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Biomedical subjects

K Reed

Publications and source records attributed to K Reed.

At least 19 recordsLinked to original sources
PubMed1995

Pharmacokinetics of methylprednisolone during acute renal allograft rejection.

High dose methylprednisolone is administered empirically by fixed daily boluses to renal transplant recipients who are experiencing acute rejection episodes. Little information is available characterizing the pharmacokinetics of high-dose methylprednisolone in these individuals, who are often acutely ill. Therefore, 5 renal transplant recipients (2 men; 3 women) were studied during an acute rejection episode (mean serum creatinine = 2.6 +/- 0.7 mg/dl) which occurred within the first 8 months post-transplantation. The rejection episode was characterized clinically by at least two of the following: fever, leukocytosis, graft tenderness and an increase in serum creatinine. All patients received bolus doses of methylprednisolone for 3 consecutive days during the rejection episode. All patients were studied on the 3rd day of bolus dosing and received 250 mg methylprednisolone by an i.v. infusion. In phase II, 4 patients were studied during a period of stable renal function when the methylprednisolone was given at lower chronic immunosuppressive doses. Serum samples were taken prior to infusion and serially over the following 24 hours. The serum samples were analyzed for methylprednisolone with high-performance liquid chromatography (HPLC) and pharmacokinetic parametes were generated. During rejection episodes, the methylprednisolone clearance values were 523 +/- 154 ml/h/kg with a corresponding mean volume of distribution of 1.89 +/- 0.72 l/kg. The mean methylprednisolone half-life was 2.61 +/- 0.62 h. During Phase II, the methylprednisolone clearance was 358 +/- 95 ml/h/kg with a half-life of 3.05 h. This observation indicates that methylprednisolone metabolism is increased during acute rejection compared to that seen during chronic immunosuppressive dosing with this agent.

Acute Disease↗
PubMed1995

Perinatal regionalization versus hospital competition: the Hartford example.

OBJECTIVES: The increasingly competitive health care environment may undermine effective traditional regional organizations. It is urgent to document the benefits of perinatal regionalization for the emerging health care system. We present a case study that illustrates many of the challenges to and benefits of perinatal regionalization in the 1990s. BACKGROUND: The controversy in Hartford was sparked by a proposed merger of two major pediatric services into a full-service children's hospital. Community hospitals reacted with plans to upgrade their obstetrics/neonatal facilities toward level II (intermediate) or II+ (intensive) neonatal intensive care units (NICUs). The fear that unrestricted competition would drive up overall health care costs prompted the hospital association and Chamber of Commerce to retain consultants to evaluate the number and location of regional NICU beds. METHODS: The consultant team interviewed stake-holders in area hospitals, health maintenance organizations, insurance companies, businesses, state agencies, and community groups, and analyzed quantitative data on newborn discharges. RESULTS: The existing system worked remarkably well for clinical care, training, referrals, and provider and patient satisfaction. There was a high level of inter-hospital collaboration and regional leadership in obstetrics and pediatrics, but strong and growing competition between their hospitals. Hospital administrators enumerated the competitive threats that obligated them to compete and the financial disincentives to support the regional structures. Business leaders and insurance executives emphasized the need to control costs. Analysis of discharge data showed marginal adequacy of NICU beds but maldistribution between NICUs, particularly between level III and level II units. The consultants recommended no new beds based on population projections, declining lengths of stay nationally, and substantial gains available from aggressive back-transport of convalescing infants. The consultants emphasized the need for all stakeholders to support the regional infrastructure (referral, transport, education, evaluation, quality assurance) and to modify competition when it impaired effective regionalization. CONCLUSIONS: Regionalization permits better care at lower cost, yet competition may disrupt this effective system. Active cooperation by stakeholders is vital. Substantial new research is required to define optimal regional organization.

Bed Occupancy↗
PubMed1991

Cloning and expression of a rat cardiac delayed rectifier potassium channel.

We have cloned a cDNA (designated RAK) coding for a delayed-rectifier K current (IRAK) from adult rat heart atrium and expressed it in Xenopus oocytes. RAK differs from the cloned rat brain K current, BK2 [McKinnon, D. (1989) J. Biol. Chem. 264, 8230-8236], by one amino acid at residue 411. RAK expressed in oocytes compares closely to the intrinsic adult rat atrial delayed-rectifier current measured by using whole-cell recording of single isolated cells. Northern blot analysis confirmed the presence of the channel in adult rat atrium, and to a lesser extent, in rat ventricle. IRAK activates with time constants ranging from 58 ms at -20 mV to 6 ms at +60 mV and does not show significant inactivation over 800 ms. It is blocked by 4-aminopyridine greater than barium much greater than tetraethylammonium chloride, which is similar to the relative potencies of these blockers on the native delayed rectifier current. We conclude that the main delayed rectifier K current in adult rat atria is virtually identical to a neuronal delayed rectifier, BK2.

4-Aminopyridine↗
PubMed1991

Oral tocolysis with magnesium chloride: a randomized controlled prospective clinical trial.

A prospective randomized clinical trial was conducted to assess the efficacy and safety of enteric-coated magnesium chloride (SLOW MAG) as an oral tocolytic agent. Seventy-five patients between 24 and 34 weeks' gestation who were treated with intravenous magnesium sulfate for a first episode of preterm labor were enrolled. After a 12-hour contraction-free period on intravenous therapy, patients were randomized by sealed envelope to one of three groups: group 1, SLOW MAG (535 mg every 4 hours); group 2, oral ritodrine (20 mg every 4 hours); or group 3, no therapy (control). Patients receiving oral therapy were treated until delivery or completion of 36 weeks' gestation. No difference was found between groups with respect to time gained with the use of oral therapy or number completing 36 weeks' gestation. Therapy with enteric-coated magnesium chloride was associated with significantly fewer side effects (20%) as compared with ritodrine (48%) (p less than 0.01). Our results suggest that compared with ritodrine, enteric-coated magnesium chloride is as effective in prolonging pregnancy and preventing recurrent preterm labor. However, neither enteric-coated magnesium chloride nor ritodrine appeared to be any more effective in the prevention of preterm delivery than observation alone.

Administration, Oral↗
PubMed1991

The effect of glutathione monoethyl ester on the potentiation of the acute toxicity of methyl parathion, methyl paraoxon or fenitrothion by diethyl maleate in the mouse.

Depletion of hepatic glutathione in the mouse by pretreatment with diethyl maleate (DEM) is known to potentiate the acute toxicities of many dimethyl-substituted organothiophosphate insecticides. However, certain studies have raised doubts regarding the participation of glutathione in the detoxification of methyl parathion in the mouse, and hence the putative mechanism of action of DEM-induced potentiation of this insecticide. The present study evaluates the hypothesis that DEM potentiates the acute toxicities of methyl parathion, methyl paraoxon, and fenitrothion by a mechanism other than glutathione depletion. One hour following pretreatment of mice with DEM (0.75 ml/kg i.p.), glutathione was markedly depleted and the acute toxicities of methyl parathion, methyl paraoxon and fenitrothion were potentiated. Administration of glutathione monoethyl ester (20 mmol/kg p.o.) to DEM-pretreated mice attenuated DEM-depletion of hepatic glutathione, or maintained glutathione at or above control levels. However, glutathione monoethyl ester did not alter the DEM-induced potentiation of the lethality of these insecticides. Furthermore, administration of glutathione monoethyl ester to naive mice increased hepatic glutathione levels, but did not affect the percentage of animals succumbing to a challenge dose of methyl parathion, methyl paraoxon, or fenitrothion. These data indicate that DEM potentiates the toxicity of methyl parathion, methyl paraoxon or fenitrothion by a mechanism unrelated to hepatic glutathione content.

Animals↗
PubMed1991

A comparison of adinazolam and desipramine in the treatment of major depression.

Thirty-one patients with a DSM-III (R) diagnosis of Major Depression received adinazolam (n = 16) or desipramine (n = 15) during a 6 week double-blind randomized controlled trial. Both groups showed a significant decline in Hamilton Rating Scale for Depression scores (21.8 +/- 4.5 to 10.7 +/- 8.5 for adinazolam and 23.5 +/- 5.5 to 12.9 +/- 8.6) for desipramine. Melancholic and anxiety symptoms were reduced equally by both drugs. Initial sedation was the most common side-effect with adinazolam. Plasma levels of desipramine and hydroxy-desipramine correlated highly with oral dose after 3 weeks of treatment.

Adult↗
PubMed1991

Measles epidemic: impact on pediatric oncology patients.

Measles, a preventable disease, is again epidemic in the United States and is a threat to the immunocompromised pediatric oncology patient. In response to this latest epidemic, the Immunization Practices Advisory Committee has revised its recommendations for controlling an outbreak and has changed childhood immunization to a two-dose schedule. Full understanding of measles management is needed to effectively protect the pediatric oncology patient during the current epidemic. This article reviews the epidemiology, clinical presentation and management of measles, including recommendations for vaccinations, exposures, isolation, and patient and family education.

Child↗
PubMed1990

Influence of age and parity on the emotional care given to women experiencing miscarriages.

Obstetrical nurses (N = 309) participated in a study of the hypothetical influence of patients' age and parity status on nurses' emotional care for women who had experienced miscarriage. Vignettes in which age and parity were varied were mailed to the sample along with a questionnaire. After factor analysis, three measures of emotional care were used as the dependent variables: emotional seriousness, priority of care, and emotional support. Analysis of variance showed that the parity status of the woman was a significant variable in the nurses' perceptions of emotional seriousness and priority of care, but did not affect the nurses' perceptions of the need for emotional support. Age was not a significant variable in the three measures of emotional care.

Abortion, Spontaneous↗
PubMed1990

Prevalence of neuroleptic-induced dystonia in mania and schizophrenia.

In a prospective study of 41 acutely psychotic patients, neuroleptic-induced dystonic reactions occurred in 62.5% of the manic patients (10 of 16) and 66.7% of the schizophrenic patients (10 of 15), a nonsignificant difference. These findings contradict a recent report suggesting a higher risk for this side effect in mania.

Acute Disease↗
PubMed1989

Leiomyomas of the gastrointestinal tract.

Sixteen patients with leiomyoma of the gastrointestinal tract underwent operation and removal of their tumor during a four- and one-half-year period from January 1980 to July 1984. There were three esophageal, five gastric, two small bowel, four colon, and two anorectal leiomyomas. The majority of gastric leiomyomas presented with bleeding, as did half of the small bowel and colon cases. All were treated by excision without mortality. The various clinical presentations, evaluations, and choice of operative approach for this uncommon tumor are discussed.

Adult↗
PubMed1989

A prospective evaluation of the Port-A-Cath implantable venous access system in chronically ill adults and children.

Totally implantable venous access systems are presently widely used, but large-scale, prolonged studies are lacking in evaluating adequately these systems. We prospectively evaluated 198 systems in 191 patients (ages from two months to 80 years) during a three year period, with a median follow-up time of 330 days (a range of two to 1,088 days). Withdrawal of blood was consistently successful in 91 per cent of the systems. Complication rates for infection and thrombosis were 0.04 and 0.03 per 100 days of catheterization, respectively. No episodes of migration of the catheter or embolization were noted. This was thought to be the result of the placement of all catheters by a cutdown technique rather than percutaneously. Five systems were removed because of thrombosis and 22, because of infection. Implantable venous access devices are reliable and have a low complication rate in adult and pediatric patients who require repetitive venous access.

Adolescent↗
PubMed1988

Changes in plasma catecholamines and plasma renin activity during hypotension in conscious rats with lesions of the nucleus tractus solitarii.

The purpose of the present study was to examine the effects of lesions of the nucleus tractus solitarii on the reflex control of sympathetic activity and renin release in the conscious rat. Two doses of the arteriolar vasodilator hydralazine (0.3 and 1 mg/kg, i.v.) were used to activate reflexively the sympathetic nervous system in nucleus tractus solitarii lesion and control rats. Administration of 1 mg/kg of hydralazine to the control rats caused mean arterial pressure to fall from 120 +/- 2 mm Hg to 84 +/- 2 mm Hg and elicited an 11.2-fold increase in plasma renin activity and a 2.7-fold increase in plasma norepinephrine concentration. Administration of 0.3 mg/kg of hydralazine caused the arterial pressure of the lesion group to fall from 118 +/- 3 mm Hg to a comparable value of 85 +/- 4 mmg Hg, but plasma renin activity and plasma norepinephrine concentration did not rise significantly. However, administration of 1 mg/kg of hydralazine to the lesion group caused arterial pressure to fall from 128 +/- 6 mm Hg to 64 +/- 2 mm Hg, in association with a 12.4-fold increase in plasma renin activity and a 1.6-fold elevation in plasma norepinephrine concentration. Atenolol, a beta 1-adrenoceptor antagonist, blocked 70% of the rise in plasma renin activity caused by 1 mg/kg of hydralazine in both groups of rats. In addition, prior renal denervation also markedly attenuated the rise in plasma renin activity caused by hydralazine in the lesion group. Finally, electrical stimulation of the vagus nerves, which caused a large vasodepressor response in the control group, failed to lower the arterial pressure of the lesion group. Based on these observations, we conclude that in the conscious rat (1) nucleus tractus solitarii lesions eliminate the arterial baroreflexes as well as the cardiopulmonary baroreflex, and (2) severe hypotension induces sympathetically mediated renin release in the apparent absence of arterial and cardiopulmonary baroreflex function.

Animals↗
PubMed1988

Role of radionuclide imaging in the evaluation of wrist pain.

The cause of hand and wrist pain can be difficult to determine, especially when standard radiographs are normal or show only nonspecific changes. This study reports the effectiveness of radionuclide imaging in the evaluation of patients with hand and wrist pain of uncertain cause. Eighty-eight patients with hand and wrist pain and initially normal standard radiographs were evaluated prospectively by additional radiographic methods including the following: routine tomography, wrist arthrography, computerized tomography, or magnetic resonance imaging. Each patient also had bone scintigraphy. The diagnosis established by clinical assessment and by other imaging methods was then compared with the scintigraphic findings. The presence or absence of focal scintigraphic abnormalities correlated with the presence or absence of focal pathology definable by the conventional methods in 88% of patients. As expected, scintigraphy was chiefly of value in defining the locus of an injury or other process in the wrist, rather than the nature of an abnormality. The scintigrams were abnormal in 95% of cases involving complete intrinsic ligament ruptures and fractures and were normal in 96% of patients with no definable injury. Scintigraphic findings correlated poorly with partial intrinsic ligament injuries and in cases of synovitis. Radionuclide imaging is a sensitive means of detecting focal lesions in patients with hand and wrist pain of unknown cause.

Adult↗
PubMed1988

Rapid, inexpensive confirmation of chlamydial infection.

This article will hopefully make all optometrists aware of a rapid, direct method for confirming a diagnosis of chlamydial (inclusion) conjunctivitis. The Micro-Trak test from Syva is inexpensive, highly specific, and very sensitive for all human serovars of Chlamydia trachomatis. The current regimens for chlamydial conjunctivitis are also described.

Conjunctivitis, Inclusion↗