Production of interferon byTheileria annulata-andT. parva-infected bovine lymphoid cell lines

Theileria annulata andT. parva-infected lymphoblastoid cells were examined for their capacity to produce interferon (IFN). Supernatants of such cells were tested in biological assay for their antiviral activity. OnlyT. parva-infected cells of T-cell origin were capable of producing IFN-gamma. Supernatants of some but not allT. annulata-infected cells showed also antiviral activity, which was greatly reduced after exposure to a pH of 2. Northern-blot analysis of the cells using an IFN-gamma cDNA probe confirmed the results obtained forT. parva-infected cells in a biological assay. No IFN-gamma mRNA was detected inT. annulata-infected cells. The importance of IFN for the pathogenesis of theileriosis is discussed.     

Mapping of retinal and geniculate neurons onto striate cortex of macaque

A unity ratio between geniculate and ganglion cells can be shown in the macaque visual system. Comparison of the densities (cells/deg2) in the dorsal lateral geniculate nucleus (dLGN) of parvocellular (P) and magnocellular (M) cells, respectively, representing color-opponent and broad-band ganglion cells, with cortical magnification (mm2/deg2) gives the number of afferents per square millimeter in striate cortex (V1). For P cells, this afferent density rises only slightly with eccentricity, indicating that V1 magnification is approximately proportional to the density of P cells. The density of cytochrome oxidase puffs in V1 also rises only slightly with eccentricity. As a result, the number of P-cell afferents per puff-centered module is remarkably constant throughout V1. Our findings thus support a novel hypothesis of peripheral scaling, in which V1 cortical magnification is based on the mapping of just 1 class of afferent onto V1 modules. This "P-cell module" in V1 may be composed of submodules corresponding anatomically to the honeycomb cell in layer 4A of V1 and physiologically to a minimal complete set of color-opponent ganglion cells. In contrast, the afferent density of M cells rises steeply with eccentricity, so that the reciprocal of their afferent density, the cortical "domain" of M cells, declines with eccentricity. This decline is similar to that of point-image area in V1. As a result, the number of M cells per point-image area is nearly constant. This quantity is analogous to the receptive-field coverage factor in the retina, which for M cells is fairly constant and greater than unity at all eccentricities. The results show fundamental differences between the neural maps of these 2 major cell types, differences that are likely to have psychophysical consequences.     

Age-dependent variation of T1 and T2 relaxation times of adenocarcinoma in mice

The T1 and T2 values of adenocarcinoma EO 771 inoculated into the hind leg of mice are characterized and correlated with the histopathologic state of the tumor. Growth-dependent changes (indicated by a T1 of 630-910 msec and a T2 of 68-185 msec) can be separated into four characteristic phases. The increase in relaxation times in the early phases (A and B) is due to an increasing amount of viable tumor tissue relative to normal muscle tissue. In the later phases (C and D), a decline of the relaxation parameters is observed that is parallel to an increase in the fraction of necrotic tissue. By multiexponential analysis, two relaxation components (indicated by and, respectively) for T1 and T2 and the corresponding fractions alpha 1 and alpha 2 can be observed for both tumor and surrounding muscle tissue. A tissue criterion ("magnetic resonance fingerprint") is defined by a combination of these multiple parameters. This criterion allows separation of not only muscle and tumor tissue but also viable (early state) and necrotic (late state) tumor tissue.     

Giving a voice to patient experiences through the insights of pragmatism

As a philosophical position, pragmatism can be critiqued to distinguish truth only with methods that bring about desired results, predominantly with scientific enquiry. The article hopes to dismiss this oversimplification and propose that within mental health nursing, enquiry enlightened by pragmatism can be anchored to methods helping to tackle genuine human problems. Whilst pragmatists suggest one reality exists, fluctuating experiences and shifting beliefs about the world can inhabit within; hence, pragmatists propose reality has the potential to change. Moreover, pragmatism includes being cognisant of what works to whom reality concerns, making reality context-driven, with a view to understand how actions shape experiences so what is generated has usefulness. Hence, it somewhat follows pragmatism can inform mental health nursing, after all, nursing is a discipline of action, and awareness is needed in how actions produce experiences that patients find helpful. Given the principles of recovery are preferably adopted in mental health care, the paper will explore how pragmatism can help nurses move towards that goal; specifically, with patients voicing their experiences. This is because like pragmatism, recovery subscribes to hope that reality can progress, and through meaningful experiences and beliefs, patients have expertise about personal difficulties alongside how life may flourish, despite mental illness.     

Nonhereditary p53 mutations in T-cell acute lymphoblastic leukemia are associated with the relapse phase

We have previously reported that greater than 60% of human leukemic T- cell lines possess mutations in the p53 tumor suppressor gene. To determine whether T-cell acute lymphoblastic leukemia (T-ALL) patient samples possess p53 mutations, we screened peripheral blood-and bone marrow-derived leukemia samples, taken at diagnosis and at relapse, for p53 mutations. Exons 4 through 9 and selected intron regions of the p53 gene were analyzed using polymerase chain reaction-single-strand conformation polymorphism and direct sequencing. p53 mutations were found in 0 of 15 T-ALL diagnosis samples, as compared with 10 of 36 (28%) T-ALL relapse samples. To determine whether p53 mutations play a role in the recurrence (relapse) of T-ALL, two special groups of T-ALL patients were studied: (1) a group of 8 relapse patients whose disease was refractory to chemotherapeutic treatment, and (2) a group of 6 "paired" T-ALL cell samples from patients for whom we possess both diagnosis and relapse samples. Three of 8 relapsed patients (37.5%) whose disease was refractory to the reinduction of remission by chemotherapy possessed missense mutations of the p53 gene. All 3 cases had mutations in exon 5. Among the paired samples, 3 of 6 patients harbored p53 mutations at disease recurrence, but possessed only wild- type p53 alleles at diagnosis. One case had mutation on exon 4, 1 case in exon 5, and 1 case in exon 8 with loss of heterozygosity. These data clearly indicate that recurrence of T-ALL is associated with missense mutations in p53. Our results indicate that (1) mutations of p53 do occur in T-ALL in vivo, and such mutations are associated with the relapse phase of the disease; and (2) p53 mutation is involved in the progression of T-ALL. This conclusion is supported by our observation that the introduction of T-ALL-derived mutant p53 expression constructs into T-ALL cell lines further increases their growth rate in culture, enhances cell cloning in methylcellulose, and increases tumor formation in nude mice.     

Antibiotic Administration in Patients Undergoing Common Surgical Procedures in a Community Teaching Hospital: The Chaos Continues

The influence of recently published guidelines by the Surgical Infection Society (SIS) on current surgical practice are not well documented. The appropriateness of antibiotic administration in a cohort of surgical patients undergoing elective and emergency surgery in a department of surgery in an urban, community-based, private, 560-bed teaching hospital was retrospectively reviewed. The following were the criteria defining administration as appropriate as modified from SIS guidelines: Prophylactic use: (1) started prior to operation; (2) spectrum appropriate to the specific operation; (3) duration ≤ 24 hours. Therapeutic use: (1) started prior to operation; (2) spectrum appropriate to pathology; (3) Duration ≤ 24 hours for contamination or “resectable” infection and ≤ 5 days for established infection in the absence of clinical evidence of persisting infection. Any switchover from an appropriate agent to another appropriate or inappropriate agent in the same patient in the absence of microbiologic or clinical indication was considered inappropriate administration. We reviewed the charts of 211 randomly selected patients who underwent elective (n= 132) or emergency (n= 79) procedures during 1996. The operations included gastrectomy (n= 22), appendectomy (n= 27), open (n= 5) or laparoscopic (n= 27) cholecystectomy, colectomy (n= 28), hysterectomy (n= 8), laparotomy for intestinal obstruction (n= 11), mastectomy (n= 26), and ventral hernia repair (n= 37). A total of 17 antibiotics were used for prophylaxis and 21 for therapy. In 156 patients (74%) the administration was considered inappropriate. Eight patients in the inappropriate group developed diarrhea (two cases of Clostridium difficile-induced colitis) compared to two cases of diarrhea in the appropriate group (nonsignificant). The average duration of administration after elective and emergency operations was 3.3 and 5.7 days, respectively. The total expense for excessive duration of administration was $18,533. Many surgeons are not familiar with the spectrum of antimicrobials and often do not distinguish between prophylactic and therapeutic administration. Antibiotic usage in current surgical practice is often inappropriate, excessive, and chaotic.     

Digital image capture and automated analysis of posterior capsular opacification.

PURPOSE: To develop and validate a digital imaging and analysis technique for assessing the extent of posterior capsular opacification after cataract surgery. METHODS: Retroillumination images of the posterior capsule were obtained by using a digital camera mounted on a slit lamp. The images were analyzed using an available image analysis software program. The image acquisition and analysis techniques were tested for face validity, reproducibility, and the ability to detect progression of capsular opacity over time. RESULTS: Digital retroillumination images were obtained without patient discomfort. Automated analysis of images correlated well with clinical grading both at slit lamp examination and when looking at the images themselves (Spearman's correlation coefficient >0.7). Analysis of images taken at different times showed high reproducibility (intraclass correlation >0.9), and the system was able to identify progression of capsular opacity over a 2-year period with a mean increase of 15.8% in progressors versus an increase of 0.6% in nonprogressors (P < 0.05). CONCLUSIONS: Digital retroillumination images of the posterior capsule can be obtained reliably, and automated analyses correlate well with clinical assessment. The system presented here uses commercially available instruments and software, and it is practical for use in longitudinal studies of posterior capsule opacification. It is reliable, easy to use, and can detect small changes in the percentage area covered by posterior capsule opacification over time.