Aggregation-Induced Emission-Based Macrophage-Like Nanoparticles for Targeted Photothermal Therapy and Virus Transmission Blockage in Monkeypox

The recent prevalence of monkeypox has led to the declaration of a Public Health Emergency of International Concern. Monkeypox lesions are typically ulcers or pustules (containing high titers of replication-competent virus) in the skin and mucous membranes, which allow monkeypox virus to transmit predominantly through intimate contact. Currently, effective clinical treatments for monkeypox are lacking, and strategies for blocking virus transmission are fraught with drawbacks. Herein, this work constructs a biomimetic nanotemplate (termed TBD@M NPs) with macrophage membranes as the coat and polymeric nanoparticles loading a versatile aggregation-induced emission featured photothermal molecule TPE-BT-DPTQ as the core. In a surrogate mouse model of monkeypox (vaccinia-virus-infected tail scarification model), intravenously injected TBD@M NPs show precise tracking and near-infrared region II fluorescence imaging of the lesions. Upon 808 nm laser irradiation, the virus is eliminated by the photothermal effect and the infected wound heals rapidly. More importantly, the inoculation of treated lesion tissue suspensions does not trigger tail infection or inflammatory activation in healthy mice, indicating successful blockage of virus transmission. This study demonstrates for the first time monkeypox theranostics using nanomedicine, and may bring a new insight into the development of a viable strategy for monkeypox management in clinical trials.

Yes-associated protein nuclear translocation promotes anabolic activity in human articular chondrocytes

OBJECTIVE

Yes-associated protein (YAP) has been widely studied as a mechanotransducer in many cell types, but its function in cartilage is controversial. The aim of this study was to identify the effect of YAP phosphorylation and nuclear translocation on the chondrocyte response to stimuli relevant to osteoarthritis (OA).

DESIGN

Cultured normal human articular chondrocytes from 81 donors were treated with increased osmolarity media as an in vitro model of mechanical stimulation, fibronectin fragments (FN-f) or IL-1β as catabolic stimuli, and IGF-1 as an anabolic stimulus. YAP function was assessed with gene knockdown and inhibition by verteporfin. Nuclear translocation of YAP and its transcriptional co-activator TAZ and site-specific YAP phosphorylation were determined by immunoblotting. Immunohistochemistry and immunofluorescence to detect YAP were performed on normal and OA human cartilage with different degrees of damage.

RESULTS

Chondrocyte YAP/TAZ nuclear translocation increased under physiological osmolarity (400 mOsm) and IGF-1 stimulation, which was associated with YAP phosphorylation at Ser128. In contrast, catabolic stimulation decreased the levels of nuclear YAP/TAZ through YAP phosphorylation at Ser127. Following YAP inhibition, anabolic gene expression and transcriptional activity decreased. Additionally, YAP knockdown reduced proteoglycan staining and levels of type II collagen. Total YAP immunostaining was greater in OA cartilage, but YAP was sequestered in the cytosol in cartilage areas with more severe damage.

CONCLUSIONS

YAP chondrocyte nuclear translocation is regulated by differential phosphorylation in response to anabolic and catabolic stimuli. Decreased nuclear YAP in OA chondrocytes may contribute to reduced anabolic activity and promotion of further cartilage loss.

Acute embolic stroke with large-vessel occlusion: does contact aspiration thrombectomy show superiority?

AIM

To compare the efficacy between contact aspiration thrombectomy and stent retriever thrombectomy in the treatment of acute embolic stroke patients with large vessel occlusion.

MATERIALS AND METHODS

Between January 2019 and June 2020, data from consecutive acute ischaemic stroke patients who underwent either endovascular contact aspiration or stent retriever thrombectomy were analysed at one institution. The primary outcome was the full 90-day modified Rankin Scale (mRS) score. Ordinal logistic regression analysis was used to assess the association between thrombectomy approach and functional outcomes.

RESULTS

A total of 156 patients were analysed. Among them, 57 (36.5%) patients underwent primary aspiration thrombectomy, while 99 (63.5%) patients underwent primary stent retriever thrombectomy. The median procedure time was significantly shorter in patients treated with aspiration (37 versus 56 minutes; p<0.001). Compared with those of patients who underwent stent retriever thrombectomy, successful recanalisation rates and favourable functional outcome rates were higher in patients who underwent the aspiration approach (94.7% versus 77.8%, p=0.006; 49.1% versus 27.3%, p=0.006, respectively). Ordinal logistic regression analysis showed that aspiration thrombectomy was independently associated with a good functional outcome (adjusted common odds ratio, 0.30, 95% confidence interval: 0.16-0.60, p<0.001).

CONCLUSION

Among the specific patients with large vessel occlusion in acute embolic stroke, the use of aspiration thrombectomy compared with stent retriever thrombectomy resulted in a greater likelihood of favourable neurological outcomes; however, because of study limitations, these findings should be interpreted as preliminary and require further study to confirm these results.

Non-negligible clinical relevance of haemorrhagic transformation after endovascular thrombectomy with successful reperfusion in acute ischaemic stroke

AIM

To explore the association between haemorrhagic transformation (HT) subtypes and functional outcome in acute ischaemic stroke (AIS) patients with successful recanalization treated by endovascular thrombectomy (EVT).

MATERIALS AND METHODS

Consecutive patients with AIS due to large-vessel occlusion in the anterior circulation, who were treated between January 2015 and June 2019 and achieved successful EVT, were enrolled in this retrospective study. HT was categorized according to the Heidelberg Bleeding Classification. Functional outcome was evaluated using the 90-day modified Rankin Scale (mRS) after stroke onset. Ordinal logistic regression analysis was performed to determine the association of HT subtypes with functional outcomes.

RESULTS

A total of 243 patients were included for further analysis. Among them, 121 (49.8%) had HT. Ten (4.1%) patients were classified as haemorrhagic infarction (HI) subtype 1, 61 (25.1%) as HI subtype 2, 17 (7.0%) as parenchymal haematoma (PH) subtype 1, and 33 (13.6%) as PH subtype 2. Ordinal logistic regression analysis suggested that HI subtype 2 (adjusted common OR 0.357, 95% CI: 0.192-0.667), PH1 (adjusted common OR 0.254, 95% CI: 0.093-0.696) and PH subtype 2 (adjusted common OR 0.017, 95% CI: 0.006-0.051) were significantly associated with poor functional outcomes.

CONCLUSION

The present study shows that HI subtype 2, PH subtype 1, and PH subtype 2 are independently associated with poor clinical outcomes in AIS patients with successful recanalization after EVT.

Ventral hernia repair with synthetic mesh in a contaminated field: a systematic review and meta-analysis

PURPOSE

The use of mesh in ventral hernia repair becomes especially challenging when associated with a contaminated field. Permanent synthetic mesh use in this setting is currently debated and this discussion is yet to be resolved clinically or in the literature. We aim to systematically assess postoperative outcomes of non-absorbable synthetic mesh (NASM) used in ventral hernia repair in the setting of contamination.

METHODS

A literature search of PubMed, Embase, Scopus, Cinahl, and Cochrane Library identified all articles from 2000-2020 that examined the use of NASM for ventral hernia repair in a contaminated field. Postoperative outcomes were assessed by means of pooled analysis and meta-analysis. Qualitative analysis was completed for all included studies using a modified Newcastle-Ottawa scale.

RESULTS

Of 630 distinct publications and 104 requiring full review, this study included 17 articles published between 2007 and 2020. Meta-analysis demonstrated absorbable mesh was associated with more HR (OR 1.89, 1.15-3.12, p = 0.008), SSO (OR 1.43, 0.96-2.11, p = 0.087), SSI (OR 2.84, 1.85-4.35, p < 0.001), and unplanned reoperation (OR 1.99, 1.19-3.32, p = 0.009) compared to NASM.

CONCLUSION

The use of NASM for ventral hernia repair in a contaminated field may be a safe alternative to absorbable mesh, as evidenced by lower rates of postoperative complications. This review counters the current clinical paradigm, and additional prospective randomized controlled trials are warranted.

All-optical multilevel amplitude regeneration in a single nonlinear optical loop mirror

We experimentally demonstrate all-optical amplitude regeneration of 4-level pulse amplitude modulated signals (PAM4) based on a single nonlinear optical loop mirror (NOLM). Four power-plateau regions are achieved using return-to-zero (RZ) pulses of narrow pulse-width, enabling large nonlinear phase shifts within the highly nonlinear fiber (HNLF). We quantify noise suppression characteristics at each amplitude level and obtain an overall EVM improvement of 0.92dB by optimizing input power and distortion strength. A theoretical analysis has been also carried out matching the experimental results and revealing the design characteristics of the regenerator's nonlinear transfer function.

Systematic review with meta-analysis: combination treatment of regimens based on pegylated interferon for chronic hepatitis B focusing on hepatitis B surface antigen clearance

BACKGROUND

The seroclearance of hepatitis B surface antigen (HBsAg) in patients with chronic hepatitis B (CHB) is considered to be associated with favourable clinical outcomes.

AIMS

This meta-analysis was performed to establish the proportion of HBsAg loss rates among CHB patients who received combination treatment based on pegylated interferon (PegIFN). Four combination strategies have been studied with the aim of improving HBsAg loss: "de novo," "NA-experienced," "switch-to" and "add-on." This meta-analysis was performed to determine which, if any, of these combination strategies was more effective.

METHODS

Medline, Web of Science and Embase databases were searched from inception to December 2017. The proportion of patients who achieved HBsAg loss after combination therapy was pooled using a random-effects model.

RESULTS

Twenty-four studies fulfilled the meta-analysis criteria. The overall pooled proportion suggested that the rate of HBsAg loss could be increased to 9% (95% CI: 7%-12%) based on the combination treatment in CHB patients. Compared with "de novo" strategy (8%, 95% CI: 6%-10%), the "nucleos(t)ide analogues-experienced" (11%, 95% CI: 8%-15%) was found to be more likely (P = 0.036) to achieve a response. Compared with the "add-on" strategy (8%, 95% CI: 5%-13%), the "switch-to" (14%, 95% CI: 9%-20%) was found to be more likely (P = 0.012) to achieve HBsAg loss.

CONCLUSION

The "nucleos(t)ide analogues-experienced" strategy was more effective than the "De novo" strategy in achieving HBsAg loss for CHB patients. Combination treatment using regimens based on Peg-IFN may be useful to help nucleos(t)ide analogues-treated patients, who have experienced at least 48 weeks of nucleot(s)ide analogue, achieve HBsAg seroclearance.

Robust and tunable 16.375Gb/s dual-band optical OFDM transmissions over directly modulated VCSEL-based 200m OM2 MMFs

Utilizing low-cost, 2.2GHz modulation bandwidth, uncooled and standalone directly modulated VCSEL (DM-VCSEL)-based real-time dual-band optical OFDM (OOFDM) transmitters, aggregated 16.375Gb/s transmissions of OOFDM signals having bandwidths approximately 3.8 times higher than the VCSEL manufacturer-specified modulation bandwidths, are experimentally demonstrated, for the first time, over 200m OM2 MMF links based on intensity modulation and direct detection. The aggregated signal transmission capacities of the aforementioned links vary by just 8% for various OM2 MMFs ranging from 100m to 500m, and by just 10% over a 1GHz passband carrier frequency detuning range. Such dual-band OOFDM adaptability-induced excellent performance robustness and large passband frequency tunability can significantly relax the requirements on VCSEL modulation bandwidth for achieving specific transmission performances for cost-sensitive application scenarios such as data centers.

Self-seeding-based 10Gb/s over 25km optical OFDM transmissions utilizing face-to-face dual-RSOAs at gain saturation

Self-seeded passive optical networks (PONs) are currently attracting extensive research interest. In this paper, a novel self-seeded PON transmitter is, for the first time, proposed and experimentally demonstrated, which incorporates two face-to-face-positioned reflective semiconductor optical amplifiers (RSOAs) operating at their gain saturation regions: one RSOA directly driven by an upstream electrical signal and the other RSOA biased at a fixed current. Detailed experimental explorations are undertaken of the dynamic performance characteristics of the proposed transmitter. It is shown that, in comparison with previously reported self-seeded transmitters each employing a reflective mirror and a single electrical signal-driven RSOA, the proposed transmitter has a number of salient advantages including, considerably narrowed optical signal spectra, up to 16dB reduction in RINs of intensity-modulated optical signals, and residual intensity modulation crosstalk suppression as high as 10.7dB. The aforementioned features enable experimental demonstrations of real-time self-seeded 10Gb/s optical OFDM (OOFDM) transmitters. In particular, by making use of two low-cost RSOAs having their 3-dB modulation bandwidths as small as 1.125GHz, 10Gb/s over 25km adaptive OOFDM transmissions with power penalties of 0.6dB are experimentally achieved in the simple self-seeded IMDD PON systems.

The phrenic motor nucleus in the adult mouse

The present study was performed to establish an anatomical context for studies of phrenic motor function in mouse models of central nervous system trauma and disease. Application of cholera toxin β-subunit to the diaphragm of adult C57BL/6 mice revealed a columnar organization of phrenic motoneurons (PhMNs) which extended from rostral C3 to C6. Injection of Miniruby into the ventrolateral medulla revealed decussating, anterogradely labeled axons in the cervical spinal cord. In addition, application of the transneuronal tracer pseudorabies virus (PRV) to the right hemidiaphragm demonstrated a population of putative pre-phrenic interneurons at the level of the infected PhMN pool. These neuroanatomical features of the mouse phrenic nucleus are consistent with those described in other species and provide a foundation for studies of neuroplasticity and repair in relation to a functionally and anatomically identified spinal network.

Predictors of atypical birefringence pattern in scanning laser polarimetry

AIM

To evaluate predictors of atypical birefringence patterns (ABP) observed in scanning laser polarimetry.

METHODS

A total of 179 eyes from 82 normal subjects and 97 glaucoma patients were included. The retinal nerve fibre layer in each eye was imaged sequentially with GDx variable corneal compensation (VCC) and GDx enhanced corneal compensation (ECC) (Carl Zeiss Meditec, Dublin, California). The associations between the typical scan score (TSS) and age, axial length, spherical error, parapapillary atrophy (PPA) and visual-field mean deviation (MD) were evaluated with univariate and multivariate regression analyses.

RESULTS

23.5% (42/179) and 5.0% (9/179) of subjects had ABP (TSS<80) with GDx VCC and GDx ECC, respectively. For both GDx VCC and ECC, the TSS was significantly correlated with age, axial length, spherical error and PPA, but not with visual-field MD. After adjusting the effect of covariates, the axial length/spherical error and PPA were significantly associated with GDx VCC TSS, whereas the axial length/spherical error was the only predictor for GDx ECC TSS. Myopic eyes were more likely to develop ABP in both GDx VCC and ECC.

CONCLUSIONS

Axial length or spherical error is a significant predictor for ABP with both GDx VCC and GDx ECC. Caution should be exercised in interpreting the results of scanning laser polarimetry in eyes with a long axial length or myopia.

Biodegradable porous calcium polyphosphate scaffolds for the three-dimensional culture of dental pulp cells

AIM

To develop a three-dimensional culture model of human dental pulp cells (DPCs) with biodegradable porous calcium polyphosphate (CPP) scaffolds.

METHODOLOGY

Human DPCs were isolated from three donors. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate the cytotoxicity of CPP compared with hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP). Values were analysed using unpaired t-tests. Cells were seeded onto porous CPP scaffolds with pore sizes in the range of 200-300 microm. The nature of cellular adaptation in the three-dimensional culture model was then evaluated visually by scanning electronic microscopy (SEM) and confocal laser scanning microscopy (CLSM). The apoptotic property of cells on the scaffolds was also assessed by DNA staining with CLSM.

RESULTS

The cytotoxicity assay indicated that there was no significant difference between CPP and HA for each donor's original cells (P>0.05). Calcium polyphosphate had no cytotoxic effect on DPCs, whilst SEMs showed that cells successfully adhered to CPP scaffolds and spread amongst pores. On the cell surface, fine processes and matrix secretory granules were found. Confocal laser scanning microscopy showed that cells took on a three-dimensional structure with signs of vitality.

CONCLUSION

Porous CPP scaffolds are promising for the establishment of a three-dimensional culture model of DPCs.

[Experimental and mechanism analyses on HCl emission control during PVC combustion in fixed beds]

Incineration of chloridated plastic (PVC) in solid wastes contributes much to HCl pollutant in air environment. The characteristics of HCl emissions and reduction during PVC combustion were conducted in a nearly isothermal, externally heated, horizontal quartz-tube reactor. With increasing temperature from 700 to 900 degrees C, the conversion of HCl increased leniently from 82.5% to 88.3%. High excess air factor enhanced a small amount of HCl existing in form of Cl2. The calcium-based sorbents including CaCO3, Ca(OH)2, Ca(CH3COO)2 exhibited high HCl capture efficiencies from 68% to 79%, while magnesium-based sorbent less than that of 3%. Influences of operational variables, i.e., size of sorbent, Ca/Cl molar ratio and combustion fume compositions, on the HCl reduction were discussed. From a point of view of equilibrium constant of dechloridization reaction the experimental results were explained in detail.

[Phacoemulsification in white cataract]

OBJECTIVE

To evaluate the value and technique of Phacoemulsification in white cataract.

METHODS

Ninty eyes of senile cataract were divided into two groups by the density of the nuclei. Different operative technique was done in two groups.

RESULTS

The success rate of the continuous curvilinear capsulorhexis was 88.9%. Seventy five eyes have got the visual acuity over 0.5 on the first day after the operation. There was significant difference between two groups. The complications of operation were mild corneal edema and posterior capsule tear.

CONCLUSIONS

It's difficult to complete the phacoemulsification of white cataract. The surgeons are required the skillful technique and experience. However, phacoemulsification is valuable in white cataract.

Plasmacytoma of the gastrointestinal tract in Korea: higher incidence than in Japan and Epstein-Barr virus association

As a result of a systematic review of non-Hodgkin's lymphoma of the gastrointestinal tract (GI) at the Yonsei University, Seoul, Korea and the Osaka University, Osaka, Japan, we found an extramedullary plasmacytoma in 5 of a total of 78 cases (6.4%) in Korea and 1 of 136 cases (0.7%) in Osaka, which represents an approximately 9-fold difference in frequency. The presence of the Epstein-Barr virus (EBV) genome was examined in paraffin-embedded specimens from the 5 cases with GI plasmacytoma from Korea together with 17 patients collected by a nationwide study in Japan. There were no clinical findings suggestive of the presence of immunodeficiency in these Korean and Japanese patients. There were no prominent differences in the age distribution or sex ratio between the patients of the two countries. Histologically, the proliferation of mature plasma cells was almost monomorphous with occasional bi- or multinucleated forms. The immunohistochemistry revealed a restricted cytoplasmic expression of immunoglobulin light chain, kappa type in 8 cases and lambda type in 14. A polymerase chain reaction of preserved DNA from 4 Korean and 16 Japanese patients found that only 2, both Korean, were positive for EBV of subtype A. The difference in the frequency of EBV positivity between Korean and Japanese cases was significant (p < 0.05). In situ hybridization revealed positive signals in the nucleus of the tumor cells. IHC revealed that the tumor cells in these two cases were positive for latent membrane protein-1 and EB nuclear antigen-2, showing latent infection of EBV. These findings suggest a close association of EBV and Korean GI plasmacytoma, and might partly explain the remarkable number of cases in this country.

Epstein-Barr virus in gastric carcinoma in Suzhou, China and Osaka, Japan: association with clinico-pathologic factors and HLA-subtype

Information on geographic differences of Epstein-Barr virus (EBV) positivity and association with HLA in gastric carcinoma are limited. Therefore, the association of gastric carcinoma with EBV was examined in 118 patients from Suzhou, China, where the incidence of nasopharyngeal carcinoma (NPC) is high, and in 216 patients from Osaka, Japan, where the incidence of NPC is low, NPC being one of the EBV-associated carcinomas. Expression of HLA-A2 was also examined in some of these cases. The EBV genome was evidenced by PCR and in the tumor cells by in situ hybridization in 7/90 and 9/151 of cases from Suzhou and Osaka, respectively. Immunohistochemistry revealed that cancer cells in all cases with EBV did not express latent membrane protein-I. Type A was found in all cases positive for EBV. Among several histologic and clinical factors, only age of patients showed a correlation with EBV positivity: patients over 60 showed a higher frequency than patients below 60 years of age (p < 0.05). Typing of the HLA-A locus was possible in 16 cases positive for the EBV genome: 3 of 4 cases from Suzhou and 4 of 7 from Osaka were positive for HLA-A2 products. Severe lymphoid cell infiltration was found in 2 of 7 cases and 1 of 4 cases with and without the HLA-A2 type, respectively. The reported frequency of EBV positivity in Chinese living in Taiwan and in Japanese living in Hawaii is higher than in Suzhou, China, and Osaka, Japan, respectively. Our findings suggest that EBV association with gastric carcinoma is influenced by environmental and cultural factors.

Epstein-Barr virus in gastric carcinoma in Suzhou, China and Osaka, Japan: association with clinico-pathologic factors and HLA-subtype

Information on geographic differences of Epstein-Barr virus (EBV) positivity and association with HLA in gastric carcinoma are limited. Therefore, the association of gastric carcinoma with EBV was examined in 118 patients from Suzhou, China, where the incidence of nasopharyngeal carcinoma (NPC) is high, and in 216 patients from Osaka, Japan, where the incidence of NPC is low, NPC being one of the EBV-associated carcinomas. Expression of HLA-A2 was also examined in some of these cases. The EBV genome was evidenced by PCR and in the tumor cells by in situ hybridization in 7/90 and 9/151 of cases from Suzhou and Osaka, respectively. Immunohistochemistry revealed that cancer cells in all cases with EBV did not express latent membrane protein-I. Type A was found in all cases positive for EBV. Among several histologic and clinical factors, only age of patients showed a correlation with EBV positivity: patients over 60 showed a higher frequency than patients below 60 years of age (p < 0.05). Typing of the HLA-A locus was possible in 16 cases positive for the EBV genome: 3 of 4 cases from Suzhou and 4 of 7 from Osaka were positive for HLA-A2 products. Severe lymphoid cell infiltration was found in 2 of 7 cases and 1 of 4 cases with and without the HLA-A2 type, respectively. The reported frequency of EBV positivity in Chinese living in Taiwan and in Japanese living in Hawaii is higher than in Suzhou, China, and Osaka, Japan, respectively. Our findings suggest that EBV association with gastric carcinoma is influenced by environmental and cultural factors.

Epstein-Barr virus in lymphoproliferative diseases in the sino-nasal region: close association with CD56+ immunophenotype and polymorphic-reticulosis morphology

Association between Epstein-Barr virus (EBV) and nasal T-cell lymphoma (NTL) has been demonstrated. NTL has 2 types of histologic figures: one is ordinary non-Hodgkin's lymphoma (NHL) with monomorphous proliferation, and the other is polymorphic-reticulosis (PR) morphology. The presence of the EBV genome and its sub-types (A and B) were examined on paraffin-embedded specimens from 36 cases of sino-nasal lymphomas (SNL) collected from Seoul, Republic of Korea, where the frequency of NTL is high. Patients' ages ranged from 2 to 74 years (median 54 years) with a male-to-female ratio of 2.5:1. Immunophenotypically, 8 cases were B-cell type, 11 were T-cell type with CD56-, 14 were CD56+ type, and 3 were null-cell type. Five of 11 cases with ordinary NHL of T-cell type and 9 of 14 cases with PR were CD56+. The EBV genome was found by polymerase chain reaction (PCR) and in the tumor cells by in situ hybridization (ISH) in 1 of 4 B-cell type (25%), 5 of 10 T-cell type (50%), 11 of 13 CD56+ type (85%), and in both of null-cell type (100%). Of 16 cases with PR morphology, 15 (94%) were positive for the EBV genome. All of the 5 NTLs of ordinary NHL with CD56- were negative for EBV. Concerning the sub-type of EBV, 16 cases had type A, while none had type-B EBV. These findings suggest that NTL comprises 2 groups: EBV-positive NTLs are CD56+ and/or histologically PR, and EBV-negative NTLs are CD56- and histologically ordinary NHL. The current results on Korean patients, together with earlier studies on Japanese and Malaysian patients, have shown the predominance of type-A EBV in sino-nasal lymphoma in Asia.

Local projections of GABAergic neurons in the dentate gyrus and CA1 region in the rat hippocampal formation

Using retrograde transport of wheat germ agglutinin conjugated colloidal gold (WGA-gold) combined with immunoreactivity for glutamate decarboxylase (GAD), a specific synthesizing enzyme for gamma-aminobutyric acid (GABA), local projections of GABAergic neurons in the dentate gyrus and CA1 were examined. In the hilus of the dentate gyrus, it was found that GABAergic neurons in the granule cell layer projected to the ipsilateral upper leaf of the molecular layer, with a mediolateral extension of more than 1.2 mm and a rostrocaudal extension of over 0.8 mm. Non-GABAergic neurons in nearly the entire hilar area were found to project to the ipsilateral upper leaf of the molecular layer. In the dorsal CA1 region, GABAergic neurons in the stratum pyramidale and radiatum converged onto the ipsilateral stratum pyramidal/oriens, with a mediolateral extension of over 1 mm and a rostrocaudal extension of over 0.7 mm. These results provide direct evidence that in both the dentate gyrus and CA1, GABAergic interneurons from a fairly large field converge onto a very small target area. This suggests that the output signals from GABAergic neurons in the dentate gyrus and CA1, and non-GABAergic neurons in the dentate gyrus, may propagate beyond the anatomical limits contained in conventional slice preparations of the hippocampal formation.

Merocyanine 540-sensitized photoinactivation of leukemia cells: effects of dose fractionation

The differential sensitivity to merocyanine 540 (MC540)-sensitized photoirradiation of leukemia cells, selected solid tumor cells, and normal pluripotent hematopoietic stem cells has been successfully exploited for the extracorporeal purging of simulated autologous remission bone marrow grafts. In this communication, we compare the effects of fractionated vs continuous irradiation upon the MC540-sensitized photoinactivation of L1210 and K562 leukemia cells. Exposure to MC540 (15 micrograms/mL) and fractionated doses of white light inactivated fewer in vitro clonogenic cells than exposure to an equivalent dose of continuous irradiation, provided the irradiation doses were small (8.1-16.2 kJ/m2) and spaced 1-2 h apart. The dye-sensitized photoinactivation of leukemia cells was enhanced when cells were stored at 4 degrees C instead of 37 degrees C between irradiation periods, most likely in part because the cells were unable to repair sublethal photodynamic damages at the lower temperature. These data suggest that cells can recover from sublethal damage inflicted by the plasma membrane-active photosensitizer, MC540.

Limited cell-cycle dependence of the merocyanine 540-sensitized photoinactivation of L1210 leukemia cells

L1210 leukemia cells were synchronized by a double thymidine block technique and then characterized with regard to their susceptibility to merocyanine 540 (MC540)-sensitized photoinactivation. Cells harvested 5 (G2/M phase) h after release from the second thymidine block were most susceptible to MC540-sensitized photoinactivation followed, in order of decreasing sensitivity, by cells harvested 2 (S phase) h and by cells harvested 7 (G1 phase) h after release from the second block. The expression of dye-binding sites changed very little during the cell cycle.

Effect of argon laser and Photofrin II on murine neuroblastoma cells

Laser-induced fluorescence (LIF) of photosensitizers is used to detect cancer. The effect of argon laser light with an average irradiance of 31 mW cm-2 and Photofrin II (Dihematoporphyrin ether, DHE) at concentrations of 1.0 and 5.0 micrograms ml-1 on C1300 murine neuroblastoma cells (MNB, NB41A3) in vitro was investigated. Growth curves and cell viability (trypan blue dye exclusion) were determined at 1, 24, 96, and 144 hr post-irradiation. Light doses of 1.8 and 9.0 J cm-2 combined with 5.0 micrograms DHE ml-1 decreased both cell numbers and viability, immediately and up to 144 hr postirradiation. Argon laser light alone at a fluence of 9.0 J cm-2 caused reversible injury to the cells. This in vitro study shows that both low energy argon laser light and low dose DHE are cytocidal to C1300 MNB cells. LIF promises to aid in the detection and destruction of neuroblastoma. Surgeons should be aware that tissue irreversible damage is likely to occur when performing LIF detection of neuroblastoma. The doses of laser light and of Photofrin II found to be toxic to neuroblastoma cells in culture may provide guidelines for photodynamic therapy ablation of neuroblastoma clinically.

Comparison of local tumor recurrence following excision with the CO2 laser, Nd:YAG laser, and Argon Beam Coagulator

This study compares the incidence of local tumor recurrence following primary excision with the CO2 laser, Nd:YAG laser (contact), Argon Beam Coagulator, or electrocautery. One hundred eight Fisher 344 rats with R3230AC mammary tumors (1.6 +/- 0.04 [SD] cm diameter) were used. All animals were randomized into groups of similar tumor size. In groups C and CS, excision was performed with a Sharplan 1060 CO2 laser (TEMoo, 25 W, continuous wave [CW], 0.2-mm spot size). Wounds in group CS were "sterilized" (0.5-mm spot size, 25 W, CW) by gently heating the wound without causing blanching or charring. In group N, a 0.4-mm contact Laser Blade and a Cooper 8000 Nd:YAG laser at 20 W CW was used. In groups SA1 and SA2, tumors were excised with the scalpel, and hemostasis and wound "sterilization" were accomplished with the Bard System 6000 Argon Beam Coagulator (ABC) at 40 W and 4 liters/min argon gas flow in SA1 and 12 liters/min in SA2. In group E, excision was accomplished at 40 W blend mode, 10 W spray mode. In group EA, excision was accomplished at 60 W cutting current, and hemostasis was achieved with the ABC. The animals were examined for evidence of recurrence for 34 days postoperatively. Mortalities were excluded from analysis. The incidence of recurrence was 11/14 (79%) in C, 6/16 (38%) in CS, 10/14 (71%) in SA1, 6/13 (46%) in SA2, 6/15 (40%) in N, 7/10 (70%) in EA, and 3/15 (20%) in E. Group E is statistically different (P less than .01) from groups EA, C, and SA1. Group C was different (P less than .01) from groups E, CS, and N. These results demonstrate an inverse relationship between tumor recurrence and local thermal effects at the surgical site. The ABC did not increase tumor recurrence. Contact YAG surgery was similar to CO2 laser excision and "sterilization." An attempt to study the influence of gas flow and pressure on local tumor recurrence and metastases should be made.