Perioperative transfusion, postoperative infection, and recurrence of head and neck cancer

BACKGROUND

Immunologic effects of perioperative transfusion and postoperative infection have been purported to influence cancer recurrence rates.

METHODS

Records of all head and neck cancer patients having surgical extirpation of the primary tumor and/or regional nodes at our institution over a 5-year period were reviewed. Time to recurrence was the outcome measure. All variables were evaluated via univariate analysis using log rank tests, with Cox proportional hazards used for multivariate analyses.

RESULTS

Univariate analysis identified the following as potential prognostic factors associated with recurrence: nodal stage, total lymphocyte count, overall stage, amount transfused, occurrence of a transfusion, and the American Society of Anesthesiologists status. Various backward stepwise multivariate regression models showed that neither transfusion nor postoperative infection independently influenced recurrence. However, transfusion of 3 or more units did surface as an independent contributor to recurrence, and in certain subgroups there was a trend toward improved survival for those who had a postoperative infection.

CONCLUSIONS

In this series, neither perioperative transfusion nor postoperative infection independently influenced recurrence.

Does cigarette smoking paradoxically increase survival in idiopathic dilated cardiomyopathy? The Washington, D.C., Dilated Cardiomyopathy Study

Recent studies have suggested that patients with idiopathic dilated cardiomyopathy (IDCM) who smoke have an improved prognosis as compared with nonsmokers. We examined this paradoxical finding using data from a population-based study in Washington, D.C. (n = 127). Current smokers were more likely to have a left-ventricular ejection fraction (LVEF) of 25% or greater as compared with IDCM patients who were past smokers or lifelong nonsmokers (p < or = 0.02). The cumulative survival among current smokers at 12 and 24 months was 88.1 and 81.4%, respectively, as compared with 77.9 and 71.6% among past smokers and 74.0 and 64.3% among patients who had never smoked. In a univariate analysis using the proportional hazards model, lifelong nonsmokers and former smokers were about twice as likely to die as compared with smokers, although the association was not significant (p > 0.10). In multivariable analysis, older age, LVEF, and ventricular arrhythmias - but not cigarette smoking-were found to be statistically significant independent predictors of survival (p < or = 0.05).

Evaluation of alternate methods of rapid assessment of endemicity of Onchocerca volvulus in communities in southern Cameroon

Potential diagnostic indicators of onchocerciasis (subcutaneous nodules, depigmentation or leopard skin, microfilaruria, diethylcarbamazine patch test positivity, excoriations, and pruritus) were evaluated in a rain forest region of southern Cameroon for usefulness in rapid assessment of onchocerciasis endemicity in communities. Thirty-two study villages were selected, representing high, intermediate, and low prevalence levels, and 846 adult male residents of these communities 20 or more years of age were examined according to a defined protocol. Skin snips (from each iliac crest) served as the reference standard. Skin snip positivity was 75.5%; the effect of age was minimal. Leopard skin and nodules showed the strongest correlation with both the skin snip prevalence and community microfilarial load, as reflected by the adult male study population. We selected > or = 20% nodules or > or = 20% leopard skin as the most appropriate local criteria for assigning a community to high priority for control, which corresponds to a > or = 90% skin snip prevalence in adult males. While this criteria should not be applied to regions with savannah onchocerciasis, we believe the methodology can and should be used to determine appropriate diagnostic indicators for rapid assessment of Onchocerca volvulus endemicity in regions with different dynamics of transmission and clinical expression of disease.

Respiratory illness, beta-agonists, and risk of idiopathic dilated cardiomyopathy. The Washington, DC, Dilated Cardiomyopathy Study

An epidemiologic study was carried out to examine the possible role of beta-agonists and other respiratory medications in the development of idiopathic dilated cardiomyopathy. Associations with respiratory medications, bronchial asthma, emphysema, and chronic bronchitis were examined by comparing newly diagnosed cases (n = 129) ascertained from five Washington, DC, area hospitals for the period 1990-1992 with neighborhood controls (n = 258) identified by using a random digit dialing technique. The cases and controls were matched on sex and 5-year age intervals and were compared in the analysis using conditional logistic regression methods. A statistically significant association was observed between idiopathic dilated cardiomyopathy and history of emphysema or chronic bronchitis (adjusted odds ratio (OR) = 4.4, 95% confidence interval (CI) 1.6-12.4). The association with bronchial asthma was of borderline significance (adjusted OR = 1.9, 95% CI 0.9-4.2). Associations were also observed with use of oral beta-agonists (adjusted OR = 3.4, 95% CI 1.1-11.0) and beta-agonist inhalers or nebulization (adjusted OR = 3.2, 95% CI 1.4-7.1), as well as with use of oral corticosteroids, inhaled corticosteroids or cromolyn, and theophylline medications. A total of 20.0% (23 of 115) of the cases had a reported history of beta-agonist inhaler use compared with 6.7% (17 of 254) of the controls. The strength of these associations was diminished when the temporal relation between exposure to beta-agonist inhalers or oral preparations and clinical diagnosis of idiopathic dilated cardiomyopathy was taken into account, however, and the associations with duration of beta-agonist medication use were not statistically significant (p > 0.05). The results of this study suggest, but do not prove, that use of beta-agonists has an etiologic role in idiopathic dilated cardiomyopathy.

Acral lentiginous melanoma

Between 1958 and 1990, 82 patients with acral lentiginous melanoma were treated by the Tulane Surgical Service with regional perfusion, excision of lesion, and lymph node dissection. The patient group comprised 27 white men, 29 white women, 18 black men, and 8 black women, with an average age of 61 years. More foot lesions than hand lesions were reported, and all the lack men had foot lesions. In stage I patients, overall 5-year survival rates were 65% at 5 years and 44% at 10 years, with differences by race and gender. The black men did poorest, with a 13% 10-year survival rate. Survival rates were worse with increasing disease stage when calculated using univariate analysis. The 5-year survival rate of all patients with stage III and stage IV disease was 26%. A multivariate analysis was performed in 78 of 82 patients in whom all variables of Clark's level, age, race, stage, and sex were known. A strong relationship was observed between decreasing survival time and increasing Clark's level, with stage of marginal significance. In a multivariate analysis of patients with stage I disease, an increasing level of invasion was found to be significant, with a trend for a relationship to thickness. A trend toward decreased survival time was observed in men and blacks.

Albendazole in the treatment of onchocerciasis: double-blind clinical trial in Venezuela

A double-blind clinical trial was conducted in Monagas State, Venezuela to assess the tolerance and efficacy of albendazole in the therapy of Onchocerca volvulus infection. Forty-nine patients (26 treated and 23 controls) received a 10-day course of albendazole (400 mg/day) or a placebo. Consistent with the excellent tolerance observed, albendazole did not kill microfilariae. However, analysis of changes in microfilarial densities (mf/mg of skin) over one year showed that albendazole was active against O. volvulus, presumably by interfering with embryogenesis. The nature, degree, and duration of this effect remain to be determined.

Effect of administration of diethylcarbamazine on murine leukemia virus (Cas-Br-M) infected mice

Previous studies indicate that decreased serum viral infectivity and viral antigen levels follow oral administration of diethylcarbamazine (DEC) in feline leukemia virus infected cats, even though DEC has not been shown to exhibit in vitro antiviral activity. In this investigation, DEC was given by oral administration or (single dose) IP injection to murine leukemia virus (Cas-Br-M) inoculated mice to permit evaluation of its effect on viral-induced central nervous system disease. The survival of Cas-Br-M inoculated mice receiving DEC in water was significantly prolonged relative to similarly inoculated mice receiving distilled water. Among the Cas-Br-M inoculated mice euthanatized after the study, higher body weights and trend toward less severe brain and splenic lesions were noted in those receiving DEC in drinking water. Given these results, the possible utility of DEC in treatment of retroviral and other infections warrants further study.

Distribution and excretion of capsular antigen after immunization with Haemophilus influenzae type b polysaccharide-Neisseria meningitidis outer membrane protein conjugate vaccine

The occurrence of Haemophilus influenzae type b capsular polysaccharide antigenemia and antigenuria following immunization was studied in 48 healthy 2-month-old infants. Each received a conjugate vaccine consisting of H. influenzae type b capsular polysaccharide covalently linked to Neisseria meningitidis serotype b outer membrane protein at 2 and 4 months of age. Infants were alternated at enrollment for collection of blood and urine after either the first or second dose. Specimens were obtained "early" (2-3 days) after immunization and "late" (7 days) after immunization and assayed for antigen. Antigen was detected in the serum of 3 (6%) of 48 infants, uniformly in the "early" specimen obtained after the first dose of vaccine. Antigenuria occurred in 37 (80%) of 46 infants; for greater than or equal to 7 days in 12 (26%). Antigenuria was frequent after administration of the vaccine but antigenemia was not. These data should be considered in the evaluation of an infant with suspected H. influenzae type b invasive disease.

A method for the evaluation of dose-toxicity relationships in clinical trials

This paper considers a proportional hazards model that describes the relationship between time-dependent cumulative dose of drug and development of toxicity. We estimate probabilities of developing toxicity in both the presence and the absence of competing risks and provide variances for the latter case. Mitoxantrone data collected in Southwest Oncology Group studies illustrate the methods.

Hematologic effects of short-term oral diethylcarbamazine treatment given to chronically feline leukemia virus-infected cats

Diethylcarbamazine (N,N-diethyl-4-methyl-1-piperazine carboxamide [DEC]) is widely used, especially in tropical regions, to prevent and treat filariasis. The antifilarial effect of this drug has been attributed to immunomodulation. Evidence is accumulating to indicate that DEC may mitigate the course of feline leukemia virus infection (FeLV) in cats. Previous studies have suggested that continuous oral DEC treatment given shortly after evidence of FeLV infection prevents or delays lymphopenia and prolongs survival. The present study focuses on the hematologic effects of one month oral DEC treatment given to adult chronically FeLV-infected cats and uninfected cats as compared to untreated FeLV-infected cats. Such treatment frequently resulted in abruptly lowered peripheral lymphocyte counts in chronically FeLV-infected cats. Further studies are warranted to evaluate whether administration of DEC could eliminate circulating retroviral-infected cells.

Effect of continuous oral diethylcarbamazine treatment on lymphocyte counts of feline leukemia virus-infected cats

In previous studies, administration of diethylcarbamazine (DEC) resulted in increased serum antibody titers to feline oncornavirus-associated cell membrane antigen (FOCMA) in cats infected with feline leukemia virus (FeLV). FeLV infection of cats frequently results in immunosuppression associated with lymphopenia. The present investigation demonstrated that chronic administration of DEC prevented or delayed severe lymphopenia in two FeLV-infected offspring of an FeLV-infected queen as compared to two untreated littermates.

Charity Hospital experience with long-term survival and prognostic factors in patients with breast cancer with localized or regional disease

Long-term survival, the prognostic effects of race, age, tumor size, number of positive nodes, and presence of grave signs (fixation, peau d'orange/edema, dimpling/retraction, satellite nodules, and ulceration) in this distribution of estrogen receptors (ERs) and progesterone receptors (PRs) were studied in 2480 patients (1815 blacks, 665 whites) diagnosed with localized or regional breast cancer at Charity Hospital of Louisiana at New Orleans (CHNO) from 1948 to 1985 and followed up in the CHNO Tumor Registry. Breast cancer-specific survival rates were 57%, 45%, 41%, 39%, 38%, and 35% at 5, 10, 15, 20, 25, and 30 years, respectively. Size of tumor, clinical status of nodes, and degree of fixation were important prognostic clinical factors, and number of nodes was an important pathologic factor with no additional value of the "grave signs." Size and fixation were related. Independent of size, clinical and pathologic status and fixation were related. ER was related to age and PR was related to number of nodes. The excess mortality from breast cancer at later intervals from diagnoses was small compared with mortality from other causes. Some, but not all, clinical findings were important prognostic indicators. ER and PR were related to some variables with unclear meaning.

Prevalence of giardiasis in patients with cystic fibrosis

A group of 107 patients with cystic fibrosis and a control group of 64 normal members of households of patients with cystic fibrosis were surveyed for Giardia lamblia cysts and trophozoites by counterimmunoelectrophoresis of fecal samples. The patient group had a significantly higher rate of infestation than the control group (28.0% vs 6.3%, P = 0.0006), and the disparity between the two groups increased with age (P = 0.005). Aside from cystic fibrosis, all risk factors examined were without influence, except for the presence of household members less than or equal to 5 years of age. We conclude that our patients with cystic fibrosis have a previously unrecognized increased prevalence of giardiasis compared with that in a control population.

Long term effect of gynecologic age on somatic growth of children

A sample of New Orleans black primiparous women under 25 years of age, participants in the national collaborative perinatal study, and their singleton children were studied to determine the relationship of maternal gestational age (GeA), gynecologic age (GyA) and size for GeA (S/GeA) on the child's growth over seven years observation. Early childbearers (less than 4 years GyA) had a somewhat higher proportion of preterm births than the late group (greater than or equal to 4 yrs GyA). A repeated measures analysis of variance after correction for maternal prepregnant weight and weight gain, demonstrated the early group remained smaller throughout the seven years in weight, length and head circumference. Preterm infants showed catch up by one year in height and weight in both Early and Late Groups, though the Early Preterm infants failed to catch up with the other groups in head circumference. In this lower socio economic group, the legacy of early childbearing appears to be smaller child body dimensions which are likely permanent.

Cardiotoxicity in patients treated with mitoxantrone: Southwest Oncology Group phase II studies

A model describing the development of cardiotoxicity as a function of cumulative dose of a drug and other covariates is presented. Methods are given for testing and illustrating a cumulative dose effect. Also, equations for estimation of the probability of developing cardiotoxicity in the presence or absence of competing risks are given. The methods are illustrated for mitoxantrone by means of data obtained from Southwest Oncology Group studies.

Factors influencing the survival of patients with regional melanoma of the extremity treated by perfusion

Patients with regional metastases of malignant melanoma (75 with Stage IIIA soft tissue metastases, 124 with Stage IIIB nodal metastases and 75 with Stage IIIAB soft tissue and nodal metastases) treated by regional perfusion between 1957 and 1982 were retrospectively studied to identify prognostic factors relating to survival. In patients with Stage IIIB disease, the melanoma specific cumulative survival rates at five years was 72 per cent for one, 33 per cent for two to three and 20 per cent for four or more positive lymph nodes. In patients with Stage IIIAB disease, those with one node had a better survival rate at five years than those with multiple nodes (45 versus 25 per cent). In patients with Stage IIIA melanoma, two groups were identified based upon the results of prior treatment--those with and without prophylactic lymph node dissection (PLND) at the time of primary therapy. The factors associated with decreased survival rates in patients with PLND were: 1, increasing age; 2, presence of subcutaneous or both subcutaneous and dermal metastases, and 3, treatment at normothermic temperatures or earlier date of treatment. No significant factors were found in the group without PLND; however, the survival time was similar to that for patients with Stage IIIAB and one positive node (45 per cent at five years). Knowledge of these factors is important in assessing the prognosis and establishing randomization criteria for prospective studies evaluating various forms of therapy.

Luminal gastric somatostatin-like immunoreactivity in response to various stimuli in man

This study investigates release of somatostatin-like immunoreactivity (SLI) into the gastric lumen of five healthy human subjects in response to pharmacological stimuli (pentagastrin and secretin) and physiological stimuli (sham feeding and intrajejunal perfusion of elemental diet). Basal and poststimulation gastric juice aspirates were collected at 15-min intervals, extracted with acetone, and SLI determined by radioimmunoassay, with these results: A considerable amount of SLI was secreted during the basal period. Pentagastrin stimulated SLI release quickly and was associated with increased acid secretion. Both secretin and sham feeding increased SLI only slightly. During intrajejunal perfusion of the elemental diet, SLI increased significantly, was associated with decreased acid secretion, and rapidly returned to basal level when elemental diet was replaced by saline. Basal levels of gastric luminal SLI thus showed distinct changes in response to each stimulus. Although the physiological action of luminal SLI remains to be studied, its levels may reflect gastric D-cell activities.

Long-term survival and prognostic factors in breast cancer patients with localized (no skin, muscle, or chest wall attachment) disease with and without positive lymph nodes

Uncertainty exists regarding the magnitude of excess mortality from localized breast cancer at long follow-up times (greater than 15 years) since diagnosis and regarding the effects of race and age as prognostic factors at all follow-up times. Long-term survival was determined in 1141 patients (311 white, 830 black) diagnosed as having localized breast cancer with and without positive axillary lymph nodes, but without any signs of complete or incomplete skin, muscle, or chest wall attachment. Survival curves were estimated by means of actuarial methods; prognostic factors were evaluated with the Cox's regression analysis. Survival from all causes was 62%, 43%, 33%, 25%, and 18% at 5, 10, 15, 20, and 30 years, respectively. Breast cancer-specific survival was 76%, 65%, 63%, 61%, and 59% at 5, 10, 15, 20, and 30 years, respectively. Breast cancer-specific hazard rates exceeded those expected in the general population by 119 times, 53 times, 12 times, and 6 times at 0 to 5, 5 to 10, 10 to 20, and 20 to 25 years, respectively. Of the 395 patients enrolled after 1968 who had modified radical or radical surgery, 338 had known number of positive nodes and size of tumor. Breast cancer-specific survival was significantly increased with: a decreasing number of positive lymph nodes, 0, 1 to 3, and 4 or more (P = 0.000); later year of diagnosis (1974 or before versus 1975 or later) (P = 0.000); and possibly, tumor size of 7.0 cm or less (P = 0.09). When these variables were controlled, no significant association of age at diagnosis or race with breast cancer-specific survival was found. These data suggest that the number of nodes, year of diagnosis and, possibly, tumor size are important prognostic factors for survival, but race and age are not. Also, excess mortality may exist at late intervals; however, it is small in relation to other causes.

Myelography with metrizamide: effect of contrast removal on side effects

Moderately severe side effects, such as prolonged headache, nausea, vomiting, or psychoneurologic symptoms, were noted in 27 (32%) of 84 patients in whom the contrast medium was not removed. Conversely, among 73 patients from whom 20-25 ml of cerebrospinal fluid with the contrast medium was removed, only 10 (14%) experienced adverse effects, a statistically significant reduction. Although new contrast agents, such as iohexol and iopamidol, are reportedly less toxic than metrizamide, the contrast-removal technique described here may be indicated when large amounts of any contrast medium are used.

Long-term survival and prognostic factors in patients with regional breast cancer (skin, muscle, and/or chest wall attachment)

Between 1948 and 1981, 1230 patients were diagnosed as having regional (skin, muscle, or chest wall attachment) breast cancer, and long-term survival was studied. In all patients, overall survival was 33% at 5 years, 19% at 10 years, and 9% at 20 years. Significant excess mortality due to breast cancer was observed throughout the 20-year follow-up period (P less than 0.002). The risk of breast cancer was highest in the 5-year period following diagnosis, and declined steadily from that time. Additionally, 308 patients diagnosed since 1968 were studied for the effect of prognostic factors. Clinical status of nodes (positive or negative) and presence or absence of peau d'orange were found to be significant prognostic factors in those patients. In those receiving radical surgery, the number of nodes and presence or absence of peau d'orange were found to be of prognostic significance. No effect of race, age, year of diagnosis, site of attachment, type of fixation, ulceration, edema, size of tumor, satellite nodules, or dimpling retraction on breast-cancer-specific survival was observed when the nodal status and peau d'orange were controlled. These data demonstrate that mortality in regional breast cancer is significant and is highly dependent on peau d'orange and nodal status.

Pancreatic immunoreactive somatostatin and diabetes mellitus

Pancreatic secretions were collected during endoscopic retrograde cholangiopancreatography from 15 subjects without pancreatic, biliary, or hepatic diseases, 11 patients with non-insulin-dependent diabetes, and 11 patients with insulin-dependent diabetes. Pancreatic secretion was stimulated by the intravenous administration of one unit of secretin per kilogram of body weight. Immunoreactive somatostatin (IRS) in the pancreatic juice of the nondiabetic subjects ranged from 43 to 97 pg/ml, in non-insulin-dependent diabetics from 5 to 3872, and in the insulin-dependent diabetics from 0 to 2093. IRS in insulin-dependent diabetics under good plasma glucose control ranged from 0 to 281 pg/ml, compared to those under poor control who ranged from 518 to 2093 pg/ml. These results indicate that IRS in pancreatic juice is higher in poorly controlled insulin-dependent diabetics than in well controlled insulin-dependent diabetics and nondiabetics. Whether these changes in IRS are purely secondary phenomena or play some pathogenetic role in the disturbed metabolism of diabetes remains to be proven. The chromatographic profile of IRS in pancreatic juice on both gel filtration and high-performance liquid chromatography has indicated that these IRS moieties represent somatostatin 14 and somatostatin 28.

Effect of pregnancy upon malignant melanoma

Results of this study suggest melanomas diagnosed, initiated or stimulated during pregnancy have worse prognoses than do those of patients not having this history. For those female patients who have had melanomas without a history of the preceding factors, it appears they can become pregnant following the diagnosis and treatment of melanoma without increased hazard. Further biochemical studies on hormone receptors and correlation with the clinical course are needed to clarify the influences of endocrines on malignant melanomas.

Trimethoprim and rifampin in combination for chemoprophylaxis of household contacts of patients with invasive infections due to Haemophilus influenzae type b

We compared the effectiveness of rifampin-trimethoprim in fixed combination (3.75:1) to rifampin alone in the eradication of Haemophilus influenzae type b carriage among contacts of patients with invasive infection caused by this organism. The study population was composed of 127 index patients and 620 contacts. Twenty-six percent of contacts were colonized. Rifampin-trimethoprim eradicated carriage in 77.6% of contacts (71.1% in contacts less than 5 years, 84.2% in contacts greater than or equal to 5 years) whereas rifampin eradicated carriage in 69.9% of contacts (56.4% in contacts less than 5 years, 81.8% in contacts greater than or equal to 5 years). A single isolate resistant to rifampin and rifampin-trimethoprim was encountered. The eradication rate achieved with this regimen of rifampin-trimethoprim was too low to recommend its routine use. However, a higher dose or longer course might merit clinical trial.

Breast cancer as analyzed by the human tumor stem cell assay

Patients with primary and recurrent carcinomas of the breast were studied by the human tumor stem cell assay to determine if (1) colonies would form from breast cancer specimens, (2) growth in the culture would equate with aggressiveness of disease, (3) the assay would yield specific information on drug responsiveness, and (4) the assay would yield nonspecific information on drug responsiveness. Colony counts ranged from 0 to 363. There was no significant difference in median colony counts by pathologic stage of disease or site. Among stage IV patients presenting for treatment with primary disease, those with colony counts greater than 10 had a mortality rate of 4.7/1000 person-days; there were no deaths among those with colony counts less than or equal to 10 (P = 0.042). Stage IV patients presenting with recurrent disease showed no association between colony counts and survival (P = 0.53). No significant relationship between colony counts and disease-free intervals was observed among stages I, II, and III patients (P = 0.10). Drug sensitivity in vitro was found in 14% of the cultures with colony counts greater than or equal to 30. The only complete clinical responses in stage IV patients occurred in two patients with 0 colony counts. These data demonstrate that colonies grow from breast cancer specimens, that colony formation in vitro may be related to aggressiveness of growth in vivo in patients presenting with stage IV disease, that drug sensitivity is demonstrated in few cultures, and that patients with metastatic disease who have complete response to systemic therapy may be identified by lack of growth in the culture.

Rifampin chemoprophylaxis for household contacts of patients with invasive infections due to Haemophilus influenzae type b

To determine the efficacy of rifampin chemoprophylaxis in eradication of oropharyngeal carriage of Haemophilus influenzae type b, we conducted a multicenter, double-blind, placebo-controlled trial among household contacts of patients hospitalized for invasive HIB infection. Seventy-nine index patients and 400 close contacts were studied; 26.5% of contacts were colonized. The efficacy of rifampin (10 mg/kg/dose, 600 mg/dose maximum, twice daily for two days) in eradicating carriage was 52% and varied with age (75.6% in persons greater than or equal to 5 and 27% in those less than 5 years). Eradication rates in those less than 5 years were not significantly better than for placebo. No resistant isolates were encountered in sensitivity testing. The low efficacy of this rifampin regimen in young children precludes its routine use as a chemoprophylactic agent for family contacts. The occurrence of three cases of invasive HIB infection in individuals outside the defined contact group raises concern regarding the efficacy of any chemoprophylactic regimen.

Experimental murine candidiasis: cell-mediated immunity after cutaneous challenge

Male CBA/J mice, sensitized by cutaneous inoculation with viable Candida albicans blastospores, were used to study in vivo and in vitro cellular immune responses. Three antigens of C. albicans, viz., a cell wall glycoprotein (GP), a membrane extract (ppt-HEX), and soluble cytoplasmic substances (SCS), were used in vitro in a lymphocyte stimulation assay, whereas the GP and ppt-HEX were used in vivo to detect delayed hypersensitivity by the footpad assay. Delayed hypersensitivity to GP and ppt-HEX was transferred from sensitized donors to naive recipients with peritoneal exudate cells and not with serum. Moreover, the transfer of the reactivity to ppt-HEX was abrogated by the prior treatment of the transfer suspension with anti-theta 1.2 serum and complement. The in vitro lymphocyte response to GP and ppt-HEX correlated qualitatively with the in vivo responses. SCS, a preparation shown to be ineffective in vivo previously, did stimulate lymphocytes from sensitized animals in vitro. The in vitro response to Candida antigens, as well as phytohemagglutinin, was abolished by treatment of the lymphocyte suspension with anti-thymocyte 1.2 serum before assay, whereas anti-immunoglobulin serum had less effect on these responses. The in vivo and in vitro reactivity to the Candida antigens, therefore, was dependent upon viable T-lymphocytes. Preliminary specificity studies were carried out in the lymphocyte stimulation assay, using lymphocytes from mice infected with C. albicans tested against ppt-HEX preparations extracted from two other species of Candida, C. tropicalis and C. guillermondii, and from two other pathogenic yeast forms, Histoplasma capsulatum and Blastomyces dermatitidis. Significant cross-reactivity was observed with C. tropicalis only, a species which is known to be serologically related to C. albicans.

Nonequilibrium facilitated oxygen transport in hemoglobin solution

We have used the quasi-linearization method to obtain numerical solutions to the equations which describe steady-state diffusion of oxygen through layers of hemoglobin solution. The numerical solutions show how the facilitated flux of oxygen depends upon the layer thickness, reaction-rate coefficients, and other parameters of the system. The results indicate that steady-state oxygen diffusion in layers of hemoglobin solution, similar to those studied by Scholander, should be adequately described by the models which assume chemical equilibrium exists throughout the layer, but for layers of concentrated hemoglobin solution about the thickness of a human erythrocyte, the facilitation of oxygen diffusion should be much less than the equilibrium models predict.