Quantifying the size-resolved dynamics of indoor bioaerosol transport and control.

Understanding the bioaerosol dynamics of droplets and droplet nuclei emitted during respiratory activities is important for understanding how infectious diseases are transmitted and potentially controlled. To this end, we conducted experiments to quantify the size-resolved dynamics of indoor bioaerosol transport and control in an unoccupied apartment unit operating under four different HVAC particle filtration conditions. Two model organisms (Escherichia coli K12 and bacteriophage T4) were aerosolized under alternating low and high flow rates to roughly represent constant breathing and periodic coughing. Size-resolved aerosol sampling and settle plate swabbing were conducted in multiple locations. Samples were analyzed by DNA extraction and quantitative polymerase chain reaction (qPCR). DNA from both organisms was detected during all test conditions in all air samples up to 7 m away from the source, but decreased in magnitude with the distance from the source. A greater fraction of T4 DNA was recovered from the aerosol size fractions smaller than 1 µm than E. coli K12 at all air sampling locations. Higher efficiency HVAC filtration also reduced the amount of DNA recovered in air samples and on settle plates located 3-7 m from the source.

Severity of symptoms, physical functioning and satisfaction in patients with lumbar spinal stenosis: a validation study of the Iranian version of the Swiss Spinal Stenosis Score.

AIM: A common cause of low back pain is lumbar spinal stenosis (LSS). The Swiss Spinal Stenosis Score (SSS) is a well-known questionnaire that measures the severity of symptoms, physical functioning and patient's satisfaction in lumbar spinal stenosis. This study aimed to translate and validate the SSS in Iran. METHODS: A prospective clinical validation study was performed. Forward-backward procedure was applied to translate the original questionnaires into Persian. A sample of patients with lumbar spinal stenosis completed the questionnaire twice: at pre- and postoperative (6 months follow-up) assessments. To test reliability the internal consistency was assessed by the Cronbach's alpha coefficient. Validity was evaluated using the known groups comparison. In addition the Oswestry Disability Index was used to perform convergent validity. RESULTS: In all 121 patients were entered into the study. The mean age of patients was 62.3 (SD=10.2) years. The Cronbach's alpha coefficient for the SSS was 0.88. Validity was performed by known groups analysis and showed satisfactory results. The instrument discriminated well between the subgroups of patients who differed in age, severity of lumbar spinal stenosis, and the Self-Paced Walking Test (SPWT). The change in the Oswestry Disability Index strongly correlated with the change in patients' scores on the SSS; lending support to its good convergent validity (r=0.82; P<0.001). CONCLUSION: The Iranian version of Swiss Spinal Stenosis Score performed well and the findings suggest that it is a valid measure of symptoms, physical functioning and satisfaction among patients with lumbar spinal stenosis.

Design, fabrication, and evaluation of single- and multi-level 3D-printed non-covering cervical spinal fusion surgery templates.

Background: Cervical spinal fusion surgeries require accurate placement of the pedicle screws. Any misplacement/misalignment of these screws may lead to injuries to the spinal cord, arteries and other organs. Template guides have emerged as accurate and cost-effective tools for the safe and rapid insertions of pedicle screws. Questions/Purposes: Novel patient-specific single- and multi-level non-covering templates for cervical pedicle screw insertions were designed, 3D-printed, and evaluated. Methods: CT scans of two patients were acquired to reconstruct their 3D spine model. Two sets of single-level (C3-C7) and multi-level (C4-C6) templates were designed and 3D-printed. Pedicle screws were inserted into the 3D-printed vertebrae by free-hand and guided techniques. For single-level templates, a total of 40 screws (2 patients × 5 vertebrae × 2 methods × 2 screws) and for multi-level templates 24 screws (2 patients × 3 vertebrae × 2 methods × 2 screws) were inserted by an experienced surgeon. Postoperative CT images were acquired to measure the errors of the entry point, 3D angle, as well as axial and sagittal plane angles of the inserted screws as compared to the initial pre-surgery designs. Accuracy of free-hand and guided screw insertions, as well as those of the single- and multi-level guides, were also compared using paired t-tests. Results: Despite the minimal removal of soft tissues, the 3D-printed templates had acceptable stability on the vertebrae during drillings and their utilization led to statistically significant reductions in all error variables. The mean error of entry point decreased from 3.02 mm (free-hand) to 0.29 mm (guided) using the single-level templates and from 5.7 mm to 0.76 mm using the multi-level templates. The percentage reduction in mean of other error variables for, respectively, single- and multi-level templates were as follows: axial plane angle: 72% and 87%, sagittal plane angle: 56% and 78%, and 3D angle: 67% and 83%. The error variables for the multi-level templates generally exceeded those of the single-level templates. The use of single- and multi-level templates also considerably reduced the duration of pedicle screw placements. Conclusion: The novel single- and multi-level non-covering templates are valuable tools for the accurate placement of cervical pedicle screws.

Monitoring outcomes in children with acquired brain injury (ABI): a Persian validation study of Child and Family Follow-up Survey (CFFS).

AIM: To translate and validate the Child and Family Follow--up Survey (CFFS) in Iran. METHODS: 49 cases with Acquired Brain Injury (ABI), and 30 healthy children were included and the CFFS was completed. The Pediatric Quality of Life Inventory (PedsQL) also was completed. The internal consistency, test-retest reliability, known groups comparison and criterion validity were assessed. RESULTS: The mean age of participants was 10.9 years. Cronbach's alpha coefficients were Child and Adolescent Scale of Participation (CASP) (0.91), Child and Adolescent Factors Inventory (CAFI) (0.90) and Child and Adolescent Scale of Environment (CASE) (0.89). Reliability, validity and correlation of CASP and CAFI showed satisfactory results. Significant correlations among the three CFFS subscale scores were observed. These scores were also significantly correlated with the total scores of the PedsQL. CONCLUSION: The findings suggest that CFFS is a valid measure to monitor long--term outcomes of children and young adolescents with ABI.

Continuous 24-hour intravenous infusion of recombinant human growth hormone (GH)-releasing hormone-(1-44)-amide augments pulsatile, entropic, and daily rhythmic GH secretion in postmenopausal women equally in the estrogen-withdrawn and estrogen-supplemented states.

How estrogen amplifies GH secretion in the human is not known. The present study tests the clinical hypothesis that estradiol modulates the stimulatory actions of a primary GH feedforward signal, GHRH. To this end, we investigated the ability of short-term (7- to 12-day) supplementation with oral estradiol vs. placebo to modulate basal, pulsatile, entropic, and 24-h rhythmic GH secretion driven by a continuous iv infusion of recombinant human GHRH-(1--44)-amide vs. saline in nine healthy postmenopausal women. Volunteers underwent concurrent blood sampling every 10 min for 24 h on four occasions in a prospectively randomized, single blind, within-subject cross-over design (placebo/saline, placebo/GHRH, estradiol/saline, estradiol/GHRH). Intensively sampled serum GH concentrations were quantitated by ultrasensitive chemiluminescence assay. Basal, pulsatile, entropic (feedback-sensitive), and 24-h rhythmic modes of GH secretion were appraised by deconvolution analysis, the approximate entropy (ApEn) statistic, and cosine regression, respectively. ANOVA revealed that continuous iv infusion of GHRH in the estrogen-withdrawn (control) milieu 1) amplified individual basal (P = 0.00011) and pulsatile (P < 10(-13)) GH secretion rates by 12- and 11-fold, respectively; 2) augmented GH secretory burst mass and amplitude each by 10-fold (P < 10(-11)), without altering GH secretory burst frequency, duration, or half-life; 3) increased the disorderliness (ApEn) of GH release patterns (P = 0.0000002); 4) elevated the mesor (cosine mean) and amplitude of the 24-h rhythm in serum GH concentrations by nearly 30-fold (both P < 10(-12)); 5) induced a phase advance in the clocktime of the GH zenith (P = 0.021); and 6) evoked a new 24-h rhythm in GH secretory burst mass with a maximum at 0018 h GH (P < 10(-3)), while damping the mesor of the 24-h rhythm in GH interpulse intervals (P < 0.025). Estradiol supplementation alone 1) increased the 24-h mean and integrated serum GH concentration (P = 0.047); 2) augmented GH secretory burst mass (P: = 0.025) without influencing pulse frequency, duration, half-life, or basal secretion; 2) stimulated more irregular patterns of GH release (higher ApEn; P = 0.012); and 3) elevated the 24-h rhythmic GH mesor (P = 0.0005), but not amplitude. Notably, combined stimulation of the GH axis with GHRH-(1--44)-amide and estradiol exerted no further effect beyond that evoked by GHRH alone, except for normalizing the acrophase of 24-h GH rhythmic release and elevating the postinfusion plasma insulin-like growth factor I concentration (P = 0.016). Unexpectedly, the two GHRH-infused serum GH concentration profiles monitored after placebo and estradiol pretreatment showed strongly nonrandom synchrony with a 20- to 30-min lag (P < 0.001). In summary, the present clinical investigations unmask a 3-fold (pulsatile, entropic, and daily rhythmic) similitude between the neuroregulatory actions of estradiol and GHRH in healthy postmenopausal women. However, GHRH infusion was multifold more effectual than estradiol, and only GHRH elevated nonpulsatile (basal) GH secretion, shifted the GH acrophase, and synchronized GH profiles. Given the nonadditive nature of the joint effects of estradiol and GHRH on pulsatile and entropic GH release, we hypothesize that estrogen amplifies GH secretion in part by enhancing endogenous GHRH release or actions. In addition, the distinctive ability of GHRH (but not estradiol) to increase basal (nonpulsatile) GH secretion, shift the GH acrophase and synchronize GH output patterns identifies certain divergent hypothalamo-pituitary actions of these two major GH secretagogues.

Congenital malaria due to Plasmodium falciparum.

Malaria manifested during the first few months of life may be result of acquisition during pregnancy, at the time of delivery, or by mosquito bite after birth. Both congenital and perinatal malaria are acquired by the transmission of parasitized maternal erythrocytes across the placenta. An infant is described whose mother was diagnosed to have malaria at six months of gestation. The infant developed intermittent fever at 5 weeks of age and presented with anemia and hepatosplenomegaly at 3 months of age at which time Plasmodium falciparum parasites were found on examination of thick smears of the infant's blood. IgG and IgM antimalarial antibodies were detected in maternal blood, but only IgG antibodies were found in the infant's blood at delivery and at the time of diagnosis. These transplacentally transmitted antibodies may afford transient protection for the infant and thus delay the onset of clinical manifestations. Due to the absence of an exoerythrocytic life cycle in congenitally acquired malaria, chloroquine is the drug of choice for treatment. Infections with chloroquine-resistant strains require multiple drug therapy.

Efficacy and safety of ampicillin/sulbactam and cefuroxime in the treatment of serious skin and skin structure infections in pediatric patients. UNASYN Pediatric Study Group.

BACKGROUND: Pediatric skin and skin structure infections are often polymicrobial and require empiric therapy effective against pathogens that may be resistant to many antimicrobial agents. The present study tested the efficacy and safety of a parenteral beta-lactam/beta-lactamase inhibitor combination, ampicillin/sulbactam, and a beta-lactamase-stable cephalosporin, cefuroxime, in serious pediatric skin and skin structure infections requiring hospitalization and parenteral antimicrobial therapy. METHODS: This was a multicenter, randomized, prospective, comparative open label trial that enrolled patients 3 months through 11 years of age. Patients received 150 to 300 mg/kg/day ampicillin/sulbactam in equally divided intravenous doses every 6 h. Cefuroxime was given in a dosage of 50 to 100 mg/kg/day either intravenously or intramuscularly in equally divided doses every 6 or 8 h. Maximum treatment was not to exceed 14 days. Patients could receive subsequent oral antimicrobial treatment at the investigator's discretion. RESULTS: At final evaluation for clinical efficacy, 78.0% (n = 46) of the 59 evaluable patients who received ampicillin/sulbactam were cured and 22.0% (n = 13) were improved. The respective values for the 39 evaluable patients treated with cefuroxime were 76.9% (n = 30) and 23.1% (n = 9). At the end of treatment all pathogens were eradicated from 93.2% (n = 55) of 59 patients treated with ampicillin/sulbactam and from 100% of 39 who received cefuroxime. There were no significant differences between treatments in clinical or bacteriologic efficacy. Both ampicillin/sulbactam and cefuroxime were well-tolerated. CONCLUSION: Both ampicillin/sulbactam and cefuroxime provide safe and effective parenteral antibiotic therapy in pediatric patients with serious skin and skin structure infections.

Randomized comparative study of ampicillin/sulbactam vs. ceftriaxone for treatment of soft tissue and skeletal infections in children.

In a prospective study 105 children hospitalized with soft tissue infection, 11 children with suppurative arthritis and 9 children with osteomyelitis were treated with either parenterally administered ampicillin/sulbactam or ceftriaxone. Treatment was randomized using a computer-generated table in a 2:1 fashion: 84 patients received ampicillin/sulbactam and 41 patients received ceftriaxone. Organisms isolated from wound site or blood cultures included Staphylococcus aureus (33), Streptococcus pyogenes (19), Haemophilus influenzae (9) including 4 beta-lactamase-positive organisms, Streptococcus pneumoniae (5), Neisseria gonorrhoeae (3) and 9 other organisms. Clinical and bacteriologic response was satisfactory in 100% of the ampicillin/sulbactam-treated patients and in 93% of the ceftriaxone-treated patients. Two patients with S. aureus infections treated with ceftriaxone had a delayed response and required change in therapy to parenterally administered oxacillin. Ampicillin/sulbactam represents a potentially useful single agent for the treatment of cellulitis and bone or joint infections in pediatric patients.

Malassezia furfur: a cause of occlusion of percutaneous central venous catheters in infants in the intensive care nursery.

Growth of Malassezia furfur in the intravascular catheter used for administration of lipid emulsion resulted in occlusion of deep intravascular Silastic catheters in 12 infants in 2 intensive care nurseries. At the time of occlusion visible growth was noted in the clear catheter which was connected to the Silastic intravascular line. Five infants showed clinical signs suggestive of sepsis. The yield of M. furfur from blood cultures and catheter tips was low even when oil enrichment was used. The highest yield of M. furfur was found in the connecting catheter (11 of 11). The source from and the route by which M. furfur entered the catheter remain unclear. The potential portals of entry include the proximal and distal ends of the connecting catheter as well as the colonized skin of the infants and caretakers.

Reliability of polymerase chain reaction in the detection of human immunodeficiency virus infection in children.

During a 3-year period we followed 128 human immunodeficiency virus (HIV) antibody-positive children ages 6 days to 11 years clinically and with an HIV diagnostic panel consisting of antibody (by enzyme-linked immunosorbent assay and confirmed by indirect fluorescence assay or Western blot), p24 antigen detection, HIV isolation from peripheral blood culture and molecular detection of HIV nucleic acids by polymerase chain reaction (PCR). The PCR procedure included 30 cycles of amplification using two separate gag primer pairs (SK38/39 and SK101/145), followed by detection with probes to areas amplified (SK19 and SK102). Results of PCR were available within 48 hours and were sensitive (97%) and specific (100%). PCR should be obtained on all children exposed perinatally, and aggressive management should be undertaken for those found to be positive.

Bloodstream infections in neonatal intensive care unit patients: results of a multicenter study.

For identification of risk factors for bloodstream infection (BSI) among neonatal intensive care unit patients, prospective 6-month studies in three neonatal intensive care units were conducted. BSI was diagnosed in 42 of 376 (11.2%) enrolled infants. Pathogens included coagulase-negative staphylococci, Candida sp., Group B streptococci and Gram-negative species. Patients with BSIs were more likely to die during their neonatal intensive care unit stay than were patients who did not acquire BSIs (6 of 42 vs. 11 of 334, P = 0.007). BSI rate was highest in infants with birth weight < 1500 g (relative risk (RR) = 6.8, P < 0.001), those treated with H-2 blockers (RR = 4.2, P < 0.001) or theophylline (RR = 2.8, P < 0.001) and those with admission diagnoses referable to the respiratory tract (RR = 3.7, P < 0.001). Infants who developed BSI were more severely ill on admission than other infants (median physiologic stability index 13 vs. 10 (P < 0.001) and were of lower gestational age (28 vs. 35 weeks, P < 0.001). In logistic regression analysis, risk of BSI was independently associated only with very low birth weight, respiratory admission diagnoses and receipt of H-2 blockers. Risk of isolation of a pathogen from blood culture was independently associated with Broviac, umbilical vein or peripheral venous catheterization > 10, 7 or 3 days, respectively, at one insertion site. Rate of isolation of a pathogen was higher (9 of 59 (15%)) within 48 hours of a measurable serum interleukin 6 concentration than an interleukin 6 level of 0 pg/ml (10 of 159 (6%), P = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Linezolid for the treatment of community-acquired pneumonia in hospitalized children. Linezolid Pediatric Pneumonia Study Group.

OBJECTIVE: To determine the safety, tolerance, pharmacokinetics and efficacy of linezolid, a new oxazolidinone antibiotic in the treatment of community-acquired pneumonia in hospitalized children. DESIGN: A Phase II, open label multicenter study of intravenous linezolid followed by oral linezolid suspension, both at a dose of 10 mg/kg every 12 h. Efficacy was assessed at 7 to 14 days after the last dose of linezolid. PATIENTS: Children 12 months to 17 years old with community-acquired pneumonia admitted to the hospital of 14 participating centers. RESULTS: From July 21, 1998, through May 14, 1999, 79 children were enrolled and 78 received linezolid. Sixty-six children completed treatment and follow-up and were evaluable for clinical outcome. The median age of the evaluable patients was 3 years (range, 1 to 12 years); 47 were 2 to 6 years old. Pathogens were isolated from blood or pleural fluid cultures in 8 children: Streptococcus pneumoniae, 6 (2 penicillin-resistant); Group A Streptococcus, 1; methicillin-resistant Staphylococcus aureus, 1. Chest tubes were placed in 9 patients. The mean total duration of intravenous and oral administration was 12.2 +/- 6.2 days (range, 6 to 41 days). The mean peak and trough plasma concentrations of linezolid were 9.5 +/- 4.8 and 0.8 +/- 1.2 microg/ml, respectively. At the follow-up visit 7 to 14 days after the last dose of linezolid, 61 patients (92.4%) were considered cured including all the patients with proven pneumococcal pneumonia, one failed (methicillin-resistant Staphylococcus aureus) and 4 were considered indeterminate. The most common adverse effects in the intent to treat group were diarrhea (10.3%), neutropenia (6.4%) and elevation in alanine aminotransferase (6.4%). CONCLUSIONS: Linezolid was well-tolerated and could be considered an alternative to vancomycin for treating serious infections caused by antibiotic-resistant Gram-positive cocci in children pending results of additional studies.

Listeria monocytogens: synergistic effects of ampicillin and gentamicin.

Listeria monocytogenes infections are most common in newborn infants and persons with impaired defense mechanisms. There are reports of successful treatment with ampicillin alone: however, there is uncertainty as to what regimen constitutes the most effective therapy. The purpose of this study was to illustrate the in-vitro synergism between ampicillin and gentamicin against L. monocytogenes. Seven strains of L. monocytogenes isolated from bloods or cerebrospinal fluids of infants and three control strains obtained from the Center for Disease Control were tested. Minimal inhibitory concentrations of ampicillin and gentamicin were determined in Todd-Hewitt broth with an inoculum of 10(5) organisms/ml. Killing curves were determined for ampicillin 6 microgram/ml, gentamicin, 0.5 microgram/ml, and the combination of ampicillin, 6 microgram/ml, plus gentamicin, 0.5 microgram/ml. Incubation of approximately 10(7) organisms/ml with these concentrations of ampicillin and gentamicin caused no significant reduction in the viable bacterial population in 24 hours. The combination, on the other hand, was bactericidal in all seven strains isolated from patients and one control strain. The authors believe the ultimate test of the superiority of this combination to ampicillin alone must come from clinical studies. However, the synergistic and bactericidal effects of ampicillin with gentamicin may be very desirable in treatment of newborns and patients with underlying disease.

Cerebral cysticercosis in a 22-month-old infant.

A case of cerebral cysticercosis is described in a 22-month-old infant from northern California who presented with a right-sided focal seizure. Unusual features were her young age; a single, enlarging, frontoparietal mass lesion; and apparent lack of history of exposure to an endemic area.

Esophagitis associated with Candida infection in a neonate.

A 14-day old infant with stomatitis due to Candida albicans presented with frequent emesis and was found to have esophagitis by barium esophagram. She responded promptly to oral Mycostatin suspension: her emesis subsided and the stomatitis resolved. Repeat esophagram on the seventh day of therapy showed complete resolution of the esophageal mucosal abnormalities. Although Candida stomatitis is common in infants, the incidence and appropriate therapy of Candida esophagitis as a complication in otherwise normal infants are unknown. This patient responded well to frequent therapy with an oral, nonabsorbable antifungal agent.

Hemodynamic factors affecting the suitability of the donated heart and kidney for transplantation.

BACKGROUND: Due to the loss of autonomic nervous system, precise control of the hemodynamic status in dead brain potential donors presents a clinical dilemma. In these patients, due to head trauma and cerebral edema, fluids administration is restricted. Moreover, the decreased central venous pressure may put the viability of the organs at risk. OBJECTIVE: To investigate hemodynamic factors affecting the suitability of the donated heart and kidney for transplantation. METHODS: Data were retrospectively collected from the maintained databases of all dead-brain donors (DBDs) admitted to our organ procurement unit (OPU) ICU between 1999 and 2008. In this study, laboratory variables in addition to demographic data were collected. The time between donor entrance to the DBD ICU and organ procurement, vital signs, hourly urine output, amount of IV fluid administered, and the dosage of vasopressor and desmopressin were recorded. The end-point of the study was organ suitability for organ retrieval. RESULTS: A total of 132 dead brain donors were studied. The mean±SD age of the donors was 26.3±12.2 years. The main cause of brain death was multiple trauma (53%). The organ retrieval rate was 82.6% for the kidney, 59.8% for the liver, and 53% for the heart. 83 (63%) and 106 (80.3%) donors had suitable hearts and kidneys, respectively. 66 cases did not receive desmopressin (50.4%) at all. The mean±SD dose of desmopressin the donors received was 7±1 µg. There was a significant association between the suitability of these two organs for transplantation and the dosage of the administered desmopressin and volume of IV solution the donors received. CONCLUSION: Fluid therapy and administration of desmopressin can improve the number and quality of retrieved organs from dead brain donors.

Hepatocytes of donor origin in recipient liver after hematopoietic SCT in beta-thalassemia major patients.

BM and circulating cells contain stem cells with the potential to differentiate into mature cells of various organs. We determined whether stem cells transformed into hepatocytes. Biopsy specimens from liver were obtained from 11 patients who had undergone transplantation of hematopoietic stem cells from peripheral blood (eight patients) or BM (three patients). Four female patients had received transplants from a male donor and seven male patients had received transplants from a female donor. All patients had beta-thalassemia major and fibrosis in biopsy specimens from the liver before hematopoietic SCT. Hematopoietic stem cell engraftment was verified by STR analysis. The biopsies were studied for the presence of donor-derived hepatocytes using FISH of interphase nuclei and immunohistochemical staining for CD45 (leukocyte common Ag), and a hepatocyte-specific Ag. All 11 recipients of sex-mismatched transplants showed evidence of complete hematopoietic donor chimerism. XY-positive hepatocytes accounted for 4-6.7% of cells in histological sections of the biopsy specimens of female patients and XX-positive hepatocytes accounted for 3-7% of cells in histological sections of the biopsy specimens of male patients. These cells were detected in liver tissue as early as 1 year and as late as 8.5 years after hematopoietic SCT. BM and circulating stem cells can differentiate into mature hepatocytes in beta-thalassemia major patients who had undergone hematopoietic SCT.