Three-dimensional imaging of mitral and tricuspid annuli for total artificial heart implantation

The establishment of a method to clarify the three-dimensional interrelations among the mitral annulus, tricuspid annulus, ascending aorta, and main pulmonary artery, which constitute the interface between the human and total artificial heart (TAH), is essential to the design of the TAH. In a previous study based on transverse magnetic resonance (MR) images of a live human heart, reconstructed images of mitral and tricuspid annuli were found to be deformed. The present study of cadaver and beating hearts revealed that the optimal conditions for atrioventricular annular reconstruction of a beating heart with electrocardiogram-gated MR imaging include use of four-chamber imaging, 5 mm slice thickness, and a slice interval ranging from 5 to 7 mm. Under these conditions, the mitral and tricuspid annuli of 3 beating hearts were reconstructed successfully. It was recognized that during the systolic phase the mitral and tricuspid annuli move anteriorly, leftward and downward, and that in late systole the right lateral margin of the tricuspid annulus is close to the sternum.     

Two cases of exercise-induced acute renal failure with idiopathic renal hypouricemia

Acute renal failure without oliguria developed in a 25-year-old male and a 19-year-old male after exercise. Marked hypouricemia became apparent during improvement of their renal function. Increased excretion of uric acid into the urine, increased fractional excretion of uric acid(clearance ratio of uric acid against creatinine), and normal concentration of plasma xanthine and hypoxanthine were observed in both cases. Probenecid and pyrazinamide loading test suggesting decreased reabsorption of uric acid in the proximal convoluted tubules revealed that presecretory reabsorption defect of uric acid resulted in the hypouricemia in both cases. These two cases were diagnosed as having idiopathic renal hypouricemia.     

Early and frequent development of ocular hypertension in children with nephrotic syndrome

Background

Prednisolone, the first-line treatment for children with nephrotic syndrome, causes severe side effects. One of these side effects is ocular hypertension, which can result in severe and permanent visual disturbance. However, the exact prevalence, severity and timing of development of ocular hypertension have yet to be fully explored in this pediatric patient group.

Methods

In this retrospective cohort study, children with nephrotic syndrome treated with prednisolone for their first episode were analyzed. Intraocular pressure was screened with an iCare® tonometer and confirmed with Goldmann applanation tonometry before the initiation of prednisolone treatment and at 1 and 4 weeks thereafter.

Results

A total of 26 children with nephrotic syndrome were included in this study, of whom eight (30.8 %) required treatment with eye drops for ocular hypertension. The median time interval between the diagnosis of ocular hypertension and start of treatment was 9 (range 5–31) days. At relapse of nephrotic syndrome, all children who had undergone treatment for ocular hypertension in their first episode again required treatment for ocular hypertension.

Conclusions

Routine ophthalmologic examination should be conducted from the early phase after the start of prednisolone treatment. In addition, children with episodes of ocular hypertension may be at greater risk of its reappearance with relapse of the nephrotic syndrome.     

Radiological predictive factors on preoperative multimodality imaging are related to Oncotype DX recurrence score in estrogen-positive/human epidermal growth factor receptor 2-negative invasive breast cancer: a cross-sectional study

Annals of Nuclear Medicine - The Oncotype DX (ODX) estimates the 10-year risk of metastasis or recurrence of breast cancer and indicates whether chemotherapy is likely to be effective; however, the...     

Orthostatic hypotension in elderly persons during passive standing: a comparison with young persons

BACKGROUND: The present study was aimed at clarifying the mechanism of orthostatic hypotension (OH) that occurs in elderly persons and at investigating assisting methods to prevent OH by evaluating changes in autonomic nervous system (ANS) activity and cerebral circulation of elderly persons when engaged in passive standing. METHODS: Eight elderly volunteers and 9 young volunteers gave informed consent to participate in the study. Two experimental conditions were established: (i) "active standing," in which the subjects stood on their own with guidance from an assistant, and (ii) "passive standing," in which the subjects were placed in a standing position completely by an assistant. ANS was determined before and after standing by measuring the heart rate variability. The reaction of the ANS was evaluated on the basis of low-frequency power (LF: 0.05--0.15 Hz) and high-frequency power (HF: 0.15--0.4 Hz), which were separated from the R-R interval data by power spectral analysis using the fast Fourier transformation. Cerebral perfusion was measured over the right frontal region using a near-infrared spectroscopy cerebral oxygen monitor. RESULTS: The main findings were: (i) Transient decreases in blood pressure occurred immediately after standing in both the young and elderly subjects. (ii) The LF:HF ratio increased significantly ( p <.05) immediately after active standing in the young subjects, whereas this ratio increased in the elderly subjects after some delay. (iii) The LF:HF ratio increased significantly ( p <.01) immediately after passive standing in the young subjects, whereas this ratio decreased significantly ( p <.05) in the elderly subjects. (iv) In the elderly subjects, the total hemoglobin (HbT) and oxyhemoglobin showed the greatest decrease during the 15-second period after standing. The maximum changes in the HbT with passive standing differed significantly ( p <.01) from those observed during active standing. CONCLUSIONS: Our findings emphasize the need to devise bioengineered means that allow elderly persons to exert themselves, to maintain or improve muscle contractility and ANS function, while providing minimum assistance for standing.     

Multiple calcifications within the parotid gland of patients with Sjögren's syndrome

PurposeThe purpose of this study was to investigate computed tomography (CT) and clinical features relating to calcifications within the parotid gland of patients with Sjögren's syndrome (SS).MethodsData from 30 patients with SS who had been examined by CT were extracted from our radiological information database accumulated from 2001 to 2011, and their CT images were reread carefully. Of these patients, 14 (all female; age range 20–95 years; mean age 61.4 years) with calcifications within the parotid gland were retrospectively investigated with CT findings. The relationship between calcification occurrence and clinical symptoms including parotid swelling and/or saliva colic was investigated. The degree of destruction of the parotid gland on CT images was also evaluated.ResultsAll calcifications of 14 patients were located within the parotid gland, not in the parotid duct. CT images of all calcifications showed small and regular round shapes. Multiple occurrences of calcifications were recognized in 10 patients, and a solitary occurrence was seen in 4 patients. Seven patients had bilateral calcifications. There was little relationship between the occurrence of calcifications and clinical symptoms, and the severity of destruction of the parotid gland.ConclusionThe presented CT and clinical features would be peculiar to SS because too many patients lacked the typical features of sialoliths within the parotid gland.     

Reproducibility of three-dimensional coordinate systems based on craniofacial landmarks

Abstract Objectives: To propose a method for evaluating the reproducibility of anatomical coordinate systems based on craniofacial skeletal landmarks and to tentatively evaluate four systems created on preoperative cone-beam computed tomography (CBCT) data obtained from mandibular prognathism patients in order to confirm the utility for actual patients' data. Materials and Methods: In three-dimensional images of 10 patients obtained by a CBCT with a large field of view, six dentists set four coordinate systems that were created in different ways, twice by plotting some landmarks situated in the superior portion of the maxillofacial skeletons. The 95% confidence ellipse of six objective landmarks related to the jaw and teeth (upper incisor, left upper first molar, lower incisor, left lower first molar, menton, and left gonion) were three-dimensionally drawn for each coordinate system. The ellipsoid volume was calculated to evaluate the reproducibility of the coordinate systems. Results: The reproducibility could be evaluated for each coordinate system using the method proposed. The coordinate systems that were created by landmarks situated at greater distances from each other showed relatively small ellipsoid volume in comparison to those with shorter distances between landmarks. Conclusion: Anatomical coordinate systems with larger distances between the landmarks used were stable when landmarks related to the jaw and teeth were assigned as objective landmarks. The method proposed here was effective in terms of the reproducibility evaluation of a coordinate system.     

Non-invasive measurement in intracranial pressure and analysis of the pulse waveform

Non-invasive measurement of the intracranial pressure (ICP) via the anterior fontanelle by using an applanation transducer has been performed. Recently, a new fontanometer using an applanation transducer has been developed in our department by improving the conventional Statham tranducer, P-50 which is currently accepted for its high reliability. In this study, by analysing patterns of the ICP pulse waves obtained from this new fontanometer, its clinical evaluation has been made in 27 neonates and infants in intracranial pathologies. Analysing the ICP waveforms, the first peak (P₁) was divided by the following second peak (P₂) and the changes in P₁/P₂ were examined. A differential amplifier, a dP/dt detector, was also used to make it easier to identify the turning point on the pulse waves.

The results obtained demonstrated that the waveforms of ICP in neonates as well as infants are influenced by not only the intracranial constituents but compliance of the container such as the scalp, cranium and the meninges.