Revealing microplastic dynamics: the impact of precipitation and depth in urban river ecosystems

Research on microplastics in Latin America is limited compared to a global perspective. Brazil plays a significant role in this context, as it possesses 12% of the world's freshwater reserves, constituting 53% of South America's water resources. There has been growing concern regarding the plastic pollution of the country's freshwater systems in recent years. Therefore, this study investigated the impact of plastic pollution on the Guaíba River, a significant watercourse in the southern region of Brazil that is subjected to high anthropogenic pressure. Additionally, we examined correlations between the presence of microplastics and key factors influencing their distribution in the river. Thus, freshwater was collected in seven sampling campaigns from 2019 to 2020, totaling 66 samples. The microplastics were quantified and characterized according to their color, shape, and polymeric composition. The concentration of microplastics varied between 2.9 and 53.8 items m-3, and the distribution and transport were positively influenced by the population density, precipitations, and depth of each sampling point. White-transparent color category (51%) and fragment shape (89%) were predominant among the found particles. Polyethylene (PE) and polypropylene (PP) represented 37% and 57% of the analyzed particles. The non-metric multidimensional scaling (nMDS) analysis indicated that similar contamination sources, such as domestic sewage, could influence three out of ten sampled points. Several microplastics presented the formation of cracks, with sizes smaller than 10 μm on their surface, which might indicate an erosion process, resulting in the formation of nanoplastics. The color fading observed in microplastics suggests that the particles were subjected to environmental stressors, leading to the leaching or degradation of the dye on the plastic. The results confirmed the ubiquity of microplastics in Guaíba River, highlighting the importance of improving the regulations on plastic waste disposal in the country to prevent the contamination of freshwater bodies.

How natural and anthropogenic factors should drive microplastic behavior and fate: The scenario of Brazilian urban freshwater

Brazil maintains its position at the top of the global ranking of plastic producers, yet recycling efforts have been incipient. Recent data reveals an annual production of approximately 14 million tons of plastic waste, not accounting for the surge in the usage of plastic masks and related materials due to the COVID-19 pandemic. However, what remains largely unreported is that over half of post-consumer plastic packaging in Brazil is managed without any monitoring, and it remains unclear how this will contribute to the occurrence of plastic waste and microplastics in Brazilian freshwaters. This scenario requires the consideration of several other crucial factors. Studies have been carried out mainly in marine and estuarine waters, while data on freshwaters are lacking. Brazil has continental dimensions and the highest water availability on the planet, yet the demand for water is greatest in regions with medium to low supply. Many densely populated Brazilian urban areas face chronic flood problems, possess inadequate levels of wastewater treatment, and display inadequate solid waste management practices. Consequently, urban freshwater with tropical characteristics in Brazil presents an intriguing scenario and is complementary to the most commonly studied marine environments. In this study, we explore the nuances of pollution in Brazilian urban freshwater and discuss how various parameters, such as organic matter, suspended solids, temperature, and pH, among others, influence the behavior of microplastics and their interactions with organic and inorganic contaminants. Furthermore, we address how microplastic conditions, such as biofouling, the type of plastic, or degradation level, may impact their behavior. By analyzing how these conditions change, we propose priority themes for investigating the occurrence of microplastics in Brazilian urban freshwater systems under different degrees of human impact. Ultimately, this study aims to establish a network dedicated to standardized monitoring of microplastic pollution in Brazilian urban freshwaters.

Microplastics in Latin America Ecosystems: A Critical Review of the Current Stage and Research Needs

The ubiquity of microplastics ecosystems has gained global attention. In this context, Latin America, which is responsible for 8% of the world’s consumption of plastic material and has a small recycling rate (4.5%), does not have enough data on microplastics contamination in its environmental matrices. This systematic review analyzed 196 studies from 16 territorials in Latin America and provided information about the current state of knowledge regarding the abundance, distribution, and associated impact of microplastics in different matrices. This review also describes the analytical procedures of sampling, extraction, identification, and characterization methodologies adopted by the literature review. The analysis shows that most of the studies that investigate microplastics abundance were carried out in the marine environment (59%), and there is an insufficient investigation on microplastics abundance in freshwater bodies (16%). Among all the studies, the highest microplastics concentration was observed in regions with high population density and/or in locations without proper sanitation and solid waste management. Additionally, the difference among microplastics abundance in the studies might be associated with the different analytical procedures employed to investigate microplastics. Lastly, knowledge gaps are identified, and recommendations are proposed to guide future studies on microplastics contamination.

Sorption of endocrine disrupting compounds onto polyamide microplastics under different environmental conditions: Behaviour and mechanism

Microplastics of polyamide are commonly found in aquatic environments and might act as vectors of different contaminants such as endocrine disrupting compounds (EDC). Therefore, sorption of 17α-ethynylestradiol (EE2), 17β-estradiol (E2), and estriol (E3) on polyamide microplastics was studied under different simulated environments. The results suggest that the sorption process was affected by the presence of dissolved organic matter (DOM) and salinity, where both positive and negative effects were observed. Kinetics revealed that the process occurs through multiple steps wherever the sorption rate depicting the transportation of EDC molecules from the liquid phase to the solid boundary of the sorbent, is higher than the intraparticle and pore diffusion process. In addition, the sorption rate of E2 decreased with the increase of water matrix complexity from ultrapure water (UPW) > artificial seawater (ASW) > fulvic acid water (FAW) > artificial seawater with fulvic acid (AS/FAW), while the sorption rate of EE2 decreased from UPW > ASW > FAW and increased in the matrix combining salinity and organic matter (AS/FAW). On the contrary, the E3 sorption rate increased with matrix complexity, from UPW < ASW < FAW and decreased with the influence of salinity and organic matter combination (AS/FAW). The sorption capacity of the EDC reached maximum values of 82% for E2, 90% for EE2 and 56% for E3. Isotherms demonstrated the occurrence of multilayer sorption. A positive relationship has been found between the hydrophobicity of polyamide microplastics and the Log K_ow of EDC, showing an important role of hydrophobic interactions in the sorption process under all the studied conditions. Moreover, hydrogen bonding and binding of contaminants and DOM to microplastics through bridges were also suggested. The results show that salinity and DOM can greatly influence the sorption and transportation of EDC in the aquatic environment and pose a risk to aquatic ecosystems.

First evidence of microplastic contamination in the freshwater of Lake Guaíba, Porto Alegre, Brazil

The ubiquitous presence of microplastics in the aquatic environment has raised concern about their potential impacts on and risks to the biota. While the presence of microplastics in a marine environment has been well studied, the impact of microplastic contamination in freshwater bodies is understudied. In the present study, baseline data about contamination with microplastics in Lake Guaíba in southern Brazil are presented. The abundance, distribution, and composition of microplastics in the surface of this freshwater body were investigated, and these parameters were correlated with population density, land occupation, wind, and geohydrologic processes. The samples were collected with a manta net (60 μm mesh size). Microplastics were found in all the samples, with an average of 11.9 ± 0.6 to 61.2 ± 6.1 items m^-3, which indicates the widespread contamination of the lake with plastic particles. The most frequent microplastic morphology was the fragment type in the size range of 100 to 250 μm, and the predominant colours were white/transparent and red. Measurement uncertainty of the visual microplastic counts showed that black colour microplastics is more susceptible to be mistaken, which might lead to an underestimation and/or overestimation of the total number of microplastics. Polypropylene and polyethylene together comprised most of the polymer types (98%). Micro-Fourier transform infrared (micro-FTIR) spectroscopy analyses showed that 58% of the analysed polymers were highly oxidised, indicating long residence of this particles in the water. In addition, our data show that the distribution of microplastics is strongly influenced by the geohydrological characteristics of the lake. Therefore, this research may provide information for further investigations of microplastic distribution in Lake Guaíba and can serve as a base to improve the regulations regarding waste management to effectively reduce microplastic pollution in freshwater systems. Additionally, the measurement uncertainty showed that black microplastics are more susceptible to variations in their measurements.

Photodegradation of Emerging Contaminant 2-(tiocyanomethylthio) Benzothiazole (TCMTB) in Aqueous Solution: Kinetics and Transformation Products

Direct photolysis of the emerging contaminant 2-(thiocyanomethylthio) benzothiazole (TMCTB) was performed in aqueous solution at different concentrations with high-pressure mercury lamp (5.0, 8.0, 13.0, 16.0, 20.0, 23.0, 27.0, 35.0, 40.0, 45.0, and 50.0 mg L^- 1) and with natural sunlight radiation (6.0, 30.0, and 60.0 mg L^- 1). TCMTB underwent rapid degradation by direct photolysis with a high-pressure mercury lamp in aqueous solutions, with 99% removal after 30 min at all concentrations studied. For sunlight photolysis, TCMTB degradation was observed with 96%, 81%, and 64% removal for initial concentrations of 6.0, 30.0, and 60.0 mg L^- 1, respectively, after 7 h of exposure to sunlight. The degradation of TCMTB in lab-scale wastewater had kinetic constant and t_1/2 in the same order when compared to the photodegradation of TCMTB in aqueous solutions. In addition, the results showed that photolysis with a high-pressure mercury lamp and sunlight were governed by the same kinetic order, however the kinetic parameters showed that degradation with sunlight was 40 times slower than photolysis with the mercury lamp. Twelve transformation products (TP) were identified, and eight of the TP have not been described in the literature. Furthermore, prediction of toxicity with ECOSAR software was carried out for fish, daphnids, and green algae species. It showed that photolytic treatment is efficient for reducing the toxicity of the compound, since the degradation formed compounds with lower toxicity than the primary compound. In conclusion, this study suggests that photolysis is an efficient way to remove the studied contaminant, and it highlights the potential of this technique for the degradation of emerging contaminants in industrial wastewater treatment plants.

The use of only enamel matrix derivative allows outstanding regeneration results in periodontal intrabony defect treatment: a retrospective study

Periodontal tissue regeneration depends on several biological, homeostatic and regulative variables that directly induce the clinical features. The aim of this study is to compare the clinical results obtained using the enamel matrix derivative peptide (EMP) compared to the less manageable association of EMP and bovine bone xenographic (BPBM) in the treatment of deep intraosseous defects. Ten healthy patients, suffering from moderate or severe chronic periodontitis, having at least two deep and narrow intrabony defects in the same dental arch and needing surgical treatment, were selected. The same patient was treated with the two different materials: EMP -TG1 in one defect and the association-TG2 in the other. Immediately before surgery (T0) and 12-month after (T2) the probing depth (PD) and gingival recession (GR) were registered at the experimental sites. No statistically significant differences were shown between TG1 and TG2 at T0 nor at T1 in term of PD and GR, while a statistically significant PD decrease was found both in TG1 and TG2 between T0 and T1 (p less than 0.05). GR increase resulted statistically significant in TG1 (p less than 0.05) but not in TG2 between T0 and T1 (p≥0.05). In this split-mouth retrospective study, both the treatments achieve favourable clinical results but the TG1 shows a significant increase in GR probably because EMP is not able to support the gingiva covering the intrabony defect. Therefore, the choice of the type of periodontal defect to be treated with EMP will be a therapeutic key-point.

Effects of soft-drinks and remineralising treatment on teeth assessed by morphological and quantitative X-ray investigations

AIM

To morphologically and chemical-physically analyse both the surface and the subsurface of enamel undergoing soft- drink demineralisation and remineralisation treatment.

MATERIALS AND METHODS

Fifteen human premolars were split and immersed in saline or three popular soft drinks, as demineralising agent, 15 minutes per day, for seven days at room temperature. Half of drink-processed teeth was then treated with casein phosphopeptide-amorphous calcium phosphate, as remineralising agent, for an additional seven days. The surface morphology was evaluated by stereomicroscope and scanning electron microscope (SEM). Teeth were then re-embedded and sectioned, and analysed under SEM and X-ray microprobe.

RESULTS

Drink-processed teeth showed root pigmentation, opacification and deterioration of the superficial enamel. The enamel surface resulted greatly furrowed after drink processing, and apparently restored after remineralising treatment. However, in tooth sections, SEM showed always a subsurface demineralisation of dentine and enamel, in particular at the cementoenamel junction, also after reminalising treatment. The remineralising agent produced a partial remineralisation of the subsurface enamel, sometimes statistically significant, but not in hydroxyapatite stoichiometry.

CONCLUSION

Soft-drink erosion impaired not only the surface but also the subsurface enamel. The applied remineralising treatment, yielding some effects on surface and subsurface enamel reversing basically the decalcification process.

Augmentation of keratinized gingiva through bilaminar connective tissue grafts: a comparison between two techniques

AIM

A mucogingival deficiency is considered a potential risk factor for periodontal disease. In particular, mucogingival deficiency can lead to gingival recession, which is a pathological entity per se, due to the increased risk for dental hypersensitivity and root caries. The aim of this study was to evaluate and compare 2 bilaminar grafting techniques normally employed to achieve root coverage.

METHODS

Thirty-five patients were divided into 2 groups. Group 1 included 19 patients with 49 gingival recessions treated by Nelson technique (as modified by Harris), while group 2 included 15 patients with 40 recessions treated by Langer technique. Clinical evaluation was performed at preoperative level (T0), after 1 month (T1) and after 1 year (T2). Statistical analysis was performed by means of Friedmann and Wilcoxon test and U-Mann-Whitney test.

RESULTS

The statistical analysis did not reveal any significant difference between groups, both in terms of percentage of root coverage and of width of keratinizaed gingiva gain. A significant difference was only observed within each group, for the amount of keratinized gingiva at T1 vs T0 and at T2 vs T1.

CONCLUSIONS

This study did not show any statistical difference between the Nelson and the Langer technique as to root coverage and gain in keratinized gingiva.

Release of elements from retrieved maxillofacial plates and screws

Vitallium appliances and surrounding tissues were investigated to evaluate the release and accumulation of elements. Four microplates, sixteen screws and surrounding tissues were removed from three patients presenting inflammation 4 to 6 years after surgery and were submitted to SEM and X-ray microprobe analysis. Histology was performed on paraffin or PMMA sections of tissues.A continuous release of elements from metallic appliances into soft tissues was observed. Cobalt, chromium, and nickel were detected in soft and boney tissues in close proximity to the appliance. Aluminium, as a component of screw coatings, accumulated in soft tissues, and a remarkable amount of aluminium was detected in the dense lamella of lamellar bone. The results suggest that coatings containing aluminium should be avoided and the time these appliances are allowed to remain in patients should be shortened. Further studies on element release and the fate of aluminium in bone are warranted.

[Metallic elements in tissues surrounding internal rigid fixation (IRF) devices]

BACKGROUND

Plates and other devices made by several alloys have been introduced to reach the stability of bone fractured fragments. Elements constituting alloys could be detected especially in organs, yet also in local tissues. Aim of the present study is the analysis of tissues surrounding IRF devices analyzing the morphology of released particles and studying the behavior of adjacent tissues to check metallic elements diffusion.

METHODS

Biopsies were retrieved from 18 patients, aged 20 to 76 years. The patients received IRF by plates, screws and grids from 4 months to 9 years. They were divided into five groups according to the local phlogistic degree. Ordinary light microscopy, scanning electron microscopy and X-ray microprobe analysis (EDS system) was used to perform morphological investigations and identification of metal particles and elements.

RESULTS

Metal particles or elements arising from plates, screws or grid may undergo tissular diffusion and cellular uptake. Not only Chromium, Iron or Aluminium but also Titanium may be easily released from devices and engulfed in tissues. In particular Titanium diffusion is evident in fibrous tissue surrounding IRF devices. Aluminium appears to be particularly accumulated in a persistent way in fibrous tissues and shows a characteristic embedding pattern in lamellar bone.

CONCLUSIONS

The degree of local phlogosis appears to be strictly correlated to metallosis. Chromium, Iron, Aluminium and also Titanium, even if at different degree, give rise to phlogistic effects. Metallosis and phlogosis can produce a cascade process in which they are both the cause and the effect at the same time. The abundant release of Titanium, which does not normally produce clinical phlogosis as i.e. Aluminium, should be worthy of further investigations on its cellular effects.

Associated orthodontic, surgical and hematological management of Cooley s anemia. Report of a case

Cooley s anaemia or b-thalassaemia or mediterranean anaemia is a blood disease characterised by malformation of the skull and long bones, which confers a typical appearance on the patient. The complete development of facial abnormalities can be prevented by an intensive blood transfusion programme or by bone-marrow-transplantation. At the present time these therapeutic strategies would be able to help these patients grow and develop, live a prolonged life and avoid bad surgical RESULTS. The aim of this study was to evaluate the feasibility of orthodontic and maxillofacial surgical corrective treatment associated with an appropriate transfusion therapy in a b-thalassemic patient. The patient enrolled in the study was affected by major b-thalassemia and diagnosis was performed as an infant. She was referred to our centre at puberty for dento-maxillofacial disorders. Clinical, haematological and radiographic evaluation permitted a complete diagnosis. She received a combined haematological, orthodontic and maxillofacial surgical treatment. Controls for evaluating the statement of results obtained were performed at different times after the end of the therapy and have shown that the therapeutic objectives had been achieved and maintained. At the present time, complete diagnostic and therapeutic haematological strategies cannot be carried out on a large scale, especially in countries where health resources are limited. This objective reason, associated with possible low patient compliance, explains why we still encounter severe facial deformities resulting from erythroid hyperplasia. Our results suggest that this facial disfigurement requires surgical and orthodontic correction by consolidated surgical-orthodontic techniques performed according to the appropriate anaemia therapy. Although this is a preliminary study, initial encouraging results show no relapse three years after the end of the therapy.

[Clinical evaluation, radiologic and histologic analysis in mandibular alveolar distraction procedures. Preliminary study]

BACKGROUND

Alveolar distraction osteogenesis is a process to form new alveolar bone to correct alveolar deformities in ridge height and width. Aim of this work is to study the bone processes to optimize the implantoprosthetic rehabilitation.

METHODS

Alveolar distraction osteogenesis was applied in 7 patients with ridge deformities to obtain the desired ridge augmentation. Clinical and radiological evaluations were performed during the following 12 weeks, before implant insertion. Biopsies at 40, 60 and 88 days were studied after general, specific and histochemical staining of slides; microradiographs were analyzed to evaluate the trabecular bone volume.

RESULTS

Forty days after the end of distraction, soft callus shows the start of ossification. Sixty days after the end of distraction, soft callus was widely converted into a network of trabecular woven bone; osteogenic activities were low; trabecular bone volume was about 50%. Eighty-eight days after the end of distraction bone amount appeared reduced, with a more ordered structure, further reduction of bone formation activity, whereas osteoclast erosion was active.

CONCLUSIONS

Results show an almost steady-state bone deposition processes 60 days after the end of distraction and a regress with longer time. The results suggest the possibility of an early implant insertion to avoid bone loss due to mechanical unloading.

[The treatment of the cardiac patient in dentistry and oromaxillofacial surgery. I. The practical management of patients with arrhythmias]

Cardiac patients consist of a high incidence rate in odontostomatology, both clinical and surgical. Moreover this serious complication disease conditions odontostomatological and, particularly, surgical works. In this article the authors present the results of several years of research carried out to obtain a correct clinical and therapeutic approach for clinical and surgical dentistry. After an introduction on the clinical features of heart diseases the most important clinical cases of heart dysrhythmia are discussed: like, i.e. hypokinetic arrhythmia, hyperkinetic arrhythmia and the management of patients with pacemakers. The principal diacritic features of dysrhythmic diseases are illustrated. Anxiety is a sort of disease not directly related with dysrhythmia. Moreover a lot of clinical studies find in heart arrhythmia the principal problem caused by anxiety on heart physiology. Consequently the authors describe anxiety in the same part of pathologies commonly known as heart dysrhythmia. In the last phase the authors illustrate the most opportune therapeutic steps corresponding to the principal pathologies described above. These matters were dealt with from an odontostomatological point of view. The results obtained suggest the necessity of keeping to the management that was described. Actually a low percentage of accidents occurred only when the above-mentioned clinical processes were completely performed.

[The treatment of the cardiac patient in dentistry and oromaxillofacial surgery. II. The practical management of patients with hemodynamic pathologies]

When odontostomatological or surgical treatment is performed we suggest, in a first phase, to distinguish cardiac patients from the others. In a second phase a careful nosological diagnosis will be performed. Consequently, patients' medical history plays a fundamental role in both diagnostic phases. In this article the authors present the results of several years of research carried out to obtain a correct clinical and therapeutic approach for clinical and surgical Odontostomatology. After an introduction on the clinical features of heart hemodynamic pathologies the most important clinical cases are discussed: like, for example, acardiohemia, valvulopathies and heart decompensation. The principal diacritic features of hemodynamic diseases are illustrated. Essential hypertension (borderline and resident) is a sort of disease not directly related to hemodynamics pathology. Moreover a lot of clinical studies find in heart hemodynamic pathologies the principal problem caused by hypertension on heart physiology. Consequently the authors describe essential hypertension in the same part of pathologies commonly known as heart hemodynamic pathologies. In the last phase the authors illustrate the most opportune therapeutic steps corresponding to the principal pathologies above-described. These matters were dealt with from an odontostomatological point of view. The results obtained suggest the necessity of keeping to the management that was described. Actually a low percentage of accidents occurred only when the above-mentioned clinical processes were completely performed.

[Treatment of the patient with a coagulation defect in oral and maxillofacial surgery. III. The management of patients in a hypocoagulative state because of a hemophilic-type primary pathology]

Hemophilia plays a particularly important role among the diseases caused by abnormal coagulation. Defective blood-clotting factor diseases have a particular importance between coagulopathies: hemophilia, among these hematic disorders, plays a principal role. In this paper the authors present the results of scientific research on hemophilic disease carried out to obtain a correct clinical and therapeutic approach for clinical and surgical Odontostomatology. The authors, after having presented in short the physiopathologic function of coagulation factors, illustrate the clinical and therapeutic aspects of Hemophilia A and Hemophilia B. The correct Odontostomatological and Maxillo-Facial Surgical approach is presented as the result of the authors' research. Also von Willebrand's disease is illustrated even if it is not exactly a hemophilic disease. This is because all hemophilias must produce a gynephoric inheritance pattern. Nevertheless clinical, therapeutic and molecular biology appearance suggests the illustration of von Willebrand's disease together with hemophilias. Von Willebrand's disease can be divided into three nosologic groups and to each one corresponds a particular clinical and therapeutic management. Such cases are illustrated and examined from an Odontostomatologic point of view. The results obtained suggest the necessity of keeping to the management that was described. Actually a low percentage of accidents occurred only when the above-mentioned clinical processes were completely performed.

[Management of facial pain resulting from cancer in oral and maxillofacial surgery]

Pain, which is among the most prevalent symptoms experienced by cancer patients, must absolutely be treated. The most important biologic effects of this sort of pain plays on patients' psychosociality. This is in reference to the quality of pain, the amount of pain and to the character of the patients. Actually, pain only in appearance is presented as a symptom; it is usually a disease. Patient assessment, the use of anticancer therapies and systematically administered non-opioid and opioid analgesics are pivotal. Practical aspects of cancer pain treatment include both drug selection, method of analgesic administration: selection of the appropriate route, dose titration and an understanding of the management of side effects. Pain therapy includes another series of possibilities like the use of adjuvant analgesics, psychological therapies, physiatric techniques and invasive interventions such as the use of intraspinal drugs, neural blockade and neuroablative techniques. This kind of therapy must be employed at all times, whether the case may be resolved surgically or not. So we think that pain can be effectively treated. This study was carried out to obtain the correct therapeutic approach for facial cancer pain syndrome. The research was performed on seven women and thirteen men with a mean age of 58 years. All the patients' clinical appearances were standardized with care. Study participants included odontostomatologists and anesthesiologists with experience of controlling cancer pain. The sensation of pain was quantified by means of the Visual Analogue Scale (VAS) while their psychosocial ability was assessed with the Karnofsky Performance Scale (KPS). In this way the authors hoped to obtain a good quality of standardization. The study was performed for a period of two months. The conclusions are that Trans Epidermis Nervous Stimulation (TENS) offers positive results for variable periods and only in 60% of patients with a low level of pain. The use of antiphlogistic non-steroid drugs and of opioid drugs, with a particular management requested from the personal clinical status of each patient, result as being the most effective therapeutic resource. Such therapies must be employed, whether the case may be resolved surgically or not. Nevertheless it is necessary to realize that drugs or other therapies for cancer pain are independent and propaedeutic to each surgical approach. Finally, the use of opioids is addressed in the management of patients with pain that is refractory to other interventions. This approach can provide adequate relief to the vast majority of patients. We find the morphinomania risk in cancer pain patients is not scientifically wellfounded.

[Management of patients with coagulation disorder in oral and maxillofacial surgery. I. Management of patients with hypocoagulation caused by primary thrombocytopathy]

Any oral and maxillo-facial surgical treatment, however urgent it may be, must not include pathological states in which the patient's life may be particularly at risk as, for example, with Disseminated Intravascular Coagulation (DIC) or throm-botic thrombocytopenic purpura. In this article the authors present the result of studies carried out on the nosology of thrombocytopathy from an odontostomatological point of view. Thrombocytopathy can be divided into two groups: the first including the pathologies with a predominant defective number of thrombocytes (i.e.: thrombocytopenia, thrombocythemia, thrombocyto-sis), the second including forms with predominant qualitative defects (commonly known as thrombocytopathies). The authors, after having presented in short the physiopathologic functions of thrombocytes, illustrate the clinical and therapeutic aspects of the most important thrombocytopathies. Morbus Maculosus Werhofii, Glanzmann's disease, Bernard-Soulier syndrome, thrombocytopathies from defective reaction of release, Thrombocytopathies from defective procoagulant activity of blood plaques, thrombocytopathies in linkage to other genetic anomalies, von Willebrand's pseudodisease and a lot of acquired thrombocytopathies are identified. In the last part the authors illustrate the most opportune clinical steps corresponding to the most important thrombocytopathies. The results obtained suggest the necessity of keeping to the management that was described, Actually a low percentage of accidents occurred only when the above-mentioned clinical processes were completely performed.

[Management of patients with coagulation defect in oral and maxillofacial surgery. I. Management of patients with drug-induced hypocoagulation]

Odontoiatric problems, clinical and surgical, connected with defective coagulation, are very frequent. Such cases can be divided into two groups: in the first we find patients with iatrogenic coagulopathy while in the second we find patients with hypocoagulative diseases. In this article the authors present the result of several years of research carried out to obtain a correct clinical and therapeutic approach for clinical and surgical Odontostomatology. After an introduction on clinical pharmacology and the use of anticoagulants, the principal clinical cases are discussed. Various laboratory tests evaluating patients with pharmacological coagulopathy are examined. The most specific and significant tests are illustrated following up the authors experiences. In the last part the authors illustrate cases corresponding to the two serious and frequent complications that can be found in patients with iatrogenic coagulopathy: hematorrhea and thromboembolism. These matters were dealt with from an Odontostomatologic point of view. The results obtained suggest the necessity of keeping to the management that was described. Actually a low percentage of accidents occurred only when the above-mentioned clinical processes were completely performed.

[Experimentation and clinical analysis of the interrelationships between dental damage and celiac disease]

Celiac disease is characterized by gluten-dependent atrophy of the intestinal tufts. Aetiologically the genetic "habitus" of the subject has particular importance and, as rear as the pathogenesis is concerned, many theories, among which the most accredited one is "immunopathological", exist. According to what this last one provides, the cell-mediated immunity component is to be considered the true mediator of intestinal injury, whereas the antibody-mediated component and, in particular, anti-gliadin antibodies (AGA) and anti-endomysium antibodies (EMA), has a particular and pre-eminent diagnostic role. Just from this point of view the celiac disease appeared, with the progress of the studies, to be more and more fleeting, because of growing symptomatologic diversification. It is then interesting to take into account that the celiac disease seems to be able to maintain itself asymptomatic for the greatest part of life, perhaps, forever, configuring the appearance of silent celiac disease and contributing to specify the outline of the above-mentioned celiac "habitus". Recently, besides, close associations have been found between many different diseases and celiac disease. Even for such reasons we relied upon the indication of the ESPGAN in order to achieve a sure and standardized diagnosis of celiac disease. Early diagnosis of celiac disease is very important because it allows a normal psychophysical development and it avoids the strong incidence of lymphomas and other neoplasms of the gastrointestinal tractus which can characterize the natural story of celiac patients. From a more specifically odontological point of view, interesting manifestations exist in the ambit of celiac disease. This last may in fact appear associated particular signs, such as recurrent aphthae or plainly autoimmune diseases with even oral verification. There, however, a more frequent association between celiac disease and some lesions of the tooth enamel which occur in the period of the two stages of histodifferentiation and mineralisation, and they are, respectively, hypoplasias and opacities. Alteration of the enamel, in such stages, both in deciduous and in permanent sets of teeth may be caused by different "noxae"; hence it will be necessary to know how to distinguish between the dental lesions typical of celiac disease and the others. It is helpful the fact that the dental lesion, observed in the course of celiac disease, remembers conceptually the Chronologic Hypoplasia of the enamel. This pathologic form damages the enamel which is depositing, and evolving contemporaneously to the local or systemic "noxa" which is its remote cause.(ABSTRACT TRUNCATED AT 400 WORDS)

[Precancerous conditions of the oral cavity. Note II--Pathology and clinical course. Critical review of the literature]

The authors examine some specific forms of precancerous states of the oral cavity, selecting them from among the 4 classes defined by the WHO Collaborating Centre for Oral Precancerous Lesions. The immunological system is given particular emphasis. In fact, as studies progress, it appears to be more and more involved not only in the increase in the incidence of such pathologies, but also in the most difficult, if not unknown, genesis of these pathologies. Highly significant examples of this involvement are: Kaposi's Sarcoma, Hairy Cell Leukoplakia, Lichen and Mycoses. Particularly significant aspects for Erythroplasia consist in the following: slow development, frequent and rapid changes in the clinical aspects and its strict connection with Bowen's Disease and Queirat's Erythroplasia. The latter lend further confirmation of its definite precancerous nature and as such, it requires radical surgical treatment. Compared to other forms, the Epidemic variety of Kaposi's sarcoma more frequently affects the oral-salivary glands and structures, the lymph nodes and the laterocervical area. Together with non-Hodgkin tumors, this represents the class of neoplasms most frequently occurring in subjects affected by AIDS. Its "atypical" aggressiveness involves the liver and pancreas and develops over much shorter time periods than the other varieties. In any case, when possible, the treatment required is the excision of the lesions. Neither radiation therapy nor polychemotherapy have yielded encouraging results as yet. In the case of Leukoplakia, it should be kept in mind that today, this pathology is defined "negatively" be exclusion that is the condition must exist that this lesion cannot be clinically or pathologically defined as another lesion. It thus follows that the clinician must maintain an extremely cautious approach in such cases. As concerns prognosis, particular attention should be given to raised, hardened, irregular and fissured forms, which manifest the greatest degenerative capacity. for the classic forms, the treatment adopted is complete exeresis, whereas the use of antiviral drugs is recommended for Hairy Cell Leukoplakia. Lichen Ruber Planus is a papuliferous eruption that is relatively common and affects the skin and mucosa often exclusively involving the oral cavity in the great majority of cases. Besides the clinical picture, the diagnosis of this disease is based on the triad consisting of hyperkeratosis, destruction of the cells of the stratum basale and subepithelial lymphocyte infiltration at distinctly low levels. In uncertain cases, however, the detection of Fluorescent Bodies grouped in large clusters near the hyaline membrane, acquires particular importance for the specification of the diagnosis.

[Precancerous conditions of the oral cavity. Note I. General considerations. Critical review of the literature]

The authors deal with the current topic of precancerous states of the oral cavity, considering various aspects such as etiopathology, diagnosis, the clinical picture and therefore, nosological classifications. The region of the Air Passages and Superior Digestive Tract (APSDT) should be considered as a single system and it is affected by a set of genetic and environmental conditions common to the various anatomical regions of which it consists. The significance of several irritating agents, which are also habitually used (e.g. tobacco), has been demonstrated for some time, whereas, the actual harmful effects of other factors such as immunodepression in particular, are only now being evaluated and detected. The discussion concerning precancerous lesions of the oral cavity, should actually refer to lesions that do not present the histologic, biological and clinical characteristics of malignant neoplasms, but that have the objective possibility of developing them. Some lesions that traditionally belong to this pathological grouping often present dysplastic aspects, if not the actual characteristics of "carcinoma in situ". Therefore, the availability of a set of indexes is of primary importance and it should be capable of providing an orientation for diagnosis and clinical practices in a precise, standardized manner. The authors hold these indexes to be divisible into three groups as follows. The first group is composed of the "parameters of cellular kinetics" and includes the percentage of cells in phase S (LI), phase S time (Ts), cell cycle duration (Tc), and the growth fraction (GF). The second group consists in the "parameters of cellular morphology", including the nuclear content in DNA, the value of the nuclear surface and the ploidy. The third group is more specific for the existence of a pathologic mass. However, given the uncertainties of the borderlines traditionally attributed to precancerous pathology, this group is definitely useful. It is composed of the potential doubling time (Tpot) and the tumor volume doubling time (Td). Moreover, biopsy is held to be an indispensable tool and the procedure should be conducted in the various manners possible according to well-defined conditions. A correct evaluation of these parameters allows for a correct approach to precancerous pathology and the prevention of the clinical risks of "rapid proliferation" even in the diagnostic biopsy phase.

[The growth hormone/somatomedin C system from the first years of life to young adulthood. Physiological aspects and physiopathologic involvement in diabetic syndrome]

The growth hormone (GH)/somatomedin-C (Sm-C) endocrine system plays a fundamental role in human anabolism. Whereas from a physiological point of view GH conforms to the classic hormone behaviour, Sm-C appears to follow a peripheral and local pattern of action with autocrine or paracrine involvement. The hormonal GH system interacts with the functional pattern of insulin and other hormones, and in addition with entire maturation process. On the basis of several reports, the puberal age seems to represent the first real "maturative-tumultuous" event managed by the operative GH/Sm-C system. It is thus possible to hypothesise that alterations to this system, as found in dysmetabolic diseases (e.g. diabetes), may either be seen as a cause or consequence of the disease process. It can therefore also be supposed that such alterations may interact with the development of the entire organism, above all when they occur during the delicate puberal phase.