The role of radiotherapy in the management of operable locally advanced breast carcinoma: results of a randomized trial by the Eastern Cooperative Oncology Group

BACKGROUND

The purpose of this study was to test the role of radiotherapy following total mastectomy, axillary dissection, and adjuvant systemic therapy in the management of operable locally advanced breast carcinoma.

METHODS

After undergoing mastectomy and axillary dissection, 426 patients with locally advanced breast carcinoma were registered on study and stratified by patient characteristics and risk factors. All patients were then treated with six courses of chemohormonotherapy. After being restaged, the 332 patients remaining without recurrence were randomized to receive prophylactic radiotherapy or to undergo observation and receive radiotherapy only if and when there was locoregional recurrence.

RESULTS

Three hundred twelve of 332 randomized patients were deemed eligible and analyzed for both time to relapse and survival. The median follow-up period was 9.1 years. There were no significant differences in time to relapse and overall survival between the two treatment arms. Of those assigned to radiation, 60% relapsed, with a median time to relapse of 4.7 years, and 46% were alive at last follow-up, with a median survival of 8.3 years. Of those assigned to observation, 56% relapsed, with a median time to relapse of 5.2 years, and 47% were alive at last follow-up, with a median survival of 8.1 years. The two treatment arms had significantly different patterns of sites of first recurrence. There were 9% fewer locoregional first recurrences among those assigned to radiation than among those assigned to observation (15% vs. 24%), whereas there were 15% more first relapses at distant sites (50% vs. 35%) among those assigned to radiation (P = 0.003).

CONCLUSIONS

Radiotherapy for locally advanced breast carcinoma, following mastectomy, axillary dissection, and adjuvant systemic therapy, results in fewer locoregional but more distant recurrences at first relapse. No significant advantage was seen for consolidation radiotherapy over observation in terms of either time to relapse or survival, both of which were virtually identical in the two treatment arms. [See editorial counterpoint on pages 1061-6 and reply to counterpoint on pages 1067-8, this issue.]

Medical record validation of maternally reported birth characteristics and pregnancy-related events: a report from the Children's Cancer Group

Epidemiologic studies frequently obtain exposure information through subjects' self-report (personal interview or mailed questionnaire). The authors used data from a case-control study of infant leukemia, to assess the validity and reliability of maternally reported information on birth characteristics such as birth weight, reproductive history, and medical procedures. Cases were gathered from the Children's Cancer Group, a United States and Canadian cooperative clinical trails group with approximately 100 member and affiliate institutions, during 1983-1988. Telephone interviews were completed for 302 cases and 558 matched controls. Medical records of the index pregnancy were obtained for 287 cases and 467 controls. Correlations between medical charts and maternal interview were high for birth weight (r = 0.98, kappa = 0.9) and gestational age (r = 0.86, kappa = 0.6). Mean differences between the two sources were small, -10.5 g for birth weight and -0.36 weeks for gestational age. Reproductive history and medical procedures had high to moderate reliability. Problems after delivery and pregnancy complications generally had low validity and reliability. Little evidence of differential misclassification was found. Time between delivery and interview ranged from zero to 8 years and did not greatly affect reliability. This study suggests that validity and reliability of maternally reported pregnancy and delivery information may differ with the nature of the factor of interest, but is affected little by time from birth or case-control status.

Mobility Strategies and Career Outcomes: A Longitudinal Study of MBAs

This research examines the impact of work- and non-work-related mobility on salary, promotions, job satisfaction, and organizational commitment among 671 male and female managers over a 7-year period. Results indicated that those with frequent lateral moves had significant gain in salary increases compared to those who did not move. In addition, frequent lateral moves had a negative impact on work-related attitudes, specifically overall job satisfaction and organizational commitment. Implications of these findings for career strategies and future research are discussed.

Optimal positioning for cervical immobilization

STUDY OBJECTIVE

We hypothesized that optimal positioning of the head and neck to protect the spinal cord during cervical spine immobilization can be determined with reference to external landmarks. In this study we sought to determine the optimal position for cervical spine immobilization using magnetic resonance imaging (MRI) and to define this optimal position in a clinically reproducible fashion.

METHODS

Our subjects were 19 healthy adult volunteers (11 women, 8 men). In each, we positioned the head to produce various degrees of neck flexion and extension. This positioning was followed by quantitative MRI of the cervical spine.

RESULTS

The mean ratio of spinal canal and spinal cord cross-sectional areas was smallest at C6 but exceeded 2.0 at all levels from C2 to T1 (P < .05). At the C5 and C6 levels, the maximal area ratio was most consistently obtained with slight flexion (cervical-thoracic angle of 14 degrees) (P < .05). For a patient lying flat on a backboard, this corresponds to raising the occiput 2 cm. More extreme flexion or extension produced variable results.

CONCLUSION

In healthy adults, a slight degree of flexion equivalent to 2 cm of occiput elevation produces a favorable increase in spinal canal/spinal cord ration at levels C5 and C6, a region of frequent unstable spine injuries.

Relation of taurine transport and brain edema in rats with simple hyperammonemia or liver failure

Taurine (Tau), an amino acid that abounds in brain, has been implicated in inhibitory neuromodulation and osmoregulation, the latter function being manifested by Tau release along with osmotically obligated water in response to brain tissue edema. A previous study (Hilgier and Olson: J. Neurochem. 62:197-204, 1994) had shown that simple hyperammonemia (HA) induced in rats by daily administration of ammonium acetate resulted in a decrease of both tissue specific gravity indicative of edema and Tau content, in basal ganglia (BG) but not in cerebral cortex (CC). By contrast, rats with hepatic encephalopathy (HE) following administration of a hepatotoxin, thioacetamide, were characterized by CC edema and an increased Tau content in both BG and CC. In the present study, we tested the following parameters that may potentially have affected Tau distribution in the two models: a) spontaneous, and stimulated (hypoosmolarity-induced) release of loaded [3H] Tau in vitro from CC and BG slices; b) blood Tau content; and c) uptake of [14C] Tau in vivo from blood to brain corrected for [3H] water passage-the so-called brain uptake index (BUI). The two edema-affected structures: BG in the HA model and CC in the HE model, showed increased spontaneous Tau release. Edema-associated spontaneous release of Tau may favor inhibitory neurotransmission contributing to the pathomechanism of HA or HE. Stimulated release, reflecting the ability of the tissue to reduce water content, was decreased in the BG from HA rats, in agreement with the postulated role of Tau in osmoregulation. Stimulated release was unchanged in CC of HE rats. Neither spontaneous nor stimulated release of Tau were affected in CC of HA rats or in BG of HE rats. HE, but not HA, was associated with elevated blood content and increased BUI for TAU, which in combination, contributed to the increase of Tau content in CC. The latter phenomenon adds to the list of metabolic changes distinguishing simple HA from toxic liver damage, reemphasizing the crucial role of factors other than ammonia in the pathomechanism of HE.

Antimalarial effects of vinyl sulfone cysteine proteinase inhibitors

We evaluated the antimalarial effects of vinyl sulfone cysteine proteinase inhibitors. A number of vinyl sulfones strongly inhibited falcipain, a Plasmodium falciparum cysteine proteinase that is a critical hemoglobinase. In studies of cultured parasites, nanomolar concentrations of three vinyl sulfones inhibited parasite hemoglobin degradation, metabolic activity, and development. The antimalarial effects correlated with the inhibition of falcipain. Our results suggest that vinyl sulfones or related cysteine proteinase inhibitors may have promise as antimalarial agents.

Hyperosmotic exposure alters total taurine quantity and cellular transport in rat astrocyte cultures

Taurine content and cellular taurine transport were characterized in astrocytes from rat cerebral cortex after growth in isoosmotic or hyperosmotic culture conditions to investigate mechanisms of taurine accumulation during conditions of increased osmolality. Total taurine content of the culture dishes was significantly (P < 0.05) elevated after 8, 24, and 48 h of hyperosmotic exposure compared to cultures grown for the same period in isoosmotic (300 mOsm, control) conditions. Hyperosmotic medium elevated intracellular taurine (nmol/mg protein) levels by 29-108% over control cultures. Significant (P < 0.02) increases in carrier-mediated taurine uptake rates were observed in astrocytes exposed to 350, 400, and 450 mOsm culture medium for 24 h compared to control cultures at the same time point. The increase in uptake rate decreased to control values by 48 h in 450 mOsm treated cultures. The carrier-mediated transport binding constant for taurine uptake, Km, was not altered at any time after hyperosmotic treatment. Maximal velocity of uptake, V(max), increased by 70% and 36% after 24 h growth in 400 and 450 mOsm culture medium, respectively, compared to control cells at the same time. After 48 h of hyperosmotic exposure, V(max) returned to control values. The diffusional transport rate for taurine efflux, Kdiff, was not affected by hyperosmotic exposure at any time point. Taurine release rates were increased by over two-fold during the first 8 h of exposure to 450 mOsm medium compared with cells grown in control conditions. After 24 and 48 h hyperosmotic exposure, release rates decreased to 44-72% of the release from control cultures. These data indicate at least three mechanisms contribute to taurine accumulation in cultured cerebral astrocytes exposed to hyperosmotic conditions. These mechanisms are (i) an increased rate of taurine uptake from the extracellular space within 24 h, (ii) a decrease in net taurine efflux by 48 h, and (iii) an enhanced rate of taurine synthesis.

Hypoosmotic volume regulation and osmolyte transport in astrocytes is blocked by an anion transport inhibitor, L-644,711

Cell volume, potassium content, and potassium influx were measured in rat cerebral astrocytes grown in primary culture following exposure to hypoosmotic medium containing either 3.2 mM or 50 mM potassium. Some solutions also contained 1 mM L-644,711, an anion transport inhibitor. L-644,711 inhibited volume regulation and taurine efflux induced by hypoosmotic exposure in medium containing either potassium concentration. L-644,711 also inhibited potassium uptake associated and not associated with the sodium/potassium pump. The correlation of reduced taurine efflux and volume decrease produced by L-644,711 exposure indicates the important role for this amino acid in hypoosmotic astrocyte volume regulation. However, the effects of L-644,711 on potassium transport indicate that multiple actions of this drug may be important factors in its effect on astrocyte volume regulatory mechanisms.

Eleven years' experience with pericardial-peritoneal window in the management of malignant and benign pericardial effusions

BACKGROUND

Before 1983 we routinely used subxiphoid drainage for the management of pericardial effusions. Pericardial-pleural window through a left anterior thoracotomy was used in selected patients. Due to frustration over the rate of recurrent pericardial effusions with subxiphoid drainage alone and concern over the higher morbidity with thoracotomy, the creation of a 3-cm pericardial-peritoneal window in the fused portion of the pericardium and diaphragm overlying the left lobe of the liver was added to subxiphoid drainage in 1983.

METHODS

This study is a retrospective chart review of the 33 patients undergoing pericardial-peritoneal window from 1983 through 1993. Eighteen patients had malignancies, mainly lung and breast, and 15 had benign pericardial effusions.

RESULTS

The procedure was well tolerated, with a 30-day mortality of 9%; however, no deaths were directly related to the pericardial effusion or the procedure. No patient developed peritoneal carcinomatosis or diaphragmatic hernia. One patient developed recurrent pericardial effusion during follow-up, and two required pericardiectomy for constrictive disease. Among those with malignancies, patients with breast cancer had the longest survival after pericardial-peritoneal window.

CONCLUSIONS

Pericardial-peritoneal window is a simple, safe, and effective procedure and applicable to most patients with malignant and noninfectious benign pericardial effusion, including those with tamponade.

Hypoosmotic volume regulation of astrocytes in elevated extracellular potassium

Cellular volume and potassium contents were determined in rat astrocytes from primary culture following suspension in isoosmotic (269 mOsm) and hypoosmotic (136 mOsm) phosphate-buffered saline (PBS) containing various potassium concentrations. Within 1 min of suspension in hypoosmotic PBS, cells swelled to 135% of their volume in isoosmotic PBS. This initial swelling was not altered by varying the potassium concentration of the hypoosmotic PBS. After suspension in hypoosmotic PBS containing 3.2 mM potassium, a regulatory volume decrease (RVD) was observed. Higher concentrations of potassium in hypoosmotic PBS inhibited RVD following osmotic swelling. Cells swollen in hypoosmotic PBS containing 50 mM potassium continued to swell for 7 min, reaching a volume of 141% of their initial isoosmotic volume. After 7 min, these cells demonstrated a subsequent decrease in volume. The swelling observed between 1-7 min after suspension in hypoosmotic PBS containing 50 mM potassium was not affected by 10 microM gadolinium, 1 mM quinine, 1 mM DIDS (4,4'-diisothiocyanato-2,2'-stilbenedisulfonic acid), 1 mM SITS (4-acetamido-4'-isothiocyanato-2,2'-stilbenedisulfonic acid), 1 mM furosemide, or 100 microM bumetanide. Normal RVD was obtained in hypoosmotic PBS containing 50 mM potassium, if chloride was replaced with gluconate (but not nitrate) to reduce the extracellular K.Cl product to that of hypoosmotic PBS containing 3.2 mM potassium. The volume decrease seen between 7-30 min after exposure to hypoosmotic PBS containing 50 mM potassium was blocked by 1 mM DIDS, 1 mM SITS, or 1 mM furosemide. Cellular potassium content was elevated by approximately 60% after 7 min exposure to isoosmotic or hypoosmotic PBS containing 50 mM potassium. In hypoosmotic PBS, this increase in cellular potassium was reduced with replacement of chloride by gluconate, but not by nitrate. The results indicate that astrocytes swollen in PBS containing elevated potassium concentrations continue to swell, in part, by accumulation of potassium plus chloride mediated by an approach to Donnan equilibrium. Cotransport carriers or stretch-activated channels do not play a role in the enhanced swelling observed in hypoosmotic PBS containing 50 mM potassium. We suggest that a voltage-sensitive chloride channel mediates this continuation of cell swelling. This mechanism may be important in the persistent swelling of astrocytes observed in pathologic conditions such as trauma and seizures where extracellular potassium is elevated, or when other factors are present which may cause astroglial depolarization.

Brain osmolyte content and blood-brain barrier water permeability surface area product in osmotic edema

Brain edema was induced in adult rats by intraperitoneal injection of distilled water equivalent to 15% of the animal's body weight. Mean +/- SEM serum osmolality fell from 291 +/- 3 mOsm to 253 +/- 4 mOsm during the next hour while cerebral gray matter water content increased from 79.5 +/- 0.2% to 80.9 +/- 0.2%. Gray matter content of sodium, potassium, taurine, glycine, glutamine, and glutamate were unchanged. However, the blood-brain barrier permeability/surface area product for water decreased by 40%. This alteration in water permeability may represent a response to limit water influx during the first hour of hypoosmotic brain edema.

Brain ion and amino acid contents during edema development in hepatic encephalopathy

Brain edema in hepatic encephalopathy has been associated with circulating ammonia that is metabolized to glutamine. We measured alterations in blood chemistry and brain regional specific gravity and ion and amino acid contents in models of simple hyperammonemia and liver failure induced by daily administrations of ammonium acetate (AAc) or thioacetamide (TAA), respectively. Serum and brain ammonia increased to similar levels (200 and 170% of control, respectively) in both experimental groups. Serum transaminase activities increased 10-fold in animals injected with TAA but were unchanged in animals given AAc injections. In both experimental groups glutamine was elevated in cerebral white matter, cerebral gray matter, and basal ganglia, whereas brain tissue specific gravity decreased in all brain regions, indicating edema formation. In the AAc group, we observed a decrease in glutamate and taurine contents concomitant with the development of brain edema. In these animals, cerebral gray matter specific gravity and taurine contents returned to control levels 24 h after the third AAc injection. TAA-injected animals demonstrated similar decreases in brain tissue specific gravity, whereas glutamine, glutamate, and taurine contents were all elevated. During hepatic encephalopathy, ammonia-induced changes in brain amino acid content may contribute to brain edema development.

Taurine transport in rat astrocytes adapted to hyperosmotic conditions

[3H]Taurine uptake and release was characterized in astrocytes from rat cerebral cortex grown in normal and hyperosmotic culture conditions to investigate mechanisms of cell volume regulation and adaptation to states of altered osmolality. In high concentrations of taurine (1 mM), uptake was linear in both osmotic conditions for at least 30 min. The uptake rate in 1 mM taurine was not affected by exposure to hyperosmotic conditions. The mean +/- S.E.M. apparent binding constant for carrier-mediated taurine transport, Km, was not altered by hyperosmotic conditions (22.8 +/- 5.1 microM in iso-osmotic media, 21.3 +/- 11.9 microM in hyperosmotic media). However, maximal velocity of uptake, Vmax (mean +/- S.E.M.), of taurine was significantly lower in hyperosmotically treated astrocytes (0.175 +/- 0.035 nmol/mg protein.min) compared with the Vmax of iso-osmotically treated astrocytes (0.299 +/- 0.026 nmol/mg protein.min). The diffusional transport rate, Kdiff, was not affected by growth in hyperosmotic conditions (0.221 +/- 0.033 microliter/mg protein.min in iso-osmotic media, 0.295 +/- 0.043 microliter/mg protein.min in hyperosmotic media). Taurine release rate, expressed as a percent of the total cell content, was not affected by hyperosmotic exposure. However, astrocytes grown in hyperosmotic conditions contain nearly 60% more taurine than control cells. Thus, the absolute rate of taurine release (mean +/- S.E.M.) was significantly larger (P < 0.05) in hyperosmotic cells (0.1592 +/- 0.0082 nmol/mg protein.min) compared with control cells (0.0943 +/- 0.0096 nmol/mg protein.min). Quantitative analysis of these data indicate that maintenance of elevated taurine contents by cultured cerebral astrocytes exposed to hyperosmotic conditions is not due to alterations in rates of transport.

Cell cycle-dependent gene expression in V point-arrested BALB/c-3T3 cells

Density-arrested BALB/c-3T3 cells stimulated to proliferate in an amino acid-deficient medium arrest in mid-G1 at a point termed the V point. Cells released from V point arrest require 6 hr to traverse late G1 and enter S phase. As data presented here show that mRNA synthesis is needed for 2-3 hr after release of cells from the V point, after which inhibition of mRNA synthesis does not prevent entry into S phase, we used this mid-G1 arrest protocol to analyze gene expression in late G1. We found that although stimulation of cells in amino acid-deficient medium did not inhibit the induction of genes expressed in early G1, genes normally expressed in late G1 were expressed only after release from the V point. The expression of late G1 genes in cells released from the V point was temporally similar, in respect to G1 location, as was seen in stimulation of quiescent G0 cells. As this protocol effectively divides gene expression into early (pre-V point) and late (post-V point) categories, it should be useful in studies of growth factor-modulated events that regulate traverse of late G1 and commitment to DNA synthesis. In addition, we used c-myb antisense oligonucleotides to show that c-myb expression, which occurs in late G1, is required for BALB/c-3T3 fibroblasts to traverse late G1 and initiate DNA synthesis.

Astrocyte volume regulation and ATP and phosphocreatine concentrations after exposure to salicylate, ammonium, and fatty acids

Cellular volume regulation following swelling in hypo-osmotic phosphate-buffered saline (PBS) and ATP and phosphocreatine concentrations of cells incubated in iso-osmotic or hypo-osmotic PBS were measured in primary cultured rat cerebral astrocytes exposed for 30 min to NH4Cl, salicylate, hexanoate, octanoate, and/or dodecanoate. These compounds have been implicated in the pathogenesis of cerebral edema in Reye's Syndrome. NH4Cl (0.10 - 10 mM) had no effect on astrocyte volume regulation or ATP concentration. Salicylate significantly reduced ATP concentrations at 3.0 mM and 10 mM but had no effect on volume regulation. Hexanoate (10 mM and 30 mM) decreased astrocyte ATP content by over 80% while octanoate (10 mM) reduced ATP content by more than 50%. Concentrations of these fatty acids at or below 3.0 mM had no effect on ATP content. Volume regulation was inhibited by 3.0 mM hexanoate and 3.0 mM octanoate but not lower concentrations. Dodecanoate (0.1-3.0 mM) decreased cellular ATP content by 33-51% in iso-osmotic PBS solutions. Phosphocreatine content was reduced by exposure to salicylate or octanoate at concentrations which had no effect on ATP content. These results indicate that astrocyte energy metabolism and volume regulation may be compromised by agents associated with cerebral edema in Reye's Syndrome. Analysis of the dose-dependence of these effects suggests that inhibition of astrocyte energy metabolism is not sufficient to affect volume regulation.

Family members of patients with sporadic medullary thyroid carcinoma must be screened for hereditary disease

BACKGROUND

Medullary thyroid carcinoma (MTC), a tumor arising from calcitonin-secreting C cells, appears in either a sporadic nonfamilial or a hereditary form as a component of a multiple endocrine neoplasia syndrome or familial non-multiple endocrine neoplasia MTC. Screening kindred of a patient with familial MTC to detect MTC in the early curable state is standard practice. Opinions conflict about whether it is necessary to screen relatives of patients with apparently nonfamilial MTC to exclude hereditary disease or whether the clinicopathologic features can differentiate between the two forms.

METHODS

Clinically well kindred of a patient with MTC that was histopathologically characteristic of the sporadic type were screened for hereditary disease by measurement of plasma levels of basal and stimulated calcitonin.

RESULTS

Three of four immediate relatives tested positive for excessive calcitonin secretion and underwent thyroidectomy. All had C-cell hyperplasia, the premalignant phase of MTC.

CONCLUSIONS

The patient with apparently sporadic (nonfamilial) MTC was clearly an index case of familial disease. We conclude that clinical presentation and histopathologic examination are not adequate to reliably exclude hereditary MTC. Until genetic markers are readily available to distinguish between sporadic and familial forms, biochemical screening should be done in primary relatives of all patients with newly detected MTC.

Objectives to direct the training of emergency medicine residents on off-service rotations: research

This is the 16th in a series of objectives to direct resident training in Emergency Medicine. Research is recognized as an important component of physician training, yet it is often neglected in medical school and residency curricula. We offer here an objective-based program for resident physicians' exposure to research design and methodology.

Correlations between energy metabolism, ion transport, and water content in astrocytes

Energy metabolism, ion transport, and water content are interrelated in mechanisms of homeostasis of the brain intracellular and extracellular environment. The simplest model of cell homeostasis, the pump-leak hypothesis, incorporates basic relationships between these variables. Although this model accurately calculates steady-state cell volumes, ion concentrations, and metabolic rates, it fails to predict dynamic changes in these properties during elevated extracellular potassium, metabolic inhibition, and osmotic swelling. We have investigated relationships between ions, energy metabolism, and water content in cerebral astrocytes cultured from the neonatal rat. These cells swell more in hypoosmotic phosphate-buffered saline (PBS) containing NaCl than in hypoosmotic PBS with all NaCl replaced equiosmotically by sucrose. Unidirectional Na+ influx also is greater in cells suspended in hypoosmotic, compared with isoosmotic PBS. These data suggest that astrocytes possess a cell volume dependent mechanism of Na+ accumulation. The influx of Na+ during swelling may be coupled to metabolism via Na-K ATPase and may contribute to the sustained swelling of astrocytes observed in hypoosmotic swelling of the brain in situ.

Rapid induction of competence formation is PDGF-isoform specific

Platelet-derived growth factor (PDGF) stimulates the expression of a number of genes associated with entry of quiescent Balb/c-3T3 fibroblasts into the cell cycle. We determined that two of these genes, c-myc and c-fos, are induced equivalently in medium supplemented with platelet-poor plasma (PPP) and either PDGF-BB or PDGF-AA. The rate at which fibroblasts entered S phase was also similar in PDGF-BB- and AA-treated cells as was the expression of the late G1 gene, thymidine kinase (TK). However, PDGF-AA must be present for a period of 16 h to stimulate the proliferation of 90% of the cells, whereas PDGF-BB was required for only 4 h. Exposure of cells to PDGF-AA for 4 h, a time during which maximum expression of c-fos and c-myc occurred, only induced 20% of the cells in a quiescent population to enter the cell cycle. Therefore, PDGF-AA-mediated expression of the immediate early genes c-fos and c-myc may be necessary but is not sufficient to rapidly stimulate density-arrested Balb/c-3T3 fibroblasts into the competent state. Thus, these data suggest that PDGF-AA and PDGF-BB initiate traverse of the cell cycle by distinct mechanisms.

Evaluation of acute brain edema using quantitative magnetic resonance imaging: effects of pretreatment with dexamethasone

We developed a quantitative magnetic resonance imaging method to permit a rapid assessment of brain water content during osmotic brain edema produced by intraperitoneal (ip) injection of distilled water. Fifteen minutes after water injection, the normalized mean image intensity (MIn) from a spin-echo pulse sequence (TE = 80 ms, TR = 1085 ms) was the same as that measured from control animals not injected with water. Sixty minutes after the water injection, the mean +/- SEM brain image MIn had increased by 10.8 +/- 2.4% compared to 3.4 +/- 0.7% in control animals (P less than 0.05). Blood plasma osmolality decreased by 6-10% during this time interval. A subsequent ip injection of hypertonic NaCl solution (100 gm/liter) caused the blood plasma osmolality and brain image MIn to return toward their initial values. MIn of cerebral gray matter correlated with tissue water content measured in parallel studies. Animals pretreated with 0.25 mg/(kg day) dexamethasone had cerebral gray matter MIn values during osmotic edema which were lower than those of untreated animals.

The effects of fructose-1,6-diphosphate on myocardial damage in acute coronary artery occlusion

Acute myocardial infarction can result from thrombosis of a coronary artery. The purpose of this study was to evaluate the ability of fructose-1,6-diphosphate (FDP; Esafosfina) to reduce myocardial necrosis during acute thrombosis of a coronary artery. A canine model of acute myocardial infarction was used to produce intraluminal thrombosis by placement of a coil of wire in a coronary artery. After developing a coronary thrombosis of the left anterior descending artery, dogs were injected intravenously with 90 mg/kg, 175 mg/kg, or 350 mg/kg of FDP or normal saline (controls). Hemodynamic, biochemical and electrocardiographic parameters were evaluated before, and 30 min and 4 h after occlusion. Four hours after acute coronary occlusion, the animals were sacrificed, and the weights of ischemic and necrotic myocardial tissue were quantified using a histologic-staining method. There were no significant differences between control and treated animals in biochemical or hemodynamic parameters. All animal groups treated with FDP demonstrated significant reductions in the amount of necrotic and ischemic tissue compared to controls (P less than 0.05). However, only the 175 mg/kg group had a significant reduction compared to controls in necrotic tissue weight as a percentage of ischemic myocardium (24 +/- 15% vs. 72 +/- 22%, respectively, P less than 0.01). These data suggest that FDP may have a role in limiting the amount of myocardial damage after an acute coronary artery occlusion.

The effect of tamoxifen on cervical squamous maturation in Papanicolaou stained cervical smears of post-menopausal women

Using cervical smears obtained as part of routine gynaecological examinations, a retrospective study of the effects of the drug tamoxifen on squamous epithelial maturation of the cervix of post-menopausal women being treated for advanced breast cancer was made. The degree of squamous epithelial maturation was quantitated by using the Maturation Index and the Maturation Value. Although tamoxifen is a synthetic, non-steroidal compound classified as anti-oestrogenic, the findings indicate that this drug commonly produces a level of squamous maturation indicative of oestrogenic stimulation in Papanicolaou stained cervical smears from post-menopausal patients receiving this drug. Knowledge of the oestrogenic effect of tamoxifen in the cervix can obviate clinical concern about endometrial carcinoma.

Brain water content, brain blood volume, blood chemistry, and pathology in a model of cerebral edema

STUDY OBJECTIVES

The objective was to correlate regional changes during brain water content with alterations in blood chemistry and cerebral pathology during hypo-osmotic edema.

PARTICIPANTS

Sprague-Dawley male adult rats were used in these studies.

DESIGN

Animals were block-randomized to receive either an intraperitoneal distilled water injection equivalent to 5% or 15% of their body weight or no injection (controls). Rats were sacrificed 15 or 60 minutes after water injection or at an equivalent time for controls.

INTERVENTIONS

No interventions were performed.

MEASUREMENTS AND MAIN RESULTS

Water content of cerebral cortical gray and white matter was calculated from measurements of tissue specific gravity. Blood plasma osmolality and sodium and potassium concentrations were determined at various times after water injection. An index of blood-brain barrier permeability was obtained by measuring brain red blood cell and plasma volumes. A qualitative assessment of edema was made from light and electron micrographs of the cerebral cortex. We found that water injection produced a dose-dependent decrease in plasma osmolality and sodium concentration within 15 minutes. Cortical water content was unchanged after this period. An influx of water into cerebral gray, and, less readily, into cerebral white matter occurred during the next 15 minutes. Whole blood specific gravity and brain blood content were unchanged and thus did not confound the measurement of cerebral water content. Hematocrit was increased 60 minutes after a 15% water injection. The blood-brain barrier remained intact throughout this period. Microscopy revealed astrocytic swelling with slight extracellular fluid accumulation 60 minutes after the water injection.

CONCLUSIONS

Homeostatic mechanisms in the cerebral cortex can maintain constant water content for at least 15 minutes during maintained intravascular hypo-osmolality. Fluid that subsequently moves into the tissue primarily enters an intracellular compartment. This model will be useful in investigating physiological mechanisms of brain water regulation and the pathogenesis of brain edema, a common clinical entity in emergency conditions.

Amino acid content of rat cerebral astrocytes adapted to hyperosmotic medium in vitro

Rat cerebral astrocytes from confluent primary cultures were grown for two weeks in medium made hyperosmotic with additional NaCl. At the time the cells were harvested (four weeks in culture), the medium osmolality of experimental cultures was approximately 600 mOsm. Amino acid, protein, and potassium contents and the cell volume were measured. Compared to cells maintained in control medium (approximately 300 mOsm), cells grown in hyperosmotic conditions had over two times the content of taurine and five times the content of glutamine. Alanine, aspartate, glutamate, glycine, and tyrosine contents also were elevated in these hyperosmotic-treated cells, while asparagine contents were unchanged relative to control cells. Cell volume and potassium content were decreased to approximately 50% of control levels by the hyperosmotic treatment while total protein content per cell was unchanged relative to cells from control cultures. Seven min after hyperosmotic-exposed cells were rapidly diluted into PBS with osmolality equal to about 330 mOsm, cell contents of alanine, asparagine, glutamine, glutamate, glycine, taurine, and tyrosine fell toward control levels. The data indicate that significant alterations in intracellular osmolytes occur in astrocytes adapted to hyperosmotic conditions. We suggest that a loss of intracellular potassium is at least partially compensated by accumulation of taurine, glutamine, and perhaps other amino acids acting as intracellular osmolytes.

Intracellular lipid droplets in functioning transitional parathyroid oxyphil adenomas. A caveat

Histochemical demonstration of intracellular lipid droplets on frozen section has been used to distinguish normal parathyroid tissue from that of adenoma and chief cell hyperplasia. Differentiation is based on the observation that the cells of adenoma and chief-cell hyperplasia largely lack intracellular lipid, which is present in the suppressed chief cells of normal glands in patients with adenoma. We present two functional transitional oxyphil adenomas that contained abundant intracellular lipid. Failure to recognize that transitional oxyphilic adenomas may contain focal accumulation of intracellular lipid droplets could lead to confusion in histologic interpretation.

Transmodulation of epidermal growth factor binding by platelet-derived growth factor and 12-O-tetradecanoylphorbol-13-acetate is not sodium-dependent in Balb/c/3T3 cells

The addition of platelet-derived growth factor (PDGF) to many types of cells causes a rapid decrease in high affinity binding of 125I-epidermal growth factor (EGF), a process which has been termed transmodulation. Treatment with the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA) also results in the transmodulation of the EGF receptor in many cell types. PDGF can transmodulate EGF binding through a mechanism that is not dependent on protein kinase C activity. A recent report (Wattenberg, E. V., McNeil, P. L., Fujiki, H., and Rosner, M. R. (1989) J. Biol. Chem. 264, 213-219) described the requirement for a sodium ion influx in the down-modulation of the EGF receptor stimulated by a non-TPA-type tumor promoter, palytoxin, in Swiss 3T3 cells. We tested for a similar sodium requirement in Balb/c/3T3 and Swiss 3T3 cells stimulated by PDGF or TPA in Balb cells treated with TPA for prolonged periods to down-regulate protein kinase C activity. Our results clearly show that the PDGF- and TPA-stimulated transmodulation of the EGF receptor does not require external sodium nor is the process affected by amiloride. In each of these experiments, the loss of 125I-EGF binding occurred to a similar extent and at a similar rate in the presence or absence of sodium. Intracellular pH also did not appear to have a role in the response. The sodium ionophore, monensin, was previously shown to bring about the down-modulation of 125I-EGF binding in Swiss cells. However, our results indicate that monensin-induced transmodulation of the EGF receptor occurs with or without external sodium, suggesting that the loss of binding is not the result of a sodium ion influx. These findings demonstrate that an increase in intracellular sodium does not cause nor is it required for PDGF- or TPA-stimulated EGF receptor transmodulation.

Control of astrocyte volume by intracellular and extracellular Ca2+

Astrocytes from primary culture were exposed to conditions that affect intracellular and extracellular Ca2+ concentrations. Astrocyte cell volume was increased approximately 16% after a 30 min exposure to isoosmotic phosphate-buffered saline (PBS) containing the Ca2+ buffer EDTA. Cell volume returned to control values within 30 min of resuspension in normal PBS. Cellular calcium content was not affected by these treatments; however, the recovery of normal cell volume following EDTA exposure was inhibited by 0.1-1.0 mM quinine HCl in a dose-dependent fashion suggesting that a potassium channel controlled by the intracellular Ca2+ concentration is important in this volume response. Intracellular accumulation of an exogenous Ca2+ buffer, BAPTA, also produced cell swelling that persisted following resuspension in normal PBS. Lowering the extracellular Ca2+ concentration with EDTA enhanced the swelling of BAPTA-loaded cells. These data suggest that conditions leading to a decrease in free intracellular Ca2+ concentration may influence astrocyte volume by a mechanism similar to that described in other cell types.

Plasma free thyroxine concentrations in patients receiving levothyroxine for thyroid suppression

The usual recommendation is to follow total triiodothyronine (T3) concentration during levothyroxine (L-thyroxine) therapy because 65% of clinically euthyroid patients receiving L-thyroxine have normal T3 but elevated total thyroxine (T4) levels. Because free thyroxine (FT4) is the metabolically active form of T4, our study was designed to determine whether FT4 by analog radioimmunoassay method is normal or increased in euthyroid patients receiving L-thyroxine. Twenty-seven clinically euthyroid patients, 5 males and 22 females, receiving L-thyroxine for thyroid suppression, were studied in a prospective protocol. Twenty-one euthyroid patients not receiving L-thyroxine served as controls. Samples were analyzed for T4, T3, T3 (RU), TSH, and FT4 by three analog methods. Mean FT4 levels were greater than control for all three assays. The percentage of patients with FT4 in the hyperthyroid range was 63% for assay I, 41% for assay II, and 52% for assay III. When patients were grouped by dose of L-thyroxine, FT4 levels were not significantly increased. Sixty-two percent of patients receiving L-thyroxine had T4 levels in the hyperthyroid range. T3 concentrations were not significantly greater in the L-thyroxine group when compared with control. In the L-thyroxine group, thyrotropin was significantly less than in the control group. FT4 concentration by analog method is in the hyperthyroid range in as many as 63% of clinically euthyroid patients receiving L-thyroxine. The use of FT4 to assess thyroid status may cause inappropriate adjustment of L-thyroxine dose. T3 level continues to parallel closely the physician's clinical impression and best represents peripheral metabolic status.

Six-year results of the Eastern Cooperative Oncology Group trial of observation versus CMFP versus CMFPT in postmenopausal patients with node-positive breast cancer

The Eastern Cooperative Oncology Group (ECOG) trial of adjuvant cyclophosphamide, methotrexate, fluorouracil, and prednisone (CMFP) or CMFP plus tamoxifen (CMFPT) for 1 year compared with observation alone in 265 postmenopausal patients with node-positive breast cancer is reported with 74 months median follow-up. Overall relapse-free survival tended to favor CMFPT (P = .08), but no survival differences existed between any treatment group. The addition of tamoxifen to CMFP led to slightly (but not significantly) better relapse-free status in all subgroups analyzed. Subgroup analysis based on stratification variables showed significant benefit from CMFP (+/- T) only in estrogen receptor (ER)-negative patients with respect to disease-free status (P = .0003), but not survival (P = .54). Relapse-free status was actually worse for CMFP-treated patients with ER-positive tumors, but not significantly so (P = .15). By multivariate analysis other significant risk factors for relapse-free status were primary tumor size, number of nodes pathologically involved, and the number of nodes examined. ER status was prognostic only for the observation group with the benefit from chemotherapy on ER-negative patients obliterating this difference in treated patients. Survival was affected by the number of involved nodes, tumor size, presence of tumor necrosis, and patient obesity. Analysis of toxicity showed elevation of liver enzymes during the first year to be more common in the observation group compared with those patients receiving adjuvant treatment and to be associated with early recurrence. Toxicity from adjuvant treatment persisted beyond termination of therapy in 53% of patients, but was usually mild and self-limited. We conclude CMFPT offers relapse-free survival benefit in ER-negative patients, but the value of chemotherapy in ER-positive postmenopausal, node-positive patients must be questioned.

Octanoic acid inhibits astrocyte volume control: implications for cerebral edema in Reye's syndrome

Octanoic acid has been implicated in the pathogenesis of cytotoxic cerebral edema in Reye's syndrome. Using astrocytes from primary culture, we studied the dose-dependent effects of octanoate on cellular volume regulation and metabolism. Astrocyte volume recovery following hypoosmotic swelling was stimulated by 1.0 mM octanoate and inhibited by 3.0 mM octanoate. Parallel effects were obtained at these concentrations on the activity of the Na+,K+-dependent ATPase. Cellular ATP concentrations also were reduced 36% with the higher octanoate concentration. These effects of octanoate may contribute to the severe astrocyte swelling observed in the brains of Reye's syndrome patients.

Cerebral oxygenation and blood flow in infant and young adult rats

In vitro cerebral oxidative metabolism undergoes dramatic increases in infant rats between 10 and 20 days of age. To determine this was also the case in vivo, comparisons were made of cerebral blood flow (CBF) and oxygenation in rats at 10, 20, and 60-90 days of age, under pentobarbital sodium anesthesia. Measurements were made of CBF, arterial and venous O2 content, cerebral PO2 distributions, and the oxidation state of cytochrome-c oxidase (cytochrome aa3). CBF, O2 delivery, and O2 consumption all increased progressively with maturation. In contrast, cerebral PO2, cytochrome aa3 oxidation state, and O2 extraction fraction were higher in 20-day-old rats than in either 10-day-old or adult rats. We attribute this difference primarily to the high density of cerebral capillaries in the 20-day-old rat. We conclude that cerebral tissue PO2 and the oxidation state of cytochrome aa3 are determined by the density of perfused capillaries in addition to the more commonly accepted factors of cerebral O2 delivery and consumption.

Intracellular acidification inhibits the proliferative response in BALB/c-3T3 cells

One of the earliest events to occur upon the addition of serum to quiescent cells is an increase in the intracellular pH (pHin). The relationship between this pH change and proliferation is not known. In the present study, we investigate the consequences of acidifying the cytosol using the weak acid, 5', 5"-dimethyl oxazolidine 2,4-dione (DMO). At a concentration of 50 mM, DMO inhibits the serum-induced increases in pHin, DNA synthesis, and cell number. This concentration of DMO is shown not to inhibit the steady-state rate of mitochondrial respiration and not to inhibit DNA synthesis in a pH-independent fashion. The effects of DMO treatments are also shown to be reversible, indicating that this compound is not cytotoxic. These observations indicate that DMO inhibits cell proliferation by lowering intracellular pH. One important event that must occur prior to the initiation of DNA synthesis is an elevated rate of protein synthesis. The rate of protein synthesis in situ is extremely pH sensitive. Addition of 50 mM DMO to serum-stimulated cultures reduces the rate of leucine incorporation to unstimulated levels. These observations suggest that cytoplasmic acidification may inhibit proliferation through its effects on protein synthesis.

Reduction of dye coupling in glial cultures by microinjection of antibodies against the liver gap junction polypeptide

Intracellular injection of antibodies to the 27-kDa liver gap junction polypeptide have been shown previously to uncouple pairs of cultured mammalian hepatocytes, cardiac myocytes, and ganglionic neurons (Proc. Natl. Acad. Sci. U.S.A., 82 (1985) 2412-2416). In confluent primary cultures of astrocytes, similar injections significantly reduced dye coupling for cells closer than 80 micron to the injected glial cell. Western blots identified a 27-kDa protein in extracts of the astrocyte cultures that cross-react with the gap junction-specific antibodies. These results suggest that homologous gap junction polypeptides exist in liver and glial cells.

Lead toxicity in primary cultured cerebral astrocytes and cerebellar granular neurons

Neurons are more sensitive than astrocytes to lead toxicity in vivo. In order to understand the bases for the differences in brain cell responses to lead, the effects of lead acetate on cell morphology and on aerobic energy metabolism were studied in rat primary cultured neurons and astrocytes. By transmission electron microscopy, neuronal cell damage was seen with exposure to lead concentrations which were much lower than those required for similar changes in the astrocyte. As previously described in our studies of in vivo lead exposure, astrocytes in primary culture concentrated lead in nuclear, cytoplasmic, and lysosomal inclusions while neurons showed lead densities only in lysosomes. With acute lead exposures, inhibition of maximal respiratory capacity was greater and occurred at lower lead concentrations in neurons than in astrocytes. Similarly, respiratory rates were inhibited at lower lead concentrations in cerebral cortical slices from 8-day-old rat pups compared to those from adults. We conclude that primary cultured brain cells are appropriate in vitro systems for studying the in vivo cellular responses to lead. As in vivo, neurons are more sensitive than astrocytes to lead toxicity. In both cells, inhibition of aerobic energy metabolism appears to be closely associated with cell damage. The capacity of the astrocyte to sequester lead in nonmitochondrial intracellular sites may be critical in resistance to lead toxicity in vitro and in the mature brain.

Brain cellular and mitochondrial respiration in media of altered pH

This study was designed to investigate the effects of altered pH on cellular aerobic energy metabolism in the immature and adult rat cerebral cortex. Cerebral cortical slice respiration was measured polarographically in acid and alkaline media. In separate experiments, the extracellular pH was changed by altering the HCO3- concentration or the intracellular pH and extracellular pH were changed by altering the CO2. Respiratory rates and oxidative phosphorylation in adult rat cerebral mitochondria also were measured in media with an altered pH. Increased intracellular pH inhibited respiratory rates in cortical slices from immature rats more than in tissue from adults. Decreasing the pH to 6.7 produced no changes in respiration in mature cortical slices and moderate inhibition of immature tissue respiration. In cerebral mitochondria, altered pH caused inhibition of State 3 respiration, respiratory control ratios, and ADP/O ratios. These changes were greater and occurred with smaller pH changes in the alkaline compared to the acid direction. From the results of these studies, we conclude that brain cellular respiration is not affected by moderate decreases in intracellular pH. With increased pH, there is inhibition of cellular and mitochondrial respiration, which may be the mechanism for the rise in lactic acid previously observed to result from hypocarbia in vivo.

Inflammatory pseudotumor of the spleen

Inflammatory pseudotumor of the spleen, an extremely rare benign inflammatory mass lesion, which clinically and radiologically mimics a neoplasm, is presented. The case is compared to the two cases previously reported in the literature. Possibilities of etiology and pathogenesis are considered.

Energy-dependent volume regulation in primary cultured cerebral astrocytes

Cell volume regulation and energy metabolism were studied in primary cultured cerebral astrocytes during exposure to media of altered osmolarity. Cells suspended in medium containing 1/2 the normal concentration of NaCl (hypoosmotic) swell immediately to a volume 40-50% larger than cells suspended in isoosmotic medium. The cell volume in hypoosmotic medium then decreases over 30 min to a volume approximately 25% larger than cells in isoosmotic medium. In hyperosmotic medium (containing twice the normal concentration of NaCl), astrocytes shrink by 29%. Little volume change occurs following this initial shrinkage. Cells resuspended in isoosmotic medium after a 30 min incubation in hypoosmotic medium shrink immediately to a volume 10% less than the volume of cells incubated continuously in isoosmotic medium. Thus, the regulatory volume decrease (RVD) in hypoosmotic medium involves a net reduction of intracellular osmoles. The RVD is partially blocked by inhibitors of mitochondrial electron transport but is unaffected by an inhibitor of glycolysis or by an uncoupler of oxidative phosphorylation. Inhibition of RVD by these metabolic agents is correlated with decreased cellular ATP levels. Ouabain, added immediately after hypoosmotic induced swelling, completely inhibits RVD, but does not alter cell volume if added after RVD has taken place. Ouabain also inhibits cell respiration 27% more in hypoosmotic medium than in isoosmotic medium indicating that the (Na,K)-ATPase-coupled ion pump is more active in the hypoosmotic medium. These data suggest that the cell volume response of astrocytes in hypoosmotic medium involves the net movement of osmoles by a mechanism dependent on cellular energy and tightly coupled to the (Na,K)-ATPase ion pump. This process may be important in the energy-dependent osmoregulation in the brain, a critical role attributed to the astrocyte in vivo.

Single sinusoids compared with a multiple-sinusoids technique for evaluating horizontal semicircular canal function

The vestibulo-ocular reflex (VOR) of 162 normal subjects was evaluated using two rotational testing procedures. Data from 79 subjects were collected using a set of five single-frequency stimuli (0.01 to 0.16 Hz) and 83 subjects were tested using multifrequency stimuli (0.01 to 0.27 Hz). The use of multifrequency stimuli in place of single frequencies reduced testing time from 75 min to 20 min per subject. The diagnostically useful phase response of the VOR, as estimated by the two tests, were not statistically different. Equivalent phase measures may be obtained within a shorter testing period using the multifrequency procedure.

A mastectomy--how so? An etymologic plea

The word mastectomy and its modifiers are used so loosely and have so many meanings in the literature that it is often difficult to determine precisely what procedure the authors are discussing. Simple descriptive terms should be used that would standardize the terminology with respect to operative techniques. The classical term radical mastectomy should be reserved to refer to a complete en bloc resection of the breast with the pectoralis major and minor muscles and the entire axillary contents, with or without a skin graft for wound closure. A total mastectomy should indicate a complete resection of the breast, including the fascia of the pectoralis major muscle. A local excision should be defined as a resection of the primary tumor with margins that are free of disease, with specific margins stated if desired. The axillary lymph node dissection should be defined according to the extent of the axillary contents excised.

Hyperthermia-induced seizures in rat pups with preexisting ischemic brain injury

To investigate the mechanism(s) relating perinatal brain injury to increased seizure sensitivity in the developmental age period, we studied hyperthermia-induced seizures in rat pups with a preexisting unilateral ischemic cerebral injury. At 2 days of age, the pups underwent a carotid artery ligation followed by 20 min of anoxia. By light microscopy, there were no pathologic changes in the postischemic cerebral cortex at 5, 10, or 20 days of age. Seizures were induced by hyperthermia at 5, 10, 15, or 20 days of age. Seizure temperature thresholds increased with maturation in both postischemic and control animals. Temperature thresholds for behavioral seizures were significantly lower at 10, 15, and 20 days in postischemic pups, compared with control animals. By EEG criteria, seizure thresholds also were lower at 10 and 15 days in the postischemic pups compared with control animals. Preictal EEG slowing appeared at the same temperature in experimental and control animals at all ages. We conclude that the rat pup is an appropriate model for the study of enhanced epileptogenesis in the presence of a perinatal ischemic encephalopathy.

Management of bleeding angiodysplasia of the upper small intestine

Five patients thought to have bleeding angiodysplasia in the distal duodenum and proximal jejunum were treated surgically after conservative measures failed to control hemorrhage. Aspiration through a long oral tube preoperatively and intraoperative endoscopy were most helpful in locating the site of bleeding.

Adjuvant CMFP versus CMFP plus tamoxifen versus observation alone in postmenopausal, node-positive breast cancer patients: three-year results of an Eastern Cooperative Oncology Group study

After mastectomy, 265 postmenopausal patients with node-positive breast cancer were stratified according to pathologic nodal status and estrogen-receptor (ER) status and randomized to receive either 12 cycles of cyclophosphamide, methotrexate, 5-fluorouracil, and prednisone (CMFP), or CMFP plus tamoxifen (CMFPT), or observation alone. Patients entered the study between March 1978 and July 1981. Cox regression analysis indicated that, compared to observation alone, chemotherapy (CMFP and CMFPT groups combined) led to a significant reduction in relapses by the end of the first year of study in every examined prognostic subgroup. However, after the first year the relapse-free survival curves of all treatment groups tended to merge, so that by three years 52% of the observation group and 51% of the chemotherapy groups remained disease free. Chemotherapy continued to show a significantly superior relapse-free survival rate for three years only in the subgroup of patients with ER-negative tumors (the subgroup with the largest relapse-free survival advantage at one year). The addition of tamoxifen produced no benefit or harm in any prognostic subcategory examined. ER status was prognostically important for predicting early relapse only in those patients not receiving chemotherapy, due to the greater effectiveness of this chemotherapy to prevent early relapse in the ER-negative subgroup. Treatment has had no early effect on survival. As breast cancer continues to recur even after ten or more years, later relapse patterns may alter these results.