Follicular dendritic cell dysfunction and disorganization of lymphoid structures in MRL/lpr mice

The follicular dendritic cell (FDC) in secondary lymphoid organs plays a key role in the function of the germinal center (GC) of the lymphoid follicle (LF) for regulation of the humoral immune response. MRL MpJ-lpr/lpr (MRL/lpr) mice, which have an abnormal humoral immune response, are a model for autoimmune disease. The present study was undertaken to investigate FDC dysfunction and LF disorganization in the spleen and lymph nodes of MRL/lpr mice. In 12-week-old MRL/lpr mice, antigen (Ag) trapping of FDC and half-life of trapped Ag on FDC was reduced. Although immunohistochemistry revealed well-developed FDC networks positive for complement receptors and having in vitro immune complex trapping in cryostat sections, Ag-trapping was not detected in 16-week-old MRL/lpr mice. Moreover a marked decrease in the number of GC and that of GC cell of residual GC in the MRL/lpr mice was observed by 12 weeks of age. Also reduced expression of intercellular adhesion molecule-1, FcgammaRII/III, and FDC-specific Ag (FDC-M1) on FDC was detected in 16-week-old MRL/lpr mice. The accumulation of double negative (CD4-CD8-) T cells, which is a characteristic feature of MRL/lpr mice, was observed around LF; however they did not infiltrate the LF and FDC network. In conclusion the loss of Ag-trapping on FDC and simultaneous disorganization of the lymphoid structure may be related closely to the immunologic abnormality observed in MRL/lpr mice.

A gene for fluctuating, progressive autosomal dominant nonsyndromic hearing loss, DFNA16, maps to chromosome 2q23-24.3

The sixteenth gene to cause autosomal dominant nonsyndromic hearing loss (ADNSHL), DFNA16, maps to chromosome 2q23-24.3 and is tightly linked to markers in the D2S2380-D2S335 interval. DFNA16 is unique in that it results in the only form of ADNSHL in which the phenotype includes rapidly progressing and fluctuating hearing loss that appears to respond to steroid therapy. This observation suggests that it may be possible to stabilize hearing through medical intervention, once the biophysiology of deafness due to DFNA16 is clarified. Especially intriguing is the localization of several voltage-gated sodium-channel genes to the DFNA16 interval. These cationic channels are excellent positional and functional DFNA16 candidate genes.

Volatile anesthetics reduce calcium current in parasympathetic neurons from bullfrog hearts

Although the autonomic nervous system regulates cardiac function, the cellular mechanism(s) of general anesthetics on the activities of parasympathetic neurons have not been directly assessed. We therefore studied the volatile anesthetic actions on the Ca2+ current of parasympathetic neurons isolated from bullfrog hearts. Neurons were enzymatically isolated from the interatrial septum of bullfrog heart and maintained in a short-term tissue culture. The Ca2+ current was recorded with a whole-cell voltage-clamp method under a Na+, K+ -free condition. Isoflurane (2.5 vol%) and sevoflurane (5.0 vol%) reduced the peak amplitude of the Ca2+ current (to 79% and 72% of control, respectively) without changing the reversal potential. The curve-fit analysis of the inactivation kinetics revealed that isoflurane and sevoflurane accelerated the inactivation of the current and that isoflurane shifted the midpoint of the steady-state inactivation curve of the Ca2+ current toward negative by 13.6 mV. The results indicate that volatile anesthetics reduce the Ca2+ current of parasympathetic neurons and modify the inactivation kinetics.

IMPLICATIONS

The anesthetic reduction of the Ca2+ current of parasympathetic neurons can induce a decrease of acetylcholine release from the post-ganglionic endings. These findings, in part, account for the anesthetic attenuation of the vagal efferent activities observed in humans and experimental animals.

Comparison of survival rates of patients with nasopharyngeal carcinoma treated with radiotherapy, 5-fluorouracil and vitamin A ("FAR" therapy) vs FAR therapy plus adjunctive cisplatin and peplomycin chemotherapy

The overall survival rate (OSR) of 36 patients with nasopharyngeal carcinomas (NPC) treated at Kyushu University hospital between 1983 to 1992 was analyzed. As primary treatment, 16 patients received a combination therapy of 5-fluorouracil, vitamin A, and radiation (FAR therapy); two patients received radiotherapy only; 18 patients received FAR therapy plus adjunctive systemic chemotherapy consisting of cisplatin and peplomycin. The radiation dose to the nasopharynx was 6000 to 7050 cGy while that to the neck was 4000-6000 cGy. The 5-year OSR of all the patients was 49%. Histological type (moderately differentiated squamous cell carcinoma) and patient age (> or = 55) were found to be significant prognostic factors for a worse OSR. Although survival decreased with increasing T stage, no significant difference was observed. The 5-year OSR of the patients treated with FAR therapy was 53% and was 51% with FAR therapy plus chemotherapy. Compared to FAR therapy alone, adjunctive chemotherapy did not increase OSR of the patients with NPC.

An unusual regressive germinal center, the 'FDC-only lymphoid follicle,' in lymph nodes of organ transplant recipients

Follicular lesions include germinal center (GC) hyperplasia, regressive transformation of GCs, and follicle lysis. The present histologic, electron microscopic, and immunohistochemical study of six autopsy cases after organ transplantation accompanied by the administration of immunosuppressive drugs revealed a peculiar regression of lymph node GCs in two cases, which has not been noted previously. The histologic findings of the regressive GCs were classified into three patterns. In pattern A, the GCs had few or no lymphocytes and were surrounded by a poorly developed mantle zone-like structure. Apoptotic cell death of GC lymphocytes was found in a few GCs, but most GCs lacked tingible body macrophages. In pattern B, the GC lymphocytes and tingible body macrophages were absent, showing crowded follicular dendritic cells (FDCs) in a corpuscular shape. In pattern C, the lymphocytic mantle was absent. The GCs were smaller than those in the other patterns, and the shape was irregular because of disintegration of FDCs. The immunostaining for FDC markers revealed dispersed growth of FDCs. On electron microscopy, the lesions were composed of a dense mass of elliptical and oval cells without prominent cytoplasmic processes, a labyrinthlike structure, and emperipolesis of lymphocytes. The distinct desmosomelike adhesive junctions, specific electron microscopic features of FDCs, were evident. We propose to call these follicular lesions "FDC-only lymphoid follicles." It is speculated that this follicle may be evoked after preceding follicular hyperplasia with a complicated mechanism including increased apoptosis of GC lymphocytes and decreased lymphocyte migration to lymph node GCs caused by immunosuppressive drugs.

[Multicenter prospective survey of prognosis of hypertensive elderly outpatient under antihypertensive treatment--morbidity and mortality of cardiovascular diseases and cancer]

Although calcium-channel blockers and angiotensin-I-converting enzyme inhibitors are often used for treatment of hypertension in the elderly in Japan compared to those in the United States and in European countries, there have been few investigations on the prognosis of the elderly receiving these antihypertensive treatments. The Research Group for "Guidelines on the Treatment of Hypertension in the Elderly" collaborated with the Comprehensive Research Projects on Aging and Health group of the Ministry of Health and Welfare of Japan in performing a 3-year survey on the outcome of 700 hypertensive elderly outpatients (> or = 60 years) receiving treatment of antihypertensive drugs. Antihypertensive drugs including dihydropyridine-type calcium channel blockers, beta blockers, angiotensin-I-converting enzyme inhibitors, diltiazem, diuretics and old-type antihypertensives (hydralazine, budralazine, and centrally acting drugs such as clonidine, methyldopa and guanabenz) were administered to 71.3%, 30.4%, 26.2%, 14.0%, 8.6%, and 6.4% of the 642 elderly patients surveyed for three years, at the time of registration, respectively. Morbidity and mortality rates of total cerebro-cardiovascular diseases, stroke, and heart diseases, were 27.6 and 7.81/1,000 patient-years, 15.1 and 3.6/1,000 patient-years, 10.4 and 4.2/1,000 patient-years, respectively. These results were similar or even better than those of megatrials of antihypertensive treatments for elderly patients in Europe and United States. After adjustment for potential confounding factors, multiple logistic analysis revealed that a past history of ischemic heart disease, use of the old-type antihypertensive drugs, male gender, and diastolic high blood pressure were independent risk factors for the morbidity of cerebro-cardiovascular diseases taking the group of non-cerebro-cardiovascular disease as the reference group. We also identified 22 cases of newly occurred malignancies including 7 fatal cases. However, none of the antihypertensives was significantly related to the occurrence of malignancies. These results lead support to the tendencies in the use of antihypertensive drugs in Japan.

Modified functional hemispherectomy in hemimegalencephaly

We report a case of hemimegalencephaly in a 13-month-old girl successfully treated with modified functional hemispherectomy. Instead of total temporal lobectomy, medial temporal lobectomy with excision of the hippocampus and amygdala was carried out. The central region including the parasagittal tissue was preserved. A few days after the surgery seizures completely ceased. Administration of anticonvulsants was stopped 5 months after the surgery, and she has been seizure-free for 42 months.

A case of Graves' disease associated with autoimmune hepatitis and mixed connective tissue disease

The patient was a woman of forty-eight. Liver dysfunction was pointed out at the age of forty-five. She was admitted to hospital because of her hyperthyroidism. Her palmar skin was wet and her fingers were swollen like sausages. She had a diffuse and elastic hard goiter with a rough surface. The serum levels of free T3 (9.6 pg/mL) and free T4 (3.76 ng/dL) were high and that of TSH (0.11 microU/mL) was low. The activity of TSH-binding inhibitory immunoglobulin (TBII) was 89%. The uptake rate of 123I to the thyroid was 55.1% and the uptake pattern was nearly diffuse. The goiter was proved to contain several nodules by ultrasonography, but aspiration cytology showed no malignant cells. She was diagnosed to have Graves' disease with adenomatous goiter. She also had high ALT (34 IU/L) and gamma-globulin (1.97 g/dL). She had positive antinuclear antibody (speckled type), positive anti-ribosomal nuclear protein antibody, and positive LE cell phenomenon. The liver biopsy revealed mononuclear cell infiltration with fibrosis in the portal area. These data indicated that she also had autoimmune hepatitis (AIH) and mixed connective tissue disease (MCTD). The analysis of human leukocyte antigen (HLA) showed positive A11 which had been reported to relate to Graves' disease, and positive DR4 which had been reported to relate to AIH and MCTD. These results suggested that HLA would determine susceptibility to three distinct autoimmune diseases in this case.

Immunization of bovines with an aspartic proteinase precursor isolated from Boophilus microplus eggs

The capacity of the Boophilus Yolk pro-Cathepsin (BYC) to induce a protective immune response in cattle against Boophilus microplus infestation was tested by vaccination experiments and by inoculation of monoclonal antibody (MAb) against BYC into fully engorged tick females. In immunization experiments the measurement of various biological parameters demonstrated a partial protection against B. microplus. A continuous decrease in the levels of specific antibodies was observed over 11 months when six bovines were maintained in field conditions. The inoculation of the MAb into tick females produced a dose-dependent decrease in oviposition and survival of the ectoparasite compared to the control.

GABAergic mechanisms in the action of general anesthetics

1. The effects of volatile and intravenous anesthetics were studied on evoked field potentials in rat hippocampal CA1 neurons in vitro to determine the role of GABAergic mechanisms in the action of general anesthetics. 2. It was observed that both volatile (halothane, isoflurane, sevoflurane) and intravenous (thiopental, pentobarbital, propofol) anesthetics decreased population spike (PS) amplitudes. 3. Using paired-pulse paradigms, it was revealed that volatile agents enhance paired-pulse facilitation (PPF), and intravenous agents reduce PPF. Use-dependent effects on PS amplitudes were observed following application of the intravenous anesthetics, whereas volatile agents did not show use-dependency. The effects of the intravenous anesthetics were blocked by the GABA(A) receptor antagonist, bicuculline. 4. It is suggested that agent specific actions of general anesthetics are a result of differential effects on GABAergic mechanisms that modulate synaptic transmission.

Regulation of cytosol-nucleus pH gradients by K+/H+ exchange mechanism in the nuclear envelope of neonatal rat astrocytes

In order to study the subcellular heterogeneity of intracellular H+ concentration in reactive astrocytes, the pH in the nucleus and cytosol of cultured astrocytes was measured using a confocal laser scanning microscope (CLSM) and pH indicator dye, 5'(and 6')-carboxyseminaphthofluorescein (carboxy SNAFL-1). The change in intracellular pH was indexed by the fluorescence ratio (F535/F610) at an excitation wavelength of 514.5 nm. The in vitro fluorescence ratio increased as pH decreased. This ratio in the nucleus was significantly lower than that in the cytosol of astrocytes when perfused by HEPES-buffered Hanks' balanced salt solution (HHBSS) at pH 7.4. Acid stimulations of cells (pH 5.0) raised the fluorescence ratio in both nucleus and cytosol. However, the increase in the fluorescence ratio of the nucleus was less than that of cytosol. Treatment with a K+/H+ ionophore, nigericin (20 microM), reversibly nullified this cytosol-nucleus pH gradient. These findings suggest that a buffering mechanism(s) for maintaining of intracellular pH exists between the nucleus and cytosol, and a K+/H+ exchanger may act on the nuclear envelope to eventuate intranuclear pH maintenance in the living cells.

Induction of apoptosis by Smad3 and down-regulation of Smad3 expression in response to TGF-beta in human normal lung epithelial cells

Smad family members are essential intracellular signaling components of the transforming growth factor-beta (TGF-beta) superfamily involved in a range of biological activities. Two highly homologous molecules, Smad2 and Smad3, have so far been identified as receptor-activated Smads for TGF-beta signaling and have become the focus of intensive studies. However, no definite differences in regulation or function have been established between these TGF-beta signaling molecules. In the present study, we show that the expression of Smad3, but not its close relative, Smad2, is down-regulated by TGF-beta mediated signals themselves in human lung epithelial cells. This down-regulation of Smad3 by TGF-beta treatment did not appear to result from shortening of the half-life of Smad3 mRNA. Constitutive expression of Smad3 in the presence of TGF-beta induced apoptotic cell death, with an adverse effect on the cell growth of human lung epithelial cells. Apoptotic cell death could also be induced by forced expression of Smad2 in the presence of TGF-beta, but less efficiently than by that of Smad3. These findings clearly define the distinctions between Smad2 and Smad3 for the first time in that a qualitative difference was observed with regard to the regulation of their expression in response to TGF-beta, while Smad2 and Smad3 appeared to have quantitatively different capabilities regarding the induction of apoptotic cell death in human lung epithelial cells.

[Efficacy of epidural analgesia in minimally invasive direct coronary artery bypass surgery]

Minimally invasive direct coronary artery bypass surgery (MIDCAB), coronary bypass grafting with small thoracotomy using no cardiopulmonary bypass (CPB), became popular recently. To attenuate perioperative stress-response, we used epidural analgesia (EPI) with general anesthesia for MIDCAB operation. In this study, we compared retrospectively 11 cases of MIDCAB managed with EPI [ED (+)], and 14 cases of MIDCAB anesthetized without using EPI [ED (-)], concerning extubation time, ICU stay, hospital stay and perioperative complications. The mean time from cessation of general anesthesia to extubation was significantly shorter in ED (+) patients (0.5 hours) when compared to ED (-) patients (18.2 hours). Mean periods of ICU stay and hospital stay were, also, shorter in ED (+) patients (2.1 days, 30.5 days, respectively) when compared to ED (-) (4.3 days, 45.1 days, respectively) patients. We experienced ventricular tachycardia in three patients of ED (-). No major complication occurred in ED (+) patients. These results suggest that EPI shortened extubation time, ICU and hospital stay for MIDCAB patients.

Detection of antibodies to bovine viral diarrhoea virus (BVDV) and characterization of genomes of BVDV from Brazil

An ELISA for the detection of antibodies to bovine viral diarrhea virus (BVDV) was developed based on antigens derived from a genotype I BVDV strain isolated in Switzerland. Using monoclonal antibodies we showed that this antigen contained the conserved non-structural protein NS3 whereas it essentially lacked the more strain-specific E2 surface glycoprotein. This ELISA has a sensitivity of 97.5% and a specificity of 99.2% as compared to the serum neutralization test (SNT). Preliminary experiments showed that this ELISA reliably detects antibodies to BVDV strains circulating in Brazil. Serum samples obtained from 430 adult cattle on 19 farms of the State of Rio Grande do Sul (Brazil) and one farm from Corrientes (Argentina) were tested for antibodies by means of this ELISA. We found antibodies in 56% +/- 15.1% of the cattle sera tested, which indicates that, in Brazil, the prevalence of infection with BVDV is similar to that found in Europe and the USA. Our sequence analysis of two BVDV isolates showed that BVDV of both genotypes I and II circulate in Brazil.

Cardiovascular change in elderly male breath-hold divers (Ama) and their socio-economical background at Chikura in Japan

The Ama have existed for more than 2000 years in Japan and Korea. They have been diving for seaweed and molluscs. Their traditional way of fishing, with goggles or a mask, but without a wetsuit, is still practised as a result of laws against overfishing. We investigated cardiovascular diving responses, expressed as heart rate (HR) reduction, peripheral vasoconstriction indicated by skin blood flow (SkBF) and mean arterial blood pressure (MAP) during breath-hold face immersion in a group of eight elderly male Ama at Chikura, Japan. Their data were compared to those from three other groups: a) elderly non-divers; b) young divers and c) young non-divers. Our previous studies have shown that young divers show a more pronounced bradycardia than young non-divers. The present study of elderly Ama and elderly non-divers was performed to investigate if this difference persists in old age. We found that, in spite of many years of diving experience, HR reduction of the elderly professional divers observed during face immersion did not differ from that of elderly non-divers, but it was much less pronounced than in the two younger groups. We conclude that even if a well-developed diving response at young age has been reduced to the level of non-divers, the Ama are still able to continue their work of diving in old age. Ama that has been a traditionally female occupation, is mostly practised by men at Chikura today. No young have been recruited for this profession. Therefore, the present Ama are senior and the traditional breath-hold diving will probably cease to exist in the near future. The probable reasons for these changes are discussed.

Dynamic viscoelastic properties in torsion of four commercially available resins for crown and bridge

In order to clarify the viscoelastic properties of four commercial resins for crown and bridge, the dynamic shear modulus (G'), Knoop hardness (KHN), filler content, quantity of unreacted substance and thermal expansion were measured. The results were as follows. The G' (37 degrees C) of each material ranged from 2.61-11.1 GPa, and gradually decreased with increasing temperature. KHN (23 degrees C) ranged from 29.4 to 120, and the most significant correlation (0.999) was found between G' and KHN. Of the relationship among G', filler content and unreacted substance, there was a highly significant correlation (0.980) between G' and filler content. The coefficient of linear-thermal expansion (alpha) also ranged from 17.9-65.0 x 10(-6)/degree C (25-60 degrees C), and the correlation (-0.961) between G' and alpha was meaningful. It can be presumed that the temperature dependence of G' is closely connected with the specific volume of each material, together with an increase in temperature.

Effects of aging on the insulin actions for the glucose metabolism and renal function in normotensives and essential hypertensives

It has been suggested that hyperinsulinemia compensating insulin resistance in glucose metabolism may be a pathogenic factor in essential hypertension. On the other hand, age-associated increases in the prevalence of glucose intolerance and hypertension are also well established. The aim of this study is to clarify the influence of aging on insulin sensitivity in glucose metabolism and on renal sodium handling under hyperinsulinemia, which may relate to high blood pressure in insulin-resistant subjects. Fifty-two normotensive subjects and 61 patients with essential hypertension were evaluated in this study. The subjects of these groups were divided into young (<40 years old) and middle-elderly (> or = 40 years old): young normotensives (Y-NT, n = 22); middle-elderly normotensives (ME- NT, n = 30); young hypertensives (Y-HT, n = 9); and middle-elderly hypertensives (ME-HT, n = 52). Using the euglycemic hyperinsulinemic glucose clamp, insulin sensitivity was assessed as M value. Just before the start and the termination of the glucose clamp, creatinine clearance (Ccr) and urinary excretion of sodium (UNaV) were measured. In addition, renal plasma flow assessed as para-aminohippuric acid clearance was also measured at the same time in several subjects; 8 Y-NT, 8 ME-NT, 3 Y-HT, and 10 ME-HT. The M value was significantly lower in ME-NT, Y-HT, and ME-HT, compared to Y-NT, although blood sugar and immunoreactive insulin levels were similar in all four groups. In normotensive subjects, there was a significant, negative correlation between age and M value. However, this correlation was not observed in hypertensive patients. UNaV decreased in ME-NT, Y-HT, and ME-HT, but not in Y-NT under hyperinsulinemia by the glucose clamp, whereas Ccr showed no significant change in any group. In all subjects, the change of UNaV (deltaUNaV) correlated significantly and positively with the M value. Renal plasma flow significantly increased under hyperinsulinemia by the glucose clamp in only Y-HT, but not in the other groups. There was a significant, positive correlation between deltaUNaV and the change of renal plasma flow under hyperinsulinemia by the glucose clamp. These results suggested that both the impairments of the insulin sensitivity and insulin-induced vasodilation at the renal artery with aging may partially contribute to age-related elevation of blood pressure through renal sodium retention by compensating hyperinsulinemia. On the other hand, it seems reasonable to assume that these abnormalities, which can contribute to high blood pressure in essential hypertension, already may exist at lower ages in essential hypertensive patients.

Effects of the angiotensin converting enzyme inhibitor temocapril on insulin sensitivity and its effects on renal sodium handling and the pressor system in essential hypertensive patients

The effects of the angiotensin converting enzyme (ACE) inhibitor temocapril on insulin sensitivity and its effects on renal sodium handling and the pressor system were investigated in essential hypertensive patients (EHT). Seven EHT were hospitalized and underwent a 2-h euglycemic hyperinsulinemic glucose clamp before and after 2 weeks' administration of temocapril (4 mg/day). Insulin sensitivity was calculated using the M value from the infusion rate of glucose with hyperinsulinemia using the glucose clamp method. Renal clearances of sodium, lithium, creatinine, and paraaminohippuric acid were used to calculate fractional proximal and distal tubular reabsorption of sodium (FPR(Na), FDR(Na)) and renal plasma flow (RPF) before and during insulin infusion by the glucose clamp method. Temocapril decreased blood pressure and increased M value significantly. Before temocapril treatment, hyperinsulinemia by the glucose clamp induced significant decreases of urinary excretion of sodium (U(Na) V) and fractional excretion of sodium (FENa). After treatment, these decreases were attenuated, and the change of U(Na) V (deltaU(Na) V) with hyperinsulinemia was significantly higher and deltaFENa showed a higher tendency, compared with before the treatment. FPR(Na) showed no change with hyperinsulinemia before treatment, but significantly decreased after treatment. DeltaFPR(Na) was significantly lower after treatment than that before treatment. FDR(Na) showed an increase with hyperinsulinemia, and deltaFDR(Na) was similar between before and after treatment. RPF showed no change with hyperinsulinemia, and no difference was found in deltaRPF between before and after treatment. Plasma norepinephrine level (PNE) and plasma renin activity (PRA) showed increases, whereas plasma aldosterone concentration (PAC) did not change with hyperinsulinemia. There were no significant differences in deltaPNE, deltaPRA, and deltaPAC between before and after treatment. From these results, it is suggested that in EHT 1) temocapril improves insulin resistance, and 2) although temocapril shows no significant influence on the augmentation of pressor systems by hyperinsulinemia, this agent attenuates the sodium-retaining action of hyperinsulinemia, which may be attributable to suppression of insulin-induced sodium reabsorption at the proximal tubules. These effects may lead to additional beneficial effects in the treatment of essential hypertensives with insulin resistance.

A new aspect of the carotid body function controlling hypoxic ventilatory decline in humans

Ventilatory response to eucapnic sustained mild hypoxia was measured in one patient with unilateral and three patients with bilateral carotid body (CB) resection (defined UR and BR, respectively). The profile of ventilatory response in UR patient was initially augmented then gradually declined (biphasic pattern) as generally seen in normal subjects although the absolute magnitude was substantially low. On the other hand, biphasic pattern was disappeared in all three BRs. Lack of hypoxic ventilatory decline (HVD) in the late period of sustained hypoxia was in marked contrast to that reported in the anaesthetized and CB-denervated animals whose ventilation was severely depressed lower than the pre-hypoxic control level. In view of recent knowledge that the analogous mild hypoxia in normal animals and humans elicits an useful adaptation to economize energy expenditure with maintaining reversible excitability in control of respiration, BR patients were considered to have lost this ability. We conclude that in awake humans the CB not only stimulates ventilation but also controls the degree of subsequent HVD during sustained hypoxia.

Pseudoaneurysm of the superficial femoral artery in Behçet's disease with spontaneous thrombosis followed by CT angiography

A 25-year-old man developed sudden pain and a pulsating mass in the left thigh. A diagnosis of Behçet's disease was made because of four major symptoms. Laboratory data indicated active inflammation. Emergency spiral computed tomographic angiography (CTA) showed an aneurysm of the left superficial femoral artery (SFA). Under steroid therapy, follow-up spiral CTA showed spontaneous occlusion of the aneurysm. In the active phase of arteritis, spiral CTA is useful for the diagnosis of arterial lesions to avoid the arterial puncture of conventional arteriography.

Isolation of an aspartic proteinase precursor from the egg of a hard tick, Boophilus microplus

An aspartic proteinase precursor, herein named BYC (Boophilus Yolk pro-Cathepsin) was isolated from eggs of the hard tick, Boophilus microplus. As judged by electrophoresis on sodium dodecyl sulfate polyacrylamide slab gel (SDS-PAGE), purified BYC presented 2 bands of 54 and 49 kDa, bearing the same NH2-terminal amino acid sequence. By Western blot analysis, BYC was also found in the haemolymph, indicating an extraovarian site of synthesis. Several organs were incubated in culture medium with [35S]methionine, and only the gut and fat body showed synthesis of BYC polypeptides. Protein sequencing of both the NH2-terminal and an internal sequence obtained after cyanogen bromide (CNBr) cleavage of BYC revealed homology with several aspartic proteinase precursors. Incubation at pH 3.5 resulted in autoproteolysis of BYC, which produced the mature form of the enzyme, that displayed pepstatin-sensitive hydrolytic activity against haemoglobin. Western blot analysis using anti-BYC monoclonal antibodies showed proteolytic processing of BYC during embryogenesis and suggested activation of the enzyme during development. A role of BYC in degradation of vitellin, the major yolk protein of tick eggs, is discussed.

Spatially- and temporally-restricted expression of meltrin alpha (ADAM12) and beta (ADAM19) in mouse embryo

The cloning of the full-length cDNA encoding meltrin beta (ADAM19), one of the metalloprotease-disintegrins expressed in mouse myogenic cells, revealed that the meltrin beta gene encodes a membrane protein closely related to meltrin alpha (ADAM12) which participates in myotube formation in vitro. To delineate the functions of meltrin alpha and beta, we examined the expression patterns of their transcripts during embryogenesis. The meltrin alpha gene is activated in condensed mesenchymal cells that give rise to skeletal muscle, bones and visceral organs. Meltrin beta mRNA, in contrast, is markedly expressed in craniofacial and dorsal root ganglia and ventral horns of the spinal cord, where peripheral neuronal cell lineages differentiate. Heart, skeletal muscle, intestine and lung also express meltrin beta mRNA transiently. Although the meltrin alpha and beta transcripts exhibit distinct expression patterns during embryogenesis, both genes are mainly activated in mesenchymal cells that are derived from both mesoderm and ectoderm.