Mature teratoma of the pineal region in the paediatric age group: A case report and review of the literature.

INTRODUCTION: Intracranial teratomas account for 0.5% of all intracranial tumours and 2-4% of intracranial tumours in children. However, in terms of tumours of the pineal area, the exact incidence is not ascertained. Although, it is noted that 50-60% of central nervous system (CNS) germ cell tumours are found in the pineal gland. The degree of difficulty in the sampling of lesions in the pineal gland during biopsy emphasizes the importance of correlating the imaging studies, histopathologic findings, and serum and cerebrospinal fluid (CSF) tumour markers. CASE REPORT: This case report is that of a 9-year-old male who presented with frontal headache of eight days, with associated photophobia, nausea and vomiting, and diplopia. Biopsy with intraoperative navigation was done and the specimen was referred for histopathologic evaluation. The biopsy showed findings consistent with a mature teratoma with no histologic findings of an immature component or secondary somatic malignancy. Comparison of the pre-operative and post-operative multiaxial cranial CT scan showed findings that was consistent with a residual lesion. This was correlated with the pre-operative serum tumour markers which showed alpha-fetoprotein of 22.5 ng/mL and beta-HCG of 1.0 mIU/mL(IU/L), and the post-operative tumour markers of the cerebrospinal fluid that showed alpha-fetoprotein of 3.28 ng/mL and beta-HCG of 18.9 mIU/mL (IU/L). CONCLUSION: A review of the literature and comparison with current case in relation to the histopathologic, serum and CSF findings, and imaging studies was done to better understand the mechanism of this lesion.

La Crosse encephalitis in children.

BACKGROUND: La Crosse encephalitis is a mosquito-borne disease that can be mistaken for herpes simplex encephalitis. It has been reported in 28 states but may be underrecognized. METHODS: We investigated the manifestations and clinical course of La Crosse encephalitis in 127 patients hospitalized from 1987 through 1996. The diagnosis was established by serologic testing for IgM and IgG antibodies to La Crosse virus. Data were collected by chart review. RESULTS: Most of the patients were school-aged children (mean [+/-SD] age, 7.8+/-3.5 years; range, 0.5 to 15.0). Symptoms included headache, fever, and vomiting (each in 70 percent or more of the patients), seizures (in 46 percent), and disorientation (in 42 percent). Thirteen percent had aseptic meningitis. Hyponatremia developed in 21 percent, and there were signs of increased intracranial pressure in 13 percent. Six patients, including three with cerebral herniation, underwent intracranial-pressure monitoring. The 13 patients (11 percent) whose condition deteriorated in the hospital had decreases in serum sodium levels (P=0.007), and increases in body temperature (P=0.003) at the time of deterioration. At admission, these patients more often had a history of vomiting (P=0.047) and a score of 12 or lower on the Glasgow Coma Scale (P=0.02) than the others; a trend toward a greater prevalence of seizures at admission was also evident in this group (P=0.07). All the patients survived, but 15 of them (12 percent) had neurologic deficits at discharge. Follow-up assessments, performed in 28 children, suggested an increase in cognitive and behavioral deficits 10 to 18 months after the episode of encephalitis. CONCLUSIONS: La Crosse virus infection should be considered in children who present with aseptic meningitis or encephalitis. Hyponatremia and increasing body temperature may be related to clinical deterioration.

Pressure-aided microwave rubber vulcanization in a ridged three-zone cylindrical cavity

The characteristics of pressure-assisted microwave vulcanization of rubber were studied in a monomode cavity. For this purpose a modified cylindrical cavity was designed taking into account the external pressure of dielectric molds at the same time that heating was taking place. The monitoring of dielectric properties of rubber sample during the vulcanization process was demonstrated to be of the utmost importance to correlate the evolution of the rubber when is heated with microwaves with the main processing parameters (viscosity and degree of cure). The results obtained looked promising as the vulcanization rates were accelerated giving vulcanized samples comparable in quality to conventional treatment methods.

Enzyme inactivation analysis for industrial blanching applications: comparison of microwave, conventional, and combination heat treatments on mushroom polyphenoloxidase activity.

Browning reactions in fruits and vegetables are a serious problem for the food industry. In mushrooms, the principal enzyme responsible for the browning reaction is polyphenoloxidase (PPO). Microwaves have recently been introduced as an alternative for the industrial blanching of mushrooms. However, the direct application of microwave energy to entire mushrooms is limited by the important temperature gradients generated within the samples during heating, which can produce internal water vaporization and associated damage to the mushrooms texture. A microwave applicator has been developed, whereby irradiation conditions can be regulated and the heating process monitored. Whole edible mushrooms (Agaricus bisporus) were blanched by conventional, microwave, and combined heating methods to optimize the rate of PPO inactivation. A combined microwave and hot-water bath treatment has achieved complete PPO inactivation in a short time. Both the loss of antioxidant content and the increase of browning were minor in the samples treated with this combined method when compared to the control. This reduction in processing time also decreased mushroom weight loss and shrinkage.

Thermal inactivation of mushroom polyphenoloxidase employing 2450 MHz microwave radiation.

Browning reactions in fruits and vegetables are a serious problem for the food industry. In mushrooms, the principal enzyme responsible for the browning reaction is polyphenoloxidase (PPO). A microwave applicator has been designed and used for studying mushroom PPO inactivation. The effects of microwaves and conventional heating on the kinetics of the monophenolase and diphenolase activities of PPO were studied. Conventional and microwave treatments produce different enzyme intermediates with different stability and kinetic properties. We describe how considerable time can be saved during microwave inactivation of the enzyme compared with the time needed when conventional hot-water treatment is used, resulting in greater profitability and enhanced quality. The short exposure time required for samples irradiated with microwaves is very important for maintaining the quality of mushrooms. The fast microwave treatment used resulted in an increase in antioxidant content and a considerable decrease in browning.

Acute encephalopathy and intractable seizures in a 10-year-old boy.

We report a 10-year-old child with Robinow's syndrome who had a 2-week history of headaches and dizziness. On the day of admission, he developed a focal onset seizure with rapid secondary generalization. The seizures were intractable despite adequate doses of benzodiazepine, phenytoin, and phenobarbital, requiring a pentobarbital drip. Continuous electroencephalogram (EEG) monitoring showed persistence of the epileptiform discharges for 13 days. Cerebrospinal fluid and brain biopsy studies were unrevealing. Mycoplasma pneumonia titers showed elevation of both immunoglobulins G and M that doubled during the tenth hospital day. High-dose methylprednisolone was begun, and within 12 hours of initiation the patient sat up and began to follow commands appropriately. The overall EEG background markedly improved. Central nervous system Mycoplasma pneumoniae infection should be suspected in patients with an encephalopathy of unclear etiology.

Enzyme inactivation analyses for industrial blanching applications employing 2450 Mhz monomode microwave cavities.

Browning reactions in fruits and vegetables are recognized as a serious problem for the European food industry, particularly for the mushroom sector. The major enzyme responsible for the browning reaction is polyphenoloxidase (PPO). In this paper considerable reduction has been achieved in both the time and temperature required for complete microwave enzyme inactivation compared to conventional hot-water treatments, which can be translated into both increased benefits and enhanced quality products for the food industry. Furthermore, the short exposure time required for complete inactivation of aqueous solutions of PPO irradiated with microwaves within monomode cavities is very important to reduce the browning rate of mushroom extracts, and could lead to a much greater product profitability when treating whole processed mushrooms.

Human cortex development: estimates of neuronal numbers indicate major loss late during gestation.

This morphometric study explores temporal and topographic changes in the estimated neuronal number in human neocortex during the latter half of gestation and early infancy. Neuronal estimates are calculated from standardized measurements of cortical layer thickness and neuronal density in 6 neocortical regions in 9 human brains ranging from 17 weeks of gestation to 13 weeks postnatally. Layer thickness increases linearly with age while the average neuronal density first increases, then reaches a maximum at 20 weeks of gestation, and progressively declines. The sum of layer thickness times layer density estimates the number of neurons in a cortical column with a fixed surface area and a length that is equal to the cortical thickness. To derive an estimate of potentially overproduced neurons, the number of neurons in each cortical column was corrected for surface growth and for cortex gyration. These data show that a large percent of cortical neurons present at 20 weeks of gestation are used to populate the expanding cortex. Nevertheless, the growth-corrected data suggest that a substantial overproduction and secondary reduction of cortical neurons takes place mainly during the last quarter of gestation. The corrected mean number of neurons reaches a maximum at 28 weeks of gestation and then declines by approximately 70% to achieve a stable number of neurons around birth. This estimated number of neurons is significantly higher at 28 to 32 weeks of gestation than at 17 to 20 gestational weeks and at 0 to 13 postnatal weeks. These data imply that physiologic neuronal death (apoptosis) may play a major role in early human cortex development.

Medical imaging with a microwave tomographic scanner.

A microwave tomographic scanner for biomedical applications is presented. The scanner consists of a 64 element circular array with a useful diameter of 20 cm. Electronically scanning the transmitting and receiving antennas allows multiview measurements with no mechanical movement. Imaging parameters are appropriate for medical use: a spatial resolution of 7 mm and a contrast resolution of 1% for a measurement time of 3 s. Measurements on tissue-simulating phantoms and volunteers, together with numerical simulations, are presented to assess the system for absolute imaging of tissue distribution and for differential imaging of physiological, pathological, and induced changes in tissues.

Prediction of persistence in the use of intra-uterine device from selected demographic factors.

PIP: 85 residents of the Tondo, Philippines who were IUD registrants at the Mary Johnston Hospital Family Planning Clinic were interviewed to determine which combination(s) of certain selected demographic variables have the potential for predicting persistence in IUD use. Data collected concerned length of use of the IUD, age, number of living children, education and income of the respondent at the time of adoption. Regression analysis using REGRESS program evaluation of t-values, F-values, Durbin Watson statistic coefficients of determination was the analysis undertaken. Predictions of persistence can be made from the single factors of age of respondent and the number of living children a woman has. Predictions can also be made from combinations of the following factors: number of living children and age of the respondent; number of living children and monthly family income; number of living children and educational achievement of the respondent; and age and monthly family income of the respondent.^ieng