Upregulation of miR-142-5p induced by lipopolysaccharide contributes to apoptosis of hepatocytes and hepatic failure.

OBJECTIVE: This study was probed to uncover the mechanism of miR-142-5p in septic liver injury. MATERIALS AND METHODS: In this study, in-vitro and in-vivo models of sepsis were used. For in-vitro sepsis model, hepatocyte cell line (L02 cells) was treated with LPS (lipopolysaccharide). Whereas for in-vivo sepsis model, cecal ligation and puncture were performed in mice. Mice were assigned into three groups: control, CLP (Cecal Ligation Puncture), CLP + miR-142-5p inhibitor group. Liver injury was assessed via H&E staining. IL-6, TNF-α, and IL-1ß expressions were assayed through ELISA kits. C-caspase-9, C-caspase-3, ERK, p65, and IκBα expressions were determined via western blot and RT-qPCR. Apoptosis in LPS-induced L02 cells was detected by TUNEL staining. RESULTS: Our results show that miR-142-5p exhibited perspicuous upregulation in CLP mice tissues and LPS-induced L02 cells. On the other hand, inhibition of miR-142-5p could promote LPS-induced L02 cell activity and reduce apoptosis and inflammation. In terms of molecular mechanism, downregulation of miR-142-5p could abate sepsis-mediated acute hepatic injury by targeting SOCS1, through ERK and NF-κB pathway. CONCLUSIONS: Overall our results demonstrate that miR-142-5p inhibitors can mitigate septic liver injury by downregulating the inflammation and apoptosis via targeting SOCS1. Thus, miR-142-5p can serve a potential therapeutic target for sepsis mediated acute hepatic injury.

Clinical and radiological characteristics of COVID-19: a multicentre, retrospective, observational study.

BACKGROUND: Multicentre cohort investigations of patients with coronavirus disease 2019 (COVID-19) have been limited. We investigated the clinical and chest computed tomography characteristics of patients with COVID-19 at the peak of the epidemic from multiple centres in China. METHODS: We retrospectively analysed the epidemiologic, clinical, laboratory, and radiological characteristics of 189 patients with confirmed COVID-19 who were admitted to seven hospitals in four Chinese provinces from 18 January 2020 to 3 February 2020. RESULTS: The mean patient age was 44 years and 52.9% were men; 186/189 had ≥1 co-existing medical condition. Fever, cough, fatigue, myalgia, diarrhoea, and headache were common symptoms at onset; hypertension was the most common co-morbidity. Common clinical signs included dyspnoea, hypoxia, leukopenia, lymphocytopenia, and neutropenia; most lesions exhibited subpleural distribution. The most common radiological manifestation was mixed ground-glass opacity with consolidation (mGGO-C); most patients had grid-like shadows and some showed paving stones. Patients with hypertension, dyspnoea, or hypoxia exhibited more severe lobe involvement and diffusely distributed lesions. Patients in severely affected areas exhibited higher body temperature; more fatigue and dyspnoea; and more manifestations of multiple lesions, lobe involvement, and mGGO-C. During the Wuhan lockdown period, cough, nausea, and dyspnoea were alleviated in patients with newly confirmed COVID-19; lobe involvement was also improved. CONCLUSIONS: Among patients with COVID-19 hospitalised at the peak of the epidemic in China, fever, cough, and dyspnoea were the main symptoms at initial diagnosis, accompanied by lymphocytopenia and hypoxaemia. Patients with severe disease showed more severe lobe involvement and diffuse pulmonary lesion distribution.

LncRNA PEG10 aggravates cardiac hypertrophy through regulating HOXA9.

OBJECTIVE: To uncover the role of long non-coding RNA (lncRNA) PEG10 in the progression of cardiac hypertrophy by regulating HOXA9. MATERIALS AND METHODS: In vivo cardiac hypertrophy model was established by performing transverse aortic constriction model (TAC) procedures in mice. Relative levels of PEG10, ANP and BNP in mice undergoing TAC procedures or sham operations were determined. In vitro cardiac hypertrophy model was established by phenylephrine (PE) treatment in primary cardiomyocytes. Relative levels of PEG10, ANP and BNP in cardiomyocytes were determined as well. Regulatory effects of HOXA9 on surface area of cardiomyocytes and relative levels of ANP and BNP were assessed. Finally, potential influences of PEG10/HOXA9 regulatory loop on cell surface area and relative levels of ANP and BNP were explored. RESULTS: Compared with mice in sham group, those in TAC group presented higher levels of PEG10, ANP and BNP. PE treatment markedly upregulated PEG10, ANP and BNP in primary cardiomyocytes, which were downregulated by transfection of si-PEG10. Besides, surface area of cardiomyocytes was enlarged by PE treatment, which was reduced after silence of PEG10. Silence of HOXA9 presented a similar effect as that of PEG10 in cardiomyocytes. Transfection of si-HOXA9 reversed the expanded cell surface area, and upregulated ANP and BNP in cardiomyocytes overexpressing PEG10. CONCLUSIONS: PEG10 is upregulated in hypertrophic cardiomyocytes. PEG10 aggravates cardiac hypertrophy by positively regulating HOXA9.

Diminutive Incision Acromioplasty Assisted with Arthroscopy in the Treatment of Chinese Patients with Subacromial Impingement Syndrome / Acromioplastia de Incisión Diminuta Asistida con Artroscopia en el Tratamiento de Pacientes Chinos con Síndrome de Pinzamiento Subacromial

ABSTRACT Background: Many causes can lead to shoulder pain and subacromial impingement syndrome (SIS) is the most frequently recorded disorders. The aim of this study was to evaluate the clinical effects of diminutive incision acromioplasty assisted with arthroscopy for the treatment of Chinese patients with subacromial impingement syndrome. Subject and Methods: Twenty-two patients with 24-painful shoulders subacromial impingement syndrome were enrolled. All painful shoulders were in Grades II (8) and III (16) according to Neer's classification. Detailed physical examination was performed. Conventional radiography and subsequent magnetic resonance imaging (MRI) of the shoulder region of all patients were done. The University of California at Los Angeles Shoulder (UCLA) score system was used for all patients to evaluate their satisfaction after surgery. The preoperative recordings of the UCLA scores were collected and all enrolled cases including 24-painful shoulders were available for follow-up in 1, 3, 6, 12 months after surgery. Results: According to the UCLA scoring system, the symptom of all painful shoulders were improved after one year postoperatively. The average score before surgery from 15.4 points increased to 31.2 points postoperatively, showing a statistical difference (p < 0.05). Conclusions: A diminutive incision acromioplasty assisted with arthroscopy is a reliable approach to treat Chinese patients with subacromial impingement syndrome. All painful shoulders were obviously improved in one year after surgery.

ABSTRACT Antecedentes: Muchas causas pueden provocar dolor de hombro y síndrome de compresión subacromial (SIS) es el trastorno más frecuentemente registrado. El objetivo de este estudio fue evaluar la clínica. Efectos de la acromioplastia con incisión diminuta asistida con artroscopia para el tratamiento de Pacientes chinos con síndrome de pinzamiento subacromial. Sujeto y métodos: Se incluyeron veintidós pacientes con síndrome de afectación subacromial de 24-hombros dolorosos. Todos los hombros dolorosos estaban en Grados II (8) y III (16) de acuerdo con la clasificación de Neer. Se realizó examen físico detallado. Se realizaron radiografías convencionales y, posteriormente, imágenes de resonancia magnética (IRM) de la región del hombro de todos los pacientes. El sistema de puntuación de la Universidad de California en Los Angeles Shoulder (UCLA) se utilizó para que todos los pacientes evaluaran su satisfacción después de la cirugía. Los registros preoperatorios de las puntuaciones de UCLA se recopilaron y todos los casos incluidos, incluidos 24-hombros dolorosos, estaban disponibles para el seguimiento en 1, 3, 6 y 12 meses después de la cirugía. Resultados: De acuerdo con el sistema de puntuación de UCLA, el síntoma de todos los hombros dolorosos mejoró después de un año después de la operación. La puntuación promedio antes de la cirugía de 15.4 puntos aumentó a 31.2 puntos después de la operación, mostrando una diferencia estadística (p < 0.05) Conclusiones: Una acromioplastia de incisión diminuta asistida con artroscopia es un enfoque confiable para tratar a pacientes chinos con síndrome de pinzamiento subacromial. Todas las lesiones dolorosas se mejoraron obviamente en un año después de la cirugía.

Treatment strategies for early neurological deficits related to malpositioned pedicle screws in the lumbosacral canal: A pilot study.

OBJECTIVES: To employ a simple and fast method to evaluate those patients with neurological deficits and misplaced screws in relatively safe lumbosacral spine, and to determine if it is necessary to undertake revision surgery. METHODS: A total of 316 patients were treated by fixation of lumbar and lumbosacral transpedicle screws at our institution from January 2011 to December 2012. We designed the criteria for post-operative revision scores of pedicle screw malpositioning (PRSPSM) in the lumbosacral canal. We recommend the revision of the misplaced pedicle screw in patients with PRSPSM = 5' as early as possible. However, patients with PRSPSM < 5' need to follow the next consecutive assessment procedures. A total of 15 patients were included according to at least three-stage follow-up. RESULTS: Five patients with neurological complications (PRSPSM = 5') underwent revision surgery at an early stage. The other ten patients with PRSPSM < 5' were treated by conservative methods for seven days. At three-month follow-up, only one patient showed delayed onset of neurological complications (PRSPSM 7') while refusing revision. Seven months later, PRSPSM decreased to 3' with complete rehabilitation. CONCLUSIONS: This study highlights the significance of consecutively dynamic assessments of PRSPSMs, which are unlike previous implementations based on purely anatomical assessment or early onset of neurological deficits.and also confirms our hypothesis that patients with early neurological complications may not need revision procedures in the relatively broad margin of the lumbosacral canal.Cite this article: X-J. Lin. Treatment strategies for early neurological deficits related to malpositioned pedicle screws in the lumbosacral canal: A pilot study. Bone Joint Res 2016;5:46-51.

Inhibition of CD44 expression by small interfering RNA to suppress the growth and metastasis of ovarian cancer cells in vitro and in vivo.

Since ovarian cancer cells express CD44, which causes very strong cell adhesion to peritoneal mesothelium and an unfavourable prognosis, we designed small interfering RNA (siRNA) targeting the CD44 gene to analyse the functional consequences of this inhibition in human ovarian cancer. We transfected ovarian cancer cell line SKOV-3 with well-designed CD44 siRNA or control siRNA. Western blot analysis was used to assess the CD44 expression. Following stable transfection, significant inhibition of CD44 expression with 66.13 +/- 4.21 % (P < 0.05) in CD44 siRNA1 cells and 62.01 +/- 3.97 % (P < 0.05) in CD44 siRNA2 cells was detected. We performed in vitro experiments including cellular adhesion to hyaluronan and human peritoneal mesothelial cells, etoposide-induced apoptosis, and Boyden chamber invasion assays. The adhesion percentages of CD44 siRNA1 and CD44 siRNA2 cells were significantly lower than those of the control siRNA cells in adhesion both to hyaluronan and to human peritoneal mesothelium. The CD44 siRNA transfectants showed significant inhibition of in vitro invasion and loss of resistance to apoptosis than the control siRNA cells. In vivo study with BALB/c mice was applied to compare the tumour growth and peritoneal dissemination. Nude mice treated with CD44 siRNA cells revealed significantly lower tumour volume and less peritoneal dissemination compared to mice treated with the control siRNA cells. In conclusion, downregulation of CD44 expression by siRNA inhibits the in vitro adhesion, invasion and resistance to apoptosis of ovarian cancer cells, suppresses tumour growth and peritoneal dissemination of human ovarian cancer xenograft in nude mice.

Pregnancy outcome and prognosis in fetuses with increased first-trimester nuchal translucency.

OBJECTIVE: One of the concerns of prenatal diagnosis is to find sensitive markers to screen for chromosome abnormalities, such as serum assays or nuchal translucency (NT). This study reports our experience with NT measurement during the first trimester of pregnancy. MATERIALS: The study was performed prospectively on 252 fetuses with either NT > or =3 mm or cystic hygroma. RESULTS: We observed 50 abnormal karyotypes, i.e. 19.8%. The incidence of chromosome abnormalities increased with increasing maternal age and increasing NT thickness. For the 202 fetuses with normal karyotypes, outcome was unfavourable in 32 cases: 23 elective terminations of pregnancy, 8 spontaneous abortions and 1 neonatal death. Outcome was favourable in 141 cases. Twenty-nine pregnancies were lost to follow-up. CONCLUSION: Measurement of NT at 12 weeks' gestation seems to be a good marker for chromosome abnormalities. When the karyotype is normal, the pregnancy outcome remains correlated with the degree of NT thickness. The finding of NT >3 mm between 10 and 14 weeks' gestation dictates rigorous ultrasound monitoring and caution when predicting pregnancy outcome.

Structure and organization of bacteriophage Pf3 probed by Raman and ultraviolet resonance Raman spectroscopy.

The Pseudomonas bacteriophage Pf3 is a long and narrow filament consisting of a covalently closed DNA single strand of 5833 bases sheathed by approximately 2500 copies of a 44-residue subunit. Ultraviolet resonance Raman spectra excited at 257, 244, 238, and 229 nm and off-resonance Raman spectra excited at 514.5 nm are reported for Pf3 in both H2O and D2O solutions. The key Raman bands are assigned to specific protein and DNA groups of the native virion assembly. The results are compared with proposed assembly models and Raman spectra recently reported for the isomorphous (class II) Pseudomonas phage Pf1 and the morphologically distinct (class I) coliphage fd [Wen, Z. Q., Overman, S. A., and Thomas, G. J. , Jr. (1997) Biochemistry 36, 7810-7820; Wen, Z. Q., Armstrong, A., and Thomas, G. J., Jr. (1999) Biochemistry 38, 3148-3156]. Surprisingly, deoxynucleosides of the packaged DNA genome of Pf3 adopt the same conformation (C3'-endo/anti) found for DNA packaged in the class I fd virion rather than that (C2'-endo/anti) associated with DNA in the isomorphous Pf1 virion. However, DNA base stacking in Pf3, as judged by Raman hypochromic effects, differs significantly from that occurring in either Pf1 or fd. Thus, the single-stranded DNA genomes of Pf3, Pf1, and fd are all organized differently within their respective capsids, implying that local subunit-DNA interactions may be important in determining the structure specific to each native assembly. The present study confirms a completely alpha-helical secondary structure for the Pf3 subunit and an unusual indolyl ring environment for the subunit tryptophan residue (Trp-38).

Ultraviolet-resonance raman spectroscopy of the filamentous virus Pf3: interactions of Trp 38 specific to the assembled virion subunit.

The class II filamentous virus Pf3 packages a circular single-stranded DNA genome of approximately 5833 [corrected] nucleotides within a cylindrical capsid constructed from approximately 2500 [corrected] copies of a 44 residue alpha-helical subunit. The single tryptophan residue (Trp 38) of the capsid subunit is located within a basic C-terminal sequence (.R(+)WIK(+)AQFF). The local environment of Trp 38 in the native Pf3 assembly has been investigated using 229 nm excited ultraviolet-resonance Raman (UVRR) spectroscopy and fluorescence spectroscopy. Trp 38 exhibits an anomalous UVRR signature in Pf3, including structure-diagnostic Raman bands (763, 1228, 1370, and 1773 cm(-)(1)) that are greatly displaced from corresponding Raman markers observed in either detergent-disassembled Pf3, class I filamentous viruses, most globular proteins, or aqueous L-TRP. An unusual and highly quenched fluorescence spectrum is also observed for Trp 38. These distinctive UVRR and fluorescence signatures together reflect interactions of the Trp 38 side chain that are specific to the native PF3 assembly. The experimental results on PF3 and supporting spectroscopic data from other proteins of known three-dimensional structure favor a model in which pi electrons of the Trp 38 indolyl ring interact specifically with a basic side chain of the subunit C-terminal sequence. Residues Arg 37 AND Lys 40 are plausible candidates for the proposed cation-pi interaction of Trp 38. The present study suggests that raman spectroscopy may be a generally useful probe of interactions between the indolyl pi-electron system of tryptophan and electropositive groups in proteins and their assemblies.

Demonstration by ultraviolet resonance Raman spectroscopy of differences in DNA organization and interactions in filamentous viruses Pf1 and fd.

Pf1, a class II filamentous virus, has been investigated by ultraviolet resonance Raman (UVRR) spectroscopy with excitation wavelengths of 257, 244, 238, and 229 nm. The 257-nm UVRR spectrum is rich in Raman bands of the packaged single-stranded DNA (ssDNA) genome, despite the low DNA mass (6%) of the virion. Conversely, the 229-nm UVRR spectrum is dominated by tyrosines (Tyr 25 and Tyr 40) of the 46-residue alpha-helical coat subunit. UVRR spectra excited at 244 and 238 nm exhibit Raman bands diagnostic of both viral DNA and coat protein tyrosines. Raman markers of packaged Pf1 DNA contrast sharply with those of the DNA packaged in the class I filamentous virus fd [Wen, Z. Q., Overman, S. A., and Thomas, G. J., Jr. (1997) Biochemistry 36, 7810-7820]. Interestingly, deoxynucleotides of Pf1 DNA exhibit sugars in the C2'-endo/anti conformation and bases that are largely unstacked, compared with C3'-endo/anti conformers and very strong base stacking in fd DNA; hydrogen-bonding interactions of thymine carbonyls are also different in Pf1 and fd. On the other hand, coat protein tyrosines of Pf1 exhibit Raman markers of ring environment identical to those of fd, including an anomalous singlet at 853 cm-1 in lieu of the canonical Fermi doublet (850/830 cm-1) found in globular proteins. The results indicate markedly different modes of organization of ssDNA in Pf1 and fd virions, despite similar environments for coat protein tyrosines, and suggest strong hydrogen-bonding interactions between DNA bases and coat subunits of Pf1 but not between those of fd. We propose that structural relationships between the protein coat and encapsidated ssDNA genome are also fundamentally different in the two assemblies.

Submicroscopic deletion of chromosome 16p13.3 in patients with Rubinstein-Taybi syndrome.

The Rubinstein-Taybi syndrome (RTS) is a well-defined entity characterized by growth and mental retardation, broad thumbs and halluces, and typical face. The RTS locus was assigned to 16p13.3, and interstitial submicroscopic deletions of this region (RT1 cosmid, D16S237) were initially identified in 25% of RTS patients. The gene for the human CREB binding protein, the transcriptional coactivator CBP, is included in the RT1 cosmid, and mutations in CBP have recently been identified in nondeleted RTS patients. We investigated 30 French patients with RTS. Among these patients, 3 had the RT1 microdeletion (frequency 10%). There is no obvious phenotypic difference between the patients with and without the RT1 deletion. The RT1 probe appears useful for confirmation of the diagnosis but is of little interest as a screening tool. By pooling data including the previous series and our current series, the cumulative frequency of the 16p13.3 microdeletion is 11.9% (19 in 159). This frequency of approximately 12% deleted patients appears more accurate than the 25% previously reported. Molecular investigations of CBP are in process in our series to clarify the cause of RTS.

UV resonance Raman spectroscopy of DNA and protein constituents of viruses: assignments and cross sections for excitations at 257, 244, 238, and 229 nm.

Ultraviolet resonance Raman (UVRR) spectra of H2O and D2O solutions of the nucleoside (dA, dG, dC, dT) and aromatic amino acid (Phe, Trp, Tyr) constituents of DNA viruses have been obtained with laser excitation wavelengths of 257, 244, 238, and 229 nm. Using the 981 cm-1 marker of Na2SO4 as an internal standard, Raman frequencies and scattering cross sections were evaluated for all prominent UVRR bands at each excitation wavelength. The results show that UVRR cross sections of both the nucleosides and amino acids are strongly dependent on excitation wavelength and constitute sensitive and selective probes of the residues. The results provide a library of UVRR marker bands for structural analysis of DNA viruses and other nucleoprotein assemblies.

Structure and interactions of the single-stranded DNA genome of filamentous virus fd: investigation by ultraviolet resonance raman spectroscopy.

The filamentous bacteriophage fd is a member of the Ff class of Inovirus, which includes phages f1 and M13. Ultraviolet resonance Raman (UVRR) spectra of fd have been obtained using excitation wavelengths of 257, 244, 238, and 229 nm. Excitation at 257 nm selectively enhances Raman markers of the packaged single-stranded (ss) DNA genome, while excitation at the shorter wavelengths favors the detection of Raman signals from coat protein aromatics, particularly tryptophan (W26) and tyrosine residues (Y21 and Y24) of the viral coat subunit (pVIII). The principal findings are the following: (1) Distinctive markers of dA, dC, dG, and dT residues of the packaged genome are identified in UVRR spectra of fd excited at 257 and 244 nm, despite the low DNA mass composition (12%) of the virion. (2) Raman bands of the bases of packaged ssDNA show extraordinary resonance Raman hypochromism. Raman intensity losses as large as 80% of the parent DNA nucleotide intensities are observed. This is interpreted as evidence of extensive short-range interactions involving bases of the packaged genome. (3) Conversely, Raman bands of tryptophan and tyrosine residues of the coat protein generally exhibit strong hyperchromism. Typically, Raman markers of the aromatic amino acids are about 3-fold more intense in the UVRR spectrum of fd than in spectra of the free amino acids. The very high Raman cross sections for residues Y21, Y24, and W26 are indicative of unusual hydrophobic environments in the viral assembly. (4) UVRR band shifts that accompany the transfer of fd from H2O to D2O solution indicate that bases of the packaged ssDNA are readily exchanged by the solvent. Similarly, the indole N1H group of W26 is accessible to solvent, as shown by N1H --> N1D exchange in D2O solution. (5) The UVRR markers of the packaged fd genome confirm the conclusion reached previously from off-resonance Raman studies that fd DNA nucleosides favor the C3'-endo/anti conformation, rather than the C2'-endo/anti conformation that is characteristic of the lowest energy structure of DNA. We conclude that nucleoside conformations of the packaged fd genome are influenced by the specific organization of ssDNA and coat protein subunits in the native virion assembly.

18p monosomy with midline defects and a de novo satellite identified by FISH.

We report a girl with an 18p deletion and showing a total GH deficiency, a single central maxillary incisor, and a pituitary dysplasia. This suggests that del(18)(p) could be involved in pituitary dysplasia. We review the association between midline developmental defects and chromosome 18 anomalies. This case is due to a de novo satellite resulting from an unbalanced translocation t(18p;13p) identified by FISH. This is the first case of this cytogenetic mechanism in the 18p monosomy.

Vibrational Raman optical activity of alpha-lactalbumin: comparison with lysozyme, and evidence for native tertiary folds in molten globule states.

Proteins in aqueous solution are now accessible to Raman optical activity (ROA) measurements, which provide an incisive new probe of secondary and tertiary structure illustrated here by a study of bovine alpha-lactalbumin. The room-temperature ROA spectrum of native bovine alpha-lactalbumin is similar to that of native hen egg-white lysozyme except for features attributable to differences in the loop regions: in particular, a positive ROA band at approximately 1338 cm-1 assigned to conformationally homogeneous loop structure, possibly with local order corresponding to 3(10)-helix, has more than double the intensity in alpha-lactalbumin compared with lysozyme. This is consistent with the two proteins having similar secondary structure but different local details in the tertiary fold. ROA measurements on alpha-lactalbumin at pH 2.0 over a range of temperatures have provided a new perspective on the molten globule state. Thus at 35 degrees C ROA reveals the presence of some secondary structure but an almost complete loss of the tertiary loop structure; whereas at 2 degrees C the ROA spectrum is almost identical with that of the native protein, which is strong evidence that virtually all of the secondary structure and the tertiary backbone fold persist, albeit within a looser framework associated with increased solvent exposure and change of environment of many of the side-chains as evidenced by an increase in noise and bandwidth of some of the ROA signals together with aromatic fluorescence and near-UV circular dichroism signals characteristic of the molten globule state. Our sample of acid alpha-lactalbumin at 2 degrees C therefore appears to be an archetypal example of Ptitsyn's "native-like" molten globule, having a fixed native-like tertiary fold but with loss of tight packing of the side-chains; whereas at 35 degrees C it is a "disordered" molten globule. At 20 degrees C the acid molten globule appears to retain highly native-like secondary structure but with most of the tertiary fold already lost. A calcium-free sample of alpha-lactalbumin at neutral pH displayed a broad cooperative transition between native and molten globule states at approximately 15 degrees C, with the latter state showing similar but somewhat degraded tertiary loop ROA signatures to the native protein. In both the acid and apo molten globule states the ROA signatures of the secondary structure and the tertiary loops showed a gradual change with temperature.

Prenatal diagnosis of trisomy 9. Six cases and a review of the literature.

Six prenatally diagnosed cases of trisomy 9 are reported and 22 previously reported cases are reviewed; the difficulty of genetic counselling for such cases and the variation in the percentage of trisomic cells in different tissues, thus making accurate diagnosis of trisomy 9 difficult, are emphasized. In addition to karyotyping results, ultrasound findings are important in achieving diagnoses. Finally, a course of action when prenatal trisomy 9 is detected is proposed.

Beta-sheet and associated turn signatures in vibrational Raman optical activity spectra of proteins.

We have measured the aqueous solution vibrational Raman optical activity (ROA) spectra of concanavalin A, alpha-chymotrypsin, and beta-lactoglobulin, all of which are rich in beta-sheet, together with that of the model beta-turn peptide L-pro-L-leu-gly-NH2. Possible ROA signatures of antiparallel beta-sheet include a strong sharp positive band at approximately 1,313 cm-1 associated with backbone amide III C alpha H and NH deformations, and an amide I couplet, negative at low wavenumber and positive at high, centered at approximately 1,658 cm-1. Negative ROA bands in the range approximately 1,340-1,380 cm-1, which might originate in glycine CH2 deformations, appear to be characteristic of beta-turns. Our results provide further evidence that ROA is a more incisive probe of protein conformation than conventional vibrational spectroscopy, infrared, or Raman, because only those few vibrational coordinates within a given normal mode that sample the skeletal chirality directly contribute to the corresponding ROA band intensity.