Effects of surgically induced instability on rat knee articular cartilage

Degenerative lesions in the articular cartilage were present following transection of the anterior cruciate ligament in the rat. These lesions included surface disruptions, a reduction in matrix proteoglycans, and cellular changes and therefore were similar to lesions seen in dogs following transection of the anterior cruciate ligament as well as lesions seen in other mechanical derangement models. Lesions were more frequently encountered in animals that had been exercised on a treadmill. This suggests that the rat knee joint may be a useful small animal model in studying the effect of mechanical derangement on articular tissues.

Sympathetic innervation of murine thymus and spleen: a comparative histofluorescence study

Fluorescence microscopy of thymus and spleen from four strains of mice (C3H and ICR controls, AKR spontaneously leukemic and NZB autoimmune) revealed varicose noradrenergic (NE) fibers in perivascular and parenchymal regions of both organs. Thymic innervation was largely perivascular, but isolated islands and strings of free NE fibers were noted among thymic parenchymal cells. A morphological proximity between NE fibers in the thymus and mast cells was noted in all strains studied, but was exceptionally prominent in the NZB thymus. Perivascular plexuses within the splenic white pulp sent single NE fibers between the surrounding lymphocytes. Catecholamines and histamine have been shown to modulate lymphocyte development and activity in vitro. The present study provides morphological evidence that both NE and histamine are available to lymphocytes in thymus and spleen, and thus provides morphological evidence for neural modulation of immune activity in vivo.

Alkyl-metal and aryl-metal bond chemistry in coordinately unsaturated polynuclear metal complexes

A new class of coordinately unsaturated polynuclear rhodium and iridium alkyl, benzyl, and aryl derivatives of the form [RM(1,5-cyclooctadiene)](x) have been prepared by the reaction of the organolithium reagent with the cyclooctadienemetal chlorides at -78 degrees C. The x-ray crystal structure of [mu-CH(3)Rh (1,5-cyclooctadiene)](2) is reported. The analogous iridium dimer decomposes by an initial sequence of alpha-hydrogen abstraction and then reductive elimination of hydrogen to give [mu-CH(2)Ir(1,5-cyclooctadiene)](2). Formed in high yield by the decomposition of the ethylrhodium complex was [HRh(C(8)H(11))](4), a tetrahedral cluster with face-bridging hydride ligands. Also discussed are the reactivities of the benzyl and phenyl derivatives. Unique reaction pathways for C-H bond activation and scission in this chemistry are delineated.

Structure and chemistry of a metal cluster with a four-coordinate carbide carbon atom

Molecular metal clusters with carbide carbon atoms of low coordination number have been prepared; they are the anionic [HFe(4)C(CO)(12) (-)] and [Fe(4)C(CO)(12) (2-)] clusters. An x-ray crystallographic analysis of a tetraaminozinc salt of the latter has established a butterfly array of iron atoms with the carbide carbon atom centered above the wings of the Fe(4) core. Each iron atom was bonded to three peripheral carbonyl ligands. The distances from the carbide carbon to iron were relatively short, particularly those to the apical iron atoms (1.80 A average). Protonation of the anionic carbide clusters reversibly yielded HFe(4)(CH)(CO)(12), and methylation of the dianion gave {Fe(4)[CC(O)CH(3)](CO)(12) (-)}. Oxidation of [Fe(4)C(CO)(12) (2-)] yielded the coordinately unsaturated Fe(4)C(CO)(12) cluster, which was extremely reactive. Hydrogen addition to this iron cluster was rapid below 0 degrees C, and a C-H bond was formed in this transformation.

Canine parainfluenza-Bordetella bronchiseptica vaccine immunogenicity

The immunogenicity and safety of 3 serials of a canine parainfluenza (CPI) virus-Bordetella bronchiseptica vaccine was evaluated. Each serial was used to vaccinate 10 dogs with single doses given intranasally. The 30 vaccinated and 10 nonvaccinated controls dogs were challenge exposed with aerosols of virulent CPI virus and B bronchiseptica at 18 days and at 21 days, respectively, after vaccination. After challenge exposure, none of the 30 vaccinated dogs had clinical signs of disease; however, 9 of the 10 nonvaccinated dogs developed coughing problems. The CPI virus was isolated from nasal swab specimens obtained from nonvaccinated dogs on an average of 5.1 days after challenge exposure, but was not isolated from any of the specimens obtained from the vaccinated dogs. Bordetella bronchiseptica was isolated from nasal swab specimens obtained from both vaccinated and nonvaccinated dogs up to 18 days after challenge exposure. The erythrocyte sedimentation rates and total leukocyte counts for control dogs were generally increased, in contrast to those for the vaccinated groups. Dogs showed a primary serologic response to CPI virus and B bronchiseptica after vaccination and an anamnestic response to the bacterium after challenge exposure. Adverse local or systemic reactions attributable to the bivalent vaccine were not observed in the vaccinated dogs.

Sympathetic innervation of murine thymus and spleen: evidence for a functional link between the nervous and immune systems

Sympathetic innervation was demonstrated in both perivascular and parenchymal regions of murine thymus and spleen. Catecholamine varicosities were associated with mast cells in these areas. The antibody response to sheep red blood cells of 7 week old mice that had been sympathectomized with six-hydroxydopamine (6OHDA) at birth was significantly elevated compared with saline treated controls. Alpha-methyl tyrosine (alpha-MT) and 6OHDA treatment of mice, producing a more complete sympathectomy, showed a significantly enhanced anti-SRBC response with respect to mice treated with alpha-MT or 6OHDA alone. Catecholamine levels in thymus, spleen, and adrenals of both experimental and control mice were measured using liquid chromatography with electrochemical detection (LCEC). The present study suggests that the sympathetic nervous system has a functional role in modulating the humoral immune response in vivo.

Anthropometric measurements of 3-, 4-, 5-, and 6-year-old girls and boys

This study examined the physical size and subcutaneous body fat of 269 Caucasian boys and girls, ages 3, 4, 5, and 6. In addition to height, weight, and leg length, the measurements included seven diameter, eight circumference, and five skinfold measurements. The means and standard deviations for all anthropometric measurements are presented. When compared by age group, the children were significantly different (p < .01) on all physical size measurements, but not on the skinfold measurements. When the measurements were analyzed to determine significant sex differences, it was evident that, where differences existed, the boys' physical size measurements were larger than the girls', while on the other hand, the girls had a greater amount of subcutaneous body fat than did the boys. The anthropometric data reported in this study did not support the secular trend phenomenon, but substantiated the contention that between three and six years of age, the triceps skinfold measurement declines gradually for boys and remains stable for girls. In summary, it is imperative that anthropometric measurement standards be continually revised and kept current, and that when possible, children be individually evaluated for classification into groups and not classified solely on the basis of age and sex.

Left atrial isolation: new technique for the treatment of supraventricular arrhythmias

Surgical management of refractory ectopic supraventricular tachycardia arising in the left atrium requires cryoablation of the bundle of His and insertion of a permanent ventricular pacemaker. This study was designed to develop a technique to isolate the left atrium electrically from the remainder of the heart, so that an artificial pacemaking system would be unnecessary. Ten adult dogs were subjected to cardiopulmonary bypass and a standard left atriotomy was extended anteriorly across the mitral valve anulus between the right and left fibrous trigones. Posteriorly, the atriotomy was extended across the mitral valve anulus just to the left of the posterior crux and interatrial septum. The muscular interatrial fibers accompanying the coronary sinus were cryoablated at -60 degrees C for 2 minutes. Postoperatively, all animals remained in normal sinus rhythm. Rapid left atrial pacing did not affect the rate or rhythm of the remainder of the heart. Preliminary hemodynamic measurements suggest that loss of the synchronous left atrial "kick" does not significantly affect left ventricular preload, afterload, or cardiac output. This technique offers an alternative to the current surgical approach for management of refractory ectopic supraventricular tachycardia arising in the left atrium.

Speech rate as a measure of short-term variation in depression

Experimental investigation of the state of depression is at present hindered by the lack of simple, objective, repeatable measures of components of the state. Covariation between self-report measures of affect and simple measure of speech rate was investigated in a series of studies of both clinical and normal subjects, using single-case and group designs. Slowing of speech was significantly and substantially correlated with self-reports of increased unpleasant affect in certain situations. This suggests that the speech measure may usefully reflect a behavioural component of a state of retarded-type depression.

Distortions of vision and pain: two functional facets of D-lysergic acid diethylamide

D-lysergic acid diethylamide (LSD) produces distortions of visual perception and analgesia. Evidence is advanced from a functional standpoint that the observed visual effects result from an attenuation of light-evoked input to the dorsal lateral geniculate nucleus (LGN) from the purely centripetal pathways of the retina. More slowly responding visual afferents or those with more complex receptive fields seem to be affected most. LSD analgesia, accompanied by severe psychotic symptoms, appears to result from drug actions on a centrifugally controlled pain system involving neurons of the midbrain raphe.

Molecular Structure of an Unusual Organoactinide Hydride Complex Determined Solely by Neutron Diffraction

The structure of an unusual organometallic complex, {Th[(CH(3))(5)C(5)](2) H(micro-H)}(2) . C(6)H(5)CH(3), has been determined from neutron diffraction data, using only the direct-methods program MULTAN. Besides providing accurate metrical information on the first organometallic actinide hydride complex, these results have general and far-reaching implications concerning the complexity and size of crystal structures that can be elucidated solely on the basis of neutron diffraction data.

A Mossbauer determination of the iron core particle size distribution in ferritin

The important biological iron bearing molecule ferritin has been studied using the 57Fe Mossbauer resonance. Natural and reconstituted ferritin samples have been studied in the temperature range 4--300 K. At low temperatures six-line magnetic hyperfine spectra are observed but with noticeably asymmetric line shapes, at high temperatures doublets are observed and in an intermediate temperature range (30--40 K) complex spectra characteristic of superparamagnetic behaviour are observed. From a theoretical study of the dependence of the hyperfine splitting parameters on particle size and from the experimental probability distributions obtained for these parameters from the Mossbauer spectra, it has been possible to derive the ferritin micelle particle size distributions for four different samples. It is found that the natural and reconstituted samples have roughly similar distributions except for the sample reconstituted from apoferritin in the presence of a phosphate environment. This sample is shown to have a slightly narrower particle size distribution centred on a smaller mean diameter. The information derived from these Mossbauer measurements are finally shown to be consistent with conclusions reached from separate biochemical experiments.

Separation and Some Properties of Large and Small Amyloplasts throughout Development in Barley Endosperm

A method is described whereby amyloplasts from immature barley (Hordeum distichum L.) endosperm could be separated into two populations of large and small amyloplasts at all stages of development. The small amyloplasts had more amylopectin than the large at early stages, but by 60 days after anthesis, the large had the greater proportion of amylopectin. Starch synthetase activity was associated with both types of amyloplast. The nucleotide specificity of the starch synthetase associated with each population varied independently throughout development. At 25 days after anthesis, the large amyloplasts were more susceptible than the small to alpha-amylolysis; however, at 38 and 60 days, the small amyloplasts became more susceptible.

Osmotic factors of dehardening in cornus Florida L

The killing temperature for cortical cells from the flowering dogwood changes abruptly from -25 C to -15 C during dehardening. Cell sap concentration, minimum critical cell volume, and osmotically inactive cell volume show a progressive change during dehardening, but only cell sap concentration is correlated directly with the killing temperature, showing the same step change. There is a limit to the extent to which hardy dogwood cells can be osmotically reduced in volume. Beyond this limiting volume, the extracellular osmotically can be increased without further volume reduction. Ultimately the cell succumbs, presumably to an osmotic pressure gradient. Nonhardy cells do not exhibit this resistance to shrinkage. The ability to resist volume reduction is probably a crucial factor in the freezing resistance of dogwood cortical cells.

Ontogenetic dissociation of two classes of habituation

The rates of decrement of two classes of response (an elicited startle reflex and emitted exploratory behavior) were determined in rats of two different ages (15 and 36 days). The rate of decrement in the startle reflex was not clearly differentiated as a function of age. In contrast, there was no evidence of habituation of exploration in the younger animals, whereas the older rats uniformly showed profound response decrements. This ontogenetic dissociation of the two instances of response decrement indicates that accounts of both instances in terms of a common process called habituation may be unwarranted. In addition, these data, in conjunction with earlier findings, indirectly support the possibility that reflex decrements may be relatively more dependent on brain serotonin whereas decrements in exploration may be more dependent on normal cholinergic activity in brain.

Antiprismatic Coordination about Xenon: The Structure of Nitrosonium Octafluoroxenate(VI)

The structure of nitrosonium octafluoroxenate(VI), 2NOF . XeF(6), has been determined by means of single-crystal x-ray counter methods (R-index = 0.046, weighted R-index = 0.042). The space group is Pnma, with a = 8.914(10) angstroms, b = 5.945(10) angstroms, and c = 12.83(2) angstroms (the numbers in parentheses are the standard deviations to the least significant digit or digits); the calculated density (rho) is 3.354 grams per cubic centimeter, and there are four formula units per unit cell. The material consists of well-separated NO(+) and (XeF(8))(2-) ions; the structural formula is thus (NO)(2) (XeF(8)). The anion configuration is that of a slightly distorted Archimedean antiprism. The observed distortion appears incompatible with a lone-pair repulsion model. Xenon-fluorine bond lengths of 1.971(7), 1.946(5), 1.958(7), 2.052(5), and 2.099(5) angstroms were found.

Antigen in tissues. 3. The separation of antigen-containing components from lymphoid tissues

Particulate and soluble antigens were labelled with ¹²⁵I, injected into rats and the lymphoid organs examined. As determined by autoradiography of tissue sections, one antigen used localized exclusively in vacuoles of medullary macrophages of the lymph nodes and others on the surfaces of reticular cells in the lymphoid follicles of nodes or the white pulp of spleen. The remaining antigens studied localized in both medulla and lymphoid follicles of nodes. Tissues containing antigen were homogenized in a sucrose medium and most radioactivity was recovered in a large granule fraction. This fraction was submitted to equilibrium centrifugation. The preparations were not resolved in gradients of sucrose or dextran but in gradients of Urografin the preparations were resolved into two or more peaks of radioactivity. Medullary localized antigen banded in a region of the gradient rich in lysosomal enzymes and was considered to be present in vesicles. Antigen was not found in a region of the gradient rich in mitochondria. Antigen from lymphoid follicles of nodes or from spleen white pulp banded at high density values and was considered to be present as an antigen—antibody complex, possibly associated with membrane. Equilibrium density centrifugation in Urografin gradients provides a means of separating and examining the properties of antigen in lymphoid tissues.

Radio tracking of homing bats

Neotropical bats, Phyllostomas hastatus, were released 10 kilometers from their home roost, and their homeward flights were tracked by radio. Flights of bats with unimpeded vision were strongly oriented in the homeward direction, while the flights of blindfolded bats did not show this marked orientation.

A case of farmer's lung

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