A Comparative Study of the Pathology and Pathophysiology of Severe Malaria in a Non-Human Primate Model

With the rise in plasmodial drug resistance throughout the world, a dwindling arsenal of anti-malarials and a predilection for use of less than ideal murine models, the need for effective, applicable and established animal models through which to understand severe malarial disease and test potential treatments is becoming increasingly crucial. Plasmodium coatneyi was discovered in the Philippines in the early 1960s in Rhesus macaque monkeys and has been evaluated sporadically as a potential platform for comparative studies of Plasmodium falciparum induced severe and cerebral malaria in humans. Using 30 years worth of archival samples at the Armed Forces Research Institute of Medical Sciences in Bangkok, Thailand, compounded with data and material from a series of prospective experimental studies, the work in this thesis sought to fully characterize and describe the pathology and pathobiology of the P. coatneyi/Rhesus macaque model. This included a thorough examination of the parasite host interaction, clinical symptomology, hematology and clinical pathology, gross pathology, histopathology, immunohistochemistry, cerebrospinal fluid cytokine profiles, transmission and scanning electron microscopy and atomic force microscopy of the disease in 45 adult rhesus macaques. The study further compared P. coatneyi with existing P. falciparum infected human material maintained at the National University of Singapore’s Vivax laboratory and Oxford University’s Ultrastructural Morphology Group, Nuffield Division of Clinical Laboratory Sciences. The study culminated in a successful clinical drug trial which evaluated the efficacy of varying doses of methylene blue as a radical cure for malaria in this non-human primate model. In many ways, the model mirrors P. falciparum, however the benefit of this evaluation is that it highlights not only the similarities but also the divergences. The successful completion of this description of the pathology and pathobiology of the P. coatneyi/Rhesus macaque model of severe and cerebral malaria adds a complex but effective animal model to the armamentarium in the ongoing war against malaria

Intracytoplasmic Crystalline Inclusions in the Hepatocytes of an Antelope

This case report describes intracytoplasmic crystalline inclusions in the hepatocytes of a 13-year-old female Thomson's gazelle. Histologically, multifocal to coalescing areas of many hepatocytes contained large cytoplasmic vacuoles filled with pale eosinophilic homogeneous material and rare fine basophilic granules. Von Kossa staining showed the presence of calcium within cytoplasm, mainly in the inclusions, of hepatocytes. Transmission electron microscopy, scanning electron microscopy, energy dispersive X-rays analyses, and infrared spectroscopy on the liver showed the hepatocellular material consistent with protein and carbohydrate with secondary accumulation of calcium and phosphorus. It was concluded that crystalline inclusions may have been derived due to failure of normal physiological hepatocellular clearance associated with a severe chronic disease. To the authors' knowledge this is the first reported case of hepatocellular crystalline inclusions in an antelope

Hematological Changes as Prognostic Indicators of Survival: Similarities Between Gottingen Minipigs, Humans, and Other Large Animal Models

The animal efficacy rule addressing development of drugs for selected disease categories has pointed out the need to develop alternative large animal models. Based on this rule, the pathophysiology of the disease in the animal model must be well characterized and must reflect that in humans. So far, manifestations of the acute radiation syndrome (ARS) have been extensively studied only in two large animal models, the non-human primate (NHP) and the canine. We are evaluating the suitability of the minipig as an additional large animal model for development of radiation countermeasures. We have previously shown that the Gottingen minipig manifests hematopoietic ARS phases and symptoms similar to those observed in canines, NHPs, and humans.We establish here the LD50/30 dose (radiation dose at which 50% of the animals succumb within 30 days), and show that at this dose the time of nadir and the duration of cytopenia resemble those observed for NHP and canines, and mimic closely the kinetics of blood cell depletion and recovery in human patients with reversible hematopoietic damage (H3 category, METREPOL approach). No signs of GI damage in terms of diarrhea or shortening of villi were observed at doses up to 1.9 Gy. Platelet counts at days 10 and 14, number of days to reach critical platelet values, duration of thrombocytopenia, neutrophil stress response at 3 hours and count at 14 days, and CRP-to-platelet ratio were correlated with survival. The ratios between neutrophils, lymphocytes and platelets were significantly correlated with exposure to irradiation at different time intervals.As a non-rodent animal model, the minipig offers a useful alternative to NHP and canines, with attractive features including ARS resembling human ARS, cost, and regulatory acceptability. Use of the minipig may allow accelerated development of radiation countermeasures

Nonlesions, Misdiagnoses, Missed Diagnoses, and Other Interpretive Challenges in Fish Histopathology Studies: A Guide for Investigators, Authors, Reviewers, and Readers

Differentiating salient histopathologic changes from normal anatomic features or tissue artifacts can be decidedly challenging, especially for the novice fish pathologist. As a consequence, findings of questionable accuracy may be reported inadvertently, and the potential negative impacts of publishing inaccurate histopathologic interpretations are not always fully appreciated. The objectives of this article are to illustrate a number of specific morphologic findings in commonly examined fish tissues (e.g., gills, liver, kidney, and gonads) that are frequently either misdiagnosed or underdiagnosed, and to address related issues involving the interpretation of histopathologic data. To enhance the utility of this article as a guide, photomicrographs of normal and abnormal specimens are presented. General recommendations for generating and publishing results from histopathology studies are additionally provided. It is hoped that the furnished information will be a useful resource for manuscript generation, by helping authors, reviewers, and readers to critically assess fish histopathologic data.Keywords: misdiagnosis, fish histopathology, diagnostic accuracy, tissue fixation, artifacts, nonlesion

The Role of the Component Metals in the Toxicity of Military-Grade Tungsten Alloy

Tungsten-based composites have been recommended as a suitable replacement for depleted uranium. Unfortunately, one of these mixtures composed of tungsten (W), nickel (Ni) and cobalt (Co) induced rhabdomyosarcomas when implanted into the leg muscle of laboratory rats and mice to simulate a shrapnel wound. The question arose as to whether the neoplastic effect of the mixture could be solely attributed to one or more of the metal components. To investigate this possibility, pellets with one or two of the component metals replaced with an identical amount of the biologically-inert metal tantalum (Ta) were manufactured and implanted into the quadriceps of B6C3F1 mice. The mice were followed for two years to assess potential adverse health effects. Implantation with WTa, CoTa or WNiTa resulted in decreased survival, but not to the level reported for WNiCo. Sarcomas in the implanted muscle were found in 20% of the CoTa-implanted mice and 5% of the WTa- and WCoTa-implanted rats and mice, far below the 80% reported for WNiCo-implanted mice. The data obtained from this study suggested that no single metal is solely responsible for the neoplastic effects of WNiCo and that a synergistic effect of the three metals in tumor development was likely

Ultrasonic Thermal Damage during Robotic Hysterecomy

Application of energy in minimally invasive hysterectomy creates thermal injury which may increase vaginal cuff dehiscence. The purpose of this study was to compare vaginal tissue damage in a swine model between the two power settings of ultrasonic energy. This was an IACUC-approved, prospective, single-blinded study analyzing energy-induced damage to the swine vagina during robotic hysterectomy. Multiple colpotomy transections were performed on 18 animals using robotic ultrasonic energy, the exact same platform used in human surgery. Specimens (n = 72) were analyzed by a veterinary pathologist blinded to the energy source. Thermal injury was microscopically measured. Mean thermal injury (µm) was not statistically different between Max-Setting 5 and Min-Setting 3 (1243 ± 544 vs. 1293 ± 554; 95 % CI −310 to 210, p = 0.66). Time (s) to complete transection was significantly shorter when using Setting 5 (13.00 ± 7.75 vs. 17.92 ± 9.03; 95 % CI −4.92 to −8.88, p = 0.001). The rate of injury (µm/s) for Setting 5 also trended toward being higher (118.98 ± 72.81 vs. 93.03 ± 62.34; 95 % CI −5.91 to 57.81, p = 0.053). In these swine vaginal specimens, energy-induced tissue damage was not statistically different for the two ultrasonic power settings. Max-Setting 5 was faster and trended toward a higher rate of damage; this was balanced by equivalent distance of tissue injury compared with Min-Setting 3. In larger human specimens, the use of Max-Setting 5 may be recommended to decrease surgical time as it is faster and causes an equivalent amount of injury to Min-Setting 3

Ultrasonic Thermal Damage During Robotic Hysterectomy

Application of energy in minimally invasive hysterectomy creates thermal injury which may increase vaginal cuff dehiscence. The purpose of this study was to compare vaginal tissue damage in a swine model between the two power settings of ultrasonic energy. This was an IACUC-approved, prospective, single-blinded study analyzing energy-induced damage to the swine vagina during robotic hysterectomy. Multiple colpotomy transections were performed on 18 animals using robotic ultrasonic energy, the exact same platform used in human surgery. Specimens (n = 72) were analyzed by a veterinary pathologist blinded to the energy source. Thermal injury was microscopically measured. Mean thermal injury (µm) was not statistically different between Max-Setting 5 and Min-Setting 3 (1243 ± 544 vs. 1293 ± 554; 95 % CI −310 to 210, p = 0.66). Time (s) to complete transection was significantly shorter when using Setting 5 (13.00 ± 7.75 vs. 17.92 ± 9.03; 95 % CI −4.92 to −8.88, p = 0.001). The rate of injury (µm/s) for Setting 5 also trended toward being higher (118.98 ± 72.81 vs. 93.03 ± 62.34; 95 % CI −5.91 to 57.81, p = 0.053). In these swine vaginal specimens, energy-induced tissue damage was not statistically different for the two ultrasonic power settings. Max-Setting 5 was faster and trended toward a higher rate of damage; this was balanced by equivalent distance of tissue injury compared with Min-Setting 3. In larger human specimens, the use of Max-Setting 5 may be recommended to decrease surgical time as it is faster and causes an equivalent amount of injury to Min-Setting 3

Ultrasonic Thermal Damage during Robotic Hysterecomy

Application of energy in minimally invasive hysterectomy creates thermal injury which may increase vaginal cuff dehiscence. The purpose of this study was to compare vaginal tissue damage in a swine model between the two power settings of ultrasonic energy. This was an IACUC-approved, prospective, single-blinded study analyzing energy-induced damage to the swine vagina during robotic hysterectomy. Multiple colpotomy transections were performed on 18 animals using robotic ultrasonic energy, the exact same platform used in human surgery. Specimens (n = 72) were analyzed by a veterinary pathologist blinded to the energy source. Thermal injury was microscopically measured. Mean thermal injury (µm) was not statistically different between Max-Setting 5 and Min-Setting 3 (1243 ± 544 vs. 1293 ± 554; 95 % CI −310 to 210, p = 0.66). Time (s) to complete transection was significantly shorter when using Setting 5 (13.00 ± 7.75 vs. 17.92 ± 9.03; 95 % CI −4.92 to −8.88, p = 0.001). The rate of injury (µm/s) for Setting 5 also trended toward being higher (118.98 ± 72.81 vs. 93.03 ± 62.34; 95 % CI −5.91 to 57.81, p = 0.053). In these swine vaginal specimens, energy-induced tissue damage was not statistically different for the two ultrasonic power settings. Max-Setting 5 was faster and trended toward a higher rate of damage; this was balanced by equivalent distance of tissue injury compared with Min-Setting 3. In larger human specimens, the use of Max-Setting 5 may be recommended to decrease surgical time as it is faster and causes an equivalent amount of injury to Min-Setting 3