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J D Goldberg

Publications and source records attributed to J D Goldberg.

At least 19 recordsLinked to original sources
PubMed1992

Anomeric specificity of D-xylose isomerase.

Crystal structures of complexes of D-xylose isomerase with deoxysugars have been determined. Deoxynojirimycin is a structural analogue of alpha-pyranose and mimics the binding of these aldose substrates. The structure of this complex supports the hypothesis that an imidazole group catalyzes ring opening of the pyranose. The steric restrictions in the active site of the enzyme prevent a beta-pyranose from binding in the same way. For the reverse reaction with ketoses, the anomeric specificity is less certain. Dideoxyimino-D-glucitol is a structural analogue of the ketose alpha-D-furanose. The binding of the inhibitor dideoxyimino-D-glucitol to the crystals of the enzyme does not mimic the binding of the reactive alpha-D-fructofuranose. Superposition of the nonphysiological substrate alpha-D-fructofuranose onto the atomic positions of dideoxyimino-D-glucitol is not possible due to the steric restrictions of the active site. However, by utilizing the approximate 2-fold symmetry of the sugar, a stereochemically sensible model is produced which is consistent with other data. In addition to reaction with alpha-D-furanose, the enzyme probably reacts with open ring keto sugars which are present at significant concentrations. Other sugars which resemble furanoses either do not inhibit significantly or are not observed in the crystals bound in a single conformation.

Aldose-Ketose Isomerases↗
PubMed1992

Crystallization and preliminary diffraction studies of hydroxypyruvate reductase (D-glycerate dehydrogenase) from Hyphomicrobium methylovorum.

Two crystal forms of hydroxypyruvate reductase (D-glycerate dehydrogenase) from the methylotrophic bacterium Hyphomicrobium methylovorum have been grown from ammonium sulphate solutions. One crystal form is triclinic, with unit cell parameters a = 60.4 A, b = 60.5 A, c = 66.3 A, alpha = 102.3 degrees, beta = 113.7 degrees and gamma = 102.7 degrees, suggesting that a dimer (monomer M(r) 38,000) occupies the unit cell. This crystal form diffracts to beyond 2.4 A resolution and is suitable for crystallographic structure analysis.

Alcohol Oxidoreductases↗
PubMed1992

Outcome of antenatally diagnosed cystic adenomatoid malformations.

OBJECTIVE: Twenty-two cases of antenatally diagnosed congenital cystic adenomatoid malformations are reported. STUDY DESIGN: Case management is reviewed. RESULTS: Eighteen women continued pregnancy after diagnosis. In nine cases nonimmune hydrops fetalis did not develop and all infants survived. Nonimmune hydrops fetalis developed in the other nine; fetal intervention was performed in eight cases. In the single case of nonimmune hydrops fetalis without intervention, the neonate died. In four cases aspiration of macrocystic lesions was performed. In two cases cystoamniotic shunts were placed. Neither aspiration or shunting provided long-term benefit. In six cases fetal lobectomy was ultimately performed and four survived. Two fetuses did not undergo in utero surgery; one was delivered prematurely after cyst aspiration and lived, and the other previable fetus was delivered soon after shunting. CONCLUSIONS: Fetal survival is best related to development of nonimmune hydrops fetalis. Aspiration of cystic lesions and cystoamniotic shunts generally provide short-term benefit. Early experience with fetal surgery for congenital cystic adenomatoid malformations has been encouraging.

Cystic Adenomatoid Malformation of Lung, Congenita↗
PubMed1992

Structure and mechanism of D-xylose isomerase.

The action of xylose isomerase depends on the presence of two divalent cations. Crystal structure analyses of the free enzyme, and of the enzyme bound to a variety of substrates and inhibitors, have provided models for a number of distinct intermediates along the reaction pathway. These models, in turn, have suggested detailed mechanisms for the various chemical steps of the reaction: a ring opening catalysed by an activated histidine, a hydride-shift isomerization, and a ring closure which may be facilitated by a polarised water molecule.

Aldose-Ketose Isomerases↗
PubMed1992

Toward strategies for the analysis of periodontal disease clinical trials.

We consider design, analysis and regulatory issues relating to clinical trials in periodontal disease and identify complications commonly associated with such studies. Alternative statistical procedures that can be used for the analyses of data from periodontal research are reviewed and a case study of the analysis of a Phase II periodontal disease clinical trial is provided to illustrate the use of one of these procedures.

Analysis of Variance↗
PubMed1992

Correlation between omphalocele contents and karyotypic abnormalities: sonographic study in 37 cases.

To evaluate the observation that fetuses with omphaloceles containing only bowel have an especially high prevalence of karyotypic abnormalities, we retrospectively reviewed the sonograms and case records of 37 fetuses with omphaloceles detected sonographically between 1984 and 1990. Nine fetuses had concomitant morphologic abnormalities characteristic of the amniotic band syndrome. Of the remaining 28 fetuses, karyotypic correlation was available in 22, and the karyotype was abnormal in five of these (23%). The omphaloceles contained liver in 22 fetuses and only bowel in six fetuses. Among fetuses with exteriorized liver, karyotypes were abnormal in one (6%) of 16 tested. In contrast, four (67%) of the six fetuses whose omphaloceles contained only bowel had abnormal karyotypes; for each of these four, sonograms showed morphologic abnormalities in addition to the omphalocele. In the two fetuses with bowel-only omphaloceles and normal karyotypes, the omphalocele was the only abnormality seen on sonograms, and these children are well after surgical repair. When fetuses with the amniotic band syndrome were excluded, sonograms showed concomitant anomalies in 15 fetuses with liver-containing omphaloceles, and the karyotype was abnormal in only one of these 15. The results of this study support previous observations that karyotypic abnormalities are more common in association with omphaloceles that contain only bowel compared with those that contain only liver. If we combine our data with data from three other studies that address this issue, 87% of fetuses with omphaloceles containing only bowel had an abnormal karyotype, a significantly higher rate than in those fetuses whose omphaloceles contained liver also (9%).

Amniotic Band Syndrome↗
PubMed1992

Treatment of acardiac-acephalus twin gestations by hysterotomy and selective delivery.

The acardius syndrome is a rare complication of monozygotic twin pregnancies, occurring once in 35,000 births. The outcome is invariably fatal for the acardiac twin and for 50-75% of the normal twins. We present a surgical approach to the treatment of this problem involving hysterotomy and selective delivery of the acardiac twin, which we have used in five cases. In the first case, placental abruption shortly after the procedure led to fetal death. The next two cases resulted in cesarean delivery of the remaining healthy singleton at 35 weeks' gestation. The fourth and fifth cases were delivered at 27 and 28 weeks' gestation, respectively, the first because of preterm rupture of membranes 2 weeks after the procedure and the second because of partial placental abruption 8 weeks after surgery; both of these infants are now doing well. There were no residual maternal complications. We conclude that hysterotomy has direct applicability in the management of these high-risk pregnancies.

Abnormalities, Severe Teratoid↗
PubMed1991

Prenatal diagnosis in multiple gestation: 20 years' experience with amniocentesis.

Three hundred and thirty-nine cases of multiple gestation underwent prenatal diagnosis by amniocentesis. The spontaneous abortion rate (to 28 weeks) in this group was 3.57 per cent compared with our singleton abortion rate of 0.60 per cent. The perinatal mortality rate (PMR) and prematurity rate were not different from the singletons, and compared favourably with the PMR reported in the literature for multiple gestations which did not undergo any intervention during pregnancy. This increased abortion rate following amniocentesis may only represent the increased natural loss rate in multiple gestations, and not indicate any increased risk added by the procedure.

Amniocentesis↗
PubMed1991

Prognosis of fetuses with a cystic hygroma.

This paper reports our experience with 55 fetuses identified in utero to have a cystic hygroma. The outcome of fetuses with an isolated cystic hygroma, cystic hygroma with non-immune hydrops, and cystic hygroma with multiple anomalies was evaluated. Approximately two-thirds of karyotypes were aneuploid, and a strong association of septation and aneuploidy existed. Only five cases, four of which had isolated hygromas, came to term and resulted in live births. Two of these involved small non-septated lesions which resolved in utero.

Adolescent↗
PubMed1991

First-trimester maternal serum unconjugated oestriol and alpha-fetoprotein in fetal Down's syndrome.

Maternal sera (MS) taken from 1396 women prior to chorionic villus sampling at 9-12 menstrual weeks were assayed for unconjugated oestriol (uE3) and alpha-fetoprotein (AFP). Median levels increased by 41 and 26 per cent per week respectively in normal pregnancies. There were 32 pregnancies with a chromosome abnormality. The median MS uE3 and AFP were 0.73 and 0.75 multiples of the median (MoM) respectively in the ten cases of Down's syndrome (DS) but not decreased in the other abnormalities. These results suggest that both uE3 and AFP may be useful in identifying DS in the first trimester. Additional prospective studies are needed to confirm these findings.

Adult↗
PubMed1990

Antenatal intervention for congenital cystic adenomatoid malformation.

In 2 fetuses with congenital cystic adenomatoid malformation (CCAM) with hydrops, in-utero resection of the enlarged pulmonary lobe reduced mediastinal shift and allowed expansion of normal lung tissue in both cases. In case 1, the 27-week-gestation fetus died from severe hydrops after premature delivery. In case 2, fetal CCAM resection was completed at 23 weeks' gestation. At 30 weeks a girl was delivered with no evidence of pulmonary hypoplasia. Fetal surgery can now be entertained for otherwise fatal space-occupying intrathoracic lesions.

Adult↗
PubMed1990

Current assessment of fetal losses as a direct consequence of chorionic villus sampling.

Chorionic villus sampling has been developed as a method of first trimester prenatal diagnosis. In order to evaluate this new approach, accurate risk figures for the procedure must be obtained. This has been difficult for a number of reasons, including establishment of baseline fetal loss rates in the first trimester, procedural "learning curves," and reporting biases. This review will discuss these problems and use data from the chorionic villus sampling program at the University of California, San Francisco, to illustrate difficulties in data interpretation.

Abortion, Spontaneous↗
PubMed1990

Conjoined twins: prenatal diagnosis and assessment of associated malformations.

Prenatal diagnosis of conjoined twins is difficult and was rarely accomplished prior to the advent of sonography. Early prenatal diagnosis and assessment for shared vital organs are desirable for optimal obstetrical counseling and management. The authors retrospectively reviewed prenatal findings in 14 cases of conjoined twins. Thoracoomphalopagus was the most common type of conjoining, occurring in five cases (36%). Prenatal sonography showed shared hearts in nine (64%) cases, indicating severe conjoining and negligible chance for postnatal correction. Two sets of omphalopagus conjoined twins had separate hearts; however, severe congenital heart disease was present. Early prenatal diagnosis and assessment of the degree of conjoining provided couples with the option for pregnancy termination via vaginal delivery. In this series, nine patients elected pregnancy termination prior to 24 weeks and delivered vaginally. Transvaginal ultrasound significantly improved the delineation of conjunction in two patients, and computed tomography permitted the diagnosis to be confirmed in two patients.

Diagnostic Errors↗
PubMed1989

Fetal hydrops and death from sacrococcygeal teratoma: rationale for fetal surgery.

Most sacrococcygeal teratomas diagnosed before birth can be managed by planned delivery and postnatal surgery. However, large tumors early in gestation may result in placentomegaly, hydrops, and fetal death and a preeclampsia-like syndrome in the mother. This chain of events may result from high output cardiac failure in the fetus caused by arteriovenous shunting through the tumor. We recently encountered this situation in a fetus at 21 weeks' gestation and performed fetal surgery in an attempt to reverse the process. Excision of the teratoma resulted in reversal of hydrops, diminution of descending aortic flow on Doppler echocardiography, and decrease in placental thickness. Despite these changes, uterine irritability after hysterotomy resulted in labor and delivery of a nonviable premature infant. This case demonstrates that when fetal sacrococcygeal teratoma becomes very large early in gestation, high output cardiac failure can endanger both fetus and mother. In the future, use of Doppler echocardiography may allow appropriate selection of high-risk fetuses. Intervention to prevent arteriovenous shunting through the tumor may offer these fetuses an improved chance for survival.

Adult↗
PubMed1989

Fetal tissue sampling. The San Francisco experience with 190 pregnancies.

Prenatal diagnosis of genetic defects was done using fetal blood sampling in 167 at-risk pregnancies, by fetal skin biopsy in 15 pregnancies, and by fetal liver biopsy in 8 pregnancies. Fetal blood sampling was done by fetoscopy through January 1985 and by sonographically directed percutaneous umbilical blood sampling since then. In our series, cytogenetics has become the major indication for fetal blood sampling, increasing from 6% of the cases with fetoscopy to 48% with umbilical blood sampling. Fetoscopy provided pure fetal blood in 61% of cases while umbilical blood sampling provided pure fetal blood 97% of the time. The corrected risk of fetal demise after percutaneous umbilical fetal blood sampling was 2% and after fetoscopy was 4%.

Biopsy↗
PubMed1988

Selective termination of multiple gestations.

Twenty-two selective terminations in multiple gestations were performed by a number of different methods. In 17 dichorionic pregnancies there was a successful delivery in surviving singletons or twins. In five monochorionic pregnancies undergoing selective termination there was a successful delivery in only one and a pregnancy loss in the other four. Six of the 18 delivered pregnancies were complicated by premature labor and delivery. Among the several methods used for selective termination, intracardiac potassium chloride injection appears to be the procedure of choice in dichorionic pregnancies.

Abortion, Induced↗