Atresia Hymenalis with Haematometrocolpos: A Benefit of Teaching a Case Series and Review of the Literature.

We present four cases of atresia hymenalis with resultant haematometrocolpos diagnosed in quick succession in the emergency department with a literature review.

Inhaled nitric oxide in preterm infants with prolonged preterm rupture of the membranes: a case series.

The available evidence does not support the routine use of inhaled nitric oxide (iNO) in the care of premature infants. We present a case series of 22 preterm infants born after prolonged preterm premature rupture of membranes and oligohydramnios with respiratory failure. Oxygenation index decreased significantly after commencement of iNO.

Initial assessment of jaundice in otherwise healthy infants--a comparison of methods in two postnatal units.

Transcutaneous bilirubin (TcB) has the potential to reduce total serum bilirubin (TS) sampling. The principal aim of this study was to determine and compare the number of initial TSB samples (TSBs) in two postnatal units (hospitals A & B) whereby hospital A used TcB and hospital B did not. A secondary aim was to determine the clinical factors that led to initial TSBs exceeding exchange transfusion level in both hospitals. Results demonstrated both hospitals had similar populations and patient numbers following selection criteria. 1645 neonates (10.4%) had one or more TSBs performed in hospital A, versus 2373 neonates (15.1%) in hospital B (p < 0.01). Fourteen neonates in hospital A and 3 neonates in hospital B had initial TSBs above exchange transfusion level. For neonates with TSBs above exchange, preventable factors related to earlier testing and follow up. In routine clinical practice, TcB is associated with a significantly reduced number of TSB measurements. TSB levels above exchange transfusion are linked to preventable factors, in otherwise healthy neonates.

The initiation codon affects ribosome binding and translational efficiency in Escherichia coli of cI mRNA with or without the 5' untranslated leader.

Translational efficiency of an AUG, CUG, GUG, or UUG initiation codon was measured for the naturally leaderless cI mRNA from bacteriophage lambda. In a cI-lacZ translational fusion, only AUG supported a high level of expression; GUG supported a low level of expression, while UUG and CUG expression was barely above background levels. Addition of an untranslated lac leader and Shine-Dalgarno sequence to cI increased expression but still showed a dependence on an AUG for maximum expression. cI-lacZ mRNA with an AUG initiation codon showed a greater in vitro ribosome binding strength and a higher level of full-length in vivo mRNA, suggesting that the initiation codon is an important determinant of ribosome binding strength and translational efficiency for mRNA with or without the 5' untranslated leader.

Regional distribution and cellular expression of tryptophan hydroxylase messenger RNA in postmortem human brainstem and pineal gland.

The characterization and cellular localization of tryptophan hydroxylase mRNA in the human brainstem and pineal gland were investigated by using northern blot analysis and in situ hybridization histochemistry. Northern analysis of human pineal gland revealed the presence of two mRNA species that were absent in RNA isolated from human raphe. In situ hybridization experiments revealed very dense hybridization signal corresponding to tryptophan hydroxylase mRNA in cells throughout the pineal gland. In contrast, tryptophan hydroxylase mRNA was heterogeneously distributed in neurons in the dorsal and median raphe nuclei. Within the dorsal raphe, the ventrolateral and interfascicular subnuclei contained the greatest number of tryptophan hydroxylase mRNA-positive neurons. Also, the cellular concentration of tryptophan hydroxylase mRNA varied widely within the dorsal and median raphe. Comparison of the cellular concentration of tryptophan hydroxylase mRNA between the pineal gland and the raphe nuclei revealed an 11- and 46-fold greater average grain density of tryptophan hydroxylase mRNA positive cells in the pineal gland compared with the dorsal and median raphe, respectively. These findings are the first to demonstrate the cellular localization of tryptophan hydroxylase mRNA in the human brain and pineal gland as well as heterogeneity in the cellular concentration within and between these tissues.

Naive beliefs about breast cancer risk.

We examined the beliefs women have about their risk of breast cancer. Participants were 86 women, ages 18 to 90, with and without a family history of breast cancer. They were interviewed individually about their risk and their beliefs about risk factors for breast cancer. The results showed that participants form their risk estimates primarily from the absence or presence of a family history of breast cancer. When asked to compare their risk with the risk of others, only participants without a family history viewed their chances of getting breast cancer as lower than the chances of others. On an absolute risk measure, all participants overestimated their risk. Different risk measures can lead to different conclusions about how women perceive their risk. In addition, the nearly exclusive focus of women on family history may create difficulties for genetic counselors providing information about breast cancer risk.

A descriptive study of breast cancer worry.

Women with (n = 65) and without (n = 70) a family history of breast cancer reported on their thoughts and concern about the disease. Measures were taken across a 1-month interval and at a 1-year follow-up. Reported screening behaviors were also measured at baseline and the 1-year follow-up. Worry dissipated over time, suggesting that worry levels are affected by the measurement context. However, women with a family history of the disease maintained greater worry than those without such a history, suggesting that they may be chronically worried about the disease. Thinking and worrying about breast cancer were both modestly and positively related to the frequency of screening behaviors, suggesting that some kinds of worry can motivate self-protective behavior.

Avidity of technetium 99m glucarate for the necrotic myocardium: in vivo and in vitro assessment.

BACKGROUND: Similar to other 99mTc-based infarct-avid agents, 99mTc-glucarate localizes in myocardial infarcts. Whether severely ischemic viable myocytes sequester 99mTc-glucarate is uncertain. To assess the infarct specificity, in vitro and in vivo studies were performed. METHODS AND RESULTS: H9C2 embryonic rat cardiocytes cultured under normoxia (N) or hypoxia (H) for 24 hours in 7.5 muCi 99mTc-glucarate were compared with necrotic cardiocytes. Mean H/N ratio (3.0 +/- 0.004, mean +/- SD) was significantly less than that of the necrotic/N ratio (39.9 +/- 6.5, p < 0.01). Reperfused myocardial infarction (MI) in 4 dogs confirmed by 201Tl (0.5 to 1.0 mCi) scintigraphy were imaged serially with simultaneously injected mixture of 99mTc-glucarate and 111In-antimyosin Fab. Infarcts were detected scintigraphically within 4 to 10 minutes with 99mTc-glucarate. 111In-antimyosin required more than 1 hour. Myocardial distribution at 5 hours showed a direct correlation between 99mTc-glucarate and 111In-antimyosin uptake (r = 0.99, p < 0.0001). Both 99mTc-glucarate (r = -0.777, p < 0.0001) and 111In-antimyosin (r = -0.775, p < 0.0001) were inversely related to 201Tl distribution. CONCLUSIONS: The near perfect correlation between 99mTc-glucarate and 111In-antimyosin uptake (r = 0.99) in reperfused canine MI and the insignificant glucarate uptake by viable cardiocytes in vitro attest to the avidity of 99mTc-glucarate for the necrotic myocardium and favor its use as a specific early marker of myocyte necrosis in acute MI.

Gamma imaging of atherosclerotic lesions: the role of antibody affinity in in vivo target localization.

BACKGROUND: Monoclonal antibodies are attractive agents for noninvasive localization of various cardiovascular disorders. Because proliferating intimal smooth muscle cells are important components of atherosclerotic lesions, radiolabeled antibody Z2D3 specific for proliferating smooth muscle cells has been used for immunoscintigraphic localization of experimental atherosclerotic lesions. This study was undertaken to assess the role of antibody affinity in optimization of immunoscintigraphic localization of these lesions. Z2D3 belongs to the immunoglobulin (Ig) M class of antibodies. For immunoscintigraphic studies, attempts were made to prepare F(ab')2 or Fab fragments from the parent cell line. Fragmentation of Z2D3-IgM or its two subclones (B7 and 2B12) was not possible; therefore the parent hybridoma line was subjected to class switching. Cell lines 5C5 and 3E5 secreted antibody of the IgG1 subclass. The Z2D3-IgG1 antibodies were enzymatically digested to provide F(ab')2. Because of a tenfold loss of immunoreactivity of these class-switched antibodies, the parent clone was subsequently genetically engineered to obtain a mouse/human chimeric antibody with human IgG1 constant region. F(ab')2 of Z2D3-73.30 chimeric antibody retained the immunoreactivity relative to the original Z2D3-IgM. Radiolabeled murine and chimeric F(ab')2 fragments were used to assess the role of affinity in gamma scintigraphic visualization of experimental atherosclerotic lesions. METHODS AND RESULTS: Experimental atherosclerotic lesions were induced in 19 rabbits by abdominal aortic balloon deendothelialization followed by a hyperlipidemic diet for 12 weeks. 111In-labeled chimeric high-affinity Z2D3 F(ab')2 fragments (111In-Hi.aff Z2D3) were administered in four animals. Uptake was compared with 111In-labeled F(ab')2 of nonspecific human IgG1 (n = 4), murine low-affinity Z2D3-5C5 (111In-Lo.aff Z2D3; n = 4), nonspecific murine IgG1 monoclonal antibodies (n = 4), and 123I-labeled murine low-affinity Z2D3-3E5 (n = 3). Atherosclerotic lesions were visualized 48 hours after administration of the chimeric Hi.aff-Z2D3 antibody in all animals. Lesions were not visualized in rabbits injected with Lo.aff-Z2D3 or murine or human nonspecific antibodies. Mean percent injected dose per gram in the lesion was significantly higher with the 111In-Hi.aff-Z2D3 (0.112% +/- 0.024%) compared with 111In-Lo.aff-Z2D3 (0.037% +/- 0.005%; p = 0.03), human nonspecific (0.027% +/- 0.004%; p = 0.01), or murine nonspecific antibodies (0.006% +/- 0.001%; p = 0.0004). Nonspecific activity in unballooned thoracic aortic segments (normal) was comparable in the 111In-Hi.aff-Z2D3 (0.019 +/- 0.003) and the 111In-Lo.aff-Z2D3 (0.011% +/- 0.005%; p = 0.3) antibodies. The lesion activities of the Lo.aff-Z2D3 labeled with 111In (0.037 +/- 0.005) or 123I (0.034 +/- 0.007; p = 0.71) were similar regardless of the radioisotopes used for labeling. CONCLUSIONS: Our study demonstrates that the specificity of an antibody for the target antigen in the atheroma is a necessary condition for in vivo targeting. However, high enough affinity of an antibody is an essential component for noninvasive diagnostic visualization of experimental atherosclerotic lesions.

In vivo targeting of acute myocardial infarction with negative-charge, polymer-modified antimyosin antibody: use of different cross-linkers.

BACKGROUND: Cell surfaces and intercellular matrixes contain acidic residues, making them negatively charged. Antibodies are basic, positively charged glycoproteins. Therefore the potential for nonspecific ionic interaction exists, which could increase the background activity. Modification of antibodies with negatively charge-modified polymers have been shown to reduce this nonspecific background activity. This study was performed to investigate the appropriateness of different cross-linkers used covalently to link the chelating negatively charge-modified polylysine to antimyosin Fab (AM-Fab). The cross-linking was performed through peptide (AM-I) or thioether (AM-II) bonds. The in vitro evaluation of the immunointegrity and the in vivo assessment were performed to investigate the potential for reduction of nontarget background activity. Furthermore, the role of the charge of the polymers (whether completely negatively charge modified by succinylation [AM-IIs] or only partially negatively charge modified [AM-IIns]) was also assessed. METHODS AND RESULTS: All polymer-modified preparations (AM-I, AM-IIs, and AM-IIns) retained the immunoreactivities relative to the unmodified or conventional diethylenetriaminepentaacetic acid-coupled AM-Fab as assessed by radioimmunoassay or enzyme-linked immunosorbent assay. These polymer-modified preparations labeled with 111In were assessed in 13 rabbits with acute experimental myocardial infarction. Acute infarcts were produced by 40 minutes of left anterior descending coronary artery occlusion followed by reperfusion. At between 10 and 30 minutes of reperfusion, 10.4 +/- 1.8 mBq 111In-AM-I (10 to 20 micrograms; n = 7) or 11.4 +/- 2.3 mBq 111In-AM-II (n or ns) (20 to 25 micrograms; n = 6) was administered intravenously. Gamma imaging was performed in the left lateral position and arterial blood samples were withdrawn serially for the next 3 hours. At the end of the final imaging session, AM-I uptake was determined to be 1.09% +/- 0.11% (mean percent injected dose per gram myocardium +/- SEM) in 20 infarcted myocardial segments from seven rabbits, compared with 0.031% +/- 0.003% in 20 normal myocardial segments (infarct/normal myocardial ratio 53.9 +/- 18.41). The mean percent injected dose of 111In-labeled thioether-linked AM-Fab preparations in nine infarcted myocardial segments from each group was 0.067% +/- 0.008% (infarct/normal myocardial ratio 9.0 +/- 1.5) and 0.144% +/- 0.011% (infarct/normal myocardial ratio 10.2 +/- 1.9) with AM-IIs (n = 3) and AM-IIns (n = 3), respectively (p < 0.0001). The non-target organ distribution of the AM-I and AM-IIs was similar. AM-IIns preparation resulted in high non-target organ activities. CONCLUSIONS: This study shows that the charge of the antibody can be manipulated favorably by cross-linking with negatively charged polymers, which results in the reduced in vivo non-target organ activities. Charge modification does not adversely affect the apparent affinity of the antibody. However, the type of cross-linkers used may significantly influence the in vivo stability of the modified antibody preparations for target organ visualization. These data may find potential application in future clinical imaging protocols.

Evaluation of myocardial infarct size before and after reperfusion: dual-tracer imaging with radiolabeled antimyosin antibody.

UNLABELLED: Antimyosin antibody is a specific marker of myocardial necrosis that is based on the loss of integrity of the sarcolemmal membrane. Because antimyosin can be labeled with several different radiotracers, gamma imaging performed with antimyosin labeled with two different radionuclides can be used to quantify infarct size before and after an intervention such as reperfusion. METHODS: Twelve open-chested anesthetized dogs were evaluated both at the end of 1.5 hr of occlusion of the left anterior descending coronary artery and following reperfusion. Antimyosin Fab radiolabeled with either 123I or 111In was injected by intracoronary administration over 3 min at the end of the occlusion interval, and the coronary sinus was drained continuously for 7 min to prevent recirculation of the antibody. One hour after reperfusion, a second injection of antimyosin Fab (labeled with a different isotope from the first) was administered as before. Six dogs were given intracoronary trifluoperazine (150 micrograms/kg of body weight) simultaneously with reperfusion, and another six dogs received saline as the control. The infarct size in grams before and after reperfusion was assessed by antimyosin antibody uptake in ex vivo images of 1-cm thick slices of the hearts. The mean infarct sizes before (W1) and after (W2) reperfusion were then calculated as the percent of infarcted myocardium/ventricular myocardial mass. RESULTS: There was a significant increase in the mean percent infarct size after reperfusion in the control group (W2 = 16.73 +/- 4.0, W1 = 14.92 +/- 3.88; p = 0.029). The mean infarct size was uniformly smaller with trifluoperazine intervention (W2 = 12.33 +/- 2.03, W1 = 16.34 +/- 2.78; p = 0.004). The difference between the mean change in the infarct sizes in the two groups was highly significant (p = 0.002). CONCLUSION: Dual imaging of the extent of myocardial necrosis before and after an intervention (reperfusion) in the same animal demonstrated the utility of antimyosin imaging to document changes in the extent of necrosis.

Targeting of macromolecular carriers and liposomes by antibodies to myosin heavy chain.

Macromolecular carriers and liposomes were covalently coupled to monoclonal antibodies against cardiac myosin heavy chain. Deferoxamine-modified polymers bound tightly with 67Ga and 68Ga radioisotopes. Ternary deferoxamine-polylysine antibody conjugates specifically targeted the radioisotopes to a myosin-coated microplate. Scatchard analysis revealed a high affinity of the conjugate for the target with a Kas of approximately 10(8) M-1. Liposomes that contained immobilized antimyosin antibodies were targeted specifically to the myosin-coated plate. Additional coating of these liposomes with polyethylene glycol reduced specific binding to the target in vitro. However, because of the presence of polyethylene glycol on the surface of liposomes, these liposomes had a long half-life and slowly cleared from the blood-stream after intravenous injection. These immunoliposomes showed up to 16- to 18-fold specific localization to the necrotic areas of the myocardium in rabbits with experimental infarction.

Gamma imaging with negatively charge-modified monoclonal antibody: modification with synthetic polymers.

Antimyosin Fab has been modified to carry highly negatively charged synthetic polymers containing DTPAs (DTPA-PL) as chelating agents, of starting molecular weights 3.3 and 17 kD. The immunoreactivities of the modified antibodies were unaffected by the modification procedure. The isoelectric points (PI) of unmodified antimyosin (AM) Fab (PI range 7-9, Mr = 52kD) were changed to PIs predominantly between 4 and 5 (Mr = 59 kD for DTPA-PL3.3kD-AM-Fab and 67kD for DTPA-PL17kD-AM-Fab). These AM-Fab preparations were tested for specific target localization and visualization in vivo in an experimental canine model of acute myocardial infarction. The charge-modified 111In-labeled AM-Fab preparations showed enhanced target (necrotic myocardium) visualization within 30 min of intravenous infusion and decreased background activity in normal myocardium (mean %ID/g +/- s.e.m., 0.0076 +/- 0.0006, n = 164, and 0.0056 +/- 0.0004, n = 92, for 111In-DTPA-PL3.3kD- and DTPA-PL17kD-AM-Fab respectively) relative to conventional 111In-DTPA-AM-Fab (0.0263 +/- 0.0037, n = 135) (p less than 0.001) or radioiodinated AM-Fab (0.0098 +/- 0.0006, n = 256) (p less than or equal to 0.001). Furthermore, the concentration of negatively charged 111In-labeled antimyosin Fab decreased in non-target organs such as the liver and kidneys. In diagnostic and therapeutic applications, charge-modified macromolecules may improve target localization and reduce non-target organ activity.

Use of isothiocyanatobenzyl-DTPA derivatized monoclonal antimyosin fab for enhanced in vivo target localization.

Monoclonal antimyosin Fab (AM-Fab) was radiolabeled with 111In via a new bifunctional chelating agent, isothiocyanatobenzyl-DTPA (SCN-DTPA), and used to visualize acute reperfused experimental myocardial infarction. Antibody localization was compared to 201Tl (0.6 mCi) distribution in nine animals. Each animal was injected intravenously with 0.5 mCi of 111In-SCN-DTPA AM-Fab preparations (Prep 1 [n = 5] and 2 [n = 4]). The biodistribution was compared to that of 111In-labeled conventional bicyclic anhydride DTPA-AM-Fab (n = 5). 111In-SCN-DTPA AM-Fab Prep 1 (lowest specific activity) showed highest specific target localization (31.6 +/- 3.5, MEAN infarct[0-20% Tl-201] to normal ration +/- SE) and lowest hepatic sequestration (0.0108 +/- 0.002% ID/g). Prep 2 showed similar infarct localization (18.4 +/- 1.2) to control 111In-DTPA AM-Fab (16.9 +/- 1.1), but had higher hepatic activity (0.0326 +/- 0.014 and 0.0267 +/- 0.006 respectively). This difference in in vivo localization occurred despite the lack of changes in in vitro immunoreactivities of the AM-Fab preparations. The enhanced target localization with minimal hepatic activity may permit a more sensitive diagnostic application of 111In-labeled AM-Fab in future clinical studies.