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Biomedical subjects

K A Greene

Publications and source records attributed to K A Greene.

33 records · Page 2Linked to original sources
PubMed1994

Cardiopulmonary bypass, hypothermic circulatory arrest and barbiturate cerebral protection for the treatment of giant vertebrobasilar aneurysms in children.

Intracranial aneurysms in the pediatric population are rare lesions with a significant proportion occurring as giant aneurysms involving the vertebrobasilar system. The complex anatomy of these lesions frequently creates an extremely difficult management dilemma. We present two patients, a 9-year-old and a 13-year-old, with giant fusiform vertebrobasilar aneurysms, to illustrate the utility of cardiopulmonary bypass, hypothermic circulatory arrest and barbiturate cerebral protection for successful surgical treatment of these complex intracranial vascular lesions in children.

Adolescent↗
PubMed1994

The effect of chronic alprazolam on sleep and bioamine metabolites in depression.

Alprazolam administered for 43 days in doses of 6 to 10 mg/day had an antidepressant effect in four of nine depressed patients. Decreases in slow wave sleep, increases in rapid eye movement (REM) latency, and decreases in REM minutes and percent and REM sleep eye movements were found in the group as a whole. The drug had a general hypnotic effect with a trend toward increased total sleep time. Nonsignificant changes in the concentrations of 3-methyl-4-hydroxyphenylglycol and homovanillic acid in the cerebrospinal fluid (CSF) were qualitatively similar to those found after treatment with tricyclic antidepressant drugs; however, only the larger decreases in CSF 5-hydroxyindoleacetic acid achieved statistical significance. Baseline sleep and CSF metabolites and changes in these measures on drug did not predict the therapeutic effects of alprazolam.

Adult↗
PubMed1994

Continuous venovenous hemodialysis.

Hemodialysis and peritoneal dialysis are the main renal replacement therapies for patients with acute renal failure. These patients are often unable to tolerate drastic fluid shifts and other complications of conventional dialysis. Continuous hemodialysis, however, provides protection from the hemodynamic consequences and osmotic stressors of conventional dialysis and is rapidly becoming the treatment of choice for critically ill patients. We present a case in which a patient with a spontaneous cerebellar hemorrhage developed acute renal failure. Surgical evacuation was not an option. Clinical management included the use of continuous venovenous hemodialysis, which is described in the setting of a patient with a posterior fossa mass. The risks of anticoagulation, hemodynamic instability, and development of dialysis disequilibrium syndrome are discussed.

Acute Kidney Injury↗
PubMed1993

Multicystic metastatic carcinoid to brain: case report.

Symptomatic intraparenchymal brain metastases from carcinoid tumors are unusual, and neurological deficits are rarely the first symptom of underlying carcinoid primaries. We report a patient with multiple cystic metastases to the brain from a lung primary who first presented with headaches and seizures. Serotonin was present within the fluid of the cystic cavities, and serum serotonin concentrations were normal. Magnetic resonance imaging of the brain revealed several metastases not present on the initial head computed tomography scan.

Aged↗
PubMed1993

Self-inflicted orbital and intracranial injury with a retained foreign body, associated with psychotic depression: case report and review.

Reports of intracranial self-mutilation by psychotic individuals are associated with severe mental disorders, criminality, or both. We describe a psychotically depressed male who drove a ballpoint pen through his right medial canthus and into his intracranial compartment. The patient developed a cavernous sinus syndrome and a traumatic dissection of the cavernous portion of the carotid artery. The pen was removed intraoperatively. Postoperatively, the patient was placed on a course of broad-spectrum antibiotics, antidepressants, and antipsychotic medications, and he has received long-term psychiatric follow-up. The literature related to these unusual cases is reviewed, and relevant surgical, medical, and psychiatric aspects of treatment are discussed.

Adult↗
PubMed1993

Injuries resulting from bungee-cord jumping.

A 19-year-old woman sustained a nonfatal hanging injury and a 28-year-old man sustained a unilateral locked facet with resultant quadriplegia as a result of bungee jumping. Injuries due to this sport have not been reported previously.

Adult↗
PubMed1993

Ventricular CSF shunt infections associated with Corynebacterium jeikeium: report of three cases and review.

Ventricular CSF shunt infections due to Corynebacterium jeikeium are rare. Such infections may become manifest weeks to months after surgery. They are difficult to eradicate and often recur. We report three cases of C. jeikeium ventricular CSF shunt infections, all of which occurred in patients who received long-term prophylactic therapy with antibiotics and had protracted hospitalizations. Two patients had multiple recurrences, and all patients required shunt revision. Additional therapy with intrathecal vancomycin for 6-10 days after surgery was effective for this unusual cause of ventricular CSF shunt infection. On the basis of our experience and a review of six previously published case reports, we recommend CSF sterilization with intravenous and intrathecal vancomycin, followed by replacement of shunt hardware.

Adult↗
PubMed1993

Giant serpentine middle cerebral artery aneurysm treated by extracranial-intracranial bypass. Case report.

Giant intracranial aneurysms often pose difficult management issues. Such aneurysms may not be amenable to direct surgical attack because of their size, location, or lack of a clear aneurysmal neck. In such cases, a combination of strategies may provide a means of proximal aneurysm occlusion and distal cerebral revascularization. The authors report the successful treatment of a giant (186.8-ml) serpentine aneurysm of the left middle cerebral artery (MCA) in a 14-year-old boy. The aneurysm was managed in a two-stage procedure in which the MCA branches distal to the aneurysm were anastomosed first with branches of the left superficial temporal artery. After the bypass procedure, direct occlusion of the MCA was performed at the proximal base of the aneurysm at its site of dilatation. The patient had no intraoperative or postoperative complications and was intact neurologically 6 months following the procedures.

Adolescent↗
PubMed1991

Preoperative nutritional status of total joint patients. Relationship to postoperative wound complications.

The records of 217 consecutive patients who underwent a primary total hip or total knee arthroplasty were reviewed for preoperative and postoperative nutritional status. Fifty-seven patients had a lymphocyte count of less than 1,500 cells/mm3, four patients had an albumin level of less than 3.5 g/dL, and two patients had both, giving a 27% incidence of indices indicative of preoperative nutritional depletion. Patients without wound complications had an average preoperative lymphocyte count of 1,995 (+/- 631), compared to 1,638 (+/- 491) for those with persistent serous drainage from their wounds, and 1,553 (+/- 419) for those patients with a major wound complication (P = .002). The average albumin levels were 4.30 (+/- 0.33), 4.22 (+/- 0.31), and 4.13 (+/- 0.54), respectively. Patients with rheumatoid arthritis were compared to those with osteoarthritis and were found to have significantly lower preoperative albumin levels. They were three times as likely to develop a major wound complication. Patients on immunosuppressive medications had significantly lower preoperative lymphocyte counts, lower albumin levels, and higher complication rates (P = .04). After operation, lymphocyte counts of all patients dropped to an average of 57% of their preoperative values, and albumin levels dropped to 72% of their preoperative values. No nutritional parameters had returned to their preoperative levels by 10 postoperative days. For all patients, a preoperative lymphocyte count of less than 1,500 cells/mm was associated with a five times greater frequency of developing a major wound complication, and an albumin level of less than 3.5 g/dL had a seven times greater frequency.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Passage of MHPG from plasma to CSF in a non-human primate.

In experimental protocols with humans and non-human primates, cerebrospinal fluid (CSF) concentrations of 3-methoxy-4-hydroxyphenylethylene glycol (MHPG), the predominant end-product of norepinephrine metabolism in the mammalian central nervous system (CNS), have been widely used as an index of the rate of CNS norepinephrine metabolism. However, an earlier investigation showed that there was slow but free exchange between plasma and CSF MHPG. To define more precisely the time-course of equilibration of plasma and CSF MHPG, we intravenously administered 100 micrograms/kg of [2H3]-MHPG to drug-naive squirrel monkeys. Measurements were made of the concentrations of [2H3]- and [1H]-MHPG in plasma and cervical CSF samples collected at time points from 10 min to 4 hr thereafter. The results indicated that neither plasma nor CSF concentrations of [1H]-MHPG changed during the course of the experiment, and that [2H3]-MHPG appeared in the CSF within 10 min of intravenous administration. The maximal plasma and CSF concentrations of [2H3]-MHPG were 7.6- and 2.3-fold higher than the respective concentrations of [1H]-MHPG. The plasma and CSF pools of [2H3]-MHPG reached concentration equilibrium within 30 min, and thereafter the temporal decline in concentration of [2H3]-MHPG was the same in plasma and CSF. These results demonstrate that MHPG rapidly crosses from plasma to CSF, and support the suggestion that this factor be included in any attempts to estimate norepinephrine turnover in the CNS from measurements of steady-state MHPG concentrations in CSF or plasma.

Animals↗
PubMed1990

Fatal postoperative Legionella pneumonia in a newborn.

This is a case of postoperative Legionella pneumonia in a full-term infant with hypoplastic left heart syndrome. The infant had an uncomplicated prenatal history, normal vaginal delivery, Apgars of 8 at 1 and 5 minutes, but was cyanotic at birth. At 3 days of age she had a stage 1 Norwood surgical procedure to palliate her congenital heart disease. A synthetic patch was placed over the thoracic midline because of difficulty in reapposing the sternum. Peritoneal dialysis was used to manage renal failure. At 20 days of age she had disseminated intravascular coagulopathy and pneumonia associated with sepsis. Four days later she died. Legionella pneumophila serogroup 1 was isolated from a lung culture taken at autopsy.

Adult↗
PubMed1989

Relationship between plasma and cerebrospinal fluid norepinephrine and dopamine metabolites in a nonhuman primate.

Major and minor pathways of metabolism in the mammalian CNS result in the formation of 3-methoxy-4-hydroxyphenylethylene glycol (MHPG) and normetanephrine (NMN) from norepinephrine (NE), and homovanillic acid (HVA) and 3-methoxytyramine (3-MT) from dopamine (DA), respectively. The correlational relationships between HVA and 3-MT and between MHPG and NMN in primate CSF and plasma have not been described. These relationships may help to elucidate the usefulness of CSF and plasma metabolites as indices of CNS NE and DA activity. In addition, because NMN is unlikely to cross the blood-brain barrier. CSF NMN concentrations would not be confounded by contributions from plasma, which is a major issue with CSF MHPG. We have obtained repeated samples of plasma and CSF from drug-naive male squirrel monkeys and have measured the concentrations of MHPG, HVA, NMN, and 3-MT to define their correlational relationships. For the NE metabolites, significant correlations were obtained for CSF MHPG and NMN (r = 0.806, p less than 0.001), plasma MHPG and CSF NMN (r = 0.753, p less than 0.001), and plasma and CSF MHPG (r = 0.776, p less than 0.001). These results suggest that CSF and plasma MHPG and CSF NMN may reflect gross changes in whole brain steady-state noradrenergic metabolism. Only a single significant relationship was demonstrated for the DA metabolites, with CSF 3-MT correlating with plasma HVA (r = 0.301, p less than 0.025). The results for the DA metabolites probably reflect regional differences in steady-state brain dopaminergic metabolism.

Animals↗
PubMed1988

Measurement of phenylacetic acid in cerebrospinal fluid and plasma using combined gas chromatography/electron capture chemical ionization mass spectrometry.

Details are presented of an ultra-sensitive gas chromatographic/mass spectrometric assay for phenylacetic acid in plasma and cerebrospinal fluid based on measurements of the relative intensities of the carboxylate anions, derived from the penta- and tetrafluorobenzyl esters under electron capture chemical ionization conditions, of unlabeled and a (13C2)-labeled internal standard. The limits of detection for the penta- and tetrafluorobenzyl esters are 0.85 and 4.0 pg respectively, and the assay is capable of measuring phenylacetic acid concentrations in samples as small as 20 microliter of CSF and plasma. The penta- and tetrafluorobenzyl esters are chromatographically separated on the gas chromatograph column, which allows for their co-injection and independent measurement from the same chromatogram.

Animals↗