Disseminated toxoplasmosis in a captive ring-tailed lemur (Lemur catta)

A 3-yr-old secundiparous female ring-tailed lemur presented to the Auburn University Small Animal Clinic with signs of dyspnea, lethargy, and anorexia. The animal died before she could be examined, and a full necropsy was immediately performed. Provisional necropsy findings included moderate pneumonia and hepatopathy. Acute interstitial pneumonia and focal hepatocellular necrosis were confirmed histologically. Lung impression smears, histopathology, electron microscopy, immunohistochemistry, and tissue culture isolation resulted in a diagnosis of acute disseminated Toxoplasma gondii infection, which was confirmed by polymerase chain reaction. The isolate of T. gondii was avirulent for mice and was named AU Tgl and genetically is type II. The source of the infection remains unclear, but speculation suggests contaminated fruit or blackbirds (Passeriformes: Icteridae) acting as transport hosts for oocysts from nondomestic felids and feral cats on the property.     

Relapses and Remissions in Brain Stem Tumours

Three cases of brain stem astrocytoma and one of a para-stem vascular tumour are described, each showing a history of relapses and remissions. The diagnoses were confirmed by necropsy, and it is suggested that the relapsing course may have been due to oedema and necrosis in both the tumour and the surrounding brain tissue. Features indicating repeated recurrence of a lesion at the same site in the brain stem justify full neuroradiological investigation before a diagnosis such as multiple sclerosis can be accepted.     

A new method to gently place biopsy needles or treatment electrodes into tissues with high target precision

We present a new core needle biopsy and treatment electrode precision placement technique which, regardless of needle size, target lesion hardness and elasticity, makes it possible to precisely place an image guided device inside the abnormal tissue. Once inside the abnormal lesion, multiple tissue samples can be collected using a dedicated trocar and collecting system. Our unique “Fourier” driver substitutes the commonly used spring-loaded device or complements the jerky insertion technique used by experienced interventional physicians. It enables the physician to precisely and with extreme tactility maneuver even large diameter core needles or treatment-electrodes into the lesion using only a diminutive external force. This is achieved by applying supporting servo-controlled mechanical high-acceleration micro-pulses, proportional to the average vector directed by the physician. The Fourier-needle or Fourier-electrode stands completely non-moving when the system automatically goes into full idling. This means that the angle of attack successively and arbitrary can be aligned to hit the target, becoming successively symmetrically inserted into even small tumors to be treated as well as exactly hit any point outlined by real time ultrasound guiding. This kind of biopsy needle or treatment electrode placement results in a uniquely accurate and less traumatic procedure. Due to the risk of disseminating viable tumor cells the precision placement device can be combined with a computer controlled anti-seeding system, denaturizing tumor cells detached during penetration of the biopsy needle or treatment electrode.     

Comparative validation of c-kit exon 11 mutation analysis on cytology samples and corresponding surgical resections of gastrointestinal stromal tumours

Objective:  Studies have shown that c-kit mutation analysis of gastrointestinal stromal tumours (GISTs) obtained by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) can be routinely performed. We validated c-kit exon 11 mutational analysis on cell block material obtained from fine needle aspiration cytology (FNAC) for diagnostic purposes and compared it with the same analysis in formalin-fixed paraffin-embedded full sections of the corresponding resection specimens.
Methods:  c-kit mutation analysis was done on cell block material obtained from ten cases encountered in our department from 1999 to 2008 on which FNAC was attempted pre-operatively. The findings were compared with analysis on full paraffin section of the corresponding resected tumours in seven cases where patients opted for resection. c-kit exon 11 was examined via bidirectional nucleic acid sequencing.
Results:  Our results showed 100% concordance for the presence and type of exon 11 mutation in the resected and aspirated tumours in all seven cases. These mutations had diagnostic value when compared with other neoplasms that are part of the cytomorphological differential diagnosis, such as leiomyosarcoma or gastric adenocarcinomas.
Conclusion:  Molecular cytopathology is a powerful tool that can complement morphology and immunohistochemical assessment of cytological material in routine practice for the diagnosis and prognostication of GISTs. We briefly discuss the advantages and limitations of the fine needle method of obtaining tissue for the diagnosis and prognostication of GISTs, and its current therapeutic strategies.     

Standardized method for the harvest of nonhuman primate tissue optimized for multiple modes of analyses

Appropriate animal models are critical to conduct translational studies of human disorders without variables that can confound clinical studies. Such analytic methods as patch-clamp electrophysiological and voltammetric recordings of neurons in brain slices require living brain tissue. In order to obtain viable tissue from nonhuman primate brains, tissue collection methods must be designed to preserve cardiovascular and respiratory functions for as long as possible. This paper describes a method of necropsy that has been used in three species of monkeys that satisfies this requirement. At necropsy, animals were maintained under a deep surgical plane of anesthesia while a craniotomy was conducted to expose the brain. Following the craniotomy, animals were perfused with ice-cold, oxygenated artificial cerebrospinal fluid to displace blood and to reduce the temperature of the entire brain. The brain was removed within minutes of death and specific brain regions were immediately dissected for subsequent in vitro electrophysiology or voltammetry experiments. This necropsy method also provided for the collection of tissue blocks containing all brain regions that were immediately frozen and stored for subsequent genomic, proteomic, autoradiographic and histological studies. An added benefit from the design of this necropsy method is that all major peripheral tissues were also collected and are now being utilized in a wide range of genomic, biochemical and histological assays. This necropsy method has resulted in the establishment and growth of a nonhuman primate alcohol tissue bank designed to distribute central nervous system and peripheral tissues to the larger scientific community.     

A microassay for the measurement of androgen receptors in human prostatic tissue.

A microassay utilizing R 1881 (methyltrienolone) has been developed for the measurement of androgen receptor sites in the cytosol and nuclear extract of human prostatic tissue. Binding of R 1881 to the progesterone binding molecule in cytosol was eliminated by the addition of triamcinolone acetonide. Utilizing a six tube, single point assay, the number of binding sites estimated in nuclear extract averaged 95% of the number measured by a full 7 point Scatchard analysis; the number estimated by the microassay in cytosol averaged 91%. When the single point assay was applied to needle biopsy specimens (200 mg of tissue), the estimated number of binding sites in nuclei averageed 83% of the number measured in bulk tissue (2 grams) utilizing a 7 point Scatchard analysis; the number in cytosol estimated by the microassay on needle biopsy specimens averaged 73%. It is hoped that this technique may be useful in correlating receptor content with hormonal responsiveness in men with metastatic carcinoma of the prostate.     

Detailed finite element modelling of deep needle insertions into a soft tissue phantom using a cohesive approach

Detailed finite element modelling of needle insertions into soft tissue phantoms encounters difficulties of large deformations, high friction, contact loading and material failure. This paper demonstrates the use of cohesive elements in high-resolution finite element models to overcome some of the issues associated with these factors. Experiments are presented enabling extraction of the strain energy release rate during crack formation. Using data from these experiments, cohesive elements are calibrated and then implemented in models for validation of the needle insertion process. Successful modelling enables direct comparison of finite element and experimental force–displacement plots and energy distributions. Regions of crack creation, relaxation, cutting and full penetration are identified. By closing the loop between experiments and detailed finite element modelling, a methodology is established which will enable design modifications of a soft tissue probe that steers through complex mechanical interactions with the surrounding material.     

Resistance forces acting on suture needles

Understanding the resistance forces encountered by a suture needle during tissue penetration is important for the development of robotic surgical devices and virtual reality surgical simulators. Tensile forces applied to skin and tendon during suturing were measured. Fresh sheep achilles tendons were tensioned with a static load 4.9 N, 9.8 N or 19.6 N and sheepskin with 0.98 N, 2.9 N or 4.9 N static load. A straight 2/0 cutting suture needle in series with a load cell on a materials testing machine penetrated the tissue at 90 degrees with a velocity of 1, 5 or 10mm/s for each tissue tension (n=5). Continuous load versus displacement data was obtained and penetration load and stiffness were noted. The load versus displacement curve for skin during needle penetration demonstrated two characteristic peaks, corresponding to initial penetration and emergence of needle from the undersurface of the tissue. Increasing the tension within the tissue (skin and tendon) increased the amount of force required to penetrate the tissue with a suture needle (p<0.05). Needle displacement rate did not affect the resistance to needle penetration (p<0.05). This study provides a simple model for measuring force-feedback during needle penetration of soft tissues and is a good starting point for future studies of the penetration resistance properties of human tissues.     

Value and quality of perinatal and infant postmortem examinations: cohort analysis of 400 consecutive deaths.

OBJECTIVES--To evaluate the contribution that perinatal and infant necropsy makes to clinical practice and to see how this might be influenced by the quality of the investigation. DESIGN--Cohort analysis, with data from the all Wales perinatal survey, of perinatal and infant deaths during 1993 of babies born to mothers usually resident in Wales. The clinicopathological classification of death based on clinical details was compared with the classification after necropsy. Similarly, cases in which necropsy yielded new information were identified. The quality of the necropsy was assessed by scoring six aspects of the examination. SUBJECTS--400 consecutive deaths at 20 weeks of gestation to 1 year of age. MAIN OUTCOME MEASURES--Necropsy rate, effect of necropsy on clinicopathological classification, new information disclosed by necropsy, quality of necropsies, and the link between new information and quality of the necropsy. RESULTS--Necropsy was performed in 232 cases (58%). The clinicopathological classification was altered by necropsy in 29 cases (13%). New information was obtained in 60 cases (26%), and in 42 (18%) it disclosed the cause of death. The quality of necropsy was substantially higher when the main cause of death was detected than when nothing new was found. CONCLUSION--Necropsy is underused. Clinicians should be more positive about necropsies and realise how much clinically relevant information can be obtained from a good quality examination.     

Bone-marrow biopsy needle incorporating a snare-coil specimen-capturing device: description and preclinical studies

A tissue biopsy needle maximizes adequate specimen retrieval and minimizes patient pain and tissue disruption. The proposed biopsy needle incorporates an internal snare-coil for capturing specimens. The snare-coil device is described along with needle durability and performance testing. Sharply cut, nonfragmented, cored specimens were retrieved from a resin-based foam. In clinical practice, the snare-coil technology may minimize post-insertion needle manipulations and patient pain. Further studies are required to determine the impact of snare-coil needles on the retrieval of adequate specimens from patients.     

Improved method for bile collection in unrestrained conscious rats.

We describe an improved method for continuous collection of bile from unrestrained rats. Use of an externally accessible, continuous-loop cannula when cannulating the common bile duct allows for full recovery from anesthetic effects and maintenance of a normal bile salt pool until the cannula loop is cut. Bile resulting from the cut cannula is diverted into a surgically implanted glass collection vessel and removed periodically via an externalized sampling port. Bile flow over a 24-hour collection period averaged 0.98 +/- 0.04 ml/hr (Mean +/- SEM, n = 9) with no gross pathological changes noted upon necropsy. This technique offers the capability of reestablishing conditions as close to physiologic as possible postsurgery to minimize potential artifacts during bile collection.     

Canine mastocytoma: report of 8 cases diagnosed by fine needle cytology and clinicopathologic correlations

BACKGROUND: Mast cell proliferations are commoner in dogs than in humans; mass forming lesions in the former are apt to fine needle sampling and the obtained cytopathological picture might be informing to enhance recognition of similar proliferations in humans. CASE: Clinical and cytopathologic data were collected from 8 cases of canine mastocytomas diagnosed by fine needle cytology. The cytopathologic presentation was correlated with the individual therapy performed and with the clinical stage. In all cases the cytopathological diagnosis was confirmed by histopathologic examination of the excised mass, by necropsy or by response to therapy. CONCLUSION: There are marked similarities between canine and human mastocytomas, despite possible differences in the clinical course of the disease in both species. Canine mastocytomas may hence be used as an animal model of a human disease and, as such, familiarity with their cytologic presentation may be useful for recognizing mast cell proliferations in humans.     

A computational approach to investigate optimal cutting speed configurations in rotational needle biopsy cutting soft tissue

The rotational cutting method has been used in needle biopsy technologies to sample tough tissues, such as calcifications in the breast. The rotational motion of the needle introduces shear forces to the cutting surface such that the cutting force in the axial direction is reduced. As a result, tissue samples with large volume and better quality can be obtained. In order to comprehensively understand the effect of the needle rotation to the axial cutting force under a wide range of the needle insertion speed, this paper demonstrates a computational approach that incorporates the surface-based cohesive behavior to simulate a rotating needle cutting soft tissue. The computational model is validated by comparing with a cutting test dataset reported in the literature. The validated model is then used to generate response surfaces of the axial cutting force and torque in a large parameter space of needle rotation and insertion speeds. The results provide guidelines for selecting optimal speed configurations under different design situations.     

不同杉木无性系叶片解剖结构对大气增温的响应

以10个不同杉木无性系幼林叶片为研究对象,在对研究地气候因子进行分析基础上,采用微波石蜡快速切片法制作叶片解剖结构,通过观测比较叶片8项解剖结构指标的差异规律,研究不同杉木无性系叶片解剖结构在大气增温背景下的响应特征。结果表明：（1）研究地2020年度夏季气温呈先上升后下降的趋势,降水量变化与之相反,呈现出明显的高温干旱现象。（2）不同杉木无性系叶片解剖结构相似,叶肉组织分化为栅栏组织和海绵组织,为典型异面叶;解剖结构指标除下表皮厚度外,其余指标在无性系间呈现出不同程度的改变,表现出对大气增温响应的形态可塑性差异。（3）相关性分析结果表明,叶片解剖结构指标之间存在一定自相关关系;气候因子中,月平均气温与栅栏组织呈极显著正相关关系（P<0.01）,月均降水量与栅栏组织、海绵组织、栅海比均呈极显著正相关关系（P<0.01）。（4）根据主成分分析结果,筛选出海绵组织、栅栏组织、叶片厚度、表皮组织和角质层为表征杉木叶片解剖结构的典型指标,反映出在大气增温背景下杉木叶片解剖结构变化特征以抵抗强烈光照和减少水分散发的特性。（5）不同杉木无性系叶片可塑性指数均值排序结果为W2 > P11 > S4 > P32 > P41 > P17 > P18 > S22 > S23 > 洋061,表明不同杉木无性系对大气增温的生态适应性与之相对应。综上可见,不同杉木无性系对环境的适应能力存在差异,叶片具有较强的形态可塑性变化,当气温改变时,杉木可通过叶片解剖结构调整以应对不断增加的大气温度带来的高温干旱复合逆境胁迫,未来应充分重视气候变化对杉木人工林生长发育的影响。     

Technique of percutaneous anchoring suture placement

We describe a technique to assist in the placement of percutaneous anchoring sutures when used in poorly accessible tunnels such as in rhinoplasty by using a sucker tube to guide retrieval and placement of the suture needle. This technique avoids unintended catching of the needle on soft tissue within the tunnel, which could prevent the structure from becoming anchored at other than in its intended location.     

Three‐dimensional interventional photoacoustic imaging for biopsy needle guidance with a linear array transducer

Needle placement is important for many clinical interventions, such as tissue biopsy, regional anesthesia and drug delivery. It is essential to visualize the spatial position of the needle and the target tissue during the interventions using appropriate imaging techniques. Based on the contrast of optical absorption, photoacoustic imaging is well suited for the guidance of interventional procedures. However, conventional photoacoustic imaging typically provides two‐dimensional (2D) slices of the region of interest and could only visualize the needle and the target when they are within the imaging plane of the probe at the same time. This requires great alignment skill and effort. To ease this problem, we developed a 3D interventional photoacoustic imaging technique by fast scanning a linear array ultrasound probe and stitching acquired image slices. in vivo sentinel lymph node biopsy experiment shows that the technique could precisely locate a needle and a sentinel lymph node in a tissue volume while a perfusion experiment demonstrates that the technique could visualize the 3D distribution of injected methylene blue dye underneath the skin at high temporal and spatial resolution. The proposed technique provides a practical way for photoacoustic image‐guided interventions.      

Transplantation of tumour with a kidney graft.

A cerebral glioma discovered by angiography and brain biopsy in a kidney donor was subsequently suspected of being a secondary tumour. By this time a biopsy of one of the transplanted kidneys had shown a clump of malignant cells in a glomerulus. Because of the psychological state of this recipient the transplant was not removed, but the recipient of the second kidney was immediately told of the danger of tumour cell transfer, and underwent nephrectomy. The patient remained well on haemodialysis; multiple sectioning of the kidney showed no signs of tumour. The transplant in the first recipient functioned well until his death, six months after operation. At necropsy undifferentiated tumour was found in the pleura, liver, pelvic peritoneum, and transplanted kidney. All cadaver donors should undergo full laparotomy after removal of the kidneys, particularly those with a high risk of cancer, and a full necropsy should also be performed shortly afterwards to exclude tumour and other unsuspected diseases. Then it is not too late to remove a transplanted kidney should a tumour be found.     

Metastasis of cancer of the thyroid gland as a cause of goitre.

In three cases of cancer (arising in the pancreas, the breast and the lung) that had metastasized to the thyroid an unusual primary thyroid lesion was the presenting problem. While reputedly rare, metastases in the thyroid gland are not infrequently encountered at necropsy. These cases illustrate the varied causes of goitre, the value of needle aspiration and cytologic study in thyroid disease and the need for histologic vigilance. Worthwhile palliation by simple means can be obtained in such cases.     

Three-dimensional bioprinting human cardiac tissue chips of using a painting needle method

Three-dimensional (3D) printers are attracting attention as a method for arranging and building cells in three dimensions. Bioprinting technology has potential in tissue engineering for the fabrication of scaffolds, cells, and tissues. However, these various printing technologies have limitations with respect to print resolution and due to the characteristics of bioink such as viscosity. We report a method for constructing of 3D tissues with a “microscopic painting device using a painting needle method” that, when used with the layer-by-layer (LbL) cell coating technique, replaces conventional methods. This method is a technique of attaching the high viscosity bioink to the painting needle tip and arranging it on a substrate, and can construct 3D tissues without damage to cells. Cell viability is the same before and after painting. We used this biofabrication device to construct 3D cardiac tissue (LbL-3D Heart) using human-induced pluripotent stem cell–derived cardiomyocytes. The constructed LbL-3D Heart chips had multiple layers with a thickness of 60 µm, a diameter of 1.1 mm, and showed synchronous beating (50–60 beats per min). The aforementioned device and method of 3D tissue construction can be applied to various kinds of tissue models and would be a useful tool for pharmaceutical applications.     

Non-surgical cannulation of the vena cava for chronic blood collection in mature swine.

A nonsurgical cannulation technique for blood collections from mature swine was evaluated. Primiparous Yorkshire-Landrace sows (n = 6) received an indwelling jugular vein cannulae for 7 days duration. Recannulation was performed at monthly intervals for a total of 14 months. During cannulation, sows were restrained in a standing position using a rope snout snare. A 12-gauge by 10 cm needle was inserted into the jugular vein. Sterilized polyvinyl chloride tubing was advanced through the needle into the vein and a blunted 18-gauge needle and attached intermittent injection hub was inserted into the free end of the tubing. Surgical tape was used to form a butterfly on the tubing by suturing the tape to the animals' skin. Foam padding, livestock cement, and elastic tape helped to keep the tubing in position. Problems with cannulae patency and maintenance were few. No behavioral problems or systemic signs of illness were noted and necropsy examinations performed after the final cannulation revealed few abnormalities associated with chronic intermittent cannulation. This technique provides a safe, quick, effective means for multiple and repeated cannulae placement for blood collection from mature swine with minimal effects on the animal and without the risks associated with surgical techniques.