Two different pathways of glomerular enlargement in adults with focal and segmental glomerulosclerosis: a morphometric study.

The renal biopsy specimens obtained from 15 adults with focal and segmental glomerulosclerosis (FSGS) and 15 adults with minimal change nephrotic syndrome (MCNS) were morphometrically analyzed using light and electron microscopy. Moreover, initial biopsy specimens obtained from 10 adults who were diagnosed as MCNS and developed FSGS, based on repeat biopsy findings ('MCNS'-FSGS), were also analyzed using electron microscopy. After comparing the actual values between the groups of FSGS and MCNS, the mean glomerular volume, the capillary volume per a glomerulus, the capillary filtration surface per a glomerulus, and the capillary diameter (Cap-D) were all larger in the FSGS group than in the MCNS group. In regard to the morphological values in the 'MCNS'-FSGS group, both values of the surface density of the capillary filtering surface and the capillary diameter at the first biopsy specimens as well as those in the FSGS group were higher than those in the MCNS group. When analyzing the structural parameters, in the FSGS series, we found a high association of the percentage of obsolescent glomeruli (%SG) with the mean glomerular volume, the capillary volume per a glomerulus, the capillary filtering surface per a glomerulus and the capillary length per a glomerulus, however we failed to demonstrate the correlation between the %SG and the Cap-D. Thus, the glomerular structure in the 'MCNS'-FSGS patients, even at the first renal biopsy, resembled that in FSGS, suggesting FSGS to be a distinct entity from MCNS. These data indicate that the enlargement of the capillary volume, resulting from the widening of the capillaries, was the initial structural event for adults with FSGS, while the elongation of the capillaries appeared to reflect some compensatory process for the decrease in the functioning nephron.

Dependence of transverse relaxation time T2 of biologic tissues on the interpulse delay time in Carr-Purcell-Meiboom-Gill (CPMG) measurements.

To determine the transverse relaxation time (T2) of biological tissues in nuclear magnetic resonance measurements, the Carr-Purcell-Meiboom-Gill (CPMG) method has been recommended to avoid the effect of external magnetic field inhomogeneity on T2 values. However, a dependence of T2 on the interpulse delay time (IPDT) in the CPMG measurements has been shown for biological tissues. The present study examined the dependence of the T2 on IPDT for muscle, lung (passively collapsed or degassed), and brain tissues. It was found that the CPMG T2 of the lung was strongly dependent upon the IPDT, in contrast to muscle and brain tissues. The IPDT dependence of the CPMG T2 for lung tissue, which was lessened by degassing, was affected by the magnetic field inhomogeneity due to air-tissue interfaces, but not by the spin-locking effect, since the T2 measured by the Carr-Purcell-Freeman-Hill (CPFH) method did not show this dependence. These results should aid in the evaluation of T2 values for biological tissues measured under various conditions and by different techniques.

Analysis of factors causing signal loss in the measurement of lung tissue water by nuclear magnetic resonance.

The water content of lung, brain, and muscle tissue was measured by nuclear magnetic resonance (NMR) and compared with gravimetric determinations. The NMR signal intensity of water was measured by a single 90 degree pulse and by a spin-echo sequence. The absolute water content was determined by the difference in the sample's weight before and after desiccation. The NMR detectable water in each tissue was expressed as a percentage of the signal intensity for an equal weight of distilled water. Using the single pulse measurement, 67% of the gravimetrically-measured water was detected in collapsed lung samples (consisting of about 47% retained air), in contrast to 96% for brain and 98% for muscle. For degassed lung samples, the NMR detectability of water increased to 87% with the single pulse measurement and to 90% with the spin-echo measurement, but the values remained significantly less than those of brain or muscle. Factors that caused the NMR signal loss of 33% in collapsed lung samples were: air-tissue interfaces (20%), microscopic field inhomogeneity (3%), and a water component with an extremely short magnetization decay time constant (10%).

Nuclear magnetic resonance study of lung water compartments in the rat.

Nuclear magnetic resonance transverse relaxation time (T2) was previously measured in studies of lung water. The T2 decay curves for peripheral lung tissue were found to be multiexponential with two T2 components: T2 fast (T2f) and T2 slow (T2s). This behavior was explained by the compartmentalization of water, in which the protons of water are restricted and do not undergo rapid exchange between the compartments. We investigated the origin of the water for these T2 components using excised rat lungs. The effect of magnetic field inhomogeneity due to air-tissue interfaces was examined by degassing some lungs. The contribution of intravascular water was examined by perfusing the lungs with oil or NaCl solutions. Degassing produced a greater increase in the T2f than the T2s component, indicating that the water in the alveolar walls exposed to air spaces contributed to the T2f. Perfusion with oil decreased the T2s, indicating that intravascular water contributed to the T2s component. The effects of intravascular osmotic pressure on the T2f and T2s components suggest that intracellular water is related to the T2f component.

Magnetic resonance relaxation times in acute hydrostatic pulmonary edema induced by noradrenaline in rats.

Models of pulmonary edema have been used to study the nuclear magnetic resonance (NMR) characteristics of lung water. Several investigators have measured changes in the relaxation times in the permeability type of pulmonary edema, but relatively few have measured relaxation times in the hydrostatic type of pulmonary edema. In this study we determined the characteristics of NMR relaxation times T1, T2 (Hahn spin-echo decay) and water content in acute hydrostatic pulmonary edema induced by noradrenaline administration in rats. Changes in T1 and T2 showed a significant prolongation in hydrostatic pulmonary edema. T2 decay curves for peripheral lung tissues were multiexponential and fit two components [T2 fast (T2f) and T2 slow (T2s)]. With two-component T2 analysis, T2s showed greater prolongation than did T2f. The increase in T2s was significantly correlated with an increase in water content, but the increase in the T2f value was not correlated with water content or with a change in T2s. The T2s component, which likely reflected changes in interstitial water, was more closely related than the T2f component to an increase in water content in hydrostatic pulmonary edema. Results suggested that regional changes in hydrostatic pulmonary edema may be evaluated by multicomponent T2 analysis.

[Nuclear magnetic resonance relaxation times for human lung cancer and lung tissues].

We investigated the nuclear magnetic resonance (NMR) relaxation times, T1 and T2, for lung cancer tissue, and other samples of lung tissue obtained from surgical specimens. The samples were nine squamous cell carcinoma, five necrotic squamous cell carcinoma, 15 adenocarcinoma, two benign mesothelioma, and 13 fibrotic lungs. The relaxation times were measured with a 90 MHz NMR spectrometer and the results were correlated with histological changes. The values of T1 and T2 for squamous cell carcinoma and mesothelioma were significantly longer than those of adenocarcinoma and fibrotic lung tissue. There were no significant differences in values of T1 and T2 between adenocarcinoma and lung tissue. The values of T1 and T2 for benign mesothelioma were similar to those of squamous cell carcinoma, which suggested that increases in T1 and T2 are not specific to malignant tissues.

Tissue characterization of pneumonia and irradiated rat lungs with magnetic resonance relaxation times.

To interpret the MRI signal intensities, the T1 and T2 values were determined in vitro for rat lungs with radiation pneumonitis, fibrosis or pneumonia, and also for muscle and fat tissues. The transverse magnetization decays mentioned above exhibited two components, a T2 fast (T2f) and a T2 slow (T2s) component. Lungs from rats with pneumonia had significantly longer T2f and T2s values than lungs from rats with radiation pneumonitis and fibrosis. The T2f and T2s values for a "pneumonia lung" were not significantly different from those of muscle. The measured values of T2f and T2s suggested that radiation pneumonitis and fibrosis likely exhibit lower signal intensities than do muscle and that a "pneumonia lung" likely exhibits a similar signal intensity to that of muscle on T2-weighted MR images.

[Proton magnetic resonance spectroscopy (1H-MRS) of peripheral blood lymphocytes in patients with sarcoidosis and interstitial pneumonitis].

We recently developed a method of proton magnetic resonance spectroscopy (1H-MRS) to measure the 1H-MR spectra of peripheral blood lymphocytes (PBL) using only 10(7) cells. We investigated the clinical feasibility of this method for evaluating disease activities in sarcoidosis and interstitial pneumonitis. PBL was separated from 10 ml of venous blood by differential centrifugation with Ficoll-Conray. Using a 90 MHz MR spectrometer (EX90, JEOL), the spectrum was obtained with 4000 times accumulation of 1H signals by single 70 degree pulses at 37 degrees C under spinning. Water signal was suppressed with the homo-gated decoupling sequence. The spectra were analyzed with Gaussian curve fitting. The spectra of patients with active disease showed significant increases in peak heights for (CH2)n and CH3 peaks compared with the control. The peak heights decreased after improvement of disease states. The changes in 1H-MR spectra suggested activation of PBL in patients with sarcoidosis and interstitial pneumonitis, since similar changes have been shown for cells activated with mitogens. Our preliminary results indicate that 1H-MRS may be useful to evaluate activation of PBL in sarcoidosis and interstitial pneumonitis.

[Adrenal catecholamine releases during hypotension with continuous administration of calcium entry blockers and nitroglycerin].

We investigated the effect of nicardipine and diltiazem on adrenal catecholamine releases, and compared it with the effect of nitroglycerin in dogs. A 35% reduction in mean arterial pressure was achieved and maintained for 45 minutes. The dogs were observed until 60 minutes after the discontinuation of drug infusions. Adrenal catecholamine releases increased during hypotension with continuous administration of nicardipine, diltiazem and nitroglycerin, but they showed no significant differences between each drug. There was no more increase in adrenal catecholamine releases in spite of additional nicardipine administration. These results suggest that Ca2+ antagonist such as nicardipine directly inhibits the catecholamine releases from the adrenal glands.

Quantification of water content in biological tissues by proton nuclear magnetic resonance.

We have made quantitative measurements of water content in biological tissue using proton nuclear magnetic resonance (NMR). We evaluated the factors which affect the NMR signal intensity measurements in order to quantify the absolute water content of the tissue. It can be said that there is an optimum sample length to achieve the absolute value of water content using NMR. The integrated NMR water signal intensity was determined in the frequency domain. The absolute water content was measured gravimetrically. The NMR detectable water in brain and lung tissue was determined using the signal intensity of the analyzed tissue compared with the signal intensity for the same weight of distilled water. The NMR detectable water was 99% by weight for brain and 60% by weight for peripheral lung tissue. The NMR detectability of water in biological tissues varied for different tissues.

T2 of endotoxin lung injury with and without methylprednisolone treatment.

NMR relaxation times (T1 and T2) and the water content (WC) of in vitro rat lungs were measured during the course of endotoxin lung injury in rats. Measurements of normal lungs, untreated endotoxin-injured lungs, and endotoxin-injured lungs treated with methylprednisolone (MPSL) were compared. The untreated endotoxin lungs showed prolongation of the fast and slow T2 components (T2f and T2s), but no significant changes in T1 or water content. Also, there was no correlation between 1/WC and relaxation rates or between T1 and T2. MPSL treatment prevented T2f and T2s prolongation; however, the duration of MPSL effectiveness was limited. Animals which were treated with MPSL more than 7 h prior to measurements showed T2 prolongation. This study indicates that NMR relaxation times, particularly T2, can be useful in evaluating lung injuries and their treatments.

A 1-year time course study of the relaxation times and histology for irradiated rat lungs.

To investigate the NMR relaxation times for irradiated rat lung tissue, we measured T1 and T2 at 11 different times during the injury's 1-year time course. A biexponential analysis of T2 was used to determine T2 fast (T2f) and T2 slow (T2s). In addition, we measured water content and correlated changes in the relaxation times with pathological changes. The correlation indicates the following: (1) Shortly after irradiation, the biexponential T2 decay for 1/3 of the samples became monoexponential and there were no noticeable pathological changes observed using light microscopy. (2) During radiation pneumonitis, T2f and T2s were prolonged. This accompanied acute edematous changes and inflammatory cell infiltration. (3) Finally, during radiation fibrosis T1 shortened and collagen increased. We observed no significant correlation between relaxation time changes and water content changes throughout the 1-year time course.

Suppression of water shift into intracellular space by TA-3090 (calcium entry blocker) measured with NMR.

In order to clarify the effects of TA-3090 (calcium entry blocker) on the suppression of water after ischaemic events, 16 measurements of T2f were continuously performed on brain biopsy (for 2-60 min) obtained from treated and control Wistar rats. The time constant (k) and NMR parameters (T2f,(O) delta T2f, T2fmax(T2f(O) + delta T2f) were obtained from 16 values of T2f. The values of k in Wistar rats treated with intravenously administrated TA-3090 (0.5 mg/kg) were significantly prolonged as compared to that of control. There were no significant differences of maximum prolongation of T2f(T2fmax(T2f(O) + delta T2f) among three groups. Since the prolongation of T2f after biopsy reflects the water shift from extra to intracellular space, the increments of time constant indicates that TA-3090 suppresses the water shift into intracellular space. Our present results suggest that TA-3090 prevents some processes involved in irreversible cell damage and suppresses the cytotoxic brain oedema in the incomplete ischaemic area where non-competitive calcium channel is inactive.

[The effect of nitroglycerin ointment on cardiovascular functions in hypertensive patients during emergence from anesthesia].

The present study was designed to investigate the effect of nitroglycerin (TNG) ointment to attenuate the cardiovascular response of hypertensive patients during emergence from anesthesia compared with the effects of TNG infusion and nifedipine instillation in the nose. In addition, plasma TNG concentration was measured in the TNG ointment group and TNG infusion group. TNG 30 mg in ointment reduced the arterial pressure during extubation without producing hypotension and tachycardia. There was no significant difference in plasma TNG concentration between TNG ointment group and TNG infusion group each receiving 0.3 micrograms.kg-1.min-1. The study suggests that TNG ointment is useful for regulation of arterial pressure in hypertensive patients during emergence from anesthesia.

[Graves' disease complicated with systemic lupus erythematosus (SLE): a case report].

A 25 year old man had been subjected to subtotal thyroidectomy under the diagnosis of Graves' disease. About a year later the patient developed systemic lupus erythematosus (SLE). Reports on cases of Graves' disease complicated with SLE have barely been observed so far. Consequently, the authors reckoned, with reference to the other literatures on the subject, our case worth reporting.

Acute and repair stage characteristics of magnetic resonance relaxation times in oxygen-induced pulmonary edema.

Proton magnetic relaxation times, T1 and T2, were determined for rat lungs exposed to 80% oxygen for a duration of 2 weeks. The transverse magnetization decay curve of the lung tissue was multiexponential. A linear combination of two decay curves with different T2 values fits the multiexponential decay suggesting that there are at least two different components of tissue water in the lung. Remarkable prolongation of T1 and T2 was demonstrated as lung injuries progressed in the acute stage of pulmonary edema. Both 1/T1 and 1/T2 were significantly correlated with 1/water content of the lung tissue. In the repair stage, T1 and T2 were significantly shortened. Shortening coincided with the spontaneous resolution of pulmonary edema. Relaxation rates showed no significant correlation with 1/water content in this stage. These results indicate that the physical state of water in the tissue is affected not only by the water content but also by the derangement of macromolecules in pulmonary edema. T2 was more sensitive than T1 for detecting pulmonary damage.

Lung cancer: differentiation of tumor, necrosis, and atelectasis by means of T1 and T2 values measured in vitro.

In vitro measurements of T1 and T2 values were performed in surgical specimens from 15 patients with lung cancer. Correlation between histologic results and measured values revealed that different pathologic tissues can be characterized by means of T1 and T2 values. The transverse magnetization decay curve of the lung tissue was multiexponential, which can be explained by two different relaxation times, fast T2 and slow T2. The signal intensity of pathologic lung tissues at different pulse sequences was simulated on a signal intensity gradient graph based on measured values of T1, fast T2, slow T2, and water content. The results showed that T2-weighted sequences were more valuable in discriminating viable lung cancer from necrotic tumor and collapsed lung lesions.