Effect of oral alcohol on left ventricular ejection fraction, volumes, and segmental wall motion in normals and in patients with recent myocardial infarction

A first-pass nuclear angiogram and a multiple-gated acquisition study were obtained in 10 normal physicians and in 10 patients with a 7-to-10 day old transmural myocardial infarction. After the scan the subjects drank 2 oz. of whiskey. After 60 minutes, the multiple-gated acquisition study was repeated. In the normal group the left ventricular ejection fraction was 68% before and 72% after alcohol. The left ventricular end-diastolic volume increased from 89 to 97 ml while the left ventricular end-systolic volume decreased from 29 to 27 ml. The stroke volume rose from 61 to 70 ml/beat (p less than 0.05). The cardiac output increased from 4.0 to 5.0 l/min (p less than 0.05). In the infarction group, the left ventricular ejection fraction was 58% before and 56% after alcohol administration. The left ventricular end-diastolic volume fell from 111 to 96 ml, while the left ventricular end-systolic volume declined from 50 to 44 ml. The stroke volume fell from 61 to 52 ml/beat, while the cardiac output fell from 4.5 to 3.8 l/min. In the left ventricular infarction zones, alcohol produced in 9 of the 10 cardiac patients a decline in the left ventricular regional ejection fraction. In the normal group, alcohol produced no significant changes in the regional ejection fraction. The normal and the postinfarction patients responded differently to alcohol.

The value of screening for autoantibodies in patients with non-specific symptoms

An autoantibody screen is often requested in patients with non-specific symptoms such as pyrexia of unknown origin. However, in a survey of 100 consecutive requests for this investigation in such patients only one patient was encountered in whom the investigation led to a positive diagnosis at an estimated cost of pound 2500. These requests accounted for 5% of the total workload. These observations reaffirm that this should remain a second line investigation and should be deferred until more likely diagnoses have been excluded.

Trial of relaxation in reducing coronary risk: four year follow up

On screening 192 men and women aged 35-64 were identified as having two or more of the following risk factors: blood pressure greater than or equal to 140/90 mm Hg, plasma cholesterol concentration greater than or equal to 6.3 mmol/l (243.6 mg/100 ml), and current smoking habit greater than or equal to 10 cigarettes a day. They were randomly allocated to a group for modification of behaviour or to serve as controls. Both groups were given health education leaflets containing advice to stop smoking, to reduce animal fats in the diet, and on the importance of reducing blood pressure. In addition, the treatment group had group sessions of one hour a week for eight weeks in which they were taught breathing exercises, relaxation, and meditation and about managing stress. It had previously been found that after eight weeks and eight months there was a significantly greater reduction in both systolic and diastolic blood pressures in the group taught to relax compared with the control group. After four years of follow up these differences in blood pressure were maintained. Plasma cholesterol concentration and the number of cigarettes smoked were lower in the treatment group at eight weeks and eight months but not at the four year follow up. At four years more subjects in the control group reported having had angina and treatment for hypertension and its complications. Incidence of ischaemic heart disease, fatal myocardial infarction, or electrocardiographic evidence of ischaemia was significantly greater in the control group. If the results of this study could be obtained in a larger study the financial and health care implications would be enormous.

The Osborn wave in hypothermia

A patient is reported who presented with fatal hypothermia. The electrocardiographic changes of a sinus bradycardia, prolonged QT interval and Osborn waves were documented and correlated with body temperature. The possible genesis of these electrocardiographic changes is reviewed in this article.

Immunology of inflammatory bowel disease

Although the aetiology of ulcerative colitis and Crohn's disease remain unknown, immunological effector mechanisms become activated within the inflamed mucosa and may be responsible for the pathogenesis of chronic disease. There is an increased production of immunoglobulin within the mucosa, some of which has specificity for bacterial antigens, and complement activation occurs during exacerbation of the disease. Lymphocytes isolated from peripheral blood, or from the intestinal mucosa, are cytotoxic to colonic epithelial cells in vitro; a reaction which can be modulated by serum factors and bacterial antigens. Within the mucosa, there are increased populations of T lymphocytes although there is no change in the ratio of helper- to suppressor-cells as defined by phenotype. Studies of immunoregulatory control have shown that there may be alterations in the modulation of the local immune response, especially during active disease, although it is not clear whether these changes are primary or merely secondary to inflammation. It is posulated that many of the humoral and cellular responses to gut-associated antigens occur as a result of increased antigen absorption, increased presentation of antigen to the immune system due to the expression of Class II antigens by the inflamed epithelium and altered immuno-regulatory control.

Infectious endocarditis caused by Actinobacillus actinomycetemcomitans

Actinobacillus actinomycetemcomitans is a very uncommon cause of infectious endocarditis. The organism was first described in 1912. Thjotta and Sydnes reported its isolation in pure culture from a long standing abscess which had developed after tooth extraction. Subsequently this organism was found to be part of the normal flora, and the organism was defined as a slow growing, fastidious gram negative bacillus. Carbon dioxide is essential for the growth of A. actinomycetemcomitans. Approximately 50 cases of endocarditis due to A. actinomycetemcomitans have been reported since the first case reported in 1964. The purpose of this report is to document a case of endocarditis due to A. actinomycetemcomitans and to stress the value of the echocardiogram in the assessment of patients with endocarditis.

Pharmacology of propranolol in patients with cirrhosis and portal hypertension

Ten patients with cirrhosis and protal hypertension received an initial 20 mg oral test dose of propranolol and subsequently 160 mg of a slow release preparation, orally, each day for seven days. Protein binding, serial plasma propranolol concentrations and effects on heart rate were studied. Protein binding was slightly reduced (mean 85%, range 78.9-88.1%) compared with four normals (mean 87.9%). In patients with severe liver disease (serum albumin less than 30 g/l) propranolol remained detectable in plasma 24 hours after the single 20 mg dose and high steady state concentrations (mean 266.5 ng/ml, range 84-406) were observed during regular dosing. At steady state there was a significant correlation between log total plasma propranolol concentrations and the percentage fall in heart rate (r = 0.659, p less than 0.05). We suggest that in patients with severe liver chronic disease (serum albumin less than 30 g/l), propranolol therapy should be initiated in hospital. The starting dose should be low (20 mg of the conventional formulation tds or 80 mg of the slow release preparation daily) and that regular monitoring of the heart rate should be carried out.

Value of radionuclide angiogram for the diagnosis of Ebstein's anomaly

A radionuclide angiogram in a patient with Ebstein's anomaly showed a very dilated right atrium with a minimally enlarged right ventricle and a normal sized left ventricle. This study led to the establishment of a definitive diagnosis by means of an echocardiogram. Late close of the tricuspid valve was demonstrated. In addition prolapse of the tricuspid and mitral valves was documented. A tricuspid valve prolapse has never been reported in this condition.

Upper gastrointestinal endoscopy in systemic vasculitis presenting as an acute abdomen

Three cases of upper gastrointestinal vasculitis presenting as acute abdominal emergencies highlight an uncommon but often fatal presentation of systemic vasculitis. Although abdominal symptoms are common in such diseases, there may be a doubt during assessment of the patient as to whether the gastrointestinal tract is the prime target organ. Radiology is often negative during the acute illness. Endoscopy was important in documenting early and more advanced bleeding lesions of polyarteritis nodosa (PAN) and Henoch-Schoenlein disease, both conditions in which upper gastrointestinal lesions are rare. The gastric and duodenal vasculitic lesions demonstrated by endoscopy in such a clinical setting were confirmed histologically. Endoscopic assessment and early aggressive medical therapy contributed significantly towards the overall successful outcome. Gastroduodenoscopy has not been used either routinely or as an emergency investigation for the assessment of patients with vasculitis who present with acute abdominal pain. Involvement of the stomach and duodenum by vasculitis is therefore poorly appreciated, but remains a serious complication of vasculitic disease when the gastrointestinal tract is the prime target organ, and the information gained by endoscopy in a difficult clinical situation might alter the overall outcome of the disease.

Nucleoli, micronucleoli, and nucleolus-like structures in human oocytes at meiotic prophase I studied by the silver-NOR technique

Meiotic nuclei preparations obtained from human fetal ovaries were studied with the silver-NOR technique. At leptotene, the NOR's were located at the periphery of the nucleoli. The mean number of NOR's per nucleus was 6.4. Moreover, 2-12 micronucleoli, each containing an Ag-positive zone, were observed. At pachytene, each nucleolus was divided into two zones, one of which was Ag-positive. The mean number of Ag-positive zones was 2.1 per nucleus. The subterminal region of the short arm of nucleolar bivalents was in contact with the argyrophilic nucleolar zone. In most cells, micronucleoli were dispersed between the bivalents. A single rounded body which stained heavily with silver was consistently observed. At early diplotene, the NOR's separated, appearing again as distinct rounded Ag-positive structures embedded in the peripheral part of the nucleoli. The silver-stained round body was still visible. Eight to twelve micronucleoli were observed. At a more advanced stage of diplotene, the number of micronucleoli increased, varying from 20 to 50 per nucleus. These observations suggest that the micronucleoli, already visible at the leptotene stage, are the morphological expression of an early transcription of amplified rDNA. The biological significance of the Ag-positive round body remains obscure, but the consistency of its appearance suggests that it has a specific function somehow related to nucleolar proteins.

Augmentation of flap survival by thymoxamine

An experimental study in rats showed that the use of the alpha-receptor antagonist, thymoxamine could increase the blood supply to an ischaemic flap. Thymoxamine has a very short half-life, must be given frequently to be effective, but has the significant advantage that its action can be reversed by noradrenaline. When a flap is in trouble, alpha-receptor blockade by thymoxamine might help dramatically in its salvage.

Improved stability of methanolic Wright's stain solution with dual additives

Degradation of methanolic Wright's stain solutions was greatly diminished with the addition of diethylamine hydrochloride and dimethylamine hydrochloride as costabilizers. Precipitation problems were eliminated by the dual additives. The stabilized stain solutions demonstrated good staining performance on blood smears. Methods for predicting the shelf life using calculated analytical parameters are described. Using these methods, the shelf life of a control stain solution was predicted to be 0.7 years; predicted shelf life was more than tripled with the addition of diethylamine hydrochloride and was increased approximately 27 times with the addition of both diethylamine hydrochloride and dimethylamine hydrochloride.

Improved stability of methanolic wright's stain with additive reagents

Additive reagents have been investigated to improve the stability of methanolic Wright's stain. The addition of ammonium halides, monoalkylamine hydrochlorides, dialkylamine hydrochlorides or trialkylamine hydrochlorides to methanolic Wright's stain was found to enhance the stability of stain components in methanol. No change in performance is observed with these additives present. Random precipitation in the stain solution was still observed with the addition of ammonium halides and monoalkylamine hydrochlorides. No precipitation was found in stain solutions containing hydrochlorides of most dialkylamines and trialkylamines. Of the compounds evaluated, 0.6% diethylamine hydrochloride added to methanolic stain solutions produced the most desirable overall results. Mechanisms of stabilization and precipitation in these stain solutions are proposed. Essentially, separation of the thiazine-eosinate ion pair through interaction with an appropriate additive increases stain stability. The solubilities of thiazine-eosinate or additive cation-eosinate ion pairs in methanol determine the formation of precipitate in such stain solutions.

Controlled trial of biofeedback-aided behavioural methods in reducing mild hypertension

Employees of a large industry were screened for the presence of coronary risk factors. A total of 204 employees, aged 35-64 years, with two or more such factors (serum cholesterol concentration greater than or equal to 6.3 mmol/l (243.6 mg/100 ml), blood pressure greater than or equal to 140/90 mm Hg, and current cigarette consumption greater than or equal to 10 cigarettes a day) were randomly allocated to a biofeedback group receiving training in relaxation and management of stress or a control group. Both groups received simple health education literature. After eight weeks of training, and again eight months later, the biofeedback group showed a significantly greater fall in systolic and diastolic blood pressures than the control group (p less than 0.001). Plasma renin activity and plasma aldosterone concentration were measured in a subsample at entry to the study and again at eight weeks and eight months; both showed a greater reduction in the biofeedback compared with the control group at eight weeks' follow-up. The greater reduction in blood pressure in the subjects in the biofeedback group compared with the control group (11.0 mm Hg systolic and 8.8 mm Hg diastolic), persisting eight months after the training, suggests that relaxation-based behavioural methods might be offered as a first-time treatment to patients with mild hypertension.

Routine cytodiagnosis of pulmonary malignancies

Anesthesiologists normally discard the material routinely suctioned from the tracheal tube of patients under general endotracheal anesthesia. We preserved, and later examined microscopically, specimens from 10,621 patients. We found 11 cytologically abnormal smears from subjects with unsuspected pulmonary involvement, an incidence slightly more than 1:1,000. The accuracy of our method was assessed by calculation of the percent of abnormal smears obtained from patients with prediagnosed bronchogenic carcinomas: 40% when suctioned material was immediately spread on slides, and 67% when cellular concentration was achieved by mucolysis followed by filtration or centrifugation. Secretions normally discarded can reveal much information that would otherwise be missed. Our method may be useful if applied to patients at risk (heavy smokers, workers with asbestos, nitrosamine, or benzopyrine, miners of radioactive material, etc) who undergo general anesthesia for incidental surgery.

A screening test for influenza immunity: preimmunization antibody titers to influenza virus antigens in atopic patients

Antibody titers to three common strains of influenza virus, including the Swine Flu strain, were determined in 152 patients in an allergy and pediatric allergy practice prior to planned immunization with influenza vaccine. Because allergic patients are considered to be more prone to hypersensitivity reactions than individuals who are non-allergic, it was deemed prudent to screen for patients who might have pre-existing protective levels of antibody to the viruses. A considerable number of the 152 patients were found to have titers of 1:20 or 1:40 to one or more of the three influenza strains, including the Swine Flu strain. The largest percentage of positive antibody levels was found to be to the A-Victoria strain which has recently been most prevalent in the northeastern United States. The lowest numbers of patients with protective antibody levels were for the Swine Flu strain. Nevertheless, the highest titers occurred with patient specimens tested against the Swine Flu strain. Approximately one-quarter of the patients showed significant levels of antibody (1:40 or more) to one or more of the virus antigens and thus were not vaccinated, avoiding the possibility of untoward areactions which habe been observed in some individuals who have been given the vaccine.

Effects of minute volume increases on the rebreathing characteristics of the Bain anaesthesia circuit during controlled ventilation

In the course of a study on the carbon dioxide rebreathing characteristics of the Bain anaesthesia circuit, it was noted that raising the minute volume without changing the fresh gas inflow invariably led to increased rebreathing of expired gases. Altering tidal volume and rate in order to reproduce a given minute volume had the same effect on rebreathing. A nomogram constructed to quantitate increases in rebreathing in function of carbon dioxide production per minute, fresh gas flow from the anaesthesia machine, and minute volume is produced. It can be used to assess the amount of fresh gas flow necessary to mantain a steady and inspired gas composition.

Muscular dystrophy in an X; 1 translocation female suggests that Duchenne locus is on X chromosome short arm

A unique combination of a Duchenne-like muscular dystrophy in a girl with a translocation-inversion rearrangement involving an X chromosome and a no 1 chromosome appeared as a result of both gene mutation and chromosome mutation in the mother. The X-autosome rearrangement would permit full expression of an X-linked recessive gene, such as that for Duchenne muscular dystrophy, in a female, and this would satisfactorily explain the characteristic Duchenne-like course of our patient's illness. The simultaneous de novo appearance of the Duchenne mutation and the X;1 rearrange suggests possible sites for the Duchenne locus on the X chromosome short arm (at Xp1106 or Xp2107).

Investigation of reaction intermediates of the urea-diacetylmonoxime reaction

1. An investigation of the intermediates of the urea-diacetylmonoxime reaction and the isolation of the protochromogen has been described. A comparative spectral study of the protochromogen with that of the literature values suggested the structure of the protochromogen to be a diureide. 2. The diureides of 1-phenyl-1,2-propanedione-monoxime and 2,3-pentanedione were synthesized and their visible, U.V., I.R., NMR, and mass desorption spectrometry data were analyzed. The study suggests that the structure of each of these compound is that of a diureide. When these diureides were redissolved in acid media, they gave the color expected of the corresponding chromogens found from the respective diketones and urea. 3. The 3a-methyl-6a-phenyl-glycoluril was synthesized by a base-catalyzed reaction. When this glycoluril was dissolved in concentrated HCl, a pink color was obtained, similar to that of the corresponding diureide. These studies indicate that both the diureide and the glycoluril (if formed at all in acid-catalyzed reaction) are converted to the same chromogen, possibly via a rearrangement. 4. When 2,3-butanedionemonoximethiosemicarbazone was reacted with urea in acid medium, characteristic spectral data were obtained which were very similar to those of the urea-diacetylmonoximethiosemicarbazide reaction. This tends to indicate that the possible structures of the protochromogens are similar and of the open chain diureide type.

Humidity and the anesthetized patient

Damage to the ciliated cells of the tracheobronchial tree and incidence of postoperative pulmonary complications were measured by point-scoring systems in 202 patients who breathed dry and humidified anesthetic gases for 225 +/- 78 min. The incidence of postoperative pulmonary complications decreased as the humidity of administered anesthetic gases increased from 0 to 32.5 mg H2O/l. A similar relationship was found between the amount of inhaled moisture and the damage to the ciliated epithelium of the tracheobronchial tree. These results appear to indicate that a high inspired humidity is beneficial for operations on normothermic patients, and that cellular damage caused by dryness is a possible contributory factor in the production of the pulmonary atelectasis that follows stoppage of the mucociliary transport system in the immmediate postoperative period.

Spin Probe Spin Labeled Studies of Heparins and Derivatives

The polyelectrolyte heparins have a multiplicity of activities in vivo and in vitro including interactions in the coagulation cascade. The stereochemical factors or functional groups specifically associated with these activities have not been clarified. In order to further study the structure-function relationships we used a probe technique, labeling the carboxyl groups of heparins, derivatives and chondroitins with ATEMPO. Electron spin resonance and biological activity studies of nitroxide labeled heparins, and derivatives reveal a small correlation time (Ic) indicating that the label has free rotation when complexed to the carboxyl group. The labeled compound retains 85% of its anticoagulant activity and the complex binds antithrombin III to the same extent as heparin. Nuclear magnetic resonance spectra of the derivatives indicate that the complexing agent, carbodiamide is differentially displaced by ATEMPO at some of the carboxyl groups. The technique permits study of the stereochemistry of the carboxyl groups present in the polysaccharide.

Disseminated Cryptococcus treated with transfer factor

Cardiac toxic reactions and pulmonary consolidation in the left lower lobe developed in a patient who was receiving amphotericin B therapy for cryptococcal meningitis. Following surgical resection of the lobe, multiple subcutaneous cryptococcal abscesses appeared. Flucytosine administered intravenously failed to eradicate the lesions. Transfer factor therapy and multiple drainage procedures elimniated the skin abscesses. Transfer factor therapy was administered for one year; the patient was asymptomatic 16 months after therapy was discontinued.

A high-humidity circle system for infants and children

A scaled-down version of a modified adult circle system capable of increasing normal humidity output 300% was constructed for pediatric use. The moisture content of the gases leaving the system was tested and found to be superior to that of any pediatric circle system commercially available that does not incorporate an electrically heated water vaporizer.

An infant circuit with a water vaporizer warmed by carbon dioxide neutralization

A pediatric anesthesia system was constructed by connecting the machine end of a modified Mapleson D system to a soda lime canister containing a water vaporizer heated through the reaction of neutralization of the lime by the CO2 emerging from the breathing tube. The vaporizer was placed in line with the fresh-gas delivery tube of the circuit. The humidity output of the system varied from 15 +/- 1 mg H2O/L with a CO2 output of 15 ml/L to 27 +/- 1.5 mg H2O/L with a CO2 output of 60 ml/min. Rebreathing of CO2 was within acceptable limits as long as fresh-gas inflow remained at 5 L/min. The system compares favorably in respect to its humidity output with all other circuits availabe on the market for pediatric anesthesia.

Cellular content of amniotic fluid as predictor of central nervous system malformations

Prospective observations on 442 consecutive samples have confirmed that pregnancies with CNS malformations are regularly associated with an abnormal cellular content of amniotic fluid. A crude semiquantitative test of the cell content can give valuable clinical information in relation to borderline amniotic fluid alpha-fetoprotein values, and help to detect false positive AFP's.

Comparative toxicity of polychlorinated biphenyl and polybrominated biphenyl in the rat liver: light and electron microscopic alterations after subacute dietary exposure

The comparative toxicity of polychlorinated biphenyl (PCB) and polybrominated biphenyl (PBB) in livers was studied in male Holtzman rats. Four-week-old animals were fed at dietary levels of 0, 5, 50, or 500 ppm for 5 weeks and then sacrificed. The mean liver-body weight ratios of the 50 and 500 ppm groups were increased. Histopathologic examination of the livers revealed fatty degenerative change associated with both compounds. This change was more marked at 500 than at 50 ppm. Various sized lamellar cytoplasmic inclusions were detected in livers of animals fed 500 ppm of either compound. However, the inclusions were more numerous in the PBB-treated rats. Several animals fed 50 ppm PBB had a few inclusions. In rats that received 500 ppm PBB, hypertrophic degenerative hepatocytes were present around the central veins. On the periphery of this change there were occasionally multinucleated hepatocytes. Electron microscopic examination at a dose level of 5 ppm in both the PCB and PBB groups showed a slight proliferation of smooth endoplasmic reticulum (SER), a moderate increase of lipid droplets and some liposomes, and a marked proliferation of Golgi condensing vesicles containing lipoprotein particles. A decreased number of mitochondria and lysosomes was also observed. At 50 ppm, similar but more marked ultrastructural alterations were seen. In addition, an increased number of branched and cup-shaped profiles of mitochondria and a decreased number of Golgi condensing vesicles containing lipoprotein particles were observed. Concentric membranous cytoplasmic whorls were encountered only in the 50 ppm PBB-treated rats. At 500 ppm the number of mitochondria decreased in both groups. There was also a marked increase in the number of SER and liposomes concomitant with a decreased number of Golgi condensing vesicles containing lipoprotein granules. Membranous whorls were also present in the 500 ppm groups.

Rebreathing characteristics of the Bain anesthesia circuit

The humidity output and CO2 elimination of the Bain circuit were tested on a simulated adult patient. The moisture content of inspired gases was found to be adequate when the circuit was used with a minute volume of 8.4 L/min and a fresh gas inflow of 4.9 L/min (65 percent relative humidity at room temperature at the onset of experimentation, rising to 100 percent after 80 minutes). However, the mean inspired CO2 concentration increased from 0.8 percent to 5.5 percent when the fresh gas inflow was decreased from 8 L/min to 3.5 L/min. It is recommended, therefore, that the circuit should not be used for long periods of time without measuring arterial CO2 tension or in situations where intentional hypocarbia is desired.

Coronary risk factor reduction through biofeedback-aided relaxation and meditation

The effects of behaviour modification through education and biofeedback-aided relaxation and meditation on the levels of blood pressure, pulse rate, smoking habits as well as serum cholesterol, triglycerides, and free fatty acids were studied in 18 normotensive, 18 smoking, and 22 hypertensive patients with 18 normotensive controls.The results showed significant reduction in blood pressure, in all the treated groups; highly significant reduction in the number of cigarettes smoked by smokers; and reduction in some of the lipids in all the treated groups, but particularly in the hypertensive group. The therapy appears to be feasible and suitable for wider application. This approach is economical, acceptable to patients, and should be explored further.

Reduction of serum cholesterol and blood pressure in hypertensive patients by behaviour modification

In a pilot study, 14 pharmacologically treated hypertensive patients were given training in psychophysical relaxation exercises, reinforced by biofeedback instruments, for six weeks. The patients were asked to practise twice a day and also incorporate the exercises into everyday activities. In spite of their unchanged drug schedule, their mean blood pressure (B.P.) was reduced from 170.6/102.5 to 147.9/89.14 (P = < .001) while their mean (+/- S.D.) serum cholesterol level was reduced from 241.6 +/- 39.19 to 217.1 +/- 38.12 mg/100 ml (P = < .001). I believe the possibility of one therapy which can reduce two risk factors at the same time should be explored further in a controlled study.

Relaxation and biofeedback techniques in the management of hypertension

In a controlled trial, 27 patients with systemic hypertension were given training in relaxation and meditation using biofeedback procedures. As a result there was a significant reduction in both systolic and diastolic pressure in 77% of the patients. In 50% of the patients it was also possible to reduce antihypertensive drugs, ranging from 33 to 100%. Six-month follow up results show that the benefit can be maintained for a long term provided the patients practice relaxation regularly. The response is unlikely to be a "placebo effect" in the usual meaning. Its genuine therapeutic value should be exploited and reevaluated on a larger scale.

Altered immunologic responsiveness in mastocytoma-bearing mice

Immune responses to sheep erythrocytes were enhanced in mice bearing small mastocytomas soon after injection of a few tumor cells. In contrast, mice with larger tumors after transfer of a greater number of mastocytoma cells and those in the later stages of tumor development after transfer of small numbers of tumor cells showed moderately suppressed immune responses. Transfer of spleen cells from mastocytoma-bearing mice to irradiated recipients resulted in more antibody-forming cells as compared to transfer of splenocytes from normal donor mice. The addition of graded numbers of mastocytoma cells to a constant amount of normal spleen cells transferred to irradiated mice also resulted in enhanced responses and increased spleen weights in the recipients. This increase, in direct proportion to the number of mastocytoma cells transferred, also occurred when Escherichia coli lipopolysaccharide (a T-cell independent antigen) was used to immunize animals given spleen cells from normal mice and mastocytoma cells. Mastocytoma cell-free homogenates or X-irradiated tumor cells also heightened immune responses in recipient mice, which indicated that viable cells were not needed for the effect. Such homogenates, as well as the tumor cells per se, stimulated increased lactate dehydrogenase (LDH) activity in the sera of recipient mice. However, tumor cells passaged in tissue culture for several months, those derived from mice bearing a mastocytoma cell line with a low LDH-stimulatory activity, or UV-irradiated mastocytoma cells with a high LDH-stimulatory activity did not induce enhanced plaque-forming cell responses.