LSD1 inhibition suppresses ASCL1 and de-represses YAP1 to drive potent activity against neuroendocrine prostate cancer.

Lysine-specific demethylase 1 (LSD1 or KDM1A ) has emerged as a critical mediator of tumor progression in metastatic castration-resistant prostate cancer (mCRPC). Among mCRPC subtypes, neuroendocrine prostate cancer (NEPC) is an exceptionally aggressive variant driven by lineage plasticity, an adaptive resistance mechanism to androgen receptor axis-targeted therapies. Our study shows that LSD1 expression is elevated in NEPC and associated with unfavorable clinical outcomes. Using genetic approaches, we validated the on-target effects of LSD1 inhibition across various models. We investigated the therapeutic potential of bomedemstat, an orally bioavailable, irreversible LSD1 inhibitor with low nanomolar potency. Our findings demonstrate potent antitumor activity against CRPC models, including tumor regressions in NEPC patient-derived xenografts. Mechanistically, our study uncovers that LSD1 inhibition suppresses the neuronal transcriptional program by downregulating ASCL1 through disrupting LSD1:INSM1 interactions and de-repressing YAP1 silencing. Our data support the clinical development of LSD1 inhibitors for treating CRPC - especially the aggressive NE phenotype. Statement of Significance: Neuroendocrine prostate cancer presents a clinical challenge due to the lack of effective treatments. Our research demonstrates that bomedemstat, a potent and selective LSD1 inhibitor, effectively combats neuroendocrine prostate cancer by downregulating the ASCL1- dependent NE transcriptional program and re-expressing YAP1.

Targeted delivery of cytotoxic proteins to prostate cancer via conjugation to small molecule urea-based PSMA inhibitors.

Prostate cancer cells are characterized by a remarkably low proliferative rate and the production of high levels of prostate-specific proteases. Protein-based toxins are attractive candidates for prostate cancer therapy because they kill cells via proliferation-independent mechanisms. However, the non-specific cytotoxicity of these potent cytotoxins must be redirected to avoid toxicity to normal tissues. Prostate-Specific Membrane Antigen (PSMA) is membrane-bound carboxypeptidase that is highly expressed by prostate cancer cells. Potent dipeptide PSMA inhibitors have been developed that can selectively deliver and concentrate imaging agents within prostate cancer cells based on continuous PSMA internalization and endosomal cycling. On this basis, we conjugated a PSMA inhibitor to the apoptosis-inducing human protease Granzyme B and the potent Pseudomonas exotoxin protein toxin fragment, PE35. We assessed selective PSMA binding and entrance into tumor cell to induce cell death. We demonstrated these agents selectively bound to PSMA and became internalized. PSMA-targeted PE35 toxin was selectively toxic to PSMA producing cells in vitro. Intratumoral and intravenous administration of this toxin produced marked tumor killing of PSMA-producing xenografts with minimal host toxicity. These studies demonstrate that urea-based PSMA inhibitors represent a simpler, less expensive alternative to antibodies as a means to deliver cytotoxic proteins to prostate cancer cells.

Deletion of p53 in human mammary epithelial cells causes chromosomal instability and altered therapeutic response.

The TP53 tumor suppressor gene is the most commonly mutated gene in human cancers. To evaluate the biological and clinical relevance of p53 loss, human somatic cell gene targeting was used to delete the TP53 gene in the non-tumorigenic epithelial cell line, MCF-10A. In all four p53-/- clones generated, cells acquired the capability for epidermal growth factor-independent growth and were defective in appropriate downstream signaling and cell cycle checkpoints in response to DNA damage. Interestingly, p53 loss induced chromosomal instability leading to features of transformation and the selection of clones with varying phenotypes. For example, p53-deficient clones were heterogeneous in their capacity for anchorage-independent growth and invasion. In addition, and of clinical importance, the cohort of p53-null clones showed sensitivity to chemotherapeutic interventions that varied depending not only on the type of chemotherapeutic agent, but also on the treatment schedule. In conclusion, deletion of the TP53 gene from MCF-10A cells eliminated p53 functions, as well as produced p53-/- clones with varying phenotypes possibly stemming from the distinct chromosomal changes observed. Such a model system will be useful to further understand the cancer-specific phenotypic changes that accompany p53 loss, as well as help to provide future treatment strategies for human malignancies that harbor aberrant p53.

A fragment of the hypophosphatemic factor, MEPE, requires inducible cyclooxygenase-2 to exert potent anabolic effects on normal human marrow osteoblast precursors.

MEPE, 56.6 kDa protein isolated from tumors associated with hypophosphatemic osteomalacia, increases renal phosphate excretion and is expressed in normal human bone cells. AC-100, a central 23-amino acid fragment of MEPE, contains motifs that are important in regulating cellular activities in the bone microenvironment. Thus, we assessed in vitro effects of AC-100 on multipotential normal human marrow stromal (hMS) cells that have the capacity to differentiate into mature osteoblasts. Proliferation was quantified by [H3]thymidine uptake and cell counting and differentiation by the levels of mRNA for the alpha2-chain of type I procollagen (COL1A2), alkaline phosphatase (AP), and osteocalcin (OC) measured using real time reverse transcriptase PCR (RT-PCR) and by the formation of mineralized nodules. AC-100 increased proliferation by 257 +/- 89% (P < 0.005), increased gene expression of COL1A2 by 339 +/- 85% (P < 0.005), AP by 1,437 +/- 40% (P < 0.001), and OC by 1,962 +/- 337% (P < 0.001). In addition, it increased mineralized nodule formation by 81 +/- 14% (P < 0.001) in a dose- and time-dependent fashion. In equimolar dosages, the parent compound, MEPE, had the full activity of the AC-100 fragment. AC-100 elicited a comparable response to both IGF-I and BMP-2 with respect to proliferation and differentiation of hMS cells. Using gene expression microarray analysis, we demonstrated that AC-100 increased (by approximately 3-fold) the mRNA for cyclooxgenase-2 (COX-2), an inducible enzyme required for prostaglandin synthesis. Moreover, NS-398, a specific inhibitor of COX-2 action completely blocked AC-100-induced increases in proliferation and differentiation. Thus, AC-100 has potent anabolic activity on osteoblast precursor cells in vitro and these effects require the induction of COX-2.

Plasma pharmacokinetics and tissue distribution of 17-(allylamino)-17-demethoxygeldanamycin (NSC 330507) in CD2F1 mice1.

PURPOSE: 17-(Allylamino)-17-demethoxygeldanamycin (17AAG) is a benzoquinone ansamycin compound agent that has entered clinical trials. Studies were performed in mice to: (1) define the plasma pharmacokinetics, tissue distribution, and urinary excretion of 17AAG after i.v. delivery; (2) to define the bioavailability of 17AAG after i.p. and oral delivery; and (3) to characterize the concentrations of 17AAG metabolites in plasma and tissue. MATERIALS AND METHODS: All studies were performed in female CD2F1 mice. Preliminary toxicity studies used 17AAG i.v. bolus doses of 20, 40 and 60 mg/kg. Pharmacokinetic studies used i.v. 17AAG doses of 60, 40, and 26.67 mg/kg and i.p. and oral doses of 40 mg/kg. The plasma concentration versus time data were analyzed by compartmental and noncompartmental methods. The concentrations of 17AAG were also determined in brain, heart, lung, liver, kidney, spleen, skeletal muscle, and fat. Urinary drug excretion was calculated until 24 h after treatment. RESULTS: A 60 mg/kg dose of 17AAG, in its initial, microdispersed formulation, caused no changes in appearance, appetite, waste elimination, or survival of treated animals as compared to vehicle-treated controls. Bolus i.v. delivery of 60 mg/kg microdispersed 17AAG produced "peak" plasma 17AAG concentrations between 5.8 and 19.3 micrograms/ml in mice killed 5 min after injection. Sequential reduction of the 17AAG dose to 40 and 26.67 mg/kg resulted in "peak" plasma 17AAG concentrations between 8.9 and 19.0 micrograms/ml, and 4.8 and 6.1 micrograms/ml, respectively. Noncompartmental analysis of the plasma 17AAG concentration versus time data showed an increase in AUC from 402 to 625 and 1738 micrograms/ml.min when the 17AAG dose increased from 26.67 to 40 and 60 mg/kg, respectively. Across the range of doses studied, 17AAG total body clearance varied from 34 to 66 ml/min per kg. Compartmental modeling of the plasma 17AAG concentration versus time data showed that the data were fitted best by a two-compartment, open, linear model. In each study, substantial concentrations of a material, subsequently identified as 17-(amino)-17-demethoxygeldanamycin (17AG), were measured in plasma. A subsequent, lyophilized formulation of 17AAG proved excessively toxic when delivered i.v. at 60 mg/kg. A repeat i.v. study using a 40 mg/kg dose of this new formulation produced peak plasma 17AAG concentrations of 20.2-38.4 micrograms/ml, and a 17AAG AUC of 912 micrograms/ml.min, which was approximately 50% greater than the AUC produced by a 40 mg/kg dose of microdispersed 17AAG. The bioavailabilities of 17AAG after i.p. and oral delivery were 99% and 24%, respectively. Minimal amounts of 17AAG and 17AG were detected in the urine. After i.v. bolus delivery to mice, 17AAG distributed rapidly to all tissues, except the brain. Substantial concentrations of 17AG were measured in each tissue. CONCLUSIONS: 17AAG has excellent bioavailability when given i.p. but only modest bioavailability when given orally and is metabolized to 17AG and other metabolites when given i.v., i.p., or orally. 17AAG is widely distributed to tissues. These pharmacokinetic data generated have proven relevant to the design of recently initiated clinical trials of 17AAG and could be useful in their interpretation.

Phase I study of paclitaxel given by seven-week continuous infusion concurrent with radiation therapy for locally advanced squamous cell carcinoma of the head and neck.

PURPOSE: Paclitaxel is one of the most active agents for squamous cell carcinoma of the head and neck (SCCHN) and an in vitro radiosensitizer. The dose-response relationship for paclitaxel may depend more on exposure duration than on peak concentration. This National Cancer Institute-sponsored phase I trial was designed to determine the feasibility of combining continuous-infusion (CI) paclitaxel with concurrent radiation therapy (RT). PATIENTS AND METHODS: Patients with previously untreated stage IVA/B SCCHN were eligible. Primary end points were determination of the maximum-tolerated dose, dose-limiting toxicity, and pharmacokinetics for paclitaxel given by CI (24 hours a day, 7 days a week for 7 weeks) during RT (70 Gy/7 weeks). RESULTS: Twenty-seven patients were enrolled and assessable for toxicity. Nineteen of the patients who completed > or = 70 Gy were assessable for response. Grade 3 skin and mucosal acute reactions occurred at 10.5 mg/m(2)/d, but uninterrupted treatment was possible in five of six patients. At 17 mg/m(2)/d, skin toxicity required a 2-week treatment break for all three patients. The mean paclitaxel serum concentration at dose levels > or = 6.5 mg/m(2)/d exceeded that reported to achieve in vitro radiosensitization. Initial locoregional control was achieved in 14 (58%) of 24 of patients treated to 70 Gy, and control persisted in nine (38%). CONCLUSION: CI paclitaxel with concurrent RT is a feasible and tolerable regimen for patients with advanced SCCHN and good performance status. Preliminary response and survival data are encouraging and suggest that further study is indicated. The recommended phase II dose of paclitaxel by CI is 10.5 mg/m(2)/d with RT for SCCHN.

Femoral venous flow during laparoscopic gynecologic surgery.

The lower-limb venous return, assessed by the peak systolic venous velocities (PSVV) of the left common femoral vein, was recorded at different stages of operation for five patients undergoing major gynecologic operative laparoscopy. The average baseline PSVV was 23.1 cm/s. After positioning the patient in the Trendelenburg position, the PSVV increased to an average of 31.5 cm/s; this was a statistically significant increase. Creation of the pneumoperitoneum changed the waveform from a normal phasic pattern to a dampened, continuous, monophasic waveform. The average PSVV was reduced to 15.9 cm/s; this dampening was statistically significant. Further dampening was evident 1 hour intraoperatively, and the flow became intermittent, with cycles of dampened flow followed by periods of absent flow; these changes in PSVV were not statistically significant. Calf compressors did not increase the femoral PSVV at the beginning of operation, nor at I hour intraoperatively; the decrease was not statistically significant. After release of the pneumoperitoneum, the baseline waveform pattern and velocity returned. The Trendelenburg position used for gynecologic operative laparoscopy was associated with a statistically significant increase in the lower-limb PSVV. This increase did not fully counteract the dampening effect of a pneumoperitoneum on lower-limb PSVV. The authors' study did not support the benefit previously reported on the use of pneumatic calf compressors. The authors therefore recommend continuing the practice of antithrombotic measures for patients undergoing gynecologic operative laparoscopy.

The combination of insulin-like growth factor I and insulin-like growth factor-binding protein-3 reduces insulin requirements in insulin-dependent type 1 diabetes: evidence for in vivo biological activity.

Insulin-like growth factor-I (IGF-I) enhances insulin action in normal subjects and in patients with both type 1 and 2 diabetes; however, its administration is associated with significant side effects in a high percentage of patients. The coadministration of IGF binding protein-3 (IGFBP-3, the predominant IGF binding protein in serum) with IGF-I limits IGF-I inducible side effects, but it does not attenuate the ability of IGF-I to enhance protein synthesis and bone accretion; therefore, we determined whether IGF-I/IGFBP-3 would retain biological activity in type 1 DM and limit side effects associated with free IGF-I administration. Twelve patients received recombinant human IGF-I plus IGFBP-3 (2 mg/kg-day) by continuous sc infusion for 2 weeks. Each subject served as his own control; and, during a paired 2-week period, each received a placebo infusion. The order of the treatments was randomized. Subjects were placed on a constant caloric intake but were allowed to adjust insulin doses to maintain appropriate levels of glycemic control. Subjects measured blood glucose four times per day at home and kept a log of their insulin use. Frequent sampling for glucose, insulin, and GH was conducted during four inpatient study periods, one at the beginning and one at the end of each 2-week study interval. During IGF-I/IGFBP-3, insulin doses were reduced by 49%, and mean serum glucose was reduced by 23%. Free insulin levels obtained during frequent sampling in hospital fell 47% on IGF-I/IGFBP-3, compared with control, but showed no change with placebo. Concomitant glucose measurements did not differ in the two treatment groups. There was no change in body weight. Fructosamine levels decreased by 12%, but this was not significant (P < 0.1). Fasting triglyceride was unchanged, but cholesterol declined from 170 +/- 24 to 149 +/- 31 mg/dL (P < 0.05). IGFBP-2 (an IGF-I-dependent responsive variable) rose from 141 +/- 56 to 251 +/- 98 ng/mL (P < 0.01) on IGF-I/IGFBP-3. To analyze the mechanism by which IGF-I/IGFBP-3 might reduce insulin requirements, the change in serum GH was quantified. Mean GH levels were reduced by 72%, from 2.48 to 0.55 ng/mL (P < 0.001). An equal number (40%) of drug- and placebo-treated subjects had minor hypoglycemic episodes at home that required adjustment of insulin doses. No episode was classified as severe. In contrast to previous studies with free IGF-I, there were no cases of edema, headache, jaw pain, retinal edema, or Bell's palsy. No subject withdrew because of drug complications. These findings indicate that IGF-I/IGFBP-3 is biologically active on carbohydrate metabolism, as measured by a decrease in insulin requirements in patients with type 1 diabetes. Further studies will be required to determine the long-term safety and efficacy of this combination in patients with insulin resistance and diabetes.

Phase I study of paclitaxel in combination with a multidrug resistance modulator, PSC 833 (Valspodar), in refractory malignancies.

PURPOSE: To determine the maximum-tolerated dose (MTD), dose-limiting toxicity (DLT), and pharmacokinetics of paclitaxel when given with PSC 833 (valspodar) to patients with refractory solid tumors. PATIENTS AND METHODS: Patients were initially treated with paclitaxel 175 mg/m(2) continuous intravenous infusion (CIVI) over 3 hours. Subsequently, 29 hours of treatment with CIVI PSC 833 was started 2 hours before paclitaxel treatment was initiated. In this combination, the starting dose of paclitaxel was 52.5 mg/m(2). Paclitaxel doses were escalated by 17.5 mg/m(2) increments for four subsequent cohorts. Each cohort consisted of three patients with the exception of the last cohort, which consisted of six patients. Data for the pharmacokinetics of paclitaxel with and without concurrent PSC 833 administration were obtained. RESULTS: All 18 patients completed at least one course of concurrent treatment (median, two courses; range, one to six) and were evaluable for toxicity. The MTD for paclitaxel with PSC 833 was 122.5 mg/m(2). Neutropenia was the DLT. All patients had PSC 833 blood concentrations greater than 1, 000 ng/mL before, during, and 24 hours after the paclitaxel infusion. PSC 833 produced small increases in the paclitaxel peak plasma concentrations and areas under the concentration-time curve. However, PSC 833 greatly prolonged the terminal phase of paclitaxel, resulting in plasma paclitaxel concentrations of more than 0.05 micromol/L for much longer than expected. As a result, myelosuppression was comparable to that produced by full-dose paclitaxel given without PSC 833. Of the 16 patients who were assessable for response, one patient experienced a partial response and an additional nine patients experienced disease stabilization after paclitaxel treatment alone. CONCLUSION: Treatment with paclitaxel 122.5 mg/m(2) as a 3-hour CIVI concurrent with a 29-hour CIVI of PSC 833 results in acceptable toxicity. The addition of PSC 833 alters the pharmacokinetics of paclitaxel, which explains the enhanced neutropenia experienced by patients treated with this drug combination.

Antitumor activity, distribution, and metabolism of 13-cis-retinoic acid as a single agent or in combination with tamoxifen in established human MCF-7 xenografts in mice.

PURPOSE: The efficacy of 13-cis-retinoic acid (13-CRA) given as a single agent or in combination with tamoxifen (TAM) was determined in athymic nude mice bearing advanced s.c. MCF-7 human breast cancers. METHODS: 13-CRA alone was given by gavage at doses ranging from 26.4 to 200 mg/kg. TAM alone was given by gavage at doses of 7.5, 15, 30, or 60 mg/kg. For combination studies, each dose of TAM was followed 4 h later by 13-CRA at doses of 25, 50, 100, or 200 mg/kg. All treatments began on day 12 and were continued for 3 weeks. RESULTS: The median time to two doublings recorded for the control and for 13-CRA and TAM given as single agents at the highest dose were 22.2, 29.2, and 54.7 days, respectively. In combination, 100 and 200 mg/kg 13-CRA with 7.5 mg/kg TAM resulted in a delay in tumor growth at least as high as that achieved with highest-dose TAM alone, but the effect was not synergistic. Pharmacokinetic analysis of 13-CRA was performed in plasma, liver, and tumor from mice bearing 0.5- to 2.0 g carcinomas following a single dose of 100 mg/kg 13-CRA. Results showed that 13-CRA was metabolized differently in various tissues, but concentrations of 13-CRA detected in tumor were in the range reported to be active in vitro. all-trans-Retinoic acid (ATRA) concentrations were about 5% of the 13-CRA concentrations detected in plasma, 68% of those found in liver, and 20% of those found in tumor. 4-oxo-CRA represented between 2% and 10% of 13-CRA concentrations detected in plasma and liver but was not detected in tumor. Furthermore there was no difference in peak plasma 13-CRA concentrations found in the same tissues at 30 min after a single dose or after the eighth dose of 100 mg/kg 13-CRA or 13-CRA and TAM. Mean 13-CRA concentrations detected in liver and tumor were 50-90% and 16-30% of plasma peak concentrations, respectively. No difference in 4-oxo-CRA concentration was observed between the treatment groups. CONCLUSIONS: These data suggest that 13-CRA is not effective against established human breast tumor xenografts despite the stability of the pharmacokinetics of 13-CRA and the generation of ATRA as a metabolite. The addition of 13-CRA to TAM did not improve the efficacy of TAM against these estrogen-receptor-positive xenografts.

Home within 24 hours of laparoscopic hysterectomy.

We assessed the feasibility of safe discharge home within 24 hours following laparoscopic hysterectomy in 30 patients who met the inclusion criteria and consented to be enrolled in the study group. Patients were admitted on the day of their surgery with the expectation of discharge within 24 hours. Appropriate home nursing follow-up and phone contact by the surgical team were organized preoperatively. Inclusion criteria were: age 30-65 years, absence of any major medical history that would require prolonged hospitalization, availability of home support for the first 48 hours after discharge and presence of a working telephone line and an address within the area of the Community Home Nursing service. All 30 operative procedures were completed without incident. Six patients underwent total laparoscopic hysterectomy (TLH) (all the procedures of hysterectomy being performed laparoscopically including the suturing of uterine arteries, colpotomy and closure of the vaginal vault. The uterus was removed vaginally) and 24 patients underwent laparoscopic hysterectomy (LH) (this techniques differs from TLH in that the colpotomy was performed laparoscopically but the uterosacral ligaments were divided vaginally and the vault also was closed vaginally after the uterus was removed vaginally). The average operating time was 115 minutes (range 85-150 minutes) and the average blood loss was 97 mL (20-250 mL). There were no intraoperative complications, no requirement for transfusion and no readmission to hospital for any of the patients in the study. Postoperative complications were minor (umbilical cellulitis (1), intestinal colic (1)) and both were treated with resolution of the symptoms. Ninety per cent of patients in the study were discharged within 24 hours of their surgery, the average duration of stay being 22.9 hours (20-24 hours). Three patients were not fit for discharge at 24 hours postoperatively due to general lethargy, migraine and nausea; their average discharge time was 53.5 hours. The study showed that laparoscopic hysterectomy can be associated with a reduction in length of in-patient stay compared to traditional laparotomy. Furthermore this reduction could be safely reduced to 24 hours following laparoscopic hysterectomy. There was also an associated cost saving in terms of inpatient bed days. Patient satisfaction with this protocol was high in this selected and motivated group.

Metabolism of 17-(allylamino)-17-demethoxygeldanamycin (NSC 330507) by murine and human hepatic preparations.

17-(Allylamino)-17-demethoxygeldanamycin (17AAG), a compound that is proposed for clinical development, shares the ability of geldanamycin to bind to heat shock protein 90 and GRP94, thereby depleting cells of p185erbB2, mutant p53, and Raf-1. Urine and plasma from mice treated i.v. with 17AAG contained six materials with absorption spectra similar to that of 17AAG. Therefore, in vitro metabolism of 17AAG by mouse and human hepatic preparations was studied to characterize: (a) the enzymes responsible for 17AAG metabolism; and (b) the structures of the metabolites produced. These materials had retention times on high-performance liquid chromatography of approximately 2, 4, 5, 6, 7, and 9 min. When incubated in an aerobic environment with 17AAG, murine hepatic supernatant (9000 x g) produced each of these compounds; the 4-min metabolite was the major product. This metabolism required an electron donor, and NADPH was favored over NADH. Metabolic activity resided predominantly in the microsomal fraction. Metabolism was decreased by approximately 80% in anaerobic conditions and was essentially ablated by CO. Microsomes prepared from human livers produced essentially the same metabolites as produced by murine hepatic microsomes, but the 2-min metabolite was the major product, and the 4-min metabolite was next largest. There was no metabolism of 17AAG by human liver cytosol. Metabolism of 17AAG by human liver microsomes also required an electron donor, with NADPH being preferred over NADH, was inhibited by approximately 80% under anaerobic conditions, and was essentially ablated by CO. Liquid chromatography/mass spectrometry analysis of human and mouse in vitro reaction mixtures indicated the presence of materials with molecular weights of 545, 601, and 619, compatible with 17-(amino)-17-demethoxygeldanamycin (17AG), an epoxide, and a diol, respectively. The metabolite with retention time of 4 min was identified as 17AG by cochromatography and mass spectral concordance with authentic standard. Human microsomal metabolism of 17AAG was inhibited by ketoconazole, implying 3A4 as the responsible cytochrome P450 isoform. Incubation of 17AAG with cloned CYP3A4 produced metabolites 4 and 6. Incubation of 17AAG with cloned CYP3A4 and cloned microsomal epoxide hydrolase produced metabolites 2 and 4, with greatly decreased amounts of metabolite 6. Incubation of 17AAG with human hepatic microsomes and cyclohexene oxide, a known inhibitor of microsomal epoxide hydrolase, did not affect the production of metabolite 4 but decreased the production of metabolite 2 while increasing the production of metabolite 6. These data imply that metabolite 2 is a diol and metabolite 6 is an epoxide. Mass spectral fragmentation patterns and the fact that 17AG is not metabolized argue for the epoxide and diol being formed on the 17-allylamino portion of 17AAG and not on its ansamycin ring. These data have implications with regard to preclinical toxicology and activity testing of 17AAG as well as its proposed clinical development because: (a) production of 17AG requires concomitant production of acrolein from the cleaved allyl moiety; and (b) 17AG, which was not metabolized by microsomes, has been described as being as active as 17AAG in decreasing cellular p185erbB2.

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

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

The safety of laparoscopic treatment for ovarian dermoid tumours.

Whilst laparoscopic surgery has largely replaced laparotomy as the standard surgical option for the management of benign ovarian cysts, concern remains regarding the safety of laparoscopy for benign cystic teratomas. This is based on a higher rate of cyst content spillage compared to laparotomy and the known sequelae of chemical peritonitis and granuloma formation. We present 18 cases of laparoscopic dermoid cystectomy with recommendations for specimen removal from the peritoneal cavity. Our findings together with evidence from the literature confirms the safety of laparoscopy for the treatment of ovarian dermoid cysts.

Methods of creating pneumoperitoneum: a review of techniques and complications.

The existence of numerous techniques for the creation of pneumoperitoneum at laparoscopy indicates that none have been proven totally efficacious or complication free. These methods include the standard technique of insufflation after insertion of the Veress needle via the umbilicus or less commonly via the transfundal or transforniceal routes, open laparoscopy involving dissection through the linea alba and opening of the peritoneum under direct vision, and direct trocar insertion as well as variations on these techniques. After reviewing the methods available and surveying the existing data concerning the rates of failure and complications, we conclude that no single technique can claim to be overwhelmingly superior, and that laparoscopists should, therefore, acquaint themselves with at least two of these techniques. Finally, we recommend a large-scale combined survey by the colleges of obstetricians and gynecologists and surgeons on rates of failure and complications of the varied approaches of abdominal entry for laparoscopy.

Plasma concentrations and pharmacokinetics of dimethylsulfoxide and its metabolites in patients undergoing peripheral-blood stem-cell transplants.

PURPOSE: Dimethylsulfoxide (DMSO) is used to cryopreserve hematopoietic stem cells and is obligatorily infused into patients who receive stem-cell transplants. This study characterized the plasma concentrations and pharmacokinetics of DMSO and its metabolites in patients who underwent peripheral-blood stem-cell transplants. MATERIALS AND METHODS: Plasma concentrations of DMSO, dimethylsulfone (DMSO2), and dimethylsulfide (DMSH2) were assessed in 10 patients who underwent autologous transplants with stem cells, cryopreserved in 10% DMSO (vol/vol). Blood was sampled at multiple times after the stem-cell infusion. Urine was pooled during the 24 hours postinfusion. DMSO, DMSO2, and DMSH2 were assayed simultaneously by gas chromatography. A one-compartment model with saturable elimination proved most suitable for fitting plasma DMSO concentration-versus-time data. RESULTS: Stem-cell volumes infused ranged between 180 and 585 mL (254 to 824 mmol DMSO). Infusions lasted between 20 and 120 minutes. Peak plasma DMSO concentrations were 19.1 +/- 6.3 mmol/L (mean +/- SD). Pharmacokinetic parameters for volume of the central compartment (Vc), maximum velocity (Vmax), and Michaels-Menten constant (Km) were 37.3 +/- 17 L, 0.99 +/- 0.57 mmol/L/h, and 5.2 +/- 5.0 mmol/L, respectively. Plasma DMSO2 concentrations increased during the first 24 hours, plateaued at 4.4 +/- 1.2 mmol/L, and remained there until 48 hours (the last sample). DMSH2 concentrations were at steady-state by 5 minutes and remained between 3 and 5 mmol/L for 48 hours. Urinary excretion of DMSO and DMSO2 accounted for 44% +/- 4% and 4% +/- 1%, respectively, of the administered DMSO dose. Renal clearance of DMSO was 14.1 +/- 3.4 mL/min. CONCLUSION: These data (1) document plasma concentrations of DMSO and metabolites in patients following peripheral-blood stem-cell transplants; (2) allow consideration of potential effects of these concentrations on stem-cell engraftment and drug-drug interactions; and (3) can facilitate a concentration-guided phase I trial of DMSO.

Analgesia following major gynecological laparoscopic surgery--PCA versus intermittent intramuscular injection.

BACKGROUND AND OBJECTIVES: To compare the use of patient-controlled analgesia to intermittent intramuscular injections of morphine following major gynecological laparoscopic procedures in order to assess differences in level of pain, sedation, episodes of nausea and/or vomiting, hospitalization time and patient satisfaction with their postoperative analgesia. METHODS: Seventy-two patients undergoing major gynecological laparoscopic surgery were randomized to receive either postoperative analgesia via intermittent intramuscular injection of morphine (Group 1) or patient controlled analgesia (PCA-Group 2). All patients received anesthesia via a standardized protocol. Postoperative pain levels were recorded via a 10 cm visual analogue scale, and sedation scores were recorded on a standard PCA form. Episodes of nausea and vomiting were also recorded on the same form. RESULTS: There were no statistically significant differences between intramuscular analgesia and PCA for any of the factors studied. Most significantly it was found that most patients ceased to require either form of parenteral analgesia within 24 hours of their procedure, regardless of the operating time. CONCLUSION: It is important for the surgeon to be aware of the effects of postoperative analgesia on his or her patients' level of satisfaction. We do not recommend the use of PCA analgesia following major laparoscopic gynecological surgery.

Vault haematoma following laparoscopic hysterectomy.

Thirty consecutive patients underwent transabdominal ultrasound scanning on day 2 postoperatively in order to provide data on the incidence of vaginal vault haematoma following laparoscopic hysterectomy. Details of postoperative morbidity, both inpatient and after discharge, were recorded. Results support the view that there is no significant association between the presence of vaginal vault haematoma (73%) and the incidence of posthysterectomy febrile morbidity (16.7%). Furthermore the incidence of vault haematoma after laparoscopic hysterectomy is comparable to literature figures for both abdominal and vaginal hysterectomy, whilst that of febrile morbidity is at least equivalent if not reduced for the laparoscopic approach. We believe this provides further evidence confirming the safety of the laparoscopic approach to hysterectomy.

Skin closure at laparoscopy.

STUDY OBJECTIVE: To discern the best method of wound closure after laparoscopy based on patient acceptability of pain, complications, and cosmetic result. DESIGN: Randomized, prospective study. SETTING: A university-affiliated hospital. PATIENTS: Fifty-four women. Interventions. The women received interrupted 3-0 nylon sutures, subcuticular 3-0 polyglactin 910 sutures, or adhesive strips for skin closure. At the umbilical port site the rectus sheath was closed with a single 0 polyglactin suture and then one of the three materials for skin closure. The lateral ports were closed with a combination of these materials, allowing each patient to act as her own control. MEASUREMENTS AND MAIN RESULTS: Pain was significantly less in wounds closed by subcuticular technique than in those closed by either transcutaneous suture or adhesive strips. This was seen for the 5-mm, 10-mm, and umbilical port sites. There was no statistically significant difference in the rate of reported complications or patient satisfaction between subcuticular and transcutaneous wound sites. CONCLUSION: We believe these results support subcuticular methods of wound closure after laparoscopic procedures.