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Biomedical subjects

D C McCullough

Publications and source records attributed to D C McCullough.

At least 19 recordsLinked to original sources
PubMed1995

Teams in the workplace: the way to power them to productivity.

Teams! Teams! Teams! It seems you can't pick up a trade magazine or periodical without seeing something about team building. Once you get by the buzzwords and the acronyms, you have to wonder who's really doing it right. This article explains a proven process to build productive work teams. Teams that get bottom line results in the first 90 to 120 days. The author presents the five keys to assure successful work teams the very first time! In addition, you will learn five issues management must address, five skills every team member must master, five ways to help team members learn faster, and five tips to ensure a powered start to productivity.

Efficiency, Organizational↗
PubMed1992

Current prognosis in fetal ventriculomegaly.

A review of 51 cases referred for evaluation of fetal ventriculomegaly revealed adequate follow-up data in 40 patients. Three of the fetuses were electively aborted and 37 were delivered. There were no cases of death in utero. Of the 37 infants who were delivered, 26 (70%) were treated with shunt placement for neonatal hydrocephalus. The reasons for nontreatment included: inaccurate diagnosis, resolution of hydrocephalus by the time of delivery, neonatal death, and parental wishes. Survival time in the 26 shunt-treated patients ranged from 5 days to 14 years (average 4.25 years); five of these patients died within the first 2 weeks of life. Among the 26 treated patients, satisfactory cognitive ability was found in 10 (38%). Of the seven surviving nontreated infants, satisfactory cognitive ability was demonstrated in six (86%). Children with myelomeningocele displayed cognitive development similar to that in patients without myelomeningocele. The findings suggest that, of patients with in utero diagnosis of ventriculomegaly, approximately one-half survive (4-year average follow-up interval) and 38% of the survivors treated with shunt insertion have normal cognitive development. No subgroup likely to benefit from in utero treatment of ventriculomegaly was identified. Associated central nervous system or systemic malformations were identified in 26 (70%) of the 37 who came to delivery. This community-acquired series, not collected from a high-risk obstetrical-perinatal service, may reflect the general experience of the neurosurgeon consulting in such cases.

Abnormalities, Multiple↗
PubMed1990

Sudden onset of velopharyngeal insufficiency in Klippel-Feil syndrome.

A 17-year-old girl with Klippel-Feil vertebral anomalies presented with sudden onset of VPI and hoarseness after a minor neck torsion injury. Her symptoms were felt to be due to compression of the brain stem by the odontoid process (through basilar invagination). The VPI and hoarseness responded to conservative management with oral steroids.

Adolescent↗
PubMed1988

Unresectable gliomas in children: tumor-volume response to radiation therapy.

Serial tumor volume measurements were performed on computed tomographic (CT) scans or magnetic resonance (MR) images of 12 children treated with radiation therapy for high-grade (three children) or low-grade (nine children) astrocytomas of the optic nerve, thalamus, hypothalamus, cerebellar-pontine angle, and pons. Three types of initial tumor response were observed: Tumor volume increased in four children, remained unchanged in one, and decreased immediately after completion of radiation therapy in the others. High-grade tumors regressed maximally within 6 months and low-grade tumors within 10-25 months. All high-grade tumors recurred within 12 months. Three low-grade tumors recurred 3, 6 1/2, and 10 years after diagnosis, respectively. The tumor-volume halving time was 60-78 days for high-grade tumors and 108-330 days for low-grade tumors. The tumor doubling time was 48-60 days for high-grade tumors. The posttreatment increase in tumor volume has implications for radiation treatment planning. It did not indicate a poor prognosis.

Astrocytoma↗
PubMed1988

Fixed spinal cord: diagnosis with MR imaging.

Pulsatile motion of the spinal cord was examined with phase imaging techniques. Sagittal images of the spinal cord were obtained at different times of the cardiac cycle in healthy volunteers, as well as in patients in whom the spinal cord either was tethered, was compressed, or contained an intramedullary lesion. Pulsatile velocity changes of the spinal cord, observed on the phase images, were most marked at the cervical-upper thoracic level. Cord motion was found to be significantly decreased in cases in which the cord was either tethered or compressed. Cord enlargement due to an intramedullary lesion generally did not lead to decreased cord motion. Imaging of pulsatile cord motion may be clinically useful in evaluating diseases restricting cord motion or changing the status of parenchymal compliance.

Adult↗
PubMed1987

A review of the factors influencing the prognosis of medulloblastoma. The importance of cell differentiation.

The clinical, therapeutic, and histological features of 54 patients with medulloblastoma were analyzed retrospectively by a multivariate approach with regard to prognosis. The overall 5-year survival rate was 60%, with 48% of patients free of recurrence at 5 years. Cell differentiation, when present, was associated with a significantly longer recurrence-free period. Seventy-two percent of patients with the histological finding of cell differentiation were recurrence-free at 5 years. A marginally significant increase in the 5-year survival rate was also seen in association with differentiation. Only 34% of the patients whose tumor exhibited necrosis were alive at 5 years. There was no statistically significant difference in 5-year survival for children under 3 years of age or for the group of children aged 5 years or under. However, a significantly larger fraction (72%) of the group aged 5 years or under had a recurrence-free period of 5 years or more. Other factors including sex, extent of surgical resection. Chang tumor stage, posterior fossa radiation dose, and adjuvant chemotherapy did not influence prognosis.

Adolescent↗
PubMed1986

A history of the treatment of hydrocephalus.

At a time when the intrauterine diagnosis of hydrocephalus is commonplace and pioneering efforts of antenatal therapy are evolving, review of the chronology of treatment of this disorder becomes pertinent. The history of therapy of hydrocephalus may be divided into three phases. The first two largely involved accumulation of basic anatomical and pathophysiological information. The last phase dates only from the 1950s and may be considered an era of rapid technical development. This account discloses the obligatory relationship between useful therapy and basic knowledge.

Female↗
PubMed1986

Symptomatic progressive ventriculomegaly in hydrocephalics with patent shunts and antisiphon devices.

The antisiphon device (ASD) was designed to prevent excessive negative intracranial pressure and overdrainage with cerebrospinal fluid shunts. It has been recommended for prevention of slit ventricles and extreme shunt dependency. It was used by the author in 40 children and young adults who had low pressure headaches or were judged to be at risk for the development of subdural hematomas because of extreme hydrocephalus, relatively fixed head size, or tall stature. Nine patients encountered problems with adverse symptoms in spite of shunt patency. Four had alarming neurological symptoms of coma or severe headaches after incorporation of ASDs in ventriculoperitoneal shunt systems. With patients in the horizontal position, shunt patency was documented but computed tomography revealed progressive ventriculomegaly when they were kept erect. Symptoms abated and ventricular size diminished after conversion to proximal medium pressure diaphragm or spring-ball valve systems without ASDs. Because long shunt systems with ASDs require adequate hydrostatic columns to initiate flow when patients are erect, it is theorized that such symptoms could have been prevented by placing ASDs farther downstream from the cerebral ventricles.

Adolescent↗
PubMed1986

Perimesencephalic cistern obliteration: a CT sign of life-threatening shunt failure.

Death from cerebrospinal fluid shunt malfunction is a rare but tragic event. The authors describe seven children who when admitted were lethargic but arousable because of shunt failure. Sudden deterioration prompted unscheduled emergency shunt revision in each case. Two children subsequently died. Although neither the history nor the physical findings predicted this life-threatening shunt malfunction, obliteration of the perimesencephalic cistern was apparent on all preoperative computerized tomography (CT) scans. For reference, the scans of 43 other hydrocephalic children were drawn randomly from the hospital files and analyzed. It is concluded that CT evidence of obliteration of the perimesencephalic cistern is a useful warning of life-threatening shunt failure.

Adolescent↗
PubMed1985

Optic pathway tumors. A review with proposals for clinical staging.

Neoplasms of the optic nerves and pathways usually present during the first decade of life with loss of visual acuity. Neurofibromatosis is frequently associated with optic nerve tumors. Computed tomography has improved the capability of diagnosis, exact anatomic delineation of the mass, and clinical follow-up of afflicted patients. The tumors are typically slow-growing, low-grade astrocytomas. Posterior lesions involving the chiasm and hypothalamus may produce considerable morbidity and eventual mortality. Timing and appropriate methods of therapeutic intervention continue to be controversial. Symptomatic patients with blindness and involvement of a single optic nerve may be managed with surgical intervention alone. Posterior lesions with symptomatic progression should be treated with radiation therapy and with cerebrospinal fluid diversion when hydrocephalus occurs. Because these lesions evolve slowly, patients experience prolonged survival, and the benefits of radiation therapy are inconclusive. Clinical staging systems should consider both the functional status of patients and the anatomic extent of the disease.

Adolescent↗
PubMed1985

Surgical staging of cerebellar astrocytomas in childhood.

Benign cerebellar astrocytomas of childhood, when removed grossly in toto, have high cure rates and thus can be staged by their surgical resectability. Currently, total tumor resection is limited by attachment to or invasion of the tumor into the brain stem or by evidence of recurrence or metastases. Tumors of the cyst-nodule form are more often amenable to total gross removal because of their discrete margins and lateral placement, which is clear of brain stem structures. However, solid astrocytomas of the cerebellum, with or without visible cysts, may also be surgically cured if there is sufficient clearance from the brain stem. Patients with malignant astrocytomas of the cerebellum or metastases have much poorer prognoses. Preoperative and postoperative staging systems have been suggested based on these assumptions.

Astrocytoma↗
PubMed1982

Evolution of porencephalic cysts from intraparenchymal hemorrhage in neonates: sonographic evidence.

Ninety-four low-birth-weight neonates were screened consecutively with real-time sonography for evidence of cerebroventricular hemorrhage. Among them, 13 were found to have intraparenchymal hemorrhage beyond the area of the germinal matrix. Weekly follow-up sonograms revealed progression to porencephaly in every surviving infant. Four different sonographic patterns were observed during the evolution from the original hemorrhage to the porencephalic cyst. The size of the mature porencephalic cyst correlated directly with the size of the intraparenchymal hemorrhage. After ventriculoperitoneal shunting, the porencephalic cysts became smaller or remain unchanged. One small cyst was no longer identified after successful shunting, but reappeared with shunt failure.

Brain Diseases↗
PubMed1982

Current prognosis in overt neonatal hydrocephalus.

Chiefly because of advances in prenatal diagnostic ultrasonography, prognostic data on congenital hydrocephalus have increased in pertinence. Neurosurgeons may be confronted with requests for prognostic information after discovery of gestational hydrocephalus. Because previous reports reflect technical problems, complications, and less favorable results of an evolutionary period in hydrocephalus therapy, the authors have attempted to update the prognostic picture with a review of their results in hydrocephalus that is overt at birth. the status of 37 children treated with cerebrospinal fluid shunts after delivery at term with overt hydrocephalus was evaluated after an average 6-year follow-up period. They represented 8% of all children being followed for hydrocephalus. Outcome was also reviewed in 11 patients with severe hydrocephalus who were not treated. Of treated patients, 86% survived 1 to 16 years, while all of the untreated infants died at an average of 2.5 months. Approximately two-thirds of treated patients have normal or borderline intellectual capabilities (mean IQ 96, standard deviation 22). Dandy-Walker malformation was associated with a high mortality and a very low IQ in survivors. Congenital aqueductal atresia was also associated with intellectual impairment, but children with communicating hydrocephalus and myelomeningocele were not intellectually impaired. Among the survivors with low IQ, the poor outcome was generally predictable on the basis of cortical mantle thickness and "brain mass" calculations before therapy. The findings from this partially selected series indicate that the majority of babies born with overt hydrocephalus have a good prognosis with appropriate therapy.

Brain↗
PubMed1982

Cisplatin therapy in recurrent childhood brain tumors.

Twenty-two patients with brain tumors were initially treated with surgery, radiation therapy, and/or adjuvant chemotherapy. Histologic diagnosis included 11 gliomas, seven ependymomas, one dysgerminoma, one teratocarcinoma, one pinealoma, and one small cell tumor. At recurrence, documented on computerized tomographic scan, cisplatin (60 mg/m2/day iv X 2) was given every 3-4 weeks. Seventeen patients received two or more courses and were considered to be evaluable for response. Response parameters included change in the size of tumor on computerized tomographic scan and/or in clinical findings. Four patients had complete response, five had partial response, four had stable disease, and four had disease progression. Toxic effects were manageable. The number of patients with grade 3-4 toxic reactions, by category, were: thrombocytic, ten; leukocytic, four; renal, five; metabolic, four; gastrointestinal, none; and neurologic, seven. Two of the 14 patients tested had grade 3-4 ototoxicity. Acute fluid retention with decreased serum electrolytes and serious but reversible changes in the mental status, which were experienced in earlier patients, decreased in severity with increasing experience of the investigator. In summary, cisplatin appears to be active in a spectrum of brain tumors and should be studied further for therapeutic efficacy.

Adolescent↗