Sympathetic Innervation of White Adipose Tissue: to Beige or Not to Beige?

Obesity research progresses in understanding neuronal circuits and adipocyte biology to regulate metabolism. However, the interface of neuro-adipocyte interaction is less studied. We summarize the current knowledge of adipose tissue innervation and interaction with adipocytes and emphasize adipocyte transitions from white to brown adipocytes and vice versa. We further highlight emerging concepts for the differential neuronal regulation of brown/beige versus white adipocyte and the interdependence of both for metabolic regulation.

Preparations for a European R&D roadmap for an inertial fusion demo reactor

A European consortium of 15 laboratories across nine nations have worked together under the EUROFusion Enabling Research grants for the past decade with three principle objectives. These are: (a) investigating obstacles to ignition on megaJoule-class laser facilities; (b) investigating novel alternative approaches to ignition, including basic studies for fast ignition (both electron and ion-driven), auxiliary heating, shock ignition, etc.; and (c) developing technologies that will be required in the future for a fusion reactor. A brief overview of these activities, presented here, along with new calculations relates the concept of auxiliary heating of inertial fusion targets, and provides possible future directions of research and development for the updated European Roadmap that is due at the end of 2020. This article is part of a discussion meeting issue 'Prospects for high gain inertial fusion energy (part 2)'.

Whole-beam self-focusing in fusion-relevant plasma

Fast ignition inertial confinement fusion requires the production of a low-density channel in plasma with density scale-lengths of several hundred microns. The channel assists in the propagation of an ultra-intense laser pulse used to generate fast electrons which form a hot spot on the side of pre-compressed fusion fuel. We present a systematic characterization of an expanding laser-produced plasma using optical interferometry, benchmarked against three-dimensional hydrodynamic simulations. Magnetic fields associated with channel formation are probed using proton radiography, and compared to magnetic field structures generated in full-scale particle-in-cell simulations. We present observations of long-lived, straight channels produced by the Habara-Kodama-Tanaka whole-beam self-focusing mechanism, overcoming a critical barrier on the path to realizing fast ignition. This article is part of a discussion meeting issue 'Prospects for high gain inertial fusion energy (part 2)'.

Early Data From Case Series of Tracheostomy in Patients With SARS-CoV-2

Thirty-eight tracheostomies were performed on patients with respiratory failure secondary to SARS-CoV-2 infection over the month of April at North Shore University Hospital and Lenox Hill Hospital (members of Northwell Health System in Long Island and New York City). Follow-up by May 14 revealed that 21 (55.2%) had been weaned from ventilators and 7 (18.4%) underwent decannulation. Two patients (5.3%) expired in the weeks following tracheostomy. Between the 2 institutions, 10 attending surgeons performed all of the tracheostomies using appropriate personal protective equipment, and none demonstrated seroconversion within 1 to 2 weeks of this article.

The Past, Present and Future of Facial Plastic and Reconstructive Surgery: Facelift

Facelift or rhytidectomy has been performed in some form for over 100 years. This article seeks to explore the evolution of this surgical procedure, focusing on the advances of the most recent 40 years. From minimal intervention to aggressive techniques and back to the minimally invasive again, the authors follow the journey of surgical intervention for facial rejuvenation and discuss some thoughts for the future.

Managing the Lower Eyelid Complex in the Thick-Skinned Patient

Thick skin presents a unique set of challenges within the realm of facial plastic surgery, and addressing the lower lid complex is no exception. There are several procedures for addressing the lower lids, the first and foremost being lower lid blepharoplasty. However, the remaining procedures combined with surgical techniques have exclusive implications in thick skin. Understanding the anatomy and various techniques that can be applied to thick skin can help achieve aesthetically more pleasing results in comparison to those of thin skin. As will be discussed in this article, patients with skin color of Fitzpatrick's grade III or higher have several characteristics associated with their skin, including thicker dermis as well as different patterns of aging, which have implications for addressing the lower lid complex. The senior author has extensive experience performing lower lid procedures and seeks to impart how best to understand and adapt for these differences to allow for the best aesthetic result.

Gene expression and lymphocyte population at the fetal-maternal interface in sheep pregnancies established by somatic cell nuclear transfer

The hypothesis of this study was that the leukocyte populations and expression levels of genes related to immune response, growth factors and apoptosis would be altered at the fetal-maternal interface in somatic cell nuclear transfer (SCNT)-generated sheep pregnancies. Placental and endometrial samples from sheep pregnancies established by SCNT and natural breeding (control) were collected at 45 days and at term. Expression of genes related to growth factors, apoptosis and immune response was examined using quantitative reverse transcription polymerase chain reaction. Endometrial leukocyte populations and major histocompatibility class I (MHC-I) protein expression were examined by immunohistochemistry. At term we observed altered expression of genes related to apoptosis, growth factors and immune response in placental and endometrial tissue of SCNT pregnancies. In Day-45 pregnancies there was less-pronounced abnormal expression and only genes related to apoptosis and growth factors were abnormal in the placenta. Endometrial gene expression profiles were similar to age-matched controls. Placental MHC-I protein expression was similar in SCNT and controls at 45 days but increased in the SCNT at term. The altered gene expression at the fetal-maternal interface likely contributes to the placental dysfunction and overgrowth observed in sheep SCNT pregnancies.

Absolute calibration of optical streak cameras on picosecond time scales using supercontinuum generation

We report a new method using high-stability, laser-driven supercontinuum generation in a liquid cell to calibrate the absolute photon response of fast optical streak cameras as a function of wavelength when operating at fastest sweep speeds. A stable, pulsed white light source based around the use of self-phase modulation in a salt solution was developed to provide the required brightness on picosecond time scales, enabling streak camera calibration in fully dynamic operation. The measured spectral brightness allowed for absolute photon response calibration over a broad spectral range (425-650 nm). Calibrations performed with two Axis Photonique streak cameras using the Photonis P820PSU streak tube demonstrated responses that qualitatively follow the photocathode response. Peak sensitivities were one photon/count above background. The absolute dynamic sensitivity is less than the static by up to an order of magnitude. We attribute this to the dynamic response of the phosphor being lower.

An Extubation Protocol for Angioedema

Angioedema-nonpitting edema of the mucous membranes and skin-most commonly occurs as a complication from the use of angiotensin-converting enzyme inhibitors. At our institution, the otolaryngology department has incorporated the use of the endotracheal tube cuff-leak test and bedside direct laryngoscopy to aid in timing for extubation of angioedema patients. Prospective data collection of patients presenting to the emergency department with angioedema was performed. Of 76 patients with angioedema, 9 required fiberoptic intubation. Intubation was performed at a median of 73 hours (range, 44-118). An endotracheal tube cuff-leak test was performed in 7 patients prior to extubation, and bedside direct laryngoscopy was also performed in 3 of these 7 patients to document resolution of laryngeal edema. The use of the endotracheal tube cuff-leak test and bedside direct laryngoscopy is an easy and inexpensive method to help determine eligibility for extubation in patients intubated for angioedema.

Reporting of Postoperative Pain Management Protocols in Randomized Clinical Trials of Mandibular Fracture Repair: A Systematic Review

IMPORTANCE

The control of pain associated with mandibular fractures is an important treatment outcome that affects function, adherence to treatment regimens, and patient comfort and satisfaction.

OBJECTIVE

To explore the pain management protocols reported in studies of mandibular fractures, including the reporting of quality-of-life measures.

EVIDENCE REVIEW

PubMed/MEDLINE, EMBASE, Cochrane CENTRAL, and clinicaltrials.gov were searched for randomized clinical trials published from 1970 to July 2014. We followed PRISMA reporting standards to assess study eligibility and extract data. Studies of patients older than 16 years who underwent operative mandibular fracture management were included. The primary data collected included the type of analgesic prescribed, associated adverse effects of the analgesic, method of pain assessment, and use of quality-of-life measures. A pain attentiveness score was assigned to studies based on the comprehensiveness of the information reported. Several variables were reviewed to determine the factors that predict reporting of pain-related data. Assessments of risk for bias were performed using the Cochrane Collaboration's domain-based evaluation method.

FINDINGS

The initial search identified 111 articles, of which 38 met inclusion criteria. Among the 38 reviewed articles, there were 38 trials and 1808 unique patients represented. Among the 38 articles, the procedures reported included maxillomandibular fixation only in 6 (16%), open reduction with internal fixation only in 20 (53%), and both in 12 (32%). Specific analgesics prescribed were reported in only 5 of the 38 studies (13%), and 3 of these used a combination of nonsteroidal anti-inflammatory drugs and acetaminophen (paracetamol). Thirteen studies (34%) reported pain assessments and 5 (13%) included quality-of-life measures. Geographic region was the only variable that predicted pain attentiveness, with studies from Europe (3 of 11 studies [27%]) and Asia (6 of 16 studies [38%]) most likely to have a high pain attentiveness score. A low rating was least common in the United States (2 of 5 studies [40%]) (P = .047, Fisher exact test). Most of the studies had unclear (n = 27) or high (n = 6) risks for bias in the key domains assessed.

CONCLUSIONS AND RELEVANCE

Pain management is a neglected outcome in randomized clinical trials of mandibular trauma; most studies did not describe the specific analgesics used. Many randomized clinical trials (13 [34%]) assessed pain levels among patients without providing information about the agents prescribed. The incorporation of validated pain measures and quality-of-life scores in future studies of mandibular trauma would focus attention on this key outcome measure.

A Systematic Review of Eligibility and Outcomes in Tinnitus Trials

Objective

To analyze existing tinnitus treatment trials with regard to eligibility criteria, outcome measures, study quality, and external validity and to recognize the effect of patient demographics, symptom duration, severity, and otologic comorbidity on research findings to help practitioners apply them to patient encounters.

Data Sources

Systematic literature search conducted by an information specialist for development of the American Academy of Otolaryngology—Head and Neck Surgery Foundation’s tinnitus clinical practice guideline.

Review Methods

Articles were assessed for eligibility with the PRISMA protocol (Preferred Reporting Items for Systematic Reviews and Meta-analyses) and data extracted by 2 independent investigators. Studies were assessed for methodological quality, inclusion and exclusion criteria, patient demographics, and outcome measures.

Results

A total of 147 randomized trials met inclusion criteria. Nearly all studies took place in a specialist setting. More than 50% did not explicitly define tinnitus, and 44% used a subjective severity threshold, such as “severely disturbing.” Fifty-four percent required symptom duration of at least 6 months for study eligibility, and up to 33% excluded patients with “organic” hearing loss or otologic conditions. Mean age was 52.2 years, and median follow-up was 3 months. Only 20% had a low risk of bias.

Conclusion

Randomized trials of tinnitus interventions are most applicable to older adults with tinnitus lasting ≥6 months who are evaluated in specialty settings. High risk of bias, short follow-up, and outcome reporting raise concerns about the validity of findings and may influence how clinicians apply trial results to individual patients and establish treatment expectations, thus demonstrating the need for further quality research in this field.

Gene expression profile in human skeletal muscle cells infected with human adenovirus type 36

Human adenovirus type-36 (HAdV-36) is a specific pathogen that may lead to increased adiposity and obesity. In order to evaluate the effects of HAdV-36 on gene transcription, a microarray analysis of muscle cells infected with HAdV-36 was performed. Gene expression profile was determined by microarray analysis in cultured human skeletal muscle cells with or without HAdV-36 infection. Quantitative real-time PCR (qPCR) assay was performed in selected 35 genes to verify the results of the microarray analysis. A total of 13,060 unique genes were detected in the HAdV-36 infected muscle cells infected with HAdV-36. Among them, 1,004 genes were significantly altered by using a cut-off point at fold change ≥1.5 and P value <0.05. Most of the principal 100 altered genes were involved in development, immune response, signal transduction, transcriptional regulation as well as carbohydrate, lipid and protein metabolism. Thirty-two genes (91.4%) from the 35 selected genes were confirmed by qPCR assay. In addition, HAdV-36 altered 252 genes that are associated with cancer. The study showed HAdV-36 infection upregulated host cell antiviral defense. HAdV-36 also induces changes in gene expression related to cellular signaling pathways of signal transduction, transcriptional regulation as well as carbohydrate, lipid and protein metabolism. However, it remains to be investigated if HAdV-36 infection could lead to oncogenesis.

Treatment of Laryngeal Cancer at the Brooklyn VA

Objective: 1) To compare survival outcomes in patients treated with advanced laryngeal cancer. 2)To illustrate the prevalence of tracheotomy and percutaneous endoscopic gastrostomy (PEG) placement in the organ preservation group and its implication for counseling patients.

Method: A retrospective chart review was performed from January 1999 to December 2009 of patients with larynx cancer AJCC stages III and IV at the Brooklyn VA Hospital. The endpoints examined were 2-year overall survival and disease-free survival. The secondary endpoints were the rate of salvage laryngectomy, tracheotomy, and PEG in each cohort.

Results: Kaplan-Meier survival for the surgery/RT group at 2 years was 75.6% (95% CI; 54.9% to 96.3%) and the survival for the chemo/RT group at 2 years was 62.2% (95% CI; 43.6% to 80.8%). There was no statistically significant difference in overall survival between the surgery/RT vs chemo/RT group. The laryngeal preservation rate was 19 out of 28 (68%) which was lower than the RTOG 91-11 (84%), and over half these patients required a tracheostomy (52%) or a PEG (68%).

Conclusion: Our study has not shown a significant survival difference between surgery and radiation vs chemoradiation protocols. However, chemoradiation as an organ-sparing technique does not ensure normal laryngeal function, particularly with frequent need for tracheostomy and gastrostomy. We hope our study will highlight the potential for problematic functional outcomes in these patients.

PPARgamma-independent increase in glucose uptake and adiponectin abundance in fat cells

Although thiazolidinediones (TZD) effectively improve hyperglycemia and increase adiponectin, a proinsulin-sensitizing adipokine, they also increase adipogenesis via peroxisome proliferator-activated receptor (PPAR)γ induction, which may be undesirable. Recent safety concerns about some TZD have prompted the search for next generation agents that can enhance glycemic control and adiponectin independent of PPARγ or adipogenesis. Reminiscent of TZD action, a human adenovirus, adenovirus 36 (Ad36), up-regulates PPARγ, induces adipogenesis, and improves systemic glycemic control in vivo. We determined whether this effect of Ad36 requires PPARγ and/or adipogenesis. Glucose uptake and relevant cell signaling were determined in mock-infected or human adenoviruses Ad36 or Ad2-infected cell types under the following conditions: 1) undifferentiated human-adipose-tissue-derived stem cells (hASC), 2) hASC differentiated as adipocytes, 3) hASC in presence or absence of a PPARγ inhibitor, 4) NIH/3T3 that have impaired PPARγ expression, and 5) PPARγ-knockout mouse embryonic fibroblasts. Mouse embryonic fibroblasts with intact PPARγ served as a positive control. Additionally, to determine natural Ad36 infection, human sera were screened for Ad36 antibodies. In undifferentiated or differentiated hASC, or despite the inhibition, down-regulation, or the absence of PPARγ, Ad36 significantly enhanced glucose uptake and PPARγ, adiponectin, glucose transporter 4, and glucose transporter 1 protein abundance, compared with mock or Ad2-infected cells. This indicated that Ad36 up-regulates glucose uptake and adiponectin secretion independent of adipogenesis or without recruiting PPARγ. In humans, natural Ad36 infection predicted greater adiponectin levels, suggesting a human relevance of these effects. In conclusion, Ad36 provides a novel template to metabolically remodel human adipose tissue to enhance glycemic control without the concomitant increase in adiposity or PPARγ induction associated with TZD actions.

Effect of various freezing parameters on the immediate post-thaw membrane integrity of adipose tissue derived adult stem cells

The effect of four thermal parameters on post-thaw membrane integrity of adipose tissue derived adult stem (ADAS) cells after controlled-rate freezing was investigated with the help of a two-level four-parameter (2(4)) experimental design. The four thermal parameters studied were cooling rate (CR), end temperature (ET), hold time (HT), and thawing rate (TR). Several passages, including Passage-0 (P0), Passage-1 (P1), Passage-2 (P2), Passage-3 (P3), and Passage-4 (P4), obtained from the suspended culture of stromal vascular fraction (SVF) of the ADAS cells were used for this study. The two levels (low and high) of the four parameters [CR (1 and 40 degrees C/min); ET (-80 and -20 degrees C); HT (1 and 15 min); and TR (10 and 200 degrees C/min)] are chosen in such a way that they enclosed all parameter values possible using commercially available controlled-rate freezing equipment. Individual effect of each parameter on the immediate post-thaw membrane integrity was determined through the calculation of parameter effect values (E), and any synergy among the parameters on post-thaw membrane integrity was assessed through the calculation of two or more parameter interaction effect values (I). Nonlinearity in the experimental results was represented through the calculation of curvature value (CV). The results suggest that for 99% confidence level the parameters CR and ET have considerable effect on post-thaw membrane integrity of all passages of ADAS cells. A significant individual effect of TR was observed with P3 and P4 cells and a significant two-parameter interaction was observed between CR-ET for all passages. These observed results will be used as a basis to further develop freezing storage protocols of ADAS cells.

MRI assessment of microvascular characteristics in experimental breast tumors using a new blood pool contrast agent (MS-325) with correlations to histopathology

A new contrast medium, MS-325, was compared to albumin-(Gd-DTPA)(30) in 18 chemically induced rat breast tumors based on quantitative estimates of microvascular permeability (K(PS)) and fractional plasma volume (fPV) using a two-compartment bidirectional model. No significant correlation was found between MS-325-enhanced microvascular assays with either tumor grade or with microvascular counts (MVCs). In comparison, the correlation coefficient between K(PS) and histologic tumor grade using albumin-(Gd-DTPA)(30) (r =.58) was statistically significant (P <.01). Also, using albumin-(Gd-DTPA)(30), a significant correlation (r =.55, P <.05) was observed between the K(PS) and MVC, a biomarker of angiogenesis. Correlations between fPV and MVC were not statistically significant for either contrast medium. In conclusion, using MS-325, no significant correlations between the MR-estimated permeability values or plasma volumes were observed in experimental breast tumors with either the histologic tumor grade or MVC. This analysis confirms our previous determination that capillary permeability estimates, using a prototype large molecular contrast medium, albumin-(Gd-DTPA)(30), correlate significantly with both histologic tumor grade and MVC.

Tumor microvascular characterization using ultrasmall superparamagnetic iron oxide particles (USPIO) in an experimental breast cancer model

The diagnostic potential of ultrasmall superparamagnetic iron oxide particles (USPIO) for quantitative tumor microvessel characterization was assessed by kinetic analysis of dynamic magnetic resonance imaging (MRI) in a rodent breast cancer model. Microvascular characteristics (transendothelial permeability (K(PS)) and fractional plasma volume (fPV)) were estimated in 32 female Sprague Dawley rats, bearing breast tumors of varying malignancy. These values were compared to a prototype macromolecular contrast medium standard, albumin-(GdDTPA)(30). Transendothelial permeability (K(PS)) correlated significantly (P < 0.05) with the tumor grade (Scarff-Bloom-Richardson (SBR) score) for the USPIO (r = 0.36), as well as for the reference macromolecule, albumin-(GdDTPA)(30) (r = 0.54). Estimates for the fPV did not show a statistically significant correlation with the tumor grade for either contrast medium. In conclusion, USPIO-enhanced MRI data were capable to characterize tumor microvessel properties in this breast cancer model: microvascular permeability (determined using USPIO) correlated significantly with tumor grade. Thus, quantitative estimation of microvascular characteristics in tumors could provide a surrogate of new vessel formation (angiogenesis) and thus a further important clinical indication for USPIO, in addition to MR angiography. J. Magn. Reson. Imaging 2001;13:882-888.

Assessment of a rapid clearance blood pool MR contrast medium (P792) for assays of microvascular characteristics in experimental breast tumors with correlations to histopathology

The diagnostic potential of a new rapid clearance blood pool contrast medium (P792; MW = 6.47 kDa) for the MR assessment of microvessel characteristics was assessed in 42 chemically-induced breast tumors, with comparisons to albumin-(Gd-DTPA). Microvessel characteristics, including the transendothelial permeability (K(PS)) and the fractional blood volume (fPV), were estimated by using dynamic MR data fit to a bidirectional two-compartment model. The MR-derived estimates for K(PS) and fPV using each contrast agent were compared, and assays using each contrast agent were correlated to the histologic tumor grade (SBR score) and the microvascular density (MVD) counts. Using P792-enhanced data, neither K(PS) nor fPV showed a statistically significant correlation with the tumor grade or the MVD (P >.05). Conversely, using albumin-(GdDTPA)(30), K(PS) values correlated significantly with the histologic tumor grade (r =.55; P <.0005) and the MVD (r =.34, P <.05), whereas no correlation was established for fPV. In conclusion, based on P792 data no correlation between tumor microvascular characteristics and histologic markers (SBR score or MVD) was found in this breast tumor model. Our analysis suggests that contrast media of relatively large (on the order of 90 kDa) molecular size, such as albumin-(GdDTPA)(30), are more accurate for the characterization of tumor microvessels.

MR imaging characterization of microvessels in experimental breast tumors by using a particulate contrast agent with histopathologic correlation

PURPOSE

To define the diagnostic potential of magnetic resonance (MR) imaging enhanced with ultrasmall superparamagnetic iron oxide (USPIO) particles for the quantitative characterization of tumor microvasculature.

MATERIALS AND METHODS

NC100150 injection, a USPIO in clinical trials, and albumin-(Gd-DTPA)(30) were compared at MR imaging on sequential days in the same 19 rats with mammary tumors. Kinetic analysis of dynamic T1-weighted three-dimensional spoiled gradient-recalled imaging data with a two-compartment bidirectional model yielded MR imaging estimates of microvascular permeability (K(PS)) and fractional plasma volume (fPV) for each contrast medium.

RESULTS

Strongly positive and significant correlations were observed between MR imaging-derived K(PS )estimates and histologic tumor grade with either the soluble albumin-(Gd-DTPA)(30) (r = 0.88; P <.001) or larger particulate USPIO (r = 0.82; P <.001). A significant correlation (P <.05) was observed with each contrast medium between K(PS) and the histologic microvascular density (MVD), an angiogenesis indicator. Despite the considerable difference in molecule and particle sizes, no significant difference was observed in the MR imaging-derived mean permeability values generated with the two contrast media.

CONCLUSION

USPIO, a macromolecular particulate MR imaging contrast agent, can be applied successfully to characterize tumor microvessels in animals. USPIO-derived K(PS) correlated strongly with histopathologic tumor grade, MVD, and K(PS) values derived by using albumin-(Gd-DTPA)(30) in the same tumors.

Practices that minimize trauma to the genital tract in childbirth: a systematic review of the literature

BACKGROUND

Trauma to the genital tract commonly occurs at birth, and can cause short- and long-term morbidity. Clinical measures to reduce its occurrence have not been fully identified.

METHODS

A systematic review of the English language literature was conducted to describe the current state of knowledge on reduction of genital tract trauma before planning a large randomized controlled trial of ways to prevent such trauma. Randomized trials and other published reports were identified from relevant databases and hand searches. Studies were reviewed and assessed using a structured format.

RESULTS

A total of 77 papers and chapters were identified and placed into 5 categories after critical review: 25 randomized trials, 4 meta-analyses, 4 prospective studies, 36 retrospective studies, and 8 descriptions of practice from textbooks. The available evidence is conclusive in favor of restricted use of episiotomy. The contribution of maternal characteristics and attitudes to intact perineum has not been investigated. Several other topics warrant further study, including maternal position, style of pushing, and antenatal perineal massage. Strong opinions and sparse data exist regarding the role of hand maneuvers by the birth attendant for perineal management and birth of the baby. This became the topic of the planned randomized controlled trial, which was completed; results will be published soon.

CONCLUSIONS

The case for restricting the use of episiotomy is conclusive. Several other clinical factors warrant investigation, including the role of hand maneuvers by the birth attendant in preventing birth trauma. A large randomized controlled trial will report on this topic.

Temporal lymphoreticular changes caused by ts1, a paralytogenic mutant of Moloney murine leukemia virus TB

Inoculation of newborn FVB/N mice with ts1, a mutant of Moloney murine leukemia virus TB, induced severe thymic atrophy, spongiform polioencephalomyelopathy, and fatal posterior paralysis of the affected mice 35-40 days after inoculation. During the early course of infection viral replication was found in the spleen and, more importantly, within the thymus. Of these organs, the thymus was affected most severely by ts1-infection. Thymic weights of infected mice decreased markedly during disease progression, culminating in severe atrophy at the time of paralysis. During the first 10 days after inoculation, the virus replicated within the endothelial lining of splenic and thymic capillaries and was released albuminally into the basement membrane before spreading outwardly into perithelial, epithelial, and reticuloendothelial cells. Within these cells there was productive viral replication and subsequent dissemination of the virus to the thymic T cell population. Early infection (up to 10 days after inoculation) of the thymus induced an increase in thymocytic mitosis, followed by a progressive increase in thymocytic death between 15 and 35 days after inoculation. Thymuses from paralyzed mice killed 30-39 days after inoculation, demonstrated pronounced involution, characterized by loss of lobular architecture, effacement of the cortex and medulla, severe depletion of thymocytes, and partial or complete loss of Hassall's corpuscles. Immunohistochemistry for viral antigens showed positive labeling of splenic megakaryocytes, reticuloendothelial cells, and thymocytes in mitosis, and reticulo-epithelial-endothelial cells of the thymus. The thymic phase of viral replication appeared to be crucial for development of neurological lesions and posterior paralysis.

Alteration from T- to B-cell tropism reduces thymic atrophy and cytocidal effects in thymocytes but not neurovirulence induced by ts1, a mutant of Moloney murine leukemia virus TB

The ts1 mutant of Moloney murine leukemia virus TB causes degenerative neurologic and immunologic disease in mice, characterized by development of spongiform encephalomyelopathy resulting in hindlimb paralysis, marked thymic atrophy associated with immunodeficiency, and generalized body wasting. To investigate the pathogenesis of the thymic atrophy caused by ts1, we constructed a chimeric virus, ts1-Cas(NS), in which a major portion of the U3 region of the long terminal repeat of ts1, a T-lymphotropic and neurovirulent murine leukemia virus, was replaced by the corresponding U3 region of Cas-Br-E, a B-lymphotropic and neurovirulent murine leukemia virus. In FVB/N mice, ts1-Cas(NS) induced paralytic and wasting disease with incidence, severity, and latency similar to that induced by ts1, but it failed to cause thymic atrophy as severe as that observed in ts1-infected mice. Furthermore, thymocytes cultured from ts1-Cas(NS)-infected mice died at a much slower rate than those of ts1-infected mice. The U3 substitution in ts1-Cas(NS) specifically diminished the ability of the virus to replicate in the thymus, whereas viral replication in the spinal cord was not significantly affected; thus, neurovirulence was not changed. The correlation of reduced thymic atrophy with decreased thymic viral titers and the decreased ability of ts1-Cas(NS) to cause thymocyte death in mice suggest strongly that the marked thymic atrophy in ts1-infected mice is not an indirect effect occurring secondary to neurodegenerative and wasting disease but is a direct cytopathic effect of high-level viral replication in the thymus.

Toxoplasmosis in two cats with inflammatory intestinal disease

Lymphocytic-plasmacytic enteritis, a chronic inflammatory intestinal disease, was diagnosed in 2 cats. In 1 cat, recurrence of clinical signs after initiating treatment was attributed to relapse of the inflammatory intestinal disease, but was found to be attributable to relapsing toxoplasmosis secondary to immunosuppressive drug therapy. Treatment with clindamycin resolved the recurrent toxoplasmosis. In the second cat, clinical signs of toxoplasmosis did not develop, but serologic testing yielded evidence of active toxoplasmosis. Treatment with clindamycin caused the titers to decrease. Relapsing toxoplasmosis may be responsible for apparent resistance to treatment in cats for inflammatory intestinal disease being treated with immunosuppressive drugs.

Panfibrinonecrotic colitis in a dog treated by subtotal colectomy

A dog with signs of small intestinal disease developed signs of severe large intestinal disease after being treated with multiple agents. Endoscopy and biopsy revealed total destruction of the colonic mucosa, which necessitated total parenteral nutrition plus subtotal colectomy. It was hypothesized that the multiple prior treatments led to an overgrowth of toxigenic or cytotoxic bacteria, which caused this colonic mucosal destruction.

Site-directed mutagenesis of the codon for Ile-25 in gPr80env alters the neurovirulence of ts1, a mutant of Moloney murine leukemia virus TB

ts1, a spontaneous temperature-sensitive mutant of Moloney murine leukemia virus TB, causes hind-limb paralysis in mice. A Val-25----Ile substitution in gPr80env is responsible for temperature sensitivity, inefficient processing of gPr80env, and neurovirulence. In this study, the Ile-25 in gPr80env was replaced with Thr, Ala, Leu, Gly, and Glu by site-directed mutagenesis of the codon for Ile-25 to generate a new set of mutant viruses, i.e., ts1-T, -A, -L, -G, and -E, respectively. The phenotypic characteristics of these mutant viruses differed from those of ts1. For each mutant, the degree of temperature sensitivity was correlated with the degree of inefficient processing of gPr80env, and the following rank order was observed for both parameters: ts1-E greater than ts1-G greater than ts1-L greater than ts1-A greater than ts1 greater than ts1-T. In FVB/N mice, mutant viruses of low and intermediate temperature sensitivity and inefficiency in processing of gPr80env were neurovirulent and consistently caused mutant-specific disease profiles: ts1-T caused severe whole-body tremor, ts1-A generally caused hind-limb paralysis, and ts1-L generally caused a delayed-onset paraparesis. By 150 days postinfection, FVB/N mice that were infected with ts1-G and -E, mutants of high temperature sensitivity and inefficiency in processing of gPr80env, had lymphoid leukemia instead of a neurological disease. These results suggest that the dynamics of gPr80env processing are important in determining the neurovirulent phenotype in vivo.

Nonspecific cytotoxic cells in fish (Ictalurus punctatus). III. Biophysical and biochemical properties affecting cytolysis

Nonspecific cytotoxic cells (NCC) from the catfish (Ictalurus punctatus) may comprise a population of cells that are responsible for cellular immunity in the fish. NCC kill a wide variety of transformed target cells, and previous studies have indicated that NCC share properties with mammalian natural killer cells. In the present study, many biophysical and biochemical properties of NCC were defined. NCC were nylon wool nonadherent and adherent. NCC activity was also enriched in plastic nonadherent cells. NCC were nonphagocytic (for carbonyl iron), and they did not bind to Sephadex G-10. Characterization of NCC by density gradient centrifugation indicated that they comprise a relatively homogenous population of cytolytic cells that band at 45.5% Percoll. Moderate to high doses (500-2500 R) of X-irradiation produced a stimulatory effect on NCC lysis of labeled target cells. Additional studies indicated that a soluble suppressor protein in catfish serum (CFS) regulated NCC activity. This S. aureus protein A binding component isolated from CFS suppressed NCC activity. Analysis by SDS-PAGE indicated that the soluble regulatory protein had properties similar to immunoglobulin. These data indicate that NCC share some biophysical properties with mammalian natural killer cells. In addition, NCC appear to be under partial cell regulation by a radiation sensitive suppressor cell and also by a soluble regulator serum immunoglobulin component.

Cystic fibrosis ciliary dyskinesia substances and pulmonary disease. Effects of ciliary dyskinesia substances on neutrophil movement in vitro

Cultured mononuclear cells (MNC) from individuals homozygous or heterozygous for the defective gene causing the inherited disease cystic fibrosis (CF) synthesize three unusual "mediators" termed ciliary dyskinesia substances (CDS), which markedly affect tracheal mucociliary systems in vitro. MNC cultures from normal healthy controls do not accumulate any CDS, whereas MNC cultures from non-CF patients controls with pulmonary disease synthesized at least one CDS. The possible involvement of the CDS in pulmonary disease is being investigated. In this study, we sought to determine whether the CDS could be chemoattractants for polymorphonuclear neutrophils (PMN), since they have characteristics in common with known chemoattractants generated by alveolar macrophages. Our analyses of crude MNC culture supernates indicated that cultures from both CF genotypes accumulate significantly higher levels of PMN chemoattractants than do analogous cultures from normal healthy controls. CF homozygote MNC also generated more activity than MNC from patient controls with chronic pulmonary disease. Fractionation of MNC culture supernates by gel permeation chromatography and characterization of active fractions demonstrated six distinct PMN chemoattractants in cultures from CF genotypes; five were also present in patient control and four in normal healthy control cultures. The excessive chemoattractant activity in MNC cultures from CF genotypes and patient controls was due to several different substances produced by monocytes: (a) two components of 1,000-3,500 mol wt. (b) two fragments of C5, and (c) a fragment of C3. One C5 fragment had ciliary dyskinesia activity, the other did not. The C3 fragment chemoattractant also had ciliary dyskinesia activity and was not found in MNC cultures from patient controls. A third CDS, Which is CF-specific (5,000 mol wt), was neither chemotactic not chemokinetic and did not inhibit random PMN migration; however, fractions containing this CF-specific CDS completely inhibited PMN chemotaxis in response to three different chemoattractants. We conclude that all of the CDS can potentially play a role in the pathophysiology of lung disease, as judged by their effects on PMN movement in vitro.

Potential organ- or tumor-imaging agents XX: Ovarian imaging with 19-radioiodinated cholesterol

Cholesterol is stored in the ovaries where it is a precursor in the biosynthesis of the female sex hormones progesterone and estradiol. The purpose of this study was to determine whether a radioiodinated analog of cholesterol, 125I-labeled 19-iodocholesterol, would mimic cholesterol in this capacity and thus offer a means for imaging the ovaries of intact animals. Aside from the thyroid, the adrenal glands and ovaries of the female rat retained the highest levels of radioactivity at 4 days following the intravenous administration of 125I-labeled 19-iodocholesterol. Moreover, the levels of radioactivity were sufficient to obtain clear images of the adrenal glands and ovaries with a small animal scanner. Folch analysis of these tissues revealed that > 80% of the radioactivity was associated with the sterol ester fraction.