Molecular identification of a small supernumerary marker chromosome by in situ hybridization: diagnosis of an isochromosome 18p with probe L1.84

A dysmorphic child was found by cytogenetic analysis to have an extra small marker chromosome. The marker chromosome was shown to possess a chromosome 18 centromere by in situ hybridization, and probably represents an isochromosome 18p. Centromere specific probes should be of value in identifying extra small marker chromosomes, and thereby provide better understanding of the clinical significance of these.     

Intraincisional antibiotic in addition to systemic antibiotic treatment fails to reduce wound infection rates in contaminated abdominal surgery

One hundred ninety patients with peritonitis at the time of abdominal surgery were allocated at random to systemic antibiotic treatment alone or systemic antibiotic treatment combined with topical application of antibiotics in the wound at the time of wound closure. The overall wound infection rate was 17 percent without significant difference between the two treatment groups (P>0.80).     

Computer-assisted three-dimensional reconstruction of the hippocampal region based on serial sections

A large series of rabbit hippocampal Neo-Timm stained sections were manually aligned, digitized, and by a modified median filtration noise reduced and reconstructed into a three-dimensional object. From the presented simulated grey tone cuts of this object, the reader may assemble a rabbit hippocampal model, that spatially illustrates its anatomy.     

Pinacidil uptake and effects in the isolated rabbit heart

The myocardial accumulation of pinacidil showed one-compartment characteristics with a half-time of 1.11 min., whereas the disposition followed three-compartment kinetics with half-times for the relevant two redistributory and the terminal phases of 0.39, 1.51 and 5.44 min., respectively. At a steady-state drug concentration in the perfusate of 6.12 nmol ml-1, the average concentration of pinacidil in the myocardium was 20.6 nmol g-1. The accumulated amount could predictically be referred with 57% to a central and 31 and 12% to two peripheral (deeper) drug pools. The pharmacodynamic effects of pinacidil in the isolated perfused rabbit heart were studied at stepwise increasing concentrations from 0.15 to 100 microM. Coronary flowrate increased initially up to 24.5% at 1.5 microM pinacidil and then gradually decreased. Amplitude and velocity of contraction were both inhibited in a biphasic way up to 92.7 and 94.1%, respectively. Apparent dynamic steady states developed within 13-15 min. The computer-derived inhibitory Em-values related to the first phase were 49.2 and 52.4% and those related to the second phase were 111.7 and 108.3%, respectively. Heart frequency decreased monophasically and exhibited an inhibitory Em-value of 19.6%. Oxygen consumption decreased at pinacidil concentrations higher than 15 microM and the Em-value was 69.7%. The frequency-corrected QT-interval decreased biphasically and the related inhibitory Em-values were 8.6 and 58.7%. The QRS-interval did not change and the PQ-interval only showed a minor increase at the highest pinacidil concentration. Our findings are compatible with the concept of pinacidil being a potassium channel opener.     

Guidance of dopaminergic neuritic growth by immature astrocytes in organotypic cultures of rat fetal ventral mesencephalon.

Astrocytes, with their many functions in producing and controlling the environment in the brain, are of great interest when it comes to studying regeneration after injury and neurodegenerative diseases such as in grafting in Parkinson's disease. This study was performed to investigate astrocytic guidance of growth derived from dopaminergic neurons using organotypic cultures of rat fetal ventral mesencephalon. Primary cultures were studied at different time points starting from 3 days up to 28 days. Cultures were treated with either interleukin-1 beta (IL-1 beta), which has stimulating effects on astrocytic proliferation, or the astrocytic inhibitor cytosine arabinoside (Ara-C). Tyrosine hydroxylase (TH)-immunohistochemistry was used to visualize dopaminergic neurons, and antibodies against glial fibrillary acidic protein (GFAP) and S100 beta were used to label astrocytes. The results revealed that a robust TH-positive nerve fiber production was seen already at 3 days in vitro. These neurites had disappeared by 5 days. This early nerve fiber outgrowth was not guided by direct interactions with glial cells. Later, at 7 days in vitro, a second wave of TH-positive neuritic outgrowth was clearly observed. GFAP-positive astrocytic processes guided these neurites. TH-positive neurites arborized overlying S100 beta-positive astrocytes in an area distal to the GFAP-positive astrocytic processes. Treatment with IL-1 beta resulted in an increased area of TH-positive nerve fiber network. In cultures treated with Ara-C, neither astrocytes nor outgrowth of dopaminergic neurites were observed. In conclusion, this study shows that astrocytes play a major role in long-term dopaminergic outgrowth, both in axonal elongation and branching of neurites. The long-term nerve fiber growth is preceded by an early transient outgrowth of dopamine neurites.     

Hypoplasia of the Posterior Leaflet as a Rare Cause of Congenital Mitral Insufficiency

A bstract A rare case of congenital mitral insufficiency characterized by the hypoplasia of the posterior leaflet is reported. At operation, the mitral valve was successfully repaired by a ring annuloplasty, which created a satisfactory surface of coaptation between the anterior leaflet and the bulky posterior muscular structure. The presence of this posterior muscular structure represents a developmental arrest at the stage of conversion from muscular chordae and leaflets to thin connective structures.     

Tropical pyomyositis in a temperate climate in an immunocompetent adult.

Tropical pyomyositis, though common in Africa, South America, and the South Pacific, is relatively rare in North America. Reported is the case of a patient who developed chest wall muscle abscesses after sustaining minor chest wall muscle trauma and presented to the emergency department appearing acutely ill. He was treated surgically with irrigation and debridement of the abscesses as well as with antibiotics and recovered fully over a seven-month course. This case illustrates important aspects of tropical pyomyositis with a discussion of the natural history of this disease as well as diagnostic modalities and treatment options for this virulent infectious process that is usually caused by penicillin-resistant Staphylococcus aureus.