Low Incidence of Late Lymphopenia Following Stereotactic Body Radiotherapy for Localized Prostate Cancer

PURPOSE/OBJECTIVE(S)

Stereotactic body radiotherapy (SBRT) is increasing in use for the treatment of localized prostate cancer. The utilization of highly conformal photon therapy such as SBRT may increase the whole-body integral dose. Lymphocytes are very radiation sensitive. This dose increase could lead to unintended consequences such as lymphopenia. Prior studies have shown that lymphopenia following radiation therapy may negatively impact long-term outcomes. This study sought to evaluate the incidence and timeline of chronic lymphopenia following prostate SBRT.

MATERIALS/METHODS

Institutional IRB (IRB#: 2012-1175) approval was obtained. The absolute lymphocyte count was measured 1-2 hours prior to robotic SBRT (35-36.25 Gy in 5 fractions) and at each follow-up (3, 6, 12, 18 and 24 months). Lymphopenia was graded using the CTCAEv.4: Grade 1 (1.0-0.8 k/μl), Grade 2 (0.8-0.5 k/μl), Grade 3 (0.5-0.2 k/μl) and Grade 4 (<0.2 k/μl). Late lymphopenia was defined as lymphopenia occurring 3 or more months post-SBRT.

RESULTS

From 2019 to 2022, 198 localized prostate cancer patients (23 low-, 148 intermediate-, and 27 high-risk according to the D'Amico classification) at a median age of 73.5 years were treated with SBRT (35-36.25 Gy) at Georgetown University Hospital on a prospective clinical trial. Baseline lymphopenia was uncommon: Grade 1 (3.5%), Grade 2 (1.5%) and Grade 3 (0%). The baseline ALC of 1.9 k/μl decreased to 1.5 k/μl at 3 months post-SBRT and then remained stable for the remainder of the two-year follow-up. Overall, 14.6% of men experienced lymphopenia in the two years following SBRT: Grade 1 (7.6%), Grade 2 (6.6%) and Grade 3 (0.5%). No patient experienced Grade 4 lymphopenia.

CONCLUSION

Prostate SBRT leads to a low rate of late lymphopenia with the vast majority of toxicities being low grade. The peak incidence occurred at 3 months post-SBRT. Resolution of lymphopenia occurs in most patients within two years after SBRT. Future studies should explore the possible impact on quality of life and cancer control outcomes.

Acinetobacter quorum sensing contributes to inflammation-induced inhibition of orthopaedic implant osseointegration

Implant infection impairs osseointegration of orthopaedic implants by inducing inflammation. Acinetobacter spp. are increasingly prevalent multi-drug resistant bacteria that can cause osteomyelitis. Acinetobacter spp. can also cause inflammation and thereby inhibit osseointegration in mice. The purpose of the present study was to investigate the role of quorum sensing in this context. Therefore, wild-type bacteria were compared with an isogenic abaI mutant defective in quorum sensing in a murine osseointegration model. The abaI quorum- sensing mutant affected significantly less osseointegration and interleukin (IL) 1β levels, without detectably altering other pro-inflammatory cytokines. Wild-type bacteria had fewer effects on IL1 receptor (IL1R)-/- mice. These results indicated that quorum sensing in Acinetobacter spp. contributed to IL1β induction and the resultant inhibition of osseointegration in mice. Moreover, targeting the Gram-negative acyl-homoserine lactone quorum sensing may be particularly effective for patients with Acinetobacter spp. infections.

Comparison of different imaging models handling partial coherence for aberration-corrected HRTEM at 40-80 kV

Partial coherence of the electron waves leaving the specimen is taken into account in the high-resolution transmission electron microscopy (HRTEM) image simulation by mainly three methods - the incoherent summation approach, the transmission cross-coefficient (TCC) model, and the quasi-coherent model. In the incoherent summation approach, coherent images are calculated for each point in the effective source and summed up incoherently. The TCC is the transfer function of the microscope obtained based on the incoherent summation approach. An analytical form of the TCC can be derived by assuming a Gaussian distribution for the source radiation and for the variation of the focal length caused by the energy spread of the effective source. In the quasi-coherent model, the partial coherence effect is simplified by multiplying the wave function at the diffraction plane with the envelope functions. Envelope functions suppress the contributions to the image contrast from waves which do not propagate along the optical axis. The quasi-coherent model is usually sufficient for the image simulation of weak phase objects. This model is more computationally efficient than both the incoherent summation approach and the TCC model. For the C_s-corrected and C_c/C_s-corrected microscopes operating at 80 kV, we have compared images simulated by using the three models with the experimental images. The comparison shows that the quasi-coherent model also provides a sufficient approximation for the image simulation of high-Z materials if chromatic aberration is corrected and the samples comprise only several atomic layers. In the case of only C_s-correction, the incoherent summation approach or the TCC model needs to be employed for modelling the imaging of high-Z samples even though it is more computationally consuming.

Hypoplastic AI with Highly Variable Expressivity Caused by ENAM Mutations

Tooth enamel, the hardest tissue in the human body, is formed after a complex series of interactions between dental epithelial tissue and the underlying ectomesenchyme. Nonsyndromic amelogenesis imperfecta (AI) is a rare genetic disorder affecting tooth enamel without other nonoral symptoms. In this study, we identified 2 novel ENAM mutations in 2 families with hypoplastic AI by whole exome sequencing. Family 1 had a heterozygous splicing donor site mutation in intron 4, NM_031889; c.123+2T>G. Affected individuals had hypoplastic enamel with or without the characteristic horizontal hypoplastic grooves in some teeth. Family 2 had a nonsense mutation in the last exon, c.1842C>G, p.(Tyr614*), that was predicted to truncate the protein by 500 amino acids. Participating individuals had at least 1 mutant allele, while the proband had a homozygous mutation. Most interestingly, the clinical phenotype of the individuals harboring the heterozygous mutation varied from a lack of penetrance to a mild hypoplastic enamel defect. We believe that these findings will broaden our understanding of the clinical phenotype of AI caused by ENAM mutations.

High-resolution electrohydrodynamic inkjet printing of stretchable metal oxide semiconductor transistors with high performance

As demands for high pixel densities and wearable forms of displays increase, high-resolution printing technologies to achieve high performance transistors beyond current amorphous silicon levels and to allow low-temperature solution processability for plastic substrates have been explored as key processes in emerging flexible electronics. This study describes electrohydrodynamic inkjet (e-jet) technology for direct printing of oxide semiconductor thin film transistors (TFTs) with high resolution (minimum line width: 2 μm) and superb performance, including high mobility (∼230 cm² V^-1 s^-1). Logic operations of the amplifier circuits composed of these e-jet-printed metal oxide semiconductor (MOS) TFTs demonstrate their high performance. Printed In₂O TFTs with e-jet printing-assisted high-resolution S/D electrodes were prepared, and the direct printing of passivation layers on these channels enhanced their gate-bias stabilities significantly. Moreover, low process temperatures (<250 °C) enable the use of thin plastic substrates; highly flexible and stretchable TFT arrays have been demonstrated, suggesting promise for next-generation printed electronics.

Interventional stem cell therapy

The ability to deliver cells in appropriate doses to their targeted site of action is a well-known obstacle to optimising stem cell therapy. Systemic administration of cells results in pulmonary "trapping," which significantly decreases the number of available circulating cells to impact underlying disorders. Directed delivery of stem cells in interventional radiology may provide an additional option for bypassing the lungs, as well as introduce novel potential avenues for decreasing doses required to effect cellular therapy, efficiently obtain local paracrine effects, and/or to simplify targeting strategies.

Exonal Deletion of SLC24A4 Causes Hypomaturation Amelogenesis Imperfecta

Amelogenesis imperfecta is a heterogeneous group of genetic conditions affecting enamel formation. Recently, mutations in solute carrier family 24 member 4 ( SLC24A4) have been identified to cause autosomal recessive hypomaturation amelogenesis imperfecta. We recruited a consanguineous family with hypomaturation amelogenesis imperfecta with generalized brown discoloration. Sequencing of the candidate genes identified a 10-kb deletion, including exons 15, 16, and most of the last exon of the SLC24A4 gene. Interestingly, this deletion was caused by homologous recombination between two 354-bp-long homologous sequences located in intron 14 and the 3′ UTR. This is the first report of exonal deletion in SLC24A4 providing confirmatory evidence that the function of SLC24A4 in calcium transport has a crucial role in the maturation stage of amelogenesis.

PET imaging of hepatocellular carcinoma with 2-deoxy-2[18F]fluoro-D-glucose, 6-deoxy-6[18F] fluoro-D-glucose, [1-11C]-acetate and [N-methyl-11C]-choline

AIM

This study was designed to investigate the performance of positron emission tomography (PET) imaging for hepatocellular carcinoma (HCC) on a hepatitis viral infection-induced woodchuck model using existing tracers such as 2-deoxy-2[(18)F]fluoro-D-glucose (2FDG), 6-deoxy-6[(18)F]fluoro-D-glucose (6FDG), [1(-11)C]acetate (acetate) and [N-methyl(-11)C]choline (choline).

METHODS

Fourteen woodchucks with HCC were imaged with different radiotracers: 13 (10 with HCC and 3 controls) with 2FDG; 4 (3 with HCC and 1 control) with 6FDG; 13 (10 with HCC and 3 controls) with acetate; 4 (2 with HCC and 2 controls) with choline. The woodchucks were euthanized after imaging experiments and liver tissues were harvested for histology, for enzymatic activities including hexokinase (HK), glucose-6-phosphatase, acetyl-CoA synthetase (ACAS) and choline kinase (CK), and for differential gene expressions between the HCCs and the surrounding hepatic tissues.

RESULTS

2FDG detected 7/13 tumors with a tumor-to-liver uptake ratio (T/L) of 1.36+/-0.13. Five of these HCCs were moderately- or poorly-differentiated. The HK/glucose-6-phosphatase ratio was significantly higher in HCCs compared to the surrounding liver tissues (P=0.05). None of the HCCs imaged with 6FDG were detected by PET (T/L=1.01+/-0.11). Acetate detected 16/17 HCCs (T/L=2.02+/-0.7). ACAS activity was significantly higher in HCCs (P=0.01) and lipids-related genes were found up-regulated. Choline imaging detected all HCCs (T/L=1.63+/-0.34). CK activity was significantly higher in HCCs (P=0.001).

CONCLUSIONS

Well-differentiated and some moderately-differentiated HCCs do not uptake 2FDG more than the surrounding liver tissues, but display increased acetate uptake. There is no contrast between HCCs and the surrounding liver tissues on the 6FDG PET images. Despite elevated background signal from the liver, choline uptake seems to be detectable in the HCCs scanned in this study.

Dual MET-EGFR combinatorial inhibition against T790M-EGFR-mediated erlotinib-resistant lung cancer

Despite clinical approval of erlotinib, most advanced lung cancer patients are primary non-responders. Initial responders invariably develop secondary resistance, which can be accounted for by T790M-EGFR mutation in half of the relapses. We show that MET is highly expressed in lung cancer, often concomitantly with epidermal growth factor receptor (EGFR), including H1975 cell line. The erlotinib-resistant lung cancer cell line H1975, which expresses L858R/T790M-EGFR in-cis, was used to test for the effect of MET inhibition using the small molecule inhibitor SU11274. H1975 cells express wild-type MET, without genomic amplification (CNV = 1.1). At 2 microM, SU 11274 had significant in vitro pro-apoptotic effect in H1975 cells, 3.9-fold (P = 0.0015) higher than erlotinib, but had no effect on the MET and EGFR-negative H520 cells. In vivo, SU11274 also induced significant tumour cytoreduction in H1975 murine xenografts in our bioluminescence molecular imaging assay. Using small-animal microPET/MRI, SU11274 treatment was found to induce an early tumour metabolic response in H1975 tumour xenografts. MET and EGFR pathways were found to exhibit collaborative signalling with receptor cross-activation, which had different patterns between wild type (A549) and L858R/T790M-EGFR (H1975). SU11274 plus erlotinib/CL-387,785 potentiated MET inhibition of downstream cell proliferative survival signalling. Knockdown studies in H1975 cells using siRNA against MET alone, EGFR alone, or both, confirmed the enhanced downstream inhibition with dual MET-EGFR signal path inhibition. Finally, in our time-lapse video-microscopy and in vivo multimodal molecular imaging studies, dual SU11274-erlotinib concurrent treatment effectively inhibited H1975 cells with enhanced abrogation of cytoskeletal functions and complete regression of the xenograft growth. Together, our results suggest that MET-based targeted inhibition using small-molecule MET inhibitor can be a potential treatment strategy for T790M-EGFR-mediated erlotinib-resistant non-small-cell lung cancer. Furthermore, optimised inhibition may be further achieved with MET inhibition in combination with erlotinib or an irreversible EGFR-TKI.

DLX3 Mutation in a New Family and Its Phenotypic Variations

Tricho-dento-osseous syndrome (TDO) is an autosomal-dominant disease characterized by curly hair at birth, enamel hypoplasia, taurodontism, and a thick cortical bone. A common DLX3 gene mutation (c.571_574delGGGG) has been identified in multiple families with variable clinical phenotypes. Recently, another DLX3 gene mutation (c.561_562delCT) was reported to cause amelogenesis imperfecta with taurodontism (AIHHT). We identified a Korean family with overlapping phenotypes of TDO and AIHHT. We performed mutational analysis to discover its genetic etiology. The identified mutation was c.561_562delCT mutation in the DLX3 gene. The enamel was hypomature and hypoplastic. The characteristic taurodontic features were not identified. Increased bone density or thickness could not be revealed by cephalometric, hand-wrist, and panoramic radiographs. Affected individuals reported that their nails were brittle, and they had curly hair at birth. This study clearly showed that the c.561_562delCT mutation had not only enamel defects, but also other clinical phenotypes resembling those of TDO syndrome.

Tailoring the microstructure and surface morphology of metal thin films for nano-electro-mechanical systems applications

Metallic structural components for micro-electro-mechanical/nano-electro-mechanical systems (MEMS/NEMS) are promising alternatives to silicon-based materials since they are electrically conductive, optically reflective and ductile. Polycrystalline mono-metallic films typically exhibit low strength and hardness, high surface roughness, and significant residual stress, making them unusable for NEMS. In this study we demonstrate how to overcome these limitations by co-sputtering Ni-Mo. Detailed investigation of the Ni-Mo system using transmission electron microscopy and high-resolution transmission electron microscopy (TEM/HRTEM), x-ray diffraction (XRD), nanoindentation, and atomic force microscopy (AFM) reveals the presence of an amorphous-nanocrystalline microstructure which exhibits enhanced hardness, metallic conductivity, and sub-nanometer root mean square (RMS) roughness. Uncurled NEMS cantilevers with MHz resonant frequencies and quality factors ranging from 200-900 are fabricated from amorphous Ni-Mo. Using a sub-regular solution model it is shown that the electrical conductivity of Ni-Mo is in excellent agreement with Bhatia's structural model of electrical resistivity in binary alloys. Using a Langevin-type stochastic rate equation the structural evolution of amorphous Ni-Mo is modeled; it is shown that the growth instability due to the competing processes of surface diffusion and self-shadowing is heavily damped out due to the high thermal energies of sputtering, resulting in extremely smooth films.

Acute lung injury augments hypoxic ventilatory response in the absence of systemic hypoxemia

The objective of the present study was to examine the impact of early stages of lung injury on ventilatory control by hypoxia and hypercapnia. Lung injury was induced with intratracheal instillation of bleomycin (BM; 1 unit) in adult, male Sprague-Dawley rats. Control animals underwent sham surgery with saline instillation. Five days after the injections, lung injury was present in BM-treated animals as evidenced by increased neutrophils and protein levels in bronchoalveolar lavage fluid, as well as by changes in lung histology and computed tomography images. There was no evidence of pulmonary fibrosis, as indicated by lung collagen content. Basal core body temperature, arterial Po(2), and arterial Pco(2) were comparable between both groups of animals. Ventilatory responses to hypoxia (12% O(2)) and hypercapnia (7% CO(2)) were measured by whole body plethysmography in unanesthetized animals. Baseline respiratory rate and the hypoxic ventilatory response were significantly higher in BM-injected compared with control animals (P = 0.003), whereas hypercapnic ventilatory response was not statistically different. In anesthetized, spontaneously breathing animals, response to brief hyperoxia (Dejours' test, an index of peripheral chemoreceptor sensitivity) and neural hypoxic ventilatory response were augmented in BM-exposed relative to control animals, as measured by diaphragmatic electromyelograms. The enhanced hypoxic sensitivity persisted following bilateral vagotomy, but was abolished by bilateral carotid sinus nerve transection. These data demonstrate that afferent sensory input from the carotid body contributes to a selective enhancement of hypoxic ventilatory drive in early lung injury in the absence of pulmonary fibrosis and arterial hypoxemia.

The effect of scatter and attenuation on aerosol deposition as determined by gamma scintigraphy

Gamma scintigraphy is often used to quantify deposition patterns from aerosol inhalers. The errors caused by scatter and tissue attenuation in planar Tc-99m gamma scintigraphy were investigated based on the data collected from four subjects in this study. Several error correction methods were tested. The results from two scatter correction methods, Jaszczak's method and factor analysis of dynamic sequences (FADS), were similar. Scatter accounted for 20% of raw data in the whole lung, 20% in the oropharynx, and 43% in the central airways and esophagus. Three attenuation correction methods were investigated and compared. These were: uniform attenuation correction (UAC), a known method used for inhalation drug imaging work; the broad-beam attenuation correction used for organ imaging in nuclear medicine; and a narrow-beam inhomogeneous tissue attenuation correction proposed in this study. The three methods differed significantly (p < 0.05), but all indicated that attenuation is a severe quantification problem. The narrow beam attenuation correction with scatter correction, showed that raw data underestimated tracer deposition by 44% in the lung, 137% in the oropharynx, and 153% in the trachea/esophageal region. To quantify aerosol lung deposition using planar scintigraphy even in relative terms, corrections are necessary. Much of the literature concerning quantified aerosol dose distributions measured by gamma scintigraphy needs to be interpreted carefully.

Subclassification of preproliferative diabetic retinopathy and glycemic control: relationship between mean hemoglobin A1C value and development of proliferative diabetic retinopathy

PURPOSE

We evaluated the relationship between long-term glycemic control and the proportion of patients developing proliferative diabetic retinopathy (PDR) among cases with mild type preproliferative diabetic retinopathy (PPDR).

METHODS

The relationship was evaluated between the mean hemoglobin A1C (HbA1C) value during a period of at least 2 years and the proportion of patients developing PDR among cases with mild type PPDR, based on our previously proposed subclassification.

RESULTS

During follow-up, 27% of the total PPDR cases developed PDR. The mean HbA1C value in those patients who had developed PDR was 9.4% and was significantly higher than the 7.6% in those who had not developed PDR. The proportion developing PDR was 48% of the cases with a mean HbA1C value of 8.6% or more. By comparison, the proportion developing PDR was 8% among those with a mean HbA1C value below 8.6%. The proportion developing PDR was estimated to approximately double with each 1% increase in the mean HbA1C value. The cumulative occurrence rates of PDR at 2, 5, and 10 years were estimated to be 5%, 28%, and 60% in cases with a mean HbA1C value of 8.6% or more, and 0%, 7%, and 14% in those with a mean HbA1C value below 8.6%, respectively.

CONCLUSION

Stricter systemic and ophthalmological control is indicated for cases with a mean HbA1C value exceeding 8.6%.

Usefulness and pitfalls of planar gamma-scintigraphy for measuring aerosol deposition in the lungs: a Monte Carlo investigation

Planar gamma-scintigraphy is often used to quantify pulmonary deposition patterns from aerosol inhalers. The results are quite different from those obtained using 3-dimensional PET and SPECT. The purpose of this study was to characterize the effects of scatter and tissue attenuation on the distribution of radiolabeled aerosol as measured by planar scintigraphy using Monte Carlo simulations. This study also investigated the applicability of a few correction methods used in inhalation studies.

METHODS

Body density maps were derived from CT scans. Regions of interest-lungs, major airways, and esophagus-were defined from the same CT volume. Two radioactivity source distribution patterns in the lung, uniform and nonuniform, were used. A Monte Carlo program, SIMIND, was used to generate anterior and posterior gamma-images of the composed inhalation distributions for 2 energy windows, photopeak (127-153 keV) and scatter (92-125 keV). The effects of scatter and attenuation were estimated on the basis of the imaging components separated from the simulation. A scatter correction method and 2 attenuation correction methods, all applied to inhalation scintigraphy, were evaluated using the simulated images.

RESULTS

The amount of scatter ranges from 24% to approximately 29% in the lungs and from 29% to approximately 35% in the central (airway or esophagus) region on the planar images. Significant differences were found among regions and between source distributions (P < 0.05). The fraction k used for dual-energy-based scatter correction also varied and was found to be less than the commonly used k = 0.5. The simplified narrow-beam attenuation correction and the effective (broad-beam) correction methods were found to either under- or overcorrect the regional activities.

CONCLUSION

The amount of scatter and tissue attenuation in the thorax region depends on source distribution and body attenuation. In applying planar scintigraphy for aerosol inhalation studies, it is difficult to obtain precise quantitative measurements because of the uncertainties associated with scatter and attenuation corrections. Accurate corrections require knowledge of both source and density distributions.

[The sub-classification and long-term prognosis of preproliferative diabetic retinopathy]

PURPOSE

We followed eyes with preproliferative diabetic retinopathy(PPDR) for 2 or more years, and then evaluated the proportion of patients developing proliferative diabetic retinopathy(PDR) and the period from diagnosis of PPDR until development of PDR.

SUBJECTS AND METHODS

We divided 95 eyes affected by PPDR into 75 eyes with mild type and 20 eyes with moderate type based on our previously proposed sub-classification, and evaluated the long-term prognosis of 2 or more.

RESULTS

The proportion developing PDR was 24% in mild type and 60% in moderate type. The average period from diagnosis of PPDR until development of PDR was 6 years and 5 months in the mild type and 2 years in the moderate type. The accumulative occurrence rates of PDR at two, 5, and 10 years were estimated to be 0%, 14%, and 39% in the mild type and 35%, 58%, and 79% in the moderate type, respectively. The proportion developing PDR was significantly higher and the average period until PDR development significantly shorter in the moderate than in the mild type. In mild type eyes, the rate of progression to moderate type was 56% and further progression from moderate type to PDR was noted in 43%.

CONCLUSION

The above results again verify the usefulness of our sub-classification, and also provide useful information about the long-term prognosis of PPDR.

The use of bupropion in the treatment of restlessness after a traumatic brain injury

The occurrence of restlessness after a traumatic brain injury (TBI) is common. Severe restlessness can be a barrier in the multidisciplinary treatment of patients with TBI. The following case describes a patient with restlessness after a head-on motor vehicle accident. The patient was tachycardic, diaphoretic, demonstrating decerebrate posturing and a Rancho Los Amigos Stage II--III. Significant left lower leg restlessness was severe enough to cause bruising and ulceration. A multidisciplinary look was taken at the effects of using different neurotransmitter modulators in the treatment of restlessness after a TBI. Current biology treatment options include the use of medications that either modulate dopamine or noradrenaline alone. Bupropion effects both the dopaminergic and noradrenergic pathways. In the following case, the patient's restlessness was resistant to almost every medication employed. The only medication that proved to be effective in significantly reducing the patient's restlessness was bupropion. The evidence for the use of bupropion in the treatment of restlessness after a TBI has never been discussed previously, aside from anecdotal accounts. It is hoped that this case will prove insight into another treatment option for patients who have severe restlessness.

[Preproliferative diabetic retinopathy sub-classification and glycemic control--relationship between mean hemoglobin A1C value and development of proliferative diabetic retinopathy]

PURPOSE

We evaluated the relationship between long-term glycemic control and the proportion of patients developing proliferative diabetic retinopathy(PDR) in cases of mild preproliferative diabetic retinopathy(PPDR).

MATERIALS AND METHODS

We evaluated the relationship between the mean hemoglobin A1C (HbA1C) value during a period of at least 2 years and the proportion of patients developing PDR in cases of mild PPDR, based on our previously proposed subclassification.

RESULTS

During follow-up, 27% of all cases developed PDR. The mean HbA1C value in these cases was 9.4%, which was significantly higher than the 7.6% in cases which had not developed PDR. The proportion of patients developing PDR was 48% in cases with a mean HbA1C value 8.6% or more. In contrast, the proportion was 8% in cases with a mean HbA1C value below 8.6%. It was estimated that the proportion of patients developing PDR will approximately double if the mean HbA1C value increases by one percent. The cumulative occurrence rates of PDR at two, 5, and 10 years were estimated to be 5, 28, and 60% in cases with a mean HbA1C value 8.6% or more and 0, 7, and 10% in cases with a mean HbA1C value below 8.6%, respectively.

CONCLUSION

Based on the above results, we conclude that more strict systemic and ophthalmological control is indicated for patients with a mean HbA1C value exceeding 8.6%.

A comparison of biomechanical properties between human and porcine cornea

Due to the difficulty in obtaining human corneas, pig corneas are often substituted as models for cornea research. The purpose of this study is to find the similarities and differences in the biomechanical properties between human and porcine corneas. Uniaxial tests were conducted using an Instron apparatus to determine their tensile strength, stress-strain relationship, and stress-relaxation properties. The tensile strength and stress-strain relation were very similar but significant differences between the two tissues were observed in the stress-relaxation relationship. Under the same stretch ratio lambda=1.5, porcine cornea relaxed much more than human cornea. If tensile strength and the stress-strain relation are the only mechanical factors to be investigated, porcine cornea can be used as a substitute model for human cornea research. However, when stress relaxation is a factor, porcine corneas cannot be used as an appropriate model for human corneas in mechanical property studies. It is very difficult to get enough specimens of human cornea, so we did the experiments for stress-strain relationship at a specific value of strain rate (corresponding to the velocity of loading 10mm/min), and for stress relaxation at a specific stretch ratio lambda=1.5.

[Vitrectomy for diabetic cystoid macular edema]

PURPOSE

We evaluated the visual outcome of vitrectomy for diabetic cystoid macular edema.

METHODS

Visual outcome and factors which may influence final visual acuity were assessed and documented retrospectively in 45 eyes of 40 patients, all of whom were followed for at least 6 months postoperatively.

RESULTS

Final postoperative visual acuity was two or more lines better than preoperative visual acuity in 58%, within one line in 40%, and had decreased by two lines or more in 2%. A final postoperative visual acuity of 0.5 or better was achieved in 38%. Preoperative visual acuity and the extent of the cystoid space on fluorescein angiography were significantly related to final visual acuity. A final postoperative visual acuity of 0.5 or better was noted in 8% of eyes with a preoperative visual acuity below 0.1, in 50% of eyes with preoperative visual acuity of 0.1 or better, in 71% of eyes with a cystoid space smaller than 5 disc areas, and in 20% of eyes with a cystoid space of 5 disc areas or more. The posterior vitreous membrane condition did not influence final visual acuity. There were no complications which decreased visual acuity.

CONCLUSION

Based on the above results, we conclude that diabetic cystoid macular edema is a good indication for vitrectomy regardless of the posterior vitreous membrane condition. A preoperative visual acuity of 0.1 or better and/or a cystoid space smaller than 5 disc areas may be indications for surgery aimed at achieving a final postoperative visual acuity of 0.5 or better.

Pyrrolidine dithiocarbamate inhibits serum-induced NF-κB activation and induces apoptosis in ROS 17/2.8 osteoblasts

Nuclear factor-kappaB (NF-kappaB) activity affects cell survival in ROS 17/2.8 osteoblasts. Preventing NF-kappaB transcription activity with a potent NF-kappaB inhibitor, pyrrolidine dithiocarbamate (PDTC), results in apoptosis. Thus, we explored the effect of pyrrolidine dithiocarbamate (PDTC), which potently blocks the activation of nuclear factor-kappaB (NF-kappaB) in serum-exposed condition, on the activation of mitogen activated protein kinase (MAPK), especially, JNK/SAPK and p38 MAPK induction. PDTC transiently increased the phosphotransferase activity of c-Jun N-terminal Kinase1 (JNK1), which might in turn activates transcriptional activity of activating protein-1 (AP-1). The activation of JNK was completely decreased in dominant negative JNK1 transfected cells and the PDTC-induced cell death was attenuated in these cells. In addition, AP-1 activation was decreased in the JNK1 transfected cells, compared with vector-transfected cells. The NF-kappaB inhibitor also transiently activates p38 MAPK but SB203580, a specific p38 MAPK inhibitor, does not have any regulatory effect on PDTC-induced cell death, suggesting that the cell death is mediated by JNK not by p38 MAPK. Thus, overall, these results show that PDTC induces apoptosis and suggest that JNK/SAPK and subsequent AP-1 activation may be involved in the apoptotic pathway in ROS 17/2.8 osteoblasts.

Thresholding implemented in the frequency domain

Image processing procedures are usually carried out in the spatial domain where the images are acquired and presented/utilized. The linear nature of the Fourier transform allows only those operations that are linear to be mapped into the frequency domain. In contrast, nonlinear operations and manipulations cannot be realized directly in the frequency domain. One of these nonlinear operations is thresholding. When operating in the spatial domain to segment image contents into object and background, thresholding is simple and efficient. However, it has no obvious representation in the frequency domain and cannot be carried out there in a straightforward fashion. In this paper, a means to relax the rigid linear limitation of the Fourier transform was investigated. A novel approach was established to achieve spatial thresholding using only frequency domain operations. The spatial grayscale or scalar data set (two-dimensional (2-D) image or three-dimensional (3-D) volume) was expanded into a binary volume in hyperspace having one more dimension than the original data set. The extended dimension is the gray level of the original data. Manipulating only on that dimension produces the effect of thresholding.

Regional distribution and kinetics of inhaled pharmaceuticals

Drug biodistribution is often secondary to drug action. However, drugs that have a topical action and are deposited into the airway by inhalation are dependent on effective deposition at the intended site of action. Measurement of the distribution of such drugs in the airway is a useful tool. Distribution data can help to interpret clinical results, to evaluate products relative to each other, to optimize a new drug formulation, and to choose effective drug delivery methods. Imaging of radiotracers is the only means available to measure drug deposition throughout the lungs, nasal passages, and sinuses. There are several approaches to imaging drug deposition. Planar imaging has been the most used method, but SPECT and PET imaging are beginning to be applied effectively. The properties of non-drug tracers, labeling of drugs, evaluation of distribution patterns, and quantification of deposited drugs are important issues that have been addressed. Imaging has been shown to be a powerful technique to evaluate and to speed development of inhaled drugs. This review explores the most recent advances and issues with an emphasis on drug development.

Pulmonary distribution and kinetics of inhaled [11C]triamcinolone acetonide

Triamcinolone acetonide (TAA) is an anti-inflammatory steroid used for topical treatment of allergic rhinitis and asthma. Drug deposition onto target tissues is an important parameter, so methods for accurate deposition measurement are needed. Lung deposition is especially problematic to measure because of the large field of view and low relative drug penetration. Our main objective was to use PET to measure the deposition and postdeposition kinetics of TAA in the lung after administration from the Azmacort inhaler. The second objective was to evaluate changes in distribution caused by the inhalation spacer that is built into the product.

METHODS

11C-labeled TAA was formulated as the Azmacort product, 5 healthy volunteers inhaled it, and PET scans were obtained of its distribution in the head and chest. Region-of-interest analysis with CT overlay was used to analyze the distribution and kinetics in the airway and lung.

RESULTS

From 10% to 15% of the inhaled drug dose was deposited in target airway regions in a distally decreasing pattern. Deposition in the oral cavity was about 30% of the dose. Slow absorption or clearance of drug from target tissues was observed over time. Use of the inhalation spacer caused statistically significant increases in all target tissues (factor of 2-5) and a roughly 40% decrease in oral deposition. Measurable amounts of the drug remained in target regions throughout the scanning period.

CONCLUSION

Local pulmonary distribution and kinetics of inhaled drugs can be measured accurately by PET for drug development. The integrated actuator-spacer significantly enhanced deposition of TAA in target tissues and reduced deposition in the oropharyngeal region.

Band-ratio or spectral-curvature algorithms for satellite remote sensing?

For the retrieval of chlorophyll concentrations or the total absorption coefficients of oceanic waters based on water color, there are algorithms that use either band ratios or spectral curvatures of remote-sensing reflectance or water leaving radiance. We show that band-ratio algorithms have the potential to be applied to a wider dynamic range of oceanic waters, whereas spectral-curvature algorithms show stable performance as long as the data set falls within the appropriate range.

Mapping PET-measured triamcinolone acetonide (TAA) aerosol distribution into deposition by airway generation

The three dimensional (3D) distribution of inhaled drugs was measured using Positron Emission Tomography (PET) (Berridge, M.S, Muswick, G.J., Lee, Z., Leisure, G.L., Nelson, A.D., Muzic, R.F. Jr., Miraldi, F., Heald, D.L., 1997. PET evaluation of Azmacort(R) ([C-11]triamcinolone acetonide) dose administration. J. Nucl. Med. 38 (5) Suppl., 4-5). Data analysis was based upon regional ratios or penetration indices. To improve the analytical usefulness and objectivity, labeled drug from dynamic PET images was mapped into 23 airway generations following a general framework from a SPECT-based methodology (Fleming, J.S., Nassim, M.A., Hashish, A.H., Bailey, A.G. , Conway, J., Holgate, S., Halson, P., Moore, E., Martonen, T.B., 1995. Description of pulmonary deposition of radiolabeled aerosol by airway generation using a conceptual three dimensional model of lung morphology. J. Aerosol Med. 8, 341-356). A recently developed airway network model was used in this study. Quantitative PET scans of [C-11]triamcinolone acetonide distribution in the lung were determined following administration of Azmacort(R), a commercial metered dose inhaler with an integrated spacer device. Distributions at varying time periods after drug administration were investigated to explore the dynamics and kinetics of the aerosolized drug. Initially, deposition of labeled drug on conducting airways (generations 1-14) was found to be higher than those on acinar airways (generation 15-23), 64% versus 36%. The distribution pattern changed slowly with time. By 47 min, 51% of the dose remaining in the lung was found on conducting airways while 49% was on acinar airways. This study illustrates the value of PET imaging for the evaluation and design of drug formulations.

Hyperspectral remote sensing for shallow waters. 2. Deriving bottom depths and water properties by optimization

In earlier studies of passive remote sensing of shallow-water bathymetry, bottom depths were usually derived by empirical regression. This approach provides rapid data processing, but it requires knowledge of a few true depths for the regression parameters to be determined, and it cannot reveal in-water constituents. In this study a newly developed hyperspectral, remote-sensing reflectance model for shallow water is applied to data from computer simulations and field measurements. In the process, a remote-sensing reflectance spectrum is modeled by a set of values of absorption, backscattering, bottom albedo, and bottom depth; then it is compared with the spectrum from measurements. The difference between the two spectral curves is minimized by adjusting the model values in a predictor-corrector scheme. No information in addition to the measured reflectance is required. When the difference reaches a minimum, or the set of variables is optimized, absorption coefficients and bottom depths along with other properties are derived simultaneously. For computer-simulated data at a wind speed of 5 m/s the retrieval error was 5.3% for depths ranging from 2.0 to 20.0 m and 7.0% for total absorption coefficients at 440 nm ranging from 0.04 to 0.24 m(-1). At a wind speed of 10 m/s the errors were 5.1% for depth and 6.3% for total absorption at 440 nm. For field data with depths ranging from 0.8 to 25.0 m the difference was 10.9% (R2 = 0.96, N = 37) between inversion-derived and field-measured depth values and just 8.1% (N = 33) for depths greater than 2.0 m. These results suggest that the model and the method used in this study, which do not require in situ calibration measurements, perform very well in retrieving in-water optical properties and bottom depths from above-surface hyperspectral measurements.

Evaluation of the Periotest as a diagnostic tool for dental implants

The Periotest is examined as a possible replacement for outdated, inconsistent dental implant stability diagnosis tools. The Periotest has the advantage of offering reproducible findings by measuring the levels of subclinical mobility using an ultrasonically vibrating probe. The Periotest is successful in assessing the stability status of an implant, but it can detect the quantity of bony osseointegration only in terminal cases. Radiography proved to be a more sensitive method of determining pericervical bone loss; therefore, periapical radiographs in addition to the Periotest device were found to offer the most reliable assessment of an implant's status.

Hyperspectral remote sensing for shallow waters. I. A semianalytical model

For analytical or semianalytical retrieval of shallow-water bathymetry and/or optical properties of the water column from remote sensing, the contribution to the remotely sensed signal from the water column has to be separated from that of the bottom. The mathematical separation involves three diffuse attenuation coefficients: one for the downwelling irradiance (K(d)), one for the upwelling radiance of the water column (K(u)(C)), and one for the upwelling radiance from bottom reflection (K(u)(B)). Because of the differences in photon origination and path lengths, these three coefficients in general are not equal, although their equality has been assumed in many previous studies. By use of the Hydrolight radiative-transfer numerical model with a particle phase function typical of coastal waters, the remote-sensing reflectance above (R(rs)) and below (r(rs)) the surface is calculated for various combinations of optical properties, bottom albedos, bottom depths, and solar zenith angles. A semianalytical (SA) model for r(rs) of shallow waters is then developed, in which the diffuse attenuation coefficients are explicitly expressed as functions of in-water absorption (a) and backscattering (b(b)). For remote-sensing inversion, parameters connecting R(rs) and r(rs) are also derived. It is found that r(rs) values determined by the SA model agree well with the exact values computed by Hydrolight (~3% error), even for Hydrolight r(rs) values calculated with different particle phase functions. The Hydrolight calculations included b(b)/a values as high as 1.5 to simulate high-turbidity situations that are occasionally found in coastal regions.

Model for the interpretation of hyperspectral remote-sensing reflectance

Remote-sensing reflectance is easier to interpret for the open ocean than for coastal regions because the optical signals are highly coupled to the phytoplankton (e.g., chlorophyll) concentrations. For estuarine or coastal waters, variable terrigenous colored dissolved organic matter (CDOM), suspended sediments, and bottom reflectance, all factors that do not covary with the pigment concentration, confound data interpretation. In this research, remote-sensing reflectance models are suggested for coastal waters, to which contributions that are due to bottom reflectance, CDOM fluorescence, and water Raman scattering are included. Through the use of two parameters to model the combination of the backscattering coefficient and the Q factor, excellent agreement was achieved between the measured and modeled remote-sensing reflectance for waters from the West Florida Shelf to the Mississippi River plume. These waters cover a range of chlorophyll of 0.2-40 mg/m(3) and gelbstoff absorption at 440 nm from 0.02-0.4 m(-1). Data with a spectral resolution of 10 nm or better, which is consistent with that provided by the airborne visible and infrared imaging spectrometer (AVIRIS) and spacecraft spectrometers, were used in the model evaluation.

[Clinical study on 16 cases of testicular torsion]

Sixteen cases of testicular torsion were experienced between 1983 and 1988. Diagnosis was confirmed by surgical exploration in all cases. The patients' age was between 10 and 31 years. Fourteen patients (88%) were in their second decade. The left side was involved in 13 cases, the right side in 2 and both sides in 1. Shortness of spermatic cord of involved side was observed in 12 cases (75%). This seemed to be one of the most important signs in differential diagnosis between testicular torsion and other acute scrotum. Prehn's sign was not available. Body temperature was more than 37 degrees C in only 1 case. Urinary tract infection was not noted. Orchiopexy was performed in 12 cases. 9 cases (75%) were treated within 24 hours after onset of the symptom. Two cases (13%) were operated more than 72 hours after onset, but repaired testis was not atrophic one year after surgery.

[Two cases of male ectopic ureter with hydroureter]

Male ectopic ureters are relatively rare. We herein report two cases of male ectopic ureter. In case 1 a 34-year-old man had left renal hypertrophy incidentally found by ultrasonography. In case 2 a 58-year-old man had the chief complaint of urinary retention. These two patients had ectopic ureters opening into the posterior urethra with hydroureter and renal hypoplasia (Thom I), and nephroureterectomy were performed. There are 105 cases of male ectopic ureter in the Japanese literature. The type of the disease (according to Thom's classification), age distribution, opening site, associated abnormalities and treatment of male ectopic ureter were discussed.

Radiographic diagnosis of meconium peritonitis. A report of 200 cases including six fetal cases

The radiographic findings of 200 cases of meconium peritonitis were analyzed; 194 cases were discovered in newborn infants and six cases in fetuses. The radiographic features in the newborn group could be categorized as pneumoperitoneum with intestinal obstruction (adhesions) and calcification (35 cases), intestinal obstruction with calcification (143 cases), intestinal obstruction with no radiographically visible calcification (5 cases), and calcification alone (11 cases). All six cases of the fetal group were diagnosed when the mothers had been hospitalized for polyhydramnios and a plaque-like or ring-like calcification showed up in the fetal abdomen on the plain radiograph. Meconium peritonitis is one of the few conditions that can be diagnosed before birth and is almost the only condition around the time of birth to produce calcification in the abdomen. Therefore, if there is any sign of polyhydramnios, radiographs or ultrasonograms of the maternal abdomen should be obtained to detect any calcification within the peritoneal cavity of the fetus. A simple experiment carried out in rats showed that it takes at least eight days after the meconium escapes into the peritoneal cavity for calcification in the meconium to be radiographically demonstrable.