Acute myelogenous leukemia with dup(1)(p22p36),dup(1)(p22p36): a novel case?

A case of acute myelogenous leukemia (AML) French-American-British (FAB)-type M5b is described, secondary to myelodysplastic syndrome (MDS), in which a primary clone containing a dup(1)(p22p36) and a subclone containing dup(1)(p22p36), were identified. This is believed to be a novel mutation in AML.

Discontinuations of antihyperlipidemic drug therapy: assessment by means of automated databases

Discontinuations of drugs used in the treatment of chronic conditions such as hyperlipidemia often signal adverse drug effects or therapeutic ineffectiveness. Discontinuations of antihyperlipidemic drug therapy among 2369 patients were evaluated using the computerized files and written medical records of two health maintenance organizations (HMOs) in Massachusetts for the period 1988 to 1990. Three methods were assessed for the identification of potential discontinuations of drug therapy using the automated databases. Overall, 75% of discontinuations flagged by the automated databases were confirmed in the medical charts. (1) In new users, 618 of the 635 (97%) drugs identified as drug switches by the computerized HMO pharmacy files were confirmed as discontinuations by the medical charts. (2) Of 620 eligible HMO members 332 (54%) identified with greater than 6 months between the last refill for an antihyperlipidemic drug and the end of the study stopped the drug therapy according to the medical chart. (3) Of 219 eligible drug therapies flagged with an 'inactive' or with an 'omit' status in the clinical encounter files 198 (90%) were discontinued according to the medical chart. This study demonstrates the utility of clinical automated databases to facilitate the study of drug discontinuations in primary care settings, reducing the cost and the amount of time required for the evaluation.

Prolactin (PRL) is a zinc-binding protein. I. Zinc interactions with monomeric PRL and divalent cation protection of intragranular PRL cysteine thiols

PRL in secretory granules is osmotically inert. Previous studies by us and others have suggested that this is due in part to hormone oligomerization. Data suggest intermolecular disulfide bridges and/or intermolecular ionic interactions, as thiols, urea, and chelators increase monomerization of the majority of granule PRL. Because of the inhibitory effect of zinc on PRL release from isolated granules and the effects of zinc on the specific packing of PRL within granules, we examined the possibility that zinc contributed to the stability and/or oligomerization of intragranular PRL. To do this, we first analyzed zinc binding to purified monomeric rat PRL in solution. Zinc binding was demonstrated using the chromogenic chelator 5,5'-nitrilodibarbituric acid (murexide) and was confirmed by matrix-assisted, time of flight mass analysis. Because these spectrophotometric methods were not applicable for intragranular PRL studies, we tested the influence of zinc on granule PRL indirectly. As hormone free thiols were potentially formed during PRL oligomerization and storage, these were possible sites for hormone-divalent cation interactions. By derivatization of thiols with 4-vinyl pyridine and isolation of the carboxyterminal region of granule PRL, we found that a proportion of the cysteines 189 and 197 occurred as thiols and not disulfides. These thiols were only detectable when EDTA was present in the granule incubations. It is proposed that binding of zinc stabilizes the intermolecularly bonded storage form of PRL, in part by protection of hormone free thiols. Removal of the divalent cation and exposure of free thiols could be what initiates the thiol-disulfide interchange necessary for conversion of intermolecular to intramolecular disulfide bonds before exocytosis. Experimentally, both urea and EDTA could remove zinc, thus initiating monomerization and explaining how these agents as well as thiols achieve monomerization.

Identification of the major site of rat prolactin phosphorylation as serine 177

Phosphorylation of prolactin by endogenous protein kinases within isolated secretory granules was shown to result in the production of both phosphoserine and phosphothreonine residues. The majority of the radiolabel was determined to be present in the C terminus of the molecule after specific cleavage with glandular kallikrein. Glandular kallikrein cleaves in three places at the C terminus, liberating three small peptides, only one of which contains a phosphorylatable residue. Sequencing of this phosphopeptide showed it to be Arg175-Lys185. Thus the major site of prolactin phosphorylation was determined to be serine 177. Using a synthetic peptide equivalent to this region of the molecule (Ser161-Val180), serine 177 was demonstrated to be a substrate for protein kinase A as well as for one of the endogenous granule kinases. Inclusion of the synthetic peptide in an endogenous granule phosphorylation reaction resulted in competition for the kinase and reduced phosphorylation of prolactin. Protein kinase A phosphorylation of purified prolactin resulted in the production of only phosphoserine and primarily the most abundant (monophosphorylated) variant. We conclude that serine 177 is the major in vivo phosphorylation site of rat prolactin and that phosphorylation of this site can be reproduced by protein kinase A in vitro. The minor threonine phosphorylation site was demonstrated by two-dimensional tryptic peptide mapping and mass analysis to be either threonine 58 or 63, both of which are contained within a single peptide.

Interrelation between ventricular function, myocardial blood flow, and O2 consumption changes at birth in lambs

We studied the interrelation of changes in ventricular external work, myocardial blood flow, and O2 consumption at birth. Eleven fetal sheep were instrumented under general anesthesia at 133-134 days gestation with arterial, peripheral venous, and left atrial catheters, and in five fetuses, a catheter was also inserted into the coronary sinus. Fetal left ventricular (LV) and right ventricular (RV) outputs and myocardial blood flows (radioactive microspheres), hemodynamics, and LV O2 consumption were measured 1 wk later. Fetuses were delivered by cesarean section, and measurements were repeated 1 and 4 h after birth. RV minute work (mmHg.l.kg-1) was greater in fetuses (10.8 +/- 0.5 vs. 15.6 +/- 1.0 P < 0.001), but because of increased LV minute work (to 20.9 +/- 1.4, P < 0.005) and unchanged RV minute work, this pattern was reversed by 1 h after birth. RV myocardial blood flow (ml.min-1.100 g-1) was predominant in fetuses (234 +/- 25 vs. 306 +/- 27, P < 0.001), but this also reversed in lambs; this reversal was related to unchanged 1-h (248 +/- 16) and lower 4-h LV myocardial blood flow (199 +/- 9, P < 0.05) and a progressive fall in RV myocardial blood flow (1 h: 245 +/- 20, P < 0.05; 4 h: 174 +/- 12, P < 0.005). LV O2 consumption (ml.min-1.100 g-1) increased between fetal (8.1 +/- 0.6) and 1-h lambs (18.9 +/- 1.3, P < 0.005) because of a rise in the LV arteriovenous O2 content difference (3.6 +/- 0.4 vs. 7.5 +/- 0.6 ml/dl, P < 0.005). External work performed per unit myocardial blood flow (mmHg.l.ml-1) in the LV increased between fetal and 1-h lambs (1.92 +/- 0.14 to 3.33 +/- 0.15, P < 0.001) and, in the RV, between fetal and 4-h lambs (2.09 +/- 0.18 to 2.92 +/- 0.24, P < 0.01). The proportion of consumed O2 converted to external work was, however, similar in fetal (34.6 +/- 3.1%) and 1-h (31.3 +/- 2.9%) and 4-h lambs (34.5 +/- 3.6%). These findings indicate that 1) a switch from a fetal RV to a newborn LV dominance is due to increased LV pumping performance, 2) an associated switch in LV and RV myocardial blood flow patterns is mainly related to a fall in RV myocardial blood flow, 3) a postnatal rise in LV O2 consumption results from enhanced LV arteriovenous O2 extraction, not increased LV myocardial blood flow, 4) ventricular external work per unit myocardial blood flow increases postnatally, particularly in the LV, and 5) LV mechanical efficiency is not altered after birth.

Manduca sexta lipid transfer particle: synthesis by fat body and occurrence in hemolymph

Lipid transfer particle (LTP) is present in hemolymph of the tobacco hornworm Manduca sexta. Biosynthesis of LTP, occurrence in hemolymph, and the role of LTP-apoproteins in the lipid transfer reaction were investigated using antibodies specific for LTP or for each of the apoproteins. In vitro protein synthesis followed by immunoprecipitation demonstrated that LTP is synthesized by the fat body and secreted into the medium. In contrast to apolipophorin III, an exchangeable apoprotein of lipophorin (the major lipid transport protein in hemolymph), apoLTP-III could not be detected free in hemolymph. LTP concentrations in the hemolymph were measured by a sandwich ELISA using a mouse monoclonal antibody against apoLTP-III as capturing antibody and rabbit polyclonal antibody against apoLTP-I as detecting antibody. LTP concentration increased during the late fifth instar larval stage, followed by a decrease in the wandering stage. Subsequently, LTP concentrations were strongly increased in hemolymph of adult moths. The role of the three apoproteins of LTP in the lipid transfer reaction was analyzed using apoprotein-specific antibodies. All three, apoLTP-I, -II, and -III, appeared to be important for lipid transfer activity, as shown by inhibition of lipid transfer by antibodies specific for each of the three apoproteins.

Patient factors associated with strut fracture in Björk-Shiley 60 degrees convexo-concave heart valves

BACKGROUND

Previously established predictors of outlet strut fracture in Björk-Shiley convexo-concave (CC) valves include larger valve size, larger opening angle (70 degrees versus 60 degrees), younger age at implant, and date of manufacture. We sought to identify patient characteristics that might be predictive of strut fracture and to refine the estimates associated with previously identified predictors.

METHODS AND RESULTS

We conducted a case-control study of CC60 degrees valves implanted in the United States and Canada and manufactured between January 1, 1979, and March 31, 1984. Cases included all valves with verified outlet strut fractures reported to the manufacturer from January 1979 through January 1992. Up to 10 controls were selected for each case. Control valves were matched according to implanting surgeon and were required to have been functioning at least as long as their matched case valves. Case and control medical records were reviewed for information on patient medical history before the valve implant. There were 96 case and 634 control valves for which clinical data were available. Patient age and valve size and implant position were confirmed as important determinants of fracture. There was a strong inverse gradient of risk with age. The risk of fracture was 42% lower for each 10-year increment of patient age at time of implant. Large mitral valves were at greatest risk of strut fracture, with the largest mitral valves (33 mm) estimated to be 33 times more likely to fracture than the smallest (21 to 25 mm) aortic valves. Date of manufacture was also associated with risk; valves welded from mid-1981 through March 1984 were more likely to fracture than those manufactured in 1979 and 1980. Body surface area < 1.5 m2 was associated with 1/16 the risk of body surface area > or = 2.0 m2. No other patient factor was strongly associated with the risk of strut fracture.

CONCLUSIONS

Few patient features identifiable in the implant record are predictive of strut fracture. Our analysis supports previous work in identifying valve size, patient age, and date of manufacture as predictors of fracture and adds body surface area. A number of these associations suggest that conditions associated with higher cardiac output may also place patients at increased risk.

Manufacturing characteristics associated with strut fracture in Björk-Shiley 60 degrees Convexo-Concave heart valves

Björk-Shiley Convexo-Concave (CC) valves sometimes experience fracture of the outlet strut. Previously implicated valve characteristics that predict strut fracture include larger valve size, larger opening angle (70 degrees vs 60 degrees), remilling, weld date, and implant in the mitral position. While the associations between risk, size, and opening angle suggest that part of the elevated incidence of strut fracture might be due to the design of the Björk-Shiley valves, only a small fraction of implanted valves have experienced strut fracture. In consequence, previously unexamined variations in the manufacturing process have been suggested as possible factors affecting the failure risk of individual valves; materials, manufacturing steps, quality control, and specific workers have all been put forward as potential explanations for valve-to-valve variation in risk. We conducted a case-control study of CC60 degrees valves implanted in the USA and Canada and manufactured between January 1, 1979 and March 31, 1984. Cases included all verified strut fractures reported to the manufacturer from 1979 through January, 1992. up to 10 controls were selected for each case. Controls were matched to cases on implanting surgeon and were required to have been implanted and functioning at least as long as their respective case valves. We reviewed case and control manufacturing records. There were 150 cases and 1095 surgeon-matched controls. Large mitral valves were at greatest risk of strut fracture; 33mm mitral valves were estimated to be 23 times more likely to fracture than 21-25mm aortic valves. Valves welded in 1979 and 1980 were less likely to fracture than those welded in any other time period; however, no specific manufacturing procedures or personnel were uniquely associated with this time period. Valves with more flexible outlet struts, as determined by the hook deflection and load deflection tests during manufacture, appear to have been at higher risk than valves with more rigid outlet struts. There were three welders who had worked on a sufficient number of valves to allow separate estimation of the risk in the valves they welded. One welder's work was associated with about one-third the risk of valves worked on by the other two. Examination of receiver operating characteristic curves revealed, however, that welder identity added little to the discriminating information already available in the form of valve size and implant position. It is concluded that welder identity and strut flexibility appear to contribute to the risk of outlet strut fracture in Björk-Shiley CC60 degrees valves. Neither of these factors, however, is sufficient to account for much of the previously unexplained variation in risk. No other characteristic measurable in existing manufacturing records appears to predict risk of strut fracture in any useful way.

Continuous measurement of blood flow in the superior sagittal sinus of the lamb

We assessed the validity of recording blood flow in the superior sagittal sinus (Qss) as a measure of cerebral blood flow (CBF). While anesthetized, 10 lambs were instrumented with a transit-time ultrasonic flow probe around the superior sagittal sinus to measure Qss, electrodes to assess sleep state, catheters to measure cerebral perfusion pressure (Pcp), and an occlusive cuff around the common brachiocephalic artery to vary blood pressure. After 72 h recovery, lambs were studied during spontaneous sleep-wake cycles to establish 1) the normal range of Qss and 2) the response rate of Qss to rapid alterations of Pcp. Subsequently, the lambs were reanesthetized, and the measurement of Qss was calibrated and validated. Qss was linearly related to the arterial inflow of 35% of the brain mass (y = 0.5 x + 1.6, r = 0.93, n = 4). Qss was greater in active sleep (154.1 +/- 45.7 ml.min-1 x 100 g-1, mean +/- SD, n = 5) than in quiet sleep (97.1 +/- 40.8 ml.min-1 x 100 g-1) and quiet wakefulness (107 +/- 44.3 ml.min-1 x 100 g-1, P < 0.05). Qss responded rapidly (within one beat) to spontaneous and to induced transient changes in Pcp. We conclude that recording blood flow in the superior sagittal sinus provides a simple, continuous, and quantitative measure of CBF from a defined area of the brain and is appropriate for studying transient changes in the cerebral circulation.

Incidence of symptomatic hand, hip, and knee osteoarthritis among patients in a health maintenance organization

OBJECTIVE

To quantify the incidence of symptomatic hand, hip, and knee osteoarthritis (OA) among members of the Fallon Community Health Plan, a health maintenance organization located in central Massachusetts.

METHODS

Incident OA was defined as the first evidence of OA by radiography (grade > or = 2 on the Kellgren-Lawrence scale of 0-4) plus joint symptoms at the time the radiograph was obtained or up to 1 year before the radiograph was obtained.

RESULTS

The age- and sex-standardized incidence rate for hand OA was 100/100,000 person-years (95% confidence interval [95% CI] 86, 115), for hip OA 88/100,000 person-years (95% CI 75, 101), and for knee OA 240/100,000 person-years (95% CI 218, 262). The incidence of hand, hip, and knee OA increased with age, and women had higher rates than men, especially after age 50. A leveling off or decline occurred for both groups around the age of 80.

CONCLUSION

In a large study of symptomatic OA we observed incidence rates that increased with age. In women ages 70-89, the incidence of knee OA approached 1% per year.

Peptic ulcer and gastrointestinal hemorrhage associated with nonsteroidal anti-inflammatory drug use in patients younger than 65 years. A large health maintenance organization cohort study

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are associated with an elevated risk of peptic ulcer and upper gastrointestinal hemorrhage, but published reports have lacked information on rates of outpatient disease, have concentrated on the elderly, and have not provided comparisons of rates for specific types of NSAIDs.

METHODS

We compared incidence rates of peptic ulcer and upper gastrointestinal hemorrhage in 68 028 people younger than 65 years who used diclofenac sodium, naproxen, piroxicam, or sulindac, and who were members of a network of health maintenance organizations. We reviewed automated insurance claims data and medical records to ascertain cases and included conditions treated on an outpatient basis.

RESULTS

Medical claims data were adequate for crude identification of potential cases, but review of medical records led to rejection of 63% of these, representing either no abnormality or diseases other than peptic ulcer or upper gastrointestinal hemorrhage. Of the total 112 cases, 64 (57%) were treated as outpatients. The crude incidence rate per 1000 person-years in users of any current, recent, or past NSAID was 2.2 and in distant-past users of NSAIDs was 0.75. For diclofenac, naproxen, piroxicam, and sulindac, we found a consistent pattern of decreasing NSAID effects from current to recent to past exposure. The risk of peptic ulcer or upper gastrointestinal hemorrhage was 1.6 cases per 1000 people using NSAIDs.

CONCLUSIONS

Combining use of automated claims records with review of medical records promotes efficiency while maintaining specificity of case ascertainment. This study, with 57% of cases treated as outpatients, had results consistent with other published reports that were based on hospitalized patients. Within the limits of statistical error, the incidence rates of peptic ulcer and upper gastrointestinal hemorrhage appeared to be similar for the various NSAIDs studied.

Discontinuation of antihyperlipidemic drugs--do rates reported in clinical trials reflect rates in primary care settings?

BACKGROUND

Discontinuation rates for drugs used to treat chronic conditions may affect the success of therapy. However, the discontinuation rates reported in clinical trials may not reflect those in primary care settings.

METHODS

We conducted a cohort study using computerized research files and medical records on 2369 new users of antihyperlipidemic therapy at two health maintenance organizations (HMOs) from 1988 through 1990. The rates of drug discontinuation in these primary care settings were compared with the rates reported in clinical trials published from 1975 through 1993, located with the Medline data base.

RESULTS

In the HMOs, the one-year probability of drug discontinuation was 41 percent for bile acid sequestrants (95 percent confidence interval, 38 to 44 percent), 46 percent for niacin (95 percent confidence interval, 42 to 51 percent), 15 percent for lovastatin (95 percent confidence interval, 11 to 19 percent), and 37 percent for gemfibrozil (95 percent confidence interval, 31 to 43 percent). For the bile acid sequestrants, niacin, and gemfibrozil, the risks of discontinuation were substantially higher in the HMOs than in randomized clinical trials, in which the summary estimates of this risk were 31 percent, 4 percent, and 15 percent, respectively, for trials of one year or longer. The rates of discontinuation in open-label studies were similar to those in the HMOs.

CONCLUSIONS

The discontinuation rates reported in randomized clinical trials may not reflect the rates actually observed in primary care settings. The effectiveness and tolerability of antihyperlipidemic medications should be studied further in populations that typically use the agents.

Prolactin-immunoglobulin G complexes from human serum act as costimulatory ligands causing proliferation of malignant B lymphocytes

Several lines of evidence indicate that immunoglobulin-bound prolactin found in human serum is not a conventional complex between an anti-prolactin antibody and prolactin but a different type of association of prolactin with the Fab portion of IgG heavy chains. The complex of prolactin with IgG was purified from serum by anti-human prolactin affinity chromatography and was shown to contain close to 1 mole of N epsilon-(gamma-glutamyl)lysine crosslinks per mole of complex, a characteristic feature in structures crosslinked by transglutaminase. Interestingly, the complex caused a proliferation of cells from a subset of patients with chronic lymphocytic leukemia, while it was inactive in a cell proliferation prolactin bioassay. By contrast, human prolactin stimulated the proliferation of cells in the bioassay but had no effect on the complex-responsive cells from the patients. Competition studies with prolactin and free Fc fragment of IgG demonstrated a necessity for engaging both the prolactin and the immunoglobulin receptors for proliferation. More importantly, competition for the growth response by free prolactin and IgG suggests both possible reasons for the slow growth of this neoplasm as well as avenues for control of the disease.

Toxoplasma infection among pregnant women in Switzerland: a cross-sectional evaluation of regional and age-specific lifetime average annual incidence

A simple generalized linear model of toxoplasmosis incidence has been applied to serologic data from more than 9,000 women who delivered babies in Switzerland. This model, based on an assumption of constant incidence of toxoplasmosis throughout time and ages, yields estimates of incidence rates that show marked contrasts between subgroups of women categorized on the basis of their geographic origin and duration of residence in Switzerland. The patterns observed are in agreement with previously reported data from specific areas. When applied to Swiss resident women of different age groups, the average incidence rate estimates obtained were remarkably similar. This was not the case among the subgroup of Portuguese immigrant women, nor when the model was applied to previously published data from Sweden where toxoplasmosis incidence has clearly decreased in the last 20 years. Although models for the analysis of cross-sectional data involve major simplifying assumptions, it appears that they can yield useful epidemiologic information and that departures from the assumed simplified structure of the data can sometimes be identified.

Long-term survival in the Wolf-Hirschhorn (4p-) syndrome

The clinical features of Wolf-Hirschhorn syndrome are described in a 29-year-old woman who shows severe retardation of growth and development. It is important for health care professionals involved with families in which this condition is present to realize that long-term survival may occur.

Gastroduodenal toxicity of different nonsteroidal antiinflammatory drugs

Although the etiologic relation between nonsteroidal antiinflammatory drug (NSAID) use and gastrointestinal lesions is well documented, newly introduced NSAIDs deserve a fresh examination for their risk/benefit ratio. To estimate the association between consumption of ketorolac and the occurrence of gastroduodenal lesions, we conducted a case-control study. The study population comprised 600 outpatients with a confirmed endoscopic diagnosis of ulcer and erosion in 1991 and 1992 and 6,000 community controls matched by age and sex. We retrieved the prescription history through a computerized prescription monitoring system. We defined exposure to each study drug as "current" (month of endoscopy and preceding month), "recent" (second or third month preceding endoscopy). and "past" (fourth to sixth month preceding endoscopy). Current users of NSAIDs showed a 30% increase in the incidence of gastroduodenal lesions [odds ratio (OR) = 1.3; 95% confidence interval (CI) = 0.98 - 1.8] after adjustment for recent or past use of any NSAID, recent or past gastrotoxic therapy, recent or past use of gastroprotective drugs, and recent or past use of any other drug. Among NSAIDs, ketorolac was the only one showing a distinctly elevated risk of gastroduodenal lesions (OR = 4.2; 95% CI = 1.9-9.4). Current use of any NSAID was associated with almost a doubling of risk for ulcer alone (OR = 1.9; 95% CI = 1.3-3.0); no elevation in risk was found for erosions. The adjusted relative risk for ulcer associated with current use of ketorolac was 9.8 (95% CI = 3.4-28.10. Recent and past use of NSAIDs does not increase the risk of ulcer.(ABSTRACT TRUNCATED AT 250 WORDS)

The infrequency of liver function testing in patients using nonsteroidal anti-inflammatory drugs

OBJECTIVE

To describe the monitoring of liver function for patients using nonsteroidal anti-inflammatory drugs (NSAIDs), we reviewed the patterns of liver function testing in a medium-sized health maintenance organization.

METHODS

We examined the interval between start of therapy and first performance of a liver function test during courses of therapy of the NSAIDs diclofenac sodium, naproxen and naproxen sodium, and piroxicam. For comparison, we also studied courses of lovastatin as a "positive control," in which the anticipated frequency of liver function testing was high.

RESULTS

The frequency of liver function tests in patients using NSAIDs was generally low, although testing was more common in patients who used diclofenac. The probability of liver function testing was higher for patients treated in recent calendar years, for patients treated by rheumatologists, for patients who previously used NSAIDs, and for patients who had undergone a liver function test sometime in the 6 months preceding the onset of therapy.

CONCLUSION

Physicians ordered liver function tests less frequently than recommended, but the observed testing patterns appear rational in light of the very low reported frequency of serious hepatic disease in large, monitored populations of patients using NSAIDs.

Circulating fibroblast growth factor-like autoantibodies in two patients with multiple endocrine neoplasia type 1 and prolactinoma

Basic fibroblast growth factor (bFGF) is a potent endothelial cell mitogen found in a variety of normal and tumor tissues. bFGF lacks a classical amino-terminal signal sequence and is not readily detectable in plasma from normal subjects. In earlier studies we showed increased bFGF-like mitogenic activity for parathyroid-derived endothelial cells and (increased) bFGF immunoreactivity (0.24-1.28 ng/mL) in plasma of subjects with multiple endocrine neoplasia type 1 (MEN-1). In the present study we examined the proliferative activity of MEN-1 and normal plasmas (applied to protein-A columns) in calf pulmonary artery endothelial cells. Protein-A-eluted activity in plasma from MEN-1 prolactinoma plasma exceeded activity from normal and MEN-1 nonprolactinoma plasma in three of eight MEN-1 subjects with untreated or recurrent prolactinoma. Protein-A-eluted active fractions from MEN-1 prolactinoma plasma had several properties of an immunoglobulin G, including affinity for antihuman immunoglobulin G (IgG) agarose, sensitivity to thiols, and (prepared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions) apparent mol wt corresponding to those of the heavy and light chains of IgG. The IgG fraction of MEN-1 prolactinoma plasma had far more activity in endothelial cells than did optimal concentrations of known growth factors or conditioned medium from prolactinoma cells. Endothelial cell bioactivity in protein-A-eluted fractions from MEN-1 prolactinoma plasma was neutralized 70% by rabbit antibodies to intact bFGF. These results imply novel growth stimulatory bFGF-like autoantibodies in a subset of MEN-1 patients with prolactinoma.

Examination of the early 'learning curve' for transcatheter closure of patent ductus arteriosus using the Rashkind occluder. PDA Closure Comparative Study Group

BACKGROUND

Results of transcatheter implantation of the Rashkind double umbrella occluder for treatment of patent ductus arteriosus (PDA) have improved over time. We evaluated factors associated with changes in outcomes seen in the early clinical experience with this device.

METHODS AND RESULTS

We reviewed records of otherwise healthy pediatric patients undergoing occluder implantation for isolated PDA between 1982 and 1987 at six major US and Canadian referral centers. Logistic regression was used to assess the impact of ductal size, patient age and weight, calendar time, prior intrainstitutional occluder experience, and residual center effects on closure rates. There were no study deaths. Of 180 occluder placement attempts, 76.7% (95% confidence limits = 70.5%, 83.0%) produced PDA closure by auscultation at 14-month cardiology follow-up or its equivalent. Success probabilities increased in a linear fashion as ductus size decreased, ranging from 41.7% for large (4.1 to 9.0-mm) ducts to 89.4% for small (1.5 to 2.5-mm) lesions. PDA occluder closure rates also improved over time, increasing from 47.4% in 1982-1983 to 84.6% in 1986 and 83.1% in 1987. Multivariate logistic regression indicated that improved outcomes were mainly attributable to decrease in the size of treated ducts over time. Independent of this patient selection, improvements in outcome were less strongly associated with cumulative intracenter experience, calendar time, and age.

CONCLUSIONS

Increasing closure rates seen over time primarily reflected more judicious selection of patients as experience accumulated. However, other factors also contributed to the observed trends. An analysis of current treatment results would be of considerable interest.

Effects of estrogen on thermoregulatory evaporation in rats exposed to heat

The purpose of this study was to determine the effects of estrogen (E2) replacement on thermoregulation in ovariectomized rats exposed to heat. Female Sprague-Dawley rats were ovariectomized and splenectomized and implanted with a temperature-sensitive transmitter. Each rat was studied when E2 treated (after an E2 pellet implant) and untreated. Animals were divided into two groups with opposite order of treatment and were studied over a 9-wk period. Measurements of body core temperature (Tc) and evaporative water loss (EWL) were made on unrestrained animals resting at 38 degrees C air temperature. E2-treated animals increased EWL at all levels of Tc, reduced the threshold Tc for onset of saliva spreading, and regulated Tc at a lower level during heat exposure. E2 treatment elevated plasma E2 and reduced hematocrit but did not affect plasma osmolality. These effects of E2 on evaporative cooling and Tc in heat-stressed rats are similar to those that have been reported in human females. The mechanisms of the thermoregulatory effects of E2 remain to be studied.

Phosphorylated and nonphosphorylated Prolactin isoforms

Specific posttranslational modifications o f monomer PRL produce a number of hormone variants. This review describes the current state of knowledge for the nonphosphorylated and phosphorylated 24-kD monomer forms. Of particular interest and significance for our future understanding of PRL endocrinology are the studies showing their differential release in response to different physiologic signals and their different activities in target tissues. In at least two target tissues, the monophosphorylated variant seems to act as an antagonist to the unmodified hormone.

The lag time between onset of symptoms and diagnosis of rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) may be biologically reversible if treated in the first several months, yet it is unknown whether patients are diagnosed that early. We investigated the lag time between symptom onset and diagnosis of RA in a population with excellent access to rheumatology care.

METHODS

Using review of medical records, we evaluated all patients newly diagnosed as having RA from 1987 through 1990, at a health maintenance organization in central Massachusetts. Total lag time from symptom onset to first definite diagnosis was divided into medical encounter lag time (from symptom onset to first medical encounter) and diagnosis lag time (from first medical encounter to diagnosis).

RESULTS

The median total lag time was 36 weeks (range 4 weeks to > 10 years). The median medical encounter lag time was 4 weeks (not all patients included in the analysis). The median diagnosis lag time was 18 weeks. Diagnosis lag time was shorter for patients with progressive disease and positive rheumatoid factor on the initial test. Of 25 patients with symmetric arthritis and positive rheumatoid factor, only 5 (20%) were diagnosed within 2 months, and 10 (40%) were diagnosed more than 6 months after symptom onset.

CONCLUSION

RA diagnosis is usually delayed for several months after symptoms begin, in large part because of delay in diagnosis by the physician. Thus, the goal of initiating treatment extremely early may be unrealistic for most patients.