Ilstrup, Duane M.

ABSTRACT The COBAS AMPLICOR system has played a major role in the transition of molecular diagnostics from research to routine clinical laboratory use by automating the nucleic acid amplification and detection processes. However, sample preparation remains a labor-intensive portion of the procedure. In this study, we evaluated the performance of the COBAS AMPLICOR Hepatitis C Virus Test, version 2.0 (Roche Molecular Systems, Branchburg, N.J.) following manual hepatitis C virus (HCV) RNA extraction versus automated extraction with the MagNA Pure LC instrument (Roche Applied Science, Indianapolis, Ind.). Parallel replicate testing was performed with standard dilutions of 100, 75, 60, and 0 HCV IU/ml and 153 clinical specimens. An analytical sensitivity of 75 IU/ml was achieved with either the manual or the standard-volume (200 μl) automated extraction methodologies (25 of 26 [96.2%]; 95% confidence interval [95% CI], 80.4 to 99.9), whereas the clinical sensitivity and specificity were both 100% with either extraction method. A large-volume (1 ml) automated extraction method was also evaluated with standard dilutions of 40, 25, 10, and 0 IU/ml and the same 153 clinical specimens. The analytical sensitivity of the COBAS AMPLICOR assay with the large-volume extraction method was 25 HCV IU/ml (26 of 26 [100%]; 95% CI, 86.8 to 100), whereas the clinical sensitivity and specificity were both 100%. The MagNA Pure LC instrument is a versatile, labor-saving platform capable of integration with minimal modification of the existing assay procedure. The increased sensitivity of the COBAS AMPLICOR Hepatitis C Virus Test, version 2.0 performed in conjunction with large-volume HCV RNA extraction may be important in HCV diagnostic testing as new therapeutic strategies evolve.

AbstractThis prospective randomized study examined the acute‐phase response and wound healing, comparing laparoscopic (LA) and open posterior (PA) adrenalectomy in a cushingoid porcine model. Repository corticotropin gel was given to 40 pigs for 21 days. Biochemical and tissue parameters of Cushing syndrome were confirmed. The pigs were randomized to undergo LA or PA. In addition to operating time and morbidity, the acute‐phase response was compared by measuring the postoperative white blood cell count, fasting glucose, C‐reactive protein, and nitrogen balance. Wound healing was assessed by (1) scored (1–4) gross appearance at 48 hours and 1 and 2 weeks; (2) histologic examination; and (3) tensile strength. There was no difference in operating time (mean ± SD) (36 ± 9 minutes open vs. 37 ± 7 minutes laparoscopic), perioperative mortality, degree of leukocytosis, fasting glucose, or C‐reactive protein (p > 0.05). Nitrogen balance, wound scores, and tensile strength at 24 hours and 1 week were more favorable in the LA group than in the PA group (p < 0.05). In the cushingoid porcine model, laparoscopic adrenalectomy was less catabolic and was associated with fewer wound complications than the open posterior adrenalectomy. These findings provide support for continued pursuit of laparoscopic methods for adrenalectomy in the clinical setting.

AbstractWe currently recommend excision of adrenal incidentalomas ≥ 4 cm in size and all hormonally active tumors. The optimal management and follow‐up of smaller nonfunctioning tumors are controversial. The aim of this study was to determine the clinical outcome of a well defined population of patients with incidentalomas followed without operative intervention. The study group comprised 231 patients, identified from the records of abdominal or thoracic computed tomographic (CT) scans performed between 1985 and 1989. The primary outcome variable analyzed was survival. Follow‐up was obtained by office records, telephone contact, or letter. There were 101 male and 130 female patients with a mean age at diagnosis of 64 years (range 5–86 years). Most adrenal tumors were unilateral (right 113; left 98); 20 were bilateral. Mean tumor size was 2 cm (range 1–6 cm). In nine (4%) patients the tumor was ≥ 4 cm. Follow‐up [mean 7 years; range 1 month (patient died) to 11.7 years] was complete in 224 (97%) patients. Ninety‐one (39%) patients had one or more additional CT scans performed during the follow‐up period, with only four patients demonstrating a > 1 cm increase in the size of the adrenal mass. Surgical excision of these four lesions identified benign pathology. Eighty‐one (35%) patients died of conditions unrelated to adrenal pathology. No patient developed subsequent adrenal hyperfunction or adrenal malignancy. Within the context of our guidelines, conservative management of adrenal incidentalomas considered benign or nonfunctioning at diagnosis is appropriate. Additional information provided by repeat CT scanning appears to confer limited benefit. This study does not support laparoscopic removal of small, nonfunctional adrenal tumors, as has been suggested.

AbstractEighty‐two children and adolescents (18 males, 64 females; median age 14 years) surgically treated for Graves’ disease at a single institution between 1979 and 1993 were retrospectively reviewed. Most of the patients (74%) coming to thyroidectomy had been treated medically for a period ranging from 2 to 80 (median 15) months. Bilateral subtotal thyroid resection was the most frequently performed procedure (86%). Postoperatively, no permanent recurrent laryngeal nerve palsy or permanent hypocalcemia occurred. Operative mortality was zero. With a median follow‐up of 8.3 years, recurrent hyperthyroidism occurred in five patients (6%), one of whom required reoperation. Most children and adolescents with Graves’ disease can be rendered euthyroid by nonsurgical treatment options. However, prolonged and ineffective medical treatment should be avoided in these patients who are in the formative years of their lives. Surgical treatment, when indicated and employed, offers young patients with Graves’ disease a safe, rapid, definitive, cost‐effective treatment with a high success rate.

AbstractSurgical treatment for adrenal disease may be withheld from elderly patients because of concern about prohibitive operative morbidity and mortality. To obtain objective data in our practice, we analyzed the results of adrenalectomy for patients aged 65 years and older. From 1984 to 1993 there were 85 patients (41 men, 44 women) with ages ranging from 65 to 84 years (median 69 years) who underwent adrenalectomy for Cushing syndrome (n= 19), pheochromocytoma (n= 16), adrenocortical carcinoma (n= 7), benign adenoma (n= 26), or primary hyperaldosteronism (n= 17) at our institution. Median follow‐up was 26 months (range 1 month to 9.1 years). A retrospective review with respect to preoperative risks and postoperative morbidity and mortality was performed utilizing the American Society of Anesthesiologists (ASA) physical status classification and the modified Goldman multifactorial cardiac risk scheme. Survival was estimated by the Kaplan‐Meier methods. Operative mortality was 7% (six patients). No patients with pheochromocytoma or primary hyperaldosteronism died during the postoperative period. Patients undergoing adrenalectomy for adrenocortical carcinoma had a significantly higher operative mortality (43%) (p= 0.006). Postoperative complications developed in 19 patients (22%), and there was a reoperation rate of 6% (5 patients). Nineteen percent of patients required postoperative intensive care admission and had a median stay of 2 days (range, 1–38 days). Median hospital stay was 7 days (range 3–47 days). Seventy‐three patients (86%) remained alive at study completion. Two‐ and five‐year survivals were 86% and 84%, respectively. Goldman class II or greater was an excellent predictor of increased morbidity (p= 0.032) and mortality (p= 0.036). With the exception of adrenocortical carcinoma, adrenal surgery for elderly patients can be performed with acceptable morbidity and mortality. The Goldman multifactorial cardiac risk scheme reliably predicts postoperative outcome in this elderly group of patients.

AbstractMultiple endocrine neoplasia type I (MEN‐I) is an autosomal dominant disorder characterized by endocrinopathies involving the anterior pituitary gland, parathyroid glands, and pancreas. The long‐term prognosis for patients affected with this disorder is uncertain. To better characterize this prognosis, we performed a retrospective review of all patients with MEN‐I treated at a single institution during the period 1951–1997. A group of 233 patients served as the study population. Their records were analyzed for confirmation of diagnosis, treatments received, long‐term survival, and cause of death. Altogether, 108 eight male patients (46%) and 125 female patients (54%) were identified. At the conclusion of the study, 164 (70%) were alive and 69 (30%) were deceased, with a median follow‐up for patients alive at last contact of 13.4 years (range < 1 month to 54.3 years). The cause of death was reliably obtained in 60 patients. Of these patients, 17 (28%) died of causes related to MEN‐I, most commonly metastatic islet cell tumors (10 patients). The remaining patients died of causes unrelated to MEN‐I, most commonly coronary artery disease and nonendocrine malignancies (14% each). The overall 20‐year survival of MEN‐I patients was 64% (95% CI was 56–72%), and that of an age‐ and gender‐matched upper Midwest population was 81% (p < 0.001). Patients with MEN‐I appear to be at increased risk of premature death. Earlier diagnosis and treatment of potentially malignant pancreatic islet cell neoplasms may result in a decrease of this premature mortality.

AbstractTo evaluate long‐term survival of patients with gastrointestinal carcinoid tumors and to assess factors that may influence prognosis, 154 patients (49% females, 51% males), median age 62 years (range 12–84 years) treated at our institution during 1972–1982 have been followed long term. Tumor location included the foregut (7%), midgut (62%), and hindgut (30%). Ninety‐five percent of the patients underwent surgical or endoscopic excision of the primary tumor, with overall operative mortality and postoperative morbidity rates of 2.6% and 11%, respectively. At follow‐up, 60 patients (39%) were alive (median follow‐up 18 years; range 1–26 years). The main causes of death included carcinoid tumor burden (32%), unrelated causes (45%), other malignancy (19%), and unknown causes (4%). Observed overall 5‐ and 10‐year survivals were 69% and 53%, respectively. Survival was not related to gender or symptoms at presentation. However, age, embryologic origin, tumor size, depth of invasion, nodal status, and stage of disease proved to be of statistical significance (log‐rank). In a multivariate Cox' model, only older age (> 62 years) [P =0.001, odds ratio (OR) = 3.4) and embryologic origin (midgut versus foregut) (P = 0.045, OR = 0.45) provided independent prognostic power when death from any cause was taken as the end‐point. This study confirms that patient's age and the site of the primary tumor have prognostic significance. Carcinoid tumors are neuroendocrine tumors with a relatively good prognosis, and long‐term survival is possible despite advanced stages of disease.

ABSTRACT We evaluated two automated systems, MagNA Pure (Roche Molecular Biochemicals, Indianapolis, Ind.) and BioRobot 9604 (Qiagen, Inc., Chatsworth, Calif.) as effective replacements for the manual IsoQuick method (Orca Research, Inc., Bothell, Wash.) for extraction of herpes simplex virus (HSV) DNA from dermal and genital tract specimens prior to analysis by LightCycler PCR. Of 198 specimens (152 genital, 46 dermal), 92 (46.2%) were positive for HSV DNA by LightCycler PCR after automated extraction of specimens with either the MagNA Pure or BioRobot 9604 instrument. The manual IsoQuick method yielded HSV DNA (total n = 95) from three additional specimens that were negative by the automated method ( P = 0.25, sign test). Although the mean numbers of LightCycler PCR cycles required to reach positivity differed statistically significantly among all three of the methods of extraction, the estimated means differed by no more than 1.5 cycles ( P < 0.05). Seventy (76%) of the 92 specimens that were LightCycler PCR positive by all three extraction methods were also positive by shell vial cell culture assay. HSV DNA was detected by a lower LightCycler PCR cycle number (26.1 cycles) in specimens culture positive for the virus than in culture-negative samples (33.3 cycles) ( P < 0.0001). The manual IsoQuick and automated MagNA Pure and BioRobot 9604 methods provide standardized, reproducible extraction of HSV DNA for LightCycler PCR. The decision to implement a manual versus an automated procedure depends on factors such as costs related to the number of specimens processed rather than on the minimal differences in the technical efficiency of extraction of nucleic acids among these methods.

ABSTRACT A comparison of quantitative results expressed in hepatitis C virus (HCV) international units per milliliter, obtained from the VERSANT HCV RNA 3.0 (bDNA-3.0) assay, the QUANTIPLEX HCV RNA 2.0 (bDNA-2.0) assay, and the COBAS AMPLICOR HCV MONITOR version 2.0 (HCM-2.0) test was performed. A total of 168 patient specimens submitted to the Mayo Clinic Molecular Microbiology Laboratory for HCV quantification or HCV genotyping were studied. Of the specimens tested, 97, 88, and 79% yielded quantitative results within the dynamic range of the bDNA-3.0, bDNA-2.0, and HCM-2.0 assays, respectively. Overall, there was substantial agreement between the results generated by all three assays. A total of 15 out of 29 (52%) of the specimens determined to contain viral loads of <31,746 IU/ml by the bDNA-3.0 assay were categorized as containing viral loads within the range of 31,746 to 500,000 IU/ml by the bDNA-2.0 assay. Although substantial agreement was noted between the results generated by the bDNA-2.0 and bDNA-3.0 assays, a bias toward higher viral titer by the bDNA-2.0 assay was noted ( P = 0.001). Likewise, although substantial agreement was noted between the results generated by the HCM-2.0 and bDNA-3.0 assays, a bias toward higher viral titer by the bDNA-3.0 assay was noted ( P ≤ 0.001). The discrepancy between the HCM-2.0 and bDNA-3.0 results was more pronounced when viral loads were >500,000 IU/ml and resulted in statistically significant differences ( P ≤ 0.001) in determining whether viral loads were above or below 800,000 IU/ml of HCV RNA, the proposed threshold value for tailoring the duration of combination therapy. The expression of quantitative values in HCV international units per milliliter was a strength of both the bDNA-3.0 and HCM-2.0 assays.