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PubMed2003

6-Thioguanine, cytarabine, and daunorubicin (TAD) and high-dose cytarabine and mitoxantrone (HAM) for induction, TAD for consolidation, and either prolonged maintenance by reduced monthly TAD or TAD-HAM-TAD and one course of intensive consolidation by sequential HAM in adult patients at all ages with de novo acute myeloid leukemia (AML): a randomized trial of the German AML Cooperative Group.

PURPOSE: To examine the efficacy of prolonged maintenance chemotherapy versus intensified consolidation therapy for patients with acute myeloid leukemia (AML). MATERIALS AND METHODS: Eight hundred thirty-two patients (median age, 54 years; range, 16 to 82 years) with de novo AML were randomly assigned to receive 6-thioguanine, cytarabine, and daunorubicin (TAD) plus cytarabine and mitoxantrone (HAM; cytarabine 3 g/m2 [age < 60 years] or 1 g/m2 [age > or = 60 years] x 6) induction, TAD consolidation, and monthly modified TAD maintenance for 3 years, or TAD-HAM-TAD and one course of intensive consolidation with sequential HAM (S-HAM) with cytarabine 1 g/m2 (age < 60 years) or 0.5 g/m2 (age > or = 60 years) x 8 instead of maintenance. RESULTS: A total of 69.2% patients went into complete remission (CR). Median relapse-free survival (RFS) was 19 months for patients on the maintenance arm, with 31.4% of patients relapse-free at 5 years, versus 12 months for patients on the S-HAM arm, with 24.7% of patients relapse-free at 5 years (P =.0118). RFS from maintenance was superior in patients with poor risk by unfavorable karyotype, age > or = 60 years, lactate dehydrogenase level greater than 700 U/L, or day 16 bone marrow blasts greater than 40% (P =.0061) but not in patients with good risk by complete absence of any poor risk factors. Although a survival benefit in the CR patients is not significant (P =.085), more surviving patients in the maintenance than in the S-HAM arm remain in first CR (P =.026). CONCLUSION: We conclude that TAD-HAM-TAD-maintenance first-line treatment has a higher curative potential than TAD-HAM-TAD-S-HAM and improves prognosis even among patients with poor prognosis.

Adolescent↗
PubMed2005

Maximizing therapeutic benefit of rituximab: maintenance therapy versus re-treatment at progression in patients with indolent non-Hodgkin's lymphoma--a randomized phase II trial of the Minnie Pearl Cancer Research Network.

PURPOSE: To compare the benefit of maintenance rituximab therapy versus rituximab re-treatment at progression in patients with previously treated indolent non-Hodgkin's lymphoma. PATIENTS AND METHODS: Between June 1998 and August 2002, 114 patients who had received previous chemotherapy for indolent non-Hodgkin's lymphoma were treated with a standard 4-week course of rituximab. Patients with objective response or stable disease were randomly assigned to receive either maintenance rituximab therapy (standard 4-week courses administered at 6-month intervals) or rituximab re-treatment at the time of lymphoma progression. The duration of rituximab benefit was measured from the date of first rituximab treatment until the date other treatment was required. RESULTS: Ninety (79%) of 114 patients had objective response or stable disease after initial rituximab treatment, and were randomly assigned to treatment. Progression-free survival was prolonged in the maintenance group (31.3 v 7.4 months; P = .007). Final overall and complete response rates were higher in the maintenance group. Duration of rituximab benefit was similar in the maintenance and re-treatment groups (31.3 v 27.4 months, respectively). More maintenance patients remain in continuous remission, and more are currently in complete remission. Both treatment approaches were well tolerated. CONCLUSION: In patients who have objective response or stable disease with single-agent rituximab therapy, duration of rituximab benefit is substantially prolonged with either scheduled maintenance treatment or rituximab re-treatment at the time of progression. At present, the magnitude of benefit with either approach appears similar. However, additional follow-up of this trial is required, and completion of phase III randomized trials is necessary to definitively answer this question.

Adult↗
PubMed2004

Is there a link between telomere maintenance and radiosensitivity?

Several recent studies point to the possibility that telomere maintenance may constitute a potential genetic marker of radiosensitivity. For example, the human diseases ataxia telangiectasia and Nijmegen breakage syndrome, which are characterized by clinical radiosensitivity, show alterations in telomere maintenance. In addition, Fanconi's anemia patients, who are characterized by mild cellular radiosensitivity and in some cases marked clinical radiosensitivity, have altered telomere maintenance. Similarly, a correlation between telomere maintenance and cellular radiosensitivity was reported in a group of breast cancer patients. Another study demonstrated that radiosensitivity may be more pronounced in human fibroblasts with short telomeres than in their counterparts with long telomeres. Several mouse models including mice deficient in Ku, DNA-PKcs (Prkdc), Parp and Atm, all of which are radiosensitive in vivo, show clear telomere alterations. The link between telomere maintenance and radiosensitivity is also apparent in mice genetically engineered to have dysfunctional telomeres. Finally, studies using non-mammalian model systems such as C. elegans and yeast point to the link between radiosensitivity and telomere maintenance. These results warrant further investigation to identify the extent to which these two phenotypes, namely radiosensitivity and telomere maintenance, are linked.

Animals↗
PubMed2000

HIV transmission and the cost-effectiveness of methadone maintenance.

OBJECTIVES: This study determined the cost-effectiveness of expanding methadone maintenance treatment for heroin addiction, particularly its effect on the HIV epidemic. METHODS: We developed a dynamic epidemic model to study the effects of increased methadone maintenance capacity on health care costs and survival, measured as quality-adjusted life-years (QALYs). We considered communities with HIV prevalence among injection drug users of 5% and 40%. RESULTS: Additional methadone maintenance capacity costs $8200 per QALY gained in the high-prevalence community and $10,900 per QALY gained in the low-prevalence community. More than half of the benefits are gained by individuals who do not inject drugs. Even if the benefits realized by treated and untreated injection drug users are ignored, methadone maintenance expansion costs between $14,100 and $15,200 per QALY gained. Additional capacity remains cost-effective even if it is twice as expensive and half as effective as current methadone maintenance slots. CONCLUSIONS: Expansion of methadone maintenance is cost-effective on the basis of commonly accepted criteria for medical interventions. Barriers to methadone maintenance deny injection drug users access to a cost-effective intervention that generates significant health benefits for the general population.

Adult↗
PubMed2003

Treatment options for initial maintenance therapy of persistent asthma: a review of inhaled corticosteroids and leukotriene receptor antagonists.

Inhaled corticosteroids (ICSs) are recognized as the cornerstone of asthma therapy. They are considered to be the most effective anti-inflammatory medication currently available for the treatment of persistent asthma, regardless of its severity. Leukotriene receptor antagonists (LTRAs) are also used as initial maintenance therapy in patients whose asthma is uncontrolled by bronchodilators alone. There are now sufficient data available to allow a comparison of the relative effectiveness and cost-effectiveness of LTRAs and ICSs as initial maintenance therapy. The consensus from the studies reviewed in this article demonstrates that ICSs are more effective than LTRAs as initial maintenance therapy. In particular, studies on fluticasone propionate have shown that it was more effective than LTRAs in clinical outcomes: producing greater improvements in lung function and asthma control; as measured by either forced expiratory volume in 1 second (FEV1) or peak expiratory flow (PEF); by a greater reduction in daytime and night-time asthma symptoms; and short-acting beta2-agonist use. This superiority was also seen when patients were switched from an LTRA to fluticasone propionate. Similar findings have been demonstrated with beclomethasone dipropionate (BDP), showing that, in adults, this inhaled steroid also had a greater effect on pulmonary function and symptom scores than did LTRAs. Quality of life assessments showed that fluticasone propionate achieved improvements that were deemed to be clinically meaningful; these changes were significantly greater than those achieved with LTRAs. However, questionnaire-based patient preference studies comparing BDP with LTRAs showed that children and adolescents generally preferred an LTRA to BDP. A number of comparative analyses showed that inhaled fluticasone propionate is more cost-effective than either montelukast or zafirlukast; these analyses used cost per symptom-free day and cost per successfully treated patient as outcome measures, from the perspective of a third-party payer. In general, these results were supported by resource utilisation studies in real-world settings. Asthma treatment guidelines (e.g. GINA, 2002) recommend combination therapy with ICSs and a long-acting beta2-agonist as initial maintenance therapy if the disease is of sufficient severity. Studies that assessed the effectiveness, cost-effectiveness, and quality of life achieved with a salmeterol fluticasone propionate combination as initial maintenance therapy also showed it to be superior to LTRAs. In conclusion, in terms of efficacy and quality of life, fluticasone propionate is more effective than LTRAs as initial maintenance therapy and is associated with significantly lower healthcare costs and less frequent use of healthcare resources than LTRAs. There is also evidence to suggest that initial maintenance therapy with the combination of an inhaled steroid plus a long-acting beta-agonist bronchodilator may be a more effective option for the management of persistent asthma than treatment with a single-controller agent alone (ICS or LTRA).

Administration, Inhalation↗
PubMed1991

Maintenance requirements of beef cattle as affected by season on different planes of nutrition.

Eight Hereford steers with an initial weight of 344 kg and a final weight of 476 kg were allotted randomly to two groups that were alternated between low (120 x maintenance) and high (2.27 x maintenance) intakes during five consecutive seasons in order to measure effects of season (cold stress) and intake on thermoneutral energy requirements. The steers were housed outdoors with neither shelter nor bedding and adapted to the specified intake levels for 21 to 31 d before each season's measurement of maintenance. Maintenance energy requirements were estimated as fasting heat production (FHP) and maintenance metabolized energy (MEm) by respiration calorimetry at thermoneutral temperatures. The high plane of nutrition caused a consistent increase of about 7% in FHP and 14% in MEm averaged across seasons (P less than .05). Within plane of nutrition, season had no effect on FHP or MEm, with the exception that values recorded in fall were lower than those recorded during the first summer (P less than .05). Nevertheless, daily gain during the winter acclimatization period was lower (P less than .05). We conclude that season had no effect on thermoneutral maintenance energy requirements (FHP, MEm) even though cold increased requirements for weight maintenance or gain. No interactions were found between season and plane of nutrition for the parameters measured. Acute cold stress, rather than chronically elevated metabolic rate, likely was responsible for poorer feedlot performance during the cold months of the year.

Animal Nutritional Physiological Phenomena↗
PubMed2003

A dynamic model of metabolizable energy utilization in growing and mature cattle. I. Metabolizable energy utilization for maintenance and support metabolism.

Models to predict heat production attributable to maintenance and support metabolism in growing and mature cattle were developed on the basis of three concepts. The first concept is that animals fed fixed amounts of the same diet achieve weight equilibrium over an extended feeding period, and that the ME consumed at weight equilibrium is the maintenance requirement. The second concept is that a part of the heat production resulting from ME consumed above the maintenance requirement is associated with an elevation of vital functions (support metabolism), and this heat production can be modeled as a function of the level of feeding. The third concept is that previous levels of nutrition affect current estimates of heat production, and that this impact can be modeled as a delayed response in heat production associated with support metabolism. Experimental data on feed consumption showed that maintenance requirements varied in simple proportion to BW, not only for different breeds of mature cattle at BW equilibrium, but also for calves and growing steers held at BW stasis. Experimental data in which different breeds of cattle achieved weight equilibrium when fed fixed amounts of a specific diet were used to estimate breed parameters associated with maintenance for 21 breeds of cattle and 15 biological types of crossbred cattle. Level of feeding was estimated as a multiple of the maintenance intake and used to model heat production associated with support metabolism. Other experimental data on growing cattle were used to estimate breed parameters for predicting heat production associated with support metabolism for 21 breeds of cattle and 15 biological types of crossbred cattle. A distributed lag function was used to model the delayed response in heat production associated with support metabolism with changes in plane of nutrition. The models were tested by simulating experimental data for three breeds of weaned steers finished on high-energy diets. Results for the total heat production associated with maintenance and support metabolism expressed on a unit BW basis showed a similar response with stage of maturity when compared with other experimental data.

Animal Feed↗
PubMed2006

Energy and protein requirements for maintenance and growth of Boer crossbred kids.

Meat production by goats has become an important livestock enterprise in several parts of the world. Nonetheless, energy and protein requirements of meat goats have not been defined thoroughly. The objective of this study was to determine the energy and protein requirements for maintenance and growth of 34 (3/4) Boer x (1/4) Saanen crossbred, intact male kids (20.5 +/- 0.24 kg of initial BW). The baseline group was 7 randomly selected kids, averaging 21.2 +/- 0.36 kg of BW. An intermediate group consisted of 6 randomly selected kids, fed for ad libitum intake, that were slaughtered when they reached an average BW of 28.2 +/- 0.39 kg. The remaining kids (n = 21) were allocated randomly on d 0 to 3 levels of DMI (treatments were ad libitum or restricted to 70 or 40% of the ad libitum intake) within 7 slaughter groups. A slaughter group contained 1 kid from each treatment, and kids were slaughtered when the ad libitum treatment kid reached 35 kg of BW. Individual body components (head plus feet, hide, internal organs plus blood, and carcass) were weighed, ground, mixed, and subsampled for chemical analyses. Initial body composition was determined using equations developed from the composition of the baseline kids. The calculated daily maintenance requirement for NE was 77.3 +/- 1.05 kcal/kg(0.75) of empty BW (EBW) or 67.4 +/- 1.04 kcal/kg(0.75) of shrunk BW. The daily ME requirement for maintenance (118.1 kcal/kg(0.75) of EBW or 103.0 kcal/kg(0.75) of shrunk BW) was calculated by iteration, assuming that the heat produced was equal to the ME intake at maintenance. The partial efficiency of use of ME for NE below maintenance was 0.65. A value of 2.44 +/- 0.4 g of net protein/kg(0.75) of EBW for daily maintenance was determined. Net energy requirements for growth ranged from 2.55 to 3.0 Mcal/kg of EBW gain at 20 and 35 kg of BW, and net protein requirements for growth ranged from 178.8 to 185.2 g/kg of EBW gain. These results suggest that NE and net protein requirements for growing meat goats exceed the requirements previously published for dairy goats. Moreover, results from this study suggest that the N requirement for maintenance for growing goats is greater than the established recommendations.

Animal Feed↗
PubMed2006

Escitalopram maintenance treatment for prevention of recurrent depression: a randomized, placebo-controlled trial.

BACKGROUND: Major depressive disorder is a recurrent illness that often requires maintenance antidepressant treatment. Escitalopram is a selective serotonin reuptake inhibitor (SSRI) that has shown efficacy in both acute and continuation treatment of major depressive disorder. The current trial examined the efficacy of maintenance escitalopram treatment in preventing depression recurrence in patients who responded to acute SSRI therapy. METHOD: Patients with recurrent DSM-IV-defined major depressive disorder (>or= 2 previous episodes; baseline Montgomery-Asberg Depression Rating Scale [MADRS] score >or= 22) who had responded (MADRS score or= 22 or insufficient therapeutic response during the double-blind phase. The study was conducted between October 16, 2000, and February 4, 2003. RESULTS: A total of 234 patients who responded to acute open-label treatment with 1 of 4 SSRIs received at least 1 dose of open-label escitalopram continuation treatment. Of 164 patients who completed escitalopram continuation treatment, 139 were randomly assigned to double-blind maintenance treatment with escitalopram (N = 73) or placebo (N = 66). Mean baseline MADRS scores at the start of the maintenance phase were < 5 for both the placebo- and escitalopram-treatment groups. Time to recurrence was significantly longer in patients who received maintenance treatment with escitalopram compared with patients switched to placebo (hazard ratio = 0.26, 95% CI = 0.13 to 0.52, p < .001). Long-term escitalopram treatment was well tolerated. CONCLUSION: Maintenance treatment with escitalopram was well tolerated and significantly reduced the risk for recurrence of depression. Patients with few residual symptoms following continuation treatment with escitalopram experienced a high rate of depression recurrence when switched to placebo, demonstrating the need for maintenance therapy of recurrent major depressive disorder beyond 4 to 6 months of initial symptom resolution even if few residual symptoms are present.

Adult↗
PubMed2003

An individualized, adjustable maintenance regimen of budesonide/formoterol provides effective asthma symptom control at a lower overall dose than fixed dosing.

PRINCIPLES: Current asthma management employing inhaled corticosteroids (ICS) and longacting b2-agonists (LABA) aims to rapidly achieve and then maintain overall asthma control including symptoms with minimal medication. This study compared self-guided adjustable maintenance dosing with budesonide/formoterol in a single inhaler with fixed dosing. METHODS: In an open-label, parallel-group, multicentre study, 127 asthmatic patients, well controlled on ICS and LABA, were treated with budesonide/formoterol (Symbicort) Turbuhaler) 200/6 mg (equivalent to 160/4.5 mg delivered dose) 2 inhalations bid for 4 weeks, and were then randomised to budesonide/formoterol adjustable dosing (n = 69) (guided self-adjustment of dose: 1 inhalation bid or 2 inhalations at night with interim step ups to 2 inhalations bid and if not sufficient up to 4 inhalations bid for 14 days) or fixed dosing (2 inhalations bid) (n = 58) for 12 weeks. RESULTS: Patients used adjustable dosing effectively; >50% used a decreased maintenance dose on >50% of the days. Seventy-two percent (50/69) from the adjustable-dosing group reduced their maintenance dose within the first 2 treatment weeks. Thirteen adjustable-dose patients (18.8%) never reduced their dose and 4 (5.8%) stepped up their dose. Symptom severity (NHLBI severity grade) decreased in both groups; however, the decrease was only statistically significant (p = 0.004) in the adjustable-dosing group. Treatment failures occurred in 17% and 24% of patients (adjustable and fixed dosing, respectively p = 0.35). Nocturnal awakenings (0.057 vs. 0.067/night, p = 0.006) and rescue medication use (0.15 vs. 0.23 inhalations/day, p <0.0001) were significantly less frequent with adjustable dosing, and the average daily medication dose was significantly reduced (3.0 vs. 3.9, p <0.0001) compared with fixed dosing. Lung function measurements (FEV1 and PEF) were not significantly different between groups during the study. There were no asthma-related hospital admissions. CONCLUSION: Asthma patients on adjustable maintenance dosing with budesonide/ formoterol maintained control of symptoms using significantly less medication overall than fixed dosing. Thus, adjustable maintenance dosing achieved guideline goals of effective asthma control at an appropriately low maintenance dose. However, larger studies on adjustable maintenance dosing are needed.

Adolescent↗
PubMedDate not supplied

Variables affecting the competency maintenance behaviors of occupational therapists.

OBJECTIVE: The purpose of this study was to examine the relationship between work environment and the competency maintenance activities of occupational therapists. METHOD: A survey of 121 occupational therapists in three states and interviews with 8 occupational therapists in Ohio were used. RESULTS: Analysis of survey data indicated that workplace support and the degree of competency monitoring are significant determinants of competency maintenance behavior. State continuing education requirements had no impact on reported levels of competency maintenance. Personal motivation of the therapist emerged as a potentially important moderator of the relationship between environment and competency maintenance. CONCLUSIONS: Although environmental factors enhance competency maintenance activities, active participation in competency maintenance is also related to the personal commitment of the individual therapist. Strategies that reduce barriers to effective competency maintenance and promote a culture of continuing competency in the profession merit further investigation.

Adult↗
PubMed1999

Induction and maintenance treatment regimens for HIV-1 infection in vitro.

Can aggressive anti-human immunodeficiency virus (HIV) induction regimens be simplified after sufficient virus suppression is achieved? In vitro studies were conducted to evaluate the hypothesis that aggressive induction regimens could be followed by less aggressive maintenance regimens. A clinical HIV-1 isolate and lymphoblastoid cell line (H9) were employed. Virus multiplicities were varied, as were drug inhibitory concentrations (IC90, IC99) and induction periods (1, 2 and 3 weeks) of a three-drug regimen (zidovudine plus lamivudine and indinavir), following which maintenance regimens (no drug, zidovudine alone, indinavir alone, zidovudine plus lamivudine) were employed. After 1 week inductions at IC99 concentrations, viral rebound occurred on none or one-drug maintenance regimens but not on a two-drug regimen. After 2 week inductions, viral rebound occurred with no-drug maintenance, but not with one- and two-drug regimens. After 3 week inductions, viral rebound did not occur in zero-, one-, or two-drug maintenance regimens, although HIV-1 DNA persisted in cultured cells. These studies suggest that although some induction-maintenance regimens will fail, after a sufficient period of HIV-1 suppression with a three-drug antiretroviral regimen, maintenance on fewer drugs may be feasible.

Anti-HIV Agents↗
PubMedDate not supplied

The prosthodontic maintenance requirements of mandibular mucosa- and implant-supported overdentures: a review of the literature.

PURPOSE: This article presents a critical review of the literature on the prosthodontic maintenance requirements of mandibular mucosa- and implant-supported overdentures. MATERIALS AND METHODS: A search of the literature produced 35 papers pertaining to prospective and retrospective studies. The relationship of these prosthodontic maintenance requirements to the axis of rotation treatment concept was examined. RESULTS: More often than not, 2 anterior mandibular implants either splinted (round or ovoid bars) or unsplinted (balls or magnets) have been used to evaluate this prosthodontic follow-up. Wide variation existed in the categories used for prosthodontic complications. Although principally related to alterations of overdenture contour and aspects of patrix and matrix maintenance, they also provide subjective information on relines and the rationale for avoiding overdenture fractures. These prosthodontic maintenance requirements undoubtedly have a direct impact on the time to retreatment of mandibular mucosa- and implant-supported overdentures. CONCLUSION: There appears to be a need for a more uniform, standardized categorization with criteria for determining prosthodontic success, in terms of maintenance requirements and complications, for mandibular mucosa- and implant-supported overdentures. Controlled prospective evaluations of exact prosthodontic maintenance requirements of mandibular overdentures using different systems are lacking and encouraged. There is also an absence of prospective studies on such maintenance requirements of mandibular overdentures using multiple round bars on 3 or 4 implants.

Dental Abutments↗
PubMed2005

A decrease of enlarged left atrium following cardioversion of atrial fibrillation predicts the long-term maintenance of sinus rhythm.

BACKGROUND: Although increased left atrial size (LA) has been long regarded as one of the factors negatively influencing the long-term maintenance of sinus rhythm (SR) following cardioversion (CV) of atrial fibrillation (AF), some reports suggested that CV might be effective also in patients with large LA.Aim. We sought to determine the role of LA enlargement in long-term SR maintenance after CV of persistent AF. METHODS: 104 consecutive patients (33 females, 71 males, mean age 60.4+/-7.4 years) were assigned to SR restoration and maintenance with serial antiarrhythmic drugs. Transthoracic echocardiographic (TTE) variables were recorded prior to CV. Generalised additive logistic regression was used to investigate the impact of LA enlargement on the long-term SR maintenance. RESULTS: SR was present in 63.5% of patients after one year of follow-up. Increased LA area >28 cm (RR 1.72; 1.09-2.71; p<0.02) and increased fractional shortening values in ranges between 26-40% (1.2; 1.01-1.44; p<0.05) were significantly associated with SR maintenance after one year. In order to determine the influence of the LA diameter on the probability of SR maintenance, we analysed mean LA(ar) values prior to and after CV. Patients with large LA(ar) (28 cm(2)) presented a significant decrease of LA size (31.45+/-3.07 cm(2) vs 28.94+/-3.81 cm(2); p<0.008) during the first 30 days after SR restoration. In the group of patients with LA(ar) 28 cm(2) we noted decrease in LA size by 2.57+/-3.2 cm(2), whereas in patients with a smaller LA volume this decrease was significantly lower, being 0.47+/-2.9 cm(2) (p<0.004). CONCLUSIONS: LA enlargement does not preclude a favourable outcome after CV of AF. The decrease in LA area occurring during 30 days following CV favours long term SR maintenance.

Aged↗
PubMed2005

Terminological system maintenance: a procedures framework and an exploration of current practice.

The use of electronically stored data requires that the data is recorded in a structured and standardized manner. This has led to the development of terminological systems. The content of these medical terminological systems is subject to continuing changes as a consequence of the developments in the field of medicine.By means of a literature study criteria were obtained for the maintenance of terminological systems. The criteria are used to develop a framework for the management of the maintenance process. The current practice of terminology maintenance was explored in a survey of twenty-seven organizations that currently maintain a terminological system. The results of the survey reveal the diversity and suboptimality of the current maintenance processes. The framework for the management of the maintenance process can be used to eliminate deficiencies in this process. This framework for terminology maintenance is an important step towards standardization of the maintenance of medical terminological systems.

Disease Management↗
PubMed1990

Effects of desipramine maintenance on cocaine self-administration by humans.

Six research volunteers with histories of cocaine use were tested in a cocaine choice paradigm to investigate the effects of desipramine maintenance on cocaine-taking behavior. Subjects were allowed to self-administer i.v. saline or cocaine (8, 16 or 32 mg) in daily 3-hr sessions to establish baseline levels of self-administration, self-reported effects of the drug and changes in heart rate and blood pressure. Each subject was then maintained on daily doses of desipramine for 3 to 4 weeks, after which a second cocaine self-administration dose-response curve was generated under desipramine maintenance. This maintenance had no effect on cocaine self-administration. There was, however, a significant increase in heart rate and blood pressure during desipramine maintenance. Desipramine maintenance also resulted in a change in the profile of cocaine's self-reported effects. In some cases (e.g., Arousal and Vigor on the Profile of Mood States, Benzedrine Group scale on the Addiction Research Center Inventory), reports of cocaine's effects were significantly reduced under conditions of desipramine maintenance, and in others (e.g., Anxiety, Anger and Confusion on the Profile of Mood States), those reports were significantly increased. Furthermore, there was a significant decrease in subjects response to an "I want cocaine" question while under desipramine maintenance. The data suggest that desipramine does not affect the reinforcing properties of cocaine, but may interfere with its other stimulus properties. Furthermore, the cardiovascular effects of desipramine appear to have the potential for toxicity when that drug is administered in combination with cocaine.

Adult↗
PubMed1981

Maintenance management of acute nonlymphocytic leukemia.

The necessity of intensive maintenance chemotherapy in enhancing the duration of life in patients with acute nonlymphocytic leukemia (ANLL) in remission has been evaluated. Twenty-four patients were managed with maintenance chemotherapy and 24 were not. In patients under 50, there was no evidence that maintenance prolonged survival. In patients over the age of 50, maintenance chemotherapy prolonged survival (p = 0.03). In both groups the duration of first remission appeared to be lengthened in patients on maintenance chemotherapy (p = 0.09). Since patients 50 and older were difficult to reinduce, it appears that the greatest prolongation of life for them is afforded by continuous maintenance chemotherapy which may forestall relapse. On the other hand, patients less than 50 years of age have a high likelihood of achieving a second complete remission; it is in this group that maintenance chemotherapy adds only to morbidity.

Acute Disease↗
PubMed1996

A positron emission tomography study of the short-term maintenance of verbal information.

Positron emission tomography (PET) was used to investigate the functional brain anatomy associated with the short-term maintenance of linguistic information. Subjects were asked to retain five related words, unrelated words, or pseudowords silently for the duration of a 40 sec PET scan. When brain activity during these short-term maintenance tasks was compared with a visual fixation control task, increases were found bilaterally in the dorsolateral prefrontal cortex and cerebellum, and medially in the supplementary motor area. Furthermore, effects of stimulus condition and recall performance were found in the left frontal operculum. To investigate the role of articulatory systems in the maintenance of verbal information, regional activation was compared across the maintenance tasks and a covert articulation task (silent counting). The cerebellum was active in both task conditions, whereas activation in prefrontal regions was specific to the maintenance condition. Conversely, greater activation was found in a left middle insular region in the silent counting than in the maintenance tasks. Based on converging results in this and previous studies, dorsolateral prefrontal cortical areas appear to contribute to the maintenance of both verbal and nonverbal information, whereas left frontal opercular regions appear to be involved specifically in the rehearsal of verbal material. Contrary to results found in other studies of working memory, activation was not found in the inferior parietal cortex, suggesting that this area is involved in aspects of stimulus encoding and retrieval, which were minimized in the present study.

Adult↗