Long-term hemodynamic results of percutaneous transvenous mitral commissurotomy in rheumatic mitral stenosis with pliable, non-calcified valves

Percutaneous transvenous mitral commissurotomy (PTMC) for severe, symptomatic mitral stenosis was successfully performed in 47 of 50 patients with pliable, non-calcified valves. The procedure resulted in immediate hemodynamic and sustained clinical improvements in all patients. Repeat cardiac catheterization was performed in 22 patients at a mean follow-up period of 15 months (range 12 to 29). The patients were similar to the other 25 patients in regard to gender, age, clinical and hemodynamic characteristics. There were 4 males and 18 females with a mean age of 37 years (range 20 to 61). Immediately after PTMC, there were significant increases in the mitral valve area (1.0 +/- 0.2 to 2.4 +/- .9cm2, p less than 0.001) and cardiac index (3.1 +/- 0.7 to 3.3 +/- 0.7 l/min/m2, p less than 0.05) and significant (p less than 0.001) decreases in the left atrial pressure (25.7 +/- 6.4 to 13.2 +/- 3.9 mmHg), the mitral valve gradient (15.7 +/- 5.7 to 3.9 +/- 1.4 mmHg), mean pulmonary arterial pressure (41.5 +/- 10.7 to 29.2 +/- 10.9 mmHg) and the pulmonary vascular resistance (4.2 +/ 3.4 to 3.5 +/- 2.9 Wood unit). At follow-up study, the mitral valve area (2.2 +/- 0.7 cm2) and the left atrial pressure (12.6 +/- 3.7 mmHg) remained unchanged. There were further decreases in the mean pulmonary arterial pressure (22.4 +/- 5.9 mmHg, p less than 0.05) and the pulmonary vascular resistance (2.0 +/- 1.5 Wood unit, p less than 0.05). There were significant (p less than 0.05) increases in the mitral valve gradient (6.6 +/- 2.5 mmHg) and the cardiac output (3.6 +/- 0.7 l/min/m2).(ABSTRACT TRUNCATED AT 250 WORDS)

Catecholaminergic innervation of the hippocampus in the cynomolgus monkey

We studied the immunocytochemical distribution of catecholaminergic fibers in the hippocampal formation from two cynomolgus monkeys by using phenylethanolamine-N-methyltransferase, dopamine-beta-hydroxylase, and tyrosine-hydroxylase antibodies. There were no phenylethanolamine-N-methyltransferase immunoreactive fibers suggesting the lack of epinephrine containing fibers. In order to compare the distributions of tyrosine-hydroxylase and dopamine-beta-hydroxylase immunoreactive fibers, we counted fibers in four hippocampal regions, the dentate gyrus, CA3, CA1, and the subiculum at three different rostrocaudal levels. The distributions of dopamine-beta-hydroxylase and tyrosine-hydroxylase immunoreactive fibers were overlapping but clearly different, suggesting that the hippocampus receives both noradrenergic and dopaminergic inputs in primates. Dopamine-beta-hydroxylase-immunoreactive fibers were present in moderate density and roughly evenly distributed throughout the hippocampus. Tyrosine-hydroxylase immunoreactive fibers were found in high density in the dentate gyrus, in the stratum lacunosum-moleculare, and in the molecular layer of the subiculum. There were only minor side-side and rostrocaudal differences in the distribution of tyrosine-hydroxylase and dopamine-beta-hydroxylase immunoreactive fibers. The identification of a putative dopaminergic projection to primate hippocampus, which is more dense and widely distributed than in the rodent, parallels similar increases in dopaminergic projections reported for primate cerebral neocortex.

[Surgical treatment of esophageal atresia--6 years of experience]

Surgical treatment of fourteen infants with esophageal atresia over the past six years was reviewed retrospectively. Two patients had esophageal atresia without tracheoesophageal fistula (Gross Type A), the other 12 patients had distal tracheoesophageal fistula (Gross Type C). Associated anomalies were found in three patients: one had a patent ductus arterious, another had trisomy 18, and the third had polydactylia. According to Waterston's risk group classification, there were 7 cases in Group A, 5 in Group B and 2 in Group C. The choice of operative method mainly depended on the distance between the two esophageal ends. Two patients with Type A atresia were treated by a staged operation because the distance between the two esophageal blind ends far exceeds 2 cm. A Type C patient with a "gap" longer than 2 cm who first had his esophagostomy, gastrostomy and ligation of the tracheoesophageal fistula at another hospital was transferred to us to get an esophageal reconstruction using a right-side ileocolon. Another ten Type C patients with a "gap" of less than 2 cm were operated on by extrapleural end-to-end esophago-esophagostomy after their tracheo-esophageal fistula was closed. The remaining Type C patient with a longer gap of about 3 cm was treated by primary anastomosis following mobilization of the upper pouch as well as limited mobilization of the lower esophageal segment. Anastomotic leakage was found in three patients. One patient developed subsequent stricture when the leakage was healed. The causes of mortality in three patients were pulmonary hemorrhage, sepsis and pneumonia respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

500-MHz proton NMR evidence for two solution structures of the common arm base-paired segment of wheat germ 5S ribosomal RNA

The base-pair protons of the common arm duplex fragment of wheat germ (Triticum aestivum) ribosomal 5S RNA have been identified and assigned by means of 500-MHz proton NMR spectroscopy. The two previously reported extra base pairs within the fragment [Li et al. (1987) Biochemistry 26, 1578-1585] are now explained by the presence of two distinct solution structures of the common arm fragment (and its corresponding base-paired segment in intact 5S rRNA). The present conclusions are supported by one- and two-dimensional proton homonuclear Overhauser enhancements in H2O and by temperature variation and Mg2+ titration of the downfield 1H NMR spectrum. The difference between the two conformers is most likely due to difference in helical tightness. Some additional amino proton resonances have also been assigned.

Wheat germ 5S ribosomal RNA common arm fragment conformations observed by 1H and 31P nuclear magnetic resonance spectroscopy

The nonexchangeable protons of the common arm fragment of wheat germ (Triticum aestivum) ribosomal 5S RNA have been observed by means of high-resolution 500-MHz 1H NMR spectroscopy in D2O solution. Although NMR studies on the exchangeable protons support the presence of two distinct solution structures of the common arm fragment (and of the same base-paired segment in intact 5S rRNA), only a single conformation is manifested in the 1H NMR behavior of all of the H6 and H5 pyrimidine and most of the H8/H2 purine protons under the same salt conditions. The nonexchangeable protons near the base-paired helix have been assigned by a sequential strategy. Conformational features such as the presence of a cytidine-uridine (C.U) pair at the loop-helix junction and base stacking into the hairpin loop are evaluated from nuclear Overhauser enhancement spectroscopy (NOESY) data. Double-quantum filtered correlation spectroscopy (DQF-COSY) experiments show that most of the 26 riboses are in the C3'-endo conformation. Finally, backbone conformational changes induced by Mg2+ and heating have been monitored by 31P NMR spectroscopy. Our results show that the common arm RNA segment can assume two conformations which produce distinguishably different NMR environments at the base-pair hydrogen-bond imino protons but not at nonexchangeable base or ribose proton or backbone phosphate sites.

Diltiazem as monotherapy in treatment of mild to moderate essential hypertension

The effectiveness and safety of diltiazem monotherapy was evaluated in 29 patients with mild to moderate essential hypertension (diastolic pressure between 95 and 115 mmHg). There were 16 men and 13 women, ages ranged from 29 to 58 years (mean 43). After a 2-week placebo period, each patient was given a 60 mg diltiazem tablet three times a day for 8 weeks. Blood pressure and heart rate were determined at weekly clinic visits. Three patients were withdrawn from the study because of a skin rash, palpitation and a frequent loose stool, respectively. In the remaining 26 patients, the mean systolic and diastolic blood pressures were reduced significantly in 2 weeks of therapy and thereafter. At the end of the 8-week treatment the mean supine blood pressure decreased from 158/103 at baseline to 139/94 mmHg, the mean sitting blood pressure from 156/104 to 136/93 mmHg, and the mean standing blood pressure from 151/104 to 134/96 mmHg. The heart rate did not change significantly before or during diltiazem treatment. In 16 (61.5%) of the 26 patients, diltiazem consistently reduced the diastolic blood pressure more than 5 mmHg throughout 2 to 8 weeks of treatment. The left ventricular mass and ejection fraction assessed with M-mode echocardiograms were normal before diltiazem treatment, and remained unchanged 8 weeks after the treatment. By using treadmill exercise tests, there was a significant increase in exercise duration and a significant reduction in the peak heart rate at 8 weeks after the treatment. The peak systolic blood pressure did not change significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of transcription of the Bacillus subtilis spoIIA locus

The start point of spoIIA transcription was defined by primer extension analysis with two separate primers. It was 27 bases upstream from the putative translation initiation codon of the first open reading frame in the spoIIA locus. A region extending at least 52 bases upstream from the transcription start site was necessary for transcription, as determined with integrative plasmids. Transcription of spoIIA was dependent on the spoOA, spoOB, and spoOF loci, but this dependency was partly overcome by increasing the number of copies of the spoIIA promoter region. Transcription of spoIIA was absolutely dependent on the spoOH locus, which codes for the RNA polymerase sigma factor sigma H. Regions approximately -35 and -10 upstream from the spoIIA transcription start site showed sequence homology with Bacillus subtilis sigma H promoters.

Covalent interactions of type IX collagen in cartilage

The cross-linking of type IX collagen in fetal bovine cartilage was investigated. The main cross-link was dihydroxy-lysinonorleucine (borohydride-reduced) with a lesser amount of the mature cross-link, pyridinoline. Dihydroxylysinonorleucine was present in all three chains of the COL2 domain of the type IX molecule, but only two of them contained pyridinoline even in mature cartilage. Amino acid sequence analysis of individual tryptic peptides that contained 3H-labeled cross-links showed that they had derived from sites of covalent interaction between type IX collagen and the telopeptide sequences of type II collagen. One two-chained peptide was a helical sequence of alpha 2 (IX) COL2 linked to an alpha 1 (II) N-telopeptide. A second peptide was a different helical sequence from another type IX chain linked to an alpha 1(II) c-telopeptide. This latter helical sequence was also the principal site of pyridinoline cross-linking in type IX collagen.

Sympathetic postganglionic innervation of the cardiac coronary artery in cats

The localization of the sympathetic postganglionic neurons innervating the cardiac coronary arteries of the cat was investigated using retrograde axonal transport with horseradish peroxidase. We found after the enzyme was applied to the main trunk of the right coronary artery, and to the main trunk and the terminal branch of the ventral descending vessels of the left coronary artery, the peroxidase-labeled sympathetic neurons were localized predominantly in the right stellate ganglia, with a few cells in the left stellate ganglia. There were very few labeled cells in the middle cervical, superior cervical, and T4-7 ganglia on both sides. After peroxidase application to the terminal branch of the dorsal descending vessels of the right coronary artery, labeled cells were mainly in the left stellate ganglia, with only a few cells in the right stellate ganglia.

Fine powdering exposes the mineral-protected collagen of bone to protease digestion

The method of heat-denaturation and trypsin digestion was used to dissect bone biochemically into mineral-protected and mineral-unprotected pools of collagenous matrix. It was found that varying the particle size of the bone powder had a profound effect on the results. Using mature bovine cortical bone, the observed pool of "unmineralized" (mineral-unprotected) collagen could be varied from 2% to more than 60% of the total bone collagen simply by decreasing the particle size of the bone sample from greater than 1 mm to less than 38 micron. No major differences were seen in the contents of hydroxypyridinium cross-links between the collagens of the trypsin-soluble and trypsin-insoluble pools from the fine powders, contrary to earlier reports. A trend to a higher content of these cross-links was evident, however, in the very small collagen pool extracted from the coarsest bone particles. Similar extraction differences were noted using bacterial collagenase to probe for mineral-protected vs. mineral-unprotected domains of bone collagen. In summary, the biochemical dissection results appear largely to be an artifact of the powdering technique, the shear energies of which presumably destroy the intimate physical relationship between the mineral crystallites and the collagen fibrils at the fractured surfaces of the bone particles. As the fractured surface area increases with decreasing particle size so the fraction of protease degradable collagen increases. Since powdering is routinely adopted for many structural studies on both the mineral and organic phases of bone, the findings on finely powdered bone should be interpreted cautiously.

The carboxypropeptide trimer of type II collagen is a prominent component of immature cartilages and intervertebral-disc tissue

Immature bovine cartilages and intervertebral-disc tissue all revealed a prominent protein, not present in the adult tissues, in non-denaturing extracts made with chondroitin ABC lyase (EC 4.2.2.4), Streptomyces hyaluronidase (EC 4.2.2.1) or 1 M NaCl. The protein ran on SDS-polyacrylamide electrophoresis, before disulphide reduction, as a close doublet of bands of apparent molecular weight 110,000 and 105,000. After reduction, they dissociated respectively into two protein bands at 37,000 and 35,000, indicating that the initial molecules were disulphide-bonded trimers. Amino-terminal sequence analysis established the identity of both proteins (Mr 110,000 and Mr 105,000) as forms of the carboxypropeptide of type II collagen. The larger molecule appeared to be the trimer of intact alpha 1(II) carboxypropeptides and the smaller, a version composed of chains that were ten residues shorter at their amino-terminal ends. The material appears to be identical to chondrocalcin, a protein previously found to be enriched in fetal growth plate and named on the basis that it may play a role in cartilage calcification. The present findings, however, indicate that the protein is equally abundant in all type II collagen-synthesizing young cartilages, including nucleus pulposus of the intervertebral disc and other cartilages that never calcify.

Type VI collagen of the intervertebral disc. Biochemical and electron-microscopic characterization of the native protein

The collagen framework of the intervertebral disc contains two major fibril-forming collagens, types I and II. Smaller amounts of other types of collagen are also present. On examination of the nature and distribution of these minor collagens within bovine disc tissue, type VI collagen was found to be unusually abundant. It accounted for about 20% of the total collagen in calf nucleus pulposus, and about 5% in the annulus fibrosus. It was discovered by serially digesting disc tissue with chondroitin ABC lyase and Streptomyces hyaluronidase that native covalent polymers of type VI collagen could be extracted. Electron micrographs of this material prepared by rotary shadowing revealed the characteristic dimensions of tetramers and double tetramers of type VI molecules, with their central rods and terminal globular domains. Molecular-sieve column chromatography on agarose under non-reducing non-denaturing conditions gave a series of protein peaks with molecular sizes equivalent to the tetramer, double tetramer and higher multimers. On SDS/polyacrylamide-gel electrophoresis after disulphide cleavage, these fractions of type VI collagen all showed a main band at Mr 140,000 and four lesser bands between Mr 180,000 and 240,000. On electrophoresis without disulphide cleavage in agarose/2.4% polyacrylamide only dimeric (six chains) and tetrameric (12 chains) forms of type VI molecules were present. The ability to extract all the type VI collagen of the tissue in 4 M-guanidinium chloride, and absence of aldehyde-mediated cross-linking residues on direct analysis, showed that, in contrast with most matrix collagens, type VI collagen does not function as a covalently cross-linked structural polymer.

Erythrocyte sedimentation rate and C-reactive protein values in patients with total hip arthroplasty

Serum C-reactive protein (CRP) levels and erythrocyte sedimentation rates (ESR) were measured serially in 50 osteoarthritic patients treated with uncomplicated primary total hip arthroplasties (THAs) and also in 28 patients with painful hip for different periods after THA. The follow-up period was one year. In uncomplicated primary THA, the ESR was slightly elevated before surgery and was variable after surgery; some patients continued to have abnormally high ESRs one year after surgery. However, CRP was normal before surgery and after surgery showed a distinctive pattern that rapidly normalized within three weeks. In patients with a painful hip after THA, ESR was elevated in those with septic loosening and variable in those with mechanical loosening; however, the difference was not significant. ESR after successful revision THA was also variable. CRP was high in patients with septic loosening and normal in those with mechanical loosening. Normalization of CRP was rapid after control of infection or within three weeks of successful revision THA. Uneventful recovery after THA is indicated by normalization of CRP within three weeks, regardless of ESR. Measurement of both ESR and CRP is helpful in differentiating septic and mechanical loosening, detecting complications, and monitoring the effects of treatment, but CRP is more informative and sensitive than ESR for these purposes.

Computed tomography of a meniscal cyst

A meniscal cyst of the knee is a rare lesion, and a palpable large meniscal cyst is even more rare. This article suggests that CT scan demonstrates clear location, size, contents, and connection of the cyst with meniscus and peripheral tissue. By a combination of arthrography and CT scan, detection of the cysts in zone 3 (parameniscal area) is possible with ample demonstration of whether the cyst is associated with a meniscal tear. This provides a guideline in determining the treatment of the lesion.

Collagen type IX: evidence for covalent linkages to type II collagen in cartilage

A major site of pyridinoline cross-linking in bovine type IX collagen was traced to a tryptic peptide derived from one of the molecule's HMW chains. This peptide gave two amino acid sequences (in 2/1 ratio) consistent with it being a three-chained structure. The major sequence matched exactly that of the C-telopeptide of type II collagen from the same tissue. A second HMW chain that contained pyridinoline cross-links also gave two amino-terminal sequences, one from its own amino terminus, the other matching exactly the N-telopeptide cross-linking sequence of type II collagen. We conclude that type IX collagen molecules are covalently cross-linked in cartilage to molecules of type II collagen, probably at fibril surfaces.

A growing family of collagens in articular cartilage: identification of 5 genetically distinct types

Cartilage displays an extensive polymorphism of collagen types. All hyaline cartilages are known to contain type II collagen (90-95% of the collagen) and 2 other cartilage-specific minor collagens called types IX (or M) and XI (or 1 alpha 2 alpha 3 alpha). In the present work, the molecular heterogeneity of articular cartilage collagen was investigated in more detail. Two additional genetic types of collagen were found in the mature bovine tissue, types V and VI, each accounting for about 1-2% of the tissue dry weight. Type V, a close relative of type XI, apparently had accumulated after birth. Type VI is a short-helix, microfibrillar collagen of wide tissue distribution but unknown function. In understanding the physical changes in the collagen network of cartilage that are believed to herald the onset of cartilage degeneration in osteoarthrosis, all five of these collagen types deserve attention.

500-MHz proton homonuclear Overhauser evidence for additional base pair in the common arm of eukaryotic ribosomal 5S RNA: wheat germ

A "common-arm" fragment from wheat germ (Triticum aestivum) 5S RNA has been produced by enzymatic cleavage with RNase T1 and sequenced via autoradiography of electrophoresis gels for the end-labeled fragments obtained by further RNase T1 partial digestion. The existence, base pair composition, and base pair sequence of the common arm are demonstrated for the first time by means of proton 500-MHz nuclear magnetic resonance. From Mg2+ titration, temperature variation, ring current calculations, sequence comparisons, and proton homonuclear Overhauser enhancement experiments, additional base pairs in the common arm of the eukaryotic 5S RNA secondary structure are detected. Two base pairs, G41 X C34 and A42 X U33 in the hairpin loop, could account for the lack of binding between the conserved GAAC segment of 5S RNA and the conserved Watson-Crick-complementary GT psi C segment of tRNAs.

External skeletal fixation of canine tibial osteotomies. Compression compared with no compression

In this study we compared the effects of compression on the maturity and pattern of osseous healing in canine tibial osteotomies that were fixed with an external fixation system at a single time-period, ninety days after osteotomy. The in vitro model demonstrated that compression increased rigidity of fixation. Relative to the rigidity of the intact tibia, this increase was small. Estimation of osteotomy-site bone blood flow at ninety days by 85Sr clearance and torsional testing to failure of the healed osteotomies were used to compare the maturity of bone union in each group. The pattern of healing of the osteotomy was evaluated by quantitative histological determination of new-bone formation and porosity. All of the osteotomies healed by the ninetieth day. We found no significant difference at that time in osteotomy-site bone blood flow or strength of healing of the osteotomy, although the compression-treated osteotomies healed with higher torsional stiffness. No differences were demonstrated between the two groups in the pattern of healing of the osteotomy. In both groups there was a significantly greater amount of periosteal new-bone formation in the relatively less rigidly fixed antero-posterior plane when compared with the mediolateral plane. Primary bone-healing of both the contact type and the gap type was seen in both groups. There were no significant complications and the pin-loosening rate was similar in both groups.