Glucose modulation of cell size in yeast.

Saccharomyces cerevisiae cells grown in glucose have larger average size than cells grown in ethanol. Besides, yeast must reach a carbon source-modulated critical cell size in order to enter S phase at Start. This control is of outmost physiological relevance, since it allows us to coordinate cell growth with cell cycle progression and it is responsible for cell size homeostasis. The cell sizer mechanism requires the overcoming of two sequential thresholds, involving Cln3 and Far1, and Clb5,6 and Sic1, respectively. When both thresholds are non-functional, carbon source modulation of cell size at Start is completely abolished. Since inactivation of extracellular glucose sensing through deletion of either the GPR1 or the GPA2 gene causes a marked, but partial, reduction in the ability to modulate cell size and protein content at Start, it is proposed that both extracellular and intracellular glucose signalling is required for properly setting the cell sizer in glucose media.

First Report of Phakopsora pachyrhizi, the Causal Organism of Soybean Rust in the Province of Misiones, Argentina.

In April 2002, Phakopsora pachyrhizi Sydow was observed for the first time in L. N. Alem, in the Province of Misiones, Argentina. Misiones is nearly surrounded by Paraguay and Brazil, where P. pachyrhizi was discovered recently (2) and where it is a serious disease (3). Symptoms were observed on leaves in the upper half of plants at the R6 stage in a soybean research field trial. Symptoms included reddish-brown lesions on leaves especially on the abaxial surface, and uredinias were observed in the lesions with a 10× lens. Leaf defoliation was observed due to the disease after the R5 stage, and the enviroment (high humidity and air temperatures) was particularly conducive to the disease. The field trial area was 2,500 m2 and included soybean genotypes of maturity groups V to IX. Symptoms were detected in the later maturity groups. Field trials were surrounded by kudzu (Pueraria sp.), which is a common weed introduced in South America as a forage plant by Asian farmers, and it was reported as the main host of this pathogen in Paraguay (2). To confirm the identity of the pathogen, leaf samples from the middle part of plants were collected and sent to the Foreign Disease-Weed Science Research Unit, Ft. Detrick, MD. Samples were analyzed using a real-time polymerase chain reaction assay (1). Identification of P. pachyrhizi was confirmed the last week of May, 2002 (R. Frederick, personal communication). The soybean production area in Misiones is a small area in Argentina lying 600 km northeast of the main soybean area in the north central part of the country. SENASA (Servicio Nacional de Sanidad Vegetal [Nacional Service of Plant Health]) and SAGPYA (Secretary of Agriculture) were formally informed about these results on June 19, 2002. A program to assess the risk of disease spread is under development. References: (1) R. D. Frederick et al. Phytopathology 92:217, 2002. (2) W. Morel Paiva. AnaisII Congresso Brasilero de Soja e Mercosoja. Foz de Iguazu, Brazil, 2002. (3) T. Yorinori. Anais II Congresso Brasilero de Soja e Mercosoja. Foz de Iguazu, Brazil, 2002.

Laparoscopy in pancreatic and hepatobiliary cancer.

Laparoscopic techniques can be used for diagnosis, staging, and therapeutic procedures, both palliative or curative. Laparoscopy needs to be used in the context of algorithms of evaluation and management that consider the natural history and biology of the diseases at stake, concepts of evidence-based decisions, cost-effectiveness, quality of life, expertise available, and the philosophy of involved institutions. Accurate staging facilitates the selection of patients for resection, for neoadjuvant therapy, and selective planning for best palliation. The therapeutic role of advanced laparoscopic or laparoscopic assisted procedures is likely to increase (biliary bypass, gastro-jejunostomy, liver resections, cryosurgery, radiofrequency ablation, etc.). The place of laparoscopy in staging and treatment, however, has to be critically and continuously reviewed in the context of new developments in diagnostic imaging techniques, endoscopic procedures, and advances in oncology.

Management of hilar cholangiocarcinoma: comparison of an American and a Japanese experience.

OBJECTIVE: To compare the experience and outcome in the management of hilar cholangiocarcinoma at one American and one Japanese medical center. SUMMARY BACKGROUND DATA: Controversies surround the issues of extent of resection for hilar cholangiocarcinoma and whether the histopathology of such cancers are similar between patients treated in America and in Japan. METHODS: Records were reviewed of 100 patients treated between 1980 and 1995 at the Lahey Clinic in the United States, and of 155 patients treated between 1977 and 1995 at Nagoya University Hospital in Japan. Selected pathologic slides of resected cancers were exchanged between the two institutions and reviewed for diagnostic concordance. RESULTS: In the Lahey cohort, there were 25 resections, 53 cases of surgical exploration with biliary bypass or intubation, and 22 cases of percutaneous transhepatic biliary drainage or endoscopic biliary drainage without surgery. In the Nagoya cohort, the respective figures were 122, 10, and 23. The overall 5-year survival rate of all patients treated (surgical and nonsurgical) during the study periods was 7% in the Lahey cohort and 16% in the Nagoya cohort. The overall 10-year survival rates were 0% and 12%, respectively. In patients who underwent resection with negative margins, the 5- and 10-year survival rates were 43% and 0% for the Lahey cohort and 25% and 18% for the Nagoya cohort. The surgical death rate for patients undergoing resection was 4% for Lahey patients and 8% for Nagoya patients. Of the patients who underwent resection, en bloc caudate lobectomy was performed in 8% of the Lahey patients and 89% of the Nagoya patients. Histopathologic examination of resected cancers showed that the Nagoya patients had a higher stage of disease than the Lahey patients. CONCLUSIONS: In both Lahey and Nagoya patients, survival was most favorable when resection of hilar cholangiocarcinoma was accomplished with margin-negative resections. Combined bile duct and liver resection with caudate lobectomy contributed to a higher margin-negative resection rate in the Nagoya cohort.

Thyroid cancer.

The management of patients with thyroid cancer can be optimized by developing multidisciplinary groups of highly specialized individuals. The completeness of surgery and its morbidity are mostly surgeon-dependent. Similarly, the decisions regarding selection of adjuvant treatments, doses, follow-up schemes, and so forth require depth of knowledge and understanding of the disease; its variables; factors that govern its course; and the values, limitations, and side effects of alternative therapies.

Hepatic malignancies.

The battle against malignancies of the liver is far from over, although tremendous strides have been made in the past decade, such as improved diagnostic capabilities, safe surgical resection, availability of safe nonsurgical ablative modalities, multimodality therapy, and aggressive approach to recurrent disease. Even after the best attempts at curative treatment, recurrence of primary and secondary malignancies of the liver continues to be the cause of demise for more than 70% of treated patients. The battle continues in the laboratories, where investigations are focused on delineating the pathophysiology of cancer on the molecular and genetic levels and mapping the patterns of cancer emergence and spread. The new millennium holds promise for formulating therapies that may improve disease-free survival for patients with malignancies of the liver.

Multidisciplinary considerations for patients with cancer of the pancreas or biliary tract.

The past century has been nearly all of the growth in knowledge about the anatomy and pathophysiology associated with cancers of the pancreas and surrounding biliary structures. Through advances in imaging technology, endoscopic practice, improvement in surgical technique and perioperative care, anesthesia advances, and a better appreciation for the usefulness of adjuvant chemotherapy and radiation therapy, physicians can offer patients some hope for long-term survival and a better quality of life when they are faced with these devastating tumors. Although surgical intervention is the "last best hope" for these patients, advances in the nonoperative disciplines will be required for substantial further improvement in patient outcomes.

Options and strategies for the management of choledocholithiasis.

The introduction of laparoscopic techniques for the management of biliary stone disease has expanded the therapeutic choices for surgeons confronted with choledocholithiasis. As new strategies emerge, the treatment of cholelithiasis and choledocholithiasis remains controversial. This paper discusses the options available for the treatment of common bile duct stones. Diagnostic and therapeutic algorithms are proposed. The treatment of these patients must be individualized, taking into consideration the condition of the patient, associated diseases, secondary complications of the gallstones, and the surgical expertise and resources of the institution.

The acute abdomen. An overview and algorithms.

The diagnosis and management of the patient with an acute abdomen remains one of the most difficult challenges for the surgeon. A thorough understanding of the anatomy and physiology of the abdomen are essential to properly generate a differential diagnosis and to formulate a treatment plan. While recent advances in technology can be extremely helpful in certain situations, they cannot replace a physician's clinical judgment based upon a good history and physical examination. This article provides a general overview of the evaluation of the patient with an acute abdomen. It will also suggest algorithms to consider in the diagnosis and treatment of these patients.

Gastroduodenal polyps in familial adenomatous polyposis.

BACKGROUND: Malignant degeneration of gastroduodenal polyps has been noted in patients with familial adenomatous polyposis. To evaluate this problem further, patients with familial adenomatous polyposis were contacted and offered upper gastrointestinal tract endoscopy. METHODS: A prospective endoscopic examination was performed in 42 patients. RESULTS: The median age of patients at endoscopy was 35 years. The duration of known familial adenomatous polyposis at the time of endoscopy was 8 years. Polyps were visualized in 21 patients (50%). Gastric polyps were seen in 14 patients (33%), duodenal polyps were seen in 11 patients (26%), and ampullary polyps were seen in 7 patients (17%). Nine patients (43%) had polyps in more than one site. Adenomatous change was noted in 73% of duodenal lesions and in only 14% of gastric polyps. Surgical intervention was required in four patients; one patient had an early ampullary carcinoma, and three patients had severe dysplasia involving the duodenum or ampulla. All four patients had undergone a previous screening examination, results of which were normal in three patients. Compared with other patients, these four patients were older (median age, 58 years; p = 0.02) and had a longer duration of disease (median duration, 25 years; p = 0.002). CONCLUSIONS: All patients with familial adenomatous polyposis require lifelong endoscopic surveillance to detect malignant degeneration, which may appear later in life.

Long-term results of pylorus-preserving pancreatoduodenectomy for chronic pancreatitis.

OBJECTIVE: To assess the long-term outcome of patients following pylorus-preserving pancreatoduodenectomy (PPPD) for chronic pancreatitis. DESIGN: Retrospective study with mean follow-up of 63 months (range, 1 month to 13.7 years). SETTING: Tertiary referral hospital. PATIENTS: Records of all patients who underwent PPPD for chronic pancreatitis at Lahey Clinic were reviewed. All patients who were alive were contacted by telephone. In cases where patients had died, information was gathered from family members and hospital records. RESULTS: Forty-five patients underwent PPPD for disabling chronic pancreatitis. The mean preoperative duration of pain was 50 months, with 32 patients (70%) requiring daily narcotics. In one patient resection of the portal vein was required. One patient died within 30 days of the operation. Forty-one patients (92%) had improvement of pain at 5 years. The mean pain score (on a scale of 0 to 10) was 9.2 preoperatively and 1.5, 0.8, 1.1, and 1.1 at 6 months, 1 year, 2 years, and 5 years, respectively. Thirty-three patients (74%) had a postoperative weight gain to an average of 92% of their pre-illness weight. New-onset diabetes occurred in six patients (14%) by 6 months and in 21 patients (46%) by 5 years. Hypoglycemia was the cause of death in one patient who underwent total pancreatectomy. Four patients died of causes unrelated to PPPD. Marginal ulcers occurred in five patients (10%). Nine patients required late operations. CONCLUSIONS: In selected patients, resection of the head of the pancreas achieves long-term pain improvement in over 90% of cases. The early development of diabetes mellitus is infrequent, but over longer follow-up periods it reaches prevalence rates similar to those described in patients who have not undergone resection. Weight gain in this group was superior to that previously reported for our patients who underwent "standard Whipple" operation for chronic pancreatitis.

Malignant obstructive jaundice. Evaluation and management.

A large number of laboratory tests, radiologic studies, and endoscopic techniques are available for the evaluation of the jaundiced patient. Similarly, the therapeutic options have increased with the development and improvement of endoscopic, percutaneous, and laparoscopic procedures, and the morbidity and mortality rates associated with open surgery have decreased. The challenge is to select, on an individual basis, the most efficient and cost-effective evaluation as well as the management with the lowest morbidity and mortality rates and the best short- and long-term goals.

Biliary tract complications of laparoscopic cholecystectomy are detected more frequently with routine intraoperative cholangiography.

Controversy over whether intraoperative cholangiography (IOC) should be done routinely has intensified since the advent of laparoscopic cholecystectomy (LC). As yet, no study has demonstrated a clear benefit to its use, although their have been suggestions in the literature that routine use may confer an advantage to detection of injuries. One-hundred seventy-seven biliary tract complications occurring secondary to LC were identified from the combined data of seven institutions. The goal of this retrospective study was to examine the impact of IOC on the occurrence, recognition, and correction of such complications. The complications identified include 39 cystic duct leaks, 69 major ductal leaks or strictures, and 69 major ductal transection or excision injuries. Whether IOC was performed was known in 157 (88%) patients with 53 patients definitely having and 104 not having an IOC. Data concerning IOC were unavailable in 20 cases. More injuries were detected intraoperatively in the group having IOC (P < 0.001). Conversion of the LC to a laparotomy, often for repair of the injury, occurred more commonly in the group having a correctly interpreted IOC (P < 0.001). Conversion resulted in detection of injuries sooner, resulting in fewer operative procedures to correct the injury (P < 0.001). A transecting injury was prevented in at least seven patients when no visualization of the proximal biliary tree was documented by IOC. These partial ductal incisions were treated by t-tube placement. Incorrect interpretation of the IOC occurred in at least eight patients, with no identification of the proximal biliary tree in six.(ABSTRACT TRUNCATED AT 250 WORDS)

Occult well differentiated thyroid carcinoma presenting as cervical node disease.

Records of 92 patients with differentiated thyroid carcinoma presenting as cervical adenopathy without a palpable mass were reviewed to identify prognostic factors and to evaluate therapy. Patients were treated between 1940 and 1990 and were observed for 3 to 48 years (median 18 years). Follow-up data were obtained by chart review, correspondence, and telephone contact. Among the group, 20 patients had unilateral and 72 bilateral thyroid lobectomy, with node dissection in 77. Thyroid hormone was used in 50 patients and radioactive iodine in 20. Patients were younger than the overall population of patients with differentiated thyroid carcinoma, with more men and more multifocal thyroid disease. Risk group defined by age and sex was the most important determinant of survival. All women 50 years of age or younger and all men 40 or younger (low risk group) survived independent of the type of initial operation or use of thyroid-stimulating hormone suppression or radioactive iodine. Of the low-risk patients, 16% had recurrent disease but were treated successfully with surgery or radioactive iodine; 28% of the older patients (high risk) died of disease. A trend for better survival was noted in high risk patients undergoing bilateral thyroidectomy and in patients receiving thyroid suppression. Of the high risk patients, 26% had recurrent disease, with a 71% mortality rate. Age and sex are the primary determinants of survival. Therapy should be based on risk factors. Low risk patients should have conservative thyroid surgery and modified or limited node dissection.(ABSTRACT TRUNCATED AT 250 WORDS)

Plicatura diafragmática en la parálisis frénica unilateral luego de cirugía cardíaca / Diaphragmatic plication in phrenic nerve paralysis ter cardiac surgery

Presentamos cinco niños con parálisis unilateral permanente luego de operaciones por cardiopatías congénitas. Cuatro de ellos fueron tratados con plicatura diafragmática y uno con kinesioterapia. En dos niños menores de 3 meses la plicatura diafragmática precoz permitió acortar la asistencia ventilatoria. En dos niños mayores se realizó la plicatura del diafragma en el momento de la corrección de la cardiopatía, con desaparición posterior de los síntomas respiratorios. La plicatura diafragmática precoz en lactantes ofrece excelentes resultados. En niños mayores, aunque la parálisis frénica es bien tolerada, la plicatura hace desaparecer completamente los síntomas respiratorios

Plicatura diafragmática en la parálisis frénica unilateral luego de cirugía cardíaca / Diaphragmatic plication in phrenic nerve paralysis ter cardiac surgery

Presentamos cinco niños con parálisis unilateral permanente luego de operaciones por cardiopatías congénitas. Cuatro de ellos fueron tratados con plicatura diafragmática y uno con kinesioterapia. En dos niños menores de 3 meses la plicatura diafragmática precoz permitió acortar la asistencia ventilatoria. En dos niños mayores se realizó la plicatura del diafragma en el momento de la corrección de la cardiopatía, con desaparición posterior de los síntomas respiratorios. La plicatura diafragmática precoz en lactantes ofrece excelentes resultados. En niños mayores, aunque la parálisis frénica es bien tolerada, la plicatura hace desaparecer completamente los síntomas respiratorios