New factor characterizing the in-mouth release of odorants (volatile thiols): compositional changes in odorants exhaled from the human nose during drinking

The aim of this research was to investigate the relationship between the odorants in the model drink and the odorants reaching the olfactory epithelium using the Retronasal Flavor Impression Screening System (R-FISS). By application of the R-FISS to the odorants in the model drink, it was found that a methylthio ether [1-methoxy-3-methyl-3-(methylthio)butane] was detected with the original volatile thiol (4-methoxy-2-methyl-2-mercaptobutane) in the air exhaled through the nostrils via the nasal cavity after the model drink (including the original thiol) had been swallowed. In addition, this phenomenon was also observed in other volatile thiols (furfuryl mercaptan, ethyl 2-mercaptopropionate, 2-methyl-1-mercaptobutane, and 4-mercapto-4-methyl-2-pentanone). These compositional changes in thiols that were observed in the air exhaled through the nostrils could be affected by the chemical structure of each tested thiol and individual differences. These results pointed to a possibility that the odorants reaching the olfactory receptor via the throat during consumption of foods could not always retain their original chemical structures and compositions in foodstuffs. Therefore, the characteristic odor of volatile thiols might be perceived due to the stimuli of multiple compounds. To understand in detail flavor perception during the consumption of foods, not only the compositions or amounts of odorants in foodstuffs but also the compositional changes in odorants induced by biological reactions (reduction or methylation) need to be taken into consideration.

Character impact odorants of high-heat skim milk powder isolated by simultaneous distillation-extraction

To identify the character impact odorant of high-heat skim milk powder (HHSMP), a comparative study using ultrahigh-temperature (UHT) milk was performed. Aroma concentrate was prepared by column adsorption combined with simultaneous distillation-extraction. Aroma extract dilution analysis (AEDA) revealed 58 aroma peaks with flavor dilution (FD) factors ranging from 10 to 3000; from these, 41 compounds were identified and 7 compounds were tentatively identified (FD factor > or = 300). Among these HHSMP and UHT milk components, methyl 2-methyl-3-furyl disulfide and bis(2-methyl-3-furyl) disulfide, which appeared to be generated during the processing of each product, were identified. When the results of the AEDA of both samples were compared, it was considered that the characteristic aroma of HHSMP was not explained by a single compound but instead formed from a mixture of several types of compounds contained in common with the UHT milk. The contribution of these compounds to the aroma of HHSMP was confirmed by an aroma simulation experiment.

Characterization of epoxydecenal isomers as potent odorants in black tea (Dimbula) infusion

In a black tea (Dimbula) infusion, the potent "sweet and/or juicy" odorants were identified as the cis- and trans-4,5-epoxy-(E)-2-decenals by comparison of their gas chromatography retention indices, mass spectra, and odor quality to those of the actual synthetic compounds. Of the two odorants, cis-4,5-epoxy-(E)-2-decenal has been identified for the first time in the black tea. On the basis of the aroma extract dilution analysis on the flavor distillate obtained using the solvent-assisted flavor evaporation technique from the black tea infusion, these isomers showed higher flavor dilution (FD) factors. The FD factors and concentrations of these odorants in the black tea infusion were observed to be much higher than those from Japanese green tea. In addition, the model studies showed that these odorants were generated from linoleic acid and its hydroperoxides by heating, but the generated amounts of these odorants from linoleic acid were much less than those of its hydroperoxides. It can be assumed from these results that the withering and fermentation, which are characteristic processes during the manufacturing of the black tea, which includes the enzymatic reaction such as lipoxygenase, is one of the most important factors for the formation of the epoxydecenal isomers.

Molecular and sensory studies on the umami taste of Japanese green tea

Aimed at defining the key drivers for the quality-determining umami taste of a high-grade powdered green tea, called mat-cha, a bioactivity-guided fractionation using solvent extraction, solvent precipitation, preparative chromatographic separations, and human psychophysical experiments was applied on freshly prepared mat-cha. Liquid chromatography-tandem mass spectrometry and one-/two-dimensional nuclear magnetic resonance studies on isolated fractions led to the identification of l-theanine, succinic acid, 3,4,5-trihydroxybenzoic acid (gallic acid), and (1R,2R,3R,5S)-5-carboxy-2,3,5-trihydroxycyclohexyl-3,4,5-trihydroxybenzoate (theogallin) as umami-enhancing compounds in the green tea beverage, and it can be shown by sensory studies that these compounds are able to raise the umami intensity of sodium l-glutamate proportionally.

Influence of manufacturing conditions and crop season on the formation of 4-mercapto-4-methyl-2-pentanone in Japanese green tea (sen-cha)

4-Mercapto-4-methyl-2-pentanone is one of the most strongly contributing odorants in the volatile fraction of a Japanese green tea (sen-cha) infusion, and on the basis of the results of an aroma extract dilution analysis, the contribution of this compound to the flavor of the sen-cha infusion varied according to the degree of heating of the tea leaves during the roasting process. The concentration of this odorant in the sen-cha infusion, as with other roasty odorants, increased with the increasing roasting temperature. However, the slope of the increase curve differed with the odor compound, and even if roasting was done at a low temperature, at which the other roasty odorants hardly increased, 4-mercapto-4-methyl-2-pentanone still increased and reached a maximum at 112 degrees C. On the other hand, the amount of 4-mercapto-4-methyl-2-pentanone in sen-cha was a maximum in the first crop, then decreasing in the order of the second and third crops. These results suggested that the amount of 4-mercapto-4-methyl-2-pentanone was closely involved with the quality of sen-cha and that the concentration was dependent on the roasting conditions for the green tea leaves, which might be accompanied by an enzymatic reaction.

Effect of pH on the thermal stability of potent roasty odorants, 3-mercapto-3-methylbutyl esters, in coffee drink

The effect of pH on the thermal stability of potent roasty odorants, 3-mercapto-3-methylbutyl esters, in coffee drinks was investigated. The concentration of 3-mercapto-3-methylbutyl formate in the coffee drink was drastically decreased during the heat processing. However, the residual ratio of this compound in the coffee drink adjusted to pH 5.0 was higher than that of pH 6.5. On the other hand, the residual ratios of 3-mercapto-3-methylbutyl acetate showed high values in the coffee drinks adjusted to both pHs. In the pH range of 3-7, the residual ratios of 3-mercapto-3-methylbutyl formate in aqueous model solutions varied depending on the pH value. It had a thermal stability maximum at pH 4.0, while 3-mercapto-3-methylbutyl acetate showed stability during heat processing over all the pH values tested. In addition, the residual ratios of the formate and acetate esters, which were composed of various alcohol derivatives, showed the same tendency as that of the 3-mercapto-3-methylbutyl esters. These results suggested that the low thermal stability and pH dependence of 3-mercapto-3-methylbutyl formate are based on the structure of the formate ester.

Identification of odor-active 3-mercapto-3-methylbutyl acetate in volatile fraction of roasted coffee brew isolated by steam distillation under reduced pressure

In a roasted Arabica coffee brew, the potent roasty odor quality compound was identified as 3-mercapto-3-methylbutyl acetate by comparison of its Kovats gas chromatography retention index, mass spectrum, and odor quality to those of the synthetic authentic compound. 3-Mercapto-3-methylbutyl acetate has been identified for the first time in the coffee, and according to the results of the aroma extract dilution analysis, the contribution of this compound to the flavor of the roasted coffee brew varied depending on the degree of the coffee bean roasting. The concentration of this compound in the coffee brews as with 3-mercapto-3-methylbutyl formate increased with an increase in the degree of roasting. However, the slope of the amount of both esters was different, and 3-mercapto-3-methylbutyl acetate hardly increased with a low degree of roasting at more than a 21 luminosity (L)-value, but it rapidly increased when the roasting degree of the coffee beans reached the L-value of 18. These results suggested that the contribution of 3-mercapto-3-methylbutyl acetate to the overall flavor is peculiar to the flavor of the highly roasted coffee.

Investigation of the change in the flavor of a coffee drink during heat processing

Heat processing is responsible for the change in the flavor of a coffee drink. In this study, the application of gas chromatography-olfactometry of headspace samples (GCO-H) using the vapor fraction before and after heat processing of the coffee samples resulted in the detection of 12 odor-active peaks for which the flavor dilution (FD) factors changed. Eight potent odorants were identified from these peaks by gas chromatography-mass spectrometry (GC-MS). Among these components, methanethiol (putrid), acetic acid (sour), 3-methylbutanoic acid (sour), 2-furfuryl methyl disulfide (meaty), and 4-hydroxy-2,5-dimethyl-3(2H)-furanone (caramel-like) increased after heating of the coffee sample, whereas 2-furfurylthiol (roasty), methional (potato-like), and 3-mercapto-3-methylbutyl formate (roasty) decreased compared with the coffee sample before heat treatment. In addition, extensive studies have been carried out on the pH effects on the change in the concentration of 2-furfurylthiol during heat processing and in the pH range of 5-7; it was found that the concentration of this compound in the model solutions had significantly changed.

Identification of potent odorants in different green tea varieties using flavor dilution technique

Two kinds of pan-fired green teas (Japanese Kamairi-cha and Chinese Longing tea) were compared with the common Japanese green tea (Sen-cha). Application of the aroma extract dilution analysis (AEDA) using the volatile fraction of the Sen-cha, Kamairi-cha and Longing tea infusions revealed 32, 51, and 52 odor-active peaks with flavor dilution factors between 16 and 1024, respectively. (Z)-1,5-Octadien-3-one (metallic, geranium-like), 4-mercapto-4-methyl-2-pentanone (meaty, black currant-like), methional (potato-like), (E,Z)-2,6-nonadienal (cucumber-like), and 3-methylnonane-2,4-dione (green, fruity, hay-like) showed high flavor dilution factors in all varieties. In addition, 2-acetyl-1-pyrroline (popcorn-like), 2-ethyl-3,5-dimethylpyrazine (nutty), 2,3-diethyl-5-methylpyrazine (nutty), and 2-acetyl-2-thiazoline (popcorn-like) belonged to the most potent odorants only in the pan-fired green teas. Among these odorants, 2-acetyl-1-pyrroline and 2-acetyl-2-thiazoline were identified for the first time among the tea volatiles.

Identification of potent odorants in different green tea varieties using flavor dilution technique

Two kinds of pan-fired green teas (Japanese Kamairi-cha and Chinese Longing tea) were compared with the common Japanese green tea (Sen-cha). Application of the aroma extract dilution analysis (AEDA) using the volatile fraction of the Sen-cha, Kamairi-cha and Longing tea infusions revealed 32, 51, and 52 odor-active peaks with flavor dilution factors between 16 and 1024, respectively. (Z)-1,5-Octadien-3-one (metallic, geranium-like), 4-mercapto-4-methyl-2-pentanone (meaty, black currant-like), methional (potato-like), (E,Z)-2,6-nonadienal (cucumber-like), and 3-methylnonane-2,4-dione (green, fruity, hay-like) showed high flavor dilution factors in all varieties. In addition, 2-acetyl-1-pyrroline (popcorn-like), 2-ethyl-3,5-dimethylpyrazine (nutty), 2,3-diethyl-5-methylpyrazine (nutty), and 2-acetyl-2-thiazoline (popcorn-like) belonged to the most potent odorants only in the pan-fired green teas. Among these odorants, 2-acetyl-1-pyrroline and 2-acetyl-2-thiazoline were identified for the first time among the tea volatiles.

DOSY study on dynamic catenation: self-assembly of a [3]catenane as a meta-stable compound from twelve simple components

Synthesis of [2]catenane 6 has been successfully achieved by the combination of Pd complex 1 and pyridines 2 and 3 at a molar ratio of 2:1:1 in D20. A mixture of square molecule 4 (prepared from 1 and 2) and macrocycle 5 (obtained from 1 and 3), in which the final ratio of 1, 2, and 3 was kept 2:1:1 reorganizes in D2O/CD3OD (1:1) to form 6 within one day. However, the same mixture in D2O shows the formation of novel [3]catenane 7 along with the [2]catenane. In order to make 7, the theoretical ratio of components 1, 2, and 3 should be 3:1:2. Thus, deliberately maintaining such ratio of the above-mentioned molecules, a higher proportion of the [3]catenane is observed in D2O as found from 1H NMR spectra of the system. Reorganization of the twelve components to form [3]catenane is supported by studies with the DOSY method. This method is a first attempt to separate, from a mixture, either catenanes or any other supramolecular self-assembly structures. CSI-MS studies further support the assigned catenane super structures 6 and 7. All the results indicate that the [2]catenane is thermodynamically the most stable structure, while the [3]catenane is a meta-stable self-assembly.

Change in the flavor of black tea drink during heat processing

Heat processing during canning is responsible for the change in flavor of black tea infusion. The quantitative change in the volatile components of the black tea infusion during heat processing is not sufficient for explaining the sensory evaluation. In this study, application of aroma extract dilution analysis using the volatile fraction before and after black tea (Darjeeling) samples were heat processed resulted in the detection of 10 odor-active peaks for which flavor dilution (FD) factors changed. Seven potent odorants were identified from these peaks by gas chromatography-mass spectrometry. Among these components, 3-methylbutanal (stimulus), methional (potato-like), beta-damascenone (sweet), dimethyl trisulfide (putrid), and 2-methoxy-4-vinylphenol (clove-like) showed the highest FD factors after heat processing of the black tea sample. Therefore, these odorants were the most important components involved in changing the black tea odor during heat processing. In addition, the precursor of beta-damascenone in black tea infusion was investigated, and 3-hydroxy-7,8-didehydro-beta-ionol was determined to be one of the beta-damascenone-generating compounds for the first time.

Experimental study on lipid and bilirubin metabolism after biliary drainage for obstructive jaundice

BACKGROUND

The present experimental study was carried out to determine variations in bilirubin and lipid metabolism in obstructive jaundice after external biliary drainage alone and in combination with intraintestinal administration of the drained bile.

MATERIALS AND METHODS

Variations in lipid and bilirubin metabolism were studied in adult mongrel dogs with obstructive jaundice treated by external biliary drainage (EBD) and EBD plus intraintestinal administration of autologous bile (IBD).

RESULTS

There was no difference between these two groups in regard to the volume of excreted bile after drainage. The biliary concentration and total daily excretion of bilirubin were higher in the IBD group (P < 0.0001), but there was no intergroup difference in the rate of decrease of serum bilirubin. In regard to lipid metabolism, the levels of total cholesterol, triglyceride, and low-density lipoprotein were decreased after biliary drainage; improvement in lipid metabolism was more rapid in the EBD group. Although the triglyceride level was lower after drainage, the activity of HMG-CoA reductase, the level of high-density lipoprotein 3-C, and the carrier protein apolipoprotein A-I were increased after drainage, with more rapid improvement in the EBD group.

CONCLUSIONS

To improve lipid metabolism in obstructive jaundice, external biliary drainage is superior in the early stages of treatment, while replacement by EBD plus intraintestinal administration of autologous bile may be advantageous in cases of prolonged use.

Beta,gamma-methylene ATP-induced cAMP formation in C6Bu-1 cells: involvement of local metabolism and subsequent stimulation of adenosine A2B receptor

The mechanism underlying beta,gamma-methylene ATP (beta,gamma-MeATP)-induced cAMP elevation was investigated in rat glioma C6Bu-1 cells. Beta,gamma-MeATP increased forskolin-stimulated cAMP formation in a manner sensitive to both the P1 antagonist xanthine amine congener (XAC) and the P2 antagonist pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS). Adenosine deaminase (ADA; 1 U/mL), which abolished the adenosine-induced response, did not eliminate the beta,gamma-MeATP-induced response. However, combination of ADA with alpha,beta-methylene ADP (alpha,beta-MeADP), an ecto-5'-nucleotidase inhibitor, blocked the beta,gamma-MeATP-induced response. AMP, the substrate for ecto-5'-nucleotidase, also induced cAMP formation in a manner sensitive to XAC and alpha,beta-MeADP inhibition. However, the AMP-induced response was not blocked by PPADS. HPLC analyses revealed that adenosine was generated from beta,gamma-MeATP and AMP. In addition, alpha,beta-MeADP inhibited the conversion of beta,gamma-MeATP and AMP to adenosine, whereas PPADS blocked adenosine formation from beta,gamma-MeATP but not from AMP. [3H]Adenosine generated from [3H]AMP was preserved on the cell surface environment even in the presence of ADA. The mRNAs for ecto-phosphodiesterase/pyrophosphatase 1 (EC 3.1.4.1), ecto-5'-nucleotidase (EC 3.1.3.5) and adenosine A2B receptor were detected by RT-PCR. These results suggest that C6Bu-1 cells possess ecto-enzymes converting beta,gamma-MeATP to adenosine, and the locally accumulated adenosine in this mechanism efficiently stimulates A2B receptors in a manner resistant to exogenous ADA.

Identification of potent odorants in Japanese green tea (Sen-cha)

Application of aroma extract dilution analysis using the volatile fraction of a Japanese green tea (Sen-cha) sample resulted in the detection of 36 odor-active peaks with flavor dilution (FD) factors between 10 and 5000. Thirty-six potent odorants were identified from 36 odor-active peaks by gas chromatography/mass spectrometry (GC/MS) and/or the multidimensional GC/MS (MDGC/MS) system. Among these components, 4-methoxy-2-methyl-2-butanethiol (meaty), (Z)-1, 5-octadien-3-one (metallic), 4-mercapto-4-methyl-2-pentanone (meaty), (E,E)-2,4-decadienal (fatty), beta-damascone (honey-like), beta-damascenone (honey-like), (Z)-methyl jasmonate (floral), and indole (animal-like) showed the highest FD factors. Therefore, these odorants were the most important components of the Japanese green tea odor. In addition, 4-methoxy-2-methyl-2-butanethiol, 4-mercapto-4-methyl-2-pentanone, methional, 2-ethyl-3, 5-dimethylpyrazine, (Z)-4-decenal, beta-damascone, maltol, 5-octanolide, 2-methoxy-4-vinylphenol, and 2-aminoacetophenone were newly identified compounds in the green tea.

Clinicopathological features of Churg-Strauss syndrome-associated neuropathy

We assessed the clinicopathological features of 28 patients with peripheral neuropathy associated with Churg-Strauss syndrome. Initial symptoms attributable to neuropathy were acute painful dysaesthesiae and oedema in the dysaesthetic portion of the distal limbs. Sensory and motor involvement mostly showed a pattern of mononeuritis multiplex in the initial phase, progressing into asymmetrical polyneuropathy, restricted to the limbs. Parallel loss of myelinated and unmyelinated fibres due to axonal degeneration was evident as decreased or absent amplitudes of sensory nerve action potentials and compound muscle action potentials, indicating acute massive axonal loss. Epineurial necrotizing vasculitis was seen in 54% of cases; infiltrates consisted mainly of CD8-positive suppressor/cytotoxic and CD4-positive helper T lymphocytes. Eosinophils were present in infiltrates, but in smaller numbers than lymphocytes. CD20-positive B lymphocytes were seen only occasionally. Deposits of IgG, C3d, IgE and major basic protein were scarce. The mean follow-up period was 4.2 years, with a range of 8 months to 10 years. Fatal outcome was seen only in a single patient, indicating a good survival rate. The patients who responded well to the initial corticosteroid therapy within 4 weeks regained self-controlled functional status in longterm follow-up (modified Rankin score was < or = 2), while those not responding well to the initial corticosteroid therapy led a dependent existence (P < 0.01). In addition the patients with poor functional outcomes had significantly more systemic organ damage caused by vasculitis (P < 0.05). Necrotizing vasculitis mediated by cytotoxic T cells, leading to ischaemic changes, appears to be a major cause of Churg-Strauss syndrome-associated neuropathy. The initial clinical course and the extent of systemic vasculitic lesions may influence the long-term functional prognosis.

[Serial MRI findings in patients with CNS cryptococcosis]

We reported the serial magnetic resonance imaging (MRI) findings of two patients with central nervous system (CNS) cryptococcal infection without AIDS. The diagnosis of CNS cryptococcosis was made by visualizing the fungi in the CSF with the India ink test, detecting cryptococcal antigens, and culturing the fungus. Both patients had dilated perivascular Virchow-Robin (V-R) spaces, which were defined as small rounded lesions greater less than 3mm diameter that were hyperintense on T2-weighted images. They were present in the basal ganglia, brainstem and cerebral white matter. Case 1 had bilateral parietal arachnoid cyst which was thought to represent a focal collection of organisms and mucoid material within subarachnoid space. Abnormal optochiasmatic arachnoid enhancement detected in case 2, who had complete loss of vision. With disease progression perivascular V-R increased in size, resulting in the developing cryptococomas which were defined as rounded lesions greater than 3mm diameter, and were hyperintense on T2-weighted images in the basal ganglia, cerebellum and cerebral white matter. In follow-up MRI of those patients, radiological progression was seen despite appropriate treatment and falling CSF cryptococcal antigens. In conclusion, this spectrum of MRI appearances in CNS cryptococcosis reflects the pathological mechanism of invasion by the fungus, and may be relatively specific for cryptococcosis.

[Double filtration plasmapheresis (DFPP) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)]

We studied the therapeutic characteristics of double filtration plasmapheresis (DFPP) in 14 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The patients were classified into 2 subgroups of the responders (7 patients) and the non-responders (7 patients) to DFPP. The responders to DFPP were designated as those showing the improvement 2 or more grades in measures the activity of daily living by the modified Rankin scale (MRS). All these patients underwent neurological assessment, CSF study, electrophysiological studies at the beginning and end of treatment. Sural nerve biopsy study was performed in 10 cases. Neurological function was assessed serially using a quantitative neurological disability score (NDS). At the beginning of treatment, there were no significant differences in various measurements between the responders and the non-responders except for the frequency of demyelination. In responders, significant improvement was found in mean changes in MRS, NDS, motor nerve conduction velocity, compound muscle action potential, distal motor latency, while in non-responders, all measures remained unchanged or worsened. Muscle wasting was seen in 3/7 responders and 4/7 non-responders, and denervation potentials in needle EMG were seen in 1/7 responders and 3/7 non-responders. Four patients of the responders were classified as chronic relapsing course, and 6 patients of the non-responders as chronic progressive course. We conclude that DFPP was useful for the subgroups of CIDP patients, but the underlying immuno-pathological background that determine the efficacy of plasmapheresis should be elucidated.

Clinicopathological features of chronic inflammatory demyelinating polyradiculoneuropathy in childhood

The clinical, electrophysiological, and pathological findings, and the therapeutic characteristics in ten children with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), whose onset age was less than 16 years, were evaluated. The clinical progression pattern of the initial phase divided the patients into two groups. One group (six patients) showed a subacute progression for up to 2 months after onset and a subsided progression over 3 months. Three patients in this group had a preceding febrile episode. The other group (four patients) showed a chronic insidious progression for more than 3 months. The former group of patients revealed a favourable response to corticosteroid therapy as compared with the latter group. However, other clinical and laboratory features at the peak impairment were not distinguishable between these two groups. Motor dominant neuropathy was common to all patients, and only three cases showed sensory disturbance on the distal limbs. No cases revealed cranial nerve involvement. Motor and sensory nerve conduction and sural nerve biopsy studies revealed the demyelinating nature of the neuropathy. These clinicopathological features suggest that the subacute progression form frequently associated with prodromal episode and rather favourable corticosteroid response is characteristic in childhood CIDP, while the chronic insidious progression form is indistinguishable from the common adult CIDP.

Impairment of calcitonin gene-related peptide-induced potentiation of cholinergic sweat secretion in patients with multiple system atrophy

Loss of sweating is a characteristic feature of multiple system atrophy (MSA) with autonomic failure, and widespread anhidrosis may lead to hyperthermia and collapse in a hot environment. Calcitonin gene-related peptide (CGRP) is present in the periglandular nerves around sweat glands and is a strong stimulant of methacholine (MCH)-mediated cholinergic sweating. The present study evaluated CGRP-related regulation of cholinergic sweating in patients with MSA. CGRP-induced potentiation of MCH-mediated cholinergic sweating was significantly reduced in MSA patients as compared with normal age-matched controls. These results suggest that regulation of sweating is extensively affected in MSA as a consequence of peptidergic dysfunction.

Possible mechanism of anhidrosis in a symptomatic female carrier of Fabry's disease: an assessment by skin sympathetic nerve activity and sympathetic skin response

Fabry's disease, X-linked alpha-galactosidase deficiency, features a variety of autonomic abnormalities including anhidrosis. In this study, we measured the skin sympathetic nerve activity (SSNA), skin potential and sweat rate in a symptomatic female carrier to investigate the underlying pathophysiology of anhidrosis. The basal activity and responsiveness of SSNA were both fairly well preserved, although slightly reduced compared with the control levels. However, sweating was completely absent, despite the normal skin potential change in response to SSNA bursts. These results suggest that anhidrosis in Fabry's disease is a result of sweat gland dysfunction as well as abnormal SSNA.