibly mediated by inhibition of granulocyte adherence.


Effects of ultrafiltration on solute clearances in cuprophan and cellulose hollow fiber dialyzers: in vitro and clinical studies.

Hollow fiber dialyzers are currently available with either regenerated cellulose or thinner walled cuprophan fibers. In vitro and clinical studies were undertaken to compare a cellulose with a cuprophan dialyzer in regard to (1) UF's, (2) small and large solute clearances at high and low TMP's, (3) SC's, and (4) effects of ultrafiltration on diffusive and convective components of clearances. The results show that per square meter of surface area, the cuprophan dialyzer has higher rates of UF per TMP and greater clearances, particularly of larger solutes; also with cuprophan the SC for vitamin B12 is higher. Thus all findings suggest greater permeability of cuprophan fibers. In both dialyzers, total clearances increased with UF by amounts compatible with predicted increases in convective transport; diffusive transport remained stable as TMP was increased.


Effects of tympanic neurectomy on experimentally induced parotid fistulae.

The present work was designed to determine whether or not tympanic neurectomy alone could cure parotid fistulae. In six adult dogs parotid fistulae were induced and the tympanic nerve was transected on the right, while the nerve on the left side was left intact as a control. Complete healing of the fistulae on the right side was noticed, while those on the left side persisted. The findings and their significance are discussed.


Rhabdomyosarcoma of the larynx. Report of two cases and a review of the literature.

The rhabdomyosarcoma is a relatively rare tumour form. Two cases in the larynx--a site which is extremely rare--are reported. So far, only 9 cases have been described and documented, and of one of our cases seems to be the first of the alveolar type found at this site. Diagnostic and differential-diagnostic considerations are discussed. Hoarseness is the commonest and earliest symptom. As stated by most authors, the treatment should be radical operation, often with laryngectomy, supplemented by irradiation and chemotherapy.


Fibrosarcoma in a previously irradiated larynx.

The patient presented in this report had a rare tumour occurring in a situation suggestive of a radiation-induced mesenchymal neoplasm. Attention is drawn to the need for prolonged follow-up in cases of squamous carcinomata of the larynx apparently disease free for many years following irradiation.


Aneurysm of the external carotid artery following a foreign body in the pharynx.

A case of false aneurysm of the external carotid artery following impaction of a fish bone in the pharynx is reported. An incorrect preoperative diagnosis led to a near-fatal issue. Reference is made to some other reports of arterial injury following impaction of foreign bodies in the throat. The various factors in the erroneous diagnosis in this case are examined and it is submitted that, although not all the signs of an aneurysm may be present, it should be possible to make a correct preoperative diagnosis of this complication given sufficient awareness of its possibility.


Thyroid carcinoma in Pendred's syndrome.

A case of Pendred's syndrome is reported. One year after subtotal removal of a simple adenomatous colloid goitre, the patient presented with a follicular thyroid carcinoma with invasive growth through the capsule into the surrounding muscular tissue and vascular invasion.


Epidermolysis bullosa and its E.N.T. manifestations. Two case reports.

The present paper describes two rare cases of epidermolysis bullosa dystrophica (recessive), one with oesophageal stricture and another with laryngeal stenosis, along with other usual features of the disease. Different views on the line of treatment of the oesophageal stricture as a complication of this dreadful disease are discussed. Replacement of the strictured oesophagus by coloplasty may be contemplated in the first case, if the patient develops increasing dysphagia. In the second case, with cicatrical stenosis of the larynx and hoarseness of voice which is a rare complication of the disease, not reported in the literature so far, a tracheostomy is contemplated when the child develops acute respiratory distress. These two cases are under observation.


Conversion of diphosphatidylglycerol to bis(monoacylglyceryl)phosphate by lysosomes.

Diphosphatidyl[1',2',3'-14C]glycerol (cardiolipin) is converted to bis(monoacylglyceryl)phosphate when incubated in vitro with rat lysosomes at pH 4.4. The stereochemical configuration of the product is unknown. This reaction probably takes place via lysophosphatidylglycerol, one of the major products of diphosphatidylglycerol hydrolysis by lysosomes. Phosphatidyl[1',2',3'-14C]glycerol was introduced into mitochondrial membranes by incubating mitochondria with [U-14C]sn-glycerol-3-phosphate and cytidine diphosphate diacylglycerol. Membrane-bound phosphatidyl[1',2',3'-14C]glycerol is also converted to bis(monoacylglycerol)phosphate when incubated with lysosomes in a reaction that is dependent on the concentration of lysosomal protein and on incubation time. These results support our previous proposal (Poorthuis, B. J. H. M., and K. Y. Hostetler, 1976. J. Biol. Chem. 251: 4596-4602) that bis(monoacylglyceryl)phosphate formation may require the interaction of lysosomes with other membranes that contain the substrates for the reaction. The stereochemistry of bis(monoacylglyceryl)phosphate biosynthesis is discussed.


Properties of cholesteryl oleate and triolein in mixed monolayers at the air-water interface.

The properties of cholesteryl oleate and triolein in mixed monolayers at the air-water interface have been measured between 24 and 37 degrees C. Analysis of force-area curves obtained as a function of the mol fraction of cholesteryl oleate indicates that at relatively low surface pressures these compounds are miscible in two dimensions up to a limit of about 0.5 mol fraction. At higher pressures either cholesteryl oleate or both lipids are expelled from the monolayer to form a bulk phase which is in rapid equilibrium with the surface phase. In the monolayer phase, orientation of the ester function of cholesteryl oleate is toward the aqueous phase, interaction with triolein is minimal, and packing is uniform over the solubility range. This together with the susceptibility of the cholesteryl oleate to enzymatic hydrolysis, suggests the applicability of monolayer systems to the study of cholesterol esterase activity. Comparison of our results with the bulk properties of these lipids suggests that the expelled cholesteryl oleate exists as a smectic mesophase and thus the system may provide a model for studying the transfer of molecules between the interior and surface of lipid deposits of the type found in atherosclerotic lesions.


Effect of hypervitaminosis A on hemolysis and lipid peroxidation in the rat.

Erythrocytes from rats fed large doses of Vitamin A alone, or large doses of vitamin A and vitamin E or diphenyl-p-phenylene diamine (DPPD) were studied for H2O2-induced hemolysis. The vitamin A-dosed rats were more susceptible than normal rats to H2O2-induced hemolysis. Hemolysis was not accompanied by lipid peroxidation. Nevertheless, the antioxidants vitamin E and DPPD inhibited hemolysis in erythrocytes from vitamin A-dosed rats. These antioxidants had the same inhibitory effect when they were included in the diet or added to erythrocyte suspensions in vitro. Erythrocytes from vitamin A-dosed rats with or without added vitamin E or DPPD were less susceptible than the erythrocytes from normal rats to osmotic challenge, showing that vitamin A was present in levels sufficient to alter the structure of the erythrocyte membrane. These studies show that oxidative hemolysis occurs when the erythrocyte membrane is modified. Furthermore, this oxidative hemolysis is unrelated to lipid peroxidation.


Effect of different dietary triglycerides on 7alpha-hydroxylation of cholesterol and other mixed-function oxidations.

The effect of a diet containing triglycerides of different fatty acid composition on hepatic 7alpha-hydroxylation of cholesterol was studied. 7alpha-Hydroxylation of exogenous as well as endogenous cholesterol was significantly lower in the liver of rats fed trilinolein and triolein than in those fed tripalmitin and trierucin. The concentration of cytochrome P-450 in liver microsomes was significantly lower in the rats fed tripalmitin and trierucin than in those fed triolein and trilinolein. The inhibitory effect of triolein and trilinolein on 7alpha-hydroxylation of cholesterol and the stimulatory effect of these triglycerides on the concentration of cytochrome P-450 was not due to the small amounts of peroxides present in the unsaturated triglycerides. Thus addition of the antioxidant butylated hydroxyanisol did not change the general pattern with respect to 7alpha-hydroxylation and concentration of cytochrome P-450. However, a diet consisting of peroxidized linoleic acid further decreased 7alpha-hydroxylation of cholesterol. The difference between the effect obtained with triolein and trilinolein on the one hand and trierucin and tripalmitin on the other was observed also in experiments with lower concentrations of fat in the diet and in experiments with different lighting conditions and feeding patterns. The inverse relation between cytochrome P-450 and 7alpha-hydroxylation of cholesterol, as well as results obtained with substrates for mixed-function oxidation other than cholesterol suggest that most of the changes observed due to the different diets are specific for 7alpha-hydroxylation of cholesterol. The level of cholesterol 7alpha-hydroxylase activity was found to be better related to the degree of absorption of fat than to total amount of absorbed fat or degree of unsaturation of the fat. The results are discussed in relation to previous knowledge concerning mechanisms regulating biosynthesis of bile acid.


Characterization of trimethylsilyl derivatives of cerebrosides by direct inlet-chemical ionization mass spectrometry.

Submicrogram quantities of trimethylsilyl derivatives of cerebrosides obtained from the spleen of a patient with Gaucher's disease and from bovine brain were analyzed by direct probe inlet-chemical ionization mass spectrometry, using isobutane as the reagent gas. Quasimolecular ions (QM+, M + 73) and other recognizable fragment ions produced by the successive elimination of trimethylsilanol and sugar residue gave useful information about fatty acid compositions. These ions could also be utilized for qualitative analyses of the molecular species of cerebrosides. Cerebrosides with non-hydroxy and hydroxy fatty acids could be discriminated from each other by comparing the intensities of their quasimolecular ions. Cerebrosides with saturated and monounsaturated fatty acids could also be discrimnated from each other, because the mass number decreased by two mass units in cerebrosides with monounsaturated fatty acids. It was concluded that structural information and molecular species determination could be obtained from small amounts of purified cerebrosides.


Characterization of the microsomal steroid-8-ene isomerase of cholesterol biosynthesis.

Rat liver microsomes contain an enzyme that catalyzes the isomerization of the nuclear double bond of steroids from the 8(9) position to the 7(8) position. The enzyme is most active with zymosterol, 5alpha-cholesta-8,24-dien-3beta-ol, which is a precursor of cholesterol. Properties of the microsomal isomerase have now been studied, and preliminary data are reported on both regulation of enzymic activity and first steps in the solubilization of the enzyme from membranes. After a brief lag period, the velocity of isomerase is relatively constant for about 5 min of incubation, and then isomerization subsides. The apparent Michaelis constant (52-70 micro M) is difficult to determine accurately, due to these complex kinetic changes. V(max) is 4.0-4.7 nmol/min per mg of microsomal protein. The apparent specific activity is more than ten times that of liver microsomal methyl sterol oxidase. The maximal specific activity of microsomal isomerase is approximately doubled when rats are fed an intestinal bile acid sequestrant, cholestyramine. Changes in specific activity of isomerase parallel changes in activities of other microsomal enzymes of cholesterol biosynthesis, such as 3-hydroxy-3-methylglutaryl-CoA reductase and 4-methyl sterol oxidase. Isomerase activity is destroyed by phospholipase A digestion, high concentration of bile salts, and solvent extraction, all of which are known either to remove phospholipid or to alter microsomal membrane integrity. On the other hand, isomerase remains active in the presence of a mild, nonionic detergent, Triton WR-1339; thus, solubilization with nonionic detergents is under study.


A rapid and quantitative method for the isolation of gangliosides and neutral glycosphingolipids by DEAE-silica gel chromatography.

DEAE-silica gel has been shown to be an improvement over DEAE-Sephadex for the quantitative isolation of gangliosides and neutral glycosphingolipids from animal tissues or cells. Preliminary results indicated that it can also be used for protein separation. Direct comparative studies of DEAE-silica gel with DEAE-Sephadex showed preferences for the former for the following reasons: i) faster flow rate; ii) more rapid equilibration with the starting buffer; iii) easier regeneration; iv) more economical; and v) a lesser susceptibility to microbial attack.


Digit regeneration in the amphibian--Triturus cristatus.

Digit regeneration has been examined in Triturus cristatus. Because of their size, blastemas that form after digit amputation are relatively a lot more suitable for quantitative studies that involve for example the counting of cells in histological sections. They are also very useful for the study of some basic histological aspects of regeneration particularly cartilage formation. This has been looked at in regenerating digits, as there are only a maximum of three bones to regenerate and these lie in sequence, one after the other. It was seen that the cartilage is laid down as a solid rod by about 17 days post-amputation, and that by about 20 days, it starts to be split up into its three elements. An X-ray study of the growth of digit regeneration together with autoradiography experiments were also carried out as a comparison to studies already undertaken on larger more proximal blastemas. It was shown that in fact the behaviour of digit blastemas is very similar to those of a more proximal origin. This fact, together with the advantages of its size, make the digit a very strong candidate for the further study of regeneration.


Ultrastructural localization of non-specific alkaline phosphatase during cleavage and blastocyst formation in the mouse.

The localization of non-specific alkaline phosphatase activity during cleavage and blastocyst formation has been investigated in the mouse by electron microscopy. The activity is detectable for the first time at the two-cell stage and is localized on the surface of the interblastomeric plasma membranes and on small cytoplasmic inclusions. It increases in the following stages, predominantly on the interblastomeric membranes, the outside membranes remaining devoid of reaction. From the four-cell stage on, small reactive grains are also observed in the crystalloid plates of the cytoplasm. At the morula stage, the plasma membranes of the inner mass cells are entirely marked by the reaction whereas the trophoblastic cells are polarized, with their inner surfaces positive and outside surfaces negative. At the blastocyst stage the enzyme is gradually eliminated from the membranes bordering the blastocoel and from the interblastomeric furrows of the trophoblast and primary endoderm. The significance of the differential localization of the enzyme is discussed, especially in relation to the differentiation mechanisms of the trophoblast and inner cell mass.


The onset of osteogenesis in the developing chick limb.

The pattern of the onset of osteogenesis in each of the skeletal elements of the developing limbs of the chick embryo is described using Alizarin-red-stained whole mounts. Grafting experiments where 6-day unossified cartilage rudiments are placed into 4-day host wings show the initiation of ossification to be a programmed event. Truncation experiments show this to be the case not only for the initial onset of osteogenesis, but also for each region of each element. These results are discussed in terms of morphogenetic events occurring in the early wing bud.


Permissive and directive interactions in lens induction.

The interactive events leading to lens formation and the developmental potentialities of the presumptive lens ectoderm were examined in vitro. The presumptive lens ectoderm of both mouse and chick embryos was capable of forming a lens even when isolated from the optic vesicle before the two tissues reach the stage of close association. This lens-forming bias can be released with favourable culture conditions and by various heterotypic mesenchymes. The same permissive, unspecific conditions or heterotypic tissues failed to trigger lens formation in trunk ectoderm. The directive effect of the optic vesicle was demonstrated in experiments where it was grown in contact with the trunk ectoderm. The latter developed distinct lentoid bodies synthesizing lens proteins. The origin of the lentoid was confirmed in interspecies combination of chick and quail tissues. It is concluded that lens formation is governed by a series of interactive events consisting of both directive and permissive influences.


Tissue specificity for incorporation of [3H]thymidine by the 10- to 12-somite mouse embryo: alteration by acute exposure to hydroxyurea.

Radioautograms from 10- to 12-somite mouse embryos labeled for 30 min in vitro with [3H]thymidine were examined for frequency and intensity of incorporation. Results from ten tissues showed that values ranged from 82% of nuclei with a mean of 16.6 grains for visceral yolk sac to 17% of nuclei labeled with a mean of 4.4 grains for epithelium of the anterior gut tube. Labeling in the ten tissues indicated (1) a tissue-specific spectrum of incorporation of [3H]thymidine, (2) close correlation between frequency and intensity of labeling within a tissue and (3) asymmetrical quantities of incorporation between right and left somatopleure. Treatment with hydroxyurea in vitro reduced the frequency of labeled nuclei by 85% to 12% of control values. Mean numbers of grains over treated nuclei, 3.3-4.6 grains, were well above background but were clustered below the low end of the control range. Tissues exposed to hydroxyurea showed (1) labeling of significant numbers of nuclei, (2) inhibition of labeling in selected tissues and (3) equalization of bilateral asymmetry in quantity (frequency and intensity) of incorporation in somatopleure. The selective reduction of thymidine incorporation and equalization of asymmetrical rates of proliferation may constitute mechanisms by which hydroxyurea causes abnormal morphogenesis.


The diencephalic course of regenerating retinotectal fibres in Xenopus tadpoles.

The normal retinotectal path in the diencephalon of Xenopus tadpoles is widely distributed in the form of a wedge of fibres extending from the central grey to the outer margin of the diencephalon. Regenerating optic nerve fibres were shown, by silver-staining and proline autoradiography, to follow an abnormal path up the extreme lateral edge of the diencephalon. Study of tadpoles at various stages of development, and of optic nerves allowed to regenerate for various periods, indicates that all new incoming optic fibres pass up the lateral edge of the diencephalon. The inner/outer order of the fibres in the normal diencephalon thus reflects the radial distribution of the retinal cells of origin.


Scanning electron microscopy of the developing chick anterior corneal epithelium.

The anterior corneal epithelium of the developing chick was observed with the scanning electron microscope at various stages of development. In the earlier stages, up to about 15 days of incubation, the cells are characterized by regular polygonal outlines and a proliferation of microvilli on the surface. The microvilli then begin to coalesce and flatten so that the surface is rather smooth by about 19 days of incubation. Just prior to hatching, however, the cells begin to round up and once again become covered by microvilli. The cells then lift off the surface and expose the underlying cells. After hatching, the surface cells lose the synchrony of development that characterized the embryo and are found in various stages of senescence. The cells eventually lose their regular polygonal outlines and the corneal surface takes on a patchwork appearance.


A comparative study of spermiogenesis in wild-type and T:t-bearing mice.

The results of a comparative ultrastructural study of spermiogenesis in T/tx, +/tx, +/T, C57BL/LJ, BALB/c and randomly breeding Swiss Albino mice are reported. The observations show that aberrant spermiogenesis occurs in males of all strains and genotypes and that the same specific types of abnormal spermatids are found in all of the males examined. No unique morphological defect which could be correlated with the increased transmission frequency of tx-bearing gametes can be found in males heterozygous for the tx allele.


A study of spermatozoan defects in wild-type and T:t-bearing mice.

A comparative light and electron microscopic study was done on cauda epididymal spermatozoa from +/tx, T/+, T/tx, C57BL/6J, BALB/c and randomly breeding Swiss Albino mice. The results show that all of the males contain abnormal spermatozoa and that all contain the same types of defective gametes. No unique defect was found which can be correlated with the increased transmission frequency of the tx-bearing allele.


Morphogenesis by dissociated immature rat testicular cells in primary culture.

Dissociated cells from immature (15-day) rat testes maintained in primary culture were shown to undergo morphogenesis. Dissociated cells (1-4 X 10(6)) were cultured in 2 ml medium NCTC-135 containing 10% rat serum at 32.5 degrees C under an air; CO2 atmosphere (95%:5%). During the initial culture period (1-3 days) the dissociated cells attached to the culture dish and formed a monolayer. After 4-5 days of culture, aggregates of cells formed at discrete foci within the monolayer; these structures averaged 50 micrometer in diameter and numbered 3-4 X 10(3)/dish. Within 5-6 days of culture some of these aggregates (2-3 X 10(2)) released their contact with the substratum. Histological examination of released aggregates indicated a more regular, tissue-like organization with increasing time in culture. Aggregates at earlier time periods (4-5 days) exhibited concentric rings of cell while by day 6 some aggregates exhibited a vesicular appearance with a single layer of columnar epithelium surrounding a fluid-filled lumen. The type of structure formed varied with plating density; at densities less than 2 X 10(6)/dish the structures were spheroid while at greater densities tubes were formed. Time-lapse observations indicated that spheres formed by movements of cells into an aggregating center while tubes formed by a rolling from the edge of the monolayer. The cells comprising the vesicle epithelium appeared to be predominantly one cell type as determined by light microscopy. These results therefore indicate that dissociated testicular cells have the ability to reform tissue-like associations in culture.


Neuronal adjustments in developing nuclear centers of the chick embryo following transplantation of an additional optic primordium.

Following transplantation of an additional optic primordium into the orbital mesenchyme of chick embryos of approximately 2 days of incubation age, the changes in cell number in the ciliary ganglion, accessory oculomotor and trochlear nuclei were studied at various stages of development. Cell counts were made at 1-day intervals from days 9 through 15 for ciliary ganglion, and from days 13 through 15 for the accessory oculomotor and trochlear nuclei. Cell counts for the ciliary ganglion on days 9 and 11 were similar on the operated and control sides which suggests that grafting of an additional optic primordium, and thus enlarging the periphery, is not involved in the control of proliferation. Comparison of the number of cells for the ciliary ganglia and the accessory oculomotor nuclei at days 13 and 15 showed an increase on the affected side ranging from 8 to 27%, and 9 to 33% respectively. We interpret this increase on the experimental side as a reduction in the number of degenerating cells that occur in normal development, as a result of an enlargement of the peripheral field of innervation. Three cases showed an increase in the number of cells in the trochlear nucleus ranging from 9 to 29%. This increase was attributed to an increase in the size of the superior oblique muscle of the operated side as determined by volumetric measurements. On the basis of the evidence we conclude that an enlarged periphery acts by regulating the level of naturally occurring cell death by reducing the amount of cell loss, leading to a corresponding increase in final cell number.


Cinematographical study of cell migration in the opened gastrula of Ambystoma mexicanum.

The migration of inner marginal cells was studied in the Ambystoma gastrula, using scanning electron micrography and time-lapse cinemicrography. Scanning electron micrographs of gastrulae which were fixed while intact revealed that the migrating cells have flattened lamellipodia at their anterior end and a rounded cell body, which can sometimes be seen to be attached to a neighbouring cell by a slender posterior process. Films of opened gastrulae showed actively moving cells, with the same features described above. Details of their movements are reported and discussed in relation to the mechanism of gastrulation.


DNA synthesis during the first stages of anterior regeneration in the polychaete annelid Owenia fusiformis (dedifferentiation and early phases of differentiation).

We have analysed DNA synthesis in early phases of regeneration in a marine Polychaete Annelid, Owenia fusiformis. The length and efficiency of the prereplicative phase was found to vary with the diurnal rhythm of activity of the animal; that is, it depends on the initial state of the cell population at the moment of the onset of proliferative stimulatin. When animals were operated on at 12 a.m., the duration of the prereplicative phase of the first cells stimulated to proliferate was found to be 12 h. The remaining cells entered the S-phase progressively in waves until the 3rd day following amputation when nearly 100% of the blastema cells were stimulated. At that time the cell-cycles of these dividing cells were found to be highly synchronized. Blastema differentiation takes place on the 4th day and is initiated by stomodeum formation. During the differentiation phase, DNA synthesis is restricted to small areas of the regenerating part. The system described is viewed as a new instrument for investigating the control of the cell cycle in synchronized and subsequently differentiating tissue cells.


Participation of cultured teratocarcinoma cells in mouse embryogenesis.

Mouse blastocysts were microsurgically injected with embryonal carcinoma cells from in vitro teratocarcinoma cell lines C17, C86, SIKR-OSB, and PCC3/A/I. The embryos were allowed to develop to term and the resulting offspring were analysed for chimaerism using coat colour markers and isozyme differences of the enzyme glucose phosphate isomerase. When injected into blastocysts, cell line C86 produced tumours in six of 74 animals born. The tumours were detected at birth and were poorly differentiated neuroectodermal teratocarcinomas. Cell line C17 gave 13 chimaeras in 77 mice born, five of which showed chimaerism only in normal tissues, mainly melanocytes of the coat and eye. The other eight chimaeras developed tumours. Seven of these developed in adult animals and were mainly fibrosarcomas. Cell line SIKR-OSB resulted in one normal chimaera in 44 mice born. Of 86 animals born following injection of cell line PCC3/A/1, there was one chimaera with a small tumour and three normal chimaeras. The levels of chimaerism were generally very low. The mice were test bred but with no evidence of germ line chimaerism. The karyotypes of all the cell lines were abnormal. How this and other factors such as cell cycle times might affect the incorporation of embryonal cells into the developing embryo is discussed.


Intrinsic rhythm and basic tonus in insect skeletal muscle.

The jumping muscle of orthopterous insects contains fibres that possess an intrinsic rhythm (IR) of slow contraction. The contributing fibres are generally synchronized, but as many as three or four pacemakers are present. The frequency, amplitude and duration of IR contractions fluctuate erratically over a 24 h period. Metathoracic DUM neurone bursts suppress IR for a few minutes. Other, unidentified dorsal neurones enhance its amplitude. In addition to IR, the extensor tibiae shows intrinsic basic tonus (BT). BT is relaxed for several s by low-frequency burst output from unidentified metathoracic dorsal neurones. DUM neurone bursts may enhance extensor BT, relax it, or leave it unaffected. The effects on IR of various regimes of activity in the slow extensor tibiae (SETi) and the common inhibitor (CI) axons were examined. CI affects IR when stimulated at frequencies above 2 Hz. It causes amplitude depression and reduced duration of individual IR contractions as well as increased frequency. At 30 Hz and above, CI completely suppresses IR. An enhanced IR contraction starts within a few milliseconds of the termination of a CI train. At low frequencies (below 10 Hz) SETi causes increased frequency and decreased amplitude of IR, with a depressed IR contraction following cessation of the SETi burst. At frequencies above 15 Hz the SETi-evoked contraction dominates tension development, though IR summates with it during the rising phase. In quiescent preparations not showing IR, SETi stimulation at 10 Hz often started up IR. Single SETi or FETi impulses can initiate an IR contraction, and cause altered phasing, with up to a quintupling of frequency. After a critical period has elapsed following the onset of an IR contraction, a single single impulse in any one of the three axons will terminate it abruptly. The early termination is followed by a reduced interval which is proportional to the reduced IR contraction time. The rhythm of accumulated readiness to go into an IR contraction is independent of the pacemaker rhythm that initiates the contraction.