When Should I Get My Next COVID Vaccine? Data from the SUrveillance of responses to COVID-19 vaCcines in systEmic immunE mediated inflammatory Diseases (SUCCEED)study

OBJECTIVE

To determine how serologic responses to COVID vaccination/infection in immunemediated inflammatory disease (IMID) are affected by time since last vaccination and other factors.

METHODS

Post-COVID-19 vaccination, data and dried blood spots/sera were collected from adults with rheumatoid arthritis, inflammatory bowel disease, systemic lupus, ankylosing spondylitis/spondylarthritis and psoriasis/psoriatic arthritis. First sample was at enrolment and then 2-4 weeks and 3, 6, and 12 months after latest vaccine dose. Multivariate generalized estimating equation regressions (including medications, demographics, and vaccination history) evaluated serologic response, based on log-transformed anti-RBD IgG titres; we also measured anti-nucleocapsid IgG.

RESULTS

Positive associations for log-transformed anti-RBD titres were seen with female sex, number of doses, and self-reported COVID infections in 2021-2023. Negative associations were seen with prednisone, anti-TNF agents, and rituximab.Over 2021-2023, most (94%) of anti-nucleocapsid positivity was associated with a self-reported infection in the 3 months prior. From March 2021 to Feb 2022, anti-nucleocapsid positivity was present in 5-15% of samples and was highest in the post-Omicron era, with anti-nucleocapsid positivity trending to 30-35% or higher as of March 2023. Anti-nucleocapsid positivity in IMID remained lower than Canada's general population seroprevalence (>50% in 2022 and >75% in 2023).Time since last vaccination was negatively associated with log-transformed anti-RBD titres, particularly after 210 days.

CONCLUSION

Ours is the first pan-Canadian IMID assessment of how vaccine history and other factors affect serologic COVID-19 vaccine responses. These findings may help individuals personalize vaccination decisions, including consideration of additional vaccination when >6 months has elapsed since last COVID vaccination/infection.

Early synapsids neurosensory diversity revealed by CT and synchrotron scanning

Non-mammaliaform synapsids (NMS) represent the closest relatives of today's mammals among the early amniotes. Exploring their brain and nervous system is key to understanding how mammals evolved. Here, using CT and Synchrotron scanning, we document for the first time three extreme cases of neurosensory and behavioral adaptations that probe into the wide range of unexpected NMS paleoneurological diversity. First, we describe adaptations to low-frequency hearing and low-light conditions in the non-mammalian cynodont Cistecynodon parvus, supporting adaptations to an obligatory fossorial lifestyle. Second, we describe the uniquely complex and three-dimensional maxillary canal morphology of the biarmosuchian Pachydectes elsi, which suggests that it may have used its cranial bosses for display or low-energy combat. Finally, we introduce a paleopathology found in the skull of Moschognathus whaitsi. Since the specimen was not fully grown, this condition suggests the possibility that this species might have engaged in playful fighting as juveniles-a behavior that is both social and structured. Additionally, this paper discusses other evidence that could indicate that tapinocephalid dinocephalians were social animals, living and interacting closely with one another. Altogether, these examples evidence the wide range of diversity of neurological structures and complex behavior in NMS.

Whole-body thermal therapy as adjuvant therapy to radiation in a dog with metastasized anal sac adenocarcinoma

An eleven-year-old Galgo Espagnol was diagnosed with metastasized anal sac adenocarcinoma. The patient was enrolled into a clinical trial and underwent three “whole-body thermal therapy” (WBTT) sessions combined with four hypofractionated radiotherapy sessions during a ten-weeks’ time period. The medical device and corresponding treatment protocol were designed by ElmediX (ElmediX NV, Belgium). Air was injected at high speed in a treatment chamber and automatically regulated to reach and maintain a body temperature of 41.5°C for eight hours. Thermometry was ensured by temperature sensors placed in and on the patient. During four radiotherapy sessions, an external beam delivered hypofractionated doses of 6Gy on both the primary tumor and the metastatic lymph nodes. Clinical monitoring and assessment of quality of life confirmed that the WBTT sessions were well tolerated. Although burn wounds at pressure points occurred, prolonged severe adverse effects were not observed. Furthermore, the disease progression was deemed slower than the expected progression based on the literature.

Tolerability of long-term temperature controlled whole-body thermal treatment in advanced cancer-bearing dogs

Aim: In oncology, thermal therapy is the application of external heat to fight cancer cells. The goal of whole-body thermal treatment (WBTT) is to raise the patient's core temperature to 39-42 °C, and represents the only thermal treatment modality that can act on both the primary tumor and distant metastases. However, WBTT carries potential risks for toxicity when applied without accurate thermometry and monitoring.Methods: ElmediX has developed a medical device, HyperTherm, to deliver long-term controlled and accurate WBTT (41.5 °C, up to 8 h). The safety of the device and thermal treatment protocol was initially evaluated in minipigs, and we present the confirmation of tolerability of WBTT in dogs with advanced cancer, in combination with a reduced dose of radiotherapy or chemotherapy.Results: Thermometry in liver, rectum, and tumor confirmed a homogeneous heating of these body parts. Monitoring of clinical parameters showed acceptable and reversible changes in liver, cardiac, muscle and coagulation parameters, as was expected. Combination of WBTT with both radiotherapy and chemotherapy only caused some low-grade adverse events.Conclusion: We conclude that our findings support the safe use of HyperTherm-mediated WBTT for canine patients with advanced malignancies. They also tend to support a genuine therapeutic potential for long-term WBTT which needs to be confirmed on a larger dog patient population. Combined with previously reported safety results in minipigs, these contribute to support the ongoing clinical evaluation of WBTT in advanced human cancer patients.

Palaeoneurological clues to the evolution of defining mammalian soft tissue traits

A rich fossil record chronicles the distant origins of mammals, but the evolution of defining soft tissue characters of extant mammals, such as mammary glands and hairs is difficult to interpret because soft tissue does not readily fossilize. As many soft tissue features are derived from dermic structures, their evolution is linked to that of the nervous syutem, and palaeoneurology offers opportunities to find bony correlates of these soft tissue features. Here, a CT scan study of 29 fossil skulls shows that non-mammaliaform Prozostrodontia display a retracted, fully ossified, and non-ramified infraorbital canal for the infraorbital nerve, unlike more basal therapsids. The presence of a true infraorbital canal in Prozostrodontia suggests that a motile rhinarium and maxillary vibrissae were present. Also the complete ossification of the parietal fontanelle (resulting in the loss of the parietal foramen) and the development of the cerebellum in Probainognathia may be pleiotropically linked to the appearance of mammary glands and having body hair coverage since these traits are all controlled by the same homeogene, Msx2, in mice. These suggest that defining soft tissue characters of mammals were already present in their forerunners some 240 to 246 mya.

Adverse childhood experiences and trauma informed care: the future of health care

Adverse childhood experiences (ACEs) are related to short- and long-term negative physical and mental health consequences among children and adults. Studies of the last three decades on ACEs and traumatic stress have emphasized their impact and the importance of preventing and addressing trauma across all service systems utilizing universal systemic approaches. Current developments on the implementation of trauma informed care (TIC) in a variety of service systems call for the surveillance of trauma, resiliency, functional capacity, and health impact of ACEs. Despite such efforts in adult medical care, early identification of childhood trauma in children still remains a significant public health need. This article reviews childhood adversity and traumatic toxic stress, presents epidemiologic data on the prevalence of ACEs and their physical and mental health impacts, and discusses intervention modalities for prevention.

[Ethics in pediatric emergencies: Care access, communication, and confidentiality]

Children suffer most from today's increasing precariousness. In France, access to care is available for all children through various structures and existing measures. The support for foreign children is overseen by specific legislation often unfamiliar to caregivers. Pediatric emergencies, their location, organization, actors, and patient flow are a particular environment that is not always suitable to communication and may lead to situations of abuse. Communication should not be forgotten because of the urgency of the situation. The place of the child in the dialogue is often forgotten. Considering the triangular relationship, listening to the child and involving the parents in care are the basis for a good therapeutic alliance. Privacy and medical confidentiality in pediatric emergencies are governed by law. However, changes in treatments and medical practices along with the variety of actors involved imply both individual and collective limitations, to the detriment of medical confidentiality.

Clinical outcome, PDGFRβ and KIT expression in feline histiocytic disorders: a multicentre study

Information about histiocytic disease in cats is limited. The aim of this study was to document clinical findings and outcome in feline histiocytic disorders, and characterize the expression of PDGFRβ and KIT in order to identify potential treatment targets. Morphologically diagnosed feline histiocytic tumours were reviewed and characterized by immunohistochemistry (IHC). Five cases of feline progressive histiocytosis (FPH), eight histiocytic sarcomas (HS) and two haemophagocytic histiocytic sarcomas (HaeHS) were confirmed. PDGFRβ was variably positive in most histiocytic cases, while KIT was negative in all. Clinical presentation, treatment and outcome were also evaluated. Partial responses were recorded in measurable disease with tyrosine kinase inhibitors and lomustine, and radiotherapy achieved long-term control in some cases. Survival times were shortest in HaeHS and disseminated disease. PDGFRβ, but not KIT, may represent a therapeutic target in feline histiocytic disorders but more studies are needed to investigate other potential treatment targets.

The inner ear of Diacodexis, the oldest artiodactyl mammal

We provide the first detailed description of the inner ear of the oldest artiodactyl, Diacodexis, based on a three-dimensional reconstruction extracted from computed tomography imagery of a skull of Diacodexis ilicis of earliest Wasatchian age (ca. 55 Ma). This description provides new anatomical data for the earliest artiodactyls, and reveals that the bony labyrinth of Diacodexis differs greatly from that of modern artiodactyls described so far. The bony labyrinth of Diacodexis presents a weakly coiled cochlea (720 °), a secondary common crus, a dorsal extension of the anterior semicircular canal more pronounced than that of the posterior one, and a small angle between the basal turn of the bony cochlear canal and the lateral semicircular canal. This suite of characters also occurs in basal eutherian mammals. Diacodexis strongly resembles small living tragulid ruminants in its overall body shape and hindlimb proportions. Comparison of the bony labyrinth of Diacodexis to that of the tragulid Moschiola meminna (Indian mouse deer) reveals great morphological difference in cochlear shape and semicircular canal disposition. The shape of the cochlea suggests that Diacodexis was a high-frequency hearing specialist, with a high low-frequency hearing limit (543 Hz at 60 dB). By comparison, the estimated low-frequency limit of Moschiola meminna is much lower (186.0 Hz at 60 dB). We also assess the locomotor agility of Diacodexis based on measurements of the semicircular canals. Locomotor agility estimates for Diacodexis range between 3.62 and 3.93, and suggest a degree of agility compatible with a nimble, fast running to jumping animal. These results are congruent with the postcranial functional analysis for this extinct taxon.

TiO2:Ce/CeO2 High Performance Insulators For Thin Film Electroluminescent Devices

The electrical properties of titanium dioxide thin films have been stabilised by cerium doping. These films have a high permittivity between 35 to 45 and withstand 650°C. Multilayer TiO2:Ce/CeO2 insulators have been fabricated. The breakdown voltage is increased by a factor 10 with a modest decrease in the permittivity (30 – 35 instead of 35 – 45).

Electroluminescent devices (ELDs) with a classical ZnS:Mn phosphor have been prepared using TiO2:Ce as the first insulator and a TiO2:Ce/CeO2 multilayer as the second insulator. Compared with a standard ELD based on Y2O3 insulators, devices with the new insulators show a significant decrease of the threshold voltage along with a notable increase of the brightness. An important increase is also achieved in the total device efficiency which is maintained over a large range of brightness and transferred charge. Consequences of rapid thermal annealing and conventional thermal treatments on device performance have also been investigated.

Changes in the regional prevalence of child obesity in 4th, 8th, and 11th grade students in Texas from 2000-2002 to 2004-2005

Although national and state estimates of child obesity are available, data at these levels are insufficient to monitor effects of local obesity prevention initiatives. The purpose of this study was to examine regional changes in the prevalence of obesity due to statewide policies and programs among children in grades 4, 8, and 11 in Texas Health Services Regions (HSRs) between 2000-2002 and 2004-2005, and nine selected counties in 2004-2005. A cross-sectional, probability-based sample of 23,190 Texas students in grades 4, 8, and 11 were weighed and measured to obtain BMI. Obesity was >95th percentile for BMI by age/sex using Centers for Disease Control and Prevention growth charts. Child obesity prevalence significantly decreased between 2000-2002 and 2004-2005 for 4th grade students in the El Paso HSR (-7.0%, P = 0.005). A leveling off in the prevalence of obesity was noted for all other regions for grades 4, 8, and 11. County-level data supported the statistically significant decreases noted in the El Paso region. The reduction of child obesity levels observed in the El Paso area is one of the few examples of effective programs and policies based on a population-wide survey: in this region, a local foundation funded extensive regional implementation of community programs for obesity prevention, including an evidence-based elementary school-based health promotion program, adult nutrition and physical activity programs, and a radio and television advertising campaign. Results emphasize the need for sustained school, community, and policy efforts, and that these efforts can result in decreases in child obesity at the population level.

[Total hip arthroplasty and femoral head osteonecrosis in renal transplant recipients]

PURPOSE OF THE STUDY

Osteonecrosis of the femoral head is reported in a very variable proportion of renal transplant recipients. When these patients require total hip arthroplasty (THA), immunosuppression and poor bone quality increase the risk of aseptic loosening and infection. In the literature, functional outcome has been satisfactory although rates of early and late complications have varied greatly. The purpose of our work was to determine the long-term outcome in a series of renal graft recipients who underwent THA for osteonecrosis of the femoral head.

MATERIAL AND METHODS

Forty-eight THA were implanted for aseptic osteonecrosis of the femoral head (Ficat grade III and IV) in 32 renal transplant recipients between 1974 and 1995 (21 men and 11 women). Mean age was 30 years at transplantation and 39 years at THA surgery. Thirty patients had been on hemodialysis for a mean 1 year prior to transplantation. Joint disease concerned 2 or more joints in 23 of the 32 patients. Fifteen hips had a surgical history: 8 drillings and 3 head arthroplasties. The THA was implanted under general anesthesia via the posterolateral approach. All implants were fixed with a gentamycin cement. A cephalosporin was used for the antibiotic prophylaxis in 20 cases and a cephalosporin/vancomycin combination in 24. Functional outcome was assessed with the Postel-Merle-d'Aubigné (PMA) score. Functional gain was [(PMAreview-PMApreop)/PMApreop]. General or local complications were recorded at last follow-up. The complete or incomplete nature of lucent lines seen on the last follow-up x-rays and their evolution were also recorded. Reasons for second procedures were noted.

RESULTS

Early complications were: phlebitis (n=1), hematoma (n=7), dislocation (n=1), deep infection (n=2). At last follow-up (mean=5 years 7 months), four patients (6 THA) had died and six (7 THA) were lost to follow-up. Preoperatively, function was scored fair or poor in 91% of the patients. At last follow-up function was scored good, very good, or excellent in 75%. Mean functional gain was 38%. A second operation was necessary for seven THA due to aseptic loosening (mean delay 9 years 10 months), for five others for septic loosening (mean delay 6 years 8 months), and finally for two for instability (one early and the other after more than 2 years). In all, 29% of the THA were reoperated. Two deaths were related to late THA infection. Active lucent lines were observed in 11% of the THA (excepting patients reperated for loosening).

DISCUSSION

The functional gain provided by THA in renal transplant recipients with aseptic osteonecrosis of the femoral head is clearly established. Implant survival remains a problem. The rate of early local complications was high in our series, mainly related to hematoma formation and infection. The infections observed were particularly severe requiring early comprehensive management at onset of clinical signs. For patients with suspected deep infection, we propose an aspiration biopsy of the joint to obtain a bacteriological sample.

CONCLUSION

THA enables good functional outcome for renal transplant recipients suffering from osteonecrosis of the femoral head, but at the cost of a high risk of early and long-term complications not always reported in the literature.

Oxaliplatin loaded PLAGA microspheres: design of specific release profiles

Oxaliplatin loaded PLAGA microspheres have been prepared by solvent extraction process. Parameters affecting the release kinetics in vitro have been studied in order to design specific release profiles suitable for direct intra-tumoral injection. By varying the nature and the relative proportions of different polymers we managed to prepare microspheres with good encapsulation efficiency (75-90%) and four different release profiles: zero order kinetics (type II) and the classical sigmoïd release profile with three different sizes of plateau and burst. These results, if correlated with in vivo activity, are promising to enhance effectiveness of local tumor treatment.

The effect of gamma-irradiation on drug release from bioerodible microparticles: a quantitative treatment

The two major objectives of this study were: (i) to monitor the effect of different gamma-irradiation doses (4-33 kGy) on the release kinetics from 5-fluorouracil (5-FU)-loaded poly(D,L-lactide-co-glycolide) (PLGA)-based microparticles, and (ii) to analyze the obtained experimental data with a new mathematical model giving insight into the occurring mass transport phenomena. Drug release was found to depend significantly on the applied gamma-irradiation dose. Interestingly, the obtained release profiles were all biphasic: a rapid initial drug release phase ("burst") was followed by a slower, approximately constant drug release phase. Surprisingly, only the initial rapid drug release was accelerated by gamma-irradiation; the subsequent zero-order phase was almost unaffected. Importantly, the new mathematical model which is based on Fick's second law of diffusion and which considers polymer degradation was applicable to all the investigated systems. In addition, the gamma-irradiation dose could be quantitatively related to the resulting drug release rate. In conclusion, diffusion seems to be the dominating release rate controlling mechanism in all cases, with a significant contribution of the polymer degradation process.

Dynamic cerebral autoregulation is preserved in neurally mediated syncope

To test whether cerebral autoregulation is impaired in patients with neurally mediated syncope (NMS), we evaluated 15 normal subjects and 37 patients with recurrent NMS. Blood pressure (BP), heart rate, and cerebral blood velocity (CBV) (transcranial Doppler) were recorded at rest and during 80 degrees head-up tilt (HUT). Static cerebral autoregulation as assessed from the change in cerebrovascular resistance during HUT was the same in NMS and controls. Properties of dynamic cerebral autoregulation were inferred from transfer gain, coherence, and phase of the relationship between BP and CBV estimated from filtered data segments (0.02-0.8 Hz). During the 3 min preceding syncope, dynamic cerebral autoregulation of subjects with NMS did not differ from that of controls nor did it change over the course of HUT in patients with NMS or in control subjects. Dynamic cerebral autoregulation was also unaffected by the degree of orthostatic intolerance as inferred from latency to onset of syncope. We conclude that cerebral autoregulation in patients with recurrent syncope does not differ from that of normal control subjects.

Impact of a modified apical dissection during radical retropubic prostatectomy on the occurrence of positive surgical margins: a comparative study in 212 patients

OBJECTIVES

To assess the impact of a modified technique of apical dissection during radical retropubic prostatectomy on the occurrence of positive surgical margins (PSMs).

METHODS

Between 1992 and 1998, 212 nonconsecutive patients with localized prostate cancer (57 T1, 155 T2) underwent radical retropubic prostatectomy and were divided into two groups: group 1, 85 patients who underwent surgery before January 1994; and group 2, 127 patients who underwent surgery with the modification of the apical dissection after January 1994. The modified technique consisted of a wide excision of periprostatic soft tissue at the apex, including the bilateral neurovascular bundles. The clinical data (age, prostate-specific antigen, clinical staging) and pathologic findings (pathologic staging, Gleason score, PSM rate) of the two groups were compared.

RESULTS

No significant difference was found between the two groups regarding the median prostate-specific antigen level (10.8 ng/mL and 9.5 ng/mL), Gleason score, and pathologic staging. Overall, the PSM rate was 53% in group 1 and 20.5% in group 2 (P <0.001). The number of PSMs decreased 2.6-fold in group 2. The PSM rate was significantly reduced at the apex with the new technique (group 1, 33.3%; group 2, 7.7%; P = 0.008). The PSM rate expressed with the odds ratio was 4.4-fold lower for patients in group 2 than for those in group 1.

CONCLUSIONS

The modified apical dissection in radical retropubic prostatectomy significantly improves the PSM rate in patients with localized T1-T2 prostate cancer.

Cerebral autoregulation in orthostatic intolerance

Many of the primary symptoms of orthostatic intolerance (fatigue, diminished concentration) as well as some of the premonitory symptoms of neurally mediated syncope (NMS) are thought to be due to cerebral hypoperfusion. Transcranial Doppler measurements of middle cerebral artery blood velocity (CBV) is at present the only technique for assessing rapid changes in cerebral blood flow, and hence for evaluating dynamic cerebral autoregulation. However, controversies exist regarding data interpretation. At syncope, during the collapse of blood pressure (BP), diastolic CBV diminishes, whereas systolic CBV is maintained. Some consider this increase in CBV pulsatility to be indicative of a paradoxical increase in cerebrovascular resistance (CVR) prior to syncope. Others note that mean CBV decreases much less than does mean BP, implying that cerebral autoregulatory mechanisms are intact and functioning at syncope. Similarly, there is no evidence of impaired dynamic cerebral autoregulation, as measured by standard linear transfer-function analysis, in patients with NMS. Some patients with exaggerated postural tachycardia (POTS) have been found to have an excessive decrease in CBV during head-up tilt. Controversy exists as to whether this decrease results from an excessive sympathetic outflow to the cerebral vasculature or from hyperventilation. However, many other equally symptomatic patients with a similar hemodynamic profile of exaggerated tachycardia during head-up tilt have normal CBV changes during this maneuver and have normal dynamic cerebral autoregulation as determined by transfer-function analysis. Whether these discrepancies reflect different pathologies in patients with POTS is currently unknown.

DNA but not topoisomerases is a target for a cytotoxic benzo[5,6]cyclohepta[b]indol-6-one derivative

The interaction of a newly designed benzocycloheptaindol-6-one derivative with DNA has been investigated by complementary spectroscopic techniques including absorption, circular and linear dichroism. Footprinting measurements were performed to delineate the sequence-selectivity of the drug-DNA interaction and a plasmid relaxation assay was used to study the effects of the drug on human DNA topoisomerases I and II. The results clearly indicated that the test compound behaves as a typical DNA intercalating agent but does not stimulate DNA cleavage by topoisomerases. At the cellular level, the cytometry measurements showed that the drug provoked a marked accumulation of HL60 human leukemia cells in the G2/M phase of the cell cycle. DNA is thus identified as a valid target for this new series of drugs particularly toxic to human (HL60) and murine (P388) leukemia cells.

Neuroprotection of nerve growth factor-loaded microspheres on the D2 dopaminergic receptor positive-striatal neurones in quinolinic acid-lesioned rats: a quantitative autoradiographic assessment with iodobenzamide

Huntington's disease (HD) results from the degeneration of striatal neurones, mainly gamma-aminobutyric acid (GABA)ergic projection neurones and lately cholinergic interneurones. The use of trophic factors as agents able to prevent such neural degeneration is a promising strategy. The aim of this study was to validate nerve growth factor-loaded (NGF-loaded) poly-D,L-lactide-co-glycolide (PLGA) microspheres for treatment of HD in a rat model with quinolinic acid lesion using autoradiographic study of D2 dopaminergic receptors (D2R). This target is expressed by about half of striatal neurones and its scintigraphic exploration has already been performed for the follow-up of this degenerative process. Ex vivo autoradiography of D2R performed with iodobenzamide, the widely used ligand for single photo emission computerized tomography, revealed slight neuroprotection. Moreover, tolerance of microspheres was demonstrated by in vitro autoradiography with the marker of gliosis, [(3)H]-PK 11195.

Arthroscopic treatment of bilateral humeral head osteonecrosis

A 37-year-old woman with a renal transplant was treated by arthroscopic debridement for bilateral steroid-induced humeral head osteonecrosis. Radiologically, the right shoulder had been categorized as stage III and the left as stage IV according to Arlet and Ficat. Relief of pain and improved range of motion were obtained especially on the right shoulder. Arthroscopy is an efficient procedure for treatment of humeral head osteonecrosis in the renal transplant recipient including radiological stages III with episodes of locking.

Wrist arthroscopy and dislocation of the radiocarpal joint without fracture

The authors report a rare case of dorsal dislocation of the radiocarpal joint without any bony lesion associated. The traumatic cause was a high energy motorbike accident. Fractures of the other limbs were associated. The authors report the clinical, radiological, and arthroscopic features. Wrist arthroscopy showed a complete tear of all the extrinsic ligaments, a radial avulsion of the triangular fibrocartilage complex, and the integrity of the intracarpal ligaments, which guided the treatment. The dislocation was treated by closed reduction and radiocarpal pinning. The authors propose wrist arthroscopy in radiocarpal dislocation for diagnosis of soft tissue and cartilaginous lesions to guide the treatment (close or open).

Evidence supportive of a functional discrimination between photopic oscillatory potentials as revealed with cone and rod mediated retinopathies

We report on a family where four of the eleven children presented with reduced visual acuities, a red-green deficit at the Farnsworth-Munsel FM 100-hue test, normal appearing fundi and unexpected electroretinographic findings. Light- (photopic) and dark- (scotopic) adapted electroretinograms (ERG) and oscillatory potentials (OPs) were obtained following an accepted standard protocol. The b-wave of their photopic ERG was significantly more attenuated than the a-wave due to the specific abolition of OP4, while the amplitudes of OP2 and OP3 were within the normal range, giving to the b-wave a truncated appearance reminiscent of that seen in congenital stationary night blindness (CSNB) with myopia. Interestingly in the latter condition, which is believed to result from an ON-retinal pathway anomaly, it is OP2 and OP3 which are specifically abolished while OP4 is of normal amplitude thus resulting in an OP response pattern which complements that seen with our patients. Also of interest is the fact that, in our patients, the amplitude of the dark-adapted OP2 was, on average, 240% larger than that measured in light-adaptation while, in normal, a non-significant 14% increase is noted; a finding which is in keeping with other studies reporting supernormal scotopic ERGs in some forms of cone dystrophies. Based on the photopic OP response pattern, our patients represent the electrophysiological complement of patients affected with CSNB. Interestingly their symptoms are also complementary, a finding which could support a functional discrimination between the photopic OPs.

Orthostatic intolerance in the chronic fatigue syndrome

This study aims to investigate the prevalence and pathophysiology of orthostatic intolerance (OI) and its potential contribution to symptoms of a group of unselected patients with chronic fatigue syndrome (CFS). Seventy five patients (65 women, 10 men) with CFS were evaluated. During an initial visit, a clinical suspicion as to the likelihood of observing laboratory evidence of OI was assigned. Laboratory investigation consisted of beat-to-beat recordings of heart rate, blood pressure (Finapres), and stroke volume (impedance cardiograph) while supine and during 80 degrees head-up tilt (HUT), during rhythmic deep breathing (6 breaths/min) and during the Valsalva maneuver. The responses of 48 age-matched healthy controls who had no history of OI were used to define the range of normal responses to these three maneuvers. Forty percent of patients with CFS had OI during head-up tilt. Sixteen exhibited neurally-mediated syncope alone, seven tachycardia (> 35 bpm averaged over the whole of the head-up tilt) and six a mixture of tachycardia and syncope. Eight of 48 controls exhibited neurally-mediated syncope. The responses to the Valsalva maneuver and to deep breathing were similar in controls and patients. On average, the duration of disease and patient age were significantly less and the onset of symptoms was more often subacute in patients with OI than in those without OI. We conclude that there exists a clinically identifiable subgroup of patients with CFS and OI that differs from control subjects and from those with CFS without OI for whom treatment specifically aimed at improving orthostatic tolerance may be indicated.

Persistent functional and structural retinal anomalies in newborn rats exposed to hyperoxia

Previous studies have shown that newborn rats exposed postnatally to hyperoxia will develop a permanent impairment of the retinal function as determined with the electroretinogram (ERG). The purpose of our study was to examine whether postnatal hyperoxia equally alters the light- and dark-adapted ERGs and oscillatory potentials (OPs) as well as leads to permanent structural modification of the retina. During the first 14 days of life, cohorts of Sprague-Dawley rats were exposed to a hyperoxic environment, and ERGs were recorded at mean ages of approximately 25 and 55 days. Our results indicate that both light- and dark-adapted ERGs and OPs are already significantly altered within a few days following exposure to hyperoxia. None of the ERG and (or) OP parameters, with the exception of the a-wave, returned to normal values by 55 days of age. In fact some dark-adapted OPs were completely abolished following postnatal O2 exposure. Histological analysis revealed that the retina of rats exposed to hyperoxia failed to develop an outer plexiform layer and had a reduced count of horizontal cells, consistent with the permanent postreceptoral anomalies seen in the ERG responses. Our results suggest that postnatal hyperoxia causes a generalized retinal disorder leading to permanent structural modifications of the retinal cytoarchitecture and lasting anomalies of the rod and cone functions.

Aseptic avascular necrosis of the femoral condyles in renal transplant patients: clinical and radiological aspects on 69 knees

The purpose of this study was to analyze clinical and radiological aspects of aseptic avascular necrosis (AVN) of the femoral condyles in renal transplant patients. Forty-five renal transplant patients were followed between 1971 and 1993, and 69 knees have been studied. The immunosuppressive protocol comprised in all cases corticosteroids, with aziathioprine and since 1983 cyclosporin in 80% of patients. Episodes of rejection were treated with bolus doses of methylprednisolone. In 53.3% of patients, both knees were involved. The necrosis was bicondylar in 60.8% of knees. In the case of an unicondylar lesion, the lateral condyle was involved in 24.7% of knees vs 14.5% for the medial condyle. Symptoms occurred on average 4.9 years after transplantation (range 3 months-10.5 years). This period appeared significantly shorter for patients who had suffered an episode of rejection. In only 24.4% of patients was the knee involvement isolated. Pain was the initial symptom for 83% of patients. Other symptoms included locked knee (20.7%), effusion (49.2%), instability (14.5%), and loss of motion (15.9%). The diagnosis was established by standard radiographs, and in 8 patients by magnetic resonance imaging. Aseptic AVN of the femoral condyles in renal transplant patients is not rare even if it is less frequent than femoral head necrosis. Medication with corticosteroids is the main risk factor.

New healing agent for colonic anastomosis

This study evaluated the healing property, on colonic anastomoses, of a new compound termed RGTA11 (standing for "regenerating agent," a dextran derivative with heparin-like properties). Colonic anastomoses were performed in 183 adult rats after dipping both ends of the colon in solutions containing RGTA11. The anastomoses were made end-to-end on a single plan, 8 sutures. Healing was evaluated mechanically by the bursting pressure in 108 animals and histological analysis in 75. Results indicated that after 48 h RGTA11-treated animals presented a twofold increased resistance to anastomoses breakage (P < 0.01) over nontreated (saline buffer) animals. After 96 h and until day 7 there was no longer a difference between study and control animals. Although this difference in breakage was not readily observed at histological level, results suggest that RGTA11 could be used to aid colonic anastomosis healing. RGTA11 is of potential clinical interest in this regard since complications that are known to occur postoperatively result from early leakage.

Glomus tumor of the fat pad

The authors report an exceptional glomus tumor location in Hoffa's ligament in a 65-year-old man. Based on this observation and a literature review, the authors provide the clinical and radiographic diagnostic appearances of this type of tumor. Surgical removal of the tumor achieved immediate disappearance of knee pain. Histological examination of the tumor has established the definitive diagnosis.

Hemiretinal contribution to the timing of the full-field PVEP as determined with the motor reaction time

With the use of the simple motor reaction time (RT), we examined the contribution of the hemiretinas to the timing of the pattern reversal visual evoked potential (PVEP). RTs were obtained to the reversal of a progressively dimmer check falling either on the central, nasal, temporal, superior or inferior retina. Results were correlated with the peak time of the P1 wave evoked to the reversal of the entire checkerboard stimulus to the same luminance conditions as that used to generate the RT measurements. Our results clearly indicate that the time taken to trigger a manual response depends not only on the luminance of the stimulus, but also on where it falls on the retina. Comparing the above data with the peak time of the PVEP obtained to the reversal of the entire screen indicates that at brighter luminance the peak time of the P1 wave correlates with that measured from the most central retina, while at dimmer intensities it correlates with the mathematical average of all the retinal locations tested.

Cerebrovascular and cardiovascular measurements during neurally mediated syncope induced by head-up tilt

BACKGROUND AND PURPOSE

This study examines changes in systemic hemodynamics and in cerebral blood velocity that occur during neurally mediated syncope (NMS) to determine whether cerebral autoregulation is intact or impaired in patients with recurrent NMS.

METHODS

Beat-to-beat recordings of heart rate, blood pressure (volume clamp photoplethysmography), stroke volume (impedance cardiography), and right middle cerebral artery blood velocity (transcranial Doppler sonography) were performed at rest and during 80 degrees head-up tilt. Twelve patients with NMS and 10 healthy control subjects were studied.

RESULTS

Baseline values and the initial response to head-up tilt of control subjects and patients with NMS were similar. The mean latency to onset of syncope was 11.8 +/- 11.1 minutes. At syncope, heart rate, systolic and diastolic blood pressure, and diastolic cerebral blood velocity decreased significantly, whereas systolic cerebral blood velocity did not change. Calculated cerebrovascular resistance was significantly reduced from 1.85 +/- 0.60 to 1.32 +/- 0.27 mm Hg/cm per second, whereas the pulsatility index increased from 0.92 +/- 0.16 to 1.52 +/- 0.21. We never observed a change in cerebral blood velocity before the rapid decline in blood pressure, nor did we observe any significant change in respiratory pattern.

CONCLUSIONS

The decrease in cerebrovascular resistance during NMS indicates that the integrity of cerebrovascular autoregulation is maintained even when syncope is imminent. The selective loss of diastolic flow during syncope and the increase in pulsatility index are likely caused by collapse of downstream vessels as diastolic blood pressure decreases below the critical closing pressure of cerebral vessels.

Heparin-like polymers derived from dextran enhance colonic anastomosis resistance to leakage

A new tissue repair agent, RGTA11, is described for its ability to enhance colonic anastomosis repair and resistance to leakage. RGTA11 is a dextran derivative containing 110% carboxymethyl groups, 2.6% carboxymethyl benzylamide groups, and 36.6% carboxymethyl benzylamide sulfonate groups. RGTA11 was deemed efficient to protect the heparin-binding growth factors FGF2 against trypsin digestion. By this property RGTA11 mimicked heparin or heparan sulfate. We have also found that RGTA11 protected TGF beta 1 against trypsin digestion while heparin did not. RGTA11 was then tested in an in vivo wound-healing model of colonic anastomosis. Our results indicate that after 48 h, RGTA11- or RGTA11/FGF-2-treated animals presented a resistance of the anastomosis to leakage which was increased twofold (p < 0.05) over untreated controls. After 96 h and until day 7 there was no more difference with control animals. Our results suggest that RGTA11 presents potential clinical interest by preventing earlier leakage of colonic anastomosis.

Heparin-like polymers derived from dextran enhance colonic anastomosis resistance to leakage

A new tissue repair agent, RGTA11, is described for its ability to enhance colonic anastomosis repair and resistance to leakage. RGTA11 is a dextran derivative containing 110% carboxymethyl groups, 2.6% carboxymethyl benzylamide groups, and 36.6% carboxymethyl benzylamide sulfonate groups. RGTA11 was deemed efficient to protect the heparin-binding growth factors FGF2 against trypsin digestion. By this property RGTA11 mimicked heparin or heparan sulfate. We have also found that RGTA11 protected TGF beta 1 against trypsin digestion while heparin did not. RGTA11 was then tested in an in vivo wound-healing model of colonic anastomosis. Our results indicate that after 48 h, RGTA11- or RGTA11/FGF-2-treated animals presented a resistance of the anastomosis to leakage which was increased twofold (p < 0.05) over untreated controls. After 96 h and until day 7 there was no more difference with control animals. Our results suggest that RGTA11 presents potential clinical interest by preventing earlier leakage of colonic anastomosis.

Osteonecrosis of the hip in renal transplant recipients. Changes in functional status and magnetic resonance imaging findings over three years in three hundred five patients

OBJECTIVE

to conduct a retrospective study of the appearance and course of magnetic resonance imaging abnormalities in avascular osteonecrosis of the femoral head in renal transplant recipients and of potential relations between these abnormalities and the functional outcome.

PATIENTS AND METHODS

among 305 renal transplant recipients, patients with pain in the hips or knees underwent radiographs and magnetic resonance imaging studies of the hips and, if appropriate, of the knees. The mean time interval between these studies and transplantation was 8.9 months. The outcome was evaluated based on the Lequesne index and findings from a repeat magnetic resonance imaging study after a mean follow-up of 33 months since transplantation. The criteria developed by Mitchell et al. were used to diagnose osteonecrosis on magnetic resonance images. The size of the necrotic area was estimated using the tracing paper method as < 25%, 25-50%, > 50% of the surface of the femoral head. Eleven patients were treated by elimination of weight-bearing and conservative treatments and 15 underwent core decompression (radiographic stage I or II).

RESULTS

Fourteen patients (4.5%) developed osteonecrosis of the femoral head, which was bilateral in 12 patients and unilateral in two: thus, the total number of hips with osteonecrosis was 26. The first magnetic resonance imaging study disclosed a crescent-shaped area of low signal intensity in 25 cases, most of which were mild in severity as assessed on radiographs (Arlet and Ficat stage I or II). Extensive necrosis was found in most cases at the first evaluation (> 25% in 15 cases and > 50% in eight). The surface of the necrotic area (as assessed irrespective of the treatment used) remained unchanged in 20 cases and decreased in six. In half the cases the hyperintense signal from the sequestrum converted to a hypointense signal after a mean follow-up of 39 years. A poor functional outcome (Lequesne's index > 7 or total hip arthroplasty) was seen in 61.5% of cases, irrespective of the treatment used.

CONCLUSION

Avascular osteonecrosis of the femoral head precipitated by corticosteroid therapy in renal transplant recipients occurred in 4.5% of patients immediately involved a large segment of the epiphysis, and usually remained stable over time, although a decrease in the size of the lesion was seen in a few cases. Overall, the functional prognosis was poor, with a Lequesne's index greater than 7 or total hip arthroplasty in two thirds of cases after three years' follow-up. The incidence of avascular osteonecrosis of the hip in renal transplant recipients has decreased since 1980, when cyclosporin was introduced and doses of corticosteroids used to treat rejection episodes were diminished.