PubMed Health⌕ Search

Biomedical subjects

R Hawkins

Publications and source records attributed to R Hawkins.

At least 73 records · Page 4Linked to original sources
PubMed1994

Role of 99mTc-labeled DISIDA scan in the assessment of marginal liver grafts after orthotopic transplantation.

Accurate prognostic indicators are lacking for livers with early marginal graft function, making the decision to re-transplant a difficult one. Therefore, we studied 99mTc-labeled DISIDA scanning as a predictor of recovery of marginal grafts. Records of 28 liver transplant recipients with prolonged periods of marginal graft function after liver transplantation were analyzed. Twelve of 28 (Group I) had delayed PNF and were re-transplanted within 3-8 days (mean 5.3) of surgery. The remaining 16 (Group II) recovered slowly, with normal graft function at 1 month. All patients received DISIDA scans 2 to 5 d after surgery. Clearance of tracer from the blood pool was slower in Group I patients (77S +/- 241 sec) than in Group II (260 +/- 38 sec; p < 0.01). Qualitative differences in the pattern of parenchymal uptake were also noted. Homogenous uptake, consistent with cholestasis, was seen in 15/16 (94%) Group II patients, with improved uptake after 7-35 d. In contrast, 11/12 Group I patients had non-homogenous uptake, consistent with multiple liver infarctions. This pattern correlated with higher peak SGOT in Group I (4358 +/- 658 U/dl vs 1636 +/- 127 U/dl p < 0.01), and PT (20 +/- 0.7 sec vs. 16.5 +/- 0.36 sec; p < 0.01). In summary, delays in DISIDA tracer clearance from blood, and non-homogenous hepatic uptake correlate with elevated liver function tests and with delayed PNF. Homogenous uptake correlates with graft recovery. DISIDA scans may, therefore, be useful in predicting recovery of marginal grafted livers.

Adult↗
PubMed1993

Positron emission tomography with fluorodeoxyglucose to evaluate tumor response and control after radiation therapy.

PURPOSE: Following radiation therapy, evaluation of viable tumor can often be difficult with anatomic imaging criteria (tumor size alone). In this study, the utility of biochemical imaging with the glucose analog 2-[F-18]fluoro-2-deoxy-D-glucose and positron emission tomography was investigated in patients treated with radiation therapy. METHODS AND MATERIALS: Between 1990 and 1992, 19 patients were studied, including 15 patients with head and neck cancer, (4 oropharynx, 4 sinus, 3 larynx, 2 hypopharynx, 2 oral cavity [one patient], 1 nasopharynx), and 4 patients with breast cancer. Post-radiation positron emission tomography with 2-[F-18]fluoro-2-deoxy-D-glucose studies were done in all patients, with 9 head and neck patients receiving pre-radiation positron emission tomography with 2-[F-18]fluoro-2-deoxy-D-glucose scans as well. Results were correlated with other imaging techniques and pathology. RESULTS: Positron emission tomography with 2-[F-18]fluoro-2-deoxy-D-glucose detected head and neck primary tumors and lymph node metastases in all nine pre-radiation scans, while magnetic resonance imaging failed to detect two primary tumors. Serial positron emission tomography with 2-[F-18]fluoro-2-deoxy-D-glucose showed a significant decrease in tumor activity after radiation therapy, compared to pre-radiation levels, (p < 0.05), except for two patients with increased uptake at the primary site. Biopsies of these two patients showed persistent/recurrent disease after radiation therapy, which was not detected by magnetic resonance imaging. Six additional head and neck patients, with suspicious examination and inconclusive magnetic resonance imaging, were imaged with positron emission tomography after radiation therapy only. Five patients had increased positron emission tomography activity, with corresponding biopsies positive in four patients, and negative in one patient with clinically worsening symptoms. The remaining sixth patient had minimal and stable positron emission tomography uptake, and is improving clinically. Four patients had mammogram findings suspicious for recurrence after conservation treatment for breast cancer. Positron emission tomography with 2-[F-18]fluoro-2-deoxy-D-glucose showed no focal activity in the breast in two patients, and increased activity in the area suspicious for recurrence in the other two patients. Biopsies correlated with positron emission tomography results. CONCLUSION: Changes and presence of positron emission tomography with 2-[F-18]fluoro-2-deoxy-D-glucose activity correlated with pathologic findings in head and neck and breast cancer patients in this series. In patients with elevated or rising positron emission tomography activity after radiation therapy, persistent or recurrent disease was found in 89% of patients, (8/9). Magnetic resonance imaging did not detect the head and neck recurrences, and mammography was suspicious in patients with both benign and malignant breast changes after radiation therapy. In addition, our data indicate that in head and neck patients with pre-radiation positron emission tomography scans, a significant decrease in activity should occur after radiation therapy, if local control is to be expected.

Adult↗
PubMed1993

Cyclosporine in systemic sclerosis. Results of a forty-eight-week open safety study in ten patients.

OBJECTIVE: To evaluate safety and efficacy of cyclosporin A (CSA) treatment in systemic sclerosis (SSc). METHODS: Ten patients with < or = 60 months of SSc were entered into a 48-week open study of CSA. Patients with hypertension or azotemia were excluded. Concurrent use of nonsteroidal antiinflammatory agents or diuretics was not permitted. The extent of cutaneous and visceral involvement at 48 weeks and at study entry were compared. RESULTS: Adverse reactions (especially nephrotoxicity) were frequent, usually transient, often dose-limiting, and usually associated with CSA doses > or = 3-4 mg/kg/day. Skin thickening decreased significantly (P < 0.001), while pulmonary and cardiac involvement remained unchanged. CONCLUSION: CSA should undergo blinded controlled study in patients with SSc.

Adult↗
PubMed1993

Whole-body positron emission tomography with (fluorine-18)-2-deoxyglucose can detect metastatic carcinoma of the fallopian tube.

Distant sites of metastatic fallopian tube carcinoma, including humerus, umbilicus, and groin, were clearly imaged with FDG-PET; the surgical-pathologic correlations are presented. In disorders such as ovarian or fallopian tube cancer, where a reliable means of diagnosing persistent or recurrent disease remains elusive, PET scanning offers another approach to this problem. Based on the increased rate of glucose metabolism in tumors, this modality focuses on the biochemical differences between malignant tissues and their normal counterparts in order to demonstrate positive findings on imaging. Potential uses of PET scanning in gynecologic oncology are presented.

Adenocarcinoma, Papillary↗
PubMed1993

Whole-body positron emission tomography with 2-[18F]-fluoro-2-deoxy-D-glucose can detect recurrent ovarian carcinoma.

The existing means of detecting recurrent ovarian carcinoma are notoriously poor. Positron emission tomography (PET) is a form of computer-assisted imaging which produces images reflective of the biochemistry of the tissues rather than their physical characteristics. PET imaging with the positron emitting glucose analog 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) exploits the accelerated rate of glycolysis characteristic of malignant tissue to image tumors. To begin to study PET's ability to diagnose recurrent ovarian cancer, whole-body PET FDG scanning was performed on 13 patients prior to planned surgical exploration. Seven patients were suspected of having recurrence based upon clinical findings, and 6 patients were clinically free of disease. In all 6 of the patients with suspected recurrence who subsequently underwent surgery, PET images demonstrated increased FDG uptake in a distribution that correlated with surgical-pathologic findings. Both intraperitoneal and extraperitoneal lesions were detected by PET. All 6 patients judged clinically free of disease had negative PET scans, but in 5 of these microscopic foci of residual tumor were found at surgery. Although PET FDG cannot replace surgery in the detection of microscopic recurrence, it can accurately detect tumors greater than 1.0 cm in diameter.

Adult↗
PubMed1993

Hyperplastic neuroretinopathy and disorder of pigment epithelial cells precede accelerated retinal degeneration in the SJL/N mouse.

We have found a complex eye disease in the SJL/N mouse. This animal is closely related to the SJL/J mouse, which is homozygous for retinal degeneration (rd) and which also suffers from extraocular reticulum cell sarcomas at around 200 days of age. In the SJL/N animal, a high incidence of subretinal tumor is present at 9 days after birth. Furthermore, we have observed an extensive neuroretinal hyperplasia, a phenomenon that is termed "hyperplastic neuroretinopathy", and that is probably the consequence of elevated levels of cytokines in the animals. In addition to these anomalies, the SJL/N mouse shows progressive dystrophy of the retinal pigment epithelium (RPE) from day 4 onwards, and accelerated photoreceptor cell degeneration is completed by day 16. The early RPE dystrophy appears to be a secondary autoimmune disease, since cells in this structure and in the choroid develop MHC class II antigens, whereas we suspect that the accelerated photoreceptor cell loss is induced by a soluble toxic agent. The F1 progeny derived from cross-breeding the SJL/N and Balb/c +/+ strains also shows a high incidence of subretinal tumor and hyperplastic neuroretinopathy, but neither the RPE dystrophy nor retinal degeneration.

Age Factors↗
PubMed1993

An analysis of hypnotherapist-client sexual intimacy.

While sexual interaction between psychologists, physicians, and other health therapists of all kinds and their clients is typically condemned by professional bodies as unethical, the controversy regarding the potential for hypnosis to produce compliant behavior in unwilling or nonconsenting subjects suggests that hypnotherapist-client sex may warrant special attention. Because the experiments required to clarify the potential for hypnosis to potentiate nontrivial compliance are themselves unethical and/or inconclusive, experimental methods cannot be adequately used to clarify this issue. Instead, the matter can be addressed by reference to other forms of evidence, such as the responses of therapists and clients to anonymous surveys and the analysis of cases, that have reached the courts. Consideration of this qualitatively deficient evidence suggests that even if the use of hypnotic suggestion can lead to compliance to sexual demands, overt coercion is seldom used in practice. Social psychological and situational factors are particularly salient in understanding therapist-client sex. The question of whether there are special properties of the dynamics of the hypnotic experience, other than specific coercive suggestion and beyond those typically found in other forms of therapy, is considered. Comparisons are drawn with other examples of socially condemned sex, such as teacher-student sex, sexual harassment in the workplace, incest, and extramarital sex.

Adult↗
PubMed1993

MRI and ultrasound guided interstitial Nd:YAG laser phototherapy for palliative treatment of advanced head and neck tumors: clinical experience.

Interstitial laser phototherapy (ILP) is a technique whereby laser energy is directly applied into tumors at variable depths. This technique is attractive, since it is minimally invasive and carries a low morbidity. It may allow treatment of deep and difficult to reach tumors in the head and neck and other areas when improved noninvasive monitoring techniques of laser-tissue interactions are developed. Recent studies demonstrate, respectively, the efficiency of ultrasound (UTZ) and magnetic resonance imaging (MRI) for real time interstitial needle placement in tumors, identification of vessels, monitoring and quantifying laser-induced tissue damages. We present a case in which a patient with recurrent, metastatic base of skull carcinoma has managed successfully with repeat ILP using MRI and UTZ guidance. Under heavy sedation, needles were placed in the tumor using MRI or UTZ guidance. Tumors were treated with a 600 mum flexible Nd:YAG laser fiberoptic passed through the needles. Laser-induced tissue photoablation was monitored using real time color flow Doppler UTZ or near real time fast spin-echo T2-weighted MRI. Posttreatment fine needle aspiration cytologic study demonstrated the presence of cellular debris and no viable cancer cells. Posttreatment follow-up MRI scans showed significant reduction of tumor size, and positron emission tomography (PET) revealed interval decrease in tumor metabolism. Treatments were accompanied by pain relief and improved functional abilities. ILP has now evolved into minimally invasive outpatient surgical procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Contraindications↗
PubMed1993

Rehabilitation for the overhead athlete.

Rehabilitation of the shoulder of the overhead athlete has undergone significant changes during the past few years. This article illustrates shoulder problems related to repetitive overhead activities, such as throwing. Additionally, we present basic science contributions in this area, principles of shoulder rehabilitation, and a comprehensive rehabilitation program for the symptomatic or asymptomatic athlete based on these principles.

Adult↗
PubMed1993

Use of positron emission tomography in oncology.

Positron emission tomography is an imaging technique that produces images reflective of tissue biochemistry rather than anatomy. Utilizing different isotopes, many biochemical processes can be studied repetitively and non-invasively in cancers in vivo. Malignant tissue is characterized by an accelerated rate of glycolysis. This biochemical characteristic of malignancy can be exploited by PET imaging with the radiopharmaceutical FDG. PET with FDG has been successful in imaging primary and metastatic cancer of the breast, colon, lung, head and neck, as well as sarcomas and lymphomas. PET FDG imaging has potential as a screening, diagnostic and staging tool in cancer. Recently, whole body PET techniques have been developed which permit imaging of the entire body during a single scanning session. PET also has tremendous potential as a cancer research tool to study serial estimates of tumor glycolysis, DNA turnover, oxygen metabolism, protein synthesis, and blood.

Brain Neoplasms↗
PubMed1992

Detection of spores of Bacillus anthracis using the polymerase chain reaction.

The polymerase chain reaction (PCR) was used to identify spores of Bacillus anthracis. By using an assay capable of amplifying a 1247-bp fragment from the gene that encodes the edema factor of B. anthracis, as few as 10(3) copies of a plasmid containing the edema factor gene and as few as 2 x 10(4) spores were detected. Subjecting the product of this PCR to a second PCR designed to amplify a 208-bp fragment nested within the 1247-bp product improved detection to a single plasmid copy per PCR and to two spores of B. anthracis per PCR.

Bacillus anthracis↗
PubMed1991

Renal ultrasound abnormalities in children with end-stage liver disease--reversal by liver transplantation.

Ultrasound (US) imaging of the kidneys was performed in 43 pediatric patients with end-stage liver disease evaluated for orthotopic liver transplantation. Renal size was increased in 8 patients (19%) and echogenicity of the kidneys was increased in 12 patients (28%). In 12 patients studied after liver transplantation, US revealed normal renal size in all and increased echogenicity in only 2 patients shortly after transplantation. Normalization of renal US findings was also found in 2 patients studied before and after liver transplantation. The glomerular filtration rate varied from 65 to 225 ml/min per 1.73 m2 in 5 patients with abnormal US, and from 74 to 116 ml/min per 1.73 m2 in 3 patients with normal US. Nephromegaly and increased echogenicity on renal US are frequent in children with end-stage liver disease and appear to be mostly reversible by liver transplantation.

Adolescent↗
PubMed1990

Evaluation of kidney function in renal transplant patients receiving long-term cyclosporine.

We prospectively assessed renal function in a group of 29 renal transplant patients receiving cyclosporine (CsA) in order to determine the course of their renal function over time and the relationship between different markers of glomerular function. We measured serum creatinine, DPTA, and creatinine clearances, and urinary albumin excretion. The clinical course of 24 patients (83%) permitted repeat studies over a period of 32 +/- 1 (SEM) months, and in these patients DTPA clearance, creatinine clearance, and the serum creatinine concentration did not vary with time. Five of the patients (17%) lost their grafts and returned to dialysis. On initial evaluation patients who lost their grafts had a lower DPTA clearance than those whose function was maintained (29 +/- 3 v 46 +/- 2 mL/min/1.73 m2 body surface area [BSA], respectively, P less than 0.005) and all of them had a DTPA clearance of less than 40 mL/min/1.73 m2 BSA. There was an inverse correlation between the log of the urinary albumin excretion and the DTPA clearance (n = 33, r = -0.59, P less than 0.001), a direct correlation with the serum creatinine concentration (N = 33, r = 0.89, P less than 0.0001), but no correlation with time after transplantation. Thus, despite the continued use of CsA, renal function over time was stable in patients who underwent repeated studies, as was the relationship between the DTPA clearance and the clinically used markers of transplant function, the serum creatinine concentration, and the creatinine clearance.

Albuminuria↗