Photodynamic therapy: applications in bladder cancer and other malignancies

Photodynamic therapy (PDT) has gained popularity in the past 10 years because of advances in laser and pharmacokinetic technologies and the development of new photosensitizers. Early studies on PDT with focal illumination for papillary bladder cancer obtained reasonable response rates for small tumors but recurrence was common. Whole bladder irradiation, once a suitable light-delivery system had been developed, gave promising outcomes with acceptable rates of complications. PDT for prostate cancer is still at the experimental stage but initial results have been promising. Clinical trials of PDT for brain tumors have shown no significant complications but no improvement in survival rate compared with other treatment modalities. PDT is particularly useful for early superficial lung cancers that are localized to one or a few discrete sites; it is also safe to use in patients who are too sick to be treated with conventional therapies. Preoperative PDT has reduced the extent of surgery necessary in some patients. Clinical experience with PDT for gynecological cancer is limited and prospective studies are needed. In head and neck oncology, PDT should prove a useful option, but methodological problems need to be overcome. Good responses of esophageal cancer to PDT have led to governmental approval of Photofrin, a photosensitizer, in several countries for either palliative use or treatment of inoperable or recurrent cancer. The use of PDT for early gastric cancer has great potential but several technical problems remain. PDT has proven generally effective for skin cancer when hematoporphyrin derivative or Photofrin is used but more long-term follow-up data are required for PDT with 5-aminolevulinic acid. Overall, PDT is changing from a scientific curiousity into an accepted modality for the treatment of cancer, with an improved likelihood of finding further clinical applications.

Haemophilus aphrophilus bacteraemia complicated with vertebral osteomyelitis and spinal epidural abscess in a patient with liver cirrhosis

Haemophilus aphrophilus is rarely implicated as an aetiology of spinal epidural abscess. A 73-year-old woman with liver cirrhosis who developed H. aphrophilus bacteraemia complicated with vertebral osteomyelitis and spinal epidural abscess is presented. Without surgical decompression, she was successfully treated with cefotaxime for 3 weeks, followed by maintenance with ciprofloxacin for another 10 weeks. The clinical features of eight previously reported cases of vertebral osteomyelitis without epidural abscess due to H. aphrophilus are reviewed.

Tumor necrosis factor-alpha gene polymorphism in chronic bronchitis

Airway inflammation is an important pathologic feature in chronic bronchitis, and we hypothesized that individuals with greater inflammatory responses may be more likely to acquire the disease. A polymorphism at -308 position of the tumor necrosis factor-alpha (TNF-alpha) gene has been described, with the rarer allele, TNF2, demonstrated to have higher inducibility in vitro. We investigated the distribution of this polymorphism in a case-control study. The genotype was determined in 42 male patients with chronic bronchitis, 42 sex-, age-, and smoking index-matched control subjects, and 99 random-sampled schoolchildren. We report here that the TNF2 allele is overrepresented in the patient group. The allele frequency of TNF2 is 5.1% in the schoolchildren, 2.4% in the control group, and 19% in the bronchitis group (p < 0.01). Carriage of the TNF2 allele confers a higher risk to the development of chronic bronchitis (odds ratio = 11.1, 95% CI = 2.89-42.57). The results demonstrate the important pathologic role of TNF-alpha in chronic bronchitis and suggest that greater inflammatory response may predispose an individual to this disease.

The antimicrobial susceptibility of Mycobacterium chelonae isolated from corneal ulcer

PURPOSE

To determine the in vitro susceptibility of Mycobacterium chelonae isolates from corneal ulcers to various traditional and newly-developed antimicrobial agents, alone or in combination.

METHODS

Fifteen strains of M. chelonae isolated from corneal ulcers were collected at the National Taiwan University Hospital from 1989 to 1993. Susceptibility to antimicrobial agents was tested by the broth microdilution method to determine the minimum inhibitory concentration (MIC). The antimicrobial effects of combinations of antimicrobial agents were assessed by the checkerboard titration method to determine the fractional inhibitory concentration (FIC) index.

RESULTS

The MIC results showed that traditional antituberculous drugs had poor activity against M. chelonae. In the aminoglycoside group, tobramycin and amikacin had better activity than gentamicin. Among macrolides, clarithromycin was especially effective, with an MIC ranging from 0.125 to 1 microgram/ml. Among various beta-lactam antibiotics, imipenem was the only one to demonstrate good anti-mycobacterial activity. Of the quinolone group, ciprofloxacin was the most effective, with an MIC ranging from 0.5 to 16 micrograms/ml. Combination of an aminoglycoside with imipenem, ciprofloxacin or clarithromycin all showed antagonistic effect.

CONCLUSIONS

The results suggested that amikacin, clarithromyicn, imipenem and ciprofloxacin had good in vitro antimicrobial activity against M. chelonae. However, no synergistic effect could be demonstrated for combinations of an aminoglycoside with other effective drugs.

In vitro activities of antimicrobial agents, alone and in combinations, against Burkholderia cepacia isolated from blood

Burkholderia cepacia is a widespread, environmental gram-negative bacillus that is associated with nosocomial infections. This bacterium is considered to be an important pathogen in immunocompromised patients and is inherently resistant to multiple antimicrobial agents. To compare the activity of different antimicrobial agents and the potential of combinations against invasive strains of B. cepacia, we collected 36 isolates of B. cepacia from blood cultures and checked their susceptibilities to 13 antimicrobials by broth microdilution method. Most strains tested were susceptible to minocycline (94.4%), ceftazidime (86.1%), ciprofloxacin (83.3%), and trimethoprim-sulfamethoxazole (83.3%). All strains were resistant to aminoglycosides, and only some strains were susceptible to imipenem (16.7%), aztreonam (19.4%), moxalactam (25.0%), piperacillin (25.0%), and carbenicillin (47.2%). The effects of combinations of ceftazidime with amikacin, ceftazidime with ciprofloxacin, and ciprofloxacin with amikacin were assayed by checkerboard titration method. Synergistic effect was found in 28 out of 36 tested strains (77.8%), when ceftazidime was combined with amikacin, in 25 out of 36 strains (69.4%) when ceftazidime was combined with ciprofloxacin, and in only 8 out of 36 strains (22.2%) when ciprofloxacin was combined with amikacin.

Interstitial photodynamic therapy in the canine prostate with disulfonated aluminum phthalocyanine and 5-aminolevulinic acid-induced protoporphyrin IX

BACKGROUND

Photodynamic therapy (PDT) is an experimental approach for treating prostate cancer localized to the gland that does not involve surgery or irradiation. Second-generation photosensitizers 5-aminolevulinic acid (ALA) and aluminum disulfonated phthalocyanine (AlS2Pc) were studied in the normal canine prostate.

METHODS

Tissue biodistribution of photosensitizers on serial biopsies was examined using fluorescence microscopy. Photodynamic therapy was done by delivering red light interstitially at 100 mW through fibers placed under transrectal ultrasound guidance.

RESULTS

Peak levels of AlS2Pc appeared at 5-24 hr and at 3 hr for ALA. Macroscopic PDT lesions were up to 12 mm in diameter using AlS2Pc, but only 1-2 mm with ALA. Light at 300 mW caused thermal lesions. At 28 days, damaged glands remained atrophic, but the interlobular supporting stroma was well-preserved. Urethral lesions healed by 28 days without functional impairment.

CONCLUSIONS

Although the results with ALA were disappointing, PDT using AlS2Pc looks like a promising modality for treatment of localized prostate cancer.

Transrectal ultrasound guided manipulation of the canine prostate with minimum intervention

The canine prostate is a widely used and well established animal model for the assessment of therapeutic effects of laser technology in the search for better options for the treatment of benign prostatic hyperplasia. Conventionally for such experiments, the canine prostate is approached by laparotomy or transperineal urethrotomy. We have demonstrated a technique involving the use of ultrasound guided biopsy of the liver and prostate, and percutaneous laser treatment of the prostate, which has proved to be effective in reducing adverse effects on the experimental animals but without compromising scientific requirements for the experiments. We conclude that state-of-the-art percutaneous procedures not only refine animal intervention significantly but are also technically feasible for most laser studies using the canine prostate as an experimental model in the live animal.

Outbreak of scarlet fever at a hospital day care centre: analysis of strain relatedness with phenotypic and genotypic characteristics

An outbreak of scarlet fever involving 12 children occurred at a hospital day care centre from February to March 1996. Twenty-five throat isolates of Streptococcus pyogenes (GAS, group A streptococcus) available from 24 children, including 10 children with scarlet fever and 14 asymptomatic carriers, and one asymptomatic staff member were studied for the presence of genes encoding streptococcal pyrogenic exotoxin types A (speA), B (speB), and C (speC) and for protease activity. Antimicrobial susceptibilities using the E-test, cluster analysis by cellular fatty acid composition and random amplified polymorphic DNA (RAPD) patterns by means of arbitrarily-primed polymerase chain reaction (APPCR) of the isolates were performed to investigate the outbreak. Only one isolate from an asymptomatic child possessed the speA gene. All isolates possessed the speB gene and 24 (96%) isolates were positive for the speC gene. There was no difference in protease activity between isolates from children with scarlet fever and from asymptomatic carriers. Thirteen isolates (10 recovered from children with scarlet fever, two from asymptomatic children, and one from the staff member) were considered to be the same strain according to the identical antimicrobial susceptibility profile and RAPD patterns and were also considered to be similar by cluster analysis of fatty acid composition. These findings suggest that the outbreak was caused by a unique clone of GAS. We conclude that RAPD typing and cluster analysis by cellular fatty acids composition both provide a powerful tool for epidemiological investigation of GAS infections.

Usefulness of argyrophilic nucleolar organizer regions score to differentiate suspicious malignancy in pulmonary cytology

OBJECTIVE

Pulmonary cytologic specimens reported as "suspicious for malignancy" pose problems in clinical management. Silver staining for argyrophilic nucleolar organizer regions (AgNOR) has proved useful in making a cytopathologically differential diagnosis between benign and malignant cells. This study aimed to evaluate the usefulness of AgNOR score in the diagnosis of pulmonary cytologic specimens deemed inconclusive by conventional staining methods.

METHODS

Pulmonary cytologic specimens initially reported as suspicious for malignancy with Papanicolaou or May-Grünwald-Giemsa (MGG) staining obtained from 35 proved cases were destained then restained using the AgNOR technique. Another 35 cases with clear cytologic diagnosis were also examined for comparison. The median number of dots, defined as the AgNOR score, was used to differentiate malignant from benign specimens.

RESULTS

Malignant cases had significantly higher AgNOR scores than benign ones (p<0.001). There were no significant differences among smears previously stained with Papanicolaou or MGG method, among specimens obtained via bronchoscopic brushing, fine-needle aspiration of lung or pleural effusion, or among subgroups of malignant diseases. Based on the results of our previous study, the cutoff value of the AgNOR score to differentiate benignancy from malignancy was set at 6. At this setting, the sensitivity and specificity of AgNOR score were 88% and 80%, respectively, in aiding a differential diagnosis of pulmonary cytologic specimens initially classified as suspicious for malignancy. For those cases with a clear cytologic diagnosis, the sensitivity and specificity of AgNOR score were 92% and 100%, respectively. For all cases, the sensitivity of AgNOR score was 90% and the specificity was also 90%.

CONCLUSIONS

The AgNOR score is of value in aiding a differential diagnosis between benign and malignant lesions in pulmonary specimens with equivocal cytologic features.

Bacteremia due to Klebsiella oxytoca: clinical features of patients and antimicrobial susceptibilities of the isolates

Forty-three patients with Klebsiella oxytoca bacteremia were seen between July 1980 and June 1996 at National Taiwan University Hospital (Taipei, Taiwan). We retrospectively analyzed the clinical features of these patients and the antimicrobial susceptibilities of the 43 isolates recovered from them. Twenty-seven patients (63%) had community-acquired bacteremia, and 16 patients (37%) had polymicrobial bacteremia. The clinical syndromes included hepatobiliary infections (58% of patients), primary bacteremia (23%), intravascular device-associated infections (7%), urinary tract infections (5%), skin and soft-tissue infections (5%), and peritonitis (2%). Most of these patients (93%) had underlying diseases including hepatobiliary diseases (53%), neoplastic diseases (42%), and diabetes mellitus (16%). Eight patients (19%) had septic shock, and two (5%) had disseminated intravascular coagulation. Four patients (9%) died of K. oxytoca bacteremia. All isolates were susceptible to ampicillin/sulbactam, cefmetazole, imipenem, aminoglycosides, and quinolones, and 86% of the isolates were susceptible to cefazolin.

Secular trends in the epidemiology of nosocomial fungal infections at a teaching hospital in Taiwan, 1981 to 1993

OBJECTIVE

To describe the incidence and patterns of nosocomial fungal infection in a large teaching hospital in Taiwan.

DESIGN

Prospective, hospitalwide nosocomial surveillance data from 1981 through 1993 were analyzed to show the secular trend in nosocomial fungal infection rates and to identify the most common pathogens and sites of infection (other than skin) in this hospital.

SETTING AND PATIENTS

The National Taiwan University Hospital is a medical school-affiliated hospital in the city of Taipei, Taiwan, with a 1200-bed capacity before 1991 and 1500 beds since 1992. It provides both primary and tertiary medical care.

RESULTS

The overall nosocomial fungal infection rate rose from 0.9 infections per 1000 discharges in 1981 to 6.6 per 1000 discharges in 1993, with the highest rate at the medical intensive-care unit (26.5/1000 discharges in 1993). This increase in infection rate was found at four major anatomic sites of infection, particularly including the bloodstream (0.08-2.19/1000 discharges) and the urinary tract (0.36-2.95/1000 discharges). Of 256 pathogens causing nosocomial fungemia from 1981 through 1993, Candida albicans was the most commonly isolated (50.8%), followed by Candida tropicalis (17.6%). Candida parapsilosis (11.7%), and Candida glabrata (8.2%). As compared to isolates from 1981 through 1988, the proportion of C parapsilosis and C glabrata isolated between 1989 and 1993 increased more than sixfold and fourfold, respectively. The increasing importance of fungal infections was confirmed further by the increased use of amphotericin B and azoles in this hospital.

CONCLUSIONS

Candida species and other yeasts have become a prominent cause of nosocomial infections in this hospital. These fungal pathogens accounted for a higher proportion of nosocomial bloodstream and urinary infections than any single bacterial species. Therefore, it is important to conduct a prospective epidemiological study and to establish in vitro antifungal susceptibility testing to enhance efforts to control nosocomial fungal infections and to minimize the risk of emergence of antifungal resistance.

Flavimonas oryzihabitans bacteremia: clinical features and microbiological characteristics of isolates

Flavimonas oryzihabitans is rarely reported as a pathogen in humans. Twelve cases of F. oryzihabitans bacteremia were diagnosed at National Taiwan University Hospital over a 3-year period. The clinical features of these patients were analyzed, and antimicrobial susceptibilities and random amplified polymorphic DNA (RAPD) patterns of the 12 isolates were studied. Among these 12 patients, eight (67%) had underlying neoplastic diseases and all acquired F. oryzihabitans bacteremia while hospitalized. The clinical syndromes included primary bacteremia in 5 patients (42%), biliary tract infection in 3 (25%), and peritonitis, subdural empyema, infusion-related bacteremia, and pneumonia in 1 each. Polymicrobial bacteremia or concomitant fungemia was seen in three patients (25%). All the patients survived after antibiotic treatment. All isolates were susceptible to piperacillin, third-generation cephalosporins, aminoglycosides, and quinolones but resistant to cephalothin, cefuroxime, and trimethoprim. Susceptibility to aztreonam was variable (25%). The RAPD patterns differed among the isolates, indicating the epidemiological unrelatedness of these infections. F. oryzihabitans should be included as an etiology of severe nosocomial infection in patients with underlying debilitating diseases.

Treatment of frontal sinus osteoma using a craniofacial approach

Osteoma is one of most common benign tumors of the nose and paranasal sinuses, with the frontal sinus being its most frequent location. It may be locally destructive and aggressive with possible intracranial complications. Osteoma of the frontal sinus comprises 57% of all osteomas in the paranasal sinuses. In 1939, Childrey reviewed 3,510 consecutive sinus radiographs taken for any reason and found an incidence of 0.43% of paranasal sinus osteomas. There are many operative approaches for frontal sinus osteomas, such as external frontoethmoidal approach and osteoplastic frontal sinusectomy, both with high recurrence rates. Those traditional operative methods cannot radically eradiate the osteoma grown in the posterior table of the frontal sinus. From July 1991 to June 1992, three patients with symptomatic frontal sinus osteomas were operated by a craniofacial approach. One patient is presented here in detail. A coronal incision is used and is found to be beneficial both in surgical exposure and in reconstruction with a calvarial bone graft. The patient has been followed for 3.5 years without osteoma recurrence.

The efficacy of an iron chelator (CP94) in increasing cellular protoporphyrin IX following intravesical 5-aminolaevulinic acid administration: an in vivo study

5-Aminolaevulinic acid (ALA)-induced protoporphyrin IX (PpIX) is proving to be a useful photosensitizer for photodynamic therapy (PDT). Conversion of PpIX to haem requires catalysed chelation with iron, and thus the presence of an iron chelator should, in theory, lead to an increase in cellular PpIX accumulation. This paper assesses the in vivo effect of a new iron chelator, 1,2-diethyl-3-hydroxypyridin-4-one (CP94), on the kinetics of PpIX in different layers of the bladder wall. Wistar rats were given 1% or 10% ALA intravesically with or without intraperitoneal CP94. The biodistribution of ALA-induced PpIX in the bladder was evaluated using fluorescence microscopy. Photodynamic effects on the bladder were compared in rats receiving various drug dosimetries. In CP94-treated rats, 5-7 h after administration of 10% ALA solution, the fluorescence intensity of PpIX in the urothelium was doubled compared with animals given ALA alone, whereas in the muscle layer PpIX remained at a low level similar to that found without the iron chelator. At an ALA concentration of 1%, although the PpIX concentration was not increased with CP94, the urothelial selectivity of PDT compared with the muscle layer was enhanced. In conclusion, by using CP94, a further reduction in skin photosensitization may be possible as similar photodynamic effects can be achieved with a lower dose of ALA. The addition of CP94 seems to be an effective and convenient way to potentiate ALA-induced PpIX tissue selectivity between the urothelium and the underlying layers of the bladder wall.

Therapeutic effects of diuretics and paracentesis on lung function in patients with non-alcoholic cirrhosis and tense ascites

BACKGROUND/AIMS

Ascites may cause or aggravate pulmonary dysfunction in patients with liver cirrhosis. Diuretics and paracentesis are the main therapies for ascites. The aim of the present study was to evaluate and compare the therapeutic effects of diuretics and large-volume paracentesis on lung function in 26 male patients with non-alcoholic cirrhosis and tense ascites.

METHODS

The patients were divided into two groups. Group A was composed of 13 subjects who were treated with diuretics including spironolactone (100-400 mg/day) and furosemide (80-320 mg/day). In group B, 13 subjects received large-volume paracentesis plus intravenous albumin (6-8 g/l ascites removed). Pulmonary function tests including spirometry, plethysmography, single-breath carbon-monoxide diffusing capacity (DLco) and arterial blood gases, were done 1 day before diuretic treatment and 1 day after termination of the study in group A patients, and 1 day before and after large-volume paracentesis in group B subjects.

RESULTS

Before treatment, the clinical and laboratory data were comparable between the two groups. After treatment, ventilatory function as evidenced by forced expiratory volume in 1 s, forced vital capacity, total lung capacity, functional residual capacity and expiratory reserve volume, and DLco increased significantly in both groups. Arterial PO2 and PCO2 increased significantly and AaPO2 (alveolar-arterial PO2 difference) decreased significantly in the subjects treated with diuretics. Nevertheless, paracentesis did not improve arterial blood gases. The changes in lung volumes, DLco and PaO2 after treatment (the data after minus those before treatment) were comparable, except that a significant decrease in AaPO2 was observed in the diuretic group.

CONCLUSIONS

Both diuretic therapy and large-volume paracentesis significantly improved the ventilatory function in patients with tense cirrhotic ascites. In terms of oxygenation improvement as evaluated by AaPO2, diuretic treatment may be superior to large-volume paracentesis.

Usefulness of AgNOR score in differentiating benign from malignant pulmonary aspiration cytology

OBJECTIVE

Malignant cells are known to display greater argyrophil staining for nucleolar organizer regions (AgNORs) than for benign cells due to their active proliferation. In this study we assessed the diagnostic value of AgNOR staining on 47 fine needle aspiration cytologic specimens of lung previously stained with the May-Grünwald-Giemsa (MGG) method.

METHODS

Cytologic specimens obtained from fine needle aspiration of the lung in 47 proven cases prestained with the MGG technique were destained and restained with the AgNOR method. Seventeen of them were benign and 30 malignant. To differentiate malignant from benign entities, the highest median value for AgNOR number (AgNOR score) obtained from the benign cases was chosen as a cutoff point (test specificity, 100%).

RESULTS

AgNOR scores of malignant cases were significantly higher than those of benign cases (P < .001). There was no significant difference between two subgroups of benign diseases or among four subgroups of malignant diseases. The sensitivity of the AgNOR score was 93% (28/30) in providing a diagnosis of malignancy when the cutoff value was set at 6.

CONCLUSION

The AgNOR technique may be of considerable value in aiding a diagnosis of malignancy, especially when the score is > 6.

Life-threatening scrub typhus with meningoencephalitis and acute respiratory distress syndrome

A 21-year-old man presented with fever, rash, seizure, stiff neck and rapidly progressive bilateral pulmonary infiltrates. Cerebrospinal fluid (CSF) study revealed pleocytosis with predominant polymorphonuclear cells, and hypo-glycorrhachia. Status epilepticus occurred, followed by acute respiratory distress syndrome with respiratory failure. Blood and CSF cultures for bacteria were negative, but an indirect immunofluorescence assay revealed a fourfold rise in antibody to Rickettsia tsutsugamushi in paired serum and a 1:2560 (+) IgM antibody titer. Severe scrub typhus with meningoencephalitis and extensive pneumonitis was diagnosed. The patient survived after intravenous minocycline therapy and intensive care, including aggressive seizure control, supportive mechanical ventilation and avoidance of fluid overloading. He had a nearly complete recovery. Practicing physicians in Taiwan should be aware of this reportable disease and its potentially serious complications if not promptly diagnosed and treated.

Variations in oligosaccharide-protein interactions in immunoglobulin G determine the site-specific glycosylation profiles and modulate the dynamic motion of the Fc oligosaccharides

Glycoproteins, such as immunoglobulin G (IgG), consist of an ensemble of glycosylated variants, or glycoforms, which have different oligosaccharides attached to a common peptide. Alterations in the normal glycoform populations of IgG are associated with certain disease states, notably rheumatoid arthritis and its remission during pregnancy. In this paper, we show that two sets of IgG Fc glycoforms have quite different physical properties. The first set has 1,6 arm terminal galactose residues which interact with the protein, resulting in glycan binding to the protein surface, in agreement with the crystal structure. In contrast, the second set of glycoforms which lack galactose does not bind to the protein surface. Recently developed HPLC techniques combined with enzymatic digestion and mass spectrometry have been used to assign the glycan structures on IgG, Fab, and Fc. Comparison of Fab with Fc shows that glycosylation is site-specific. Two major glycan structures are present on Fab (fucosylated digalacto-bianntenary with and without bisect) and three on Fc (fucosylated agalacto-, 1,6 arm monogalacto-, and digalacto-bianntenary). In comparison to Fab, Fc glycans contain (i) lower levels of bisecting GlcNAc, (ii) lower levels of galactose, (iii) higher than expected levels of 1,6 arm galactose relative to 1,3 arm, and (iv) no 1,6 arm sialylation. We interpret these differences to indicate a role for both the protein quaternary structure and specific protein-glycan interactions in determining the glycoform populations. NMR relaxation measurements have been used to probe the mobility of the glycans in the Fc. By comparing two samples with different glycoform populations, we conclude that this mobility is dependent on the primary sequence of the glycan. Glycans carrying a galactose residue on the 1,6 arm have relaxation properties very similar to those of the peptide backbone and thus do not have independent motion. Glycans lacking galactose have relaxation rates 30 times slower than that of the peptide and thus a higher degree of mobility. These agalactosyl glycans do not interact with the protein, resulting in exposure of previously covered regions of the peptide surface and making the glycan more accessible. This implies that at the early stages of glycan processing the Fc glycans are mobile and only partially protected by the protein quaternary structure. Immobilization of the glycans occurs as a consequence of addition of galactose to the 1,6 arm and results in increased protection.

Fusarium solani fungemia in a bone marrow transplant recipient

Disseminated Fusarium solani infection, with its distinctive skin lesions, is an emerging cause of mortality in bone marrow transplant recipients worldwide. However, it has never been reported before in Taiwan. We report a 21-year-old man with disseminated fusariosis who developed fever, myalgia and generalized erythematous papules on day 8 after undergoing allogeneic bone marrow transplantation for severe aplastic anemia. Histopathology of the skin lesion revealed mycotic emboli. Cultures of both blood and tissue from skin biopsy grew Fusarium solani. Despite amphotericin B therapy, fever persisted and graft failure developed. A second transplantation, using mobilized peripheral blood stem cells from the same donor, was tried but the patient died of progressive multiple organ failure before any evidence of engraftment.

Bacteremia caused by Arcobacter cryaerophilus 1B

Arcobacter cryaerophilus group 1B, a gram-negative, curved or helical bacillus primarily known as a bovine and porcine pathogen, was isolated from the blood of a uremic patient with hematogenous pneumonia. The patient was treated successfully with ceftizoxime and tobramycin.

The wheat poly(A)-binding protein functionally complements pab1 in yeast

Poly(A)-binding protein (PAB) binds to the poly(A) tail of most eukaryotic mRNAs and influences its translational efficiency as well as its stability. Although the primary structure of PAB is well conserved in eukaryotes, its functional conservation across species has not been extensively investigated. In order to determine whether PAB from a monocot plant species could function in yeast, a protein characterized as having PAB activity was purified from wheat and a cDNA encoding for PAB was isolated from a wheat seedling expression library. Wheat PAB (72 kDa as estimated by SDS/PAGE and a theoretical mass of 70 823 Da as determined from the cDNA) was present in multiple isoforms and exhibited binding characteristics similar to that determined for yeast PAB. Comparison of the wheat PAB protein sequence with PABs from yeast and other species revealed that wheat PAB contained the characteristic features of all PABs, including four RNA binding domains each of which contained the conserved RNP1 and RNP2 sequence motifs. The wheat PAB cDNA functionally complemented a pab1 mutant in yeast suggesting that, although the amino acid sequence of wheat PAB is only 47% conserved from that of yeast PAB, this monocot protein can function in yeast.

Roles of the signal peptide and mature domains in the secretion and maturation of the neutral metalloprotease from Streptomyces cacaoi

The neutral metalloprotease (Npr) of Streptomyces cacaoi is synthesized as a prepro-Npr precursor form consisting of a secretory signal peptide, a propeptide and the mature metalloprotease. The maturation of Npr occurs extracellularly via an autoproteolytic processing of the secreted pro-Npr. The integrity of the propeptide is essential for the formation of mature active Npr but not for its secretion [Chang, Chang and Lee (1994) J. Biol. Chem. 269, 3548-3554]. In this study we investigated whether the secretion and maturation of Npr require the integrity of its signal peptide region and mature protease domain. Five signal peptide mutants were generated, including the substitution mutations at the positively charged region (mutant IR6LE), the central hydrophobic region (mutants GI19EL and G19N), the boundary of the hydrophobic core-cleavage region (mutant P30L) and at the residues adjacent to the signal peptidase cleavage site (mutant YA33SM). All these lesions delayed the export of Npr to the growth medium and also resulted in a 2-10-fold decrease in Npr export. The most severe effect was noted in mutants GI19EL and P30L. When these signal peptide mutations were fused separately with the propeptide lacking the Npr mature domain, the secretory defect on the propeptide was also observed, and this impairment was again more severely expressed in mutants GI19EL and P30L. Thus the Npr signal peptide seems to have more constraints on the hydrophobic core region and at the proline residue within the boundary of the hydrophobic core-cleavage site. Deletion mutations within the C-terminal mature protease domain that left its active site intact still blocked the proteolytic processing of mutant precursor forms of pro-Npr, although their secretions were unaffected. These results, together with our previous findings, strongly suggest that the signal peptide of Npr plays a pivotal role in the secretion of both Npr and the propeptide, but not in the maturation of Npr. On the contrary, the integrity of mature domain and propeptide is not critical for secretion of the Npr derivative but is essential for the formation of a functional Npr. Therefore the secretion and maturation of Npr are dependent on the integrity of the signal peptide, propeptide and mature protease domains, and the roles of these domains in this regard are functionally distinct.

Clinical features of tuberculosis associated with HIV infection in Taiwan

To understand the clinical characteristics and outcome of tuberculosis (TB) in patients with acquired immunodeficiency syndrome (AIDS) in Taiwan, we reviewed the medical records of 118 adult AIDS patients who were hospitalized at National Taiwan University Hospital between January 1988 and September 1995. Among them, 29 (24.6%) had TB. The mean age of the AIDS patients with TB was 37 years (range, 25-66 yr). Most patients were in the advanced stages of AIDS when human immunodeficiency virus (HIV) infection and/or TB were first diagnosed. The mean CD4+ lymphocyte count was 0.037 x 10(9)/L (range, 0-0.152 x 10(9)/L) at the time TB was diagnosed. There was no statistically significant difference in the mean CD4+ lymphocyte count between patients with isolated pulmonary TB and those with extrapulmonary involvement. Twenty-two patients (75.8%) had extrapulmonary TB with the most common site being the lymph nodes (72.7%). Clinical symptoms were nonspecific, and the chest physical examination was not helpful in the diagnosis. Acid-fast bacilli were detected in sputum smears from eight patients (36.4%). A primary tuberculosis pattern (hilar adenopathy, pleural effusion, middle or lower lobe infiltrates) in the chest radiographs was the most common radiologic finding (36.4%) in patients with pulmonary TB. The reactivation pattern (predominant upper-lobe infiltrates with or without cavitation) could only be found in cases of pulmonary TB without extrapulmonary involvement. Atypical patterns (diffuse interstitial infiltrates mimicking Pneumocystis carinii pneumonia or other patterns) and normal chest radiographs were noted in nearly one-third of the patients with pulmonary TB. A good response to antituberculosis drugs and a favorable outcome were demonstrated in the patients, except for two with drug-resistant Mycobacterium tuberculosis infection. Early identification of TB in HIV-infected patients requires clinical awareness of the unusual clinical presentations, especially among patients in the advanced stages of AIDS.

Clinical manifestations, microbiology and prognosis of 42 patients with necrotizing fasciitis

Forty-two cases of necrotizing fasciitis (NF) surgically confirmed between January 1991 and October 1995 were retrospectively reviewed. This was done in order to describe the underlying diseases, clinical presentations, etiology and outcome of NF and to assess the prognostic value of a simplified severity scoring system. The system scores changes in consciousness status, body temperature, blood pressure and ventilation to determine the likely outcome of NF. Twenty-five men and 17 women with a median age of 51 years (range, 17-87 yr) were included. Diabetes mellitus (57.1%) was the most common underlying disease. The mean duration of symptoms before admission was 8 days (median, 7 d; range, 1-30 d). The extremities (66.7%) were most commonly involved. Initial clinical presentations within 48 hours of admission included skin erythema and swelling at the affected site (97.6%), pyrexia (61.9%), hypotension (33.3%), altered consciousness (28.6%), bullous lesions (26.2%) and crepitus (9.5%). The mean number of isolated pathogens was 1.8 (range, 0-6). Eight patients had mixed aerobic and anaerobic infections. The attributable case fatality rate was 23.8%. Higher severity score (> or = 4 points), hypotension, altered consciousness, respiratory failure requiring ventilator support, elevation of alanine aminotransferase levels > twofold, serum creatinine > 177 mumol/L, thrombocytopenia (< 100 x 10(9)/L), and worsening symptoms and signs within 48 hours of admission were associated with higher fatality rates (p < 0.05).

Age-related 4,977 bp deletion in human lung mitochondrial DNA

The accumulation of mitochondrial DNA (mtDNA) mutations has been suggested to be an important contributor to human aging and degenerative diseases. The lung is exposed to ambient air and makes direct contact with the external environment. Numerous potentially noxious agents may damage lung tissues directly or indirectly through free-radical-mediated reactions. In previous studies, we demonstrated an age-dependent increase of mtDNA mutations in various human tissues. We hypothesize that the accumulation of the 4,977 bp (base pairs) deleted mtDNA in human lung tissues is also age-dependent. Using the polymerase chain reaction technique, we determined the incidence of the 4,977 bp-deleted mtDNA in 127 human lung specimens from 34-wk gestation to 79 yr of age. The results showed that 77 lung biopsies (60.6%) contained the 4,977 bp-deleted mtDNA, which started to appear in lung tissues after the fourth decade of life. The incidence apparently increased from 14.3% (one of seven) of the subjects in the 30- to 39-yr age group to 77.8% (two of 27) of the subjects in the 70- to 79-yr age group (p < 0.0001). The mean (+/- SEM) proportion of the 4,977 bp-deleted mtDNA in lung tissues significantly increased from 0.007 +/- 0.007% of the subjects in the 30- to 39-yr age group to 0.833 +/- 0.330% of those in the 70- to 79-yr age group (p < 0.005). Other factors such as sex, pulmonary function indices, and smoking status did not have statistically significant impact on the amount of the deleted mtDNA. These findings suggest that the accumulation of the 4,977 bp-deleted mtDNA is associated with aging human lung.