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Biomedical subjects

J Nores

Publications and source records attributed to J Nores.

14 recordsLinked to original sources
PubMed1998

Effect of ISDN bandwidth on image quality for telemedicine transmission of obstetric ultrasonography.

OBJECTIVE: To evaluate objectively the effect of different bandwidths on the ability to interpret obstetric ultrasound scans transmitted live over a commercial telephone network. MATERIALS AND METHODS: An integrated services digital network (ISDN) was established from three satellite offices to our central prenatal diagnostic center. In the first half of the study, the network was based on four ISDN channels transmitting at a bandwidth of 256 kbits per second (kbps), while in the second half of the study, this was increased to six ISDN channels transmitting at 384 kbps. A physician trained in obstetric ultrasonography provided an interpretation of fetal anatomy using a live, real-time telemedicine link. A scoring system consisting of 33 anatomic items was used to evaluate image quality objectively. The number of transmissions complicated by motion artifact was also recorded. RESULTS: One hundred patients had a fetal anatomy survey performed using the 256 kbps system, and these interpretations were compared with those from another group of 100 patients who were examined using the 384 kbps system. Although the visibility of the 33 anatomic items was similar using the two systems, significantly more examinations at 256 kbps were complicated by motion artifact (12% vs. 3%; P = 0.02). CONCLUSIONS: Remote sonographic viewing of fetal anatomy was adequate using both 256 and 384 kbps systems, although motion artifact was significantly more likely to occur using the slower system. This problem may affect the ability of the lower-bandwidth system to allow optimal detection when fetal anomalies are present.

Artifacts↗
PubMed1997

Validation of first-trimester telemedicine as an obstetric imaging technology: a feasibility study.

OBJECTIVE: To establish whether first-trimester obstetric ultrasonography interpreted by a live video telemedicine link is comparable to an established videotape review network in a low-risk patient population. METHODS: An integrated services digital network was established from three satellite offices to our central prenatal diagnostic center. All patients had a sonographic evaluation of the uterus, adnexa, and gestational sac recorded onto videotape by a trained sonographer. A live, interactive video telemedicine link was established, and a perinatologist directed the sonographer through the scan. Subsequently, a different perinatologist, blinded to the telemedicine interpretation, reviewed the original videotaped examination. The reports generated from both modalities then were compared by means of a score of 12 sonographic characteristics. RESULTS: The first 100 patients were included. The mean gestational age (+/-standard deviation) was 8.9 +/- 2.3 weeks (range 5.7-14.4), and the mean duration for telemedicine scans was 7.8 +/- 2.9 minutes (range 3.8-20.1). Telemedicine and videotape review scores were the same in 95 cases, and the final diagnosis was identical in 98 cases. This study had 80% power to detect a 10% difference in diagnosis at a significance level of .05. The ability to detect abnormalities was equivalent using both systems. CONCLUSION: The interpretation of first-trimester obstetric ultrasonography using live video telemedicine is equivalent to a system of videotape review. Obstetric telemedicine may prove to be a useful tool for providing sonographic imaging for low-risk obstetric patients.

Feasibility Studies↗
PubMed1997

Gender differences in twin-twin transfusion syndrome.

OBJECTIVE: To determine whether there is a gender discrepancy in severe twin-twin transfusion syndrome. METHODS: All cases of twin-twin transfusion syndrome evaluated between 1989 and 1996 were reviewed retrospectively. The following sonographic criteria were used: a single placenta, a thin membrane, the same gender, a combination of polyhydramnios-oligohydramnios, a stuck twin, and an estimated weight discordance exceeding 20%. At least five of six sonographic criteria were required for inclusion in the study. Only severe cases, which were defined as early onset (before 30 weeks' gestation), a combination of polyhydramnios and oligohydramnios, a stuck twin, fetal hydrops, fetal death, or the requirement of medical or invasive treatment, were included. Chorionicity was confirmed by placental examination when available. RESULTS: Thirty-seven twin pregnancies met the above criteria, of which 33 (89%) twin pairs were female. The median gestational age at presentation was 19 weeks (range, 15-29; standard deviation, 5.6). A single placenta, thin membrane, same gender, and polyhydramnios-oligohydramnios were present in every case. A stuck twin was noted in 34 of 37 cases (92%), and a growth discordance exceeding 20% was present in 26 of 36 (72%). Placental pathology, which was available in 31 (84%) cases, confirmed a monochorionic placentation in 29. Twenty-five (68%) cases had reduction amniocentesis, two were treated with indomethacin, one underwent a cord ligation, and in four cases, fetal death occurred before treatment was instituted. CONCLUSION: There is a significant female preponderance in pregnancies complicated by severe twin-twin transfusion syndrome. The reasons for this are nuclear, but they may be related to either placental or fetal gender-specific differences affecting a subset of monochorionic twin pregnancies.

Female↗
PubMed1997

Technical dependability of obstetric ultrasound transmission via ISDN.

OBJECTIVE: To evaluate the dependability of a live telemedicine link for the transmission of obstetric ultrasonograms using a commercial telephone network. MATERIALS AND METHODS: We established an integrated services digital network (ISDN), consisting of three dedicated telephone lines from three satellite offices, to our central prenatal diagnostic center. All patients had a sonographic evaluation recorded on videotape by a trained sonographer. A live interactive video telemedicine link was then established, and a perinatologist directed the sonographer through the scan. A report was issued on the basis of the telemedicine examination. The number of calls required to obtain satisfactory real-time images was recorded, as were the reasons for suboptimal transmissions. The first 150 transmissions were excluded from this study. The results in the subsequent 100 patients who agreed to participate were analyzed. RESULTS: We were able to provide obstetric interpretations in all 100 patients scheduled to be examined using the telemedicine link. A single connection was required in 85 cases, two calls in 5 cases, three calls in 8 cases, four calls in 1 case, and five calls in another case. A repeat call was required in 20 cases because of poor image transmission; other repeat calls were caused by failure to connect (5 cases), calls disconnected (2 cases), and no image transmission (2 cases). CONCLUSIONS: The provision of telemedicine services for obstetric ultrasonography in the community is feasible, but the need for repeat connections because of technical failures needs to be incorporated into cost and time analyses in order to provide a measure of the system's efficiency.

Female↗
PubMed1993

Microbial invasion of the amniotic cavity during term labor. Prevalence and clinical significance.

The purpose of this study was to determine the prevalence and clinical significance of microbial invasion of the amniotic cavity during spontaneous parturition at term. Amniotic fluid was retrieved by transabdominal amniocentesis from 90 women in spontaneous term labor with intact membranes. Fluid was cultured for aerobic and anaerobic bacteria, including Mycoplasma. The prevalence of positive amniotic fluid cultures was 18.8% (17/90). The most common microbial isolates were Ureaplasma urealyticum, Streptococcus agalactiae, Lactobacillus species and Mycoplasma hominis. Clinical signs of chorioamnionitis were present in three patients, and only one of them had a positive amniotic fluid culture. Five patients (5.5%) had puerperal endometritis; three of them had an amniotic fluid culture positive for microorganisms. All neonates were free of clinical signs of infection. The data indicate that microbial invasion of the amniotic cavity occurs frequently during spontaneous labor at term, and it may be both the cause and the consequence of labor.

Adolescent↗
PubMed1992

Eradication of Ureaplasma urealyticum from the amniotic fluid with transplacental antibiotic treatment.

Ureaplasma urealyticum was isolated from the amniotic fluid of a patient with preterm premature rupture of membranes at 24 weeks. A second amniocentesis performed 48 hours later indicated an increase in the number of neutrophils in the amniotic fluid. Treatment with erythromycin, ampicillin, gentamicin, and clindamycin was instituted for a period of 6 days. Amniotic fluid analysis from a third amniocentesis performed 24 hours after discontinuation of antibiotic treatment revealed only a few white blood cells and was negative for microorganisms. The pregnancy continued for 22 days after admission, at which time spontaneous labor began. The neonate survived with no sequelae and had negative blood cultures. Antibiotic treatment was associated with eradication of Ureaplasma urealyticum from the amniotic cavity, pregnancy prolongation, and neonatal survival.

Adult↗
PubMed1992

Limb-body wall complex associated with cocaine abuse: further evidence of cocaine's teratogenicity.

Limb-body wall complex is a complicated fetal malformation with the essential features of body wall disruption and limb abnormalities. Data from studies in the rat model suggest that vascular disruption is an etiology for limb-body wall complex. Because of its vasospastic properties, cocaine can act as a teratogen by impairing uteroplacental fetal blood flow during critical periods of development. We describe the prenatal detection of two fetuses with limb-body wall complex, whose mothers smoked large amounts of cocaine during the first trimester of pregnancy. Ultrasonographic evaluation of the fetus should be offered routinely in pregnancies complicated by maternal cocaine abuse.

Abdominal Muscles↗
PubMed1991

Amniotic fluid white blood cell count: a rapid and simple test to diagnose microbial invasion of the amniotic cavity and predict preterm delivery.

The purpose of this study was to determine the value of amniotic fluid white blood cell count in the diagnosis of microbial invasion of the amniotic cavity. Amniotic fluid was retrieved by amniocentesis from 195 patients with preterm labor and intact membranes. Fluid was cultured for aerobic and anaerobic bacteria, as well as for mycoplasmas. The prevalence of a positive amniotic fluid culture was 12.8% (25/195). Patients with a positive amniotic fluid culture had a significantly higher median amniotic fluid white blood cell count than did patients with a negative amniotic fluid culture (median, 6 cells/mm3; range, 0 to 11,000 cells/mm3 vs median, 320 cells/mm3; range, 1 to 4480 cells/mm3; p less than 0.0001). An amniotic fluid white blood cell count greater than or equal to 50 cells/mm3 had a sensitivity of 80% (20/25), a specificity of 87.64% (149/170), a positive predictive value of 48.78% (20/41), and a negative predictive value of 96.75% (149/154) in the detection of a positive amniotic fluid culture for microorganisms. Although the sensitivity of an amniotic fluid white blood cell count (greater than or equal to 50 cells/mm3) in the detection of microbial invasion of the amniotic cavity was greater than that of the Gram stain of amniotic fluid (80% [20/25] vs 48% [12/25]; p less than 0.05), the specificity was lower (87.64% [149/170] vs 98.8% [168/170]; p less than 0.05). However, 88% (15/17) of all patients with an amniotic fluid white blood cell count greater than or equal to 50 cells/mm3 and a negative amniotic fluid culture had a spontaneous preterm delivery. We conclude that the amniotic fluid white blood cell count is a sensitive, simple, and inexpensive test for the detection of microbial invasion of the amniotic cavity. An elevated amniotic fluid white blood cell count is a risk factor for preterm delivery.

Adult↗
PubMed1991

Meconium-stained amniotic fluid: a risk factor for microbial invasion of the amniotic cavity.

The purpose of this study was to determine whether meconium-stained amniotic fluid is a marker for microbial invasion of the amniotic cavity. Amniocentesis was performed on 707 patients presenting with preterm labor and intact membranes. Meconium-stained amniotic fluid was present in 4.2% (30/707) of patients with preterm labor. The prevalence of positive amniotic fluid cultures was significantly higher in women with meconium-stained amniotic fluid than in women with clear fluid (33% [10/30] vs 11% [75/677]; p = 0.001; odds ratio = 4.01; 95% confidence interval = 1.6 to 9.4). Patients with meconium-stained amniotic fluid were also more likely to have failed tocolysis and delivered a preterm neonate more frequently than patients with clear fluid (83% [25/30] vs 38% (258/677); p = 0.0001; odds ratio = 8.1; 95% confidence interval = 2.9 to 24.4). We conclude that meconium-stained amniotic fluid is a risk factor for microbial invasion of the amniotic cavity and preterm delivery in women with preterm labor and intact membranes.

Amniotic Fluid↗
PubMed1990

Infection and labor. VI. Prevalence, microbiology, and clinical significance of intraamniotic infection in twin gestations with preterm labor.

The purpose of this study was to establish the prevalence, microbiology, and outcome of microbial invasion of the amniotic cavity in twin gestation presenting with preterm labor and intact membranes. Amniocenteses were performed on both sacs of 46 women with twin gestations, preterm labor, and intact membranes. Indigo carmine was injected to ensure sampling of both amniotic sacs. Amniotic fluid was cultured for aerobic and anaerobic bacteria, Mycoplasma hominis, and Ureaplasma urealyticum. A positive amniotic fluid culture of at least one sac was noted in 10.8% (5/46) of patients admitted in preterm labor and in 11.9% (5/42) of women delivered of preterm neonates. Of the five patients with microbial invasion of the amniotic cavity, three had microorganisms isolated from both sacs. The presenting sac was involved in all cases, supporting an ascending route for microbial invasion of the amniotic cavity in twin gestation. Polymicrobial infection was found in three of the eight amniotic sacs with positive cultures. In two cases different organisms were isolated from each sac. All patients with positive amniotic fluid cultures were delivered of preterm infants within 48 hours of amniocentesis. Patients with positive amniotic fluid cultures presented with preterm labor at an earlier gestational age and with more advanced cervical dilatation than did women with negative amniotic fluid cultures. Clinical evidence of chorioamnionitis subsequently developed in two of five women with positive amniotic fluid cultures. The interval between amniocentesis and delivery was shorter in women with positive amniotic fluid cultures than in women with negative amniotic fluid cultures (median: 3.5 vs 168 hours, p less than 0.0001). Infants born to women with microbial invasion of the amniotic cavity had a lower median birth weight and a higher incidence of respiratory distress syndrome than those born to women with negative amniotic fluid cultures (birth weight: 1085 vs 1975 gm, p = 0.024; respiratory distress syndrome: 37.5% vs 8.3%, p = 0.04).

Amniotic Fluid↗
PubMed1990

Preterm delivery: a risk factor for retained placenta.

The purpose of this study was to determine whether preterm delivery, with and without intraamniotic infection, is a risk factor for retained placenta. This complication occurred more frequently in women with preterm vaginal delivery than in women with term vaginal delivery (9.1% [21/231] vs 1.1% [6/561]; p less than 0.00001; odds ratio = 9.25). There was no significant difference in the prevalence of retained placenta between women with preterm labor and intact membranes and those with preterm premature rupture of membranes (8% [10/125] vs 10.4% [11/106]; p greater than or equal to 0.05). A positive amniotic fluid culture or clinical chorioamnionitis was not associated with a higher incidence of retained placenta. This study indicates that preterm delivery is associated with an increased risk of complications of the third stage of labor.

Adult↗
PubMed1990

Amniotic fluid glucose concentration: a rapid and simple method for the detection of intraamniotic infection in preterm labor.

The purpose of this study was to determine whether amniotic fluid glucose concentrations is of value in the rapid diagnosis of intraamniotic infection. Amniocenteses were performed in 168 patients with preterm labor and intact membranes. Amniotic fluid was cultured for aerobic and anaerobic bacteria, as well as Mycoplasma species. The prevalence of positive amniotic fluid cultures was 13.6% (23/168). Patients with positive amniotic fluid cultures for microorganisms had significantly lower median amniotic fluid glucose concentrations than patients with negative amniotic fluid cultures (median 11 mg/dl, range 2 to 30 mg/dl vs median 28 mg/dl, range 3 to 74, respectively; p less than 0.001). Amniotic fluid glucose concentrations below 14 mg/dl had a sensitivity of 86.9% (20/23), a specificity of 91.7% (133/145), a positive predictive value of 62.5% (20/32), and a negative predictive value of 97.8% (133/136) in the detection of a positive amniotic fluid culture. Amniotic fluid glucose determination is a rapid, sensitive, inexpensive, and simple test for the detection of intraamniotic infection in women with preterm labor and intact membranes.

Amniotic Fluid↗
PubMedDate not supplied

Antenatal therapy of Smith-Lemli-Opitz syndrome.

OBJECTIVES: Smith-Lemli-Opitz syndrome (SLOS) is a recessively inherited disorder caused by an inborn error of cholesterol metabolism that results in deficiency of cholesterol and accumulation of the cholesterol precursor, 7-dehydrocholesterol (DHC) and its epimer, 8-DHC. Affected patients present with congenital anomalies, growth restriction, and mental retardation. Postnatal treatment with cholesterol supplementation has been shown to improve plasma sterol levels and has resulted in improved growth and development in many patients. We hypothesized that prenatal supplementation of cholesterol could potentially arrest some of the adverse consequences of cholesterol deficiency at an earlier stage of development. METHODS: SLOS was diagnosed in the third trimester in a fetus initially identified by sonography with intrauterine growth restriction and ambiguous genitalia and confirmed by elevated levels of 7- and 8-DHC in amniotic fluid. Antenatal supplementation of cholesterol was provided by fetal intravenous and intraperitoneal transfusions of fresh frozen plasma (cholesterol level = 219 mg/dl). RESULTS: The in utero transfusions resulted in increased levels of fetal cholesterol, as measured in blood samples obtained by cordocentesis. In addition, fetal red cell mean corpuscular volume rose, which further indicated that the exogenous cholesterol was incorporated into the fetal erythrocytes. CONCLUSIONS: Antenatal treatment of SLOS by cholesterol supplementation is feasible and results in improvement in fetal plasma cholesterol levels and fetal red cell volume. SLOS may be added to the growing list of human genetic disorders for which prenatal diagnosis is available and therapeutic intervention may be possible.

Cholesterol↗