Gaits of monkeys and horses: A methodological critique

In a previous paper it was shown that the traditional methodology used to analyze quadrupedal gaits is inadequate when applied to the gaits of monkeys. The traditional methods were modified for use with the monkey sample (Prost, '65). Was the modification a general improvement of the traditional approach or was it dictated by peculiarities of monkey locomotion? The traditional analysis receives its support primarily from its usefulness in handling horse gaits. If it can be shown that the modified methods improve the analysis for horses, then it can be claimed that the system is not a special case designed uniquely for use with monkeys. Motion pictures were taken of an American Saddle Bred, five-gaited horse performing several classic gaits. The films were analyzed using the modified methods developed to analyze monkey gaits. The analysis was superior to the traditional approach. All of the organizing principles which structure horse gaits were found to be identical to those which structure monkey gaits.     

On-line control of atracurium induced muscle relaxation

We described recently a microcomputer system capable of controlling muscle relaxation during surgical procedures; the system was tested and evaluated in 42 clinical trials involving the use of the muscle relaxant, d-tubucurarine. The advent of new non-depolarizing neuromuscular blocking drugs with significant clinical advantages makes it essential that any automatic control system for muscle relaxation can also be used with such drugs, and benefit from their improved properties. This paper describes a series of 22 clinical trials in which our controller was used successfully to control muscle relaxation using atracurium. We also investigated an alternative control strategy, taking advantage of the rapid elimination of atracurium from the body.     

心脏手术风险评估欧洲系统在OPCAB术后ICU中的应用

现在对于不停跳冠脉旁路移植术(OPCAB)的患者术后的预测的模型有很多种,这些模型大多用于预测术后死亡率、术后并发症,手术方式的选择、手术资源的应用价值的评估等。心脏手术风险评估欧洲系统(Euro SCORE)也是其中一种,它对于现代OPCAB术后死亡率的预测比较合理。但是随着手术外科的发展,Euro SCORE模型在中、低危组过高估计术后的死亡率,而在高危组又过低估计术后死亡率。此外,Euro SCORE模型也应用于预测术后并发症、住院费用多少、在ICU住院时间及机械通气时间,得到广泛应用,并在世界范围内得到推广,包括欧美等国家。最近在中国,也开始对心脏手术风险评估欧洲系统大量了的数据研究,并发展到对其他手术术后的预测及治疗。     

OBITUARIES

Thirty-three patients with heart block were treated by implantation of a permanent transvenous pacemaker. There were no deaths and few complications even though 25 of these patients were over 70 years of age. Follow-up examinations, including electrocardiograms, were done in all patients.The technique of the operation is discussed and the importance of performing it under fluoroscopic guidance in a proper surgical operating suite is emphasized. This arrangement may require the use of a portable image intensifier.This simple, effective procedure can be performed under local anesthesia and with safety, even in the elderly, frail or debilitated patient. Currently it is the authors'' method of choice in the treatment of heart block; thoracotomy is now obsolete unless a synchronous pacemaker is needed or a permanent transvenous pacer cannot be inserted.     

Minimally invasive surgery. Neurosurgery.

The introduction of minimally invasive techniques has greatly improved results for intracranial neurosurgery. Stereotaxy and improved imaging techniques have reduced surgical trauma by allowing surgeons to plan the least damaging route to operative sites and by increasing surgical precision. Stereotaxy has also allowed brain biopsies to be taken from sites such as the brain stem, which were rarely sampled before because free hand biopsy was so dangerous. Brain tumours can now be treated by interstitial radiotherapy--stereotactic insertion of catheters into the lesion for loading of radioactive iodine--or radiosurgery--focusing of intense beams of radiation on lesions without needing surgical incisions. Endoscopic neurosurgery can be used to reach cavities such as the ventricular system or cystic tumours. With interventional neuroradiology fine catheters can be introduced into most vessels in the cranium for embolisation or dilatation. The development of augmentative functional neurosurgery means that movement disorders, epilepsy, and intractable pain can be treated with implanted neurostimulating electrodes. Future developments will probably include frameless stereotaxy, when the rigid attachment of stereotactic apparatus to the patient''s head can be dispensed with, and at least partial automation of procedures such brain biopsy.     

PULMONARY RESECTION IN TUBERCULOSIS

Newer surgical and anesthetic techniques and the use of streptomycin and para-aminosalicylic acid (PAS) have made possible increased success in pulmonary resection for tuberculosis. Especially in early cases, however, bed rest and pneumothorax or pneumoperitoneum should be given adequate trial before resection is decided upon. In all cases a thorough bronchoscopic examination should be made first and the findings carefully evaluated.Pulmonary resection may be advisable for lesions of certain kinds which do not respond well to thoracotomy; for lesions which have not responded to trial of other methods; for a lung destroyed by tuberculosis; and in cases of active disease in an unexpanded lung.The experience of the author and of others emphasizes the importance of correct postoperative care. Since tuberculosis is rarely limited to the resected area, at least six months'' rest in bed under medical supervision is necessary to permit cure of residual disease. Streptomycin with PAS is particularly valuable in the postoperative period; therefore indiscriminate use of it in earlier treatment should be avoided lest resistance develop.     

Paracrine Effect of Mesenchymal Stem Cells Derived from Human Adipose Tissue in Bone Regeneration

Mesenchymal stem cell (MSC) transplantation has proved to be a promising strategy in cell therapy and regenerative medicine. Although their mechanism of action is not completely clear, it has been suggested that their therapeutic activity may be mediated by a paracrine effect. The main goal of this study was to evaluate by radiographic, morphometric and histological analysis the ability of mesenchymal stem cells derived from human adipose tissue (Ad-MSC) and their conditioned medium (CM), to repair surgical bone lesions using an in vivo model (rabbit mandibles). The results demonstrated that both, Ad-MSC and CM, induce bone regeneration in surgically created lesions in rabbit''s jaws, suggesting that Ad-MSC improve the process of bone regeneration mainly by releasing paracrine factors. The evidence of the paracrine effect of MSC on bone regeneration has a major impact on regenerative medicine, and the use of their CM can address some issues and difficulties related to cell transplants. In particular, CM can be easily stored and transported, and is easier to handle by medical personnel during clinical procedures.     

Using stage‐based system dynamics modeling for demographic management of captive populations

Management of captive populations relies on a complex synthesis of genetic and demographic analyses to guide populations toward sustainability. Demographic analyses of captive populations currently utilize age‐based matrix projections to predict a population's trajectory. An alternate approach is to use a stage‐based, system dynamics model for captive systems. Such models can more easily incorporate complex captive systems in which population dynamics are dependent on a combination of management and a species' biology. By linking these two areas, population managers can gain a more accurate understanding of how management decisions impact captive populations and which aspects of a species' demography should be of special concern in the future. We present a general stage‐based system dynamics model that has been developed for use with captive populations. The utility of the model is then illustrated by applying it to three captive bear populations: spectacled bears (Tremarctos ornatus), sloth bears (Melursus ursinus), and sun bears (Helarctos malayanus). Zoo Biol 22:45–64, 2003. © 2003 Wiley‐Liss, Inc.     

Dupuytren's Contracture of the Fingers—A Simplified Approach to Surgical Treatment

Hematoma formation, delay in healing, pain, stiffened finger joints are complications that sometimes follow classical surgical approaches to Dupuytren''s contracture. A new surgical approach to the disease that can correct the contractures without the attendant morbidity is urgently needed. By treating Dupuytren''s as any other scar contracture (division of the contracting soft tissue at its point of maximal tension and interposing normal free full-thickness skin) postoperative morbidity can be greatly decreased. Full return of function was achieved within 21 days following operation in 85 percent of the cases in which finger contractures were present before operation. Contracture release of 100 joints was done by this means, with loss of only one graft and without recurrence of the disease. This technique offers simple surgical control of progressive and recurrent Dupuytren''s contracture of the fingers with minimal postoperative morbidity.     

Practical low cost stand/sit system for midthoracic paraplegics

The use of functional electrical stimulation (FES) to enable paraplegics to stand is not new or indeed difficult to undertake under laboratory conditions. However, there are substantial problems to overcome before such systems can be used routinely by patients without professional supervision. The overriding consideration has to be one of safety, i.e. the system must be ‘fail safe’. Secondly, the system must be quick and easy to use in a wide variety of locations, otherwise it will not provide any increase in function. Finally, it must be inexpensive enough to be available to a large number of paraplegics. The primary aim of our work was to provide such a system to enable mid-thoracic lesion paraplegics to stand wherever they wish. This involved the development of a microprocessor-based stimulator to enable the stimulating envelope to be individually tailored to a given patient's requirements and the provision of closed loop control to minimize fatigue. A folding standing frame was also designed which replaces the arm rests on a standard wheelchair. Using this system, the user is able to stand within 30 s of stopping and can remain standing for up to 10 min. Cosmetic calipers (knee-ankle-foot orothoses) are also being used for paraplegics who require to stand for longer periods. It is hoped that such a system will provide stable standing for a large number of paraplegics at a unit cost of approximately £750.     

A benign method for maintaining ovulatory estrogen levels in cycling rhesus macaques

The goal of this study was to develop a relatively noninvasive technique for generating ovulatory estrogen levels in cycling females over extended periods of time. Eleven intact cycling rhesus macaques were given weekly injections of estradiol cypionate in an effort to obtain weekly levels which approximated ovulatory levels. A dose of 500 μg generated weekly estrogen values averaging 370 ± 18 pg/ml. This method is a satisfactory alternative to more traditional techniques. It involves no surgical procedures, it is relatively nonintrusive, it does not terminate a female's reproductive career, and it is not as time-consuming as daily injections. Female cycle state can be altered with a minimum of manipulation for studies involving the behavior of estrous females.     

Discrete colour polymorphism in the tawny dragon lizard (Ctenophorus decresii) and differences in signal conspicuousness among morphs

Intraspecific colour variation is common in nature and can vary from the coexistence of discrete colour variants in polymorphic species to continuous variation. Whether coloration is continuous or discrete is often ambiguous and many species exhibit a combination of the two. The nature of the variation (discrete or continuous) has implications for both the genetic basis of the colour variation and the evolutionary processes generating and maintaining it. Consequently, it is important to qualify the existence of discrete morphs, particularly in relation to the animal's visual system. In this study, we quantified male throat colour variation in Ctenophorus decresii tawny dragon lizard and tested for morphological and ecological correlates of the colour variants. We confirmed that discrete throat colour morphs can be defined based on colour and pattern analyses independent of the human visual system. We also found that the colour variants differed in their conspicuousness from the background, to the lizard's visual system, which has implications for signalling. However, the morphs did not differ in morphology or microhabitat use, which suggests that these characteristics are not involved in the evolutionary maintenance of the polymorphism.     

Das Triplett aus zwei Monophyla und einem Paraphylum als Baustein des phylogenetischen Systems

The triplet consisting of two monophyletic taxa and one paraphyletic taxon as constructive element of the phylogenetic system Evolution has produced very many novelties (apomorphies). Most of them are small and relatively inconstant, these are more or less indicative of the phylogenetic relationships between closely related species. They cannot be the constitutive character of a supraspecific taxon that exists since a long time and comprises many diversified species. Such a taxon of higher rank can only be characterized by an improbable, rare novelty that has developed only once and has been preserved in all descendent species. Two consecutive apomorphies of this persistent type (‘fixed apomorphies’) characterize three supraspecific taxa, the triplet “A”, “B” and “A minus B” (Fig. 1). The group “A minus B” is rejected in Hennig's theory because it is ‘paraphyletic’, but it is not an artefact created by the systematicist. It is an inevitable mathematical consequence of the differentiatison of the group “B” within the group “A”. Being the result of a subtraction, it is necessarily associated with the two monophyletic partners in the triplet, as it is delimited on one side by the synapomorphy of the group “A”, of which it is a part, and on the other side by the autapomorphy of the separate group “B”. Traditional classifications often include paraphyletic groupings that are inconsistent with phylogenetics, e. g. the Reptilia and the Apterygota. The fault in such cases is that these groups are extended beyond the limits of a triplet and cover more than a single interval between consecutive monophyletic taxa. Paraphyletic groups are admitted in the phylogenetic system only for bridging the gaps in our cladistic information. According to HENNIG'S theory, all supraspecific taxa should be arranged two by two as sister-groups originating from one ancestral species and comprising all descendents of that species. The fixed evolutionary novelties which characterize higher supraspecific taxa are, however, rare and scattered. It is highly improbable that they have developed in sister species, therefore the taxa marked by them cannot be sister-groups (except in very rare cases). In HENNIG'S earlier papers, e. g. in his system of Lepidoptera (1953: 46–49), the alleged ‘sister-groups' are, in reality, the groups “B” and “A minus B” of a triplet (see Fig. 2). In his revised concept (1957 and later), two autapomorphic groups which are most closely related in the recent fauna (“B” and “C” in Fig. 3) are called ‘sister-groups’. But these have originated independently from different ancestors in a plesiomorphic complex of extinct species and are more closely related to parts of this complex than to each other. True sister-groups (“Bx” and “Cx” in Fig. 4) would be formed if these related plesiomorphic species were included, but this extension of the ’backward‘ border of the taxon is not justified by synapomorphy (in the terms of logic, it is a ’metabasis‘), and it would make the classification of fossil species impossible, unless these show at least one synapomorphy with either “B” or “C”. In the system of the recent fauna the sister-groups are identical with the autapomorphic groups, because the plesiomorphic species are extinct. The natural system based on synapomorphies and autapomorphies is the triplet-system as outlined in Figure 6. It is not a new type of classification, but its theoretical foundation was missing, and precise instructions were needed for its use in phylogenetics. The information obtained by HENNIG'S method is entirely preserved in this system and can be retrieved from it, and both recent and extinct species can be classified together. The disadvantage of the triplet-system is that it contains twice as many taxa as HENNIG'S classification. This complexity will limit its use in the practice of taxonomy, but it may be simplified by transforming the system into a sequence of paraphyletic taxa terminating in a single monophylum.     

THE DARK ADAPTATION OF THE EYE OF THE HONEY BEE

Bees which are held in a fixed position so that only head movements can be made, respond to a moving stripe system in their visual field by a characteristic motion of the antennae. This reflex can be used to measure the bee''s state of photic adaptation. A curve describing the course of dark adaptation is obtained, which shows that the sensitivity of the light adapted bee''s eye increases rapidly during the first few minutes in darkness, then more slowly until it reaches a maximum level after 25 to 30 minutes. The total increase in sensitivity is about 1000 fold. The adaptive range of the human eye is about 10 times greater than for the bee''s eye. The range covered by the bee''s eye corresponds closely to the adapting range which is covered by the rods of the human eye.     

Catheter Ablation of Hemodynamically Unstable Ventricular Tachycardia in a Patient with Dextro - Transposition of the Great Arteries and Mustard's Repair

Introduction

A patient with D-TGA and surgical repair (Mustard''s procedure) presented with appropriate ICD shocks due to monomorphic ventricular tachycardia, refractory to antiarrhythmic medications.

Methods and Results

The patient underwent an electrophysiological study and catheter ablation for the VT. Substrate and pace mapping techniques, with the help of an electroanatomical mapping system, was used to localize and ablate the tachycardia successfully.

Conclusions

In patients with D-TGA and Mustard''s repair, scar tissue resulting from VSD repair can act as a substrate for recurrent VT. Catheter ablation of VT is useful in management of VT that occurs despite antiarrhythmic therapy and/or when it is unstable.     

Variable place-cell coupling to a continuously viewed stimulus: evidence that the hippocampus acts as a perceptual system.

A key feature of perception is that the interpretation of a single, continuously available stimulus can change from time to time. This aspect of perception is well illustrated by the use of ambiguous figures that can be seen in two different ways. When people view such a stimulus they almost universally describe what they are seeing as jumping between two states. If it is agreed that this perceptual phenomenon is causally linked to the activity of nerve cells, the state jumps would have to occur in conjunction with changes in neural activity somewhere in the nervous system. Our experiments suggest that hippocampal place cells are part of a perceptual system. We conducted variations of a ''cue-card rotation'' experiment on rats in which the angular position of a prominent visual stimulus on the wall of cylinder is changed in the rat''s presence. The three main results are that (i) place-cell firing fields remain stationary if the cue is rotated by 180 degrees, so the relation between the cue and the field is altered; (ii) firing fields rotate by 45 degrees when the cue is rotated by 45 degrees, so the relation between the field and the card is maintained; and (iii) if the cue is first rotated by 180 degrees and then rotated in a series of 45 degrees steps, the field winds up at a different angular position relative to the card when the card is back in its original position. Thus, place cells can fire in two different ways in response to a continuously viewed stimulus. We conclude that place cells reveal that the hippocampal mapping system also has properties expected of a perceptual system.     

Acceptability of the Cytopipette in General Hospitals

Altogether 2,798 cytopipette smears have been taken by patients entering the general medical and surgical wards of a hospital. Twelve unsuspected positive smears were found, a rate of 4 per 1,000. Biopsy of these patients has shown five pre-malignant lesions, one invasive carcinoma of cervix, and one carcinoma of corpus uteri. Five patients await biopsy.The cytopipette is both acceptable to the patient (62% acceptance) and a feasible laboratory technique and can produce good cytological smears. Only 30% of patients entering the hospital had already had the opportunity to obtain a smear before, and most of them welcomed the opportunity for the test.Though the self-pipette may be criticized for its inaccuracy we feel that any test, if it can detect cervical abnormality at the rate of 4 women per 1,000, is better than no test at all. It should have a place in routine cytological testing of women second only to the use of Ayre''s spatula.     

Neonatal jaundice: the surgical viewpoint.

There is good evidence that neonatal hepatitis, biliary hypoplasia, biliary atresia and choledochal cyst are different stages of one disease process for which the term infantile obstructive cholangiopathy has been suggested. Thanks to the work of Kasai and the operation of hepatic portoenterostomy the surgical outlook has greatly improved, although in North America it still leaves much to be desired. One cannot procrastinate too long in the hope that the patient''s condition will improve spontaneously, because the surgical results are much better when the operation is performed before the patient is 10 weeks old. This article outlines the steps that should be followed in investigating neonatal jaundice, the nonsurgical measures that can be taken in an attempt to reverse or alleviate the underlying condition, and the specific role of the pediatric surgeon in the management of choledochal cyst and biliary atresia.     

Software for minimalistic data management in large camera trap studies

The use of camera traps is now widespread and their importance in wildlife studies is well understood. Camera trap studies can produce millions of photographs and there is a need for a software to help manage photographs efficiently. In this paper, we describe a software system that was built to successfully manage a large behavioral camera trap study that produced more than a million photographs. We describe the software architecture and the design decisions that shaped the evolution of the program over the study's three year period. The software system has the ability to automatically extract metadata from images, and add customized metadata to the images in a standardized format. The software system can be installed as a standalone application on popular operating systems. It is minimalistic, scalable and extendable so that it can be used by small teams or individual researchers for a broad variety of camera trap studies.