A Phase 1, Dose-Ranging Study to Assess Safety and Psychoactive Effects of a Vaporized 5-Methoxy-N,N-Dimethyltryptamine Formulation (GH001) in Healthy Volunteers

Introduction

5-Methoxy-N,N-Dimethyltryptamine (5-MeO-DMT) is a tryptamine with ultra-rapid onset and short duration of psychedelic effects. Prospective studies for other tryptamines have suggested beneficial effects on mental health outcomes.

Objectives

In preparation for a study in patients with depression, the present study GH001-HV-101 aimed to assess the impact of four different dose levels of a novel vaporized 5-MeO-DMT formulation (GH001) administered via inhalation as single doses, and in an individualized dose escalation regimen on the safety, tolerability, and the dose-related psychoactive effects in healthy volunteers (n=22). Further, we aimed to assess the impact on cognitive functioning, mood, and well-being.

Methods

The psychedelic experience was assessed with a novel Peak Experience Scale (PES), the Mystical Experience Questionnaire (MEQ), the Ego Dissolution Inventory (EDI), the Challenging Experience Questionnaire (CEQ), and the 5-Dimensional Altered States of Consciousness Questionnaire (5D-ASC).

Results

5-MeO-DMT produced dose-related increments in the intensity of the psychedelic experience ratings on all questionnaires, except the CEQ. Prominent effects were observed following single doses of 6, 12, and 18 mg on PES and MEQ ratings, while maximal effects on PES, MEQ, EDI, and 5D-ASC ratings were observed following individualized dose escalation of 5-MeO-DMT. Measures of cognition, mood, and well-being were not affected. Vital signs at 1 and 3 h after administration were not affected and adverse events were generally mild and resolved spontaneously.

Conclusions

Individualized dose escalation of 5-MeO-DMT may be preferable over single dose administration for clinical applications that aim to enhance the short-term psychoactive effects to elicit a strong therapeutic response.

Disclosure

This study was funded by GH Research PLC, Dublin, Ireland.

Measurement of direct CP violation parameters in B± → J/ψK± and B± → J/ψπ± decays with 10.4 fb-1 of Tevatron data

We present a measurement of the direct CP-violating charge asymmetry in B(±) mesons decaying to J/ψK(±) and J/ψπ(±) where J/ψ decays to μ(+) μ(-), using the full run II data set of 10.4 fb(-1) of proton-antiproton collisions collected using the D0 detector at the Fermilab Tevatron Collider. A difference in the yield of B(-) and B(+) mesons in these decays is found by fitting to the difference between their reconstructed invariant mass distributions resulting in asymmetries of A(J/ψK) = [0.59 ± 0.37]%, which is the most precise measurement to date, and A(J/ψπ) = [-4.2 ± 4.5]%. Both measurements are consistent with standard model predictions.

Effect of growth induced (non)stoichiometry on interfacial conductance in LaAlO3/SrTiO3

We demonstrate a link between the growth process, the stoichiometry of LaAlO(3), and the interfacial electrical properties of LaAlO(3)/SrTiO(3) heterointerfaces. Varying the relative La:Al cation stoichiometry by a few atomic percent in films grown at 1×10(-3) Torr results in a 2 and 7 order-of-magnitude change in the 300 and 2 K sheet resistance, respectively, with highly conducting states occurring only in La-deficient or Al-excess films. Further reducing the growth pressure results in an increase of the carrier density and a dramatic change in mobility. We discuss the relative contributions of intrinsic and extrinsic effects in controlling the physical properties of this widely studied system.

A management algorithm for congenital erythropoietic porphyria derived from a study of 29 cases

BACKGROUND

Congenital erythropoietic porphyria (CEP) is an autosomal recessive photomutilating porphyria with onset usually in childhood, where haematological complications determine prognosis. Due to its extreme rarity and clinical heterogeneity, management decisions in CEP are often difficult.

OBJECTIVES

To develop a management algorithm for patients with CEP based on data from carefully characterized historical cases.

METHODS

A single investigator collated data related to treatments and their outcomes in 29 patients with CEP from the U.K., France, Germany and Switzerland.

RESULTS

Six children were treated with bone marrow transplantation (BMT); five have remained symptomatically cured up to 11.5 years post-transplantation. Treatments such as oral charcoal, splenectomy and chronic hypertransfusion were either of no benefit or were associated with complications and negative impact on health-related quality of life. Lack of consistent genotype-phenotype correlation meant that this could not be used to predict disease prognosis. The main poor prognostic factors were early age of disease onset and severity of haematological manifestations.

CONCLUSIONS

A management algorithm is proposed where every patient, irrespective of disease severity at presentation, should receive a comprehensive, multidisciplinary clinical assessment and should then be reviewed at intervals based on their predicted prognosis, and the rate of onset of complications. A BMT should be considered in those with progressive, symptomatic haemolytic anaemia and/or thrombocytopenia. Uroporphyrinogen III synthase genotypes associated with poor prognosis would additionally justify consideration for a BMT. Rigorous photoprotection of the skin and eyes from visible light is essential in all patients.

Incidence and risk factors for hip or other bone fractures among hemodialysis patients in the Dialysis Outcomes and Practice Patterns Study

The available data on bone fractures in hemodialysis (HD) patients are limited to results of a few studies of subgroups of patients in the United States. This study describes the prevalence of hip fractures and the incidence and risk factors associated with hip and other fractures in representative groups of HD facilities (n=320) and patients (n=12 782) from the 12 countries in the second phase of the Dialysis Outcomes and Practice Patterns Study (2002-2004). Among prevalent patients, 2.6% had a prior hip fracture. The incidence of fractures was 8.9 per 1000 patient years for new hip fractures and 25.6 per 1000 for any new fracture. Older age (relative risk (RR)(HIP)=1.91, RR(ANY)=1.33, P<0.0001), female sex (RR(HIP)=1.41, P=0.02; RR(ANY)=1.59, P<0.0001), prior kidney transplant (RR(HIP)=2.35, P=0.04; RR(ANY)=1.76, P=0.007), and low serum albumin (RR(HIP)=1.85, RR(ANY)=1.45, per 1 g/dl lower, P<0.0001) were predictive of new fractures. Elevated risk of new hip fracture was observed for selective serotonin reuptake inhibitors and combination narcotic medications (RR=1.63, RR=1.74, respectively, P<0.05). Several medications were associated with risk of any new fracture: narcotic pain medications (RR=1.67, P=0.02), benzodiazepines (RR=1.31, P=0.03), adrenal cortical steroids (RR=1.40, P<0.05), and combination narcotic medications (RR=1.72, P=0.001). Parathyroid hormone (PTH) levels >900 pg/ml were associated with an elevated risk of any new fracture (RR=1.72, P<0.05) versus PTH 150-300. The results suggest that greater selectivity in prescribing several classes of psychoactive drugs and more efficient treatment of secondary hyperparathyroidism may help reduce the burden of fractures in HD patients.

Gate-defined quantum dots on carbon nanotubes

We report the realization of nanotube-based multiple quantum dots that are fully defined and controlled with electrostatic gates. Metallic top-gates are used to produce localized depletion regions in the underlying tubes; a pair of such depletion regions in a nanotube with ohmic contact electrodes defines the quantum dot. Top-gate voltages tune the transparencies of tunnel barriers as well as the electrostatic energies within single and multiple dots. This approach allows precise control over multiple devices on a single tube, and serves as a design paradigm for nanotube-based electronics and quantum systems.

Anomalous conductance quantization in carbon nanotubes

Conductance measurements of carbon nanotubes containing gated local depletion regions exhibit plateaus as a function of gate voltage, spaced by approximately 1e(2)/h, the quantum of conductance for a single (nondegenerate) mode. Plateau structure is investigated as a function of bias voltage, temperature, and magnetic field. We speculate on the origin of this surprising quantization, which appears to lack band and spin degeneracy.

Local Gate Control of a Carbon Nanotube Double Quantum Dot

We have measured carbon nanotube quantum dots with multiple electrostatic gates and used the resulting enhanced control to investigate a nanotube double quantum dot. Transport measurements reveal honeycomb charge stability diagrams as a function of two nearly independent gate voltages. The device can be tuned from weak to strong interdot tunnel-coupling regimes, and the transparency of the leads can be controlled independently. We extract values of energy-level spacings, capacitances, and interaction energies for this system. This ability to control electron interactions in the quantum regime in a molecular conductor is important for applications such as quantum computation.

Pattern of malignant lymphoma in the United Arab Emirates--a histopathologic and immunologic study in 208 native patients

The aim of this study was to analyze the distribution of the various pathologic types of lymphoma in a native Arab population of the United Arab Emirates (UAE). Two hundred and eight patients with malignant lymphoma diagnosed over a 12-year period (1988-1999) were retrospectively studied morphologically and immunohistochemically with a panel of monoclonal antibodies and classified according to the revised European-American classification of lymphoid neoplasms (REAL). Of the 208 patients in the study, 41% had Hodgkin's disease (HD) and 59% had non-Hodgkin's lymphoma (NHL). The distribution of HD showed a predominance of nodular sclerosis and mixed cellularity types. Among NHLs, the most frequent type was diffuse large B cell (59% of all NHLs) followed by the Burkitt's type (13%). The proportion of primary extranodal NHL was 29%. Immunologically, the percentages of NHL with B-cell and T-cell phenotypes were 83 and 11, respectively. When the International Working Formulation was used, 34% of NHLs were classified as high grade, 59% as intermediate grade and only 7% as low-grade lymphomas.

Evidence of progesterone receptors in the mucosa of the urinary bladder

OBJECTIVE

To investigate whether progesterone receptors are present in the mucosa of the urinary bladder of continent premenopausal women compared with continent postmenopausal women.

MATERIALS AND METHODS

Fifty-seven biopsies from the mucosa of the trigone and lateral wall of the urinary bladder were examined by the avidin-biotin-peroxidase immunohistochemical technique for the presence of estrogen and progesterone receptors. The specimens were obtained at cystoscopy performed to investigate hematuria in 42 patients and neoplasia in 15. The study group (n = 29) comprised non-pregnant premenopausal women in the luteal phase of their menstrual cycle and the control group (n = 28) comprised postmenopausal women. None of the subjects had urinary incontinence or was taking medication with hormones. In no case did the primary lesion involve the specimen used for laboratory analysis.

RESULTS

There was positive immunostaining with estrogen in 28 patients of the study group (96.5%) and 4 (14.4%) in the control group (p<0.0001). The 28 samples of the study group also showed positive immunostaining for progesterone receptors. There was positive immunostaining with progesterone in 18 samples (64.3%) of the control group (p<0.01). Fourteen samples (50%) of the control group thus showed positive immunostaining for progesterone but no evidence of positive immunostaining with estrogen. Immunostaining for estrogen and progesterone receptors was similar in trigonal and lateral wall samples.

CONCLUSION

In continent pre- and post-menopausal women, a direct progestogenic effect on the mucosa of the urinary bladder seems likely in addition to estrogen.

Photodynamic therapy in the canine prostate using motexafin lutetium

Our purpose was to determine the feasibility of comprehensive treatment of the canine prostate with photodynamic therapy (PDT) using motexafin lutetium (Lu-Tex) and to evaluate the toxicity and tissue effects associated with this treatment. Twenty-five adult male beagles with normal prostate glands were given an i.v. injection of the second-generation photosensitizer Lu-Tex (2-6 mg/kg). An additional two dogs were used as controls and did not receive any photosensitizing drug. All 27 dogs underwent laparotomy to expose the prostate. Three hours postinjection, a total dose of 75-150 J/cm of 732 nm laser light was delivered interstitially and/or transurethrally to the prostate via cylindrical diffusing fibers. Dogs were euthanized between 2 days and 3 months after PDT. All subjects were monitored for clinical evidence of toxicity. Specimens were examined macroscopically and microscopically to characterize the tissue reaction and assess extent of tissue effect as a result of treatment. Interstitial and/or transurethral PDT were successfully delivered in all dogs with no perioperative complications. No clinical evidence of acute urinary obstruction or rectal bleeding was noted. At all dose levels, macroscopic and microscopic evaluation revealed a prostatic tissue reaction characterized initially (within 48 h) by inflammation and necrosis followed by fibrosis and glandular epithelial atrophy. Comprehensive treatment of the entire prostate could be achieved using the interstitial alone approach or combined transurethral and interstitial approach. The transurethral alone approach did not result in complete coverage of the prostate. Dogs receiving transurethral or combined interstitial and transurethral treatment developed erythema and urethral epithelial disruption at all dose levels. Those receiving combined treatment at the highest dose level (Lu-Tex 6 mg/kg, 150 J/cm light) developed urethral fistulae and peritonitis. Dogs treated with the interstitial alone approach were found to have the least amount of urethral damage. Comprehensive treatment of the canine prostate with Lu-Tex PDT is feasible using an interstitial alone or combined interstitial and transurethral approach. The interstitial alone technique results in the least amount of toxicity. The prostatic tissue reaction to treatment is characterized by initial inflammation and necrosis followed by fibrosis and glandular epithelial atrophy.

Intrathecal sufentanil and morphine for post-thoracotomy pain relief

In this double-blind randomized study we compared a group of 15 patients undergoing thoracotomy who received a spinal injection of sufentanil 20 microg combined with morphine (200 microg) after induction of general anaesthesia with a control group of the same size. Post-operative pain was rated on a visual analogue scale (VAS) and a verbal rating scale at rest and with a VAS on coughing. In the recovery room, patients received titrated i.v. morphine until the VAS score was <30, and were followed by patient-controlled analgesia (PCA) for 72 h. The intrathecal sufentanil and morphine group had a lower intra-operative requirement for i.v. sufentanil and needed less i.v. morphine for titration in the recovery room. I.v. PCA morphine consumption and pain scores were lower in the active group than in the control group during the first 24 h. There were no differences after this time. Spirometric data (peak expiratory flow, forced vital capacity and forced expiratory volume in 1 s) were similar in the two groups. We conclude that the combination of intrathecal sufentanil and morphine produces analgesia of rapid onset and with a duration of 24 h.

Elongation arrest is a physiologically important function of signal recognition particle

Signal recognition particle (SRP) targets proteins for co-translational insertion through or into the endoplasmic reticulum membrane. Mammalian SRP slows nascent chain elongation by the ribosome during targeting in vitro. This 'elongation arrest' activity requires the SRP9/14 subunit of the particle and interactions of the C-terminus of SRP14. We have purified SRP from Saccharomyces cerevisiae and demonstrated that it too has elongation arrest activity. A yeast SRP containing Srp14p truncated at its C-terminus (delta C29) did not maintain elongation arrest, was substantially deficient in promoting translocation and interfered with targeting by wild-type SRP. In vivo, this mutation conferred a constitutive defect in the coupling of protein translation and translocation and temperature-sensitive growth, but only a slight defect in protein translocation. In combination, these data indicate that the primary defect in SRP delta C29 is in elongation arrest, and that this is a physiologically important and conserved function of eukaryotic SRP.

Intestinal helminths of spiny mice (Acomys cahirinus dimidiatus) from St Katherine's Protectorate in the Sinai, Egypt

Spiny mice, Acomys cahirinus dimidiatus, inhabiting the wadis close to St Katherine in the mountains of the Sinai peninsula, were trapped and their helminth parasites were studied. Sixty one mice provided faeces for analysis and 27 were killed and autopsied. Six species of helminths were recorded (the spirurid nematodes, Protospirura muricola (74.1%) and Mastophorus muris (11.1%), the oxyuroid nematodes, Dentostomella kuntzi (59.3%), Aspiculuris africana (3.7%), and Syphacia minuta (3.7%) and the hymenolepidid cestode Rodentolepis negevi (18.5%)). The spirurids were the dominant species present, accounting for up to 0.87% of total host body weight. Analysis of worm weights and lengths suggested that transmission had been taking place in the months preceding our study. No sex difference in the prevalence or abundance of spirurids was detected. Significant differences were identified in the abundance of total nematode burdens and the mean helminth species richness between the three wadis which provided multiple captures of mice. There was also a marked effect of host age on both parameters. A highly significant positive correlation between spirurid egg counts and total worm biomass indicated that non-invasive techniques based on egg counts could be used to quantify worm burdens and when this technique was applied to a larger sample size (n = 61), a significant difference between sites but no host sex or age effects were detected for spirurid faecal egg counts. The data suggest that there are differences between helminth component communities infecting spiny mice in different neighbouring wadis, a hypothesis which will be explored further through our continuing studies in the Sinai.

Non-evidence of estrogen receptors in the rectal mucosa

The aim of the study was to investigate whether estrogen receptors are present in the rectal mucosa of premenopausal women compared to postmenopausal women and men. Thirty biopsies obtained from the rectal mucosa at colonoscopy, performed to investigate inflammatory bowel disease in 23 patients and neoplasia in 7, were examined by the avidin-biotin-peroxidase immunohistochemical technique for the presence of estrogen receptors. The study group (n = 10) were non-pregnant premenopausal women and the control group (n = 20) were postmenopausal women (n = 10) and men (n = 10). None of the subjects had fecal incontinence or was taking medication with hormones. In no case did the primary lesion involve the specimen used for laboratory analysis. All samples showed negative immunostaining for estrogen receptors. It was concluded that in continent women and men, a direct estrogenic effect on the rectal mucosa seems unlikely.

Assessment of pelvic stabilization devices for improved field reproducibility

The aim of this study was to evaluate the improvement in patient comfort and field positional accuracy provided by a new pelvic stabilization system when delivering multiple field radiotherapy to the pelvis. The Pelvic Cradle (BEHTS Manufacturing, Brisbane, Qld, Australia) is a stabilization device that provides reproducible patient positioning and levelling. Ninety patients were randomized into three groups. The first group was treated using the Pelvic Cradle, the second group was treated using current stabilization practices, and the third group was treated using the Pron Pillo (Chattanooga Pharmacal Company, USA) and current stabilization practices. Port films were assessed for field displacement in the lateral and cranio-caudal directions. A patient survey was used to evaluate the patient's perception of comfort while receiving treatment. When compared to the control group, the pelvic cradle group demonstrated a 48% improvement in the mean lateral deviation from 3.8 mm to 2.0 mm (P < 0.001) and a 36% improvement in the mean cranio-caudal deviation from 3.9 mm to 2.5 mm (P < 0.001). The Pelvic Cradle was found to provide an improved level of field positional accuracy while maintaining patient comfort.

Sera from habitual aborters induce monocyte procoagulant activity: a lymphocyte-dependent event

Placental thrombosis is a prominent feature in patients with unexplained recurrent fetal loss. To determine whether induction of monocyte procoagulant activity might be a relevant mechanism for unexplained recurrent fetal loss, peripheral blood mononuclear cells isolated from normal healthy controls were cocultured with (a) sera from normal healthy controls (n = 16), (b) sera from habitual aborters (n = 41), and (c) lipopolysaccharide as a positive control. Sera from three patients were fractionated on Sephracryl S-300 and the inducing molecule(s) characterized. Sera from normal healthy controls failed to induce procoagulant activity above basal levels of 21 +/- 4.6 mU/10(5) peripheral blood mononuclear cells. Of the sera from 41 habitual aborters examined 26 (63%) induced procoagulant to a mean value of 410 +/- 48 mU/10(5) peripheral blood mononuclear cells (P < 0.01). Sera from 15 patients failed to augment procoagulant activity. The induction of procoagulant activity was maximal after 6 hr of incubation and was lymphocyte dependent. Fractionation of serum from the three patients on Sepharcryl S300 revealed the procoagulant activity (PCA)-inducing factor(s) to have a molecular weight of between 300,000 and 800,000 Da. The serum factor was found to be heat, alkaline, and acid sensitive. Both anti-IgM and anti-IgA immunoabsorbents reduced the PCA-inducing factor. We conclude that IgM and IgA from some patients with unexplained recurrent fetal loss are capable of inducing procoagulant activity and could contribute to the development of placental microthrombi and infarction, prominent features of this syndrome.

Ancrod improves survival in murine systemic lupus erythematosus

The effect of ancrod, a defibrinating agent, on murine lupus glomerulonephritis in the male BXSB mouse was studied to determine the relationship between macrophage procoagulant activity (PCA), fibrin deposition and glomerulonephritis. Marked renal disease and fibrin deposition were noted by three months of age in control mice, whereas little or no disease was seen in ancrod treated mice until five months of age. Similar high titers of anti-DNA antibodies and renal deposition of IgG were seen in both groups of mice. PCA rose with age in both ancrod treated and untreated mice, although it was significantly higher in control animals than in the ancrod treated group. Furthermore, ancrod therapy resulted in a decrease in plasma PCA inducing activity (PIF) and a decrease in the effectiveness of PIF to induce PCA in peritoneal macrophages in vitro. No mortality was observed in the 20 ancrod treated mice, whereas 10 of 20 control animals died. We conclude that defibrination with ancrod delays the development of renal fibrin deposition and glomerulonephritis and improves survival in BXSB mice. This was associated with a decrease in plasma PCA inducing activity and with an inhibitory effect on PCA induction. These results suggest that PCA contributes to injury in murine lupus glomerulonephritis by promoting fibrin deposition.

Cyclosporin A metabolites suppress T-cell proliferation by concanavalin A and in a mixed lymphocyte reaction

To ascertain if cyclosporine metabolites (CMs) have immunosuppressive activity, bile, whole blood and urine taken from patients after cholecystectomy and from a liver transplant recipient on cyclosporin A (CsA) were assayed to determine their effect on T-cell proliferation induced by concanavalin A (Con A) and in a two-way mixed-lymphocyte response. Bile and whole blood from the liver transplant patient completely suppressed Con A proliferation and the mixed lymphocyte response (MLR) at dilutions at which normal bile and whole blood have no suppressive activity, but no such activity was noted from the urine. The CMs were separated into six peaks (fractions) by high-pressure liquid chromatography (HPLC). Metabolites were identified by internal standards and HPLC/mass spectrophotometric analysis. Cyclosporine metabolite fractions 2 and 3 from bile and blood had immunosuppressive activity similar to parent CsA whereas fractions 5 and 6 demonstrated less but substantial immunosuppressive activity. Fractions 2, 3 and 5 demonstrated an ability to inhibit two-way MLR similar to parent CsA; the other metabolite fractions were able to inhibit the MLR but to a lesser extent. These results demonstrate that a number of CMs have immunosuppressive effects similar to those of the parent compound, and this may account for the lack of correlation between whole blood CsA levels and immunosuppressive activity.

In vitro receptor specificity of the 5HT1A selective phenylpiperazine, LY165163

LY165163, a ligand reported to be selective for the 5HT1A subtype of serotonin receptor, was examined for its ability to interact with 5HT2 receptors in the rat jugular vein and alpha-receptors in the rat aorta. In these smooth muscle preparations, no agonist activity of LY165163 occurred in concentrations up to 10(-5) M. However, LY165163 was an antagonist of serotonin-induced contractions in the jugular vein and of norepinephrine-induced contractions in the rat aorta. The dissociation constant calculated for LY165163 at 5HT2 receptors in the rat jugular vein was 10(-8) M and at alpha-receptors in the rat aorta was 2 X 10(-7) M. Thus, LY165163 is a relatively potent antagonist at vascular 5HT2 sites and possesses appreciable affinity at alpha-receptors. Based on these data, the multiple receptor interactions of LY165163 must be taken into consideration when utilizing this agent as a probe for the 5HT1A subtype of serotonin receptor.

Effect of nitrendipine, diltiazem, trifluoperazine and pimozide on serotonin2 (5-HT2) receptor activation in the rat uterus and jugular vein

The present study explored the calcium source used in serotonin (5-HT)-induced contractions mediated by 5-HT2 receptor activation in the rat uterus and jugular vein in vitro. In the rat uterus, the calcium channel antagonists, nitrendipine and diltiazem, and the neuroleptic agents, trifluoperazine (TFP) and pimozide, antagonized potently and noncompetitively 5-HT-induced contractions. These data are compatible with the contention that 5-HT-induced contractions in uterine smooth muscle require extracellular sources of calcium. In contrast, neither diltiazem nor nitrendipine inhibited the contractile response to 5-HT in the rat jugular vein although 5-HT-induced contractions in the jugular vein required the presence of extracellular calcium. This difference in sensitivity to calcium channel antagonists between the uterus and jugular vein was not related to differences in the receptor occupancy-response curves for 5-HT as these were similar in the rat uterus and jugular vein. Furthermore, in the jugular vein, neither diltiazem nor nitrendipine were markedly effective in blocking contractions produced by potassium chloride, an agent that activates voltage-dependent calcium channels, suggesting that this tissue lacks calcium channels susceptible to blockade by conventional calcium channel antagonists. Although responses to 5-HT in the jugular vein were only affected marginally by calcium channel antagonists, TFP and pimozide produced concentration-dependent rightward parallel shifts of 5-HT-induced contractions in the jugular vein. Furthermore, both TFP and pimozide showed high affinity at 5-HT2 binding sites in rat brain cortical membranes and the apparent dissociation constant at 5-HT2 receptors in the jugular vein was 38 and 31 nM, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro evaluation of anticancer drugs against ovarian cancer at concentrations achievable by intraperitoneal administration

High-dose intraperitoneal chemotherapy is a current developmental approach in the treatment of advanced ovarian cancer. Considerable pharmacologic data have been obtained on the intraperitoneal X time product for a number of agents administered by this route. We used the human tumor cloning assay (HTCA) to compare the activities of both standard and experimental agents used for intraperitoneal treatment. In vitro dose-survival curves were constructed for each drug over a two-log range of concentrations using fresh ovarian cancers from more than 50 patients. The mean concentration X time product (CXT) achievable in the intraperitoneal space after high-dose intraperitoneal drug administration was divided by the corresponding ID50 value (concentration of drug in vitro associated with 50% survival of tumor colonies) for each agent to calculate in vivo CXT: in vitro ID50 ratios. Using this approach, the standard agents, melphalan, cisplatin, and 5-FU were predicted to have similar efficacies by intraperitoneal administration, but doxorubicin and mitomycin were significantly inferior. Of the drugs tested, the new agent mitoxantrone was associated with the most favorable CXT to ID50 ratio and is, therefore, predicted to be particularly promising for intraperitoneal administration.

Phase I trial of carboplatin-cyclophosphamide and iproplatin-cyclophosphamide in advanced ovarian cancer: a Southwest Oncology Group study

The Southwest Oncology Group has carried out a phase I clinical trial of carboplatin plus cyclophosphamide and iproplatin plus cyclophosphamide in 20 patients with stages III and IV ovarian cancer prior to initiating a phase III trial to compare these platinum analog-cyclophosphamide combinations with standard cisplatin-cyclophosphamide therapy. Myelosuppression proved the dose-limiting toxicity of both the carboplatin (300 mg/m2) plus cyclophosphamide (600 mg/m2) and iproplatin (180 mg/m2) plus cyclophosphamide (600 mg/m2) regimens. Evaluating up to six courses of therapy (repeated at 4-week intervals), the median nadir WBC and platelet counts associated with carboplatin-cyclophosphamide therapy were 1800 (range, 900-4000) and 69 000 per microliter, respectively, and those associated with iproplatin-cyclophosphamide therapy were 1400 (1100-1600) and 140 000 per microliter, respectively. Although the starting doses of carboplatin and iproplatin required a median decrease of 25%, the median doses of each administered through six courses of therapy were 300 and 180 mg/m2, respectively. Neither nephrotoxicity nor neuropathy were experienced by the patients, but mild to moderate nausea and vomiting occurred in more than 75% of those treated with either drug combination. Alopecia of mild to severe degree was observed in 40% of patients. Although the results of this phase I trial are still preliminary, we can recommend for future phase III trials 300 mg/m2 carboplatin and 180 mg/m2 iproplatin when combined with 600 mg/m2 cyclophosphamide repeated a 4-week intervals for six treatment courses.

5HT2 receptors in the rat portal vein: desensitization following cumulative serotonin addition

Contractile responses to serotonin were examined in vitro in the longitudinal portal vein to determine whether such responses were mediated by the interaction of serotonin with 5HT1 receptors (those that preferentially bind [3H]serotonin) or 5HT2 receptors (those that preferentially bind [3H]spiperone). Using eight serotonin receptor antagonists (spiperone, metergoline, LY53857, ketanserin, trazodone, benzoctamine, 1-(1-naphthyl)piperazine, and 1-meta-methoxyphenylpiperazine), we found a significant correlation between the affinity for serotonin receptors in the rat portal vein and the ability to bind to 5HT2, but not 5HT1 receptors in rat frontal cortical membranes. Thus, the receptors mediating vascular contraction to serotonin in the rat portal vein were similar to those receptors defined in other vascular beds from the rat (aorta, jugular vein,and caudal artery). Furthermore, contraction resulting from the cumulative addition of serotonin in the rat portal vein was associated with desensitization (higher ED50 value) relative to contractions produced by the non-cumulative addition of serotonin. Affinities of serotonin receptor antagonists were also lower when determined by antagonism of cumulative serotonin concentration-response curves compared to affinities obtained by antagonism of non-cumulative concentration-response curves. Thus, 5HT2 receptor affinities of antagonists in the rat portal vein are best determined by the shift of non-cumulative responses to serotonin.

The transsexual dilemma: being a transsexual

With few exceptions, a solution to any problem will bring new difficulties. These may or may not be worse than the original problem, and one must decide, not between problem and answer, but between degrees of difficulty. Is the new situation really going to be better than the last? This is undoubtedly the situation with the transsexual. It is undeniable that in the majority of cases the treated transsexual is an infinitely happier person than the one who has not undergone therapy, but as a result of this treatment there arises a host of new difficulties. Using personal experience, it is my intention to illustrate the problems which beset the transsexual before, during and after treatment. It will then be possible to ascertain whether or not, in spite of these difficulties, there is in fact a dilemma. Is there indeed any choice?

Antitumour activity and plasma kinetics of bleomycin by continuous and intermittent administration

We have studied the cytotoxicity of bleomycin (4--10 u/kg/day for 6 days) given by continuous i.p. infusion (using an osmotic minipump) compared to daily i.p. bolus administration, against P388 leukaemic spleen colony-forming-units(LCFU-S). Continuous i.p. bleomycin at 8 u/kg/day caused a 0.5 log greater reduction of LCFU-S than did an identical dose given by intermittent bolus administration. The infusion minipump provided constant bleomycin plasma levels of 0.62 +/- 0.03 mu/ml and a total plasma AUC (area under the plasma decay curve) of 89.0 mu.h/ml for 6 days at 8 u/kg/day. Intermittent bolus bleomycin at 8 u.kg/day had a terminal-phase plasma t1/2 of 15 min and a total 6-day plasma AUC of 90.8mu.h/ml. These pharmacokinetic data validate the osmotic minipump as a constant drug-delivery system, and suggest that the two administration schedules resulted in equal total bleomycin dosages. Although high peak bleomycin plasma levels (i.e. 32 mu/ml) were achieved with the intermittent bolus administration, continuous-infusion bleomycin's greater inhibition of LCFU-S was probably related to the drug's schedule-dependent cell-killing characteristics. The results of this study provide further rationale for the continuing use of infusion bleomycin schedules in cancer patients.

In vivo and in vitro evaluation of a microencapsulated narcotic antagonist

Injectable microcapsules containing 75% (w/w) cyclazocine, a narcotic antagonist, were prepared with dl-poly(lactic acid) as the coating material. Capsule fractions falling between 105 and 295 mum released about 90% of their cyclazocine in 8 days of rotating-bottle extraction at 37 degrees in pH 7.4 phosphate buffer. Although larger capsules released the drug somewhat more slowly, all capsules released cyclazocine far more rapidly than an ideal capsule should. This rapid release is attributed to macroscopic defects located in the capsule walls. The ability of the capsules to block the action of morphine in vivo was assessed by injection of a sesame seed oil suspension into Holtzman rats. A hot-plate test procedure was used to evaluate animal behavior. Capsule doses of 100-250 mg/kg to rats caused significant antagonism of morphine's analgesic effect for 14 days after injection. By Day 17, no antagonism occurred, indicating that the capsules completely released the drug in vivo between 14 and 17 days after injection.