Attainment and maintenance of normal stature with alkali therapy in infants and children with classic renal tubular acidosis. Growth was evaluated in a group of 10 infants and children with familial or idiopathic classic renal tubular acidosis in whom alkali therapy was initiated at ages ranging from 8 days to 9.5 yr and administered at dosage schedules documented to sustain correction of acidosis in at least four prolonged observation periods on the Pediatric Clinical Research Ward. When alkali therapy was begun, six patients (four infants and two children) were stunted (height <2.5 SD below mean). Of the four who were not, two infants were too young (<2 wk of age) to have become stunted, and two children had been documented earlier to be nonacidotic. At the start of alkali therapy, the heights of the patients correlated inversely with the maximal possible duration of prior acidosis. WITH SUSTAINED ALKALI THERAPY: (a) each patient attained and maintained normal stature; (b) the mean height of the 10 patients increased from the 1.4+/-4 to the 37.0+/-33 percentile (of a normal age- and sex-matched population); (c) the mean height reached the 69th percentile in the eight patients whose heights could be analyzed according to parental prediction (Tanner technique); (d) the rate of growth increased two- to threefold, and normal heights were attained within 6 mo of initiating alkali therapy in the stunted infants and within 3 yr in the stunted children; (e) the height attained correlated inversely with the maximal possible duration of acidosis (before alkali therapy) only in those patients in whom alkali therapy was started after 6 mo of age, and not in those treated earlier. The amount of alkali required to sustain correction of acidosis increased substantially during the course of treatment in each patient. The maximal alkali requirement ranged from 4.8 to 14.1 meq/kg per day, and in each patient its amount was determined principally by the magnitude of renal bicarbonate wasting.


Abnormal sialic acid content of the dysfibrinogenemia associated with liver disease. To evaluate the possibility that the carbohydrate composition of fibrinogen may be altered in the dysfibrinogenemia associated with liver disease, we studied the sialic acid content of purified fibrinogen from 12 patients with liver disease and its relationship to the prolongation of the thrombin time. Purified fibrinogen showed that Aalpha-, Bbeta-, and gamma-chains when reduced and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and exhibited prolongation of the thrombin time similar to that of the plasma from which it was derived. Sialic acid content of the purified fibrinogen ranged from 12.7 to 71.4% higher in patient fibrinogens when compared to normal controls. A progressive delay in thrombin time was associated with increasing sialic acid content of the patient fibrinogen. Enzymatic removal of sialic acid from four of the abnormal fibrinogens resulted in a shortening of their thrombin times to the range of the desialylated normal control. Periodic acid-Schiff reagent stained only the Bbeta- and gamma-chains of the reduced patient fibrinogens after sodium dodecyl sulfate-polyacrylamide gel electrophoresis suggesting that the excess sialic acid is located on these two chains. These studies demonstrate a biochemical alteration of the functionally abnormal fibrinogen found in some patients with liver disease, and indicate that the excess sialic acid plays an important role in the functional defect of this protein.


The retinotopic organization of lateral suprasylvian visual areas in the cat. This is the second in a series of papers in which we describe our continuing efforts to define functional units of visual cortex based upon electro-physiological mapping of single and multiple unit activity in both awake and the nitrous oxide anesthetized cats. In the first paper (Tusa, Palmer and Rosenquist, '78), the extent and retinotopic organization of area 17 were described. In this paper, we describe the somewhat more complex organization of the visual cortex lying on the banks of the middle and posterior suprasylvian sulci. This region of cortex consists of six retinotopically organized units. These areas are arranged as three roughly mirror symmetrical pairs separated in each case by the fundus of the middle or posterior suprasylvian sulci. Some thalamo-cortical autoradiographic material is presented which supports this parcellation of the cortex.


Expansion of the half retinal projection to the tectum in goldfish: an electrophysiological and anatomical study. The topographical retino-tectal projection of goldfish was electrophysiologically mapped at various intervals after surgical removal of the nasal half of the retina and pigment epithelium. The remaining projection was initially restricted to the appropriate rostral half of the tectum, even if the nerve was crushed and allowed to regenerate. But later, after 137 days or more, it showed a progressive expansion onto the foreign caudal half of the tectum. The magnification factor, the number of micrometers of tectum per degree in the visual field, doubled in the rostro-caudal but not in the medio-lateral direction. Analysis of the sequence of the expansion showed that a few fibers originally projecting nearest the denervated area were the first to spread over it. Then, progressively more fibers moved caudally until a nearly uniform representation of the half retina was established on the tectum. Radioautography also demonstrated that retinal fiber terminals had invaded the caudal tectum. The retinae of these fish were also examined histologically. The density of ganglion cells had not increased, but they consistently showed the axonal reaction. This was not found to be associated with any initial surgical trauma, but rather with the movement of their fiber terminals within the tectum. Frozen sections through half retinal and normal eyes, were cut and photographed for comparison of ocular geometry. Operated eyes were normal except for a slight but consistent loss of ocular volume. Analysis of the optical geometry showed that recording with fish in air produced two effects: Myopia (10 degrees blur circle, or less) and enlargement of the visual field by 15 percent to 20 percent.


Categories of axons in the inferior cardiac nerve of the cat. Myelinated and unmyelinated axons in the inferior cardiac nerve of the cat were examined to determine how many axons were (1) sensory, (2) preganglionic sympathetic, and (3) postganglionic sympathetic. In one group of cats, a segment was removed from the middle of the inferior cardiac nerve as a control, and the proximal and distal stumps of the nerve were examined one week later. In another group of cats, the control segment of nerve was removed and the first thoracic white ramus communicans and sympathetic trunk were cut proximal to the stellate ganglion, followed in one week by examination of the proximal and distal stumps of the inferior cardiac nerve. In still another group of cats, the first five thoracic spinal nerves were cut just distal to the dorsal root ganglion. The counts of myelinated and unmyelinated axons after these surgical procedures indicated that, in the cat inferior cardiac nerve, all or almost all of the approximately 30,000 unmyelinated axons and 10 percent of the myelinated axons are postganglionic sympathetic fibers, and that approximately 90 percent of the myelinated axons are sensory.


Autoradiographic maps of regional brain glucose consumption in resting, awake rats using (14C) 2-deoxyglucose. The 2-deoxy-D-[14C]-glucose (2-DG) autoradiographic method for determining regional brain glucose consumption has been applied successfully by a number of workers for mapping the alterations of brain glucose consumption which occur in association with experimental alterations of brain functional activity. This paper provides a framework for the interpretation of these and further studies by presenting: (1) the pattern of regional brain glucose consumption in the normal, resting, awake rat; (2) the anatomical identities of brain structures which on autoradiographs appear only as regional variations of optical density. For this purpose, a series of 2-DG autoradiographs of coronal brain sections from an injected animal is compared with adjacent labeled Nissl sections.


Bovine milk N-acetyl-beta-D-glucosaminidase and its significance in the detection of abnormal udder secretions. A new spectrofluorimetric assay procedure for bovine milk N-acetyl-beta-D-glucosaminidase (NAGase) is described for use as a routine screening test for the detection of abnormal udder secretions. This procedure uses 4-methylumbelliferyl-N-acetyl-beta-D-glucosaminide as substrate. On the basis of the greater sample throughput, increased product sensitivity detection of NAGase and the absence of turbidity problems, it is considered to be superior to a previously reported spectrophotometric procedure (Kitchen, 1976). The correlation coefficient between the somatic cell count and the fluorimetric procedure using 243 quarter fore-milk samples was 0.86. Distribution studies on bovine milk and mammary gland homogenates indicated that this enzyme activity was located predominantly in the soluble whey protein fraction and the post-microsomal supernatant. Mammary gland secretory cells contained high levels of NAGase and appeared to be the major source of the enzyme in milk whilst NAGase from other sources (white blood cells, blood serum) contributed only a minor proportion (5-15%) of the total activity in milk. The implications of these findings on the value of the NAGase test as a means of mastitis diagnosis are discussed.


The management of arrhythmias following an acute myocardial infarction. Arrhythmias are extremely common early after AMI. An arrhythmia is defined by exclusion, either because the sequence of myocardial depolarisation is other than normal or because certain arbitrary limits are exceeded. It follows that the term "arrhythmia" encompasses a complex heterogenous group. Although arrhythmias are defined in electrical terms they are only important because of their immediate, delayed or potential haemodynamic consequences. These occur because of changes in heart rate, loss of atrial transport function, increased myocardial oxygen consumption, decreased myocardial blood flow or loss os synchronicity of ventricular contraction. The sensible and effective management of arrhythmias following acute myocardial infarction requires an appraisal of the haemodynamic consequences, if any, which follow the initiation of the arrythmia. The indications for treating an arrhythmia must be the immediate, delayed or potential haemodynamic loss rather than the mere presence of a rhythm which falls outside the limits of normal. This distinction is perhaps most clearly seen in the case of atrio-ventricular conduction disturbances.


The measurement and control of myocardial infarct size. Direct, chemical, electrocardiographic and radio-isotopic methods are described for the estimation of myocardial infarct size in animals and man. Their relative points and failings are discussed. The effects of interventions, physical, metabolic and pharmacological, upon the size of myocardial infarcts, are examined and work attempting to reduce myocardial infarct size in man reviewed.


Mechanical circulatory assistance by intra-aortic balloon pumping for the treatment of cardiogenic shock. Although the shock state due to acute myocardial infarction may be reversed by IABP in 80 per cent of patients, 55 to 65 per cent remain balloon-dependent. Therefore some attempt to correct the underlying anatomic abnormalities (reversible ischaemic areas and/or mechanical defects) appears necessary if these patients are to survive. With IABP catheterization studies performed in these critically-ill patients are well tolerated. Myocardial depression after cardiopulmonary by-pass is often related to subendocardial ischaemia. The combination of IABP and surgery has resulted in survival of approximately 50 per cent of patients in cardiogenic shock secondary either to a mechanical defect complicating myocardial infarction or to open-heart surgery.


Treatment of mediastinitis in children after cardiac surgery. A study of 20 cases. Twenty-three cases of mediastinitis after cardiac surgery in children were treated by us between 1973 and 1976. Three patients died within 6 hours of admission. Treatment used in the tweny other cases are discussed. The mean age of the patients was three years and three months. The mediastinitis was evident an average of twelve days after extracoporeal circulation. A staphylococus was always responsible for the infection. Treatment was a combination of surgery, antibiotics and respiratory and nutritional supplies. The surgical treatment consisted of a careful mediastinal cleansing with resection of the sternal edges. In fifteen patients the thorax was closed after surgery, and an irrigation system installed using a solution of 4% Dakin in physiologic saline. Recovery was simple in 5 patients. In the 10 other patients of this group the thorax had to be reopened; one patient died after 90 days from Serratia marcescens endocarditis. The thorax was left open initially in five patients: one patient of this group died from candida endocarditis. All patients needed endotracheal ventilation through a nasotracheal tube (7 to 90 days of ventilation). Treatment with bactericidal antibiotics was pursued for three months and a monotherapy was kept for nine months. After reviewing the observed complications, our methods and results are compared with others in the literature.


Two mitral valve replacements during the course of a single pregnancy. A case of repeat mitral valve replacement during the same pregnancy is reported. Pre and post-operative care of the patient and her pregnancy are discussed. The hazards of anticoagulation during pregnancy are reviewed.


The first derivative of the transthoracic electrical impedance as an index of changes in myocardial contractility in the intact anaesthetised dog. The suitability of the peak value of the first derivative of the thoracic electrical impedance dZ/dtmax has been investigated in dogs as a non-invasive index of changes in myocardial contracility by comparing if with the peak left ventricular dP/dt and the peak values of aortic blood velocity and acceleration. An increase in the inspired halothane concentration was used to produce changes in contracility. In 5 dogs the combined values for the correlation coefficient between dZ/dtmax peak velocity and acceleration were respectively 0.937, 0.954 and 0.950. In 14 out 15 comparisons p less than 0.001 and in one, p less than 0.01. On these grounds, dZ/dt max is proposed as a variable worthy of sconsideration in patient monitoring.


Prehospital and hospital coronary care.

Prehospital and hospital coronary care. This article reviews the current state of services for coronary care. Since the majority of deaths from coronary heart disease occur early and outside the hospital, the importance of the prehospital phase is emphasized. The delay in this period, which is very dangerous for the patient, should be reduced and mobile coronary care units (MCCU's) are one possibility to reduce the rate of sudden coronary death. Different systems of MCCU's are discussed: (1) those based on a hospital coronary care unit, usually accompanied by a nurse and/or a doctor and (2) those integrated into an already existing decentralized emergency system (e.g. fire department) run by paramedics. Although long-term survival of patients resuscitated from ventricular fibrillation is not so good, the results of many of these units are remarkable.


The I.C.U. treatment of acute laryngotracheobronchitis in a developing country. The management of 50 children with acute laryngotracheobronchitis (LTB) in a general I.C.U. in a developing country is presented. The overall mortality was 16%, with no patient demising from LTB. It is stressed that LTB in developing countries is a very different disorder to that seen in Western societies, due to complicating factors such as bronchopneumonia, malnutrition and measles. Guidelines for therapy are proposed.


Anaphylaxis to protamine sulfate mediated by a complement-dependent IgG antibody. Anaphylactoid reactions to protamine sulfate have been attributed to its capacity for nonimmunologic mast cell degranulation and/or complement consumption. In the current study, evidence is presented for the occurrence of an immunologic anaphylactic reaction mediated by a complement-dependent IgG skin-sensitizing antibody. A retrospective study of blood component donors given protamine for heparin neutralization revealed that prior exposure to protamine is associated with increased risk of adverse reaction to the drug.


Histamine hypersensitivity in mice induced by concanavalin A. This study compared the responses of CFW and CFI mice to concanavalin A (con A) and the histamine-sensitizing factor (HSF) of Bordetella pertussis. There were marked similarities between these two agents with regard to systems implicated in induced histamine sensitivity. Con A, like HSF, induces the sensitivity in CFW but not in CFI mice. The sensitizing agents both require the same time for optimum sensitization, both induce cutaneous sensitivities to histamine, and the mice are protected from the induced susceptibility of both agents by epinephrine and by desensitization with serotonin. They differed in that con A did not induce the systemic susceptibility to serotonin or to combined histamine and serotonin which is produced by HSF. The major difference related to mechanisms of action was the failure of con A to induce a systemic beta-adrenergic blockade, the block of which is manifested in HSF-treated CFW and CFI mice by the inhibition of an epinephrine-induced hyperglycemia. The resistance of beta-blocked CFI mice to histamine, and the susceptibility to histamine of the unblocked CFW mice sensitized with con A, is inconsistent with the theory that susceptibility results from a systemic adrenergic imbalance, but does not preclude a local adrenergic effect as the common element in histamine-sensitizing agents.


Nutrient content of selected baby foods. Nutrient content often varies somewhat among brands of baby foods today. Dinners, such as vegetables and meat, are higher today in moisture content than when Agriculture Handbook 8 was published in 1963. Modern processing techniques may account for this difference. To combat nutritional anemia, dry cereals, often the baby's first food other than milk or formula, are excellent sources of good-quality protein and iron, as well as of copper. Asorbic acid is often added to fruits and fruit juices to improve and standardize the product. In recent years, sodium in baby foods has been reduced, due to limited use of salt and monosodium glutamate. Trends indicate less sugar will be added to fruits and juices in the future. Variation in content of selected nutrients can be attributed to the proportion of ingredients in the mixture or the variety of vegetable or fruit selected by the baby food processor.


Pathogenesis of Dupuytren's contracture: a correlative clinical-pathological study. The tissue from 38 patients with Dupuytren's contracture was submitted for light and electron microscopy. The clinical and pathological data were correlated so that three stages of disease were recognized: early, active, and advanced. The cell of early disease was the perivascular fibroblast; whereas, the cell of active disease was the myofibroblast. Because the myofibroblasts have cell-to-cell and cell-to-stroma attachments, the collagen not only becomes oriented as it is formed, but it also is subjected to a contractile force.


Experimental intrinsic healing of flexor tendons based upon synovial fluid nutrition. The healing process of totally cut and subsequently resutured rabbit flexor tendons kept isolated in the knee joint cavity and free in the synovial fluid was studied by histological and ultrastructural techniques. This experimental model represents a "tissue culture in situ," where the tendon is nourished by diffusion from the synovial fluid only and where no adhesions are formed. Under these conditions there is a proliferation of tendon cells and deposition of collagen resulting in bridging of the suture line. On the basis of these findings, it is assumed that the tendon cells possess an intrinsic potential of repair, provided they obtain a sufficient nutritional supply. In the present experimental model, this nutrition was provided by way of diffusional pathways from the synovial fluid.


Nutrient pathways to flexor tendons using hydrogen washout technique. The nutrient pathways of flexor tendons within the flexor sheath were studied using the hydrogen washout technique. Hydrogen uptake and decay of a free segment of flexor tendon detached from its blood supply were not significantly different from an intact tendon lying in the synovial bed. There was no hydrogen uptake by flexor tendons which were mechanically separated from the synovial bed, even though muscular, periosteal and vincular attachments were intact. We concluded from this study that the synovium of the flexor tendon was a significant nutrient pathway for the flexor tendon and that the blood vessels did not appear to play a significant role in the nourishment of the flexor tendon.


Recovery of function in free muscle transplants using microneurovascular anastomoses. Using the rectus femoris muscle of the rabbit, the functional capabilities of the normal and replanted muscle were studied after tenotomy, simple neurovascular repair, and orthotopic and heterotopic transplantation. Tenotomy alone altered the function more than did neurovascular repair, and although a muscle survived after replantation, it never achieved the functional capability of the normal muscle, maximum working capacity being only one fourth of the normal.


Complications of surgical release for carpal tunnel syndrome. Review of a series of 186 operative cases of carpal tunnel release revealed 34 complications in 22 patients, for an incidence of 12%. Complications were grouped into seven categories: (1) inadequate section of the transverse carpal ligament (associated with both transverse and curved incisions), (2) symptoms related to damage to the palmar cutaneous branch of the median nerve, (3) reflex sympathetic dystrophy, (4) unsightly hypertrophic scar due to inappropriate incision, (5) damage to the superficial palmar arch following blind sectioning of the transverse carpal ligament, (6) bowstringing of the flexor tendons after excision of the transverse carpal ligament, and (7) adherence of the flexor tendons following excision of the mesotenon. Except for four of the complications, two each of bowstringing and reflex sympathetic dystrophy which occurred in our own practice, all of the complications were seen in patients referred for care. Most complications can be prevented by proper operative technique.


Intraoperative changes in motor nerve conduction latency in carpal tunnel syndrome. A prospective study of 47 patients with 51 hands treated for carpal tunnel syndrome by surgical release of the deep transverse carpal ligament was performed using intraoperative motor nerve conduction latency measured over a standard distance across the carpal tunnel both before and after release of the ligament. The results of intraoperative conduction latencies indicated a dramatic and immediate reduction in the conduction latency across the carpal canal in all but seven patients, two of whom had diabetes. When the results were subjected to statistical analysis, they were significant (P is equal to 0.00001). Although further studies are indicated, these data suggest that a rapidly reversible mechanical or metabolic block, such as ischemia in the segment of the median nerve, may be responsible for the symptoms of carpal tunnel syndrome.


Personal observations on the role of the lumbrical muscles in carpal tunnel syndrome. A case of carpal tunnel syndrome is presented in which an abnormally high origin of a lumbrical muscle seemed to be the cause. Since the patient and author are the same, the symptoms of compression and during the postoperative period are well documented. Evoking the symptoms by exercise or active motion is suggested for future diagnostic tests. A surgical incision more ulnarward is recommended.


Technical problems with ulnar nerve transposition at the elbow: findings and results of reoperation. Ten patients who had persistent or recurrent paresthesias, muscular weakness, or sensory loss following transposition of the ulnar nerve at the elbow were explored. Operative findings included compression of the nerve at the intermuscular septum or at the entrance to the cubital tunnel, dense scarring after intramuscular transposition, and constriction by fascial slings. The average interval from the previous operation to re-exploration was 13 months. All patients were improved following neurolysis and submuscular transposition. Recovery was incomplete in nine patients. The average follow-up was 14.5 months.


Injury to the brachial plexus as a result of diagnostic arteriography. Six cases of brachial plexus injury within the brachial sheath are reported following axillary-brachial arteriography. Direct compression resulted from leakage of arterial blood into the space formed by the fascial sheath. In one, hemorrhage occurred several days after arteriotomy. Early decompression and arteriorrhaphy resulted in restoration of normal function. Permanent nerve damage resulted when surgical decompression was delayed.


Chronic recurrent dislocation of the proximal interphalangeal joint of the finger. Two cases of chronic recurrent dislocation of the proximal interphalangeal joint were seen after dislocation without an accompanying fracture. Reconstructive procedures prevented recurrent dislocation in both cases.


Changes in numbers and heparin content of peritoneal fluid mast cells of growing rats measured by flow cytofluorometry. A cytofluorometric method, based on berberine staining of mast cell heparin, was used for flow cytofluorometric counting and heparin quantitation of mast cells in crude peritoneal suspensions of growing rats. The automatic flow cytofluorometric counting of mast cells correlated well with hemocytometer cell counts. The mean mast cell heparin content obtained by flow cytofluorometry showed good agreement with such obtained by cytofluorometry of microscopically identified mast cells. The number of peritoneal mast cells and the mean mast cell heparin content was found to increase as the animals grew older. The results of the microscope fluorometric measurements suggested that the heparin content was normally distributed within mast cell populations of both young and old rats. However, the heparin distributions obtained by flow cytofluorometry were often positively skewed but did not fulfill the condition of the log-normal distribution.


The cytochemical demonstration of beta-glucuronidase in colon neoplasms of rats exposed to azoxymethane. Colon tumors induced with azoxymethane in male Fischer rats were cytochemically analyzed for beta-glucuronidase using naphthol AS-B1 glucuronide (6-bromo-2-hydroxy-3-naphthoyl-O-anisidine) as a substrate and hexazonium pararosanin as a diazo reagent. This method effectively localizes the bulk of beta-glucuronidase in the surface epithelium, the lamina propria and in the endothelial cells of the lymphoid sinuses and postcapillary venules. Polypoid lesions, adenocarcinomas and mucinous adenocarcinomas show no difference in the amount or in the localization of beta-glucuronidase; however, mucinous adenocarcinomas show a slight increase in the amount of beta-glucuronidase. The few tumors that did metastasize to lymph nodes did not show any difference in their enzyme patterns. Intestinal crypts that show a change in size and shape have a definite increase in beta-glucuronidase activity. An increase in the activity of this enzyme can also be seen in well defined neoplasms as opposed to normal areas of the colon.


Single radial haemolysis: a survey of antibody titres in the highland region of Scotland to recent strains of influenza A. The single radial haemolysis test is conveniently practical and economical and promises to have wide applicability in the study of influenza antibodies in human populations. It can also be adapted for preliminary examination of new virus isolates during epidemics. Using this test a rather higher proportion of the population in the Highland Region of Scotland were found to possess antibody to a recent epidemic strain of influenza (A/Scotland/74) than was the case in the south of England. Antibody was detected and apparently evenly spread throughout all but the most remote island communities. Some evidence of the spread of the subsequent variant, A/Victoria/75, was obtained. Most of the school children in our study had high antibody titres to recent strains but the proportion with high antibody titres to these strains declined speedily from the age of 17 years onwards.


Haemagglutination-inhibition antibodies against influenza A and influenza B in maternal and neonatal sera. Haemagglutination inhibition (HI) antibodies against the influenza viruses A/Hong Kong/8/68 (H3N2) and B/Nederland/77/66 were determined in 420 paired sera from mothers and newborns (umbilical cord sera), sampled in 1970-1. A higher concentration of antibodies against influenza A virus was found more frequently in neonatal than in maternal sera. By contrast, low titres against influenza B virus were more frequently observed in neonatal than in maternal sera. Maternal age, duration of pregnancy, and birth-weight did not affect the results of the tests. It is suggested that the titre of the newborn against an epidemic influenza virus can be predicted from that of the mother. Furthermore, the maternal titre may be an indication of the susceptibility of the newborn infant to influenza infections.


The effect of ABO blood groups on the incidence of epidemic influenza and on the response to live attenuated and detergent split influenza virus vaccines. The effect of blood group status on the incidence of epidemic influenza A (H3N2) infections and on serological response to influenza vaccination with killed subunit and live attenuated vaccines have been investigated during comparative vaccine trials in Western Australia. A significantly higher incidence of epidemic influenza was observed in subjects of blood group B compared with those of other blood groups, regardless of whether they had serological evidence of previous exposure to H3N2 antigens or not. Volunteers of different blood groups exhibited similar seroconversion frequencies to both vaccines after the administration of two doses, but a significantly higher proportion of blood group A subjects seroconverted after receiving their first dose of live attenuated vaccine compared with those of other blood groups. Although this finding was inconsistent with the increased incidence of epidemic influenza in subjects of blood group B, it is discussed in terms of the methods employed to obtain attenuation. Higher geometric mean HI antibody titres were observed in blood group O subjects after the administration of killed subunit vaccine. The results described in this report supported the contention that genetic factors linked to ABO blood groups may play a role in susceptibility to infection with influenza A virus, but that any association must be indirect.


Bacterial contamination in a modern operating suite, 2. Effect of a zoning system on contamination of floors and other surfaces. In this investigation the bacterial contamination of surfaces such as walls and floors in a modern operating suite, together with surfaces of lamps in the operating theatres, and the clogs worn by staff, was studied. Counts of colony-forming units were made on impression plates containing blood-agar with Tween 80 for total bacterial counts, Baird Parker medium with egg yolk and tellurite for Staphylococcus aureus and trypticase peptone agar with neomycin and polymyxin for Clostridium spp. The areas examined were divided into the patients' route to the operating theatre, the staff's route, and the central area containing the operating rooms, anaesthetic rooms, and exit and scrub-up areas. In the patients' route counts of total organisms ranged from about 10000 to 30000/m2; for Staph. aureus the range was from 70 to 540/m2. In the staff's route the highest count was about 70000/m2 in the dressing area, and the numbers of Staph. aureus were about the same as along the patients' route. In the inner zone the counts were somewhat lower for both total organisms and Staph. aureus. Total counts on the floor from all areas of the inner zone were significantly higher just before the second operation than before the first operation on the same day. The total and Staph. aureus counts on walls, floors and lamps were the same after clean operations as after operations classified as "contaminated" or "dirty".


Genetics of warfarin-resistance in house mice of three separate localities. Mice from Loughborough and Nottingham were obtained in order to compare the inheritance of warfarin resistance in these populations with that established for a Cambridge population (Wallace & MacSwiney, 1976). Using the same breeding programme and warfarin testing technique, it is established that resistance in the new areas is, as in the Cambridge area, controlled  by the major resistance gene, War, in chromosome 7, with penetrance affected by sex and modifiers. In addition, survival differences in males of different ages strongly suggests that War+ has less penetrance with age. Penetrance differences between the experiments establishes that wild populations differ in their modifier complex and that more than one modifier, probably several, exist. Questions are posed as to the adaptive significance of the phenomena, and the way in which they work, in the patchwork of warfarin baited and unbaited areas in this country.


Field trials of WBA 8119 (PP 581, brodifacoum) against warfarin-resistant infestations of Rattus norvegicus. Baiting with medium oatmeal or soaked wheat containing 0.002, 0.001 or 0.0005% brodifacoum completely controlled infestations of warfarin-resistant rats on farms when the poisoned baits were maintained until rats ceased to feed on them. The concentration of brodifacoum did not affect the duration of these treatments which lasted from 11 to 25 days. Poison baiting with 0.002% brodifacoum for only 1,4 and 7 days achieved, respectively, only about 41, 51 and 68% control of similar farm infestations, and so emphasized the need to continue baiting for longer periods.


Suppression of the plaque-forming cell response by macrophages present in the normal rat spleen. Depletion of phagocytic and/or adherent cells from normal rat spleen cell preparations permitted the generation of PFC to SRBC in vitro. Suppressive activity was associated with the presence of macrophages in the normal rat spleen, since irradiated unfractionated or irradiated adherent cells suppressed the PFC response of macrophage-depleted cells. Whereas depletion of macrophages from normal rat spleen cells permitted the PFC response to SRBC to occur, comparable treatment of mouse spleen cells eliminated the PFC response. These results are discussed in relation to the requirement for macrophages in the generation of PFC with rat cells in vitro.


Macrophage Ia antigens. I. macrophage populations differ in their expression of Ia antigens. By indirect immunofluorescence and microcytotoxicity it was demonstrated that different populations of murine macrophages bear different amounts of Ia antigens on their membranes. At least three subpopulations could be distinguished: those that lack Ia antigens and predominate in peritoneal exudate; cells bearing I-A antigens that are the majority of splenic macrophages and a minor population in the peritoneum; and cells bearing I-C antigens that are a minor population in both spleen and peritoneum. Internal radioisotope labeling studies confirmed that the I region molecules are synthesized by the macrophages. It is suggested that these different macrophage subpopulations may play distinct roles in the immune response.


Antibody-induced suppression of the fifth component of complement in mice. We have shown that administration of anti-C5 antibody to newborn mice heterozygous for C5 deficiency can suppress C5 levels for prolonged periods. This is analogous to antibody-induced immunoglobulin allotype and idiotype suppression. Only certain sources of anti-C5 are effective in suppression. Of the three antisera extensively tested in (SWR x RIII)F1 hybrids, A/He anti-RIII was the most effective, SWR anti-RIII was less effective, and SWR anti-DBA/1 was ineffective. Only certain strain combinations of F1 hybrids are susceptible to C5 suppression. C5 suppression was seen with (SWR x RIII)F1 hybrids but not (SWR x DBA/1)F1 hybrids. Kinetics of C5 suppression suggest a requirement for an active, ongoing process in the maintenance of low C5 levels.


Lactic dehydrogenase virus alteration of lymphocyte circulation. Acute infection with lactic dehydrogenase virus (LDV) causes a systemic alteration in lymphocyte circulatory patterns. Peripheral lymph nodes (LN) and spleens in acutely, but not chronically, infected mice retain a significantly greater proportion of injected 51Cr-labeled lymphocytes than the respective tissues in noninfected controls. This increase in lymphocyte localization in LN and spleen is dependent upon the dose of LDV injected and the timing of the infection. A relatively large dose of LDV (10(8) infectious units) causes an early but very transient increase in splenic lymphocyte localization accompanied by an early but prolonged increase in lymphocyte recovery in LN. Smaller doses of LDV cause more prolonged effects on splenic lymphocyte recovery and retarded effects on lymphocyte localization in LN. Increases in splenic recovery were always accompanied by decreases in hepatic recovery of lymphocytes. LDV-induced alteration in lymphocyte circulation may be responsible for many previously observed modifications of immune responses in LDV-infected mice.


Inherited deficiency of the sixth component of complement: a silent or null gene. Four families have been studied, some members of which have inherited deficiency of the sixth component of complement. The genetically determined electrophoretic variants of C6 were evaluated in all family members. Seven individuals were found who did not have the variant found in the serum of the parent from whom they inherited the deficiency. It is inferred that the isolated low levels of C6 in these individuals results from the heterozygous state of a normal C6 variant gene and a silent or null C6 gene; the genes determining electrophoretic variants and the low serum levels of C6 are allelic.


Specific functional and immunologic assay of plasma plasminogen in hereditary angioedema, in hereditary angioedema treated with tranexamic acid, and in normal subjects. Plasma plasminogen levels were determined by a specific esterolytic assay and a radial immunodiffusion assay, both of which were standardized on a weight basis by using highly purified plasminogen diluted in plasminogen-free plasma. In thirteen normal individuals the functional and antigenic levels were 275 +/- 61 microgram/ml and 285 +/- 61 microgram/ml, respectively (r = 0.95), whereas in 58 plasmas from individuals with hereditary angioedema the levels were 272 +/- 58 microgram/ml and 265 +/- 64 microgram/ml, respectively (r = 0.89). In two patients treated with tranexamic acid either acutely or chronically, both the functional and antigenic plasminogen levels were diminished.


Suppression of experimental allergic encephalomyelitis by 6-hydroxyphthalaldehydic acid, O-(p-chlorobenzyl)oxime (EN3638). EN3638 is a new oxime derivative of salicylic acid that has immunosuppressive properties. Oral administration of the compound to rats during the incubation period of experimental allergic encephalomyelitis (EAE) delayed the onset of clinical signs. EN3638 was effective in both ordinary and hyperacute forms of EAE. Doses of 50, 100, or 150 mg/kg daily, 250 mg/kg three times a week, or 400 mg/kg twice a week suppressed both clinical and histologic evidence of EAE during the course of therapy (as long as 4 weeks) and for 8 or more days thereafter. Clinical EAE developed after a full incubation period after discontinuance of EN3638, probably due to the persisting depot of antigen in oil. When EAE was produced without an oily depot, a single dose suppressed the disease for at least 5 weeks in some rats. EN3638 was effective when given only in the second half of the incubation period but not when given at the time that EAE lesions and signs develop. Passive transfer experiments suggested that the drug prevented and even reversed sensitization to neural antigens. It had only slight effect on fully sensitized lymphoid cells or on the recruitment of nonimmune inflammatory cells in the nervous system, and it was not acting as a source of salicylate or as an adrenocortical stimulator.


Transplantation in minature swine. IV. Chemical characterization of MSLA and Ia-like antigens. Immunochemical analyses of radioactively labeled lymphocyte antigens from miniature swine of three different homozygous major histocompatibility (MHC) types, AA, CC, and DD, have been performed. Anti-MHC sera were incubated with lentil lectin purified Nonidet P-40 swine lymphocyte extracts. Antigen-antibody complexes were then precipitated with protein A bearing staphylococci, eluted, and electrophoresed on sodium dodecyl sulfate polyacrylamide gels. Analysis of antigens from AA or DD cells revealed peaks of 42,000, 31,000, 25,000, and 11,000 dalton m.w. Platelet absorption of the anti-MHC sera yielded antibodies that only precipitated the intermediate m.w. molecules and lysed a subpopulation of swine peripheral blood lymphocytes, suggesting that these molecules were the miniature swine analogues of murine Ia antigens. Antibodies eluted from platelets lysed all lymphocyte populations and precipitated only the 42,000 and 11,000 dalton peaks, indicating that these molecules represent the analogue of murine H-2 histocompatibility antigens, containing a heavy chain and putative swine beta2-microglobulin.


Immunoregulatory function of specific IgG. I. Results in nonatopic subjects. Nonatopic subjects immunized with short ragweed developed both reaginic IgE and blocking IgG antibodies to the antigen. Administration of 250 microgram-specific ragweed IgG antibodies 1 week before, simultaneously, or up to 2 weeks after start of immunization with ragweed extract abrogated the production of anti-ragweed reaginic antibodies which was measured by skin reactivity. Formation of specific ragweed IgG antibodies was unaffected by IgG treatment. These results indicate selective regulation of an immune response in humans by IgG.


Ontogeny of IgE-bearing lymphocytes in the rat. IgE-bearing lymphocytes were detected by immunofluorescence in the spleen of neonatal Hooded Lister strain rats within 24 hr after birth. The same cells were detected in the bone marrow as early as the 4th day after birth. Both fetal spleen and liver obtained 1 day before birth contained IgM-bearing cells but no detectable IgE-bearing cells. The proportion of IgE-bearing cells in the spleen and bone marrow increased during the neonatal period and reached an adult level within 3 to 4 weeks after birth. In adult Hooded Lister rats, IgE-bearing cells were 3 to 6% of total spleen cells and 1.5 to 2.2% of bone marrow cells. Most of the IgE-bearing cells from bone marrow cells. Most of the IgE-bearing cells from both newborn and adult animals carried IgM determinants on their surface. Capping experiments showed that epsilon chain determinants and mu chain determinants belonged to separate molecules. IgG2a-bearing lymphocytes were detected in the neonatal spleen as early as the 4th day after birth, but a significant number of these cells was not detected in the bone marrow until the 4th week. In newborn spleen the percentage of IgE-IgM double bearing cells was higher than that of IgG2a-bearing cells.


A cytotoxic proteinase isolated from human lymphocytes. A proteinase active at physiologic pH was isolated from unstimulated human peripheral blood lymphocytes with gel filtration and affinity chromatography. The proteinase with a molecular mass of approximately 30,000 daltons was completely inhibited by diisopropylfluorophosphate (DFP) and soybean trypsin inhibitor (STI). Incubation of the lymphocyte enzyme with 3H-proline labeled T24 human bladder carcinoma cells resulted in significant cytoxicity of the target cells. Cytotoxicity was only observed with much higher concentrations of trypsin. Similar results were obtained with a 51Cr release assay. This investigation demonstrates that unstimulated human peripheral blood lymphocytes contain a cytotoxic proteinase capable of killing pre-labeled target cells. The proteinase may be involved in lymphocyte-mediated cytotoxicity.


Labeling characteristics and separation of Ia antigen subunits. Experiments with biosynthetic incorporation of 3H-amino acids into murine and guinea pig Ia antigens have indicated that these antigens consist of two polypeptide chains of 33,000 and 25,000 daltons, respectively, occasionally linked by disulfide bonds into a 58,000 dalton molecule. In contrast, studies with lactoperoxidase-catalyzed radioiodination have indicated that these Ia antigens consist of only a single chain of 25,000 daltons. We therefore undertook a study to explore the basis of these discrepant results. Since 3H-tyrosine labeled both chains well, the lack of tyrosine residues in the 33,000 dalton chain could not be the explanation for the lack of radioiodination. However, by partially purifying the Ia antigen preparation with Lens culinaris (lentil) lectin affinity chromatography before immunoprecipitation and by increasing the resolution of analysis by using discontinuous-SDS polyacrylamide gel electrophoresis, it was possible to show that the 33,000 dalton chain was in fact radioiodinated, though still poorly so relative to the 25,000 dalton chain, and that a radioiodinated 58,000 dalton molecule could be detected. These experiments suggest that the 25,000 dalton chain is more exposed to the external cellular environment, and thus more readily iodinated by lactoperoxidase. In addition, the studies indicate that the choice of labeling method, purification procedures, and analytical methods must be taken into account when interpreting experimental results.


PHA-induced cytotoxicity of human lymphocytes against adherent hela cells. The conditions for a phytohaemagglutinin(PHA)-induced cytotoxicity test of human peripheral blood lymphocytes were investigated. [3H]thymidine prelabelled HeLa cells were used as target cells. Stimulation with 10 microliter PHA/ml during 24 h gave the best measure of lymphocyte cytotoxic capacity. Supernatants of PHA-activated lymphocytes showed no cytotoxicity against adherent HeLa cells. Mitomycin treatment did not influence cytotoxic capacity. Removal of phagocytizing mononuclear cells reduced spontaneous cytotoxicity, but increased PHA-induced cytotoxicity. Adherent cells showed high spontaneous cytotoxicity, with little increase on addition of PHA. The method was evaluated for clinical applicability by testing mononuclear cells from 19 normal subjects and purified lymphocytes from 15 normal subjects. Purified lymphocytes showed a higher PHA-induced cytotoxicity with a smaller variation and greater ratio dependent increase in cytotoxicity than unseparated mononuclear cells. Results with fresh purified lymphocytes were reproducible.


Quantitation of proteins by densitometric scanning of immunoelectrophoretic precipitates. Densitometric scanning of stained immunoelectrophoretic precipitates of nine human serum proteins showed that the optical density of the precipitates is approximately proportional to the molar concentration of antigen in the sample. Deviations from this correlation were noted for the macroglobulins (mol. wt. greater than 15 x 10(4)). The resolving capacity of the line immunoelectrophoretic procedure permits densitometric valuations of composite patterns.


A simple and reproducible method to evaluate granulocyte adherence. A simple method was devised to measure granulocyte adherence in whole blood. Columns of glass beads (4.5 mm diameter) in disposable plastic syringes were used. The assay showed great reproducibility when done in triplicate, the day to day variations in a given individual being minimal. Previous incubation of the blood with different ethanol concentrations diminished granulocyte adherence. The assay is easy to perform and does not require special equipment.


Immunoradiometric assay of salivary anti-c3 antibodies. By an immunoradiometric assay IgA and IgG anti-C3 antibodies were found in adult parotid salivas. The binding of the IgA antibodies to complement coated red cells could be reversed by washing in buffer containing 0.01 M EDTA but IgG antibodies were unaffected. The binding of IgA antibodies was inhibited by small quantities of purified C3. This assay may prove useful in the detection of anti-C3 antibodies in other body fluids.


Removal of unbound sodium dodecyl sulfate (SDS) from proteins in solution by electrophoresis through triton x-100-agarose. Residual sodium dodecyl sulfate (SDS) introduces artifacts into immuno- and counterimmunoelectrophoretic analysis of proteins which have been eluted from preparative SDS-polyacrylamide gels. Unbound SDS can be removed by electrophoretic passage of eluted solutions through a barrier of Triton X-100 in agarose in which the anionic and non-ionic detergents interact to form micelles.


An indirect antibody assay using haptenated antigen and 125i-labelled anti-hapten antibody. Hapten (trinitrophenyl) was coupled to antigen (ovalbumin). The haptenated antigen was bound by anti-ovalbumin antibody and binding was quantitated with 125I-labelled anti-hapten antibodies. Thus, with a single radioactive reagent antibodies against a variety of antigens can be detected, whilst the problems inherent in a labelled antiglobulin binding test are avoided. In the ovalbumin system, the haptenated antigen binding test proved to be approximately 20 times as sensitive as the iodinated ovalbumin binding test.


Therapy of psoriasis by tar photosensitization. For the first time since Goeckerman suggested the therapeutic potential of tar photosensitization of psoriatic skin, this mechanism has been shown to the effective in treating generalized psoriasis vulgaris. Long treatment times, need for special high-intensity sources, the presence of skin pain, and absence of information about long-term effects makes this treatment impractical at present.


Trichochromes in the urine of melanoma patients. The urine of patients with melanoma metastases and increased urinary excretion of 5-S-cysteinyldopa was examined for trichochromes. Five of 16 patients showed urinary excretion of trichochromes B and C. None excreted trichochromes E or F. All patients showing trichochrome excretion had very large amounts of cysteinyldopa in their urine.


Sources of serum [14C]-octanoate in cirrhosis of the liver and hepatic encephalopathy. Serum octanoate levels of patients with liver cirrhosis and hepatic encephalopathy have been shown to be three to 15 times higher than those of controls. Assays for octanoate have been modified to permit isolation of pure octanoate after GLC. Patients with these conditions were given intravenously differently labeled [14C]-palmitates; serum [14C]-octanoate was isolated in each case and shown by mass spectrometry to be authentic octanoate. [1-14C]-oleate and [1-14C]-stereate were also shown to serve as precursors of serum [14C]-octanoate. When differently labeled palmitates (1-[14C]; omega [14C]; and [14C]-uniformly labeled) were used, different yields of serum [14C]-octanoate were recovered. Octanoate samples were chemically degraded to yield individual carbons or groups of carbons. In this manner it was possible to determine the percentage distribution of the [14C] label within the octanoate carbon chain. The data obtained from these studies suggest that 60% to 80% of the serum octanoate was obtained from the incomplete beta-oxidation of long-chain fatty acids and that 20% to 40% of the octanoate may have been formed de novo.


Host metabolic alterations during Venezuelan equine encephalitis in the rat. Although an effective vaccine exists to protect against VEE, not all persons who may be exposed to this disease are likely to be vaccinated. The disease most often presents as a short febrile illness but the convalescence period may be protracted, and death due to encephalitis does occur in a small percentage of those infected. Knowledge of the metabolic alterations which occur during VEE may materially aid in its treatment. Use of the V-198 strain of VEE in the rat produces a uniform model in which to study metabolic alterations. Changes that occur early in the disease include viremia, neutrophilia, a decrease in plasma zinc and transferrin, and increased amino acid uptake into liver. Plasma zinc depression persists into the later stage of the disease, but to a lesser degree. Increases in plasma copper and seromucoid occur late in the disease, concurrent with the development of pronounced encephalitis. Hypoalbuminemia and decreased ketonemia occur during both the early and late stages of the disease. Taken together, these metabolic alterations appear to chronicle the development of VEE in the rat. If these metabolic alterations can be linked to specific pathogenic processes, they may be useful as prognostic indicators, in formulating supportive therapy, and as monitors of potential antiviral therapy.


Myocardial damage after repetitive direct current shock in the dog: correlation between left ventricular end-diastolic pressure and extent of myocardial necrosis. Acute myocardial necrosis was produced in 27 anesthetized dogs by repetitive DC 75 joule shock delivered with one electrode in the left ventricular cavity and the other on the left chest wall. A total of 1 shock/kg body weight delivered at 10 sec intervals resulted in discrete anterior wall necrosis of 7% to 31% (mean, 17.6%) of the mass of left ventricular myocardium. After some transient bradycardia, normal sinus rhythm was restored. Depression of left ventricular function 15 min after shock (rise in LVEDP from 4.0 +/- 1.5 to 17 +/- 2 mm Hg and fall in cardiac output from 2.29 +/- 0.24 to 1.82 +/- 0.12 L/min) recovered only slightly during the ensuing 2 hr. A significant correlation (r=0.85) was observed between the LVEDP at 2 hr after shock and the extent of necrosis determined histochemically and histologically at the time of sacrifice 3 hr after shock. Thus, in this form of acute myocardial damage, pump dysfunction is closely related to the area of necrosis.


Studies on platelet plasma membranes. III. Membrane glycoprotein loss from circulating platelets in rabbits: inhibition by aspirin-dipyridamole and acceleration by thrombin. DD125ISA, which binds to platelet surface glycoproteins, is lost more rapidly from double-labeled circulating rabbit platelets than is 51Cr, a label of platelet cytoplasm. Treatment of rabbits with aspirin and dipyridamole to diminish platelet function did not affect 51Cr survival but inhibited DD125ISA loss so that it disappeared from the circulation at the same rate as 51Cr . Intravenous thrombin infusion increased DD125ISA loss relative to 51Cr loss. Therefore surface glycoprotein loss was prevented by agents which inhibit platelet function and was accelerated by intravascular coagulation. These observations support the hypothesis that platelet surface glycoprotein loss is a continuous process in the normal circulation which may occur during reversible contact interactions in the process of hemostasis and thrombosis.


Membrane polypeptide aggregates in glucose 6-phosphate dehydrogenase-deficient and in vitro aged red blood cells. RBC membrane polypeptide aggregates have been quantitated by PAGE SDS and by gel filtration. Aggregates were absent in fresh RBC's from normal controls, but aggregates with MW 4.4 X 10(5) and greater than 50 X 10(6) increased progressively as GSH levels fell in RBC's incubated in PBS without added glucose or calcium. Aggregates of both MW ranges were also present in fresh RBC's from a patient with compensated congenital nonspherocytic hemolysis associated with a mutant RBC G-6-PD, Long Prairie. Since the aggregates were dissociable by treatment with mercaptoethanol or dithiothreitol, they are probably cross-linked by intermolecular disulfide bonds. Membranes containing these aggregates may represent an early and sensitive indicator of oxidative damage to red cells.


A new model for health effects of air pollutants: evidence for synergistic effects of mixtures of ozone and sulfuric acid aerosols on rat lungs. Chronic respiratory disease-free rats were exposed to relatively low levels of ozone (0.4 to 0.5 ppm) and H2SO4 aerosols (11 to 3,000 microgram/m3) and to mixtures of these pollutants. We independently evaluated exposure effects on conducting airway metabolism as rate of secretion of mucus glycoproteins by tracheal explants and on lung homogenates (predominantly lung parenchyma) by various chemical assays. True synergism was observed in that the response to the mixture of gases exceeded the sum of effects observed with the same concentration of either gas alone. Wet to dry weight ratios; DNA, protein, and RNA content; and the activities various lysosomal hydrolases in the lung homogenate all increased upon exposure to O3-H2-SO4 mixtures concomitant with observed increases in the rate of secretion of mucus glycoproteins by tracheal explants from the same rats. Preliminary experiments suggest that all of these effects are reversible when rats are allowed to recover after exposure. We conclude that the lack of toxicity noted upon exposure of experimental animals to individual pollutant gases at near-ambient levels should be interpreted with caution, since there is now epidemiological, physiological, and biochemical evidence that mixtures of pollutant gases may show synergistic effects.


Elevation of platelet factor four in acute myocardial infarction: measurement by radioimmunoassay. A radioimmunoassay has been developed for the measurement of PF-4--a chemically well-defined heparin-neutralizing molecule. PF-4 was iodinated, repurified by affinity chromatography on heparin-Sepharose, and incubated with rabbit antiserum and a source of unlabeled antigen. Following incubation at 4 degrees C for 24 hr, bound PF-4 was precipitated with 2.2M ammonium sulfate. The assay, which could detect 25 pg of purified PF-4, was unaffected by the presence of plasma containing up to 50 U/ml heparin. The plasma concentration of PF-4 in 30 normal subjects was 16 +/- 4 ng/ml. This level was increased in patients with pulmonary emboli, prosthetic cardiac valves, and severe cardiorespiratory failure. In addition, 21 of 50 patients admitted to the hospital with acute chest pain who had sustained a myocardial infarct had a mean level of 95 ng/ml. In contrast, the mean level in 21 patients with chest pain but without evidence of infarction was 29 ng/ml. PF-4 remained elevated for at least 1 week after infarction in six of the eight patients studied and then returned to within the normal range. The data suggest that radioimmunoassay of PF-4 may be a useful test to measure activation of the coagulation system and an aid to the diagnosis and treatment of patients with thromboembolic disorders.


Bile secretion and liver cell heterogeneity in the rat. The contribution of hepatocytes of different acinar zones to bile salt transport and to the secretion of the BSNDF was studied in the rat. Changes in the removal of 14C-taurocholate from blood, in the biliary secretion of taurocholate, and in canalicular flow were determined after damage of the periportal (acinar zone 1) or centrilobular (acinar zone 3) areas by allyl alcohol or bromobenzene, respectively. The extent of cell necrosis was quantitated by light microscopy, and the quality of the intracellular damage was assessed by electron microscopy. After either periportal or centrilobular damage, surviving cells responded to an intravenous infusion of taurocholate by secreting bile salts into bile at a rate similar to controls. However, following the administration of 14C-taurocholate at high concentrations and as a single bolus, the rate of removal of this isotope from blood was slower than in controls. Both experiments suggested that periportal and centrilobular hepatocytes had the capability for bile salt transport. Consequently, since the concentration of bile salts in sinusoidal blood at each zone determines the relative contribution of hepatocytes to bile salt transport, periportal cells probably transport the largest amount of bile salts reaching the acinus. Canalicular bile flow, on the other hand, decreased following centrilobular cell damage, and this was associated with a high concentration of bile salts in bile. This suggested that at bile salt loads near physiological concentrations, the predominant contribution of centrilobular hepatocytes is to the secretion of the BSNDF.


A comparison of procedures to determine free fatty acids in rat heart. The level of free fatty acids in intact tissues has been found to be low but is known to rise in proportion to the extent of autolysis. Therefore, the high levels of free fatty acid reported in the cardiac lipids of rats fed rapeseed oil were reinvestigated using two different procedures for homogenization. Quick freezing and pulverization at dry ice temperature followed by lipid extraction was found to give lower values of free fatty acids (200 microgram/g of wet heart tissue) than the more commonly used technique of employing rotating blade-type homogenizers (greater than 1700 microgram/g of wet heart tissue). The amount of diglycerides was found to be 3 times greater when the latter method was used. The high levels of free fatty acid and diglyceride suggest that extensive autolysis occurs during homogenization with a rotating blade-type homogenizer. Freezing and pulverization at dry ice temperature is therefore recommended for determining intact lipid classes in rat heart.


Rapid determination of the molecular weight distribution of total cellular fatty acids using chemical ionization mass spectrometry. A new method for the qualitative and quantitative determination of the molecular weight distribution of total cellular fatty acids is described. The method includes a simple extraction-saponification followed by chemical ionization-mass spectrometric analysis of the saponifiable matter. This technique requires small quantities of cell material which, combined with the rapidity and precision of the analysis, makes it attractive to the biologist interested in changes in the fatty acid composition of growing cells. As an example, an application of this method to the fatty acid determination of marine diatoms at different growth stages is presented.


Measurement and subcellular distribution of choloyl-CoA synthetase and bile acid-CoA:amino acid N-acyltransferase activities in rat liver. An improved method for assaying choloyl-CoA synthetase activity (E.C. 6.2.1.7) and two methods for specific measurement of bile acid-CoA:amino acid N-acyltransferase activity (E.C. 2.3.1) are described. The methods are shown to be reproducible, linear with respect to time and enzyme protein, and result in estimates of enzymic activity that conform to the theoretical stoichiometry of the individual reactions. Utilizing these methods, the subcellular distribution of the rat liver enzymic activity catalyzing the formation of glycine and taurine conjugates of bile acids is shown. Choloyl-CoA synthetase is associated with the microsomal membranes and bile acid-CoA:amino acid N-acyltransferase activity with the postmicrosomal supernatant. No significant amino acid N-acyltransferase activity is present in the lysosome fraction. These studies provide methods that will permit further study of the individual enzymic reactions involved in the intrahepatic conjugation of bile acids with amino acids.


The participation of ethyl 4-benzyloxybenzoate (BRL 10894) and other aryl-substituted acids in glycerolipid metabolism. Investigation into the mechanism of action of BRL 10894 (ethyl 4-benzyloxybenzoate), a compound possessing hypolipidemic activity in the rat, disclosed participation in glycerolipid metabolism. In the presence of BRL 10894, an abnormal metabolite was synthesized in vitro using liver slices or rings of small intestine with glycerol, palmitate, or monoolein as substrate, and using adipose tissue with pyruvate as substrate. Esters related chemically to BRL 10894 and other pharmacologically active acids (e.g., ibuprofen) also produced abnormal metabolites in vitro. With BRL 10894 in the diet, a similar metabolite was produced in vivo in rats and accumulated in adipose tissue. Chemical characterization of the material synthesized in vivo showed that the metabolite was a triglyceride in which one fatty acid moiety was substituted by the acid of BRL 10894. Additional proof of this structure was obtained by comparison with reference material synthesized in our laboratories. The study of the initimate involvement of exogenous acids in glycerolipid turnover is of value in the characterization of pharmacologically important acids and may be of use in achieving a greater understanding of certain aspects of lipid metabolism.


Separation of the natural retinoids by high-pressure liquid chromatography. A reverse phase high-pressure liquid chromatography system for rapid separation of various retinoids (vitamin A and its analogs) with little or no degradation is described. This method permits detection of as little as 22 pmol of retinoic acid. The procedure has been applied to the study of retinoic acid metabolism in vitamin A-deficient hamsters.


Ehrlich ascites tumor cell surface membranes: an abnormality in ether lipid content. Most mammalian neoplasms have a defect in ether lipid content manifested by the presence of abnormally large quantities of 0-alkyl glyceryl ethers, in contrast to normal tissues in which the alk-1-enyl structure predominates. These lipids are for the most part structural. The manner in which tumor cell plasma membranes differ from normal may be important, and it has been hitherto unclear whether or not the 0-alkyl lipid abnormality of neoplasms includes the plasma membrane. The present investigation reveals that 0-alkyl lipids are present in the membranes of Ehrlich ascites tumor cells isolated by several different methods. The amount of 0-alkyl lipid, on a weight basis, represents 1-3 percent of the total phospholipids and 1-4 percent of the total aliphatic lipid. These quantities are the same as or greater than the amount of 0-alkyl lipid found in microsomes, mitochondria, and whole cell homogenate. As is generally the case for intact neoplastic tissues, the quantity of 0-alkyl lipids of Ehrlich ascites tumor plasma membrane is greater than the amount of alk-1-enyl lipids.


Evaluation of an isotope ratio method for measurement of cholesterol absorption in man. Recently an isotope ratio method (IRM) was developed for measuring cholesterol absorption in rats by analysis of radioactivity in peripheral blood (Zilversmit, D. B. 1972. Proc. Soc. Exp. Biol. Med. 140: 862-865). To validate it in man we have compared cholesterol absorption by a fecal radioactivity method (FRM) with that simultaneously measured by IRM in 14 patients (15 experiments) hospitalized on a metabolic ward. Cholesterol absorption by FRM was assayed as fecal recovery of orally administered [(14)C]cholesterol, after correction with markers for fecal flow (chromic oxide) and cholesterol degradation (beta-sitosterol). Simultaneously, [(3)H]cholesterol was administered intravenously, and the dose-normalized ratio of [(14)C]- to [(3)H]cholesterol was repeatedly assayed in plasma. After 72 hours the ratio became constant in each patient and remained so for as long as 63 weeks (five additional outpatient studies). In three patients the fecal data were unsatisfactory because of poor recoveries of chromic oxide and radioactive cholesterol. In the remaining 11 patients (12 experiments) the mean cholesterol absorption by IRM was 42.1% (range 15.7-62.9%) and by FRM 36.6% (range 13.8-58.8%). There was good to excellent agreement between the two methods in the same patient, except in one experiment. Statistical analysis of these 12 comparisons by estimating confidence intervals showed that we can be 95% confident that the two absorption methods will produce results within 5 percentage points, and 99% confident that the differences are less than 7 percentage points. Although we conclude that IRM affords results that are concordant with those obtainable by earlier validated methods, we urge that its suitability for outpatient studies be further examined in more extensive trials.


Comparison of cholesterol turnover by sterol balance and input-output analysis, and a shortened way to estimate total exchangeable mass of cholesterol by the combination of the two methods. Daily turnover of cholesterol obtained by the balance method was compared to daily input rates calculated by input-output analysis in 43 experiments. The mean value of input rates for kinetic data of 10.1-16.4 weeks' duration (14 experiments) was 1.05 g/day vs. the chemical turnover of 0.94 g/day (difference 10.9 percent). For decay curves of 4.8-9.9 weeks' duration (29 experiments) the mean results were 1.67 g/day vs. 1.31 g/day, respectively (difference 20.1 percent). A combination of the balance method with input-output analysis is proposed to estimate the size of M (minimum value of the total exchangeable mass of cholesterol) in short-term experiments. Using this method, the analysis of curves of 10-12 weeks' duration showed a mean difference of 7.5 percent with the analysis of curves of 50-66 weeks' duration  in 17 patients. However, because of considerable variations  that can occur in individual cases, it is urged that a standard correction factor not be used, either in estimating turnover data or M from 10-12 weeks' kinetic data; rather, the proposed combined method will alert the investigator to the occurrence of discrepant results.


The sick sinus syndrome. A study of 50 cases. The long term prognosis was studied in 50 patients treated for the sick sinus syndrome with pacemaker insertion. The mean age of the patients was 71 years. There were 31 females and 19 males in the series. Nine patients (18%) died during the average follow-up period of 19 months. Dizzy and syncopal episodes were abolished in most patients with pacemaker therapy. However only two of the nine patients in congestive heart failure improved with the pacemaker. Thus the long term prognosis of patients with the sick sinus syndrome is poor despite pacemaker therapy. This is particularly true for the patient in chronic congestive heart failure who does not respond to the pacemaker treatment.


The effect of hypoxia on the refractoriness of the canine ventricular muscle. The effect of hypoxia on the relationship between refractoriness and transmembrane action potential was studied in isolated canine papillary muscle preparations. Test stimuli were applied at variable intervals after every 10 to 15 driving stimuli, and action potentials were recorded through an intracellular microelectrode located near the stimulus site. During hypoxia of 30 to 90 min duration, induced by nitrogenization of the perfusate, action potential duration (APD) was tremendously decreased in association with decline in the amplitude and rising velocity. The resting potential was also reduced. Concurrently the effective refractory period (ERP) was decreased, but its decrement was smaller than that of the APD. The total refractory period (TRP) was, on the other hand, prolonged. In consequence, not only the TRP but the ERP as well fairly outlasted full repolarization as a result of the hypoxia. The duration of the relative refractory period (RRP) was increased during hypoxia as the result of the changes in ERP and TRP, and graded local responses were registered frequently in the early phase of RRP. These facts were thought to be related to the genesis of arrhythmias in the ischemic heart.


The electrical characteristics of some commercial ECG electrodes. The impedance and offset potential of six disposable and two non-disposable electrodes were measured on 80 subjects. A total of 160 measurements were made on skin prepared by wiping with alcohol or acetone. For 640 measurements the skin was prepared by lightly sanding. The sanding of the skin reduced the impedance by a factor of approximately 50 for males and 100 for females. The offset potential for sanded skin was reduced by approximately 2. The performance of the disposable electrodes showed no great practical difference when applied on sanded skin. The median impedance ranged from 1500 to 3250 ohms. The median offset potential ranged from 0.5 to 4 mV. It was shown that a small DC current of 100 nA applied to stainless steel electrodes could cause a polarization voltage of approximately 0.5 volts to appear in 25 min.


Factors affecting overdrive suppression of idioventricular pacemakers and associated potassium shifts. A characterization of the factors controlling overdrive suppression of idioventricular pacemakers was investigated in canine hearts with complete atrioventricular block perfused in vitro. The following results were obtained: 1) overdrive suppression increases as a function of driving rate in a sigmoidal fashion; 2) overdrive suppression is maximal after 3 min; 3) the pause is a function of spontaneous rate prior to overdrive; 4) overdrive causes an initial net K loss; 5) overdrive is followed by a transient net K grain; 6) increasing [K]o does not affect K loss; 7) net K loss with drive is less in pre-driven hearts; 8) net K uptake after overdrive is little affected by ventricular activity; 9) acetylcholine does not alter ventricular K balance; and 10) paired stimulation increases overdrive suppression and K loss whether or not each stimulus is followed by a contraction. The following conclusions are drawn. The factors controlling overdrive suppression include the spontaneous rate prior to drive, the rate, duration and pattern of drive, an increase in [K]o during the drive and a decrease in [K]o after drive, but not on acetylcholine-mediated inhibition.


Active cables for use with dry electrodes for electrocardiography. With the active cables described in this paper, it is possible to record the electrocardiogram with dry electrodes. Simultaneous recordings of the ECG from dry electrodes via the active cables and from conventional electrodes with electrode paste demonstrate that there is no discernible difference in the electrocardiographic waveforms.


Combined intra-Hisian block and A-V nodal bypass. A patient with first and second degree atrio-ventricular (A-V) block and left bundle branch block was shown on electrophysiological study to have an intra and infra-His bundle branch block. In addition, this patient also had an A-V nodal bypass tract. The intra-Hisian block was concealed on the resting His bundle electrogram and became evident only during atrial pacing. The A-V nodal bypass was masked on the surface electrocardiogram (ECG) by the associated A-V conduction defect. The clinical significance of A-V bypass and combined block below the A-V node is discussed. The diagnostic value of His bundle electrocardiography in a patient with complex electrophysiological abnormalities is stressed.


Alternating Wolff-Parkinson-White (preexcitation) pattern. An electrocardiogram is presented which shows sinus rhythm with alternating Wolff-Parkinson-White (preexcitation) pattern. The frequency of intermittent preexcitation and mechanisms for its production are discussed.


Intermittent concealed atrial conduction demonstrated through intracavitary leads. An intermittent vanishing of the P wave from a standard electrocardiogram (ECG) while normal atrial activity was recorded on intracavitary leads was observed in a 58 year old man. This intermittent concealed atrial conduction is discussed.


A note on the "Brody-effect".

A note on the "Brody-effect". The effect of a perfectly conducting sphere simulating the intracavitary blood mass on a dipole source located at the interface with the outer tissue (myocardium) is studied, utilizing image theory. The resulting enhancement factor is found to be a function of the field point location and is not a constant, as previously reported by Brody and by Rush and Nelson.


A new hazard in the use of an external demand pacemaker. Ventricular pacing by a Medtronic model 5880A external demand pacemaker was shown to be inhibited as long as the metal coverplate of the pacemaker was touched with bare hands. The asystolic periods were induced by a previously undescribed malfunction of the pacemaker, inherent in its structure. This phenomenon occurred when both patient and physician were isolated from any main operated instrument. It could be demonstrated that pacer inhibition was induced by capacitive coupled 50 Hz fields from the environment, activating the sensing mechanism through the metal coverplate. The plastic covered Medtronic model 5840 pacemaker does not have such undesirable characteristics.


The Rescorla-Wagner model: losses in associative strength in compound conditioned stimuli. This series of experiments demonstrated that compound conditioned stimuli (CSs) highly conditioned in isolation lose conditioned response strength when compound-CS-unconditioned stimulus (US) pairings are given. This loss in conditioned responding was a positive function of the number of compound-CS-US pairings and was greater for the more salient stimulus. Finally, if a previously neutral stimulus was compounded with two previously conditioned cues, the neutral stimulus could acquire conditioned inhibitory properties with only compound-CS-US pairings. These results provide support for some aspects of the Rescorla-Wagner model.


Semantic integration of verbal information into a visual memory. A total of 1,242 subjects, in five experiments plus a pilot study, saw a series of slides depicting a single auto-pedestrian accident. The purpose of these experiments was to investigate how information supplied after an event influences a witness's memory for that event. Subjects were exposed to either consistent, misleading, or irrelevant information after the accident event. Misleading information produced less accurate responding on both a yes-no and a two-alternative forced-choice recognition test. Further, misleading information had a larger impact if introduced just prior to a final test rather than immediately after the initial event. The effects of misleading information cannot be accounted for by a simple demand-characteristics explanation. Overall, the results suggest that information to which a witness is exposed after an event, whether that information is consistent or misleading, is integrated into the witness's memory of the event.


Asymmetric transfer of prototype information between vision and audition. Specific and nonspecific transfer of pattern class concept information between vision and audition was examined. In Experiment 1, subjects learned visually or auditorily to distinguish between two pattern classes that were either the same as or different from the test classes. All subjects were then tested on the auditory classification of 50 patterns. Specific intramodal and cross-modal transfer was noted; subjects trained visually and auditorily on the test classes were equivalent in performance and more accurate than untrained controls. In Experiment 2, the training of Experiment 1 was repeated, but subjects were tested visually. There was no evidence of auditory-to-visual transfer but some suggestion of nonspecific transfer within the visual modality. The asymmetry of transfer is discussed in terms of the modality into which patterns are most likely translated for the cross-modal tasks and in terms of the quality of prototype formation with visual versus a,ditory patterns.


Health team function: testing a method for improvement. Health-care teams are functioning in the delivery of primary care. For purposes of this paper, the health-care team is composed of a primary care physician or physicians working with other health-care providers to deliver primary care. This definition represents an organizational model of health-care teams. Organizational specialists have proposed "team development" processes for improving health team function. This paper reports the results of an initial experiment designed to analyze the results of such a process. A modification of the "health-team development" process was used with one of three comparable teams at a family practice residency. Pre and post-team development data were taken. The team that experienced the modified team development process showed significant differences in the gain scores, compared to the "control" teams. Discussion focuses on the role of organizational technology in health-care teams and avenues of further analysis are presented. The modified format for the team development process is also reported and discussed.


A survey of students who chose Family Practice residencies. This paper presents the results of questionnaires sent to medical students at Wayne State University who chose family practice residency programs. It discusses three main areas: (1) choice of family practice as a specialty, (2) choice of a particular family practice residency program, and (3) future plans. Role models, the student's family, student membership in the American Academy of Family Physicians, the student's hometown, and Family Practice Club meetings were all important factors in the decision to become a family physician. The current residents' opinions of their program, the residency director, the quality of the current residents, and the location of the program were rated as quite important in the choice of a particular residency program. Most residents served their residency in their home state. Economic factors and university affiliation were not felt to be influential in program choice. A typical student plans to pursue family practice in a group that employs physician's assistants or nurse practitioners. He/she would also like to practice in his/her home state in either a rural area or a small city. Very few students were interested in either solo practice or academic family medicine.


Consultation-referral among physicians: practice and process. Consultation-referral is a part of everyday family practice. Although the process is taken for granted, it is a complex phenomenon. Neither the practice nor the process always meet the expectations of the referring physician or the consultant, and the patient may be the worse because of this discrepany. Studies of the practice and the process support this view. A model of the process is elaborated which can be used for the teaching of medical students or residents and which the practicing physician may use to improve his/her consultation-referral practices.


A case report in a Rural Health Center.

A case report in a Rural Health Center. An experiment utilizing nurse practitioners in the delivery of health care in a rural Nebraska community is described. In spite of several reorganizations, over a 2 1/2-year period of study, the project failed in terms of patient utilization. Visit rates began at 300 per month and increased to a high of 825 until the community perceived that the nurse practitioner was interposed between themselves and the primary physician. Rates then dropped to 375 and the community withdrew from the project. Implications for rural health projects using ancillary personnel are discussed.


Heart murmurs in infants and children.

Heart murmurs in infants and children. A system is presented for evaluation of heart murmurs in infants and children. The system places emphasis on identification of functional murmurs, which the physician encounters so frequently in daily practice. A three-part approach is presented which includes: (1) evaluation of cardiovascular status, (2) assessment of the heart murmur, and (3) decision regarding the need for further evaluation. This approach relieves the physician of the necessity to remember the multiple details of the many congenital cardiac lesions, and requires only the knowledge of a few easily remembered details about functional murmurs. The system enables the physician to confidently distinguish organic and functional murmurs and to decide which children need further evaluation and referral to the pediatric cardiologist.


The outpatient use of digitalis: a chart audit. In order to establish the appropriateness of the use of digitalis, the charts of 337 patients with heart disease from the Family Health Center at the University of Maryland were reviewed. The results revealed that several patients were on digitalis for weak or borderline reasons or for poorly documented reasons. Although few attempts had been made to discontinue digitalis, a high perc:ntage of those patients who had discontinued digitalis did so without morbidity or mortality, and without having to have digitalis reinstituted. The necessity for continuous evaluation and reassessment of each patient's need for digitalis was clearly illustrated. Chart audit was also a significant means of self as well as group education, through dissemination of the information obtained. Ideally, chart audits will improve patient care, both immediately as a result of the audit and long term as a result of increased awareness of possible problems and pitfalls. Further study is needed to verify this latter premise.


Nutrition and its importance in dental health. Balanced and good nutrition is necessary for the growth, development, and maintenance of the dental and oral structures. Nutrition counseling is, therefore, of paramount importance. The physician who is aware of the factors that cause dental and oral disease will be in a position to intercept the progress of dental caries caused by an incorrect diet. This paper considers the significance of highly cariogenic foods, particularly sucrose, and the difficulties of removing it from the diet. A method of conducting a diet survey is presented. The importance of fluoridation is discussed, with elaboration of the advisable prescribing techniques for fluoride supplementation of the diet. Cooperation between physician and dentist is important in order to insure the prevention of dental disease.


Hypokalemic periodic paralysis with arrhythmia. A case report and review of literature. Hypokalemic paralysis and/or arrhythmia must be treated cautiously and replacement therapy given slowly. The differential diagnosis should include familial periodic paralysis, an autosomal dominant disorder, which may present as hypokalemia, normokalemia, or hyperkalemia.


The schizophrenias: medical diagnosis and treatment by the family physician. About one percent of the population will develop schizophrenic symptoms sometime during their life. Etiologies are poorly understood and the course is highly variable. The differential diagnosis and medical treatment of the schizophrenias are discussed. Neuroleptic drugs are the most effective single treatment, for they allow most patients to be treated on an ambulatory basis, under the care of community physicians. Adverse effects of neuroleptic agents are common and often subjectively annoying. They may be prevented or minimized by agent selection, dosage schedules, or contra-active treatment.


Incest and the family physician.

Incest and the family physician. This paper is a review of incest from epidemiologic, familial, and individual points of view. The incest taboo has characterized almost every culture and society throughout the ages. Respect for the incest barrier is a cultural demand made by society and is not a physiological or biological imperative. Overt incest occurs in a dysfunctional family through tension-reducing "acting out." The family physician is in a unique position to observe and understand the family dynamics which both help maintain defenses against the incestuous wishes as well as, in some families, contribute to the practice of incest. For 2,000 years physicians have taken the Hippocratic oath, with its explicit love relationship clause, as a reminder of their ethical responsibilities towards their patients. Examples of para-incestuous relationships between vulnerable individuals and authoritative helping figures are cited. A psychodynamic rationale is offered as to why sexual relationships between patients and their family physicians are not therapeutically beneficial. Clues for assessment and ten preventive measures are presented to enable physicians to monitor themselves and the families in their practice.


Voltage-sensitive potassium channels in Limulus ventral photoreceptors. The steady-state slope conductance of Limulus ventral photoreceptors increases markedly when the membrane is depolarized from rest. The ionic basis of this rectification has been examined with a voltage-clamp technique. Tail currents that occur when membrane potential is repolarized after having been depolarized have been identified. The tail currents reverse direction at a voltage that becomes more positive when Ko is increased. Rectification is reduced by extracellular 4-aminopyridine and by intracellular injection of tetra-ethyl-ammonium (TEA). These results indicate that the membrane rectification around resting potential is due primarily to voltage-sensitive K+ channels. The increase in gK caused by depolarization is not mediated by a voltage-dependent rise in in Cai++, since intracellular injection of Ca++ causes a decrease rather than an increase in slope conductance. TEA can be used to examine the functional role of the K+ channels because it blocks them without substantially affecting the light-activated Na+ conductance. The effect of TEA on response-intensity curves shows that the K+ channels serve to compress the voltage range of receptor potentials.


Microspectrophotometric evidence for two photointerconvertible states of visual pigment in the barnacle lateral eye. Microspectrophotometrically derived difference spectra from the barnacles Balanus amphitrite and B. eburneus show that a blue illumination after an orange illumination causes a decrease in absorption in the blue region and an increase in absorption in the green-yellow region, with an isosbestic point around 535 nm. Orange-following-blue illumination causes the reverse changes. The dark time between the adapting and measuring lights has no influence on the data. The results confirm previously reported ERP measurements which indicate that the barnacle visual pigment has two photointerconvertible dark-stable states. If one assumes a Dartnall nomogram shape for the two absorption spectra, a best fit to the observed difference spectra is obtained with nomograms peaking at 492 nm and 532 nm, with a peak absorbance ratio around 1.6:1. These two nomograms fit very well the ERP action spectra of metarhodopsin and rhodopsin, respectively, thus indicating that the ERP is a reliable measure of visual-pigment changes in the barnacle. The existence of a photostable blue pigment is demonstrated in B. eburneus and in some of B. amphitrite receptors, and the possible influence of this photostable pigment on the various action spectra measured in the barnacle is discussed.


Diffusion within egg lecithin bilayers resembles that within soft polymers. An analysis is presented of how the permeability coefficient/octanol:water partition coefficient ratio for 33 different chemical substances crossing egg lecithin bilayers depends on the molecular volume of the substances. From this analysis we conclude that bilayers made from egg lecithin behave as soft polymers in their discrimination between permeants of different sizes and shapes.


DNA sequence homology estimation by combinatorial analysis of endonuclease restriction data. A combinatorial analysis of the products of DNA cleavage by restriction endonucleases permits an estimation of the sequence homology between closely related linear DNAs. The main assumption to be made is that fragments of identical length represent equivalent sections of the genomes. All patterns of common and varying restriction sites compatible with the results of the electrophoretic analysis of fragment sizes can be enumerated, each yielding an estimate of the proportion of sequences of restriction site length common to both DNAs. From this, sequence homology is derived by using a model of randomly distributed point mutations relating the two genomes. Possible limitations of the approach are discussed.


A method for assessing the size of a protein from its composition: a correction. A previous report in this Journal of a computer method for assessing the size of a protein from its amino acid composition, and its application to virus protein data, contained an error in the published arithmetical formula. Persons using the incorrect formula would not have obtained incorrect estimates of possible protein sizes, but would have obtained a more equivocal set of possible sizes.


The replication and titration of iridescent virus type 22 in Spodoptera frugiperda cells. A plaque assay for iridescent virus type 22 (from Simulium sp.) using Spodoptera frugiperda cells has been devised, and the kinetics of growth of the virus in this cell line have been determined. The virus particle/p.f.u. ratio was 75 +/- 8, and the p.f.u./TCID50 ratio was 0.56 +/- 0.11.


Quantification of influenza virus structural proteins using rocket immunoelectrophoresis. The major influenza A virus structural antigens, matrix protein, nucleoprotein, haemagglutinin and neuraminidase were measured rapidly and accurately using a rocket immunoelectrophoresis technique. Virus was disrupted with 1% (w/v) sodium sarcosyl and electrophoresed into agarose containing specific antiserum to the individual virus structural proteins in 0.05 M-barbitone buffer, pH 8.6, for 1 to 4 h. For haemagglutinin antigen assays statistical analysis indicated that the coefficient of variation within an immunoelectrophoresis plate was 8.0% for antigen concentrations in the range 15 to 40 microgram/ml protein. For haemagglutinin and matrix protein the method was sufficiently sensitive to measure concentrations of antigens as low as 1.5 and 2.0 microgram/ml respectively. By incorporation in the agarose of mixtures of antisera against specific antigens of the virus, haemagglutinin, matrix or nucleoprotein could be assayed simultaneously.


Further physicochemical characterization of Nodamura virus. Evidence that the divided genome occurs in a single component. Nodamura virus, a small non-enveloped RNA virus, contains two species of RNA sedimenting at 22S (RNA-1) and 15S (RNA-2), a single major polypeptide of mol. wt. 40 X 10(3) and two minor polypeptides, of mol. wt. 38 and 43 X 10(3). Evidence is presented that the two RNA species are in the same particle. Although extraction of the virus with SDS-phenol yields the two species of RNA as separate entities, gentle treatment of the virus with guanidine and low concentrations of SDS releases the RNA as a 27S component which contains both RNA-1 and RNA-2 together with a trace of protein. It seems likely that the two RNA species replicate separately because double stranded molecules corresponding to the single stranded RNA-1 and RNA-2 molecules were present in BHK cells infected with the virus.


Study of regional cerebral metabolism and blood flow relationships in man using the method of continuously inhaling oxygen-15 and oxygen-15 labelled carbon dioxide. A new technique for assessing regional oxygen use and blood flow has been applied to a wide range of neurological patients. The method couples the brain's high metabolic demand for oxygen with a shortlived radioactive form of this metabolite, namely oxygen-15 (half life: 2.1 min). This combination produces during the continuous inhalation of either molecular oxygen-15 or labelled carbon dioxide, steady state functional images of the brain which are relatively free of contribution from extracerebral tissues. These are complementary images in that they relate to regional oxygen uptake and blood flow and hence offer a direct insight to the regional demand-to-supply relationships within the brain in physiological and pathological conditions. In the clinical groups studied, metabolic and circulatory defects were observed and instances of cerebrovascular insufficiency and relative luxury perfusion were defined which hitherto have been deduced from indirect methods. The clinical acceptability of this non-invasive approach allowed us to study those categories of patients which normally do not warrant invasive examination.


Non-invasive regional study of chronic cerebrovascular disorders using the oxygen-15 inhalation technique. The regional cerebral metabolism-to-perfusion imbalance has been studied in the three main categories of cerebrovascular disorders in a chronic phase of the disease, using the non-invasive oxygen-15 inhalation technique. In patients presenting with a history of transient ischaemic attacks, regional defects in cerebral perfusion were greater than for the corresponding oxygen uptakes. Areas of relative ischaemia within which there was an enforced increase in the oxygen extraction ratio were highlighted. The reverse pattern was observed frequently in patients with brain infarcts arising from strokes, so indicating areas of relative luxury perfusion as is inferred from the reduction in the oxygen extraction ratio. In the multi-infarct dementia group of patients, there were parallel focal reductions in both flow and metabolism. The oxygen-15 inhalation technique is shown to be a unique tool in investigating cerebrovascular disorders because of its non-invasiveness and its ability to define regional metabolism-to-perfusion imbalance within the brain.