Relation between plasma and saliva concentrations of enoxacin, ciprofloxacin, and theophylline

To assess the reliability of predicting plasma concentrations of enoxacin, ciprofloxacin, and theophylline from drug concentrations in saliva, six healthy volunteers received single oral doses of enoxacin, ciprofloxacin, and theophylline administered in combination on each of four separate study days, with different, doses separated by at least 5 days. Drug concentrations were determined by a newly developed high-performance liquid chromatography (HPLC) assay, which could measure simultaneously all three drugs in plasma or saliva. Saliva data from the postabsorptive phase after drug administration were used to minimize the effects of variation in absorption. There were good correlations between saliva and plasma concentrations of enoxacin, ciprofloxacin, and theophylline (r = 0.91, 0.88, and 0.98, respectively). The mean (+/-SD) saliva-to-plasma (S/P) ratio for theophylline was 0.63 +/- 0.06 with a coefficient of variation (CV) of 7.9 +/- 2.7%. In contrast, the S/P ratios and CV values for enoxacin and ciprofloxacin were 0.72 +/- 0.21 and 28.9 +/- 11.1%, and 0.58 +/- 0.15 and 25.3 +/- 6.7%, respectively. Because of the large inter- and intraindividual variability, saliva concentrations of enoxacin and ciprofloxacin are not reliable for predicting plasma concentrations. However, saliva may be used reliably for predicting plasma concentrations of theophylline.

Pharmacokinetic optimisation of drug therapy in elderly patients

With increasing age, there are a number of physiological changes that affect the handling of drugs in the human body. Increases in body fat percentage as well as decreases in lean body mass, hepatic metabolism and renal elimination capacity are of particular clinical significance. It is important to take these changes into account when choosing drug therapy for older patients in order to minimise adverse effects and maximise potential benefits. This is particularly important when prescribing drugs with a narrow therapeutic index such as digoxin, theophylline, phenytoin, lidocaine (lignocaine) or warfarin. When available, monitoring of plasma concentrations can assist in the optimisation of drug dosage.

Epidural analgesia versus intravenous patient-controlled analgesia. Differences in the postoperative course of cancer patients

BACKGROUND AND OBJECTIVES

This study evaluated 462 consecutive surgical cancer patients who underwent uncomplicated surgeries of the thorax or abdomen, or both, of more than 3 hours duration between 1989 and 1991.

METHODS

Patients received either epidural analgesia (EA group) with 0.1% bupivacaine, 0.01% morphine sulfate after combined general-epidural anesthesia, or parenteral morphine therapy via intravenous patient-controlled analgesia (IV-PCA) after balanced general anesthesia after the operation. Patients in both the EA (n = 352) and IV-PCA (n = 100) groups were compared for demographics, length of surgical intensive care unit (SICU), and hospital stays. Moreover, the same comparisons were performed when patients were allocated into surgical subgroups: thoracic (TH), upper abdominal (UA), lower abdominal (LA), radical hysterectomies (RH), and RH with colon resection (RHCR).

RESULTS

No differences existed with respect to age or sex between the EA and IV-PCA groups. All patients reported adequate dynamic pain control as evaluated with visual analog pain scores (VAS < 4/10), during the treatment periods (5 +/- 3 versus 5 +/- 2 days, EA versus IV-PCA). Overall, 262 (58%) patients were admitted to the SICU after the operation, 205 (58%) from the EA group and 57 (57%) from the IV-PCA group. Patients in the EA group required less ventilatory support than did those in the IV-PCA group (0.5 +/- 0.8 versus 1.2 +/- 0.9 days, P < .05). Patients in the EA group also spent less time in both the SICU (1.3 +/- 0.8 versus 2.8 +/- 0.6 days, P < .05) and in the hospital (11 +/- 3 versus 17 +/- 5 days, P < .05) than did their counterparts in the IV-PCA group. Significant differences were also found when subgroup comparisons were made.

CONCLUSIONS

The use of both analgesic techniques was associated with satisfactory postoperative pain control. However, patients receiving epidural anesthesia and analgesia experienced faster recovery as judged by shorter mechanical ventilation time, and decreased SICU and hospital stays, resulting in significantly lower hospitalization costs. The use of perioperative epidural techniques should be considered to expedite recovery of surgical patients, and has the added benefit of being cost effective by reducing hospital stays.

Ileoanal teaching tools: developing a tool to meet a specific need

As ET nurses working with ileoanal surgery patients for the first time in 1979, we discovered that there were no tools or materials available for teaching our patients how to care for themselves during the various stages of the procedure. Over the years, therefore, we have created a compilation of data based on answers to questionnaires completed by recent patients. This data base contains information on topics such as skin care and diet, and enables us to create teaching tools tailored to our own patient population. Although there are now other materials available for teaching self-care to ileoanal surgery patients, the ongoing collection of data from a particular group of patients can also help to create valuable teaching tools and enhance overall understanding of this complex procedure.

Individual and combined effects of cimetidine and ciprofloxacin on theophylline metabolism in male nonsmokers

1. The individual and combined effects of cimetidine and ciprofloxacin on theophylline metabolism were examined in six young male nonsmokers. 2. Treatment sequence consisted of 7 days each of cimetidine 400 mg p.o. every 12 h. ciprofloxacin 500 mg p.o. every 12 h, and the combination of cimetidine and ciprofloxacin. 3. Studies of theophylline pharmacokinetics were performed at baseline and on the fifth day of each regimen. 4. Individually, cimetidine and ciprofloxacin decreased the clearance of theophylline by 25% and 32%, respectively. Therapy with the combined regimen resulted in a 41% reduction in theophylline clearance, which was greater than that achieved with each drug alone (P < 0.01). 5. Ciprofloxacin, in contrast to cimetidine, inhibited N-demethylations of theophylline to a significantly greater extent than the hydroxylation pathway. Combined treatment produced a further decline in formation of 1,3-dimethyluric acid than each drug alone. 6. These data suggest that coadministration of cimetidine and ciprofloxacin exerts a greater impairment of theophylline biotransformation than each inhibitor alone. The enhanced inhibitory effect from the two inhibitors will occur only when sub-maximal doses of each individual agent are used.

The effect of tocainide on theophylline metabolism

The effect of 5 days of oral tocainide (400 mg every 8 h) on the kinetics of theophylline given as a single 5 mg kg-1 i.v. infusion over 30 min was investigated in eight healthy male nonsmokers. Treatment with tocainide decreased the plasma clearance of theophylline from 37.5 +/- 6.9 (mean +/- s.d.) to 33.7 +/- 5.0 ml kg-1 h-1 (difference -3.8, 95% CI, -1.7 to -5.9; P = 0.004) and increased its terminal elimination half-life from 9.7 +/- 2.5 to 10.4 +/- 2.1 h (difference 0.7, 95% CI, 0.2 to 1.2; P = 0.011). Tocainide decreased the formation clearances of 3-methylxanthine and 1-methyluric acid, but the formation clearance of 1,3-dimethyluric acid was unaltered. These data indicate that tocainide exerts a modest inhibitory effect on theophylline metabolism. The magnitude of this change is substantially smaller than that reported to be produced by mexiletine.

Variation of mosquito (Diptera: Culicidae) relative abundance and Dirofilaria immitis (Nematoda: Filarioidea) vector potential in coastal North Carolina

At an enzootic focus of Dirofilaria immitis in coastal North Carolina, mosquito populations were sampled June-September 1985 and on several occasions during August-October 1986 and June-August 1987, to identify local vectors and to determine relative abundance and D. immitis infection rates. Predominant species collected were Anopheles bradleyi King (66.6%), Culex salinarius Coquillett (15.9%), Aedes taeniorhynchus (Wiedemann) (8.2%), and Aedes sollicitans (Walker) (4.9%). Population abundance varied within and among seasons. D. immitis infection was found in An. bradleyi (1.2%), Ae. taeniorhynchus (0.9%), and Ae. sollicitans (0.9%). Of infected An. bradleyi, 88% were collected June-2 July, whereas the highest number of infected Ae. taeniorhynchus and Ae. sollicitans were found during mid-July 1985. Ae. sollicitans and Ae. taeniorhynchus were the only infected species found during 1986 and 1987. However, based on overall relative abundance and infective rate, An. bradleyi appeared to be the primary vector of D. immitis in the study area.

Can patients with chest pain and normal coronary arteries be discriminated from those with coronary artery disease prior to coronary angiography?

To determine whether the precatheterization clinical data in patients with chest pain could be used to discriminate patients with normal coronary arteries (NCA) from those with coronary artery disease, the authors compared 125 consecutive patients with less than 30% stenosis of all major coronary arteries and 125 patients with greater than 60% stenosis of one or more major coronary arteries. Clinical characteristics that occurred more frequently in patients with NCA were: nonexertional pain, pain to the left of the sternum, sharp pain, associated palpitations, absence of typical relief with sublingual nitroglycerin, pain commencing less than one week or more than ten years prior to coronary angiography, a normal electrocardiogram, and negative results from a treadmill stress test or from thallium scintigraphy. However, none of these clinical features, either singly or in combination, could be used to identify the patients with NCA with certainty.

Pulmonary hemodynamics in systemic hypertension

We reviewed cardiac catheterization data and the medical records of 30 patients with systemic hypertension to establish their pulmonary hemodynamic profiles and the relationship between certain clinical and demographic variables and increased pulmonary vascular resistance. Mean systemic arterial pressure ranged from 110 to 210 mm Hg, and systemic vascular resistance ranged from 17.6 to 47.0 units. Seven patients had normal pulmonary wedge pressure and normal pulmonary vascular resistance, one had elevated pulmonary wedge pressure and normal pulmonary vascular resistance, five had elevated pulmonary wedge pressure and increased pulmonary vascular resistance, and 17 had normal pulmonary wedge pressure and increased pulmonary vascular resistance. There were significant positive correlations between systemic vascular resistance and pulmonary vascular resistance and between mean systemic arterial pressure and mean pulmonary artery pressure, but there was no correlation between mean pulmonary wedge pressure and pulmonary vascular resistance. Of the 17 patients with normal pulmonary wedge pressure and increased pulmonary vascular resistance, seven had clinical or radiologic evidence of prior left ventricular failure. We conclude that increased pulmonary vascular resistance occurs commonly in patients with systemic hypertension. Although some cases of increased pulmonary vascular resistance relate to active or preexistent left ventricular failure, the majority remain unexplained, suggesting that neurohumoral or other factors may produce a hypertensive response in both the systemic and pulmonary arterial circuit.

The effect of myocardial preservation technique on operative mortality in complex valvular heart disease

Between November, 1964 and January, 1983, 70 consecutive patients underwent primary repair of complex valvular heart disease, defined as repair or replacement of two or more cardiac values alone or with other concomitant cardiac procedures. A total of 163 operative procedures were performed on the 70 patients for an average of 2.33 procedures per patient. Review of these cases allowed the patients to be divided into two distinct groups, those receiving systemic hypothermia and cold potassium cardioplegic arrest of the heart (C) and those having other myocardial preservation techniques (NC). Thirty-three patients received C and are compared with 37 patients who received NC. The two patient groups were comparable when considered for preoperative cardiac index and functional classification though patients in C group were older. In the C group, 10 of 32 patients (31%) had associated coronary artery bypass grafting in contrast to 2 of 37 patients (5.4%) in the NC era. The mortality of the C group was 2 of 33 (6%) vs 14 of 37 (37.8%) in the NC group (P less than .001). Of the 14 deaths in the NC patients, 10 were due to low cardiac output syndrome. While other factors have undoubtedly played a role, improved myocardial preservation by the use of C and attention to coronary artery pathology may have contributed to the improved operative mortality in this group of patients with complex valvular heart disease.

Lectin-dependent cell-mediated cytotoxicity: assessment of cytotoxic reactivity following challenge with syngeneic tumors

Spleen cells from syngeneic tumor-bearing mice were examined for direct cell-mediated cytotoxicity (DCMC) and lectin-dependent cell-mediated cytotoxicity (LDCC). In the DCMC assay specific cytotoxicity against the homologous tumor cell was assessed. In the LDCC assay cytotoxicity was nonspecifically assessed against EL-4 cells in the presence of concanavalin A or phytohemagglutinin. Most tumor lines tested (19/22) produced no cytotoxic reactivity in either the DCMC or LDCC assays. In the case of the remaining tumor lines (EL-4, BW5147-3, and P815 Y-3), significant LDCC, but not DCMC, was detected, which indicated that although cytotoxic effector cells had been activated, the reactivity was not directed toward the homologous tumor cell or could not be expressed in the DCMC assay. The EL-4 and BW5147-3 cell lines proved to be sporadic in terms of their ability to induce LDCC, whereas the P815 Y-3 cell line produced consistent LDCC. Reactivity induced by P815 Y-3 cells appeared to be due to the constitutive production and release of a soluble component which could activate cytotoxic T-cells in vivo.

Ventricular septal rupture after acute myocardial infarction: diagnosis by two-dimensional echocardiography

A 69-year-old woman had ventricular septal rupture after acute anterolateral myocardial infarction. The defect was demonstrated directly by two-dimensional echocardiography. The appearance of negative contrast in the right ventricle during systole and microbubbles traversing the defect from right to left during diastole further confirmed the rupture. Two-dimensional echocardiography also accurately characterized the nature and extent of associated myocardial damage.

Lectin-dependent cell-mediated cytotoxicity following in vitro culture of normal lymphocytes in medium containing 2-mercaptoethanol

Cell-mediated cytotoxic reactivity resulting from the in vitro incubation of normal lymphocytes was assessed using nonspecific lectin-dependent cell-mediated cytotoxicity (LDCC) as a measure of overall reactivity. Spleen cells from non-immune C57BL/6 mice were incubated in vitro in RPM1-1640 supplemented with 10% fetal calf serum and 2-mercaptoethanol (2ME). Cytotoxicity was assayed against syngeneic Cr51-labeled EL-4 cells in the presence of Con A or PHA. Optimal LDCC was observed after 8 days of culture in the presence of 5 X 10(-5) M 2ME. Cytotoxicity was mediated by an activated T-lymphocyte population whose development did not appear to require macrophages. Usually LDCC in the presence of PHA was significantly greater than that obtained in the presence of Con A. The presence of 2ME during the initial phase of culture was crucial for the development of cytotoxicity, since early removal of 2ME after 1 or 3 days of culture did not alter the subsequent development of cytotoxicity, whereas delayed addition of 2ME on day 1 or 3 failed to produce cytotoxic reactivity. This rapid conversion from a 2ME sensitive state to a 2ME insensitive state may be related to a rapid loss of accessory cell viability during the early phase of culture. Together the results indicate that this system may provide a useful model for the investigation of the events leading to the development of CTL in vitro.

Observer variation in the angiocardiographic diagnosis of mitral valve prolapse

The purpose of this study was to assess the reliability of the angiocardiographic diagnosis of mitral valve prolapse by measuring agreement between observers using defined diagnostic criteria. Sixty high-quality left ventriculograms, selected to include many that showed possible mitral valve prolapse, were reviewed by three angiocardiographers. Disagreement between observers as to positivity occurred in 26 percent and 30 percent of the cases on two reviews, and disagreement as to specific scallop involvement occurred in 68 percent and 78 percent of the cases. A specific observer agreed with himself in interpretation of positive 78 to 82 percent of the time and in the interpretation of specific scallop involvement 55 to 90 percent of the time. These results indicate that in the absence of generally agreed upon quantitative angiocardiographic criteria for the diagnosis of mitral valve prolapse, there is considerable variability among observers in the interpretation of mitral valve prolapse by angiocardiographic studies.

Effect of allogeneic challenge dose and cyclophosphamide treatment on the development of delayed-type hypersensitivity and cell-mediated cytotoxicity

Mice were challenged with high (10(8)) or low (10(4)) numbers of allogenic tumor cells and assessed for cellular immunity. The responses obtained indicated that high dose challenge produced both delayed-type hypersensitivity (DTH) and cell-mediated cytotoxic reactivity (DCMC), while low dose challenge produced DTH, an apparent suppressive effect, and little or no DCMC. Pretreatment with 100 mg/kg of cyclophosphamide (CTX) 3 d before antigen failed to alter this pattern, but treatment 3 d after antigen administration abrogated both DTH and DCMC. Animals given a combined modulating protocol consisting of an initial low dose challenge followed on day 3 by CTX treatment and day 6 by a high dose challenge developed DCMC in the presence of a greatly reduced or absent DTH response. These results demonstrate the differential effects of allogeneic challenge dose on the development of cellular immunity; the differential effects of CTX treatment given prior to or following alloimmunization, and demonstrate how these effects can be combined to modulate the immune response by selectively activating subpopulations of T-lymphocytes.

Pulmonary hemodynamics in systemic hypertension. Long-term effect of minoxidil

To assess the effect of minoxidil on pulmonary hemodynamics, we performed cardiac catheterization on ten patients, prior to the administration of minoxidil, at six months after its addition to their existing drug regimens, and on seven patients following 12 or more months of minoxidil therapy. Systemic blood pressure and systemic vascular resistance were significantly reduced at six months and following 12 or more months of minoxidil therapy. Before receiving minoxidil, nine of ten patients had elevated pulmonary vascular resistance. There were no significant changes in pulmonary vascular resistance following the initiation of minoxidil. The data suggest that pulmonary hypertension is common in patients with long-standing poorly controlled systemic hypertension, and that minoxidil, in doses sufficient to significantly reduce systemic blood pressure, does not cause or aggravate pulmonary hypertension.

Isolation and partial sequence of the cyanogen bromide peptides from calf thymus non-histone chromosomal protein HMG 1

Peptides produced by cyanogen bromide cleavage of non-histone chromosomal protein HMG 1 have been isolated and characterized, and their partial sequences determined. The sequence data presented here account for over half of the sequence of the HMG 1 molecule and, together with previously published results, provide interesting information on the charge distribution within the molecule.

The noninvasive cardiac evaluation of long-distance runners

Twelve long-distance runners were evaluated by physical examination, electrocardiogram, vectorcardiogram, chest x-ray film, and echocardiogram; and the results were compared to the findings in 12 normal control subjects. The athletes showed a significantly higher frequency of gallop rhythms with a third or fourth heart sound. Electrocardiographic and vectorcardiographic abnormalities consisting of right or left ventricular hypertrophy, bradycardia, and alterations in the ST-T wave were also present in the runners. Echocardiographic examination of the athletes revealed increased wall thickness, left ventricular muscular mass, diastolic volume, and ventricular function. It is essential that the physician who examines athletes be aware of the spectrum of apparently abnormal findings in this group. Echocardiographic studies should prove useful in establishing the presence or absence of some forms of cardiac disease in athletes.

Mitral regurgitation secondary to ruptured chordae tendineae: clinical, hemodynamic and electrocardiographic findings

The clinical, hemodynamic, and electrocardiographic findings in 11 patients with mitral regurgitation secondary to ruptured chordae tendineae are presented. Left atrial overloading, as manifested by a large terminal negative force in the P wave of lead V1, was present in 8 of the 11 patients. Six of the eight patients with this atrial abnormality had a normal size or minimally enlarged left atrium on chest x-ray films and angiography. Left ventricular hypertrohpy was present in 7 of the 11 patients and appeared to be related to the duration of cardiac symptoms. It is concluded that a large terminal negative force in the P wave in lead V1 is a useful clinical indicator of increased left atrial pressure in mitral regurgitation of recent onset. The electrocardiographic finding of left atrial overloading is to be expected in most cases of mitral regurgitation secondary to rupture of the chordae tendineae.