Accuracy of Artificial Intelligence Models in the Prediction of Periodontitis: A Systematic Review

INTRODUCTION

Periodontitis is the main cause of tooth loss and is related to many systemic diseases. Artificial intelligence (AI) in periodontics has the potential to improve the accuracy of risk assessment and provide personalized treatment planning for patients with periodontitis. This systematic review aims to examine the actual evidence on the accuracy of various AI models in predicting periodontitis.

METHODS

Using a mix of MeSH keywords and free text words pooled by Boolean operators ('AND', 'OR'), a search strategy without a time frame setting was conducted on the following databases: Web of Science, ProQuest, PubMed, Scopus, and IEEE Explore. The QUADAS-2 risk of bias assessment was then performed.

RESULTS

From a total of 961 identified records screened, 8 articles were included for qualitative analysis: 4 studies showed an overall low risk of bias, 2 studies an unclear risk, and the remaining 2 studies a high risk. The most employed algorithms for periodontitis prediction were artificial neural networks, followed by support vector machines, decision trees, logistic regression, and random forest. The models showed good predictive performance for periodontitis according to different evaluation metrics, but the presented methods were heterogeneous.

CONCLUSIONS

AI algorithms may improve in the future the accuracy and reliability of periodontitis prediction. However, to date, most of the studies had a retrospective design and did not consider the most modern deep learning networks. Although the available evidence is limited by a lack of standardized data collection and protocols, the potential benefits of using AI in periodontics are significant and warrant further research and development in this area.

KNOWLEDGE TRANSFER STATEMENT

The use of AI in periodontics can lead to more accurate diagnosis and treatment planning, as well as improved patient education and engagement. Despite the current challenges and limitations of the available evidence, particularly the lack of standardized data collection and analysis protocols, the potential benefits of using AI in periodontics are significant and warrant further research and development in this area.

Perioral muscle activity changes after Lip Bumper treatment

AIM

This prospective non-randomised case-control study analysed lip muscle activity after Lip Bumper (LB) treatment thought surface electromyography.

METHODS

The study group was composed of 40 young patients with a mean age of 10 years and 1 month, treated with LB in the lower arch, while 40 children who did not undergo any treatment, matched for sex and age with the previous sample, constituted the control group. Measurements were performed at the beginning and after 1 year for both groups. Electromyographic recordings were obtained in rest position and during the swallowing of 50 ml of water.

RESULTS

In the study group, after 1 year of LB treatment, a statistically significant decrease in values was found; specifically, in upper lip muscle activities at rest position with the appliance in situ (p <0.002) and both with (p <0.001) and without (p <0.001) the appliance for the lower lip.

CONCLUSION

One year of LB treatment significantly reduced lip muscle activities at both rest position and during swallowing compared with the untreated sample. These results indicated a potential short-term of upper and lower lip muscle adaptation to the new balance induced by LB treatment.

The Evolution of the Cephalometric Superimposition Techniques from the Beginning to the Digital Era: A Brief Descriptive Review

Superimposition of craniofacial structures from radiographic examination has been always used for assessing changes in the maxilla-mandibular complexes, especially for the evaluation of potential changes occurring during growth as well as after orthodontic treatment and/or maxillofacial surgery. However, the availability of cone beam computed tomography (CBCT) and the recent advancement in 3D imaging have allowed the development of specific techniques for the registration and superimposition of virtual three-dimensional anatomical structures, improving the diagnosis and treatment plan strategies. In the present paper, it will be discussed the evolution of superimposition techniques from the beginning (2D) to the newest 3D approach, describing the most used methods and their main advantages and disadvantages, focusing primarily on accuracy and reproducibility of each technique.

Evaluation of the efficacy of celecoxib and ibuprofen on postoperative pain, swelling, and mouth opening after surgical removal of impacted third molars: a randomized, controlled clinical trial

The objective of this study was to compare the efficacy of celecoxib and ibuprofen in reducing postoperative sequelae following the surgical removal of impacted mandibular third molars. Ninety-eight subjects who needed surgical extraction of an impacted mandibular third molar were selected for the study. All subjects were randomly allocated to receive one of the following treatments twice a day for 5days after surgery: placebo (n=32), ibuprofen (n=33), or celecoxib (n=33). The primary outcome chosen was postoperative pain, which was evaluated using the visual analogue scale (VAS) score recorded by each patient. The secondary outcomes chosen were changes in postoperative swelling and maximum mouth opening values compared to preoperative ones. Compared to placebo, treatment with celecoxib and ibuprofen resulted in improvements in the primary outcome. Furthermore, when compared to the other groups, patients in the celecoxib group showed a significant reduction in postoperative pain scores at 6h (P<0.001), 12h (P=0.011), and 24h (P=0.041) after surgery. Regarding swelling and maximum mouth opening values, there were no significant differences between the groups at each follow-up session. This study demonstrated that treatment with celecoxib decreased the incidence and severity of postoperative pain following third molar surgery compared to ibuprofen and placebo.

Functional and molecular outcomes of the human masticatory muscles

The masticatory muscles achieve a broad range of different activities such as chewing, sucking, swallowing, and speech. In order to accomplish these duties, masticatory muscles have a unique and heterogeneous structure and fiber composition, enabling them to produce their strength and contraction speed largely dependent on their motor units and myosin proteins that can change in response to genetic and environmental factors. Human masticatory muscles express unique myosin isoforms, including a combination of thick fibers, expressing myosin light chains (MyLC) and myosin class I and II heavy chains (MyHC) -IIA, -IIX, α-cardiac, embryonic and neonatal and thin fibers, respectively. In this review, we discuss the current knowledge regarding the importance of fiber-type diversity in masticatory muscles versus supra- and infrahyoid muscles, and versus limb and trunk muscles. We also highlight new information regarding the adaptive response and specific genetic variations of muscle fibers on the functional significance of the masticatory muscles, which influences craniofacial characteristics, malocclusions, or asymmetry. These findings may offer future possibilities for the prevention of craniofacial growth disturbances.

Anticoagulant therapy in patients undergoing dental interventions: a critical review of the literature and current perspectives

Patients treated with oral anticoagulant therapy (OAT) represent an issue to the dentist, as an increasing number of people are using anticoagulant drugs for cardiovascular disease. The choice of an eventual suspension or continuation of anticoagulant therapy is important when considering an efficient management of the patient. Patients in anticoagulant therapy and requiring dental procedures sometimes represent therapeutic concerns especially concerning the suspension of the anticoagulant treatment. At the moment there is no consensus among international experts of a possible discontinuation of therapy before invasive dental procedures. In this paper, the authors try to focus on this topic through a critical review of the literature. Most of the studies suggest the continuation of the anticoagulant treatment with heparin before invasive oral surgical interventions. Based on the data of the literature, two rules must be adopted in clinical practice: 1) maintenance of anticoagulation related to the international normalized ratio (INR); 2) local application of antifibrinolytic agents to ensure a proper hemostatic process. Given the widespread use of anticoagulant drugs in cardiovascular disease, dentists must often face the problem of the therapy and, since there is no consensus on the management of these patients, the authors propose, after a thorough critical review of the literature, the implementation of a multiphase protocol of surgical approach to be implemented with safety in daily clinical practice.

Differential expression of transglutaminase genes in patients with chronic periodontitis

OBJECTIVE

Gingival epithelium plays a key role in the protection of oral tissues from microbial challenge, especially during the periodontal disease. This study was aimed to evaluate levels of mRNA transcripts of different forms of transglutaminase in the human gingival tissues from patients with chronic periodontitis and relative controls.

SUBJECTS AND METHODS

This study included 22 patients with chronic periodontitis (CP) and 22 healthy controls. For each patient, the values of probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) were recorded. Gene expression of transglutaminase 1, transglutaminase 2, transglutaminase 3, and metalloprotease 2 was evaluated by real-time PCR, while that of Factor XIIIA and metalloprotease 9 by RT-PCR.

RESULTS

The values of all the clinical parameters were significantly higher in the CP group than in the healthy control group (P < 0.05). In the CP group, the mRNA expression of transglutaminase 1 and transglutaminase 3 was significantly decreased in comparison with healthy control group. A slight nonsignificant changes of transglutaminase 2 gene expression were observed in samples from CP patients in comparison with controls.

CONCLUSIONS

These observations suggest that transglutaminase gene expression may be modified in response to chronic injury in the damaged gingival and emphasizes the key role of these enzymes in gingival remodelling/healing and adaptive processes.

Differences in craniofacial characteristics in Southern Italian children from Naples: a retrospective study by cephalometric analysis

AIM

The present cross-sectional survey was performed to determine cephalometric standards in a large sample (n. 1071) of children from Southern Italy (Naples).

MATERIALS AND METHODS

1071 lateral cephalograms of healthy children, between 8 to 12 years, with various types of occlusion, all with no history of orthodontic treatment before cephalometric analysis were examined. Seven angular and three linear length measurements (SNA, SNB, ANB, SN^GoMe, PN^Pal I^SN, i^GoMe), and three ratios were included. Descriptive statistics, including the mean, standard deviation, and maximum and minimum, values was computed for each cephalometric variable.

RESULTS

Changes in angular and linear parameters during the observation period occurred mostly between the ages of 10 and 12 years. The three ratios varied from age and were not characterised by a progressive rise in mean values. Se-N/Go-Pg was greater in 11-year-old boys (p <0.05) and 12-year-old boys (p <0.01); the cranio-maxillary index Se-N/PNS-A1 was greater in 9-year-old girls (p <0.05), whereas the maxilla-mandibular index PNS-A1/Go-Pg was greater in 9-year-old boys (p <0.01).

CONCLUSION

The findings provided useful reference cephalometric normative measures for the 8-to-12-year-old Southern Italian children population. Significant differences between boys and girls in the length of the anterior cranial base and ratio were reported.

Class II malocclusion division 1: a new classification method by cephalometric analysis

AIM

The purpose of this study was to analyse the craniofacial and dentofacial skeletal characteristics in untreated subjects with Class II, division 1 malocclusion by mandibular retrusion and to identify different types and their prevalence.

MATERIALS AND METHODS

In 152 subjects with Class II, division 1 malocclusion by mandibular retrusion, the differences were determined by lateral cephalograms analysis of variance and chi-square test, respectively. P<0.05 was considered significant. Seven types of mandibular retrusion were identified: three pure, dimensional, rotational and positional, and four mixed.

RESULTS

All patients showed significant inter-group differences with P between 0.005 and 0.001. The dimensional type was the most common (28.9%) and the rotational-positional type was the rarest (5.9%). The pure dimensional type had the shortest mandibular body; the pure rotational type had larger SN/GoMe and the lowest AOBO; the pure positional type presented the flattest cranial base, high AOBO. In the mixed types, dento-skeletal features changed depending on how the main types assorted.

CONCLUSIONS

Identifying the type of mandibular retrusion is important for differential diagnosis in clinical practice and research.

Phosphorylation-dependent regulation of skeletogenesis in sea urchin micromere-derived cells and embryos

Sea urchin embryo micromeres when isolated and cultured in vitro differentiate to produce spicules. Although several authors have used this model, almost nothing is known about the signaling pathways responsible for initiating skeletogenesis. In order to investigate the potential involvement of phosphorylation events in spiculogenesis, the effect of inhibitors of protein kinases and phosphatases on skeleton formation was studied. Results obtained using both cultured micromeres and embryos revealed that protein tyrosine kinase and phosphatase inhibitors blocked skeleton formation, but not serine/threonine phosphatase inhibitors. The inhibitors showed a dose-dependent effect and when removed from micromere or embryo culture, spicule formation resumed. Inhibition of tyrosine phosphatases resulted in an increase in the tyrosine phosphorylation level of two major proteins and a modest decrease in the expression of the mRNA coding for type I fibrillar collagen. These findings strongly suggest that tyrosine phosphorylation and dephosphorylation is required for micromere differentiation and for normal skeletogenesis during sea urchin embryo development.

Tamoxifen induces oxidative stress and apoptosis in oestrogen receptor-negative human cancer cell lines

Recent data have demonstrated that the anti-oestrogen tamoxifen (TAM) is able to facilitate apoptosis in cancer cells not expressing oestrogen receptor (ER). In an attempt to identify the biochemical pathway for this phenomenon, we investigated the role of TAM as an oxidative stress agent. In two ER-negative human cancer cell lines, namely T-leukaemic Jurkat and ovarian A2780 cancer cells, we have demonstrated that TAM is able to generate oxidative stress, thereby causing thiol depletion and activation of the transcriptional factor NF-kappaB. As described for other oxidative agents, TAM was able to induce either cell proliferation or apoptosis depending on the dose. When used at the lowest dose tested (0.1 microM), a slight proliferative effect of TAM was noticed in terms of cell counts and DNA synthesis rate, whereas at higher doses (10 microM) a consistent occurrence of apoptosis was detected. Importantly, the induction of apoptosis by TAM is not linked to down-regulation or functional inactivation by phosphorylation of the antiapoptotic bcl-2 protein.

Synergistic antiproliferative activity of tamoxifen and docetaxel on three oestrogen receptor-negative cancer cell lines is mediated by the induction of apoptosis

The taxanes are a promising family of anti-tumour drugs that block cell cycle replication by interfering with the microtubule network. The clinical use of these drugs involves some problems related to their low solubility and occurrence of resistance, which is mainly dependent on the multidrug-resistant (MDR) phenotype. To investigate the possible interaction between docetaxel and tamoxifen (TAM), three oestrogen receptor-negative cancer cell lines, MDR- MDA-MB 231, MDR + CEM-VBLr and MCF-7 ADRr, were used. In all three cell lines, the combination of docetaxel and TAM was more effective in terms of growth inhibition than single drug exposure. Isobolic analysis confirmed the presence of synergism in all cell lines when docetaxel was used at 0.2 microM and TAM at a dose equal to or higher than 1 microM. Flow cytometric DNA analysis performed on the three cell lines showed that TAM was able to increase the G2/M blocking activity of docetaxel. This blocking activity was followed by an increased flow cytometric DNA fragmentation suggestive of the presence of apoptosis, which was confirmed by DNA gel fragmentation and morphological analysis. While an antagonistic effect on P-glycoprotein (P-gp) activity may contribute to the synergistic effect of tamoxifen and docetaxel on CEM-VBLr and MCF-7 ADRr, other mechanisms must be involved, as the synergistic effect is also apparent with a P-gp-negative cell line.

Tamoxifen synergizes the antiproliferative effect of cisplatin in human ovarian cancer cells: enhancement of DNA platination as a possible mechanism

We investigated the chemosensitizing activity of tamoxifen (TAM) on estrogen receptor negative ovarian cancer cell lines sensitive (A2780 WT) and resistant to cisplatin (CP) (A2780 CP3). Our results showed that the treatment of both cell lines with the association TAM + CP (concentration range 0.01-1 microN and 0.1-1 microgram/ml, respectively) results in a synergistic antiproliferative activity and a complete reversal of the acquired CP-resistant phenotype. We demonstrated that in A2780 cells the addition of TAM to CP treatment is able to significantly enhance at every tested CP dose (P < 0.001) the amount of platinum (Pt) bound to the DNA. Since Pt-DNA levels in the genome are clearly related to the growth inhibitory effect of CP (correlation value = 0.97, P < 0.001) in our experimental model, we hypothesized that TAM could act synergistically with CP and overcome the acquired CP-resistance by enhancing Pt binding to the DNA. We suggest that, from a clinical point of view, TAM may be usefully included in CP-based chemotherapy regimens for ovarian cancer patients since plasma concentrations of the drug capable of in vitro CP resistance modulation are achievable in vivo. A prospective clinical trial to verify the clinical usefulness of combined TAM + CP treatment in ovarian cancer patients refractory to prior Pt-based chemotherapy is now underway in our department.

Modulatory effect of tamoxifen and ICI 182,780 on adriamycin resistance in MCF-7 human breast-cancer cells

In this study the ability of the new pure anti-estrogen ICI 182,780 to modulate the cytotoxic action of adriamycin (ADR) on parental and ADR-resistant MCF-7 (MCF-7 ADRr) human breast-cancer cells was investigated and compared with that of tamoxifen (TAM). TAM enhanced ADR cytotoxicity in MCF-7 ADRr cells in a dose-related manner, but this effect was slight or absent in MCF-7 WT. In contrast, ICI 182,780 was able to enhance ADR toxicity both in MCF-7 ADRr and in the parental cell line. ICI 182,780 was up to 2.5-fold more effective than TAM in reducing the IC50 of ADR in MCF-7 ADRr cells. Analysis of the data by the isobole method showed that the combination ADR/TAM and ADR/ICI 182,780 produced synergistic anti-proliferative activity in MCF-7 ADRr cells. Because ADR resistance in these cells is associated with the expression of high levels of P-glycoprotein (Pgp), we evaluated the effect of anti-estrogens on Pgp expression and activity. Both ICI 182,780 and TAM failed to modulate Pgp expression as assessed by flow cytometry and Western-blot analysis, performed using the monoclonal antibodies MM4.17 and C 219, which are specific for an external or an internal determinant respectively. Pgp activity was investigated by flow cytometry measuring the extrusion of ADR and the cationic dye Rhodamine 123 (Rh 123). ICI 182,780, but not TAM, reduced the activity of Pgp in MCF-7 ADRr cells. Flow cytometry was also used to investigate cell-cycle modifications induced by ADR in MCF-7 ADRr cells, both in the presence and in the absence of anti-estrogens. After 72 hr, higher doses induced an arrest of cells at the G2/M phase. The same effect was visible when lower doses of ADR were combined with ICI 182,780 or TAM. In terms of cell-cycle-blocking activity ICI 182,780 was largely more effective than TAM.

Interaction of tamoxifen with cytosolic and nuclear type II estrogen binding sites (type II EBS)

The aim of this study was to investigate the interaction of tamoxifen (TAM) with the so-called Type II estrogen binding sites (Type II EBS) in both the cytosolic and the nuclear fraction of the ER-negative A 2780 human ovarian cancer cell line and in an ER-negative ovarian cancer tissue. Although cytosolic and nuclear Type II EBS in A 2780 cells showed substantially similar binding characteristics in terms of ligand affinity and specificity, TAM, while exhibiting the ability to displace [3H]estradiol from cytosolic Type II EBS failed to interact with nuclear Type II EBS. The ability of TAM to interact only with cytosolic Type II EBS seems also to be a characteristic of ovarian cancer tissue and to be shared by several TAM metabolites. The hypothesis that the interaction of TAM with cytosolic Type II EBS could mobilize the true endogenous ligand of Type II EBS which would become available for binding to nuclear Type II EBS was tested by incubating the nuclear fraction with the cytosolic fraction. In the presence of cytosol, TAM acquires the ability to displace the tracer from nuclear Type II EBS but when the cytosolic fraction was DCC, stripped in order to remove the endogenous ligand, the competing activity of TAM for nuclear Type II EBS was abolished. Our results suggest that TAM does not interact with nuclear Type II EBS, but can favor the nuclear binding of endogenous ligand by displacing it from cytosolic Type II EBS.

Methyl-p-hydroxyphenyllactate-esterase activity and type-II estrogen-binding sites in ovarian cancer: correlation with biological and clinico-pathological parameters

We examined the levels of activity of methyl-p-hydroxyphenyllactate esterase (MeHPLA-ase) and cytosolic Type-II-estrogen-binding sites (Type-II EBS) in 61 and 71 cases, respectively, of primary ovarian cancer. MeHPLA-ase activity and Type-II EBS were seen to by asymmetrically distributed, in that levels were skewed towards the lower values. A statistically significant direct correlation was found between MeHPLA-ase activity and Type-II EBS. MeHPLA-ase activity and Type-II EBS were inversely correlated with ER and PR levels and showed a trend towards inverse correlation with the percentage of cells in S-phase of the cell cycle. MeHPLA-ase activity and Type-II EBS did not correlate with clinico-pathological parameters. The median MeHPLA-ase activity tended to be higher in responders than in unresponsive patients, but statistical significance was not reached. Higher Type-II-EBS levels were found in cases showing complete and partial response to chemotherapy than in cases which did not respond. A statistically significant relationship was found between high MeHPLA-ase activity and longer overall survival.

Tamoxifen and quercetin interact with type II estrogen binding sites and inhibit the growth of human melanoma cells

The mechanism of the antiproliferative activity of tamoxifen on melanoma cells in vitro and in vivo is poorly understood, as it is not mediated by the antiestrogenic properties of tamoxifen. Using a whole-cell assay and nuclear and cytosolic radio-binding experiments with [3H]-estradiol as tracer, we found that MNT1, M10, and M14 melanoma cell lines as well as primary tumors expressed type II estrogen binding sites that bind tamoxifen and the flavonoid quercetin with similar affinity (KD 10-25 nM). Cell count and clonogenic assay showed both compounds to inhibit melanoma cell growth in a concentration-dependent manner in the range of concentrations between 1 nM and 1 microM. Neither the pure antiestrogen ICI-182780 nor the 3-rhamnosylglucoside of quercetin, rutin, bound to type II estrogen binding sites or inhibited cell growth. Our results suggesting that tamoxifen and quercetin can inhibit melanoma cell growth by interacting with type II estrogen binding sites help explain the reported effectiveness of tamoxifen, particularly in estrogen-receptor-negative tumors, and stress the potential role of quercetin in the treatment of melanoma.

Quercetin enhances transforming growth factor beta 1 secretion by human ovarian cancer cells

Our study demonstrates that quercetin (Q)-induced growth-inhibitory activity in ovarian cancer cells may be mediated by modulation of transforming growth factor beta 1 (TGF beta 1) production. We used the OVCA 433 cell line which is very sensitive to the anti-proliferative effect of Q and expresses high-affinity, low-capacity TGF beta 1 receptors. Conditioned medium (CM) from Q-treated cells is able to displace 125I-TGF beta 1 from binding to its receptor; moreover Q (10 microM) increases TGF beta 1 activity in CM in a time-dependent fashion starting after 4 hr and reaching a maximum by 24 hr of Q treatment. Q-induced growth inhibition is reversed by a neutralizing anti-TGF beta 1 MAb both in OVCA 433 and in a clonogenic assay of cells from a primary ovarian tumor. Q-induced increase of TGF beta 1 activity in CM is specific since other anti-proliferative compounds, such as Dexamethasone, which is as active on the cell cycle as Q, had no effect on TGF beta 1 secretion. Northern-blot analysis of TGF beta 1 mRNA levels at various times of Q (10 microM) exposure revealed that there was no increase, suggesting that regulation of TGF beta 1 occurs at posttranscriptional levels.

Mechanisms and modulation of resistance to anthracyclines

This review summarizes the main mechanisms of action of anthracyclines, the mechanisms of anthracycline resistance and the possibility of their modulation by various compounds. The mechanisms of resistance to anthracyclines are multifactorial and can be summarized as follows: (i) decreased cellular drug concentration, mainly due to drug extrusion from the cell by the plasma membrane P-170 glycoprotein: (ii) defective metabolism of drug active compounds, (iii) increased drug detoxification: (iv) alteration of target proteins such as glutathione and topoisemerase II, (v) increase in the efficiency of DNA repair mechanisms. The activity of various chemosensitizers able to circumvent drug resistance acting on different resistance mechanisms has been described. Verapamil and nifedipine. active as calcium channel blockers. modulate adriamycin resistance by affecting membrane activity. Aphidicolin and novobiocin influence entracellular target sites, whereas calmodulin inhibitors and tamoxifen affect both membrane activity and intracellular structures. Since the clinical utility of any modulator depends not only on its ability to reverse drug resistance but also on its low toxicity in vivo, the selection of combinations of chemosensitizers with an acceptable toxicity would permit new approaches in cancer treatment.

Synergistic antiproliferative activity of tamoxifen and cisplatin on primary ovarian tumours

We looked for the presence of the so-called type II oestrogen binding sites (EBS), in four oestrogen (ER) and progesterone (PR) receptor negative primary ovarian tumours. Moreover, the colony-forming assay was used to evaluate the response of ovarian cancer cells from these primary tumours to tamoxifen and cisplatin used alone or in combination. All tumours contained type II EBS, and tamoxifen was able to compete for [3H] oestradiol binding to these sites. Cisplatin and tamoxifen exhibited a dose-dependent inhibition of colony formation in a range of concentrations between 10 and 1000 micrograms/l and 37 and 3710 micrograms/l, respectively. The combination of the two drugs resulted in a synergistic antiproliferative activity, with a potentiation up to and beyond 50-fold. Our results show that in ovarian cancer tamoxifen interacts with type II EBS with an affinity consistent with the concentration effective both in inhibition of colony formation and in synergising cisplatin activity. Based on the experiments performed the action of tamoxifen on cell growth is independent of ER expression, and could be mediated by type II EBS. The possibility that the association of tamoxifen and cisplatin may result in an improved clinical response in ovarian cancer should be investigated.

Atrial natriuretic peptide in trout ovarian follicles

An immunocytochemical study on atrial natriuretic peptide (ANP) was carried out in trout ovaries using an antiserum raised against human atrial natriuretic peptide (hANP). Weakly immunoreactive material was observed both in the ooplasm of the previtellogenic and the early vitellogenic oocytes and in the follicular cells of the late vitellogenic oocytes. Binding sites for hANP have been located using 125I-ANP and light-microscopic autoradiography. These studies provide evidence of specific binding of ANP-like material in both early and advanced vitellogenic oocytes. Autoradiograms indicated that the ANP-like binding sites were localized to a subpopulation of follicles. The presence of ANP-like immunoreactive material and its specific binding sites in the ovary suggest a role for atrial natriuretic peptide as a regulator of the fish ovarian function.

Chemotherapy versus tamoxifen versus chemotherapy plus tamoxifen in node-positive, estrogen receptor-positive breast cancer patients: results of a multicentric Italian study. Breast Cancer Adjuvant Chemo-Hormone Therapy Cooperative Group

Between November 1, 1983 and June 30, 1987, 510 node-positive, estrogen receptor (ER)-positive breast cancer patients have been randomly allocated to receive either chemotherapy (six intravenous [IV] cyclophosphamide, methotrexate, and fluorouracil [CMF] courses followed by four IV epirubicin courses) or 5 years of tamoxifen treatment or a combination of both therapies. After a median follow-up of 40 months, patients receiving the combined treatment achieved the best results, and those treated with chemotherapy alone achieved the worst, the difference being particularly evident in postmenopausal women. However, while the concurrent use of chemotherapy and tamoxifen did improve the results achieved by chemotherapy alone, particularly in postmenopausal women and in those with four or more involved nodes, it did not significantly improve the results achieved by tamoxifen alone, particularly in patients with higher ER tumor concentrations. Side effects were more numerous and more severe in patients receiving chemotherapy (with or without tamoxifen). Our findings, although still preliminary, confirm that tamoxifen should be the treatment of choice for postmenopausal breast cancer patients with node-positive, ER-positive tumors. In addition, the findings suggest that tamoxifen may represent a safe alternative to chemotherapy (at least to the cytotoxic regimen we used) for younger women, provided they have ER-positive tumors. In patients with ER-positive tumors, the addition of chemotherapy to tamoxifen does not seem to improve significantly the effectiveness of tamoxifen alone.

Plasma aldosterone in newborn and adult Vipera aspis

In the venomous viviparous snake Vipera aspis, plasma aldosterone concentration shows significant seasonal changes mainly related to temperature-dependent behavior. A difference is also present between newborns and adults. A correlation between sodium and potassium status and aldosterone plasma level in active and inactive life is suggested.

Effect of hypophysectomy on plasma electrolytes and adrenal mineralocorticoid secretion in the terrestrial chelonian Testudo hermanni

Na, K, ACTH, corticosterone and aldosterone plasma levels were studied in Testudo hermanni after hypophysectomy and dexamethasone administration. Hypophysectomy as well as dexamethasone treatment caused a deep decrease in the plasma levels of electrolytes, corticosterone and aldosterone when compared to sham-operated or normal controls. ACTH plasma level was markedly lower in hypophysectomized or dexamethasone-treated tortoises when compared to the controls but never reached undetectable levels. Administration of ACTH significantly increased plasma electrolytes and hormone levels in hypophysectomized and dexamethasone-treated tortoises. The present data seem to indicate that the pituitary plays a significant role on electrolyte homeostasis and on the regulation of plasma mineralocorticoids level in terrestrial chelonians.

[Contamination of the operating room with anesthetic gases and vapors. Analytical methods]

An approach for the measurement of the contamination of the operating room air is presented. The measurements were performed in three operating rooms used for general surgery, partly in model experiments and partly while anesthesia was in progress. During anesthesia, the measurements were taken when oxygen 3 l/min containing ethrane 1.0--1.5% was passed into a semi-closed circle and the exhaled gas vented directly to the environmental air with no scavenging system in use. The daily exposure of operating room personnel was determined by adsorption of ethrane on glass tubes containing activated charcoal. The ethrane was subsequently desorbed in toluol and quantified by gas chromatography. The concentration of contaminant was found to be significantly greater in the anesthesiologist's position than in the areas of surgeon and circulating nurse. Some pitfalls in sampling, standardization, and analysis are indicated. Attention is drawn to the numerous factors influencing the extent of contamination.

beta-Glucuronidase activity in the developing uropygial gland

The presence of sterolic compounds and beta-glucuronidase activity have been studied in the uropygial glands of chick embryos (18th day of inc.), chickens (3 weeks after hatching) and young fowls (5 months old). Sterols are histochemically detectable only after hatching and beta-glucuronidase activity, very faint before hatching, reaches its maximum in chicken glands with a peculiar inner localization coincident with sterolic localization. It is suggested that beta-glucuronidase has in uropygial gland a double functional significance: a certain amount of activity is developed to cell proliferation whereas a more strong activity is involved in the hydrolysis of sterol glucuronides.