The Effect of Single Accreditation on Medical Student Match Rates in Surgical Specialties.

Introduction The year 2020 marked the first year in which a match under single accreditation took place. Both osteopathic (DO) and allopathic (MD) students would participate in the first match cycle without a dedicated DO match system. Our primary objective was to investigate how single accreditation has impacted the DO applicants attempting to match into surgical specialties. Our secondary objective was to investigate the impact of single accreditation at the program director (PD) level and whether or not this process would see a change in DO PD distribution in previously American Osteopathic Association (AOA)-approved programs. Method Information on number of applicants and post-match positions was gathered from AOA and National Residency Match Program (NRMP) websites. Credentials of PDs were obtained from the Accreditation Council on Graduate Medical Education website. Based on the available data, the following surgical specialties were compared for the years 2020, 2018, and 2016: General Surgery, Neurological Surgery (NSGY), Orthopedic Surgery, Otolaryngology/ENT (ENT), Plastic Surgery, and Thoracic Surgery. Data from 2016 were not included in the results as the AOA match results analysis was insufficient and unable to be directly compared to the NRMP data. Results of matched DO and MD applicants were compared using bivariate analysis. A p-value of <0.05 was considered significant. Results From the year 2018 to 2020, the DO applicants saw a decrease of 3% in the total number of matched postgraduate year 1 spots in surgical specialties. NRMP results from 2020 saw that 51.7% of DO applicants matched and 67.7% (p < 0.001) of MD applicants matched for the specialties examined. Percent of matched:applied for DO applicants was lower than MD applicants in the fields of NSGY (p < 0.001), ENT (p < 0.001), Plastic Surgery (p < 0.001), General Surgery (p < 0.001), and Thoracic Surgery (p = 0.011). After evaluating 60 former AOA General Surgery programs, 56% were found to have MD as PD. Another 26 former AOA surgical programs were investigated, and 58% were found to have MD PD.  Conclusion Single accreditation has impacted the match process now that a large number of both MD and DO applicants are using the NRMP match system for postgraduate placement. Based on the available data, our results indicate that in the examined surgical specialties, there is a statistically significant difference in the number of MD and DO residents.

Human T lymphocytes reactive with whole myelin recognize predominantly myelin basic protein.

Human T-cell lines and clones reactive with whole human myelin were isolated from three normal subjects by in vitro sensitization techniques. The CD4+ T-cell lines were maintained in long-term culture by periodic antigen restimulation with myelin and use of interleukin-2. Although myelin basic protein (MBP) represents only about 10% of the dry weight of myelin and the myelin-reactive T-cell populations were never exposed to purified MBP, each of the three cell lines responded to in vitro stimulation with both MBP and whole myelin. Seventeen of 18 T-cell clones derived from the myelin-reactive cell lines also responded to MBP. One myelin-reactive T-cell clone did not recognize MBP or the major myelin lipids but responded to delipidated myelin proteins suggesting that this clone recognized another myelin protein antigen. These results indicate that MBP is the predominant antigen in whole myelin recognized by human T cells under the culture conditions described. However, there is at least one additional protein antigen in myelin that is also immunogenic.

Immune responses to myelin antigens in multiple sclerosis.

Multiple sclerosis is considered to be a putative immunopathologic disease and there has been considerable effort over the years to prove an autoimmune etiology for it. To date, the evidence is all indirect and there is no proof of either antibody and/or cell-mediated hypersensitivity to any single identifiable CNS constituent whether a constituent of normal CNS or specific to the CNS of MS patients.

A new striatal model and its relationship to basal ganglia diseases.

A new model of the striatum has recently been proposed. This model suggests that the somatotopic regions of the striatum correspond to state spaces governing various aspects of organism behavior (e.g., reaching, egomotion, task planning). The model is reviewed, and shown to be applicable to sequencing tasks. The model is also discussed in the context of some basal ganglia diseases.

Products of activated lymphocytes stimulate Schwann cell mitosis in vitro.

Culture of Schwann cells and endoneurial fibroblasts from newborn rat sciatic nerves in the presence of supernatants obtained from concanavalin A (Con-A)-stimulated rat mononuclear cells resulted in proliferation of both cell types. Con-A did not induce Schwann cell or fibroblast proliferation. Supernatant from a Gibbon T-cell lymphoma and chromatographically purified rat interleukin-2 (IL-2) induced fibroblast but not Schwann cell proliferation, and cloned human IL-2 did not induce proliferation of either cell type. Proliferation of Schwann cells and endoneurial fibroblasts induced by activated mononuclear inflammatory cells may be important in inflammatory demyelinative neuropathies.

FDTD analysis of close-coupled 418 MHz radiating devices for human biotelemetry.

This paper describes the finite-difference time-domain (FDTD) analysis of antenna-body interaction effects occurring when chest-mounted 418 MHz radio transmitters are used for medical telemetry applications. Whole-body software models (homogeneous, layered and tissue-segmented) were developed for an adult male subject. Using an electrically small (300 mm2) planar loop antenna, calculated radiation efficiencies ranged between 33.5% and 39.2% for a whole-body model, and between 60.7% and 66.1% for a torso; radiation patterns were found to be largely independent of model composition. The computed radiation efficiency for a 21.5 kg phantom representing a six-year-old female was within 1.1 dB of measured results (actual body mass 28 kg) and well-correlated azimuthal radiation patterns were noted.

Radiowave propagation from a tissue-implanted source at 418 MHz and 916.5 MHz.

Tissue-implanted ultra-high frequency (UHF) radio devices are being employed in both humans and animals for telemetry and telecommand applications. This paper describes the experimental measurement and electromagnetic modeling of propagation from 418-MHz and 916.5-MHz sources placed in the human vagina. Whole-body homogeneous and semi-segmented software models were constructed using data from the Visible Human Project. Bodyworn radiation efficiencies for a vaginally placed 418-MHz source were calculated using finite-difference time-domain and ranged between 1.6% and 3.4% (corresponding to net body losses of between 14.7 and 18.0 dB). Greater losses were encountered at 916.5 MHz, with efficiencies between 0.36% and 0.46% (net body loss ranging between 23.4 and 24.4 dB). Practical measurements were in good agreement with simulations, to within 2 dB at 418 MHz and 3 dB at 916.5 MHz. The degree of tissue-segmentation for whole-body models was found to have a minimal effect on calculated azimuthal radiation patterns and bodyworn radiation efficiency, provided the region surrounding the implanted source was sufficiently detailed.

The design and performance of a 2.5-GHz telecommand link for wireless biomedical monitoring.

This paper details the implementation and operational performance of a minimum-power 2.45-GHz pulse receiver and a companion on-off keyed transmitter for use in a semi-active, duplex RF biomedical transponder. A 50-ohm microstrip stub-matched zero-bias diode detector forms the heart of a body-worn receiver that has a (CMOS baseband amplifier consuming 20 microA from +3 V and achieves a tangential sensitivity of -53 dBm. The base transmitter generates 0.5 W of peak RF output power into 50 ohms. Both linear and right-hand circularly polarized Tx-Rx antenna sets were employed in system reliability trials carried out in a hospital Coronary Care Unit. For transmitting antenna heights between 0.3 and 2.2 m above floor level, transponder interrogations were 95% reliable within the 67-m2 area of the ward, falling to an average of 46% in the surrounding rooms and corridors. Overall, the circular antenna set gave the higher reliability and lower propagation power decay index.

Fading characteristics of a 2.3 GHz radio telemetry channel in a hospital building.

This paper reports on radio path attenuation measurements made in a hospital complex at a spot frequency of 2.340 GHz. Power loss figures for fixed path propagation in a variety of building types have been determined for proposed telemetry use in operational ward situations. Throughout the hospital, the radio paths assessed all exhibited a loss in excess of that calculated for free-space communications. Modern buildings had external wall losses of 10-25 dB, with dividing walls in wards contributing an additional 5 dB. Received signal strength levels indicated a Rayleigh distribution for obstructed paths. Temporal testing was used to find the rate and depth of signal fades caused by the movement of personnel and equipment during normal ward usage; signal level reductions of greater than 35 dB were common during busy periods.

On the design and assessment of a 2.45 GHz radio telecommand system for remote patient monitoring.

This paper discusses the design and operational assessment of a minimum-power, 2.45 GHz portable pulse receiver and associated base transmitter comprising the interrogation link in a duplex, cross-band RF transponder designed for short-range, remote patient monitoring. A tangential receiver sensitivity of - 53 dBm was achieved using a 50 ohms microstrip stub-matched zero-bias diode detector and a CMOS baseband amplifier consuming 20 microA from + 3 V. The base transmitter generated an on-off keyed peak output of 0.5 W into 50 ohms. Both linear and right-hand circularly-polarised antennas were employed in system evaluations carried out within an operational Coronary Care Unit ward. For transmitting antenna heights of between 0.3 and 2.2 m above floor level. transponder interrogations were 95% reliable within the 82 m2 area of the ward, falling to an average of 46% in the surrounding rooms and corridors. Separating the polarisation modes, using the circular antenna set gave the higher overall reliability.

Enterogastric reflux mimicking gallbladder disease: detection, quantitation and potential significance.

OBJECTIVE: Visualization of enterogastric reflux (EGR) may be present during hepatobiliary imaging. Reflux of bile may damage the gastric mucosa, altering its function, and cause such symptoms as epigastric pain, heartburn, nausea, intermittent vomiting and abdominal fullness. These symptoms also are associated with gallbladder disease. The aim of this study was to quantitate the EGR index (EGRI) and to determine if a difference exists in normal and abnormal responses using standard cholecystokinin (CCK)-augmented hepatobiliary imaging. METHODS: This study used 129 patients. LAO dynamic data on a 128 x 128 matrix at a rate of 1 frame/min were obtained. After the gallbladder ejection fraction (GBEF) was determined, the EGRI (%) was calculated by relating the counts in the gastric ROI to the counts in the hepatobiliary ROI at a specified time. The results were compared with the patient's final clinical diagnosis. RESULTS: Normal responders (GBEF > or = 35%) had a higher EGRI than abnormal responders with a P = 0.001 EGR observed in 75 patients (58.1%). Significant reflux (EGRI > or = 14.2% at 15 min) was observed in 29 additional patients (22.5%). Patients with EGRI > or = 24.5% showed a strong association with the pathophysiologic syndrome of gastritis, alkaline reflux, gastric ulcer and gastro esophageal reflux disease. There was no EGR observed in the remaining 25 patients (19.4%). CONCLUSION: This simple addition to the CCK-augmented hepatobiliary imaging may both detect and quantitate abnormal EGR as the cause of the patient's symptoms in the presence of a normal GBEF result, and/or those patients with risk factors for gastritis.

Daclizumab phase II trial in relapsing and remitting multiple sclerosis: MRI and clinical results.

OBJECTIVE: Daclizumab is an interleukin 2 receptor alpha chain specific humanized monoclonal antibody that has shown promising therapeutic effects in multiple sclerosis (MS). Daclizumab treatment in patients with relapsing and remitting MS was administered to determine effects on MRI and clinical outcomes. METHODS: Patients with MS on interferon (IFN) therapy but with continuing relapses and contrast enhancing lesions (CEL) were selected. Patients were evaluated with monthly MRI scans and clinical rating scales starting 3 months prior to treatment and then at 0.5 to 27.5 months during treatment. Daclizumab (1 mg/kg IV) was administered twice in the first month (initiated and administered again in 2 weeks), followed by treatments every 4 weeks. IFN was continued until 5.5 months after daclizumab was initiated. Patients were then placed on daclizumab monotherapy. Patients with recurrent CEL were restarted on IFN with daclizumab therapy at (1.5 mg/kg IV) every 28 days. RESULTS: Nine patients qualified for inclusion and completed the trial. Efficacy measured by both total CEL and new CEL (p < 0.001), relapses, timed ambulation, Expanded Disability Status Scale, and Neurologic Rating Scale (p < 0.05 to p < 0.01) was observed. CONCLUSION: Daclizumab was effective in reducing contrast enhancing lesions and improving clinical scores in patients with relapsing and remitting multiple sclerosis with active disease not controlled by interferon therapy. These results provide evidence for long-term efficacy and support further clinical development of daclizumab.

A model for the functioning of the striatum.

A model is presented for the operation of the striatum. The model posits that the basal ganglia are responsible for driving smooth transitions of state for an organism. We propose that this is accomplished through the computation of a potential function within the striatum on which a gradient descent is performed toward the goal state. The model suggests that various somatotopic regions of the striatum correspond to state spaces, each of which pertains to a different aspect of the organism. This paper discusses this model only in the context of motor control, i.e., egomotion and limb movement. The model appears to account for a variety of experimental results, and for some unusual properties of the striatum.

Isolation of CD45RO+, memory T cells recognizing proteolipid protein from neurologically normal subjects.

Previous studies provide evidence for in vivo activation of MBP-reactive T cells in subjects with multiple sclerosis. In general, in vivo activation occurs less frequently in healthy control subjects. In the current study we examined the T cell response to proteolipid protein in PBMC isolated from 9 control subjects. We used CD45 isotypes as markers for memory and naïve T cells to assess in vivo activation of CD4+ T cells reactive with PLP. In contrast to the results obtained using MBP, we found that approximately 50% of PLP-reactive T cells were derived from the CD45RO+ memory subpopulation of T cells isolated from these control subjects. These results indicate that some myelin-reactive T cells have undergone activation in vivo in neurologically intact individuals. This suggests that immunoregulatory mechanisms may be present that prevent overt disease in spite of in vivo activation of PLP-reactive T cells.

A dynamical-systems model for Parkinson's disease.

The juxtaposition of hypokinetic and hyperkinetic symptoms in Parkinson's disease (PD) presents a challenge in modeling the basal ganglia. We propose a model of the striatum that can account for the mixture of symptoms seen in PD. In the model, the problem of motor planning is cast in terms of a particle in a potential, where potentials are generated internally in striatal modules, subject to afferent control. Planned movement is governed by Hamilton's equations, where potential energy is supplied by potentials expressed in the striatum. To test the model in realistic situations, a dynamic simulation of a two-link robot arm was used. Normal movement is modeled and shown to exhibit observed experimental properties. Symptoms of PD are reproduced by modeling hypothetical consequences of PD pathology.

In vivo reduction of telomere length in human antigen-reactive memory T cells.

There is a reduction in the average telomere lengths of CD4+ "memory" T cells, defined by the CD45RO+ phenotype, compared to CD54RA+ "naive" T cells. However, other studies suggest that telomerase activity often is sufficient to maintain the telomere length of certain B and T cell populations following immune activation in vivo. Thus it is uncertain whether genuine memory CD4+ T cells, defined by an immune response to specific recall antigens, would display telomeres of reduced length, or whether telomere size would be maintained. Therefore, we examined the telomere lengths of T cells responding to two common recall antigens, tetanus toxoid and Candida albicans. Telomere terminal restriction fragment length was assessed by Southern blots or by flow cytometry following in situ hybridization with telomere-specific peptide nucleic acid probes. For the five subjects tested, the Candida- or tetanus-reactive memory T cell populations demonstrated a significant reduction of telomere length even when compared to the phenotypically defined memory CD45RO+ T cell populations isolated from peripheral blood mononuclear cells. This finding suggests that telomerase activity does not fully compensate for the effects of in vivo activation and proliferation of some antigen-specific CD4+ T cell populations. This may contribute to immune senescence.

Long-term growth in vitro of human cerebrospinal fluid T lymphocytes.

Investigations of central nervous system cellular immune reactivity in human disease, as reflected in the responses of cerebrospinal fluid lymphocytes, have been limited primarily due to the low numbers of cerebrospinal fluid lymphocytes available during routine diagnostic lumbar punctures in normal individuals and most patients with demyelinating diseases. We report the use of a T-cell growth factor generated by by phytochemagglutinin-stimulated, irradiated normal peripheral blood lymphocytes to maintain long-term proliferating cultures of human cerebrospinal fluid lymphocytes. Cerebrospinal fluid lymphocytes. Cerebrospinal fluid T-cell cultures were initiated from 10 to 14 cerebrospinal fluid samples with up to 5000-fold expansion of initial cell numbers. Few, if any, macrophage or surface immunoglobulin-bearing cells were present, while 80 to 90% of the cultured cells were T cells as demonstrated by rosette formation with sheep red blood cells. Mixed lymphocyte cultures with cultured cerebrospinal fluid T cells and irradiated, freshly isolated allogeneic peripheral blood lymphocytes yielded a positive response in four of the five cultures tested.