Desquamin is an epidermal ribonuclease

Desquamin is a glycoprotein that we have isolated from the upper granular layer and the stratum corneum of human epidermis; it is not ordinarily expressed in submerged cultures, whose terminal differentiation stops short of formation of these layers. The exogenous addition of desquamin to human cultured keratinocytes extended their maturation, and hematoxylin staining indicated a loss of cell nuclei. For confirmation, cultured cells were lysed in situ, and the nuclei were incubated with desquamin for several days, then stained with hematoxylin. Damage to the nuclei was evident: the nuclear inclusions remained intact, while the surrounding basophilic nuclear matrix was degraded. Desquamin was then tested directly for nuclease activity. Ribonuclease activity was determined by incubating desquamin with human epidermal total RNA and monitoring the dose-dependent disappearance of the 28S and 18S ribosomal RNA bands in an agarose/formaldehyde gel. On RNA-containing zymogels, we confirmed the RNase activity to be specific to desquamin. Using synthetic RNA homopolymers, we found the active RNase domains to be limited to cytosine residues. On the contrary, DNA was not degraded by an analogous procedure, even after strand-separation by denaturation.

Are patients satisfied with results from residents performing aesthetic surgery?

An 8-year survey of patient satisfaction in an academic aesthetic surgery clinic at the University of Toronto was carried out by means of a mailed questionnaire. A total of 265 questionnaires were mailed; 131 completed questionnaires (49.4 percent) were returned. Of these, 93.1 percent would recommend this clinic (88.1 percent in the first year of operation and 95.4 percent in the subsequent 7 years), and 92.9 percent would undergo the same procedure again, if required (88.3 percent in the first year and 95.0 percent in the next 7 years). The highest patient satisfaction (10 of 10) was seen in augmentation mammoplasty (average, 9.1); blepharoplasty (average, 9.0); rhytidectomy (average, 7.8), and rhinoplasty (average, 6.9). The results obtained compared favorably with recently published data of more experienced surgeons.

Perinatal myocardial infarction in a newborn with a structurally normal heart

Myocardial infarction in a newborn infant in the absence of congenital heart disease and anomalous coronary artery anatomy is extremely rare. We report a case of a newborn with a structurally normal heart who presented shortly after birth with congestive heart failure and cardiovascular collapse suggestive of a hypoplastic left ventricle or critical aortic stenosis. This newborn had a massive myocardial infarction caused by thromboembolic occlusion of the left main coronary artery. Clinical, laboratory, and autopsy data suggest the event occurred in utero.

Transurethral microwave thermotherapy (Prostatron version 2.5) compared with transurethral resection of the prostate for the treatment of benign prostatic hyperplasia: a randomized, controlled, parallel study

OBJECTIVE

To compare transurethral microwave thermotherapy (TUMT) with urethral cooling in a high-energy protocol (Prostatron version 2.5), with transurethral resection of the prostate (TURP) for the treatment of symptomatic, uncomplicated, urodynamically obstructive benign prostatic hyperplasia (BPH).

PATIENTS AND METHODS

Patients with moderate to severe symptomatic, uncomplicated BPH, unequivocally obstructed as assessed from the Abrams-Griffith nomogram, who were technically suitable for either form of treatment, were randomized into two groups of 30 patients each to undergo either TUMT or TURP. Five efficacy variables, i.e. the American Urological Association (AUA) symptom score, maximum flow rate (Qmax), post-void residual urine volume (PVR), voiding pressure at maximal flow (Pdet max) and prostatic volume determined by ultrasonography (PV) were measured initially and 6 months after treatment using a defined protocol. Complications were recorded during and up to 6 months after the treatment. As the variables were independent, the data were analysed using a paired t-test for each to assess the treatment effect for each group.

RESULTS

After TURP, all the variables improved significantly; after TUMT, the symptoms improved both clinically and statistically (P < 0.001), with the mean AUA symptom score decreasing from 18.4 to 5.2. However, none of the objective variables improved after TUMT. The energy delivered under software control correlated poorly with prostatic volume (r = 0.322). TUMT had considerably lower morbidity than TURP, but failure of ejaculation occurred in four of 18 sexually active men after TUMT.

CONCLUSIONS

Despite considerable improvement in their symptoms, TUMT using the Prostatron and Prostasoft v2.5 did not alleviate obstruction in patients with BPH. Patients treated using TUMT controlled by this software should be informed of the possibility of ejaculatory dysfunction.

Posturography and balance problems in older people

OBJECTIVE

To determine which measurements and test conditions on posturography are most useful for identifying balance problems in older people.

SUBJECTS

Two samples of 70 community-dwelling older subjects (> 75 years). One group (controls) considered their balance normal for their age, and the other (patients) complained of imbalance.

MEASUREMENTS

Velocity of sway on static (with and without foam) and dynamic posturography, Tinetti gait and balance score, self-reported fear of falling, and number and circumstances of falls.

RESULTS

Mean sway velocity was significantly increased in patients compared with controls. The greatest difference between patients and controls occurred with measures of anterior-posterior sway velocity during angular tilt of the platform. Sway velocity was not significantly increased in patients or controls who reported falls compared with those who did not report falls. Even when comparing those who fell as a result of loss of balance with those who fell because of trips or slips, there was no significant difference in sway velocity. By contrast, those who reported fear of falling (patients and controls) had significantly increased sway velocity compared with those who did not report fear of falling.

CONCLUSION

On average, velocity of sway (particularly in the anterior-posterior direction) is higher in older subjects who complain of imbalance compared with age-matched controls, and the difference is greater with dynamic posturography than with static posturography. However, the posturography data provided little information about the cause of the imbalance and did not correlate with the frequency of reported falls.

Enzymatic activity of desquamin

We have previously described the properties of desquamin, a cell adhesion molecule in the stratum corneum with lectin-like properties specific for amino sugars. We report here that desquamin is also a trypsin-like serine proteinase. It degrades several chromogenic peptides with arginine in the P1 position, with greatest activity for the tissue plasminogen activator peptide; it has no chymotrypsin-like activity. The enzymatic activity of desquamin is inhibited by aprotinin, leupeptin, and soybean trypsin inhibitor. The Km for all active substrates is in the millimole range and the pH for optimal activity is near 10. The enzymatic activity is stable in the temperature range from 37 to 80 degrees C, peaking near the upper end; it is only partially inhibited at 100 degrees C. Using zymogels with immobilized substrates, we show that desquamin degrades both casein and human keratins. Because desquamin is localized to the lipid envelopes of the stratum corneum and can function as an enzyme (and is extremely resistant to chemical and thermal degradation), it is in a position to play a crucial role in desquamation.

Predesquamin extends maturation of cultured keratinocytes

Predesquamin is a glycoprotein that we have isolated from human epidermis. Its monospecific polyclonal antibody immunolocalizes to the lower stratum corneum. We have previously found that it is not expressed ordinarily in primary keratinocyte cultures, but that it is expressed in a serum-containing medium that is supplemented with interferon-gamma. Under these conditions, we observed larger outer squames and a more mature pattern of desquamation. We now demonstrate, by adding predesquamin directly to the culture medium without the cytokine, that the morphological changes are caused by predesquamin (and the role of IFN-gamma in the previous experiment was to stimulate the expression of predesquamin).

Jugular venous bypass for subclavian vein obstruction

Symptoms of chronic subclavian occlusion including swelling and pain may be disabling. In the case presented a patient with disabling symptoms 18 years after ligation of the right subclavian vein during resection of a chest wall tumor is successfully treated with a single-anastomosis internal jugular venous bypass.

Comparison of static and dynamic posturography in young and older normal people

OBJECTIVE

To measure sway velocity during static and dynamic posturography in "normal" older people and to determine which tests best distinguish young from older subjects.

SUBJECTS

A sample of 30 young (18-39 years) and 82 community-dwelling older (> 75 years) subjects who reported normal balance underwent a battery of balance tests.

MEASUREMENTS

Velocity and frequency of sway, Tinetti gait and balance score, self-reported fear of falling and number of falls.

RESULTS

Mean sway velocity and the ratio of high to low frequency sway velocity were significantly increased in older subjects compared with younger subjects for static and dynamic tests with eyes open and with eyes closed. Measures of anterior-posterior sway velocity during angular tilt of the platform with eyes closed best distinguished young from older subjects (almost three-fourths of older subjects had values greater than 2 standard deviations from the young normal mean). Older subjects who reported falls in the past year did not have a significantly higher sway velocity on static or dynamic tests compared with those who did not report falls. However, subjects who reported a fear of falling had significantly higher sway velocity on dynamic tests with eyes closed compared to those who did not report a fear of falling.

CONCLUSIONS

On average, velocity of sway is higher in older subjects compared with younger subjects, and the difference between young and old is greater with dynamic posturography than with static posturography.

Cytokines modulate terminal differentiation and the expression of predesquamin in cultured keratinocytes

Predesquamin is a glycoprotein that we have isolated from human epidermis. Its monospecific polyclonal antibody immunolocalizes to the lower stratum corneum. We have previously found that it is not expressed in primary keratinocyte cultures unless both interferon-gamma and serum are added to the culture media. We now show similar results with interleukin-1 alpha substituted for interferon-gamma (but not with retinoic acid). Predesquamin is expressed in media supplemented with both cytokines (with or without serum), accompanied by the observation of larger outer squames and a more mature pattern of desquamation. As both cytokines are naturally present in the epidermis, this suggests that they contribute to desquamation in vivo. The predesquamin expression is demonstrated by Western blots of cell extracts with the specific antibody. Corresponding morphological changes are illustrated by phase-contrast microscopy.

Predesquamin inhibits desquamation

Predesquamin is a Con A binding glycoprotein from human epidermis, with a molecular weight of 650 kDa. Its isolation and characterization are detailed, as well as the preparation of a polyclonal antibody to it. The antibody labels primarily the lower stratum corneum in fluorescent and ultrastructural immunolocalization, both in normal skin and plantar callus. A desquamation model system, in which plantar callus is incubated with the chelating agent ethylenediaminetetraacetic acid (EDTA) is refined by substituting for EDTA the Ca(2+)-specific ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid. Moreover, the shedding activity can be suppressed by raising the Ca2+ concentration. Within this model, it is demonstrated that predesquamin at nanomolar concentrations inhibits squame shedding in a dose-dependent manner. We conclude that predesquamin plays an important role in blocking premature desquamation of the lower stratum corneum.

Assessing what high risk young children know about drugs: verbal versus pictorial methods

Very young children are generally not targeted for drug education efforts for two basic reasons. First, it is generally assumed that young children are not cognitively ready to learn about specific drugs through systematic drug prevention efforts. And second, it is difficult to measure pre- and posttest changes on the part of young children if drug education intervention is instituted. This study involved measuring what children three to eight years old learned from systematic drug education over the course of eight months. Two assessment methods were compared: pictorial and verbal interviews. The posttest results revealed that the children who received the intervention knew significantly more about several drugs than a matched comparison group. Both methods were useful in providing a comprehensive view of what the children knew about alcohol and other drugs.

Culture of basal cell carcinoma

Studies of basal cell carcinoma have been hindered by a lack of a suitable and reproducible tissue-culture model system. We have succeeded in growing this tumor in primary culture from eight different patients. We can separate and grow the tumor cells and the stromal cell component. We also culture normal keratinocytes and fibroblasts from the same patient for comparative studies. All the cell types have been subcultured four to five times and cryopreserved. The normal keratinocytes were indistinguishable from the tumor cells in ploidy, in rate of growth, and in the failure to express ICAM-1. Both cell types also fail to synthesize the matrix proteins: types I and IV collagens. Differences were noted in the expression of fibronectin and the bullous pemphigoid antigen, with the normal cells expressing the antigens although the tumor cells did not. Interferons exogenously added to the culture media preferentially killed the basal cell carcinoma cells, as compared to normal keratinocytes from the same patients. We believe that our culture system opens possibilities for biochemical and molecular studies of this disease, and for in vitro testing of antitumor agents for clinical therapy.

Interferon-gamma modulates terminal differentiation and the expression of desquamin in cultured keratinocytes

Interferon (IFN)-gamma has been shown to modulate cell differentiation and the expression of cell surface molecules of cultured human keratinocytes; it also induces cell shedding. We have previously described the properties of desquamin, a cell surface adhesion molecule from the stratum corneum. We report here on the impact of IFN-gamma on the expression of desquamin. We document the related morphological changes in terminal differentiation. We cultured human keratinocytes in three different culture systems: in serum-free medium at low Ca2+ (0.1 mM), at high Ca2+ (1.5 mM), and at high Ca2+ with 10% serum. IFN-gamma (100 U/ml) was added to each culture system after overnight incubation. In all cases, IFN-gamma induced an altered phenotype, as shown by phase contrast and electron microscopy. We exposed cultured cells to antibodies to the desquamins (glycoproteins from the stratum corneum). Immunoflurescent localization and Western blotting showed that the desquamins were expressed only under culture conditions where both serum and IFN-gamma were present. The induction of desquamin expression by IFN-gamma coupled with an increase in cell shedding, suggests that we have developed a suitable culture system for the study of desquamation in vitro.

Grafting of leg ulcers with undifferentiated keratinocytes

A procedure for transplanting cultured human keratinocytes has been developed and used successfully to treat patients with persistent leg ulcers. Shave excisions of donor skin of 1 cm2 or less were expanded in culture in 1 week to cover wounds as large as 90 cm2. The uniqueness of this system is the use of a biochemically modified surgical dressing that permits the transplantation of undifferentiated cells. Several hours after inoculation, trypsinized single cells become attached to the dressing and are ready for grafting. Seven of eight persistent stasis ulcers completely reepithelialized after application of the modified surgical dressing with undifferentiated keratinocytes.

Sensitivity of desquamin to proteolytic degradation

The stratum corneum is both a desquamating and degradative tissue; cell contacts become weaker in the outer lamellae and a variety of proteolytic and glycolytic enzymes cleave many macromolecules into free amino acids and saccharides. We have reported on a 40-kilodalton glycoprotein from human stratum corneum; because of its unique lectin-like properties, we believe that it plays a major role in desquamation and have named it desquamin. If desquamin is to function as a lectin during desquamation, it must survive enzymatic degradation in the outer stratum corneum. Accordingly, we treated this glycoprotein with a number of proteinases and found that desquamin is resistant in vitro to most of the types of proteinases that have been reported in the stratum corneum as well as several others that have not been identified as present in the tissue. In the stratum corneum, the lipids of the intercorneal mortar shield the glycoproteins; hence, desquamin is even less likely to be susceptible to endogenous proteolysis in vivo than in vitro.

Regional blood flow of the canine vocal cord: the microsphere surface technique

The vocal fold's microcirculation has been well described, but there are few reports regarding the blood flow to this region. A number of methods have been used to evaluate the blood flow to an organ system. Among the most sensitive is the microsphere surface technique, which has been used to measure blood flow in many organ systems, including the cochlea. In this study, the blood flow to the canine vocal fold was assessed using the microsphere surface technique. Overall flow was measured, as well as flow to the lamina propria and muscularis layers. The technique and the results are reported.

Procaterol metered-dose inhaler: a multiclinic study evaluating the efficacy and safety in patients with asthma

Procaterol hydrochloride aerosol, a potent beta 2-adrenergic bronchodilator, was evaluated in a double-blind, placebo-controlled study for efficacy and safety in 210 patients with documented mild to moderate reversible airway obstruction. Patients were randomized to receive procaterol in two inhalations (high dose) or one inhalation (low dose), 0.01 mg/inhalation, three times daily, or placebo. Pulmonary function tests were recorded at five and 30 minutes and hourly for eight hours after the first dose and following 1 and 2 weeks of treatment. Both doses of procaterol produced significantly greater improvement in PFTs at one hour and for up to seven hours after dosing compared with placebo (p less than 0.05). Mean percent increases in FEV1 were 35% in the high-dose group and 29% in the low-dose group at week 2. The high-dose group showed no loss of duration of bronchodilation with continued dosing. Improvement in PFTs and peak flow rates was significantly greater in the high-dose than in the low-dose group (p less than 0.05). Tremor was the most frequent side effect. Procaterol had no effect on electrocardiograms, heart rate, blood pressure, or clinical laboratory tests. The high dose of procaterol aerosol was shown to be an effective and well-tolerated bronchodilator with a rapid onset and long duration of action.