Duplication mitosis in epithelio-glandular tissue

As duplication mitosis occurs in epithelio-glandular tissue, a different concept of histological continuity and organization of this tissue is needed. In epithelio-glandular tissue, duplication mitosis play a role in histological continuity, while maturation mitosis leads to histological organization. Duplication mitosis reproduces stem cells for the cell turnover process. The life-span of the cell copies is limited to a certain period by maturation mitosis. Conservation of duplication mitosis and its alteration to maturation mitosis are regulated by a histological mechanism in the gland crypt, involving duplication and maturation factors. The result is that epithelio-glandular tissue is maintained within a prescribed physiological volume without excessive multiplication.

Incidence of attic retraction after staged intact canal wall tympanoplasty for middle ear cholesteatoma

Incidence of retraction pocket and recurrent cholesteatoma in the attic after surgery for middle ear cholesteatoma using the staged intact canal wall technique were investigated in 95 ears of 91 patients, all of which had various degrees of bone defect in the tympanic scutum. Surgical procedures employed in the second stage for prevention of attic retraction were classified into three types: Type I, no scutumplasty; Type II, scutumplasty; Type III, scutumplasty plus mastoid obliteration. In 83 ears followed up for more than 1 year after the second stage, such retraction troubles occurred in 2 of 13 ears (15%) in Type I, 8 of 20 ears (40%) in Type II, and 24 of 50 ears (48%) in Type III. Incidence of retraction troubles was higher in Types II and III, probably because these procedures were indicated in ears with large scutum defects. Dislocation and atrophy of the graft materials, together with bone resorption around the bone defect were the main reasons for failure in scutumplasty. Dysfunction of the eustachian tube and traction of the eardrum by the scar tissue behind it may have also contributed to attic retraction. Mastoid obliteration with small blocks of hydroxyapatite was more effective in prevention of retraction troubles than that with pedicled temporalis muscle flap.

[Improvement of ischemic symptoms and cerebral blood flow after percutaneous transluminal angioplasty for renovascular hypertension. Report of a case with multiple cerebrovascular occlusive disease]

A 53-year-old male complained of frequent left motor-sensory transient ischemic attack for 4 months. On admission, he demonstrated mild right hemiparesis, dysarthria, and right hemisensory disturbance of all modalities. Cerebral angiography demonstrated complete occlusion of the left internal carotid artery just above the origin of the ophthalmic artery and a stenotic lesion at the horizontal segment of the right middle cerebral artery. Renal angiography showed severe stenosis of the right renal artery. Systolic blood pressure was over 200 mmHg and marked circadian variation of blood pressure was noted. Serum renin was 4.0 ng/ml/hr. Four months after superficial temporal artery-middle cerebral artery anastomosis, left carotid angiography showed good patency of the bypass and the ischemic symptoms completely disappeared. Single photon emission computed tomography (SPECT) showed increased cerebral blood flow (CBF), especially in the left hemisphere after surgery. Six months after the bypass surgery, he complained of mild right hemiparesis again. Shortly after percutaneous transluminal angioplasty (PTA) for renal arterial stenosis, his hemiparesis was improved and the systolic blood pressure stabilized to 150-170 mmHg. SPECT showed the CBF had also recovered in both hemispheres. The improvement in ischemic symptoms and increased CBF after PTA were probably related to stabilization of the systemic blood pressure or inhibition of serum renin-angiotensin.

Comparison of diagnostic criteria of IGT, borderline, and GDM. Blood glucose curve and IRI response

A 75-g oral glucose tolerance test (OGTT) was performed in 615 nonobese pregnant women (mean +/- SD age 29.7 +/- 4.3 yr) who were referred to the Division of Internal Medicine at our diabetes center because of glycosuria. Seventy-seven cases were found to have urinary glucose at the first trimester, 185 at the second trimester, and 353 at the third trimester. With their 75-g OGTT results, the diagnostic criteria of borderline (formulated by the Japan Diabetes Society), impaired glucose tolerance (IGT; defined by the World Health Organization [WHO]), and gestational diabetes mellitus (GDM; determined by the Japan Society of Obstetrics & Gynecology standards) were compared through blood glucose (BG) curves and immunoreactive insulin (IRI) responses. Borderline (fasting BG greater than or equal to 6.1 and less than 7.8 mM and 2-h BG greater than or equal to 6.7 and less than 11.1 mM) is neither diabetes nor normal. IGT is as referred to by the WHO. GDM exceeds two points of fasting BG greater than or equal to 5.6 mM, 1-h BG greater than or equal to 10.0 mM, or 2-h BG greater than or equal to 8.3 mM. Diabetes mellitus (DM) is as referred to by the Japan Diabetes Society (same as the WHO). The prevalence of abnormal glucose tolerance among all 615 pregnant women was 54.6% in borderline, 24.5% in IGT, 7.3% in GDM, and 3.4% in DM. The 2-h BG levels in IGT during the first trimester were higher than in borderline (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of a novel transcription unit in the human insulin-like growth factor-II gene

The human insulin-like growth factor-II (hIGF-II) gene has until now been thought to be composed of eight exons, including three independent leader exons. In the present study two additional exons, one leader exon and one alternatively used ordinate exon, have been newly identified. They were abundantly expressed in human histiocytoma tissue, generating mRNA species of about 5.0 kb in length. The new leader exon shows significant sequence similarity with the rE1 exon, previously reported to be transcribed only in the rat, and is mapped at nearly the same genomic location as in the rat. On the other hand, sequence similarity with another exon in the corresponding region of the rat genome was also found. It was, however, obvious that the rat sequence would not work as an active exon, since both splice acceptor and donor sites were deviated considerably from the consensus sequences. It has thus become apparent that the complex transcription unit of a single-copy hIGF-II gene comprises at least 10 exons, including four leader exons, one alternative exon and three common protein-coding exons.

Determination of rates and yields of interchromophore (folate----flavin) energy transfer and intermolecular (flavin----DNA) electron transfer in Escherichia coli photolyase by time-resolved fluorescence and absorption spectroscopy

Escherichia coli DNA photolyase, which photorepairs cyclobutane pyrimidine dimers, contains two chromophore cofactors, 1,5-dihydroflavin adenine dinucleotide (FADH2) and 5,10-methenyltetrahydrofolate (MTHF). Previous work has shown that MTHF is the primary photoreceptor which transfers energy to the FADH2 cofactor; the FADH2 singlet excited state then repairs the photodimer by electron transfer. In this study, we have determined the rate constants for these photophysical processes by time-resolved fluorescence and absorption spectroscopy. From time-resolved fluorescence, we find that energy transfer from MTHF to FADH2 and FADH degrees occurs at rates of 4.6 x 10(9) and 3.0 x 10(10) s-1, respectively, and electron transfer from FADH2 to a pyrimidine dimer occurs at a rate of 5.5 x 10(9) s-1. Using Förster theory for long-range energy transfer and assuming K2 = 2/3, the interchromophore distances were estimated to be 22 A in the case of the MTHF-FADH2 pair and 21 A for the MTHF-FADH degrees pair. Picosecond absorption spectroscopy identified an MTHF single state which decays to yield the first excited singlet state of FADH2. The lifetimes of MTHF and FADH2 singlets and the rates of interchromophore energy transfer, as well as the rate of electron transfer from FADH2 to DNA measured by time-resolved fluorescence, were in excellent agreement with the values obtained by picosecond laser flash photolysis. Similarly, fluorescence or absorption lifetime studies of the folate-depleted enzyme with and without photodimer suggest that FADH2, in its singlet excited state, transfers an electron to the dimer with 89% efficiency. The distance between FADH2 and the photodimer was calculated to be ca. 14 A.

[Postoperative changes in immunoreactive plasma endothelin concentrations]

We investigated postoperative changes in immunoreactive plasma endothelin (ET-1) concentrations using a highly specific and sensitive radioimmunoassay developed for this purpose. The patients were divided into two groups: 10 patients underwent subtotal-esophagectomy by combined right thoracotomy and celiotomy (EC-group), and an other 10 underwent total gastrectomy via celiotomy only (GC-group). Before operation, plasma ET concentrations in both groups were within the normal range. After operation, the mean plasma ET-1 concentration in the EC group was significantly higher than the preoperative concentration (p less than 0.01). But in the GC-group, there were no significant change. A significant correlation existed between the change in plasma ET-1 concentration and the amount of intraoperative hemorrhage (p less than 0.05). Additionally in the EC group, a significant correlation existed between plasma ET-1 concentrations after operation and the change in the atrial-natriuretic-peptide (ANP) concentration during operation (p less than 0.05). There was no correlation between ET-1 concentrations and blood pressure. We believe that the increase in the ET-1 concentration was attributable to endothelial cell injury and may increase ANP secretion. We speculate that the plasma ET-1 concentration may be a reliable index of surgical stress.

cDNA clones of Japanese hepatitis C virus genomes derived from a single patient show sequence heterogeneity

Twelve cDNA clones of Japanese hepatitis C virus (HCV) have been isolated from liver tissue of a single non-A, non-B hepatitis patient. These clones represented the non-structural domains of HCV. The degree of substitution in the nucleotide sequences and deduced amino acid sequences between these clones was 9.5 and 7.7%, respectively. This high level of substitution suggested that repeated infections of different HCVs may have occurred in the patient.

Hemangioma of the temporalis muscle: case report and review of the literature

A 51 year-old man presented with a 10-year history of a painless, slowly growing mass (35 x 25 x 15 min) in the right temporal fossa. The T1-weighted image on magnetic resonance imaging demonstrated a partial, low-signal intensity lesion with high intensity in the lower part and significant enhancement with contrast medium. The tumor, which lay within the temporal muscle, was totally excised, and histological examination confirmed the lesion to be an intramuscular, cavernous type of hemangioma. The therapeutic options are described.

Effects of atrial natriuretic peptide on endothelin-induced vasoconstriction and intracellular calcium mobilization

Mechanisms for the antagonistic action of atrial natriuretic peptide (ANP) toward endothelin were studied. We examined the effects of ANP on endothelin-induced vasoconstriction in isolated perfused kidney and the elevation of intracellular free calcium concentration using Fura-2 in cultured rat vascular smooth muscle cells (VSMC). Endothelin produced an increase in renal vascular resistance in isolated perfused kidney (2 x 10(-10) mol/l, +109%; P less than 0.01). ANP completely abolished renal vasoconstriction induced by endothelin. Endothelin produced a biphasic elevation in intracellular calcium concentration in the VSMC. Ethyleneglycol-bis-(beta-amino-ethylether)-N,N,N',N'-tetr aac etic acid (EGTA; 3 mmol/l) or nicardipine (10(-8) mol/l) decreased the sustained elevation of intracellular calcium concentration by 10(-8) mol/l endothelin to the basal level (endothelin, +15% versus EGTA + endothelin, -1%; P less than 0.05; endothelin, +18% versus nicardipine + endothelin, +5%; P less than 0.01). Pretreatment with 10(-6) mol/l ANP suppressed neither the peak phase of intracellular calcium concentration elevation (endothelin, 10(-8) mol/l, +35% versus endothelin + ANP, +31%; not significant) nor the sustained phase of intracellular calcium concentration elevation (endothelin, 10(-8) mol/l, +21% versus endothelin + ANP, +16%; not significant). ANP markedly increased the production of cyclic 3',5'-guanosine monophosphate (cGMP) in the VSMC (ANP, 10(-6) mol/l, +1100%; P less than 0.01). However, endothelin did not influence cGMP production in the presence or absence of ANP. ANP may antagonize the vasoconstrictive action of endothelin through an effect on the steps subsequent to the mobilization of intracellular calcium in the pathway of vascular smooth muscle contraction.

[Successful treatment of a pretreated elderly case of small-cell lung carcinoma with continuous five-day intravenous infusion of cisplatin plus etoposide]

A 78-year-old man was admitted to our hospital with dyspnea in June 1988, and diagnosed as having small-cell lung carcinoma by cytological findings of pleural effusion. He was treated three times with CAV (cyclophosphamide, doxorubicin, vincristine) therapy and a partial response was achieved. In March 1989, he was again admitted complaining of right dull hypochondralgia accompanied by enlargement of primary tumor in the right lower lobe of the lung and metastases to mediastinal and intraabdominal lymph nodes. Because it was an aged and recurrent case, he was treated with continuous five-day infusion of etoposide, 30 mg/m2/day and CDDP, 18.5 mg/m2/day. After the second course, subjective symptoms clearly disappeared and swelling of mediastinal and intraabdominal lymph nodes was markedly reduced on computed tomography. No severe side effects except for moderate myelosuppression, alopecia and nausea were observed. This regimen appears useful in the treatment of small-cell lung carcinoma in elderly patients.

Plasma immunoreactive endothelin-1 concentration in human fetal blood: its relation to asphyxia

To elucidate the effects of birth stress on immunoreactive endothelin-1 (irET-1) concentrations in fetal blood, we determined irET-1 levels in cord plasma in different modes of delivery associated with or without complications such as asphyxia. The irET-1 concentrations in both the umbilical artery and vein were significantly higher than those found in maternal venous blood at delivery, although there was no significant difference between preterm and full-term infants. When plasma irET-1 concentrations of healthy infants born by vaginal delivery and by cesarean section without labor were compared, the former had significantly (p less than 0.05) higher levels than the latter (15.4 +/- 4.9 pg/mL versus 11.1 +/- 3.1 pg/mL). Furthermore, umbilical venous plasma obtained from vaginally delivered infants complicated by asphyxia showed significantly (p less than 0.001) higher irET-1 levels (28.2 +/- 9.4 pg/mL) than those of nonasphyxiated infants (14.2 +/- 4.5 pg/m). These data suggest that birth stress, especially asphyxia, may contribute to the increase in fetal circulating irET-1 levels.

Atrial natriuretic peptide inhibits the aldosterone response to metoclopramide in patients with glomerular disease and essential hypertension

1. We examined the effects of metoclopramide (MCP: 10 mg i.v.) on plasma atrial natriuretic peptide (ANP) and aldosterone concentrations (PAC) and the effect of ANP on MCP-induced PAC in four patients with primary glomerular diseases and seven patients with essential hypertension. 2. MCP injection caused no significant changes in plasma ANP. MCP produced a marked increase in PAC without a significant change in plasma renin activity. 3. The increase in PAC induced by MCP injection was markedly attenuated when preceded by the infusion of ANP (25 ng/kg per min). 4. These results suggest that the dopaminergic D2 mechanism is not involved in the regulation of ANP secretion and that ANP modulates the dopaminergic regulation of aldosterone secretion.

Familial aggregation of cancer from proband cases with childhood adrenal cortical carcinoma

Family pedigree of Li-Fraumeni syndrome was investigated from probands with childhood adrenocortical carcinoma in Japan. From 47 probands, 7 families had 3 or more cancer cases at ages less than 45 years within the first generation; one satisfied Li's original criteria, two were acceptable because of multiple primary cancer in the probands, and others showed an aggregation of cancers with onsets at early ages, though no sarcoma of mesenchymal origin was found. A significantly higher occurrence of cancer in the mothers of the probands, especially of the breast, was consistent with reports from the USA, and liver cancer, osteosarcoma and lung cancer among family members under the age of 45 also showed a higher frequency than in the general population. Similarities and differences between Japanese and Caucasian cases are discussed.

Cellular mechanism of endothelin-1 release by angiotensin and vasopressin

Release of endothelin-1, a novel potent vasoconstrictor peptide originally isolated from endothelial cells, from cultured bovine endothelial cells has been shown to be stimulated by arginine vasopressin and angiotensin II. To elucidate the cellular mechanism by which endothelin-1 is released by these vasoconstrictors, we tested the effects of several compounds on the agonist-induced endothelin-1 release and studied the changes of cytosolic free Ca2+ concentrations and phosphoinositide breakdown by these agonists in cultured bovine endothelial cells. Protein kinase C inhibitors (H-7, staurosporine), an intracellular Ca2+ chelator, and an inhibitor of phospholipase C (neomycin), all abolished the agonist-induced endothelin-1 release, whereas the Ca2+ channel blocker nicardipine was ineffective. Although synthetic 1,2-diglyceride (diolein) dose dependently stimulated endothelin-1 release, downregulation of protein kinase C after pretreatment with phorbol ester resulted in decreased effects to increase endothelin-1 release by the agonists. Both arginine vasopressin and angiotensin II induced immediate and transient increases in intracellular Ca2+ levels of fura-2-loaded endothelial cells as well as formation of inositol trisphosphate; the agonist-induced intracellular Ca2+ increases were not affected either by nicardipine or by chelating extracellular Ca2+. The arginine vasopressin- and angiotensin II-induced intracellular Ca2+ increases, inositol trisphosphate formation, and endothelin-1 release were completely abolished by V1-receptor antagonist and saralasin, respectively. It is concluded that arginine vasopressin and angiotensin II stimulate the release of endothelin-1 by a common mechanism, involving receptor-mediated mobilization of intracellular Ca2+ and activation of protein kinase C in endothelial cells.

Inducement of antibody that mimics insulin action on insulin receptor by insulin autoantibody directed at determinant at asparagine site on human insulin B chain

We previously showed that purified human IgG1 insulin autoantibody (IAA) from the serum of male patient T.H. with insulin autoimmune syndrome is directed at a determinant at the asparagine site on the human insulin B chain. An anti-idiotypic antibody (anti-TH) that inhibited TH-IAA binding to human insulin was obtained by immunizing BALB/c mice with TH-IAA. Anti-TH bound to viable IM-9 cells and the purified insulin receptor from IM-9 cells. Anti-TH binding to IM-9 cells and the insulin receptor was inhibited by TH-IAA but not by human IgG. Moreover, incubation of HepG2 cells with anti-TH had an inhibitory effect on insulin binding to HepG2 cells. Anti-TH, like insulin, stimulated amino acid uptake in HepG2 cells. These findings indicate that the conformation of TH-IAA idiotope is a mirror image of the determinant on the insulin B chain, the binding site for TH-IAA on anti-TH is also related to the insulin binding site on the insulin receptor, and anti-TH mimics insulin action on the insulin receptor.

[Internal sclerostomy with a high-powered argon laser]

A full-thickness sclerostomy from the anterior chamber to the subconjunctival space was created in 9 eyes of 7 rhesus monkeys using an argon endolaser. After the injection of sodium hyaluronate into the subconjunctival space and the anterior chamber, a 300 microns fiberoptic fiber coupled with an argon laser (HGM, model 20) was inserted to the anterior chamber and positioned at the trabecular meshwork. A patent sclerostomy was created in all 9 eyes by 1 to 3 laser pulses with an energy of 4W with a duration of 0.5 second. Preoperative intraocular pressure in treated eyes and untreated eyes, measured with a pneumatic tonometer, was the same. After one month, the intraocular pressure of the treated eyes was 4.6 +/- 0.4mmHg lower than that of the untreated eyes. Histologic study revealed that the sclerostomies with a diameter of 200-300 microns from the anterior chamber opening to the subconjunctival space were patent at one month after the treatment. Internal sclerostomy with a high powered argon endolaser may hold potential as a new filtering procedure which can easily be performed with a minimum of conjunctival damage.

Endothelin-1 induces hypertrophy with enhanced expression of muscle-specific genes in cultured neonatal rat cardiomyocytes

To determine whether endothelin-1 (ET-1) induces hypertrophy of cardiomyocytes, the effects of ET-1 on the expression of muscle-specific genes and a proto-oncogene, c-fos, in cultured neonatal rat cardiomyocytes were examined by Northern blot analysis. ET-1 (10(-7) M) induced about twofold to fourfold increases in the gene expression of myosin light chain 2, alpha-actin, and troponin I after 6 hours, which continued up to 24 hours. The ET-1-induced increases in mRNA levels for these muscle-specific genes were dose dependent (10(-9) to 10(-7) M). Run-on transcriptional assay showed that the changes in mRNA level for three muscle-specific genes were regulated, at least in part, at the transcriptional level. 12-O-Tetradecanoylphorbol 13-acetate (TPA), a potent protein kinase C activator, and the Ca2+ ionophore ionomycin also increased mRNA levels of three muscle-specific genes. ET-1, TPA, and ionomycin similarly induced the expression of c-fos after 30 minutes, which returned to an undetectable level after 6 hours. ET-1 remarkably and dose-dependently stimulated accumulation of total inositol phosphates in cardiomyocytes. Morphometrical evaluation showed that ET-1 significantly increased surface area of cardiomyocytes without cell proliferation. ET-1 also dose-dependently stimulated the synthesis of protein and DNA, which was unaffected by the L-type calcium channel blocker nicardipine. These data suggest that ET-1 induces hypertrophy of cardiomyocytes associated with the induction of muscle-specific gene transcripts through the possible involvement of protein kinase C activation or intracellular Ca2+ mobilization.

Suppression of the natriuretic effects of exogenous atrial natriuretic peptide in animals with total artificial hearts

Atrial natriuretic peptide (ANP) was administered intravenously to three goats at a dose of 0.1 micrograms/kg/min for 40 min both before total artificial heart (TAH) placement and at 1, 7, and 14 postoperative weeks to determine whether exogenous ANP exhibits the same effect on animals with TAHs as it does on normal animals. No significant changes in the increases in plasma levels of ANP and cyclic guanosine monophosphate (c-GMP) were observed during ANP administration after TAH insertion. In preoperative animals, urine volume and urinary sodium excretion increased greatly during ANP administration, but this natriuretic effect was strongly suppressed in TAH animals. The changes in the decreases in arterial pressure and in central venous pressure (CVP) or right atrial pressure that occurred during the administration of ANP were not significant either pre- or post-operatively. Thus, only the natriuretic effect of ANP on the kidney was significantly suppressed in TAH animals, which might be due to some down-regulation of ANP receptors in the kidney, the production of some antagonists of ANP, sympathetic hypertonicity, or the elevation of CVP.

Appearance of beta-human atrial natriuretic peptide in collagen disease

To elucidate the circulating forms of human atrial natriuretic peptide (hANP) in collagen disease, we analysed plasma samples obtained from 21 patients with systemic lupus erythematosus, rheumatoid arthritis or progressive systemic sclerosis with no clinical evidence of cardiac involvement. The findings were compared with those obtained from 21 healthy control subjects. Plasma hANP-like immunoreactivity was normal in all but three of the controls and in two patients with the nephrotic syndrome due to lupus nephritis. Reverse-phase high-performance liquid chromatography, gel permeation chromatography and subsequent radioimmunoassay for hANP revealed that the circulating hANP consisted of alpha-hANP, beta-hANP and gamma-hANP in the patients with collagen disease whereas alpha-hANP predominated in the control group. beta-hANP appeared in 18 of the 21 patients but was not observed in the controls. These data suggest that beta-hANP circulates in the plasma of patients with collagen disease even when no myocardial involvement is apparent and that the appearance of beta-hANP is not always associated with an increase in total plasma hANP-like immunoreactivity. Thus the appearance of beta-hANP in plasma is not a phenomenon specific to congestive heart failure.

Vascular eicosanoid production in experimental hypertensive rats with different mechanisms

This study investigated the release of prostacyclin (PGI2) and thromboxane A2 (TXA2) from the aortic walls of various experimental hypertensive rats, e.g. spontaneously hypertensive rats (SHR), Dahl salt-sensitive (Dahl S) rats, deoxycorticosterone (DOCA)-salt hypertensive rats and renovascular (2-kidney, 1-clip (2K1C) and 1-kidney, 1-clip (1K1C] hypertensive rats. The PGI2 generation was increased significantly in these hypertensive models, irrespective of the hypertensive mechanisms, when they developed established hypertension. Dahl S rats, having an impaired PGI2 production on a low salt diet, restored PGI2 generating capacity to the control level of Dahl salt-resistant rats when they were fed a high salt diet and developed salt-induced hypertension. On the other hand, the TXA2 generation in the vascular walls was enhanced particularly in rat models for genetic hypertension, and this system was unaltered in the models for secondary hypertension, e.g. DOCA-salt and renovascular hypertension. Thus, it is suggested that the elevation of blood pressure is associated with an increase in vascular PGI2 production, and that the increased vascular TXA2 production is a characteristic feature of genetic hypertension.