Engineering an oleaginous yeast Candida tropicalis SY005 for enhanced lipid production.

Candida tropicalis has recently emerged as a valuable yeast species with respect to lipid metabolism, not only for its oleaginous characteristics but also for its ability to utilize diverse range of substrates. Hence, it can be explored as an ideal host for lipid metabolic engineering, although inadequate genetic transformation system for developing the stable transformant has limited this scope. To resolve this existing constraint, we have come up with a novel strategy of a genomic integrating system in the oleaginous strain SY005 of C. tropicalis. Employing this system, comprising of host-specific regulatable promoter, transcription terminator, and integration locus, we have first examined the expression of a reporter gene, and then ectopically expressed a transcription factor CtRAP1 encoding the repressor activator protein 1 of C. tropicalis SY005. A maximum lipid content of 0.37 g/g dry cell weight was achieved in the engineered strain upon galactose induction, leading to 60% (w/w) increase relative to the wild type strain SY005. This work demonstrates the use of a markerless integrative transformation system to promote lipid accumulation in the diploid yeast without applying nutrient stress and hampering cell growth. The findings of this study will augment the research on lipid metabolic engineering and exploit the enormous potential of C. tropicalis as an industrial lipid feedstock. Key points •A transformation system was established in oleaginous yeast Candida tropicalis SY005 •Activity of host-specific molecular elements was verified by reporter gene expression •SY005 was engineered to ectopically express a transcriptional regulator gene CtRAP1 •The engineered strain exhibited 60% increase in lipid content on galactose induction •The increase in lipid content was correlated with the induced expression of CtRAP1.

Malignant prolactinoma: a rare case report.

Pituitary carcinomas are rare adenohypophyseal tumors with cerebrospinal or extracranial metastasis. None of the histologic findings distinguish pituitary adenoma from carcinoma. We describe clinico-pathological and immunohistological features of malignant prolactinoma. The patient initially presented with a prolactin-secreting pituitary adenoma. The tumor showed aggressive clinical course presenting with repeated recurrences and eventually metastasized to multiple bones. MIB-1 and p53 labeling indices were also compared in primary adenoma, recurrent invasive adenoma and metastatic tumor.

Device closure of large atrial septal defects requiring devices > or =20 mm in small children weighing <20 kg.

OBJECTIVE: To report our experience of transcatheter closure of large atrial septal defects (ASDs) in small children. BACKGROUND: Although transcatheter closure of small and medium sized ASDs is well established, large ASDs are still mostly treated surgically. There is little data available on the transcatheter closure of large ASDs in children. METHODS: This was a retrospective study comprising 32 children weighing less than 20 kg, diagnosed with isolated large ASDs (requiring devices > or =20 mm in diameter). All of them underwent transcatheter closure using the amplatzer septal occluder (ASO). They were assessed by clinical examination by ECG and echocardiography before the procedure and also 1 day, 6 weeks, 6 months, and yearly thereafter. RESULTS: Age and weight of the patients were 4.5 +/- 1.8 years and 14.6 +/- 3.5 kg, respectively. The mean ASD diameter was 16.6 +/- 2.1 mm and balloon-stretched diameter was 22.7 +/- 2.6 mm. The mean Q(p)/Q(s) was 2.7 +/- 0.4. The median device size used was 24 mm (range 20-32 mm). The device was successfully placed in 31 patients. One patient had malpositioning of the device requiring surgical removal. Another patient developed transient atrioventricular block which recovered within 48 hr. During a mean follow-up of 26.8 +/- 21.8 months, no major complication such as cerebrovascular accident, cardiac perforation, systemic thromboembolism, atrioventricular valve regurgitation, obstruction to systemic or pulmonary veins or rhythm disturbances. CONCLUSIONS: Transcatheter closure of large ASDs in small children using the ASO is feasible and is not associated with a greater risk of significant complications.

Sildenafil for pulmonary hypertension secondary to congenital heart diseases.

OBJECTIVE: The purpose of this study was to evaluate the effects of oral Sildenafil for treatment of pulmonary hypertension secondary to congenital heart diseases. METHODS & RESULTS: Twelve patients with un-repaired congenital heart diseases resulting in significant pulmonary hypertension were enrolled in a prospective trial of oral Sildenafil treatment for 12 weeks. The outcomes measured were change in the systemic oxygen saturations, 6-minute walk test distance, and New York Heart Association class. The systemic blood pressure and visual symptoms were monitored for evaluating the tolerability of Sildenafil. The mean age was 25.7+/-14.4 years. The mean pulmonary vascular resistance before treatment was 17.4 Wood units. After 12 weeks of sildenafil, an increase in oxygen saturations (87.8+/-5.3%-90.25+/-4%, p=0.04) with an associated increase of one New York Heart Association class (p=0.009) was noted. A non-statistically significant increase in the 6-minute walk test distance (310.33+/-42-333.75+/-54.6 meters, p=0.47) was also noted. Sildenafil was well-tolerated with no significant change in systemic blood pressure or visual side-effects. CONCLUSION: Oral Sildenafil is well-tolerated and produces some improvement in the oxygenation and functional status of patients with pulmonary hypertension secondary to congenital heart diseases.

Staged repair of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries: experience with 104 patients.

OBJECTIVE: To determine the early and intermediate-term outcome of the staged repair used to treat children with pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries. METHODS: We reviewed a retrospective case series of 104 patients with this complex lesion. Information was obtained from medical records and referring physicians. RESULTS: Of the 104 patients treated with the staged repair, 58 achieved completion of anatomic repair. The 10-year mortality was 16.5%. In the patients with complete repair, the median right-to-left ventricle pressure ratio was 0.5. The overall surgical reoperation rate was 17%, and 15.5% of patients required postoperative interventional cardiac catheterization. In the multivariate analysis, the number of collateral vessels incorporated in the repair was found to be an independent risk factor for postoperative mortality and an elevated right-to-left ventricle pressure ratio after complete repair. CONCLUSION: The staged repair can be successfully used to treat patients with pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries. This method yields a relatively low mortality with good functional results.

Risk factors for persistent pleural effusions after the extracardiac Fontan procedure.

OBJECTIVE: Pleural effusions after the Fontan operation contribute significantly to morbidity and prolonged hospitalization. This study investigates the association between selected preoperative, operative, and postoperative variables and persistent pleural effusions after the extracardiac Fontan procedure. METHODS: We conducted a retrospective study of extracardiac Fontan procedures. The variables analyzed as potential risk factors included age and weight at the time of the operation, anatomic diagnosis, preoperative oxygen saturation, mean pulmonary artery pressure, ventricular end-diastolic pressure, presence of an accessory source of pulmonary blood flow, presence of significant aortopulmonary collateral vessels, presence of fenestration, cardiopulmonary bypass time, conduit size, postoperative pulmonary artery pressure, use of angiotensin-converting enzyme inhibitors, and presence of postoperative infection. The outcome measures evaluated were duration and volume of chest tube drainage after surgical intervention. RESULTS: From June 1997 to August 2002, 100 consecutive patients underwent the extracardiac Fontan procedure. The median age at operation was 3.1 years. The median duration of chest tube drainage was 10 days, and the median volume of drainage was 14.7 mL.kg(-1).d(-1). As determined by means of multivariate analysis, significant risk factors for pleural effusions lasting more than 2 weeks were lower preoperative oxygen saturation (P =.011) and the presence of postoperative infections (P =.003). Significant risk factors for pleural effusions draining at more than 20 mL.kg(-1).d(-1) were lower preoperative oxygen saturation (P =.005), smaller conduit size (P =.04), and longer duration of cardiopulmonary bypass (P =.004). CONCLUSIONS: Lower preoperative oxygen saturation, presence of postoperative infection, smaller conduit size, and longer duration of cardiopulmonary bypass were associated with persistent pleural effusions after the extracardiac Fontan procedure. Modifications of some of these risk factors might influence the duration and volume of pleural drainage after surgical intervention.

Use of assist devices and ECMO to bridge pediatric patients with cardiomyopathy to transplantation.

BACKGROUND: Pulsatile ventricular assist devices (VADs) are used to bridge adults with end-stage heart disease to transplantation. A combination of external implantable pulsatile and continuous-flow external mechanical support now can be used to bridge pediatric patients with end-stage cardiomyopathy to orthotopic heart transplantation (OHT). METHODS: We reviewed consecutive pediatric patients with cardiomyopathy (n = 28) who required mechanical cardiac support from July 1995 to February 2001. All were OHT candidates with severe hemodynamic compromise despite maximal medical support. We excluded from this series patients who had undergone cardiotomy. RESULTS: Nineteen patients received support from external continuous-flow devices, either with extracorporeal membrane oxygenation or with centrifugal VADs, and 9 patients received pulsatile support. Nineteen of 28 (68%) patients were successfully bridged to transplant (17) or weaned (2) from their devices after recovery. Of the patients successfully bridged to transplant or recovery, 89% are alive to date. Univariate analysis revealed that a lower bilirubin concentration after 2 days of support was associated with a favorable outcome (p = 0.006). As expected, the patients with pulsatile VADs had significantly higher rates of extubation and oral feeding. CONCLUSION: Pulsatile and continuous-flow devices can complement each other to significantly extend the lives of a wide range of pediatric patients with severe cardiomyopathies.

Transcatheter closure of atrial septal defects.

Transcatheter closure of atrial septal defects has evolved significantly over the last 20 years. Transcatheter closure has replaced surgical closure for the treatment of most secundum atrial septal defectsat the current time. A major reason for this is the lower morbidity of transcatheter closure procedures. Several closure devices have come into clinical use. The Amplatzer septal occluder (AGA Medical Co.) currently has the largest reported experience and subsequently the best-established safety and efficacy features. Clinically challenging situations, such as larger atrial septal defects, atrial septal defects with deficient rims and multiple atrial septal defects, are increasingly being addressed using the transcatheter approach, with improved results. The incidence of most complications has significantly reduced over time, and serious side effects are relatively uncommon. In this review, the literature is summarized regarding the current role of transcatheter closure, the evolution of the different available devices for clinical use and the complications that occur with their use. A comparison is also made with surgical closure techniques.

Pathological predictive factors for tumor response in locally advanced breast carcinomas treated with anthracyclin-based neoadjuvant chemotherapy.

AIM: Neoadjuvant chemotherapy (NACT) is used as a primary treatment for locally advanced breast carcinoma (LABC) and also extended to operable breast cancer. The aim of this study was to evaluate the predictive value of different histological parameters in core biopsy of LABC patients treated with anthracycline-based chemotherapy regimen. Pathological assessment of the excised tumor bed is the gold standard and is essential for identifying the group of patients with pathologic complete response (pCR) or pathologic noncomplete response (pNR). MATERIALS AND METHODS: A total of 50 patients with stage II and III breast carcinoma were included in the study. Pretreatment core biopsy histological features include tumor type, histological grade, presence of tumor necrosis, lymphovascular emboli (LVE) and immunohistochemical stains for estrogen receptor (ER) and progesterone receptor (PR) were obtained. Patients were given 3-6 cycles of NACT. Pathological response was assessed. RESULT: Seven out of 50 patients achieved pCR. A total of 71.4% patients who achieved pCR had tumor necrosis on initial core biopsy while only 30% pNR cases had this feature (P =0.035). Breast carcinoma other than ductal type was chemoresistant. Of 47 core biopsies, LVE was observed in 13 cases (28 %) of which 11 showed axillary node metastasis. None of these 13 cases had pCR, thus having poor predictive value. CONCLUSION: Pathological parameters like type of tumor, presence of LVE and tumor necrosis in the core biopsy can predict the response to NACT in routine stain. Tumor necrosis and type of breast carcinoma are predictive parameters for tumor responsiveness to NACT. LVE was reliable in predicting axillary lymph node metastasis.

Metastatic appendiceal goblet cell carcinoid masquerading as mucinous adenocarcinoma in effusion cytology: A diagnostic pitfall.

Goblet cell carcinoids are rare tumors of appendix having a mixed phenotype, with partial neuroendocrine differentiation and intestinal type goblet cell morphology. The reported incidence of this tumor is still limited. Till now, only two cases of metastatic goblet cell appendiceal carcinoid on effusion cytology have been reported in literature. We describe the clinico-pathological details and lay stress on fluid cytology of metastatic goblet cell carcinoid to ascitic fluid.

Osteoid differentiation in mesodermal (mullerian) adenosarcoma of ovary.

A 55-year-old female presented with abdominal pain and 10 cm mass per abdominal examination. Computerized tomography scan of abdomen and pelvis revealed a heterogeneously enhancing solid cystic mass right ovarian mass and mild ascites. Surgery was performed. Specimens were sent for examination. Microscopic examination revealed an admixture of benign but occasionally atypical appearing mullerian type glands with sarcomatous stroma. Solid area showed undifferentiated tumour cells. Atypical mitoses and necrosis were also seen. Areas with extensive benign osteoid surrounded by fibroblastic stroma were also present. Glandular component showed positivity for CK-7, AE-1 and EMA while sarcomatous areas showed positivity for vimentin only. Mullerian adenosarcoma of ovary with sarcomatous overgrowth (SO) having heterologous component was confirmed. Postoperative 3 cycles of chemotherapy was given and the patient was well till date (three months after surgery).

Primary diffuse large B-cell lymphoma of ampulla of vater: a rare case report.

INTRODUCTION: Primary lymphomas of the ampulla of Vater are extremely rare. Among these most frequent are follicular lymphomas followed by mucosa-associated lymphoid tissue-type lymphoma. CASE REPORT: We report a case of a 36-year-old female diagnosed with diffuse large B-cell lymphoma (DLBCL) of the ampulla of Vater. Endoscopic biopsy was non-diagnostic. Whipple's resection was performed. The patient was given six cycles of chemotherapy. One year later, the patient developed recurrence at the anastomotic site and again treated with combination chemotherapy. Patient is doing well after 2 years of initial surgery. DISCUSSION: Tumors of the ampulla of Vater are included in the pancreaticobiliary group of neoplasms; in some instances, it is almost impossible to ascertain the exact origin of the tumor anatomically. The patients of primary lymphoma of the ampulla of Vater may have a varied clinical presentation or may be completely asymptomatic and detected during routine medical check-ups for gastric cancer screening. CONCLUSION: We present a rare case of primary DLBCL of the periampullary region. Due to the rarity of these lesions, their ability to masquerade as periampullary carcinomas, and the fact that these tumors show a good response to chemotherapy, an early diagnosis is desirable.

Spermatocytic seminoma associated with undifferentiated sarcoma: a rare case report.

The presence of sarcomatous element transforms the usually innocuous spermatocytic seminoma into a highly aggressive neoplasm. We report a case of spermatocytic seminoma with undifferentiated sarcomatous component in a 43-year-old male, presented with testicular mass since two and a half years. Orchidectomy was performed and after 9 months, the patient presented with recurrent scrotal mass with bilateral pulmonary metastases.

Management of dysfunctional uterine bleeding based on endometrial thickness.

OBJECTIVE: To manage patients with dysfunctional uterine bleeding (DUB) according to endometrial thickness. METHODS: A retrospective chart review of 49 patients who reported 8 or more days of bleeding was performed. They were then divided into three groups based on endometrial thickness (mm): less than 6, 6-11, and greater than 11. These three groups were treated with combined oral contraceptive pills (OCP), conjugated estrogen plus progesterone and megestrol respectively. Patients given megestrol also underwent endometrial biopsy before treatment. Patients recorded the degree of bleeding each day for one month after starting treatment. RESULTS: Mean endometrial thickness in the combined OCPs, conjugated estrogen plus progesterone and megestrol groups were 4, 8 and 14 mm, respectively. Combined OCPs decreased bleeding from 46 to 8 days (P < 0.05, n = 8). Conjugated estrogen plus progesterone decreased the number of days of bleeding from a mean of 41 to 9 (P < 0.01, n = 16). Megestrol decreased bleeding from 54 to 3 days (P < 0.001, n = 25). 52% of patients given megestrol had endometrial hyperplasia. CONCLUSION: These results support the effectiveness of treating patients with DUB according to endometrial thickness.

Isolated skull base metastasis as the first manifestation of hepatocellular carcinoma--a rare case report with review of literature.

INTRODUCTION: Hepatocellular carcinoma rarely metastasizes to skull base. CASE REPORT: We report an extremely rare case of solitary skull base metastasis without metastasis to any other site, with right third, fourth, and sixth cranial nerve palsy as the initial manifestation of the disease. DISCUSSION: The biopsy specimen of skull base lytic lesion suggested metastatic hepatocellular carcinoma. Subsequent examination revealed a large mass involving superior segment of right lobe of liver, which was confirmed as hepatocellular carcinoma on histopathological examination. CONCLUSION: Until now, there have been only 24 cases of hepatocellular carcinoma metastasizing to skull base cited in literature. We report here an unusual case of solitary skull base metastasis from hepatocellular carcinoma prior to the diagnosis of primary tumor.

Spermatocytic seminoma associated with undifferentiated sarcoma: A rare case report.

The presence of sarcomatous element transforms the usually innocuous spermatocytic seminoma into a highly aggressive neoplasm. We report a case of spermatocytic seminoma with undifferentiated sarcomatous component in a 43-year-old male, presented with testicular mass since two and a half years. Orchidectomy was performed and after 9 months, the patient presented with recurrent scrotal mass with bilateral pulmonary metastases.