NMR relaxation characteristics of rubidium-87 in perfused rat salivary glands

Rubidium is a good substitute for potassium in many biological systems, and it has been suggested that rubidium-87 nuclear magnetic resonance (87Rb-NMR) spectroscopy could be used to measure K+ fluxes across membranes in intact tissues. To evaluate this possibility, isolated rat mandibular salivary glands were perfused with solutions containing Rb+ in place of K+. The 87Rb signals arising from the intra- and extracellular compartments were first separated by spectral subtraction and then subjected to line-shape analysis. The narrow extracellular signal was a single Lorentzian (line-width 156 Hz), whereas the broader intracellular signal consisted of two Lorentzian components (ca. 530 and 3080 Hz). Double-quantum filtering of the 87Rb signal from the glands revealed two components of transverse relaxation in antiphase (rate constants 1.8 and 13.3 ms-1), showing the probable involvement of quadrupolar interactions in the relaxation of intracellular Rb+. We conclude, therefore, that both line-shape analysis and double-quantum filtering could provide a basis for the measurement of unidirectional K+ fluxes in intact tissues.

Dose effects of cholecystokinin and acetylcholine on phosphorus compounds and secretory responses in isolated perfused pancreas of rat

Phosphorus nuclear magnetic resonance (31P NMR) spectroscopy was used to study energy supply for protein secretion in the isolated perfused rat pancreas. Stimulation with cholecystokinin (CCK-8) increased fluid secretion and protein output. With 10pM of CCK-8, the tissue contents of ATP, inorganic phosphate (Pi), and creatine phosphate (PCr) remained unchanged. With 100pM of CCK-8, which induced the maximum response in fluid secretion and protein output, Pi increased slightly, ATP and PCr remained almost unchanged. A high dose of CCK-8 (1 nM) suppressed the fluid and protein secretory rates, decreased ATP, and increased Pi significantly, but PCr showed a tendency of increase. Significant changes in ATP and Pi occurred on withdrawal of CCK-8 (1 nM), suggesting activation of ATP hydrolysis for recovery from secretory suppression. During stimulation with 0.1, 0.3, and 3.0 microM of acetylcholine, the similar dose-dependent response was observed in the secretion and the phosphorus metabolism. The present study demonstrated that cytosolic energy metabolism for secretory responses in the pancreas is low and the Lohmann reaction showed less contribution than in the salivary gland. The findings suggest that the energy supply for protein secretion may be cytosolic diffusion of ATP and that the Lohmann reaction system may contribute to synthesis and storing of secretory protein at resting state.

High-resolution magnetic resonance imaging of the human temporal bone

A magnetic resonance imaging (MRI) system (Hitachi, Naka, Japan) with a superconductive magnet running at 2.11 T was used to obtain 2-mm-thick slices of fixed, decalcified and celloidin-embedded human temporal bone. The temporal bone was then sectioned and stained for routine histological evaluation. Both the MR images and the histological sections were in the mid-modiolar slice plane, and comparable images and sections were analyzed to confirm the identity of the inner-ear structures visualized on the MR images. The cochlear duct, scala tympani, scala vestibuli and basement membrane of all three cochlear turns were clearly imaged on MRI. In addition, the vestibule and three semicircular ducts were also clearly seen. This study raises the possibility of some day using MRI for the diagnosis of inner-ear diseases.

Water permeability of acinar cell membranes in the isolated perfused rabbit mandibular salivary gland

1. The diffusive water permeability of epithelial cell membranes in the perfused rabbit mandibular salivary gland was measured at 37 degrees C by a 1H nuclear magnetic resonance relaxation method using an extracellular relaxation reagent, gadolinium diethylenetriaminepentaacetic acid (Gd(DTPA)). 2. In glands perfused with a HEPES-buffered solution containing 10 mmol l-1 Gd(DTPA), the spin-lattice (T1) relaxation of the water protons showed two exponential components. The water compartment responsible for the slower component corresponded in magnitude to 71 +/- 5% of the wet weight of the gland, and was attributed to the exchangeable intracellular water of the acinar cells. 3. The rate constant for water efflux from the cells was estimated to be 4.1 +/- 0.1 s-1 which would be consistent with a diffusive membrane permeability (Pd) of approximately 3 x 10(-3) cm s-1. Stimulation with acetylcholine (10(-6) mol l-1) did not cause any detectable change in membrane water permeability. 4. Since the basolateral membrane probably provides the main pathway for water efflux, the osmotic water permeability of this barrier (expressed per gland) was estimated to be less than 6.2 cm3 s-1. This would be insufficient to account for the generation of a near-isosmotic fluid at the flow rates observed during secretion, and suggests that a substantial fraction of the flow of water occurs via a paracellular route.

Sodium-23 MR imaging of the kidney in guinea pig at 2.1 T, following arterial, venous, and ureteral ligation

In vivo 23Na magnetic resonance images of guinea pig kidney were obtained at 2.1 T using a spin-echo sequence with an echo time of 19 ms. The intact kidney showed a very strong signal intensity in the sodium image. The signal intensity of the kidney decreased to 55% after ligation of the renal artery together with the vein and the ureter. The total sodium content in the excised kidney after arterial occlusion, measured by flame photometry, was 24% higher than that in the intact kidney. The transverse relaxation time (T2) of the extracellular sodium in the isolated kidney decreased to one-third of that in the intact kidney. This shortening of T2 may be partly responsible for the decrease in the 23Na signal intensity from the kidney after arterial occlusion.

[Distal aneurysm of posterior inferior cerebellar artery: report of two cases--pitfall in diagnosis]

Two cases treating aneurysms of the distal PICA were reported, and 36 cases with 39 aneurysms in the literatures in Japan were reviewed concerning the distribution of aneurysms and their findings on CT. Case 1; a 68-year-old female suffered from sudden onset of severe headache and nausea. On admission, it was found she was lethargic. However, her consciousness deteriorated down to semicoma with tetraparetic condition soon after. CT revealed subarachnoid hemorrhage in the basal, quadrigeminal and supravermian cisterns and blood clots in the entire ventricle. Cerebral angiography demonstrated an aneurysm located at the distal segment of the left PICA. She was initially treated conservatively because of being in Hunt and Kosnik Grade 5, and then, 3 weeks after onset, suboccipital craniectomy was performed and the aneurysm was clipped successfully. Case 2; a 60-year-old, female, suddenly experienced severe suboccipitalgia and vomiting. CT revealed subarachnoid hemorrhage in the entire subarachnoid space and intraventricular hemorrhages in the 4th, 3rd and lateral ventricles. Subsequently cerebral angiography was performed and left VAG demonstrated an aneurysm at the left A2-A3 junction. She underwent bifrontal craniotomy and the aneurysm was clipped via the interhemispheric approach. Her postoperative course was uneventful. Postoperative left CAG showed successful clipping of the aneurysm. However, left VAG suggested an aneurysm-like shadow in the right PICA. Right BAG carried out one week later demonstrated an aneurysm at the distal segment of the right PICA. This aneurysm was then clipped successfully under suboccipital craniectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Purification of the pyocin S2 complex from Pseudomonas aeruginosa PAO1: analysis of DNase activity

Pyocin S2 purified from mitomycin C-induced lysates of Pseudomonas aeruginosa strain PAO1 has been shown to consist of a complex of two proteins. Further analysis of the purified S2 complex revealed that the 74 kd S2 pyocin demonstrates DNase activity which can be blocked by S2-specific antisera. Chromosomal DNA from pyocin sensitive cells treated with the pyocin S2 complex in vitro did not show any degradation, suggesting that the 10 kd protein inhibits the DNase activity of the S2 protein. These results suggest an alternative mechanism for the toxicity associated with the S2 pyocin.

Spinal cord glioblastoma multiforme with intracranial dissemination--case report

A case of spinal cord glioblastoma multiforme with intracranial dissemination is reported. A 23-year-old female was admitted to a local hospital complaining of lumbago. Myelography revealed an intramedullary thoracic tumor. The tumor was partially removed through a laminectomy at Th11-L1. The histological diagnosis was glioblastoma multiforme, and focal irradiation (total 50 Gy) was given. Eight months after the operation, symptoms of increased intracranial pressure appeared. Computed tomographic (CT) scans showed marked hydrocephalus, and multiple tumors at anterior horns of bilateral lateral ventricles. A ventriculoperitoneal shunt and an Ommaya reservoir into the left lateral ventricle were emplaced. Three months later, she was transferred to our hospital. CT scans showed enhanced lesions in the fourth ventricle, anterior horn of the left lateral ventricle, septum pellucidum, and pituitary gland. Suboccipital craniectomy was performed, and the mass around the fourth ventricle was partially removed. Histological examination of the tumor specimens showed glioblastoma multiforme. Postoperatively, she received whole brain irradiation (total 50 Gy), and intrathecal injection of beta-interferon via the Ommaya reservoir. However, she died of respiratory insufficiency. It is considered that the spinal cord glioblastoma multiforme disseminated into the intracranial space.

Measurement of intracellular Na in the rat salivary gland: a 23Na-NMR study using double quantum filtering

23Na in the prefused rat mandibular salivary gland was measured by spin-echo double quantum filter 23Na-NMR spectroscopy at 8.45 T. Resonances due to the intracellular 23Na and the interstitial 23Na were observed in the perfused gland at 25 degrees C. The resonance due to intracellular 23Na consisted of two Lorentzian signals stemming from the [1/2 mean value of -1/2[ coherence (sharp resonance) and the [-1/2 mean value of -3/2[ and [3/2 mean value of 1/2[ coherences (broad resonance). The transverse relaxation rate constant corresponding to the [1/2 mean value of -1/2[ coherence was 95 +/- 4 s-1 and that corresponding to the [-1/2 mean value of -3/2[ and [3/2 mean value of 1/2[ coherences was 1360 +/- 75 s-1 (mean +/- S.E., n = 5). The resonance due to the interstitial 32Na had longer relaxation rate constants, and disappeared upon administration of dysprosium triethylenetetramine-N,N',N",N",N"'-hexaacetic acid.

Adenosine triphosphate compartmentation in the rat heart: a 31P spin-lattice relaxation study

Longitudinal relaxation times (T1) of phosphorus compounds in the perfused rat heart and erythrocytes were measured using the 31P Driven-Equilibrium Single-Pulse Observation of T1 relaxation (DESPOT) method at 33 degrees C. Both creatine phosphate in the heart and the three phosphate groups of adenosine triphosphate (ATP) in erythrocytes showed single-exponential relaxation. The three phosphate groups of ATP in the heart, however, had two T1 components. The T1 values of the short and the long T1 components of the beta-phosphate of ATP were ca. 0.4 and 14 s, respectively. The fraction with the long T1 represented ca. 30% of the total ATP content. These results suggested that there were two major pools of intracellular ATP in the rat heart which could be determined by 31P NMR spectroscopy.

NMR characteristics of intracellular K in the rat salivary gland: a 39K NMR study using double-quantum filtering

Intracellular K of the perfused rat mandibular salivary gland was measured by 39K NMR spectroscopy at 8.45 T. Multiple-quantum NMR arising from multiple-exponential decay was used to eliminate the resonance due to extracellular K in the perfused gland at 25 degrees C. The resonance due to intracellular K consisted of two Lorentzian signals stemming from the [spin 1/2 to -1/2] coherence (sharp resonance) and the [spin -1/2 to -3/2], [spin 3/2 to 1/2] coherences (broad resonance). The transverse relaxation time (T2) corresponding to the [spin 1/2 to -1/2] coherence was ca. 2.5 ms, and that corresponding to the [spin -1/2 to -3/2], [spin 3/2 to 1/2] coherences was ca. 0.4 ms. The relaxation time of the double-quantum coherence of rank 3 (originating from product operators like Ix2Iz) was determined to be ca. 0.2 ms. These results suggest the possibility of the presence of a single homogeneous population of intracellular K with a correlation time of ca. 2.5 x 10(-8) s and a quadrupolar coupling constant of ca. 1.4 MHz.

Energetic recovery from hypothermic preservation in the rat liver

Changes in energy metabolism induced by norepinephrine were observed in liver perfused immediately after dissection and in liver stored in Euro-Collins solution at 0 degrees C for 24 hr. Oxygen consumption, glucose output, ATP content, and tissue pH were measured in isolated perfused rat liver at 37 degrees C. In fresh liver, a two-fold increase in glucose output and oxygen consumption was induced by norepinephrine (1 microM), while changes in ATP content and tissue pH were minimal. In stored liver, the cumulative increments in glucose output and oxygen consumption induced by norepinephrine were 30 and 27% those of fresh liver, respectively. ATP content of the unstimulated liver was 76% that of the fresh liver, then decreased to 50% during stimulation. A transient decrease in tissue pH (0.14 pH unit) was significant compared with that of fresh liver. These results suggest that norepinephrine stimulation is useful for assessing energetic and functional recovery of reperfused liver following hypothermic storage.

[Partial volume effect in MRI--a phantom study]

According to the direction and the thickness of the imaging slice in tomography, the border between the tissues becomes unclear (partial volume effect). In the present MRI experiment, we examined border area between fat and water components using phantom in order to investigate the partial volume effect in MRI. In spin echo sequences, the intensity of the border area showed a linear relationship with composition of fat and water. Whereas, in inversion recovery and field echo sequences, we found the parameters to produce an extremely low intensity area at the border region between fat and water. This low intensity area was explained by cancellation of NMR signals from fat and water due to the difference in the direction of magnetic vectors. Clinically, partial volume effect can cause of mis-evaluation of walls, small nodules, tumor capsules and the tumor invasion in the use of inversion recovery and field echo sequences.

Direct measurement of K movement by 39K NMR in perfused rat mandibular salivary gland stimulated with acetylcholine

The intracellular K content (Kin) of the isolated perfused rat mandibular gland was measured by 39K NMR spectroscopy at 25 degrees C, using an inversion recovery technique based on the fact that the spin-lattice (T1) relaxation of Kin is much faster than that of the extracellular K. Kin decreased by 30-34% of the resting level and reached a plateau level during secretion evoked by a sustained infusion of 1 mumol/l acetylcholine. Addition of 1 mmol/l ouabain decreased Kin by an additional 41% of the resting level. The K net flux to the blood and saliva was calculated from the K concentrations and flow rates of the effluent and the saliva. At an initial stage of secretion the gland lost K to the vascular side at a rate of 12.6 +/- 1.8 mumol/g-min (mean +/- SEM, n = 7). During sustained secretion, the gland took K up from the vascular side at a rate of 3.3 +/- 0.7 mumol/g-min (n = 7), and the same amount of K was secreted into the saliva (4.7 +/- 1.1 at 5-10 min, 2.8 +/- 0.8 mumol/g-min at 20-30 min), resulting in no net K movement from the gland. Addition of 1 mmol/l ouabain stopped salivary secretion and caused a transient K release to the vascular side at a maximum rate of 12.8 +/- 1.1 mumol/g-min. Withdrawal of acetylcholine and ouabain induced K uptake from the vascular side (6.5 +/- 0.7 mumol/g-min) and the amount of K released was completely restored when Kin recovered completely.(ABSTRACT TRUNCATED AT 250 WORDS)

Vector electron paramagnetic resonance spectroscopy with first and second harmonic displays of ferrihemoglobin

Superimposed plots of electron paramagnetic resonance spectra with the first and second harmonic displays of ferrihemoglobin at pH 9.1 and 90 K were measured at 20 degree intervals of phase angle using a phase-sensitive detector. The high spin signal in the g = 6 region was observed in both displays, and a small splitting of the signal was found in the calculated amplitude spectrum of the second harmonic display, with g values of 5.95 and 6.05. Low spin signals were observed at g = 2.55, 2.25 and 1.82 in both harmonic displays. A signal in the g = 2.05 region was observed only in the second harmonic display. The signal is probably associated with the low spin spectrum; however, its origin is obscure.

[A case of epidermoid in the fourth ventricle associated with bronchial asthma-like symptom]

A case of large epidermoid located in the fourth ventricle is presented, and the patient's uncommon symptomatology of bronchial asthma-like episode is discussed. The value of magnetic resonance imaging (MRI) is also emphasized in the diagnosis of intracranial epidermoid. A 41-year-old male noticed nausea and vomiting on getting up in the morning about 5 years ago. This was followed by bronchial asthma-like dyspnea one year later. About one week prior to admission, headache and gait disturbance started. On neurological examination, he had choked disk and horizontal nystagmus at lateral gaze bilaterally. His gait was slightly ataxic. Computerized tomography (CT) showed a low density mass with a sharp and irregular margin in the mid-portion of the posterior fossa. That lesion was not enhanced with contrast medium. The MRI appearance was that of an inhomogenous and low signal intensity mass with a slightly irregular margin on T1-weighted spin echo (SE) sequences using TR500 msec/TR30 msec (TR500/TE30). The tumor extended into the aqueduct upward and the C1 level of spinal column downward. T2-weighted SE sequences using TR2000/TE90 showed an inhomogenous and high intensity mass with an irregular margin more apparent than in normal brain tissue. The patient was tentatively diagnosed as having a large fourth ventricle tumor. Suboccipital craniectomy was carried out on 4, March, 1988. The tumor was removed totally and histologically, it turned out to be epidermoid. He was discharged without neurological deficit 2 months after surgery. First, with respect to clinical symptomatology, as specified by Bailey, it is characterized by difficulty in standing or walking, vertigo, and less constantly, psychic disturbance.(ABSTRACT TRUNCATED AT 250 WORDS)

Capillary tube isotachophoresis of proteins in early postmortem serum, cerebrospinal fluid and pericardial fluid

Serum, cerebrospinal fluid (CSF) and pericardial fluid (PDF) obtained from 22 early cadavers were subjected to capillary tube isotachophoresis. Separated proteins were grouped into three main fractions, namely, Fr. 1, Fr. 2 and Fr. 3, in order of their decreasing effective (net) mobilities. The percentages of main fractions to total content were calculated by UV absorbance integration. It was found that Fr. 1 decreased and Fr. 2 increased in all three kinds of specimens with an increase in time following death. In serum and also in CSF, the degree of these changes between 6 and 58 hours following death seemed large enough (about 30%) to be used for crude estimations of early postmortem intervals. Changes in PDF proceeded more gradually than in serum and or in CSF, with only 5-20% changes during this period.

Intracellular pH during secretion in the perfused rabbit mandibular salivary gland measured by 31P NMR spectroscopy

Intracellular pH (pHi) was measured in the isolated, perfused rabbit mandibular salivary gland by 31P NMR spectroscopy. In the unstimulated gland perfused with HCO3-/CO2-buffered Ringer's solution, pHi was 7.27 +/- 0.01. Continuous stimulation with acetylcholine elicited dose- and time-dependent changes in pHi. 10(-6) mol/l acetylcholine caused a brief intracellular acidosis (-0.19 +/- 0.06 pH units) followed by an increase in pHi to a more alkaline steady-state value (7.33 +/- 0.02). In the absence of perfusate HCO3- or in the presence of 10(-4) mol/l DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid), the transient acidosis was abolished and pHi increased rapidly to give a sustained alkalosis (7.49 +/- 0.03 and 7.44 +/- 0.03 respectively). In the presence of 10(-3) mol/l amiloride, the response to acetylcholine was a rapid decrease in pHi to 7.02 +/- 0.02. The data suggest that, during perfusion with HCO3-/CO2- buffered solutions, stimulation with acetylcholine results in a transient loss of HCO3- from the acinar cells (causing a transient acidosis), and, independently, the activation of Na+-H+ exchange (causing a sustained alkalosis). In the unstimulated gland, DIDS and the HCO3- -free perfusate caused decreases in pHi to 7.12 +/- 0.02 and 7.04 +/- 0.01 respectively. In contrast, amiloride had little effect. The relatively high value of pHi maintained by the unstimulated gland is therefore probably not due to Na+-H+ exchange.

Acetylcholine-induced metabolic changes in the perfused rabbit mandibular salivary gland studied by 31P-NMR spectroscopy

Changes in the content of high-energy phosphates, intracellular pH (pHi) and the ratio of MgATP to total ATP ([MgATP]/[ATP]t) resulting from continuous stimulation with acetylcholine (10(-9) to 10(-4) M) were measured by 31P-NMR spectroscopy in the isolated, perfused rabbit mandibular gland at 37 degrees C. With 10(-9) to 10(-7) M acetylcholine, no significant changes in these parameters were observed. On stimulation with 10(-6) M acetylcholine, the optimal concentration for sustained secretion, the content of ATP decreased by 28 +/- 10% (mean +/- S.E.; n = 8) of its control value. pHi decreased initially by approx. 0.05 pH unit, then showed an alkalinization of 0.09 +/- 0.02 pH unit (n = 8). With 10(-5) and 10(-4) M acetylcholine, changes in ATP and pHi were similar to those induced by 10(-6) M acetylcholine: the total content of high-energy phosphates remained at approx. 70% of the control value and no decrease in [MgATP]/[ATP]t was observed. As possible causes of the reduced secretory rate observed with higher concentrations of acetylcholine (10(-5) to 10(-3) M), we can exclude depletion of high-energy phosphates, inhibition of metabolism caused by intracellular acidosis, and inhibition of ATP usage caused by a decrease in MgATP availability.

[Coronary artery blood flow velocity non-invasively measured using a vessel-tracking pulsed Doppler system]

A newly-developed noninvasive method was used to measure left coronary blood flow during phantom experiments. Two techniques were used in which: (1) the sample position can always be set in a fluctuating vessel using a wall echo-tracking method with a phase-locked-loop, and (2) the Doppler reference signal was generated separately synchronous with the wall echo signal. These techniques were combined, using a commercially available pulsed Doppler apparatus (SSH-40B: Toshiba). Basic experiments were performed using a blood vessel phantom to verify the validity of these systems. Blood flow velocity in the fluctuating tube could be measured clearly using a vessel-tracking method. The blood flow velocity of the left anterior descending artery was measured in three normal subjects and in seven patients from the third intercostal space along the left sternal border. The velocity pattern was characterized by a crescendo-decrescendo shape in diastole. The peak velocity which appeared in diastole ranged from 19 to 69 cm/sec, with no difference by disease entity. However, in all cases, the blood flow velocity signals were marred by extraneous signals, making it impossible to measure blood flow velocity during systole. Further improvement of the system is mandatory in order to use this flowmeter clinically.

Phosphorous compounds studied by 31P nuclear magnetic resonance spectroscopy in the taenia of guinea-pig caecum

1. In the isolated taenia (0.4-0.6 g) of guinea-pig caecum, the intracellular phosphorous compounds and pH were investigated using 31P nuclear magnetic resonance (NMR) under various metabolic conditions. 2. The ratios of the intracellular concentration of phosphocreatine ([ PCr]) and inorganic phosphate [( Pi]) to nucleotide triphosphate ([ NTP]) were 1.71 +/- 0.14 and 0.58 +/- 0.11 (n = 25), respectively, in normal solution (32 degrees C). The intracellular pH estimated from the chemical shift of Pi was 7.05 +/- 0.06 (n = 25), agreeing well with those previously obtained. 3. In the absence of glucose, the [PCr] and [NTP] were decreased to almost a half after 150 min exposure to 40 mM-K+ solution, while [Pi] was increased 3-fold. These changes were much faster than the rate of decline in tension. When glucose was readmitted, the contractile response to K+ fully recovered in 50 min. However, this was accompanied with only a partial recovery of [PCr] and [Pi], but no recovery of [NTP]. The intracellular pH was lowered by about 0.2 of a unit, suggesting an increase in glycolysis. 4. In Ca2+-free solution, respiratory inhibition with hypoxia or CN (1 mM) only decreased [PCr], leaving [NTP] nearly unchanged. On the other hand, respiratory inhibition in excess-K+ solution containing Ca2+ (2.4 mM) severely depleted PCr and decreased [NTP] to 40%. Increasing glucose to 50 mM did not prevent these changes, although it increased tension development. 5. The simultaneous decrease of [NTP] and [PCr] during K+ contracture suggests that the activity of creatine phosphokinase is low. The recovery from respiratory inhibition was much better for [PCr] than for [NTP]. Slow, but perfect, recovery of all NTP peaks was produced by adding 1 mM-adenosine to normal solution. 6. It was suggested that tension development is closely related to the turnover rate of ATP, and not to its concentration, and that deamination of adenosine is a limiting factor in the recovery of ATP after excessive consumption.

NMR-invisible ATP in rat heart and its change in ischemia

The subcellular compartmentalization of adenosine 5'-triphosphate (ATP) in isolated perfused rat heart and its relation to energy depletion in ischemia were examined by 31P nuclear magnetic resonance (31P-NMR) spectroscopy and chemical analyses. The signal intensities of the beta-phosphate of ATP and creatine phosphate in the 31P-NMR were standardized by the intracellular volume ratio measured with 23Na-NMR to determine the actual content of each. During aerobic perfusion the ATP content determined by NMR (13.7 +/- 2.2 mumol/g dry weight) was significantly lower than that found by chemical analysis (22.4 +/- 0.7 mumol/g dry weight), while the creatine phosphate contents determined by the two methods were the same. During ischemia at 33 degrees C, the signal of the beta-phosphate of ATP in the 31P-NMR spectrum decreased progressively, disappearing completely after 16 min. But at this time 5.7 +/- 1.7 mumol/g dry weight of myocardial ATP was still detected by chemical analysis. These results indicated that there were two different compartments of intracellular ATP in the heart, only one of which is detectable by 31P-NMR spectroscopy, and that during ischemia the ATP that is detectable, which seems to be the free ATP in the cytosol, decreased more rapidly than the ATP in the other compartment.

Dissociation of fluid secretion and energy supply in rat mandibular gland by high dose of ACh

The effects of a high dose of acetylcholine (ACh) on oxygen consumption (VO2) and changes in phosphorus energy metabolites during secretion were studied in isolated perfused mandibular gland of rats at 24 degrees C. Sugar phosphates (SP), Pi, phosphocreatine (PCr), and ATP were identified by phosphorus-31 nuclear magnetic resonance spectroscopy. One micromole ACh induced a tachyphylactic secretory response, a persistently elevated VO2, and decreased PCr and ATP; 1 mM ACh caused an initial burst of secretion that was followed by suppression of secretion and a rapid increase in the VO2 to the same level as that with 1 microM ACh. These findings indicate a dissociation between secretion and VO2. During stimulation with 1 mM ACh, the level of PCr first decreased and then partially recovered, but the level of ATP continued to decrease and the levels of Pi and SP increased markedly. These findings suggest compartmentalization of creatine phosphokinase (CPK) systems and the possibility that a high concentration of ACh interferes with the transport of PCr between one CPK system near adenosinetriphosphatase and another system near mitochondria in acinar cells.

Cortical blindness caused by acute general cerebral swelling

A 7-year-old girl who suffered from acute general cerebral swelling as a result of a traffic accident showed cortical blindness. Computed tomography (CT) scan on admission revealed marked slitlike ventricles and narrowing of the perimesencephalic cisterns, which indicated general cerebral swelling. While hospitalized, the patient developed transtentorial herniation twice on day 3, and CT scans at herniation episodes showed disappearance of the perimesencephalic cisterns. After recovery of consciousness, the patient showed cortical blindness, and during gradual recovery she showed pure alexia without agraphia. The visual evoked potentials at 8 weeks, 16 weeks, and 3 years 4 months after trauma showed normalization of the pattern, but revealed left occipital inactivity.

Phosphorus nuclear magnetic resonance in isolated perfused rat pancreas

Phosphorus nuclear magnetic resonance spectroscopy was applied to measure phosphorus energy metabolites in isolated perfused rat pancreas. The gland was perfused with a modified Krebs-Henseleit solution at room temperature (25 degrees C). 31P resonances of creatine phosphate (PCr), ATP, ADP, inorganic phosphate (Pi), and phosphomonoesters (PMEs) were observed in all the preparations of pancreas. In different individual preparations, the resonance of PCr varied, but those of ATP were almost the same. The initial levels of PCr and ATP in individual preparations, however, remained almost unchanged during perfusion with the standard solution for 2 h. When the perfusion was stopped, the levels of ATP and PCr decreased, while the levels of PME and Pi increased. At that time, the Pi resonance shifted to a higher magnetic field, indicating that the tissue pH decreased. On reperfusion, the tissue levels of phosphorus compounds and the tissue pH were restored to their initial resting levels. Continuous infusion of 0.1 microM acetylcholine caused marked and sustained increases in the flow of pancreatic juice and protein output. During the stimulation the tissue levels of phosphorus compounds remained unchanged, while the tissue pH was decreased slightly (0.05 pH unit).

An experimental approach to 31P spin-lattice relaxation time measurement in biological systems

The accuracy of measurement of the spin-lattice relaxation time (T1) in biological systems using the variable nutation angle method is discussed using computer simulations. This method could reduce the time required for measurement to 10% of that using the inversion recovery method. In the perfused salivary gland of the rat (310 K), the T1 values of sugar phosphates, creatine phosphate, gamma-phosphate, and beta-phosphate of nucleotide triphosphates determined by this method were 5.2, 4.8, 0.9, and 0.8 s, respectively. During secretion of saliva, the T1 value of sugar phosphates decreased to 3.7 s, which could be due to an increased chemical exchange of phosphate in glycolysis.

[A case of colon cancer with pulmonary metastasis treated effectively by uracil futraful]

A 57-year-old female was admitted for advanced ascending colon cancer with a solitary pulmonary metastasis measuring 1.5 cm in diameter. As laparotomy revealed an absolute noncurable tumor of stage V (H0, p2, s2 n1 (+], palliative right hemicolectomy was performed. A pathological diagnosis of well differentiated adenocarcinoma was made postoperatively. A daily dose of 400 mg of UFT was given orally. After 8 months, plain chest film and tomography revealed a reduction in the size of the pulmonary metastasis to 1.0 cm in diameter. The metastatic lung tumor was controlled for a period of 1 year and 9 months. It was suggested that UFT was rather effective for pulmonary metastasis from colon cancer.

Evaluation of intraoperative radiotherapy for carcinoma of the pancreas: prognostic factors and survival analyses

Among 145 patients with carcinoma of the pancreas who had been admitted to three institutions between 1976 and 1985, 117 were entered into a prognostic factor analysis system according to Cox's proportional hazards model. The treatment was classified into four modalities: bypass surgery, single-dose intraoperative radiotherapy (IOR), IOR combined with external irradiation, and resection with or without various radiations. The most important prognostic factors for treatment were identified as location of tumor, TNM stage, and relief of back pain. Adjusting the imbalances among the treatment groups using Cox's model, the superiority of IOR with external irradiation was confirmed for both bypass and single-dose IOR. With this adjustment, the survival rates proved to be more meaningful than the simple Kaplan-Meier estimates.

[Serum concentration of 5-FU and tegafur (FT-207) after administration of tegafur (FT-207) suppository with the colostomy]

Tegafur (FT-207) suppositories were administered at a rate of 750 mg via the artificial anus (ST Group) following surgery of rectal cancer. Comparative studies were conducted of changes in blood concentrations of 5-FU and tegafur at the time of initial administration and following one week of continuous use for the low-anterior resection cases (LA Group) and the rectal administration cases (RE Group). FT-207 concentration at initial administration was low in the ST group compared to those for both LA and RE groups which received anal administration of the drug, but only little changes were noted. Blood concentration one hour after administration was 11.1 micrograms/ml, elevated to 14.3 micrograms/ml at two hours, and remained at 10 micrograms/ml and above for six hours following administration. The ST group 5-FU concentrations at two, four and six hours after administration were significantly lower than those in the RE group but the changes were little. Blood concentrations were 0.015 microgram/ml at one hour after administration, 0.017 micrograms/ml at two hours and maintained virtually the same level thereafter. An effective concentration of 0.012 microgram/ml was maintained even at ten hours following administration. After one week of administration of the suppositories, the ST group showed the lowest concentration among three groups, but it was approximately double compared to the initial concentration; FT-207 showed nearly the same concentration in the LA group and 5-FU blood concentration was 0.025 microgram/ml at one hour after administration, reached to a maximum of 0.030 microgram/ml at two hours and maintained 0.020 microgram/ml and higher at ten hours. 5-FU concentration in the LA and RE groups after one week of continuous administration showed a dual-peaked pattern. No patient with an abnormal artificial anus was involved in this study. The artificial anus is thought to be an adequate and effective administration route of FT-207 suppositories.

Direct measurement of Na influx by 23Na NMR during secretion with acetylcholine in perfused rat mandibular gland

Intracellular Na content (Nain) in the perfused rat mandibular gland was measured by using a 23Na NMR spectroscopy at 24 degrees C. An aqueous chemical shift reagent, dysprosium triethylenetetramine-N,N,N',N",N"'N"'-hexaacetic acid [Dy(TTHA)] was used in order to discriminate between the intracellular and the extracellular Na signal. The mandibular gland of rat was perfused arterially with a modified Krebs solution containing 10 mM Dy(TTHA). At rest, Nain was not changed by blocking the Na+/K+ ATPase with ouabain (1 mM) and atropine (3 microM), implying that, in the absence of stimulation, the spontaneous Na influx across the plasma membrane must have been negligibly small. Following onset of stimulation with acetylcholine (1 microM), Nain increased by 9.1 +/- 1.5 mmol/l intracellular fluid (mean +/- SEM, n = 13), and remained at this level during stimulation. In the initial phase of secretion (0-5 min), about 50 mmol/min/l intracellular fluid of Na was secreted into the luminal space (estimated from the secretory rate by assuming an isotonic primary secretion) but, in spite of the higher secretion rate, Nain increased only at an initial rate of 4.1 mmol/min/l intracellular fluid. During the steady phase of secretion (15-30 min) evoked by acetylcholine (1 microM), ouabain (1 mM) caused an increment of Nain of 44 +/- 8 mmol/l intracellular fluid (mean +/- SEM, n = 4). From the rate of Nain increment, the Na influx rate at the steady phase was estimated as 4.5 mmol/min/l intracellular fluid. These results suggest that the influx of Na is caused by stimulation with acetylcholine.(ABSTRACT TRUNCATED AT 250 WORDS)

High resolution 23Na-nuclear magnetic resonance study of stroke-prone spontaneously hypertensive rat erythrocytes

The intracellular Na+ content of washed erythrocytes from stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto normotensive rats (WKY) was measured by a high resolution 23Na-nuclear magnetic resonance (NMR) technique using a non-permeant aqueous shift reagent, dysprosium triethylenetetramine hexaacetic acid, Dy(TTHA)3-. The initial intracellular Na+ of freshly isolated and washed erythrocytes was very low (approximately 5 mmol/l) and increased progressively with prolonged incubation in isotonic salt solution at 37 degrees C. There was no significant difference in the erythrocyte Na+ concentration between SHRSP and WKY over the entire period of measurement, nor was any difference detected in their osmotic fragility or total cellular volume, although the osmotic fragility decreased with incubation time. The high energy phosphate metabolites were also studied in the same erythrocytes by 31P-NMR. The level of intracellular ATP decreased with incubation at 37 degrees C but showed no difference between the SHRSP and WKY samples. Inclusion of 1 mmol/l ouabain in the incubation medium substantially retarded the breakdown of intracellular ATP and resulted in a concomitant increase in intracellular Na+. However, neither the ouabain-sensitive nor the ouabain-insensitive component of Na+ influx altered in SHRSP erythrocytes compared with WKY erythrocytes in paired experiments. Our results do not support the hypothesis that altered Na+ transport, resulting in an increase in erythrocyte Na+ concentration, is associated with spontaneous hypertension.

[Intraoperative radiotherapy]

Intraoperative radiotherapy, which delivers a large single dose of electrons to a tumor intraoperatively, is applied for locally advanced and/or difficult to cure malignancies which are rather difficult to treat by conventional external beams. Although this method was initially developed in Japan, increasing numbers of institutes have recently been working with IORT on a world-wide basis because of the increased availability of medical accelerators and the better results obtained. The malignancies for which IORT is indicated are cancers of the stomach, liver, biliary tract, pancreas, colo-rectum, urinary bladder, prostate and uterus, which are surrounded by normal tissues or organs with low tolerance doses, and also recurrent or difficult to cure malignancies of the brain, lung, mediastinum, bone and soft tissues are becoming candidates for IORT treatment.

31P NMR studies on the isolated perfused mandibular gland of the rat

Phosphorus nuclear magnetic resonance (31P NMR) was used to study energy metabolism in the rat mandibular gland. The gland was isolated, perfused arterially and set in the NMR tube. At rest, 7 resonance peaks were observed and 6 peaks identified from low field as: 1) sugar phosphates (SP) and nucleotide monophosphate (NMP), 2) inorganic phosphate (Pi), 3) creatine phosphate (PCr), 4) gamma-nucleotide triphosphate (NTP) and beta-nucleotide diphosphate (NDP), 5) alpha-NTP, alpha-NDP, NAD+, and NADH, 6) an unknown peak, and 7) beta-NTP. From the results of high performance liquid chromatography (HPLC), NTP consisted mainly of ATP and GTP, and UTP was not detected. The tissue contents of ATP and GTP in the perfused gland were determined by HPLC as 1.86 +/- 0.03 and 0.37 +/- 0.01 mmol/kg wet tissue (S.E., n = 5). From 31P NMR and HPLC data, the tissue levels of creatine phosphate, ADP, and sugar phosphates were estimated as 3.3, 0.4, and 4.2 mmol/kg wet tissue, respectively. The cessation of perfusion decreased the tissue levels of PCr and ATP and increased those of Pi and SP. On the other hand, administration of acetylcholine (1 microM), which is an optimal dose for secretion, decreased PCr and increased Pi but did not change SP. The ATP was unchanged initially and slowly decreased to the lower level during sustained secretion. These findings suggest that a sustained secretion requires more energy from ATP hydrolysis rather than initial secretion.

Continuous measurements of Na, Li, and Cl in the perfused salivary gland by use of NMR

The present study was undertaken to measure tissue contents of Na, Li, and Cl non-invasively in the isolated perfused organ by nuclear magnetic resonance (NMR) using a broadband tunable probe. The NMR signals of 23Na, 7Li, and 35Cl from the isolated perfused rat mandibular gland were collected continuously and each spectrum was obtained for every 15 or 20 s. The Na concentration in the perfusate was varied by replacement with Li, and the resulting changes were monitored by measuring the signal intensities of the electrolytes. The time constant for Na exchange was slower following complete removal of extracellular Na than following its half replacement, suggesting that the Na extrusion by Na+/K+ ATPase was reduced by lowering the extracellular Na level. The time constant for Li exchange was slower than that for Na exchange. The level of Cl was nearly constant during experiment, except for a very slow increase in Cl, possibly resulting from increasing edema and/or intracellular Li storage.

[Radiotherapy of pancreatic carcinoma]

During the 10-year period between 1974 and 1984, we treated 34 pancreatic carcinomas by radiotherapy as follows: Eight by intraoperative radiotherapy (IOR), five by external radiotherapy (ERT), and 21 by IOR in combination with ERT. The mean survival time of the eight patients treated by IOR was 5.6 months, and that of the 21 receiving the combination therapy 7.2 months. Although it is not statistically significant, patients treated by the combined regimen survived longer than those treated by IOR alone.

31P-NMR study of dog submandibular gland in vivo and in vitro using the topical magnetic resonance

The topical magnetic resonance (TMR) was used to study the phosphorous metabolism of a dog's submandibular gland during acetylcholine stimulation. The experiments were carried out under two conditions. One was a normal blood supply (in vivo) and the other was vascular perfusion with the artificial perfusate (in vitro). The levels of phosphorous compounds in the gland were obtained for 31P-NMR spectra of the TMR. The saliva was secreted in the both conditions, though the salivary flow under the in vivo condition was higher than in vitro. During salivary secretion, only the levels of creatine phosphate decreased under in vivo condition, while the levels of creatine phosphate and ATP decreased and the levels of inorganic phosphate increased in in vitro cases. It was concluded that the decrement of creatine phosphate during the salivary secretion indicates the acceleration of the energy metabolism in the submandibular gland.

Effects of extracellular pH on lactate efflux from frog sartorius muscle

The isolated sartorius muscle of frog was stimulated under an anaerobic condition, and intracellular lactate concentration and intracellular pH was determined sequentially by 1H-nuclear magnetic resonance, and the efflux of lactate was measured by an enzymatic method on the incubation media with different pH levels. The lactate efflux was shown to increase in proportion to the concentration difference of lactate across the membrane up to 25 mmol X l H2O-1, and the permeability of the membrane to lactate increased with the increment of extracellular pH. H+ efflux was determined from pH change and the buffer capacity of incubation medium. The efflux of H+ rose approximately linearly with the efflux of lactate up to approximately 70 mumol X min-1 X l H2O-1, and the relationship then revealed a clear leveling off. From these results the efflux of lactate was analyzed in terms of a predominantly nonionic or a predominantly ionic efflux mechanism. Analysis showed that the mechanism of efflux was in both the ionic and nonionic form.

Effects of Na+ depletion on fluid secretion and levels of phosphorus compounds as measured by 31P-NMR in perfused canine mandibular gland

The dependency of fluid secretion on extracellular Na+ and the levels of phosphorus compounds were studied in the perfused canine mandibular gland (using 31P-NMR). During control perfusion, the resting levels of creatine phosphate (CP) and ATP were 0.62 +/- 0.05 mmol . kg-1 gland and 0.42 +/- 0.04 mmol . kg-1 (mean +/- S.E., n = 9), respectively. Acetylcholine (Ach; 1 mumol . l-1 for 3 min) induced a salivary secretion and decreased the CP level. When Na+ in the perfusate was completely replaced with Li+, Ach induced only a minimal salivary secretion and no change in the ATP and CP levels. Restitution of Na+ to the perfusion, even without added Ach, caused a decrease in ATP and CP, and a small increase in salivary secretion. These results suggest that the activity of Na+/K+ ATPase is increased inversely via a rise of the intracellular Na+ concentration and that the salivary secretion is induced not only by added secretagogues but by an increase in the Na+ entry without added secretagogues.

In vivo 31P-NMR studies on aerobic recovery of frog muscle following tetanus

Aerobic recovery after a 60-sec tetanus of skeletal muscle of frog was studied using the in vivo 31P-NMR method with a topical magnetic resonance spectrometer (TMR) at 17 degrees C. Creatine phosphate recovered with a time constant of about 25 min-1. Sugar phosphates increased by the Pasteur effect, and saturated at about 4.5 mmol/kg muscle. The high level of the sugar phosphates was sustained during the following 60 min.

Intracellular pH determination by a 31P-NMR technique. The second dissociation constant of phosphoric acid in a biological system

To evaluate the accuracy of pH determination by 31P-NMR, factors which influence the pK value of phosphate were appraised on the basis of the titration of 1 mM phosphate buffer solution. When the method is used for the determination of cytoplasmic pH, ionic strength is the major factor causing shifts of apparent pK (pK') value, and the magnitude of the shift can be predicted from the ionic strength calculated by means of the Debye-Hückel equation. Ions (Na+, K+, Mg2+, and Ca2+) and salivary protein affected the pK' value by 0.1 to 0.3 units in solution with a given ionic strength depending on the species of ion. The form of the titration curve varied with temperature. Based on these results, the value of 6.75 was obtained with the uncertainty of 0.12 for the intracellular pK' of frog muscle at 24 degrees C.

Phosphorus nuclear magnetic resonance of perfused salivary gland

Phosphorus nuclear magnetic resonance (31P-NMR) was used for the sequential measurement of phosphorus energy metabolites in perfused canine submandibular gland. Under resting conditions, ATP and creatine phosphate levels were 0.42 +/- 0.11 mM and 0.62 +/- 0.16 mM (mean +/- S.D., in nine glands). When perfusion of the gland was stopped, the tissue contents of ATP and creatine phosphate decreased, that of ADP increased and tissue pH decreased. Restarting perfusion led to recoveries of the tissue content of the phosphorus compounds and tissue pH to normal. Acetylcholine administration induced secretion of saliva, decreased the level of ATP, creatine phosphate and tissue pH, and increased the ADP level.

A 1H-nuclear magnetic resonance study on lactate and intracellular pH in frog muscle

High resolution proton magnetic resonance spectra of intact frog muscle, obtained by the selective saturation of water signal with 15 min accumulation, showed well-resolved signals from lactate, carnosine, and other compounds. This technique was used to monitor the changes in lactate content and in intracellular pH which was estimated from the chemical shift of carnosine in muscle. The intracellular pH was estimated to be 7.1 in fresh muscles. Under an anaerobic condition, resting muscle showed a gradual increase in lactate content with intracellular acidification. When the anaerobic muscle was electrically stimulated for 5 sec, a transient acceleration of the lactate production and the intracellular acidification was observed. The intracellular buffer value was estimated to be 27 mEq/(pH X kg muscle), based on the pH change due to the increase in lactate content.