Possibilities and Limitations in Monomer Combinations for Ternary Two-Dimensional Covalent Organic Frameworks

The diversity and complexity of covalent organic frameworks (COFs) can be largely increased by incorporating multiple types of monomers with different topologies or sizes. However, an increase in the number of monomer types significantly complicates the COF formation process. Accordingly, much remains unclear regarding the viability of monomer combinations for ternary or higher-arity COFs. Herein, we show that, through an extensive examination of 12 two-nodes-one-linker ([2 + 1]) combinations, monomer-set viability is determined primarily by the conformational strain originating from disordered monomer arrangements, rather than other factors such as the difference in COF formation kinetics between monomers. When monomers cannot accommodate the strain associated with the formation of a locally disordered, yet crystalline framework, the corresponding [2 + 1] condensation yields a mixture of different COFs or an amorphous polymer. We also demonstrate that a node-linker pair that does not form a binary COF can be integrated to generate a single-phase framework upon addition of a small amount of the third component. These results will clarify the factors behind the successful formation of multicomponent COFs and refine their design by enabling accurate differentiation between allowed and disallowed monomer combinations.

The efficacy of general anesthesia during pulmonary vein isolation compared with conscious sedation

Background

Catheter ablation (RFA) is significantly more effective in terms of arrhythmia recurrence rate than antiarrhythmic medication. For the duration of the procedure, the patient needs to remain motionless on the operation table. General anesthesia (GA) is widely used during atrial fibrillation (AF) ablation in all over the world, however RFA of AF is performed under conscious sedation (CS) in the most centers in Japan.

It remains controversial whether cardiac anesthesiologists are best suited to manage anesthesia in the electrophysiology lab.

Objective

The aim of this study was to report the efficacy and safety of GA during AF ablation.

Methods

297 patients (67.3±11.7 years, 208 men, 128 paroxysmal, mean follow up 443 days±306) with AF undergoing RFA in our department from January 2018 to December 2021 were retrospectively analyzed. 113 assigned to the GA group, 184 patients to the CS group.

The primary efficacy end point was radiofrequency time, ablation index, force time integral. The secondary end points defined AF recurrence and the complications.

Result

There was no difference in the baseline characteristics between the two groups. There was no difference between groups in AF recurrence (22.1% vs. 14.1%, P=0.103) and complications.However, Patients in GA had shorter radiofrequency times (66.9±3.7 minute vs 79.0±2.9 minutes P=0.01)Ablation index (376±18.6 vs 371±22.6 P<0.05), Force time integral (136±22.3 vs 111.4±45.3).

Conclusion

General anesthesia is superior to conscious sedation with shorter radiofrequency times and higher than Force time integral, ablation index. Moreover, it is not inferior in regard to arrhythmia recurrence or complication rates of catheter ablation of atrial fibrillation.

Funding Acknowledgement

Type of funding sources: None.

Delayed fluorescence from inverted singlet and triplet excited states

Hund's multiplicity rule states that a higher spin state has a lower energy for a given electronic configuration¹. Rephrasing this rule for molecular excited states predicts a positive energy gap between spin-singlet and spin-triplet excited states, as has been consistent with numerous experimental observations over almost a century. Here we report a fluorescent molecule that disobeys Hund's rule and has a negative singlet-triplet energy gap of -11 ± 2 meV. The energy inversion of the singlet and triplet excited states results in delayed fluorescence with short time constants of 0.2 μs, which anomalously decrease with decreasing temperature owing to the emissive singlet character of the lowest-energy excited state. Organic light-emitting diodes (OLEDs) using this molecule exhibited a fast transient electroluminescence decay with a peak external quantum efficiency of 17%, demonstrating its potential implications for optoelectronic devices, including displays, lighting and lasers.

Electron spin resonance resolves intermediate triplet states in delayed fluorescence

Molecular organic fluorophores are currently used in organic light-emitting diodes, though non-emissive triplet excitons generated in devices incorporating conventional fluorophores limit the efficiency. This limit can be overcome in materials that have intramolecular charge-transfer excitonic states and associated small singlet-triplet energy separations; triplets can then be converted to emissive singlet excitons resulting in efficient delayed fluorescence. However, the mechanistic details of the spin interconversion have not yet been fully resolved. We report transient electron spin resonance studies that allow direct probing of the spin conversion in a series of delayed fluorescence fluorophores with varying energy gaps between local excitation and charge-transfer triplet states. The observation of distinct triplet signals, unusual in transient electron spin resonance, suggests that multiple triplet states mediate the photophysics for efficient light emission in delayed fluorescence emitters. We reveal that as the energy separation between local excitation and charge-transfer triplet states decreases, spin interconversion changes from a direct, singlet-triplet mechanism to an indirect mechanism involving intermediate states.

Regulation of Multicolor Fluorescence Changes Found in Donor-acceptor-type Mechanochromic Fluorescent Dyes

The regulation of multicolor fluorescence changes in mechanochromic fluorescence (MCF) remains a challenging task. Herein, we report the regulation of MCF using a donor-acceptor structure. Two crystal polymorphs, BTD-pCHO(O) and BTD-pCHO(R) produced by the introduction of formyl groups to an MCF dye, respond to a mechanical stimulus, allowing a three-color fluorescence change. Specifically, the orange-colored fluorescence of the metastable BTD-pCHO(O) polymorph changed to a deep-red color in the amorphous-like state to finally give a red color in the stable BTD-pCHO(R) polymorph. This change occurred by mechanical grinding followed by vapor fuming. The two different crystal packing patterns were selectively regulated by the electronic effect of the introduced functional groups. The two types of selectively formed crystals in BTD(F)-pCHO bearing fluorine atoms, and BTD(OMe)-pCHO bearing methoxy groups, respond to mechanical grinding, allowing for the regulation of multicolor MCL from a three-color change to two different types of two-color changes.

Thermal equilibration between singlet and triplet excited states in organic fluorophore for submicrosecond delayed fluorescence

In any complex molecular system, electronic excited states with different spin multiplicities can be described via a simple statistical thermodynamic formalism if the states are in thermal equilibrium. However, this ideal situation has hitherto been infeasible for efficient fluorescent organic molecules. Here, we report a highly emissive metal-free purely organic fluorophore that enables thermal equilibration between singlet and triplet excited states. The key to this unconventional excitonic behavior is the exceptionally fast spin-flipping reverse intersystem crossing from the triplet to singlet excited states with a rate constant exceeding 10⁸ per second, which is considerably higher than that of radiative decay (fluorescence) from the singlet excited state. The present fluorophoric system exhibits an emission lifetime as short as 750 nanoseconds and, therefore, allows organic light-emitting diodes to demonstrate external electroluminescence quantum efficiency exceeding 20% even at a practical high luminance of more than 10,000 candelas per square meter.

Safety and efficacy of a hyperaemic agent, intracoronary nicorandil 4mg, for invasive physiological assessments during fractional flow reserve measurement

Background

Fractional flow reserve (FFR) is one of most reliable index for the determining the functional severity coronary artery stenosis. Adenosine is the most commonly used agent for maximal hyperaemia. However, adenosine can cause chest discomfort, bronchial hyper-reactivity, and atrioventricular block. The aim of this study is to evaluate the safety and efficacy of intracoronary nicorandil as an alternative hyperaemic agent for FFR.

Methods and results

We enrolled consecutive 82 patients (87 lesions) who underwent FFR measurement in our center from Nov. 2018. We compared three groups; intravenous infusion of adenosine (150 μg/kg/min); and adenosine added intracoronary nicorandil 2mg; and intracoronary nicorandil 4mg. Mean FFR value was 0.83±0.09, 0.82±0.09, 0.82±0.08, There was a strong correlation among three groups (R2>0.9). Mean cyclic change in FFR was 0.026±0.023, 0.019±0.010, 0.016±0.014, respectively, cyclic change was smallest in intracoronary nicorandil 4mg group (vs ATP; p<0.001, vs ATP + nicorandil 2mg; p<0.001). By Wilcoxon test, mean FFR value of nicorandil 4mg was significant lower than ATP (p=0.0021), and equal to ATP + nicorandil 2mg (p=0.98).

Conclusions

Intracoronary nicorandil 4mg is a simple, safe, and effective way to induce steady-state hyperaemia for FFR.

Figure 1

Funding Acknowledgement

Type of funding source: None

Synthesis of Anthracene Derivatives with Azaacene-Containing Iptycene Wings and the Utilization as a Dopant for Solution-Processed Organic Light-Emitting Diodes

Substituted acene derivatives are regarded as promising materials for organic electronic devices such as organic light-emitting diodes (OLEDs). In particular, anthracene derivatives are known to exhibit good fluorescence property, with the air stability and solubility in common organic solvents expected to give advantages for solution-processed device fabrication. In this study, a series of bistriisopropylsilyl(TIPS)ethynyl anthracene derivatives with azaacene-containing iptycene wings have been synthesized by using condensation reactions. Effects of size of azaacenes on optical properties and packing structures were investigated. UV/Vis absorption and fluorescence spectra indicate that the π-elongation of iptycene units has small effects on the overall π-system, which is also supported by electrochemical measurements. Secondly, single-crystal X-ray analysis implies that the molecules likely have interactions with the iptycene units of adjacent molecules, while the iptycene wings and TIPSethynyl groups can prevent the central anthracene unit from undesirable non-radiative energy loss. Finally, the most emissive derivative was used as a dopant for solution-processed OLEDs, showing obvious electroluminescence with a luminance of over 920 cd m^-2 .

Room-Temperature Phosphorescence from a Series of 3-Pyridylcarbazole Derivatives

Exploration of pure metal-free organic molecules that exhibit strong room-temperature phosphorescence (RTP) is an emerging research topic. In this regard, unveiling the design principles for an efficient RTP molecule is an essential, but challenging, task. A small molecule is an ideal platform to precisely understand the fundamental role of each functional component because the parent molecule can be easily derivatized. Here, the RTP behaviors of a series of 3-pyridylcarbazole derivatives are presented. Experimental studies in combination with theoretical calculations reveal the crucial role of the n orbital on the central pyridine ring in the dramatic enhancement of the intersystem crossing between the charge-transfer-excited singlet state and the locally excited triplet states. Single-crystal X-ray crystallographic studies apparently indicate that both the pyridine ring and fluorine atom contribute to the enhancement of the RTP because of the restricted motion owing to weak C-H⋅⋅⋅N and H⋅⋅⋅F hydrogen-bonding interactions. The single crystal of the fluorine-substituted derivative shows an ultra-long phosphorescent lifetime (τ_P ) of 1.1 s and a phosphorescence quantum yield (Φ_P ) of 1.2 %, whereas the bromine-substituted derivative exhibits τ_P of 0.15 s with a Φ_P of 7.9 %. We believe that this work provides a fundamental and universal guideline for the generation of pure organic molecules exhibiting strong RTP.

Exciplex emissions derived from exceptionally long-distance donor and acceptor molecules

We report exceptionally long-distance coupled exciplex emissions between electron-donor and electron-acceptor molecules even with a 70 nm-thick spacer layer.

Intermolecular electron–hole coupling in organic semiconductor excited states plays important roles in organic light-emitting diodes and organic photovoltaics, and the distance of the coupling is typically only on the order of a few nanometers. Here, we report exceptionally long-distance coupled exciplex emissions between electron-donor and electron-acceptor molecules even with a 70 nm-thick spacer layer. Donor/spacer (∼70 nm)/acceptor-type stacked films showed a low-energy band emission, which is not ascribed to the emission of the donor, spacer, and acceptor themselves, but well corresponds to the energy difference between the highest occupied molecular orbital of the donor and the lowest unoccupied molecular orbital of the acceptor. Delayed transient photoluminescence (PL) and electroluminescence (EL) decays and PL quenching by oxygen at the low-energy band were observed and are consistent with the characteristics of the exciplex species.

Mechanochromic fluorescence based on a combination of acceptor and bulky donor moieties: tuning emission color and regulating emission change direction

Mechanochromic fluorescence based on a conventional strategy using a donor–acceptor structure bearing nonplanar three-dimensional donor moieties was studied.

High-Crystallinity π-Conjugated Small Molecules Based on Thienylene-Vinylene-Thienylene: Critical Role of Self-Organization in Photovoltaic, Charge-Transport, and Morphological Properties

Narrow-band-gap small molecules with π-extended backbones are promising donor materials for solution-processed bulk-heterojunction (BHJ) organic solar cells (OSCs). Herein, a series of acceptor-donor-acceptor (A-D-A) photovoltaic small molecules incorporating thienylene-vinylene-thienylene (TVT) as a central D unit and alkyl-substituted rhodanine or 2-(1,1-dicyanomethylene)rhodanine as terminal A units are designed and synthesized. Their physical properties including photoabsorption, electronic energy levels, hole mobility, and morphological characteristics are systematically investigated. Using solvent vapor annealing (SVA), the morphologies of the BHJ photoactive layers composed of these small-molecule donors and a [6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₁BM) acceptor can be properly modulated. As a result of increased crystallinity of the donors and desired phase segregation between the donors and PC₇₁BM upon rapid SVA treatment, the photovoltaic performances of the resultant OSC devices undergo drastic enhancement. The results reported here indicate that high-efficiency small-molecule OSCs can be achieved through rational design of the TVT-based molecular framework and optimization of the nanoscale phase-segregated morphology via proper SVA treatment.

Modulating Photo- and Electroluminescence in a Stimuli-Responsive π-Conjugated Donor-Acceptor Molecular System

Functional organic materials that display reversible changes in fluorescence in response to external stimuli are of immense interest owing to their potential applications in sensors, probes, and security links. While earlier studies mainly focused on changes in photoluminescence (PL) color in response to external stimuli, stimuli-responsive electroluminescence (EL) has not yet been explored for color-tunable emitters in organic light-emitting diodes (OLEDs). Here a stimuli-responsive fluorophoric molecular system is reported that is capable of switching its emission color between green and orange in the solid state upon grinding, heating, and exposure to chemical vapor. A mechanistic study combining X-ray diffraction analysis and quantum chemical calculations reveals that the tunable green/orange emissions originate from the fluorophore's alternating excited-state conformers formed in the crystalline and amorphous phases. By taking advantage of this stimuli-responsive fluorescence behavior, two-color emissive OLEDs were produced using the same fluorophore in different solid phases.

Solution-based electrical doping of semiconducting polymer films over a limited depth

Solution-based electrical doping protocols may allow more versatility in the design of organic electronic devices; yet, controlling the diffusion of dopants in organic semiconductors and their stability has proven challenging. Here we present a solution-based approach for electrical p-doping of films of donor conjugated organic semiconductors and their blends with acceptors over a limited depth with a decay constant of 10-20 nm by post-process immersion into a polyoxometalate solution (phosphomolybdic acid, PMA) in nitromethane. PMA-doped films show increased electrical conductivity and work function, reduced solubility in the processing solvent, and improved photo-oxidative stability in air. This approach is applicable to a variety of organic semiconductors used in photovoltaics and field-effect transistors. PMA doping over a limited depth of bulk heterojunction polymeric films, in which amine-containing polymers were mixed in the solution used for film formation, enables single-layer organic photovoltaic devices, processed at room temperature, with power conversion efficiencies up to 5.9 ± 0.2% and stable performance on shelf-lifetime studies at 60 °C for at least 280 h.

Versatile Molecular Functionalization for Inhibiting Concentration Quenching of Thermally Activated Delayed Fluorescence

Concentration quenching of thermally activated delayed fluorescence is found to be dominated by electron-exchange interactions, as described by the Dexter energy-transfer model. Owing to the short-range nature of the electron-exchange interactions, even a small modulation in the molecular geometric structure drastically affects the concentration-quenching, leading to enhanced solid-state photoluminescence and electroluminescence quantum efficiencies.

Serum Wisteria floribunda agglutinin-positive Mac-2-binding protein for patients with chronic hepatitis B and C: a comparative study

We compared Wisteria floribunda agglutinin-positive Mac-2-binding protein (WFA⁺ -M2BP) levels between patients with chronic hepatitis B (n=249) and chronic hepatitis C (n=386) based on the degree of liver fibrosis. We examined WFA⁺ -M2BP levels in patients with F4 (cirrhosis), F3 or more (advanced fibrosis) and F2 or more (significant fibrosis) in the two groups. We further examined the relationship between five fibrosis markers and the degree of fibrosis. The WFA⁺ -M2BP values ranged from 0.25 cut-off index (COI) to 12.9 COI in patients with hepatitis B and 0.34-20.0 COI in patients with hepatitis C (P<.0001). The median WFA⁺ -M2BP values in F4 in the two groups were 2.83 COI in patients with hepatitis B and 5.03 COI in patients with hepatitis C (P=.0046). The median WFA⁺ -M2BP values in F3 or more in the two groups were 1.79 COI in patients with hepatitis B and 3.79 COI in patients with hepatitis C (P<.0001). The median WFA⁺ -M2BP values in F2 or more in the two groups were 1.49 COI in the hepatitis B cohort and 3.19 COI in the hepatitis C group (P<.0001). Among five liver fibrosis markers, WFA⁺ -M2BP had the highest correlation coefficient (r_s =.629) in terms of correlation with the degree of fibrosis in the patients with hepatitis C and had the second highest r_s value (.415) in the hepatitis B group. Although WFA⁺ -M2BP could be a useful indicator of liver fibrosis, WFA⁺ -M2BP levels in the two groups significantly differed even in the same degree of fibrosis. Individual cut-off values in each aetiology for the degree of fibrosis should be determined.

Simultaneous cross-linking and p-doping of a polymeric semiconductor film by immersion into a phosphomolybdic acid solution for use in organic solar cells

Simultaneous cross-linking and p-doping of a polymeric semiconductor film was achieved by immersion into a phosphomolybdic acid solution for use in organic solar cells.

Fabrication of organic light-emitting devices comprising stacked light-emitting units by solution-based processes

Multi-organic light-emitting devices comprising two light-emitting units stacked in series through a charge-generation layer are fabricated by solution processes. A zinc oxide nanoparticles/polyethylene-imine bilayer is used as the electron-injection layer and phosphomolybdic acid is used as the charge-generation layer. Appropriate choice of solvents during spin-coating of each layer ensures the nine-layered structure fabricated by solution processes.

Instant low-temperature cross-linking of poly(N-vinylcarbazole) for solution-processed multilayer blue phosphorescent organic light-emitting devices

Poly(N-vinylcarbazole) undergoes cross-linking to highly solvent-resistant films through an oxidative coupling reaction, for which an annealing process takes only 3 min at 110 °C. This reaction allows the construction of a solution-processed multilayer OLED without a time-consuming annealing process. The maximum external quantum efficiency reaches 18%, and remains at 17%, even at a high brightness of 10 000 cd m(-2) for all-solution-processed blue OLEDs.

Anti-interferon-α neutralizing antibody is associated with nonresponse to pegylated interferon-α plus ribavirin in chronic hepatitis C

Pegylated interferon-α (PEG-IFN-α) plus ribavirin (RBV) treatment fails to achieve a sustained virological response (SVR) in approximately 20-50% of patients with chronic hepatitis C virus (HCV) infection. We assessed the contribution of an anti-IFN-α neutralizing antibody (NAb) on the nonresponse to treatment. NAbs were detected using an antiviral assay that assessed the neutralizing effects of serum samples against IFN. Serum samples were obtained at the end of the treatment and evaluated for the presence of NAbs using recombinant IFN-α as a standard. We studied 129 PEG-IFN-α/RBV-treated patients. In the 82 end-of-treatment responders, no NAbs were detected. Of the 47 patients who did not respond, seven (15%) were positive for NAbs. We also examined an additional 83 patients who had not responded to PEG-IFN-α treatment, and detected 12 with NAbs. Patients with good IFN-responsive characteristics, including HCV genotype 2/3 and major allele homozygotes for interleukin-28B, were included in the 19 patients with NAbs. No NAbs interfered with the antiviral activity of natural human IFN-β (nIFN-β) and re-treatement of patients with NAbs with nIFN-β/RBV achieved SVR. Our analyses revealed that the emergence of anti-IFN-α NAbs was a candidate causal factor of PEG-IFN-α-treatment failure. Therefore, these antibodies should be assayed in patients who do not respond to PEG-IFN-α therapy, and if detected, other effective treatments, i.e., medications that are not neutralized by anti-IFN-α NAbs, should be considered.

[A role of visiting nurses in providing the terminal patients with their desirable life-discussion regarding the place of death of the patients who were registered for visiting nurse system]

AIM

To evaluate the prognosis of the patients who had visiting nurse service and discuss the place of death (life at the terminal stage). To determine the roles of visiting nurses in providing the patients at a terminal stage with their desirable life till death.

METHODS

A total of 180 patients, who were registered for their home healthcare service in our Shonan Kamakura General Hospital and died between January 2000 and February 2001, were subjected to the study. All the subjects were classified into 3 groups according to the places of their death, 1) death at home, 2) death in the hospital and 3) death upon arrival after the admission to the hospital. Moreover, the following items were also surveyed and analyzed: 1) diagnosis (name of diseases), 2) cause of death, 3) age, 4) family structure, 5) whether their primary care physicians explained the prognosis and possible expected conditions to the patients and their family before hand, and 6) how the visiting nurses interact with the patients and their family members.

RESULTS

Sixty-six patients died at home, 105 in the hospital and 9 upon arrival at the hospital. During this survey period, there were a total of 5,274 and 5,574 visits by primary care physicians and visiting nurses, respectively. The patients who died at home were more often observed in the patients whose primary care physicians explained their conditions to them and whose visiting nurses closely related to them. Moreover, the patients with malignant tumor also more often died at home. On the contrary, there were very few patients with chronic diseases, with whom death at home was accepted and agreed before hand, and there were some cases with chronic diseases who died inside of the ambulance transported on the way to the hospital after a sudden change in their conditions.

DISCUSSION AND CONCLUSION

In order to have the patients live their desirable life till their death, it is required for the caretakers to prepare their mind for the day of the patient's death in addition to the patient's own wishes. For the patients with malignant tumor, it is easy to predict their prognosis, thus the caretakers can get prepared for the day of the patient's death. On the contrary, in case of the patients with chronic diseases, it is more difficult for the caretakers to experience an indefinite time with the patients since their prognosis is generally longer but the sudden change in their conditions may give the caretakers a high anxiety. Thus, it is essential for the visiting nurses to play a role as a mediator to interact between the patients and their family members, and their primary care physicians, and to establish a trustful relationship with the patients while their conditions are still stable. Moreover, similar to the malignant patients, the visiting nurses should explain the situations to the patients with chronic diseases, that they can choose the place of their own death and specific medical treatment at emergency and can decide the detail for their terminal stage with their family members. Thus, it was considered to be very important that the visiting nurses should frequently confirm these issues with the patients and their family according to their conditions.

[Serum antibodies to rubella virus in healthy individuals with indirect immunofluorescent method]

To investigate sensitivity to rubella virus (RV) in healthy individuals, we examined levels of antibodies to RV in sera by an indirect immunofluorescence assay (IFA) and compared levels of antibodies by IFA with those by a hemagglutination inhibition (HI) assay. Of 114 healthy individuals, we detected antibodies to RV in serum specimens from 103 (90.3%) by IFA and in those from 109 (95.6%) by HI assay. The peak value of levels of antibodies by HI assay was 4 fold higher than that by IFA. When levels of antibodies by IFA were less than 32, levels of antibodies by HI assay ranged from < 8 to 1024. We did not detect anti-rubella antibodies of IgM class in all serum specimens and detected anti-rubella antibodies of IgA class in serum from only 1 individual by IFA. We detected antibodies to rubella in sera from 51 (94.4%) by IFA and in sera from 52 (96.3%) by HI assay of 54 individuals who reported having had rubella, and in sera from 23 (88.5%), by IFA and in sera from 26 (100%) by HI assay of 26 individuals reported having been vaccinated. Also, we detected anti-rubella antibodies in sera from 13 (76.5%) by IFA and in sera from 15 (88.2%) by HI of 17 individuals who reported having had neither rubella nor vaccination. In serum from 1 individual who reported having had rubella, we detected antibodies to rubella by IFA but not by HI assay. In serum specimens from 2 individuals who reported having had rubella vaccination, from 3 having had vaccination, from 2 having had neither rubella nor vaccination, we detected anti-rubella antibodies by HI assay but not by IFA. On the other hand, by both assays, we detected antibodies to RV in all sera of individuals who reported having had rubella and been vaccinated. The serodiagnosis, at least, by two methods is necessary to prevent individuals from rubella virus infection, because of following results: 1) influence of an inhibitor in serum specimens was thought to be variable. 2) The results measured by IFA were differed from those by HI assay in some individuals. 3) It is difficult in diagnosis of rubella from clinical symptoms alone. Also, it might be required to use vaccine to the individual who lacks detectable antibodies to rubella in serum by any method to prevent rubella infection.

[The usefulness of the emergency hepatobiliary scintigraphy to rule out acute cholecystitis--43 patients report]

We studied emergency hepatobiliary scintigraphy in the 43 patients to rule out acute cholecystitis. After injection of 185-222 MBq (5-6 mCi) of 99mTc-EHIDA or 99mTc-HIDA, serial static scintigraphic images were obtained up to 7 hours in maximum. Of 43 patients in this study, 20 had a normal scan and finally in all of them cholecystitis was ruled out. Of the 43 patients, 14 had an abnormal scan (nonvisualized gall bladder). In 10 of them the diagnosis of acute cholecystitis was confirmed after emergency cholecystectomy. The other 9 patients of 43 had an incomplete scan mainly due to liver dysfunction. Four of them had acute cholecystitis in the cholecystectomy. These results indicate that acute cholecystitis can be excluded by the findings of gall bladder visualization in hepatobiliary scintigram. We concluded that emergency hepatobiliary scintigraphy is very useful to rule out acute cholecystitis.

[Clinical usefulness of scintigraphy with 99m technetium phosphates in rhabdomyolysis]

We performed bone scans with 99mTechnetium phosphates in 15 cases of clinically suspected rhabdomyolysis admitted to Chigasaki Tokushukai Hospital. Whole body scans were performed within 5 days from the onset of illness or admission. Accumulation of the radioactivity in the skeletal muscle was revealed in 13 of the 15 cases and the involved muscle groups were visualized vividly. Etiologies of rhabdomyolysis were diverse, ranging from malignant syndrome to sepsis. Myocardial concentration was absent in all of the cases. Renal concentration of the isotope was seen in cases where the degree of rhabdomyolysis was higher and renal impairment was present. We conclude that 99mTechnetium phosphate bone scan is useful in clinically suspected rhabdomyolysis as a diagnostic test and as a test to localize and quantitate the muscular involvement.

A large degenerated subserous leiomyoma of the uterus: uncommon scintigraphic and ultrasonographic findings

Bone imaging is commonly used as a sensitive indicator of metastatic bone diseases or other bone pathology. Furthermore, it is now generally known that technetium-99m (99mTc) phosphonates tend to concentrate in various tissues other than bones. Ultrasonography is also widely used for the evaluation of pelvic masses. Ultrasonography is especially useful for detecting a cystic mass. We present a case where the uptake of 99mTc phosphonate compounds occurred in the entire abdomen, and ultrasonography suggested a diagnosis of pseudomyxoma peritonei, but the condition was later proven to be degeneration of giant subserous leiomyoma of the uterus. We have found two interesting features in this case. One is the 99mTc phosphonate concentration in the large cystic and hyaline degeneration of subserous leiomyoma of the uterus without calcification, and the other is the sonographic finding of a large echogenic mass with innumerable small anechoic areas. To our knowledge, no cases of 99mTc phosphonate concentration in non-calcified leiomyoma of the uterus have been demonstrated.

Role of angiotensin II in the pathogenesis of hyperdipsia in chronic renal failure

The relation of thirst to the renin-angiotensin system was examined in 38 patients with chronic renal failure receiving hemodialysis treatment. They were classified into three groups, ie, group 1 (19 patients), no or modest thirst; group 2 (13 patients), moderate thirst; and group 3 (six patients), excessive thirst. The plasma renin activity, plasma angiotensin II levels, and interdialytic weight gains of groups 1 to 3 significantly increased in a progressive manner with intensity of thirst. The hyperdipsia experienced by four patients in group 3 ameliorated after administration of an angiotensin-converting-enzyme inhibitor. The hyperdipsia of some patients with chronic renal failure therefore appears to be mediated by increased production of endogenous angiotensin II.

Translocation of polychlorobiphenyls in soil into plants: a study by a method of culture of soybean sprouts

PCB translocation from soil into a plant through its roots was investigated by a method of culture of soybean sprouts on sand contaminated with Aroclor 1242 or 1254. A preliminary culture was carried out on clean sand in a cage with small holes in the bottom and then followed by a main culture on contaminated sand after the preliminary culture cage was placed upon a box filled with the contaminated sand. Consequently, roots of soybean sprouts were allowed to penetrate through the holes at the botton of the upper cage into the contaminated sand. Rates of transference of PCBs were found to be different among chlorobiphenyl isomers; low chlorobiphenyls were much more preferentially absorbed by sprouts that were the high chlorobiphenyls. This seemed to depend mostly on different water solubilities of the isomers and probably not on selective absorption of the isomers by sprouts. The usefulness of the method employed of the two-steps sprout culture on doubly layered soil, in investigations of translocation mechanisms of toxic chemicals in a soil-plant ecosystem, is also discussed.