Effect of the Cox maze procedure on the secretion of atrial natriuretic peptide

OBJECTIVES

The Cox maze procedure has been confirmed to be effective in curing atrial fibrillation. Some authors have reported severe fluid retention after the Cox maze procedure and have suggested decreased secretion of atrial natriuretic peptide as a possible mechanism. This study was designed (1) to examine the serial changes in atrial natriuretic peptide after the Cox maze procedure as compared with changes occurring after coronary artery bypass grafting and (2) to elucidate any differences in atrial natriuretic peptide levels between patients with transient recurrence of atrial fibrillation after the Cox maze procedure and those without recurrence of atrial fibrillation.

METHODS

Blood samples were drawn from the right and left atria in patients undergoing the Cox maze procedure (n = 19) and from the right atrium in patients undergoing coronary artery bypass grafting (n = 6) before and 1, 2, and 3 days after the operation. In six patients undergoing the Cox maze procedure, samples were also drawn from the radial artery before and 1, 2, 3, 5, and 7 days after the operation. The plasma samples were prepared by refrigerated centrifugation and stored until radioimmunoassay. In the Cox maze procedure group, atrial natriuretic peptide levels in the right atrium were 629 +/- 366, 154 +/- 112, 162 +/- 112, and 183 +/- 97 pg/ml and those in the left atrium were 276 +/- 168, 152 +/- 91, 162 +/- 111, and 145 +/- 80 pg/ml before and 1, 2, and 3 days after the operation, respectively. A marked decrease in atrial natriuretic peptide levels was evident after the Cox maze procedure (p < 0.001). There was no significant correlation between atrial natriuretic peptide levels and atrial pressures after the Cox maze procedure, which suggests that secretion of atrial natriuretic peptide by the atria was impaired. There was a significant correlation between the atrial natriuretic peptide levels in the left atrium and those in the peripheral radial artery, and the decreased levels of atrial natriuretic peptide in the radial artery continued for 7 days after the Cox maze procedure. There were no differences in the atrial natriuretic peptide levels between the patients with transient recurrence of atrial fibrillation (n = 6) and those without recurrence (n = 13) after the Cox maze procedure. In the coronary artery bypass grafting group, the atrial natriuretic peptide levels in the right atrium were 115 +/- 37, 124 +/- 48, 154 +/- 54, and 156 +/- 36 pg/ml before and 1, 2, and 3 days after the operation, respectively. No change was seen after the operation.

CONCLUSIONS

We observed a significant decrease in atrial natriuretic peptide levels after the Cox maze procedure. This may be one of the possible causes of fluid retention after this procedure. These decreased atrial natriuretic peptide levels after the Cox maze procedure may result from the multiple atriotomy incisions and excision of both atrial auricles performed during the procedure, rather than from the conversion of atrial fibrillation to normal sinus rhythm.

Antibody to Pneumocystis carinii protects rats and mice from developing pneumonia

Well-proven mouse and rat models were used to show that polyclonal antisera to Pneumocystis carinii protect against P. carinii pneumonia. Antibodies were obtained from animals that were allowed to recover from severe P. carinii pneumonia after immunosuppression had been stopped and which then were given a booster injection of P. carinii from the same animal species. Mice immunosuppressed with corticosteroids or antibodies to L3T4+ lymphocytes (which are comparable to CD4 cells of humans) and transtracheally inoculated with mouse P. carinii did not develop P. carinii pneumonia if they were passively immunized with antiserum, while mice immunosuppressed and inoculated by identical procedures but not given antibodies developed severe infections. Rats immunosuppressed with corticosteroids and inoculated with rat P. carinii had less severe infections if they were given rat anti-P. carinii antisera. The polyclonal antisera developed in mice provided greater protection for the mice than the polyclonal rat antisera did for the rats; however, the potencies and compositions of the antisera were not quantitated and probably differed. Since both rats and mice can be protected from P. carinii infections with polyclonal antisera, it may be possible to develop vaccines that will elicit protective antibodies in humans.

Regulation of mu binding sites after chronic administration of antibodies directed against specific anti-opiate peptides

There is some indication that anti-opiate peptides (AOP) modulate opioid receptor systems by altering mu-receptor density. To further characterize this phenomenon, we investigated the effects of continuous infusion of anti-AOP IgG on mu binding sites in the brains of rats. Specifically, male Sprague-Dawley rats received intracerebroventricular (i.c.v.) infusions for 13 days of either control (rabbit) IgG or test IgGs: anti-dynorphin A IgG, anti-dynorphin A1-8 IgG, anti-alpha-MSH IgG, or the monoclonal anti-NPFF IgG. Administration of anti-NPFF IgG or the anti-dynorphin1-8 IgG significantly increased mu labeling by 40-70% in several brain regions at the caudate level. Contrary to these findings, anti-alpha-MSH IgG decreased (19-32%) [125I]-DAMGO labeling in several thalamic nuclei. The results suggest that the density of mu-opioid receptors is regulated in part by anti-opiate peptides in the extracellular fluid of the brain.

Dose-response relationship and irreversible obstructive ventilatory defect in patients with consumption of Sauropus androgynus

STUDY OBJECTIVES

To determine the dose-response aspect of pulmonary function impairment in patients with consumption of Sauropus androgynus for weight reduction.

METHODS

A questionnaire and pulmonary function tests were performed in 194 patients with a history of consumption of S androgynus with or without chest symptoms. Patients with obstructive ventilatory defect received follow-up spirometry 22 to 24 months after beginning consumption of the vegetable.

RESULTS

Data from 178 patients were analyzed. Patients generally consumed 150 g of S androgynus daily as raw juice (60.7%), sauteed (16.9%), mixed preparation (20.8%), or boiled (1.7%) for various periods of time. We divided patients into five groups according to the total dose consumed (group A, 0 to 1,799 g; group B, 1,800 to 3,599 g; group C, 3,600 to 5,399 g; group D, 5,400 to 7,199 g; and group E, > or =7,200 g). The frequency of obstructive ventilatory defect was higher in the high-dose group than in the low-dose group (A, 4/43=9.3%; B, 13/64=20.3%; C, 14/32=43.8%; D, 5/12=41.7%; and E, 13/27=48.1%; p < 0.01). In total, 49 patients (27.5%) had moderate to severe obstructive ventilatory defects without bronchodilator response. The FEV1 and FEV1 percent predicted in these 49 patients were 0.96+/-0.38 L (mean+/-SD) and 41.8+/-16.9%, respectively. Sixty-five percent of these 49 patients began to suffer from dyspnea in the third, fourth, or fifth month after taking the vegetable and no patient began to develop dyspnea later than 7 months after beginning consumption of the vegetable. Using stepwise multiple regression, we found that the FEV1 percent predicted was negatively associated with the total dose ingested (r=0.24, p < 0.01). Follow-up spirometry showed that the obstructive ventilatory defect was irreversible in all patients.

CONCLUSIONS

Consumption of S androgynus can result in moderate to severe obstructive ventilatory defect within 7 months, and the disorder was irreversible in the observation period for 22 months.

Effects of germanium oxide and other chemical compounds on phenylmercury acetate-induced genotoxicity in cultured human lymphocytes

Phenylmercury acetate (PMA), which not only causes an elevation of sister chromatid exchanges (SCEs) but also induces high frequency of endoreduplication in human lymphocytes, may be genotoxic to humans. The major aim of our study was to investigate the effects of germanium oxide (GeO2), D-penicillamine (D-PA), dimercaprol (BAL), and diltiazem (DTM) on PMA-induced genotoxicity as quantified by SCEs. All concentrations of the four chemical compounds tested alone did not induce genotoxicity in cultured human lymphocytes. However, GeO2 significantly inhibited PMA-induced genotoxicity in a concentration-dependent manner. Similarly, D-PA at concentrations of 3 microM and 10 microM, and BAL at a concentration of 30 microM produced the antigenotoxic effects. In addition, GeO2 (1.5 microM) significantly reversed an increase of endoreduplication frequency caused by PMA. In a cell cycle kinetic study, GeO2 (0.5-5.0 microM) reversed the inhibition of PMA on the proliferating rate index (PRI) of lymphocytes. On the contrary, both D-PA and DTM at concentrations of 30-300 microM markedly potentiated PMA-induced inhibition of PRI. These findings show that GeO2, D-PA and BAL could antagonize PMA-induced genotoxicity, and GeO2 appears to be the most effective.

Abnormal transcripts of FHIT gene in thyroid cancer

Abnormalities of the FHIT gene were found in many carcinoma cell lines and human tumors as reported which suggest an etiological function in tumorigenesis. To investigate whether the FHIT gene is a target of thyroid tumor specific 3p alterations, we screened the FHIT gene for alteration in thyroid tumors and found that the tumors exhibited aberrant FHIT gene expression. The complete sequence of the FHIT gene in seven cases was determined and deletions between exon 2-9 in different regions were found. Goiter samples as control had normal FHIT transcripts while both normal and aberrant transcripts of FHIT were found not only in the tumor samples but also in the adjacent non-tumorous portion of the thyroid tumor. Our results support the hypothesis that FHIT gene alteration is involved in tumorigenetic development of human neoplasms in thyroid glands.

Detection of Chlamydia trachomatis in urine samples by polymerase chain reaction and enzyme immunoassay

First-void urine samples collected from sexually transmitted diseases (STD) clinic patients were examined by a nested polymerase chain reaction (PCR) and a commercial enzyme immunoassay (IDEIA Chlamydia) for the diagnosis of Chlamydia trachomatis urethritis or cervicitis. The primers for the PCR amplified a target in the major outer membrane protein (MOMP) gene in C trachomatis while the IDEIA detected genus-specific chlamydial lipopolysaccharide. Discrepant results were resolved by retesting urine specimens with a second (plasmid-based) PCR and taking urethral or endocervical swab results into consideration. For 231 men (chlamydial prevalence 20.4%), the sensitivity, specificity, positive and negative predictive values were 59.6%, 99.5%, 96.6% and 90.6% for urine IDEIA, 68.1%, 99.5%, 97% and 92.4% for urethral swab IDEIA and 97.9%, 99.5%, 97.9% and 99.5% for urine PCR. The corresponding rates for 66 women (chlamydial prevalence 54.6%) were 19.4%, 100%, 100% and 50.8% for urine IDEIA, 86.1%, 96.7%, 96.9% and 85.3% for endocervical swab IDEIA and 91.7%, 93.3%, 94.3% and 90.3% for urine PCR. Hence, in a high prevalence population, the urine IDEIA was a suitable alternative to the male urethral swab IDEIA but significantly less sensitive than the endocervical swab IDEIA. The urine PCR was, however, much more sensitive than the urine IDEIA for both men and women and could replace the endocervical swab IDEIA for the diagnosis of chlamydial cervicitis.

Fibrosing inflammatory pseudotumors of the central skull base

The most important step in the differential diagnosis of mass lesions of the central skull base is to rule out malignant neoplasms. However, nonneoplastic lesions, such as infections or nonspecific inflammatory lesions of the skull base, can mimic malignant processes. In this study, the authors analyzed seven cases of nonneoplastic noninfectious mass-forming lesions involving the central skull base. In most cases, malignant processes were suspected at the initial phase of diagnostic work-up, but subsequent histologic examinations revealed that these lesions consisted of inflammatory cells and fibrosis without neoplastic cells. Common manifestations were pain and other neurological symptoms related to the involved anatomical sites. A variety of neurological dysfunctions of the cranial nerves not including the olfactory and spinal accessory nerves were observed. No patient developed separate lesions outside the head and neck region. After the pathologic diagnosis, most of the patients were treated with oral steroid therapy, with initial doses of prednisolone, 60 to 100 mg/d. It was difficult to relate responsiveness to steroid therapy with the histologic degree of sclerosis, fibrosis, or chronicity of the disease in these cases. Otolaryngologists should be aware of this disease when making treatment decisions for their patients with skull base lesions.

Mutagenicity and polycyclic aromatic hydrocarbon content of fumes from heated cooking oils produced in Taiwan

According to epidemiologic studies, exposure of women to fumes from cooking oils appears to be an important risk factor for lung cancer. Fume samples from three different commercial cooking oils frequently used in Taiwan were collected and analyzed for mutagenicity in the Salmonella/microsome assay. Polycyclic aromatic hydrocarbons were extracted from the samples and identified by HPLC chromatography. Extracts from three cooking oil fumes were found to be mutagenic in the presence of S9 mix. All samples contained dibenz[a,h]anthracene (DB[a,h]A) and benz[a]anthracene (B[a]A). Concentration of DB[a,h]A and B[a]A were 1.9 and 2.2 micrograms/m3 in fumes from lard oil, 2.1 and 2.3 micrograms/m3 in soybean oil, 1.8 and 1.3 micrograms/m3 in peanut oil, respectively. Benzo[a]pyrene (B[a]P) was identified in fume samples of soybean and peanut oil, in concentrations of 19.6 and 18.3 micrograms/m3, in this order. These results provide experimental evidence and support the findings of epidemiologic observations, in which women exposed to the emitted fumes of cooking oils are at increased risk of contracting lung cancer.

Wortmannin, a specific inhibitor of phosphatidylinositol-3-kinase, enhances LPS-induced NO production from murine peritoneal macrophages

To elucidate the role of phosphatidylinositol-3-kinase (PI3K) during macrophage activation, we examined the effects of wortmannin, a specific inhibitor of PI3K, on the induction of nitric oxide (NO) synthesis and tumor necrosis factor-alpha (TNF-alpha) secretion from lipopolysaccharide (LPS)-stimulated macrophages. Wortmannin had no effects on NO synthesis and TNF-alpha secretion by itself. Wortmannin markedly potentiated the LPS-induced NO production in a dose-dependent manner. Western blot analysis demonstrated that significantly increased levels of iNOS protein were expressed in LPS-stimulated macrophages treated with wortmannin, compared to those without LPS. Furthermore, enhancement of TNF-alpha secretion was observed in the initiation stage for activation of LPS-stimulated macrophages treated with wortmannin. These results suggest that PI3K plays an important role in transducing the signal that is involved in LPS-induced macrophage activation.

The orphan nuclear receptor TR2 suppresses a DR4 hormone response element of the mouse CRABP-I gene promoter

The mouse orphan nuclear receptor TR2-11-f suppressed the expression of reporters fused to a hormone response element of the mouse cellular retinoic acid-binding protein I gene promoter. TR2-11-f was able to bind to a direct repeat with four nucleotides in the spacer (5'TGACCTTTGGGGACCT3') located within this hormone response element as homodimers. The specificity of protein-DNA interactions was demonstrated by competition in gel retardation and antibody-mediated supershift reactions. The residues critical for TR2-11-f binding were mapped to both repeated sequences, whereas the spacer and the flanking sequences were less important. The Kd and Bmax of TR2-11-f homodimer binding to this direct repeat were determined to be 2.6 nM and 0.012 nM, respectively. By using a yeast two-hybrid system, it was demonstrated that dimerization of TR2-11-f was mediated by its ligand-binding domain. The actions of TR2-11-f in regulating cellular retinoic acid-binding protein I gene will likely influence retinoic action and availability within the cells.

Pituitary-adrenal response in preterm very low birth weight infants after treatment with antenatal corticosteroids

Antenatal corticosteroids have been widely used for the prevention of respiratory distress syndrome in preterm neonates, yet little is known about their effects on the hypothalamic-pituitary-adrenal axis in these infants. We prospectively evaluated pituitary-adrenal function in 61 preterm (< 32 gestational weeks), very low birth weight (< 1500 g) infants on days 7 and 14 of life using the human CRH stimulation test. The baseline and poststimulation plasma ACTH and serum cortisol concentrations did not differ significantly between infants whose mothers received no antenatal corticosteroids, and those whose mothers received 1-2 doses or > 2 doses (mean 7.2 doses) of prenatal dexamethasone (P = > 0.12). The number of doses of dexamethasone and the time intervals between the last dose of drug and delivery did not significantly affect the pituitary-adrenal responsiveness on days 7 and 14 of life. Among infants who did not require mechanical ventilation at the time of the human CRH test, significantly higher plasma ACTH (P < 0.014) and lower serum cortisol concentrations (P < 0.02) were found on day 14 than on day 7. In contrast, none of the poststimulation hormone concentrations were significantly different in ventilated infants between days 7 and 14. The relationship between the blood hormone concentrations in each time epoch (day 7 and day 14) and possible confounding factors including gestational and postconceptional age, birth weight, sex, Apgar scores, mode of delivery, single or higher order births, and mode of ventilation were determined. Plasma ACTH concentrations on day 7 were found to be significantly higher in ventilated than in nonventilated infants (P = 0.006). However, none of the aforementioned factors correlated significantly with plasma ACTH concentrations on day 14. Serum cortisol concentrations on day 7 were significantly higher in infants of greater gestational age (P = 0.039) and birth weight (P = 0.013), with lower Apgar scores at 1 and 5 min (P = 0.021 and P = 0.049, respectively), and in those delivered vaginally (P = 0.047). Similarly, serum cortisol concentrations on day 14 were found to be significantly higher in infants with lower Apgar scores at 1 and 5 min (P = 0.011 and P = 0.014, respectively) and in infants requiring mechanical ventilation (P = 0.014). Our results suggest that single or multiple courses of antenatal dexamethasone have no long-lasting suppressive effects on pituitary-adrenal function in preterm, very low birth weight infants. Maturation of pituitary function appears to be more advanced than adrenal function. The organ's ability to respond appropriately to various stressful stimuli indicates that the pituitary-adrenal axis is highly responsive at these early gestational ages.

Arterial oxygen desaturation during emergent nonsedated upper gastrointestinal endoscopy in the emergency department

A prospective study was conducted to see whether emergent esophagogastroduodenoscopy (EGD) in patients with active upper gastrointestinal (GI) bleeding is associated with more oxygen desaturation than nonemergent EGD. Emergent EGD was performed in the study patients with active upper GI bleeding. Nonemergent EGD was performed in the control patients. Determination of oxygen saturation (Sao2) was measured by pulse oximeter. A decrease in Sao2 of > 4% was more frequent in the study patients (26%, 13 of 50) than in controls (6%, 3 of 50) (P < .01). During EGD, mean oxygen saturation decreased significantly in both groups of patients. After EGD, mean oxygen saturation did not recover toward the pre-endoscopy insertion level in the study group (P < .01). A linear association was found that oxygen desaturation = 5.46 + 0.15 (status) -0.06 (baseline oxygen saturation). Emergent EGD for active upper GI bleeding in the emergency department tends to be associated with more frequent significant oxygen desaturation than nonemergent EGD. Continuous oxygen supplementation and oxygen saturation monitoring may be used during emergent nonsedated EGD in the emergency department.

Selective intra-arterial calcium injection in the investigation of adult nesidioblastosis: a case report

A 69-year-old man with recurrent hypoglycaemia had inappropriately elevated plasma insulin level during a symptomatic hypoglycaemia, but had a negative prolonged fast. Computerized tomography (CT) of the abdomen revealed a nodular lesion over the body of pancreas, whereas pancreatic arteriography failed to show tumour blush. Hence, arterial stimulation (with calcium) and venous sampling (ASVS) was performed and a brisk response of plasma insulin level was found when calcium was injected both into the splenic and the superior mesenteric arteries. Since no tumour was found during the operation, the patient received subtotal distal pancreatectomy. Pathological examination of the resected tissue disclosed a typical finding of nesidioblastosis. We suggest that selective intra-arterial calcium injection with hepatic venous sampling for insulin gradients is useful for the diagnosis of adult nesidioblastosis.

Canceled stereotactic core-needle biopsy of the breast: analysis of 89 cases

PURPOSE

To determine reasons for cancellation of stereotactic core-needle breast biopsy and outcome in canceled cases.

MATERIALS AND METHODS

Among 572 scheduled stereotactic core-needle biopsies, 89 cases (16%) in 88 patients were canceled. In canceled cases, mammogram origin, mammographic abnormality, reason for cancellation, and outcome were determined.

RESULTS

In canceled cases, 50 (57%) of 88 patients were referred from another facility. Mammographic abnormality in most cases (72 [81%] of 89 canceled biopsies) was a mass(es); calcifications occurred in 14 cases (16%). Reasons for cancellation included (a) lesion was not recognized (26 cases [29%]), (b) lesion was reassessed as benign (17 cases [19%]), (c) cysts were diagnosed with ultrasound (US) (12 cases [13%]) or aspiration (11 cases [12%]), (d) lesion location was suboptimal (12 cases [13%]), (e) patient was intolerant of procedure (seven cases [8%]), and (f) other (four cases [4%]). Numbers of canceled biopsies from another facility and those from the authors' institution differed in cases in which lesions were reassessed as benign (12 and five cases, respectively) or cysts were diagnosed with US (10 and two cases, respectively). Lesions that could not be targeted included many pseudolesions and three cancers.

CONCLUSION

Complete work-up, including US examination, of breast lesions is necessary before stereotactic core-needle biopsy is scheduled. Inability to recognize a suspected lesion on stereotactic images should not preclude biopsy with another method.

Vasomotion in rat diaphragm microcirculation at rest and during stepwise arterial pressure reduction

The effect of haemorrhagic hypotension on the incidence, frequency and relative amplitude of vasomotion in rat diaphragm microcirculation was assessed by laser Doppler flowmetry (LDF). Graded bleeding to four hypotension levels (80, 60, 40 and 30% of the control state) were performed in 24 Sprague-Dawley rats. The incidence of vasomotion was 83% in the control state, 96% at the 80% level, 100% at the 60% level, 96% at the 40% level, and 46% at the 30% level. The median fundamental frequency of vasomotion determined manually during the control state and at the hypotension levels (in descending order) was 4.11 (range, 3.29-5.58) cycles min-1 (cpm), 4.48 (3.21-5.92) cpm, 4.20 (3.5-5.56) cpm, 4.01 (3.33-5.36) cpm, 3.71 (3.25-4.49) cpm (P < 0.01 from the fundamental frequency at 80 and 60% hypotension levels). The median relative amplitudes determined manually during the control state and descending hypotension levels were 44.5% (range, 24.9-135.9%), 69.4% (26.6-147.2%), 84.0% (40.3-177.1%) (P < 0.01 from resting and last stage of bleeding), 90.40% (26.2-189.6%) (P < 0.01 from resting and last stage of bleeding), 69.2% (35.6-93.2%). We concluded first that during the resting condition, vasomotion was frequently present in diaphragm microcirculation, which is distinct from other vascular beds of skeletal muscles. Second, the relative amplitude of vasomotion during haemorrhagic hypotension plotted against decreasing blood pressure exhibited a reverse U-shaped curve with a maximum at 40-60% of the control blood pressure, while the frequency of vasomotion remained relatively constant until the last stage of haemorrhage and centred around 3-5 cpm.

Dynamic model of multipass ultrashort-pulse laser amplifiers and its application

We developed a dynamic model for evaluating the gain and amplified spontaneous emission of multipass ultrashort-pulse laser amplifiers. This model takes into account the time dependence of the population inversion that is due to the time-varying pump power and the evolution of the amplified spontaneous emission. For gain media of a short upper-state lifetime, a time-dependent analysis is essential for the model to extend beyond order-of-magnitude estimation. We verified the model with a femtosecond dye laser amplifier. The calculated output energy is accurate to within +/-5% of the experimental data. We utilized this model to optimize the conversion efficiency of the dye laser amplifier under low-energy pumping. An efficiency of 2.3% is achieved with an optimal pump energy of only 4 muJ.

Evaluation of a fibrous cellulose drying agent in supercritical fluid extraction and pressurized liquid extraction of diverse pesticides

A fibrous cellulose powder (CF-1) was investigated as a drying agent for supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE), also known as accelerated solvent extraction. Analysis of fifty-eight diverse pesticides was performed using gas chromatography-ion-trap mass spectrometric detection (GC-ITD). Extraction efficiencies were correlated versus pesticide polarity with samples of different water-CF-1 ratios. The effect of water was much more pronounced in SFE using CO2 than PLE using acetonitrile. Pesticide recoveries and limits of detection of fortified tomato samples mixed with CF-1 were determined. PLE gave recoveries > 80% for nearly all pesticides, and SFE gave similar recoveries except for the most polar and non-polar pesticides. SFE typically gave lower detection limits than PLE due to fewer matrix interferants.

Sequence-specific recognition of the internalization motif of the Alzheimer's amyloid precursor protein by the X11 PTB domain

The crystal structure of the phosphotyrosine-binding domain (PTB) of the X11 protein has been determined, in complex with unphosphorylated peptides corresponding to a region of beta-amyloid precursor protein (betaAPP) that is required for receptor internalization. The mode of binding to X11 of the unphosphorylated peptides, which contain an NPxY motif, resembles that of phosphorylated peptides bound to the Shc and IRS-1 PTB domains. Eight peptide residues make specific contacts with the X11 PTB domain, and they collectively achieve high affinity (KD = 0.32 microM) and specificity. These results suggest that, in contrast to the SH2 domains, the PTB domains are primarily peptide-binding domains that have, in some cases, acquired specificity for phosphorylated tyrosines.

Detection of Pneumocystis carinii DNA in air samples: likely environmental risk to susceptible persons

The means by which humans acquire Pneumocystis carinii is not well understood. Whether it can be acquired from specific environmental sources or transmitted from person to person has not been determined. This study was designed to detect nucleic acids of P. carinii in air samples from various locations, including P. carinii-infected patients' homes and hospital rooms, non-P. carinii-infected patients' hospital rooms, empty hospital rooms, offices at Indiana University, and other homes in different locations. DNA was extracted from cellulose-ester filters through which air samples had been filtered, and the P. carinii DNA was amplified by PCR with primers specific for the internal transcribed spacer regions of rRNA. P. carinii DNA was found in 17 of 30 air samples (57%) from the rooms of P. carinii-infected patients. It was also found in 6 of the 21 other hospital rooms sampled (29%) but was not found in any of the offices, storage areas, or control homes. Environmental sampling suggests that the airborne presence of P. carinii genetic material and infectious organisms is plausible. The organism was also detected in locations where P. carinii patients were not immediately proximate, such as the hospital rooms of non-P. carinii-infected patients.

Colonization rates and serotypes of group B streptococci isolated from pregnant women in a Korean tertiary hospital

In a study designed to provide data on the rates of maternal carriage of group B streptococci (GBS) in Korean women, vaginal, anorectal, and urethral swab specimens from 459 pregnant women and ear canal and umbilicus swabs from their 288 neonates were cultured with new Granada medium and selective Todd-Hewitt broth. Additionally, the serotypes of 64 isolates of GBS and the minimal inhibitory concentrations of seven antimicrobial agents for these isolates were determined. The rate of colonization by GBS in pregnant women and in their babies was 5.9% (27/459) and 0.7% (2/288), respectively. The rates of resistance of GBS isolated from pregnant women were 13.3% to clindamycin, 5% to erythromycin, and 98.3% to tetracycline. The majority of GBS isolates from pregnant women belonged to serotypes Ib (48.3%), Ia (24.1%), and III (20.7%).

Regulation of the mouse cellular retinoic acid-binding protein-I gene by thyroid hormone and retinoids in transgenic mouse embryos and P19 cells

The regulation of mouse cellular retinoic acid-binding protein-I (CRABP-I) gene expression by the retinoids and thyroid hormones was examined, by using a beta-galactosidase (lacZ) reporter gene and a CRABP-I specific antibody, in transgenic mouse embryos and a mouse embryonal carcinoma cell line P19. The CRABP-lacZ reporter gene expression recapitulated the expression pattern of endogenous CRABP-I in the developing central nervous system. In mid-gestation mouse embryos the expression of both the transgene and the endogenous protein was elevated under the condition of hypovitaminosis A, suggesting that depletion of retinoic acid (RA) induced CRABP-I expression in embryos. Consistently, this reporter was suppressed by RA in P19 cells. In co-transfection experiments it was demonstrated that the expression of RAR beta, RAR gamma or RXR alpha suppressed this reporter expression. In experiments designed to alter the thyroid hormone status in animals it was demonstrated that both the reporter gene and the endogenous CRABP-I expression were reduced by triiodothyronine injection and were elevated in a hypothyroidic condition induced by feeding with iodine-deficient diet supplemented with 6-propyl-2-thiouracil. In co-transfection experiments it was also demonstrated that the expression of T3R beta suppressed the reporter expression in P19 cells. It was concluded that RA had a suppressive effect on CRABP-I gene expression in embryos and P19 cells and the effect could be mediated through RAR beta, RAR gamma or RXR alpha. A role of thyroid hormones in CRABP-I gene expression and vitamin A metabolism in animals is discussed.