THE ORIGIN OF THE LEPRA CELL

1. By means of the method of vital staining it is found that the lepra cell in rat leprosy is derived from the histiocyte. 2. From the similarity in morphology and function of the lepra cells in this condition and those of human leprosy, it seems likely that derivation of the cells in the two conditions is similar.

THE INFLUENCE OF ELECTROLYTES ON THE STABILITY OF RED BLOOD CORPUSCLE SUSPENSIONS

Two types of stability are observed in suspensions of red blood cells. In weak concentrations of electrolytes the stability depends on the electric charge of the cells and suspension is unstable below a certain critical P.D. In strong concentrations of electrolyte, the stability bears no relation to the charge.

EXPERIMENTAL NEPHRITIS IN THE FROG : I. THE ANATOMICAL EVIDENCE OF DAMAGE

1. The damage produced by corrosive sublimate, potassium bichromate and uranium nitrate in the frog's kidney is described. 2. The morphological lesions consist of evidences of tubular damage, such as regressive changes in the epithelium, and of damage to the glomeruli ranging from increase in their permeability to gross damage of and hemorrhage from the tuft. 3. The point is emphasized that these lesions differ in their degree rather than in their nature from those found in the mammalian kidney after the administration of the same poisons. 4. The frog's kidney is exceptionally well suited therefore for the study of lesions which though present are masked in the complexities of structure and function of the mammalian kidney.

EXPERIMENTAL NEPHRITIS IN THE FROG : IV. THE SIGNIFICANCE OF THE FUNCTIONAL RESPONSE TO VASCULAR AND TO PARENCHYMAL DISTURBANCES IN THE KIDNEY

A summary of our findings is briefly made. A functional examination of the kidneys did not allow any differentiation between the results of vascular and parenchymal damage. This was true, as is emphasized in the arrangement of Charts 1 and 2, in the case of both glomerular and tubular dysfunction for it is seen that the type of functional derangement is identical in the two types of damage. Anatomical examination of the kidneys on the other hand showed definite differences in the state of the kidneys in the two types of damage, whether the dysfunction was glomerular or tubular. Certain points should be emphasized here. First, the validity of these results is not dependent on any particular interpretation of the significance of the functional phenomena observed. Whatever the anatomical relations between the two circulations in the kidney, whether urea, salts, dyes or water is excreted by one mechanism or another, no matter what part "filtration" or "absorption" may play in the elaboration of the final urine, the fact remains that the status of the function of these kidneys was identical, no matter how its functional state came into being, when an anatomical examination showed their actual condition to be significantly different. The fact that vascular disturbances, if of sufficient duration may in turn produce parenchymal changes complicates the problem still further, for in lesions that spontaneously develop in the kidney the mixture of vascular and parenchymal disturbances is so intimate that the functional results become infinitely more difficult of interpretation. Our previous studies have shown that even in the controlled extravital experiment conditions and relations of functional and structural response may thus become exceedingly complex (2). These complications were purposely avoided in the present study, however, by making the period of vascular disturbance short. Also, and again for the purpose of simplification, the toxic agent which caused the parenchymal disturbances was used in low enough concentration to produce only the less complex of the structural alterations that may follow its contact with the cells. And for the same reasons the simplicity of the general conditions existing in the perfusion experiments deserves special emphasis. Every element of the circulating fluid that is going to the kidneys is known and may be varied at will. Every constituent of the urine formed from this fluid can be accurately determined and compared with its condition in the circulating fluid. We have given in our experiments only rates of excretion but "concentration factors," "ratios," "clearances" or any other formulae might be calculated, without altering the conclusion that the functional status of the organs in the two types of damage, vascular and parenchymal, was identical. All these contrasts between the simplicity of our experiments and the complexity that must obtain when the problem is investigated in the living animal, particularly if mammals are used whose renal activity is only partially understood, add considerable weight to the conclusion that functional examination is unable to differentiate between two types of damage of very different significance, the one vascular, transient and reversible, the other parenchymal, permanent and, as far as the cells involved are concerned, irreparable. It might seem that a similar result is the proper conclusion to be drawn from the long series of similar attempts by clinical and experimental study to determine the condition of the kidneys from functional examinations. But it has been and apparently still is hoped, perhaps because in such examinations relations are so complex and involved that nothing seems beyond hope, that some refinement in method or the use of some selectively excreted substance, such as a dye or other foreign substance, may distinguish between the two conditions of vascular and parenchymal disturbance. The answer of our experiments is that the apparent similarity in the findings of the functional tests in the two cases is in fact an identity in the functional state in the two conditions though produced by different mechanisms; and there remains no reason to suppose that any procedure could distinguish between differences that in fact do not exist. The observation of the anatomical changes in the kidneys of our experiments allowed on the other hand a ready determination of the significance of the alteration that existed in the two conditions of damage, since the fate of the organ could be predicted directly from the structural alterations observed. In our experiments the observations were made by histological means; other methods which have been shown by postmortem pathological evidence to be valid and to give similar information, are however available (7). A final point in these experiments may be emphasized, well known perhaps, but often insufficiently appreciated, namely, a weakness in the anatomical approach to the problem. The morphologist is unable to describe even roughly the functional state of a kidney from its histological appearance. In certain cases of frank damage he may hazard a precarious guess, but severe functional disturbances may exist without any trace of structural derangement that can be seen by the eye. For all we know the converse may be true. And if such is the case in the simple and controlled conditions of our experiments, how can one venture to speculate on the significance or functional effects of inflamed glomeruli, abnormal tubules and sclerosed vessels as explaining some complicated clinical observation, the exact physiological basis of which is indeed unknown? Until the fundamental correlation of the two aspects of damage, functional derangement and structural change, has been made the whole problem of the abnormal kidney must remain not only unsolved but unsolvable.

MECHANISM OF UREA EXCRETION

1. Urea is present in the cells of the proximal convoluted tubule in a concentration higher than that of the blood or than that of the cells of any of the other kidney tubules. 2. Such a condition can only be reconciled to an assumption of an active secretion (excretion) on the part of these cells. 3. Urea also passes through the glomerular filter with the other crystalloids of the blood plasma. 4. The final concentration of urea is due to the above mentioned secretion by the proximal convoluted tubule, and to the absorption of water in other parts of the tubule.

A FUNCTIONAL AND ANATOMICAL STUDY OF THE EXCRETION OF HEMOGLOBIN BY THE KIDNEY

1. The anatomical and functional findings in hemoglobin excretion are best explained by the assumption of a filtration of this substance through the glomerulus and an additional excretion of it by the tubule cells. 2. Absorption of water aids in the concentrating process, and is most marked in the collecting tubules.

A COMPARISON OF THE MANNER OF EXCRETION OF NEUTRAL RED AND PHENOL RED BY THE FROG'S KIDNEY

1. Phenol red and neutral red are excreted by the perfused frog's kidney by different routes. 2. Phenol red is excreted chiefly through the glomerulus, neutral red through the tubules. 3. Some slight excretion of each of these dyes by the converse mechanism is possible, though there is no evidence in our experiments that necessitates such a conclusion. 4. The importance of methods leading to the production of a normal volume of urine by the perfused kidney is emphasized.

A COMPARISON OF THE METHOD OF EXCRETION OF NEUTRAL RED AND PHENOL RED BY THE MAMMALIAN KIDNEY

A direct examination with the method of perfusion of the excretion by the frog's kidney of phenol red and neutral red has shown that the dyes are eliminated in different manners as a result of different mechanisms. The former is excreted in much the greater part by the glomeruli; the latter by the tubules. Urea is excreted in a manner similar to phenol red. The indirect examination of the function of the mammalian kidney by means of excretion ratios has shown a like contrast between the manner of elimination of the two dyes, and here again was found a similarity in the manner of excretion of phenol red and urea. This would seem to be as close an examination as can be made with our present methods of experimentation of the question of the mechanism of the excretion of these substances by mammals. As the facts stand they constitute strong presumptive evidence that in mammals and amphibia the like results have arisen from like causes, phenol red and urea being eliminated chiefly through the glomeruli in both instances while neutral red is excreted principally through the tubules.

EXPERIMENTS ON THE PRODUCTION OF SPECIFIC ANTISERA FOR INFECTIONS OF UNKNOWN CAUSE : III. NEPHROTOXINS: THEIR SPECIFICITY AS DEMONSTRATED BY THE METHOD OF SELECTIVE ABSORPTION

As Pearce has shown, a serum highly injurious to the kidney of dogs can be produced by the immunization of rabbits with washed renal tissue of the dog. The histological findings are striking and characteristic, the most noteworthy being a glomerular lesion of special type. The renal changes differ much from those Pearce described. The injury to the kidney is not to be explained by hemolytic and hemagglutinative elements in the serum. The complete removal of such antibodies by exhaustion of the serum with successive portions of red cells fails to lessen materially its ability to cause kidney lesions. Furthermore, an ordinary hemolytic and hemagglutinative serum produced by the use of washed red cells as antigen fails to cause similar lesions. The distinctive, injurious principle of antikidney serum can be removed and the latter rendered innocuous by absorption with kidney tissue. To all practical intents and purposes it would seem that nephrotoxic serum of. the sort here described is specific. If infected tissue is to be utilized as an antigen for the production of therapeutic antisera the latter must in some instances be exhausted with tissue of the same sort prior to introduction into the animal body.

Identification of bloodmeals in Anopheles quadrimaculatus and Anopheles punctipennis from eastern equine encephalitis virus foci in northeastern U.S.A

The host-feeding patterns of Anopheles quadrimaculatus Say and Anopheles punctipennis (Say) were examined in order to evaluate their potential contributions to the transmission of eastern equine encephalitis virus (EEEv) and other arboviruses in the northeastern U.S.A. Engorged mosquitoes of the two species were collected from EEEv foci in central New York (NY) and throughout New Jersey (NJ), and their bloodmeals were identified using a polymerase chain reaction (PCR)-based assay and sequencing portions of the mitochondrial cytochrome b gene. Analysis of 131 An. quadrimaculatus and 107 An. punctipennis from NY revealed that 97.7% and 97.2%, respectively, had acquired blood solely from mammalian hosts. Similarly, examination of 288 An. quadrimaculatus and 127 An. punctipennis from NJ showed 100% and 96.0%, respectively, contained mammalian-derived bloodmeals. Mosquitoes containing mixed bloodmeals from both avian and mammalian hosts were detected in 1.6% of An. quadrimaculatus from NY, and 2.8% and 4.0% of An. punctipennis from NY and NJ, respectively. White-tailed deer (Odocoileus virginianus) constituted the most common vertebrate host for these anopheline mosquitoes, accounting for 85.8-97.7% of all bloodmeals identified. The predominance of white-tailed deer as a source of bloodmeals supports enzootic amplification of deer-associated arboviruses in this region, including Jamestown Canyon, Cache Valley and Potosi viruses. One horse- and two human-derived bloodmeals were also detected in An. quadrimaculatus collected in NJ. Limited avian-derived bloodmeals were detected from mourning dove (Zenaida macroura), sharp-shinned hawk (Accipiter striatus) and house finch (Carpodacus mexicanus), mostly in mixed bloodmeals. Occasional feeding on avian hosts suggests that these mosquitoes may participate as epizootic-epidemic bridge vectors of EEEv from viraemic birds to mammalian hosts of concern, including horses and humans. An isolate of EEEv was recovered from the head and thorax of an An. punctipennis mosquito collected in NY.

Association of ATG16L1 and IRGM genes polymorphisms with inflammatory bowel disease: a meta-analysis approach

The aim of this study was to determine the role of the ATG16L1 (rs2241880) and IRGM (rs13361189 and rs4958847) genes polymorphism in Crohn's disease (CD) and ulcerative colitis (UC). Our study included 557 CD and 425 UC patients and 672 ethnically matched Spanish controls and a meta-analysis with the data published to date. The polymorphisms were genotyped using predesigned TaqMan single nucleotide polymorphism genotyping assays. There was a statistically significant difference in the distribution of the ATG16L1 rs2241880 G allele between CD patients and controls in the Spanish population: P=6.5 x 10(-9), odds ratio (OR)=1.62. Although no differences were observed between UC patients and controls in the Spanish cohort, a meta-analysis demonstrated that the ATG16L1 G allele increase significantly risk for UC (P=0.0003, pooled OR=1.08). In addition, our meta-analysis data showed that IRGM rs13361189 and rs4958847 polymorphisms were associated with CD (rs13361189 C allele P=1.07 x 10(-19), pooled OR=1.34; rs4958847 A allele P=2.78 x 10(-17), pooled OR=1.31) and UC (rs13361189 P=0.0069, pooled OR=1.16; rs4958847 P=0.014, pooled OR=1.13). In conclusion, our results confirm the ATG16L1 rs2241880 and IRGM rs13361189 and rs4958847 polymorphisms as important markers for CD susceptibility and indicate that these variants are also associated with UC.

Results of a phase II trial of single-agent amrubicin (AMR) in patients with extensive disease small cell lung cancer (ED-SCLC) refractory to first-line platinum-based chemotherapy: An update

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Background: Amrubicin (AMR), a third-generation synthetic anthracycline and potent topoisomerase II inhibitor, is approved in Japan for the treatment of lung cancer. Patients (pts) with SCLC, who are refractory to first-line chemotherapy or progress within 3 months (mos) of treatment completion, are less likely to respond to additional chemotherapy and have an expected median survival of 3–5 mos. Here, we investigate the efficacy and safety of single-agent AMR in the treatment of Western pts with refractory ED-SCLC. Methods: In this phase II trial, pts with ED-SCLC refractory to prior 1st-line platinum-based chemotherapy (defined as progression (PD) while on therapy or relapse within 90 days of treatment completion) and ECOG performance status (PS) ≤2 were eligible. Patients were treated with intravenous AMR 40 mg/m2/day x 3 days every 21 days until PD or intolerable toxicity. The primary endpoint was response rate (ORR, by RECIST), with a goal to demonstrate an ORR ≥18% (point estimate). Secondary endpoints included progression-free survival (PFS) and overall survival (OS). Results: In all, 75 pts were enrolled with a median age of 63 years (range 43–88), 52% female, 17% PS 2. Response to 1st-line therapy was 5% complete remission (CR), 36% partial remission (PR) and 28% PD. Median time from completion of 1st-line therapy to PD was 1.3 mos. Sixty-nine pts received AMR for a median of 4 cycles (range 1–12). Six pts died or discontinued before receiving treatment. The primary endpoint was met with an ORR of 21% (16/75, 95% confidence interval [CI] 13.6% - 31.9%), including CR in 1 pt (1%) and PR in 15 pts (20%). Stable disease was achieved in 40% of pts. Two pts with PD as best response to 1st line chemotherapy achieved a PR. Median OS was 6.0 mos (95% CI 4.8–7.1 mos). Median PFS was 3.2 mos (95% CI 2.4–4.0 mos). The most common grade 3 or 4 adverse events were neutropenia (65%), thrombocytopenia (39%), and leukopenia (35%). Seven (10%) patients experienced febrile neutropenia. Dose reductions were required in 26 patients (38%). Conclusions: AMR shows promising activity, with an ORR of 21%, and an acceptable safety profile in patients with refractory ED-SCLC, and warrants further study in these pts.

[Table: see text]

Amrubicin (AMR) and cardiotoxicity in second-line treatment of small cell lung cancer (SCLC): A pooled analysis of left ventricular ejection fraction (LVEF) in two phase II trials

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Background: Amrubicin (AMR) is a third-generation synthetic anthracycline and a potent topoisomerase II inhibitor approved in Japan for the treatment of lung cancer. In Japanese pre and postmarking studies, AMR treatment was not associated with cardiotoxicity. The purpose of this analysis was to determine if AMR treatment of Western patients (pts) is associated with anthracycline-induced cardiomyopathy. Methods: To evaluate risk of cardiomyopathy, LVEF was measured by echocardiogram or by multiple gated acquisition (MUGA) scan and pooled from pts enrolled in 2 trials of IV AMR, 40 mg/m2/day x 3 days q 21 days for second-line treatment of sensitive or refractory SCLC. Pts with measurable disease, ECOG PS 0–2, LVEF ≥50%, and prior platinum-based treatment were assessed at baseline (BL), cycles 3, 6, then every 2 cycles, and end of treatment. Pts were to be assessed by the same method (ECHO or MUGA) throughout the study. Pts with a persistent ≥20% decrease in LVEF during treatment were to be removed from the study. Results: 112 patients were treated (sensitive n=43, median 6 cycles; refractory, n=69, median 5 cycles) and had at least 1 LVEF assessment. Median age was 63 years and median BL LVEF was 60%. Changes in LVEF from baseline were minimal ( Table ) and similar across cumulative dosing groups including 15 pts who received a cumulative dose of >1,000 mg/m2 AMR. Two refractory pts (1.8%) experienced drops in LVEF >20%. One had BL LVEF of 85%, then 60% at cycle 3, and 70% subsequently with ongoing therapy. The second, with a history of cardiomegaly, had LVEF of 55% at BL, cycle 3, and 5 by ECHO, and 29% at the time of progression after cycle 9 (cumulative AMR dose 840 mg/m2) by MUGA. The patient died due to progressive disease with no evidence of CHF. Conclusions: In this pooled analysis of SCLC pts, LVEF remained stable even in pts with cumulative AMR dosing >1,000 mg/m2. AMR for second-line treatment of SCLC does not appear to cause anthracycline-related cardiomyopathy.

[Table: see text]

[Table: see text]

Gender-dependent differences in serum profiles of insulin and leptin in caloric restricted rats

In the present study, we have investigated whether differences between male and female rats described in response to 40% caloric restriction (CR) were influenced by circulating level variations of sex hormones and/or insulin and leptin. Body weights (BW), organ weights, and adipose depot weights (ADW) were also measured. The most affected tissues by CR were the fat depots. Metabolically active organs were the least affected, especially more in females than in males (male weight lost: 24.3% vs. female: 17.3%). Testosterone and estradiol circulating levels did not show changes by CR. Insulin levels were decreased by CR in both genders, but was more evident in female rats than males. Leptin serum levels were higher in male rats than in females, and CR caused a circulating leptin level reduction only in males. In conclusion, our results indicate that leptin and insulin could be one of the keys of the different hormonal control of energy homeostasis in response to CR between female and male rats. In this sense, leptin serum levels correlated statistically with BW and with individual ADW only in male rats, whereas insulin serum levels correlated statistically with BW and with any of the ADW studied only in females.

Sexual dimorphism in liver mitochondrial oxidative capacity is conserved under caloric restriction conditions

Caloric restriction (CR) without malnutrition has been shown to increase maximal life span and delay the rate of aging in a wide range of species. It has been proposed that reduction in energy expenditure and oxidative damage may explain the life-extending effect of CR. Sex-related differences also have been shown to influence longevity and energy expenditure in many mammalian species. The aim of the present study was to determine the sex-related differences in rat liver mitochondrial machinery, bioenergetics, and oxidative balance in response to short-term CR. Mitochondria were isolated from 6-mo-old male and female Wistar rats fed ad libitum or subjected to 40% CR for 3 mo. Mitochondrial O2 consumption, activities of the oxidative phosphorylation system (complexes I, III, IV, and V), antioxidative activities [MnSOD, glutathione peroxidase (GPx)], mitochondrial DNA and protein content, mitochondrial H2O2 production, and markers of oxidative damage, as well as cytochrome C oxidase and mitochondrial transcription factor A levels, were measured. Female rats showed a higher oxidative capacity and GPx activity than males. This sexual dimorphism was not modified by CR. Restricted rats showed slightly increased oxygen consumption, complex III activity, and GPx antioxidant activity together with lower levels of oxidative damage. In conclusion, the sexual dimorphism in liver mitochondrial oxidative capacity was unaffected by CR, with females showing higher mitochondrial functionality and ROS protection than males.