Lectin-binding sites in quick-frozen, freeze-substituted extracellular matrix of rabbit corneal stroma: a comparative electron microscopic study with different embedding procedures

The efficiency of Epon, Lowicryl K4M and LR White resins for electron microscopy was tested on the reactivity of carbohydrate residues to lectins in quick-frozen, freeze-substituted extracellular matrix of rabbit corneal stroma, without the use of any chemical fixation. Three lectins conjugated to gold particles were used in a post-embedding method: Wheat germ agglutinin, Concanavalin A and Ricinus communis agglutinin 1. Best gold-labelling was obtained with Lowicryl K4M for Wheat germ agglutinin, and with both Lowicryl K4M and Epon for Concanavalin A and Ricinus communis agglutinin 1. Tissues embedded in LR White gave less intense labelling for the three lectins used in comparison with the two other resins. This study demonstrates the crucial role of resins in the optimal preservation of biological activity of carbohydrate residues in cryotechnically-processed cornea for electron microscopy.

Knowledge acquisition and knowledge representation in a rule-based expert system

It is important to understand and describe how nurses make diagnostic decisions. This article describes the process by which knowledge is acquired and represented in a rule-based expert system for nursing diagnosis. Knowledge acquisition was obtained by tapping the expertise of clinical nurse specialists who were able to articulate the elements present in their diagnostic decisions. Knowledge representation was achieved using a commercially-available software package. VP Expert (Berkeley, CA). The clinical nurse specialists contributed many of the heuristics in the determination of self-care deficit as a nursing diagnosis. Three models of rules for the determination of self-care deficit, bathing are provided. These models represent a method for discriminating between levels of patient dependence. A description of rules that define specific causes, such as immobility are also included. They will be tested in the clinical setting.

New method of ultrastructural localization of WGA-binding sites in the rabbit cornea using quick-frozen specimens followed by freeze-substitution

Wheat germ agglutinin (WGA) conjugated with apo-horseradish peroxidase-gold was used as a probe for ultrastructural localization of N-acetyl-glucosamine and N-acetyl-neuraminic acid residues of glycoconjugates in posterior stroma and Descemet's membrane of rabbit corneas. Ultra-thin sections of quick-frozen, freeze-substituted, and Epon or Lowicryl K4M-embedded tissue were used. Numerous WGA-binding sites were detected in the stromal matrix and Descemet's membrane in both embedding procedures. Labelling was more intense with low-temperature embedding in Lowicryl K4M than with Epon. Gold particles preferentially labelled the major collagen fibrils of the stroma but otherwise appeared uniformly distributed over both extracellular matrices, except in some areas of the stromal matrix that were barely labelled. Frequently, the inter-particle distance of gold particles on collagen fibrils corresponded to the banding period of type I collagen fibrils, suggesting that they point out keratan sulphate proteoglycans which contain WGA-binding sites. The combination of cryotechniques and post-embedding procedures may be very effective for lectin histochemistry of the cornea and other eye tissues.

Changes in cellular membrane and paracellular conductances by amphotericin B in the epithelium of the bullfrog cornea

In the isolated bullfrog cornea, measurements of DC electrical parameters in conjunction with AC impedance and ultrastructural analyses were used to determine the effects of 10(-5) M amphotericin B on epithelial cellular membrane and paracellular conductances. In NaCl Ringers, amphotericin B elicited a 3.5-fold increase in the specific apical membrane conductance (Ga/Ca); where Ga and Ca are the apical membrane conductance and capacitance, respectively. The basolateral membrane conductance (Gb) and the basolateral membrane capacitance (Cb) fell by 57% and 50%, respectively. In the paracellular pathway, the tight junctional complex (Gj) was unchanged whereas the lateral intercellular space resistance (Rp) decreased by 55%. The declines in Gb and Cb were suggestive of cell volume shrinkage because these changes were consistent with a previously described decline in intracellular K+ content and reduction in exposed basolateral membrane area to current flow. Ultrastructural analysis validated that amphotericin B caused cell volume shrinkage because there was: (1) increased folding of the basolateral membrane and waviness of the basal aspects- of the plasma membrane; (2) dilatation of the lateral intercellular spaces. This agreement suggests that intracellular activity decreased following exposure to amphotericin B which resulted in cell volume shrinkage and an impairment of Cl- uptake across the basolateral membrane.

Traumatic atlanto-occipital dislocation in children: review and report of five cases

Traumatic atlanto-occipital dislocation has usually been considered incompatible with life. However, reports on survivors stress the need for early clinical diagnosis of this condition, particularly in the context of multiple trauma, in order to avoid life-threatening diagnostic manipulations and to provide adequate treatment. Five instances of atlanto-occipital dislocation in children observed during the last two years prompted this report, since four of them survived only temporarily. The radiologic and computed tomographic (CT) findings have been reevaluated. Use of metrizamide CT is advised in clinically suspected cases with inconclusive radiologic workup.

Congenital hereditary hypothyroidism--prenatal diagnosis and treatment

Intrauterine diagnosis of congenital hypothyroidism was established on the basis of TSH concentration in amniotic fluid in the 22nd week of gestation for the offspring of a couple both known to have an iodide organification defect. Prenatal treatment consisted of intramniotic injections of 500 mcg Na-1-thyroxine, which was administered from the first amniocentesis until one week before delivery. Following delivery, the diagnosis was confirmed by the elevated level of TSH, 60.5 uU/ml, and a gradual decrease of fT4 to 0.8 ng/ml. Regular substitution therapy was commenced on the third day of life. The normal shape and location of the thyroid gland was demonstrated by Technetium scintiscan. At 18 months the infant revealed no significant deviation from normalcy in growth or mental capacity. This experience indicates that testing of amniotic fluid for TSH in the 22nd week of gestation can be diagnostic for congenital primary hypothyroidism. Furthermore, it is suggested that the treatment approach described is warranted in all cases in which there is a high risk of congenital primary hypothyroidism.

Ectopic pituitary adenoma of the sphenoid sinus: report of a case and review of the literature

Ectopic pituitary adenoma of the sphenoid sinus in a 68-year-old woman is presented. The confusing discrepancy between the imaging features and the mild clinical manifestations of extensive bone destruction of the skull base is emphasized. A definite diagnosis can be established only by histopathological examination supported by immunohistochemical studies.

Self-care deficit with etiologies: reliability of measurement

The purpose of the present study is to examine the reliability of items in an assessment guide for a specific diagnostic label, self-care deficit, and its etiologies/contributing factors. Subjects assessed were 30 patients from an acute orthopedic unit in a large medical center. First, an estimate of internal consistency as a measure of reliability was obtained for items measuring self-care deficit (Cronbach's alpha, 0.83). Second, inter-rater reliability was obtained for the formulation of complete diagnostic statements; that is, self-care deficit with etiologies. An 88% agreement was found with respect to the diagnosis self-care deficit, bathing related to immobility. Overall, agreement on the five most commonly found nursing diagnoses with their etiologies was 69%. The use of an assessment instrument that has reliability and validity may contribute to more accurate diagnostic decisions and impact on appropriate and effective nursing interventions. Further work on assessment parameters for both the diagnostic labels and their etiologies/contributing factors, and the linking of diagnoses to interventions is recommended.

Pulmonary plasma-cell granuloma

A large pulmonary plasma-cell granuloma (PCG) mimicking a mediastinal germinal-cell tumor in a 9-year-old boy is presented. The nonspecificity of the tumoral calcifications and of the radiographic and CT findings in pulmonary PCG is demonstrated.

Filipin-induced deformations in plasma membranes of cultured bovine corneal endothelial cells with incomplete belts of tight junctions

Complete belts of intact tight junctions are thought to act as barriers to the movement of cholesterol in the plane of the plasma membrane. As cholesterol can be revealed by filipin-induced membrane deformations on freeze-fracture images, we studied the distribution of these deformation in cultured bovine corneal endothelial cells with incomplete belts of tight junctions. While the extent of filipin-induced deformations differed between individual cells, there is a homogeneous distribution of filipin-induced deformations on both sides of the incomplete junctional belt of endothelial cells. Our results suggest that cultured endothelial cells do not polarize cholesterol, possibly because of the incomplete tight-junctional barrier.

A computer program to support patient assessment and clinical decision-making in nursing education

This article reports on the development of a computer program for the recording of patient assessments performed by graduate nursing students. This program is part of a larger effort called Computer-Aided Research in Nursing (CARIN) that will also be used for data collection and retrieval. This article describes two phases of the current project. Other nursing diagnosis programs in existence are briefly reviewed, and formulation of the two initial steps of the nursing process, assessment and nursing diagnosis, are described.

[Psychogenic pain as a representation of the maternal object]

Since Freud, psychoanalysis has approached psychogenic pain from two points of view: conversion, and narcissistic hurt through loss of an object (pain of separation). In an early developmental phase concerning the first differentiation of self, body-self and external objects, representatives of physical and psychical pain as well as representatives of frustrating experiences with external objects (emotional deprivation, overstimulation) are able to take the place of each other reciprocally. This means, as Deutsch (1959) has elaborated, the extension of the concept of conversion to pregenital stages and its connection with object-relation-theories. The author suggests an idea of a two phase conversion, by which the primarily acquired defence of conversion is followed by later traumatization, which introduces subsequent conflicts of later developmental stages, for example oedipal ones. In the case of psychogenic pain, where physical and sexual abuse as well as the inherent guilt dynamics are frequently found, they can be integrated by using this hypothetical model. The relation to the conceptualizations of archaic hysterization (McDougall) and secondary hysterization (Mentzos) respectively symbolization (Engel) is discussed; case studies are illustrating the theoretical conception.

Dehydroepiandrosterone-sulfate/cortisol ratio in panic disorder

We hypothesized that the dehydroepiandrosterone-sulfate (DHEA-S)/cortisol ratio, which has been used as an index of adrenocortical function, would be altered in panic disorder patients and would change after treatment. We evaluated 10 male and 14 female outpatients meeting DSM-III-R criteria for panic disorder. Of these 24 subjects, 13 were treated with clonazepam, 8 were treated with alprazolam, and 3 were treated with placebo as part of a double-blind study. The DHEA-S/cortisol ratio values in the 24 patients with panic disorder (mean = 20.5, SD = 11.6) were significantly higher than those of a group of 60 normal controls (mean = 11.5, SD = 6.01) and were also significantly higher than those of a group of 22 depressed patients (mean = 10.6, SD = 6.33). Although there was no significant difference in the pretreatment DHEA-S/cortisol ratio values between male (mean = 23.6, SD = 11.8) and female (mean = 18.2, SD = 11.3) panic disorder patients, the effects of treatment on this ratio differed between the two sexes. In fact, in the female patients there was a significant decrease in the DHEA-S/cortisol ratio at the end of the study (mean = 15.1, SD = 7.9), while in the male patients there was no significant change in this ratio at the end of the study (mean = 30.2, SD = 21.4). No significant differences were noted between pretreatment and posttreatment DHEA-S/cortisol ratio values in patients treated with alprazolam (n = 8), in patients treated with clonazepam (n = 13), or in patients treated with placebo (n = 3).(ABSTRACT TRUNCATED AT 250 WORDS)

[The body and food as objects in anorexia and bulimia]

In this paper the function of food and of the own body in anorexia and bulimia is understood as representations of good and bad mother objects. In anorexia nervosa the body in the state of underweight is the good mother-object ("not-mother"), the too heavy body is the bad mother-object ("like mother"). In bulimia the wish for incorporation of a good object (food before binging) and the following panic of the fusion with a bad object (food after eating) is acted out. Body and food, substituting mother objects, are manageable, the illusion of controlling self-object-boundaries is maintained. Thus anorexia and bulimia are understood as an attempt to cope with fear of fusion as well as of separation, which is revived in adolescence.