bluuebunny/crossref_metadata_2025 huggingface dataset:
Shaping ability of NT Engine and McXim rotary nickel‐titanium instruments in simulated root canals. Part 1
Authors: THOMPSON S.A. , DUMMER P.M.H.
Published: November 2003

The aim of this study was to determine the shaping ability of NT Engine and McXim nickel‐titanium rotary instruments in simulated root canals. In all, 40 canals consisting of four different shapes in terms of angle and position of curvature were prepared by a combination of NT Engine and McXim instruments using the technique recommended by the manufacturer. Part 1 of this two‐part report describes the efficacy of the instruments in terms of preparation time, instrument failure, canal blockages, loss of canal length and three‐dimensional canal form. Overall, the mean preparation time for all canals was 6.01 min, with canal shape having a significant effect (P<0.01) on the speed of preparation. One instrument fractured and only four instruments deformed, with most of the failures occurring in canals with curves which began 12 mm from the orifice, that is, in short acute curves. None of the canals became blocked with debris. Following preparation, 20 canals retained their original working length but 19 lost length and one gained in length; there were significant differences (P<0.05) between the canal shapes in terms of mean loss of distance and in the category of distance change. Apical stops as determined from intracanal impressions were present in 37 of the canals; 16 were judged to be of good quality and 21 of poor quality. The canals were found to be smooth in the apical half of the canal in 33 specimens and in the coronal half of 39 specimens. All canals had good taper characteristics and 35 had good flow characteristics. Under the conditions of this study, NT Engine and McXim instruments prepared canals rapidly, with few deformations, no canal blockages and with minimal change in working length. The three‐dimensional form of the canals demonstrated good flow and taper characteristics.
Histological evaluation of a tooth with hyperplastic pulpitis and periapical osteosclerosis
Authors: ÇALIsKAN M. K. , TÜRKÜN M. , ÖZTOP F.
Published: November 2003

Histological examination was carried out in a case of hyperplastic pulpitis associated with periapical osteosclerosis.
The effects of sodium hypochlorite and calcium hydroxide on tissue dissolution and root canal cleanliness
Authors: TüRKüN M. , CENGIZ T.
Published: November 2003

In this in vitro study, we investigated the efficacy of sodium hypochlorite (NaOCl) and calcium hydroxide (Ca(OH)2) in dissolving necrotic tissue and cleaning root canals. In the first part of the study, 0.5% NaOCl solution and Ca(OH)2 paste and solution were tested with samples of necrotic bovine muscle in different treatment modes and for different periods. The necrotic tissue was weighed before and after the test and the percentage of weight change calculated. In the second part of the study, 40 extracted single‐rooted human teeth were hand instrumented and then subjected to different irrigation regimens. The cleansing efficacy in root canals of 0.5% NaOCl with Ca(OH)2 pretreatments and ultrasonics was examined using scanning electron microscopy. A solution of 5% NaOCl was significantly more effective than 0.5 % NaOCl as a solvent of necrotic tissue. Calcium hydroxide was an effective solvent for necrotic tissue as a paste but not as a solution. Pretreatment of necc tissue with Ca(OH)2 increased its solubility in 0.5% NaOCl. While 5% NaOCl plus ultrasonic irrigation produced cleaner root‐canal walls at the middle and apical thirds, 0.5% NaOCl used with the same technique achieved no root‐canal cleaning. However, pretreatment of root canals with Ca(OH)2 paste increased the effectiveness of 0.5% NaOCl plus ultrasonic irrigation, except in the coronal third of the root canal.
A model for the teaching of clinical techniques in root canal treatment
Authors: NATTRESS B. R. , MANOGUE M. , CARMICHAEL F.
Published: November 2003

A practical model to aid the understanding and practice of endodontic techniques is described. The model uses extracted teeth mounted in light‐cured acrylic resin and set in a preformed model tray. Before mounting, the root surfaces of teeth are dipped in wax to simulate the periodontal ligament space. This model allows endodontic techniques to be practised in the operative technique classroom in a way that simulates the clinical situation and enables radiographs of good diagnostic quality to be taken during treatment. Subsequently, teeth can be reset to allow restoration of the root‐filled tooth.
Incomplete calcium hydroxide removal from the root canal: a case report
Authors: RlCUCCI D. , LANGELAND K.
Published: November 2003

This case demonstrates failure of root canal treatment of a maxillary central incisor following incomplete mechanical removal of a Ca(OH)2intracanal dressing and subsequent resorption of the material from the apical portion of the root canal. Retrearment some 4 years later involved the removal of the contents of the root canal and permanent obturation by lateral condensation of cold gutta‐percha with a sealer. Follow‐up showed complete periradicular bone healing with a lamina dura evident. An explanation of the processes involved is offered, based upon histopathological and microbiological evidence in the literature.
Comparison of two endodontic handpieces during the preparation of simulated root canals
Authors: SMITH R. B. , EDMUNDS D. H.
Published: November 2003

The objective of this in vitro study was to compare and assess two endodontic handpieces during the preparation of simulated root canals. One hundred and sixty simulated root canals in clear resin blocks, of two angles and positions of curvature, were prepared using either Shaper files activated by the MM1500 Sonic Air handpiece (Micro‐Mega, Besançon, France)or Excalibur files activated by the W & H Excalibur 969 handpiece (W & H, Bürmoos, Austria). Files of 21‐mm or 25‐mm length were used. When preparing the canals, the files were used either in line with or perpendicular to the canal curvature. Preparation of the canals was carried out using a technique described in the manufacturers' literature. A variety of parameters were used to compare the handpieces, including an assessment of the canal preparation time, the deformation or fracture of instruments, loss of canal length, weight loss from the resin blocks and the overall postpreparation canal shape. Both handpieces provided an efficient and easy method of preparing and shaping the root canal with little operator fatigue. The MM1500 Sonic Air handpiece took significantly more time (P < 0.001) to prepare the canals and was associated with both more loss of working length (P < 0.05) and more loss of weight (P < 0.001). Both handpieces created a high percentage of aberrations in the shapes of prepared canals. The MM1500 Sonic Air handpiece created significantly more aberrations than the Excalibur handpiece (P <0.05 for zip and elbow, P < 0.05 for danger zone and coronal narrow). The effects of the variables, canal curvature, file length and the plane of use of the file, on the performance of the handpieces, were also assessed.
Arsenical necrosis of the jaws
Authors: BATAINEH A. B. D. , AL‐OMARI M. A. O. , OWAIS A. I.
Published: November 2003

After a brief historical review of the use of arsenic in dental practice two cases of arsenical necrosis of the jaws, affecting the maxilla and mandible respectively, are reported. Both patients were treated conservatively over an extended period with excellent results. It is concluded that there is no justification, whatsoever, for the use of arsenic in modern dental practice and that, although prolonged, conservative treatment of chemical necrosis of the jaws is preferable to more radical treatment.
Root canal treatment of a mandibular first molar with three mesial root canals
Authors: HOLTZMANN L.
Published: November 2003

The dynamic concept of the root canal system, describing a variable morphology of multiple root canals interconnected by anastomoses, has been established as the prevailing state in mandibular molars. This case report presents the treatment of a mandibular first molar with five root canals, of which three were located in the mesial root. A third middle root canal was found between the mesiobuccal and mesiolingual root canals. The morphological pattern of separate apical terminations of the three mesial root canals, as manifested in this case, is a very rare one and seldom encountered.
Reliability of different electronic apex locators to detect root perforations in vitro
Authors: KAUFMAN A.Y. , FUSS Z. , KEILA S. , WAXENBERG S.
Published: November 2003

The aim of this study was to evaluate the accuracy of the electronic apex locator Root ZX compared to the Sono Explorer Mark II Junior and Apit III in detecting root perforations. Extracted human teeth (n=30) were perforated artificially in the middle third of the root and embedded in a box containing alginate. Detection of all perforations were carried out with K‐files attached to the apex locators tested. The teeth were radiographed after each electronic measurement. The actual location of the tip of the file in relation to the external root surface and the radiographic determination of the perforations were carried out using a stereomicroscope. The mean distance of the tip of the file from the external outline of the root surface was short for all instruments and clinically acceptable(0.06–0.25 mm). There was no clinically significant difference between the morphometric measurements and the radiographic measurements. No statistical significance was found between large perforations (0.55–0.60 mm) and small perforations (0.25–0.40 mm). Under the conditions of this study, all electronic apex locators tested were acceptable clinical tools in the detection of root perforations.
The behaviour of post‐retained core materials supported by coronal tooth structure in vitro
Authors: RUSSELL M. D. , MASOOD M. , CUNNINGHAM L.
Published: November 2003

This study was designed to investigate the effect of retaining coronal tooth substance on the performance of post‐retained core materials, and to compare the fracture resistance of the system with an intact tooth prepared to similar dimensions. Ten teeth restored with post‐retained silver amalgam, and 10 teeth restored with silver‐glass cermet, all with a retained single wall of coronal tooth substance, were compared with 10 unrestored teeth prepared to similar dimensions when subjected to a shearing load. The results showed no statistically significant difference between the unrestored teeth and those restored with a silver‐glass cermet. Whilst the teeth restored with silver amalgam had a significantly higher fracture resistance (P > 0.01) there was greater tendency to root fracture.
Anin vitro investigation of coronal leakage with three guttapercha backfilling techniques
Authors: McROBERT A. S. , LUMLEY P. J.
Published: November 2003

The aim of this study was to compare the backfilling capabilities of System B, Obtura II and Alphaseal. Fortysix lower premolar teeth were prepared chemomechanically and allocated to four experimental and two control groups. Ten were obturated using lateral condensation as a standard and 30 were obturated in the apical third using the System B. The latter 30 teeth were then backfilled using one of three techniques, System B, Obtura II or Alphaseal (n=10 in each group). The remaining six teeth served as controls. Roots were radiographed from the proximal in order to evaluate voids and then placed in India ink for 65 h prior to being demineralized and rendered transparent, coronal leakage was quantified by linear measurement of ink penetration. No significant difference was found between the four groups with respect to the presence of voids radiographically (P<0.05). The difference in leakage between the System B and Obtura II groups was not significant (P<0.05). Both System B and Obtura II leaked significantly less than Alphaseal and lateral condensation (P0.001).
Age‐associated endocrine deficiencies as potential determinants of femoral neck (type II) osteoporotic fracture occurrence in elderly men
Authors: BOONEN S. , VANDERSCHUEREN D. , GEUSENS P. , BOUILLON R.
Published: November 2003

Osteoporotic fractures, and especially hip fractures, are a leading cause of morbidity and mortality among elderly men. Among other factors, a decline in bone mass has been identified as the major determinant of the age‐related reduction in bone strength and therefore of osteoporotic fracture risk. Recent evidence suggests that age‐associated endocrine deficiencies may contribute to femoral bone loss and hip fracture occurrence in elderly men. The decline in circulating androgen levels and the decreased activity of the growth hormone–insulin‐like growth factor‐I axis may result in a reduction in bone formation that contributes to the age‐related increase in bone fragility in men. Vitamin D deficiency‐induced secondary hyperparathyroidism, on the other hand, may further enhance bone loss by activating bone turnover and so increasing the number of bone remodelling units with impaired bone formation. On the basis of these pathophysiological models, guidelines can be developed for the prevention of age‐related bone loss in men, but these approaches lack validation. The results of controlled intervention trials will have to be awaited to answer the question of whether hormone replacement therapy attenuates bone loss and reduces fracture incidence in elderly men.
Estimating familial and genetic contributions to variability in human testicular function: a pilot twin study
Authors: HANDELSMAN D. J.
Published: November 2003

The biological basis for the remarkably wide variation in sperm output between and within men remains unclear. Although some contributing factors have been identified, the familial and genetic contributions to variation in human sperm output have been little studied, although such sources of variation are known to be significant in experimental animals. In order to identify such familial and genetic factors in a classical twin study design, we recruited monozygotic and dizygotic twins aiming to study the degree of resemblance between genetically identical and non‐identical twins in sperm output, testis size and testicular endocrine function. From an approach to 160 twin pairs on the Australian Twin Register database, eventually 17 pairs of male twins (11 monozygotic and six dizygotic) participated in this study. Sperm concentration and output, right testis size and SHBG all exhibited a strong familial effect but a genetic component could not be confirmed. Total and free testosterone exhibited a genetic component. Although identifying for the first time a clear familial component to normal human spermatogenesis, this study had insufficient power to determine whether there was a genetic component, nor could its design distinguish between genetic or shared (early) environmental determinants for these familial effects. Implications for future twin studies of human testicular function including stronger recruitment strategies, multicentre studies and surrogate variables for human spermatogenesis are suggested.
Semen analysis performed by different laboratory teams: an intervariation study
Authors: JØRGENSEN N. , AUGER J. , GIWERCMAN A. , IRVINE D. S. , JENSEN T. K. , JOUANNET P. , KEIDING N. , BON C. LE , MACDONALD E. , PEKURI A.‐M. , SCHEIKE T. , SIMONSEN M , SUOMINEN J. , SKAKKEBŒK N. E.
Published: November 2003

Some recent studies have indicated that sperm concentration has decreased during the last 50 years. However, comparisons between laboratories have revealed that geographical differences seem to exist and that any decrease may not be global. One point of criticism concerning comparison of results from different laboratories has been that some of the discrepancies detected could reflect the lack of standardized methods used in the different laboratories. Four teams, each consisting of one physician and one technician from groups which have recently published data on semen quality, met in order to evaluate the variability between their laboratories on semen analysis. Twenty‐six fresh semen samples from unselected men were analysed. The groups analysed the samples according to the normal practice in their laboratories, using their own equipment. The variation between laboratories was estimated through a random effects model. For sperm concentration and semen volume assessment a remarkable consistency between laboratories was detected, in contrast to the very considerable inter‐individual variation. For sperm motility and morphology assessments interlaboratory consistency was much poorer. In conclusion, evaluation of sperm motility and morphology characteristics requires further standardization in order to achieve comparable data from different laboratories. However, semen volume and sperm concentration are characteristics which can be compared reliably between laboratories, when similar methodologies are used.
Effect of tumour necrosis factor‐α (TNF‐α) and interferon‐γ (IFN‐γ) on human sperm motility, viability and motion parameters
Authors: ESTRADA L. S. , CHAMPION H. C. , WANG R. , RAJASEKARAN M. , HELLSTROM W. J. G. , AGGARWAL B. , SIKKA S. C.
Published: November 2003

Male genital tract infections and non‐specific inflammatory conditions may be associated with unexplained infertility. Previous studies have shown the presence of cytokines such as tumour necrosis factor‐α (TNF‐α) and interferon‐γ (IFN‐γ) in the semen of infertile men. However, the mechanism of effect of these cytokines on human sperm function is still controversial. The present study was undertaken to investigate the in‐vitro effects of TNF‐α and IFN‐γ on human sperm motion, viability and the hypoosmotic swelling test (HOST).

Washed spermatozoa from normal volunteers (n=9) were incubated in the presence/absence of TNF‐α (1 μg/mL) plus IFN‐γ (0.1 μg/mL). Sperm motility, viability, HOST, and video sequences were recorded at different time intervals (0, 30, 60 and 180 min). Sperm motion parameters were analysed using computer‐assisted semen analysis. There was a time‐dependent negative effect of TNF‐α plus IFN‐γ on sperm motility, viability, HOST, and lateral‐head displacement (ALH). The maximum decrease was observed between 60 and 180 min for sperm motility (50.8 ± 5.6%), viability (52.8 ± 4.0%), HOST (38 ± 2%) and ALH (4.7 ± 0.1 μm) compared to control samples (62.2 ± 2.8, 62.4 ± 2.9, 58 ± 4, and 5.3 ± 0.4, respectively; All p < 0.05). There was no significant effect on sperm straight‐line velocity and mean linearity when compared to control.

These data suggest that the common inflammatory cytokines TNF‐α plus IFN‐γ have only partial detrimental effects on sperm motility, viability, membrane integrity and lateral head displacement, which may contribute to the poor fertilizing potential of human spermatozoa during inflammatory conditions.
Antisperm antibodies in prepubertal boys treated with chemotherapy for malignant or non‐malignant diseases and in boys with genital tract abnormalities
Authors: SINISI A. A. , D'APUZZO A. , PASQUALI D. , VENDITTO T. , ESPOSITO D. , PISANO G. , DE BELLIS A. , VENTRE I. , PAPPARELLA A. , PERRONE L. , BELLASTELLA A.
Published: November 2003

In several childhood diseases which have the ensuing risk of infertility in adult life because of direct hypothalamic‐pituitary‐testicular axis involvement, or as a consequence of therapeutic toxicity, the role of antisperm antibodies (ASA) is rarely addressed. The aim of this study was to investigate the occurrence of ASA in a large prepubertal male population (aged 1.2–13 years) consisting of three groups: Group I, 52 patients affected by malignant diseases (lymphoblastic leukaemia, malignant lymphoma, or Wilm's tumour, n = 42), or by nephrotic syndrome (n = 10); Group II, 212 patients with either genital tract abnormalities (cryptorchidism, inguinal hernia, funicular torsion or hypospadias, n = 202), or cystic fibrosis (n = 10); Group III: 100 age‐matched normal boys. Group I and II patients were investigated at diagnosis and during or after treatment (drug, radiation or surgical therapy). Group III was used as controls. ASA were detected in sera by the Tray Agglutination Test (TAT) and indirect IgG, IgA and IgM immunobead tests (iIBT). All normal boys were ASA‐negative using both tests. Twenty‐six out of the 264 patients (9.8%) in Groups I and II were ASA‐positive: 23 (8.7%) patients had a positive TAT with a titre of 1:32 to 1:128, whilst 14 (5.3%) had IgG‐ASA after iIBT. Eleven patients (4.1%) were ASA‐positive in both tests. Of the 26 ASA‐positive boys, 24 had genital tract abnormalities (cryptorchidism, testicular torsion, hypospadias) and two had leukaemia with testicular infiltration. Treatment did not modify antibody positivity. Our data confirm that ASA can occur in prepubertal boys, mostly among cases with urogenital pathology, but that it is rare among other cases. Therefore autoimmune reaction against spermatozoa is another factor that should be considered in the evaluation of several conditions in childhood involving reproductive tract alteration and potential impairment of the blood testis (Sertoli cell) barrier.
Intracytoplasmic sperm injection using surgically retrieved epididymal and testicular spermatozoa in cases of obstructive and non‐obstructive azoospermia
Authors: FAHMY I. , MANSOUR R. , ABOULGHAR M. , SEROUR G. , KAMAL A. , TAWAB N. A. , RAMZY A. M. , AMIN Y.
Published: November 2003

This was a retrospective study of 115 patients who underwent 124 cycles of ICSI using surgically retrieved spermatozoa. The objective was to compare the results of ICSI in patients with obstructive azoospermia using epididymal spermatozoa (36 cycles) or testicular spermatozoa (58 cycles) with ICSI in patients with non‐obstructive azoospermia using testicular spermatozoa (30 cycles). When epididymal spermatozoa were used for ICSI, the fertilization rate per injected metaphase‐II oocyte and the clinical pregnancy rate per ICSI cycle were 60.4 and 25%, respectively. When testicular spermatozoa were used in obstructive cases, the fertilization rate and pregnancy rate were 57.9 and 34.5%. In non‐obstructive cases the fertilization and pregnancy rates were 41.2 and 16.6%. When patients with obstructive azoospermia were regrouped according to the cause of obstruction, the fertilization and pregnancy rates were 59.1 and 35.1% in acquired obstruction and 58.7 and 24.3% in congenital obstruction. The fertilization and pregnancy rates were not statistically different ( p > 0.05) when testicular or epididymal spermatozoa were used in obstructive cases; neither was statistically different ( p > 0.05) when compared in patients with congenital and acquired obstruction. On the other hand, the fertilization and pregnancy rates in cases with non‐obstructive azoospermia were significantly lower ( p < 0.05) than in obstructive cases.
Improved preservation of ultrastructural morphology in human spermatozoa using betaine in the primary fixative
Authors: SWAN M. A.
Published: November 2003

Improved preservation of the ultrastructural morphology of human spermatozoa was obtained by filtration onto a Millipore filter (0.45 μm pore size) followed by fixation for 1 h in a fixative containing 3% glutaraldehyde, 1% formaldehyde and 21 mM betaine in Hepes or cacodylate buffer. Betaine raised fixative osmolality only slightly but markedly improved the ultrastructural appearance of the spermatozoa; it is known to function as an osmoprotectant in other situations, and may protect the cells from osmotic damage during the initial stages of fixation.

The method is suitable for oligozoospermic samples as they are concentrated when the seminal plasma passes through the filter. Utilizing fixation after swim‐up, it is suitable also for highly viscous semen.

The fixative gave equally good preservation of sperm heads and tails and can be stored prior to use. The Millipore filter did not dissolve until placed in acetone prior to embedding, simplifying the exchange of solutions during processing. Improved preservation of rat epididymal ultrastructure was obtained by addition of betaine to the fixative of Ito & Karnovsky (1968), using immersion fixation.
Atrial natriuretic peptide, brain natriuretic peptide and c‐type natriuretic peptide: effects on testicular microcirculation and immunohistochemical localization
Authors: COLLIN O. , LISSBRANT E. , BERGH A.
Published: November 2003

The effect of local injection of atrial (ANP), brain (BNP) and C‐type (CNP) natriuretic peptides and an ANP antagonist (HS‐142–1) on testicular microcirculation and vasomotion was studied using laser Doppler flowmetry. The natriuretic peptides were also localized immunohistochemically within the testis.

ANP, BNP‐32, CNP‐22 and CNP‐53 all caused a dose‐related increase in testicular blood flow. The effect of ANP was blocked by concomitant injection of the ANP antagonist. Immunoreactive (ir) CNP and ir BNP were found in Leydig cells whereas ir ANP was observed in the seminiferous tubules. It is suggested that the natriuretic peptides could play a role in local regulation of the testicular microcirculation.
Prevalence and risk factors for anabolic‐androgenic steroid abuse in Australian high school students
Authors: HANDELSMAN D. J. , GUPTA L.
Published: November 2003

Abuse of anabolic‐androgenic steroids (AAS) is reportedly increasing in prevalence and spreading from sportsmen to cosmetic and recreational use, though there are few accurate estimates of the extent of AAS use outside North America. In order to identify the prevalence of, and risk factors for, `ever' (lifetime) or `recent' (within last month) use of AAS among Australian high school students, 13 355 students (51.3% male, median age 13.8 years) in 203 schools constituting a stratified random sample of all high schools in New South Wales and Victoria completed a self‐report questionnaire about drug use. Lifetime (`ever') use of AAS was reported by 213 boys (3.2%; 95% CI, 2.7–3.6%) and 74 girls (1.2%; 95% CI, 0.9–1.5%). Factors associated with `ever' use were truancy [ odds ratio (OR) 17.7 (95% CI, 9.4–31.6) for 7 or more truant days compared with no truancy over the last fortnight], unsupervised recreation [OR 8.4 (5.9–11.9) for 6 or more compared with 2 or fewer nights per week], speaking only a non‐English language at home [OR 7.75 (4.4–13.1)], Aboriginality [OR 3.4 (2.0–5.5)], male gender [OR 2.8 (2.1–3.7)], higher student income [OR 2.3 (1.7–3.0)], overseas born [OR 2.2 (1.6–3.0)] and low level of social support [OR 2.5 (1.7–3.5)]. Use of AAS within the last month (`recent') was reported by 113 boys (1.7%; 95% CI, 1.4–2.0%) and 28 girls (0.4%; 95% CI, 0.3–0.6%) and virtually identical risk factor patterns except ORs were uniformly higher. We conclude that AAS abuse is relatively uncommon among Australian high school students but has distinctive and strong socio‐economic and cultural predictors. Further studies of the behavioural epidemiology of AAS abuse are required to clarify the origins and significance of our findings and to identify potentially effective interventions.
Cell kinetics of repair after allyl alcohol‐induced liver necrosis in mice
Authors: LEE JAE HYUN , ILIC ZORAN , SELL STEWART
Published: November 2003

The cellular kinetics of repair and scarring which occurs after induction of periportal necrosis in mice by allyl alcohol were examined by histology and immunohistochemistry. Thirty‐six six‐week‐old female C57Bl/6J mice were injected intraperitoneally with two doses of allyl alcohol on day 0 and tissue sections were taken at various times and stained by haematoxylin and eosin or immunostained for proliferating cell nuclear antigen (PCNA), bile duct/oval cell marker A‐6, and DNA fragments (apoptosis). Within 6 hours, periportal necrosis was seen extending to produce large zones of confluent, pan‐acinar irregular necrosis, predominantly in the right and medial lobes with sparing of the left and caudate lobes. Restoration of liver mass was accomplished mainly by proliferation of mature hepatocytes in the surviving lobes of the liver (hyperplasia). In the right and medial lobes where necrosis was limited to the periportal zone, there was some, but much less, proliferation of small, oval periportal cells. The large necrotic zones in the right and median lobes shrank and were replaced by granulomatous inflammation. This cellular contribution of liver regeneration in the mouse was different from that previously reported in the rat and provides a means of inducing only a small proliferation of oval cells.
Preganglionic fibres of the adrenal medulla and cervical sympathetic ganglia: differential involvement during experimental American trypanosomiasis in rats
Authors: CAMARGOS E.R.S. , HAERTEL L.R.M. , MACHADO C.R.S.
Published: November 2003

The acute phase of experimental Chagas' disease in rats is associated with early lesions of the post‐ganglionic sympathetic nerve terminals of the heart, the varicosities being the target. In the superior cervical and stellate ganglia the preganglionic fibres showed no signs of lesion in the course of experimental Chagas' disease. In the adrenal medulla, however, the acute phase of the Trypanosoma cruzi infection induced a clear rarefaction of the acetylcholinesterase‐positive nerve fibres (20 and 32 days after infection). Recovery of the normal pattern occurred in most animals by day 125 after infection. At days 20, 32 and 46 after infection, electron‐microscopic studies demonstrated the occurrence of damage in cholinergic nerve terminals contacting the chromaffin cells. The signs of damage included dense bodies, clumps of synaptic vesicles and filaments, rarefaction of all organelles, vacuoles and irregular contour. The ultrastructural peculiarities of the sympathetic ganglia may explain the ganglionar microenvironment protective against the hazardous factors elicited by acute Chagas' disease.
Epithelial cell‐derived transforming growth factor‐β In bleomycin‐induced pulmonary injury
Authors: KUMAR RAKESH K. , O'GRADY ROSLYNN , MARONESE SONIA E. , WILSON MARK R.
Published: November 2003

We have investigated whether enhanced secretion of transforming growth factor‐β (TGF‐β) by distal respiratory epithelial cells was associated with the development of bleomycin‐induced pulmonary fibrosis. Type 2 pneumocyte‐enriched preparations of bronchioloalveolar epithelial cells from normal mouse lung tissue released latent TGF‐β when cultured in serum‐free medium. TGF‐β in culture supernatants could be detected using a sensitive enzyme immunoassay which employed enzyme complex amplification as a reporter system, as well as by a radiolabelled receptor competition assay. Exposure to bleomycin and other potentially fibrogenic stimuli in vitro did not stimulate production of TGF‐β by the epithelial cells but release was enhanced by treatment of the cells with interferon‐γ. Type 2 pneumocyte‐enriched cell preparations obtained following induction of a pulmonary inflammatory response by administration of intratracheal bleomycin to susceptible C57BL/6 mice did not demonstrate increased release of TGF‐β in culture. However, the concentration of TGF‐β in bronchoalveolar lavage (BAL) fluids was significantly elevated compared to controls at 1 and 2 weeks after bleomycin‐induced injury in these mice. No such increase was detected in BAL fluids from BALB/c mice, which are resistant to the effects of bleomycin. These results provide no support for a pathogenetic role of alveolar epithelial cell‐derived TGF‐β in bleomycin‐induced pulmonary fibrosis. Nevertheless, elevated levels of TGF‐β in BAL fluids may provide a marker of the progression of pulmonary injury to fibrosis.
The role of complement in the acute inflammatory process in the skin and in host–parasite interaction in hamsters inoculated with Leishmania (Leishmania) chagasi
Authors: LAURENTI M.D. , CORBETT C.E.P. , SOTTO M.N. , SINHORINI I.L. , GOTO H.
Published: November 2003

Tecidual reaction at the inoculation site of L. (L.)chagasi promastigotes in hamsters depleted and non‐depleted of complement was studied within 2, 6, 12, 24, 48 and 72 hours of infection. The inflammatory reaction was characterized by early predominance of polymorphonuclear cells (PMN) at 2, 6 and 12 hours of infection, mixed infiltrate of PMN and mononuclear cells (MN) at 24 hours, followed by predominance of MN at 48 and 72 hours after infection. The group depleted of complement showed a higher number of PMN at 2 hours and lower numbers of MN at 72 hours after infection (P<0.0001). In the depleted group the phagocytosis by PMN was lower at 2 and 24 hours and by MN was lower at 24, 48 and 72 hours after infection. Electron microscopy showed extracellular intact and degenerated parasites, and lysed intracellular parasites, in PMN; and, rarely, preserved intracellular parasites in MN at 2, 6 and 12 hours after infection. The groups examined at 24, 48 and 72 hours of infection showed only cellular and parasite debris in mononuclear inflammatory cells. C3b deposits were detected by immunofluorescence in the interstitium and in the cytoplasm of inflammatory cells in non‐depleted group at 2, 6 and 12 hours of infection. No immunoglobulin was detected in either group. Visceralization was detected 240 days after infection. The complement system has an important role in the inflammatory reaction and phagocytosis. The ultrastructural findings showed that the escape of the parasite probably occurs soon after inoculation.
Immunohistochemical characterization of thymic macrophages in normal and treated rats: a differential sensitivity to cyclosporine A
Authors: REZZANI R. , RODELLA L. , MILANESI S. , BIANCHI R.
Published: November 2003

In the present study, a set of two monoclonal antibodies (TRPM1, TRPM2) was used to investigate the macrophage populations in the rat thymus and their different sensitivities to cyclosporine‐A (CsA). With double immunohistochemical staining we demonstrated that, in the normal rat thymus, there are 3 populations of macrophages (TRPM1+, TRPM1/2+, TRPM2+), present in different proportions throughout the thymus. In the outer cortex TRPM1+ and TRPM1/2+ were present, but the TRPM1/2+ cells were more numerous. No TRPM2+ cells were observed in this area. The cortex and medulla showed all 3 types of cells with a majority of TRPM1/2+ cells. In the corticomedullary zone (CMZ) TRPM1/2+ and TRPM2+ macrophages were present in about equal proportion while only a few TRPM1+ cells were observed. After CsA treatment (for 21 days) profound changes occurred in the thymus; we observed a complete disappearance of the thymic medulla and a reduction in the total number of macrophages. The TRPM1+ macrophages had been eliminated, a few TRPM1/2+ cells were found while many of the cells were TRPM2+. The presence of the macrophages in different thymic areas suggests that they are a very heterogeneous population. The possible significance of the macrophage heterogeneity and the relationship to CsA sensitivity is discussed.
Transplantation of a human ovarian cystadenocarcinoma into severe combined immunodeficient (SCID) mice — formation of metastases without significant alteration of the tumour cell phenotype
Authors: Schumacher U. , Adam E. , Horny H.‐P. , Dietl J.
Published: November 2003

Human ovarian papillary cystadenocarcinoma cells were injected intraperitoneally into severe combined immunodeficient (SCID) mice. After intraperitoneal application the cells, designated SoTü, grew well in vivo, lodged on to the peritoneum, formed local metastatic deposits, led to the development of ascites in the mice and formed distant metastases in the lungs. If lodged in the ovary, the morphology of the SoTu¨ tumour remarkably resembled that of the primary tumour in the patient. In contrast, several attempts failed to maintain the SoTü cells in vitro. If SCID mouse ascites derived SoTü were transplanted subcutaneously in SCID mice, they formed cystic tumours which also metastasized into the lungs. Immunophenotypical analysis of cell adhesion molecule expression, cell proliferation markers, various oncoproteins, keratin, vimentin, and lectin binding site expression all showed striking similarity between the primary tumour and the SCID mouse explants. In particular, expression of binding sites for the lectin Helix pomatia agglutinin (HPA), which has been shown to be an index of metastatic potential in several human carcinomas, was found on the primary tumour as well as on tumour cells grown in SCID mice, indicating that HPA might be a prognostic indicator in ovarian carcinoma as well. Our results demonstrate that the human/SCID mouse system can mimic growth and distant metastasis formation of human ovarian carcinoma. Although the formation of distant metastases is a relatively rare event in patients, this model system might help to elucidate mechanisms of metastasis formation in ovarian cancer.
IN THE ABSENCE OF EPSTEIN‐BARR VIRUS INFECTION, PHORBOL ESTER MODULATES APOPTOSIS IN CYCLOHEXIMIDE‐TREATED BURKITT'S LYMPHOMA (BJA‐B) CELLS
Authors: Ishii Hideaki , Tamauchi Hidekazu , Gobé Glenda C.
Published: November 2003

We have shown previously that cycloheximide (CHX), a potent protein synthesis inhibitor, induces high levels of apoptosis in Epstein‐Barr virus free (EBV(−)) Burkitt’s lymphoma (BJA‐B) cells, with comparably reduced levels of apoptosis in the EBV positive (EBV(+)) cells. Modulation of CHX‐induced apoptosis in EBV(−) and (+) B cells is reported here using concurrent treatment with phorbol ester (phorbol 12,13‐dibutyrate, PdBu). Cells were collected at 0, 3, 6, 12, 24 and 48 hours after treatment with (i) 1 μg/ml CHX, (ii) 0.1 μg/ml PdBu (1 hour pretreatment before 0 h), or (iii) CHX + PdBu (CHX added at 0 h, 1 hour after PdBu). Control cultures were untreated. Apoptotic, necrotic or viable cells were quantified using histological, ultrastructural and biochemical parameters. Protein synthesis was assessed using 35S‐methionine incorporation. Intracellular calcium concentrations were measured using flow cytometry. PdBu alone had little effect on cell death. High levels of CHX‐induced apoptosis in EBV(−) cells were significantly reduced by concurrent addition of PdBu (P < 0.005). In contrast, low levels of CHX‐induced apoptosis in EBV(+) cells were not significantly altered by PdBu treatment. In EBV(−) cells, a negative relationship was observed between levels of apoptosis and calcium concentrations, whereas in EBV(+) cells, there was negligible correlation between these parameters. Thus high levels of CHX‐induced apoptosis in EBV(−) cells occur via a PKC‐dependent pathway, whereas CHX treatment of EBV(+) cells induces comparatively low levels of apoptosis that occur via a PKC‐independent mechanism. The results application in the therapeutic intervention for cancers developing in association with EBV infection.
In situ analysis of ischaemia/reperfusion injury in rat liver studied in three different models
Authors: STRAATSBURG IRENE H. , FREDERIKS WILMA M.
Published: November 2003

Animal models of liver ischaemia and reperfusion are frequently used to study the consequences on liver cells of transient oxygen deprivation. In 3 different rat models we studied ischaemia/reperfusion effects on liver cell membrane integrity, cytoplasmic enzyme proteins and enzyme activities by in situ histochemical techniques. In vivo ischaemia, as well as no‐flow hypoxia, or N2‐induced hypoxia in isolated perfused livers, reduced the activity of 5′‐nucleotidase, a sensitive marker for plasma membrane damage in hepatocytes. As little as 2 minutes of reoxygenation in each model resulted in leakage of soluble enzymes from parenchymal and non‐parenchymal liver cells, as shown by decreased protein level and activity of cytoplasmic enzymes. Whereas a multifocal decrease was observed after in vivo reperfusion, a decrease was found in all periportal and midzonal cells after blood‐free reoxygenation. As judged by alkaline phosphatase activity and immunohistochemistry, an influx of inflammatory cells was not found in the in vivo model. Our findings indicate that reoxygenation itself, rather than restoration of flow, accounts for the loss of soluble enzymes from liver cells after a period of hypoxia. In situ detection of enzyme protein and activity proved useful for the examination of very early ischaemia/reperfusion effects on rat liver cells.
Abnormal development and differentiation of macrophages and dendritic cells in viable motheaten mutant mice deficient in haematopoietic cell phosphatase
Authors: NAKAYAMA KEI‐ICHIRO , TAKAHASHI KIYOSHI , SHULTZ LEONARD D. , MIYAKAWA KAZUHISA , TOMITA KIMIO
Published: November 2003

In mice homozygous for the ‘viable motheaten’ (mev) mutation, numbers of macrophage progenitor cells, particularly monocytes, were markedly increased in the bone marrow and spleen. Increased mobilization of these precursor cells to peripheral tissues and their differentiation to macrophages were evidenced by striking increases in macrophage numbers. Immunohistochemical double staining of tissue sections and flow cytometry analyses of single cell suspensions from these mice demonstrated CD5 (Ly‐1)‐positive macrophages in the peritoneal cavity, spleen and other tissues. Ly‐1‐positive macrophage precursor cells were demonstrated in the peritoneal cavity of the mev mice and developed in the omental milky spots. The development of marginal metallophilic and marginal zone macrophages was poor in the splenic white pulp and related macrophage populations were absent in the other lymphoid tissues. The numbers of epidermal Langerhans cells in the skin and T cell‐associated dendritic cells in the thymic medulla, lymph nodes, and the other peripheral lymphoid tissues were decreased. However, increased numbers of dendritic cells accumulated in the lungs, liver, and kidneys. These abnormalities in development and differentiation of macrophages and dendritic cells may be ascribed to the deficiency in haematopoietic cell SHP‐1 tyrosine phosphatase or may be a secondary consequence of abnormal microenvironments, (either constitutive or in response to inflammatory stimuli) in the haematopoietic and lymphopoietic organs and tissues of these mice.
Ultrastructure of rat lung following inhalation of ricin aerosol
Authors: BROWN R. F. R. , WHITE D. E.
Published: November 2003

Ricin is one of a group of structurally related plant lectins and is extracted from the seeds of the Castor Oil plant, Ricinus communis.

Groups of rats were exposed to ricin aerosol by inhalation, total LCt1 = 11.21 mg.min.m−3 (an approximate LCt30 exposure) and examined, using transmission electron microscopy, at intervals up to 48 h after exposure.

The first signs of change in ultrastructure were seen at between 6 and 12 h post exposure in alveolar macrophages and took the form of apoptotic changes primarily in the nucleus. These included heterochromatin condensation at the nuclear periphery and crenulation of the nuclear membrane. There then followed a sequence of changes in the cells of the alveolar wall and blood/air barrier culminating in intra‐alveolar oedema at 12 and 15 h after exposure.

Damage was first observed in the capillary endothelium and type I epithelial cell changes were evident from 12 h post exposure onward. These changes appeared to be necrotic rather than apoptotic in nature and suggest that mechanisms other than a direct effect of ricin may be involved.

Associated with these changes were mixed inflammatory cell infiltrates in the interstitium, isolated type II pneumocyte necrosis and evidence of microvascular microthrombosis. By 48 h after exposure, the intra‐alveolar oedema appeared less marked with prominent hyperplasia of type II pneumocytes.

The identification that apoptosis of alveolar macrophages plays a significant part in the mechanism of toxicity following exposure to ricin raises the possibility of developing new therapeutic strategies against poisoning by ricin.
Pathogenesis of schistosomal ‘pipestem’ fibrosis: a low‐protein diet inhibits the development of ‘pipestem’ fibrosis in mice
Authors: COUTINHO E. M. , DE SOUZA M. M. , SILVA L. M. , CAVALCANTI C. L. , DE ARAUJO R. E. , BARBOSA Jr. A. A. , CHEEVER A. W. , ANDRADE Z. A.
Published: November 2003

Mice maintained on a low protein diet for 30 days and then infected with Schistosoma mansoni for 16 weeks completely failed to develop ‘pipestem fibrosis’ of the liver, whereas 50% of well nourished controls did. Usually mice with relatively mild and prolonged S. mansoni infection develop two different pathological pictures: one consisting of disseminated portal fibrosis caused by periovular granulomas concentrated at the portal spaces (pipestem fibrosis), the other represented by scattered hepatic granulomas. The reason for this dual response is poorly understood. Combined results from parasitological, histopathological, biochemical and morphometric data revealed that peri‐ovular granulomas of undernourished mice were smaller, inflammation was less intense and there was minimal fibrosis in comparison with those of controls, which suggest that a vigorous host response is necessary for the pathogenesis of schistosomal portal fibrosis.
Vacuolar cytoplasmic phase separation in cultured mammalian cells involves the microfilament network and reduces motional properties of intracellular water
Authors: HENICS TAMÁS , WHEATLEY DENYS N.
Published: November 2003

Hep‐2, human epithelial carcinoma cells, and human foreskin fibroblasts (FF9 and FF13) were exposed to either an ultrafiltrate (< 50 kD) of human sera or the weak base, procaine hydrochloride, to induce reversible cytoplasmic vacuolization. The formation of vacuoles was shown not to be due to imbibition of medium. Ultrastructural details obtained from various stages of vacuole formation were compared. In both cases of induction vacuoles were irregular and often appeared membraneless, with little in the way of electron‐dense content. They started to form in the perinuclear cytoplasm and progressed towards the periphery. Osmotic stress was not involved since mitochondria remained normal throughout a vacuolization episode.

Vacuoles were often seen in close contact with filamentous structures, and this association remained detectable at late stages of the phenomenon. Fluorescent visualization of F‐actin confirmed that the vacuoles were frequently bordered by microfilaments. No major metabolic impairment was apparent in vacuolized cells as judged by protein synthesis measurements, but nuclear fluorescence (DNA content) and forward light scatter (nuclear volume) by flow cytometric analysis suggested late S phase and G2 retardation. 1H‐nmr relaxation measurements indicated intracellular water restricted in motional characteristics in vacuolized cells. The possibility of a restricted cytoplasmic phase separation as part of a transient adaptation response is raised, and a hypothesis to explain the findings is discussed.