Forelimb muscle activation patterns in American alligators: Insights into the evolution of limb posture and powered flight in archosaurs.

The evolution of archosaurs provides an important context for understanding the mechanisms behind major functional transformations in vertebrates, such as shifts from sprawling to erect limb posture and the acquisition of powered flight. While comparative anatomy and ichnology of extinct archosaurs have offered insights into musculoskeletal and gait changes associated with locomotor transitions, reconstructing the evolution of motor control requires data from extant species. However, the scarcity of electromyography (EMG) data from the forelimb, especially of crocodylians, has hindered understanding of neuromuscular evolution in archosaurs. Here, we present EMG data for nine forelimb muscles from American alligators during terrestrial locomotion. Our aim was to investigate the modulation of motor control across different limb postures and examine variations in motor control across phylogeny and locomotor modes. Among the nine muscles examined, m. pectoralis, the largest forelimb muscle and primary shoulder adductor, exhibited significantly smaller mean EMG amplitudes for steps in which the shoulder was more adducted (i.e., upright). This suggests that using a more adducted limb posture helps to reduce forelimb muscle force and work during stance. As larger alligators use a more adducted shoulder and hip posture, the sprawling to erect postural transition that occurred in the Triassic could be either the cause or consequence of the evolution of larger body size in archosaurs. Comparisons of EMG burst phases among tetrapods revealed that a bird and turtle, which have experienced major musculoskeletal transformations, displayed distinctive burst phases in comparison to those from an alligator and lizard. These results support the notion that major shifts in body plan and locomotor modes among sauropsid lineages were associated with significant changes in muscle activation patterns.

Limb bone strains during climbing in green iguanas (Iguana iguana): testing biomechanical release as a mechanism promoting morphological transitions in arboreal vertebrates.

Across vertebrate diversity, limb bone morphology is typically expected to reflect differences in the habitats and functional tasks that species utilize. Arboreal vertebrates are often recognized to have longer limbs than terrestrial relatives, a feature thought to help extend the reach of limbs across gaps between branches. Among terrestrial vertebrates, longer limbs can experience greater bending moments that might expose bones to a greater risk of failure. However, changes in habitat or behavior can impose changes in the forces that bones experience. If locomotion imposed lower loads in trees than on the ground, such a release from loading demands might have produced conditions under which potential constraints on the evolution of long limbs were removed, making it easier for them to evolve in arboreal species. We tested for such environmental differences in limb bone loading using the green iguana (Iguana iguana), a species that readily walks over ground and climbs trees. We implanted strain gauges on the humerus and femur, and then compared loads between treatments modeling substrate conditions of arboreal habitats. For hindlimbs, inclined substrate angles were most correlated with strain increases, whereas the forelimbs had a similar pattern but of lesser magnitude. Unlike some other habitat transitions, these results do not support biomechanical release as a mechanism likely to have facilitated limb elongation. Instead, limb bone adaptations in arboreal habitats were likely driven by selective pressures other than responses to skeletal loading.

Ontogenetic changes in limb posture, kinematics, forces and joint moments in American alligators (Alligator mississippiensis).

As animals increase in size, common patterns of morphological and physiological scaling may require them to perform behaviors such as locomotion while experiencing a reduced capacity to generate muscle force and an increased risk of tissue failure. Large mammals are known to manage increased mechanical demands by using more upright limb posture. However, the presence of such size-dependent changes in limb posture has rarely been tested in animals that use non-parasagittal limb kinematics. Here, we used juvenile to subadult American alligators (total length 0.46-1.27 m, body mass 0.3-5.6 kg) and examined their limb kinematics, forces, joint moments and center of mass (CoM) to test for ontogenetic shifts in posture and limb mechanics. Larger alligators typically walked with a more adducted humerus and femur and a more extended knee. Normalized peak joint moments reflected these postural patterns, with shoulder and hip moments imposed by the ground reaction force showing relatively greater magnitudes in the smallest individuals. Thus, as larger alligators use more upright posture, they incur relatively smaller joint moments than smaller alligators, which could reduce the forces that the shoulder and hip adductors of larger alligators must generate. The CoM shifted nonlinearly from juveniles through subadults. The more anteriorly positioned CoM in small alligators, together with their compliant hindlimbs, contributes to their higher forelimb and lower hindlimb normalized peak vertical forces in comparison to larger alligators. Future studies of alligators that approach maximal adult sizes could give further insight into how animals with non-parasagittal limb posture modulate locomotor patterns as they increase in mass and experience changes in the CoM.

Genetic factors involves in intracranial aneurysms--actualities.

UNLABELLED: Intracranial aneurysm (IA) is a common vascular disorder, which frequently leads to fatal vascular rupture leading to subarachnoid hemorrhage (SAH). Although various acquired risk factors associated with IAs have been identified, heritable conditions are associated with IAs formation but these syndromes account for less than 1% of all IAs in the population. Cerebral aneurysm disease is related to hemodynamic and genetic factors, associated with structural weakness in the arterial wall, which was acquired by a specific, often unknown, event. Possibly, the trigger moment of aneurysm formation may depend on the dynamic arterial growth, which is closely related to aging/ atherosclerosis. Genetic factors are known to have an important role in IA pathogenesis. Literature data provide complementary evidence that the variants on chromosomes 8q and 9p are associated with IA and that the risk of IA in patients with these variants is greatly increased with cigarette smoking. Intracranial aneurysms are acquired lesions (5-10% of the population). In comparison with sporadic aneurysms, familial aneurysms tend to be larger, more often located in the middle cerebral artery, and more likely to be multiple. ABBREVIATIONS: DNA = deoxyribonucleic acid, FIA = familial Intracranial Aneurysm, GWAS = genome-wide association studies, IL-6 = interleukin-6, ISUIA = International Study of Unruptured Intracranial Aneurysms, IA = Intracranial aneurysm, mRNA = Messager ribonucleic acid, SNPs = single-nucleotide polymorphisms, SMCs = smooth muscle cells, sIAs = sporadic IAs, SAH = subarachnoid hemorrhage, TNF-α = tumor necrosis factor-alpha, COL4A1 = type IV collagen alpha-1.

[Treatment of aseptic ulnar non-union in a patient with spastic hemiparesis by Ilizarov method]. / Tratamentul pseudartrozei aseptice de cubitus prin metoda Ilizarov la un pacient cu hemipareza spastica.

Both-bone diaphyseal forearm fractures in children are common lesions. Non-union is very rare, almost exclusively in the ulna. We present a case of forearm fracture in a patient with spastic hemiparesis involving the injured forearm, treated initially with open reduction and intramedullary nailing. Ulnar deviation of both bones, with bending of intramedullary implants, occurred during postoperative period, due to spasticity of forearm flexors. An aseptic non-union of the ulna also developed. Both complications were treated by compression osteogenesis using a Ilizarov circular frame, the end results being excellent. The unusual and rare association between a preexisting neurologic spastic disorder and a forearm fracture can lead to malunion or/and nonunion, a more rigid method of initial osteosynthesis (locked compression plate) being an alternative in such cases.

[Caudal anesthesia in pediatric surgery]. / Anestezia caudala in chirurgia pediatrica. Experienta noastra pe 150 de cazuri.

UNLABELLED: The study analyses the efficacy and the safety of caudal anesthesia for the intra and postoperative pain management in children. MATERIAL AND METHOD: A retrospective study was conducted over a five years period enrolling 150 children scheduled for various surgical procedures. We used the standard technique ("loss of resistance", "single shot", lateral decubitus). RESULTS: The most important age groups were 1 month - 1 year, 64 cases (42.66%) and 1-6 years - 71 cases (47.33%). We performed 144 caudal blocks associated with general anesthesia, 3 associated with sedation and 3 simple caudal blocks. In 129 cases, we used bupivacaine 0.25% as a single analgetic substance, in five cases bupivacaine 0.25% with lidocaine 1%, and in 16 cases bupivacaine 0.25% with fentanyl 1 mcg/kg. The quality of the analgesia was very good in 128 cases (85.33%), good in 12 (8%) and poor in 10 cases (6.66%). The morbidity rate was 13.33% (20 cases), the most frequent complication being urinary retention (8 cases - 5.33%). CONCLUSIONS: The caudal block is an efficient procedure for intra and postoperative analgesia in children. Associated with general anesthesia it is very useful for the management of the age groups 1 month - 1 year and 1-6 years.

[Congenital oropharyngeal tumors in the newborn: problems in team diagnosis and treatment]. / Tumori congenitale cu localizare orofaringiana la nou nascut: probleme de diagnostic si tratament în echipa.

There are a great variety of lesions of oral cavity which may require surgical intervention in neonatal period. The differential diagnoses include tumors (malignant, teratoma, cystic hygroma, lymphangioma, hemangioma), congenital epulis, dermoid cysts, ranula. Congenital epulis of the newborn is a rare tumour which is usually benign. Epulis is also known as a congenital gingival granular cell tumour because of its histological features. Female babies are affected 8-10 times more often than males. Epulis is located on the maxillary ridge twice as often as on the mandible, mostly as single tumours but rarely as multiple tumours. The histogenesis of the tumour is unknown. Spontaneous regression of congenital epulis has been reported in a few cases. However, surgical excision is generally indicated due to interference with feeding or respiration. Recurrence of the tumour after surgery has not been reported yet. We report two cases of congenital epulis, one in 2 hour female neonate and one in a 7 days male neonate. In spite of the rarity of this pathology, the interval between presentation in this two cases was ten days. In one case it was an antenatal diagnosis by ultrasonography, in the other it was associated a genital anomalies (hypospadias). The treatment was surgical excision. The intra- and postoperative course was uneventful.

[The results of the Sommerville-Petit procedure in the treatment of the typical congenital hip dislocation]. / Rezultatele metodei Sommerville-Petit în tratamentul luxatiei congenitale tipice a soldului.

The studied group from the Pediatric Surgery and Orthopedics Clinic, Iasi, consisted of 87 cases, which means that a total of 118 hips were treated between September 1998-September 2004. In 116 cases, the extension was performed with trans-femoral Kirschner wire, in a period of 3-7 weeks. After 7-14 days of extension, the authors performed adductor and sometimes psoas tenotomy. The stable orthopedic reduction was obtained in 34 hips, while the 15 cases with inadequate results required open reduction. This method, performed from the beginning after a period of extension, was applied to 69 cases. In 13 patients the iterative open reduction was required. None of the cases associated femoral diaphysis shortening resection.

[Indications for esophageal replacement in children]. / Indicatiile esofagoplastiei la copil.

Esophageal substitution in children is required in several types of esophageal atresia, as well as following strictures caused by caustic ingestion or peptic esophagitis. Nowadays, two main types of procedures are used for esophageal replacement: colon segment esophagoplasty (that seems to be preferred by most pediatric surgeons) and gastric tube esophagoplasty. The paper presents the personal experience in the management of a series of 56 children with esophageal replacement, during the last 10 years. In 46 patients, the stricture cause was caustic ingestion, while peptic esophagitis accounted for 3 cases. The remaining 7 cases were long-gap esophageal atresias that could not be managed by primary neonatal anastomosis. The results are rated as good in 42 cases. Complications occurred in 13 cases, while fatal outcome occurred in 5 patients. The most remarkable feature of the series is the high number of procedures required after caustic ingestion.

Complications following gastric tube esophagoplasty in children.

Surgery in children with caustic esophageal burns, esophageal atresia or other esophageal disorders can be performed using gastric tube esophagoplasty. Between 1991 and 1999, a number of 41 such procedures have been performed in our department, using the original technique developed by Gavriliu. The results were assessed as good and very good in 83% of the cases, and fair or bad in the rest of 17%. We recorded 13 cases with significant complications, 4 of which ended with exitus. The paper present our experience in using gastric tube esophagoplasty and the management of the complications related to this procedure.

[Primary obstructive megaureter- diagnosis and treatment]. / Modalitati de diagnostic si tratament în megaureterul primar obstructiv.

The authors have treated 13 cases of primary obstructive megaureter (POM) in children, presenting without vesicoureteric reflux. The diagnostic possibilities and the surgical approach options are discussed. Both Cohen and Leadbetter--Politano uretero-vesical reimplantation techniques proved to be successful in this series. Ureteric folding was done in 2 cases. Reported final results are good in 10 cases.

[Achalasia in children: Diagnostic opportunities and therapeutical options]. / Acalazia cardiei la copil--posibilitati diagnostice si optiuni terapeutice.

Achalasia is a functional disorder of the distal esophagus, which fails to relax during swallowing. Although being rare, this disorder is the source of a significant morbidity, including developmental disorders in children. Several therapeutical options are available: myorelaxants administration, esophageal dilations and surgery--distal esophageal myomectomy followed by an antireflux procedure. The paper introduces our experience in treating a number of 5 children between 1991 and 1998.

[The results of the Ravitch-Sutherland technic for surgical correction in pectus excavatum]. / Rezultate dupa tehnica Ravitch-Sutherland pentru corectia chirurgicala în pectus excavatum.

The aim of our study was to assess the functional and cosmetic results after performing a modified Ravitch-Sutherland procedure in children presenting with excavatum. A series of 31 children with ages ranging between 5 and 16 years, presenting with pectus excavatum, were operated between 1986-1996 in our service. In 5 cases surgical treatment was required by the presence of respiratory and/or cardiac functional impairment due to the malformation. In the other 23 cases operation was performed mainly for cosmetic reasons. In all cases a modified Ravitch-Sutherland procedure was performed. Modification consisted in renouncing at the plicature of the perichondra and in associating a diaphragmatic elongation and Bedouelle laparoplasty in all cases. Longitudinal sternotomy was performed in 2 cases with severely impaired ventilatory capacity. Functional and cosmetic results were good in all cases. In 2 cases, in which recurrence of the condition was observed, a second identical procedure was performed, with a good result. The interval between the operation and the moment of long-term evaluation ranged between 3 months and 11 years. We conclude that the modified Ravitch-Sutherland procedure represents an effective method for the treatment of pectus excavatum cases, offering good functional and cosmetic long-term results.

[The results of the Ravitch-Sutherland technic for surgical correction in pectus excavatum]. / Rezultate dupa tehnica Ravitch-Sutherland pentru corectia chirurgicala în pectus excavatum.

The aim of our study was to asses the functional and cosmetic results after performing a modified Ravitch-Sutherland procedure in children presenting with pectus excavatum. A series of 31 children with ages ranging between 5 and 16 years, presenting with pectus excavatum, were operated between 1986-1996 in our service. In 5 cases surgical treatment was required by the presence of respiratory and/or cardiac functional impairment due to the malformation. In the other 23 cases operation was performed mainly for cosmetic reasons. In all cases a modified Ravitch-Sutherland procedure was performed. Modifications consisted in renouncing at the plication of the perichondrium and in associating a diaphragmatic elongation and Bedouelle laparoplasty in all cases. Longitudinal sternotomy was performed in 2 cases with severely impaired ventilatory capacity. Functional and cosmetic results were good in all cases. In 2 cases, in which recurrence of the condition was observed, a second identical procedure was performed, with a good result. The interval between the operation and the moment of long-term evaluation ranged between 3 months and 11 years. We conclude that the modified Ravitch-Sutherland procedure represents an effective method for the treatment of pectus excavatum cases, offering good functional and cosmetic long-term results.

The ileal diverticulum. Morpho-clinical and epidemiological study.

In two autopsy prospective studies, at the Prosectures of the Departmental Hospital and of the Pediatric Hospital in Cluj, we found an incidence of Meckel's diverticulum of 1.16%, 1.46% respectively. Besides, we have retrospectively followed the incidence of the ileal diverticulum during the laparatomies performed at the Pediatric Hospital in Cluj between 1981 and 1990 on an acute abdomen of a supposed appendicular cause. Consulting the pathological bulletins which registered 8,385 laparatomies we found 200 Meckel's diverticula. Of the 200 diverticula, 64 exhibited a pathological process and 136 were trophic, and we suppose that they were found incidentally (incidence of 1.63%, corrected incidence of 1.38%). Up to the age of 16, 4.5% of the diverticula were excised. In the 64 symptomatic cases of ileal diverticulum, 50 presented inflammatory complications, 10 were ulcero-hemorrhagic, two were obstructive, one diverticulum presented an entero-umbilical fistula and one displayed a hemorrhagic infarction. Seventeen of the 200 diverticula presented heterotopic tissues; 12 of the 17 cases were symptomatic; in 64.7% of the cases the heterotopic tissue was the gastric mucous coat. Out of 8,385 laparatomies performed on an acute abdomen of a supposed appendicular cause, in 64 cases the symptomatology was generated by a meckelian pathological process (0.76%). An acute appendicitis was concomitantly present in 22 of the 64 cases.

Detection of Bacteroides fragilis group by immunofluorescence.

The following strains: B. fragilis subspecies thetaiotaomicron (A); B. fragilis subspecies fragilis strain E-1, E-2, M, St., Se., Ni., 8, 16; B. fragilis subspecies distasonis 145 (D) were serologically studied by immunofluorescence as compared to agglutination. Anti-B. fragilis sera titration by immunofluorescence (IF) reaction, as compared to agglutination reaction in tube, was more sensitive (2-16 times higher titers), specific and reproducible. Among the organisms from B. fragilis group, species, subspecies and even train specificity was noticed. Also, the possibility for rapid identification of anaerobic organisms, belonging to B. fragilis group, in pathologic products obtained from experimentally infected animals (mice and rats), by IF reaction, in comparison with classic methods (anaerobic cultures and biochemical determinations) was studied. Of 87 studied animals, 61 proved positive by cultures and 59 by IF; 56 animals were shown positive and 23 animals proved negative by both methods (intermethods concordance in 79 cases). Statistical analysis of IF results provided the following: method sensitivity (detection capacity of real-positive cases)-91.80%; method specificity (detection capacity of real-negative cases)-88.46%; false-positive cases-11.53%; false-negative cases-8.19%. Immunofluorescence proved specific, sensitive, practical and rapid method detection of non-sporulated anaerobic organisms species and subspecies belonging to Bacteroides fragilis group.