PubMed Health⌕ Search

Biomedical subjects

Y Meller

Publications and source records attributed to Y Meller.

At least 19 recordsLinked to original sources
PubMed1995

A GCC element and a G-box motif participate in ethylene-induced expression of the PRB-1b gene.

The PRB-1b gene codes for a basic-type pathogenesis-related protein and is activated at the transcriptional level by the plant hormone ethylene. To identify cis-acting DNA elements essential for ethylene induction, deleted and mutant forms of the PRB-1b promoter, fused to the beta-glucuronidase (GUS) coding region, were introduced in transgenic tobacco plants. A 73 bp fragment (X1 region) of the PRB-1b promoter, located between positions -213 and -141, was sufficient to confer ethylene responsiveness to the reporter gene. The X1 region contains a TAAGAGCCGCC motif (GCC-box) well conserved in several ethylene-inducible genes. A substitution mutation in this sequence, in the context of a 213 bp PRB-1b promoter, completely abolished ethylene induction in transgenic tobacco, defining this conserved motif as part of a cis-acting element responsive to ethylene. Three other mutations in the X1 region caused a pronounced decrease in the PRB-1b promoter activity in transgenic plants, but did not affect ethylene inducibility. One of them, localized in a G-box like motif (CACGTG), disrupted the binding site for a nuclear factor, as observed in gel-shift analysis. Interestingly, the mobility of the complex formed on the G-box element was dependent on its phosphorylation state. These results suggest that a cis-acting element involved in the perception of the ethylene signal resides in a GCC motif and acts in concert with additional elements in the regulation of ethylene-induced PRB-1b expression.

Base Sequence↗
PubMed1994

Gigantic lipomas.

Two cases of unusually giant lipomas--weighting 5070 and 4000 gm--are described. Tumors were present for 5 years on the back in a 55-year-old man and for 20 years at the anterior compartment of the thigh in an 80-year-old woman. Difficulty in fitting clothes was the first patient's sole complaint, and social pressure was actually the reason that brought him to his doctor. The second patient suffered from pain during the last 2 years. The weight of the bigger tumor was calculated preoperatively from the uptake of technetium-99m DTPA during scanning. Dissection of the tumors from the surrounding tissues was extremely easy in both cases. At 5 years and 1 year following surgery, there is no evidence of recurrence.

Aged↗
PubMed1993

DNA-protein interactions on a cis-DNA element essential for ethylene regulation.

The PRB-1b gene encodes for a basic-type component of the pathogenesis-related PR-1 protein family. In leaves of tobacco plants, PRB-1b mRNA accumulation is rapidly induced by the application of exogenous ethylene. Promoter deletion analysis was performed in transgenic tobacco plants to delineate cis-acting elements necessary for ethylene responsiveness of the PRB-1b gene. The promoter sequence from position -213 was sufficient to enhance a 20 fold increase of beta-glucuronidase reporter gene expression in transgenic tobacco leaves exposed to 20 microliters/l of ethylene, however -141 bp were not. The functional study was correlated with in vitro analysis of the nuclear protein-DNA complexes formed on the promoter element identified as necessary for ethylene induction. Gel-shift analysis using restriction fragments spanning the sequence between position -237 and -143 revealed two distinct nuclear protein-DNA interactions. The protein-binding sequences were mapped to the contiguous regions G (-200 to -178) and Y (-179 to -154) by gel-shift analysis using oligonucleotides. Fractionation of crude nuclear extract by heparin-agarose chromatography resulted in the differential elution of the two binding activities. The DNA-nuclear protein interactions characterized in vitro can be part of the molecular events which mediate the transcriptional regulation of the PRB-1b gene by ethylene.

Base Sequence↗
PubMed1993

A basic-type PR-1 promoter directs ethylene responsiveness, vascular and abscission zone-specific expression.

Pathogenesis-related (PR) proteins form a heterogeneous group of host-encoded, low-molecular-mass proteins that are secreted through the exocytic pathway. They are synthesized by the plant in response to various stimuli, including pathogen attack or exposure to certain chemicals. The PRB-1b gene of Nicotiana tabacum codes for a basic-type PR-1 protein whose transcription is regulated by ethylene. A minimal ethylene-responsive promoter element was defined by deletion analysis in transgenic tobacco plants. Promoter sequences containing 213 bp or more were sufficient to enhance a 20-fold increase of beta-glucuronidase reporter gene expression in transgenic tobacco leaves exposed to 20 microliters l-1 of ethylene, while 67 bp were not sufficient to trigger ethylene responsiveness. All the constructs that retained ethylene inducibility exhibited phloem-specific activity, which was constitutive in petiole and pedicel abscission zones. This functional study was correlated to an in vitro screening of the major nuclear proteins' binding sites present on the promoter. Gel-shift analysis using nuclear extracts from ethylene-treated and non-treated plants revealed five sequence-specific protein-DNA complexes on promoter sequences spanning -863 to -142 bp. Constitutive expression of the basic-type PR-1 genes at the leaf and petiole or flower and pedicel interfaces may represent pre-emption of plant defenses against potential pathogens, suggesting a functional similarity to pathogen-induced expression in the leaf.

Base Sequence↗
PubMed1991

Continuous postoperative regional analgesia by nerve sheath block for amputation surgery--a pilot study.

A pilot study of continuous postoperative regional analgesia by nerve sheath block for lower limb amputation is presented. At the time of exposure of sciatic or posterior tibial nerve trunks during above- or below-knee amputations in 11 patients with ASA physical status III or IV, a catheter was introduced directly into the transected nerve sheath for continuous infusion of 0.25% bupivacaine at a rate of 10 mL/h for 72 h. Effective amputation stump analgesia was obtained, significantly reducing the need for on-demand narcotic analgesics during this time to a mean dose equivalent of 1.4 mg of morphine compared with a retrospective control group who received the equivalent of a mean dose of 18.4 mg of morphine (P less than 0.0001). No complications related to the technique were observed. A follow-up of the group receiving continuous postoperative regional analgesia for up to 12 mo showed a total absence of phantom pain despite the presence of preoperative limb pain.

Aged↗
PubMed1987

Bilateral hip resection for closure of trochanteric pressure sores: case report.

Bilateral resection of the proximal femur, an orthopaedic procedure advocated in selected cases of infected hip joints, can be useful in the treatment of extensive pressure sores in paraplegics. It is especially indicated in those cases where a total thigh flap is considered with the advantage of saving the limb, and by shortening the leg providing more skin and soft tissue for closure of the pressure sores.

Adolescent↗
PubMed1986

Seasonal variation in serum levels of vitamin D metabolites and parathormone in geriatric patients with fractures in Southern Israel.

In 41 geriatric patients with long bone fractures, a seasonal variation was observed in the serum levels of 25-hydroxyvitamin D (25-OH-D), 1,25-dihydroxyvitamin D [1,25(OH)2D], 24,25-dihydroxyvitamin D [24,25(OH)2D] and parathormone (PTH). The serum concentrations of vitamin D metabolites correlate positively, while that of PTH correlates negatively with day length and global solar radiation in southern Israel. Our data suggest that the higher serum levels of vitamin D metabolites during the summer suppress PTH secretion. During the winter, the reduction of serum levels of vitamin D metabolites due to decreased endogenous production was accompanied by an increase in serum PTH levels.

24,25-Dihydroxyvitamin D 3↗
PubMed1985

Parathormone, calcitonin, and vitamin D metabolites during normal fracture healing in geriatric patients.

In order to study the role of calcium-regulating hormones during callus formation in elderly patients, serum levels of parathormone (PTH), calcitonin (CT), 25-hydroxyvitamin D [25-OH-D], 1,25-dihydroxyvitamin D [1,25(OH)2D], 24,25-dihydroxyvitamin D [24,25(OH)2D], and calcium (Ca) were determined in 41 patients with fractures of long bones, primarily hip fractures. The parameters were measured on admission and after eight weeks. There were almost no changes in hormone serum levels during bone repair, except for a decrease in serum levels of 1,25(OH)2D from 25.3 +/- 2.3 pg/ml on admission to 21.0 +/- 2.0 pg/ml eight weeks later (p less than .001). Patients with fractures compared to normal elderly humans have lower serum levels of PTH (0.99 +/- 0.06 ng/ml versus 1.88 +/- 0.34 ng/ml; p less than .001), 25-OH-D (10.7 +/- 1.0 ng/ml versus 17.1 +/- 1.8 ng/ml; p less than .001), and Ca (9.1 +/- 0.1 mg% versus 9.7 +/- 0.1 mg%; p less than .001) and higher serum levels of 1,25(OH)2D (25.3 +/- 2.3 pg/ml versus 17.1 +/- 2.3 pg/ml; p less than .001). Female patients have lower serum levels of 24,25(OH)2D compared to males (1.65 +/- 0.15 ng/ml versus 2.06 +/- 0.29 ng/ml; p less than .05). A similar trend was noted in serum CT levels during callus formation (0.12 +/- 0.02 ng/ml versus 0.16 +/- 0.02 ng/ml; p less than .05). Patients with subcapital fractures of the femur have significantly lower serum levels of all vitamin D metabolites on admission, compared with patients suffering from extracapsular fractures.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1984

Chronic multifocal symmetrical osteomyelitis. Report of two cases in Bedouin infants.

Chronic multifocal symmetrical osteomyelitis is a rare condition characterized clinically and radiologically by multiple symmetrical bone lesions, a benign course, and a good prognosis. To our knowledge, only 25 cases have been reported in the literature; all of them occurred in patients of European ancestry. We describe two bedouin children, aged 20 and 21 months, who suffered from this disease. Although they complained of one painful joint, multiple osteolytic lesions were found in the long bones. At follow-up six months later, the children were in perfect condition without radiologic sequelae.

Ankle Joint↗
PubMed1984

Hormonal control of fracture healing in a dog with chorea.

An experimental fracture in a dog with chorea was found to heal faster, and with a larger callus, than normal. Serum levels of parathormone (PTH), calcitonin (CT) and vitamin D metabolities were determined during callus formation. Serum concentrations of vitamin D metabolites were lower from the beginning while serum CT levels were higher compared to normal dogs. A massive increase in serum levels of 24,25-dihydroxyvitamin D was noted during the healing period. These results and observations suggest the existence of some disturbances in the secretion of hormones regulating calcium metabolism during bone repair where a nervous system lesion exists.

Animals↗
PubMed1984

Parathyroid hormone, calcitonin, and vitamin D metabolites during normal fracture healing in humans. A preliminary report.

The metabolism of calcium is regulated by hormones: parathyroid hormone, (PTH) calcitonin (CT), and vitamin D metabolites. To study the physiologic role of these hormones during the process of fracture healing in humans, the blood levels of PTH, CT, 25-(OH)-D3, 24,25-(OH)2-D3, and calcium were determined in 13 young patients with fractures of long bones. The parameters were measured first on admission and again after six to eight weeks. A group of healthy volunteers of similar age and sex served as control subjects. Plasma calcium level on the day of fracture was significantly reduced, 8.50 +/- 0.23 mg% (p less than 0.001). Serum CT level on the day of fracture was significantly increased, 0.18 +/- 0.02 ng/ml (p less than 0.05), and it continued to increase during the healing period, up to 0.23 +/- 0.02 ng/ml (p less than 0.001) after six to eight weeks. A significant rise was noted in plasma level of 24,25-(OH)2-D3, from 2.02 +/- 0.42 ng/ml on the day of fracture to 2.84 +/- 0.41 ng/ml six weeks later (p less than 0.05). No significant changes were found in serum PTH and plasma 25-(OH)-D3 levels on the day of fracture or during the healing process. The results suggest a possible physiologic active role for CT and 24,25-(OH)2-D3 in fracture healing in humans.

Adult↗
PubMed1983

Primary liposarcoma of bone. Case report and review of the literature.

Although liposarcoma is a common tumor of the soft tissues of the body, it rarely occurs as a primary neoplasm of bone. An extensive review of the literature from 1930-1980 uncovered fewer than 35 cases. The authors discuss the diagnosis and treatment of a case of primary liposarcoma of bone in the right femur of a 34-year-old Bedouin man.

Adult↗
PubMed1982

Subcapital fracture of neck of femur with complete posterior dislocation of the hip.

A rare case of a posterior fracture-dislocation of the hip joint with an ipsilateral subcapital fracture in a young woman is presented. The isolated femoral head was displaced in the subcutaneous area in the buttock. A possible explanatory mechanism of dual injury is that the posterior fracture-dislocation occurred first and then a lateral blow to the buttock caused the subcapital fracture. The missing fragment of the femoral head, in two parts, was located and replaced with a prosthesis before the hip was reduced. An extensive search in the literature failed to reveal a similar case.

Accidents, Traffic↗
PubMed1982

Phalangeal microgeodic syndrome in childhood. A case report.

A rare case of avascular necrosis of bone of unknown etiology affecting several phalanges of one hand in a 12-year-old Israeli girl is presented. This entity has been described in the literature under the title of "Phalangeal microgeodic syndrome in childhood." Forty cases have been reported mostly from Japan. The clinical presentation is that of a sudden onset of chilblain-like appearance of the fingers. Characteristically, the disease occurs in the colder months of the year. The radiological picture is pathognomonic although an inexperienced observer might suspect an aggressive destructive lesion. The prognosis is excellent as the disease is a self-limited one and surgery is unnecessary.

Adolescent↗
PubMedDate not supplied

Mineral and endocrine metabolism during fracture healing in dogs.

The blood levels of parathormone (PTH), calcitonin (CT), vitamin D metabolites, calcium, phosphate, magnesium and alkaline phosphatase (AKP) were determined in 13 young dogs with experimental fractures of long bones. The parameters were measured before the fracture and during healing until the appearance of an early callus. Serum Ca levels were significantly reduced immediately after the fracture (10.95 +/- 0.30 mg/dl to 10.25 +/- 0.25 mg/dl; p less than 0.05). Significant rises in serum levels of PTH (0.99 +/- 0.10 ng/ml to 1.57 +/- 0.22 ng/ml; p less than 0.01); CT (0.14 +/- 0.01 ng/ml to 0.18 +/- 0.01 ng/ml; p less than 0.05); 24,25-dihydroxyvitamin D (13 +/- 2 ng/ml to 19 +/- 3 ng/ml; p less than 0.01) and AKP (153 +/- 24 U/l to 211 +/- 26 U/l; p less than 0.01) were noted during fracture repair. A reduction in serum levels of 25-hydroxyvitamin D (22 +/- 2 ng/ml to 15 +/- 1 ng/ml; p less than 0.001) was noted at the same time. The parameters returned or tended to return to normal levels during callus development. The data demonstrate the changes in levels of Ca-regulating hormones in response to bone injury. This suggests that CT and 24,25-dihydroxyvitamin D (24,25-(OH)2-D) can be associated with the process of callus formation.

Alkaline Phosphatase↗