Management of Poorly Differentiated Thyroid Cancer and Differentiated High-Grade Thyroid Carcinoma.

Thyroid carcinoma of follicular cell origin exists on a histopathologic and clinical spectrum. The authors focus on the category of tumors that fall between the very favorable well-differentiated thyroid carcinomas and the very unfavorable anaplastic thyroid carcinomas. These intermediately aggressive tumors include poorly differentiated thyroid carcinoma and the newly defined differentiated high-grade thyroid carcinoma. Both diagnoses require certain histopathologic requirements be met in order to accurately identify these tumors post-operatively. Management remains primarily surgical though adjunctive treatments such as molecular targeted therapies (eg, tyrosine kinase inhibitors) and differentiation therapy (to restore tumor response to radioactive iodine) are also becoming available.

Evaluation of Orthodontic Mini-implant-anchored en masse Retraction of Maxillary Anterior Teeth with Reduced Bone Support: A Prospective Finite Element Analysis Study.

AIM: The purpose of this study was to evaluate force systems to bring about the en masse retraction of maxillary anterior teeth having reduced bone levels using finite element analysis. MATERIALS AND METHODS: This is a prospective study. Three-dimensional finite element models of maxillary dentition having normal alveolar bone level and 2, 4, and 6 mm bone loss with first premolar extraction were constructed from a spiral CT scan of a skull. Archwire and brackets were modeled on the facial surfaces of teeth. Retraction force of 175 gm was applied from an orthodontic mini-implant placed bilaterally between the second premolar and first molar and 12 mm above plane of the archwire to anterior retraction hook (ARH) fixed at two heights of 6 and 10 mm above the archwire. RESULTS: Maximum displacement and periodontal ligament (PDL) stress were calculated for different combinations of bone levels and ARH. As the bone loss increased, the tipping tendency, amount of intrusion, and maximum von Mises stress in PDL also increased, showing a direct correlation. CONCLUSION: To minimize tipping and PDL stress, the height of ARH should be increased in alveolar bone loss conditions to allow retraction force to pass through or even above the center of resistance of anterior teeth. Even then, pure bodily retraction may not be achieved, but tipping tendency can be reduced. Nevertheless, it may not be suitable to increase ARH beyond a limit owing to chances of irritation to the vestibular mucosa. Alternative methods should be contemplated to reduce the tipping behavior. CLINICAL SIGNIFICANCE: The alternative is to apply a lighter retraction force to reduce lingual tipping. A higher counter-moment in the archwire or bracket can also be incorporated.

Preoperative and Operative Risk Factors for Conversion of Laparoscopic Cholecystectomy to Open Cholecystectomy in Pakistan.

Introduction The currently available literature suggests a wide range of conversion (4.9-20%) from laparoscopic cholecystectomy (LC) to open cholecystectomy (OC) despite the increase in surgical expertise. Open cholecystectomy is important as the last resort for safe surgical practice in complicated cases. Increased number of pre-operative and perioperative risk factors need to be identified to pre-empt conversion. However, there has been a significant decrease in conversion rates over the past few decades. This study was conducted to determine conversion rates in our population and to identify any significant risks for conversion. Methods This prospective study was conducted at the Shifa International Hospital, Islamabad, Pakistan, including 1081 cholecystectomies, performed over a two-year period from January 2017 to January 2019. Comparison of risk factors between the two groups; laparoscopic cholecystectomy (LC) group and conversion to open cholecystectomy (OC) group was done. Statistical analysis was done using SPSS 24.0.1. P<0.05 were considered significant. Results In our study, the overall conversion rate was 7.78%. Factors of conversion to open cholecystectomy (OC) included age ≥65, morbid obesity, diabetes mellitus, and previous abdominal surgery. Deranged alkaline phosphatase (ALP), increased total bilirubin, increased common bile duct (CBD) diameter, and multiple stones in ultrasonography showed a statistically significant association with the conversion. Per-operative findings of increased adhesions >50%, empyema gallbladder (GB), perforated GB, and scleroatrophic GB showed a higher risk of conversion too (p <0.05). However, there was no statistical association with preoperative endoscopic retrograde cholangiopancreatography (ERCP) to OC in our population. Conclusion An open cholecystectomy is a safe approach for patients with complicated gallbladder disease. No doubt laparoscopic cholecystectomy is the gold standard having its outstanding benefits. This study identifies predictors of choice for OC in addition to the decision to convert to OC. In view of the raised morbidity and mortality associated with open cholecystectomy, distinguishing these predictors will serve to decrease the rate of OC and to address these factors preoperatively.

Amelogenesis imperfecta - lifelong management. Restorative management of the adult patient.

The biggest challenge restorative dentists face in rehabilitating patients with amelogenesis imperfecta (AI) is trying to restore aesthetics, function and occlusal stability while keeping the treatment as conservative as possible. The goals of treatment should be to prolong the life of the patient's own teeth and avoid or delay the need for extractions and subsequent replacement with conventional fixed, removable or implant retained prostheses. In order to achieve these goals a stepwise approach to treatment planning is required starting with the most conservative but aesthetically acceptable treatment. This article discusses the management of AI and presents the various treatment options available for restoring the adult patient who presents to the dentist with AI.

Association of a Monopartite Begomovirus Producing Subgenomic DNA and a Distinct DNA Beta on Croton bonplandianus Showing Yellow Vein Symptoms in Pakistan.

The recent discovery that monopartite begomoviruses on ageratum and cotton essentially require a DNA satellite called DNA ß (2,4) is leading to identification of several other hosts that have similar disease complexes. A weed species (Croton bonplandianus) belonging to the family Euphorbiaceae is one such example. C. bonplandianus is widely distributed on wastelands throughout the Punjab Province in Pakistan. It very often shows yellow vein symptoms indicating infection by a begomovirus. To detect a begomovirus, both symptomatic and asymptomatic plants were collected from several widely separated locations in the Punjab Province. Total DNA was isolated from these samples by the cetyltrimethylammoniumbromide (CTAB) method, resolved in an agarose gel, and blotted on a nylon membrane (2). A full-length clone of DNA A of Cotton leaf curl virus (CLCuV) labeled with 32PdCTP was used as a probe in Southern hybridization (2). The probe detected hybridizing bands only in symptomatic plants, confirming the presence of a begomovirus. In addition to hybridizing bands of the expected sizes, smaller bands were also detected, suggesting the presence of subgenomic molecules derived from DNA A. Universal polymerase chain reaction (PCR) primers for dicot-infecting geminiviruses (1) were used in PCR for amplification of DNA A of the begomovirus associated with the disease. The use of these primers in PCR was expected to result in amplification of full-length DNA A. In addition to a product of the expected size (2.7 to 2.8 kb), another product of approximately 1.4 kb was amplified. The presence of subgenomic DNAs that are derived from DNA A is an indicator of the monopartite nature of begomoviruses, because in bipartite begomoviruses subgenomic DNAs are derived solely from DNA B. The presence of a DNA ß, a DNA satellite associated with certain monopartite begomoviruses, was suspected because of symptoms and the possible monopartite nature of the virus. Universal primers for amplification of DNA ß (3) were used in PCR for amplification of a putative DNA ß. The PCR reaction yielded a product of expected size (≈1.4 kb). A probe from the amplified product was made by the oligolabeling method. The probe detected hybridizing bands in all symptomatic samples collected from three locations, confirming the association of a DNA ß with the disease. A duplicate blot when hybridized with a DNA ß associated with ageratum yellow vein disease did not hybridize to these samples. These results confirm that yellow vein disease on this weed is associated with a monopartite begomovirus and a distinct DNA ß. References: (1) R. W. Briddon et al. Mol. Biotechnol. 1:202, 1994. (2) R. W. Briddon et al. Virology 285:234, 2001. (3) R. W. Briddon et al. Mol. Biotechnol. In press. (4) K. Saunders et al. Proc. Natl. Acad. Sci. U S A 97:6890, 2000.

First Report of Tan Spot on Wheat in Pakistan.

Tan spot is caused by Pyrenophora tritici-repentis and is an economically important foliar disease of wheat worldwide. The fungus produces two types of symptoms, necrosis and chlorosis, on susceptible wheat cultivars. Isolates have been grouped into five races based on their ability to induce necrosis (nec+) and chlorosis (chl+) on appropriate wheat differentials (1,2). During March 2000, foliar diseases of wheat were surveyed in major wheat-growing areas of the Punjab Province of Pakistan. Tan spot was observed at 13 locations in the province. Diseased leaf samples were collected from all 13 locations to satisfy Koch's postulates. Isolations were made by placing 2-cm-long diseased leaf pieces in petri dishes with three layers of dampened Whatman No. 1 filter paper. The leaf pieces were incubated under an alternating cycle of 24 h of light at 21°C and 24 h of dark at 16°C. A fungus that produced erect, single dark yellow-brown conidiophores with single light yellow-brown conidia was recovered from all the samples and identified as Drechslera tritici-repentis, the anamorph of Pyrenophora tritici-repentis. Single spores were transferred on V8 potato dextrose agar for further study. Seven single spore isolates recovered from the samples were imported through APHIS and tested for pathogenicity and race structure in a growth chamber at North Dakota State University. Two-week-old seedlings of wheat differentials were inoculated individually with a spore suspension of each isolate, and consistent results were found in four replicated experiments. Four of seven isolates were identified as race 1 (nec+chl+), whereas, three isolates did not correspond to any of the currently identified five races. For all these isolates, one of the differentials (Katepwa), which exhibits necrosis, chlorosis, or neither symptom to the five described races, showed both necrosis and chlorosis. This is the first report of the occurrence of tan spot of wheat in Pakistan. The widespread presence of tan spot in the region is a potential threat to wheat production. References: (1) De Wolf et al. Can. J. Plant Pathol. 20:349, 1998. (2). Lamari et al. Can. J. Plant Pathol. 17:312, 1995.