Transsphenoidal-transtuberculum sellae approach for supradiaphragmatic tumours: technical note

The Classic transsphenoidal approach may not afford sufficient exposure for a supradiaphragmatic tumour adjacent to the pituitary stalk. Various transcranial approaches have been utilized to access such a lesion with adequate results. This report describes a less invasive technique, termed "transsphenoidal-transtuberculum sellae approach". This modified transsphenoidal approach requires a bone ablation of the tuberculum sellae, the limbus sphenoidalis, and a portion of the planum sphenoidale, in addition to an opening of the anterior floor of the sella turcica. The dura mater on the tuberculum sellae and the pituitary fossa is sectioned with a bilateral obliteration of the anterior intercavernous sinus. The anterior pituitary gland is not necessarily resected. The optic chiasm, optic nerves, pituitary stalk, and tuber cinereum can be directly observed, making it possible to safely dissect a lesion from these structures. Utilizing this approach, we have removed 14 supradiaphragmatic tumours without complications and dealt with other lesions such as optic nerve injuries or cerebrospinal fluid rhinorrhea, leaving pituitary function intact. The transsphenoidal-transtuberculum sellae approach for accessing small supradiaphragmatic tumours is a useful procedure requiring only a minor modification of the classic transsphenoidal technique.

Glutamate transporter GLT-1 is transiently localized on growing axons of the mouse spinal cord before establishing astrocytic expression

The glutamate transporter GLT-1 is expressed in astrocytes of the mature brain and spinal cord. In the present study, we examined its expression in the developing mouse spinal cord. By in situ hybridization, 35S-labeled antisense oligonucleotide probes for GLT-1 mRNA consistently labeled the mantle zone/gray matter from embryonic day 11 through the adult stage. However, immunohistochemistry with a specific antibody visualized distinct regional and cellular localizations during the time between the fetal and postnatal stages. At fetal stages, GLT-1 immunoreactivity predominated in the marginal zone/white matter, observed as tiny puncta in cross-sections and as thin fibers in longitudinal sections. The GLT-1-immunopositive structures were also labeled for neuron-specific enolase, a glycolytic enzyme specific to postmitotic neurons and endocrine cells. By electron microscopy, GLT-1 immunoreactivity was detected in axons forming frequent enlargements and was focally localized on a small portion of the axolemma, particularly that facing adjacent axons. At early postnatal stages, GLT-1 disappeared from axons in white matter tracts and, instead, appeared in astrocytic processes surrounding various neuronal elements in the gray matter. Therefore, before switching to astrocytic expression, GLT-1 is transiently expressed in neurons and localized in differentiating axons. Together with our previous finding on the localization of glutamate transporter GLAST in radial glial fibers, GLT-1 and GLAST are thus localized during development on distinct directional cellular elements along which young neurons elongate their axons or move their cell bodies, respectively.

Mutation analysis of the Smad2 gene in human colon cancers using genomic DNA and intron primers

In mammals, one of the Mad homologues, Smad2, was reported to be a mediator of TGF-beta signaling, and was found mutated in some cases of colon and lung cancers. To extend the analysis of this gene, we previously investigated the genomic organization of the human Smad2 gene and defined the structure of 12 exons and flanking introns. In this study, we designed 11 sets of intron-based primers to examine the entire coding region of the Smad2 gene. By the PCR-SSCP method using these primers, we screened genomic DNA sequences of colorectal cancers for mutations of the Smad2 gene. Though there was no mutation within all exons of the Smad2 gene, two of 60 sporadic colorectal cancers displayed deletions in the polypyrimidine tract preceding exon 4. Deletions of this region were also detected in colon cancer cell lines, and were clustered within cells exhibiting microsatellite instability. Deletions in the polypyrimidine tract had various effects on pre-mRNA splicing, but had no effect on the splicing of the Smad2 gene in these cases. However, our data support the idea that the polypyrimidine tract in the splicing acceptor site is a target of mutations in mismatch repair-deficient tumors.

Ventilatory control during exercise in normal children

We investigated the relation between age and respiratory control during exercise in 80 children aged 6.4-17.6 y (42 male, age, 11.6 +/- 3.3 y; body weight, 41.3 +/- 14.7 kg; and 38 female, age, 12.6 +/- 2.7 y; body weight, 42.5 +/- 9.3 kg). Exercise tests were performed on a treadmill after a standard symptom-limited Bruce protocol. Data were analyzed separately for boys and girls. At rest and at peak exercise, the ratio of minute ventilation to carbon dioxide production (VE/VCO2), the ratio of effective alveolar ventilation to carbon dioxide production (VA/VCO2), the ratio of pulmonary dead space to tidal volume (Vd/Vt), and arterial PCO2 (PaCO2) were not correlated with age. At the exercise intensity of ventilatory anaerobic threshold, the PaCO2 increased, and the VA/VCO2 decreased, significantly with age, whereas the Vd/Vt was not related to age. Linear regression analysis demonstrated that the slope of the relationship between VE and VCO2 (deltaVE/deltaVCO2) and the slope of the relationship between VA and VCO2 (deltaVA/deltaVCO2) decreased with age. There were no gender differences in the regression slopes and the intercepts of the relationships. Results show that younger children breathe more during exercise to eliminate a given amount of CO2 to keep PaCO2 set point slightly but significantly lower than older children. This age dependence must be considered in investigating ventilatory control during exercise in children.

hSmad5 gene, a human hSmad family member: its full length cDNA, genomic structure, promoter region and mutation analysis in human tumors

hSmad (mothers against decapentaplegic)-related proteins are important messengers within the Transforming Growth Factor-beta1 (TGF-beta1) superfamily signal transduction pathways. To further characterize a member of this family, we obtained a full length cDNA of the human hSmad5 (hSmad5) gene by rapid amplification of cDNA ends (RACE) and then determined the genomic structure of the gene. There are eight exons and two alternative transcripts; the shorter transcript lacks exon 2. We identified the hSmad5 promoter region from a human genomic YAC clone by obtaining the nucleotide sequence extending 1235 base pairs upstream of the 5' end of the cDNA. We found a CpG island consistent with a promoter region, and we demonstrated promoter activity in a 1232 bp fragment located upstream of the transcription initiation site. To investigate the frequency of somatic hSmad5 mutations in human cancers, we designed intron-based primers to examine coding regions by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. Neither homozygous deletions or point mutations were found in 40 primary gastric tumors and 51 cell lines derived from diverse types of human cancer including 20 cell lines resistant to the growth inhibitory effects of TGF-beta1. These results suggest that the hSmad5 gene is not commonly mutated and that other genetic alterations mediate the loss of TGF-beta1 responsiveness in human cancers.

Characterization of the MADH2/Smad2 gene, a human Mad homolog responsible for the transforming growth factor-beta and activin signal transduction pathway

The transforming growth factor beta (TGF-beta) superfamily is a family of multifunctional cytokines that transduce signals via serine/threonine kinase receptors. Recent studies revealed that Mothers against dpp (Mad) in Drosophila and its homologs play important roles in the intracellular signal transduction of the serine/threonine kinase receptors. In mammals, one of the Mad homologs, MADH2 (also termed Smad2), was reported to be a mediator of TGF-beta and activin signaling and was found mutated in some of the colon and lung cancer cases. We describe here the genomic organization of the human MADH2 gene. The gene is composed of 12 exons; 2 exons 1, i.e., exon 1a and 1b, are used separately or in conjunction to form exon 1a-exon 1b-exon 2 alternatively spliced mRNA. The 2 exons 1 are closely located, and the MADH2 mRNAs are transcribed from two promoters in one CpG island. The promoter activity in the 5' upstream sequence was confirmed by the luciferase assay. The 3' end of the mRNA is heterogenous, and we found several polyadenylation signals. Northern blot analysis revealed high expression of the MADH2 mRNA, e.g., in skeletal muscle, heart, and placenta. RT-PCR assay using primers in exons 2 and 4 and direct nucleotide sequencing proved that exon 3 is spliced out in about 10% of MADH2 in human placenta. These data will be valuable for studying the MADH2 function in both normal cells and cancer cells.

A de novo missense mutation of human cardiac Na+ channel exhibiting novel molecular mechanisms of long QT syndrome

Mutations in a human cardiac Na+ channel gene (SCN5A) are responsible for chromosome 3-linked congenital long QT syndrome (LQT3). Here we characterized a de novo missense mutation (R1623Q, S4 segment of domain 4) identified in an infant Japanese girl with a severe form of LQT3. When expressed in oocytes, mutant Na+ channels exhibited only minor abnormalities in channel activation, but in contrast to three previously characterized LQT3 mutations, had significantly delayed macroscopic inactivation. Single channel analysis revealed that R1623Q channels have significantly prolonged open times with bursting behavior, suggesting a novel mechanism of pathophysiology in Na+ channel-linked long QT syndrome.

Long-term results of Yoshino total knee arthroplasties in rheumatoid arthritis

A review was made of 267 Yoshino total knee arthroplasties performed on 184 patients with rheumatoid arthritis between June 1978 and December 1983. The average duration of follow-up was 14.3 years. Of these patients 46.7% died during the follow-up period. The main causes of death were cardiac disease, respiratory disease and renal disease. According to the Japanese Orthopaedic Association (JOA) knee rating system, JOA scores decreased significantly with time after surgery, but remained significantly higher than the preoperative scores. The flexion angle after surgery had decreased compared with the preoperative flexion angle and decreased further 3 years after surgery and later. The cumulative survival rate was 88.6%. This rate was mainly affected by postoperative infection and aseptic loosening of the tibial components.

Response of parathyroid hormone to anaerobic exercise in adolescent female athletes

It has been shown that moderate exercise suppresses parathyroid hormone (PTH) secretion, while strenuous exercise is apt to induce continuous secretion, which has a negative effect on bone mineral densities (BMD). The present study investigated a typical response of PTH to brief exercise. The study group comprised six adolescent female basketball players whose BMD were within normal limits. Maximal anaerobic power by three-step cycling was loaded on each subject. The first blood sample was drawn 30 min prior to testing test, the second was immediately following, the third was 15 min after, and the fourth was 30 min after. The proportional change in plasma volume was -11.5% immediately following (P < 0.05), +2.1% 15 min after, and +5.5% at 30 min after exercise (P < 0.05). The expected value was calculated on the assumption of no effect, except changes in plasma volume, by exercise. The measured values of PTH and calcium (Ca) immediately after exercise were lower than each of the expected values (P < 0.05 for both). At 15 min after, there was no significant difference between expected and measured values of PTH, Ca and magnesium (Mg), respectively. At 30 min after, the measured value of Ca and Mg was higher than each expected value (P < 0.05 for both). It was concluded that PTH secretion is suppressed transiently immediately after maximal anaerobic exercise and is then stimulated during the recovery time in normal BMD subjects.

[Morphological studies on lower margins of nasal aperture in the skull of Hokkaido Japanese]

It is well-known that the lower margins of nasal aperture in the human skull may be classified into the following four types, i.e., Forma anthropina, Forma infantilis, Fossae praenasales and Clivus nasoalveolaris, and that the rates of appearance of these four types differ with races. In the present study we made morphological studies on the lower margins of nasal aperture of 465 Hokkaido Japanese skulls, 463 skulls with symmetrical nasal aperture and 2 skulls with asymmetrical one, and compared the findings with those of all races in the world, especially of the Japanese, Ainu, Moyoro Man, Hamanaka Site Man and Eskimo. Forma anthropina was found in 330 skulls (71.27 +/- 2.10%) among the 463, marking the highest rate. Forma infantilis, found in 74 skulls (15.98 +/- 1.70%) among the 463, marked the second highest rate. Fossae praenasales, found in 42 skulls (9.07 +/- 1.33%) among the 463, marked the third highest rate. These 42 cases of Fossae praenasales were further classified into three types, i.e., sub-Forma infantilis, 17 (40.48%), typical Fossae prenasales, 23 (54.76%) and sub-Clivus nasoalveolaris, 2 (4.76%). Clivus nasoalveolaris, found in 17 skulls (3.67 +/- 0.87%) among the 463, marked the lowest rate. As a whole, the rates of the four types in the Hokkaido Japanese were close to those in the other groups of the Japanese in Kinai and Hokkaido (Ito).

[Studies on the foramen vesalius in the Japanese juvenile and adult skulls]

Foramen Vesalius is known to be an inconstant foramen, which appears in the anteriomedial side of the foramen ovale. The foramen Vesalius is classified into the open type and the closed type. We studied the frequencies and the types of foramen Vesalius in Japanese by examining 20 juvenile skulls from 3 months to 8 years old and 400 adult skulls from 18 to 91 years old. Of the 20 juvenile skulls, 11 skulls (55.00%) had foramen Vesalius. Of the 400 adult skulls, 87 skulls (21.75%) had foramen Vesalius; 69 (21.50%) in 321 male and 18 (22.78%) in 79 female skulls. No remarkable differences were observed in the ratio between the male and the female, and between the left side and the right side. Among the 69 adult male skulls, the foramen Vesalius was bilateral in 52 skulls (75.36%) and unilateral in 17 (24.64%); among the 18 adult female skulls, it was bilateral in 13 (72.22%) and unilateral in 5 (27.78%). The ratio of the closed type was slightly higher than that of the open type in both sexes and in both sides; however, no remarkable differences were observed. The skulls with one foramen Vesalius were most frequent; those with two followed it and those with 3 foramen Vesalius were least frequent. No remarkable differences were observed in the number of foramen Vesalius between the sexes and the sides.

Cardiorespiratory response to exercise in patients with exercise-induced bronchial obstruction

OBJECTIVE

To document the characteristics of the ventilatory response to exercise in patients with exercise-induced bronchial obstruction (EIB).

EXPERIMENTAL DESIGN

Comparative study during the period between December 1993 and March 1994.

SETTING

Ambulatory care in Ohgaki Municipal Hospital.

SUBJECTS AND METHOD

We evaluated 11 children with EIB. Each subject under went symptom-limited cardiopulmonary treadmill exercise testing (Bruce protocol).

RESULTS

Patients with EIB showed a significantly lower peak oxygen consumption (peak VO2) than the control subjects. Three patients with EIB developed relative hypoventilation during incremental exercise: an increase in end-tidal carbon dioxide partial pressure (PETCO2) and a decrease in VE/VCO2 were observed at the end-stage of exercise testing.

CONCLUSIONS

These findings demonstrate that some patients with EIB develop bronchoconstriction during exercise.

Ventricular hypertrophy as a risk factor in ventricular septation for double-inlet left ventricle

BACKGROUND

Ventricular septation is an option for surgical correlation of double-inlet or common-inlet left ventricle. However, the surgical risk factors of ventricular septation remain unknown.

METHODS

Twenty-three patients with double-inlet or common-inlet left ventricle underwent ventricular septation. Preoperative data were compared between the survivors (n = 18) and the nonsurvivors (n = 5) to assess surgical risk factors.

RESULTS

There were two early deaths (9.5%) and three late deaths (14.3%). Nonsurvivors of ventricular septation were significantly older at the time of operation (14.0 +/- 6.0 versus 7.0 +/- 5.4 years; p < 0.05) and had greater left ventricular mass (383% +/- 100% versus 206% +/- 57% of normal predicted value; p < 0.005) and greater left ventricular mass to left ventricular end-diastolic volume ratio (1.84% +/- 1.18% versus 0.77% +/- 0.17%/% of normal predicted value; p < 0.005). Univariate logistic regression analysis also revealed age at operation (p < 0.05) and mass/end-diastolic volume ratio (p < 0.05) as significant risk factors for death after operation. Multivariate regression analysis revealed that age at operation positively influenced increased mass/end-diastolic volume ratio (p < 0.001). These findings indicated that ventricular hypertrophy was one of the risk factors for ventricular septation, which had a tendency to progress with age.

CONCLUSIONS

Early operation before progression of ventricular hypertrophy is recommended in patients with double-inlet or common-inlet left ventricle who have suitable anatomy for the ventricular septation procedure.

Mutation analysis of the transforming growth factor-beta type II receptor in human cell lines resistant to growth inhibition by transforming growth factor-beta

The transforming growth factor-beta (TGF-beta) binds the type II TGF-beta growth factor receptor (RII) to inhibit the growth of most epithelial tissues. Most human colon and gastric cancers with microsatellite instability (MI) have frameshift mutations in polynucleotide repeats within the RII coding region; these mutations truncate the receptor protein and disable the serine/threonine kinase to produce TGF-beta resistance. To further investigate the type, frequency and tissue distribution of RII mutations, we selected 24 human cancer cell lines from various tissues which were previously reported to be resistant to the inhibitory effects of TGF-beta. We developed protocols for non-isotopic SSCP analysis of PCR products from genomic DNA samples, and we tested them for microsatellite instability. PCR-SSCP analysis followed by DNA sequencing identified deletion mutations in the exon 3 poly-adenine tract in three colon tumor cell lines: LS174T and SW48 had a single base deletion and LS411 had a two base deletion. Among the 24 previously unreported cell lines, only these three demonstrated microsatellite instability. These and other recent data indicate that RII mutations are essentially confined to colon and gastric cancers with microsatellite instability. The narrow spectrum of tissues containing RII mutations illustrates the complexity of genetic checkpoints in human carcinogenesis.

Recombinant advanced glycation end product receptor pharmacokinetics in normal and diabetic rats

Vascular dysfunction in patients with diabetes mellitus is related to advanced glycation end product (AGE) formation. We previously showed that AGEs produce an increase in vascular permeability and generated an oxidant stress after binding to the receptor (RAGE) present on endothelium. RAGE, a 35-kDa protein that belongs to the immunoglobulin superfamily, has been cloned from a rat lung cDNA library, and recombinant rat soluble RAGE (rR-RAGE) has been produced in insect cells. The sequence of RAGE is highly conserved between human and rat. We studied the biological effect of rR-RAGE and pharmacokinetics of 125I-rR-RAGE after intravenous or intraperitoneal administration in normal and streptozotocin-induced diabetic rats. rR-RAGE prevented albumin or inulin transfer through a bovine aortic endothelial cell monolayer, restored the hyperpermeability observed in diabetic rats or induced in normal rats by diabetic rat red blood cells, and corrected the reactive oxygen intermediate production after intravenous or intraperitoneal administration. After intravenous injection of 125I-rR-RAGE, the distribution half-life was longer (p < or = 0.01) in diabetic (0.15 and 4.01 hr) than in normal (0.02 and 0.21 hr) rats, as was the case for the elimination half-lives (diabetic, 57.17 hr; normal, 26.02 hr; p < or = 0.01). Distribution volume was higher in diabetic than in normal rats (6.94 and 3.24 liter/kg, respectively; p = 0.049). Our study showed that rR-RAGE was biologically active in vivo and slowly cleared, which suggests it could be considered as a potential therapy.

Vascular reactivity to endothelium-derived relaxing factor in human umbilical artery at term pregnancy

It has been reported that human umbilical artery (HUA) at term pregnancy released endothelium-derived relaxing factor (EDRF), using a superfusion bioassay system. However, other reports showed that endothelium-dependent relaxation was not observed in isometric tension studies using HUA ring with intact endothelium. Thus, we intended to clarify whether vascular smooth muscle of HUA at term is sensitive to EDRF. HUA was obtained after normal vaginal delivery or cesarean section at term. Isometric tension studies were performed in normal Krebs solution, using HUA rings or strips, which were prepared in calcium-free Krebs solution. Sodium nitroprusside (SNP), a nitric oxide (NO) donor drug, relaxed HUA rings precontracted with 0.1 microM 5-hydroxytryptamine (5HT) in a dose-dependent manner (1 nM-10 microM). Histamine, substance P, carbachol, or the calcium ionophore A23187, which are considered to be EDRF-releasing agents, did not relax the HUA rings. By immunohistochemical study, it was confirmed that endothelial cells were present in the luminal surface of the HUA rings after the isometric tension recording. In a co-axial bioassay system involving HUA strips denuded of endothelium and rabbit aorta with intact endothelium, HUA strips precontracted with 0.1 microM 5HT were relaxed in response to 1 microM SNP but not 1 microM carbachol, which released EDRF from the endothelium of rabbit aorta. These findings suggest that HUA at term is sensitive to NO but not EDRF.

Thrombin, thrombomodulin and TAFI in the molecular link between coagulation and fibrinolysis

The thrombin thrombomodulin dependent activation of the plasma protein TAFI (Thrombin Activatable Fibrinolysis Inhibitor) and Subsequent Inhibition of Fibrinolysis by the TAFIa is described. Work to date indicates that TAFIa is a carboxypeptidase B enzyme that suppress fibrinolysis most likely by down regulating the cofactor functions of partially degraded fibrin. The existence of TAFI provides the explanation for the apparent profibrinolytic effect of activated protein C. and implies the existence of an explicit molecular connection between the blood coagulation of fibrinolytic cascades that is expressed through the thrombin thrombomodulin dependent activation of TAFI. Thus, thrombin generation can, in principle, result in the suppression of fibrinolysis.

Random amplified polymorphic DNA (RAPD) analyses for discriminating genotypes of Microcystis cyanobacteria

Random amplified polymorphic DNA (RAPD) analysis was used to discriminate genotypes in five species of Microcystis cyanobacteria. Strains of each group with the identical allozyme genotype (T. Kato et al., Algol. Stud., 1991, 129-140; M. Watanabe, in "Toxic Microcystis," ed. by M.F. Watanabe et al., CRC Press, Tokyo, 1966, pp. 13-34) gave similar RAPD patterns characterizing the respective group. On the other hand, no similarities in RAPD patterns were observed among strains of which allozyme genotypes were different. A good accordance between the RAPD analysis and allozyme divergence indicated a high reliability of both methods for discrimination of the affiliated groups of Microcystis. Several amplified DNA fragments, which were expected to be markers for a particular taxon with identical allozyme genotype, were also observed on the RAPD patterns. Genetic homogeneities of M. novacekii, M. viridis, and M. wesenbergii were shown by RAPD analysis as well as the allozyme genotype. However, significant variations were observed in M. aeruginosa and M. ichthyoblabe in the levels of DNA and proteins (allozymes).

Absence of mutations in the transforming growth factor-beta type II receptor in sporadic lung cancers with microsatellite instability and rare H-ras1 alleles

The transforming growth factor-beta type II receptor (RII) is commonly mutated in colon and gastric cancers with microsatellite instability (MI). We utilized our series of lung cancers with MI and rare alleles of the H-ras1 gene to determine the association between MI and RII mutations and searched the entire RII coding region in 33 lung cancers with MI by polymerase chain reaction-single-strand conformation polymorphism analysis. We found no mutations, and these data support other recent evidence that RII mutations rarely occur except in colon and gastric tumors with MI.