Principles for reconstruction of traumatic ear defects

Summary Traumatic defects of the auricle are quite common. The eventual success of the repair is considerably influenced by the initial treatment. The different parts of the auricle require different approaches. This paper presents our methods for repairing damage to the cartilaginous frame using autologous ear cartilage grafts, and local flaps from the mastoid region to cover soft tissue defects.     

Complete sequence of the RNA genome of human rhinovirus 16, a clinically useful common cold virus belonging to the ICAM-1 receptor group

We report here the complete nucleotide sequence and predicted polyprotein sequence of HeLa cell-adapted human rhinovirus 16 (HRV16). This virus is more suitable than human rhinovirus 14 (HRV14) for clinical studies, and its growth and physical properties are favorable for biochemical and crystallographic analysis. The complete message-sense RNA genome of HRV16 is composed of 7124 bases, not including the poly(A) tail. An open reading frame, extending from base 626 to 7084 predicts a polyprotein containing 2152 amino acid residues. Comparison with other rhinovirus sequences shows HRV16 is much more representative of human rhinoviruses than HRV14. No apparent relationship was found between receptor group and amino acid sequence in VP1, the capsid protein bearing the binding site for the intercullular adhesion molecule-1 (ICAM-1) in both HRV14 and HRV16.Genbank accession number: L24917.     

A quantitative analysis of the distribution of Purkinje cell axonal collaterals in different zones of the cat's cerebellum: an intracellular HRP study

Summary Purkinje cells in zones a and b of the vermis and zone c in the intermediate cortex of the anterior lobe were intracellularly injected with horseradish peroxidase and the distribution patterns of the varicosities present on their axonal collaterals were quantified and compared at the light microscopic level. The data derived from this study reveal that each individual axonal arbor had a unique pattern of distribution. However, certain principles of distribution could be applied to the collaterals regardless of the cortical location of the parent cell, including the following: 1) the total number of varicosities derived from the axonal collaterals of individual Purkinje cells is relatively uniform; 2) the collateral plexi have a greater extent in the sagittal plane as compared to the transverse plane; 3) the majority of varicosities remain within 200–300 m of the parent cell in both the sagittal and transverse planes; 4) there is a heterogenous distribution of varicosities within the area traversed by the axonal branches; and 5) the majority of varicosities are located within the Purkinje cell layer. Although there were similarities in the pattern of distribution for collaterals, there were also variations which distinguished the plexi in the three zones. The collaterals of zone a cells tended to be the most confined in both the sagittal and transverse planes. In contrast, several cells in zone b and c had branches that extended for relatively long distances in the sagittal plane. In zone b the collaterals have an asymmetric distribution around the cell of origin in the transverse plane. In zones a and c there is a tendency for a more symmetric pattern of distribution in this plane. The similarities in the number and laminar distribution of varicosities, as well as the predominantly sagittal orientation of the collaterals in all zones of the cerebellar cortex suggest that the collaterals subserve a common function throughout the cerebellar cortex. However, variations indicate that there may be subtle differences in the way recurrent collaterals process information in the cerebellar cortex that may be related to the functional heterogeneity or the location of the targets of the collaterals in the three zones analyzed.     

GABA and its neural regulation in rat brown adipose tissue

Summary By using a radioreceptor assay GABA was detectable in rat interscapular brown adipose tissue (IBAT), the levels being 1% those of CNS and 10-fold those of peripheral plasma. Injection of the glutamic acid decarboxylase (GAD) inhibitor 3-mercaptopropionic acid lowered IBAT GABA levels by about half while injection of the GABA transaminase inhibitor -acetylenic GABA increased them by 230%. Rats kept at 4C for 14 days exhibited IBAT GABA levels that were about half those found at 22C. Accumulation of IBAT GABA after -acetylenic GABA increased by 2-fold in cold-exposed rats. Sympathetic denervation of IBAT prevented the effect of the cold environment on GABA content and impaired that on GABA accumulation. GAD activity was detectable in IBAT homogenates and isolated brown adipocytes. Exposure of rats to cold increased V_max of GAD without modifying its Km, regardless of intactness of innervation. In binding studies with³H-GABA as a ligand, two types of sites were uncovered of K_D=14 and 146 nM, respectively. In the presence of 2.5 mM Ca²⁺ bicuculline and baclofen were 57 and 46% as effective as GABA to displace³H-GABA from IBAT binding sites. The results indicate existence, possible synthesis and type A and B receptors of GABA in rat IBAT.     

Radioallergosorbent test (RAST) for specific IgE antibody to lidocaine,procaine and methylparaben

Although anaphylactoid reactions to local anesthetics are well known, a radioallergosorbent test (RAST) to detect specific drug reagin (IgE) anti-body has not been developed. We established RAST for local anesthetics by using carboxylic acid derivatives of lidocaine, procaine and methylparaben. Serum samples were taken from 100 volunteers who were regarded to be nonallergic to the drugs used. Negative RAST values obtained from these volunteers were 1653 ± 254(SD) cpm (lidocaine), 2750 ± 264cpm (procaine), and 2805 ± 336cpm (methyl paraben).(Kokubu M, Oda K, Shinya N: Radioallergosorbent test (RAST) for specific IgE antibody to lidocaine, procaine and methylparaben. J Anesth 3: 74–79, 1989)     

Effect of local blood circulation and absolute torque on muscle endurance at two different knee-joint angles in humans

The effects of the local blood circulation and absolute torque on muscle endurance at different knee-joint angles were determined. The rate of muscle deoxygenation (using near-infrared spectroscopy), and the rate of muscle fatigue (using the slope of integrated electromyography, iEMG) were evaluated concurrently. Nine healthy subjects performed submaximal (50% maximal voluntary contraction, MVC) static knee extension at 50° (extended position, EXT) and 90° (flexed position, FLEX) joint angles until the target torque could no longer be maintained: that time was measured as the endurance time. They exercised with the circulation occluded (OCCL), and without (FREE) to study the possible effects of the local circulation. Although MVC torque was independent of joint angle [mean (SD) FLEX 250.6 (51.7) N·m and EXT 246.5 (46.6) N·m], significantly shorter (P<0.01) endurance time in FLEX [FREE 71.1 (10) s and OCCL 63.1 (8.8) s] than at EXT [FREE 115.3 (30) s and OCCL 106.7 (29.1) s] were obtained in both circulatory conditions. The iEMG-time slope was significantly greater in FLEX at the proximal and distal portion (P<0.05) in both circulatory conditions. Muscle deoxygenation rate in OCCL was significantly greater (P<0.05) at FLEX [20.8 (8.0)%] than EXT [10.9 (4.0)%]. The results would suggest that different knee-joint angle affects muscle endurance even if the local circulation is controlled. Circulatory disturbance would further reduce muscle endurance in EXT, but not in FLEX. Because of the greater muscle internal force in FLEX, local blood flow might be already limited even with a free circulation. The greater muscle deoxygenation and muscle fatigability would be related to the shorter muscle endurance in FLEX. Electronic Publication     

Local thermal sensation and finger vasoconstriction in the locally heated hand

Summary The effects of local heating on finger blood flow (BF) and local thermal sensation (Sens _w ) were studied. Finger BFs in both hands were measured simultaneously; one hand was immersed in water the temperature (T _w ) of which was raised from 35° C to 43°C by steps of 2° C every 10 min, while the other hand was kept atT _w 35°C. FingerBF in the locally heated hand decreased atT _w 37 to 41°C, while fingerBF in the control hand did not alter. Sens_w, in the heated hand showed a dynamic response, initially increasing concomitantly with an increase inT _w , then gradually returning and adapting to a new level of Sens_w. The dynamic response of Sens_w, was not perceived during mental calculation even whenT _w was raised to 40°C, and the reduction in finger blood flow was not observed. These results suggest that finger vasoconstriction caused by local heating closely relates to the dynamic response characteristic of local thermal sensation atT _w above core temperature, and that the perception of local thermal sensation in the central nervous system is involved in the mechanism of this vasoconstrictor response.     

Viral titers in nasal lining fluid compared to viral titers in nasal washes during experimental rhinovirus infection

BACKGROUND: The concentration of rhinovirus in nasal wash specimens from infected volunteers peaks at 48-72 h after inoculation. The volume of expelled nasal fluid peaks at the same time, raising the question of whether the viral concentration in nasal wash reflects viral replication in nasal cells or merely the production of an increased volume of nasal fluid during a cold. OBJECTIVES: To determine the amount of rhinovirus in nasal lining fluid during colds before the nasal fluid has been diluted in a nasal wash. STUDY DESIGN: Rhinovirus titers were determined in nasal wash specimens collected daily for five days from 14 subjects with type16 rhinovirus infection. The urea concentration in nasal lining fluid equals that in blood. By determining the urea concentration in a nasal wash and comparing it to the urea concentration in blood from the same subject, it was possible to determine the amount of dilution of the nasal lining fluid. The dilution factor (reciprocal of the dilution) was then used to calculate the viral concentration in undiluted nasal lining fluid. RESULTS: The dilution factor in 70 nasal washes varied from 5 to 64. The viral GMTs (+S.E.) in nasal washes were 1.79 (+0.3) TCID(50)/ml at 24 h, 3.11 (+0.15) at 48 h, and 2.61 (+0.3) at 72 h. The viral GMTs in nasal lining fluid, based on urea adjusted values, paralleled those in nasal washes but were approximately one log higher. Virus concentrations returned to near baseline values by day 5. CONCLUSIONS: The temporal pattern of rhinovirus shedding observed in nasal wash specimens, with a peak in virus concentration at 48-72 h after infection, is a true indication of virus production in nasal cells and not an artifact of the increased amount of nasal fluid produced during the early phase of a cold.