Inhibition of acetylcholine release from presynaptic terminals of skate electric organ by calcium channel antagonists: a detailed pharmacological study

Release of acetylcholine (ACh) from the presynaptic terminals in skate electric organ was tested for its sensitivity to calcium channel antagonists. A pharmacological profile was established by measuring inhibition of K(+)-stimulated release of [3H]ACh from prelabelled tissue slices. Peptide antagonists of N-type (omega-conotoxins GVIA and MVIIA) and P-type (omega-agatoxin-IVA) channels had no effect, whereas both omega-conotoxins MVIIC and SVIB produced concentration-dependent inhibition and could completely block ACh release. omega-Conotoxin GVIA and omega-agatoxin IVA did not attenuate the block by omega-conotoxin MVIIC. The inorganic ions, Cd2+ and Ni2+, also produced a full inhibition of release (Cd2+ > > Ni2+) and Gd3+ a partial one. Drugs targeting L-type channels (diltiazem, nifedipine and verapamil) at low microM concentrations and a synthetic analogue of the polyamine toxin from funnel web spider venom (sFTX) at 1 mM were all non-inhibitory. Inhibition by omega-conotoxins MVIIC (IC50 25 nM) and SVIB (IC50 500 nM) was reversible and modulated by external concentrations of Ca2+. Inhibitory potency was increased by lowering and decreased by elevating external Ca2+. This "antagonistic" effect of Ca2+ was also seen with Cd2+ inhibition. The inhibitory potency of omega-conotoxin MVIIC was unaffected by predepolarisation. End plate potentials generated by release of endogenous ACh in electrically-stimulated slices were also reversibly blocked by Cd2+ and omega-conotoxins MVIIC and SVIB but were unaffected by omega-conotoxin GVIA and omega-agatoxin IVA. It is concluded that ACh release in skate electric organ depends on presynaptic calcium channels which have different pharmacological properties from established sub-types.

Estimating variance functions in developmental toxicity studies

The presence of intralitter correlation is a well known issue for analysis of the developmental toxicology data. The intralitter correlation coefficients observed in developmental toxicology data are generally different across dose groups. In this paper we use a generalized estimating equation procedure to model jointly the mean parameters and the intralitter correlation coefficients as functions of dose levels. Our procedure is similar to that used by Prentice and Zhao (1991, Biometrics 47, 825-839) for estimating the mean and variance parameters.

Characteristics of a human N-type calcium channel expressed in HEK293 cells

The human alpha 1B-1 alpha 2b beta 1-2 Ca2+ channel was stably expressed in HEK293 cells producing a human brain N-type voltage-dependent calcium channel (VDCC). Whole cell voltage-clamp electrophysiology and fura-2 based microfluorimetry have been used to study its characteristics. Calcium currents (ICa) recorded in transfected HEK293 cells were activated at potentials more depolarized than -20 mV with peak currents occurring at approx + 10 mV in 5 mM extracellular CaCl2. ICa and associated rises in intracellular free calcium concentrations ([Ca2+]i) were sensitive to changes in both the [Ca2+]o and holding potential. Steady-state inactivation was half maximal at a holding potential of -60 mV. Ba2+ was a more effective charge carrier than Ca2+ through the alpha 1B-1 alpha 2b beta 1-2 Ca2+ channel and combinations of both Ba2+ and Ca2+ as charge carriers resulted in the anomalous mole fraction effect. Ca2+ influx into transfected HEK293 cells was irreversibly inhibited by omega-conotoxin-GVIA (omega-CgTx-GVIA; 10 nM-1 microM) and omega-conotoxin-MVIIA; 100 nM-1 microM) whereas 1 microM) whereas no reductions were seen with agents which block P or L-type Ca2+ channels. The inorganic ions, gadolinium (Gd3+), cadmium (Cd2+) and nickel (Ni2+) reduced the ICa under voltage-clamp conditions in a concentration-dependent manner. The order of potency of the three ions was Gd3+ > Cd2+ > Ni2+. These experiments suggest that the cloned and expressed alpha 1B-1 alpha 2b beta 1-2 Ca2+ channel subunits form channels in HEK293 cells that exhibit properties consistent with the activity of the native-N-type VDCC previously described in neurons.

Affinity purification of rat cortical and chicken forebrain synaptosomes using a biotinylated derivative of omega-CgTx GVIA

We describe a magnetophoretic method for the affinity purification of synaptosomes expressing omega-CgTx GVIA-sensitive, N-type voltage-sensitive calcium channels (VSCCs). The method utilizes a biotinylated derivative of omega-CgTx GVIA which retains its ability to displace [125I] omega-CgTx GVIA from its binding sites on rat synaptic membranes. When coupled to streptavidin coated magnetizable beads, the hexanoyl spacer between omega-CgTx GVIA and the biotin:streptavidin bead complex is sufficiently long to allow flexibility of the toxin to bind to its receptor on synaptosomes. We have used this ligand successfully to isolate deaggregated synaptosomes from the parent fractions of chicken forebrain and rat cortex. In the chicken synaptosome parent fraction, omega-CgTx GVIA (1 nM-1 microM) produced a concentration-dependent block of the KCl-induced intracellular free Ca2+, [Ca2+]i, elevation with an IC50 of 28 nM. After affinity magnetophoresis no increase in [Ca2+]i elevation was observed in either the bound or unbound fractions. In the rat synaptosome parent fraction, the KCl-induced increase in free intracellular Ca2+ ([Ca2+]i) elevation was partially blocked by omega-CgTx GVIA (17 +/- 2% / 1 microM) and to a greater extent by omega-Aga IVA (55 +/- / 1 microM): a combination of the two toxins was additive (72 +/- 4% / 1 microM). The block obtained by omega-CgTx GVIA (1 microM) in the unbound fraction was reduced to 3 +/- 2%, whereas that by omega-Aga IVA (1 microM) increased to 82 +/- 3%. The block obtained by a combination of both toxins (83 +/- 2%) was the same as that with omega-Aga IVA alone (82 +/- 3%). No increase in free [Ca2+]i elevation was observed in the bound fraction although single synaptosome-like structures, displaying synaptophysin immunoreactivity, were detected on the beads. We conclude that omega-CgTx GVIA-sensitive N-type calcium channels are present on all chicken forebrain synaptosomes but only a subset of rat cortical synaptosomes.

A full likelihood procedure for analysing exchangeable binary data

A full-likelihood procedure is proposed for analyzing correlated binary data under the assumption of exchangeability. The binomial and beta-binomial models are shown to occur as special cases correspondingly, respectively, to the choice of degenerate and beta-mixing distributions. For a finite exchangeable binary sequence of random variables, expressions for the joint distribution, moments, and correlations of all orders are derived. Maximum likelihood estimates of the moments of all orders are computed and used to estimate correlations and the distribution of the number of responses in a cluster. In an application to developmental toxicology data analysis, the procedure introduced is compared with a beta-binomial and a generalized estimating equation procedure in which mean response and intralitter correlation are linked to dose.

3-D reconstruction of Ir-192 implant dosimetry for irradiating gingival carcinoma on the mandibular alveolar ridge

A recurrent cancer in the gingiva has been treated by specially fabricating a dental acrylic appliance. This replica of the floor of the mouth, gums, and teeth was constructed with the use of a vinyl polysiloxine impression material. The tumor boundaries were marked in the fabricated appliance with four metal wires to localize the surface and periphery of the tumor. The appliance was molded to hold Ir-192 wires in near contact with the target surface and to allow afterloading. A specially designed lead shield was imbedded onto the dorsal surface of the appliance so as to reduce dose to the tongue and maxillary structures of the mouth. Simulation films and 3-D treatment planning were used to generate isodose distributions and to allow preplanning. The dose calculation algorithm was modified to account for the attenuation in the lead shield represented in three dimensions. The Ir-192 mold was successfully applied for 38 hours in two sessions 1 week apart.

Novel pharmacological sensitivity of the presynaptic calcium channels controlling acetylcholine release in skate electric organ

The presynaptic terminals of skate (Raja montagui) electric organ were tested for their sensitivity to calcium channel antagonists. Acetylcholine (ACh) release and the elevation of intraterminal Ca2+ concentrations triggered by K+ depolarisation were studied. ACh release was measured as 3H efflux from slices of organ prelabelled with [3H]choline. Depolarisation caused a marked, Ca(2+)-dependent increase in 3H efflux that was completely blocked by 100 microM Cd2+ and by 300 nM omega-conotoxin-MVIIC (MVIIC). Inhibition by MVIIC was concentration dependent (IC50 of approximately 20 nM) and reversible. No inhibition was seen with nifedipine (5 microM) or the two other peptide antagonists studied: omega-conotoxin-GVIA (GVIA) at 5 microM and omega-agatoxin-IVA (Aga-IVA) at 1 microM. In a "nerve plate" preparation (a presynaptic plexus of nerve fibres, Schwann cells, and nerve terminals) changes in intraterminal Ca2+ concentrations were measured by microfluorimetry using fluo-3. An increase in fluorescence, indicating a rise in the free [Ca2+], rapidly followed K+ depolarisation, and this change was restricted to the nerve terminals. This response was insensitive to nifedipine (5 microM), GVIA (5 microM), and Aga-IVA (300 nM) but almost completely abolished by MVIIC (1 microM). MVIIC inhibition was concentration dependent and partially reversible. These results show that the nerve terminals in skate electric organ have calcium channels with a pharmacological sensitivity that is markedly different from the established L, N, and P types in other systems but shares some, but not all, of the features of the recently described Q type.

Roots, fundamental ideas, and principles

Agency history, basic principles, and attitudes influence a comprehensive version of psychiatric rehabilitation.

Omega-conotoxin MVIIC reversibly inhibits a human N-type calcium channel and calcium influx into chick synaptosomes

We have investigated the effects of omega-CmTX MVIIC on the recombinant alpha 1B-mediated calcium channel expressed in HEK 293 cells and on the predominantly N-type calcium channel in chick synaptosomes. omega-CmTX MVIIC potently and reversibly inhibited the calcium current through alpha 1B-mediated calcium channels and inhibited KCl-evoked increases in [Ca2+]i in chick synaptosomes in a concentration-dependent manner.

Growth of tumor derived activated T-cells for the treatment of cancer

This report describes the production of Tumor Derived Activated Cell cultures (TDAC, also called tumor infiltrating lymphocytes) from patient tumor biopsies and our preliminary experience growing these cells to therapeutic levels using artificial capillary bioreactor cultures. TDAC were successfully grown in medium containing Interleukin 2 from 80% of the 113 tumor biopsies tested. There was no significant difference in success (growth to 1 x 10(9) cells) comparing primary and metastatic tumors. Many of the tumors were shipped to the laboratory from distant sites. Success rate did decrease with the length of time for tumor transport. Interleukin 4 was beneficial in the development of 1 of 4 TDAC cultures which did not grow with IL-2 only. Seventy-seven bioreactor cultures were initiated for 31 patients. On the average, 1.9 x 10(9) TDAC were inoculated per bioreactor; 3.3 x 10(10) were harvested in 22 days. Twelve liters of medium were required per 1 x 10(10) TDAC produced. TDAC cultures contained T cells with variable ratios of CD4 to CD8 cells. Secreted granulocyte monocyte colony stimulating factor, interferon gamma and tumor necrosis factor were measured in the bioreactor cartridge conditioned medium. Twenty three patients were evaluated. Partial responses were observed in 4 patients including a dramatic remission of scalp nodules in a patient with renal cancer. Results showed that therapeutic amounts of TDAC cells may be produced in a reasonable and cost effective manner using artificial capillary bioreactor cultures.

Pharmacological characterisation of the calcium channels coupled to the plateau phase of KCl-induced intracellular free Ca2+ elevation in chicken and rat synaptosomes

The effect of various blockers of voltage operated calcium channels (VOCCs) was studied on the non-inactivating, plateau phase of KCl-induced intracellular free Ca2+ ([Ca2+]i) elevation in rat cortical and chicken forebrain synaptosomes. In chicken synaptosomes, omega-CgTx GVIA (0.1 nM to 1 microM) and omega-CgTx MVIIA (0.1 nM to 1 microM), both selective blockers of N-type Ca2+ channels, produced a concentration-dependent inhibition of the plateau phase of [Ca2+]i elevation. omega-CgTx GVIA (IC50 value 28 nM) was more potent than omega-CgTx MVIIA (IC50 value 78 nM), but at submaximal concentrations, took longer to reach its maximum effect (20 min for omega-CgTx GVIA; 10 min for omega-CgTx MVIIA). At 1 microM, the highest concentration tested, each toxin blocked > 85% of [Ca2+]i elevation. The effect of omega-CgTx GVIA on the extent and time-course of inhibition of [Ca2+]i elevation was maintained in a Na(+)-free, choline substituted, medium. omega-Aga IVA (300 nM), a selective blocker of P-type calcium channels, inhibited 28 +/- 5% of [Ca2+]i elevation. The effect of a combination of submaximal inhibitory concentrations of omega-CgTx GVIA (100 nM) and omega-Aga IVA (300 nM) was less than additive. In rat synaptosomes, omega-CgTx GVIA (1 microM) and omega-CgTx MVIIA (1 microM), blocked only 18 +/- 5% and 17 +/- 4% of the plateau phase of free Ca2+ elevation, respectively. omega-Aga IVA produced a concentration-dependent inhibition of [Ca2+]i elevation in this preparation. Threshold inhibition was observed at 1 nM, and maximum inhibition (64 +/- 8%) at 1 microM.(ABSTRACT TRUNCATED AT 250 WORDS)

1 alpha,25-Dihydroxyvitamin D3 rapidly increases nuclear calcium levels in rat osteosarcoma cells

1 alpha,25-Dihydroxyvitamin D3 increases intracellular calcium in rat osteoblast-like cells that possess the classic receptor (ROS 17/2.8) as well as those that lack the classic receptor (ROS 24/1), indicating that a separate signalling system mediates this rapid nongenomic action. To determine the intracellular sites of this calcium increase, cytosolic and nuclear fluorescence (340 nm/380 nm ratio) were measured in Fura 2AM loaded ROS 17/2.8 cells using digital microscopy. Within 5 min, cytosolic fluorescence increased by 29% (P < 0.05) and nuclear fluorescence by 30% (P < 0.01) after exposure to 1 alpha,25-dihydroxyvitamin D3 (20 nM). This effect was blocked by the inactive epimer 1 beta,25-dihydroxyvitamin D3. In an individual cell, cytosolic and nuclear fluorescence increased gradually after 1, 3, and 5 min exposure to vitamin D. Nuclei were then isolated from ROS 17/2.8 cells to directly measure the hormone's effect on nuclear calcium. The calcium content of Fura 2AM loaded nuclei was not affected by increasing the calcium concentration in the incubation buffer from 50 nM to 200 nM. After 5 min, 1 alpha,25-dihydroxyvitamin D3, 20 nM, increased the calcium of isolated nuclei in medium containing 50 nM calcium and 200 nM calcium. 1 beta,25-dihydroxyvitamin D3, 20 nM, had no effect on nuclear calcium but blocked the 1 alpha,25-dihydroxyvitamin D3 induced rise in the isolated nuclei. The results indicate that the nuclear membrane of the ROS 17/2.8 cells contain calcium permeability barriers and transport systems that are sensitive to and specific for 1 alpha,25-dihydroxyvitamin D3.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous burst firing in cat primary auditory cortex: age and depth dependence and its effect on neural interaction measures

1. Neural activity was recorded with two independent electrodes separated by 0.5-2 mm, aligned in parallel, and advanced perpendicular to the surface of the cat auditory cortex. Because the experiments were part of a study into laminar interaction the difference in recording depths for the two independently movable electrodes was never > 100 microns. Multi-unit activity on each electrode was separated on-line into single-unit spike-trains with a maximum variance spike sorting algorithm. Off-line controls on the quality of the spike-train separation were routinely performed. The first aim of this study was to describe the age dependence of spontaneous burst firing and to explore if and how it could be explained by age dependent changes in firing rate. The second aim was to investigate a potential layer dependence on burst firing. The third aim was to describe the effect of burst-removal procedures on the shape, strength, and width of the cross-correlogram and to investigate whether an age dependence in burst firing might account for the previously reported age dependence in correlation strengths. 2. Recordings were made from 237 single units from primary auditory cortex in nine adult cats and from 67 units in seven kittens age 10-52 days. The incidence of burst firing as a function of firing rate, age and depth of recording and unit characteristic frequency was investigated. In addition the effect of burst firing on the strength and width of the central peak in 471 neural pair correlograms was analyzed. 3. Burst firing could be distinguished at many different time scales; bursts lasting of the order of 10 s contained bursts with durations of the order of 1 s, which in turn contained bursts of 30-50-ms duration. The analysis in this paper was restricted to the short-duration bursts. 4. Burst firing on the short-time scale of 50 ms was characterized by relatively well defined intervals between the first two spikes (3-15 ms) followed by higher-order intervals with large spread (range 4-50 ms) but with increasing modal interval value. The typical adult five-spike burst template featured spikes at 0, 3.3, 14.6, 27.2, and 34.8 ms. Burst with fewer spikes showed larger intervals between the first three spikes. 5. The probability of occurrence of isolated spikes, pairs, triplets, etc. showed a power-law dependence on firing rate with a coefficient that was significantly lower than expected under Poisson firing conditions.(ABSTRACT TRUNCATED AT 400 WORDS)

A three-dimensional view of precursor messenger RNA metabolism within the mammalian nucleus

A quantitative three-dimensional analysis of nuclear components involved in precursor messenger RNA metabolism was performed with a combination of fluorescence hybridization, immunofluorescence, and digital imaging microscopy. Polyadenylate [poly(A)] RNA-rich transcript domains were discrete, internal nuclear regions that formed a ventrally positioned horizontal array in monolayer cells. A dimmer, sometimes strand-like, poly(A) RNA signal was dispersed throughout the nucleoplasm. Spliceosome assembly factor SC-35 localized within the center of individual domains. These data support a nuclear model in which there is a specific topological arrangement of noncontiguous centers involved in precursor messenger RNA metabolism, from which RNA transport toward the nuclear envelope radiates.

Variations in bracket placement in the preadjusted orthodontic appliance

This study was conducted to determine the accuracy of bracket placement with the direct bonded technique. Ten orthodontic faculty members bonded a preadjusted orthodontic appliance on models of five cases of malocclusion in a simulated clinical situation (mannequin). A total of 50 sets of models served as the population of the study. Photographs of the models were measured to determine vertical and angular discrepancies in position between adjacent bracket pairs from a constructed reference line. Variations are evaluated with respect to the classification of malocclusion, specific tooth type, and intra/inter operator differences. A mean of 0.34 mm for the vertical discrepancies and a mean of 5.54 degrees for the angular discrepancies are found in placement of the orthodontic brackets.

The influence of extraction and nonextraction orthodontic treatment on brachyfacial and dolichofacial growth patterns

The effects of extraction and nonextraction orthodontic treatment mechanics on patients with dolichofacial and brachyfacial growth patterns between one and two standard deviations were studied. Groups underwent treatment of either nonextraction or extraction of four premolars with the appropriate mechanics for the facial type. Changes in the facial axis and correlation between maxillary molar movement and facial axis change were measured. A positive correlation was found between the amount of anteroposterior movement of the upper molar and change in the facial axis in brachyfacial and dolichofacial patients undergoing nonextraction treatment. A weak correlation was found in the extraction treatment groups. No statistically significant difference was found in the facial axis change among any of the groups studied, regardless of facial type or plan of treatment. There were indications of a more severe opening of the facial axis (Ba-Na plane to constructed gnathion) with greater degrees of maxillary molar distal movement in both facial patterns studied.

Effect of phenethyl isothiocyanate on the metabolism of tobacco-specific nitrosamines by cultured rat oral tissue

The effect of phenethyl isothiocyanate (PEITC) on the metabolism of N'-nitrosonornicotine (NNN) and 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) by cultured rat oral tissue was investigated. Two protocols were used. In one, oral tissue from untreated rats was cultured in the presence of 10 or 50 microM PEITC and either NNN or NNK. The levels of NNN and NNK metabolites released into the culture media were determined by HPLC analysis. The presence of 10 microM PEITC inhibited the formation of all NNN metabolites from 45 to 70% when the concentration of NNN was 1 microM or 10 microM. When the concentration of PEITC was 50 microM the extent of inhibition was from 70 to 90%. alpha-Hydroxylation of NNK was inhibited 70 to 90% and N-oxidation of NNK was inhibited 80 to 90% by 10 microM PEITC. Carbonyl reduction of NNK to NNAL was unaffected by 10 microM PEITC and only slightly inhibited by 50 microM PEITC. In the second protocol, rats were fed NIH-07 diet containing 3 mumol PEITC/g for 1-14 days. The metabolism of NNN by cultured oral tissue from these rats was decreased from 40 to 90% relative to that by tissue from control rats. NNK metabolism was inhibited 40 to 60%. The extent of inhibition was the same when rats were fed PEITC containing diet for 1 or 14 days. NNN and NNK are the only tobacco constituents which induce oral cavity cancer in an animal model. The results of this study suggest the possibility that PEITC may be useful as a chemopreventive agent for oral cavity cancer.

Iatrogenic transmission of Cytauxzoon felis from a Florida panther (Felix concolor coryi) to a domestic cat

A laboratory cat died 12 days after intraperitoneal inoculation of a 1 ml suspension containing 1.5 x 10(6) blood mononuclear cells from a Florida panther (Felis concolor coryi). Gross, histologic and ultrastructural investigations revealed the cause of death to be infection by Cytauxzoon felis, a protozoal parasite known to cause a rapidly fatal disease (cytauxzoonosis) in domestic cats. The bobcat (Felis rufus) has been identified as a natural host for C. felis. This report implicates the Florida panther as another possible host for C. felis.

Establishment and characterization of SV40 T-antigen immortalized human esophageal epithelial cells

Normal human esophageal autopsy tissue was explanted in serum-free medium. The epithelial outgrowths were subcultured and then transfected by strontium phosphate coprecipitation with plasmid pRSV-T consisting of the RSV-LTR promoter and the sequence encoding the simian virus 40 large T-antigen. The transfected cells, but not the sham-transfected controls, formed multilayered colonies within 3-4 weeks, after which the colonies were transferred and cell strains (HE-451 and HE-457) developed. Both cell strains grew exponentially for 8-10 weeks and then senesced. After a "crisis" of 6-8 months, growth resumed in isolated colonies. One line, HET-1A from HE-457, was developed and has now undergone more than 250 population doublings. This line has retained epithelial morphology, stains positively for cytokeratins and the simian virus 40 T-antigen gene by immunofluorescence, and has remained nontumorigenic in athymic, nude mice for more than 12 months. Karyotypic analysis by Giemsa banding has shown that HET-1A is hypodiploid (34-40 chromosomes). Growth factor studies have shown that HET-1A is stimulated by Ca2+, and inhibited by fetal bovine serum, transforming growth factor-beta 1, and transforming growth factor-beta 2. This serum-free immortalized esophageal cell system will be useful for investigating the action of putative esophageal carcinogens.

Two months of doxorubicin-cyclophosphamide with and without interval reinduction therapy compared with 6 months of cyclophosphamide, methotrexate, and fluorouracil in positive-node breast cancer patients with tamoxifen-nonresponsive tumors: results from the National Surgical Adjuvant Breast and Bowel Project B-15

The National Surgical Adjuvant Breast and Bowel Project (NSABP) implemented protocol B-15 to compare 2 months of Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH) and cyclophosphamide (AC) with 6 months of conventional cyclophosphamide, methotrexate, and fluorouracil (CMF) in patients with breast cancer nonresponsive to tamoxifen (TAM, T). A second aim was to determine whether AC followed in 6 months by intravenous (IV) CMF was more effective than AC without reinduction therapy. Through 3 years of follow-up, findings from 2,194 patients indicate no significant difference in disease-free survival (DFS, P = .5), distant disease-free survival (DDFS, P = .5) or survival (S, P = .8) among the three groups. Since the outcome from AC and CMF was almost identical, the issue arises concerning which regimen is more appropriate for the treatment of breast cancer patients. AC seems preferable since, following total mastectomy, AC was completed on day 63 versus day 154 for conventional CMF; patients visited health professionals three times as often for conventional CMF as for AC; women on AC received therapy on each of 4 days versus on each of 84 days for conventional CMF; and nausea-control medication was given for about 84 days to conventional CMF patients versus for about 12 days to patients on AC. The difference in the amount of alopecia between the two treatment groups was less than anticipated. While alopecia was almost universally observed following AC therapy, 71% of the CMF patients also had hair loss and, in 41%, the loss was greater than 50%. This study and NSABP B-16, which evaluates the worth of AC therapy in TAM-responsive patients, indicate the merit of 2 months of AC therapy for all positive-node breast cancer patients.

Postoperative chemotherapy and tamoxifen compared with tamoxifen alone in the treatment of positive-node breast cancer patients aged 50 years and older with tumors responsive to tamoxifen: results from the National Surgical Adjuvant Breast and Bowel Project B-16

The National Surgical Adjuvant Breast and Bowel Project (NSABP) conducted a randomized clinical trial to determine whether tamoxifen (TAM) plus chemotherapy is more effective than TAM alone in improving disease-free survival (DFS), distant disease-free survival (DDFS), and survival (S) of positive-node, TAM-responsive patients aged greater than or equal to 50 years. Women were randomized among three treatment groups: (1) TAM alone, (2) Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), cyclophosphamide, and TAM (ACT), or (3) melphalan (L-PAM), fluorouracil (5-FU), and TAM (PFT). The PFT arm was later modified so that new patients also received Adriamycin (PAFT). Findings from 1,124 eligible patients through 3 years of follow-up indicated a significantly better DFS for ACT-treated patients than for those receiving TAM alone (84% v 67%; P = .0004). An advantage in DDFS and S was also observed after ACT therapy (83% v 73% [P = .04 in the former] and 93% v 85% [P = .04 in the latter]). Both the DFS and DDFS of PAFT-treated patients were better than in those treated by TAM alone (83% v 66%, P = .0002 and 85% v 73%, P = .003). PFT patients also fared better in DFS and DDFS than TAM patients (81% v 72%, P = .07 and 85% v 74%, P = .02). Odds ratios consistently favored the three TAM-plus-chemotherapy groups. No significant S advantage is as yet evident in favor of the PAFT or PFT groups. Of importance is the failure of these studies to demonstrate an unfavorable interaction between the drug regimens used and the TAM, which was administered simultaneously. The findings related to the use of PAFT and PFT are of more biologic than clinical significance since L-PAM is rarely used in the treatment of breast cancer. The major conclusion from this study is the observance of a better outcome in positive-node breast cancer patients aged greater than or equal to 50 years from the use of postoperative prolonged TAM and short-course AC therapy (completed in 63 days) than from prolonged TAM therapy alone.

Systemic therapy in patients with node-negative breast cancer. A commentary based on two National Surgical Adjuvant Breast and Bowel Project (NSABP) clinical trials

OBJECTIVE

To determine whether in the previous National Surgical Adjuvant Breast and Bowel Project (NSABP) studies of node-negative breast cancer there were either cohorts of patients with a prognosis favorable enough to preclude using systemic therapy or subsets of patients who failed to benefit from the treatments.

DESIGN

Randomized clinical trials with stratification after surgery.

SETTING

NSABP trials at institutions in the United States and Canada.

PATIENTS

Data were collected on 731 eligible patients (Protocol B-13) with estrogen-receptor-negative tumors who randomly received either no therapy after surgery or sequential methotrexate and fluorouracil (M----F) followed by leucovorin. Data were also collected on 2834 patients (Protocol B-14) with estrogen-receptor-positive tumors who randomly received either placebo or tamoxifen treatment. The percentage of patients surviving disease-free was determined through 4 years of follow-up using life-table estimates.

INTERVENTIONS

Protocol B-13 patients received 12 courses of M----F given intravenously on days 1 and 8 every 4 weeks. Leucovorin therapy was begun 24 hours after M----F administration. Protocol B-14 patients received 5-year treatment with either tamoxifen (10 mg twice daily by mouth) or placebo.

RESULTS

When the outcome of untreated patients in either trial was related to the stratification variables, women were found to have a disease-free survival of less than 80% through 4 years of follow-up. This percentage is apt to decrease because the probability of treatment failure increases with time. In both trials, all subsets of women benefited from M----F or tamoxifen therapy.

CONCLUSIONS

The disease-free survival of all cohorts of node-negative patients with estrogen-receptor-negative or estrogen-receptor-positive tumors was poor enough to justify systemic treatment. The benefits of the therapies used are insufficient to eliminate the need for assessing putatively better regimens.

A cephalometric study of Korean adults

A cephalometric study of 18-year-old Korean subjects with acceptable profile and occlusion was carried out by means of the Downs, Steiner, Ricketts, and vertical analyses. The subjects in the study sample consisted of 35 men and 45 women. Means and standard deviations of the Korean subjects were established. Statistical analyses were performed to compare Koreans to Caucasians.

Doxorubicin-containing regimens for the treatment of stage II breast cancer: The National Surgical Adjuvant Breast and Bowel Project experience

Despite numerous reports of findings obtained following the use of doxorubicin (Adriamycin [A]; Adria Laboratories, Columbus, OH) for the postoperative treatment of patients with primary breast cancer and positive axillary nodes, no clear consensus exists regarding its worth when used in that setting. In June 1981, the National Surgical Adjuvant Breast and Bowel Project (NSABP) implemented two randomized clinical trials aimed at evaluating the worth of doxorubicin when administered in conjunction with melphalan (L-PAM) and fluorouracil (5-FU) (PF). A prior NSABP study identified cohorts of patients who did or did not benefit from tamoxifen (TAM, T) when used with chemotherapy. That information was employed in the design of the present studies. Women considered responsive to TAM (1,106) were randomized between PFT and PAFT, and those nonresponsive to TAM (707) were randomized between PF and PAF. Findings through 6 years of follow-up (mean duration of potential time on study, 64 months and 63 months, respectively) indicate that non-TAM-responsive patients who received PAF had a significantly better disease-free survival (DFS) (P = .003) and survival (P = .05) than did those receiving PF. By contrast, there was no significant difference in DFS (P = .6) or survival (P = .7) between PFT- and PAFT-treated patients. No disparity in the amount of drug received, whether related to the median amount or to dose-intensity, is present to account for the difference in findings between the studies. Aside from alopecia and emesis, the toxicity from the doxorubicin-containing regimens was similar to those in which doxorubicin was omitted. Cardiomyopathy was not a significant finding; there were no deaths from cardiac toxicity. The incidence of arterial and venous complications in patients receiving TAM was less than reported by others.

A randomized clinical trial evaluating sequential methotrexate and fluorouracil in the treatment of patients with node-negative breast cancer who have estrogen-receptor-negative tumors

We evaluated the postoperative use of sequential methotrexate and fluorouracil followed by leucovorin in 679 patients with primary breast cancer, histologically negative axillary nodes, and estrogen-receptor-negative (less than 10 fmol) tumors. No survival advantage was observed with this therapy as compared with no postoperative therapy during four years of follow-up (87 percent vs. 86 percent; P = 0.8). However, there was a significant prolongation of disease-free survival among women who received this therapy as compared with those who did not (80 percent vs. 71 percent; P = 0.003). An advantage was observed in both the patients less than or equal to 49 years old and those greater than or equal to 50. At four years, treatment failure was reduced by 24 percent in the younger group and by 50 percent in the older group. The rates of both local and regional and distant metastases were decreased. These benefits, achieved without the use of an alkylating agent, were associated with tolerable side effects. Multivariate analysis testing for potential interactions failed to identify subgroups of patients who did not benefit from the therapy. These results, although promising, do not obviate the need for additional trials to evaluate potentially better regimens of therapy, but they do suggest that sequential methotrexate-fluorouracil should be used in the control arm in such studies. Their use is also justified for the treatment of patients who refuse to participate in clinical trials, provided the patients meet the eligibility criteria of the present study. Since women with tumors too small for conventional analysis of estrogen-receptor and progesterone-receptor concentrations were not included in this study, we do not recommend systemic treatment for them outside of a clinical trial.

A randomized clinical trial evaluating tamoxifen in the treatment of patients with node-negative breast cancer who have estrogen-receptor-positive tumors

We conducted a randomized, double-blind, placebo-controlled trial of postoperative therapy with tamoxifen (10 mg twice a day) in 2644 patients with breast cancer, histologically negative axillary nodes, and estrogen-receptor-positive (greater than or equal to 10 fmol) tumors. No survival advantage was observed during four years of follow-up (92 percent for placebo vs. 93 percent for tamoxifen; P = 0.3). There was a significant prolongation of disease-free survival among women treated with tamoxifen, as compared with those receiving placebo (83 percent vs. 77 percent; P less than 0.00001). This advantage was observed in both the patients less than or equal to 49 years old (P = 0.0005) and those greater than or equal to 50 (P = 0.0008), particularly in the former, among whom the rate of treatment failure was reduced by 44 percent. Multivariate analysis indicated that all subgroups of patients benefited. Tamoxifen significantly reduced the rate of treatment failure at local and distant sites, tumors in the opposite breast, and the incidence of tumor recurrence after lumpectomy and breast irradiation. The benefit was attained with a low incidence of clinically appreciable toxic effects. The magnitude of the improvement obtained does not preclude the need for future trials in which patients given tamoxifen could serve as the control group in an evaluation of potentially better therapies. Tamoxifen treatment is justified in patients who meet the eligibility criteria of the present study and who refuse to participate in those trials. Since patients with tumors too small for conventional analysis of estrogen-receptor and progesterone-receptor concentrations were not eligible for this study, no information is available to indicate that such patients should receive tamoxifen.

Fatal toxoplasmosis and enteroepithelial stages of Toxoplasma gondii in a Pallas cat (Felis manul)

Toxoplasma gondii was found in tissues of a six-year-old female Pallas cat (Felis manul) from the Milwaukee County Zoo. Toxoplasma gondii meronts (types D and E), gamonts, and oocysts were present in the epithelium of the small intestine. Numerous unsporulated oocysts were present in the intestinal lumen. The cat died of acute, overwhelming toxoplasmosis. Necrotic enteritis, multifocal necrotizing granulomatous hepatitis, and pneumonia were the prominent lesions.

Cecal volvulus: decompression and detorsion with a colonoscopically placed drainage tube

Cecal volvulus is an uncommon cause of intestinal obstruction. Operative management is the accepted form of treatment. We report a patient with cecal volvulus who was a poor surgical risk and was successfully treated by decompression and detorsion with the use of a decompression tube inserted through the colonoscope.

Adjuvant chemotherapy with and without tamoxifen in the treatment of primary breast cancer: 5-year results from the National Surgical Adjuvant Breast and Bowel Project Trial

In this National Surgical Adjuvant Breast and Bowel Project (NSABP) clinical trial, 1,891 women with primary operable breast cancer and positive axillary nodes were randomized between Jan, 1977 and May 1980 to receive L-phenylalanine mustard (L-PAM) and 5-fluorouracil (5-FU) either with or without tamoxifen (TAM)-PFT. This report presents life table probabilities, cumulative odds ratios, and P values for disease-free survival (DFS) and survival at yearly intervals through 5 years of observation (mean time on study, 72 months). When patients were examined overall without regard for any discriminant associated with outcome, ie, age, number of positive nodes, or tumor receptor status, there was a significant prolongation of DFS (P = .002), but not survival through the fifth postoperative year. The benefit was almost entirely restricted to those greater than or equal to 50 years with greater than or equal to 4 positive nodes. In that group there was a 66% greater chance of remaining disease free if PFT was received (P less than .001), and there was also a significant survival benefit (P = .02). The advantage from PFT was found to be associated with tumor estrogen receptor (ER) and progesterone receptor (PR) as well as patient age and nodal status. Overall there was a significant improvement in DFS from PFT in those having tumors with an ER or PR level greater than or equal to 10 femtomole (fmol) (P = .01 and .009, respectively). No significant benefit in DFS or survival has been observed in patients less than or equal to 49 years old related either to nodes or tumor receptor status. Survival continues to be adversely affected by TAM in those patients (less than or equal to 49 years old), particularly when their tumors have a PR of 0 to 9 fmol (P = .007). In patients greater than or equal to 50 years old with four or more positive nodes, a significant DFS benefit persisted through the fifth year of observation in those having tumor ER or PR levels greater than 10 fmol (P less than .001 and .002). The advantage was observed in patients 50 to 59 years old as well as those 60 to 70. Women in the older decade demonstrated some advantage from PFT when their tumor ER or PR was 0 to 9 fmol. The most likely explanation for this finding is analytical error in receptor analyses.(ABSTRACT TRUNCATED AT 400 WORDS)

Forskolin: its effects on potassium-evoked release of vasopressin from the rat neurohypophysis

The effect of forskolin, added either before or 5 min after the onset of potassium-evoked release of vasopressin from isolated neurointermediate lobes of the rat has been investigated. A low concentration of forskolin (1 microM), added before stimulation, enhanced the potassium-evoked release of vasopressin throughout two successive 5 min periods of stimulation. Higher concentrations of forskolin (10-80 microM) produced no effect on the potassium-evoked release of hormone during the first 5 min of stimulation, but inhibited release during the second 5 min period. When added 5 min after the onset of potassium stimulation, forskolin (1-80 microM) reduced the amount of vasopressin released during the remaining 5 min of stimulation. Forskolin produced a concentration-dependent increase in cyclic AMP during both the control and potassium stimulation periods. The amount of cyclic AMP generated by forskolin during potassium stimulation was less than that produced during the corresponding control periods.

Forskolin inhibits potassium-evoked release of vasopressin from rat neurohypophyses

The effects of forskolin, an activator of adenylate cyclase, on the release of vasopressin from isolated rat neurointermediate lobes during a 10 min period of potassium stimulation were investigated. Forskolin was added 5 min after the onset of potassium stimulation. A concentration-dependent reduction in the amount of hormone released during the remaining 5 min period of stimulation was observed. The results suggest that an increase in cyclic AMP following depolarisation inhibits hormone release. This contrasts with several other reports showing that an increase in cyclic AMP prior to stimulation enhances release. We therefore propose that cyclic AMP plays a dual role in stimulus-secretion coupling in the neurohypophysis.

Force measurement and design of a torquing high-pull headgear

The dynamic extraoral force analyzer (DEFA) was found to be capable of measuring linear deflection as a function of force created by a headgear. Ten standard nontorqued face-bows with a cervical and a high-pull direction were tested to determine the reliability of the DEFA. Statistical analysis showed the DEFA to be reliable and accurate in differentiating various directions and deflections of maxillary molars. Doubled-over distal ends of the inner bow with 0 degree of torque and a parietal direction of pull were used as controls. The same face-bows with 9 degrees of buccal root torque were tested on the DEFA. These face-bows were tested to determine whether transverse translation without buccal crown tipping of the maxillary first molar will occur. Statistical analysis showed that transverse translation occurred at a force of 200 to 347 gm.

Relation of estrogen and/or progesterone receptor content of breast cancer to patient outcome following adjuvant chemotherapy

In 1977 the National Surgical Adjuvant Breast and Bowel Project (NSABP) initiated a prospectively randomized clinical trial to evaluate the relative merits of 1-phenylalanine mustard and 5-fluorouracil (PF) with and without tamoxifen (T) as adjuvant therapy for patients with primary breast cancer and positive axillary nodes. A previous presentation of findings noted that there was a strong relationship between the outcome of those receiving PFT and the estrogen receptor (ER) and progesterone receptor (PR) content of their tumors. This report relates the outcome of the PF-treated patients in that trial with these tumor receptors. It indicates that the results observed following nonhormonal therapy (PF) are also related to tumor receptors. Both the disease-free survival (DFS) and survival (S) of women following PF therapy were influenced by the ER and PR content of their tumors. Subsequent to adjustment for other prognostic variables, the predictive influence of tumor ER persisted. Both the DFS (p = 0.0003) and the S (p = 0.00003) were significantly higher in those with greater than or equal to 10 fmol tumor ER than in those with less than 10 fmol ER. The PR significantly added to the predictive value of ER. Thus, this analysis is the first to demonstrate that having information on both ER and PR is important for predicting outcome of patients receiving adjuvant chemotherapy. The study does not provide information which correlates receptor status with the response of patients to adjuvant chemotherapy since there is no similar nonchemotherapy-treated group of patients in the trial. The findings continue to emphasize that there is a heterogeneity in outcome of breast cancer patients to adjuvant chemotherapy which is related to an increasing number of host and tumor variables. For proper assessment of overall results, it is essential that analyses employ tests for interaction to indicate homogeneity or heterogeneity of patient subsets and that adjustments be made for imbalances in tumor ER and PR as well as in other prognostic factors.

Pharmacokinetics of vidarabine in the treatment of infants and children with infections due to herpesviruses

The pharmacokinetics of vidarabine were studied on 22 occasions in nine infants and three older children with herpesvirus infection. The drug was administered for 10 days in doses of 15-30 mg/kg per day. Vidarabine was not detected in the serum of any patient, although small quantities were detected in the urine of two of the older children. Peak serum concentrations of arabinosyl hypoxanthine, the major metabolite of vidarabine, ranged from 2.3 to 11.4 micrograms/ml. Concentrations of this metabolite were higher in two preterm infants than in full-term infants receiving comparable doses. The mean elimination half-life estimated from cumulative urinary excretion was 2.4 hr in a preterm infant, 3.1 hr in full-term infants, and 2.8 hr in older children. Neither clearance nor half-life changed when multiple doses were administered. Vidarabine and arabinosyl hypoxanthine did not accumulate during therapy. The rates of recovery of drug from the urine and of renal clearance of arabinosyl hypoxanthine were directly related to the age and maturity of the patient. Arabinosyl hypoxanthine readily diffused into cerebrospinal fluid.

Purification and characterization of posterior pituitary calmodulin and its activation of neurosecretosome Ca2+ + Mg2+-ATPase activities

Calmodulin was isolated as an electrophoretically homogeneous protein from bovine posterior pituitary glands. The yield indicated that this gland is a particularly rich source. Purified bovine posterior pituitary calmodulin and bovine brain calmodulin had identical electrophoretic mobilities on 10% and 12% polyacrylamide gels. The protein was further identified by molecular weight determination and by amino acid analysis which showed that it contained trimethyllysine, one residue per molecule. Bovine posterior pituitary calmodulin was found to activate a preparation of calmodulin-deficient phosphodiesterase from bovine heart. In addition, pituitary calmodulin stimulated Ca+ + Mg2+-ATPase activity associated with a purified nerve ending plasma membrane fraction. This dependence could only be demonstrated after successive washing of the membranes with EGTA buffers, a procedure designed to remove endogenous calmodulin.

Sequential methotrexate and 5-FU in the treatment of colorectal cancer

Administration of methotrexate (MTX), 5-FU, and leucovorin rescue in 29 patients with metastatic colorectal cancer produced an objective response rate of 41.7%, with two complete remissions. Two patients developed fatal toxic effects and three others had severe toxic effects. This trial, however, supports the evidence for the synergistic effect of this drug combination.

An analysis of the human genetics content of 13 general biology textbooks

Professionals in genetics, medicine, and biology education have in recent years called for placing greater emphasis on human genetics in the education of the nation's citizenry. Since a large collegiate audience for such education is found in the general biology classroom, we elected to analyze 13 current and widely used general biology textbooks to determine their human genetics content. The analyses revealed that from 6.68 to 15.51 percent of the books' pages were devoted to genetics, but only 0.75 to 3.44 percent of the pages dealt specifically with human genetics. The number of human genetic traits discussed in the books ranged from four to 24, with a mean of 15.77. Nine different chromosome aberrations were cited, with Down, Klinefelter, and Turner syndromes being mentioned most often. Twenty autosomal dominant, fifteen autosomal recessive, and seven X-linked traits were used as examples in the various textbooks. Most frequently cited single-gene conditions were the ABO blood groups, sickle cell anemia, phenylketonuria, hemophilia, and red/green colorblindness. The books varied considerably in the emphasis given to social applications of medical genetics. Based on the findings of this study, we offer several recommendations for the improvement of the human genetics content of general biology textbooks and courses.

Physiologic observations in a controlled clinical trial of the antiemetic effectiveness of 5, 10, and 15 mg of delta 9-tetrahydrocannabinol in cancer chemotherapy. Ophthalmologic implications

One hundred twenty patients about to receive their first treatment with potentially nauseant cancer chemotherapy were randomized to one of six antiemetic treatments: (1) no treatment; (2) placebo; (3) prochlorperazine (PCPZ), 10 mg; (4) delta 9-tetrahydrocannabinol (THC), 5 mg; (5) THC, 10 mg; (6) THC, 15 mg. Four doses of each medication were given orally at 4-hour intervals starting 2 hours before chemotherapy. A study nurse was responsible for both objective (nurse) and subjective (patient) symptom questionnaires. Serum levels were obtained at intervals for cross-reacting cannabinoids. Physiologic measurements including intraocular pressure (IOP), blood pressure, and pulmonary function were also recorded. In summary, the patients were remarkably free of adverse physiologic effects. All intraocular pressures before and after treatment were within the normal range, although a surprising statistically significant increase in IOP occurred in the group receiving 5 mg THC.

Treatment of primary breast cancer with chemotherapy and tamoxifen

We studied the possibility that the addition of tamoxifen to L-phenylalanine mustard combined with 5-fluorouracil enhances the benefit from the latter two drugs that has been observed in women with primary breast cancer and positive axillary nodes. Recurrence of disease was reduced at two years in patients given the three-drug regimen whose tumor estrogen-receptor levels were greater than or equal to 10 fmol. Among patients greater than or equal to 50 years old treatment failure was significantly reduced (P less than 0.001): by 51 per cent in those with one to three positive nodes and by 64 per cent in those with four or more. Higher receptor levels were associated with a greater probability of disease-free survival. Patients less than or equal to 49 years old were less responsive: those with one to three positive nodes received no benefit from tamoxifen at any receptor level, whereas those with four or more appeared to have reduced treatment failure associated with higher receptor levels. This adjuvant chemotherapy is not indicated in patients less than or equal to 49 years old whose tumor receptor levels are below 10 fmol; there is a suggestion of benefit in patients greater than or equal to 50 years old whose levels are low.

Bond strength of three orthodontic adhesives

A method was devised to study the bond strength of direct-bonding orthodontic adhesives. A shear load was applied parallel to the tooth-adhesive-bracket interface by means of an Instron Universal Testing Machine. The bond strength was found to increase for some products after 27 days. However, no significant differences could be detected 1 day after placement. The interface was studied to determine the mode of failure. In all cases bond failure occurred as mixed adhesive-cohesive phenomena.