[Clinical analysis of intrapulmonary lymph nodes]

We encountered 12 cases (9 men, 3 women) of intrapulmonary lymph nodes, discovered by chest radiography or chest CT and identified by thoracoscopic lung biopsy (in 10 cases), open lung biopsy (1 case) or lobectomy (1 case). We also studied the literature related to intrapulmonary lymph nodes in Japanese. Many intrapulmonary lymph nodes were found in the lower lung field, few in the upper lung field. All intrapulmonary lymph nodes were spherical and were located under the pleura, but we were not able in some cases to differentiate them from malignancies by the CT scanfindings. We could not diagnose them or rule out malignancy before surgery. Pathological findings revealed that all of them showed anthracosis. Silicotic changes were found in three cases. We consider that thoracoscopy is useful in making a definite diagnosis if peripheral pulmonary lesions cannot be diagnosed. We emphasize that intrapulmonary lymph nodes should be taken into consideration in differential diagnoses of small nodular lesions in the lung.

NADH-dependent dehydroascorbate reductase in the rabbit lens

The present investigation demonstrates the existence of NADH-dependent dehydroascorbate (DHA) reductase activity in the soluble fraction of the rabbit lens. This DHA reductase was specific for NADH, and its apparent Km values for DHA and NADH were 5.7 mM and 4.0 microM, respectively. In a gel filtration of the lens soluble fraction on a Sephadex G-75 superfine column, the NADH-dependent DHA reductase activity was eluted at the oligomeric betaL1-crystallin fraction, which may also contain lambda-crystallin (a rabbit-specific crystallin). Furthermore, about 80% of protein fractions separated from the betaL1-crystallin fraction by DEAE-cellulose ion-exchange column chromatography exhibited DHA reductase activity. In the SDS-PAGE analysis of the protein fractions with DHA reductase activity, 32-33, 27 and 25 kDa protein subunits were commonly identified. These results suggest that oligomers of beta-crystallin and/or lambda-crystallin subunits may be associated with the DHA reductase activity. The present paper also discusses that the function of the reductase may be to enhance the antiphotoxidation capacity of the lens.

[Sjögren's syndrome with multiple bullae and pulmonary nodular amyloidosis]

We report a case of Sjögren's syndrome with pulmonary involvement diagnosed by open lung biopsy. The patient was a 62-year-old woman with antiphospholipid antibody syndrome. Her chest radiograph and CT scan showed multiple bullae diffusely scattered throughout the lung. The open lung biopsy specimens revealed marked inflammatory mononuclear cell infiltration and nodular amyloid deposits in the bronchiolar walls. The mechanism of bulla formation appeared to be the check valve mechanism caused by the narrowing of the airway by the bronchiolitis. The patient was treated with oral corticosteroids, and her symptoms and laboratory findings became stable.

Conformational difference between mono- and diprotonated cis-2,5-diphenylpiperazinium salts in the solid state

Monohydrochlorides of cis-2,5-diphenylpiperazine assume a chair conformation, while the corresponding dihydrochlorides assume a boat form regardless of the substituent(s) at the nitrogen atom.

[A case of colon cancer with tension pneumothorax and empyema as a consequence of colo-pleural fistula]

A 63-year-old man was admitted to our hospital with fever and chest pain. Chest radiography revealed left pleural effusion with left pneumothorax and small nodular shadows in the right lung field. On CT of the chest and abdomen, multiple nodules were seen in both lung fields, and masses appeared in the liver and spleen. Fiberoptic colonoscopy showed obstruction at the end of the transverse colon. Biopsy of this obstruction proved it to be cancer. In this patient, a colo-pleural fistula was also diagnosed using thoracoscopy under local anesthesia and from the inflow of contrast medium from the colon into the thoracic cavity seen in abdominal radiographs. This was a rare case of a colo-pleural fistula without diaphragmatic deficiencies. Medical thoracoscopy is useful for the diagnosis of complicated pleural effusions as was seen in this case.

Effects of inhalation of nitroglycerin on hypoxic pulmonary vasoconstriction

Recent studies suggest that nitric oxide (NO) may play an important role in the pathophysiology of pulmonary hypertension. Nitroglycerin is metabolized to NO, which is a potent vascular smooth muscle relaxant. The aim of the present study was to compare the effects of inhaled and infused nitroglycerin on pulmonary hemodynamics and gas exchange in anesthetized, artificially ventilated dogs. Nitroglycerin was administrated either by inhalation or by infusion. Systemic blood pressure (SBP), pulmonary arterial pressure (PAP), and pulmonary capillary wedge pressure (PCWP) were measured, and cardiac output was estimated by an electromagnetic flowmeter. Blood gas measurements were performed during hypoxic gas exposure (FiO2; 0.1) with a continuous inhalation or infusion of nitroglycerin (1, 2.5 micrograms/kg/min). Inhaled (n = 4) and infused (n = 4) nitroglycerin (1 microgram/kg/min) did not produce any detectable effects on the hemodynamics. Inhaled nitroglycerin (2.5 micrograms/kg/min) reduced SBP, PAP and calculated pulmonary vascular resistance (PVR) in all dogs. Cardiac output did not change. In addition, inhaled nitroglycerin increased PaO2. In contrast, the continuous infusion of nitroglycerin (2.5 micrograms/kg/min) did not change in PAP, whereas infused nitroglycerin decreased the mean SBP. Infused nitroglycerin did not alter cardiac output and calculated PVR. A decreased PaO2 was noted in 2 dogs on nitroglycerin infusion. These findings indicate that inhaled nitroglycerin effects the pulmonary circulation relatively more than infused nitroglycerin, which tends to have more of a general effect on the systemic circulation. The effects of inhaled nitroglycerin may thus be comparable to the effects of NO inhalation.

Apraxic agraphia due to thalamic infarction

The authors report a patient of pure apraxic agraphia with normal praxis due to left thalamic infarction. 15O-gas-PET showed reduced oxygen metabolism in the left thalamus and the left dorsolateral premotor area, while MRI and 11C-fulumazenil-PET showed no remarkable lesions in the frontal cortex. The patient's word imaging remained normal. The authors hypothesize that thalamic destruction causes pure apraxic agraphia by exerting a remote effect on left dorsolateral premotor area and blocking somewhere between graphemic area and motor programming.

[Ascorbate free radical reductase activity in vertebrate lenses of some species]

PURPOSE

To clarify the function of ascorbate free radical (AFR) reductase in the lens antioxidation mechanism, we investigated the difference among species in AFR reductase activity in different vertebrate lenses.

MATERIALS AND METHODS

Soluble and insoluble fractions were prepared from the lenses of frogs, guinea pigs, rats, rabbits, pigs, and calves. AFR reductase and diaphorase activity of each fraction was determined.

RESULTS

AFR reductase activity in the lens soluble fraction was the highest in frogs. That of guinea pigs and rabbits was at the next level; there was only a little activity in rats and pigs, and none was detected in calves. Membrane-bound AFR reductase in the lens insoluble fraction was extracted by 0.3% Triton X-100. The membrane-bound enzyme activity was almost at the same level in frogs, rats, rabbits, and calves, and a little higher in guinea pigs and pigs. However, such species-specificity of AFR reductase activity as in the soluble fraction was not observed in 0.3% Triton X-100 extracts. Diaphorase activity was 3 to 9 times as much as AFR reductase activity in the soluble fractions of frogs, guinea pigs, and rabbits, but in 0.3% Triton X-100 extracts of all vertebrate species used, it was very high, 108 to 311 times the AFR reductase activity.

CONCLUSION

These results suggest that the lens soluble and membrane-bound AFR reductases are individual enzyme molecules and have different antioxidative functions. The lenses of frogs, guinea pigs, and rabbits contain a near-ultraviolet (UV) light absorbing compound, reduced pyridine nucleotide at a high concentration. Therefore, the soluble AFR reductase activity may be high in the vertebrate lenses with a near-UV light filter, and enhance the antiphotoxidation of ascorbic acid.

[A case of callosal apraxia without agraphia and acquired stuttering associated with callosal infarction]

We report a 52-year-old right-handed man with cerebral infarction of the right anterior cerebral artery area. The MRI findings showed cerebral infarction in the trunk of the right corpus callosum, although some part of the posterior half of the trunk was spared. Some part of right precuneal gyrus, cingulate gyrus were also involved. The clinical feature of this case is characterized by following two points. First, although callosal apraxia is usually accompanied by agraphia, he showed apraxia with the left hand, but showed no agraphia. Secondary, he showed speech dysfluency mainly characterized by initial syllable repetitions. The nature of this speech dysfluency was determined as acquired stuttering. This case suggests that the pathway for praxis locates distinct portion from that for writing on corpus callosum. We analyzed callosal lesions of previous studies reporting callosal apraxia without agraphia, then compared to that of this case. And we also reviewed acquired stuttering report caused by callosal lesions. Consequently, we suggest that apraxia and stuttering were caused by damage of the trunk of the corpus callosum. While writing was preserved by the intact fibers in the posterior half of the trunk.

FD-891, a structural analogue of concanamycin A that does not affect vacuolar acidification or perforin activity, yet potently prevents cytotoxic T lymphocyte-mediated cytotoxicity through the blockage of conjugate formation

FD-891 belongs to a group of 18-membered macrolides, and is a structural analogue of a specific inhibitor of vacuolar type H+-ATPase, concanamycin A (CMA). In our previous work, we have shown that CMA specifically inhibits perforin-dependent cytotoxic T lymphocyte (CTL)-mediated cytotoxicity through the degradation and inactivation of perforin, although CMA does not affect Fas ligand (FasL)-dependent cytotoxicity. Here, we show that FD-891 potently prevents not only perforin-dependent but also FasL-dependent CTL-mediated killing pathways by blocking CTL-target conjugate formation. In contrast to CMA, FD-891 was unable to inhibit vacuolar acidification and only slightly decreased the perforin activity in lytic granules. FD-891 blocked granule exocytosis in response to anti-CD3, mainly owing to the lack of CTL binding to immobilized anti-CD3. The conjugate formation was markedly inhibited only when effector cells were pretreated with FD-891. Consistent with these observations, fluorescence-activated cell sorter (FACS) analysis for cell surface receptors revealed that FD-891 significantly reduced the expression of the T-cell receptor (TCR)/CD3 complex. These data suggest that the blockage of conjugate formation and subsequent target cell killing might be at least partly owing to FD-891-induced down-regulation of the TCR/CD3 complex.

Glochidionolactones A-F: butenolide glucosides from leaves of Glochidion zeylanicum (GAERTN) A. JUSS

From the leaves of Glochidion zeylanicum, six new butenolide glucoside, named glochidionolactones A-F, were isolated along with a known related compound, phyllanthurinolactone. The structures of glochidionolactones A-D and F were elucidated mainly by spectroscopic analyses. The absolute stereochemistry of glochidionolactone E was established by X-ray crystallographic analysis.

[Multiple intrapulmonary rheumatoid nodules]

A 66-year-old woman who had been treated at a nearby hospital since 1977 for rheumatoid arthritis complained of cough. Chest X-ray films disclosed multiple nodular shadows with cavitation in the fields of both lungs. The patient was admitted to our hospital and a thoracoscopic lung biopsy was performed. Histologically, the nodule consisted of necrotizing granuloma, indicating a necrobiotic nodule. Rheumatoid nodule was diagnosed because the patient exhibited rheumatoid arthritis. The chest X-ray shadow disappeared without medication. Rheumatoid nodules without coniosis are uncommon, but should be considered in the differential diagnosis of lung nodular lesions in patients with rheumatoid arthritis.

Human subtilisin-like proprotein convertase, PACE4 (SPC4) gene expression is highly regulated through E-box elements in HepG2 and GH4C1 cells

PACE4 (SPC4) is a member of the mammalian subtilisin-like proprotein convertase (SPC) family, which participates in maturation of precursor proteins. PACE4 is expressed at high levels in the anterior pituitary, central nervous system, the developing olfactory bulb, heart, and liver. Recently, we determined the gene structure of human PACE4. [Tsuji et al. (1997) J. Biochem. 122, 438-452]. The 5'-flanking region of PACE4 gene contains 12 E-boxes (E1 to E12) within 1 kb upstream of the transcription initiation site. To examine the function of these E-box elements in the regulation of PACE4 expression, deletion and mutation constructs of the 5'-flanking region were ligated to the luciferase gene and analyzed for promoter activity in HepG2 and GH4C1 cells, which express PACE4 at high level. Some differences were observed in the activity of each promoter construct between HepG2 and GH4C1 cells, although the overall profiles of activity for the promoter fragment series were similar regardless of cell type. We showed that the basal promoter activity of the PACE4 gene is first determined by sequences lying between -315 and -1 bp and further regulated by positive and negative elements in the upstream region. Site-directed mutagenesis of E-boxes in these regulatory elements showed that the E10 E-box act as positive regulator, whereas an E-box cluster (E4-E9) acts as a negative regulator in both cells. E2 E-box acts as a positive regulator only in HepG2 cells. Other E-boxes (E1, E3, and E12) had no effect on the promoter activity. These results indicate that E-box elements play a critical role in controlling PACE4 expression in HepG2 and GH4C1 cells and that PACE4 expression is regulated by a mechanism distinct from that of other SPC family proteases.

[Orthostatic transient unresponsiveness in an elderly patient with severe cerebral arteriosclerosis under antihypertensive medication]

An 80-year-old man who had was administered antihypertensive medication showed repeated transient unresponsiveness during standing and/or walking. Neurological examination showed no focal neurological signs except mild dementia. Head-up tilting examination induced unresponsiveness and a decrease of systolic blood pressure from 111 mmHg to 86 mmHg. This unresponsiveness disappeared 3 minutes later when the blood pressure recovered to 102/64 mmHg. Cerebral angiography demonstrated occlusion in the right internal carotid artery and the right vertebral artery. Severe stenosis was observed at the left internal carotid artery and the left vertebral artery. Discontinuance of the antihypertensive medication reduced the frequency of orthostatic transient unresponsiveness. Elastic stockings in the lower extremities completely prevented the attack; head-up tilting did not induce hypotension with elastic stockings. The transient unresponsiveness in the present case was probably correlated to hemodynamic failure under the condition of severe cerebral arteriosclerosis.

Elevated plasma brain natriuretic peptide levels in chronic respiratory failure with cor pulmonale

Elevated plasma brain natriuretic peptide (BNP) levels have been described in patients with congestive heart failure and acute myocardial infarction. We measured plasma BNP levels in patients with chronic respiratory failure to evaluate the correlation between plasma BNP levels and pulmonary haemodynamics. Plasma BNP levels were measured in 28 patients with chronic respiratory failure accompanied by three underlying diseases [14 with chronic obstructive pulmonary disease (COPD), seven with sequelae of pulmonary tuberculosis (sequelae Tbc) and seven with diffuse panbronchiolitis (DPB)] by immunoradiometric assay methods (IRMA). Twenty-one of 28 patients had already received oxygen supplementation and 16 of 21 patients were treated as outpatients with home oxygen therapy. Plasma BNP levels were significantly elevated in patients with chronic respiratory failure complicated by cor pulmonale (81.5 +/- 13.1 pg ml-1) compared to patients without cor pulmonale (13.3 +/- 2.7 pg ml-1, P < 0.001). As controls, plasma BNP levels in 10 patients with primary lung cancer were studied, and the results (3.5 +/- 1.0 pg ml-1) were not significantly different from those of patients with chronic respiratory failure without cor pulmonale. Plasma BNP levels in 12 healthy subjects were also studied, and the results (7.2 +/- 1.0 pg ml-1) were not significantly different from those of the control subjects. Plasma BNP levels showed a weak linear correlation with systolic pulmonary arterial blood pressure, estimated by Doppler echocardiography (r = 0.43; P = 0.068), but there was no significant correlation between BNP levels and the degree of hypoxaemia (r = 0.30; P = 0.138). Plasma atrial natriuretic peptide (ANP) levels in patients with chronic respiratory failure were also measured using the same samples. Plasma ANP levels were also significantly elevated in patients with chronic respiratory failure complicated by cor pulmonale (80.8 +/- 12.1 pg ml-1) compared to patients without cor pulmonale (26.1 +/- 4.4 pg ml-1, P = 0.003). A significant correlation was found between plasma BNP and ANP levels (r = 0.68; P < 0.001). Our results suggest that the plasma BNP or ANP level may be a useful indicator for detecting the presence of cor pulmonale in patients with chronic respiratory failure.

[A case report of pure micrographia progressing over 5 years--an early sign of "pure akinesia"?]

We report a 68-year-old man who have had only slowly progressive micrographia in both hands over the past 5 years without rigidity, tremor, bradykinesia, and festination or freezing in walking. The fine finger movements were normal. PET studies suggested the diagnosis of progressive supranuclear palsy or pure akinesia. Administration of L-DOPA and L-threo-DOPS did not improve his micrographia. Festination and freezing in writing may contribute to the genesis of micrographia in this case. We postulate that "pure micrographia" is an early atypical sign of pure akinesia.

Protein kinase C-activated oxidant generation in endothelial cells signals intercellular adhesion molecule-1 gene transcription

We tested the hypothesis that activation of protein kinase C (PKC) and generation of oxidants are critical sequential signals mediating tumor necrosis factor (TNF)-alpha-induced activation of nuclear factor-kappaB (NF-kappaB) and transcription of the intercellular adhesion molecule (ICAM)-1 gene. Stimulation of human pulmonary artery endothelial (HPAE) cells with TNF-alpha (100 U/ml) induced the activation of PKC and, subsequently, generation of oxidants. Pretreatment with calphostin C, a specific PKC inhibitor, prevented oxidant generation after TNF-alpha stimulation, indicating that PKC activation mediated the production of oxidants in HPAE cells. In contrast, pretreatment of HPAE cells with N-acetylcysteine, an antioxidant and a precursor of glutathione, failed to prevent PKC activation, indicating that PKC activation was not secondary to the oxidant production. These findings suggest that oxidant generation in endothelial cells occurs downstream of PKC activation. However, both PKC activation and oxidant generation were necessary for ICAM-1 mRNA expression because the pretreatment of HPAE cells with either calphostin C or N-acetylcysteine inhibited the TNF-alpha-induced activation of NF-kappaB and prevented the activation of ICAM-1 promoter. Prolonged exposure of HPAE cells to the phorbol ester, phorbol-12-myristate-13-acetate, which is known to deplete all except atypical PKC isozymes, failed to prevent TNF-alpha-induced ICAM-1 mRNA expression. We conclude that TNF-alpha-induced oxidant generation secondary to the activation of a phorbol ester-insensitive PKC isozyme signals the activation NF-kappaB and ICAM-1 gene transcription.

E-selectin expression in human endothelial cells by TNF-alpha-induced oxidant generation and NF-kappaB activation

Because reactive oxygen species (ROS) can function as second messengers and regulate the activation of the transcription factor nuclear factor (NF)-kappaB, we investigated the possible role of tumor necrosis factor-alpha (TNF-alpha)-induced ROS generation in endothelial cells in signaling E-selectin gene transcription. We demonstrated that stimulation of human pulmonary artery endothelial cells with TNF-alpha (100 U/ml) resulted in ROS production using the oxidant-sensitive dye 5 (and 6)-carboxy-2',7'-dichlorodihydrofluorescein diacetate bis(acetoxymethyl)ester. Pretreatment with N-acetyl-L-cysteine (NAC) or pyrrolidine dithiocarbamate (PDTC) for 0.5 h inhibited TNF-alpha-induced generation of ROS as well as activation of NF-kappaB and E-selectin mRNA and the cell surface protein expression. These findings indicate that TNF-alpha induces NF-kappaB activation and the resultant E-selectin gene expression by a pathway that involves formation of ROS and that E-selectin expression can be inhibited by the antioxidant action of NAC or PDTC. The results support the hypothesis that generation of ROS in endothelial cells induced by proinflammatory cytokines such as TNF-alpha is a critical signal mediating E-selectin expression.

Progressive aphemia in a patient with Pick's disease: a neuropsychological and anatomic study

We describe a patient with progressive aphemia with agrammatism that was later overlaid with buccofacial apraxia and pseudobulbar palsy. Pathological findings were consistent with those of classic Pick's disease with argyrophilic inclusions and neuronal achromasia, except for restricted cortical atrophy in the frontal operculum posterior to the pars opercularis (Brodmann Area 44). In addition, major neuronal loss was confined to the premotor cortex and the anterior half of the precentral gyrus (Area 6), which apparently explained the aphemia. The present case demonstrated that classic Pick's disease can show quite limited cortical atrophy in a patient who clinically presents with progressive aphemia. Also, our patient differed from the progressive non-fluent aphasia patients reported as having Pick's disease, who were all Pick variants, revealing that classic Pick's disease can be included in the spectrum of progressive aphasia syndrome.

Autologous Tissue Breast Reconstruction Following the Application of Tissue Expander

Breast reconstruction is usually performed with autologous tissue or mammary prostheses, and a single mothod is generally selected for the most reconstruction cases. We combined these two methods of breast reconstruction. In the first stage, a tissue expander was applied to maintain space for the breast, and in the next stage the space was replaced with autologous tissue. This combined method was performed in 7 cases with good results. Some advantages of this method became clear, especially in the case of immediate breast reconstruction: 1) the patient has time to objectively consider breast reconstruction using autologous tissue after the emotional trauma of mastectomy had subsided 2) no additional surgical scar remains on the chest wall 3) the exact site and the exact amount of autologous tissue can be ascertained by measuring the volume of the tissue expander 4) there is no breast-less period, and 5) the patient's daily life is unaffected. We believe this combined procedure will contribute to a better quality of life for those who experience breast cancer and mastectomy as well as other conventional reconstructive procedures.

[A case of pure agraphia due to left parietal lobe infarction]

We reported a case of a 63-year-old right handed man with pure agraphia due to the left parietal lobe infarction. The characteristics of agraphia in the patient were as follows. 1) The written letters were generally recognizable and well formed. 2) He succeeded in pointing to single Kana letter named by the examiner from the Japanese syllabary, but missed in pointing to Kana words. 3) Further, it took more time for the patient to point to even single Kana letter than for the control. 4) Most errors in Kana writing was substitution. Errors in Kanji writing are partial lacking or no response. But his ability in Kanji writing was facilitated by visual cues. He was unable to describe the Hen (a left-hand radical) and Tsukuri (the body) of some Kanji letters and to name some Kanji letters when their Hen and Tsukuri were orally given. We classified pure agraphia into two types out of some references. In one type (Type 1), letters in writing are poorly formed, but the ability to make words with the methods other than writing, for example spelling with anagrams or typing are preserved. In another type (Type 2), letters in writing were well-formed, but spelling with anagrams or typing were abnormal. Type 1 agraphia could result from the only deficit of graphic motor engram, while type 2 agraphia could be caused by the deficits other than graphic motor engram. Agraphia in this case belongs to the type 2. The features of agraphia in this case suggested that his agraphia was caused by a disorder in recalling graphemes of letters, and in arranging at least of Kana-letters.

Blood supply to the latissimus dorsi muscle and muscle performance during co- or counterpulsatile stimulation for circulatory assist

For the application of the latissimus dorsi muscle (LDM) to circulatory assist, the muscle is stimulated with co- or counterpulsation during the cardiac cycle. The purpose of this study was to evaluate the blood supply to the LDM and its muscular performance during each respective stimulation. The origin of the LDM was connected to a tension gauge, a potentiometer, and 1 kg of weight in series. The LDM was stimulated at a ratio of 1:1 of heart to muscle contraction for 10 min. Copulsatile stimulation made thoracodorsal arterial flow (TDF) predominant during cardiac diastole. In counterpulsatile stimulation, TDF occurred predominantly during cardiac systole. Between the 2 patterns of stimulation, no significant differences were observed in the mean TDF rate during 1 cardiac cycle. The maximal force, maximal contraction length, and power of the LDM also did not differ significantly. These results suggest that despite the difference of the TDF profile, LDM performance may be comparable between co- and counterpulsatile stimulation for the application of the LDM to circulatory assist.

Genomic organization and alternative splicing of human PACE4 (SPC4), kexin-like processing endoprotease

PACE4 (paired basic amino acid cleaving enzyme) is a member of a family of the mammalian kexin-like proprotein convertases containing a subtilisin-like catalytic domain. Previously we reported seven isoform mRNAs of PACE4 that vary in size and 3'-coding sequence [A. Tsuji et al. (1994) Biochem. Biophys. Res. Commun. 200, 943-950; K. Mori et al. (1997) J. Biochem. 121, 941-948]. To determine the origin of these isoforms, the entire human PACE4 gene has been isolated as a set of overlapping genomic DNA fragments, and analyzed by restriction enzyme digestion and nucleotide sequence determination. The human PACE4 gene spans at least 250 kb and is distributed over 25 exons that range in size from 39 to 1,422 base pairs. Human PACE4 gene is the largest kexin-like proprotein convertase gene reported to date. The most striking feature of its genomic structure is the size of the introns and the number of exons, although the general organization of signal peptide, propeptide, and catalytic domains, which are conserved in this family, is very similar to that reported for other kexin-like protease genes. The structural analysis of PACE4 genomic DNA indicates that multiple PACE4 transcripts are produced as a consequence of alternative RNA splicing events, including exon skipping, and differences in the usage of the inner 5'-splicing donor and polyadenylation sites. A major transcriptional start site was detected 314 bp upstream from the ATG translational start site by primer extension analysis. Sequence analysis of the 5'-flanking region revealed that PACE4 gene lacks TATA and CCAAT boxes in the proximal upstream region of the start site, although potential binding sites for several transcription factors including SP1, AP1, AP2, PEA3, Ets-1, GHF (growth hormone factor)-1, CREB (cyclic AMP response element binding protein), and basic helix-loop-helix proteins, were present. An unusual sequence of six tandem repeats of a nonadecamer (GGCCTGGGGGTTCACCTGC) containing an E box is found in the 5'-flanking region. These results suggest that PACE4 is not a constitutive gene product and its expression is regulated by various transcription factors.

Monitoring and regulating latissimus dorsi muscle performance for circulatory assist

The purposes of this study were monitoring and regulating latissimus dorsi muscle (LDM) performance with muscle internal pressure and thickness, and with burst stimulation parameters, respectively. The unconditioned LDM flap of a pig was connected to a measurement system to examine force and contraction length. Internal pressure was measured using a catheter pressure transducer with a fluid-filled balloon inserted into the muscle, and correlated linearly with force during both contraction and relaxation. During contraction, thickness change correlated linearly with contraction length and the area enclosed within an internal pressure-thickness curve, and the X-axis was correlated linearly with muscle work. Stroke work increased incrementally according to the pulse width up to 6.72 msec or burst rate up to 120 Hz, and then plateaued at 240 Hz. The authors conclude that muscle work during contraction could be monitored with internal pressure and thickness, and that stroke work could be regulated with pulse width or burst rate.