Systolic time intervals in induced atrial fibrillation in the dog: effects of ectopic ventricular activation. Electrocardiogram, atrial electrogram, phonocardiogram, aortic pressure, and left ventricular pressure were recorded during periods of induced atrial fibrillation in dogs anesthetized with a combination of morphine sulfate and pentobarbital sodium. Data were accumulated by selecting 50 cardiac cycles which terminated in ectopic ventricular electrical complexes, and comparing systolic time intervals (STI) following these beats with STI Following 50 normal ventricular complexes. Ectopic ventricular activation prolonged left ventricular pre-ejection period and external isovolumic contraction time, and reduced duration of left ventricular ejection time. These events resemble changes in STI observed following induction of atrial fibrillation from a sinus rhythm, but they are of significantly greater magnitude than the effects of atrial fibrillation alone.


Natural history of atrial septal defect of secundum type in the middle-aged. Medical versus surgical therapy. 10 middle-aged patients with atrial septal defect of the secundum type (ASD II) were referred to surgery, but for several noncardiological reasons the operation was not performed. 5 patients were reexamined after an interval from 6 1/2 to 15 years. During the follow-up period only relatively minor changes in pulmonary arteriolar resistance had occurred and all patients were still acceptable candidates for surgical treatment. The other 5 patients died after a period of time ranging from 2 weeks to 16 1/2 years from conditions directly or indirectly related to the cardiac malformation. During the same period of time, 84 ASD II patients underwent surgery with a mortality rate of 8.3% after 74 months, including 2 hospital deaths. These results suggest that middle-aged patients with ASD II without obstructive pulmonary hypertension should be operated on without delay, but that in a significant number of cases, long-term conservative treatment is not associated with an increase in pulmonary arteriolar resistance.


Electrocardiographic findings before and after surgery for atrial septal defect of the secundum type in middle-aged patients. Surgery for atrial septal defect of the secundum type was performed in 84 patients over 40 years of age. Electrocardiograms were studied preoperatively and at a follow-up visit 74 months (range 22-174 months) after surgery. Preoperatively, atrial fibrillation was observed in 13% of the patients, complete right bundle branch block in 30%, and a secondary R wave (R') in lead V1 in 72%. A significant correlation was found between the amplitudes of SV6 and R'V1 and the right ventricular systolic pressure, whereas no significant correlation could be demonstrated between the shunt ratio and any of the QRS parameters. After successful surgery, the mean QRS axis in the frontal plane shifted from +99 degrees to +47 degrees (p less than 0.01), and the following highly significant (p less than 0.001) changes were noticed: increase of the amplitude of SV1, shortening of the QRS duration in V1, increase of the ratio QR'/QRS V1, shortening of the duration of SV6, and diminution of the initial forces of the P wave in V1.


Lysosomal activation in mouse skeletal muscle induced by protamine in vitro. Incubation of mouse skeletal muscle in a physiological Ringer solution containing protamine (60 microgram/ml) at +37 degrees C for 1 h induced ultrastructural changes including proliferation of tubular profiles and vesicles at the I-band level close to the A-I junction, formation of numerous acid phosphatase positive lysosomes in the longitudinal sarcoplasmic reticulum and autophagic vacuolation starting at the level of the A-I junction. Biochemical determination of acid phosphatase in the incubated muscles showed that protamine caused an increase in acid phosphatase activity of about 25% compared to enzyme activities obtained from muscles incubated without protamine at +37 degrees C or with protamine at +4 degrees C. The morphological findings suggest that the vesicles arising adjacent to the A-I junction originate from transverse tubules. Such vesicles, designated as endocytic, may acquire acid phosphatase activity in the longitudinal SR ano be active in an autophagic process resulting in large vacuoles. A causal relationship between endocytosis and lysosomal activation is suggested.


A freeze-fracture study of tight junctions in the pars convoluta and pars recta of the renal proximal tubule. The morphology of tight junctions of the renal proximal tubule was studied comparing the pars convoluta and pars recta of rat, golden hamster, rabbit, cat, dog and tupaia. Though some interspecies variations were observed, the convoluted portions of the proximal tubules revealed quite uniformly very leaky tight junctions with mainly 1-2 strands. Along the whole proximal tubule of the rabbit kidney including the pars recta only minor differences of the zonulae occludentes were found. By contrast, the tight junctions of the pars recta in other species were much more elaborate, especially in cat and tupaia, having up to 6 strands and an overall depth of more than 150 nm. The implications of these findings are discussed with special regard to the functional differences between the pars convoluta and pars recta of the proximal tubule.


Increased metabolic activity of rabbit articular cartilage in vitro. The metabolic, histochemical and ultrastructural modifications induced in rabbit articular cartilage during in vitro incubation at 37 degrees C, for various periods (10 min to 18 h), using Krebs phosphate-glucose nutrient medium, were studied. It was found that after only 10 min of incubation, the chondrocytes increase their synthesis of matrix macromolecules for, at least, the next 6 h. This was suggested by: 1. Increased incorporation 35S-sulfate and 3H-glycine during the first 6 h of incubation. 2. An intensification of metachromasia, which also spread out into the superficial layer that is normally orthochromatic. Only the most superficial layer corresponding to one or two rows of the cells, retained its staining pattern throughout the incubation; 3. A rapidly acquired abundant rough endoplasmic reticulum, enlarged Golgi area and numerous newly synthesized proteoglycan molecules. This study poses fundamental questions about the mechanisms that regulate matrix synthesis by the chondrocytes.


The pattern of innervation of a polyneural muscle: axolotl iliotibialis. The pattern of innervation on individual iliotibialis muscle fibres from axolotl (Ambystoma mexicanum) has been investigated histologically and electrophysiologically. These polyneural fibres were found to be innervated on average at five end plate sites. The sites were distributed irregularly along each fibre. Average end plate length was found to be approximately 70 micrometer. Most end plates were separated by less than 1000 micrometer; 26% by less than 150 micrometer; the average separation was 516 micrometer. Advantage was taken of the dual innervation of the muscle to investigate the separation between synaptic terminals from different axons. Some individual fibres were found to be innervated by axons from two different spinal nerves. End plate sites on dually innervated fibres were located by ACh iontophoresis. 30% of such sites were found to be innervated by more than one axon terminal. The average separation of such sites was found to be 9 micrometer. Four different axons were found to innervate some individual muscle fibres. It is suggested that the unusual ability of axolotl muscle fibres to accept synaptic terminals from different axons at closely adjacent sites may be a major factor underlying selective reinnervation in this animal.


Accumulation of secretory granules in pituitary clonal cells derived from the epithelium of Rathke's pouch. 2A8 clonal cells derived from the epithelium of Rahtke's pouch of the fetal rat are essentially agranular when grown in vitro, in spite of their active secretion of hormones, i.e., ACTH, prolactin and growth hormone. These cells do not produce detectable amounts of thyrotrophic or gonadotrophic hormones in vitro. When the growth medium (Ham's F10) was supplemented with rat median eminence extract (MEE), L-thyroxin and fresh serum from hypophysectomized rats, some of the 2A8 cells accumulated and stored secretory granules which were characteristic of the cells of the intact pituitary gland. Typical thyrotrophic and gonadotrophic cells also became recognizable and all six anterior pituitary hormones were released into the culture medium. Growth of 2A8 cells in this modified culture medium resulted in an increased production of all hormones with increasing time in culture. These results indicate that the processes that lead to the accumulation of typical mature secretory granules which characterize the individual pituitary cell types are initiated or promoted by some unidentified factor or factors which are present in fresh rat serum. It is also apparent that fresh rat serum can promote the differentiation of gonadotrophs and thyrotrophs in vitro.


Moulting and morphogenesis of sensilla in a prostigmate mite (acari, actinotrichida, actinedida: caeculidae) I. Mechanoreceptive bristles. In the prostigmate mite Microcaeculus steineri delamarei moulting and morphogenesis of mechanoreceptive sensilla were studied by electron microscopy and compared to corresponding sensilla of other arthropods. Dendritic contact with the cuticular parts of old sensilla breaks down during apolysis. Two groups of cells are engaged in the formation of new sensilla: 1) several trichogen and two tormogen cells in a semicircular arrangement, and 2) two sheath cells surrounding the mechanoreceptive dendrites. Cells ensheathing the dendrites do not play any part in the formation of bristles. These observations differ from those on insect sensilla during moulting.


Prolactin, hypercalcemia and corpuscles of Stannius in seawater eels. In intact eels in sea water (SW), ovine prolactin (PRL) treatment induces hypercalcemia, but its mechanism of action, which is discussed, remains to be defined. Corpuscles of Stannius (CSt) are modified simultaneously: two cell categories then become evident. The first cell type (type 1) predominates; it has an oval shape and large granules, it shows a nuclear and nucleolar hypertrophy and a mitotic activity, and appears greatly stimulated by PRL; it may elaborate a hypocalcemic factor (hypocalcin) which would compensate for the PRL-induced hypercalcemia. A similar effect, although slightly less intense, is detected in hypophysectomized-PRL treated eels in SW. A second cell type (type 2), is more elongated, smaller in size, and has an oval nucleus and fine granules. Scarcely less active in SW, it is significantly stimulated by PRL despite an increased blood sodium and potassium level. This experiment does not help to clarify its function.


The microvascular pattern and perivascular linings of the area postrema. A combined freeze-etching and ultrathin section study. The microvasculature and perivascular linings of the area postrema (A.P.) were studied electron microscopically with the ultrathin section and freeze-etching techniques. Special attention was given to the intercellular contacts of the different cellular entities. Two types of microvascular segments were identified. The endothelium of these vascular segments reveals fenestrations and a high pinocytotic activity. There are no significant differences in the frequency and distribution of the endothelial "openings" between both types of capillaries. The endothelium of the blood vessels, however, is joined by different types of tight junctions. Focal tight junctions occur between pericytes and the endothelium, and between leptomeningeal cellular elements in the perivascular space. The cell membrane of the perivascular glia shows intramembrane particles which are either distributed at random or organized in the form of membrane-associated orthogonal particle complexes (MOPC, Dermietzel, 1974). The significance of these findings is discussed with respect to the modified blood-brain barrier mechanism in the A.P.


Sequestration of neuraminidase-treated erythrocytes. Studies on its topographic, morphologic and immunologic aspects. Scintigraphic experiments and radioactivity measurements of tissues have shown that the radioactivity of 51Cr-labelled and neuraminidase-treated rabbit erythrocytes is rapidly accumulated in liver and spleen. Sequestration of these erythrocytes by liver and spleen was demonstrated by light and electron microscopy of theses tissues after perfusion of the rabbits with solutions for tissue fixation. In liver the phagocytic activity of Kupffer cells was increased after injection of desialylated erythrocytes, while in spleen a significantly enhanced number of erythrocytes was found attached to the sinusoidal walls and in the reticulum of the red pulp. It was shown by scanning electron microscopy that neuraminidase-treatment did not influence the shape of erythrocytes. Desialylated and 51Cr-labelled erythrocytes from the cow are rapidly cleared from the blood-stream with a half-life time of about 3 h. It was shown in an in-vitro test that they adsorb to surviving slices from liver and spleen derived from the same animal. The amount of radioactivity adsorbed is appreciably enhanced in the presence of homologous serum when compared with buffer only. Human neuraminidase-treated erythrocytes are agglutinated in the direct and especially in the indirect Coombs-tests. The involvement of T-antigen in this phenomenon was largely excluded. The in vitro experiments and antibody consumption tests suggest that immunoglobulins (IgG) and complement from serum may be involved in recognition and sequestration of desialylated erythrocytes by macrophages in vivo.


Exocrine pancreas under experimental conditions. IV. Alterations of intercellular junctions between acinar cells following pancreatic duct ligation. Exocrine pancreatic tissue was investigated during various intervals after pancreatic duct ligation. Concomitant to the increase of the intraluminal pressure, alterations are found in the arrangement of the luminal membrane surface and the zonulae occludentes of the acinar cells. The zonulae occludentes exhibit a disarrangement of their strands. The number of strands diminishes and small interruptions as well as large discontinuities of the strands are observed in most regions of the acinar cells. Furthermore, gap junctions are found very infrequently between acinar cells. The ultrastructural alterations of the zonulae occludentes suggest a gradual adaptation to the increasing unilateral pressure. However, a leakage of the paracellular permeability barrier occurs which contributes to the known shunt between the compartments of the pancreatic juice and the interstitial space following pancreatic duct obstruction. The present investigation is a further example of alterations in the paracellular permeability and intercellular communication of epithelial cells under pathological conditions.


Control of the pars intermedia of the lizard, Anolis carolinensis. I. Ultrastructure of the intact neural lobe. The ultrastructure of the neural lobe of the lizard, Anolis carolinensis, was studied after fixation in a threefold aldehyde solution. The neural lobe appeared as narrow vertical diverticula separated from one another and from the pars intermedia by a continuous vascular septum. No nerves passed through this septum. The ependymal, fibrous and external layers were readily recognized. Peptidergic fibres were the main component of the fibrous layer. The peptidergic endings were in intimate contact with the ependymal cells, suggesting that the ependyma mediates the release of neural lobe peptides. The external layer contained ependymal end-feet and numerous aminergic terminals, ending directly on the perivascular basal lamina and/or on the ependymal end-feet. The functional aspects are discussed in terms of intermediate lobe control. The findings suggest that aminergic substances take part in the control of the intermedia, but do not exclude the involvement of peptide hormones.


The outer segments of photoreceptive pinealocytes in the pineal organ of the funa, Carassius gibelio langsdorfi. A scanning electron microscopic study. The form and size of the outer segments of photoreceptive pinealocytes in the pineal organ of the funa, Carassius gibelio langsdorfi, were observed with the scanning electron microscope. The height of the outer segments measures between 1 and 3 micrometer and the diameter varies widely from 1.5 to 8 micrometer. Various forms of outer segments, i.e. a slender type, a dome-like type, a cap-like type and a helical type, were demonstrated. The parallel-oriented filamentous processes of the inner segments have the same length as the outer segments and a diameter of approximately 100 nm; they are projections from the apical border of the inner segment and surround the cone-like outer segments. The processes make a right angle with the lamellar disks. The distance between two processes averages 100 nm. The lamellar disks of the outer segments are oriented at right angles to the modified cilium in the basal part, but the angle often changes in the peripheral part, where the lamellar disks are raised and become parallel to the cilium.


Gap junctional coupling between the JGA and the glomerular tuft. The juxtaglomerular apparatus (JGA) in the rabbit kidney was examined by transmission electron microscopy and by freeze fracturing. It was found, that the Goormaghtigh cells of the JGA are extensively coupled with the mesangial cells within the glomerular tuft by gap junctions. A broad band of gap junctions starting within the Goormaghtigh cells, traversing the transitional area at the root of the glomerular tuft and continuing along the mesangial cells has been revealed by freeze fracturing. No gap junctional connections to the macula densa cells have been found. In accordance with data from literature it may be stated that all smooth muscle derived cell groups at the vascular pole of the glomerulus (smooth muscle cells of the vas afferens and efferens, granular cells, Goormaghtigh cells, mesangial cells) are extensively coupled by gap junctions with each other. It is supposed that this cell system may act as a synchronized functional unit.


Ultrastructure and lipid content of the liver of the zebrafish, Brachydanio rerio, related to vitellogenin synthesis. The female zebrafish is capable of producing mature eggs on the fifth day of each reproductive cycle. During this five-day period the ultrastructure of hepatocytes undergoes several changes. The number of nuclear pores increases rapidly during spawning, followed by a proliferation of RER within 24 h. Two days after spawning, glycogen has disappeared and the liver contains large amounts of lipids. The lipid droplets are closely surrounded by elongated mitochondria. Golgi complexes are abundant, secreting dense bodies. Four days after spawning the hepatocytes tend to regain their pre-spawning appearance. It is suggested that the changes in the hepatocytes, which coincide with special phases of ovarian activity, are related to vitellogenin synthesis. Steroids, especially estradiol-17beta, may trigger this process in the liver.


An ultrastructural study of the larval integument of the midge, Chironomus riparius Meigen (diptera: chironomidae). The larval integument of the midge, Chironomus riparius Mg., is unusually thin although it conforms with the normal insect pattern. The cuticle of the post-cephalic segments is about 3 micrometer thick and overlies an epidermis which has an irregular basal plasma membrane resulting in spaces occurring between it and the basement membrane. The ventral tubuli have a similar epidermis but the cuticle is somewhat thinner. The anal papillae have the thinnest cuticular covering with a uniquely folded epicuticle of variable thickness, and their epidermis has the characteristics of a transporting epithelium. No evidence of pore canals could be found in the cuticle of any part except the head capsule which has a remarkably smooth epicuticle and a distinct layer which may represent the exocuticle. There are no spaces between the basement membrane and basal plasma membrane of the epidermis in the head. Ultrastructural evidence would suggest that gaseous exchange can occur across most of the post-cephalic integument.


The growth of follicles in the rat ovary under the influence of busulphan and endoxan. Busulphan and Endoxan inhibit the normal course of ovarian follicular growth. Older secondary as well as an antral follicles perish within a very short time. Growing follicles, which at the beginning of the experiment exhibited only one layer, remained intact and single-layered during the entire duration of the experiment. The oocytes, however, continue growing, and the cytoplasmic structures, which are characteristic of older growing follicles, develop in them as well as in the follicle cells. Even a theca formation develops. In some of the "growing" follicles which have remained single-layered, after 10 days of Busulphan administration, some liquor folliculi is produced and accumulates in a fissure-shaped "antrum" between the zona pellucida and the follicular epithelium.


The cells of the rat gastric groove and cardia. An ultrastructural and carbohydrate histochemical study, with special reference to the fibrillovesicular cells. The distal wall of the groove between the rat forestomach and glandular stomach is lined with a special type of columnar cells (CCGG) and with fibrillovesicular cells (FVC). The cardiac glands contain cardiac mucosa (CMC) and serous cells (CSC). The CCGG contain small mucous granules and special vesicles and tubules. The CMC are filled with large mucous granules and resemble mucous neck cells. The CSC are filled with large proteinaceous granules. The FVC are characterized by long microvilli, apical bundles of microfilaments and a complex "tubulovesicular system". The pattern of 3H-thymidine incorporation and the presence of immature and transitional forms indicate a possible origin of all the cell types concerned from a common undifferentiated precursor. The membranes of the tubulovesicular system of FVC as well as the apical cell membrane were reactive to Thiéry's carbohydrate stain. However, lanthanum tracing of the extracellular space and ultrastructural stereoscopy did not reveal a permanent continuity between both membrane systems. The absence of 3H-thymidine label showed that FVC were not proliferative. The structural characteristics of FVC do not account for a secretory, resorptive or receptive function. The special arrangement of microfilaments and the tubulovesicular system suggests an ability to fast changes in surface area.


Calcium and sulphur in neurosecretory granules and calcium in mitochondria as determined by electron microscope x-ray microanalysis. Sections of neurosecretory cells fixed in glutaraldehyde and osmium tetroxide were studied by means of an EMMA-4 analytical microscope. Secretory granules in neurosecretory cells of the corpus cardiacum and of the brain, both in the desert locust Schistocerca and in the blowfly Calliphora, as well as neurosecretory granules in posterior pituitaries of the frog Rana and of the albino rat all contain a high concentration of calcium. A distinct sulphur peak was also a constant feature. In neurosecretory cells of the corpus cardiacum of Schistocerca the chromatin contained a high concentration of calcium. The mitochondria also contained much calcium, but part of this disappeared during preparation except when fixative and wash contained calcium chloride. By block staining with uranyl acetate most calcium is displaced from the mitochondria, whereas most of the calcium remains in the neurosecretory granules. Since the calcium peaks in spectra from neurosecretory granules appear of similar size, regardless of variations in the preparative procedure, this calcium must be firmly bound. The possible role of the calcium bound to the neurosecretory substance is discussed. The presence of sulphur in insect neurosecretory granules indicated the presence of a protein besides the hormone, i.e., an insect neurophysin.


Localization of serotonin within tanycytes of the rat median eminence. Formaldehyde and glyoxylic acid histochemical methods were employed to examine monoamine fluorescence of the rat median eminence. Tanycytes of the median eminence contained a yellow histofluorescence which was verified with microspectrofluorometry as due to the presence of serotonin. Catecholamine-containing varicosities, arranged in linear profiles throughout the depth of the median eminence, were observed. These linear profiles appeared to follow the contours of serotonin-containing tanycytes. Organ-culture experiments supported the hypothesis that the serotonin associated with tanycytes is localized within the tanycytes and does not arise from an extrahypothalamic source of nerve terminals. These data provide evidence that a tanycytic catecholamine-indoleamine morphological juxtaposition occurs in a manner reminiscent of that of another circumventricular organ, the pineal.


The structure of the tips of mammalian respiratory cilia. The ciliary crown and the relationship of the ciliary crown to the underlying axoneme were studied by electron microscopy in cilia from hamster and rat trachea and bronchioles, and rabbit trachea. The ciliary crown is a cluster of 4 to 6 fibrils 35 nm long protruding beyond the plasma membrane at the tips of the cilia. The fibrils are well preserved after tannic acid-glutaraldehyde-osmium tetroxide fixation and have high contrast with a periodic density of 4.5 nm. They stain relatively weakly with phosphotungstic acid. The surface of the fibrils stains with ruthenium red. The microtubules of the axonemem end in a plate of electron dense amorphous material. A five layered disc occupies the space between the membrane and the amorphous plate at the tip of the axoneme. The plasma membrane can be dissolved with the detergent triton X-100 without loss of the ciliary crown. This indicates that the ciliary crown is composed of transmembranous filaments which are bound to the disc at the tip of the axoneme.


Ultrastructural changes in the fat body of adult female Aedes aegypti in relationship to vitellogenin synthesis. The ultrastructure of the fat body of Aedes aegypti was followed from emergence through a blood meal. Changes in the volume of protein granules and lipid droplets were also examined. The relationship of these events to the known endocrinology of vitellogenin synthesis in mosquitoes is discussed.


A note on the structure of synapses in the ventral nerve cord of the onychophoran Peripatoides leuckarti. The fine structure of synapses, their distribution and arrangement in the ventral nerve cord of Peripatoides leuckarti (phylum Onychophora) is described. The asymmetric synaptic junctions show a well developed synaptic cleft (300 A) and pre- and subsynaptic electron dense apposition. They frequently show an array of presynaptic projections and a subsynaptic cisterna of endoplasmic reticulum. The onychophoran synapses differ from those of annelids and insects.


An autoradiographic study of satellite cell differentiation into regenerating myotubes following transplantation of muscles in young rats. Satellite cells were traced autoradiographically during the regeneration of skeletal muscle in young Sprague-Dawley rats. Approximately 31% of the satellite cells in uninjured muscles appeared labelled after three injections of tritiated thymidine; none of the myonuclei were labelled in the same muscles. Four to six days after transplanting the radioactive muscles to non-radioactive littermates, regenerating myotube nuclei in the host appeared labelled. Thus, this study confirms that satellite cells in young rats can differentiate into multinucleated myotubes following muscle injury.


Electron microscopical microprobe analysis of freeze dried and unstained mineralized epiphyseal cartilage. Electron micrographs have been taken of unfixed, freeze dried, unstained epiphyseal cartilage. In the mineralized long septa round to elliptic clusters (up to 0.6 micron in diameter) consisting mainly of dots and needles could be observed. The clusters were surrounded by microareas with a low contrast consisting mainly of ribbon plate-like crystallites. With the aid of scanning mode (STEM) of a transmission electron microscope, equipped with a Si(Li)-detector system, both regions were analyzed for calcium and phosphorus by electronprobe X-ray microanalysis. In ten series of 106 measurements in each region, it could be determined by registration of the CaKalpha and PKalpha X-ray counts that the mineral content in the clusters was in the range of 30-100% higher than in the light regions. The question of the sequence of the epiphyseal plate mineralization is discussed and whether the dense clusters represent the mineralized matrix vesicles.


The hypothalamo-hypophysial system in acipenseridae. VII. The functional morphology of the peptidergic neurosecretory cells in the preoptic nucleus of the sturgeon, Acipenser güldenstädti Brandt. A quantitative study. The peptidergic neurosecretory cells (NSC) of the nucleus praeopticus (NP) of male and female sturgeons, A. güldenstädti Brandt, were studied light microscopically at different stages of their life cycle and under experimental conditions. Four main NSC types reflecting different phases of secretory cycle and life course of the cell have been tentatively distinguished. The maximum percentage of the high and moderate active NSC are found in juvenile animals in the sea (stages I and I-II of gonadal maturity, sgm), in upstream migrating fish in spring before spawning, in down-stream migrating fish 1-1.5 months after spawning, and in experimental fish kept for 8.5 hours in a 32% sodium chloride solution. The least active NSC accumulating neurosecretory material (NSM) are characteristic of juvenile fish (sgm II) in the sea, sturgeons maintained in a sodium chloride solution for 3.5 or 6 hours and fish which remained in a net, thrown to the sea, for some hours before fixation. The lowest percentage of these cells is observed in autumn migrants, in females soon after spawning (sgm VI) and in fish kept for 8.5 hours in a sodium chloride solution. Cells rich in basophilic substance and poor in NSM occur in juvenile and in down-stream migrating fish. Cells reflecting the state of exhaustion after hyperactivity and "ageing" cells are seen in adults, expecially in sgm VI fish, and in autumn migrants. Pyknomorphous NSC are constantly present in all fish; they are most numerous in sturgeons found in a net. A diagram demonstrating the life course and the secretory cycle of the NSC is presented and the role of the hypothalamo-hypophysial neurosecretory system (HHNS) under stress conditions is discussed.


Neutralization of diphtheria toxin in living cells by microinjection of antifragment A contained within resealed erythrocyte ghosts. When human erythrocytes suspended in phosphate-buffered saline (PBS) containing lgG were first dialyzed against a hypotonic solution and then dialyzed against PBS, lgG molecules were entrapped within resealed erythrocyte ghosts. The concentration of lgG inside the ghosts was about 33% of its concentration in the dialysis bag. With the aid of HVJ (Sendai virus), ghosts containing rabbit lgG antibody against fragment A of diphtheria toxin were fused with toxin-sensitive FL cells. The fused FL recipients were found to be resistant to the action of diphtheria toxin. Clones derived from the resistant recipient cells, however, became sensitive to the toxin again. Antifragment A neutralized the enzymic activity of isolated fragment A in vitro, but did not protect FL cells or rabbit skin against the complete toxin.


Appearance of interferon inducibility and sensitivity during differentiation of murine teratocarcinoma cells in vitro. Pluripotential embryonal carcinoma (EC) cells do not produce interferon after treatment with a wide variety of inducers, nor are they sensitive to its action. Several differentiated lines derived from the EC cells, however, both produce and are sensitive to mouse interferon. Differentiation of EC cells in vitro is accompanied by development of interferon inducibility and sensitivity.


Nucleosomal DNA is digested to repeats of 10 bases by exonuclease III. Nucleosomes were treated with increasing concentrations of exonuclease III (Exo III) from E. coli. At low levels of Exo III, the heterogeneous distribution of monomers (with associated DNA fragments ranging in size between 140 and 170 bp) is "trimmed" down to a discrete core of 140 bp. The "trimming" of monomers to 140 bp results from a 3' exonucleolytic digestion accompanied by a 5' clipping activity which is specific for the conformation of internucleosomal DNA. At higher concentrations of Exo III, the enzyme digests the 140 bp "trimmed" nucleosome core from both 3' ends without associated 5' nuclease activity. Most striking is the observation that the fragments produced during such a digestion display discrete single-stranded lengths that are integer multiples of 10 bases. For some dimer nucleosomes, Exo III can digest as many as 200 bases from at least one 3' end and produce a 10 base interval ladder from about 400 bases down to 180 bases. This suggests that the enzyme can traverse the length of an entire nucleosome without destroying whatever structural features are necessary to produce a 10 base DNA ladder.


Polypeptide maps of cells infected with murine type C leukemia or sarcoma oncovirus. The polypeptide composition of murine fibroblast cells and the effect of infection by RNA sarcoma and leukemia viruses were analyzed by two-dimensional gel electrophoresis and tryptic peptide mapping. The polypeptide maps of NIH Swiss mouse embryo fibroblasts (NIH/3T3) and BALB/c mouse embryo fibroblasts (BALB/3T3) were very similar except for two major polypeptides of about 65,000 and 75,000 daltons which were not detected in BALB/3T3 cells. NIH/3T3 cells infected with either Rauscher or Gross oncoviruses and outbred Swiss mouse embryo fibroblasts (3T3 FL) showed two major polypeptrides of about 73,000 and 80,000 daltons not found in uninfected NIH/3T3 cells. The 3T3 FL cells, although uninfected, were also found to contain a high concentration of envelope glycoprotein of an endogenous oncovirus. 3T3 FL cells transformed by Moloney sarcoma virus showed changes in many polypeptides, including several major components: the disappearance or modification of a component of 60,000 daltons, an increased concentration and shift in pl of a glycoprotein of 48,000 daltons, and the apparent loss of several smaller polypeptides. None of the major changes of the transformed cells were associated with cell surface proteins labeled by lactoperoxidase-catalyzed iodination.


Elimination of bagassosis in Louisiana paper manufacturing plant workers. The prevalence of bagassosis was investigated in a Louisiana paper mill, which in the past had considerable numbers of workers with the disease. Based on negative clinical histories and the low number of positive serological reactions of the workers' serum with Thermoactinomyces sacchari antigen, it was concluded that bagassosis was no longer present. This was thought to be due to a different method of storage of bagasse, which retards microbial decay and reduces airborne organic dust, and to the increased awareness of plant management resulting in greater safety measures.


Asthma caused by bromelin inhalation.

Asthma caused by bromelin inhalation. Two cases are reported of bronchial asthma caused by inhalation of bromelin, a proteolytic enzyme utilized in some anti-inflammatory medicine. Prick test results with bromelin extract were positive. Inhalation tests gave immediate reactions which were blocked by sodium cromoglycate, but not corticosteroids.


Immediate-type hypersensitivity to reactive dyes. Reactive dyes have gained extensive use in recent years. This paper reports four cases of immediate-type occupational allergy to these compounds. All the patients had had symptoms of asthma and allergic rhinitis, and had been weighing dyes for a minimum of 2 years. The skin prick tests were positive, and nasal and bronchial provocation challenges also produced positive immediate reactions. A high serum titre of specific IgE could be demonstrated for at least one dyd by the radioallergosorbent test. The identification of specific IgE shows that the mechanism of the hypersensitivity is immunological, reactive dyes acting probably as haptens.


Levels of complement components during allergen-induced asthma. The levels of circulating complement components C3 and C4, total haemolytic complement, CH50, as well as evidence of complement activation, have been studied in peripheral blood samples during allergen-induced asthma. No evidence of activation of the complement system was detected in these studies.


The danger of "yellow dyes" (tartrazine) to allergic subjects. Oral administration of 50 mg tartrazine to 122 patients with a variety of allergic disorders caused the following reactions: general weakness, heatwaves, palpitations, blurred vision, rhinorrhoea, feeling of suffocation, pruritus and urticaria. There was activation of the fibrinolytic pathway as shown by reduction of plasminogen with high pre-kallikrein and low kallikrein values. Reduction in complement activity (CH50) was seen in three out of sixteen reactions.


Serum IgE levels in giardiasis.

Serum IgE levels in giardiasis. Raised levels of serum immunoglobulin E are found in many parasitic diseases. In order to determine the influence of Giardia lamblia on IgE levels of clinically symptomatic patients, a controlled study was performed. There was no difference between the serum IgE values from Brazilian patients with giardiasis and those from normal Brazilian controls, although in both groups there were many individuals with values higher than the normal range reported from the northern hemisphere.


Method for screening urinary steroids by gas chromatography. Numerous methods are available for measuring urinary steroids in evaluating endocrine dysfunctions. Measurements of these particular steroids, or groups of them, usually involve tedious isolation methods, corrections for interferences and losses of the steroid, and (or) expensive reagents. We show how gas-liquid chromatography provides a rapid, sensitive, and direct method for several steroid metabolites in urine. Androstanol, androsterone, etiocholanolone, dehydroisoandrosterone, pregnanediol, pregnanetriol, 11-keto-17-ketosteroids, and the 11beta-hydroxy-17-ketosteroids can be identified and quantified.


Determination of pyruvate oxidation rate and citric acid cycle activity in intact human leukocytes and fibroblasts. We measured pyruvate oxidation in intact leukocytes and fibroblasts by measuring 14C02 production. The optimal pyruvate concentration appeared to be higher than that usually applied. Activities remained constant during the incubation and were proportional to the amount of tissue protein added. Man values (+/-SD) were 2.8 +/- 0.9 nmol/h per 10(6) cells and 37 +/- 14 nmol/h per mg of protein for leukocytes and fibroblasts, respectively, for [1-14C]pyruvate oxidation; and 2.1 +/- 0.8 nmol/h per 10(6) cells and 18 +/- 7 nmol/h per mg of protein, respectively for [2-14C]pyruvate oxidation. We compared oxidation rates of pyruvate and 2-oxoglutarate by intact cells with those of isolated mitochondria. The ratio of 14CO2 production vs. activity of mitochondrial marker enzyme demonstrated that the rate of pyruvate oxidation can adequately be assayed in intact cells, but that the permeability of the cell membrane is rate-limiting in the oxidation of 2-oxoglutarate. No significant oxidation of other intermediates of the citric acid cycle was found, presumably owing to a low rate of transport of these substances across the cell membrane.


Measurement of free and free-plus-peptide hydroxyproline fractions in plasma. Plasma hydroxyproline fractions--free-plus-peptide and free--were determined by a method involving centrifugal ultrafiltration and the procedure of Kivirikko et al. [Anal. Biochem. 19, 249 (1967)]. Within- and between-day precision (CV) for the combined fractions was 4--5% and 2.8--6%, respectively. Mean analytical recoveries of free hydroxyproline were 95.2% (87--109%) in the normal range, and 97% (91--108%) in the above-normal range. Normal ranges for plasma hydroxyproline fractions, based on data for 11 men and 19 women, were free-plus-peptide, 7.5--25.3; free, 4.9--22.7; and peptide (calculated), 0.1--5.1 mumol of hydroxyproline per litre, respectively. These ranges showed no sex-related differences and were gaussian in distribution. A factor was derived to transform data on concentrations in ultrafiltrate into plasma concentrations.


Variance components of serum constituents in healthy individuals. Analytical, intra-individual, and inter-individual components of variance were estimated in 10 volunteers for 34 assays encompassing 22 different constituents. Replicate blood specimens were obtained four times weekly. Nine constituents were measured with more than one instrument [Technicon AutoAnalyzer II and SMAC System, Perkin-Elmer Kinetic Enzyme Analyzer KA-150, and (or) the Abbott Bichromatic Aanalyzer ABA-100]. For those constituents that were stored for randomized batch analysis, results were examined for evidence of changes during storage and within-run analytical drift. Alkaline phosphatase, cholesterol, dopamine-beta-hydroxylase, and SMAC-measured lactate dehydrogenase had a ratio of intra-individual to interindividual variance of less than 0.10, thus exhibiting a high individuality. This ratio was greater than one for sodium, carbon dioxide, and creatine kinase. Analytical variance was more than 30% of total variance for sodium, carbon dioxide, calcium, total protein, and chloride. Analytical variance was less than 20% of intra-individual variance for bilirubin, creatine kinase, KA-150-measured lactate dehydrogenase, triglycerides, and urea nitrogen. Limits for the expected difference between measurements of the same constituent for the same individual on different days are also presented.


Hyperlipoproteinemia phenotype determination by agarose gel electrophoresis updated. Hyperlipoproteinemia phenotyping has been re-evaluated by an improved agarose gel electrophoretic test. Eight varieties of serum lipoprotein electrophoretic patterns are demonstrated, two from clinically normal normolipidemic subjects and six from patients with hyperlipoproteinemia that include the phenotypes 1, 2a, 2b, 3, 4, and 5. The sharp delineation of the lipoprotein patterns achieved by this technique facilitates the differentiation and identifcation of the lipoprotein phenotypes. Furthermore, the lipoprotein patterns can be visually evaluated, correlated with their corresponding serum lipid values, and associated with the clinical and hereditary features of the hyperlipoproteinemia phenotypes. This test system can also be used in clinical trials and epidemiological studies.


Hemopyrrole and kryptopyrrole are absent from the urine of schizophrenics and normal persons. We describe a method for detecting hemopyrrole and kryptopyrrole in urine, with a detection limit of 100 mug/liter (1 part in 10(7)). Urine is thoroughly extracted with methylene chloride and the extract is concentrated and examined by gas chromatography and gas chromatography-mass spectrometry. No hemopyrrole or kryptopyrrole could be detected in 52 samples, from 17 controls, 29 schizophrenics, and six persons with acute intermittent porphyria.


Immobilized-enzyme nylon-tube reactors for routine determination of urea and citrulline in serum. A continuous-flow clinical analyzer for the routine estimation of urea is described that makes use of an immobilized-enzyme nylon-tube reactor as part of a flow-through system (a Technicon AutoAnalyzer I). Results of blood-urea analyses by use of the immobilized urease are compared with determinations made with the diacetyl monoxime method and the urease solution method. Clinical trials carried out routinely with the immobilized enzyme nylon tube reactor give reliable and reproducible results with high precision and low cost. The reactors are stable to intermittent or continued use for at least four months or for 2000 tests. A method is described in which differential colorimetry is used for determining citrulline in blood and which makes use of the immobilized urease, albeit indirectly.


Methods compared for determining zinc in serum by flame atomic absorption spectroscopy. We compared two methods for determination of serum zinc by flame atomic absorption spectroscopy. The first involved 10-fold dilution of serum with water; the second, deproteinization of serum with trichloroacetic acid. Analytical recovery of Zn2+ added to serum averaged 99.3 and 99.9%, respectively, by the two methods, but measured concentrations were consistently greater by the second method [mean difference, 118 +/- 27 (SD) mug/liter]. For the analysis of 55 sera, measured concentrations were also greater by the second method [mean difference, 91 +/- 28 (SD) mug/liter]. We dialyzed serum to remove most of the zinc and measured analytical recovery of increasing amounts of Zn2+ added to this dialyzed serum or, conversely, of zinc in a mixture of increasing volumes of dialyzed serum in a Zn2+ standard. Recovery results for the dilution method showed an interference by an unidentified, but nondialyzable serum component(s). Recovery was not improved by use of (a) a "high-solids" burner, (b) a diluent containing 1-butanol, or (c) a Mn2+ internal standard.


Creatine kinase in serum: 4. Differences in substrate affinity among the isoenzymes. The goal of this work was to find out whether it is possible to measure all three creatine kinase isoenzymes under the same reaction conditions in spite of their different kinetic properties. We found the tightest substrate binding for purified human BB, followed by the MB And MM isoenzyme preparations for both creatine phosphate and ADP. An increase in substrate concentration usually resulted in an inhibition. Nevertheless, it was possible with a method optimized for the MM isoenzyme also to measure the BB and MB isoenzymes at a rate of inhibition of only 6 and 3%, respectively. Marked differences in the apparent Km values between purified and native MM isoenzyme in human serum may indicate that the enzyme declined in substrate affinity during the isolation procedure. The use of enzyme preparations for standardization purposes, therefore, is only suitable if their kinetic properties are close to those of the enzyme in serum. Difficulties in the calculation of the apparent Km values are discussed and the graphical procedures of Lineweaver and Burk and of Eisenthal and Cornish-Bowden compared.


Determination of uric acid on continuous-flow (AutoAnalyzer II and SMA) systems with a uricase/phenol/4-aminophenazone color test. This report describes a new specific colorimetric procedure for uric acid assay with AutoAnalyzer II and SMA (Technicon) systems, made specific by the application of uricase. Hydrogen preroxide, formed in this reaction, effects the oxidative coupling of 4-aminophenazone and 2,4-dichlorophenol under the catalytic influence of peroxidase. The red dye formed is measured at 505 or 520 nm. A sample blank measurement is not necessary, and the reagents show very good stability. The test shows linearity up to 714 mumol of uric acid per liter. Results of thie method correlate very well with those by the uricase-ultraviolet and uricase--catalase methods. There is no interference by hemoglobin, bilirubin, lipemia, and various drugs, except a minor interference by alpha-methyldopa. Interference from ascorbate is eliminated by ascorbate oxidase. This method can be regarded as a considerably improved routine test for uric acid on continuous-flow systems in clinical laboratories as compared with the commonly used phosphotungstate method.


Automated assay of gamma-aminobutyric acid in human cerebrospinal fluid. We describe an automated amino acid analyzer with fluorescence detection (o-phthalaldehyde) which permits sensitive and rapid determinations of gamma aminobutyric acid in human cerebrospinal fluid. Concentrations as low as 50 nmol/liter can be accurately determined in 100 mul samples at the rate of one sample per hour. Concentrations in untreated cerebrospinal fluid increase rapidly after sampling by lumbar puncture. The concentration in immediately deproteinized samples from 38 patients with intervertebral disc disorders was 220 +/- 81 nmol/liter (mean +/- SD).


Sensitive radioimmunological screening test for antithyroglobulin autoantibodies. The test described here was designed as a screening test to be used in conjunction with the radioimmunoassay for human thyroglobulin. Anti-thyroglobulin autoantibodies, when present even in low concentrations, interfere with thyroglobulin determination. A 30-min incubation allows binding of 125I-thyroglobulin to endogenous anti-thyroglobulin autoantibodies. A subsequent 2-h incubation with goat anti-human gamma-globulin causes precipitation of such complexes. The immunoprecipitable radioactivity reflects the binding capacity of the sample for 125I-labeled thyroglobulin. Samples that are devoid of autoantibodies, and are therefore suitable for valid thyroglobulin determinations, bind less than 6% of the radiolabeled thyroglobulin. The sensitivity of this radioimmunoassay exceeds that of the tanned-erythrocyte hemagglutination test.


Determination of quinidine by high-performance liquid chromatography. Quinidine in serum was measured at 330 nm, after protein precipitation, with an alkyl phenyl reversed-phase chromatographic column by peak-height determination (external standards.) Sensitivity was 0.3 mg/liter, with linear response to at least 10 mg/liter serum. Interassay precision, measured on 20 consecutive days, gave a CV of 8.2% at 2 mg/liter of serum and 5.1% at 5 mg/liter. Quinine and primaquine are not separable from quinidine under the assay conditions, and dihydroquinidine and chloridazepoxide are only partly resolved. No assay interference was encountered with a series of control serum samples obtained from patients with various diseases, who were being treated with various drugs other than quinidine, except in one serum sample with a high bilirubin concentration (300 mg/liter). If such an assay interference is present, an alkaline extraction of quinidine before analysis has to be used. Results by our assay and those by a single-extraction fluorescence method correlated poorly (r=0.87), and the fluorescence assay gave 50% +/- 7% (SEM) higher values than our method, due to chromatographic separation of a major fluorescent non-phenolic metabolite of quinidine, which can also be measured by our assay.


Determination of chromium and cobalt in human serum by neutron activation analysis. Confusion exists about the chromium and cobalt concentrations in the serum of healthy individuals. We determined these elements by neutron activation analysis. The samples were irradiated during 12 days at a flux of approximately 10(14) neutrons.cm-2.s-1. Chromium was selectively separated by distillation after the irradiation. We obtained the following values (mean +/- standard deviation): 0.160 +/- 0.083 mug/liter for chromium, and 0.108 +/- 0.060 mug/liter for cobalt.


Tartrate-resistant (band 5) acid phosphatase activity measured by electrophoresis on acrylamide gel. A tartrate-resistant acid phosphatase was isolated from a huma spleen infiltrated with reticulum cells of leukemic reticuloendotheliosis. The purified enzyme was used to establish the optimal conditions for quantitative analysis of this enzyme by electrophoresis on acrylamide gel. As little as 0.1 unit of enzyme activity (or 1 ng of the purified enzyme protein) could be quantitatively detected when it was mixed with 4 mg of albumin before electrophoresis.


Individual character of variation in time-series studies of healthy people: II. Differences in values for clinical chemical analytes in serum among demographic groups, by age and sex. Assessment of the significance of an observed set of serum chemical values for determining a person's state of health requires comparison with a set of defined reference values. We tested the assumption that a reference group of individuals, categorized by age and sex, gives a narrower range of variation than does a larger mixed population. If this were true, the demographic set would be a more sensitive reference than is the customary "normal range" for interpretation of values occurring in the individual. The ratio, R, of intra-personal to inter-personal (group) standard deviations was similar for defined age/sex classes and the overall group for 16 serum constituents. When the "raw" intra-individual variation (biological plus analytical variation) was adjusted to remove the average analytical component, the resulting R was less than 80 for all constituents except creatine kinase, which indicates that these are all particularly strong "discriminators" of individuality. These results imply the need for individual rather than population-based reference ranges, even if the latter are from persons of similar age and the same sex.


Simplified two-step column-chromatographic determination of taurine in urine. A two-step column-chromatographic procedure for accurate and rapid determination of taurine in urine is described. Sulfosalicyclic-acid deproteinized samples are chromatographed on a 0.9 X 10 cm column of cation-exchange resin (AG 50W-XB), with use of a pH 2.2 sodium citrate eluting buffer such that taurine and the more highly acidic compounds in urine are eluted in the void volume, and then on a 0.9 X 8 cm column of anion-exchange resin (AG 2-X8), from which taurine is preferentially eluted with 1 mol/liter acetic acid. The color developed with ninhydrin is directly proportional to taurine amounts as low as 0.01 mumol/sample. The method is highly reproducible, with analytical recoveries greater than 95%. The presence of 333 mumol of urea and 1 mumol of cysteic acid did not interfere in the analysis. When a mixture of C14-labeled amino acids other than taurine were co-chromatographed with taurine, less than 2% of the total counts loaded were located in the taurine fraction. Values for urinary taurine excretion by rats according to the present method agreed well with values obtained with an automated amino acid analyzer. Advantages of the present method for the determination of taurine are discussed.


Analytical performance and comparability of the determination of triglycerides by 12 Lipid Research Clinic laboratories. Twelve Lipid Research Clinic laboratories performed automated fluorometric triglyceride analyses on four control serum pools of known concentration by a modified Hantzsch reaction. The analyses were done during a two-year period, with use of common standards, methodology, and quality-control procedures. Estimates of analytical bias, variability, and short- and long-term trends for each instrument and for the entire group of LRC instruments are presented. High accuracy, precision, and interlaboratory comparability were achieved through rigorous standardization and control of the entire analytical procedure. Individual instrument biases varied from an average of 4.9% below to 1.0% above reference values. Between-run variability was often less than within-run variability and interlaboratory variation was substantially less than intralaboratory variation. The total standard deviation for all instruments ranged from 37 to 63 mg/liter. Only 5 to 14% of this variation was due to differences among instruments. The among-instruments standard deviation ranged from 12 to 17 mg/liter; the between-run, within-instrument standard deviation ranged from 29 to 46 mg/liter, and within-run standard deviation from 27 to 40 mg/liter. The significance of the results for long-term collaborative studies is discussed.


Solid-phase radioimmunoassay for morphine, with use of an affinity-purified morphine antibody. Morphine antibody purified by affinity chromatography was used to develop a solid-phase radioimmunoassay for morphine in polystyrene tubes. The tubes are coated with an appropriate concentration of the purified antibody, rinsed three times with buffered saline, and stored at -15 degrees C. Using tritiated dihydromorphine, we determined competitive morphine binding by difference when the radioactivity in the assay supernates was measured after incubation (1 h, 37 degrees C). Five standard curves, with use of serum equivalents of morphine ranging from 0 to 6 mug/liter, were linear and had a mean correlation coefficient of 0.98. Uncer conditions of the assay, levorphanol was comparable to morphine in its inhibitory effect on binding of labeled dihydromorphine, whereas dextrorphan was essentially inactive. Morphine-3-glucuronide, a major metabolite, is 55-fold less inhibitory in terms of its capacity to displace the radiolabel. We believe that the sensitivity of the technique, coupled with the simplicity of nonseparatory sampling, renders the system suitable for rapid determination of morphine and related compounds in biological fluids.


Automated measurement of serum thyroxine with the "ARIA II," as compared with competitive protein binding and radioimmunoassay. Two conventional serum thyroxine assays, run in separate laboratories, one by competitive protein binding and one by radioimmunoassay, were used to evaluate the automated ARIA II (Becton Dickinson Immunodiagnostics) serum thyroxine assay. Competitive protein binding as compared to ARIA II with 111 clinical serum samples gave a slope of 1.04 and a correlation coefficient of 0.94. The radioimmunoassay comparison to ARIA II with 53 clinical serum samples gave a slope of 1.05 and a correlation coefficient of 0.92. The ARIA II inter-assay coefficient of variation for 10 replicates of low, medium, and high thyroxine serum samples was 6.2, 6.0, and 2.9%, respectively, with an inter-assay coefficient of variation among 15 different assays of 15.5, 10.1, and 7.9%. The automated ARIA II, with a 2.2-min cycle per sample, gives results that compare well with those by manual methodology.


High-speed automated atomic absorption spectrophotometry. We describe an integrated automated system for the atomic absorption spectrophotometer. The system makes use of a light-dependent resistor to detect the presence of a marker ion which is present along with the sample ion in the flame. An electronic circuit has been developed which enables the marker ion to trigger the read signal of the spectrophotometer. The system has been tested by determining magnesium and calcium in serum. Alternative modes of operation and different potential applications are discussed.


Gas-chromatographic method for plasma acetate analysis in acetate-intolerance studies. We describe a modified gas-chromatographic method for acetate in serum or plasma, intended for use in the investigation of acetate intolerance in hemodialysis patients. The assay may be adapted for use with a single-column gas chromatograph equipped with a flame ionization detector. The analysis, made isothermally, requires only 0.5 ml of plasma or serum. Only one deproteinizing step is required to prepare the sample for analysis. Additionally, we present preliminary findings of an ongoing acetate-intolerance study.


Faster determination of clottable fibrinogen in human plasma: an improved method and kinetic study. Clottable fibrinogen in human plasma was determined by measuring spectrophotometrically the increase in turbidity with time due to the fibrinogen-fibrin conversion with thrombin. From the maximal absorbance, Amax, at 450 nm obtained 2 min or less after thrombin as added to plasma, we estimated the fibrinogen concentration in plasma of normal subjects and patients. Analysis of the rate of the absorbance increase yielded the Km value, 1.6 X 10(-5) mol/liter, which closely agrees with the Km of 1.2 X 10(-5) mol/liter obtained by analysis of the fibrinopeptides released from fibrinogen.


High-performance liquid-chromatographic determination theophylline in plasma. A high-performance liquid-chromatographic method is reported for monitoring theophylline in plasma. Samples are deproteinized with 2.5 volumes of acetonitrile and the supernates chromatographed on a reversed-phase column. Absorption at 275 nm is monitored. One can accurately measure 1.5 mg of theophylline per liter, in as little as 10 microliter of plasma, and only about 7 min is required per sample. No interference was found in plasma samples from asthmatic patients. This method is particularly useful for routine therapeutic monitoring of both pediatric and adult patients.


Improved ultraviolet spectrophotometry of serum theophylline. We present an improved method for ultraviolet spectrophotometry of theophylline in serum. We studied various extraction techniques aimed at eliminating interferences from co-extractable serum constituents. In the resulting modified procedure, 1 ml of serum is required and a salt-solvent pair of ammonium sulfate and chloroform/hexane is used for extraction. The solvent forms the top phase after extraction, the lower phase after back-extraction, thereby permitting easy removal of the appropriate phase from culture tubes. The use of ammonium sulfate coupled with the added specificity of the extraction solvent results in an extract with low background absorption and a well-defined spectrum for the extracted theophylline.


Preparation of ligand-free human serum for radioimmunoassay by adsorption on activated charcoal. I describe a convenient method for stripping hormones and other ligands from human serum. Formation of a serum/charcoal colloid is avoided by incubating serum on a limited surface area with activated charcoal, in a lateral oscillating shaker. Particle-free serum of negligible turbidity is obtained without ultracentrifugation by ejecting the centrifugate through a cellulose ester membrane. By this technique, more than 80% of thyrotropin, triiodothyronine, thyroxine, cortisol, insulin, digoxin, folate, estriol, or an ether derivative of testosterone is removed from serum. About 70% of follitropin and somatotropin are removed, as well as half the choriogonadotropin. Serum protein remains intact throughout the adsorption process.


Liquid chromatographic assay of cerfuroxime in serum. We describe a procedure for determining cefuroxime concentrations in serum by using high-performance liquid chromatography. The drug is extracted from serum with dimethylformamide and separated from other substances in the extract by reversed-phase chromatography. The ultraviolet (280-nm) absorption of the effluent was monitored and quantitated based on the height of the cefuroxime peak. Intra-and inter-assay imprecision (cv) was less than 3.1 and 4.3%, respectively. Serum concentrations as low as 1.0 mg/liter could be accurately measured. No interference from various other drugs and antibiotics was found. A biological half-life of 52 min in serum was observed after intravenous injection of the drug into a human volunteer.


Spectrophotometry of theophylline-7-acetic acid and theophylline. A spectrophotometric assay procedure is described for individually measuring theophylline-7-acetic acid and theophylline in 2.0 ml of serum. Absorbance is a linear function of concentration over a range of 0.5-40 mg/liter for theophylline-7-acetic acid and 0.5-40 mg/liter for theophylline. No endogenous or exogenous compounds were found that interfere with theophylline-7-acetic acid determinations. As with other spectrophotometric theophylline assays, theobromine and, to a slight extent, phenobarbital interfere with theophylline determinations.


Automated serum albumin determination by use of the immediate reaction with bromcresol green reagent. It has been demonstrated recently that the reaction of serum samples with bromcresol green reagent proceeds in two steps, albumin being responsible for the immediate reaction and other serum proteins for the slower one. I show here that the immediate reaction, used for albumin determination, can be automated. Two different automated systems are described: the LKB 2086 Reaction Rate Analyzer and the multichannel analysis system LKB 2480 Prisma. With the first system, 60 (or 120) samples per hour were run with a within-day standard deviation of 0.3 g/liter; with the second system, a feed rate of 150 samples per hour was used (SD, 0.3 g/liter, within-day). Comparison with other methods gave the following equations: y (LKB 2086) = 1.44 + 0.97 X (immunodifussion) (n = 43; r = 0.98) and y(Prisma) = 2.04 + 0.96x (manual method) (n = 73; r = 0.98). Thus albumin determinations can be done reliably, quickly, and simply at low reagent and labor cost.


Evaluation of a radiometric method for determination of total and unsaturated iron-binding capacities and serum iron. We describe an evaluation of the "RES-OMAT FE-59" radiometric kit (Mallinckrodt Australia Pty. Ltd.) for determination of total iron-binding capacity and unsaturated iron-binding capacity; serum iron may be calculated from total iron-binding capacity and unsaturated iron-binding capacity. Values obtained on patients' sera were compared with those obtained by continuous-flow analysis; correlation coefficients were 0.92, 0.93, and 0.88 for total iron-binding capacity, unsaturated iron-binding capacity, and iron, respectively. Precision between-run and within-run was almost identical and compares very favorably with that reported by Dixon [Ann. Clin. Biochem. 10, 127 (1973)] and that achieved in inter-laboratory surveys. Analytical recovery averaged only 83.5%, but results of analyses of sera with assigned or consensus values showed good accuracy. Satisfactory performance cannot be achieved with lyophilzed bovine quality-control materials. The kit has significant technical advantages over colorimetric methods and good short- and long-term analytical performance.


Measurement of chloride in sweat by use of a selective electrode and strip-chart recorder. We describe a method for direct potentiometric measurement of sweat chloride by use of a chloride-selective electrode, with strip-chart recording of the measurement to facilitate interpretation of the measurement. Comparison of this method and the Gibson and Cooke method [Pediatrics 23, 545 (1959)] gave a correlation coefficient of 0.86. Recording of the same test at various pressures showed that different pressures had little effect if they were kept constant.


Pitfalls of the alcohol dehydrogenase procedure for the emergency assay of alcohol: a case study of isopropanol overdose. We describe a case of ethanol and isopropanol ingestion that resulted in coma. The concentration of ethanol and isopropanol was 0.90 and 1.65 g/liter in serum and 3.12 and 5.34 g/liter in gastric contents. With an enzymatic (alcohol dehydrogenase) method for ethanol determination we obtained erroneous analytical results. Because of partial cross reactivity with isopropanol, ethanol concentration was overestimated and total alcohol (i.e., the contribution of isopropanol) was underestimated. This was recognized by measuring serum osmolality. Differences between measured and calculated serum osmolality that are not accounted for by the serum ethanol concentration as determined by an enzymatic ethanol method must be further investigated by specific methods to see if other alcohols are present.


Serum lipids in treated diabetic children and their families. Fasting lipid concentrations have been measured in fifty treated juvenile diabetics, their siblings and parents to determine which types of hyperlipoproteinaemia co-exist with juvenile diabetes and whether the abnormalities relate to diabetic control, or represent familial disorders. Lipid concentrations amongst the parents did not differ from adult control. Triglyceride concentrations were significantly higher in those diabetic children with fasting blood glucose concentrations greater than 10 mmol/l than those with concentrations less than 10 mmol/l. The latter group had similar triglyceride levels to non-diabetic siblings. Cholesterol concentrations were not related to fasting blood glucose and were similar in diabetic and sibling controls. Hyperlipoproteinaemia (types IIa, IIb and IV) was present in ten of the diabetic patients. Six of the nine diabetic patients with raised cholesterol had at least one parent with cholesterol in the highest quintile for the control population, whereas only six of the forty-one with lower levels had parents in this category. A similar trend for cholesterol was apparent amongst the non-diabetic siblings. However, no association was apparent between the triglyceride levels of diabetics (or their siblings) and parents. Thus although hyperlipidaemia associated with juvenile diabetes appears to be largely due to inadequate control, raised cholesterol concentrations frequently occur.


Bromoergocryptin treatment of acromegaly persisting following conventional therapy. Bromoergocryptine has been used to lower growth hormone concentrations in ten patients with acromegaly in whom previous attempts at pituitary ablation had failed to cure the disorder. Plasma immunoreactive and plasma receptor-reactive growth hormone concentrations together with plasma somatomedin concentrations and urinary excretion of immunoreactive growth hormone were used to assess the response to treatment. Casual immunoreactive hormone concentrations in plasma were lowered to less than 8 mu/l and to less than 5 mu/l during glucose infusion in seven patients, and urinary growth hormone excretion was also brought into the normal range (less than 40 micromicron/12 h) in this group. There was at least a 40% reduction in these measurements in the remaining three patients who had the highest basal hormone concentrations of the group. Plasma somatomedin fell with treatment in eight patients, and intravenous glucose tolerance improved in seven of eight patients tested. Used in modest dosage (up to 15 mg/day) bromoergocryptine can lower plasma and urinary growth hormone and plasma somatomedin concentrations in acromegalic patients in whom previous treatments had decreased but not cured hormone overproduction.


Metergoline inhibition of thyrotrophin and prolactin secretions in primary hypothyroidism. The effect of acute oral administration of metergoline on serum thyrotrophin and prolactin levels in six patients with primary hypothyroidism was studied. Metergoline 4 mg by mouth caused a significant decrease in the concentration of serum thyrotrophin and prolactin in all subjects. There was no consistent change in serum thyroxine and triiodothyronine concentrations during the experiment. These findings suggest that metergoline inhibits prolactin and thyrotrophin secretion by a direct action on the hypothalamus or pituitary gland.


Effect of fluphenazine on pituitary function in man. The growth hormone (hGH) and prolactin (hPRL) response to insulin induced hypoglycaemia was studied in six alcoholics on two occasions before and after treatment with a single intramuscular injection of fluphenazine (Modecate). On both occasions blood samples were taken at intervals before and after the intravenous injection of soluble insulin (0.1 u/kg body weight). The patients were investigated on the first occasion, 2-7 days after cessation of drinking and they all demonstrated an adequate hGH response. They then received an injection of fluphenazine (Modecate 12.5 mg) and were reinvestigated 1 week later. The hGH response to hypoglycaemia was significantly impaired after treatment with fluphenazine. Basal hPRL concentrations were significantly increased and increased concentrations of hPRL in response to hypoglycaemia occurred after treatment. We conclude that a single injection of fluphenazine (Modecate 12.5 mg) has a marked effect on hypothalamic-pituitary mechanisms controlling hGH and hPRL release.


Failure of somatostatin to diagnose organic hyperinsulinism. In four patients with organic hyperinsulinism (two with surgically proven beta-cell adenomas of the body of the pancreas) a standard tolbutamide test during continuous somatostatin infusion (5 microgram/min) was carried out. Tolbutamide induced insulin release was completely inhibited by somatostatin as in normal subjects. These results suggest that the inhibition test with somatostatin does not seem to be a better or safer way of diagnosing insulin producing tumours.


A new syndrome characterized by mental retardation, epilepsy, palpebral conjunctival telangiectasias and IgA deficiency. Mental retardation, epilepsy, palpebral conjunctival telangiectasias and diminished serum IgA, with a particular facies and shortened fifth finger were found in a 12-year-old Mexican girl. She has six siblings, of whom five have the same characteristics. The parents and the elder sister were not affected, and there was no history of consanguinity. This seems to be a new syndrome, and as both sexes are affected, the parents are normal and several siblings have the same syndrome, we postulate an autosomal recessive mode of inheritance.


Galactose-1-phosphate accumulation by a Duarte-transferase deficiency double heterozygote. An infant, suspected of having galactosemia following a positive screening test on dried blood spots, was shown to be a Duarte-transferase deficiency compound heterozygote through studies of electrophoretic mobility of the transferase enzyme in blood from the patient and family members. No rise in blood glucose was seen following oral ingestion of galactose. At the same time, galactose rose in plasma and was excreted in the urine; galactose-1-phosphate accumulated in erythrocytes. A galactose-free diet was considered the prudent course in the presence of the patient's inability to metabolize galactose completely.


Osteopathia striata with cranial sclerosis. An autosomal dominant entity. The syndromic association of striae in the long bones and pelvis, together with sclerosis of the base of the skull, has been investigated in four families. Impairment of hearing and alteration in the shape of the head are the most important clinical manifestations. Spinal abnormalities are an inconsistent feature. The distribution of affected individuals in the kindreds is compatible with autosomal dominant inheritance.


Fine structure alterations of elastic fibers in pseudoxanthoma elasticum. Examination by electron microscopy of the elastic fibers of individuals with Pseudoxanthoma Elasticum (PXE) revealed that the principal alterations were in the elastin moiety of the elastic fibers. The elastin had a granular appearance, an increased affinity for cationic stains, and it often demonstrated sites of increased density presumed to represent foci of calcification. In contrast to the elastin, the microfibrillar component of the elastic fibers was unchanged, both in morphologic appearance and in distribution. There was no clear correlation between the extent of the morphologic alteration in the elastic fiber and the level of clinical severity. Morphologically altered fibers were often found together with unaltered fibers. Changes similar to those seen in patients with PXE were also found in biopsies obtained from clinically unaffected consanguinous relatives. The pattern of inheritance in several of the families examined was compatible with autosomal recessive, whereas in at least one family a more complex mode of transmission seems likely. The electron microscopic data therefore provide further support for the genetic heterogeneity of PXE.


Prenatal diagnosis of 5p-.

Prenatal diagnosis of 5p-. With the combination of the various banding techniques (G,Q, and R), a small deletion of the short arm of a No.5 chromosome was detected prenatally in the pregnancy of a 39-year-old woman. The deletion appeared to be either intersitial in nature, involving part of p13 and p14, or the result of a translocation with deletion of p13 leads to pter. Both parents were found to have a normal chromosome constitution with normal banding patterns. Thus, this deletion was a de novo event. Repeat amniotic fluid cell chromosome analysis at the time of elective abortion, and postmortem examination of the fetus confirmed the prenatal cytogenetic diagnosis. We wish to emphasize that precise identification of a small deletion, as in this case, requires a combination of the various banding techniques.


Two cases of an abnormal short arm of chromosome 8 (8p+) associated with mental retardation. Morphologically similar chromosome anomalies, 8p+, were found in two inmates of an institution for the mentally retarded. Analysis of the G-and R-banding patterns showed that the first subject had a duplication of region p2 of chromosome 8; the second subject had an insertion of an unidentified chromosome segment at 8p11. Both subjects were severely mentally retarded. The physical malformations were more severe in the second subject than in the first, who had only minor signs. The dermatoglyphics are recorded.


Tick paralysis in three children. The diversity of neurologic presentations. Reviewed are 3 cases of tick paralysis in children each with a different presentation. One child presented with an ascending flaccid weakness, another with weakness and cerebellar signs, and a third with pure cerebellar signs. Ixodes scapularis, the black-legged deer tick, was the offending tick in Case 3 and apparently has not been previously reported to cause paralysis in humans. Because of the potential for a fatal outcome, it is imperative to consider tick paralysis in any child with an ascending flaccid weakness or acute ataxia.


Hemothorax in a child. An unusual cause of chest pain. The pediatrician should search carefully in a child with chest pain for evidence in the history or physical examination of an organic cause. Hemothorax is one of the pathologic processes that can present with this symptom. The differential diagnosis of hemothorax in children is reviewed.


Concurrent antagonism of isoproterenol and norepinephrine after labetalol. Labetalol reduces blood pressure in normotensive and hypertensive subjects. The effects of a therapeutic dose of intravenous labetalol upon the cardiovascular responses to intravenous isoproterenol and norepinephrine in 6 normotensive subjects were studied in order to investigate the drug's mode of action. Before labetalol, intravenous isoproterenol increased heart rate and reduced diastolic blood pressure in a dose-dependant manner; likewise, intravenous norepinephrine increased both systolic and diastolic pressure. The order of administration of these agonists was randomized between the subjects before and after labetalol. Following labetalol (1.5 mg/kg intravenously) the effects of isoproterenol were antagonized such that cumulative log-dose response curves of mean isoproterenol-induced increases in heart rate and reductions in diastolic pressure were shifted to the right in a parallel manner to approximately the same extent. At the same time, the mean norepinephrine-induced increases in systolic and diastolic blood pressure were also antagonized in a competitive manner. These responses were compared with others in the same subjects under the same conditions and it was concluded that the antihypertensive effect of labetalol is explained by concurrent blockade of alpha-and beta-adrenoceptors.


Increase in diuretic effect of chlorothiazide by probenecid. Thiazide diuretics reach their presumed intraluminal site of action by active transport at the organic acid secretory site of the proximal tubule. Probenecid competes for this transport and might therefore affect the diuresis induced by thiazide at that site. Doses of 500 mg and 1 gm of chlorothiazide (CTZ) intravenously to 5 volunteers with probenecid pretreatment increased 8-hr rates of excretion of sodium and urine over that without probenecid. Eight-hour excretion of sodium after administering 500 mg of CTZ was 147 +/- 7.5 mEq and 257.9 +/- 16.4 mEq after CTZ with probenecid (p less than 0.0005). The volume of urine after CTZ was 728 +/- 37 ml and 1,886 +/- 301 ml after CTZ with probenecid (p less than 0.001). This increase was associated with prolongation of CTZ diuresis rather than increase in intensity. These results are consistent with CTZ reaching its site of action from the peritubular side or that prolonged exposure of the lumen to lesser amounts of filtered CTZ causes a greater overall effect.


Physiologic disposition of lergotrile.

Physiologic disposition of lergotrile. Lergotrile, an ergot alkaloid, has been shown to be effective in treating disorders associated with elevated serum prolactin levels (e.g., galactorrhea-amenorrhea). Lergotrile has also been found to be a potent dopaminergic agonist and thus to be effective in Parkinson's disease. This study describes the physiologic disposition of lergotrile after administration to human volunteers. N-14CH3-lergotrile was rapidly absorbed from the gastrointestinal tract. Lergotrile was detected at low concentrations in plasma when subjects received large doses over extended periods of time. The major portion of radioactivity in plasma was attributed to the presence of circulating metabolites of lergotrile. Lergotrile metabolities were eliminated in the feces (ca. 60%), urine (ca. 20%), and breath (ca. 7% as 14CO2). A metabolite in feces was identified as 13-OH-lergotrile (up to 30% of the dose). A metabolite in urine was formed by conversion of the C8-acetonitrile group of lergotrile to a carboxyl group (about 10% of the dose). The presence of 14CO2 in the expired air after administering N-14C-methyl-lergotrile indicated that the drug was N-demethylated to form norlergotrile.


Hemodynamic and respiratory effects of morphine and butorphanol. The hemodynamic effects of butorphanol, a potent synthetic narcotic-antagonist analgesic, were investigated and compared with those of morphine. A total of 20 patients were studied (8 butorphanol, 12 morphine) at the time of diagnostic cardiac catheterization. Butorphanol decreased pH, PCO2, and systemic artery pressure and increased PCO2, cardiac index, and pulmonary artery pressure. Morphine caused similar changes in pH, PO2, systemic artery pressure, and PCO2 but much smaller changes in cardiac index and no change in pulmonary artery pressure. The clinical implications and possible mechanisms are discussed.


Disposition of meperidine in pregnancy.

Disposition of meperidine in pregnancy. Plasma concentration-time profiles of meperidine after intravenous administration to 7 pregnant women during labor were investigated. There was considerable interpatient variation in initial plasma concentrations of meperidine and its volume of distribution. When the data in the literature on the disposition of meperidine in nonpregnant subjects were used for comparison, it was found that the initial dilution volume (V1), the volume of distribution at steady-state (Vss), and the apparent volume of distribution during the terminal exponential phase of drug elimination (Vbeta) were less (p less than 0.05) in pregnant subjects than in healthy nonpregnant control subjects but were not significantly different in pregnant subjects and nonpregnant surgical patients. Mean total systemic blood clearance was also significantly less in the pregnant subjects (843 ml/min) than previously reported for healthy nonpregnant control subjects (1,465 ml/min). The blood/plasma concentration ratio of meperidine in pregnant women (0.940) was higher than that in control subjects (0.768; p less than 0.01). Placental transfer of meperidine was investigated in 4 of the patients; in 2 the concentration of the drug was greater in cord plasma than in maternal plasma. Further study is indicated.


Studies on theobromine disposition in normal subjects. Alterations induced by dietary abstention from or exposure to methylxanthines. Normal male volunteers on xanthine-restricted diets had a plasma theobromine (TB) half-life (t1/2) of 6.1 +/- 0.7 hr (mean +/- SEM), a TB metabolic clearance rate (MCR) of 113.8 +/- 6.8 ml/min (mean +/- SEM), and an apparent volume of distribution (aVd) of 59.9 +/- 7.8 L (mean +/- SEM) after a single oral dose of 6 mg/kg of TB. A two-week period of dietary abstention from methylxanthines shortened the mean plasma TB t1/2 by 33% and increased the mean MCR of TB by 59%, no change occurred in mean aVd of TB. In another experiment, normal male volunteers received the same oral dose of TB for each of five consecutive days. The mean plasma TB t1/2 measured immediately after the last TB dose was prolonged by almost two-thirds, while the mean aVd increased 23%. Although the mean plasma TB t1/2 measured four days after this last TB dose was the same as that measured after a single oral dose, the mean MCR of TB increased by 34%, but this change was balanced by increased mean aVd of 35%. These results suggest that immediately after five daily doses of TB, an impairment of TB clearance occurs that is reversible by four days of dietary abstention from methylxanthines.


High plasma nortriptyline levels in the treatment of depression. I. Following a 3-day single-dose kinetic study, 21 moderate to severely depressed inpatients were treated with 100 mg of nortriptyline nightly. Eighteen patients completed the 4-wk trial. The severity of depression was measured by weekly Hamilton Rating Scale and global rating. Blood for plasma nortriptyline estimation was taken at weekly intervals 12 h following the nighttime dose. There was a 6-fold variation in mean plasma nortriptyline levels, ranging from 120 microgram/L to 681 microgram/L. Patients with high plasma levels (greater than 200 microgram/L) showed significantly poorer clinical responses than those with levels in routine treatment, high plasma nortriptyline levels are significantly less effective than intermediate levels. Single-dose pharmacokinetic data obtained on the same patients showed a highly significant correlation with mean steady-state plasma levels obtained, which themselves correlated with clinical response. The value of predicting high plasma nortriptyline levels which are associated with poor response is discussed.


Effect of a standard breakfast on digoxin absorption in normal subjects. The influence of food on absorption of digoxin was studied in 6 healthy volunteers who received 1.0 mg digoxin as 4 tablets of Lanoxin either after an overnight fast, immediately after a standard breakfast, or 90 min after a standard breakfast. There was no significant difference between the three regimens in terms of area under the plasma concentration-time curve for 79 hr or in the 10-day cumulative urinary excretion. The mean peak plasma concentration was higher (p less than 0.05) when digoxin was given fasting (4.2 +/- 0.46 ng/ml) than immediately after food (2.8 +/- 0.24 ng/ml). The mean peak plasma concentration when digoxin was administered 90 min after food (3.3 +/- 0.30 ng/ml) was intermediate but not significantly different from either of the other mean peak concentrations. The results demonstrate that ingestion of food decreases rate but not extent of absorption of concurrently administered digoxin.


Kinetics of carbamazepine and carbamazepine-epoxide, determined by use of plasma and saliva. The concentration-time curves of carbamazepine (CBZ) and its metabolite (carbamazepine-10,11-epoxide; CBZ-epoxide) were determined in patients undergoing long-term antiepileptic drug treatment with the use of plasma and saliva data. Plasma and saliva samples were assayed concurrently for each patient by liquid chromatography. There was excellent linear correlation between CBZ levels in saliva and plasma (r = 0.991, p less than 0.001) over a large concentration range. The saliva/plasma ratio for CBZ concentration was 0.26 +/- 0.01 (SD). Since CBZ binding to plasma proteins is in the order of 76%, saliva CBZ concentration seems to reflect the unbound fraction of the drug in plasma. CBZ-epoxide has not been detected in saliva. The pharmacokinetic parameters of CBZ-epoxide were determined in 6 patients. The pharmacokinetic parameters of CBZ obtained from saliva concentrations were in excellent agreement with those obtained from plasma concentrations. Thus, CBZ determination in saliva is convenient for controlling blood levels in patients as well as for studying pharmacokinetics. The half-life, the relative body clearance of CBZ, and the metabolite concentration during steady-state, expressed as percent the parent compound, appear to be significantly different in patients on single and combined drug therapy.


Fluoride bioavailability after intravenous and oral administration: importance of renal clearance and urine flow. Fluoride (3 mg) was administered as a continous intravenous infusion during 30 min to 6 healthy subjects. Plasma concentrations and urinary excretion of fluoride in these experiments were compared with those obtained following oral administration of 2.82 mg, 4.50 mg, 5.64 mg, and 9.40 mg in the form of tablets and capsules. There were large day-to-day variations in the renal clearance of fluoride. This was shown to be due to differences in the urinary flow, an increase in flow causing an increase in renal clearance. The mean value of renal clearance from all experiments was 66.2 +/- 27.8 (SD; n = 16) ml/min. The extrarenal clearance, suggested to represent mainly the clearance to the bone pool, showed less interindividual variation: mean 110.3 +/- 32.3 (SD; n = 6) ml/min; the fraction remaining in the bone pool was highly consistent: 0.579 +/- 0.049 (SD; n = 6). When apparrent bioavailability was calculated from plasma and from urinary data, there was a great intra- and intersubject variation, as well as poor agreement between the two methods of calculations. This was found to be due to the day-to-day variation in renal clearance, which, in turn, varied with urinary flow. By use of equations that corrected for these variations, it was found that the bioavailability of sodium fluoride tablets is approximately 100%.


Phenobarbital pharmacokinetics in neonates. Phenobarbital pharmacokinetics after intravenous injection were studied in 8 neonates with seizures. Subjects ranged in gestational age from 30 to 40 wk. Plasma concentrations of phenobarbital were measured by enzyme-multiplied immunoassay (EMIT). The volume of distribution (Vd) of phenobarbital was 0.97 +/- .15 L/kg which was independent of the dose administered. Vd and gestational age did not correlate. Phenobarbital clearance calculated from average concentrations in patients maintained on phenobarbital for 1 to 4 wks was consistent, with a decrease in t1/2 from 115 hr after 1 wk to 67 hr after 4 wk of therapy. The elimination of phenobarbital decreased at an exponential rate with a t1/2 of 4.6 days. A pharmacokinetic model with an exponentially increasing elimination rate term was used to describe the data. Average concentrations predicted with the use of the model corresponded adequately with experimental results. The increases in clearance observed are thought to be related to rates of turnover of drug-metabolizing enzymes in the neonate.


Hemoperfusion for methotrexate removal.

Hemoperfusion for methotrexate removal. Removal of methotrexate by Amberlite XAD-4 hemoperfusion was determined in a patient with metastatic breast carcinoma. During 4 hr of hemoperfusion the plasma concentration of methotrexate fell from 5.5 x 10(-7) M TO 3.1 x 10(-7) M. After hemoperfusion methotrexate concentration increased as a consequence of multicompartmental pharmacokinetics to 5.5 x 10(-7) M and then slowly declined. Plasma methotrexate clearance decreased from 79 ml/min 30 min into hemoperfusion to 28 ml/min at the conclusion. In vitro clearance of methotrexate by 17 artificial kidneys, Amberlite XAD-4, and uncoated charcoal was determined. Uncoated charcoal had the greatest clearance of methotrexate of all the devices tested. We conclude that: (1) Amberlite XAD-4 transiently reduces plasma methotrexate concentration; (2) in vitro, charcoal hemoperfusion is more effective than XAD-4 in removing methotrexate; (3) as a consequence of the multicompartmental pharmacokinetics of methotrexate a postperfusion rebound in plasma methotrexate concentration is to be expected.


Gentamicin binding to serum and plasma proteins. Gentamicin binding to serum proteins was studied by equilibrium dialysis at 37 degrees C and pH 7.4 in the presence of both physiologic and adjusted concentrations of ionized calcium and magnesium. The percentage of bound drug was inversely related to the concentration of these two divalent cations, raning from 27% bound with no calcium and magnesium present to 17% bound in the presence of four times physiologic concentrations. No significant difference in the extent of drug-protein binding was noted in a comparison of sera from healthy and uremic subjects. Heparin also was found to affect gentamicin binding. Increasing heparin concentration in serum increased apparent gentamicin-protein binding to 34% in the presence of physiologic amounts of calcium and magnesium. Buffered heparin solutions without plasma proteins bound up to 65% of total drug concentration. Gentamicin-protein binding may have implications regarding pharmacokinetics and renal cortical uptake.


[Transcutaneous PO2 measurement in postoperative monitoring following thoracic surgery]. Continuous transcutaneous PO2 measurement controlling the arterial PO2 was performed in 40 patients undergoing thoracotomy. The close correlation between the PO2 levels measured transcutaneously and those found in the capillary blood prove that the method is very suitable for monitoring the postoperative course after thoracotomy. Postoperative PO2 values with and without the administration of increasing amounts of oxygen showed great variations in the patients' response to oxygen, thus emphasizing the need for continuous monitoring of the arterial PO2 values. This continuous PO2 measurement gives an indication of the possible need for the application of oxygen, and controls the effectiveness of oxygen therapy.


[Colon dynamics in ileus].

[Colon dynamics in ileus]. All forms of ileus have one thing in common, namely a disorder of the intestinal motility, which, with increasing distension of the intestinal wall, finally leads to paralysis of the intestine. With the increase in distension mechanical and functional colon changes take place which are discussed in this study. During peristalsis the strain on the wall is directed against the intra-luminal course of pressure. In spite of the increase of the internal pressure from 5 cm H2O to 100 cm H2O, the tension of the wall remains low or even decreases (roughly 500 dyn/mm2). In ileus patients, however, the strain on the intestinal wall increases enormously (about 100000 dyn/mm2). The maximum contraction capacity of the large intestine's muscle system (50,000 dyn/mm2) is high and similar to that of the skeletal muscles.


[Manometric studies of the anal canal in chronic primary fissure before and after management using dilatation or sphincterotomy]. Manometric investigations in patients with primary chronic fissure in ano were performed before and after stretching or sphincterotomy in a randomized clinical trial. Length of the functional anal canal was not influenced by the procedures. At a six-month follow-up, the maximum resting anal pressure was significantly lower in both groups. After stretching and sphincterotomy, the site of maximum pressure in the anal canal had moved orally. This demonstrates that an elevated resting anal pressure is one of the pathogenetic mechanisms for the development of a primary chronic fissure. It is successfully cut off by either stretching or sphincterotomy.


[Haemodialysis in the treatment of biguanide-induced lactate acidosis (author's transl)]. Severe lactate acidosis developed in nine diabetics on biguanide. When lactate acidosis was diagnosed all patients had reduced renal function, six being oligoanuric. Pre-existing chronic renal failure as a factor in the development of lactic acidosis was excluded in five patients, normal renal function being restored later. All patients were dialysed, seven surviving. This mortality rate is lower than that reported by others for biguanide-induced lactate acidosis. Rapid biguanide elimination by dialysis was demonstrated both in vitro and in vivo. The in vivo clearance of buformin was 83 +/- 43 ml/min (mean +/- SD, n = 4), that of phenformin 68 +/- 33 ml/min (n = 7). The main advantages of haemodialysis in the treatment of biguanide-induced lactic acidosis are rapid removal of toxic biguanides and excess lactate and the ability to administer sodium bicarbonate adequately without risking hypernatraemia and fluid overload.


[Brachial plexus paralysis after stellate blockade and plexus anaesthesia (author's transl)]. Brachial plexus paralysis is a serious complication of stellate blockade (n = 2) and plexus anaesthesia (n = 6) as was observed in 8 patients. It is frequently characterised by localised motor and sensory defects in the affected arm and sometimes accompanied by a causalgia-like pain. Pathogenetically mechanical factors--needle trauma, injection pressure, volume, and velocity--are of decisive importance. Prophylactically intraneural injections must be avoided. The electrifying pain during insertion of the needle and (or) immediate anaesthetic effect require correction of needle position.


[On heavy-metal poisoning, especially by thallium (author's transl)]. Only thallium poisoning is still of clinical significance among heavy-metal intoxications. Among 1800 cases of poisoning there were 15 caused by thallium, 3 by lead and 1 by iron (none by arsenic or mercury). Among thallium poisonings, 13 were due to suicide, one ending fatally, and two of homicide. Thallium can be demonstrated in urine even after haemodialysis and forced diuresis. As more and more rat poisons contain coumarine derivatives instead of thallium, the number of cases of thallium poisoning is likely to decrease.


[Management of treatment-resistant depression (author's transl)]. An intensive course of drug treatment--combination of a major tranquilliser with two antidepressants--was used in 46 patients with endogenous depression and 31 with exhaustion depression, all of which had proved refractory to other forms of treatment. After one week intramuscular injection of the major tranquilliser, in order to relax the patient, intravenous infusion of the two antidepressants, clomipramine and maprotiline, was performed daily for 10-20 days, while the major tranquilliser was given orally during this period. Complete remission after 4-6 weeks was achieved in 70% of patients with endogenous depression and 48% with exhaustive depression. It is stressed that careful diagnosis and treatment by drug and psychotherapy are preconditions for the successful management of otherwise resistant depressions.