Stability of standardized uptake values for quantitative bone SPECT for jawbone lesions: a single-center cross-sectional study.

BACKGROUND: The long time required for bone uptake of radiopharmaceutical material after injection for bone scintigraphy is a burden for patients with poor health. Thus, to assess whether the uptake time could be reduced for single-photon emission computed tomography (SPECT) of the jawbone, this study evaluated differences in maximum standardized uptake values (SUVmax) within patients using SPECT imaging at 2 and 3 hours after radiopharmaceutical injection. METHODS: A total of 33 patients undergoing treatment or in post-treatment follow-up for medication-related osteonecrosis of the jaw, who visited our hospital between July 2020 and August 2021 and could receive SPECT twice on the same day, were enrolled in the study. Patients were injected with technetium-99 m hydroxymethylene diphosphonate (Tc-99 m HMDP) intravenously. The SUVmax for healthy parietal bones and jawbone lesions were calculated from the SPECT images using quantitative analysis software, and the SUVmax were compared between 2- and 3-hour uptake times. RESULTS: After exclusion, 30 patients were included in the study. In the 2-hour and 3-hour images, the median SUVmax of the parietal bones were 1.90 and 1.81, respectively, and those of the jawbone lesions were 9.25 and 9.39, respectively. The limits of agreement (LOA) ranged from - 0.33 to 0.25 in the parietal bones, and the %LOA ranged from - 9.8 to 17.3% in the jawbone lesions, showing high equivalence between the two uptake durations. The SUVmax showed no clinical differences between the 2- and 3-hour uptake durations for Tc-99 m HMDP SPECT of the jawbone. CONCLUSIONS: The results of this study justify a 2-3-hour uptake window when performing quantitative SPECT of the jawbone. Therefore, the minimum uptake time can potentially be reduced to only 2 hours.

Photoinduced Kerr rotation spectroscopy for microscopic spin systems using heterodyne detection.

We develop a transient photoinduced Kerr rotation spectroscopy technique using a heterodyne detection scheme to study spin dynamics of microscopic quantum states in solids, such as single quantum dots and spin helixes. The use of the heterodyne beat note signal generated by the interference of the frequency-shifted probe and reference pulses realizes the Kerr rotation measurements in combination with micro-spectroscopy, even when the probe pulse propagates collinearly with the strong pump pulse, which resonantly excites the probing state. In addition, the interference gives an optical amplification of the Kerr signal, which provides a clear observation of the photoinduced spin dynamics by the weak probe intensity. Here, we present results of Kerr rotation measurements for a single quantum dot exciton, which shows a maximum rotation angle of few µrad.

Rapid Hypercalciuria Induction With Bone Formation Marker Reduction During Immobilization in Children.

OBJECTIVE: To prospectively examine the occurrence of hypercalciuria and changes in bone metabolite markers in pediatric patients during immobilization. METHODS: In total, 13 children with an orthopedic disease requiring immobilization longer than 2 weeks were enrolled. Blood samples were collected after breakfast. Urine samples were collected at the second voiding after waking. The urine calcium/creatinine (Ca/Cr) ratio and various bone metabolite parameters were measured before and every 1 to 4 weeks after the start of immobilization. RESULTS: The median patient age was 7 years with a range of 2 to 13 years. Orthopedic diseases in the patients were dislocated hip joint (N = 7), slipped capital femoral epiphysis (N = 2), etc. The urine Ca/Cr ratio increased significantly within a week after immobilization (P < .01) and continued to increase for 2 more weeks. Once immobilization ended, the urine Ca/Cr ratio gradually decreased and returned to the normal range approximately 6 weeks after mobility was achieved (P < .01). Serum alkaline phosphatase (ALP) and bone-specific ALP significantly decreased after immobilization began (P < .01). After immobilization ended, the serum ALP returned to preimmobilization levels in 2 to 4 weeks (P < .01). Serum N-terminal telopeptides did not change significantly during immobilization. CONCLUSION: The urine Ca/Cr ratio immediately increased after immobilization. In contrast to adults, bone formation markers in children decreased during immobilization, whereas bone resorption markers did not increase. To our knowledge, this study is the first to examine bone metabolism markers in children during immobilization.

Controlling Bi-Provoked Nanostructure Formation in GaAs/GaAsBi Core-Shell Nanowires.

We control the formation of Bi-induced nanostructures on the growth of GaAs/GaAsBi core-shell nanowires (NWs). Bi serves as not only a constituent but also a surfactant and nanowire growth catalyst. Thus, we paved a way to achieve unexplored III-V nanostructures employing the characteristic supersaturation of catalyst droplets, structural modifications induced by strain, and incorporation into the host GaAs matrix correlated with crystalline defects and orientations. When Ga is deficient during growth, Bi accumulates on the vertex of core GaAs NWs and serves as a nanowire growth catalyst for the branched structures to azimuthal <112>. We find a strong correlation between Bi accumulation and stacking faults. Furthermore, Bi is preferentially incorporated on the GaAs (112)B surface, leading to spatially selective Bi incorporation into a confined area that has a Bi concentration of over 7%. The obtained GaAs/GaAsBi/GaAs heterostructure with an interface defined by the crystalline twin defects in a zinc-blende structure can be potentially applied to a quantum confined structure. Our finding provides a rational design concept for the creation of GaAsBi based nanostructures and the control of Bi incorporation beyond the fundamental limit.

A novel truncating mutation in MYH3 causes spondylocarpotarsal synostosis syndrome with basilar invagination.

Spondylocarpotarsal synostosis syndrome (SCT) is a rare group of skeletal dysplasias, characterized by disproportionate short stature with a short trunk, abnormal segmentation of the spine with vertebral fusion, scoliosis and lordosis, carpal and tarsal synostosis, and mild facial dysmorphisms. While the majority of the cases show autosomal recessive inheritance, only a few cases of vertical transmissions, with MYH3 mutations, have been reported. Here we report a case with typical SCT, carrying a novel heterozygous mutation in MYH3. This observation supports the hypothesis of a pathogenic link between autosomal dominant SCT and heterozygous mutations in MYH3. Of note, our case showed basilar invagination on brain magnetic resonance imaging at the age of 10 years. Basilar invagination could be a rare complication of both autosomal recessive and dominant SCT, indicating that prompt investigation are warranted for SCT patients.

GaAsBi/GaAs multi-quantum well LED grown by molecular beam epitaxy using a two-substrate-temperature technique.

We report a GaAs0.96Bi0.04/GaAs multiple quantum well (MQW) light emitting diode (LED) grown by molecular beam epitaxy using a two-substrate-temperature (TST) technique. In particular, the QWs and the barriers in the intrinsic region were grown at the different temperatures of [Formula: see text] = 350 °C and [Formula: see text] respectively. Investigations of the microstructure using transmission electron microscopy (TEM) reveal homogeneous MQWs free of extended defects. Furthermore, the local determination of the Bi distribution profile across the MQWs region using TEM techniques confirm the uniform Bi distribution, while revealing a slightly chemically graded GaAs-on-GaAsBi interface due to Bi surface segregation. Despite this small broadening, we found that Bi segregation is significantly reduced (up to 18% reduction) compared to previous reports on Bi segregation in GaAsBi/GaAs MQWs. Hence, the TST procedure proves as a very efficient method to reduce Bi segregation and thus increase the quality of the layers and interfaces. These improvements positively reflect in the optical properties. Room temperature photoluminescence and electroluminescence (EL) at 1.23 µm emission wavelength are successfully demonstrated using TST MQWs containing less Bi content than in previous reports. Finally, LED fabricated using the present TST technique show current-voltage (I-V) curves with a forward voltage of 3.3 V at an injection current of 130 mA under 1.0 kA cm-2 current excitation. These results not only demonstrate that TST technique provides optical device quality GaAsBi/GaAs MQWs but highlight the relevance of TST-based growth techniques on the fabrication of future heterostructure devices based on dilute bismides.

Pediatric hypervirulent Klebsiella pneumoniae septic arthritis.

Cases of infection with hypervirulent Klebsiella pneumoniae are gradually increasing in number, and cause life-threatening community-acquired infection even in immunocompetent patients. A 14-year-old boy developed septic hip arthritis due to hypervirulent K. pneumoniae (sequence type 23, serotype K1, magA positive). The patient initially seemed to have been successfully treated with antibiotics and surgical intervention, but septic arthritis developed into osteomyelitis of the femoral head and myositis, which required long-term antibiotic therapy and additional surgical intervention. This is the first pediatric case of hypervirulent K. pneumoniae septic hip arthritis. Treatment plans should mainly consist of antibiotic therapy and surgical intervention. Clinicians, even pediatricians, in developed countries should be aware of the increasing incidence of hypervirulent Klebsiella pneumoniae infection.

Metamorphic GaAs/GaAsBi Heterostructured Nanowires.

GaAs/GaAsBi coaxial multishell nanowires were grown by molecular beam epitaxy. Introducing Bi results in a characteristic nanowire surface morphology with strong roughening. Elemental mappings clearly show the formation of the GaAsBi shell with inhomogeneous Bi distributions within the layer surrounded by the outermost GaAs, having a strong structural disorder at the wire surface. The nanowire exhibits a predominantly ZB structure from the bottom to the middle part. The polytipic WZ structure creates denser twin defects in the upper part than in the bottom and middle parts of the nanowire. We observe room temperature cathodoluminescence from the GaAsBi nanowires with a broad spectral line shape between 1.1 and 1.5 eV, accompanied by multiple peaks. A distinct energy peak at 1.24 eV agrees well with the energy of the reduced GaAsBi alloy band gap by the introduction of 2% Bi. The existence of localized states energetically and spatially dispersed throughout the NW are indicated from the low temperature cathodoluminescence spectra and images, resulting in the observed luminescence spectra characterized by large line widths at low temperatures as well as by the appearance of multiple peaks at high temperatures and for high excitation powers.

Effects of the chelating agent DTPA on naturally accumulating metals in the body.

Diethylenetriaminepentaacetate (DTPA) is the most widely used chelating agent for Pu and Am. Volunteers were assigned to receive intravenous injections or aerosol inhalations of 1 g of DTPA on days 1-4; volunteers received once daily injections of CaDTPA or ZnDTPA, CaDTPA inhalation as an aerosol, or CaDTPA injection on day 1 and ZnDTPA on days 2-4. CaDTPA injection or inhalation increased the excretion rates of Zn in urine with concomitantly reduced levels of serum Zn. Injection of CaDTPA reduced activities of serum alkaline phosphatase (AP) in parallel with the kinetics of Zn, whereas CaDTPA and ZnDTPA injection reduced activities of lactate dehydrogenase (LDH), and reduced activities of creatinine kinase (CK) were observed upon CaDTPA injection and its inhalation. Intravenous administration of CaDTPA and ZnDTPA enhanced excretion rates of Mn in urine, whereas transient reduction of Mn levels in serum was detected only via CaDTPA injection. Both CaDTPA and ZnDTPA transiently reduced levels of Mg in serum without affecting the excretion rates. On the other hand, both DTPAs increased excretion rates of toxic metals such as Pb and Cd, and CaDTPA also increased the rates of Hg. These results suggest that DTPA, and especially CaDTPA, removes essential metals and that the activities of these metalloenzymes are good indicators for the imbalance of essential metals during the DTPA administration. Our results also show that CaDTPA injection is more potent for removing these metals than ZnDTPA and inhalation of CaDTPA, and DTPA may be useful for the treatment of acute heavy metal poisoning with Pb, Cd, or Hg.

Musculoskeletal conditions of acute leukemia and malignant lymphoma in children.

We retrospectively reviewed 16 patients who presented to hospitals with orthopaedic complaints. Twelve patients experienced initial symptoms in the extremities and four patients had back pain. The leukocyte count was elevated in one patient, decreased in two patients, and normal in 13 patients. On radiographic examination, osteopenia was observed in 10 patients, osteolytic lesions were observed in five, and pathologic fractures were observed in five. Because the initial presentation of patients with leukemia often involves the musculoskeletal system, orthopaedists need to recognize the symptoms of this disease to avoid misdiagnosis and to expedite the initiation of appropriate potentially lifesaving treatment.