Genetic characterization of the rotaviruses associated with a nursery outbreak

G1P[6] rotaviruses were demonstrated previously to be associated with the neonatal nursery outbreak of gastroenteritis in Changhua Christian Hospital that is located in the central region of Taiwan, from September 1994 to May 1995. Meanwhile, rotaviruses were detected in children hospitalized for acute gastroenteritis. Our study characterizes the rotaviruses associated with the nursery outbreak by using genetic approaches. Nucleotide sequence analysis revealed that the VP7 genes of the nursery rotaviruses were distinct from those of the strains circulating in the community. The G1P[6] rotaviruses recovered from the nursery were closely related to another neonatal G1P[6] strain from the northern region of Taiwan in both the VP4 and VP7 genes. The VP4 genes of these nursery strains differed from those of the P[6] human reference strains 1076, M37, RV3, and ST3. Apparently, these nursery rotaviruses were distinct from the strains circulating in the community and seemed to be a variant when compared with P[6] strains reported previously.

Elevated nitric oxide level in aqueous humor of patients with acute angle-closure glaucoma

Nitric oxide, a noxious and free-radical gas, plays a key role in vasodilatation, inflammation, immunity, and neurotoxicity. Studies have shown that a recently detected NO synthase inducible isoform, found in astrocytes in the optic nerve heads of glaucoma patients, could stimulate excessive production of NO. The purpose of our study was to elucidate the role of NO production in the pathogenesis of glaucoma. We measured the concentrations of NO in aqueous humor from 11 patients with acute angle-closure glaucoma (AACG) and 14 patients with cataract. All samples were collected from patients who were free of any other systemic disease. Utilizing a chemiluminescence assay, we found that in AACG patients the NO levels in aqueous humor samples (83.2 +/- 6.7 microM) were significantly higher than in cataract patients (27.1 +/- 3.6 microM; p < 0.001). We therefore concluded that excessive NO in AACG patients reflects the degree of ocular impairment demonstrated by concomitant retinal cell and optic nerve cell damage.

Intrafamilial transmission and risk assessment of HTLV-I among blood donors in southern Taiwan

The human T-lymphotropic virus type I (HTLV-I) is one of the important etiological agents of adult T-cell leukemia/lymphoma and of HTLV-I associated myelopathy or tropical spastic paraparesis. There is still a lack of data concerning HTLV-I transmission by seropositive carriers in Taiwan. We investigated the patterns of HTLV-I intrafamilial transmission in HTLV-I seropositive blood donors and assessed the risk factors of HTLV-I transmission in relatives of HTLV-I carriers in Taiwan. A total of twenty HTLV-I seropositive donors and their 103 relatives were enrolled. Among those 103 relatives, 40 (38.8%) were seropositive for HTLV-I. Their ages ranged from one to 70 years old with a mean age of 31.0 +/- 1.65 year-old. Three of the ten wives of male carriers were HTLV-I seropositive. However, none of the six husbands of female carriers were HTLV-I seropositive. Mother-to-child vertical transmission was found in nine of 48 (18.8%) tested. Significant risk factors of HTLV-I transmission among relatives of HTLV-I carriers were hospital admission, previous transfusion, breast feeding, anti-HCV seropositivity and female relatives of age >/= 30 with odds ratio (OR) of 9.73, 8.64, 4.36, 8.86 and 4.91, respectively (all p < 0.05). Nonsignificant risk factors of HTLV-I transmission were sharing needles, operation history, HBsAg seropositivity and male relatives of age >/= 30. Our findings suggest that mother-to-child and husband-to-wife transmissions are the important forms of intrafamilial transmission of HTLV-I in Taiwan. Screening for HTLV-I in family members of HTLV-I seropositive blood donors may be warranted.

Infection of human dendritic cells by dengue virus causes cell maturation and cytokine production

Dengue virus (DV) infection is a major problem in public health. It can cause fatal diseases such as Dengue hemorrhagic fever and Dengue shock syndrome. Dendritic cells (DC) are professional APCs required for establishing a primary immune response. Here, we investigated the role of human PBMC-derived DC in DV infection. Using different techniques, including plaque assay, flow cytometry analysis, nested RT-PCR, and confocal microscope and electron microscope examinations, we show that DV can enter cultured human DC and produce virus particles. After entrance, DV could be visualized in cystic vesicles, vacuoles, and the endoplasmic reticulum. The DV-infected DC also showed proliferation and hypertrophy of the endoplasmic reticulum as well as the swollen mitochondria. In addition, the DV-stimulated DC could express maturation markers such as B7-1, B7-2, HLA-DR, CD11b, and CD83. Furthermore, the infection of DC by DV induced production of TNF-alpha and IFN-alpha, but not IL-6 and IL-12. Although DC underwent spontaneous apoptosis in the absence of feeding cytokines, this process appeared to be delayed after DV infection. Our observations provide important information in understanding the pathogenesis of DV infection.

The outcome of shunted hydrocephalic children

BACKGROUND

Neurological sequelae and mental retardation may result from different etiological types of hydrocephalus. The aim of our study is to determine the intellectual development and the "shunt history" of these children with regard to the complications and revision rates.

METHODS

We reviewed the medical history of non-tumoral pediatric hydrocephalic patients who had received first shunt insertions between 1983 and 1997 and had been regularly followed up at the out-patient clinics of Taipei Veterans General Hospital. These patients were categorized into five different etiological groups. Their intelligence test scores and the surgical morbidity encountered over this period were used as the main outcome measures.

RESULTS

Out of the seventy-three patients, post-meningitis hydrocephalus patients had the significantly highest shunt revision rate (2.50 +/- 0.82, p = 0.01). They also showed retardation in IQ scores, but the different was not significant when compared with other groups. The results of IQ tests were not related to either the age of initial shunt insertion (p = 0.461) or revision rates (p = 0.292). For physical disabilities, post-meningitis hydrocephalic patients showed-highest incidence of epilepsy (40%) while hydrocephalic patients associated with myelomeningocele had the highest incidence of motor deficits (56.25%).

CONCLUSIONS

Childhood hydrocephalic patients had different developmental neuroimpairments with respect to different etiologies. This study provides information about the physical and mental outcome of post-operative hydrocephalic patients which is valuable to assist in counsel of their families.

NSP4 gene analysis of rotaviruses recovered from infected children with and without diarrhea

The transmembrane glycoprotein NSP4 functions as a viral enterotoxin capable of inducing diarrhea in young mice. It has been suggested that NSP4 may be a key determinant of rotavirus pathogenicity and a target for vaccine development. Twenty two G1P[6] rotaviruses from babies with and without diarrhea were comparatively analyzed along with reference strains and another 22 Taiwanese human rotaviruses of G and P combination types different from the G1P[6] type. The sequence variations in the NSP4 genes were studied by direct sequencing analysis of the amplicons of reverse transcription-PCR. Two genetic groups could be identified in this analysis. While the majority of these strains were closely related to the Wa strain, the G2 viruses were closely related to the S2 strain. Furthermore, phylogenetic analysis of the NSP4 gene among the G2 rotaviruses revealed three distinct lineages associated with DS-1, S2, and E210, respectively, as has been reported previously for the VP7 gene. However, we found no apparent correlation in the deduced amino acid sequences corresponding to the proposed enterotoxic peptide region between the rotaviruses recovered from individuals with and without diarrhea. The NSP4 gene product being a pathogenic determinant may not be a generalized phenomenon.

Enteric adenovirus infection in children in Taipei

Enteric adenoviruses (EAds), including type 40 (Ad40) and 41 (Ad41), can cause acute and severe diarrhea in young children. To delineate the epidemiological features of pediatric EAds infection in Taiwan, we conducted a retrospective study of all cases of EAds gastroenteritis in children treated at National Taiwan University Hospital for the period from July 1993 to December 1997. Stool samples were tested for the presence of Ad40 or Ad41 by enzyme immunoassay (EIA). A total of 64 cases of EAds infection in 63 children aged from 8 days to 81 months old with a median age of 9.5 months treated during the study period were identified. The male-to-female ratio was 1.63 (39/24). No obvious seasonal clustering of EAds cases was noted. Most patients (76.6%) were infected before the age of 2 years. Clinical features included diarrhea (96.9%), fever (54.7%), vomiting (45.3%), mild dehydration (43.8%), symptoms of upper respiratory tract infection (21.9%), and abdominal pain (12.5%). Analysis of fecal samples in patients with diarrhea showed watery diarrhea in 72.2%, diarrhea with mucus in 20%, diarrhea with blood in 3.1% and diarrhea with mucus and blood in 1.6 % of all patients. Nearly one-half (43.5%) of the patients had diarrhea for more than 7 days. Thirty-seven patients (57.8%) were hospitalized due to gastroenteritis or other unrelated diseases, and 11 patients (17.2%) acquired enteric adenovirus infection during hospitalization for other underlying disease. Twelve patients (18.8%) had mixed infections, which included rotavirus, respiratory syncytial virus (RSV) and Salmonella species. There were no deaths in this series. The findings of this study suggest that EAds are important etiologic microbes of pediatric gastroenteritis.

Rotavirus gastroenteritis in children: 5-year experience in a medical center

Rotavirus infection is the leading cause of childhood gastroenteritis. We retrospectively reviewed cases of rotavirus gastroenteritis at National Taiwan University Hospital from January 1993 to December 1997. During the study period there were 429 patients with rotavirus infection with ages ranging from 1 day to 16 years with a median of 13 months. The male-to-female ratio was 1.2:1. Infection occurred before the age of 2 years old in 76% of patients. The seasonal peak occurred in the late winter and early spring during 1993 to 1996, but the case number increased in late spring and summer in 1997. The G serotype of the rotavirus was identified in 302 patients (70%). Vomiting and dehydration developed more frequently following infection with G1 rotaviruses, while an increased frequency of seizures was noted following G2 infection; the differences were not statistically significant. One patient had two episodes of infection; the first one was caused by G1 rotavirus, and the strain causing the second infection could not be typed. In conclusion, the results suggest that there is a strong seasonal variation in the incidence and characteristics of rotavirus infection in Taipei area. The infections caused by G1 and G2 rotaviruses were clinically indistinguishable.

Quantitative competitive reverse transcription-PCR for quantification of dengue virus RNA

A quantitative competitive reverse transcription-PCR assay was developed to quantify dengue virus RNA in this study. The main features include a primer pair targeting a highly conserved region in the capsid and the addition of competing RNA that contains an internal deletion to provide a stringent internal control for quantification. It can be utilized to quantify RNA isolated from the four dengue virus serotypes but not RNA isolated from other flaviviruses, including Japanese encephalitis virus and hepatitis C virus, both prevalent in Asia. It can also be used to quantify dengue virus RNA isolated from the plasma of infected individuals. The sensitivity of the assay was estimated to be 10 to 50 copies of RNA per reaction, and twofold differences in virus titer are distinguishable. This assay is a convenient, sensitive, and accurate method for quantification and can be used to further understanding of the pathogenesis of dengue virus infection.

Reproductive and infectious risk factors for invasive cervical cancer in Taiwan

A community-based case-control study was carried out to assess multiple risk factors for invasive cervical cancer in Taiwan. All of 183 cases of pathologically confirmed cervical cancer cases and 293 healthy neighborhood controls were recruited from Taipei metropolitus. Healthy controls were matched with cervical cancer cases for age and residence. Multiple risk factors for cervical cancer were obtained from study subjects through standardized interviews according to a structured questionnaire. Serotiters of antibodies to Chlamydia trachomatis (CLT), human cytomegalovirus (HCMV) and human herpes simplex virus type 2 (HSV-2) were determined by enzyme-linked immunosorbent assay. Multiple logistic regression analysis were used to derive maximum likelihood estimates of multivariate-adjusted odds ratios (AOR) and confidence intervals (CI). After adjustment for potential risk factors, parity and number of vaginal delivery were associated with an increased risk of invasive cervical cancer. The higher the number of vaginal delivery, the higher the risk of developing cervical cancer (AOR = 6.2, 95% CI = 1.7-22.6 for 7 or more deliveries compared with 0-2 deliveries as the referent group). Increased cervical cancer risk was also significantly associated with the history of chronic cervicitis (AOR = 2.1, 95% CI = 1.1-3.8) and elevated serotiters of CLT (AOR = 7.0, 95% CI = 1.7-28.9), HCMV (AOR = 4.1, 95% CI = 1.5-11.3) and HSV-2 (AOR = 2.3, 95% CI = 1.1-4.6). The use of diaphragm for contraception was found to be associated with a decreased risk of cervical cancer (AOR = 0.4, 95% CI = 0.1-1.0).

Tuberculous pseudoaneurysm of the femoral artery: a case report

Pseudoaneurysm of the femoral artery is an extremely rare complication of tuberculosis. We present a case of tuberculous femoral pseudoaneurysm that was successfully treated with resection, direct anastomosis, and postoperative antituberculous chemotherapy.

Sequence analysis of VP1 and VP7 genes suggests occurrence of a reassortant of G2 rotavirus responsible for an epidemic of gastroenteritis

G2 rotavirus was prevalent in a 1993 epidemic of acute gastroenteritis in Taiwan. In this study, the genetic relationship among G2 rotavirus strains was analysed. The VP7 genes were amplified and sequenced. Except for one strain isolated in 1981, the nucleotide sequences of the VP7 genes of most of the G2 rotaviruses were very similar (identity > 97%) and were closely related to that of a Japanese G2 reference strain, S2. The genetic relatedness of G2 rotaviruses was analysed further by RNA-RNA hybridization. The genomes of the major G2 strains of 1993 did not hybridize well with those of the G2 strains of previous seasons in RNA segments 1, 6 and 7. Partial nucleotide sequences of the VP1 gene were analysed and appeared to be similar among the major G2 strains from the same epidemic (identity > 98%), whereas the identity of the VP1 genes of the major G2 strains of the 1993 epidemic to those of previous seasons was only about 84%. Since the numbers of mutations accumulated in the VP1 and VP7 genes over a period of 10 years were comparable, the significant change in the VP1 genes of the major strains of the 1993 epidemic suggests that these G2 rotaviruses had evolved by genetic reassortment.

Analysis of the steps involved in Dengue virus entry into host cells

The initial steps of dengue viral entry have been divided into adsorption and penetration using acid glycine treatment to inactivate extracellular virus after attachment to baby hamster kidney (BHK) cells but prior to penetration. First, we showed that virus infection was accomplished within 2 h after adsorption. Second, the assay was used to examine the properties of dengue envelope E protein-specific monoclonal antibodies (MAbs), lectins, and heparin. We found that three MAbs, 17-2, 46-9, and 51-3, may neutralize dengue 2 virus (DEN-2) through inhibition of not only viral attachment but also of penetration. However, one MAb, 56-3.1, interfered specifically with attachment. Therefore, the functional domains of E protein involved in attachment and penetration may be different. Moreover, studies with lectins indicated that carbohydrates, especially alpha-mannose residues, present on the virion glycoproteins may contribute to binding and penetration of the virus into BHK and mosquito C6/36 cells. Finally, virus infectivity was inhibited by heparin through its blocking effects at both virus attachment and penetration. This suggests that cell surface heparan sulfate functions in both viral attachment and penetration of DEN-2 virus. In conclusion, our results further elucidated some aspects of the dengue virus entry process.

Bilateral pathological femoral neck fractures secondary to ectopic parathyroid adenoma

A rare case of bilateral pathological femoral neck fractures secondary to ectopic parathyroid adenoma is reported. Both hip fractures were treated with closed reduction and internal fixation. The right hip fracture healed uneventfully, whereas the left hip fracture developed non-union that required subtrochanteric osteotomy and internal fixation and eventually healed. Neither hip developed avascular necrosis.

Enterovirus 71 from fatal and nonfatal cases of hand, foot and mouth disease epidemics in Malaysia, Japan and Taiwan in 1997-1998

Enterovirus 71 (EV71), one of the major causative agents for hand, foot and mouth disease (HFMD), is sometimes associated with severe central nervous system diseases. In 1997, in Malaysia and Japan, and in 1998 in Taiwan, there were HFMD epidemics involving sudden deaths among young children, and EV71 was isolated from the HFMD patients, including the fatal cases. The nucleotide sequences of each EV71 isolate were determined and compared by phylogenetical analysis. EV71 strains from previously reported epidemics belonged to genotype A-1, while those from recent epidemics could be divided into two genotypes, A-2 and B. In Malaysia, genotype A-2 was more prevalent, while in Japan and Taiwan, B genotype was more prevalent. Two isolates from fatal cases in Malaysia and one isolate from a fatal case in Japan were genotype A-2. However, all isolates from three fatal cases in Taiwan belonged to genotype B. The severity of the HFMD did not link directly to certain genotypes of EV71.

Study of Dengue virus infection in SCID mice engrafted with human K562 cells

Here we report that severe combined immunodeficient (SCID) mice engrafted with human K562 cells (K562-SCID mice) can be used as an animal model to study dengue virus (DEN) infection. After intratumor injection into K562 cell masses of PL046, a Taiwanese DEN-2 human isolate, the K562-SCID mice showed neurological signs of paralysis and died at approximately 2 weeks postinfection. In addition to being detected in the tumor masses, high virus titers were detected in the peripheral blood and the brain tissues, indicating that DEN had replicated in the infected K562-SCID mice. In contrast, the SCID mice were resistant to DEN infection and the mock-infected K562-SCID mice survived for over 3 months. These data illustrate that DEN infection contributed directly to the deaths of the infected K562-SCID mice. Other serotypes of DEN were also used to infect the K562-SCID mice, and the mortality rates of the infected mice varied with different challenge strains, suggesting the existence of diverse degrees of virulence among DENs. To determine whether a neutralizing antibody against DEN in vitro was also protective in vivo, the K562-SCID mice were challenged with DEN-2 and received antibody administration at the same time or 1 day earlier. Our results revealed that the antibody-treated mice exhibited a reduction in mortality and a delay of paralysis onset after DEN infection. In contrast to K562-SCID, the persistently DEN-infected K562 cells generated in vitro invariably failed to be implanted in the mice. It seems that in the early stage of implantation, a gamma interferon activated, nitric oxide-mediated anti-DEN effect might play a role in the innate immunity against DEN-infected cells. The system described herein offers an opportunity to explore DEN replication in vivo and to test various antiviral protocols in infected hosts.

Viral etiology of intussusception in Taiwanese childhood

BACKGROUND

Adenovirus infection and lymphoid hyperplasia have been associated with childhood intussusception. However, the extent of other viruses involved in this condition remains unclear. This prospective study investigates the relationship between some lymphotropic viruses and current childhood intussusception.

METHODS

Patients with intussusception encountered in a pediatric emergency department in a recent 3-year period were studied. Healthy infants and toddlers of comparable age served as controls. Throat and rectal viral cultures were performed in patients and controls. Viral antibodies against adenovirus, cytomegalovirus, human herpesvirus (HHV)-6, HHV-7 and Epstein-Barr virus (EBV) were tested in paired sera from the patients. Acute stage serum from each patient and mesenteric lymph nodes from patients requiring surgery were studied for the presence of adenovirus genome by PCR.

RESULTS

Twenty-seven of 61 (44.3%) intussusception patients, but only 2 of 52 (3.8%) healthy controls shed nonenteric adenovirus in throat and rectal specimens (P < 0.001). Of the 27 (74.1%) patients who shed adenovirus, 20 were older than 1 year old, whereas only 1 of 15 (6.7%) similarly aged patients in a previous study from the same area three decades ago did so (P = 0.001). Among 43 patients with available paired sera, acute primary viral infection was found in 17 (39.5%) by adenovirus, 4 (9.3%) by HHV-6, 5 (11.6%) by HHV-7, 2 (4.7%) by EBV and none by cytomegalovirus. Multiple viral infections occurred in 6 patients. Adenovirus genome was detected in 4 of 9 mesenteric lymph nodes and in only 3 of 60 (5%) acute phase sera.

CONCLUSIONS

Primary nonenteric adenovirus infection contributes to current childhood intussusception. Acute primary HHV-6, HHV-7 and EBV infections also play etiologic roles.

Thymic lymphoepithelioma-like carcinoma associated with thymoma in a patient with ocular myasthenia

A 65-year-old woman with ocular myasthenia was found to have three tumours in the anterior mediastinum, revealed by magnetic resonance imaging. All three lesions were radically resected. Histologically, one was a mixed-type thymoma, one a thymic lymphoepithelioma-like carcinoma, and the third had features of both these types. This appears to be the first reported case of coexisting thymic lymphoepithelioma-like carcinoma (TLC) and thymoma associated with ocular myasthenia.

Bronchial atresia associated with epibronchial right pulmonary artery and aberrant right middle lobe artery

We report a case of bronchial atresia associated with an epibronchial right pulmonary artery (ERPA) and an aberrant right middle lobe artery (ARMLA). CT showed a branching opacity, which was hyperintense on MR images, in the anterior segment of the right upper lobe with segmental hyperinflation and the ERPA. At surgery, the ARMLA was found to originate from the ERPA, crossing the anterior aspect of the right upper lobe bronchus. It is postulated that the ARMLA might have interfered with the normal bronchial development, leading to the development of segmental bronchial atresia.

Video-assisted thoracoscopic surgery for spontaneous hemopneumothorax

We operated on 403 patients with spontaneous pneumothorax between 1992 and 1996. Among these cases, 11 (2.7%) were spontaneous hemopneumothorax. The patients were all men, with ages ranging from 19 to 28 years (mean 23.8 years). The amount of blood drainage ranged from 650 to 2300 ml. Video-assisted thoracoscopic surgery was performed on these patients within 1 day after admission. The sources of bleeding were in the parietal and visceral pleurae of ruptured bullae (n = 6), the parietal pleura (n = 4), or the visceral pleura (n = 1). During operation, the ruptured bullae can be managed by an endoscopic linear stapler for a bullectomy, and the bleeding parietal pleura of the torn adhesion can be coagulated directly. Postoperative recovery of the 11 patients was uneventful, and they were discharged 4 to 10 days after the operation. No recurrence of spontaneous hemopneumothorax or any other complications occurred during follow-up. Thus spontaneous hemopneumothorax can be readily managed by cauterizing a bleeding site where appropriate, excising the apicocystic disease, and pleurodesis. As a minimally invasive method, video-assisted thoracoscopic surgery may be considered an initial treatment procedure in patients with spontaneous hemopneumothorax.

Identification of VP7 serotypes of human rotaviruses by enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction

Serotype specificity of human rotaviruses in Taiwan remained unclear. This study has established three methods for identification of G serotypes, fluorescent focus neutralization test (FFN), enzyme-linked immunosorbent assay by incorporating VP7 (G) serotype-specific monoclonal antibodies (ELISA-MAb) and reverse transcription-polymerase chain reaction (RT-PCR). FFN is a reference standard test for determination of G serotype. RT-PCR and ELISA-MAb were used for serotyping of rotavirus isolates and appeared to be accurate and more sensitive than FFN. Nevertheless, for serotyping the rotaviruses present in clinical stool samples, ELISA-MAb was not satisfactory, only 65.5% of the 264 specimens could be serotyped. The sensitivity of serotype prediction by RT-PCR was 89.4%. When both ELISA-MAb and RT-PCR were taken into account, G serotype could be predicted for 93.2% of the specimens. Serotyping results were comparable with the RNA profiles. Rotaviruses with similar RNA electrophoretic pattern had the same serotype specificity. RNA patterns could be used as a reference for prediction of serotypes. Because ELISA is easy to perform and less expensive, it would be suggested as a screening test. RT-PCR could be used for samples which could not be serotyped by ELISA-MAb. Furthermore, RT-PCR is especially valuable when serotype-specific monoclonal antibodies are not available.

Molecular cloning and expression of a fungal immunomodulatory protein, FIP-fve, from Flammulina velutipes

FIP-fve, a fungal immunomodulatory protein, was isolated from the fruiting bodies of the edible mushroom, Flammulina velutipes. FIP-fve was shown to stimulate blast-forming activity of human peripheral blood lymphocytes and gene expression of interleukin-2, interferon-gamma and tumor necrosis factor-alpha. Repeated administration of FIP-fve to mice inhibits the Arthur and systemic anaphylaxis reactions. FIP-fve cDNA was cloned and sequenced, and the amino acid sequence of FIP-fve deduced from the nucleotide sequence is identical to that previously determined by protein sequencing. FIP-fve cDNA was amplified by polymerase chain reaction, ligated into the expression vector, pGEX-2T, and expressed in Escherichia coli as a fusion protein of glutathione S-transferase (GST) and FIP-fve. The GST-FIP-fve fusion protein was soluble, and the yield of recombinant FIP-fve was about 5 mg/L of induced culture. The recombinant FIP-fve was obtained by cleaving the GST-FIP-fve fusion protein with thrombin and purifing to homogeneity. The recombinant FIP-fve had about 50% of the immunomodulatory activity of the native FIP-fve.

Transaortic patch angioplasty for left main coronary artery occlusion

Isolated total occlusion of the left main coronary artery is rare, and may be conventionally treated by standard bypass surgery. We describe a 54-year-old woman with isolated left main coronary artery disease presenting as unstable angina of 1 week's duration. She was treated with transaortic autologous pericardial patch angioplasty. Postoperative coronary angiography showed a widely patent left main coronary artery. She was angina-free 5 months postoperatively. In selected patients, this technique offers a valuable alternative to coronary artery bypass with the advantage of restoring more physiologic perfusion to the coronary tree.

Fip-vvo, a new fungal immunomodulatory protein isolated from Volvariella volvacea

A new fungal immunomodulatory protein (Fip) has been purified from the edible mushroom, Volvariella volvacea, and designated Fip-vvo. Analysis of the purified protein by SDS/PAGE followed by Coomassie Blue staining demonstrated that Fip-vvo is a single polypeptide with an apparent molecular mass of 15 kDa. Periodic acid/Schiff staining showed that this single polypeptide lacks carbohydrates. Using an in vitro bioassay measuring blast-formation stimulatory activity, Fip-vvo was shown to stimulate the maximum proliferation of human peripheral blood lymphocytes at a concentration of 5 microg/ml. Fip-vvo was capable of agglutinating rat red blood cells. Neither haemagglutination nor mitogenic activities were inhibited by mono- or dimeric sugars. In vivo, repeat administration of Fip-vvo greatly reduced the production of BSA-induced Arthus reaction in mice, whereas little effect was observed on the prevention of systemic anaphylaxis reactions. The selectively enhanced transcriptional expression of interleukin (IL)-2, IL-4, interferon-gamma, tumour necrosis factor-alpha, lymphotoxin and IL-2 receptor by Fip-vvo was also demonstrated by reverse transcriptase-PCR. This finding suggests that Fip-vvo exerts its immunomodulatory effects via cytokine regulation. In addition, the complete amino acid sequence of Fip-vvo was obtained by direct protein sequencing. This protein consists of 112 amino acid residues with a blocked N-terminal end and has a calculated molecular mass of 12667 Da not including the N-terminal blocking group. By gel filtration analysis, Fip-vvo exhibited a molecular mass of 26 kDa for the native molecules in PBS. This result indicates that native Fip-vvo is most likely a non-covalently associated homodimeric molecule.

Isolated common iliac artery occlusion secondary to atherosclerotic plaque rupture from blunt abdominal trauma: case report and review of the literature

Traumatic isolated common iliac artery occlusion is unusual. Only rare cases of common iliac arterial injuries resulting from blunt abdominal trauma have been reported, and most of them were attributed to the seat-belt syndrome and associated with visceral organ perforation or pelvic fracture. We reported an unusual isolated common iliac artery occlusion secondary to atherosclerotic plaque rupture from blunt abdominal compressive trauma without other visceral injury. This case presented with acute limb ischemia and paralysis that was successfully treated by thromboendarterectomy. The symptoms and signs, surgical modalities, and associated injuries were reported and the literature was also reviewed.

Seroepidemiology of Hantaan virus infection in Taiwan

In order to investigate the infection rate of Hantaan virus in Taiwan, a total of 6,536 human serum samples were collected from residents, selected by stratified random sampling, from 19 townships covering four different ethnic groups: Aborigines, Fukien Taiwanese, Hakka Taiwanese, and Mainland Chinese. Serum samples were screened for Hantaan virus antibodies by indirect immunofluorescence. The prototype Hantaan virus (76/118)-infected Vero E6 cells were used as the viral antigen for the antibody detection. Among 6,536 human serum samples, 403 (6.2%) samples had Hantaan virus antibodies. The seropositive rates for males and females were 6.1% and 6.2%, respectively. A higher seropositive rate was found among Aborigines on the Orchid Islets (11.5%) and Fukien Taiwanese on the Penghu Islets (11.6%), while the lowest rate was observed among Hakka Taiwanese in the south of Taiwan (2.5%). In comparing with different ethnic groups, the highest prevalence was found among Fukien Taiwanese (8.1%) and the lowest among Mainland Chinese (4.9%). Among the different geographical areas, the highest positive rate was found in western Taiwan (7.1%) and the lowest in southern Taiwan (5.4%). Hantaan virus antibodies were also detected in 22 of 548 (4.0%) rat serum samples. The highest seropositive rate was found in rat sera collected from the Orchid Islets (21.4%). None of the rat sera collected from Hsinchu, Miaoli, Changhua, Nantu, Yunlin, Chiayi, Tainan, and Penghu Counties were positive. Hantaan virus antibodies were found in rats: Rattus rattus (20%), Bandicota indica (9.0%), Rattus norvegicus (8.3%), Bandicota nemorivaga (6.3%), Rattus losea (4.2%), and Apodemus agrarius (1.6%). Hantaan virus antibodies were not detected in rat sera collected from species of Rattus coxinga, Rattus culturatus, Mus musculus, Mus caroli, Suncus murinus, and Apodemus semotus. The results show that the Hantaan or Hantaan-related virus exists and is distributed widely in both human and rats in Taiwan.

Study of young women vaccinated against rubella virus for 10 years in Taiwan

Since the licensing of the rubella virus vaccine (RA 27/3 strain) in 1979, clinical studies on the RA 27/3 strain vaccine, which gives rise to high titer antibody, have been reported. In the present study, this vaccine was used to examine the immune response in young women. Volunteers without the previous immunity to rubella virus screened by hemagglutination inhibition (HAI), latex agglutination (LA), fluorescence immunoassay (FIA) and solid-phase immunoassay (SPIA) tests were injected with Rudivax vaccine or Meruvax II vaccine. Adverse reactions occurred between 10 and 20 days after vaccination in 30% of the volunteers. After 28-35 days, vaccinees developed antibodies against rubella virus. The titer of rubella antibody reached it's peak from the 40th day through the 100th day. One year after vaccination, the geometric mean titer (GMT) of rubella virus antibody still remained over 1 : 64 (HAI) and 1 : 38.2 (FIA), and SPIA IgG RI mean was 2.80. Two years later, the antibody titers were 1 : 52 by HAI and 1 : 32.1 by FIA, and SPIA IgG RI mean was 2.75. After 5 years, the antibody titers were 1 : 48.6 (HAI) and 1 : 28.2 (FIA), and SPIA IgG RI mean was 2.74. After 10 years, the anti-rubella virus antibody titers were 1 : 38.9 (HAI) and 1 : 25.1 (FIA), and SPIA IgG RI mean was 2.42. LA antibody still remained seropositive. In conclusion, the rubella vaccine RA 27/3 is safe and efficient, and it is applicable for the control of the rubella in Taiwan.

Prolonged circulatory arrest in moderate hypothermia with retrograde cerebral perfusion. Is brain ischemic?

BACKGROUND

Circulatory arrest (CA), which provides a bloodless field and good visualization without the need of aortic cross-clamp, is commonly used to facilitate repair of aortic lesions. However, extended periods of CA may impair cerebral metabolism and cause ischemic injury. Studies were performed to evaluate the efficacy of retrograde cerebral perfusion (RCP) in protecting the brain from ischemic injury during a prolonged period of CA in moderate hypothermia.

METHODS AND RESULTS

Twenty-three patients (18 men and 5 women) were operated on for aortic lesions (17 acute type A aortic dissection and 6 chronic type A aortic dissection with Marfan's syndrome). The aortic operations were performed with CA (58 to 104 minutes; mean +/- SD, 75 +/- 12 minutes) at a rectal temperature of 23.3 +/- 0.5 degrees C (21 degrees C to 25 degrees C). For RCP, cold (14 degrees C to 18 degrees C) oxygenated blood (300 mL/min) was pumped to the superior vena cava with internal jugular venous pressure of 15 +/- 5 mm Hg. The cardiopulmonary bypass time was 157 +/- 18 minutes. Cortical blood flow during RCP detected by subdural laser Doppler probe was 10 +/- 5% of baseline. Percent oxygen extraction and pyruvate and lactate levels (26 +/- 2% and 0.43 +/- 0.17 and 45 +/- 16 mg/dI) were insignificantly different from those before CA (28 +/- 3% and 0.71 +/- 0.08 and 62 +/- 20 mg/dL, P > .05). Creatine kinase-BB isoenzyme was undetectable. All but 1 patient survived the operation (95.5%) and woke up without neurological deficit. Follow-up (mean, 13 months) was complete in all survivors. There were no late deaths. Cerebral functional studies performed 3 months after discharge showed results insignificantly different from those of the normal control subjects.

CONCLUSIONS

There is no evidence of ischemia of the brain during prolonged moderate hypothermic CA with the aid of RCP. Retrograde cerebral perfusion effectively extends the safe time of CA. Deep hypothermia during CA seems unnecessary.

Ectopic parathyroid adenoma with severe hungry bone syndrome: a case report

The presentation rate of ectopic mediastinal parathyroid adenoma is about 5 approximately 22%. Ectopic parathyroid adenoma is a common etiology of failed parathyroid surgery as well as a diagnostic challenge to clinicians. We reported a case of ectopic mediastinal parathyroid adenoma. A 20-year-old girl presented with arthralgia for 2 years before hyperparathyroidism was diagnosed. Parathyroid ultrasonography failed to find the lesion, but a vivid uptake in the superior mediastinum was discovered by thallium-201 (Tl-201) and technetium-99m-sestamibi (Tc-99m-MIBI) images. Removal of the ectopic adenoma resulted in severe Hungry bone syndrome, which required a large amount of calcium and phosphorous supply. Later, the patient suffered from bilateral femoral neck fracture due to marked osteoporosis. Bone mineral density study revealed marked increase of fracture risk. Although bone disorder is rare in cases of hyperparathyroidism nowadays, it still should be considered in patients with arthritis of unknown etiology like our case. Early diagnosis and treatment can reduce the morbidity.

Human cytomegalovirus as a potential etiologic agent in recurrent aphthous ulcers and Behçet's disease

In a preliminary study on anti-human cytomegalovirus (HCMV) antibody (Ab) by ELISA, the serum anti-HCMV/IgG Ab concentrations in 22 patients with recurrent aphthous ulcers (RAU) in the remission stage were found to be significantly higher than in 22 control subjects (121 +/- 42 vs 100 +/- 27, P < 0.05) and in 39 patients with RAU in the active stage (121 +/- 42 vs 88 +/- 45, P < 0.01). Therefore, the potential of HCMV as an etiologic agent in RAU was proposed and studies using the polymerase chain reaction (PCR) and in situ hybridization (ISH) have been performed to investigate the possible presence of HCMV DNA in pre-ulcerative oral aphthous lesions in patients with RAU or Behçet's disease (BD) of the mucocutaneous type. For this purpose, formalin-fixed biopsy specimens were obtained from 13 pre-ulcerative oral aphthous lesions, 2 samples of normal oral mucosa and 1 ileal mucosal lesion from 9 RAU patients and 4 BD patients. Five specimens of normal oral mucosa from 5 normal control subjects and 12 specimens of oral erosive or ulcerative lesions from 12 patients with erosive lichen planus (ELP) were also included. By PCR, HCMV DNA was detected in 5 of the 13 (38.5%) pre-ulcerative oral aphthous lesions, 3 from RAU patients and 2 from BD patients. The ileal mucosa specimen was also HCMV DNA-positive, whereas HCMV DNA was not demonstrated in any of the 7 specimens of normal oral mucosa from RAU patients and normal control subjects; 12 specimens of oral lesions from ELP patients were similarly negative. ISH did not detect HCMV DNA in any of the biopsy specimens from RAU patients and control subjects. Our findings suggest that HCMV may be an etiologic agent in some cases of RAU and BD.

Adult primary IgA nephropathy and common viral infections

Serum samples obtained from 69 histopathologically proven IgA nephropathy (IgAN) patients and 563 healthy controls were examined to evaluate the association between IgAN and common viral infections. Antibody titres to cytomegalovirus (CMV), herpes simplex virus (HSV), Vericella-Zoster virus (VZV), Influenza A (Inf. A) and Influenza B (Inf. B) viruses were determined, using a complement fixation test. The viral antibody titres were considered to be positive with dilutions of 1:8 or greater except for Epstein-Barr virus (EBV), studied using immunofluorescence, which was considered to be positive with dilutions of 1:10 or greater. The positive rate of Inf. B antibody in IgAN patients was significantly lower than that in controls. The frequency of positive CMV antibody titres was higher than for controls, but with only borderline statistical significance (P = 0.059). The frequency of positive CMV and Inf. B titres was compared by age in IgAN patients and controls. but showed no statistically significant difference. Comparisons of percentage distributions at each antibody dilution level to the common virus of IgAN patients and controls, but showed no statistically significant difference. Comparisons of percentage distributions at each antibody dilution level to the common virus of IgAN patients and controls were made; however, none showed a statistically significant difference. In conclusion, no absolutely higher frequency of positive antibody titres for common viruses was demonstrated in IgAN patients in this study.

Unruptured sinus of Valsalva aneurysm with right ventricular outflow tract obstruction associated with ventricular septal defect

We describe an aneurysm originating from the right sinus of Valsalva, with right ventricular outflow tract obstruction associated with ventricular septal defect, in a 9-year-old boy. Diagnosis was made by echocardiography and cardiac catheterization. Successful surgical repair of ventricular septal defect and aortic valvuloplasty resulted in symptomatic improvement.

Alkaline protease catalysis of a secondary amine to form a peptide bond

Procedures for peptide bond formation using esters of L-amino acids as the acyl donor and secondary amines such as derivatives of D- or L-proline, or pyroglutamic acid as the nucleophile in anhydrous 2-methyl-2-propanol catalyzed by alcalase or subtilisin Carlsberg have been developed. Kinetic studies have shown that all secondary amines tested had catalytic efficiencies (kcat/km) in the range 84-423 min-1 M-1. Both enzymes have identical catalytic properties. The selectivity of the enzyme-catalyzed reaction in 2-methyl-2-propanol shows that at the s-1 subsite of the enzyme only L-amino acids are substrates as acyl donors, and at the s-1' subsite both D- and L-amino acids are substrates. Optimal conditions for preparing precursors of the renin inhibitors Z-Ala-Pro-OBzl, Z-Lys(Z)-Pro-OBzl and Z-Lys(TFA)-Pro-OBzl were studied.

A new fungal immunomodulatory protein, FIP-fve isolated from the edible mushroom, Flammulina velutipes and its complete amino acid sequence

A new fungal immunomodulatory protein (FIP-fve) has been isolated and purified from the edible golden needle mushroom (Flammulina velutipes). The apparent molecular mass of FIP-fve determined by SDS/PAGE agrees well with the value of 12704 Da calculated from its amino acid composition and sequence. The complete amino acid sequence of FIP-fve was elucidated by protein sequencing techniques. FIP-fve consists of 114 amino acid residues with an acetylated amino end, and lacks methionine, half-cystine and histidine residues. FIP-fve was able to hemagglutinate human red blood cells. The immunomodulatory activity of FIP-fve was demonstrated by its stimulatory activity toward human peripheral blood lymphocytes, and its suppression of systemic anaphylaxis reactions and local swelling of mouse footpads. FIP-fve was found to enhance the transcriptional expression of interleukin-2 and interferon-gamma.

Outbreak of aseptic meningitis in Taipei in spring 1993

An outbreak of aseptic meningitis in the Taipei area occurred from January to August 1993. A total of 114 cases were identified by cerebrospinal fluid (CSF) examination at National Taiwan University Hospital. Most of the cases were found from February to May 1993. The peak of age distribution was 3 to 11 years. The male-to-female ratio was 2.1 to 1. Most patients had fever, headache, and vomiting and nausea. On initial CSF examination, protein concentrations > 400 mg/L were noted in 38 of 93 CSF samples, while 19 of 70 initial samples had hypoglycorrhachia (CSF/serum glucose ratio < 0.5). CSF white cell counts of the initial lumbar puncture were 0-9 x 10(6) cells/L in 4 patients, 10-99 x 10(6) cells/L in 42 patients, 100-199 x 10(6) cells/L in 27 patients, 200-499 x 10(6) cells/L in 24 patients, 500-999 x 10(6) cells/L in 12 patients and > or = 1,000 x 10(6) cells/L in 5 patients. Polymorphonuclear cells predominated in 73 of 114 cases. Viral cultures from CSF, throat swabs and rectal swabs were done with a majority yielding enteroviruses. Enterovirus as a definite etiology was found in 58 of 114 cases and was the presumptive etiology in 15 of 114 cases. The serotypes of the enteroviruses isolated were mostly echovirus type 30. All patients recovered without obvious sequelae.

Enhancement of endothelium-dependent contraction of the canine coronary artery by UW solution

University of Wisconsin (UW) solution has been used almost routinely in the preservation of the hepatic, pancreatic, renal, and cardiac allografts. However, its effect on vascular endothelium is unknown. Experiments were designed to evaluate its effect on canine coronary endothelium. Canine coronary arteries (n = 8 in each group) were preserved in cold (4 degrees C) UW solution (group 1) and physiological solution (group 2) for 6 hr immediately after harvesting. Segments of preserved and control (group 3) coronary arteries with or without endothelium were then suspended in organ chambers to measure isometric force. Perfusate hypoxia (pO2 30 +/- 5 mmHg) caused endothelium-dependent contraction in the arteries of all 3 groups. However, vascular segments with endothelium of group 1 exhibited hypoxic contractions (107 +/- 26% of the initial tension contracted by prostaglandin F2 alpha 2 x 10(-6) mol/L, P < 0.05) that were significantly greater than those of the group 2 and group 3 segments with endothelium (25 +/- 5% and 20 +/- 4%). The hypoxic contraction in arteries of group 1 could be attenuated by NG-monomethyl-L-arginine (L-NMMA), the blocker of endothelial cell synthesis of the nitric oxide from L-arginine. The action of L-NMMA could be reversed by L-arginine but not D-arginine. Endothelium-dependent relaxation of coronary endothelium to acetylcholine and adenosine diphosphate and endothelium-independent relaxation and contraction of coronary smooth muscle were not altered by the UW solution. After preservation with the UW solution, endothelium-dependent contraction of the canine coronary arteries, occurs by L-arginine-dependent pathway, is enhanced. This augmentation by the UW solution would favor vasospasm after transplantation.

Protection of the brain by retrograde cerebral perfusion during circulatory arrest

Hypothermic circulatory arrest is commonly used to facilitate repair of complex congenital heart defects and aortic lesions and for complex neurosurgical procedures. However, extended periods of circulatory arrest may impair cerebral metabolism and cause ischemic injury. Retrograde cerebral perfusion has been applied recently in aortic surgery to protect the brain. From January 1991 to December 1993, 29 patients underwent emergency operations to repair acute type A aortic dissection with the aid of hypothermic circulatory arrest. Six patients received hypothermic circulatory arrest without retrograde cerebral perfusion with a rectal temperature of 16.4 degrees +/- 0.9 degrees C (mean +/- standard error of the mean, group 1). Retrograde cerebral perfusion during hypothermic circulatory arrest was performed in 15 patients with a rectal temperature of 15.9 degrees +/- 0.5 degrees C (group 2) and in eight patients with a rectal temperature of 21.7 degrees +/- 0.8 degrees C (group 3). The hypothermic circulatory arrest times were 25 +/- 4, 42 +/- 4, and 63 +/- 6 minutes, respectively (p < 0.05). The cardiopulmonary bypass times were 173 +/- 5, 184 +/- 7, and 143 +/- 6 minutes, respectively (p < 0.05). All patients survived the operation and regained consciousness with no neurologic defects. Follow-up (mean 23.2, 14.5, and 5.1 months, respectively) was complete in all patients except one. This patient, from group 2, was killed in a road traffic accident 12 months after the operation. Our experience suggests that retrograde cerebral perfusion can effectively protect the brain from ischemic injury and extend the safe period of hypothermic circulatory arrest. With the aid of retrograde cerebral perfusion, prolonged circulatory arrest can probably be performed safely with moderate hypothermia.

Prenatal diagnosis of congenital rubella infection from maternal rubella in Taiwan

OBJECTIVE

To determine the frequency of intrauterine rubella infection in Taiwan.

METHODS

One hundred three pregnant women with evidence of rubella infection were enrolled. Congenital rubella infection was diagnosed by testing specific immunoglobulin (Ig) M in fetal cord serum obtained from funipuncture or amniotic fluid culture. The fetal outcomes were evaluated by ultrasonic examination, specific antibody detection in cord blood at birth, and complete physical examination during early childhood.

RESULTS

Prenatal diagnosis was possible in 95 of 103 fetuses, 93 by funipuncture and two by amniocentesis. Five intrauterine rubella infections were detected prenatally, and another one was diagnosed after birth. The intrauterine infection rates were 10.0, 11.8, 2.9, and 6.5% after maternal infection at 1-10, 11-14, 15-19, and 20-29 gestational weeks, respectively. Among the six fetuses with serologic evidence of congenital infection, one had congenital rubella syndrome with sensorineural deafness, two were terminated during the second trimester, two others were normal, and one was lost to follow-up. With the exception of the infant with clinical congenital rubella syndrome, no evidence of rubella defects was found in the other 81 children who received follow-up to 2-4 years old.

CONCLUSION

The risk of congenital rubella infection in seropositive pregnant women is relatively low in Taiwan.

Surgical treatment of acute type A aortic dissection with an intraluminal sutureless graft

The surgical treatment of acute type A aortic dissection remains a great challenge to all cardiac surgeons. From January 1991 to June 1993, 21 consecutive patients (13 men and eight women, aged 34 to 74 years) underwent emergency operations to repair acute type A aortic dissection, with the aid of hypothermic circulatory arrest. The intima tear was located in the ascending aorta in 13 patients, in the aortic arch in five patients, and in the descending aorta in three patients. The dissected ascending aorta was replaced with sutureless, intraluminal vascular grafts in all 21 patients. The intima tears in the aortic arch of five patients were primarily repaired. Modified Cabrol's shunts were created in seven patients for hemostasis, and Dacron grafts were used to wrap the ascending aorta in 18 patients. Retrograde cerebral perfusion during circulatory arrest was performed on 15 patients. The circulatory arrest time was 37 +/- 10 minutes (mean +/- SD). All patients survived the operation and regained consciousness in the early postoperative period without neurologic deficit. Post-treatment follow-ups (mean, 18.2 months) were completed in all patients except one, who died 12 months after the operation as a result of a traffic accident. All of the surviving patients are doing well without any further aortic operations. Our experience suggests that surgical repair of the acute type A aortic dissection can be a simple and safe procedure if sutureless intraluminal grafts are used and hypothermic circulatory arrest and retrograde cerebral perfusion are utilized.

Differential diagnosis of extrahepatic biliary atresia from neonatal hepatitis: a prospective study

The clinical presentations of cholestasis in infancy caused by neonatal hepatitis and biliary atresia are very similar. Diagnosis may be difficult on many occasions, but the surgical treatment of biliary atresia should be performed as early as possible. We established a 3-day workup protocol for the differential diagnosis of biliary atresia and neonatal hepatitis and compared the diagnostic accuracy, sensitivity, specificity, and predictive values of various methods. One hundred and twenty-six infants, including 84 with neonatal hepatitis (age, 65.1 +/- 24.1 days) and 42 with biliary atresia (age, 60.3 +/- 31.1 days), were studied prospectively from July 1982 to December 1990. The diagnostic accuracy of various methods was as follows: liver histology, 96.8%; color of duodenal juice, 91.6%; peak radioisotope count in duodenal juice, 84.2%; ultrasonographic examination of the hepatobiliary system, 80.2%; and persistence of clay-colored stool, 80.2%. After stepwise logistic regression, the diagnostic methods of significance were liver biopsy, color of duodenal juice, abdominal ultrasonography, and stool color. However, stool color and the onset of jaundice could not differentiate severe neonatal hepatitis from biliary atresia. The diagnostic methods of significance then were liver biopsy and duodenal juice color. With this 3-day protocol, no biliary atresia was missed although four cases of neonatal hepatitis were misdiagnosed, resulting in unnecessary laparotomy; we found an overall diagnostic accuracy of 96.8%. We conclude that this 3-day diagnostic protocol is very helpful in the differential diagnosis of neonatal hepatitis and biliary atresia. Liver histologic examination is the most reliable single test for the differential diagnosis.

Femoro-arterial bypass using Gott shunt in liver transplantation following severe hepatic trauma

The heparinized-coated tube is widely used for arterial bypass, mainly in patients with aneurysms or trauma of the thoracic aorta. Its application in venous bypass was less frequent. We report a 26-year-old woman who sustained blunt abdominal injury which resulted in complete severance of the suprahepatic hepatic vein and multiple partial lacerations of the inferior vena cava. For hemostasis, total hepatectomy with interruption of the inferior vena cava was performed. During the anhepatic phase, end-to-end portocaval anastomosis and a bypass shunt using 9 mm Gott tube from the right femoral vein to the right atrium were set up for veno-venous bypass. Orthotopic liver transplantation was performed later. Gott tube was placed for 18 hours with good venous return. We concluded that heparinized-coated tube is good for veno-venous bypass with the following advantages: 1) simple operative procedure, 2) enough flexibility to be kept out of the operative field, 3) no anticoagulant is necessary, consequently less bleeding resulted.

Surgical management of thrombotic disc valve

Thrombotic obstruction, a rare but often fatal complication of cardiac valve prostheses, appears to occur more frequently in tilting-disc valves than in other valve designs. Its diagnosis and surgical treatment remain a challenge. Ten consecutive patients who had thrombosis of a tilting-disc valve prosthesis were treated in Chang Gung Memorial Hospital from November 1982 to August 1990. Preoperative clinical features, including exertional dyspnea, new murmur, and absence of a metallic click from the prosthetic valve, occurred in all of the patients. Symptoms were present for 1 week or more before reoperation in 70% of the patients; nevertheless, many patients were referred only after acute exacerbation of heart failure and development of pulmonary edema. Echocardiography confirmed prosthetic valve malfunction in 90% of the patients. One unconfirmed case was later documented by cardiac catheterization. Anticoagulant therapy was in the therapeutic range for only half of the patients at the time of admission. Prompt reoperation was performed for thrombectomy (8 patients, all survived) or valve replacement (2 patients, one death). Long-term outcome was satisfactory in all survivors with a mean follow-up of 31.6 months. These findings emphasize the importance of considering the diagnosis of thrombosis in patients with mechanical heart valve prostheses who are first seen with nonspecific symptoms and minor changes of their physical findings. The diagnosis could be easily made by echocardiography. Thrombectomy is an easy, fast, and safe procedure, especially for these critically ill patients.

Seroepidemiology and evaluation of passive surveillance during 1988-1989 measles outbreak in Taiwan

A seroepidemiological study was carried out to explore the risk factors of a measles outbreak that occurred among school children at a rural village (Li-Tse) in Taiwan. Among the 1166 participants, the percentage susceptible before the outbreak was 10.5% (122/1158) which was estimated as the sum of measles IgG-negative (29/1158) and IgM-positive (93/1166) individuals. Among 340 vaccinated children, 16 (4.7%) were measles IgM-positive and 10 (2.9%) were measles IgG-negative; therefore the vaccine failure rate was estimated to be 7.6% (26/340) and vaccine efficacy was 79.7% (95% confidence interval [CI] : 65.0-88.5). The most important risk factors for acquiring measles infection were the presence of other measles cases in the family (Odds Ratio [OR] = 32.5, P = 0.002) and the presence of more than two cases in a class (OR = 29.1, P = 0.003). The physician reporting rate was 6.1% (4/66), and the sensitivity of passive measles surveillance was only 4.3% (4/93) by active serosurvey. A concomitant rubella epidemic also amplified the inaccuracy of a passive reporting system based only on clinical diagnosis. Five children developed measles IgM but did not experience any symptoms, indicating that asymptomatic measles infection can occur. Our experience has highlighted three important areas for future measles elimination: (1) the need for serological evaluation of vaccinees, particularly those who were born during the introduction of mass immunization; (2) improvement in measles vaccine efficacy; and (3) further investigations on the role of asymptomatic transmission and susceptibles who remain after mass immunization.

Polymerase chain reaction to detect human cytomegalovirus in livers of infants with neonatal hepatitis

Neonatal hepatitis is closely related to human cytomegalovirus infection in Taiwan, a conclusion based on serological and urine culture studies. To obtain more direct evidence further relating cytomegalovirus to the pathogenesis of neonatal hepatitis, the cytomegalovirus genome was studied in the liver tissues of 50 infants with neonatal hepatitis using the polymerase chain reaction (PCR). Liver tissues from 26 infants with biliary atresia and another 30 infants and children with diagnoses other than neonatal hepatitis, cholestasis, or hepatitis were also studied for comparison. Sequences from the immediate early gene 1 and 2 regions were used as primers. The liver tissues from 23 (46%) of the 50 infants with neonatal hepatitis were positive for cytomegalovirus genome, whereas those of 2 of the 26 infants with biliary atresia and none of the liver tissues from 30 infants and children without neonatal hepatitis were positive for cytomegalovirus genome, by PCR. The results of PCR correlated well with that of serology and urine culture. This study provides further evidence of cytomegalovirus in the pathogenesis of neonatal hepatitis.

[Valve replacement for aortic stenosis]

We retrospectively reviewed 122 consecutive patients with aortic stenosis from January 1977 to December 1990. There were 68 male and 54 female patients. Their age ranged from 5 to 73 years old (47 +/- 16, mean +/- SD). Sixty eight patients also had associated mitral valve lesion, 13 patients had tricuspid valve lesion, and 3 patients had coronary artery disease. Aortic valve replacement was performed on all patients. Mechanical valves were implanted in 86 cases and tissue valves in 36 cases. Associated procedures were performed in 54 cases: mitral valve replacement in 34 cases, mitral valve repair in 18 cases and coronary artery bypass grafting in 2 cases. A bicuspid aortic valve was found in 20 cases (16.4%). Hospital mortality was 4.9% (6 cases). Follow-up was completed in 95% of the surviving cases (110 cases). The survival rate was 82 +/- 3% at 13 years and redo-free rate was 73 +/- 8% at 13 years. Seven cases required redo operation, due to tissue valve degeneration in 5 and thrombosis of the mechanical valve in 2. All 7 patients survived. Late death occurred in 6 cases: 3 from malignancy, 2 from stroke and 1 from ventricular arrhythmia. We concluded that valve replacement for aortic stenosis is a safe and satisfactory procedure with good long-term results.

Changing seroepidemiological patterns of cytomegalovirus infection in children in Taiwan from 1984 to 1989

The prevalence of cytomegalovirus (CMV) antibody was studied in 966 children in 1984 and 927 children in 1989. The overall prevalence rate of CMV antibody was 59% for children in 1984 and 46% for children in 1989 (P less than 0.05). In both study years, the prevalence rate of CMV antibody was about 70% in infants under 6 months of age, declined to a trough between the ages of 6 and 12 months, and then increased to 40-50% between 1 and 4 years of age. The rate of CMV antibody for children above 4 years in 1984 increased steadily with age and reached 82% by 12 years. In contrast, the prevalence rate in 1989 remained at the level of 40-50% from age 4 to 10 years. It was followed by a sharp increase after 10 years of age and reached 84% at 12 years old. The seropositive rate in each of the 5-, 6-, 8-, 9-, and 10-year-old groups was higher in 1984 than that in 1989. These observations indicated that the prevalence rate of CMV antibody is decreasing in children. This change may be related to various socioeconomic factors, especially the less crowded family conditions in recent years.