bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison of two nickel–titanium instrumentation techniques in teeth using microcomputed tomography
Authors: Rhodes J. S. , Ford T. R. Pitt , Lynch J. A. , Liepins P. J. , Curtis R. V.
Published: March 2003

Aim  The aim of the study was to compare the shaping of root canals by two nickel–titanium instrumentation techniques using microcomputed tomography (MCT).

Methodology  Ten mandibular first molar teeth (30 canals) that had intact crowns and fully formed roots were scanned using MCT. Fifteen canals were instrumented using NiTiFlex hand files (Maillefer) using balanced force. The remainder were instrumented using prototype ProFile 0.04 Taper instruments (Dentsply) in a crown‐down manner to an apical size ISO 25. The teeth were scanned again following instrumentation. The two instrumentation techniques were compared in a total of 27 canals. The area of dentine removed at pre‐determined levels (2.0, 3.0, 4.5, 6.0, 7.5 mm) from the apex was measured. Transportation and centring were recorded. Images constructed at these levels were compared with video images of equivalent physical sections created after the second scan. The volume of dentine removed in the apical 7.5 mm of the root canals of each tooth was calculated and the different techniques compared. Rendered three‐dimensional images were used to assess the preparations qualitatively. The time taken for preparation was recorded.

Results  There was no significant difference between hand instrumentation with NitiFlex files and machine instrumentation with prototype ProFile 0.04 Taper instruments for any of the variables tested.

Conclusions  Both techniques produced well centred and tapered preparations.
Computerized infrared thermographic imaging and pulpal blood flow: Part 2. Rewarming of healthy human teeth following a controlled cold stimulus
Authors: Kells B. E. , Kennedy J. G. , Biagioni P. A. , Lamey P. J.
Published: March 2003

Aim

To investigate the rewarming pattern and rewarming rate of clinically healthy teeth following a controlled cold stimulus using TI techniques.

Methodology

A controlled cold stimulus was developed using an air stream at 20 °C. Gingival and incisal sites on 12 healthy maxillary lateral incisors in six patients were imaged under rubber dam following 20 s cooling. Images were captured at 10 s intervals during a 3‐min rewarming period and the data used to construct graphs of the rewarming rate. Log transformation of the data was used to produce ‘best fit’ straight line graphs. Linear regression analysis was used to examine three variables, viz. the side of the mouth (right or left), the site of measurement (gingival or incisal) and the phase of rewarming (early 0–90 s, late 91–180 s).

Results

The mean temperature change (Δt °C) during rewarming was 8.5 °C (SD 1.0 °C) for gingival sites and 7.2 °C (SD 1.1 °C) for incisal sites. The slope of the ‘best fit’ straight line data enabled a rewarming index to be calculated for each site on each tooth. Linear regression analysis showed that the phase of rewarming was highly significant but the other variables were not. A one‐way anova showed no significant differences between or within groups.

Conclusions

Three min is an appropriate time to record rewarming of teeth cooled for 20 s with an airstream at 20 °C. The side or site used to record surface temperatures using this technique is not significant. Rewarming is exponential and log transformation of the data produces a well‐fitting straight line graph. The slope of this line provides a rewarming index which should enable comparison of TI and laser Doppler flowmetry in determining pulpal blood flow as a measure of tooth vitality.
Computerized infrared thermographic imaging and pulpal blood flow: Part 1. A protocol for thermal imaging of human teeth
Authors: Kells B. E. , Kennedy J. G. , Biagioni P. A. , Lamey P. J.
Published: March 2003

Aim

To observe the thermographic appearance of teeth and to develop a suitable protocol for imaging teeth in human subjects using modern thermographic imaging (TI) equipment in a thermologically controlled environment.

Methodology

The emissivity of enamel was investigated using an extracted incisor tooth. A total of 12 unrestored maxillary lateral incisors in six healthy patients were then imaged under rubber dam after a 20‐min equilibration period and the thermographic data analysed using a dedicated software package. Recordings were made from standardized gingival and incisal sites on each tooth and the temperature gradient established for each tooth. Subsequently, a sequence of images of both maxillary central incisors in one patient was stored every 30 s during a 20‐min equilibration period with and without an air‐conditioning unit in operation.

Results

For the lateral incisors there was a consistent temperature gradient (mean 1.28 °C) from gingival area to incisal area and there were no statistically significant differences between right and left sides for the gingival site (t = 0.34, NS) or the incisal site (t = 0.62, NS). The air‐conditioning unit had a rapid and profound cooling effect. With the air‐conditioning disabled there was a mean tooth surface temperature increase of 1.1 °C from 0 to 5 min of the equilibration period and 0.3 °C from 15 to 20 min.

Conclusions

There was no significant difference in gingival or incisal temperatures between pairs of contralateral maxillary lateral incisors and a consistent temperature gradient existed from gingival to incisal areas of healthy maxillary lateral incisor teeth. The protocol described is suitable for TI of vital teeth. However, TI measured tooth surface temperature only which was extremely sensitive to air currents. A 15‐min acclimatization period under rubber dam was adequate to allow stable tooth surface temperature measurement.
Shaping ability of Hero 642 rotary nickel–titanium instruments in simulated root canals: Part 2
Authors: Thompson S. A. , Dummer P. M. H.
Published: March 2003

Aim

To determine the shaping ability of Hero 642 nickel–titanium rotary instruments during the preparation of simulated canals.

Methodology

A total of 40 simulated root canals made up of four different shapes, in terms of angle and position of curvature, were prepared by Hero 642 instruments using a crown‐down preparation sequence. Pre‐ and postoperative images of the canals were taken using a video camera attached to a computer with image analysis software. The pre‐ and postoperative views were superimposed to highlight the amount and position of material removed during preparation. This report describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation and overall postoperative shape.

Results

Four zips and four elbows were created during preparation, all in canals with 40°, 12 mm curves. No perforations or danger zones were created. Highly significant differences (P < 0.001) were apparent between the canal shapes in total canal width at the apex and beginning of the curve, and in the amount of resin removed from the inner and outer aspects of the curve at the orifice. Canal transportation was most frequently directed toward the outer aspect of the curve at specific points along the canal, except at the orifice, where it was apparent that canals with 20° curves transported toward the inner. Overall, mean absolute transportation was always less than 0.15 mm; however, significant differences occurred between canal shapes at the end‐point (P < 0.01), apex of the curve (P < 0.01) and at the orifice (P < 0.01).

Conclusions

Under the conditions of this study, Hero 642 rotary nickel–titanium instruments created canals with few aberrations and no perforations. The relatively high proportion of aberrations in canals with short, acute curves may indicate that instruments with increased taper should be used with caution at or near the full working distance. Further research in real teeth is necessary to elucidate the full potential of these new rotary instruments for use in root canal preparation.
Complications during root canal irrigation – literature review and case reports
Authors: Hülsmann M. , Hahn W.
Published: March 2003

Literature review and case reports

The literature concerning the aetiology, symptomatology and therapy of complications during root canal irrigation is reviewed. Three cases of inadvertent injection of sodium hypochlorite and hydrogen peroxide beyond the root apex are presented. Clinical symptoms are discussed, as well as preventive and therapeutic considerations.
Mandibular first molar with three distal root canals
Authors: Kimura Y. , Matsumoto K.
Published: March 2003

Case report

A right mandibular first molar requiring root canal treatment was found to have one mesial and two distal roots and a total of five canals. The mesial and distobuccal root had two separate canals; the distolingual root had one. This case demonstrates a rare anatomical configuration and supplements previous reports of the existence of such configurations in mandibular first molars.
Pulpal response to prolonged dentinal exposure to sodium hypochlorite
Authors: Tang H.‐M. , Nordbö H. , Bakland L. K.
Published: March 2003

Aim

The aim of this study was to examine the effect of undiluted NaOCl on vital pulp tissue when applied to freshly cut dentine.

Methodology

Class V cavities were prepared to a depth of 2 mm in 20 teeth in four Beagle dogs. The cavities on one side of each dog were irrigated continuously for 5 min with 5.25% NaOCl, whilst the cavities on the opposite side in each dog were irrigated with saline for the same length of time. Prior to filling each cavity with Cavit, they were again rinsed with saline and gently dried with an air stream. The dogs were sacrificed to allow for investigation of pulpal conditions under the cavities after periods of 24 h, 1 week, and 4 weeks. Histological preparations were made and stained with H & E for evaluation of the pulp subjacent to each cavity. The tissues were examined for presence of inflammatory cells and categorized as (i) no inflammation, (ii) mild, (iii) moderate, and (iv) severe inflammation.

Results

The six teeth in the 24 h observation group all showed mild inflammation, both in the NaOCl and the saline groups. After 1 week and 4 weeks, the pulps from all the teeth were free of inflammatory cells.

Conclusion

Under the conditions of this experiment, the use of NaOCl in a freshly cut cavity in an intact tooth of a dog, with exposed dentinal tubules, does not appear to cause additional pulpal damage to that caused by the physical contact in cutting tooth structure.
Cyclic fatigue of ProFile rotary instruments after prolonged clinical use
Authors: Gambarini G.
Published: March 2003

Aim

The purpose of the present study was to evaluate resistance to cyclic fatigue of new and used ProFile Ni–Ti rotary instruments.

Methodology

Used instruments were operated in 10 clinical cases using passive instrumentation and a crown‐down preparation technique. Cyclic fatigue testing of new and used engine‐driven instruments was then performed with a specific device which allowed the instruments to rotate freely inside a stainless steel artificial canal, whilst maintaining conditions close to the clinical situation. Instruments were rotated until fracture occurred and time to fracture was visually recorded with a chronometer.

Results

A significant reduction of rotation time to breakage (life span) was noted between new and used instruments. In all sizes new instruments were significantly more resistant than used ones (two‐sample t‐test, P < 0.01). No instrument underwent intracanal failure during clinical use.

Conclusions

Prolonged clinical use of Ni–Ti engine‐driven instruments significantly reduced their cyclic fatigue resistance. Nevertheless, each rotary instrument was successfully operated in up to 10 clinical cases without any intracanal failure.
An in vitro study comparing root‐end cavities prepared by diamond‐coated and stainless steel ultrasonic retrotips
Authors: Peters C. I. , Peters O. A. , Barbakow F.
Published: March 2003

Aim

This study compared the appearance of root‐end cavity preparations and the time required to prepare them using prototype ultrasonic diamond‐coated (DC) and stainless‐steel (SS) retrotips.

Methodology

In 12 maxillary and 12 mandibular molar teeth 48 root‐end cavities were prepared ultrasonically in the palatal, mesio‐buccal, distal and mesial root‐ends using DC and SS retrotips, alternately. Replicas of the resected root tips and the root‐end cavities were examined under a scanning electron microscope (SEM), recording (i) incidence and extent of dentine cracks (ii) minimum remaining thickness of the dentine walls and (iii) surface quality of the resected root‐ends. The time taken to complete the preparation was also recorded. Means of these parameters were compared for both types of retrotips using nonparametric tests.

Results

No resected root‐ends had cracks before preparation. However, after preparation one root‐end cavity shaped by an SS retrotip had a microcrack visible at 23× magnification. Four and seven other root‐ends had crazed surfaces in the DC and SS groups, respectively (P > 0.05). Remaining minimum dentine thickness was 0.56 ± 0.28 mm and 0.71 ± 0.24 for the DC and SS groups, respectively, and this difference was significant (P < 0.05). A root‐end cavity in one specimen in the DC group was perforated. Preparation times ranged from 25 s to 361 s and were significantly lower for DC tips (P < 0.01) than the SS tips. The time required to prepare root‐end cavities also differed between roots; root‐end preparation in mandibular molars was more time consuming.

Conclusion

s A better quality surface was produced by the prototype diamond‐coated retrotips, in less time than the SS retrotips, which in turn caused fewer cracks than previously reported. DC retrotips removed more dentine than SS retrotips and should therefore be used with care to avoid overpreparation or perforation.
The histological effects of four endodontic sealers implanted in the oral mucosa: submucous injection versus implant in polyethylene tubes
Authors: Figueiredo J. A. P. , Pesce H. F. , Gioso M. A. , Figueiredo M. A. Z.
Published: March 2003

Aim

The aim of this study was to evaluate pigmentation and tissue response to four endodontic sealers placed in the oral mucosa of rabbits by either submucous injection or implant in polyethylene tubes.

Methodology

Thirty white New Zealand rabbits were divided randomly into two groups of eight for N‐Rickert and AH‐26, and two groups of seven for Fillcanal and Sealer 26. On the right side of the filter, corresponding to the gingivo‐labial sulcus in humans, the sealer was injected; on the left side the sealer was placed within a polyethylene tube and implanted. Direct clinical observations were made at 30, 60 and 90 days. The animals were then sacrificed for histological analysis.

Results

After 60 days of observation N‐Rickert and AH‐26 produced tattoos that became larger by 90 days. Submucous injection produced larger and more numerous pigmentation, when compared to implant in polyethylene tubes. N‐Rickert sealer displayed larger and more numerous tattoos when compared to AH‐26. Histological analysis showed no differences between the two methods of implantation. All sealers elicited some kind of inflammatory response; the most irritant was Fillcanal, followed by N‐Rickert and AH‐26. Sealer 26 elicited a mild reaction only.

Conclusions

Under the conditions of this study there was no relationship between the method of implantation and the tissue response; the silver‐containing sealers produced pigmentation, and the concentration of silver influenced the quantity and size of the tattoos. The sealers elicited various responses when in direct contact with the surrounding tissues; the calcium hydroxide‐containing sealer had enhanced healing when compared to the other sealers.
An in vitro investigation of the bulk flow of fluid through apical foramina during simulated tooth extraction: a potential confounder in microbiological studies?
Authors: Kapalas A. , Spratt D. A. , Ng Y‐L. , Gulabivala K.
Published: March 2003

Aim The ‘pumping action’ induced during tooth extraction may cause bacteria suspended in tissue fluids to be transposed from one anatomical compartment to another. Apart from causing bacteraemia, this may lead to inaccuracies in studies evaluating the presence and distribution of bacteria in and around tooth apices. The aim was to investigate the bulk flow of fluid through apical foramina during simulated extraction of teeth in an in vitro model. The influence of the presence or absence of a coronal restoration was also evaluated.

Methodology Twenty extracted single‐rooted, human, mature, permanent teeth were used. Standard access cavities were prepared and the root canals located. Standardized micrographs of the apical foramina were obtained and their area (µm2) was calculated by image analysis software. The teeth were then set and sealed into polyvinylsiloxane (rubber base) impression material. Crystal violet dye was inoculated into the coronal half of the root canal system. Tooth extraction movements were simulated in the impression matrix and the leakage of dyes with and without the presence of a coronal restoration was examined. The procedure was repeated, following application of safranin dye in a coronal trough within the simulated rubber base gingival margin at the CEJ. The results were analysed statistically with the independent‐samples t‐test and the McNemar test.

Results In the absence of a coronal restoration crystal violet leaked out of the apical foramina in 18/20 teeth; conversely safranin leaked into the teeth through the apical foramina in 11/20 cases when applied to the external root surface. In the presence of an intact coronal restoration crystal violet dye leaked out in 6/20 teeth and conversely safranin leaked into 7/20 teeth. The presence of a coronal restoration significantly reduced (P = 0.002) dye leakage out of the root canal system. No associations were found for leakage of dye into the root canal system when applied externally. In addition, the amount of dye leakage was positively correlated with the area of the apical foramen in the presence of a coronal restoration (P = 0.009).

Conclusion The presence of a coronal restoration significantly reduced leakage of dye out of the apical foramen. Microbiological studies on root canals and periapical lesions using extracted teeth should take potential contamination from this source into account.
An in vitro comparison of three thermal gutta percha systems
Authors: Horrocks M. P. , Qualtrough A.
Published: March 2003

Aim The aim of this study was to compare the ability of three contemporary obturation techniques to resist microleakage, using root canals prepared in extracted single rooted teeth by a standardized method.

Methodology The shaping technique involved the use of tapered nickel titanium rotary files to create a uniform 0.08‐mm/mm taper. Six groups were compared, two representing control groups, a third group being obturated with a warm vertical condensation technique, a fourth group by an injection thermoplasticized system, a fifth group with a thermomechanical compaction method and a sixth group using cold lateral condensation. A zinc oxide/eugenol sealer was used as the sealant in all the obturation procedures. Forty‐six extracted teeth were used in the study, three teeth in each control group and 10 teeth in each of the remaining four groups. Microleakage was compared using dye leakage with Indian ink. Penetration of the dye at the gutta percha/dentine interface was visualized after the root had been rendered transparent. Dye leakage was then measured from four aspects with the use of a stereomicroscope and export of a digital image to a software package, to facilitate accurate assessment of dye penetration. Two parameters were measured for each sample, the mean dye penetration and maximum dye penetration.

Results The mean values for linear dye leakage in the thermomechanical compaction group was 0.53 mm, the warm vertical condensation group was 0.73 mm, the injection thermoplasticized group was 0.15 mm and the cold lateral condensation group was 0.53 mm. There was no statistical difference between the means of the different groups (P > 0.05). The mean of the maximum values for dye leakage in the thermomechanical compaction group was 0.65 mm, the warm vertical condensation group was 1.02 mm, the injection‐thermoplasticized group was 0.28 mm and the cold lateral condensation group was 0.74 mm. There was no statistical difference between the means of the different groups (P > 0.05).

Conclusions Within the conditions of this study, there was no statistical difference between the different groups with respect to either mean or maximum dye leakage.
The dentinogenic effect of mineral trioxide aggregate (MTA) in short‐term capping experiments
Authors: Tziafas D. , Pantelidou O. , Alvanou A. , Belibasakis G. , Papadimitriou S.
Published: March 2003

Aim The objective of the present experiment was to study the early pulpal cell response and the onset of reparative dentine formation after capping application of MTA in mechanically exposed pulps.

Methodology Thirty‐three teeth from three dogs, 12–18 months of age were mechanically exposed via class V cavities. Light pressure was applied to control haemorrhage. ProRoot MTA (Dentsply Simfra, Paris) was placed at the exposure site and light pressure was applied with a wet cotton pellet. The cavities were restored with amalgam and the pulpal tissue reactions were assessed by light and electron microscopy (transmission and scanning) after healing intervals of 1, 2 or 3 weeks.

Results A homogenous zone of crystalline structures was initially found along the pulp–MTA interface, whilst pulpal cells showing changes in their cytological and functional state were arranged in close proximity to the crystals. Deposition of hard tissue of osteotypic form was found in all teeth in direct contact with the capping material and the associated crystalline structures. Formation of reparative dentine (tubular matrix formation in a polar predentine‐like pattern by elongated polarized cells) was consistently related to a firm osteodentinal zone.

Conclusions The present experiments indicate that MTA is an effective pulp‐capping material, able to stimulate reparative dentine formation by the stereotypic defensive mechanism of early pulpal wound healing.
Incompletely fractured teeth associated with diffuse longstanding orofacial pain: diagnosis and treatment outcome
Authors: Brynjulfsen A. , Fristad I. , Grevstad T. , Hals‐Kvinnsland I.
Published: March 2003

Aim To evaluate the diagnostic value of different clinical findings, and analyse the symptoms experienced from teeth with incomplete dentinal fractures in patients with diffuse orofacial pain. Secondly, to present the outcome of different treatment modalities in these patients.

Methodology Thirty‐two patients, referred to the teaching clinic at the Faculty of Dentistry, University of Bergen, with poorly localized orofacial pain, were finally diagnosed with 46 incompletely fractured teeth. The distribution and pattern of pain was thoroughly recorded for each patient. The final diagnosis, incompletely fractured tooth, was obtained after removal of fillings and direct inspection of possible fracture lines.

Results Many of the patients had suffered diffuse orofacial pain for more than 1 year, and had earlier consulted dental and medical expertise. Direct inspection of fracture lines, combined with staining solution and transillumination proved to be the best diagnostic tools. The longer the duration of pain before the diagnosis of an incompletely fractured tooth was established, the more diffuse was the distribution of pain. Endodontic or restorative treatment relieved the symptoms in 90% of the patients, whilst persisting symptoms in 10% were considered part of an orofacial pain complex of obscure aetiology.

Conclusion This study shows that the diagnosis of the incompletely fractured teeth in patients with longstanding diffuse orofacial pain symptoms are time consuming and represent a diagnostic problem. With appropriate endodontic and/or restorative treatment, symptoms were relieved in the majority of cases.
Evaluation of a spectrophotometric assay for the measurement of malondialdehyde and 4‐hydroxyalkenals in human spermatozoa: relationships with semen quality and sperm function
Authors: GOMEZ  , IRVINE  , AITKEN
Published: March 2003

A spectrophotometric assay for the measurement of malondialdehyde and 4 hydroxyalkenals (MA + 4HA) has been evaluated for the detection of sperm pathologies involving oxidative stress. In order to make sensitive measurements of MA + 4HA on human spermatozoa, the stimulation of a lipid peroxidation cascade with a ferrous ion promoter was found to be necessary. The optimal configuration for the promoter was defined (0.64 m M FeSO4 + 20 m
M ascorbate for 2 h in Ca2+ and Mg2+ free Hanks' balanced salt solution) and the assay used in a series of studies to elucidate the functional significance of MA + 4HA determinations. Such measurements were found to give highly significant correlations ( p < 0.001) with the loss of motility induced by oxidative stress created either with a xanthine oxidase, free radical generating system or by prolonged incubation under aerobic conditions. Experiments involving the stimulation and suppression of lipid peroxide release from human sperm suspensions, in concert with a bioassay for cytotoxicity, confirmed the strength and causative nature of these associations. Measurements of lipid peroxidation potential in highly purified, leucocyte‐free sperm suspensions revealed the presence of inverse correlations with the motility of the spermatozoa, their viability, their competence for sperm‐oocyte fusion and, most significantly, the quality of sperm movement in the original semen samples. Similar negative correlations were observed between sperm function and phorbol ester‐stimulated reactive oxygen species generation but, unlike the MA + 4HA determinations, these relationships were obfuscated by the presence of leucocytes. We conclude that the measurement of MA + 4HA in human spermatozoa provides important information on the underlying quality of spermatogenesis and should be of value in the clinical diagnosis of infertility involving oxidative stress and the selection of patients for antioxidant therapy.
pH of human semen
Authors: HAUGEN  , GROTMOL
Published: March 2003

The World Health Organization (WHO) laboratory manual (1992) states the normal values for pH in liquefied semen to be between 7.2 and 8.0. This implies an adjustment compared with the previous version (WHO, 1987) in which the upper limit was 7.8, whereas in theWHO clinical manual (1993) the normal range of values is still stated to be in the range of 7.2–7.8. In this study pH was measured in ejaculates from 207 men in couples undergoing infertility examination. The pH was measured within 30 and 60 min after ejaculation with both pH paper and pH meter. The mean pH values were consistently well above 8.0 regardless of analysis method and time after ejaculation. Since semen analysis is part of clinical assessment of male infertility and includes pH measurement, our findings suggest that the range of normal values needs to be revised further.
A matter of death and life: the significance of germ cell death during spermatogenesis
Authors: BLANCO‐RODRÍGUEZ
Published: March 2003

The significance of cell death occurring during spermatogenesis is a subject of interest because of its potential medical importance. Unfortunately, the field has been difficult for andrologists to penetrate, in part because of the difficulties of studying germ cells in vitro and the complexity of designing suitable models in which to dissect the molecular signalling pathways involved in control of germ cell apoptosis. As a result, the reasons for these deaths remain unclear despite considerable investigative effort. As developments which have occurred over the last few years in understanding of apoptosis can shed light on this important topic, this review focuses on what is currently known about germ cell apoptosis and outlines the emerging picture of what might be the causes and biological role of germ cell deaths in spermatogenesis.
A re‐appraisal of the post‐testicular action and toxicity of chlorinated antifertility compounds
Authors: JONES  , COOPER
Published: March 2003

Some 30 years ago, α‐chlorohydrin and some analogues were considered as close to the ideal contraceptive which acted rapidly and reversibly on the post‐testicular maturation of spermatozoa. Despite their early promise, research funding was withdrawn only 5 years later because of what were considered to be unacceptable side‐effects in primates. The literature on the toxic effects of these contraceptive agents was reviewed and was found to be wanting in respect to the rigour of scientific methods applied (impure compounds were used, inappropriate target populations were studied, excessive doses were employed, abstracts were cited from which no full publications subsequently arose). These compounds remain the closest approach yet to non‐hormonal contraceptives for males and have led to the synthesis of related compounds which have a similar antifertility action but with much diminished toxicity. If toxicity remains a problem, a range of other compounds now known to have a similar antifertility action, should be investigated.
Lack of sexual activity from erectile dysfunction is associated with a reversible reduction in serum testosterone
Authors: Jannini Emmanuele A. , Screponi Emiliano , Carosa Eleonora , Pepe Mario , Lo Giudice Francesco , Trimarchi Francesco , Benvenga Salvatore
Published: March 2003

The role of androgenic hormones in human sexuality, in the mechanism of erection and in the pathogenesis of impotence is under debate. While the use of testosterone is common in the clinical therapy of male erectile dysfunction, hypogonadism is a rare cause of impotence. We evaluated serum testosterone levels in men with erectile dysfunction resulting either from organic or non‐organic causes before and after non‐hormonal impotence therapy. Eighty‐three consecutive cases of impotence (70% organic, 30% non‐organic, vascular aetiology being the most frequent) were subjected to hormonal screening before and after various psychological, medical (prostaglandin E1, yohimbine) or mechanical therapies (vascular surgery, penile prostheses, vacuum devices). Thirty age‐matched healthy men served as a control group. Compared to controls, patients with impotence resulting from both organic and non‐organic causes showed reduced serum levels of both total testosterone (11.1 ± 2.4 vs. 17.7 ± 5.5 nmol/L) and free testosterone (56.2 ± 22.9 vs. 79.4 ± 27.0 pmol/L) (both p < 0.001). Irrespective of the different aetiologies and of the various impotence therapies, a dramatic increase in serum total and free testosterone levels (15.6 ± 4.2 nmol/L and 73.8 ± 22.5 pmol/L, respectively) was observed in patients who achieved normal sexual activity 3 months after commencing therapy (p < 0.001). On the contrary, serum testosterone levels did not change in patients in whom therapies were ineffective. Since the pre‐therapy low testosterone levels were independent of the aetiology of impotence, we hypothesize that this hormonal pattern is related to the loss of sexual activity, as demonstrated by its normalization with the resumption of coital activity after different therapies. The corollary is that sexual activity may feed itself throughout the increase in testosterone levels.
Genetic screening for patients with azoospermia and severe oligo‐asthenospermia
Authors: Chiang Han‐Sun , Wei Hsiao‐Jui , Chen Yu‐Tzu
Published: March 2003

In order to explore the genetic defects of patients with azoospermia or severe oligo‐asthenospermia, screening examinations were carried out for the chromosome disorder and gene deletion of the Y chromosome for 220 male infertility patients. The present results show that the total prevalence of genetic defects is 23.6%, including 38 patients (28.4%) with chromosome disorder and 14 patients (16.8%) with gene deletion in the Yq arm. The most prevalent chromosome anomaly is 47XXY (Klinefelter’s syndrome), which includes 18 cases of pure type and three cases of mosaic type. Variable autosomal translocations occurred in both the azoospermia group (5.2%) and the oligo‐astheno‐spermia group (5.8%) with similar prevalence. A total of 22 patients had deletions of the variable, interstitial portion of the Yq arm. These gene deletions are distributed not only inside the AZF region, but also outside of this region. The severity of deletions is not well correlated to the clinical testicular function of the patients. We conclude that chromosome disorder and gene deletions are the causative factors of patients with azoospermia and oligo‐asthenospermia. Genetic screening should be a routine examination for them before the use of assisted‐reproductive technologies.
Clinical‐pathological comparison of clinical prostate cancer between Japanese Americans in Hawaii and Japanese living in Japan
Authors: Fukagai Takashi , Shimada Makoto , Yoshida Hideki , Namiki Thomas , Carlile Robert G.
Published: March 2003

In an attempt to determine the role of environmental factors in the etiology of prostate cancer, we compared the clinical‐pathological findings of prostate cancer among Japanese Americans in Hawaii and Japanese living in Japan. Our study showed that prostate cancer in Japanese living in Japan is more advanced than in Japanese Americans. The findings indicate that screening for prostate cancer in Japan is far behind that in the USA. The difference in level of cancer screening also precluded our attempt to analyse environmental factors contributing to prostate cancer progression in the two groups. The variation in method of clinical detection of prostate cancer between the USA and Japan is also likely to contribute to the apparent difference in the incidence of the disease.
Evidence for the presence of 5′‐deiodinase in mammalian seminal plasma and for the increase in enzyme activity in the prepubertal testis
Authors: Brzezińska‐Ślebodzińska  , Ślebodziński  , Kowalska
Published: March 2003

Thyroid hormones are critical for structural and functional development of the testis and Sertoli cells are considered true target cells for triiodothyronine (T3). However, the role of thyroid hormones in the adult testis seems to be minimal and the mechanism by which they affect testicular function is not known. Due to the existing blood–testis barrier the concentration of thyroid hormones in seminal plasma is kept lower than in blood plasma. We have found that T3 may reach the testis not only from the circulation but also from local enzymic conversion of thyroxine to T3. The presence of the enzymic activity responsible for thyroxine 5′deiodination and for generating T3 locally was also found in boar’s seminal plasma. The seminal plasma 5′‐deiodinase (5′‐D) appeared to be predominantly the propylthiouracil (PTU)‐insensitive type II isoenzyme found, so far, in tissues where it plays a role in paracrine signalling. It contains selenocysteine in its molecule (inhibition by aurothioglucose), and has an apparent Km for reverse‐T3 as substrate of 0.36 n
M and a Vmax 23.8 fmol I–/mg protein/min. Because the seminal plasma 5′‐D is partially, but uncompetitively, inhibited by PTU, the presence in seminal plasma of two 5′‐D isoenzymes (type I and II) cannot be excluded. The 5′‐D activity in testes increased significantly between week 3 and 4, and this increase was concomitant with increase in testicular size. The relationship between testicular weight gain and age showed a similar characteristic change and corresponded to the change in 5′‐D activity. Unlike in rodents, the testis of the prepubertal pig has thyroid hormone receptors in Sertoli cells, and suggests that in growing piglets, testicular 5′‐D is a key factor regulating local supply of biologically active T3, and is an essential factor in testicular paracrine function. The present results are the first demonstration and characterization of the 5′‐deiodinase in seminal plasma.
Immunohistochemical localization of V‐ATPases in rat spermatids
Authors: Kawa Gen , Yamamoto Akitsugu , Yoshimori Tamotsu , Muguruma Koei , Matsuda Tadashi , Moriyama Yoshinori
Published: March 2003

The sperm acrosome exhibits a low pH. However, the mechanism of acidification in the acrosome remains unclear. Vacuolar‐type proton ATPase (V‐ATPase) has been shown to play a principle role in generating and maintaining the acidity of organelles such as lysosomes and endosomes. In this study, we examined whether V‐ATPase is localized in the acrosome membranes using immunohistochemical techniques.

Sections of rat testis were immunostained using antibodies against V‐ATPase. Under light microscopic observation, the perinuclear region in spermatids at an early stage of development was heavily immunostained. At the electron microscopic level, gold particles showing the presence of V‐ATPase were localized to the acrosome membranes in the developing spermatids. V‐ATPase was also localized to the membrane of vesicles locating between the trans‐Golgi area and the acrosome. These observations suggest that V‐ATPase may play a role in acrosome acidification.
Infancy is not a quiescent period of testicular development
Authors: Chemes Héctor E.
Published: March 2003

Postnatal evolution of the testis in most laboratory animals is characterized by the close continuity between neonatal activation and pubertal development. In higher primates, infancy, a long period of variable duration, separates birth from the beginning of puberty. This period has been classically considered as a quiescent phase of testicular development, but is actually characterized by intense, yet inapparent activity. Testicular volume increases vigorously shortly after birth and in early infancy due to the growth in length of seminiferous cords. This longitudinal growth results from active proliferation of infantile Sertoli cells which otherwise display a unique array of functional capabilities (oestrogen and anti‐müllerian hormone secretion, increase of FSH receptors and maximal response to FSH). Leydig cells also show recrudescence after birth, possibly determined by an active gonadotrophic‐testicular axis which results in increased testosterone secretion of uncertain functional role. This postnatal activation slowly subsides during late infancy when periodic phases of activation of the hypothalamo‐pituitary‐testicular axis are paralleled by incomplete spermatogenic spurts. The beginning of puberty is marked by the simultaneous reawakening of Leydig cell function and succeeding phases of germ cell differentiation/degeneration which ultimately lead to final spermatogenic maturation. The marked testicular growth in this stage is due to progressive increase at seminiferous tubule diameter. Sertoli cells, which have reached mitotic arrest, develop and differentiate, establishing the seminiferous tubule barrier, fluid secretion and lumen formation, and acquiring cyclic morphological and metabolic variations characteristic of the mature stage. All of these modifications indicate that, far from being quiescent, the testis in primates experiences numerous changes during infancy, and that the potential for pubertal development and normal adult fertility depends on the successful completion of these changes.
A new objective method for scoring human sperm hyperactivation based on head axis angle deviation
Authors: Mazzilli Fernando , Rossi Tiziana , Delfino Michele , Dondero Franco , Makler Amnon
Published: March 2003

The aims of the present study were, first to develop a new method for evaluating sperm hyperactivation (HA) based on sperm head axis angle deviation, and second to apply this method in scoring selected sperm populations during capacitation. This was made possible by improving our original superimposed image analysis system (SIAS). The new option on the system enables us to determine the real angular deviation of the entire head in successive superimposed frames. The entire procedure for each spermatozoon requires 10–20 sec, according to the frame/rate utilized. A clear cut‐off between the values of hyperactivated, transitional and non‐hyperactivated spermatozoa was found at 11 and 21 frames/sec. However, at 6 frames/sec, a partial overlap between the three classes was found. We defined sperm activity as follows. At 11 frames/sec, hyperactivated: angle sum ≥ 405°; transitional: 200° ≤ angle sum < 405°. At 21 frames/sec, hyperactivated: angle sum ≥  760°; transitional: 350° ≤ angle sum < 760°. The results, in agreement with previous research, show the peaks of activity at 3 h, dropping to a minimum at 6 h. This phenomenon was significantly more evident in fertile compared with subfertile semen samples.
cAMP response element modulator (CREM): an essential factor for spermatogenesis in primates?
Authors: Behr R. , Weinbauer G. F.
Published: March 2003

CREM is a cAMP‐related transcription factor and alternate promotor usage and splicing generate repressor and activator transcripts of CREM within the testis. CREM activators are highly expressed in post‐meiotic haploid germ cells and are essential for spermatid maturation in the mouse model as revealed by gene‐targeting studies. Analysis of testicular CREM expression in rodent and monkey species, and in men yielded a highly comparable pattern thus suggesting that CREM is of general importance for spermatid development in the mammalian testis. Also, many CREM target genes have been identified in haploid germ cells. Studies in men with spermatogenic disturbance and spermatid maturation arrest demonstrated abnormal CREM expression and altered splicing events. Collectively, the data strongly argue for an essential role of CREM during spermatid maturation in primates.
Lectin affinity of the seminiferous epithelium in healthy and cryptorchid post‐pubertal boars
Authors: Pinart E. , Bonet S. , Briz M. , Pastor L. M. , Sancho S. , García N. , Badia E. , Bassols J.
Published: March 2003

The present study describes the sugar content of the seminiferous epithelium, using lectin histochemistry, in healthy boars and in boars with unilateral and bilateral abdominal cryptorchidism. In healthy boars the apical cytoplasm of Sertoli cells exhibited abundant glucosyl (Con A and WGA lectins), galactosyl (HPA, DBA, SBA and PNA lectins), and fucosyl (AAA lectin) residues. Spermatogonia and spermatocytes contained abundant glucosyl (Con A and WGA lectins) and fucosyl (AAA lectin) residues. In spermatids, galactosyl (SBA and PNA lectins) and glucosyl (Con A and WGA lectins) residues increased progressively throughout spermiogenesis, and fucosyl (AAA lectin) residues decreased. As compared with healthy boars, the scrotal testis of unilateral cryptorchid boars showed decreased amounts of fucosyl (AAA lectin) and galactosyl (HPA and DBA lectins) residues on the Sertoli cell apical cytoplasm; spermatocytes exhibited higher content of glucosyl (Con A lectin) residues and spermatids showed altered nature of glucosyl (Con A and WGA lectins) and galactosyl (SBA and PNA lectins) complexes. In abdominal testes of unilateral and bilateral cryptorchid boars, immature Sertoli cells and spermatogonia showed decreased fucosyl (AAA lectin), and increased glucosyl (Con A and WGA lectins) and galactosyl (SBA and PNA lectins) contents. These results suggest that the seminiferous epithelium of healthy boars has polarized activity with the apical compartment implicated in germ cell–Sertoli cell adhesion and interaction, in transport of ions, substrates and fluids, and in acrosomal differentiation. In scrotal testes, unilateral abdominal cryptorchidism could lead to defective germ cell–Sertoli cell adhesion, impaired acrosomal differentiation and increased ionic transport in the apical compartment of the seminiferous epithelium. Unilateral and bilateral cryptorchidism could induce increased ionic transport and membrane permeability in the seminiferous epithelium of abdominal testes.
Seasonal changes in spermatogenic activity and in plasma levels of FSH, LH and testosterone, and the effect of immunization against inhibin in the male silver fox (Vulpes vulpes)
Authors: Berg K. Andersen , Wiger R. , Dahl E. , Torp T. , Farstad W. , Krogenæs A. , Mcneilly A. S. , Paulenz H. , Ropstad E.
Published: March 2003

The cellular composition of the silver fox testis assessed by DNA flow cytometry and histological analysis exhibited marked circannual alterations. The proportion of haploid cells increased from late October to the breeding season in February, while that of diploid cells decreased and that of tetraploid cells fluctuated during the same period. Towards the end of March these changes were reversed. The seasonal variations in testicular histology paralleled the changes in distribution of cells from the different DNA populations. In August, 69% of the tubules contained spermatogonia as the only type of germ cell, while the remaining 31% also contained a few primary spermatocytes. In late October more than 50% of the tubules contained spermatocytes, and during the period of further activation from early December–February the seminiferous epithelium included round and/or elongated spermatids as well. In February, all tubules contained complete associations of germ cells, whereas in late March tubules with spermatogonia only and spermatogonia together with a few spermatocytes reappeared. In May, only such tubules could be found indicating total regression. Plasma concentrations of FSH and LH increased from early November, both gonadotrophins reaching maximum levels in December or early January, and then both declined during the second part of January, immediately prior to the actual breeding season. LH values showed a few smaller peaks in the beginning of June, whereas FSH levels were generally low until the next period of testicular reactivation. Testosterone concentrations were also low during most of the year but rose in November and December to reach a peak in January and a second peak in June. In animals immunized against inhibin the distribution of haploid, diploid and tetraploid cells did not deviate to any great extent from that in the controls, except in March when the immunized males had a markedly lower proportion of tetraploid cells, and in May, when they had a distinctly higher proportion of haploid cells. These findings were partly reflected by the histology. In the immunized animals, plasma FSH levels started to increase at approximately the same time but peaked higher and remained elevated almost 1 month longer than in the controls, whereas both the rise and decline in LH levels generally coincided with the variations in these animals, but the values were mostly higher. The testosterone profiles were similar to those in the controls except that the maximum values were also usually higher.