[Association of CYP19A1 gene rs7176005 single nucleotide polymorphism with breast cancer risk and clinicopathologic features of tumor]

Objective: The aim of this study was to investigate the association of the CYP19A1 rs7176005 single nucleotide polymorphism (SNP) with breast cancer risk and with clinicopathologic features of tumors. Methods: This study was conducted by including 138 patients with breast cancer (cancer group), those who diagnosed as primary breast cancer after operation by pathology. There were 293 cases in the group of benign breast disease which was presented as a solid mass by the color ultrasound and pathologically diagnosed as "fibroadenoma or adenosis" (benign breast disease group), the cases were paired with breast cancer patients by age±5 in the same period, and there were 259 cases in the group of healthy control who received routine physical examination during the same period and were paired with breast cancer patients by age±5 without any detection of breast related diseases (healthy control group) at West China hospital between September 2012 and November 2016. The CYP19A1 rs7176005 SNP was detected by a direct sequencing method. Hardy-Weinberg test was used to analyze the genetic balance of the 3 groups. Chi square test was used to compare the distribution of rs7176005 genotypes between the 3 groups, and the differences of clinicopathological features in breast cancer patients carrying different genotypes. Results: The ages of the breast cancer cases, the benign breast disease group and the healthy control group were (44.69±8.09), (42.33±11.44) and (41.92±9.61) years old, respectively. Hardy-Weinberg equilibrium test identified that the composition ratios of alleles C and T in breast cancer group, benign breast disease group and healthy group were not statistically significant (χ(2) values were 0.83, 0.34 and 0.04, respectively, P values were 0.363, 0.561, and 0.852, respectively). All the three groups met the genetic balance, had consistency and could represent the population. Among the 138 cases of breast cancer, the CYP19A1 rs7176005 SNP was significantly associated with the diameter of the tumor (P=0.031). The majority of tumor size was <2 cm in patients who carrying TT and CT genotypes, and the proportion was 75% (12/16) and 58% (40/69), respectively. While those patients with TT genotype were mainly >2 cm and ≤5 cm, and the proportion was 51% (27/53). The distribution of TNM stage among patients with different genotypes was also statistically significant (χ(2)=11.19, P=0.025). The most common stage was Ⅱ in Patients who carrying CC and CT genotypes, and the proportion was 45.3% (24/53) and 52.2% (36/69), respectively. While those patients with TT genotype was mainly in stage Ⅰ and the proportion was 56.3% (9/16). Conclusion: Though the CYP19A1 rs7176005 SNP is not associated with breast cancer development, breast cancer patients with the C allele exhibit a high tumor growth rate and large diameters.

Intraocular delivery of recombinant virus

In the past 5 yr, advances in technology have been made that allow efficient somatic transfer of functional genes to target cells in the eye in vivo. The ability to deliver functional genes to these cells is due primarily to the development of viral vectors-viruses in which various replicative functions have been replaced with transgene cassettes. Because progress continues in developing new vectors and refining those that are already available, the field has moved past the step of actually proving that gene transfer is possible to one where vectors are used (experimentally) for therapeutic purposes. In fact, proofs of principle of virus-based retinal gene therapy have been achieved in relevant animal models for retinitis pigmentosa (1-3).

Long-term protection of retinal structure but not function using RAAV.CNTF in animal models of retinitis pigmentosa

The present study aimed to determine whether intravitreal administration of an adeno-associated virus (AAV) carrying ciliary neurotrophic factor (CNTF) can achieve long-term morphological and physiological rescue of photoreceptors in animal models of retinitis pigmentosa, and whether injection of this virus after degeneration begins is effective in protecting the remaining photoreceptors. We injected rAAV.CNTF.GFP intravitreally in early postnatal Prph2(Rd2/Rd2) (formerly rds/rds) mice and in adult P23H and S334ter rhodopsin transgenic rats. Contralateral eyes received an intravitreal injection of rAAV.GFP or a sham injection. We evaluated the eyes at 6 months (rats) and 8.5 to 9 months (mice) postinfection and looked for histological and electoretinographic (ERG) evidence of photoreceptor rescue and CNTF-GFP expression. Intravitreal administration of rAAV resulted in efficient transduction of retinal ganglion cells in the Prph2(Rd2/Rd2) retina, and ganglion, Muller, and horizontal/amacrine cells in the mutant rat retinas. Transgene expression localized to the retinal region closest to the injection site. We observed prominent morphological protection of photoreceptors in the eyes of all animals receiving rAAV.CNTF.GFP. We found the greatest protection in regions most distant from the CNTF-GFP-expressing cells. The Prph2(Rd2/Rd2) ERGs did not exhibit interocular differences. Eyes of the rat models administered rAAV.CNTF.GFP had lower ERG amplitudes than those receiving rAAV.GFP. The discordance of functional and structural results, especially in the rat models, points to the need for a greater understanding of the mechanism of action of CNTF before human application can be considered.

Melatonin delays photoreceptor degeneration in the rds/rds mouse

Photoreceptors in retinitis pigmentosa (RP), a group of inherited retinal degenerative diseases, die through apoptosis. Since melatonin protects against neuronal apoptotic death, we tested its ability to slow photoreceptor degeneration in the rds/rds mouse, an animal model for RP. Shortly after birth, rds/rds mice were given daily i.p. injections of melatonin or vehicle for 11 weeks. Melatonin treatment significantly delayed photoreceptor loss and reduced the number of apoptotic photoreceptors. Further studies should determine if melatonin will have potential for the treatment of certain human retinal degenerations.

AAV-mediated delivery of ciliary neurotrophic factor prolongs photoreceptor survival in the rhodopsin knockout mouse

Retinitis pigmentosa (RP), an inherited retinal degenerative disease causing blindness, is characterized by progressive apoptotic death of photoreceptors. Therapeutic modification of photoreceptor apoptosis may provide an effective therapy for this disorder. Ciliary neurotrophic factor (CNTF) has been shown to promote survival of a number of different neuronal cell types, including photoreceptors. The present study aimed to test whether adeno-associated virus (AAV)-mediated delivery of the gene encoding CNTF delays photoreceptor death in the rhodopsin knockout (opsin(-/-)) mouse, an animal model of RP. The vector was made to express a secretable form of CNTF in tandem with a marker GFP. Cultured 293 cells transduced with this virus expressed both CNTF and GFP. The conditioned media from such cells supported the survival of chick dorsal root ganglion neurons in the same manner as recombinant CNTF. Subretinal administration of this virus led to efficient transduction of photoreceptors as indicated by GFP fluorescence and CNTF immunostaining. Histologic examination showed significant photoreceptor preservation in the injected quadrant of the retina. This protection lasted through termination of the experiment (3 months). AAV-mediated delivery of CNTF may have implications for the treatment of human retinal degeneration.

Role of brain-derived neurotrophic factor in the circadian regulation of the suprachiasmatic pacemaker by light

The central pacemaker located in the suprachiasmatic nucleus (SCN) of the hypothalamus mediates the generation of mammalian circadian rhythms, including an oscillation in pacemaker sensitivity to photic signals conveyed by the retinohypothalamic tract. Because brain-derived neurotrophic factor (BDNF) has been implicated in the functional regulation of neural input to other targets of visual pathways, the present study examined whether changes in BDNF expression or blockade of its action in the SCN affect circadian pacemaker responses to light. In rats receiving infusion of exogenous BDNF into the SCN, the free-running rhythm of activity in constant darkness was characterized by large phase advances in response to light exposure during the midsubjective day, when the circadian pacemaker is normally insensitive to photic perturbation. In contrast, SCN infusion of BDNF did not potentiate either phase-delaying or phase-advancing effects of light on the rat activity rhythm during the subjective night. In heterozygous BDNF mutant mice, deficits and damped rhythmicity in SCN levels of this neurotrophin were accompanied by marked decreases in the amplitude of light-induced phase shifts during the subjective night. In agreement with the effects of decreased BDNF expression, SCN infusion of the tyrosine kinase inhibitor K252a blocked or strongly inhibited both the phase-delaying and -advancing effects of light during the subjective night. Collectively, these findings suggest that BDNF-mediated signaling may play an important role in the circadian regulation of SCN pacemaker sensitivity to light.

Establishment and characterization of adenoviral E1A immortalized cell lines derived from the rat suprachiasmatic nucleus

Primary cultured cells from the presumptive anlage of the rat suprachiasmatic nucleus (SCN) were immortalized by infection with a retroviral vector encoding the adenovirus 12S E1A gene. After drug selection, the resulting neural cell lines (SCN1.4 and SCN2.2) displayed (a) extended growth potential without evidence of transformed or tumorigenic properties, (b) expression of E1A protein within all cell nuclei, and (c) heterogeneous cell types in various stages of differentiation. A large proportion of the SCN1.4 and SCN2.2 cells were characterized by gliallike morphologies, but showed limited expression of corresponding cell type-specific antigens. In addition, both lines exhibited a stable population of cells with neuronlike characteristics. When treated so as to enhance differentiation, these cells were often distinguished by fine, long processes and immunocytochemical expression of neuronal markers and peptides found within SCN neurons in situ. Observations on SCN neuropeptide immunostaining, content, release, and mRNA expression followed a concordant pattern in which somatostatin and vasopressin cells were the most and least common peptidergic phenotypes in both lines, respectively. Since these results indicate that constituents of E1A-immortalized lines derived from the primordial SCN can differentiate into cells with phenotypes resembling parental peptidergic neurons, it will be critical to explore next whether these lines also retain the distinctive function of the SCN to generate circadian rhythms. Cloning of immortalized cell types could subsequently yield useful tools for studying the development of SCN glial and peptidergic cell types and delineating their distinct roles in mammalian circadian time-keeping.

Immortal time: circadian clock properties of rat suprachiasmatic cell lines

Cell lines derived from the rat suprachiasmatic nucleus (SCN) were screened for circadian clock properties distinctive of the SCN in situ. Immortalized SCN cells generated robust rhythms in uptake of the metabolic marker 2-deoxyglucose and in their content of neurotrophins. The phase relationship between these rhythms in vitro was identical to that exhibited by the SCN in vivo. Transplantation of SCN cell lines, but not mesencephalic or fibroblast lines, restored the circadian activity rhythm in arrhythmic, SCN-lesioned rats. Thus, distinctive oscillator, pacemaker, and clock properties of the SCN are not only retained but also maintained in an appropriate circadian phase relationship by immortalized SCN progenitors.

Expression of brain-derived neurotrophic factor and its cognate receptor, TrkB, in the rat suprachiasmatic nucleus

Photic entrainment of mammalian circadian rhythms occurs because the pacemaker in the suprachiasmatic nuclei (SCN) of the hypothalamus is endowed with a rhythmic sensitivity to photic signals conveyed by the retinohypothalamic tract. Since brain-derived neurotrophic factor (BDNF) has been implicated in the functional modulation of other retinal targets, the rat SCN was examined for expression and cellular distribution of this neurotrophin and TrkB, the tyrosine kinase receptor that preferentially binds BDNF. The rat SCN was found to express the mature BDNF peptide and mRNA by Western blotting, enzyme-linked immunosorbent assay (ELISA), and reverse transcription-polymerase chain reaction (RT-PCR) analyses. BDNF-immunoreactivity and hybridization signal for its mRNA were coextensively localized within a number of SCN cells throughout the rostrocaudal axis of each nucleus. In addition, some cells intercalated within the optic chiasm were distinguished by expression of BDNF immunoreactivity or mRNA. Immunostaining for the TrkB receptor was also evident in the SCN within terminals or fibers predominantly located along the SCN/optic chiasm interface and within scattered perikarya near the medial border of each nucleus. Combined in situ hybridization and immunocytochemical analysis revealed that BDNF mRNA-expressing cells within the ventrolateral SCN were often closely apposed to TrkB-positive fibers extending from the optic chiasm. These findings raise the possibility that target-derived interactions between BDNF and TrkB receptors could play a role in the circadian modulation of SCN pacemaker sensitivity to photic input transmitted by the retinohypothalamic tract.

Circadian rhythm of brain-derived neurotrophic factor in the rat suprachiasmatic nucleus

This study was conducted to determine whether the rat suprachiasmatic nucleus (SCN) is characterized by circadian expression of brain-derived neurotrophic factor (BDNF). In constant darkness, SCN content of both BDNF mRNA and protein oscillated in a circadian fashion. BDNF mRNA and protein levels in the SCN reached peak values during the early subjective day and during the subjective night, respectively. In contrast, the hippocampus showed no sign of circadian rhythmicity in its expression of BDNF mRNA and protein. Since BDNF enhances synaptic transmission in other brain regions, the coincidence between peak expression of BDNF protein in the SCN and the known interval of circadian pacemaker sensitivity to the phase-shifting effects of light may have some implications for the role of BDNF in the circadian regulation of the SCN pacemaker by photic signals from the retinohypothalamic tract.

Effect of saponins of Panax notoginseng on synaptosomal 45Ca uptake

AIM

To explore the calcium uptake antagonism of saponins of Panax notoginseng (PNS).

METHODS

Synaptosomes were prepared from rat cerebral cortex by using differential Ficoll gradients. The effects of PNS on synaptosomal 45Ca uptake were measured in vitro or after acute treatment.

RESULTS

PNS 50-800 mg.L-1 produced a concentration-rated inhibition of Ca2+ uptake [IC50 = 111 (46-176) mg.L-1]. Both initial and maximal uptake were inhibited. Similar effect was obtained after acute PNS treatment with 200 mg.kg-1 i.p. The blocking effect of PNS was reversed by calcium in media.

CONCLUSION

PNS is a calcium channel blocker in neurons.

Corneal sensitivity and nerve regeneration after excimer laser ablation

We studied the recovery of corneal sensitivity and corneal regeneration after excimer laser and manual epithelial debridement. The corneal epithelia of right eyes of New Zealand white rabbits (n = 21) were manually debrided and the corneal epithelia of the left eyes were ablated with the excimer laser (47 mm depth, 5 Hz, and 160 mJ/cm2). The relative density of innervation on the intraepithelial layer was measured using gold chloride staining and light microscopy. Wound healing and corneal sensitivity also were observed. Laser-ablated corneal sensitivity increased rapidly to a normal level by day 5, then increased gradually and reached a maximum at day 42. It remained elevated until 126 days, then returned to normal at 210 days. There were significant differences in the recovery of sensitivity after excimer ablation and manual epithelial removal. At day 35, relative density of innervation in the intraepithelial layer treated with excimer laser ablation was significantly higher than that treated with manual debridement. We observed a correlation between increased sensitivity and increased nerve density after excimer ablation. Compared with manual debridement, laser treatment resulted in an increase in networks of axons with terminal endings. This may not be the only factor correlating directly with hypersensitivity after corneal debridement, but it may indicate a quicker recovery route by using a presurgical manual debridement technique.

Surface quality of excimer laser corneal ablation with different frequencies

To test the effects of different frequencies of a 193-nm excimer laser on the surface smoothness of the ablated materials and the damage to the adjacent structure, four different frequencies (5, 10, 15, and 20 Hz) of a 193-nm excimer laser were used to perform ablations on 20 rabbit corneas and four polymethylmethacrylate blocks at a fluence of 160 mJ/cm2. Each frequency was tested five times on five corneas. The ablated materials were processed and examined with scanning electron microscopy (SEM) and light and transmission electron microscopy (TEM) and a Zygo interference microscope, which quantitatively evaluates the surface smoothness. The results from the Zygo microscope show that there is no statistically significant difference in surface smoothness between any two different frequencies. The SEM reveals similar regularity and uniformity on the ablated surfaces, with no relationship between the laser frequencies and the amount of surface deposits. The TEM demonstrates no correlation between the various frequencies and the thickness of the superficial pseudomembrane and the amount of collateral damage in the adjacent stroma. It appears that the higher frequencies are comparable to the lower one (5 Hz) as to ablation quality, with the benefit of curtailing surgical time and decreasing the chances of eye movement.

[Primary leiomyosarcoma of the inferior vena cava--a report of 4 cases]

Primary leiomyosarcoma of the inferior vena cava (IVC) is of rare occurrence. From 1988 to 1992, 4 cases, all female, were treated in our hospital. Symptoms of this rare tumor were not typical except pain in the abdomen and the back. But it was painless in one patient. Diagnosis was solely dependent on imaging with regard to tumor localization, size and extent of invasion to adjacent organs. The best treatment of choice was excision of the tumor with the IVC affected. Tumor located in the middle and lower third of IVC usually involving the right renal vein. Therefore, it was necessary to remove the right kidney, when provided the left kidney was functionally normal. One patient died postoperatively of pulmonary embolism and the other died of hepatic failure due to multiple metastases in the liver.

A new procedure for evaluating smoothness of corneal surface following 193-nanometer excimer laser ablation

BACKGROUND

The routine technique for evaluating the smoothness of an excimer laser keratectomy has been scanning electron microscopy (SEM). However, this method suffers from tissue shrinkage and surface artifacts, and evaluates the surface only in a qualitative manner. In our study, we used a Zygo microscope to quantitatively assess the smoothness of the excimer laser ablated corneas, without complicated tissue processing.

METHODS

Five rabbit eyes and five PMMA blocks underwent 193-nanometer excimer laser ablations (5.00-millimeter diameter and 80-micrometer depth). The ablation zones of the corneas were trephined and fixated prior to the measurement. The surface smoothness was measured under the Zygo and characterized by two surface parameters (Ra and RMS). After measurement, the corneal and PMMA samples were processed for SEM.

RESULTS

The Ra and RMS (mean +/- SD) for the ablated corneas are 183.33 +/- 20.6 and 240.06 +/- 23.10 nm, respectively; for the PMMA blocks, 79.49 +/- 23.02 and 96.45 +/- 27.16 nm, respectively. There are significant differences of Ra and RMS between the ablated corneas and PMMA blocks (p < .01), indicating the ablated corneal surfaces are rougher than the ablated PMMA surfaces. Qualitatively, SEM correlated well with the results of the Zygo measurements.

CONCLUSIONS

We found this technique to be a simple, accurate, and reproducible means of objectively assessing the surface smoothness following excimer laser ablation. Combined use of the Zygo and SEM enables more complete evaluation of the ablated corneal surface.

Hypersensitivity following excimer laser ablation through the corneal epithelium

BACKGROUND

From our preliminary study, we found corneal hypersensitivity after excimer laser. To study the effects of corneal epithelial wound healing on corneal sensitivity, we investigated the recovery of corneal sensitivity following excimer laser and manual epithelial debridement.

METHODS

The corneal epithelium of the right eye of New Zealand white rabbits (n = 19) was manually debrided and the left eye was ablated with the excimer laser (5 Hz, 160 mJ/cm2, 47-micrometer depth). The wound-healing rate was measured up to 46 hours. Corneal sensitivity was measured for 10 weeks.

RESULTS

There was no significant difference in the wound-healing rate, but at 36 hours there was a reduction in wound-healing rate of the excimer ablated corneas. In the laser-ablated cornea, sensitivity rapidly increased to a normal level by day 5, and then it continued to increase gradually and reached a maximum at day 42. Thereafter, it retained a higher level than normal up to 10 weeks. There were significant differences in the recovery of sensitivity following excimer ablation and manual debridement.

CONCLUSIONS

These results show the development of a lasting enhanced sensitivity in the cornea after excimer laser ablation, suggesting the need to conduct further studies of neural plasticity and sensory thresholds following interventions on the corneal surface.

Noncross-linked collagen discs and cross-linked collagen shields in the delivery of gentamicin to rabbits eyes

Using fluorescent polarization immunoassay, in vitro absorption and elution of gentamicin by noncross-linked collagen discs was measured. This technique was compared with that of cross-linked collagen shields and topical drops to provide adequate gentamicin levels in the cornea and aqueous humor of the rabbit eye. In vitro results showed that the noncross-linked collagen discs absorbed increased gentamicin with prolonged soaking time. All 2-hr presoaked discs completely dissolved within 6 min after being placed in the lower fornix of the rabbit eye. The presoaked discs released most of their gentamicin load within 0.5 hr of elution. Gentamicin levels in the cornea and aqueous humor, using 2-hr presoaked discs, were similar to those obtained with a single drop (P greater than 0.05) of topical solution and significantly lower than those obtained by applying a collagen shield at all intervals (P less than 0.01) and by hourly drops measured at 4- and 6-hr intervals (P less than 0.01). These results suggest that, in their current formulation, the presoaked collagen discs may not be an effective alternative to collagen shields or topical drops for gentamicin delivery because of their rapid dissolution in the eye.