PubMed Health⌕ Search

Biomedical subjects

J Daniel

Publications and source records attributed to J Daniel.

At least 37 records · Page 2Linked to original sources
PubMed1999

Perforating keratoplasty with an intracorneal ring.

PURPOSE: We evaluated the clinical feasibility of an intracorneal ring for penetrating keratoplasty (PKP) designed to decrease postoperative corneal astigmatism. MATERIAL AND METHODS: A steel alloy ring was used for 8-mm PKP. The prospective study was comprised of 15 consecutive patients who underwent PKP for different corneal pathologies. The mean age was 52 years (range, 20-74 years). The Guided Trephine System was used in all cases for the preparation of the donor button and the recipient bed to ensure identical dimensions. The donor button with the surrounding ring in place was sutured in place with a 10-0 nylon double-running suture. RESULTS: Except for one patient who had an allergic reaction to alloy components, no significant complications were observed. Mean reepithelialization occurred within an average of 4 days (range, 3-5 days). In 80% of the cases, stromal graft edema and Descemet's folds disappeared at 14 days after surgery. Average removal time of the intracorneal ring was 6 months (range, 3-9 months). Mean corneal astigmatism was 2.71 (standard deviation [SD], 1.37) diopters (D) before surgery compared to 2.10 (SD, 1.09) D at 1 month, 2.07 (SD, 1.26) D at 3 months, 2.29 (SD, 0.86) D at 6 months, and 2.94 (SD, 1.05) D at 12 months. In four eyes (27%), ruptures of one of the double-running antitorque sutures required resuturing. CONCLUSION: The intracorneal ring prevented the donor button from distortions related to peripheral changes or suture traction. A sutured intracorneal ring appears to be a safe and effective aid in keratoplasties. Further evaluation in a multicenter study with larger patient numbers and indication-specific longer follow-ups is under way.

Adult↗
PubMed1998

[The selective detection of glucose intolerance and diabetes in primary care. The ITG-Reus (Tarragona) Study. The Glucose Intolerance Research Group].

OBJECTIVE: To investigate the number of people with intolerance to glucose (ITG) and undiagnosed diabetes (DM) among primary care users at risk. DESIGN: Prospective, selective urban polling of a representative sample of those attended in the city of Reus (88,000 inhabitants). SETTING: Two base health areas (10 Primary Care teams) with an approximate overall reference population of 45,000 inhabitants. PATIENTS AND OTHER PARTICIPANTS: Clinical and examination data were recorded with a pre-designed questionnaire. Diagnoses were established by means of base glycaemia (mmol.l-1 or a 75 g glucose oral overload (0 and 120 minutes) for users over 40 with some Diabetes risk factor. Further tests were HbA1C (%), base peptide-C (nmol.l-1, total cholesterol, HDL cholesterol, triglycerides (mmol.l-1 and 24-hour microalbuminuria (mg). MEASUREMENTS AND MAIN RESULTS: After a year included in the survey, the data of 345 people were evaluated: 151 men, 58 years old (95% CI, 57-60) and BMI of 30.8 (30.3-31.4), with 197 diagnoses (57.1%) of normal tolerance to glucose (52-62%). 82 (23.8%) of ITG (20-28%) and 66 (19.1%) of undiagnosed DM (15-23%). Significant differences between the three were detected in age (56/61.5/61.7 years, p < 0.001), proportion of men (38/50/53%, p < 0.05), diagnosis of hypertension (40.6/59.8/53%, p < 0.01), previous anomaly in tolerance 28.4/45.1/51.5%; p < 0.001), HbA1C (4.6/4.9/5.4; p < 0.001), systolic pressure (140.5/143.6/151 mmHg, p < 0.007). Triglycerides (1.4/1.6/2.1, p < 0.001) and microalbuminuria (16/29/51, p < 0.001). Base peptide-C (3.5/3.8/3.8) showed no statistical differences. CONCLUSIONS: Selective detection in primary care amply exceeds opportunist detection in identifying patients with ITG who might be susceptible to preventive measures. In function of the intolerance level, from normality through to DM, statistical differences were found in HbA1C, systolic pressure, Triglyceridaemia and urinary excretion of albumin. These were not extendable to the rest of the lipid profile or to endogenous insulinaemia.

Adult↗
PubMed1998

Contrast sensitivity and glare disability after radial keratotomy and photorefractive keratectomy.

OBJECTIVES: To study the effects of radial keratotomy (RK) and photorefractive keratectomy (PRK) on contrast sensitivity and glare disability using 4 different devices, and to correlate subjective complaints with obj ective scores of visual performance. METHODS: Preoperative contrast sensitivity for 30 eyes undergoing RK and 30 eyes undergoing PRK was compared with contrast sensitivity at 1, 3, and 6 months postoperatively using the CSV 1000, MCT (Multivision Contrast Tester) 8000, and Pelli-Robson chart. The BAT (Brightness Acuity Tester) and MCT 8000 were used to test for daytime and nighttime glare disability, respectively. At 3 and 6 months postoperatively, a questionnaire was administered to assess visual performance subjectively. RESULTS: Contrast sensitivity decreased after RK and PRK up to the sixth postoperative month, while glare disability was significantly increased at 1 month after PRK as determined by the MCT 8000 and the BAT, and at the third and sixth months after RK using the MCT 8000. Compared with RK, PRK significantly decreased contrast sensitivity as measured with the MCT 8000 at all spatial frequencies 1 month postoperatively. No significant difference in visual performance between patients undergoing RK and PRK was observed with the CSV 1000, the Pelli-Robson chart, or the BAT up to 6 months postoperatively. No consistent difference was found between glare disability scores of patients undergoing RK and PRK when measured with the MCT 8000. Subjective reports of problems with night driving and blurring correlated only with glare disability scores of the MCT 8000 3 months after RK. CONCLUSIONS: Both RK and PRK reduce contrast sensitivity and cause glare disability; however, the relative effect is highly dependent on the time postoperative testing is performed and the instrument used for testing. Contrast sensitivity and glare disability, as measured by the instruments used in this study, do not accurately reflect patients' subjective assessment of visual performance in daily life.

Adult↗
PubMed1998

[Depth of lamellar keratoplasty with the guided trephine system for transplantation of full-thickness donor sections].

BACKGROUND: Despite the fact that deep lamellar keratoplasty (DLKP) is less invasive than to penetrating keratoplasty (PKP), this procedure is rarely performed. We therefore investigated whether or not the DLKP technique we employed can achieve stable improvement of visual acuity. MATERIALS AND METHODS: Thirty-three eyes underwent TLKP for treatment of superficial corneal pathology. The donor tissue transplanted was suitable for PKP. The donor lenticule was obtained on the artificial chamber of the guided trephine system (GTS). The recipient cornea was trephined with the same trephine to a depth of 680 microns. Manual dissection was performed with a bevel-up blade. The donor lenticule with the endothelium peeled off was then sutured in with a 10 x 0 nylon double-running antitorque suture. Cortisone-antibiotic eye drops were administered postoperatively. RESULTS: Throughout the series no complications occurred. The mean best corrected visual acuity (BSCVA) over glasses was 0.29 (+/- 0.21) preoperatively, 0.1 (+/- 0.11) at 1 week, 0.33 (+/- 0.14) at 1 month, 0.5 (+/- 0.13) at 6 months, 0.61 (+/- 0.16) at 1 year and 0.63 (+/- 0.15) at 2 years. Clinically, we observed two subpopulations. In the first group of 87% of the cases, mean BSCVA was 0.67 (+/- 0.07) at 6 months. The remaining cases (BSCVA < or = 0.25 at 6 months) achieved a mean BSCVA of only 0.2 (+/- 0.04) at 1 year. Mean corneal astigmatism measured 2.93 D (+/- 1.62) preoperatively, 2.69 D (+/- 1.18) at 1 month, 2.09 D (+/- 1.07) at 1 year, and 2.22 D (+/- 1.11) at 2 years. We did not observe any graft rejection. CONCLUSION: The technique reported for DLKP provides excellent matching of donor lenticule and recipient bed. Separation of donor and recipient stroma prevents interface healing. DLKP appears to be a safe procedure for the surgical treatment of superficial corneal pathology and may offer a clinically applicable alternative to PKP.

Adolescent↗
PubMed1998

Teaching of pathology in United States medical schools, 1996/1997 survey.

A variety of pressures to change curriculum have resulted in revision of pathology teaching in most medical schools in the United States. Responses obtained from 71% of schools on a recent survey of pathology teaching indicate the following: There are wide variations in the extent of use of various teaching modalities with resulting emergence of different teaching formats which can be categorized as "traditional," "enhanced traditional," predominantly "problem based" or "case oriented," entirely "problem based," or some form of "hybrid" of traditional and problem based. The traditional lecture and laboratory continue to be the primary modes of teaching in the vast majority (74%) of schools, however, 53% also use other approaches, eg, small group discussion, case studies, or conferences to enhance instruction. The lecture remains an important component of instruction in all major models. The form and extent of the laboratory use varies remarkably from minimal to large number of hours of instruction. The laboratory material is incorporated into small group discussion or conferences in many schools. The use of small group discussions (presently, by 79% of schools) has increased since the last survey conducted in 1986. The mean curricular time (presently 188 hours) has dropped, however, it is not easy to quantify pathology teaching in many schools with increasing integration. Instruction is entirely integrated, multidisciplinary in 28% of schools. Computer-aided instruction is used in some form to varying extents in 66% of schools, with the majority using it as a supplementary tool. There are persistent concerns about faculty time, and high student-faculty ratio.

Autopsy↗
PubMed1998

Blunt, bent needle for continuous curvilinear capsulorhexis.

We describe an anterior continuous curvilinear capsulorhexis (CCC) technique that uses a dull needle. The needle's blunt tip prevents inadvertent tearing of the anterior capsule, and its rough surface allows the surgeon to transmit a power vector of different amplitude and direction to the edge of the capsulorhexis to continue the tear as desired. For biomechanical reasons, we prefer an arcade-shaped CCC because this configuration provides a greater circumference than a circular CCC. The blunt needle allows one to perform a single-step capsulorhexis in a safe and controlled manner and reduces surgical time. Even in cases of white and liquified cortex, the dull needle has proved a useful, safe tool.

Capsulorhexis↗
PubMed1998

Live-epikeratophakia for keratoconus.

PURPOSE: To assess the clinical feasibility of refractive live-epikeratophakia (L-EPI) for early keratoconus to cap, rather than reverse, the ectatic cornea. SETTING: Eye Department, Martin-Luther-Hospital, Bochum, Germany. METHODS: Twenty-seven consecutive cases with keratoconus stage I-II had L-EPI. Lenticules were obtained from eye-bank eyes. The lenticules were cut on the artificial anterior chamber bench of the Barraquer-Krumeich-Swinger set. Optical power was generated over refractive dies to achieve postoperative emmetropia. The lenticule was sutured into a peripherally undermined 7.0 mm trephination with a double-running torque suture. RESULTS: Re-epithelialization was complete within 4 to 6 days. In all but three cases that had corneal ulcers and experienced partial melting of tissue following severe neurodermatitis, all lenticules remained stable during the 10 year follow-up. The 1 month spherical equivalent remained almost stable over the entire follow-up. There was no sign of progression of keratoconus as induced myopia or astigmatism indicated by keratometry readings. Mean best spectacle-corrected visual acuity (BSCVA) was 0.45 (n = 27) preoperatively and 0.19 (n = 25) at 1 week, 0.39 (n = 26) at 1 month, 0.53 (n = 20) at 6 months, 0.58 (n = 13) at 1 year, and 0.64 (n = 8) at 2 years. Preoperative BCVA was achieved or improved in 13 eyes at 1 month. Postoperative astigmatism was < or = 3.25 diopters. Neither rejection nor lenticule opacification was observed. CONCLUSIONS: Live-epikeratophakia is a safe and minimally invasive extraocular procedure suitable for keratoconus stage I-II. Progression of keratoconus may be arrested. If unsuccessful, the procedure is complementable and there is no interference with a later penetrating keratoplasty.

Cornea↗
PubMed1998

Minimally invasive cardiac surgery: surgical techniques and nursing considerations.

Coronary artery bypass grafting is a well-established procedure. Less invasive procedures have been developed to provide bypass grafting without median sternotomy, cardiopulmonary bypass, or cross clamping. Using a small anterior thoracic incision, and occasionally with the aid of the thoracoscope, the minimally invasive direct coronary artery bypass graft (MIDCAB) procedure was developed. The MIDCAB procedure results in a decreased length of hospital stay, fewer postoperative complications, and a more rapid recovery for the patient. The MIDCAB, however, has other ramifications, including changes in staffing requirements, bed allocations, and staff training. Advantages and limitations are discussed.

Coronary Artery Bypass↗
PubMed1997

[Live epikeratophakia and deep lamellar keratoplasty for I-III stage-specific surgical treatment of keratoconus].

BACKGROUND: Perforating keratoplasty (PKP) for the treatment of keratoconus is a temporary procedure that sacrifices the healthy recipient endothelium. As an alternative to PKP we perform live-epikeratophakia (L-EPI) in keratoconus I-II and deep lamellar keratoplasty (DLKP) in keratoconus II-III. PATIENTS AND METHODS: 20 patients with keratoconus were operated on either with L-EPI for keratoconus I-II (n = 10) or DLKP for keratoconus II-III (n = 10) respectively. In all cases, corneal tissue eligible for corneal transplantation was used. L-EPI: The corneal lenticule was prepared by means of the Barraquer-Krumeich-Swinger (BKS) set. The recipient cornea was trephined to a depth of 0.3 mm with the Guided-Trephine-System (GTS). The incision was extended manually (inner diameter 7.0 mm, outer diameter 9.0 mm). No keratectomy was performed. The lenticule was fixed with a 10 x 0 nylon double-running anti-torque suture (DRA). DLKP: The recipient cornea was trephined with the 8.0 mm GTS to a depth of 0.68 mm. A lamellar removal of the upper layers was performed by hand. After mechanical removal of the graft endothelium, the remaining full thickness donor cornea was sutured into the bed with a 10 x 0 nylon DRA suture. RESULTS: L-EPI: Within this series, there was no disturbance of the healing process. Spherical equivalent and corneal astigmatism remained stable from the first month on. Visual acuity of 20/40 or better was obtained in 40% of the cases at 1 month, 53% at 6 months, and 100% at 1 year and 2 years. We did not observe any late decline of VA. Two patients with kerato-conus borderline stage II did not reach useful VA due to insufficiently reduced pre-existing irregular corneal astigmatism. These patients successfully underwent DLKP at 8 and 10 months respectively. DLKP: Except for 1 case (neurodermatitis), all lenticules remained stable with respect to refraction and radii up to the longest follow-up of 2 years. Starting from the first month on, refraction was stable. Visual acuity of 20/40 or better was reached in 33% of the cases at 1 month, in 56% at 6 months, and in 89% at 1 and 2 years. We did not administer systemic cyclosporine-A in either group. In the lamellar techniques presented, we did not observe any graft rejection. According to corneal topography, corneal astigmatism, spherical equivalent, and keratometry we did not observe any late re-onset of a progression of the cone. CONCLUSION: In patients with keratoconus stage I to III, L-EPI or DLKP appeared to be very useful therapies. Both procedures seem to end progression of the disease and allow to preserve the healthy recipient endothelium. If unsuccessful, either procedure may be repeated. Neither procedure precludes possibly later needed PKP.

Astigmatism↗
PubMed1996

Measuring the toxic effects of high gene dosage on yeast cells.

A novel method, which is rapid, reliable and quantitative, is presented for measuring the toxic effects on yeast cells of high dosage of any given gene. It is based on the possibility of monitoring the presence in cells of a plasmid carrying the ADE2 gene from Saccharomyces cerevisiae by direct observation of colonies, the construction of this particular plasmid being easily made by marked homologous recombination in yeast. Four yeast regulatory genes tested were found to result in various degrees of toxicity at high dosage. Possible implications of the measurement of gene toxicity for eukaryotic cell regulatory mechanisms and for the use of novel general approaches to gene selection, such as the gene-gene interference method, are discussed.

Carboxy-Lyases↗
PubMed1996

Detection of antagonistic cellular regulatory functions by the gene-gene interference method in yeast.

It was previously assumed that a new genetic method in yeast, termed gene-gene interference, leads to the selection of genes that antagonize, and/or are antagonized by, the particular reference gene used for their selection (Daniel 1993). In this paper two pieces of evidence are advanced in favour of this view. Firstly, the reconstitution of a system of known antagonistic genes was shown to be detectable by the gene-gene interference method. Secondly, since ART1, a new gene selected in reference to the protein kinase A gene, has been shown to contain in its deduced polypeptide a putative site for phosphorylation by protein kinase A, a mutagenesis study directed toward this putative site has been performed. Two phenotypes-in vivo filamenting activity and gene-gene interference relative to the protein kinase A gene-were tested with the various mutations thus obtained and found to be consistent with the hypothesis that, under physiological conditions, phosphorylation by protein kinase A exerts an inhibitory effect on Art1 activity. The relevance of these findings on the mechanisms and potential applications of the gene-gene interference phenomenon is discussed.

Amino Acid Sequence↗
PubMed1995

DNA insertion system for complex yeast shuttle vectors.

A DNA insertion system, termed marked homologous recombination, was devised for the construction of complex yeast shuttle plasmids. This system, which is efficient, rapid and easy to use, should contribute to our understanding of gene-gene interactions in yeast cells.

Cloning, Molecular↗
PubMed1994

The influence of the cutting procedure on the loss of corneal endothelial cells of the recipient eye in mechanically guided trephination.

BACKGROUND: Excessive damage to the endothelial monolayer during corneal trephination may contribute to transplant failure. For this reason, we performed several trephining experiments to determine the influence of various cutting conditions (sharpness, rotation rate, and cutting power) on the endothelial damage in the recipient bed. METHODS: A mechanically guided motor trephine (Mikro-Keratron) was used for cutting experiments in fresh, enucleated porcine eyes. Eight different, reproducible combinations of cutting conditions were applied, and ten epithelial, full-thickness trephinations were performed for each combination. The endothelial defect was measured with a light microscope (60 x). In addition, the bend radii of the porcine cornea were measured. RESULTS: The mechanically guided Mikro-Keratron used with a sharp blade, high rotation rate (840 rev/min), and moderate cutting power (49 mN) caused a 31-micron-wide band of damaged endothelium in the recipient bed. Decrease of the rotation rate to 30 rev/min resulted in an increase of the endothelial defect to 168%. A cutting power of 392 mN combined with a rotation rate of 840 rev/min increased the defect to 126%. The system allowed full-thickness 360 degrees trephination. The corneal bend radii in porcine eyes measured 8.28 mm horizontally and 8.20 mm vertically. CONCLUSION: Our preliminary results indicate that the mechanically guided motor trephine, used under optimal conditions, is a suitable cutting device and may improve the outcome of penetrating keratoplasty; however, further investigation of this new approach is necessary.

Animals↗
PubMed1994

Immunocytochemical and serological expression of CA 125: a clinicopathological study of 40 malignant ovarian epithelial tumours.

Elevated serum levels of the tumour-associated antigen CA 125 occur in more than 80% of cases of ovarian carcinoma. The antigen can be demonstrated in formalin-fixed tissue using the monoclonal antibody OC 125, which localizes it to the surface membrane or cytoplasm. This study was performed to determine the relationship between pre-operative serum levels of CA 125 and the subsequent immunocytochemical findings in the surgical specimen. Paraffin-wax embedded sections from 40 consecutive borderline and frankly malignant ovarian epithelial tumours were stained with OC 125. The pattern and distribution of immunostaining were investigated in relation to histological appearances. Serous tumours showed a 100% correlation between immunocytochemical findings and elevated serum levels of CA 125. Amongst the other histological types, correlation was less good; mucinous tumours and undifferentiated carcinomas showed a poor correlation. Immunostaining within tumours was heterogeneous and only loosely related to morphological appearances. Our finding suggests that, with the exception of serous tumours, immunolocalization of CA 125 is insufficiently sensitive to provide reliable clinical guidance to the likely value of serum CA 125 monitoring on follow-up.

Adult↗
PubMed1994

Identification of a new catenin: the tyrosine kinase substrate p120cas associates with E-cadherin complexes.

p120cas is a tyrosine kinase substrate implicated in ligand-induced receptor signaling through the epidermal growth factor, platelet-derived growth factor, and colony-stimulating factor receptors and in cell transformation by Src. Here we report that p120 associates with a complex containing E-cadherin, alpha-catenin, beta-catenin, and plakoglobin. Furthermore, p120 precisely colocalizes with E-cadherin and catenins in vivo in both normal and Src-transformed MDCK cells. Unlike beta-catenin and plakoglobin, p120 has at least four isoforms which are differentially expressed in a variety of cell types, suggesting novel means of modulating cadherin activities in cells. In Src-transformed MDCK cells, p120, beta-catenin, and plakoglobin were heavily phosphorylated on tyrosine, but the physical associations between these proteins were not disrupted. Association of p120 with the cadherin machinery indicates that both Src and receptor tyrosine kinases cross talk with proteins important for cadherin-mediated cell adhesion. These results also strongly suggest a role for p120 in cell adhesion.

3T3 Cells↗