Assessment of autonomic nervous function by power spectral analysis of heart rate variability in the horse

We studied power spectral analysis of heart rate (HR) variability in the horse, with the hypothesis that the quantitative information provided by the spectral analysis of HR variability reflects the interaction between sympathetic and parasympathetic regulatory activities. For this purpose, electrocardiogram, blood pressure (BP) and respiratory (Resp) waveform were simultaneously recorded from Thoroughbred horses (3-5 years old) and analyzed by power spectrum. There were two major spectral components at low-frequency (LF) and high-frequency (HF) bands for HR variability. The peak of Resp variability clearly occurred at the HF range. In contrast to Resp variability, the power spectra of BP variability occurred at lower frequencies. The maximum coherence between HR and Resp variabilities and HR and BP variabilities occurred at approximately 0.15 and approximately 0.03 Hz, respectively. These relationships were similar to the ensemble spectra. On the basis of these data, we have defined two frequency bands of interest: LF (0.01-0.07 Hz) and HF (0.07-0.6 Hz). Therefore, we believe that power spectral analysis of HR variability provides a very powerful technique for assessing autonomic nervous activity in the horse.

Natural history and left ventricular response in chronic aortic regurgitation

This study was aimed at clarifying the natural history and left ventricular response in aortic regurgitation using M-mode echocardiography. We analyzed the history and echocardiographic data on 94 patients, who were divided into 4 stages according to symptoms. The duration of the asymptomatic period, which represents pure volume overload, is long, and the period of minimal symptoms, combined volume and pressure overload, is relatively short. Patients with overt heart failure due to impaired contractility can survive longer than is usually believed, and the factor that predicted the onset of heart failure was a decrease in fractional shortening > 3.8 percentage points.

Thrombin potently stimulates cytokine production in human vascular smooth muscle cells but not in mononuclear phagocytes

Thrombosis frequently occurs during atherogenesis and in response to vascular injury. Accumulating evidence supports a role for inflammation in the same situation. The present study therefore sought links between thrombosis and inflammation by determining whether thrombin, which is present in active form at sites of thrombosis, can elicit inflammatory functions of human monocytes and vascular smooth muscle cells (SMCs), two major constituents of advanced atheroma. Human alpha-thrombin (EC50, approximately equal to 500 pmol/L) potently induced interleukin (IL)-6 release from SMCs. The tethered-ligand thrombin receptor appeared to mediate this effect. Furthermore, alpha-thrombin also rapidly increased levels of mRNA encoding IL-6 and monocyte chemotactic protein-1 (MCP-1) in SMCs. In contrast, only alpha-thrombin concentrations of > or = 100 nmol/L could stimulate release of IL-6 or tumor necrosis factor-alpha (TNF alpha) in peripheral blood monocytes or monocyte-derived macrophages. Lipid loading of macrophages did not augment thrombin responsiveness. Likewise, only alpha-thrombin concentrations of > or = 100 nmol/L increased levels of IL-6, IL-1 beta, MCP-1, or TNF alpha mRNA in monocytes. Differential responses of SMCs and monocytes to thrombin extended to early agonist-mediated increases in [Ca2+]i. SMCs and endothelial cells, but not monocytes, contained abundant mRNA encoding the thrombin receptor and displayed cell surface thrombin receptor expression detected with a novel monoclonal antibody. Thus, the level of thrombin receptors appeared to account for the differential thrombin susceptibility of SMCs and monocytes. These data suggest that SMCs may be more sensitive than monocytes/macrophages to thrombin activation in human atheroma. Cytokines produced by thrombin-activated SMCs may contribute to ongoing inflammation in atheroma complicated by thrombosis or subjected to angioplasty.

Castleman disease in the anterior neck: the role of Ga-67 scintigraphy

A case of Castleman disease in the anterior cervical region is presented. Ga-67 scintigraphy revealed moderate uptake in the thyroid region. Thyroid scintigraphy demonstrated the presence of an extrinsic thyroid tumor. Contrast-enhanced CT showed dense homogeneous enhancement within, the tumor. Radionuclide tracer accumulation on gallium scintigraphy as well as dense contrast enhancement on CT scan may be characteristic of Castleman disease. Castleman disease should be considered in the differential diagnosis when increased tracer activity is noted in an anterior cervical extrathyroid tumor on Ga-67 scintigraphy.

[Pseudoradicular sensory impairment caused by parietal lesions: report of two cases]

Here we report two cases of pseudoradicular sensory impairment (PRSI) caused by cerebral infarctions. Case on was a 49-year-old male who presented with dysesthesia in the left ulnar nerve distribution, and case 2 was a 57-year-old male who developed dysesthesia and weakness in the left radial nerve distribution. In both cases, the symptoms began with dysesthesia, followed by disturbance of cortical sensation, and distal motor weakness of the left upper extremity. Although the temperature, superficial pain, tactile, and vibratory sensations were well preserved, position sense, and cortical sensations such as two-point discrimination, material discrimination and stereognostic sensations were severely disturbed. No abnormalities were found in nerve conduction studies or cervical magnetic resonance imaging (MRI). Findings of somatosensory evoked potential (SEP) indicated that cortical components (N20, P24, N35 and P55) were missing in the left ulnar nerve in case 1, and in the median nerve in case 2. MRI of the brain revealed cerebral infarctions in the right parietal lobe including the postcentral gyrus. From the above results sensory disturbances of these two cases are caused by infarctions of the right parietal lobe. The characteristics of sensory disturbances caused by parietal lesions in our cases are similar to the previous reports. In addition, we found that the impaired cortical and subcortical areas were larger than the predicted areas indicated by Penfield's somatosensory homunculus. From the thermography, we found that the dermal regions with sensory impairment were more or less hypothermal. This suggests that cortical and subcortical infarctions may lead to localized sympathetic dysfunctions of the skin.

Idebenone improves cerebral mitochondrial oxidative metabolism in a patient with MELAS

We report a 36-year-old man with MELAS in whom a 5-month course of high-dose oral idebenone, a derivative of coenzyme Q10, increased markedly cerebral metabolic ratio of oxygen and oxygen extraction fraction without increased cerebral blood flow with PET. The results indicate that idebenone improves mitochondrial oxidative metabolism in the brain and suggest a therapeutic potential of idebenone for MELAS.

Novel approach for determination of correlation between in vivo and in vitro dissolution using the optimization technique

A new approach to determination of good correlations between in vivo and in vitro dissolution was studied using the optimization technique. Ibuprofen, which exhibits dissolution rate-limiting absorption, was used as a model drug. Ibuprofen capsules of two different release types were prepared, and their in vivo dissolution profiles were obtained from measurements of plasma concentration following oral administration of the capsules to beagle dogs by the mathematical deconvolution method using solution data of oral administration as a weight function. For the dissolution test to correspond to the in vivo dissolution profiles, the test was carried out at 12 levels (9 different sets of conditions) and results were analyzed with the optimization technique to deal with two factors. The first-order rate constant (kappa d) and the dissolution time at 50% (t50%) of the in vivo dissolution were selected for use as the response variables. Regression analysis was performed to describe the in vitro dissolution characteristics as functions of the pH of dissolution medium and paddle rotation speed in the paddle method. The in vivo/in vitro correlation obtained from the kappa d was better than that obtained from the t50%. The optimum conditions for dissolution testing corresponding to the in vivo kappa d were determined to be a pH 6.6 for the dissolution medium and a 56 rpm paddle rotation rate. The experimental data obtained by dissolution testing was well fit by the predicted curve derived from in vivo and in vitro dissolution profiles. This dissolution test is applicable to the formulations containing ibuprofen of particle size within the experimental range.

Evaluation of the brain uptake properties of [1-11C]labeled hexanoate in anesthetized cats by means of positron emission tomography

Positron emission tomography (PET) was performed on the cat brain to characterize [1-11C]hexanoate and other [1-11C]labeled short and medium-chain fatty acids as a tracer of fatty acid oxidative metabolism. After an intravenous injection the brain uptake of [1-11C]hexanoate reached a peak followed by rapid washout until 2 min (first phase). Subsequently the total brain uptake was again increased and reached to a peak 7-10 min after tracer injection (second phase). The blood radioactivity of unmetabolized [1-11C]hexanoate was rapidly decreased and almost eliminated within the first 2 min, whereas the blood radioactivity of [11C]CO2/HCO3- was gradually increased and reached a peak approximately 5 min after tracer injection. As the effect of circulating [11C]CO2/HCO3- was examined by a bolus intravenous injection of [11C]CO2/HCO3-, the brain uptake of [11C]CO2/HCO3- was rapidly increased right after the injection and changed parallel to the blood level of [11C]CO2/HCO3-. These results suggest that, in contrast to the previous mouse data, the time-activity curve in the cat brain following intravenous injection of [1-11C]hexanoate has a biphasic pattern, the second phase being determined by peripherally originating [11C]CO2/HCO3-, and therefore does not reflect the metabolism of 11C-labeled fatty acid in the brain.

MR imaging of pituitary adenomas with sphenoid sinus invasion: characteristic MR findings indicating fibrosis

We reviewed MR images obtained before and after the injection of Gd-DTPA in six patients with pituitary adenoma extending into the sphenoid sinus, and correlated the imaging and histological findings. The portion of each adenoma involving the sphenoid sinus and sellar floor was less intense on both T1- and T2-weighted spin-echo images and Gd-enhanced images when compared with the sellar/suprasellar solid portion of the adenoma, which showed marked contrast enhancement. Histological examination of adenoma specimens taken from the sphenoid sinus demonstrated abundant collagen fibers between the adenoma cells, whereas tumor tissue from the suprasellar region showed no fibrotic change. We concluded that pituitary adenomas seem to have a tendency to develop fibrosis on extension into the sphenoid sinus.

Regional difference in cerebral blood flow and oxidative metabolism in human cortex

We sought to determine if there are regional differences in cerebral blood flow (CBF) and cerebral metabolic ratio for oxygen (CMRO2) in normal subjects during the resting state.

METHODS

Regional CBF, CMRO2 and oxygen extraction fraction (OEF) in 15 normal volunteers (mean age 58.8 +/- 8.2 yr) were measured during rest using PET and a 15O-gas steady-state technique.

RESULTS

CBF and CMRO2 in the visual cortex were significantly higher than those in other cortices. Additionally, OEF in the sensorimotor cortex was significantly lower than that in other cortical regions.

CONCLUSION

CBF and CMRO2 in the visual cortex are always high, and low OEF in the sensorimotor cortex exists even in resting state in normal subjects. We hypothesize that these regional functional differences would result in different resistances to degeneration.

Nasal growth in complete bilateral cleft lip and palate

Forty-four lateral cephalograms from a sample of 15 white males with bilateral cleft lip and palate (BCLP) were evaluated to determine the growth pattern of the nose, identify timing of the nasal growth spurt, assess growth of the underlying bony elements relative to the nasal growth, and ascertain the relationship of the nose to the rest of the facial profile. The cephalograms (taken at ages 7.5 to 16.6 years) were divided into five groups according to age of subject. Fifteen variables related to soft tissue nose, nasal bone, maxilla, and facial convexity were assessed. Results of this investigation were as follows. First, the nose of subjects with BCLP grew more downward than forward. Second, the growth spurt occurred between the ages of 12 and 16 years. Third, forward growth of the nose was almost always found, whereas the maxilla becomes more retrusive. Fourth, the angle of soft tissue nasion (N')-pronasale (Prn)-soft tissue pogonion (Pog') had an average decrease of 3.56 degrees from age 8 to 16 years. Individual data showed that 12 of 15 patients had a decrease of this angle, whereas 3 had a small increase; 10 of 12 with a decrease demonstrated an increase of both sella-nasion (SN')-Prn and SN'-Pog'. The remaining 2 showed an increase of SN'-Prn and a decrease of SN'-Pog'. Thus, the profile of the nose (N'-Prn-Pog') became more convex over the observed period, which at least in part seemed to be due to the horizontal development of the nose itself.

[A monkey chair specially designed for ophthalmic examinations and intraocular pressure measurement in the conscious cynomolgus monkey]

We constructed a monkey chair specially designed for ophthalmic examinations such as biomicroscopic examination, applanation tonometry etc. It was made of stainless steel and acrylic plastic, equipped with a protection plate for the experimenter, and adjustable to the size of the monkey. Using this chair, intraocular pressure (IOP) measurements of a fully conscious cynomolgus monkey were carried out at intervals of one or two hours from 10:00 AM to 10:00 PM. The IOP, at 6:00, 8:00 or 10:00 PM was compared with the IOP measured at the same time of the day after one or two weeks. The IOP while fully conscious showed diurnal variation (p < 0.001, ANOVA). The IOP measured at the same time of the day at one or two week intervals showed reasonable reproducibility.

Decreased medial temporal oxygen metabolism in Alzheimer's disease shown by PET

In mild-to-moderate Alzheimer's disease, previous PET studies failed to reveal significant involvement in the medial temporal lobe having pathologically neurodegenerative changes. The purpose of this study was to clarify the medial temporal perfusion and functional changes in mild-to-moderate Alzheimer's disease using PET.

METHODS

Sixteen patients with probable mild-to-moderate Alzheimer's disease (age 62.9 +/- 6.0 yr, MMSE 17.7 +/- 3.7) and 14 normal volunteers (age (60.9 +/- 5.9 yr) were studied. Regional cerebral blood flow (CBF), oxygen metabolism (CMRO2) and oxygen extraction fraction (OEF) were measured using 15O steady-state method and PET. By rendering magnetic resonance volumetry of the medial temporal structures, the significance of partial volume effects on PET study measurements was examined.

RESULTS

The mean CMRO2 in the medial temporal, as well as in the parietal and lateral temporal cortices were significantly lower in the patient group than in the control group. The mean CBF in the parietal and lateral temporal cortices also significantly decreased in the patient group. The OEF in the medial temporal was also decreased in the Alzheimer's disease group, while the OEF in the other cortical regions in Alzheimer's disease group were similar to that of control group. Decline of medial temporal oxygen consumption was the most distinctive feature of Alzheimer's disease. Those measurements were independent from volume of medial temporal structures. In Alzheimer's disease, medial temporal CMRO2 and CBF correlated with some of the nonverbal memory test scores and cognitive impairment scales, when normalized for individual difference.

CONCLUSION

Medial temporal oxygen metabolism was markedly affected in patients with mild-to-moderate Alzheimer's disease. This measure substantiated the functional impairment of the medial temporal region in Alzheimer's disease.

Infusions of pressor agents selectively attenuate depressor responses to ACh in anesthetized dogs

In dogs anesthetized with pentobarbital sodium (30 mg/kg iv), infusions of phenylephrine (PE; 1-3 micrograms.kg-1.min-1 iv for 30 min and longer) caused sustained elevations in blood pressure and suppressed depressor responses to acetylcholine (ACh; 1 microgram/kg iv) in a dose- and time-dependent manner. The dose-response curve for ACh (0.01-100 micrograms/kg iv)-induced depressor responses was shifted to the right by approximately 80-fold after an intravenous infusion of PE (3 micrograms.kg-1.min-1) for 120 min. Similar suppression was observed when infusions of methoxamine (5 micrograms.kg-1.min-1 iv), norepinephrine (3 micrograms.kg-1.min-1 iv under blockade of beta-adrenoceptors), or angiotensin II (0.3 micrograms.kg-1.min-1 iv) were carried out. However, in dogs treated with prazosin (1 mg/kg iv) or hydralazine (1 mg/kg iv) to prevent elevations in blood pressure over the baseline level, PE (3 micrograms.kg-1.min-1 iv) failed to attenuate depressor responses to ACh. The suppression observed after PE infusion was specific to ACh-induced depressor responses; i.e., no suppression was observed on the depressor responses to other drugs, such as histamine, sodium nitroprusside, carbachol, and methacholine. Furthermore, neostigmine (bolus injection of 30 microgram/kg iv followed by an infusion of 15 micrograms.kg-1.h-1 iv) greatly diminished the suppressive effect of PE. Except for a slight increase in acetylcholinesterase (AChE) activity in renal arterial segments, activities of both AChE and butyryl-cholinesterase in plasma, erythrocytes, and pulmonary and renal arterial segments were unchanged after PE infusion. These results suggest that prolonged elevation in blood pressure and/or vasoconstriction selectively attenuates depressor responses to ACh through accelerated degradation of this material.

Prevention of mammary tumorigenesis in acatalasemic mice by vitamin E supplementation

Adult male and female acatalasemic (C3H/AnLCsbCsb),hypocatalasemic (C3H/AnLCscCsc) and normal mice of C3H strain fed on regular laboratory chow for 15 months showed an increased incidence of spontaneous mammary tumor in the decreasing order of female acatalasemic, male acatalasemic, female hypocatalasemic and male hypocatalasemic mice. Normal mice did not develop mammary tumor. We conducted a prospective study with female acatalasemic mice, which showed the highest incidence of mammary tumor, to examine the preventive effect of vitamin E on mammary tumor. Female acatalasemic mice were fed on vitamin E-deficient (28 animals) and vitamin E-supplemented diet (25 animals) for 29 months. The incidence of mammary tumor in mice given the vitamin E-supplemented diet was 47%, while that in mice given vitamin E-deficient diet was 82% (P < 0.002). Mammary tumors were apparent after 9 months of vitamin E deprivation and after 14 months of vitamin E supplementation. Female normal mice did not develop mammary tumor during a comparable period of time. The mean catalase activity of mammary gland in acatalasemic mice was 18.8% of that in normal mice. The results indicate that vitamin E protects acatalasemic mice against the development of mammary tumor.

Effect of boiled barley-rice-feeding in hypercholesterolemic and normolipemic subjects

Barley contains approximately 10% dietary fiber and is easily cooked with rice, the dominant cereal in Japan, to increase the intake of dietary fiber. This research involved three experiments to examine the influence of barley on blood lipids in human subjects. All subjects received a boiled barley-rice (50/50 w/w mix) supplement two times per day in place of rice for 2 or 4 weeks. In the normolipemic subjects, serum lipids were unaffected by the ingestion of barley for 4 weeks. In twenty hypercholesterolemic men aged 41 +/- 5 years, the ingestion of barley was associated with a significant fall in serum total cholesterol, LDL-cholesterol, phospholipids and LDL and VLDL-lipoproteins. In seven mildly hypercholesterolemic women aged 56 +/- 7 years, a significant improvement of serum lipid profiles was observed. The present study suggests the possibility that the ingestion of barley-rice could lower serum lipids in hypercholesterolemic subjects.

[Autoradiographic studies of oxalate distribution in rat kidney]

BACKGROUND

We performed macro and micro-autoradiographic studies using 14C-oxalate in normal and hyperoxaluric rats in order to elucidate intrarenal distribution of oxalate and to determine where calcium oxalate crystal can be adhere in the kidney.

METHODS

Macro and micro-autoradiographic studies of the kidney in normal rats were carried out at intervals of 15, 30 and 90 min after intravenous administration of 14C-oxalate (37 MBq/kg BW). Hyperoxaluria was induced by vitamin B6 deficient diet. The procedure of macro and micro autoradiography is the same as that in normal rat.

RESULTS

In normal rats, macroautoradiogram showed that the radioactivity of 14C-oxalate exists in the whole kidney, and microautoradiogram identified this radioactivity mainly in the extraluminal space of renal tubules at 15 min. Macro and micro-autoradiograms taken 90 min after the injection showed practically no radioactivity of 14C-oxalate in the cortex or the medulla, but it was located in the extraluminal space of the papilla. In hyperoxaluric rats, macroautoradiogram showed some spotty accumulations of 14C-oxalate in the inner medulla and papilla. Microautoradiogram revealed that these accumulations are mainly seen in the extraluminal space.

CONCLUSION

These results indicate that in normal rats the injected 14C-oxalate remains in the renal papilla, especially in the extraluminal space, when nearly all oxalate was excreted by urine, and in hyperoxaluric rats 14C-oxalate exists there as calcium oxalate crystal or microlith.

PET analysis of a case of cerebrotendinous xanthomatosis presenting hemiparkinsonism

We describe a 34-year-old Japanese woman presenting gait difficulty and Achilles tendon swelling. The patient was diagnosed as having cerebrotendinous xanthomatosis (CTX) based on the high serum cholestanol level and diminished enzymatic activity of 27-hydroxylase of fibroblasts from her skin. Her clinical presentation was atypical regarding the presence of hemiparkinsonism and absence of apparent cataract, dementia, and cerebellar ataxia. Although MRI studies could not detect any abnormality in the basal ganglia or midbrain, PET analysis using [18F]-6-fluoro-L-dopa revealed reduced uptake of dopamine into the putamen, suggesting the impairment of presynaptic dopaminergic neurons.

A brain uptake study of [1-(11)C]hexanoate in the mouse: the effect of hypoxia, starvation and substrate competition

We evaluated the potential of sodium [1-(11)C]hexanoate (11C-HA) as a radiopharmaceutical with which to assess oxidative metabolism of the brain by PET. 11C-HA, sodium [1-(14)C]acetate and [3H]deoxyglucose were simultaneously injected into mice under control, hypoxic and starving conditions. In the control, the brain uptake of 11C was maximal at 3 min (% ID/g = 2.2-2.5), being twice as high as that of 14C, followed by a gradual clearance. The time-radioactivity curve of 11C was similar to that of 14C. Hypoxia enhanced the brain uptake of 3H, but not of either 11C or 14C. Starvation enhanced the brain uptake of 3H and 11C. The clearance rate of 11C was not significantly affected by either condition. In the control brain at 3 min postinjection of HA, 65% of the total radioactivity was detected as labeled glutamate and glutamine, which was gradually decreased by 47% at 30 min. The brain to blood ratios of 11C-HA at 3 min were significantly reduced by butyrate, hexanoate and octanoate loading but not by that with other monocarboxylic acids or ketone bodies.

Conserved structure and adjacent location of the thrombin receptor and protease-activated receptor 2 genes define a protease-activated receptor gene cluster

BACKGROUND

Thrombin is a serine protease that elicits a variety of cellular responses. Molecular cloning of a thrombin receptor revealed a G protein-coupled receptor that is activated by a novel proteolytic mechanism. Recently, a second protease-activated receptor was discovered and dubbed PAR2. PAR2 is highly related to the thrombin receptor by sequence and, like the thrombin receptor, is activated by cleavage of its amino terminal exodomain. Also like the thrombin receptor, PAR2 can be activated by the hexapeptide corresponding to its tethered ligand sequence independent of receptor cleavage. Thus, functionally, the thrombin receptor and PAR2 constitute a fledgling receptor family that shares a novel proteolytic activation mechanism. To further explore the relatedness of the two known protease-activated receptors and to examine the possibility that a protease-activated gene cluster might exist, we have compared the structure and chromosomal locations of the thrombin receptor and PAR2 genes.

MATERIALS AND METHODS

The genomic structures of the two protease-activated receptor genes were determined by analysis of lambda phage, P1 bacteriophage, and bacterial artificial chromosome (BAC) genomic clones. Chromosomal location was determined with fluorescent in situ hybridization (FISH) on metaphase chromosomes, and the relative distance separating the two genes was evaluated both by means of two-color FISH and analysis of YACs and BACs containing both genes.

RESULTS

Analysis of genomic clones revealed that the two protease-activated receptor genes share a two-exon genomic structure in which the first exon encodes 5'-untranslated sequence and signal peptide, and the second exon encodes the mature receptor protein and 3'-untranslated sequence. The two receptor genes also share a common locus with the two human genes located at 5q13 and the two mouse genes at 13D2, a syntenic region of the mouse genome. These techniques also suggest that the physical distance separating these two genes is less than 100 kb.

CONCLUSIONS

The fact that the thrombin receptor and PAR2 genes share an identical structure and are located within approximately 100 kb of each other in the genome demonstrates that these genes arose from a gene duplication event. These results define a new protease-activated receptor gene cluster in which new family members may be found.

Role of the nondominant hemisphere and undamaged area during word repetition in poststroke aphasics. A PET activation study

BACKGROUND AND PURPOSE

Although the resting regional cerebral blood flow (rCBF) in aphasic patients has been thoroughly investigated with positron emission tomography (PET) and single-photon emission CT, and PET studies in normal subjects have elucidated the functional localization of language processing, little is known about the activation pattern of language processing in aphasic patients.

METHODS

We measured the changes in rCBF during a repetition task (hearing a single word and repeating it aloud) and the resting state using the H2(15)O PET activation technique in 6 normal subjects (mean +/- SD age, 58.3 +/- 8.1 years) and 16 aphasic patients: 10 fluent aphasics (age, 60.3 +/- 12.5 years) and 6 nonfluent aphasics (age, 50.5 +/- 8.3 years).

RESULTS

In normal subjects, the posteroinferofrontal area (PIF) including Broca's area, the posterosuperotemporal area (PST) including Wernicke's area, the rolandic areas, and a few other areas were activated with left side dominance by the repetition task. In the resting state, the rCBF in the left PIF and the left posterotemporal area was reduced in both fluent and nonfluent aphasics. In aphasic patients, the magnitude of activation in the right PIF and PST by the repetition task was greater than in normal subjects. The increase in rCBF during the repetition task in the left PIF correlated with the Western Aphasia Battery score of spontaneous speech in the nonfluent aphasics with a left inferofrontal lesion.

CONCLUSIONS

This study shows the importance in aphasic patients of the mirror regions of the left PIF and PST in the nondominant (right) hemisphere for performing the word repetition task. The results also show the importance for nonfluent aphasic patients of the recruitment of the undamaged PIF for spontaneous speech.

In vitro regeneration of Alnus cremastogyne Burk from epicotyl explants

Multiple shoots were grown from seedling explants of Alnus cremastogyne Burk by a two-stage culture procedure: initiation on WP medium supplemented with 2-8 μ M benzylammopurine(BAP) for 6 weeks, thereafter 3 weeks of subculture(shoot multiplication) on the same medium with 1 μ M BAP. A 5-9 fold multiplication rate was achieved. Type and concentration of sugar used in the multiplication medium were shown to be critical factors for both multiple shoot induction and bud elongation, the optima being 87.5mM glucose and 87.5mM sucrose respectively. After transfer to half-strength WP media either containing indolebutyric acid (IBA) or lacking plant growth regulator, almost all the shoots rooted. However, high rhizogenesis could be achieved only with shoots cultured in rooting medium containing 87.5mM sucrose or 175mM glucose, and shoots from multiplication media containing 87.5mM sucrose. Survival of the plantlets following transfer to vermiculite was 100%.