Expression of Forssman antigen in human large intestine

Forssman antigen is a commonly occurring heterophile antigen but is thought not to be present in most humans. Recent biochemical studies, however, have shown the presence of Forssman antigen in several forms of human cancer, including gastric, colon, and lung cancers. Immunohistochemical staining with both monoclonal and polyclonal antibodies has failed to demonstrate this antigen in human tissues. In this study we conclusively demonstrated the presence of Forssman antigen in cytoplasm of colon goblet cells, especially those in the so-called transitional mucosa adjacent to carcinoma. Specimens from 69 of 70 patients with colon cancer contained the antigen in goblet cells in transitional mucosae. The antigen was successfully demonstrated only after removal of sialic acid by alkaline hydrolysis-neuraminidase digestion. Localization of the antigen was quite different from that of Tn and human blood group A, B, and H antigens. This antigen was thought to be associated exclusively with globo-series glycolipids, and its existence in glycoproteins has not been conclusively demonstrated. However, the results presented here, based on proteolytic digestion and lipid extraction studies, strongly suggest that the antigen is also contained in glycoproteins.

Transient and localized expression of bone morphogenetic protein 4 messenger RNA during fracture healing

Temporal and spatial distribution of a gene encoding murine bone morphogenetic protein 4 (mBMP-4) during fracture repair were investigated in mice by RT-PCR and in situ hybridization. For in situ hybridization, fractured ribs and surrounding tissues were decalcified and hybridized with a mBMP-4-specific complementary RNA probe labeled with digoxigenin-11 UTP. mBMP-4 messenger RNA (mRNA) was not detected in ribs without fracture, whereas it was detected only in the early phase of fracture from 12 to 72 h after the onset of fracture before new cartilage or bone formation. The mBMP-4 mRNAs were present in cells distributed in three distinct regions, namely, the proliferating periosteum, the medullary cavity, and the muscles near the fracture site. These BMP-4-positive cells did not express bone gla protein mRNA, which is a marker of the mature osteogenic cell. RT-PCR also showed a transient increase in the level of BMP-4 mRNA in the early phase of fracture repair. The findings provide us with some new information. (1) The BMP-4 gene is produced by less differentiated osteoprogenitor cells, not by differentiated osteoblasts. (2) The BMP-4 gene is enhanced by the impact of fracture and localized in callus-forming tissue before callus formation. Together with the activities of BMP-4, as was previously described, our results suggest that newly produced BMP-4 gene product is one of the local contributing factors in callus formation in the early phase of fracture healing.

The use of a human dura mater allograft for the repair of a contaminated abdominal wall defect: report of a case

A case report of an infected full-thickness abdominal wall defect treated successfully with a human dura mater allograft is presented. A review of the literature and a discussion of prosthetic abdominal wall repair is also included. A 46-year-old woman presented with multiple small bowel perforations and a large abdominal wall defect due to a motor vehicle collision. A gamma-irradiated human dura mater prosthesis was used to repair the large abdominal wall defect which had been infected by a jejunal fistula. After more than 4 years of follow-up, the patient is free of complications, including wound infection, herniation, and ileus. The human dura mater allograft is thus considered to be a useful prosthesis for repairing potentially infected wounds.

Hyperbaric oxygen combined with nicardipine administration accelerates neurologic recovery after cerebral ischemia in a canine model

OBJECTIVE

To evaluate the efficacy of combined therapy--hyperbaric oxygenation with nicardipine administration--for neurologic recovery after complete cerebral ischemia.

DESIGN

Randomized, prospective, controlled, unblinded, study, with 14-day postischemic observation.

SETTING

Laboratory of the Department of Anesthesiology, Tohoku University School of Medicine.

SUBJECTS

Nineteen healthy mongrel dogs (mean weight 10.4 kg) divided randomly into two groups-ten dogs in the untreated group and nine dogs in the treated group.

INTERVENTIONS

Fifteen minutes of complete global cerebral ischemia was achieved by occlusion of the ascending aorta and the caval veins. Dogs in the treated group each received a 0.01-mg/kg bolus injection of nicardipine immediately after the reestablishment of circulation, followed by a 0.03-microgram/kg/min continuous infusion of nicardipine for 3 days and hyperbaric oxygen therapy with 3 atmospheres absolute pressures in an FIO2 of 1.0 for 1 hr at 3, 24, and 29 hrs after ischemia. Neurologic recovery was evaluated based on the survival time and rate, the Electroencephalogram (EEG) Score (1 = normal, 5 = isoelectric), and the Neurologic Recovery Score (100 = normal, 0 = brain dead) over a 14-day postischemic period.

MEASUREMENTS AND MAIN RESULTS

Neurologic Recovery Scores of the treated group were always higher than those scores of the untreated group throughout the 14-day period. The best Neurologic Recovery Score was 83.1 +/- 5.3 in the treated group and 46.9 +/- 5.2 in the untreated group (p < .01). The numbers of dogs that recovered to a Neurologic Recovery Score of > 85 (assessed as almost normal) was five of nine in the treated group and none of ten in the untreated group (p < .01). Recovery of EEG over 14-day period was better in the treated group. The survival rate and the predicted survival rate were 78% and 13.6 days in the treated group and 30% and 9.0 days in the untreated group, respectively (p < .04 for the survival rate and p < .05 for the survival time).

CONCLUSION

Combined therapy, using hyperbaric oxygenation with nicardipine administration, given after 15 mins of complete global cerebral ischemia, accelerates neurologic recovery in dogs.

Axon ramification following unilateral cortical ablation in neonatal rats

We confirmed the formation of an aberrant ipsilateral corticospinal tract after unilateral cerebral cortical ablation during the neonatal period in rat. This tract was studied using anterograde horseradish peroxidase (HRP) tracing. Ramifications of the axons in the pyramidal tract were found to contribute to the ipsilateral tract at the level of the pyramidal decussation, suggesting that ramification of immature axons play an important role in the formation of the ipsilateral corticospinal tract.

Usefulness of argyrophilic nucleolar organizer staining for predicting prognosis of patients with recurrent soft tissue sarcoma

Local recurrence of tumor is a common phenomenon in soft tissue sarcoma (STS) and may be accompanied by an increase in malignant potential. In the present study, an increase of proliferative activity in recurrent tumors compared to primary tumors was observed using a silver stain for nucleolar organizer regions (AgNOR), and its implication for predicting prognosis is assessed. 44 patients with STS showing local tumor recurrence were selected. Local recurrence was defined as new tumor growth more than 2 months after the initial surgery in the same region where the primary tumor occurred. All patients received surgery, followed in 11 patients by adjuvant radiotherapy and/or chemotherapy. The histologic subtype was malignant fibrous histiocytoma in 22 cases, synovial sarcoma in 5, leiomyosarcoma in 4, liposarcoma in 3, malignant schwannoma in 3, and others in 7. The interval between initial surgery and local recurrence ranged from 2 to 72 months. No patients changed from one histological subtype to another. Histological changes included an increase in mitosis, cellularity, and sclerosis in 43.2, 31.8, and 27.3%, respectively. The AgNOR count (mean +/- SD) in recurrent tumors (7.22 +/- 2.59) was significantly higher than that in primary tumors (5.58 +/- 2.28; p < 0.0057), clearly showing a tendency for an increase in proliferative activity during recurrence. The 5-year survival rate of patients with a marked increase (> 4) in AgNOR count (16.7%) was worse than with minor to moderate increases (60.0%; p < 0.02). Marked AgNOR increase was more frequently observed in the tumors located in the head and neck and retroperitoneum (40%) than in other sites (9%). Irrespective of the primary site of tumors, a marked AgNOR increase resulted in an unfavorable prognosis. Multivariate analysis of change in histologic factors including AgNOR, cellularity, mitotic counts, pleomorphism, myxoid change, necrosis, sclerosis, and tumor size showed that increase of AgNOR counts was significant (p < 0.05). The present findings suggest that AgNOR counts can be used as a prognostic factor in recurrent STS.

Middle dose rate irradiation in combination with carbogen inhalation selectively and more markedly increases the responses of SCCVII tumors

PURPOSE

Carbogen increases the radiation response of tumors and reduced dose rate irradiation spares the damage of normal tissues. The purpose in this paper is to investigate the possibility of selective radiosensitization of tumors by reduced dose rate irradiation in combination with carbogen inhalation.

METHODS AND MATERIALS

SCCVII tumors in C3H/He mice were irradiated at middle dose rate (0.1 Gy/min) or high dose rate irradiation (3.0 Gy/min) in combination with carbogen inhalation. The mice were enclosed in a box with carbogen flushing at 1.01/min. The tumor response was measured by a cytokinesis block micronucleus assay. The effects on intestinal crypt cells and bone marrow cells were investigated by microcolony assay or Hendry's method, respectively.

RESULTS

The anti-tumor effect of middle dose rate irradiation was equal to that of a high dose rate irradiation. Carbogen inhalation, more efficiently, increased the antitumor effect when combined with middle and high dose rate irradiation, and yielded enhancement ratios of 1.6 at around 2 Gy. Middle dose rate irradiation produced less damage on intestinal crypt cells and bone marrow cells in comparison with high dose rate irradiation, and carbogen inhalation never enhanced the responses of these normal tissues in combination with middle dose rate irradiation. Dose modifying factors were 1.3-2.0.

CONCLUSION

Since middle dose rate irradiation in combination with carbogen inhalation gave the therapeutic gain factors of 2.0-3.2, which were much larger than those obtained with any other radiosensitizers, this combination has a potential as a new modality for improving the results of cancer radiotherapy.

A cooperative randomized controlled study of adjuvant chemoendocrine therapy for breast cancer in Japan

A randomized trial was carried out in 55 Japanese institutions to examine the significance of postoperative adjuvant chemoendocrine therapy in Stages II and IIIA breast cancer patients after radical mastectomy. A total of 619 patients were entered from November 1982 to November 1984, of whom 554 were eligible. Patients were administered MMC (13 mg/m2) after surgery, and were randomized by the envelope method into either group A (ftorafur, 400 mg/m2/day; 275 patients), or group B (ftorafur, 400 mg/m2/day, and tamoxifen, 20 mg/day; 279 patients). Treatment was continued for 1 year from postoperative day 7. There were no significant differences between the two groups with regard to age, menopausal status, ER status, method of operation, stage, or number of positive lymph nodes. There was also no significant difference between the two groups in the 5-year survival and disease-free survival (DFS) rates (Kaplan-Meier method). Stratification by ER status, nodal status, or menopausal status produced no significant differences between the groups. However, postmenopausal patients and lymph node-positive patients who were also ER-positive showed a significantly higher DFS in group B. Furthermore, group B in ER-positive patients with four or more positive lymph nodes also had a higher survival rate.

Simulation of car impact to pedestrian lower extremity: influence of different car-front shapes and dummy parameters on test results

Sled impact tests on mechanical substitutes for a pedestrian were conducted as a preliminary study for the purpose of developing a subsystem test procedure for the assessment of car-front aggressiveness to pedestrian legs. Four mechanical substitutes for a pedestrian were used in the test: the leg of a rotationally symmetrical pedestrian dummy (RSPD) as the representation of a subsystem, a HYBRID-II pedestrian dummy, a modified HYBRID-II pedestrian dummy equipped with a steel bar serving as knee joint, and a RSPD - HYBRID-IIP combined dummy in which the lower part of the RSPD and the upper part of the HYBRID-IIP were connected by a joint in such a way that the movements of the upper part were similar to those in cadaver tests. In the tests the following were evaluated: (i) the influence of vehicle shape on knee response and on vehicle impact force; (ii) the influence of the upper body mass on knee response and on vehicle impact forces; (iii) the influence of the bumper system on knee response, the kinematics of pedestrian mechanical substitute, and on vehicle impact forces; (iv) the influence of pedestrian mechanical substitute characteristics on its kinematics and knee response, and on vehicle impact forces. This paper describes a primary concept when subsystem test methods for the assessment of car-front aggressiveness to pedestrian legs in a car-pedestrian collision are considered.

Background conductance attributable to spontaneous opening of muscarinic K+ channels in rabbit sino-atrial node cells

Single myocytes were dissociated from the rabbit sino-atrial node, and the membrane background conductance produced by spontaneous opening of the muscarinic K+ channels was investigated by recording whole-cell and single channel currents in both normal K+ (5.4 mM) and high-K+ (145 mM) external solutions. Increasing external K+ concentration ([K+]o) from 5.4 to 145 mM induced a large inward shift of the whole-cell current accompanied by considerable current fluctuations at -50 mV. The high-K(+)-induced current was both K+ selective and voltage dependent, which was examined by varying [K+]o. This current was almost completely suppressed by 1-5 mM Ba2+ or 2-10 mM Cs+ and it was partly blocked by 10 microM atropine. In high-K+ (145 mM) solution, 20 nM acetylcholine (ACh) further increased the K+ conductance as well as the current noise. The power density spectrum of the noise was fitted with a sum of two Lorentzian functions. The corner frequencies of both the slow (approximately 5 Hz) and fast (approximately 120 Hz) components were comparable between the noise before and during the ACh application. Internal dialysis with a non-hydrolysable derivative of ATP, 5'-adenylylimido-diphosphate (AMP-PNP) or Mg(2+)-free solution markedly decreased both the amplitude and fluctuations of the high-K(+)-induced current. The relation between the variance of the current fluctuations and the mean current amplitude was linear in every experiment using dialysis of AMP-PNP or Mg(2+)-free internal solution, or using superfusion of ACh. The slopes of these relations gave comparable single channel current amplitudes of -0.7 pA at -50 mV. These results indicate that the spontaneous opening of the muscarinic K+ channels is largely responsible for the high-K(+)-induced current. In the high-K+ solution, the variance-mean relation at -50 mV showed that the muscarinic K+ channel provides an inward current of 3.12 +/- 2.13 pA pF-1 (n = 23), which was about 60% of the total inward background current. In the normal K+ solution, the variance-mean relation at -50 mV indicated that an outward current of 6.0 +/- 2.0 pA (0.33 +/- 0.28 pA pF-1, n = 8) was provided by the K+ channel. The single channel current amplitude was estimated to be 0.06 +/- 0.02 pA (n = 9). Cell-attached recordings in the absence of ACh demonstrated sporadic and brief openings of channels identical to the ACh-induced channels. The power density spectra of the single channel currents exhibited kinetic properties comparable with those of the whole-cell currents.(ABSTRACT TRUNCATED AT 400 WORDS)

Postnatal development of neuropeptide Y- and calcitonin gene-related peptide-immunoreactive nerves in the rat urinary bladder

The postnatal development of neuropeptide Y- and calcitonin gene-related peptide-immunoreactive (NPY-IR and CGRP-IR) nerve fibers in the rat urinary bladder was investigated using whole-mount preparations and cryostat sections. In newborn and 3-day-old rats, many NPY-IR nerve fibers were observed in the subserous and muscle layers. Many NPY-IR nerve cell bodies clustered at branching points of the subserous nerve bundles. Within 4 weeks after birth, these cell bodies drastically decreased in number and spread along the bundles, although the number of NPY-IR nerve fibers increased moderately. In contrast, CGRP-IR nerve fibers in newborn and 3-day-old rats were less developed, and no CGRP-IR nerve cell body was observed in any rat. However, CGRP-IR nerve fiber distribution in the urinary tissues conspicuously increased within 4 weeks after birth. Especially, an increase of the infraepithelial fibers showing a meshwork appearance was prominent in the fundus and corpus of the bladder. The infra- and intraepithelial CGRP-IR nerve meshwork of the ventral wall was more dense than that of the trigone. At 4 weeks, NPY-IR and CGRP-IR nerves were similar to those of the adult rat (8-12 weeks old). The present study suggests a correlation between the development of the peripheral nervous system in the urinary bladder and maturation of micturition behavior in the rat.

Estimation of the initial slope of the cell survival curve after irradiation from micronucleus frequency in cytokinesis-blocked cells

We have already reported that the alpha/beta ratio of the cell survival curve could be estimated from the micronucleus frequency in cytokinesis-blocked cells treated with cytochalasin-B after irradiation. In this paper, we investigate the direct relationship between the alpha value and the appearance of micronuclei. Cells of the SCCVII, RIF-1, EMT6, V-79, CHO, HeLa and human esophageal cancer cell lines were used for the study. Low-dose-rate irradiation was used to determine the alpha component of the relationship between dose and micronucleus frequency according to the linear-quadratic (LQ) model. A reduction of the dose rate from 3.09 to 0.0142 Gy/min correspondingly decreased the micronucleus frequency; however, the fraction of binucleate cells without micronuclei was not affected in SCCVII and RIF-1 cells. When this fraction was defined as the normal nuclear division fraction, it decreased exponentially as a function of radiation dose. Then dose vs normal nuclear division fraction (NNDF) was fitted as follows: -ln NNDF = aD + C, where D is radiation dose in grays and C is constant. The slope of the dose vs normal nuclear division fraction was not affected by dose rate. The correlation was also explored between the slope (a) and the alpha value of the cell survival curve determined by the colony formation assay in cells of eight cell lines. These two values showed extremely high agreement: alpha = 1.01 a + 0.00795 (r = 0.99, P < 0.01). This assay was applied to estimate the alpha value of the cell survival curve of human esophageal cancer cell lines established from surgical specimens.

A histochemical study of the biceps brachii muscle cross-innervated by intercostal nerves. 6 cases of brachial plexus injuries operated with nerve-crossing

Direct nerve-crossing of intercostal nerves from the lateral thorax to the musculocutaneous nerve was performed in 6 patients after spinal nerve root avulsion with brachial plexus palsy. Elbow flexion power was regained well enough to move against gravity and some resistance in all cases. The muscles were examined histochemically 4 (1-9) years after the operation. The intercostally-innervated biceps brachii muscle showed motor predominance of slow-twitch Type 1 fiber regeneration much more than that of fast-twitch Type 2 fiber in 5 of our patients. Our study suggests that the motor nerves of slow-twitch fibers may have priority in peripheral nerve regeneration over those of fast-twitch fibers.

Transfilter bone induction by Chinese hamster ovary (CHO) cells transfected by DNA encoding bone morphogenetic protein-4

This study was undertaken to identify the factor responsible for classical transfilter bone induction by a murine osteosarcoma. Chinese hamster ovary (CHO) cells were transfected with the complementary DNA (cDNA) for bone morphogenetic protein-4 (BMP-4) that was purified from a murine (Dunn) osteosarcoma. Diffusion chambers were filled with the cells expressing the gene for BMP-4 and implanted subcutaneously into the flanks of ICR strain nude mice. Ectopic transfilter bone formation was seen consistently on the outer surfaces of the cellulose acetate membranes of chambers containing transfected cells at three weeks after implantation. Bone was not observed on chambers loaded with nontransfected CHO cells. The transfected CHO cells were inoculated into nude mice to form tumors, which were then homogenized, defatted, and bioassayed also in the ICR, nu/nu mice. The cell-free implants consistently elicited new bone and marrow within three weeks, whereas the control implants consisting of nontransfected tumor were not osteoinductive. These experimental results suggest that BMP-4 is one of the molecules responsible for the transfilter bone induction by vital Dunn osteosarcoma cells reported by Heiple and for the ectopic bone induction after implantation of devitalized, freeze-dried Dunn osteosarcoma tissue described originally by Amitani.

Configuration of myoepithelial cells in various exocrine glands of guinea pigs

To study the configuration of myoepithelial cells, we isolated glandular endpieces of various guinea pig glands by collagenase, and visualized the myoepithelial cells by immunohistochemistry for actin, or by Bodipy-phallacidin, under both a light microscope and laser scanning confocal microscopes. In parotid and mandibular glands, the glandular acini were small (about 20-30 microns diameter) and spherical, and each acinus had one or two myoepithelial cells attached that were stellate in shape (central cell body and four to six thin processes). Most of the basal surface of the glandular cells was not covered by myoepithelial cells, and processes often extended to the neighboring acinus. The tubular glandular endpieces of the major sublingual gland, which secretes a mucous substance, were almost fully encircled by band-like myoepithelial cells (about 3-6 microns wide). Although there were many differences between the lacrimal gland and the Harderian gland (e.g., the secretory product of the lacrimal gland was mucous, and glandular lumina were narrow; the Harderian gland secreted lipids and showed wide lumina), the outer contours of both glandular endpieces were the same (about 50-100 microns diameter, ellipsoid or spherical in shape). In both glands, 5-20 stellate myoepithelial cells were attached onto a glandular endpiece, and their arrangement had a lacy appearance. Actin filaments in myoepithelial cells aggregated and formed bundles in the broad processes and cell bodies. The bundles ran across the cell body, but there was no point where the bundles converged. In the arborization, some distal processes reversed their direction. We conclude that the configuration of myoepithelial cells depends on the outer contour of the glandular endpieces rather than on the secretory material or luminal width. The variety of myoepithelial cell configurations in the different exocrine glands we examined suggests that it is quite difficult to assign to myoepithelial cells the general role of expelling secretory products from glandular lumina. These cells seem to maintain the contour of the glandular endpieces, serving as the exoskeleton of the endpieces.

Cloning and expression of cDNA coding for a new allergen from the house dust mite, Dermatophagoides farinae: homology with human heat shock cognate proteins in the heat shock protein 70 family

An immunoreactive clone, which shares no homology with the major allergens, Der f I and Der f II, was isolated by screening of a Dermatophagoides farinae cDNA library with rabbit antiserum raised against an extract of the house dust mite and sera from patients with mite allergy. The deduced amino acid sequence of the cDNA of the clone is significantly homologous, up to 65.5%, to the carboxyl-terminal region of the heat shock cognate protein (hsc) 71 in the heat shock protein (hsp) 70 family. A pool of the recombinant protein-specific IgE purified from mite-allergic sera recognized a 67 kDa protein on a blot of ATP-binding components partially purified from the mite body extract, while the antibody did not bind to the major allergens. We conclude that the recombinant protein, one of several important allergens, may be a protein in the heat shock protein 70 family from the house dust mite, D. farinae.

Ganglion cells immunoreactive for catecholamine-synthesizing enzymes, neuropeptide Y and vasoactive intestinal polypeptide in the rat adrenal gland

Immunohistochemistry has been used to demonstrate tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH), phenylethanolamine N-methyltransferase (PNMT), neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) immunoreactivities, and acetylcholinesterase (AChE) activity was demonstrated in rat adrenal glands. The TH, DBH, NPY and VIP immunoreactivities and AChE activity were observed in both the large ganglion cells and the small chromaffin cells whereas PNMT immunoreactivity was found only in chromaffin cells, and not in ganglion cells. Most intra-adrenal ganglion cells showed NPY immunoreactivity and a few were VIP immunoreactive. Numerous NPY-immunoreactive ganglion cells were also immunoreactive for TH and DBH; these cells were localized as single cells or groups of several cells in the adrenal cortex and medulla. Use of serial sections, or double and triple staining techniques, showed that all TH- and DBH-immunoreactive ganglion cells also showed NPY immunoreactivity, whereas some NPY-immunoreactive ganglion cells were TH and DBH immunonegative. NPY-immunoreactive ganglion cells showed no VIP immunoreactivity. AChE activity was seen in VIP-immunopositive and VIP-immunonegative ganglion cells. These results suggest that ganglion cells containing noradrenaline and NPY, or NPY only, or VIP and acetylcholine occur in the rat adrenal gland; they may project within the adrenal gland or to other target organs. TH, DBH, NPY, and VIP were colocalized in numerous immunoreactive nerve fibres, which were distributed in the superficial adrenal cortex, while TH-, DBH- and NPY-immunoreactive ganglion cells and nerve fibres were different from VIP-immunoreactive ganglion cells and nerve fibres in the medulla. This suggests that the immunoreactive nerve fibres in the superficial cortex may be mainly extrinsic in origin and may be different from those in the medulla.

Ectopic ossification associated with osteoid osteoma in the acetabulum. A case report

Ectopic bone formation was associated with osteoid osteoma in the anterior rim of the acetabulum. A factor, which has been speculated to be secreted from the nidus and is responsible for increased osteoblastic activity, also seemed to have the capacity to stimulate young mesenchymal cells to differentiate into an osteogenic pathway. A case of a 35-year-old woman with osteoid osteoma, which caused ectopic ossification adjacent to the nidus, is presented.

The effect of CO2-induced acid-base changes on the potencies of muscle relaxants and antagonism of neuromuscular block by neostigmine in rat in vitro

We investigated the influence of CO2-induced acid-base changes on the potencies of the monoquaternary relaxants (rocuronium, vecuronium, and d-tubocurarine) and bisquaternary relaxants (pancuronium, pipecuronium, and metocurine), and on the antagonism of their neuromuscular block by neostigmine. Phrenic nerve-hemidiaphragm preparations of rats were used. The pH changes were induced by changing the CO2 concentration aerating the modified Krebs solution. The potencies of the monoquaternary relaxants increased at 9% CO2 (pH 7.2) and decreased at 2.5% CO2 (pH 7.6) from those of 5% CO2 (pH 7.4) both with and without neostigmine (P < 0.05), whereas the potencies of the bisquaternary drugs did not change significantly at different pH levels from control (pH 7.4) both with and without neostigmine. The slopes of the log concentration-percent response curves of each drug were not significantly different at each pH level. The ratios of inhibitory concentrations, 50% (IC50) values with and without neostigmine at each pH value for each drug were not significantly different indicating that the neostigmine-induced antagonism for each drug was not affected by the CO2-induced acid-base changes. But the ratios of the IC50 values of the steroidal relaxants (rocuronium, vecuronium, pancuronium, and pipecuronium) were significantly lower (P < 0.05) than those of the isoquinolinium drugs (d-tubocurarine and metocurine) at each pH level, suggesting that the antagonism is enhanced at each pH level for the isoquinolinium relaxants. The difference was independent of their monoquaternary or bisquaternary nature. These results suggest that CO2 increases the potency of the monoquaternary relaxants but does not affect the bisquaternary relaxants.(ABSTRACT TRUNCATED AT 250 WORDS)

Limited diffusibility of gene products directed by a single nucleus in the cytoplasm of multinucleated myofibres

Two types of beta-galactosidase genes, whose products are distributed in the nucleus (N beta-gal) or cytoplasm (C beta-gal), were injected with fructose intramuscularly into the quadriceps of adult mice. Regionally restricted and overlapped distributions of both gene products were observed in the myofibres. These findings indicate that N beta-gal is incorporated into the nucleus responsible for its synthesis and that C beta-gal becomes located in the vicinity of the nucleus after its synthesis. This restricted location of C beta-gal in myofibres remained unchanged during the development of infant mouse muscle. Thus, the gene products directed by the nucleus of myofibres seem to show limited diffusibility, suggesting a universal localization of subcellular domains in myofibres.