Symptomatic patent ductus arteriosus in very low birth weight infants

BACKGROUND

Premature neonatal survival rates have increased significantly. The diagnosis of patent ductus arteriosus (PDA) has also increased. In this paper, we present our experience of incidence, clinical features and outcome of the treatment of symptomatic PDA in very low birth weight infants.

METHODS

From January 1990 to December 1995, 181 premature infants with birth weight less than 1,500 g were admitted to the Neonatal Intensive Care Unit (NICU) of Veterans General Hospital-Taipei. Thirty-seven were diagnosed to have symptomatic PDA. By reviewing hospital records, the clinical features and outcome of treatment of these infants were analyzed retrospectively.

RESULTS

The incidence of symptomatic PDA was 20.9% and 21.4% in infants with birth weight less than or equal to 1,000 g, 1,001-1,500 g, respectively. The mean age at diagnosis of infants with symptomatic PDA was significantly less than those without symptoms (3.6 +/- 2.9 days vs 9.6 +/- 17.2 days, p = 0.044, 95% CI = 0.2-11.8). With fluid restriction and diuretic therapy, asymptomatic patients had a higher spontaneous ductal closure rate than symptomatic patients (58.3% vs 10.8%, p < 0.001, 95% CI = 17.9-77.1%). Thirty-two (97.0%) infants with symptomatic PDA responded to indomethacin therapy. However, four infants (12.1%) had recurrence. These four infants and a nonresponder received surgical ligation of the PDA and survived. There were four deaths. The reasons for death were respiratory failure in two, sepsis in one and necrotizing enterocolitis with intestinal perforation in one.

CONCLUSIONS

Conservative medical management such as fluid restriction and diuretics are often adequate for asymptomatic PDA. However, since symptomatic PDA tends not to close spontaneously, patients should be treated with indomethacin if ductal shunting compromises cardiopulmonary function.

Neonatal myocardial infarction: a case report

Neonatal myocardial infarction is a rare disorder. It occurs in association with congenital heart disease or coronary artery abnormalities. In the absence of structural heart disease, perinatal asphyxia and coronary artery thromboembolism have been reported as common etiologies. Whether the Coxsackie B viral group has a causal role in adult myocardial infarction remains controversial. We report herein a case of neonatal myocardial infarction without known congenital heart disease, in whom perinatal Coxsackie B viral infection was suspected to be the underlying cause. However, definite evidence indicating a causal relationship between neonatal myocardial infarction and Coxsackie B viral infection was lacking in this case.

Metabolic detriment in donor heart valves induced by ischemia and cryopreservation

BACKGROUND

The injury resulting from postmortem ischemia is a critical deterrent to the availability of donor valves. Using the reduction of XTT-tetrazolium salt as a marker of metabolic sequelae, we assessed the injurious effect of ischemia and the metabolic sequelae in 156 porcine semilunar leaflets.

METHODS

The leaflets were randomly allocated to noncryoprocessed (n = 72) or cryoprocessed (n = 72) groups. At each preservation temperature of 4 degrees C, 24 degrees C, or 37 degrees C, 24 leaflets each were exposed to one of four storage periods of 9, 17, 30, or 60 hours. Twelve fresh aortic leaflets served as baseline reference samples.

RESULTS

There was a progressive loss in the metabolic functioning of valve leaflet cells in both noncryopreserved and cryopreserved tissue as the storage times increased. Cryopreserved tissue showed a greater loss of function than noncryopreserved tissue did. The metabolic injury was mainly a consequence of cryoprocessing. The greatest loss in metabolic functioning occurred in the valves stored for 60 hours. The least favorable combination of variables was cryopreservation and a precryopreservation storage time of 60 hours.

CONCLUSIONS

We conclude that 30- to 60-hour delays do not have a significant metabolic effect on cardiac leaflets. Thus it may be possible to safely extend the permissible ischemic periods after organ harvest.

Tracheal agenesis with multiple congenital anomalies: a case report

Tracheal agenesis (TA) is a rare congenital anomaly that is incompatible with prolonged life. It may occur alone or with other associated anomalies. A term infant presented with cyanosis, hypotonia, absence of crying and respiratory distress at birth. Intubation was difficult. Esophageal intubation was performed under laryngoscopy. As TA was suspected, a bronchoscopy was performed and the infant was found to have a normal epiglottis and vocal cords; however, there was no trachea. Cardiorespiratory deterioration developed and the patient died on the night of the second day at the postnatal age of 41 hours. Tracheal agenesis was confirmed at autopsy. Associated anomalies included bronchoesophageal fistula, double outlet of the right ventricle with ventricular septal defect, bicuspid pulmonary valve, single lobe of the right lung, imperforate anus and a rectourethral fistula. According to development theory, tracheal agenesis and VACTERL (vertebral defects, anal atresia, cardiovascular defects, tracheoesophageal fistula, radial dysplasia or renal defects and limb defects association may result from a mesodermal deficiency caused by abnormal blastogenesis.

DiGeorge syndrome with microdeletion of chromosome 22q11.2: report of one case

DiGeorge syndrome (DGS) is a congenital anomaly involving developmental defects of the third and fourth pharyngeal pouches. Thymic aplasia or hypoplasia, parathyroid aplasia or hypoplasia, cardiac malformations, and dysmorphic facies are characteristics features. We present a case which had thymic aplasia, hypocalcemia, facial dysmorphism (hypertelorism, low set ears, cleft of soft palate, fish-like mouth and micrognathia) and congenital heart disease (ventricular septal defect, perimembranous type). The T-cell immunologic functions as a percentage of T-cell and phytohemagglutinin stimulation test were within normal range matched with age. Molecular study showed microdeletion of chromosome 22q11.2 by genotype analysis, but chromosome study of high-resolution cytogenetic analysis by G-banding technique was normal. To our knowledge, about 90% of DiGeorge syndrome patients show chromosome abnormalities, most involving chromosome 22 (monosomy of 22q11.2). In the past, most cases were proven by high-resolution cytogenetic analysis or fluorescence in situ hybridization(FISH). We report a case of DGS in Taiwan with microdeletion of chromosome 22q11.2 detected by genotype analysis.

Percutaneous removal of a nonopaque silastic catheter from the pulmonary artery in two premature infants

A modified snare was made from a 0.016' guidewire and a 0.1-mm fishing string to remove a nonopaque Silastic catheter via a femoral vein approach in 2 premature infants at the 44th and 120th day of life, respectively. A foldover guidewire loop snare had failed in 1 infant before this technique was successfully applied.

Changes in plasma levels of lipids and lipoprotein composition in patients with Kawasaki disease

Studies on the response of plasma lipids and lipoproteins to Kawasaki disease are scarce so far. The purpose of this study was to investigate the changes in plasma levels of lipids and apolipoproteins as well as the composition of different lipoproteins in patients during the acute and convalescence phases of Kawasaki disease. The results showed that during the acute phase, the concentrations of plasma high density lipoprotein (HDL)-cholesterol, apolipoprotein A-I (apoA-I) and A-II (apoA-II) were significantly reduced. While the reduction of HDL-cholesterol was mainly related to the lowering of esterified and unesterified cholesterols in HDL2 during the acute stage of Kawasaki disease, most of which recovered during the subsequent convalescence phase. The plasma concentration of triglycerides was 46% higher in patients during the acute phase of Kawasaki disease than in the control subjects, which may be ascribed to the increase of triglycerides in very low density lipoprotein (VLDL), low density lipoprotein (LDL) and HDL2. The variables studied above did not appear to be independent parameters. The level of plasma apoA-I showed a stronger negative association with triglyceride concentration (r = -0.22) than apoA-II (r = -0.11) and HDL-cholesterol (r = -0.07). Furthermore, the levels of cholesterol, apoA-I and apoA-II in HDL2, but not in HDL3, were inversely correlated with the levels of triglyceride. We conclude that the temporary changes of lipid levels associated with Kawasaki disease results predominantly from alterations of lipoprotein composition.

XTT-colorimetric assay as a marker of viability in cryoprocessed cardiac valve

This study sought to evaluate the use of tetrazolium salt XTT reduction as an indicator of valvular viability in a cryoprocessed porcine cardiac homograft model. The XTT tetrazolium assays was based on the metabolic reduction of Sodium 3'-[1-(phenylamino-carbonyl)-3,4-Tetrazolium]-bis(4-methoxy-6-nitro) benzene sulfonic acid hydrate. The relationship between XTT reduction and: (1) leaflet tissue with various weight (n = 24); (2) morphometric evaluation (n = 30); (3) cadaveric ischemic intervals (n = 30); (4) freeze-thawing (n = 30) has been studied. The measurement of XTT reduction were significantly correlated with the weight of cardiac leaflets, in the range of 30 to 180mg (y=0.015x-0.063; r=0.99). Compared to morphometry of valvular damage, the reduction of mitochondrial enzymatic activity in cardiac leaflets was correlated with matrix cells without irreversible damage (r=0.89, P<0.005). The depletion of XTT reduction occurred dependent of ischemic time intervals. In general, freeze-thawing reduced more than 20% activity of mitochondrial dehydrogenase. We concluded that XTT tetrazolium assay is highly sensitive to determine valvular injury. The study demonstrated its potential for testing of cryopreserved cardiac valve.

Transcatheter embolization of coronary artery fistula: a case report

Coronary artery fistula is rare, but it is the most common congenital coronary artery anomaly with hemodynamic significance. It usually causes no symptoms in young patients but may be associated with symptoms and complications in older patients. Surgery has been the traditional treatment. In this report, a 7-year-old girl who had a coronary artery fistula from the left circumflex coronary artery to the right atrium was successfully treated by percutaneous transcatheter technique.

Site-directed mutagenesis of the aspartokinase gene lysC and its characterization in Brevibacterium flavum

Using overlap extension polymerase chain reaction (PCR), five transformants of Escherichia coli containing site-directed mutagenized lysC beta gene were generated and analysed. Exchange of C to A and C to T at nucleotide 1118 of the mutated lysC beta gene causes a substitution of serine301 in the wild-type enzyme for tyrosine301 and phenylalanine301 in the mutant enzymes, respectively. Enzyme assays showed that Brevibacterium flavum cells harbouring pSUMN18 with mutated lysC beta genes exhibited 16-20 fold lower specific activities of aspartokinase as compared to that of host containing wild-type lysC gene. The mutation introduced into lysC beta of B. flavum CCRC 18271 resulted in partial feedback-resistant aspartokinase activity.

Aortic stenosis in children: 19-year experience

BACKGROUND

In the Taiwanese literature, few articles describe the pertinent features of aortic stenosis (AS). This study explores the features of AS in Chinese children.

METHODS

3808 children with congenital heart diseases have undergone cardiac catheterization at our institution over the past 19 years. Among them, 51 (1.3%) cases were AS. The clinical, electrocardiographic, echocardiographic and catheterization findings, the methods of treatment and outcomes were reviewed.

RESULTS

Valvular AS occurred in 39 children (76.5%), subvalvular AS in 5 (9.8%), and supravalvular AS in 7(13.7%). Male was predominant (M/F ratio, 2.6) except in supravalvular type. Forty-three patients had associated cardiovascular defects. Aortic regurgitation (AR) was the most common one. Most patients (56.9%) were asymptomatic. Classic symptoms included exertional dyspnea (17.6%), syncope (9.8%), and chest pain (7.8%), etc. Left ventricular hypertrophy was noted in 31.2% of cases. The mean duration of follow-up was 3.9 +/- 3.4 years. Ten patients received open-heart surgery and 2 received balloon dilation. The pressure gradients across the stenotic area dropped from 95.3 +/- 29.3 to 51.4 +/- 35.8 and 53.1 +/- 12.3 mm Hg in early and late Doppler follow-up studies, respectively (p < 0.05). The average gradient increased from 36.9 +/- 25.3 to 40.8 +/- 32.6 mm Hg in nonsurgical patients. The result was insignificant. No mortality occurred following open-heart surgery. One child expired due to heart failure after the ligation of the patent ductus arteriosus and dilation of the stenotic aortic valve on the surgical table under general anesthesia. Autopsy revealed valvular rupture. In the nonsurgical group, no mortality occurred, but one patient was brought home by parents in critical condition and later died.

CONCLUSIONS

We found that some clinical features of AS in Chinese children were different from those in occidental populations. (1) The incidence of AS was relatively low. (2) Subvalvular AS was the least common type in contrast to supravalvular AS in western studies. (3) Male predominance was not present in the supravalvular type, which lacked sexual proclivity. (4) Williams syndrome was a more frequently associated anomaly. Turner syndrome was not present in our study. (5) Isolated AS was less frequent. (6) The unusual finding such as right ventricular hypertrophy on EKG was present due to associated cardiac anomalies. Open-heart surgery is effective and safe, but the efficacy of balloon dilation requires further investigation.

Fixation of various porcine arteries with an epoxy compound

The clinical results of biological vascular grafts have been unsatisfactory. The poor results of these vascular grafts may be attributed to the fixatives, aldehydes, used in fixing tissues. In an attempt to overcome this problem, a new fixative, epoxy compound, has recently been used to fix biological vascular grafts. The study was undertaken to investigate the crosslinking characteristics, fixation index and denaturation temperature, of various porcine arteries fixed with an epoxy compound. The porcine arteries investigated in the study were the common carotid artery, internal thoracic artery, abdominal aorta, and saphenous artery. In addition, the effects of sonication on the porcine arteries before fixation on their crosslinking characteristics were analyzed. The fresh and glutaraldehyde-fixed arteries were used as controls. It was noted that glycine, proline, and alanine were the most abundant amino acids found in the porcine internal thoracic artery. In the amino acid analysis, it was observed that the amino acids in the porcine arteries reacted with epoxy compound or glutaraldehyde were lysine, hydroxylysine, histidine, and arginine. Of these amino acids, lysine was the most reactive. In general, the fixed arteries were relatively stiffer than their fresh counterparts. The fixation indices and denaturation temperatures of various porcine arteries were comparable throughout the entire fixation process. The amounts of free amino groups of the sonicated arteries were significantly lower than those of their unsonicated counterparts (p < 0.05). It is speculated that the diminishing free amino groups of the sonicated arteries may be attributed to the removal of the destroyed cell debris and adherent proteins of the arteries after sonication. However, it was learned that sonication on the porcine arteries before fixation did not seem to affect their fixation indices and denaturation temperatures. The results obtained in this study may help one in selecting the raw materials for developing a small-diameter biological vascular graft

Detachment of balloon in an infant: a rare complication of balloon pulmonary valvuloplasty

A 3-month-old infant with severe tetralogy of Fallot underwent percutaneous balloon valvuloplasty. After the successful dilatation, the balloon could not be deflated completely and the partial deflated balloon was totally peeled off from the catheter at the junction of inferior vena cava and right common iliac vein when we attempted to move it out. The skin of the balloon was successfully retrieved with a snared guidewire without sequel.

Evaluation of an epoxy-fixed biological patch with ionically bound heparin as a pericardial substitute

In an attempt to develop an improved pericardial substitute, we undertook the development of an epoxy-fixed biological patch with ionically bound heparin. The study was to evaluate the cross-linking characteristics of this newly developed biological patch using its glutaraldehyde-fixed counterpart as a control. In addition, the feasibility of using this newly developed biological patch as a pericardial substitute was assessed in a canine model. In the study, it was observed that the epoxy-fixed biological patch appeared more similar to the native pericardium in colour and was more pliable than its glutaraldehyde-fixed counterpart. Also, both the epoxy- and glutaraldehyde-fixed biological patches had significant increases in fixation index and denaturation temperature as compared to the fresh one (p < 0.05). In the canine study, the epoxy-fixed biological patch with ionically bound heparin was found to have significantly less adhesion formation than those currently used clinically (p < 0.05).

A clinical observation of term infants with critical cardiovascular disorders

BACKGROUND

Cardiovascular disorders are known to be the major causes for infants requiring intensive care. The consequences of the treatment given to these infants suffering from congestive heart failure and/or cyanosis need to be evaluated.

METHODS

A total of 210 infants both at term suffering from critical cardiovascular problems were hospitalized in the pediatric and neonatal ICU between July 1990 and December 1993. The etiology, clinical data, emergency procedures and outcomes of infants with or without congestive heart failure or cyanosis were analyzed.

RESULTS

Congenital cardiac defects were the most common cause of critical cardiovascular disorders in infancy. These included ventricular septal defect in 42 (20%), Tetralogy of Fallot in 22 (10.5%), Dtransposition of the great arteries in 20 (9.5%) cases, etc. The most common symptoms and signs observed were congestive heart failure in 162 (77.1%) and cyanosis in 137 (65.2%) cases. In spite of aggressive medical and surgical treatments, the outcomes were still unsatisfactory. The mortality rate was found to be the same in infants with or without congestive heart failure, but was significantly higher in infants with cyanosis than in those without cyanosis, after operation (28.5% vs 5.5%, p < 0.05).

CONCLUSIONS

Infants suffering from critical cardiovascular disorders need urgent medical and surgical treatments in intensive care units. In spite of treatment, the outcomes are still unsatisfactory.

Palliative treatment for tetralogy of Fallot with percutaneous balloon dilatation of right ventricular outflow tract

Percutaneous balloon pulmonary dilatation of the right ventricular tract was performed on 16 children with tetralogy of Fallot for palliative purposes after routine cardiac catheterization. Immediate improvement in aortic saturation from 73.4 +/- 6.8 to 84.0 +/- 4.8% (mean +/- SD = 10.6 +/- 2.7%, p < 0.001) and clinical symptoms were achieved in all 16 cases. The pressures in the right ventricle, pulmonary artery, left ventricle and aorta showed no remarkable changes after percutaneous balloon dilatation. The diameters of the proximal end and at the first branching of the right and left pulmonary arteries, pulmonary arterial index and the diameter of the descending aorta at the diaphragm increased significantly after balloon dilatation (p value 0.0004-0.006). One child suffered from repeated cyanotic spells in spite of the immediate improvement of aortic saturation. She received a left side Blalock-Taussig shunt 2 months after the balloon dilatation. None of the children had a significant complication. Eight had follow-up cardiac catheterization one year later and demonstrated much improvement in the diameters of the proximal end and at the first branching of the right and left pulmonary arteries, pulmonary arterial index and the diameter of the descending aorta at the diaphragm (p value 0.005-0.04). All 8 patients had their cardiac lesions successfully corrected. Percutaneous balloon dilatation is an alternative palliative therapy for children with tetralogy of Fallot.

Persistent infection of cultured cells with mouse hepatitis virus (MHV) results from the epigenetic expression of the MHV receptor

The A59 strain of murine coronavirus mouse hepatitis virus (MHV) can cause persistent infection of 17C1-1 cells and other murine cell lines. Persistently infected cultures released large amounts of virus (10(7) to 10(8) PFU/ml) and were resistant to superinfection with MHV but not to infection with unrelated Semliki Forest and vesicular stomatitis viruses. The culture medium from persistently infected cultures did not contain a soluble inhibitor such as interferon that protected uninfected cells from infection by MHV or vesicular stomatitis virus. The persistent infection was cured if fewer than 100 cells were transferred during subculturing, and such cured cultures were susceptible to reinfection and the reestablishment of persistent infection. Cultures of 17C1-1 cells that had been newly cloned from single cells consisted of a mixture of MHV-resistant and -susceptible cells. 17C1-1/#97 cells, which were cured by subcloning after 97 passages of a persistently infected culture over a 1-year period, contained 5 to 10% of their population as susceptible cells, while 17C1-1/#402 cells, which were cured by subcloning after 402 passages over a 3-year period, had less than 1% susceptible cells. Susceptibility to infection correlated with the expression of MHV receptor glycoprotein (MHVR [Bgp1a]). Fluorescence-activated cell sorter analysis with antibody to MHVR showed that 17C1-1/#97 cells contained a small fraction of MHVR-expressing cells. These MHVR-expressing cells were selectively eliminated within 24 h after challenge with MHV-A59, and pretreatment of 17C1-1/#97 cells with monoclonal antibody CC1, which binds to the N-terminal domain of MHVR, blocked infection. We conclude that the subpopulation of MHVR-expressing cells were infected and killed in acutely or persistently infected cultures, while the subpopulation of MHVR-nonexpressing cells survived and proliferated. The subpopulation of MHVR-negative cells produced a small proportion of progeny cells that expressed MHVR and became infected, thereby maintaining the persistent infection as a steady-state carrier culture. Thus, in 17C1-1 cell cultures, the unstable or epigenetic expression of MHVR permitted the establishment of a persistent, chronic infection.

Percutaneous balloon valvuloplasty in severe pulmonary valvular stenosis

Percutaneous balloon pulmonary valvuloplasty (PBPV) was achieved successfully in 20 of 22 patients with severe pulmonary valvular stenosis, aged two days to ten years (median four years and two months). The diameters of the balloon for PBPV were 88-125% (mean +/- SD = 109.5 +/- 10.0%) of the pulmonary valve annulus. PBPV failed in 2 patients because of the inability of the cardiac catheters to cross the stenotic valve. A significant reduction of right ventricle-pulmonary artery (RV-PA) pressure gradient occurred in all 20 patients (mean +/- SD = 72.1 +/- 10.3%). The mean RV-PA pressure gradient was reduced from 93.2 +/- 33.1 to 26.3 +/- 15.6 mmHg (P < 0.0001) and the mean right ventricular peak systolic pressure fell from 117.2 +/- 32.4 to 51.6 +/- 17.3 mmHg (P < 0.0001). Five (25%) of 20 patients had an infundibular gradient before PBPV. Two (10%) developed a new infundibular stenosis immediately after PBPV. Four (20%) presented with cyanosis, which disappeared after the successful PBPV. Two patients (10%) who showed a residual RV-PA pressure gradient of more than 40 mmHg had a significant infundibular obstruction initially. Two patients underwent recatheterization fifteen months after PBPV owing to a significant residual RV-PA pressure gradient and had no reductions in right ventricular pressure and RV-PA pressure gradient, but resolution of infundibular obstruction was noted in both. Repeat PBPV was successfully performed on these 2 patients. No significant complications were noted in any patient.(ABSTRACT TRUNCATED AT 250 WORDS)

A quantitative analysis of the structure of right ventricle-pulmonary artery junction for balloon pulmonary valvuloplasty in children

Percutaneous balloon valvuloplasty (PBVP) was performed in 55 children, aged from four days to twelve years and nine months, with different severity of congenital pulmonary stenosis (PS). To evaluate its efficacy, a quantitative analysis of the structure of right ventricle-pulmonary artery junction was conducted. Significant reductions of peak systolic right ventricular pressure, ratio of peak right-to-left ventricular pressure, and pressure gradients between the right ventricle and pulmonary artery were obtained in 48 children who scored 3 or less (Group I) and 7 children who scored over 3 (Group II) (P < 0.05). After two to forty-six months (M +/- SD = 17.1 +/- 15.5 months) of follow-up study, the residual gradients between right ventricle and pulmonary artery over 36 mmHg were higher in children who scored over 3 than in those who scored 3 or less (71.4% vs 20.8%) (P < 0.01). Repeated percutaneous balloon valvuloplasty was successfully performed in 4 children, 2 each in Group I and Group II. Surgical open pulmonary valvotomy was needed in 1 in Group II because of the dysplastic pulmonary valve and the need for repair of atrial septal defect and in 2 in Group I because of the failure to complete repeated PBVP in the catheterization laboratory or the need for repair of associated atrial septal defect.

A quality study of a computerized medical birth registry

Processed by a computerized medical birth registry system, the birth records of 20,103 deliveries, from February 1992 to February 1993, were digitized with medium registry. From January 1, to February 28, 1993, the original records (n = 2,840 cases) of all 10 collaborative hospitals were requested for assessment of the data quality. Thirty-six items were scored, data of poor quality was found in 8 items; acceptable quality in 4 items; and good quality in 28 items. The feasibility of data transfer by floppy disc and per modem was evaluated. This registry system had shortened data processing time effectively and improved mutual feedback between data center and delivery units. Errors resulting from technical faults originating in preparation of the data for computerizing at hospital level could be effectively reduced. The validity of diagnosis remained as the major source of errors.

Characterization of a new gene that encodes a functional MHV receptor and progress in the identification of the virus-binding site(s)

Several splice variants of the murine biliary glycoprotein 1 (Bgp 1) gene in the carcinoembryonic antigen gene superfamily serve as cellular receptors for mouse hepatitis virus. RNAPCR and immunoblot analysis of the receptor in inbred mouse strains showed that the glycoproteins expressed in SJL/J mice are encoded by an allelic variant of the Bgp 1 gene, named Bgp 1b. We recently cloned and characterized a second gene, Bgp 2, that encodes a functional MHV receptor glycoprotein which is not recognized by anti-MHVR MAb-CC1. A third gene related to Bgp 1 was cloned and expressed and shown to encode a soluble protein called Cea-10 that differs significantly in its N-terminal domain from Bgp 1 and Bgp 2. Chimeric proteins constructed between the different murine Bgps and point mutations in the prototype MHV receptor, Bgp 1a or MHVR, were analyzed to further characterize the MAb-CC1-binding and virus-binding domains within the N terminal domain of the receptor. Thus, the murine host for MHV expresses multiple splice variants of mRNAs encoded by several different Bgp-related genes which differ in their ability to serve as MHV receptors. The differential expression of these genes in different murine tissues may help to explain the tissue tropism of MHV strains.

Data quality of a computerized medical birth registry

Processed by a computerized medical birth registry system, the birth records of 20,103 deliveries, from February 1992 to February 1993, were digitized with medium registry. From 1 January to 28 February 1993, the original records (n = 2840 cases) of all 10 collaborative hospitals were requested for assessment of data quality. Thirty-six items were scored, data of poor quality was found in eight; acceptable quality in four; and good quality in 28. The feasibility of data transfer by floppy disc and per modem was evaluated. This registry system had effectively shortened data processing time and improved mutual feedback between the data centre and the delivery units. Errors resulting from technical faults originating in the preparation of data for computerization at hospital level could be effectively reduced. The validity of diagnosis remained as the major source of errors.

Percutaneous balloon valvuloplasty for congenital critical pulmonary stenosis in neonates

BACKGROUND

Percutaneous balloon valvuloplasty (PBVP) was performed on 6 neonates with severe pulmonary stenosis to evaluate its efficacy.

METHODS

The 6 studied neonates were aged from 1 to 30 days and weighed 2.5 to 3.3 kg. Follow-up period ranged 6-21 months with a mean of 11.5 +/- 6.3 months.

RESULTS

Dramatic improvement after PBVP was obtained not only on the clinical manifestations but also on the hemodynamic data. After percutaneous balloon valvuloplasty, the aortic O2 saturation increased significantly from 71.3 +/- 14.8% to 83.2 +/- 9.3% (p = 0.001) in 5 neonates who had cyanosis before PBVP. The right to left ventricular peak systolic pressure ratio decreased significantly from 1.65 +/- 0.41 to 0.77 +/- 0.27 (p < 0.001). The peak systolic right ventricular pressure dropped significantly from 104.0 +/- 18.8 to 48.8 +/- 13.6 mmHg (p < 0.001). The peak systolic gradient between right ventricle and main pulmonary artery dropped significantly from 83.2 +/- 16.2 to 24.3 +/- 16.3 mmHg (p < 0.05).

CONCLUSIONS

The percutaneous balloon valvuloplasty is safe and effective in treating the neonates with congenital critical pulmonary stenosis.

Pituitary function before, during, and after chronic gonadotropin-releasing hormone agonist therapy

OBJECTIVE

To examine possible adverse effects on pituitary function of long-term administration of gonadotropin-releasing hormone agonist (GnRH-a).

DESIGN

Prospective analysis of blood sampling before, during, and after GnRH-a therapy.

SETTING

Tertiary institutional outpatient care.

PATIENTS

Twelve normally ovulatory women with a diagnosis of endometriosis.

INTERVENTIONS

Six-month suppression with GnRH-a.

MAIN OUTCOME MEASURES

Serum levels of follicle-stimulating hormone, luteinizing hormone, free thyroxin index, cortisol (F), growth hormone (GH), prolactin (PRL), and thyroid-stimulating hormone (TSH).

RESULTS

Basal and stimulated values of gonadotropins, PRL, F, TSH, and GH were normal and unchanged by 6 months of GnRH-a after resumption of menses.

CONCLUSIONS

Utilizing dynamic pituitary function tests, we were unable to demonstrate an adverse effect of long-term GnRH-a therapy on pituitary function.

Connatal periventricular pseudocysts in the neonate

Connatal periventricular pseudocysts are important sequelae of different noxious insults in the developing brain. Accurate diagnosis of those pathologic entities during early life has therefore become of direct concern to the clinician. Our experience with 12 infants of connatal periventricular pseudocysts provides the basis of this study. They belonged to different pathological entities: focal paraventricular pseudocysts (5 cases), subependymal pseudocyst (3 cases), connatal viral infection (3 cases), and chromosomal abnormality (1 case). When present at birth, they suggest an intrauterine pathology. It has only been with the advent of real-time cranial ultrasound that periventricular pseudocystic lesions can be detected in neonates following an abnormal pregnancy. Some obstetric complications during the second trimester can cause paraventricular or subependymal pseudocyst in the foetus. Neurotrophic viral infection and chromosomal abnormalities have also been implicated in the production of cystic lesions in this region. These lesions are not a terminal event in infants but may be a condition of major clinical importance for further neurological development.