Significance of 'Langer's axillary arch' in axillary dissection

The axillary arch is reported to occur in 7% of the population, but in our experience has only been observed in 0.25%. The anatomical features are described and its importance in axillary dissection is indicated. In addition, its relevance to the prevention of lymphoedema and to the construction of latissimus dorsi flaps is discussed. The axillary arch should be considered in the differential diagnosis of axillary swellings.     

Flow dynamics through spinal needles

We examined the flow pattern produced when liquid dye was actively injected into a fluid medium at various flows through five different commonly used spinal needles. At all flows, the Whitacre-type needles produced a directional stream exiting at an angle from the longitudinal axis. At intermediate rates the stream developed tracks which disappeared at faster rates. The Quincke needle always produced an undeviated stream of dye and did not form tracks at any flow rate. When a perspex plate (representing the spinal cord) was interposed in front of the needle, the dispersion of dye was always unidirectional from the Whitacre needle and bidirectional from the Quincke needle. The dye adhered to the surface of the plate as a concentrated film at slow rates and at faster rates it dispersed turbulently for both types of needle.     

Neuropharmacological characterization of 1-aminocyclopropane-1-carboxylate and 1-aminocyclobutane-1-carboxylate, ligands of the N-methyl-D-aspartate-associated glycine receptor

Following intravenous administration, 1-aminocyclobutane-1-carboxylate (ACBC, 100 mg/kg), a N-methyl-D-aspartate (NMDA)-associated glycine receptor antagonist, was eliminated with a T1/2 of 5 min in mouse brain and 4 min in rat cerebrospinal fluid (CSF). 1-Aminocyclopropane-1-carboxylate (ACC), a NMDA-associated glycine receptor agonist, was found to have a T1/2 of less than 5 min in mouse brain. ACC and ACBC did not alter basal cerebellar cGMP. Glycine and D-serine increased cGMP, and 1-hydroxy-3-aminopyrrolidone-2 (HA-966), a glycine antagonist, reversed the D-serine-induced increases in cGMP. In contrast, ACBC did not reverse the D-serine-induced increases in cGMP. These data suggest that despite their brain bioavailability and marked potency at the glycine receptor in vitro, ACC and ACBC are rapidly inactivated and thus have limited in vivo utility.     

Phylogenetic analysis of rhinovirus isolates collected during successive epidemic seasons

Human rhinoviruses (HRV) have been shown to be the major causative agent for mild respiratory infections, but also associated with more serious diseases, such as acute otitis media and pneumonia in children, and asthma. Despite the economical and medical importance of HRV, little is known about the circulation and genetic diversity of HRV during a given season. The aim of this study was to genetically characterize HRV strains causing acute respiratory infections in a cohort of small children during a 2 years follow-up time. Genetic relationships between 61 HRV field isolates were studied using partial genomic sequencing in the VP4/VP2 region (420 nt) and phylogenetic analysis of these sequences. Sequences from the clinical isolates clustered in the two previously known phylogenetic clades, the designated genetic group 2 (including HRV 14) being more predominant. The maximum genetic variation within group 1 was 32.3% and within group 2 it was 32.7%. Several distinct clusters could be observed, some of which were strictly seasonal, whereas some other variants were detected during several seasons. The results of this study show striking genetic diversity of the HRV strains circulating in a given community during a short time.