A hybrid thyroid tumor type classification system using feature fusion, multilayer perceptron and bonobo optimization

BACKGROUND

Thyroid tumor is considered to be a very rare form of cancer. But recent researches and surveys highlight the fact that it is becoming prevalent these days because of various factors.

OBJECTIVES

This paper proposes a novel hybrid classification system that is able to identify and classify the above said four different types of thyroid tumors using high end artificial intelligence techniques. The input data set is obtained from Digital Database of Thyroid Ultrasound Images through Kaggle repository and augmented for achieving a better classification performance using data warping mechanisms like flipping, rotation, cropping, scaling, and shifting.

METHODS

The input data after augmentation goes through preprocessing with the help of bilateral filter and is contrast enhanced using dynamic histogram equalization. The ultrasound images are then segmented using SegNet algorithm of convolutional neural network. The features needed for thyroid tumor classification are obtained from two different algorithms called CapsuleNet and EfficientNetB2 and both the features are fused together. This process of feature fusion is carried out to heighten the accuracy of classification.

RESULTS

A Multilayer Perceptron Classifier is used for classification and Bonobo optimizer is employed for optimizing the results produced. The classification performance of the proposed model is weighted using metrics like accuracy, sensitivity, specificity, F1-score, and Matthew's correlation coefficient.

CONCLUSION

It can be observed from the results that the proposed multilayer perceptron based thyroid tumor type classification system works in an efficient manner than the existing classifiers like CANFES, Spatial Fuzzy C means, Deep Belief Networks, Thynet and Generative adversarial network and Long Short-Term memory.

EXPRESSION OF ALPHA-SMOOTH MUSCLE ACTIN IN ODONTOGENIC CYSTS AND TUMORS

BACKGROUND

Odontogenic cysts and tumors exhibit different degrees of aggressiveness in their biological behavior. There has been evidence that the presence of myofibroblasts (MFs) at the invasion front promotes tumor invasion. Our study is based on the fact that MFs are important in the biological behavior of odontogenic cysts and tumors.

AIM

To assess immunohistochemically expression of alpha-smooth muscle actin (α-SMA) of MFs in odontogenic cysts and tumors and correlate this expression to their biological behavior.

MATERIALS AND METHODS

The archival tissues collected for 1.5 years were obtained from the Department of Oral Pathology & Microbiology, People's Dental Academy, Bhopal (India). A total of 40 cases consisting of 10 cases each of odontogenic keratocysts, radicular cysts, dentigerous cysts and ameloblastomas formed the study group. An immunohistochemical analysis of α-SMA expression and localization was carried out.

RESULTS

Mean MF counts were the highest in odontogenic keratocysts which was followed by ameloblastomas, entigerous cysts and radicular cysts. Weak α-SMA-expression was found in 50% of cases, moderate in 22.5% of cases, and intense - in 10% cases. MFs were arranged in the spindle, focal, or network patterns in 35; 27.5 and 20% of cases, respectively.

CONCLUSION

The analysis revealed that the MFs were distinctly heterogeneous in distribution and pattern of arrangement. This provided persuasive evidence that stroma of these lesions harbor MFs as reflected by α-SMA immunopositive cells.

Morphometric analysis of collagen in different grades of oral squamous cell carcinoma using picrosirius red stain and spectrophotometry

Introduction

Oral squamous cell carcinoma (OSCC) is one of the most formidable health problems for mankind. These carcinomas are characterized by invasion of epithelial tumor cells into the stroma, which get embedded in extracellular matrix and collagen producing reactive changes. Such changes in the stroma may alter the biological aggressiveness of the tumor. An attempt was made to evaluate the collagen changes in different grades of OSCC which can contribute to understanding the biologic behavior of oral cancer and predict clinical outcomes.

Aims and Objectives

To assess the quantitative changes in collagen in different grades of OSCC using hematoxylin and eosin (H and E) and Picrosirius red (PSR) stain through spectrophotometry and to compare the efficacy of these stains for estimation of collagen.

Materials and Methods

The study comprised a total sample size of 60, which were distributed under 4 different groups, each containing 15 samples. Group I to IV consisted of normal buccal mucosa, with well-, moderately-, and poorly-differentiated OSCC, respectively. The tissues of 10 μm thickness were stained with H and E and PSR for spectrophotometric analysis.

Results

The quantity of collagen decreased with increasing grades of OSCC. Comparison between two stains showed that PSR can provide a more reliable and accurate result than H and E.

Conclusion

Collagen estimation is one of the methods to assess the progression of tumor. The method used in the present study for collagen estimation in different grades of OSCC is reliable and accurate.

Surveillance of COVID-19 Using Geospatial Data: An Emergency Department Perspective

Background

The outbreak of coronavirus 2019 (COVID-19) which emerged in December 2019 spread rapidly and created a public health emergency. Geospatial records of case data are needed in real time to monitor and anticipate the spread of infection.

Methods

This study aimed to identify the emerging hotspots of COVID-19 using a geographic information system (GIS)-based approach. Data of laboratory-confirmed COVID-19 patients from March 15 to June 12, 2020, who visited the emergency department of a tertiary specialized academic hospital in Dubai were evaluated using ArcGIS Pro 2.5. Spatiotemporal analysis, including optimized hotspot analysis, was performed at the community level.

Results

The cases were spatially concentrated mostly over the inner city of Dubai. Moreover, the optimized hotspot analysis showed statistically significant hotspots (p < 0.01) in the north of Dubai. Waxing and waning hotspots were also observed in the southern and central regions of Dubai. Finally, there were nonsustaining hotspots in communities with a very low population density.

Conclusion

This study identified hotspots of COVID-19 using geospatial analysis. It is simple and can be easily reproduced to identify disease outbreaks. In the future, more attention is needed in creating a wider geodatabase and identifying hotspots with more intense transmission intensity.

Management Guidelines for Infection After ACL Reconstruction: Expert Opinion Statement Based on the Modified Delphi Survey of Indian Arthroscopy Surgeons

AIM

Infection after anterior cruciate ligament (ACL) reconstruction, though rare, is a potentially devastating complication and the evidence-based recommendation on the various topics in its management is limited. The purpose of this study was to develop recommendations for the prevention and management of infections in ACL reconstruction surgery by performing a structured expert consensus survey using Delphi methodology.

MATERIALS AND METHODS

22 topics of relevance in the prevention and management of infection following ACL reconstruction were chosen from an extensive literature review. 30 panelists were requested to respond to a three-round survey, with feedback, to develop a consensus statement on the topics.

RESULTS

Consensus statements could be prepared in eleven out of twenty-two topics including: the graft is retained at the first arthroscopic debridement, the graft is removed when repeated debridement are needed, and revision ACL reconstruction is needed only if the patient develops instability. Concurrence could be obtained in the topics including: longer duration of antibiotics is needed in immunocompromised patients, soaking graft in antibiotic solution reduces infection risk, and knee swelling without warmth does not suggest infection.

CONCLUSIONS

A proper skin preparation, a longer course of antibiotics in immunocompromised patients, and soaking the graft in antibiotics reduces the risk of infection. In case of infection, a healthy-looking graft must be retained at the first debridement and if the graft must be removed, revision ACL reconstruction is advised only if the patient develops instability.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-021-00363-z.

Phylogenetic Relationship Among Brackishwater Vibrio Species

Vibriosis is regarded as an important disease of penaeid shrimps affecting larvae in hatcheries. Among the Vibrio species, Vibrio parahaemolyticus, Vibrio vulnificus, Vibrio furnissii, Vibrio campbellii, Vibrio harveyi, Vibrio alginolyticus, and Vibrio anguillarum are often associated with diseases in finfish and shellfish of brackishwater ecosystem. Accurate species differentiating methods for the organisms present in an ecosystem are required for precise classification of the species and to take steps for their management. Conventional methods like 16s rRNA phylogeny and multilocus sequence typing (MLST) have often failed to correctly identify Vibrio species. This has necessitated a comprehensive investigation on methodologies available to distinguish Vibrio species associated with brackishwater aquaculture system. To achieve this, 35 whole genomes belonging to 7 Vibrio species were subjected to phylogenetic analysis based on 16s rRNA gene, MLST genes, single-copy orthologous genes, and single-nucleotide polymorphisms. In addition, genome-based similarity indices like average nucleotide identity (ANI) and in silico DNA-DNA hybridization (DDH) were computed as confirmatory tests to verify the phylogenetic relations. There were some misclassifications occurred regarding phylogenetic relations based on 16s rRNA genes and MLST genes, while phylogeny with single-copy orthologous genes produced accurate species-level clustering. Study reveals that the species identification based on whole genome-based estimates or genome-wide variants are more precise than the ones done with single or subset of genes.

Oral malignant melanoma

Malignant melanoma in the head and neck area is rare. The incidence of oral malignant melanomas of the head and neck is approximately four per 10 million populations per year. They are derived from epidermal melanocytes and are most frequently seen on the palate and maxillary gingiva. They are asymptomatic initially but become painful with progress and enlargement. Later, they are associated with ulceration, bleeding, mobility of tooth, paresthesia and ill-fitting prosthesis. The diagnosis is often delayed due to silent growth and development of the lesion. Oral malignant melanomas are associated with poor prognosis due to their invasive and metastasizing tendencies. This case report is presented to emphasize the role of a dentist in identifying the pigmented lesions of the oral cavity.

Indole fragments for the design of lead molecules against pancreatitis

Communicated by Ramaswamy H. Sarma.

Assessing Difficulties Encountered by Dental Students Studying Oral Pathology and Addressing Their Concerns

INTRODUCTION

The present scenario of Oral Pathology and Oral Histology as a subject is alarming. In spite of so many advancements in terms of books, internet and conferences there are still lacunae between the understanding and interest for the subjects in the students. It can be partly due to the fact that the students perceive it as a non-clinical subject having a lesser scope for practice.

AIM

The present study was aimed at evaluating the students approach towards oral pathology department and the subject. The purpose of the study was to analyze practical hurdles encountered by students and to find out solutions to overcome them.

MATERIALS AND METHODS

The cross-sectional questionnaire based study was done with BDS students of People's Dental Academy, Bhopal, India, to gauge the understanding of their knowledge in the subject of Oral Pathology and Oral Histology. Questionnaire comprised of 28 multiple choice questions under five parameters. The data recorded was subjected to statistical analysis using chi-square test.

RESULTS

We found that study samples were efficient enough in terms of following instructions related to their day to day training. Although they were content with light microscope, they thought that some more interactive sessions could be beneficial for them in Oral Pathology.

CONCLUSION

Through our study we found out that the students are well oriented on the whole about Oral Pathology. They certainly encounter difficulties which are easy to handle if proper measures are taken. We through our study would like the readers to be aware of the changing trends in teaching and to incorporate them routinely.

Assessment of Tumor Cell Cannibalism as a Predictor of Oral Squamous Cell Carcinoma - A Histopathologic Correlation

AIM

Cellular cannibalism is defined as the ability of a cell to engulf another cell of its own type or any other. It has been recognized in various malignancies and is linked well with the aggressiveness, degree of anaplasia, invasiveness and metastatic potential. Literature search fetched up very few studies related to the presence and significance of cannibalism with respect to Oral squamous cell carcinoma [OSCC]. The present study was aimed to detect tumor cell cannibalism in OSCC and to validate its role as a prognosticator of OSCC in relation to metastasis and degree of differentiation.

METHOD

30 histopathologically proven cases, 15 cases each of metastatic OSCC (7 well differentiated OSCC and 8 moderately differentiated OSCC) and non-metastatic OSCC (8 well differentiated OSCC and 7 moderately differentiated OSCC) were included in the study. Quantitative assessment of tumor cell cannibalism was done. The data was analyzed using Mann Whitney test.

RESULT

Metastatic OSCC showed higher frequency of cannibalistic cells compared to non-metastatic OSCC. More number of cannibalistic cells were found in moderately differentiated OSCC than well differentiated OSCC in both groups. Moreover, Grade III cannibalism and complex cannibalism was also found to be associated with metastatic, moderately differentiated OSCC exclusively.

CONCLUSION

It has been found that higher number of cannibalistic cells were associated with OSCC showing metastasis indicating their aggressive behavior. So, we recommend that quantitative assessment of tumor cell cannibalism should become a part of the routine histopathological examination of OSCC to screen its hostile behavior.

Brain-Derived Neurotrophic Factor Facilitates Functional Recovery from ALS-Cerebral Spinal Fluid-Induced Neurodegenerative Changes in the NSC-34 Motor Neuron Cell Line

BACKGROUND

The survival of motor neurons is dependent upon neurotrophic factors both during childhood and adolescence and during adult life. In disease conditions, such as in patients with amyotrophic lateral sclerosis (ALS), the mRNA levels of trophic factors like brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1), fibroblast growth factor-2 (FGF-2), and vascular endothelial growth factor are downregulated. This was replicated in our in vivo experimental system following the injection of cerebral spinal fluid (CSF) of sporadic ALS (ALS-CSF) patients.

OBJECTIVE

To evaluate the protective role of BDNF in a model of sporadic ALS patients.

METHODS

The expressions of endogenous BDNF, its receptor TrkB, the enzyme choline acetyl transferase (ChAT), and phosphorylated neurofilaments were studied in NSC-34 cells. The calcium-buffering and proapoptotic effects were assessed by calbindin-D28K and caspase-3 expression, respectively.

RESULTS

ALS-CSF considerably depleted the endogenous BDNF protein, while its effect on IGF-1 and FGF-2 was inconsequential; this indirectly indicates a key role for BDNF in supporting motor neuronal survival. The exogenous supplementation of BDNF reversed autocrine expression; however, it may not be completely receptor mediated, as the TrkB levels were not restored. BDNF completely revived ChAT expression. It may inhibit apoptosis by restoring Ca2+ homeostasis, since caspase-3 and calbindin-D28K expression was back to normal. The organellar ultrastructural changes were only partially reversed.

CONCLUSION

Our study provides evidence that BDNF supplementation ameliorates most but not all degenerative changes. The incomplete revival at the ultrastructural level signifies the requirement of factors other than BDNF for near-total protection of motor neurons, and, to an extent, it explains why only a partial success is achieved in clinical trials with BDNF in ALS patients.

Peripheral ossifying fibroma: A rare case affecting maxillary region

Focal gingival enlargements are a diverse group of lesions with almost similar clinical presentation but varied etiology and histopathology. The actual cause of peripheral ossifying fibroma (POF) has been debated over many years. POFs are usually seen in childhood and younger ages. There is a slight female predilection. It is usually localized, rarely generalized. Usually, the treatment option is only surgical excision with minimal chances of recurrence. Here, we report a case of POF of the right maxillary posterior region with a review of literature.

Internal jugular phlebectasia as an incidental finding in cervical spine surgery

Idiopathic internal jugular phlebectasia, occurs either unilaterally or bilaterally affecting the internal jugular vein is a rare congenital variation often diagnosed during childhood. It usually presents with a benign swelling over the lateral side of neck on the affected side, seen on exertion. A-30-year old male was operated for anterior cervical dissectomy from right lateral approach and was diagnosed per-operatively as internal jugular phlebectasia. The surgery was abandoned at this stage on the advice of cardiothoracic surgeon to investigate the patient for the secondary etiological factors for internal jugular vein dilatation. The patient was reassured without any active intervention for the phlebectasia and cervical dissectomy was performed in the second surgery through the lateral approach from left side. This case is presented in view of rarity and suggested that during preoperative workup the nearby structures like carotid sheath should be evaluated by magnetic resonance imaging to avoid such per-operative surprises.

Structural identification and characterization of potential impurities of pantoprazole sodium

Six impurities in pantoprazole sodium bulk drug substance were detected by a simple high performance liquid chromatographic method (HPLC) whose area percentage ranged from approximately 0.05 to 0.34%. Liquid chromatography-mass spectrometry (LC-MS) was performed to identify the molecular weight of the impurities. A thorough study was undertaken to characterize these impurities. These impurities were synthesized, subsequently characterized and were co-injected with the sample containing impurities and found the retention time match of the spiked impurities. Based on their spectral data (IR, NMR and MS), these impurities were characterized as; 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridinyl)methyl]thio]-1H-benzimidazole (Impurity-I); 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridinyl)methyl]sulfonyl]-1H-benzimidazole (Impurity-II); 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-1-oxide-2-pyridinyl)methyl]sulfonyl]-1H-benzimidazole (Impurity-III); 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridinyl)methyl]thio]-1-((3,4-dimethoxy-2-pyridinyl)methyl)-1H-benzimidazole (Impurity-IV); 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridinyl)methyl]sulfinyl]-1-((3,4-dimethoxy-2-pyridinyl)methyl)-1H-benzimidazole (Impurity-V); 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-1-oxide-2-pyridinyl)methyl]sulfinyl]-1H-benzimidazole (Impurity-VI). The formation of these impurities was proposed. The structure of the Impurity-II was unambiguously confirmed by single crystal X-ray diffraction (XRD) studies.

Field screening and evaluation of pigeonpea genotypes against podborer (Helicoverpa armigera)

Hence an experiment was conducted to screen fifteen germplasm lines for their resistance/tolerance to podborer under natural infestation in pesticide-free open field. To asses the degree of infestation 250 green pods were randomly picked up from all the plants of each plot. The pods damaged by gram podborer were detected by the presence large bored holes in pods. Such infested and healthy pods were counted separately. The pod damage (%) was calculated on the basis of number of pods examined and the number of infested pods. Marketable green pod yield of each genotype under natural pest infestation was also recorded. On the basis of mean infestation, ICP13201 showed the lowest (25%) pod damage and showed lowest susceptibility among the genotypes studied. It was followed by ICP13208 and ICP11964 showed lower pod damage. The rest of the genotype suffered higher pod damage to Helicoverpa armigera. Considering the yield potential ICP13201, ICP13214 and ICP13212 showed higher yield potential than other genotypes. Considering the lower susceptibility to Helicoverpa armigera and higher yield potential ICP13201 was found to be the best.

Malignant fibrous histiocytoma of the spermatic cord

Malignant fibrous histiocytoma (MFH) of the spermatic cord is rare. However, owing to its location it is diagnosed early and has a better prognosis. A case of MFH of the spermatic cord is reported in a 50-year-old male along with review of the literature, discussing the recommended management and prognosis of this condition and emphasising upon its clinical recognition since the prognosis and management are different from the MFH, in general.

Recurrent osteoid osteoma: a case report with imaging features

We present a case of a 14-year-old boy, who presented with pain in the left thigh region for 1 year. The pain exacerbated at night, waking up the child and was relieved by salicylates. On the basis of clinical history, conventional radiography, computerized tomography and bone scintigraphy, a diagnosis of osteoid osteoma was made. The tumor was completely excised, and there was complete remission of symptoms. Six months following surgery, the pain recurred in the same region. Conventional radiography revealed dense sclerosis at the surgical site. Three-phase skeletal scintigraphy showed a focal area of increased blood pool activity followed by intense focal uptake in delayed images, characteristic of osteoid osteoma. Computerized tomography confirmed the findings of skeletal scintigraphy.

Prevalence of neuropathy in type 2 diabetic patients attending a diabetes centre in South India

OBJECTIVE

The aim of this study was to determine the prevalence and risk factors for neuropathy among South Indian type 2 diabetic patients attending a diabetes centre.

METHODS

One thousand consecutive type 2 diabetic patients attending a diabetes centre in South India were recruited for the study. Biothesiometry studies were performed by a single observer using a biothesiometer. Neuropathy was diagnosed if the vibratory threshold of the great toe exceeded twenty five.

RESULTS

Overall, 19.1% of the patients had evidence of neuropathy. The prevalence of neuropathy increased with increase in age (p < 0.001) and duration of diabetes (p < 0.001). Multiple logistic regression analysis revealed age (OR--3.2, 95% confidence interval--2.7-4.1, p < 0.001) and duration of diabetes (OR--1.4, 95% confidence interval--1.2-64, p = 0.001) as the risk factors for neuropathy.

CONCLUSION

The overall prevalence of neuropathy in this South Indian type 2 diabetic subjects is 19.1% and age and duration of diabetes are the risk factors for neuropathy.

Pitfalls in the diagnosis of epithelioid sarcoma presenting in an unusual site: a case report

The cytologic appearance of epithelioid sarcoma in fine-needle aspiration biopsy cytology (FNABC) smears has not been extensively described. We report a case of epithelioid sarcoma in a 55-year-old male who presented with nodular swellings in the abdominal wall and scrotum. The scrotal swelling was subsequently demonstrated to arise from the vas deferens. We highlight the cytomorphologic, immunocytochemical, and histopathologic features of this rare lesion in an unusual site, with particular emphasis on the dilemma encountered in the cytodiagnosis of this lesion.

Histopathology and immunohistochemistry of pancreatic islets in fibrocalculous pancreatic diabetes

The histopathology of Fibrocalculous Pancreatic Diabetes (FCPD) has been extensively studied, but there are no reports on alteration in patterns of hormone secreting cells using immunohistochemistry in islets of FCPD patients. In this study, we report on the histopathology and immunohistochemistry of islets of FCPD patients and its possible correlation with the clinical picture. Pancreatic biopsies were carried out in six patients with FCPD at the time of surgery for abdominal pain. Routine histopathology and immunohistochemistry studies were carried out with six primary antibodies namely insulin, glucagon, pancreatic polypeptide (PP), somatostatin, vasoactive intestinal peptide and gastrin. Histopathology of the pancreas showed a spectrum of changes ranging from moderate to severe atrophy, fibrosis of the parenchyma and degeneration of the ducts. Nesidioblastosis was present in three patients. Immunohistochemical studies showed a decrease in the number of islets but some patients showed evidence of hyperplasia. There was an overall decrease in the percent of insulin cells and the positivity in the islets correlated with plasma C-peptide levels and the duration of diabetes. There was no consistent relationship with glucagon with some patients showing increased and other decreased positivity. There was a marked decrease in PP and somatostatin positivity, the significance of which is not clear. The reduction, but partial preservation of insulin positivity is consistent with the ketosis resistance shown by patients with Fibrocalculous Pancreatic Diabetes.

Lipid peroxidation, free radical production and antioxidant status in breast cancer

Reactive oxygen metabolites (ROMs), including superoxide anion (O2*-), hydrogen peroxide (H2O2) and hydroxyl radical (*OH), play an important role in carcinogenesis. There are some primary antioxidants such as superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) which protect against cellular and molecular damage caused by the ROMs. We conducted the present study to determine the rate of O2*- and H2O2 production, and concentration of malondialdehyde (MDA), as an index of lipid peroxidation, along with the SOD, GPx and CAT activities in 54 breast cancer (BC) patients. Forty-two age- and sex-matched patients with minor surgical problems, who had no history of any neoplastic or breast disorders, were taken as controls. The rate of O2*- production was significantly higher (p < 0.001) in BC patients than controls, irrespective of clinical stages and menopausal status. Similarly, H2O2 production was significantly higher in BC patients, especially in stage III and postmenopausal groups, as compared to the respective controls. MDA concentration was also observed significantly elevated in stage II (p < 0.001), stage III (p < 0.01), postmenopausal (p < 0.005), and premenopausal (p < 0.02) group as compared to their corresponding controls. SOD and GPx activities were found significantly raised in all the groups (p < 0.001), except the GPx activity was found a smaller alteration in stage IV (p < 0.02). On the contrary, CAT activity was found significantly depressed in all the study groups. The maximum depression was observed in stage II (-61.8%). Lower CAT activity in our study may be the effect of higher production of ROMs, particularly O2*- and *OH. SOD and GPx, however, were less effected by these higher ROMs production. The results of our study have shown a higher ROMs production and decreased CAT activity, which support the oxidative stress hypothesis in carcinogenesis. The relatively higher SOD and GPx may be due to the response of increased ROMs production in the blood. However, the higher SOD and GPx activities may be inadequate to detoxify high levels of H2O2 into H2O leading to the formation of the most dangerous *OH radical followed by MDA. Therefore, administration of CAT may be helpful in the management of BC patients. However, further elaborate clinical studies are required to evaluate the role of such antioxidant enzymes in BC management.

Vitamin D receptor interactions with the rat parathyroid hormone gene: synergistic effects between two negative vitamin D response elements

Vitamin D response elements (VDREs) that are required for negative regulation of rat parathyroid hormone (rPTH) gene expression have been characterized. Gel mobility shift assays using DNA restriction enzyme fragments and recombinant proteins for vitamin D and retinoic acid X receptors (VDR/RXR) revealed a sequence between -793 and -779 that bound a VDR/RXR heterodimer with high affinity (VDRE1). Furthermore, a lower affinity site (VDRE2) was detected that acted in combination with VDRE1 to bind a second VDR/RXR complex. As determined by ethylation interference analysis, the nucleotide sequence of VDRE1 consisted of GGTTCA GTG AGGTAC, which is remarkably similar to the sequence of the negative VDRE found in the chicken PTH (cPTH) gene. Using the same technique, VDRE2 was identified between positions -760 and -746 and contained the sequence AGGCTA GCC AGTTCA. Functional analysis was determined by transfection studies with plasmid constructs that expressed the gene for chloramphenicol acetyl transferase (CAT). The ability of the VDREs to regulate gene expression was tested in their native context with the rPTH promoter as well as when positioned immediately upstream from the cPTH promoter. With either plasmid construct, exposure to 10(-8)M 1,25(OH)2D3 resulted in a 60-70% decrease in CAT gene expression when both VDRE1 and VDRE2 were present. Examination of the individual VDREs showed that inhibition by 10(-8) M 1,25(OH)2D3 was only 35-40% when just VDRE1 was present. By itself, VDRE2 was even less effective, as significant inhibition of CAT activity (20%) was observed only in the presence of higher concentrations of 1, 25(OH)2D3 (10(-7)M) or when a plasmid vector that overexpressed the VDR protein was cotransfected. In conclusion, the rPTH gene contains two negative VDREs that act in concert to bind two RXR/VDR heterodimer complexes and that both VDREs are required for maximal inhibition by 1,25(OH)2D3.

Ca2+-induced increases in steady-state concentrations of intracellular calcium are not required for inhibition of parathyroid hormone secretion

It has been well established that increases in extracellular calcium concentration ([Ca2+]) inhibit parathyroid hormone (PTH) secretion. The effects of [Ca2+] are mediated through a G-protein-coupled receptor that has been cloned and characterized. Additionally, it has been demonstrated in parathyroid cells that an increase in [Ca2+] results in an increase in steady-state levels of intracellular calcium ([Ca2+]i). At present, it has not been fully resolved whether changes in [Ca2+]i are related to changes in PTH secretion. In the current study, the effect of increased [Ca2+] on PTH secretion and the connection regarding changes in concentrations of intracellular calcium [Ca2+]i have been examined in primary cultures of bovine parathyroid cells. PTH secretion was measured by radioimmunoassay and intracellular calcium was determined by single cell calcium imaging. Bovine parathyroid cells pre-incubated with either 0.5 or 1 mM calcium responded to rapid increases in [Ca2+] (> or = 0.5 mM) with an immediate and sustained increase in steady-state levels of [Ca2+]i that persisted for time intervals greater than 15 minutes. Although the magnitude of the sustained increase in [Ca2+]i varied among individual cells (approximately 40% to > 300%), the overall pattern and course of time were similar in all cells examined (n = 142). In all trials, [Ca2+]i immediately returned to baseline levels following the addition of the calcium chelator, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). Additional control studies, however, suggest that sustained increases in [Ca2+]i do not correlate with regulation of parathyroid hormone secretion. Sustained elevations of [Ca2+]i were not observed when [Ca2+] was gradually increased by the addition of 0.1 mM increments at 1 minute intervals. Furthermore, the effect on inhibition of PTH secretion was the same regardless of whether [Ca2+] was increased by gradual or rapid addition.

Turning a negative into a positive: vitamin D receptor interactions with the avian parathyroid hormone response element

1 ,25-Dihydroxyvitamin D3 [1,25-(OH)2D3] negatively regulates expression of the avian PTH (aPTH) gene transcript, and a vitamin D response element (VDRE) near the promoter of the aPTH gene had previously been identified. The present report assessed whether the negative activity imparted by the aPTH VDRE could be converted to a positive transcriptional response through selective mutations introduced into the element. The tested sequences were derived from individual and combined mutations to 2 bp in the 3'-half of the direct repeat element, GGGTCAggaGGGTGT. Cold competition experiments using mutant and wild-type oligonucleotides in the mobility shift assay revealed minor differences in the ability of any of these sequences to compete for binding to a heterodimer complex comprised of recombinant proteins. Ethylation interference footprint analysis for each of the mutants produced unique patterns over the 3'-half-sites that were distinct from the weak, wild-type footprint. Transcriptional outcomes evaluated from a chloramphenicol acetyltransferase reporter construct utilizing the aPTH promoter found that the individual T-->A mutant produced an attenuated negative transcriptional response while the G-->C mutant resulted in a reproducibly weak positive transcriptional outcome. The double mutant, however, yielded a 4-fold increase in transcription, similar to the 7-fold increase observed from an analogous construct using the human osteocalcin VDRE. UV light crosslinking to gapped oligonucleotides assessed the polarity of heterodimer binding to the wild-type and double mutant sequences and was consistent with the vitamin D receptor preferentially binding to the 5'-half of both elements. Finally, DNA affinity chromatography was used to immobilize heterodimer complexes bound to the wild-type and double mutant sequences as bait to identify proteins that may preferentially interact with these DNA-bound heterodimers. This analysis revealed the presence of a p160 protein that specifically interacted with the heterodimer bound to the wild-type VDRE, but was absent from complexes bound to response elements associated with positive transcriptional activity. Thus, the sequence of the individual VDRE appears to play an active role in dictating transcriptional responses that may be mediated by altering the ability of a vitamin D receptor heterodimer to interact with accessory factor proteins.

The chemokine interleukin-8 regulates parathyroid secretion

Interleukin-8 (IL-8) is a chemokine important in inflammatory processes. Homology cloning experiments performed using bovine parathyroid cDNA and degenerate primers encoding transmembrane regions III and VI of peptide and protein hormone G-protein coupled receptors identified a set of known receptors not previously identified in the parathyroid. Among these was the IL-8 type B receptor. Incubation of freshly isolated bovine parathyroid cells with recombinant IL-8 for 6-48 h produced an increase in the levels of mRNA for parathyroid hormone (PTH). The levels of PTH secreted in response to nanomolar amounts of IL-8 were also elevated in cells incubated for 1 h with IL-8. Differential display analysis of mRNA from parathyroid cells, incubated in the presence and absence of IL-8, permitted the identification of cDNA clones for RNA species whose expression was either elevated or suppressed. These experiments suggest that IL-8 and inflammatory events play a role in bone homeostasis through actions on the parathyroid gland.

Fine needle aspiration cytology of well-differentiated papillary peritoneal mesothelioma. Report of a case

The fine needle aspiration cytologic findings in a well-differentiated multifocal papillary peritoneal mesothelioma in a young man presenting with abdominal pain and mass are described. The patient is alive and well 50 months after the onset of symptomatology. The cytologic and histologic appearance as well as the clinical course of the patient point to a benign multifocal mesothelioma.