PNKT-4B is an aneuploid cell line derived from a herpesvirus-induced renal adenocarcinoma of Rana pipiens that displays restricted invasion at 21 degrees C or cooler and invasion at 23 degrees C through 28 degrees C. Metaphase chromosomes obtained from subcultures (passages 297; 345-347) grown at 18 degrees C or 28 degrees C were Giemsa stained or N-banded with acidic silver nitrate. Cells grown at 18 degrees C displayed a modal chromosome number of 41, while 28 degrees C cultures displayed a modal number of 40. The distribution of the chromosomes suggests that the two temperatures may be allowing growth of different subclonal populations. N-banding of chromosomes at both temperatures revealed an increase of active nucleolar organizer regions (NORs) over normal frog tissues, 2/2N. Analysis of 200 N-banded spreads from cells grown at each temperature revealed modal numbers of 9 NORs/cell and modal numbers of 6 NOR-containing chromosomes/cell. Nine specific NOR-containing chromosomes were identified and scored. Similar distributions were observed at 18 degrees C and 28 degrees C. The data imply that the modal number of PNKT-4B has shifted since it was first described, 39, and differs at invasion-permissive and -restrictive temperatures. Increased numbers of active NORs and alterations of NOR-containing chromosomes imply an amplification of rDNA over the amount in normal frog.

Adenocarcinoma↗

PubMedDate not supplied

Effects of preparatory set and task demands on auditory event-related potentials.

Different instructional sets for moderate vs. high response speeds were given in a visual letter-matching task. On 50 percent of the trials an auditory probe requiring a simple RT response was presented in one of four temporal locations within the ongoing visual task. Probe locations were selected to maximize differences in the processing demands of the dual, auditory-visual task (see Posner and Boies, 1971). The N100 of the event-related potential associated with the auditory probe was larger under the high response speed set than under the moderate set, regardless of probe location. P300 amplitude was also greater under the high speed set relative to the moderate set but only when the task demands were high. The results were interpreted in terms of the interaction between arousal and task demands and a neural inhibition model of the P300 was discussed.

Adult↗

PubMedDate not supplied

Exposure of neonatal male rats to estrogen induces abnormal morphology of the penis and loss of fertility.

The research objectives are to determine whether estrogen-induced infertility is associated with abnormal morphology of the penis and if morphological alterations can be reversed by testosterone (T). Male pups received diethylstilbestrol (DES) on alternate days from postnatal days 2 to 12. They received T or empty implants at 180 days, were tested for fertility at 188 days, and terminated at 200 days. While 5/7 control males sired pups, only 1/6 did in the DES group, and 0/8 in the DES plus T group. In addition to reductions in penile length and weight, the novel structural change induced by DES, and not reversed by T, was a replacement of cavernous spaces by fat cells in the penis body. Hence, T substitution for 8 days at adulthood did not reverse infertility in rats treated neonatally with DES and provided evidence that infertility probably resulted from absence of cavernous spaces and/or accumulation of fat cells in the penis body.

Age Factors↗

PubMedDate not supplied

A cyclooxygenase-2 inhibitor (SC-58125) blocks growth of established human colon cancer xenografts.

Selective COX-2 inhibitors reduce adenoma formation and cancer progression in rodent models of colorectal cancer. To assess the therapeutic activity of selective COX-2 inhibitors, we tested the effect of SC-58125 treatment on the growth of human colon carcinoma cells in nude mice. Delaying treatment by 2, 4, or 7 weeks following implantation of the carcinoma cells resulted in a significant inhibition of tumor growth. Furthermore, short-term (48 hours) treatment with SC-58125 was sufficient to attenuate tumor growth for up to 15 days. SC-58125 treatment did not alter the rate at which cells underwent apoptosis, but did result in a delayed progression through the cell cycle at the G(2)/M transition. Accordingly, p34(cdc2) protein levels and activity were decreased following SC-58125 treatment. We conclude that SC-58125 primarily exerts a cytostatic effect in vivo, which is likely to be mediated through inhibition of progression through the G(2)/M phase of the cell cycle.

Animals↗

PubMedDate not supplied

Analysis of pesticide residues in hops and their extraction by liquid CO2 during the production of hop extracts.

A method has been developed for analysing pesticide residues in whole hops, hop pellets and hop extracts by GC-MS. Five batches of hop pellets containing nine different pesticides (triadimefon, dicofol, mephosfolan, bupirimate, cyhalothrin, tetradifon, endosulfan, pyrazophos and total bisdithiocarbamates) were extracted with liquid CO2. Pesticide concentrations in the original hop pellets and the extracts were determined. The pesticides were concentrated by the extraction process (concentration factor 1.3-8.3), except for the bisdithiocarbamates, which were not extracted. When the same amount of bitterness was added into the brewing process using liquid CO2 extract as opposed to hop pellets, for most of the pesticides proportionately less pesticide was added. However, for two pesticides (dicofol and triadimefon) corrected residue levels were similar to, or in some cases slightly higher than, those in hop pellets.

Beer↗

PubMedDate not supplied

Median nerve neuropathy at the wrist.

Explore the source record for details and available documents.

Adult↗

PubMedDate not supplied

Primary cultures of rhesus placental syncytiotrophoblasts are permissive for SIV infection.

Primary cultures of rhesus syncytiotrophoblasts incubated with SIVdeltaB670, SIVmac251, or SIVmac239 produced readily detectable virus in the supernatant for up to three weeks after infection. At four weeks, cells generally failed to release virus but placental cell lysates and placental cells cocultured for 24 hours with uninfected CEM x 174 cells were able to transmit infection. The presence of virus was confirmed by electron microscopy and PCR amplification of viral sequences from trophoblast genomic DNA. SIV p27 antigen was localized by immunostaining primarily in syncytiotrophoblasts.

Animals↗

PubMedDate not supplied

Dupuytren's contracture.

Dupuytren's contracture is a fibroproliferative disorder of autosomal dominant inheritance that most commonly affects men over age 60 who are of Scandinavian, Irish, or eastern European descent. Local microvessel ischemia in the hand and specific platelet-derived and fibroblast growth factors act at the cellular level to promote the dense myofibroblast population and altered collagen profiles seen in affected tissue. Surgical treatment depends to some degree on patient preference and a clear understanding of the possible complications and considerable postoperative therapy commitment. Operative management is appropriate when metacarpophalangeal or proximal interphalangeal joint contracture exceeds 30 degrees. A volar zigzag Brunner incision in the digit and palm provides reliable exposure and leads to predictable healing in most cases. The mainstay of postoperative hand therapy is early active-flexion range-of-motion exercises to restore grip strength. A nighttime extension splint is often used for several months postoperatively to maintain the correction achieved in the operating room. Early recurrence of disease is most common in individuals with Dupuytren's diathesis; use of full-thickness skin grafts may be helped for these patients.

Dupuytren Contracture↗