Search PubMed⌕ Search

Biomedical subjects

D A Gilbert

Publications and source records attributed to D A Gilbert.

At least 55 records · Page 3Linked to original sources
PubMed1990

Application of DNA fingerprints for cell-line individualization.

DNA fingerprints of 46 human cell lines were derived using minisatellite probes for hypervariable genetic loci. The incidence of 121 HaeIII DNA fragments among 33 cell lines derived from unrelated individuals was used to estimate allelic and genotypic frequencies for each fragment and for composite individual DNA fingerprints. We present a quantitative estimate of the extent of genetic difference between individuals, an estimate based on the percentage of restriction fragments at which they differ. The average percent difference (APD) among pairwise combinations from the population of 33 unrelated cell lines was 76.9%, compared with the APD in band sharing among cell lines derived from the same individual (less than or equal to 1.2%). Included in this survey were nine additional cell lines previously implicated as HeLa cell derivatives, and these lines were clearly confirmed as such by DNA fingerprints (APD less than or equal to 0.6%). On the basis of fragment frequencies in the tested cell line population, a simple genetic model was developed to estimate the frequencies of each DNA fingerprint in the population. The median incidence was 2.9 X 10(-17), and the range was 2.4 X 10(-21) to 6.6 X 10(-15). This value approximates the probability that a second cell line selected at random from unrelated individuals will match a given DNA fingerprint. Related calculations address the chance that any two DNA fingerprints would be identical among a large group of cell lines. This estimate is still very slight; for example, the chance of two or more common DNA fingerprints among 1 million distinct individuals is less than .001. The procedure provides a straightforward, easily interpreted, and statistically robust method for identification and individualization of human cells.

Alleles↗
PubMed1989

Temporal changes in phosphoamino acid phosphatase activities in murine erythroleukaemic cells.

1. The activities of phosphotyrosine, phosphothreonine and phosphoserine phosphatases were measured at various time periods in Friend murine erythroleukaemic (MEL) cells. 2. Effects of DMSO (dimethyl sulphoxide) and HMBA (hexamethylene bisacetamide), inducers of differentiation, were examined. 3. The activities of all three enzymes showed cyclic variation when measured on a daily basis over a period of several days; this was also the case when phosphothreonine phosphatase was determined in cells treated with DMSO or HMBA and when phosphoserine phosphatase was assayed after stimulation of the cells with HMBA. 4. Evidence for rhythmic variation in phosphotyrosine phosphatase activities was also obtained when the activities were determined at hourly intervals both in control cells and those treated with HMBA. 5. The time-dependent changes observed could be significant in that control of dephosphorylation may possibly be achieved by altering the rhythms.

Animals↗
PubMed1989

Isolation and characterization of collagen in Peyronie's disease.

Peyronie's disease is characterized histologically by excessive collagen deposition in the lesion. We examined the collagen types in Peyronie's disease plaque tissues compared to unaffected tissues from the same patient, other control tissues, and Dupuytren's contracture. Gel electrophoresis of pepsin-solubilized collagen demonstrated the presence of type I collagen and an increased content of type III collagen in plaque tissue. Increased type III collagen was detected in apparently normal tissue adjacent to the plaque and in Dupuytren's lesion, confirming previous findings. Although the cause of excessive collagen accumulation of Peyronie's disease is unknown, the results suggest an imbalance in the regulation of extracellular matrix production leading to pathologic fibrosis.

Collagen↗
PubMed1989

The vascularized fascia of the scalp.

The fascial layers of the temporal and occipital regions of the scalp were examined in 11 fresh cadavers. In the temporal region, three independently vascularized layers were isolated, all of which could be elevated on a single superficial temporal artery, but separated to remain independently vascularized from specific branches of this parent trunk. In the occipital area, the occipital vessels could be dissected to yield a long pedicle for an independent, fascial territory that could be transposed locally or elevated as a free flap and that will, in all likelihood, carry vascularized occipital bone. Realized and as yet unrealized uses of these ultrathin vascularized tissues remain boundless. Three representative cases are presented.

Adult↗
PubMed1989

Management of amputation injuries of the male genitalia.

Modern tissue transfer techniques have drastically modified our approach to reconstructive surgery in general. Certainly, the management of traumatic genital amputation is no exception. Although the unique vascular properties of the penis have allowed for astonishingly good results in a number of cases of genital amputation injuries, it is certain that microreplantation procedures make for uniformly good results with a minimum of postoperative complications. After microreplantation, the patient is left with a penis that is cosmetically normal and functionally nearly normal or undetectably abnormal. Although microreplantation offers the best results, certainly in the case of penile amputation, if microreplantation technology is not available, the older corporal reattachment techniques should be offered.

Amputation, Traumatic↗
PubMed1988

Chromosomal mapping of lysosomal enzyme structural genes in the domestic cat.

A panel of 42 rodent x cat somatic cell hybrids has been used to assign seven structural genes for lysosomal enzymes to specific chromosomes in the domestic cat. The assignments include alpha-glucosidase (GANAB) to chromosome D1, alpha-galactosidase (GLA) to the X chromosome, beta-galactosidase 1 (GLB1) to chromosome B3, beta-glucuronidase (GUSB) to chromosome E3, alpha-mannosidase A (MANA) to chromosome B3, alpha-L-fucosidase (FUCA) to chromosome C1, and hexosaminidase A (HEXA) to chromosome B3. In all cases, the feline lysosomal enzyme genes were located in linkage groups which were syntenic with their homologous positions in the human gene map. These assignments expand the genetic map of the cat and reaffirm the extensive syntenic homology between the chromosome maps of man and cat.

Animals↗
PubMed1988

Phallic reinnervation via the pudendal nerve.

Total phallic reconstruction presents the genitourinary reconstructive surgeon with one of the most difficult surgical challenges. The development of microsurgical techniques and free tissue transfers have advanced phallic reconstruction by reducing the number of surgical procedures and by allowing more selectivity in choosing the best innervated donor tissue. During the last 5 years 16 patients underwent total phallic reconstruction using free tissue transfers from distant donor sites. The pudendal nerve was coapted routinely to the major sensory nerves of the donor free flap. The most accurate objective baseline parameters of penile sensibility are pressure and vibratory thresholds, and electrically evoked potentials. We examined 30 normal subjects and 7 patients at least 1 year postoperatively for penile (phallic) sensibility. A pressure aesthesiometer, a biothesiometer and electrodiagnostic studies were used for testing. The 7 postoperative patients (in all of whom the pudendal nerve was incorporated into the reconstruction) had an encouraging return of tactile and erogenous sensibility compared to normal subjects. This is a promising advance in phallic reconstruction.

Adolescent↗
PubMed1988

Laser welding in urethral surgery: improved results with a protein solder.

Reconstruction of the rat urethra using the CO2 laser and a protein solder has dramatically decreased the postoperative fistula rate and decreased surgical time over conventional microsurgical reconstruction. Using the rat as a model, a partial transection of the ventral urethra was repaired in one of three ways in 39 animals: conventional microsuture repair, laser assisted microsuture repair and laser assisted microsuture repair with a protein solder. The success rate in each group was 50%, 58% and 90% respectively. Therefore, the laser repair is an efficacious as conventional microsuture repair. More importantly, laser with solder is significantly better than either the conventional method or laser alone.

Albumins↗
PubMed1988

Male genital trauma.

We have attempted to discuss genital trauma in relatively broad terms. In most cases, patients present with relatively minimal trauma. However, because of the complexity of the structures involved, minimal trauma can lead to significant disability later on. The process of erection requires correct functioning of the arterial, neurologic, and venous systems coupled with intact erectile bodies. The penis is composed of structures that are compliant and distensible to the limits of their compliance. These structures therefore tumesce in equal proportion to each other, allowing for straight erection. Relatively minimal trauma can upset this balance of elasticity, leading to disabling chordee. Likewise, relatively minimal injuries to the vascular erectile structures can lead to significantly disabling spongiofibrosis. The urethra is a conduit of paramount importance. Whereas the development of stricture is generally related to the nature of the trauma, the extent of stricture and of attendant complications is clearly a function of the immediate management. Overzealous debridement can greatly complicate subsequent reconstruction. A delicate balance between aggressive initial management and maximal preservation of viable structures must be achieved.

Amputation, Traumatic↗
PubMed1988

Transsexual surgery in the genetic female.

The increasing acceptance of the transsexual patient by society as well as a willingness of insurance companies to compensate for associated surgical procedures will result in an increase in patients presenting for sex reassignment. Data from gender identity centers suggest that the multidisciplinary approach leads to the best therapeutic results. Significant advances in phalloplasty techniques are yielding genitalia with more normal function and appearance.

Breast↗
PubMed1987

Functional evaluation of pharyngoesophageal reconstructive techniques.

This work represents a 12-year experience from the Eastern Virginia Medical School, Norfolk, with 115 patients who had pharyngoesophageal resections for cancer treatment. Each patient received reconstruction by one of four major techniques: deltopectoral flaps (n = 43), pectoralis myocutaneous flaps (n = 36), gastric pull-ups (n = 19), and free jejunal autografts (n = 17). An analysis of the procedures with emphasis on the functional results indicates that each technique has advantages in specific circumstances. Guidelines for the application of these techniques are presented.

Adolescent↗
PubMed1987

Chromosome abnormalities in Peyronie's disease.

Peyronie's disease is a localized and progressive fibrosis of unknown etiology that affects the tunica albuginea of the penis. We examined cytogenetically cell cultures derived from plaque, adjacent tunica, dermis and lymphocytes in patients with Peyronie's disease, and compared the results to cell cultures established from the tunica albuginea of control patients. Chromosomal abnormalities were detected in 9 plaque-derived cell cultures from 7 of 12 Peyronie's disease patients (58 per cent). Cells cultured from adjacent tunica, dermis and lymphocytes from the same patients were karyotypically normal, as were cultures derived from control (chordee and penile scar) patients. Chromosomal aberrations consisted of 5 numerical changes and 4 structural rearrangements, and included chromosomal additions (trisomy 7 and trisomy 8), deletions (45X,-Y), reciprocal translocations and inversions or markers. In 2 instances cultures derived from plaque tissue contained 2 independent chromosomal abnormalities. The apparently random chromosomal changes associated with Peyronie's disease suggests that karyotypic instability may be a common feature of cells within the plaque. It presently is unclear whether this finding represents multiple pathways for the development of Peyronie's disease or secondary consequences of Peyronie's disease.

Aged↗
PubMed1987

New concepts in phallic reconstruction.

Over the past four years we have performed total phallic reconstructions in 12 patients. Six patients underwent reconstruction following trauma, 3 were female-to-male transsexuals, and 3 had micropenis deformities. These reconstructions were one-stage microsurgical tissue transfers that included urethral reconstruction and coaptation of erogenous nerves. The surgical indications, techniques, and results are discussed.

Adult↗
PubMed1987

Free jejunal transfer for the reconstruction of pharyngeal and cervical esophageal defects.

Free jejunal transfer is a useful alternative for the reconstruction of defects of the pharynx and cervical esophagus. We describe 17 patients who received free jejunal grafts between 1980 and 1984 at the Eastern Virginia Medical School. The rationale and indications for the procedure are discussed. We emphasize certain technical considerations and improvements.

Adult↗