Rescue of immunoglobulins from insolubility is facilitated by PDI in the baculovirus expression system

A substantial fraction of immunoglobulin heavy and light chain polypeptides were insoluble when expressed in the baculovirus-insect cell expression system. In the presence of coexpressed heterologous protein disulfide isomerase (PDI), however, the solubility of the immunoglobulins was enhanced and IgG was secreted at higher levels from baculovirus-infected Trichoplusia ni insect cells. Pulse-chase experiments indicated that some immunoglobulin polypeptides were initially insoluble in the presence of PDI but subsequently were rescued in a soluble form competent for IgG assembly and secretion. Recovery of the insoluble immunoglobulins was not observed in the absence of coexpressed PDI. Even after treatment of insect cells with tunicamycin to inhibit N-glycosylation of immunoglobulin heavy chains, coexpressed PDI was able to salvage insoluble immunoglobulins and secrete these modified glycoforms. The capacity for PDI to rescue immunoglobulins was also demonstrated in vitro where immunoglobulin heavy chains and light chain dimers were salvaged from aggregates of denatured IgG. PDI-mediated rescue of proteins, perhaps assisted by chaperones and other foldases, may be important in vivo where insolubility is a common occurrence for newly synthesized polypeptides.

Vinorelbine (Navelbine), cisplatin, and concomitant radiation therapy for advanced malignancies of the chest: a Phase I study

Most patients with advanced solid tumors of the chest will have local and/or distant disease progression despite standard therapy. Vinorelbine (Navelbine; Burroughs Wellcome Co, Research Triangle Park, NC; Pierre Fabre Medicament, Paris, France) is a new semisynthetic vinca alkaloid with single-agent activity in lung cancer that recently also has been shown to act as a radiosensitizer in vitro. This study aims to define the maximum tolerated dose and dose-limiting toxicity when vinorelbine is given with cisplatin and concomitant radiation therapy. To date, 25 patients with advanced malignancies of the chest have been treated in a dose-escalation trial of vinorelbine administered once weekly with cisplatin (100 mg/m2 every 21 days) and concomitant thoracic radiation therapy (2 Gy/d x 30 fractions for 60 Gy). Vinorelbine was initially given at 20 and 25 mg/m2/wk. Acute dose-limiting toxicity was myelosuppression, which was seen at a vinorelbine dose of 25/mg/m2/wk, with grade 4 neutropenia in two of three patients and one treatment-related death from neutropenic sepsis. At vinorelbine 20/mg/m2/wk, no acute dose-limiting toxicity was seen, but grade 3 or 4 esophagitis developed in three of six patients near the end or after completion of radiation therapy. We subsequently decreased the administration of vinorelbine to weeks 1, 2, 4, and 5. Tolerance appears to be greater with this schedule; however, severe or life-threatening esophagitis at the completion of therapy continues to be observed. Given these preliminary results, it appears feasible to treat patients with advanced chest malignancies with concomitant cisplatin, vinorelbine, and radiation therapy. The significant dose reduction of vinorelbine that is necessary with concomitant radiation therapy provides the first in vivo evidence of a strong radiosensitizing effect of vinorelbine. The schedule is currently being modified to reduce the incidence of esophagitis.

Preliminary report on a phase I study of ifosfamide and vinorelbine (navelbine) in advanced non-small cell lung cancer

Vinorelbine (Navelbine; Burroughs Wellcome Co, Research Triangle Park, NC; Pierre Fabre Medicament, Paris, France), a semisynthetic vinca alkaloid, and ifosfamide have each shown activity as a single agent and in various combination-chemotherapy regimens against non-small cell lung cancer. Vinorelbine usually has been given on a once-weekly schedule. We designed a phase I study adding escalating doses of vinorelbine on a novel schedule of 3 consecutive days to ifosfamide in a dose-intensive regimen with granulocyte colony-stimulating factor. The goals were to define the dose-limiting toxicity and maximum tolerated dose of vinorelbine and to document the toxicity profile and the overall response and survival rates observed. Eligibility criteria included histologically or cytologically documented stage IIIB or stage IV non-small cell lung cancer, measurable or evaluable disease, and no prior chemotherapy. Treatment consisted of escalating doses of vinorelbine (starting at 15 mg/m2) on days 1, 2, and 3 and ifosfamide at 2 g/m2 and decreased to 1.6 g/m2 on days 1, 2, and 3. Granulocyte colony-stimulating factor was administered subcutaneously at 5 micrograms/kg on days 5 through 11 in all patients. Cycles were repeated every 21 days. Forty-two patients were treated. The median age was 58 years (age range, 34 to 75 years); 41 patients had a performance status of 0 or 1. Dose-limiting neutropenia was observed in two of three patients at the initial dose level of ifosfamide 2 g/m2 and vinorelbine 15 mg/m2. Ifosfamide was therefore decreased to 1.6 g/m2, and vinorelbine was subsequently escalated, with a maximum administered dose of 35 mg/m2. The recommended phase II dose was ifosfamide 1.6 g/m2 on days 1, 2, and 3 with vinorelbine 30 mg/m2 on days 1, 2, and 3, given with granulocyte colony-stimulating factor support, on a 21-day cycle. At the recommended phase II dose myelosuppression remained the most common toxic effect, with grade 3 or 4 neutropenia of brief duration occurring in 20 patients. Final analysis has not yet been completed, but responses have been observed at several dose levels. The maximum tolerated dose of vinorelbine given on days 1, 2, and 3 is 30 mg/m2 when given with ifosfamide at 1.6 g/m2 on days 1, 2, and 3 and granulocyte colony-stimulating factor support. Myelosuppression is the dose-limiting toxic effect. Future analyses of the data will report the overall response and survival rates in these patients.

A new method of STR interpretation using inferential logic--development of a criminal intelligence database

A short tandem repeat (STR) system consisting of seven multiplexed loci has recently been introduced in the UK to support a National strategy to create large DNA databases for criminal intelligence purposes. The process uses automated sequencers, employing dye-labelled primers. Identification of tetrameric loci such as HUMTH01 are straightforward. Sizing windows are estimated by running a series of control allelic ladders on several gels and 'unknown' samples are designated if they fall within a defined window. However, utilisation of complex STRs (eg. D21S11) characteristically have common variants which differ by just 2 bp. In addition, rare alleles are encountered which may differ by just 1 bp from a common variant. To assist with the identification of alleles, we have introduced a series of allelic ladders, so that direct comparisons with 'unknown' samples can be made on the same gel. To designate an allele, it should be within 0.5 bp of an allelic ladder marker. Not all alleles (in particular rare alleles) can be included within an allelic ladder, however their expected positions can be easily calculated by reference to existing alleles in the ladder. Measurement of band shift is also a useful diagnostic tool. A series of guidelines are described to enable reliable allelic identification. These guidelines can be converted into computer programmes which form the basis of an expert system.

A phase I-phase II study of vinorelbine with cisplatin, 5-fluorouracil, and leucovorin for advanced non-small cell lung cancer

PURPOSE

The combination of cisplatin, 5-fluorouracil, and leucovorin (PFL) has been reported to have a 29% response rate in advanced non-small cell lung cancer. Vinorelbine, a semi-synthetic vinca alkaloid, has also been reported to have single-agent activity in this disease. We designed a phase I-II study in which escalating doses of vinorelbine were added to PFL to define the dose-limiting toxicity and maximum tolerated dose of vinorelbine, and to determine the response rate and survival at the recommended phase II dose.

PATIENTS AND METHODS

This study enrolled patients between December 1991 and August 1993. Eligibility criteria included histologically or cytologically documented stage III or IV non-small cell lung cancer, measurable or evaluable disease, and no prior chemotherapy. Treatment consisted of escalating doses of vinorelbine (starting at 20 mg/m2) on days 1 and 6, cisplatin 100 mg/m2 on day 2, and 5-fluorouracil as a continuous infusion at 800 mg/m2/day for 4 days (days 2-5) with leucovorin 100 mg orally every 4 hours on days 1 through 5. Cycles were repeated every 21 days.

RESULTS

Forty patients were treated during the study. The median age of the patients was 58 (range, 33-75) and 36 patients had a performance status of 0 or 1. Dose-limiting neutropenia was observed in both patients treated with vinorelbine at 25 mg/m2. At the recommended phase II vinorelbine dose of 20 mg/m2 on days 1 and 6, myelosuppression remained the most common toxicity, with 22 patients (55%) having grade 4 neutropenia. Fifteen patients (38%) required hospital admission for neutropenic fever; two died of neutropenic sepsis. Of 33 patients evaluated, 2 patients achieved a complete response and 10 patients achieved a partial response (overall response rate, 30%; 36% of the evaluated patients). Median survival was 10.4 months for the entire cohort (16.4 months for those with stage III disease and 9.6 months for patients with stage IV disease) and 1-year survival was 45%. The overall median time to progression was 8.1 months.

CONCLUSIONS

The maximum tolerated dose of vinorelbine given on days 1 and 6 with PFL is 20 mg/m2; myelosuppression is the dose-limited factor. The response rate is similar to rates observed in prior studies of combination chemotherapy, but the median survival of patients with stage IV disease exceeds that of many other regimens.

Effects of anxiety arousal and mental stress on the vestibulo-ocular reflex

Although the subjective reports of patients suggest that anxiety may aggravate vertigo and imbalance, there has been little research into how anxiety might directly affect balance system functioning. We conducted two studies to examine the effect of anxiety and arousal on the vestibulo-ocular reflex (VOR). In the first study, pre-lest fear ratings were obtained from 20 normal subjects and 36 anxious subjects immediately prior to rotation and caloric testing. Fear ratings were significantly correlated with the maximum slow-phase velocity (SPV) of nystagmus induced by caloric testing. In the second study, we assessed the VOR response to rotation of 36 normal subjects under 3 task conditions: a) minimal alerting (counting backwards during rotation), b) physical arousal (induced by exertion prior to rotation); c) mental arousal (induced by performance of stressful mental tasks during rotation). Both the physical and mental tasks induced a significant increase in heart rate compared with the alerting condition. The maximum SPV of the nystagmus induced by rotation was significantly greater during performance of the mental task than in the other two conditions. These combined results indicate that anxiety may influence the gain of the VOR.

Paclitaxel and ifosfamide: a multicenter phase I study in advanced non-small cell lung cancer

Both paclitaxel and ifosfamide have significant single-agent activity in non-small cell lung cancer. We designed a phase I study combining escalating doses of paclitaxel, administered by 24-hour infusion, with ifosfamide given at a dose of 1.6 g/m2 daily x 3. Paclitaxel dose levels were 135, 170, 200, 250, and 300 mg/m2. The goal of the study was to determine the maximum tolerated dose and dose-limiting toxicities of paclitaxel when used in this combination. Dose escalation was possible because of the use of filgrastim, a granulocyte colony-stimulating factor. Twenty-five patients at three institutions were treated. The dose-limiting toxicity of the combination was granulocytopenia, with other toxicities being generally mild to moderate. The maximum tolerated dose of paclitaxel was 300 mg/m2, and the recommended phase II dose is 250 mg/m2. There was a suggestion of a dose-response curve with paclitaxel as all three partial responses were seen at the 250 mg/m2 dose level. An additional II patients had objective regression or stable disease lasting for 9 to 30 weeks. A phase II study of this combination is currently being planned by the Cancer and Leukemia Group B.

A phase I trial of concomitant chemoradiotherapy with cisplatin dose intensification and granulocyte-colony stimulating factor support for advanced malignancies of the chest

Concomitant chemoradiotherapy with cisplatin and combination chemotherapy in the neoadjuvant setting have both shown promising results.

PURPOSE

To identify a locally and systemically active concomitant chemoradiotherapy regimen incorporating high-dose cisplatin, interferon alfa-2a (IFN), fluorouracil (5-FU), hydroxyurea (HU) and radiotherapy.

METHODS

Phase I cohort design establishing the maximal tolerated dose (MTD) of cisplatin with and without granulocyte colony stimulating factor (GCSF). For the first six dose levels, a 4-week cycle consisted of escalating doses of cisplatin during weeks 1 and 2, IFN (week 1), and 5-FU and HU (week 2) with single daily radiation fractions of 200 cGy during days 1-5 of weeks 1-3 and no treatment in week 4. When dose-limiting neutropenia was encountered. GCSF was added during weeks 1, 3, and 4. Finally, to decrease esophagitis, the radiotherapy schedule was altered to 150 cGy twice daily during weeks 1 and 2, followed by a 2-week break (level 7).

RESULTS

Forty-nine patients with refractory chest malignancies were treated. The MTD of this regimen without GCSF was cisplatin 50 mg/m2 in weeks 1 and 2, IFN 5 million Units (MU)/m2 per day on days 1-5 in week 1, 5-FU 800 mg/m2 per day for 5 days by continuous infusion, and HU 500 mg every 12 h for 11 doses during week 2. The addition of GCSF during weeks 1, 3, and 4 allowed for escalation of cisplatin to 100 mg/m2 during weeks 1 and 2, with a decreased dose of IFN at 2.5 MU/m2 per day to avoid renal toxicity. Dose-limiting toxicity (DLT) included severe neutropenia, thrombocytopenia, and esophagitis in 5 of 13 patients. Increased thrombocytopenia in patients receiving GCSF was not observed. During hyperfractionated radiotherapy (level 7) chemotherapy doses were as above except for a reduction of 5-FU to 600 mg/m2 per day. While severe esophagitis was reduced, grade 4 thrombocytopenia became more prevalent and was seen in 6 of 7 patients. In-field tumor responses were observed in 17 of 28 evaluated patients with non-small-cell lung cancer. The median times to progression and survival were 4 and 6 months, respectively. When only patients with all known disease confined to the radiotherapy field were considered the corresponding times were 6 and 15 months, respectively. Most treatment failures occurred outside of the irradiated field.

CONCLUSIONS

(1) This intensive multimodality regimen can be given with aggressive supportive care incorporating GCSF. The recommended phase II doses for a 4-week cycle are cisplatin 50 mg/m2 week 1, and 100 mg/m2 week 2, IFN 2.5 MU, HU 500 mg every 12 h x 11 and 5-FU 800 mg/m2 per day with single fraction radiotherapy during weeks 1-3 and GCSF during weeks 1, 3, and 4. (2) GCSF can be safely administered and provides effective support of neutrophils when administered simultaneously with IFN, cisplatin, and chest radiotherapy. (3) There is synergistic renal toxicity when high doses of IFN and cisplatin are given together. (4) Hyperfractionated radiotherapy decreases the severity of esophagitis but increases thrombocytopenia. (5) Although highly toxic, response rates, time to progression and survival figures with this regimen are encouraging and support its investigation in the phase II setting.

Network support critical in choosing a lab system

When providers acquire laboratory information systems, they're looking beyond improving their lab operations to determine how the software will provide data to build computerized patient records throughout an integrated delivery system. Vendors are beginning to differentiate themselves based on how effectively their systems support the formation of enterprisewide information networks.

Provider automation. Focusing on the big picture

St. Vincent's Hospital in Birmingham, Ala., is preparing for a new world of health care by creating an enterprisewide information systems strategy rather than developing automation solutions for departmental "islands."

Outsourcing gets providers back to the basics

Information technology is advancing so quickly that many organizations can't keep up. That's why demand for the outsourcing of data processing functions is growing as providers and payers attempt to implement the latest technology while holding costs down. Those investigating outsourcing must carefully scrutinize whether an arrangement actually will cut costs, experts advise. And clients should review contract terms to ensure all expectations are spelled out.

Dose intensification--a phase I study of ifosfamide with vinorelbine (Navelbine): rationale and study design in advanced non-small cell lung cancer

A phase I trial of a combination of vinorelbine (Navelbine; Burroughs Wellcome Co, Research Triangle Park, NC; Pierre Fabre Médicament, Paris, France) and ifosfamide given on a novel schedule on 3 consecutive days with granulocyte colony-stimulating factor was conducted to establish the maximum tolerated dose of vinorelbine and the dose-limiting toxicities of this regimen. Doses of vinorelbine were escalated in cohorts of patients. Of the 29 patients enrolled at the time of data analysis, 26 were evaluable for toxicity. At the first dose level (ifosfamide 2.0 g/m2 days 1, 2, and 3; vinorelbine 15 mg/m2 days 1, 2, and 3), two of three patients had dose-limiting toxicities. The dose of ifosfamide was decreased by 20%, and dose escalation of vinorelbine was restarted. At the vinorelbine dose level of 35 mg/m2/d for 3 days, three of four patients had dose-limiting toxicities. The recommended phase II doses were established as 1.6 g/m2/d ifosfamide for 3 days and 30 mg/m2/d vinorelbine for 3 days. This study established that granulocyte colony-stimulating factor was needed for approximately 8 days. We are currently examining the feasibility of two dose levels of vinorelbine (25 mg/m2 and 30 mg/m2/d for 3 days) in combination with ifosfamide (1.6 g/m2/d) given every 2 weeks.

The marriage of financial and clinical software

As physicians feel increased pressure from managed care to operate more efficiently, they're expecting more from their practice management software than the streamlining of administrative tasks. Vendors are responding by adding clinical functions to their products.