A new wireless system for decentralised measurement of physiological parameters from shake flasks

Background  

Shake flasks are widely used because of their low price and simple handling. Many researcher are, however, not aware of the physiological consequences of oxygen limitation and substrate overflow metabolism that occur in shake flasks. Availability of a wireless measuring system brings the possibilities for quality control and design of cultivation conditions.     

Complementary developmental expression of the two tyrosine hydroxylase transcripts in zebrafish

Tyrosine hydroxylase (TH) is a rate-limiting enzyme in the biosynthesis of catecholamines. In zebrafish, two genes encoding TH have been identified. We cloned them and studied their expression in zebrafish. In adult tissues, th1 mRNA was more abundant than th2 mRNA in the brain and eyes, whereas th2 mRNA was more abundant in the liver, kidney, heart and gills. In developing brain, th1 mRNA was readily detected at 1 day post-fertilization using qPCR and in situ hybridization, whereas th2 mRNA appeared later. th1 was found in 17 catecholaminergic groups in larval brain, whereas th2 was found in four additional groups. A monoclonal antibody commonly used against TH detected preferentially TH1 protein. The two th genes, probably originated as a result of genome duplication, thus show complementary expression, although th1 is predominant in the brain and th2 in the periphery. th2 may be a novel essential factor in regulation of catecholamine synthesis in zebrafish.     

Ultrastructural localization of acetylcholinesterase activity in primary cultures of rat substantia nigra

Summary Ultrastructural localization of acetylcholinesterase activity was studied in primary cultures of the substantia nigra microdissected from newborn rat brains. Light microscopic observations were also made on the characteristics of dopamine neurones and acetylcholinesterase containing cells in these cultures. Ultrastructurally acetylcholinesterase activity was localized in the nuclear envelope and rough endoplasmic reticulum of neurones, which had deeply infolded, round or oval nucleus, a prominent Golgi apparatus and varying amounts of rough endoplasmic reticulum. In the neuropil acetylcholinesterase activity was seen within microtubules of neuronal processes and in the rough endoplasmic reticulum of dendrites. The enzyme activity was also demonstrated within the nuclear envelope and rough endoplasmic reticulum of probably capillary endothelial cells. Dopaminergic neurones were identified on the basis of the green catecholamine fluorescence they exhibited. Small dopaminergic neurones could be observed and there was indirect evidence that these cells did not stain for acetylcholinesterase.     

The development of histochemically demonstrable cholinesterases in the rat neostriatum in vivo and in vitro

The development of acetylcholinesterase (AChE) and non-specific cholinesterase (NsChE) activity was studied in the rat neostriatum by the light and electron microscope using three thiocholine methods. The AChE activity was first demonstrable only in the lateral parts of the nucleus, and during the early postnatal development the most intense activity was in the cell bodies, whilst the typical intense staining of the neuropil of adult animals was seen in two-week-old rats. Two types of AChE-containing cells were observed in the neostriatum of rats younger than two weeks and in cultures of newborn rat neostriatal cells. The neuropil of the cultures showed weak activity in the membranes of thin preterminal processes. In the neuropil of old rats, NsChE activity was present in the membranes of nerve cell processes. The capillary endothelial cells of newborn rats contained both AChE and NsChE. During subsequent development, the AChE activity disappeared, whilst for NsChE no change was seen in the distribution of activity seen in newborn or young adult rats less than three months old.     

Histamine-containing peripheral neuronal and endocrine systems

An immunohistochemical method was developed to detect histamine in tissues. The aim of this study was to reveal the cellular stores of histamine in the gastrointestinal tract, pituitary, and adrenal gland. Histamine-containing nerve fibers were found in both rat and guinea pig gut. The origin of at least some of these fibers in the rat ileum was the submucous ganglion cell layer. In the rat stomach, numerous enterochromaffin-like cells exhibited histamine immunofluorescence, and endocrine cells in the ileum and jejunum contained histamine. Only mast cells contained histamine in the neurohypophysis. A large number of process-bearing cells in the guinea pig but not in the rat adrenal medulla contained histamine. The study shows that histamine is present in peripheral nerves and endocrine cells in addition to mast cells, and may function as a neurotransmitter or hormone.     

Notes on the morphological variation of the rotifer species Keratella cochlearis (Gosse) s.l. in one eutrophic pond

Morphological variation of Keratella cochlearis (Gosse) s.l.were monitored during two years in one eutrophic pond in centralFinland. Nine different taxonomical forms were found duringthe observations. Very significant negative correlation wasfound between water temperature and total length of tecta series.Some forms (forms of hispida series and irregularis series)were found only during warm water seasons. The lorica structureof different morphs was also studied by SEM techniques and besidesin the plaque patterns, differences were found among pustulationand pustule structure of different types.     

The development of histochemically demonstrable cholinesterases in the rat neostriatum in vivo and in vitro

Summary The development of acetylcholinesterase (AChE) and non-specific cholinesterase (NsChE) activity was studied in the rat neostriatum by the light and electron microscope using three thiocholine methods. The AChE activity was first demonstrable only in the lateral parts of the nucleus, and during the early postnatal development the most intense activity was in the cell bodies, whilst the typical intense staining of the neuropil of adult animals was seen in two-week-old rats. Two types of AChE-containing cells were observed in the neostriatum of rats younger than two weeks and in cultures of newborn rat neostriatal cells. The neuropil of the cultures showed weak activity in the membranes of thin preterminal processes. In the neuropil of old rats, NsChE activity was present in the membranes of nerve cell processes. The capillary endothelial cells of newborn rats contained both AChE and NsChE. During subsequent development, the AChE activity disappeared, whilst for NsChE no change was seen in the distribution of activity seen in newborn or young adult rats less than three months old.