In vitro evaluation of intracellular activity of antibiotics against non-typhoid Salmonella

Non-typhoid salmonellae are the most common causative organisms of bacterial enteritis in children. Clinical studies have failed to show any influence of various antibiotics on the natural course of acute salmonella enteritis. Poor penetration of antibiotics into phagocytic cells that contain intracellular Salmonella spp., and possible intracellular antibiotic inactivation have been considered as possible reasons for this. In this study, we used an in vitro model to assess the intracellular activity of antibiotics against non-typhoid salmonellae. The survival of intracellular Salmonella spp. in P388D1 cells, a mouse macrophage cell line was measured in the presence of various antibiotics. Except for gentamicin, which entered phagocytes poorly, ofloxacin, azithromycin, chloramphenicol and three beta-lactam antibiotics, ampicillin, cefixime and ceftriaxone, exhibited bacteriostatic activity against susceptible intracellular Salmonella spp. at an extracellular concentration equal to the minimal inhibitory concentration (MIC). At a concentration of 10 x MIC, neither chloramphenicol nor the three beta-lactam antibiotics produced a bactericidal response; however, both ofloxacin and azithromycin were bactericidal after 8-24 h of incubation. The results showed that fluoroquinolones and new macrolides were more efficient than the other antibiotics in eradicating intracellular salmonella and might be useful agents for the treatment of non-typhoid salmonella enteritis in children. Clinical trials should be considered.

Prevention of hypotension after spinal anesthesia for cesarean section: dextran 40 versus lactated Ringer's solution

BACKGROUND

This study was designed to compare the efficacy of 10% dextran 40 with lactated Ringer's (LR) solution in reducing the incidence and severity of hypotension after spinal anesthesia for Cesarean section.

METHODS

Sixty ASA grade I patients scheduled for Cesarean section were randomized into two groups in a double-blind fashion to receive either 500 ml of dextran 40 or 1000 ml of LR solution prior to induction of spinal anesthesia.

RESULTS

The incidence of hypotension was 16 in 30 (53.3%) in the LR solution group and 8 in 30 (26.7%) in the dextran group (P < 0.05). The required dose of ephedrine for treatment of hypotension was significantly greater in the LR solution group than in the dextran group (15.5 mg versus 3.2 mg, P < 0.05). Neonatal outcome, as determined by Apgar score, was good and similar in both groups.

CONCLUSIONS

We concluded that 500 ml of dextran 40 is more effective than 1000 ml of lactated Ringer's solution in reducing the incidence of hypotension induced by spinal anesthesia.

Radiographic presentation of pulmonary tuberculosis in young children

Ten cases of pulmonary tuberculosis (TB) with the isolation of Mycobacterium tuberculosis in patients under 6 years of age occurring between July 1994 and June 1998 were retrospectively reviewed. Radiographs showed air-space consolidation (n = 4), micronodular (n = 3) and miliary lesions (n = 1). Two patients showed non-specific bronchopneumonic infiltrations. Other uncommon radiographic findings include pneumatocele formation and pleural effusion. Lymphadenopathies were detected in 6 (60%) cases using chest radiographs or computed tomography (CT), commonly with involvement of the paratracheal and hilar lymph nodes. However, most lymph node enlargement was not noted in routine postero-anterior (PA) radiographs and usually required a chest CT scan for confirmation. Since lymphadenopathy is common in children with pulmonary TB in Taiwan, we suggest using chest CT scans to detect such pathology in cases of suspected TB if other diagnostic tests are not conclusive.

Pregnancy with primary tubal placental site trophoblastic tumor--A case report and literature review

Placental site trophoblastic tumor (PSTT) is a rare trophoblastic neoplasm with malignant potential. The diagnosis and prognosis of this rare disease remain difficult. A case of tubal PSTT with the primary manifestation of internal bleeding at 30 weeks' gestation is presented. Emergency exploratory laparotomy and right partial salpingectomy were performed initially. Total abdominal hysterectomy, bilateral salpingo-oophorectomy, and omentectomy were done immediately after cesarean section at 34 weeks' gestation. No further adjuvant therapy was given after surgery. No evidence of tumor recurrence or signs of metastasis were noted during 12 months of follow-up. Heterotopic pregnancy, one with intrauterine normal pregnancy and the other with implanting in the right fallopian tube and placental site trophoblastic tumor transformation, was proposed. To our knowledge, this is the first such case in the English literature.

Diagnosis of necrotizing fasciitis in children

Necrotizing fasciitis is a rare but progressive soft tissue infection. This condition is difficult to recognize in the early phase, when it is often confused with cellulitis. We report the cases of four children with necrotizing fasciitis. The initial presentation in these cases was cellulitis. Fever and soft tissue swelling occurred within 24 h and spreading erythema within 4 to 12 h. Radiologic studies of the lesions showed soft tissue thickening. Ultrasonography of the lesions demonstrated distorted, thickened fascia with fluid accumulation. Well-defined, loculated abscesses were demonstrated in two cases. Although typical dusky skin and purplish patches were not found in our cases, necrotizing fasciitis was strongly suspected on the basis of the clinical course and sonographic findings. Ultrasonography also was used as a guide for aspiration of pus. Gram-stained smears and bacterial cultures yielded the pathogens. The choice of antibiotic therapy was made on the results of smears and culture. All patients survived after immediate surgical debridement, intensive antibiotic therapy, and aggressive wound care. In conclusion, ultrasonography provides a rapid and valuable diagnostic modality for necrotizing fasciitis. The pus obtained through sonographically guided aspiration for bacterial culture can allow identification of the pathogenic organisms.

Predictors for extraintestinal infection of non-typhoidal Salmonella in patients without AIDS

To identify the risks and predictors for extraintestinal infection (EII) in patients with non-typhoidal salmonellosis, we undertook a study of 398 patients with cultures positive for non-typhoidal Salmonella seen at Chang Gung Memorial Hospital and Chang Gung Children's Hospital between November 1993 and October 1994. Salmonella choleraesuis was the most invasive serotype observed. S. panama, S. typhimurium and S. schwarzengrund were the commonest causes of EII among those serotypes usually causing gastroenteritis. Pre-existing underlying disease, particularly immunosuppressive disease, was the most important risk factor that may have predisposed adult patients to have EII. Old age (> or = 60 years) and isolation of invasive serotypes were also frequently associated with EII in adult patients. The characteristics of paediatric patients with a high probability of having EII were: < 3 years of age, abnormal blood test results (a leucocyte count > or = 15,000/mm3 or < 5000/mm3, immature leucocytes > or = 10% of total leucocytes, and a C-reactive protein concentration > or = 50 mg/l); and isolation of invasive serotypes. This information can be an aid to early diagnosis and treatment of EII caused by non-typhoidal Salmonella.

Outbreak of Candida parapsilosis fungemia in neonatal intensive care units: clinical implications and genotyping analysis

During a 5-month period, 17 infants hospitalized in neonatal intensive care units of a medical center and a branch hospital developed 18 episodes of Candida parapsilosis fungemia. The mean age at onset was 35 days. Prior to fungemia, all the infants had received hyperalimentation and antibiotics, and 15 infants had had central venous catheters. The presenting symptoms were variable but only vague in 40% of the episodes. Despite administration of antifungal agents, subsequent eradication of fungemia was achieved in only two-thirds of the episodes. None of the environmental samples was positive for C. parapsilosis, while 20% of hand-washing samples of staff working in both units yielded this microorganism. Four genotypes with two main types were identified from 14 outbreak strains and eight genotypes from 14 hand-washing strains, with one type predominant. The results suggest that C. parapsilosis fungemia increases the morbidity and mortality of neonates but does not cause acute lethal events. The outbreak was caused by two main genotypes, possibly via cross-infection by the hands of health care workers.

Prompt recognition of necrotizing fasciitis in a newborn

We report a 13-day-old female neonate with necrotizing fasciitis, who presented with fever and erythema on her back. Rapidly progressive extension of the erythema to the abdominal wall occurred within 12 hours. Sonography for the lesion showed extensive fascial thickening with fluid accumulation. An abscess was also demonstrated. Necrotizing fasciitis was highly suspected. Under sonographic guidance, pus was aspirated from the abscess. A smear for the aspirated pus revealed a large number of neutrophils and abundant gram-positive cocci. Immediate surgical debridement was done. Cultures from the pus and blood revealed Staphylococcus aureus. The patient was free of symptoms after surgical debridement and aggressive antibiotic therapy. She had skin grafting to reconstruct the debrided wound on the 20th hospital day and was discharged shortly after the debridement of wound.

Congenital tracheobronchial stenosis in monozygotic twins

A pair of monozygotic twins suffering from noisy respirations and recurrent wheezes since early infancy were referred for evaluation. Using direct coronal CT and 3-dimensional reconstruction of the airway, congenital tracheobronchial stenosis was found in both twin babies, later confirmed by fibre optic bronchoscopy. The cause of congenital tracheobronchial stenosis remains obscure, but even in monozygotic twins an unidentified environmental factor cannot be excluded and may be responsible for discordant bronchopulmonary abnormalities.

CONCLUSION

This case report shows that tracheobronchial stenosis may present in monozygotic twins. The pattern of malformation in twins differs from cases described previously.

Activating a zymogen without proteolytic processing: mutation of Lys15 and Asn194 activates trypsinogen

The zymogen and mature enzyme forms of trypsin-like serine proteases exhibit a wide range of activities. The prototypical trypsinogen-trypsin system is an example of a minimally active zymogen and a maximally active mature protease. The present work identifies several features of trypsinogen which govern its activity. Our results indicate that rat trypsin is 10(8)-fold more active than rat trypsinogen. Rat trypsinogen appears to be less active than bovine trypsinogen. His40 is believed to be an important determinant of zymogen activity. We are unable to verify this role for His40 in trypsinogen since the mutation of His40 to Phe appears to change the trypsin-substrate interface. Deletion of the N-terminal Ile16 from trypsin is expected to produce a trypsinogen-like protein since the Ile16-Asp194 salt bridge cannot form. Such mutants have higher activity and BPTI affinity than trypsinogen, which indicates that the activation peptide stabilizes the inactive trypsinogen conformation. The mutation of Lys15 to Ala increases the BPTI affinity and activity of trypsinogen to an even greater extent; thus, removal of Lys15 can account for the effect of the loss of the activation peptide. These results suggest that Lys15 is an important determinant of zymogen activity. The mutation of Asp194 to Asn also increases the BPTI affinity and activity of trypsinogen. This result suggests that in addition to stabilizing the active conformation of trypsin via the Ile16-Asp194 salt bridge, Asp194 also maintains the inactive conformation of trypsinogen. A correlation exists between the values of kcat/Km and BPTI affinity of mutant trypsinogens and trypsins. However, the slope of this correlation is 0.64, which indicates that different "active" conformations are involved in BPTI binding and substrate hydrolysis. DeltaI16V17 trypsinogen is the lone outlier; its BPTI affinity is higher than would be expected based on the value of kcat/Km. We show that the rate of BPTI association is slower for DeltaI16V17 trypsinogen than for a mutant trypsinogen with a similar BPTI affinity. This observation suggests that BPTI binds to an "active" trypsinogen conformation that is not kinetically accessible to substrates.

Outbreak of Candida albicans fungaemia in a neonatal intensive care unit

During a 4-month period, 9 premature infants hospitalized in a neonatal intensive care unit (NICU) developed Candida albicans fungaemia. All 9 infants received antifungal agents. Fluconazole was administered in 7 patients and successfully eradicated this organism in 6 with no adverse effects. For epidemiological investigation, 64 environmental specimens and hand-washings of all 54 staff members involved in the NICU were examined for the presence of this organism. No C. albicans could be identified from environmental sources, while the hand-washing of 1 nurse was C. albicans-positive. Two genotyping methods, including electrophoretic karyotyping using contour-clamped homogeneous electric field gel electrophoresis and polymerase chain reaction-based direct sequencing of rRNA gene, were used in the analysis of the isolates recovered from blood cultures of the infants, the hand-washing of the nurse and 7 control isolates. Both methods yielded comparable results and revealed that all 13 isolates from infected infants as well as the isolate from hand washing of the nurse were of the same genotype while the control isolates were distinct. These results suggest that the outbreak of C. albicans fungaemia was caused by a particular strain and possibly via cross-infection. In addition, we showed that fluconazole seemed to be safe and effective in treating C. albicans fungaemia in neonates, although the data were limited.

Association of fungal colonization and invasive disease in very low birth weight infants

BACKGROUND

Fungi are common pathogens of nosocomial infections in the very low birth weight (VLBW) infants. The purpose of this study was to investigate the fungal colonization rate in VLBW infants and the association between fungal colonization and systemic fungal diseases.

MATERIALS

Between January 1, 1996, and December 31, 1996, 116 infants with birth weight < 1500 g admitted to the neonatal intensive care unit of Chang Gung Children's Hospital in the first day of life were included in this prospective study.

METHODS

Cultures from oropharynx, rectum, skin (groin and axilla), bag urine and endotracheal aspirates were obtained in the first 24 h after birth and weekly thereafter throughout their neonatal intensive care unit stay. Medical records were reviewed weekly.

RESULTS

Fungal colonization was detected in 25 infants, among whom 17 infants developed colonization by 2 weeks of life. Candida albicans (61%) and Candida parapsilosis (29%) were the 2 most common organisms. The rectum (76%) was the most frequent site of colonization. Factors significantly associated with colonization were prolonged administration of antibiotic therapy, parenteral nutrition and intralipid emulsion. Three of 116 infants developed fungemia. The association between colonization and subsequent fungemia was demonstrated in 1 infant, representing 4% of colonized infants.

CONCLUSION

Fungal colonization was detected in one-fifth of VLBW infants and represents a risk factor for fungemia. Because disease occurred in the absence of apparent colonization, factors other than colonization may contribute to invasive candidiasis.

Antimicrobial susceptibilities of Campylobacter jejuni and coli by using E-test in Taiwan

To report the in vitro antibiotic susceptibility of Campylobacter species, we determined the MICs of 6 antibiotics by E-test for 93 human clinical strains and 35 chicken strains. The 6 antimicrobial agents tested were gentamicin, erythromycin, clindamycin, tetracycline, ciprofloxacin, and nalidixic acid. Isolates from humans were significantly more susceptible than chicken strains to erythromycin, clindamycin and ciprofloxacin. Nearly all of the human and chicken strains were susceptible to gentamicin. Among human isolates of C. jejuni, cross-resistance between nalidixic acid and ciprofloxacin was found in 66% of the strains, but none of the nalidixic acid-susceptible strains was resistant to ciprofloxacin. The higher prevalence of ciprofloxacin resistance in this area may be attributable to the large amount use of quinolones in poultry. Because of the high resistance rates of chicken isolates to the commonly used antimicrobial agents, it is necessary to create innovative methods to limit the inappropriate use of antibiotics in poultry in order to prevent the spread of the drug-resistant strains to humans.

Characterization and functional analysis of the porcine lactoferrin gene promoter

Lactoferrin, a ferric binding glycoprotein found in milk, can possibly prevent microbial infection of the mammary gland and gastrointestinal tract. To define the regulation of the porcine lactoferrin gene (pLTF), we cloned its 5'-flanking region from a porcine liver genomic library and analyzed the 5' upstream region of approx. 4kb, two exons, and an intron. The transcription start site was localized by primer extension to residue G, which is 41 nucleotides upstream from the ATG start codon. The pLTF 5'-flanking region possesses several putative cis-acting regulatory elements found in both housekeeping and inducible genes; to define their function, they were inserted into a chloramphenicol acetyltransferase reporter construct. The region up to -156 sufficed for basic promoter activity, whereas the region up to -780 was required for maximal promoter activity in porcine testis cells (STcells), kidney cells (PK15 cells) and human mammary epithelial cells (HBL-100 cells). Detailed analysis of this proximal region by DNase I footprinting and electrophoretic mobility shift assays reveals that the ubiquitous factors SP1, AP2 and the mammary gland-specific factor (MGF) might play significant roles in regulating the transcription of the pLTF gene.

Spontaneous resolution of an intratracheal mass: report of one case

A 14 year-old boy was investigated for a slowly resolving right upper lobe consolidation persisting for 3 months after a pneumonic episode. A flexible bronchoscopy showed a polypoid mass in the carina with extension to the right proximal bronchus. The bronchial washings study for fungus, acid-fast bacilli and polymerase chain reaction for mycobacterium were negative. A reported bronchoscopic examination 8 months later revealed no tracheal mass or subsequent stenosis. A tracheal mass in an asymptomatic and non-progressive child may be managed alternatively by repeated bronchoscopic examinations at intervals instead of immediate bronchoscopic excision or thoracotomy.

Swyer James syndrome following Mycoplasma pneumoniae pneumonia: report of one case

A previous healthy 5 year-old girl developed a right hyperlucent lung following Mycoplasma pneumoniae pneumonia 14 months before admission. Serial chest radiographs revealed a persistent right upper lobe atelectasis and gradual development of the right hyperlucent lung associated with frequent bouts of wheezing and exertional dyspnea. Physical examination showed markedly decreased breathing sounds in the right hemithorax with fine inspiratory crackles and expiratory wheezes. A diagnosis of Swyer James syndrome was confirmed by the exclusion of other causes of unilateral hyperlucent lung using computed tomographic scans of chest, fiberoptic bronchoscopy and lung perfusion scintigraphy. She has been followed up at our hospital using anti-asthmatic medication.

Schizophrenia: conceptual change in modern psychiatry

Schizophrenia is perhaps the most devastating mental illness that psychiatrists must treat. Its chronic course with deteriorating consequences has been the focus of study throughout this century. This paper reviews the concept of schizophrenia, from fundamental Kraepelinian theory of 'dementia praecox' to biological correlates and explanation. Its causes, however, remain obscure and there were no appreciable changes in its treatment modality. A 'bio-psycho-social' model of care is emphasized, aiming at the prevention of deterioration of symptoms, functional impairment, disability and social handicap.

Hair growth cycle affects hair follicle destruction by ruby laser pulses

It has been shown that normal mode ruby laser pulses (694 nm) are effective in selectively destroying brown or black pigmented hair follicles in adult Caucasians. This study investigated how the various stages of the hair follicle growth cycle influence follicle destruction by ruby laser treatment, using a model of predictable synchronous hair growth cycles in the infantile and adolescent mice. A range of ruby laser pulse fluences was delivered during different stages of the hair growth cycle, followed by histologic and gross observations of the injury and regrowth of hair. Actively growing and pigmented anagen stage hair follicles were sensitive to hair removal by normal mode ruby laser exposure, whereas catagen and telogen stage hair follicles were resistant to laser irradiation. Selective thermal injury to follicles was observed histologically, and hair regrowth was fluence dependent. In animals exposed during anagen, intermediate fluences induced nonscarring alopecia, whereas high fluences induced scarring alopecia. The findings of this study suggest treatment strategies for optimal laser hair removal.

Downregulation and subcellular redistribution of the gamma-aminobutyric acidA receptor induced by tunicamycin in cultured brain neurons

The significance of N-linked glycosylation and oligosaccharide processing was examined for the expression of gamma-aminobutyric acidA receptor (GABA(A)R) in cultured neurons derived from chick embryo brains. Incubation of cultures with 5 microg/ml of tunicamycin for 24 h blocked the binding of 3H-flunitrazepam and 3H-muscimol, probes for the benzodiazepine and GABA sites on the receptor, by about 20% and 28%, respectively. The loss of ligand binding was due to a reduction in the number of binding sites with no significant changes in receptor affinity. Light microscopic immunocytochemistry also revealed that the treatment reduced approximately 13% of the intensity of GABA(A)R immunoreactivity in the neuronal somata. Furthermore, the fraction of intracellular receptors was decreased to 24% from 34% of control in the presence of the agent, as revealed by trypsinization of cells in situ followed by 3H-flunitrazepam binding. The molecular weight of the receptor subunit protein was lowered around 0.5 kDa after tunicamycin treatment, in accordance with that following N-glycosidase F digestion, indicating the blockade of N-linked glycosylation of GABA(A)R by tunicamycin. Moreover, intense inhibitions of 91% and 44%, respectively, were detected to the general galactosylation and mannosylation in the tunicamycin-treated cells, whereas the protein synthesis was hindered by 13%, through assaying the incorporation of 3H-sugars and 3H-leucine. Nevertheless, treatment with castanospermine or swainsonine (10 microg/ml, 24 h), inhibitors to maturation of oligosaccharides, failed to produce significant changes in the ligand binding. In addition, in situ hybridization analysis showed that these three inhibitors did not perturb the mRNA of GABA(A)Ralpha1-subunit. The data suggest that tunicamycin causes the downregulation and subcellular redistribution of GABA(A)R by producing irregularly glycosylated receptors and modifying their localization. Both galactosylation and mannosylation during the process of N-linked glycosylation may be important for the functional expression and intracellular transport of GABA(A)R.

Yeast carriage on hands of hospital personnel working in intensive care units

The frequency and distribution of yeast carriage on the hands of hospital personnel working in intensive care unit (ICUs), was investigated. Hand carriage of yeast and Candida species was 46 and 29%, respectively. Rhodotorula sp. and Candida parapsilosis were most frequently recovered. There was no significant difference in frequency or distribution of yeasts and Candida sp. recovered among the three ICUs. Seventeen C. parapsilosis isolates and three Candida albicans isolates were genotyped by electrophoretic karyotyping using contour-clamped homogenous electric-field gel electrophoresis. Eleven separate types of C. parapsilosis and two types of C. albicans were identified. There was no common genotype among these isolates, even within the same unit. We conclude that yeast carriage on the hands of personnel working in ICU is common, but these yeasts are usually not acquired from a common source in the ICU.

Hypothermia predisposing to Pseudomonas putida sepsis in a child with panhypopituitarism

A 14-year-old boy presented with a 1-week history of hypothermia and obtundation. His medical history included surgical resection of craniopharyngioma with postoperative visual impairment and panhypopituitarism. The patient's rectal temperature remained persistently lower than 35 degrees C during the first 3 days of hospitalization. His blood pressure was 90/56 mmHg on admission. The peripheral blood leukocyte count was 2.7 x 10(10)/L with 18% neutrophils, 19% band forms, 44% metamyelocytes, 3% myelocytes, and 16% lymphocytes. The C-reactive protein concentration was 133.9 mg/L. Two separate blood cultures both yielded Pseudomonas putida. The patient was treated with amikacin and ceftazidime along with aggressive fluid therapy. Replacement therapy directed at his hormonal deficiencies was initiated as soon as his hemodynamic status was stabilized. The patient responded well to therapy with a gradual rise in body temperature and improvement in general activity. A growth experiment carried out on the P. putida isolate showed that the bacteria grew more rapidly at 30 degrees C than at 37 degrees C. The clinical course of the patient, as well as the results of the laboratory study, suggest that hypothermia may predispose human infection with P. putida.

Hemoptysis in children

BACKGROUND

Hemoptysis is rare in children, yet is one of the most frightening manifestations of cardiopulmonary disease. A wide spectrum of diseases has been reported to cause hemoptysis in children, but the search for a specific cause can be tedious and unrewarding. Early diagnosis and interventions of hemoptysis are extremely important for the successful management of this potentially lethal process in children.

METHODS

From July 1994 to June 1996, 15 pediatric patients ranging from 1 month to 15 years of age were admitted to the Pulmonology division for the investigation of hemoptysis. We retrospectively reviewed the clinical records and diagnostic evaluations of these patients.

RESULTS

Six (40%) of the patients investigated were infectious in origin, only one patient had tuberculous infection. Three patients had a traumatic cause and 2 patients had foreign bodies in the airway. Two cases had no obvious contributing cause of hemoptysis despite extensive investigations. One patient had hematemesis because bleeding from esophageal ulcerations was misinterpreted as hemoptysis. One patient had varicosed tracheal and bronchial collaterals causing massive hemoptysis due to portal vein obstruction and hypertension.

CONCLUSION

Pulmonary infection was the leading cause of hemoptysis in the 15 children we studied, but Mycobacterium tuberculosis is an uncommon causative agent. Bronchoscopy is an extremely useful tool for the diagnosis and localization of hemoptysis. Hematemesis may be misinterpreted as hemoptysis, particularly when an accurate history is not possible in children, therefore, bleeding from the upper aerodigestive tract should be studied meticulously and excluded adequately using endoscopy.