Biomedical subjects

V M Gonçalves

Publications and source records attributed to V M Gonçalves.

16 recordsLinked to original sources

PubMed2006

Introduction of air in the anaerobic culture of Streptococcus pneumoniae serotype 23F induces the release of capsular polysaccharide from bacterial surface into the cultivation medium.

AIM: An approach to increase Streptococcus pneumoniae capsular polysaccharide (CPS) in the culture medium during fed-batch cultivation in bioreactor. METHODS AND RESULTS: Streptococcus pneumoniae serotype 23F was cultivated in a 5-l bioreactor with nitrogen-sparging and followed by addition of air in the stationary phase. The amount of CPS released in the supernatant progressively increased under air sparging. The profile of cellular viability and optical density was similar in both cultures. Immunoelectron microscopy showed that the amount of tightly cell-bound CPS was higher in bacteria cultivated under nitrogen than under air. CONCLUSIONS: The stress caused by the addition of air at the stationary phase promoted a large increase of free CPS into the medium, as a consequence of the morphologic change in the capsule. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of air in the stationary phase of the culture would greatly simplify the subsequent downstream process, allowing CPS purification from the supernatant. The direct consequence of this process improvement is the reduction of vaccine production costs.

Air↗

PubMed2002

Optimization of medium and cultivation conditions for capsular polysaccharide production by Streptococcus pneumoniae serotype 23F.

The influence of medium composition and culture conditions on Streptococcus pneumoniae serotype 23F cultivation was investigated in order to develop an industrial method for polysaccharide (PS) production. Acid-hydrolyzed casein (AHC) and dialyzed enzymatically hydrolyzed soybean meal (EHS) were investigated as nitrogen sources, and the vitamin solution of Hoeprich's medium and dialyzed yeast extract as vitamin sources. The influence of initial glucose concentration was also evaluated. In flask experiments, the best nitrogen source for PS production was AHC; EHS yielded small amounts of PS without interfering with bacterial growth. Dialyzed yeast extract provided an approximately 2-fold increase in PS production when compared to Hoeprich's vitamin solution. In a 5-l bioreactor, it was observed that the pneumococcus did not grow under aerobic conditions, CO(2) did not increase PS yield, glucose was inhibitory above 30 g l(-1), and the main glucose catabolism product was lactate, which had an inhibitory effect on cell growth. When anaerobic cultivation was performed under N(2) flow using the optimized medium, 240 mg l(-1) of soluble PS was obtained, which represents a 3-fold increase in yield as compared to that described in the published patent [Yavordios and Cousin (1983) European Patent 0 071515 A1]. Application of these results would considerably simplify upstream and downstream processes for PS production.

Bioreactors↗

PubMed2001

Hemiparetic cerebral palsy: etiological risk factors and neuroimaging.

The purpose of this paper, which was conducted on 175 children with hemiparetic cerebral palsy (H-CP), was to verify the etiological risk period for this disease. Etiological risk factors (ERF) were detected through anamnesis: 23% in the prenatal period, 18% in the perinatal period and 59% of the patients the period was undefined (ERF in the prenatal and perinatal period was 41% and no ERF was 18% of the cases. The computerized tomographic scan (CT) and MRI were performed on all the patients, who were then classified according to their etiopathogenic data: CT1= normal (18%); CT 2= unilateral ventricular enlargement (25%); CT 3= cortical/ subcortical cavities (28%); CT4= hemispheric atrophy and other findings (14%); CT 5= malformations (15%). CT 5 was associated with physical malformations beyond the central nervous system and with prenatal ERF's, while CT 2 was associated with the perinatal ERF's, mainly in premature births. Magnetic resonance imaging was performed on 57 patients and demonstrated a good degree of concordance with the CT. Etiology remained undefined in only 37% of the cases after neuroimaging was related to ERF. A high perinatal RF frequency (59%) was observed and emphasized the need for special care during this period.

Cerebral Palsy↗

PubMed2000

Epidemiology of bloodstream infections at a cancer center.

CONTEXT: Cancer patients are at unusually high risk for developing bloodstream infections (BSI), which are a major cause of in-hospital morbidity and mortality. OBJECTIVE: To describe the epidemiological characteristics and the etiology of BSI in cancer patients. DESIGN: Descriptive study. SETTING: Terciary Oncology Care Center. PARTICIPANTS: During a 24-month period all hospitalized patients with clinically significant BSI were evaluated in relation to several clinical and demographic factors. RESULTS: The study enrolled 435 episodes of BSI (349 patients). The majority of the episodes occurred among non-neutropenic patients (58.6%) and in those younger than 40 years (58.2%). There was a higher occurrence of unimicrobial infections (74.9%), nosocomial episodes (68.3%) and of those of undetermined origin (52.8%). Central venous catheters (CVC) were present in 63.2% of the episodes. Overall, the commonest isolates from blood in patients with hematology diseases and solid tumors were staphylococci (32% and 34.7%, respectively). There were 70 episodes of fungemia with a predominance of Candida albicans organisms (50.6%). Fungi were identified in 52.5% of persistent BSI and in 91.4% of patients with CVC. Gram-negative bacilli prompted the CVC removal in 45.5% of the episodes. Oxacillin resistance was detected in 26.3% of Staphylococcus aureus isolates and in 61.8% of coagulase-negative Staphylococcus. Vancomycin-resistant enterococci were not observed. Initial empirical antimicrobial therapy was considered appropriate in 60.5% of the cases. CONCLUSION: The identification of the microbiology profile of BSI and the recognition of possible risk factors in high-risk cancer patients may help in planning and conducting more effective infection control and preventive measures, and may also allow further analytical studies for reducing severe infectious complications in such groups of patients.

Adolescent↗

PubMed2000

Albumin purification from human placenta.

Albumin is the human protein used mainly for therapeutic purposes. Besides the traditionally used plasma, blood from placenta is an alternative source for albumin purification. We describe here an industrial process for purification of albumin from human placenta. The proposed albumin-purification process, for 50 kg of placentas, comprises: (i) extraction of haemolysed blood with saline and solid/liquid separation by basket centrifugation; (ii) selective precipitation of haemoglobin by ethanol/chloroform and precipitate removal by filtration in a press filter; (iii) concentration/diafiltration of the filtrate in a 30 kDa cross-flow ultrafiltration (CFUF) membrane; (iv) thermo-coagulation at 70 degrees C with sodium octanoate/EDTA; (v) treatment with activated charcoal at pH 3; (vi) concentration/diafiltration of the filtrate in a 30 kDa CFUF membrane; (vii) anion-exchange chromatography Q-Sepharose; (viii) hydrophobic-interaction chromatography with phenyl-Sepharose; and (ix) conditioning and pasteurization. The process yields an average of 4.5 g of albumin/kg of placenta with a purity of 97.1% and A(403) of 0.05 (1% protein). The final product passes pyrogen and toxicity tests in vivo and it does not contain polymers or aggregates, even after the accelerated stability test, as judged by gel filtration, as required by the Brazilian Pharmacopoeia.

Biotechnology↗

PubMed2000

[Neurologic semiology of a group of first grade students in an elementary school].

We evaluated children in the first grade of a elementary school using neurological examination. With no previous knowledge of their educational performance, were invited all children attending five classes of the first grade of an elementary public school chosen randomly, in Itatiba / Sao Paulo / Brazil, whose parents assigned a Commitment Term for participation in this research. Children who missed three evaluations in different days or whose parents did not assigned the Commitment Term were excluded. The Traditional Neurological Examination (ENT) (Lefevre, 1972) was applied. It was considered for normal the measurement of the skull circumference, proposed by Diament & Rodrigues (1976), and the application of all ENT items. The data were stored in a database of the Epi6 Program (Epidemiologic Information), and analyzed by percentage calculation and by the chi2 test. The significance level was 0.05. Children evaluated were 124. The ENT results were normal in 87 (70.16%) and altered in 37 (29.83%). Among the alterations, there were observed: light tremor, light muscular hypotonia, speech acquisition delay, macrocephaly, microcephaly, hyperactivity, cranial nerve syndrome, central facial paralysis. One child presented corticospinal tract impairment syndrome of the distal lower extremities.

Brazil↗

PubMed1999

Crystallization and preliminary X-ray diffraction studies of human catalase.

The enzyme catalase (H(2)O(2)-H(2)O(2) oxidoredutase; E.C. 11.1.6) was purified from haemolysate of human placenta and crystallized using the vapour-diffusion technique. Synchrotron-radiation diffraction data have been collected to 1.76 A resolution. The enzyme crystallized in the space group P2(1)2(1)2(1), with unit-cell dimensions a = 83.6, b = 139.4, c = 227.5 A. A molecular-replacement solution of the structure has been obtained using beef liver catalase (PDB code 4blc) as a search model.

Catalase↗

PubMed1998

Risk factors for bloodstream infections at a cancer center.

A hospital-based matched case-control study was conducted in order to identify risk factors for the development of bloodstream infections in adult hospitalized patients. Between January 1993 and December 1994, 264 episodes of bloodstream infection were evaluated. Significant variables identified by univariate analysis were included in a multivariate model that showed that central venous catheter [odds ratio (OR), 6.71], poor performance status (OR, 3.40), weight loss (OR, 2.47), hematologic diseases (OR, 2.24), and previous antimicrobial therapy (OR, 2.12) independently influenced the outcome. The knowledge of modifiable risk factors is useful in the development of strategies that may contribute to the prevention of bloodstream infections.

Adolescent↗

PubMed1998

Risk index for prediction of surgical site infection after oncology operations.

INTRODUCTION: Several studies have shown that surgical site infections represent most hospital-acquired infections, with the major impact being on average hospital stay and cost of hospitalization. METHODS: To develop a risk model for prediction of surgical site infections in cancer patients undergoing operative procedures and identify those with high probability of infection we performed a prospective cohort study in a tertiary cancer care hospital in Rio de Janeiro, Brazil. Risk factors were studied in single and multivariate analyses. RESULTS: Over a 24-month period, 1205 patients underwent operations for malignant disease. The overall surgical site infection rate was 17.3%. A multivariate stepwise logistic regression model identified six independent predictive risk factors: contaminated and infected operations, surgical duration greater than 280 minutes, male sex, prior radiotherapy, American Society of Anesthesiology class III to V, and antimicrobial prophylaxis not according to protocol. On the basis of individual risk scores, two groups of patients were identified: a low-risk (score < or = 8; surgical site infection rate 10%) and a high-risk group (score > or = 9; surgical site infection rate 33.6%; relative risk 3.4; 95% confidence interval 2.6 to 4.4). CONCLUSION: The oncology risk model allowed for the identification of a high-risk score group of patients and implementation of a more efficient and selective intervention program.

Brazil↗

PubMed1998

An outbreak of Bacillus species in a cancer hospital.

Bacillus species were recovered from the blood cultures of 39 oncology patients over 14 weeks. A matched case-control study showed a strong association of Bacillus species bacteremia with use of calcium gluconate solution (odds ratio=25.0) and of central venous lines (odds ratio=8.8). Stopping use of the implicated calcium gluconate vials controlled the outbreak.

Adolescent↗

PubMed1997

Nosocomial infections in an oncology intensive care unit.

INTRODUCTION: Treatment of cancer has contributed to a growing number of immunocompromised patients with life-threatening nosocomial infections (NI). High mortality with considerable cost is observed when they are admitted to the intensive care unit (ICU). Few studies on infection control and surveillance have been undertaken in this population group. METHODS: All patients treated at a six-bed medical-surgical oncology ICU for > 48 hours were prospectively observed for the development of an NI and the influence of device utilization on infection rates. The analysis used the standard definitions of the National Nosocomial Infection Surveillance System Intensive Care Unit surveillance component. RESULTS: From September 1993 through November 1995, 370 infections occurred in 623 patients during 4034 patient-days, for an overall rate of 50.0 per 100 patients or 91.7 per 1000 patient-days. Pneumonia (28.9%), urinary tract infections (25.6%), and bloodstream infections (24.1%) were the main types of infection. The most common microorganisms isolated were Enterobacteriaceae (29.7%), fungi (22.2%), and Pseudomonas aeruginosa (13.2%). The median device utilization ratios were 0.63, 0.83, and 0.86 for ventilator, indwelling urinary catheter, and central venous catheter, respectively. The highest median device-specific associated infection rate was 41.7 for ventilator. The median for the average length of stay was 8.8 days, and the average severity of illness score was 4.0. There was a strong positive correlation between the overall NI patient rate and device utilization (r = 0.56, p < 0.01), average severity of illness score (r = 0.54, p < 0.01), and average length of stay (r = 0.67, p < 0.01). No correlations were statistically significant when patient-days were used in the denominator. Among the devices only the number of central venous catheter days was significantly correlated with infections (r = 0.51, p = 0.01). The NI patient-day rates were progressively higher the longer the patients stayed in the ICU. CONCLUSIONS: The high rates reported in this study may reflect a combination of several factors related to the underlying illness, neutrophil count, and exposure to invasive procedures. The adjusted infection rates described here provide specific surveillance data for further interhospital comparisons and also to assess the influence of invasive medical interventions, allowing the implementation of preventable measures to control infections.

Brazil↗

PubMed1994

[Discitis in children. Study of 8 cases].

The authors report the study of eight children with discitis diagnosed through clinical, neurological and orthopedic evaluation. The evidence of self limiting inflammation or infection of the intervertebral disk space and of soft tissue were available by image studies. Findings with routine roentgenograms, computed tomography and magnetic resonance imaging are discussed.

Adolescent↗

PubMed1993

[Neurologic semiology in a population of hearing impaired children].

A random sample of 42 sensorineural hearing impaired children (severe and bilateral) was studied, from special classes in Campinas, with chronological ages varying between 4 and 7 years old. The children of this sample were compared with two control groups of 42 children of the same chronological age, from regular classes of private and public schools. All of them were submitted to the traditional neurological examination. Hearing impaired children showed differences as to head circumference and muscle tonus. In the other examined items we found motor hyperactivity, cerebellar and ocular syndromes although there were no significant differences between the groups.

Age Factors↗

PubMed1993

[Evaluation of the static equilibrium in a population of hearing impaired children].

A random sample was organized with 42 children with congenital sensorineural auditory deficit (severe and bilateral) from special education schools in Campinas. Chronological ages ranged from 4 to 7 years of age. This sample was compared with two control groups of 42 children of the same chronological age but attending normal classes. All were submitted to 9 tests of the set of static equilibrium of the Evolutive Neurologic Examination. It was observed that in the position of equilibrium with opened eyes (test 8) there were no differences between the groups. In the Romberg position, the hearing impaired children of 4, 5 and 6 years of age showed a significant decrease in the ability to do the test (test 9); those of 7 years of age had equal ability whether of the control or the deficient groups. Hearing impaired children were less able to do other static equilibrium tests (heel-toe or one foot or tip-toe standing tests, with opened or closed eyes: tests 10, 12, 16, 20, 24, 25 and 26). The use of detailed neurological semiology allowed us to support the alteration of the static equilibrium in this group of hearing impaired children.

Child↗

PubMedDate not supplied

[Risk factors for surgical wound infection development in head and neck cancer surgery].

Over a period of 24 months, patients undergoing surgical procedures for head and neck cancer at the Cancer Hospital in Rio de Janeiro, Brazil were followed-up prospectively for identification of surgical wound risk factors. A total of 273 patients fulfilling the National Nosocomial Infection Surveillance (NNIS) surgical criteria completed the analysis. The overall wound infection rate was 25.3%. Of the 11 potential risk factors for postoperative wound infections analysed by stepwise multiple logistic regression, the five variables that were independent of each other and highly predictive were patient undergoing an operation classified as either contaminated or infected, a surgery lasting longer than 5 hours, an American Society of Anesthesiologist (ASA) preoperative assessment score of 4 and 5, age over 50 years and prior radiotherapy. The preoperative stay, antibiotic prophylaxis, surgical drains, preoperative nutritional status, sex and the presence of prior infection did not have an independent significant contribution to the risk of infection. This study reports specific risk factors for head and neck cancer surgeries and contributes substantially to the effectiveness of infection control strategies to prevent their occurrence in this high-risk group of patients.

Adolescent↗

PubMedDate not supplied

[Antibiotic prophylaxis in oncologic surgery].

Perioperative antibiotic administration can decrease surgical morbidity, shorten hospitalization, while lowering the overall costs attributable to infections. Its use in surgery is widespread and often inappropriate. In this study, the authors evaluate the guidelines for selection and use of prophylactic antibiotics in surgical cancer patients at the Hospital of Cancer in Rio de Janeiro, Brazil. During 36 non-consecutive months, 1681 cancer patients submitted to surgical procedures were prospectively followed-up by members of the Hospital Infection Control Committee. The overall surgical site infection (SSI) and mortality rates were 17.7% and 4.8% respectively. Prophylactic antibiotics were used in 1262 elective surgeries (75.1%), and their use was not considered to be in accordance with the recommended protocol in 37.6% of the cases. The inadequate antimicrobial prophylaxis resulted in higher incidence of SSI than did prophylaxis in according to the protocol (21.7% vs. 16.4, Relative Risk 1.32; 95% Confidence Internal 1.05-1.67; p0.01). This study calls the attention for the need of a more strict and determined educational program in order to provide mechanisms for an adequate administration of prophylactic antibiotics to patients submitted to high-risk surgeries.

Adolescent↗