Accessory cells in immune suppression. I. Role of I-A+ accessory cells in effector phase idiotype-specific suppression of myeloma function

The suppression of MOPC 315 myeloma cells by idiotype-specific effector Ts requires the presence of non-immune AC. This requirement was demonstrated in cultures where myeloma targets and Ts were separated by cell-impermeable membranes or were in direct contact. The AC were adherent, radioresistant, and present in peritoneal exudates and in FcR+ as well as FcR- fractions of low density splenocytes; they bore cell surface I-A determinants and did not have to be H-2 compatible with myeloma cells and Ts. These studies demonstrate a novel role for Ia+ AC in immune regulation, and suggest that their accessory function may involve processing of T lymphocyte-derived suppressor factors or presentation of such factors to target cells.     

Activation of HMG-CoA reductase by microsomal phosphatase

HMG-CoA reductase activity can be modulated by a reversible phosphorylation-dephosphorylation with the phosphorylated form of the enzyme being inactive and the dephosphorylated form, active. Phosphatases from diverse sources, including cytosol, have been shown to dephosphorylate and activate HMG-CoA reductase. The present study demonstrates phosphatase activity capable of activating HMG-CoA reductase that is associated with purified microsomes. The incubation of microsomes at 37 degrees C for 40 min results in a twofold stimulation of HMG-CoA reductase activity, and this stimulation is blocked by sodium fluoride or phosphate. The ability of microsomes to increase HMG-CoA reductase activity occurs regardless of whether microsomes are prepared by ultracentrifugation or calcium precipitation. Additionally, phosphatases capable of activating HMG-CoA reductase are present in both the smooth and rough endoplasmic reticulum. Freeze-thawing does not prevent microsomes from activating HMG-CoA reductase but preincubation results in a significant decrease in the ability of microsomes to increase HMG-CoA reductase activity. Thus, the present study demonstrates that purified liver microsomes contain phosphatase activity capable of activating HMG-CoA reductase.     

Ultrastructural studies of spermatogenesis in the anthocerotales. III. Gamete morphogenesis: From spermatogenous cell through midstage spermatid

An ultrastructural examination of spermatogenesis in Phaeoceros has shown nucleoli to be present in spermatogenous cells and to persist until the centrioles become associated with nuclei of young spermatids. At the onset of multilayered structure (MLS) formation, well-defined aggregations of osmiophilic strands begin to form in the nuclei of young spermatids and disappear shortly after chromatin condensation starts in the midstage spermatids. When the centrioles in the young spermatids are orientated perpendicular to the nuclear envelope, the nucleoplasm immediately in front of them is densely stained. Where the spline tubules of the MLS extend over the nucleus, the nuclear envelope is devoid of pores, and the inner nuclear membrane is contacted internally by the local deposition of dense staining nucleoplasm. Chromatin condensation begins with strands extending perpendicularly from the dense staining nucleoplasm beneath the spline and continues with the nuclear beak becoming filled with condensed chromatin. As the MLS lamellae disappear acropetally, the rear portion of the anterior mitochondrion (AM) extends back under the nuclear beak which now narrows to a size that approximates the anterior end of the nucleus of a spermatozoid. By the end of the mid-spermatid stage, the nucleus has coiled approximately one gyre of a helix and the five or six central slpine tubules extend over the plastid which is now located beneath the front end of the AM. Several profiles of endoplasmic reticulum confluent with the nuclear envelope are present. Possible factors which might play a role in determining the morphology of the mid-spermatids are discussed.     

Distribution of tritium in D-glucose and starch labeled by tritium-atom bombardment

Samples of D-glucose and starch were labeled by tritium-atom bombardment. Up to 51% incorporation into D-glucose as non-labile tritium was achieved for crystalline, anhydrous D-glucose and 41% for the amylose-butyl alcohol complex. Distribution of tritium in the carbon skeleton of D-glucose was calculated by comparing the specific molar activity of D-glucose with that of its derivatives. Derivatives prepared were D-gluconic acid, D-arabino-hexulose phenylosotriazole, 4-formyl-2-phenyltriazole, 2-phenyltriazole-4-carboxylic acid, D-arabino-hexulose phenylflavazole, 3-formyl-1-phenylflavazole, and formaldehyde dimedone. The tritium distribution showed definite structural effects. Generally, the products from films of D-glucose and the amylose-butyl alcohol complex had nearly uniform distribution of tritium in D-glucose. The product from crystalline α-D-glucose monohydrate had zero tritium at C-2 and twice the expected amount of tritium at C-5, and that from starch granules had zero or near zero tritium at C-3 and close to twice the expected amount of tritium at C-2.     

Biochemische,histologische und klinische Befunde bei einer vierjährigen Konduktorin der gutartigen X-chromosomalen Muskeldystrophie (Typ Becker)

Zusammenfassung Es wird über eine 4 Jahre alte Konduktorin der gutartigen progressiven Muskeldystrophie vom Typ Becker berichtet. Sie ist die Tochter eines hemizygot erkrankten Patienten aus einer Familie mit dem für diese Myopathie typischen X-chromosomal recessiven Erbgang. Die Patientin zeigt deutliche klinische Symptome einer Muskeldystrophie: generalisierte Hypotonie, Hyperlordose der Lendenwirbelsäule und Muskelatrophien im Bereich sowohl des Becken- als auch des Schultergürtels (scapulae alatae). Die höchste Aktivität der Serum-Creatinkinase übersteigt 300 IU. Das Elektromyogramm ist myopathisch, und die Muskelbiopsie läßt ein Muster von gesunden und dystrophen Fasern erkennen. Das Geschlechtschromatin ist positiv, und in einer Kultur von Blut-Lymphocyten findet sich durchwegs ein normaler weiblicher Karyotyp XX. Verschiedene mögliche Erklärungen für diese seltene Gen-Expressivität werden diskutiert. Am wahrscheinlichsten scheint ein Mißverhältnis in der Inaktivierung der X-Chromosome durch die frühembryonale Lyonisierung zu sein, so daß jetzt fast nur pathologische Allele genetisch aktiv sind.

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Biochemical, histological and clinical findings in a four-year-old female carrier of benign X-linked muscular dystrophy (Becker Type)

Summary A 4 year old femake carrier of benign progressive muscular dystrophy (Becker type) is described. She is a daughter of a hemizygous patient from a previously reported family with the typical X-linked recessive inheritance of this myopathy. The child shows marked myopathic symptoms, e.g. generalized muscular hypotonia, hyperlordosis of the lumbar spine and muscular atrophies of both pelvic and shoulder girdle (scapulae alatae). The highest activity of serum creatinekinase exceeds 300 IU. Electromyographic findings are myopathic and in a muscular biopsy a pattern of normal and dystrophic fibers has been found. Sex-chromatin is positive, and the child has a normal XX-karyotype in cultured blood lymphocytes. Several possible explanations for this rare gene expression are discussed. A very probable cause seems to be a disproportionate inactivation of the X-chromosomes by lyonization in early embryonic life, so that most of the pathological alleles in the striated muscles are now still genetically active.

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Direktor: Prof. Dr. med. E. Rossi     

Mating activities ofAtta texana (Hymenoptera,formicidæ)

Summary Alate broods are reared without worker broods in lower cavities of nests in winter, and with worker broods in upper cavities of nests in spring. Winged adults appear in early April, but swarming does not occur until late May. Flights issue yearly from most large nests. The alate sex ratio is about 11. Before swarming will occur, nest surfaces must be soaked with at least 7 mm of rain; flights continue as long as nests remain wet and temperatures exceed 16°.A circadian rhythm triggers swarming at about 355 a.m., and most alates leave the nest surface within 2 minutes. Fertilized females contain from 69 to 186 million spermatozoa. Seminal vesicles of males contain 65 to 130 million spermatozoa.

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Zusammenfassung Geflügelte Nachkommenschaft wird im Winter in den unteren Hohlräumen des Nests ohne die Brut der Arbeiterinnen aufgezogen und im Frühling mit der letzteren zusammen in den oberen Hohlräumen des Nests. Geflügelte erwachsene Ameisen earschienen Anfang April, schwärmten aber erst Ende Mai. Flüge fanden jährlich von den meisten grossen Nestern aus statt. Bie den geflügelten Individuen war das Verhältnis der Geschlechter 11. Vor dem Schwärmen war die Nestoberfläche mit mindestens 7 mm Niederschlag durchnässt worden; Flüge wurden fortgesetzt solange die Nester feucht waren und die Temperatur 16° C überschritt.Ein Tagesrhytmus löste das Schwärmen ungefähr um 3 Uhr 55 Minuten morgens aus, und die meisten geflügelten Ameisen verliessen die Nestoberfläche innerhalb von 2 Minuten. Befruchtete Weibchen enthielten zwischen 69 und 186 Millionen Spermatozoen; Samentasche der Männchen enthielten 65 bis 130 Millionen Samenzellen.

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Resumen (2) Durante el invierno, las creasas aladas son criadas en la ausencia de cresas trabajadoras en las cavidades inferiores de los nidos, pero durante la primavera, son criadas junto a creasas trabajadoras en las cavidades superiores de los nidos. Los adultos alados aparecen temprano en abril, pero los vuelos ocurren terde en mayo. Los sexos aparecen en proporció unitaria en los adultos alados. Los vuelos ocurren cuando las superficies de los nidos han sido humedecidas con 7 mm de agua y continúan ocurriendo mientras haya suficiente humedad y la temperature sobrepase 16° C.Los vuelos son iniciados por un ritmo diario y comienzan alrededor de las 355 A.M. La mayor parte de los adultos alados emprende vuelo en un término de 2 minutos. Las hembras fecundadas contienen de 69 à 186 millones de espermatozoides; las vesículas seminales de los machos contienen de 65 a 130 millones.

     

Unterschiedliche photoperiodische Empfindlichkeit der beiden Blattseiten von Kalanchoe blossfeldiana

Summary The short-day plant Kalanchoe blossfeldiana was grown on short photoperiods and was given supplementary light of low intensity (4–7 lux). If the supplementary light was supplied to the upper sides of the leaves flowering was strongly inhibited. Irradiation of the lower sides was much less effective.     

Effects of follicle-stimulating hormone on inhibin release by different testicular compartments in the adult ram.

The aim of this study was to determine the bidirectional release of immunoreactive inhibin-alpha (irINH-alpha) by different testicular compartments in the adult ram and to assess the effects of FSH on the distribution of inhibin in the testis. Immunoreactive INH-alpha was measured by RIA in fluid samples collected concurrently from the three testicular compartments--the seminiferous tubules, the interstitium, and the vascular system--through catheters inserted surgically into the rete testis, testicular lymphatic duct system, and spermatic veins, respectively. Overall, the concentration of irINH-alpha in rete testis fluid was 25 times the level in testicular lymph and over 500 times the concentration in peripheral blood. The pattern of irINH-alpha concentration in rete testis fluid was inversely related to that in testicular lymph, but i.v. administration of FSH had a decoupling effect on this relationship by depressing inhibin concentration in testicular lymph without affecting inhibin levels in rete testis fluid. Nevertheless, increased flow of testicular lymph more than compensated for the transient fall in irINH-alpha concentration so that, overall, the total output of inhibin via the testicular lymphatic duct system (and the vascular system) increased significantly. No persistent or significant changes were observed in the flow rate of rete testis fluid or concentration of irINH-alpha in the fluid after administration of FSH. The time frame for the response of the testis to FSH is indicative of the involvement of a mediator. Electrophoretic analysis of serially collected testicular lymph samples consistently revealed an FSH-induced release of a series of proteins in the M(r) range of 30,000-32,000.(ABSTRACT TRUNCATED AT 250 WORDS)     

Developmentally regulated expression of three slow isoforms of myosin heavy chain: diversity among the first fibers to form in avian muscle.

At least three slow myosin heavy chain (MHC) isoforms were expressed in skeletal muscles of the developing chicken hindlimb, and differential expression of these slow MHC isoforms produced distinct fiber types from the outset of skeletal muscle myogenesis. Immunohistochemistry with isoform-specific monoclonal antibodies demonstrated differences in MHC content among the fibers of the dorsal and ventral premuscle masses and distinctions among fibers before splitting of the premuscle masses into individual muscles (Hamburger and Hamilton Stage 25). Immunoblot analyses by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of myosin extracted from the hindlimb demonstrated the presence throughout development of different mobility classes of MHCs with epitopes associated with slow MHC isoforms. Immunopeptide mapping showed that one of the MHCs expressed in the embryonic limb was the same slow MHC isoform, slow MHC1 (SMHC1), that is expressed in adult slow muscles. SMHC1 was expressed in the dorsal and ventral premuscle masses, embryonic, fetal, and some neonatal and adult hindlimb muscles. In the embryo and fetus SMHC1 was expressed in future fast, as well as future slow muscles, whereas in the adult only the slow muscles retained expression of SMHC1. Those embryonic muscles destined in the adult to contain slow fibers or mixed fast/slow fibers not only expressed SMHC1, but also an additional slow MHC not previously described, designated as slow MHC3 (SMHC3). Slow MHC3 was shown by immunopeptide mapping to contain a slow MHC epitope (reactive with mAb S58) and to be structurally similar to a MHC expressed in the atria of the adult chicken heart. SMHC3 was designated as a slow MHC isoform because (i) it was expressed only in those muscles destined to be of the slow type in the adult, (ii) it was expressed only in primary fibers of muscles that subsequently are of the slow type, and (iii) it had an epitope demonstrated to be present on other slow, but not fast, isoforms of avian MHC. This study demonstrates that a difference in phenotype between fibers is established very early in the chicken embryo and is based on the fiber type-specific expression of three slow MHC isoforms.