Synthesis and structure-activity relationships of new second-generation taxoids

A series of second-generation taxoids bearing a substituent on the C-2-benzoyl group and modifications at C-3'/C-10 positions was synthesized. These taxoids exhibited 2-3 orders of magnitude higher potency than that of paclitaxel against drug-resistant human breast cancer cell lines. It is also noteworthy that three taxoids showed almost no difference in activity against drug-resistant and drug-sensitive cell lines, which are categorized as "advanced second generation taxoids".

Decreased physical function in juvenile rheumatoid arthritis

OBJECTIVE

To assess the extent of physical disability in juvenile rheumatoid arthritis (JRA), classified according to subtype, and whether synovitis or flexion contractures are present on examination.

METHODS

This retrospective study included 88 JRA patients and 50 controls without musculoskeletal disease. The outcome measure was the disability index (DI) derived from the Childhood Health Assessment Questionnaire (CHAQ).

RESULTS

DI scores for JRA patients with synovitis (mean 0.49, range 0-1.88) and without synovitis (mean 0.37, range 0-1.75) were significantly higher (P < 0.001 for both groups) than for controls (mean 0.06, range 0-0.75, P < 0.001), but not significantly different from one another. Similarly, DI scores for JRA patients with and without any flexion contractures were higher than for controls, but not significantly different from one another. DI scores for JRA patients with both synovitis and flexion contractures were significantly higher than DI scores for JRA patients with neither, but were not distinguishable from JRA patients with synovitis only or flexion contractures only. Likewise, DI scores for JRA patients lacking synovitis and flexion contractures were not significantly different than those for JRA patients with one or the other. DI scores for systemic and polyarticular patients were higher than for pauciarticular patients, and DI scores for all 3 subtypes were higher than for controls.

CONCLUSION

Our findings suggest that many JRA patients, including those with pauciarticular JRA, have problems with physical function, even when synovitis and flexion contractures are not present. Further attention and research is needed to elucidate the causes or origins of disability in JRA patients with seemingly well-controlled disease. We recommend that health status instruments like the CHAQ be more widely used for JRA patients to complement other assessments, especially in planning occupational and physical therapy.

Mice lacking the basolateral Na-K-2Cl cotransporter have impaired epithelial chloride secretion and are profoundly deaf

In chloride-secretory epithelia, the basolateral Na-K-2Cl cotransporter (NKCC1) is thought to play a major role in transepithelial Cl(-) and fluid transport. Similarly, in marginal cells of the inner ear, NKCC1 has been proposed as a component of the entry pathway for K(+) that is secreted into the endolymph, thus playing a critical role in hearing. To test these hypotheses, we generated and analyzed an NKCC1-deficient mouse. Homozygous mutant (Nkcc1(-/-)) mice exhibited growth retardation, a 28% incidence of death around the time of weaning, and mild difficulties in maintaining their balance. Mean arterial blood pressure was significantly reduced in both heterozygous and homozygous mutants, indicating an important function for NKCC1 in the maintenance of blood pressure. cAMP-induced short circuit currents, which are dependent on the CFTR Cl(-) channel, were reduced in jejunum, cecum, and trachea of Nkcc1(-/-) mice, indicating that NKCC1 contributes to cAMP-induced Cl(-) secretion. In contrast, secretion of gastric acid in adult Nkcc1(-/-) stomachs and enterotoxin-stimulated fluid secretion in the intestine of suckling Nkcc1(-/-) mice were normal. Finally, homozygous mutants were deaf, and histological analysis of the inner ear revealed a collapse of the membranous labyrinth, consistent with a critical role for NKCC1 in transepithelial K(+) movements involved in generation of the K(+)-rich endolymph and the endocochlear potential.

Rapid, single-step procedure for the identification of transglutaminase-mediated isopeptide crosslinks in amino acid digests

Tissue transglutaminase (tTG) is a calcium-activated enzyme which can covalently crosslink the epsilon-amino group of a peptide-bound lysine into the gamma-carboxamide group of a peptide-bound glutamine, forming a epsilon-(-gamma-glutamyl)lysine isopeptide bond. We have developed a sensitive, single-step method for the isolation and detection of tTG-mediated isopeptide bonds from purified proteins and tissue homogenates. This method offers significantly improved resolution over current techniques, and obviates the need for multi-column systems or costly fluorescence monitors. By using enzymatic proteolysis, derivatization with phenylisothiocyanate, and a simple elution gradient for HPLC, we were able to determine the frequency of crosslinks in purified fibrin (1.7 mol of isodipeptide per mol of fibrin), crosslinked tau proteins (0.75 mol of isodipeptide per mol of tau), and whole-tissue liver homogenates (0.5 nmol of isodipeptide per mg of total protein).

HIV-associated risk factors among young Canadian Aboriginal and non-Aboriginal men who have sex with men

Young Aboriginal men face marginalization distinct in cause but similar in pattern to those seen among men who have sex with men (MSM) and may be at increased risk for HIV infection. We compared sociodemographic characteristics and risk taking behaviours associated with HIV infection among MSM of Aboriginal and non-Aboriginal descent. Data for this comparison were gathered from baseline questionnaires completed by participants in a cohort study of young MSM. Data collection included: demographic characteristics such as age, length of time residing in the Vancouver region, housing, employment, income and income sources; mental health and personal support; instances of forced sex and sex trade participation and; sexual practices with regular and casual male sex partners. Data were available for 57 Aboriginal and 624 non-Aboriginal MSM. Aboriginal MSM were significantly less likely to be employed, more likely to live in unstable housing, to have incomes of <$10,000 and to receive income assistance than non-Aboriginals (all P<0.01). Aboriginals also had higher depression scores (P<0.01), were more likely to report non-consensual sex (P=0.03), sexual abuse during childhood (P=0.04) and having been paid for sex (P<0.01). In the past year they were no more likely to have had sex with a male partner they knew to be HIV positive, to have had more than 50 male partners or to have unprotected anal insertive or receptive intercourse with their male partners (all P>0.05). Our data indicate that among MSM, Aboriginal men are at increased risk of antecedent risk factors for HIV infection including sexual abuse, poverty, poor mental health and involvement in the sex trade.

Normal surfactant pool sizes and inhibition-resistant surfactant from mice that overexpress surfactant protein A

Pulmonary surfactant protein-A (SP-A) has been reported to regulate the uptake and secretion of surfactant by alveolar type II cells, to stabilize large surfactant aggregates including tubular myelin, and to protect the surface activity of surfactant from protein inhibitors. In this study we investigated the consequences of overexpression of SP-A on pulmonary homeostasis and surfactant function in transgenic mice. The human SP-C promoter was used to direct synthesis of rat surfactant protein A (rSP-A) in alveolar type II cells and nonciliated bronchiolar cells of the distal respiratory epithelium. Levels of SP-A measured through enzyme-linked immunosorbent assay were 7- to 8-fold higher in lung homogenates and alveolar lavage fluid of the rSP-A mice than in those of transgene-negative littermates. The swimming exercise tolerance and lung compliance of mice bearing the transgene were unchanged. Mean air space sizes seen in randomly selected light-microscopic fields were not significantly different in the transgene-positive and -negative mice by morphometric analysis, but 15% of transgenic animals had scattered foci containing dilated alveoli and alveolar ducts without evidence of inflammation or fibrosis. Some alveolar macrophages contained bar-shaped osmophilic inclusions that had a highly ordered ultrastructure. There were no differences between the transgene-positive and -negative mice in the tissue or alveolar pool sizes of saturated phosphatidylcholine or in the large-aggregate composition of alveolar surfactant. The surface activity of surfactant isolated from the rSP-A mice was similar to that of the controls, but in the presence of protein inhibitors, the surface tension-reducing properties of the rSP-A surfactant were better preserved (P < 0.05). We conclude that overexpression of SP-A does not affect resting surfactant phospholipid levels, but that it enhances the resistance of surfactant to protein inhibition.

Poor reproducibility of in-source collisional atmospheric pressure ionization mass spectra of toxicologically relevant drugs

The purpose of the study was to examine the intra- and interlaboratory reproducibility of mass spectra obtained with liquid chromatography-atmospheric pressure ionization mass spectrometry (LC--API-MS) both in electrospray (ESI) and atmospheric pressure chemical ionization (APCI) modes. Toxicologically relevant drugs of different polarity were selected as test substances: morphine-6-glucuronide, 6-monoacetylmorphine, codeine, lysergic acid diethylamide, methylenedioxymethamphetamine. The study was performed in two laboratories using identical instruments and in one using a slightly different instrument. Basic instrument settings and mobile phase were identical in all laboratories. Mass spectra of drugs were taken at four collision energy voltages and using mobile phase of different composition (four concentration levels of acetonitrile and of ammonium formate buffer). The experiments demonstrated that mass spectra of given drugs, obtained in identical conditions with identical instruments, may show very different degrees of fragmentation. Mass spectra obtained with different instruments differed profoundly not only in the degree of fragmentation, but also different fragments and adducts were observed. Short-term intralaboratory reproducibility of mass spectra was satisfactory. On the other hand, the long-term experiments showed different degrees of fragmentation of APCI-generated mass spectra at nominally identical fragmentation energy. The changes in the composition of the mobile phase (concentration of organic modifier or buffer molarity) did not affect the reproducibility of fragmentation to any relevant degree. The study showed that the interlaboratory exchange and use of mass spectrum library, generated by single-quadrupole (LC--API-MS instruments, is hardly feasible at the moment, even under very carefully standardized conditions.

Calculation of the number of cancer deaths prevented by the Uranium Mill Tailings Remedial Action Project

The Uranium Mill Tailings Remedial Action Project has completed remedial action at 22 uranium mill tailings sites and about 5,000 properties ("vicinity properties") where tailings were used in construction, at a total cost of $1.45 billion. This paper uses existing data from Environmental Impact Statements and Environmental Assessments, and vicinity property calculations, to determine the total number of cancer deaths averted by the Uranium Mill Tailings Remedial Action Project. The cost-effectiveness of remediating each site, the vicinity properties, and the entire project is calculated. The cost per cancer death averted was four orders of magnitude higher at the least cost-effective site than at the most cost-effective site.

Vasorelaxant properties of parathyroid hormone-related protein in the mouse: evidence for endothelium involvement independent of nitric oxide formation

PTH-related peptide is produced in vascular smooth muscle and is believed to participate in the local control of vascular tone. The recent identification of mid-region PTHrP peptides, as well as the discovery of multiple receptors in blood vessels, raises new questions concerning the mechanisms by which PTHrP relaxes the vasculature. In this study, we examined these mechanisms in two vascular beds of the mouse. PTHrP-(1-34) and PTH-(1-34), but not PTHrP-(38-64) or PTHrP-(38-94), caused concentration-dependent relaxation of pre-contracted aortas and reduced the spontaneous phasic activity of the portal vein. PTHrP and PTH-induced aortic relaxations were largely endothelium dependent, whereas an intact endothelium was not necessary for maximal portal vein relaxation. The endothelium-dependent component of PTHrP and PTH-induced aortic relaxations were unaffected by pretreatment with either L-NNA or indomethacin but were abolished by pretreatment with tetrabutyl ammonium. These results demonstrate that the N-terminal portions of PTHrP and PTH are required for their vasorelaxant activity in the mouse. In addition, maximal relaxant activity of PTHrP and PTH in murine aorta is dependent on the endothelium, which appears to involve the generation of an endothelium-derived hyperpolarizing factor.

Targeted disruption of the murine Nhe1 locus induces ataxia, growth retardation, and seizures

In most cells, the ubiquitously expressed Na+/H+ exchanger isoform 1 (NHE1) is thought to be a primary regulator of pH homeostasis, cell volume regulation, and the proliferative response to growth factor stimulation. To study the function of NHE1 during embryogenesis when these cellular processes are very active, we targeted the Nhe1 gene by replacing the sequence encoding transmembrane domains 6 and 7 with the neomycin resistance gene. NHE activity assays on isolated acinar cells indicated that the targeted allele is functionally null. Although the absence of NHE1 is compatible with embryogenesis, Nhe1 homozygous mutants (-/-) exhibit a decreased rate of postnatal growth that is first evident at 2 wk of age. At this time, Nhe1 -/- animals also begin to exhibit ataxia and epileptic-like seizures. Approximately 67% of the -/- mutants die before weaning. Postmortem examinations frequently revealed an accumulation of a waxy particulate material inside the ears, around the eyes and chin, and on the ventral surface of the paws. Histological analysis of adult tissues revealed a thickening of the lamina propria and a slightly atrophic glandular mucosa in the stomach.

CD5- B-cell lymphoproliferative disorders presenting in blood and bone marrow. A clinicopathologic study of 40 patients

We studied 40 patients with CD5- B-cell lymphoproliferative disorders (B-LPDs) presenting in blood or bone marrow and 28 control patients with CD5+ B-cell chronic lymphocytic leukemia (CLL). Fifteen study patients had morphologic features typical of CLL. The 15 patients with CD5- CLL were older and had lower absolute lymphocyte counts and more advanced-stage disease at diagnosis than controls. Ten study patients had morphologic features suggesting mantle cell lymphoma (MCL); 3 were later given a diagnosis of MCL based on lymph node biopsy results. The 10 patients with CD5- MCL were older and at a more advanced stage than CLL control patients. The remaining 15 study patients were given the following diagnoses: circulating non-Hodgkin lymphoma, 5; splenic lymphoma with villous lymphocytes, 5; lymphoplasmacytoid lymphoma, 3; and CLL/pro-lymphocytic leukemia, 2. For the patients with CD5- B-LPDs with morphologic features and manifestations resembling CLL, we prefer the term CD5- CLL variant because of clinical and immunophenotypic differences. Patients with CD5- B-LPDs with atypical nuclear morphologic features may represent the leukemic phase of MCL. Since CD23 is expressed in most patients with CD5- B-LPD, its use in subclassifying these disorders seems limited.

Eosinophilic globules in spindle cell and epithelioid cell nevi: composition and possible origin

The presence of eosinophilic globules has been described as a helpful sign for the histologic differentiation of Spitz's nevus from malignant melanoma. The origin of these bodies is not clear, and they have been likened to Civatte or colloid bodies of lichen planus. This would suggest that they might originate from degenerating keratinocytes or melanocytes or both. These eosinophilic globules and the colloid bodies of lichen planus have been reported to be similar in that they both stain positively for type IV collagen and laminin. These previous reports have failed to include, or have not emphasized, the staining for keratin that separates these two bodies. We stained 10 spindle cell and epithelial cell (S&E) nevi for S-100 protein, keratin, vimentin, type IV collagen, and laminin. In all 10 cases of S&E nevi, the eosinophilic globules showed a positive reaction for type IV collagen and laminin and a negative reaction for keratin, S100 protein, and vimentin, unlike the colloid bodies of lichen planus, which showed a negative reaction for type IV collagen and laminin and also a strong positive reaction for keratin. These results suggest that the eosinophilic globules of Spitz's nevi are basement membrane material, perhaps synthesized by either basal cells, melanocytes or both, and are not degenerated basal cells or melanocytes.

Fast analysis of drugs in a single hair

A new method for the fast screening of cocaine and 6-monoacetylmorphine (6-MAM) in a single hair, using gas chromatography/mass spectrometry (GC/MS), is described. The analyses are conducted in less than 10 min with minimal sample preparation. The novel method combines the ChromatoProbe direct sample introduction device for intrainjector thermal extraction, fast GC separation, a supersonic molecular beam GC/MS interface and hyperthermal surface ionization (HSI). The technique has been successfully employed for the detection of cocaine in as little as a 1-mm section of hair using selected ion monitoring (SIM). Unambiguous full scan mass spectra of cocaine and 6-MAM were obtained on a single hair for cocaine and heroin users, respectively. HSI was found to be almost 3 orders of magnitude more selective than electron impact ionization for cocaine compared with the major hair constituents, with a minimum detected concentration of approximately 10 ppb in the SIM mode. Results obtained for 12 drugs users showed full qualitative agreement with similar results using rigorous solvent extraction followed by electrospray-liquid chromatography/mass spectrometry analysis. However, quantitative studies showed only partial agreement. No false positives were observed for 10 drugs free subjects. This method enables fast drug monitoring along the hair length which permits time correlation studies.

Phenotype resembling Gitelman's syndrome in mice lacking the apical Na+-Cl- cotransporter of the distal convoluted tubule

Mutations in the gene encoding the thiazide-sensitive Na+-Cl- cotransporter (NCC) of the distal convoluted tubule cause Gitelman's syndrome, an inherited hypokalemic alkalosis with hypomagnesemia and hypocalciuria. These metabolic abnormalities are secondary to the deficit in NaCl reabsorption, but the underlying mechanisms are unclear. To gain a better understanding of the role of NCC in sodium and fluid volume homeostasis and in the pathogenesis of Gitelman's syndrome, we used gene targeting to prepare an NCC-deficient mouse. Null mutant (Ncc-/-) mice appear healthy and are normal with respect to acid-base balance, plasma electrolyte concentrations, serum aldosterone levels, and blood pressure. Ncc-/- mice retain Na+ as well as wild-type mice when fed a Na+-depleted diet; however, after 2 weeks of Na+ depletion the mean arterial blood pressure of Ncc-/- mice was significantly lower than that of wild-type mice. In addition, Ncc-/- mice exhibited increased renin mRNA levels in kidney, hypomagnesemia and hypocalciuria, and morphological changes in the distal convoluted tubule. These data indicate that the loss of NCC activity in the mouse causes only subtle perturbations of sodium and fluid volume homeostasis, but renal handling of Mg2+ and Ca2+ are altered, as observed in Gitelman's syndrome.

Perceived need for local anesthesia in tooth drilling among Anglo-Americans, Chinese, and Scandinavians

This study explored ethnic differences in perceptions of pain and the need for local anesthesia for tooth drilling among age- and gender-matched Anglo-American, Mandarin Chinese, and Scandinavian dentists (n = 129) and adult patients (n = 396) using a systematic qualitative research strategy. Semistructured qualitative interviews determined: (a) the relative frequency of use or nonuse of anesthetic for similarly specified tooth drilling, (b) the reasons for nonuse of anesthetic as reported by dentists about their patients, and (c) the distribution of reasons for not using anesthetic. American dentists (n = 51) reported that about 1% of their adult patients did not use anesthetic compared with 90% among Chinese (n = 31) and 37.5% among Scandinavian dentists (n = 40). Of patients, Americans (n = 112) reported 6% nonuse of anesthetic for tooth drilling compared with 90% of 159 Chinese and 54% of 125 Scandinavians. Reasons among Anglo-Americans and Scandinavians were similar (ranked): the sensation was tolerable, to avoid numb feelings afterwards, and fear of injections. Danish patients were an exception; the fact that they had paid extra and out-of-pocket for anesthetic ranked second. In contrast, Chinese dentists made their decisions not to use anesthetics because they explained drilling as only a suan or "sourish" sensation, whereas injections were described as "painful." It was concluded that ethnic pain beliefs and differences in health-care systems are powerful psychosocial variables that affect pain perception and the perceived need for anesthetic.

The diagnostic usefulness of bone marrow cultures in patients with fever of unknown origin

Bone marrow cultures (BMCs) and blood cultures (BCs) are frequently obtained in the evaluation of fever of unknown origin (FUO). However, the low yield of clinically significant isolates leads to questions about their cost-effectiveness. We retrospectively compared BMC with BC and studied the usefulness of bone marrow trephine biopsy (BMTB) histopathology in detecting infection in an unselected population of 61 patients with FUO, among whom 215 BMCs had been performed. For patients who had undergone BMTB, the histopathology was evaluated for granulomas and microorganisms. Only 1 BMC had a clinically significant isolate, Mycobacterium avium complex (MAC), which was also identified by BC. Rhodotorula rubra was found in the BMC of another patient and classified as a contaminant. Both patients had HIV infection. No growth occurred in BCs for the other 59 patients. Culture results for all 26 BMTB specimens were negative; 4 contained nonnecrotizing granulomas, including the case with MAC. BMCs are probably not justified for routine initial evaluation of FUO, but may be valuable after culture results for blood and easily obtainable tissues have been negative. Bone marrow histopathology and special stains for microorganisms in the absence of granulomas were noncontributory.

Balance and hearing deficits in mice with a null mutation in the gene encoding plasma membrane Ca2+-ATPase isoform 2

Plasma membrane Ca2+-ATPase isoform 2 (PMCA2) exhibits a highly restricted tissue distribution, suggesting that it serves more specialized physiological functions than some of the other isoforms. A unique role in hearing is indicated by the high levels of PMCA2 expression in cochlear outer hair cells and spiral ganglion cells. To analyze the physiological role of PMCA2 we used gene targeting to produce PMCA2-deficient mice. Breeding of heterozygous mice yielded live homozygous mutant offspring. PMCA2-null mice grow more slowly than heterozygous and wild-type mice and exhibit an unsteady gait and difficulties in maintaining balance. Histological analysis of the cerebellum and inner ear of mutant and wild-type mice revealed that null mutants had slightly increased numbers of Purkinje neurons (in which PMCA2 is highly expressed), a decreased thickness of the molecular layer, an absence of otoconia in the vestibular system, and a range of abnormalities of the organ of Corti. Analysis of auditory evoked brainstem responses revealed that homozygous mutants were deaf and that heterozygous mice had a significant hearing loss. These data demonstrate that PMCA2 is required for both balance and hearing and suggest that it may be a major source of the calcium used in the formation and maintenance of otoconia.

Renal and intestinal absorptive defects in mice lacking the NHE3 Na+/H+ exchanger

NHE3 is one of five plasma membrane Na+/H+ exchangers and is encoded by the mouse gene Slc9a3. It is expressed on apical membranes of renal proximal tubule and intestinal epithelial cells and is thought to play a major role in NaCl and HCO3- absorption. As the distribution of NHE3 overlaps with that of the NHE2 isoform in kidney and intestine, the function and relative importance of NHE3 in vivo is unclear. To analyse its physiological functions, we generated mice lacking NHE3 function. Homozygous mutant (Slc9a3-/-) mice survive, but they have slight diarrhoea and blood analysis revealed that they are mildly acidotic. HCO3- and fluid absorption are sharply reduced in proximal convoluted tubules, blood pressure is reduced and there is a severe absorptive defect in the intestine. Thus, compensatory mechanisms must limit gross perturbations of electrolyte and acid-base balance. Plasma aldosterone is increased in NHE3-deficient mice, and expression of both renin and the AE1 (Slc4a1) Cl-/HCO3- exchanger mRNAs are induced in kidney. In the colon, epithelial Na+ channel activity is increased and colonic H+,K+-ATPase mRNA is massively induced. These data show that NHE3 is the major absorptive Na+/H+ exchanger in kidney and intestine, and that lack of the exchanger impairs acid-base balance and Na+-fluid volume homeostasis.

Consensus analysis: reliability, validity, and informant accuracy in use of American and Mandarin Chinese pain descriptors

A quantitative method for validating qualitative interview results and checking sample parameters is described and illustrated using common pain descriptions among a sample of Anglo-American and mandarin Chinese patients and dentists matched by age and gender. Assumptions were that subjects were members of a sociocultural group (e.g. ethnic or professional/lay) and answered questions independently about a monotonic domain (e.g. pain). Subjects answered 18 true/false items derived from and selected to reflect pain perceptions consistent with published and unpublished interview data. Estimates of consistency in use of descriptors within groups, validity of description, accuracy of individuals compared with others in their group, and minimum required sample size were calculated using Cronbach's alpha, factor analysis, and Bayesian probability. Ethnic and professional differences within and across groups were also tested using multidimensional scaling (MDS) and hypothesis testing. Consensus (consistency of subject response by group) was .99 among Anglo-Americans and .97 among Chinese. Mean subject accuracy was .81 for Americans and .57 for Chinese, indicating the need for larger numbers of Chinese to supplement each others' statements. However, larger numbers of subjects were recruited than actually required for each ethnic group at .95 confidence limits. MDS showed similarities in use of descriptors within ethnic groups, while there were differences (p < .001) between Chinese and American groups. Use of covalidating questionnaires that reflect results of qualitative interviews are recommended in order to estimate sample parameters such as intersubject agreement, individual subject accuracy, and minimum required sample sizes.

Targeted disruption of the murine Na+/H+ exchanger isoform 2 gene causes reduced viability of gastric parietal cells and loss of net acid secretion

Multiple isoforms of the Na+/H+ exchanger (NHE) are expressed at high levels in gastric epithelium, but the physiological role of individual isoforms is unclear. To study the function of NHE2, which is expressed in mucous, zymogenic, and parietal cells, we prepared mice with a null mutation in the NHE2 gene. Homozygous null mutants exhibit no overt disease phenotype, but the cellular composition of the oxyntic mucosa of the gastric corpus is altered, with parietal and zymogenic cells reduced markedly in number. Net acid secretion in null mutants is reduced slightly relative to wild-type levels just before weaning and is abolished in adult animals. Although mature parietal cells are observed, and appear morphologically to be engaged in active acid secretion, many of the parietal cells are in various stages of degeneration. These results indicate that NHE2 is not required for acid secretion by the parietal cell, but is essential for its long-term viability. This suggests that the unique sensitivity of NHE2 to inhibition by extracellular H+, which would allow upregulation of its activity by the increased interstitial alkalinity that accompanies acid secretion, might enable this isoform to play a specialized role in maintaining the long-term viability of the parietal cell.

Acute pain and use of local anesthesia: tooth drilling and childbirth labor pain beliefs among Anglo-Americans, Chinese, and Scandinavians

Differences in ethnic beliefs about the perceived need for local anesthesia for tooth drilling and childbirth labor were surveyed among Anglo-Americans, Mandarin Chinese, and Scandinavians (89 dentists and 251 patients) matched for age, gender, and occupation. Subjects matched survey questionnaire items selected from previously reported interview results to estimate (a) their beliefs about the possible use of anesthetic for tooth drilling and labor pain compared with other possible remedies and (b) the choice of pain descriptors associated with the use of nonuse of anesthetic, including descriptions of injection pain. Multidimensional scaling, Gamma, and Chi-square statistics as well as odds ratios and Spearman's correlations were employed in the analysis. Seventy-seven percent of American informants reported the use of anesthetics as possible remedies for drilling and 51% reported the use of anesthetics for labor pain compared with 34% that reported the use of anesthetics among Chinese for drilling and 5% for labor pain and 70% among Scandinavians for drilling and 35% for labor pain. Most Americans and Swedes described tooth-drilling sensations as sharp, most Chinese used descriptors such as sharp and "sourish" (suan), and most Danes used words like shooting (jagende). By rank, Americans described labor pain as cramping, sharp, and excruciating, Chinese used words like sharp, intermittent, and horrible, Danes used words like shooting, tiring, and sharp, and Swedes used words like tiring, "good," yet horrible. Preferred pain descriptors for drilling, birth, and injection pains varied significantly by ethnicity. Results corroborated conclusions of a qualitative study about pain beliefs in relation to perceived needs for anesthetic in tooth drilling. Samples used to obtain the results were estimated to approach qualitative representativity for these urban ethnic groups.

Atypical Pneumocystis carinii pneumonia in a child with hyper-IgM syndrome

Children with hyper-immunoglobulin M (hyper-IgM) syndrome are at increased risk for Pneumocystis carinii pneumonia (PCP), an opportunistic infection often found in immunodeficient hosts. PCP can present with increasing hypoxia, fever, cough, and respiratory distress. We describe a child with hyper-IgM syndrome in whom bronchoalveolar washings were negative for PCP. However, there was an atypical lung response in which caseating granulomas predominated. The histopathology, resembling that found in tuberculosis, stresses the importance of a high index of clinical suspicion and histologic confirmation for early intervention and treatment. Immunocompromised children with rapidly progressive pulmonary disease may require lung biopsy and stains such as GMS to identify PCP.

Comparative analysis of interphase FISH and RT-PCR to detect bcr-abl translocation in chronic myelogenous leukemia and related disorders

The t(9;22)(q34;q1 1) between the abl and bcr genes plays a pivotal role in the diagnosis and pathogenesis of chronic myelogenous leukemia (CML). Its detection is routinely accomplished by Southern blot analysis and karyotyping. Interphase fluorescence in situ hybridization (FISH) and reverse transcriptase-polymerase chain reaction (RT-PCR) are emerging molecular techniques that offer viable alternatives. We analyzed 40 samples of peripheral blood and bone marrow (CML, 16; acute myelogenous leukemia, 6; acute lymphoblastic leukemia [ALL], 1; chronic lymphoblastic leukemia, 2; myelodysplasias, 4; myeloproliferative disorders, unclassified, 3; nonleukemic hematologic malignancies, 3; hypercellular bone marrow, 1; normal control samples, 2; and K562 cell line samples, 2) for the presence of bcr-abl fusion gene and its messenger RNA (mRNA) transcript by FISH and RT-PCR, respectively. We compared the results with results of Southern blot analysis and karyotyping when available. Cost analysis was performed. Thirty-three samples were evaluable by FISH; 14 of 14 evaluable CML samples and one ALL sample were positive for bcr-abl by FISH (100%). The other 15 evaluable samples were negative; 16 of 16 (100%) and 13 of 16 (81%) of CML cases were positive for bcr-abl mRNA by RT-PCR (chemiluminescent blot method) and RT-PCR (colorimetric method), respectively. The ALL sample was positive by both RT-PCR methods. All other samples were negative by RT-PCR (chemiluminescent blot method), and all but 1 case of myeloproliferative disorder tested negative by RT-PCR (colorimetric method). We conclude the utility of FISH and RT-PCR is associated with certain limitations, such as insufficient RNA for RT-PCR and the occasional absence of internal positive FISH control signals. However, each procedure offers (with a high concordance rate) a specific and cost-effective alternative to Southern blot analysis and karyotyping and improved turnaround time for the detection of bcr-abl fusion gene or its mRNA transcript.

Defective endothelium-dependent relaxation of vascular smooth muscle and endothelial cell Ca2+ signaling in mice lacking sarco(endo)plasmic reticulum Ca2+-ATPase isoform 3

Sarco(endo)plasmic reticulum Ca2+ ATPase isoform 3 (SERCA3) is one of two Ca2+ pumps serving intracellular Ca2+ signaling pools in non-muscle tissues; however, unlike the ubiquitous SERCA2b, it exhibits a restricted cell-type distribution. Gene targeting was used to generate a mouse with a null mutation in the SERCA3 gene. Homozygous mutant mice were viable, fertile, and did not exhibit an overt disease phenotype. Because SERCA3 is expressed in arterial endothelial cells, aortic ring preparations were analyzed to determine whether it is involved in the regulation of vascular tone. Contraction-isometric force relations in response to phenylephrine or KCl, as well as relaxation produced by exposure to a nitric oxide donor, were similar in wild-type and null mutant aortas. Acetylcholine-induced endothelium-dependent relaxation of aortas after precontraction with phenylephrine was significantly reduced in homozygous mutants (61.3 +/- 5.6% in wild type, 35.4 +/- 7.3% in mutants). Ca2+ imaging of cultured aortic endothelial cells demonstrated that the acetylcholine-induced intracellular Ca2+ signal is sharply diminished in SERCA3-deficient cells and also indicated that replenishment of the acetylcholine-responsive Ca2+ stores is severely impaired. These results indicate that SERCA3 plays a critical role in endothelial cell Ca2+ signaling events involved in nitric oxide-mediated relaxation of vascular smooth muscle.

The analysis of EDTA in dried bloodstains by electrospray LC-MS-MS and ion chromatography

Analytical methods were developed to determine the presence of ethylenediaminetetraacetic acid (EDTA) in dried bloodstains to provide probative information when allegations of evidence tampering have been made in criminal cases. A simple screening method using ion chromatography to analyze stains was found to be quantitative to the 5 ppm level. The presence of EDTA was then confirmed using negative and positive ion mode liquid chromatography-tandem mass spectrometry (LC-MS-MS) methods. A blind trial of these methods on 42 samples correctly determined the bloodstains that did and did not contain the preservative EDTA. One interesting observation in these results was the adsorption and postanalysis release of EDTA in the chromatographic system. In order to avoid cross contamination of samples resulting from this phenomena, it was found to be necessary to use EDTA-free blood extracts as blanks in the LC-MS analysis of bloodstains.