Functional evaluation of normal and pathologic knees during gait

The functional performance of the knee joints of 29 normal volunteers, 65 patients with degenerative joint disease and 30 patients with rheumatoid arthritis was studied according to clinical (historical, physical and roentgenographic) and biomechanical gait parameters. Temporal and distance gait factors (velocity, cadence and stride length) were significantly reduced in patients with diseased knees. Sagittal plane knee motion was markedly reduced, as was stance phase flexion, indicating poor tolerance of loading the flexed knee in the patient groups. There was no correlation between passive motion of the diseased knee and the amount of motion used during gait. Patients with rheumatoid arthritis generally showed more compromise of knee joint function than did patients with degenerative joint disease. Statistically, significant correlations between various clinical and biomechanical gait parameters suggest that the techniques used are an objective measurement of knee joint function and may be employed as a means of evaluating various treatment modalities for the diseased knee.     

Ankle weight effect on gait: orthotic implications

Oxygen consumption during ambulation was measured in 10 normal subjects wearing ankle weights of 0.91 kg, 1.82 kg, and 2.73 kg, either on the right ankle or bilaterally. Subjects walked at self-selected speeds and oxygen consumption was measured over 1-minute intervals during steady-state walking. Oxygen consumption per unit distance and oxygen consumption rate demonstrated significant positive linear correlations with added weight (P = .001, P = 0.007, respectively). Velocity demonstrated a significant decrease when correlated with added weight (P = 0.03). Multiple regression analysis was used to relate these measures of oxygen consumption rates to velocity, age, and added weight, yielding predictive relationships. Based on these results, the weight of orthoses should be minimized in order to maximize walking velocity and minimize oxygen consumption per unit distance. The advantage of a light-weight, molded plastic ankle-foot orthosis (AFO) over heavier AFO designs is demonstrated by this study.     

Fast tracking in cardiac surgery: implications for practice

Even though economic incentives might have been the impetus for its revival, fast tracking offers numerous other benefits, not the least of which is improved patient care. However, its benefits can be realized only through specific perioperative management, including preoperative assessment, identification and selection of appropriate candidates, optimal intra- and postoperative management and interdisciplinary discharge planning. Through interdisciplinary collaboration, the maximum benefits of fast tracking can be reaped by both the patient and the healthcare team.     

Aryepiglottic fold: normal topography and clinical implications

The aryepiglottic folds extend between the arytenoid cartilage and the lateral margin of the epiglottis on each side and constitute the lateral borders of the laryngeal inlet. They are involved in physiologic closure mechanisms of the larynx and in pathologic conditions such as inspiratory stridor. Information on the normal topography of the aryepiglottic folds is poor and controversial. Therefore, this region was reinvestigated in serial whole-organ sections of 25 plastinated normal adult human larynges. Dorsally, the right and the left aryepiglottic folds are separated by the interarytenoid notch and comprise the corniculate and cuneiform cartilages, as well as numerous groups of mucous glands. Ventrally, the aryepiglottic folds are adjacent to the peri-epiglottic adipose tissue. Both regions are clearly separated by several layers of transversely oriented collagenous fiber layers. The muscular constituent of the aryepiglottic folds is only poorly developed, and no muscle fibers insert at the epiglottis. A coherent quadrangular membrane representing a ligamentous "skeleton" of the aryepiglottic folds is absent. A conspicuous collagenous fiber layer is found only to strengthen the free dorsal margin of the fold. Both muscular and ligamentous components may render the aryepiglottic folds sufficiently tense as to resist inspiratory inward suction in normal cases. However, pliability must be preserved to guarantee adequate folding in approximation of the aryepiglottic folds during deglutition. Thereby, the posterior part of the laryngeal inlet is closed, whereas the anterior part is probably closed by independent inward bulging of the peri-epiglottic adipose tissue.     

Pectoralis major rupture during gait training: case report

The macrophage derived cytokines interleukin-beta (IL-1beta), and tumor necrosis factor alpha (TNFalpha), and the T-cell derived cytokine interferon gamma (IFNgamma) have been implicated to play an important role in early attack on islet cells during human islet transplantation (ITx). Therefore, the aim of this study was to investigate the influence of the current immunosuppressive induction therapy in clinical islet transplantation on mRNA expression of these cytokines in blood cells, compared to lipopolysaccharide (LPS) induced cytokine release in vitro and to plasma levels. The cytokine release correlated to lymphocyte counts and significantly decreased after ATG, and partially recovered 2 weeks after ITx. Unexpectedly, there was no correlation between mRNA expression for IL-1beta in total blood and the number of lymphocytes and monocytes remaining after anti thymocyte globulin (ATG)-therapy. Even when the blood was nearly totally depleted from mononuclear cells, high amounts of IL-1beta mRNA could be detected. However, IL-1beta secretion could not be stimulated in vitro. Our results show that application of ATG during ITx might contribute to graft survival during the early posttransplant period by suppression of the synthesis of monocyte derived cytokines IL-1beta and TNFalpha.     

Adolescent stress and coping: implications for psychopathology during adolescence

Stressful experiences and efforts to cope with stress are central to understanding psychological distress and psychopathology during adolescence. Depressive phenomena during adolescence offer a particularly interesting opportunity for understanding the role of stress and coping processes in adolescent psychopathology. Research concerned with stress and coping during adolescence is reviewed, using depression as a key example of a consequence of stress and coping processes. Based on this research, it is hypothesized that exposure to and appraisals of interpersonal stress combine with aspects of biological development and the use of maladaptive coping strategies to account for the emergence of significant gender differences in depression and other forms of psychopathology during adolescence. Directions for future research in this area are highlighted.     

The cutaneous innervation of the female breast and nipple-areola complex: implications for surgery

The treatment of myelodysplastic syndromes (MDSs) continues to be challenging and difficult to standardize. This article describes a decision tree for the treatment of MDSs based on age, presence or absence of a potential HLA-identical donor, and prognostic factors including bone marrow blast proportion, severity of cytopenias, and karyotype.     

Cutaneous reflexes during human gait: electromyographic and kinematic responses to electrical stimulation

The functions of ipsilateral cutaneous reflexes were studied with short trains of stimuli presented pseudorandomly to the superficial peroneal (SP) and tibial nerves during human gait. Electromyograms (EMGs) of tibialis anterior (TA), soleus, lateral and medial gastrocnemius, vastus lateralis (VL), and biceps femoris (BF) muscle were recorded, together with ankle and knee joint angles. Net reflex EMG responses were quantified in each of the 16 parts of the step cycle according to a recently developed technique. After SP nerve stimulation, TA muscle showed a significant suppression during swing phase that was highly correlated to ankle plantarflexion. BF and VL muscles were both excited throughout swing and significantly correlated to knee flexion during early swing. Tibial nerve stimulation caused dorsiflexion during late stance, but plantarflexion during late swing. We argue that SP nerve reflexes are indicative of a stumbling corrective response to nonnoxious electrical stimulation in humans. The correlated kinematic responses after tibial nerve stimulation may allow smooth movement of the swing leg so as to prevent tripping during swing and to assist placing and weight acceptance at the beginning of stance.     

Distribution of normal and abnormal fluid collections in the glenohumeral joint: implications for MR arthrography

OBJECTIVE: This study determined levels of cathepsin D activity in tissue components of normal human ovary to establish a basis for comparison with human ovarian adenocarcinomas. METHODS: Cathepsin D activity per mg tissue, per microgram protein, and per microgram DNA was determined in human ovarian tissues (cortex, follicle, corpus luteum, corpus albicans) from patients of various ages and during the menstrual cycle. Levels of cathepsin D activity were also determined in ovarian adenocarcinomas and other pathologic tissues. RESULTS: Cathepsin D levels (per mg tissue) were significantly greater (P < .001) in ovarian follicle and corpus luteum compared with cortex. Although there was not a clear correlation between enzyme activity in the cortex and day of the menstrual cycle or patient age, levels of enzyme activity appeared to decrease with each parameter. Cathepsin D levels per mg tissue in ovarian adenocarcinoma were 40% higher than in postmenopausal ovarian cortex, but the difference was not statistically significant. CONCLUSION: The diversity of cathepsin D levels in normal ovarian tissue compartments indicates that specific tissues must be used in comparisons with ovarian tumors.     

Vascular and visceral injuries associated with lumbar disc surgery: medicolegal implications

Symptomatic perforation of the anterior annulus fibrosus/anterior longitudinal ligament during surgery for herniated lumbar disc disease is one of the more solemn and sobering complications experienced by neurosurgeons or orthopedic surgeons. This complication frequently results in the death of the patient. Its occurrence is probably more common than the medical community would expect. The authors report 21 cases since 1985 in which an injury to an intra-abdominal vessel or viscera occurred. In all cases litigation resulted and a settlement or verdict was rendered. A review of the literature is presented and the medicolegal implications of symptomatic ventral perforations of the annulus fibrosus/anterior longitudinal ligament are discussed.     

Oxygen regulates human cytotrophoblast differentiation and invasion: implications for endovascular invasion in normal pregnancy and in pre-eclampsia

This review article focuses on the unique process by which the human placenta normally forms and how changes in this process can lead to serious pregnancy complications such as pre-eclampsia. One way to compare normal and pathologic pregnancies is to examine biopsy specimens of the placenta and placental bed for disease-associated morphological changes in cellular architecture. Our recent work has verified the decades-old observation that pre-eclampsia is associated with abnormally shallow placentation. We also discuss how these morphological observations prompted us to use a combination of in vitro modeling and in situ immunolocalization techniques to gain insights into the molecular bases of normal placentation and how these mechanisms go awry in pre-eclampsia.     

Internal shear properties of fresh porcine aortic valve cusps: implications for normal valve function

BACKGROUND AND AIMS OF THE STUDY: Several types of stress act on aortic heart valve tissue during the cardiac cycle. When closed the valve is subjected to primarily tensile stress due to the diastolic pressure, and upon opening bending stress occurs near the attachment with the aortic root and throughout the body of the cusps. Smooth bending requires internal tissue shearing. To measure the internal shear properties of the tissue a testing device was created which combined a high-precision linear actuator with a sensitive load cell. MATERIALS AND METHODS: Circular punch biopsy specimens from fresh porcine aortic valve cusps (n = 32) were examined. The shear stress versus shear strain characteristics were measured both in the circumferential (n = 17) and the radial (n = 13) direction, and the stress relaxation characteristics were also examined circumferentially (n = 15) and radially (n = 15). In addition seven specimens were tested repeatedly in both radial and circumferential directions for tissue isotropy. RESULTS: The results from the shear stress versus strain tests showed the tissue to behave non-linearly over the strain range between -0.9 and 0.9. The average moduli at the near zero strains were less than 300 Pa and increased to over 20 kPa at the extreme strains. The circumferential direction yielded slightly higher average moduli than the radial direction but this difference was not significant. The stress relaxation results indicated that valve tissue relaxation occurs in two distinct phases, an initial low slope region and a second high slope region with respective values of -7.5 log(s)-1 and -15 log(s)-1 and with no significant difference between test directions. CONCLUSIONS: Our results define and describe the pattern of internal shear properties of the aortic valve that are particularly important during the transition between the open and closed positions. This behavior pattern has particular application in the creation of accurate mathematical models of the valve tissue and may be important in understanding the mechanism of tissue failure in bioprosthetic valves.     

Malnutrition and mortality during recent famines in Ethiopia: implications for food aid and rehabilitation

The 1972-73 and 1984-85 famines varied significantly among different populations within famine areas at the regional, community and household levels. Political and social factors were crucial in this pattern. Evidence from both pastoral and farming areas indicates that the development of community-based resources may be less disruptive socially and economically and result in less morbidity and mortality than dependence on relief shelters. Areas needing further study are identified.     

Malignant lymphoma: implications during the reproductive years and pregnancy

The malignant lymphomas are reviewed, and involvement of urogenital-ridge derivatives, including the reproductive organs, is summarized. Implications of therapy for pelvic lymphoma are discussed. It is shown by a retrospective analysis that Hodgkin's disease has little effect on fertility, the course of gestation, delivery or fetal wastage and that maternal death is not increased. No adverse effect of pregnancy on the symptoms or longevity of women with Hodgkin's disease can be demonstrated. Women diagnosed in pregnancy as having lymphoma should undergo therapeutic abortion so that proper staging and therapy may be given. Pregnancies over 32 to 34 weeks should be induced. Women previously treated for lymphoma may become infertile as a result of therapy. Those not infertile after therapy should avoid pregnancies since there is a potential risk of malformations and malignancies in the offspring.     

Bilateral first rib fractures associated with driver's air bag inflation: case report and implications for surgery

A case of bilateral fractures of the first rib occurring in an otherwise fit road traffic accident victim is described. The only other injuries sustained were of the peripheral limbs. The driver's air bag was inflated during the crash, leading to speculation as to whether this may have contributed to the mechanism of injury. The patient was well oxygenated and cardiovascularly stable with no evidence of neurovascular damage to the thoracic aorta or its branches. Aortic arch aortography was not performed before internal fixation of the peripheral fractures was undertaken under general anaesthesia. A review of the indications for angiography in such patients follows. The policy that patients with fractures of the upper first ribs do not require angiography unless there is other evidence of neurovascular damage is supported.     

Anatomical variation in the rudimentary horns of a unicornuate uterus: implications for laparoscopic surgery

The effect of the beta3-adrenoceptor agonist [ N-[(2S)-7-ethoxycarbonyl-methoxyl-1,2,3,4-tetrahydronaphth-2-yl] (2R)-2-(3-chloro-phenyl)2-hydroxyethanamine hydrochloride] (SR58611A) on gastric acid secretion was investigated in conscious cats with a gastric fistula. Intravenous infusion of SR58611A (0.3-3 micromol/kg/h) caused a dose-dependent inhibition of the acid secretion stimulated by 2-deoxy-D-glucose (2DG), with a maximum reduction by 45%. The secretory effect of the histamine H2-receptor agonist dimaprit only tended to be reduced by SR58611A (3 micromol/kg/h). The inhibitory effect of SR5861 IA was not modified by the non selective beta1- and beta2-adrenoceptor antagonist propranolol (1.5 micromol/kg i.v.), but it was prevented by bupranolol (10 micromol/kg i.v.), a drug endowed with beta3-antagonistic properties. Both antagonists blocked the inhibitory effect of the beta2-adrenoceptor agonist clenbuterol (0.1 micromol/kg/h) on 2DG-induced acid secretion. These findings suggest that compound SR58611A inhibits gastric acid secretion in the conscious cat through activation of beta3-adrenoceptors insensitive to propranolol.     

Effects of routine hyperventilation on PCO2 and PO2 in normal subjects: implications for EEG interpretations

There are few data in the EEG literature describing the time course of hyperventilation-(HV) induced changes in blood gases, despite this being a routine activating procedure. We studied changes in blood gases and EEG in nine normal adult subjects before, during, and after HV. The mean PCO2 fell 18 mm Hg from the baseline during HV and recovered in 7 min. The mean PO2 rose 7 mmHg during HV and fell to 25 mm Hg below baseline 5 min after HV. The PCO2 recovery period is longer than is usually assumed in clinical EEG. The PO2 fall to a nadir at 5 min after the end of HV suggests that close attention should be paid to this period, as is confirmed by the re-buildup seen in moyamoya disease. Despite uniform changes in blood gases, the EEG median power frequency change showed marked variability; on average, it dropped by 1 Hz during HV and returned to baseline within 2 min of resumption of normal respiration. The EEG root-mean-square power showed a 200% increase during HV and also had returned to normal within 2 min.     

Caring for the carers during transplant surgery

Staff working in theatre departments play a vital role in organ retrieval. However, many find involvement with organ donation uncomfortable and sometimes distressing. They may also have misunderstandings about what takes place before and after the retrieval operation. This article will examine the issue of organ donation from the perspective of the operating theatre staff and offer insight into the process of organ donation prior to and following the retrieval surgery.