[Familial amyloidotic polyneuropathy (FAP) type I and the therapies]

Since autonomic dysfunction in familial amyloidotic polyneuropathy (FAP) Type I is recognized in the early stage of FAP patients and restricts their daily life, we developed various therapies for various autonomic manifestations: Loading glucose was often effective for faintness caused by hypoglycemia and erythropoietin was also good therapy for orthostatic hypotension as well as anemia found in the end stage of FAP patients. Stoma and nasal drop of L-threo-DOPS were useful to control diarrhea and orthostatic hypotension. Duplex ultrasonography of the 4 vessels revealed that reverse flow was always recognized in FAP patients with faintness, which was effectively treated by the administration of L-threo-DOPS. Orthotopic liver transplantation revealed effective therapy for autonomic dysfunction in FAP patients. Precise analysis of protein metabolism in FAP patients revealed that among apolipoproteins, only apolipoprotein AII decreased as the progression of the disease and high density lipoprotein gained the negative charge by agarose electrophoresis study. Concerning low density lipoprotein (LDL) study, only variant transthyretin in the circulation associated with LDL in FAP patients, suggesting that LDL may play an important role in the amyloid formation of FAP.

Association of chronic lymphocytic thyroiditis and thyroid papillary carcinoma. A study of surgical cases among Japanese, and white and African Americans

BACKGROUND

An association between lymphocytic thyroiditis and thyroid papillary carcinoma is still controversial. To determine a definite statistical relation, a histopathologic study was performed on tissues from in three races, because there is a racial and age-related difference in the susceptibility to thyroiditis.

METHODS

The prevalence and severity of thyroiditis combined with adenomatous goiter, follicular adenoma, or papillary carcinoma was defined by examination of surgically resected materials from Japanese (626 patients), and white and African Americans (330 and 90 patients, respectively).

RESULTS

The prevalence of lymphocytic infiltrates, which are indicative of autoimmune thyroiditis, was significantly higher in patients with papillary carcinoma than in patients with adenomatous goiter or follicular adenoma among Japanese females (63.0%) and males (50.0%), white females (76.0%), and African American females (46.2%). Lymphocyte infiltration into the follicular adenoma or papillary carcinoma correlated with the severity of combined thyroiditis.

CONCLUSION

An association between chronic lymphocytic thyroiditis and papillary carcinoma was confirmed in the Japanese, and white and African American populations. The possibility of autoimmune thyroiditis as a predisposing factor for papillary thyroid carcinoma, is suggested.

[Biosynthesis, processing, and lysosome targeting of acid phosphatase]

The biosyntheses, processing, and intracellular transport of lysosomal APase were studied using pulse-chase experiments with primary cultured rat hepatocytes and subcellular fractionation techniques of rat liver after pulse-labeling with [35S] methionine in vivo. Apase was transported as a membrane-bound enzyme from the site of synthesis in the ER through the Golgi complex to lysosomes. Unlike many lysosomal enzymes which are translocated into lysosomes through the mediation of the Man-6-P receptors, transport of APase to lysosomes was independent of the Man-6-P receptor system. The transport of APase to lysosomes is dependent on the GY-motif which is located in its cytoplasmic domain. Kinetic experiments combined with subcellular fractionation of rat liver showed that after reaching the lysosomes, the membrane-bound APase (67 kDa) is subsequently released into the lysosomal matrix in the 64 kDa form, which is further processed via the 55 kDa form to the 48 kDa one, the major form of APase in rat liver lysosomal content. Our data from the in vitro experiments further showed that APase is released from lysosomal membranes into the lysosomal matrix by cathepsin D in the 65 kDa form, with release of a 1 kDa peptide, following which the released enzyme is further processed to the 64 kDa form, probably by lysosomal cysteine protease.

[Analysis of 4 cases of intralobar pulmonary sequestration]

Four cases with pulmonary sequestration treated in Tottori university hospital between January 1993 and December 1994 were reported. Case 1 was a 63-year-old male who had lung tumor without inflammatory findings. Differential diagnosis from lung cancer was needed, and aortography showed a aberrant artery from descending aorta. Pulmonary partial resection and division of aberrant artery were performed. Case 2 was a 71-year-old female who diagnosed pulmonary sequestration in other hospital 10 years ago. Tumor shadow did not progress compared with the old X-ray film. Because tumor size was remarkably diminished by aspiration of cystic tumor, conservative follow up was continued. Both case 3 and 4 were a 20-year-old man and 16-year-old female who had typical findings of pulmonary sequestration with inflammation and easily detection of aberrant artery by CT or aortography. Resection of sequestrated lung and division of aberrant arteries were performed in both cases. Pulmonary sequestration was the disease which should be always kept in our mind in differential diagnosis from various lung disease.

Fracture of the tarsal navicular associated with calcaneonavicular coalition: a case report

Fracture of the navicular occurred in a 23-year-old male with unilateral cartilaginous calcaneonavicular coalition. Inversion sprain of the left foot caused the longitudinal navicular fracture next to the coalition. En bloc resection from the beak of the calcaneus to the fracture line of the navicular including the calcaneonavicular coalition was performed, and a short leg cast was applied for 10 days. Four weeks after surgery, he returned to his preinjury level of activity and job as a long-distance truck driver. Two years and 3 months after surgery, he was totally asymptomatic and had gained a full range of subtalar motion. He had no peroneal spasm or recurrence of the coalition.

[Radiotherapy for intracranial meningioma: special reference to malignant and high risk benign meningioma]

Results of radiotherapy in 21 patients who had been treated for intracranial meningioma from April 1975 to March 1993 at Tokyo Metropolitan Komagome Hospital are presented. All patients were treated with 4 MV X-rays using conventional fractionation. The median tumor dose was 54.4 Gy (range 30 Gy to 70 Gy). Radiotherapy was delivered by conformation technique in 11, parallel opposed field in four and three ports technique in two. Of 21 meningiomas, 13 were histologically malignant and 8 were benign. The median follow-up period was 63 months. Overall survival rate at 5 years was 71% for benign and 63% for malignant meningiomas; the 5-year progression-free survival rates were 25% and 30%, respectively. Eight of 21 patients received 60 Gy or more, and the remaining 13 received less than 60 Gy. The 5-year overall survival rates for these two groups were 43% and 83% (p < 0.05), respectively. Ten of 21 patients were treated with post-operative radiotherapy as initial treatment and eleven of 21 patients were treated with salvage therapy with or without surgical excision for recurrent lesions. The 5-year survival rates and progression-free survival rates of these two groups showed no significant differences. From analysis of the clinical course of the salvage therapy group, radiotherapy may prolong survival time and delay further tumor recurrence. According to the present study, radiotherapy (doses of 55 Gy to 60 Gy) after primary resection and at the time of recurrence are equally effective for prolongation of survival and delay of further tumor recurrence.

IL-4 upregulates Fc epsilon RI alpha-chain messenger RNA in eosinophils

By using the reverse transcription polymerase chain reaction and Southern blot hybridization, we demonstrated that Fc epsilon RI alpha-chain (Fc epsilon RI alpha) messenger RNA was expressed in eosinophils purified from the peripheral blood of patients with allergic rhinitis and that this expression was enhanced by IL-4. However, studies in which flow cytometry or immunostaining was used did not reveal the expression of Fc epsilon RI alpha protein on eosinophils from peripheral blood. Neither IL-4 alone nor the combination of IL-4 and other cytokines could induce detectable Fc epsilon RI alpha protein; nevertheless, they do express Fc epsilon RI alpha mRNA. Double-labeling immunostaining on cryostat sections of nasal mucosa clearly demonstrated that some Fc epsilon RI alpha-positive cells were eosinophil cationic protein-positive, which confirms their eosinophilic nature. Not all the eosinophil cationic protein-positive cells express on Fc epsilon RI alpha signal. Considering that Fc epsilon RI alpha mRNA was detectable in four of five samples of eosinophils from those patients with nasal allergy and that only one of five eosinophil samples from normal subjects expressed Fc epsilon RI alpha mRNA, the level of Fc epsilon RI expression may be correlated with the activation of eosinophils. It seems very likely that some other unidentified factors are required for the process from the expression of Fc epsilon RI alpha mRNA to that of Fc epsilon RI as a protein.

Molecular cloning and analysis of the cDNA for an auxin-regulated calmodulin gene

An auxin-regulated calmodulin cDNA (arCaM) were isolated by differential screening from a mung bean (Vigna radiata) cDNA library. The expression of the arCaM transcript in the etiolated mung bean hypocotyl was examined by RNA gel blot analysis. The arCaM transcript was induced depending on indole-3-acetic acid (IAA) concentrations. An increase in level of the arCaM transcript upon treatment of hypocotyl segments with 10 microM IAA was detected after 1 h and a maximum level was detected at 2 h. Induction of the arCaM transcript occurred upon treatment with 10 microM 2,4-dichlorophenoxyacetic acid (2,4-D) or naphthalene-1-acetic acid (NAA) as well as with IAA, while treatment with 10 microM p-chlorophenoxyisobutyric acid (PCIB) as an anti-auxin, prevented the induction. Ethylene did not have any effect. Other stress conditions, such as exposure to salt stress, heavy metal ions and heat shock, also had no effect on the induction. The levels of the arCaM transcript in leaves of light-grown mung bean plants treated with IAA showed steady but small increases with time.

Human esophageal carcinomas frequently express the tumor-rejection antigens of MAGE genes

The human genes MAGE-1 and -3 encode melanoma peptide antigens that are recognized by autologous cytotoxic T lymphocytes. Tumors expressing MAGE genes are potential targets for cancer immunotherapy, because MAGE genes are expressed only in tumor tissue and not in any normal tissue except testis and placenta. However, little is known about MAGE gene expression in human esophageal carcinoma. The purpose of this study was therefore to analyze MAGE gene status in human esophageal carcinoma. We studied the expression status of these genes in 42 surgical samples and in 12 cell lines of human esophageal carcinoma using the reverse transcription polymerase chain reaction (RT-PCR). Various clinicopathological factors were also analyzed. No MAGE gene expression was seen in any of the 42 normal esophageal tissue specimens. In contrast, tumor tissue expressed MAGE-1, -2, and -3 in 26, 18 and 24 specimens, respectively. Thirty-three of 42 tumors expressed at least one MAGE gene. Significant clinicopathologic differences between the tumors were not observed, regardless of the presence or absence of MAGE gene expression. In cell lines, MAGE-1, -2, and -3 gene expression was recognized in 5, 4 and 4 cell lines, respectively. This study demonstrates that MAGE genes are frequently expressed in clinical samples as well as in cell lines of esophageal carcinoma. The identification of MAGE genes, therefore, may open up a new modality of treatment, namely specific immunotherapy, for patients with esophageal carcinoma.

Marked acceleration of the metastatic phenotype of a rat bladder carcinoma cell line by the expression of human gelatinase A

Numerous studies have reported a correlation between the production of gelatinases A and B by cancer cells and invasive and metastatic potential. It has been suggested that the expression of gelatinase A (72-kDa type IV collagenase) is associated more closely with the metastatic phenotype of malignant cells in vitro and in vivo than that of gelatinase B (92-kDa type IV collagenase). We have established a rat bladder carcinoma cell line, MYU3L, which is tumorigenic and locally invasive but is not metastatic to the distal organs in nude mice. The MYU3L cell line secretes pro-gelatinase B but not any detectable level of pro-gelatinase A. We undertook the present study to determine whether over-expression of gelatinase A can affect the metastatic potential of MYU3L cells. We transfected MYU3L cells with an expression vector containing human pro-gelatinase A cDNA under the transcriptional control of the SR alpha promoter. Two stable transfectants over-expressing gelatinase A activity were isolated. We assessed the biological behavior of the transfectants by an orthotopic site (urinary bladder) inoculation and an i.v. injection in nude mice. Our results demonstrate that the induced expression of human gelatinase A enzyme markedly accelerates the metastatic phenotype of the rat bladder carcinoma cell line MYU3L. Our results suggest that gelatinase A produced by tumor cells plays a major role in the metastatic process.

Studies on antiulcer agents. IV. Antiulcer effects of 2-benzylthio5,6,7,8-tetrahydro-4(3H)-quinazolinones and related compounds

With a view to finding more effective antiulcer agents, a series of 2-benzylthio-5,6,7,8-tetrahydro-4(3H)-quinazolinones and related compounds were synthesized and evaluated in a histamine-stimulated gastric secretion model. The sodium salt of the 2-(dimethylamino)benzylthio derivative (8) showed gastric mucosal protection and gastric antisecretion activities, and was also effective against experimental gastric and duodenal ulcers induced by some ulcerogenic agents. Based on a comparison of the antiulcer properties of 8 with those of the lead compounds (1 and 2) and cimetidine, it appears that, for improvement of antiulcer activity, the reduction of gastric acidity is a more important factor than the reduction of gastric volume output or gastric total acid output.

Choroid plexus papilloma of the III ventricle in an infant

A case of choroid plexus papilloma of the III ventricle associated with hydrocephalus in an 1-month-old boy is reported. The tumor was removed after placement of a ventriculoperitoneal shunt; however, the histologically mainly benign tumor grew very rapidly. The cause of this rapid growth may have been a drop in the intraventricular pressure after the shunting procedure.

Increased plasma thrombin-antithrombin III complex levels in non-insulin dependent diabetic patients with albuminuria are reduced by ethyl icosapentatenoate

Hypercoagulability may increase the risk of cardiovascular disease (CVD) in diabetic patients with albuminuria. Plasma thrombin-anti-thrombin III complex (TAT) levels, representing a functional state of clotting system, were studied in one hundred and fifteen non-insulin-dependent diabetic (NIDDM) patients. The patients were divided into three groups according to the urine albumin index (UAI: mg/g Cr): Group A; UAI < 30, Group B; 30 < UAI < 300, Group C; UAI > 300. The effect of albuminuria on plasma TAT levels was significant (p < 0.02). Ethyl icosapentatenoate (EPA: 1800 mg/day) for 4 weeks significantly (p < 0.0005) decreased plasma TAT levels. These data indicate that the degree of diabetic albuminuria is related to plasma TAT levels in NIDDM patients and that treatment with EPA may reduce TAT levels and possibly therefore the rate of development of CVD in patients with NIDDM.

[Electron microscopic studies of retinal pigment epithelial cells incubated with L-dopa in 10% and 20% oxygen]

In order to make clear how the ultrastructure of the bovine second-passage retinal pigment epithelium (RPE) was affected by exposure to L-dopa and oxygen, we compared the toxic effects of melanotic and amelanotic RPE. The oxygen levels in the incubators and the L-dopa concentrations in the media were adjusted to 10% or 20% oxygen by adding nitrogen gas and 100 microM or 250 microM L-dopa, respectively. After 24 hours, melanotic and amelanotic RPE were fixed and embedded in epon. Ultrathin sections were examined by transmission electron microscopy. Rough endoplasmic reticula were found to be dilated and ribosomes were extinguished in both melanotic and amelanotic RPE. The damage by L-dopa in melanotic RPE was less than that in amelanotic RPE and less in 10% oxygen than in 20% oxygen.

[Effect of inhaled vancomycin hydrochloride on elimination of methicillin-resistant Staphylococcus aureus]

Vancomycin hydrochloride (VCM) is one of the most useful drugs in treating methicillin-resistant Staphylococcus aureus (MRSA) infections. Intravenous administration of the drug is, however, not appropriate in patients with impaired renal or liver function. Thus, we studied the effect of inhaled VCM on MRSA. Fifty-one patients with MRSA in their sputum (35 men and 16 women 21, in the "infected" group and 30 in the "colonized" group, mean age 76.4 years) were studied. MRSA was eliminated in 84.3% of the patients (43 of 51 patients), and the average time required for elimination was 14.7 days. MRSA colonization or infection recurred in 46.5% of the patients (20 of 43 patients), and the duration from elimination until recurrence of MRSA averaged 28 days. Eight patients in whom MRSA was not eliminated by inhaled VCM were not clinically distinguishable from other patients, but their performance status was worse. Two hours after VCM was inhaled, serum VCM concentrations were unmeasurable in 7 patients. The VCM level in sputum peaked at 262.5 micrograms/g just after inhalation, and then gradually decreased. No side effects of this treatment were observed. These results suggest that inhaled VCM can be used to eliminate MRSA.

Histopathology and pathophysiology of secondary hyperparathyroidism due to chronic renal failure

Between 1973 and 1992, 300 patients underwent parathyroidectomy for secondary hyperparathyroidism due to chronic renal failure in our departments. Using parathyroid glands obtained at operation, histopathological studies were performed, and to estimate pathophysiology DNA analysis of parathyroid cell nuclei and calcium-regulated parathyroid hormone (PTH) secretion in vitro were estimated. PTH mRNA expression was evaluated by in situ hybridization. The typical histopathological findings were asymmetric enlargement, nodularities and increased number of oxyphil cells. Secondary hyperplasia was divided into 2 types: diffuse and nodular type hyperplasia. In the histopathological study nodular hyperplasia indicated more aggressive proliferation. In DNA analysis the relative number of scattered cells in the DNA synthesis phase was significantly greater in nodular than in diffuse hyperplasia. The half of the maximal inhibition of PTH secretion for calcium (the set-point) in the cells from nodular hyperplasia was higher than in the cells obtained from diffuse hyperplasia. However, there was no difference in expression of PTH mRNA in nodular and diffuse hyperplasia. These data suggested that nodular hyperplasia was more progressively hyperplastic, had more aggressive proliferative activities and showed more abnormal regulation of PTH secretion. These results imply that to prevent graft-dependent recurrent hyperparathyroidism after parathyroidectomy, the nodular hyperplastic tissue should not be autografted.

Involvement of human interleukin 6 in experimental cachexia induced by a human uterine cervical carcinoma xenograft

A human tumor xenograft model for cancer cachexia was established by growing a uterine cervical carcinoma, Yumoto, in nude mice. The tumor transplanted into the mice induced severe body weight loss (30% of body weight) when the tumor weight was only 1 g. In addition, other indicators for cachexia, such as adipose tissue and muscle wasting and hypoglycemia, were also observed in the tumor-bearing mice, suggesting that this is a proper model for experimental cachexia induced by a human tumor. We then examined the association of this model with various cytokines, such as tumor necrosis factor alpha, interleukin (IL)-1alpha, IL-1beta, IFN-gamma, IL-6, and leukemia inhibitory factor, and identified human IL-6, which was produced by the tumor cells, as a mediator of cachexia. A neutralizing antibody against hIL-6 administered to the mice after the development of cachexia symptoms significantly improved body weight loss, adipose tissue wasting, hypoglycemia, acute phase reaction, and leukocytosis, although it did not suppress the tumor growth. These results demonstrate that the hIL-6 produced by the tumor cells is an essential mediator of the cachexia induction in this model.

Effect of salt concentration on the pKa of acidic residues in lysozyme

We determined the pKa values of acidic residues in hen lysozyme by comparing the pH dependency of stability between wild type and mutant lysozymes in which a negative charge is eliminated. In the comparison of the stability between wild type and a mutant lysozyme, the difference in pH titration curve between them could be expressed as a two-state process involving protonation of a single acidic residue. The results strongly indicated that the Aune and Tanford theory of protein denaturation [Aune, K.C. and Tanford, C. (1969) Biochemistry 8, 4579-4585] is applicable to protein stability in solution. On the other hand, the pKa values of acidic residues in the presence of low (5 mM) or high (400 mM) salt concentration were determined by means of two-dimensional NMR. We found that the pKa values obtained from the pH dependency of stability were close to those from the NMR experiment under the high salt condition. Moreover, by comparing pKa values at high salt and low salt concentrations, we could evaluate the dependency of two electrostatic interactions (salt bridge and charge-helix dipole interaction) on salt concentration.

[Study of anti-tumor effects of hyperthermia combined with hydralazine on experimental tumor]

We analyzed tumor growth delay in experimental tumors after hyperthermia alone, hydralazine (HDZ) injection alone and the combination of these modalities. We also analyzed the energy parameter (ATP/Pi ratio) obtained by 31P-MRS (magnetic resonance spectroscopy). The purpose of this study was to evaluate the usefulness of 31P-MRS as an index of anti-tumor effect. FM3A tumor cells were transplanted subcutaneously in the hind legs of C3H/He mice. We dipped the tumors into a heated circulating water bath. 31P-MRS was performed with a CSI spectrometer. The anti-tumor effect obtained with HDZ alone was insignificant, but combined treatment with hyperthermia and HDZ had a significant synergistic effect. The ATP/Pi ratios for all groups treated separately with HDZ or hyperthermia were not different from the control, but the ATP/Pi ratio decreased after combined use of these agents. There was a significant correlation between the decrease in ATP/Pi ratio and tumor growth delay. We observed a direct relation between the delay in tumor growth and the decline in ATP/Pi ratio after combined treatment with HDZ and hyperthermia. The ATP/Pi ratio 24 hr after treatment may be useful in predicting the efficacy of the combined use of HDZ and hyperthermia.

The functional hepatic volume assessed by 99mTc-GSA hepatic scintigraphy

The accuracy of measurement of the functional hepatic volume by single photon emission computed tomography (SPECT) with 99mTc-galactosyl serum albumin (99mTc-GAS) was evaluated. 99mTc-GSA planar scintigraphic images were obtained dynamically and the hepatic SPECT imaging was then performed in 25 patients with hepatobiliary tumors. The patients were divided into 4 groups with normal hepatic function, and mild, moderate and severe hepatic dysfunction. The functional hepatic volume determined by SPECT was compared with the morphological hepatic volume determined by compute tomography. The ratio of the hepatic volumes obtained by the two methods was calculated. The mean hepatic volume ratio was 96.6 +/- 2.3% in the normal hepatic function group and 95.9 +/- 2.2% in the mild dysfunction group (n.s.). In both the moderate and severe hepatic dysfunction groups, the hepatic volume ratio was smaller than that in the normal group (87.9 +/- 5.2%, p < 0.0001, and 71.9 +/- 7.6%, p < 0.0001, respectively). There was a linear correlation between the hepatic volume ration and various indices of reserve hepatic function, such as LHL15 (r = 0.83, p < 0.0001), HH15(r = 0.74, p < 0.0001), and ICG15 (r = 0.75, p < 0.0005). These results indicate that the hepatic volume ratio is proportional to the severity of hepatic dysfunction, and suggest that the functional hepatic volume measured with 99mTc-GSA faithfully reflects the functioning hepatocyte mass. 99mTc-GSA scintigraphy and hepatic SPECT therefore provide information regarding global and regional reserve hepatic function.

High affinity IgE receptor-mediated prostaglandin E2 production by monocytes in atopic dermatitis

High affinity IgE receptor (Fc epsilon R I) expression on monocytes and its upregulation on monocytes from patients with atopic dermatitis (AD) have been recently reported. In this study, we investigated whether prostaglandin E2 (PGE2) release from AD monocytes was Fc epsilon R I-dependent or not. The monocytes were stimulated with anti-Fc epsilon R I monoclonal antibody (mAb) and anti-Fc epsilon R II mAb. Cross-linking of Fc epsilon R I, but not that of Fc epsilon R II induced PGE2 release from monocytes. In order to confirm that the PGE2 release is IgE-dependent, stimulation with IgE+anti-IgE, IgG+anti-IgG and immune complexes made by incubation with AD patients' serum and recombinant Der fII (rDer fII-IC) were carried out in the culture. Significant PGE2 release by all the stimulants was observed, as compared with spontaneous release. PGE2 release by immune complex made by incubation with IgE-absorbed AD serum and rDer fII was much lower than that by rDer fII-IC. In monocytes from nonatopic donors, significant PGE2 release was observed when stimulated with IgE+anti-IgE, IgG+anti-IgG, rDer fII-IC, but not with anti-FC epsilon R I mAb and anti-Fc epsilon R II mAb. However, the release were significantly lower than respective PGE2 releases from AD monocytes. Taken together, cross-linking of Fc epsilon R I and IgE induced a PGE2 release from monocytes. This is a first report demonstrating an Fc epsilon R I-dependent mediator release from monocytes of AD patients.

Stereospecific taurine conjugation of the trans-OH metabolite (active metabolite) of CS-670, a new 2-arylpropionic acid nonsteroidal anti-inflammatory drug, in dogs

CS-670, (+/-)-2-[4-(2-oxocyclohexylidenemethyl)phenyl]propionic acid, is a novel derivative of 2-arylpropionic acid non-steroidal anti-inflammatory drugs (profen NSAIDs). The major urinary metabolite of this drug from dogs was isolated and its chemical structure was determined by MS and NMR spectroscopy. The metabolite was identified as a taurine conjugate of the trans-OH form (trans-OH-taurine) which was first generated by stereoselective reduction of the double bond and the carbonyl function of the CS-670 molecule. The taurine conjugate was excreted in urine as the main metabolite, regardless of the optical configuration of CS-670 administered [2R)-enantiomer: 47.2% of the dose, (2S)-enantiomer: 70.9% of the dose]. The trans-OH-taurine was hydrolyzed by refluxing it in 6 N HCl without racemization. The released trans-OH was derivatized to diastereoamides with (+)-(R)-1-(1-naphthyl)ethylamine to examine the stereochemical properties of the 2-arylpropionic acid side chain. It was found that the configuration of the 2-carbon of the trans-OH-taurine was almost entirely (S). As the CoA thioesters are obligate intermediates for amino acid conjugation, the results suggest that the (2S)-enantiomer of the trans-OH metabolite serves as a substrate for canine acyl CoA ligase (EC 6.2.1.3) as well as the (2R)-enantiomer, but only the CoA thioester with a (2S)-configuration is a substrate for taurine N-acyl transferase. It is interesting to note that these results are not consistent with the chiral inversion mechanism by which the (2R)-enantiomers of profen NSAIDs are stereospecifically converted to CoA thioester intermediates.