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Biomedical subjects

J W Walsh

Publications and source records attributed to J W Walsh.

At least 19 recordsLinked to original sources
PubMed1996

MRI of cerebellopontine angle choroid plexus papilloma.

We present a cerebellopontine angle choroid plexus papilloma that originated from the tuft of choroid plexus of the fourth ventricle protruding from the foramen of Luschka. MRI and CT did not establish the diagnosis, but the tumor was shown histopathologically to be a choroid plexus papilloma. Distinct features of the tumor on MRI are described and the differential diagnosis of other cerebellopontine angle tumors is discussed.

Cerebellar Neoplasms↗
PubMed1996

Masses simulating gynecologic diseases at CT and MR imaging.

The majority of pelvic masses in women arise from the reproductive tract. However, diseases of gastrointestinal origin (ruptured appendix, diverticular abscess, perforated rectosigmoid carcinoma), neurogenic origin (ganglioneuromas), primary extraperitoneal origin (presacral teratoma, soft-tissue sarcoma), and other miscellaneous disorders also occur in the pelvis and can be mistaken for gynecologic disease. Although determining the site of origin of a pelvic disease process can be difficult, several imaging signs can help differentiate an intra- from an extraperitoneal mass. These signs include displacement of the pelvic ureter, effacement or encasement of external iliac vessels, effacement of pelvic sidewall musculature, and displacement of the rectum. Depending on its exact location, an extraperitoneal mass can displace the pelvic ureter medially or anteriorly (compared with the lateral or posterolateral displacement caused by an ovarian mass), encase and obliterate the external iliac vessels, efface and compress the external iliac vein, abut and eventually efface the obturator internus muscle, or displace the rectum anteriorly or anterolaterally. Familiarity with these disease processes and the above imaging signs will facilitate accurate diagnosis and triage for treatment.

Adult↗
PubMed1996

Progesterone and estrogen are potential mediators of gastric slow-wave dysrhythmias in nausea of pregnancy.

Women in pregnancy experience nausea, which correlates with gastric slow-wave rhythm disruption. Mediators of these dysrhythmias were explored. To quantitate slow-wave disruption, eight pregnant women with first-trimester nausea underwent electrogastrography after a 250-kcal meal. Results were compared with nonpregnant women with nausea during a prior pregnancy who received estradiol and/or progesterone to levels of the first trimester of pregnancy. Five pregnant women exhibited dysrhythmias, with increases in combined recording time in tachygastria plus bradygastria, as well as decreases in the percentage of electrogastrography signal power in the normal 3 cycle/min range (cpm), compared with nonpregnant women (P<0.05). Estradiol did not evoke dysrhythmias in nonpregnant women; however, progesterone induced increases in recording time in bradygastria plus tachygastria and increases in bradygastric signal power with corresponding decreases in signal power in the 3-cpm range (P<0.05). With estradiol and progesterone coadministration, an additive effect was observed at 3.3 +/- 0.8 h, with increased recording time in bradygastria alone and in bradygastria plus tachygastria with corresponding increases in bradygastric signal power and decreases in power in the 3-cpm range (P<0.05). In conclusion, women with nausea of pregnancy exhibit slow-wave rhythm disruption. Similar dysrhythmias are evoked in nonpregnant women by progesterone alone or in combination with estradiol in doses that reproduce levels in pregnancy. Thus gastric dysrhythmias in pregnancy may be due to a combination of elevated progesterone and estrogen levels.

Adult↗
PubMed1996

Biology of a brain metastasis.

The appearance of a brain metastasis is generally regarded as an ominous event in the progression of many solid tumors because it usually means that the patient will have reduced quality and length of survival. It is important to study the biology of brain metastasis because present treatments are principally palliative and new approaches to diagnosis and treatment are clearly needed.

Animals↗
PubMed1995

PET and SPECT imaging for stereotactic localization.

Stereotactic localization using PET and SPECT has been used together with the Leksell stereotactic frame and the other imaging tools routinely provided to Gamma Knife radiosurgery sites. The accuracy of the measurements has been confirmed with CT and MR using a Radiation Analog Dosimetry phantom. The activity of the radionuclide solution placed in the tubes of Elekta Radiosurgery's MR imaging box is somewhat critical because the window levels chosen for the scan will affect the apparent size of the lesion. A technique is presented to resolve areas of activity more than about 12-14 mm apart, and it may prove useful in targeting epileptogenic sites in patients with medically intractable epilepsy.

Humans↗
PubMed1994

Thallium-avid cerebral radiation necrosis.

Thallium imaging has been proposed as a noninvasive method to distinguish recurrent tumor from cerebral radiation necrosis in patients who have undergone radiation therapy. Previous reports have supported the intuitive hypothesis that metabolically active tumor tissue would accumulate Tl-201 to a much higher degree than nonviable necrotic tissue. A case of biopsy-proven cerebral radiation necrosis is presented demonstrating a degree of Tl-201 avidity previously thought to be diagnostic of recurrent tumor. Based on this finding, it is concluded that a high degree of Tl-201 uptake does not exclude the diagnosis of cerebral radiation necrosis.

Brain↗
PubMed1994

CT anatomy of the female pelvis: a second look.

Computed tomography (CT) remains a valuable technique in the assessment of the female pelvis. The CT appearance of the normal ligamentous, vascular, and visceral anatomy of the female pelvis can be confusing. Newer high-resolution CT scanners combined with mechanical intravenous contrast medium injectors and thinner sections have substantially improved the imaging of female genital tract anatomy. In addition to the cardinal, uterosacral, and round ligaments, the ovaries and their ligamentous attachments, as well as the blood supply to the female internal organs, can now be visualized. Inferior-to-superior image acquisition following bolus administration of intravenous contrast material with an angiographic injector facilitates precise identification of the uterine artery and its relationship to the pelvic ureter and the vascular plexus supplying the vagina, ovaries, and uterine body. Ideally, familiarity with variations in the CT appearance of normal female pelvic anatomy will enable more accurate evaluation of pelvic abnormalities.

Adult↗
PubMed1993

Ground-glass opacity of the lung parenchyma: a guide to analysis with high-resolution CT.

Ground-glass opacity is a frequent but nonspecific finding on high-resolution CT scans of the lung parenchyma. The underlying abnormality is diverse; any condition that decreases the air content of the lung parenchyma without totally obliterating the alveoli can produce ground-glass opacity. These processes are not visible on high-resolution CT scans. However, in specific clinical settings, the information provided by high-resolution CT is considerable when the anatomic distribution and associated structural changes to the lung parenchyma are analyzed. This pictorial essay illustrates the pathologic basis of ground-glass opacity and provides a guide to the differential diagnosis of the disorders that can produce this appearance.

Diagnosis, Differential↗
PubMed1992

Coronary artery aneurysm formation following directional coronary atherectomy.

Directional coronary atherectomy has recently become available to treat coronary stenosis by excision and removal of tissue. The optimal depth of resection by this method has not been determined and complications have occurred. This report describes the formation of a coronary aneurysm at an atherectomy site in an asymptomatic patient, a finding not reported previously.

Angioplasty, Balloon, Coronary↗
PubMed1992

Computed tomography of gynecologic neoplasms.

Both CT and MR imaging have had a major impact on gynecologic oncologic imaging, and new technology and imaging techniques are still being introduced. CT maintains a role in gynecologic pelvic cancer imaging because of cost-effectiveness, high spatial resolution, fast examination time, and wide availability. CT is particularly advantageous for lymph node metastasis screening and guided-biopsy of metastases and recurrent tumor. CT currently is recommended for primary staging of ovarian cancer and advanced cancers of the cervix and endometrium, detection of persistent and metastatic gestational trophoblastic disease, and evaluation of recurrent gynecologic pelvic cancers.

Female↗
PubMed1991

The effect of dibutyryl camp (dBcAMP) on morphological differentiation, growth and invasion in vitro of a hamster brain-tumor cell line: a comparative study of dBcAMP effects in 2- and 3-dimensional cultures.

The use of agents that stimulate cancer cells to differentiate is proposed as a potential approach to the treatment of malignancy. To evaluate the effects of a differentiation inducer on morphology, growth and invasion in vitro of brain-tumor cells, a diffusely invasive hamster glial cell line (CxT3C15) was treated with ImM dibutyryl cyclic adenosine monophosphate (dBcAMP). The efficacy of dBcAMP was tested in monolayer cultures, 3-dimensional static cultures (i.e., spheroids) and confrontation cultures with an embryonic chick heart. CxT3C15 cells exhibited increased numbers of long cellular processes (morphological differentiation) following treatment of monolayer cultures with ImM dBcAMP. One mM dBcAMP also altered the macroscopic and ultrastructural morphology of CxT3C15 grown as spheroids. These alterations were: (i) a fast transition of rough to smooth morphology macroscopically, and (ii) fading of the cell borders concomitant with the disappearance of cell-membrane excrescences, as seen by scanning electron microscopy. Exponential growth of CxT3C15 in monolayers was not changed following treatment with ImM dBcAMP. Treatment of CxT3C15 spheroids with the same dose of dBcAMP caused a reduction of relative volume increase (30-40%). Invasion of CxT3C15 in an embryonic chick heart in vitro was not altered after addition (prior to or at the time of co-culture) of ImM dBcAMP to the co-cultures. These results indicate that invasion of CxT3C15 is not necessarily linked to morphological differentiation or moderated by reduced proliferation.

Animals↗
PubMed1991

Carotid and vertebral artery injury in survivors of atlanto-occipital dislocation: case reports and literature review.

Atlanto-occipital dislocation (AOD) usually results in immediate death from transection of the upper cervical spinal cord near the spinomedullary junction. However, over the last several decades increasing numbers of AOD survivors have been identified. Although many of these patients initially demonstrate profound neurologic deficits, a number who survive have regained most or all neurologic functions, indicating that they did not suffer mechanical disruption of the spinal cord at the time of AOD. In the survivors, a growing body of evidence indicates that many of the initial neurologic deficits are related to vascular injury to the carotid or vertebral arteries and their branches. We recently encountered three AOD survivors with no evidence of mechanical injury to the spinal cord in which angiography demonstrated vascular injury to the internal carotid artery in the form of vasospasm in one case and to the vertebral arteries in the forms of focal stenosis at the site of dural penetration, focal stenosis and distal vasospasm, and focal stenosis with distal intimal flap and dissection in one case each. Autopsy after one of the three died after cardiac arrest demonstrated diffuse infarction of the cerebrum, cerebellum, midbrain, brainstem, and upper cervical spinal cord without evidence of mechanical laceration or transection of the spinal cord. Recovery of neurologic function in two cases following prompt immobilization and angiography suggests that neurologic deficits secondary to vascular injury are potentially reversible.

Adolescent↗
PubMed1991

Split-thickness skin grafting of the myelomeningocele defect: a subset at risk for late ulceration.

The appropriate method and timing of the management of the myelomeningocele defect have prompted considerable discussion. Use of split-thickness skin grafts acutely has accomplished wound closure with low morbidity and mortality. This study was designed to address the question of long-term suitability of the technique of split-thickness skin grafting of the myelomeningocele patient. The incidence of late and/or severe skin ulceration and the presence of gibbus deformity were correlated with the method of skin closure. Long-term follow-up revealed a higher incidence of chronic skin ulceration in the split-thickness skin graft group as compared with the primary closure group. All skin breakdowns appeared in the presence of a gibbus deformity, and gibbus deformity was more prevalent in the split-thickness skin graft group. The incidence of skin ulceration and gibbus deformity was site-dependent. A thoracic or thoracolumbar myelomeningocele repair with split-thickness skin graft was significantly more likely to be complicated by skin problems than the defect in the lumbar, lumbosacral, or sacral region. This relationship was secondary to the frequency of gibbus deformity in the more cephalad defects than defects caudad. A treatment plan is outlined that is based on the primary variable of the location of the myelomeningocele and secondarily by defect size.

Chronic Disease↗
PubMed1991

Seat belt injuries: radiologic findings and clinical correlation.

The seat belt syndrome consists of skeletal, soft-tissue, and visceral injuries associated with use of two- and three-point restraints in patients involved in motor vehicle accidents. Skin abrasions of the neck, chest, and abdomen--the classic seat belt sign--indicate internal injury in 30% of cases. Neck abrasions are associated with injuries to the carotid artery, larynx, and cervical spine; chest abrasions, with fractures of the sternum, ribs, and clavicles and injuries to the heart and thoracic aorta; and abdominal abrasions, with mesenteric tears, bowel perforation and hematoma, Chance fractures, and injuries to the abdominal aorta. The seat belt sign should prompt a diligent search for related injuries.

Abdominal Injuries↗
PubMed1990

A randomized trial of surgery in the treatment of single metastases to the brain.

To assess the efficacy of surgical resection of brain metastases from extracranial primary cancer, we randomly assigned patients with a single brain metastasis to either surgical removal of the brain tumor followed by radiotherapy (surgical group) or needle biopsy and radiotherapy (radiation group). Forty-eight patients (25 in the surgical group and 23 in the radiation group) formed the study group; 6 other patients (11 percent) were excluded from the study because on biopsy their lesions proved to be either second primary tumors or inflammatory or infectious processes. Recurrence at the site of the original metastasis was less frequent in the surgical group than in the radiation group (5 of 25 [20 percent] vs. 12 of 23 [52 percent]; P less than 0.02). The overall length of survival was significantly longer in the surgical group (median, 40 weeks vs. 15 weeks in the radiation group; P less than 0.01), and the patients treated with surgery remained functionally independent longer (median, 38 weeks vs. 8 weeks in the radiation group; P less than 0.005). We conclude that patients with cancer and a single metastasis to the brain who receive treatment with surgical resection plus radiotherapy live longer, have fewer recurrences of cancer in the brain, and have a better quality of life than similar patients treated with radiotherapy alone.

Adult↗
PubMed1989

Urologic aspects of tethered cord.

Tethered cord syndrome, a form of spinal dysrhaphism, may involve vesical neurologic dysfunction. We present herein 60 cases of tethered cord syndrome, including 24 patients who underwent preoperative urodynamics studies. Preoperative cystometrography revealed areflexic bladders in 71 percent of cases and hyperreflexic bladders in 29 percent. Eight patients had serial pre- and postoperative urodynamics testing. Slight improvement was noted in postoperative urodynamics studies performed on 4 of 6 areflexic bladders and in the only hyperreflexic bladder studied. In addition, of the 3 patients in the serial urodynamics groups who had urinary symptoms preoperatively, 2 noted clinical improvement postoperatively. The urologist's role is important in the early detection, evaluation, and treatment of tethered cord syndrome and the neuropathic bladders that may result.

Adolescent↗
PubMed1989

Transfection of normal and transformed hamster cerebral cortex glial cells with activated c-H-ras-1 results in the acquisition of a diffusely invasive phenotype.

We have examined the effect of activated c-Ha-ras oncogene on the invasive phenotype of normal and tumorigenic glial cells of Syrian hamster cerebral cortex derivation. T24 ras oncogene derived from a human bladder carcinoma was transfected into normal glial cells and minimally invasive tumorigenic glial cells produced by SV40 transformation. The normal cells acquired the capacity to grow in soft agar and become tumorigenic. With ras transfection, both the normal and minimally invasive SV40 tumor cells became diffusely invasive for adjacent normal brain. (N.B.: One cell line exhibited less extensive invasion than the others.) All of the transfected cell lines exhibited high levels of ras expression. These results indicate that ras can impart tumorigenic potential to normal glial cells and progress these or minimally invasive glial cells to full invasiveness.

Animals↗