90 research outputs found
Quantitative anatomy of the posterior cricoid region
The anatomy of the posterior cricoid cartilage region was examined to obtain
a better quantitative understanding of this region. The mean height and width
of the posterior cricoid cartilage in the midline measured 24.5 mm and 25 mm
respectively. The mean distance between the fibres for the left and right posterior
cricoarytenoid muscles was 5 mm at the midpoint of the posterior cricoid
cartilage. The height of these muscles averaged 19 mm for left sides and 20 mm
for right sides. The mean distances from the midpoint and superior midline of
the posterior cricoid cartilage to the inferior laryngeal nerve were 14 mm and
15 mm respectively for left sides and 17 mm and 18 mm respectively for right
sides. It is hoped that these data will be of use to clinicians performing invasive
procedures in this area
The results of compression forces applied to the isolated human calvaria
Data for the force necessary to fracture the isolated calvaria (skull cap) are not
available in the extant literature. Twenty dry adult calvaria were tested to failure
quasistatically at the vertex using a 15-kN load cell. The forces necessary to
fracture or cause diastasis of calvarial sutures were then documented and gross
examination of the specimens made. Failure forces had a mean measurement of
2772 N. Initial fractures did not cross suture lines. Prior to complete destruction
of the calvaria there were 7 specimens in which all sutures of the calvaria became
diastatic, 6 specimens in which the calvaria became diastatic along only
the coronal sutures, 2 specimens in which the calvaria became diastatic along
only the sagittal suture and 5 specimens in which there were diagonal linear
parietal bone fractures. Our hopes are that these data may contribute to the
structural design of more safer protective devices for use in our society, assist in
predicting injury and aid in the construction of treatment paradigms
Does a third head of the rectus femoris muscle exist?
Current anatomical texts describe only two tendinous origins of the rectus femoris
muscle. The authors identified one older reference in which a third head of
the rectus femoris muscle was briefly described. In order to confirm the existence
of this head, 48 adult cadavers (96 sides) underwent detailed dissection of
the proximal attachments of the rectus femoris muscle. Of these sides 83%
were found to harbour a recognised third head of the rectus femoris muscle.
This additional head was found to attach deeply to the iliofemoral ligament and
superficially with the tendon of the gluteus minimus muscle as it attached into
the femur. This tendon attached to the anterior aspect of the greater trochanter
in an inferolateral direction compared to the straight head. The mean length
and width of the third head was 2 cm and 4 cm, respectively. The mean thickness
was found to be 3 mm. Most commonly this third head was bilaterally
absent or bilaterally present. However, 4.2% were found only on left sides and
5.2% were found only on right sides. The angle created between the reflected
and third heads was approximately 60 degrees. Two sides (both left sides with
one female and one male specimen) were found to have third heads that were
bilaminar. These bilaminar third heads had a distinct layer attaching to the underlying
iliofemoral ligament and a superficial layer blending with the gluteus
minimus tendon to insert onto the greater trochanter. Although the function of
such an attachment is speculative, the clinician may wish to consider this structure
in the interpretation of imaging or in surgical procedures in this region, as
in our study it was present on the majority of sides
Patent Human Infections with the Whipworm, Trichuris trichiura, Are Not Associated with Alterations in the Faecal Microbiota
Background: The soil-transmitted helminth (STH), Trichuris trichiura colonises the human large intestine where it may
modify inflammatory responses, an effect possibly mediated through alterations in the intestinal microbiota. We
hypothesised that patent T. trichiura infections would be associated with altered faecal microbiota and that anthelmintic treatment would induce a microbiota resembling more closely that observed in uninfected individuals.
Materials and Methods: School children in Ecuador were screened for STH infections and allocated to 3 groups: uninfected, T. trichiura only, and mixed infections with T. trichiura and Ascaris lumbricoides. A sample of uninfected children and those with T. trichiura infections only were given anthelmintic treatment. Bacterial community profiles in faecal samples were studied by 454 pyrosequencing of 16 S rRNA genes.
Results: Microbiota analyses of faeces were done for 97 children: 30 were uninfected, 17 were infected with T. trichiura, and 50 with T. trichiura and A. lumbricoides. Post-treatment samples were analyzed for 14 children initially infected with T. trichiura alone and for 21 uninfected children. Treatment resulted in 100% cure of STH infections. Comparisons of the microbiota at different taxonomic levels showed no statistically significant differences in composition between uninfected
children and those with T. trichiura infections. We observed a decreased proportional abundance of a few bacterial genera from the Clostridia class of Firmicutes and a reduced bacterial diversity among children with mixed infections compared to the other two groups, indicating a possible specific effect of A. lumbricoides infection. Anthelmintic treatment of children with T. trichiura did not alter faecal microbiota composition.
Discussion: Our data indicate that patent human infections with T. trichiura may have no effect on faecal microbiota but that A. lumbricoides colonisation might be associated with a disturbed microbiota. Our results also catalogue the microbiota of rural Ecuadorians and indicate differences with individuals from more urban industrialised societies
Extending colonic mucosal microbiome analysis - Assessment of colonic lavage as a proxy for endoscopic colonic biopsies
This study was supported through GI Research funds and MRC Grant Ref: MR/M00533X/1 to GH.Peer reviewedPublisher PD
Vesicular glutamate release from central axons contributes to myelin damage
Neuronal activity can lead to vesicular release of glutamate. Here the authors demonstrate that vesicular release of glutamate occurs in axons during ischemic conditions, and that an allosteric modulator of GluN2C/D is protective in models of ischemic injury
Acromioclavicular joint dislocation: a comparative biomechanical study of the palmaris-longus tendon graft reconstruction with other augmentative methods in cadaveric models
<p>Abstract</p> <p>Background</p> <p>Acromioclavicular injuries are common in sports medicine. Surgical intervention is generally advocated for chronic instability of Rockwood grade III and more severe injuries. Various methods of coracoclavicular ligament reconstruction and augmentation have been described. The objective of this study is to compare the biomechanical properties of a novel palmaris-longus tendon reconstruction with those of the native AC+CC ligaments, the modified Weaver-Dunn reconstruction, the ACJ capsuloligamentous complex repair, screw and clavicle hook plate augmentation.</p> <p>Hypothesis</p> <p>There is no difference, biomechanically, amongst the various reconstruction and augmentative methods.</p> <p>Study Design</p> <p>Controlled laboratory cadaveric study.</p> <p>Methods</p> <p>54 cadaveric native (acromioclavicular and coracoclavicular) ligaments were tested using the Instron machine. Superior loading was performed in the 6 groups: 1) in the intact states, 2) after modified Weaver-Dunn reconstruction (WD), 3) after modified Weaver-Dunn reconstruction with acromioclavicular joint capsuloligamentous repair (WD.ACJ), 4) after modified Weaver-Dunn reconstruction with clavicular hook plate augmentation (WD.CP) or 5) after modified Weaver-Dunn reconstruction with coracoclavicular screw augmentation (WD.BS) and 6) after modified Weaver-Dunn reconstruction with mersilene tape-palmaris-longus tendon graft reconstruction (WD. PLmt). Posterior-anterior (horizontal) loading was similarly performed in all groups, except groups 4 and 5. The respective failure loads, stiffnesses, displacements at failure and modes of failure were recorded. Data analysis was carried out using a one-way ANOVA, with Student's unpaired t-test for unpaired data (S-PLUS statistical package 2005).</p> <p>Results</p> <p>Native ligaments were the strongest and stiffest when compared to other modes of reconstruction and augmentation except coracoclavicular screw, in both posterior-anterior and superior directions (p < 0.005).</p> <p>WD.ACJ provided additional posterior-anterior (P = 0. 039) but not superior (p = 0.250) stability when compared to WD alone.</p> <p>WD+PLmt, in loads and stiffness at failure superiorly, was similar to WD+CP (p = 0.066). WD+PLmt, in loads and stiffness at failure postero-anteriorly, was similar to WD+ACJ (p = 0.084).</p> <p>Superiorly, WD+CP had similar strength as WD+BS (p = 0.057), but it was less stiff (p < 0.005).</p> <p>Conclusions and Clinical Relevance</p> <p>Modified Weaver-Dunn procedure must always be supplemented with acromioclavicular capsuloligamentous repair to increase posterior-anterior stability. Palmaris-Longus tendon graft provides both additional superior and posterior-anterior stability when used for acromioclavicular capsuloligamentous reconstruction. It is a good alternative to clavicle hook plate in acromioclavicular dislocation.</p
Sanitation and Health
As one article in a four-part PLoS Medicine series on water and sanitation, David Trouba and colleagues discuss the importance of improved sanitation to health and the role that the health sector can play in its advocacy
Extending colonic mucosal microbiome analysis—assessment of colonic lavage as a proxy for endoscopic colonic biopsies
- …