The ‘Spitzenkörper’, centre of the reducing power in the growing hyphal apices of two septomycetous fungi

Summary Redox dyes, such as methylene blue and neutral red, are stably reduced to their leucobase in the Spritzenkörper of the growing hyphal tips ofNeurospora crassa andMonilia fructigena.We acknowledge the support of the Fonds National Suisse de la Recherche Scientifique and thank both Mrs Ton-That for her electron micrograph and Miss E. Herz for her technical help.     

Modulation of an ‘equilibrium enzyme’: Ecological evidence

Summary The activity of D-lactate dehydrogenase in the foot of the snail,Helix pomatia, is closely correlated with time of year and mean daily temperature, and increases strikingly after the animals have been exposed to a nitrogen atmosphere for 24 h.I thank U. Platzer for technical assistance and D. Frank for help with the statistics. The investigation was supported by the Fonds zur Förderung der wissenschaftlichen Forschung in Österreich, project No. 1257 and 2919.     

Serum iron level of the common Indian frogRana tigrina Daud.

Summary A study extending over a period of 2 years has been made on serum iron level of common Indian frogR. tigrina. Serum iron averages 99.4 g/100 ml in female and 92.60 g/100 ml in males. The serum iron concentration is relatively high from May to October. Starvation has been found to decrease the serum iron level from the 16th day onwards.Acknowledgment. Thanks are due to Professor Dr M. M. Goil, Head of the Zoology Department for guidance and help in various ways and to Professor Dr R. K. Sharma for valuable suggestions.     

Effects of oestrogen and progesterone on rat pineal N-acetyl transferase activity and melatonin production

Summary We have extended previous studies on pineal -receptors to include effects of oestradiol or PMSG treatment in the immature female rat. Neither manipulation has any effect on norepinephrine-induced N-acetyl transferase (NAT) activity in vitro. In the adult ovariectomised rat oestrogen/progesterone priming exerts a small sensitising effect to -stimulation with isoproterenol. Progesterone alone, in vitro, inhibits the release of melatonin from pineals of adult ovariectomised rats.The authors are grateful to J. Bradtke, D. de Ziegler and K.B. Ruf for their help, and to the Swiss National Science Foundation and to the Fonds Emil Barrell for financial support.     

A method for the isolation of ommochrome-containing granules from insect eyes

Summary A routine method for the preparation of pigment granules from insect eyes is reported. When viewed using an electron microscope, the isolated granules appear to be free from different structural elements, and there is very little contamination by membranous material. Ultrastructure and extinction spectra correspond to those found in situ.Acknowledgments. We thank Prof. Dr A. Fischer and Dr J. Rosenberg for their help in electron microscopic techniques. This work was supported by the Deutsche Forschungsgemeinschaft.     

The attenuation of prostaglandin-induced luteolysis in decidual tissue-bearing pseudopregnant rats

Summary Decidual tissue (DT)-bearing pseudopregnant (PSP) rats, in contrast to hysterectomized PSP rats, were resistant to a luteolytic regimen of either PGF₂ or PGE₂ when examined for the duration of PSP diestrus. The PG treatments, however, caused a marked fall in the serum progesterone levels on days 10 and 12, although the levels in DT-bearing rats on day 10 were significantly higher than in the hysterectomized rats.Acknowledgment. The authors wish to thank Helen Wilk and Edward Butler for their help in animal care; Ellen O'Laughlin-Phillips for the progesterone assays; Rosa Garnett, Jo Fletcher, and Aileen Svaty for editorial and secretarial help; Dr John E. Pike of the Upjohn Company for the gifts of PGE₂ and PGF₂; and Dr G. N. Niswender for the gift of antiserum GDN-337 used in the RIA for progesterone.Aided in part by NIH Training Grant HD-00024, Ford Foundation Grant 670-0135A, and NIH Program Project HD-07640.     

Acid excretion in young and adult Wistar Kyoto and spontaneously hypertensive rats

Summary Wistar Kyoto rats (WKy), the most widely accepted control for SH rats, show an inability to excrete acid appropriately when compared to another normotensive strain, SD. Coupled with the fact that KWy also develops sodium-sensitive hypertension, this makes them a more complex control than realized. At very young ages (<10-week-old), neither SH nor WKy show any deficiency in acid excretion.Acknowledgments. Supported by AHA grant 76 1019 and NIH grant AM 15458. The excellent secretarial help of Susan Dreux and Betty Mendelson is acknowledged.     

Tetrapyrrole biosynthesis from 4,5-dioxovaleric acid inRhodopseudomonas spheroides

Summary Porphyrin biosynthesis from 4,5-dioxovaleric acid was studied in cell suspensions ofR. spheroides. The experiments show that 4,5-dioxovaleric acid is a far precursor of porphyrins through amino laevulinic acid formation in a transamination reaction involving also 1-alanine. It differs radically from the classical aminolaevulinic acid synthesis using glycine and succinyl CoA as substrates.Acknowledgments: The authors are indebted to Dr Rodolfo García for helpful discussions and criticisms. Special thanks are given to Dr Aldo Mitta and other members of the Comisión Nacional de la Energía Atómica for their continuous help and support and for using their facilities in order to synthetise DVA.     

Pregnancy specificβ 1 — a product of the syncytiotrophoblast

Summary Pregnancy specific ₁ (PSG) has been identified in vitro in trophoblast cultures and in vivo, using transmission electron microscopy, in the syncytiotrophoblast, PSG may, like other pregnancy proteins, have immunosuppressive properties.This study was supported by a grant from the Medical Research Council. We thank Dr.D. R. Abramovich for making available the first trimester placentae and MissWanda Emslie for help in the tissue culture studies.     

The critical rotation of gravitating degenerate cylinders

Summary The dependence of critical rotational parameter = ²/2G_a on the parameter y ₀ ^–2 has been found for degenerate cylinders with the help of Padé approximations technique.     

Physical aspects of biophotons

Summary By comparing the theoretically expected results of photon emission from a chaotic (thermal) field and those of an ordered (fully coherent) field with the actual experimental data, one finds ample indications for the hypothesis that biophotons originate from a coherent field occurring within living tissues. A direct proof may be seen in the hyperbolic relaxation dynamics of spectral delayed luminescence under ergodic conditions.A possible mechanism has to be founded on Einstein's balance equation and, under stationary conditions, on energy conservation including a photochemical potential. It is shown that the considered equations deliver, besides the thermal equilibrium, a conditionally stable region far away from equilibrium, which can help to describe both biophoton emission and biological regulation.     

A negative inotropic effect of acetylcholine in the presence of several phosphodiesterase inhibitors

Summary The phosphodiesterase inhibitors papaverine, theophylline and 3-isobutyl-1-methylxanthine (IBMX) reveal a negative inotropic effect of acetylcholine in cat ventricular heart muscle. This effect is unrelated to -adrenoceptor stimulation and possibly mediated by the accumulation of cyclic GMP.I thank Mrs Petra Lauck for help. This work was supported by the Deutsche Forschungsgemeinschaft.     

Wound healing properties of naphthaquinone pigments fromAlkanna tinctoria

Summary From the roots ofAlkanna tinctoria Tausch, the alkannin esters of the following acids were isolated and identified: ,-dimethylacrylic acid, -acetoxy-isovaleric acid, isovaleric acid, and angelic acid. These esteric pigments showed excellent wound healing properties in a clinical study on 72 patients with ulcus cruris.I thank Dr A. Winkler, Heidberg Hospital and Prof. K. Kanitakis, Aristotle University, for the clinical studies. Prof. A. Sagredos, Aristotle University, for his help and Dr C. Gairola, Tobacco and Health Research Institute, for the mutagenicity tests. I also thank Dr G. A. Digenis and Dr L. Hurley, University of Kentucky, College of Pharmacy, for their critical reviews and comments.     

α-andβ-activity of O-methylated derivatives of norepinephrine and epinephrine

Summary Metanephrine, iso-metanephrine, normetanephrine and isonormetanephrine were tested for - and -activity on various tissues obtained from rats, guinea-pigs and cats. It was found that methylation of the hydroxyl groups of norepinephrine or epinephrine in either the 3-or 4-position markedly reduces or abolishes -and -activity with the exception of the nictitating membrane of the cat. This receptor seems to show a tissue difference.Acknowledgment. W. H. V. would like to thank the Federal Republik of Germany for the U. S. Senior Scientist Award which enabled him to work at the Department of Pharmacology, University of Mainz, and to conduct part of this work. W. H. V. would also like to thank Prof. Dr E. Muscholl, Mainz, for his hospitality, help and advice during this stay.     

Inhibition of steroidogenic activity in the adrenal cortex of rats fed benzene hexachloride (hexachlorocyclohexane)

Summary Feeding various dosages of benzene hexachloride (100, 250, 750 and 1500 ppm) in the diet to weanling male albino rats for 90 days resulted in marked hypertrophy of the adrenals with large, vacuolated cells in the cortex at 750 and 1500 ppm. Accumulation of cholesterol-positive lipids and marked reduction in the activities of steroidogenic enzymes such as ⁵ 3 HSDH, 11 HSDH, G-6-PDH and SDH were seen using histochemical methods in the adrenal cortex of rats fed 750 and 1500 ppm. The results are suggestive of steroidogenic inhibition at 750 and 1500 ppm of dietary BHC while 100 and 250 ppm did not produce any discernible changes in the adrenal cortex.Acknowledgments. The authors thank Dr Muralidhara, H.P. Ramesh and K. Nanjundiah for their help and Prof. H.B. Devaraj Sarkar, Department of Zoology, University of Mysore, for providing us facilities for histochemical work. We are grateful to Sri C.P. Natarajan, for his keen interest in this investigation.     

Unraveling the pathogenesis of Parkinson’s disease – the contribution of monogenic forms

The field of Parkinsons disease pathogenesis is rapidly evolving from the one of a monolithic and obscure entity into the one of a complex scenario with several known molecular players. The ongoing systematic exploration of the genome holds great promise for the identification of the genetic factors conferring susceptibility to the common non-Mendelian forms of this disease. However, most of the progress of the last 5 years has come from the successful mapping and cloning of genes responsible for rare Mendelian variants of Parkinsons disease. These discoveries are providing tremendous help in understanding the molecular mechanisms of this devastating disease. Here we review the genetics of the monogenic forms of Parkinsons disease. Moreover, we focus on the mechanisms of disease caused by -synuclein and parkin mutations, and the implications of this growing body of knowledge for understanding the pathogenesis of the common forms of the disease. Received 10 March 2004; received after revision 26 April 2004; accepted 29 April 2004     

Structural aspects of Golgi function

Since its discovery, the Golgi complex has attracted the attention of cell biologists because of its fashionable morphology and central position within the secretory system of the cell. Here, we discuss how the three-dimensional architecture of the Golgi complex relates to its multiple functions in protein sorting and processing, and how an analysis of the morphology of the Golgi complex can help to provide an understanding of the mechanisms involved in transport through this unique organelle.     

A presynaptic effect of whole venom ofDendroaspis jamesoni on the hemidiaphragm of rat

Summary Dendroaspis jamesoni venom in a dose of 12.5 g/ml restricts the uptake of Ca⁺ leading to inhibition of release of Ach from the motor nerve terminals of the hemidiaphragms of rats.Acknowledgment. University of Nairobi, for the research grant (No. 670-052), which supported this work. We also thank Mr. S. K. Githaiga, Government Chemist's Department, for his help in the use of the spectrophotometer.     

How gill surface ofSaccobranchus fossilis facilitates active gas exchange?

Summary The surface morphology of fish gill has been studied by scanning electron microscopy. The surface of gill epithelium shows a pseudoconcentric arrangement of arborizing ridges and channels. Further, at places on gill filaments the surface shows several infoldings labelled as micropits. The role of these morphological adaptations has been correlated with the gas exchange physiology.The author is deeply indebted to Prof.M. Nishiura, Dr.S. Izumi and Mr.O. Fuse for their kind suggestions and help, and to Prof.H. B. Tewari for encouragement. VKR would like to thank Japan Leprosy Mission for excellent facilities.