Increase In Number Of Cases Research Articles

Factors determining the pattern of the variant Creutzfeldt-Jakob disease (vCJD) epidemic in the UK.

Following the emergence of a new variant of Creutzfeldt-Jakob disease (vCJD) 6 years ago, and the gradual rise in clinical cases, there has been increased speculation regarding the overall magnitude of this epidemic in Great Britain. In this paper, we explore the epidemiological factors and uncertainties determining the scale of this epidemic in light of the most recent data on reported vCJD mortality. Our results demonstrate that, while the magnitude of the uncertainty has decreased dramatically since 1996, it is still not possible to predict with any degree of accuracy the final magnitude of this epidemic, with the 95% confidence interval for future cases being from 10 to 7000 deaths. However, short-term projections show that it is unlikely that a dramatic increase in case numbers will be observed in the next 2-5 years (95% confidence interval for 2 years: 10-80 cases, for 5 years: 10-200 cases). The results confirm significant age-dependent susceptibility/exposure to infection, with the likelihood profile demonstrating that those aged between 10 and 20 years are at highest risk of infection. We also demonstrate how projections based on onset data may be substantially biased, and explore the sensitivity of results to assumptions concerning the exposure to bovine spongiform encephalopathy (BSE) and the incubation-period distribution.

Reply: Say Yes and No to MMR; 'Theory of Relativity'!!

Dear Editor, It will clearly take many years of sustained cohort immunization to achieve desired level of artificially induced herd immunity. Meanwhile, prior to this desirable state of affairs, the changes in epidemiological patterns of infection induced by vaccination are not always beneficial. Rubella and mumps are clear examples because of the risk of congenital rubella syndrome (CRS) and the occurrence of orchitis in post-pubertal males. Any level of vaccination coverage will reduce the incidence of infection but by increasing the average age at which those still susceptible acquire infection, certain levels of coverage may increase the incidence of disease. The important question is whether the increase in the proportion of cases in older people will result in an increase in the absolute number of cases of serious disease. The problem has resulted in the adoption of different vaccination programmes against rubella (to control CRS) in different countries [1]. Until the introduction of MMR vaccine in UK in 1988, only girls were vaccinated at an average age of around 12 years, so as to allow rubella virus to circulate in males and young females and create naturally acquired immunity in the early years. By contrast, it has always been the case in the USA for both boys and girls to be vaccinated around 2 years of age, with the aim of blocking rubella transmission. Mathematical models predict that the USA policy is best if very high levels of high vaccination (80-85% of each yearly cohort) can be achieved at a young age, while the earlier UK policy is better if this cannot be guaranteed. A mixed policy is predicted to be of additional benefit over the selective policy alone if moderate to high levels of vaccine uptake among boys and girls can be achieved at a young age (> 60%) [2]. Data from Finland, show the need to continue schoolgirl vaccination until the cohorts with high level immunity through infant vaccination span the entire high fertility age groups [3]. As for mumps vaccination, during infancy, mathematical models show that there is little benefit to be obtained by vaccination at less than 60%, and indeed vaccination at anything less than 70% coverage is potentially hazardous when considering risk of orchitis. Such a phenomenon is a direct result of the combination of increased age at infection and the risk of complications with age [1]. Though major strides have been made in immunization programmes in our country, only 42% children aged between 12 and 23 months have received all recommended vaccinations [4]. The largest increase in immunization coverage has been for polio vaccination but still 37% of children did not receive the recommended 3 doses. In this scenario introduction of MMR during infancy in our country will be amateurish. The problem is not only lack of finances but the sheer numbers to be covered; not only of cost but cost efficiency and cost benefit. Nothing is absolute; everything is relative.

Group A Streptococcus (GAS) Soft-tissue Infections: A Lethal Organism on the Rise

Several reports over the past decade have suggested that there has been an increase in the number of invasive streptococcal infections with young children and the elderly being at the highest risk. We evaluated the incidence of group A Streptococcus (GAS) and compared it with historic data collected at our institution. Prospective data were collected on patients diagnosed with GAS (with and without shock) admitted to a tertiary-care center from July 1995 to July 2000. Each patient was followed by an infectious disease specialist throughout the hospital stay. Definitions of streptococcal toxic shock syndrome (STSS) developed by the Centers for Disease Control and Prevention were used. Thirty-eight patients (mean age of 39+/-12) presenting with GAS soft-tissue infections were admitted to our institution over a 5-year period (7.6 patients per year). Fourteen (37%) were diagnosed with STSS. This represents a greater than fourfold increase in the average number of cases per year of patients diagnosed with GAS and a nearly 4.5 times greater increase in the annual number of patients diagnosed with STSS. The overall mortality of patients diagnosed with GAS was 13 per cent, which increased to 36 per cent in patients diagnosed with STSS. We conclude that there has been a significant increase in the incidence of GAS soft-tissue infections over the past 5 years at our institution. This may represent a new virulent strain, as the majority of these infections did not occur in typical high-risk patients at the extremes of their lives. Further epidemiologic population-based studies are needed to further delineate the severe nature of this problem.

Effect of counterface on the tribology of UHMWPE in the presence of proteins

Artificial joints in orthopedics occupy a principal position owing to the increase in number of cases suffering from arthritis and associated diseases in addition to impairment caused by accidents. In this work, one of the most commonly used joint material, i.e. ultrahigh molecular weight polyethylene (UHMWPE), was tested against the duplex stainless steels instead of the conventional 316 L stainless steel. The UHMWPE was found to exhibit the lowest friction coefficient and wear rates when lubricated with water followed by globulin and glucose. The friction coefficient in the presence of egg albumen was higher along with high wear rates recorded. Post-test evaluation of surface roughness and wear scar/track analysis was performed to identify the wear mechanisms. Worn surfaces were analyzed using a differential scanning calorimeter for changes in crystallinity with sliding. The specimens tested under lubricated conditions with glucose, egg albumen and globulin indicated the presence of reaction products on the worn surface. Adhesive and corrosive wear mechanisms were the predominant modes of wear identified on the polymer samples. The wear tracks indicated that the proteins did react with the counterface material forming a thin deposit on them. Low temperature nitriding of the duplex stainless steel counterfaces were performed and the UHMWPE specimens were tested under similar conditions against the nitrided surfaces. Low temperature nitriding of the counterface did result in improved tribological behavior of UHMWPE and the corrosive effects were minimal.

Balancing interests in autism study

Confusion and controversy loom large whenever autistic spectrum disorders are discussed. A major review commissioned by the British government should sort the facts from the legends, hopes Michael Gross.The raging debate on whether or not the combined measles, mumps and rubella (MMR) vaccine can trigger the onset of autistic spectrum disorders (latest research suggests it doesn't) has demonstrated one thing very clearly: that there is a lot of uncertainty and misinformation about autism, a condition that affects 0.1% of the population. Parents of autistic children know how difficult it is to filter any meaningful information from a stream of dubious reports on miracle cures, horrifying increases in case numbers, newly identified causes, and new theories. Short of a cure, weeding out the information jungle would be a major step to make life easier for everybody involved. Similarly, a future-oriented research policy capable of tackling the disease would need to be based on a clear understanding of what can presently count as established knowledge, and what is mythology.In response to this problem, the British government has recently commissioned the Medical Research Council (MRC) to provide a report on the present scientific knowledge about the epidemiology and causes of autism. The MRC has set up three expert panels and a ‘lay group’ consisting of people involved with autism in non-academic ways.There is first the case definition and epidemiology group. This group will have to address questions such as whether the apparent increase in case numbers over the past decade is an artefact of shifting definitions, or whether there is a real ‘epidemic’. If the increase is real, then there must be biological causes for it, which may be found in the remit of the physiology and infections group which has possibly the trickiest task, including the MMR question along with other possible environmental influences on the condition. While there is a clear genetic component to autism (around a dozen genes are thought to be involved), the disorder is also linked to bowel malfunctions, which led to theories that blame the symptoms on food ingredients such as milk proteins or gluten. Finally, there is a group dealing with psychology and behaviour. As the psychological ‘causes’ of autism postulated in the 1950s have by now been ruled out completely, and educational provision is excluded from the remit of the review, this last part of the review is likely to stir less controversy than the others.Of the six ‘lay group’ members, two are associated with each of the review groups. The panels’ membership sparked some controversy. Andrew Wakefield, the researcher who claimed that the MMR vaccine triggered autism, was said to be concerned about the fact that four members, including two academics and one lay group member serving on the physiology board, had been involved in the court case brought against manufacturers of the MMR vaccine by parents. The view that this constitutes a conflict of interest, however, did not prevail.The report should become publicly available by the end of this year. MRC research boards will consider the results with a view to convert its suggestions into actual research that will put an end to decades of confusion.Michael Gross is a science writer and consultant based at the Oxford Centre for Molecular Sciences. He can be contacted through his web page at http://www.michaelgross.co.uk.

Radial forearm and fibula free flap reconstruction after radical resection of head and neck malignancies

The incidence of head and neck cancer has been rapidly increasing in Hungary during the last decade. Most of these tumors are discovered in advanced stage, consequently, surgical removal of the tumor results in large complex defects in the soft tisses and bone elements of the face and neck. For optimal anatomical and functional reconstruction we perform free flap transfer in increasing number of cases. Between December 1993 and March 2001 in the Head and Neck Surgery Department of the National Institute of Oncology the defects after resection of head and neck tumors were reconstructed with free flaps in 85 cases. Radial forearm flap in 64 cases, fibula osteoseptocutaneous flap in 14 cases were used. In 87% of the patients the postoperative period was uneventful, the surgical complications were not more numerous than following traditional reconstructions. The average duration of operations became shorter by 2.5 hours during the last two years than before. In most of the cases we achieved good functional and esthetic results. The quality of life of the patients was excellent in 14%, almost normal in 73% and bad with serious problems of social life in 13%. It is surprising that there was no significant difference between the survival of neck node positive and negative patients. In our practice the replacement of large defects in the head and neck region with free flaps is a reliable and useful method for reconstruction.

Bootstrapping regression models with BLUS residuals

To bootstrap a regression problem, pairs of response and explanatory variables or residuals can be resam-pled, according to whether we believe that the explanatory variables are random or fixed. In the latter case, different residuals have been proposed in the literature, including the ordinary residuals (Efron 1979), standardized residuals (Bickel & Freedman 1983) and Studentized residuals (Weber 1984). Freedman (1981) has shown that the bootstrap from ordinary residuals is asymptotically valid when the number of cases increases and the number of variables is fixed. Bickel & Freedman (1983) have shown the asymptotic validity for ordinary residuals when the number of variables and the number of cases both increase, provided that the ratio of the two converges to zero at an appropriate rate. In this paper, the authors introduce the use of BLUS (Best Linear Unbiased with Scalar covariance matrix) residuals in bootstrapping regression models. The main advantage of the BLUS residuals, introduced in Theil (1965), is that they are uncorrelated. The main disadvantage is that only n —p residuals can be computed for a regression problem with n cases and p variables. The asymptotic results of Freedman (1981) and Bickel & Freedman (1983) for the ordinary (and standardized) residuals are generalized to the BLUS residuals. A small simulation study shows that even though only n — p residuals are available, in small samples bootstrapping BLUS residuals can be as good as, and sometimes better than, bootstrapping from standardized or Studentized residuals.

FUZZY/PROBABILITY ~ FRACTAL/SMOOTH

Many applications of probability theory are based on the assumption that, as the number of cases increase, the relative frequency of cases with a certain property tends to a number – probability that this property is true. L. Zadeh has shown that in many real-life situations, the frequency oscillates and does not converge at all. It is very difficult to describe such situations by using methods from traditional probability theory. Fuzzy logic is not based on any convergence assumptions and therefore, provides a natural description of such situations. However, a natural next question arises: how can we describe this oscillating behavior? Since we cannot describe it by using a single parameter (such as probability), we need to use a multi-D formalism. In this paper, we describe an optimal formalism for describing such oscillations, and show that it complements traditional probability techniques in the same way as fractals complement smooth curves and surfaces.

Eating disorders.

Anorexia nervosa and bulimia nervosa are primarily psychiatric disorders characterized by severe disturbances of eating behaviour. Anorexia nervosa has been well documented in pre-pubertal children. Eating disorders are most prevalent in the Western cultures where food is in abundance and for females attractiveness is equated with thinness. Eating disorders are rare in countries like India. As Western sociocultural ideals become more widespread one may expect to see an increase in number of cases of eating disorders in non-Western societies. Etiological theories suggest a complex interaction among psychological, sociocultural, and biological factors. Patients with anorexia nervosa manifest weight loss, fear of becoming fat, and disturbances in how they experience their body weight and shape. Patients with bulimia nervosa present with recurrent episodes of binge eating and inappropriate methods of weight control such as self-induced vomiting, and abuse of diuretics and laxatives. Major complications of eating disorders include severe fluid and electrolyte disturbances and cardiac arrhythmias. The most common cause of death in anorexia nervosa is suicide. Management requires a team approach in which different professionals work together. Individual and family psychotherapy are effective in patients with anorexia nervosa and cognitive-behavioral therapy is effective in bulimia nervosa. Pharmacotherapy is not universally effective by itself. Patients with eating disorders suffer a chronic course of illness. The pediatrician plays important role in early diagnosis, management of medical complications, and psychological support to the patient and the family.

Temporal relationship modeling: DTP or DT immunizations and infantile spasms

The time relationship between DTP immunization and infantile spasms (IS) onset was examined using three models—association, temporal shift, and no-effect—and the case/control data from the National Childhood Encephalopathy Study (NCES). Infantile spasms cases classified as being previously abnormal (e.g. tuberous sclerosis complex patients) showed a no-effect relationship, whereas those classified as previously normal suggested a fit to the temporal shift model, i.e. no increase in number of cases but a shortening of time to onset of seizure. No data fit the association model. Analyses for vaccine complications should examine for temporal changes (i.e. temporal shift) in addition to increased risks.

Twelve years experience of acute renal failure in Taiwan

Summary: A retrospective analysis of the records of 287 patients diagnosed with acute renal failure (ARF) who were admitted between 1 January 1983 and 30 November 1994 to the emergency Service Department of the National Taiwan University Hospital, Taiwan was conducted. A total of 176 men (61.3%) and 111 women (38.7%) were surveyed. the classification of ARF by year revealed a progressive increase in case numbers. the majority (57.5%) of the patients were elderly, particularly in the years 1987‐88 and 1993‐94, the differences (aged compared with the young) being statistically significant. There were 176 patients (61.3%) in the pre‐renal group (with evident intravascular volume depletion, haemodynamic instability or sepsis, with a urine excretion of sodium (FENa<1%), 43 (15%) in the renal group (urine analysis revealing protenuria, granular casts or/and tubular epithelial casts and without response to treatment of volume repletion), and 27 (9.4%) in the postrenal group (diagnosed when there were supporting image studies). Overall mortality was 63% and the pre‐renal ARF patients had the poorest survival rate (25.6%). the classification of mortality rates by diagnostic category and year revealed a persistently high mortality rate. We conclude that: there are increasing patients with ARF each year; aged patients comprise the majority of cases; and the mortality rate remains high because of the high mortality rate of the pre‐renal group, which was due to the presence of complicating underlying diseases and concomitant organ failure. the effects of having an ageing population were also apparent.

Descriptive profile of tuberculin skin testing programs and laboratory-acquired tuberculosis infections in public health laboratories.

The increase in numbers of cases of tuberculosis in the United States has placed greater demands on mycobacteriology laboratory workers to produce rapid and accurate results. The greater number of specimens generated by the increased emphasis on detecting the disease has placed these workers at greater risk of laboratory-acquired infection. We surveyed 56 state and territorial public health laboratories to determine the status of existing tuberculin skin testing (TST) programs and to evaluate the frequency of probable laboratory-acquired tuberculosis for each responding mycobacteriology laboratory. Probable laboratory-acquired infections were determined by each laboratory's evaluation of occupational positions, duties, and employee histories and review of medical records. Two-step TST for new employees was routinely practiced in only 33% of responding laboratories, and mycobacteriology laboratorians were found to be most frequently screened when they were compared to employees of other departments. Of 49 (88%) responding laboratories, 13 reported that 21 employees were TST converters from 1990 to 1994. Seven of these 21 employees were documented to have laboratory-acquired infections based on evaluations by their respective laboratories. Based on Centers for Disease Control and Prevention guidelines, converters are categorized on the basis of both a change in the size of the zone of induration and the age of the person being tested. By the definitions in the guidelines, 14 mycobacteriologists were identified as recent converters, 7 of whom were > or = 35 years of age and 4 of whom were exposed in the laboratory within a 2-year period. Inadequate isolation procedures, the high volume of specimen handling, and faulty ventilation accounted for these laboratory-associated infections. These results suggest that more frequent periodic evaluations based on documented TST conversions for workers in mycobacterial laboratories should be performed, since this population is at increased risk of becoming infected with Mycobacterium tuberculosis. Although general assessments are necessary to accurately and effectively evaluate the risk of tuberculosis transmission, they are especially important for those working in high-risk areas within a public health laboratory.

Stages in the recognition of epidemic pellagra in the United States: 1865-1960.

Recognition of the U.S. pellagra "epidemic" in the early part of this century occurred in stages. The recognition process distorted impressions of magnitude, rate of spread, and virulence. Unrecognized cases: Endemic pellagra developed from dietary deficiencies after the Civil War. Initially, cases were misdiagnosed as other more traditional disorders. Tradition and authority inhibited recognition. Recognition of severe cases: Beginning in 1907, outbreaks were reported in asylums. Existing severe cases came rapidly to medical attention, inflating the apparent rate of spread. Recognized cases had a fulminant course and a high case fatality. Expanded spectrum: Milder cases were increasingly recognized, leading to an exaggerated rate of increase in number of cases and a decrease in case fatality and apparent virulence. Greater sensitivity resulted largely from a shift in diagnostic thresholds, with loss of specificity and increase in false positive diagnoses. Standardization of diagnosis: Although no suitable diagnostic marker test was developed, diagnosis was ultimately standardized by development of a workable case definition and by assessment of response to an effective therapy (nicotinic acid) applied to presumptive cases.

Incidence of and Treatment for Ductal Carcinoma In Situ of the Breast

To describe trends in incidence and treatment for ductal carcinoma in situ (DCIS) of the breast in the United States between 1973 and 1992 and to estimate total numbers of in situ cases diagnosed and numbers treated by mastectomy since 1983, when screening mammography for breast cancer began to become widespread. Analysis of population-based breast cancer incidence data collected by the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program since 1973 and treatment data collected by the SEER program since 1983. All women in the geographic areas af the United States included in the SEER program. Annual age-adjusted and age-specific incidence rates for DCIS; time trends in distribution of cases by type of treatment; percentage of cases treated by mastectomy by geographic area; and estimated numbers for the entire United States of DCIS cases, mastectomies for DCIS, and cases attributable to mammography. There was a marked increase in DCIS incidence beginning in the early 1980s. Average annual increases in rates between 1973 and 1983 and between 1983 and 1992 changed from 0.3% to 12.0% among women aged 30 to 39 years, from 0.4% to 17.4% among women aged 40 to 49, and from 5.2% to 18.1% among women aged 50 years or older. The total estimated number of DCIS cases in the United States in 1992 (23,368) was 200% higher than expected based on 1983 rates and trends between 1973 and 1983. Between 1983 and 1992, there was a marked decline in the proportion of DCIS cases treated by mastectomy (from 71% to 43.8%) and an increase in those treated by lumpectomy (from 25.6% to 53.3%). In 1992, 23.3% of cases were treated by lumpectomy and radiation, 30.2% by lumpectomy alone, and 2.6% with no surgery. Treatment patterns varied substantially by geographic area, with 57.7% of cases in New Mexico treated by mastectomy in 1992 compared with 28.8% in Connecticut. Despite the decline in the proportion of cases treated by mastectomy, the increased DCIS incidence rates resulted in an increase in the absolute number of cases treated by mastectomy until 1990 (n=10,657); in 1992, there were an estimated 10,242 DCIS cases treated by mastectomy. Incidence rates of DCIS of the breast have increased dramatically since 1983. This increase correlates with the widespread adoption of modern mammographic screening. While early detection of invasive breast cancer is beneficial, the value of DCIS detection is currently unknown. There is cause for concern about the large number of DCIS cases that are being diagnosed as a consequence of screening mammography, most of which are treated by some form of surgery. In addition, the proportion of cases treated by mastectomy may be inappropriately high, particularly in some areas of the United States.

Mortality from group C meningococcal disease: a case for a conjugate vaccine?

This 17-year retrospective review of children with meningococcal disease (MCD) has determined the mortality due to serogroup C, in order to assess the potential impact of a group C conjugate vaccine. Four hundred and forty-nine cases of MCD were admitted to our hospitals during 1977-1993; 78 due to group C, 11 of whom died. There was a significant increase in the proportion of cases due to group C from 1986 onwards (10% vs 21%), and an increase in the total number of cases of MCD (151 vs 298). The currently available group C polysaccharide vaccine has low efficacy below 2 years of age and could not have prevented 54 cases of group C disease. A conjugate group C vaccine administered between 2 and 4 months of age could have prevented 68 cases, including all fatal cases. The recent increase in MCD is partly due to an increase in group C disease. A meningococcal group C conjugate vaccine could prevent most cases of infection due to group C, and decrease the mortality from MCD by up to 30%.

Extracorporeal Life Support Organization 1994

The annual report of the Extracorporeal Life Support Organization is presented for 1994. The aggregate experience of neonatal, pediatric pulmonary, and neonatal/pediatric cardiac patients treated with extracorporeal membrane oxygenation is presented for data collected to April 1994. In addition, the Registry now includes a large number of adult extracorporeal membrane oxygenation cases. Rates of survival for each patient group remained unchanged from previous years with 81% neonatal, 50% pediatric, and 44% cardiac survival. Complete data are available through 1992, with increasing case numbers each year as a basis for this growing registry.

Pediatrik Davranış Nörolojisi

SummaryAs an underlying brain dysfunction has been shown in an increasing number of cases of mental retardation autism and language disturbance pediatric neurology has been a field of growing attraction nbsp; Due to the enormous development in the new imaging techniques and laboratory analyses it has been possible to show an organic lesion in many of those cases In such a field where our country is not so backward in comparison to the developed countries the integration of various studies and cooperation of people from different disciplines are necessary for a better management of mentally handicapped people So many of those people expect the consequences of such a fruitful attemp Key words: Mental Retardation Behavioral Neurology Brain Dysfunction

Rising trends of oral cancer mortality among males worldwide: the return of an old public health problem.

Oral cancer is considered widely to be a form of cancer whose etiology is well understood and which is becoming relatively rare in developed countries. There have been, however, a series of recent reports indicating that after many years of declining risk, the rates may be rising again in men. To investigate the extent of such changes, national time-series of oral-cancer mortality data available in the World Health Organization's mortality database have been analyzed. Age-period-cohort modeling was used to establish the extent and nature of these changes and to allow comparisons among countries. Nineteen out of 24 national datasets demonstrate a similar pattern of recent increasing cohort-effects for oral cancer in men. The largest increases have occurred in countries of central and eastern Europe where rates have increased by a factor of from three to 10 within a generation. The cohort-based nature of the changes observed in men suggest that there will be a continuing increase in the absolute numbers of cases of oral cancer to be treated in the coming decades.

Tuberculosis in children

The dramatic resurgence and increase in the total number of cases of tuberculous infection and disease in children is alarming in the United States. With poverty, poor access to health care, overcrowding (predominantly in inner-city areas), and an increase in immigration from areas with high endemic rates of TB, the problem in children will continue to increase. If the impact of coinfection with HIV and M. tuberculosis becomes significant in children, as it has in adults in the United States, the increase in the total number of cases of tuberculous disease in children could be staggering. The impact of multidrug-resistant strains of M. tuberculosis and the current crises in availability of effective anti-TB drugs will need a similar resurgence.

Oral cancer in Scotland: changing incidence and mortality.

To determine the incidence of oral cancer in Scotland between 1960 and 1989 and oral cancer mortality from 1911 to 1989. Data were obtained on oral cancer incidence from the information and statistics division of the Common Services Agency of the Scottish Health Service and mortality data from the office of the registrar general for Scotland. Mortality from intraoral cancers in Scotland substantially declined throughout this century until the mid-1970s. This trend, however, was then reversed, and fourfold increases in incidence were observed in younger age groups after 1960. Death rates in these younger age groups increased to levels previously recorded in the 1940s. These increases seemed to be cohort based and may therefore continue into the future. Reasons for increasing rates among younger age groups are speculative and rely on combining knowledge about risk factors and available ecological data. Though increases in incidence at younger ages do not result in a large change in the number of cases diagnosed, possible similar increases continuing into older ages, when oral cancer is more common, will correspond to a much larger increase in the actual number of cases. Given that such a large attributable risk is associated with tobacco and alcohol, however, these increases may be preventable.