Modelling pertussis transmission to evaluate the effectiveness of an adolescent booster in Argentina.

Due to the current epidemiological situation of pertussis, several countries have implemented vaccination strategies that include a booster dose for adolescents. Since there is still no evidence showing that the adolescent booster has a positive effect on the most vulnerable group represented by infants, it is difficult to universalize the recommendation to include such reinforcement. In this work we present an age-structured compartmental deterministic model that considers the outstanding epidemiological features of the disease in order to assess the impact of the booster dose at age 11 years (Tdap booster) to infants. To this end, we performed different parameterizations of the model that represent distinct possible epidemiological scenarios. The results obtained show that the inclusion of a single Tdap dose at age 11 years significantly reduces the incidence of the disease within this age group, but has a very low impact on the risk group (0-1 year). An effort to improve the coverage of the first dose would have a much greater impact on infants. These results hold in the 18 scenarios considered, which demonstrates the robustness of these conclusions.

Random walk with an exponentially varying step

A random walk with exponentially varying step, modeling damped or amplified diffusion, is studied. Each step is equal to the previous one multiplied by a step factor s (01/s relating different processes. For s<1/2 and s>2, the process is retrodictive (i.e., every final position can be reached by a unique path) and the set of all possible final points after infinite steps is fractal. For step factors in the interval [1/2,2], some cases result in smooth density distributions, other cases present overlapping self-similarity and there are values of the step factor for which the distribution is singular without a density function.

Health care insolvency and bankruptcy.

Bankruptcy is an event that is often considered a business' worst nightmare. Debt, lawyers, and the U.S. government can lead to the eventual destruction of a business. This article shows how declaring bankruptcy can be a helpful instrument in continuing a successful venture in the health care marketplace.

Managed care and labor issues: Part II--Bargaining unit clarification.

The intent to expand, shrink, reorganize, or redistribute will have vastly different effects on the workforce. This article discusses employment law issues in general as they apply to MCOs that have both unionized and nonunionized employees.

Managed care and labor issues: Part I--Termination issues.

The intent to expand, shrink, reorganize, or redistribute will have vastly different effects on an organization's workforce. In this article, the author discusses employment law issues in general as they apply to managed care organizations that have both unionized and nonunionized employees.

Metabolizable energy of diets low or high in dietary fiber from cereals when eaten by humans.

The metabolizable energy (ME) of two diets that differed in their content of dietary fiber (DF) from cereal products was measured in balance experiments in six human subjects. DF intake was 19.7 g/d with the low fiber diet and 48.3 g/d with the high fiber diet. Daily gross energy intakes were 2114 kcal (8845 kJ) and 2341 kcal (9795 kJ)/d with the low and the high fiber diets, respectively. DF contributed 83 kcal (347 kJ) and 203 kcal (849 kJ) to daily gross energy intake with the low and the high fiber diets, respectively, when heat of combustion of DF of 4.2 kcal (17.6 kJ)/g was assumed. Increasing the intake of DF resulted in an increase in stool weight and a greater fecal energy loss. Total energy losses were 253 kcal (1056 kJ) and 409 kcal (1711 kJ)/d with the low and the high fiber diets, respectively. ME provided by the low and the high fiber diet were 1861 kcal (7786 kJ) and 1932 kcal (8083 kJ)/d. The total increase in energy losses due to the increase in DF consumption exceeded the gross energy provided by additional DF. Compared with the low fiber diet, ME provided by protein and fat was decreased during the high fiber diet. Calculation of the apparent digestibility of DF indicated that fiber may have provided ME in the form of short-chain fatty acids during the low as well as during the high fiber intake. However, estimation of the amount of fecal gross energy indicated that available components of the diet, such as starch, must have been utilized incompletely during both experimental periods.

Neuropsychological recovery following acute cerebellar ataxia.

Acute Cerebellar Ataxia (ACA) is not infrequent disorder in childhood characterized by sudden onset of such cerebellar signs as truncal ataxia, dysmetria, tremors, nystagmus, and hypotonicity. Despite the suggestion in the literature that children who have suffered from ACA may continue to have neurological deficits, there have not been any attempts to address systematically and quantitatively the nature and frequency of dysfunction in the cognitive and motor domains. To this end, 15 patients with a discharge diagnosis of ACA at Children's Hospital of Michigan were administered a Wechsler Intelligence Scale, visual-spatial tests, achievement tests, and a test of motor speed, targeting, and finger dexterity (the Purdue Pegboard). Results indicated that higher level cognitive functions, including those in the linguistic and visual-perceptual domain, remained intact. In addition, the distribution of academic achievement scores was not markedly atypical. However, Purdue Pegboard performances in the majority of patients were notably impaired. Correlations among cognitive variables and such variables as age at onset and length of hospitalization were nonsignificant: no adequate prognostic indicators were ascertained. The implications of the results for theories of cerebellar plasticity or lack thereof are commented upon.

Comparison of cognitive deficits among autistic and retarded children on the Arthur Adaptation of the Leiter International Performance Scales.

Seven autistic, 7 mentally retarded, and 11 normal children were matched for mental age according to the Arthur Adaptation of the Leiter International Performance Scale (AALIPS). On the basis of two constructs, concrete discrimination and formal discrimination, all of the tasks in the AALIPS were grouped into two indices and six scales. Group comparisons were made on the indices and the scales. The results showed that (a) the performance of the autistic children was better than that of the other two groups on concrete discrimination tasks, (b) the performance of the autistic children was poorer than that of the other two groups on formal discrimination tasks, and (c) the quality of the autistic children's performance decreased as task requirements for formal discrimination increased. This pattern was not observed among the mentally retarded or normal children. A further analysis for sex showed significant main effects for sex on the formal discrimination tasks. The application of these results to test interpretation and future research is discussed.

Strategic planning system for control of venereal disease: record keeping in a clinic for treatment of sexually transmitted diseases.

A manual data processing system and a computer-based system that was integrated into the operations of a clinic for treatment of sexually transmitted diseases were developed. The automated system can generate routine management reports and cross-tabulate data for special studies. It is flexible and adaptable to other localities but is not a panacea for clinical problems.

A rational basis for the epidemiologic treatment of gonorrhea in a clinic for sexually transmitted diseases.

Epidemiologic treatment of gonorrhea refers to the administration of antibiotics when the diagnosis is considered likely, but before the results of confirmatory tests are available. Unfortunately, the risk of infection is seldom known. To place epidemiologic treatment on a more rational basis, infection rates were determined for groups of clinic patients defined by easily collected indexes of risk such as reason for attending the clinic, sex, race, and sexual preference, history of contact with gonorrhea, and history of a urethral or vaginal dischange. Infection rates ranged from 0.8% for men seeking marriage licenses to 65.1% for female contacts of men with "established" gonorrhea. By selectively employing gram-stained smears, it is possible to reduce further the need for epidemiologic treatment within the various defined groups of patients. Epidemiologic treatment policies should be determined by each large clinic and should be based on known infection rates for clearly defined groups of patients. Such rates are necessary for obtaining informed consent from patients and for evaluation of the cost-effectiveness of epidemiologic treatment in the overall effort to control gonorrhea.