Biomedical subjects

R A Conte

Publications and source records attributed to R A Conte.

At least 19 recordsLinked to original sources

PubMed2001

Application of factorial design to study of heavy metals biosorption by waste biomass from beverage distillery.

A full factorial design leading to 20 sets of sorption runs was conducted to study the influence of four variables (bleaching earth and biomass concentrations, pH, and sorption time) on the iron, nickel, and chromium removal from stainless steel effluent using waste biomass from a beverage industry. Similar factor effects and interactions were found for each metal involved in this biosorption study, and the main factors were pH (positive effect) and biomass concentration (negative effect). Response surface methodology was adopted and an empirical linear polynomial model constructed on the basis of the specific uptake (mg of metal/g of biomass as dryweight) for each metal species. Under optimized process conditions (pH 4.0, biomass concentration of 2.0 g/L, absence of Celite), uptake values of 155 mg of Fe/g, 38 mg of Cr/g, and 0.4 mg of Ni/g were achieved after 3 h. This corresponded to a reduction in heavy metals concentration of approx 94% for Cr, 57% for Fe, and 25% for Ni.

Adsorption↗

PubMed2000

Determination of cobalt in sewage sludge using ultrasonic slurry sampling graphite furnace atomic absorption spectrometry.

Cobalt in sludge of domestic and industrial origin, with high iron contents (> 17 g/kg), was determined by slurry sampling graphite furnace atomic absorption spectrometry (GF-AAS). Slurries prepared by ultrasonic stirring were adequately diluted to cover the variation in cobalt content in the sludge samples. The diluent was 5% HNO3. Standard atomisation conditions for cobalt determination were used and no matrix modifier was applied. Slurry sampling GF-AAS results in the sludge were verified by analysing totally digested samples by inductively coupled plasma atomic emission spectrometry (ICP-AES) and by GF-AAS. The procedure was validated by analysing the certified reference material BCR 146 R, a sewage sludge of industrial origin. Recoveries for cobalt in the spiked slurried sludge samples ranged from 92 to 96%, with a relative standard deviation of 10%. Recoveries in the certified sludge using slurry sampling GF-AAS technique were about 103% for a cobalt content of 7.39 mg/kg.

Cobalt↗

PubMed1999

Localization of human midisatellite and macrosatellite DNA sequences on chromosomes 1 and X in the great apes.

The mechanism of speciation has remained largely unresolved, and hominoid evolutionary history based on chromosome rearrangements has been continuously challenged. The recent availability of the human-derived chromosome 1-specific midisatellite (D1Z2) and chromosome X-specific macrosatellite (DXZ4) DNA sequence probes has prompted us to hybridize the aforementioned to the members of the hominoid clade (chimpanzee, gorilla, and orangutan), using the fluorescence in-situ hybridization technique. Inconsistencies in the hybridization pattern for the D1Z2 DNA probe in the great ape species suggests that changes in this sequence have apparently taken place during the evolutionary process. No hybridization signal was observed in the orangutan chromosome 1, suggesting that a homologous D1Z2 DNA sequence may not be present in its genome, or that the sequence may be altered, rendering itself undetectable by human-derived DNA probes. Homology in the hybridization patterns for the DXZ4 probe in all three ape species illustrates that the sequence is apparently conserved. Such hybridization data provide some level of phylogenetic information on the recent ancestry of higher primates.

Animals↗

PubMed1999

Localization of subtelomeric sequences of human chromosomes 1q, 11p, 13q, and 16q in the higher primates.

Relative phylogenetic divergence of the members of the Pongidae family has been based on genetic evidence. The recent isolation of subtelomeric probes specific for human (HSA) chromosomes 1q, 11p, 13q, and 16q has prompted us to cross-hybridize these to the chromosomes of the chimpanzee (Pan troglodytes, PTR), gorilla (Gorilla gorilla, GGO), and orangutan (Pongo pygmaeus, PPY) to search for their equivalent locations in the great apes. Hybridization signals to the 1q subtelomeric DNA sequence probe were observed at the termini of human (HSA) 1q, PTR 1q, GGO 1q, PPY 1q, while the fluorescent signals to the 11p subtelomeric DNA sequence probe were observed at the termini of HSA 11p, PTR 9p, GGO 9p, and PPY 8p. Fluorescent signals to the 13q subtelomeric DNA sequence probe were observed at the termini of HSA 13q, PTR 14q, GGO 14q, and PPY 14q, and positive signals to the 16p subtelomeric DNA sequence probe were observed at the termini of HSA 16q, PTR 18q, GGO 17q, and PPY 19q. These findings apparently suggest sequence homology of these DNA families in the ape chromosomes. Obviously, analogous subtelomeric sequences exist in apes' chromosomes that apparently have been conserved through the course of differentiation of the hominoid species.

Animals↗

PubMed1999

Chromosomal basis of adenocarcinoma of the prostate.

Prostate cancer is the most frequent malignancy and the second leading cause of cancer deaths among males in the Western world. The clinical course of the disease is highly complex, and genetic factors underlying tumorigenesis are poorly understood. The challenge that lies ahead is to identify the important gene(s) that causes adenocarcinoma of the prostate. Chromosomal findings by cytogenetic and molecular methods, including Southern blotting, microsatellite analysis, fluorescence in situ hybridization, and comparative genomic hybridization, revealed a high frequency of chromosomal aberrations of heterogeneous nature, including: -1, +1, -1q, +4, -6q, -7, +7, -8, -8p, -8q, +i(8q), -9, -9p, -10, +10, +11, -12, -13q, -16, -16q, +16, -17, +17, +17q, -18, +18, -18q, +19p, +20q, +X, -Xq, -Y, and +Y. Specific chromosomal regions of alterations were 1q24-25, 2cen-q31, 5cen-q23.3, 6q14-23.2, 7q22-q31, 8p12-21, 8p22, 8q24-qter, 10q22.1, 10q23-25, 11p11.2, 16q24, 17p13.1, 18q12.2, and Xq11-12. Recently, a predisposing gene for early onset has been localized on 1q42.2-43. The losses of heterozygosity at specific chromosomal loci from chromosomes 5q, 6q, 7q, 8p, 8q, 10q, 13q, 16q, 17p, 17q, and 18q are generally correlated with poor prognosis in advanced tumor stage. In addition, an abnormal function of known tumor suppressor genes from these regions have been observed in prostate cancer. Although, the amplification of the androgen receptor gene at Xq11-13 and HER-2/neu gene at 17q11.2-q12 are novel findings, no single gene has been implicated in harboring prostate cancer. Frequent inactivation of PTEN/MMAC1 tumor suppressor gene at 10q23, MXI-1 at 10q25, KAI-1 at 11p11.2, Rb at 13q14.2, and p53 at 17p13.1 and deregulation of c-myc oncogene at 8q24 have recently been the subject of intense scrutiny and debate.

Adenocarcinoma↗

PubMed1999

Probing the human genome in search for a new 3q syndrome.

We report a case of partial trisomy 3q syndrome which could not be clinically identified as a distinct entity. The major clinical findings include: psychomotor delay with behavioral problems, coarse facial features, frontal bossing, bushy eyebrows, prominent ears, a small upturned nose and a history of repaired inguinal hernia. There was an additional material on chromosome 4, which could easily be matched with bands 18q21.2-q22; 2p24-p25; 16p21-p23; 10p12-p14; 20q12-q13.2; 15q25-q26.2; 8p23-p24.2 and 6p22.3-p24 and a new syndrome could apparently be suggested based on GTG techniques alone. Nevertheless, by FISH technique, the extra segment was identified as a part of 3q26.3-qter. We provide an extensive review of trisomy 3q syndrome and present a caveat of the consequences of description of new syndromes based on routine banding techniques especially in situations where the origin of chromosomal abnormalities is de novo or parents are not available for cytogenetic evaluation.

Child↗

PubMed1998

Molecular phylogenetics of the hominoid Y chromosome.

The Human Y-chromosome plays a central role in sex determination, and is composed of DNA sequences homologous to the Y-chromosome, families of Y-specific repetitive DNA sequences, and single copy sequences. We investigated the chromosomal location of Y-specific DNA sequences, in the chimpanzee (Pan troglodytes), gorilla (Gorilla gorilla), and orangutan (Pongo pygmaeus) by the fluorescence in situ hybridization (FISH) technique. The Yq subtelomeric DNA sequences (DYS427) have been observed to be intact at the presumed loci. Also, the amelogenin gene (AMELY, Yp11.2) revealed sequence homology and positional conservation in the higher primates, except in gorilla where positional divergence was observed.

Amelogenin↗

PubMed1998

Evolutionary divergence of the oncogenes GLI, HST and INT2.

Almost a quarter of a century ago, the banding patterns of human and other higher primate chromosomes were compared, creating a barrage of speculation. Consequently, a number of approaches have been used to understand human descent. Chromosome modifications are believed to be important in the origin of species, and pericentric inversions account for the majority of evolutionary chromosomal alterations seen in Hominoidea. A comparative mapping fluorescence in situ hybridization technique, using locus-specific DNA probes as phylogenotic markers, was used to decipher the pericentric inversions of human chromosomes 11 and 12. Human-derived (Homo sapiens, HSA) DNA probes for GLI, HST and INT2 protooncogenes were used to identify their homologous locations in the chromosomes of chimpanzee (Pan troglodytes, PTR), gorilla (Gorilla gorilla, GGO) and orangutan (Pongo pygmaeus, PPY). The INT2 and HST loci mapping results confirm the earlier putative claim that a pericentric inversion took place in HSA chromosome 11 and its equivalent PTR and GGO chromosomes. In addition, these data provide additional information regarding the orangutan's position on the evolutionary tree of Pongidae and Hominidae. GLI mapping reveals that a pericentric inversion occurred in the HSA chromosome 12 equivalent in PTR and GGO, but was not seen in HSA or PPY. These pericentric inversions in PTR and GGO may have occurred at a period when both PTR and GGO had branched off from the Hominoidae trunk. The use of loci-specific probes to decipher pericentric inversions has proved to be a formidable approach in characterizing chromosome rearrangements and providing further evidence on human descent.

Animals↗

PubMed1998

Chromosomal mosaicisms during prenatal diagnosis.

Chromosomal mosaicism during prenatal diagnosis has been a major concern. Nondisjunctional events can lead to mosaicism in a number of ways, including failure of chromosomal pairing, failure to separate, anaphase lag and abnormal segregation. We provide a concise review on various types of mosaicism with their clinical significance.

Amniocentesis↗

PubMed1998

Comparative mapping of the cri du chat and DiGeorge syndrome regions in the great apes.

Structural variations between great ape and human chromosomes due to pericentric inversions and translocations have created at apparent controversy during the reconstruction of hominoid phylogeny. One such variation involves human chromosome 5, which is equivalent to chromosome 4 in chimpanzee and orangutan but equivalent to segments of chromosomes 4 and 19 in gorilla. Obviously, neither banding patterns nor centromeric indecies in these chromosomes match. The pathological condition of cri du chat syndrome is due to the cytogenetic deletion of band p15.2 of chromosome 5. Is this region involved during pericentric inversion of apes chromosome 4? We used a human cosmid probe for cri du chat syndrome as a phylogenetic marker in search of the aforementioned question. The genomic sequences for cri du chat syndrome region were conserved in chimpanzee (PTR4) and orangutan (PPY4) but displayed a positional divergence in gorilla on chromosome 19(GG019). In addition, we used a human cosmid DNA probe for DiGeorge syndrome which is located on chromosome 22 band q11.2 and was conserved within band 23q11.2 in apes. The loci specific human genomic probes may help to describe the inversions and translocations for other chromosomes.

Animals↗

PubMed1997

Physical mapping of human 7q and 14q subtelomeric DNA sequences in the great apes.

Phylogenetic divergence of the members of the Pongidae family has been based on genetic evidence. The terminal repeat array (T2AG3) has lately been considered as an additional basis to analyze genomes of highly related species. The recent isolation of subtelomeric DNA probes specific for human (HSA) chromosomes 7q and 14q has prompted us to cross-hybridize them to the chromosomes of the chimpanzee (PTR), gorilla (GGO) and orangutan (PPY) to search for its equivalent locations in the great ape species. Both probes hybridized to the equivalent telomeric sites of the long (q) arms of all three great ape species. Hybridization signals to the 7q subtelomeric DNA sequence probe were observed at the telomeres of HSA 7q, PTR 6q, GGO 6q and PPY 10q, while hybridization signals to the 14q subtelomeric DNA sequence probe were observed at the telomeres of HSA 14q, PTR 15q, GGO 18q and PPY 15q. No hybridization signals to the chromosome 7-specific alpha satellite DNA probe on the centromeric regions of the ape chromosomes were observed. Our observations demonstrate sequence homology of the subtelomeric repeat families D7S427 and D14S308 in the ape chromosomes. An analogous number of subtelomeric repeat units exists in these chromosomes and has been preserved through the course of differentiation of the hominoid species. Our investigation also suggests a difference in the number of alpha satellite DNA repeat units in the equivalent ape chromosomes, possibly derived from interchromosomal transfers and subsequent amplification of ancestral alpha satellite sequences.

Animals↗

PubMed1997

Paracentric inversion involving the long arm of chromosome 9 resulting in deletion of abl gene.

We report on a new chromosomal finding in a newborn male with hypertelorism, apparently low-set malformed ears with patent canal, micrognathia with narrow high-arched palate, bilateral webbing of neck with low posterior hairline, widely spaced nipples, and complex heart anomalies. Initially, what appeared to be a simple paracentric inversion of the long arm of chromosome 9, that is, 46,XY, inv(9)(q31q34) by routine GTG-banding technique was later determined to be a paracentric inversion with deletion of the band 9q34.1 by FISH technique using an abl unique sequence DNA probe. Thus the cytogenetic diagnosis was modified to 46,XY,der(9) inv(9)(q31q34.1)del(q34.1). Nevertheless, the presence of telomeric repeat sequences in the inverted chromosome 9 suggests that either healing has occurred by adding [TTAGGG]n sequences to the non-telomeric end (q31) by the enzyme telomerase or telomeric sequences were not affected during this inversion process. This abnormality is a rare occurrence and has never been reported before either because of a high rate of lethality or it has been undetected by routine cytogenetic techniques. The other abnormal cases with apparent paracentric inversions could also have a complex nature with congenital anomalies associated with loss of "few" DNA sequences as exemplified here.

Abnormalities, Multiple↗

PubMed1997

Unique genomic sequences in human chromosome 16p are conserved in the great apes.

In humans, acute myelomonocytic leukemia (AMML) with abnormal bone marrow eosinophilia is diagnosed by the presence of a pericentric inversion in chromosome 16, involving breakpoints p13;q23 [i.e., inv(16)(p13;q23)]. A pericentric inversion involves breaks that have occurred on the p and q arms and the segment in between is rotated 180 degrees and reattaches. The recent development of a "human micro-coatasome" painting probe for 16p contains unique DNA sequences that fluorescently label only the short arm of chromosome 16, which facilitates the identification of such inversions and represents an ideal tool for analyzing the "divergence/convergence" of the equivalent human chromosome 16 (PTR 18, GGO 17 and PPY 19) in the great apes, chimpanzee, gorilla and orangutan. When the probe is used on the type of pericentric inversion characteristic of AMML, signals are observed on the proximal portions (the regions closest to the centromere) of the long and short arms of chromosome 16. The probe hybridized to only the short arm of all three ape chromosomes and signals were not observed on the long arms, suggesting that a pericentric inversion similar to that seen in AMML has not occurred in any of these great apes.

Animals↗

PubMed1997

Brief communication: comparative mapping of the human estrogen receptor (ESR) and the Kallmann (KAL) regions to the chromosomes of the great apes.

Human and great ape chromosomes display significant concordance by molecular and cytogenetic techniques, which may reflect their common origin. Nevertheless, chromosomal banding techniques did not reflect the syntenic homology at the DNA level, which created controversy and debate. The recent availability of the unique sequence loci-specific human estrogen receptor (ESR) (bq25.1) region and Kallmann (KAL) (Xp22.3) DNA probes have prompted us to search the degree of DNA sequence synteny among chimpanzee, gorilla, and orangutan by the FISH technique. The conservation of the ESR and Kallmann regions at the corresponding equivalent loci of the great ape chromosomes (5q25 and Xp22, respectively) has provided insights into genome evolution and facilitated assignment of map locations for human unique DNA sequences. These findings are aimed toward developing an augmented framework to determine with greater certainty the pathway of human descent at the single gene level.

Animals↗

PubMed1997

Delineation of a ring chromosome 16 by the FISH-technique: a case report with review.

We report on a new case with ring chromosome 16. Initially, the cytogenetic findings with GTG-banding revealed a 46,XY,r(16)(::p13.3-->q24::)/46,XY karyotype. This is the first case of r(16) co-existing with a normal cell line with minimal clinical consequences. The ring appeared to be monocentric and stable. A ring chromosome can result in a loss of varied segments of one or both chromosome arms or may involve telomere-telomere fusion without loss of genetic material. Thus it was imperative to use the latest molecular cytogenetic techniques for evaluation of this ring chromosome. It is believed that the ring chromosome retained specific telomeric sequences unique to 16q and that there was no loss of genetic material during the ring formation. Apparently, either a 16p telomere-16q telomere fusion or a fusion between the 16q telomere and a distal segment of the 16p13 band may explain the mechanism of ring formation. In either case, loss of genetic material is assumed to be negligible. A more descriptive karyotype of the proband was determined to be: 46,XY,r(16)(::pter or ::p13.3-->qter::)/46,XY. The fluorescent in-situ hybridization technique using various DNA probes provided this finer characterization.

Child, Preschool↗

PubMed1997

Variant euchromatic band within 16q12.1.

The enlarged short arm of chromosome 16 resulting in an additional euchromatic band has been regarded as a variant. We present an unreported case with an unusual variant of chromosome 16, where the mother and daughter both have an additional band (q12.1) in the long arm. Its origin is chromosome 16, as revealed by FISH-technique, and its familial nature suggests that it has no clinical significance.

Adult↗

PubMed1997

Characterisation of a satellited non-fluorescent Y chromosome (Y[nfqs]) by FISH.

A fetus was prenatally diagnosed as having a Y(nfqs) chromosome which was inherited from the father. With the QFQ technique, the Yqh was observed to be nonfluorescent and contained cytological satellites which were attached to the terminal long arm. The satellites were positively stained by the Ag-NOR technique suggesting that the NORs were active. A battery of DNA probes was used to characterise the Y(nfqs). Hybridisation experiments using a chromosome 15 specific classical satellite DNA probe (D15Z1) and a Yq telomere DNA probe showed that the additional satellited material on Yq originated from 15p, and that the Yq terminal region had been lost. This is the first reported case in which the origin of cytological satellites on Yq has been determined by FISH, but this does not imply that all satellited Y chromosomes are derived from 15p. However, the clinical significance of this Y(nfqs) chromosome remains obscure.

Adult↗

PubMed1997

Characterization of an isodicentric Y-chromosome for the long arm in a newborn with mixed gonadal dysgenesis.

A newborn infant was referred for evaluation because of ambiguous genitalia. Examination of the genitalia revealed a hypospadiac phallus measuring 1.5 cm in length with chordee. Subtle phenotypic features consistent with Turner syndrome were present including hypertelorism, anti-mongoloid slant to the eyes, mild widening of the neck, but no definitive webbing, shield like chest and positive cubitus valgus. A pelvic and renal sonogram confirmed the presence of a uterus and normal-appearing kidneys. There was incomplete fusion of the scrotum. No gonads were palpable within the scrotal sac. The patient was assigned a female gender on the basis of the presence of a uterus, the phenotypic appearance of the genitalia and the malignant potential of the gonads. The cytogenetic findings with QFQ-banding revealed an abnormal karyotype, i.e., mos 46,X,idic(Y) (p11.2)[77]/45,X[29]/46,X,idic(Y) (p11?) [2]/ 47,XY,idic(Y)(p11.2)[2]/47,X,idic(Y)(p11.2), + idic(Y)(p11.2)[1]/46,XY[1]. The presence of an abnormal isodicentric Y-chromosome was evaluated by FISH-technique to ensure a finer characterization than routine methods. The genotype-phenotype correlation could not be established since mosaicisms of highly variable nature can exhibit an unpredictable outcome.

Female↗