Mouse antisera specific for desmosomal adhesion molecules of suprabasal skin cells, meninges, and meningioma.

Mouse polyclonal antisera were raised to the Mr 130,000 and Mr 115,000 cell surface glycoproteins, desmocollins, of desmosomes from bovine nasal epithelium. Immunoblotting confirmed that the antisera were specific for the desmocollins. An immunofluorescence study showed that the antisera distinguished between the basal and suprabasal layers of bovine and human epidermis. The antibodies reacted with cultured keratinocytes only after calcium-induced stratification. In epidermis, therefore, there appears to be a difference between the desmocollins of basal and suprabasal cells that may be important in relation to epidermal differentiation. Previous work has shown that polyclonal antisera raised in other animals (guinea pigs and rabbits) against desmocollins, as well as against other desmosomal components, react with all desmosome-containing epithelia. In contrast, an immunofluorescence survey of bovine, rat, and human tissues showed that the present mouse antisera stained only suprabasal skin cells and the arachnoid layer of the meninges, demonstrating that these have common determinants that distinguished their desmocollins from those of all other tissues. The antibodies also stained 11 of 12 meningiomas and, therefore, may be useful as a marker not only for the diagnosis of these tumors but also for investigation of their histogenesis.     

Hexamethyldisilazane in preparation of retinal tissue for scanning electron microscopy

A new rapid procedure for desiccating frozen resin-cracked retinal tissue for scanning electron microscopy (SEM) which permits air-drying was found to compare favorably with tissues prepared by critical-point drying: Retinal tissue was fixed in 4% phosphate-buffered neutral formaldehyde, dehydrated by means of graded ethanol, embedded in Epon, cracked and washed in propylene oxide. For desiccation, the specimens were immersed in hexamethyldisilazane (HMDS), air-dried and finally sputter-coated. The method is time-saving, gives extended information in SEM, and the number of good specimens is increased.     

Neonatal reference values for ionized calcium, phosphate and magnesium. Selection of reference population by optimality criteria

Thirty-one full-term newborn babies were investigated in order to establish reference values for ionized calcium. Only children fulfilling certain optimality criteria (with best possible maternal and infant conditions and uncomplicated pregnancy and delivery) were included. All infants were breast fed. Capillary blood for analysis of ionized calcium was collected by heel puncture on day 1 (6-36 h post partum, p.p.), day 3 (60-84 h p.p.) and day 5 (108-132 h p.p.). Ionized calcium was measured with a semi-automatic electrode system ICA 1 (Radiometer A/S, Copenhagen, Denmark). The reference ranges (mean +/- 2 SD) for days 1, 3 and 5 were 1.05-1.37, 1.10-1.42 and 1.20-1.48 mmol/l, respectively. The mean ionized calcium concentration on day 1 was significantly lower than on days 3 and 5. Reference values are also given for total calcium, magnesium and phosphate. We emphasize that it is impossible to calculate ionized calcium from total calcium or vice versa.     

On the origin of apparent low tissue signals in balanced SSFP.

Balanced steady-state free precession (bSSFP) has become increasingly important in clinical applications. Its signal properties have been investigated over several years by many groups, and various critical factors for bSSFP signal intensity and stability, such as off-resonances, flow, and eddy currents, have been identified. It is generally accepted that bSSFP signal intensity is a function of relaxation times, excitation angles, and spin densities only. While this is true for simple phantoms, it appears that signals from tissues are significantly less intense than predicted by theory. This work demonstrates that the molecular origin of this apparent signal reduction is due to on-resonance magnetization transfer (MT). High flip angles in combination with very short repetition times (TRs), as commonly used for bSSFP, lead to a considerable saturation in the fraction of macromolecular (MM) pool protons. As a result, bSSFP signal is strongly attenuated by up to a factor of 2 in the human brain compared to the signal expected from theory.     

Doppler echocardiography of 119 normal-functioning St Jude Medical mitral valve prostheses: a comprehensive assessment including time-velocity integral ratio and prosthesis performance index.

The purpose of this study was to provide, in a large number of patients, comprehensive Doppler echocardiographic assessment of normal St Jude Medical mitral valve prosthesis function using Doppler-derived hemodynamic variables, including the mitral valve prosthesis-to-left ventricular outflow tract time-velocity integral ratio and prosthesis performance index. The pressure half-time was less than 130 milliseconds in all patients, and all but one patient had either a peak early mitral diastolic velocity of 2 m/s or less or a mitral valve prosthesis-to-left ventricular outflow tract time-velocity integral ratio of less than 2.2. There was a significant (P < .001) negative correlation between the prosthesis performance index and prosthesis size. This negative correlation suggests that there is more efficient use of the in vitro geometric orifice area with smaller prostheses.     

Diagnoses of the relatives of schizotypal outpatients

Relatives of 22 schizotypal probands were evaluated for lifetime psychiatric diagnoses. Forty-four (N = 44) of the 97 available relatives were interviewed directly using the Diagnostic Interview Schedule. The rates of psychiatric diagnoses were compared with those of sixty-six (N = 66) of 140 relatives of 30 depressed patients. Family history of mental illness was ascertained by the informant method on the remainder of relatives of both proband groups. The rate of depression found in the relatives of schizotypal patients was 52% in those directly interviewed and 25.7% when informants' reports on unavailable relatives are pooled with direct interview data. These rates were not significantly higher than those found for the relatives of depressed probands (34.8% by direct interview and 21% including reports from informants). The high rates of depression in the relatives of schizotypal probands may indicate that schizotypal personality is associated with affective disorder and not only with schizophrenia. However, the high rates may be due to the presence of depressive character traits in relatives, which inflate the rates of dysthymic disorder and other chronic depressive disorders in the relatives of borderline patients.