Mast cell degranulation and parenchymal cell injury in the rat mesentery.

OBJECTIVE: The objective of this study was to explore the degree of parenchymal cell injury after mast cell degranulation by application of compound 48/80 (CMP 48/80) in the absence of adherent leukocytes in the rat mesentery. METHODS: Rats were rendered leukopenic by injection of an antibody against leukocytes, and the mesentery was superfused with CMP 48/80 during intravital microscopy. The extent of cell injury was determined using a fluorescent cell-viability indicator, propidium iodide (PI). In an additional group, mast cell degranulation with CMP 48/80 was prevented by using the mast cell stabilizer Ketotifen. RESULTS: After a reduction in the number of circulating leukocytes, mast cell degranulation produced a mild increase in parenchymal cell injury. The injury levels significantly increased when individual regions of the mesentery were compared. Stabilization of the mast cells with Ketotifen reduced the injury to below baseline values. CONCLUSIONS: In the absence of leukocyte adhesion to the endothelium, mast cell degranulation contributes to parenchymal cell injury in the mesentery.     

Serial Lead Impedance Measurements Confirm Fixation of Helical Screw Electrodes During Pacemaker Implantation

The purpose of this study was to determine whether serial measurements of helical screw pacemaker lead impedance could reliably confirm electrode fixation in the right atrium and right ventricle. Fixation is generally assessed fluoroscopically, which can be misleading because the myocardium is radio lucent. Alternatively, because the electrical conductivity of blood is greater than that of myocardium, serial measurements of the lead impedance might be expected to show an impedance increase with appropriate fixation of the pacemaker electrode when the electrode becomes embedded in myocardial tissue. Impedance measurements were made during the placement of 23 atrial and 28 ventricular active fixation electrodes in 31 consecutive patients. Impedance measurements were recorded in unipolar and bipolar electrode configurations with the electrode free floating in the chamber, unfixed (with exposed screws) but touching the endocardial surface, and after fixation. No significant impedance differences were found between free-floating and unfixed electrode positions. With fixation, the lead impedance increased significantly in the ventricle (P = 0.0001, unipolar and bipolar) and the atrium (P = 0.0069 unipolar and 0.0052 bipolar). Typical increases, reflected by median values, were 197 ohms unipolar and 203 ohms bipolar in the ventricle and 47 ohms unipolar and 53 ohms bipolar in the atrium for electrodes with permanently exposed or retractable screw designs. Comparing serial measurements of lead impedance before and after electrode fixation is a valid electrical method of confirming appropriate fixation of helical screw electrodes.     

Genotype does not predict severity of behavioural phenotype in juvenile neuronal ceroid lipofuscinosis (Batten disease)

Aim The primary aim of this investigation was to examine genotype and clinical phenotype differences in individuals with juvenile neuronal ceroid lipofuscinosis (JNCL) who were homozygous for a common disease‐causing deletion or compound heterozygous. The secondary aim was to cross‐validate the Child Behavior Checklist (CBCL) and the Unified Batten Disease Rating Scale (UBDRS), a disease‐specific JNCL rating scale. Method Sixty individuals (28 males, 32 females; mean age 15y 1mo, SD 4y 9mo, range 5y 8mo–31y 1mo) with JNCL completed the UBDRS. Results No significant genotype and clinical phenotype differences were identified when comparing individuals homozygous for the deletion with a heterogeneous group of compound heterozygous individuals. There were significant correlations among related behaviour items and scales on the CBCL and UBDRS (Spearman’s rho ranging from 0.39 [p<0.05] to 0.72 [p<0.01]). Behaviour and physical function ratings were uncorrelated, supporting divergent validity of these two constructs in JNCL. Interpretation Previous reports of genotype and clinical phenotype differences were unsupported in this investigation, which did not find differences between individuals homozygous or heterozygous for the CLN3 deletion. The CBCL, an already validated measure of behaviour problems, appears valid for use in JNCL and cross‐validates well with the UBDRS.     

Medicaid Waivers and Tenancy Supports for Individuals Experiencing Homelessness: Implementation Challenges in Four States

Policy Points

• Medicaid policymakers have a growing interest in addressing homelessness as a social determinant of health and driver of the potentially avoidable use of expensive medical services.
• Drawing on extensive document reviews and in‐depth interviews in four early‐adopter states, we examined the implementation of Medicaid''s Section 1115 demonstration waivers to test strategies to finance tenancy support services for persons experiencing or at risk of homelessness.

ContextThe Affordable Care Act extended Medicaid eligibility to large numbers of individuals experiencing or at risk of homelessness. This legislative development and the growing recognition of homelessness as a significant social determinant of health have encouraged advocates and policymakers to seek new ways to use Medicaid to provide housing supports.MethodsWe conducted 28 semistructured interviews with 36 stakeholders in four states. The stakeholders were government administrators, health care providers, nonprofit housing staff, and consultants. We supplemented these interviews with extensive reviews of public documents, media accounts, think‐tank reports, and published literature. We also conducted a systematic inductive qualitative analysis.FindingsWe identified seven challenges to the successful implementation of tenancy support demonstration projects: resolving the housing supply and NIMBY, removing silos between health care and homeless services providers, enrolling and retaining the target populations in Medicaid, contracting with and paying tenancy support providers, recruiting and retaining key workers, ensuring Medicaid''s waiver durability, and reducing administrative crowd‐out and waiver burden.ConclusionsNotwithstanding these challenges, three of the four states have made significant progress in launching their initiatives. At this point, the fourth state has delayed its start‐up to consider alternatives to a Medicaid demonstration waiver to provide tenancy supports. The experience of the four states suggests lessons for Medicaid officials in other jurisdictions that are interested in pursuing tenancy support initiatives. Nevertheless, the limitations of tenancy support waiver programs suggest that federal policymakers should consider allowing states to more directly subsidize housing costs for those experiencing or at risk of homelessness as an optional Medicaid benefit.     

Thermographic assessment of patch-test responses

Infra-red thermography was used to quantify, at patch test sites, the allergic responses to experimental preparations of nickel sulphate and primary irritant responses to sodium lauryl sulphate in small groups of volunteers. The technique was also used to assess the patch-test responses in a much larger group of patients who had undergone routine patch testing for contact allergy with a wide range of test substances and among which there were large numbers of allergic, irritant and equivocal reactions. Thermographically, when compared to the surrounding normal skin surface, the sites of allergic reactions appeared as hot areas, the temperature and area of which were apparently dependent on the severity of the response. For allergic responses, there was a good correlation between the clinical assessment and either of two thermographic parameters, temperature and area of involvement. Compared with an aqueous solution of nickel sulphate, 'poor' formulations of the allergen, such as a suspension in soft paraffin base, elicited smaller and cooler reactions. Irritant reaction sites were not 'hot' and the temperature at such sites was no different from that of the surrounding normal skin. Infra-red thermography is a convenient non-invasive technique which apparently can be used to discriminate between irritant and allergic responses and to quantify the latter type of response.     

Level of Confidence in Diagnosis: Clinical Examination Versus Dermoscopy Examination

BACKGROUND: Confidence is an important factor in decision making and may influence patient care. OBJECTIVES: To evaluate whether short-training-based dermoscopy increases confidence in the diagnosis of skin lesions. METHODS AND MATERIALS: After a 1-hour course on dermoscopy, 20 pairs of clinical and dermoscopic images of lesions were presented to 19 dermatology residents with little or no dermoscopy experience. After viewing the clinical image, they were asked to assess their confidence in the diagnosis in a seven-point scale, with 1 reflecting that the respondent was 100% confident that the lesion was benign, while number 7 reflected 100% confidence that it was malignant. The same technique was used for dermoscopic images. RESULTS: Ten of the 20 pairs of evaluations showed a significant difference (p<.05). The largest differences were observed in lesions where clinical scores suggested that participants were uncertain about the diagnosis, but tended to decide that the lesion was benign after dermoscopy. Dermoscopy did not improve confidence in the evaluation of dysplastic lesions as well as lesions with obvious clinical diagnoses. CONCLUSIONS: Short-training-based dermoscopy improved confidence in the diagnosis of clinically challenging skin lesions, but the impact was not demonstrable for clinically obvious lesions and dysplastic nevi.     

The NASPE */BPEG ** Defibrillator Code

A new generic code, patterned after and compatible with the NASPE/BPEG Generic Pacemaker Code (NBG Code) was adopted by the NASPE Board of Trustees on January 23. 1993. It was developed by the NASPE Mode Code Committee, including members of the North American Society of Pacing and Electrophysiology (NASPE) and the British Pacing and Electrophysiology Croup (BPEC). It is abbreviated as the NBD (for NASPE/BPEC Defibrillator) Code. It is intended for describing the capabilities and operation of implanted cardioverter defibrillators (ICDs) in conversation, record keeping, and device labeling, and incorporates four positions designating: (1) shock location; (2) antitachycardia pacing location; (3) means of tachycardia detection; and (4) antibradycardia pacing location. An additional Short Form, intended only for use in conversation, was defined as a concise means of distinguishing devices capable of shock alone, shock plus antibradycardia pacing, and shock plus antitachycardia and antibradycardia pacing.     

Myelographic Differentiation of Spinal Cord Arteriovenous Malformations from the Normal Population

Vascular filling defects are a normal feature of the thoracic myelogram. The aim of this paper was to provide criteria for differentiating the vascular filling defects in spinal AVM's from the range of filling defects seen in non-AVM patients. Out of 940 consecutive thoracic myelograms, in non-AVM patients, 505 had vascular filling defects. These were compared with the myelographic features of nine spinal AVM's, with regard to vessel diameter, length, tortuosity and number. None of these criteria were diagnostic of AVM's as there was overlap bet ween the vascular filling defects of AVM's and the range of normal spinal cord vessels, especial ly posterior spinal veins. However, filling defects greater than 1.4 mm diameter, which are excessively tortuous, long and. multiple, should be regarded as highly suspinous of an AVM. A lateral film is important when vascular filling defects are seen, for if these filling defects are anterior to the cord, an AVM is more likely.