Studies on macrolide antibiotics I. Synthesis and antibacterial activity of erythromycin A 9-O-substituted oxime ether derivatives against Mycobacterium avium complex.

A series of erythromycin A 9-O-substituted oxime ether derivatives have been synthesized and evaluated for antibacterial activity against Mycobacterium avium complex (MAC) and Staphylococcus aureus. These compounds possessed stronger in vitro activity against MAC including macrolide-resistant strains than clarithromycin (2), although in vitro antibacterial activities of these compounds were less than that of 2 against Staphylococcus aureus. Our studies found that several factors contribute to the antibacterial activity against MAC. The length and spatial orientation of the substituent at 9-position were found to significantly influenced the anti-MAC activity, especially against macrolide-resistant strains. Of all the compounds prepared, erythromycin A 9-[O-(4-phenylbutyl)oxime] (12q) and erythromycin A 9-[O-(3-phenoxypropyl)oxime] (12t) possessed 16 times stronger antibacterial activity than 2 against clarithromycin-resistant strains. Surprisingly, the minimum inhibitory concentrations (MICs) of 12q and 12t against the resistant strains were almost same as those against the susceptible strains. These results suggest that the erythromycin A 9-O-substituted oxime ether derivatives would be promising macrolide antibiotics.

The Fontan procedure in adults.

SETTING: Tertiary adult congenital cardiac referral centre. DESIGN: Retrospective cross sectional analysis. OBJECTIVES: To report our 20 year experience with adult Fontan operations, and to compare late outcome in patients with single ventricle with definitive aortopulmonary or cavopulmonary shunt palliation. PATIENTS AND MAIN OUTCOME MEASURES: Patients older than 18 years undergoing Fontan operation between 1 January 1982 and 31 December 1998 were identified. Mortality and late outcome were derived from hospital records. These patients were compared with a cohort of 50 adults with single ventricle who had not undergone a Fontan operation. RESULTS: 61 adults, median age 36 years (range 18-47 years), with a median follow up of 10 years (range 0-21 years) were identified. Actuarial survival was 80% at one year, 76% at five years, 72% at 10 years, and 67% at 15 years. Compared with before the Fontan operation, more patients were in New York Heart Association (NYHA) functional class I or II at the latest follow up (80% v 58%, p < 0.001). Systolic ventricular function deteriorated during follow up such that 34% had moderate to severe ventricular dysfunction at the latest follow up compared with 5% before Fontan (p < 0.001). Arrhythmia increased with time (10% before Fontan v 57% after 10 years, p < 0.001). Fontan patients had improved NYHA functional class, ventricular function, atrioventricular regurgitation, and fewer arrhythmias than the non-Fontan group at the latest follow up. CONCLUSION: The Fontan operation in adults has acceptable early and late mortality. Functional class, systolic ventricular function, atrioventricular regurgitation, and arrhythmia deteriorate late after surgery but to a lesser degree than in non-Fontan patients with a single ventricle.

Functional evidence for a telomerase repressor gene on human chromosome 10p15.1.

Based on the sites of frequent allelic loss in hepatocellular carcinoma, five normal human chromosomes (2, 4, 5, 10 and 16) were transferred individually into a telomerase-positive human hepatocellular carcinoma cell line, Li7HM, by microcell-mediated chromosome transfer (MMCT). Chromosome 10, but not the others, repressed telomerase activity immediately and stopped cell growth after 50 population doublings (PDs). Loss of the transferred 10p loci resulted in the emergence of revertant cells that continued to proliferate and expressed telomerase activity, suggesting the presence of a telomerase repressor gene on this chromosomal arm. Transfer of a series of defined fragments from chromosome 10p successfully narrowed down the responsible region: a 28.9-cM region on 10p15 (between WI-4752 and D10S249), but not a 26.2-cM region (between D10S1728 and D10S249), caused repression of telomerase activity and progressive telomere shortening. A strong correlation between the expression level of telomerase catalytic subunit gene (hTERT) and telomerase activity was observed. These findings suggest that a novel telomerase repressor gene which controls the expression of hTERT is located on the 2.7-cM region (between WI-4752 and D10S1728) on chromosome 10p15.1.

Increase of peripheral natural killer T cells in hemodialysis patients.

AIMS: Patients with end-stage renal disease often present a state of immunodeficiency. To elucidate the involvement of natural killer T (NKT) cells in the development of pathologies associated with uremia, we examined the percentages and characteristics of NKT cells (CD56+ T cells and CD57+ T cells) in peripheral lymphocites from hemodialysis (HD) patients. MATERIALS AND METHODS: Thirty-three patients who had undergone HD therapy for 2 to 5 years (group A, n = 15) or for more than 10 years (group B, n = 18) and 17 normal controls participated in this study. Cell surface antigens of lymphocytes were analyzed using immunofluorescent flow cytometry. RESULTS: The percentage of peripheral CD56+ T cells was increased in group A and B compared with controls, and that of CD57+ T cells was increased in group B compared with controls and group A. The most abundant population in CD56+ T cells was DN T cells, and that in CD57+ T cells was CD8+ T cells. In CD57+ T cells, a higher proportion of CD8+ T cells and a lower proportion of DN T cells were found in group B compared with controls. CONCLUSIONS: We detected increases of CD56+ T cells and CD57+ T cells in HD patients. The elevation of NKT cells might affect some complications associated with HD.

Mass spectrometry proves under-O-glycosylation of glomerular IgA1 in IgA nephropathy.

BACKGROUND: The IgA1 molecule, which is predominantly deposited in glomeruli in IgA nephropathy (IgAN), is a unique serum glycoprotein because it has O-glycan side chains in its hinge region. Our study was conducted to investigate the O-glycan structure in the glomerular IgA1 in IgAN. METHODS: The IgA1 was separated from 290 renal biopsy specimens of 278 IgAN patients and from four serum IgA1 samples (IgAN, 2; control, 2). The variety of O-glycan glycoform was determined by estimating the precise molecular weights of the IgA1 hinge glycopeptides using matrix-assisted laser desorption ionization time of flight mass spectrometry. RESULTS: The peak distribution of IgA1 hinge glycopeptides clearly shifted to lesser molecular weights in both glomerular and serum IgA1 in IgAN compared with the serum IgA1 of controls. In the five major peaks of IgA1 hinge glycopeptides in each sample, the numbers of carbohydrates composing O-glycans (GalNAc, Gal, and NANA) in the deposited and serum IgA1 in IgAN patients were significantly fewer than those in the serum IgA1 in the control groups. CONCLUSION: The O-glycan side chains in the hinge of the glomerular IgA1 were highly underglycosylated in IgAN. These results indicate that the decreased sialylation and galactosylation of the IgA1 hinge glycopeptides play a crucial role in its glomerular deposition in IgAN.

20-Hydroxyeicosatetraenoic acid mediates angiotensin ii-induced phospholipase d activation in vascular smooth muscle cells.

Angiotensin II (Ang II) activates cytosolic phospholipase A(2) (cPLA(2)) and phospholipase D (PLD) in rabbit vascular smooth muscle cells (VSMCs). Ang II also activates ras/mitogen-activated protein (MAP) kinase in VSMCs; this activation is mediated by 20-hydroxyeicosatetraenoic acid (HETE) and 12(S)-HETE, which are metabolites of arachidonic acid generated by cytochrome P450 4A and lipoxygenase, respectively, produced on activation of cPLA(2). The purpose of this study was to determine if Ang II-induced PLD activation in VSMCs is mediated through the ras/extracellular signal-regulating kinase (ERK) pathway by arachidonic acid metabolites that are generated consequent to cPLA(2) stimulation. Inhibitors of PLD (C(2) ceramide), phosphatidate phosphohydrolase (propranolol), and diacylglycerol lipase (RHC 80267) attenuated Ang II-induced arachidonic acid release. Ang II-induced PLD activation, as measured by [(3)H]phosphatidylethanol production, was inhibited by C(2) ceramide but not by propranolol or RHC 80267. Ang II-induced PLD activation was decreased by the inhibitor methyl arachidonylfluorophosphate (MAFP) and the antisense oligonucleotide of cPLA(2). Inhibitors of lipoxygenases (baicalein) and cytochrome P450 4A (ODYA) attenuated Ang II-induced PLD activation. 20-HETE and 12(S)-HETE increased PLD activity. Inhibitors of ras farnesyltransferase (FPT III and BMS-191563) and MAP kinase kinase (UO126) attenuated the increase in PLD activity elicited by 20-HETE and Ang II. PLD2 was the main isoform activated by Ang II in VSMCs. These data suggest that the CYP4A metabolite 20-HETE, which is generated from arachidonic acid after cPLA(2) activation by Ang II, stimulates the ras/MAP kinase pathway, which in turn activates PLD2 and releases further arachidonic acid for prostaglandin synthesis through the phosphatidate phosphohydrolase/diacylglycerol lipase pathway.

Simultaneous occurrence of minimal change glomerular disease, sarcoidosis and Hashimoto's thyroiditis.

We herein report a very rare case of a patient suffering from simultaneous occurrence of three immune disorders, i.e. Hashimoto's thyroiditis, sarcoidosis and minimal change glomerular disease. A 66-year-old man was admitted to our hospital for evaluation of nephrotic syndrome. Six months before admission, he was pointed out as having positive proteinuria, hypoalbuminemia and associated pretibial pitting edema. Initial laboratory data showed high gammaglobulinemia, high titers of both antimicrosomal and antithyroglobulin antibodies with normal thyroid function. Chest X-ray and CT scan revealed bilateral hilar lymphadenopathy with interstitial shadow. Ga-citrate scan disclosed positive accumulation in the thyroid glands, the mediastinum, the lungs and the kidneys. The diagnosis of minimal change nephritic syndrome and pulmonary sarcoidosis was made, based on the findings of transbronchial lung biopsy and kidney biopsy. After one and a half months of admission, thyroid function had gradually deteriorated. The histological findings of the thyroid were consistent with the features of Hashimoto's thyroiditis. Treatment with prednisolone and cyclophosphamide resulted in a decrease in urinary protein excretion, reduction in the size of mediastinal lymphadenopathy and disappearance of positive findings of Ga-citrate scan in the thyroid glands and the kidneys. Simultaneous occurrence of minimal change-glomerular disease, sarcoidosis and Hashimoto's thyroiditis in our case suggests that similar immunological abnormalities may be involved in the pathogenesis of the diseases.

Direct evidence for decreased sialylation and galactosylation of human serum IgA1 Fc O-glycosylated hinge peptides in IgA nephropathy by mass spectrometry.

Human serum immunoglobulin IgA1 is produced in bone marrow and interacts with specific cellular receptors that mediate biological events. In this study, we have analyzed the detailed glycoform structure of the human serum IgA1 Fc O-glycosylated hinge region by electrospray ionization liquid mass spectrometry. The IgA1 fragments containing the hinge glycopeptide were separated from 4 IgA nephropathy patient (IgAN) pooled sera, 10 non-IgAN pooled sera with other primary glomerulonephritides, and 5 healthy control subject pooled sera by trypsin treatment and Jacalin affinity chromatography. The molecular weights of IgA1 hinge glycopeptide were estimated using mass spectrometry, and 13 sialo and 8 asialo glycopeptide groups were identified. The results obtained clearly showed a decrease of GalNAc, Gal, and sialic acid in IgAN compared with non-IgAN and normal controls, and those strongly suggested the possibility that the decreased galactosylation and sialylation of the IgA1 hinge result in its glomerular deposition in IgAN.

Effects of lithium on the pharmacokinetics of valproate in rats.

Combined treatment with lithium and valproate has been used for bipolar disorder. However, the studied interaction between these two drugs has not been fully investigated. We therefore examined the effects of lithium on the pharmacokinetics (plasma disappearance, metabolism and urinary excretion) of valproate in rats. Lithium (2 mEq kg(-1)) was administered intraperitoneally twice a day for ten days. Plasma disappearance curves of valproate (50 mg kg(-1), i.v.), valproate-metabolizing activities of UDP-glucuronosyltransferase (UGT) and cytochrome P450 (CYP) in liver microsomes and urinary excretion of free valproate and valproate-glucuronide were examined. The metabolizing activity of UGT and CYP were determined by enzyme assays and a fluorescence polarization immunoassay system. Urinary valproate-glucuronide was obtained using this system by subtracting the free level from total level, which was determined after deconjugating the sample with heat and NaOH. The half-life of plasma disappearance of valproate was 25% reduced by lithium pretreatment (0.428 +/- 0.031 h with repeated lithium pretreatment vs 0.578 +/- 0.062 h for controls). The valproate-metabolizing activity of UGT and CYP were not altered by lithium although lithium increased the urinary excretion of valproate-glucuronide. In conclusion, lithium pretreatment causes a decrease in plasma valproate levels and an increase in urinary excretion of valproate-glucuronide in rats.

The Reconstructions for Vertebral Artery Stenosis at the Origin. A Comparison between PTA and Surgical Reconstructions.

SUMMARY: To date in our hospital, surgical reconstructions and percutaneous transluminal angioplasty (PTA) were carried out in 168 patients with vertebral artery (VA) stenosis at the origin. In this article, we discuss the comparison between surgical reconstructions and PTA, especially regarding long term follow up, patency and complications. PTA is a less invasive treatment for VA stenosis at the origin than surgical reconstructions. However, restenosis after PTA occurred in 20% of the patients. On the other hand, restenosis after surgical reconstructions did not emerge even in long term follow up. An embolism after PTA occurred in 2.6% of the cases. However, the embolism occurred in only the first 10 patients of our series, after that there was no embolism. We concluded that PTA was the first choice for VA stenosis at the origin, if the angiogram did not reveal any PTA difficulty. If restenosis after PTA was performed, we selected surgical reconstruction for VA stenosis at the origin.

Peripheral deletion of gammadelta T cells in haemodialysis patients.

Many patients with end-stage renal disease have altered host defenses against infectious agents. We have demonstrated that T cells, which play an important role in the immunological response, may undergo apoptosis by the Fas system in uraemia. To elucidate whether gammadelta T cells, which function as a first defense against intracellular pathogens, are altered in number or characteristics in dialysis patients, surface expressions of TCR, LFA-1 and Fas antigen on peripheral T cells were examined by immunofluorescence analysis. We demonstrated that the proportions of peripheral gammadelta T cells are altered significantly in haemodialysis (HD) patients. Interestingly, there were marked differences in the levels of expression of LFA-1 and Fas antigen between the two types of T cells. Moreover, both the expression of LFA-1 and that of Fas antigen were enhanced significantly in HD patients compared with normal controls. These results suggest that circulating gammadelta T cells may be susceptible to activation-induced cell death in comparison with alphabeta T cells in uraemic environments.

[Clinical significance of telomerase activity in precancerous lesion of the liver (adenomatous hyperplasia)].

To understand the role of telomere dynamics in hepatocellular carcinogenesis, we examined the lengths of terminal restriction fragments (TRFs) in hepatocellular carcinoma (HCC) and surrounding tissues with chronic active hepatitis (CAH), liver cirrhosis (LC) and atypical adenomatous hyperplasia (AAH). The peak TRFs in all HCCs were significantly shorter than those of the surrounding tissues (CAH, LC). TRF in AAH was shortened and similar to that of HCC. Telomerase was examined in CAH, LC, AH, and HCC, and detected in high levels almost exclusively in HCCs. Interestingly, the intensity of telomerase activity in the AH was similar to that of HCC. Thus, the progressive shortening of telomere and the activation of telomerase may be a useful marker for the early detection of malignant progression in liver disease.

Interleukin-9 receptor alpha chain mRNA formation in CD8+ T cells producing anti-human immunodeficiency virus type 1 substance(s).

A search for gene(s) associated with anti-human immunodeficiency virus type 1 (HIV-1) activity of CD8+ T cells was attempted using molecular cloning and the relation between the anti-HIV activity of CD8+ T cells and the interleukin-9 receptor alpha chain (IL-9R-alpha) mRNA expression from the cDNA clones obtained was examined. The anti-HIV-1 activity of CD8+ T cell culture supernatants was assessed by measuring the level of HIV-1 replication of a CD4+ T cell line transfected with an infectious HIV-1 DNA clone. IL-9R-alpha mRNA was assayed by reverse transcriptase-polymerase chain reaction (RT-PCR). Of 5 cases showing high level of anti-HIV-1 activity (more than 80% suppression of HIV-1 replication), the mRNA was detected in 4 cases. Of 10 cases showing low level of anti-HIV-1 activity (less than 80% suppression of HIV-1 replication), the mRNA was detected in one case. Soluble recombinant human IL-9 receptor (rhIL-9sR) did not suppress HIV-1 replication at a concentration of 1 microgram/ml. These data suggest that the IL-9R-alpha mRNA formation in CD8+ T cells may correlate with and play some role in the anti-HIV-1 activity of CD8+ T cells from HIV-1-infected individuals.

Progressive telomere shortening and telomerase reactivation during hepatocellular carcinogenesis.

Telomeres shorten progressively with age in normal somatic cells in culture and in vivo. The maintenance of telomere length is assumed to be an obligatory step in the progression and immortalization of most human tumor cells. To understand the role of telomere dynamics in the development of hepatocellular carcinoma (HCC), we examined the length of terminal restriction fragment (TRF), as an indicator for telomere length, in HCC and surrounding tissues with chronic active hepatitis (CAH) or liver cirrhosis (LC). The study was performed in 12 hepatitis C virus (HCV) antibody-positive, 12 hepatitis B virus (HBV) antigen-positive tissues, and 4 tissue samples from virus-negative patients with HCC. The peak TRFs in all 3 types of HCC were significantly shorter than those of the surrounding tissues (i.e., LC or CAH). TRFs examined in one patient with atypical adenomatous hyperplasia (AAH) also was shortened. Thus, progressive TRF shortening occurs from normal to CAH to LC to HCC(AAH). Telomerase, an enzyme that adds repeated telomere sequences onto the chromosome ends and stabilizes telomere length in immortal cells, also was examined in tissues and detected in high levels almost exclusively in HCCs. Interestingly, the intensity of telomerase activity in the AAH case was similar to that of HCC. In addition, the telomerase activity of biopsy samples with a fine 21-gauge needle also was examined in 10 HCCs, 2 adenomatous hyperplasias (AHs), 2 LCs, and 2 CAHs. We found strong telomerase activity in all the HCCs and surprisingly in the 2 cases that were pathologically diagnosed as AH. Thus, the findings strongly suggest that persistent cell proliferation or rapid cell turnover through damage of hepatic cells result in a process of multistep hepatocellular carcinogenesis. Thus, progressive shortening of telomeres and the activation of telomerase may be a useful marker for the early detection of malignant progression in liver disease.

[Current status and problems of home care for patients with terminal cancer from the viewpoint of local clinics].

On the basis of investigations of 15 patients from our clinic with terminal cancer who were treated by home hospice care, and questionnaires filled out by their caretakers, we examined the current status and problems of the home hospice care system with respect to four phases, namely, the period of preparation for home care (hospitalization period), stable period, terminal period, and the period immediately before death. [Preparation period] The following problems occurred in this phase: introduction of pain management and nutrition management was insufficient; there were only a few cases in which the patient chose home care of his or her own will; and sufficient instructions were not given to caretakers on discharge from the hospital, with respect to medical treatment at home. [Stable period] In two of the four cases in which patients complained of severe pain, the pain was not alleviated because pain management was provided only at the outpatient clinics of the hospital, and collaboration between hospitals and our clinic was insufficient. [Terminal period] Two patients could not be admitted to the hospital upon sudden exacerbation of the condition, suggesting the need to establish a system in which large hospitals can cope with sudden exacerbation of their condition of patients with terminal cancer treated at home. [Period immediately before death] Of the 14 patients who died, 7 died at home and 7 died in the hospital or during transport to the hospital. Three subjects died within a few days after admission. Two of the subjects who died in the hospital or during transport had hoped to stay home until the last moment. Further improvement of the system is necessary in order to meet the needs of terminal cancer patients who wish to die at home. On the basis of the cases taken care of at our clinic, we examined the home care system according classification into three types; hospital-outpatient clinic type; hospital-home care type; and clinic-home care type. An ideal system for the treatment of patients with terminal cancer who hope to stay at home until the last possible moment seems to be the clinic-home care type in which a primary care team that is able to dispatch physicians and nurses, and an around-the-clock support system, are supported by outside organizations and specialists.

Thermal damage threshold of brain tissue--histological study of heated normal monkey brains.

The thermal damage threshold of normal brain tissue was evaluated from immediate and delayed histological changes caused by hyperthermia treatment of normal monkey (Macaca fuscata) brains. A 2450 MHz microwave antenna and an antenna cooling system devised by our group were used for interstitial hyperthermia treatment. The antenna within the cooling system was inserted through a small craniectomy under general anesthesia. The temperature at a reference point, 4 mm radially away from the surface of the cooling system, was maintained at 42, 43, 44, 45, or 46 degrees C for 60 minutes. Eighteen animals were treated and sacrificed immediately after the treatment, while nine animals were treated and sacrificed 7 days after the treatment. The histological changes were studied microscopically on sections stained with HE or Kluver-Barrera's method. The non-survival experiment demonstrated that areas heated at 44 degrees C or below showed no obvious irreversible changes. The survival experiment showed areas heated at 44 degrees C or above developed coagulative necrosis. These histological findings indicate that thermal damage occurs in normal brain tissue after heating at 44 degrees C or above for 60 minutes, suggesting that the safety limit for brain hyperthermia is 43 degrees C for 60 minutes.