Muscular force is reduced in neurofibromatosis type 1.

OBJECTIVES: To measure muscular force in neurofibromatosis type 1 (NF1) patients. METHODS: The maximal voluntary muscular force (F(max)) was measured in the first 21 volunteer patients without acute health problems at the routine annual examination in the Neurofibromatosis Outpatient Reference Center during October-November (2007). The NF1 individuals were 9 males and 12 females, aged from 7 to 60 years and physically sedentary. The healthy control group was 21 healthy subjects matched to NF1 group by age, sex and physical activity. A handgrip test instrument was used to measure maximal force. To allow comparisons between physically different patients, forearm circumference (cm) was measured with a tape and forearm cross sectional area was derived to express the force per unit of forearm area. Data were compared using a t Student test (P<0.05). RESULTS: The mean F(max) of NF1 male (260-/+136 N) and NF1 female (217-/+76 N) were lower than expected for their sex and age. Healthy men showed greater F(area) (9.8-/+3.2 N x cm(-2)) than NF1 men (5.7-/+2.6 N x cm(-2)) and healthy women (6.7-/+1.6 N x cm(-2)) showed greater F(area) than NF1 females (5.7-/+1.9 N x cm(-2)). CONCLUSION: Maximal voluntary muscle force was reduced in NF1 patients.

Efficacy of antivenom therapy for neutralizing circulating venom antigens in patients stung by Tityus serrulatus scorpions.

Enzyme-linked immunosorbent assays for detection of Tityus serrulatus venom antigen and of horse anti-T. serrulatus venom antibodies were carried out before antivenom treatment and at 1, 6, 12, and 24 hr after antivenom therapy in 18 patients with systemic manifestations following T. serrulatus scorpion sting. Increased levels of circulating venom antigens were detected in the patients before antivenom treatment, but were no longer detected 1 hr after specific antivenom therapy. High titers of antivenom persisted for at least 24 hr after treatment with antivenom. The evolution of clinical and laboratory manifestations of envenoming showed that vomiting and local pain decreased within 1 hr and hyperglycemia was no longer detected 12 hr after antivenom therapy. The cardiorespiratory manifestations disappeared 6-24 hr after the administration of antivenom and all patients recovered completely. This study demonstrates the efficacy of antivenom therapy in neutralizing circulating venom antigens and supports the prompt administration of a potent antivenom to patients with systemic manifestations of envenoming.

Coagulopathy following lethal and non-lethal envenoming of humans by the South American rattlesnake (Crotalus durissus) in Brazil.

The South American tropical rattlesnake (Crotalus durissus subspp) is responsible for approximately 10% of bites from venomous snakes in Brazil. We studied 24 victims of bites by this species over 3 years, in south-eastern Brazil, particularly investigating haemostatic alterations. Thirteen patients were defined as moderately envenomed and 11 as severe. There were two deaths, which were not attributed to venom-induced haemostatic disturbances. However, envenoming by C. durissus is frequently associated with haemostatic disorders, which are probably attributable mainly to the action of the thrombin-like enzyme, with possible additional effects secondary to the powerful myotoxic activity of the venom.

Immunotherapy for scorpion envenoming in Brazil.

Using the ELISA we have shown that in rats subcutaneously injected with Tityus serrulatus scorpion venom there is a fast absorption rate, a fast and high distribution of venom to tissues, a great affinity of the venom for the tissues and a slow elimination half-life. Because of these experimental data, i.v. immunotherapy should be given to patients stung by scorpions as soon as possible after hospital admission. The severity of scorpion envenoming is related to plasma venom concentration (ELISA). The high levels of plasma scorpion venom antigens (ELISA) were cleared 1 h after the infusion of antivenom (5-30 ml of Fab2 fragment) and high concentrations of circulating antivenom persisted for at least 24 h, confirming the efficacy of immunotherapy to neutralise circulating venom. Some symptoms (e.g. local pain and vomiting) decreased 1 h after the starting of immunotherapy, whereas the other symptoms disappeared from 12-48 h later. Using our tripartite approach of treating scorpion envenoming (symptomatic measures, support of vital functions and serotherapy), the mortality rate was very low (0.28%).

Is the severity of Tityus serrulatus scorpion envenoming related to plasma venom concentrations?

Plasma venom concentrations were measured by enzyme-linked immunosorbent assay at the time of hospital admission in 56 patients stung by the scorpion Tityus serrulatus. According to clinical and laboratory manifestations patients were classified into two groups: patients with only local pain at the site of the sting (n = 37), and patients with systemic manifestations of envenoming (n = 19). Circulating venom concentrations of these two groups of patients were cross-tabulated and the results showed that patients with systemic manifestations of envenoming had significantly higher plasma venom concentrations than patients with only local pain at the site of the sting.

Children with adrenergic manifestations of envenomation after Tityus serrulatus scorpion sting are protected from early anaphylactic antivenom reactions.

The incidence of early anaphylactic reactions to scorpion antivenom given i.v. after Tityus serrulatus scorpion sting was evaluated in 103 children aged up to 15 years in Belo Horizonte, Brazil. Patients without adrenergic manifestations (Group 1, n = 28) were compared with those who presented systemic involvement that included adrenergic manifestations (Group 2, n = 75). Data were recorded on a proforma and the presence or absence of early anaphylactic reaction was cross-tabulated according to clinical features, sex, age and volume of antivenom used in the treatment. Unpaired Student's t-test was used to calculate significance of differences in age and volume of antivenom used. Multivariate logistic regression was used to determine the effects of clinical features and volume of antivenom as predictors of early anaphylactic reaction to antivenom treatment. Twelve (42.9%) of 28 children included in Group 1 presented early anaphylactic reactions compared with 6 (8%) of 75 children of Group 2 (OR = 8.63; 95% CI: 2.88, 25.7). The reactions were more severe in Group 1. There were no significant differences with respect to age and sex. After adjusting for clinical form, volume of antivenom was not significantly associated with presence of reactions (OR = 1.11; 95% CI: 0.70, 2.80 for each 5.0 ml of antivenom administered). The results show that children with adrenergic manifestations after T. serrulatus scorpion sting had significantly lower anaphylactic reactions to antivenom than those without these manifestations.

Scorpion sting-induced pulmonary oedema: evidence of increased alveolocapillary membrane permeability.

A 16-year-old boy died with acute pulmonary oedema and shock after Tityus serrulatus scorpion sting. The patient showed evidence of cardiac dysfunction and damage, an increase in tracheobronchial aspirate/plasma protein concentration, light microscopic features of the lung compatible with the adult respiratory distress syndrome and electron microscopic findings compatible with acute lung injury and increased alveolocapillary membrane permeability.

Tourniquet ineffectiveness to reduce the severity of envenoming after Crotalus durissus snake bite in Belo Horizonte, Minas Gerais, Brazil.

Clinical and laboratory data from patients who applied a tourniquet (tourniquet group, n = 45) and who did not apply it (non-tourniquet group, n = 52) after being bitten by Crotalus durissus were compared. The patients were treated with 100-200 ml of Crotalus durissus antivenom. The gender, age, time elapsed between bite and hospital admission, dose of antivenom and the frequency of local paresthesia, myalgia and palpebral ptosis did not differ between the two groups. Plasma creatine kinase enzyme activity and partial thromboplastin time, plasma whole venom and crotoxin concentrations and the frequency of acute renal and respiratory failure and number of deaths also did not differ between both groups. Data from this study show the ineffectiveness of tourniquet applied by patients in the fields to reduce the severity of Crotalus durissus envenoming.

Time factor in the detection of circulating whole venom and crotoxin and efficacy of antivenom therapy in patients envenomed by Crotalus durissus.

Thirty-seven patients envenomed by Crotalus durissus were classified into three groups according to the interval between the bite and hospital admission (delta T): group 1 (n = 14, delta T < 4 hr), group 2 (n = 14, delta T > 4 hr < 8 hr) and group 3 (n = 9, delta T > 8 hr). Venous blood from these patients was sampled for biochemical and hematological analysis and for whole venom, crotoxin and antivenom enzyme-linked immunosorbent assays before antivenom treatment (T0) and at 1 hr (T1), 6 hr (T6), 12 hr (T12) and 24 hr (T24) after the start of antivenom therapy. The patients were treated with 100-200 ml (10-20 ampules) of C. durissus antivenom. Whole venom and crotoxin were detected in 13 (92.8%) and 11 (78.6%) of 14 group 1 patients, respectively, in 11 (78.6%) and six (42.9%) of 14 group 2 patients, respectively, and in two (22.2%) and one (11.1%) of nine group 3 patients, respectively, before antivenom treatment. Data from this study show that whole venom and crotoxin were not detected in most of patients when the time elapsed between the bite and hospital admission was greater than 8 hr, and crotoxin was not detected in most of the patients who were admitted to the hospital at times ranging from 4 to 8 hr after the snakebite. Plasma whole venom, crotoxin and antivenom levels measured over time in these patients show the efficacy of antivenom treatment, since circulating venom and crotoxin were no longer detected 1 hr after antivenom therapy and high antivenom titers persisted for at least 24 hr after serotherapy.

South American rattlesnake bite (Crotalus durissus SP) without envenoming: insights on diagnosis and treatment.

A South American rattlesnake bite without clinical manifestations of envenoming (termed 'dry-bite') has not been recognized to occur by the Brazilian Ministry of Health, which recommends the administration of antivenom to all bitten patients. During 36 months of an observational study on South American rattlesnake bites in Minas Gerais, Brazil, 12% of 41 patients with fang marks at the bite-site did not present clinical or laboratory features of envenoming and had no plasma venom detected before specific serotherapy, fulfilling the criteria for the diagnosis of true 'dry-bite'. Data from these preliminary observations suggest that these patients should be correctly diagnosed since they should not be treated with unnecessary and sometimes hazardous and expensive serotherapy.

An enzyme-linked immunosorbent assay (ELISA) that discriminates between the venoms of Brazilian Bothrops species and Crotalus durissus.

Enzyme-linked immunosorbent assays (ELISAs) were developed to detect specific antigens from Bothrops sp. and Crotalus durissus snake venoms in Brazil. Cross-reactive immunoglobulins from hyperimmune horse anti-Bothrops and anti-Crotalus sera were removed by immunoaffinity chromatography. Specific IgGs for Bothrops sp. and C. durissus venom antigens were prepared and used to set up a sandwich-type ELISA. The specificity of the assay was demonstrated by its capacity to identify correctly the circulating antigens in mice experimentally inoculated with both venoms. Measurable absorbance signals were obtained with 5 ng of venom per assay. The ELISA was also used to identify circulating antigens in the sera of humans bitten by Bothrops sp. and C. durissus. These ELISAs could be valuable for clinicians and epidemiologists if they prove to have both the high sensitivity and specificity required for such tests.

Serum levels of cytokines in patients envenomed by Tityus serrulatus scorpion sting.

Seventeen patients stung by Tityus serrulatus scorpion were classified as mild (pain at the site of the sting, n = 6), moderate (local pain and one of the following manifestations: vomiting, psychomotor agitation, prostration, sweating, tachypnea, tachycardia and mild arterial hypertension, n = 10) and severe cases (equal moderate cases plus cardiac failure, pulmonary edema and shock, n = 1). Venous blood was sampled for biochemical and hematological analysis and for IL-1alpha, IL-6, IL-10, TNF-alpha, IFN-gamma and GM-CSF ELISAs at the time of hospital admission, 6 h (moderate and severe cases), and 12, 18, 36 and 72 h (severe case) later. Ten age-matched healthy volunteers were used as control. Increased serum levels of IL-1alpha was noticed in all patients, high levels of IL-6, IFN-gamma and GM-CSF were observed only in a patient with severe envenomation. Our data suggest that a systemic inflammatory response-like syndrome is triggered during severe envenomation caused by T. serrulatus sting and that release of cytokines may be involved in this response.

Functional and histopathological renal changes induced in rats by Bothrops jararaca venom.

1. Ninety-eight adult female rats were injected with 14 micrograms/g B. jararaca venom intraperitoneally to determine functional and histopathological renal changes. 2. Glomerular filtration rate, renal plasma flow, filtration fraction, osmolar clearance, water transportation in collecting ducts, urinary sodium excretion, fractional sodium excretion, albuminuria, urinalysis, plasma creatinine, urinary output and mean arterial pressure were studied before and 24 and 48 h after venom administration. Light microscope examination of the kidneys was carried out in another group of rats before and 2, 5 and 24 h after venom administration. 3. Treated animals developed acute renal failure characterized by a decrease in glomerular filtration rate, osmolar clearance, and fractional and urinary sodium excretion, and by an increase in plasma creatinine. There was also a decrease in renal plasma flow and mean arterial pressure. Histopathological examination of the kidneys indicated mild proliferation of the mesangial matrix and degenerative changes of the tubules characterized by loss of brush border and cytoplasmic vacuolation. 4. The hemodynamic changes probably played an important role in the pathogenesis of the functional and histopathologic renal changes developed by the animals after venom injection.

Post-discharge surveillance and infection rates in obstetric patients.

OBJECTIVE: To study the impact of post-discharge surveillance on the detection of nosocomial surgical site infection (SSI) after cesarean section and vaginal delivery. METHODS: During a 21-month period, all patients attending the obstetrics service in labor were recruited for a observational study on the incidence of SSI. Examinations to detect SSI were performed daily during the hospitalization period and up to 30 days after hospital discharge in an outpatient clinic supervised by the Infection Control Committee. The stratification of risk-factors and the criteria for the diagnosis of SSI were done in accordance with the methods described by the Centers for Disease Control and Prevention. The rates of surgical site infection detected during the hospitalization period were compared with those reported by the Centers for Disease Control and Prevention's National (United States) Nosocomial Infection Surveillance System (CDCNNIS) 'benchmarks'. The incidence of SSI detected by post-discharge outpatient surveillance was compared with that from in-hospital surveillance, for both cesarean section and vaginal delivery. RESULTS: A total of 4463 deliveries were performed during the study period, 2431 (54.5%) by the vaginal route and 2032 (45.5%) by cesarean section. In-hospital surveillance was done on all patients. Post-discharge examinations were done on 951 (46.8%) of the 2032 cesarean section patients. The incidence of SSI in cesarean section detected by in-hospital surveillance was 1.6% (32 cases) and lower than the 3.6% mean rate reported by the CDCNNIS. When SSIs detected by post-discharge surveillance were included, the total number of SSI was 196 cases (9.6%), a value much higher than that for the SSI detected by in-hospital surveillance alone. Only 5 cases (0.21%) of SSI were detected among the 2431 vaginal deliveries. CONCLUSIONS: The results of our study demonstrate that most of SSI following cesarean section were detected only after patient's discharge from the hospital and seems to indicate that failing to do follow-up evaluation of these patients could result in a substantial mis-calculation of the authentic SSIs rates. Therefore data on post-discharge surveillance should be included to realistically estimate the true rates of SSI in obstetric patients and to allow the implementation of measures to reduce post-partum infection.

[Respiratory involvement secondary to crotalid ophidian bite (Crotalus durissus)]. / Comprometimento respiratório secundário a acidente ofídico crotálico (Crotalus durissus).

Three patients presented respiratory abnormalities following Crotalus durissus snakebite. These abnormalities appeared in the first 48 h after the snake bite and consisted of dyspnea, tachypnea, use of accessory muscles of respiration (cases 1 and 2) and flaring of the nostrils (case 2). Cases 1 and 2 developed acute respiratory failure. Case 2, 24 h after the snakebite presented difficult breathing and periods of apnea. He was intubated in the emergency room and transferred to the intensive case unit where he arrive with spontaneous breathing. His respiratory pattern worsened and measurement of arterial pH and blood gases showed metabolic and respiratory acidosis with partial carbon dioxide pressure increasing from 40 to 50.3 mmHg compatible with acute ventilatory failure. Both patients needed mechanical ventilation. Weaning from the ventilator was accomplished after 33 days in case 1 and after 15 days in case 2. Both patients also presented acute renal failure treated with peritoneal dialysis with full recovery of the renal function. Measurements of forced vital capacity (FVC) and forced expiratory volume in the first second (FEV 1.0) was carried out 58 hours after the snakebite in case 3. Both FVC and FEV 1.0 were reduced in relation to the predicted values (60 and 67% respectively) but the ratio FEV 1.0/FVC was in the normal range. These findings were compatible with a restrictive pattern of ventilatory failure. Serial measurements showed progressive increase of both FVC and FEV 1.0 reaching 72 and 79% of the predicted values, respectively, in the 10th day after the snakebite.(ABSTRACT TRUNCATED AT 250 WORDS)

Standardization of an enzyme linked immunosorbent assay (ELISA) for detecting circulating toxic venom antigens in patients stung by the scorpion Tityus serrulatus.

The sensitivity and specificity of an enzyme-linked immunosorbent assay (ELISA) for the detection of circulating antigens from toxic components of Tityus serrulatus scorpion venom was determined in patients stung by T. serrulatus before antivenom administration. Thirty-seven patients were classified as mild cases and 19 as moderate or severe cases. The control absorbance in the venom assay was provided by serum samples from 100 individuals of same socioeconomic group and geographical area who had never been stung by scorpions or treated with horse antisera. The negative cutoff value (mean + 2 SD) corresponded to a venom concentration of 4.8 ng/ml. Three out of the 100 normal sera were positive, resulting in a specificity of 97%. The sensitivity of the ELISA when all cases of scorpion sting were included was 39.3%. When mild cases were excluded, the sensitivity increased to 94.7%. This study showed that this ELISA can be used for the detection of circulating venom toxic antigens in patients with systemic manifestations following. T. serrulatus sting but cannot be used for clinical studies in mild cases of envenoming since the test does not discriminate mild cases from control patients.

A comparison of survival, pneumonia, and hospitalization in patients with advanced dementia and dysphagia receiving either oral or enteral nutrition.

OBJECTIVES: This study aimed to evaluate the survival rate, pneumonia incidence, and hospital admissions among elderly patients with advanced dementia and to compare these outcomes between patients receiving enteral and oral nutrition. DESIGN: An observational, prospective, non-randomized, and unblinded study, with a minimum follow up of 6 months. SETTING: Inpatient wards as well as ambulatory and emergency units run by a Brazilian university. PARTICIPANTS: Dysphagic elderly patients aged ≥ 60 years with advanced dementia (classified as at least 7A according to the Functional Assessment Staging [FAST]). Both patients with gastrostomies and nasogastric feeding tubes were included in the alternative feeding group. MEASUREMENTS: Following informed consent, a complete clinical examination was performed upon recruitment, and the primary caregiver was interviewed. Data concerning the major outcomes described above, as well as other demographic and clinical information, were recorded at admission and during follow-up phone calls. Survival analysis was performed using a Kaplan-Meier curve and a stepwise Cox regression analysis. RESULTS: Sixty-seven elderly patients were recruited: 36 (53,7%) for oral feeding and 31 for alternative feeding (n = 28 nasogastric tube). Of these, 57 (85.1%) were classified as at least FAST 7C. They were, on average, 84.79 years old, mostly women (85.1%), and with a low level of education (2.9 years). Mortality at 3 months was 11.1% among the oral feeding group and 41.9% among the alternative feeding group (p = 0.004). At 6 months, the mortality rate increased to 27.8% and 58.1%, respectively (p = 0.012). The following variables persisted in the regression model at the end of the analysis: feeding route (p = .018; RR = 2.33; CI: 1.158-4.667), duration of dementia (p = .014; RR = .88; CI: .786-.974) and number of pressure ulcers (p = .007; RR = 1.250; CI: 1.063-1.470). A higher incidence of aspiration pneumonia was observed in the alternative feeding group (p = 0.006), but no difference in the number of hospital admissions was detected between the groups (p = 0.365). CONCLUSION: The use of alternative feeding, along with the number of pressure ulcers were associated with an increased risk of death in elderly patients with advanced dementia. A higher incidence of aspiration pneumonia was also observed in the alternative feeding group. The number of hospital admissions was not different between the feeding routes.