Principles and philosophies for speech and language therapists working with people with primary progressive aphasia: an international expert consensus

PURPOSE

Primary progressive aphasia (PPA) is a language-led dementia associated with Alzheimer's pathology and fronto-temporal lobar degeneration. Multiple tailored speech and language interventions have been developed for people with PPA. Speech and language therapists/speech-language pathologists (SLT/Ps) report lacking confidence in identifying the most pertinent interventions options relevant to their clients living with PPA during their illness trajectory.

MATERIALS AND METHODS

The aim of this study was to establish a consensus amongst 15 clinical-academic SLT/Ps on best practice in selection and delivery of speech and language therapy interventions for people with PPA. An online nominal group technique (NGT) and consequent focus group session were held. NGT rankings were aggregated and focus groups video recorded, transcribed, and reflexive thematic analysis undertaken.

RESULTS

The results of the NGT identified 17 items. Two main themes and seven further subthemes were identified in the focus groups. The main themes comprised (1) philosophy of person-centredness and (2) complexity. The seven subthemes were knowing people deeply, preventing disasters, practical issues, professional development, connectedness, barriers and limitations, and peer support and mentoring towards a shared understanding.

CONCLUSIONS

This study describes the philosophy of expert practice and outlines a set of best practice principles when working with people with PPA.Implications for rehabilitationPrimary progressive aphasia (PPA) describes a group of language led dementias which deteriorate inexorably over time.Providing speech and language therapy for people with PPA is complex and must be person centred and bespoke.This study describes the philosophy of expert practice and outlines a set of best practice principles for speech and language therapists/pathologists working with people with people with PPA.

Association of Patient Reported Global Health Measures with Frailty Scores in Acutely Injured Older Adults

Purpose: The older population is particularly vulnerable to traumatic injury. Frailty scores, used to estimate the physiologic status of an individual, are key to identifying those most at risk for injury. Global health measures such as the Veterans RAND 12 Item Health Survey (VR-12) are quality of life measures that assess older adults’ overall perception of their health and may serve as a useful adjunct when predicting frailty. Herein, we evaluated whether components of the VR-12 correlated with worse frailty scores over time. Methods: Older adults (≥65) admitted to burn, trauma, or emergency general surgery services were prospectively enrolled. Demographics, frailty determined using the Trauma Specific Frailty Index (TSFI), and VR-12 surveys were collected at enrollment and 3, 6, 9, and 12-month follow-ups. A physical component score (PCS) and mental component score (MCS) was produced by VR-12 surveys for comparison purposes. Results: Fifty-eight patients were enrolled, of which 8 died. No significant changes in PCS (p = 0.25) and MCS (p = 0.56) were observed over time. PCS (p = 0.97) and MCS (p = 0.78) at enrollment did not predict mortality. PCS (OR = 0.894 [0.84-0.95], p = 0.0004) and age (OR = 1.113 [1.012-1.223], p = 0.03) independently predicted enrollment frailty. Conclusion: These global measures of health could be utilized in lieu or in addition to frailty scores when assessing patients in the setting of acute injury. Studies are warranted to confirm this association.

Intraoperative distensibility measurement during laparoscopic Heller's myotomy for achalasia may reduce the myotomy length without compromising patient outcome

Our study aimed to assess whether intraoperative esophagogastric junction (EGJ) distensibility measurement using the EndoFLIP EF325 catheter (Crospon Ltd., Galway, Ireland) could potentially be used to guide laparoscopic Heller's myotomy (LHM), potentially modifying the operation outcome and comparing this clinically to our previous technique of gastroscopic assessment. Following a full diagnostic assessment with manometry and endoscopy patients with achalasia were divided into two groups. A retrospective cohort of patients operated on between 2007 and 2010 had a gastroscopy-guided LHM (G-LHM) with a standardized myotomy of 8 cm on the esophagus and 3 cm on the stomach. From 2010, patients were prospectively studied with an EndoFLIP-guided LHM (E-LHM). The length of the myotomy was dictated by intraoperative distensibility monitoring of the EGJ. All patients with achalasia recorded Urbach quality of life scoring preoperatively and 6 months postoperatively. A further group of normal laparoscopic control patients (E-LC) without any esophageal pathology also underwent intraoperative EGJ distensibility monitoring. Thirty-eight patients took part, 15 in the E-LC group, 8 in G-LHM group and 15 in the E-LHM group. We revealed that patients with achalasia in the E-LHM group had a significantly smaller EGJ cross-sectional area and distensibility than the E-LC group. Myotomy and fundoplication increased the distensibility of the EGJ to a value greater than normal control patients. Patients in the G-LHM group had a standard myotomy of 11 cm; patients in the E-LHM group had a variable length myotomy of 6 cm (IQR 5.0-6.0). In both G-LHM and E-LHM groups, there was a significant improvement in patient's quality of life with no significant difference between the groups. Our study has shown that the EndoFLIP system was effective at measuring distensibility changes during LHM. LHM significantly increases the distensibility of the EGJ and also significantly improves patient symptoms. E-LHM may reduce the overall myotomy length, and this does not appear to compromise the clinical outcome.

Ivor-Lewis oesophagogastrectomy with Roux-en-Y duodenal bypass

Oesophagectomies and gastrectomies are performed predominantly for the treatment of malignant disease. However, in this case series, we describe three patients with benign disease who had a laparoscopic oesophagogastrectomy with gastroduodenal detachment and Roux-en-Y biliary diversion, and discuss the operative feasibility and consequent patient outcomes. Our aim was to modify the procedure using an established reconstruction already practised in gastric and bariatric surgery, thereby preventing operative sequelae that lead to a poor quality of life (eg reflux oesophagitis and vomiting). During the first postoperative year, our first two patients experienced weight loss, indigestion and lower bowel symptoms with no apparent improvement in gastric function compared with a standard gastric tube pull-up reconstruction. In the longer term, in both patients, the gastric tube interpositions appeared to function well and there was no evidence of gastro-oesophageal reflux disease, delayed gastric emptying or troublesome indigestion. Our third patient, who had lifelong severe reflux symptoms, was eating normally three months after the operation with no need for antacid medication. We therefore conclude that laparoscopic Ivor-Lewis oesophagogastrectomy with Roux-en-Y bypass is a more complex reconstruction with added risks but may in the long term result in better overall outcomes and satisfaction for patients, particularly those with benign disease.

Ongoing outbreak of Shigella flexneri serotype 3a in men who have sex with men in England and Wales, data from 2009–2011

Diagnoses of Shigella flexneri in the United Kingdom (UK) are usually travel-related. However, since 2009, there has been an overall increase in UK-acquired cases. The Health Protection Agency has been investigating a national outbreak of S. flexneri detected in 2011 and which is still ongoing. Cases occurred mostly in men who have sex with men and were of serotype 3a. The investigation aimed at obtaining epidemiological data to inform targeted outbreak management and control.

Ongoing outbreak of Shigella flexneri serotype 3a in men who have sex with men in England and Wales, data from 2009-2011

Diagnoses of Shigella flexneri in the United Kingdom (UK) are usually travel-related. However, since 2009, there has been an overall increase in UK-acquired cases. The Health Protection Agency has been investigating a national outbreak of S. flexneri detected in 2011 and which is still ongoing. Cases occurred mostly in men who have sex with men and were of serotype 3a. The investigation aimed at obtaining epidemiological data to inform targeted outbreak management and control.

Can we use medical examiners’ records for suicide surveillance and prevention research in Nova Scotia?

Introduction

Medical examiners’ records can contribute to our understanding of the extent of suicide in a population, as well as associated sociodemographic and other factors.

Methods

Using a mixed methods approach, the key objective of this pilot study was to determine the sources and types of information found in the Nova Scotia Medical Examiner Service (NSMES) records that might inform suicide surveillance and targeted prevention efforts. A secondary objective was to describe the one-year cohort of 108 individuals who died by suicide in 2006 in terms of available sociodemographic information and health care use in the year prior to death.

Results

Data extraction revealed inconsistencies both across and within files in terms of the types and amounts of sociodemographic and other data collected, preventing correlational analyses. However, linkage of the records to administrative databases revealed frequent health care use in the month prior to death.

Conclusion

The introduction of systematic data collection to NSMES investigations may yield a comprehensive dataset useful for policy development and population level research.

Can we use medical examiners' records for suicide surveillance and prevention research in Nova Scotia?

INTRODUCTION

Medical examiners' records can contribute to our understanding of the extent of suicide in a population, as well as associated sociodemographic and other factors.

METHODS

Using a mixed methods approach, the key objective of this pilot study was to determine the sources and types of information found in the Nova Scotia Medical Examiner Service (NSMES) records that might inform suicide surveillance and targeted prevention efforts. A secondary objective was to describe the one-year cohort of 108 individuals who died by suicide in 2006 in terms of available sociodemographic information and health care use in the year prior to death.

RESULTS

Data extraction revealed inconsistencies both across and within files in terms of the types and amounts of sociodemographic and other data collected, preventing correlational analyses. However, linkage of the records to administrative databases revealed frequent health care use in the month prior to death.

CONCLUSION

The introduction of systematic data collection to NSMES investigations may yield a comprehensive dataset useful for policy development and population level research.

Lymphoid and myeloid cell populations in the non-pregnant human Fallopian tube and in ectopic pregnancy

Lymphoid and myeloid cell populations in human endometrium are well-documented and are known to play important roles in providing immune tolerance, controlling trophoblast invasion, and mediating vascular remodeling. Immune cell populations in the Fallopian tube have not been comprehensively studied. The aim of this study was to characterize lymphoid and myeloid cell populations in non-pregnant Fallopian tube and determine whether they are altered in Fallopian tube from women with ectopic pregnancy. Fallopian tube was analyzed by flow cytometry and immunohistochemistry. Populations of CD3+ (CD4+ and CD8+) lymphocytes, LIN1-HLADR+ (CD123+ and CD11c+) dendritic cells, monocytes, neutrophils, and CD56(dim)CD16- natural killer (NK) cells were demonstrated to be present in non-pregnant Fallopian tube. CD123+ dendritic cells were predominant over CD11c+ dendritic cells. Numbers of CD11c+ cells were significantly higher in the progesterone-dominant mid-luteal phase of the menstrual cycle compared with the follicular phase. Numbers of CD45+ leukocytes, CD68+ cells, and CD11c+ cells were higher in Fallopian tube from women with ectopic pregnancy compared with mid-luteal phase Fallopian tube. These data will advance our understanding of normal human Fallopian tube physiology and disorders of Fallopian tube function, such as ectopic pregnancy.

Affective-prosodic deficits in schizophrenia: comparison to patients with brain damage and relation to schizophrenic symptoms [corrected]

OBJECTIVE

Although affective prosody seems to be a dominant and lateralised communication function of the right hemisphere, focal lesions of either hemisphere may cause problems with its modulation. When impairment occurs after brain damage, the profiles of affective-prosodic disturbances differ depending on the hemisphere injured. Patients with left brain damage (LBD) improve their performance whereas patients with right brain damage (RBD) do not when the verbal-articulatory demands of the test stimuli are reduced systematically. One of the major arguments for a right hemispheric contribution to schizophrenia has been the documentation of affective prosodic deficits under the assumption that these abnormalities reflect right hemispheric dysfunction. Thus, an essential question to resolve is whether the profile of affective prosodic disturbances in schizophrenia is similar to LBD or RBD, or represents a unique variation.

METHODS

Data were collected from four subject groups: 45 chronic, medication-stabilised, schizophrenic patients, 10 patients with focal LBD, nine patients with focal RBD, and 19 controls. All groups were tested on the aprosodia battery, which uses stimuli having incrementally reduced verbal-articulatory demands. Schizophrenic and aphasic symptoms were evaluated using standard assessment tools.

RESULTS

For patients with impaired performance on the aprosodia battery, schizophrenic patients were statistically identical to patients with RBD and robustly different from those with LBD. Thirty eight schizophrenic patients (84.4%) were found to have some type of affective prosodic deficit with the predominant pattern indicating, at minimum, right posterior sylvian dysfunction (57.8%). When schizophrenic symptoms and aprosodic deficits were examined using a principal component analysis, affective comprehension and repetition loaded uniquely as separate factors.

CONCLUSIONS

The profile of affective-prosodic deficits found in impaired schizophrenic patients is characteristic of RBD, supporting the concept that schizophrenia is a bihemispheric disease process. These deficits may also represent cardinal symptoms of schizophrenia as they are highly prevalent and, except for spontaneous affective prosody, are not associated statistically with traditional clusters of schizophrenic symptoms.

Early Oligocene initiation of North Atlantic Deep Water formation

Dating the onset of deep-water flow between the Arctic and North Atlantic oceans is critical for modelling climate change in the Northern Hemisphere and for explaining changes in global ocean circulation throughout the Cenozoic era (from about 65 million years ago to the present). In the early Cenozoic era, exchange between these two ocean basins was inhibited by the Greenland-Scotland ridge, but a gateway through the Faeroe-Shetland basin has been hypothesized. Previous estimates of the date marking the onset of deep-water circulation through this basin-on the basis of circumstantial evidence from neighbouring basins-have been contradictory, ranging from about 35 to 15 million years ago. Here we describe the newly discovered Southeast Faeroes drift, which extends for 120 km parallel to the basin axis. The onset of deposition in this drift has been dated to the early Oligocene epoch ( approximately 35 million years ago) from a petroleum exploration borehole. We show that the drift was deposited under a southerly flow regime, and conclude that the initiation of deep-water circulation from the Norwegian Sea into the North Atlantic Ocean took place much earlier than is currently assumed in most numerical models of ancient ocean circulation.

Structure and function of the proteins of the mammalian Zona pellucida

The zona pellucida (ZP) is the extracellular matrix that plays important roles in sperm-egg interaction. The ZP is composed of three major glycoproteins that exhibit heterogeneity due to extensive post-translational modifications including glycosylation and sulfation. Because of these modifications the nomenclature of ZP proteins from different species based on electrophoretic mobilities has been confusing. As the cDNAs and genes encoding the different ZP proteins have been isolated and sequenced, it is now possible to relate these ZP proteins according to gene families. Using the mouse ZP nomenclature, the ZP proteins from different mammalian species can be classified into three protein families: ZP1, ZP2, and ZP3. Although some of the structural domains of the ZP proteins of different species are conserved within each family, they exhibit distinct biological properties. In the mouse it has been established that ZP3 is the primary sperm receptor while ZP2 has secondary sperm receptor properties. In the pig, however, ZP1 has been shown to have sperm receptor activity similar to that observed in the rabbit and nonhuman primates. It is of interest that the human ZP2 and ZP3 gene families are 60-70% conserved with respect to the mouse ZP amino acid sequence, while the mouse ZP1 is only 39% conserved with respect to human ZP1. Such differences in protein structure and glysosylation may explain the marked species differences in the biochemical, physicochemical and immunochemical properties of the ZP. Studies have now shown that the proteins of the ZP are expressed in a stage specific manner and that there is increasing evidence that ZP proteins are expressed by both granulosa cells and the oocyte and may play a role in granulosa cell differentiation.

Thin basement membrane disease with heavy proteinuria or nephrotic syndrome at presentation

Thin basement membrane disease (TBMD) is a condition originally defined as diffuse thinning of the glomerular basement membrane (GBM) associated with hematuria in all patients. Although proteinuria has been described in up to 60% of patients with TBMD, it is almost always mild, with a 24-hour excretion mostly of less than 500 mg. We describe eight patients (four men and four women between 32 and 66 years of age) with TBMD who presented with heavy proteinuria or nephrotic syndrome. Among the seven cases with family history, hematuria was noted in five. All patients had a long history of microscopic hematuria, with episodic gross hematuria in two. Renal biopsies showed diffuse thinning of the GBM in each patient (mean between 185.3 x 29.8 nm and 232.6 x 34.5 nm versus control between 325 x 35 nm and 350 x 15 nm). Three cases showed thinning of GBM only (group I); the remaining five cases showed thinning of GBM associated with focal segmental glomerulosclerosis. All three patients of group I presented with nephrotic syndrome and normal renal function. Treatment with steroids resulted in remission of nephrotic syndrome in two, whereas nephrotic syndrome persisted in the untreated patient. Among the five patients in group II, nephrotic syndrome and normal renal function at presentation were noted in two, whereas the other three had heavy proteinuria (2.2, 2. 5, and 2.6 g/d, respectively) associated with mildly decreased renal function (serum creatinine 1.8, 1.3, and 1.5 mg/dL, respectively). At last follow-up, although the renal function was stable in all five, only the three who received steroid treatment had remission or marked improvement of proteinuria. Hematuria, however, persisted in all eight patients of both groups. Whether specific gene mutations are translated into structural changes responsible for both excessive GBM thinning and increased transcapillary permeability remains to be elucidated. Alternatively, the heavy proteinuria/nephrotic syndrome may not be related to TBMD, but rather is the manifestation of associated glomerular diseases. Follow-up, including a response to steroids, supports the latter hypothesis.

Mucopolysaccharidosis presenting as pediatric multiple aortic aneurysm: first reported case

Within the pediatric population, the rare aortic aneurysm is most often brought on by congenital cardiovascular malformation or connective tissue disorder, trauma, inflammatory disease, or infection. Thus our 8-year-old patient who had multiple aortic aneurysms and evidence of mucopolysaccharidosis presented a doubly unique case. Three and one-half months after the patient underwent emergency aortic valve replacement, we performed resection and graft replacement of both her descending thoracic aorta and thoracoabdominal aorta. Histologic analysis of the aneurysm wall displayed severe medial degeneration with large deposits of acid mucopolysaccharides. Subsequent evaluation, although negative for connective tissue disorders, showed glycosaminoglycans, chondroitin sulfate, and heparan sulfate in the patient's urine. These findings are diagnostic for a heterogeneous group of storage diseases termed mucopolysaccharidoses, although testing of the patient's cultured fibroblasts failed to reveal any specific previously described enzymatic defect. After reviewing the literature, we believe that this is the first known successfully treated pediatric aortic aneurysm associated with mucopolysaccharidosis.

Inhibitory effects of hypercholesterolemia and ox-LDL on angiogenesis-like endothelial growth in rabbit aortic explants. Essential role of basic fibroblast growth factor

Hypercholesterolemic (HC) rabbits exhibit suppressed compensatory vascular growth after restriction of arterial supply. However, neovascularization is commonly found in atheromas containing inflammatory cells. We used an in vitro model to determine the effects of hypercholesterolemia on angiogenesis in the absence or presence of inflammatory cells. HC rabbit aortic explants (1 mm2) with or without (n = 90 each) lesion-forming inflammatory cells were cultured in a collagen matrix with serum-free medium. Explant-derived endothelial cell growth was organized into capillary-like microtubes (CLM) that could be videomicroscopically quantified. CLM growth from lesion-free HC explants was significantly reduced to 13 +/- 4% of the value in explants (n = 90) from normocholesterolemic (NC, n = 15) rabbits (P < .001). In contrast, in lesion-containing HC explants, the matrix was invaded by foam cells, and CLM growth was not inhibited. Immunoassayable basic fibroblast growth factor (bFGF, in pg/mL) in the culture medium was significantly lower in lesion-free HC (< 5) than NC explants (11 +/- 2, P < .01) or HC explants with lesions (14 +/- 3). In addition, CLM growth was reduced in NC explants incubated with oxidized LDL (ox-LDL, 50-100 micrograms/mL). Exogenous bFGF (10 ng/mL) reversed the inhibitory effects of hypercholesterolemia and ox-LDL, whereas bFGF-neutralizing antibody (10 micrograms/mL) abolished CLM growth in all groups. In cultured rabbit aortic endothelial cells, ox-LDL reduced DNA synthesis, but this inhibition was reversed by bFGF. We conclude that hypercholesterolemia and ox-LDL inhibit angiogenesis like endothelial growth because of a suppressed availability of endogenous bFGF. Retained responsiveness to exogenous bFGF suggests that inducing bFGF expression at targeted sites may improve collateral growth in hyperlipidemic arterial disease.

Intraluminal crystalloids in breast carcinoma. Immunohistochemical, ultrastructural, and energy-dispersive x-ray element analysis in four cases

OBJECTIVE

Intraluminal crystalloids have been described in the prostate, salivary gland, and ovary, but have not yet been reported in the breast. We report four cases of breast carcinoma in which these crystalloids were found in ducts with intraductal carcinoma or atypical hyperplasia. The presence of intraluminal crystalloids may be a useful adjunct in making a diagnosis of carcinoma or may be a feature to look for as a marker for the presence of carcinoma.

DESIGN

Four cases of breast carcinoma containing intraluminal crystalloids were identified among 6900 surgical breast specimens between January 1990 and June 1995 at M. D. Anderson Cancer Center, Houston, Tex. Those sections with crystalloids identified by hematoxylin-eosin stain were stained with periodic acid-Schiff, Alcian blue, and mucicarmine stains. Immunohistochemical and ultrastructural studies and energy-dispersive x-ray analysis were also performed on these sections.

RESULTS

The intraluminal crystalloids were eosinophilic, varied in shape and size, and did not exhibit birefringence under polarized light. Immunohistochemically, the crystalloids were negative for keratin, muscle-specific actin, and kappa and lambda light chains, but the surfaces stained positively for epithelial membrane antigen. By electron microscopy, the crystalloids had no limiting membrane and were composed of an electron-dense material with no discernible periodicity. By energy-dispersive x-ray element analysis, the crystalloids had no mineral content; however, sulfur was found, indicating a protein content.

CONCLUSIONS

The pathogenesis and constituents of these intraluminal crystalloids remain to be determined. Inasmuch as intraluminal crystalloids have not been found in normal ducts or acini, or in ductal hyperplasia without atypia, their presence may serve as a marker for breast carcinoma.

An assessment of the routes of incorporation of opiates into beard hair after a single oral dose of codeine

The time course of appearance of immunoreactive opiates was monitored in saliva, sweat, and beard hair in six healthy whites who were not opiate users after oral administration of 60 mg of codeine phosphate. The opiate concentration in saliva peaked within 30 min of drug administration and returned to near the predose level within 24 h. Ninety-one percent of the total secretion of opiates in sweat was collected by the skin-collection patch worn during the first 24 h after drug administration. Detectable material was also present in sweat patches on the following 2 days. Opiates were detected in extracts of alkali digests of beard hair in all subjects on the day after drug administration. Hair concentration peaked on day 3 after dosing and then decreased continuously until day 8. From day 8 until the end of the experiment on day 14, beard hair contained opiate concentrations significantly greater than the predose level. From comparison with cotinine pharmacokinetics, it is proposed that an early and the largest transfer of opiates into beard hair is through sweat. Transfer during hair growth is secondary and of comparable importance to a newly identified contribution of long duration that may involve transfer from storage depots within skin.

Neurodegeneration, myocardial injury, and perinatal death in mitochondrial superoxide dismutase-deficient mice

Manganese superoxide dismutase (SOD2) converts superoxide to oxygen plus hydrogen peroxide and serves as the primary defense against mitochondrial superoxide. Impaired SOD2 activity in humans has been associated with several chronic diseases, including ovarian cancer and type I diabetes, and SOD2 overexpression appears to suppress malignancy in cultured cells. We have produced a line of SOD2 knockout mice (SOD2m1BCM/SOD2m1BCM) that survive up to 3 weeks of age and exhibit several novel pathologic phenotypes including severe anemia, degeneration of neurons in the basal ganglia and brainstem, and progressive motor disturbances characterized by weakness, rapid fatigue, and circling behavior. In addition, SOD2m1BCM/SOD2m1BCM mice older than 7 days exhibit extensive mitochondrial injury within degenerating neurons and cardiac myocytes. Approximately 10% of SOD2m1BCM/SOD2m1BCM mice exhibit markedly enlarged and dilated hearts. These observations indicate that SOD2 deficiency causes increased susceptibility to oxidative mitochondrial injury in central nervous system neurons, cardiac myocytes, and other metabolically active tissues after postnatal exposure to ambient oxygen concentrations. Our SOD2-deficient mice differ from a recently described model in which homozygotes die within the first 5 days of life with severe cardiomyopathy and do not exhibit motor disturbances, central nervous system injury, or ultrastructural evidence of mitochondrial injury.

Pelvic lymph node histiocytosis mimicking metastatic prostatic adenocarcinoma: association with hip prostheses

PURPOSE

Histological changes in lymph nodes simulating metastatic prostatic adenocarcinoma are reported.

MATERIALS AND METHODS

Lymph node frozen sections from 3 patients with prostatic cancer displayed marked histiocytosis. This tissue was subjected to histochemical, immunohistochemical and electron microscopic studies.

RESULTS

Only 1 erroneous diagnosis of metastasis was made. All patients had hip prostheses for at least 6 years. Tissue replacing up to 80% of lymph nodes consisted of histiocytes containing large amounts of polyethylene.

CONCLUSIONS

Hip replacement predisposes the patient to have pelvic lymph node histiocytosis mimicking metastatic adenocarcinoma. This history should be communicated to the pathologist. Polyethylene is the most important factor in the cause of post-prosthesis lymph node histiocytosis.

Disruption of the adenosine deaminase gene causes hepatocellular impairment and perinatal lethality in mice

We have generated mice with a null mutation at the Ada locus, which encodes the purine catabolic enzyme adenosine deaminase (ADA, EC 3.5.4.4). ADA-deficient fetuses exhibited hepatocellular impairment and died perinatally. Their lymphoid tissues were not largely affected. Accumulation of ADA substrates was detectable in ADA-deficient conceptuses as early as 12.5 days postcoitum, dramatically increasing during late in utero development, and is the likely cause of liver damage and fetal death. The results presented here demonstrate that ADA is important for the homeostatic maintenance of purines in mice.

Long-term histopathologic changes in canine aneurysms embolized with Guglielmi detachable coils

PURPOSE

To evaluate the long-term histologic changes, including those in the ultrastructure of the neoendothelium, occurring in experimental canine aneurysms obliterated with Guglielmi detachable coils.

METHODS

Ten experimental aneurysms were surgically created in mongrel dogs using side-to-side jugular carotid fistulas that were subsequently ligated to form blind pouch venous aneurysms dependent on the carotid circulation. The aneurysms were obliterated with Guglielmi detachable coils, and the animals were kept in observation. Six months after the endovascular obliteration of the aneurysms, repeat carotid arteriography was performed to assess for potential recanalization of the aneurysms. The animals were then killed and submitted for autopsy. The carotid artery and the embolized aneurysm were resected and studied with light and electron microscopy.

RESULTS

Both completely obliterated and recanalized aneurysms were excluded from the parent circulation by an endothelialized layer of connective tissue. The fundus of the aneurysm was completely obliterated by heavy reactive fibrous tissue surrounding the coils with very minimal, if any, inflammatory reaction. The neointima is composed of three well-identifiable layers, the most superficial of which is formed of new endothelial cells positioned next to each other in a cobblestone fashion over a basal membrane.

CONCLUSION

In the absence of histologic data in human aneurysms obliterated with Guglielmi detachable coils, several observations made in our experimental study help in the understanding of the long-term results expected from this endovascular technique.

Effect of fibrous glass on rat pleural mesothelium. Histopathologic observations

Female Fisher 344 rats (n = 25) were inoculated intrapleurally with a single 20-mg dose of (JM-100) fibrous glass. The mean length (2.2 microns) and width (0.15 microns) of the fibrous glass particles was within respirable range. Following inoculation, the rats were killed at timed intervals ranging from 2 to 430 d from inoculation. The pleural histopathologic changes were independently observed by a panel of three pathologists blinded to the time elapsed from inoculation. Fibrous adhesions, nodular lesions, and grossly evident tumor were noted in 15, 2, and 1 rat, respectively. In 1 rat there were combined adhesive and nodular changes, and in 6 there were no grossly detectable abnormalities. Chronic inflammation, fibrosis, and foreign body reaction were found in 9, 18, and 10 rats, respectively. Mesothelial hyperplasia and dysplasia were observed in 16 and 9 rats, respectively. Of 16 rats with the severest degree of hyperplasia and dysplasia, 3 developed malignant mesothelioma. This study suggests that a spectrum of rat pleural mesothelial histopathologic changes occurs before development of mesothelioma. The association of severe dysplasia in 3 rats with fully developed mesothelioma suggests that there may be a gradual progression from mesothelial hyperplasia or dysplasia to mesothelioma. Multivariate analysis further suggests that gross pleural nodular lesions and dysplasia may be significantly associated with the development of mesothelioma in this experimental model.

Thymic nurse cells are sites of thymocyte apoptosis

Thymic stromal cells play important roles in thymocyte differentiation and selection. Thymic nurse cells (TNC) are thymic epithelial stromal cells that envelop two to 200 CD4+CD8+ thymocytes (TNC-T). The mechanism by which TNC complexes form and their role in thymocyte development are unknown. TNC have been implicated as specialized microenvironments for proliferation, positive selection, negative selection, and apoptosis. Using TCR-gamma junctional sequence analysis of thymocytes within individual TNC, eight of ten TNC analyzed were polyclonal, and two showed evidence of oligoclonality. TCR-alpha beta expression was not detectable on most TNC-T and SCID mice, which do not express TCRs because of a defect in TCR gene rearrangement, had normal numbers of thymocyte-bearing TNC. Thus, TCR expression is not necessary for TNC formation. Treatment of mice with Abs to CD3 epsilon, which induces apoptosis in immature thymocytes, resulted in an eightfold increase in TNC per thymus with 95.5% apoptotic TNC-T. These results suggest that a function of TNC is the clearance of nonfunctional, nonselected, apoptotic thymocytes.

Thymic nurse cells are sites of thymocyte apoptosis

Thymic stromal cells play important roles in thymocyte differentiation and selection. Thymic nurse cells (TNC) are thymic epithelial stromal cells that envelop two to 200 CD4+CD8+ thymocytes (TNC-T). The mechanism by which TNC complexes form and their role in thymocyte development are unknown. TNC have been implicated as specialized microenvironments for proliferation, positive selection, negative selection, and apoptosis. Using TCR-gamma junctional sequence analysis of thymocytes within individual TNC, eight of ten TNC analyzed were polyclonal, and two showed evidence of oligoclonality. TCR-alpha beta expression was not detectable on most TNC-T and SCID mice, which do not express TCRs because of a defect in TCR gene rearrangement, had normal numbers of thymocyte-bearing TNC. Thus, TCR expression is not necessary for TNC formation. Treatment of mice with Abs to CD3 epsilon, which induces apoptosis in immature thymocytes, resulted in an eightfold increase in TNC per thymus with 95.5% apoptotic TNC-T. These results suggest that a function of TNC is the clearance of nonfunctional, nonselected, apoptotic thymocytes.

Active site-blocked factor Xa prevents thrombus formation in the coronary vasculature in parallel with inhibition of extravascular coagulation in a canine thrombosis model

Factor Xa is a central procoagulant enzyme, linking the intrinsic and extrinsic activation mechanisms to the final common pathway of coagulation. To assess its contribution to pathologic thrombosis, studies were performed in a canine coronary thrombosis model. Thrombus formation was initiated by the application of electric current via a needle electrode placed in the lumen of the left circumflex coronary artery. When 50% occlusion of the vessel developed, the current was stopped and animals received an intravenous bolus of either saline, bovine glutamyl-glycinyl-arginyl-factor Xa (Xai), a competitive inhibitor of factor Xa assembly into the prothrombinase complex, Factor X, or heparin. Animals infused with saline or factor X (300 micrograms/kg) developed total occlusion of the vessel due to a fibrin/platelet thrombus in 70 +/- 11 minutes (36 of 36 animals) and 74 +/- 13 minutes (8 of 8 animals), respectively. In contrast, infusion of Xai prevented thrombus formation completely at a dose of 300 micrograms/kg (8 of 8 animals). As the dose of Xai was decreased, its antithrombotic effect was diminished, with a patency rate of only 2 of 6 animals at a dose of 90 micrograms/kg. Xai at 300 micrograms/kg prevented the accumulation of 125I-fibrinogen/fibrin at the site of the coronary thrombus by approximately 63% and decreased deposition of 111In-labeled platelets by approximately 57%. Hemostatic parameters of animals infused with Xai demonstrated prolongation of the PT and dose-dependent increased extravascular bleeding tendency. These data indicate that factor Xa has a comparably important role in thrombus formation and extravascular hemostasis, and contrast with previous results in this same animal model in which IXai selectively prevented clotting in the coronary vasculature.

Amiodarone pulmonary toxicity: a multidisciplinary review of current status

Amiodarone, a benzofuran derivative, has proven useful in the control of serious cardiac arrhythmias. We reviewed the English language medical literature to characterize clinical, radiographic, scintigraphic, pathologic, diagnostic, and prognostic data concerning amiodarone pulmonary toxicity. Our review showed that features consistent with amiodarone pulmonary toxicity include exertional dyspnea, fever, and high sedimentation rates, usually in patients taking larger maintenance doses. Positive findings on gallium scan, foamy alveolar macrophages on lung biopsy or bronchoalveolar lavage, and resolution of abnormal chest roentgenogram upon withdrawal of amiodarone and/or institution of corticosteroid therapy support a diagnosis of amiodarone pulmonary toxicity. Conversely, maintenance doses of 400 mg or less daily, normal lung diffusing capacity and bronchoalveolar lavage or lung biopsy specimens without foamy alveolar macrophages are features that make amiodarone pulmonary toxicity unlikely. Amiodarone pulmonary toxicity should be considered in any patient who has new or clinical worsening of respiratory symptoms and/or abnormalities on chest roentgenogram. Congestive heart failure is often present in these patients and must be excluded before a diagnosis of amiodarone pulmonary toxicity can be considered. Amiodarone pulmonary toxicity also needs to be distinguished from pulmonary infection. Therefore, amiodarone pulmonary toxicity remains a clinical diagnosis relying upon a composite of clinical, radiographic, and histopathologic findings.

Calcium oxalate in breast lesions biopsied for calcification detected in screening mammography: incidence and clinical significance

Two types of calcification have been reported in breast tissue: one appears as dark-blue deposits in routine histologic tissue sections and has been found to be composed mostly of calcium phosphate (CaP); the other is colorless and represents calcium oxalate (CaOx). CaP has been well characterized, but little is known about CaOx. The presence of CaOx was evaluated in 91 breast lesions (71 retrospective and 20 prospective cases) biopsied for the presence of calcification in screening mammography. CaOx was found in 36 cases (39%). CaOx is usually not clearly visible in routine histologic sections. CaOx is found as refractile, strongly birefringent crystals with characteristic morphology. CaOx was present only within benign lesions which frequently showed apocrine metaplasia. However, the breast tissue away from the areas with CaOx displayed a morphologic spectrum roughly similar to that in cases with CaP only. CaOx was clinically significant, i.e., actually represented the mammographic calcification, for which the biopsy was performed in 12% (11/91) of all cases studied and in 31% (11/36) of cases in which CaOx was found. In the cases where CaOx was not considered clinically significant, it was either not radiographically visible or, if visible, did not definitely represent the mammographic calcification for which the biopsy was performed. Since CaOx in breast biopsies is often clinically significant, and since CaOx is not clearly visible in routine sections, examination under polarized light is suggested for all breast biopsies removed for mammographic calcification, particularly when CaP deposits corresponding to the mammographic calcification are not apparent.