Role of the mesenteric arteries in the arterial blood supply to the lower limbs

Summary The arteries of the gut, and in particular in the inferior mesenteric artery (a. mesenterica inferior), normally play a minimal role in supplying blood to the lower limbs. However, this is far from being the case in aorto-iliac obstruction. The anatomical anastomoses between the intestinal arterial system and the arteries of the lower limb hypertrophy and in one case out of ten become predominant.In the present study the path taken and the relations of the collaterals of the intestinal arteries and of their anastomoses have been traced, and several collateral pathways are described.

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Rôle des artères mésentériques dans la revascularisation artérielle des membres inférieurs

Résumé Les artères digestives, et en particulier l'artère mésentérique inférieure (a. mesenterica inferior), jouent à l'état normal un rôle minime dans la vascularisation des membres inférieurs. Il n'en est pas de même en cas d'oblitération aorto-iliaque. Les anastomoses anatomiques entre le système artériel digestif et les artères du membre inférieur s'hypertrophient et, dans un cas sur 10, deviennent prédominantes.Dans cette étude, le trajet et les relations des collatérales des artères digestives et leurs anastomoses sont étudiés. Plusieurs voies collatérales sont possibles.

     

‘Elastic length’ of the female urethra—initial measurements

An elasticity parameter known as the elastic length of the urethra was derived from a theory of flow presented in a previous article. The suggestion was made that a consideration of this parameter could be relevant to an understanding of the flow of urine through the urethra. The present short paper presents an account of initial measurements of the elastic length for two females. It seems likely that we cannot neglect the elastic length when considering flow through the urethra.     

Poland anomaly with a limb body wall disruption defect: Case report and review

We describe a female infant with apparent Poland anomaly (PA) and limb body wall defect. Analysis of the defects suggest that a disruption of the lateral embryonic plate mesoderm may have been responsible for the observed lesions. Because of the overlap of this case with PA, we re-examined previous reports of this syndrome. We think that the lesions could be equally well explained as a mesodermal disruption, and point out a previously unrecognised discrepancy between sex and affected side in sporadic PA and inherited PA which supports this view. © 1992 Wiley-Liss, Inc.     

Mathematical modelling of the growth processes in the developing chick wing bud

This paper illustrates how a simple geometric model resembling the shape of the chick wing bud at an early growth stage can be mathematically expanded to simulate subsequent growth characteristics of the developing bud. The model was tested against several sets of experimental data and gave an acceptable representation of growth over the range considered. Representing growth patterns in this form enables the determination of differential growth characteristics in different parts of the bud and provides boundary constraints which will play an important part in the eventual evaluation of internal growth mechanisms.     

骨骺牵张与骨骺板的生物力学性质

本研究是对新西兰幼兔股骨远端骨骺进行体内和体外牵张实验.16只兔右股骨经5～10N力每3天一次牵张.4周后的股骨长度值明显大于左侧和0N组.形态学变化是受牵张的骺板增厚,软骨细胞增殖且无骨骺分离骨折.体外骺板抗断裂测试显示夸张后的骺板强度不低于未经牵张的对照侧.8只动物16根股骨于体外接受20～100N力的牵张,其骺板的塑性变形度随牵张力值的增高而增大,抗断裂强度亦不低于未经牵张的骨骺.这些结果表明适量的牵张力和/或低牵张速率是实现“软骨分离”或骨延长的关键.     

Restriction site polymorphism at the LPA (Lp(a) apoliprotein; apoliprotein(a)) locus

A restriction site polymorphism in the Lp(a) apolipoprotein gene (the LPA gene) is reported. The basis for the polymorphism is presence or absence of an MspI restriction site that appears to be 3' to the last kringle IV structure of the gene. The "1" gene (presence of the restriction site) has a frequency of 0.316 and the "2" gene (absence of the restriction site) has a frequency of 0.684. Both members of each of 67 monozygotic (MZ) twin pairs had the same genotype and there was Mendelian segregation of the DNA variants in 40 families with a total of 75 children. There was a lower proportion of people with genotype 1-1 in the top quartile than in the 3 bottom quartiles of the population distribution of Lp(a) lipoprotein levels but the difference did not reach statistical significance.     

Public health impact of isoniazid-resistant Mycobacterium tuberculosis strains with a mutation at amino-acid position 315 of katG: a decade of experience in The Netherlands

A previous limited study demonstrated that Mycobacterium tuberculosis isolates with a mutation at amino-acid position 315 of katG (Delta315) exhibited high-level resistance to isoniazid and were more frequently resistant to streptomycin. In the present study, isoniazid-resistant M. tuberculosis isolates from 8,332 patients in The Netherlands (1993-2002) were screened for the Delta315 mutation. Isoniazid resistance was found in 592 (7%) isolates, of which 323 (55%) carried Delta315. IS6110 restriction fragment length polymorphism analysis showed that Delta315 isolates occurred in clusters, suggesting recent transmission, at the same frequency as isoniazid-susceptible isolates. In contrast, other isoniazid-resistant isolates clustered significantly less frequently. Delta315 isolates were high-level isoniazid-resistant, streptomycin-resistant and multidrug-resistant significantly more often, and may have a greater impact on public health, than other isoniazid-resistant isolates.     

Molecular and biological analysis of echovirus 9 strain isolated from a diabetic child

The full-length infectious cDNA clone was constructed and sequenced from the strain DM of echovirus 9, which was recently isolated from a 6-week-old child at the clinical onset of type 1 diabetes. Parallel with the isolate DM, the full-length infectious cDNA clone of the prototype strain echovirus 9 Barty (Barty-INF), was constructed and sequenced. Genetic relationships of the sequenced echo 9 viruses to the other members of the human enterovirus type B species were studied by phylogenetic analyses. Comparison of capsid protein sequences showed that the isolate DM was closely related to both prototype strains: Hill and Barty-INF. The only exception was the inner capsid protein VP4 where serotype specificity was not evident and the isolate DM clustered with the strain Hill and the strain Barty-INF with echovirus 30 Bastianni. Likewise, the nonstructural protein coding region, P2P3, of isolate DM was more similar to strain Hill than to strain Barty-INF. However, like echovirus 9 Barty, the isolate DM contained the RGD-motif in the carboxy terminus of capsid protein VP1. By blocking experiments using an RGD-containing peptide and a polyclonal rabbit antiserum to the alpha(v)beta(3)-integrin, it was shown that this molecule works as a cellular receptor for isolate DM. By using primary human islets, it was shown that the isolate DM is capable of infecting insulin-producing beta-cells like the corresponding prototype strains did. However, only isolate DM was clearly cytolytic for beta-cells. The infectious clones that were made allow further investigations of the molecular features responsible for the diabetogenicity of the isolate DM.     

The effects of distant and on-line visual information on the control of approach phase and step over an obstacle during locomotion

One of the goals of this study was to examine the nature and role of distant visual information sampled during locomotion in the feedforward control of leading and trailing limb while an individual is required to step over an obstacle in the travel path. In addition we were interested in whether or not on-line visual information available while the limb (lead or trail) is stepping over the obstacle influences limb trajectory control and whether the information provided during lead limb cross would be used to calibrate movement of the trail limb. Towards this end, we manipulated availability of vision following an initial dynamic sampling period during the approach phase in proximity to the obstacle and during the lead and trail limb stepping over the obstacle. Ten participants completed 40 trials of obstacle crossing in 8 testing conditions. Initial dynamic visual sampling was sufficient to ensure successful task performance in the absence of vision in the approach phase and during both lead and trail limb stepping over the obstacle. Despite successful task performance, foot placement of the lead and trail limb before obstacle crossing and limb elevation over the obstacle were increased after withdrawal of vision in the approach area. Furthermore, the correlation between toe clearance and foot placement was diminished. While both limbs require feedforward visual information to control the step over the obstacle, only lead limb elevation was influenced by availability of on-line visual information during obstacle crossing. Results were in agreement with the notion of primacy of information inherent in the optic array over those from static samples of the environment in guiding locomotion. It is suggested that the expected proprioceptive feedback information associated with the limb posture before the obstacle, reconstructed using visual memory from dynamic sampling of the environment, mismatched with those from the actual limb position. Accordingly, participants adopted a different strategy that enabled them to clear the obstacle with a higher safety margin.Financial assistance was provided by a grant from the Office of Naval Research, USA, NSERC/Canada, and CAPES/Brazil. We would like to thank Milad G. Ishac, Mike Greig, Zinat Shafaei-Shirazi, and Candida T. Goncalves for their assistance     

The goniomaxillar length/goniomandibular length ratio in normal newborn infants: A clinical tool for defining chin position abnormalities

Retrognathia (recessed chin) and prognathism (prominent chin) often present as signs of an underlying condition. Accurate clinical definitions are important. Yet their definitions were according to “clinical impression”, or to seldom used X‐ray criteria. We propose a statistical and anthropometric definition of retrognathia and prognathism based upon the ratio between the goniomaxillar length (distance between the gonion at the mandible angle and the subnasale and the goniomandibular length (distance between the mandible angle and the most anterior point of the bony chin). We assumed that an increase in the ratio indicates retrognathia and a decrease reflects prognathism. We conducted a prospective, observational, anthropometric study in 204 consecutive healthy term infants. Measurements took place on the second day of life, using sliding calipers. Mean ± SD of goniomandibular length (5.1 ± 0.3 cm), goniomaxillar length (5.4 ± 0.3 cm), were calculated. All measurements correlated significantly with gestational age, and with infant birthweight. The mean ± SD goniomaxillar length/goniomandibular length ratio was 1.06 ± 0.05. We defined a normal ratio as being within 2 SD of the mean, that is, between 0.96 and and 1.16. This ratio correlated with neither gestational age nor with birthweight. We conclude that the goniomaxillar length/goniomandibular length ratio can be calculated whenever retro ‐ or prognathism is suspected. A ratio outside of the 95% confidence interval should help in making this diagnosis. An increase in this ratio beyond 2 SD above the mean (1.16) could be interpreted as retrognathia and a decrease beyond 2 SD below the mean (0.96) as prognathism.