Characterisation of red and white thrombus by intravascular ultrasound using radiofrequency and videodensitometric data-based texture analysis.

Visual assessment of intravascular ultrasound (IVUS) video images cannot reliably identify thrombus. We examined if texture analysis of radiofrequency (r.f.) data or videodensitometric data (VD) could distinguish thrombi of different ages and cell compositions. Whole human blood (red clot = RC), platelet-rich plasma (white clot = WC) and plasma (n = 6/group) were imaged at 4 and 24 h with 30 MHz IVUS transducers. At 4 h, VD- and r.f.-based analyses revealed significant differences between RC and WC with variance (VD red 26.4 +/- 2.5, white 33.9 +/- 7.8; r.f. red 1.4 +/- 0.5, white 4.9 +/- 1.3), kurtosis (VD red 0.29 +/- 0.9, white 0.23 +/- 0.3) and skewness (VD red 0.23 +/- 0.13, white 0.35 +/- 0.52; r.f. red 0.06 +/- 0.01, white -0.06 +/- 0.05). Also mean grey-level from both data sets was higher in RC (VD 134.8 +/- 18.0; r.f. -13.3 +/- 1.2) than in WC (VD 105.3 +/- 17.4, r.f. 16.5 +/- 2.2) (p < 0.01). With increasing time, variance increased in WC (5.5 +/- 1.5 at 24 h) and decreased in RC (0.9 +/- 0.3.3 at 24 h). The more heterogeneous structure of WC may be distinguished from that of RC using texture analysis of either VD or r.f.-signals.

Statistical criteria for separate reference intervals: race and gender groups in creatine kinase.

Previously published data confirming differences in creatine kinase (EC 2.7.3.2) among various race and gender subgroups in the Los Angeles area have been re-examined with use of recently proposed statistical criteria for defining separate reference intervals. Results indicate that one criterion may be too lenient, whereas another is clearly too restrictive in suggesting the need for separate intervals. Further experience with other analytes in both large and small population samples would be helpful.

Menstrual blood loss and body iron stores in Brazilian women.

Menstrual blood loss (MBL) studies are relevant for developing world women as this could be an important cause of anemia. Whenever a contraceptive method is to be used by such women, consideration should be given to the method which least affects the volume of MBL. In 309 women considered as clinically healthy, MBL, serum ferritin, serum iron and hemoglobin levels were measured: a mean MBL of 23 ml was found. Age, weight, height and previous oral contraceptive use did not affect MBL. Higher parity women may have higher MBL levels but their hematologic indices are not altered. While body iron stores (as judged by serum ferritin levels) are depleted in women who bleed more than 60 ml per cycle, clinical anemia may not be present until their blood loss exceeds 80 ml per menstruation. Brazilian women who lose more than 60 ml of menstrual blood associated with multiple pregnancies without adequate iron supplementation may have a depletion of their body iron stores.

Consequences of uterine blood loss caused by various intrauterine contraceptive devices in South American women. World Health Organization Special Programme of Research, Development and Research Training in Human Reproduction.

Increased menstrual blood loss (MBL) associated with intrauterine device (IUD) use may precipitate or aggravate iron deficiency anaemia, adversely affecting the health of women particularly those from developing countries. Studies were conducted to define the association of MBL and iron status in South American women; to determine the level of MBL induced by IUD use which would result in iron depletion, the length of time for this depletion to occur and, comparing various IUDS, to determine if any currently tested IUDs are suited to long-term use in South American women. A total of 395 women received one of 5 types of IUDs in Santiago, Chile, and Juiz de Fora, Brazil: Lippes Loop, Multiload-250 and Multiload-375 were used in both centres; in Santiago some subjects received the Copper-7 or ProgestasertR devices and in Juiz de Fora, the TCu 200 and the T-Chloroquin IUDs were also tested. MBL and haemoglobin (HGB) were measured for 3 menstrual cycles before insertion, and following insertion, at one, two, four, six, nine, twelve, eighteen and twenty-four months in the majority of cases. Serum ferritin was measured before insertion and at intervals of six months. Mean values of MBL prior to IUD insertion in both centres varied from 21-30 ml. As with previous publications, the use of the Lippes Loop was associated with the greatest increase in MBL which was sustained throughout the 24 months of observation. Women who had one of the two types of Multiload devices inserted also had increased MBL and reduced ferritin for at least 12 months of use. TCu 200 and Copper-7 IUD users had an initial increase in MBL of 1 to 17 ml in the first six months of observation returning to normal levels beyond six months. Serum ferritin levels were lower for one year and then returned to admission values. ProgestasertR users confirmed previous reports of a reduction of 40-50% in MBL and an increase in serum ferritin. Few significant changes in haemoglobin (HGB) concentrations were found. Serum ferritin levels on admission ranged from 7.1 to 16.4 ng/ml in Santiago and from 15.8 to 23.2 ng/ml in Juiz de Fora. Many women were in a marginal state of iron balance as evidenced by lower serum ferritin values. Changes in serum ferritin were very closely related to those in MBL.(ABSTRACT TRUNCATED AT 400 WORDS)

A user evaluation of four Kodak Ektachem slide assays.

Evaluations of magnesium, theophylline, creatinine, and creatine kinase isoenzyme MB assays by the Kodak Ektachem multilayer-film technique are reported.

Cost-containment and the use of reference laboratories.

Hospital laboratories and hospital-independent reference laboratories will need to change in order to provide comprehensive, medically appropriate, and reasonably priced laboratory services in the cost-containment age we are entering. The change must be economically and technologically innovative and relevant to society's next generation of health care needs. Hospital laboratories and commercial laboratories may become weaker or stronger relative to one another, but our guess is that they will ultimately become more like one another or even may join forces to provide optimal patient care in the future. Until that time comes, hospital laboratories must decide whether to employ reference laboratory services more or less, enter a joint venture with a reference laboratory, or become a reference laboratory. Some of the items that could be considered in arriving at this decision are listed in Table 2. Some items favor hospital laboratories; some favor reference laboratories; some are a toss-up; and some suggest there are advantages in a team approach. For the present, we believe there are many arguments favoring a continuation and possibly even an expansion of hospital laboratory services, but this will likely be most feasible in financially sound and progressive hospitals having forward-looking administrators and imaginative but fiscally minded laboratory directors and managers. If decisions are made to send more tests to reference laboratories, each hospital or user laboratory must seek the best and most cost-effective services available. Various financial, technical, and medical considerations are described that should aid in the evaluation of where to have tests performed. We have provided suggestions on how agreements with reference laboratories can be established in either a formal (contractual) or an informal (verbal) way. Additionally, we have described methods for evaluating (or monitoring) the quality and quantity of services received from a reference laboratory. In general, for any significant agreement with a reputable reference laboratory, little more may be necessary for monitoring purposes than periodic financial and quality assurance audits and follow-up on any clinical complaints regarding test results. With a large contract, the user laboratory is advised to spot check results on submitted blind duplicates of patient samples (to test provider lab precision) and occasionally to split samples between the provider and one or more other reference laboratories (as a first look at possible inaccuracy).(ABSTRACT TRUNCATED AT 400 WORDS)

'Routine urinalysis'. Is the dipstick enough?

Results of this study indicated that a protein-negative, blood-negative dipstick result may be used to rule out the necessity for performing a microscopic examination in "routine urinalysis" only if one is willing to accept 13% false-negative results. On the other hand, a protein-, blood-, and leukocyte esterase-negative dipstick result was associated with 1.4% to 3.3% false-negative results. The high sensitivity of the leukocyte esterase-measuring dipstick for microscopically abnormal urine samples was dependent on its ability to detect small numbers of leukocytes only when interpreted five minutes after immersing it in the sample. Various approaches may be used by which these findings could be applied to produce cost savings and also protect the small number of patients who may have dipstick-negative, microscopically positive urine.

Immunohistochemical characterization of reactive and neoplastic mast cells.

Mast cells are connective tissue elements likened to unicellular endocrine organs because of the wide diversity of physiologic and pathologic events associated with the secretion of biologically active compounds. Using an immunoperoxidase method (PAP), we studied tissue from patients with benign and malignant systemic mastocytosis and with a variety of reactive conditions. The following immunoreactive antigens were identified in mast cells: a heparinlike compound or compounds (HLC), prostaglandin, serotonin, and fibronectin. HLC is constantly present, staining mast cells in a granular fashion from most lesions. Serotonin and prostaglandin stain in a diffuse cytoplasmic manner in occasional lesions. Fibronectin is found in a surface location in selected cases. We found no clear association between the immunoreactivity of one compound in mast cells and one clinical symptom, e.g., HCL with bleeding, prostaglandin, or serotonin with systemic vasomotor activity or fibronectin with increased tissue fibrosis. However, patients with localized and systemic disease had symptoms that might have been attributed to more than one compound. Only occasional patients with reactive conditions showed such symptoms. The presence of these compounds, either alone or in combination, did not separate benign from malignant conditions. Other cells within selected tissues also stained with the antibodies tested. Despite the lack of exclusivity, these antibodies are useful in identifying mast cells within tissue sections and may have a role in the study of mast cell constituents.

Selection of reference laboratory services.

This article is directed primarily to hospital pathology and clinical laboratories that require the testing services of other laboratories. However, many of the observations and principles presented should apply to other users of reference laboratory services, such as outpatient clinics, public health laboratories, occupational health laboratories or clinics, and even the individual doctor's office.

A rapid and highly sensitive solid-phase radioassay for plasminogen activators.

A rapid and highly sensitive solid-phase radioassay for the measurement of plasminogen activators is presented. The method employs a convenient and stable 125I-fibrinogen-latex bead product and can reproducibly detect 0.25 milli Ploug units/ml of urokinase. This represents a 100-fold increase in sensitivity over previously published radioisotopic solid-phase technique and a 120-fold increase over the sensitivity of the fibrin plate method. Since the assay can readily detect plasminogen activator levels in euglobulin solutions prepared from pre- and post-venous occlusion plasma, it may be useful for rapidly detecting and monitoring the fibrinolytic potential of patients predisposed to thromboembolic disease.

Ordering of laboratory tests in a teaching hospital. Can it be improved?

A review of ordering patterns for thyroid function tests and for measurements of creatine kinase (CK) isoenzyme and lactate dehydrogenase (LDH) isoenzyme levels indicated considerable misuse. We employed an educational program for both types of tests, but changed the request form only for ordering the thyroid function tests. No changes were made in the forms for ordering CK and LDH isoenzyme tests. The effect was a prompt decrease in ordering triiodothyronine radioimmunoassay and thyrotropin tests to 38% and 61%, respectively, of baseline rates. There was no effect on rates of ordering CK and LDH isoenzyme tests, which were 102% and 96%, respectively, of baseline rates. The improved use of thyroid function tests was likely because of the change in the laboratory request form, since the educational strategy by itself had no effect on the ordering of CK and LDH isoenzyme tests.

Comparative electrophoretic analysis of human and porcine plasminogen activators in SDS-polyacrylamide gels containing plasminogen and casein.

Electrophoretic analysis of plasminogen activators from pig heart, human uterus, human plasma and human melanoma cells was performed in SDS-polyacrylamide gradient slab gels containing plasminogen and casein. Direct visualization of activator activity bands in polyacrylamide gels was achieved after removal of SDS, incubation in buffer, and staining with Coomassie brilliant blue. Tissue activator extracted from pig hearts displayed a molecular weight of 72000 and migrated similarly to activator secreted by human melanoma cells and to one activator component present in extracts of human uterus. Immunoadsorption experiments with melanoma cell activator antiserum indicated that these 72-kDa activators are all related immunologically. Human uterus also contained a second activator component with a molecular weight 55000, which migrated similarly to a higher molecular weight component of urokinase and cross-reacted with urokinase antiserum. We conclude that the 72-kDa uterine activator component represents a tissue activator and the 55-kDa component represents a urokinase-like activator. A euglobulin solution from venous occlusion plasma displayed multiple bands of plasmin activity in the Mr range 85000-96000. Two activator components were also present, one of Mr 72000 and another of Mr 62000. The 72-kDa euglobulin activator was adsorbed by MCA antiserum, and we conclude that this component represents vascular activator. The 62000 activator also had weak plasminogen-independent caseinolytic activity and was not affected by either melanoma cell activator or urokinase antisera. Conclusions concerning its identity cannot be made at this time.

Heterogeneity of serum creatine kinase activity among racial and gender groups of the population.

To develop reference ranges for creatine kinase (CK) appropriate for the patient population served by this hospital, levels of serum CK were measured in 1,537 individuals in our employee population. There was substantial heterogeneity in mean, median, and range of CK levels among the several race/gender subgroups in the population studied. The race/gender subgroups could be placed into three broad groups: a high CK group, composed solely of black men; an intermediate CK group, consisting of nonblack men plus black women; and a low CK group, comprised of nonblack women. Mean CK level of the high CK group was twice that of the intermediate CK group, which, in turn, was twice that of the low CK group. Differences in mean CK values among the subgroups placed into either the intermediate CK group or the low CK group were not significant when tested with analysis of variance. Therefore, practical reference ranges for these groups are as follows: 52-520 U/L for the high CK group; 35-345 U/L for the intermediate CK group; and 25-145 U/L for the low CK group.

A high prevalence of hypomagnesemia and hypermagnesemia in hospitalized patients.

The prevalence of hypomagnesemia and hypermagnesemia among hospitalized patients was studied by determining magnesium levels in 621 serum samples randomly selected from those submitted to the clinical chemistry laboratory for a biochemical test panel. The reference range for serum magnesium was established in this study as 1.2 to 1.9 mEq/L from measurements of serum magnesium on 341 healthy volunteers. Hypomagnesemia (less than 1.2 mEq/L) was present in 68 patients or 11.0%, and hypermagnesemia (greater than 1.9 mEq/L) occurred in 58 patients or 9.3%. The degree of association between hypomagnesemia and hypocalcemia was assessed by measuring serum magnesium on a separate group of 61 patients with hypocalcemia (corrected calcium less than 8.6 mg/dL). Hypomagnesemia was present in 23.3% of patients hypocalcemic in the absence of renal failure; this proportion was higher significantly than the 11.0% who were hypomagnesemic in the hospitalized patient group (P less than 0.025).

Changes of plasminogen activator in human uterine tissue induced by intrauterine contraceptive devices.

Potassium thiocyanate-extractable uterine plasminogen activator activity was determined to be highest in the endometrium surrounding intrauterine devices (IUDs). Such activity was significantly higher than that encountered in control endometrium or in the endometrium remote to IUDs. As in control cases, extracted endometrial activity fluctuated during the intermenstrual ovarian cycle. It was highest in the pre- or periovulation part of the cycle, and it rose again prior to menstruation. These peaks of activity seem to correspond to times in the cycle when metrorrhagia and abnormal menstruation are usually encountered. Possible implications of the myometrial and endometrial patterns of plasminogen activator in control and IUD-exposed uterine tissue are discussed.

PIP: This research study was designed to determine the relative activator concentration in uterine tissue depressed by, adjacent to, and remote from the IUD and to compare these concentrations to control uterine tissues. Uterine tissue used in the study was obtained following hysterectomy in 22 women wearing IUDs. All analyzed tissues were acquired from uteri containing either Lippes loop D or large Saf-T-Coils. These IUDs had been in place for a minimum of 1 year and a maximum of 8 years. Hysterectomies were performed primarily for indications related to symptomatic pelvic relaxation secondary to multiparity. No patient was taking hormonal medication or contraceptives for 12 months prior to hysterectomy. No cases included specimens with significant uterine pathology other than that related to the IUD. Ovarian cycle phase was determined for all specimens analyzed by histologic criteria on adjacent slices of the excised samples. Cases included the following phases: menstrual; early proliferative; mid to late proliferative; early to mid secretory; and late secretory. The myometrium contained considerably more extractable activator than the endometrium in terms of activity per milligram of tissue protein. Variation of endometrial plasminogen activator (PA) showed the same pattern as did previously analyzed control specimens at different stages of the intermenstrual ovarian cycle. Values reached the highest levels in mid to late proliferative endometrium with a fall during the early to mid secretroy phase to the lowest levels, followed by a rise in late secretory endometrium. Myometrium did not parallel endometrium as closely as reported for control cases. In IUD cases, the highest myometrial levels were encountered in the late follicular phase and a fall occurred in the secretory phase, as was the case with endometrium, but no myometrial rise occurred prior to menses. Comparison of mean activator results of depressed, adjacent, and remote endometrial sites from IUD cases and mean endometrial activator levels from control cases revealed the highest values in IUD depressed endometrial tissues. The next highest were in IUD adjacent endometrium. Significantly lower results occurred in IUD remote endometrial samples. These comparisons were not considered to be biased by interphase differences in activator since equal proportions of all 4 menstrual phases existed among the 3 IUD sampling sites and the total control material studied. In sum, uterine PA activity plays an important role in IUD associated menorrhagia, and the results indicate that it is also important in IUD associated metrorrhagia. The causes of cyclic physiologic fluctuation and of IUD stimulated increases in uterine PA activity are poorly understood at this time.

Immunohistochemical identification of mast cells in paraffin- and epon-embedded tissues using platelet factor 41.

An immunoperoxidase method has been developed for staining heparin in the granules of mast cells. The method employs human platelet factor 4 (or anti-heparin) and a rabbit antiserum to this polypeptide. Platelet factor 4 binds to mast cell heparin and provides the basis for immunoperoxidase staining using the rabbit antiserum. Preliminary studies of mast cells in various tissues indicate that the stain is quite specific for the content of mast cell granules, presumably heparin and possibly other glycosaminoglycans.

Effects of a progesterone-releasing intrauterine contraceptive device on endometrial blood vessels: a morphometric study.

The concentration of microscopically detectable blood vessels was significantly lower in endometrium exposed to progesterone-releasing intrauterine contraceptive devices (IUDs) than in control endometrium (mean vessel density 2.39 and 3.92, respectively). The percentage of vessels with defects was significantly higher in IUD samples (35.0%) than in control samples (13.4%). There was no significant difference in hemostatic response to vessel injury between the IUD and control samples. Although they were more defective than in controls, the blood vessels of progesterone IUD-exposed endometrium were far fewer in number, which may account for significantly less uterine blood loss in the users of these devices. In addition, the progesterone IUDs do not appear to inhibit hemostasis in the endometrium so that blood loss from injured vessels may be minimized.

PIP: It has been previously demonstrated that increased vascularity, vessel defect formation, and poor hemostasis are prime factors in the increased endometrial bleeding associated with plastic IUDs. This paper presents the results of a morphologic sutdy on progestogen IUD-exposed endometrium to determine the reasons for long-term decreased menstrual blood loss and short-term increased intermenstrual blood loss following insertion of such an IUD. Endometrial biopsies were collected from 8 women wearing a Progestasert at various times in the cycle, and from 9 control women during the middle to late luteal phase of the menstrual cycle. All morphometric and electron microscopic studies were done at the Women's Hospital, Los Angeles County/USC Medical Center. Biopsies from the Progestasert users were taken 54 months after initial insertion. Each progesterone-IUD was replaced approximately every 24 months. Electron microscopy was used to examine the tissue samples. Chi-square test and the Mann-Whitney U Test according to Siegel were used in statistical analysis. Average blood vessel density for the 8 progesterone users was 2.39 (range, 13.0 to 3.71) compared to 3.92 for the controls (range, 3.33 to 4.68); the difference was significant at p0.01, Mann-Whitney test. Vessel concentration ratio of experimental to control endometrium was 3.5. Defective vessels for control cases expressed as a percentage of total vessels ranged from 0% to 24%. For progesterone IUD-endometrium, values per case varied from 7.1% to 64%. Average percentage of defective vessels for controls was 13.4 and for Progestasert users, 35.0%; the difference was significant at p0.001, Chi-square test. Majority of defects in the Progestasert users were associated with degenerative changes in endothelium. The increased concentration of vascular defects in the progesterone IUD-exposed endometria compared to control tissue in this series confirm earlier studies with plastic IUDs and defective vessels. Several factors contribute to decreased endometrial bleeding in women who have worn a progestrone-releasing IUD for at least 6 months. 2 critical factors include: 1) decreasing concentration of blood vessels in the endometrial functionalis (possibly the cause for progressive endometrial atrophy); and 2) no apparent inhibition of platelet hemostasis.

Role of prostaglandins in IUD-associated uterine bleeding--effect of a prostaglandin synthetase inhibitor (ibuprofen).

Prostaglandins have been shown to be increased in the endometrium of women and experimental animals wearing intrauterine devices (IUDs). As prostaglandins may cause increased vascularity and vascular permeability, and as certain prostaglandins (PgI2) inhibit platelet activity, the local generation of prostaglandins may contribute to endometrial bleeding. Thus, the effect of ibuprofen, a prostaglandin synthetase inhibitor, was tested by quantifying menstrual blood loss in 20 women wearing IUDs in a double-blind, 2-period crossover study. Ibuprofen produced a significant reduction in menstrual blood loss; the percentage reduction was greater in women using a Lippes Loop and who had heavier blood loss (39%) than in women using a copper device and who had lighter blood loss (25%). These findings support the contention that prostaglandin synthesis is important in the genesis of IUD-associated menorrhagia and that prostaglandin inhibitors may be useful in the therapy of this condition.

Tritiated water exchange in the human uterine cavity.

Measurements with the use of tritiated water (3H2O) in human volunteers indicate that the mean tritiated water half life (t1/2 3H2O) in the uterine cavity is 1.3 minutes. This figure is very close to that previously measured in subhuman primates. By extrapolation from various prior studies the volume of the human uterine cavity (aVc) may be assumed to approximate 0.4 to 0.6 ml. According to the formula aVc divided by 2 x 1,440 divided by (t1/2 3H2O) water turnover in the human endometrial canal is calculated to range from 222 to 332 ml/24 hours.