Fabrication of nanocolumns for liquid chromatography

This paper shows that in situ micromachining can be used to simultaneously position and define (i) support particles, (ii) convective transport channels, (iii) an inlet distribution network of channels, and (iv) outlet channels in multiple chromatography columns on a single quartz wafer to the level of a few tenths of a micrometer. Stationary phases were bonded to 5 x 5 x 10 microns collocated monolith support structures separated by rectangular channels 1.5 microns wide and 10 microns deep with a low degree of deviation of channel width between the top and bottom of channels. High aspect ratio microfabrication can only be achieved with deep reactive ion etching. The volume of a 150 microns x 4.5 cm column was 18 nL. Column efficiency was evaluated in the capillary electrochromatography (CEC) mode using rhodamine 123 and a hydrocarbon stationary phase. Plate heights in these columns were typically 0.6 micron in the nonretained and 1.3 microns in the retained modes of operation. Columns were designed to have identical mobile-phase velocity in all channels in an effort to minimize outgassing during operation. When the total lateral cross-sectional area of channels at all points along the separation axis is identical, linear velocity of the mobile phase in a CEC column should be the same. Columns were operated at atmospheric pressure.

Phase I study of the orally administered butyrate prodrug, tributyrin, in patients with solid tumors

Butyrates have been studied as cancer differentiation agents in vitro and as a treatment for hemoglobinopathies. Tributyrin, a triglyceride with butyrate molecules esterified at the 1, 2, and 3 positions, induces differentiation and/or growth inhibition of a number of cell lines in vitro. When given p.o. to rodents, tributyrin produces substantial plasma butyrate concentrations. We treated 13 patients with escalating doses of tributyrin from 50 to 400 mg/kg/day. Doses were administered p.o. after an overnight fast, once daily for 3 weeks, followed by a 1-week rest. Intrapatient dose escalation occurred after two courses without toxicity greater than grade 2. The time course of butyrate in plasma was assessed on days 1 and 15 and after any dose escalation. Grade 3 toxicities consisted of nausea, vomiting, and myalgia. Grades 1 and 2 toxicities included diarrhea, headache, abdominal cramping, nausea, anemia, constipation, azotemia, lightheadedness, fatigue, rash, alopecia, odor, dysphoria, and clumsiness. There was no consistent increase in hemoglobin F with tributyrin treatment. Peak plasma butyrate concentrations occurred between 0.25 and 3 h after dose, increased with dose, and ranged from 0 to 0.45 mM. Peak concentrations did not increase in three patients who had dose escalation. Butyrate pharmacokinetics were not different on days 1 and 15. Because peak plasma concentrations near those effective in vitro (0.5-1 mM) were achieved, but butyrate disappeared from plasma by 5 h after dose, we are now pursuing dose escalation with dosing three times daily, beginning at a dose of 450 mg/kg/day.

Use of spiral and non-spiral computed tomography arterial portography in the detection of potentially malignant liver masses

The present study assesses the usefulness of computed tomography (CT) arterial portography (CTAP) in detecting and defining the number and anatomy of potentially malignant liver lesions. One hundred and one adults studied in 1993 and 1994 were retrospectively reviewed, including patients with primary or secondary tumours for possible resection and patients with non-hepatic malignancies in whom the detection of liver metastases would preclude surgery. Twenty-three patients underwent non-spiral CT studies and 78 had studies on a spiral unit, with 22 of these having single phase and 56 having dual phase studies to overcome artefact problems. The relationship between lesion size and detection sensitivity is critical. On non-spiral studies, the overall lesion detection sensitivity and positive predictive value was 69 and 90%, respectively. Detection sensitivity was 100 and 20% for lesions > 1 cm and < 1 cm, respectively. On single phase spiral CTAP the overall detection sensitivity and positive predictive value was 80 and 66%, respectively. Detection sensitivity for lesions > 1 cm and < 1 cm was 100 and 0%, respectively. On dual phase spiral CTAP the overall detection sensitivity and positive predictive value was 76 and 71%, respectively. For lesions > 1 cm and < 1 cm the sensitivity was 81 and 55%, respectively. Eighteen patients with non-hepatic malignancies with unsuspected metastatic spread did not proceed to major surgery because of liver metastases detected on CTAP. Perfusion artefacts occurred in 30 and 64% of non-spiral and of initial portal venous spiral CTAP studies, respectively. By using the double-phase technique, these artefacts were substantially diminished. In conclusion, CTAP is a valuable tool for assessing the presence, site and size of possible liver tumours and confers a benefit even when previous ultrasound and conventional CT have already been used. In addition, CTAP has a lower limit of useful resolution of approximately 1 cm. Perfusion artefacts can be reduced by a dual phase protocol.

Intercostal pedicle flap for thoracic oesophageal perforations

Oesophageal perforations are associated with a high mortality and morbidity. Intrathoracic perforations especially are associated with mediastinitis and sepsis. The repair of these perforations may be difficult, particularly when there has been a delay to diagnosis. We report our use of a method to repair or buttress the suture line after repair with a vascularized intercostal muscle flap, having used it successfully in two patients with intrathoracic oesophageal perforations.

A phase-I study of cpt-11, weekly bolus 5-fu and leucovorin in patients with metastatic cancer

CPT-11 is a topoisomerase I inhibitor with activity against colorectal cancer. This study was designed to explore the potential for combining CPT-11 with fluorouracil and leucovorin. 5-FU (500 mg/m(2)) and leucovorin (500 mg/m(2)) were administered for 4 consecutive weeks and CPT-11 was given on weeks 1 and 4 of each 6 week cycle. The starting dose of CPT-11 was 25 mg/m(2) and the dosage was escalated by increments of 25 mg/m(2) in cohorts of 3 patients. Nine patients were treated on study. Grade 4 diarrhea was the dose limiting toxicity at 50 mg/m(2). Alternative strategies to combine CPT-11 with 5-FU and leucovorin are being explored.

Cold agglutinins: preoperative diagnosis leads to an uneventful perfusion

This report presents the successful use of normothermic cardiopulmonary bypass (CPB) and warm continuous retrograde cardioplegia to facilitate coronary artery bypass grafting (CABG) in a patient with cold agglutinins. As a result of their agglutinating action and resultant haemolysis, cold-reactive autoantibodies have the potential for causing morbidity and mortality when a patient is placed on hypothermic CPB and the heart is arrested with profoundly cold cardioplegia. The crux of the situation is to keep the temperature above the critical temperature of the cold agglutinin; this technique guarantees accomplishing that goal.

The treatment of gall stones

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Is an intercalated BSc degree associated with higher marks in examinations during the clinical years?

Do medical students taking an intercalated BSc degree obtain higher marks during their subsequent clinical examination? Fourteen students who did a BSc during the academic year 1988-89 were matched, by sex and preclinical grades, with students in the year they left, and with students in the year they subsequently joined. Marks or grades in 10 subsequent examinations were compared. Seven of 10 comparisons with the year the BSc students left were to the advantage of the intercalated students, and two comparisons were statistically significant. Seven of 10 comparisons with the year the BSc students subsequently joined were to the advantage of the non-intercalating students, though none reached statistical significance. No consistent short-term academic advantages arising from having done a BSc could be found. We suggest the study be replicated in other medical schools with different course examination structures.

Frantz's tumour: papillary and cystic carcinoma of the pancreas

Frantz's tumour (papillary and cystic tumour) of the pancreas is a rare neoplasm usually seen in young women. It is of low grade malignancy and deserves special note among pancreatic malignancies as it is frequently amenable to local resection and has a good long-term survival rate after excision. Three such cases have been treated at Westmead Hospital, one young male and two females. In two the disease was confined to the pancreas. In one, local invasion outside the pancreas and trans-coelomic spread to the ovaries was present at the time of diagnosis. Complete surgical removal of macroscopic disease was achieved in all three and all remain disease free between 2 and 4 years post-surgery. All have good exocrine and endocrine pancreatic function. These cases are discussed in detail. The need to be aware of this uncommon variant of pancreatic cancer is stressed. Investigation and treatment options are reviewed. The role of cytology studies in diagnosis and the potential for long-term surgical control of this tumour are highlighted on the basis of our limited experience and that presented in recent surgical literature.

Oesophageal cancer: outcome of modern surgical management

Many clinicians still associate oesophagectomy for oesophageal carcinoma with low cure rates, poor palliation and prohibitive peri-operative mortality. Surgical advances have rendered such perceptions inaccurate. A prospective study of all patients undergoing surgery for oesophageal cancer in an Australian teaching hospital between 1979 and 1993 has been undertaken. Selection, staging, pre-operative preparation, surgical technique and postoperative care were all carefully controlled. One hundred and thirty-seven patients were explored. Twenty-one were inoperable. One hundred and sixteen underwent resection with intent to cure. Hospital mortality for oesophagectomy was 1.7%. There were no cases of clinical anastomotic leakage. Eighty-nine per cent achieved excellent to good swallowing. The median survival for all cases was 14 months and the 5 year survival was 18%. Median survival for resected cases was 18 months and the 5 year survival was 26%. The long-term survival was related to postoperative stage of the disease but not to tumour type. Oesophagectomy for oesophageal cancer will restore good swallowing in 90% of cases. Operative mortality should be less than 5% and the overall 5 year survival 20-30%. Early tumours can often be cured (ca in situ 100%, stages I and II 50-60%), indicating the benefits of early detection. Poor survival in advanced disease (stage III 15%, stage IV 0%) on a background of low surgical mortality indicate the need for better staging and more effective adjuvant therapies.

Hepatocellular carcinoma in western Sydney. Aetiology, changes in incidence, and opportunities for better outcomes

OBJECTIVES

To examine the incidence of hepatocellular carcinoma (HCC) in western Sydney over the last 14 years, to assess risk factors for the disease among ethnic groups of Australian residents, and to consider the opportunities for improving its usually poor outcome.

DESIGN AND SUBJECTS

Retrospective case-record review of clinical features in all (122) patients discharged from a 900-bed tertiary-referral teaching hospital with a diagnosis of HCC from January 1979 to March 1993.

MAIN OUTCOME MEASURES

Annual number of new cases; risk factors according to birthplace; surgical resectability of tumours.

RESULTS

New cases admitted each year at least doubled between 1979-1985 and 1986-1992. This apparent increase involved individuals born in Australia (50% of all patients) as well as immigrants. Cirrhosis was found in 93% at liver biopsy or autopsy. Excessive alcohol intake was an associated risk factor for 46% of Australian-born patients and for 13% of those born overseas. Among the latter, HCC was associated with markers of hepatitis B virus infection in 64%. Since hepatitis C virus (HCV) tests became available in 1990, five of nine patients tested were anti-HCV positive. Surveillance screening of patients known to have cirrhosis detected eight cases of early HCC. Seven of these had surgical resection and all are alive.

CONCLUSIONS

New diagnoses of HCC have increased recently, irrespective of country of birth. In Australian-born patients alcoholic liver disease remains a major aetiological factor but the role of HCV requires further evaluation. Among immigrants, cirrhosis from chronic viral hepatitis accounts for most cases. We propose that prevention of cirrhosis caused by chronic viral hepatitis should have the greatest long-term impact on prevention of HCC in Australia. The role of surveillance of people with cirrhosis to detect small and potentially resectable tumours should be explored.

Non-iatrogenic trauma to the extrahepatic biliary tract

Between 1980 and 1991, 15 cases of non-iatrogenic extrahepatic biliary tract trauma have been managed at Westmead and the Royal Canberra Hospitals. There were seven cases of gall-bladder injury and eight bile duct injuries. Four cases resulted from penetrating trauma whereas 11 resulted from blunt trauma. Associated injuries were common. Cholecystectomy was the preferred method of management for gall-bladder injuries whereas the bile duct injuries were managed by a variety of techniques. There were three deaths in the series, mostly related to associated injuries. Bile duct injuries were associated with longer hospitalization than gallbladder injuries.

A case of cholangitis glandularis proliferans and cholangiocarcinoma of the common bile duct

A case of Cholangitis Glandularis Proliferans (CAGP) in association with a cholangiocarcinoma of the common bile duct as described. This is the eighth case of CAGP described and the second association with cholangiocarcinoma.

Dieulafoy's ulcer: a palpable entity?

Two cases of Dieulafoy's ulcer are reported. Diagnosis was delayed but successful surgical treatment was achieved once the lesion was located by palpation.

IATROGENIC INJURIES TO THE EXTRAHEPATIC BILIARY TRACT

Iatrogenic injuries to the extrahepatic biliary tract continue to occur and result in significant morbidity. Over the last 10 years, 26 patients have been referred to Westmead Hospital for management of iatrogenic biliary tract injuries. Of these injuries, 22 occurred during cholecystectomy, three during hepatectomy and one during a pancreaticoduodenectomy. The principles of avoidance and repair are discussed. It is concluded that these injuries, although uncommon, continue to occur and that the best treatment results are achieved in specialized hepatobiliary units.

Alpha-fetoprotein expression in hepatocellular carcinoma: a clinical study

Alpha-fetoprotein (AFP) levels were studied in 51 consecutive patients with hepatocellular carcinoma that presented to the Surgical Hepatobiliary Unit at Westmead Hospital over 12 years. Twenty-three were hepatitis surface antigen (HBsAg) positive and 13 of those patients were Asian. Thirteen patients drank more than 60 g of alcohol each day. A significantly raised level of AFP was defined as more than 20 ng/mL, and 31 of the 51 patients had AFP levels exceeding this at some stage during surveillance. Twenty-five demonstrated levels above 200 ng/mL. Univariate statistical methods suggested that men were more likely to express raised AFP than women, Asians more likely than other races, patients with chronic active hepatitis more likely than those without and those with chronic hepatitis B infection more likely than those who were HBsAg negative. Those who drank more than 60 g alcohol each day were less likely to demonstrate a raised serum AFP than those who drank less. Multivariate logistic regression demonstrated that HBsAg carriage was the only statistically significant independent determinant of a raised AFP. Age 65 years or more was associated with a chance of a raised AFP.

Hepatic cavernous haemangioma: a 10 year review

Between January 1981 and July 1991, 61 patients with hepatic haemangiomata were examined at Westmead Hospital. There were 14 males (22%) and 47 females (78%). The age range was 26-85 years with a median of 49 years. Forty-one had abdominal symptoms but these could be attributed to a haemangioma in only seven cases. There was at least one subcapsular lesion in 17 (28%). Six of the seven symptomatic lesions were subcapsular and five of these were giant haemangiomata (i.e. more than 4 cm in greatest diameter). One large symptomatic lesion was intrahepatic. No association was observed between hepatic haemangiomata and other hepatic or extrahepatic diseases. Haemangiomata were resected from six patients, four of whom were symptomatic. Symptoms improved in all four but did not resolve completely in any. Follow-up ranged from nil in five patients to 108 months in one. The median follow-up was 12 months after initial diagnosis. Ten patients showed evidence of change in their lesions or symptoms while under observation. Only three had worsening symptoms or suspected change in size of a haemangioma. This study highlights the benign, static nature of most hepatic haemangiomata. When this lesion is suspected, the diagnosis should be confirmed with ultrasound (US) and labelled red blood cell scanning (RBCS). Referral for evaluation by a specialist hepatobiliary surgery unit is necessary when symptoms are intolerable, increasing size is definitely demonstrated or the diagnosis is uncertain and cannot be established without specialized investigations. Bleeding into or from these lesions is rare.

Chronic pancreatitis beginning in childhood and adolescence

We identified 10 patients with symptoms beginning before the age of 20 years in a group of 69 patients with proven chronic pancreatitis. Six of the 10 patients were women. There was a family history of pancreatitis in three patients and alcohol exposure in seven patients. Three patients were dependent on narcotics at the time of presentation. Six of the 10 patients had pancreatic duct dilatation to 10 mm or more in diameter during observation. These six patients underwent pancreaticojejunostomy, with clinical improvement in five patients. The median time of follow-up was 19 years from presentation. No patient developed diabetes and one developed malabsorption. Only three patients were free of pain, but four other patients had only mild episodes that rarely required hospital admission. One patient died of metastatic abdominal carcinoma of unknown origin 51 years after developing familial pancreatitis. Chronic pancreatitis beginning at a young age is sufficiently common to merit special awareness. It is compatible with prolonged survival, and pancreaticojejunostomy may help if the pancreatic duct reaches sufficient size. The disease does not seem to burn out with time.

Hepatic focal nodular hyperplasia: a benign incidentaloma or a marker of serious hepatic disease?

Amongst 17 patients with hepatic focal nodular hyperplasia (FNH) encountered at Westmead Hospital between 1981 and 1990, FNH was found in association with hepatocellular carcinoma (HCC) in three (3/17), one male and two females, one of whom also had peliosis and an hepatic adenoma. FNH was also found in association with other conditions which may affect hepatic function, structure or circulation, including chronic obstructive airways disease (2), congestive cardiomyopathy (1), chronic active hepatitis (1), granulomatous hepatitis (1), coeliac artery stenosis (1) and metastatic malignant melanoma (1). This report, derived from our experience with FNH over 10 years draws attention to a possible link between FNH, hepatic malignancy and conditions which may disturb the hepatic circulation. We suggest that patients with FNH should be investigated thoroughly and an aggressive management policy should be adopted.

A phase I/II study of high-dose megestrol acetate in the treatment of metastatic breast cancer

A dose-response relationship has been suggested for medroxyprogesterone acetate in the treatment of advanced breast cancer. To determine the tolerability and efficacy of increasing doses of megestrol acetate in the treatment of metastatic breast cancer, we conducted a phase I/II study among 57 patients. Three patients each received 480, 800, and 1280 mg/d; 48 patients received 1600 mg/d. Of the 57 patients, 56 patients had had disease progression on prior hormone therapy, chemotherapy, or both. Twenty-seven patients had previously received standard-dose MA (160 mg/d). Among the 37 patients with measurable disease, high-dose megestrol acetate (HDMA) produced 6 (16%) complete responses (CRs) and 6 (16%) partial responses (PRs); 11 patients achieved stable disease (SD). HDMA resulted in improvement or stabilization in 12 of the 20 patients with evaluable, non-measurable disease. There were no responses among the 6 patients with liver metastases. Among the 27 patients who were previously treated with standard-dose MA, including 9 patients with primary treatment failure, HDMA resulted in 1 CR, 3 PRs, and 10 SD. Toxicities, which were mild and reversible, included fluid retention, hypertension, hyperglycemia, and mild congestive heart failure. Two patients had superficial phlebitis. The most profound side effect was weight gain which occurred in 43 patients (75%). This study suggests a dose-response relationship for MA in the treatment of advanced breast cancer. A randomized trial to determine the optimal dose is ongoing.

Phase I/II study of cyclophosphamide, doxorubicin, fluorouracil, and leucovorin for treatment of metastatic adenocarcinoma

Leucovorin enhances the cytotoxicity of fluorouracil (5-FU) in patients with colorectal cancer and may increase the efficacy of combination chemotherapy regimens containing 5-FU. To determine the maximum tolerated dose of 5-FU with leucovorin for use in combination with cyclophosphamide and doxorubicin, we conducted a phase I/II trial in 20 patients. The doses of leucovorin (200 mg/m2 on days 1-5), cyclophosphamide (500 mg/m2 on day 1), and doxorubicin (40 mg/m2 on day 1) were held constant, while the dose of 5-FU was escalated in cohorts of patients beginning at 150 mg/m2 on days 1-5. Cycles were repeated every 3 weeks. Significant mucositis, diarrhea, and myelosuppression were infrequently observed in patients receiving up to 250 mg/m2 5-FU on days 1-5. In contrast, at a dose of 300 mg/m2 on days 1-5, three of six patients had granulocyte count nadirs of less than 500/microL during the first cycle of therapy, and two of these three had platelet counts of less than 25,000/microL. In addition, two patients treated at this dose had significant mucosal toxic effects, and three had insufficient recovery to permit a second course by day 22. Among 14 patients with assessable breast cancer, there were one complete and nine partial responses (response rate 71%). Leucovorin modulation of 5-FU can be safely incorporated into combination chemotherapy with cyclophosphamide and doxorubicin and provides a highly active regimen for treatment of metastatic breast cancer. Further study will be required to determine whether the addition of leucovorin significantly enhances the activity of this regimen.