Diagnosis of Metastatic Pleomorphic Giant Cell Carcinoma of the Pancreas Using Fine Catheter Aspiration Cytology

The value of fine catheter aspiration cytology in the diagnosis of metastatic tumours is illustrated by a case of pleomorphic giant cell carcinoma of the pancreas which had metastasized to the peritoneal cavity. The finding of unequivocal malignant cells obviated the need for further diagnostic procedures. Electron microscopy and immunostaining further substantiated the light microscopic cytodiagnosis and identified the tumour type and source of the primary tumour. Furthermore, subsequent cell block preparation from the aspirated material demonstrated the histological features of this tumour.     

Growth and yield of maize at different altitudes in Rhodesia

A late (SR 52) and an early (N × K) variety were grown, with irrigation, on well fertilized soil at three sites, Chiredzi (altitude 420 m), Henderson (1260 m) and Grasslands (1620 m). Mean incoming radiation was similar at all sites, while mean temperature decreased as altitude increased. Final total and grain dry weights were greatest at Henderson, and those of SR 52 exceeded those of N × K, although not greatly at Chiredzi. Initially, leaf area index (L) decreased with increase in altitude, but plants flowered later as altitude increased, and L at the time of flowering was greatest at Henderson. L at flowering was greater in SR 52 than in N × K, though only slightly so at Chiredzi. Leaves withered sooner after flowering at Chiredzi and Grasslands than at Henderson, but leaves of the two varieties withered at about the same time after flowering at each site. During most of the vegetative phase the efficiency of the leaves and crop growth rate (C) increased with decrease in altitude, and were greater in N × K than in SR 52. More dry matter was accumulated after flowering at Henderson than at the other sites, and more by SR 52 than by N × K at Henderson and Grasslands, but not at Chiredzi. Leaf area duration (D) after flowering was greater at Henderson than elsewhere, and greater in SR 52 than in N × K, except at Chiredzi. After flowering leaf efficiency (dry weight increase ÷D) was least at Henderson and greatest at Grasslands, but differed little between varieties at each site. The fraction in the grain of the dry matter accumulated after flowering decreased with increase in altitude and was greater in SR 52 than in N × K.     

Polyphosphate-dependent enzymes in some coryneform bacteria isolated from sewage sludge

Abstract Eleven isolates obtained from a laboratory sewage treatment plant, most of them presumptively assigned to the coryneform genera Curtobacterium and Aureobacterium were studied for the presence of intracellular polyphosphates and polyphosphate dependent enzymes. All isolates stored polyphosphates and showed adenylate kinase activities ranging from 64 to 815 mU mg⁻¹. Polyphosphate:AMP phosphotransferase could only be detected in one isolate. Three isolates showed a polyphosphate kinase activity also in minor amounts from 15 to 17 mU mg⁻¹. A polyphosphate dependent NAD or 3-phosphoglycerate kinase could not be detected. Polyphosphate glucokinase activity was measured in cell-free extracts of nine isolates ranging from 2 to 376 mU mg⁻¹. Three isolates showed in addition to the polyphosphate glucokinase, a glucose-6-phosphate-dependent NAD kinase. For the regeneration of NADP from NAD and polyphosphate, this enzyme system may give the isolates a distinct competitive advantage, especially for anabolic processes. The polyphosphate-dependent enzymes reported here may play an additional role in the complex process of 'biological' phosphate removal from wastewater.     

Effect of soil temperature on sorghum emergence

Soil temperature strongly influences both percentage germination and time of emergence of sorghum. Ten hybrids were hand planted in the field. Soil surface was irrigated frequently and emerging plants were counted daily. On three treatments, soil temperature was monitored every hour at five depths. Treatments were designed to achieve a range in surface soil temperature. Results of the study indicated an optimum germination temperature of about 23°C and a heat requirement of 67 degree days. The maturity classifications of the hybrids did not show a consistent trend in their heat requirement for emergence.     

Genes and pseudogenes for human U2 RNA: Implications for the mechanism of pseudogene formation

Three loci, designated U2/4, U2/6 and U2/7, which contain sequences related to human U2 RNA, have been studied. The U2/6 locus contains a tandem array of bona fide U2 genes. U2/4 and U2/7, in contrast, contain pseudogenes whose sequences deviate significantly from that of mammalian U2 RNA. The two pseudogenes appear to have been created by different mechanisms. The sequences that flank the pseudogene in the U2/4 locus lack homology to the corresponding sequences in functional human U2 genes, except for 10 base-pairs immediately following the 3′ end. The conserved 3′-flanking segment is homologous to those nucleotides that are present in a U2 RNA precursor. No direct repeats flank the pseudogene in the U2/4 locus. The observations thus suggest that a complementary DNA copy of the U2 RNA precursor was inserted into a blunt-ended chromosomal break to generate the U2/4 locus.The U2/7 locus, in contrast, revealed flanking sequence homology when compared to functional U2 genes, both on the 5′ and 3′ sides of the pseudogene. The homology was interrupted on both sides by repetitive sequences belonging to the Alu family. On the 5′ side the homology continues beyond the Alu repeats whereas on the 3′ side it ends precisely at the Alu repeat. This Alu repeat is inserted in a region where a homocopolymeric region of alternating C and T residues is located in functional U2 loci. The observed organization of the U2/7 locus suggests that a previously functional U2 locus was invaded by Alu repeats and subsequently accumulated base substitutions to become a pseudogene.     

Genetic Association between H-2 Gene and Testosterone Metabolism in Mice

SEVERAL characters involved in sexual dimorphism or male reproductive performance are influenced by genetic factors that are linked with the histocompatibility-2 (H-2) system of the mouse. These factors influence sperm cell production and function^1–4 interstrain differences in relative weights of vesicular gland and testis^4,5, immune response to the male-specific histocompatibility antigen^6,7 and an androgen-dependent allotypic serum protein designated Slp⁸. Our finding of an H-2 linked gene influencing the size of such male hormone-dependent organs, as is the vesicular gland and testis, suggested that the amount of testosterone in plasma may be influenced by an H-2 linked gene. Whereas the genetic control of some hormonally determined traits is considered to be polygenic^9,10, other data indicate some endocrine variation is due to allelic substitution at a single locus or very few loci^11–14. These genes in the mouse genome have not yet been located.     

The visual cortex alpha-scanning: EEG and magnetic resonance tomography data

Exact localization of equivalent current dipoles (ECD) was obtained by combining the EEG and the MRI mapping allowing to trace the ECG displacement over the cortex. The data obtained corroborate localization of the alpha-rhythm ECD in the Gyrus Calcarina: the human primary visual cortex. Successive shifts of the ECD over this area during generation of each alpha-wave, were revealed. The data are discussed in the light of the "scanning hypothesis" that predicted a certain functional meaning of the alpha-wave spreading for cortical processing of sensory information.     

Isolation of a rhabdovirus during outbreaks of disease in cyprinid fish species at fishery sites in England

A virus was isolated during disease outbreaks in bream Abramis brama, tench Tinca tinca, roach Rutilis rutilis and crucian carp Carassius carassius populations at 6 fishery sites in England in 1999. Mortalities at the sites were primarily among recently introduced fish and the predominant fish species affected was bream. The bream stocked at 5 of the 6 English fishery sites were found to have originated from the River Bann, Northern Ireland. Most fish presented few consistent external signs of disease but some exhibited clinical signs similar to those of spring viraemia of carp (SVC), with extensive skin haemorrhages, ulceration on the flanks and internal signs including ascites and petechial haemorrhages. The most prominent histopathological changes were hepatocellular necrosis, interstitial nephritis and splenitis. The virus induced a cytopathic effect in tissue cultures (Epithelioma papulosum cyprini [EPC] cells) at 20 degrees C and produced moderate signals in an enzyme immunoassay (EIA) for the detection of SVC virus. The virus showed a close serological relationship to pike fry rhabdovirus in both EIA and serum neutralisation assays and to a rhabdovirus isolated during a disease outbreak in a bream population in the River Bann in 1998. A high degree of sequence similarity (> or = 99.5% nucleotide identity) was observed between the English isolates and those from the River Bann. Experimental infection of juvenile bream, tench and carp with EPC cell-grown rhabdovirus by bath and intraperitoneal injection resulted in a 40% mortality of bream in the injection group only. The virus was re-isolated from pooled kidney, liver and spleen tissue samples from moribund bream. The field observations together with the experimental results indicate that this rhabdovirus is of low virulence but may have the potential to cause significant mortality in fishes under stress.     

Genetic signature of the colonisation dynamics along a coastal expansion front in the damselfly Coenagrion scitulum

1. Many insects are expanding their distribution range polewards as a result of climate change, which has been shown to be associated with founder effects leading to a reduction in genetic diversity and an increase in genetic differentiation. These spatial genetic patterns may arise from colonisation from a broad expansion front or a limited neighbourhood after a stepping stone model of dispersal. The temporal persistence of such founder effects are poorly understood, mainly because studies looking at the fine‐scale initial temporal dynamics of the genetic signature of a range expansion are rare. 2. Using microsatellite markers, we performed a detailed spatiotemporal genetic analysis of the range expanding damselfly Coenagrion scitulum (Rambur) along a coastal axis during the first years after colonisation. 3. A decrease was in (private) allelic richness when going northwards along the coastline, which is consistent with a scenario of cumulative founder events. In spite of the spatiotemporal dynamics in the observation records of the species along the coastline, the spatial genetic data indicated a major contribution from the broad expansion front during the colonisation of the coastline rather than a stepping‐stone colonisation process. 4. The fine‐scale temporal dynamics of the range expansion indicated the absence of persistent founder effects and instead showed considerable temporal instability in genetic indices at the more northern edge populations. This may be explained by genetic immigration and admixture from the broad expansion front in this active disperser.