The Overt Aggression Scale for the objective rating of verbal and physical aggression

The authors describe the design and reliability of a rating scale that measures aggressive behaviors in adults and children. On the Overt Aggression Scale (OAS), aggression is divided into four categories: verbal aggression, physical aggression against objects, physical aggression against self, and physical aggression against others. In addition, specific interventions related to each aggressive event can be recorded on the OAS. The clinical and research applications of this scale are discussed.

Specific probiotic therapy attenuates antibiotic induced visceral hypersensitivity in mice

BACKGROUND AND AIMS

Abdominal pain and discomfort are common symptoms in functional disorders and are attributed to visceral hypersensitivity. These symptoms fluctuate over time but the basis for this is unknown. Here we examine the impact of changes in gut flora and gut inflammatory cell activity on visceral sensitivity.

METHODS

Visceral sensitivity to colorectal distension (CRD) was assessed at intervals in healthy mice for up to 12 weeks, and in mice before and after administration of dexamethasone or non-absorbable antibiotics with or without supplementation with Lactobacillus paracasei (NCC2461). Tissue was obtained for measurement of myeloperoxidase activity (MPO), histology, microbiota analysis, and substance P (SP) immunolabelling.

RESULTS

Visceral hypersensitivity developed over time in healthy mice maintained without sterile precautions. This was accompanied by a small increase in MPO activity. Dexamethasone treatment normalised MPO and CRD responses. Antibiotic treatment perturbed gut flora, increased MPO and SP immunoreactivity in the colon, and produced visceral hypersensitivity. Administration of Lactobacillus paracasei in spent culture medium normalised visceral sensitivity and SP immunolabelling, but not intestinal microbiota counts.

CONCLUSION

Perturbations in gut flora and in inflammatory cell activity alter sensory neurotransmitter content in the colon, and result in altered visceral perception. Changes in gut flora may be a basis for the variability of abdominal symptoms observed in functional gastrointestinal disorders and may be prevented by specific probiotic administration.

Clinical and histologic observations of sites implanted with intraoral autologous bone grafts or allografts. 15 human case reports

The cases reported in this paper were treated at 7 different clinical centers and present clinical and histologic observations from 15 patients and 21 human biopsies. The biopsies were taken from extraction sockets or dental implant sites which were grafted with either autologous intra-oral bone (6 sites), demineralized freeze-dried bone (DFDBA) (7 sites), or mineralized freeze-dried bone (MFDBA) (7 sites), or a combination of autologous bone, DFDBA and a barrier membrane (1 site). Six sites were grafted with DFDBA and augmented with expanded polytetrafluoroethylene (ePTFE) barrier membranes. Biopsies for histological evaluation were taken 4 to 13 months after implantation. A bone scoring system of 0 to 4 was used to evaluate the sections for dead implanted particles or the presence of vital bone. A bone score of 3 indicated the presence of dead implant material, blood vessels, islands of cartilage, osteoblasts, and new bone formation. A score of 4 indicated total replacement of the implanted material by the host bone. The average bone score for sites which received autologous bone was 2.33; for DFDBA sites, 0.98; and MFDBA was 0.18. The over-riding histologic characteristic of sites implanted with DFDBA or MFDBA was retention of non-vital graft particles within fibrous connective tissue. Biopsies taken adjacent to the host bed demonstrated incorporation of the allografts (osteoconduction). Sites grafted with autologous bone chips also demonstrated non-vital bone chips surrounded by vital host bone (osteoconduction). Sites which received barrier membranes did not appear to improve or impair bone healing of the augmented sites. Autologous bone chips harvested from within the oral cavity as well as allografts may serve as biologic fillers, but do not apparently contribute to osteoinduction. Autologous bone will eventually be resorbed and replaced by the host. DFDBA and MFDBA are resorbed very slowly and apparently do not contribute to osteoinduction. Allografts apparently are not resorbed by osteoclasts and therefore their continued use around dental implants is questioned.

Cigarette smoking increases the risk of albuminuria among subjects with type I diabetes

The effect of cigarette smoking on diabetic renal and retinal complications was evaluated in 359 young subjects with insulin-dependent diabetes mellitus. The prevalence of increased albumin excretion rates was 2.8 times higher in smokers than nonsmokers. Mean glycohemoglobin levels and duration of diabetes were also significant factors in the development of diabetic nephropathy and retinopathy in a logistic regression model. Smoking remained a significant factor in the logistic regression model for albuminuria (but not retinopathy) when controlled for glycohemoglobin level, duration of diabetes, age, gender, and blood pressure. The progression of albuminuria and of retinopathy was also greater in smokers. Albuminuria improved significantly when subjects ceased smoking. It is concluded that cigarette smoking is an independent risk factor and is associated with the development and progression of early diabetic renal damage (albuminuria) and with the worsening of retinal disease in young subjects with diabetes.

The prolonged gastrointestinal syndrome in rhesus macaques: the relationship between gastrointestinal, hematopoietic, and delayed multi-organ sequelae following acute, potentially lethal, partial-body irradiation

The dose response relationship for the acute gastrointestinal syndrome following total-body irradiation prevents analysis of the full recovery and damage to the gastrointestinal system, since all animals succumb to the subsequent 100% lethal hematopoietic syndrome. A partial-body irradiation model with 5% bone marrow sparing was established to investigate the prolonged effects of high-dose radiation on the gastrointestinal system, as well as the concomitant hematopoietic syndrome and other multi-organ injury including the lung. Herein, cellular and clinical parameters link acute and delayed coincident sequelae to radiation dose and time course post-exposure. Male rhesus Macaca mulatta were exposed to partial-body irradiation with 5% bone marrow (tibiae, ankles, feet) sparing using 6 MV linear accelerator photons at a dose rate of 0.80 Gy min(-1) to midline tissue (thorax) doses in the exposure range of 9.0 to 12.5 Gy. Following irradiation, all animals were monitored for multiple organ-specific parameters for 180 d. Animals were administered medical management including administration of intravenous fluids, antiemetics, prophylactic antibiotics, blood transfusions, antidiarrheals, supplemental nutrition, and analgesics. The primary endpoint was survival at 15, 60, or 180 d post-exposure. Secondary endpoints included evaluation of dehydration, diarrhea, hematologic parameters, respiratory distress, histology of small and large intestine, lung radiographs, and mean survival time of decedents. Dose- and time-dependent mortality defined several organ-specific sequelae, with LD50/15 of 11.95 Gy, LD50/60 of 11.01 Gy, and LD50/180 of 9.73 Gy for respective acute gastrointestinal, combined hematopoietic and gastrointestinal, and multi-organ delayed injury to include the lung. This model allows analysis of concomitant multi-organ sequelae, thus providing a link between acute and delayed radiation effects. Specific and multi-organ medical countermeasures can be assessed for efficacy and interaction during the concomitant evolution of acute and delayed key organ-specific subsyndromes.

A nonhuman primate model of the hematopoietic acute radiation syndrome plus medical management

The development of medical countermeasures against the hematopoietic subsyndrome of the acute radiation syndrome requires well characterized and validated animal models. The model must define the radiation dose- and time-dependent relationships for mortality and major signs of morbidity to include other organ damage that may contribute to morbidity and mortality. Herein, the authors define these parameters for a nonhuman primate exposed to total body radiation and administered medical management. A blinded, randomized study (n = 48 rhesus macaques) determined the lethal dose-response relationship using bilateral 6 MV linear accelerator photon radiation to doses in the range of 7.20 to 8.90 Gy at 0.80 Gy min(-1). Following irradiation, animals were monitored for complete bloodcounts, body weight, temperature, diarrhea, and hydration status for 60 d. Animals were administered medical management consisting of intravenous fluids, prophylactic antibiotics, blood transfusions, anti-diarrheals, analgesics, and nutrition. The primary endpoint was survival at 60 d post-irradiation; secondary endpoints included hematopoietic-related parameters, number of transfusions, incidence of documented infection, febrile neutropenia, severity of diarrhea, mean survival time of decedents, and tissue histology. The study defined an LD30/60 of 7.06 Gy, LD50/60 of 7.52 Gy, and an LD70/60 of 7.99 Gy with a relatively steep slope of 1.13 probits per linear dose. This study establishes a rhesus macaque model of the hematopoietic acute radiation syndrome and shows the marked effect of medical management on increased survival and overall mean survival time for decedents. Furthermore, following a nuclear terrorist event, medical management may be the only treatment administered at its optimal schedule.

Receptor properties of two varicella-zoster virus glycoproteins, gpI and gpIV, homologous to herpes simplex virus gE and gI

The varicella-zoster virus (VZV) genome contains 70 reading frames (ORF), 5 of which encode the glycoproteins gpI, gpII, gpIII, gpIV, and gpV. ORF 67 and 68 lie adjacent to each other in the unique short region of the VZV genome and code for gpIV and gpI, respectively. These two genes, which are contained within the HindIII C fragment of the VZV genome, were subcloned in the correct orientation downstream from the promoter regions of the eukaryotic expression vectors pCMV5 and pBJ. After transfection, 5 to 20% of the Cos cells bound antibody specific for the given glycoprotein. In this study, it was shown that only the cells transfected with the gpI construct bound to the Fc fragment of human immunoglobulin G. Neither the transfected gpIV gene product nor the vector only bound to the Fc fragment. Thus, VZV gpI is confirmed to be the VZV-encoded Fc-binding glycoprotein. Like the wild-type form of gpI expressed in VZV-infected cells, gpI precipitated from transfected cells contained both N-linked and O-linked glycans and was heavily sialated. In addition, the transfected gpI gene product was phosphorylated both in cell culture and in protein kinase assays by mammalian casein kinases I and II. Extensive computer-assisted analyses of the VZV gpI sequence, as well as those of alphaherpesviral homolog glycoproteins, disclosed properties similar to those of other cell surface receptors; these included (i) exocytoplasmic regions rich in cysteine residues, (ii) membrane-proximal regions with potential O-linked glycosylation sites, and (iii) cytoplasmic domains with consensus phosphorylation sites.

Foot-and-mouth disease virus utilizes an autophagic pathway during viral replication

Foot-and-mouth disease virus (FMDV) is the type species of the Aphthovirus genus within the Picornaviridae family. Infection of cells with positive-strand RNA viruses results in a rearrangement of intracellular membranes into viral replication complexes. The origin of these membranes remains unknown; however induction of the cellular process of autophagy is beneficial for the replication of poliovirus, suggesting that it might be advantageous for other picornaviruses. By using confocal microscopy we showed in FMDV-infected cells co-localization of non-structural viral proteins 2B, 2C and 3A with LC3 (an autophagosome marker) and viral structural protein VP1 with Atg5 (autophagy-related protein), and LC3 with LAMP-1. Importantly, treatment of FMDV-infected cell with autophagy inducer rapamycin, increased viral yield, and inhibition of autophagosomal pathway by 3-methyladenine or small-interfering RNAs, decreased viral replication. Altogether, these studies strongly suggest that autophagy may play an important role during the replication of FMDV.

Dominant integration locus drives continuous diversification of plant immune receptors with exogenous domain fusions

BACKGROUND

The plant immune system is innate and encoded in the germline. Using it efficiently, plants are capable of recognizing a diverse range of rapidly evolving pathogens. A recently described phenomenon shows that plant immune receptors are able to recognize pathogen effectors through the acquisition of exogenous protein domains from other plant genes.

RESULTS

We show that plant immune receptors with integrated domains are distributed unevenly across their phylogeny in grasses. Using phylogenetic analysis, we uncover a major integration clade, whose members underwent repeated independent integration events producing diverse fusions. This clade is ancestral in grasses with members often found on syntenic chromosomes. Analyses of these fusion events reveals that homologous receptors can be fused to diverse domains. Furthermore, we discover a 43 amino acid long motif associated with this dominant integration clade which is located immediately upstream of the fusion site. Sequence analysis reveals that DNA transposition and/or ectopic recombination are the most likely mechanisms of formation for nucleotide binding leucine rich repeat proteins with integrated domains.

CONCLUSIONS

The identification of this subclass of plant immune receptors that is naturally adapted to new domain integration will inform biotechnological approaches for generating synthetic receptors with novel pathogen "baits."

Traditional measures of normal anal sphincter function using high-resolution anorectal manometry (HRAM) in 115 healthy volunteers

BACKGROUND

High-resolution anorectal manometry (HRAM) is a relatively new method for collection and interpretation of data relevant to sphincteric function, and for the first time allows a global appreciation of the anorectum as a functional unit. Historically, traditional anal manometry has been plagued by lack of standardization and healthy volunteer data of variable quality. The aims of this study were: (i) to obtain normative data sets for traditional measures of anorectal function using HRAM in healthy subjects and; (ii) to qualitatively describe novel physiological phenomena, which may be of future relevance when this method is applied to patients.

METHODS

115 healthy subjects (96 female) underwent HRAM using a 10 channel, 12F solid-state catheter. Measurements were performed during rest, squeeze, cough, and simulated defecation (push). Data were displayed as color contour plots and analysed using a commercially available manometric system (Solar GI HRM v9.1, Medical Measurement Systems). Associations between age, gender and parity were subsequently explored.

KEY RESULTS

HRAM color contour plots provided clear delineation of the high-pressure zone within the anal canal and showed recruitment during maneuvers that altered intra-anal pressures. Automated analysis produced quantitative data, which have been presented on the basis of gender and parity due to the effect of these covariates on some sphincter functions. In line with traditional manometry, some age and gender differences were seen. Males had a greater functional anal canal length and anal pressures during the cough maneuver. Parity in females was associated with reduced squeeze increments.

CONCLUSIONS & INFERENCES

The study provides a large healthy volunteer dataset and parameters of traditional measures of anorectal function. A number of novel phenomena are appreciated, the significance of which will require further analysis and comparisons with patient populations.

The acute gastrointestinal subsyndrome of the acute radiation syndrome: a rhesus macaque model

The development of medical countermeasures against the acute gastrointestinal subsyndrome of the acute radiation syndrome in humans requires well characterized and validated animal models. These models must adhere to the criteria of the U.S. Food and Drug Administration's Animal Rule and consider the natural history and clinical context of the human radiation response and treatment in the nuclear terrorist scenario. The models must define the radiation dose- and time-dependent relationships for mortality and major signs of morbidity, including concurrent damage in other organs, such as the bone marrow, that may contribute to the overall mortality and morbidity. There are no such models of the gastrointestinal syndrome in response to total-body irradiation in the nonhuman primate. Herein, these parameters are defined for the rhesus macaque exposed to potentially lethal doses of radiation and administered medical management. Rhesus macaques (n = 69) were exposed bilaterally to 6 MV linear accelerator-derived photon total body irradiation to midline tissue (thorax) doses ranging from 10.0 to 14.0 Gy at 0.80 Gy min(-1). Following irradiation, all animals were administered supportive care consisting of fluids, anti-emetics, anti-diarrheal medication, antibiotics, blood transfusions, analgesics, and nutrition. The primary endpoint was survival at 15 d post-irradiation. Secondary endpoints included indices of dehydration, diarrhea, weight loss, hematological parameters, cellular histology of the small and large intestine, and mean survival time of decedents. Mortality within the 15-d in vivo study defined the acute gastrointestinal syndrome and provided an LD30/15 of 10.76 Gy, LD50/15 of 11.33 Gy, and an LD70/15 of 11.90 Gy. Intestinal crypt and villus loss were dose- and time-dependent with an apparent nadir 7 d post-irradiation and recovery noted thereafter. Severe myelosuppression and thrombocytopenia were noted in all animals, requiring the administration of antibiotics and blood transfusions. The model defines the dose response relationship and time course of acute gastrointestinal syndrome-induced morbidity and mortality in the rhesus macaque.

Defining the full therapeutic potential of recombinant growth factors in the post radiation-accident environment: the effect of supportive care plus administration of G-CSF

Radiation accidents are uncontrolled and ill-defined, the exposure is nonuniform and may be partial body, forecasting a variable dose distribution and sparing of hematopoietic stem cells. We propose that the "best" treatment protocol available now for severely irradiated personnel with acute hematopoietic syndrome is the combination of supportive care and administration of recombinant cytokines as soon as possible after irradiation. Herein, we demonstrate the significant effect of G-CSF administration on lethally irradiated canines. G-CSF administered early and continuously after irradiation increased neutrophil recovery and survival over a lethal and supralethal dose range. The respective LD50/30 for the control, supportive care-alone cohorts of 338 cGy, was increased to 488 cGy with administration of G-CSF. Clearly, the use of supportive care and G-CSF enhanced recovery of myelopoiesis and survival after lethal doses of irradiation.

Urinary and serum mutagenicity studies with rats implanted with depleted uranium or tantalum pellets

During the 1991 Persian Gulf War several US military personnel were wounded by shrapnel fragments consisting of depleted uranium. These fragments were treated as conventional shrapnel and were not surgically removed to spare excessive tissue damage. Uranium bioassays conducted over a year after the initial uranium injury indicated a significant increase in urine uranium levels above natural background levels. The potential mutagenic effects of depleted uranium are unknown. To assess the potential mutagenic effects of long-term exposure to internalized depleted uranium, Sprague-Dawley rats were implanted with depleted uranium and their urine and serum were evaluated for mutagenic potential at various times after pellet implantation using the Ames Salmonella reversion assay. Tantalum, an inert metal widely used in prosthetic devices was used for comparison. Enhancement of mutagenic activity in Salmonella typhimurium strain TA98 and the Ames II mixed strains (TA7001-7006) was observed in urine samples from animals implanted with depleted uranium pellets. In contrast, urine samples from animals implanted with tantalum did not show a significant enhancement of mutagenic activity in these strains. In depleted uranium-implanted animals, urine mutagenicity increased in a dose- and time-dependent manner demonstrating a strong positive correlation with urine uranium levels (r = 0.995, P < 0.001). There was no mutagenic enhancement of any bacterial strain detected in the sera of animals implanted with either depleted uranium or tantalum pellets. The results suggest that uranium content in the urine is correlated with urine mutagenicity and that urinary mutagenicity might be used as a biomarker to detect exposure to internalized uranium.

Microbiology of healthy and diseased adenoids

OBJECTIVE

To determine the qualitative and quantitative microbiology of core adenoid tissue obtained from four groups of 15 children each, with recurrent otitis media (ROM), recurrent adenotonsillitis (RAT), obstructive adenoid hypertrophy (OAH), and occlusion or speech abnormalities (controls).

METHODS

Core cultures of surgically removed diseased adenoids and of healthy controls were cultured for aerobic and anaerobic bacteria.

RESULTS

Polymicrobial aerobic-anaerobic flora were present in all instances. Ninety-four organisms were isolated from control specimens, and 148 from ROM, 142 from RAT, and 149 from OAH specimens. The predominant aerobes in all groups were alpha-hemolytic and gamma-hemolytic streptococci, Haemophilus influenzae, Staphylococcus aureus, group A beta-hemolytic streptococci, and Moraxella catarrhalis. The prominent anaerobes were Peptostreptococcus, Prevotella, and Fusobacterium species. The number, concentration and distribution of types of most organisms did not vary among the three groups of diseased adenoids. However, the number of those that are potential pathogens and those that produced beta-lactamase was lower in the control than the diseased adenoids (P < .001).

CONCLUSION

The study highlights the importance of the bacterial load in the adenoids in contributing to the etiology of ROM, RAT, and OAH.

Factors influencing the onset and progression of diabetic retinopathy in subjects with insulin-dependent diabetes mellitus

BACKGROUND

The etiology of diabetic retinopathy is poorly understood. In the current study, factor associated with the onset and the progression or regression of retinopathy are evaluated.

METHODS

Two hundred seventy-seven subjects with insulin-dependent (type I) diabetes mellitus (IDDM) were evaluated longitudinally for retinal changes over a mean of 2.7 years. The multistate Markov model was used to analyze the influences of the duration of diabetes, a family history of hypertension, age, sex, cigarette smoking, systolic blood pressure, diastolic blood pressure, cholesterol levels, and longitudinal glycohemoglobin (GHb) values on the development and the progression or regression of retinopathy.

RESULTS

Univariate analysis confirmed that four factors were significantly associated with the etiology and the progression or regression of diabetic retinopathy: age, duration of diabetes, mean longitudinal GHb levels (all at P < 0.01), and diastolic blood pressure (P < 0.04). However, age was no longer significant when controlled by duration of diabetes. Cigarette smoking was only associated significantly with background retinopathy (stages 2 and 3). Systolic blood pressure, sex, a family history of hypertension, and cholesterol levels were not significantly associated with retinopathy.

CONCLUSIONS

The onset of diabetic retinopathy is associated with the duration of diabetes, mean longitudinal GHb levels, smoking, and diastolic blood pressure. A longer duration of diabetes, higher GHb values, and higher diastolic blood pressure levels are associated with an increased risk of progression and a decreased chance of regression of diabetic retinopathy.

Acquired adult flat foot due to isolated plantar calcaneonavicular (spring) ligament insufficiency with a normal tibialis posterior tendon

BACKGROUND

We present nine cases of acquired flat foot deformity (AFFD) in adults caused by isolated spring ligament insufficiency.

METHODS

We present the clinical sign that allows differentiation of this diagnosis from posterior tibialis tendon (PTT) dysfunction namely the ability to single leg tiptoe, but with persistent forefoot abduction and heel valgus. In addition we illustrate the unique radiological features which allow confirmation of the diagnosis. Only a solitary previous case report has documented this alternative aetiology of AFFD; in that case, diagnosis was made intra-operatively.

RESULTS

Six patients have been managed with orthoses. Three patients underwent surgery; one patient who presented early had isolated repair of the spring ligament complex. The remaining two required a calcaneal osteotomy and flexor digitorum longus transfer as for a PTT reconstruction.

CONCLUSION

We propose that early diagnosis (with ultrasound confirmation) and management of this condition would offer a better prognosis and allow less interventional surgery.

High-Temperature XAS Study of Fe 2 SiO 4 Liquid: Reduced Coordination of Ferrous Iron

X-ray absorption spectroscopy (XAS) of Fe(2+) in Fe(2)SiO(4) liquid at 1575 kelvin and 10(-4) gigapascal (1 bar) shows that the Fe(2+) -O bond length is 1.98 +/- 0.02 angstroms compared with approximately 2.22 angstroms in crystalline Fe(2)SiO(4) (fayalite) at the melting point (1478 kelvin), which indicates a decrease in average Fe(2+) coordination number from six in fayalite to four in the liquid. Anharmonicity in the liquid was accounted for using a data analysis procedure. This reduction in coordination number is similar to that observed on the melting of certain ionic salts. These results are used to develop a model of the medium-range structural environment of Fe(2+) in olivine-composition melts, which helps explain some of the properties of Fe(2)SiO(4) liquid, including density, viscosity, and the partitioning of iron and nickel between silicate melts and crystalline olivines. Some of the implications of this model for silicate melts in the Earth's crust and mantle are discussed.

The delayed pulmonary syndrome following acute high-dose irradiation: a rhesus macaque model

Several radiation dose- and time-dependent tissue sequelae develop following acute high-dose radiation exposure. One of the recognized delayed effects of such exposures is lung injury, characterized by respiratory failure as a result of pneumonitis that may subsequently develop into lung fibrosis. Since this pulmonary subsyndrome may be associated with high morbidity and mortality, comprehensive treatment following high-dose irradiation will ideally include treatments that mitigate both the acute hematologic and gastrointestinal subsyndromes as well as the delayed pulmonary syndrome. Currently, there are no drugs approved by the Food and Drug Administration to counteract the effects of acute radiation exposure. Moreover, there are no relevant large animal models of radiation-induced lung injury that permit efficacy testing of new generation medical countermeasures in combination with medical management protocols under the FDA animal rule criteria. Herein is described a nonhuman primate model of delayed lung injury resulting from whole thorax lung irradiation. Rhesus macaques were exposed to 6 MV photon radiation over a dose range of 9.0-12.0 Gy and medical management administered according to a standardized treatment protocol. The primary endpoint was all-cause mortality at 180 d. A comparative multiparameter analysis is provided, focusing on the lethal dose response relationship characterized by a lethal dose50/180 of 10.27 Gy [9.88, 10.66] and slope of 1.112 probits per linear dose. Latency, incidence, and severity of lung injury were evaluated through clinical and radiographic parameters including respiratory rate, saturation of peripheral oxygen, corticosteroid requirements, and serial computed tomography. Gross anatomical and histological analyses were performed to assess radiation-induced injury. The model defines the dose response relationship and time course of the delayed pulmonary sequelae and consequent morbidity and mortality. Therefore, it may provide an effective platform for the efficacy testing of candidate medical countermeasures against the delayed pulmonary syndrome.

Benefits of early tracheostomy in severely burned children

OBJECTIVE

The role of tracheostomy in burn patients is controversial. Previous studies, primarily in adults, suggested that severely burned patients with tracheostomies have a higher incidence of tracheostomy site infections, mortality, and pneumonia. The purpose of this study is to determine the safety and efficacy of early tracheostomy in severely burned children.

DESIGN

Case series study analyzing mechanical ventilation and sedation requirements before and 24 hrs after tracheostomy.

SETTING

Regional pediatric burn center.

PATIENTS

All children admitted to a regional pediatric burn center requiring tracheostomy from March 1, 1998, to October 1, 2001.

METHODS

Data were recorded on patients' demographics, extent of burn, presence of inhalation injury, and mortality. Mechanical ventilation variables measured pretracheostomy (pre) and posttracheostomy (post) and included mode of ventilation, ventilator settings, peak inspiratory pressures, and arterial blood gases (Pao2, Paco2, pH, and oxygen saturation). Calculated variables included compliance, Pao2:Fio2 ratio, and minute ventilation. Tracheostomy-related variables recorded included the interval to tracheostomy insertion, the duration of tracheostomy, and tracheostomy complications.

MAIN RESULTS

A total of 38 patients (with a mean age of 4.7 +/- 0.6 yrs and a mean total body surface area involvement of 54% +/- 4%, 63% with inhalation injury) underwent tracheostomy a mean of 3.9 +/- 0.7 days after admission. Overall mortality was 21%. There were no tracheostomy site infections, tracheostomy-related deaths, or tracheal stenoses in survivors. Peak inspiratory pressures were lower after tracheostomy (30.4 +/- 1.4 [pre] vs. 27.6 +/- 1.5 cm H2O [post]; p <.05), ventilatory volumes were higher (190 +/- 22 mL [pre] vs. 225.5 +/- 25 [post]; p <.05), compliance improved (10.5 +/- 1.4 [pre] vs. 15.1 +/- 2.3 mL/cm H2O [post]; p <.05), and the Pao2:Fio2 ratio improved (300.6 +/- 20 [pre] vs. 348.6 +/- 16 [post]). There was no difference in oxygenation, ventilation, minute ventilation, or pH after tracheostomy.

CONCLUSIONS

Early tracheostomy in severely burned children is safe and effective. It provides a secure airway and may result in improvement in ventilator management for these children.

Varicella-zoster virus glycoprotein gpI/gpIV receptor: expression, complex formation, and antigenicity within the vaccinia virus-T7 RNA polymerase transfection system

The unique short region of the varicella-zoster virus (VZV) genome contains two open reading frames which encode glycoproteins designated gpI and gpIV (herpes simplex virus homologs gE and gI, respectively). Like its herpesviral counterpart gE, the VZV gpI gene product functions as a cell surface receptor (V. Litwin, W. Jackson, and C. Grose, J. Virol. 66:3643-3651, 1992). To evaluate the biosynthesis of the two VZV glycoproteins and further explore their relationship to one another, the two glycoprotein genes were individually cloned into a pTM1 vector under control of the T7 promoter. Transfection of the cloned gpI or gpIV construct into HeLa cells previously infected with vaccinia recombinant virus expressing bacteriophage T7 polymerase resulted in a much higher level expression of each VZV glycoprotein than previously achieved. Synthesis of both gpI and gpIV included intermediary partially glycosylated forms and mature N- and O-linked final product. Transfections in the presence of 32Pi demonstrated that the mature forms of both gpI and gpIV were phosphorylated, while similar experiments with [35S]sulfate showed that only the mature gpI was sulfated. When gpI and gpIV were coexpressed in the same cell, the two glycoproteins were complexed to each other, as both proteins could be immunoprecipitated by antibodies against either gpI or gpIV. Coprecipitation did not occur as a result of a shared epitope, because gpI expressed alone was not precipitated by antibody to gpIV, and gpIV expressed alone was not precipitated by antibody to gpI. Pulse-chase analysis demonstrated that the gpI-gpIV association occurred early in processing; furthermore, this complex formation interfered with posttranslational modifications and thereby reduced the M(r)s of the mature forms of both gpI and gpIV. Similarly, the molecular masses of the cotransfected gene products corresponded with those of the infected cell glycoproteins, a result which suggested that authentic gpI and gpIV were ordinarily found within a complex. Thus, the adjacent open reading frames 67 and 68 code for two glycoproteins which in turn form a distinctive sulfated and phosphorylated cell surface complex with receptor properties.

The Hematopoietic Syndrome of the Acute Radiation Syndrome in Rhesus Macaques: A Systematic Review of the Lethal Dose Response Relationship

Well characterized animal models that mimic the human response to potentially lethal doses of radiation are required to assess the efficacy of medical countermeasures under the criteria of the U.S. Food and Drug Administration "animal rule." Development of a model requires the determination of the radiation dose response relationship and time course of mortality and morbidity across the hematopoietic acute radiation syndrome. The nonhuman primate, rhesus macaque, is a relevant animal model that may be used to determine the efficacy of medical countermeasures to mitigate major signs of morbidity and mortality at selected lethal doses of total body irradiation. A systematic review of relevant studies that determined the dose response relationship for the hematopoietic acute radiation syndrome in the rhesus macaque relative to radiation quality, dose rate, and exposure uniformity has never been performed. The selection of data cohorts was made from the following sources: Ovid Medline (1957-present), PubMed (1954-present), AGRICOLA (1976-present), Web of Science (1954-present), and U.S. HHS REPORT (2002 to present). The following terms were used: Rhesus, total body-irradiation, total body x irradiation, TBI, irradiation, gamma radiation, hematopoiesis, LD50/60, Macaca mulatta, whole-body irradiation, nonhuman primate, NHP, monkey, primates, hematopoietic radiation syndrome, mortality, and nuclear radiation. The reference lists of all studies, published and unpublished, were reviewed for additional studies. The total number of hits across all search sites was 3,001. There were a number of referenced, unpublished, non-peer reviewed government reports that were unavailable for review. Fifteen studies, 11 primary (n = 863) and four secondary (n = 153) studies [n = 1,016 total nonhuman primates (NHP), rhesus Macaca mulatta] were evaluated to provide an informative and consistent review. The dose response relationships (DRRs) were determined for uniform or non-uniform total body irradiation (TBI) with 250 kVp or 2 MeV x radiation, Co gamma radiation and reactor- and nuclear weapon-derived mixed gamma: neutron-radiation, delivered at various dose rates from a total body, bilateral, rotational, or unilateral exposure aspect. The DRRs established by a probit analysis vs. linear dose relationship were characterized by two main parameters or dependent variables: a slope and LD50/30. Respective LD50/30 values for studies that used 250 kVp x radiation (five primary studies combined, n = 338), 2 MeV x radiation, Co gamma radiation, and steady-state reactor-derived mixed gamma:neutron radiation for total body uniform exposures were 521 rad [498, 542], 671 rad [632, 715], 644 rad [613, 678], and 385 rad [357, 413]. The respective slopes were steep and ranged from 0.738 to 1.316. The DRR, LD50/30 values and slopes were also determined for total body, non-uniform, unilateral, pulse-rate exposures of mixed gamma:neutron radiation derived at reactor and nuclear weapon detonations. The LD50/30 values were, respectively, 395 rad [337, 432] and 412 rad [359, 460]. Secondary data sets of limited studies that did not describe a DRR were used to support the mid-to-high lethal dose range for the H-ARS and the threshold dose range for the concurrent acute GI ARS. The available evidence provided a reliable and extensive database that characterized the DRR for the H-ARS in young rhesus macaques exposed to 250 kVp uniform total body x radiation without the benefit of medical management. A less substantial but consistent database demonstrated the DRR for total body exposure of differing radiation quality, dose rate and non-uniform exposure. The DRR for the H-ARS is characterized by steep slopes and relative LD50/30 values that reflect the radiation quality, exposure aspect, and dose rate over a range in time from 1954-2012.

Rehabilitation versus surgical reconstruction for non-acute anterior cruciate ligament injury (ACL SNNAP): a pragmatic randomised controlled trial

BACKGROUND

Anterior cruciate ligament (ACL) rupture is a common debilitating injury that can cause instability of the knee. We aimed to investigate the best management strategy between reconstructive surgery and non-surgical treatment for patients with a non-acute ACL injury and persistent symptoms of instability.

METHODS

We did a pragmatic, multicentre, superiority, randomised controlled trial in 29 secondary care National Health Service orthopaedic units in the UK. Patients with symptomatic knee problems (instability) consistent with an ACL injury were eligible. We excluded patients with meniscal pathology with characteristics that indicate immediate surgery. Patients were randomly assigned (1:1) by computer to either surgery (reconstruction) or rehabilitation (physiotherapy but with subsequent reconstruction permitted if instability persisted after treatment), stratified by site and baseline Knee Injury and Osteoarthritis Outcome Score-4 domain version (KOOS4). This management design represented normal practice. The primary outcome was KOOS4 at 18 months after randomisation. The principal analyses were intention-to-treat based, with KOOS4 results analysed using linear regression. This trial is registered with ISRCTN, ISRCTN10110685, and ClinicalTrials.gov, NCT02980367.

FINDINGS

Between Feb 1, 2017, and April 12, 2020, we recruited 316 patients. 156 (49%) participants were randomly assigned to the surgical reconstruction group and 160 (51%) to the rehabilitation group. Mean KOOS4 at 18 months was 73·0 (SD 18·3) in the surgical group and 64·6 (21·6) in the rehabilitation group. The adjusted mean difference was 7·9 (95% CI 2·5-13·2; p=0·0053) in favour of surgical management. 65 (41%) of 160 patients allocated to rehabilitation underwent subsequent surgery according to protocol within 18 months. 43 (28%) of 156 patients allocated to surgery did not receive their allocated treatment. We found no differences between groups in the proportion of intervention-related complications.

INTERPRETATION

Surgical reconstruction as a management strategy for patients with non-acute ACL injury with persistent symptoms of instability was clinically superior and more cost-effective in comparison with rehabilitation management.

FUNDING

The UK National Institute for Health Research Health Technology Assessment Programme.

Blood pressure and retinopathy in type I diabetes

The relationship between blood pressure and diabetic retinopathy was evaluated in 249 young subjects with type I diabetes. Although hypertension is known to be associated with an increased risk for retinopathy, the effects of high-normal blood pressure are unknown. Retinopathy (158 of 249 subjects, 63%) is considerably more common in a young diabetic population than is hypertension (7 of 249 subjects, 2%). Thus, if blood pressure is important in the etiology or progression of diabetic retinopathy, levels below the hypertensive range (less than 141/90 mmHg) must be considered. The combined effect of hypertension and high-normal blood pressure (greater than 90th percentile but less than 141/90 mmHg) was studied. Elevation in diastolic blood pressure, alone, and in combination with elevated systolic blood pressure, correlated significantly (P less than 0.03) with retinopathy. The presence of high-normal blood pressure resulted in a prospectively higher occurrence of retinopathy and of progression of preexisting retinopathy. Glycohemoglobin (HbA1) and duration of diabetes also correlated with retinopathy. Both good glycemic control and maintenance of diastolic blood pressure below the 90th percentile for age may be important in relation to diabetic retinopathy.