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PubMedDate not supplied

Morphometry of the larynx in horizontal sections.

PURPOSE: Until recently, only few studies on laryngeal morphometry in the horizontal plane, which used unreliable techniques, have been reported. The established methods of whole-organ serial sectioning of the larynx serve the purpose of histological investigation very well. Because they cause major tissue shrinkage, these techniques are not useful for morphometry. Nevertheless, normal data of laryngeal horizontal anatomy are of great surgical and diagnostic interest. Data on endolaryngeal angles, airway lumina, and the thickness of parts of the laryngeal skeleton can be helpful in the planning of endolaryngeal surgical intervention or the transcutaneous placement of electrodes for laryngeal electromyography. The aim of this study was to establish a method for the production of whole-organ serial sections that allows for the collection of exact and reliable morphometrical data. MATERIALS AND METHODS: A total of 20 fresh human cadaver larynges were investigated in this study. Nineteen measurements on three different planes were obtained in each larynx. The larynges were shock-frosted using liquid propane and nitrogen and then cut with a slicing machine. Measurements were obtained using a computer-aided analyzing system. RESULTS: The collected data give an exact and extensive description of the morphometrics of laryngeal structures such as thyroid and cricoid cartilage, arytenoid cartilages, vocal cords, and endolaryngeal airways at different section levels. CONCLUSION: This study is the first to provide detailed anthropometric data on whole-organ sections of the larynx following a new method. This technique of using serial sections of the investigated specimen avoids artifacts caused by tissue fixation. Thus, it may be considered being particularly suited to the conduction of anthropometric studies on human larynges.

Aged↗
PubMed1995

Immunohistochemical detection of the effects of toxic injury on the central nervous system.

Immunohistochemistry currently is the most powerful tool to identify specific molecules in situ. Moreover, antibodies can detect modifications of cellular polypeptides that occur naturally or as a result of toxic or other injuries. Here we report on a variety of parameters (fixation, tissue pretreatments, chromagen intensification, etc.) that we found to enhance immunohistochemical staining. Further, the use of well characterized antibodies and concomitant immunoblotting help avoid false positive results in immunohistochemistry. Finally, the sensitivity of the immunohistochemical procedure, regional differences in immunostaining within the central nervous system, as well as the recognition of equivalent molecules across different animal species are discussed.

Animals↗
PubMed1996

The ultrastructure of bradyzoites and tissue cysts of Neospora caninum in dogs: absence of distinguishing morphological features between parasites of canine and bovine origin.

The fine structure of bradyzoites and tissue cysts of Neospora caninum in dogs is described. Original findings consisting of branching, septa-like structures of the cyst wall and peculiar, lipid-like inclusions in the cyst ground substance were described. Tubulo-vesicular structures in the cyst ground substance and distinctive, vesicular organelles containing short, membranous segments and smaller vesicles, described in Neospora parasites of bovine origin and previously undescribed in parasites of canine origin, were also observed. The findings in this study indicate that there are no distinct ultrastructural morphological criteria differentiating N. caninum in dogs and the Neospora-like protozoan of cattle. The previously reported morphological distinction between parasites of canine and bovine origin may be attributed to the relatively small numbers of tissue cysts examined, differences in tissue fixation and processing, and variation in developmental stage of the parasites examined.

Animals↗
PubMed1989

Histamine-immunoreactive nerve fibers in the rat brain.

A new immunohistochemical method that utilizes carbodiimide as a tissue fixative was applied to study the distribution of histamine-immunoreactive neuronal fibers and terminals in the rat brain. Immunoreactive fibers were observed in almost all major regions of the brain. They were most numerous in the different hypothalamic nuclei. Dense networks of immunoreactive fibers were also seen in the medial septum, nucleus of the diagonal band and ventral tegmental area. A moderate density of fibers was seen throughout the cerebral cortex, in some parts of the olfactory bulb and tubercle, bed nucleus of the stria terminalis, amygdala, basal parts of the hippocampus, inferior and superior colliculi, substantia nigra, lateral and medial parabrachial nucleus, and the nucleus of the solitary tract. Few histamine-immunoreactive fibers were seen in most parts of the caudate putamen, most thalamic nuclei, most pontine and ventral medullary nuclei. Histamine-immunoreactive neuronal cell bodies were found exclusively in the tuberomammillary nucleus, in agreement with previous reports. The results provide evidence for a widespread distribution of histamine-containing nerve fibers and terminals in the rat brain. Although immunohistochemical localization of histamine does not give direct evidence of a functional role of histamine in any brain area, this distribution suggests involvement in functions of the limbic system including the septal nuclei, hypothalamus and amygdala. The relatively dense histamine-immunoreactive fiber networks in the colliculi and dorsal cochlear nucleus indicate that this amine may play a role in visual functions and hearing. The paucity of immunoreactive fibers in the pontine and medullary areas suggests that the caudal projections originating from the tuberomammillary complex are minor ones compared to the major rostral projections. Several fiber projections originating from the tuberomammillary complex could be deduced from serial frontal, sagittal and horizontal sections. They contained fibers that crossed the midline at several levels of the brain. The results provide information on the target areas of the histaminergic neurons and form a basis for the examination of cellular contracts between the histaminergic neurons and other cells.

Animals↗
PubMed2006

Immunohistochemical distribution of cAMP- and cGMP-phosphodiesterase (PDE) isoenzymes in the human prostate.

OBJECTIVES: With the introduction of sildenafil citrate (Viagra), the concept of phosphodiesterase (PDE) inhibition has gained tremendous interest in the field of urology. Cyclic nucleotide second messengers cGMP and cAMP have been assumed to be involved in the control of the normal function of the prostate. The aim of the present study was to evaluate by means of immunohistochemistry the expression and distribution of some cAMP- and cGMP-PDE isoenzymes in the prostate. MATERIAL & METHODS: Cryostat sections (10 microM) of formaldehyde-fixated tissue segments excised from the transition zone of human prostates were incubated with primary antibodies directed against the PDE isoenzymes 3, 4, 5, and 11. Then, sections were exposed to either fluorescein isothiocyanate- (FITC) or Texas Red- (TR) labeled secondary antibodies and visualization was commenced by means of laser fluorescence microscopy. RESULTS: TR-immunofluorescence indicating the presence of PDE4 (cAMP-PDE) was abundantly observed in the fibromuscular stroma as well as in glandular structures of the transition zone. In contrast to the distribution of PDE4, immunoactivity indicating PDE5 (cGMP-PDE) and 11 (dual substrate PDE) was mainly observed in glandular and subglandular areas. No immunostaining for PDE3 (cGMP-inhibited PDE) was detected. CONCLUSION: Our results confirm the presence of PDE isoenzymes 4, 5 and 11 in the transition zone of the human prostate and present evidence that these isoenzymes are not evenly distributed. These findings are in support of the hypothesis that there might be a rationale for the use of PDE inhibitors in the pharmacotherapy of BPH and LUTS.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1996

Computerized assessment of coronary lumen and atherosclerotic plaque dimensions in three-dimensional intravascular ultrasound correlated with histomorphometry.

Intravascular ultrasound (IVUS), which depicts both lumen and plaque, offers the potential to improve on the limitations of angiography for the assessment of the natural history of atherosclerosis and progression or regression of the disease. To facilitate measurements and increase the reproducibility of quantitative IVUS analyses, a computerized contour detection system was developed that detects both the luminal and external vessel boundaries in 3-dimensional sets of IVUS images. To validate this system, atherosclerotic human coronary segments (n = 13) with an area obstruction > or = 40% (40% to 61%) were studied in vitro by IVUS. The computerized IVUS measurements (areas and volumes) of the lumen, total vessel, plaque-media complex, and percent obstruction were compared with findings by manual tracing of the IVUS images and of the corresponding histologic cross sections obtained at 2-mm increments (n = 100). Both area and volume measurements by the contour detection system agreed well with the results obtained by manual tracing, showing low mean between-method differences (-3.7% to 0.3%) with SDs not exceeding 6% and high correlation coefficients (r = 0.97 to 0.99). Measurements of the lumen, total vessel, plaque-media complex, and percent obstruction by the contour detection system correlated well with histomorphometry of areas (r = 0.94, 0.88, 0.80, and 0.88) and volumes (r = 0.98, 0.91, 0.83, and 0.91). Systematic differences between the results by the contour detection system and histomorphometry (29%, 13%, -9%, and -22%, respectively) were found, most likely resulting from shrinkage during tissue fixation. The results of this study indicate that this computerized IVUS analysis system is reliable for the assessment of coronary atherosclerosis in vivo.

Adult↗
PubMed1986

The protective effect of profound hypothermia on the canine central nervous system during one hour of circulatory arrest.

Circulatory arrest during profound hypothermia is a safe technique of cardiac surgery when used in selected instances. Despite its proven safety, the degree of cerebral protection offered by this technique is still poorly defined. Ten dogs anesthetized with Pentothal (thiopental sodium) were surface cooled to 32 degrees C. They were placed on cardiopulmonary bypass, cooled to 13 degrees C (cerebral temperature), and then underwent one hour of circulatory arrest. At the end of the arrest period, the dogs were rewarmed, resuscitated, and successfully weaned from bypass. A control group of 6 dogs were subjected to the same protocol but without the one-hour period of circulatory arrest. There were no group differences in animal weight, duration of surface cooling, cardiopulmonary bypass, or rewarming, mean flow, or mean arterial pressure. After a 7-day observation period, the dogs were killed with rapid tissue fixation using formalin. No neurological deficits were noted in any of the dogs during the observation period. The fixed brains were examined by a neuropathologist. No gross or microscopic evidence of cerebral hypoxia was seen in any of the animals. We conclude that one hour of circulatory arrest under profoundly hypothermic temperatures produces no detectable neurological changes or histological evidence of cerebral hypoxia.

Animals↗
PubMed2003

A novel endoscopic full-thickness plicator for the treatment of GERD: A pilot study.

BACKGROUND: The novel full-thickness plication described in this study was designed to inhibit gastroesophageal reflux by placement of a transmural plication near the gastroesophageal junction under direct endoscopic visualization. The resulting serosa-to-serosa tissue union is thought to accentuate and restore the valvular mechanism of the gastroesophageal junction. The aim of this study was to assess the safety and feasibility of endoscopic full-thickness plication for the treatment of patients with GERD symptoms. METHODS: A pilot study was performed in patients with chronic heartburn and pathologic reflux requiring maintenance antisecretory therapy. A single full-thickness plication was placed in the gastric cardia within 1 to 2 cm of the gastroesophageal junction. The primary end points of the study were procedure safety and feasibility, as well as long-term durability of the full-thickness tissue fixation. Secondary end points included medication use and the GERD-Health Related Quality of Life questionnaire and Gastrointestinal Symptom Rating Scale. RESULTS: Full-thickness plication was performed successfully in 6 of 7 patients, with one procedure aborted because of difficulty in sedating the patient. Mean procedure time was 21 minutes. Mild epigastric pain was reported by two patients and difficulty with eructation by one patient; all symptoms resolved spontaneously within 7 days of the procedure. Endoscopy at 6 months revealed an intact plication in all patients. At 1 year after the procedure, patients reported sustained reduction in heartburn scores. One patient, who did not experience significant relief of symptoms, ultimately underwent successful laparoscopic Nissen fundoplication at 6 months after the procedure. At 1 year after the procedure, 3 of 5 patients were not taking anti-GERD medications. CONCLUSIONS: Endoscopic full-thickness plication is feasible, safe and, in this pilot study, appeared to reduce symptoms and medication use associated with GERD.

Adult↗
PubMedDate not supplied

Dynamic changes in NADPH-diaphorase staining reflect activity of nitric oxide synthase: evidence for a dopaminergic regulation of striatal nitric oxide release.

In fixed tissue, neuronal NADPH-diaphorase staining results from nitric oxide synthase (NOS) activity. Neuronal NOS only synthesizes nitric oxide once activated by the binding of Ca2+/calmodulin. We show here that neuronal NADPH-diaphorase staining is also dependent on Ca2+/calmodulin, implying that only activated NOS is detected. In addition, in bovine pulmonary endothelial cells, carbachol and bradykinin dramatically and rapidly increase the intensity of NADPH-diaphorase staining. Furthermore, administration of MK801, an NMDA antagonist, decreases neuronal NADPH-diaphorase staining. This suggests that the intensity of the NADPH-diaphorase staining is related to the level of enzyme activation at the moment of tissue fixation. The potential of exploiting this observation to detect cellular activation of NOS is illustrated by the observations that the intensity of NADPH-diaphorase staining in rat striatal neurones is decreased following systemic treatment with the D1-like dopamine receptor antagonist SCH23390, and increased by the D2-like antagonist eticlopride. These results therefore provide strong evidence that the NADPH-diaphorase reaction can be used to monitor NOS activity at a cellular level of resolution, and reveal a dopaminergic regulation of NOS activity in the striatum mediated by D1-like and D2-like dopamine receptors.

Animals↗
PubMed1998

Intraurethral ultrasound correlated with urethral histology.

OBJECTIVE: To examine the anatomic identity of sonographically visible sphincteric structures of the female urethra. METHODS: The urethra, urinary bladder, and vagina were removed from 11 fresh female cadavers and placed in a water bath. Intraurethral ultrasound was performed with a 360 degrees-rotating 7.5-MHz ultrasound probe. Afterward, the specimens were fixed and cross sections were made transverse to the urethral axis at 5-mm intervals. Corresponding ultrasonograms and histologic images were matched and depicted simultaneously side by side. The anatomic identity of sonographically visible structures was determined by histologic examination and thickness of the longitudinal smooth urethral sphincter measured. RESULTS: Structures visible sonographically were the striated and smooth urethral sphincter muscle layers, vagina, and blood vessels with diameters exceeding 0.2 mm. The longitudinal smooth muscle layer appeared as a well-defined internal hypoechoic ring. The outer circular smooth muscle layers and the striated muscle layers were a more irregular and hyperechoic zone. The circular smooth muscle layers and the striated sphincter muscle layers could not always be differentiated easily. With formalin fixation, tissue shrinkage resulted in a smaller thickness of the longitudinal smooth muscle measured on the histologic specimen. CONCLUSION: With intraurethral ultrasound, the longitudinal smooth muscle layer appears as a well-defined and measurable hypoechoic ring. The region of the circular smooth muscle and the striated muscle emerges as a hyperechoic and less definable outer zone.

Adult↗
PubMed2000

Luminal contents of benign and malignant prostatic glands: correspondence to altered secretory mechanisms.

Recent changes in tissue fixation strategy, using glutaraldehyde, have clarified the secretory mechanisms of the normal prostate identifying cytoplasmic prostatic secretory granules, structures not preserved by formalin fixation. This normal secretory mechanism was absent in most adenocarcinomas, depicting an important metabolic change in transformed prostate cells. The current study further investigates differences between benign and malignant prostate secretion and relates them to the production of corpora amylacea by benign glands and crystalloids or mucin by cancer. In all normal prostate cells examined (6 cases), prostate secretory granules (PSG) were approximately 1-microm, brightly eosinophilic granules filling the cytoplasm of secretory cells and released in packets by a specialized apocrine cell structure. After apocrine decapitation and luminal dispersal, some of the cytoplasmic and PSG remnants condensed to form eosinophilic bodies (EB) with a glycoprotein rim and central protein core. EB were observed adsorbing and layering onto the surface of prostatic corpora amylacea representing their chief mode of enlargement. Biochemical analysis and x-ray diffraction studies confirmed sulfated glycosaminoglycans of similar structure as the main constituent of both PSG and corpora amylacea. Peripheral zone amphiphilic "dark cell" carcinoma (9 cases) contained almost no PSG, and showed neither apical decapitation nor EB formation, but mucin secretion was frequently detected. Crystalloids that share the same staining characteristics and sulfur content as PSG and corpora amylacea were identified in 3 selected "clear cell" carcinomas, all of which showed at least focal PSG secretion. The recognition of these differing secretory mechanisms and their deviation from normal further defines the histological criteria and spectrum of prostate malignancy.

Acid Phosphatase↗
PubMed1984

Enucleation with implantation of a proplast sphere.

Proplast, an inert carbon-Teflon alloplastic material, was tested as a primary spherical implant after unilateral enucleation in albino rabbits. The implants were removed at 3 months in three rabbits and at 6 months in the remaining three rabbits. Clinical observation confirmed a high degree of soft tissue fixation and no implant migration. The implant material submitted for light and electronmicroscopy showed extensive fibrovascular ingrowth throughout its matrix without encapsulation of the implant. Subsequent human use has shown good results in four patients followed for 2 years and an additional six patients followed for 1 year.

Animals↗
PubMed1990

A user's guide to veterinary surgical pathology laboratories. Or, why do I still get a diagnosis of chronic dermatitis even when I take a perfect biopsy?

During the past decade, clinicians have come to rely more heavily on veterinary surgical pathology services to provide assistance in the diagnosis of inflammatory and neoplastic skin disease. To obtain maximum results from each skin biopsy, it is important that clinicians have a good understanding of the factors that can affect histologic evaluation after the biopsy specimen has been removed from the patient. This article discusses the role proper tissue fixation, trimming, and grooming can play in obtaining an accurate histologic evaluation. The importance of understanding the limits of dermatopathology in establishing a definitive diagnosis of many inflammatory and neoplastic skin diseases is emphasized.

Animals↗
PubMed2001

Mast cell distribution and density in the normal uterus--metachromatic staining using lectins.

This study investigates the number and the distribution of mast cells in the normal human uterus. Reliability of results was ensured by prompt tissue fixation and the use of biotin-labelled lectins in conjunction with the avidin-biotin peroxidase complex (ABC) method. This design revealed that mast cells are, indeed, normal constituents of the human uterus. They occur in large numbers in the myometrium, but are only scanty in the endometrium where they tend to be confined to the stratum basalis. The mean mast cell counts per high power field (MC/HPF), after staining with Canavalia ensiformis agglutinin (Con A), were 17.9MC/HPF in the inner half of the myometrium, and 8.3MC/HPF in the outer half of the myometrium; 2.7MC/HPF in the basalis, and 0.3MC/HPF in the functionalis (P<0.05). There are no apparent differences in the number of mast cells between the normal proliferative and secretory phase endometrium, however, endometrial mast cells are considerably reduced and, apparently, depleted of metachromatic granules during the immediate pre-menstrual phase of the menstrual cycle. It is presumed that this, almost exclusive, presence of mast cells in the basal layer of the endometrial matrix, combined with the discharge of their cytoplasmic granules towards the end of the cycle, may be related with the contracting process preceding menstruation. On the other hand, the relative paucity of mast cells in the functional layer may contribute to the immune tolerance of the gestational endometrium to the implantation of the blastocyst.

Adult↗
PubMed1989

The use of lectins in histopathology.

Lectins are proteins and glycoproteins extracted predominantly from plants which have the capacity to bind sugars specifically. This property makes them of interest for histopathology since they will bind to saccharides forming parts of glycoproteins and glycolipids of tissue constituents. Lectins have and can be used as reagents for mucin histochemistry, to identify specific cells, in the recognition of glycoprotein alterations in disease states, in studies of infectious diseases, and in the assessment of glycoconjugate alterations occurring with malignancy. They can be used for both light microscopic and ultrastructural localisation and various methods are available. It is important though, to consider the nature of the glycoconjugates under study and select lectins appropriately because of their varying specificities and binding characteristics. A panel of lectins should be used to study a particular configuration. Care should be taken with tissue fixation and processing. It must be remembered that an open and critical mind should be kept concerning interpretation of results. At the present time lectins have a limited value diagnostically, but the binding of Ulex europeus agglutinin to endothelium is certainly of value.

Animals↗
PubMed1996

Glutamine synthetase and glutamate metabolism in the guinea pig cochlea.

Glutamate is thought to act as a neurotransmitter of the sensory hair cells of the organ of Corti. Glutamine synthetase could be involved in a type of glutamate-glutamine cycle in the cochlea which could clear glutamate off the synaptic cleft and replenish the hair cell glutamate neurotransmitter store. Using both light and electron microscopic immunocytochemistry to localize this enzyme in the guinea pig cochlea, we have observed immunoreactive satellite glial cells surrounding parvalbumin-immunoreactive primary auditory neurons in the spiral ganglion. Glutamine synthetase was also detected in Schwann cells of the osseous spiral lamina which form the myelin sheath of nerve fibers. On the contrary, no immunoreactivity could be observed in the cochlear nerve and in the organ of Corti, although this organ contains structures able to take up glutamate. Although they confirm earlier works involving glutamine synthetase in the conversion of L-[3H]glutamate taken up by glial cells, our results suggest that the cochlear glutamate-glutamine cycle is not primarily involved in the recycling and replenishment of hair cell neurotransmitter glutamate. Alternatively, it is proposed that glutamine synthetase functions to limit the perilymphatic glutamate concentrations.

Animals↗
PubMed2001

Significance of the internal locking mechanism for loop security enhancement in the arthroscopic knot.

PURPOSE: Secure tissue fixation of an arthroscopic knot depends on the security of the initial loop and additional locking half-hitches. The purpose of this report is to evaluate the loop and knot security relative to the internal locking mechanism of arthroscopic slip knot. TYPE OF STUDY: This is an experimental study designed for knot and loop security on a material testing system. The measurements were carried out in a blinded fashion in which the tester was not aware of the type of knot being tested. METHODS: Five configurations of arthroscopic knots (overhand throw, Duncan loop, Revo knot, Tennessee slider, and SMC knot) were created around a 5-mm diameter metal bar using a No. 2 braided suture. For each knot configuration, 10 knots were tested for displacement at cyclic loading, load to clinical failure (3-mm displacement), ultimate failure load, and mode of failure on the servo-hydraulic material testing system (MTS 858 MiniBionix test system; MTS, Minneapolis, MN). A 1-way analysis of variance was used to determine the statistical difference in displacement at cyclic loading, load to clinical failure, and ultimate failure load between each knot configuration. RESULTS: In the cyclic loading test, the average displacement of all knots was clinically insignificant, with the average being less than 0.24 mm. The overhand throw had the worst characteristic in the load to failure test. The other 4 knots had an optimal load to failure. The SMC knot, which has an internal locking mechanism, had good loop and knot security in the load to clinical failure and ultimate failure load (P <.05). The SMC and the Revo knots failed by knot breakage (material failure) whereas the other knots failed by knot slippage (loop failure). CONCLUSIONS: The internal locking mechanism flips the post strand to convert the loop strand into a new post strand while rerouting the original post strand around a new post. An arthroscopic knot with an internal locking mechanism can enhance loop security.

Analysis of Variance↗
PubMedDate not supplied

A comparison of soft-tissue anchors in tendo achilles reattachment.

This prospective study evaluated four soft-tissue fixation modalities, used in seven different combinations, to reattach the tendo Achilles in 34 cadaveric specimens. Ultimate loads, elastic moduli, and modes of failure were evaluated by loading the specimen in a cantilevered fashion on an Instron. Mann-Whitney U tests were performed to compare the failure load data for statistical significance. Although the use of two Mitek SuperAnchors showed better load resistance than one anchor (p < .01), there was no significant improvement between using two or three anchors (one anchor 116 +/- 24 N, two anchors 234 +/- 21 N, three anchors 277 +/- 80 N). Two Bionx Bankart Tacks demonstrated no significant difference over using a single tack (one tack 178 +/- 57 N, two tacks 214 +/- 86 N). No statistical difference was observed between the screw and washer systems (screw with polyacetal resin washer 307 +/- 80 N, screw with metal washer 290 +/- 81 N). Both screw and washer systems did show greater stability when compared with a single Mitek SuperAnchor (p < .01) or a single Bionx Bankart Tack (p < .05). Similar analyses using the Mann-Whitney U tests were performed on the elastic modulus data. Analysis of the displacement data among all groups showed no statistical difference. Observations of the mode of failure exhibited 86% of Mitek SuperAnchor failed secondary to suture, and 70% of the Bionx Bankart Tack and 90% of the screw and washer systems failed because of the tendon shearing around the fixation. The comparisons of cost-effectiveness among the fixations showed the Synthes screw and polyacetal resin spiked washer to have the lowest cost to load ratio ($0.15/N).

Achilles Tendon↗