The effects of dog breed development on genetic diversity and the relative influences of performance and conformation breeding

Genetic diversity was compared among eight dog breeds selected primarily for conformation (Standard Poodle, Italian Greyhound and show English Setter), conformation and performance (Brittany), predominantly performance (German Shorthaired and Wirehaired Pointers) or solely performance (field English Setter and Red Setter). Modern village dogs, which better reflect ancestral genetic diversity, were used as the standard. Four to seven maternal and one to two Y haplotypes were found per breed, with one usually dominant. Diversity of maternal haplotypes was greatest in village dogs, intermediate in performance breeds and lowest in conformation breeds. Maternal haplotype sharing occurred across all breeds, while Y haplotypes were more breed specific. Almost all paternal haplotypes were identified among village dogs, with the exception of the dominant Y haplotype in Brittanys, which has not been identified heretofore. The highest heterozygosity based on 24 autosomal microsatellites was found in village dogs and the lowest in conformation (show) breeds. Principal coordinate analysis indicated that conformation-type breeds were distinct from breeds heavily used for performance, the latter clustering more closely with village dogs. The Brittany, a well-established dual show and field breed, was also genetically intermediate between the conformation and performance breeds. The number of DLA-DRB1 alleles varied from 3 to 10 per breed with extensive sharing. SNPs across the wider DLA region were more frequently homozygous in all pure breeds than in village dogs. Compared with their village dog relatives, all modern breed dogs exhibit reduced genetic diversity. Genetic diversity was even more reduced among breeds under selection for show/conformation.

Biochemical composition of human peripheral arteries examined with near-infrared Raman spectroscopy

PURPOSE

Near-infrared Raman spectroscopy provides an important new means of analyzing the chemical composition of the arterial wall. The objective of this study was to show that Raman spectroscopy can be used to evaluate the lipid and calcium salt contents of human peripheral arteries. The results extend a recently developed Raman-based method for analyzing the chemical composition of coronary arteries.

METHODS AND RESULTS

We studied 167 segments of carotid and femoral artery wall in various pathologic states. The Raman spectra from these samples was accurately modeled. The resulting chemical concentrations were compared with the amounts of cholesterol and calcium mineral determined at histologic evaluation by an experienced cardiovascular pathologist. Strong correlations between spectroscopic measurements and morphologic findings were demonstrated and validated the applicability of the method to peripheral arteries.

CONCLUSIONS

Raman spectroscopy can provide reliable histochemical information about peripheral and coronary arteries. Such information may help identify rupture-prone plaques before the onset of symptoms and allow aggressive and directed intervention. Accurate knowledge of the chemical composition of a lesion may be useful in selecting the most appropriate treatment.

People with Down's syndrome can be distinguished on the basis of cholinergic dysfunction

The mydriatic response to eyedrops of the anticholinergic agent tropicamide at very low concentration (0.01%) has been studied in people with Down's syndrome. By comparison with healthy subjects people with Down's syndrome had responses approximately three times greater, suggesting a peripheral imbalance between cholinergic and adrenergic autonomic influences.

Parathyroid localization, three-dimensional modeling, and percutaneous ablation techniques

When available, state of the art noninvasive localization studies should be utilized routinely in previously unexplored patients for localizing parathyroid pathology, even when exceptional surgical experience exists. These studies can both minimize the 3 to 20% incidence of missed pathology and promote an approach of limited neck exploration with consequent lowering of morbidity, complications, and costs. Choice of imaging modalities for localizing these small masses is largely dependent on the level of state of the art of available equipment, the interest and experience of the performing physicians, and the attention to technical detail for each of the modalities at an individual institution. In choosing a single test, CT, and most recently cine CT with three-dimensional modeling, is favored because of higher probability of providing the kinds of information most useful to the surgeon. This includes precise anatomic localization and identification of locations likely to be missed by the surgeon (such as mediastinum, deep neck) and the capability for predicting multiple gland disease, for detecting smaller lesions, and for lower incidence of false-positive results. Ultrasound is attractive because of the low cost and noninvasiveness, and it is particularly sensitive in the thyroid region and upper neck. In difficult cases, CT, cine CT, and ultrasound may be augmented by needle aspiration of fluid for PTH assay. Thallium-technetium scanning and MRI are useful alternatives. In the previously explored patient and in patients with difficult diagnostic problems (such as ectopic adenoma, parathyroid carcinoma), the use of multiple noninvasive studies is strongly recommended, preferably CT (particularly, cine CT with three-dimensional imaging) and isotope scanning or MRI. The concurrence of two or more of these studies has a relatively high predictive value (82 to 88%) for localization. However, highly selective venous catheterization and selective magnification arteriography remain the most accurate modalities in these patients (91 to 95% sensitivity with few false-positive results) and may be combined with interventional radiologic techniques for tumor ablation in selected patients without compromising subsequent surgical alternatives. Stereotactic ablation techniques are in development.

The effect of cyclosporin A (CsA) treatment on gingival tissue of patients with Behçet's disease

Gingival biopsies were obtained at various intervals for a period of two years from 12 patients suffering from Behçet's disease who were under a clinical trial of cyclosporin A (CsA) treatment. The levels of nondialyzable hydroxyproline (Hypro) were determined in the medium of the cultured tissues. Histologic examinations were also performed every three months. Correlations between the CsA blood levels and the levels of nondialyzable Hypro indicated a reciprocal relationship, especially at blood levels of CsA higher than 600 ng/ml. Histologic examination of gingival sections from CsA-treated patients showed swelling of the epithelial cells, formation of perinuclear clear zones, widening of intercellular gaps and formation of several basal cell layers. In addition, foci of PAS-positive material were found in both the epithelium and stroma. It is assumed that the gingival enlargement observed in the CsA-treated patients was not due to an increase in tissue collagen but rather to an increase in epithelium combined with an accumulation of noncollagenous extracellular matrix material.

An evaluation of 99mTc-labeled red blood cell scintigraphy for the detection and localization of gastrointestinal bleeding sites

99mTechnetium-labeled red blood cell scintigraphy was performed upon 39 patients with clinical evidence for acute lower gastrointestinal bleeding from an unknown source. Seventeen of 39 patients (44%) had a scan became positive 6 or more h after injection, consistent with intermittent bleeding, in 8 of 17 patients (47%). In the 11 patients in whom the bleeding site was definitely identified by arteriography, surgery, or colonoscopy, scintigraphy correctly localized the bleeding site in 10 of 11 patients (91%). Four of 11 patients (36%) had an active bleeding site identified by arteriography. Ten of 17 patients (58%) with a positive scan required either gelfoam embolization (4 patients) or surgery (6 patients) to control the bleeding, whereas only 1 of 22 patients (5%) required surgery when the scan was negative. Six deaths occurred in the scan-positive patients compared with no deaths in the scan-negative patients. None of the 8 patients who had arteriography and no active bleeding site by scintigraphy had arteriographically demonstrable active bleeding. Scintigraphy provides a reliable noninvasive test to screen patients in whom arteriography is being considered to localize active bleeding sites. If the arteriogram is negative, the scintigraphic findings alone may guide the surgical or arteriographic intervention. In addition, scintigraphy identifies two patient populations which have considerably different morbidity and mortality.

Retrograde flow in the left gonadal vein at abdominal angiography: an anatomo-physiological review and clinical assessment

Retrograde flow in the left gonadal vein may be visualized in the venous phase of aortography or renal arteriography. In none of 13 cases was this due to a mass lesion at the renal hilum. Although the Valsalva maneuver may cause this flow reversal in some, in most cases it is due to anatomical structures or variants compressing the renal vein. These are detailed. Left gonadal vein reflux incidentally detected on the aortogram may thus indicate impaired left renal venous drainage and its consequences. There are also clinical and urographic constellations which merit aortography to detect left gonadal vein reflux for their elucidation.

Ultrasonic visualization of the posterior thoracic aorta in long axis: diagnosis of a saccular mycotic aneurysm

A saccular aneurysm arising from the descending thoracic aorta was identified ultrasonically in a 60-year-old man with a subsequent pathologic diagnosis of a Listeria monocytogenes mycotic aneurysm. A cross-sectional scanning technique, which permitted visualization of the descending thoracic aorta in long axis, demonstrated a 3 X 5 cm relatively echo-free mass between the heart and the aorta. A communication between the mass and the aorta established the diagnosis of an aneurysm.

Echocardiographic diagnosis of left ventricular thrombi

Left ventricular thrombi have not been commonly recognized by M-mode or by cross-sectional echocardiographic techniques despite their frequency at postmortem examination in patients dying of cardiovascular disease. We discuss two patients, with left ventricular throbmi recognized echocardiographically and confirmed by pathologic and/or angiographic evaluation, whose M-mode and cross-sectional echocardiographic abnormalities add to the variable spectrum of appearance of left ventricularl thrombi. The sensitivity and specificity of echocardiographic techniques in the diagnosis of intracardiac thrombi are discussed.

Role of selective venous catheterization of the small thyroid veins as a diagnostic study in hypercalcemic states

Previous studies of selective venous catheterization stress its value in localizing hyperfunctioning parathyroid tissue in patients with an established diagnosis of hyperparathyroidism. Our study presents our experience with selective venous catheterization as a diagnostic aid in differential diagnosis of hypercalcemia. In our four patients, an extensive metabolic work-up did not resolve the differential diagnosis of hypercalcemia, and selective venous catheterization provided the ultimate data that led to the correct diagnosis of hypercalcemia in each patient. Selective venous catheterization can be an important diagnostic study in carefully selected patients with hypercalcemia.

Localization of bleeding small intestinal lesions using scanning techniques

Gastrointestinal bleeding remains a major diagnostic problem, and the commonly employed techniques of contrast radiography, endoscopy, and arteriography may not successfully localize the site and/or define the cause of gastrointestinal hemorrhage. Technetium-99m pertechnetate scanning has been useful in identifying Meckel's diverticula, and modifications of this technique may successfully identify highly vascular lesions responsible for gastrointestinal bleeding. A patient with recurrent hemorrhage from a leiomyosarcoma of the ileum is described. The lesion was identified with flow studies and immediate static imaging after injection of technetium-99m pertechnetate. In addition, the lesion was demonstrated by scanning using in vivo technetium-99m pertechnetate labelled autologous erythrocytes. The potential value of these scanning techniques as noninvasive tools for the localization and identification of lesions responsible for gastrointestinal bleeding is discussed.

Isolated mesenteric desmoids (mesenteric fibromatosis)

The so-called desmoid tumour is an important member of a group of conditions termed "the fibromatoses" which are characterised by an infiltrating fibroblastic proliferation without features of an inflammatory response. While desmoids most frequently arise in the anterior abdominal wall, they may also be extra-abdominal or intra-abdominal in location. Mesenteric desmoids are relatively rare. They may occur in association with Gardner's syndrome, especially following colectomy, or as an isolated abnormality in otherwise normal patients. In the present paper the authors describe the clinical, radiological and pathological findings in two patients with isolated mesenteric desmoids. The radiological differential diagnosis is also briefly discussed.