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.

Association of insulin resistance and hyperinsulinemia with disturbed lipid metabolism in patients with essential hypertension

To clarify the association of insulin resistance and hyperinsulinemia with lipid metabolism in patients with essential hypertension (EHT), we used the euglycemic hyperinsulinemic glucose clamp technique (GC) and the 75-g oral glucose tolerance test (OGTT) to compare the characteristics of glucose and lipid metabolism in insulin-resistant patients with essential hypertension (EHT-R) with those in insulin-non-resistant patients with essential hypertension (EHT-N) and normotensive subjects (NT). Twenty-eight NT and 42 EHT whose body mass index (BMI) was less than 28 kg/m2 were studied to eliminate the effects of obesity on insulin sensitivity and lipid metabolism. Insulin sensitivity was evaluated by GC and expressed as metabolic clearance rate of glucose (M value, mg/m2/min). Mean -ISD of the M value in NT (145.0 mg/m2/min) was chosen as the cutoff point for insulin resistance. On the basis of this value, 33.3% of the EHT were EHT-R. There was no significant difference in age or BMI among the three groups. Blood samples were collected before GC to measure levels of total cholesterol (TC), triglyceride (TG), free fatty acid (FFA), and HDL cholesterol (HDL-C). EHT-R had significantly higher levels of fasting blood sugar, fasting immunoreactive insulin, insulin at 120 min (IRI-120), and summation of insulin or blood sugar (BS) during the OGTT, as compared with NT and EHT-N. EHT-R also had significantly higher FFA and TG than the other two groups, while there was no difference in FFA or TG between EHT-N and NT. TC and HDL-C were similar in the three groups. There was either a significant negative correlation, or a trend toward negative correlation, between M value and FFA (r= -0.50, p < 0.05) or TG (r= -0.24, p < 0.1). There were significant positive correlations between IRI-120 and FFA (r=0.35, p< 0.05) or TG (r=0.29, p< 0.05). There was a positive correlation (r= -0.36, p< 0.01) between sigma BS and FFA, while no other significant relation was found between sigma BS and serum lipids. In summary, (i) 33.3% of EHT were found to be insulin resistant, when insulin resistance was defined as M value < 145.0 mg/m2/min, i.e., mean -ISD of the M value of NT; (ii) these EHT-R had higher levels of BS, insulin, FFA, and TG than did NT and EHT-N; (iii) EHT-N showed no difference in the levels of BS, insulin, or lipid, as compared with NT; and (iv) the levels of FFA and of TG correlated negatively with insulin sensitivity and positively with the insulin level during the OGTT. These results suggest that disturbances of glucose and lipid metabolism in EHT may be related to both insulin resistance and compensatory hyperinsulinemia, and that EHT-R may have more risk factors for arteriosclerotic complications than EHT-N.

p27KIP1 in human lung cancers: differential changes in small cell and non-small cell carcinomas

Small cell lung cancers (SCLCs) and non-small cell lung cancers (NSCLCs), two major categories of human lung cancers, have been shown to exhibit considerably different clinicopathological, biological, and molecular genetic characteristics. Inactivation of cyclin-dependent kinase inhibitors is now thought to play an important part in the pathogenesis of this fatal disease. In the present study, we show that in vitro p27KIP1 expression was associated with cell density-dependent growth inhibition in human lung epithelial cells in vitro, whereas in vivo, p27KIP1 expression in lung cells showed an inverse correlation with proliferative activity in the developing and adult normal lungs. Our immunohistochemical examination of 166 lung tumor specimens also revealed a striking difference in p27KIP1 expression between SCLCs and NSCLCs. Of 149 NSCLCs, 107 (72%) showed reduced p27KIP1 expression, with 8 being virtually negative. Furthermore, p27KIP1 expression status was found to be a significant prognostic factor for patient survival in the analysis of the 149 primary, resected NSCLC cases (P = 0.03 by the log-rank test). In contrast, all SCLC specimens thus far examined exhibited significantly increased staining when compared to the corresponding normal lung epithelium. These findings provide additional evidence for the heterogeneity prevalent in human lung cancers and suggest that p27KIP1 might play distinct biological roles in the pathogenesis of the two major histological categories, warranting additional studies to elucidate the functional consequences of such differences.

Molecular cloning of CISH, chromosome assignment to 3p21.3, and analysis of expression in fetal and adult tissues

The murine cytokine inducible SH2-containing (Cis) protein gene (Cish) was recently cloned and shown to have a growth inhibitory function. We have isolated cDNAs coding for its human homologue (CISH) and assigned the gene to 3p21.3 by fluorescence in situ hybridization. Northern blot analysis showed CISH expression in various epithelial tissues including lung and kidney, in which tumors frequently exhibit 3p21.3 deletions.

cDNA cloning of a new member of the FTZ-F1 subfamily from a rainbow trout

We describe here cDNA cloning of an orphan nuclear receptor family member, tFZR1, which has a FTZ-F1 box. The amino acid sequences of the zinc finger domain and the FTZ-F1 box has 92.8% and 100% identity, respectively, with those of zebrafish FTZ-F1. On the other hand, the overall homology between tFZR1 and zebrafish FTZ-F1 is low (33.0%). The results indicate that tFZR1 is a new member of fushitarazu factor 1 (FTZ-F1) subfamily.

Molecular cloning of human TAK1 and its mutational analysis in human lung cancer

In previous reports, we described that DPC4/Smad4 and Smad2 are mutated in a fraction of human lung cancers and suggested possible roles of the downstream mediators of transforming growth factor-beta (TGF-beta)-elicited signals in the pathogenesis of this most common cancer. In the present study, we investigated whether another downstream mediator, human TGF-beta-activated kinase 1 (hTAK1), also is altered in lung cancer. For this purpose, the hTAK1 gene was cloned with the aid of an expression sequence tag database search and cDNA library screening, and hTAK1 was found to be expressed ubiquitously in 2 distinct isoforms regulated in a tissue-specific manner in fetal and adult normal tissues. Interestingly, hTAK1 was assigned to the chromosome region 6q14-21, which is deleted frequently in various human malignancies, including lung cancer. Despite our extensive search for alterations in 39 lung cancer specimens as well as in 16 lung cancer cell lines, somatic mutations of hTAK1 were not identified, indicating that hTAK1 itself is not a frequent target for genetic alterations in lung cancer.

Flexor digitorum profundus avulsion with associated fracture of the distal phalanx

Two unusual cases of flexor digitorum profundus avulsion with an associated fracture of the distal phalanx are reported. In one case the injury consisted of avulsion of a large bone fragment from the distal phalanx and an associated profundus avulsion from the fragment. The other case showed simultaneous shaft fracture of the distal phalanx with avulsion of the profundus tendon, which could not be included in the existing classification of profundus injuries. The latter injury was misdiagnosed initially.

Establishment of human peripheral lung epithelial cell lines (HPL1) retaining differentiated characteristics and responsiveness to epidermal growth factor, hepatocyte growth factor, and transforming growth factor beta1

Novel human epithelial cell lines retaining characteristic features of normal peripheral airway cells were established by transfecting the SV40 large T antigen gene into primary in vitro outgrowths from normal peripheral lung specimens. These lines, designated as HPL1A to HPL1E, showed the polygonal shapes typical of epithelial cells and expressed cytokeratin in abundance. Ultrastructural examination revealed the presence of microvilli, multivesicular bodies, and multilamellar body-like structures that are characteristic of type II pneumocytes, but expression of CC1O transcripts, a highly specific marker for Clara cells, was also observed. Response to transforming growth factor beta, epidermal growth factor (EGF), and hepatocyte growth factor, all of which are thought to be important growth-regulatory molecules for cellular proliferation and developmental processes of peripheral lung, was apparent. In the HPL1A case, markedly altered cell morphology and cytoskeletal organization, potent inhibition of cell growth, and increased expression of an extracellular matrix protein were noted with transforming growth factor beta. Interestingly, both EGF and hepatocyte growth factor stimulated anchorage-dependent growth, whereas only EGF could sustain anchorage-independent proliferation. The HPL1 lines are, to our knowledge, the first series of stable epithelial lines of human peripheral lung to be described. They should be valuable for investigating various aspects of growth regulation and oncogenic processes, including the mechanisms of acquisition of anchorage independence and the interrelationships of genetic changes identified previously in lung cancers. In addition, the HPL1 lines may also prove useful for development of in vitro models for other human lung disorders as well as to elucidate the mechanisms of peripheral lung differentiation.

High plasma immunoreactive leptin level in essential hypertension

Insulin resistance, the most important factor in metabolic syndrome X, has been considered to raise blood pressure. Recently it was reported that insulin resistance was related to an elevated plasma level of leptin, which is an adipocyte-specific ob gene product and which plays a role in food intake suppression, thermogenesis, and energy expenditure through the activation of the hypothalamus. However there are no reports that deal with the relationship of insulin resistance to plasma leptin and blood pressure. To evaluate the role of leptin in essential hypertensives, two groups of subjects who were carefully matched for body mass index (BMI) were studied; 22 normotensives (NT, age: 46.5 +/- 2.6 years, BMI: 23.9 +/- 0.4 kg/m2, male/female: 14/8) and 45 mild-to-moderate essential hypertensives (EHT, age: 51.9 +/- 2.0 years, BMI: 24.5 +/- 0.4 kg/m2, male/female: 21/24). We applied the euglycemic hyperinsulinemic glucose clamp technique to all subjects and insulin sensitivity was evaluated as the M value. EHT showed a significantly lower M value (160.2 +/- 7.4 v 184.3 +/- 7.3 mg/m2/min, P < .05) and higher basal plasma immunoreactive leptin level (7.6 +/- 0.8 v 5.0 +/- 0.8 ng/mL, P < .05) than NT, despite the fact that there was no significant difference between NT and EHT in age, gender, or BMI. The relationship between mean blood pressure and leptin showed a significant positive correlation in all of the subjects (r = 0.31, P < .05), suggesting that leptin may be related to a pathophysiology of essential hypertension.

Successful detection of small acoustic tumors using the stacked derived-band auditory brain stem response amplitude

HYPOTHESIS

The aim of this study was to show that a new auditory brain stem response (ABR) measure, the stacked derived-band ABR amplitude, can detect small acoustic intracanalicular tumors missed by standard ABR measures.

BACKGROUND

Recent studies clearly have shown that standard ABR latency measures have inadequate sensitivity to detection of small intracanalicular acoustic tumors. Consequently, despite its relatively low cost and wide availability, the standard ABR test has been replaced as a diagnostic screening tool by magnetic resonance imaging (MRI) with gadolinium (GdDTPA) contrast. However, screening with MRIs can be problematic because of their high cost, limited availability, and impact on patient comfort. Thus, an ABR method capable of detecting small tumors with good specificity would be an invaluable cost-effective screening tool for reducing the number of patients without tumor imaged.

METHODS

Derived-band ABRs were obtained to 63-dB normal hearing level (nHL) clicks using high-pass noise-masking procedures. The new measure is the wave V amplitude of a stacked ABR constructed by temporally aligning wave V of each derived-band ABR and then summing the time-shifted responses.

RESULTS

In a series of 25 tumor cases, 5 small (< or = 1 cm) intracanalicular tumors, missed by standard ABR latency measures, were detected by this new stacked ABR method. The stacked wave V ABR amplitudes in all five cases were significantly lower than those obtained in a group of normal-hearing individuals without tumors.

CONCLUSIONS

A new ABR measure, the stacked derived-band ABR amplitude, is sensitive to the presence of small intracanalicular tumors in patients and has excellent specificity for the absence of tumors in normal-hearing individuals. This method, in combination with standard ABR measures, appears promising both as a cost-effective approach to reducing the number of patients without tumors imaged and as a method for acoustic tumor screening when MRI scans: 1) are unavailable; 2) are not appropriate because of patient comfort; and 3) need to be justified because of their cost.

[Influence of fluid replacement on serum magnesium concentration and proper magnesium supplementation during general anesthesia]

We have studied the influence of fluid replacement on serum magnesium (Mg2+) concentrations, and studied proper Mg2+ supplementation during general anesthesia. Thirty eight patients undergoing elective surgery randomly received: Mg(2+)-free acetated Ringer solution (Group I, n = 15), acetated Ringer solution containing 0.5 mmol.l-1 of Mg2+ (Group II, n = 6), 1.0 mmol.l-1 of Mg2+ (Group III, n = 7), 2.0 mmol.l-1 of Mg2+ (Group IV, n = 6), or 4.0 mmol.l-1 of Mg2+ (Group V, n = 4). Measurements were made on serum and urine Mg2+ concentrations during anesthesia. In Group I, the serum Mg2+ concentrations decreased in correspondence with the water balance. It is suggested that dilution due to the fluid replacement induced the reduction in serum Mg2+ concentrations since the observed urine Mg2+ concentrations were negligible. In Group II-V, the reduction in serum Mg2+ concentrations was inhibited by Mg2+ supplementation, and the serum Mg2+ concentrations remained unchanged in Group IV. We conclude the Mg2+ supplementation is required during anesthesia when a large amount of fluid is infused.

Uric acid excretion increases during propofol anesthesia

We compared the effect of propofol with that of sevoflurane anesthesia on uric acid (UA) excretion in ASA physical status I and II patients with normal renal function. A propofol group (n = 11) received propofol-nitrous oxide-fentanyl after induction of anesthesia by propofol, while a sevoflurane group (n = 12) received sevoflurane-nitrous oxide-fentanyl after induction of anesthesia by thiamylal. UA, creatinine (Cr), and urea nitrogen concentrations in serum and urine were measured before induction of anesthesia, 1, 2, and 3 h after induction, and on Postoperative Day 1. N-acetyl-beta-D-glucosaminidase, beta2-microglobulin concentrations, and pH in urine were also examined. Plasma clearance of UA (CUA) and Cr (CCr) were calculated. The hourly concentration and excretion of urine UA were significantly higher than those of the sevoflurane group (P < 0.01). Significant correlations were noted between the hourly urine volume and UA concentration (r = 0.58, P < 0.01 for the propofol group; r = 0.51, P < 0.01 for the sevoflurane group). The CUA of the propofol group was significantly higher than that of the sevoflurane group (22.9 +/- 10.6 vs 5.9 +/- 3.4 mL/min, mean +/- SD, P < 0.05). There were no significant differences in other renal variables between the two groups. The present study demonstrated that the UA excretion increased during propofol anesthesia, while it remained stable during sevoflurane anesthesia.

Effects of isoflurane on brain stem blood flow and renal sympathetic nerve activity during induced hypotension

Effects of isoflurane on arterial blood pressure, regional blood flow in the brain stem, and renal sympathetic nerve activity were compared with those during vasodilator-induced hypotension using decerebrate unanesthetized cats. Either prostaglandin E1 (PGE1) or trinitroglycerin (TNG) was used to decrease the mean arterial pressure 30% below the control level. The effects of isoflurane (0.5 MAC for 15 min) were examined in the following three conditions: (1) during PGE1-induced hypotension; (2) during TNG-induced hypotension, and (3) without either vasodilator. Isoflurane decreased the brain stem blood flow in parallel with a systemic blood pressure fall. Electrical activity of the renal sympathetic nerve consisted of a high-amplitude phasic and a low-amplitude tonic discharge. Isoflurane decreased the phasic activity and increased the tonic activity. Although the two vasodilators had a similar effect on systemic blood pressure and renal sympathetic discharge, TNG decreased the brain stem blood flow to a lesser extent than PGE1. However, the effects of isoflurane on all parameters were statistically identical in the three conditions not treated and pretreated with either vasodilator. Also, the blood concentrations of isoflurane did not differ among the three conditions. The present study demonstrates that isoflurane produces similar effects on systemic blood pressure, regional cerebral blood flow and sympathetic efferent discharge during vasodilator-induced hypotension and without any vasodilator.

Monoclonal antibodies against Boophilus microplus and their effects on tick reproductive efficiency

Four monoclonal antibodies (mAbs) against extracts of embryo and gut tissue obtained from fully engorged Boophilus microplus were produced. The mAb BrBml reacted with different instars and tissues, the BrBm2 recognized only antigens present in gut extract and the mAbs BrBm3 and BrBm4 recognized vitellin. The effect of inoculation of these mAbs into fully engorged Boophilus microplus females was also evaluated. The mAbs BrBm1 and BrBm2 caused a decrease in oviposition of approximately 50% and 70%, respectively, and the mAbs BrBm3 and BrBm4 did not affect reproductive efficiency. This assay may be useful as a low-cost test to provide preliminary information on the possible effects of anti-tick antibodies in damaging ticks before attempting cattle vaccination experiments.

Stevastelins, a novel group of immunosuppressants, inhibit dual-specificity protein phosphatases

BACKGROUND

Since the molecular target of the immunosuppressive reagents FK506 and cyclosporin A was revealed to be protein phosphatase PP2B (calcineurin), many researchers have been screening the protein phosphatase inhibitors from microbial metabolites to develop new immunosuppressive reagents. We isolated stevastelin B, which is composed of valine, threonine, serine and 3,5-dihydroxy-2,4-dimethyl stearic acid, and stevastelin A, which is a sulphonylated derivative of stevastelin B. To understand the action mechanism of stevastelins A and B, we synthesized a series of stevastelin derivatives and investigated their structure-activity relationships.

RESULTS

A series of stevastelin derivatives have been systematically synthesized. Stevastelin B inhibited gene expression that is dependent on interleukin-2 (IL-2) or IL-6 promoters in situ, but it had no inhibitory activity against any protein phosphatases in vitro. In contrast, stevastelin A, which is a sulphonylated derivative of stevastelin B, inhibited the phosphatase activity of a dual-specificity phosphatase, VH1-related human protein (VHR), in vitro, but it had no inhibitory activity against gene expression or cell-cycle progression in situ.

CONCLUSIONS

Stevastelin B is a novel immunosuppressant. It inhibited IL-2 or IL-6 dependent gene expression but did not inhibit the phosphatase activity of calcineurin. The structure-activity relationships show that the acidic functional group on the threonine residue and the stearic acid moiety in the stevastelin molecule are important for inhibitory effects on the dephosphorylation activity of VHR in vitro. Stevastelin B might be sulphonylated or phosphorylated after incorporation into the target cell, and then it interacts with protein tyrosine phosphatases and regulates cell-cycle progression.

Follicular dendritic cells (FDC) in retroviral infection: host/pathogen perspectives

Follicular dendritic cells (FDC) are found in the follicles of virtually all secondary lymphoid tissues. In health, these cells trap and retain antigens (Ag) in the form of immune complexes and preserve them for months in their native conformation. FDC thus serve as a long-term repository of extracellular Ag important for induction and maintenance of memory responses. In retroviral infection, FDC trap and retain large numbers of retroviral particles with profound effects on FDC. FDC-trapped retrovirus induces follicular hyperplasia, and conventional Ag trapped prior to infection are lost and new Ag cannot be trapped. Concomitantly, antibody-forming cells (AFC) specific for Ag lost from FDC decrease followed by loss of specific serum antibody (Ab). Eventually, FDC die and follicular lysis occurs. From the pathogen perspective, binding to FDC is remarkably beneficial, bringing together virus and activated target cells that are highly susceptible to infection. Furthermore, FDC permit HIV to infect surrounding cells even in the presence of a vast excess of neutralizing Ab. Preliminary data suggest that FDC maintain virus infectivity-even when the virus cannot replicate. Thus retrovirus infection monopolizes FDC networks, thereby transforming the FDC Ag repository into a highly infectious retroviral reservoir.

Contribution of peripheral chemoreceptor drive in exercise hyperpnea in humans

The peripheral chemoreceptors play a dominant role in the respiratory compensation of lactic acidosis during heavy exercise of humans. Our object was to determine the contribution of peripheral chemoreceptors to exercise hyperpnea during mild to moderate and heavy exercise above the anaerobic threshold. We used a hyperoxic suppression test in six normal male subjects. Inspired gas was abruptly changed without the subject's knowledge from air to pure oxygen for 5 to 6 breaths. The maximal ventilatory depression after O2 breathing was 5.5 +/- 1.7 L/min (BTPS) at mild exercise, and the depression increased with increasing exercise intensity up to 12.8 +/- 4.1 L/min (BTPS). The relative contribution of the peripheral chemoreceptors to ventilation in terms of percentage of the maximal ventilatory depression was maintained, being 20% throughout the entire work ranges studied. The contribution of the peripheral chemoreceptors to total ventilation is hardly altered by lactic acidosis caused by heavy exercise above the anaerobic threshold according to our data. These results suggested that the peripheral chemoreceptors may not be solely responsible for excessive hyperventilation, or residual activities of peripheral chemoreceptors still exist after O2 breathing especially during heavy exercise above the anaerobic threshold.

Sequential observation of micrometastasis formation by bacterial lacZ gene-tagged Lewis lung carcinoma cells

Sequential events in micrometastasis formation including entry into the blood circulation and arrest, extravasation and initial growth in the lung was investigated using bacterial lacZ gene-tagged Lewis lung carcinoma cells (4A1-1). Micrometastases in the lung could thereby be specifically detected at the single cell level by X-Gal staining. After intravenous injection, X-Gal positive tumor cells appeared to extravasate within hours, but most cells then degenerated or died in the alveolar space by 2-3 days postinjection. A decreased BrdU labeling index to a negligible level at 2 days postinjection and reduction of X-Gal positive foci to a basal level (less than 0.1% of injected cells) by 4 days are in line with rapid clearance of tumor cells from the lung. The size and BrdU labeling indices of the persisting X-Gal positive foci, however, started to increase from 4 days postinjection. Type IV collagen immunostaining demonstrated loss of pre-existing basement membranes with growth of micrometastases: When 4A1-1 cells were inoculated subcutaneously, lung micrometastases from resulting tumors were detected as single or small numbers of X-Gal positive cells at 2 weeks postinjection. Progressive development of micrometastasis to macroscopic metastasis was noted by 4-5 weeks postinjection. The results indicate that micrometastasis formation by Lewis lung carcinoma cells involves a sequence of events starting with rapid extravasation after arrest in the lung within 1 day, followed by death of most cells at 2-3 days and subsequent new growth and expansion of persisting tumor cells from 4 days postinjection.

Reconstitution of bacteriorhodopsin from a mixture of a proteinase V8 fragment and two synthetic peptides

The peptide and retinal mixture of bacteriorhodopsin, composed of two synthetic peptides corresponding to helices F (160-197) and G (202-237) and a proteinase V8-derived fragment V1 (1-166), generated the characteristic features of bacteriorhodopsin with absorbance maximum at 550 nm and fluorescence quenching as in two synthetic peptides corresponded to helix A (sequence 7-31) and B (41-65) and a chymotryptic fragment (72-248). The recovery of reconstitution estimated from the absorption and the fluorescence quenching of these mixture was 16-19% and 25-32% of the native purple membrane, respectively, whereas mixtures lacking any one of the peptides exhibited no absorption recovery Circular dichroism of each peptide fragment showed complete formation of alpha-helical structure in a membrane-mimetic medium of sodium dodecyl sulfate. These results indicate that the specific interactions or mutual recognitions between alpha-helices in lipid bilayers are essential for correct bundling of the seven helices and formation of the retinal binding pocket.

Vascularized fibular grafts for the reconstruction of segmental tibial bone defects

Free vascularized fibular grafts were employed in seven patients with large tibial defects following trauma or resection of tumour. All patients were followed for more than 5 years. Tibial union and excellent functional results were achieved in all seven patients. Free vascularized fibular transfer seems to be an effective method of treatment for massive segmental bone defects.

[Treatment of elderly patients with hypertension--complications and current drug therapy]

To investigate current drug therapy for elderly hypertensive patients, we performed a case-card study at Sapporo Medical University and its branch hospitals. The case-card was designed to show prescriptions given for hypertension, complications, and blood pressure. In the 2897 valid cases, calcium antagonists were prescribed in 76.3%, followed by beta-blockers (31.4%), angiotensin-converting enzyme inhibitors (ACE-I) (25.1%) and natriuretic diuretics (18.1%). When the patients were divided into an elderly group (> or = 65 y.o., n = 1475), beta-blockers and ACE-I were found to be more frequently used in the non-elderly group, and diuretics were more frequently prescribed in the elderly group. Calcium antagonists were the most frequently used drugs, irrespective of age. As monotherapy drugs, calcium antagonists were chosen most frequently in both groups. Diuretics were the second most frequently used drug in the elderly group, but beta-blockers occupied that position in the younger group and these patients as a whole. In the elderly group, the manner of prescription was analyzed according to major complications. In patients with ischemic heart disease, beta-blockers and diuretics were used more frequently than in patients without that condition. Diuretics were prescribed more frequently in patients with renal dysfunction. Calcium antagonists and ACE-I were used more frequently in the patients with diabetes mellitus. The same differences were found in the non-elderly patients with those complications. However, among patients with stroke, calcium antagonists were more frequently used in the elderly group and ACE-I were performed in the younger patients. In conclusion, calcium antagonists were used very often regardless of age, and the other drugs were used according to age-dependent differences in pathophysiologic mechanism.

Auditory system plasticity in children after long periods of complete deafness

Deaf children fitted with a cochlear implant provide a unique opportunity to examine the effects of auditory deprivation on the maturation of the human auditory system. We compared cortical evoked potentials recorded in implanted and normal-hearing children and found that age-dependent latency changes for the P1 component, fitted to a decaying exponential curve, showed the same rate of maturation. For implanted children, however, maturational delays for P1 latency approximated the period of auditory deprivation prior to implantation. This indicates the auditory system does not mature without stimulation. Nonetheless, the auditory system retains its plasticity during the period of deafness since the re-introduction of stimulation by the cochlear implant resumes the normal maturational sequence.

Somatic in vivo alterations of the JV18-1 gene at 18q21 in human lung cancers

The chromosome region 18q21 is frequently deleted in lung cancers. Recent identification of JV18-1 at this locus led us to examine whether or not it might also be altered in lung cancers, as is the case for the closely related DPC4 tumor suppressor gene. A missense somatic mutation and a 9-bp in-frame deletion were detected in the highly conserved region of JV18-1 among 57 lung cancer specimens taken directly from patients. The total alterations in JV18-1 and DPC4, however, are not sufficient to account for all 18q21 deletions in lung cancers. These findings suggest that although JV18-1 and DPC4 may play roles in a limited fraction of lung cancers, another tumor suppressor gene may also exist in this chromosome region.

Molecular analysis of the FHIT gene at 3p14.2 in lung cancer cell lines

Chromosome 3p is frequently deleted in various cancers including examples in the lung. A novel gene, termed FHIT, was recently isolated from the fragile site at 3p14.2, with aberrant transcripts being reported in lung cancer tumor specimens. To avoid overlooking tumor-specific altered transcripts due to contaminating normal cells in primary tumors, FHIT alterations were examined in 41 lung cancer cell lines in the present study. Lack of detectable expression or exclusive expression of aberrantly spliced transcripts, often accompanied by intragenic homozygous deletions, were observed in 7 of 24 non-small cell lung cancers (29%) but in 0 of 17 small cell lung cancers (0%). Extensive reverse transcription-PCR-single-strand conformation polymorphism analysis revealed polymorphisms and alternative splicing but failed to identify point mutations. These results suggest distinct mechanisms for FHIT alterations in lung tumorigenesis and that further studies of this interesting gene are warranted.

Contribution of Thy-1-CD4+ T cells to the disorganization of lymphoid follicles in retrovirus-induced immunodeficiency syndrome, MAIDS

The destruction of the lymphoid follicle (LF) and of the follicular dendritic cell network in the secondary lymphoid organs are major pathological features in murine acquired immunodeficiency syndrome (MAIDS). These pathological changes are associated with functional deficiency of lymphocytes. However, the mechanisms involved have not been established. In MAIDS-susceptible C57BL/6 (B6) mice, the destruction of the LF occurred as early as 2-3 weeks after the infection by LP-BM5 murine leukemia virus (MuLV) and was accompanied by the intrafollicular infiltration of T cells of an unusual phenotype, Thy-1-CD4+. B6 mice, which Thy-1+ T cells had been depleted by the repeated inoculation with monoclonal antibody to Thy-1 antigen, developed LF destruction after infection similar to the control B6 mice. The LP-BM5 MuLV-infected C57BL/6-nu/nu (B6-nu/nu) mice, otherwise resistant to MAIDS induction, also developed these abnormalities following the adoptive transfer of highly purified Thy-1-CD4+ T cells obtained from MAIDS mice. Thus, the production of Thy-1-CD4+ T cells and their infiltration into LF are thought to be involved in triggering the LF destruction. However, the cytolysis of follicular components by activated CD8+ T cells or by LP-BM5 MuLV itself was a less likely mechanism as MAIDS developed in B6 mice depleted of CD8+ T cell. A/J mice, which are resistant to viral infection in the presence of CD8+ T cells, also developed MAIDS and LF destruction after the depletion of CD8+ T cells. Furthermore, no follicular destruction was observed in infected B6-nu/nu mice even though they are highly sensitive to LP-BM5 MuLV.

Maturation of human cortical auditory function: differences between normal-hearing children and children with cochlear implants

OBJECTIVE

We investigated maturation of cortical auditory function in normal-hearing children and in children who receive stimulation of their auditory system through a cochlear implant.

DESIGN

As a measure of cortical auditory function, auditory evoked responses (AERs) were recorded from normal-hearing children and adults as well as from children and adults fitted with a cochlear implant. Morphological and latency changes for evoked responses recorded at electrode Cz are reported.

RESULTS

For normal-hearing children, there is a gradual evolution of AER features that extends through adolescence, with P1 latency becoming adult-like in the late teens. Latency changes for P1 occur at the same rate for implanted children, but the overall maturation sequence is delayed. By extrapolation from the existing data, the age at which P1 latency becomes adult-like is delayed by approximately 5 yr for the implanted population. Other typical features of the AER, namely N1 and P2, are either delayed in developing or absent in the implanted children.

CONCLUSIONS

These preliminary findings suggest both similarities and differences in cortical auditory maturation for normal-hearing and implanted children. For implanted children, the 5 yr delay for maturation of P1 latency roughly corresponds to the average 4.5 yr interval between the onset of deafness and the time of implantation. These findings suggest that during the period of deafness, maturation of cortical auditory function does not progress. However, some, if not all, maturational processes resume after stimulation is reintroduced.

[A case of cystic hemangioblastoma of the medulla oblongata]

Cystic hemangioblastoma of the brain stem is an extremely rare clinical entity. Only eight cases have been reported in the literature. This is a report of a case of successful extirpation of a cystic hemangioblastoma of the medulla oblongata. A 47-year-old man was admitted to our clinic with the complaint of progressive numbness on his left upper limb since January 1995. Neurological examination revealed numbness and decreased vibration sensation on his left upper limb. MRI showed a cystic 1.5 x 2.0 cm lesion on the medulla oblongata, and with administration of Gd-DTPA, a small mass lesion on the dorsolateral side of the medulla oblongata. Left vertebral angiogram revealed a tumor fed directly from the left vertebral artery. An operation was performed using a suboccipital approach. The dorsal surface of the medulla was swollen edematously, suggesting the site of a cyst, which emptied by means of opening the wall. The reddish tumor was embedded on the left dorsolateral surface of the medulla oblongate. A total extirpation of the tumor was carried out under microscopic procedure. Histologically, the tumor was diagnosed as a hemangioblastoma. The patient was free from his distressing numbness immediately after the operation, and discharged without neurological deficit.

Retinal melatonin is not involved in corneal mitotic rhythms in the Japanese quail: effects of formoguanamine hydrochloride and eye-lid suture

Relation between retinal melatonin and corneal mitotic rhythms in the Japanese quail was investigated in experiments manipulating the ocular physiology by treatments with formoguanamine hydrochloride (FG) and eye-lid suture. In experiment 1, we investigated the effects of FG, which is known to induce photoreceptor degeneration, on retinal melatonin and corneal mitotic rhythms. FG-treatment completely abolished the retinal melatonin rhythms in both LD 12:12 and constant darkness (DD), but the corneal mitotic rhythm was maintained with high mitotic rate in darkness under a LD cycle and subjective night under DD. The result suggests that 1) the photoreceptor cells in the retina are the site for melatonin production and/or for the oscillator which drives the circadian rhythm in retinal melatonin, and 2) melatonin is not involved in generation of the corneal mitotic rhythm. In experiment 2, we investigated the effects of eye-lid suture, which is known to induce eye enlargement and bulgy cornea, on the retinal melatonin and corneal mitotic rhythms. Eye-lid suture abolished the corneal mitotic rhythm in both LD and DD, with a high mitotic rate being maintained throughout 24 hr. But retinal melatonin maintained its rhythm with high levels in darkness under a LD cycle and in subjective night under DD. The result suggests that 1) bulgy cornea in the sutured eye was induced by the increase in mitotic rate in the light period, and 2) disappearance of the corneal mitotic rhythm does not have a relation to retinal melatonin. These results suggest that retinal melatonin is not involved in generation of the corneal mitotic rhythm and that there are two circadian clock systems in the eye.

Effect of prior O2 breathing on ventilatory response to sustained isocapnic hypoxia in adult humans

Sixteen healthy volunteers breathed 100% O2 or room air for 10 min in random order, then their ventilatory response to sustained normocapnic hypoxia (80% arterial O2 saturation, as measured with a pulse oximeter) was studied for 20 min. In addition, to detect agents possibly responsible for the respiratory changes, blood plasma of 10 of the 16 subjects was chemically analyzed. 1) Preliminary O2 breathing uniformly and substantially augmented hypoxic ventilatory responses. 2) However, the profile of ventilatory response in terms of relative magnitude, i.e., biphasic hypoxic ventilatory depression, remained nearly unchanged. 3) Augmented ventilatory increment by prior O2 breathing was significantly correlated with increment in the plasma glutamine level. We conclude that preliminary O2 administration enhances hypoxic ventilatory response without affecting the biphasic response pattern and speculate that the excitatory amino acid neurotransmitter glutamate, possibly derived from augmented glutamine, may, at least in part, play a role in this ventilatory enhancement.

Variable effects of click polarity on auditory brain-stem response latencies: analyses of narrow-band ABRs suggest possible explanations

The auditory brain-stem responses (ABRs) to rarefaction and condensation clicks were obtained for 12 normal-hearing subjects in quiet, and high-pass masking at 8, 4, 2, 1, and 0.5 kHz. Derived narrow-band wave V latency differences were analyzed with respect to (1) stimulus polarity, (2) absolute differences irrespective of polarity. The analyses revealed no significant stimulus polarity effects on latency for the derived bands. Absolute latency differences regardless of polarity tended to be greater for those derived bands having lower characteristic frequencies (CFs). However, these differences were smaller than the expected half-period of the theoretical CF. Further analyses in three additional subjects using repeated runs of the same polarity indicate that this increase in absolute latency difference with lower derived band CF does not reflect a simple half-period change owing to polarity, but rather to the increase variability in measuring the peak latency of the lower CF derived bands. The variability is consistent with variability of eighth nerve PST histograms behavior observed in animal work [Kiang et al., "Discharge patterns of single fibers in the cat's auditory nerve," Research Monograph No. 35 (MIT, Cambridge, MA, 1965)]. Thus claimed polarity effects observed in other ABR work using absolute values may have been affected by this variability. It appears from these current data that half-period latency shifts of wave V owing to stimulus polarity differences are not observed in derived bands responses initiated from frequency specific regions of the cochlea.

Structural determination of stevastelins, novel depsipeptides from Penicillium sp

Structures of novel immunosuppressants, stevastelin A, B and B3(1) were determined by their spectroscopic and chemical studies. Three stevastelins were shown to be cyclic depsipeptides composed of a fatty acid and three amino acid moieties. The sequence of these moieties was determined to be as 3,5-dihydroxy-2,4-dimethylstearylvalylthreonyl (or O-sulfonylthreonyl in stevastelin A)-O-acetylserine. Cyclic structures were shown to be formed by ester linkages between the carboxylic group of the O-acetylserine moiety and the 5-hydroxy group of the fatty acid moiety in stevastelin A and B, and the 3-hydroxy group of the fatty acid moiety in stevastelin B3.

Absolute structural determination of stevastelin B

Stevastelin B, obtained from a culture of a Penicillium sp. NK374186, is a novel depsipeptide containing three amino acids and 3,5-dihydroxy-2,4-dimethylstearic acid. The stereochemistry of the three amino acids was determined by HPLC analysis, and the relative configuration of the 3,5-dihydroxy-2,4-dimethylstearic acid was elucidated by chemical conversion and NMR analysis. The absolute stereochemistry of stevastelin B was determined by synthetic methods.

Role of a signal transduction pathway which controls disassembly of microfilament bundles and suppression of high-molecular-weight tropomyosin expression in oncogenic transformation of NRK cells

Role of disassembly of microfilament bundles and suppression of high-molecular-weight tropomyosin (TM) expression in growth factor- and various oncogene-induced transformation was studied by using NRK cells and its transformation-deficient mutants. In NRK cells which show a transformed phenotype by treatment with EGF and TGF-beta, cellular stress fibers became dissociated by EGF or EGF and TGF-beta combination, whereas TGF-beta alone caused thicker appearance of stress fibers. Accompanying these changes, the expression of TM isoforms 1 and 2 was suppressed by treatment with EGF or EGF and TGF-beta, but elevated by TGF-beta with similar time courses. On the other hand, the transformation-deficient mutant cell lines, 39-1 and 39-3, did not show the transformed phenotypes by treatment with EGF and TGF-beta. Neither EGF nor EGF and TGF-beta combination affected cellular stress fibers and expression of TM isoforms 1 and 2 in both mutant lines. The relationship between the formation of stress fibers and the expression of TM isoforms was consistent in NRK cells, the mutant lines and their various oncogene-expressing sublines under various culture conditions. NRK cells overexpressing exogenous mouse TM isoform 2 showed markedly decreased susceptibility to EGF-induced dissociation of stress fibers and decreased anchorage-independent growth potential in the presence of EGF and TGF-beta. These results indicate that the transformation-deficient NRK mutant lines, 39-1 and 39-3 have defects in an EGF signal transduction pathway which induces suppression of high-molecular-weight TM expression and disassembly of microfilament bundles and suggested that the activation of the pathway is important for morphological transformation and oncogenic growth in growth factors- and various oncogene-induced transformation of NRK cells.

Effects of hyperinsulinaemia on renal function and the pressor system in insulin-resistant obese adolescents

1. In the present study, using the euglycaemic hyperinsulinaemic glucose clamp technique, we investigated the effects of hyperinsulinaemia on sodium-water metabolism and the pressor system in obesity, both of which have been reported to be closely associated with insulin resistance and/or hyperinsulinaemia. 2. Sixteen obese young subjects and 24 non-obese young subjects who were all normotensives, participated in this study. The 2 h euglycaemic hyperinsulinaemic glucose clamp was performed in a fasting state. The mean glucose infusion rate needed to maintain a fasting blood sugar level (FBS) during the last 30 min of the clamp was used as an indicator of insulin sensitivity (M-value). Before and after the clamp, the following parameters were measured: creatinine clearance (Ccr); urinary excretion of sodium (UNaV); fractional excretion of sodium (FENa); plasma renin activity (PRA); plasma aldosterone concentration (PAC) and plasma noradrenaline concentration (PNA). 3. The M-value was significantly lower in obese subjects compared with non-obese subjects, although FBS and fasting immunoreactive insulin levels were similar in both groups. UNaV and FENa fell only in obese subjects during the clamp, while Ccr showed no significant change in either group. PNA and PRA increased significantly and PAC tended to increase in both groups. 4. These results suggest that obese subjects have insulin resistance with respect to glucose metabolism, but that urinary sodium excretion and the pressor system remain insulin-sensitive; the sensitivity of the sodium retaining action to hyperinsulinaemia was actually higher in obese subjects than in non-obese subjects. Therefore, if compensatory endogenous hyperinsulinaemia was raised by insulin resistance, these two factors may lead to chronic sodium retention and pressor system stimulation and, in turn, to hypertension in obesity.

Functional bovine immunoglobulins in Boophilus microplus hemolymph

The aim of the present work was to quantify the passage of bovine immunoglobulins into the hemolymph of the tick Boophilus microplus during the feeding process and to determine their antibody activity. The knowledge is of paramount importance when vector control or blocking of disease transmission is attempted by vaccination of cattle. Approximately 2% of bovine immunoglobulin present in the serum as determined by competitive ELISA was demonstrated in hemolymph of B. microplus and antibody activity against an antigen of B. microplus in the hemolymph of ticks fed on bovine immunized with the antigen purified from tick eggs was detected by Western blot assay. The antibody reactivity detected against the B. microplus antigen showed that functional antibodies are present in the hemolymph of fully engorged ticks for at least 48 h after completing the parasitic life cycle.

Decreased bone mineral density associated with early menopause progresses for at least ten years: cross-sectional comparisons between early and normal menopausal women

To establish whether early onset of menopause carries an increased risk of osteoporosis, we compared the bone mineral density (BMD) of the second to fourth lumbar vertebrae (L2-4) between 18 women who had menopause before 43 years of age (early menopause group) and 19 women who had menopause after reaching 43 years of age (normal menopause group). Serum levels of calcium, phosphorus, calcitonin, intact parathyroid hormone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E2), and alkaline phosphatase activity were measured, and urine samples were analyzed to derive calcium/creatinine, hydroxyproline/creatinine, pyridinoline/creatinine, and deoxypyridinoline/creatinine (D-Pyr/Cr) ratios. Mean BMD was significantly lower in the early menopause group than in the normal menopause group, and individual BMD values in about half of the subjects in the former group were below the fracture threshold for Japanese women. Serum concentrations of LH, FSH, and E2 were slightly, but not significantly, lower in the early menopause group than in the normal menopause group. The D-Pyr/Cr ratio was significantly higher in the early menopause group than in the normal menopause group. There was no correlation between L2-4 BMD and age or the number of years after menopause in the normal menopause group, but both age and the number of years after menopause were negatively correlated with L2-4 BMD in the early menopause group. These results indicate that BMD in women who have early menopause continues to decline for up to 10 years, and that menopause and aging increase the risk of osteoporosis.

Changes in taste responsiveness in patients with anorexia nervosa during behavior therapy

We evaluated the changes in taste responsiveness of anorexia nervosa (AN) patients during behavior therapy. Taste responsiveness of AN patients was lower at admission when compared to controls but it improved significantly over the course of treatment (p < 0.01). Taste responsiveness improved prior to increase in body weight. No significant correlation was noted between weight gain and improvement in taste responsiveness. The period required to reach a food intake of 1600 Kcal/day and the duration of hospitalization were highly correlated (r = 0.72, p < 0.05). Those who reached 1600 Kcal/day earlier showed more rapid improvements in taste responsiveness. These results suggest that decreased taste responsiveness in AN patients can rapidly improve and such early improvement may result in better progression of treatment.

Differentiation of classical swine fever virus from ruminant pestiviruses by reverse transcription and polymerase chain reaction (RT-PCR)

A reverse transcriptase-polymerase chain reaction (RT-PCR) assay was designed to allow the differentiation of pestiviruses by the expected size of the amplified fragments. One oligonucleotide primer, conserved amongst pestiviruses, and two others specific for either classical swine fever virus (CSFV) or bovine viral diarrhea virus (BVDV), were designed from the 5' non-coding region of the genome. CSFV infected cultures (10 strains) amplified a fragment of an expected size of 200 bp; BVDV cultures (23 strains) or border disease virus (BDV) (2 strains) amplified a fragment of an expected size of 260 bp. The specificity of the amplified fragments was confirmed by restriction enzyme analysis. The threshold of sensitivity was 100 TCID50 for CSFV and 1 TCID50 for BVDV. The RT-PCR described here provides a rapid and sensitive diagnostic tool for the detection and differentiation of CSFV from ruminant pestiviruses.

Open reduction of chronic lunate and perilunate dislocations

Four patients with chronic lunate and perilunate dislocations were treated by open reduction and internal fixation. The interval between injury and operation was 7, 8, 14 and 18 weeks, respectively. Both palmar and dorsal surgical approaches were needed to reduce the old dislocation in all cases. A case of dorsal trans-scaphoid perilunate dislocation showed concurrent partial disruption of the scapholunate ligament. Transient vascular compromise of either the lunate or the proximal scaphoid fragment was noted in three patients. Despite the delay in treatment, all patients had satisfactory outcomes.

Effects of hyperinsulinemia under the euglycemic condition on calcium and phosphate metabolism in non-obese normotensive subjects

The effect of acute insulin infusion on the metabolism of calcium (Ca) and phosphate (P) was examined in 17 healthy subjects. They were hospitalized and kept on a constant diet for 5 days, and an euglycemic hyperinsulinemic glucose clamp was applied. Synthetic human insulin was infused at the rate of 40 mU/m2/min for 2 hr, and glucose was also infused to maintain basal glucose levels of each subject. The control study was performed in 8 of the 17 subjects, into whom 10% xylitol was infused for 2 hr at the rate of 100 ml/hr. The plasma insulin concentrations were 7.94 +/- 0.35 and 62.3 +/- 14.3 mU/liter before and after the glucose clamp technique, but serum free Ca ion was increased significantly (p < 0.05), and serum P and serum parathyroid hormone (PTH) were decreased significantly (p < 0.001). Creatinine clearance did not change during the glucose clamp technique. Urinary excretion of Ca (UCaV) was significantly higher after the glucose clamp than the control study. Fractional excretion of Ca (FECa) was increased significantly (p < 0.05), and urinary excretion of P (UPV) and fractional excretion of P (FEP) were decreased significantly (p < 0.05) under the hyperinsulinemic condition. The results suggested that, under the conditions of euglycemic hyperinsulinemia by glucose clamp technique, insulin increased the serum free Ca ion, and as a result, PTH was suppressed. Decreased PTH might induce calciuresis and enhance tubular P reabsorption under hyperinsulinemia. Insulin increased serum free Ca ion might relate to the vasodilating action of insulin by its decrease of intracellular free Ca ion in vascular smooth muscle.

Influence of aging on insulin sensitivity in essential hypertensives and normotensives

Insulin resistance and hyperinsulinemia have been linked with essential hypertension. Age-associated increases in glucose intolerance and hypertension are also well established. To clarify the influence of aging on the insulin sensitivity, euglycemic hyperinsulinemic glucose clamp technique was carried out in 41 normotensive subjects and 42 patients with essential hypertension. The subjects of these groups were divided into two subgroups: young (< 40 years old) and middle-elderly (> or = 40 years old). Insulin sensitivity was assessed as M-value, the rate at which glucose must be infused to maintain a basal blood glucose level. In normotensive subjects, the young subgroup had a significantly higher M-value than did the middle-elderly subgroup. There was a significant negative correlation between age and M-value in normotensive subjects. On the other hand, there was no significant difference in M-value between the young and middle-elderly subgroups in the patients with essential hypertension. The age did not correlate with M-value in the hypertensive group. The normotensive subjects showed a significantly lower M-value than the hypertensive patients in the young group, but not in the middle-elderly group. These results indicate that 1) insulin sensitivity declines with age in normotensive subjects and that 2) insulin sensitivity is already diminished in the early stage of hypertension, and no further decrease in insulin sensitivity occurs with aging in essential hypertensive patients.