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T Hyslop

Publications and source records attributed to T Hyslop.

28 records · Page 2Linked to original sources
PubMed1997

Long-term outcome following sympathectomy for complex regional pain syndrome type 1 (RSD).

We performed a retrospective study of 29 patients with CRPS1 (RSD) who were initially examined between 1983 and 1993, and had either transthoracic (lower third of stellate ganglia to T3) or lumbar (L2-L4) sympathectomy. The patients were followed from 24 to 108 months after surgery. Patients with unsuccessful surgical outcomes had significantly longer duration of symptoms before surgery (median, 36 months) than those with successful outcomes (median, 16 months) by Wilcoxon rank sum test (chi2=8.69, df=1, P<0.01). All seven patients (100%) who had sympathectomy within 12 months of injury, nine of 13 patients (69.2%) who had sympathectomy within 24 months of injury, and only four of nine patients (44.4%) who had sympathectomy after 24 months of injury obtained permanent (greater than 24 months) symptom relief. Patient age, sex, occupation, site of injury, type of injury, presence of trophic changes, and duration of follow-up were not significantly related (P>0.05) to surgical outcome.

Adult↗
PubMed1997

External beam irradiation for choroid metastases: identification of factors predisposing to long-term sequelae.

PURPOSE: To improve overall quality of life, palliative treatments should attempt to minimize associated complications while effectively controlling specific symptoms. We reviewed our experience treating posterior uveal metastases with external beam radiotherapy (EBRT) to determine the complication rate and to identify the relationship between patient, tumor, or treatment-related factors and the development of ocular complications. METHODS AND MATERIALS: 483 consecutive patients (pts) (578 eyes) were diagnosed with intraocular metastatic disease from solid tumors between 1972-1995. Of these, 233 eyes (188 pts) had lesions of the posterior uveal tract and received EBRT. Median follow-up time was 5.8 months (range: 0.7-170.0 months). Follow-up information regarding the development of complications was documented for 230 eyes. Complete EBRT details were available for 189 eyes. Seventy-two percent of the patients received 30.0-40.0 Gy in 2.0-3.0 Gy fractions. Biologically effective dose (BED) was calculated to allow meaningful comparisons between various fractionation regimens and total doses. Concurrent chemotherapy and/or hormonal therapy was used for 101 eyes (44%). RESULTS: Median BED was 61 Gy3 (range, 6.7-105 Gy3), and 80% of treated eyes received BED 50-70 Gy3. EBRT energies included photons (70%), 60Co (19%), electrons (6%), mixed energies (3%), and orthovoltage (2%). Lens-sparing techniques were used in 136 eyes (71%). At last follow-up 28 eyes (12%) developed one or more significant complications, including cataracts (16 eyes), radiation retinopathy (6 eyes), optic neuropathy (5 eyes), exposure keratopathy (5 eyes), and neovascularization of the iris (4 eyes). Two eyes developed narrow-angle glaucoma, and one of these required enucleation. On univariate analysis, Caucasian race (vs. Black/Hispanic, p = 0.03), increased intraocular pressure at diagnosis (>21 mmHg, p = 0.02), and diagnosis by biopsy (vs. no biopsy, p = 0.03) predisposed toward the development of complications. Factors not correlated with complications included BED (p = 0.18), energy type (p = 0.81), lens-sparing technique (versus whole globe, p = 0.57), and concurrent systemic treatment (p = 0.60). The small number of complications did not support a multivariate analysis. CONCLUSIONS: Despite the employment of a variety of EBRT treatment techniques and the proximity of choroidal metastases to radiosensitive structures, significant complications of palliative EBRT were infrequent. Although complications do occur, they are related to host factors and do not appear to be a function of irradiation parameters. We conclude that the potential benefits of vision and globe preservation after palliative EBRT outweigh the small risk of treatment induced complications.

Adult↗
PubMed1997

Prostate imaging may not be necessary in nonpalpable carcinoma of the prostate.

OBJECTIVES: Stage T1c carcinoma of the prostate is defined as a nonpalpable carcinoma (NPC-P) that is not visible by imaging and is identified by needle biopsy performed because of elevated prostate-specific antigen (PSA) concentrations. The purpose of this study was to define the incidence of normal findings on transrectal ultrasound (TRUS) and/or endorectal coil magnetic resonance imaging (EMRI) among patients with NPC-P, as well as to investigate the value of differentiating patients with Stage T1c disease from all other patients with NPC-P. METHODS: The records of 2211 patients diagnosed with prostate carcinoma between 1988 and 1995 were reviewed to identify 291 men with NPC-P. TRUS and EMRI reports were analyzed with regard to the presence and laterality of hypoechoic nodules or low-signal areas reported on T2-weighted images, respectively. Ninety percent of patients (n = 262) had at least six prostate biopsies, 185 patients (64%) underwent both TRUS and EMRI, 224 (77%) had TRUS, and 251 (86%) had an EMRI study. RESULTS: Results were considered normal in 101 (47%) of 214 patients undergoing TRUS, in 58 (23%) of 249 undergoing EMRI, and in 22 (12%) of 185 undergoing both TRUS and EMRI. For the side of the prostate with positive biopsy results, correlation with imaging abnormalities was better for EMRI than for TRUS (39% versus 24%). There was no significant difference in mean PSA value, distribution of Gleason score, or unilateral versus bilateral positive biopsy results among patients with normal versus abnormal findings on both TRUS and EMRI. CONCLUSIONS: (1) Only 12% of men with NPC-P have no TRUS or EMRI abnormalities, fulfilling the criteria for Stage T1c prostate carcinoma. (2) Those patients with Stage T1c disease do not differ from patients with NPC-P up-staged by TRUS or EMRI, with regard to pretreatment PSA levels, Gleason scores, and the probability of having bilateral rather than unilateral positive biopsy results. (3) The value of classifying patients with NPC-P into Stage T1c versus higher stages of prostate carcinoma on the basis of imaging should be questioned.

Adenocarcinoma↗
PubMed1997

Functional vision is improved in the majority of patients treated with external-beam radiotherapy for choroid metastases: a multivariate analysis of 188 patients.

PURPOSE: Metastatic deposits are the most common intraocular malignancies. We evaluated the efficacy of external-beam radiotherapy (EBRT) in the palliation of posterior uveal metastases in terms of clinically relevant outcomes: functional vision, tumor control, and globe preservation. PATIENTS AND METHODS: Four hundred eighty-three consecutive patients (578 eyes) were diagnosed with intraocular metastatic disease from solid tumors between 1972 and 1995. Of these, 233 eyes (188 patients) had lesions of the posterior uveal tract and received EBRT. Best-corrected visual acuity (VA) was documented pre- and post-EBRT. Visual function was considered excellent if VA < or = 20/50, navigational if 20/60 to 20/200, and legally blind if > or = 20/400. Most patients received 30 to 40 Gy in 2- to 3-Gy fractions to the posterior or entire globe. RESULTS: Fifty-seven percent of all assessable eyes had improved visual function or maintained at least navigational vision following EBRT. Thirty-six percent of legally blind eyes regained useful vision. Ninety-three percent experienced no clinical evidence of tumor progression and the globe preservation rate was 98%. The following characteristics independently predicted improvement to or maintenance of excellent vision on multivariate analysis: excellent vision pre-EBRT (P = .001), age less than 55 years (P = .004), white race (v black/Hispanic) (P = .003), and tumor base diameter less than 15 mm (P < .001). CONCLUSION: EBRT effectively restores and maintains useful vision in patients with choroid metastases, with a globe preservation rate of 98%. Patients less than 55 years with pretreatment VA better than 20/60 and tumor diameter less than 15 mm are most likely to benefit from this therapeutic intervention.

Adult↗
PubMed1996

Induction androgen deprivation plus prostatectomy for stage T3 disease: failure to achieve prostate-specific antigen-based freedom from disease status in a phase II trial.

OBJECTIVES: There is interest in treating prostate cancer with induction androgen deprivation prior to radical prostatectomy. Data on long-term prostate-specific antigen (PSA)-based survival analyses among patients treated with neoadjuvant hormonal therapy (NHT) and prostatectomy are limited. In 1991 we instituted a pilot study for T3 disease based on endorectal coil magnetic resonance imaging (eMRI), mandatory negative laparoscopic nodal dissection prior to hormonal manipulation, and prostatectomy followed by pathologic and PSA-based outcome determinations. METHODS: Of 26 patients, 21 had negative laparoscopic lymphadenectomy followed by 4 months of NHT (leuprolide +/- flutamide) prior to radical prostatectomy. eMRI was performed at the time of diagnosis and following hormonal treatment. Serum PSA was determined at 3-month intervals. Prostatectomy specimens were evaluated by 3-mm whole-mount step sections. RESULTS: Prior to prostatectomy, biochemical response was documented in all patients and downsizing was observed by eMRI in 57%. Pathologic downstaging to a lower stage (T2c or lower) was achieved in 48%. However, the actuarial 3-year freedom from biochemical relapse rate was only 24%. CONCLUSIONS: Using laparoscopy to exclude node-positive patients and 4 months of NHT appears to result in pathologic and initial biochemical evidence of regression. These factors have not translated into improved freedom from biochemical relapse among patients with Stage T3 disease treated with NHT and prostatectomy. Recent data strongly suggest a beneficial effect in patients with clinical T2 disease treated with NHT and radical prostatectomy. The NGT and radical prostatectomy approach appeared to offer no clear advantage when compared with PSA-based benchmarks achieved with conformal irradiation or NHT followed by external beam treatment among patients with clinical T3 disease.

Aged↗
PubMed1996

Mean difference vs. variability reduction: tradeoffs in aggregate measures for individual bioequivalence. FDA Individual Bioequivalence Working Group.

Aggregate criteria for individual bioequivalence allow a tradeoff between difference in average bioavailability and reduction in within-subject variability. That is, a large difference in the average bioavailability between a test and a reference formulation can be offset by a sufficient reduction in variability of the test formulation. This offset could allow the test formulation to pass many individual bioequivalence criteria. We have identified 4 possible approaches for dealing with this tradeoff issue: say "No problem," since a reduction in variability is desirable; use disaggregate criteria; use general weighted forms of the individual bioequivalence criteria that weight the variance terms; and change the acceptable upper limits to reduce the impact of scaling to the reference formulation's within-subject variability. A dataset with a 14% increase in average bioavailability and a 48% reduction in within-subject standard deviation is used as an example of these issues.

Biological Availability↗
PubMed1995

Cytokine patterns during progression to AIDS in children with perinatal HIV infection.

Patterns of cytokine expression were analyzed in polyclonal and antigenic responses in children with perinatal HIV infection. Responses of PBL to PMA and A23187 calcium ionophore studied in patients in different stages of HIV infection revealed reduced levels of IL-2 in HIV-infected children beginning before 6 mo of age, and age-dependent increases in expression of IL-4, IL-10, and IFN-gamma. The levels of IL-4, IL-10, and IFN-gamma expression did not differ significantly between HIV-infected and age-matched uninfected children of HIV-seropositive mothers, except for a small reduction in HIV-infected children in late stages of infection. Responses to PHA, HLA alloantigens, HIV envelope peptides T1 and P18, and tetanus toxoid were studied in PBMC derived from asymptomatic and mildly symptomatic HIV-infected children. IL-2, IFN-gamma, IL-4, and IL-5 expression was detected in PHA-stimulated PBMC from all analyzed patients. HIV-infected children who failed to respond to HLA alloantigens, tetanus toxoid, or the envelope peptides had lower numbers of CD4+ cells and expressed, on PHA stimulation, higher levels of IL-4 and IL-5 and lower levels of IL-2 and IFN-gamma than patients who responded to the antigenic stimulation. Results of these analyses suggest that cytokine expression in HIV-infected children depends on the character of the stimuli as well as the phenotype of PBMC, and indicate possible prevalence of Th2 Ag-specific responses during the progression of HIV-induced immunodeficiency.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Muscle sodium channel inactivation defect in paramyotonia congenita with the thr1313met mutation.

Mutations of the skeletal muscle sodium (Na) channel have been reported in families with paramyotonia congenita (PC), an autosomal dominant disorder with cold and/or exercise induced stiffness and myotonia. Functional consequences of specific Na channel mutations responsible for PC have not been described. Patch clamp recording of single Na channels were made in cultured myotubes at 22 and 34 degrees C from a PC patient with the thr1313met mutation. Cell-attached and outside-out recordings of mutant PC channels contained long duration and late openings. The mean open time was increased and the ensemble average showed a prolonged inward Na current. This membrane depolarization could cause repetitive action potentials and the clinical syndrome.

Amino Acid Sequence↗
PubMedDate not supplied

Performance status and age as independent predictors of survival among AIDS patients with primary CNS lymphoma: a multivariate analysis of a multi-institutional experience.

PURPOSE: There is limited information about the outcome of AIDS patients with primary central nervous system lymphoma treated with definitive irradiation. The purpose of this study was to determine factors associated with increased survival in such patients. METHODS: An analysis was performed of 163 patients with AIDS who were evaluated at nine urban hospitals. These patients were treated for primary central nervous system lymphoma after the establishment of a tissue diagnosis or on a presumptive basis after failing empiric treatment for toxoplasmosis. All patients were treated between 1983 and 1995 with radiotherapy (median dose-fractionation scheme = 3 Gy x 10) and steroids (> 90% dexamethasone). Because multiple fractionation schemes were used, prescriptions were converted to biologically effective dose according to the formula Gy10 = Total Dose x (1 + fractional dose/alpha-beta), using an alpha-beta of 10. RESULTS: Longer median survival times were associated with high Karnofsky performance status (KPS > or = 70 vs < or = 60: 181 vs 77 days), young age (< 35 vs > 35: 162 vs 61 days), and high total definitive irradiation doses (> 39 Gy10 vs < 39 Gy10: 162 vs 40 days). Tissue diagnosis, gender, race, number of lesions (solitary vs multiple), and the presence of other cancers did not influence outcome. In multivariate analysis, young age, high Karnofsky performance status, and the delivery of higher biologically effective doses of irradiation retained independent significance relative to the endpoint of survival. CONCLUSIONS: Even at urban tertiary medical centers, few AIDS patients with intracranial lesions undergo biopsies to establish a precise tissue diagnosis. Survival following definitive irradiation is strongly related to two pretreatment factors (young age, high performance status) and one treatment factor (total biologically effective dose of cranial radiotherapy). These variables should be considered in selecting patients for definitive irradiation and in designing future studies.

Acquired Immunodeficiency Syndrome↗