Search PubMed⌕ Search

Biomedical subjects

C H Liu

Publications and source records attributed to C H Liu.

At least 109 records · Page 6Linked to original sources
PubMed1995

Misalignment effects in 3-D versions of Poggendorff displays.

Strong misalignment effects are found in three-dimensional (3-D) versions of Poggendorff displays viewed binocularly. The components of the standard 2-D Poggendorff figure--the parallels and the oblique segments--were presented in 3-D depth as a flat rectangular object with occluding edges and an oblique line situated behind the object. Three experiments investigated the misalignment effects under three different observation instructions: Subjects were told to look at the oblique (Experiment 1), at the rectangle (Experiment 2), or at the background (Experiment 3). Experiments 1 and 2 examined the effects on judgments of alignment of varying the distance in depth that separates the oblique from the rectangle. Experiment 3 examined the effects of varying the distance between the fixated background and the 3-D Poggendorff figure. Both standard and reversed misalignment effects were obtained. When the viewing condition produces crossed disparity for the oblique, perceived misalignment occurs in the usual Poggendorff direction, but it is reversed with uncrossed disparity. Moreover, the amount of misalignment is related to the amount of disparity, and it can be much stronger than is usual in the 2-D versions of the Poggendorff. The misalignment effects can be explained by binocular integration to produce a single cyclopean image.

Adolescent↗
PubMed1995

Priming reversal of profound atracurium blockade by edrophonium and neostigmine.

Accelerated reversal of moderate neuromuscular blockade has been reported to be effective by giving anticholinesterase in divided doses (priming reversal). To evaluate its effectiveness in profound blockade, forty ASA physical status I or II patients were studied. After receiving 0.5mg/kg of atracurium during N2O-O2-halothane anesthesia, they were reversed at 5% spontaneous recovery of first twitch height (T1) measured by train-of-four (TOF) stimulation. Edrophonium 1mg/kg was administered intravenously either in a single bolus dose (Group I, n = 10) or in an initial priming dose of 0.2mg/kg followed one minute later by 0.8mg/kg (Group II, n = 10). Neostigmine 0.05mg/kg was administered in a single bolus dose (Group III, n = 10) or in divided priming dose of 0.01 mg/kg followed one minute later by 0.04mg/kg (Group IV, n = 10). The recovery time from the first injection of the reversal agents until the TOF ratio reached 75% was significantly longer (p < 0.05) in Group III (681.5 +/- 77.5 sec) compared to Groups I, II, and IV (451.3 +/- 72.3 sec, 470.6 +/- 39.8 sec, and 448.1 +/- 42.5 sec, respectively; no statistical difference among these three groups). It is concluded that priming reversal by neostigmine, but not edrophonium, produced a significantly faster recovery of profound atracurium blockade. Using the priming method, neostigmine may reach a similar recovery time as edrophonium in profound blockade under equipotent doses.

Adult↗
PubMed1995

[The thermoregulatory threshold during surgery with propofol-nitrous oxide anaesthesia].

BACKGROUND: Thermoregulatory responses are thought to be drastically suppressed by general anesthesia. In previous studies, it was shown that halothane, isoflurane and fentanyl-N2O combination decrease the threshold of vasoconstriction in general anesthesia. Propofol is a recently introduced intravenous anesthetic. The thermoregulatory threshold of its administration during surgery has not been quantified. MATERIALS: Fourteen unpremedicated ASA class I patients were anesthetized with N2O (67%) and propofol (2 mg/kg in bolus followed by 6 mg/kg/h infusion) during elective surgery of free flap. Patients were randomly assigned either to receive additional warming (n = 5) or standard (n = 9) management. Significant vasoconstriction was prospectively defined as the temperature gradient between forearm surface and finger-tip surface is > or = 4 degrees C, and the thermoregulatory threshold was defined as the esophageal temperature (core temperature) at a point where the skin temperature gradient between two tested zones exceeds 4 degrees C. RESULTS: Vasoconstriction did not occur in patients who received additional warming and they remained in nearly normothermia. The average minimum core temperature was 36.3 +/- 0.4 degrees C. In patients who underwent standard management the core temperature ranged from 32.8 to 34.6 degrees C (33.6 +/- 0.7 degrees C), signifying significant vasoconstriction. CONCLUSIONS: General anesthesia with propofol/N2O during surgery drastically inhibits thermoregulatory vasoconstriction. This effect should also be noted during long-term use of propofol (e.g. ICU-sedation).

Adult↗
PubMed1994

Characterization of 57 kDa statin as a true marker for growth arrest in tissue by its disappearance from regenerating liver.

Statin, a 57 kDa nuclear protein, is lost from quiescent fibroblasts in culture when they are induced to enter the cell cycle by feeding with growth factors, or by removal of contact inhibition. In order to investigate changes in statin expression during the transition from a quiescent to a cycling state in situ, we performed 70% partial hepatectomy on rats and analyzed the regenerating liver by immunofluorescence microscopy with antistatin monoclonal antibodies (S44 mAb), and by immunoblotting of liver proteins in cytoplasmic and enriched nuclear/cytoskeletal fractions. Western blot analysis showed that rat hepatocytes in situ contain a nuclear 57 kDa form of statin, as seen in cultured fibroblasts; however additional S44-immunoreactive polypeptides with molecular weights of 53 and 110 kDa are also present in both cytoplasmic and nuclear/cytoskeletal fractions. Immunofluorescence microscopy indicates that the proportion of S44-positive hepatocyte nuclei drops to approximately 60% within 24 hours after hepatectomy, a time period when re-entry of hepatocytes into the cell cycle is first observed. On Western blots of hepatocyte nuclear/cytoskeletal proteins obtained 24 hours after hepatectomy, the 57 kDa form of statin is markedly reduced. These results suggest that, although in liver the S44 antibody recognizes three proteins (53 kDa, 57 kDa, and 110 kDa), the 57 kDa in intact liver, similar to cultured fibroblasts, is the only polypeptide recognized by the statin antibody that disappears when hepatocytes are induced to re-enter the cell cycle from a quiescent state.

Animals↗
PubMed1994

Avian embryonic brain reaggregate culture system. I. Characterization for organophosphorus compound toxicity studies.

An avian reaggregate culture system was characterized biochemically and morphologically for use in acute and chronic organophosphorus compound (OP) toxicity studies. Ten-day-old chick embryo brains were dissociated, reaggregated, and maintained in a chemically defined, serum- and antibiotic-free media. Acetylcholinesterase (ACHE), neuropathy target esterase (NTE), and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) were examined due to inhibition of these enzymes as a result of acute OP toxicity (ACHE) or delayed toxicity (NTE, CNP). The selected enzymes also indicate reaggregate neuronal (ACHE, possibly NTE), oligodendroglial (CNP), and astrocytic (glutamine synthetase (GS)) activities. Enzyme activities were compared to those in age-matched chick embryo and hatched chick brains. Reaggregate ACHE specific activity was similar to or higher than that of chick embryo or hatched chick. Reaggregate NTE specific activity was initially similar to that of 10-day-old chick embryo, and then increased but subsequently averaged 7.8 nmol/min/mg protein. In chick brain, NTE peaked at hatching and averaged 28 nmol/min/mg protein thereafter. Reaggregate CNP specific activity ranged from 103 to 426 nmol/min/mg protein, whereas activity gradually increased in chick embryo brain to an average of 140 nmol/min/mg protein posthatching. The mean GS activity ranged from 0.15 (Culture Day 4) to 1.09 nmol/min/mg protein (Culture Day 62). Mean protein values per flask ranged from 2.47 to 7.58 mg. Ultrastructurally, myelination was detected at Culture Day 7 and synapses at Day 6. The biochemical and ultrastructural features demonstrate that this reaggregate culture is a practical and sensitive in vitro system for studying both the acute and the long-term neurotoxicological effects of organophosphorus compounds.

Acetylcholinesterase↗
PubMed1994

Avian embryonic brain reaggregate culture system. II. NTE activity discriminates between effects of a single neuropathic or nonneuropathic organophosphorus compound exposure.

Biochemical responses after a single exposure to either a neuropathic or a nonneuropathic organophosphorus compound (OP) were compared using chick embryonic brain cell reaggregates. Ten-day-old chick embryo brains were dissociated and then reaggregated and maintained in a chemically defined, serum-free medium without antibiotics. Seven days later, these cultures were treated for 20 min with either neuropathic diisopropyl phosphorofluoridate (DFP, 10(-4) M) or nonneuropathic paraoxon (10(-6) M). Reaggregates were assayed for acetylcholinesterase (ACHE), neuropathy target esterase (NTE), and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) activities for up to 32 days after exposure. These enzymes were examined due to inhibition of activity as a result of acute OP toxicity (ACHE) or delayed toxicity (NTE, CNP). DFP inhibited > 95% of NTE activity immediately after exposure. By Postexposure Day 2, NTE specific activity was 22% of untreated activity but was similar to the untreated group levels by Postexposure Day 7. Paraoxon exposure did not affect NTE activity. Both paraoxon and DFP inhibited > 99% of ACHE activity immediately after exposure. By Postexposure Day 2, ACHE specific activity in paraoxon-exposed cultures had recovered while ACHE remained 56% inhibited in DFP-exposed cultures. Both paraoxon- and DFP-exposed cultures recovered ACHE activity immediately following OP exposure if treated postexposure with an oxime reactivator, 2-pralidoxime. CNP specific activity was not affected by either paraoxon or DFP. These results demonstrated distinct differences in reaggregate NTE and ACHE activities after single exposure to neuropathic DFP and nonneuropathic paraoxon similar to those in avian in vivo assays.

Acetylcholinesterase↗
PubMed1994

Membrane proteases as potential diagnostic and therapeutic targets for breast malignancy.

Metastasizing cancer cells can invade the extracellular matrix using plasma membrane protrusions, termed invadopodia, that contact and dissolve the matrix. Various membrane associated proteases localized on the invadopodial membranes are responsible for the extracellular matrix degradation. Work from our laboratory shows that secreted proteases including Gelatinase A, and high molecular weight integral membrane proteases are associated with cell surface invadopodia. Three cell types, including chicken embryonic cells transformed by Rous sarcoma virus, human malignant melanoma cell line LOX, and human breast carcinoma cell line MDA-MB-231, retain the invasive phenotype in vitro, express invadopodia, degrade and enter into a fibronectin-rich collagenous matrix. We suggest that invadopodium-associated proteases are ideal targets for the diagnosis and treatment of cancer as their presence in association with primary tumors may signal increased metastatic potential. An approach toward the development of new prognostic markers for breast malignancy involved production of monoclonal antibodies directed against membrane proteases in a mixture of glycoproteins. Double immunofluorescent technique using a known invadopodium marker is designed to select specific monoclonal antibodies colocalizing at the invasion front, on invadopodia of cancer cells. Membrane protease accessibility at the cell surface can therefore be exploited for therapeutic advances by the development of specific antibodies and inhibitors that block their activities, and by the use of monoclonal antibodies to target cytotoxic molecules to micrometastases. Also, this same accessibility may potentially be used to detect surface proteases on micrometastases or to detect components shed by micrometastases in serum.

Antigens, Neoplasm↗
PubMed1994

Neuropathology of organophosphate-induced delayed neuropathy (OPIDN) in young chicks.

To examine the phenomenon of apparent age resistance of young chicks to organophosphate-induced delayed neuropathy (OPIDN), groups of either 2- or 10-week-old chicks were exposed subcutaneously daily for 4 days to the neuropathic organophosphate (OP), di-isopropylfluorophosphate (DFP, 1 mg/kg), the non-neuropathic OP, paraoxon (PO, 0.25 mg/kg) or atropine (20 mg/kg). Subsequently, all birds were examined at post-exposure intervals (calculated from the last day of exposure) for up to 56 days for neurological deficits and morphological lesions in the central and peripheral nervous systems (CNS, PNS). Clinically, none of the birds in the 2-week-old groups, or in the 10-week-old PO or atropine exposed groups had neurological deficits. However, all birds in the 10-week-old DFP exposed group developed ataxia by 7 days post-exposure (DPE) and then progressive paralysis. Therefore, all birds in the 10-week-old groups were killed at 14 DPE. Pathologically, the 2-week-old DFP exposed chicks had increasingly severe lesions of Wallerian-like degeneration predominantly in the spinal cord from 7 DPE and subsequently. In the 10-week-old DFP exposed chicks, the degenerative lesions of OPIDN were first detected in the CNS at 3 DPE and then with equally increasing severity in the CNS and PNS up to 14 DPE. A higher incidence of neuronal necrosis and chromatolysis in ventral motor horn neurons of spinal cord grey matter and in dorsal root ganglia occurred in both the DFP exposed age groups compared with those lesions in other groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1994

Evaluation of computerized edge tracking for quantifying intima-media thickness of the common carotid artery from B-mode ultrasound images.

A new method to measure carotid intima-media thickness (IMT) from B-mode ultrasound images was developed that utilizes automatic tracking of the lumen-intima and media-adventitia echoes. Phantom studies and human replicate studies under typical clinical protocols for common carotid IMT measurement were carried out to assist in evaluation of the method. A lucite step wedge phantom was used to show that incorporation of sub-pixel interpolation to locate echo boundaries allowed detection of changes in the echo separation that were 5-10 times smaller than the axial resolution of the ultrasound transducer. For average IMT measured in the distal common carotid artery (CCA) wall in 24 subjects scanned twice within 60 days, mean absolute difference was 0.036 mm with a standard deviation of 0.045 mm. Replicate scans obtained 1 week apart of eight subjects by three sonographers showed the intersonographer variability was 5.4%. In another study of 12 subjects scanned every 4 months for 48 months, the root mean square deviation of the IMT measurements from a linear regression line was 0.030 mm. These data indicate that the method is equally precise over short intervals (60 days) and over long intervals (48 months). The new automated computerized edge tracking method presented in this paper represents an advance for image analysis of B-mode ultrasound images of common carotid IMT with measurement variability substantially reduced (2 to 4 times) compared with currently available manual methods.

Adult↗
PubMed1994

Characterization of integrins in cultured human renal cortical tubule epithelial cells.

We have characterized the integrins present on cultured tubule epithelial cells from human renal cortexes, enriched for proximal cells, using fluorescence microscopy, immunoprecipitation, and cell adhesion assays. By immunofluorescence, the alpha 3-integrin subunit stained most intensely and was present on all cells predominantly at cell-cell contacts. The alpha 6-subunit was present on all cells in a pattern consistent with extracellular matrix contacts. The alpha 5-subunit was present on most cells in a cell-matrix contact pattern; alpha V-subunit was weakly positive and occasionally seen in cell-matrix contacts. The alpha 2-subunit was present on clusters of distal tubule cells, predominantly at cell-cell contacts. Immunoprecipitation revealed the predominant integrin to be alpha 3 beta 1 with some alpha 2 beta 1, presumably contributed by distal cells. The alpha 5 beta 1-, alpha 6 beta 1-, alpha 6 beta 4-, and alpha V beta 3-integrins, as well as trace amounts of alpha 1 beta 1-integrins, were also present. The alpha 4 beta 1-integrin was not detected. Initial attachment to fibronectin was mediated by alpha V beta 3- and alpha 5 beta 1-integrins; initial attachment to laminin was mediated by the alpha 6 beta 1- and alpha 3 beta 1- integrins and, in some preparations, by an unidentified integrin; and initial attachment to collagen type IV was mediated by alpha V beta 3-integrin and an unidentified beta 1-integrin. After extensively immunodepleting membrane extracts with anti-alpha 1, -alpha 2, -alpha 3, -alpha 4, -alpha 5, -alpha 6, and -alpha V antibodies, an anti-beta 1 antibody still precipitated an integrin. Its electrophoretic mobility differs from the laminin-binding alpha 7 beta 1-integrin. Thus we have identified many of the integrins on cortical tubule cells and their role in mediating initial attachment to extracellular matrix. However, the cell adhesion assays and immunoprecipitations suggest the presence of an unidentified beta 1-integrin that may mediate renal tubule cell attachment to laminin and collagen.

Cell Adhesion↗
PubMed1994

Molecular cytogenetic studies of children with marker chromosomes.

The molecular cytogenetic characterization and clinical description of 15 children with marker chromosomes of unknown nature are presented. By combining both conventional cytogenetic methods (G-, C-, Ag-NOR- and Distamycin-A/DAPI bandings) and molecular techniques (fluorescence in situ hybridization), the chromosomal origin of these markers was successfully determined. The marker chromosomes were first characterized by cytogenetic techniques and later identified by fluorescence in situ hybridization, using a procedure involving stepwise hybridization of chromosome-specific DNA probes (alpha and classical satellites) at various conditions of stringency. There were four cases with bisatellited markers (of chromosome 15 origin), one with acrocentric satellited marker (of chromosome 13 or 21 origin), and two carrying markers that appeared to be autosomal rings (of chromosomes 13 and 18, respectively). The other eight cases belonged to mosaic (n = 5) or nonsupernumerary (n = 3) sex-chromosomal anomalies. Six were of Y and two of X chromosomal origin. Because no familial cases were found, these markers probably developed de novo. In cases of supernumerary marker with satellites, the origin was from acrocentric groups and had common features such as mild to moderate psychomotor retardation and mild facial dysmorphism. In the cases of autosomal ring, multiple anomalies and moderate to severe retardation occurred. For the category of sex-chromosomal origin, stigmata of Turner's syndrome and/or ambiguous genitalia were noted. Mentality was normal.

Child↗
PubMed1993

Expression of an EF-1 alpha-like rat cDNA, S1, in E. coli and production of a rabbit polyclonal antiserum to the recombinant protein.

A previously identified rat cDNA (S1) that shares 78% nucleotide homology and a predicted 92% amino acid homology with human EF-1 alpha was constructed into PGEX-2T and inducibly expressed in E. coli as a fusion protein. The purified recombinant S1 protein (rpS1) was used to raise rabbit antiserum which recognized rpS1 but not EF-1 alpha on immunoblots. A polyclonal antiserum to EF-1 alpha failed to react with the rpS1. Our results indicate that rpS1 protein can be used to produce antibodies which distinguish pS1 from EF-1 alpha despite their extensive amino acid sequence homology.

Amino Acid Sequence↗
PubMed1993

The effect of organophosphates on a chicken brain or sea urchin egg kinesin-driven microtubule motility assay.

The effect of neuropathic and non-neuropathic organophosphates (OPs) and acrylamide on an in vitro kinesin-driven microtubule (MT) motility assay was compared. The goal of the study was to determine whether this in vitro assay could confirm that a mechanism of action of neuropathic OPs was to impair kinesin activity and, therefore, possibly fast axonal anterograde transport (FAAT) in vivo. For our study, kinesin from chicken brain (CK) and sea urchin egg (SUK) was initially purified. Western immunoblotting confirmed the close antigenic homology between CK and SUK, using a mouse monoclonal sea urchin kinesin heavy chain-specific antibody (SUK 4). In the presence of microtubules (MTs) and MgATP, both CK- and SUK-driven MT movement was measured using a video-enhanced differential interference contrast microscope system with computer-assisted analysis. Using this assay system, we then tested separately the effect of two neuropathic OPs (diisopropylfluorophosphate (DFP) and phenyl saligenin phosphate (PSP)) and a non-neuropathic OP (paraoxon (PO)) each at a concentration of 10(-2) M at 27 degrees C. Additionally, we tested acrylamide (10(-2) M), since it is one of the best-characterized neurotoxins impairing FAAT in vivo. Our results demonstrated that none of these compounds significantly affected kinesin-driven MT motility in vitro compared to the standard controls. Further, this assay system was thus not able to discriminate between the neuropathic and non-neuropathic effect of these OPs.

Acrylamide↗
PubMed1993

Beneficial effects of colestipol-niacin therapy on the common carotid artery. Two- and four-year reduction of intima-media thickness measured by ultrasound.

BACKGROUND: Controlled clinical trials have reported treatment effects evaluated with serial imaging in coronary and femoral but not cervical arteries. The Cholesterol Lowering Atherosclerosis Study, a coronary, cervical, and femoral angiographic trial of colestipol plus niacin, included a pilot study of standardized carotid ultrasound imaging. METHODS AND RESULTS: Seventy-eight subjects had ultrasound studies at baseline, 2, and 4 years. Twenty-four drug and 22 placebo subjects had carotid ultrasound images at baseline, 2, and 4 years with matching cervical angiograms. Computer image processing was applied to ultrasound images of common carotid (far wall) and cervical angiograms. Computer operators were blind to treatment group. Carotid ultrasound measurements were tested for treatment effects and compared with measurements of atherosclerosis in coronary and cervical angiograms. Drug subjects showed significant progressive reduction in carotid thickness at 2 (P = .0001) and 4 years (P = .0001); placebo subjects significantly increased wall thickness at 2 and 4 years. Reduced levels of apolipoprotein B and increased levels of high density lipoprotein cholesterol and apolipoprotein C-III were significant predictors of carotid wall thinning. Ultrasound-measured carotid intima-media thickness was correlated at baseline with visually read coronary angiographic stenosis and at 2 years with a robust computer measurement of mild carotid atherosclerosis. CONCLUSIONS: Common carotid intima-media thickening can be reduced by colestipol-niacin treatment. Two-year image-processed carotid ultrasound trials can provide adequate power with 50 subjects per group to test for this treatment effect.

Adult↗
PubMed1993

One-year reduction and longitudinal analysis of carotid intima-media thickness associated with colestipol/niacin therapy.

BACKGROUND AND PURPOSE: The Cholesterol Lowering Atherosclerosis Study has reported significant reduction of coronary artery disease and of carotid arterial intima-media thickness (IMT) at 2 and 4 years with colestipol/niacin therapy. We now report on treatment effects on carotid IMT at 6 months and 1 year. METHODS: One hundred eighty-eight nonsmoking men, aged 40 to 59 years, with prior coronary artery bypass graft surgery were randomized to colestipol/niacin plus diet therapy or placebo plus diet therapy. Computerized image processing of carotid ultrasound films was used to measure IMT in the right common carotid artery. Treatment group comparisons were made at 6 months and 1 year (46 and 33 subjects, respectively, with baseline and 6-month or 1-year ultrasound measures). The time course of the treatment effect on carotid IMT was estimated using the complete sample of 78 subjects with baseline and on-trial data. RESULTS: No significant treatment group differences on carotid IMT were found at 6 months. At 1 year, the treated group showed significant reduction of carotid IMT (P = .01 between groups). The placebo group showed continuing progression of IMT during the 4-year study period (estimated progression rate, 0.018 mm/y). The treated group showed reduction of IMT during the first 3 years and a plateau during the remainder of the study. CONCLUSIONS: Reduction of carotid IMT was found with aggressive lipid-lowering therapy. Ultrasound measures of IMT offer a noninvasive and precise measure of early carotid atherosclerosis that will decrease sample size requirements, potentially decrease dropout rates, and widen the study population of antiatherosclerotic clinical trials.

Adult↗
PubMed1993

Nuclear proteins of the bovine esophageal epithelium. I. Monoclonal antibody W2 specifically reacts with condensed nuclei of differentiated superficial cells.

Cells from three layers of the bovine esophageal epithelium, representing different stages of differentiation, were dissociated and separated by Percoll gradient centrifugation into fractions of small, medium and large sizes. A majority of the large cells possessed condensed nuclei, a characteristic feature of terminal differentiation of the superficial epithelium. The small cells resembled the proliferate cells of the basal layer. In vitro culture of the esophageal epithelial cells resulted in proliferation of the small cells, colony formation, and, in some cases, differentiation into cells with condensed nuclei. Nuclei, or nuclear subfractions derived from cells of the different layers, were used as immunogens for the generation of hybridomas secreting monoclonal antibodies that bound specifically to different regions of the esophageal tissue. One such antibody, designated W2, labeled the condensed nuclei from the superficial layer of stratified esophageal and corneal epithelia in situ, as well as the large cells from esophageal culture in vitro. Thus, the expression of the W2 antigen may be associated with the process of nuclear condensation during epithelial differentiation. Immunoisolation of the target antigen of W2 from extracts of large cells of the bovine esophagus yielded a band of M(r) approximately 33,000 on nonreducing polyacrylamide gels. This band dissociated into two polypeptides, of M(r) approximately 22,000 and approximately 11,000, upon treatment with dithiothreitol. Amino acid sequence analysis of the larger polypeptide showed extensive homology to a group of small calcium-binding proteins, including two helix-turn-helix motifs designated as the EF-hand, characteristic of the configuration of the metal-ion coordinating ligands of the calcium-binding site. Similarly, the sequence at the amino terminus of the polypeptide of approximately 11,000 indicated that it was the light chain counterpart of the same calcium-binding protein complex.

Amino Acid Sequence↗
PubMed1993

X chromosome mosaicism in patients with recurrent abortion or premature ovarian failure.

X chromosome mosaicism is usually associated with abnormal sexual development and reproductive performance, such as recurrent spontaneous abortion, primary or secondary amenorrhea, infertility, and premature ovarian failure. However, there is a paucity of literature which discusses these relationships. From July 1988 to December 1992, a total of 105 couples with a history of recurrent spontaneous abortion from a genetic counseling clinic and 61 women with a history of premature ovarian failure followed up in reproductive endocrinology clinics were assembled, and chromosomal analysis of peripheral blood lymphocytes was carried out. X chromosome mosaicism was found in six individuals (2.9%) out of the 105 couples with recurrent spontaneous abortion, and in five (8.2%) out of 61 women with premature ovarian failure. The karyotypes were 45,X/46,XX/47,XXX in five cases, 45,X/46,X in four cases, and 46,XX/47,XXX in two cases. The cases of complex X chromosome mosaicism (45,X/46,XX/47,XXX) presented recurrent spontaneous abortion in four cases and premature ovarian failure in one case. The cases of mosaic Turner's syndrome (45,X/46,XX) presented premature ovarian failure in three cases and recurrent spontaneous abortion in one case. The two cases of mosaic triple-X syndrome (46,XX/47,XXX) presented with premature ovarian failure and recurrent spontaneous abortion, respectively. However, the ratio of mosaic cell lines does not correlate well with the phenotypic manifestations in our cases. Our preliminary data suggest that chromosomal analysis should be done routinely in every couple with recurrent spontaneous abortion and in women with premature ovarian failure. The reproductive performance of X chromosome mosaicism is highly variable and difficult to define.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Habitual↗