Heterogeneity in regional changes in body composition induced by androgen deprivation therapy in prostate cancer patients: potential impact on bone health-the BLADE study.

BACKGROUND: It is not clear whether changes in body composition induced by androgen deprivation therapy (ADT) in prostate cancer (PC) patients are uniform or vary in the different body districts and whether regional lean body mass (LBM) and fat body mass (FBM) could have an impact on bone health. OBJECTIVE: To prospectively evaluate the regional changes in LBM and FBM in PC patients submitted to degarelix; to explore the relationship of regional body composition and bone mineral density (BMD) and bone turnover markers. DESIGN, SETTING, AND PARTICIPANTS: 29 consecutive non metastatic PC patients enrolled from 2017 to 2019. FBM, LBM and bone mineral density (BMD) evaluated by dual-energy x-ray absorptiometry (DXA) at baseline and after 12-month of ADT. Alkaline phosphate (ALP) and C-terminal telopeptide of type I collagen (CTX) assessed at baseline, 6 and 12 months. INTERVENTION: All patients underwent degarelix administration. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: T-test or sign test and Pearson or Spearman test for continuous variables were used when indicated. RESULTS AND LIMITATIONS: Median percent increase in FBM ranged from + 14.5% in trunk to + 25.4% in the left leg after degarelix. LBM changes varied from + 2% in the trunk to - 4.9% in the right arm. LBM in both arms and legs and their variations after degarelix directly correlated with ALP and inversely correlated with CTX. Lean mass of limbs, trunk and legs significantly correlated with BMD of the hip, lean mass of the trunk significantly correlated with spine BMD. These are post-hoc analysis of a prospective study and this is the main limitation. CONCLUSIONS: an heterogeneous change in body composition among body district is observed after ADT and bone turnover is influenced by lean mass and its variation. A supervised physical activity is crucial to maintain general physical performance and preserving bone health.

Unusual giant complex odontoma: A case report.

Odontomas are benign, non-aggressive, and the most common odontogenic tumor of the jaws. Composed of dental tissues, it can be classified as compound or complex odontomas depending on their radiological and histological features. Among them, complex odontomas are less common and usually is presented as a small and asymptomatic radiopaque mass surrounded by a radiolucent halo, found on routine radiographic examination. Although benign tumors, odontomas can reach large sizes leading to facial asymmetry and decreasing bone strength, which predisposes fractures and infection. Our aim was to present a case report of an unusual giant mandibular odontoma on the left mandibular angle and ramus successfully treated by surgical excision and highlight the importance of the earlier diagnostic to minimize damages.

Combination of electrochemical biosensor and textile threads: A microfluidic device for phenol determination in tap water.

Microfluidic devices constructed using low cost materials presents as alternative for conventional flow analysis systems because they provide advantages as low consumption of reagents and samples, high speed of analysis, possibility of portability and the easiness of construction and maintenance. Herein, is described for the first time the use of an electrochemical biosensor for phenol detection combined with a very simple and efficient microfluidic device based on commercial textile threads. Taking advantages of capillary phenomena and gravity forces, the solution transportation is promoted without any external forces or injection pump. Screen printed electrodes were modified with carbon nanotubes/gold nanoparticles followed by covalent binding of tyrosinase. After the biosensor electrochemical characterization by cyclic voltammetry technique, the optimization of relevant parameters such as pH, potential of detection and linear range for the biosensor performance was carried out; the system was evaluated for analytical phenol detection presenting limit of detection and limit of quantification 2.94nmolL-1 and 8.92nmolL-1 respectively. The proposed system was applied on phenol addition and recovery studies in drinking water, obtaining recoveries rates between 90% and 110%.

Knowledge and behaviour of nursing students on the prevention of healthcare associated infections.

INTRODUCTION: Hospital infections, or "healthcare associated infections" (HAI) represent the most common and serious complications of healthcare. Adoption of safe care practices able to prevent or control the transmission of infections, both in hospitals and in other healthcare settings is crucial. The aim of the study is to assess the awareness about the risk factors and the most effective measures of prevention of HAI in the University of Ferrara nursing school students, giving particular attention to the hand hygiene practices and the use of standard precautions. METHODS: 339 students attending all the three years of course of the same academic year were enrolled. An anonymous questionnaire was administered in order to investigate the knowledge about three specific areas: infections associated with healthcare practices (HAI), standard precautions (SP) and hand hygiene (HH). RESULTS: A sufficient level of knowledge by all the three groups of students was observed only in the SP area. A barely sufficient score was reached only by the third year students with regard to the proper HH. The level of knowledge about HAI was inadequate. CONCLUSIONS: A periodically check of nursing students' knowledge would be advisable in order to fill any gaps, improve training, reduce HAI and increase prevention measures compliance.

[Do controlled ovarian hyperstimulations and cryopreservations promote recurrences after breast cancer?] / Les hyperstimulations contrôlées et les cryopréservations ovariennes favorisent-elles la rechute après cancer du sein ?

The objective of this review was to identify recurrences (ipsilateral, contralateral, metastases and deaths) occurring after controlled ovarian hyperstimulation (COH) or cryopreservation of ovarian tissue (CPTO) for patients treated for a breast cancer. METHODS: We performed a bibliographical research through the Pubmed/Medline database, including all the references from January 2006 until September 2016, in French or in English, after exclusion of animal studies. The keywords association "breast neoplasms", "fertility preservation", "reproductive techniques", "ovarian cryopreservation" and "in vitro fertilization" allowed the selection of 852 publications among which only 6 were selected because they included data on recurrence and long term follow up. Four publications involved HSC (3 before breast cancer treatment and 1 after) and 2 concerned CPTO with re-implantation. RESULTS: This analysis has not shown increasing of breast recurrences after HSC and CPTO. However, results were not statistically significant, due to several biases in particular heterogeneousness of the groups of patients. CONCLUSION: A survey of patients who used fertility preservation or assisted reproductive technologies after breast cancer would be helpful to better estimate their oncological risk.

Risk perception of sexually transmitted diseases and teenage sexual behaviour: attitudes towards in a sample of Italian adolescents.

The aim of the study is to determine awareness about sexually transmitted diseases (STDs) and their prevention in people aged 14-19 of Ferrara and province. The study was carried out using a self-administered standardised anonymous questionnaire in a sample of students attending to three upper secondary schools. Total number of collected questionnaires was 2695, the average age of interviewed was 17.1. Only 52.3% of respondents correctly recognized STD definition. Over 95% of subjects identified acquired immune deficiency syndrome (AIDS), while properly classification of Hepatitis B increased with age and lowest degree of knowledge concerned herpes infection and Candidiasis. Sex without condom (95.97%) and needle exchange in drugs abusers (94.9%) are considered high risk behaviours. 80.3% of interviewed, without distinction of school attendance, sex, and age considered lack of information as a situation of high risk. Condoms are not used by 46.4% of the subjects in case of sex with a regular partner and by 9.5% with casual partner. Majority of students declared condoms very safe in preventing STDs but an important percentage indicated also contraception methods; correct answers were higher among females and increased with age. Main sources of information were TV (21.6%), school (21.1%) and friends (14.8%) and a few sought information from family doctor (7.4%) and web (4.8%). The study suggests, as priority, to improve teenagers' awareness about risk behaviours and prevention of STDs. School can play an important role in reinforcement of sexual education programmes and directing young people to general practitioners and primary sexual health care services.

Suspension of mandatory vaccination and public health preserving: Rovigo local health unit experience after appliance of Veneto regional law 7/2007.

The burden of infectious diseases preventable by vaccination decreased considerably over last decades in all countries provided with effective immunization schedules. Implementation of these programs with new vaccines has started discussion on duality between mandatory and recommended vaccinations. Regional autonomy has allowed the Veneto Region, with introduction of Law 7/2007, to experience suspension of all mandatory childhood vaccinations, replaced by an active and free offer of all vaccines recognized as safe and effective. Coverage's trends and acceptance of invitation are carefully monitored to avoid loss of compliance and reduction of immunized children. The evaluation, performed on population of Rovigo ULSS18 for 2002-2008 birth cohorts (2008 is the first concerned by the change), revealed no fall for previously mandatory vaccinations, but rather a slight increase. Percentage of non-vaccinated children was negligible. The leading cause of non-vaccination to polio was inability to deliver the letter of invitation due to wrong address. An informed dissent was expressed only by a minority (0.9% in 2008 birth cohort). Compliance to immunization offer was elevated both for previously compulsory and recommended vaccinations. Experience of Rovigo ULSS 18 showed that, in a context of already high levels of coverage for recommended vaccinations with optimal organization of immunization services, coverage rates for ex-mandatory vaccines remain unchanged. Further research and reports are required to carefully assess the effect on coverage rates in next birth cohorts, but available data are encouraging. Similar legislative measures can be successfully adopted by other Regions with starting conditions comparable to Veneto Region.

Citrus leprosis virus C Naturally Infecting Commelina benghalensis, a Prevalent Monocot Weed of Citrus Orchards in Brazil.

There are two bacilliform, rhabdo-like viruses that cause citrus leprosis: Citrus leprosis virus C (CiLV-C), which accumulates in the cytoplasm of infected cells, and Citrus leprosis virus nuclear type (CiLV-N), which accumulates in their nucleus. The first one, the prototype of the new genus Cilevirus, is prevalent and occurs in several countries of the American continent, from Argentina to Mexico (1). The second type, still a tentative member of the Rhabdoviridae family, is of rare occurrence, with a few reports in Brazil and one in Panama (1). Leprosis is particularly important to the Brazilian citrus industry because of the 60 to 80 million dollars spent yearly for the control of Brevipalpus phoenicis (Geijskes, 1939) (Acari: Tenuipalpidae), the vector of the virus (1). For decades, the disease was considered unique to citrus plants; however, greenhouse experiments conducted in the 1990s demonstrated the mechanical transmission of CiLV-C to noncitrus plants (1). Years later, researchers were able to transmit the virus to nonrutaceous hosts using viruliferous mites (1,4). Recently, León et al. (2) reported the occurrence of the first noncitrus plant naturally infected by CiLV-C, the rutaceous Swinglea glutinosa Blanco (Merr.). Tropical spiderworts (Commelina benghalensis L.; Commelinaceae) are monocot weeds commonly found in citrus orchards in Brazil. In a survey conducted in orchards with high incidences of leprosis in the municipalities of Borborema and São José do Rio Preto, State of Sao Paulo, Brazil, tropical spiderworts were found exhibiting necrotic spots with a yellow halo in green leaves and green spots with necrotic center in senescent leaves. Since these symptoms are similar to those caused by CiLV-C in citrus, symptomatic plants were collected and subjected to transmission electron microscopy analyses and reverse transcription-PCR using primers that specifically amplify a region within the putative movement protein gene of the virus (3). Bacilliform virus particles and typical inclusions were seen in the lesions. Bands of the expected 344 bp size were seen in agarose gels of symptomatic samples only. The analysis of the consensus sequence showed 100% identity with CiLV-C sequence available in the GenBank (Accession No. YP_654542.1). Experimental transmission of CiLV-C by B. phoenicis reproduced the lesions in inoculated tropical spiderwort. Also, the virus could be easily transmitted back from C. benghalensis to sweet orange plants. Our data show that this widespread weed is the first monocot as a natural host for CiLV-C. Since tropical spiderwort is a host for B. phoenicis and symptomatic plants were found in two municipalities 130 km apart from each other, it is possible that this weed may serve as reservoir for the virus and play a relevant role in the spread of the disease in the field, but this issue still needs to be addressed in further experiments. References: (1) M. A. Bastianel et al. Plant Dis. 94:284, 2010. (2) M. G. A. Leon et al. Plant Dis. 90:682, 2008. (3) E. C. Locali-Fabris et al. Plant Dis. 87:1317. (4) M. A. Nunes et al. Plant Dis. Online publication. doi:10.1094/PDIS-06-11-0538, 2011.

Effect of selected antihypertensives, antidiabetics, statins and diuretics on adjunctive medical treatment of glaucoma: a population based study.

BACKGROUND: The prevalence of open angle glaucoma increases with age, with many patients also receiving medications for non-ocular systemic diseases. Little is known about how systemic medications impact on the need for adjunctive therapy with prostaglandin analogues (PGA). OBJECTIVES: To evaluate whether systemic medications for hypertension, cholesterol, or glucose influence the need for adjunctive intraocular pressure (IOP) lowering medications in patients using PGAs. METHODS: Pharmaceutical records from the Québec prescription database provided a sample of patients receiving prescriptions for bimatoprost, latanoprost, or travoprost, from which subjects receiving > or =1 prescription for antihypertensives, antidiabetics. diuretics, and statins were identified. Chi-square tests compared proportions using PGAs to those using PGAs + adjunctive therapy, based on the use or non-use of systemic medications; a logistic regression was performed post hoc to adjust for gender and age. RESULTS: Of the 8548 evaluated patients (all using PGAs); 2934 (34.3%) took none of the studied systemic drugs. For the 5614 patients taking systemic medications, significantly fewer (p < 0.001) required an additional IOP lowering medication if taking a systemic antihypertensive medication. The use of a statin or a diabetic medication, alone or in combination, in addition to a PGA, made no significant difference in the need for adjunct glaucoma therapy. Individual drugs associated with significantly less utilization of adjunctive glaucoma medications were calcium-channel blockers, angiotensin-converting enzyme (ACE), and combination antihypertensive therapies. DISCUSSION: A profound association between systemic antihypertensive use and a reduced need for adjunct topical IOP lowering medications in patients using the same prostaglandin analogue for at least one year was found. LIMITATIONS: The use of a prescription claims database without patient compliance or patient outcomes may not reflect actual patient medication use. In addition, these findings may not be applicable to all patients initiating prostaglandin analogues. CONCLUSIONS: In this real-world population-based evaluation, a significant association exists between using systemic antihypertensive medications and reduced use of adjunctive IOP lowering therapies. These results confirm findings from previous studies suggesting an IOP lowering effect with systemic agents or some synergy with topical therapies.

Knowledge of preventive measures against occupational risks and spread of healthcare-associated infections among nursing students. An epidemiological prevalence study from Ferrara, Italy.

INTRODUCTION: Exposure to biological agents is the most common occupational risk for nursing staff. This study verified changes in attitudes and knowledge occurred in the nursing students after the first year of degree. METHODS: The survey was conducted in academic year 2006/07 among the students of the Professional Nursing Course at University of Ferrara (Italy) using a structured questionnaire. Students were 85 at the beginning and 80 at the end of the courses. RESULTS: The rate of subjects using gloves for intramuscular injections and fingertip puncture was unsatisfactory. A high percentage of students performed recap of needles. The use of gloves in case of washing of surgical instruments was high. The compliance in the use of gloves in handling test tubes remained low. Only 2/3 of the students washes their hands coming in ward. Incorrect attitudes have been observed in changing or wearing gloves. The students considered vaccination against hepatitis-B necessary, vaccination against flu unnecessary. A high percentage of students had not performed any prophylaxis for tuberculosis. DISCUSSION: Students intend the use of gloves mainly to perform self-protection. The concept of self-protection is contradicted by the large percentage of students that recap used needles. A significant percentage of students have not yet gained the critical thinking necessary to consider the importance of universal precautions as a means not only of self-protection but also of prevention of hospital infections. CONCLUSIONS: Students consider the basic standard measures for the control of infectious diseases only like self-protection and not to prevent hospital infections.

Assessment of humoral and cell-mediated immunity against Bordetella pertussis in adolescent, adult, and senior subjects in Italy.

Humoral and cell-mediated immunity (CMI) against B. pertussis was assessed in a sample of adolescent, adult and senior subjects distributed in five different geographical areas in Italy. Most (99.1%) subjects had IgG anti-pertussis toxin (PT) antibodies exceeding the minimum detection level [> or = 2 ELISA units (EU)/ml]. There were no significant differences between the genders; 6.2% samples recorded titres > or = 100 EU/ml. CMI was positive [stimulation index (SI) > or = 5] against PT in 39.0% of all samples. This study suggests that B. pertussis continues to circulate in age groups that have been previously considered to be uninvolved in the circulation of this pathogen and that adolescent and adult pertussis boosters may be of value in these populations. Nevertheless, over the last 10 years, large increases in vaccination coverage rates have contributed to reduce the spread of the aetiological agent, especially in the immunized population.

Cervical cancer screening in the Ferrara Local Health Authority catchment area.

Since 1996, the Emilia-Romagna Region has been promoting screening programmes for cervical cancer, selecting resident women aged 25-64 as a target population. This analysis concerns a second round of screening performed in the city of Ferrara and its province. A total of 103,971 women were invited to be screened, but only 55.51% of them arrived on the day of the scheduled screening. We therefore decided to investigate the reasons for this lack of participation using preliminary findings from the local screening program registry. These indicated that non-attendance was related to variables such as area of residence and age, and significant differences were observed between localities, with a consistently greater participation in industrial neighbourhoods and their surroundings than in rural areas. In order to elucidate these observations further, a cross-sectional survey, placing special emphasis on setting, area of residence, age and level of education, was performed by structured telephone questionnaire, in order to identify the reasons behind non-attendance. Approximately 94% of the contacted women agreed to be interviewed, thereby demonstrating that a telephone interview is a valid means of collecting data in such cases. It should be noted that, among the women unwilling to respond to the questionnaire, a marked increase in percentage was observed for those resident in rural areas, of whom approximately 50% fell into the under-40 age group. The results of the survey indicated, as demonstrated by several previous studies, that age and the area of residence are both determining factors in the decision or not to participate in a screening programme. It was also observed that women who had completed the lower and upper secondary school education were shown to pay greater attention to health matters than those who had not.

[Persistence of circulation of Corynebacterium diphtheriae non-toxigenic strains and low prevalence of carriers in a sample of children vaccinated against diphtheria]. / Persistente circolazione di ceppi non tossigeni di Corynebacterium diphtheriae e bassa prevalenza di portatori in un campione di bambini vaccinati contro la difterite.

This study was carried out with the aim to investigate the presence of carriers of diphtheria bacillus in a sample of 1970 healthy children, 6-14 years aged, residing in eight Italian towns. Three non-toxigenic strains of Corynebacterium diphtheriae biotype mitis were isolated from as many healthy children. Molecular characterization by ribotyping showed close genetic relation of two of the wild strains with the C7(b) reference strain whereas one of the wild strains showed close genetic relation with two collection strains isolated in the same geographic area (Emilia-Romagna) from diphtheria patients in the seventy years. This supports the hypothesis of the persistence of some non toxigenic C. diphtheriae strains derived from ancient endemic strains under the selective pressure of mass immunization against diphtheria. The persistence of carriers of diphtheria bacilli, although non toxigenic, suggests that high levels of immunity must be maintained, not only in children, but also in adults by booster vaccination.

Ultrastructural abnormalities of muscle spindles in the rat masseter muscle with malocclusion-induced damage.

Human temporomandibular disorders due to disturbed occlusal mechanics are characterized by sensory, motor and autonomic symptoms, possibly related to muscle overwork and fatigue. Our previous study in rats with experimentally-induced malocclusion due to unilateral molar cusp amputation showed that the ipsilateral masseter muscles undergo morphological and biochemical changes consistent with muscle hypercontraction and ischemia. In the present study, the masseter muscle spindles of the same malocclusion-bearing rats were examined by electron microscopy. Sham-operated rats were used as controls. In the treated rats, clear-cut alterations of the muscle spindles were observed 26 days after surgery, when the extrafusal muscle showed the more severe damage. The fusal alterations affected predominantly capsular cells, intrafusal muscle fibers and sensory nerve endings. These results suggest that in the malocclusion-bearing rats, an abnormal reflex regulation of the motor activity of the masticatory muscles may take place. They also allow us to hypothesize that muscle spindle alterations might be involved in the pathogenesis of human temporomandibular disorders.

Factors influencing vaccine uptake in Italy.

In Italy, vaccination of children is regulated by a dual system, that is a certain number of compulsory immunisations, and a number of other facultative vaccinations. This has resulted in a different coverage against infections under the two regimens. While the percentage of immunised children against polio, diphtheria, tetanus and hepatitis B is around 95%, until recently the average coverage with facultative vaccinations was no >50%. Coverage against pertussis has dramatically increased in recent times thanks to the advent of acellular and combined vaccines. Regional programmes that aim to increase coverage against measles, mumps and rubella are presently underway. In order to verify the attitude of mothers towards vaccination, a questionnaire-based study was proposed to women taking their children to vaccination services for mandatory immunisation. The preliminary results on 300 questionnaires show a generally favourable attitude towards vaccines of 80% of mothers. Only 7% of them would not immunise at all their children if vaccinations were not mandatory. Measles and mumps vaccines are considered important by 92% of mothers. However, a high number of both parents and paediatricians still give disproportionate importance to mild intercurrent diseases as a reason to differ immunisation. In the middle-long term, it is likely that Italy will shift to a system of recommended immunisations without compulsion. Before this happens, wide and in-depth campaigns on the benefits of vaccination need to be planned and implemented by central and local health authorities, in order to avoid the risk of a dramatic drop of coverage.

Travoprost compared with latanoprost and timolol in patients with open-angle glaucoma or ocular hypertension.

PURPOSE: This study evaluated the safety and intraocular pressure-lowering efficacy of two concentrations of travoprost (0.0015% and 0.004%) compared with latanoprost 0.005% and timolol 0.5% in patients with open-angle glaucoma or ocular hypertension. METHODS: Eight hundred one patients with open-angle glaucoma or ocular hypertension were randomly assigned to travoprost 0.0015%, travoprost 0.004%, latanoprost 0.005%, or timolol 0.5%. The efficacy and safety of travoprost (0.0015% and 0.004%) daily was compared with latanoprost daily and timolol twice daily for a period of 12 months. RESULTS: Travoprost was equal or superior to latanoprost and superior to timolol with mean intraocular pressure over visits and time of day ranging from 17.9 to 19.1 mm Hg (travoprost 0.0015%), 17.7 to 19.1 mm Hg (travoprost 0.004%), 18.5 to 19.2 mm Hg (latanoprost), and 19.4 to 20.3 mm Hg (timolol). For all visits pooled, the mean intraocular pressure at 4 PM for travoprost was 0.7 mm Hg (0.0015%, P =.0502) and 0.8 mm Hg (0.004%, P =.0191) lower than for latanoprost. Travoprost 0.004% was more effective than latanoprost and timolol in reducing intraocular pressure in black patients by up to 2.4 mm Hg (versus latanoprost) and 4.6 mm Hg (versus timolol). Based on a criterion of 30% or greater intraocular pressure reduction from diurnal baseline or intraocular pressure 17 mm Hg or less, travoprost 0.0015% and 0.004% had an overall response to treatment of 49.3% and 54.7%, respectively, compared with 49.6% for latanoprost and 39.0% for timolol. Iris pigmentation change was observed in 10 of 201 of patients (5.0%) receiving travoprost 0.0015%, six of 196 of patients (3.1%) receiving travoprost 0.004%, 10 of 194 of patients (5.2%) receiving latanoprost, and none of the patients receiving timolol (0 of 196). The average ocular hyperemia score was less than 1 on a scale of 0 to 3, indicating that on average patients experienced between none/trace and mild for all treatment groups. There were no serious, unexpected, related adverse events reported for any therapy. CONCLUSIONS: Travoprost (0.0015% and 0.004%), a highly selective, potent prostaglandin F (FP) receptor agonist, is equal or superior to latanoprost and superior to timolol in lowering intraocular pressure in patients with open-angle glaucoma or ocular hypertension. In addition, travoprost 0.004% is significantly better than either latanoprost or timolol in lowering intraocular pressure in black patients. Travoprost is safe and generally well tolerated in the studied patient population.

Dantrolene counteracts the masseter muscle damage induced by artificial occlusal wear: studies in a rat model.

In previous studies, we showed that the introduction of occlusal alterations to rats results in masseter muscle abnormalities. Here, we investigate whether administration of the muscle relaxant dantrolene to rats with occlusal alteration could counteract the occurrence of such abnormalities. Rats underwent unilateral amputation of molar cusps to cause malocclusion. Some rats received dantrolene (10 mg/kg/day subcutaneously). The masseter muscles ipsilateral to the amputated molars were excised 26 days later. Sham-operated rats were used as controls. The tissue samples were studied by light and electron microscopy and morphometry. Moreover, tissue Ca2+ content, an index of muscle injury, was determined. In the absence of dantrolene, occlusal alteration leads to microvessel constriction, morphologic damage of masseter muscle fibers and blood capillaries, and elevation of tissue Ca2+ content. These changes were nearly abrogated by dantrolene, thus supporting it as a possible new therapeutic tool for the treatment of malocclusion-induced muscle diseases.

Evidence of increased carriage of Corynebacterium spp. in healthy individuals with low antibody titres against diphtheria toxoid.

This study evaluated whether a correlation exists between carriage of corynebacteria and the lack of immunity to diphtheria toxoid. Samples of both nasal and pharyngeal secretions were taken from 500 apparently healthy subjects of both sexes and of all ages and inoculated onto Tinsdale's medium. A serum sample was also taken for ELISA test to determine the titre of diphtheria toxin antibodies. None of the subjects carried Corynebacterium diphtheriae. Ninety-three strains of Corynebacterium spp. were isolated from 93 subjects and 86 of these were classified to species or group level by biochemical tests. C. xerosis was the most common (25.8%) followed by C. pseudodiphthericum (16.1%), C. jeikeium and C. striatum (both 10.8%), and C. urealyticum (9.7%). Three other species accounted for approximately 20% of strains and seven were unclassified as biochemically atypical corynebacteria. Non-protective antibodies to diphtheria toxin were found in 80 of the 93 subjects and a strong statistical association was demonstrated between carriage of corynebacteria and non-protective levels of anti-toxin antibodies. The remaining 13 subjects had protective levels of antitoxin antibodies. In contrast, only 45 of the 407 non-colonized subjects had non-protective antitoxin titres. The prevalence of carriage increased with age among males as did the percentage of non-protected subjects. The prevalence of female carriers of corynebacteria was significantly lower. Serum samples from 12 subjects with different antibody titres to diphtheria toxoid reacted to varying degrees with whole-cell lysates of a number of species of corynebacteria. The results suggest that a causal relationship may exist between nasopharyngeal carriage of corynebacteria and a low anti-diphtheria toxin immune response.

Morphologic and biochemical changes of the masseter muscles induced by occlusal wear: studies in a rat model.

Occlusal alterations may result in changes in the functional performance of masticatory muscles. In this study, we set up an experimental model in rats to examine whether masticatory muscle abnormalities occur after a malocclusion is induced. Rats underwent unilateral amputation of the molar cusps to simulate an occlusal wear situation. The masseter muscles ipsilateral and contralateral to the amputated molars were excised at different experimental times. Sham-operated rats were used as controls. The tissue samples were studied by light and electron microscopy and morphometry. Tissue calcium content, a biochemical index of muscle injury, was also determined. The results show that occlusal dysfunction leads to microvessel constriction and clear-cut morphologic damage of muscular fibers and blood capillary endothelium, as well as to elevation of tissue calcium content, in the ipsilateral masseter muscle. These changes are likely related to muscle fatigue and ischemia. The early signs of injury do not involve the entire muscle but are mostly restricted to tissue areas rich in type I (slow) muscle fibers, which are characterized by a predominantly aerobic metabolism. The muscle damage becomes more extended and severe with time. On the other hand, the contralateral muscles show only slight alterations which are reversible with time, possibly due to an adaptive response.