Supporting Acute Appendicitis Diagnosis: A Pre-Clustering-Based Classification Technique

Service quality and cost containment represent two critical challenges in healthcare management. Toward that end, acute appendicitis, a common surgical condition, is important and requires timely, accurate diagnosis. The diverse and atypical symptoms make such diagnoses difficult, thus resulting in increased morbidity and negative appendectomy. While prior research has recognized the use of classification analysis to support acute appendicitis diagnosis, the skewed distribution of the cases pertaining to positive or negative acute appendicitis has significantly constrained the effectiveness of the existing classification techniques. In this study, we develop a pre-clustering-based classification (PCC) technique to address the skewed distribution problem common to acute appendicitis diagnosis. We empirically evaluate the proposed PCC technique with 574 clinical cases of positive and negative acute appendicitis obtained from a tertiary medical center in Taiwan. Our evaluation includes tradition support vector machine, a prevalent resampling classification technique, Alvarado scoring system, and a multi-classifier committee for performance benchmark purposes. Our results show the PCC technique more effective and less biased than the benchmark techniques, without favoring the positive or negative class

Long-term follow-up of patients with surgical intractable acromegaly after linear accelerator radiosurgery

Background/PurposeRadiotherapy is a crucial treatment for acromegalic patients with growth hormone (GH)-secreting pituitary tumors. However, its effect takes time. We retrospectively reviewed the long-term outcome of linear accelerator stereotactic radiosurgery (LINAC SRS) for patients with acromegaly from the perspective of biochemical remission and associated factors.MethodsTwenty-two patients presenting with residual or recurrent (GH)-secreting functional pituitary tumor between 1994 and 2004 who received LINAC SRS were enrolled and followed up for at least 3 years. Residual or recurrent tumor was defined as persistent elevated GH or insulin-like growth factor-1 (IGF-1) level and image-confirmed tumor after previous surgical treatment. Biochemical remission was defined as fasting GH less than 2.5 ng/mL with normal sex-and-age adjusted IGF-1.ResultsThe mean follow-up period was 94.7 months (range 36–161 months). Overall mean biochemical remission time was 53 months (median 30 months). Biochemical control was achieved in 15 patients (68.2%) over the follow up period. One patient experienced recurrence after SRS and underwent another operation. Initial GH at diagnosis and pre-SRS GH correlated with biochemical control (p = 0.005 and p < 0.0001, respectively). Further evaluation demonstrated that biochemical control stabilized after 7.5 years. Overall post-SRS hormone deficit persisted in five patients (22.7%).ConclusionIn comparison to other radiosurgery modalities, LINAC radiosurgery also provides a satisfactory outcome. SRS has maximum effect over the first 2 years and stabilizes after 7.5 years. Moreover, SRS elicits long-term biochemical effects and requires longer follow-up for better biochemical remission

A pre-S gene chip to detect pre-S deletions in hepatitis B virus large surface antigen as a predictive marker for hepatoma risk in chronic hepatitis B virus carriers

<p>Abstract</p> <p>Background</p> <p>Chronic hepatitis B virus (HBV) infection is an important cause of hepatocellular carcinoma (HCC) worldwide. The pre-S₁and -S₂mutant large HBV surface antigen (LHBS), in which the pre-S₁and -S₂regions of the LHBS gene are partially deleted, are highly associated with HBV-related HCC.</p> <p>Methods</p> <p>The pre-S region of the LHBS gene in two hundred and one HBV-positive serum samples was PCR-amplified and sequenced. A pre-S oligonucleotide gene chip was developed to efficiently detect pre-S deletions in chronic HBV carriers. Twenty serum samples from chronic HBV carriers were analyzed using the chip.</p> <p>Results</p> <p>The pre-S deletion rates were relatively low (7%) in the sera of patients with acute HBV infection. They gradually increased in periods of persistent HBV infection: pre-S mutation rates were 37% in chronic HBV carriers, and as high as 60% in HCC patients. The Pre-S Gene Chip offers a highly sensitive and specific method for pre-S deletion detection and is less expensive and more efficient (turnaround time 3 days) than DNA sequencing analysis.</p> <p>Conclusion</p> <p>The pre-S_1/2mutants may emerge during the long-term persistence of the HBV genome in carriers and facilitate HCC development. Combined detection of pre-S mutations, other markers of HBV replication, and viral titers, offers a reliable predictive method for HCC risks in chronic HBV carriers.</p

Discriminating Glucose Tolerance Status by Regions of Interest of Dual-Energy X-Ray Absorptiometry: Clinical Implications of Body Fat Distribution

WSTĘP. Zbadanie, czy ocena rozmieszczenia tkanki tłuszczowej w organizmie metodą absorpcjometrii promieniowania rentgenowskiego o podwójnej energii (DEXA, dual energy X-ray absorptiometry) może być pomocny w ocenie stanu tolerancji glukozy. MATERIAŁ I METODY. U 1015 badanych mieszkańców Chin (559 mężczyzn i 456 kobiet) zastosowano doustny test obciążenia glukozą (75,0 g). Na podstawie jego wyników wyodrębniono osoby o prawidłowej (NGT, normal glucose tolerance) i upośledzonej (IGT, impaired glucose tolerance) tolerancji glukozy oraz osoby, u których rozpoznano cukrzycę (DM, diabetes mellitus). Mierzono wysokość ciśnienia tętniczego i oceniano profil lipidowy. Na podstawie stosunku obwodu talii do bioder (WHR, waist-to-hip ratio) i wyników DEXA oceniano rozmieszczenie tkanki tłuszczowej u osób w poszczególnych grupach. WYNIKI. Rozmieszczenie tkanki tłuszczowej, wyrażone poprzez WHR oraz wskaźnik centralizacji, wykazało znamienną częściową korelację ze stężeniem hemoglobiny glikowanej, wysokością ciśnienia tętniczego i profilem lipidowym u wszystkich badanych. Po skorygowaniu wyników wobec wieku i wskaźnika masy ciała (BMI, body mass index), stwierdzono znamienne różnice częstości wszystkich sercowo-naczyniowych czynników ryzyka w poszczególnych grupach, z wyjątkiem stężenia cholesterolu całkowitego. W grupie DM odnotowano znamiennie wyż-sze wartości WHR i wskaźnika centralizacji przy niższej procentowo zawartości tkanki tłuszczowej w udach. Ponadto, pacjentów z grupy IGT charakteryzował wyższy wskaźnik centralizacji niż osoby z grupy NGT. Nie stwierdzono jednakże znamiennych różnic masy tkanek beztłuszczowych w porównywanych grupach. Po dokonaniu wieloczynnikowej analizy logistycznej regresji wskaźnik centralizacji pozostał istotnym czynnikiem umożliwiającym ocenę tolerancji glukozy, niezależnie od procentowej zawartości tkanki tłuszczowej w organizmie. WNIOSKI. Otyłość centralna wykazuje znamienną korelację z sercowo-naczyniowymi czynnikami ryzyka w grupach osób o różnej tolerancji glukozy. Indeks centralizacji, oceniany metodą DEXA, wydaje się lepszym wskaźnikiem upośledzenia tolerancji glukozy niż WHR, otyłość brzuszna czy uogólniona otyłość (wyrażone odpowiednio jako odsetek zawartości tłuszczu całkowitego lub BMI) w dużej grupie badanych Chińczyków.OBJECTIVE. To determine whether measuring body fat distribution by dual-energy X-ray a bsor ptio metry (DEXA) can be used to discriminate glucose tolerance status. RESEARCH DESIGN AND METHODS. Using a 75-g oral glucose tolerance test, a total of 1,015 Chinese subjects (559 men and 456 women) were categorized as having normal glucose tolerance (NGT), impaired glucose tolerance (IGT), or diabetes. Blood pre ssure and lipid profiles of these subjects were measured. Waist-to-hip ratio (WHR) and DEXA were used to evaluate the varying patterns of body fat distribution among the gro ups. RESULTS. Body fat distribution, as reflected by WHR and the centrality index, showed significant partial correlation coefficients with glycosylated hemoglobin, blood pressure, and lipid profiles in all subjects. After adjusting for age and BMI, there were significant differences among the three glycemic groups for all the cardiovascular risk factors except for total cholesterol level. The diabetic group had a significantly higher WHR and centrality index, but lower femoral fat percentage than the NGT and IGT groups. The diabetic group also showed higher abdominal fat percentage than the NGT group. More over, the IGT group had a higher centrality index than the NGT group. However, no significant differences were found in the percentage of lean tissue mass among the three groups. Using multiple stepwise logistic regression models, the centrality index remained a significant factor for discriminating different glucose tolerance status independent of the percentage total body fat. CONCLUSIONS. Central obesity has shown significant correlation with cardio vascular risk factors among the three different glycemic groups. Centrality index measured by DEXA appears to be the better predictor of glucose intolerance, compared with WHR, abdominal fat, and general obesity (reflected by percentage total body fat or BMI) in a large cohort of the Chinese population