[Application of multiple post labeling delay time arterial spin labeling imaging in the quantitative blood flow analysis of brain subregions in healthy adults]

Objective: To explore the normal ranges of perfusion parameters between cerebral hemisphere, cerebellar hemisphere and brain anatomical subregions (56 pairs) in different gender and age groups with multiple post labeling delay time (Multi-PLD) arterial spin labeling (ASL) imaging. Methods: From November 2020 to December 2020, 42 healthy adult volunteers (Male 25, Female 17) were recruited to perform 7 PLD ASL imaging, including 21 young adults (15 males and 6 females, aged 23-35 years) and 21 seniors (10 males and 11 females, aged 36-74 years). The data was processed offline by Cereflow software to obtain arterial arrival time (ATT) and corrected cerebral blood flow (CBF) and cerebral blood volume (CBV) perfusion parameters. SimpleITK standardization function was used to standardize the calculated perfusion image according to the anatomical automatic labeling (AAL) template. Therefore, CBF, ATT, CBV perfusion values of brain subregions were obtained. Paired samples t test, Wilcoxon rank sum test, independent samples t test and Mann-Whitney U test were used to compare the differences of perfusion parameters in the cerebral hemisphere, the cerebellar hemisphere, brain subregions depending on side, gender and age. Pearson correlation analysis was used to compare the correlations of perfusion parameters with age. Results: CBF in 62.5% (35/56) subregions and CBV in 44.6% (25/56) subregions were higher in right side than those in left side. ATT in most brain anatomical subregions (16/56) were higher in left side. The CBF [(35.30±8.31) vs. (34.34±7.53) ml·100g^-1·min^-1, P=0.021], CBV [(0.47±0.11) vs. (0.45±0.09) ml/100g, P<0.001], ATT [(1.30±0.10) vs. (1.24±0.11) s, P<0.001] in left cerebellar hemisphere were higher than that of right side. The CBF (28/56) of cerebral hemisphere, cerebellar hemisphere and brain subregions was higher in females than that in males, while ATT in 83.9% (47/56) subregions was lower than that in males (all P<0.05). CBV in female subjects was higher only in 5 brain regions (superior occipital gyrus, middle occipital gyrus, inferior occipital gyrus, superior parietal gyrus and cerebelum_7b) (all P<0.05). In young subjects, CBF in 44.6% (25/56) subregions and CBV in 33.9% (19/56) subregions were higher than those in the senior group (all P<0.05). The ATT in most subregions in young group were lower than those in senior group, but the difference was statistically significant only in rectus gyrus (P=0.026) and paracentral lobule (P=0.006). The CBF (r=-0.430, P=0.005) and CBV (r=-0.327, P=0.035) of cerebral hemisphere were negatively correlated with age. The CBF (24/25, r range:-0.497 --0.343, all P<0.05) and CBV (16/19, r range:-0.474 --0.322, all P<0.05) in most subregions were negatively correlated with age, while ATT was positively correlated (gyrus rectus: r=0.311, P=0.045; paracentral lobule: r=0.392, P=0.010). Conclusions: Multi-PLD ASL imaging could be applied for quantitative analysis of brain perfusion. The perfusion parameters of anatomical subregions are different depending on side, gender, and age.

[The application of intravoxel incoherent motion diffusion imaging and 3D arterial spin labeling perfusion imaging in the evaluation of acute cerebral infarction]

Objective: To investigate the clinical value of magnetic resonance (MR) intravoxel incoherent motion (IVIM) diffusion imaging and 3D pseudo continuous arterial spin labeling (3D-pcASL) perfusion imaging in the evaluation of acute cerebral infarction. Methods: MR images of 49 patients with unilateral acute cerebral infarction diagnosed and treated in Affiliated Yancheng Hospital of Southeast University Medical College from October 2015 to February 2019 were retrospectively analyzed. High signal infarction area (S(D)) on diffusion image slice with the biggest lesion level and abnormal perfusion area (S(CBF)) on the corresponding level were measured. The presence of ischemic penumbra (IP) was represented by S(CBF)> S(D), and patients were divided into group IP and group non-IP. Regions of interest were set on the infarction core, brain tissue near the edge of the lesion (BNL) and their corresponding contralateral regions. The values of apparent diffusion coefficient (ADC), true diffusion coefficient (D), perfusion related diffusion coefficient (D(*)), perfusion fraction (f) and cerebral blood flow (CBF) of each region of interest were recorded and relative values of infarction lesion to its contralateral region (rADC, rD, rD(*), rf, rCBF) were calculated. Differences of each parameter value between infarction core, BNL and their corresponding contralateral regions and of each relative parameter value between infarction core and BNL, and between the two groups were compared.The differential diagnostic efficacy of relative parameter value with differences between groups was analyzed by receiver operating characteristics (ROC) curve. The correlations of each relative parameter value of 3D-pcASL and IVIM sequences were analyzed. Results: The ADC, D, f and CBF values of infarction core were significantly lower than those of contralateral regions in both groups (all P<0.01). Among all parameters of BNL in both groups, only the CBF value of group IP was significantly lower than that of contralateral region ((27.58±3.53) vs (41.20±5.66) ml·100 g(-1)·min(-1), P<0.01). The rADC, rD, rf and rCBF of infarction core were significantly lower than those of BNL in both groups (all P<0.01). The rCBF of BNL in group IP was significantly lower than that in group non-IP (0.68±0.12 vs 0.97±0.15, P<0.01), and the area under the curve was 0.949, the optimal threshold was 0.823, and the youden index was 0.855 for identifying the two groups. Other relative parameters values of infarction core and BNL had no statistical difference between the two groups. There were positive correlations between rCBF and rADC, rD, rf (r=0.428,0.335,0.565) of infarction core, rADC and rD, rf (r=0.853,0.602) of infarction core, also rADC and rD (r=0.336) of BNL (all P<0.05). Conclusions: IVIM can effectively evaluate the difusion and perfusion information of acute cerebral infarction lesions. However, its perfusion related parameters are not as good as 3D-pcASL in IP evaluation, which should be flexibly selected according to the actual needs of patients' condition evaluation.

[Association between gestational weight gain and adverse pregnancy outcomes: a prospective study]

Objective: To explore the association between gestational weight gain (GWG) and adverse pregnancy outcomes. Methods: A prospective study was conducted among 1 220 healthy singleton pregnant women in the first trimester of pregnancy, from Chengdu city, Sichuan province. Pre-gestational body mass and other basic information were collected through a set of questionnaires. Weight at the last week before delivery was measured and GWG was classified by IOM criteria (2009). Related information on pregnancy outcomes was collected after delivery, through the hospital information system. Multiple non-conditional logistic regression models were used to test the association between GWG and adverse pregnancy outcomes. Results: In total, data on 1 045 pregnant women were analyzed. Compared with adequate GWG, excessive GWG was associated with the increased risks of cord entanglement and large for gestational age (OR=1.641, 95%CI: 1.197-2.252; OR=1.678, 95%CI: 0.132-2.488), respectively. Additionally, when compared with the adequate GWG, insufficient GWG was associated with the increased risk of preterm delivery (OR=3.189, 95%CI: 1.604-6.341). Conclusions: Both excessive and insufficient GWG appeared associated with the pregnancy outcomes. Weight monitoring should be strengthened for pregnant women to reduce related risks on adverse pregnancy outcomes.

[The combined application of magnetic resonance DTI and 3D-pcASL in differential diagnosis of hyper-acute and acute ischemic cerebral infarction]

Objective: To explore the clinical value of magnetic resonance diffusion tensor imaging (DTI) combined with 3D pseudo continuous arterial spin labeling (3D-pcASL) perfusion imaging in differential diagnosis of hyper-acute and acute ischemic cerebral infarction. Methods: A total of 42 patients with confirmed unilateral ischemic cerebral infarction from February 2015 to October 2017 of Affiliated Yancheng Hospital of Southeast University Medical College were collected. DTI and 3D-pcASL images of hyper-acute (14 patients, group A) and acute (28 patients, group B) ischemic cerebral infarction were retrospectively analyzed. The slice with the biggest lesion on diffusion weighted imaging (DWI) was selected to measure the infarction area (S(DWI)) and abnormal cerebral blood flow (CBF) perfusion area (S(CBF)). Regions of interest (ROIs) were set on the infarction core (IC) area, mismatch area of S(CBF) and S(DWI) (MACD), and their corresponding contralateral regions. The values of CBF, average diffusion coefficient (DC(avg)), and fractional anisotropy (FA) parameter images in these ROIs in patients with both S(CBF)>S(DWI) and lower perfusion in the IC were recorded. The relative values of each infarction lesion to its corresponding contralateral region (rCBF, rFA, and rDC(avg)) were calculated. Differences of each parameter value between the IC, MACD and their corresponding contralateral regions and of the relative values between group A and group B were investigated. Results: The CBF and DC(avg) values in the IC and the CBF value in the MACD were lower than that of their corresponding contralateral regions in both groups (P<0.05). The DC(avg) in the MACD in group A patients and the FA in the IC in group B patients were lower than that in their corresponding contralateral regions (P<0.05). Compared to group A patients, group B patients showed decreased rFA, rDC(avg) in the IC and rFA in the MACD, and increased rDC(avg) and rCBF in the MACD (P<0.05). Receiver operating characteristics (ROC) curve analysis indicated that the best diagnosis cut off values of the rFA and rDC(avg) values in the IC and the rCBF, rFA, and rDC(avg) values in the MACD were 0.890 and 0.541 and 1.139, 0.902 and 0.455, respectively, for identifying two groups. Conclusion: The changes of the CBF, FA, and DC(avg) values and their relative values can be applied to differentially diagnose patients with hyper-acute and acute cerebral infarction, which could provide the basis for selecting more reasonable treatment protocols.

[Association between gestational weight gain per trimester/total gestational weight gain and gestational diabetes mellitus]

Objective: To understand the association between gestational weight gain (GWG) per trimester/total (GWG) and gestational diabetes mellitus (GDM). Methods: A prospective cohort study was conducted among 829 healthy pregnant women from Chengdu who delivered a singleton during March-September 2013. Basic information about pre-pregnancy was collected at the first time, exercise information per trimester, dietary intake information per trimester and gestational age at delivery were obtained by questionnaire. Weight at the (12 ± 1)^th, (28 ± 1)^th, (36 ± 1)^th and last week before delivery were measured. GDM was diagnosed according to the National Diabetes and Pregnancy Prevention Guidelines (2014). At last, a total of 682 pregnant women were analyzed. After controlling the potential confounders, multiple logistic regression models were used to test the associations between GWG per trimester/total GWG and GDM. Results: After adjusting for age at delivery, pre-pregnancy body mass index, family histories of type 2 diabetes and hypertension, exercise in the first trimester, parity and energy intake in trimester and other potential confounders. Compared with adequate GWG in the first trimester, insufficient and excessive GWG in the first trimester were associated with increased risk of GDM (OR=1.23, 95%CI: 0.63-2.38, and OR=2.20, 95%CI: 1.12-4.35). Compared with adequate GWG in the second trimester, insufficient and excessive GWG in the second trimester were associated with decreased risk of GDM (OR=0.47, 95%CI: 0.18-1.19, and OR=0.78, 95% CI: 0.43-1.42). Compared with adequate GWG in the third trimester, insufficient GWG in the third trimester was associated with increased risk of GDM (OR=1.48, 95%CI: 0.77-2.84), excessive GWG in the third trimester was associated with decreased risk of GDM (OR= 0.53, 95% CI: 0.28-0.99). Compared with adequate total GWG in pregnancy, insufficient GWG in pregnancy was associated with increased risk of GDM (OR=2.16, 95% CI: 1.04-4.46), excessive GWG in pregnancy was associated with decreased risk of GDM (OR=0.74, 95% CI: 0.38-1.46). Conclusions: Insufficient and excessive GWG in the first trimester were associated with increased risk of GDM, the first trimester may represent a critical period for risk of GDM. The effects of GWG in the second and third trimester on GDM need further study.

[Endovascular implantation of iodine-125 seeds strand and portal vein stenting followed by transcatheter arterial chemoembolization combined therapy with sorafenib for hepatocellular carcinoma with main portal vein tumor thrombus]

OBJECTIVE

To compare the therapeutic effect of portal vein stenting and endovascular implantation of iodine-125 seeds strand followed by transcatheter arterial chemoembolization combined with or without sorafenib in patients for hepatocellular carcinoma (HCC) with main portal vein tumor thrombus (MPVTT).

METHODS

A total of 53 patients with HCC complicated by MPVTT who received portal vein stenting and endovascular implantation of iodine-125 seeds strand followed by transcatheter arterial chemoembolization combined without (group A, n=38) or with (group B, n=15) sorafenib in Affiliated Yancheng Hospital of Southeast University Medical College during January 2010 and August 2015 were analyzed retropectively.Overal survival, progress free survival and procedure-related adverse event were compared between the two groups.

RESULTS

The technical success rate was 100% for placement of (125)I seeds strand and stent in the obstructed main portal vein.No serious procedure-related adverse events occurred. Median survival time of group A and B were 12.1 and 14.8 months, respectively (P=0.037). Additionally, Median progress free survival time of group A and B were 2.8 and 4.0 months, respectively (P=0.002).

CONCLUSIONS

Endovascular implantation of iodine-125 seeds strand and portal vein stenting followed by transcatheter arterial chemoembolization combined with sorafenib could improve the survival time, the progress free survival time of patients with HCC complicated by MPVTT.

[Photodynamic therapy by topical drup for the treatment of juvenile onset laryngeal papillomatosis]

Objective:To observe the therapeutic effect of photodynamic therapy(PDT) on the treatment of juvenile onset laryngeal papillomatosis. Method:Twenty-eight cases of children with laryngeal papilloma were treated,only 2 cases for the first time, and the rest were repeatedly treated outside our hospital, the average hospital surgery were more than 4 times. Under self retaining laryngoscope and microscope and endoscope assisted by semiconductor laser and plasma and cold instrument method，visible tumor resection and local affixed deposited 20% 5-aminolevulinic acid(photosensitizer) 3 hours later, with 635 nm semiconductor laser photodynamic,200-280 mW and can volume density of 80 to 120 J/cm², 20 min irradiation. PDT should be repeated after 25 days until no visible tumor.Then,2 times PDT must be done. Result:In 28 cases, 24 cases were followed up for more than 1 years(12 cases were followed up for 3 years),19 had no recurrence, the cure rate was 79.2%(19/24)；5 cases recurrence, and the recurrence rate was 20.8%(5/24)，among them,2 cases were abandoned because of the relapse，the other 3 cases were cure after 3 times of PDT.The main complications were adhesion of larynx. Conclusion:The preliminary effect of PDT by topical drug for the treatment of juvenile onset laryngeal papillomatosis is encouraging. The principle of PDT and the principle of the recurrence of laryngeal papilloma in children were also introduced in this paper.

Comparison of high-intensity focused ultrasound therapy under nasal endoscopy guidance versus first-line drug treatment in patients with persistent allergic rhinitis

The aim of this study was to determine whether high-intensity focused ultrasound (HIFU) therapy under nasal endoscopy guidance could provide better efficacy and safety in patients with persistent allergic rhinitis (PAR) than the first-line drugs recommended by the World Health Organization. A total of 120 adult patients with PAR were randomly divided into 2 groups (N = 60 each). One group underwent HIFU therapy under nasal endoscopy guidance using an ultrasound rhinitis therapeutic machine. The other group served as the control group and was treated with corticosteroid nasal spray and oral cetirizine hydrochloride. All patients underwent follow-up treatment for 1 year, after which the efficacy and safety were evaluated. There was no significant difference between the two groups (P > 0.05) in the total effective rate. Moreover, no complications such as nasal adhesion, septal perforation, mucosal atrophy, and hyposmia were observed, indicating that HIFU was as effective as the first-line drug treatments recommended by the World Health Organization for symptom relief in PAR patients. The treatment efficacy, repeatability, safety, economical aspects, ease of performance, and few complications of HIFU therapy strongly suggest that HIFU should be routinely incorporated into clinical practice.

Effects of partial tonsillectomy on the immune functions of children with obstructive sleep apnea-hypopnea syndrome at early stage

The purpose of this study was to investigate the changes in the humoral and cellular immunity of children with obstructive sleep apnea-hypopnea syndrome and hypertrophy of tonsils before and after plasma-mediated temperature-controlled radiofrequency ablation treatment. Fifty-seven children suffering from obstructive sleep apnea-hypopnea syndrome and with hypertrophy of tonsils were enrolled in this study. Thirty-seven children were grouped in the partial tonsillectomy group and 20, in the tonsillectomy group. The levels of CD3(+), CD4(+), CD8(+), and CD4(+)/CD8(+) were measured for cellular immunity, and the levels of IgG, IgA, and IgM were measured for humoral immunity. Blood samples were collected before and 1 and 3 months after the operation. The IgG, IgA, and IgM levels in the tonsillectomy group were significantly decreased 1 month after the operation, and recovered to the normal levels within 3 months of the operation (P < 0.05). However, the levels of IgG, IgA, and IgM in the partial tonsillectomy group decreased slightly, without a significant difference (P > 0.05). The cellular immunity of the 2 groups was not statistically different pre- and post-operation (P > 0.05). The results from the present study indicate that partial tonsillectomy by plasma-mediated temperature-controlled radiofrequency ablation did not impact on the humoral and cellular immunity of children.

Absence of the adenosine A2A receptor confers pulmonary arterial hypertension and increased pulmonary vascular remodeling in mice

BACKGROUND

Pulmonary arterial hypertension (PAH) is characterized by sustained elevation of pulmonary vascular resistance resulting from endothelial and smooth muscle cell dysfunction and collagen deposition in pulmonary vascular walls. In this study, we investigated the role of the adenosine A(2A) receptor (A(2A)R) in the development of PAH by determining the effect of genetic inactivation of A(2A)Rs on pulmonary vascular remodeling in mice.

METHODS AND RESULTS

We characterized hemodynamic, histological and ultrastructural changes in pulmonary vascular remodeling in A(2A)R knockout (KO) mice compared with their wild-type (WT) littermates after exposure to normoxia and hypoxic conditions. After exposure to normoxia, compared to WT mice, A(2A)R KO mice displayed: (1) increased right ventricular systolic pressures and an elevated ratio of the right ventricle over left ventricle plus septum (Fulton index), (2) increased wall area and thickness as well as enhanced smooth muscle actin immunoreactivity in pulmonary resistance vessels, (3) increased proliferating cell nuclear antigen-positive cells in pulmonary resistance vessels and (4) increased smooth muscle cells hypertrophy and collagen deposition in the adventitia of pulmonary arteriole walls as revealed by electron microscope. By contrast, histological analysis revealed no features of hypertensive nephropathy in A(2A)R KO mice and there was no significant difference in systemic blood pressure, and left ventricular masses among the 3 genotypes. Furthermore, following chronic exposure to hypoxia, A(2A)R KO mice exhibited exacerbated elevation in right ventricular systolic pressure, hypertrophy of pulmonary resistance vessels and increased cell proliferation in pulmonary resistance vessels, compared to WT littermates. Thus, genetic inactivation of A(2A)Rs selectively produced PAH and associated increased smooth muscle proliferation and collagen deposition.

CONCLUSIONS

Extracellular adenosine acting at A(2A)Rs represents an important regulatory mechanism to control the development of PAH and pulmonary vascular remodeling.

Phytoextraction of Cd-contaminated soil by carambola (Averrhoa carambola) in field trials

Use of metal-accumulating woody species to extract metals from heavy metal contaminated soil has received more attention. While considerable studies have focused on the phytoextraction potential of willow (Salix spp.) and poplar (Populus spp.), similar information is rare for other woody species. Carambola (Averrhoa carambola) is a high-biomass tree and has been identified as a new Cd-accumulating species. The present study aimed to evaluate the Cd phytoextraction potential of carambola under field condition. After growing in a slightly Cd-contaminated site for about 170 d, the carambola stand initiated by seed-seedling with high planting density (encoded with "HD-1yr") attained a high shoot biomass yield of 18.6 t ha(-1) and extracted 213 g Cdha(-1), resulting in a 1.6-fold higher Cd removal efficiency than that of a contrasting stand established by grafted-seedling with low planting density (5.3% vs. 2%). That is, "HD-1yr" would remove 50% of the total soil Cd with 13yr, assuming that the Cd removal efficiency would not change over time. Further, one crop of "HD-1yr" significantly decreased (63-69%) the Cd uptake by subsequent vegetables. Among the four carambola stands established using grafted-seedling, the 2-yr-old stand exhibited the highest annual Cd removal efficiency (3.7%), which was yet lower than that of "HD-1yr". These results suggested that phytoextraction of Cd by carambola (especially for "HD-1yr" stand) presented a feasible option to clean up agricultural soils slightly contaminated by Cd.

[Determination of tetrandrine in human plasma by high-performance liquid chromatography]

The paper reports the determination of tetrandrine by high performance liquid chromatography (HPLC). A C18 column was used and the mobile phase was methanol-water(80:20) containing 0.03% triethylamine, detective wave was at 282 nm, the internal standard was diazepam, the sample was extracted with ether. The linear range was from 0.289 microgram.ml-1 to 4.618 micrograms.ml-1, the average recovery rate was 95.8%. The coefficients of variation of within-day and day-to-day were less than 5%. This method is simple, rapid and accurate. It can be used in biomedical sample analysis of tetrandrine.

[Fusion expression of cecropin X including the cleavage of FXa in Escherichia coli]

PCR method was used to introduce the code sequence of Factor Xa cleavage site to the 5' end of cecropin CMIV mutant gene X, then the gene was cloned into the expression vector pGEX-KG, and was highly expressed in E. coli BL21 by IPTG induction. The fusion protein was purified by affinity-chromatography and was cleaved by Factor Xa. Cecropin X with antibacterial activity was obtained after purified by ion-exchange chromatography.

[Studies on quantitative chromatographic retention-structure relationships]

Using quantum and molecular mechanics methods, 48 structural descriptors of alkylbenzene compounds such as atomic partial charge, dipole moment, molecular area, molecular volume etc. were calculated. GFA regression methods were applied to build a quantitative chromatographic retention-structure relationships equation. The equation have good fitness and strong predictivity. Principle structural factors that effect chromatographic retention of alkylbenzenes were discussed.

Light dependence of quantum yields of Photosystem II and CO2 fixation in C 3 and C 4 plants

The light dependence of quantum yields of Photosystem II (ΦII) and of CO2 fixation were determined in C3 and C4 plants under atmospheric conditions where photorespiration was minimal. Calculations were made of the apparent quantum yield for CO2 fixation by dividing the measured rate of photosynthesis by the absorbed light [A/I=ΦCO2 and of the true quantum yield by dividing the estimated true rate of photosynthesis by absorbed light [(A+Rl)/Ia=ΦCO2·], where RL is the rate of respiration in the light. The dependence of the ΦII/ΦCO2 and ΦII/ΦCO2 (*) ratios on light intensity was then evaluated. In both C3 and C4 plants there was little change in the ratio of ΦII/ΦCO2 at light intensities equivalent to 10-100% of full sunlight, whereas there was a dramatic increase in the ratio at lower light intensities. Changes in the ratio of ΦII/ΦCO2 can occur because respiratory losses are not accounted for, due to changes in the partitioning of energy between photosystems or changes in the relationship between PS II activity and CO2 fixation. The apparent decrease in efficiency of utilization of energy derived from PS II for CO2 fixation under low light intensity may be due to respiratory loss of CO2. Using dark respiration as an estimate of RL, the calculated ΦII/ΦCO2 (*) ratio was nearly constant from full sunlight down to approx 5% of full sunlight, which suggests a strong linkage between the true rate of CO2 fixation and PS II activity under varying light intensity. Measurements of photosynthesis rates and ΦII were made by illuminating upper versus lower leaf surfaces of representative C3 and C4 monocots and dicots. With the monocots, the rate of photosynthesis and the ratio of ΦII/ΦCO2 exhibited a very similar patterns with leaves illuminated from the adaxial versus the abaxial surface, which may be due to uniformity in anatomy and lack of differences in light acclimation between the two surfaces. With dicots, the abaxial surface had both lower rates of photosynthesis and lower ΦII values than the adaxial surface which may be due to differences in anatomy (spongy versus palisade mesophyll cells) and/or light acclimation between the two surfaces. However, in each species the response of ΦII/ΦCO2 to varying light intensity was similar between the two surfaces, indicating a comparable linkage between PS II activity and CO2 fixation.

The length of a junction between the B and Z conformations in DNA is three base pairs or less

Recently it has been suggested that double-helical complexes formed between the DNA sequences (CG)n(A)m and their conjugates, (T)m(CG)n, would be candidates for the formation of a B-Z junction in aqueous solution at high salt concentrations [Peticolas et al. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 2579-2583]. The junction was predicted to occur between a B-type helix in the d(A)m.d(T)m section and a Z-type helix in the self-complementary (CG)n.(CG)n sequence. In this paper we report Raman experiments on the deoxyoligonucleotides d(CGCGCGCGCGCGAAAAA) and d(CGCGCGAAAAA) and their complements. It is found the latter compound cannot be induced into the Z form in saturated salt solution but that the former sequence goes into a B-Z junction at 5.5 M salt. From a comparison of the relative intensity of the Raman conformational marker bands for B and Z DNA for both the A-T and C-G base pairs, it is shown that in 5.5 M NaCl solution none of the A-T base pairs are in the Z form, but nine of the C-G base pairs are in the Z form. The remaining three C-G base pairs are either in the junction or in the B form. Thus, the junction is formed from three or less C-G base pairs. If the solution is made 95 microM with NiCl2, then the entire duplex goes into the Z form and the Raman bands of the adenine are completely changed into those of the Z form.(ABSTRACT TRUNCATED AT 250 WORDS)

Points that merit consideration in the diagnosis of retinoblastoma

According to the clinical appearances and the characteristics of the onset of 86 Rb cases, some points in the diagnosis merit consideration: 1) Since the average symptomatic age was 21.75 months and the mean diagnostic age was 24.32 months, children under 3 years with leukocoria should be carefully examined, while adult Rb should not be neglected. 2) The primary symptom of Rb is mostly leukocoria, but Rb eyes without any symptoms or leukocoria (26 out of 105 eyes in our groups) might also be encountered. 3) 4 out of the 86 cases were retinocytoma which is supposed to be a type of Rb degeneration or benign Rb. 4) Attention should be paid to abnormalities and second primary tumors in Rb patients. 5) The pedigree investigations, twin method and laboratory studies in Rb such as chromosome analysis, EsD, LDH measurement and RFLP technique are useful in the prenatal diagnosis, early diagnosis and the diagnosis of the carriers.

Ocular survey of deaf-mute children

Through routine ocular examination of 279 Deaf-mute students in Lie De School in Guangzhou in 1988 by visual chart, Yu Zi Ping Pseudoisochromatic plate, portable slit lamp and direct ophthalmoscope, 100 persons (35.8%) were found to have ocular defects in one or both eyes. The incidence of ocular defects was higher than that of the normal populations. Among the ocular abnormalities, fundus defects occupied 28.6%, error of refraction, 17.9%. 17.9% of the eyes had the vision lower than 1.0 and the error of refraction was the main cause. Cases of hereditary syndromes were found: Usher syndrome, 2 cases; Goldenhar syndromes, 2 cases (brother and sister); Waardenburg syndrome, 1 case; von Recklinghausen's syndrome, 1 case. In comparing with the other articles, the ocular defect, visual disturbance, error of refraction, way of examination as well as types and characteristics of some syndromes were briefly discussed. The importance of special examinations for diagnosis, early correction of refractive error, avoidance of consanguineal marriage among deaf-mutes were emphasized.

Lymphocyte chromosome survey in 80 patients with retinoblastoma

Cytogenetic analysis of eight cases of retinoblastoma patients was carried out to determine the occurrence of chromosome aberrations and to identify consistently associated clinical abnormalities. Among the 80 cases, 55 cases were unilateral, 25 cases were bilateral, seventy patients had a positive family history of Rb in 10 families. Normal chromosomes were found in 70 patients. Ten patients showed abnormal karyotypes: two cases of 13q deletion, one case of mosaicism of 13q deletion, one case of translocation between chromosomes 13 and 15 with the interstitial deletion of 13q, one case of 47, xxy, three cases of pericentric inversion of heteromorphic region of chromosome 9, two cases of pericentric inversion of chromosome Y. The patient who had the translocation between 13 and 5 with 13q deletion was found to have the characteristic midfacial appearance associated with 13q-deletion syndrome.