Responses of somatosensory cortical neurones to tooth pressure and their modulation by transient mouth opening in the cat

One hundred and thirty two cortical neurones sensitive to mechanical tooth stimulation were detected from the caudal part of the coronal gyrus of the cat. They responded to transient mechanical stimulation of the tooth (TMTst) with initial burst discharges (latency; 14.9 +/- 8.7 ms) and sequential suppression of spontaneous discharges (duration; 218 +/- 142 ms). They also fired strongly at the onset and removal of sustained mechanical stimulation of the tooth (SMTst) with both on and off responses, but the responses for the duration of stimulation were indistinguishable from the spontaneous discharge level. Conditioning stimulation by transient mouth opening (TMOst) inhibited the on and off responses elicited by tooth pressure in 13 (56.5 per cent) of the 23 cortical neurones and in 16 (88.9 per cent) of the 18 neurones tested, respectively. On reversing the conditioning-test sequence, the response elicited by TMOst was inhibited by the onset and removal of SMTst in 12 (52.2 per cent) of the 23 neurones and in 8 (44.4 per cent) of the 18 neurones tested, respectively. The inhibitory period ranged from 50 to 250 ms.

Acute renal failure in McArdle's disease

This is a report of a case of acute renal failure associated with McArdle's disease. A 45-year-old man had acute renal failure that required dialysis. His case was subsequently diagnosed as rhabdomyolysis secondary to McArdle's disease, a primary myopathy due to myophosphorylase deficiency. History-taking revealed nothing suspected to be responsible for precipitating the renal failure.

Response fields of the periodontal mechanosensitive units in the superior alveolar nerve of the cat

Response properties of periodontal mechanoreceptor primary afferent fibers recorded from the superior alveolar nerve were studied in the cat. The left maxillary canine tooth was stimulated manually in 8 directions and/or in 24 directions in the horizontal plane by a specially designed stimulator. The responses of 328 slowly adapting units observed were affected by the direction of stimulus. These units were classified into three groups according to the shape of the response field: a broad type (more than 180 degrees), a medium type (90 degrees to 180 degrees), and a narrow type (less than 90 degrees). The groups contained 27 units (8.2%), 284 units (86.6%), and 17 units (5.2%), respectively, and the remaining 10 units (10.0%) were unclassified. The shape of each response field was little changed by changes in the stimulus intensity. Every response field investigated showed a unimodal distribution. These results were different from those of Mei et al. (1975) who reported that the response fields of units recorded from a Gasserian ganglion had generally consisted of two parts.

Transient glucose intolerance during attacks of thyrotoxic periodic paralysis

In a 19-year-old Japanese male (case 1) with thyrotoxic periodic paralysis (TPP), an increase of plasma glucose concentration together with abnormally high levels of serum immunoreactive insulin (IRI) was observed preceding a spontaneous attack of paralysis. Therefore, the plasma glucose, glucagon, epinephrine, norepinephrine, serum IRI, growth hormone and cortisol levels, and the erythrocyte insulin receptors were measured in case 1 and a 40-year-old Japanese male (case 2) with TPP during attacks of paralysis induced by prolonged glucose loading. In case 1, the serum IRI concentration was elevated to the extraordinarily high level of 655.0 microU/ml at the beginning of paralysis, and at that time, the plasma glucose concentration was 147 mg/dl. However, when paralysis was not induced by a similar glucose loading during methimazole treatment, the serum IRI and plasma glucose levels at the corresponding time after glucose loading were 20.9 microU/ml and 87 mg/dl, respectively. Furthermore, the affinity of the erythrocyte insulin receptors was decreased during the attack. In case 2, plasma glucose and serum IRI concentrations were increased in accordance with the initiation of paralysis although the blood levels of hormones counteracting insulin were not significantly changed. These findings suggest that there is something interacting with the normal action of the insulin in the early phase of paralysis.

A diurnal variation of hepatic acid cholesteryl ester hydrolase activity in the rat

The diurnal variation in lysosomal acid cholesteryl ester hydrolase (Acid CEH), (EC 3.1.1.13) has been examined in fed, fasted and adrenalectomized rats. The Acid CEH activity of normal rat liver exhibits a diurnal rhythm with maxima at 06.00 hours and minima at 18.00 hours, but such a rhythm was not observed in spleen and brain. This rhythm was abolished after fasting for two days, and the resulting Acid CEH activity remained constant at the minimum level. However, adrenalectomy did not abolish the diurnal rhythm. These results indicate that the Acid CEH activity varies according to a diurnal rhythm with maxima and minima separated by approximately 12 hr. Further, it is evident that the appearance of this rhythm is dependent upon dietary, but not adrenal hormone influence.

Experimental studies on immunogenesis of otitis media with effusion

In order to investigate otitis media with effusion from the systemic perspective, we have studied histological reactions of the mucous membrane in the both middle ears in the sensitized animals. Guinea pigs were initially immunized by injection of BSA conjugated with alum (BSA-alum) into unilateral tympanic cavity. The second challenge of BSA-alum was performed on the seventh day after primary sensitization under an appropriate schedule. The guinea pigs were sacrificed for histological examination at 3 days after the second administration. Histological changes of the middle ear mucosa in the sensitized ear were characterized by hypertrophy of mucosa with fibrosis. Numerous mononuclear cells also existed. In non-sensitized ear (opposite side), the changes were edema of the mucosa showing mild proliferation of fibroblast and vasodilation. Mainly mononuclear cells were scattered. It was noted that these reactions were weaker than those of the sensitized ear.

Quantitative determination of bacterial endotoxin in middle ear effusions by chromogenic substrate method

It is known that bacterial endotoxin on the outer surface of most gram-negative bacteria (GNB) is not only biologically active material, but also the modulator of the immune response. The earlier experiment documented that the endotoxin of killed Haemophilus influenzae was responsible for induction of chronic otitis media with effusion (OME). Recent study by DeMaria et al. determined the endotoxin of human middle ear effusion (MEE) by means of limulus amebocyte lysate assay. It was concluded the endotoxin was present in a high percentage of the effusion in human tympanic cavities. The present study was undertaken to quantitatively determine the endotoxin in human MEE by use of chromogenic substrate technique which is more sensitive and accurate than limulus assay. Sixty samples of mucoid and serous effusion were subjected to chromogenic substrate method. It was revealed that the mucoid effusion showed a significantly high level of endotoxin at 282 pg/ml in average, though the serous effusion contained only 35.9 pg/ml. It is assumed that the bacterial endotoxin may greatly contribute to the pathogenesis of otitis media with mucoid effusion.

Molecular cloning and nucleotide sequence of a variant wheat histone H4 gene

To determine whether there is structural variation among histone H4 genes in wheat, one (TH091) of the H4 genes that had been cloned from a wheat genomic DNA library was sequenced and compared with another H4 gene (TH011) which we had described previously [Tabata et al., Nucl. Acids Res. 11 (1983) 5865-5865]. Nucleotide sequence analysis revealed that there are 17 nucleotide replacements in the protein-coding region of two H4 genes, causing only one amino acid substitution: a glycine at position 4 (from the N terminus) in TH011 was replaced by an aspartic acid in TH091. S1 mapping, using total nuclear RNA from germinated seeds, indicated that the H4 gene was transcribed in vivo.

Maturational impairment of thymic lymphocytes in streptozotocin-induced diabetes in rats

Streptozotocin (STZ)-induced diabetes in rats was associated with marked decreases in thymus weight and the number of thymic lymphocytes. Histologically, the cortical lymphocytes which were present near the cortico-medullary junction in the thymus seemed to be reduced selectively in the STZ-induced diabetes. Rosette-forming cells, which bind to guinea pig erythrocytes in the presence of fetal calf serum, were also significantly decreased. Insulin treatment allayed these intrathymic changes. Preincubation of thymic lymphocytes from diabetic rats with thymosin fraction 5 significantly enhanced the percentage of rosette-forming cells to near the control level. These results suggest that a maturational impairment of thymus cortical lymphocytes may be caused in STZ-induced diabetes with hypoinsulinemia and it may be intimately related to reductions in thymus weight and the number of thymic lymphocytes.

Characterization of a cytosolic protein inhibiting lysosomal acid cholesteryl ester hydrolase

An inhibitor of lysosomal acid cholesteryl ester hydrolase (Acid CEH), (EC 3.1.1.13) was found in the cytosolic fraction of rat liver and various other tissues. The extent of the inhibitory effect was dependent on the concentration of the cytosolic protein. The Acid CEH inhibitor was heat-labile, non-dialyzable, and its inhibitory activity significantly decreased by trypsin or chymotrypsin digestion, but not by lipase digestion. The inhibitor had no effect on the activity of cathepsin D, beta-glucuronidase and acid phosphatase, which are other enzymes found in lysosomes. The present findings suggest that the inhibitor may be involved in the regulation of the hydrolysis of cholesteryl esters in lipoproteins that have been transferred into the liver.

Transcription of cloned actin genes of Dictyostelium discoideum in the cell-free system

Truncated templates of a cloned actin gene (actin 5) of Dictyostelium discoideum were transcribed in a HeLa cell extract from a position indistinguishable from the in vivo initiation site. The efficiency of this accurate transcription, however, was very low compared with that of the adenovirus 2 major late gene in the same system. Transcription of the actin 6 and 8 genes, of which the 5'-flanking regions differ in their base sequences from the corresponding region of the actin 5 gene, was not good in either fidelity or efficiency. When the partially purified RNA polymerase II of D. discoideum was used instead of the HeLa cell extract, no accurate transcription of the actin 5 gene occurred. However, simultaneous addition of RNA polymerase II and HeLa cell extract into the cell-free system caused a shift of the in vitro initiation point of transcription of the actin 5 gene to a position about 20 nucleotides downstream from the presumed in vivo initiation site. The reason for the shift remains unknown, but it is supposed that some factor(s) other than RNA polymerase II are involved in the accurate initiation of transcription and the maintenance of transcription efficiency of the actin genes.

A marked change in insulin binding to rat thymic lymphocytes by fractionation of the cells into two subsets

As compared with the pre-separated thymic lymphocyte (TL) population, a marked reduction of insulin binding was found in the two fractions [supernatant lymphocytes (SL) and precipitate lymphocytes (PL)] separated by low-speed differential centrifugation from the TL population. The reduction in insulin binding to SL or PL appeared to be due to a decrease in the affinity rather than a decrease in the number of insulin receptors. The reduced insulin binding was enhanced to near the level of the TL population when SL and PL were mixed and then incubated for 90 min at 37 degrees C. Moreover, when the cell-free supernatant from the mixed and incubated fraction was added to SL and PL respectively, the insulin binding to each fraction was found to be enhanced.

The structural organization and DNA sequence of a wheat histone H4 gene

Some wheat histone H4 genes have been cloned from a Charon 4 wheat genomic DNA library using sea urchin histone H4 DNA as a probe. DNA sequence analysis of a cloned gene showed that the deduced amino acid sequence of wheat histone H4 protein was identical to that of pea. The 5' end of wheat histone H4 mRNA was mapped on the cloned gene by the S1-procedure. Southern blotting analysis of the genomic DNA indicated that histone H4 genes were reiterated 100 to 125 times per hexaploid wheat genome.

Effects of acute exercise on insulin binding to erythrocytes in normal men

Ten normal men were subjected to acute mild and moderate exercise tests, and the insulin binding to erythrocytes was determined before and immediately after exercise and also 10, 30 and 60 minutes after exercise in each test. The insulin binding significantly increased immediately after acute moderate exercise and did not increase immediately after acute mild exercise. In contrast, it decreased below the basal level at 30 and 60 minutes in each test. The changes in insulin receptor binding were due mainly to an alteration in insulin receptor affinity rather than a change in receptor number. These results suggest that isolated erythrocytes may be of some value for study of the effect of physical exercise on the insulin receptor.

[Angiographic findings of atrophic cerebral disorders in children]

Angiographic findings of the cerebral atrophy in children are discussed. Cerebral angiographies were performed on 20 patients, ranging from 6 months to 16 years of age. Their clinical diagnoses were H-H-E syndrome (4 cases), sequelae of meningoencephalitis (2), sequelae of head trauma (3), infantile spasms (2) and others (9). Final radiological diagnoses of these cases were hemiatrophy (14 cases), generalized atrophy (2) and focal atrophy (4). Circulation time, caliber of arteries, degree of opacification in cortical and deep veins and early filling of deep veins were investigated on angiogram. Slow circulation of cerebral blood flow was shown in 10 cases and normal circulation in 10 cases. Arterial narrowing was observed more frequently in slow circulation group. In cases with hemiatrophy, small caliber of the middle cerebral arteries and slow circulation on the atrophic hemisphere were demonstrated, but no abnormality on the normal side. Deep veins were prominently opacified in cases which showed poor cortical veins, the other way cortical veins were prominent in cases which showed poor visualization of deep veins. Cortical veins and deep veins may compensate each other in cerebral venous drainage. In most cases of slow circulation, dominant opacification of deep veins were visualized and these veins already appeared in arterial phase, but cortical veins had a tendency of poor opacification. These venous drainage patterns are similar to those of Sturge-Weber syndrome. Causes of these vascular changes are unknown. But they may play an important role in cerebral atrophic disorders.(ABSTRACT TRUNCATED AT 250 WORDS)

Laminar distribution and the response of superior colliculus neurons to stimulation of the periodontal ligament in the rabbit

Unit discharges of superior colliculus neurons fired by electrical stimulation of the periodontal ligament and/or mechanical stimulation of the mandibular incisor tooth were extracellularly recorded, and their laminar distribution and response properties were examined. The neurons were widely distributed in the deep layer of the anterior two-thirds of the superior colliculus. Most of them were located in the lateral site of the profound layer, a few in the lateral site of the intermediate layer. Their locations correspond to the lower nasal quadrant of the visual field. The mean first-spike latency of the intermediate layer neurons (7.2 ms) elicited by electrical stimulation of the periodontal ligament was shorter than that of the profound-layer neurons (13.8 ms). About one-third of the neurons were suppressed by conditioning electrical stimulation of the optic chiasma. These results suggested that in addition to visual, auditory, and body surface tactile sensations, intraoral somesthetic sensations also participate in the functioning of the superior colliculus which appears to play a role in orienting the animal toward visual, somesthetic, and auditory stimuli.