John E. Hammond

Possible ovulatory deficiency after tubal ligation

Mean plasma progesterone levels measured in the midluteal phase of the menstrual cycle were lower in 8 women requesting reversal of prior tubal ligation than in 19 normal women (9 vs. 18 ng/ml; P < .05). Based on previous findings that such progesterone assays are good indexes of luteal function and that women with marginally decreased progesterone levels have conceived after treatment with clomiphene it is speculated that persistent infertility after tubal reanastomosis is due to a deficiency of ovarian function especially since pregnancy rates after sterilization reversal are lower than the tubal patency rates. Retrospective and prospective studies of plasma progesterone estrogens and gonadotropins in women who have been or are planning to be sterilized are underway to establish the incidence of ovarian hormonal dysfunction after sterilization by various methods. Establishment of the incidence of hormonal dysfunction after sterilization not only may facilitate management of patients desiring restoration of fertility but also may be relevant to reported observations of an apparent increased frequency of poststerilization menorrhagia which has been hypothesized as due to interruption of the ovarian blood supply two-thirds of which is transmitted via the tubal artery from the uterine cavity.

Daily variation of lipids and hormones in sera of healthy subjects

The physiological day-to-day variation of selected hormone and lipid concentration values in sera of healthy subjects was studied. We drew blood specimens from 14 healthy volunteers, aged 22 to 40 years, (8 male and 6 female) at 0800 h on six separate days over a ten day interval. On one occasion all the twelve specimens from each subject (6 days X 2 replicates) were assayed for the hormones: thyroxine and cortisol; and the lipips: cholesterol and triglyceride which were analyzed by enzymatic methods. The assays were performed on one occasion in order to eliminate the batch-to-batch analytical variation which would tend to blur the physiological day-to-day variation. Using an analysis of variance technique, the total variation was separated into the physiological intraindividual day-to-day variation, the biological inter-individual variation, and the within-batch analytical variation. The mean physiological day-to-day variations in terms of percent coefficient of variation were 7.5% for thyroxine, 26.6% for cortisol, 4.8% for cholesterol, , and 25.0% for triglycerides.

Making the transition from information systems of the 1970s to medical information systems of the 1990s: the role of the physician's workstation

Many hospitals today have implemented widely disparate information systems on mainframe and mini-computer hardware. The advent of network technology in hospitals has made it possible to access information in these systems. Unfortunately, the user interfaces to applications on these systems are unique and difficult to learn, which makes them unsuitable for use by clinical services. In this paper we describe the development of a Physicians Workstation which integrates information from multiple existing information systems and discuss how the workstation makes it possible to move from the departmental systems of the present to the computer-based medical record system of the future.

A routine method for the determination of digoxin in urine by radioimmunoassay

We describe a radioimmunoassay for the routine determination of digoxin in urine employing readily available commercial reagents. The standard curve was found to exhibit very good linearity represented by a composite correlation coefficient of 0.9993 and a standard error of estimate which was less than 1% of the digoxin concentration range of interest. Between-assay precision was excellent as reflected by the coefficient of variation (CV) which averaged 5.29%. Studies assessing the recovery of the present method showed satisfactory results of 106% at a low level of digoxin excretion and 102% at a higher excretion level. Our laboratory carried out a study of digoxin bioavailability in which a standard digoxin dose of 500 micrograms was given to 16 volunteers and the present radioimmunoassay method was employed to measure digoxin excretion. An amount equal to 33.4 +/- 6% of the drug given was eliminated 48 h following digoxin dosing.

Absorption of Digoxin from Tablets and Capsules in Subjects with Malabsorption Syndromes

The relative steady-state bioavailability of two oral digoxin dosage forms was studied in 17 subjects with malabsorption syndromes. Male subjects received the following treatments in randomized crossover fashion for 14 days: Three 0.125-mg digoxin tablets or three 0.1-mg digoxin capsules once daily. Female subjects received digoxin on the same schedule but at two-thirds the dose. Serum and urine samples were collected and analyzed for digoxin by radioimmunoassay, and treatments were compared by evaluating pharmacokinetic parameters. The mean area under the serum concentration versus time curve for tablets (28.1 h•nmol/L [21.9 h•ng/mL]) was smaller (p < 0.03) than that for capsules (31.1 h•nmol/L [24.3 h•ng/mL]), and the mean maximum serum digoxin concentration for tablets (2.9 nmol/L [2.3 ng/mL]) was lower (p < 0.02) than that for capsules (4.0 nmol/L [3.1 ng/mL]). There was no difference in cumulative urinary excretion of digoxin between the two treatments. In contrast to previous reports, we observed that digoxin from Lanoxin Tablets appears to be well absorbed in subjects with malabsorption. Nevertheless, these subjects absorbed digoxin from capsules better than from tablets, with the greatest differences occurring in subjects without a colon and in those subjects with the lowest serum carotene concentrations.The relative steady-state bioavailability of two oral digoxin dosage forms was studied in 17 subjects with malabsorption syndromes. Male subjects received the following treatments in randomized crossover fashion for 14 days: Three 0.125-mg digoxin tablets or three 0.1-mg digoxin capsules once daily. Female subjects received digoxin on the same schedule but at two-thirds the dose. Serum and urine samples were collected and analyzed for digoxin by radioimmunoassay, and treatments were compared by evaluating pharmacokinetic parameters. The mean area under the serum concentration versus time curve for tablets (28.1 h•nmol/L [21.9 h•ng/mL]) was smaller (p < 0.03) than that for capsules (31.1 h•nmol/L [24.3 h•ng/mL]), and the mean maximum serum digoxin concentration for tablets (2.9 nmol/L [2.3 ng/mL]) was lower (p < 0.02) than that for capsules (4.0 nmol/L [3.1 ng/mL]). There was no difference in cumulative urinary excretion of digoxin between the two treatments. In contrast to previous reports, we observed th...

The laboratory workstation: a data management model for a small laboratory section

Many small sections of clinical chemistry laboratories fail to benefit fully from laboratory information system (LIS) installation because the volume does not justify cost of interfacing the instruments in these sections to the LIS. The opportunity for manual data entry errors remains a problem in these sections. This paper describes the design of a laboratory workstation that serves as a data hub that makes it feasible to use one instrument interface line from the LIS to acquire data from four instruments. This approach reduces the likelihood of data entry error and improves the efficiency of personnel in the laboratory section. Further, the tools necessary to create such a workstation are commercially available and do not depend on microcomputer programming and support personnel within the chemistry laboratory.

A managed care workstation for support of ambulatory care in Veterans Health Administration medical centers

This paper describes the development of a Managed Care Workstation for implementation in a Department of Veterans Affairs hospital. Each VA hospital information system contains a wealth of information in a comprehensive and well integrated M database, however, a clinicians access to the information is hampered by a lack of usable database tools. The Managed Care Workstation is designed to enhance access to VA databases. The workstation uses M (Mumps) and SQL to present the VAs M hierarchical database as relational tables on the workstation. This work reveals the benefits of using a SQL-M workstation to access data contained in an M based hospital information system and demonstrates how the workstation architecture supports the information model necessary for management of patient care outcomes.