R-(-)-ketamine modifies behavioral effects of morphine predicting efficacy as a novel therapy for opioid use disorder1

Substance abuse disorder continues to have devastating consequences for individuals and society and current therapies are not sufficient to provide the magnitude of medical impact required. Although some evidence suggests the use of ketamine in treating various substance use related- symptoms, its adverse event profile including dissociation, dysphoria, and abuse liability limit its potential as a therapy. Here, we outline experiments to test our hypothesis that (R)-ketamine can both alleviate withdrawal symptoms and produce effects that help sustain abstinence. In morphine-dependent rats, (R)-ketamine alleviated naloxone-precipitated withdrawal signs. (R)-ketamine also blocked morphine-induced place preference in mice without inducing place preference on its own. We also evaluated whether (R)-ketamine would induce anhedonia, a counter-indicated effect for a drug abuse treatment agent. S-(+)- but not R-(-)-ketamine produced anhedonia-like responses in rats that electrically self-stimulated the medial forebrain bundle (ICSS). However, time-course studies of ICSS are needed to fully appreciate these differences. These data begin to support the claim that (R)-ketamine will dampen withdrawal symptoms and drug liking, factors known to contribute to the cycle of drug addiction. In addition, these data suggest that (R)-ketamine would not produce negative mood or anhedonia that could interfere with treatment. It is suggested that continued investigation of (R)-ketamine as a novel therapeutic for substance abuse disorder be given consideration by the preclinical and clinical research communities. This suggestion is further encouraged by a recent report on the efficacy of (R)-ketamine in treatment-resistant depressed patients at a dose with little measurable dissociative side-effects.

Pramipexole augmentation in the treatment of unipolar and bipolar depression: a retrospective chart review

OBJECTIVE

To assess the effectiveness and safety of pramipexole as an adjunctive medication in refractory bipolar and unipolar depression in a naturalistic setting.

METHODS

Retrospective chart review by psychiatrists on staff at a university hospital identified all patients who had received pramipexole. Response was based on moderate to marked improvement in the Clinical Global Impression-Improvement (CGI-I) scale.

RESULTS

Pramipexole (mean dose 0.70 mg/d, mean duration 24.4 weeks) was effective in 6/12 (50.0%) of patients with bipolar depression, and 8/20 (40%) of patients with unipolar depression, mean duration of follow-up of 24.4 weeks. One case of transient hypomania was noted. Eight patients discontinued pramipexole due to lack of response and four due to side effects.

CONCLUSIONS

Pramipexole, used as an adjunct to antidepressants or mood stabilizers, appeared to be effective and safe in the treatment of unipolar and bipolar depression. These uncontrolled, retrospective, naturalistic pilot data require confirmation by controlled research before conclusions can be made.

The anticonvulsant lamotrigine in treatment-resistant manic-depressive illness

Anticonvulsants are used extensively in the treatment of bipolar disorder. Treating depression in bipolar disorder can be difficult because of the limited antidepressant effects of the standard mood stabilizers and the tendency of antidepressants to induce mania or decrease cycle length. Lamotrigine is a new anticonvulsant with few side effects that may have mood-stabilizing and elevating effects. Its mechanism of action probably involves the inhibition of excessive release of excitatory amino acids such as glutamate. Antiglutamatergic agents may be antidepressant and mood stabilizing. A case series of 16 patients treated with lamotrigine (dose range 50 mg to 250 mg, mean dose of responders = 141 mg) is presented along with two case reports. All patients were considered treatment-resistant bipolar type I or II. Patients were rated on average 5 weeks after starting lamotrigine using a semistructured follow-up form that included symptom rating, Clinical Global Impressions (CGI), and Global Assessment of Functioning (GAF) scores. Eight of 16 patients were rated as "responders" (CGI < or = 2) and had a mean increase of 16 in their GAF scores. Lamotrigine seems to have antidepressant and mood-stabilizing effects, but this requires confirmation in randomized, controlled trials.

Concurrent 72-hour continuous infusion of etoposide and cisplatin in metastatic breast cancer

We conducted a multiinstitutional phase II clinical trial to determine the toxicity, response, and survival rate of concurrent 72-h continuous infusion of etoposide and cisplatin in patients with metastatic breast cancer. A total of 26 women were enrolled, 4 of whom received no prior chemotherapy for metastatic disease. All patients were evaluated for toxicity, response, and survival employing the National Cancer Institute (NCI) Common Toxicity Criteria and the Eastern Cooperative Oncology Group (ECOG) response criteria. A total of 84 cycles of therapy were administered, median 3 (range 1 to 6). Severe grade 3 and grade 4 neutropenia occurred in 22 cycles (26%), and there were only 11 episodes (11%) of similar grade thrombocytopenia. Nausea and vomiting were seen in one third of cycles. A single patient (4%) had a complete remission, and seven patients (27%) had partial remissions for an overall objective response rate of 31% (95% confidence interval, 13 to 49%). Three of four patients (75%) without prior therapy for metastatic disease had objective responses. Median survival was 7 months. This combination regimen is active in extensively treated patients with metastatic breast cancer. It is responsible to further investigate the role of etoposide-cisplatin combination chemotherapy as firstline therapy for patients with metastatic breast cancer.

The role of flow cytometry in the diagnosis of lymphoma: a critical analysis

Flow cytometry, now used routinely to aid in the classification of leukemias, is increasingly being evaluated as a rapid technique for determination of surface antigens on the cells teased from lymph nodes and other masses with suspected lymphoma. The present study reviews biopsy specimens from patients examined during a two year period which were sent for flow cytometry with a diagnosis of suspected lymphoma. Sixteen of 25 samples (64 percent) produced cell suspensions of sufficient quantity and quality to be diagnostically helpful. Results showed that in 9/16 (56 percent) the diagnosis of lymphoma or cancer could be suspected by flow cytometry alone, while 4/16 were consistent with the final tissue diagnosis of normal or reactive hyperplasia. Three samples that came from patients who had morphologic evidence of malignant disease on biopsy (two Hodgkin's disease and one large cell lymphoma) had flow cytometry results that were interpreted as normal. Flow cytometry is rapid and appears to be virtually diagnostic of non-Hodgkin's lymphoma when a majority of cells are B cells with an abnormal kappa/lambda ratio (> 4.0 or < 0.25). Nonhematologic malignancy can be suspected if less than 75 percent of the cells show CD45 (common leukocyte antigen). Hodgkin's disease cannot be detected by flow cytometry as it is currently used, and as many as 15 percent (1/6 in this study) of lymphomas may show normal results. It is extremely helpful when the biopsy sample actually contains the cells of interest in large proportion. Loss of architectural relationships in the course of processing specimens for flow cytometry is a major disadvantage when small foci of lymphoma or tumor cells exist together with large amounts of stroma or normal lymphocytes.

Acute adult T-cell leukemia/lymphoma presenting with florid cutaneous disease

Adult T-cell leukemia/lymphoma (ATLL) is characterized by cutaneous disease, hypercalcemia, associated HTLV-I infection, and a fulminant course refractory to therapy. A patient with acute ATLL is described, and the natural history of ATLL is reviewed.

Platinum in blood mononuclear cells from patients after cisplatin therapy

The feasibility of monitoring cisplatin chemotherapy by measuring platinum (Pt) concentrations in blood mononuclear cells was tested in six patients (four with squamous cell carcinomas of the head and neck, one with non-Hodgkin's lymphoma, and one with lung carcinoma). Blood samples (20 to 40 mL) were collected at intervals from 6 min to 21 days after an iv infusion of cisplatin (80 or 100 mg per m2). Blood mononuclear cells were harvested on a Ficoll-Hypaque gradient, washed repeatedly, counted, and homogenized by sonication in 0.5 mL of saline solution. Pt was analyzed in duplicate 40 microL samples of plasma (N = 26) or cell homogenates (N = 23) by electrothermal atomic absorption spectrophotometry with Zeeman background correction. Immediately after the cisplatin infusion, plasma Pt concentrations averaged 2.6 (SD +/- 0.2) mg per L and mononuclear cell Pt concentrations averaged 2.5 +/- 0.5 ng per 10(6) cells. At 24 to 26 hr post-infusion, plasma Pt concentrations averaged 1.6 +/- 0.2 mg per L and mononuclear cell Pt concentrations averaged 2.3 +/- 0.6 ng per 10(6) cells. Plasma Pt disappearance followed two-compartment kinetics in all patients; the plasma Pt disappearance half-time (T1/2, mean +/- SD) was 148 +/- 41 hours. The Pt concentrations in blood mononuclear cells diminished gradually during the period of observation; the T1/2 could not be reliably determined, but was estimated to be longer than two weeks. This study shows that Pt can be measured in mononuclear cells of patients after cisplatin treatment and that Pt disappears more slowly from blood mononuclear cells than from plasma of these patients.

Selective oocyte degeneration and impaired fertility in rats treated with the aliphatic monoterpene, Citral

Mature female rats treated with Citral (3-7-dimethyl-2,6-octadienal) either topically for 60 or 100 days or by 6 i.p. injections (at 4-5 day day intervals) showed a marked decrease in the number of normal follicles per section, because oocytes tended to degenerate although the follicular cells remained normal. The reproductive performance after Citral treatment was impaired: there was a reduction in implantation number and litter size and an increased post-implantation fetal wastage. None of the young survived after 100 days of topical Citral treatment. It is suggested that Citral directly affects the oocytes.

Glycogen metabolism in the placenta of streptozotocin diabetic rats

Administration of STZ prior to mating, induced significant impairment in glycogen metabolism in term rat placentae. Glycogen retention was observed in the treated placentae, while glycogen synthetase activity was reduced. The glycogenolytic pathway seemed to proceed mainly through amyloglucosidase enzyme whose activity increased threefold. Glucose-6-phosphatase showed a moderate activation, mainly in the labyrinth zone, while phosphorylase was slightly inhibited. These changes were accompanied by a decrease in placental insulin levels. The possible defensive role played by the placenta in cases of maternal hyperglycemia was postulated.