Internal jugular phlebectasia. A clinicoroentgenographic diagnosis. The most common cause of a mass in the neck that appears only on straining is a laryngocele. However, internal jugular phlebectasia may manifest in a similar manner. Dilation of the internal jugular vein with any maneuver that increases intrathoracic pressure suggests mechanical obstruction in the neck or the mediastinum, but the cause is still in doubt. Dilated internal jugular veins have been excised and have been found to have thinning of the wall of the vein, but have not been found to have a congenital abnormality.


Internal jugular phlebectasis. A clinicoroentgenographic diagnosis. The most common cause of a mass in the neck that appears only on straining is a laryngocete. However, internal jugular phlebectasia may manifest in a similar manner. Dilation of the internal jugular vein with any maneuver that increases intrathoracic pressure suggests mechanical obstruction in the neck or the mediastinum, but the cause is still in doubt.  Dilated internal jugular veins have been excised and have been found to have thinning of the wall of the vein, but have not been found to have a congenital abnormality.


The mouth in health and disease.

The mouth in health and disease. Medical, dental and psychiatric conditions may cause dysfunction of the mouth in health and disease. The principle of clinical assessment of the patient, which includes a thorough assessment of the physical, social and psychological factors, is of paramount importance. This paper has attempted to describe some of the more common conditions affecting the mouth in general practice, and to underline important causes of pain which can occur in the face arising from conditions in the mouth.


Community health centre evaluation -- a two year follow up study. The southern memorial hospital. The Community Health Programme has been responsible for the provision of more resources at the primary health care level, and it was forecast that these initiatives would give general practitioners expanded opportunities to develop their skills. An attempt to evaluate this forecast is reported here in a study which surveyed a sample of general practitioners practising in the area now served by the Southern Memorial Hospital Community Care Centre. The results of this study are compared with the results of an earlier study which was completed before the Community Care Centre was established.


Principles of management of maturity onset diabetes. By far the largest group of diabetics coming under treatment are those falling into the category maturity onset. While symptoms of thirst and polyuria, or symptoms or signs of complications may bring cases to attention, many are asymptomatic. The final proof, glycosuria being the presentation, should be sought by glucose tolerance test since it is essential to have confirmation of diagnosis prior to commitment by doctor and patient to life long treatment.


St.Agnes--the first year as the team sees it. The St. Agnes Community Health Centre was established in October 1974, in the rapidly growing area of Tea Tree Gully, South Australia. It was built to provide additional facilities to an already existing comprehensive medical centre. The embryo centre is described during the first year of operation through the eyes of the health team.


The Jukes of Van Diemen's land? or, a Tasmanian problem family. A longitudinal survey into the membership distribution of a Tasmanian family is described. A search of most available sources was made to establish the full name and relationship of everyone with that family name born or landed in the colony since 1803. Over 450 names were collected and a family tree constructed containing, to date, 285 of the names. To begin with, research was based on the idea that this family was unchanged by time and formed a large homogenous group, potentially hopeless and difficult to help. The problem members were identified from social and other records and were found to form only a small proportion of the whole. None of the social agencies, private or State, corrective or remedial, helping or educational, had a true idea of the size of this family group or of the validity of their ideas about the constituent family members. This preliminary study suggests that most of their present ideas are incorrect, and are founded on honest but false impressions.


Instability of DTNB-treated globin or haemoglobin. Human haemoglobin or globin in its native form reacts with 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) with uptake of two 3-carboxylato-4-nitrothiophenol groups, one for each of the reactive thiols at the beta93 positions. Attempts to isolate the DTNB-treated globin by the acetone-HC1 method, which unfolds the protein chains, result in disulphide interchange and oxidation of almost all the uncoupled "masked" thiol groups. This modification is in marked contrast to the stability of haemoglobin or globin treated with reagents such as iodoacetic acid or N-ethylmaleimide that do not form disulphide bonds in blocking the thiol groups. The derivatized globin chains have been separated by urea-thiol buffer chromatography on carboxymethycellulose columns. Amino acid analysis and peptide mapping established the presence and location of disulphide bonds, whilst gel filtration in urea buffers and sodium dodecyl sulphate acrylamide gel electrophoresis defined the size of the products.


Inhibition of wool follicle DNA synthesis by mimosine and related 4(1H)-pyridones. The in vitro incorporation of [3H]thymidine has been examined in thin slices of sheep skin. Most of the radioactivity (88%) was incorporated into the bulb cells of the wool follicles, and the technique is therefore suitable for the study of some aspects of wool follicle DNA synthesis. The effect of mimosine and a number of related 4(1H)-pyridones on [3H]thymidine incorporation into sheep skin slices was examined. Mimosine was shown to inhibit the incorporation at a concentration of 0-2 mM. At this concentration, the incorporation of [3H]uridine or [14C]leucine was not affected. The inhibition of [3H]thymidine incorporation was time dependent, 2 h of incubation being required for maximal inhibition of DNA synthesis, and was readily reversible by removal of mimosine from the incubation medium. The 3-hydroxyl-4-oxo function of the pyridone ring appears to be directly involved in DNA synthesis inhibition. The amino acid side chain is not a toxophoric centre, but changes in its polarity have been shown to affect the inhibitory activity. The results suggest that the primary action of mimosine on the inhibition of wool biosynthesis in vivo is the inhibition of follicle bulb cell DNA synthesis and consequently of cell division.


Methane production and digestibility measurements in the grey kangaroo and sheep. Three grey knagaroos and three sheep were given a diet of lucerne chaff and measurements were made of feed intake, digestibility coefficients, methane production rate and volatile fatty acid content of the "stomach" and caecum for each animal. The kangaroos had lower intakes of digestible dry matter and organic matter than the sheep; this was related to lower intakes of dry matter and lower apparent digestibility coefficients particularly of the crude fibre fraction. Methane production in the sheep (collected in respired air through a mask) was 0-81 litre/h; no methane was collected in the respired air from kangaroos. Anal release of methane in sheep and kangaroos indicated that some methane was produced in the hind gut of kangaroos and that all of this methane was lost via the anus. This finding was different to the sheep which apparently excreted 80-90% of the hind gut methane via the lungs. Thus in both sites of apparent high microbial growth in the gut of kangaroos methane production is negligible or lower than in the same sites in sheep. Possible explanations for the absence of measurable methane production in the kangaroo fore-stomachs are discussed.


Glucose and acetate metabolism in sheep at rest and during exercise. Total entry rate of blood glucose and the rate of irreversible loss of blood acetate and its oxidation have been examined in sheep at rest and while walking on a horizontal treadmill at 5 km/h for 2 h. Sheep were given their daily ration of 1000 g chaff in 24 eaual portions at hourly intervals and received multiple intravenous injections of [2-3H]glucose and intravenous infusions of [1-14C]acetate and NaH14CO3. At rest the total entry rate of blood glucose was 0-44 +/- 0-03 mmol/min (values given as mean +/- s.e.m. for four sheep), the glucose pool was 23 +/- 1 mmol and the rate of irreversible loss of blood acetate was 2-3 +/- 0-1 mmol/min. During exercise, the total entry rate of blood glucose was 0-84 +/- 0-04 mmol/min, the glucose pool was 27 +/- 2 mmol and the rate of irreversible loss of blood acetate was 2-6 +/- 0-1 mmol/min. Gluconeogenesis apparently increased markedly in response to exercise as indicated by the incorporation of 14C from blood bicarbonate into blood glucose. Despite the substantial increase in the rate of irreversible loss of blood bicarbonate (from 11-6 +/- 1 to 20-2 +/- 2 mmol C/min), and hence energy expenditure with exercise, only a slight change was recorded in the proportion of the irreversible loss rate of acetate that was oxidized.


Studies on metatherian sex chromosomes II. The improbability of a stable balanced polymorphism at an X-linked locus with the paternal X inactivation system of kangaroos. Female kangaroos and perhaps other female marsupials have a unique form of dosage compensation for X-linked genes in their soma. In these animals the paternal X is inactive. Heterozygote females therefore have the phenotype of one or the other of the homozygotes, with the allele which is expressed coming from their mother. The unexpressed paternally derived allele may, however, be transmitted to the next generation in the usual Mendelian manner and there be expressed. Such a combination of haploid phenotypic expression and diploid genotypic behaviour on the part of X-linked genes in kangaroos makes their population genetics unique. This paper examines the possibilities for balancing selection in the kangaroo X chromosome system and shows that balanced polymorphisms are unlikely to occur. If 1 - a, 1, 1 - b and 1 are the selection coefficients of the alpha1 females, alpha2 females, alpha1 males and alpha2 males respectively (where alpha1 is the phenotype when A1 is expressed and alpha2 the phenotype when A2 is expressed), then the equilibrium is reached when the gene frequency of A1 in females = 0-5(a-1 + b-1), which takes values between 0 and 1 for only a few of the biologically likely values of a and b.


Linkage and dominance characteristics of genes for resistance to organophosphorus acaricides and allelic inheritance of decreased brain cholinesterase activity in three strains of the cattle tick, Boophilus microplus. Resistance to the organophosphorus acaricides diazinon, dimethoate and formothion in the Biarra (B), Mackay (M) and Ridgelands (R) strains respectively of the cattle tick B. microplus has been shown previously to be controlled in each strain by a single incompletely dominant autosomal genetic factor. A very similar mode of inheritance of fenthion resistance in strain B has now been demonstrated with no departure in degree of dominance of resistance from the mean value of +0-57 common to these strains exposed to these chemicals. No F1 larval progeny from the following crossings were appreciably more resistant than their parents to these chemicals: R x B--bromophos ethyl and fenthion; B x M--carbaryl, chlorfenvinphos, chlorpyrifos, diazinon, dimethoate, ethion, fenthion and formothion; M x R--chlorfenvinphos, diazinon, dimethoate, ethion, formothion. The field importance of this absence of overdominance is discussed. There were no susceptible double recessive F2 larval progeny of B x M crossings of F2 or F3 larval progeny of R x M crossings when tested against dimethoate to which the three parental types were similarly resistant; 1/16 of the larval progeny would be expected to be completely susceptible if the resistance genes were unlinked. F1 adult progeny of B x M and R x M crossings exhibited the incompletely recessive mutant-type decreased brain acetylcholinesterase (AChE) activity common to strains B, M and R, thus satisfying the test for allelism. No ticks with normal levels of brain AChE were detected in F2 adult progeny of B x M or R x M crossings. This evidence was strongly suggestive of a series of closely linked genes or alleles controlling dimethoate resistance and a series of alleles controlling decreased brain AChE activity in strains B, M and R.


Biochemical genetics of resistance to organophosphorus acaricides in three strains of the cattle tick, Boophilus microplus. Three aspects of the biochemical genetics of resistance to organophosphorus compounds in the Biarra (B), Mackay (M) and Ridgelands (R) strains of the cattle tick B. microplus were studied. These were: decreased acetylcholinesterase (AChE) activity in adult brains of strains B and M; decreased AChE sensitivity to inhibitors in adult brains and in larvae of strains B, M and R; and increased detoxication in larvae and adult females of strain M. Comparisons were made with a susceptible reference strain (S). Microspectrophotometric estimations of AChE activity in histochemical preparations of whole brains showed that hybrids had levels of activity approximately intermediate between those of the parental strains. Homogenates of brains from hybrids assayed biochemically gave similar but more precise results which indicated that decreased brain AChE activity was neither recessive nor dominant (degree of dominance, D = +0-02) in strain B and incompletely recessive (D = -0-26) in strain M. The proportions of brains showing decreased AChE activity in testcross and F2 progenies indicated that decreased AChE activity in strains B and M is controlled by single autosomal genes. Inhibition of AChE at diagnostic concentrations of coroxon in brains of B, B x S hybrid and S types suggested that decreased sensitivity of AChE in strain B is incompletely dominant (D = +0-10). Kinetic studies on coroxon inhibition of AChE in brain homogenates of B, B x S hybrid and S types revealed the presence of each parental AChE component in hybrids in equal amounts and the absence of a hybrid enzyme. Dimethoxon inhibition of AChE in brains, their homogenates and larval homogenates of B, M and R types showed that decreased AChE sensitivity was a major mechanism of resistance to dimethoate strongly expressed in B x S and M x S hybrids. The proportion of brains showing decreased AChE sensitivity to coroxon in testocross and F2 progenies indicated that decreased AChE sensitivity in strain B is controlled by a single autosomal gene. The degree of dominance of increased degradative metabolism of coumaphos in strain M was variable; the hydrolytic rate in all M x S hybrids was similar to that of M but the overall detoxication rate in hybrids was lower. Genetic control of detoxication is discussed.


An indirect haemolysis test (IHLT) for bovine brucellosis. A simple indirect haemolysis test (IHLT) was developed to avoid the problem of prozones in the complement fixation test (CFT) for bovine brucellosis. It makes use of a sheep or bovine erythrocytes, treated with a crude lipopolysaccharide fraction of Br. abortus, which are lysed by specific antibody in the presence of excess complement (C'). A number of bovine serum which gave large prozones in the warm CFT, and some in which C'-fixation was completely blocked, were found to react to high titre, without prozones, in the IHLT. Following primary vaccination with Br. abortus strain 19, fewer animals gave positive reactions in the IHLT than in the CFT. Following two doses of 45/20 vaccine, however, positive reactions were more frequent in the IHLT than in the CFT. Preliminary studies of serums from animals known to be infected indicate that the IHLT may be of diagnostic value. The test is easy to carry out, especially when bovine erythrocytes are used, since very few bovine serums require preliminary absorption.


Ovine cysticercosis in the Albany region of Western Australia. 1. Survey of tapeworms of rural dogs. A survey of the cestode infections of 304 dogs from 134 properties in the Albany area of Western Australia was performed. Purgation was induced by oral administration of arecoline and the purge examined for cestodes. The cestodes found and their infection rates were: Dipylidium caninum 16.4%; Taenia spp 36.5%; T. ovis 8.9%; T. hydatigena 15.1%; T. pisiformis 15.1%; T. serialis 2.3%; Echinococcus granulosus 0.7%; Questionnaires completed on 133 of the 134 properties at the time the dogs were purged showed that:--73.6% of farmers were feeding raw sheep-meat and 24.8% were feeding raw offal to their dogs; dogs were treated on a regular basis with a cestocide on 23.3% of properties; dogs were allowed to roam on 21.8% of the properties and stray dogs were considered prevalent on 23.3% of properties. Suggestions for control of Cysticercus ovis are made based on an interpretation of the significance of these findings.


Ovine cysticercosis in the Albany region of Western Australia. 2. Trial control program. The effect of a program to control Teania ovis cysticercosis was investigated on 32 adjacent farms at Mt Manypeaks in Western Australia. Farmers were advised not to feed dogs any raw sheep meat or offal and they were supplied with sufficient cestocide to treat all their dogs every 2 months. Other aspects such as the need for control of the movement of dogs and the correct disposal of offal from home killing of sheep were discussed and recommendations made. The success of the program was determined by recording the incidence of Cysticercus ovis in lambs born on the farms and killed at a local abattoir, and the incidence of T. ovis in dogs on the farms. Before the trial 6.9% of lambs were infected with C. ovis and 11 of the 32 farms had a T. ovis infected dog. The C. ovis incidence figures fell to 2.8%, 0.5%, 1.8% and 0.3% for the four years of the trial, and only 1 dog, a recently introduced puppy, was found to be infected with T. ovis. The results are discussed and reasons for the success of the program as a whole and apparent individual farm failures are discussed.


Observations on the epidemiology of porcine parvovirus. Evidence presented suggests that porcine parvovirus is highly stable and infective. Introduction of virus to susceptible herds results in 100% infection rate within the following 3 months. Active immunity is associated with high persistent levels of haemagglutination-inhibitating (HI) antibody (greater than 256), piglets suckling immune sows acquiring HI titres between 10,000 and 40,000. Loss of passive immunity, measured by HI, occurs in a majority of pigs between 14 and 26 weeks of age (mean 21 weeks), whilst an average of 25% (2-47%) of pigs lose HI titres between 26 and 36 weeks of age. Susceptibility to challenge with virus does not occur until 3-5 weeks following loss of HI titres. In endemically infected herds 98-100% of adult pigs show serological evidence of active immunity. A significant proportion of gilts may not be actively immune to porcine parvovirus at the time of first service, and subsequent infection may occur while these gilts are pregnant.


A survey of the attitudes of Sydney pet owners to veterinary services. One thousand questionnaires were distributed to a random sample of Sydney pet owners in 1974 by a market research organisation. A response rate of 37.5% was obtained. Respondents were most likely to use a veterinary practice because it was conveniently located (27%), recommended by someone (22%),or they had been dissatisfied elsewhere (8%). The majority of pet owners preferred veterinary practices to be multiman (65%), unassociated with other services (61%), and run on an open clinic system (52%) with consultation hours between 6 pm and 8 pm on weekdays (45%), and 9 am and 11 am at weekends (about 50%). 91% had no preference regarding the sex of practitioner who treated their pet. 46% of cat owners and 25% of dog owners said that they would be unwilling to spend over +30 to save their pets life while 34% of cat owners and 55% of dog owners were willing to spend over $100. Professional competence and concern for animals were the qualities pet owners desired most in veterinary surgeons and veterinary practices. After these, pet owners rated prompt attention, 24 hour emergency service and modern professional equipment as the next most important features.


A clinincal evaluation of abdominal paracentesis in the horse. This paper evaluates the usefulness of abdominal paracentesis as a diagnostic aid in abdominal disease in the horse and in particular considers whether or not it can be effectively utilised as an indication for surgical intervention in cases of colic. The results are based upon peritoneal fluid samples collected from 20 normal horses and from 20 cases of colic and peritonitis. Peritoneal fluid was collected from standing horses by inserting a bovine teat cannula into the horses abdomen through the linea alba after desensitisation of the skin on the ventral midline with local anaesthetic. Usually, from 3-5 ml of fluid could be collected from a normal horse. This was either clear or cloudy white or yellow in colour and contained 3310 +/- 703 leucocytes/ml consisting of 63.81% neutrophils, 1.4 +/- 1.3% monocytes, 13.5 +/- 4.3% mesothelial cells and 21.25% +/- 6.2% lymphocytes. Protein content was 1.29 +/- .4g/100ml. Changes in the volume, colour, cellular constituents and protein content of fluid, characterised abdominal disease. In cases of colic, discolouration of the abdominal fluid was found to be the most consistent, reliable and useful indication of bowel necrosis. This in turn indicated the need for urgent surgical intervention rather than conservative treatment. Discolouration commenced early in the course of the disease even while the segment of bowel involved was still viable. Increased volume of fluid, elevated leucocyte count (statistically significant at the 5% level), increased neutrophil percentage and elevated protein levels were less useful criteria for determining the integrity of the bowel. Similar changes from the normal were also found in cases of peritonitis. Here, however, microscopic examination of cells in a smear of the fluid was more useful, as phagocytosis and abnormal cell types indicating infection or inflammation could be seen readily, and a diagnosis based upon these findings. It was concluded that abdominal paracentesis, although no substitute for thorough clinical examination, was a valuable diagnostic aid for abdominal conditions of the horse.


Incidence of Cysticercus ovis in sheep and lambs at Albany, Western Australia. A record was made of the prevalence of Cysticercus ovis in sheep and lambs killed at Albany, Waroona and Geraldton from 1970 until 1973. Detailed dissection of 292 carcases which had passed routine inspection revealed C. ovis in 60 (20.5%). A record of all C. ovis cysts found during routine boning of 102,262 carcases which passed normal inspection showed 10.4 cysts per 100 carcases, and in 6,863 carcases rejected for export because of the presence of C. ovis an average of 24.0 cysts per 100 carcases. An attempt was made to relate the incidence of carcases infected with C. ovis in a line of sheep with the incidence of undetected cysts in carcases from that line which had passed routine inspection. No relationship was established. The relative incidence of C. ovis and C. tenuicollis was recorded in 57,426 sheep to show C. ovis in 2,312 (4.0%) and C. tenuicollis in 15,123 (26.3%). Only 21 (0.1%) sheep in 26,774 were found with hydatid cysts. In 3,823 lambs from 40 farms 486 lambs from 6 farms did not show either C. ovis or C. tenuicollis and lambs from 9 farms did not show tenuicollis and lambs from 25 farms did not show C. ovis. In 604 C. ovis cysts from the hearts and diaphragms of lambs, 36 (6.0%) were considered to be alive.


An analysis of leg abnormalities of boars in the Queensland performance testing station. An analysis was made of the results of leg inspections of boars in the Queensland boar testing station at the start and end of their performance tests. The frequency among boars of 12 specific faults ranged from zero to 90% at the start and 7% to 73% and the end of testing. Of the 362 boars examined, 20% suffered from leg weakness. 11% of these had to be slaughtered and 9% recovered after return to the farm. The only faults significantly associated with leg weakness were: "up on toes" of the front feet and excessive flexion of the front knees ("over at knee"). The sire, breed and herd of origin of a boar had little effect on its having any one of the 12 faults. However, herds were found to differ in the total number of faults per boar and Large White had more front leg faults than Landrace. The correlation between number of leg faults and growth rate of a boar during test was + 0.12. Although lef weakness was an important cause of boar wastage, neither it nor leg faults were significant sources of error in evaluating the performance of boars which completed testing.


Helminth parasites of the fox (Vulpes vulpes) in New South Wales. A total of 930 foxes (Vulpes vulpes) from New South Wales were examined for the presence of gastro-intestinal helminth parasites. The cestodes were represented by Taenia pisiformis with a prevalence of 15.7%, T. serialis (22.6%), T. taeniaeformis (0.1%), Spirometra erinacei (28.7%) and Dipylidium caninum (8.3%). No specimens of T. ovis, T. hydatigena or Echinococcus granulosus were encountered. Toxocara canis was the most prevalent nematode and occurred in 35.2% of foxes. Other nematodes encountered were Uncinaria stenocephala with a prevalence of 30.6%, Ancylostoma caninum (7.5%), Trichuris vulpis (2.7%) and Cyathospirura dasyuridis (0.3%). Oncicola sp was found in 1 fox. The prevalence of various parasites in foxes varied between different regions of New South Wales. All parasites, except S. erinacei and D. caninum were less prevalent in the western regions of the State. T. serialis and T. canis were more prevalent in male than female foxes. Of the parasites found T. serialis had the highest average burden per infected fox (17.9) and T. pisiformis had the lowest (2.8).


Cineradiography of the reticular groove mechanism. The use of cineradiographic studies in the interpretation of how sucked liquid passes to the abomasum in young sucking ruminants is described with special reference to experimental studies in lambs and calves. The work involved an examination of the movements of stainless steel wire or clips inserted via a gastrostomy into the mucosa of the caudal thoracic oesophagus, lips of the reticular groove and margins of the reticulo-omasal orifice. This assisted the interpretation of how these structures are involved in the passage into the abomasum of sucked liquid and into the reticulo-rumen of liquid or solid ingesta or saliva swallowed independently of sucking. An understanding of contributions made by the oesophagus, reticular groove and reticulo-omasal orifice to the passage of sucked liquid into the abomasum was aided by the use of the autonomic blocking agents, atropine and hexamethonium.


Infectivity of Ancylostoma caninum larvae after freezing over liquid nitrogen. Third-stage larvae of Ancyclostoma caninum were exsheathed either by carbon dioxide or sodium hypochlorite treatment. Exsheathment per se reduced the infectivity of third-stage larvae by 45% to 59% without affecting larval motility. Both ensheathed and exsheathed larvae were frozen over liquid nitrogen for 90 days, and thawed. Frozen ensheathed larvae were all killed; but frozen exsheathed larvae were 40-54% as infective as non-frozen exsheathed larvae, and the addition of 10% dimethyl sulphoxide raised the infectivity to 89%, relative to non-frozen exsheathed larvae. Taken together, the deleterious effects of exsheathment and freezing resulted in an infectivity of 16-37%, relative to normal larvae.


Interpretation of bond radiographs: some hazards for the unwary. Four aspects of normal radiographic anatomy are discussed in relation to the diagnosis of bone pathology. Where two bones are superimposed the observer may perceive a phantom radiolucent line parallel and close to one of the bones. The radiolucent line is a Mach band and is an illusion which may simulate a fracture. Nutrient canals may also simulate fractures. Although subject to typical site, number and direction, exceptions are frequent. They are commonly seen in the bones which participate in the elbow and knee joints of the dog and cat, and are most likely to be misinterpreted in the tibia and humerus. The thickness of cortical bone is not easily predicted from first principles and is of similar dimensions in both toy dogs and giant breeds. It may prompt a diagnosis of osteoporosis in the latter. The normal appearance of cancellous bone varies from species to species. In the cat and wheep the spongiosa is coarse and sparing and may falsely tempt a diagnosis of osteoporosis. The trabeculae are delicate in the pig and abundant in the horse. To aid correct interpretation it is recommended that a comprehensive library of normal films should be collected and used for empirical comparison where doubt exists.


A survey of blood lead levels in dogs and cats. The blood of 206 dogs and 26 cats was analyzed for lead by non-flame atomic absorption giving mean levels of 6.4 mug/100 ml for dogs and 5.2 mug/100 ml for cats. Statistical treatment of the results using a paired Students' t-test showed significant differences by age for dogs but not for cats. Urban dogs had significantly higher blood lead levels than country dogs (P less than 0.05) thus indicating that dogs can be regarded as useful environmental monitors for lead pollution.


Internal parasites of feral cats from the Tasmanian Midlands and King Island. Eighty-six feral cats from a sheep grazing area in the Tasmanian Midlands and 21 from King Island were examined for internal parasites. Major food items in order of decreasing prevalence in stomach contents were insects, lizards, birds, rodents and frogs in the Midlands, and rodents, birds, insects, and lizards on King Island. Feral cats from the Midlands had 4 cestode, 7 nematode, 2 trematode and 3 protozoan parasites as follows: Spirometra erinacei (66.3%), Taenia taeniaeformis (2.3%), Dipylidium caninum (1.2%), Toxocara cati (86.0%), spiruroid nodules containing Cylicospirura felineus and Cyathospirura dasyuridis (57.0%), Ollulanus tricuspis (11.4%), Uncinaria stenocephala (2.3%), Aelurostrongylus abstrusus (39.2%), Capillaris aerophila (30.0%), Echinoparyphium sp (27.1%), Fibricola minor (6.8%), Isospora felis (12.7%), I. rivolta (5.4%), and Sarcocystis sp (1.8%). Antibodies to Toxoplasma gondii were found in 51 of 53 serums. Three cestode and 5 nematode parasites were found in cats from King Island: T. taeniaeformis (49.2%), D. caninum (23.8%), S. erinacei (19.0%), T. cati (90.5%), C. felineus (42.9%), C dasyuridis (9.5%), O. tricuspis (4.8%) and C. aerophila (9.5%). This is the first record of Cylicospirura felineus, Fibricola minor and Echinoparyphium sp in cats in Australia.


Factors affecting the detection of infestations of Boophilus microplus in tick control programs. Factors affecting the probability of detecting infestations of Boophilus microplus when herds of cattle are examined were studied. The probability of detecting a tick depends on the number of infested cattle in the herd, the probability of ticks being present on the areas of the beast examined, the efficiency of the examination and the proportion of the herd examined. A mathematical expression relating these factors was derived, and a range of values calculated to demonstrate the relative importance of each factor. It was evident that the efficiency of the examination should be kept better than 75%, and that it is necessary to employ a high sampling rate, preferably 100% of the herd. The probabilities of ticks being present on 6 predilection sites and 4 combinations of sites of an infested animal were determined experimentally. The tail butt, esutcheon, belly, dewlap and to a lesser degree neck and ear were all very suitable sites on which to find cattle ticks. A combination of tail butt, escutcheon and neck produced probabilities (0.58 and above) considered adequate to form the basis of an examination system. Examination systems used in New South Wales, Queensland, Argentina and at the United States-Mexico border are described. As a result of this study a new standardised system has been adopted by the Board of Tick Control for use by all New South Wales inspectors.


Blowfly strike in the breech region of sheep in relation to helminth infection. The incidence of breech strike in radically mulesed weaner sheep was reduced from about 50% to about 5% by suppression of helminth infection. Prediposition of sheep to flystrike appeared to result from the helminths causing diarrhoea and soiling of the wool in the breech region. Wethers were struck more frequently than ewes. The efficiency of control of breech strike in mulesed weaners is considered in relation to helminth control and crutching.


Effect of nutrition in the rearing and laying phases on mortality and egg composition of crossbred layers. Crossbred pullets reared on a low plane of nutrition had a lower mortality rate due to Marek's disease and lymphoid leucosis in the laying phase and had smaller livers with less fat than those reared on a high plane of nutrition. On the other hand, the addition of 0.06% methionine to the laying diet increased the incidence of deaths due to Marek's disease and lymphoid leucosis. The spleen weight of birds fed the diet supplemented with methionine was greater than that of those fed the unsupplemented diet. The source of cereals in the laying diet had no effect on mortality, but birds fed diets with barley had larger livers and spleens. The gizzards and intestinal tracts of the birds fed the diet with oats were larger than that of birds fed diets based on barley. The inclusion of 2.5% rapeseed oil in the laying diet resulted in haemorrhage of ovarian follicles and reduced the proportion of yolk in the egg.


Specific gravity and osmolality as measures of urine concentration in the calf. Specific gravity and osmolality were determined for daily urine output from 8 male calves that developed diarrhoea. Both factors increased significantly during diarrhoea. From the correlation (r = 0.724) between them and the range of predicted osmolality values for any particular SG the use of osmolality was confirmed as a precise measure of urine concentration in the calf.


Treatment of pregnancy toxaemia in ewes by induction of parturition. Treatment of pregnancy toxaemia in ewes by induction of parturition is reported. The efficacy of 3 formulations of dexamethasone, at different dosages, is recorded and discussed.


Persistent pupillary membrane in the Basenji. One hundred and five Basenjis of varying ages were examined for the presence of persistent pupillary membrane. Lesions were detected in 75 individuals and were judged to be of minor significance in 26 cases, and of major significance in 49 cases. A system of scoring individuals for breeding merit was devised. The condition would appear to be a major problem in the breed in Victoria and some control measures are warranted.


The use of synthetic prostaglandin analogue to induce oestrus in mares. A clinical trial involving 359 mares was conducted to ascertain the clinical value of a synthetic prostaglandin analogue (fluprostenol, ICI-81,008) structurally related to PGF2oc for treating mares in prolonged dioestrus. Some 263 mares (73.3%) displayed oestrus within 5 days of a first intramuscular injection of 250 mug fluprostenol and, of those mares later examined for pregnancy, 108 (40%) were found to have conceived during the first induced oestrus. A further 21 mares (8%) cycled normally and conceived to services during the second oestrus. Most (80.3%) of the plasma samples obtained from 242 mares prior to treatment showed a progesterone concentration greater than 1 ng/ml, thereby indicating the presence of functional luteal tissue in the ovaries. The results support earlier observations that most non-pregnant mares which fail to cycle during the breeding season are in a state of prolonged dioestrus rather than anoesturs.


Immunisation against bovine vibriosis due to Campylobacter fetus subsp. fetus biotype intermedius. A vaccine prepared from Campylobacter fetus subsp. fetus biotype venerealis gave only partial protection to heifers and bulls against genital infection with C. fetus subsp. fetus biotype intermedius. Heifers and bulls were fully immunised against C. fetus subsp. venerealis biotype intermedius by administration of a vaccine prepared from homologous organisms.


"Woolly everlasting daisy" (Helichrysum blandoskianum) toxicity in cattle and sheep. Investigations into cattle mortalities suspected of being caused by the Woolly Everlasting Daisy (Helichrysum blandowskianum) revealed lesions of marked periacinar liver necrosis, vascular degeneration, widespread haemorrhages and oedema. Brains showed status spongiosus. These lesions were reproduced in cattle and sheep fed Helichrysum and in cattle given an intravenous injection of an extract of the plant.


The identification of Taenia species from Australian carnivores. An investigation into the reliability of various morphological criteria in differentiating species of Taenia in Australia showed that both the anatomy of the mature proglottis and the gross morphology of the worms were reliable methods if suitably relaxed anf fixed specimens were available. Measurements of rostellar hoods were useful but did not provide unequivocal identification due to overlap in sizes; urine branch numbers were found to be of little use.


Reduction of anticoccidial drug resistance by massive introduction of drug-sensitive coccidia. Massive introduction of a drug-sensitive attenuated strain of Eimeria tenella in a floor-pen heavily contaminated with a drug-resistant strain produced a marked reduction in the proportion of drug-resistant oocytsts in the litter. This provides a useful adjunct to planned immunization programs since the procedure protects the birds against subsequent challenge through immunity imparted by the introduced strain while restoring the effectiveness of the anticoccidial drug which was previously ineffective because of the predominance of drug-resistant coccidia.


Evidence of genetic heterogeneity of some lentogenic Newcastle disease virus strains. Two distinguishable subpopulations were recovered from chickens infected with lentogenic strains of Newcastle disease virus originally ioslated from chickens in Australia and Ireland. In both instances, a subpopulation that rapidly eluted from chicken erythrocytes was recovered predominantly from tracheal swabs, and a slow-eluting subpopulation from cloacal swabs. The two subpopulations differed in thermostability of the hemagglutinatin and mean survival time of infected chicken embryos, as well as in elution pattern. The heterogeneity characteristic of the Aust-V4 strain and NI-Ulster strain could not be demonstrated in B1, NJ-LaSota, and ENG-F, lentogenic strains commonly used in vaccines. The question is discussed of whether standard vaccine strains are also hetrogeneous if a technique for separating stock populations is found, and the significance of possible heterogeneity to the effectivenss of the vaccines.


Readability of approach charts as a function of visual acuity, luminance, and printing format. This study determined the ability of 12 presbyopic subjects to read numerals from aeronautical approach procedure charts. The readability of chart numerals was determined for 15 size and contrast combinations as a function of near visual acuity (equivalent 20/20, 20/40, and 20/60) and chart brightness (100 and 1.0 ft L). Test subjects were evaluated at the normal near-visual-acuity level (20/20) and the minal near-visual-acuity levels (20/40) for Classes I and II and 20/60 for Class III) as specified in the FAA's Guide for Aviation Medical Examiners. The results indicated that subjects with 20/20 near visual acuity could read all chart numerals under bright and dim luminance conditions. Subjects with 20/40 and 20/60 levels of near visual acuity experienced reading difficulty under bright conditions and increased difficulty under dim luminance.


Familial differences in antibody response of broiler chickens to vaccination with attenuated and inactivated Newcastle disease virus vaccine. Genetic differences in immune response to Newcastle disease virus (NDV) were studied in 4-week-old broilers, vaccinated with attenuated (live) or inactivated NDV. The experiment included 370 chicks from two farms distributed among 22 sire families and 60 dam families. Results in chicks from both farms were similar. Survival after challenge was closely related to titer level. The genetic correlation between day-7 and day-12 titers (attenuated virus) was 1.0. Significant differences were found between sire families in both sorts of vaccinations. Heritabilities based on the sire variance components for attenuated and inactivated virus vaccinations were respectively 0.31 and 0.60. The genetic correlation between them was 0.49. Nevertheless, it is concluded that selection for response to NDV based on inactivated virus may be most effective in improving response to attenuated NDV vaccinations.


Pulmonary gas exchange in acute mountain sickness. The severity of acute mountain sickness (AMS) was investigated in healthy volunteers, airlifted to high altitude (5,360 m). Blood gases were measured at 2,990 m and 5,360 m. Symptoms of AMS were found in all subjects, but ranged from malaise to vomiting with intractable headache. The clinical severity of AMS was directly related to the arterial PCO2 and inversely to pH, but unrelated to the PO2 on arrival at high altitude. However, PO2 fell and was lowest 48 h after arrival at high altitude in those subjects with the most severe AMS. These were the only subjects to show an increase in the alveolar-arterial PO2 difference and in the venous admixture ratio during the first 48 h. These abnormalities in gas exchange, which developed in the subjects with the most marked cerebral symptoms, suggest that the manifestations of cerebral and pulmonary dysfunction at altitude develop simultaneously, a finding that suggests coexisting cerebral and pulmonary edema.


Measurement of change in plasma volume during heat exposure and exercise. The application of radio-iodinated human serum albumin (RISA) to the measurement of a continuously changing plasma volume, such as that occurring during heat exposure and exercise, has been considered in terms of the exchange dynamics of albumin between the intravascular and extravascular compartments. In six male subjects resting supine for 2 h in a hot environment, or exercising for 50 min in a thermoneutral or hot environment, there was no statistically significant alteration in the rate of protein efflux from the intravascular space. However, following exercise, protein was added to the circulation at a greater rate than it was lost through the capillary walls. A technique for calculating plasma volume from a single measurement of plasma RISA activity is described. This may be used in conjunction with measurements of changes in haemoglobin concentration of determining plasma volume in situations where alterations in protein exchange dynamics do occur.


Effect of gentamicin on early mortality and later performance of broiler and Leghorn chickens. Field and floor-pen trials demonstrated that subcutaneous injection of 0.2 mg gentamicin at one day old reduced bacteria-caused deaths in White Leghorn and broiler-type chicks. Growth, feed efficiency, and condemnation data from broiler trials suggested an advantage for treated chickens over unmedicated controls. Ninety-nine percent of clinical isolates were susceptible to gentamicin (10 mug) when tested by the modified Kirby-Bauer method. In vitro susceptibilities of these isolates to neomycin, nitrofurazone, chloramphenicol, and kanamycin varied from 90 to 94%. About half of the isolates were susceptible to dihydrostreptomycin or tetracycline in vitro, while less than 10% were susceptible to penicillin or clindamycin. In vitro tests to determine the lowest concentration of antibiotics required to inhibit the growth of 31 bacterial isolates demonstrated that less gentamicin is required than neomycin, spectinomycin, or oxytetracycline.


Comparison of six methods of detecting Salmonella typhimurium infection of chickens. Six methods were used in testing for prior exposure of chickens to Salmonella typhimurium (ST). The most sensitive and reliable was the microantiglobulin (MAG) TEST; LESS RELIABLE WERE THE TUBE AGGLUTINATION, MICROAGGLUtination, rapid-whole-blood, and rapid-serum-plate tests. It was assumed that the agglutinins demonstrated by the MAG test method were the direct result of exposure to ST, and that the MAG test detected the maximum number of birds previously exposed to ST. The cloacal swab culture method was inadequate.


Medical experiment M-171: results from the second manned Skylab mission. Preflight, inflight, and postflight exercise response tests were conducted on the astronauts of the second Skylab mission (Skylab 3) as part of an evaluation of physiological adaptation to long-term weightlessness. The flight phase of this mission was 59 d in duration. An exercise protocol was designed around a bicycle ergometer which was used to apply work loads approximating 25, 50, and 75% of each crewman's measured maximum aerobic capacity (VO2 max). Respiratory gas exchange (VO2, VCO2, and VE), heart rate, and blood pressure were measured during all tests; cardiac output was measured at selected times during preflight and postflight tests. Data obtained both at rest and during exercise in flight showed no consistent changes which would indicate a degraded physical work capacity. In fact, heart rate during exercise actually decreased for all crewmen in flight. This response indicated improved physical fitness in flight relative to preflight. The improved physical condition of this crew relative to that of the first Skylab crew is attributed to frequent performance of high levels of aerobic exercise in flight. The postflight period of readaptation of 1 G was characterized by a marked tachycardia, during which time stroke volume was decreased. This response returned to normal within 5 d postflight.


Development of cold agglutinin to chicken red blood cells in Mycoplasma synoviae infection. Serum from birds chronically infected with Mycoplasma synoviae (MS) evidenced a cold agglutinin (CA) which agglutinated chicken, cat, dog, and guinea pig red blood cells (RBC) but did not agglutinate bovine and sheep RBC. Agglutinin to dog RBC was widespread in serums of birds, whether or not infected with MS.


Free amino acids in human blood plasma during space flights. The present investigation presents results of studying free amino acids of peripheral plasma in cosmonauts who made space flights of different duration onboard the spacecraft Soyuz-12, Soyuz-16 and the orbital station Salyut-4. The study showed changes in the content of free amino acids which varied for different amino acids. Most pronounced changes were found in the content of glutamic and aspartic acids, sulfur-containing amino acids and arginine.


Teratoma in a chicken (Gallus domesticus). A large mass composed of multiple tissue elements was observed in the abdominal cavity of a chicken. The tumor mass was tridermic microscopically, and therefore classified as a teratoma.


Effects of head-down tilt on fluid and electrolyte balance. The metabolic effects of -5degrees tilt were studied in eight normal individuals. Exposure to tilt for 24 h increased solution excretion and decreased plasma volume. Plasma renin activity and plasma aldosterone levels were not significantly different from supine values during the first 6 h of tilting, but were increased significantly at the end of the 24-h tilt period. Creatinine clearance and potassium balance were not affected by the tilt. These findings indicate that head-down tilt induces a sodium diuresis and stimulation of the renin-angiotensin-aldosterone system.


Increased 2,3-diphosphoglycerate during normocapnic hypobaric hypoxia. The effect of 96 h of exposure to hypobaric hypoxia with and without 3.8% CO2 supplementation was studied in two groups of subjects. Five subjects (CO2) were exposed to 440-465 mm Hg barometric pressure (4000-4400 m), and 4 subjects (no-CO2) were exposed to 455-492 mm Hg (3500-1400 m) in order to produce similar levels of resting end-tidal PO2. After 24 h, 2,3-DPG levels of both groups significantly increased and remained elevated. The CO2 group had higher levels than the non-CO2 group after 48 and 72 h. Concurrent measurements of P50 showed similar changes over the same time course. Mean corpuscular hemoglobin concentrations remained normal for 48 h and then decreased in both groups, the CO2 group showing the larger decrease. We conclude that altitude exposure may produce an increase in 2,3-DPG without the presence of respiratory alkalosis previously thought necessary.


Injectable agent for the treatment of air emboli-induced paraplegia in rats. Rats with air emboli-induced paraplegia were treated with dialy levodopa injections (intra-arterially or intraperitoneally). Of the control animals, 20% fully recovered from paraplegia during a period of 7 d. Of the levodopa treated animals, 85% fully recovered during the same period. It appears, therefore, that levodopa might be one of the few injectable agents enhancing recovery from air-induced paraplegia, suggesting its possible use in decompression sickness.


Responses of the autonomic nervous system during acclimatization tp high altitude in man. A study has been conducted on 20 sojourners, between the ages of 20-30 years, to evaluate responses of the autonomic nervous system during acclimatization to high altitude. The responses measured consisted of heart rate (HR), blood pressure (BP), oral temperature (Tor), mean skin temperature (Tsk), cold pressor response (CPR), orthostatic tolerance to tilt, and urinary catecholamines. The subjects were tested initially at Delhi (altitude 260 m) and thereafter, on acute induction to an altitude of 3500 m periodically for 3 weeks. For comparison, the same responses were studied on 10 acclimatized lowlanders (AL) who had been staying at the same altitude for more than a year and on 10 high-altitude natives (HAN). The studies showed a rise in HR, BP, Tor, and urinary catecholamines, and a fall in Tsk, CPR, and orthostatic tolerance immediately on arrival at HA, indicating a relative hyperactivity of the sympathetic system. After a stay of 1 week, there was a gradual recovery in all the responses, though sympathetic hyperactivity was still maintained throughout the 3 weeks of stay. In AL also there was a preponderance of sympathetic activity, though of relatively lesser magnitude than that seen in sojourners. In HAN, on the other hand, there was a relative parasympathetic predomination. It has been concluded that in lowlanders it takes more than a year of stay at altitude for complete recovery of autonomic balance.


Effect of penetrating radiation on skeletal muscles of rats in weightlessness. The isoenzyme composition of lactate dehydrogenase of soleus and plantaris muscles of rats flown for 20.5 d aboard the biosatellite Cosmos-690 and irradiated with a dose of 800 rad was investigated. The muscles exposed to weightlessness per se and weightlessness combined with radiation showed similar changes in their carbohydrate metabolism. On return to 1 G, readaptation of irradiated rats developed less rapidly than of animals exposed to weightlessness alone.


Antiorthostatic hypokinesia as a method of weightlessness simulation. Physiological effects seen in eight test subjects during a 5-d bedrest experiment in the head-down position (0,-4,-8,-12degrees) were studied. It was shown that the antiorthostatic hypokinesia at -12degrees could reproduce physiological responses shown by space crewmembers more closely than recumbent bedrest. Our observations help to stimulate an acute stage of human adaptation to the weightless state and to assess the part played by gravity-induced blood redistribution in the development of physiological changes.


Psychologic and psychophysiologic response to 105 days of social isolation. The responses of nine subjects to 105 d of social isolation are reported. The study reveals that crew selection plus ongoing support by psychiatric staff permits continued function in an exotic milieu. Prediction of psychophysiologic symptoms was possible using paper and pencil tests. Trait anxiety was altered by the isolation in a psychologically healthy direction. Sudden time shifts of 8 h led to an immediate significant increase in depression, aggression, and hostility, and are accompanied by marked increases in physical symptoms. During the first free-running phase of the experiment, significant shifts were found on four psychological measures. The shifts indicate that subjects became less trusting, more orderly, more routinized, less energetic, and more depressed. A reducer-augmenter scale predicted the number of psychophysiologic complaints reported by individual subjects while isolated. A group interaction effect on circadian rhythms was isolated but needs further examination.


Idealized inflight airline medical kit: a committe report. A list of individual items for the contents of an inflight medical kit for airline use has been prepared by the Air Transport Medicine Committee of the Aerospace Medical Association. Each item is described along with its primary purpose. A short discussion of the operational factors relating to an inflight medical kit is contained in the paper.


Effects of rapid round trips against time displacement on adrenal cortical-medullary circadian rhythms. The effects of rapid round trips against time displacement on circadian rhythms was investigated. The study was carried out on three occasions using one volunteer healthy physician on east-west trips (Tokyo-San Francisco-Tokyo) of short and prolonged stays. The control study was performed on a north-south trip (Tokyo-Sydney-Tokyo) which had practically no time displacement. The circadian rhythms of urinary 17-OHCS, 17-KS, and noradrenaline excretions and plasma cortisol in short-stay trips were disrupted and not synchronized; however, the recovery was rapid with the circadian rhythms returning to normal within 1 to 2 d. On the other hand, the circadian rhythms of these variables in the control study were not disrupted. These results suggest that a short, overnight stay during the trip minimizes the ill effects due to time displacement.


Food sanitation and air safety.

Food sanitation and air safety. This paper summarizes six ways that poor food hygiene or unsanitary food disposal practices can influence safety. It was prepared in response to a request by the Air Transport Medicine Committee of the Aerospace Medical Association. Fifteen key safety steps than can be taken are given for the use of aviation medicine workers and aircraft operators, especially the airlines.


Transportation in commerical aircraft of passengers having contagious diseases. Most airlines refuse to board passengers known or believed to have contagious diseases. Such rigor can scarcely be justified by reference to either laws or regulations. It introduces the risk of arbitrary, mistaken, or prejudiced conduct in areas in which international organizations recommend the greatest liberalization, and it can cause serious harm to certain patients. Finally, it does not seem logical, for airlines learn about only a small fraction of the contagious persons who travel, and public health is much more greatly endangered by unknown contagious persons. Normal hygienic conditions aboard planes suppress the risks of contagion concerning most diseases transmitted by insects or through contact with the skin, with mucuous membranes, with the faeces, or with urine. Airlines should continue to refuse to transport only those passengers having diseases which are characterized by vomiting or serious diarrhoea or which are transmitted through the air if it is impossible by simple means to avoid the risk of contaminating other travellers and any members of the flight crew who might be receptive.


Exercise in an hypoxic environment as a screening test for ischaemic heart disease. Submaximal and maximal exercise testing have been used to predict coronary events but these tests do not give reliable information regarding employability of subjects with abnormal electrocardiogram. In 30 subjects with stabilized ischaemic heart disease (Group A) and 70 subjects with abnormal resting electrocardiogram (Group B), resting electrocardiograms--at ground level and at a simulated height of 4592 m (15000 ft)--after 40-min exposures were recorded. The double Master's two-step exercise test (DM) was performed at ground level as well as at stimulated height (DMH). In the ischaemic group, exercise combined with hypoxia did not yield better results than exercise alone; but among the asymptomatic subjects, exercise in an hypoxic environment gave significantly better results than exercise alone (p less than 0.005) or hypoxia alone (p less than 0.01). Those with negative responses to the test have been employed on strenous duties, including employment at high altitude for the last 3 years. None of them have manifested any objective or subjective evidence of ischaemic heart disease. DM exercise testing in an hypoxic environment is a reliable method to assess subjects with abnormal electrocardiogram and evaluate their functional status.


Selective breeding for acoustic priming. Data on eight generations of selective breeding for acoustic priming efficacy are reported. The realized heritability of this trait is approximately 0.2-0.3, indicating that the trait is determined in part by genetic factors. Animals selectively bred for acoustic priming do not differ in terms of first-trial (i.e., non-priming-induced) audiogenic seizures. These data suggest that acoustic priming and first-trial audiogenic seizures are controlled by different genetic mechanisms.


[DNA in growing hearts of children. Biochemical and cytophotometric investigations (author's transl)]. In order to clarify the question of an age-dependent polyploidisation of the myocardium during normal cardiac growth, the DNA-content of 39 hearts of infants and children was investigated. After autopsy the total cardiac weights were estimated and thereafter, following the preparation of the hearts, the pure weight of the myocardium (preparation weight) was determined. Using the diphenylamine reaction according to Dische and Burton, the DNA-concentrations and total amounts of DNA in the heart muscle were estimated. The DNA-content of the heart muscle cell nuclei (ploidy classes) was measured cytophotometrically on Feulgen-stained smears of heart muscle cells. DNA measurements were performed on tissue samples from 6-8 different sites of both heart chambers. Growing human hearts of all ages were investigated including 3 fetal hearts and 3 hearts with malformations.


Eosinophilic infiltration of the gastro-intestinal tract (eosinophilic gastroenteritis). Two further cases of eosinophilic infiltration of the gastro-intestinal tract (eosinophilic gastroenteritis) are presented, involving the small intestine of a 73-year old male and the stomach of a 39-year old male. Peripheral blood eosinophilia was present in one case. Clinico-pathological correlations are discussed.


Lethal complications of typhoid-cholera-vaccination. (Case report and review of the literature). Simultaneous parenteral vaccination against typhoid and cholera lead to death through either anaphylactic shock or endotoxic shock in a 36-year-old male. At autopsy the charactertic features of shock as well as chronic interstitial myocarditis were noted. Moreover, fresh histiocytic and lymphocytic nodules were found in the liver, heart and meninges. A review of the literature dealing with lethal complications following parenteral tyhoid vaccinations shows an increased risk in debilitated persons (emaciation, stress, cold). Most of the fatalities occurred in persons who had previous disturbances of the cardiovascular system, as in the case reviewed here. Cardiac failure, Landry's paralysis, renal failure and disturbances of skin, joints and intestines may also follow typhoid vaccinations. However, these latter complications are usually not lethal. The patients presented here had many of the conditions which are known to aggravate the situation and to lead to a lethal culmination. The review of this case and the disucussion following it shows that only healthy persons should receive the parenteral typhoid vaccination. Hopefully, the presentation of this material will help prevent fatalities of this type in the future.


Implications of the monoclonal character of human atherosclerotic plaques. The evidence for the monoclonal nature of human atherosclerotic plaques is briefly reviewed. The interpretation of the cellular monotypy found in a large percentage (75 to 80%) of discrete raised atherosclerotic plaques as being monoclonal in origin appear firm since the size of patches of cells of the same type appears to be very small (ca. 10(-4) cu mm and 10 +/- cells). Evidence for explanations other than single cell origins of each plaque do not appear, at the moment, to be compelling. If we assume then that there is reason to accept the monoclonal character of atherosclerotic plaques in human beings then we are led to a search for the presence of factors that could "initiate" the monoclonal proliferation as well as factors that may promote the growth of the plaques. Evidence is presented that increased risk of atherosclerosis found with cigarette smoking is due to absorption from the lung and circulation in the blood of aryl hydrocarbons. Experiments show that these are preferentially carried in the same parts of the serum that transport cholesterol. The possibility of intrinsic initiators derived from cholesterol is discussed. A possible mechanism for the role of hypertension in promoting atherosclerosis is considered. Finally the evidence for a possible role of viruses in the pathogenesis of atherosclerosis is discussed.


[Development of specialized cooperative animal production units of the agro-industrial type in the USSR]. The development of Soviet agriculture, especially the animal production, is outlined. It proceeded from the formation of socialist large farms with a versatile production profile--mostly comprising all kinds of animals--towards establishing specialized departments (farms) in these cooperatives and, in recent years, towards the development of large production units with a specialized production profile on an industrialized basis (animal farming complexes). Specific probelms of the transition towards specialized production of and with cattle in large units are discussed. The formation of cattle-fatening enterprises is outlined on the basis of experiences gained in the Southern part of the European part of the RSFSR in the Krasnodar region since that middle of the 1960s. The effectiveness of beef production in this new type of enterprise lies well beyond the results reached in the traditional collective and state farms, although it has not yet reached the target set of the state animal production complexes. The cooperative cattle fattening farms can be considered part of future agro-industrial complexes and can actually become part of these.


[Significance of animal feed within the animal hygiene in the warm countries]. Based on the role of nutrition within the relations between the animals and their surroundings the importance is outlined of animal nutrition as part of animal health in tropical and subtropical countries. The author describes damages caused by feeding, foodstuff and wrong nutrition in extensive and intensive production of various types of animal farming (located and nomad) and breeds (indigenous and specialized). If natural pastures are used, extensive animal farming is especially prone to seasonal wrong nutrition. This is exemplified from the sheep production (utilization of the desert steppe under the conditions of the subtropical winter rain climate) and from the cattle production (utilization of the savannah under the conditions of the alternate humid tropical zone). The nutrition damages encountered under intensive locs in moderate zones. The author includes examples of damages caused by foodstuff. Finally the relations are discussed between nutrition and resistance to infections.


The effect of light and temperature on the growth of two subtropical and two temperate grass species. The effect of light intensity and temperature on the growth of young plants of two temperate (Lolium perenne, Festuca arundinacea) and two subtropical (Lolium rigidum, Bromus unioloides) grass species was studied in the northern part of the GDR under open-air conditions. It was found that the subtropical species reacted highly sensitive to changes in the two environmental factors and showed absolutely higher growth performance during the summer as compared with the temperate species. The multiple regression analysis showed positive correlations between the relative growth rate (RGR) and the net assimilation rate (NAR) on the one hand and temperature and light intensity on the other hand. For most regression functions the range of variation was found to be between 63.5 and 91.3 per cent. No clear proof could be found of the dependence of the leaf area ratio (LAR) on light and temperature. The results are discussed and compared with similar investigations.


[Possible use of growth regulators for plant processes in selected grain pod-vegetables]. The cultivation of beans and peas as grain legumes in large-scale production requires plants with a high yield and suitable for machine harvesting. Growth regulators for plant processes can also be applied to achieve these properties. The effect on the yield by growth regulators, as demonstrated in pot and field trials, seems to enable their application in an established intensive cultivation of beans and peas. Prior to this, however, it has to be demonstrated that these positive effects of growth regulator application can reproduced economically in different locations and with different species.


[Studies on the physiological behavior of Pinus merkusii Jungh. and Pinus massoniana Lamb]. The formation and the function of the resin channels result from processes in the history of development; differences between various pine varieties must be traced to differentiation processes in the history of development. Longer flowing duration, higher reformation speed and reduced crystallization are properties which make Pinus merkusii especially suited for systematic resin production. Pinus merkusii does not react to treatment with weak acids or biologically effective stimulants, like yeast extract solution, which can be used to increase the yield of Pinus massoniana up to 30%. This means specific stimulants for Pinus merkusii still have to be found.


Comparative investigations into the content of available molybdenum in important soils of the arid and humid tropics. The determination of the content of available molybdenum in 196 soil samples from different geographical (Yemen, Sudan, Tanzania, Ghana, Cuba, and Sri Lanka) and climatic (annual precipitation 30-3000 mm) regions gave these results: 1. Arid and subarid soils of dry regions as well as rendzina-type soils contained the highest amount of available molybdenum (0.216 ppm respectively). The lowest content was determined in the ferrallitic soils of the humid tropics (0.045 ppm). These differences are mainly attributed to high pH values and CaCO3 content in aridisols and rendzina-type soils and to a strongly acid soil reaction in ferrallitic soils. 2. The content of available molybdenum was significantly positively correlated with the pH, percentage base saturation, CEC and exchangeable Ca; it was negatively correlated with the clay content. 3. Deficiency of molybdenum is hardly to be expected in arid and subarid soils (24 per cent of all samples deficient). The proportion of samples with a low Mo content and the probability of Mo deficiency increases in this order: vertisols (40%) leads to fersiallitic soils (64%) leads to ferallitic soils (89%).


Sulfate reduction in poorly-drained soils as influenced by organic matter and soil texture. Investigations of the influence of added organic matter content (rice straw or clover) on the reduction of added sulfate (8 meq/100 g soil) following submergence and incubation of 120 days gave these results: 1. In soils with native organic matter (humus) the rate of sulfate reduction was very low; it slightly increased with increased clay content of the soils. 2. The addition of undecomposed organic matter led to a complete reduction of the added sulfates within 120 days. 3. The varying C/N ratio of the added organic matter appeared to have no influence on the sulfate reduction. 4. As a qualitative indication of the reduction the soil darkened after three weeks of incubation, and an odour of H2S was detected.


A preliminary study of the genital organs of indigenous cows in Uganda. As a basis for the clinical diagnoses of reproduction disturbances in indigenous cows in Uganda the normal and diseases conditions of the reproductive organs of 438 Ankola and Nganda cows slaughtered at Mukono were examined. Gravid genitals formed 30.13% of the whole material, the proportion of abnormal genitals was 39.28%. Bursitis, salpingitis, and ovario-bursal adhesions were the most prevalent abnormalities. Genital tuberculosis was found in 3.02% of the material. Ovarian dysfunctions were frequent in otherwise normal genitals: anovulation 31.44%, inactive ovaries 12.16%, follicular cysts 3.9%, cystic corpora lutea 0.56%, ovarian hypoplasia 1.12%. The individual findings are summed up in 7 tables. Four figures are added showing ovario-bursal adhesions and uterus ovarian tuberculosis. 54 references.


[Cryotherapy of skin diseases (preliminary report)]. The cryotherapy is a simple, elegant and reliable method that can often be applied in out-patients, without anesthesia. The initial apparent failures were mainly due to the fact that the time of application of the cold had been too short, or that the region in which it had been brought to bearing was too small. Clinical and histological examinations have confirmed the good cosmetic results of the method despite an extraordinary deep action. The method has only two minor disadvantages: histological controls cannot be performed, and the non-bloody artifical necrosis must be protected for 2-3 weeks by the local administration of antibiotics.


A comparison of three methods of detecting ventricular incoordination in man, and the relation of their results to the amount of coronary arteriosclerosis. The results secured by three tests for cardiac incoordination have been compared in over 100 cardiac cases. The Bcg found the abnormality more frequently than did Vgm and PDmax, the probable reasons for this are discussed. The cases in which cardiac incoordination was detected showed, on the average, more coronary arteriosclerosis than those whose hearts beat normally.


The Bcg for measuring cardiac output in a California Gray Whale. Resting cardiac output can be predicted reasonably accurately from body mass in man and other mammals. We measured the stroke volume of a 4,500-kg whale and found that Iberall's formula holds true even when body mass is very large. In addition, the Bcg acceleration trace and cardiac indices were remarkably similar to those of 20-gram and 70-kg mammals, mouse and man.


On the classification of ballistocardiograms. An improvement of Brown's classification is described... The new classification reflects the amplitude and time-relation changes of the Bcg. A method for estimating the mean values of Bcg elements, based on the principle of calculation of all corresponding values during the complete 2-3 respiratory cycles is described


Cardiac typing and the diagnostic challenge of the preinfarction state by direct body ballistocardiography. The proposed sensitivity of the DB-Bcg enables its gradation into four types-two normal, two abnormal. Their response to exercise shows specificity-amplified in the former, decreased in the latter. Illustrative material reveals deterioration of DB-Bcg forms with the earliest signs of cardiac symptomatology and is correlated with arteriographic evidence of coronary disease. This could not be corroborated either by the ECG, even post exercise, or changes in the PEP/LVET ratio. Improvement of the DB-Bcg following bed rest and/or therapy and by-pass grafting have been observed. Early application of the DB-Bcg, particularly in the young individual, may help meet the challenge of cardiac mortality.


Mathematical model of Bcg: comparison of ULF and DB. The DB and ULF accelerations are expressed in terms of arbitary time-dependent forces acting on the heart and on the body frame. For an appropriate choice of these forces, a normal DB and ULF and acceleration Bcg is reproduced. By reducing the coupling, between the subject and platform, the DB Bcg is changed successively until it is identical with the ULF Bcg.


Studies on the effects of furazolidon and P-rosaniline on the kinetoplast of Trypanosoma gambiense in mice. p-Rosaniline-sensitive and -resistant strains of Trypanosoma gambiense were separately passaged in mice treated with furazolidon. After 10 serial passages in mice, the trypanosomes were found to be resistant to furazolidon when tested in mice. The rate of appearance of AK forms after injection of furazolidon into mice infected with a clone obtained from the p-rosaniline resistant strain by repeated treatment with furazolidon (WRF) was lower than that in mice infected with a clone obtained from the p-rosaniline sensitive strain by the same treatment with furazolidon (WSF). Moreover, WSF was resistant to p-rosaniline, although it had not been exposed to it. These results indicate that there is an interaction between the actions of furazolidon and p-rosaniline on the kinetoplast. The existence of this interaction was supported by electron microscopic observations on the kinetoplasts of trypanosomes after the injection with p-rosaniline and furazolidon into mice infected with the p-rosaniline resistant clones, WSF and WRF.


Maple syrup urine disease: branched-chain amino acid concentrations and metabolism in cultured human lymphoblasts. The intracellular concentration of free leucine, isoleucine, and valine and their metabolism were studied in lymphoblast cultures established from peripheral blood of an individual with maple syrup urine disease (MSUD) and a control subject. Branched-chain alpha-keto acid decarboxylase activity in the MSUD cells was 10% or less of the control value as measured by the ability of the cells to release 14CO2 from the corresponding [1-14C]labeled branched-chain amino acid. The intracellular concentrations of free leucine and isoleucine were increased three-fold in MSUD lymphoblasts as compared to control cells. Free valine was present in only trace amounts of less than 0.1 mM in both cell lines. Exposure of normal and mutant cells to a 10 mM load of leucine, isoleucine, and valine revealed in a comparable concentration within cells after 24 hr. Concentrations returned to base values in normal cells 12 hr after removal of load, but leucine remained elevated in MSUD cells after 3 days. Leucine and its keto acid, alpha-ketoisocaproic acid, added to the culture medium gave significant growth inhibition of MSUD lymphoblasts but not of normal cells, in the millimolar range. Isoleucine, valine, and their keto acids had no effect.


Characterization of ADP-glucose pyrophosphorylase from shrunken-2 and brittle-2 mutants of maize. Electrophoretic characterization of adenosine diphosphate glucose pyrophosphorylase from the developing endosperms of nine shrunken-2 and four brittle-2 mutants revealed that (1) all mutants had low but detectable levels of activity, (2) mutation at either locus decreased activity of pyrophosphorylases A and B, and (3) differences in mobility were not found. However, pyrophosphorylase B extracted from several shrunken-2 and brittle-2 mutants differed from normal in extent of urea denaturation, Km (glucose-1-phosphate) or type of glucose-1-phosphaociation with the sh2 locus) appears to differ from normal in Km (glucose-1-phosphate).


Genetic variation in two widespread species of salamanders, Taricha granulosa and Taricha torosa. Two species of the genus Taricha are widely distributed. T. granulosa ranges from southern Alaska to central California. T. torosa is comprised of two described subspecies, T. t. torosa, which occupies much of the coast ranges of California, and T. t. sierrae, which inhabits the western slopes of the Sierra Nevada Mountains. A starch gel electrophoretic survey for genetic variation at 34 loci in four population samples of T. granulosa and at 40 loci in five population samples of T. torosa reveals differences among these taxa both in amounts of intrapopulational variability and in patterns of geographic variation. Average observed heterozygosity is 9.6% +/- 0.3% in T. granulosa, 3.3% +/- 0.5% in T. t. torosa, and 7.2% +/- 1.2% in T. t. sierrae. Average numbers of alleles per lon T. t. sierrae, and lowest in T. t. torosa. Oregon and California granulosa are genetically nearly as different as the subspecies of torosa, but geographic variation is continuous in the former. T. torosa on the other hand is comprised of three distinct gene pools--T. t. sierrae and northern and southern races of T. t. torosa. Strikingly different amounts of intrapopulational genetic variation and patterns of geographic variation may be explained by steady-state species differences, but historical causes may also exist.


Developmental specificity and evolution of the acid phosphatase isozymes of Triticum aestivum and its progenitor species. The tissue and developmental specificities of the acid phosphatase (ACPH) isozymes of Triticum aestivum and its progenitor species T. turgidum and T. tauschii have been determined and compared using the zymogram technique. Tissue and/or developmental variation in relative staining intensity, suggestive of variation in the quantity of active enzyme present, was observed for each of the seven major isozymes expressed. Isozymes homologous to each of the major isozymes of the hexaploid were detected in one or the other of the progenitor species. No difference in the pattern of developmental or tissue specificity was observed between the species for any isozyme. However, ACPH-4, encoded by ACph4, a structural gene linked to chromosome 4A, differs in electrophoretic mobility between T. aestivum and T. turgidum, indicating that divergence has occurred between these species at the Acph4 locus since the origin of the hexaploid. The molecular weight of each of five ACPH isozymes of the hexaploid was determined to be approximately 58,000. This finding, plus the results of the developmental study and the earlier demonstration that the structural genes for six isozymes (includinomosomes, provides evidence in support of the suggestion that the ACPH structural genes of hexaploid wheat are homoeologous related.


Genetic regulation of storaage protein content in maize endosperm. Sodium dodecylsulfate-polyacrylamide gel electrophoresis reveals that zein prepared from normal maize inbred (Zea mays L.) contains six separable components. Z1 and Z2 are the predominant species, with molecular weights of 21,800 and 19,000 daltons. Amino acid analysis of these two components shows that both are rich in glutamic acid, leucine, and proline, but low in lysine. Of the four minor bands, Z3, Z4, Z5, and Z6, the latter two exist only in trace amounts. A mutation at the opaque-2 locus severely suppresses the synthesis of Z1. The nonallelic mutant, opaque-7, strongly suppresses the synthesis of Z3 and Z4, while slightly reducing Z2. On the other hand, the floury-2 mutant appears to reduce the synthesis of these six proteins in the same relative proportion. In the double mutant combinations, opaque-2 apparently is epistatic to opaque-7 and floury-2 in the synthesis of zein components. The glutelin fraction shows a more complex banding pattern; however, qualitative differences are not apparent among the mutant lines examined.


Pressure-flow-volume relationships in pulmonary circulation of normal highlanders. Pulmonary vascular pressures and blood flow were measured with and without unilateral pulmonary arterial occlusion (UPAO) at rest and during exercise in 10 normal highlanders at La Paz, Bolivia (altitude, 3,750 m). In 6 other highlanders at rest and during exercise, pulmonary pressures, flow, and blood volume were measured during air breathing (PIO2 congruent to 100 Torr) and 29-30% oxygen (PIO2 congruent to 150 Torr). During air breathing, pulmonary vascular resistance was elevated at rest and did not change with exercise. Pulmonary arterial pressure rose less at rest with UPAO than during exercise without UPAO, and pulmonary vascular resistance was less in the former. Raising PaO2 to normal sea-level values had no effects on the pulmonary circulation at rest but prevented to a large extent the rise in pulmonary arterial pressure during exercise. Hence pulmonary vascular resistance during exercise was lower with oxygen than without. Thus, hypoxic vasoconstriction contributed to the pulmonary hypertension during exercise in normal highlanders. Circumstantial evidence suggests that this is related to the profound mixed venous hypoxemia caused by exercise in a hypoxic environment.


Sodium and potassium metabolism in the dehydrated and rehydrated Bedouin camel. The effects of 10 days dehydration and rapid rehydration on the sodium and potassium metabolism in the one-humped camel were examined. The research was carried out during two periods in the summer, a cool and a hot period. In the hot period the effects of dehydration were found to be more severe. The potassium metabolism was more affected than that of the sodium. The concentrations of potassium in the urine declined while those of sodium increased. There were also marked changes in the filtered loads, excreted loads, and reabsorption of the two cations. Following rehydration significant changes in the cation metabolism were recorded within 15-45 min. It is suggested that antidiuretic hormone and not aldosterone caused the changes in the two-cation metabolism.


Plasma angiotensin II levels in hypoxic and hypovolemic stress in unanesthetized rabbits. Plasma levels of angiotensin II were determined by radioimmunoassay in unanesthetized white rabbits exposed to acute hypoxia (FIO2 10% for 10 min), chronic hypoxia (0.5 atm up to 16 days), or hypovolemic stress (bleeding 20 ml/kg). Angiotensin II levels significantly decreased after 10 min of acute hypoxia in normal rabbits and significantly increased when the same procedure was applied to animals previously exposed to hypoxia by 6-8 days of permanence in the hypobaric chamber or sodium deprivation. Chronic hypoxia resulted in a temporary increase of angiotensin II already evident on the 3rd day, but maximal at the 9th day with return to normal values within 16 days. Hypovolemic stress resulted in the expected rise of angiotensin II levels 10 min postbleeding both in normal and acclimatized rabbits. The response of the renin-angiotensin-aldosterone system to hypoxic and hypovolemic stress is different. The direction and magnitude of the response to hypoxia depends on the underlying state of activation of the system and the cardiovascular condition of the animal at the time of hypoxic stress.


Cyclic hypoxic pulmonary vasoconstriction induced by concomitant carbon dioxide changes. We examined the stability of acute lobar hypoxic pulmonary vasoconstriction. In 12 mongrel dogs the left lower lobe (LLL) was selectively ventilated with a constant minute molume with nitrogen and the electromagnetically measured fraction of the cardiac output perfusing the LLL and the LLL end-tidal CO2 concentration were observed for 1 h. We found that both the fraction of the cardiac output perfusing the LLL and the LLL end-tidal CO2 concentration initially decreased during LLL hypoxia and then oxcillated in a progressively damped fashion. When LLL end-tidal CO2 was kept constant by CO2 infusion during LLL hypoxia or when LLL hypoxia was induced by LLL atelectasis, no oscillations were observed. We conclude that if minute ventilation of a hypoxic area of lung is kept constant, then decreased regional blood flow decreases regional alveolar PCO2. As a consequence of these two opposing influences, blood flow to an acutely hypoxic area will be oscillatory.


Premotion silent period in rapid voluntary movement. The silent period in the agonist prior to rapid voluntary movement (premotion silent period) was observed in the lower limb muscles. The subject was asked to respond to the flashing light by performing a vertical jump as quickly as possible. The most consistent results were obtained in the extensors, particularly the quadriceps. The frequency of the silence of six subjects was 53% in the rectus femoris, 61% in the vastus medialis, and 72% in the vastus lateralis. A neural switching mechanism, directing excitation from preparation phase of jumping into rapid contraction phase, seemed to be attributable to the occurrence of the premotion silent period.


Effect of posture on the single-breath oxygen test in normal subjects. The effect of posture on phase III (alveolar nitrogen plateau) and phase IV (closing capacity) of the single-breath oxygen test was examined in 10 normal people. In part 1 of the study, subjects inspired and expired in the standing, supine, prone, and right lateral decubitus positions; there was no effect of posture on phase IV but slopes of phase III were higher when subjects were in the supine and lateral positions. In part 2, subjects inspired in the standing position and expired in one of the recumbent positions. Phase IV occurred infrequently except in the prone position (6 of 10 subj); slopes of phase III in part 2 were not consistently altered by changing posture. It is difficult to explain the failure of posture to alter phase IV solely on a model requiring a linear gradient of pleural pressure. The slope of phase III appears to depend more on the emptying patterns of small regions with widely varying volume-to-ventilation ratios than on gravity-dependent sequences of emptying. Finally, the data suggest a considerable similarity between the upright and prone positions in terms of lung filling and emptying.


Influence of posture on flow dependence of distribution of inhaled 133Xe boli. The second 100 ml of gas inspired at constant flow rates (V) from 0.1 to 2.5 l/s was tagged with 133Xe to determine the apicobasal bolus distribution ratio (VAlvA/VAlvB) for seven normal subjects in both the upright and supine postures. Gas was preferentially distributed to the base at low V. As V increased, redistribution to the apex occurred but was greater in the supine posture. As apicobasal time constant differences should be minimal in the supine posture, the greater flow dependence of bolus distribution suggests that the pressure swing was greater over apical zones than basal zones. Model studies indicate that the pressure differences (deltaPd) necessary to predict the measured VAlvA/VAlvB at all flow rates are less than 1.0 cmH2O. Such sensitivity of gas distribution to deltaPd at both low and high flow rates makes it appear relatively insensitive to regional compliance and resistance.


Effect of water temperature during cold exposure on thermogenic drinking in rats. Availability of water at temperatures higher than ambient (15, 25, 35 degrees C) failed both to affect the ratio of water to food intake during exposure to cold air (5 degrees C) and to influence the thermogenic (postcold exposure) drinking response of rats which characteristically occurs immediately after removal from cold air. Thus, availability of warm water during exposure to cold appeared to have no influence on cold-induced dehydration in rats. A specially constructed drinking apparatus was used in this study. It was designed to maintain water at temperatures greater than ambient during exposure to cold. Details for construction of the apparatus are provided.


Sighing in newborn human infants: role of inflation-augmenting reflex. To investigate the reflex mechanisms of sighs (spontaneous large breaths) (VT greater than 2 X control VT) in infants, recordings of respiratory flow and tidal volume (VT) were made during sleep. The frequency of sighs was greater at 1 than at 5 days of age, while respiratory frequency and control VT did not change. Most sighs (93%) had a biphasic pattern of inspiratory flow characterized by an inspiratory duration nearly twice that of control breaths, with an abrupt change in flow rate halfway through inspiration. Interruption of ventilation (3-7 s of airway occlusion) appeared to generate a stimulus for biphasic sighs, since sighs occurred during the first breath after termination of airway occlusion more frequently after long than after brief occlusions. However, a biphasic inspiratory pattern in airway pressure was rarely observed while the airways were occluded, regardless of occlusion duration. This suggests that increase in lung volume during the initial part of the biphasic inspiration following occlusion is a stimulus for the second part. Thus the underlying reflex mechanism of sighs in human infants appears to be the same as occurs in the so-called Head's paradoxical response to lung inflation.


Ventilatory muscle strength and endurance training. We studied respiratory mechanics in young volunteers before and after 5-wk training programs limited to the ventilatory muscles. Four strength trainers (S) performed repeated static maximum inspiratory and expiratory maneuvers against obstructed airways. Four endurance trainers (E) performed voluntary normocarbic hyperpnea to exhaustion. Subjects spent 30-45 min each day in these exercises, 5 days a week. Four control subjects (C) did no training. We attempted to minimize the effect of learning. S increased pressure maximums by about 55%, but vital capacity and total lung capacity by only about 4%. Initially all subjects could sustain hyperpnea at about 81% of their control 15-s maximum voluntary ventilation (MVV) for 15 min; E increased this to about 96% and increased their MVV by 14% as well. No other statistically significant changes were recognized in any group. We conclude that ventilatory muscle strength or endurance can be specifically increased by appropriate ventilatory muscle training programs.


Terminal nitrogen rise.

Terminal nitrogen rise. Eighteen-breath nitrogen washouts were performed on eight subjects. Each washout could be simulated by a four-compartment model, each compartment with a different ventilation-to-volume ratio and a variable contribution to expiratory flow. In large breaths initiated near residual volume, a terminal nitrogen rise (TNR) was seen. To account for the TNR with this model, there were relatively small changes in flow from compartments with markedly different nitrogen concentration. Reasons are given for believing these compartments could not be the upper and lower lung. Three of these subjects were studied in the supine, seated, and head-down positions. The TNR was seen at the same lung volume in all positions. At routine bronchospirometry in a second group of subjects, sampling with small catheters during a nitrogen washout showed a TNR in the expirate of lungs, lobes, segments, and subsegments in the upright and supine positions. Apparently a large vertical hydrostatic gradient is unnecessary to produce a TNR. Finally, the TNR was shown to occur at that lung volume where transpulmonary pressure is very small and changing rapidly with volume. This TNR was often followed by a terminal nitrogen fall while the lung was continuing to empty. The TNR occurs when flow from a large poorly ventilated compartment increases relative to the flow from other compartments. A model of lung in which the poorly ventilated compartment develops high specific compliance at low lung volume explains these data.


Growth hormone in exercise: comparison of physiological and pharmacological stimuli. This study was designed to compare the serum growth hormone (GH) response with quantified exercise to that obtained with other stimuli. In eight normal males, aged 21-24 yr, we studied the serum GH response to 20 min cycle ergometer exercise at 300, 600, and 900 kpm/min on three separate occasions and compared the results with those found during sleep, insulin hypoglycemia, arginine infusion, and L-DOPA. Exercise at 900 kpm/min and insulin hypoglycemia resulted in the greatest elevations in serum GH which were significantly greater than those found with sleep, arginine or L-DOPA. The 20-min exercise at 900 kpm/min represented 75-90% of the subjects' maximal oxygen uptake and is a suitable provocative test for GH secretion. As a screening test for pituitary GH reserve, exercise compares favorably with insulin hypoglycemia and is superior to sleep, arginine, and L-DOPA.


Metabolic cost of grade running in dogs. Dogs (Canis familiaris) were run up and down 7.4, 11.8, and 20.4% grades as well as on the horizontal at speeds of 3 and 6 km/h while their steady-state oxygen comsumption was measured. On positive grades the metabolism was directly dependent on both grade and speed. On the negative grades the metabolic rates were dependent only on speed and for each dog were depressed about the same amount below the metabolism needed for horizontal running at each speed. The clustering of the metabolic rates for the downhill slopes means that to cover a given distance gorizontally and downhill the dog will use the minimum energy if it descends via the gentlest grade. This is so because such a route allows the animal to maintain the lowest metabolism for the longest time. There is no best uphill route. The grade metabolism of the dogs was an almost exact duplicate of that found for humans running on grades which implies similarity of mechanical and biochemical aspects of running.


Phrenic nerve activity and occlusion pressure changes during CO2 rebreathing in cats. Changes in phrenic nerve activity, quantified as a moving time average, PNG(t), were characterized during complete airway occlusion at functional residual capacity (FRC) and compared to simultaneously occurring changes in intratracheal pressure. In anesthetized cats breathing room air and during CO2 breathing, PNG(t) during occlusion was the same as that found during unobstructed breathing until it reached a value approximately corresponding to that at peak inspiration in the preceding unoccluded breath, the rate of change of PNG(t) usually remained the same but in a few cases (2 out of 11) increased. When intratracheal occlusion pressure was plotted as a function of PNG(t), both while breathing room air and during CO2 rebreathing, an approximately linear relationship was obtained. Thus, changes in intratracheas occlusion pressure obtained at FRC parallel changes in phrenic motor nerve activity. Quantification of electrical activity of respiratory nerves as a moving time average provides a means of characterizing changes in the average level of electrical activity during an inspiratory effort.


The unactivated form of the first component of human complement, C1. The first component of complement, C1, was isolated unactivated from human serum by repeated additions of di-isopropyl phosphorofluoridate during isolation. The unactivated subcomponents were also isolated, and evidence is given that the three subcomponents C1q, C1r and C1s account wholly for the activity of component C1 in serum. No evidence could be found for a fourth subcomponent, C1t. The approximate molar proportions of the subcomponents in serum are C1q/C1r/C1s = 1:2:2. Optimum activity by haemolytic assay was found at approximate molar proportions C1q/C1r/C1s of 1:4:4. No activity was found when subcomponents were assayed singly or in pairs, except for subcomponents C1q and C1s, which in molar ratio 1:4 gave 15-20% of the activity of the mixture C1q + C1r + C1s. The proteolytic activity of the isolated subcomponent C1s varied according to the method of activation used. Subcomponents C1q + C1r + C1s and C1q + C1s in the presence of antibody-antigen aggregates were activated and inactivated simultaneously, showing a peak of activity and subsequent loss of activity. Both reactions are probably due to proteolysis, and analysis of the peptide bonds split will be necessary to distinguish these two phenomena.


Anaerobic threshold and maximal aerobic power for three modes of exercise. Alterations in selected respiratory gas exchange parameters have been proposed as sensitive, noninvasive indices of the onset of metabolic acidosis (anaerobic threshold (AT) during incremental exercise. Our purposes were to investigate the validity and feasibility of AT detection using routine laboratory measures of gas exchange, i.e., nonlinear increases in VE and VCO2 and abrupt increases in FEO2. Additionally, we examined the comparability of the AT and VO2 max among three modes of exercise (arm cranking, leg cycling, and treadmill walk-running) with double determinations obtained from 30 college-age, male volunteer subjects. The AT's for arm cranking, leg cycling, and treadmill walk-running occurred at 46.5 +/- 8.9 (means +/- SD), 63.8 +/- 9.0, and 58.6 +/- 5.8% of VO2 max, respectively. No significant difference was found between the leg exercise modes (cycling and walk-running) for the AT while all pairwise arm versus leg comparisons were significantly different. Using nine additional subjects performing leg cycling tests, a significant correlation of r = 0.95 was found between gas exchange AT measurements (expressed as % VO2 max) and venous blood lactate AT measurements (% VO2 max). We conclude that the gas exchange AT is a valid and valuable indirect method for the detection of the development of lactic acidosis during incremental exercise.