Non-severe Serovar Type E Capnocytophaga canimorsus Infection in a Post-splenectomy Male: A Case Report

Capnocytophaga canimorsus (CP) causes severe infections in immunocompromised individuals. Three serovars (A, B, and C) are known to be responsible for more than 90% of infections associated with dog bites, although these three constitute only 8% of the serovars carried by dogs. We experienced a post-splenectomy non-severe case of CP withserovar type E, which has never been isolated in Japan. The prognosis of type E CP infections may be better than that of types A, B, and C infections because of the disproportion of serovars between clinical human isolates and dog oral isolates.

A case of hemorrhagic shock in a patient with neurofibromatosis type 1

Complications of neurofibromatosis type 1 include fatal bleeding events due to vascular fragility. In this case of hemorrhagic shock due to a neurofibroma, the bleeding was controlled using an occlusion balloon and endovascular treatment which stabilized the patient. Systemic vascular investigation for bleeding sites is important to prevent fatal outcomes.

Effect of Past Chlamydophila pneumoniae Infection on the Short-Time Mortality of COVID-19: A Retrospective Cohort Study

BACKGROUND

Although Chlamydophila pneumoniae (CP)is known to play a role in atherosclerosis and endothelial injury, its past infection on the mortality of coronavirus disease 2019 (COVID-19), which was also reported to be a vascular disease, remains unknown.

METHODS

In this retrospective cohort study, we examined 78 COVID-19 patients and 32 bacterial pneumonia patients who visited a tertiary emergency center in Japan between April 1, 2021, and April 30, 2022. CP antibody levels, including IgM, IgG, and IgA, were measured.

RESULTS

Among all patients, the CP IgA-positive rate was significantly associated with age (P = 0.002). Between the COVID-19 and non-COVID-19 groups, no difference in the positive rate for both CP IgG and IgA was observed (P = 1.00 and 0.51, respectively). The mean age and proportion of males were significantly higher in the IgA-positive group than in the IgA-negative group (60.7 vs. 75.5, P = 0.001; 61.5% vs. 85.0%, P = 0.019, respectively). Smoking and dead outcomes were significantly higher both in the IgA-positive group and IgG-positive group (smoking: 26.7% vs. 62.2, P = 0.003; 34.7% vs. 73.1%, P = 0.002, dead outcome: 6.5% vs. 29.8%, P = 0.020; 13.5% vs. 34.6%, P = 0.039, respectively). Although the log-rank test revealed higher 30-day mortality in the IgG-positive group compared to the IgG-negative group (P = 0.032), Cox regression analysis demonstrated no significant difference between the IgG-positive and negative groups (hazard ratio (HR) = 4.10, 95%CI = 0.94-18.0, P = 0.061).

CONCLUSION

The effect of past CP infection on 30-day mortality in COVID-19 patients was not obvious.

Continuous positive airway pressure treatment from the prehospital field in a Japanese regional Doctor Car system

Background

Continuous positive airway pressure (CPAP) therapy is an effective treatment for patients with severe heart failure, and certain guidelines recommend its early initiation. However, the current Japanese law strictly prohibits paramedics from administering this treatment. To demonstrate the efficacy and safety of prehospital administration of CPAP therapy, this study was conducted by the Yokohama Medical Control Council (Yokohama MC).

Methods

The Yokohama MC established a protocol for CPAP treatment and dispatched Doctor Cars to attend to patients with severe respiratory failure. The Boussignac CPAP system was installed in all Yokohama Doctor Cars, including Workstation-type Doctor Cars and Hospital-type Doctor Cars. Data from this study were collected and recorded in the Yokohama City Doctor Car Registry system from October 2020 to January 2022.

Results

The Doctor Car was dispatched 661 times, and CPAP therapy was administered to 13 patients in the prehospital field. It is important to note that the number of CPAP cases was lower than anticipated due to the coronavirus disease 2019 (COVID-19) pandemic, given concerns about aerosol production. When assessing changes over time in oxygen saturation (SpO2), the median (interquartile range), excluding missing values, was 89% (83%-93%) without oxygen, 95% (94%-99.3%) with oxygen, and 100% (97%-100%) with CPAP. The differences between these groups were statistically significant with a p-value of <0.0001. Respiratory distress was primarily attributed to heart failure in 10 patients (91%) and pneumothorax in 1 patient (9%). Notably, none of the patients' conditions worsened after the use of CPAP.

Conclusion

We have detailed the administration of CPAP therapy in the prehospital field within a local city in Japan. To the best of our knowledge, this represents the inaugural report of a prospective observational study on the prehospital administration of CPAP therapy originating from Japan.

Utility of dual-energy computed tomography in the association of COVID-19 pneumonia severity

Aim

Coronavirus disease 2019 pneumonia differs from ordinary pneumonia in that it is associated with lesions that reduce pulmonary perfusion. Dual-energy computed tomography is well suited to elucidate the etiology of coronavirus disease 2019 pneumonia, because it highlights changes in organ blood flow. In this study, we investigated whether dual-energy computed tomography could be used to determine the severity of coronavirus disease 2019 pneumonia.

Methods

Patients who were diagnosed with coronavirus disease 2019 pneumonia, admitted to our hospital, and underwent dual-energy computed tomography were included in this study. Dual-energy computed tomography findings, plane computed tomography findings, disease severity, laboratory data, and clinical features were compared between two groups: a critical group (18 patients) and a non-critical group (30 patients).

Results

The dual-energy computed tomography results indicated that the percentage of flow loss was significantly higher in the critical group compared with the non-critical group (P < 0.001). Additionally, our data demonstrated that thrombotic risk was associated with differences in clinical characteristics (P = 0.018). Receiver operating characteristic analysis revealed that the percentage of flow loss, evaluated using dual-energy computed tomography, could predict severity in the critical group with 100% sensitivity and 77% specificity. However, there were no significant differences in the receiver operating characteristic values for dual-energy computed tomography and plane computed tomography.

Conclusion

Dual-energy computed tomography can be used to associate the severity of coronavirus disease 2019 pneumonia with high accuracy. Further studies are needed to draw definitive conclusions.

Acute pancreatitis caused by duodenal bezoar and treated with endoscopic procedures

Background

Acute pancreatitis triggered by causative agents, including alcohol consumption, gallstones, dyslipidemia, drugs, and infection, is frequently addressed. However, reports of acute pancreatitis caused by duodenal bezoars are limited.

Case Presentation

A 75-year-old man experiencing abdominal pain and frequent vomiting was transferred to our hospital. His medical records presented history of diabetes, hypertension, dyslipidemia, and gastric cancer surgery. Computed tomography of the abdomen indicated duodenal dilatation, enlarged pancreas, and fluid retention, with no bile duct stones present. Minor bleeding and duodenal bezoar were endoscopically detected with esophagogastroduodenoscopy (EGD). He was diagnosed with severe acute pancreatitis caused by a bezoar and admitted to the intensive care unit. The duodenal bezoar was dissected and removed with three repetitions of EGD, and the patient was discharged without any complications.

Conclusion

Herein, we report a case showing that endoscopic procedures could be effective treatment options in severe pancreatitis caused by duodenal bezoars.

Lemierre’s Syndrome as a Sexually Transmitted Disease Due to Porphyromonas asaccharolytica Suspected to Be Caused by Pharyngitis Due to Mycoplasma pneumoniae and Epstein-Barr Virus

Porphyromonas asaccharolytica rarely causes Lemierre's syndrome (LS), which is characterised by sepsis and thrombophlebitis of the internal jugular vein.

An 18-year-old man presented with fever and a sore throat after sexual contact containing oral sex, and his blood sample was positive for atypical lymphocytes. Infectious mononucleosis was suspected initially. However, laboratory data showed elevated D-dimer and procalcitonin levels, and a computed tomography scan showed a thrombus in the internal jugular vein leading to the diagnosis of LS. The Mycoplasma pneumoniae (MP) IgM titre was 1:640 (normal, ≦1:40), and the Epstein-Barr nuclear antigen titre (taken 59 days after admission) was 1:10 (normal, <1:10). It was assumed that LS developed after infection with Epstein-Barr virus (EBV) and MP.

LS should be suspected in young patients with fever and sore throat with a history of recent sexual contact. As pharyngitis was considered the cause of LS, evaluation of the preceding infection such as MP or EBV leading to pharyngitis should also be considered.

Awake intubation with videolaryngoscopy and fiberoptic bronchoscope

By combining video laryngoscopy and fiberoptic bronchoscopy, awake intubation can be performed more safely.

Two cases of post-traumatic inferior vena cava thrombosis

Background

Inferior vena cava thrombosis is a rare blunt abdominal trauma complication often associated with severe liver injury. We present two cases of inferior vena cava thrombosis due to mild liver injuries.

Case Presentation

Case 1 was a 25-year-old woman taking oral contraceptives for dysmenorrhea who was injured in a motorcycle accident. Contrast-enhanced computed tomography revealed hepatic contusion of the sixth segment. At 1 week after the accident, inferior vena cava thrombosis was detected. Case 2 was a 58-year-old man injured in a motorcycle accident. Contrast-enhanced computed tomography showed traumatic subarachnoid hemorrhage, right hemothorax, and liver injury with hepatic contusion of the sixth segment. At 1 week after the accident, inferior vena cava thrombosis was observed.

Conclusion

Inferior vena cava thrombosis can occur following liver injury, regardless of damage severity. When there are thrombogenic factors and damage near the inferior vena cava, follow-up examinations should be carried out.

Combining IL-6 and SARS-CoV-2 RNAaemia-based risk stratification for fatal outcomes of COVID-19

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic rapidly increases the use of mechanical ventilation (MV). Such cases further require extracorporeal membrane oxygenation (ECMO) and have a high mortality.

OBJECTIVE

We aimed to identify prognostic biomarkers pathophysiologically reflecting future deterioration of COVID-19.

METHODS

Clinical, laboratory, and outcome data were collected from 102 patients with moderate to severe COVID-19. Interleukin (IL)-6 level and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA copy number in plasma were assessed with ELISA kit and quantitative PCR.

RESULTS

Twelve patients died or required ECMO owing to acute respiratory distress syndrome despite the use of MV. Among various variables, a ratio of oxygen saturation to fraction of inspired oxygen (SpO2/FiO2), IL-6, and SARS-CoV-2 RNA on admission before intubation were strongly predictive of fatal outcomes after the MV use. Moreover, among these variables, combining SpO2/FiO2, IL-6, and SARS-CoV-2 RNA showed the highest accuracy (area under the curve: 0.934). In patients with low SpO2/FiO2 (< 261), fatal event-rate after the MV use at the 30-day was significantly higher in patients with high IL-6 (> 49 pg/mL) and SARS-CoV-2 RNAaemia (> 1.5 copies/μL) compared to those with high IL-6 or RNAaemia or without high IL-6 and RNAaemia (88% vs. 22% or 8%, log-rank test P = 0.0097 or P < 0.0001, respectively).

CONCLUSIONS

Combining SpO2/FiO2 with high IL-6 and SARS-CoV-2 RNAaemia which reflect hyperinflammation and viral overload allows accurately and before intubation identifying COVID-19 patients at high risk for ECMO use or in-hospital death despite the use of MV.

DUAL-energy computed tomography findings in a case of COVID-19

Background

COVID-19 pneumonia has lesions with a decreased blood flow. Dual-energy computed tomography is suitable to elucidate the pathogenesis of COVID-19 pneumonia because it highlights the blood flow changes in organs. We report the dual-energy computed tomography findings of a successfully treated case of COVID-19 pneumonia.

Case Presentation

An obese 49-year-old man with COVID-19 pneumonia was transferred from another hospital on day 11 after onset of illness. Although he was hypoxemic (PaO₂/FiO₂ = 100), tracheal intubation was not performed after anticipating difficulty in weaning from mechanical ventilation. Prone position therapy and nasal high flow therapy were administered, and the patient was discharged after his condition improved. Dual-energy computed tomography was performed three times during hospitalization, and it revealed improvement in the blood flow defect, unlike plain computed tomography that did not show much improvement.

Conclusion

Dual-energy computed tomography can assess perfusion in COVID-19 pneumonia in real time and may be able to predict its severity.

Clinical course of 2019 novel coronavirus disease (COVID-19) in individuals present during the outbreak on the Diamond Princess cruise ship

We investigated the clinical course of individuals with 2019 novel coronavirus disease (COVID-19) who were transferred from the Diamond Princess cruise ship to 12 local hospitals. The conditions and clinical courses of patients with pneumonia were compared with those of patients without pneumonia. Among 70 patients (median age: 67 years) analyzed, the major symptoms were fever (64.3%), cough (54.3%), and general fatigue (24.3%). Forty-three patients (61.4%) had pneumonia. Higher body temperature, heart rate, and respiratory rate as well as higher of lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and C-reactive protein (CRP) levels and lower serum albumin level and lymphocyte count were associated with the presence of pneumonia. Ground-glass opacity was found in 97.7% of the patients with pneumonia. Patients were administered neuraminidase inhibitors (20%), lopinavir/ritonavir (32.9%), and ciclesonide inhalation (11.4%). Mechanical ventilation and veno-venous extracorporeal membrane oxygenation was performed on 14 (20%) and 2 (2.9%) patients, respectively; two patients died. The median duration of intubation was 12 days. The patients with COVID-19 transferred to local hospitals during the outbreak had severe conditions and needed close monitoring. The severity of COVID-19 depends on the presence of pneumonia. High serum LDH, AST and CRP levels and low serum albumin level and lymphocyte count were found to be predictors of pneumonia. It was challenging for local hospitals to admit and treat these patients during the outbreak of COVID-19. Assessment of severity was crucial to manage a large number of patients.

Snapshot of Oxidation of Thiolate by Diiodine: Stabilization of Intermediate by NH···S Hydrogen Bonds

Ordinary thiolate (RS^-) reacts with diiodine (I₂) to afford an intermediate sulfenyl iodide (RSI) by releasing I^-; RSI is readily converted to disulfide (RSSR) by a disproportionation reaction. In the case of thiolate Ar¹S^- containing very bulky acylamino groups forming NH···S hydrogen bonds, the crystal of the intermediate, [Ar¹S-I-I]^-, was obtained under usual conditions, and the structure was determined by X-ray diffraction analysis. The results show that the intramolecular NH···S hydrogen bonds stabilized the intermediate [Ar¹S-I-I]^-, consistent with theoretical calculations.

Experience of Quatro-Therapy With Everolimus to Minimize Calcineurin Inhibitor for Kidney Transplant Recipients

BACKGROUND

This study was divided into three phases, on the occasion of the introduction of everolimus (EVR) in our hospital.

METHODS

In the first phase, a study group of six maintenance patients (three living related donors, three deceased donors) who had a history of malignant disease with less than 500 mg/day of proteinuria were enrolled; a high serum creatinine and upper limit of duration after kidney transplant operation was not considered. EVR was discontinued in four of the six patients because of side effects or worsening renal function. The second phase comprised a study group of 12 maintenance patients (12 living related donors) who were more than 5 years after kidney transplant operation with serum creatinine <3 ng/mL and proteinuria <500 mg/day. In two patients, EVR was discontinued because of a skin rash or general fatigue, but EVR was continued in 10 cases. Calcineurin inhibitor (CNI) dosage was reduced and renal function improved, and mean estimated glomerular filtration rate recovered from 42.3 mL/min to 44.8 mL/min, with no rejections occurring. In the third phase, a study group of eight de novo transplant patients who were 2 to 3 weeks after transplant operation were examined. In one case, EVR was discontinued because of proteinuria but was restarted with a stepwise increasing method after 4 months and was continued without any side effects.

RESULTS

Our study indicates that EVR was a useful drug for the maintenance of kidney transplant recipients for the optimal patients.

CONCLUSIONS

In de novo cases, EVR plus a high dose of mizoribine and low CNI protocol was a useful regimen without serious adverse effects.

Investigation and treatment of pulmonary embolism as a potential etiology may be important to improve post-resuscitation prognosis in non-shockable out-of-hospital cardiopulmonary arrest: report on an analysis of the SOS-KANTO 2012 study

Background

The prognosis of non-shockable out-of-hospital cardiac arrest is worse than that of shockable out-of-hospital cardiac arrest. We investigated the associations between the etiology and prognosis of non-shockable out-of-hospital cardiac arrest patients who experienced the return of spontaneous circulation after arriving at hospital.

Methods and Results

All subjects were extracted from the SOS-KANTO 2012 study population. The subjects were 3,031 adults: (i) who had suffered out-of-hospital cardiac arrest, (ii) for whom there were no pre-hospital data on ventricular fibrillation/pulseless ventricular tachycardia until arrival at hospital, (iii) who experienced the return of spontaneous circulation after arriving at hospital. We compared the patients' prognosis after 1 and 3 months between various etiological and presumed cardiac factors. The proportion of the favorable brain function patients that developed pulmonary embolism or incidental hypothermia was significantly higher than that of the patients with presumed cardiac factors (1 month, P < 0.0001 and P < 0.0001, respectively; 3 months, P = 0.0018 and P < 0.0001, respectively). In multiple logistic regression analysis, pulmonary embolism and incidental hypothermia were found to be significant independent prognostic factors for 1- and 3-month survival and the favorable brain function rate.

Conclusions

In patients who suffer non-shockable out-of-hospital cardiac arrest, but who experience the return of spontaneous circulation after arriving at hospital, the investigation and treatment of pulmonary embolism as a potential etiology may be important for improving post-resuscitation prognosis.

Surgical Resection of a Ruptured Pancreaticoduodenal Artery Aneurysm

Patient: Female, 71

Final Diagnosis: Rupture of a pancreaticoduodenal artery aneurysm

Symptoms: —

Medication: —

Clinical Procedure: Surgical operation

Specialty: Surgery

Synthesis and structures of soluble magnesium and zinc carboxylates containing intramolecular NH⋯O hydrogen bonds in nonpolar solvents

Magnesium and zinc carboxylates containing intramolecular NH⋯O hydrogen bonds showed a fast trans–cis isomerization in nonpolar solvents and were converted into anionic tris(carboxylate)s by the addition of an equimolar ligand.

Pre-anesthetic evaluation can play a crucial role in the determination of airway management in a child with oropharyngeal tumor

We experienced a case of a huge hemangioma occupying the oropharyngeal space in an 11-year-old child. Although urgent surgical tracheostomy under local anesthesia was suggested initially, medical interview and findings of computerized tomography and fiberoptic laryngoscopy revealed that the airway of the patient was relatively stable when she was in the semi-left decubitus position. General anesthetic induction would have had potential risks of airway obstruction. Thus, after placing the patient in the semi-left decubutus position, we chose semi-awake induction to secure the airway. With a small dose of fentanyl, we accomplished orotracheal intubation. In this report, we discuss the importance of referring to an airway management algorithm when encountering a difficult airway.

Pseudohyperkalemia occurring in a patient with chronic renal failure and polycythemia vera without severe leukocytosis or thrombocytosis

Pseudohyperkalemia is defined as a serum potassium concentration 0.4 mEq/l greater than the plasma concentration. The basis of this phenomenon is the release of intracellular potassium from platelets, leukocytes, or erythrocytes, commonly in the setting of extreme leukocytosis (> 10 x 10(4)/microl) or thrombocytosis (> 60 x 10(4)/microl). We report a case of pseudohyperkalemia in a patient with chronic renal failure and polycythemia vera without the finding of severe leukocytosis or thrombocytosis (white blood cell count 1.88 x 10(4)/microl and platelet count 37.9 x 10(4)/microl, respectively). The serum potassium concentration was 8.2 mEq/l, while the plasma potassium level was 6.4 mEq/l in a sample obtained simultaneously. The concentrations of platelet factor IV and beta-thromboglobulin, known to be markers of platelet activation, were greater than 100 ng/ml and 200 ng/ml, respectively, indicating that platelet activation may have been related to the development of pseudohyperkalemia in this patient. These findings suggest that pseudohyperkalemia should be considered when hyperkalemia is seen in a patient with chronic renal failure and myeloproliferative disorders.

Hypercalcemia in a patient with B-cell acute lymphoblastic leukemia: a role of proinflammatory cytokine

The complication of hypercalcemia is reported to occur only in 2.5-4.8% of patients with acute lymphoblastic leukemia (ALL). We herein report a 53-year-old female patient with early B-cell ALL, complicated with extreme hypercalcemia (15.2 mg/dL). Bone X-ray revealed osteolytic changes in many locations. Serum 1,25(OH)2vitaminD3 and parathyroid hormone (PTH) levels were suppressed below normal ranges on admission. The circulating parathyroid hormone-related protein (PTHrP) value was within a normal range (< 1.1 pmol/L). Serum concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and soluble IL-2 receptor were increased to 72 pg/ml, 25.3 pg/ml, and 1469 U/ml, respectively. Following the induction chemotherapy, the serum calcium level was promptly normalized accompanied with decreases in serum TNF-alpha, IL-6 and soluble IL-2 receptor values to 34 pg/ml, 6.35 pg/ml, and 737 U/ml, respectively. Serum PTHrP values remained within detectable levels. To our knowledge, this is the first case of B-cell ALL in a patient who developed hypercalcemia with elevated concentrations of TNF-alpha, IL-6, and soluble IL-2 receptor, but not related to PTHrP. High circulating proinflammatory cytokines may have contributed to development of ALL-induced osteolysis and hypercalcemia in the present case.

The dipeptide, gamma-glutamylcysteine, is recognized by the anti-glutathione antibody single chain Fv fragment 20C9

The anti-glutathione antibody scFv 20C9, which we previously isolated from a human synthetic phage antibody scFv library [Hirose, M., Hayano, T., Shirai, H., Nakamura, H., and Kikuchi, M. (1998) Protein Eng. 11, 243-248], was expressed in the E. coli pET system and purified by sequential chromatography on Ni and glutathione-conjugated affinity resins. The purified scFv 20C9 antibody was characterized for its binding affinity for several glutathione derivatives by the BIACORE system. Although GSH, GSSG, and gamma-Glu-Cys could bind to the immobilized antibody, this was not the case for Cys-Gly, l-Glu, l-Cys, l-Gly, or several other glutathione derivatives such as gamma-Glu-Ser-Gly. The results suggest that a gamma-glutamic acid and sulfur atom are important for scFv 20C9 antibody recognition of glutathione. This is the first report to indicate that an scFv antibody can recognize a region as small as a dipeptide.

Acute effects of ovariectomy on wound healing of alveolar bone after maxillary molar extraction in aged rats

Acute effects of ovariectomy on the bone wound healing processes after maxillary molar extraction in aged rats were examined by means of quantitative scanning electron microscopy (SEM), backscattered electron image (BSE) analysis and energy-dispersive X-ray (EDX) microanalysis. Six-month-old female rats underwent either sham operation or bilateral ovariectomy, and 7 days postoperatively, the maxillary first molars were extracted. On post-extraction days 7, 30 and 60, the dissected maxillary bone surfaces were examined by SEM to reveal the bone formative and resorptive areas around the extracted alveolar sockets. In addition, the resin-embedded maxillae were micromilled in the transverse direction through the extracted alveolar sockets, and the newly-formed bone mass on the buccal bone surfaces and within the extracted sockets was examined by BSE analysis. Compared with sham-operated controls, the extent of newly-formed bone mass on the buccal bone surfaces in OVX rats was significantly decreased, due to increased bone resorption. On the other hand, new bone formation within the extracted sockets was similar in the experimental groups. In EDX microanalysis of these newly-formed bone matrices, both Ca and P weight % and Ca/P molar ratio were similar in the experimental groups. Our results suggest that 1) acute estrogen deficiency induced by ovariectomy stimulates sustained bone resorption, but has less effect on bone formation, and 2) bone wound healing after maxillary molar extraction within extracted alveolar sockets is not significantly delayed by ovariectomy, but bony support by newly-formed bone mass on the maxillary bone surfaces at the buccal side of the extracted sockets is significantly decreased, due to increased bone resorption.

Stimulation of the locus coeruleus suppresses trigeminal sensorimotor function in the rat

The nucleus locus coeruleus (LC) has been implicated in the modulation of the spinal sensorimotor function. The aim of the present study was to examine the effect of electrical stimulation of the LC on sensorimotor function in the trigeminal system. The following two cases of sensorimotor behaviors mediated by the trigeminal brainstem sensory nuclear complex were examined: (1) the activity of the masseter muscle evoked by pressure on the region of the temporomandibular joint (TMJ); and (2) the activity of the digastric muscle evoked by electrical stimulation of the tooth pulp, resulting in the jaw-opening reflex. In the first case, LC stimulation at 10, 30 and 50 microA resulted in a 70%, 68% and 55% reduction in the magnitude of electromyogram (EMG) activity of the masseter muscle compared with the control (without LC stimulation), respectively. The threshold intensity for the onset of masseter EMG activity increaced to 106%, 111% and 121% of the control with 10, 30 and 50 microA LC stimulation, respectively. In the second case, EMG magnitude in response to the digastric muscle decreased to 42% of the control when 30 microA of LC stimulation was delivered. These results suggest that descending influences from the LC can act in suppression of the trigeminal sensorimotor function.

A patient with thrombotic microangiopathy accompanied by glomerular subendothelial electron dense deposits

A 50-year-old woman presented with thrombocytopenia, microangiopathic hemolytic anemia, and nephrotic syndrome. Although a high level of circulating immune complexes, mild hypocomplementemia, and the antinuclear antibody also were present, the criteria for collagen disease were not fulfilled. Renal biopsy demonstrated a typical thrombotic microangiopathy (TMA) involving glomeruli. There also were electron-dense deposits located just beneath the original glomerular basement membrane in the dilated subendothelial space, thought to be immune complexes following positive IgG, C1q and C3 staining on an immunofluorescent study. Corticosteroid therapy rapidly ameliorated her hematologic abnormalities and proteinuria and normalized the immunologic data. These findings strongly suggest that the TMA in this patient was induced by immune complex-associated mechanisms.

Impaired water excretion in a hyponatremic patient following thyroidectomy: causal role of glucocorticoid deficiency

We evaluated the causal role of glucocorticoid deficiency in the hyponatremia that developed in a 57-year-old Japanese man with hypothyroidism following the performance of a total thyroidectomy for laryngeal cancer. The plasma concentration of vasopressin (1.78 pg/ml) was not suppressed in the presence of hyponatremia (125 mEq/l). The urinary excretion of sodium was increased, and the plasma renin activity and plasma aldosterone concentration were suppressed. The infusion of hypertonic saline increased the plasma osmolality, but not the plasma concentration of vasopressin. An oral water load (20 ml/kg of body weight) did not suppress the plasma vasopressin level or induce diuresis. Pretreatment with hydrocortisone normalized the response of plasma vasopressin to the water load was well as the diuretic response during the hypothyroid state. The urinary excretion of 17-hydroxycorticosteroids was below normal in the hypothyroid state in the face of normal serum cortisol concentration. The correction of the hypothyroidism returned these abnormalities to normal. A disturbed metabolism of glucocorticoid may have been responsible for the hyponatremia and disturbance in plasma vasopressin regulation observed in this hypothyroid patient.

Bone wound healing after maxillary molar extraction in ovariectomized aged rats: quantitative backscattered electron image analysis

The processes of bone wound healing after maxillary molar extraction in ovariectomized aged rats were examined by means of quantitative backscattered electron image analysis and energy-dispersive X-ray microanalysis. Six-month-old female rats were either sham-operated or underwent bilateral ovariectomy (OVX), and 60 days postoperatively, the maxillary first molars were extracted. On post-extraction days 7, 30, and 60, the dissected and resin-embedded maxillae were micromilled in the transverse direction through the extracted alveolar sockets, and new bone formation on the buccal maxillary bone surface and within the extracted alveolar sockets was examined. In both sham-operated control and OVX rats, new bone formation was recognized on the buccal bone surface, as well as within the extracted sockets, and increased daily through to day 60. In comparison to sham-operated controls, new bone formation in OVX rats was significantly decreased both on the buccal bone surface and within the extracted sockets. Our results suggest that bone wound healing by new bone formation after maxillary molar extraction is significantly decreased in OVX-induced osteoporosis.

Altered abdominal fat distribution and its association with the serum lipid profile in non-diabetic haemodialysis patients

BACKGROUND

Disturbances of lipid and carbohydrate metabolism may be associated with the distribution of abdominal adiposity. However, little is known about the alteration of abdominal adiposity and its association with the serum lipid profile in haemodialysis patients.

METHODS

We evaluated the distribution of abdominal adiposity by using computed tomography and examined its relationship with the serum lipid profile in 92 non-diabetic haemodialysis patients and 80 control subjects with normal renal function. Since the mean body mass index (BMI) and total body fat mass were significantly lower in the haemodialysis patients than in the control subjects, the subcutaneous abdominal fat area and the visceral fat area were standardized by body mass index and compared between the haemodialysis patients and the control subjects.

RESULTS

Mean subcutaneous fat area/body mass index (SFA/BMI) was significantly lower, and mean visceral fat area/body mass index (VFA/BMI) was significantly higher in the haemodialysis patients (SFA/BMI, 2.40+/-0.12; VFA/BMI, 2.28+/-0.15) than in the control subjects (SFA/BMI, 3.75+/-0.21, P<0.01; VFA/BMI, 1.65+/-0.15, P<0.01). Consequently, visceral fat area/ subcutaneous fat area ratio was significantly higher in the haemodialysis patients (1.05+/-0.07) than in the control subjects (0.46+/-0.04, P<0.01). A scattered plot of visceral fat area relative to BMI revealed that visceral fat area was higher in the haemodialysis patients than in the control subjects at any BMI level. A simple regression analysis showed that BMI, total body fat mass, subcutaneous fat area and visceral fat area were all associated with serum triglycerides and the atherogenic index, (total cholesterol-HDL cholesterol)/HDL cholesterol. Furthermore, a multiple regression analysis indicated that the visceral fat area was the best predictor for either the atherogenic index or triglycerides among these fat components.

CONCLUSIONS

These data indicate that haemodialysis patients exhibited a visceral fat accumulation irrespective of BMI, and this shift of abdominal adiposity might be associated with disturbance of the serum lipid profile in non-diabetic haemodialysis patients.

Depressant and convulsant barbiturates both inhibit neuronal nicotinic acetylcholine receptors

Neuronal nicotinic acetylcholine receptors (neuronal nAchRs) are sensitive to many anesthetics, including barbiturates, which suggests that these receptors are potential sites for anesthetic action. Subtle changes in molecular structures of the anesthetic barbiturates can produce compounds with potent convulsant activity. Whereas R(-) isomer of 1-methyl-5-phenyl-5-propyl barbituric acid (MPPB) exerts anesthetic action, S(+)MPPB exhibits pure excitatory effects, including convulsion. 5-(2-cyclohexilidene-ethyl)-5-ethyl barbituric acid is another example of a convulsant barbiturate. We compared the effects of depressant and convulsant barbiturates on the neuronal nAchR-mediated current to determine whether inhibition of neuronal nAchRs contributes to the anesthetic action of barbiturates. Whole cell nicotine-induced currents were recorded in PC12 derived from rat pheochromocytoma, using the conventional whole cell patch clamp technique in the presence and absence of barbiturates. Both depressant and convulsant barbiturates inhibited the nicotine-induced inward current reversibly and in a dose-dependent manner when co-applied with nicotine. All barbiturates accelerated the current decay. There was no significant difference between the concentrations for 50% inhibition for MPPB isomers. There was no correlation between inhibition of ganglionic nAchRs and anesthetic effects of the barbiturates. These results strongly oppose the idea that inhibition of neuronal nAchRs contributes to the anesthetic action of barbiturates.

IMPLICATIONS

We found that both convulsant and depressant barbiturates inhibit the current mediated through ganglionic nicotinic acetylcholine receptors in PC12 cells. This finding suggests that the inhibition of neuronal nicotinic acetylcholine receptors does not contribute to the anesthetic action of barbiturates.

Comparison of the effects of convulsant and depressant barbiturate stereoisomers on AMPA-type glutamate receptors

BACKGROUND

Alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamate receptors mediate fast excitatory synaptic transmission in the central nervous system. Although barbiturates have been shown to suppress the AMPA receptor-mediated responses, it is unclear whether this effect contributes to the anesthetic action of barbiturates. The authors compared the effects of depressant [R(-)] and convulsant [S(+)] stereoisomers of 1-methyl-5-phenyl-5-propyl barbituric acid (MPPB) on the AMPA and gamma-aminobutyric acid type A (GABA(A)) receptor-mediated currents to determine if the inhibitory effects on AMPA receptors correlate to the in vivo effects of the isomers.

METHOD

The authors measured whole-cell currents in the rat cultured cortical neuron at holding potential of -60 mV. Kainate 500 microM was applied as the agonist for AMPA receptors. Thiopental (3-300 microM), R(-)-MPPB or S(+)-MPPB (100-1,000 microM) was coapplied with kainate under the condition in which the GABA(A) receptor-mediated current was blocked. Effects of MPPB isomers on the current elicited by GABA 1 microM were studied in the separate experiments.

RESULTS

Thiopental inhibited the kainate-induced current reversibly and in a dose-dependent manner, with a concentration for 50% inhibition of 49.3 microM. Both R(-)-MPPB and S(+)-MPPB inhibited the kainate-induced current with a little stereoselectivity. R(-)-MPPB was slightly but significantly more potent than S(+)-MPPB. In contrast, R(-)-MPPB enhanced but S(+)-MPPB reduced the GABA-induced current.

CONCLUSIONS

Both convulsant and depressant stereoisomers of the barbiturate inhibited the AMPA receptor-mediated current despite of their opposite effects on the central nervous system in vivo. Although thiopental exhibited a considerable inhibition of AMPA receptors, the results suggest that the inhibition of AMPA receptors contributes little to the hypnotic action of the barbiturates.

Association of the serum leptin concentration with weight loss in chronic hemodialysis patients

Circulating leptin, which is partly cleared by the kidney, has been reported to increase with chronic renal failure and thus may play a role in the weight loss of patients with chronic renal failure. We investigated the association of body weight loss with the serum leptin concentration in Japanese hemodialysis patients. The relationship between serum leptin and the body mass index (BMI) or body fat mass was compared among 181 patients undergoing hemodialysis and 185 control subjects. There was no difference in the serum leptin concentration between the hemodialysis patients (HD) and controls (C) for either the men (3.9 +/- 0.2 ng/mL for HD, n=117; 3.9 +/- 0.3 ng/mL for C, n=89; NS) or women (8.9 +/- 1.2 ng/mL for HD, n=64; 7.4 +/- 0.5 ng/mL for C, n=96; NS), whereas BMI of the hemodialysis patients was significantly lower than that of the controls for both the men (20.1 +/- 0.2 kg/m2 for HD, 22.4 +/- 0.3 kg/m2 for C, P < 0.001) and women (19.2 +/- 0.3 kg/m2 for HD, 22.0 +/- 0.4 kg/m2 for C, P < 0.001). The serum leptin/body fat mass ratio was significantly correlated with the weight change of the patients during a follow-up evaluation period of 17 months (r = -0.37, P < 0.05 for men, n=27 and r = -0.53, P < 0.005 for women, n=28), indicating the possibility that a relatively high level of serum leptin had induced weight loss in the hemodialysis patients. The serum leptin/body fat mass ratio also showed a significant inverse correlation with the duration of hemodialysis (r = -0.31, P < 0.05 for men and r = -0.49, P < 0.05 for women). A multiple regression analysis indicated that the body fat mass was significantly correlated with serum leptin concentration, whereas the fat distribution did not have any relationship with leptin. These data indicate that a high level of serum leptin relative to the body fat mass might be associated with weight loss in long-term hemodialysis patients. The serum leptin level relative to the body fat mass also seems to have been affected by the duration of hemodialysis.

Effects of ovariectomy on bone morphology in maxillae of mature rats

Postmenopausal oestrogen deficiency results in bone loss (osteoporosis) in humans and experimental animals. The loss of trabecular bone in the ovariectomized (OVX) rat provides a useful experimental model of post-menopausal osteoporosis. At 5 months after ovariectomy of 3-month-old female rats, the mid and distal femurs and maxillae were dissected and processed for quantitative backscattered electron microscopic examinations. Histomorphometric analysis of femurs in OVX rats showed significant loss in metaphyseal trabecular bone areas compared with sham-operated controls; no significant bone loss was observed in the cortical bone areas of mid-diaphyses in OVX rats. Net bone areas in the maxillae of OVX rats was similar to that of sham-operated controls. Bone structure of maxillae in OVX rats was also similar to that in controls. Our results suggest that, in this animal model of osteoporosis, prominent bone loss occurs mainly in the bone areas formed by endochondral ossification such as distal femurs, but those areas formed by intramembranous ossification such as mid-femurs and maxillae sustained less effects by OVX.

The effects of ketamine and propofol on neuronal nicotinic acetylcholine receptors and P2x purinoceptors in PC12 cells

We studied the effects of ketamine and propofol on two ligand-gated ion channels mediating fast synaptic transmission through sympathetic ganglia, neuronal nicotinic acetylcholine receptors (nAchRs), and P2X purinoceptors in a rat pheochromocytoma cell line PC12 using whole cell voltage clamp recording. Ketamine and propofol similarly inhibited the nicotine-induced inward current reversibly and dose-dependently at the membrane potential of -60 mV but had no effects on the adenosine triphosphate-induced current. Both anesthetics accelerated the current decay during agonist application, resulting in greater inhibition on the steady current than the peak current. The 50% inhibition concentration values for the steady current were lower than the clinically relevant concentrations for ketamine (2.8+/-0.6 microM) and higher than those for propofol (5.4+/-0.6 microM). Both anesthetics induced an addition of the fast component to the decay phase and an acceleration of the slow component, which suggests an open channel blockade or an enhancement of desensitization as a mechanism. The effects on closed channels seemed to be small because preincubation with the anesthetics did not significantly augment the block. Inhibition was voltage-independent at membrane potentials between -20 and -70 mV and was consistent with a noncompetitive block. Inhibition of the neuronal nAchR-mediated current may lead to the suppression of synaptic transmission in sympathetic ganglia by ketamine, but not by propofol, at the clinically relevant concentrations. However, these results are not consistent with changes in sympathetic nerve activities reported for animals or humans anesthetized with ketamine or propofol, which suggests effects from other systems, such as the central nervous system in vivo.

IMPLICATIONS

Ketamine (at smaller than clinically relevant concentrations) and propofol (at larger than clinically relevant concentrations) inhibited neuronal nicotinic acetylcholine receptor-mediated current in PC12 cells, which possess the receptors that resemble those in postganglionic sympathetic neurons. These findings are not consistent with in vivo experiments, which suggests that effects from other systems, such as the central nervous system, are of importance.

The proliferation and differentiation of neonatal epidermal melanocytes in F1 hairless mice of HR-1 x HR/De in serum-free culture

To investigate the characteristics of the proliferation and differentiation of epidermal melanocytes in F1 hairless mice of HR-1 x HR/De parents in vitro, cell suspensions of the neonatal epidermis were cultured in a serum-free medium supplemented with dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP) and/or basic fibroblast growth factor (bFGF). The differentiation of melanocytes was induced by treatment with DBcAMP. In contrast, the sustained proliferation of melanoblasts was induced by combined treatment with DBcAMP and bFGF. The melanoblasts could be subcultured in serum-free medium supplemented with the two factors in the presence of keratinocytes, but not in their absence. This is the first report of successful culture of melanoblasts and melanocytes from hairless mice; it is expected to be useful in understanding the mechanism of the development of pigmented spots in the epidermis of (HR-1 x HR/De)F1 mice, which are reported to be induced by repeated exposure to ultraviolet light B.

Bone wound healing after maxillary molar extraction in ovariectomized aged rats

We studied bone wound healing processes after maxillary molar extraction in ovariectomized (OVX) aged rats, as an experimental model of postmenopausal osteoporosis, by means of scanning electron microscopy. Six-month-old female rats were either sham-operated or bilaterally OVX; and at 60 days postoperatively, the maxillary first molars were extracted. On postextraction days 4, 7, 30 and 60, the dissected maxillae were fixed and the alveolar bone surfaces around the extracted alveolar sockets were examined. In sham-operated controls, new bone formation was recognized on the buccal-side bone surfaces on day 4 and then increased in extent daily through day 60 mainly on the buccal and mesial sides. On day 60, the extracted sockets were filled with new bone mass and the surrounding alveolar bone surfaces had become smooth, indicating decreased bone metabolism. Bone resorption was prominent throughout the bone surfaces around and within the extracted sockets, increased in extent through day 7, but had decreased by day 60. In comparison to sham-operated controls, new bone formation in OVX rats was slightly increased in the early phase but subsequently showed a marked decrease. Bone resorption in OVX rats was greatly stimulated and was comparatively long-lasting. These results suggest that, under the present experimental conditions, in bone wound healing after maxillary molar extraction, (i) ovariectomy stimulates sustained bone resorption and (ii) bone formation and resorption both take place at specific sites on alveolar bone surfaces.

Differential effects of thiopental on neuronal nicotinic acetylcholine receptors and P2X purinergic receptors in PC12 cells

BACKGROUND

PC12 cells, derived from rat pheochromocytoma, express neuronal nicotinic acetylcholine receptors (nAchRs) and P2X purinergic receptors, both of which resemble the receptors in postganglionic sympathetic neurons. The former is the established and the latter is the putative receptor to mediate fast synaptic transmission. The authors investigated effects of thiopental on these two ligand-gated ion channels.

METHODS

Whole cell currents were recorded in PC12 cells without treatment of nerve growth factor, using conventional whole cell patch clamp technique. Nicotine or adenosine triphosphate (ATP) 30 microM was applied for 4-5 s in the absence or presence of thiopental 3-300 microM.

RESULTS

Nicotine induced the rapidly decaying inward current at -60 mV, which exhibited the characteristics of the neuronal nAchR-mediated current. Thiopental inhibited the nicotine-induced inward current and accelerated the current decay in a dose-dependent manner, resulting in the greater effects on the steady current than the peak current. IC50s for the peak and steady current were 56.7 and 7.4 microM, when the anesthetic was coapplied with nicotine. Thiopental's inhibition was not associated with a change in the reversal potential and was voltage-independent at membrane potential of -30 to -70 mV. Most of thiopental's effects seemed to require channel opening. In contrast to the nicotine-induced current, thiopental had little effect on the current elicited by ATP.

CONCLUSIONS

Thiopental, whose reported EC50 for general anesthesia is 25 microM, inhibited the neuronal nAchR-mediated current but not the P2X receptor-mediated response in PC12 cells at clinically relevant concentrations. Inhibition may result in suppression of synaptic transmission in sympathetic ganglia.

Acquired resistance to rechallenge injury with uranyl acetate in LLC-PK1 cells

This study was conducted to determine whether cultured renal cells exposed to previous uranium injury would be resistant to subsequent insult, and if so, the mechanisms for this resistance. The addition of a toxic dose of uranyl acetate (UA) (1 X 10(-3) mol/L) for 48 hours to the culture medium significantly enhanced the release of lactate dehydrogenase (LDH) from LLC-PK1 cells, expressed as LDH activity in the medium corrected by protein content of the cells, compared with control conditions (31.5 +/- 3.6 vs 5.5 +/- 0.6 Wroblewski unit/microg protein, p < 0.01). Pretreatment with a toxic dose of UA (1 x 10(-3) mol/L for 24 hours) or heat stress (42 degrees C for 30 minutes) significantly lessened the extent of increase in LDH after exposure to toxic doses of UA for 48 hours (15.2 +/- 1.4 and 7.6 +/- 0.6 Wroblewski unit/microg protein, respectively). Pretreatment with a nontoxic dose of UA (3 x 10(-4) mol/L for 24 hours) had no effect on the release of LDH after a toxic dose of UA treatment (38.6 +/- 7.0 Wroblewski unit/microg protein). Quercetin (100 microm ) and staurosporine (0.1 microg/ml), both known to inhibit the development of thermotolerance, hindered acquisition of the resistance to rechallenge with UA (42.5 +/- 1.1 and 38.9 +/- 1.8 Wroblewski unit/microg protein, respectively). Quercetin did not modify the UA-induced increase in the release of LDH in cells not pretreated with UA or heat stress. It follows from these findings that LLC-PK1 cells previously exposed to a toxic dose of UA are resistant to rechallenged insult and that mechanisms similar to those for thermotolerance might contribute to this acquired resistances.