Drug interaction between methamphetamine and antihistamines: behavioral changes and tissue concentrations of methamphetamine in rats

Methamphetamine is a psychomotor stimulant, whereas first generation antihistamines cause sedation. Several studies have demonstrated that first generation antihistamines potentiate methamphetamine-induced psychomotor activation and two possible mechanisms have been postulated. One is blockage of the central histaminergic neuron system and the other is inhibition of dopamine reuptake. However, the exact mechanism is still controversial. In this study, we examined in behavioral tests the effects of selected antihistamines on methamphetamine-induced psychomotor activation in rats, and measured plasma and brain tissue concentrations of methamphetamine. We found that some antihistamines significantly potentiate methamphetamine-induced psychomotor activation in rats and that plasma and brain tissue concentrations of methamphetamine in rats treated with methamphetamine in combination with D-chlorpheniramine were markedly higher than those in rats treated with methamphetamine alone. These results suggest that the potentiating effects of antihistamines are due to not only central effects but also the alteration of the pharmacokinetics of methamphetamine.     

Ethnic differences in prediction of violence risk with the HCR-20 among psychiatric inpatients

OBJECTIVE: This study examined ethnic differences in assessment of violence risk among psychiatric inpatients by using the Historical Clinical Risk Management-20 (HCR-20). METHODS: The HCR-20 was administered to 169 consecutive psychiatric inpatients. Individual items and total scores on the HCR-20 were compared between patients of Asian-American (N=51), Euro-American (N=46), and Native-Hawaiian (N=38) heritage. Receiver operating characteristic (ROC) and stepwise regressions were calculated for each ethnic group with HCR-20 scores as predictor variables and violent event reports of significant threats and assaults as the outcome measure. RESULTS: Similar rates of overall violence were found between ethnic groups, and the HCR-20 was found to have predictive validity as measured by ROC analysis. Differences in scores on individual HCR-20 items were found, including young age at first incident of violence, psychopathy, early maladjustment, personality disorder, and past supervision failure, as well as total HCR-20 score, with Asian Americans scoring lower (less risk) than Euro-Americans and Native Hawaiians. Stepwise multiple regressions indicated a different pattern of predictor variables for each ethnic group, with impulsivity salient for the Asian-American group, young age at first incident of violence salient for the Euro-American group, and young age at first incident of violence, relationship instability, and risk-management plans' lacking feasibility as salient predictors for the Native-Hawaiian group. CONCLUSIONS: The findings provide preliminary support for the cross-cultural validity of the HCR-20 while at the same time identifying unique ethnic differences in prediction of violence risk among psychiatric inpatients.     

Polycystic kidney and renal cell carcinoma in Japanese and Chinese toad hybrids

Frequent development of renal cell carcinomas in hybrids between Japanese toads (Bufo japonicus) and imported Chinese toads (Bufo raddei) was first reported by 2 of our authors in 1987. Such renal tumors of toads had never been observed previously in the laboratory. To confirm the observation and to establish a new animal model system, hybrids between female Japanese and male Chinese toads were newly generated from 3 pairs of parents and pathological changes in their kidneys were examined sequentially over 6 years. In hybrids from 2 of the 3 pairs, bilateral polycystic kidney developed at a high frequency from 3 months after fertilization, this being associated with the emergence of atypical, premalignant-appearing cells in proximal tubules. Papillary lesions developed after 12 months and renal cell carcinomas after 48 months. Such pathological changes were never seen in non-hybrid Chinese or Japanese toads. Electron microscopy showed no evidence of any viral participation. This unique toad model may prove useful for investigation of the underlying mechanisms of genetically determined renal cell carcinogenesis.     

The impact of pylorus-preserving pancreatoduodenectomy on surgical treatment for cancer of the pancreatic head

Pylorus-preserving pancreatoduodenectomy (PPPD) was reintroduced in 1978. This pylorus-preserving modification was designed to minimize complications related to gastric resection, such as early satiety, marginal ulceration, and bile reflux gastritis, as well as diarrhea and dumping. Since 1978, PPPD has been performed preferentially for benign and malignant diseases of the periampullary region and pancreatic head. Some groups have argued against PPPD for cancer of the pancreatic head, because the pylorus-preserving procedure is likely to compromise the field of resection and does not allow lymph node dissection of the peripyloric and perigastric groups. However, comparative survival rates after PPPD have been the same as, or better than, those with classic pancreatoduodenectomy, showing the rationale for PPPD as a radical resection procedure for cancer of the pancreatic head. PPPD can be performed with low mortality. Delayed gastric emptying, which is the most common complication in the immediate postoperative period after PPPD, is always transient. Many investigators have shown that body weight and the majority of nutritional parameters are better than after PD. PPPD does not appear to cause any negative outcomes. We conclude that PPPD is the surgical procedure of choice for cancer of the head of the pancreas. Received: April 13, 2001 / Accepted: June 6, 2001     

Pylorus-preserving pancreaticoduodenectomy with combined resection of the portal vein and gastrointestinal reconstruction by imanaga procedure for ductal cancer of the head of the pancreas

Twenty-six patients who underwent pyloruspreserving pancreaticoduodenectomy (PPPD) for ductal cancer of the head of the pancreas between 1983 and 1993 were reviewed. Gastrointestinal continuity was restored by the methods of Imanaga (n=21) and Traverso (n=5). Combined resection of the portal vein and/or superior mesenteric vein was performed in 13 patients. Surgical complications occurred in 5 patients, but there were no postoperative deaths. Delayed gastric emptying was observed in 42% of patients. The median survival time for all 26 patients was 13 months. Three patients survived for more than 3 years, and one of them is currently alive without recurrence at 10 years. Differences in survival rates were not apparent between patients who underwent PPPD with and without portal vein resection. Survival rate after PPPD was compared with that after pancreaticoduodenectomy (PD) performed between 1974 and 1992; the difference was not significant. Patients who underwent noncurative PPPD had a significantly better survival rate than those who underwent noncurative PD (P<0.05). PPPD has improved the quality of life of the resected patients, without reducing survival rate. At present, PPPD by the Imanaga procedure could be the best choice for management of cancer of the pancreatic head.     

The reactivities of Bauhinia purpurea and Lens culinaris lectins to mouse B Lymphocytes and their subsets

The use of lectins for the separation of murine spleen lymphocyte subsets was examined. Bauhinia purpurea agglutinin was found to be effective for the enrichment of B cells by differential agglutination. When the differential agglutination technique using lectins was applied to the separation of B cell subsets, Lens culinaris agglutinin was found to be able to fractionate B cells into high responding and low responding subsets for dextran sulfate. A different expression of cell surface IgD was also observed between the cell populations showing different agglutinability with Lens culinaris agglutinin.     

Functional properties of strychnine-sensitive glycine receptors expressed in Xenopus oocytes injected with a single mRNA.

Mature rat spinal cord cDNA libraries constructed in lambda gt10 and lambda ZAPII were screened with an oligonucleotide probe (39 mer), and 4 clones that possess DNA-inserts encoding a glycine receptor subunit were obtained. The cloned cDNAs were used to reconstruct the nucleotide sequence of the full-length open reading frame consisting of 1350 base pairs (bp) as well as the 5'-(184 bp) and 3'-(591 bp) non-coding regions. Synthetic RNA transcribed in vitro from the glycine receptor cDNA induced Xenopus oocytes to synthesize functional glycine receptor that generated large Cl- currents. The electrophysiological properties of the wild-type receptor and some mutant receptors produced by site-directed mutagenesis were analyzed.     

Smoking cessation counseling training for pediatric residents in the continuity clinic setting.

OBJECTIVE: To determine the effectiveness of a clinic-based smoking cessation counseling curriculum on pediatric resident confidence, knowledge, counseling skills, and provision of counseling. METHODS: Twenty-six residents at a pediatric residency program completed a new smoking cessation counseling curriculum as part of continuity clinic training. We assigned residents to 2 groups (study group, n = 12 vs control group, n = 14) on the basis of clinic site. We used a quasi-experimental, crossover design with pre- and posttests for each group. Control-group residents served as an initial control before the intervention crossover. Residents were tested at baseline and at completion of each group's intervention. Standardized patients measured resident provision of counseling and quality of counseling during resident continuity clinic. Knowledge and confidence were measured by a written exam and self-administered survey. Analysis of variance with a mixed design assessed overall group differences and group performances over time. RESULTS: There were no baseline differences between groups. Across time, there were significant differences between study-group and control-group residents for confidence (F [2, 48] = 11.82; P <.01), knowledge (F [2, 48] = 6.24; P <.01), and provision of counseling (F [2, 48] = 3.60, P <.05) but not counseling skills (F [2, 48] = 2.44; P <.10). After each group's intervention, their confidence, knowledge, counseling skills, and inclusion of counseling increased significantly (P <.01 for all). CONCLUSIONS: Our findings suggest that a clinic-based curriculum in smoking cessation counseling can significantly increase knowledge, confidence, counseling skills, and provision of counseling. Future research should evaluate the long-term impact of such curricula on resident counseling behavior and patient outcomes.     

The effect of dietary restriction on mouse T cell functions

Forty percent dietary restriction on 9-weeks-old C3H/He mice caused decrease of the weight of central lymphoid organs in parallel with the reduction of body weight. However, the percentage of splenic T cells was dramatically increased in diet-restricted mouse spleen cells. Generally, normal mouse spleen cells contained about 30% of Thy 1.2+ T cells, but the restricted mouse spleen cells contained 80% Thy 1.2+ T cells. Ly 1+, L3T4+ T cells, but not Ly 2+ T cells, also increased in diet-restricted mouse compared with the unrestricted mice. In parallel with the dramatic changes of splenic T cells, spleen cells obtained from diet-restricted mice showed higher immunological responses against alloantigen and interleukin 2. It was also demonstrated than nylon-passed splenic T cells obtained from diet-restricted mice showed higher levels of T cell responses against r-IL-2 and alloantigen, indicating that dietary restriction modulates T cell functions themselves.