Adherence of Candida albicans to epithelial cells: studies using fluorescently labelled yeasts and flow cytometry

Candida albicans adherence to epithelial cells is the first step in the infectious process, but in spite of its importance, current methods for the quantitative measurement of adherence of C. albicans to epithelial cells in vitro have some serious limitations. They are based on filtration assays and either microscopic or radiometric analysis. The adherence reaction is usually carried out with a large excess of yeasts (100-fold) over epithelial cells in order to perform the microscopic analysis, which is slow, subjective and limited to 100-200 cells and thus lacks statistical power. The radiometric analysis fails to measure individual cells. A method for measuring yeast adherence that overcomes these problems has been developed. It is based on labelling the yeasts with the fluorogenic marker 2',7'-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein acetoxymethyl ester (BCECF) prior to the adherence reaction, and analysing 10(4) epithelial cells by flow cytometry, while nonbound yeasts are excluded by gating. Two subpopulations of buccal epithelial cells (BECs) which differ in their mean fluorescence intensities per cell (MFIs) were observed: one with MFI which did not exceed nonspecific fluorescence, and the other with MFI as high or higher than the MFI of labelled yeasts. The two subpopulations represent yeast-free and yeast-binding epithelial cells, respectively, and the MFI increment of the BECs is a quantitative measure of the extent of yeast adherence. Control experiments confirming previously described basic features of adherence, such as enhanced adherence at increasing yeast excess, diminished adherence of trypsin-treated or heat-inactivated yeasts, and the differential adherence of various Candida species, supported the validity of the assay. The possibility of studying adherence reliably at low yeast:epithelial cell ratios, which better mimic adhesion as it occurs in vivo, is an important advantage of the assay. New findings, using this method, included the observation that exfoliated BECs from diabetic patients exhibited the same capacity for C. albicans adherence as cells from healthy controls, and that epithelial cells from early human ontogenic stages had a significantly lower adherence level than those from later stages.

Hereditary leukoencephalopathy and palmoplantar keratoderma: a new disorder with increased skin collagen content

We report a new neurocutaneous syndrome of apparent autosomal recessive inheritance consisting of early-childhood-onset palmoplantar keratoderma followed in adulthood by progressive tetrapyramidal syndrome and cognitive impairment. Of the four affected siblings, two were available for evaluation. Investigation disclosed cerebral white-matter involvement on MRI and arylsulfatase A pseudodeficiency carrier state, which was also identified in clinically unaffected family members. Since skin biopsies showed dermal connective tissue abnormalities, we studied collagens I, III, and VI biosynthesis. Northern blotting of RNA extracted from cultured skin fibroblasts revealed an increased steady-state messenger RNA (mRNA) level of alpha 1(VI) collagen, whereas no differences were detected for pro alpha 1(I), pro alpha 1(III), and tropoelastin mRNAs. The skin content of collagen and total protein was higher in the patients than in controls. We suggest that an extracellular matrix abnormality may be involved in the pathogenesis of this disorder.

Efficacy of doxycycline and tetracycline in ocular rosacea

We compared the effects of doxycycline and tetracycline hydrochloride on the subjective symptoms in ocular rosacea. Twenty-four patients with symptomatic ocular rosacea were randomly assigned to two groups and treated with doxycycline 100 mg/day (group 1, 16 patients) or tetracycline hydrochloride 1 g/day (group 2, eight patients). The dosages of each drug were gradually tapered and discontinued according to symptomatic response. At each examination all the manifesting symptoms were scored by the patients. Patients were followed up from six weeks to three years. After six weeks of drug treatment, all patients except one had symptomatic improvement. Although most of the scores of the symptoms were significantly decreased in both groups, greater symptomatic relief occurred in the tetracycline hydrochloride-treated patients (P = .041). However, after three months of treatment there was no significant difference in symptoms between the two groups. Gastrointestinal tract complications occurred in two of the 16 patients (12.5%) in group 1 and in three of the eight patients (37.5%) in group 2. Both tetracycline hydrochloride and doxycycline can control the symptoms of ocular rosacea.

The use of doxycycline and tetracycline in ocular rosacea

The authors compared the effects of doxycycline and tetracycline hydrochloride on subjective symptoms in ocular rosacea. Twenty-four patients with symptomatic ocular rosacea were prospectively treated with doxycycline 100 mg/day (group 1, n=16) or tetracycline hydrochloride 1g/day (group 2, n=8). The dosages of each drug were gradually tapered and discontinued according to symptomatic response. Patients were followed from six weeks to three years. In group 1, 15 patients (94%) had symptomatic improvement (12 patients were asymptomatic and three symptomatically improved), and two patients (13%) had gastrointestinal tract (GIT) complications followed by discontinuation of medication. In group 2, seven of the eight patients (87%) were asymptomatic and one patient (13%) had symptomatic improvement; three patients discontinued the use of tetracycline as a result of GIT complaints. This study indicates that both tetracycline hydrochloride and doxycycline can control the symptoms of ocular rosacea.

Binding modes of IgG from pemphigus autoimmune sera onto guinea pig keratinocytes and the fate of bound IgGs

Pemphigus is an intraepidermal autoimmune blistering disease of humans caused by circulating IgGs. We have investigated the binding mode and the fate of bound antibodies from Pemphigus sera (P-IgG) on guinea pig keratinocytes in suspension in order to find clues to the loss of cell adhesion in vivo (acantholysis). Flow cytometry, following indirect immunofluorescent labeling of the keratinocytes, and dead cells' staining with ethidium bromide, demonstrated the specific surface binding of P-IgG onto living keratinocytes only. This was shown with several Pemphigus sera or purified P-IgG. This technique, used with various Pemphigus sera, showed that the specific binding is increased when the serum titer is higher, and "Km" values for P-IgG were roughly and inversely correlated to the titers. Upon saturation the same average number of Pemphigus IgG sites per cell were found for the sera of different patients. Analysis of the specific binding of [125I]-P-IgG onto Percoll-separated (living) keratinocytes showed the existence of two classes of sites: 2 x 10(6) sites/cell high-affinity sites (Kd = 1.5 x 10(-6) M total IgG) and 25 x 10(6) sites/cell low-affinity sites (Kd = 6 x 10(-5) M total IgG). Cell sorting and flow cytometry of individual cells allowed us to correlate the light-scattering signal, the RNA content, the size and morphology, and the P-IgG binding to the cells. The results indicated that P-IgG binding is homogeneous within the living keratinocytes and increases with cell size (cell maturity). Cell-sorter analysis of cells with membrane-bound P-IgG, coupled to direct determination of P-IgG released in the medium, revealed the fate of bound P-IgG: 40-60% of the P-IgGs were released in the medium within 30 minutes at 37 degrees C. This was accompanied and followed by a much slower, metabolic energy-dependent, internalization process of the membrane-bound P-IgG. The internalization has been confirmed by electron microscopy of bound P-IgG labeled with protein A-gold. Internalized IgGs were seen in the cells in coated membranous vesicles and other endocytic compartments. Similar behavior was also observed with two other membrane ligands: i.e., concanavalin A and multispecific rabbit "antisurface" antibodies.

Seasonal variation of UV radiation at the Dead Sea

Pilot measurements were made of natural UV radiation (UVA and UVB, broad-band and erythemogenic) on the Dead Sea (400 m below sea level) and in Spain at sea level, both at approximately the same geographical latitude. Measurements were made at different times of single days during the 1985/1986 season. The preponderance of UVA over UVB was more pronounced in winter.

Aminophylline versus doxapram in idiopathic apnea of prematurity: a double-blind controlled study

A double-blind controlled study, in two parts, was undertaken to compare the effectiveness of aminophylline and doxapram therapy in idiopathic apnea of prematurity. In the first part of this study, eight of 15 infants responded to doxapram therapy with complete cessation of apneic spells and six of 11 infants responded similarly to administration of aminophylline. These differences were statistically insignificant. In the second part of the study, assessment was made of whether the addition of doxapram to aminophylline therapy was effective in treatment of apnea of prematurity that had been unresponsive to aminophylline alone. Of ten infants who continued to have apneic spells during treatment with aminophylline, eight responded to the addition of doxapram with complete cessation of apnea. Nine infants received placebo in addition to aminophylline, and none had a reduction in frequency of apnea.

Idiopathic apnoea of prematurity treated with doxapram and aminophylline

Doxapram infusion was given to five preterm infants in whom therapeutic concentrations of theophylline had failed to control episodes of apnoea. Doxapram successfully controlled the apnoea, the arterial blood PCO2 value decreased significantly, and no side effects were reported.

Basal cell carcinoma developing in a nevus flammeus

A 44-year-old man with Sturge-Weber syndrome developed a basal cell carcinoma at the site of a nevus flammeus on his right cheek, which had been treated with a course of grenz rays at six years of age without obvious improvement. He also exhibited erythematous papulovesicular lesions on the upper trunk, which histologically proved to be transient acantholytic dermatosis. The association of nevus flammeus and basal cell carcinoma is extremely rare; to the best of our knowledge, only four similar cases have been previously reported.

Normalization of the dexamethasone suppression test at discharge from hospital. Its prognostic value

Fourteen patients with RDC diagnosis of primary, endogenous, major depressive disorder were studied in an inpatient setting. All were non-suppressors on the Dexamethasone Suppression Test on admission to hospital and were retested at discharge. Over 70% of patients continued to be non-suppressors at discharge, when in clinical remission. Four out of 14 patients converted to normal suppression. All 10 of the non-normalizers did poorly on follow-up: 3 patients committed suicide. All normalizers did well. Non-normalization of the DST at discharge from hospitalization may be more common than previously suspected and predicts poor clinical outcome.

Necrotising enterocolitis in the very low birthweight infant: expressed breast milk feeding compared with parenteral feeding

The incidence of necrotising enterocolitis (NEC) in very low birthweight infants (VLBW less than or equal to 1500 g) was reduced by the delayed onset of enteral feeding. Eight (18%) out of 44 VLBW infants who were in hospital during the first year of the study developed NEC. During the next 12 months 85 similar infants were initially fed by parenteral nutrition only, and then from age 14-21 days with infant formula. During the second year only 3 (3%) patients developed NEC. There were no other relevant changes in management. Throughout the entire study, the onset of NEC in each infant in whom it occurred was after the start of enteral feeding. We recommend avoiding enteral feeding in VLBW infants during the period that they are particularly vulnerable--namely the first 2 or 3 weeks of life.

Exchange transfusion in newborns via a peripheral artery and vein

Exchange transfusion using a peripheral artery and vein was carried out 18 times in 17 newborn infants. The arteries use to withdraw blood were the radial [13], the ulnar [3] an the posterior tibial [2]. Infusion of blood was carried out simultaneously through a peripheral vein. There was no mortality or morbidity directly associated with the procedure. We recommend this technique for exchange transfusion in general, and especially in the very ill newborn.