The effect of cyclophosphamide on compensatory hypertrophy and some renal functions in rats.

Administration of 20 mg/kg cyclophosphamide to unilaterally nephrectomized rats for a period of two weeks significantly increased the ratio of kidney weight to total body weight. This rise is, however, accountable more by the decrease of total body weight than by weight increase of the kidney. The RNA-DNA ratio in the hyperttrophic kidney after cyclophosphamide did not differ significantly from that found in the hyperttrophic kidneys of controls. The results obtained show that in our experimental lay-out cyclophosphamide did not inhibit significantly the compensatory renal hypettrophy. After cyclophosphamide, the hypertrophic kidney produced urine with lower concentrations of endogenous creatinine, all osmotically active substances and potassium than found in controls.


[Adriamycin effects of PHA-stimulated lymphocytes].

The effect of adriamycin on PHA-stimulated lymphocytes is dose-dependent. An adriamycin concentration of 0.2 mug/ml reduces blast transformation and RNA synthesis as well as cell proliferation (DNA-synthesis). The lower concnetration of 0,01 mug/ml, which can be found inpatients for several hours after i.v. application, results only in a transitional inhibition of uridine nucleolar labelling. This inhibition of uridine nucleolar labelling appears more rapidly after adriamycin addition than that of thymidine labelling. Lymphocytes preincubated with adriamycin are effected similarly to lymphocyte cultured in the continuous presence of adriamycin.


Diabetogenic effect of oral diuretics in asymptomatic diabetes.

Ten patients with asymptomatic diabetes were given 40 mg furosemide, or 50 mg dihydrochlorothiazide, or 50 mg ethacrynic acid alternatively each for a week. Glucose tolerance tests were performed weekly. There was no significant change in the G.T.T. values during the test period. The result support the view that the "diabetogenic" effect of thiazides can not consitute a contraindication to the use of these compounds, as diuretics and the drugs under review probably do not differ significantly in this respect.


[Intravenous administration of doxycycline vibravenös in childhood--clinical and pharmacokinetic problems].

The paper describes special advantages of doxycycline, especially also in comparison with other tetracyclines, the possbile side-effects of the preparation, and the various ways of application-under special consideration of the pathogenetic spectrum. Pharmacokinetic examination were carried out in eight permature babies, nine new-born, eight normal babies, and in two groups of school children, comprising 7 and 8 test persons each. During these examinations, the serum levels after 1, 6, 10, and 24 hours were evaluated. The values found showed levels in the range of bacteriologic efficiency as far as premature babies and new-born - after 24 hours and with 0.6 gamma/ml - were concerned. In older babies and school children, the values had decreased, after a single application, within 24 hours to 0.2 to 0.15 gamma/ml. However, it has been possible to achieve final values of about 1.5 gamma by applying the preparation twice, i. e. 2 x 2 mg/kg body-weight, within 24 hours. The complete course of elimination of Vibravenös was determined in 8 school children by blood sample taking after 5, 10, 15, and 20 minutes as well as after 1, 3, 6 hours. The values found herein were calculated by means of computer analyses. Half-life of doxycyclin in infantile individuals is subject to rather strong variations. Therefore, a higher dose than usual so far is recommended, viz 6 MG/KG B.W. as initial dose and 3 mg/kg b.w. as maintenance dose.


Cardiovascular side effects of tricyclic antidepressants - a risk in the use of these drugs.

Following the increasing use of tricyclic antidepressants, numerous side effects of these drugs are reported, e.g. ECG changes and cases of "sudden death". Because of the fact that haemodynamic studies in man and studies on the possible correlation between the structure of these drugs and their negative inotropic effect are lacking, we have investigated the influence on myocardial contractility of cat papillary muscle induced by impramine and dimetacrin as well as their desmethyl compounds (n = 42). Furthermore, the effects of i.v. administration of imipramine and dimetacrine on cardiovascular functions were investigated in 18 patients at cardiac catheterization. In addition, four patients were studied during ergometric exercise before and 45 min after injection of both drugs. Finally, fluorimetric determination of norepinephrine plasma concentrations were carried out in 8 patients.


Hypertonic balanced sodium solution in burn shock.

This study was designed to ascertain the most effective sodium solution for resuscitation after potentially fatal thermal injury. Solutions containing from 75 to 300 mEq/L of sodium were administered in various doses to mice subjected to a standarized scald. Their effectiveness was evaluated by comparison of the 24-hour mortalities, and also by the changes in body weight, urine and plasma electrolytes, etc. A wide range of solutions was effective; the optimal intake was approximately 22.5 mEq of sodium per kilogram of body weight. This was most efficiently given in a solution containing 225 mEq of sodium and 160 mEq of chloride per liter. Survival increased when the sodium to chloride ratio more closely approximated that oe plasma. Hypotonic solutions were less effective at all dosage levels.


Scintigraphical examinations in kidney trauma.

Thirty-three patients with acute renal trauma and 9 others sent to us for a specialist's opinion were examined radiologically and scintigraphically in the years 1971-1973. Scintigraphy proved to be an important complementary examination to the radiological procedures for the estimation of the impaired functional status of the damaged kidney. In half of the cases X-ray alone did not yield an exact assessment of the extent of the damage to the kidney as did the combination with scintigraphy and under some circumstances with isotope nephrography. Sometimes the X-ray picture allowed an under- or overestimation of the renal damage. Both radiological procedures are without risk and simple to carry out. In some instances this nuclear-medical complemntary examination can more exactly answer the question whether kidney trauma is involved.


Recurrent urinary infections: causes and prevention.

Despite the development of effective antimicrobial agents very little progress has been made in preventing recurrence of urinary infections and especially in pyelonephritis. Obviously then there are other factors which cause recurrence. The high incidence has caused recently many studies to be focused on this trouble. Some of the results will be briefly discussed.


Histopathology and bacteriology of postinfusion phlebitis.

Veins from patients with postinfusion phlebitis showed three types of histopathologic changes--mild, moderate and severe. Severe change was usually associated with thrombus formation. Bacterial culture of tips of devices used in infusion yielded only 10% of positive cultures. This supports the view that postinfusion phlebitis is probably due to an irritating foreign body type reaction rather than infection.


Hematoma of the iliacus muscle with femoral palsy.

A case of two simultaneous complications of anticoagulant therapy is presented: a hematoma strictly of the iliacus muscle causing femoral nerve paralysis and a retroperitoneal hematoma. The femoral nerve was trapped by the inguinal ligament to such an extent that its section was necessary to assure rapid and total nerve decompression. Evacuation and drainage of the hematoma was necessary. The favorable postoperative course encourages surgical management of this hematoma with nerve paralysis.


Hypoplasia renum: a comparative study of diagnosis, clinical course and management.

Twenty patients with hypoplastic kidney (12 men and 8 women, left kidney in 13 cases, right kidney in 7 cases) were observed between 1961 and 1971. The age of the patients ranged from 14 to 60 years. The anomaly predominated (65% of the patients) in the third and fourth decades of life; in this age the diagnosis of the true nature of the condition was often due to complications requiring examination. Carefully taken history and complete radiological survey are essential for the recognition. The value and characteristic features yielded by particular investigation are discussed. In 8 patients clincial diganosis was confirmed at operation. Most common complications of hypoplastic kidney included hypertension, lithiasis, hydronephrosis, pyelonephritis and periodic hematuria. In 9 pateints (4 women and 5 men) renal hypoplasia was associated with other anomalies of the genitourinary tract.


Prognosis of bladder carcinoma in patients treated with cystectomy.

Prognostic criteria for bladder tumors are the stage and grade of the tumor in the present series of 82 patients, in which all patients received the same treatment. These criteria are related and the combined evaluation increases the prognostic accuracy for the disease. In addition, the diameter and not the number of bladder tumors on primary diagnosis is an important prognostic sign. A significant number of tumors at the first clinical evaluation were apparently understaged and undergraded and to a lesser degree overstaged and overgraded as compared with cystectomy specimen evaluations. Despite the total cystectomy, even the patients with superficial bladder lesions, a significant number died from the bladder tumor and 1/4 of the patients had metastases at post mortem examination. The 5 year overall survival with total cystectomy was 40% and for 10 years 15%. Other adjuvant forms of therapy pre- and post-operatively must be assessed.


Retrocaval ureter with carcinoma of the renal pelvis: report of a case.

A case of retrocaval ureter associated with carcinoma of the renal pelvis has been presented. This is the 2nd such case out of 110 cases reported in Japan. It is suggested that long term stagnation of urine is the cause for such a high incidence of malignant neoplasm involving the renal pelvis.


Homograft of the small intestine. Metabolic and functional changes causing irreversible shock.

Homotransplantation of the small intestine is subject to high mortality in the first 48 hours after operation. We analyzed various causes of death, underlining the importance of postoperative shock, then developed an experiment in dogs with the object of improving the survival. We applied various therapeutic measures in order to reduce the factors which participate in the evolution of chronic, hypovolemic and toxic shock. We attempted to: (1) reduce the consecutive alterations to ischemia of the homotransplant during the non-perfusion period; (2) reduce the deleterious effect of retained fecal matter; (3) reduce the metabolic acidosis secondary to clamping of the great vessels; (4) acknowledge, analyze and correct alterations in fluid and electrolyte balances; (5) correct the blood volume; and (6) prevent infection. With these measures we have increased the survival rate.


Bone marrow examination as a diagnostic tool in carcinoma of the prostate.

155 patients with a newly discovered carcinoma of the prostate were investigated for the presence of bone metastases. Straight X-ray (conventional X-ray) revealed such secondary in 38 cases and bone marrow examination in 20. Three patients with a normal X-ray picture nevertheless showed cancer cells on bone marrow examination. The authors consider bone marrow examination as a valuable complement to the routine invedtigation of the patients with carcinoma of the prostate.


Autoregulation of renal circulation in mannitol-loaded dogs.

Renal haemodynamics and autoregulatory behaviour of the renal vessels have been investigated in mannitol-loaded dogs both for free-flow and for stop-flow conditions. Arterial pressure has been decreased by aortic clamping. For free-flow conditions: (i) relative constancy of RBF and GFR are well preserved in the entire autoregulatory pressure range, i.e., over 80 mm Hg arterial pressure; (ii) decreased GFR is due to enchanced intratubular pressure; (iii) autoregulation is connected with a sharp rise in afferent resistance, accompained by a passive decrease in efferent resistance. For stop-flow conditions: (i) enchancement of total vascular resistance is due to an increase in the passive resistance of the postglomerular vessels; (ii) afferent resistance drops to minimal values as casused by the relaxation of the corresponding arterioles; (iii) autoregualation is abolished: pressure-flow relations are linear over the entire arterial pressure range examined.


Reconsideration of split kidney function tests in hypertension: a new technique.

The role of the split kidney function tests in the diagnosis of renal hypertension is reviewed, and a new technique is described which is designed to diminish the number of false negative results sometimes encountered in unilateral pyelonephritis and segmental renal arterial stenosis. Split kidney function tests still have an important role in diagnosis of renal hypertension, particularly when the results of other investigations are equivocal and when facilities for differential renal renin assay are not available.


Local antibody formation within the eye: a study of immunoglobulin class and antibody specificity.

Primary immunogenic uveitis was induced in the rabbit eye with a single injection of antigen into the vitreous, and secondary booster uveitis responses were induced two months later by intravenous administration of the same antigen. The distribution of immunoglobulin classes and the specificity of the antibodies produced were assessed early and late in the primary response and early and late in the secondary response, and were compared with the analogous responses in the spleen and regional lymph nodes. At each of these stages of intraocular antibody response, IgG formation was higher and IgM formation lower than that seen in organized lymphoid tissues, while the proportion of IgA-forming cells was similar to the low levels usually found in the spleen. A significant proportion of IgA-forming cells was found in the perilimbal conjunctiva, and even greater levels in the lacrimal glands. At each stage of the response, the proportion of immunoglobulin-forming cells making antibody specific for the inciting ovalbumin antigen was surprisingly low, reaching only seven per cent during the late primary reaction and 18 per cent during the late secondary reaction.


Effect of ocular pressure on choroidal circulation in the cat and Rhesus monkey.

Using the heated thermocouple principle to monitor blood flow-rate in the choroid of the anesthetized cat and Rhesus monkey revealed that elevation of ocular pressure reduces blood flow-rate in the choroidal circulation. The magnitude of this effect at varying levels of ocular pressure led to the conclusion that the vascular bed of the choroid in these experimental animals is a passive one without evidence of active regulation.


Systemic aspirin and indomethacin do not prevent the response of the monkey eye to trauma.

The stability of the blood-aqueous barrier of the monkey eye was challenged by three different methods: anterior chamber paracentesis, intravitreal shigella endotoxin, and subconjunctival arachidonic acid. Systemic aspirin and indomethacin were ineffective in stabilizing the blood-aqueous barrier in all three of these systems.


Vitreous structure, IV. Chemical composition of the insoluble residual protein fraction from the rabbit vitreous.

Analysis of the structural proteins in the rabbit vitreous showed that the hydroxyproline content was 3.1 per cent w/w compared to a value of 10.9 per cent w/w for equivalent samples obtained from cattle. In contrast to the discreet fibers in bovine vitreous, the rabbit constituents occur as an aggregate of fibrils with a diameter of 15 to 20 å. The amino acid and carbohydrate composition was similar to vascular basement membrane and isolated fractions contained significant amounts of palmitic and stearic acids. The data indicate that the variability of vitreous structure in different species is not only quantitative, but also qualitative. It is suggested that in the rabbit the structural proteins may be derived primarily from the atrophied hyaloid system and that little, if any, secondary vitreous formation occurs in this animal.


Calculation of the optical power of intraocular lenses.

A rather simple clinical approach has been used to derive formulas necessary to calculate the power of pupillary intracameral prosthetics and these have been applied in 150 eyes. In 136 eyes, the postoperative measurements were within one diopter of preoperative calculations.


Kinetics of corneal epithelial regeneration. II. Epidermal growth factor and topical corticosteroids.

The kinetics of rabbit corneal epithelium regeneration were studied to determine if topical corticosteroid has an adverse effect on corneal epithelial wound healing, and if epidermal growth factor (EGF) can abrogate any adverse effect of topical corticosteroid. Healing of standardized 7 mm. central corneal epithelial wounds was determined by serial standardized color photography of the flourescein-stained defects and planimetry of the projected photographs. It has been found that topical application of 16 drops per day of vehicle or Decadron decreased the epithelial healing rate, as compared to saline drops four times daily. Decadron 0.1 per cent given hourly (16 drops daily) was no more detrimental to corneal epithelial healing rate than the vehicle similarly applied. EGF exhibited no capacity to alter the corneal epithelial healing rate when hourly drops of either the vehicle or Decadron 0.1 per cent were given. Under the conditions of these experiments, no adverse effect on corneal epithelial healing rate could be attributed to Decadron 0.1 per cent.


[Differential diagnosis of granulomatous skin diseases].

The case histories of two female patients with granulomatosis disciformis and necrobiosis lipoidica are reported. Widespread skin manifestations, also in face and neck, with peculiar anular lesions complicated the differential diagnostic discrimination from sarcoidosis. The aspects of the cases and their progress are discussed in regard to the necessity of permanent checking of diagnostic preconditions during therapy.


A theoretical analysis of selected factors important to health education strategies.

Based on the theoretical work of Dulany and Fishbein, two major problems for understanding health behaviors were delineated: (1) the identification of those variables that determine an individual's intention to perform a health behavior; and (2) the extent to which these intentions are predictive of behavior. An analysis of factors affecting the relation between health intentions and behavior was presented and its implications for health education discussed. A social psychological model specifying two major determinants of behavioral intentions was contrasted with the Health Belief Model.


The measurement and utility of the opinion leadership concept for family planning programs.

The objectives of family planning educational programs often include information diffusion as well as attitude and behavior change within a target population. This paper suggests that working with opinion leaders might be one possible means of fulfilling these objectives. But in order to work with opinion leaders, it is necessary first to identify them. For family planning studies, the operational indicators used in past studies do not appear to be adequate. These indicators do not accurately identify persons who will take an opinion leadership behavior in the future, do not measure knowledge by the opinion leader, do not distinguish positive from negative opinion leaders, and do not take account of the bi-directional flow of information and advice both to and from the opinion leader. Drawing upon data from a family planning study in Baltimore, various examples for inadequate opinion leadership indicators are given. The paper suggests the need to revise these indicators and then outlines a simple and inexpensive program that might be used to channel the energies and activities of family planning opinion leaders towards the fulfillment of program objectives.


Simulation of human behavior: possibilities for public health education.

Three levels of computer simulation of individual and aggregate human behavior are examined and applications to health education are reviewed. General implications of this use of computers for the training and future role of public health educators are suggested.


Values clarification and the cardiac patient.

This exploratory study tested the feasibility and potential of values-clarification methods in patient education with 20 chronic heart patients participating in the cardiac classes of a university medical center. Strengths and limitations of the methods were identified, with greater feasibility and responsiveness demonstrated in patients between 51 and 60 years of age, those who had accepted their cardiac problem, and in home visits rather than clinical settings.


Improved oral health of schoolchildren of 16 communities after 8 years of prevention. II. Findings in different types of caries predilection sites.

Details of the decrease of DMT experience from 1963/64 to 1971/72 attained with the aide of the "Caries-Preventive Program" in 16 communities were investigated. The number of extracted molars decreased sharply, while the number of extracted premolars increased slightly. These shifts and a slightly later eruption of premolars did not materially affect the validity of overall DMF counts. Findings in first molars indicated long-term persistence of the lowered DMF experience. Fissure and pit caries of molars was reduced by 24 to 27 percent. Caries on free smooth surfaces of molars and on approximal surfaces of anteriorteeth showed decreases by 76 to 82 percent. Dentinal radiolucenices observed on lateral bite-wing radiographys were reduced by 47 to 52 percent. When the small radiolucencies confined to the enamel were included in the DMFS count, the reduction ranged between 23 and 27 percent.


The gingivitis fluorescein test in recruits.

The average individual status of gingival inflammation was evaluated in two groups of 39 and 47 subjects by means of the Gingivitis Fluorescein Test (GFT) and the Sulcus Bleeding Index. The subjects of the test group received a prophylaxis and hygiene instructions which were effective in reducing the gingivitis after 12 days. However, the reduction was not paralleled by a simultaneous decrease of fluorescein recovered in mouthwashings. The oral hygiene of the control group's subjects was not altered and examinations were performed after 7 days. In both groups the average SBI-score did not exceed 1.2 in all examinations. The fluorescein content of the mouthwashings was approximately 10 times reduced when compared with previous findings. No correlation was found between the amounts of fluorescein in mouthwashings and the severity or extent of the clinically assessed gingival inflammation.


Effect of enamel solubility reducing agents on erosion in the rat.

Three experiments performed on Osborne-Mendel rats tested the effects on erosion of the topical application of aluminum, cerium and titanium salts as well as sodium fluoride and sodium mono-fluorophosphate. In two experiments the compounds were applied during the erosion period and in a third trial, the test substances were applied prior to exposure to the erosive agent which was fermented apple juice. While cerium had no significant effects on erosion, aluminum fhloride and titanium chloride significantly increased the severity of erosive tooth destruction. Only sodium fluoride and sodium mono-fluorophosphate were effective in preventing erosion.


Scanning tooth surface reflectometer.

A method for tooth surface lustre measurements with a scanning reflectance sensor system is described. A fiber optic light beam of high intensity is projected onto the labial tooth surface. The reflected light at position X is conducted through the same fiber optic to a photodiode, amplified and recorded on an X-Y recorder. Position X is measured by a potentiometer in the rotation center of a rod to which the fiber optic head is attached and which can be moved parallel to the arcade of anterior teeth to be measured. The experimental system allows the assessment of differences in light reflection caused by light scattering resulting from roughened enamel surfaces and by stains.


Reflectometry and micromorphology of polished, etched and repolished teeth.

Labial enamel surfaces of anterior teeth were polished, etched for thirty seconds with acid and then repolished by manual brushing with three different abrasive pastes for 10, 15, 15, 20, and 20 seconds respectively and finally for a 60-sec brushing with a dental engine. Before etching and following each paste treatment, the light reflection of the surfaces was measured with the scanning tooth surface reflectometer of GABATHULER. The reflectance values were compared with the microscopic tooth surface texture. Reflectometric findings were similar under in vitro and in vivo conditions. There were differences among the pastes in restoring maximum lustre of dull etched enamel, but not in polishing intact tooth surfaces.


Normal values of immunoglobulins in premature and in full-term infants, calculated as percentiles.

Immunoglobulin values were determined in carefully selected healthy, normal children of different gestational and chronological ages. Criteria for "normality" were eutrophy (length, weight, head circumference) and absence of obvious malformation, infection or other disease. Immunoglobulin concentrations were measured in radial immunodiffusion, calibrated by a standard serum according to WHO recommendations. Since the distribution patterm of the individual values was found to be asymmetric in certain age groups, percentiles were calculated. They represent a physiologically more meaningful pattern than the arithmetic mean with standard deviation. Especially at the critical chronological age around 3 months the low values are closer together and the high values wider spaced than is the case with the standard deviations. In premature infants the transplacentally acquired IgG supplement is reduced in inverse relation to the duration of gestation. However, the IgG levels of all prematures equal those of term babies at the chronological age of 14 weeks. IgM can, in contrast, be adequately synthesized by all age groups within the first week of life.


[Cow's milk protein intolerance in childhood. Review of 30 cases].

Retrospective clinical study of 30 cases of cow's milk protein intolerance with a long term follow-up (3-141/2 years) in 22 cases. The onset of the disease is usually in the first 6 months, following a short exposure to cow's milk proteins. A later onset is also possible, particularly following an intestinal infection which seems to favor the sensibilisation. Usually the digestive disturbances predominate and are often associated with respiratory, cutaneous and other general problems (especially unexplained prolonged fever). In about half the cases, laboratory studies reveal signs of exsudative enteropathy or generalized malabsorption with lesions of varying severity of the jejunal mucosa. Clinical observation and investigation allows us to divide the patients into three groups according to different manifestations: 1. acute anaphylactic, 2. chronic and benign (colitis), 3. chronic and severe, with accompanying malnutrition and intestinal malabsorption. This last category leads occasionally to diagnostic difficulties in distinguishing it from coeliac disease. Whatever manifestations encountered, the disease is usually transitory, and disappears between the age of 2 and 21/2 years, but can also persist for a much longer time. The long-term follow-up study showed complete catch-up growth, absence of further gastro-intestinal problems, and a low incidence of other allergic diseases (18%).


[Improvment of survival in cystic fibrosis patients from 1962 to 1971].

The survival rate of 42 patients with cystic fibrosis diagnosed during the five year period before institution of full prophylactic aerosol, mist tent and postural drainage therapy in 1967 was compared with that of 32 cases diagnosed in the five following years. The mean survival rate of the latter group was 81%, 81% and 73% at 1, 2 and 3 years respectivly, compared with 64%, 59% and 57% in the former group. The main difference was due to the significantly improved survival rate of cases diagnosed during the first year of life.


[Hemangiomatosis of the liver in infants: Diagnosis and treatment].

The authors present 7 patients with hemangiomatosis of the liver together with about 100 cases reported in the literature. 6 of 7 patients survived; 4 with supportive treatment only. Follow-up is from 2 to 12 years. Hepatomegaly, heart failure and cutaneous angiomas constitute the classical clinical triad. Arteriography is the best method to diagnose this lesion, and biopsy can thus be avoided. Clinical features and histological examination of these benign vascular tumors seem to confirm the theory that hemangioendothelioma and hemangioma represent only two different developmental stages of one disease. These lesions can regress spontaneously if left alone. Despite contrary prevailing opinion the conservative treatment is recommended as the first choice of the clinician.


Isolated glucocorticoid insufficiency.

Two cases of isolated glucocorticoid insufficiency or congenital adrenocortical unresponsiveness to ACTH-a variant of adrenocortical failure without mineralocorticoid insufficiency-are presented. Familial incidence was present only in case 1 since two of the siblings died after convulsions, possible related to hypoglycemia. The pathology specimens of one sibling were available for review showing complete lack of the fascicular zone and degenerative changes in the adrenals and evidence of increased ACTH secretion in the pituitary. In the patients who were given substitution therapy with hydrocortisone, studies of plasma renin and aldosterone revealed impairment of plasma aldosterone response to salt restriction, orthostatism and furosemide-induced diuresis combined with postural change. We conclude that in some cases of isolated glucocorticoid insufficiency, impairment of mineralocorticoid function may gradually develop, which is in contrast to the assumption of a congenital defect in the action of ACTH.


Cytochemical response of kidney, liver and nervous system of fluoride ions in drinking water.

Morphological and cytochemical studies on the squirrel monkey have been made after maintaining the sujects on pure distilled water and fluoridated distilled water for 18 months with the objective of determining the effect of fluoride on the activity of some hydrolytic and oxidative enzymes in the kidney, liver and nervous system. Daily water intake by individual animals was measured over the final 10 months of the animal's exposure to 0,1 and 5 ppm fluoride. Water consumption was considerably higher in the animals on higher fluoride intake. Whereas the nervous system remained totally unaffected by this experimental procedure, the liver showed a slightly enhanced acivity of Krebs citric acid cycle enzymes. The kidneys, however, showed significant cytochemical changes, especially in the animals on 5 ppm fluoride intake in their drinking water. In these animals, the glomeruli showed an increase in the activity of acid phosphatase and the enzymes belonging to the citric acid cycle and the pentose shunt, whereas lactate dehydrogenase, a resentative of the anaerobic glyoclytic pathway, remained unchanged or only slightly changed. These observations suggest that fluoride in concentrations as low as 5 ppm interferes to some extent with the intracellular metabolism of the excretory system.


The occurrence of the cell type containing a specific monoamine in the taste bud of the rabbit's foliate papila.

The fluorescence histochemical examination on biogenic amines of the rabbit's foliate papilla revealed that a specific monoamine exhibiting an yellow fluorescence was present in a certain cell type of taste buds. The fluorescence had the emission maximum at 520 mmu and faded rapidly under the influence of the UV-irradiation. The green fluorescence of adrenergic nerve had the emission maximum at 480 mmu and was fairly stable upon the UV-irradiation. The yellow fluorescence disappeared completely following reserpine treatment, while it was markedly enhanced by nialamide treatment. From the observations, it is suggested that certain taste bud cells of the foliate papilla contain a biogenic monoamine, probably 5-hydroxytryptamine (serotonin).


A method for the comparison of morphometrical data on skeletal muscles in young rats of different ages and body weight.

Training affects the properties of skeletal muscles as well as the body weight. Furthermore, the muscle weight and the cross-sectional area of the muscle fibers are related to the body weight. A method is therefore described which eliminates the influence of the body weight on the properties of skeletal muscles and thus allows the real training effects to be studied even if the animals to be compared are of different body weights. It is suggested that this method is useful also for morphometrical studies on organs other than muscle and on experimental situations other than training, e.g. for studies on growth.


The development of alkaline phosphatase in trichinous muscle.

The development of alkaline phosphatase during invasion and encystment of Trichinella spiralis in rat skeletal muscle fibres was studied at the ultrastructural level. On day 14 after infection, the enzymatic activity is found in proliferating parts of the T-tubular system and in parts of the plasmalemma. In cells, in which a strong hyperplasia of this system is noted. AlPase is present in the abundant network of stratified and concentric membranes from which a large number of pinocytic vesicles arise. From day 50 till 1 year after infection the enzyme activity was invariably present in the matrix surrounding the larvae and was confined to the enormous amounts of cytoplasmic membranes. The possible functional significance of this enzyme in the matrix, in view of its peculiar localization in the immediate vicinity of the parasite, is discussed. In the presence of 0.1 mM of the levamisole analogue, compound R 30402, which is a stereospecific inhibitor of AlPase, the activity is completely lost.


Electron microscopic demonstration of cell surface carbohydrates by means of peroxidase and ferritin complexes of the Lens culinaris lection.

The use of Lens culinaris lectin for electron microscopic detection of D-mannose,- D-glucose and N-acetyl-D-glucosamine like sites on tumor cells, erythrocytes, erythrocyte ghosts, cultured rat liver cells and various tissues of mice is demonstrated. In addition to Lens culinaris lectin-peroxidase reaction (LeL-po reaction) the preparation of active Lens culinaris lectin-ferritin conjugate are described and the specificity of cytochemical reactions are demonstrated. Furthermore experiments by immuno freeze-etching are reported for topological analysis of the lectin receptors.


X-ray microanalysis on the thyroid follicle of the hagfish, Eptatretus burgeri and lamprey, Lampetra japonica.

Intracellular dense bodies, cytoplasmic matrices, and luminal colloids in the thyroid follicle of cyclostomes, hagfish and lamprey were examined to identify the distribution of iodine using an energy dispersive X-ray microanalyzer attached to a scanning transmission electron microscope. High level of iodine was detected only in the large dense body of the hagfishes, while it was too slight in quantity to detect by this method in the cytoplasmic matrix as well as in the luminal colloid. In the adult lamprey thyroid, an appreciable amount of iodine was detected in a few large dense bodies. In mice and rats, it is very hard to detect iodine in the luminal colloid, intracellular colloid droplet, and in the lysosomal dense granule by this method, though these structures have been well known to contain a fairly large amount of iodine which is combined with thyroglobulin. These facts mean that intracellular dense bodies in the thyroid follicular epithelium of the cytoclostome, especially of the hagfish have an extremely larger amount of iodine. These bodies are considered to be secondary lysosomes or residual bodies containing reabsorbed colloid materials which are highly condensed.


Treatment of tetanus in the horse by injections of tetanus antitoxin into the subarachnoid space.

In 40 horses with tetanus, large doses of tetanus antitoxin (TAT) were injected into the subarachnoid space. In all the horses that recovered, the disease stabilized immediately after the injection. The results (77.5% recovery) were much better than in a previous series of horses with tetanus (50% recovery), in which TAT was injected either intravenously, intramuscularly, or in the epidural space.


Ocular changes in a horse with gutturomycosis.

Recurrent epistaxis and locomotor and visual disturbances leading to blindness in a 7-year-old gelding appeared to have resulted from a spreading fungal granuloma of the guttural pouch. The inflammatory area extended to the intracranial segment of the right optic nerve and to the region adjacent to the optic chiasma. Microscopically, changes indicative of multiple foci of ischemic infarction were noticed in the retina, optic nerves, optic chiasma, and optic lobe. The profusely growing fungal elements in the guttural granuloma had the morphologic characteristics of an Aspergillus sp.


Measles vaccine in dogs: efficacy against aerosol challenge with virulent canine distemper virus.

Fifty young Beagle pups were used in studies on the efficacy of measles virus vaccine in providing protection against virulent canine distemper (CD) virus given intranasally. Among 29 dogs vaccinated with measles virus vaccine and subsequently exposed to virulent CD virus, 1 died, 7 developed relatively severe signs of CD, 15 had mild signs of distemper, and 6 remained clinically normal. Of 15 unvaccinated dogs similarly exposed to virulent CD virus, 11 succumbed to distemper. Six pups vaccinated with modified live-virus (MLV) CD virus vaccine remained clinically normal following immunity challenge.


Aspirin dosages for the dog.

Aspirin dosages calculated from published pharmacokinetic data were tested in 3 male and 3 female Basset Hounds. Emesis occurred frequently after dosing at the rate of 50 mg/kg of body weight, a dosage that would be required for a convenient 12-hour dosing interval. A dosage of 25 mg/kg every 12 hours avoided emesis but did not maintain serum salicylate concentrations within the desired range of 10 to 30 mg/100 ml. A dosage of 25 mg/kg every 8 hours resulted in serum salicylate concentrations varying from 12.5 to 17.8 mg/100 ml. It was concluded that a maintenance dosage of 25 to 35 mg/kg every 8 hours in optimal for the dog, based on extrapolation of data obtained in man.


Infectivity of bovine adenovirus type 5 recovered from a polyarthritic calf with weak calf syndrome.

Bovine adenovirus type 5, isolated from newborn calves with a polyarthritic disease known as "weak calf syndrome" caused a mild, self-limiting illness in susceptible calves. The induced illness was characterized by marked pyrexia and occasionally by mild diarrhea. It was concluded that the virus may contribute to morbidity and mortality associated with the weak calf syndrome by adding to the stress and debilitation caused by cold wet weather and by bovine viral diarrhea (BVD) virus, which has also been isolated from tissues of calves affected with weak calf syndrome.


Nasolacrimal duct anomaly in calves.

Supernumerary openings of the nasolacrimal drainage apparatus were found in 13 Brown Swiss calves. The cause of the anomaly was not determined but was assumed to be similar to that in man.


Equine granulosa cell tumors.

Unilateral ovariectomy was performed on 3 mares affected with granulosa cell tumors. Tumor fluid in each mare was found to contain estrogen, testosterone, and progesterone. In 2 mares, preoperative blood plasma concentrations of these hormones were comparable to those of a series of clinically normal mares. The other mare, which had a history of aggressive, masculine behavior, had higher testosterone content in the tumor fluid and in the preoperative blood sample. After surgical removal of the tumors, each mare developed follicles and ovulated with the remaining ovary. Each was eventually bred and 2 conceived. The probability of metastasis of these tumors in mares appears uncertain. Data from other species suggests a guarded long-term prognosis may be justified.


Swine tuberculosis in South Dakota.

Mycobacteria were isolated from 195 of 200 lesions in lymph nodes identified as granulomatous by meat inspectors at 4 abattoirs in South Dakota. Mycobacterium avium serotypes 1 and 2 accounted for 89% of the isolants. Mycobacteria were isolated more frequently from lesions than acid-fast bacilli were observed on microscopic examination (P less than 0.001). The frequency with which mycobacteria was isolated was similar to the occurrence of granulomatous lesions. The numbers of the various kinds of mycobacteria isolated at each of the 4 abattoirs and for the 3 meat inspection disposition classes were not significantly different.


Posthitis in Angora wethers.

Posthitis was diagnosed as an economic problem of Angora wether goats. Affected goats had a scabby or ulcerated prepuce, with a distorted or pinhole preputial orifice. Some goats were able to urinate only by excessive straining. Cultural examination revealed a Corynebacterium sp capable of hydrolyzing urea, similar in all respects to the organism associated with a similar problem with Merino wethers in Australia. Necessary predisposing factors are considered to be a castrated animal consuming a high protein diet and infection with the urea-hydrolyzing organism.


Evaluation of Harleco CO2 Apparatus: comparison with the Van Slyke method.

The usefulness of the Harleco CO2 apparatus as a measure of the blood alkali reserve was evaluated by determining plasma CO2 (bicarbonate) content in the bovine and canine species. The method was found to be inexpensive, simple accurate, and comparable in all respects to the Van Slyke method for making this determination.


Protothecosis with ocular involvement in a dog.

An 8 1/2-year-old Collie dog was referred for evaluation of chronic diarrhea as well as sudden blindness and leukokoria of the right eye. An organism morphologically similar to Prototheca sp was recovered from the subretinal fluid and was found at necropsy in the eyes, gastrointestinal tract, lungs, lymph nodes, kidneys, heart, abdominal fat, and omentum.


Exophthalmos secondary to zygomatic adenocarcinoma in a dog.

An 8-year-old Labrador Retriever developed unilateral exophthalmos over a 1-year period. Contrast radiography, surgical exploration, and histologic examination revealed the cause to be an adenocarcinoma arising from the zygomatic salivary gland or duct.


Hygroma of the elbow in dogs.

Two serious complications-infection and skin ulceration-have been associated with the treatment of elbow hygromas in large and giant breed dogs. Infection in 3 dogs followed the injection of a corticosteroid preparation into the cavity of the hygroma. Skin ulceration developed in 6 dogs following excision of the hygroma and wound breakdown. These skin ulcers were eventually closed by a simple reconstructive procedure. It is recommended that hygromas should not be treated by aspiration and injection of corticosteroid preparations, or by excision. A simple drainage procedure was used successfully in the treatment of 18 hygromas.


Anomalous portosystemic anastomoses associated with chronic hepatic insufficiency in six young dogs.

Chronic hepatic insufficiency due to anomalies of the portal venous system was diagnosed in 6 young dogs. The disorder was characterized by a variety of abnormal central nervous system signs or ascites, or both. Laboratory findings were characteristic of chronic, generalized hepatic dysfunction. The diagnosis was established by angiographic studies of the portal venous system. Of the 6 dogs, 3 died, 1 was euthanatized, and 2 are still alive and require medical management for ascites.


Megestrol acetate for estrus postponement in the bitch.

Megestrol acetate was given orally to 389 bitches in early proestrus, at a dosage of 2.2 mg/kg (1 mg/lb) per day for 8 days. Estrus was suppressed in 357 (92%) of the bitches. Additionally, 119 bitches in anestrus were given the drug at the rate of 0.55 mg/kg (0.25 mg/lb) per day for 32 days. Estrus was suppressed in 115 (98%) of these bitches. Adverse effects were minimal. Pyometra developed in 3 (0.8%) of the 389 bitches treated in early proestrus. The drug also was given to 19 bitches at the rate of 0.55 mg/kg/day for 32 days, regardless of the stage ofting at the 1st posttreatment estrus and 4 after mating at the 2nd posttreatment estrus. Litter size, success in rearing pups, and sex ratios were not significantly different from these factors in 53 litters from untreated bitches.


Phycomycosis in a dog.

Chronic vomiting in a 2-year-old dog was suspected to be due to a neoplasm of the stomach wall. During exploratory laparotomy, a lymph node from the pyloric area was examined microscopically. Inasmuch as neoplastic cells or evidence of metastasis were not found, all visibly involved tissue was removed surgically. A diagnosis of phycomycosis was then established by histologic evaluation of the tissue removed. It was concluded that diagnosis of this disease is important inasmuch as it may be treated successfully, in contrast to the situation with malignant neoplastic conditions, which it grossly resembles.


Nerve distribution in the metacarpus and front digit of the horse.

The nerve distribution to the digit of the horse was studied with the compound microscope in serial transverse sections of fetal limbs and plotted on life-size outlines of the horse's foot. It was learned that there is much variation in the topography of the branches of the principal nerves. There is no mirror-image nerve distribution on the 2 sides of the foot. The dorsal branch of the ulnar nerve does not extend below the fetlock. The communication between the palmar metacarpal nerves and branches of the dorsal branch of the digital nerves is only a crossing of nerves without exchange of fibers. The palmar metacarpal nerves usually do not innervate structures distal to the pastern joint. The innervation of the deep structures of the equine foot was tabulated.


Lag screw fixation of avulsion fractures of the second phalanx in the horse.

Avulsion fractures of the posteromedial eminence of the 2nd phalanx were repaired, using an ASIF cortex screw in 3 reining Quarter Horses. Within 9 and 11 months, respectively, 2 horses were sound and back in competition as reining horses. The other horse was sound for pleasure class showing at 7 months after surgery.


Lipiarmycin, a new antibiotic from Actinoplanes.  I. Description of the producer strain and fermentation studies.

The producer strain of the new antibiotic, lipiarmycin, is described.  The colony morphology, the presence of globose sporangia bearing motile spores, the absence of aerial mycelium and the presence of meso-DAP in cell wall, ascribe this strain to the genus Actinoplanes.  The pigmentation and morphological characteristics together with the cultural and physiological features distinguish this strain from all the described Actinoplanes species.  It is considered to be a new species for which the name Actinoplanes deccanensis nov. sp. is proposed.  Lipiarmycin is produced in an organic complex medium containing NaCl.  Production occurs at the end of trophophase and continues, though at decreasing rate, during isophase.


Microbial transformation of validamycins.

Alpha- or beta-Glucosidic linkage of validamycin was selectively cleaved by microbial hydrolysis and especially the conversion of validamycin C into validamycin A by the selective hydrolysis of alpha-glucoside linkage has important significance because validamycin C is considerably less active than validamycin A.  Semisyntheses of validamycins including a new validamycin, beta-D-galactosyl-validoxylamine A were carried out by microbial transglycosidation using validoxylamine A as a glycosyl acceptor.  D-[U-14C]glucose and [14C]validoxylamine A were highly incorporated into validamycin A by validamycin-producing Streptomyces hygroscopicus var. limoneus.


Microbial degradation of erythromycins A and B.

Growing cultures, as well as broken and lyophilized cells of pseudomonas 56 were found to degrade erythromycin A, and lyophilized cells inactivated erythromycins A and B. The enzyme system involved in this degradation was constitutive and the enzyme level in the cells could be increased about 8-fold when oleandomycin or erythromycin B was added to the growth medium. The ability of whole or broken cells to inactivate erythromycin A was completely lost when these preparations were boiled, and the erythromycin A-inactivating activity was localized in the cell membrane fraction. The lyophilized cells did not degrade oleandomycin, methymycin, tylosin, a mixture of leucomycins, josamycin, or maridomycin III.


Studies on the absorption, distribution and excretion of radioactivity after intravenous and intraperitoneal administration of 14C-methyl ester of amphotericin B.

Distribution and balance studies with carbon-14-labeled amphotericin B methyl ester (AME) were carried out in mice.  The radioactive AME was administered by either the intraperitoneal (i.p.) or intravenous (i.v.) route.  In the organ distribution study, the percent radioactivity accumulating in the lung of i.v. treated mice at 1 hour after administration was about 150 times greater than that observed when the intrapertinoneal route was used.  No accumulation of radioactivity with time was detected in the kidneys of either the i.v. or i.p. treated mice.  After 4 days, about 51% of the total radioactivity was excreted into the urine and feces of mice after i.v. administration, but only about 15% of the total radioactivity was excreted in the case of mice receiving radioactive AME by the i.p. route.  In the identification of the substances excreted in the urine, thin-layer chromatography (TLC), radioactivity, and bioautographic evidence suggest that there was no detectable de-esterification of AME to the parent compound in mice treated either intraperitoneally or intravenously with AME.


Sensitivity in vitro of leptospira to oxamicetin.

Oxamicetin was tested against 12 strains of parasitic leptospira each representing a different serotype and serogroup, and 8 saprophytic strains in liquid media. The results showed general susceptibility of parasitic leptospira being MIC's from 0.1 to 0.5 mug/ml. The MIC's against saprophytic strains were 10 similar to 40 mug/ml.


I. Isolation and characterization of the transformation products of maridomycin III.

Three transformation products of maridomycin (MDM) III, a macrolide antibiotic, by Streptomyces lavendulae were isolated by silica gel and alumina chromatography, and designated as spots 1 (starting MDM III), 2, 3 and 4, in the order of their decreasing Rf values on thin-layer chromatogram. By mass- and NMR-spectrometry and thin-layer chromatography, spot 2 was identified as 18-dihydro-MDM III, spot 3 as 4''-depropionyl-MDM III, and spot 4 as 18-dihydro-4''-depropionyl-MDM III. The relationship between starting MDM III and these transformation products were also discussed.


Isolation and characterization of mannopeptins, new antibiotics.

New antibiotics, mannopeptins A and B, were isolated from the fermented broth of Streptomyces platensis strain FS-351. Ferrous ion is essential for the antibiotic production, since no productivity was noted with media containing less than 0.11 mM ferrous ion and maximum production was achieved at a concentration of 1.8 mM. The antibiotics are basic glycopeptides with relatively high molecular weight and are similar to ristocetin and vancomycin but can be differentiated from them in view of their chemical composition and chromatographic behavior. The antibiotics were named mannopeptin after the glycopeptide containing mannose.


Cardiopulmonary responses to exercise in obese girls and young women.

A study of exercise performance was carried out in 17 obese girls and young adults. During submaximal steady-state bicycle exercise oxygen intake (Vo2) for a given work output (W) was raised in obese subjects but minute ventilation at a fixed carbon dioxide output, gas exchange, blood gases, and cardiac output at a given VO2 were similar to the values previously found for normals. In obese subjects high levels of VO2 for fixed W were also obtained on the treadmill but when these were standardized for body weight (unlike the bicycle test) it was shown that the obese girls and women exercised within the normal (expected) range of aerobic energy expenditure. During maximal performance the absolute VO2 max was the same in obese and nonobese subjects but for a given body weight, lean body mass, and leg muscle (plus) bone volume, VO2max was reduced by 23.8, 16.3, and 24.5% respectively, in the former group. It was concluded that obesity though having minimal affect on responses to submaximal exercise is nevertheless associated with a marked reduction in physiological performance at or near maximal effort.


Effects of training on the physiological responses to one- and two-leg work.

The effects of training resulting from one-leg exercise on a stationary bicycle ergometer have been studied. Seven subjects were habituated to one- and two-leg progressive exercise tests on 11 successive days and were then trained for 60 min-day-1 (30 min each leg) 3 times per wk for 5-6 wk at approximately 80% of their one-leg VO2 max. VE max increased (P less than 0.05) by approximately 14 1-min-1 and VO2 max by approximately 0.34 1-min-1 (+14%; P less than 0.05) in one-leg exercise. This latter increase was not, however, reflected in the two-leg VO2 max which only increased 145 ml-min-1 (4.7%). It was concluded that training is specific and in one-leg work the phenomenon is mainly peripheral in origin, but in two-leg work the limitation to maximal exercise is still provided by the capacity of the central cardiovascular system to transport oxygen to a given effective muscle mass.


Rabbit's ear in cold acclimation studied on the change in ear temperature.

The role of the rabbit's ear in cold acclimation was studied by varying the temperature of a climatic room in the range from -10 to +30 degrees C; The skin temperature in a nonanesthetized rabbit's ear showed a characteristic response to changes in ambient temperatures; plotting the ear temperature against the ambient temperature yielded an S-shaped curve. The mean ambient temperature corresponding to the inflection point on the S-shaped curve shifted significantly from about 13 degrees C to about 8 degrees C after cold acclimated of a group fed for 7 wk at -10 degrees C. The shift of the S-shaped curve after cold acclimation may not be due to the change in the norepinephrine sensitivity of the vascular beds of the ear: the effect of norepinephrine on the pressure-flow curve in the isolated rabbit's ear was almost unchanged between the control and the cold-acclimated groups. It is proposed that the shift of the inflection point gives a qualitative index of the acclimated state of the rabbit at a particular temperature.


Lung volume and interdependence in the pig.

The effect of lung volume on the mechanical interdependence between an obstructed sublobar region of lung and its surrounding tissues was investigated in intact and isolated pig lungs. Interdependence is arbitrarily defined as the effectiveness with which the linkage between the region and surrounding tissue mediates a tendency for inflation to become even whenever it is uneven. We found that when the volume of the surrounding lung (Vl) was high relative to the volume of the obstructed region (Vr), or when they were relatively equal at higher inflation states, interdependence decreased. When Vr was high relative changes in regional shape observed during even and uneven inflation states, we suggest that regional distortion and its effects on regional elastic recoil are important determinants of pulmonary interdependence.


Respiratory gas exchange ratio and prediction of aerobic power.

The Issekutz procedure for the prediction of maximum oxygen intake from the respiratory exchange ratio (R) has been evaluated on a diverse group of 308 subjects, including "whites" and Eskimos, men and women ranging in age from 16 to 65 yr. When applied to young white men performing 12 min of progressive step or treadmill exercise, the prediction procedure has a coefficient of variation of less than 10%, without systematic error. Unfortunately, the standard equation lacks generality, and erroneous predictions can arise from a change of test protocol, the use of a different exercise modality, or application to older subjects. If a brief exercise format is used, low R values may be reported during an early phase of relative hypoventilation. At a given metabolic loading, bicycle ergometry yields a higher respiratory minute volume than other modes of exercise. A heavy loading of one muscle group seems responsible, and the results is a high R value in submaximum effort. Aging is associated with a lowering of maximum blood lactate levels and thus maximum figures for R.


Role of peripheral and central chemoreceptors in the initiation of fetal respiration.

The relationship between fetal femoral arterial P02 and PC02 was evalulated in 13 fetal sheep with intact and denervated peripheral chemoreceptors. With intact chemoreceptors, a significant relationship was found between fetal Pa02 and PaC02 at the time of the first breath (Pa02 = 2.57 + 0.09 PaC02; r = 0.62, P less than 0.05)mfollowing bilateral carotid sinus nerve section (CSN) or total peripheral chemodenervation (TD), PaC02. Comparison of the intact, CSN, and TD blood gases at the time of the first breath demonstrated that a) severe hypoxemia stimulates fetal respiration even following total peripheral chemodenervation; b) fetal central chemoreceptors do not respond to PaC02; c) PaC02 acting via peripheral chemoreceptors has a minor modulating effect on the degree of hypoxemia required to initiate fetal respiration. At a PaC02 below 40 mmHg this effect is inhibitory, acting via the carotid body. At a PaC02 above 90 mmHg this effect is stimulatory, acting via both carotid and aortic bodies.


Effect of intrathoracic pressure on pressure-volume characteristics of the lung in man.

Quasi-static pressure-volume (P-V) curves in normal seated human subjects were determined with pressure at the airway opening (Pa0) set below (negative pressure), above (positive pressure), or equal to ambient pressure. Dynamic compliance (Cdyn) during controlled continuous negative pressure breathing (CNPB) was also studied. Quasi-static P-V curves at negative pressure were decreased in slope, reflected a decrease in total lung capacity, and intersected the P-V curve obtained at ambient Pa0. At positive pressure the P-V curves showed an increase in slope and an increase in total lung capacity. During CNPB a fall in Cdyn was found. The fall in Cdyn was rapid and persisted for the duration of CNPB. Cdyn promptly returned to control levels when Pa0 was adjusted to ambient pressure.


Influence of body position on pulmonary diffusing capacity in yound and old men.

Steady-state diffusing capacity (DLCOSS2), studied in healthy nonsmokers, was significantly higher in five old men when seated than when supine, but was unchanged in five young men. However, "corrected" for the increased ventilation, it decreased in the young--but not in the old--when erect compared with when supine. The change of DLCOSS2 in the young during the first 20 min when seated was related to a change of the fractional dead space ventilation (VD/VT)mThe old showed less venous admixture when seated than when supine, whereas VD/VT and regional ventilation-perfusion index of the lung bases was the same in both positions. The decrease in venous admixture was probably due to the closing capacity (CC) being less than the functional residual capacity (FRC) when seated. The elimination of closed off regions when seated made more pulmonary capillaries available for diffusion.


Maximal oxygen consumption test during arm exercise--reliability and validity.

The reliability and validity of a continuous progressive arm test, in which maximal 02 consumption (V02 max arm) is determined, were analyzed. Forty-one men (28.2 +/- 8.8 yr) performed the test twice. Eighteen additional men (22.6 +/- 5.6 yr) performed the arm test, as well as the treadmill run, in which maximal O2 consumption VO2max leg) was determined. The validity of the VO2 max arm test was computed, using VO2 max leg as a criterion for the individual's aerobic capacity. The reliability coefficients of VO2 max arm, VEmax arm, and HRmax arm were 0.94, 0.98, and 0.76, respectively, indicating a high reliability of the testmthe validity coefficient of VO2max arm was only 0.74. The regression equation of VO2max leg on VO2max arm was y = 24.4 + 0.9 +/- 4.4 (Syx). These findings indicate that, following the suggested protocol, the individual repeatedly uses the same muscles and does reach an all-out stage. However, different individuals apparently are aided by their trunk and leg muscles to different degrees, which lowers the validity of this test as a predictor of aerobic capacity.


Simulation of frequency dependence of compliance and resistance in healthy man.

The frequency dependence of effective compliance, Ceff, and resistance, Reff, are reproduced by means of a two- or four-compartment linear mathematical model with pleural pressure as a sinusoidal input. The model simulates the mechanical properties of lung parenchyma, alveolar gas, bronchial wall, and cheeks, as well as the distribution of gaseous resistances and inertances within the airways. Values, representative for a young healthy adult, are assigned to these various parametersmit appears from this study: 1) that the gas inertance produces a very marked increase of Ceff, noticeable already below 1 cycle/smto obtain a frequency independence of Ceff between 0 and 2 cycles/s, it is necessary to introduce a marked inhomogeneity in the model. 2) Such an inhomogeneity is realized by simulating a pleural pressure difference of 6 cmH2O between the compartments of the bialveolar model. It can be shown that this corresponds to a total pleural pressure difference of about 9 cmH2O in a model consisting of an infinite number of compartments. 3) The influence of the compressibility of alveolar gas and of mechanical properties of the bronchial wall and of the cheeks on Ceff and Reff is small or negligible.


Nonshivering thermogenesis and cold resistance in rats under severe cold conditions.

Following either chronic exposure to 6 degrees C, or outdoor winter exposure, or chronic treatment with tyramine rats were exposed to -40 degrees C and their oxygen consumption and colonic temperature monitored. Fall in body temperature with time of exposure followed a sigmoid curve which had an inflection point around 32.9 degrees C. Both the time required for body temperature to reach this point and hypothermic resistance defined as the total O2 consumed up to the inflection time were useful indices of resistance to severe cold; Three days before the cold tests, capacity for norepinephrine-induced nonshivering thermogenesis was measured in all animals by examination of their metabolic response to tyraminemthe magnitude of response to tyramine correlated well with hypothermic resistance only for those rats chroncally treated with tyramine. It is concluded that it is impossible to predict with any reasonable degree of confidence the cold resistance of a rat from its tyramine response. In cold-acclimated rats, factors in addition to norepinephrine sensitivity are significantly involved in cold resistance and deserve further studies.


Correlation between skeletal calcium mass and muscle mass in man.

The measurements of total body potassium (TBK) and calcium (TBCa) were made on 317 subjects by the techniques of whole-body counting and total-body neutron activation analysis (TBNAA), respectively. The TBK/TBCa ratios are constant for normals over the age range studied. The males have more cellular mass (TBK) per unit skeletal mass (TBCa) than the females, as indicated by their respective TBK/TBCa ratios, 0.122 +/- 0.008 (1 SD), and 0.100 +/- 0.007 (1 SD). In general, patients with various metabolic disorders tend to follow the physiological trend found in the normals. In a number of metabolic disorders, the loss of TBK was usually approximately 60% of that of the TBCa when expressed in terms of the predicted normal values. This suggests that the mechanism causing the loss of calcium in physiological and altered metabolic states simultaneously involves both the skeleton and its associated musculature.


Effects of mechanical loading and hypercapnia on inspiratory muscle EMG.

The electromyograms of the diaphragm and an external intercostal muscle were analyzed to see if the effects of hypercapnia on inspiratory muscle electrical activity could be distinguished from those of mechanical loading and to determine whether changes in inspiratory muscle electrical activity were a sueful measure of CO2 response during mechanical loading. Anesthetized dogs were studied: 1) during progressive hypercapnia without mechanical loading, 2) during flow-resistive and elastic loading at constant PCO2, and 3) during progressive hypercapnia and mechanical loading. Both mechanical loading and hypercapnia increased total inspiratory diaphragmatic and intercostal muscle electrical activity. However, inspiratory duration was increased by mechanical loads but reduced by hypercapnia. Because of these changes in inspiratory duration, the average rate of diaphragmatic electrical activity remained unaffected by mechanical loading before and after vagotomy but was increased by hypercapnia. In contrast, both hypercapnia and mechanical loading increased the average rate of intercostal muscle electrical activity. There was a greater increase in both total and average rate of intercostal muscle electrical activity during hypercapnia in the presence of mechanical loading than during unloaded breathing. However, the change in total and average rate of diaphragmatic electrical activity with PCO2 was unaffected by added mechanical loads. These results suggest that diaphragmatic but not intercostal muscle electrical activity can be used as an index of CO2 response even during mechanical loading.


Frequency and duration of interval training programs and changes in aerobic power.

This study was designed to ascertain whether 7- and 13-wk interval training programs with training frequencies of 2 days/wk would produce improvement in maximal aerobic power (VO2max) comparable to that obtained from 7- and 13-wk programs of the same intensity consisting of 4 training days/wk. Sixty-nine young healthy college males were used as subjects. After training, there was a significant increase in VO2max (bicycle ergometer, open-circuit spirometry) that was independent of both training frequency and duration. However, there was a trend for greater gains after 13 wk. Maximal heart rate (direct lead ECG) was significantly decreased following training, being independent of both training frequency and duration. Submaximal VO2 did not change with training but submaximal heart rate decreased significantly with greater decreases the more frequent and longer the training. Within the limitations of this study, these results indicate that: 1) maximal stroke volume and/or maximal avO2 difference, principle determinants of VO2max, are not dependent on training frequency nor training duration, and 2) one benefit of more frequent and longer duration interval training is less circulatory stress as evidenced by decreased heart rate, during submaximal exercise.


Specificity of autonomic influences on cardiac responses during myocardial ischemia.

A possible role of the autonomic nervous system in the left ventricular response to acute regional myocardial ischemia was sought in conscious dogs instrumented for measurement of left ventricular pressure, internal diameter, and aortic flow. Ischemia produced by occluding the left circumflex coronary artery caused tachycardia and reduced contractility. Changes during control occlusions were compared with those during occlusion.s after beta-adrenergic blockade, parasympathetic blockade, and combined sympathetic and parasymphatetic blockade. Beta-blockade did reduce the tachycardia and slightly reduced left ventricular diameter changes in response to coronary occlusion. Results obtained in animals following surgical cardiac sympathectomy indicated reduced tachycardia and no effects on other parameters. The principal effect of parasympathetic blockade was to augment the increase in end diastolic diameter during occlusion Right atrial pacing indicated this change was due to higher initial heart rates. Combined parasympathetic and sympathetic blockade did not alter inotropic responses to coronary occlusion. Results indicated that inotropic support due to changes in activity in autonomic nerves is not increased during acute occlusion of the left circumflex coronary artery.


Body temperatures during menopausal hot flashes.

Body temperatures during hot flashes were measured in a menopausal woman. Internal temperatures fell after each flash; lowest: rectal, 35.6 degrees C; vaginal, 35.6 degrees C; tympanic, 35.2 degrees C. Where sweating occurred, the skin temperature fell during the flash and rose after it. Finger and toe temperatures always showed a sharp rise at the onset of a flash with a slower fall after the flash. Only the cheeks showed additional temperature rises; maximum, 0.7 degrees C. The heart accelerated 13% at the onset of the flash but slowed immediately thereafter. The flash interval was sharply demarcated by undulations in the ECG baseline. There was never any premonitory sign of the imminence of a flash. A central excitatory state seemed to build up, perhaps by the accumulation of a chemical compound, but not of heat, which was explosively dischargedmthe thermal distress was probably evoked by vascular warming in the cheeks. Dabbing the malar prominences with cold water brought prompt relief.


Influence of starvation on the lung: effect on glucose and palmitate utilization.

The relative utilization of [U-14C]glucose and [1-14C]palmitate was examined in lung slices of male Long Evans hooded rats fed ad libitum and starved for 72 h. Food deprivation (72-h fast) significantly decreased [U-14C]flucose oxidation and incorporation into lung lipids. Glucose incorporation into phospholipid-fatty acid (53%) was, in proportion, more markedly reduced than into phospholipid-gluceride glycerol (33%), suggesting that glucose was being conserved for the formation of alpha-glycerol phosphate. (1-14C) palmitate utilization following fasting showed a significant 40% increase in oxidation, and a significant 16% increase in phospholipids, indicating preferential utilization of fatty acids over glucose. Phospholipid fatty acid composition, surface tension measurements and volume-pressure curves were not affected by fasting. Khe data indicate that glucose and palmitate metabolism are interrelated, and that the relative utilization of these substrates is changed to maintain essential lung lipids during an altered physiologic state.


Resistance of intrathoracic airways of healthy subjects during periodic flow.

The resistance and reactance of lower airways were measured as functions of the frequency and amplitude of periodic flow in three healthy subjects by relating flow, produced with a piston pump, to the difference between lateral tracheal and alveolar pressure, estimated plethysmorgraphically. Resistance consistently increased with frequency; reactance was small never exceeding resistance. This result cannot be explained by distortion of velocity profiles by inertia because, in long pipes, resistance increases only when inertial forces are large and reactance exceeds resistance. Theoretical analyses of airway resistance suggested that the results reflected inhomogeneity. In lung models which considered airway wall distensibility and inertial reactance of airways, resistance increased with frequency and inertial reactance was small. These results imply that in health, as in lung disease, resistance is determined by the distribution of resistance and reactance within the lung and is not simply the total resistance of the individual airways. As flow amplitude increased at constant frequency, flow-pressure relationships became distorted and resistance increased, due probably to motion of airway walls and further distortion of velocity profiles


Estimation of alveolar pressure during forced oscillation of the respiratory system.

A method for obtaining a continuous estimate of alveolar pressure (PAlv) during periodic flow is described; it was developed to improve the precision of measurements of airway and respiratory tissue impedance using the improved resolution of relatively high-frequency (approximately 5 Hz) singlas. The respiratory system was modulated with a piston pump, and lung volume and the volume change due to compression and expansion of alveolar gas were measured plethysmorgraphically; these signals and an analog divider were used to obtain a continuous solution of Boyle's law during flow. The plethysmorgraph was of the "flow" type; with it volume changes at frequencies up to 10 Hz and with rates of change up to 6 l/s were measured without amplitude or phase distortion. The method permits control of frequency and flow amplitude during PAlv measurement and calibration of PAlv in the absence of an active chest wall. However, it is technically complex.


A safe and fast-acting surgical anesthetic for use in the guinea pig.

Ketamine [dl-2-(o-chlorophenyl)-2-(methylamino)cyclohexanone] hydrochloride was used in conjunction with Acepromazine [10-3-(dimethylamino)-propyl]phenothiazin-2-yl-methyl ketone] Maleate to produce surgical depth anesthesia in guinea pigs. In tests with 97 animals, an intramuscular injection of 44 mg/kg ketamine hydrochloride plus 2 mg Acepromazine Maleate was found to be effective in producing a surgical level of anesthesia within 2 min after administration. The anesthetic state lasted for an average of 1.5 h and could be safely extended by supplemental administrations of the drugs. This anesthetic combination was found to be fast acting, safe, and easily controlled.


A simple method to improve the precision and accuracy of gas-phase oxygen electrodes.

The precision and accuracy of the measurements using an oxygen gas-phase electrode thermostabilized in an ice bath were evaluated. The precision found was comparable with that obtained with the paramagnetic method and with Scholander analysis. The accuracy was comparable with that of the paramagnetic method.


Recording the cardiac interbeat interval distribution.

A compact device is described, which picks up the R wave of the ECG, calculates the duration of successive interbeat intervals, classifies them in eight classes and stores the receptive counts in an integrated-circuit register. The distribution of intervals counted over the experimental period is retrieved through a separate numerical readout device.


Assessment of Scholander micromethod for gas concentrations versus weighing method.

Three gaseous mixtures in N2, of varying concentrations of CO2 (3.60, 5.79, and 9.36%) and O2 (22.18, 15.12, and 6.82%), respectively, were prepared by precise weighings, which may serve as absolute measures. These mixtures were analyzed with two apparatuses by the Scholander micromethod. Taking into account the influence of several factors (apparatuses, order of analyses, etc, it appears that differences between apparatuses were not significant in five of six cases and the effect of order was significant in O2 (P less than 0.01) but not in CO2 for the set of measurements. When compared with weighings, measurements differed only in one apparatus (P less than 0.02) in two of six cases and by no more than 0.02%. The relation between weighings and measurements was highly significant (P less than 10(-9) and no lack of fit to linearity occurs. Side effects of the factors considered and interactions between them are discussed. In conclusion, the micromethod of Scholander gives accurate results, in very good agreement with the reference values provided that certain technical precautions are observed.


A sinusoidal load generator for use in cycle ergometry.

We have modified an electromagnetically braked cycle ergometer to provide a sinusoidally varying work load. This was accomplished by applying a low-frequency sinusoidal voltage at the inputs of the electromagnets using a sinusoidal potentiometer, whose shaft was driven by a variable-speed motor, and a voltage-programmable power supply to amplify the signal. The frequency range is currently 0.0017-0.3 Hz. This technique for sinusoidal work loads allow the period, amplitude, and mean position to be easily changed from a console, even during a test if required.


An exchangable intra-atrial balloon device.

An exchangeable atrial balloon device is described. It consists of an outer guide and a latex Foley urinary retention catheter. The guide is sutured into the atrial appendage and brought out through the chest wall. The advantages of the device are discussed.


Preferential use of casing (girth) measures for estimating body volume and density.

Theoretical justification for the preferential use of casing (circumference) measurements for estimating total body volume (TBV) and body density (Db) was studied in 24 female subjects (mean age 20 yr, mean wt 58 kg). Multiple linear regression equations resulted in R = On-0.99 with a standard error no larger than 1.69 liters for predicting TBV and R = Oa-Oh with a standard error no larger than 0.0084 g/ml for predicting Db. Validations of these regression equations using two additional samples of subjects resulted in validity coefficients of r = 0 -0.99. All the correlation coefficients were statistically significant (P less than 0.01).


Site of central chemosensitivity in fetal sheep.

The heart rate, blood pressure, and respiratory response to topically applied cyanide on the ventrolateral medullary surface and upper spinal cord was studied on exteriorized sinaortic-denervated fetal lambs under pentobarbital anesthesia. On all sites tested cyanide produced a rapid increase in heart rate and blood pressure (P smaller than 0.05) which was most pronounced from the area adjacent to the nerve roots IX to XI (mean 32%). Respiratory efforts consisting of 1-8 gasps were induced in half the applications to the medulla but never when the pledgets were applied to the spinal cord. The mean delay to response was 43 s (range 13-102 s). After cautery of the chemosensitive areas, topical application of cyanide failed to stimulate gasping, whereas intravenous cyanide or cord clamping still produced a vigorous respiratory response. It is concluded that sympathetic stimulation of the heart and blood vessels can originate centrally in response to local histotoxic hypoxia of the ventral medulla and upper spinal cord. Furthermore, it is proposed that in the apneic fetus histotoxic hypoxia of the medulla initiates respiration possibly by stimulating a special gasping mechanism which is separate from the respiratory center responsible for rhythmic breathing after birth. The responsible neurons must be located at least 2 mm beneath the ventral medullary surface.


Reduction of hypoxic pulmonary vasoconstriction during trichloroethylene anesthesia.

A double-lumen tube was inserted into the trachea of dogs anesthetized with intravenous pentobarbital (30-40 mg/kg). Blood flow/unit lung volume in each lung was measured with 133Xe. Both lungs were initially ventilated with oxygen and measurements of pulmonary blood flow, CO2 output, cardiac output, and blood gases were made. When nitrogen was administered to one lung blood flow was diverted to the opposite lung. The diversion of flow was reduced by the inhalation of 1% trichloroethylene but returned after withdrawal of the anesthetic. There were no significant changes in cardiac output. Changes in CO2 output and arterial Po2 were compatible with the xenon results. It is concluded that trichloroethylene may increase arterial hypoxemia by reducing vasoconstriction in hypoxic areas of lung.


Effect of sojourn at 4,300 m altitude on electroencephalogram and visual evoked response.

The purpose of the present study was to determine the effect of sojourn at high altitude on cerebral electrical activity. Electroencephalographic (EEG) and visual evoked responses (VER) were recorded from seven healthy males under the following conditions: 1) during the first 2-3 h at 4,300 m altitude when Pao2 was maintained at 90 mmHg (control condition), 2) during the first 2-3 h of hypoxia (Pao2 = 40 mmHg), and 3) at 24- to 48-h intervals during the first 9-12 days of hypoxia. Electrode placement was according to the 10-20 International Electrode System. The VER was recorded from an electrode at the inion referred to the left ear. We found no significant changes from control cerebral electrical activity during the first 2-3 h of hypoxia. One subject's VER amplitude was greater than control on the 2nd and 3rd days of hypoxia and a similar change from control was consistently evident in a second subject beginning the 5th day of hypoxia. These changes suggest cortical depression. After the 5th day changes occurred in the remaining subjects which would be consistent with cortical excitation. In three subjects, EEG frequency was increased, amplitude decreased, and/or spiking became evident. In four subjects VER amplitude was reduced. Our findings provide support for the hypothesis that certain behavioral and physiological changes induced by sojourn at altitude could be caused by alterations in central nervous system function.


Effect of head skin temperature on tympanic and oral temperature in man.

Five subjects were sequentially heated and cooled in a double-climate chamber while mean skin temperature (except the head) and head skin temperature were separately varied. The tympanic membrane temperatures of these subjects were disproportionately influenced by changes in head skin temperature. By heating and cooling localized regions of the head, changes in tympanic membrane temperature that followed changes in skin temperature on the ipsilateral side of the head could be produced. During heating of the head, oral and tympanic membrane temperatures were influenced to a similar degree, while esophageal temperature remained essentially unaffected. However, under conditions in which the legs and feet were heated in a water bath, esophageal temperature showed more rapid changes than either tympanic membrane or oral temperature. These findings suggest that tympanic membrane temperature and, to a lesser degree, oral temperature may be affected by thermal exchange occurring between arteries and veins in the cervical and cephalic regions. In addition, the ability to influence selectively esophageal and tympanic membrane temperatures brings into question the arbitrary use of these measurements under widely different experimental conditions as estimates of core temperature.


Early effects of tobacco smoke exposure on vascular dynamics in the microcirculation.

The purpose of these studies is to examine the early effects of chronic tobacco smoke exposure on vascular dynamics in the mesenteric microcirculation. Female rats were exposed daily to tobacco smoke from five reference cigarettes for a period of 2 mo. At the end of this period the smoke-treated rats had gained 12 g less than sham-treated controls, and arterial blood pressure in the smoke-treated animals was slightly less than pressure in the sham-treated animals. These are characteristic effects of tobacco smoke exposure on rats. Following the treatment period, red blood cell (RBC) velocity in single mesenteric capillaries and microvascular pressures in arterioles and venules were measured in accordance to established methods. There was no significant difference in pressure distribution on the arterial side of the mesenteric vascular network, but pressure in the venules of the smoke-treated animals was significantly higher than that of the sham-treated group. In association with the higher venular pressure in the smoke-treated animals, capillary RBC velocity (an index of capillary flow) was significantly lower. The reduction in velocity was in proportion to the decrease in pressure drop (arteriole-venule) across the capillary network.


Spontaneous phrenic nerve activity in the exteriorized fetal lamb.

Phrenic nerve activity and tracheal pressure changes were recorded in four exteriorized fetal lambs (120-135 days gestation) from lightly anesthetized ewes to study possible mechanisms involved in the establishment of rhythmical breathing patterns. Two types of spontaneous neural activity were found. The first consisted of high-frequency multiunit bursts (mean duration 820 ms; range 450-2,500 ms) that preceded a gasp. Individual units within these bursts reached peak discharge frequencies as high as 40 impulses/s. The second type of neural activity consisted of single-unit, low-frequency (1-14 impulses/s), irregular background discharges lasting up to several seconds without changes in tracheal pressure. Occasionally, higher frequency bursts of single-unit activity were detected that were also unassociated with tracheal pressure changes. The data indicate that the neural correlate of a fetal gasp includes high-frequency synchronized bursting activity in the phrenic nerve. In addition, background phrenic activity can be detected in the exteriorized fetal lamb that reflects central nervous activity in the absence of tracheal pressure changes.


Mean myoglobin oxygen tension during exercise at maximal oxygen uptake.

Changes in intracellular Po2 in myoglobin containing skeletal muscle during exercise were estimated in normal nonathlete subjects from measurements of shifts of CO between blood and muscle under conditions where the total body CO stores remained constant. Exercise was performed on a bicycle ergometer. In 1.5-2 and 6-7 min runs at Vo2 max with the subject breathing 21% O2, mean MbCO/HbCO increased 146 +/- 7 and 163 +/- 11% of resting values, respectively (P less than 0.05). With the subjects breathing 13-14% O2, in 1.5-2 and 6-7 min runs, Vo2 max fell an average of 4.3 +/- 5.1% and 12.0 +/- 5.2%, respectively, and mean MbCO/HbCO increased to 233 +/- 18% and 210 +/- 52% of resting value, respectively (P less than 0.05). These findings suggest that mean myoglobin Po2 fell during exercise at Vo2 max, with the subjects breathing 21% O2 and the decrease in mean myoglobin Po2 was greater with the subject breathing 13-14% O2. There was considerable variability in different subjects and in some, the data were not consistent with intracellular O2 availability limiting aerobic metabolism. The data support a postulate that there are several limiting factors for the aerobic capacity, including intracellular O2 availability.


A simple fluorescent method for quantitative determination of aortic protein uptake.

A quantitative system for direct protein tracing and measurement of net protein uptake in the aorta using fluorescein isothiocyanate conjugated bovine serum albumin (FITCBSA) is described. Using Wistar rats, a mean aortic FITCBSA net uptake of 29.7 times 10(-17) g FITCBSA per mum2 aortic endothelial surface area per 24 h was obtained. Intra-aortic localization of the FITCBSA was observed along the endothelium and the collagen-elastin bands. The values obtained using this FITCBSA system are comparable with those of a previously established isotopic technique measuring aortic albumin flux and reconfirm the previous findings of the existence of an albumin permeability gradient in the thoracic aorta.


Continuous spectrophotometric measurements of arteriovenous oxygen difference.

A relatively inexpensive dual-beam optical absorbance monitor was tested and adapted to measure arterio-enous oxygen difference ((a - v)delta O2). Since the molar extinction coefficients of oxy- and deoxyhemoglobin are markedly different at 660 nm, the difference in optical density between arterial and venous blood, as measured by the absorbance monitor, was shown to be linearly related to (a - v)delta02. When appropriate cuvettes (optical path length = 0.5 mm) were used, the instrument's 90% response time (4.4 s) was sufficiently rapid for most physiological applications such as Fick determinations of the rate of an organ's oxygen consumption. The theoretical basis of this spectrophotometric (a - v)deltaO2 measurement and sources of error are discussed in detail.


Estimation of cardiac output by analysis of respiratory gas exchange.

Cardiac output is estimated by least squares fitting of a model of pulmonary gas exchange to measurements of respiratory gas composition obtained with a mass spectrometer during a rebreathing maneuver. This new technique estimates cardiac output on spontaneously breathing subjects at rest and requires neither central venous nor arterial blood samples. Principal features of the technique are the use of multiple gases simultaneously in the analysis, the use of a mathematical model for breath-to-breath evaluation of gas exchange, and simultaneous estimation of gas exchange and alveolar gas tensions with the same instrumentation. The technique is compared with thermal dilution estimates in dogs before and during hemorrhagic shock. Two-thirds of these estimates were within 20% of one another. The standard deviation of replication was 15%. Shortcomings, possibilities for improvement, and possible applications are discussed.


A new method for fabrication of latex cuffs.

A new and simple method is presented that is suitable for the fabrication of inflatable cuffs for any gross vascular size. The method lends itself to mass production which is particularly useful for the fabrication of small cuffs. The procedure generally consists of spraying latex on a rotating cylinder in two separable layers. An activating tube is inserted between the layers and the edges sealed. Outward expansion is prevented by means of a suitable backing material.


Force platforms as ergometers.

Walking and running on the level involves external mechanical work, even when speed averaged over a complete stride remains constant. This work must be performed by the muscles to accelerate and/or raise the center of mass of the body during parts of the stride, replacing energy which is lost as the body slows and/or falls during other parts of the stride. External work can be measured with fair approximation by means of a force plate, which records the horizontal and vertical components of the resultant force applied by the body to the ground over a complete stride. The horizontal force and the vertical force minus the body weight are integrated electronically to determine the instantaneous velocity in each plane. These velocities are squared and multiplied by one-half the mass to yield the instantaneous kinetic energy. The change in potential energy is calculated by integrating vertical velocity as a function of time to yield vertical displacement and multiplying this by body weight. The total mechanical energy as a function of time is obtained by adding the instantaneous kinetic and potential energies. The positive external mechanical work is obtained by adding the increments in total mechanical energy over an integral number of strides.


Aldosterone dynamics during graded exercise at sea level and high altitude.

Hormonal responses to graded exercise of eight low altitude residents were examined at sea level (SL) and after 1 (acute) and 11 (chronic) days at 4,300 m (HA). Caloric, water, and electrolyte intakes were controlled, as were temperature and humidity. Blood was sampled at rest and during light and moderate upright bicycle exercise (20 min at 40% and 75% of maximal O2 uptake, respectively). Mean VO2 max at HA was 27% lower than at SL. Resting plasma levels of aldosterone (Aldo), renin, and angiotensin II (A II) were significantly lower (P smaller than 0.05) on day 1 at HA compared to SL, but returned to SL values by day 11. Plasma cortisol values at rest were similar at SL and HA and were not significantly altered by light or moderate exercise. Renin, A II, and Aldo rose progressively with increasing workload in each environment. With acute HA, renin and Aldo were lower than at either SL or chronic HA. The chronic HA levels tended to approximate SL findings, implying adaptation. The data suggest that aldosterone is predominantly under the control of the renin-angiotensin system during graded exercise at sea level and that the response of this system is altered on acute high-altitude exposure.


In vivo dimensional response of airways of different size to transpulmonary pressure.

We studied four supine dogs that were anesthetized with pentobarbital, intubated, and ventilated with a piston pump. The dimensional response of central (CAW) (greater than 2 mm diam) and peripheral airways (PAW) (smaller than 2 mm diam) to changes in transpulmonary pressure (Ptp) was determined by progressive increments in tidal volume (VT). A specially designed electronics relay circuit permitted this relationship to be obtained for points of no flow during tidal volume breathing: i.e., preinspiration (FRC); end inspiration (FRC + VT). The airways were dusted with powdered tantalum. Six airway divisions were identified: four CAW: trachea, main stem, lobar, segmental; and two PAW: subsegmental, and lobular. AP and lateral roentgenograms were obtained by standard technics and primary magnification (mag factor 2). Airway diameters were plotted as a function of transpulmonary pressure between 3 and 26 cmH2O with the diameter at total lung capacity expressed as 100%. The data show that: 1) there is significant distensibility above 5 cmH2O for all airways from the trachea to the lobular airways; 2) that the pressure-diameter plot is a linear plot for each airway from 3 to 26 cmH2O with R values between 0.846 and 0.957; 3) the peripheral lobular airways are more distensible than the central airways (P smaller than 0.05). We attribute the difference in distensibility of the peripheral lobular airways to their lack of cartilaginous support, and their decreased muscular support when compared to the CAW.


Interrelationship of FFA and glycerol turnovers in resting and exercising dogs.

Dogs with indwelling arterial and venous catheters ran on a treadmill on a 10% or on a 15% slope at 100 m/min. Glycerol turnover ([2-3H]-glycerol) and FFA turnover ([1-14C]palmitate) were measured simultaneously. Both turnovers were greatly increased by exercise. Similar increases were produced in resting dogs by norepinephrine infusions (0.5 mug/kg-min). At rest, as well as during exercise, there was a straight-line correlation between the ratio of disappearance of each substrate and their respective plasma concentrations. Over a wide range there was a straight-line correlation between the rate of production of FFA (RaFFA) and that of glycerol (RaGLY) at rest as well as during exercise. At any given RaFFA, RaGLY was higher in the running than in the resting dog. At rest the ratio of RaFFA/RaGLY was found to give the theoretical value of 3.0 only when RaFFA was 10-15 mumol/kg-min, below this the ratio was lower and above this it was higher. During exercise the ratio was lower than at rest and at heavier load lower than at lighter work. The results suggest that in vivo a combination of partial and complete lipolysis as well as reesterification occurs. The glucose equivalent of the glycerol turnover (if 100% converted) represents (under the given experimental conditions) 14-18% of the hepatic glucose output on the 15% slope and 20-25% of it on the 10% slope.


Pulmonary afferent activity recorded from sympathetic nerves.

This study in mongrel dogs, anesthetized with sodium pentobarbital, verified the existence of pulmonary receptors whose afferents traverse the right and left upper thoracic white rami communicantes. These receptors responded to lung inflation as well as pinching of the lung parenchyma and were nonadapting in nature. In some fibers, increases in afferent activity were also observed when the pulmonary artery and veins were mechanically stimulated by probing. Conduction velocities of these afferents were measured in single-fiber preparations and were of the Adelta fiber type.


Mechanism of arterial hypoxemia following pulmonary thromboembolism in dogs.

Mongrel dogs (29) were anesthetized, paralyzed, and ventilated at a constant minute volume. AaD02 breathing air and 100% O2, venous admixture breathing air (Qva/Qt) and 100% O2 (Qs/Qt), single-breath diffusing capacity for CO (DLCO), and total pulmonary resistance (RL) and pulmonary compliance (CL) were measured before and after pulmonary embolization with autologus in vivo venous thrombi. Nine dogs were heparinized before embolization. In the 20 nonheparinized dogs AaDo2 breathing air increased from 11 to 26 mmHg, Qva/Qt from 4 to 22%, and Qs/At from 5 to 8%. DLCO decreased 24%, RL increased 43%, and CL fell 30%. In the nine heparinized dogs AaDo2 breathing air increased from 8 to 13 mmHg and Qva/Qt from 3 to 8%; Qs/Qt did not change. DLCO decreased 31%; RL and CL did not change significantly. The increase in Qva/Qt of 5% in the heparinized dogs was significantly less (P smaller than 0.001) than the increase of 18% in the nonheparinized dogs. These findings suggest that arterial hypoxemia following thromboembolism is due to ventilation-perfusion inequality caused by changes in lung mechanics.