Pancreas dorsal lobe agenesis and abnormal islets of Langerhans in Hlxb9-deficient mice.

In most mammals the pancreas develops from the foregut endoderm as ventral and dorsal buds. These buds fuse and develop into a complex organ composed of endocrine, exocrine and ductal components. This developmental process depends upon an integrated network of transcription factors. Gene targeting experiments have revealed critical roles for Pdx1, Isl1, Pax4, Pax6 and Nkx2-2 (refs 3,4,5,6,7, 8,9,10). The homeobox gene HLXB9 (encoding HB9) is prominently expressed in adult human pancreas, although its role in pancreas development and function is unknown. To facilitate its study, we isolated the mouse HLXB9 orthologue, Hlxb9. During mouse development, the dorsal and ventral pancreatic buds and mature beta-cells in the islets of Langerhans express Hlxb9. In mice homologous for a null mutation of Hlxb9, the dorsal lobe of the pancreas fails to develop. The remnant Hlxb9-/- pancreas has small islets of Langerhans with reduced numbers of insulin-producing beta-cells. Hlxb9-/- beta-cells express low levels of the glucose transporter Glut2 and homeodomain factor Nkx 6-1. Thus, Hlxb9 is key to normal pancreas development and function.

Single-photon emission computed tomography gallium imaging versus computed tomography: predictive value in patients undergoing high-dose chemotherapy and autologous stem-cell transplantation for non-Hodgkin's lymphoma.

PURPOSE: To evaluate the predictive value of computed tomography (CT) scanning and single-photon emission computed tomography (SPECT) gallium (Ga) scanning in the disease-free survival of patients receiving high-dose chemotherapy and autologous stem-cell transplantation for non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: One hundred forty-three patients undergoing transplant for NHL underwent CT scanning of chest, abdomen, and pelvis, and a SPECT Ga scan before transplantation and at day + 100 after transplant. The failure-free survival (FFS) by scan result was analyzed. RESULTS: In the diffuse aggressive lymphoma patients, the 1-year FFS for patients having a positive SPECT Ga scan at day + 100 was 15% compared with a 3-year FFS of 47% for those with a negative scan (P < .001). Patients with a positive CT scan at day + 100 had a 36% 3-year FFS, and those with a negative CT scan had a 39% 3-year FFS (P = not significant [NS]). An analysis of the combination of CT scan and SPECT Ga scan results at day + 100 posttransplant demonstrated a 3-year FFS of 14% if they were both abnormal; if the CT was positive and Ga was negative, the 3-year FFS was 68%; positive Ga with a negative CT was 25%; and both negative was 34% (P = .0015). For the patients with follicular NHL, those with a positive SPECT Ga at day + 100 had a 14% 1-year FFS compared with those with a negative scan, who had a 45% 3-year FFS (P < .001). In the follicular NHL patients, the 3-year FFS of those with a positive CT was 17% compared with a 64% 3-year FFS for patients with a negative CT scan (P < .001). CONCLUSION: The use of SPECT Ga scan at day + 100 posttransplant for evaluation of disease activity in patients with diffuse aggressive NHL was highly predictive of eventual outcome and was more predictive than the CT scan results. However, for patients with follicular NHL, the addition of SPECT Ga scanning to CT scanning did not add substantially to the evaluation of transplant outcome.

Palliation of pain associated with metastatic bone cancer using samarium-153 lexidronam: a double-blind placebo-controlled clinical trial.

PURPOSE: To evaluate the effectiveness and safety of samarium-153 (153Sm) lexidronam (EDTMP) in a double-blind, placebo-controlled study. PATIENTS AND METHODS: Patients with painful bone metastases secondary to a variety of primary malignancies were randomized to receive 153Sm-EDTMP 0.5 or 1.0 mCi/kg, or placebo. Treatment was unblinded for patients who did not respond by week 4, with those who had received placebo eligible to receive 1.0 mCi/kg of active drug in an open-label manner. Patient and physician evaluations were used to assess pain relief, as was concurrent change in opioid analgesia. RESULTS: One hundred eighteen patients were enrolled onto the study. Patients who received 1.0 mCi/kg of active drug had significant reductions in pain during each of the first 4 weeks in both patient-rated and physician-rated evaluations. Pain relief was observed in 62% to 72% of those who received the 1.O-mCi/kg dose during the first 4 weeks, with marked or complete relief noted in 31% by week 4. Persistence of pain relief was seen through week 16 in 43% of patients who received 1.0 mCi/kg, of active drug. A significant correlation (P = .01) was observed between reductions in opioid analgesic use and pain scores only for those patients who received 1.0 mCi/kg 153Sm-EDTMP. Bone marrow suppression was mild, reversible, and not associated with grade 4 toxicity. CONCLUSION: A single dose of 1.0 mCi/kg of 153Sm-EDTMP provided relief from pain associated with bone metastases. Pain relief was observed within 1 week of administration and persisted until at least week 16 in the majority of patients who responded.

Platelet-activating factor biosynthesis induced by various stimuli in human HaCaT keratinocytes.

Platelet-activating factor (PAF) is a potent inflammatory mediator that is thought to play a role in cutaneous inflammation. These studies used mass spectrometry to examine the molecular species of PAF precursor glycerophosphocholine lipids (GPC) as well as the biosynthesis of PAF and other sn-2 acetyl-GPC in a human keratinocyte-derived cell line (HaCaT keratinocytes). Approximately 28% of HaCaT keratinocyte GPC consisted of 1-alkyl species, and the relative amounts of the sn-1 alkyl constituents of the PAF precursor 1-alkyl-2-acyl-GPC were as follows: hexadecyl > octadecenyl > octadecyl. Ionophore (A23187)-stimulated HaCaT keratinocytes synthesized both PAF (1-hexadecyl, 1-octadecenyl, and 1-octadecyl species) and less potent 1-acyl analogs (1-palmitoyl, 1-oleoyl, and 1-stearoyl species). PAF production was rapid and maximal by 10 min. The major species of sn-2acetyl-GPC at 2.5 min were 1-hexadecyl-2-acetyl-GPC (2.2 ng/10(6) cells) and 1-palmitoyl-2-acetyl-GPC (2.4 ng/10(6) cells). HaCaT keratinocytes also synthesized PAF and 1-acyl PAF analogs when stimulated with the peptide growth factor endothelin-1 and the nonhydrolyzable PAF receptor agonist carbamyl-PAF. Both 1-hexadecyl-2- acetyl-GPC and 1-palmitoyl-2-acetyl-GPC stimulated intracellular calcium mobilization in HaCaT cells, indicating that these sn-2 acetyl-GPC act in autocrine fashion. These studies revealed that the human keratinocyte-derived cell line HaCaT can synthesize significant amounts of PAF and 1-acyl analogs in vitro from both nonspecific (A23187) and specific (endothelin-1, carbamyl-PAF) stimulation, suggesting a role for this inflammatory lipid mediator in keratinocyte pathophysiology.

Bioactive phospholipid oxidation products.

Oxidation of phospholipids results in chain-shortened fragments and oxygenated derivatives of polyunsaturated sn-2 fatty acyl residues, generating a myriad of phospholipid products. Certain oxidation products of phosphatidylcholine bind to and activate the human receptor for PAF, and these PAF-like lipids are potent, selective inflammatory mediators. Formation of PAF-like lipids is nonenzymatic and so their accumulation is unregulated. PAF-like lipids are produced in vivo in response to oxidative stresses and are responsible for attendant acute inflammatory responses. PAF-like lipids almost exclusively contain an ether-linked alkyl residue at the sn-1 position of the phosphatidylcholine backbone and molecular identification of these is facilitated by phospholipase A(1) treatment to remove the bulk of the inactive phospholipids. The identity of biologically active species generated by oxidative fragmentation and oxidation can be elucidated by understanding relevant reactions leading to the formation of PAF-like lipids, and then their structure can be established by tandem mass spectrometry and chemical synthesis.

Indium-111-leukocyte imaging: a case of peritonitis mimicking inflammatory bowel disease.

Leukocytes labeled with 99mTc-HMPAO and 111In have been used extensively in imaging inflammatory disorders, including inflammatory bowel disease (IBD), which has the appearance of tubular bowel activity. Peritonitis is inflammation of the serosal surfaces lining the peritoneal cavity which envelopes the bowel, giving a pattern of diffuse abdominal uptake on imaging. We present a case of an elderly man with surgically and pathologically confirmed peritonitis whose preoperative leukocyte scan mimicked the findings of IBD. Our findings suggest that diffuse peritonitis can mimic IBD on an 111In-leukocyte scan.

Plasma D-dimer: a useful tool for evaluating suspected pulmonary embolus.

Although ventilation-perfusion lung scanning is widely used in evaluating patients with suspected pulmonary embolus, additional rapid screening tests are needed to supplement scintigraphy in patients in whom the scan is indeterminate or the scan results are discordant with clinical suspicion. D-dimer is a fibrin degradation product which should be elevated in the presence of intravascular coagulation. We prospectively studied patients referred for lung scanning by obtaining a plasma D-dimer latex agglutination assay at the time of the scan. Of 64 patients who had pulmonary angiography to confirm the diagnosis, 16 were positive for pulmonary embolus and only one had a normal D-dimer. The D-dimer was normal in 27 of 48 patients without embolus and elevated in 21. Although an elevated D-dimer level is a nonspecific finding, we conclude that a normal D-dimer is a good negative predictor for pulmonary embolus, with a negative predictive value of 0.97.

SPECT imaging of fluorine-18.

UNLABELLED: The objective of this work was to determine the potential clinical usefulness of SPECT to image 511-keV annihilation photons. METHODS: A triple-headed gamma camera equipped with ultra-high-energy collimators was used to image 18F. Sensitivity measurements were carried out and the FWHM and FWTM were determined in air and for a unit-density scattering medium. Additionally, tomographic phantom studies were acquired to evaluate image quality. RESULTS: The sensitivities of the three cameras were, for all practical purposes, identical. At a source-to-collimator distance of 100 mm, the FWHM and FWTM were 13 and 29 mm, respectively. A tomographic phantom study demonstrated that spheres with a diameter of 20 mm were well resolved when filled with 18F activity and placed inside a water-filled phantom. CONCLUSION: The triple-headed SPECT camera in this investigation is a practical means of acquiring tomographic 18F images. The reconstructed slices were of sufficient quality to be of value in some clinical studies.

Patient-specific dosimetry of indium-111- and yttrium-90-labeled monoclonal antibody CC49.

UNLABELLED: The objective of this work was to develop patient-specific dosimetry for patients with metastatic gastrointestinal tract cancers who received 111In-CC49 IgG for imaging before therapy with 90Y-CC49 IgG. METHODS: Whole-body imaging of 12 patients, who received 111-185 MBq (3-5 mCi) of 111In-CC49, commenced in < 2 hr postinfusion and was continued daily for 4-5 days. SPECT data were acquired at 24 and 72 hr to determine the range of 111In-CC49 activity concentrations in tumors and normal organs. Time-activity curves were generated from the image data and scaled from 111In-CC49 to 90Y-CC49 for dosimetric purposes. Absorbed-dose calculations for 90Y-CC49 included the mean and range in tumor and normal organs. Computed 90Y-CC49 activity concentrations were compared with measurements on 10 needle biopsies of normal liver and four tumor biopsies. RESULTS: In 9 of 10 normal liver samples, the range of computed 90Y-CC49 activity concentrations bracketed measured values. This was also the case for 3 of 4 tumor biopsies. Absorbed-dose calculations for 90Y-CC49 were based on patients' images and activities in tissue samples and, hence, were patient-specific. CONCLUSION: For the radiolabeled antibody preparations used in this study, quantitative imaging of 111In-CC49 provided the data required for 90Y-CC49 dosimetry. The range of activities in patients' SPECT images was determined for a meaningful comparison of measured and computed values. Knowledge of activity distributions in tumors and normal organs was essential for computing mean values and ranges of absorbed dose and provided a more complete description of the absorbed dose from 90Y-CC49 than was possible with planar methods.

Radiolabeled iododeoxyuridine: safety evaluation.

UNLABELLED: The emphasis of radiolabeled iododeoxyuridine (*IUdR) research at our institution to date has been to assess its safety as a potential therapeutic agent. Toward this goal, we have performed preclinical and clinical studies, using various routes of administration, to detect adverse changes in normal tissues in both humans and animals. As IUdR is rapidly dehalogenated by the liver, the intravenous route is unlikely to be successful in therapeutic efforts. We have therefore focused our attention on more "protected" routes: intra-arterial and intravesicular administration. METHODS: Studies were performed in farm pigs after multiple administrations of [125I]IUdR into the aorta, carotid artery and bladder. IUdR and metabolites were measured in venous blood samples at appropriate time intervals after administration, after which histologic examination of tissues was performed. Studies in human have been performed after intra-arterial administration of [123I]IUdR in patients with liver metastases and intravesicular administration in patients with bladder carcinoma, initially using [123I]IUdR and currently using both [123I]IUdR and [125I]IUdR. Blood samples for pharmacokinetics and metabolite analysis and tissue for autoradiography (when feasible) have been obtained. RESULTS: To date, no evidence of adverse effects on normal tissue or alteration of hematologic or metabolic indices have been seen in pigs or humans. When instilled in the bladder, there is little leakage of IUdR in the circulation. CONCLUSION: When [125I]IUdR is used as a therapeutic agent, we anticipate little or no effect on normal tissues.

Fast-atom bombardment tandem mass spectrometry of [(13)C]arachidonic acid labeled phospholipid molecular species.

A method employing stable isotope labeling and fast-atom bombardment (FAB) tandem mass spectrometry has been developed to directly assess events of biosynthesis and metabolism of arachidonic acid containing phospholipid molecular species by cells carried in culture. Mast cells, cultured with [(13)C]linoleic acid, converted this precursor into arachidonic acid which was then incorporated into cellular phospholipids. Over a 24 hour period, the extent of label enrichment in each arachidonate-containing phospholipid molecular species was monitored by using negative FAB ionization with selected reaction monitoring. Specific incorporation of [(13)C17] labeled arachidonate was determined from the ratio of the carboxylate anions at m/z 320 and 303, which correspond to [(13)C17]arachidonate and unlabeled arachidonate, respectively, produced by collision-induced dissociation of each specific molecular anion. The use of [(13)C]linoleic acid as a precursor of arachidonic acid avoids the problem of changing the endogenous pool size by directly adding labeled arachidonic acid. Measurement of the [(13)C17]label also avoids interferences from endogenous isobaric fatty acids that are naturally present at low levels.

Negative ion electrospray and tandem mass spectrometric analysis of platelet activating factor (PAF) (1-hexadecyl-2-acetyl-glycerophosphocholine).

The analysis of 1-hexadecyl-2-acetyl-glycerophosphocholine (platelet activating factor, PAF) by negative ion and normal-phase liquid chromatography/tandem mass spectrometry (LC/MS/MS) was investigated as an alternative technique to the currently used gas chromatography/MS and positive ion LC/MS/MS procedures. The positive ion [M + H]+ derived from PAF and generated by electrospray ionization is abundant, but the potential presence of isobaric 1-octadecanoyl-2-lyso-glycerophosphocholine (stearoyl-lyso-GPC) and 1-hexadecanoyl-2-formyl-glycerophosphocholine (PFPC) in biological samples limits the use of the most abundant collision-induced decomposition (CID) transition (formation of the phosphocholine ion, m/z 524-->184) if chromatographic separation is not achieved. Less abundant CID product ions, such as loss of the neutral ketene molecule derived from the respective fatty acyl groups, provide the requisite specificity, but the intensity of these transitions yields a signal-to-noise ratio that greatly diminishes the analytical sensitivity. With negative ion LC/MS/MS, however, the molecular anions [M - 15]- derived from PAF, stearoyl-lyso-GPC and PFPC decompose to the carboxylate anions at m/z 59, 283 and 255, respectively, permitting discrimination of these isobaric molecules even without chromatographic separation. In addition, the CID of [M - 15]- was favorable, yielding ion currents of sufficient intensity to permit the measurement of PAF when isolated from small quantities of biological material. With the use of a stable isotopically labeled variant of PAF and isotope dilution, negative ion LC/MS/MS was found to measure PAF reliably even in the presence of the isobaric stearoyl-lyso-GPC and permitted the use of non-chlorinated mobile phases for normal-phase high-performance LC.

Analysis of oxidized glycerophosphocholine lipids using electrospray ionization mass spectrometry and microderivatization techniques.

Oxidized low-density lipoprotein (LDL) is thought to play an important role in atherogenesis and cardiovascular disease in humans. Oxidized LDL is a complex mixture of many oxidized species, including numerous oxidized glycerophospholipids. Electrospray ionization and tandem mass spectrometry as well as microchemical derivatization of high-performance liquid chromatographically purified fractions derived from oxidized LDL were investigated as means to determine the structure of individual components present in oxidized LDL. One major oxidized phosphocholine lipid had an [M + H](+) ion at m/z 650. Derivatization to the trimethylsilyl ether and methoxime caused shifts in mass which, along with negative ion collision-induced dissociation mass spectra, were consistent with the presence of three species, 1-palmitoyl-2-(9-oxononanoyl)glycerophosphocholine and two isomeric 1-octadecanoyl-2-(hydroxyheptenoyl)glycerophosphocholines. These species were chemically synthesized. Trimethylsilylation of free hydroxyl groups increased the mass of the phospholipid acyl chains containing hydroxyl groups by 72 u. Conversion of carbonyl groups to the methoxylamine derivative increased the mass by 29 u. Ozonolysis of those products which contained double bonds proved to be a facile technique to determine the position and number of double bonds present. The use of these techniques was illustrated in the structural characterization of one major component (m/z 650, positive ions) in oxidized LDL as 1-octadecanoyl-2-(7-hydroxyhepta-5-enoyl)glycerophosphocholi ne. A possible mechanism for the formation of this unique chain-shortened glycerophospholipid is proposed.

Tropical obstetrics and gynaecology. 2. Maternal mortality.

Estimates of maternal deaths per 100,000 births are 270 for Latin America, 420 for Asia and 640 for Africa, compared to only 30 in developed countries. In places with high maternal death rates, women who fail to receive antenatal care and who then report to hospital only when their lives are threatened by major obstetric complications constitute the crux of the problem. In reducing maternal deaths in such places, especially in Africa, the need is to provide vigorous treatment for the unbooked emergencies and, at the same time, work towards the removal of the cultural, health and socio-economic conditions which create the unbooked emergencies. The first objective can be achieved through developing a network of first referral hospitals so that life saving measures are accessible to all who need them before it is too late. The second objective can be realized only through the universal provision and utilization of basic but professional antenatal care and also through modernization of the society as a whole. For all of these goals, universal formal education is fundamental.

Diagnostic use of radiolabeled antibodies for cancer.

Antibodies against a variety of tumor-associated antigens have been studied, as well as a number of modifications to the antibodies themselves, including Fab' fragments and chimeric, humanized, and human antibodies. The appropriate use of radioimmunoconjugates in the evaluation of cancer patients has not yet been clearly defined. Only a few studies have assessed their use, primarily through the intravenous route, in initial disease staging. To date, immunolymphoscintigraphy has not proven promising in the staging of cancers. More emphasis has been given to the use of IV radioimmunoconjugates to detect residual and recurrent disease, with generally favorable results. In addition, radioimmunoguided surgery, using small, handheld probes to detect foci of antibody accumulation, appears to be a valuable tool. As better production techniques become available and large clinical trials provide more clearly defined indications for radioimmunoconjugate use, these agents should enter the arena for routine diagnostic use.

Induction of high grade astrocytoma (HGA) by protons: molecular mechanisms and RBE considerations.

Protons of a specific energy, 55 MeV, have been found to induce primary high grade astrocytomas (HGA) in the Rhesus monkey (Macaca mulatta). Brain tumors of this type were not induced by protons of other energies (32-2,300 MeV). Induction of HGA has been identified in human patients who have had radiation therapy to the head. We believe that the induction of HGA in the monkey is a consequence of dose distribution, not some unique "toxic" property of protons. Comparison of the human experience with the monkey data indicates the RBE for induction of brain tumors to be about one. It is unlikely that protons cause an unusual change in oncogenic expression, as compared to conventional electromagnetic radiation.

Response patterns of children with learning disabilities: is impulsivity a stable response style?

A correlational analysis was conducted to assess the relationship among various assessment instruments, including Kagan, Rosman, Day, Albert, and Phillips's (1964) Matching Familiar Figures Test (MFFT), and actual classroom performance vis-à-vis impulsive responding. Subjects were 22 children (16 male, 6 female), ages 5 to 11 years, enrolled in an academic remediation program. The results do not support a relationship between impulsivity, as measured by the MFFT, and academic progress in a classroom setting. Implications for task-specific measures of impulsivity and remediation are discussed.

Leucocyte counts during pregnancy and the puerperium and at birth in Nigerians.

PIP: Serial observations have been made on the total and differential leucocyte counts of Nigerian primigravidae during pregnancy and the puerperium, and of their newborn infants. There was a neutrophil leucocytosis of double non-pregnant values during the 2nd and 3rd trimesters, and a peak during labor. The total white cell and neutrophil counts behaved in a manner similar to that reported in Caucasians, but counts were on average about 3.0 x 1 billionth 1 lower in the Nigerians. Eosinophil counts were high, presumably due to helminthic infections, but were lower in pregnancy than in non-pregnant state: there was a dramatic lowering of the eosinophil count at the time of delivery. Visual counting did not allow meaningful observations on changes in the basophil count. Monocyte counts were unaltered by pregnancy, but there was a significant drop in mean count caused by a great number of 0 differential counts at delivery. There was a slight but significant depression of lymphocyte count during pregnancy, but no further change at the time of delivery. All counts at 6 weeks after delivery were similar to those of adult male Nigerians. The leucocyte counts of African and Caucasian newborn appear to be similar. The data provide reference ranges of white cell counts in African or women of African descent during pregnancy.^ieng

Sickle cell disease in pregnancy.

S-Homozygotes, SC heterozygotes, and S-beta-thalassaemia heterozygotes are the haemoglobinopathies which make up sickle cell disease. Although their clinical features are similar, as regards complications during pregnancy, Hb S-beta-thalassaemia most dangerous, the main causes of mortality being severe anemia, acute sequestration crisis, bacterial infections, painful episodes, and pulmonary bone marrow fat embolism. Folic acid and antimalarials (where these are indicated) are often successful in preventing severe anaemia. It is best to reserve blood transfusion to replace moderate loss or to correct gross anaemia quickly when this is considered severe enough to threaten life. Painful crises are particularly common towards the end of pregnancy and in treating these episodes, analgesics, antibiotics, and sometimes heparin are used. S-homozygote carries additional hazards. Because of the prevalence of pelvic contraction, fetopelvic disproportion is common and so the incidence of operative deliveries is high. Many fetuses are lost through an increased incidence of abortion and perinatal mortality. In the survivors, there is evidence of intrauterine growth retardation brought about by continuous maternal anaemia throughout pregnancy.

Teratomas in adult Nigerians.

Over a six-year period, 132 teratomas were seen at the Ahmadu Bello University Hospital in Zaria, Nigeria. Twenty-seven of these, comprising most of the extragonadal tumours were seen in infants and children. Of the 105 tumours found in adults, ninety-four were benign cystic teratomas of the ovary occurring mostly in the third and fourth decades of life. There were three instances of malignant transformation of a previously benign cystic ovarian teratoma and four cases of struma ovarii, one of which was admixed with trabecular carcinoid but none of which was associated with hyperthyroidism or carcinoma. This study confirms the rarity in adult Nigerians of the following tumours each of which occurred only once in the series: mediastinal, solid ovarian teratoma, testicular and sacrococcygeal teratoma. The latter two were malignant and the sacrococcygeal tumour has been reclassified as an endodermal sinus tumour.