NrCAM-deficient mice exposed to chronic stress exhibit disrupted latent inhibition, a hallmark of schizophrenia

The neuronal cell adhesion molecule (NrCAM) is widely expressed and has important physiological functions in the nervous system across the lifespan, from axonal growth and guidance to spine and synaptic pruning, to organization of proteins at the nodes of Ranvier. NrCAM lies at the core of a functional protein network where multiple targets (including NrCAM itself) have been associated with schizophrenia. Here we investigated the effects of chronic unpredictable stress on latent inhibition, a measure of selective attention and learning which shows alterations in schizophrenia, in NrCAM knockout (KO) mice and their wild-type littermate controls (WT). Under baseline experimental conditions both NrCAM KO and WT mice expressed robust latent inhibition (p = 0.001). However, following chronic unpredictable stress, WT mice (p = 0.002), but not NrCAM KO mice (F < 1), expressed latent inhibition. Analyses of neuronal activation (c-Fos positive counts) in key brain regions relevant to latent inhibition indicated four types of effects: a single hit by genotype in IL cortex (p = 0.0001), a single hit by stress in Acb-shell (p = 0.031), a dual hit stress x genotype in mOFC (p = 0.008), vOFC (p = 0.020), and Acb-core (p = 0.032), and no effect in PrL cortex (p > 0.141). These results indicating a pattern of differential effects of genotype and stress support a complex stress × genotype interaction model and a role for NrCAM in stress-induced pathological behaviors relevant to schizophrenia and other psychiatric disorders.

Assessment of COVID-19 outbreaks in long-term care facilities

BACKGROUND

The B.1.167.2 (Delta) variant quickly became the predominant circulating SARS-CoV-2 strain in the USA during summer 2021. Missouri identified a high number of outbreaks in long-term care facilities (LTCFs) across the state with low vaccination rates among LTCF staff members and poor adherence to mitigation measures within local communities.

AIM

To describe COVID-19 outbreaks that occurred in Missouri LTCFs impacting staff and residents during the surge of the Delta variant.

METHODS

Outbreaks of COVID-19 in 178 LTCFs were identified by the Missouri Department of Health and Senior Services. Case data from LTCFs with the highest burden of disease were analysed to assess disease transmission, vaccination status, and outcomes among residents and staff. Additional investigational measures included onsite visits to facilities with recent COVID-19 outbreaks in communities with substantial transmission to assess mitigation measures.

FINDINGS

During April 22^nd to July 29^th, 2021, 159 COVID-19 cases among 72 staff members and 87 residents were identified in 10 LTCFs. More than 74.7% of resident cases were vaccinated compared to 23.6% of staff cases. Vaccinated residents had a lower proportion of hospitalizations and deaths reported compared to unvaccinated residents. Data analysis and contact-tracing efforts from a sample of the facilities suggest that staff members were likely a major factor in introducing SARS-CoV-2 virus into the facilities. Adherence to COVID-19 mitigation measures varied at the visited facilities.

CONCLUSION

Data showed that vaccination rates varied between staff cases and resident cases in facilities with high-burden outbreaks. Differences were identified in mitigation practices in at least two facilities.

Realigning the conventional routes of transmission: an improved model for occupational exposure assessment and infection prevention

Current recommendations for standard and transmission-based precautions in place for patients who are suspected or known to be infected or colonized with infectious agents are best suited to prevent the transfer of micro-organisms to other patients - that is, to prevent the acquisition of a healthcare-associated infection, rather than to protect the healthcare worker from self-contamination resulting in a potential occupationally acquired infection. This article reviews current recommended infection prevention and control practices and offers a framework for better protection and controls from an occupational health point of view. We offer a model with two exposure routes - contact and aerosol - resulting from work activities and environments, shifting the focus away from particular pathogenic micro-organisms' typical methods for spreading to patients or to other non-workers in hospital and community settings.

Impaired Latent Inhibition in GDNF-Deficient Mice Exposed to Chronic Stress

Increased reactivity to stress is maladaptive and linked to abnormal behaviors and psychopathology. Chronic unpredictable stress (CUS) alters catecholaminergic neurotransmission and remodels neuronal circuits involved in learning, attention and decision making. Glial-derived neurotrophic factor (GDNF) is essential for the physiology and survival of dopaminergic neurons in substantia nigra and of noradrenergic neurons in the locus coeruleus. Up-regulation of GDNF expression during stress is linked to resilience; on the other hand, the inability to up-regulate GDNF in response to stress, as a result of either genetic or epigenetic modifications, induces behavioral alterations. For example, GDNF-deficient mice exposed to chronic stress exhibit alterations of executive function, such as increased temporal discounting. Here we investigated the effects of CUS on latent inhibition (LI), a measure of selective attention and learning, in GDNF-heterozygous (HET) mice and their wild-type (WT) littermate controls. No differences in LI were found between GDNF HET and WT mice under baseline experimental conditions. However, following CUS, GDNF-deficient mice failed to express LI. Moreover, stressed GDNF-HET mice, but not their WT controls, showed decreased neuronal activation (number of c-Fos positive neurons) in the nucleus accumbens shell and increased activation in the nucleus accumbens core, both key regions in the expression of LI. Our results add LI to the list of behaviors affected by chronic stress and support a role for GDNF deficits in stress-induced pathological behaviors relevant to schizophrenia and other psychiatric disorders.

Childhood Guillain-Barré syndrome: clinical and electrophysiologic features predictive of outcome

The hospital records of 27 children with the diagnosis of Guillain-Barré syndrome were retrospectively reviewed. Based on the time to recovery, patients were divided into two groups: group 1 consisted of children whose times to complete or partial recovery extended beyond 2 months from onset of the disease; group 2 consisted of children who attained a full recovery within 2 months from onset of the disease. The clinical and electrophysiologic features of the two groups were statistically compared for their predictive value of outcome. Three clinical features (maximum disability score at presentation, intubation, and cranial nerve involvement) were predictive of poor outcome, whereas one electrophysiologic feature (conduction block) was predictive of favorable outcome. There was also a significant correlation between maximum disability score at presentation and the probability of intubation.

Targeted therapy for malignant melanoma

There has been much development in the field of targeted therapy for melanoma stemming from efforts to decrease treatment-related toxicities and enhance specific cytotoxicity. This review focuses on three modalities of targeted melanoma therapy based on the biology of the targeting mechanism. The first of these modalities is immunotherapy, which functions to generate a specific antimelanoma immunity. A second modality utilizes metabolic pathways of melanin synthesis to target melanoma cells specifically. A third modality ensues from recent advances in molecular biology and the identification of genes responsible for the malignant transformation of normal melanocytes to melanomas. This work has furthered our understanding of the basis of malignancy, as well as the development of novel strategies aimed at targeting aberrant growth in melanoma.

Microcirculation patterns other than loops and networks in choroidal and ciliary body melanomas

PURPOSE

To provide ophthalmologists and pathologists with expanded criteria for separating patients at high risk of metastatic melanoma from those at low risk on the basis of microcirculation patterns in choroidal and ciliary body melanomas.

DESIGN

Tissue culture studies and observational case series.

PARTICIPANTS

The pattern-forming ability of four uveal melanoma cell lines of varying degrees of aggressive behavior was studied in vitro. Histologic sections of 234 eyes removed for choroidal or ciliary body melanoma were studied for the presence of microcirculation patterns.

METHODS

The study was divided into two phases: the study of histologic sections of eyes removed for choroidal and ciliary body melanomas and observations on the in vitro behavior of cultured melanoma cells of varying degrees of invasive behavior. The presence or absence of each of nine microcirculation patterns was recorded from tissue sections, and interrelationships between different patterns were explored statistically. In vitro reconstitution of patterns and a study of the interrelationships of patterns in histologic sections was carried out. In the in vitro studies, uveal melanoma cell lines of varying degrees of aggressive potential were cultured to observe the development of architectural patterns other than loops and networks.

MAIN OUTCOME MEASURES

In histologic studies, the outcome measure was the conditional probability of detecting loops or networks given the presence or absence of other patterns positive for periodic acid-SCHIFF: For tissue culture studies, the outcome measure was either the development or lack of development of patterns of different shapes in vitro.

RESULTS

Histologic studies disclosed that given the presence of arcs without or with branching in a tissue section, it is likely that loops or networks will be detected in the same section plane, suggesting that the production of these patterns by aggressive tumor cells reflects a spectrum of architectural potential. In vitro studies confirmed this hypothesis by revealing that highly aggressive and metastatic uveal melanoma cell lines, but not poorly aggressive tumor cell lines, generated parallel channels with and without crosslinking and arcs with and without branching as well as loops and networks.

CONCLUSIONS

The criteria for separating patients into low- and high-risk categories for metastasis from uveal melanoma should be expanded to include patterns other than loops or networks. In both the pathology laboratory as well as in a clinical setting, the detection of arcs or arcs with branching and parallel channels should prompt a careful search for loops and networks and for crosslinking parallel channels, respectively.

Structure of neurolysin reveals a deep channel that limits substrate access

The zinc metallopeptidase neurolysin is shown by x-ray crystallography to have large structural elements erected over the active site region that allow substrate access only through a deep narrow channel. This architecture accounts for specialization of this neuropeptidase to small bioactive peptide substrates without bulky secondary and tertiary structures. In addition, modeling studies indicate that the length of a substrate N-terminal to the site of hydrolysis is restricted to approximately 10 residues by the limited size of the active site cavity. Some structural elements of neurolysin, including a five-stranded beta-sheet and the two active site helices, are conserved with other metallopeptidases. The connecting loop regions of these elements, however, are much extended in neurolysin, and they, together with other open coil elements, line the active site cavity. These potentially flexible elements may account for the ability of the enzyme to cleave a variety of sequences.

Factors affecting injury severity to rear-seated occupants in rural motor vehicle crashes

Injury to rear-seat occupants (RSOs) has received little systematic study in the literature. Past studies have focused on patterns of injury presented to the emergency department, various aspects of restraint usage and injury, or specific populations of RSOs. This is the first systematic analysis of injury severity to RSOs. RSOs involved in motor vehicle crashes (MVCs) sustain injuries of equal severity as do front-seated occupants (FSOs) involved in the same crash. The setting was a rural North Carolina emergency department where patients were evaluated at the sole hospital for the county. The design was a 2-year retrospective review of all MVCs with RSOs occurring in Pitt County North Carolina in calendar years 1988 and 1989. The Wilcoxon Rank-Sum Test and Logistic Regression Analysis with Injury Severity Score (ISS) as the dependent variable were performed. Three hundred forty-six crashes involving 367 vehicles with RSOs and 1,273 occupants that sent 222 patients to the hospital. ISS was higher for unrestrained occupants (1.87 versus 0.51), occupants of vehicles driven by legally intoxicated drivers (4.04 versus 0.73), occupants between the ages of 30 and 59 years (1.06 versus 0.65) and FSOs (1.04 versus 0.85) (Wilcoxon Rank-Sum test P <.0002). Logistic regression analysis confirmed these findings with the exception of more severe injuries for the 30 to 59 age range and impact speed. The analysis failed in these 2 cases. Restraint usage offered the greatest protective effect (OR 0.37). Lesser protective effects were noted with rear seat occupancy (OR 0.43) and age < 13 years (OR 0.77). More severe injuries were predicted by driver intoxication (OR 2.5), and age > 60 years (OR 1.25). In our rural population, RSOs sustain less severe injuries than FSOs. Restraint usage and sober drivers provide a greater protective effect however. Seat location does not replace restraint usage or sobriety.

Validation of partial tissue segmentation of single-channel magnetic resonance images of the brain

We describe and evaluate a practical, automated algorithm based on local statistical mixture modeling for segmenting single-channel, T1-weighted volumetric magnetic resonance images of the brain into gray matter, white matter, and cerebrospinal fluid. We employed a stereological sampling method to assess, prospectively, the performance of the method with respect to human experts on 10 normal T1-weighted brain scans acquired with a three-dimensional gradient echo pulse sequence. The overall kappa statistic for the concordance of the algorithm with the human experts was 0.806, while that among raters, excluding the algorithm, was 0.802. The algorithm had better agreement with the modal expert decision (kappa = 0.878). The algorithm could not be distinguished from the experts by this measure. We also validated the algorithm on a simulated MR scan of a digital brain phantom with known tissue composition. Global gray matter and white matter errors were 1% and <1%, respectively, and correlation coefficients with the underlying tissue model were 0.95 for gray matter, 0.98 for white matter, and 0.95 for cerebrospinal fluid. In both approaches to validation, we evaluated both local and global performance of the algorithm. Human experts generated slightly higher global gray matter proportion estimates on the test brain scans relative to the algorithm (3.7%) and on the simulated MR scan relative to the true tissue model (4.4%). The algorithm underestimated gray in some subcortical nuclei which contain admixed gray and white matter. We demonstrate the reliability of the method on individual 1 NEX data sets of the test subjects, and its insensitivity to the precise values of initial model parameters. The output of this algorithm is suitable for quantifying cerebral cortical tissue, using a commonly performed commercial pulse sequence.

A novel approach for the identification of unique tumor vasculature binding peptides using an E. coli peptide display library

BACKGROUND

Tumor neovascularization is necessary for continued tumor growth and metastasis. During the process of endothelial cell (EC) recruitment and tumor infiltration, specific molecular markers unique for this interaction are expressed on the EC surface. Targeting these molecular markers would, in effect, allow for specific tumor targeting. Tripeptide sequence motifs have previously been reported that will bind to angiogenic tumor ECs. These sequences were identified from in vivo phage peptide display libraries. The purpose of this study was to use a more simplified bacterial peptide display library in an in vitro system to seek out peptide motifs with unique binding to tumor microvasculature.

METHODS

FliTrx is a bacterial peptide display library containing the entire repertoire of possible random dodecapeptides expressed on the flagella tip of E. coli. Two EC populations were used for the screening process, Matrigel invading cells (MAGIC) and tumor-derived endothelial cells (TDEC). MAGIC are obtained from ECs that infiltrate a subcutaneous fibroblast growth factor-containing Matrigel deposit, and TDEC are ECs selectively obtained from tumor vasculature. FliTrx cells were incubated with MAGIC at 4 degrees C to remove any potential clones displaying peptides that will bind to nonspecific EC surface targets. The non-binding cells were then incubated with TDEC, allowing for clones displaying potential binding peptides to bind tumor specific targets on TDECs. The bacterial population was then expanded and this "panning" process was carried out a total of five times. Peptide insert sequences from 100 bacterial colonies were analyzed for potential repetitive peptide motifs.

RESULTS

Recurring peptide sequences were detected that were 3-mers (13 sequences) and 4-mers (4 sequences). Of the 3-mers, four repeated 3 times, whereas none of the 4-mers repeated more than twice. All of the repeated sequences were basic in charge, and arginine was the most commonly seen amino acid. A tripeptide basic-basic-nonpolar amino acid arrangement was the most prevalent charge sequence in all repetitive motifs (17 repeat sequences). Two test peptides showed TDEC binding specificity, and both conformed to the basic-basic-nonpolar motif.

CONCLUSIONS

We report peptide sequences derived from panning an in vitro system designed to detect tumor-EC specific markers. These putative motifs may serve as molecular determinants for a novel therapeutic modality aimed at specifically targeting tumors through tumor angiogenic vessels.

Crystallization and preliminary analysis of neurolysin

Neuropeptidases inactivate or modify the activity of peptide neurotransmitters and neurohormones. The neuropeptidase neurolysin acts only on short peptides and accepts a variety of cleavage-site sequences. Structures of the enzyme and enzyme-substrate complexes will help to determine the mechanisms of substrate selectivity used by this enzyme. Crystals of recombinant neurolysin have been grown in the orthorhombic space group P2(1)2(1)2, with unit-cell parameters a = 157.8, b = 88.0, c = 58.4 A. Data have been collected to 2.3 A at 110 K with observed diffraction to 1.8 A. Circular dichroism measurements suggest that the enzyme is primarily alpha-helical, with little beta-strand secondary structure. Sequence-based secondary-structure prediction supports this conclusion.

Using the essential services as a foundation for performance measurement and assessment of local public health systems

Efforts are under way to develop a performance measurement monitoring system for state and local public health systems and to develop a strategic planning tool for local public health systems. The development of these measures is being based on the Essential Public Health Services. This article provides the rationale for why the Essential Services offer a good framework for identifying, analyzing, and evaluating public health activities. The article also reviews the history of local public health and the development and application of the Essential Public Health Services and their predecessor frameworks such as the core functions, the organizational practices, and the essential elements.

Diagnostic evaluation of patients with blunt abdominal trauma: a decision analysis

OBJECTIVES

Using decision analysis, to compare the expected utility (EU) of diagnostic peritoneal lavage (DPL), computed tomography (CT), and ultrasonography (US) to determine the optimal modality for the evaluation of blunt abdominal trauma (BAT) in hemodynamically stable adults.

METHODS

Data points for the decision analysis were obtained from three sources: 1) prevalence of BAT and the sensitivity and specificity of each diagnostic modality were determined through a criteria-based review of the literature; 2) rate of BAT necessitating immediate intervention, perioperative complication rate, and operative mortality rate were calculated using data from the authors' institution's trauma registry; and 3) outcome utilities were determined by telephone survey of adults in a random sample of households in the region. The decision tree was constructed and evaluated in standard fashion. For each diagnostic modality, the authors calculated the EU using the minimum, mean, and maximum sensitivity and specificity across a range of prevalence. Mean outcome utilities were used for each branch of the tree when calculating the EU.

RESULTS

The EU of CT was consistently lower than the EUs of DPL and US at all levels of prevalence. However, the rank order of the EUs of US and DPL varied with the prevalence of BAT. When the prevalence was <30%, the EU of US was higher than that for DPL. When the prevalence was 30-40%, the EUs were similar. When the prevalence was >40%, the EU of US was less than that of DPL.

CONCLUSIONS

Among institutions operating under constraints similar to those used in this model, the optimal diagnostic modality for the evaluation of BAT can be determined based on the sensitivity and specificity of the modality at their institution and the prevalence of BAT in their patient population.

Late effects in children treated with radiation therapy for Wilms' tumor

PURPOSE

To determine the frequency and types of late effects in children receiving radiation therapy (RT) for Wilms' tumor.

MATERIALS AND METHODS

From 1968 to 1994, 55 children received megavoltage RT at our institution as part of treatment for Wilms' tumor. A total of 42 (76.4%) have survived and have a minimum follow-up of 5 years. There were 25 female and 17 male patients with a median age at diagnosis of 48 months (range, 7-126 months). There were 12 Stage I, eight Stage II, 15 Stage III, six Stage IV, and one Stage V patient. RT was delivered to the hemiabdomen in 36 and whole abdomen in six patients. RT dose was 1000-1200 cGy (Group A) in 12, 1201-2399 cGy (Group B) in 11, and 2400-4000 cGy (Group C) in 19. Whole-lung RT was delivered to 13 patients either at diagnosis or pulmonary relapse. All patients received chemotherapy; the most common agents were actinomycin-D/vincristine/adriamycin in 13 and actinomycin-D/vincristine in 18. Median follow-up was 181 months (range, 60-306 months).

RESULTS

Of 42 patients, 13 (31.0%) did not have late effects of treatment. The number of patients who developed muscular hypoplasia, limb length inequality, kyphosis, and iliac wing hypoplasia were seven (16.7%), five (11.9%), three (7.1%), and three (7.1%), respectively. Scoliosis was seen in 18 (42.9%) with only one patient requiring orthopedic intervention. Median time to development of scoliosis was 102 months, with a range of 16-146 months. The actuarial incidence of scoliosis at 5, 10, and 15 years after RT was 4.8 +/- 3.3%, 51.8 +/- 9.0%, and 56.7 +/- 9.3%, respectively. Only one of 12 Group A patients developed scoliosis. The 10- and 15-year actuarial incidences of scoliosis for Group A and B patients were 37.7 +/- 12.4% and 37.7 +/- 12.4%, whereas for Group C patients the incidences were 65.8 +/- 12.0% and 74.4 +/- 11. 7% (p = 0.03, log rank test). The actuarial incidence of bowel obstruction at 5, 10, and 15 years was 9.5 +/- 4.5%, 13.0 +/- 5.6%, and 17.0 +/- 6.5%. Of 23 patients, five irradiated within 10 days of surgery and one of 19 irradiated after 10 days developed bowel obstruction (p = 0.09, log rank test). Three patients developed hypertension with normal blood urea nitrogen (BUN) and creatinine levels; another patient had chronic renal insufficiency in a nonirradiated kidney. One patient developed diffuse interstitial pneumonitis. Of the 19 female patients who have reached puberty, three have given birth, and 15 have regular and one has irregular menstrual periods. Four patients developed benign neoplasms; three were in the RT field (two osteochondroma, one lipoma) and one outside (cervical intraepithelial neoplasia II). There were three second malignancies (chronic myelogenous leukemia at 9 years, osteosarcoma at 11 years, and breast cancer at 25 years after initial diagnosis of nephroblastoma); both solid malignancies occurred in the RT field.

CONCLUSIONS

Late effects of therapy were seen in more than two thirds of children treated for Wilms' tumor. Children treated with lower doses (<2400 cGy) had a lower incidence of scoliosis compared with those who received more than 2400 cGy. There is also a suggestion that the incidence is lower in patients who received 1000-1200 cGy. Severe physical and functional deformity from RT was uncommon.

Auditory evoked responses and learning and awareness during general anesthesia

BACKGROUND

There is a major distinction between conscious and unconscious learning. Monitoring the mid-latency auditory evoked responses (AER) has been proposed as a measure to ascertain the adequacy of the hypnotic state during surgery. In the present study, we investigated the presence of explicit and implicit memories after anesthesia and examined the relationships of such memories to the AER.

METHODS

We studied 180 patients scheduled for elective surgical procedures. After a thiopental induction, one of four anesthetics were studied: Opioid bolus: 7.5 microg x kg(-1) fentanyl, 70% N2O, with 2.5 microg x kg(-1) supplements as needed (n=100); Opioid infusion: Alfentanil 50 microg x kg(-1) bolus, 1-1.5 microg x kg(-1) x min(-1) infusion, 70% N2O (n=40); Isoflurane 0.3%: Fentanyl 1 microg x kg(-1), 70% N2O, isoflurane 0.3% expired (n=16); Isoflurane 0.7%: Fentanyl 1 microg x kg(-1), 70% N2O, isoflurane 0.7% expired (n=23). AER were recorded before anesthesia, 5 min after surgical incision and then every 30 min until the end of surgery. A tape of either the story of the "Three Little Pigs" or the "Wizard of Oz" was played continuously between the recordings. Explicit memory was assessed postoperatively by tests of recall and recognition, and implicit memory was assessed by the frequency of story-related free associations to target words from the stories, which were solicited twice during a structured interview.

RESULTS

Six patients showed explicit recall of intraoperative events: All received the opioid bolus regimen. About 7% of patients reported dreaming during anesthesia. The incidence of picking the correct story that had been presented during anesthesia averaged 49%, i.e., very close to chance level. Overall, priming occurred only at the second association tests for the opioid bolus regimen, for which the frequency of an association to the presented story among those not giving an association to the control story was 26%, which was double the frequency (13%) of an association to the control story among those not giving an association to the presented story. This was significant by McNemar's test, P=0.02. There were significant associations between awareness, priming and AER, e.g., recall was associated with higher Nb amplitudes during anesthesia and priming was associated with shorter wave latencies.

CONCLUSIONS

The incidence of awareness in patients anesthetized with nitrous oxide and bolus supplementation was 6%. Thus, this anesthetic technique did not reduce the risk of awareness compared with the use of nitrous oxide alone. Implicit memory occurred during nitrous oxide and bolus supplementation. Recording AER during anesthesia may help to predict awareness and implicit memory, particularly the former. The short contents of most of the dreams which were recalled could hamper future studies in this area.

Vaccinia as a vector for tumor-directed gene therapy: biodistribution of a thymidine kinase-deleted mutant

Tumor-directed gene therapy, such as "suicide gene" therapy, requires high levels of gene expression in a high percentage of tumor cells in vivo to be effective. Current vector strategies have been ineffective in achieving these goals. This report introduces the attenuated (thymidine kinase (TK)-negative) replication-competent vaccinia virus (VV) as a potential vector for tumor-directed gene therapy by studying the biodistribution of VV in animal tumor models. A TK-deleted recombinant VV (Western Reserve strain) expressing luciferase on a synthetic promoter was constructed. Luciferase activity was measured in vitro after transduction of a variety of human and murine tumor cell lines and in vivo after intraperitoneal (i.p.) delivery in C57BL/6 mice with 7-day i.p. tumors (10(6) MC-38 cells). Three other in vivo tumor models were examined for tumor-specific gene expression after intravenous delivery of VV (human melanoma in nude mice, adenocarcinoma liver metastasis in immunocompetent mice, and subcutaneous sarcoma in the rat). In addition, a replication-incompetent vaccinia (1 microg of psoralen and ultraviolet light, 365 nm, 4 minutes) was tested in vitro and in vivo and compared with active virus. Luciferase activity in i.p. tumors at 4 days after i.p. injection of VV was >7000-fold higher than lung, >3000-fold higher than liver, and >250-fold higher than ovary. In addition, intravenous injection of VV resulted in markedly higher tumor luciferase activity compared with any other organ in every model tested (up to 188,000-fold higher than liver and 77,000-fold higher than lung). Inactivation of the virus resulted in negligible gene expression in vivo. In summary, VV has a high transduction efficiency in tumor cells with high levels of gene expression. The results suggest a selective in vivo replication of TK-deleted VV in tumor cells. Replication competent, TK-deleted VV appears to be an ideal vector for testing the in vivo delivery of toxic genes to tumor cells.

Full-time employees of U.S. local health departments, 1992-1993

This article describes a study to assess the most recent data on full-time U.S. local health department (LHD) staff positions. The authors used data from the National Association of County and City Health Officials' 1992-1993 national survey of LHDs. The study concludes that nurses, environmental specialists, sanitarians, and administrators constitute the core of the public health workforce in smaller and mid-sized LHDs. Numerous vacancies in these core occupations signal a weakness in the front lines of public health and vulnerability in its ability to respond to urgent health threats. To address these problems, a renewed commitment to recruiting, retraining, and retaining the local public health worker is urgently needed.

Augmentation of melanoma-specific gene expression using a tandem melanocyte-specific enhancer results in increased cytotoxicity of the purine nucleoside phosphorylase gene in melanoma

The lineage-specific human tyrosinase promoter has been used to successfully target gene expression at the transcriptional level to melanoma cells. The tyrosinase promoter, alone and in combination with a single, or a dual, tandem melanocyte-specific enhancer, was used to regulate expression of the firefly luciferase reporter gene. Transient transfections of these tissue-specific luciferase constructs in human and murine melanoma (Pmel, B16mel) and colon carcinoma (WiDr, MC38) cell lines resulted in melanoma-specific luciferase expression that was amplified 5- and 500-fold with the addition of a single or double enhancer, respectively, to the tyrosinase promoter. When the double enhancer-promoter construct expressed the highly toxic Escherichia coli purine nucleoside phosphorylase (PNP) gene, transfection of the same cell lines followed by administration of the prodrug 6-methyl purine deoxyriboside (6-MPDR) at a concentration of 50 microM caused melanoma-specific in vitro cell killing. Within 5 days after prodrug administration methylthiazol-tetrazolium (MTT) cytotoxicity assays showed that only 15 and 9% of Pmel and B16mel cells, respectively, remained viable compared with controls. This effect was highly specific, as 90 and 96% of WiDr and MC38 colon carcinoma cells remained viable 5 days after identical treatment. This effect was a direct result of increased tissue-specific conversion of 6-MPDR to the toxic metabolite 6-methylpurine (6-MP), as documented by HPLC analysis of culture supernatants. These results show that the dual tandem melanocyte-specific enhancer provides powerful amplification of the transcriptional targeting of gene expression afforded by use of the tyrosinase promoter. This amplification translates into increased, highly specific cytotoxicity to melanoma by the PNP/6-MPDR enzyme/prodrug system and, therefore, has potential efficacy in the use of gene therapy for the treatment of metastatic melanoma.

Thymidine kinase-deleted vaccinia virus expressing purine nucleoside phosphorylase as a vector for tumor-directed gene therapy

Tumor-directed gene therapy faces many obstacles. Lack of tissue targeting and low in vivo transduction efficiency represent some of the limitations for a successful therapeutic outcome. A thymidine kinase-deleted mutant vaccinia virus has been shown in marker studies to replicate selectively in tumor tissue in animal models. Purine nucleoside phosphorylase (PNP), from E. coli, converts the nontoxic prodrug 6-methylpurine deoxyriboside (6-MPDR) to the toxic purine 6-methylpurine. In this study, we investigated the cytotoxic properties of PNP, expressed by an optimized synthetic early/late promoter in a vaccinia virus (vMPPNP). In vitro cytotoxicity of psoralen-inactivated vMPPNP (1 microg of psoralen, 4 min of LWUV [365 nm]) at the maximum tolerated dose (MTD) of 6-MPDR (80 microM) reduced cell viability by day 3 to 1.7%. At an MOI of 0.002, replication-competent vMPPNP and 6-MPDR (80 microM) caused reduction of cell viability to 19.8% within 4 days. Furthermore, there was complete abrogation of viral replication after intracellular conversion of prodrug into the active toxin. The potency of such a system was similar among all histologies tested. Finally, the cytotoxic efficacy has been shown to be more rapid and complete than that of cytosine deaminase (CD), a more established enzyme/prodrug system. When virus was delivered intraperitoneally into athymic mice with hepatic metastases, followed by administration of prodrug, there was a significant prolongation of survival and a 30% cure rate. In summary, owing to its tumor-targeting capabilities, high transduction efficiency, and high gene expression, a vaccinia virus expressing PNP could prove to be a potent and valuable vector for tumor-targeted gene therapy.

Geographic information systems and public health: mapping the future

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Assessing the impact of Medicaid managed care on TB activities in local health departments

Three in-depth case studies were conducted to explore the impact of Medicaid managed care on local health department prevention activities. Tuberculosis (TB) was selected as a sentinel issue because TB includes both clinical treatment and population-based public health considerations (such as surveillance and contact tracing). Overall, study results indicated that there has been a minimal impact on TB prevention and control services, primarily because few TB patients are served by managed care. However, the sites offer many suggestions for areas to monitor, possible collaborative opportunities, and mechanisms to assure continued TB prevention and control.

A model of the quaternary structure of enolases, based on structural and evolutionary analysis of the octameric enolase from Bacillus subtilis

Purified enolase from Bacillus subtilis has a native mass of approximately 370 kDa. Since B. subtilis enolase was found to have a subunit mass of 46.58 kDa, the quaternary structure of B. subtilis is octameric. The pl for B. subtilis enolase is 6.1, the pH optimum (pHo) for activity is 8.1-8.2, and the Km for 2-PGA is approximately 0.67 mM. Using the dimeric Calpha structure of yeast dimeric enolase as a guide, these dimers were arranged as a tetramer of dimers to simulate the electron microscopy image processing obtained for the octameric enolase purified from Thermotoga maritima. This arrangement allowed identification of helix J of one dimer (residues 86-96) and the loop between helix L and strand 1 (HL-S1 loop) of another dimer as possible subunit interaction regions. Alignment of available enolase amino acid sequences revealed that in 16 there are two tandem glycines at the C-terminal end of helix L and the HL-S1 loop is truncated by 4-6 residues relative to the yeast polypeptide, two structural features absent in enolases known to be dimers. From these arrangements and alignments it is proposed that the GG tandem at the C-terminal end of helix L and truncation of the HL-S1 loop may play a critical role in octamer formation of enolases. Interestingly, the sequence features associated with dimeric quaternary structure are found in three phylogenetically disparate groups, suggesting that the ancestral enolase was an octamer and that the dimeric structure has arisen independently multiple times through evolutionary history.

Augmented capillary leak during isolated hepatic perfusion (IHP) occurs via tumor necrosis factor-independent mechanisms

Isolated organ perfusion of the liver or extremity with tumor necrosis factor (TNF) and melphalan results in regression of bulky tumors in the majority of patients. The efficacy of TNF in this setting is not known, although data suggest that it may exert antitumor effects primarily on tumor-associated neovasculature. We studied the effects of TNF on capillary leak in liver and tumor tissue during isolated hepatic perfusion (IHP) with melphalan. Twenty-seven patients with unresectable cancer confined to the liver underwent a 60-min hyperthermic IHP using 1.5 mg/kg melphalan alone (n = 7) or with 1.0 mg of TNF (n = 20). Complete vascular isolation was confirmed in all patients using an intraoperative leak monitoring I-131 radiolabeled albumin technique. Samples of tumor and liver were collected just prior to and immediately after IHP. There was no difference in I-131 radiolabeled cpm/g of tissue (cpm) in liver versus tumor at baseline (P2 = 0.44). After IHP, I-131 albumin cpm were higher in tumor versus liver (10,999 +/- 1,976 versus 3,821 +/- 780, respectively; P2 < 0.005). However, I-131 albumin cpm in tumor were not effected by TNF (11,636 +/- 2,518 with TNF versus 9,180 +/- 2,674 without TNF; P2 = 0.59). TNF did not affect melphalan concentrations in tumor (1,883 +/- 540 ng/g versus 1,854 +/- 861 ng/g without TNF; P2 = 0.9). Capillary leak, as reflected by diffusion of I-131 radiolabeled albumin into the interstitial space, is comparable in liver and tumor before IHP but is significantly higher in tumor after IHP. The increased diffusion in the capillary tumor bed must occur through TNF-independent mechanisms such as intrinsic features of tumor neovasculature, hyperthermia, or other unrecognized perfusion-related factors. These data indicate that TNF must continue to be critically evaluated in clinical trials before it is routinely used with melphalan in isolated organ perfusion.

Intraarterial calcium stimulation and intraoperative ultrasonography in the localization and resection of insulinomas

BACKGROUND

Standard imaging studies (computed tomography, magnetic resonance imaging, somatostatin receptor scintigraphy, ultrasonography, and angiography) correctly localize insulinomas in less than 50% of patients and provide no information about the feasibility of enucleation based on proximity of tumor to pancreatic duct. We reviewed our experience with intraarterial calcium stimulation (Ca-Stim) and intraoperative ultrasonography (IOUS) to localize and guide management of insulinomas.

METHODS

Thirty-six patients (14 men, 22 women, median age 44 years) with insulinomas were treated between August 1989 and June 1996. Preoperative imaging studies were obtained. Patients underwent abdominal exploration with IOUS. Fourteen were evaluated by a surgeon blinded to preoperative imaging results.

RESULTS

Tumors (4 to 50 mm) were resected by enucleation (67%) or partial pancreatectomy (33%); all were cured. Sensitivities of computed tomography, magnetic resonance imaging, somatostatin receptor scintigraphy, ultrasonography, angiography, and Ca-Stim in localizing insulinomas were 24%, 45%, 17%, 13%, 43%, and 94%, respectively. Tumors were identified by blinded surgical exploration with IOUS in 12 of 14 patients (86%).

CONCLUSIONS

All insulinomas were identified before operation; however sensitivity of individual noninvasive tests was low (less than 50%). In contrast, Ca-Stim was correct in 94% of cases, thus allowing a focused pancreatic exploration and obviating use of blind distal pancreatectomy. IOUS can then be used to guide safe enucleation.

The Foot Function Index for measuring rheumatoid arthritis pain: evaluating side-to-side reliability

The Foot Function Index is a validated and reliable instrument for measuring foot pain, disability, and activity restriction in patients with rheumatoid arthritis. For the purposes of orthopaedic studies in which one foot serves as an internal control, we assessed the side-to-side reliability of the seven-question Foot Function Index pain subscale. Thirty patients with rheumatoid arthritis completed visual analog scale pain questionnaires for both feet on two occasions 8 days apart. Internal reliability of the scale was high, with Cronbach's alphas ranging from 0.94 to 0.96, suggesting good left versus right discriminatory abilities. Principal component factor analysis segregated the questions into two large clusters containing predominantly either left or right foot items. Intraclass correlation coefficients were examined for test-retest reliability (separated by side) and for side-to-side reliability (separated by the day of test). The resultant intraclass correlation coefficients were nearly equivalent, ranging from 0.79 to 0.89. Generalizability analysis yielded similar results. Intraclass correlation coefficients and generalizability analysis demonstrate that the majority of variation is best explained by the differences within subjects or between subjects rather than by test-retest or side-to-side differences. We recommend the Foot Function Index as a reliable measurement scale for use in orthopaedic interventional trials.

Effects of dietary calcium and phosphorus on vitamin D metabolism and calcium absorption in hamster

We studied the following responses to restriction of dietary calcium and phosphorus in the growing hamster: (i) serum concentrations of calcium, inorganic phosphorus, magnesium, and vitamin D metabolites; and (ii) calcium transport by ileum. Diets fed were normal calcium with normal or low phosphorus or low calcium with normal or low phosphorus. We found serum 1 alpha,25-dihydroxycalciferol (1,25-[OH]2D) concentration did not differ significantly among the diet groups. Calcium absorption, measured as serosal/mucosal calcium concentration ratio produced by everted ileal sac, was greater in the low calcium, normal phosphorous group than in all other groups. The other groups did not differ from one another in calcium absorption. Feeding the low calcium, normal phosphorus diet increased inorganic phosphorus and magnesium but decreased calcium concentration in serum in comparison with the three other diets. Both low phosphorus diets were without effect on serum calcium, but the low calcium, low phosphorus diet increased serum inorganic phosphorus and magnesium above that of the normal calcium, low phosphorus diet. Ileal calcium absorption in hamster (i) was independent of serum 1,25-(OH)2D concentration; (ii) increased in response to low dietary calcium if dietary phosphorus was normal; and (iii) was independent of dietary calcium, if dietary phosphorus was low. Despite increased calcium absorption, serum calcium was decreased in the low calcium-normal phosphorus group as compared with all other groups. Feeding low calcium diets increased serum inorganic phosphorus and magnesium as compared with feeding the corresponding normal calcium diets (i.e., independently of whether dietary phosphorus content was normal or low). These studies demonstrate that the interrelationships between calcium absorption and vitamin D and mineral metabolism in hamster differ from other mammals.

Descriptive epidemiology of local public health systems

This article, presented at the Research and Measurement of Public Health Core Functions Science Symposium sponsored by the Centers for Disease Control and Prevention (CDC) in June 1994, provides selected data from the 1992-1993 National Profile of Local Health Departments. The National Association of County and City Health Officials (NACCHO), in cooperation with the CDC Public Health Practice Program Office, recently completed the 1992-1993 National Profile of Local Health Departments. This study describes public health at the local level and updates the first Profile study, conducted in 1989. The study population included 2,888 local health departments (LHDs) in the United States. Responses were received from 72% of LHDs. Comparisons are made with the 1990 Profile where available. This article provides a selected overview of the information contained in the 1992-1993 Profile and includes structure of LHDs, top agency executive, staffing, expenditures, and planning. The findings have important ramifications for community health planners and policy makers at all levels. With the ongoing potential for change in the U.S. health care system, reliable data establishing baselines and monitoring trends in public health at the local level are important. The information in this report, and the 1992-1993 National Profile of Local Health Departments, updates and expands the available knowledge of LHD structures and activities.

Preservation of peristaltic reflex in hypertrophied ileum of guinea pig

Chronic obstruction of the guinea pig ileum leads to distension and muscular hypertrophy, but how this affects passive biomechanical and nerve-mediated contractions and clearance known as peristaltic reflex is unclear. Ileum of controls had a diameter of 3.0 +/- 1.1 mm and a circular muscle thickness of 37.2 +/- 11.2 microns; 4 wk after placement of a nonconstricting Gore-Tex band, the ileum was distended to 10.0 +/- 0.19 mm, and its muscle had hypertrophied to 195.0 +/- 61.2 microns. Hypertrophied segments exceeded controls in capacity (e.g., 5.1 +/- 1.1 vs. 1.1 +/0 0.2 ml at 6 cm), compliance, and hysteresis. Threshold volumes and pressures that triggered the reflex were 3.3 +/- 1.3 ml and 3.1 +/- 0.01 mmHg in hypertrophied vs. 0.7 +/- 0.2 ml and 1.5 +/- 0.2 mmHg in controls. The diameter increase that triggered the reflex was 1.4 +/- 0.1 mm in hypertrophied segments and 0.6 +/- 0.1 mm in controls. Hypertrophied segments generated fewer contractions of virtually double the amplitude and failed to generate a pressure differential between up- and downstream sites as controls did. Hypertrophied segments generated larger stroke volumes and cumulative clearance than controls. The ratio of antegrade to retrograde clearance was similar in hypertrophied and control segments. The length of the occluding segment in hypertrophied preparations exceeded that of controls. Control contractions indented the antimesenteric border and propagated antegrade from their site of origin; bizarre writhing movements of hypertrophied segments made their contractions difficult to monitor. Thus distension and muscular hypertrophy do not interfere with the ability of the chronically obstructed guinea pig ileum to generate a peristaltic reflex at least as readily and as powerful and as effective in clearing the lumen as controls.

Survival of patients with localized prostate cancer treated with percutaneous transperineal placement of radioactive gold seeds: stages A2, B, and C

Between 1984 and 1991, a total of 177 patients with adenocarcinoma of the prostate were treated with transcutaneous, transperineal radioactive gold seeds. Of these 177 patients, 20 were determined to have pelvic lymph node involvement and were excluded from this review. The remaining 157 patients received a median radioactivity dose of 164 mCi with a median follow-up of 48 months. Cancer-specific survival at 5 years was 100% for stage A2 and B1, 90% for stage B2, and 76% for stage C cancer. Covariates of grade, total radioactivity administered, age of the patient, and number of seeds implanted did not influence disease-free survival in a statistically significant manner. Significant complications were observed in two patients. The survival rates of patients treated with 198Au seed implantation for localized cancer are equivalent or better when compared to historical data of patients treated with 125I implantation, external beam radiotherapy, combination radioactive gold seed implantation and external irradiation, and radical prostatectomy. In addition, these comparable survival rates using interstitial 198Au seeds may be achieved with less morbidity.

Discharge instructions: do illustrations help our patients understand them?

STUDY OBJECTIVE

To determine whether the addition of illustrations to discharge instructions improves patient comprehension.

DESIGN

Randomized, blinded, prospective study. A blinded investigator asked a series of questions designed to test the participant's comprehension of the discharge instructions. There were 10 possible correct responses.

SETTING

Emergency department of a rural Level I trauma center.

PARTICIPANTS

Convenience sample of 101 patients discharged with the diagnosis of laceration.

INTERVENTIONS

Patients were randomly assigned to receive discharge instructions with (n = 54) or without (n = 47) illustrations.

RESULTS

The median number of correct responses was five. Patients with illustrations were 1.5 times more likely to choose five or more correct responses than those without illustrations (65% versus 43%; P = .033). The effect of illustrations varied by demographic group. Among nonwhites (n = 51), patients with illustrations were more than twice as likely to choose five or more correct responses (P = .032). Among patients with no more than a high school education (n = 71), patients with illustrations were 1.8 times more likely to choose five or more correct responses (P = .038). Among women (n = 48), patients with illustrations were 1.7 times more likely to chose five or more correct responses (P = .006).

CONCLUSION

The addition of illustrations to discharge instructions for patients who have sustained lacerations improves patient comprehension. There is a large effect among patients who are nonwhite, female, or have no more than a high school education.

Conference attendance: do we meet the new residency review committee requirements?

STUDY OBJECTIVES

To characterize the attendance at and presenters of conferences given to emergency medicine residents and to determine the ability of emergency medicine residents to attend conferences while working in the emergency department and on off-service rotations.

DESIGN

Descriptive study of an anonymous mail survey.

PARTICIPANTS

Residency directors of all approved emergency medicine residency programs in the United States.

RESULTS

Seventy-six of 95 questionnaires (80%) were returned. We defined "high attendance" at emergency medicine conferences as a reported average of at least 75% attendance by emergency medicine resident physicians. Fifty percent of respondents reported high attendance. Conversely, 17% of programs reported poor attendance, which we defined as an average attendance by 50% or fewer emergency medicine resident physicians. Forty-eight percent of programs reported that emergency medicine faculty conducted more than 50% of the conferences, and 16% reported that the faculty conducted 25% or fewer conferences. Ninety-six percent of programs allowed residents to attend conferences during off-service rotations. Ninety-two percent of programs relieved residents of clinical responsibilities during scheduled shifts in the emergency department so that they might attend lectures.

CONCLUSION

We found that a sizable proportion of programs may not have met the new Residency Review Committee requirements for lecture attendance at the time the guidelines were issued. The vast majority of programs met guidelines for relief of clinical duties, and a large proportion of programs exceeded the requirements for percentage of lectures given by emergency medicine faculty.

Subcuticular sutures and the rate of inflammation in noncontaminated wounds

STUDY OBJECTIVE

To determine whether buried, absorbable, subcuticular sutures increase the degree of inflammation in noncontaminated wounds.

DESIGN

Randomized, blinded, prospective trial.

SETTING

Laboratory.

PARTICIPANTS

Eleven Sprague-Dawley rats weighing 300 to 325 g.

INTERVENTIONS

Four wounds were made on each rat. Two wounds on each were closed with three interrupted buried, absorbable, subcuticular sutures 6-0 polyglactin 910 and running 5-0 nylon skin sutures. The other two wounds were closed with running 5-0 nylon skin sutures alone.

RESULTS

Fourteen days after the sutures were placed, the animals were killed, and histologic preparations were made from each wound. Each sample was scored on a scale of 0 to 3 for the presence of inflammatory infiltrates, fibroplasia and capillary proliferation, necrosis, exudates, giant cells, and edema. We determined a total wound score by adding the scores from each category. The mean total wound score was 4.46 +/- 2.92 for those closed with buried, absorbable, subcuticular sutures and 4.91 +/- 2.56 for those closed without buried, absorbable, subcuticular sutures. Using the Wilcoxon rank-sum test, we found no statistically significant difference in mean total wound score of wounds closed with and without buried, absorbable, subcuticular sutures (alpha = .01). The probability of detecting a twofold difference in total wound scores was 60% (beta = .40).

CONCLUSION

Buried, absorbable, subcuticular sutures do not significantly increase the degree of inflammation in noncontaminated wounds.

Physician compliance with advanced cardiac life support guidelines

STUDY OBJECTIVE

To determine compliance with advanced cardiac life support (ACLS) guidelines among ACLS-certified and non-ACLS-certified physicians.

DESIGN

Retrospective review of consecutive cardiac arrests between July 1989 and June 1990, including assessment of the resuscitation leaders' ACLS certification.

SETTING AND PARTICIPANTS

All nontraumatic prehospital and hospital cardiac arrests in a rural university hospital.

RESULTS

Two hundred seven arrests were studied for a total of 436 rhythms with a maximum of 4 rhythms per arrest. There were 78 resuscitations (36.3%) with return of spontaneous circulation. A total of 2,038 interventions were recorded for all rhythms, with 1,320 (64.8%) compliant with ACLS guidelines compared with 718 (35.2%) deviations. Synchronized cardioversion, calcium chloride and sodium bicarbonate were used with significantly higher noncompliance. Ventricular fibrillation had significantly higher mean rhythm deviation scores, whereas scores were significantly lower for sinus rhythm and stable bradycardia (P < .003). Resuscitations led by ACLS-certified and non-ACLS-certified physicians were compared for mean number of deviations per resuscitation attempt, and no differences were found. Resuscitations with return of spontaneous circulation were compared with unsuccessful resuscitations, and there was no difference between groups in controlled deviation scores. No differences could be found between ACLS-certified and non-ACLS-certified physicians for return of spontaneous circulation and survival-to-discharge rates.

CONCLUSION

Despite biannual ACLS training of all medical residents and ICU nurses, noncompliance with ACLS guidelines was noted in 35.2% of treatments. We found no correlation between ACLS certification and ACLS guideline compliance.

Strenuous exercise decreases motility and cross-sectional area of human gastric antrum. A study using ultrasound

Gastric emptying in humans is delayed with strenuous exercise. We used ultrasound imaging in six healthy volunteers to determine whether changes in motility and configuration of the gastric outlet contribute to this delay. After fasting, all individuals ingested chicken broth and garbanzo beans. With subjects sitting upright, transverse and longitudinal real-time views of the gastric antrum were recorded on video tape. In the exercise studies, subjects pedaled an ergometer for 10 min to attain a heart rate of 85% predicted maximum. On a different day, all subjects had an identical study without exercise. The order of performance of exercise and no-exercise studies was randomized. After exercise, contraction frequencies and antral areas were significantly reduced compared to the studies without exercise. In addition, after exercise there was closure of the pylorus and tubular narrowing of the gastric antrum. Closure of the pylorus and decreased gastric antral area and motility may be important in explaining the decrease in gastric emptying that occurs with strenuous exercise.

The association of HLA-B8, B51, DR2, and multiple sclerosis in pars planitis

PURPOSE

To establish a human leukocyte antigen (HLA) association in a homogeneous population of patients with pars planitis.

METHODS

A strict set of inclusion parameters was established for the diagnosis of pars planitis. Forty patients with pars planitis who met these criteria underwent HLA analysis of class I and II phenotypes.

RESULTS

HLA-B8 was present in 15 (37.5%) of 40 patients versus 85 (19.7%) of 431 controls (relative risk, 2.44; P = 0.011). HLA-B51 was present in 9 (22.5%) of 40 patients versus 51 (11.8%) of 431 controls (relative risk, 2.16; P = 0.049). HLA-DR2 was present in 27 (67.5%) of 40 patients versus 121 (28.0%) of 431 controls (relative risk, 5.32; P < 0.0001). HLA-DR2 has been associated with multiple sclerosis (MS). Exclusion of five patients with pars planitis in whom MS subsequently developed did not change the significance of these findings.

CONCLUSIONS

The strongest association of pars planitis with HLA-DR2 and the temporal development of MS in some patients with pars planitis further supports an association between pars planitis and MS.

Retained foreign body: a fingernail fragment?

A 19-year-old female presented four and one-half months after an occupational injury from a punch-type machine. Exploration revealed a large fragment of her fingernail embedded in the fingerpad. Foreign bodies are commonly encountered in the practice of emergency medicine and failure to localize and remove them can result in significant morbidity. We present a case of a fingernail as a foreign body. Foreign bodies may be difficult to detect despite sophisticated imaging techniques. Although not visualized often, a radiolucent foreign body may be inferred from boney changes. A thorough history regarding mechanism of injury and resultant wound exploration are required. When an adequate wound examination using digital tourniquet control and proper precautions is performed, the majority of foreign bodies will be detected.

Long-term speech results of cleft palate patients with primary palatoplasty

This investigation examined the influence of cleft type, type of surgery, age at surgery, and gender on speech proficiency of 204 patients with cleft palate who required only primary palatoplasty. Speech measures were obtained for each subject from at least three annual examinations between the ages of 4 and 16 years. Neither age at surgery nor type of surgery were discriminating factors. The less extensive cleft type, i.e., soft palate only, was associated with greater rates of change in the performance variables than were the other three cleft types. Females showed greater rate changes than males.

Marine trauma, envenomations, and intoxications

When humans encounter marine creatures a variety of maladies may occur, ranging from dermatitis to life-threatening trauma, allergy, envenomations, or intoxications. The emergency physician should be prepared to recognize quickly and address appropriately the potential life threats, which are primarily neurologic, respiratory, and cardiovascular. A high degree of suspicion for these illnesses is needed. Intoxications may be especially confusing. Although most of the syndromes are self-limited and treatment supportive, time is of the essence if neuromuscular paralysis, hypotension, or respiratory compromise is present. Much folklore exists regarding detection and prevention of these entities and should be regarded as such. The last several decades have seen a marked increase in our knowledge base regarding these fascinating envenomations and intoxications. Research in the next several decades probably will produce a variety of diagnostic and therapeutic tools, which will further our understanding of, and ability to specifically manage, these syndromes.

Intraosseous transfusion in an anesthetized swine model using 51Cr-labeled autologous red blood cells

Peripheral venous access can often be difficult to obtain in infants and young children. Landmark articles in the 1940s showed that the intraosseous (IO) route was a viable one for resuscitation. While anecdotal reports and clinical experience suggest that blood products can be transfused via the IO route, it has not been specifically studied nor documented. We performed a prospective study to document the feasibility of red blood cell transfusion via the IO space. We studied the rapid infusion of 51Cr-labeled red blood cells via the IO space through an 18-gauge IO needle in three normovolemic immature swine. Serial central venous samples were removed at 30 seconds and at 1, 5, 15, 30, and 60 minutes and analyzed for evidence of radiolabeling. Our results revealed rapid delivery of radiolabeled red blood cells into the central circulation with no evidence of early heomolysis. Highest counts were seen in samples taken at 30 seconds to 1 minute. We conclude that the IO route is a viable means for blood transfusion in a nonhemorrhagic model.