Concentrations of escitalopram in blood of patients treated in a naturalistic setting: focus on patients with alcohol and benzodiazepine use disorder.

The selective serotonin reuptake inhibitor escitalopram (ESC) is indicated for the treatment of major depressive disorder (MDD) and of generalized anxiety disorder (GAD). Monitoring of blood levels (BLs) is strongly indicated due to ESC's high interindividual pharmacokinetic variability. The aim of this study was to analyse clinical efficacy and pharmacokinetic influences on ESC BLs, in patients with depressive disorder alone and with comorbid alcohol or benzodiazepine use disorder. Data were collected from patients treated under naturalistic conditions for whom Therapeutic Drug Monitoring (TDM) was requested to guide antidepressant drug therapy and analysed retrospectively. Particular emphasis was given to patients with alcohol or benzodiazepine use disorder. Responders according to the clinical global impression (CGI) scale were compared with nonresponders for their ESC blood level (BL). The patient sample included 344 patients from 16 psychiatric hospitals in Germany. Influencing factors that could explain 22% of ESC BLs were dose, sex and age. Variability was high between individuals, and doses up to 40 mg were common in real-world settings. Patients treated with ESC monotherapy who responded showed a trend towards higher BLs compared to nonresponders with a concentration of 15 ng/mL separating both groups. Pathological changes in liver function (indicated by elevated GGT in combination with an AST/ALT ratio ≥ 1) resulted in higher dose-corrected ESC concentrations. Influencing factors that could explain 22% of ESC blood levels were dose, sex, and age. Our findings confirm the currently recommended lower threshold level and support the need for standard TDM analyses in everyday clinical practice. The ICD 10 diagnosis alcohol dependence alone does not lead to pharmacokinetic changes in the metabolism of ESC, but altered liver function does.

Mechanism of non-spliceosomal mRNA splicing in the unfolded protein response pathway.

The unfolded protein response is an intracellular signaling pathway that, in response to accumulation of misfolded proteins in the lumen of the endoplasmic reticulum (ER), upregulates transcription of ER resident chaperones. A key step in this pathway is the non-conventional, regulated splicing of the mRNA encoding the positive transcriptional regulator Hac1p. In the yeast Saccharomyces cerevisiae, the bifunctional transmembrane kinase/endoribonuclease Ire1p cleaves HAC1 mRNA at both splice junctions and tRNA ligase joins the two exons together. We have reconstituted HAC1 mRNA splicing in an efficient in vitro reaction and show that, in many ways, the mechanism of HAC1 mRNA splicing resembles that of pre-tRNA splicing. In particular, Ire1p endonucleolytic cleavage leaves 2', 3'-cyclic phosphates, the excised exons remain associated by base pairing, and exon ligation by tRNA ligase follows the same chemical steps as for pre-tRNA splicing. To date, this mechanism of RNA processing is unprecedented for a messenger RNA. In contrast to the striking similarities to tRNA splicing, the structural features of the splice junctions recognized by Ire1p differ from those recognized by tRNA endonuclease. We show that small stem-loop structures predicted to form at both splice junctions of HAC1 mRNA are required and sufficient for Ire1p cleavage.

Crystals of the chemically synthesized acceptor stem of tRNAAla from Escherichia coli diffracting to high resolution.

The acceptor stem of tRNA(Ala) from E. coli has been chemically synthesized and crystallized. This duplex contains a G.U base pair in position 3-70, which is the main identity element for alanyl-tRNA synthetase from E. coli. The crystals are stable in the X-ray beam for a long period of time and diffract to 1.7 A resolution. The monoclinic crystals reveal a C2 space group with a = 35.0, b = 47.5, c = 26.2 A, beta = 102.3 degrees and one acceptor stem per asymmetric unit.

Ultrastructure of contusion cataract.

We investigated the histopathologic condition of four lenses with contusion rosette cataract by light and electron microscopy; periods between blunt trauma and cataract extraction varied from 4 months to 40 years. The initial morphologic changes appear to be the formation of intercellular vacuoles within the lens epithelium and the swelling of superficial cortical lens fibers. Signs of beginning fiber degeneration within the edematous zone include fragmentation of fiber cytoplasm into droplets and globules, formation of abnormal membrane arrangements, and enlargement of intercellular spaces. Late rosette opacities manifest as sharply demarcated layers of vacuolic degeneration in the deeper cortex. We suggest that in contusion cataract, a traumatically induced dysfunction of the lens epithelium leads to an edema of superficial cortical lens fibers that subsequently undergo degeneration and produce a localized and permanent lamellar zone of vacuolation. With time and with the formation of new clear lens cells, this layer becomes gradually compressed and displaced deeper into the cortex.

Immunolocalization of growth factors in the human ciliary body epithelium.

Although various growth factors have been identified in the human aqueous humor, their sources have not been fully established so far. To determine, whether the ciliary body epithelium is capable of producing growth factors in vivo, we studied the immunolocalization of EGF, bFGF, IGF-I, TGF-alpha, TGF-beta and PDGF-AB in human ciliary body tissue obtained from 20 autopsy eyes (12 to 88 years; fixed within 6 hours post mortem) and 1 surgically enucleated melanoma eye using light and electron microscopic immunohistochemistry. Antibody binding was visualized by indirect immunofluorescence and immunogold labeling on differently fixed frozen and resin-embedded sections. The immunohistochemical findings indicate the production of EGF, bFGF, IGF-I, and TGF-alpha, to a minor degree also TGF-beta, particularly TGF-beta 2, by the ciliary epithelial cells, predominantly the nonpigmented cells. Ultrastructural evidence for an endogenous production included the distinct and specific labeling of secretory organelles (rough endoplasmic reticulum, Golgi complex), cytoplasmic vesicles, and the basolateral membrane infoldings. The ciliary epithelium failed to stain significantly with antibodies to TGF-beta 1 and PDGF-AB. Labeling for bFGF was found to depend on the specific antibodies and fixation conditions employed. Sequestration of bFGF and PDGF-AB in the basement membranes of the ciliary epithelium could be demonstrated under certain conditions. Peaks of labeling intensity were consistently observed at the crests of the ciliary processes and in the pars plana, suggesting regional variations in activity and secretion of growth factors into the aqueous humor and vitreous. While only PDGF-AB may be derived from the serum, it appears likely that most growth factors demonstrated are not circulating hormones but rather act as autocrine and/or paracrine factors.

Corneal endothelial involvement in pseudoexfoliation syndrome.

Information on corneal manifestation in pseudoexfoliation syndrome is restricted to specular microscopic studies. We investigated morphologic changes of the posterior cornea of two corneal buttons with Fuchs' endothelial dystrophy obtained at penetrating keratoplasty and of one enucleated glaucomatous eye from three patients with ocular pseudoexfoliation syndrome. By transmission electron microscopy, large clumps of typical pseudoexfoliation material were found adhering to the corneal endothelium and masses of pseudoexfoliation material were incorporated into the posterior Descemet's membrane. In the affected areas, the endothelial layer appeared irregular and discontinuous, with loosely adherent, degenerating cells producing pseudoexfoliation fibers and fibroblastic cells spreading to cover denuded Descemet's membrane. The present findings indicate that the pseudoexfoliation material is initially formed by degenerative endothelial cells and that it becomes subsequently buried by overgrowing cells. The corneal endothelial involvement may potentiate complications of cataract surgery and open angle glaucoma in patients with pseudoexfoliation syndrome.

Congenital zonular cataract. Clinicopathologic correlation with electron microscopy and review of the literature.

A whole subluxated lens with a congenital zonular cataract was obtained after intracapsular extraction from an 83-year-old patient for histopathologic examination. The first electron microscopic description of a congenital zonular cataract revealed the presence of many globules ranging in diameter from 0.1 to 2.5 microns, occasionally accompanied by enlarged intercellular spaces and a few multilamellar bodies. Most of the globules were arranged concentrically around the nucleus like a shell, and only a few globules were concentrated in nodular aggregates in the nucleus. Ultrastructural indications of the relationship between globules and lens fiber membranes have substantiated the idea of the transformation from normal lens fibers into cataractous fibers by primary breakdown of the lens fiber membranes and secondary degeneration or liquefaction of the fiber contents.

Pseudoexfoliative material in the eyelid skin of pseudoexfoliation-suspect patients: a clinico-histopathological correlation.

The pseudoexfoliation (PSX) syndrome has recently been suggested to represent the intraocular manifestation of a systemic disorder. In the present study, we examined the correlation between the extraocular occurrence of PSX material in eyelid skin and clinical indications of early stages of PSX syndrome using transmission and immunoelectron microscopy. Typical PSX aggregates were demonstrated in 7 of the eyelid-skin biopsy specimens taken from 12 patients who had been categorized as "PSX suspects" on the basis of certain clinical signs related to loss and dispersion of melanin from the iris pigment epithelium and to iris stromal atrophy but showed no clinical evidence of PSX syndrome in either eye. Another 3 lid specimens obtained from PSX suspects exhibited signs of atypical PSX fibrillopathy. The PSX deposits revealed immunolabeling for heparan and chondroitin sulfate proteoglycan, entactin/nidogen, elastin, amyloid P, and vitronectin. These findings suggest that certain clinical signs indicating early PSX syndrome obviously correlate with the extraocular occurrence of PSX material before its clinically visible appearance on the surfaces of the anterior and posterior chambers.

Immunohistochemical localization of basement membrane components in pseudoexfoliation material of the lens capsule.

The pseudoexfoliation (PSX) syndrome has long been speculated to be a disorder of disturbed basement membrane metabolism. To test this concept, we investigated the presence of all principal basement membrane components in precapsular PSX deposits of 30 anterior lens capsules by immunofluorescence and electron microscopic immunogold techniques. We have shown heparan sulfate and chondroitin sulfate proteoglycans, laminin, entactin/nidogen, fibronectin, and amyloid P protein to be an integral constituent of PSX material; type IV collagen was restricted to a microfibrillar layer interposed between capsular surface and typical PSX material. The additional presence of elastin epitopes indicates that the PSX material is a multicomponent expression of a disordered extracellular matrix synthesis including the incorporation of the principal noncollagenous basement membrane components. The extensive labelling of PSX material for chondroitin sulfate suggests an overproduction and abnormal metabolism of glycosaminoglycans to be one of the key changes in this disorder.

Precapsular layer of the anterior lens capsule in early pseudoexfoliation syndrome.

We examined a possible correlation between clinical signs of early pseudoexfoliation (PSX) syndrome related to pigment dispersion and iris stroma atrophy and morphological alterations of the lens capsule. 63 anterior lens capsules (30 PSX suspects, 3 pre-PSX, 10 PSX, 20 controls) were studied by transmission and immuno-electron microscopy (TEM). In 20 PSX suspect and 3 pre-PSX capsulotomy specimens, TEM revealed a precapsular layer (0.1-11 microns in thickness) composed of microfibrils, amorphous material, and granular inclusions. The incidence of this fibrillar layer was significantly higher (p = 0.001) in PSX suspect and pre-PSX eyes than in controls (5 positive). Ultrastructural and immunohistochemical similarities of the fibrillar surface network in PSX suspect and typical PSX specimens indicate that the precapsular layer may represent a precursor of PSX. The beginning PSX process in the eye is obviously indicated by certain clinical signs.

[Immunoglobulin and total protein concentrations in saliva of healthy children (author's transl)]. / Immunglobulin- und Totalproteinkonzentrationen im Vollspeichel gesunder Kinder.

The investigation of Immunoglobulins-and Total protein concentrations in saliva of healthy children shows an agreement with literature, a maturation in individual development of the saliva-producing organs in the mouth.