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Biomedical subjects

N Frankel

Publications and source records attributed to N Frankel.

12 recordsLinked to original sources
PubMed2001

The TATA-less promoter of VP1, a plant gene controlling seed germination.

Vp1 is a seed-specific gene involved in the control of dormancy and germination. We here present the complete sequence of the sorghum vp1 promoter/enhancer region highlighting its main features, especially the lack of canonical TATA and CAAT boxes and the presence of elements responsive to abscisic acid and light. The region closest to the start of transcription is highly homologous to the partial proximal sequence reported for the maize vp1 promoter. This region is interrupted by a 57-nt stretch containing 14 CT microsatellite repeats. We observed a poor overall homology to the promoter from abi3 gene, the Arabidopsis counterpart bearing a similar coding sequence. However, there exists a high degree of homology (89%) between a TATA-rich 103-bp stretch of the sorghum vp1 promoter located about 700 nt upstream of the startpoint and miniature inverted transposable elements (MITEs) interspersed within the sorghum seed-specific kafirin cluster. This sorghum MITE-like element displays considerable homology (68%) to the TATA-less promoter from the sorghum NADP-malate dehydrogenase gene and lesser similarity to the Tourist, Pilgrim and Batuta MITEs previously identified within the promoter from the maize Abp1 (auxin-binding protein) gene.

Base Sequence↗
PubMed1998

Long-term strength of aesthetic restoratives.

Glass-ionomer cements have established an important role in clinical dentistry since their introduction over 20 years ago. More recently, in an attempt to enhance the strength of the material, resin additions have been made to conventional glass-ionomer cements. This study established the long term flexural strength of two hybrid glass-ionomer cements, by use of a bi-axial flexural strength test (Shell test), and compared the values with those obtained for a light curing composite resin and a conventional glass-ionomer cement. The results demonstrated that those materials with a high resin component relying on polymerization as the main method of setting had a greater initial flexural strength than those with little or no resin addition. Those materials where the glass-ionomer acid-base reaction provided a substantial contribution to the setting reaction showed an increase in strength as they matured, whereas a decline in strength with time was observed for those materials where the resin setting reaction predominated.

Acrylic Resins↗
PubMed1986

Utilization of lung scans by clinicians.

To determine the effect of clinical assessments and lung scan results on the management of patients, we studied 566 consecutive patients referred for lung scans because of suspected pulmonary embolism. Prior to the lung scan, the clinician was asked to estimate the probability of pulmonary embolus. Two or three days later the physician was contacted to determine how the patient was managed. The results of the lung scan strongly influenced patient management. Patients with high probability lung scans were treated for pulmonary embolism regardless of the clinical pretest estimate. Low and intermediate probability lung scans resulted in most patients not being treated for pulmonary embolism and not referred for pulmonary angiography. Only 55 of the 566 patients were referred for pulmonary angiography, and approximately one-half of these patients had lung scans with an intermediate probability for pulmonary embolism.

Anticoagulants↗
PubMed1984

Platelet uptake of the pheochromocytoma-scanning agent 131I-meta-iodobenzylguanadine.

The pheochromocytoma-scanning agent 131I-meta-iodobenzylguanadine (131I-MIBG) was concentrated in the platelets of ten subjects undergoing scans for suspected pheochromocytomas. In vitro studies also demonstrated that 131I-MIBG was concentrated in platelets. In contrast to serotonin, which had maximum in vitro platelet uptake of one hour, the peak in vitro platelet uptake of 131I-MIBG did not occur until six hours. In vitro platelet 131I-MIBG uptake was decreased by 79% to 98% following the neuronal-uptake-blocking agent imipramine. These studies suggest that pheochromocytomas take up 131I-MIBG by a neuronal-pump mechanism. Further studies to determine if 131I-MIBG is taken up by other tumors with a neuronal-pump mechanism, such as carcinoid tumors, will be valuable.

3-Iodobenzylguanidine↗
PubMed1978

Circulating anticoagulant associated with chronic active hepatitis.

Chronic active hepatitis is frequently associated with a variety of serologic abnormalities. A patient with chronic active hepatitis and a circulating anticoagulant to factors XI and XII is described. Circulating anticoagulants should be suspected in patients with chronic active hepatitis and a prolonged partial thromboplastin time. This risk of liver biopsy in these patients is unknown, but this possible hazard should be considered in all patients with chronic active hepatitis.

Adult↗
PubMedDate not supplied

Surface roughness and flexural strength of self-glazed, polished, and reglazed In-Ceram/Vitadur Alpha porcelain laminates.

PURPOSE: Because of existing controversy, the present study investigated 3 methods for reducing surface roughness and improving the strength of porcelain restorations. MATERIALS AND METHODS: Ninety laminated In-Ceram/Vitadur Alpha self-glazed porcelain disks were fabricated and randomly divided into 3 groups (n = 30 each). Group 1 consisted of 30 of the original disks. The remaining 60 disks were then polished by 6 operators according to the recommendations of the American Academy of Esthetic Dentistry; group 2 consisted of 30 of these polished disks. The remaining 30 polished disks were reglazed (group 3). Average roughness values (Ra) of the veneers were measured by a profilometer. In each group, 20 disks were subjected to a flexure test, with 10 of the In-Ceram cores and 10 of the Vitadur Alpha veneers placed in tension. RESULTS: The Ra values were 0.5 +/- 0.1 micron, 0.7 +/- 0.3 micron, and 0.4 +/- 0.1 micron for groups 1 to 3, respectively. Following one-way analysis of variance (ANOVA), Bonferroni's multiple comparison tests found that groups 1 and 3 were significantly smoother than the polished group (P < 0.001). Reglazed disks were also significantly smoother than the original self-glazed disks (P < 0.01). With the veneers in tension, the flexural strengths were 151 +/- 22 MPa, 118 +/- 22 MPa, and 172 +/- 27 MPa for group 1 to 3, respectively. Following one-way ANOVA, Bonferroni's multiple comparison tests found that groups 1 and 3 were similar and were significantly stronger than the polished samples (P < 0.05 and P < 0.001). CONCLUSION: Reglazing polished porcelain surfaces significantly improved the surface texture and flexural strength of the materials tested.

Algorithms↗
PubMedDate not supplied

First metatarsophalangeal joint arthrodesis with the Truncated Cone Reamer System.

This manuscript introduces to the podiatric community the Truncated Cone Reamer (TCR) System for precise fashioning of the first metatarsal and proximal phalanx for a first metatarsophalangeal joint peg-in-hole type arthrodesis. As the name of the system suggests, the device reams out a truncated male cone at the metatarsal head and a corresponding female cone at the phalangeal base in the desired position. There is congruous cancellous bony contact at all apposing surfaces of the truncated cone for bony consolidation. The peg-in-hole intrinsically confers the arthrodesis stability. The authors present a step-by-step use of the TCR system, and a 1 year follow-up case study in which the TCR system was used as a template.

Arthrodesis↗