Things you wanted to know (but might have been afraid to ask) about how and why to explore and modulate brain plasticity with non-invasive neurostimulation technologies.

Brain plasticity can be defined as the ability of local and extended neural systems to organize either the structure and/or the function of their connectivity patterns to better adapt to changes of our inner/outer environment and optimally respond to new challenging behavioral demands. Plasticity has been traditionally conceived as a spontaneous phenomenon naturally occurring during pre and postnatal development, tied to learning and memory processes, or enabled following neural damage and their rehabilitation. Such effects can be easily observed and measured but remain hard to harness or to tame 'at will'. Non-invasive brain stimulation (NIBS) technologies offer the possibility to engage plastic phenomena, and use this ability to characterize the relationship between brain regions, networks and their functional connectivity patterns with cognitive process or disease symptoms, to estimate cortical malleability, and ultimately contribute to neuropsychiatric therapy and rehabilitation. NIBS technologies are unique tools in the field of fundamental and clinical research in humans. Nonetheless, their abilities (and also limitations) remain rather unknown and in the hands of a small community of experts, compared to widely established methods such as functional neuroimaging (fMRI) or electrophysiology (EEG, MEG). In the current review, we first introduce the features, mechanisms of action and operational principles of the two most widely used NIBS methods, Transcranial Magnetic Stimulation (TMS) and Transcranial Current Stimulation (tCS), for exploratory or therapeutic purposes, emphasizing their bearings on neural plasticity mechanisms. In a second step, we walk the reader through two examples of recent domains explored by our team to further emphasize the potential and limitations of NIBS to either explore or improve brain function in healthy individuals and neuropsychiatric populations. A final outlook will identify a series of future topics of interest that can foster progress in the field and achieve more effective manipulation of brain plasticity and interventions to explore and improve cognition and treat the symptoms of neuropsychiatric diseases.

Lactobacillus pentosus strain b240 suppresses pneumonia induced by Streptococcus pneumoniae in mice.

AIMS: Oral administration of probiotics has been known to improve inflammatory responses against infectious diseases. Here, we describe the inhibitory effect of oral intake of heat-killed Lactobacillus pentosus strain b240 (b240) on pneumococcal pneumonia in a murine experimental model. METHOD AND RESULTS: The mice treated with oral b240 for 21 days before Streptococcus pneumoniae infection exhibited prolonged survival time and less body weight loss, compared with saline-treated control mice. Mild pneumonia with significantly reduced secretion of inflammatory cytokines/chemokines according to related mitogen-activated protein kinase signalling molecules (phosphorylated c-Jun N-terminal kinase) was found in b240-treated mice, whereas severe pneumonia with hypercytokinemia was evident in control mice. Prominent reduction in the number of pneumococci and elevated expression of Toll-like receptor 2 and 4 in the lung tissues was concomitantly noted in b240-treated mice. CONCLUSIONS: These findings indicate that b240 has inhibitory effects on pneumococcal pneumonia induced by Strep. pneumoniae infection and improves inflammatory tissue responses, resulting in reduced damages to the respiratory tissues. SIGNIFICANCE AND IMPACT OF THE STUDY: These results demonstrate that oral administration of b240 might protect host animals from Strep. pneumoniae infection by augmentation of innate immune response.

Involvement of Rho kinase in the pathogenesis of acute pulmonary embolism-induced polystyrene microspheres in rats.

Acute pulmonary embolism (PE) is a life-threatening disease, and several vasoconstrictors, including endothelin-1 (ET-1), play a key role in vasoconstriction and hypoxemia during the development of PE. Rho kinase is activated by various vasoconstrictors resulting in vascular contraction and remodeling. Recent evidence has revealed an important role of Rho kinase in the pathogenesis of systemic and pulmonary vascular diseases. However, contribution of Rho kinase in PE remains unclear. We thus investigated the role of Rho kinase in the PE rat model induced by intrajugular administration of polystyrene microspheres (mean diameter, 26 microm). At 6 h following the administration of microspheres (1.5 ml/kg), right ventricular systolic pressure (RVSP) was higher in the PE than in the control rats (15.8 +/- 1.6 vs. 32.9 +/- 7.5 mmHg). Arterial oxygen tension was lower (92.3 +/- 12.5 vs. 66.0 +/- 17.7 Torr), and alveolar-arterial difference in oxygen partial pressure was higher (3.9 +/- 3.8 vs. 36.5 +/- 26.9 Torr) in the PE rats. Western blotting analysis revealed upregulation and downregulation in expression of vascular cell adhesion molecule-1 and endothelial nitric oxide synthase in lungs from the PE rats, respectively, and radioimmunoassay demonstrated an increase in plasma ET-1 levels. Lung Rho kinase alpha expression was greater in the PE rats. At 5 h following administration of microspheres (0.75 ml/kg), intravenous Rho kinase inhibitors HA1077 and Y27632 (3 mg/kg each) attenuated elevation of RVSP (22.0 +/- 3.7, 17.1 +/- 3.2, 14.3 +/- 2.6 mmHg, PE, PE+HA1077, PE+Y27632) and the severity of hypoxemia (66.3 +/- 16.2, 94.9 +/- 23.0, 89.1 +/- 8.5 Torr, PE, PE+HA1077, PE+Y27632) in the PE rats. These results suggest that pulmonary endothelial dysfunction and activation of Rho kinase may contribute to the potentiation of vasoconstriction and hypoxemia in the PE rats.

[Retroperitoneal pyogenic infections with uncertain etiopathogenesis. Diagnostic and therapeutic difficulties]. / Supuratiile retroperitoneale cu etiologie imprecisa. Dificultati diagnostice si terapeutice.

Retroperitoneal pyogenic collections can appear in most distinct pathological situations. Establishing the topography and pathogenic route are essential steps in developing the therapeutic attitude. Diagnosis of suppurative retroperitoneal process complicating a previously attested disease is less difficult. The challenges appears in that cases with atypical, clinical picture, which presents associated pathological states (diabetes mellitus, chronic alcoholism, behavioral disturbances), as well as in primary retroperitoneal infections (psoas abscess, infected retroperitoneal tumors) or in that situations in which the patient presents toxico-septic shock on admission. A retrospective study on the patients with retroperitoneal infections admitted in our Clinic between 1996 - 2006 was carried out. We selected the cases in which preoperative etiopathogenic diagnosis was uncertain (in some situations the exact etiopathogenic route remaining unknown even postoperatively). The aim of this study is to evaluate the factors contributing to this, and how therapeutic attitude was influenced.

High-copy-number and low-copy-number plasmid vectors for lacZ alpha-complementation and chloramphenicol- or kanamycin-resistance selection.

Three types of alpha-complementation plasmid vectors were constructed which contain a chloramphenicol- or kanamycin-resistance (CmR or KmR) gene and polylinker cloning sites within the coding region of lacZ'. These vectors are essentially based on high- or low-copy-number replicons. The low-copy-number vectors, 3.61 kb in size, confer CmR and contain the pSC101 replicon and pUC8-/pUC9-type polylinker. On the other hand, the high-copy-number vectors, 2.21 to 2.68 kb in size, confer either CmR or KmR, and contain the pBR322 replicon and pUC18-/pUC19-type or other modified polylinkers. All cloning sites except HindIII and SmaI sites in the KmR vectors are unique in each plasmid. Since almost all frequently used plasmid vectors confer ampicillin resistance, these vectors may be useful to simplify the subcloning/DNA joining experiments due to unnecessity of radioisotope labelling, size fractionation and purification of foreign DNA segments.

Induction of host DNA synthesis in senescent human diploid fibroblasts by infection with human cytomegalovirus.

A human diploid fibroblast strain, TIG -1, ceased to proliferate at about 60-62 population doubling level. The percentage of nuclei incorporating [3H]thymidine during 24-h culture in fresh medium containing 10% fetal bovine serum was less than 2% in the senescent cells used in this study. Infection of these cells with human cytomegalovirus (HCMV), strain AD-169, increased the percentage of [3H]thymidine-labeled cells by about ten-fold. Equilibrium density gradient centrifugation analysis of purified DNA from infected cells showed that cellular DNA synthesis was stimulated preceded by the viral DNA synthesis. Ultraviolet irradiation of HCMV reduced the ability to induce DNA synthesis. Equilibrium density gradient centrifugation analysis of DNA which was labeled with 5-bromodeoxyuridine indicated semiconservative replication rather than repair synthesis. These results suggested that in a considerable fraction of human senescent cells host DNA replication could be reinitiated by infection with HCMV, but not by the addition of fetal bovine serum.

Estimation of myocardial perfusion and viability using simultaneous 99mTc-tetrofosmin--FDG collimated SPECT.

UNLABELLED: This study was designed to elucidate the usefulness of crosstalk correction for dual-isotope simultaneous acquisition (DISA) with 99mTc-tetrofosmin and FDG in estimating myocardial perfusion and viability. METHODS: Eighteen patients with coronary artery disease were studied. First, SPECT was performed with a low-energy high-resolution collimator after a single injection of 99mTc-tetrofosmin (single 99mTc-tetrofosmin). Second, PET and DISA with an ultra-high-energy collimator were performed after glucose loading and an injection of FDG. DISA was designed to operate with simultaneous 3-channel acquisition, and weighted scatter correction of crosstalk from the 18F photopeak to the 99mTc photopeak was performed by modification of an existing dual-window technique. The FDG SPECT images were compared with the images obtained by PET. Both crosstalk-corrected and uncorrected 99mTc-tetrofosmin images were generated and compared with the single 99mTc-tetrofosmin images. RESULTS: Regional percentage uptake of FDG agreed well between DISA and PET. However, regional percentage uptake of 99mTc-tetrofosmin was generally higher on the uncorrected 99mTc-tetrofosmin images than on the single 99mTc-tetrofosmin images, especially in areas of low flow (percentage count of 99mTc-tetrofosmin > or = 50%). The crosstalk correction contributed to improving the agreement between regional percentage uptakes and significantly improved the detectability of myocardial perfusion-metabolism mismatching. CONCLUSION: With 3-channel acquisition and weighted-scatter correction of crosstalk from the 18F photopeak to the 99mTc photopeak, DISA with 99mTc-tetrofosmin and FDG is feasible for assessing regional myocardial perfusion and viability.

Attenuation correction for cardiac dual-head gamma camera coincidence imaging using segmented myocardial perfusion SPECT.

UNLABELLED: The diagnostic accuracy of cardiac FDG imaging obtained with the dual-head coincidence gamma camera (DHC) is impaired by artifacts induced by nonuniform attenuation. This study proposed a new method (registration and segmentation method for attenuation correction [AC-RS]) to correct these attenuations in the chest region without the need for additional hardware or expensive transmission scanning equipment. METHODS: Before DHC imaging, 99mTc-tetrofosmin SPECT was performed using dual-energy acquisition from both the photopeak and Compton scatter windows. The scatter window images of the 99mTc-tetrofosmin were then registered 3-dimensionally with the cardiac DHC images and segmented into anatomic regions to obtain body and lung contours by applying the optimal threshold method on localized histograms. Theoretic attenuation coefficient values were assigned to the corresponding anatomic regions, and the DHC emission images were reconstructed using these attenuation correction factors. The results were quantitatively evaluated by imaging a cardiac phantom filled with a uniform solution and placed in a chest phantom. Eight nondiabetic subjects were also examined using this technique, and the results were compared with those of measured attenuation-corrected PET images. RESULTS: Use of this technique in phantom and clinical studies decreased the degree of artifacts seen in the inferior wall activity and corrected the emission images. When the results were compared with those of PET scans, the regional relative counts of the uncorrected DHC scan did not correlate with the results of the PET scan. However, the regional relative counts of the AC-RS-corrected DHC scan exhibited a linear correlation with the results of the PET scan (r = 0.73; P < 0.001). CONCLUSION: Reasonably accurate attenuation-corrected cardiac DHC images can be obtained using AC-RS without the need for transmission scanning.

Sympathetic reinnervation demonstrated on serial iodine-123-metaiodobenzylguanidine SPECT images after cardiac transplantation.

The transplanted heart is without autonomic nervous control in the early postsurgical period. We present here a case of cardiac transplantation in which 123I-metaiodobenzylguanidine (MIBG) SPECT and an exercise-loading test were used to monitor the sympathetic reinnervation. The distribution of myocardial 123I-MIBG uptake extended with time from 1 to 2 yr after surgery. However, functional improvement, estimated by the heart rate response to exercise, was not discernable during this period. The findings in this case suggest the feasibility of 123I-MIBG SPECT imaging in the serial monitoring of sympathetic reinnervation after transplantation and that scintigraphic evidence of reinnervation precedes functional recovery.

Fluorine-18-fluorodeoxyglucose PET identification of cardiac metastasis arising from uterine cervical carcinoma.

Cardiac metastasis of uterine cervical carcinoma is rare. We describe a patient with a past history of uterine cervical carcinoma who presented with metastasis to the heart, lungs and distant lymph nodes 3 yr after surgery and chemotherapy. Since the patient complained of chest pain and demonstrated electrocardiogram abnormalities, we performed echocardiography, electron beam CT and MRI, which revealed a tumor in the right ventricular wall. The tumor was assessed by 67Ga scintigraphy and 18F-fluorodeoxyglucose (FDG) PET scanning. The mean differential 18F-FDG uptake ratio of the tumor was 7.9, suggesting malignancy, which was later confirmed by myocardial biopsy. Information about the extent of the tumor and partial necrosis within it was provided by 18F-FDG PET. Although both radionuclide imaging techniques also detected metastatic lesions in the lungs and lymph nodes, 18F-FDG PET scanning detected small lesions more sensitively than 67Ga scintigraphy.

Primary structures of the ColE2-P9 and ColE3-CA38 lysis genes.

The lysis genes of plasmids ColE2-P9 and ColE3-CA38 were identified by DNA sequencing and electrophoretic analysis of the products of both wild type and artificially introduced ochre mutant genes. The E2 and E3 lysis genes had identical primary structures and were shown to encode 47 amino acids with a calculated molecular weight of 4,861, which is much smaller than that proposed previously for the ColE3-CA38 lysis protein. They are homologous with ColDF13 gene H, except in their 3'-portions. The nine C-terminal amino acids of the E2 and E3 lysis proteins proved to be non-essential for the lysis phenotype.

Introduction of DT40 cells into chick embryos.

AIM: To examine the transfection of exogenous genes into chick embryos, applying the characteristics of avian leukosis virus (ALV)-induced chicken B cell line DT40 to the production of chimeric birds. METHODS: The DT40 cells incorporated with exogenous gene ( lacZ constructs encoding Escherichia coli beta-galactosidase: beta-gal) were introduced into chick embryos by the injection of cells into stage X blastoderm. Manipulated eggs were incubated for 3 (trial 1) or 6 (trial 2) days, and the expression of lacZ DNA was detected by a histochemical staining method of beta-galactosidase and polymerase chain reaction (PCR) analysis. RESULTS: The survival rates of the manipulated embryos incubated for 3 days (stage 18-20: trial 1) and 6 days (stage 28, 30: trial 2) were about 42% and 38%, respectively. The expression rates of the lacZ gene in the embryos in the trials 1 and 2 were about 60% and 23%, respectively, for the survived embryos. CONCLUSION: The rate of embryonic viability and expression rate of introduced genes were not so high, but it suggested the possibility of utilizing the DT40 cells as a vector for carrying exogenous genes into chick embryos.

Baumkuchen map analysis to detect postural cerebral hypoperfusion with upright 99Tcm-HMPAO brain SPET.

We have evaluated a polar cortical flow Baumkuchen map (BK map), constructed from projection data by inwardly layering cortical flow stripes from the base to the apex, to detect postural cerebral hypoperfusion using 99Tcm-HMPAO brain SPET. A circular cortical perfusion outline was constructed from sinogram data at a 20% threshold; a ring was then formed by constructing an inner line with a radius equal to half that of the outer line. This ring on the transaxial image was superimposed onto the cortical image, then divided into 60 portions at 6 degrees intervals from the centre. The maximal number of counts per pixel within each sector was determined, translated into polar coordinate profiles and displayed as a polar map. We studied 11 patients with unilateral stenosis of the internal carotid artery or middle cerebral artery (MCA) and 7 patients without stenosis, using upright and supine (rest) 99Tcm-HMPAO brain SPET Cerebral perfusion was visibly altered on the BK maps of all 11 patients with arterial stenosis and on the transaxial images of 8 of them. A semi-quantitative analysis of the BK maps using a ratio of the counts in the regions of interest over the right and left MCA areas, showed that the mean of the ratios was significantly lower in the upright images than in the upright + rest and rest images (P = 0.0044 and 0.0033, respectively). Although the difference in the means of the ratios between the upright and upright + rest images was significant for both the BK map and transaxial image data (P = 0.0044 and 0.0051, respectively), the BK map was accurate in detecting changes in perfusion in the upright position. We conclude that BK map analysis is useful for detecting changes in patients examined using upright brain SPET.

Endoscopic variceal ligation (EVL) combined with partial splenic embolization (PSE).

BACKGROUND/AIMS: The effectiveness of reducing the recurrence rate of esophageal varices by combining partial splenic embolization (PSE) with endoscopic variceal ligation (EVL) was investigated. METHODOLOGY: Patients with complete eradication of esophageal varices were collected as study cases with the following results: 31 cases with PSE and EVL (PSE+EVL group), 25 cases with EVL alone (EVL group), and 33 cases with EIS alone (EIS group). The cumulative recurrence rates were obtained by observing new varices. RESULTS: The cumulative recurrence rates at 6 months were 21.1% in the PSE+EVL group, 58.1% in the EVL group and 32.5% in the EIS group. Those at 1 year were 37.0%, 70.7% and 50.2%, respectively, and those at 2 years were 58.1%, 80.4% and 73.0%, respectively. For all 3 time periods, recurrence rates of the PSE+EVL group were significantly lower than those of the EVL group (p=0.042). Cumulative rates in the PSE+EVL group tended to be lower than those in the EIS group. Further analysis was made on the comparative recurrence rates of the 3 groups, according to Child's classification. The cumulative recurrence rates in Child A cases did not significantly differ between the 3 groups. Cumulative rates in Child B cases were significantly lower in the PSE+EVL group than in the EVL group (p=0.032), and those in the PSE+EVL group tended to be lower than those in the EIS group. These trends were observed between the PSE+EVL group and the EVL group in Child C cases, while cumulative rates did not show differences between the PSE+EVL group and the EIS group. CONCLUSIONS: It was inferred that PSE-combined EVL therapy is a very effective therapy for achieving long-term complete eradication of esophageal varices.

Long-term results of modified distal splenorenal shunts for the treatment of esophageal varices.

BACKGROUND/AIMS: Long-term results were compared for 3 types of distal splenorenal shunt for the treatment of esophageal varices. METHODOLOGY: Between July 1983 and December 1997, 45 patients with esophageal varices underwent distal splenorenal shunt. Group 1 underwent standard distal splenorenal shunt (n = 11). Group 2 underwent distal splenorenal shunt with splenopancreatic disconnection (n = 11). Group 3 underwent distal splenorenal shunt with splenopancreatic disconnection and gastric transection (n = 23). RESULTS: Additional treatment for recurrent varices was required in group 1, (n = 1, 9.1%), group 2 (n = 2, 18.2%), and group 3 (n = 1, 4.3%). All of the patients with recurrent varices developed a shunt stenosis within the 1st year after distal splenorenal shunt. The prevalence of hyperammonemia in group 1 was 40.0% at 1, 5, and 10 years. In group 2, the prevalence was 14.3% at 1 year, 31.4% at 5 years, and 54.3% at 10 years. In group 3, the prevalence was 0% at 1 year, and 9.1% at 5 and 10 years. The differences between group 3 and groups 1 and 2 were significant (P < 0.01). The cumulative survival rates at 1 year were 90.9%, 63.6%, and 95.7% for groups 1, 2, and 3, respectively. At 10 years, the cumulative survivals rates were 70.7%, 63.6%, and 69.4% for groups 1, 2, and 3, respectively. There were no significant differences in survival between the 3 groups. CONCLUSIONS: Distal splenorenal shunt with splenopancreatic disconnection and gastric transection may reduce the incidence of postoperative hyperammonemia.

Comparison of Emory and Cedars-Sinai methods for assessment of left ventricular function from gated myocardial perfusion SPECT in patients with a small heart.

To evaluate the effect of left ventricular (LV) size on the calculation of LV function from gated myocardial SPECT with Emory and Cedars-Sinai programs, we performed 99mTc-tetrofosmin gated SPECT on 49 patients with ischemic heart disease. End-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) were semi-automatically calculated by each program. All patients underwent left ventriculography (LVG) within 3 months before and after the SPECT study. We grouped the patients into 22 with a calculated ESV obtained from LVG of over 50 ml (group A) and 27 with an ESV value of 50 ml or below (group B). We then compared the ESV values from gated SPECT with those from LVG in each group. In group A, the ESV from both Emory and Cedars-Sinai programs similarly correlated well with those from LVG (r = 0.92 and r = 0.93, respectively), but in group B, the ESV calculated from the Cedars-Sinai program correlated less with those from LVG (r = 0.53) than those from the Emory program did (r = 0.70). The calculated LV volumes had more errors in the Cedars-Sinai program than in the Emory program, when a patient had a small heart.

Simultaneous assessment of Tc-99m-sestamibi and I-123-BMIPP myocardial distribution in patients with myocardial infarction: evaluation of left ventricular function with ECG-gated myocardial SPECT.

123I-labeled 15-(p-iodophenyl)-3R,S-methyl pentadecanoic acid (BMIPP) is a branched-chain free fatty acid that is used to evaluate various cardiac diseases. The aim of the present study was to investigate the relationship between myocardial perfusion (99mTc-sestamibi) and BMIPP uptake, and to correlate perfusion and metabolic alterations with regional left ventricular dysfunction in patients with myocardial infarction (MI). ECG-gated dual-isotope myocardial SPECT was performed on 130 patients with MI with sestamibi (555 MBq) and BMIPP (148 MBq). The patients were classified into 3 groups according to PTCA therapy and the interval between the onset of infarction and RI injection (OR time). Group A (n = 56) included patients whose OR time was less than one month and who had undergone successful PTCA, Group B (n = 36) had OR times of less than one month and had conservative medical therapy, and Group C (n = 38) had OR times of over one month. The severity scores of the dual-isotope images were calculated from the defect scores in 9 segments. From the ECG-gated SPECT data with sestamibi, the left ventricular ejection fraction (LVEF; %) and regional wall motion were determined automatically using the QGS program LVEF obtained from gated SPECT correlated well with the severity scores for sestamibi and BMIPP (r = -0.68 and -0.76, respectively). The delta severity scores (BMIPP scores - sestamibi scores) of Group A were significantly higher than those of the other two groups (3.6 +/- 3.0 vs. 1.5 +/- 1.7 and 1.0 +/- 1.4, p < 0.001 ). The rate of dysfunctional segments with normal sestamihi distribution was significantly higher in Group A than in Group C (20.7% vs. 6.7%, p < 0.001). ECG-gated dual-isotope SPECT is useful since myocardial perfusion, fatty acid metabolism and left ventricular function can be analyzed during a single examination, so that this procedure has the potential to provide comprehensive information when evaluating patients with ischemic heart disease.

Increased bone mineral turnover without increased glucose utilization in sclerotic and hyperplastic change in fibrous dysplasia.

Fibrous dysplasia is a benign bone disorder. It is diagnosed by distinctive X-ray radiography, CT, and MRI findings. Although bone scintigraphy helps to identify the tumor origin according to accelerated bone turnover, the glucose metabolism in fibrous dysplasia has not yet been investigated. We reported a case of fibrous dysplasia in craniofacial bone which showed signs of the acceleration of bone mineral turnover without elevated glucose utilization by Technetium-99m-HMDP SPECT and Fluorine-18-FDG PET. We concluded that the growth of fibrous dysplasia needed the acceleration of bone mineral turnover without an increase in glucose metabolism.

Effects of dietary restriction on cellular immunity in rats.

Phagocytosis of opsonized sheep red blood cells (SRBC) by alveolar macrophages (AM) was measured in rats fasted for 1 to 9 days or fed on diets restricted 20 to 95% compared to control group for 2 and 8 weeks. In rats fasted for 1 to 6 days, AM showed an increased phagocytosis at 2 days after fasting, but their phagocytic activity remarkably decreased afterwards. Furthermore, phagocytic activity of AM per rat revealed much more decrease at 3 to 6 days after fasting. Then the production of interleukin-1 (IL-1) by AM increased with prolonged fasting, but the production of prostaglandin E2 (PGE2) by AM cultured with lipopolysaccharide (LPS) conversely decreased in rats fasted for 2 days or longer. The proliferation of splenocytes increased with prolonged fasting. On the other hand, 20 to 95% restricted diets induced the increased phagocytosis of AM with prolonged experimental period. However, phagocytic activity of AM per rat showed significant increase only in rats on a 40% restricted diet. The findings suggest that differences in both duration and degree of dietary restriction modulate phagocytic function of AM, and may contribute to explaining, in part, conflicting observations which have been obtained on the immunologic state in malnourished animals.