A4 Levels Research Articles

Tendon excursion and dehiscence during early controlled mobilization after flexor tendon repair in zone II: An x-ray stereophotogrammetric analysis

The effect of different methods on early controlled mobilization of the flexor profundus tendon regarding tendon excursion and dehiscence was examined during treatment of 20 tendons in 18 patients. An application of radiographic stereophotogrammetric analysis on movements of tendon tissue was developed and the tendons studied during the early postoperative period. Considerable differences of tendon excursion were found between the various mobilization methods and were dependent on the level of injury within zone II. The use of a mobilization method that includes a component of controlled active flexion is suggested for injuries at the A3 and A4 levels. This radiographic stereophotogrammetric analysis method developed for tendon excursion and dehiscence is new and provides knowledge that cannot be obtained in any other way.

The role of endogenous gibberellins in the formation of ?-amylase by aleurone layers of germinating barley caryopses

Using sensitive and selective immunological assays we have shown that in germinating caryopses of Hordeum vulgare L. cv. Himalaya, the level of gibberellin A4 (GA4) rises approximately 18-to 20-fold shortly (2-4 h) before α-amylase activity increases. Gibberellin A4 is the predominant immunoreactive gibberelin during these developmental stages and reaches a peak amount of approximately 9 pmol per caryopsis about 48 h after imbibition. Isolated aleurone layers produce GA4 in the presence of an exogenous gibberellin, such as GA1, which is not a biosynthetic precursor for GA4. Experiments with inhibitors of gibberellin biosynthesis indicate that gibberellin synthesis is required in this tissue for the induction of α-amylase. The inductive effect of exogenously applied GA1 is indirect and appears to be mediated by GA4. Embryos form predominantly GA1; however, very little of this material is released by isolated embryos into the incubation medium. The results presented make it unlikely that the role of the embryo in the process of α-amylase induction in aleurone layers is to provide gibberellins or gibberellin precursors.

Low temperature, gibberellin and acid lipase activity in removal of apple seed dormancy

AbstractThe activity of acid lipase and the level of gibberellin A4 (GA4) were determined in apple embryos excised from seeds after different time periods of stratification and subsequently cultured in darkness at 4°C or at 25°C. Enzyme activity and GA4 content were higher at 4°C. Exogenous gibberellin stimulated lipase activity, while AMO‐1618, an inhibitor of gibberellin biosynthesis, inhibited, to the same degree, both the enzyme activity and the GA4 accumulation. The involvement of GA4 and lipolytic enzymes in cold‐mediated removal of embryonal dormancy has been discussed and compared with the role of these two factors in light‐stimulated germination of dormant apple embryos, described earlier (Smoleńska and Lewak 1974).

Contrasting sounds in the upper male voice

Four sounds were contrasted in the upper male voice. The sounds were identified as follows: (1) falsetto; (2) head tone; (3) pharyngeal voice; (4) operatic head voice. All sounds were sung by a tenor on the vowel /a/ at a pitch level of A4, 415 Hz. Spectrographic analyses were performed to determine what physiological relationships might be inferred among the sounds. The length of time the singer was able to sustain each sound was tested in order to gain information concerning the relative air flows. The results show that the pharyngeal voice and operatic voice have much more energy in the high partials and have much lower rate of air flow. This evidence indicates that these two sounds are characterized by much more complete closure of the glottis than is exhibited in the other two sounds. It is concluded that the four sounds are produced by only two different laryngeal adjustments. Acoustical differences accounting for differentiation of sounds produced by the same laryngeal setting are discussed. A recommendation is made concerning the pedagogical use of registers and suggestions are made for further research.

Regional Hospital Staffing

<b>Introduction:</b> A dysregulation between pro-inflammatory and pro-resolution mediators has been proposed as a potential contributor to chronic persistent inflammation in bronchiectasis. <b>Aim:</b> The aim of this study was to characterise lipids in the blood and airways in clinically stable bronchiectasis patients. <b>Methods:</b> 6 healthy volunteers, 10 mild, 15 moderate and 9 with severe bronchiectasis were recruited whilst clinically stable. All participants had blood taken and underwent bronchoscopy [bronchoalveolar lavage (BAL) and brushings obtained]. Lipids were measured by liquid chromatography and mass spectrometry and transcription of lipoxin A4 biosynthetic enzymes [5 Lipoxygenase(LOX), LTA4 hydrolase, 15LOX-A and 15LOX-B] was assessed by qRT-PCR. The AA metabolite lipids assessed were: anti-inflammmatory and pro-resolution Lipoxin A4, and the generally classified pro-inflammatory mediators Prostaglandin (PG)E2, 5 hydroxyeicosatetraenoic acid (5-HETE), 15 hydroxyeicosatetraenoic acid (15-HETE), Leukotriene (LT)B4 and 9-hydroxyoctadecadienoic acid (9-HODE). <b>Results:</b> In serum, there were significantly lower levels of Lipoxin A4 and higher levels of PGE2, 15HETE and LTB4 in moderate/severe disease compared to healthy controls, p=0.04, p=0.03, p=0.03 and p=0.02 respectively. In BAL, significantly higher levels of PGE2, 5-HETE, 15-HETE, 9 HODE and LTB4 in moderate/severe disease compared to healthy donors, p&lt;0.0001, p=0.004, p=0.005, p=0.04 and p&lt;0.0001 respectively. LTA4 hydrolase was the most abundantly expressed RNA in bronchial brushings, and 15LOX-B the least abundant gene. <b>Conclusion:</b> Dysregulation of LXA4 biosynthetic genes shift the balance to a pro-inflammatory mediator profile contributing towards persistent inflammation.