Site-directed mutagenesis of platelet glycoprotein Ib alpha demonstrating residues involved in the sulfation of tyrosines 276, 278, and 279

The interaction between platelet glycoprotein (GP) Ib alpha and von Willebrand factor (VWF) is essential for initiation of hemostasis. The sulfation of the 3 tyrosine residues 276, 278, and 279 in GPIb alpha is an important posttranslational modification that seems to promote the interaction with VWF. The environment where sulfation of tyrosines occurs has been proposed to contain highly acidic residues. This investigation has examined the highly acidic region from Asp249 to Asp287 in the mature GPIb alpha protein. Changes to most of the carboxylic acids in this region resulted in decreased reactivity to VWF. Only 3 mutants (Glu270Gln, Asp283Asn, Asp283Asn/Glu285Gln/Asp287Asn) resulted in the abolition of sulfation. Two novel mutations were also created. First, a deletion of the 7 amino acids from Tyr276 to Glu282 led to a loss of sulfation and totally abolished VWF binding in the presence of botrocetin. This confirms that it is these 3 tyrosines that undergo sulfation and that this region is crucial for botrocetin-mediated VWF binding. The second mutation involves changing the lysine residues at 253, 258, and 262 to alanine. This also led to distinct changes in VWF binding and abolition of sulfation.     

13C NMR studies of acetate metabolism during sporulation of Saccharomyces cerevisiae.

The sporulation of Saccharomyces cerevisiae in the presence of [2-13C]acetate was studied by 13C NMR spectroscopy. The fate of 13C label was analyzed in vivo and in cell extracts. During the first 4 hr of sporulation the major metabolite produced from [2-13C]acetate utilization was glutamate. From the labeling pattern observed it is concluded that both the tricarboxylic acid cycle and the glyoxylate cycle are operating. After about 4 hr trehalose is made. Comparison of the doublet/singlet ratios for C-1,1(1) and C-6,6(1) of trehalose shows a steady drop in the ratio of C-1, C-2-coupled species over trehalose labeled only at C-1 in the C-1, 2 segment of the molecule. The negative correlation of this ratio with that for the C-5, 6 segment indicates a cycling of glucose through the hexose monophosphate shunt. Subsequently fatty acid biosynthesis commences. Large amounts of saturated fatty acid were made. There were conspicuous differences observed in the metabolism of [2-13C]acetate between sporulating and vegetatively growing cells.     

Head and neck fascia and compartments: No space for spaces

An accurate understanding of the arrangement of cervical fascia and its associated compartments is essential for differential diagnosis, predicting the spread of disease, and surgical management. The purpose of this detailed review is to summarize the anatomic, clinical, and radiological literature to determine what is known about the arrangement of cervical fascia and to highlight controversies and consensus. The current terminology used to describe cervical fascia and compartments is replete with confusing synonyms and inconsistencies, creating important interdisciplinary differences in understanding. The term “spaces” is inappropriate. A modified nomenclature underpinned by evidence‐based anatomic and radiologic findings is proposed. This should not only enhance our understanding of cervical anatomy but also facilitate clearer interdisciplinary communication. © 2014 Wiley Periodicals, Inc. Head Neck 36: 1058–1068, 2014     

Antimicrobial Activities of Skincare Preparations from Plant Extracts

In this study, Tithonia diversifolia Helms. (A Gray), Aloe secundiflora (Miller) and Azadirachta indica (A. Juss) plant extracts were used to make herbal soaps while Thevetia peruviana (Schum) seed oil was used to make a herbal lotion for skincare. The soaps were tested for the growth inhibition of Escherichia coli, and Candida albicans. The lotion was evaluated against Staphylococcus aureus and E.coli. Although Tithonia diversifolia soap exhibited the highest inhibitory effect on the test bacterial strains, it had the least inhibition against C. albicans. Results from this study indicated that the ‘Tithonia diversifolia’ soap would have superior skin protection against the tested bacteria but would offer the least skin protection against C. albicans. The herbal lotion inhibited S. aureus and E. coli in a concentration dependent manner, however, the inhibitory effect was more pronounced on S. aureus.     

Polyarthritis, rash and lymphadenopathy: Case reports of two patients with angioimmunoblastic lymphadenopathy presenting to a rheumatology clinic

Two patients presented with a symmetrical inflammatory polyarthropathy. Both patients fulfilled the diagnostic criteria for angioimmunoblastic lymphadenopathy. We present the two case histories and review the current literature. Although an uncommon disease, the diagnosis of angioimmunoblastic lymphadenopathy should be considered in a patient presenting with polyarthritis and skin rash.     

The effect of an electronic control device on muscle injury as determined by creatine kinase enzyme

The medical literature on the effect of electronic control devices (ECD) on muscle injury is sparse. In this paper, we examine pooled data from five human studies that used creatine kinase (CK) as a marker for muscle injury. CK was measured in five separate studies involving four TASER ECDs with different exposure durations and number of circuits or contact points. Device type, exposure duration, number of circuits or contact points, and CK values at baseline and 24 h after exposure were pooled from these previous studies. Data were analyzed to determine the correlation of CK to duration of exposure, number of contact points, and distance between the probes. The pooled results contained 163 subjects. Seven were withdrawn due to incomplete data, leaving 156 subjects for analysis (median age 36, range 19–67, 93.6% male). 121 (77.6%) subjects had 2 contacts points, 10 (6.4%) had 3 contact points, 18 (11.5%) had 4 contact points, and 7 (4.5%) had 6 contact points. 81 (51.9%) subjects had a 5-s exposure, 64 (41.0%) a 10-s exposure, and, 11 (7.1%) a 30-s exposure. Median baseline CK (145 U/l, IQR 104–217, range 12–1956) did not differ between groups (P = 0.213 for number of contact points, 0.124 for duration). For the number of contacts, the median change in CK for 2 points of contact was 32 (IQR −1 to 1513, range −205 to 1821), for 3 was 1456 (IQR 634–1868, range 101–25452), for 4 was 887 (IQR 285–7481, range −1054 to 7481), and for 6 was 846 (IQR 57–1149, range −8 to 2309), (P < 0.001). For duration, the median change in CK for 5 s was 26.5 (IQR −8 to 109, range −1054 to 2309), for 10 s was 303 (IQR 34.5–1073, range −205 to 25452), and for 30 s was 47 (IQR 23–82, range −140 to 364), (P < 0.001). There was a relationship between the number of points of contact and the change in CK (P < 0.001) but not a relationship between the duration and the change in CK (P = 0.496). The median spread between the probe pairs for our pooled data was 40 cm, with a range from 18 to 70 cm (n = 76). The correlation between the change in CK and spread between the probe pairs was 0.16 at baseline (P = 0.18), and 0.24 at 24 h (P = 0.04) by Spearman’s rank correlation. ECD exposure can cause a modest increase in CK. Although we cannot draw conclusions about the individual devices included in this analysis, our findings indicated that multiple contact points or exposures may result in a larger increase in CK, but the duration of the exposure does not appear to have a significant effect on CK. There is a correlation between the distance between the probes and the change in CK.     

Carotid baroreceptors in fetal and newborn sheep

The responses of single carotid baroreceptor afferents were determined in anaesthetized fetal lambs at 88-113 and 131-144 days gestation, and in newborn lambs 1-8 and 30-40 days old. The baroreceptors discharged in synchrony with the arterial pressure pulse and increased their discharge rate as pressure was raised by compression of the abdominal aorta. When step increases in pressure were applied to the vascularly isolated carotid sinus, baroreceptor discharge increased abruptly and then showed adaptation to a steady state level. Basal mean arterial pressure increased from 49.1 in the young fetuses to 87.5 mm Hg in the 30- to 40-day-old lambs without an accompanying increase in basal baroreceptor discharge expressed absolutely or as a function of maximum discharge for each unit. The slope of the steep portion of the stimulus-response curve decreased with gestational age from 7.89 +/- 1.57 (mean +/- SE) at 88-113 days gestation to 1.82 +/- 0.37% nerve activity.mm Hg-1 in the 30- to 49-day-old lambs. Dynamic and steady state response curves were determined using step increases in carotid sinus pressure in two fetal lambs of 135 days gestation and two lambs 8 days old. Both the dynamic and the steady state curves were less steep in the older lambs. We conclude that the sensitivity of the carotid baroreceptors is reset as arterial pressure increases throughout the last third of gestation and the first postnatal month. This resetting is seen as a shift to the right of the response curve and a decrease in its slope.(ABSTRACT TRUNCATED AT 250 WORDS)