Intravenous midazolam suppresses noxiously evoked activity of spinal wide dynamic range neurons in cats

The effects of intravenously (i.v.) administered midazolam on noxiously evoked activity of spinal wide dynamic range (WDR) neurons were investigated in decerebrate, spinal-cord-transected cats. Extracellular, single-unit recordings were measured during stimulation by pinching the receptive field on the hind paw and the effect of midazolam at doses of 0.25, 0.5, 1, 2, and 4 mg/kg were measured. Two series of experiments were performed to characterize the analgesic effects of midazolam. In the first, dose-response experiments (n = 59) demonstrated a dose-dependent suppression of the noxiously evoked activity of spinal WDR neurons after midazolam administration. This effect of midazolam was maximal at a dose of 1 mg/kg i.v.. The second series of experiments (n = 14) demonstrated that a benzodiazepine antagonist, flumazenil (n = 8), promptly reversed the effect of midazolam, while an opioid antagonist, naloxone (n = 6), had no effect on the effect of midazolam. The present study demonstrates that i.v. administered midazolam suppresses noxiously evoked activity of spinal WDR neurons that is reversible by a benzodiazepine antagonist. This is consistent with an analgesic action of midazolam.

Fast spin-echo MR imaging of non-Hodgkin lymphoma arising from chronic tuberculous empyema

Non-Hodgkin lymphoma (NHL) rarely arises from tuberculous empyema. We report a case in which magnetic resonance (MR) imaging was useful in separating the lymphoma from the chronic empyema.

Effect of particle size on alumina-induced production of reactive oxygen metabolites by human leukocytes

To assess the role of crystal size in the biologic response, we quantitated the generation of reactive oxygen metabolites in human polymorphonuclear leukocytes (PMNs) or mononuclear leukocytes (MNs) with a chemiluminescence assay using 6 alpha-alumina preparations with average diameters of 0.6, 0.8, 3.2, 7.5, 28 and 68 microns on the basis of equal weights (1 mg/ml), and also on the basis of surface areas (100 cm2/ml). On an equal weight alumina particles induced PMN chemiluminescence in the following order of magnitude: 3.2 microns > 7.5 microns, 0.8 micron > 0.6 micron > 28 microns, 68 microns. The particulates induced MN chemiluminescence: 3.2 microns > 0.8 micron > 0.6 micron > 7.5 microns > 28 microns, 68 microns. On the basis of identical surface areas, alumina elicited PMN chemiluminescence: 3.2 microns > 7.5 microns, 0.8 micron > 0.6 micron, 28 microns, 68 microns. The particulates induced MN chemiluminescence: 3.2 microns > 0.8 micron > 0.6 micron, 7.5 microns > 28 microns, 68 microns. The maximal effect of particle size on the alumina-induced production of reactive oxygen metabolites by human leukocytes was seen at around 3 microns.

[Anesthetic management of a patient with adrenocorticotropic hormone (ACTH) deficiency]

A 73 year old woman with ACTH deficiency was admitted to our hospital for gastrectomy. She had taken corticosteroid for 3 years. The day before surgery, she took 25 mg of hydrocortisone per os. Hydrocortisone 100 mg was administered intravenously 30 minutes before surgery, during and after surgery, and on the next day after surgery. Serum concentrations of ACTH and cortisol were measured 1 hour after the first administration of hydrocortisone 100 mg, 2 hours after the second and 15 hours after the third administration. The ACTH concentration was always lower than the lowest limit of detection. Cortisol concentrations were 140.0, 180.0 and 14.5 micrograms.dl-1 at each measurement. Serum concentration of aldosterone after the induction of anesthesia was lower than the normal range. Her hemodynamics were very stable and electrolytes balance was not disturbed with corticosteroid treatment during and after surgery.

[Effects of inorganic fluoride, inhalation time and dosage of sevoflurane on renal function during sevoflurane anesthesia of long duration]

In sevoflurane anesthesia of long duration, we studied correlations with renal function of the area under the curve (AUC), rate of decrease and maximum level of serum inorganic fluoride (F), sevoflurane dosage, and duration of administration. In 15 neurosurgical patients, we measured serum and urine levels of F, blood urea nitrogen (BUN), creatinine, serum and urine beta 2-microglobulin (BMG), and urine N-acetyl-beta-D-glucosaminidase (NAG). AUC and the rate of decrease of serum F were calculated. There were no correlations among the maximum level, AUC, the rate of decrease of serum F, sevoflurane dosage, duration of administration, BUN, creatinine, BMG, and NAG. It is concluded that in sevoflurane anesthesia of long duration, F, sevoflurane dosage and duration of administration do not affect renal function.

Salt sensitivity of blood pressure in patients with 17 alpha-hydroxylase deficiency

To clarify the salt sensitivity of blood pressure in 17 alpha-hydroxylase deficiency (17 alpha-HD), a mineralocorticoid-induced hypertension, we examined the responses of blood pressure to salt loading (250 mEq/day for 6 days) after salt restriction (25 mEq/day for 3 days) in two 17 alpha-HD patients who had markedly high plasma deoxycorticosterone (DOC) (5.27 and 6.59 ng/mL; normal, 0.08 to 0.28) and corticosterone (B) (93 and 357 ng/mL; normal, 0.35 to 8.42). In case 1, moreover, the same study was repeated when plasma DOC and B restored to almost normal with the dexamethasone treatment (1 mg/day) (0.34 and 0.45 ng/mL). Salt loading elevated mean blood pressure markedly in both patients (14% and 20%), associated with cumulative sodium retention and body weight gain. Hemodynamic study showed marked increases in cardiac output (25% and 69%), but only slight decreases in systemic vascular resistance with salt loading. On the other hand, the treatment with dexamethasone could attenuate the salt-induced increase in blood pressure (2%), accompanied by lesser sodium retention, body weight gain, and elevation of cardiac output (7%) in case 1. The slope of the renal function curve for sodium excretion was decreased in these patients, and was restored toward normal by dexamethasone in case 1. We conclude that the patients with 17 alpha-HD showed salt-sensitive hypertension due to excessive DOC and B, through the impaired renal function for sodium excretion, disproportionate increase in cardiac output, and inadequate vasodilation.

Sequencing and expression of sheep angiotensinogen cDNA

A sheep liver cDNA library was screened with a BstEII fragment of human angiotensinogen cDNA to obtain sheep angiotensinogen cDNA. The cDNA sequence showed that preangiotensinogen consisted of 452 amino acid residues (49 kDa) of angiotensinogen and 24 residues of a signal peptide. Recombinant sheep angiotensinogen (56 kDa) was expressed in COS-7 cells.

[Effects of hyperventilation upon the spinal pain modulating system (third report)]

The purpose of this study is to investigate the mechanisms of the effect of hyperventilation on the spinal pain modulating system by using phentolamine. Under enflurane anaesthesia, cats received mid-collicular decerebration and lumbar laminectomy. The spinal cord was transected at T12-L1. WDR cells, responding primarily to noxious peripheral stimuli, were sampled with a microelectrode at the depth of 2,000 microns from the cord dorsum. Following the control period, ventilation was changed to induce hypocapnia of PCO2 20-25 mmHg. After activities were well suppressed, phentolamine 0.5 mg with normal saline 1.0 ml was injected on the spinal cord. Changes of firings were investigated. When normocapnia was resumed, recovery followed. Hypocapnia of PCO2 20-25 mmHg significantly suppressed the activities of WDR cells. Phentolamine significantly antagonized the suppressive effects of hyperventilation upon the activities of WDR cells. Our results suggest that the hyperventilation has suppressive effects on single-unit activity of WDR cell and the mechanisms of those suppressive effects are related to adrenergic pain modulating system.

[A case of acute renal failure in neuroleptic malignant syndrome associated with rhabdomyolysis--possible contributing role of hyperreninemia]

A schizophrenic woman, aged 45, was admitted complaining of high fever, oliguria, blackish urine, muscle swelling and pain. She had been treated for the past 3 years with haloperidol (8 mg), levomepromazine (150 mg), chlorpromazine (75 mg), lithium carbonate (600 mg), bromocriptine mesilate (7.5 mg), etizolam (1 mg), and flunitrazepam (2 mg), Physical examination revealed her to be an obese and uncommunicatable woman with swelling and weakness of the extremities and abdominal distension without borborygmus. Urine was dark brown and (+) for protein and occult blood. Blood chemistry analysis revealed BUN 71 mg/dl, creatinine 6.8 mg/dl, CPK 143,850 IU and myoglobin 3,980 ng/ml. PRA on the 11th hospital day was 96 ng/ml/hour. This patient fulfilled the Levenson's diagnostic criteria for manifestations of neuroleptic malignant syndrome (NMS). High PRA did not decrease after cessation of the diuretics. After treatment with dantrolene sodium and 10 treatments with hemodialysis, azotemia disappeared with the start of diuresis. The PRA also decreased to the normal level. Characteristic acceleration of the central sympathetic stimuli in NMS seemed to have induced hyperreninemia, which together with rhabdomyolysis, might have contributed to the development of acute renal failure.

The effect of pentobarbital sodium on the dorsal horn of the spinal cord

The effect of intravenously administered pentobarbital sodium on the activity of single unit in Rexed lamina V of the transected feline lumbar spinal cord was studied using an extracellular microelectrode recording technique. Pentobarbital sodium 1.0 mg·kg(-1), 2.5 mg·kg(-1), and 5.0 mg·kg(-1) administered intravenously suppressed both the spontaneous and the evoked activity in Rexed lamina V cells, known to respond principally to noxious stimuli, in a dose-dependent manner. The maximum depression of cell activity occurred within 5 min after intravenous administration. The recovery of cell activity occurred within 70 min after intravenous administration of pentobarbital sodium. We conclude that pentobarbital sodium intravenously administered has a suppressive effect on single unit activity of cells in Rexed lamina V and probably has an analgesic effect. Its suppressive effect is dose-dependent.

[Anesthesia for a pregnant patient with ruptured cerebral arterio-venous malformation]

A 29 year old woman suffered sudden hemiplegia, vomiting and headache during the 28th week of her first pregnancy. She was diagnosed as the intracranial hemorrhage due to the ruptured arteriovenous malformation, and emergency operation was performed. Anesthesia was induced with crush induction using thiamylal, fentanyl, pancuronium and suxamethonium, and maintained with fentanyl, isoflurane and nitrous oxide in oxygen. During and after surgery, fetal heart rate and uterine contraction were monitored continuously. Intense hypotension was not chosen because it may place a fetus at risk of intrauterine asphyxia. Ventilation was controlled to maintain PaCO2 between 30 and 35 mmHg. During surgery, D-mannitol 60 g was infused slowly to prevent fetal dehydration, and after surgery no osmotic diuretics were used. Ritodrine hydrochloride, which prevented premature delivery, was continuously infused after surgery. Her neurological symptom was improved and her baby was delivered vaginally at 41st gestational week.

Priming effect of hydroxyapatite on the chemiluminescence response in human polymorphonuclear leukocytes

In order to determine whether hydroxyapatite modulates the response of polymorphonuclear leukocyte (PMN) to oxidative stimuli, human PMNs were incubated with a non-activating concentration (1 or 10 micrograms/ml) of hydroxyapatite prior to stimulation with N-formyl-methionyl-leucyl-phenylalanine (FMLP; 0.1 or 1 microM), phorbol 12-myristate 13-acetate (PMA; 100 pg/ml), sodium fluoride (50 microM), zymosan (1 microgram/ml), or the calcium ionophore A23187 (0.1 microM). Chemiluminescence was measured with an automatic microcomputer-controlled luminescence analyzer at 37 degrees C. Hydroxyapatite alone did not stimulate chemiluminescence at concentrations below 10 micrograms/ml. Levels 300-400% higher than 'stimulus only' controls without preincubation with hydroxyapatite have been recorded. This synergism between hydroxyapatite and subsequent stimuli reveals a new activity of hydroxyapatite and suggests that particulate material may prepare PMNs for an exaggerated inflammatory response to other phlogistic mediators. This is the first report demonstrating PMNs primed with particulate material.

Post-prandial triglyceride-rich lipoprotein metabolism: possible role of sialilated apolipoprotein E isoproteins

While serum concentrations of triglyceride (TG) and apolipoprotein (apo) E decreased significantly after 75 g glucose load, serum triglyceride concentration increased markedly and apoB concentration decreased significantly after 100 g fat load in 10 healthy men. Chylomicrons and very low density lipoproteins (VLDL) increased after the fat load but decreased after the glucose load. ApoB-100/B-48 ratio in VLDL fraction decreased slightly at 30 min and increased markedly at 60 min after the glucose load. On the other hand, the ratio decreased definitely at 30 min and then increased until 90 min after the fat load. Isoelectric focusing (IEF) and two-dimensional gel electrophoresis revealed that the relative concentration of sialilated apoE in VLDL fraction decreased after the glucose load and increased after the fat load. In hypertriglyceridaemic patients, apoE3S1/E3 ratio in VLDL fraction was significantly higher than that in normal and hypercholesterolaemic patients. The results suggest that some structural changes in apoE, due probably to sialilation, may exert an influence on the hepatic uptake of the lipoproteins.

Stereotyped behavioral responses to an auditory stimulus in the course of repeated treatment with methamphetamine plus scopolamine and methamphetamine in rats

The present experiment was designed to study the effects of an auditory stimulus with 300 Hz, 100 dB on gradual emergence of behavioral sensitization in the course of repeated administration of methamphetamine (MAP) in combination with scopolamine (SCOP) and MAP. Repeated intraperitoneal injection of MAP (4.0 mg/kg) plus SCOP (0.5 mg/kg) induced significantly progressive and enduring enhancement of stereotyped behavior, resulting in intense, focussed stereotypy intermingled with gnawing and licking compared to repeated MAP treatment. Vigorous stereotyped behavior induced by repeated MAP plus SCOP was progressively attenuated by the tone, resulting in attenuation of the development of behavioral sensitization. Conversely, the tone had no invariable effects on behavioral sensitization induced by repeated MAP treatment. The present findings indicate that repeated MAP plus SCOP treatment progressively induced attenuating effects of tone as low as 300 Hz on MAP plus SCOP-induced intense stereotypy and vigorous behavioral sensitization. These findings suggest that a reciprocal balance between dopaminergic and cholinergic inhibitory systems may be involved in producing behavioral sensitization, and in the attenuating effects of the tone on MAP plus SCOP-induced vigorous behavioral sensitization.

Low serum aminotransferase activity in patients undergoing regular hemodialysis

Of 150 patients undergoing regular hemodialysis (HD), 14 (9.3%) and 12 (8.0%), respectively, showed low serum activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). An investigation was conducted to elucidate the underlying mechanisms in 20 patients with low serum AST and/or ALT activity. Fifty-five percent of the patients with low aminotransferase activity manifested serum levels of pyridoxal phosphate (PLP) that were lower than normal. Serum PLP levels correlated neither with AST nor with ALT activity. Oral administration of vitamin B6 to the cases with low aminotransferase activity resulted in an increase in pre-hemodialysis aminotransferase activity. Addition of vitamin B6 in vitro to the sera from the patients with low aminotransferase activity did not increase the values when the added vitamin B6 was within the physiological range, but did increase when added in larger (pharmacological) amounts. However, aminotransferase activity increased, but PLP levels remained unchanged when these values were compared before and after HD. On the other hand, guanase being within the normal range in all cases studied, did not change after HD. Although our study does not correlate with vitamin B6 deficiency, but rather with some uremic substance(s) which interfere(s) with the enzyme reaction as a cause of low aminotransferase activity, the fact that less than 10% of our patients showed low AST and/or ALT points to the latter possibility, suggesting the need of further study.

[The effects of hyperventilation upon the spinal pain modulating system (second report)]

The purpose of this study is to investigate the effect of hyperventilation on the spinal pain modulating system by using naloxone. Under enflurane anaesthesia, cats were prepared with midcollicular decerebration and lumbar laminectomy. The spinal cord was transected at T12-L1. WDR cells, responding primarily to noxious peripheral stimuli, were sampled with a microelectrode at the depth of 2,000 microns from the cord dorsum. Following the control period, ventilation was adjusted to produce hypocapnia of PCO2 20-25 mmHg. After activities of WDR cells were well suppressed, naloxone 0.1 mg.kg-1 was given intravenously. Changes of firings of WDR cells were investigated. Returning to normocapnia, recovery of firings was followed. Hypocapnia of PCO2 20-25 mmHg significantly suppressed the activities of WDR cells. Naloxone significantly antagonized the suppressive effects of hyperventilation upon the activity of WDR cell. Our results suggest that the hyperventilation has suppressive effects on single-unit activity of WDR cell and the mechanisms of those suppressive effects are related to pain modulating system by endogenous opiates.

Correlation between histologic features and glomerular permeability in membranous nephropathy and immunoglobulin A nephropathy

We evaluated the correlation between histologic features and glomerular permselectivity based on fractional clearances of dextrans relative to inulin (FCsDex). The subjects consisted of 12 healthy volunteers, 18 patients with membranous nephropathy, and 20 patients with immunoglobulin A nephropathy. In membranous nephropathy, FCsDex measured with large dextrans (radii larger than 56 A) increased as the capillary lesion progressed. Histologic examination showed that glomerular capillary alteration was the factor most closely linked to changes in FCsDex in membranous nephropathy. Proteinuria (normalized to glomerular filtration rate) did not correlate with FCsDex. Increased FCsDex tended to normalize during prednisolone treatment in membranous nephropathy. In immunoglobulin A nephropathy, the impairment of glomerular size selectivity depended on the degree of mesangial sclerosis and tubulointerstitial injury. FCs of dextrans of 59 A were correlated with the mesangial sclerosis index (r = 0.573, p = 0.050) and the tubulointerstitial injury index (r = 0.707, p = 0.003). Proteinuria (again normalized to glomerular filtration rate) was significantly correlated with FCs of large dextrans in immunoglobulin A nephropathy (r = 0.668, p = 0.008). We conclude that glomerular size-selective barriers were impaired both in membranous nephropathy and immunoglobulin A nephropathy. However, the mechanisms of impaired size selectivity might differ, at least in part, between these nephropathies. The predominant factors responsible for the size-selective defect seemed to be glomerular capillary wall lesions in membranous nephropathy but mesangial sclerosis or tubulointerstitial damages (or both) in immunoglobulin A nephropathy.

[The effects of hyperventilation upon the spinal pain modulating system]

The purpose of this study is to investigate the effects of hyperventilation on the wide dynamic range (WDR) cell of the dorsal horn of the feline lumbar spinal cord. Cats received midcollicular decerebration and lumbar laminectomy. The spinal cord was transected at T12-L1. WDR cells were sampled with microelectrode at the depth of 2,000 microns from the cord dorsum. Following the control period with PaCO2 of 35-45 mmHg, respiratory rate and tidal volume were adjusted to make a level of hypocapnia as low as 20-25 mmHg. The recovery of cell activity was followed when normocapnia was restored. Hypocapnia with PaCO2 of 25-30 mmHg and 20-25 mmHg suppressed the activity of WDR cell significantly. At PaCO2 of 25-30 mmHg, the spontaneous activity was suppressed for about 20% and evoked activity for 27%. At PaCO2 of 20-25 mmHg, the spontaneous activity was suppressed for about 50% and evoked activity for 33%. The results suggest that the hyperventilation has suppressive effects on single-unit activity of WDR cell.