Family studies of hereditary hemochromatosis in Denmark and the Faroe Islands

Summary Pedigree studies were performed based on one Faroese and four Danish probands with overt idiopathic hemochromatosis (IH). The study consisted of HLA typing and determination of biochemical iron status indicators (serum transferrin saturation, serum ferritin). In total, 130 persons were evaluated. The screening identified 6 homozygous (h/h) subjects with preclinical IH, 46 heterozygous (h/n), and 8 normal (n/n) subjects, while 39 subjects were classified as normal or heterozygous (n/h?). One family demonstrated both a homozygous x heterozygous as well as a heterozygous x heterozygous mating. Recombination between the HLA region and IH locus occurred possibly in three subjects in three different families. The significance of detailed screening in families with probands with IH is discussed.     

Molecular phylogeny and host-plant use (Lamiaceae) of the Thymogethes pollen beetles (Coleoptera)

The 24 members of the Euro-Asiatic genus Thymogethes are highly specialized pollen beetles associated as larvae with flowers of Lamiaceae Nepetoideae. All members of the genus were analysed in within the framework of an integrative taxonomy approach, which was aimed to reconstruct the phylogenetic relationships, as well as the possible pattern of evolution of their larval-host-plant association. Evidence from multiple molecular markers [COI; 16S; H3], combined with an estimation of divergence times using an average rate of 0.0177 substitutions/site/My among branches, placed the origin of the genus at a minimum of 9–10 Mya. This date of origin approximates the known evolution of the host plants in Euro-Mediterranean areas. Evidence from combined molecular and cladistic morphological analyses resulted in suitable agreement with the previously established morphology-based systematics of the genus, although members of the exilis species-group were split into three clades. The only disagreement between results of this new combined phylogeny and previous classification is in the exclusion of “Thymogethes” grenieri. This species is herein positioned outside the genus, based on molecular evidence. Our analysis depicts several Thymogethes species differentiating in the last few Mys, specifically those included in the T. lugubris species-group. Combined evidence from DNA, morphology and ancestral state parsimony reconstruction of larval-host-plant associations suggests that subtribe Menthinae likely represents the ancestral host plants, with a series of independent host shifts during the radiation of the clade, in association first with Menthinae and subsequently with Lavandulinae and Nepetinae. Steno-oligophagy is the most frequent (86%) condition, while strictly monophagous species are less numerous (14%).     

Methods and Errors in Measurements of Synovial Fluid Volume in Stifles with Low Volume and High Viscosity Synovial Fluid. An Experimental Study in Goats

Synovial fluid (SF) volume was calculated using various methods in the stifles of goats, in which the cranial cruciate ligament had been transected on one side. Measurements were performed prior to surgery and again 4,8, and 18 weeks following surgery, by measuring the dilution of an injected radioactive tracer diluted by the SF. Later, 7 months following surgery, SF volume measurements using simple arthrocentesis were performed on stifles in 9 of the goats, and the SF that could not be aspirated, was calculated using 2 indirect methods simultaneously on identical fluids in 3 of these goats. SF was also collected directly during staged arthrotomy of the stifles in 4 goats. There were conflicting results between methods, but the resulting calculated SF volumes seemed to be larger in the operated stifles compared to the controls for all the methods at about the same degree. The 2 indirect methods used to calculate the fluid remaining in the joints following arthrocentesis gave disparate volume calculations. The experiments revealed sources of error in all methods. Direct methods failed to acquire the total fluid volume, and indirect methods were subject to improper mixing and escape of the injected fluid or synovial fluid or both. It was concluded that none of the methods could be used to measure the “true” volume of SF, if such a concept exists and can be defined. None of the methods were considered reliable to compare volumes in different type of joints containing this type of fluid. It was, however, concluded that all the methods gave indication of increased SF volume present on a relative basis when paired joints were compared.     

On-line determination of pigment composition and biomass in cultures of microalgae

Summary Rhodomonas sp. was grown in a photo-bioreactor equipped with a measuring cell in a spectrophotometer as part of an external flow loop. The apparent absorbance from 400 to 800 nm of the cell suspension was recorded at predetermined intervals and stored in a computer. From the spectra, the biomass and the concentrations of the two pigments chlorophyll a and phycoerythrin were determined in nitrogen-limited batch cultures.     

Aminergic neuron systems of lobsters: morphology and electrophysiology of octopamine-containing neurosecretory cells

In the American lobster (Homarus americanus) the biogenic amines serotonin and octopamine appear to play important and opposite roles in the regulation of aggressive behavior, in the establishment and/or maintenance of dominant and subordinate behavioral states and in the modulation of the associated postural stances and escape responses. The octopamine-containing neurosecretory neurons in the thoracic regions of the lobster ventral nerve cord fall into two morphological subgroups, the root octopamine cells, a classical neurohemal group with release regions along second thoracic roots, and the claw octopamine cells, a group that selectively innervates the claws. Cells of both subgroups have additional sets of endings within neuropil regions of ganglia of the ventral nerve cord. Octopamine neurosecretory neurons generally are silent, but when spontaneously active or when activated, they show large overshooting action potentials with prominent after-hyperpolarizations. Autoinhibition after high-frequency firing, which is also seen in other crustacean neurosecretory cells, is readily apparent in these cells. The cells show no spontaneous synaptic activity, but appear to be excited by a unitary source. Stimulation of lateral or medial giant axons, which excite serotonergic cells yielded no response in octopaminergic neurosecretory cells and no evidence for direct interactions between pairs of octopamine neurons, or between the octopaminergic and the serotonergic sets of neurosecretory neurons was found.