MRI features of infarcts with potential cardiac source of embolism in the Yonsei Stroke Registry (YSR), Korea

The determination of the embolic source is crucial to understanding the pathogenesis of ischemic stroke, the initiation of appropriate therapy, and the prevention of recurrent infarctions. In this study we undertook to identify the characteristic features on magnetic resonance images of patients who had suffered from stroke due to cardiac embolism (CE), as classified by TOAST (possible and probable). We retrospectively studied magnetic resonance imaging (MRI) findings of patients with ischemic stroke from the Yonsei Stroke Registry (YSR). On the basis of the TOAST classification, 92 patients were identified to have a potential cardiac source of embolism (PCSE), in which 69 patients were found to have high-risk PCSE and 23 patients medium-risk PCSE. To compare their imaging characteristics, another group of 49 patients who were found to have had a stroke due to large artery-to-artery (ATA) embolism-common or internal carotid artery (CCA, ICA)-were identified. Involvement of the simultaneous superficial and deep territories (58.7%; 6.1%, p < 0.001), and combined new anterior and old posterior circulation (15.2%; 2.0%, p = 0.016) were more frequent in PCSE than ATA embolism. Bilateral anterior hemispheric involvement was also more frequent in the PCSE group, but it did not reach statistical significance (13.0%; 4.1%, p = 0.090). ATA embolism tended to involve only superficial territories compared to PCSE (71.4%; 28.3%, p < 0.001). There were no topographic differences between the high-risk and medium-risk groups. With respect to the etiology of PCSE in our population, atrial fibrillation was the most common. Characteristic MRI features of patients with PCSE, which were not documented previously by computed tomography (CT) included: old and new, involvement of multiple different vascular territories, bilateral anterior hemisphere, as well as anterior and posterior circulation. These MRI features, together with simultaneous superficial and deep territorial involvement, help to differentiate the underlying embolic sources, whether they are cardiac or ATA in origin.

Familial risk of hepatocellular carcinoma among chronic hepatitis B carriers and their relatives

BACKGROUND

Familial predisposition as a risk factor for hepatocellular carcinoma (HCC) in hepatitis B virus (HBV) carriers has not been thoroughly explored.

METHODS

The HCC risk associated with having parents and/or siblings with HCC was evaluated by use of a cohort study of 4808 male HBV carriers. A case-control family study was also conducted on data from first-degree relatives of 553 HBV carriers who had newly diagnosed HCC (case subjects) and 4684 HBV carriers without HCC (control subjects).

RESULTS

In the cohort study, HBV carriers with a family history of HCC had a multivariate-adjusted rate ratio for HCC of 2.41 (95% confidence interval [CI] = 1.47-3.95) compared with HBV carriers without a family history of HCC. For carriers with two or more affected relatives, the ratio increased to 5.55 (95% CI = 2.02-15.26). Cumulative HCC risk by age 70 years was 235.6 per 1000 (95% CI = 95. 3-375.9 per 1000) for HBV carriers with family history compared with 88.9 per 1000 (95% CI = 67.9-109.9 per 1000) for those without. In the case-control family study, first-degree relatives of case subjects were more likely to have HCC (age-sex-adjusted odds ratio [OR] = 2.57; 95% CI = 2.03-3.25) than first-degree relatives of control subjects. The excess risk of HCC among relatives was particularly evident in siblings (sisters-age-adjusted OR = 4.55 [95% CI = 2.22-9.31]; brothers-age-adjusted OR = 3.73 [95% CI = 2. 64-5.27]), but it was also observed in parents. The cumulative risk of HCC to age 80 years was 83.0 per 1000 among relatives of case subjects and 42.0 per 1000 among relatives of control subjects. Among relatives of case subjects, the cumulative risk of HCC was greater if the case subjects were diagnosed before age 50 years (two-sided P =.047). Liver cirrhosis was 2.29 (95% CI = 1.68-3.11) times more frequent in relatives of case subjects than in relatives of control subjects.

CONCLUSIONS

First-degree relatives of patients with HBV-related HCC appear to be at increased risk of HCC and should be considered in the formulation of HCC-screening programs.

Effectiveness of an organ-sharing program in providing zero HLA-A,B,DR mismatched kidneys for transplantation in Taiwan

PURPOSE

This study evaluated the effects of organ sharing on the allocation of kidneys from cadaveric donors to uremic patients from National Cheng Kung University Hospital (CKUH) and National Taiwan University Hospital (NTUH) who were waiting for kidney transplantation.

METHODS

Standard complement-dependent microcytotoxicity assays were used. Human leukocyte antigen (HLA)-A,B,C typing was performed on nylon-wool-enriched T lymphocytes. HLA-DR typing was performed on either nylon-wool-separated B cells or Dynabeads. Isolation of class II-positive cells was performed with commercial typing trays.

RESULTS

Organs were allocated from a total of 88 cadaveric donors to 320 patients treated at CKUH and 179 patients treated at NTUH. Cadaveric kidneys could be allocated with an A,B,DR mismatch to 6.9% of CKUH patients and to 4.7% of NTUH patients. When CKUH and NTUH patients were pooled, the total number of kidneys that could be allocated with 0-A,B,DR mismatch increased to 13.3% (p < 0.004). However, when allocation was assessed using 10,000 potential bone marrow donors instead of the 88 cadaveric donors, kidneys could have been allocated with 0-A,B,DR mismatch to 12% (p = 0.64) of patients. No significant benefit was found when allocation estimates from the 10,000 potential bone marrow donors were compared with those for the 88 cadaveric donors. Use of epitope matching resulted in a 0-A,B cross-reactive epitope group, and a 0-DR mismatch allocation rate of 36.4% in CKUH patients and 31.8% in NTUH patients. This rate increased to 54.6% (p < 0.001) when the patients from these hospitals were pooled.

CONCLUSION

The results of this study demonstrate that the pooling of patients among regional transplant centers in Taiwan can significantly enhance the benefits of an organ donation program through better HLA matching.

Pentoxifylline inhibits human peritoneal mesothelial cell growth and collagen synthesis: effects on TGF-beta

BACKGROUND

Prevention or treatment of peritoneal fibrosing syndrome has become an important issue in patients on continuous ambulatory peritoneal dialysis (CAPD). Recent evidence has suggested that mesothelial stem cell proliferation and matrix over-production predispose the development of peritoneal fibrosis. We investigated whether pentoxifylline (PTX) affects human peritoneal mesothelial cell (HPMC) growth and collagen synthesis.

METHODS

HPMC was cultured from human omentum by an enzymic disaggregation method. Cell proliferation was assayed using a methyltetrazolium uptake method. Cell cycle analysis was performed by flow cytometry. Collagen synthesis was measured by 3H-proline incorporation into pepsin-resistant, salt-precipitated collagen. Prostaglandins and cAMP were determined by enzyme immunoassay. Northern blot analysis was used to determine mRNA expression.

RESULTS

Our data show that PTX inhibited serum-stimulated HPMC growth and collagen synthesis in a dose-dependent manner. Cell cycle analysis showed that PTX arrested the HPMCs in the G1 phase. PTX decreased the procollagen alpha1 (I) mRNA expression either stimulated by serum or transforming growth factor-beta (TGF-beta). PTX did not alter prostaglandins synthesis but dose-dependently increased intracellular cAMP level. PTX, the same as 3-isobutyl-l-methylxanthine, could potentiate prostaglandin E1 (PGE1) increased cAMP levels of HPMC. The antimitogenic and antifibrogenic effects of PTX on HPMC were reversed by N-[2]-((p-Bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide (H-89). Therefore, the mechanism of these effects may be due to the phospodiesterase inhibitory property of PTX.

CONCLUSIONS

These data suggest that PTX may have a role in treating peritoneal fibrosing syndrome.

Color Doppler vascularity index can predict distant metastasis and survival in colon cancer patients

The purpose of this study was to investigate the clinical usefulness of the color Doppler vascularity index (CDVI) in patients with colon cancer before surgery. Forty-four patients with sonographically visible tumor mass of colon cancer were investigated. The CDVI of each tumor was determined using transabdominal color Doppler ultrasound. The CDVI was defined as the ratio of the number of the colored pixels within a tumor section to the number of total pixels in that specific tumor section and was calculated by using Encomate software (Electronic Business Machine Co. Ltd., Taipei, Taiwan). The correlation between the CDVI and clinicopathological factors, mode of recurrence, and patient survival was studied. For comparison, microvessel density (the mean number of microvessels in three areas of highest vascular density at x200 magnification) of the tumors of these 44 patients was also evaluated by using immunohistochemical staining of surgical specimens with anti-CD34. The microvessel density was not correlated with Dukes' classification, clinicopathological factors, and survival. The CDVI was significantly higher in the patients with lymph node metastases and vascular invasion than in those without such metastases and invasion (P = 0.006 and P = 0.0098, respectively). Moreover, in patients with a high CDVI (> 15%) and positive vascular invasion, survival was significantly poorer than in those with low CDVI (< or = 15%) and negative invasion (P = 0.0037 and 0.0039, respectively). Multivariate analysis indicated that liver metastasis, vascular invasion, and CDVI are independent prognostic factors in the patients with colon cancer. According to the mode of recurrence in 36 patients who underwent curative resection, the frequency of the distant organ recurrence was significantly higher in the high CDVI group (40%) than in the low CDVI group (0%). The CDVI is a good preoperative indicator of recurrence and patient survival in colon cancer. Thus, the CDVI may be helpful in stratifying patients for adjuvant therapy.

Pure homonymous hemianopia due to anterior choroidal artery territory infarction

The most consistently observed neurological deficits in the anterior choroidal artery (AChA) territory infarction are pure motor or sensorimotor syndromes. Visual field defects and higher cortical dysfunction are occasionally accompanied, but pure homonymous hemianopia without motor and sensory symptom has never been reported yet. We present 2 patients with pure homonymous hemianopia, whose MRI disclosed cerebral infarction in the well-known territory of the AChA. In most patients with ischemic stroke, pure homonymous hemianopia indicates infarction in the posterior circulation, particularly in the posterior cerebral artery territory. However, the present cases provide evidence that it can also be caused by infarction in the anterior circulation, i.e. the AChA.

Extracorporeal membrane oxygenation support of donor abdominal organs in non-heart-beating donors

Both family consent and legal consent were required for organ/tissue donation from non-heart-beating donors (NHBD) in Taiwan. A district attorney had to come to the bedside to confirm the donor's asystole, confirm the family consent, and complete some legal documents before a legal consent was issued for organ donation. The resultant warm ischemic time would be unpredictably long and in fact precluded the organ donation from NHBD in Taiwan. We developed a method of using extracorporeal membrane oxygenation (ECMO) to maintain NHBD for a longer time and prevent warm ischemic injury of the donor abdominal organs. After ventilator disconnection in NHBD, phentolamine and heparin were injected and mannitol infusion was given. After the donor's asystole was confirmed by the electrocardiogram (EKG) strip recording, the ECMO support was set up through the right femoral veno-arterial route, an occlusion balloon catheter was inserted through the left femoral artery to occlude the thoracic aorta, and bilateral femoral arteries were ligated. Usually, the ECMO could begin within 10 min after the donor's asystole. The ECMO, combined with a cooler, provided cold oxygenated blood to the abdominal visceral organs, and prevented their warm ischemic injuries. Under the ECMO support (range: 45-70 min), eight renal grafts were procured from 4 NHBD. With the exception of the first two renal grafts with delayed function, all others had immediate function postoperatively and dialysis was no longer needed. In conclusion, by our ECMO technique, NHBD could be maintained for a longer time and the renal grafts had better immediate postoperative function than those reported by other methods.

Teaching of space life sciences

Space life sciences is not really a new life sciences discipline such as immunology was some decades ago and it may never be so. Rather it is a field that will provide each existing life sciences discipline with new and more information gathered from space research. In fact, the danger is that space research will be confined in a separate discipline, and thus it will be cut off from classical ground research. Conversely, scientists should increasingly consider spaceflight as a tool and should integrate the findings of space research into their traditional disciplines. A brief survey of topics and main findings in the various subdisciplines of space life sciences is provided. This is followed by a discussion of typical problems encountered such as access to space, controls, ground-based simulations, medical care in space, extravehicular activity, and environmental control and life support. As many space life sciences courses are initiated around the world either by space agencies or universities or jointly, there is a need to consider the international, intercultural, and interdisciplinary aspects of such programs. It is argued that the growing knowledge derived from space research should be integrated into the regular teaching of life sciences rather than leaving it confined to a separate field. Teaching of space life sciences is a prime candidate for the application of the new techniques of "cyberspace education", where interactive learning and globalization of the learning process will take a leading place. The experts and student body are dispersed over many nations, research is of necessity conducted on a basis of international cooperation. The conduct of tele-education is discussed and existing information sources and courses are listed.

Impact of electrical cable insulating oil on the mineralisation of [1-(14)C]glucose in soil

Subsurface high voltage electric cables are commonly insulated using dodecylbenzene in combination with mineral oil. This work assessed the impact of increasing concentrations of cable insulating oil (0-10% dry weight) on soil microbial respiration as determined by mineralisation of [1-(14)C]glucose (11 microg C g(-1) soil). Acute impact was assessed from 0 days to 21 days, and chronic impact was assessed after 300 days. This study found that cable insulating oil increased respiratory activity of soil microflora. The extent of impact was found to depend on both oil concentration and the length of oil-soil contact time. Following acute exposure (21-days oil-soil contact time), it was found that oil concentrations up to 1% promoted a significant (P<0.05) increase in the extent of [1-(14)C]glucose mineralisation to (14)CO(2) relative to the control. In contrast, higher concentrations of cable insulating oil (5% and 10%) promoted no significant (P0.05) increase in the extent of [1-(14)C]glucose mineralisation to (14)CO(2) relative to the control. Following chronic exposure (300-days oil-soil contact time), the extent of mineralisation was greater at all oil concentrations applied relative to the control. For oil concentrations up to and including 1%, there was a decrease in the extent of elevation in mineralisation relative to the values after 21-days exposure. At higher oil concentrations, namely 5% and 10%, the extent of elevation in mineralisation was comparable with that after 21-days oil-soil contact time. We suggest that the increase in mineralisation of glucose indicates that cable insulating oil is a readily available carbon source to the carbon-limited soil microflora.

Loss of heterozygosity at chromosome 13q in hepatocellular carcinoma: identification of three independent regions

Loss of heterozygosity (LOH) on chromosome 13q is one of the most common genetic alterations in hepatocellular carcinoma (HCC) and might be involved in liver cancer development through inactivation of tumour suppressor genes. In order to narrow down the region of 13q loss, we examined the pattern of loss of heterozygosity (LOH) in tumours from 88 HCC patients, using 18 microsatellite markers on 13q. Thirty-eight of the 88 tumours (43%) showed LOH for at least one marker. Of these, two tumours (5%) showed 13q whole arm allelic loss, while the remaining 36 tumours (95%) had partial allelic loss. The LOH pattern defined by the 36 tumours suggested the existence of at least three different smallest common deleted regions which might be involved in the carcinogenesis of HCC. The first, the most centromeric in the 13q12.3 is, close to the BRCA2 gene, defined by D13S171; the second, the most telomeric region in the 13q31-32 band, is defined by D13S154 and D13S157; the third, the intermediate region at 13q14.3, which is near the RB gene, is defined by loci D13S268. The rate of LOH at 13q31-32 was significantly higher in Hepatitis B-surface antigen (HBsAg)-positive patients than HBsAg-negative HCC patients, pointing to a candidate gene related to the development of HBsAg-positive HCCs.

Oral urografin in postoperative small bowel obstruction

The aim of our study was to determine whether Urografin has the potential to offer surgeons a way of differentiating complete from partial small bowel obstruction and whether partial small bowel obstruction can be treated nonoperatively. Altogether 116 patients who had postoperative small bowel obstructions without any toxic signs underwent Urografin studies. Urografin (40 ml) mixed with 40 ml of distilled water was administrated either orally or via nasogastric tube to each patient. Serial plain abdominal radiographs were taken 2, 4, and 8 hours later. A total of 74 patients (63.8%) whose contrast medium reached the colon within the first 8 hours were considered to have partial obstruction and were successfully treated with intravenous hydration and nasogastric decompression. The remaining 42 patients (36.2%) in whom the contrast medium failed to reach the colon within the first 8 hours were regarded as having complete obstruction, and 34 of those patients (81.0%) underwent surgery; 8 (19.0%) received conservative treatment. Adhesion bands with complete bowel obstruction were observed in all 34 patients (100.0%) during laparotomy. Regardless of the presence of an air-fluid level on a plain abdominal radiograph or abdominal pain, a liquid diet followed by a soft diet could be given to those patients whose Urografin emptied into the colon. All the patients with partial bowel obstruction were treated successfully with nonoperative methods. The presence of Urografin in the colon within 8 hours of ingestion as an indicator for nonoperative treatment had a sensitivity of 90.2%, a specificity of 100%, and an accuracy of 93. 1%. Urografin, a safe and reliable water-soluble contrast medium, can be used to differentiate partial intestinal obstruction from complete intestinal obstruction. Early oral intake was found to be a major advantage of Urografin use in this study, and the potential of Urografin use to shorten the period of conservative treatment for postoperative small bowel obstruction needs further investigation.

Surgical management of refractory exit-site/tunnel infection of Tenckhoff catheter: technical innovations of partial replantation

OBJECTIVE

Catheter-related infection has been the major cause of catheter removal for peritoneal dialysis (PD) patients. A salvage technique--partial replantation of the infected catheter--was developed in our hospital to rescue catheters with refractory exit-site or tunnel infection.

PATIENTS

We performed 26 partial replantations of Tenckhoff catheters for 23 patients with refractory exit-site or tunnel infection and 2 patients with near-cuff perforation of the catheter. Their problems were all resolved successfully without interruption of PD.

INTERVENTIONS

We removed the infected portion of the catheter and preserved the still-functioning internal conduit, connecting it to a divided new catheter. All of the patients resumed PD immediately after the advancement of the new catheter through a new subcutaneous tunnel and exit site on the opposite side.

RESULTS

No technical complications such as disconnection of the catheter or leakage of dialysate were noted. Repeated partial replantation of the catheter was done for 1 patient with a new refractory exit-site infection. Tunnel infection was not an absolute contraindication for this procedure. About one third (34.6%) of our patients had preoperative tunnel infection.

CONCLUSION

Partial replantation of a Tenckhoff catheter is a simple and effective procedure for patients with refractory exit-site/tunnel infection and patients with near-cuff perforation of the catheter. Repeated partial replantation is also feasible for repeat exit-site infections.

PTEN/MMAC1 mutations in hepatocellular carcinomas

Mutations in the PTEN/MMAC1 gene have been identified in several types of human cancers and cancer cell lines, including brain, endometrial, prostate, breast, thyroid, and melanoma. In this study, we screened a total of 96 hepatocellular carcinoma (HCC) samples from Taiwan, where HCC is the leading cancer in males and third leading cancer in females, for mutations in the PTEN/MMAC1 gene. Complete sequence analysis of these samples demonstrated a missense mutation in exon 5 (K144I) and exon 7 (V255A) from HCC samples B6-21 and B6-2, respectively. A putative splice site mutation was also detected in intron 3 from sample B6-2. Both B6-21 and B6-2 were previously shown to contain missense mutations in the coding sequences of the p53 gene. Functional studies with the two missense mutations demonstrated that while mutation V255A in exon 7 resulted in a loss of phosphatase activity, mutation K144I in exon 5 retained its phosphatase activity. Additionally, we identified a silent mutation (P96P) in exon 5 of the PTEN/MMAC1 gene from HCC sample B6-22. These data provide the first evidence that the PTEN/MMAC1 gene is mutated in a subset of HCC samples.

Serum hepatocyte growth factor before and after resection for hepatocellular carcinoma

BACKGROUND/AIMS

Hepatocyte growth factor (HGF) is the most potent hepatocyte proliferation stimulator. Serum HGF levels are high in various liver disease states such as cirrhosis, hepatocellular carcinoma (HCC) and hepatitis. But the role HGF plays in HCC is not clear at present. The purposes of this study are: 1) to reveal the HGF profile pre- and post-HCC resection, which has not been well-described before; and, 2) to analyze the relationships between the pre- and post-operative HGF levels and various clinical parameters.

METHODOLOGY

We performed a retrospective cohort study to check the HGF profiles before and after curative resections for HCC and to analyze the relationships between them by using clinical parameters from 35 consecutive patients at the Department of Surgery, National Taiwan University Hospital. Blood samples collected from another 23 healthy individuals admitted for health check-ups were used as normal controls. Serum HGF was determined with an ELISA kit.

RESULTS

The baseline HGF concentration in HCC patients was significantly higher than that in normal controls (1743+/-73 vs. 948+/-54 pg/ml, p<0.0001). The HGF concentrations on post-operative days (POD) 1, 3, 5, 7, and 14 were all significantly higher than those seen in normal controls (all p less than 0.0001). The first and third POD HGF values were significantly higher than the pre-operative level (p=0.00135 and 0.00187 respectively). The HGF concentrations would return to the pre-operative level on the fifth POD, but they never returned to normal level at the end of the two-week study. The pre-operative HGF level was affected by patient age (p=0.0236), and the post-operative peak HGF level was positively correlated with the pre-operative indocyanin green retention rate (ICGR15) and GOT level (p=0.0320 and 0.0234 respectively).

CONCLUSIONS

In this study, we proved, indirectly, that HGF was not secreted by the HCC tumor cells per se. The peak post-operative HGF level reflected the relative stress of the operation on the diseased liver, but did not reflect the absolute physical extent of liver resection. The relationships between HGF and the prognosis of the patients after HCC resection demands further investigation.