Volatile profiling as a potential biochemical marker for validation of gamma irradiation derived putative mutants in polyembryonic genotypes of mango (Mangifera indica L.)

Introduction

Putative mutants were generated through gamma irradiation in the polyembryonic mango genotype Nekkare. The putative mutant progenies along with control seedlings and mother plants were evaluated by comparing the compositions and relative proportions of their major volatile compounds.

Methods

Volatile profiling was done using headspace-solid phase micro-extraction (HS SPME) method coupled with gas chromatography-mass spectrometry (GC-MS MS). Furthermore, characterisation of putative mutants and control seedlings was carried out using simple sequence repeat (SSR) markers to ascertain the genetic diversity present in the samples under study.

Results

Monoterpenes were the most abundant volatile compound in all the studied samples (ranging from 34.76% to 91.41%) out of which I-Phellandrene and cis-Ocimene formed the major fraction in mother plants (20.45%-21.86% and 16.17%-21.27%, respectively) and control seedlings (23.32%-24.95% and 18.95%-20.81%, respectively), while beta-Phellandrene was dominant in the selected putative mutant samples (2.34%-29.53%). Among sesquiterpenes, trans-Caryophyllene was detected only in the putative mutant samples (0.10%-30.18%). Grouping together of mother plants and control seedlings was seen in the cluster analysis, while the putative mutants grouped apart from them suggesting genetic diversity. Genetic distance between the mother plants and control seedlings ranged from 0.97 to 2.73, while between putative mutants, control seedlings, and mother plants, it ranged from 6.54 to 9.82. SSR-based characterisation of putative mutant seedlings showed that mutation caused variability in the treated population. This was evident from the high allelic richness ranging from 4 to 12 with a mean of 7 and a higher mean Shannon's Information Index (1.50) of the putative mutant population.

Discussion

The study demonstrates that volatile profiling and molecular characterisation using SSR markers could be used as a tool to detect variation in a mutated population. In addition, volatile profiling can be used to validate putative mutants in polyembryonic mango genotypes where the seedlings of nucellar origin are similar to mother plants.

Determining the best anti-microbial properties of dental cements used for pulp capping procedures using deep dentinal carious material

Introduction

The exposure of the healthy pulp in cases of deep dentinal caries (DDC) that contain carious microorganisms can be prevented by placing a layer of pulp capping agent on the affected dentin. The cements used for pulp-capping should also ensure good anti-microbial properties. The present study was carried out to detect the antimicrobial efficacy of the commonly used cements by culturing the samples directly from DDC.

Aims

To determine the efficacy of dental cements in the growth inhibition of microorganisms involved in DDC using direct contact anaerobic culture test.

Method

100 samples of DDC were collected in RTF. Ten microliters of the specimen containing RTF was incubated in thioglycolate broth consisting of 1 mm3 cement blocks of GIC, CaOH2, ZnOE and MTA anaerobically for 24 hours. This was further sub-cultured using selective media for streptococcus mutans, lactobacillus and bifidobacterium. Growth inhibition was measured by calculating the number of CFUs and statistically analysed using ANOVA and Tukey's post-hoc tests.

Results

Tests showed variation in the anti-microbial effects of the cements and was highly significant at P < 0.001. Bifidobacterium showed most number of CFUs. MTA was the most effective pulp capping agent exhibiting 87.13% reduction in microbial growth, followed closely by ZnOE (84.6%).

Conclusion

A conservative approach to treat DDC is the need of the hour which calls for the use of pulp capping cements of good antimicrobial efficacy. The current study revealed bifidobacterium to be the most prevalent in DDC and the cement that would best inhibit the mixed culture growth was MTA followed closely by ZnOE.

Peripheral adenomatoid odontogenic tumour

The Adenomatoid Odontogenic Tumour (AOT) is more than 100 years old, known by different names and the term AOT was coined in 1969 by Philipsen and Birn. AOT frequently occurs in intra-osseous location in gnathic skeleton and rarely seen in peripheral forms. These are rare odontogenic tumours, accounting for 2.2--7.1% of all odontogenic tumours, whereas the central or intraosseous variant of AOT in follicular and extra-follicular presentation, accounts for 95.6% of all AOTs. The peripheral variant presents as a gingival mass, which may cause slight saucerization of alveolar bone or might not affect the bone at all. These peripheral variants constitute 4.4% or less, of all AOTs of the gnathic skeleton. Here, we present a rare case of a peripheral variant of AOT in a 35-years-old female, 1.5 to 2 cm in dimension seen on the labial gingiva in right canine-premolar area. The lesion showed marked bone loss in 13 and 14 teeth region, causing mobility of 13. Histopathology showed a well encapsulated tumour mass with metaplastic bone in the capsule. A conventional AOT with ductal and rosette pattern was seen with tumour droplets and amyloid like material. The case clinically presented a moderately aggressive behaviour.

Polymorphous Adenocarcinoma: High-Grade Transformation With Immunohistochemical Workup

Intraoral tumours associated with mucosa are commonly oral squamous cell carcinomas followed by minor salivary gland carcinomas, the commonest being mucoepidermoid carcinoma, adenoid cystic carcinoma, and polymorphous adenocarcinoma (PAC). PAC is the second most common malignant tumour that is found in the minor salivary glands of the oral cavity and rarely exhibits high-grade transformation (HGT). We report a case of a 50-year-old woman with a tumour on her buccal mucosa for six months. Histopathologically, the tumour showed more than 15 histopathological patterns with areas of HGT. The high-grade transformed areas predominantly showed solid patterns, increased mitosis, necrosis, vascular invasion, and perineural invasion. An immunohistochemical (IHC) panel inclusive of p63, SOX-10, S-100, calponin, vimentin, and Ki-67 was done to evaluate the tumour and grade PAC. The Ki-67 index was around 25%-30%, confirming the diagnosis of PAC-HGT. This might be the first case of primary PAC-HGT seen on the buccal mucosa on initial clinical presentation.

Clear cell adenomatoid odontogenic tumour and dentigerous cyst: an uncommon hybrid combination - case and review

Odontogenic tumours and cysts have a characteristic presentation, histopathologically and clinically. The diagnostic criteria and nomenclature are distinct as elaborated in 2017 WHO classification. But one can occasionally and infrequently find an association between different odontogenic tumours and cysts, like calcifying epithelial odontogenic tumour (CEOT) and adenomatoid odontogenic tumour (AOT), CEOT and ghost cell tumour. Some of the odontogenic tumours and cysts share the site of occurrence, intraosseous location, teeth involved/quadrant involved and histopathology too. Hence these lesions are considered for differential diagnoses in most cases. But some instances report hybrid or associated tumours and cyst cases. Here we present a case of dentigerous cyst in association with AOT that showed variation in cell type, pattern and induction pattern.

Involvement of husband in maternal and child health care in rural field practice area of a tertiary medical college in South India-A mixed method study

Background:

To commemorate the 25^th anniversary of International Conference on Population and Development (ICPD) in the pursuit of Sexual and Reproductive Health Rights views of duty bearers (men) who are mostly not involved in antenatal care in a patriarchal society like India needs to be explored.

Design:

It is a mixed method study (Triangulation).

Setting and Population:

It was conducted in a rural field practice area of a private medical college in South India covering a population of 19,200.

Objectives:

1) To determine the involvement of husband in maternal and child care. 2) To find out the perceptions of the husbands of antenatal pregnant women in maternal and child health (MCH) care.

Methods:

(Quan) A semi-structured questionnaire to find out the areas where husband is involved maximum during antenatal care (Qual). In-depth interviews was conducted to find out the factors associated with their involvement.

Results:

About 72.5% came for antenatal visits while it decreased to 27.5% during labor and further decreased to 20.3% during immunization. The reasons for decreased participation were (1) Professional Commitments, (2) Views of a Patriarchal society like India, (3) Financial Difficulties, and (4) Health Facility Related Challenges.

Conclusion:

There is a need to educate the husband regarding the importance of husband's involvement during delivery and immunization. Programs should also include men as the stakeholders for accountability and better MCH care for women.

Case of labial sclerosing polycystic adenoma with ductal carcinoma in situ (DCIS)

Minor salivary gland tumours are enigmatic in their behaviour and presentations. Histopathological diagnosis of these tumours encompasses a large spectrum. Conventionally, small nodular tumours of the upper lip or the labial mucosa are generally adenomas, frequently pleomorphic adenomas. Here, we describe a case of a solitary nodular tumour, occurring in the upper labial mucosa, diagnosed as sclerosing polycystic adenoma (SPA) with intraductal epithelial proliferation of high grade. This is a rare lesion, which has entered into the category of salivary gland tumours recently in the 2017 WHO categorisation. We report a case of paucicystic SPA with intraductal epithelial proliferations in the labial minor salivary gland of a 56-year-old woman, which might be the first report of a case occurring in the upper labial mucosa.

Grading of Oral Leukoplakia: Can It be Improvised Using Immunohistochemical Markers p63 and CD31

Introduction

Oral squamous cell carcinoma is usually preceded by potentially malignant disorders (PMDs), the most common being oral leukoplakia. A conservative management protocol is followed for milder dysplastic cases, while severe dysplastic lesions are surgically excised. Several classification systems have been developed based mainly on histopathological features with a lot of inter-observer variations. The present study was done to assess the use of immunohistochemical (IHC) markers in grading leukoplakic lesions in addition to histopathological grading.

Aims and Objectives

To grade leukoplakia using different grading systems and assess if IHC markers can aid in categorizing leukoplakia.

Materials and Methods

Thirty-five cases of leukoplakia were graded using Ljubljana, 2005 World Health Organization (WHO), and Binary System followed by IHC staining with p63 and CD31.

Results and Statistics

Variation was noted in 12 cases while using WHO, 11 using Ljubljana, and 7 using Binary System and was significant on Cohen-Kappa statistics, with the least significant variation noted on Binary System. p63 staining assisted to group doubtful cases and even identify variation in cases graded positively on histopathology. In total, 17 cases stained one-third (mild/low), while 15 cases stained one-half or more (higher grade) epithelial thickness. A weak correlation was observed between all grading systems and p63 on Kendall's Tau-b analysis and the weak correlation was significant for the WHO and binary grading systems. Analyzing p63 and CD31 using Kruskal-Wallis test, an increase in mean vessel density (MVD) was noted for mild/moderate cases but decreased for severe cases.

Conclusion

Addressing histological categorization of PMDs assisted by IHC markers to understand the biological behavior of the tissues is currently essential with studies on more markers to assist in the management protocol.

Optimal diagnostic tool for surveillance of oesophageal varices during COVID-19 pandemic

AIM

To study the diagnostic accuracy and utility of triphasic abdominal computed tomography (CT) in the diagnosis and grading of oesophageal varices (OVs) as an alternative to endoscopy during the COVID-19 pandemic.

MATERIALS AND METHODS

A prospective analysis was undertaken of retrospective data from cirrhotic patients who underwent oesophago-gastro-duodenoscopy (OGD) and a triphasic abdominal CT from January to December 2019. Endoscopists and radiologists provided their respective independent assessment of OV grading after being blinded to the clinical details. Performance of CT grading of OVs was compared with the reference standard endoscopic grading using weighted kappa (k). Non-invasive scores such, as aspartate transaminase (AST)-to-platelet ratio index (APRI), Fibrosis-4 (FIB-4) Index, platelet: spleen (PS) ratio were correlated between the two techniques.

RESULTS

OV grading between endoscopists and radiologists showed 81.73% agreement (85 out of 104 patients) in the comparative analysis of 104 cirrhotic patients, of which no varices (57.1%, n=4), small (85.1%, n=23), medium (72.2%%, n=26), and large varices (94.1%, n=32) with a weighted k score of 0.88 (95% confidence interval 0.82-0.94). Overall, the sensitivity of CT in the diagnosis of no, small, medium, and large OVs was 66.6%, 79.3%, 89.6%, and 94.1%, respectively, with an area under the receiver operating curve (AUROC) score of 0.775, 0.887, 0.839, and 0.914. Performance of APRI, FIB-4, and PS ratio correlated well with the severity of OVs with no difference between OGD and CT grading.

CONCLUSION

Triphasic abdominal CT can be an invaluable tool in the diagnosis and grading of OVs during the COVID-19 pandemic.

Well-armed is well started: A population-based study to assess risk stratification in potentially premalignant oral epithelial lesions

BACKGROUND

The association between potentially premalignant oral epithelial lesions (PPOEL), oral squamous cell carcinoma and its higher incidence in South-East Asian population due to the use of arecanut, pan, slaked lime and tobacco is well known. The study was carried out in urban and rural population of Bengaluru, Karnataka, to assess and correlate the pattern of habit, clinical presentation and cytological grading of PPOELs, attempting at identifying the main arms associated with risk of malignant transformation.

AIMS

Assessment of history, clinical presentation of PPOELs, co-relate with cytological grades and escalate to binary risk assessment.

MATERIALS AND METHODS

One hundred and fourteen cytological smears received at the Department from screening camps were stained with Papanicolaou and hematoxylin-eosin stains and correlated with the clinical data.

RESULTS/STATISTICS

Descriptive and inferential statistics were performed. 38% lie between 21 and 30 years, 76.3% males, 81 cases involved buccal mucosa with 51.1% Grade II cytosmear, 53.5% chewing tobacco habit, 10 cases involved multiple sites with 60% Grade II cytosmear and 6 cases showed Grade III cytosmear. Based on clinical risk factors and cytological grading, 15.3% were grouped under high risk lesions as against 5.4% when only cytological grading was considered.

CONCLUSION

The incidence of PPOELs is increasing in young males with chewing tobacco mainly in buccal mucosa associated with habit. Biopsy and definitive treatment is necessary when the lesions are red, nonhomogeneous, seen in multiple sites and concomitant lesions with higher grades of dysplasia. The use of cytosmears in screening camps helps to assess, affirm and stress on biopsy on higher dysplasia grades as biopsy is not an acceptable norm in camps.

Assessment of the most reliable sites in mandibular bone for the best deoxyribonucleic acid yield for expeditive human identification in forensics

Background:

In recent years, the techniques used to identify human remains post accidents, trauma or in case of criminal investigation have been expanded, improved and rendered more complex by the emergence of technologies based on deoxyribonucleic acid (DNA) analysis. In the head and neck area, tooth has been proven to be the best quantitative source for DNA but in certain cases where the mandible specimen is edentulous or the tooth is extensively destroyed with caries, large dental restorations, mobile, or if they show any perimortem or postmortem fractures, sampling of such tooth specimen is usually avoided. In such situations, bone is considered the next best site for DNA analysis. Mandible being the largest, strongest and dense cortical bone is the most prominent facial bone that can be easily disarticulated. It can be analyzed for the best short tandem repeat (STR) segment qualitative amplification using polymerase chain reaction (PCR) technique for forensic analysis which can be used for gender and age determination.

Aim:

The aim of this study is to determine the best site for optimum quantitative and qualitative yield of DNA for amplification using specific and standard STR segment by conventional PCR technique.

Methodology:

Fifteen mandibular samples exposed to different environmental conditions were collected. Bone pieces of 1 cm × 1 cm were cut from each mandible from three sites, i.e., the ramus, angle and body, wherein the genomic DNA was isolated and was subjected to PCR using restricted number of 25 cycles.

Results:

The STR segment D3S1358 from clone RP11-438F9 used for the study showed very good amplification in restricted number of PCR cycles in the ramus region with number of repeats in every 15^th genomic region.

Conclusion:

This study highlights the use of mandibular bone for the expeditive human identification. As per the study, the ramus of the mandible gave high quantitative and qualitative yield of DNA with thick amplification band of the STR segment as compared to the body and angle of the mandible. Thus ramus of the mandible can be preferred over other sites for molecular forensic investigations.

Periosteal desmoid tumour: a rare finding in the oral cavity

A 55-year-old female patient reported with an intraoral well-localised asymptomatic swelling on the right side of the mandible in relation to the right mandibular first molar along with a history of trauma 6 months back. Panoramic radiograph revealed normal trabecular bone pattern in relation to the lesion. The lesion was excised along with the associated buccal cortical plate and tooth. The microscopic examination revealed a well-circumscribed lesion consisting of spindle cells arranged in storiform pattern associated with the buccal cortical plate. The key feature to note was presence of reactive periosteum, which was in continuum with the lesion. Immunohistochemistry (IHC) revealed faint nuclear positivity for β-catenin. The above findings led to our diagnosis of periosteal desmoid, which is rarely reported in the head-and-neck region. The major challenge in the diagnosis of such lesions is good clinicopathological correlation as the differential diagnosis of spindle-cell lesions is vast and needs IHC confirmation.

Bulk synthesis of multi-walled carbon nanotubes by AC arc discharge method

This work proposes the production of multi-walled carbon nanotubes by AC arc discharging of spectroscopically pure graphite electrodes of different shapes, that is, movable cylindrical and stationary rectangular electrode by manual metal arc welding setup. Continuous arc was generated by maintaining the gap of about 3 mm between the electrodes which in turn formed the plasma zone. Vaporization of carbon cations followed by sudden quenching paved the way for formation of carbon nantotubes. Nanotubes produced were deposited on the stationary graphite electrode in the form of soot. Further extraction of the nanoparticles from the soot was performed by conducting series of purification processes which will be discussed in upcoming chapters. Morphology and purity of the extracted nanotubes were investigated by X-ray diffraction, scanning electron microscopy, field-emission scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. Following the characterization process, it was observed that the so-produced nanotubes were of different shapes, that is, carbon cone nanotubes, nanocapsules, nanoparticles and branching type and randomly oriented. The length of the nanotubes varied from 231 to 561 nm, whereas diameter was found to be in the range of 14–55 nm.

Ameloblastic Fibrodentinoma: A Case with Varied Patterns of Dysplastic Dentin

Ameloblastic fibrodentinoma is a benign odontogenic tumor belonging to the category of "odontogenic epithelium with odontogenic ectomesenchyme" along with recognition of induction in the form of dentin in atypical or dysplastic forms. The biological behaviour of ameloblastic fibrodentinoma is not very different from ameloblastic fibroma; hence, it is treated similarly by conservative procedures. It is important to understand the histopathogenesis of these rare tumors. Though rare, they are an independent entity awaiting recognition. Here, we report a case of amelobalstic fibrodentinoma in a 14-year-old female patient.

Familial Cancers of Head and Neck Region

Cancers that occur in families more often than would be expected by chance are termed as familial cancers. They occur due to an inherited genetic mutation and account for 5%-10% of all cancers. This review article presents some of the common Familial Cancer Syndromes (FCS) such as MEN 2B, hyperparathyroidism-jaw tumour syndrome, familial oral squamous cell carcinoma, melanoma, nasopharyngeal carcinoma, paraganglioma, neurofibroma and other syndromes associated with head and neck region.

A relationship between CD4 count and oral manifestations of human immunodeficiency virus-infected patients on highly active antiretroviral therapy in urban population

Introduction:

Human immunodeficiency virus (HIV) infection gradually destroys the body's immune system, which makes it harder for the body to fight infections. HIV infection causes a quantitative and qualitative depletion of CD4 lymphocyte count, which increases the risk of opportunistic infections. Thus, CD4 count is one of the key factors in determining both the urgency of highly active antiretroviral therapy (HAART) initiation and the need of prophylaxis for opportunistic infections.

Aim:

This study aims to evaluate the prevalence and variations in the oral manifestations of HIV/acquired immune deficiency syndrome patients on HAART therapy in urban population and their association with CD4 count.

Materials and Methods:

A study was conducted by screening eighty patients who were HIV positive in an urban location. Both adult and pediatric patients were screened for oral manifestations and simultaneously CD4 count was also evaluated. Patients with HIV infection for variable time period who are under HAART were considered.

Statistical Analysis:

Measures of central tendency were used to analyse the data.

Results:

HIV infection destroys the immune system of an individual, making the patient susceptible to various infections and malignancies. With the advent of antiretroviral therapy, the scenario has changed drastically. We have observed that patients with CD4 counts between 164 and 1286 show relatively few oral manifestations. Long-term HAART therapy causes pigmentation, xerostomia and angular cheilitis but is taken up quite well by the patients.

Conclusion:

In this study, eighty patients with HAART from urban population showed very minimal oral findings because of good accessibility for treatment and awareness about HIV infections. The patients who were on long-standing HAART treatment also showed minimal oral manifestation such as pigmentation and xerostomia. Hence, we conclude that recognition, significance and treatment of these lesions in patients with HIV infection do not require elaborate setup and can be treated with basic primary health care.

Molecular Classification of Oral Squamous Cell Carcinoma

Oral Squamous Cell Carcinoma (OSCC) is the commonest tumour in the oro-facial region with increasing incidence in the recent years. The disease is challenging as it still depicts a high morbidity and mortality rate. Clinico-pathological data, tumour site, pathologic site tumor, lymphnode, metastasis (TNM) staging, histological grade, invasion, perineural invasion and metastasis have been evaluated to a great depth in relation to OSCC. Co-morbidity factors like use of tobacco, alcohol consumption and various other factors including genetic predisposition have been looked at for finding a suitable treatment protocol. The crux of the matter in understanding the complexity of oral cancer lies in the biological heterogeneity of the tumour. Similar heterogeneity is seen in clinical presentation, histopathology and molecular changes at the cellular level. In spite of the disease being diagnosed, a prediction of the same related to behaviour has remained elusive. Hence, it is time to look beyond at the genetic and epigenetic events leading to molecular and cytogenetic changes that elucidate the pathogenesis and help in design and implementation of targeted drug therapy. A molecular classification of OSCC needs to be put in place much before a clinician can design the treatment protocol of the same and predict the prognosis.

Papilliferous Keratoameloblastoma of the Mandible - A Rare Case Report

Ameloblastomas are common odontogenic tumours that are benign and locally aggressive. Histopathologically, the tumor exhibits significant diversity with common and rare variants. Here, we report an unusual variant of a common odontogenic tumour in the mandibular posterior region on the right side in a 44-year old male patient. This is the sixth case of Papilliferous Keratoameloblastoma (PKA) to be reported in the English literature till date. More case reports are vital to determine the clinical, radiological, histopathological and behavioural aspects of this extremely rare histological type of ameloblastoma. This tumour awaits re-inclusion as a distinct entity in the future classifications of the WHO Classification of head and neck tumours upon further case accrual.

Fallacious Carcinoma- Spindle Cell Variant of Squamous Cell Carcinoma

Spindle cell carcinoma is a unique, rare and peculiar biphasic tumour of head and neck which is not frequently observed in the oral cavity. This variant of squamous cell carcinoma although of monophasic epithelial origin, simulates a sarcoma and is an aggressive carcinoma with high frequency of recurrence and metastasis. A correct and timely diagnosis is of paramount importance. Most of the tumours require an Immunohistochemistry (IHC) panel for confirmation or diagnosis. We report a case of spindle cell carcinoma with varied histopathological morphology and clinical presentation in a middle aged female with a brief review of literature.

Extravasation injuries

OBJECTIVES

To evaluate the time and type of treatment following extravasation from intravenous infusion and the sequelae of the injuries.

METHOD

The charts of 12 patients who were referred to the Plastic and Orthopaedic Services at the University Hospital of the West Indies were reviewed. The study period was between May 2003 and January 2007. Data were collected on age, gender, site of extravasation, extravasated agent, treatment of the extravasation, necrosis interval, duration of hospital stay for treatment of injury and whether the intravenous line was resited and at what site in relation to the injury.

RESULTS

The age of patients ranged from three days to 67 years. The female-to-male ratio was 2:1. In five patients, the intravenous infusion was discontinued immediately after the swelling was noticed. In two patients, the intravenous infusion was stopped after seven hours and in five patients it was discontinued within 12 to 22 hours. The necrosis interval ranged from 12 hours to three weeks. Immediate treatment following extravasation and discontinuation of the infusion included limb elevation in three patients and application of cold compresses in one patient. Eleven patients developed skin necrosis of varying severities. There was no skin necrosis in one patient. Ten patients spent an average of 31 extra days in hospital for treatment of the extravasation injury. Two patients were treated in an out-patient clinic.

CONCLUSIONS

Extravenous leaks can cause severe tissue injuries. Morbidity is increased by delay in recognition and treatment of the extravasation. A protocol for the treatment of extravasation is recommended.

Salmonella paratyphi osteomyelitis and psoas abscess

Bone and joint infections associated with Salmonella spp account for less than 1% of all Salmonella infections. Most of the isolates are Salmonella typhi. Joint infections with S. paratyphi are uncommon, and there have been only a few reported cases in literature. Psoas abscess caused by S. paratyphi has not been reported previously in the literature. We report a case of S. paratyphi A osteomyelitis and psoas abscess.

Reconstructive microsurgery: reviewing the past, anticipating the future

This article gives an overview of reconstructive microsurgery It is written for residents and fellows training in plastic and microsurgery and practitioners who are intimately involved in the clinical practice of complex reconstructions. The authors describe the highlights of the history of microsurgery and relevant clinical principles. The final portion of this article is designed to elucidate some of the tremendous advances in limb transplantation and the future directions of microsurgery.

Management of hepatic cysts by percutaneous drainage and instillation of tetracycline hydrochloride

This paper reports two cases of benign hepatic cysts successfully treated by the instillation of tetracycline hydrochloride. The patients presented with solitary large symptomatic hepatic cysts and underwent ultrasound guided needle aspiration followed by the instillation of tetracycline hydrochloride. The cyst size diminished without complication and the patients have remained symptom free. We review the treatment of this uncommon entity and propose that injection of tetracycline hydrochloride is an effective nonoperative treatment of symptomatic solitary hepatic cysts.

The neuronal repressor REST/NRSF is an essential regulator in medulloblastoma cells

Medulloblastoma is the most malignant pediatric brain tumor. It is believed to originate from the undifferentiated external granule layer cells in the cerebellum, but the mechanism of tumorigenesis remains unknown. Here we studied three types of human medulloblastoma cells that express markers corresponding to different levels of neuronal differentiation. They expressed the neuronal repressor element 1 (RE1) silencing transcription factor/neuron-restrictive silencer factor (REST/NRSF; refs. 7-10) at very high levels compared with either neuronal progenitor NTera2 (NT2) cells or fully differentiated human neuron teratocarcinoma (hNT cells). To counter the effect of REST/NRSF, we used a recombinant transcription factor, REST-VP16, constructed by replacing repressor domains of REST/NRSF with the activation domain of viral protein (VP16). Transient expression of REST-VP16 in medulloblastoma cells was able to compete with the endogenous REST/NRSF for DNA binding and stimulate neuronal promoters. High-efficiency expression of REST-VP16 mediated by adenovirus vectors (Ad.REST-VP16) in medulloblastoma cells was able to counter REST/NRSF-mediated repression of neuronal promoters, stimulate expression of endogenous neuronal genes and trigger apoptosis through the activation of caspase cascades. Furthermore, intratumoral injection of Ad.REST-VP16 in established medulloblastoma tumors in nude mice inhibited their growth. Therefore, REST/NRSF may serve as a new target for therapeutic interventions for medulloblastoma through agents such as REST-VP16.

Automated extraction and variability analysis of sulcal neuroanatomy

Systematic mapping of the variability in cortical sulcal anatomy is an area of increasing interest which presents numerous methodological challenges. To address these issues, we have implemented sulcal extraction and assisted labeling (SEAL) to automatically extract the two-dimensional (2-D) surface ribbons that represent the median axis of cerebral sulci and to neuroanatomically label these entities. To encode the extracted three-dimensional (3-D) cortical sulcal schematic topography (CSST) we define a relational graph structure composed of two main features: vertices (representing sulci) and arcs (representing the relationships between sulci). Vertices contain a parametric representation of the surface ribbon buried within the sulcus. Points on this surface are expressed in stereotaxic coordinates (i.e., with respect to a standardized brain coordinate system). For each of these vertices, we store length, depth, and orientation as well as anatomical attributes (e.g., hemisphere, lobe, sulcus type, etc.). Each arc stores the 3-D location of the junction between sulci as well as a list of its connecting sulci. Sulcal labeling is performed semiautomatically by selecting a sulcal entity in the CSST and selecting from a menu of candidate sulcus names. In order to help the user in the labeling task, the menu is restricted to the most likely candidates by using priors for the expected sulcal spatial distribution. These priors, i.e., sulcal probabilistic maps, were created from the spatial distribution of 34 sulci traced manually on 36 different subjects. Given these spatial probability maps, the user is provided with the likelihood that the selected entity belongs to a particular sulcus. The cortical structure representation obtained by SEAL is suitable to extract statistical information about both the spatial and the structural composition of the cerebral cortical topography. This methodology allows for the iterative construction of a successively more complete statistical models of the cerebral topography containing spatial distributions of the most important structures, their morphometrics, and their structural components.

Nrf2 and Nrf1 in association with Jun proteins regulate antioxidant response element-mediated expression and coordinated induction of genes encoding detoxifying enzymes

Antioxidant response element (ARE)-mediated expression and coordinated induction of genes encoding detoxifying enzymes is one mechanism of critical importance to cellular protection against oxidative stress. In the present report, we demonstrate that nuclear transcription factors Nrf2 and Nrf1 associate with Jun (c-Jun, Jun-B and Jun-D) proteins to upregulate ARE-mediated expression and coordinated induction of detoxifying enzymes in response to antioxidants and xenobiotics. Nrf-Jun association/heterodimerization and binding to the ARE required unknown cytosolic factor(s). Nrf2 containing one mutated leucine in its leucine zipper region was more efficient in upregulation of ARE-mediated gene expression, as compared to Nrf1 with two mutated leucines.

Caffeic acid phenethyl ester stimulates human antioxidant response element-mediated expression of the NAD(P)H:quinone oxidoreductase (NQO1) gene

Caffeic acid phenethyl ester (CAPE) is a phenolic antioxidant derived from the propolis of honeybee hives. CAPE was shown to inhibit the formation of intracellular hydrogen peroxide and oxidized bases in DNA of 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated HeLa cells and was also found to induce a redox change that correlated with differential growth effects in transformed cells but not the nontumorigenic parental ones. Mediated via the electrophile or human antioxidant response element (hARE), induction of the expression of NAD(P)H quinone oxidoreductase (NQO1) and glutathione S-transferase Ya subunit genes by certain phenolic antioxidants has been correlated with the chemopreventive properties of these agents. Here, we determined by Northern analysis that CAPE treatment of hepatoma cells stimulates NQO1 gene expression in cultured human hepatoma cells (HepG2), and we characterized the effects of CAPE treatment on the expression of a reporter gene either containing or lacking the hARE or carrying a mutant version of this element in rodent hepatoma (Hepa-1) transfectants. A dose-dependent transactivation of human hARE-mediated chloramphenicol acetyltransferase (cat) gene expression was observed upon treatments of the Hepa-1 transfectants with TPA, a known inducer, as well as with CAPE. The combined treatments resulted in an apparent additive stimulation of the reporter expression. To learn whether this activation of cat gene expression was effected by protein kinase C in CAPE-treated cells, a comparison was made of cat gene activity after addition of calphostin, a protein kinase C inhibitor. Calphostin reduced the cat gene induction by TPA but not by CAPE, suggesting that stimulation of gene expression in this system by these agents proceeds via distinct mechanisms. Band-shift experiments to examine binding of transactivator proteins from nuclear extracts of treated and untreated cells to a hARE DNA probe showed that TPA exposure increased the binding level. In contrast, binding of factors to this probe was inhibited after either in vivo treatment of cells with CAPE or in vitro addition of this compound to the nuclear extract. In view of the clear stimulation by CAPE of gene expression mediated by hARE, possible explanations of this result are discussed.

Nrf1 and Nrf2 positively and c-Fos and Fra1 negatively regulate the human antioxidant response element-mediated expression of NAD(P)H:quinone oxidoreductase1 gene

Twenty-four base pairs of the human antioxidant response element (hARE) are required for high basal transcription of the NAD(P)H:quinone oxidoreductase1 (NQO1) gene and its induction in response to xenobiotics and antioxidants. hARE is a unique cis-element that contains one perfect and one imperfect AP1 element arranged as inverse repeats separated by 3 bp, followed by a "GC" box. We report here that Jun, Fos, Fra, and Nrf nuclear transcription factors bind to the hARE. Overexpression of cDNA derived combinations of the nuclear proteins Jun and Fos or Jun and Fra1 repressed hARE-mediated chloramphenicol acetyltransferase (CAT) gene expression in transfected human hepatoblastoma (Hep-G2) cells. Further experiments suggested that this repression was due to overexpression of c-Fos and Fra1, but not due to Jun proteins. The Jun (c-Jun, Jun-B, and Jun-D) proteins in all the possible combinations were more or less ineffective in repression or upregulation of hARE-mediated gene expression. Interestingly, overexpression of Nrf1 and Nrf2 individually in Hep-G2 and monkey kidney (COS1) cells significantly increased CAT gene expression from reporter plasmid hARE-thymidine kinase-CAT in transfected cells that were inducible by beta-naphthoflavone and teri-butyl hydroquinone. These results indicated that hARE-mediated expression of the NQO1 gene and its induction by xenobiotics and antioxidants are mediated by Nrf1 and Nrf2. The hARE-mediated basal expression, however, is repressed by overexpression of c-Fos and Fra1.