Distinct p53-mediated G1/S checkpoint responses in two NIH3T3 subclone cells following treatment with DNA-damaging agents

N3T3 and P-3T3 cells, originally isolated from a NIH3T3 cell clone on the basis of their negative and positive transformation by v-Abl, v-Src and Bcr-Abl, were previously found to show distinct cyclin activity changes following 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment, which is anti-mitogenic for N-3T3 cells and mitogenic for P-3T3 cells. We have found in this study that, while the G1/S arrest and cell death induced by serum starvation and TPA treatment in N-3T3 cells did not involve p53-mediated checkpoint or apoptosis, N-3T3 and P-3T3 cells evidently responded differently in these aspects of cell cycle regulation to DNA-damaging agents, methylmethane sulfonate (MMS) and gamma-radiation. In N-3T3 cells, DNA damages elicit cell growth arrest at G1/S transition with concomitant accumulation of p53 and p53-inducible Waf1/Cip1 proteins and also signs of apoptosis such as DNA ladder patterns and apoptotic (subgenomic) peak in flow cytograph. Conversely, P-3T3 cells treated with the DNA-damaging agents showed no cell cycle interruption nor accumulation of p53 or Waf1/Cip1. However, both P-3T3 and N-3T3 cells showed the same p53 protein half-life of 40 min or less, the same wild-type p53 DNA sequence and the same co-immunoprecipitable cellular proteins in complexes with p53, suggesting that an alteration in a signal transduction pathway upstream of p53 might account for the evasion of p53-mediated G1 checkpoint in P-3T3 cells.

Evaluation of polymerase chain reaction-restriction enzyme analysis of mycobacteria cultured in BACTEC 12B bottles

Polymerase chain reaction with restriction enzyme analysis (PRA) was first tested on 15 reference strains and 50 subcultured clinical isolates of mycobacteria according to the reference algorithm by Telenti et al [1]. Next, we evaluated the application of this method to 108 isolates from liquid media (BACTEC 12B). Of them, 15 M. tuberculosis complex and 81 mycobacteria other than tuberculosis (MOTT) had comparable results with both PRA and the BACTEC 460 TB systems. However, seven M. tuberculosis complex and three potentially pathogenic MOTT were identified by PRA rather than the BACTEC TB system. PRA seems to be an efficient method for the identification of mycobacteria to the species level and a good aid to detect potentially pathogenic mycobacteria, especially in mixed mycobacterial cultures.

The hypothalamus-pituitary-ovary and hypothalamus-pituitary-thyroid axes in spinal cord-injured women

Sixteen women with spinal cord injury (SCI) underwent studies of the hypothalamus-pituitary-ovary (HPO) and hypothalamus-pituitary-thyroid (HPT) axes with luteinizing hormone (LH) releasing hormone (LHRH) and thyrotropin (TSH) releasing hormone (TRH) stimulation tests during the early follicular phase. The mean interval from injury to participation in this study was 7.5 years (range, 1.5 to 13.1). All subjects were menstruating regularly. Five (35.7%) SCI subjects who were menstruating before injury had postinjury amenorrhea for 1 to 12 months, and the other nine (64.3%) SCI subjects had no interruption of menstruation after injury. Two SCI subjects whose injury occurred in preadolescence proceeded to menarche without any delay. The amount of menstrual flow was noted to be reduced in nine (64.3%) SCI subjects. Two and three SCI subjects had elevated follicle-stimulating hormone (FSH) and prolactin (PRL) levels, respectively. LH responses to LHRH were significantly higher in the SCI group (P < .001). Ten (62.6%) SCI subjects had enhanced LH responses to LHRH. The mean TSH, PRL, and FSH responses to TRH and LHRH of the SCI group were not significantly different from those of age-matched controls. However, five (31.2%), four (25.0%), and five (31.2%) SCI subjects had enhanced TSH, PRL, and FSH responses to TRH and LHRH, respectively. Six (37.5%) SCI subjects had a delayed FSH response to LHRH. In total, 13 (81.2%) SCI subjects had at least one axis abnormality. These findings are consistent with the hypothesis that changes of central neurotransmitters may occur after SCI.

Purification and cDNA cloning of ferritin from the hepatopancreas of the freshwater crayfish Pacifastacus leniusculus

Ferritin was purified from the hepatopancreas of the freshwater crayfish Pacifastacus leniusculus after injection of iron. It has the same size as horse spleen ferritin (440 kDa) and migrates as two bands, 19 kDa and 20 kDa, respectively, in SDS/PAGE under reducing conditions. Crayfish ferritin (20 kDa) was cloned from a hepatopancreas cDNA library. The deduced amino acid sequence of the crayfish ferritin shows a closer relationship to vertebrate ferritin heavy chains than to insect ferritin and contains the conserved H-specific residues for the ferroxidase centre found in vertebrate ferritin heavy chain. An IRE(iron-responsive element)-like sequence with a predicted stem-loop structure was present in the 5' untranslated region of the crayfish ferritin mRNA. Crayfish ferritin does not share the atypical properties of insect ferritins, such as high molecular mass of intact protein, abundance in hemolymph, and export into vacuoles. We suggest that there are two different types of ferritins distributed in different species: insect-type or secretory ferritins which are predominant in the snail oocyte and insects, and vertebrate (crustacean)-type or cytosolic ferritins which are predominant in vertebrates and crustacea.

Optimal edge detection in two-dimensional images

This paper presents a new edge detection scheme that detects two-dimensional (2-D) edges by a curve-segment-based detection functional guided by the zero-crossing contours of the Laplacian-of-Gaussian (LOG) to approach the true edge locations. The detection functional is shown to be optimal in terms of signal-to-noise ratio (SNR) and edge localization accuracy; it also preserves the nice scaling property held uniquely by the LOG in scale space.

Algebraic methods for image processing and computer vision

Many important problems in image processing and computer vision can be formulated as the solution of a system of simultaneous polynomial equations. Crucial issues include the uniqueness of solution and the number of solutions (if not unique), and how to find numerically all the solutions. The goal of this paper is to introduce to engineers and scientists some mathematical tools from algebraic geometry which are very useful in resolving these issues. Three-dimensional motion/structure estimation is used as the context. However, these tools should also be helpful in other areas including surface intersection in computer-aided design, and inverse position problems in kinematics/robotics. The tools to be described are Bezout numbers, Grobner bases, homotopy methods, and a powerful theorem which states that under rather general conditions one can draw general conclusions on the number of solutions of a polynomial system from a single numerical example.

Artifact reduction in low bit rate DCT-based image compression

This correspondence presents a scheme for artifact reduction of low bit rate discrete-cosine-transform-compressed (DCT-compressed) images. First, the DC coefficients are calibrated using gradient continuity constraints. Then, an improved Huber-Markov-random-field-based (HMRF-based) smoothing is applied. The constrained optimization is implemented by the iterative conditional mode (ICM). Final reconstructions of typical images with improvements in both visual quality and peak signal-to-noise ratio (PSNR) are also shown.

Nucleus 22-channel cochlear mini-system implantations in Mandarin-speaking patients

This article evaluates the benefits of the Mini System of the Nucleus 22-Channel Cochlear Implant on the speech perception and auditory functions of Mandarin-speaking patients. Tests adapted specifically for the assessment of a tonal language were administered in the best-aided condition preoperatively to four Mandarin-speakers. These scores were compared postoperatively with implant alone or with lipreading scores to quantify speech perception and auditory improvements resulting from the Nucleus 22 Mini-System cochlear implant. Four postlingually deafened adults underwent cochlear implant surgery using a Nucleus 22-Channel Mini-System Device via an inverted "U" postauricular incision and the posterior tympanotomy approach, without complications. After up to 2 years of rehabilitation, all four patients exhibited continuous improvement in both speech perception and auditory abilities over time. The improvements made by our Mandarin-speaking patients are comparable to studies on Western-language-speaking patients implanted with the same device, indicating that the Nucleus 22 Mini System enables profoundly and totally deaf patients to distinguish between the four separate tones present in Mandarin Chinese.

Protease-susceptible sites and properties of fragments of aortic smooth-muscle myosin

We have examined the protease susceptibility of aortic myosin, the thermal unfolding profiles of myosin rod and light meromyosin (LMM) and the solubility properties of the LMM fragments. Two major protease-susceptible sites were found, located at the head-rod junction and the heavy meromyosin (HMM)-LMM junction. Both tryptic and chymotryptic digestion of aortic myosin rod produced the LMM (80-85 kDa) and short subfragment 2 (S-2) (40-45 kDa) segments, which were similar to those of gizzard myosin rod and differed from the short LMM (70 kDa) and long S-2 (58 kDa) segments produced from skeletal-muscle rod. The thermal unfolding profile of aortic myosin rods exhibited three helix-unfolding transitions, at 47.5, 51 and 54 degrees C, similar to those of gizzard rods yet different from those of skeletal-muscle rods. There was a dramatic difference in the solubility of aortic LMM fragments of various molecular mass, as for gizzard smooth-muscle LMM and rabbit skeletal-muscle LMM. LMM fragments of molecular mass 77 kDa or more were completely insoluble in low-ionic-strength buffer, whereas LMM fragments of molecular mass 73 kDa or less were completely soluble in low-ionic-strength buffer. Proteolytic digestion patterns of LMM showed two additional protease-susceptible sites located 13 and 30 kDa from the ends of the LMM molecule. This suggests the existence of flexible regions within the LMM molecule, which may be responsible for the folded form of aortic myosin.

Mutagenicity and toxicity studies of p-phenylenediamine and its derivatives

The mutagenicity of p-phenylenediamine and its derivatives was tested using Ames Salmonella strains TA98 and TA100. p-Phenylenediamine was weakly mutagenic to TA98 with metabolic activation. 2-Nitro-p-phenylenediamine was directly mutagenic to both strains, while 2-methyl-p-phenylenediamine required S9 mix. All the test compounds induced a dose-related increase in chromosomal aberrations in Chinese hamster ovary (CHO) cells in the absence of the S9 mix. The mutagenicity and toxicity of these compounds did not correlate with their oxidation potentials, or any other tested physicochemical properties including the energy difference between the lowest unoccupied and the highest occupied molecular orbital, ionization potential, and dipole moment.

Preferential requirement for protein tyrosine phosphatase activity in the 12-O-tetradecanoylphorbol-13-acetate-induced differentiation of human colon cancer cells

Some lines of colon cancer cells are forced to undergo differentiation by 12-O-tetradecanoylphorbol-13-acetate (TPA). The increases in activities of both protein tyrosine phosphatase (PTP) and protein tyrosine kinase (PTK) have been reported to be associated with the TPA-induced differentiation of HL-60 leukemia cells. In the present study, a 2-fold increase in PTP activity was observed in SW620 human colon cancer cells after 30 min of TPA treatment; a maximal level (4- to 5-fold) was reached at 60 min and continued for more than 6 hr. In addition, two TPA-induced differentiated characteristics, morphological alteration and release of cellular surface proteoglycan, were effectively blocked by PTP inhibitors, such as sodium orthovanadate (50 microM), zinc chloride (100 microM), and iodoacetate (250 microM), but not by the protein serine/threonine phosphatase inhibitor okadaic acid (20 nM). On the other hand, although TPA induced a transient slight increase in PTK activity (1.4-fold) at 60 min, four PTK inhibitors (genistein, herbimycin A, tyrphostin-23 and quercetin) had different effects on the TPA-induced release of cell surface proteoglycan. Genistein (60 microM) potentiated this process, but in contrast, quercetin (45 microM) could partially inhibit the TPA effect. Taken together, these observations suggest that both PTP and PTK activities were increased in SW620 cells in response to TPA; however, the activation of PTP seems to be preferentially required for the TPA-induced differentiation of SW620 human colon cancer cells.

Effect of triiodothyronine administration in experimental myocardial injury

Twelve healthy pigs were subjected to a 20-min, period of regional myocardial ischemia by snaring the left anterior descending coronary artery (LAD) between its first and second diagonal branches. The resulting myocardial injury caused significant acute hemodynamic impairments. Cardiac index declined significantly during reperfusion interval and returned to preischemic level by postoperative day 7. Plasma total triiodothyronine (TT3), free triiodothyronine (FT3) and free fatty acid (FFA) decreased gradually and reached the nadir at 6 h after LAD occlusion. In contrast, plasma reverse triiodothyronine (rT3) increased progressively after LAD occlusion and reperfusion. To investigate the effect of T3 on ischemic myocardium, T3 (0.2 microgram/kg/dose; n = 5) or saline (placebo; n = 6) was administered immediately, 30 min, 60 min, 90 min, and 120 min after reperfusion. Plasma TT3 and FT3 increased dramatically after triiodothyronine supplement but declined to presichemic level at six h after LAD occlusion. The pigs treated with T3 demonstrated a rapid improvement in cardiac index over the reperfusion interval, whereas cardiac index in the placebo group remained depressed. Myocardial oxygen consumption estimated by rate pressure product showed no difference between placebo and T3-treated groups. Oxygen extraction as O2 saturation difference between aorta and coronary sinus was less in T3-treated group. Nine pigs (four in the T3-treated group and five in the placebo group) were subjected to euthanasia with hypertonic KCl solution on postoperative day 7. Myocardial infarct size determined by triphenyltetrazolium chloride (TTC) tissue enzyme staining technique was not significantly different between T3-treated and placebo groups. We concluded that this animal model is a useful model of myocardial injury simulating "euthyroid sick syndrome" as seen in patients with cardiopulmonary bypass, and T3 supplementation after reperfusion significantly enhanced postischemic left ventricular functional recovery but did not affect myocardial oxygen consumption and myocardial infarct size.

A labile hyperphosphorylated c-Fos protein is induced in mouse fibroblast cells treated with a combination of phorbol ester and anti-tumor promoter curcumin

Curcumin is a potent inhibitor of tumor promotion, and was shown previously to inhibit 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced AP-1 activity. The c-Fos protein is inducible by TPA and thus is associated with c-Jun to result in an increased AP-1 activity in mouse fibroblast cells. We therefore hypothesized that c-Fos may be one of the targets of curcumin action. In the present study, the effects of curcumin on TPA-induced c-fos mRNA and protein levels were determined by RNA hybridization and western blot analysis, respectively. Curcumin decreases the TPA-induced nuclear abundance of c-Fos protein in spite of the slight super-induction of c-fos mRNA. Upon TPA stimulation, the amount of c-Fos in the quiescent cells increases and reaches maximum at 30 min, and then progressively disappears over a period of 60 min. However, the c-Fos protein seems susceptible to rapid degradation by 45 min if NIH 3T3 cells were treated with TPA in the presence of curcumin. The curcumin-induced hyperphosphorylated forms of c-Fos proteins are significantly more unstable; they entirely disappeared within 40 min after incubation at 37 degrees C. These findings prompted us to suggest that the decrease of c-Fos protein could account for the repressed in vitro DNA binding probably by reducing the Jun/Fos complex formation.

Retrieval of a pin from the airway: a case report

Inhalation of foreign body in children is extremely hazardous, since the caliber of the tracheobronchial tree is small in children and the technique of bronchoscopic extraction is very demanding. The problem is even more complicated in handling rare foreign bodies, since the bronchoscopic procedure may be prolonged and inaccurate. Presented here is a case of pin aspiration. The long and pointed pin is quite impossible to remove. In this article, the course of bronchoscopy removal of the pin was described and the technical aspects of rigid bronchoscopy in handling pointed objects were cited in detail.

Suppression of the hypothalamus-pituitary somatotrope axis in men with spinal cord injuries

Thirty-two men with spinal cord injury (SCI) were studied for evaluation of the hypothalamus-pituitary somatotrope axis, using growth hormone-(GH)-releasing hormone (GHRH) and insulin-induced hypoglycemia. Twenty-six age-matched normal male volunteers served as controls. Six SCI subjects (18.7%) had elevated basal follicle-stimulating hormone (FSH) levels, eight (25.0%) had hyperprolactinemia, and 11 (34.4%) had reduced serum insulin-like growth factor-1 (IGF-1) levels. Twenty SCI subjects (62.5%) had reduced and/or delayed GH responses to GHRH, and eight (25.8%) had reduced GH response to insulin-induced hypoglycemia. Seven of eight hyperprolactinemic SCI subjects showed reduced GH response to GHRH and/or insulin-induced hypoglycemia. These findings are consistent with the notion that SCI subjects have a reduced central dopaminergic tone.

Tone perception of Mandarin-speaking postlingually deaf implantees using the Nucleus 22-Channel Cochlear Mini System

Because Mandarin Chinese is a tonal language, testing the patient's ability to distinguish among four tones is of paramount importance. This paper evaluates the efficacy of the Nucleus 22-Channel Mini System for Mandarin Chinese by comparing the postoperative tone perception test results with the results of the closed-set monosyllable, trochee, and spondee (MTS) test, and the open-set phonetically balanced (PB) word and sentence comprehension tests, which also incorporate tonal features, for eight Mandarin-speaking postlingually deaf patients implanted with this device. Except for one patient, the data clearly indicate that patients who had increased scores on tone perception after implantation also had improvements on other test batteries. Results also substantiate our previous observation that the Nucleus 22-channel cochlear implant enables profoundly and totally deaf patients to distinguish four separate tones in Mandarin Chinese. This would seem to support our earlier speculation that the acoustic cues of fundamental frequency of the four Mandarin tones are extracted by the Multipeak coding strategy of the 22-channel device and transferred to the cochlea, where they are perceived as rate pitch.

Pronounced activation of protein kinase C, ornithine decarboxylase and c-jun proto-oncogene by paraquat-generated active oxygen species in WI-38 human lung cells

Paraquat (methyl viologen, PQ) is a widely used herbicide that produces oxygen-derived free radicals and severely injures human lungs. In this study we examined the effects of PQ on the protein kinase C (PKC), ornithine decarboxylase (ODC) and c-jun oncogene expression in WI-38 human lung cells. Exposure of cells to 25-200 microM PQ resulted in an increase of [3H]phorbol dibutyrate (PDBu) binding and PKC redistribution in a dose-dependent manner. Interestingly, a superoxide dismutase mimic, 4-hydroxyl-2,2,6,6-tetramethyl-piperidine-1-oxyl (Tempol, 2.5 mM) and catalase (400 micrograms/ml) could significantly reduce the PQ-stimulated increase of phorbol ester binding and particular PKC phosphorylating activity, but dimethylsulfoxide (DMSO, 1.5%), an effective .OH trapping agent, failed to prevent this stimulation. In addition, an endogenous substrate of PKC, 80 kDa protein, was found to be highly phosphorylated in intact WI-38 cells treated with 50 microM PQ. The increase of phosphorylated proteins could be completely or partly abolished by Tempol or catalase, but only the phosphorylation of 80 kDa protein was diminished by protein kinase C inhibitor, 1-(5-isoquinolinyl-sulfonyl)-2-methylpiperazine (H-7). A maximal peak of ODC activity was observed at 6 h of treatment with 50 microM PQ. PQ induced activity was reduced at the following rates, Tempol 85%, DMSO 80% and catalase 45%, but H-7 failed to do so. Furthermore, we found that the level of c-jun mRNA was transiently increased by PQ and the peak appeared at 1 h of treatment. When correlated with the PKC result, Tempol, catalase and H-7 all effectively blocked PQ-elicited c-jun transcript expression, but DMSO only exhibited a weakly inhibitory effect. We therefore propose that superoxide anion (O2- and H2O2 generated by PQ could activate PKC and lead to induction of c-jun gene expression; on the other hand, O2- and .OH might trigger other kinase pathways to elevate ODC activity. Finally, the sequential expression of c-jun oncogene and ODC may cooperate to relieve the oxidative damages elicited by PQ.

Growth and Survival of Salmonella montevideo on Tomatoes and Disinfection with Chlorinated Water

The survival on tomato fruits ( Lycopersicum esculentum ) of a rifampicin-resistant strain of Salmonella montevideo (Centers for Disease Control and Prevention [CDC] isolate G4639), the alleged source of the 1993 multistate outbreak of salmonellosis, was affected by inoculum dose and inoculation site (unbroken surface or wounds and stem scars), as well as by the medium (distilled water, Butterfield's buffer, or trypticase soy broth [TSB]) used to deliver the bacterium, This bacterium inoculated at 4 log₁₀ CFU (colony forming units) per site in distilled water survived for 20 h on tomato skin. However, comparable survival occurred at the stem scars and growth cracks with smaller inoculum doses (3 log₁₀ CFU). The bacterial populations increased rapidly on puncture wounds and tomato slices but decreased on the unbroken surface and stem scar. With unbroken skin and approximately 4 log₁₀ CFU per site, the population survived for at least 48 h but could not be consistently detected after 5 days. By contrast, the stem scar population survived for at least 7 days and decreased only 1 to 2 log₁₀ units. The inherently low pH of the tomatoes did not inhibit bacterial growth. Treatment with 100 ppm of aqueous chlorine for up to 2 min failed to kill all bacteria at these inoculation sites. This was especially true when the bacterial suspensions were prepared in TSB. TSB supported better bacterial survival and/or growth and also protected against the bactericidal effect of aqueous chlorine.

Brain Abscess: With Special Reference to Otolaryngologic Sources of Infection

The number of brain abscesses has been reduced since the preantibiotic era. This was accomplished by judicious use of antibiotics, by the advent of computed tomography, and by improvements in patient care and surgical techniques. Analysis from 122 patients with brain abscess demonstrated this trend of progress. Our series had a 3.2-to-1 male predominance. The underlying conditions included otolaryngologic infections (26 cases), cyanotic heart diseases (27 cases), implantation abscess (25 cases), lung infections (5 cases), meningitis (4 cases), osteomyelitis (2 cases), decreased immunity from chronic systemic diseases (12 cases), and unknown causes (21 cases). Otolaryngologic subgroups can be detailed as chronic otitis media with cholesteatoma (15 cases), chronic otitis media with mastoiditis (4 cases), sinusitis (2 cases), esophageal stenosis (3 cases), cheek cellulitis (1 case), and nasopharyngeal carcinoma (1 case). The initial symptoms and signs were headache (46 cases), fever (36 cases), altered consciousness (30 cases), neurologic deficits (33 cases), vomiting (11 cases), and seizure (17 cases). Of the brain abscesses treated, multiple brain abscess represented 16.4% of all cases. The overall percentage of patients with full recovery was 52.5%, whereas 84.8% of otolaryngologic subgroup recovered fully. The overall mortality was 19.7%. The mortality rate of brain abscess from otolaryngologic sources was 3.8%, whereas that from nonotolaryngologic sources was 24%.

Brain abscess: with special reference to otolaryngologic sources of infection

The number of brain abscesses has been reduced since the preantibiotic era. This was accomplished by judicious use of antibiotics, by the advent of computed tomography, and by improvements in patient care and surgical techniques. Analysis from 122 patients with brain abscess demonstrated this trend of progress. Our series had a 3.2-to-1 male predominance. The underlying conditions included otolaryngologic infections (26 cases), cyanotic heart diseases (27 cases), implantation abscess (25 cases), lung infections (5 cases), meningitis (4 cases), osteomyelitis (2 cases), decreased immunity from chronic systemic diseases (12 cases), and unknown causes (21 cases). Otolaryngologic subgroups can be detailed as chronic otitis media with cholesteatoma (15 cases), chronic otitis media with mastoiditis (4 cases), sinusitis (2 cases), esophageal stenosis (3 cases), cheek cellulitis (1 case), and nasopharyngeal carcinoma (1 case). The initial symptoms and signs were headache (46 cases), fever (36 cases), altered consciousness (30 cases), neurologic deficits (33 cases), vomiting (11 cases), and seizure (17 cases). Of the brain abscesses treated, multiple brain abscess represented 16.4% of all cases. The overall percentage of patients with full recovery was 52.5%, whereas 84.8% of otolaryngologic subgroup recovered fully. The overall mortality was 19.7%. The mortality rate of brain abscess from otolaryngologic sources was 3.8%, whereas that from nonotolaryngologic sources was 24%.

Biological response to phorbol ester determined by alternative G1 pathways

A plethora of extracellular signals is known to induce a common set of immediate early genes. The immediate early response, therefore, must not be sufficient to determine the biological outcome. An example of this is found with the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA). A potent activator of protein kinase C, TPA can either stimulate or inhibit cell proliferation, depending on the cell type. This cell context-dependent response to TPA is observed with two subclones of NIH 3T3 cells, the P- and the N-3T3 clones. TPA is a mitogen for the P-3T3 but an antimitogen for the N-3T3 cells. The immediate early pathway is activated by TPA in both cell types, indicating that this pathway alone does not activate DNA synthesis. The delayed induction of cyclin D1 expression by TPA is observed only in the P-3T3 cells, correlating with mitogenesis. N-Acetylcysteine does not affect the immediate early pathway but can inhibit the TPA-mediated induction of cyclin D1 and DNA synthesis. In the N-3T3 cells, TPA causes an inhibition of the cyclin E-associated kinase at the G1/S transition, correlating with growth inhibition. The growth-inhibitory activity of TPA is not affected by N-acetylcysteine. Thus, the two TPA-regulated G1 pathways can be distinguished by their sensitivity to N-acetylcysteine. These results demonstrate that TPA can activate alternative G1 pathways. Moreover, the selection of the alternative G1 pathways is determined by the cell context, which, in turn, dictates the biological response to TPA.

Streptococcal toxic shock syndrome in southern Taiwan

This report outlines our experience with streptococcal toxic shock syndrome (STSS) at the Veterans General Hospital-Kaohsiung during the period October 1990 to November 1993. Group A streptococci were isolated from blood or normally sterile tissue in association with hypotension and multi-organ failure in the eight cases studied. A primary focus of infection was identified in seven cases, including pneumonia (1), septic arthritis (1) and soft-tissue infections (5). The remaining patient suffered from hyperglycemic hyperosmolar non-ketotic coma and Group A streptococcal bacteremia, without an obvious focus of infection. There were four cases of bacteremia. Clinical complications included acute renal failure in all eight cases, disseminated intravascular coagulation in five cases, liver involvement in two cases, adult respiratory distress syndrome in one case and soft-tissue necrosis in five cases. All isolates were sensitive to penicillin, and most patients were treated with intravenous penicillin G, with or without other antibiotics (gentamicin or clindamycin). Of the six patients with soft-tissue infection, two underwent amputation of the infected limb, and one patient underwent sono-guided pigtail drainage of psoas muscle abscess. Three of the patients died. STSS may be uncommon in Taiwan, but it is not rare. Early recognition of STSS (facilitated by Gram stain and culture), prompt debridement and drainage, and adequate antibiotic treatment with penicillin or clindamycin, or both, are necessary for control of such lethal infections.

Pulmonary embolism presenting as syncope in paraplegia: a case report

Syncope as an initial presentation of pulmonary embolism is unusual. A 16-year-old girl, with T7 paraplegia after a traumatic spinal cord injury, developed syncope on the 33rd hospital day. The episode occurred approximately 3 hours after her first tilting table training and just after her attendant had assisted passive range-of-motion exercise. Subsequent studies showed pulmonary embolism at the left lower branch of the left pulmonary artery, and the branch to lower segment of the lingual lobe. Doctors should be alert to possible diagnosis of pulmonary embolism in such high-risk patients, especially when new onset symptoms or signs appear.

Tissue distribution of absorbed humic acids

Distribution of humic acids (HA) in rats was studied using radioiodinated HA injected intraperitoneally. Distribution of (125)I was also studied for comparison. The distribution pattern of HA differed greatly from that of (125)I. Except in the thyroid and skin, (125)I was excreted from the body within 24 hours, whereas a large proportion of HA remained in the liver, kidney, skin, thyroid, bone and muscle. The difference in the distribution pattern and organ/serum radioactivity ratio suggests different kinetics for (125)I and (125)I-HA. The distribution pattern of HA correlated very well with the increased prevalences of organ diseases in the blackfoot disease endemic area, as reflected in epidemiologic studies. It is hypothesised that HA-metal complexes are possible etiological factors of diseases such as goitre, hepatoma, bladder cancer, vascular disease and diabetes mellitus, and that free radicals are the common causative factor.