Magnetic implants in the tongue for assistive technologies: Tests of migration; oromotor function; and tissue response in miniature pigs.

OBJECTIVE: Uncertain biological consequences of titanium-magnet (Ti-mag) tongue implants constrain application of the Tongue Drive System (TDS), a brain-tongue-computer interface for individuals with severe physical impairment. Here we describe oromotor function and tongue tissue response following Ti-Mag implantation and explantation in the miniature pig, an animal model with a tongue similar in size to humans. DESIGN: A 1.8×6.2mm Ti-mag tracer was implanted into the anterior tongue in five Yucatan minipigs. X-rays were taken immediately and >six days after implantation to evaluate tracer migration. In three minipigs, the tracer was explanted >16days after implantation. Twenty-five days post-explantation, tongue tissue was harvested and processed for histological and immunohistochemical (IHC) markers of healing. In two minipigs tissue markers of healing were evaluated post-mortem following >12days implantation. Drink cycle rate (DCR) was characterized to determine the impact of procedures on oromotor function. RESULTS: Neither implantation (N=5) nor explantation (N=3) changed DCR. X-rays revealed minimal tracer migration (N=4, 0-4mm). By histology and IHC a robust capsule was present two weeks post-implantation with limited fibrosis. Explantation produced localized fibrosis and limited muscle remodeling. CONCLUSIONS: These findings suggest the safety of Ti-mag anterior tongue implants for assistive technologies in humans.

Observation of the seleno bis-(S-glutathionyl) arsinium anion in rat bile.

Certain arsenic and selenium compounds show a remarkable mutual cancelation of toxicities, where a lethal dose of one can be voided by an equimolar and otherwise lethal dose of the other. It is now well established that the molecular basis of this antagonism is the formation and biliary excretion of seleno bis-(S-glutathionyl) arsinium anion [(GS)2AsSe](-). Previous work has definitively demonstrated the presence of [(GS)2AsSe](-) in rabbit bile, but only in the presence of other arsenic and selenium species. Rabbits have a gall bladder, which concentrates bile and lowers its pH; it seems likely that this may be responsible for the breakdown of biliary [(GS)2AsSe](-). Since rats have no gall bladder, the bile proceeds directly through the bile duct from the hepatobiliary tree. In the present work we have shown that the primary product of biliary co-excretion of arsenic and selenium in rats is [(GS)2AsSe](-), with essentially 100% of the arsenic and selenium present as this species. The chemical plausibility of the X-ray absorption spectroscopy-derived structural conclusions of this novel arsenic and selenium co-excretion product is supported by density functional theory calculations. These results establish the biomolecular basis to further explore the use of selenium dietary supplements as a possible palliative for chronic low-level arsenic poisoning of human populations.

Whole-body immunoPET reveals active SIV dynamics in viremic and antiretroviral therapy-treated macaques.

The detection of viral dynamics and localization in the context of controlled HIV infection remains a challenge and is limited to blood and biopsies. We developed a method to capture total-body simian immunodeficiency virus (SIV) replication using immunoPET (antibody-targeted positron emission tomography). The administration of a poly(ethylene glycol)-modified, (64)Cu-labeled SIV Gp120-specific antibody led to readily detectable signals in the gastrointestinal and respiratory tract, lymphoid tissues and reproductive organs of viremic monkeys. Viral signals were reduced in aviremic antiretroviral-treated monkeys but detectable in colon, select lymph nodes, small bowel, nasal turbinates, the genital tract and lung. In elite controllers, virus was detected primarily in foci in the small bowel, select lymphoid areas and the male reproductive tract, as confirmed by quantitative reverse-transcription PCR (qRT-PCR) and immunohistochemistry. This real-time, in vivo viral imaging method has broad applications to the study of immunodeficiency virus pathogenesis, drug and vaccine development, and the potential for clinical translation.

Retrograde ejaculation associated spontaneous sperm cystolithiasis in four rhesus macaques (Macaca mulatta).

Retrograde ejaculation (RE) has been reported in humans and animals but RE with subsequent sperm calculi has rarely been reported. This report documents clinical and pathological findings of spontaneous sperm cystolithiasis in four rhesus macaques. While this condition has been associated with repeated electroejaculation, spontaneous sperm cystolithiasis is highly unusual. The animals presented with either stranguria, dysuria, hematuria, distended abdomen or lethargy. Ultrasound examination revealed several hyperechoic masses within the lumen of the urinary bladder. The animals were euthanized due to poor prognosis or study end points. Postmortem examination revealed multiple angular, amorphous, soft to firm, pale yellow to greenish-brown and variably sized calculi in the lumen of the urinary bladder or prostatic/penile urethra. Histologically, the calculi were composed of numerous sperm embedded in abundant brightly eosinophilic matrix. Based on gross and histologic findings, RE associated sperm cystolithiasis was diagnosed, with ulcerative urethritis as the major primary apparent etiology. To the authors' knowledge, this is the first report of four spontaneous cases of sperm cystolithiasis in rhesus macaques.

Osteochondromatosis in a Rhesus macaque (Macaca mulatta).

A 5-y-old, male, rhesus macaque (Macaca mulatta) presented with a prominent mass slightly anteriomedial to the right stifle. On exam, multiple radiopaque masses were identified protruding from the mid- and distal femur. Lateral and anteroposterior radiographs of the right stifle region revealed multiple exophytic masses arising from the femur, with mild bony reaction of the proximal tibia. Histologic examination of biopsy tissue revealed woven and lamellar bone with granulation tissue and skeletal muscle. Because the macaque was exhibiting no lameness or signs of pain, we decided to monitor the progression of the masses. Minimal change was noted during the time prior to study termination at 6.5 y of age. Necropsy revealed that the bony masses were cartilage-capped lesions arising near the growth plate of the distal femur and midshaft of the femur and tibia. Histologic examination revealed chondro-osseous exophytic growths that blended imperceptibly with the cortex and spongiosa of the femur, consistent with a final diagnosis of multiple osteochondromas.

Chronic, constant-rate, gastric drug infusion in nontethered rhesus macaques (Macaca mulatta).

As part of a study of antipsychotic drug treatment in monkeys, we developed a technique to provide chronic, constant-rate, gastric drug infusion in nontethered rhesus macaques. This method allowed us to mimic the osmotic release oral delivery system currently used in humans for continuous enteral drug delivery. Rhesus macaques (n = 5) underwent gastric catheter placement by laparotomy. After the catheters were secured to the stomach, the remaining catheter length was exited through the lateral abdomen, tunneled subcutaneously along the back, and connected to a 2-mL osmotic pump enclosed in a subcutaneous pocket. Osmotic pumps were changed every 2 to 4 wk for 1 y and remained patent for the duration of the study. Four complications (including cutting of the catheter, incisional dehiscence at the pump site, and loss of 1 catheter into the abdominal cavity requiring catheter replacement) occurred among the 80 pump changes performed during the year-long study. At necropsy, histopathologic examination of the catheter implant sites revealed mild changes consistent with a foreign-body reaction. Our results indicate that the gastric catheter and osmotic pump system was well tolerated in rhesus macaques for as long as 12 mo after placement and suggest that this system will be an attractive option for use in studies that require chronic, constant-rate, gastric drug infusion in nontethered monkeys.

Suppression of NF-kappaB activation blocks osteoclastic bone resorption during estrogen deficiency.

Postmenopausal osteoporosis stems from an imbalance in osteoclastic bone resorption with respect to osteoblastic bone formation, a consequence of estrogen deficiency. The nuclear factor-kappaB (NF-kappaB) signal transduction pathway is critical for osteoclast formation and resorption, and suppression of NF-kappaB activation has been shown to block bone resorption in vitro, and to ameliorate inflammatory bone loss in vivo. The use of NF-kappaB antagonists to blunt the bone loss associated with estrogen deficiency however, has not been previously reported. In this study, we investigated whether pharmacological suppression of NF-kappaB signaling protects mice against ovariectomy (ovx)-induced bone loss. Ovx mice were treated with the potent NF-kappaB inhibitor pyrrolidine dithiocarbamate (PDTC) for 4 weeks and bone mineral density (BMD) and indices of bone structure quantitated by dual-energy X-ray absorptiometry (DXA), and micro-computed tomography (microCT). In vivo indices of bone resorption were quantitated in mouse serum using the biochemical marker C-terminal telopeptide of collagen (CTx). Our data revealed that NF-kappaB suppression significantly prevented ovx-induced bone destruction by preventing the increase in ovx-induced osteoclastic bone resorption. Our data suggest that NF-kappaB inhibitors may represent novel anticatabolic therapeutic agents for the amelioration of postmenopausal bone loss.

Infectious canine hepatitis in a gray fox (Urocyon cinereoargenteus).

A free-ranging adult male gray fox (Urocyon cinereoargenteus) with moderate diarrhea and thick ocular mucus discharge was examined postmortem. Microscopically, the fox had intranuclear inclusion bodies within hepatocytes. Canine adenovirus-1 was identified by polymerase chain reaction (PCR) and nucleotide sequencing. To our knowledge, this is the first report of clinical infectious canine hepatitis in a gray fox.

Endogenous TNFalpha lowers maximum peak bone mass and inhibits osteoblastic Smad activation through NF-kappaB.

UNLABELLED: Endogenous TNFalpha prevents the attainment of maximum achievable peak bone mass in vivo. In vitro, TNFalpha suppresses BMP-2- and TGFbeta-mediated Smad activation through induction of NF-kappaB. Consistently, pharmacological suppression of NF-kappaB augments osteoblast differentiation and mineralization in vitro. INTRODUCTION: Osteoporosis is a major health threat. Traditional therapeutic strategies have centered on anti-catabolic drugs that block bone resorption. Recently focus has shifted to anabolic agents that actively rebuild lost bone mass. Future strategies may involve elevating peak bone mass to delay osteoporosis development. Recent in vitro studies show that TNFalpha represses osteoblast differentiation and mineralization; however, the mechanisms are poorly understood and the impact of basal TNFalpha concentrations on the acquisition of peak bone mass in vivo is unknown. MATERIALS AND METHODS: We examined peak BMD, bone volume, and bone turnover makers in mice deficient in TNFalpha or its receptors. We further examined the effect of TNFalpha on Smad-induced signaling by TGFbeta and BMP-2 in vitro using a Smad responsive reporter. The effect of TNFalpha-induced NF-kappaB signaling on Smad signaling and on in vitro osteoblast mineralization was examined using specific NF-kappaB inhibitors and activators, and effects of TNFalpha-induced NF-kappaB signaling on BMP-2-induced Runx2 mRNA were examined using RT-PCR. RESULTS: Mice null for TNFalpha or its p55 receptor had significantly increased peak bone mass, resulting exclusively from elevated bone formation. In vitro, TNFalpha potently suppressed Smad signaling induced by TGFbeta and BMP-2, downregulated BMP-2-mediated Runx2 expression, and inhibited mineralization of osteoblasts. These effects were mimicked by overexpression of NF-kappaB and prevented by pharmacological NF-kappaB suppression. CONCLUSIONS: Our data suggest that TNFalpha and NF-kappaB antagonists may represent novel anabolic agents for the maximization of peak basal bone mass and/or the amelioration of pathological bone loss.