Pleural carcinosis confirmed by adjuvant cytological methods: a case report

We describe a case of a 43-yr-old woman presenting a progressive pleural effusion. The patient was known to have an acute myeloid leukemia in complete remission after allogenic bone marrow transplantation. Suspicion of pleural carcinosis was raised cytologically and confirmed by immunocytochemistry, DNA-cytometry, and atomic force microscopy. We emphasize the use of these additional methods for the distinction of adenocarcinoma cells in effusions from reactive mesothelial cells.

Auditory afterimage: tonotopic representation in the auditory cortex

The auditory afterimage is a sensation which occurs for several seconds after the exciting acoustic signal has been switched off, and which roughly corresponds to the inverse of the spectrum of the exciting signal. In contrast to the well-known visual afterimage, the physiological mechanism generating the auditory afterimage has been questionable so far. Neuromagnetic source imaging revealed that the source of cortical neural activity which coincides with the sensation of the afterimage is located in the auditory cortex and exhibits a tonotopic organization similar to that of the sustained response which occurs during continuous presentation of an acoustic stimulus. It is concluded that the neural processes leading to the generation of the two phenomena -sustained response and auditory afterimage - are similar.

Tinnitus and event-related activity of the auditory cortex

A neuromagnetic study in tinnitus patients and normal-hearing controls was performed with a modified contingent negative variation (CNV) paradigm. While the warning stimulus S1 was a tone burst at an intensity well above threshold, the imperative stimulus S2 was presented at a near threshold intensity because, in the majority of cases, the perceived loudness of tinnitus is very close to the threshold for a pure tone of the same frequency. Subjects had to respond to S2 by pressing a button until its offset was detected. In this case, instead of the usual sudden cut-off of the CNV after the perception of S2, a slow negative deflection develops, the post-imperative negative variation (PINV). Its initial portion probably indicates the development of a second initial CNV because the subject had to attend also to the offset of S2. The neuromagnetic data were analysed both in the time domain and in the frequency domain (short-time spectral analysis of the classical EEG bands). The time domain waveform as well as the spectrotemporal patterns of the MEG bands exhibited deviations from the normal pattern in several tinnitus subgroups, depending on the characteristics of tinnitus (tonal vs. noisiform, monaural vs. binaural) and on the stimulation conditions (tinnitus side vs. non-tinnitus side).

Lack of effect of oral choline supplement on the concentrations of choline metabolites in human brain

Recent reports suggest that oral choline supplement may alter the cerebral choline/creatine (Cho/Cr) ratio and might be used to treat neurodegenerative disorders of cholinergic transmission. Using both 1H and 31P MRS, we reexamined the Cho/Cr ratio and quantified cerebral choline and its major constituents: phosphoethanolamine (PE), phosphorylcholine (PC), glycerophosphorylethanolamine (GPE), and glycerophosphorylcholine (GPC). In the four brain locations examined, no significant increases in Cho/Cr, [Cho], or in its major constituents were found in response to an oral challenge of 50 mg/kg of choline bitartrate. Oral choline did not significantly affect human cerebral metabolism in the short term.

Comparison of high-energy pulsed carbon dioxide laser resurfacing and dermabrasion in the revision of surgical scars

BACKGROUND

Both dermabrasion and high-energy pulsed carbon dioxide (CO2) laser resurfacing can improve the appearance of surgical scars. Although the results of these two procedures have been compared using historical data, a prospective evaluation has never been performed in humans.

OBJECTIVE

To prospectively compare the clinical effects of dermabrasion and high-energy pulsed CO2 laser resurfacing in the revision of surgical scars.

METHODS

Facial surgical scars in four patients were prospectively revised using a split scar model. One half of the scar was dermabraded and the other half was resurfaced with the high-energy pulsed CO2 laser. Comparisons of the two treatment modalities were performed through clinical assessment, photographic evaluation, and textural analysis of the scars.

RESULTS

The high-energy pulsed CO2 laser-resurfaced halves of the scar were bloodless with less postoperative crusting in comparison with the dermabraded halves. Reepithelialization time and degree and duration of postoperative erythema were similar for both treatment halves. Photographic evaluation and textural analysis showed comparable improvement in the clinical appearance and surface texture of the scars with both treatment modalities.

CONCLUSIONS

Both the high-energy pulsed CO2 laser and dermabrasion can achieve comparable clinical improvement in the revision of surgical scars. The high-energy pulsed CO2 laser offers the advantage of a bloodless field and a more precise method of tissue ablation. Postoperative erythema, however, is an expected finding with both treatment modalities.

Static DNA cytometry as a diagnostic aid in effusion cytology: I. DNA aneuploidy for identification and differentiation of primary and secondary tumors of the serous membranes

OBJECTIVE

To determine whether DNA aneuploidy is a sensitive and specific marker for the identification of tumor cells in effusions and whether the pattern of DNA aneuploidy can provide important information for the differential diagnosis of primary and secondary tumors of the serous membranes.

STUDY DESIGN

One hundred eight malignant mesotheliomas as well as 102 metastatic carcinomas of the serous membranes were obtained from routine cytologic and histologic material. One hundred reactive effusions were investigated as controls. Nuclear DNA contents were measured after Feulgen staining using a TV image analysis system.

RESULTS

DNA aneuploidy was assumed if abnormal DNA stemlines, a coefficient of variation of the first DNA stemline > or = 10%, or cells > 9c were observed. On this basis the prevalence of DNA aneuploidy in mesotheliomas was 83% for cytologic and 84% for histologic material. In effusions of metastatic carcinomas it was 100%. None of the 100 reactive effusions revealed DNA aneuploidy (prevalence, 0%). Positive predictive value for mesotheliomas was 100%; negative predictive value was 88% for cytologic and 82% for histologic material. Positive predictive value for metastatic carcinomas was 100%; negative predictive value was 100%. Seventy-two percent of the mesotheliomas revealed their greatest stemline within the range 1.80c-2.20c, whereas none of the metastatic carcinomas showed this stemline position.

CONCLUSION

DNA image cytometry might be a very sensitive and highly specific, additional tool for identification of neoplastic cells in effusions as well as for the differential diagnosis of mesothelioma vs. metastatic carcinoma of the serous membranes.

Pretreatment of rabbits with either hirudin, ancrod, or warfarin significantly reduces the immediate uptake of fibrinogen and platelets by the deendothelialized aorta wall after balloon-catheter injury in vivo

Fibrinogen and platelets rapidly saturate the exposed subendothelium of a freshly deendothelialized aorta in vivo. As thrombin generated within the site of injury is largely responsible for fibrin(ogen) deposition, we questioned whether various anticoagulant treatments would inhibit uptake of both fibrinogen and platelets in vivo. Rabbits were anticoagulated by pretreatment with either Warfarin, Ancrod, or recombinant hirudin. Each anesthetized, anticoagulated (or saline-injected control) rabbit was injected i.v. with rabbit 51Cr-platelets and 125I-fibrinogen before a balloon-catheter deendothelializing (or sham) injury of the thoracic aorta. At 10 minutes after injury, the rabbit was exsanguinated and the aorta excised. Platelet adsorption by the deendothelialized aorta surface was substantially reduced in anticoagulated rabbits (controls, 2.2x10(5)/mm2; Warfarin-treated, 1.2x10(5)/mm2; Ancrod-treated, 5.3x10(4)/mm2; r-hirudin-treated [5 mg/kg], 5.3x10(4)/mm2), and a significant reduction of fibrinogen associated with the platelet layer (from 5.3 to 1 to 2 pmol/cm2) and within the underlying intima-media layer (from 16.9 to 5 to 6 pmol/cm2) was observed in the r-hirudin-and Warfarin-treated rabbits. The pattern of aorta-deposited 51Cr-platelets and 125I-fibrin in the anticoagulated rabbits corresponded well with an assessment by transmission electron microscopy of aortic tissue samples. We conclude that approximately 70% of fibrinogen uptake is thrombin dependent and that approximately 80% of platelet adsorption depends on codeposited fibrin(ogen) during the 10-minute interval after balloon injury. Pretreatment with an agent that interferes with either thrombin or fibrin production will inhibit the immediate interaction of fibrinogen and platelets with the freshly exposed subendothelium.

Increased auditory cortical representation in musicians

Acoustic stimuli are processed throughout the auditory projection pathway, including the neocortex, by neurons that are aggregated into 'tonotopic' maps according to their specific frequency tunings. Research on animals has shown that tonotopic representations are not statically fixed in the adult organism but can reorganize after damage to the cochlea or after training the intact subject to discriminate between auditory stimuli. Here we used functional magnetic source imaging (single dipole model) to measure cortical representations in highly skilled musicians. Dipole moments for piano tones, but not for pure tones of similar fundamental frequency (matched in loudness), were found to be enlarged by about 25% in musicians compared with control subjects who had never played an instrument. Enlargement was correlated with the age at which musicians began to practise and did not differ between musicians with absolute or relative pitch. These results, when interpreted with evidence for modified somatosensory representations of the fingering digits in skilled violinists, suggest that use-dependent functional reorganization extends across the sensory cortices to reflect the pattern of sensory input processed by the subject during development of musical skill.

Atomic force microscopy in effusion cytology

OBJECTIVE

To investigate whether atomic force microscopy (AFM) in combination with classical light microscopy allows simple identification of surface structures of cells from pleural and ascitic fluids for diagnostic purposes in place of scanning electron microscopy (SEM).

STUDY DESIGN

We examined a total of 180 cells obtained from 9 reactive pleural or peritoneal effusions, 14 associated with carcinomatosis from histologically confirmed tumors and 5 from mesotheliomas. Cells of interest were selected in air-dried, uncovered, May-Grünwald-Giemsa (MGG)-stained smears and subsequently investigated by AFM. Incorporation of a very compact AFM scanner into the nose piece of a conventional Axioscope light microscope allowed alternating application of both techniques.

RESULTS

AFM was able to detect cell surface structures, such as microvilli, phagocytic pits, secretory blebs and lytic holes. The image resolution was sufficient but not as good as that with SEM. We found differences in number, length and diameter of microvilli between cells from mesotheliomas and from metastatic adenocarcinomas.

CONCLUSION

As AFM can be carried out in combination with light microscopy quickly and easily on uncovered, MGG-stained smears, we propose this method as a suitable tool for obtaining additional useful information in routine cytologic diagnosis of effusions.

Study of the human auditory cortices using a whole-head magnetometer: left vs. right hemisphere and ipsilateral vs. contralateral stimulation

Structural and functional asymmetries of the temporal lobe affect language development and may also play a role in a variety of disorders, ranging from specific language impairment to schizophrenia. Whole-head neuromagnetometers allow the noninvasive measurement of functional asymmetries since activity from both hemispheres is recorded simultaneously. In the present study, the location of the auditory cortices and their responsiveness to pure tones was compared between hemispheres in healthy human subjects. Data suggest a greater contralateral than ipsilateral activation. In line with previous findings, sources of responses for the right hemisphere seem to be more anterior than for the left one.

Comparative catabolism of prothrombin and antithrombin in normal and alloxan-diabetic rabbits

Previous studies have shown that alloxan-induced diabetes in rabbits effects a slower release of plasma proteins from the liver, a slower synthesis of 35S-glycosaminoglycan in the extracellular matrix of the arterial wall, and a concurrent reduction in the fractional catabolic rates of several plasma proteins. In the present study, the catabolism of two hemostatic proteins, prothrombin and antithrombin, are compared in alloxan-induced diabetic rabbits (of 6 months' duration) and age-matched control rabbits. Differentially radiolabeled prothrombin and antithrombin were injected intravenously, and arterial blood was sampled over a 7-day period to measure the clearance from plasma. A three-compartment model was used to determine the fractional catabolic rate and compartmental distribution of the two proteins. As observed for other plasma proteins, the whole-body fractional catabolic rates (jt) for prothrombin and antithrombin were significantly less in diabetic rabbits (prothrombin, 0.33 d-1; antithrombin, 0.27 d-1) than in control rabbits (prothrombin, 0.37 d-1; antithrombin, 0.30 d-1; P < .001 and P < .005, respectively). In absolute terms, the catabolism of antithrombin and prothrombin in diabetic rabbits was 5.1 and 6.2 mg.kg-1.d-1, respectively, equivalent to a molar ratio for antithrombin to prothrombin of 0.94. For the control rabbits, catabolism accounted for 6.3 mg.kg-1.d-1 of antithrombin and 7.3 mg.kg-1.d-1 of prothrombin, equivalent to a molar ratio of 1.01. The fractional distribution of these proteins was not significantly different within the intravascular and extravascular spaces in diabetic and control rabbits. The decreased catabolic rates observed for prothrombin and antithrombin in diabetic rabbits conform with results obtained previously for other plasma proteins, and probably reflect a generally decreased rate of plasma protein production by diabetic rabbit liver compared with control liver.

AAC-11, a novel cDNA that inhibits apoptosis after growth factor withdrawal

Many growth factors and cytokines act as cellular survival factors by preventing programmed cell death (apoptosis). However, the specific genes and corresponding proteins that mediate survival are poorly defined. To identify potential survival genes, a cDNA library was prepared from murine fibroblasts and screened by a functional expression cloning approach. A 1023-bp cDNA, AAC-11, was identified that encodes a protein of approximately 25 kDa. The AAC-11 gene shows strong species conservation and is ubiquitously expressed in embryonic and adult tissues with multiple transcripts, as well as in various human tumor cell lines. The predicted protein contains a leucine zipper domain but lacks a DNA-binding domain. BALB/c3T3 fibroblasts that were stably transfected with AAC-11 cDNA were viable in serum-free medium for up to 12 weeks. The protective action of AAC-11 was abolished by mutation of leucines to arginines within the leucine zipper domain. We also isolated a longer AAC-11 cDNA that codes for up to an additional 290 amino-terminal amino acids but did not protect against apoptosis. The cDNA for human AAC-11 was identified and exhibits strong homology with the murine species and retains the leucine zipper domain. Western immunoblots of BALB/c3T3 cells using rabbit anti-AAC-11 polyclonal serum revealed a major native 55-kDa AAC-11 protein and a minor 25-kDa protein corresponding to the long and short forms of AAC-11 cDNA, respectively. In summary, we report a cDNA whose expression supports cell viability after withdrawal of growth factors. The corresponding native protein may function as a novel inhibitor of apoptosis.

High-resolution mapping and transcript identification at the progressive epilepsy with mental retardation locus on chromosome 8p

Progressive epilepsy with mental retardation (EPMR) is an autosomal recessive central nervous system disorder characterized by childhood onset epilepsy and subsequent mental retardation. The locus for EPMR has been mapped to human chromosome 8p23. We recently reported the construction of a YAC contig across the 4 centimorgan minimum genetic region that harbors the disease locus. We now report further delineation of the critical region to <700 kb. Our mapping strategy relied on the identification of nine novel microsatellite markers and the construction of a complete BAC contig across the critical region. Several partial gene sequences have been identified from the region and are being analyzed as candidate genes for EPMR.

Magnetic brain imaging of extinction processes in human classical conditioning

By recording neuromagnetic events during aversive classical conditioning, we examined the extinction of a previously described conditioned response. Averaging over non-reinforced exposures to the conditioned stimulus revealed magnetic activity in the secondary somatosensory and insular cortices, appearing between 110 and 140 ms after the omitted unconditioned electric shock. We suggest this activity to be elicited by the discrepancy between shock expectancy and perceptual processes associated with the omission of the unconditioned stimulus, reflecting one of several brain processes in extinction.

Increased fetal colonic muscle contractility following glucocorticoid and thyroxine therapy: implications for meconium passage

The incidence of meconium-stained amniotic fluid increases with advanced gestational age and fetal stress, and meconium passage is likely dependent on fetal colonic muscle function. Antenatal hormone exposure improves fetal pulmonary and cardiovascular function. We hypothesized that in utero exposure to steroid or thyroid hormones effect an increase in fetal distal colonic muscle contractility. In a randomized controlled study 126-day (term 145 days) ovine fetuses were treated with a single ultrasound-guided intramuscular injection of 0.5 mg/kg betamethasone (n = 5), betamethasone plus 60 micrograms/kg thyroxine (n = 5), or saline (n = 7). After 48 h, fetuses (128 days) were delivered, distal colon segments were removed, and peak tension responses to bethanechol (10(-8) to 10(-3) M) characterized in vitro. Peak muscle tensions were significantly greater in fetuses exposed to combined betamethasone and thyroxine therapy (989 +/- 190 g/cm2) than in saline-treated animals (509 +/- 91 g/cm2). There was difference in the maximum tension response between betamethasone alone (559 +/- 75 g/cm2) and the saline animals. The bethanechol ED50 values (2.1 +/- 0.5 x 10(-5) M) were not different among the three groups. Antenatal fetal betamethasone and thyroid hormone treatment increases fetal colonic muscle contractility. We speculate that endogenous or exogenous fetal maturational agents may facilitate the passage of meconium.

An evaluation of a nurse extern program

Externships are meant to bridge the gap between the educational and practice setting for nursing. This project began with discussions of outcomes for nurse extern programs. The Schutzenhofer Nurse Activity Scale and the Meleis Nurse Self-Description Form were used to measure identified outcomes of professional activities and autonomy. Forty-one participants began the study, but 33 completed the pretest and posttest both. Analysis of data showed a positive correlation in Posttest 1 between age and the Meleis Nurse Self-Description Form (NSDF). Dimensions of professional activity changed most in older students. At the end of Phase 2, analysis of data showed significantly greater professional autonomy. However, no significant change in NSDF was seen throughout time. Participants reported increased self confidence.

A proposed framework for teaching and evaluating critical thinking in nursing

Critical thinking is now an explicit National League for Nursing outcome requirement for nursing education programs, and all nursing faculty currently are expected to teach and evaluate critical thinking. However, most of the related literature is theoretical and not on the practical level that might be directly usable by faculty. This article presents a beginning framework developed by a faculty task force at the Indiana University School of Nursing for teaching and evaluating critical thinking. The conceptual definition of critical thinking underlying the framework reflects the efforts of several hundred experts from various disciplines, is maximally inclusive, and lends itself well to operationalization in the nursing context. The task force made two assumptions for this project: first, that the principles of rational thinking are essentially the same at every educational level, although the expertise expected of students at different educational levels certainly differs; and, second, that at this time a focus on operational as opposed to theoretical definitions for the six identified components of critical thinking (interpretation, analysis, evaluation, inference, explanation, and self-regulation) would be particularly useful for faculty and student understanding.

Comparative metabolism and distribution of rabbit heparin cofactor II and rabbit antithrombin in rabbits

The metabolic characteristics of two rabbit plasma thrombin inhibitors, heparin cofactor II (HCII) and antithrombin (AT), have been compared in healthy young rabbits. Purified HCII and AT-alpha were differentially radiolabeled (125I, 131I) and injected intravenously; blood samples were taken at prescribed intervals over 7 days. From the plasma clearance curves of protein-bound radioactivities, fractional catabolic rates and compartmental distributions were calculated using a three-compartment model. The whole body fractional catabolic rate for HCII (jt, 0.43/day, equivalent to t1/2 = 1.61 days) was significantly faster than for AT (jt, 0.37/day; t1/2 = 1.89 days; P < 0.005). The fractional distribution of HCII in the intravascular compartment (Ap, 0.20) and in the extravascular compartment (Ac, 0.63) differed significantly from AT (Ap, 0.30; Ac, 0.56). From the catabolic data and blood concentrations, absolute quantities of HCII and AT catabolized by a 3-kg rabbit amounted to 12.8 and 19.9 mg/day, respectively, equivalent to a molar ratio, AT/HCII, of 1.7. The catabolic molar ratio was compared with the relative release rates of HCII and AT from perfused rabbit livers. Both proteins were released from the liver, the molar ratio in the perfusate rising to approximately 1.4 at 2.5 h. This report increases our understanding of the in vivo dynamics of these two proteins.

Extracorporeal shockwave lithotripsy for common bile duct stones

BACKGROUND

Successful extraction of common bile duct stones after endoscopic sphincterotomy may be achieved in 86-96 per cent of cases. However, some stones are too large to be removed in this manner. This study looks at the role of extracorporeal shock-wave lithotripsy to break up common bile duct stones as an adjunct to sphincterotomy in patients with stones greater than 10 mm in size.

METHODS

Twenty-seven patients with large (10-35 mm) common bile duct stones were treated with piezoelectric generated extracorporeal shock-wave lithotripsy (ESWL) following failed stone extraction after endoscopic sphincterotomy (ES). The stones were visualized ultrasonographically and a piezolith 2300 Wolf lithotripter used to administer the shockwaves.

RESULTS

Visualized stone fragmentation was reported in 20 of 48 sessions. Clearance of targeted stones was achieved in 18 of the 27 patients, but actual duct clearance was demonstrated in only 17 of the 27. There were few adverse effects and mortality was nil.

CONCLUSION

This study concludes that ESWL following failed ES is a useful additional treatment option for very large bile duct stones, but should only be used after surgical risk and past history of biliary disease have been carefully reviewed and found to contraindicate conventional surgical management. An algorithm of treatment options for common bile duct stones is presented.

Combined EEG and MEG recordings of visual 40 Hz responses to illusory triangles in human

EEG and MEG were simultaneously recorded to study the visual gamma-band (30-70 Hz) responses. The electrical gamma-band response phase-locked to stimulus onset can be subdivided into a central component at 39 Hz and an occipital component at 36 Hz. A new high-frequency magnetic phase-locked response recorded over the occipital lobe is described. Its topography is complex and probably reflects the activity of multiple sources. Both electrical and magnetic high-frequency responses differ in topography from the low-frequency responses in the same latency range, suggesting that at least partially distinct sources are involved. The existence of a non-phase-locked 40 Hz component around 280 ms is confirmed in EEG data but is not detectable in MEG data.

Gallstone removal with a modified cholecystoscope: an alternative to cholecystectomy in the high-risk patient

BACKGROUND

Symptomatic gallstones in patients who are at high risk from or who wish to avoid anesthesia may be difficult to treat, especially if the gallstones are unsuitable for oral dissolution or lithotripsy. We describe our experience with a minimally invasive surgical method of gallstone extraction under thoracic epidural or intercostal anesthesia.

STUDY DESIGN

Eight-one patients who were either at high risk from or did not wish to undergo general anesthesia or those who wished to conserve their gallbladder underwent percutaneous cholecystolithotomy with a modified cholecystoscope. Of these patients, 63 (78 percent) were in American Society of Anesthesiology grades III and IV and 28 (35 percent) had thick-walled, diseased gallbladders.

RESULTS

Gallstones were completely cleared in 66 (81 percent) patients and complete symptom relief was obtained in more than 95 percent of these patients. There were no deaths or serious complications.

CONCLUSIONS

Percutaneous cholecystolithotomy under regional anesthesia is an effective means of gallstone treatment in selected high-risk patients.

Protein characterization of Australian spotted fever group rickettsiae and monoclonal antibody typing of Rickettsia honei

Rickettsial proteins rOmp A and rOmp B exist in both Rickettsia australis and Rickettsia honei but differ in molecular weight and antigenicity; in addition, they produce distinct immunogenic responses and appear to be to conformationally dependent antigens. Species-specific monoclonal antibodies for other spotted fever group rickettsial species did not react with R. honei. A PCR product of the repeat region of the rOmp A gene from R. honei was amplified and calculated to contain 11 repeat units.