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R C Smith

Publications and source records attributed to R C Smith.

At least 91 records · Page 5Linked to original sources
PubMed1998

Direct supervision: adding computer-assisted feedback and data capture to live supervision.

This is a critical review of live supervision with emphasis on technical innovations such as earphones or bug-in-the-ear, Teleprompters, and computers. A computer-assisted approach is described that overcomes many criticisms of live supervision. Direct supervision uses a computer monitor to unobtrusively provide information to the therapist about the supervisor's perceptions of the clients' and therapist's behavior, the expected therapeutic behaviors, and the therapist's "on target" behavior. Direct supervision has the advantage over other forms of supervision by providing an immediate, continuous, and permanent record for postsession supervision and for research into the supervisor-therapist-client process. The paper provides several suggestions for research.

Family Therapy↗
PubMed1998

Trends in per-patient gross income to dental practices from insured patients, 1980-1995.

The authors discuss changes that occurred in per-patient gross income to dental practices from insured patients between 1980 and 1995. The current young-adult cohort appears to provide lower per-patient practice incomes compared with earlier young-adult cohorts. These changes may be the result of differences in the need for restorative care among young adults who benefited from the childhood caries decline of the 1970s and 1980s. If this reduced use of restorative services pattern persists as this young-adult cohort and succeeding cohorts age, the effect on dental practices could be substantial.

Adolescent↗
PubMed1998

The value of unenhanced helical computerized tomography in the management of acute flank pain.

PURPOSE: We developed an algorithm using unenhanced computerized tomography (CT) for the management of acute flank pain and suspected ureteral obstruction. MATERIALS AND METHODS: During a 25-month interval 417 patients with acute flank pain underwent unenhanced helical CT. The final diagnosis was confirmed by additional imaging or clinical followup. For all patients who underwent additional imaging studies the official dictated radiology reports were used to determine whether the studies were recommended based on CT findings. Cases requiring intervention were evaluated to determine whether additional imaging was performed before the procedure. Medical records were reviewed and/or patients were interviewed to document the course of therapy and long-term outcome. RESULTS: Unenhanced helical CT diagnosed ureteral stone disease with 95% sensitivity, 98% specificity and 97% accuracy. Of the 38 patients requiring intervention, including nephrostomy catheters in 18, lithotripsy in 3 and ureteroscopic stone extraction in 7, additional imaging (excretory urography) was performed in only 1. Additional imaging studies generated by CT were done in 3 cases in which the dictated reports were indeterminate for ureteral stones, including negative excretory urography in 2 and retrograde urography in 1. In 1 patient in whom CT misdiagnosed a ureteral stone unnecessary retrograde urography revealed the calcification to be a gonadal vein phlebolith. Seven patients with false-negative examinations reported spontaneous stone passage with no complications. CONCLUSIONS: Unenhanced helical CT accurately determines the presence or absence of ureterolithiasis in patients with acute flank pain. CT precisely identifies stone size and location. When ureterolithiasis is absent, other causes of acute flank pain can be identified. In most cases additional imaging is not required.

Abdomen, Acute↗
PubMed1998

Anatomical alignment for the correction of buried penis.

PURPOSE: We report a straightforward surgical technique for the correction and anatomical alignment of the skin in patients with various degrees of buried penis. MATERIALS AND METHODS: A combined series of 74 patients 7 months to 10 years old who were treated for buried penis at 2 institutions during a 7-year period. Patients presented with various symptoms, including balanitis, urinary tract infection, painful voiding, ballooning of the foreskin and urinary retention. In 29 patients (38%) trapped penis was due to previous circumcision. In our estimation the major anatomical defect in buried penis is an insufficient attachment of the dartos fascia and penile skin to Buck's fascia. Our technique involves making a circumferential incision of the inner preputial skin layer proximal to the corona, unfurling it from the shaft skin and leaving a coronal collar of approximately 1 cm. The annular band that usually constricts the corpora on retraction of the penile skin is incised, and the remaining proximal penile skin and dartos fascia are dissected off Buck's fascia proximally to the base of the penis. The penile dermis is sutured to the lateral aspect of the tunica albuginea at the penopubic junction and mid shaft of the penis. This technique restores normal anatomical relationships with excellent cosmetic results and negligible complications. RESULTS: At a median 5-year followup cosmesis was excellent in all cases. Two patients with micropenis who required revision responded to endocrine therapy. CONCLUSIONS: Excellent cosmetic results were obtained in all cases using this surgical technique.

Child↗
PubMed1997

Autonomous neural axis formation by ectopic expression of the protooncogene c-ski.

The ski oncogene was originally isolated as an avian retroviral gene with the ability to induce quail embryonic cells to differentiate into muscle. Mice containing a chicken c-ski transgene exhibit postnatal hypertrophy of skeletal muscle. Xenopus ski (Xski) protein is maternal and present throughout early development. We show that overexpression of Xski RNA in Xenopus embryos results in the cell-autonomous induction of secondary neural axis formation. Injection of Xski RNA into prospective endodermal cells resulted in the formation of an ectopic neural tube-like structure and cells derived from the injected blastomeres populated the spinal cord. Injected Xski RNA was able to induce neural-specific gene expression directly in ectodermal explants in the absence of the expression of mesodermal markers. The widespread distribution of ski protein in the early gastrula embryo including the dorsal animal region supports a role for ski in neural axis formation in vivo.

Amino Acid Sequence↗
PubMed1997

Localization of prostate cancer metastasis-suppressor activity on human chromosome 17.

BACKGROUND: Prostate cancer is the most commonly diagnosed malignancy in American men. Currently, it is difficult to accurately predict the clinical course of histologically localized prostatic cancer in the individual patient. Identification of markers for metastatic potential of prostate cancer may improve the diagnosis and treatment of this disease. We have previously demonstrated that human chromosome 17 (17pter-q23) suppresses the metastatic ability of AT6.1 rat prostatic cancer cells. In this study we report on the further localization of the metastasis suppressor activity encoded by human chromosome 17. METHODS: A series of AT6.1-17 microcell hybrids was constructed using microcell-mediated chromosomal transfer of human chromosome 17 into highly metastatic AT6.1 cells. Hybrids which had spontaneously deleted regions of chromosome 17 were analyzed by PCR for the presence of 32 sequence-tagged sites (STS) markers as well as the prostate cancer tumor-suppressor loci reported on 17q. In addition, we examined a number of candidate genes and markers that previously have been mapped to chromosome 17. The in vivo metastatic potential of these AT6.1-17 deletion hybrids was determined. RESULTS: We have localized metastasis-suppressor activity to a approximately 70-centiMorgan (cM) portion of chromosome 17, consisting of three distinct regions of 30 cM (D17S952-->D17S805), 6 cM (D17S930-->D17S797), and 34 cM (D17S944-->D17S784). Three of the four markers on 17p13, including HIC1 and TP53, and 12 of the 13 markers in 17q21-23, including BRCA1 (D17S855) and NM23 (NME1), were not retained in the conserved approximately 70-cM metastasis-suppressor region. CONCLUSIONS: These results support a role for a novel metastasis-suppressor gene(s) or a novel metastasis-suppressor function on chromosome 17. Complementary candidate gene and positional cloning approaches are being used to identify the gene(s) within the approximately 70-cM conserved region responsible for metastasis suppression.

Animals↗
PubMed1997

Xyloglucan undergoes interpolymeric transglycosylation during binding to the plant cell wall in vivo: evidence from 13C/3H dual labelling and isopycnic centrifugation in caesium trifluoroacetate.

Xyloglucan from the walls of Rosa cells that had been cultured on [12C]- or [13C]-glucose formed bands in caesium trifluoroacetate with mean buoyant densities of 1.575 or 1.616 g/ml respectively. Incubation of a mixture of [13C,3H]xyloglucan and [12C,1H]xyloglucan in the presence of xyloglucan endotransglycosylase (XET) activity caused the mean buoyant density of the radioactive material to decrease, indicating that interpolymeric transglycosylation could be detected in vitro. We used two 13C/3H-dual-labelling protocols to look for interpolymeric transglycosylation in vivo. In protocol A, [13C]glucose-grown Rosa cells were transferred into [12C]glucose medium 6 h after a approximately 2 h pulse of l-[1-3H]arabinose (which radiolabels the xylose residues of xyloglucan). The mean buoyant density of the wall-bound [3H]xyloglucan decreased during the following 7 days in culture. This indicates that, during or after the wall-binding of newly synthesized [12C,1H]xyloglucan, it became covalently attached to previously wall-bound [13C, 3H]xyloglucan. In protocol B, [12C]glycerol- or [12C]glucose-grown Rosa cells were transferred into [13C]glucose medium, 20 or 60 min before a approximately 2 h pulse of [3H]arabinose. The buoyant density of the earliest wall-bound [3H]xyloglucan showed that it had a 12C/13C ratio of approximately 1:1. This indicates that, during (or, implausibly, before) wall-binding, the newly synthesized [13C, 3H]xyloglucan became covalently attached to previously synthesized [12C]xyloglucan. During the following 7 days in culture, the mean buoyant density of the [3H]xyloglucan increased, showing that later-synthesized [13C,1H]xyloglucan can be covalently attached to previously wall-bound [12C,13C,3H]xyloglucan. The only known mechanism by which segments of xyloglucans could become covalently attached to each other in the cell wall is by interpolymeric transglycosylation catalysed by XET. We conclude that XET-catalysed interpolymeric transglycosylation accompanies, and probably causes, the integration of newly secreted xyloglucan into the cell-wall architecture.

Carbon Isotopes↗
PubMed1997

Adenoviral constructs encoding phosphorylation-competent full-length and truncated forms of the human retinoblastoma protein inhibit myocyte proliferation and neointima formation.

BACKGROUND: The retinoblastoma (Rb) protein is a key cell-cycle regulator that controls entry into the S phase by modulating the activity of the E2F transcription factor. We analyzed the effects of full-length phosphorylation-competent and a mutant truncated form of human Rb for their effects on vascular smooth muscle cell (VSMC) proliferation and neointima formation. METHODS AND RESULTS: A number of mutant forms, both phosphorylation competent and incompetent, of human Rb protein were evaluated for their ability to inhibit E2F activity. The results of these assays indicated that a phosphorylation competent, amino-terminal-truncated Rb protein (Rb56) was a particularly potent inhibitor of E2F-mediated transcription relative to the full-length Rb construct (Rb110). Adenoviral constructs containing Rb56 or Rb110 expressed their respective Rb forms in VSMCs, as determined by Western immunoblot analysis, and were similar in their abilities to arrest the cell cycle, as determined by assays of 3H-thymidine incorporation and by flow cytometric analyses. When examined for their effect on neointima formation after balloon injury of the rat carotid artery, both full-length and truncated forms of Rb inhibited formation of this VSMC-derived lesion. CONCLUSIONS: These analyses revealed that the maintenance of high levels of phosphorylation-competent human Rb, either full-length or truncated forms, in VSMCs is an effective method of modulating the extent of intimal hyperplasia that occurs after balloon-induced vascular injury.

Adenoviridae↗
PubMed1997

p21CIP1-mediated inhibition of cell proliferation by overexpression of the gax homeodomain gene.

gax, a diverged homeobox gene expressed in vascular smooth muscle cells (VSMCs), is down-regulated in vitro by mitogen stimulation and in vivo in response to vascular injury that leads to cellular proliferation. Recombinant Gax protein microinjected into VSMCs and fibroblasts inhibited the mitogen-induced entry into S-phase when introduced either during quiescence or early stages of G1. Overexpression of gax with a replication-defective adenovirus vector resulted in G0/G1 cell cycle arrest of VSMCs and fibroblasts. The gax-induced growth inhibition correlated with a p53-independent up-regulation of the cyclin-dependent kinase inhibitor p21. Gax overexpression also led to an association of p21 with cdk2 complexes and a decrease in cdk2 activity. Fibroblasts deficient in p21 were not susceptible to a reduction in cdk2 activity or growth inhibition by gax overexpression. Localized delivery of the virus to denuded rat carotid arteries significantly reduced neointima formation and luminal narrowing. These data indicate that gax overexpression can inhibit cell proliferation in a p21-dependent manner and can modulate injury-induced changes in vessel wall morphology that result from excessive cellular proliferation.

Adenoviridae↗
PubMed1997

Prospects for intravascular gene therapy.

The goal of this review is to provide an overview of gene delivery systems and candidate genes currently being evaluated for genetic strategies in vascular gene therapy. We will discuss treatment strategies that have been shown by in vivo model systems to be efficacious in promoting neovascularization of ischemic tissue or limiting post-interventional restenosis by inhibiting smooth muscle cell proliferation and/or encouraging re-endothelialization.

Animals↗
PubMed1997

Percutaneous delivery of the gax gene inhibits vessel stenosis in a rabbit model of balloon angioplasty.

OBJECTIVES: The expression of gax, an anti-proliferative homeobox gene, is rapidly downregulated in vascular smooth muscle cells (VSMCs) following arterial injury. Here we performed percutaneous adenovirus-mediated gene transfer into the iliac arteries of normal rabbits using a channel balloon catheter to assess the effects of gax overexpression on neointima formation, lumen diameter, reendothelialization and functional vasomotion. METHODS: A channel balloon catheter was used to perform both the arterial injury and local gene delivery. In each animal both iliac arteries were randomly assigned to receive either an adenovirus expressing the gax gene (Ad-Gax) or the beta-galactosidase gene (Ad-beta gal). In a second group of animals arteries were randomly assigned to receive either Ad-beta gal or saline. RESULTS: At one month, angiography revealed 36% less luminal narrowing in the Ad-Gax-treated arteries relative to the Ad-beta gal-treated control arteries. Histological analysis revealed that the intimal/medial ratio (I/M) was reduced by 56% in the Ad-Gax group. Endothelium-dependent vasomotion was not affected by the gax gene transfer. In the second group, no statistically significant differences were found between the saline and the Ad-beta gal-treated vessels for any of these parameters. CONCLUSIONS: Percutaneous adenovirus delivery of the gax gene to rabbit iliac arteries following endothelial denudation and vessel wall injury reduces neointimal hyperplasia and luminal stenosis, but does not affect endothelium-dependent vasomotion. This study demonstrates that a VSMC transcription factor can potentially be utilized for the development of a molecular therapy for vascular disorders.

Adenoviridae↗
PubMed1997

Advances in the imaging of renal infection. Helical CT and modern coordinated imaging.

Traditionally, imaging of renal infections was largely through a multimodality approach. Excretory urography, ultrasonography, nuclear scintigraphy, and CT all played major roles; however, in recent years, CT has increased in prominence in the imaging and evaluation of renal infection. Part of the reason for this trend includes improvements in the availability of CT scanners and more timely access to them. Helical scanning technology has also greatly increased the quality and usefulness of the information CT provides. Most uncomplicated cases of acute renal infection in adults do not require imaging for diagnosis and treatment. When imaging is indicated, however, contrast-enhanced CT almost always is the study of choice. For cases in which renal calculi may be present, the study should also include noncontrast images through the kidneys.

Abscess↗
PubMed1997

Small bowel dysmotility in patients with postcholecystectomy sphincter of Oddi dysfunction.

Postcholecystectomy patients (N = 27) with severe recurrent biliary-like pain who had no evidence of organic disease were subdivided into those with and those without objective evidence of sphincter of Oddi dysfunction (SOD) based on two separate criteria: (1) clinical criteria-elevated liver function tests and/or amylase with pain, and/or a dilated bile duct, and/or delayed drainage at ERCP (N = 14, SOD classes I and II); and (2) abnormal biliary manometry (N = 19). Prolonged (24-48 hr) ambulant recording of duodenojejunal motor activity was performed in all patients and interdigestive small bowel motor activity compared between patient subgroups and a healthy control group. Phase II motor abnormality was more frequent in patients with, compared to those without, objective clinical criteria of SOD (7/14 vs 0/13, P = 0.003). Phase III abnormality also tended to be more frequent in these patients (7/14 vs 2/13, P = 0.06). In addition, both phase III (P = 0.03) and phase II (P = 0.03) motility index (MI) was higher in patients with sphincter dyskinesia compared to controls; phase II MI was also higher in patients with sphincter stenosis (P = 0.005). Disturbances of small bowel interdigestive motor activity are more prevalent in postcholecystectomy patients with, compared to those without, objective evidence of SOD, and especially in patients with SO dyskinesia. Postcholecystectomy SOD in some patients may thus represent a component of a more generalized intestinal motor disorder.

Adult↗
PubMed1997

Intraductal papillary-mucinous neoplasm of the pancreas: a report of five cases with immunohistochemical findings.

Five cases of intraductal papillary-mucinous neoplasm (IPMN) of the pancreas are here described. This group of tumors represents a distinct clinicopathological entity with characteristic endoscopic, radiological, gross and microscopic appearances. Our five cases all showed marked dilatation of the main pancreatic duct which contained mucin and papillary tumor, sometimes filling and sometimes lining the lumen. The papillae were lined by columnar epithelium showing varying degrees of dysplasia. In one case there was adjacent invasive adenocarcinoma. Immunohistochemical staining for p53 protein was strongly positive in a majority of cells in the three cases with severe epithelial dysplasia and in the invasive adenocarcinoma, while weaker staining in a minority of cells was seen in the remaining two cases. A small proportion of tumor cells expressed PCNA and Ki-67 immunohistochemically in four cases, while the case with severe dysplasia and invasive carcinoma showed positivity for these proliferation markers in most cells. The four cases of exclusively intraductal tumor showed no evidence of disease recurrence at follow-up (median 55 months). The patient with IPMN and associated invasive adenocarcinoma died 21 months post-operatively. In view of its relatively favourable prognosis, it is important that IPMN is recognised.

Adenocarcinoma, Mucinous↗
PubMed1997

Rotator cuff: evaluation with fast spin-echo versus conventional spin-echo MR imaging.

PURPOSE: To determine if fast spin-echo (SE) magnetic resonance (MR) imaging can provide similar information to that of conventional SE imaging for evaluation of the rotator cuff. MATERIALS AND METHODS: One hundred twenty-six patients underwent MR imaging with conventional SE and non-fat-suppressed fast SE sequences (65 patients) or conventional SE and fat-suppressed fast SE sequences (61 patients). Two radiologists independently graded the rotator cuff with separate and side-by-side assessment of the fast SE and conventional SE images. RESULTS: For detection of full-thickness tears, agreement between non-fat-suppressed fast SE and conventional SE images was 93.8% (kappa = 0.78 [good]) and 95.4% (kappa = 0.82 [very good]) for the two readers, respectively, and agreement between fat-suppressed fast SE and conventional SE images was 98.4% (kappa = 0.96 [very good]) and 91.8% (kappa = 0.73 [good]) for the two readers, respectively. Rotator cuff grading was similar for fast SE and conventional SE: weighted kappa = 0.77 (good) and 0.68 (good) for non-fat-suppressed and weighted kappa = 0.83 (very good) and 0.67 (good) for fat-suppressed fast SE images for the two readers, respectively. CONCLUSION: Fast SE sequences yield similar interpretations as those obtained with a conventional SE sequence for evaluation of the rotator cuff.

Adolescent↗
PubMed1997

Can running cause the appearance of marrow edema on MR images of the foot and ankle?

PURPOSE: To determine if runners have an increased prevalence of marrow edema in the foot and ankle compared with nonrunners at magnetic resonance (MR) imaging. MATERIALS AND METHODS: Ankles and feet were imaged in 20 runners and 12 nonrunners with a fast short inversion time inversion-recovery sequence at 1.5 T. Edema within each bone was graded from 0 (no edema) to 3 (severe edema). Total scores for each subject equaled the sum of the grades. RESULTS: Reader 1 found edema in 16 of 20 runners and four of 12 nonrunners (P < .04); runners had a mean score of 4.7 and nonrunners had a mean score of 0.9 (P < .006). The average number of bones with edema was 3.4 for runners and 0.7 for nonrunners (P < .005). Reader 2 found edema in 16 of 20 runners and two of 12 nonrunners (P < .002); runners had a mean score of 4.5 and nonrunners had a mean score of 0.3 (P < .001). The average number of bones with edema was 3.6 for runners and 0.3 for nonrunners (P < .001). CONCLUSION: When the fast short inversion time inversion-recovery sequence is performed, edema seen within the marrow of runners on MR images may be due to exercise alone.

Adult↗