Potency preservation after three-dimensional conformal radiotherapy for prostate cancer: preliminary results

We sought to assess potency preservation after three-dimensional conformal radiotherapy (3D-CRT) in prostate cancer patients eligible for radical prostatectomy, conventional radiotherapy, 3D-CRT, or transperineal prostate implantation. Patients with more advanced disease are commonly treated with hormonal therapy, which can cause impotence, and were consequently excluded from the analysis. Between December 1991 and June 1998, 198 prostate cancer patients were treated with 3D-CRT at the University of California, Davis Medical Center. Fifty-two of these patients had a pretreatment prostate-specific antigen (PSA) level of 10.0 ng/ml or less, a Gleason score of 6 or less, and a 1997 AJCC clinical stage T1bN0M0 to T2bN0M0. One patient was not evaluable. None of the 51 evaluable patients had diabetes mellitus. In 40 patients, the prostate gland only was irradiated to a total dose of 66 to 79.2 Gy by using daily 1.8-Gy fractions. In 11 patients, the prostate and seminal vesicles were treated to 44 to 55.8 Gy. Lymph nodes were not included in the clinical target volume. The median age was 68 years, and the median length of follow-up was 15 months. Potency in this study is defined as an erection sufficient for vaginal penetration. Kaplan-Meier analysis was used to describe potency as a function of time after 3D-CRT. Of the 51 evaluable patients, 35 (69%) were potent, 15 were impotent, and 1 was sexually inactive before 3D-CRT. Kaplan-Meier estimates of the potency preservation rates 1, 2, and 3 years after 3D-CRT are 100%, 83%, and 63%, respectively. On multivariate analysis, age, total radiation dose, and a history of transurethral resection of the prostate did not significantly affect potency preservation rates. Three (43%) of 7 patients who became impotent after 3D-CRT and used sildenafil were subsequently able to achieve erections sufficient for vaginal penetration. The preliminary results reported herein suggest that approximately two thirds of prostate cancer patients will retain their potency 3 years after 3D-CRT. Further follow-up is necessary to assess long-term potency after 3D-CRT. Sildenafil should be considered in patients who develop radiation-induced impotence.

Mechanisms involved in the potentiation of melphalan by the bioreductive compound THNLA-1 in vitro

9-[3-(2-Nitro-1-imidazolyl)propylamino]-1,2,3,4-tetrahydroacridine hydrochloride (THNLA-1) is a 2-nitroimidazole-based, weakly DNA-intercalating bioreductive agent that significantly potentiates the toxic effects of commonly used antitumor drugs such as melphalan (L-PAM) or cis-DDP in sensitive or resistant cell lines in culture, as well as in solid tumors in mice. Potentiation in vitro was observed when cells were preexposed to THNLA-1 under hypoxic conditions before exposure to L-PAM under aerobic conditions. In this study we investigated possible mechanisms involved in the potentiation of L-PAM by THNLA-1 in V79 Chinese hamster cells. Limited depletion of glutathione with buthionine sulfoximine or THNLA-1 under hypoxic pretreatment conditions accounted for only 8.3% of the potentiation induced by THNLA-1. However, DNA, RNA, and protein synthesis were inhibited in a synergistic way in cells preexposed to THNLA-1 under hypoxic conditions (2 h, 37 degrees C) and then coexposed to various doses of L-PAM under aerobic conditions (1 h, 37 degrees C). Cell cycle analysis by flow cytometry showed a slow traverse through the S phase in the L-PAM-alone-treated cells. However, this phenomenon was more prominent in the THNLA-1 plus L-PAM-treated cells. Under aerobic co-incubation conditions with L-PAM, no difference was observed in the cell cycle of L-PAM-alone-treated cells vs. THNLA-1 plus L-PAM-treated cells. Significantly increased apoptosis was observed in the hypoxia-pretreated cells with THNLA-1, 12 and 24 h posttreatment. Comet and alkaline elution assay analysis showed increased DNA cross-links in the hypoxia-pretreated cells with THNLA-1 compared to the L-PAM-alone-treated cells. Finally, potential lethal damage repair was totally suppressed only in the hypoxia-pretreated cells with THNLA-1. In conclusion, DNA damage and hindrance in its repair are the most important mechanisms in the potentiation of L-PAM by THNLA-1, under hypoxic pretreatment conditions.

Preliminary results of three-dimensional conformal radiotherapy as salvage treatment for a rising prostate-specific antigen level postprostatectomy

The purpose of this study is to determine the effectiveness of three-dimensional conformal radiotherapy delivered to the fossa of the prostate and seminal vesicles as salvage treatment for a prostate-specific antigen (PSA) level that becomes undetectable and subsequently begins to rise postprostatectomy. Between August 1994 and December 1997, 14 patients with prostate cancer whose PSA became undetectable after a radical prostatectomy subsequently developed a rising PSA, had no evidence of metastatic disease, and were treated with three-dimensional conformal radiotherapy at the University of California, Davis Cancer Center. Gleason scores ranged from 4 to 9 (29% of the patients had a Gleason score > or =8). The seminal vesicles were involved in three (21%) cases and the surgical margins were involved in seven (50%) cases. PSA values ranged from 0.3 to 6.7 (median: 0.7) ng/ml at the start of radiotherapy. Daily 1.8-2.0-Gy fractions were administered to total doses at isocenter ranging from 60.6 to 74.2 (median: 64.9) Gy. None of the patients received hormonal therapy. Follow-up ranged from 13 to 36 (median: 22) months. For patients with a preradiotherapy Hybritech PSA < or = 1.0 ng/ml, the Kaplan-Meier estimate of the 2-year biochemical disease-free survival rate is 67%, whereas for patients with a preradiotherapy PSA more than 1.0 ng/ml, the 2-year biochemical disease-free survival rate is 20% (p = 0.17). Because of the small number of patients, the difference is not statistically significant. A positive microscopic margin had no impact on the results obtained with salvage radiotherapy. Only one of four patients with a poorly differentiated adenocarcinoma remains free of disease. Acute toxicity was mild and did not require medication (Radiation Therapy Oncology Group grade I): four (29%) patients experienced genitourinary morbidity and three (21%) patients experienced gastrointestinal morbidity. With regard to late toxicity, one (7%) patient developed a urethral stricture requiring dilatation (Radiation Therapy Oncology Group grade III). All five patients who were potent at the start of radiotherapy remain potent. Medicare's median reimbursement for salvage three-dimensional conformal radiotherapy in this study ($7,512 in 1999 U.S. dollars) is equivalent to its reimbursement for a 17-month course of goserelin hormonal therapy. Patients with prostate cancer who develop an undetectable followed by a rising PSA postprostatectomy should be referred for salvage treatment with radiotherapy when their PSA is still less than or equal to 1.0 ng/ml. Salvage three-dimensional conformal radiotherapy is well tolerated and is less expensive than more than 17 months of goserelin.

Acute toxicity of three-dimensional conformal radiotherapy in prostate cancer patients eligible for implant monotherapy

PURPOSE

To assess the acute toxicity of three-dimensional conformal radiotherapy (3D-CRT) in prostate cancer patients eligible for implant monotherapy.

METHODS AND MATERIALS

Between December 1991 and June 1998, 198 prostate cancer patients were treated with 3D-CRT at the University of California Davis Medical Center. Fifty-two of these patients had a prostate-specific antigen (PSA) level </= 10.0 ng/ml, Gleason score </= 6, and a 1997 AJCC clinical stage T1bN0-T2bN0. Eleven (21%) patients received radiotherapy to the prostate and seminal vesicles; the remaining patients were treated to the prostate only. The 3D-CRT treatment planning guidelines in Radiation Therapy Oncology Group (RTOG) 9406 were followed after 1994 (similar treatment planning was used before the protocol became available). Typically, 4 oblique and 2 lateral fields were treated. All patients were seen at least weekly while under treatment, 1 month postirradiation and then every 3 months. Total radiation doses ranged from 66.0-79.2 Gy, with a median dose of 73.8 Gy in 41 fractions over 8 weeks. Acute toxicity is described according to the RTOG acute toxicity scoring system.

RESULTS

Overall, 3D-CRT was well-tolerated: 29% of patients experienced RTOG Grade 1 and 27% experienced Grade 2 acute lower gastrointestinal (GI) toxicity. Forty percent and 33% of patients experienced Grade 1 and 2 acute genitourinary (GU) toxicity, respectively. As expected, more acute morbidity, especially GI, was observed with a larger clinical target volume (prostate and seminal vesicles versus prostate only; p = 0. 05). Neoadjuvant hormonal therapy did not increase the incidence or severity of radiation-induced side effects. No acute toxicity >/= Grade 3, e.g., hourly nocturia, gross hematuria, diarrhea requiring parenteral support, narcotics for pain control, or catheterization for acute urinary retention, was observed.

CONCLUSION

Although relatively high doses of radiation are delivered to prostate cancers with 3D-CRT compared with conventional radiotherapy, 3D-CRT is surprisingly well-tolerated. No patients in the cohort eligible for implant monotherapy experienced acute toxicity >/= Grade 3.

[Raman spectra of complexes of rare earth nitrate with histidine]

Raman spectra of solid complexes RE(His)(NO3)3 x H2O (RE = La-Nd, Sm-Lu, Y; His = L-alpha-histidine ) have been investigated. The results indicate that RE3+ coordinates with one O atome of carboxyl group in the complex, while amino group and imidazole ring do not take part in coordination and NO3 is double coordination. The vibration peaks of carboxyl group delta(v)COO-(as-s) were plotted against the atomic number of the lanthanoids, which obeys Oddo-Harkins law.

NLCQ-1, a novel hypoxic cytotoxin: potentiation of melphalan, cisDDP and cyclophosphamide in vivo

PURPOSE

To investigate in vivo interactions between the recently developed bioreductive agent 4-[3-(2-nitroimidazolyl)-propylamino]-7-chloroquinoline hydrochloride (NLCQ-1) and the chemotherapeutic agents melphalan (L-PAM), cis-platin (cisDDP) and cyclophosphamide (CPM).

METHODS AND MATERIALS

EMT6 and FSaIIC tumor cells were inoculated (subcutaneously) into the leg(s) of female Balb/c and male C3H mice, respectively. Treatment was initiated at 10 mm (EMT6) and 5 mm (FSaIIC) mean tumor diameter. The in vivo-in vitro and tumor regrowth assays were used, respectively, as endpoints. Bone marrow toxicity studies were also performed when the in vivo-in vitro assay was used. Drugs were given by i.p. injection. Tumors were excised 18-h after chemotherapeutic drug administration (Balb/c mice) or measured daily until three times their original size (C3H mice). The optimum administration schedule for potentiation between NLCQ-1 and each chemotherapeutic drug, as well as dose modification factors (DMF) at the optimum time, were determined with the in vivo-in vitro assay. When the tumor regrowth assay was used, each chemotherapeutic agent was given either as a single dose or as a split dose over two consecutive days at the optimum administration time after a 10 mg/kg NLCQ-1 i.p. injection.

RESULTS

NLCQ-1 (at 0.33 times MTD), strongly potentiated the antitumor effect of L-PAM, cisDDP and CPM without concurrent enhancement in bone marrow toxicity. Potentiation was strictly schedule dependent and the optimum effect (1.5 to 2 logs killing beyond additivity) was observed when NLCQ-1 was given 60-, 45-, and 110-min before L-PAM, cisDDP, and CPM, respectively. The DMF values at 30% survival were 2.5, 1.9, and 3.8 for L-PAM, cisDDP, and CPM, respectively. DMF values for bone marrow toxicity at 50% survival were ca. 1 for all chemotherapeutic drugs. Pretreatment with NLCQ-1 resulted in 4-12 days extra delay in the regrowth of FSaIIC tumors.

CONCLUSIONS

These results support the clinical investigation of NLCQ-1 as a chemosensitizer.

9-[3-(2-Nitro-1-imidazolyl)propylamino]-cyclopenteno[b]quinoline hydrochloride (NLCPQ-1). A novel DNA-affinic bioreductive agent as chemosensitizer: mechanistic studies. II

NLCPQ-1 is a novel, weak, DNA-affinic bioreductive compound with enhanced chemosensitizing ability for commonly used chemotherapeutic agents, both in vitro and in vivo. In the present report we investigated possible mechanisms involved in the potentiation of cis-DDP and L-PAM in V79 cells. Potentiation was observed when cells were pretreated under hypoxic conditions with NLCPQ-1 prior to their aerobic exposure to each chemotherapeutic agent studied and in the presence of NLCPQ-1. The dominant mechanisms, under hypoxic pretreatment conditions, participating in the potentiation were: a) extensive DNA damage, as measured by the comet and alkaline elution assays, b) DNA, RNA, and protein synthesis inhibition, c) significant delay in the traverse through the S phase, as observed by flow cytometry, and possibly d) suppression of PLD repair. Apoptosis was also detected 36 h posttreatment in the chemotherapeutic drug-treated as well as the combination drug-treated cells. Glutathione depletion by NLCPQ-1 metabolites under hypoxic conditions was also involved in the potentiation process, but its contribution in potentiation was minimal.

[Ex vivo study of ultraviolet-B inactivating immunocompetence and hematopoietic potential of cord blood]

OBJECTIVE

To determine the differences of the effect of ultraviolet-B(UVB) on lymphocyte and hematopoietic progenitor cell in cord blood.

METHODS

The viability, proliferative response and stimulatory activity in mixed lymphocyte culture (MLC), colony forming unit-granulo-monocyte (CFU-GM) colony growth and percentage of CD34+ cell of cord blood in Hanks medium after 0, 5, 10, 20, 50 mJ/cm2 UVB-irradiation were compared.

RESULTS

Like the proliferative response and stimulatory activity, CFU-GM colony also showed UVB-irradiation dose dependent decrease. However, much less colonies were destroyed by UVB irradition less than 10 mJ/cm2. More obvious differences were found when 20%(vol/vol) bovine serum was added to the MNC medium. The percentage of CD34+ cell remained unchanged after UVB exposure.

CONCLUSION

A lower dose of UVB exposure can slectively inactivate cord blood lymphocyte and antigen presenting cell while sparing hematopoietic progenitor cells. The data indicates the possibility of utility of UVB irradiation for graft-versus-host disease prophylaxis in cord blood transplantation.

[Clinical evaluation and immunomodulatory study of cefodizime]

To investigate the efficacy, safety and immunomodulating activities of cefodizime in immunocompromised patients with infections, we carried out a randomized controlled prospective study of cefodizime vs ceftizoxime in 107 patients. The total effective cure rate and bacterial eradication rate were 87.3%, 61.8% and 89.3% in cefodizime group and 82.7%, 59.6% and 90.6% in ceftizoxime group. Drug tolerance was similar in the two groups, and side effect was mild and transient, mainly gastrointestinal reactions. Cefodizime had effect on both phagocyte and lymphocyte functions: enhancing the phagocytie rate, phagocytic index and bacterial killing activity, increasing the number of CD4+ lymphacyte and the ratio of CD4+/CD8+, stimulating NK cell activity and enhancing expression of IL-2R of active lymphocyte. Meanwhile ceftizoxime had no effect on any of the parameter mentioned above. The result showed that cefodizime is effective and safe in the treatment of LRTI, upper and complicated UTI in immunocompromised patients, as well as possessed immunomodulating activities.

9-[3-(2-Nitro-1-imidazolyl)propylamino]-cyclopenteno[b]quinoline hydrochloride (NLCPQ-1): a novel DNA-affinic bioreductive agent as chemosensitizer. I

9-(3-(2-Nitro-1-imidazolyl)propylamino]-cyclopentano[b]quinoline hydrochloride (NLCPQ-1) is one member of a limited series of 2-nitroimidazole-linked derivatized quinolines we have synthesized to be weak DNA binding compounds. On a concentration basis, NLCPQ-1 is the most potent analogue of the series as a radiosensitizer and cytotoxin of hypoxic cells in vitro and in vivo. This improved efficacy compared to untargeted nitroimidazolic bioreductive compounds has been mainly attributed to its weak DNA binding. In the present study, we investigated the ability of NLCPQ-1 to act synergistically with 4-[bis(2-chloroethyl)amino]-L-phenylalanine (L-PAM, melphalan) or cis-diamminedichloroplatinum (cis-DDP, cisplatin) against tumor cells in vitro and in vivo. We demonstrated that 7 microM NLCPQ-1 potentiated the toxic effect of cis-DDP and L-PAM against V79 cells under hypoxic pretreatment conditions with dose modification factors (DMF) of 2.6 and 2.4, respectively, measured at 0.1 survival. Potentiation was dependent on the concentrations of both the chemotherapeutic agent and NLCPQ-1 as well as on the duration of the hypoxic pretreatment with NLCPQ-1. No potentiation was observed under aerobic cotreatment conditions in vitro. Significant synergism was observed when 15 mg/kg NLCPQ-1 was administered IP at various time intervals before a single dose of L-PAM (5 mg/kg) or cis-DDP (5 mg/kg) in Balb/c mice bearing EMT6 tumors. The in vivo/in vitro assay was used as the investigational endpoint and either the fractional product or isobologramic analysis was used to determine synergistic interactions.

[The development of an Co-60 teletherapy missing tissue filling and compensating paraffin phantom and support]

The manufacturing way of missing tissue compensating paraffin phantom and the development of support are introduced in this article. They are designed to solve the problem that the dose is bad-distribated when the wedged plates are taken the places of tissue compensator in the course of missing tissue teletherapy. The manufacturing way of missing tissue compensating paraffin phantom is simple, Keeping paraffin phantom in position is accurate and the operating is simple and convenient.

Modulation of multidrug resistance gene (mdr-1) with antisense oligodeoxynucleotides

1. Multidrug resistance is the major obstacle to successful cancer chemotherapy. Circumventing multidrug resistance therefore represents a high priority for clinical anti-cancer treatment. Among many reversal strategies, antisense oligodeoxynucleotides may offer a molecular targeting tool for overcoming cellular multidrug resistance. 2. Two 17-mer phosphorothioate antisense oligomers, complementary to the 5' end of the ATG initiator codon-containing region and loop-forming site (located at nucleotides 991-1007 from the first ATG codon) in mdr-1 cDNA sequence, were synthesized. The purpose was to study their effects on the function and expression of P-glycoprotein and mdr-1 gene. 3. The results showed that 10 mumol/l antisense oligomers could significantly inhibit the growth of multidrug resistant K562/Adm cells cultured in adriamycin-containing medium. No such effect was observed for parental (sensitive) K562/S cells. Intracellular daunorubicin accumulation increased greatly in the K562/Adm cells after they were treated with oligomers for 48 h and P-glycoprotein synthesis was strikingly reduced. 4. Further investigation with [alpha-32P]dCTP incorporation by the reverse transcriptase-polymerase chain reaction method revealed that antisense oligomers could result in a reduction in the level of mdr-1 mRNA, probably through hindering mdr-1 gene transcription. 5. The high reversal efficiency and specificity of antisense oligomers in regulating mdr-1 gene expression suggest a potential clinical application in gene therapy for drug resistant malignancies.

THNLA-1 as radio/chemosensitiser of EMT-6 tumours in mice

THNLA-1 contains a 2-nitroimidazole tethered to 9-amino-1,2,3,4-tetrahydroacridine. Compared with its parent acridinic analogue, NLA-1, THNLA-1 is a weak DNA-affinic bioreductive compound with a greater mobility along the DNA backbone, decreased aerobic toxicity, greater hypoxic selectivity and a superior in vitro therapeutic index. Also, THNLA-1 behaves as a radio/chemosensitiser in vitro. In this report we have expanded our radio/chemosensitisation studies in vivo, using the EMT-6 mouse mammary tumour model in balb/c mice and the in vivo-in vitro assay. THNLA-1 was given i.p. ( < or = 0.5 ml in saline) at various time intervals before a single dose of 20 Gy whole-body irradiation. Tumours were excised immediately or 24 h after irradiation. Radiosensitisation studies with SR-2508 (i.v.) have been performed in a similar way for comparison purposes. THNLA-1 demonstrated the same radiosensitising effect as SR-2508 but with 19-fold less dose (mmol kg-1). The optimum effect was observed when THNLA-1 was given 1 h before irradiation and the tumours excised 24 h after irradiation. Chemosensitisation studies in the same tumour model and using cis DDP showed that the cytotoxic effect of cis-DDP (5 or 8 mg kg-1, i.p.) was significantly enhanced with 30 or 45 mg kg-1 THNLA-1 given approximately 3 h before cis-DDP. A similar potentiating effect was observed when NLA-1 (27 or 30 mg kg-1) was used, but toxicity was also observed at the higher dose. Limited toxicity studies showed that THNLA-1 is well tolerated up to at least 70 mg kg-1 as a single dose, for more than 40 days.

[Content determination of baicalin by ultraviolet second order derivative spectra]

By the method of UV second order derivative spectra, baicalin in contents in the Lanqin Oral Liquid were determined. Able to eliminate the influence of other constituents, this method is simple, rapid, sensitive and accurate.

9-[3-(2-Nitro-1-imidazolyl)propylamino]-cyclopenteno[b]quinoline hydrochloride (NLCPQ-1). A novel DNA-affinic bioreductive agent as cytotoxin and radiosensitizer

Our recent studies with 9-[3-(2-nitro-1-imidazolyl)propylamino]-1,2,3,4,-tetrahydroacridine++ + hydrochloride (a 2-nitroimidazole-linked 1,2,3,4-tetrahydroacridine derivative) shows that less effective DNA binding indeed leads to a hypoxic radiosensitizer and cytotoxin of superior in vitro therapeutic index to the fully aromatic nitroimidazole-linked acridine series, which strongly bind to DNA through intercalation. Extending our investigations in this area, we have synthesized and have been evaluating five more nitroimidazoles tethered to quinoline-based chromophores. Here, the in vitro and limited in vivo results of 9-[3-(2-nitro-1-imidazolyl)-propylamino]cyclopenteno[b]quinoline hydrochloride (NLCPQ-1) are presented. On a concentration basis, NLCPQ-1 was the most potent analog so far tested of the above mentioned small series as radiosensitizer or cytotoxin of hypoxic cells. It had a hypoxic selectivity of 9-12 in various cell lines, a C1.6 of approximately equal to 7 microM, and a sensitization enhancement ratio of 3.2 at 50 microM (approximately equal to 27% of the IC50(A)) in V79 cells. Its in vitro therapeutic index (defined as IC50(A)/C1.6) was 25-30 vs. 11 for 9-[3-(2-nitro-1-imidazolyl)propylamino]acridine hydrochloride. The partition coefficient in octanol/water was 0.30 +/- 0.01. The uptake factor (intracellular vs. extracellular concentration) was increased by increasing input concentration and reached 92 at 80 microM. When NLCPQ-1 was administered i.p. at 15 mg/kg, at various time-intervals before a single, 20 Gy radiation dose in Balb/c mice bearing EMT6 tumors, significant synergism was observed. The in vivo-in vitro assay was used as an endpoint, and the fractional product analysis was used to determine synergistic interactions. No toxicity was observed at doses up to 50 mg/kg NLCPQ-1 in nontumor-bearing Balb/c mice.

THNLA-1: a DNA-targeted bioreductive agent as chemosensitizer in vitro and in vivo

THNLA-1 is a recently synthesized 2-nitroimidazole based, DNA-affinic bioreductive agent. It features a tetrahydroacridinic chromophore, which allows loose binding to DNA and therefore greater mobility along its backbone. THNLA-1 was proved to be a very good radiosensitizer and cytotoxin of hypoxic cells in vitro with an improved therapeutic index compared to the fully aromatic analog NLA-1. In this report we investigated the interaction of THNLA-1 with cis-DDP or L-PAM in the sensitive V79 and resistant OVCAR cells, using various schedule protocols. Also, the THNLA-1/cis-DDP interaction in balb/c mice has been investigated, using the EMT-6 mouse tumors. Isobologramic as well as fractional product concept analysis, clearly showed that synergistic interaction occurs between THNLA-1 and each chemotherapeutic agent, under hypoxic pretreatment conditions of the cells with THNLA-1 in vitro. The dose modification factor (DMF) values obtained in the resistant OVCAR-3 cells are similar to those obtained for the approximately 4 times more sensitive V79 cells. Therefore, the DMF value for e.g. L-PAM at 0.1 survival fraction, is approximately 2.76 when 15 microM THNLA-1 was used in OVCAR-3 cells, and approximately 2.50, when 10 microM THNLA-1 was used in V79. The supra-additive effect is dependent on the hypoxia-pretreatment time with THNLA-1, on THNLA-1 concentration and on the concentration of the chemotherapeutic drug. The limited in vivo study showed that THNLA-1, at doses significantly lower than its MTD, strongly potentiates the killing effect of cis-DDP and that the optimum effect during the combination treatment was observed when THNLA-1 was administered i.p., 2.5-3.0 h before cis-DDP. Toxicity studies in balb/c mice (without tumors) showed that THNLA-1 is well tolerated up to at least 70 mg/kg for more than 40 days while no toxicity was observed with the combined drugs used in our experimental protocol. These results are promising for the potential clinical use of THNLA-1 as an adjuvant in chemotherapy.

Simulations of Atmospheric Variability Induced by Sea Surface Temperatures and Implications for Global Warming

An atmospheric general circulation model was forced with observed interannual changes in the global sea surface temperatures (SSTs) for the period 1982 to 1993. The simulated seasonal surface air temperature patterns over land areas closely resemble the observed. Over most of the globe, the patterns also resemble those associated with EI Niño events and are also reproduced in simulations with weak warm tropical SSTs near the date line. An exception is northern Asia, where the mechanisms for the observed warming are unclear. The results suggest that enhanced air-sea interactions resulting from recent, more persistent warm oceanic conditions in the tropics contributed to the observed global warming trend during this period.