Health and job-related factors associated with work ability in older working populations of Korea.

BACKGROUND: Knowledge about determinants of workability is crucial for designing interventions to increase the participation of older employees in the workforce and maintain or increase their productivity levels at work. AIMS: This study explored the impact of health conditions and job characteristics on poor work ability. METHODS: This study used data from the Korean Longitudinal Study of Aging (KLoSA) from 2014 to 2020, which is a nationally representative population-based panel study of Korean citizens aged ≥45 years. The KLoSA survey assessed subjective work ability using work ability score. The participants were asked if they had been diagnosed with any underlying diseases by a physician. The job characteristics were assessed in terms of working conditions and satisfaction. Generalized estimating equations were used to calculate the odds ratios (ORs) and 95% confidence intervals for workers' health-related variables and job characteristics associated with poor work ability. RESULTS: The results showed that workers' health-related factors were associated with poor work ability; poor vision (OR = 1.52) and bad hearing ability (OR = 2.37); low gripping strength (OR = 2.29); poor self-rated health (OR = 3.77) and various diseases such as hypertension, diabetes, cancer, chronic lung disease, liver disease, heart disease, cerebrovascular disease, mental illness, arthritis, prostate disease, gastrointestinal disease and disc disease. Additionally, high physical work demands (OR = 1.51) and low job satisfaction (OR = 4.23) were highly correlated with poor work ability. CONCLUSIONS: The findings addressing poor work abilities caused by individuals' health- and job-related factors can help prioritize worker health management and the development of more effective human capital investment strategies at the workplace.

[Clinical phenotype and genotype of Gaucher disease in 14 children].

Objective: To analyze the clinical and genetical characteristics of children with Gaucher disease and to explore the relationship between genotype and phenotype. Methods: In this retrospective study, the clinical data of 14 children with Gaucher disease diagnosed in Children's Hospital of Nanjing Medical University from August 2016 to October 2021 were analyzed. Their general conditions, clinical manifestations, laboratory tests and gene variations were collected, followed by the analysis of the clinical phenotypes and genotypes. Results: Among 14 children diagnosed with Gaucher disease, 9 were males and 5 were females, with the age of diagnosis ranging from 0.7 to 15.8 years. There were 10 patients with type 1 Gaucher disease, 2 patients with type 2, and 2 patients with type 3. The most common clinical manifestations were splenomegaly, thrombocytopenia (14 cases), hepatomegaly (8 cases) and anemia (8 cases). There were 6 patients with growth retardation, and 5 patients lag in height compared with their peers. Bone abnormalities were revealed by magnetic resonance imaging in 7 type 1 Gaucher disease patients, but only 1 patient experienced bone pain. Patients with type 2 and type 3 Gaucher disease also presented with convulsions, nystagmus and hearing loss. Gaucher cells were found in bone marrow smears in 12 patients. The glucocerebrosidase gene variations identified in 13 patients were heterozygous and in 1 type 1 patient was homozygous of L483P. L483P variation accounted for 33%(10/30) of the variation alleles, followed by V414L, D448H and R159W. The variation alleles were L483P and L422R, F252I and L483P in 2 children with severe neurological manifestations of Gaucher disease. A novel variation c.22A>G was detected. Conclusions: Splenomegaly and thrombocytopenia are the main clinical presentations of Gaucher disease in children and bone lesions revealed by radiologic imaging appear prior to the occurrence of bone diseases, type 2 and type 3 Gaucher disease also present growth retardation and neurological manifestation. The most frequent variant allele is L483P, which are detected in all 3 subtypes of Gaucher disease. The L422R, F252I gene variants correlated with the neuronopathic phenotype.

Individual modeling of oxygen capture by the human lungs.

It has been proposed that oxygen capture by the human lungs depends on four determinants: ventilation, cardiac output, oxygen partial pressure in the inspired air and the venous blood. Indeed, the theoretical-numerical model proposed recently by Kang et al. was able to interpret the known empirical relation between the average of the determinants and the average oxygen capture called VO2. This method is tested here at the individual level in a group of 31 subjects submitted to standard pulmonary function testing and cardiopulmonary exercise testing. For this, an inverse method is used in which individual cardiac output is predicted from the clinical test data. Comparison to the cardiac output deduced from Fick principle confirms that the dynamic model is a "microscopic" justification of the "macroscopic" Fick principle. It shows that in addition to the four determinants, two secondary determinants, namely hemoglobin concentration and Bohr effect, expressed here through P50, play significant roles.

Diffusion Reaction of Carbon Monoxide in the Human Lung.

The capture of CO, a standard lung function test, results from diffusion-reaction processes of CO with hemoglobin inside red blood cells (RBCs). In its current understanding, suggested by Roughton and Forster in 1957, the capture is represented by two independent resistances in series, one for diffusion from the gas to the RBC periphery, the second for internal diffusion reaction. Numerical studies in 3D model structures described here contradict the independence hypothesis. This results from two different theoretical reasons: (i) The RBC peripheries are not equi-concentrations; (ii) diffusion times in series are not additive.

The Roughton-Forster equation for DLCO and DLNO re-examined.

Roughton and Forster (RF) proposed to split the lung diffusing capacity into two contributions describing first, diffusion to red blood cells (RBC), and second, capture by diffusion from the RBC surface and reaction with haemoglobin. Solving the diffusion-reaction equations for simplified capillary-RBC structures, we investigate the RF interpretation. This reveals first that the conventional extrapolation to zero pressure of 1/DLCO on PO2 is not a correct measure of the diffusive component. Consequently the capillary volumes deduced from this extrapolation are erroneous. Secondly, capture mechanisms are different for CO and NO: while DLCO characterizes "volume absorption" in the RBC and is correlated with hematocrit, DLNO quantifies "surface absorption" and provide information about the morphology of the space between the alveolar surface and the RBC surfaces. In conclusion, the RF approach may lead to erroneous physiological interpretations of DLCO; nevertheless, the measurement of DLCO and DLNO bring different types of information that give the potential for a better understanding of respiratory diseases.

Determination of HPGe peak efficiency for voluminous gamma-ray sources by using an effective solid angle method.

A code called EXVol has been developed to obtain the absolute peak efficiency for an extended or voluminous γ-ray source. The method is based on the concept of effective solid angles. Several efficiency curves that have been determined semi-empirically for voluminous sources are compared with the experimental values based on certified reference volume sources. To study the geometric and matrix effects, standard γ-ray sources of several media, volumes and shapes were measured using HPGe detectors with three different efficiencies. For the n-type detector of 32% relative efficiency, the relative deviations are less than ±10%; this performance is similar to that of existing programs for similar purposes. The EXVol code is able to calculate the detection efficiency within approximately five minutes or less. Systematic errors based on EXVol input parameters, which are mainly due to the inherent uncertainty in the detector's characteristic dimensions provided by the vendor, are studied to obtain more accurate specifications of the detectors.

Increased NFAT5 expression stimulates transcription of Hsp70 in preeclamptic placentas.

OBJECTIVE: We investigated the expression of heat shock protein 70 (Hsp70), nuclear factor of activated T cells 5 (NFAT5), and hypoxia-induced factor-1α (HIF-1α) in the placentas of normal and preeclamptic pregnancies and in human placental hypoxia models in vitro to examine the regulatory mechanisms of placental Hsp70 expression. METHODS: The expression levels of HIF-1α, NFAT5, and Hsp70 were examined in placental samples from 10 females with preeclampsia and 10 normotensive control patients and in human choriocarcinoma trophoblast cells treated with 1 mM CoCl2 by western blotting. Using models of placental hypoxia, pharmacological inhibition of HIF-1α with chetomin and shRNA knockdown and overexpression of NFAT5 were performed to investigate the roles of HIF-1α and NFAT5 in induction of Hsp70 by placental hypoxia. RESULTS: The levels of HIF-1α, NFAT5, and Hsp70 expression were significantly higher in the preeclamptic compared to normal placentas. In the placental hypoxia models, the expression of HIF-1α, NFAT5, and Hsp70 were significantly higher after 3, 6, and 12 h of 1 mM CoCl2 treatment, respectively. Pharmacological inhibition of HIF-1α suppressed the induction of NFAT5 and Hsp70 at the protein level. shRNA knockdown of NFAT5 suppressed the induction of Hsp70 protein and overexpression of NFAT5 stimulated the induction of Hsp70 mRNA and protein in models of human placental hypoxia in vitro. CONCLUSION: HIF-1α positively regulates the induction of NFAT5 and Hsp70 by placental hypoxia and NFAT5 stimulates transcription of Hsp70 in response to placental hypoxia in models of human placental hypoxia in vitro.

The critical role of catalase in prooxidant and antioxidant function of p53.

The tumor suppressor p53 is an important regulator of intracellular reactive oxygen species (ROS) levels, although downstream mediators of p53 remain to be elucidated. Here, we show that p53 and its downstream targets, p53-inducible ribonucleotide reductase (p53R2) and p53-inducible gene 3 (PIG3), physically and functionally interact with catalase for efficient regulation of intracellular ROS, depending on stress intensity. Under physiological conditions, the antioxidant functions of p53 are mediated by p53R2, which maintains increased catalase activity and thereby protects against endogenous ROS. After genotoxic stress, high levels of p53 and PIG3 cooperate to inhibit catalase activity, leading to a shift in the oxidant/antioxidant balance toward an oxidative status, which could augment apoptotic cell death. These results highlight the essential role of catalase in p53-mediated ROS regulation and suggest that the p53/p53R2-catalase and p53/PIG3-catalase pathways are critically involved in intracellular ROS regulation under physiological conditions and during the response to DNA damage, respectively.

Inhibition of the PI3K-Akt pathway suppresses sFlt1 expression in human placental hypoxia models in vitro.

OBJECTIVE: Although elevated expression of soluble fms-like tyrosine kinase 1 (sFlt1) plays a major role in the pathogenesis of pre-eclampsia, it is unclear how hypoxia regulates placental sFlt1 expression. Thus, we investigated sFlt1 expression in placentas from normal and preeclamptic pregnancies and in human placental hypoxia models in vitro to examine the role of the PI3K-Akt pathway in regulating the expression of this molecule. METHODS: We examined the expression of VEGF, PlGF, sFlt1, PI3K, Akt, and HIF-1 in placental samples from ten women with pre-eclampsia and ten normotensive control patients and in human choriocarcinoma trophoblast cells treated with 600muM CoCl(2) by Western blotting. Using models of placental hypoxia, we also determined whether inhibition of the PI3K-Akt pathway plays a direct role in regulating the expression of sFlt1. RESULTS: The VEGF, PlGF, sFlt1, PI3K, Akt, and HIF-1 levels were significantly higher in the preeclamptic placentas than the normal placentas. In the placental hypoxia models, the expression of VEGF and PlGF increased in a time-dependent manner, whereas the expression of sFlt1 plateaued after 3h of CoCl(2) treatment. The expression levels of p-Akt and PI3K were maximal after 6 and 12h of CoCl(2) treatment, respectively. The expression of HIF-1alpha increased in a time-dependent manner with CoCl(2) treatment. Inhibition of the PI3K-Akt pathway with the PI3K-specific inhibitor LY294002 leads to decreased sFlt1 levels and unchanged or increased VEGF and PlGF levels. CONCLUSION: Inhibition of the PI3K-Akt pathway may be a useful therapeutic approach, if it were to decrease sFlt1 secretion without inhibiting VEGF or PlGF secretion. This pathway provides a potential target for a new treatment strategy in patients with pre-eclampsia.

The p53-inducible gene 3 (PIG3) contributes to early cellular response to DNA damage.

The p53-inducible gene 3 (PIG3) is originally isolated as a p53 downstream target gene, but its function remains unknown. Here, we report a role of PIG3 in the activation of DNA damage checkpoints, after UV irradiation or radiomimetic drug neocarzinostatin (NCS). We show that depletion of endogenous PIG3 sensitizes cells to DNA damage agents, and impaired DNA repair. PIG3 depletion also allows for UV- and NCS-resistant DNA synthesis and permits cells to progress into mitosis, indicating that PIG3 knockdown can suppress intra-S phase and G2/M checkpoints. PIG3-depleted cells show reduced Chk1 and Chk2 phosphorylation after DNA damage, which may directly contribute to checkpoint bypass. PIG3 exhibited diffuse nuclear staining in the majority of untreated cells and forms discrete nuclear foci in response to DNA damage. PIG3 colocalizes with gamma-H2AX and 53BP1 to sites of DNA damage after DNA damage, and binds to a gamma-H2AX. Notably, PIG3 depletion decreases the efficient induction and maintenance of H2AX phosphorylation after DNA damage. Moreover, PIG3 contributes to the recruitment of 53BP1, Mre11, Rad50 and Nbs1 to the sites of DNA break lesions in response to DNA damage. Our combined results suggest that PIG3 is a critical component of the DNA damage response pathway and has a direct role in the transmission of the DNA damage signal from damaged DNA to the intra-S and G2/M checkpoint machinery in human cells.

PKC delta in preeclamptic placentas promotes Bax dissociation from 14-3-3 zeta through 14-3-3 zeta phosphorylation.

OBJECTIVE: We investigated placental apoptosis and the expression of and interactions between 14-3-3 and Bcl-2 family proteins during preeclampsia. In addition, we explored the mechanism of Bax dissociation from 14-3-3, hypothesizing that PKC-mediated phosphorylation of 14-3-3 results in dissociation of Bax from 14-3-3 proteins, and leads to apoptosis. METHODS: Placental samples from 10 women with preeclampsia and 10 normotensive control patients were analyzed using M30-specific immunohistochemistry to assess placental apoptosis. Biochemical markers of cellular apoptosis, such as cleaved caspase-3, Bax, Bcl-2, 14-3-3, and PKC were followed by Western blotting. Interaction of 14-3-3 proteins with Bax and with PKC was assessed by immunoprecipitation. RESULTS: M30-positive cells were widespread in the preeclamptic placentas. The levels of cleaved caspase-3, Bax, 14-3-3 zeta, phospho-(Ser)-14-3-3, and PKC delta were significantly higher in the preeclamptic placentas than in normal placentas. Preeclampsia was also associated with weaker interactions between 14-3-3 zeta and Bax and stronger interactions between 14-3-3 zeta and PKC delta. CONCLUSION: Our results suggest that PKC delta in preeclamptic placentas promotes Bax dissociation from 14-3-3 zeta through the phosphorylation of 14-3-3 zeta. This finding may at least in part explain the apoptosis-inducing activity of PKC delta, revealing the important role of PKC delta in the development of apoptosis-related diseases such as preeclampsia.

Isolation of Escherichia coli O157:H7 from the gall bladder of inoculated and naturally-infected cattle.

To determine if Escherichia coli O157:H7 is capable of residing in the gall bladder of cattle, inoculation studies were conducted with O157:H7 strain 86-24 in weaned Holstein calves. Strain 86-24 was isolated from the gall bladders of five calves 36 days after inoculation. Two other calves contained the inoculation strain in the distal colon but the organism was absent in their gall bladders. A second trial in which the calves were euthanized 15 days after inoculation found strain 86-24 in six of seven inoculated calves but only in colon and/or rumen samples. In a third trial that inoculated eight calves with a four-strain cocktail of O157:H7 strains, the gall bladders from all eight animals were positive 9 days after inoculation. The colon and rumen samples from these calves were also positive. E. coli O157:H7 isolates recovered from bile samples and subtyped by pulsed field gel electrophoresis found that three of the four inoculation strains were present in one or more of the calves. Thus, residence in the gall bladder is not restricted to a single strain. Additional evidence of the ability to localize in the gall bladder of cattle was provided by testing the bile from 150 gall bladders (five collection dates, 30 samples each) obtained at an abbatoir and the isolation of E. coli O157:H7 from four samples (2.7%). This study establishes that E. coli O157:H7 can reside transiently or permanently at a low level in the gall bladder of cattle.

Bran extracts from pigmented rice seeds inhibit tumor promotion in lymphoblastoid B cells by phorbol ester.

Using flow cytometry, we quantitatively evaluated anti-tumor-promoting activity of rice bran extracts by measuring inhibition of Epstein-Barr virus early-antigen activation (EBV-EA) induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). This assay measures anti-tumor-promoting activity and cytotoxicity of target substances using the same batch of cells. Using this short-term procedure, we have determined the anti-tumor-promoting activity of 70% ethanol-water extracts of bran (outer layer) from seeds of five pigmented rice cultivars: Jumlalocal-1, DZ 78, Elwee, LK1-3-6-12-1-1, and LK1A-2-12-1-1. The results show that, compared to an extract from the non-pigmented white cooking rice variety Chuchung, the extracts from the pigmented varieties strongly inhibited phorbol ester-induced tumor promotion in marmoset lymphoblastoid cells B95-8 in vitro. These findings may facilitate development and use of new health-promoting rice varieties.

External beam radiation followed by planned neck dissection and brachytherapy for base of tongue squamous cell carcinoma.

BACKGROUND: Surgical resection of tongue base cancer can leave the patient with significant functional deficits. Other therapies, such as external beam radiation followed by neck dissection and radiation implants, have shown equal tumor control with good functional outcome. METHODS: Between March 1991 and July 1999, 12 patients at Oregon Health Sciences University, the Portland Veterans Administration Medical Center and West Virginia University School of Medicine Hospital were treated with external beam radiation followed by neck dissection and Ir192 implants. Two patients had T1 disease, two had T2, five patients had T3 tumors, and three had T4 tumors. Six had N2a necks, three had N2b necks, and three had N2c. Follow-up ranged from 13 months to 8 years. RESULTS: After external beam radiation, five patients had complete response and seven had partial response in the neck without complications. One patient underwent a unilateral radical neck dissection, eight had unilateral selective neck dissections involving levels I to IV, and three had dissections involving levels I to III. One of the five patients who had a complete clinical response in the neck had pathologically positive nodes. One patient had a pulmonary embolus that was treated and had no permanent sequelae. There were three complications from brachytherapy. Two patients had soft tissue necrosis at the primary site and one patient had radionecrosis of the mandible. All healed without further therapy. One patient had persistent disease and underwent a partial glossectomy but died of local disease. Distant metastasis developed in two patients. All others show no evidence of disease and are able to eat a normal diet by mouth. CONCLUSION: This combination of therapies should be considered when treating tongue base cancer.

Identification of natural rubber and characterization of rubber biosynthetic activity in fig tree.

Natural rubber was extracted from the fig tree (Ficus carica) cultivated in Korea as part of a survey of rubber producing plants. Fourier transform infrared and (13)C nuclear magnetic resonance analysis of samples prepared by successive extraction with acetone and benzene confirmed that the benzene-soluble residues are natural rubber, cis-1,4-polyisoprene. The rubber content in the latex of fig tree was about 4%, whereas the rubber content in the bark, leaf, and fruit was 0.3%, 0.1%, and 0.1%, respectively. Gel-permeation chromatography revealed that the molecular size of the natural rubber from fig tree is about 190 kD. Similar to rubber tree (Hevea brasiliensis) and guayule (Parthenium argentatum Gray), rubber biosynthesis in fig tree is tightly associated with rubber particles. The rubber transferase in rubber particles exhibited a higher affinity for farnesyl pyrophosphate than for isopentenyl pyrophosphate, with apparent K(m) values of 2.8 and 228 microM, respectively. Examination of latex serum from fig tree by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed major proteins of 25 and 48 kD in size, and several proteins with molecular mass below 20 and above 100 kD. Partial N-terminal amino acid sequencing and immunochemical analyses revealed that the 25- and 48-kD proteins were novel and not related to any other suggested rubber transferases. The effect of EDTA and Mg(2+) ion on in vitro rubber biosynthesis in fig tree and rubber tree suggested that divalent metal ion present in the latex serum is an important factor in determining the different rubber biosynthetic activities in fig tree and rubber tree.

Cranial neuropathy following curative chemotherapy and radiotherapy for carcinoma of the nasopharynx.

Cranial nerve damage following head and neck radiotherapy is an unusual event. Cranial neuropathy following concurrent chemotherapy and radiotherapy is unreported. The authors report a case of a 54-year-old man treated with curative chemotherapy and radiotherapy for a stage III nasopharyngeal carcinoma who developed an unilateral hypoglossal nerve palsy five years after therapy. Follow-up examination and magnetic resonance imaging (MRI) show no evidence of recurrent disease. Hypoglossal nerve injury occurring after head and neck radiotherapy is an indirect effect due to progressive soft tissue fibrosis and loss of vascularity. This process develops over years leading to nerve entrapment and permanent damage. Cranial nerve palsies, including damage to the hypoglossal nerve, can develop years after therapy with no evidence of tumour recurrence. Chemotherapy and radiotherapy have improved progression-free and overall survival in advanced nasopharyngeal cancer. As more patients achieve long-term tumour control following chemotherapy and radiotherapy, we must be cognizant of potential late injury to cranial nerves.

In vitro study on antioxidant potential of various drugs used in the perioperative period.

BACKGROUND: Since surgical trauma not only intensifies the oxidative stress by generating reactive oxygen species (ROS), but also weakens the biological defense system against ROS attack, the antioxidant activity of drugs used during the perioperative period, which possibly normalizes the impaired redox state in the patient, is of fundamental importance and great clinical interest. METHODS: We have applied the phycoerythrin fluorescence-based assay, in which 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH)-generated peroxyl radical attacks B-phycoerythrin (B-PE) to lead to a sensitive decrease in its fluorescence intensity linearly, to evaluate the antioxidant activity of major drugs in anesthetic practice. RESULTS: By the protective effect on B-PE fluorescence decay, the antioxidant activities of the drugs were classified into three groups: Group I drugs, which only slowed B-PE fluorescence decay (nicardipine, verapamil, diltiazem, ephedrine, aminophylline, vecuronium, lidocaine, mepivacaine, midazolam, thiamylal, droperidol, ketamine, hydroxyzine, butorphanol, prednisolone, hydrocortisone, betamethasone, dexamethasone, methylprednisolone, and furosemide); Group II drugs, which protected B-PE oxidation completely and stopped fluorescence decay in a certain duration (dopamine, epinephrine, norepinephrine, dobutamine, isoproterenol, and buprenorphine); and Group III drugs, which had no protective effect on B-PE oxidation (nitroglycerin, prostaglandin E1, neostigmine, pancuronium, suxamethonium, atropine, bupivacaine, pentazocine, and heparin). CONCLUSION: These results indicate that Group I and II drugs exert some antioxidant activity in vitro, as measured by their protection of fluorescence decay of B-PE. Careful consideration of these properties might, then, serve to facilitate more efficient drug application.

[Cephalad movement of the carina due to CD (Cotrel-Dubousset) instrumentation for idiopathic scoliosis].

Recently we experienced a case of tracheal tube obstruction due to the upward displacement of carina during CD (Cotrel-Dubousset) instrumentation for idiopathic scoliosis. Therefore, we hypothesized that CD instrumentation may affect the position of the carina as a result of correction of chest deformity, and studied the displacement of carina before and after CD instrumentation on chest X-ray in 12 patients with scoliosis. The length between the bottom of the 6th cervical vertebral body and the carina was measured by using chest X-ray before and after the correction. In all patients studied, cephalad movement of the carina was observed, and it was more than 1.00 cm in 5 patients. The maximal movement of the carina was 1.59 cm. The tracheal length after the correction was significantly shorter than before (P < 0.01). These results suggest that the carina may be displaced upwards due to the correction by the CD instrumentation, and that such induced displacement may affect the tracheal tube position and obstruct the tube during the operation.

Inactivation of alcohol dehydrogenase in rice seedlings is related to a microsomal fatty acid alpha-oxidation system.

The selective inactivation of alcohol dehydrogenase by the inactivator found in the microsomal fraction of rice (Oryza sativa) seedlings growing in air (Shimomura, S. & Beevers, H. (1983) Plant Physiol. 71, 736-741; 742-746) was further studied. This inactivation was found to be essentially dependent on the presence of free fatty acids. The specificity for fatty acids and the inhibitory effects of imidazole, 2-hydroxyfatty acids and dithiothreitol on the inactivation were all consistent with the properties of the fatty acid alpha-oxidation system in plants. Both O2 consumption and decarboxylation of fatty acid due to alpha-oxidation were also demonstrated in rice microsomes. When purified rice alcohol dehydrogenase was added to the alpha-oxidation system in rice microsomes, the decarboxylation of fatty acid was inhibited, and the cysteinyl residues of alcohol dehydrogenase were oxidized. The oxidation of two cysteinyl residues per monomer resulted in the complete inactivation of the enzyme. The activity of the inactivator in the isolated microsomes was gradually lost during storage and was rapidly lost upon heating. The inactivation of alcohol dehydrogenase was observed even when the enzyme was separated from microsomes by a dialysis membrane. These results indicate that the inactivation of alcohol dehydrogenase is closely related to fatty acid alpha-oxidation. We postulate that an intermediate of alpha-oxidation is the inactivator.