Chemotherapy combined with bevacizumab for small cell lung cancer with brain metastases: A case report

BACKGROUND

Small cell lung cancer (SCLC) is a common and aggressive subtype of lung cancer. It is characterized by rapid growth and a high mortality rate. Approximately 10% of patients with SCLC present with brain metastases at the time of diagnosis, which is associated with a median survival of 5 mo. This study aimed to summarize the effect of bevacizumab on the progression-free survival (PFS) and overall survival of patients with brain metastasis of SCLC.

CASE SUMMARY

A 62-year-old man was referred to our hospital in February 2023 because of dizziness and numbness of the right lower extremity without headache or fever for more than four weeks. The patient was diagnosed with limited-stage SCLC. He received 8 cycles of chemotherapy combined with maintenance bevacizumab therapy and achieved a PFS of over 7 mo.

CONCLUSION

The combination of bevacizumab and irinotecan effectively alleviated brain metastasis in SCLC and prolonged PFS.

Hyperprogression after anti-programmed death-1 therapy in a patient with urothelial bladder carcinoma: A case report

BACKGROUND

Immune checkpoint inhibitors, including programmed death-ligand 1 (PD-L1) and programmed death-1 (PD-1) have recently been approved to treat locally advanced and metastatic urothelial carcinoma (UC). However, some patients experience rapid tumor progression rather than any clinical benefit from anti-PD-L1/PD-1 therapy.

CASE SUMMARY

A 73-year-old woman with bladder UC showed the progression of multiple metastases after surgery and chemotherapy for over 12 mo. The patient could not tolerate further chemotherapy. Next-generation sequencing was performed, and the results indicated that the tumor mutational burden was 6.4 mutations/Mb. The patient received the anti-PD-L1 agent toripalimab combined with albumin-bound paclitaxel. Compared with the baseline staging before immunotherapy, the patient had a treatment failure time of < 2 mo, an increase in tumor burden of > 50%, and a > 2-fold increase in progression, indicating hyperprogression.

CONCLUSION

Selecting patients most likely to respond to treatment with immunotherapeutic agents remains challenging. For older patients with advanced UC who have already exhausted multi-line chemotherapy options, immunotherapy should be used prudently if no effective biomarker is available. Further studies are required to clarify the causes and mechanisms of hyperprogression.

[Effect of electrothermal acupuncture on moderate to severe cancer pain with yin-cold stagnation: a randomized controlled trial]

OBJECTIVE

To observe the effectiveness and safety of electrothermal acupuncture therapy for patients of moderate to severe cancer pain with yin-cold stagnation.

METHODS

A total of 60 patients of moderate to severe cancer pain with yin-cold stagnation were randomized into an observation group and a control group, 30 cases in each one. In the control group, opioid painkillers (oxycodone hydrochloride prolonged-release tablet or morphine sulfate sustained-release tablet) were taken. On the basis of the control group, electrothermal acupuncture was applied at Guanyuan (CV 4), Qihai (CV 6), Zusanli (ST 36), Hegu (LI 4), Sanyinjiao (SP 6) in the observation group, 30 min each treatment, once a day for 5 days. Before and after treatment, the scores of pain numerical rating scale (NRS) and Karnofsky performance scale (KPS) were observed in the two groups. The pain remission rate, reduction of opioid painkillers and safety were compared.

RESULTS

The variation of NRS scores in the observation group were larger than the control group 3, 5 days into treatment (P<0.01, P<0.05). The variation of KPS score in the observation group was larger than the control group after treatment (P<0.05). The pain remission rate was 100.0% (30/30) in the observation group, higher than 86.7% (26/30) in the control group (P<0.05). The reduction of opioid painkillers in the observation group was larger than the control group (P<0.01). There was no adverse reaction during the treatment in the two groups.

CONCLUSION

On the basis of the conventional western medication for analgesia, electrothermal acupuncture could relieve pain, reduce the dose of opioid painkillers and improve the quality of life in patients of moderate to severe cancer pain with yin-cold stagnation, has a better safety.

Impact of palbociclib plus letrozole on patient-reported health-related quality of life: results from the PALOMA-2 trial

Background

Patient-reported outcomes are integral in benefit-risk assessments of new treatment regimens. The PALOMA-2 study provides the largest body of evidence for patient-reported health-related quality of life (QOL) for patients with metastatic breast cancer (MBC) receiving first-line endocrine-based therapy (palbociclib plus letrozole and letrozole alone).

Patients and methods

Treatment-naïve postmenopausal women with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) MBC were randomized 2 : 1 to palbociclib plus letrozole (n = 444) or placebo plus letrozole (n = 222). Patient-reported outcomes were assessed at baseline, day 1 of cycles 2 and 3, and day 1 of every other cycle from cycle 5 using the Functional Assessment of Cancer Therapy (FACT)-Breast and EuroQOL 5 dimensions (EQ-5D) questionnaires.

Results

As of 26 February 2016, the median duration of follow-up was 23 months. Baseline scores were comparable between the two treatment arms. No significant between-arm differences were observed in change from baseline in FACT-Breast Total, FACT-General Total, or EQ-5D scores. Significantly greater improvement in pain scores was observed in the palbociclib plus letrozole arm (-0.256 versus -0.098; P = 0.0183). In both arms, deterioration of FACT-Breast Total score was significantly delayed in patients without progression versus those with progression and patients with partial or complete response versus those without. No significant difference was observed in FACT-Breast and EQ-5D index scores in patients with and without neutropenia.

Conclusions

Overall, women with MBC receiving first-line endocrine therapy have a good QOL. The addition of palbociclib to letrozole maintains health-related QOL and improves pain scores in treatment-naïve postmenopausal patients with ER+/HER2- MBC compared with letrozole alone. Significantly greater delay in deterioration of health-related QOL was observed in patients without progression versus those who progressed and in patients with an objective response versus non-responders. ClinicalTrials.gov: NCT01740427 (https://clinicaltrials.gov/ct2/show/NCT01740427).

Clinical considerations of the role of palbociclib in the management of advanced breast cancer patients with and without visceral metastases

Background

This report assesses the efficacy and safety of palbociclib plus endocrine therapy (ET) in women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer (ABC) with or without visceral metastases.

Patients and methods

Pre- and postmenopausal women with disease progression following prior ET (PALOMA-3; N = 521) and postmenopausal women untreated for ABC (PALOMA-2; N = 666) were randomized 2 : 1 to ET (fulvestrant or letrozole, respectively) plus palbociclib or placebo. Progression-free survival (PFS), safety, and patient-reported quality of life (QoL) were evaluated by prior treatment and visceral involvement.

Results

Visceral metastases incidence was higher in patients with prior resistance to ET (58.3%, PALOMA-3) than in patients naive to ET in the ABC setting (48.6%, PALOMA-2). In patients with prior resistance to ET and visceral metastases, median PFS (mPFS) was 9.2 months with palbociclib plus fulvestrant versus 3.4 months with placebo plus fulvestrant [hazard ratio (HR), 0.47; 95% confidence interval (CI), 0.35–0.61], and objective response rate (ORR) was 28.0% versus 6.7%, respectively. In patients with nonvisceral metastases, mPFS was 16.6 versus 7.3 months, HR 0.53; 95% CI 0.36–0.77. In patients with visceral disease and naive to ET in the advanced disease setting, mPFS was 19.3 months with palbociclib plus letrozole versus 12.9 months with placebo plus letrozole (HR 0.63; 95% CI 0.47–0.85); ORR was 55.1% versus 40.0%; in patients with nonvisceral disease, mPFS was not reached with palbociclib plus letrozole versus 16.8 months with placebo plus letrozole (HR 0.50; 95% CI 0.36–0.70). In patients with prior resistance to ET with visceral metastases, palbociclib plus fulvestrant significantly delayed deterioration of QoL versus placebo plus fulvestrant, whereas patient-reported QoL was maintained with palbociclib plus letrozole in patients naive to endocrine-based therapy for ABC.

Conclusions

Palbociclib plus ET prolonged mPFS in patients with visceral metastases, increased ORRs, and in patients previously treated for ABC, delayed QoL deterioration, presenting a standard treatment option among patients with visceral metastases amenable to endocrine-based therapy.

Clinical trial registration

NCT01942135, NCT01740427

Palbociclib plus letrozole as first-line therapy in estrogen receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer with extended follow-up

PURPOSE

In the initial PALOMA-2 (NCT01740427) analysis with median follow-up of 23 months, palbociclib plus letrozole significantly prolonged progression-free survival (PFS) in women with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) [hazard ratio (HR) 0.58; P < 0.001]. Herein, we report results overall and by subgroups with extended follow-up.

METHODS

In this double-blind, phase 3 study, post-menopausal women with ER+/HER2- ABC who had not received prior systemic therapy for their advanced disease were randomized 2:1 to palbociclib-letrozole or placebo-letrozole. Endpoints include investigator-assessed PFS (primary), safety, and patient-reported outcomes (PROs).

RESULTS

After a median follow-up of approximately 38 months, median PFS was 27.6 months for palbociclib-letrozole (n = 444) and 14.5 months for placebo-letrozole (n = 222) (HR 0.563; 1-sided P < 0.0001). All subgroups benefited from palbociclib treatment. The improvement of PFS with palbociclib-letrozole was maintained in the next 2 subsequent lines of therapy and delayed the use of chemotherapy (40.4 vs. 29.9 months for palbociclib-letrozole vs. placebo-letrozole). Safety data were consistent with the known profile. Patients' quality of life was maintained.

CONCLUSIONS

With approximately 15 months of additional follow-up, palbociclib plus letrozole continued to demonstrate improved PFS compared with placebo plus letrozole in the overall population and across all patient subgroups, while the safety profile remained favorable and quality of life was maintained. These data confirm that palbociclib-letrozole should be considered the standard of care for first-line therapy in patients with ER+/HER2- ABC, including those with low disease burden or long disease-free interval. Sponsored by Pfizer; ClinicalTrials.gov: NCT01740427.

Abstract P5-21-03: Palbociclib (PAL) + letrozole (LET) as first-line therapy in estrogen receptor–positive (ER+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC): Efficacy and safety updates with longer follow-up across patient subgroups

BACKGROUND: Endocrine therapy (ET) has been the primary first-line (1L) therapy for ER+ ABC. In the PALOMA-2 study (NCT01740427), PAL (P)+LET (L) significantly prolonged progression-free survival (PFS; HR=0.58, P&lt;.001) after a median 23 mo follow-up (FU) (Finn et al. NEJM 2016). Here we report more mature PFS overall and in subgroups, with (w/) longer FU. The study is ongoing for overall survival FU.

METHODS: Postmenopausal pts w/ ER+/HER2- ABC and no prior systemic therapy in the ABC setting were randomized 2:1 to P (125 mg/d) + L (2.5 mg QD) or placebo (PBO) + L. Key endpoints: investigator-assessed PFS and safety. Median PFS (mPFS) was estimated (intent-to-treat population).

RESULTS: 666 pts (444, P+L; 222, PBO+L) were enrolled. Arms were well balanced: visceral (48%)/nonvisceral (52%) disease and prior ET (56%)/no prior ET (44%). After a median FU of 38 mo w/ P+L and 37 mo w/ PBO+L, mPFS was 27.6 and 14.5 mo, respectively, in the overall population (HR=0.56, P&lt;.0001; Table).

TABLE. mPFS overall and by relevant subgroupsP+LPBO+LP+L vs PBO+LmPFS, mo (95% CI)mPFS, mo (95% CI)HR (95% CI)P* Overall27.6 (22.4–30.3)14.5 (12.3–17.1)0.56 (0.46–0.69)&lt;.0001 Measurable disease23.7 (19.3–27.6)14.5 (12.3–18.5)0.63 (0.50–0.79)&lt;.0001 Nonmeasurable disease36.2 (27.6?NE)16.5 (8.3–19.6)0.39 (0.25–0.60)&lt;.0001 Visceral19.3 (16.4–24.2)12.3 (8.4–16.4)0.62 (0.47–0.81)&lt;.0005 Nonvisceral35.9 (27.7–NE)17.0 (13.8–24.8)0.50 (0.37–0.67)&lt;.0001 Bone only†36.2 (27.6–NE)11.2 (8.2–22.0)0.41 (0.26–0.63)&lt;.0001 Not bone only24.2 (19.4–27.7)14.5 (12.9–18.5)0.62 (0.50–0.78)&lt;.0001 De novo metastatic27.9 (22.1–33.4)22.0 (13.9–27.4)0.61 (0.44–0.85)&lt;.005 Prior ET24.2 (18.8–27.6)11.2 (8.4–14.5)0.54 (0.42–0.71)&lt;.0001 No prior ET30.3 (24.5–35.7)21.9 (15.9–27.4)0.59 (0.43–0.80)&lt;.0005 Nonvisceral36.2 (27.9–NE)27.6 (19.1–35.6)0.59 (0.38–0.92)&lt;.01 Visceral23.7 (16.8–30.3)13.9 (10.2–22.2)0.55 (0.36–0.85)&lt;.005 Disease sites130.4 (24.8–NE)16.5 (11.0–22.1)0.52 (0.36–0.75)&lt;.0005228.1 (19.4–NE)16.3 (11.0–27.4)0.57 (0.37–0.89)&lt;.01323.7 (19.2–27.6)13.8 (8.8–17.0)0.61 (0.46–0.82)&lt;.0005NE=not estimable. *Not adjusted for multiple analyses; 1-sided P values. †Per tumor site.

All subgroups benefited from addition of P to L. Notably, pts w/ low disease burden (bone only, nonvisceral disease, few disease sites) derived significant PFS benefit, including those w/ both nonvisceral disease and no prior ET (mPFS, 36.2 vs 27.6 mo; HR=0.59, P&lt;.01). Importantly, median time from randomization to start of 2nd subsequent systemic anticancer therapy was 39 vs 29 mo for P+L vs PBO+L (HR=0.72, P&lt;.005). There were no new safety signals w/ longer FU.

CONCLUSIONS: This is the longest FU of a phase 3 study of a cyclin-dependent kinase 4/6 inhibitor for ABC. P+L continues to consistently improve PFS vs PBO+L across all subgroups while toxicity remains manageable; notably P+L delays time to starting 2nd subsequent anticancer therapies by 10 mo. Pts w/ low disease burden or sensitivity to ET alone had PFS &gt;3 y (significant vs PBO+L), demonstrating the clinical benefit of P+ET. These data confirm P+L should be a 1L therapy option for pts w/ HR+/HER2- ABC.

Funding: Pfizer

Citation Format: Rugo HS, Finn RS, Dieras V, Ettl J, Lipatov O, Joy A, Harbeck N, Castrellon A, Lu DR, Mori A, Gauthier ER, Huang C, Gelmon KA, Slamon DJ. Palbociclib (PAL) + letrozole (LET) as first-line therapy in estrogen receptor–positive (ER+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC): Efficacy and safety updates with longer follow-up across patient subgroups [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-03.

Abstract P5-21-25: Efficacy and safety of palbociclib (PAL) + letrozole (LET) as first-line therapy in estrogen receptor–positive (ER+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC): Findings by geographic region from PALOMA-2

BACKGROUND: Previous findings from the PALOMA-2 study (N=666) demonstrated the efficacy and safety of PAL+LET as first-line ABC therapy versus placebo (PBO)+LET (Finn et al, NEJM. 2016). This analysis evaluated the efficacy and safety of PAL+LET by geographic region (North America [NA], Europe [EU], and Asia Pacific [AP]; data cutoff: Feb 26, 2016).

METHODS: Women with ER+/HER2– ABC who had not received prior systemic treatment in the advanced setting were randomized 2:1 to PAL (125 mg/d oral [3 wks on, 1 wk off])+LET (2.5 mg once daily) or PBO+LET.

RESULTS: This analysis included 267 patients from NA, 307 from EU, and 92 from AP. At baseline, demographics and disease characteristics generally were similar between regions. In the overall population (Table 1), PAL+LET demonstrated improvements versus PBO+LET in progression-free survival (PFS), objective response rate (ORR), and clinical benefit response rate (CBR). Similarly, PFS was longer and ORR and CBR were higher with PAL+LET versus PBO+LET in NA, EU, and AP subgroups (Table 1). All-grade treatment-emergent adverse events (AEs) (PAL+LET/PBO+LET) occurred in 99%/99% of patients in NA, 98%/92% in EU, and 100%/96% in AP. In the PAL+LET arm, neutropenia (all-grade/grade ≥3) was the most common AE in all regions. The incidence of neutropenia was numerically higher in AP (91%/84%) compared with NA (73%/65%) and EU (81%/62%). Grade 3 or 4 febrile neutropenia occurred in 4 (2%) NA patients, 4 (2%) EU patients, and no AP patients in the PAL+LET arm and in no patients in any of the regions in the PBO+LET arm.

CONCLUSIONS: PAL+LET showed improvement versus PBO+LET in PFS, ORR, and CBR in patients with ER+/HER2- ABC in NA, EU, and AP, with comparable magnitude of benefit between regions. With PAL+LET, neutropenia was the most commonly reported AE in all regions, with a numerically higher incidence reported in AP versus NA or EU; the safety profile was similar to previously reported results in the overall population.

Funding: Pfizer (NCT01740427)

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Table 1. PFS, ORR, and CBR Median PFSPFS HRORR,* %CBR,* % (95% CI), mo(95% CI)(95% CI)(95% CI)Overall Population    PAL+LET24.8 (22.1-NE)0.58 (0.46-0.72); P&lt;0.00155.3 (49.9-60.7)84.3 (80.0-88.0)PBO+LET14.5 (12.9-17.1) 44.4 (36.9-52.2)70.8 (63.3-77.5)NA    PAL+LET24.2 (17.5-NE)0.61 (0.43-0.85)54.3 (45.3-63.2)80.3 (72.3-86.8)PBO+LET13.8 (10.3-22.1) 50.6 (39.1-62.1)67.1 (55.6-77.3)EU    PAL+LET24.8 (22.1-NE)0.57 (0.41-0.80)55.6 (47.6-63.5)87.5 (81.4-92.2)PBO+LET16.5 (11.3-19.6) 38.2 (26.7-50.8)73.5 (61.4-83.5)AP    PAL+LET22.2 (19.4-25.7)0.49 (0.27-0.87)56.9 (42.2-70.7)84.3 (71.4-93.0)PBO+LET13.9 (7.4-22.0) 41.7 (22.1-63.4)75.0 (53.3-90.2)HR=hazard ratio; NE=not estimable; OR=objective response.*Confirmed OR in patients with measurable disease.

.

Citation Format: Gelmon KA, Castrellon A, Joy AA, Walshe JM, Ettl J, Mukai H, Park IH, Lu DR, Mori A, Bananis E, Diéras V, Finn RS. Efficacy and safety of palbociclib (PAL) + letrozole (LET) as first-line therapy in estrogen receptor–positive (ER+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC): Findings by geographic region from PALOMA-2 [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-25.

Sunitinib in pancreatic neuroendocrine tumors: updated progression-free survival and final overall survival from a phase III randomized study

BACKGROUND

In a phase III trial in patients with advanced, well-differentiated, progressive pancreatic neuroendocrine tumors, sunitinib 37.5 mg/day improved investigator-assessed progression-free survival (PFS) versus placebo (11.4 versus 5.5 months; HR, 0.42; P < 0.001). Here, we present PFS using retrospective blinded independent central review (BICR) and final median overall survival (OS), including an assessment highlighting the impact of patient crossover from placebo to sunitinib.

PATIENTS AND METHODS

In this randomized, double-blind, placebo-controlled study, cross-sectional imaging from patients was evaluated retrospectively by blinded third-party radiologists using a two-reader, two-time-point lock, followed by a sequential locked-read, batch-mode paradigm. OS was summarized using the Kaplan-Meier method and Cox proportional hazards model. Crossover-adjusted OS effect was derived using rank-preserving structural failure time (RPSFT) analyses.

RESULTS

Of 171 randomized patients (sunitinib, n = 86; placebo, n = 85), 160 (94%) had complete scan sets/time points. By BICR, median (95% confidence interval [CI]) PFS was 12.6 (11.1-20.6) months for sunitinib and 5.8 (3.8-7.2) months for placebo (HR, 0.32; 95% CI 0.18-0.55; P = 0.000015). Five years after study closure, median (95% CI) OS was 38.6 (25.6-56.4) months for sunitinib and 29.1 (16.4-36.8) months for placebo (HR, 0.73; 95% CI 0.50-1.06; P = 0.094), with 69% of placebo patients having crossed over to sunitinib. RPSFT analysis confirmed an OS benefit for sunitinib.

CONCLUSIONS

BICR confirmed the doubling of PFS with sunitinib compared with placebo. Although the observed median OS improved by nearly 10 months, the effect estimate did not reach statistical significance, potentially due to crossover from placebo to sunitinib.

TRIAL REGISTRATION NUMBER

NCT00428597.

XBP1 promoter polymorphism modulates platinum-based chemotherapy gastrointestinal toxicity for advanced non-small cell lung cancer patients

BACKGROUND

The X-box binding protein 1 (XBP1) is a critical transcription factor in the endoplasmic reticulum stress response, which is essential for the maintenance of cellular homeostasis. Here, we investigated whether the regulatory variant rs2269577 of the XBP1 gene influences clinical outcome in advanced non-small cell lung cancer (NSCLC) patients undergoing platinum-based chemotherapy.

PATIENTS AND METHODS

We recruited 663 Chinese patients with advanced NSCLC treated with platinum-based regimens and assessed the association between rs2269577 and clinical outcome. Subsequent functional analyses, including real-time quantitative PCR and dual-luciferase assays, were performed to explore possible molecular mechanisms.

RESULTS

The G/G genotype of rs2269577 was significantly associated with severe gastrointestinal toxicity compared with the homozygous C/C genotype (P=0.012, odds ratio=2.755), particularly in the female, performance status 0-1, and adenocarcinoma subgroups. No significant relevance was found between rs2269577 and treatment efficacy. In gastric epithelial cells, in vitro molecular analyses demonstrated that XBP1 mRNA expression levels decreased after treatment with cisplatin and the G allele of rs2269577 weakened the transcriptional activity of the XBP1 promoter.

CONCLUSION

This is the first study to evaluate the effect of XBP1 polymorphism on severe chemotherapy-related adverse outcomes in platinum-treated advanced NSCLC patients using both pharmacogenomics and functional molecular analyses.

Clinical research of compound zhebei granules for increasing the therapeutic effect of chemotherapy in refractory acute leukemia patients

OBJECTIVE

To observe the effects of Compound Zhebei Granules (CZG) in chemotherapy for refractory acute leukemia.

METHOD

Using a randomized, double-blind and multi-central concurrent control clinical research project, the patients conformed with the diagnostic criteria, according to the drug randomized method, were divided into a CZG group and a control group. The patients of the two groups respectively took the observation drug or a placebo 3 days before chemotherapy, and the therapeutic effects were evaluated after one course of chemotherapy. According to the clinical research project, 137 patients were enrolled, including 71 cases in the CZG group and 66 cases in the control group.

RESULTS

The clinical complete remission (CR) rate was 42.3% in the CZG group with a total effective rate of 73.2%, and it was 25.8% in the control group with a total effective rate of 53.0%, showing a statistically significant difference between the two groups (P < 0.05).

CONCLUSION

CZG can increase the clinical remission rate for refractory acute leukemia during chemotherapy.

Hypermethylation of hepatic Gck promoter in ageing rats contributes to diabetogenic potential

AIMS/HYPOTHESIS

Hepatic glucokinase (GCK) is a key enzyme in glucose utilisation. Downregulation of its activity is associated with insulin resistance and type 2 diabetes mellitus. However, it is unknown whether hepatic Gck expression is influenced by age and is involved in ageing-mediated diabetes, and whether the degree of methylation of the hepatic Gck promoter is correlated with the transcription of Gck. To address the question, we evaluated hepatic Gck transcription and promoter methylation in young (14 weeks), adult (40 weeks) and aged (80 weeks) rats.

METHODS

Hepatic glycogen, Gck expression and the kinase activity of GCK were measured in three age groups. The CpG methylation status was determined by both bisulphite direct sequencing and clone sequencing of the PCR amplificates of Gck promoter. The causal relationship between Gck methylation and mRNA expression was confirmed by treating rat primary hepatocytes with 5-aza-2'-deoxycytidine (5-Aza-CdR).

RESULTS

We have shown an age-associated decline in hepatic glycogen, Gck expression levels and the kinase activity of hepatic GCK. The eleven CpG sites studied displayed age-related progressive methylation changes in hepatic Gck promoter, which were confirmed by two methods: direct and clone sequencing. After 5-Aza-CdR treatment of rat primary hepatocytes, there was a fourfold increase in Gck expression.

CONCLUSIONS/INTERPRETATION

Our results demonstrate that an age-related increase in methylation is negatively associated with hepatic Gck expression, suggesting that DNA methylation could be involved in increasing age-dependent susceptibility to hepatic insulin resistance and diabetes. Thus, the epigenetic modification of the hepatic Gck promoter may represent an important marker for diabetogenic potential during the ageing process.

Enhancement of Intracellular Delivery of CdTe Quantum Dots (QDs) to Living Cells by Tat Conjugation

Quantum dots (QDs), as novel fluorescence probes, have shown a great potential for bio-molecular labeling and cellular imaging. To stain cellular targets, the sufficient intracellular delivery of QDs is required. In this work the tat, a typical membrane-permeable carrier peptide, was conjugated with thiol-capped CdTe QDs to form CdTe Tat-QDs, and the intracellular deliveries of CdTe QDs or CdTe Tat-QDs were compared in human hepatocellular carcinoma (QGY) cells and human breast cancer (MCF7) cells in vitro by means of confocal laser scanning microscopy. Added into the cell dishes, both QDs and Tat-QDs adhered to the outer leaflet of the plasma membrane of cells within a few minutes, but the binding amount of Tat-QDs was obviously higher than that of QDs. Then both QDs and Tat-QDs can penetrate into cells, and their cellular contents increased with incubation time but both saturated after 3 hours incubation. However the cellular levels of Tat-QDs were higher than those of QDs, with the ratio of 2.1 (+/-0.3) times in QGY cells and 1.5 (+/-0.2) times in MCF7 cells, demonstrating the enhancing effect of Tat conjugation on the intracellular delivery of QDs.

Cell culture studies of a carborane cholesteryl ester with conventional and PEG liposomes

A new cholesterol-carborane conjugate (BCH) has been synthesized as a potential targeting agent for boron neutron capture therapy (BNCT) of cancers. The compound is extremely water insoluble and was formulated in two liposomal formulations to determine if the compound could be adequately taken up by 9L rat glioma cells in cell culture. Several factors potentially affecting the cellular uptake were evaluated, such as concentration of BCH in the incubation medium, incubation time, cell confluence, and the addition of polyethylene glycol (PEG) phospholipids to the liposomal formulation. The studies indicated that the cellular uptakes of BCH in the conventional and PEG liposomal formulations were 49.1 and 45.9 microg boron/g cells, respectively. Therefore, this compound, formulated in both liposomal formulations, delivered sufficient levels of boron to cancer cells in vitro, indicating that BCH is a promising approach for use in BNCT. The uptake appeared to depend upon BCH concentration in the media as well as the confluence of the cells. The greater boron uptake by nonconfluent cells indicated that active growth of cells was a factor in the uptake of this compound.

[Specific antibodies against recombinant MSP1 of Plasmodium falciparum strongly inhibit the parasite growth in vitro]

In order to produce large amounts of protein for vaccine trials, a synthetic msp1-42 gene was inserted into Pichia pastoris expression vector and the plasmid was introduced into Pichia pastoris SMD1168 by electroporation. The expressed MSP1-42 was secreted into the protein-free medium. To measure the conformational properties of MSP1-42,16 monoclonal antibodies (11 recognizing conformational epitopes) were allowed to interact with the Pichia-derived MSP1-42, and all antibodies specific for conserved and K1 protype interacted with the protein. Interestingly, three monoclonal antibodies (e.g. 9.8, 13.1 and 7.3), that were shown not to interact with CHO-derived MSP1, could interact with the Pichia-derived MSP1-42. Rabbits were immunized with recombinant MSP1-42 formulated with CFA adjuvant four times. The rabbits were bled on the day 3 after last immunization, and total IgG isolated by protein A column from the immunized rabbits was shown to strongly inhibit the parasite growth in vitro dose-dependently, whereas IgG from rabbit with adjuvant had no inhibition.

Cell culture and animal studies for intracerebral delivery of borocaptate in liposomal formulation

The efficacy of a liposomal formulation for intracerebral delivery of borocaptate (BSH) to brain tumor cells has been investigated using cell culture to study BSH uptake and persistence and using tumor-bearing rats to determine BSH distribution in the brain. During a 16-hr incubation, cellular uptake of BSH solution or BSH liposomal formulation was similar. However, the cellular persistence of BSH greatly increased when BSH was present in liposome. The differences in cellular persistence for BSH solution and BSH-loaded liposomes were significant both in 12-hr and 24-hr incubation experiments (p < 0.05 and p < 0.01, respectively). For the studies involving tumor-bearing rats, BSH level in tumor tissue was significantly higher than that in normal brain tissue at 2 hr and 6 hr after intracerebral injection of BSH-loaded liposomes (p < 0.01). Our study indicated that the liposomal formulation enhanced cellular persistence of BSH in tumor cells and therefore favored the boron accumulation in the cells. With the prolonged physical retention of liposomes at the local injection site and the cellular retention of BSH enhanced by the liposomes, the intracerebral delivery of BSH using liposomal formulation may provide an effective boron delivery approach for boron neutron capture therapy of brain tumors.

Adenovirus 5 E1a-mediated gene therapy for human ovarian cancer cells in vitro and in vivo

The aim of this study was to investigate therapeutic efficacy of adenovirus-mediated E1a gene therapy for ovarian cancer in vitro and in vivo. Recombinant replication-deficient adenoviral vectors were prepared by superinfection of 293 cells, and then purified. The efficacy of the adenovirus vector system to infect ovarian cells was tested using different multiplicity of infection (MOI) and different times (1-4) of Ad.RSVlacZ. SKOV-3 cells (10(3) per well) were infected once with 2 x 10(4) adenovirus. The cells were harvested and counted on different days for 7 days to generate the in vitro growth curve. Tumor-bearing mice were injected intraperitoneally with ovarian cancer cells and treated by intraperitoneal injection of 100 microl (2.5 x 10(8) PFU) viral solution containing either replication-deficient Ad.E1a(+); control virus Ad.E1a(-) which is the same adenovirus as Ad.E1a(+) except for E1a deletion, or just phosphate buffered solution. The transduction efficacy increased with higher MOI and reached a plateau at the 20:1 ratio. When Ad.E1a(+) was used to transduce the HER-2/neu overexpressing human ovarian cancer cell line SKOV-3, tumor cell growth in vitro was greatly inhibited by E1a transduction. Also, Ad.E1a+ greatly inhibited tumor growth of SKOV-3-bearing mice. Immunohistochemistry analysis indicated that Ad.E1a protein was expressed in tumor tissue and expression of HER-2/neu p185 protein was suppressed. Very strong beta-gal staining was detected in tumors, and beta-gal activity in small intestine, lung, heart, stomach, liver, and kidney was detected. No beta-gal activity was detected in the tumor and other organs in control mice injected with Ad.E1a(-) or PBS. Adenovirus-type 5 E1a gene can efficaciously inhibit HER-2/neu-overexpressing ovarian cancer, and this promising procedure could greatly benefit ovarian cancer patients with high expression of HER-2/neu.

[Study on expression and resistance of the double drug resistance genes transduced into human umbilical cord blood CD34+ cells mediated by bicistronic retroviral vector]

To explore whether human umbilical cord blood CD34+ cells transduced with human aldehyde dehydrogenase class-1 (ALDH1) and multidrug resistance gene (MDR1) increase resistance to 4-Hyaroxycyclophosphophamide (4-HC) and P-Glycoprotein Effluxed Drugs, a bicistronic Retroviral vector G1Na-ALDH1-IRES-MDR1 was constructed. The vector was transduced into the packaging cell lines GP + E86 and PA317 by LipofectAMINE. Using the medium containing VCR and 4-HC for cloning selection and pingponging supernatant infection between ecotropic producer clone and amphotropic producer clone, we obtained high titer amphotropic PA317 producer clone with the highest titer up to 5.6 x 10(5) CFU/ml. Cord blood CD34+ cells were transfectced repeatedly with supernatant of retrovirus containing human ALDH1 and MDR1cDNA under stimulation of hemopoietie growth factors. PCR, RT-PCR, Southern blot, Northern blot, FACS and MTT method analyses show that dual drug resistance genes have been integrated into the genomic DNA of cord blood CD34+ cells and expressed efficiently. The transgenes recipient cells confered 4- to 7.2-folds stronger resistance to cyclophospsphamede and P-Glycoprotein Effluxes drug in comparison with the nontransduced cells. This study provided a foundation for the application of combination chemotherapy in tumor clinical trial.

Targeted drug delivery for brain cancer treatment

The blood brain barrier (BBB) and the systemic toxicity of conventional chemotherapy present obstacles to the success of future blood-borne drug therapies of brain tumors. The work with polymer-encapsulated cancer drugs suggests an alternative and more focused treatment approach. Our experimental strategy integrates direct intracerebral drug delivery, sustained drug release from liposomes or polymer implants, and increased targeting of the drug either by chemically modifying the drug or by using tumor-specific carriers. This review will present some of the recent work on targeted drug delivery for brain cancer treatment.

[Immunization of mice with plasmid DNA against malaria and regulation of antigen expression by tetracycline-controlled promoter]

Sequence of MSP1-31 of Plasmodium falciparum was constructed into eukaryotic expression vector pTRE, which could be repressed by tetracycline (Tc) and resulted in recombinant plasmid pTRE-31. The plasmid was injected into the quadriceps muscle of BALB/c mice with Tc responsive plasmid pTet-off to measure specific antibodies. The MSP1-31 prokaryotic expressed protein was used as antigen in ELISA. Results showed that mice orally administered by Tc had a seroconversion rate of 7.1% (1/14) 4 weeks after injection, whereas the control mice had a seroconversion rate of 100% and the titers of antibody were raised continusly within 12 weeks. The study suggested that the recombinant plasmids pTRE-31/pTet-off could efficiently induce humoral response against MSP1-31 of malaria. Moreover this immune response was controlled by Tc and was reversible after withdrawal of Tc dilivery. The induction of antibody by removing Tc at the fourth week after injection indicated that DNA vaccine could remain in mice and capable of expressing antigen for at least 4 weeks.

Carboplatin-loaded PLGA microspheres for intracerebral injection: formulation and characterization

The purpose of this study is to prepare and characterize injectable carboplatin-loaded poly(D,L,-lactic-co-glycolic) acid copolymer (PLGA) microspheres for the intracerebral treatment of malignant glioma. The microspheres were prepared by an acetone/mineral oil emulsion and solvent evaporation method. Preparation variables were optimized and the following processing conditions resulted in the highest drug loading and best yields of the microspheres compared with those prepared with the other variables: the PLGA concentration was 8% (w/w) in the internal phase; the emulsifier (Span 80) concentration was 8% (w/w) in the external phase; the ratio of the internal phase: the external phase was 1:8; the stirring speed was 1500 rpm; the emulsion time was 15 min; the solvent evaporation time was 3.75 hr. Microspheres so prepared were analysed for size distribution, drug loading, in vitro release and morphological characteristics. The drug release in phosphate buffer solution started with a 10-day slow release period, followed by a fast near zero order release period from 12 to 22 days. The carboplatin release in brain homogenate was slower than in phosphate buffer solution. The morphological changes of the microspheres during the in vitro degradation correlated with the drug relase profile. In conclusion, the carboplatin-loaded PLGA microspheres were specifically prepared to meet the specification as an injectable and biodegradable brain implant.

[Splicing and stability of intron in the expression retroviral vector with human clotting factor IX]

To study the role of intron in the expression of hFIX, retroviral vectors with intron containing hFIX were constructed. It is fundamental for the intron study whether the intron constructed in retroviral vector can be steadily transferred into target cell. First, we constructed two forward-orientation retroviral vectors: G1NaC-i-IX contains the exogenous intron from IL-2, and G1NaC-i'-IX contains the truncated intron I from hFIX gene, covering the splicing donor and acceptor sequences. RT-PCR result indicated that intron in the forward-orientation retroviral vector was spliced after packaging in PA317. Then, reverse-orientation retroviral vectors G1NaC-i'-IXR and G1NaPAIXi' BAM were constructed, in which the reverse and complimentary sequences of hFIX gene with intron appeared in retroviral RNA. RT-PCR assay combined with ELISA test indicated that intron was retained after packaging and hFIX gene with intron constructed in the reverse-orientation retroviral vector can be transduced intact and expressed hFIX at a high level in vitro.

Effect of gastrointestinal protein adsorption on the in vitro release of AZT from ethylcellulose microspheres

The purpose of this study was to assess the effect of gastrointestinal proteins on the in vitro release of zidovudine (AZT) from ethylcellulose microspheres, and to investigate protein adsorption as a possible mechanism that mediates this effect. AZT release from ethylcellulose microspheres was tested in the presence of different gastrointestinal proteins, both dietary (casein and albumin) and endogenous (pepsin, pancreatin, and mucin) in simulated gastric fluid and/or simulated intestinal fluid. The resulting release profiles were compared with those produced in the corresponding release media without the presence of proteins. Protein adsorption on AZT-loaded ethylcellulose microspheres was studied for the five proteins under investigation. The amounts of adsorbed proteins were determined by fluorescent spectrometry after the protein solution was reacted with fluoraldehyde reagent. All of the investigated proteins were found to slow the release of AZT from ethylcellulose microspheres. At gastric pH, ovalbumin and casein had the maximum effect on AZT release. Mucin exerted a more pronounced effect at gastric pH compared with that at intestinal pH. The negative effect of pancreatin on AZT release increased when its concentration was increased. The five proteins were found to adsorb on AZT-loaded ethylcellulose microspheres with varying quantities. The observed protein adsorption is believed to cause blockage of the small pores and channels in the microsphere structure, and consequently slow the release of AZT.

In vivo evaluation of zidovudine (AZT)-loaded ethylcellulose microspheres after oral administration in beagle dogs

The purpose of this study was to evaluate the in vivo performance of sustained-release zidovudine (AZT) microspheres after oral administration in Beagle dogs, and to establish an in vitro-in vivo correlation. Two AZT microsphere formulations as well as AZT powder were administered to four Beagle dogs. Plasma samples were analyzed by HPLC. The plasma concentration-time data was analyzed by both compartmental and noncompartmental pharmacokinetic analyses. Based on the calculated pharmacokinetic parameters, in vivo release profiles were simulated and compared with in vitro release profiles in three different release media. Significantly longer mean residence time (MRT) was observed after administration of the sustained-release microspheres compared with AZT powder. Significantly lower maximum (Cmax) concentration values and longer times to Cmax (tmax) values were also observed. Formulation I showed the longest MRT (4.4 h). AZT plasma concentration was maintained above the minimum effective concentration for approximately 10 h after administration of Formulation I. The relative bioavailability of the microsphere formulations with respect to AZT powder was not significantly different from 1. The in vitro release of the three formulations was slower in simulated gastric fluid compared with simulated intestinal fluid. The addition of enzymes and mucin to the release media significantly lowered the in vitro release rate of AZT from the microspheres formulations, but not from AZT powder. A good level of in vitro-in vivo correlation (Level A correlation) was achieved with a release medium that was composed of simulated gastric fluid with pepsin and mucin for 2 h followed by simulated intestinal fluid with pancreatin and mucin for 8 h. This in vitro model may be used to predict the in vivo release of AZT, in the further development of controlled-release AZT formulations.

Biodegradable cisplatin microspheres for direct brain injection: preparation and characterization

The objectives of the present study were to prepare cisplatin loaded-PLGA microspheres that are suitable for direct brain injection and to characterize them in terms of their physicochemical properties, in vitro drug release, and self-removal mechanism. The microspheres were prepared by emulsification/solvent evaporation method using PLGA (50:50) as the biodegradable matrix forming polymer. The physicochemical characterization encompassed the following: surface morphology, particle size, entrapment efficiency, surface area, and density. The in vitro release and in vitro degradation studies were performed in phosphate buffer and in 10% rat brain preparation. SEM micrographs revealed that the microspheres have a rough porous surface and a smooth interior. Particle size typically ranged from 180 to 250 microns with an average of 230 T microns. Entrapment efficiency was approximately 70% and was found to be dependent on the particle size. Surface area and density ranged from 0.038 to 0.025 m2/g and from 1.44 to 1.39 g/cm3, respectively. Both were also dependent on particle size. In the in vitro release study in phosphate buffer, approximately 80% of cisplatin was released over 30 days, after which the release rate plateaued. The release profile in 10% rat brain preparation was comparable in shape to that obtained in phosphate buffer. However, the release rate was lower and the total amount released by the end of the study was only 55% of the total cisplatin content. The degradation of PLGA microspheres in phosphate buffer and in rat brain homogenate correlated well with the respective release profiles. Based on the evidence of self-removal and the sustained release of cisplatin for over a month, cisplatin-loaded PLGA microspheres may be useful for local delivery to brain tumors.

Optima: a windows-based program for computer-aided optimization of controlled-release dosage forms

The purpose of this work was to develop a computer program that assists optimization of controlled-release devices, both visually and mathematically, using response surface methodology (RSM). A Windows-based computer program, Optima, which interactively implemented a number of subroutines for the optimization procedure, was developed. Optima is an integrated, user-friendly, and graphically oriented program for pharmaceutical dosage form optimization. Central composite design is implemented in the program. First- and second-order models containing up to five variables can be fitted to the data. The user can also choose between linear and exponential individual desirability functions, and use them to construct an overall desirability function that combines all the response variables in a single response. The program can predict the optimum levels of experimental variables, with respect to individual responses and/or the overall desirability. Optima has been successfully used in the development of sustained-release AZT-loaded microspheres. During the optimization process, three experimental variables were investigated and four responses were measured. The experimental design was a central composite design that was generated by the program. The response values were used by the program to calculate the individual desirability functions, which were then combined into an overall desirability function. The individual responses as well as the overall desirability function were optimized by fitting to a second-order polynomial equation. The response surfaces were generated and optimum levels of the experimental variables were predicted. The observed responses of the optimized formulation were very close to those predicted by Optima. The program proved to be a very useful, integrated tool for optimization of the controlled-release microspheres.

Preparation and evaluation of zidovudine-loaded sustained-release microspheres. 2. Optimization of multiple response variables

The formulation of zidovudine-loaded (AZT-loaded) sustained-release microspheres was prepared and optimized using response surface methodology. The objective was to use this statistical procedure to obtain a formulation with optimized overall properties. The effect of formulation variables (emulsifier concentration, drug to polymer ratio, and composition of the internal phase of the emulsion) on a number of response variables was systemically investigated. The response variables were t85, entrapment efficiency, yield, and percentage of loose surface crystals. A desirability function that combines these four response variables was constructed. A second-order polynomial equation was fitted to the data, and the resulting equation was used to predict the responses in the optimal region. All the investigated response variable were found to be highly dependent on the formulation variables, with strong interactions observed between the formulation variables. It was found that optimum overall desirability of AZT microspheres can be obtained at low levels of SDS and ethyl acetate concentrations and at intermediate levels of drug to polymer ratio. An optimized formulation was prepared under these experimental conditions and evaluated for individual responses and overall desirability. The experimental values of the response variables highly agreed with the predicted values.

Liposomal formulations containing sodium mercaptoundecahydrododecaborate (BSH) for boron neutron capture therapy

Sodium mercaptoundecahydrododecaborate or BSH is a compound most widely used for boron neutron capture therapy (BNCT). Liposome formulations containing BSH, with or without steric stabilization, were prepared as potential agents for delivery of boron compounds for BNCT. Liposomes composed of DPPC/CHOL in a molar ratio 1:1 (PEG concentration: 5 mol%) were prepared having an average diameter in the range of 100-110 nm 200 mu L of liposomes (l.88 mg phospholipid/mouse and 3.5-5.8 mg BSH/kg body weight) were injected in mice via the tail vein. Both types of liposomes resulted in a significant improvement in the circulation time of BSH compared to that obtained previously after injecting free BSH. The mean percent injected BSH remaining in circulation at the end of 24 h was 19% for the PEG-liposomes compared to the corresponding value of 7% for the conventional liposomes. The mean percent uptake by the liver and spleen was not significantly different for the two types of liposomes; the blood/RES ratios were higher for the PEG-liposomes at all time points indicating that a higher fraction of injected BSH was available in circulation. The PEG-liposomes could be further explored as a means of enhance boron drug delivery to tumor cells for BNCT.

Targeted drug delivery for boron neutron capture therapy

PURPOSE

Boron neutron capture therapy (BNCT) is a form of radiochemotherapy that is becoming increasingly important for the treatment of malignant gliomas, malignant melanomas and other forms of cancer. Targeted delivery of boron to tumors is a critical prerequisite for successful BNCT.

METHODS

Strategies that involve synthetic chemical approaches and biochemical and biophysical approaches are employed to meet this requirement. Compounds developed for targeting to tumors include borocaptate sodium (BSH) and p-boronophenylalanine (BPA) which are currently in clinical use.

RESULTS

Boronated porphyrins, nucleosides, nucleotides and other boronated compounds show potentials as targeting molecules. Conjugation of boron compounds to macromolecules such as monoclonal antibodies, epidermal growth factor and dextran is also employed for active or passive tumor targeting.

CONCLUSIONS

Boron delivery via microparticulate carriers such as liposomes, high density lipoproteins and microcapsules is also attractive for its potential application in BNCT.

Preparation and evaluation of sustained release AZT-loaded microspheres: optimization of the release characteristics using response surface methodology

The purpose of the study was to prepare and optimize a sustained release formulation of zidovudine (AZT). Ethylcellulose microspheres containing AZT were prepared using an emulsification/solvent evaporation technique. The critical formulation variables were emulsifier concentration, drug to polymer ratio, and ethyl acetate concentration in the internal phase of the emulsion. The time to release 85% of the contents of the microspheres (t85) was used as a measure for the release time. A second-year polynomial equation was fitted to the release data to systemically investigate the effect of the formulation variables on the release rate. This equation was then used to predict t85 in the optimum region. The t85 was found to be dependent on the three formulation variables, with strong interactions observed between these variables. The microspheres were characterized in terms of their particle size and surface morphology. The study indicated no overall correlation between the mean diameter of the microspheres and the t85.

Preparation and evaluation of sustained release AZT-loaded microspheres: optimization of the release characteristics using response surface methodology

The purpose of the study was to prepare and optimize a sustained release formulation of zidovudine (AZT). Ethylcellulose microspheres containing AZT were prepared using an emulsification/solvent evaporation technique. The critical formulation variables were emulsifier concentration, drug to polymer ratio, and ethyl acetate concentration in the internal phase of the emulsion. The time to release 85% of the contents of the microspheres (t85) was used as a measure for the release time. A second-year polynomial equation was fitted to the release data to systemically investigate the effect of the formulation variables on the release rate. This equation was then used to predict t85 in the optimum region. The t85 was found to be dependent on the three formulation variables, with strong interactions observed between these variables. The microspheres were characterized in terms of their particle size and surface morphology. The study indicated no overall correlation between the mean diameter of the microspheres and the t85.

Interspecies pharmacokinetic scaling of BSH in mice, rats, rabbits, and humans

Sodium mercaptoundecahydrododecaborate or BSH is an important compound for boron neutron capture therapy (BNCT). The total clearance and steady state volume of distribution of BSH in humans and in laboratory animals were analyzed as a function of species body weight using the allometric equation for interspecies scaling. Significant linear relationships were obtained between log CLt (Lh-1) and log W (kg) (r = 0.972; p = 0.028) as well as log VSS (L) and log W (kg) (r = 0.999; p = 0.0005). The corresponding allometric equations were CLt = 0.127 W0.68 and VSS = 1.557 W0.87, respectively. BSH clearance in various species was shown to be a constant fraction (0.26) of creatinine clearance, the relationship being independent of body weight. Thus BSH clearance in various species occurred at similar pace when measured by a physiological parameter (creatinine clearance) rather than chronological time. Interspecies scale-up of plasma concentration-time data for the four species using a complex Dedrick plot resulted in similar profiles. Our results indicate that the BSH data obtained in laboratory animals could be utilized to generate preliminary estimates of the pharmacokinetic parameters in humans. These parameters can serve as guidelines for better planning of clinical studies.

Pharmacokinetics of sodium mercaptoundecahydrododecaborate after intravenous injection in rats

Boron neutron capture therapy (BNCT) is a binary therapy aimed at treating various forms of cancer. Sodium mercaptoundecahydrododecaborate (Na2B12H11SH) or BSH is the compound most widely used for BNCT. The pharmacokinetics of BSH were studied in rats after intravenous bolus injection at two doses of BSH (50 mg/kg and 100 mg/kg). BSH was analyzed by a high performance liquid chromatography (HPLC) method specific to BSH. The elimination of BSH from plasma was slow; the average elimination half life was approximately 15 hr for both doses. Estimates of the steady state volume of distribution and total clearance were 2.11 +/- 0.49 liters/kg and 0.28 +/- 0.03 liters/hr/kg, respectively, for the 50 mg/kg dose and 2.06 +/- 0.38 liters/kg and 0.32 +/- 0.06 liters/hr/kg, respectively, for the 100 mg/kg dose. The differences in the mean values of the parameters for the two doses were not statistically significant; this indicates that BSH exhibits linear pharmacokinetics over the dose range studied. BSH was moderately bound to plasma proteins and the binding was linear over the concentration range studied. Approximately 60% of the drug was recovered unchanged in urine after 24 hr. When we compared our results with the limited data available in the literature on BSH disposition in rats with use of nonspecific analysis methods, it seems that the BSH disposition determined by our HPLC method is not likely to be different from the total boron disposition measured by other methods.

High-performance liquid chromatographic assay for sodium mercaptoundecahydrododecaborate in rat tissues

Mercaptoundecahydrododecaborate (BSH) is an important agent for the boron neutron-capture therapy (BNCT). A sensitive high-performance liquid chromatographic (HPLC) method was developed for measuring BSH concentrations in rat tissues. Various tissue samples containing the drug were homogenized in a 1:1 (g/ml) mixture with phosphate buffered saline. The samples were then deproteinised with 4 volumes of acetonitrile and centrifuged. An aliquot of the supernatant was dried and reconstituted in 200 microliter of Tris-HC1 buffer. The samples were subjected to precolumn derivatization using the thiol reactive monobromobimane (mBB). The drug-mBB adduct was resolved by isocratic elution from a C18 reversed-phase column. The optimized mobile phase was methanol-0.02 M phosphate buffer (43:57, v/v) containing 0.01 M tetrabutylammonium dihydrogen phosphate as the ion-pairing agent with the final pH adjusted to 7.0. The flow-rate was set at 2.0 ml/min. The adduct was monitored by UV absorption at 373 nm. The analysis was completed in less than 15 min. The detection limit was 0.5 microgram/ml (0.25 microgram of boron). The assay method was linear over a concentration range of 0.5 to 50 micrograms/ml. This assay method could be used to evaluate the BSH concentrations in different tissues in studies on the targeted delivery of BSH.

Liquid chromatographic determination of sodium mercaptoundecahydrododecaborate in rat urine and plasma after precolumn derivatization

A high-performance liquid chromatographic (HPLC) method was developed for the determination of disodium mercaptoundecahydrododecaborate (BSH) in biological fluids. Monobromobimane was used as a precolumn derivatizing agent. A stable derivative was obtained. The derivative was separated on a C18 column using reversed-phase ion-pairing chromatography and detected by a spectrophotometric detector at 373 nm. The detection limit was 200 ng/ml (0.1 ppm boron). Calibration curves were prepared for rat urine and plasma samples. The calibration curves were linear in the range of 1 microgram/ml to 100 micrograms/ml for urine samples and 0.2 micrograms/ml to 50 micrograms/ml for plasma samples.

FT-IR measurement of mercaptoundecahydrododecaborate in human plasma

A simple and rapid method for the quantitative measurement of mercaptoundecahydrododecarborate (BSH), (which presently is one of the most useful agents for Boron Neutron Capture Therapy) in human plasma was developed by using Fourier transform infrared spectroscopy. Different spacer thicknesses of the liquid sampling cell were examined and the optimal results were obtained by the 0.05 mm spacer. The subtraction of water absorbance from sample spectra resolved a B-H band at 2493 cm-1. The quantitative measurement of BSH was carried out by integration of the B-H band in the wavenumber range of 2534-2440 cm-1. However, at the lower BSH concentration range, a visual inspection of the spectrum to determine the wavenumber range was necessary so as to avoid any negative areas to be integrated. The lower limit of detection of BSH in aqueous solution and human plasma was 5 micrograms ml-1 (about 2.5 ppm of boron).

Brain mitochondrial citrate synthase and glutamate dehydrogenase: differential inhibition by fatty acyl coenzyme A derivatives

Organic acidemia is found in several metabolic encephalopathies (e.g., hepatic and valproate encephalopathies, Reye's syndrome, and hereditary organic acidemias). Although fatty acids are known to be neurotoxic, the underlying mechanisms have not been fully elucidated. It has been hypothesized that one mechanism underlying fatty acid neurotoxicity is the selective inhibition of rate-limiting and/or regulated tricarboxylic acid (TCA) cycle and related enzymes by fatty acyl-coenzyme A (CoA) derivatives. To test the hypothesis, this study has examined the effects of several fatty acyl-CoAs on citrate synthase (CS) and glutamate dehydrogenase (GDH) in brain mitochondria. At levels higher than 100 microM, butyryl-CoA (BCoA; a short-chain acyl-CoA; IC50 approximately 640 microM), octanoyl-CoA (OCoA; a medium-chain acyl-CoA; IC50 approximately 380 microM), n-decanoyl-CoA (DCoA; a medium-chain acyl-CoA; IC50 approximately 436 microM), and palmitoyl-CoA (PCoA; a long-chain acyl-CoA; IC50 approximately 340 microM) inhibited brain mitochondrial CS activity in a concentration-related manner. However, these fatty acyl-CoAs were less effective inhibitors (IC50 values for OCoA, DCoA, and PCoA being approximately 1260, 420, and 720 microM, respectively) of brain mitochondrial GDH activity. Compared to the other three acyl-CoAs investigated, BCoA was a very poor inhibitor of GDH. These results demonstrate that fatty acyl-CoAs are inhibitors of brain mitochondrial CS and GDH activities only at pathological/toxicological levels. Thus, the fatty acyl-CoA inhibition of brain mitochondrial CS and GDH is unlikely to assume major pathophysiological and/or pathogenetic importance.(ABSTRACT TRUNCATED AT 250 WORDS)

Differential effects of fatty acyl coenzyme A derivatives on citrate synthase and glutamate dehydrogenase

We investigated the hypothesis that one mechanism underlying fatty acid toxicity is the selective inhibition of rate-limiting and/or regulated tricarboxylic acid cycle and related enzymes by fatty acyl coenzyme A (CoA) derivatives by examining the effects of several fatty acyl CoAs on purified citrate synthase (CS) and glutamate dehydrogenase (GDH). The results indicate that, at pathophysiological levels, palmitoyl CoA, a long-chain acyl CoA, is a potent inhibitor of CS and GDH with IC50 values of 3-15 microM. At much higher levels (in the pathological and toxicological range), octanoyl and decanoyl CoA (medium-chain acyl CoAs) inhibited both enzymes with IC50 values of 0.4-1.6 mM. Butyryl CoA, a short-chain acyl CoA, inhibited CS (IC50 = 0.9 mM) at toxicological levels but inhibited GDH poorly. These results suggest that the long-chain fatty acyl CoA inhibition of CS and GDH may assume some pathophysiological importance in fatty acid toxicity and in metabolic encephalopathies in which organic acidemia is persistent. The findings also provide additional support for the original hypothesis.

Long-term expression of human factor IX cDNA in rabbits

In this study, rabbits were used as a model for gene therapy for hemophilia B. Human factor IX cDNA was transferred to cultured normal rabbit skin fibroblasts (RSF) by a recombinant plasmid (pCMVIX) or retrovirus (XL-IX or N2CMVIX) constructed in our laboratory. Infected fibroblasts capable of synthesizing and secreting high levels of biologically active human factor IX protein were selected and embedded in a collagen matrix. The latter was surgically implanted into rabbits as autografts or allografts. Human factor IX protein was detected in the plasma of all the grafted rabbits, and its expression has been maintained for more than 10 months at the time of writing. In addition, we have improved and simplified the method of implantation from surgically grafting the tissue-like matrix to the injection of the infected cell-collagen mixture subcutaneously. Using the latter method, human factor IX in rabbits injected with RSF-N2CMVIX reached a peak of 480 ng/ml plasma, and its expression has continued for more than 3 months at the time of writing. We suggest that the simplified method of transplantation by subcutaneous injection would offer an effective and acceptable approach to somatic cell gene therapy and may be practical for human trials.

Stage I clinical trial of gene therapy for hemophilia B

This paper describes the first human gene therapy trial for hemophilia B. Retroviruses were used to introduce human factor IX into autologous, primary human skin fibroblasts from the patients. Recombinant retroviral vector containing human FIX cDNA driven by viral LTR promoter (XL-IX) and double-copy retroviral vector driven by human cytomegalovirus enhancer-promoter (N2CMV-IX) were constructed. After the safety assessment, including soft-agar test, cell morphology observation, analysis of endotoxin, chromosome karyotype, allergic reaction test, nude mice test, routine pathological test, electromicroscopic analysis, and virus detection by PCR, etc., the engineered cells were pooled and embedded in collagen mixture, autologously injected into the patients respectively. The concentration of human FIX protein of Patient 1 increased from 71 ng/ml to 220 ng/ml, with a maximum level of 245 ng/ml. The expression of FIX has lasted for 6 months at the time of writing. The clotting activity also increased from 2.9% to 6.3%, his clinical symptoms have been alleviated obviously. The secretion rate of FIX for Patient 2 increased from 130 to 250 ng/ml, maintained at the level of 220 ng/ml for 5.5 months at the time of writing, but the clotting activity has not been increased steadily. There is no deleterious effect to be found in the two patients since the ex-vivo cells were implanted. The two patients are now under follow-up investigation. We suggested that retrovirus-mediated transfer of genes into skin fibroblasts, to be embedded in collagen and subcutaneously injected into patients, is a simple and effective approach for the gene therapy for hemophilia B.

An interactive program for pharmacokinetic modeling

A computer program, PharmK, was developed for pharmacokinetic modeling of experimental data. The program was written in C computer language based on the high-level user-interface Macintosh operating system. The intention was to provide a user-friendly tool for users of Macintosh computers. An interactive algorithm based on the exponential stripping method is used for the initial parameter estimation. Nonlinear pharmacokinetic model fitting is based on the maximum likelihood estimation method and is performed by the Levenberg-Marquardt method based on chi 2 criterion. Several methods are available to aid the evaluation of the fitting results. Pharmacokinetic data sets have been examined with the PharmK program, and the results are comparable with those obtained with other programs that are currently available for IBM PC-compatible and other types of computers.

Glucagon adsorption on polymer surfaces with alpha-helical and extended beta-strand conformations: a computational approach

The adsorption of glucagon with alpha-helical and extended beta-strand conformations on polymer surfaces was investigated using a computer simulation approach. An X-ray crystallographic structure of glucagon was employed in the study of the alpha-helical glucagon adsorption. The X-ray structure was then modified to simulate an extended beta-strand structure in the study of the beta-strand glucagon adsorption. Totally, 1632 different adsorption orientations of glucagon with each conformation were examined on polystyrene, polypropylene, polyethylene, poly(hydroxyethyl methacrylate) and poly(vinyl alcohol) surfaces. The calculation of the average adsorption energies among different orientations did not reveal any marked difference between the two conformations. However, when the lowest-energy orientations were compared, the adsorption energy of the extended beta-strand glucagon was always much lower than that of the alpha-helical glucagon, indicating that the adsorption of extended beta-strand glucagon was more energy favorable. The lower adsorption energy for the extended beta-strand glucagon than for the alpha-helical glucagon appeared to be contributed by the lower interaction potential energy of the former conformation. A greater number of the surface atoms in the extended beta-strand glucagon than in the alpha-helical glucagon was also observed. Fourier transform infrared spectroscopic (FTIR) studies in the literature showed conformational changes in adsorption of various larger proteins. Our study appears to provide a theoretical insight for the results from the FTIR studies.

Quantitative analysis of mercaptoundecahydrododecaborate by Fourier transform infrared spectroscopy

Mercaptoundecahydrododecaborate (BSH) is an important agent in boron neutron capture therapy (BNCT) of various cancers. A simple and rapid analytical method for the measurement of mercaptoundecahydrododecaborate in aqueous solution and in urine by Fourier transform infrared spectroscopy has been developed. A thin-pathlength sampling apparatus was used to minimize the strong absorption of water. The subtraction of water absorbance from sample spectra resolved a B-H band at 2493 cm-1. The quantitative measurement of BSH concentration was carried out by integrating the B-H band above baseline in the range of 2534-2440 cm-1. The lower limit of measuring the concentration of sodium BSH (Na2B12H11SH) in our experiment was 10 micrograms/ml (about 5 ppm of boron). This method measures the hydroborate (B-H) concentration instead of total boron and, thus, may be utilized to measure the BSH concentration in in vivo samples for metabolic studies.

Calculation of solvation interaction energies for protein adsorption on polymer surfaces

Of the interactions that govern protein adsorption on polymer surfaces, solvation interactions (repulsive hydration and attractive hydrophobic interactions) are thought to be among the most important. The solvation interactions in protein adsorption, however, have not been dealt with in theoretical calculation of the adsorption energy owing to the difficulties in modelling such interactions. We have evaluated the solvation interaction energies using the fragment constant method of calculating the partition coefficients of amino acids. The fundamental assumption of this approach is that the partition coefficients of amino acids between water and organic solvent phases are related to the free energies of transfer from bulk water to the polymer surface. The X-ray crystallographic protein structures of lysozyme, trypsin, immunoglobulin Fab, and hemoglobin from the Brookhaven Protein Data Bank were used. The model polymer surfaces were polystyrene, polypropylene, polyethylene, poly(hydroxyethyl methacrylate) [poly(HEMA)], and poly(vinyl alcohol). All possible adsorption orientations of the proteins were simulated to study the effect of protein orientation on the solvation interactions. Protein adsorption on either hydrophobic or hydrophilic polymer surfaces was examined by considering the sum of solvation and other interaction energies. The results showed that the contribution of the solvation interaction to the total protein adsorption energy was significant. The average solvation interaction energy ranged from -259.1 to -74.1 kJ/mol for the four proteins on the hydrophobic polymer surfaces, such as polystyrene, polypropylene, and polyethylene. On the other hand, the average solvation interaction energies on hydrophilic surfaces such as poly(HEMA) and poly(vinyl alcohol) were larger than zero. This indicates that repulsive hydration interactions are in effect for protein adsorption on hydrophilic polymer surfaces. The total interaction energies of the proteins with hydrophobic surfaces were always lower than those with more hydrophilic surfaces. This trend is in agreement with the experimental observations in the literature. This study suggests that consideration of the solvation interaction energies is necessary for accurate calculation of the protein adsorption energies.

A case of basophilic leukemia bearing simultaneous translocations t(8;21) and t(9;22)

We report a case of basophilic leukemia with simultaneous translocations of t(8;21) and t(9;22). The patient's clinical and hematologic findings were characteristic only of t(9;22) but not of t(8;21). This unusual cytogenetic phenomenon raises a challenge to the current concepts of primary chromosomal abnormalities in cancer.

Isochromosome 11q in a case of acute myelomonocytic leukemia FAB type M4

The clinical and cytogenetic findings in a 42-year-old female with acute myelomonocytic leukemia (AMMoL) were reported. At diagnosis, cytogenetic studies of bone marrow cells revealed the karyotype 45; XX, +8, -11, -17, -18, +i (11q). To our knowledge, this is the second case of AMMoL with i(11q) in the literature.

Protein adsorption on polymer surfaces: calculation of adsorption energies

In an attempt to understand the mechanisms of protein adsorption at the solid-liquid interface, we have calculated the interaction potential energy between the protein and the polymer surface by a computer simulation approach. The adsorption of four proteins--lysozyme, trypsin, immunoglobulin Fab, and hemoglobin--on five polymer surfaces was examined. The model polymers used for the calculation were polystyrene, polyethylene, polypropylene, poly(hydroxyethyl methacrylate), and poly(vinyl alcohol). All possible orientations of the protein on the polymer surfaces were simulated and the corresponding interaction energies for the initial contact stage of protein adsorption were calculated. In the calculation of interaction energies, the hydrophobic interaction was not treated explicitly owing to the difficulty in the theoretical treatment. The results showed that the interaction energy was dependent on the orientation of the protein on the polymer surfaces. The energy varied from -850 to +600 kJ/mol with an average of about -155 kJ/mol. The interaction energy was also dependent on the type of polymer. The average interaction energies of the four proteins with poly(vinyl alcohol) were always lower than those with the other polymers. The interaction energy was not dependent on the protein size. It was found that the dispersion attraction played the major role in protein adsorption on neutral polymer surfaces.