Factors influencing rat survival in a warm renal ischemia model: time to adapt the protocols

Introduction

Survival in warm renal ischemia models is not only dependent on the treatment or surgical technique being evaluated, but also on factors inherent to the model itself. Use of rats of various strains in previous studies makes interstudy comparison difficult when trying to design an appropriate model control that would yield intermediate survival. In this study, impact of rat strain on survival after prolonged warm renal ischemia in the setting of delivery-controlled inhalational anesthesia was evaluated.

Materials and methods

Under general delivery-controlled inhalation anesthesia with isoflurane, Dahl salt-sensitive, Wistar-Furth, Sprague-Dawley, and spontaneously hypertensive rats (n = 66 rats) were subjected to 150 minutes of unilateral renal warm ischemia time, subsequent reperfusion, and contralateral nephrectomy. Animals were followed up for 1 month, after which survivors were euthanized and morphologic changes in kidneys were scored.

Results

Thirty-day survival was: Dahl salt sensitive, 78%; Wistar-Furth, 67%; Sprague-Dawley, 55%; and spontaneously hypertensive rats, 0% (P < .0001). Histologic acute injury scores were higher for non-survivors versus 30-day survivors (P < .0001).

Conclusion

Our data strongly suggest that rat strain is a major factor influencing survival and that strain and warm ischemia time selections must be considered together when designing a model control yielding intermediate survival. Further study is warranted in order to compare the effect of delivery-controlled inhalational versus historical anesthesia methods on animal survival.     

In vivo targeting of acoustically reflective liposomes for intravascular and transvascular ultrasonic enhancement

OBJECTIVES: The purpose of this study was to target acoustically reflective liposomes to atherosclerotic plaques in vivo for ultrasound image enhancement. BACKGROUND: We have previously demonstrated the development of acoustically reflective liposomes that can be conjugated for site-specific acoustic enhancement. This study evaluates the ability of liposomes coupled to antibodies specific for different components of atherosclerotic plaques and thrombi to target and enhance ultrasonic images in vivo. METHODS: Liposomes were prepared with phospholipids and cholesterol using a dehydration/ rehydration method. Antibodies were thiolated for liposome conjugation with N-succinimidyl 3-(2-pyridyldithio) propionate resulting in a thioether linkage between the protein and the phospholipid. Liposomes were conjugated to antifibrinogen or anti-intercellular adhesion molecule-1 (anti-ICAM-1). In a Yucatan miniswine model, atherosclerosis was developed by crush injury of one carotid and one femoral artery and ingestion of a hypercholesterolemic diet. After full plaque development the arteries were imaged (20-MHz intravascular ultrasound catheter and 7.5-MHz transvascular linear probe) after injection of saline, unconjugated liposomes and antibody conjugated liposomes. RESULTS: Conjugated liposomes retained their acoustically reflective properties and provided ultrasonic image enhancement of their targeted structures. Liposomes conjugated to antifibrinogen attached to thrombi and fibrous portions of the atheroma, whereas liposomes conjugated to anti-ICAM-1 attached to early atheroma. CONCLUSIONS: Our data demonstrate that this novel acoustic agent can provide varying targeting with different antibodies with retention of intravascular and transvascular acoustic properties.     

Establishment of rules for interpreting ultraviolet autofluorescence microscopy images for noninvasive detection of Barrett's esophagus and dysplasia

The diagnostic potential of autofluorescence (AF) microscopy under ultraviolet (UV) excitation is explored using ex vivo human specimens. The aim is to establish optical patterns (the rules for interpretation) that correspond to normal and abnormal histologies of the esophagus, spanning from early benign modifications (Barrett's esophagus) to subsequent dysplastic change and progression toward carcinoma. This was achieved by developing an image library categorized by disease progression. We considered morphological changes of disease as they are compared with histological diagnosis of the pathological specimen, as well as control samples of normal esophagus, proximal stomach, and small intestine tissue. Our experimental results indicate that UV AF microscopy could provide real-time histological information for visualizing changes in tissue microstructure that are currently undetectable using conventional endoscopic methods.     

Cortical thickness of the cognitive control network in obesity and successful weight loss maintenance: a preliminary MRI study

Cortical thickness of the cognitive control network was contrasted between obese (OB), successful weight loss maintainers (SWLM), and lean individuals. OB individuals had significant thinning, most notably in the anterior cingulate and posterior parietal cortices. SWLM individuals exhibited trends towards thicker cortex than OB individuals, which may be important in future studies.     

Optical spectroscopy and imaging of the dentin-enamel junction in human third molars

A 351-nm laser excitation source was used to perform autofluorescence microscopy of dentin, enamel, and the dentin-enamel junction (DEJ) to obtain information regarding their morphology and spectral characteristics. The emission spectra of these calcified dental tissues were different from one another, and this enabled the DEJ to be imaged and dimensionalized. The DEJ displayed sharp and clearly delineated borders at both its enamel and dentin margins. The dentinal tubules and the enamel prisms appeared to terminate abruptly at the DEJ. The median DEJ width was 10 microm, ranging from 7 to 15 microm, and it did not appear to depend on intratooth position.     

Video-assisted thoracoscopic diaphragm plication using a running suture technique is durable and effective

Objective

Surgeons have hesitated to adopt minimally invasive diaphragm plication techniques because of technical limitations rendering the procedure cumbersome or leading to early failure or reduced efficacy. We sought to demonstrate efficacy and durability of our thoracoscopic plication technique using a single running suture.

Influence of nonsteroidal anti-inflammatory drugs on osseointegration

This paper reviews contemporary literature concerning the possible influence of nonsteroidal anti-inflammatory drugs (NSAIDs) on osseointegration. In vitro studies concerning the effect of NSAIDs on growth factors and bone-generating cells are the primary source of data pertaining to this issue because relatively few in vivo studies have been conducted. It is concluded that prescribing NSAIDs during the early postoperative period is likely not without negative effect, although any negative influence appears to be temporary and does not affect the final outcome of osseointegration.