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Biomedical subjects

F Kuhn

Publications and source records attributed to F Kuhn.

At least 19 recordsLinked to original sources

The Birmingham Eye Trauma Terminology system (BETT).

PURPOSE: To evaluate the international eye injury scene and design a standardized terminology for mechanical eye injuries. METHODS: Surveys of practicing ophthalmologists and an extensive review of the international ocular trauma literature. Development of the Birmingham Trauma Terminology (BETT) using a logic-based approach. RESULTS: BETT always uses the entire globe as the tissue of reference. Its well-defined terms encompass all types of mechanical eye injury. A one-to-one relationship exists between terms and clinical conditions. CONCLUSION: BETT provides an unambiguous, consistent, simple, and comprehensive system to describe any type of mechanical globe trauma. Endorsed by several societies and peer-reviewed journals as the standardized international language of ocular traumatology, BETT is expected to become the preferred terminology for categorizing eye injuries in daily clinical practice.

Eye Injuries↗

A proactive treatment approach for eyes with perforating injury.

BACKGROUND: Perforating injuries continue to have a poor prognosis with less than two-thirds of eyes having at least ambulatory final vision, due to proliferation originating from the exit wound. MATERIALS AND METHODS: We developed a new, proactive treatment method, which is applicable in most eyes with perforating trauma. The strategy involves limited, indirect ophthalmoscopic vitrectomy during the primary repair; heavy topical corticosteroid therapy postoperatively; and complete vitrectomy on day 3, including prophylactic retinectomy around the exit wound, evacuation of subretinal blood, laser retinopexy, and silicone oil implantation. RESULTS: In the five consecutive eyes in which the proactive treatment approach was used, no "enscarceration" of the retina into the exit wound, proliferative vitreoretinopathy, retinal detachment, or retinal folding has occurred. The median visual acuity improved from count fingers to 0.6 in the three eyes without macular involvement. CONCLUSIONS: Far-reaching conclusions must not be made based on such a small series, but the proactive treatment approach appears promising in preventing proliferation-related complications such as tractional retinal detachment or retinal fold development. A similar approach should be considered for eyes with deep impact trauma from intraocular foreign bodies and in eyes with retinal incarcerated retina in the rupture wound.

Combined Modality Therapy↗

Serious eye injuries caused by bottles containing carbonated drinks.

AIM: To analyse serious eye injuries caused by bottles containing pressurised drinks. METHODS: Retrospective review of the databases of US, Hungarian, and Mexican eye injury registries. RESULTS: In the combined database (12 889 injuries), 90 cases (0.7%) were caused by bottle tops or glass splinters. The incidence varied widely: 0.3% (United States), 3.1% (Hungary), and 0.9% (Mexico), as did the agent. Champagne bottle corks were responsible in 20% (United States), 71% (Hungary; p<0.0001), and 0% (Mexico). Most eyes improved, but 26% remained legally blind. CONCLUSIONS: The presence of warning labels on champagne bottles appears to reduce cork related eye injuries, as does using plastic bottles and caps.

Adolescent↗

Choroidal detachment and expulsive choroidal hemorrhage.

ECH occurring during open globe surgery is no longer synonymous with loss of the eye. If the eye is closed immediately (i.e., the hemorrhage does not become expulsive) and modern secondary reconstruction techniques are applied, the prognosis is good. Prophylaxis, however, is the ultimate goal, achieved by a conscious consideration of all risk factors and planning of the surgical intervention accordingly ECH nevertheless can occur, for which the surgeon must be mentally prepared and then act swiftly, based on a previously designed strategy. All ophthalmologists performing (especially open globe) surgery should remain alert. Although new techniques such as small, self-sealing incisions and phacoemulsification have lowered the ECH risk, it is still not zero. (3,44,71) Once the wound is closed and the bleeding has stopped, maneuvers such as drainage or even proceeding with the original surgery can be considered, but the risks of such a course must be carefully analyzed first. Comprehensive secondary reconstruction is best placed in the hands of specialists.

Choroid Diseases↗

The Caenorhabditis elegans Ldb/NLI/Clim orthologue ldb-1 is required for neuronal function.

LIM homeodomain (LIM-HD) and nuclear LIM-only proteins play important roles in a variety of developmental processes in animals. In some cases their activities are modulated by a nuclear LIM binding protein family called Ldb/NLI/Clim. Here we characterize the Ldb/NLI/Clim orthologue ldb-1 of the nematode Caenorhabditis elegans. Two alternatively spliced variants exist, which differ in their amino-termini. The ldb-1 orthologue of Caenorhabditis briggsae has the same structure as that of C. elegans and is highly conserved throughout the open reading frame, while conservation to fly and vertebrate proteins is restricted to specific domains: the dimerization domain, the nuclear localization sequence, and the LIM interaction domain. C. elegans ldb-1 is expressed in neurogenic tissues in embryos, in all neurons in larval and adult stages, and in vulval cells, gonadal sheath cells, and some body muscle cells. C. elegans LDB-1 is able to specifically bind LIM domains in yeast two-hybrid assays. RNA inactivation studies suggest that C. elegans ldb-1 is not required for the differentiation of neurons that express the respective LIM-HD genes or for LIM-HD gene autoregulation. In contrast, ldb-1 is necessary for several neuronal functions mediated by LIM-HD proteins, including the transcriptional activation of mec-2, the mechanosensory neuron-specific stomatin.

Amino Acid Sequence↗

Lectins and traffic in the secretory pathway.

Evidence is accumulating that intracellular animal lectins play important roles in quality control and glycoprotein sorting along the secretory pathway. Calnexin and calreticulin in conjunction with associated chaperones promote correct folding and oligomerization of many glycoproteins in the endoplasmic reticulum (ER). The mannose lectin ERGIC-53 operates as a cargo receptor in transport of glycoproteins from ER to Golgi and the homologous lectin VIP36 may operate in quality control of glycosylation in the Golgi. Exit from the Golgi of lysosomal hydrolases to endosomes requires mannose 6-phosphate receptors and exit to the apical plasma membrane may also involve traffic lectins. Here we discuss the features of these lectins and their role in glycoprotein traffic in the secretory pathway.

Amino Acid Sequence↗

A steep thermal gradient thermotaxis assay for the nematode Caenorhabditis elegans.

The nematode Caenorhabditis elegans with its well-described nervous system is one of the multicellular organisms of choice to study thermotaxis. The neuronal circuitry for thermosensation has been analyzed at the level of individual cells. Two methods have previously been described to study the behavior of C. elegans with respect to temperature: 1) isothermal tracking assays and 2) linear thermal gradients (Hedgecock and Russell, 1975). Here we present a short linear thermal gradient assay which is faster and which allows statistical evaluation of different populations using a thermotaxis index. Thin agar plates are used on which a temperature gradient from about 10 degrees to 30 degrees is induced over the distance of about 5 cm. The short linear thermal gradient uses inexpensive materials so that multiple tests can be performed in parallel in a short period of time.

Animals↗

Internal limiting membrane removal in the management of full-thickness macular holes.

PURPOSE: To determine the effectiveness of removal of the internal limiting membrane in the treatment of full-thickness macular holes. METHODS: Data were reviewed from a prospective study on 47 consecutive eyes with full-thickness macular holes undergoing vitrectomy, internal limiting membrane maculorhexis, and fluid-gas exchange. No eye underwent repeat macular hole surgery. A meta-analysis was performed to compare the outcomes of different surgical techniques in the treatment of full-thickness macular holes. RESULTS: The outcome measures were disappearance of the submacular fluid and the change in best-corrected visual acuity. The surgery was anatomically successful in 44 of the 46 eyes (96%) and 39 of the eyes (85%) showed an improvement of at least two Snellen lines. Best-corrected final vision was 20/40 in 18 (39%) eyes. No permanent complications specifically caused by the removal of the macular internal limiting membrane were detected; the minor hemorrhages and retinal edema seen in most eyes resolved spontaneously. Retinal detachment developed and was successfully treated in three eyes (7%). A meta-analysis on 1,654 eyes from published reports showed that internal limiting membrane maculorhexis appears to significantly (P <.0001) increase the anatomical and functional success rates in macular hole surgery. CONCLUSIONS: Internal limiting membrane removal is an important development in the evolving field of macular hole surgery. A randomized, prospective, multicenter clinical trial should be performed to determine which surgical technique is the most beneficial in patients with full-thickness macular holes.

Adolescent↗

A continuing concern: HIV and hepatitis testing and prevalence among drug users in substitution programmes in Zurich, Switzerland.

Phase I of the Zurich Prometheus Study is a cross-sectional study focusing on an up-to-date serology for HIV and hepatitis B/C and associated risk factors for all clients in four participating clinics offering opiate substitution in Zurich, Switzerland. The mean age of the 603 respondents is 30.7 years (SD = 6.2) and 38% of them are women. Seventy-five per cent of the respondents have a history of injecting drug use (IDU), and over half have injected within the past six months. Laboratory-confirmed seroprevalence for HBV (50%) and HCV (57%) is twice that of HIV (24%). There is an 80% risk reduction for all three viral infections among those starting IDU after 1991--when harm reduction efforts were in full swing--compared to those who began before 1988--before clean needles were widely available. These findings suggest a strongly protective effect of harm reduction measures. But while a stabilization in HIV prevalence at 15% can be seen among drug users who started injecting after 1991, prevalence rates for HBV and HCV still remain several times higher. The prevalence data in this study support data showing continued high incidence rates for HBV and HCV, even among new injectors in the harm reduction era.

Adult↗

Pmg-1 and pmg-2 constitute a novel family of KAP genes differentially expressed during skin and mammary gland development.

The epidermis, by invagination of the undifferentiated ectodermal cells, gives rise to several distinct structures including hair, sebaceous, eccrine sweat and mammary glands. We have recently isolated a novel gene, pmg-1, expressed in the pubertal mouse mammary gland. While investigating its genomic structure, we identified a related gene in close proximity, which we have termed pmg-2. pmg-1 and pmg-2 are intron-less, are transcribed in opposite directions and are separated by a potential promoter region of 2.8 kb containing putative binding motifs for the developmental transcription factors Lef-1, Sox5 and D-STAT. pmg-1 and pmg-2 encode small proteins rich in G, S, F, Y and Q and contain characteristic repeats reminiscent of the keratin-associated proteins (KAPs). Both genes are expressed in growing hair follicles in skin as well as in sebaceous and eccrine sweat glands. Interestingly, expression is also detected in the mammary epithelium where it is limited to the onset of the pubertal growth phase and is independent of ovarian hormones. Their broad, developmentally controlled expression pattern, together with their unique amino acid composition, demonstrate that pmg-1 and pmg-2 constitute a novel KAP gene family participating in the differentiation of all epithelial cells forming the epidermal appendages.

Amino Acid Sequence↗

Quantitative determination and structure elucidation of type A- and B-trichothecenes by HPLC/ion trap multiple mass spectrometry.

A method is presented for the quantification and structure confirmation of trichothecenes in wheat by high-performance liquid chromatography combined with multiple mass spectrometry (MS(n)()). Nine type A- and B-trichothecenes were determined (nivalenol, deoxynivalenol, fusarenon-X, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, neosolaniol, diacetoxyscirpenol, HT-2 toxin, and T-2 toxin). Extraction was carried out with acetonitrile/water. The extract was purified on a MycoSep column. Quantification was based on an internal standard and atmospheric pressure chemical ionization in the positive ion mode. Recoveries from spiked wheat were in the range of 80-106% at levels of 500 ppb. The limits of quantification for the whole method were between 10 and 100 ppb. Ion adduct formation with ammonium and acetate ions and MS(n) experiments provided information about substitution and fragmentation behavior of the mycotoxins. A scheme has been established for the partial structure elucidation of type A- and B-trichothecenes in fungal cultures.

Animal Feed↗

The continuous-injection technique to reduce complications during retrobulbar anesthesia.

Retrobulbar as well as peribulbar anesthesia remain relatively risky procedures; retrobulbar hemorrhage and especially globe penetration or perforation can have blinding consequences. Our continuous-injection-technique greatly reduces these risks whether used for retrobulbar or peribulbar anesthesia. If the ophthalmologist starts injecting the agent while advancing the needle, the fluid pushes tissues away, possibly preventing a hemorrhage. Since resistance against the plunger is instantaneously experienced if the needle impacts the sclera, the ophthalmologist is adequately warned before actual perforation of the sclera occurs.

Anesthesia, Local↗

[Epidemiology of severe eye injuries. United States Eye Injury Registry (USEIR) and Hungarian Eye Injury Registry (HEIR)].

BACKGROUND: Both in industrialized and in developing nations, the devastating impact of ocular trauma on society is increasingly recognized. Lacking standardized surveillance systems, however, comparable epidemiological information has not been available previously. METHODS: For several years, the United States Eye Injury Registry (USEIR) and the Hungarian Eye Injury Registry (HEIR) have been collecting data on all types of serious ocular trauma, based on identical operating criteria and using standardized reporting forms. We performed a retrospective analysis comparing the two datasets, containing over 8,400 injuries from the U.S. and over 1,200 injuries from Hungary. RESULTS: Sixty percent of patients in the U.S. and 52% of patients in Hungary were less than 30 years of age, with an at least 80% male preponderance in both registries. The home was the most frequent place of injury in both countries (USEIR: 41%, HEIR: 35%); industrial premises represented no more than 14%. Guns were responsible for 12% of cases in the USEIR (HEIR, 1%). Champagne corks were identified as a unique and relatively common source of eye injury in Hungary (1.4%, as opposed to 0.07% in the U.S.). In the USEIR, 16% of injuries were caused by assault (HEIR, 24%; chi-square value = 36.7, p < 0.0000001). The enucleation rate was 12% in the U.S. and 1% in Hungary. CONCLUSIONS: The different findings in the two countries identify certain areas for the implementation of preventive measures (supplying champagne bottles with warning labels and a coordinated fight against violence in Hungary, stricter fireworks legislation in the U.S., public awareness for home injuries in both countries, etc.). Based on the encouraging results from this study, we plan to continue our efforts using modified reporting forms and an upgraded software. We invite additional countries to adopt the USEIR model.

Adolescent↗