[Diagnostic mode and tumor staging of breast cancers in the setting of opportunistic screenings]. / Diagnoseform und Tumorstadien von Mammakarzinomen unter Bedingungen des opportunistischen Screenings.

PURPOSE: To analyze data at the time of diagnosis of breast cancer in three radiology practices in Austria in the setting of opportunistic screening. MATERIALS AND METHODS: In 529 women (ages 31 - 89, mean age 61.1) with breast cancer, the mode of diagnosis (detected clinically or by opportunistic screening), the local tumor stages, and intervals between screening examinations were assessed. RESULTS: In 33.6 % (178 of 529) of the cases, the breast cancer was detected clinically, and in 66.4 % (351 of 529) of the cases, the cancer was detected by opportunistic screening. Cancers in prognostically favorable stages (in situ carcinomas, pT1 a, pT1 b, pT1c) were detected by opportunistic screening in 79.9 % of the cases. The clinically detected cancers were in locally advanced stages (pT2, pT3) in 58.4 % of the cases. In the majority of clinically detected cases (75 %), the women had never had a mammogram before or had not had a recent one. In 13 % of the cases detected by opportunistic screening, diagnosis was made during the first exam, in 40 % of the cases, the period since the last mammogram was less than 24 months, and in 47 % of the cases, this period was greater than 24 months. CONCLUSION: In our patients the majority of breast cancers were detected in early stages by opportunistic screening. The use of an organized system with exams at regular intervals may further reduce the number of advanced cancers.

A macroglomerulus in the antennal lobe of leaf-cutting ant workers and its possible functional significance.

Ants have a well-developed olfactory system, and pheromone communication is essential for regulating social life within their colonies. We compared the organization of primary olfactory centers (antennal lobes, ALs) in the brain of two closely related species of leaf-cutting ants (Atta vollenweideri, Atta sexdens). Both species express a striking size polymorphism associated with polyethism. We discovered that the ALs of large workers contain a substantially enlarged glomerulus (macroglomerulus, MG) at the entrance of the antennal nerve. This is the first description of an MG in non-sexual individuals of an insect. The location of the MG is laterally reversed in the two species, and workers of different size express a disproportional allometry of glomerular volumes. While ALs of large workers contain an MG, glomeruli in small workers are all similar in size. We further compared electroantennogram (EAG) responses to two common trail pheromone components of leaf-cutting ants: 4-methylpyrrol-2-carboxylate and 2-ethyl-3,6-dimethylpyrazine. At high concentrations the ratio of the EAG signals to 2-ethyl-3,6-dimethylpyrazine versus 4-methylpyrrol-2-carboxylate was significantly smaller in A. vollenweideri compared with the ratio of EAG signals to the same two components in A. sexdens. The differences in EAG signals and the species specific MG location in large workers provide correlative evidence that the MG may be involved in the detection of the trail pheromone.

Intracellular endosymbiotic bacteria of Camponotus species (carpenter ants): systematics, evolution and ultrastructural characterization.

Intracellular endosymbiotic bacteria inherent to ants of the genus Camponotus were characterized. The bacteria were localized in bacteriocytes, which are specialized cells of both workers and queen ants; these cells are intercalated between epithelial cells of the midgut. The bacteriocytes show a different morphology from the normal epithelial cells and carry a large number of the rod-shaped Gram-negative bacteria free in the cytoplasm. The bacteria were never observed in the neighbouring epithelial cells, but they were found intracellularly in oocytes, strongly indicating a maternal transmission of the bacteria. The 16S DNA encoding rrs loci of the endosymbionts of four species of the genus Camponotus derived either from Germany (C. herculeanus and C. ligniperdus), North America (C. floridanus) or South America (C. rufipes) were cloned after polymerase chain reaction (PCR) amplification using oligonucleotides complementary to all so far known eubacterial rrs sequences. The DNA sequences of the rrs loci of the four endosymbionts were determined, and, using various genus- and species-specific oligonucleotides derived from variable regions in the rrs sequences, the identity of the bacteria present in the bacteriocytes and the ovarian cells was confirmed by PCR and in situ hybridization techniques. Comparison of the 16S DNA sequences with the available database showed the endosymbiotic bacteria to be members of the gamma-subclass of Proteobacteria. They formed a distinct taxonomic group, a sister taxon of the taxons defined by the tsetse fly and aphid endosymbionts. Within the gamma-subclass, the cluster of the ant, tsetse fly and aphid endosymbionts are placed adjacent to the family of Enterobacteriaceae. The evolutionary tree of the ant endosymbionts reflects the systematic classification and geographical distribution of their host insects, indicating an early co-evolution of the symbiotic partners and a vertical transmission of the bacteria.

Membrane differentiation in rat dorsal root ganglia and possible consequences for back pain.

The ferric ion-ferrocyanide staining procedure (Quick and Waxman, J. Neurol. Sci., 31 (1977) 1-11), believed to label selectively membrane regions with high sodium-channel content and hence elevated electrical excitability, was used to stain lower lumbar dorsal root ganglion (DRG) neurons in adult rats. In many such cells, including both large type A neurons and small type B neurons, the initial segment of the stem axon and a variable portion of the adjacent soma surface stained heavily. It is suggested that this membrane specialization represents a zone of elevated excitability which may contribute to ectopic impulse generation in DRGs.