Memory, simple and complex language, and the temporal lobe.

Nineteen patients with intractable temporal lobe epilepsy who underwent anterior temporal lobectomy were given a highly specific memory battery (23 tests) pre- and post- (1 week; 1, 2, and 6 months; 1 and 2 years) resection. Sixteen of 23 tests revealed that memory performance of temporal lobe epilepsy patients was worse than normal controls prior to surgery (p < .001), while the most profound differences were seen in the remembering and generation of inferences from connected discourse. Almost no differences were observed in delayed nonmatching to sample tasks (recognition without language task). MRI results revealed that anterior, middle, and posterior hippocampal abnormality was extensive in 12 of 19 patients, and 12 also showed medial temporal lobe abnormalities and volume loss. Hippocampal damage was negatively correlated with extended delay memory performance for connected discourse: worse performance was associated with greater damage. Few differences in less complex memory performance were observed pre-postsurgery. While ordinary recognition functions were preserved, results demonstrated that dominant medial temporal lobe structures appeared heavily involved in language-generated memory, and hippocampus is heavily implicated in both simple and complex language.

Feeding interactions in infants with very low birth weight and bronchopulmonary dysplasia.

Infants with very low birth weight (VLBW) are at increased risk for feeding disorders that can affect growth and development. One hundred and forty one mother-infant pairs were compared [55 with infants with high medical risk due to infant VLBW and bronchopulmonary dysplasia (BPD), 34 VLBW without BPD, and 52 term infants] on operationally defined measures of feeding behaviors and maternal self-report of depression and anxiety. Mothers of VLBW infants with and without BPD spent more time prompting their infants to feed when their infants engaged in nonfeeding behavior. Despite increased maternal efforts, infants with BPD took in less formula, spent less time sucking, and spent a greater proportion of time nonfeeding. VLBW infants without BPD were equivalent to term infants in percentage of time sucking and in volume of formula ingested and were more likely to take in higher calories than infants with BPD. Mothers of VLBW infants with and without BPD were also more likely to report clinically significant symptoms of depression and anxiety than mothers of term infants. Because mothers of VLBW infants who were more depressed or anxious were less likely to verbally prompt their infants to eat, maternal psychological symptoms should be considered in assessing interactions of VLBW mother-infant dyads.

Optical properties of mammalian tissue: introduction by the feature editors.

This issue of Applied Optics features twenty-two papers on the optical character of tissue, a topic of growing importance in the life sciences. The papers deal with theory and experiment and are contributed by a core of researchers active in the current development of this relatively new field. The complete description of the tissue's optical properties is fraught with problems due to the extraordinary nature of this difficult, varied, turbid, highly scattering medium. The solution of these optical problems promises important dividends in practical areas, such as cancer treatment and diagnosis.

Refractive index of some mammalian tissues using a fiber optic cladding method.

The index of refraction n of the many mammalian tissues is an important but somewhat neglected optical constant. Archival and oral papers have quoted the use of values of n for tissue generally ranging from 1.35 to 1.55. However, these values are frequently without experimental basis. They have arbitrarily used values near that of water, which is a major component of mammalian tissue, or have calculated a theoretical n from the weighted elemental composition of tissue. Since these values have not been precise and little information is available on specific indices for each tissue, a study was undertaken to develop a simple, rapid, and reliable method for the experimental determination of n. This was done using the ubiquitous quartz optical fiber. By substituting the usual cladding found on commercial quartz optics by the tissue in question and utilizing the principle of internal reflection, the value of n for the specific tissue can be calculated. This is done by utilizing the known indices for air and quartz and measuring the angle of the emergent cone of light from the output of the optical fiber. A number of indices for mammalian tissue (bovine, porcine, canine, and human) have been determined at 632.8 nm. With few exceptions, for tissues at this wavelength, n was in the 1.38-1.41 range. The species type did not appear to be a factor. Bovine muscle showed normal dispersion characteristics through the visible wavelengths. The denaturation of tissue was shown to alter significantly the refractive index.

Allergic reactions to systemic glucocorticoids: a review.

Over 30 cases of systemic reactivity to adrenocorticosteroids have been reported. With one exception, skin- and challenge-testing have indicated that the glucocorticoid, rather than its vehicle, has been the cause of the reaction. Aspirin-sensitive asthmatic patients may be particularly predisposed to reactions.

Long-term alternate day steroid therapy in renal transplantation. A controlled study.

Seventy-six adult renal allograft recipients were allocated 5 months post-transplantation to daily or alternate day maintenance methylprednisolone therapy. All 15 recipients of living related kidneys and 23 recipients of cadaver kidneys were placed on the alternate day regimen, while 38 patients with cadaveric grafts remained on daily methylprednisolone. In patients on alternate day methylprednisolone, serum creatinine concentrations, frequency of acute rejection episodes, and prevalence of chronic rejection were similar to those of patients on daily steroids. Furthermore, no differences were noted in the rate of loss of graft function between recipients of cadaver kidneys on daily versus alternate day steroids. There were no differences in body weight, blood pressure, degree of hyperglycemia, or hyperlipidemia between patients on the daily or alternate day schedules. However, the prevalence of clinical osteonecrosis and the rate of infectious complications requiring hospitalization were significantly decreased in patients on alternate day methylprednisolone. We conclude that alternate day methylprednisolone therapy is as effective as daily steroids for the maintenance of graft function in renal transplant recipients. The decreased incidence of osteonecrosis and the lower frequency of infectious complications represent a strong argument in favor of alternate day steroid therapy.

Iterative method for elimination of the Kbeta filter in dual-beam differential tissue absorptiometry.

The application of a dual photon beam to the measurement of tissue and tissue-like substances has generally required the use of a filter to attain the required monochromaticity of the lower-energy x-ray photons. In many cases this has the undesirable effect of also severely attenuating the desired low-energy beam. A method for circumventing the use of the filter is described. The technique relies on a knowledge of the initial intensities of the components of the x-ray portion of the dual beam and involves an iterative mathematical procedure. Experimental verification of the method using both tissue and nontissue substances has been carried out. R values obtained with the iterative system show good correlation with filtered values.