Regular pulse emission in some megachiropteran bats

We recorded vocalizations of megachiropteran bats, Cynopterus brachyotis, C. horsfieldi, Megaerops ecaudatus and Macroglossus sobrinus as they were held in our hands, in a hanging position or moved up and down, simulating flight. All four species produced regular audible tone pulses with a frequency spectrum of less than 9 kHz (peak at 4-6 kHz). The duration of a single pulse varied from 14.9 to 23.6 msec on average among these species. The interpulse interval was between 108.3 and 127.7 msec. In M. ecaudatus and M. sobrinus, double pulses were occasionally emitted, with interpulse intervals averaging 39 msec and 31 msec, respectively. The regular pulse emission may indicate that the bats studied use sounds to probe space.

[Planning for brachytherapy using a 3D-simulation model]

A 3D-simulation model made with a milling system was applied to HDR-brachytherapy. The 3D-simulation model is used to simulate the 3D-structure of the lesion and the surrounding organs before the actual catheterization for brachytherapy. The first case was recurrent prostatic cancer in a 61-year-old man. The other case was lymph node recurrence of a 71-year-old woman's upper gum cancer. In both cases, the 3D-simulation model was very useful to simulate the 3D-conformation, to plan the treatment process and to avoid the risk accompanying treatment.

[Subdural abscess following chronic subdural hematoma]

This is a report of subdural abscess following chronic subdural hematoma. An 86-year-old male was admitted to our hospital due to drowsiness and left hemiparesis. He had been suffering from a spike fever which originated during chronic cholecystitis and cholelithiasis and which had continued since 2 years prior to admission. On admission, CT scans revealed right chronic subdural hematoma, and the collection of a few old hematomas was suspected in the left subdural space. An emergency removal of the right hematoma was carried out by using right single burr hole. It was found that the old hematoma accompanied a yellow-white abscess in the subdural space. Escherichia coli were detected from a bacterial culture of the abscess. Postoperative enhanced MRI clearly showed the capsule of the right subdural abscess, and the left chronic subdural hematoma. Removal of the left hematoma was performed by using a left single burr hole. But the abscess did not exist in the left subdural space, and only old hematomas had collected there. The bacterial culture of the left old hematoma was negative. Escherichia coli might be implanted on the capsule of the right chronic subdural hematoma by bacteremia derived from chronic cholecystitis. It was considered that the formation of the subdural abscess might have developed through the deterioration of the immunological function under the influence of senility.

The mechanism of interaction of sodium dodecyl sulfate with elastic fibers

Sodium dodecyl sulfate (SDS), an anionic hydrophobic ligand, is known to alter the mechanical properties of elastic fibers. In order to analyze the mechanism of the alteration, two forms of fibrous elastins, "solid" and "powder" elastins, which consisted of fascicular elastic fibers and single or oligomeric elastic fibers, respectively, were prepared from bovine aorta, and the interactions of SDS with these elastins in the presence and absence of 0.15 M NaCl were studied. The solid elastin was able to retain 1.2- to 1.4-fold larger amounts of SDS than the powder elastin under both conditions, and both elastins retained 1.2-fold or larger amounts of SDS in the presence of NaCl than in its absence. Whereas both elastins released the retained SDS gradually on repeated washing with an SDS-free buffer, the release rates from the solid elastin, especially the rate in the presence of NaCl, were much smaller than those from the powder elastin, and the solid elastin retained approximately 40% of the bound SDS under conditions where the powder elastin lost most of its SDS. The SDS-binding capacities of both elastins were significantly lower than those of soluble kappa-elastin and serum albumin, which bound SDS homogeneously on the polypeptide chains. When the washed SDS-bound solid elastin was incubated with methylene blue and examined under a microscope, most of the methylene blue-SDS complex was located at the interfiber spaces of the elastic fibers. These results suggest that SDS alters the mechanical properties of elastic fibers by binding to the interfiber spaces and surfaces of the fibers rather than by binding to the internal polypeptide chains.

Organization of the functional domains in membrane cytoskeletal protein talin

Talin, a putative homodimer of 230-kDa polypeptides, was cleaved into the N-terminal 47-kDa and C-terminal 190-kDa fragments with calpain II. The 190-kDa fragment, but not the 47-kDa fragment, was found to bind to actin. The 190-kDa fragment possessed similar levels of activities to stimulate both polymerization of G-actin and alpha-actinin-dependent gelation of F-actin as did intact talin. Limited digestions of the 190-kDa fragment with chymotrypsin and papain resulted in partial and complete reductions, respectively, of both activities, although these digests contained 95- and 46-kDa major polypeptides, respectively, which were able to bind to actin. Whereas the 190-kDa fragment generated fully cross-linked oligomeric polypeptides on treatment with 1-ethyl-3[3-(dimethylamino)-propyl]carbodiimide, the 95-kDa chymotryptic polypeptide generated heterologous polypeptides cross-linked partially with smaller polypeptides. The papain digest did not contain any cross-linkable polypeptide. Intact talin and the 47-kDa calpain fragment, but not the 190-kDa calpain fragment, were found to bind to phospholipid vesicles containing phosphatidylserine. These results indicate that the N-terminal and C-terminal domains play distinct roles in interacting with the membrane and cytoskeletal elements, respectively, and that the dimeric structure is also required for the latter interactions.

Transient expression of a brain/embryonic-type myosin heavy chain isoform (MIIB2) in regenerating rat liver

The expressions of non-muscle-type (MIIA) and brain/embryonic-type (MIIB2) myosin heavy-chain isoforms in regenerating rat liver were examined. In regenerating liver after partial hepatectomy, the level of MIIA was nearly constant, while that of MIIB2 increased transiently. The level of MIIB2 was very low in normal livers, and increased gradually and then declined with a peak at the 4th day, when the regeneration was almost completed. The level of proliferating cell nuclear antigen was highest at the 2nd day. Serine dehydratase activity in the liver decreased on partial hepatectomy, began to increase at the 5th day, and reached 71% of the control at the 7th day. These results suggest that MIIB2 plays a role in reconstruction or differentiation of the regenerating tissues rather than in proliferation of hepatocytes.

[Two cases of isolated ambient cistern hematoma after head injury]

This is a report of two cases of isolated ambient cistern hematoma after head injury. Isolated small hematomas in the ambient cistern after head injury are considered indirect evidence of brain stem injury. In such cases the initial neurological signs are often severe, but the ultimate prognosis is almost always good or excellent. Our patients showed hardly any neurological signs, and their head trauma was not very severe. Isolated ambient hematomas are the result of injury to small vessels or of mild contusions of the brain stem produced by the edge of the tentorium. In case 2, MRI revealed small, high signal intensity near the hematoma, and this sign was interpreted as evidence of mild brain stem injury. We think our patients had very mild brain injuries which were unaccompanied by diffuse axonal injury.

[A case of emergency carotid endarterectomy to cope with vertebrobasilar insufficiency]

This is a report of an emergency carotid endarterectomy preformed on a 59 year-old male. He had been suffering from TIA of vertebrobasilar insufficiency since 1 day prior to admission. Angiography revealed severe stenosis and ulceration of the left cervical carotid bifurcation and occlusion of the bilateral vertebral arteries. Six hours after angiography, he showed hemiparesis, decerebrated posture and consciousness disturbance. These neurological signs were considered to be derived from occlusion of the left carotid bifurcation and disappearance of the collateral circulation via the left posterior communicating artery. Emergency carotid endarterectomy was performed to prevent brain infarction of the anterior and posterior circulation. Postoperative angiography showed disappearance of the stenosis of the carotid bifurcation and the recanalization of the left vertebral artery, and of the atherosclerotic stenosis of the left intracranial vertebral artery. It was considered that the left vertebral artery had been occluded by growth of a local thrombosis at the left intracranial vertebral artery.

Analysis of acoustic elements and syntax in communication sounds emitted by mustached bats

Mustached bats, Pteronotus parnellii parnellii spend most of their lives in the dark and use their auditory system for acoustic communication as well as echolocation. The sound spectrograms of their communication sounds or "calls" revealed that this species produces a rich variety of calls. These calls consist of one or more of the 33 different types of discrete sounds or "syllables" that are emitted singly and/or in combination. These syllables can be further classified as 19 simple syllables, 14 composites, and three subsyllables. Simple syllables consist of characteristic geometric patterns of CF (constant frequency), FM (frequency modulation), and NB (noise burst) sounds that are defined quantitatively using statistical criteria. Composites consist of simple syllables or subsyllables conjoined without any silent interval. Most syllable types exhibit a large intrinsic variation in their physical structure compared to the stereotypic echolocation pulses. Syllable domains are defined on the basis of multiple parameters, although these can be collapsed onto three dimensions that capture 99% of the measured variation among different types of syllables. Temporal analysis of multisyllabic constructs reveals several syntactical rules for syllable transitions.

Epidemiological survey of dementia and depression among the aged living in the community in Japan

The authors surveyed the prevalence of depression and dementia in the elderly in Ohira town in Japan from 1989 to 1990. The total population of this town was 26,712, with 2,778 people aged 65 and above, constituting 10.4% of the total population. The prevalence of dementia (n = 128) was 6.1% and that of major depression (n = 9) was 0.4%, according to the DSM-III-R criteria. The prevalence of a depressive state which did not fulfill the criteria for major depression (n = 55) was 2.4%. The patients with multi-infarct dementia (n = 49) suffered from depression (42.8%) more frequently than those with dementia of the Alzheimer type (11.1%). The rate of depression coexisting with dementia increased with aging, while the rate of depression without dementia did not change in all the age groups.

Histopathology and viral antigen distribution in lymph nodes of cats naturally infected with feline immunodeficiency virus

Lymph nodes from cats with natural feline immunodeficiency virus (FIV) infection were examined histopathologically for characterization of lesions in the symptomatic and terminal stages. The localization of viral antigen was also studied in the nodes by immunohistochemistry using a monoclonal antibody to FIV p24. In a node of persistent generalized lymphadenopathy stage, follicular hyperplasia was prominent and the viral antigen was demonstrated predominantly in the follicular lymphocytes and tingible body macrophages. In cats died at AIDS related complex stage, the lymph nodes showed either mixed follicular hyperplasia and involution, involution, or mixed involution and depletion. The lymph nodes in those died at AIDS stage showed considerable destruction of the nodal architecture with involution and depletion of lymphoid follicles. In this terminal stage, the viral antigen was seen prominently in histiocytes/macrophages of the sinus. These findings observed in the dead cats were similar to the lymph node changes seen in human AIDS associated with HIV infection. It was suggested that sequential histologic changes from follicular hyperplasia to depletion via involution took place in the FIV infected lymph node with persistence of FIV antigen.

A multi-centre study of the efficacy and safety of pravastatin in hypercholesterolaemic patients with non-insulin-dependent diabetes mellitus

A multi-centre, non-randomized clinical study of 12-months' duration was performed in 112 patients with hyperlipidaemia associated with non-insulin-dependent diabetes mellitus to evaluate the clinical efficacy and tolerability of pravastatin and to assess its effect on glycaemic control. Patients were eligible for this trial if they fulfilled the following criteria; a high plasma total cholesterol level greater than 220 mg/dl associated with stable glycaemic control for at least 3-months' observation period. On entry, patients received 10 mg pravastatin per day (5 mg twice daily) for 12 months. Clinical efficacy was evaluated in 108 patients. The results showed that pravastatin induced a significant decrease in serum cholesterol level mainly with LDL-cholesterol. Total cholesterol levels were decreased significantly from 275 +/- 3 mg/dl to 222 +/- 4 mg/dl within 3 months of the start of treatment, and LDL-cholesterol decreased from 192 +/- 4 mg/dl to 137 +/- 4 mg/dl. After 12 months' treatment, total cholesterol and LDL-cholesterol levels were 216 +/- 4 mg/dl (p < 0.001) and 137 +/- 5 mg/dl (p < 0.001), respectively. HDL-cholesterol levels were increased from 51 +/- 2 mg/dl to 56 +/- 2 mg/dl at 3 months (p < 0.001) and 55 +/- 2 mg/dl at 12 months (p < 0.01). Triglyceride concentrations were also decreased from 173 +/- 11 mg/dl to 156 +/- 13 mg/dl at 3 months and 137 +/- 10 mg/dl at 12 months (p < 0.01). Fasting plasma glucose and glycated haemoglobin levels were not affected by pravastatin. Adverse events observed in 5 cases were always mild and reversible. These results indicate a clinical usefulness of pravastatin with high compliance in patients with hyperlipidaemia associated with non-insulin-dependent diabetes mellitus.

[Prospective dose-escalation study in stereotactic radiotherapy utilizing a linear accelerator: report from East Hokkaido Radiosurgery Study Group (EHRSSG)]

Stereotactic radiotherapy utilizing a linear accelerator has been investigated. (1) Radiosurgery, (2) fractionated stereotactic radiotherapy, and (3) fractionated radiotherapy followed by stereotactic boost have been performed according to pathology, size, and prognosis of diseases. Accuracy in localization of the treatment center was within one millimeter using a CT simulator. From July, 1990 to December 1992, 69 lesions in 63 patients have been treated using the stereotactic radiotherapy according to prospective dose-escalation design. Five patients have experienced transient worsening of nerve palsy or headache, but these complications were self-limited. No late radiation damage was observed over a mean follow-up period of 12.5 months. Encouraging improvements were obtained in patients with metastasis, AVM, and acoustic neurinoma although the follow-up period was too short to be conclusive. Stereotactic radiotherapy utilizing a linear accelerator is thus suggested as a safe and effective approach providing that dose-volume-time relationship is well controlled.

Pharmacological studies on a new dihydrothienopyridine calcium antagonist. 3rd communication: antihypertensive effects of S-(+)-methyl-4,7-dihydro-3-isobutyl-6-methyl-4-(3-nitrophenyl)thieno[2, 3-b] pyridine-5-carboxylate in hypertensive rats and dogs

Hypotensive and antihypertensive effects of S-312-d (S-(+)-methyl-4,7-dihydro-3-isobutyl-6-methyl-4-(3-nitrophenyl)thieno[2, 3- b]pyridine-5-carboxylate, CAS 120056-57-7) in Wistar Kyoto rat (WKY), spontaneously hypertensive rat (SHR), stroke-prone SHR (SHRSP), and DOCA-salt hypertensive rat (DOCA-HR) were compared with those of other representative calcium antagonists. The minimal effective hypotensive dose of S-312-d in WKY was 3 mg/kg p.o. and those in SHR, SHRSP, and DOCA-HR were 1 mg/kg p.o. in gum arabic suspension. The minimal antihypertensive dose of S-312-d in polyethylene glycol solution was 0.3 mg/kg p.o. in SHRSP. The antihypertensive effects of S-312-d was the most potent and long-lasting compared with the calcium antagonists, nifedipine, nicardipine, nimodipine, nilvadipine, and flunarizine. In conscious two-kidney Goldblatt-type hypertensive dogs, a significant antihypertensive effect and concomitant increases of heart rate with S-312-d at 1 mg/kg lasted for 4 to 6 h after oral administration. Determination of the plasma concentration of S-312-d by HPLC showed that more than 4.3 ng/ml of S-312-d is required for a significant antihypertensive effect. Subcutaneous administration of atenolol at 20 mg/kg 30 min before S-312-d significantly inhibited the tachycardia with S-312-d at 1 mg/kg p.o. but not its antihypertensive effect. S-312-d is considered useful for the treatment of essential hypertension and related organ disorders.

Pharmacological studies on a new dihydrothienopyridine calcium antagonist. 1st communication: comparative studies on the cardiovascular effects of methyl-4,7-dihydro-3-isobutyl-6-methyl-4-(3-nitrophenyl)thieno[2,3- b]pyridine-5-carboxylate and its two enantiomers in experimental animals

Antihypertensive effects in conscious spontaneously hypertensive rats (SHR), cardiovascular effects in anesthetized dogs, and calcium antagonistic effects in the rabbit isolated basilar arteries and guinea-pig isolated coronary arteries of S-312 (methyl-4,7-dihydro-3-isobutyl-6-methyl-4- (3-nitrophenyl) thieno [2,3-b] pyridine-5-carboxylate) and its two enantiomers were comparatively investigated. The antihypertensive effect in SHR and hypotensive effect in anesthetized dogs of S-312-d (CAS 120056-57-7) were approximately 2 times more potent than those of S-312, but these effects of S-312-l were very weak even at 10 to 100 times higher doses. Increases of vertebral blood flow in dogs with S-312 and S-312-d were almost corresponding. The IC50 concentrations of S-312-d, S-312, S-312-l in the rabbit isolated basilar arteries contracted with high K+ solution were 1.4 x 10(-10) mol/l, 2.2 x 10(-10) mol/l, and 4.6 x 10(-9) mol/l, respectively. The relaxing effect of S-312-d in the isolated coronary arteries was most potent, followed by those of S-312 and S-312-l. It is concluded that the cardiovascular and calcium antagonistic effect of S-312-d are mainly responsible for those effects of S-312.

Increases in protein phosphatase 2B activity in lymphoid tissues and T-lymphocytes of autoimmune MRL/MpJ-lpr/lpr mice

The assay conditions for protein phosphatase 2B (PP2B) in crude extracts from mouse lymphoid tissues and lymphocytes were extensively investigated. Under the conditions elucidated, the PP2B activity was measured in autoimmune-prone MRL/MpJ-lpr/lpr mice (MRL/lpr mice) and two control strains, MRL/MpJ- +/+ mice (MRL/+/+ mice) and C3H/HeJ mice. In the control mice, PP2B activity was distinctly higher in spleen and thymus than brain and liver. PP2B activity was further elevated in spleen of MRL/lpr mice than in the controls. Furthermore, we observed a specific increase in PP2B activity in T lymphocytes from MRL/lpr mice as compared with in those from control mice. On the other hand, no alteration was observed in PP2B activity in B lymphocytes. These results suggest the involvement of PP2B in the abnormal signal transduction and proliferation of T lymphocytes in MRL/lpr mice.

Pathologic features of acquired immunodeficiency-like syndrome in cats experimentally infected with feline immunodeficiency virus

Five specific pathogen free cats were inoculated with feline immunodeficiency virus (FIV) isolated in Japan to observe changes toward development of acquired immunodeficiency syndrome (AIDS)-like disease. All inoculated cats had lymphadenopathy and mild respiratory disease shortly after inoculation. Following the initial acute phase lasting for more than 40 weeks, the clinical signs gradually diminished in three animals, and the asymptomatic carrier (AC) stage was observed at 45 (1 cat) and 70 (2 cats) weeks postinoculation (p.i.). Two of the three cats developed respiratory signs and diarrhea at 105 or 106 weeks p.i. One cat died at 121 weeks p.i. with severe wasting, with necropsy findings consistent with AIDS-related complex (ARC). The others were surviving at 150 weeks p.i. with mild clinical signs or asymptomatic. Another group of two cats developed more severe illness without the AC phase. One died at 48 weeks p.i. with the ARC illness. The other cat developed marked emaciation with diarrhea at 75 weeks p.i., and died at 100 weeks p.i. with a histologic diagnosis suggestive of terminal immunodeficiency. Histologically, the lymph nodes showed serial changes toward the terminal illness, from follicular hyperplasia at the acute phase to the lymphoid depletion at the ARC and AIDS-like terminal stages. The FIV antigen was demonstrated in the lymph nodes. The virus was isolated from peripheral blood mononuclear cells of all the inoculated animals. These data demonstrated possible etiologic association of FIV with development of AIDS-like disorders in the cat.

Heavy-chain isoforms of non-muscle myosin in human tissues

The heavy-chain isoforms of myosin in human non-muscle and smooth muscle tissues were analyzed by means of SDS/PAGE and using three distinct newly developed monoclonal anti-(human cerebrum myosin) Ig (HBM-1, HBM-3 and HBM-4). Purified cerebrum myosin contained three electrophoretic variants of non-muscle myosin heavy chain (NM1, NM2 and NM3, with apparent molecular masses of about 200, 198 and 196 kDa, respectively). Both NM1 and NM2 were recognizable by the brain-specific antibody HBM-1, while NM3 was recognizable by HBM-3. Each of the variants reacted with HBM-4 to a similar extent. Purified cerebellum myosin gave three electrophoretic variants of the heavy chain which were indistinguishable electrophoretically or immunologically from those of cerebrum myosin. Aortic myosin contained four electrophoretic variants, including the two smooth muscle myosin heavy chain isoforms and NM2-like and NM3-like heavy chains. Liver, platelet and kidney myosins contained a heavy chain very similar to NM3. Kidney myosin also contained a small fraction of an NM2-like electrophoretic variant. In addition, cerebrum, kidney, liver and platelet myosins appeared to contain minor, 194-kDa myosin heavy-chain-like polypeptide(s) (NM4). NM1, as well as NM2 and NM3, thus appear to be the brain-type and non-brain-type non-muscle myosin heavy-chain isoforms, respectively, and additional minor heavy-chain isoforms are also likely to be present in human tissues.

Long-term clinical observations on feline immunodeficiency virus infected asymptomatic carriers

Eleven feline immunodeficiency virus (FIV) infected asymptomatic carrier (AC) cats were observed for 2 years for development of acquired immunodeficiency syndrome (AIDS). Four of the 11 (36.4%) showed progression of the clinical stage. Persistent generalized lymphadenopathy was noted in three cats as the first sign of illness after the AC phase, while the other showed lymphadenopathy with signs of AIDS-related complex. In all four cats the AIDS-related complex stage lasted for 10 months or longer, and two showed progression of the disease into AIDS. The two cats showing AIDS illnesses died within approximately 1 year after they had developed persistent generalized lymphadenopathy. Pathology confirmed the diagnosis of AIDS characterized by the presence of depletion lesions in the lymphoid organs, and of severe infections of an opportunistic nature. The overall mortality of FIV infected AC cats during a 2 year period was two out of 11 (18.2%). These cats showed decreased concanavalin A mitogen response of peripheral blood mononuclear cells as the disease progressed.

Comparative studies on the extractability of collagen from aortas of stroke-prone spontaneously hypertensive and normotensive rats

The molecular states of collagen in the aortas of age-matched stroke-prone spontaneously hypertensive (SHRSP) and normotensive Wistar Kyoto rats (WKY) were studied by analyzing its extractability under defined conditions. The monomeric and oligomeric collagen extractable with 0.5 M acetic acid/6 M urea from aortic homogenates of 9-month-old SHRSP and WKY comprised approx. 0.6 and 2.0%, respectively, of the total collagen. On incubation of the acetic acid/urea-extracted residues with pepsin at 4 degrees C, the levels of the collagen alpha 1(I) and alpha 2(I) chains solubilized from the SHRSP residues were both less than 50% of those from the WKY residues. When the residues were incubated with pepsin at 15 or 25 degrees C, the differences became smaller. When the acetic acid/urea residues were hydrolyzed with cyanogen bromide, nearly identical peptide maps were obtained for SHRSP and WKY. The aortas from 2-month-old SHRSP and WKY contained much larger proportions of acid/urea-extractable collagen than those of the older rats (8.2 and 13% of the respective total collagen). The levels of the alpha 1(I) and alpha 2(I) chains solubilizable from the respective residues by pepsin at 4 degrees C were similar to each other. These results indicate that aortic collagen fibrils in SHRSP are stiffened more prominently than those in WKY.

Augmentation of alpha-actinin-induced gelation of actin by talin

Interactions among the three major constituents of focal adhesions, talin, actin, and alpha-actinin, were studied. No evidence was obtained for the direct interaction between talin and alpha-actinin. Both talin and alpha-actinin increased the rate and extent of polymerization of actin, and their effects were additive. Whereas talin alone exhibited very little actin-gelating activity, it potentiated markedly the gelation in the presence of alpha-actinin and lowered the concentration of alpha-actinin necessary for the gel formation. Its gelation-potentiating activity on prepolymerized actin was much smaller than observed on G-actin. Treatment of talin with a cross-linking reagent, 1-ethyl-3[3-(dimethylamino)propyl]carbodiimide or dimethyl suberimidate, resulted in the formation of its oligomeric polypeptides. The complexes of talin and G-actin were also demonstrated with the cross-linking reagents and fluorescence-labeled actin. These results indicate that talin is able to cross-link some limited regions of actin filaments.