Seungnoidan increases cerebrocortical ATP and acetylcholine contents in ovariectomized rats

This study investigated the effects of Seungnoidan (SND), which has been widely used as a remedy for cerebroneuronal diseases in Korean folk medicine, on the cerebrocortical adenosine triphosphate (ATP) and acetylcholine (ACh) contents in ovariectomized (OVX) rats. Female Sprague-Dawley rats were ovariectomized and maintained for 12 weeks to deplete ovarian steroid hormones, followed by oral administration of SND at 500 mg/kg/day for 14 weeks. SND markedly attenuated the high rate of body weight increase in OVX rats, and also reduced the decline of cerebral weight caused by ovariectomy (p < 0.05). Superfusion of SND at 50 mg/kg significantly increased the rate of cerebral blood fl ow, but did not change the mean arterial blood pressure. Deprivation of ovarian steroid hormones significantly decreased the cerebral ATP, choline and ACh contents, and these reductions were reduced by treatment of OVX rats with SND (p < 0.01). Additionally, SND also significantly elevated the cerebral choline acetyltransferase activities reduced by OVX (p < 0.01). Taken together, these results suggest that the pharmacological properties of SND may be implicated in the improvement of metabolic pathways of cerebral energy and cholinergic neurotransmitter function induced by deprivation of ovarian steroid hormones, and SND may be a promising herbal remedy for treatment of cerebral dysfunctions including dementia.

Adenocarcinoma arising from an ectopic pancreas in the stomach

Ectopic pancreas is rare, being found in between 0.6 % and 15 % at autopsy. Heterotopic pancreas is usually an asymptomatic condition which is found incidentally at surgery or at autopsy. Occasionally, significant symptoms arise from complications, such as recurrent upper gastrointestinal bleeding, biliary or intestinal obstruction, or malignant degeneration. Malignant change is very rare. We report a case of malignant change (adenocarcinoma) in an ectopic pancreas in the stomach. In the literature, there are eight reported cases of malignant change in ectopic gastric pancreas. The prognosis in the other reported cases is unknown, but in our patient, the tumor was confined to the muscle of the stomach and there was no lymph node invasion.

Ionizing radiation can overcome resistance to TRAIL in TRAIL-resistant cancer cells

Although the majority of cancer cells are killed by TRAIL (tumor necrosis factor-related apoptosis-inducing ligand treatment), certain types show resistance to it. Ionizing radiation also induces cell death in cancer cells and may share common intracellular pathways with TRAIL leading to apoptosis. In the present study, we examined whether ionizing radiation could overcome TRAIL resistance in the variant Jurkat clones. We first selected TRAIL-resistant or -sensitive Jurkat clones and examined cross-responsiveness of the clones between TRAIL and radiation. Treatment with gamma-radiation induced significant apoptosis in all the clones, indicating that there seemed to be no cross-resistance between TRAIL and radiation. Combined treatment of radiation with TRAIL synergistically enhanced killing of TRAIL-resistant cells, compared to TRAIL or radiation alone. Apoptosis induced by combined treatment of TRAIL and radiation in TRAIL-resistant cells was associated with cleavage of caspase-8 and the proapoptotic Bid protein, resulting in the activation of caspase-9 and caspase-3. No changes in the expressions of TRAIL receptors (DR4 and DR5) and Bcl-2 or Bax were found after treatment. The caspase inhibitor z-VAD-fmk completely counteracted the synergistic cell killing induced by combined treatment of TRAIL and gamma-radiation. These results demonstrated that ionizing radiation in combination with TRAIL could overcome resistance to TRAIL in TRAIL-resistant cells through TRAIL receptor-independent synergistic activation of the cascades of the caspase-8 pathway, suggesting a potential clinical application of combination treatment of TRAIL and ionizing radiation to TRAIL-resistant cancer cells.

CT features of primary colorectal signet-ring cell carcinoma

PURPOSE

The purpose of this work was to evaluate the CT features of 15 patients with primary colorectal signet-ring cell carcinomas.

METHOD

We retrospectively reviewed the CT scans of 15 patients (mean age 44 years) with pathologically proved colorectal signet-ring cell carcinoma. On CT, we evaluated the site and length of the tumor, bowel wall thickening patterns, perirectal or pericolic infiltration, the presence or absence of colonic obstruction, and metastasis to other organs.

RESULTS

The tumors were located in the rectum in nine patients, the sigmoid colon in one, the hepatic flexure in one, the transverse colon in one, the ascending colon in two, and the cecum in one. The tumor length ranged from 4.0 to 10.0 cm (mean 6.1 cm) with mean thickness of 2.1 cm. CT showed concentric bowel wall thickening in all patients ("even" in 8 and "uneven" in 7), target appearance was noted in 4, perirectal or pericolic infiltrations were moderate to severe in 12, and colorectal obstruction was seen in 6. In the tumor spread patterns, lymphadenopathy was noted in 13, invasion to adjacent pelvic organs in 5, peritoneal carcinomatosis in 4, liver metastasis in 2, and periureteric metastasis in 1.

CONCLUSION

Primary signet-ring cell colorectal carcinoma should be included for differential consideration when CT shows a long length of concentric bowel wall thickening and target sign, especially when such findings occur in the rectum and in young patients.

Differential expression of house-keeping genes of Aspergillus nidulans during sexual development

The rpl3 gene and the rpl37 gene for Aspergillus nidulans ribosomal protein L3 (RPL3) and RPL37, which were identified as located on chromosome I and chromosome III, respectively, were isolated from chromosome-specific cosmid libraries. The nucleotide sequences of both of the rpl3 gene and the rpl37 gene identified the ORFs of 392 amino acids and 92 amino acids, respectively. Both of the two genes were present in a single copy. The expression of both genes together with two other house-keeping genes, the rps16 gene for RPS16 and the gene for gamma-actin, was analyzed during sexual development. All four genes showed nearly identical expression patterns in that each gene expression reached its maximum after 2 h, decreased thereafter, and increased again after 30-40 h of induction of sexual development.

Similarity in the linear and non-linear oral absorption of drugs between human and rat

OBJECTIVE

The main aim of this study was to provide a simple, pharmacokinetic rationale for great similarity in the extent (Fab) of gastrointestinal absorption of about 100 different, diverse compounds between human and the rat in linear dosing range, and to test the general applicability of a novel empirical method to correlate the non-linear Fab between the human and the rat by normalizing doses by body surface area (BSA) or body weight 0.67.

METHOD

The mean small intestinal transit time (t) of 36 rats was estimated from the reported study, and this was used to compare with that in humans. The reported great similarity in apparent first-order absorption rate constants (k) of seven structurally diverse compounds between the two species were obtained. Extensive computer search was made and non-linear Fab data for the two species were obtained for chlorothiazide, acyclovir, miglitol and pafenolol.

RESULTS

The mean t for rats was estimated to be 3.32 h which is almost identical to that reported in humans. The great similarity in Fab between human and rat in linear absorption range can be rationalized by similar t and k between the two species. The markedly different Fab vs dose/kg of body weight profiles between human and rat for the four drugs showing dose-dependent Fab were found to collapse when doses were normalized by BW0.67.

CONCLUSION

For Fab not limited by the solubility problem, the great similarity in Fab between human and rat in linear absorption range can be rationalized by the similar t and k. For non-linear Fab drugs, great similarity in Fab can also be obtained between human and rat when doses are normalized by BSA or BW0.67. Regardless of absorption properties (active, passive or facilitated), similar Fab between the two species may be generally obtained when doses used in humans are about 5 to 7 times lower than that in rats. The above findings may be valuable in drug development.

CT of patients with right-sided colon cancer and distal ileal thickening

OBJECTIVE

The purpose of this study was to analyze the incidence and primary causes of distal ileal wall thickening in 131 patients with right-sided colon cancer.

SUBJECTS AND METHODS

During a 2-year period, 131 patients underwent surgical resection for right-sided colon cancer. Of these patients, we analyzed 13 who had distal ileal wall thickening on CT before surgery and also had the cause determined at pathology. CT findings were analyzed with regard to the morphologic features of colonic tumors, bowel wall involvement patterns of the distal ileum, and changes in the pericolic space.

RESULTS

Distal ileal wall thickening occurred in 13 (10%) of the 131 patients who had right-sided colon cancer. Three patients had polypoid colon cancer, whereas the other 10 had infiltrative colon cancer. The mean thickness of the involved colonic segments was 1.6 cm (range, 1.0-2.2 cm) with a mean length of 5.2 cm (range, 2.5-10.0 cm). Pericolic infiltration was mild in six patients and moderate in four patients. The mean length and thickness of the affected ileal segments were 3.2 cm (range, 1.5-6.0 cm) and 1.1 cm (range, 0.7-2.0 cm), respectively. On histopathologic examination, neoplastic processes involved the distal ileum in nine (69%) of the 13 patients. This involvement was caused by either direct tumor invasion in seven patients or lymphatic spread in two. In four patients (31%), nonneoplastic processes with edema and congestion involved the distal ileum.

CONCLUSION

The distal ileum may be abnormally thickened in about 10% of patients with right-sided colon cancer; this thickening results from tumor extension (69%) or a nontumorous process (31%).

The rpl16a gene for ribosomal protein L16A identified from expressed sequence tags is differentially expressed during sexual development of Aspergillus nidulans

We obtained 305 expressed sequence tags (ESTs), which are from the poly(A) site to the most proximal MboI site, from mycelia at the early sexual developmental (ESD) stage of Aspergillus nidulans. By comparison of these ESTs with those obtained previously from the vegetative stage and from the late sexual developmental stage followed by Northern blot analyses, genes of 17 ESTs were identified as being expressed more abundantly at the ESD stage than at the vegetative stage. Five of 17 genes were expressed more abundantly in the presence of the veA gene or the nsdD gene, suggesting that these 5 genes may be involved in sexual development. In a gene of one EST, appearing three times among 305 ESTs and identified by GenBank, polyadenylation seemed to occur at two sites. Nucleotide sequences of the gene having the EST and its cDNA revealed that the gene can code for a 202-amino-acid polypeptide with an estimated molecular mass of 23 kDa. The deduced amino acid showed 73% identity to Saccharomyces cerevisiae ribosomal protein L16A (RPL16A), and therefore the gene was named rpl16a. A. nidulans RPL16A had a putative leucine zipper motif and a basic leucine zipper motif like those of other organisms. The expression level of the rpl16a gene, present as a single copy in this organism, reached a maximum after 2 h, decreased thereafter, and increased again 30 to 50 h after the end of induction of sexual development. These results clearly indicated that the rpl16a gene is expressed differentially during sexual development.

Integrated model for performance analysis of all-optical multihop packet switches

The overall performance of an all-optical packet switching system is usually determined by two criteria, i.e., switching latency and packet loss rate. In some real-time applications, however, in which packets arriving later than a timeout period are discarded as loss, the packet loss rate becomes the most dominant criterion for system performance. Here we focus on evaluating the performance of all-optical packet switches in terms of the packet loss rate, which normally arises from the insufficient hardware or the degradation of an optical signal. Considering both aspects, we propose what we believe is a new analysis model for the packet loss rate that reflects the complicated interactions between physical impairments and system-level parameters. On the basis of the estimation model for signal quality degradation in a multihop path we construct an equivalent analysis model of a switching network for evaluating an average bit error rate. With the model constructed we then propose an integrated model for estimating the packet loss rate in three architectural examples of multihop packet switches, each of which is based on a different switching concept. We also derive the bounds on the packet loss rate induced by bit errors. Finally, it is verified through simulation studies that our analysis model accurately predicts system performance.

Evaluation of using dog as an animal model to study the fraction of oral dose absorbed of 43 drugs in humans

PURPOSE

To conduct a retrospective evaluation of using dog as an animal model to study the fraction of oral dose absorbed (F) of 43 drugs in humans and to briefly discuss potential factors that might have contributed to the observed differences in absorption.

METHODS

Mean human and dog absorption data obtained under fasted state of 43 drugs with markedly different physicochemical and pharmacological properties and with mean F values ranging from 0.015 to 1.0 were obtained from the literature. Correlation of F values between humans and dogs was studied. Based on the same references, additional F data for humans and rats were also obtained for 18 drugs.

RESULTS

Among the 43 drugs studied, 22 drugs were virtually completely absorbed in both dogs and humans. However, the overall correlation was relatively poor (r2 = 0.5123) as compared to the earlier rat vs. human study on 64 drugs (r2 = 0.975). Several drugs showed much better absorption in dogs than in humans. Marked differences in the nonliner absorption profiles between the two species were found for some drugs. Also, some drugs had much longer Tmax values and prolonged absorption in humans than in dogs that might be theoretically predicted. Data on 18 drugs further support great similarity in F between humans and rats reported earlier from our laboratory.

CONCLUSIONS

Although dog has been commonly employed as an animal model for studying oral absorption in drug discovery and development, the present study suggests that one may need to exercise caution in the interpretation of data obtained. Exact reasons for the observed interspecies differences in oral absorption remain to be explored.

Preoperative assessment of gastric carcinoma: value of two-phase dynamic CT with mechanical iv. injection of contrast material

OBJECTIVE

The purpose of this study was to evaluate the utility of two-phase dynamic CT performed with mechanical IV injection of a bolus of contrast medium after oral intake of water in the preoperative staging of gastric cancers.

SUBJECTS AND METHODS

We performed incremental dynamic CT in 52 patients with pathologically proved gastric cancers. Dynamic CT findings were prospectively analyzed and correlated with surgical and histopathologic findings. A total of 150 ml of nonionic contrast medium was administered IV with a power injector at a flow rate of 5 ml/sec for 30 sec, and two-phase images were obtained at 30 sec (early phase) and 2 min (equilibrium phase) after the start of bolus injection.

RESULTS

Forty-one advanced gastric carcinomas showed a moderate to marked degree of heterogeneous enhancement in the early phase and homogeneous enhancement of the entire lesion in the equilibrium phase of dynamic CT. The primary tumors were correctly detected with dynamic CT in five (56%) of the nine early gastric cancers and in 41 (95%) of the 43 advanced gastric cancers. The overall detection rate of gastric cancers was 88% (46 of 52 cases). The accuracies of dynamic CT according to TNM staging in determining the depth of tumor invasion, the degree of serosal invasion, and regional lymph node metastasis were 65% (34 of 52 cases), 83% (38 of 46 cases), and 70% (32 of 46 cases), respectively.

CONCLUSION

Our findings show that two-phase incremental dynamic CT with mechanical IV injection of a bolus of contrast medium after oral intake of water improves the diagnostic accuracy of CT over that provided by conventional CT in the preoperative staging of gastric cancers.