Sequential chemical modification of a histidyl and a cysteinyl residue in bacterial luciferase.

Sequential modification of two amino acid residues (a histidyl and a cysteinyl residue), both essential for the enzymatic function of bacterial luciferase from Beneckea harveyi, has been conducted to determine if the inactivation arising from the chemical modification of either of these residues is due to a conformational change. This experimental approach has shown that modification of the histidyl or cysteinyl residue did not affect the reactivity of the remaining 'essential' residue, suggesting that chemical modification had not caused a change in conformation. Furthermore, since substrates protect luciferase against inactivation due to modification of either of these residues, it was possible to determine if the initial modification of the histidyl or cysteinyl residue prevented substrate binding by conducting the modification of the remaining residue (i.e., the cysteinyl or histidyl residue, respectively) in the presence of substrates. The results have shown that after modification of the histidyl residue substrates no longer protected the cysteinyl residue against modification, whereas after modification of the cysteinyl residue substrates still protected the histidyl residue against modification. These results have provided evidence that the histidyl residue and not the cysteinyl residue of luciferase is essential for the binding of substrates in the bacterial bioluminescent reaction.


An essential arginine residue in the active-site pocket of glycogen phosporylase.

Phosphorylases a and b (EC 2.4.1.1) were inactivated by selective modification of arginyl residues on reaction with 2,3-butanedione in sodium borate buffer. The rate of inactivation was slightly greater for phosphorylase a than b. The course of inactivation followed pseudo-first-order kinetics with some deviations at low rates or at more than 60% inactivation. The rate of inactivation was first order with respect to butanedione concentration. The inactivation was partially reversible, and ultracentrifugal studies showed no change in subunit association or dissociation. Amino acid analyses indicated that several arginines were modified during inactivation and that no other amino acid was affected. Protection from inactivation was provided by the substrate glucose 1-phosphate (G1P), alone or together with the allosteric activator AMP, as well as by the competitive inhibitor UDP-glucose. The rate of inactivation of phosphorylase b was also retarded by the presence of AMP alone. Glycogen did not have any appreciable effect on inactivation. The Km of G1P for phosphorylase a remained constant over the course of inactivation, while the Km values of G1P and AMP for phosphorylase b increased. The modification of cross-linked tetragonal microcrystals of phosphorylase a followed the same trend as the enzyme in solution, although the rate of inactivation was slower. The X-ray crystallography studies at 6 A (1 A = 0.1 nm) resolution, of butanedione-treated cross-linked tetragonal crystals of phosphorylase a showed a large new peak of electron density at the end of a long side chain in the active-site pocket. The substrates G1P and arsenate, as well as UDP-glucose, had previously been shown to bind in that location. Other, small peaks of electron density were found in locations on the outside of the protein molecule. UDP-glucose failed to bind to the active site of crystals which had been treated with butanedione, while AMP, which also binds in the active-site pocket, showed a lower occupancy. This work indicates the presence of a functional arginine residue at the binding site for G1P in glycogen phosphorylases a and b.


The inhibition by substrate analogues of gamma-aminobutyrate aminotransferase from mitochondria of different subcellular fractions of rat brain.

Cytoplasmic-mitochondria-enriched and synaptosome-enriched subcellular fractions were prepared from rat brain to study certain kinetic properties of gamma-aminobutyrate: alpha-oxoglutarate aminotransferase (GABA-T) (EC 2.6.1.19) from each of the sources. From this study two differences emerged. Firstly, the cytoplasmic enzyme exhibited an eightfold greater affinity for gamma-aminobutyric acid (GABA) than did the synaptosomal GABA-T; the Km being 6.5 mM and 53 mM, respectively. Secondly, synaptosomal GABA-T is comparatively more susceptible to inhibition by the substrate analogues 2,4-diaminobutyric acid (DABA) and aminooxyacetic acid (AOAA) than is the enzyme from the cytoplasmic mitochondrial fraction. In each case the inhibition was of a competitive nature with respect to GABA. The Ki for the DABA was 13 mM for the cytoplasmic-derived enzyme and 8mM for the synaptosomal enzyme. With AOAA the Ki was 0.1 muM and 0.06 muM for the synaptosomal and cytoplasmic mitochondrial enzyme, respectively. These results provide further evidence that GABA-T from cytoplasmic mitochondria is different in several respects from the enzyme found in synaptosomes.


Effect of ribonucleotides on substrate availability for DNA polymerase assays in cytoplasmic fractions of rat intestinal mucosa.

The deoxyribonucleoside triphosphate substrates for DNA synthesis were hydrolysed during the DNA polymerase (EC 2.7.7.7) assay with cytoplasmic subcellular fractions of rat intestinal mucosa. Presumably because of phosphatase (EC 3.1.3.2) activity in these fractions, inorganic phosphate was liberated from the nucleotides, and radioactive thymidine triphosphate was shown to be degraded to thymidine di-and mono-phosphate, thymidine, and thymine. Addition of ATP to the postmicrosomal supernatant increased its DNA polymerase activity by sparing the deoxyribonucleotide precursors from enzymatic degradation.


Surgical treatment for pulmonary emphysema.

Three in-vivo observations stimulated interest in surgical treatment for emphysema: (a) the destructive changes are rarely generalized, (b) the central portions of the lungs are frequently less seriously affected, and (c) marginal folding produces obstructive change in the more normal lung tissue. If destroyed avascular space-occupying areas can be removed, the compressed lung tissue may be stretched to fill pleural space in a functionally effective fashion. Residual elastic tissue will them maintain patency of terminal bronchioles. Preoperatively the extent of the destructive change can be defined most accurately by pulmonary angiography, and zones of functioning capilary circulation can be identified. Forty-seven patients with multifocal space-occupying emphysematous change have been treated surgically. The postoperative mortality was 21% but worthwhile long-term improvement has been obtained in 45% of patients presenting with disabling dyspnea. In these patients, surgical treatment warrants consideration if significant space occupation accompanies the bullous disease, provided alveolar vascularization can be demonstrated in the compressed adjacent normal lung tissue. Limited resections that preserve all vascularized and potentially functioning lung tissue are preferable. It is essential that obliteration of the hemithorax be obtained promptly in view of the high incidence of postoperative complications requiring secondary operative procedures, if 'leaks' and residual spaces are allowed to persist. Postoperative care in a respiratory intensive care unit is mandatory.


Comparison of cryotherapy and surgery for treatment of spontaneous mouse tumour.

Spontaneous mammary adenocarcinoma was implanted subcutaneously into the flank or leg of inbred C3H/HeJ mice. Excision or cryotherapy of flank tumours was followed by cure in 47 and 52% respectively. Amputation or cryotherapy of tumours of the hind leg resulted in a cure in 70% for each method. Rechallenge of surviving mice resulted in initial delay of growth in mice treated by cryotherapy, but final host acceptance and survival were the same for each method of treatment. The tumour was grown in tissue culture; significant antibody levels after cryotherapy could not be detected by a mixed antiglobulin technique. It is concluded that cryotherapy can destroy the tumour, but this method offers little immunologic advance for weakly antigenic tumours. Careful monitoring of temperature is essential for successful cryotherapy. In the same series of experiments barbiturate anesthesia and tumour exploration did not alter tumour growth or mortality.


Preoperative hair removal.

This study compares the efficiency, safety and cost of hair removal before surgery, with a safety razor, an electric clipper and a depilatory. It was found that both the razor and the clipper damaged the surface of the skin, while the depilatory caused a mild lymphocytic reaction in the upper dermis. The depilatory was expensive and may cause sensitivity reactions in a few individuals, but was found to be the easiest and most efficient method of removing hair. It was concluded that if hair has to be removed a depilatory is the agent of choice.


The health of the very aged.

Little information is available on the health status of persons 85 years or over. Recent United States data indicate that 20% of individuals 85 years of age or over reside in nursing and personal care homes and that among these institutional residents 31% are bedfast, 11% are chairfast and 71% manifest evidence of senility. An investigation into the health of persons 85 years of age or over in two Ontario counties revealed that 39% resided in long-stay institutions, and that one of the main differences between old people living independently in the community and those in institutions was the higher proportion of the latter needing help with the activities of daily living and showing mental disorientation. Of those individuals 85 years of age or over in institutions for 1 year, 26% acknowledged often feeling depressed and 18% acknowledged often wishing they were dead, but these tendencies were not more frequent in those 85 years of age or over than in those 65 to 84 years of age. These findings have implications for service and research needs and attitudes towards death.


Vascular involvement in relapsing polychondritis.

Review of four cases of relapsing polychondritis (RP) seen at one hospital in the 12-year period 1963 to 1974 revealed that one patient had aortic insufficiency with large artery involvement, two others had involvement of medium and large arteries and the fourth may have had mucocutaneous vasculitis. Valvular disease has occurred in 9% of all cases of RP reported in the literature and, if vasculitis beyong the aortic root is included, 25% of cases of RP manifested inflammatory vascular disease. The frequency of pseudotumour of the orbit and cochlear-labyrinthine dysfunction is also high and may be a manifestation of vasculitis.


[Health services priorities in Quebec].

The reform of health services in Quebec, of which the most important stage was the creation of the Department of Social Affairs and the Quebec Health Insurance Board, has solved certain problems such as the inaccessibility to care because of the cost, the paucity of medical personnel and the excessive increase in the cost of the services offered to hospital patients. A critical analysis of both the reform and its practical consequences points to certain conclusions which, far from rejecting the principle of the reform, indicate none the less various possibilities for reorienting its priorities. Observing the rate of recourse to health services as well as the attitudes and conduct of health professionals have helped us to identify the causes of certain tendencies inspired by the incentives inherent in the reform. The organization of health services in Quebec must be oriented toward new priorities: the prevention and treatment both of environmental diseases and diseases associated with ageing plus the definition of a global approach to public health.


Direct leukocyte migration inhibition by myelin basic protein in exacerbations of multiple sclerosis.

Studies in 13 normal subjects, 9 patients with multiple sclerosis (MS) within 3 weeks of exacerbation and 16 others 1 to 6 months after onset were carried out for evidence of cell-mediated hypersensitivity to myelin basic protein. Ten patients with stroke and 10 with Guillain-Barré syndrome were studied as additional controls. Peripheral leukocytes obtained by leukapheresis were packed into capillary tubes and allowed to migrate out onto glass in the presence or absence of myelin basic protein. Cells of patients within 3 weeks of an MS episode gave a mean migration index of 68 +/- 9%, and those 1 to 6 months after onset, 93 +/- 21%. For the entire MS group the mean index was 88 +/- 20%, for those with Guillain-Barré, 103 +/- 7%; and for the stroke patients, 107 +/- 11%. Results for the acutely ill MS patients were significant (P less than 0.005). The data are similar to those obtained using the migration inhibition factor assay but show that sensitized lymphocytes also elaborate a second mediator during acute exacerbations of illness. These observations strengthen evidence that sensitization to this potent encephalitogen occurs simultaneously with exacerbations of clinical illness.


Cyclophosphamide, vinblastine, procarbazine and prednisone with CCNU and vinblastine maintenance for advanced Hodgkin's disease.

Fifty patients with advanced Hodgkin's disease were treated with a combination of cyclophosphamide, vinblastine, procarbazine and prednisone (CVPP) in a 21-day cyclic regimen. Thirty-one patients (62%) achieved a pathologically documented complete remission (CR). Of the 23 previously untreated patients, 13 obtained CR. Twenty-seven patients had been previously treated and 15/19 (79%) of those with prior major radiation therapy and 3/8 (37.5%) of those who had received both irradiation and chemotherapy achieved CR. Sixteen of the patients who attained CR received maintenance therapy with monthly alternating CCNU and vinblastine but as of this report, neither remission duration nor survival is significantly prolonged when compared to the 14 patients followed in remission on no therapy. Patients who received more than six courses of induction therapy (median 9.5, range 8-12) have had significantly fewer relapses and longer remissions than have those patients who received only six courses of therapy. It is concluded that: 1) CVPP is an effective regimen at inducing CR in patients with advanced Hodgkin's disease and has less gastrointestinal and neurologic toxicity than MOPP; 2) maintenance therapy with CCNU and vinblastine to date has not been beneficial; and 3) greater than six courses of induction chemotherapy prolongs remission duration and is associated with fewer disease relapses.


Significance of quantitative assessment of estrogen receptors for endocrine therapy in advanced breast cancer.

The predictive significance of quantitative assessment of estrogen receptors in tumor tissue was analyzed in women with advanced breast carcinoma. Receptor concentration was measured by the 3H-estradiol binding capacity of the cytosol fraction of biopsies taken before initiation of the treatment. The E. O. R. T. C. criteria for the assessment of the patients' response were used. In a total of 34 assessments, 25 biopsies contained receptors; the remaining ones were negative. Objective remission to various endocrine therapies was recorded in only eight of the receptor-positive patients. Responses occurred along the whole scale of receptor concentrations with an apparent crowding in the region of the higher values. Linear logistic regression analysis revealed that among 12 variables of known prognostic value, receptor concentration was the most significant in relation to therapeutic response. Other significant variables were bone involvement and age. Computations yielded formulas that are presented in graph form and provide an estimate of the probability of a given patient to respond to endocrine treatments. On the other hand, the results suggest that all patients are possibly hormone dependent, although to variable degrees. The latter concept has very definite therapeutic implications.


Conventional mammography, physical examination, thermography and xeroradiography in the detection of breast cancer.

From July 1, 1973, through January 15, 1975, at the Emory University Clinic independent physical examinations, conventional mammography, thermography and xeroradiography of the breast were carried out on 1,003 symptomatic patients by both physicians and radiologic technologists. One year after completion of the study there had been 360 breasts biopsied with 53 malignant and 307 benign lesions demonstrated. Seventy-three percent of the cancers were histologically Stage 0 or Stage I. The detection rate of the cancers by physician and technologist respectively were: 1) conventional mammography 87 and 74%; 2) xeroradiography 65 and 46%; 3) physical examination 62 and 51%; and 4) thermography 29 and 27%. In non-malignant breasts the physician and technologist designated cancer respectively in: 1) thermography 4 and 6%; 2) conventional mammography 6 and 6%; 3) xeroradiography 8 and 10%; and 4) physical examination 11 and 12%.


Retinoblastoma and intracranial malignancy.

The occurrence of independent brain tumors in two patients with retinoblastoma is described. One patient with well-differentiated biliteral retinoblastomas developed, over two years later, a pineal tumor but no other metastatic lesions. The pineal tumor was composed of small neuroblastic cells and a second population of larger cells with vesicular nuclei and more abundant cytoplasm. This feature is not characteristic of either primary or metastatic retinoblastoma. In the second patient the symptoms of a brain tumor led to the discovery of a small uniocular, well-differentiated retinoblastoma. The brain tumor was retrochiasmal, highly differentiated (showing areas of photoreceptor differentiation), and interpreted as an ectopic nonmetastatic retinoblastoma. The possible histogenetic origins of the brain tumors are discussed. Patients who develop symptoms of a brain tumor after a prolonged interval since the treatment of their ocular tumors should be suspected of harboring a second intracranial primary.


Malignant fibrous mesothelioma of the tunica vaginalis: a histologic and ultrastructural study.

An unusual malignant fibrous tumor of the testicular tunic in a 35-year-old Japanese man is presented. It apparently arose from the visceral layer of the tunica vaginalis where focal mesothelial hyperplasia was seen. Microscopically the tumor consisted of interlacing bundles of spindle cells and numerous polygonal cells with variable amounts of collagen fibers. The electron microscopic study demonstrated the former cell type closely resembling the fibroblast and the latter to be more epithelial having very plump cytoplasm with fairly well developed desmosomes. The tumor was diagnosed as malignant fibrous mesothelioma upon histopathologic and ultrastructural comparison with the similar tumors in the pleura and peritoneum. Because of the scarcity of the diagnosis in the region it is suggested that fibrous paratesticular tumors are critically reviewed.


Mesectodermal leiomyoma of the ciliary body: a tumor of presumed neural crest origin.

Two benign tumors of the ciliary body diagnosed as neurogenic tumors by light microscopy were shown by electron microscopy to be composed of smooth muscle cells with unusual morphologic features. The light-microscopic appearance of a background fibrillary matrix imparting a "neural" appearance was the result of the interweaving of myriad cell processes filled with thin cytoplasmic filaments possessing fusiform densities. The perikaryon of the tumor cells was relatively free of filaments and displayed mitochondria and stacks of rough-surfaced endoplasmic reticulum suggestive of Nissl substance. The basis for these remarkable "hybrid" tumor cells--combining myogenic and neurogenic characteristics--is believed to reside in the neural crest origin of the smooth muscle of the ciliary body (mesectoderm). The histogenetic implications of mesectodermal tissue and the tumors that it spawns are discussed.


Pleomorphic carcinoma of the pancreas: an analysis of 15 cases.

Pleomorphic carcinoma of the pancreas is a well defined histopathological entity characterized by non-cohesive, sarcoma-like growth pattern, and bizarre mono- and multinucleated tumor giant cells with abundant eosinophilic cytoplasm. Fifteen cases are identified in autopsy files of the Department of Pathology, Washington University School of Medicine, which represent 7.1% of all the non-endocrine pancreatic malignancies found at autopsy. Pleomorphic carcinoma is comparable to pancreatic adenocarcinoma in clinical features such as age, sex, and presenting symptoms except that it is more likely to occur in the body and tail of the pancreas, metastases invariably develop, hematogenous spread is more common, and the median survival is worse. Pleomorphic carcinoma could be distinguished from the pancreatic tumors that resemble giant cell tumor of the bone. Differential diagnostic features between it and amelanotic melanoma, hepatocellular carcinoma, choriocarcinoma, pleomorphic liposarcoma, pleomorphic rhabdomyosarcoma, fibroxanthosarcoma, poorly differentiated epidermoid carcinoma, and giant cell carcinomas of the lung and thyroid are discussed.


Estrogen receptor protein (ERP) in multiple tumor specimens from individual patients with breast cancer.

We have studied 29 patients from whom two or more spatially and temporally separate samples of breast carcinoma were obtained for ERP analysis. Differences in ERP were obtained in 24% of all cases studied. The greatest degree of variation was found when comparing a primary tumor with a subsequent metastasis (38%). Among eight patients with ERP negative (-) primary tumors, six had ERP (-) and two ERP positive (+) metastases. Among 11 patients with ERP (+) primaries eight had ERP (+) and three ERP (-) metastases. Variations were found in 20% of multiple nonsimultaneous metastases from individual patients. The difference in average interval between cases that did not show variation (9.6 months) and those that did vary (19.3 months) suggests that variation may be more likely to occur with later metastases. However, there was considerable overlap in the range of intervals. These findings underscore the need to biopsy readily accessible recurrences rather than to rely on the results of prior specimens. There was no apparent consistent relationship of these variations to age, site of specimen, interval between specimens or the histologic features of the tissues submitted for analysis. Two patients with an ERP (+) primary tumor had ERP (-) metastases after interval therapy. Similar variations were observed in patients who did not have interval therapy. The data do not perimit any definite conclusions as to the effect of chemotherapy or radiation on the ERP properties of mammary carcinoma.


Plasma ribonuclease: a marker for the detection of ovarian cancer.

There were no significant differences between the mean blood plasma (leukocyte-free) RNAase activity among 128 healthy women volunteers age 13-70 and 49 women with benign gynecological tumors. Exceptions to this finding were three apparently healthy women volunteers who had plasma enzyme activity which was higher than two standard deviations from the mean of the control subjects. Increased plasma RNAase activity was also demonstrated for 21 of 22 patients with ovarian carcinomas of differential histological types. This group included two patients with Stage IA, two patients with Stage IC ovarian carcinoma, and 17 patients with advanced ovarian carcinoma. The one exception was a patient with a well encapsulated, mucinous cystadenocarcinoma, Stage IA. The plasma RNAase activity returned to normal values in all of the cancer patients who had no clinical evidence of residual malignant tissue after surgical treatment. However, the enzyme activity also returned to a normal value in one of the 17 women in whom all of the malignant tissue was not removed. These data indicate that plasma RNAase activity can be utilized as a tumor marker for the presence of ovarian malignancies of various histological types, and to differentiate between malignant and benign neoplasms.


The epidemiology of colorectal polyps: prevalence in New Orleans and international comparisons.

Based on a study of the prevalence of intestinal polyps in New Orleans and on international comparisons, the following conclusions are reached. 1) There is a close parallelism in the epidemiology of colon cancer and adenomatous polyps. Both conditions are statistically associated with respect to geography, anatomic localization, socioeconomic class, migration experience and time trends. 2) The strength of the association favors the notion of a direct, positive correlation between multiplicity, size and atypia of polyps, and cancer risk, equivalent to "dose-effect". 3) The epidemiologic findings are coherent with other biologic facts derived from clinical, morphological and experimental studies. 4) Adenomatous polyps are a good epidemiologic indicator of colon cancer risk and their presence should be helpful in advancing from studies of the epidemiology of colon cancer to the epidemiology of precursor lesions.


Spontaneous streptococcus pneumonia peritonitis in a patient with metastatic gastric cancer: a case report and etiologic consideration.

Spontaneous peritonitis in adults has not been previously reported to occur in association with ascites of neoplastic origin. We report a patient with metastatic gastric adenocarcinoma in whom spontaneous streptococcus pneumonia peritonitis occurred as a terminal event. Massive metastases may have resulted in significant loss of the hepatic reticuloendothelial system and impaired the capability of the liver to function as an effective bacterial filter, predisposing the patient to bacterial peritonitis.


Stomach carcinoma among Hawaiians and Caucasians in Hawaii.

A review of Caucasian and Hawaiian patients with stomach carcinoma in Honolulu reinforces observations in other racial groups that the Lauren diffuse histopathological type of gastric cancer is more frequent in females and younger patients, while the so-called intestinal type is more common in older patients and men; that the intestinal form has a better prognosis; and that there are more long-term survivors among women than men with diffuse carcinoma. Prognosis and the level of cancer risk are not associated in Hawaii, since Hawaiians share high risk with Japanese and poor prognosis with Caucasians. There is no apparent association of cancer risk with the ratio of intestinal to diffuse forms among Hawaiians, Caucasians, and Japanese. In addition to the known high risk of stomach carcinoma in Hawaiians and Japanese, this study has identified a high risk among people of Portuguese ancestry.


Familial testicular cancer in a father (bilateral seminoma-embryonal cell carcinoma) and son (teratocarcinoma): a case report and review of the literature.

Familial testicular neoplasia is reported in a father and his son. This represents only the fifth published case of father-son testicular cancer. The father had bilateral testicular seminoma with embryonal cell elements while the son had teratocarcinoma. The clinical significance of familial testicular neoplasia is discussed and the subject of father and son testicular cancer is reviewed. This case of father-son testicular neoplasia illustrates the following important points: 1) there is a continuing need to document and describe each case of familial testicular cancer in order to better evaluate the pathogenesis of this familial occurrence; 2) prospective genetic and laboratory studies will be needed to definitively clarify the specific factors involved in the familial clustering or transmission of this type of cancer; and 3) this tendency for testicular cancer to affect multiple kindred must be considered in the proper guidance and counseling of affected patients and their high-risk family members.


Relative biochemical aspects of low and high doses of methotrexate in mice.

During low infusion rates of methotrexate (1.0 microng/hr/mouse; plateau plasma concentration, 2 X 10(-8) M), [3H]deoxyuridine incorporation into DNA was inhibited to a significant degree in small intestine and femur marrows. However, incorporation of [3H]thymidine into intestinal DNA was stimulated at this low infusion rate. During high infusion rates of methotrexate (10 microng/hr/mouse, plateau plasma concentration, 4 X 10(-7) M), inhibition of the incorporation of [3H]deoxyuridine at the steady state levels of plasma methotrexate in both the small intestine and femur marrow was significant. In contrast to stimulation at the low infusion rate, incorporation of [3H]thymidine into intestinal DNA at this high infusion rate was inhibited to a significant degree. Inhibition was not statistically significant in femur marrow DNA. The inhibition of [3H]thymidine into intestinal DNA could be reversed by the simultaneous infusion of inosine. Thus, in the in vivo system, an antipurine effect on DNA Synthesis at high methotrexate plasma concentration in the small intestine was observed. This antipurine effect was not apparent at the lower concentrations. The lower concentration, however, could still inhibit [3H]deoxyuridine incorporation into intestinal and femur marrow DNA to a significant enough degree that, if prolonged, it would resultin lethality to the mice. The thymineless state can be maintained for at most 60 hr in mice without lethal toxicity, whereas the antipurine state can be maintained for no longer than 18 hr in mice without some lethal toxicity. These data have important implications in rescue studies using thymidine or leucovorin.


DNA excision repair in ultraviolet-irradiated normal and malignantly transformed mouse epidermal cell cultures.

Pyrimidine dimer production and excision was studied in ultraviolet light (UV)-irradiated primary cultures of epidermal cells derived from perinatal mouse skin and in an in vitro malignantly transformed epidermal cell line. Dimer production increased linearly with UV dose level for both cell types. However, at any given UV dose level, there were 20% fewer thymine-containing dimers induced in the primary cultures compared to the transformed cell line. The reduced dimer yield in the primary cultures was attributed to the multilayer (three cell layers) of these cultures. The primary cultures were found to exicse no more than 10% of the original dimers in a 24-hr period, while the malignantly transformed cells excised 34%. Nonsemiconservative DNA repair synthesis was also studied as a function of dimer yields in the first 3 hr after irradiation. When the levels of repair replication in both cell types were compared at equal yields of UV-induced dimers, the malignantly transformed cells exhibited a higher level of repair than did the primary epidermal cells. There was no difference in the kinetics of repair replication between the two cell types at a UV dose level of 10 J/sq m over the first 6 hr after irradiation.


The interaction between radiation and adriamycin damage in mammalian cells.

Interaction between radiation and Adriamycin damage reduced the width of the shoulder of the X-ray survival curve. This effect was found to persist for at least 24 hr after Adriamycin treatment. Adriamycin did not affect radiation damage when cells were treated either before two-dose fractionation or with the drug present between X-ray exposures. Adriamycin is unique in that its major effect on radiation response is to reduce the survival curve shoulder without affecting two-dose recovery. It is suggested that Adriamycin and radiation produce independent classes of damage that are expressed mutually for killing, with regard to the registration of sublethal radiation damage, but that repair of the latter is unaffected by Adriamycin.


Pharmacology of 5'-esters of 1-beta-D-arabinofuranosylcytosine.

Pharmacological studies of 5'-esters of 1 beta-D-arabinofuranosylcytosine (ara-C) were performed in three species (mouse, pig, and man). In mice, after a single i.p. injection of a suspension of tritiated 1-beta-D-arabinofuranosylcytosine 5'-palmitate (PalmO-ara-C) at a therapeutic dose of 150 mg/kg, 30% of the administered radioactivity was recovered in the urine in 24 hr and 56% was recovered after 7 days. Excretion was less rapid after s.c. administration. ara-C and 1-beta-D-arabino furanosyluracil each accounted for about 50% of the excreted radioactivity, and no PalmO-ara-C was found. Plasma ara-C concentrations of greater than 0.1 microng/ml were detected 24 hr after i.p. administration of PalmO-ara-C (150 mg/kg). Single doses of PalmO-ara-C were effective against L1210 leukemic mice when administered 5 to 7 days before tumor inoculation. In a pig, after i.m. injection of tritiated PalmO-ara-C (60 mg/kg, two sites), only 7% of the administered radioactivity was recovered in the urine over a 1-week period. Similar low rates of excretion were also observed in patients treated i.m. with PalmO-ara-C or 1-beta-D-arabinofuranosylcytosine 5'-benzoate. N ara-C was detected in the plasma, which is consistent with the absence of clinical toxicity or myelosuppression in Phase 1 trials of PalmO-ara-C at doses up to 1500 mg/sq m every 3 weeks for as many as eight courses.


Selective growth of transformed cell lines by rat liver perfusate.

Perfused rat liver releases growth-promoting activity for viral, spontaneous, and chemically transformed cells. After 5 days of incubation with perfusate, cell lines 3T12-NY (a spontaneous fibroblast transformant), NQ-T1 (a chemically transformed fibroblast line), W-8 (a chemically transformed epithelial rat liver cell line increase in cell growth above controls. Their respective normal counterparts: 3T3 Cl 42, A31-714, K-16, and HEF are not so stimulated. Within another set, the virally transformed mouse fibroblast cell line, SV3T3, exhibits a 27-fold increase in growth; however, 3T3 (mouse, fibroblasts), Py3T3 (polyomatransformed 3T3 cells), SV-Fl2-101 (a flat revertant line), and SV-Py-3T3 (a doubly transformed line) are nonresponsive. Perfused rat liver also release survival activity for SV-3T3 cells. The growth-stimulating activity in liver perfusate is selective for transformed cells. It is suggested that the liver may play a role in suporting neoplasia in vivo.


Antitumor activity and preliminary drug disposition studies on chartreusin (NSC 5159).

Chartreusin has exhibited significant therapeutic activity against three experimental mouse tumors (ascitic P388, L1210 leukemia, and B16 melanoma) when tumor cells were inoculated i.p. and drug was administered i.p. In further testing against P388 leukemia, no activity was observed when drug was administered p.o., s.c., or i.v. Chartreusin was very slowly absorbed from the small intestine, thus explaining the lack of activity when administered p.o. When given i.p., the drug precipitated in the peritoneal cavity and was slowly absorbed over several hr. The strong activity observed by this route was related to the prolonged and intimate contact of drug with tumor cells in the peritoneal cavity. Upon s.c. administration, extensive precipitation occurred. Subsequent dissolution and absorption from the injection site were very slow, and measured plasma and tissue levels were quite low. Biliary excretion of chartreusin, the predominant route of elimination. was very rapid, with 80 to 100% of the dose appearing as unchanged drug in the bile within 6 hr after i.v. administration. Rapid biliary excretion after i.v. administration was reflected in a rapid decline in plasma and tissue concentrations to levels (shown by in vitro cell kill experiments) less than those necessary to kill P388 cells. When the bile ducts of i.v.-dosed leukemic mice were ligated, therapeutic activity was observed, confirming that the physiological disposition of chartreusin exerts a major influence on its therapeutic utility.


The distribution and persistence in vivo of Corynebacterium parvum in relation to its antitumor activity.

Killed Corynebacterium parvum was labeled with fluorescein isothiocyanate or 125I, and both preparations were shown to retain lymphoreticular stimulatory and antitumor activity. Large amounts of C. parvum injected i.v. were found in the liver, spleen, and lungs with less in bone marrow and lymph nodes. Apart from a rapid loss from the lungs within 24 hr, the persistence of killed C. parvum was striking, and some intact bacteria were still detectable in the liver and spleen at 15 days. (By contrast, the breakdown of an inactive C. parvum strain in the liver was considerably faster). The blood clearance of 125I-labeled C. parvum injected i.v. into tumor-bearing mice was more rapid than in normal mice, and the absolute, but not the unit, amounts of C. parvum taken up by the spleen and tumor-draining node were increased. 125I-labeled C. parvum was found within the body of established solid tumor, but there was no correlation between the amounts of C. parvum taken up by various mouse solid tumors after i.v. injection and their susceptibility to i.v. C. parvum therapy. The distribution and persistence of C. parvum injected into a tumor lesion was similar to that after s.c. injection. The bulk of the inoculum was retained at the injection site and draining lymph node. Contralateral nodes were unlabeled, and uptake in the liver and spleen was considerably less than after i.v. injection. Although no C. parvum was found in peritoneal cells after i.v. injection, the macrophages in this population became activated and were capable of nonspecifically inhibiting tumor cell growth in vitro.


Early changes in the dynamics of crypt cell populations in mouse colon following administration of 1,2-dimethylhydrazine.

The effects of the carcinogen, 1,2-dimethylhydrazine (DMH), on the proliferative characteristics of the crypt cell population of mouse colon were studied. DMH (20 mg/kg body weight) was injected s.c., weekly, for 2, 8, 16, 20, or 26 weeks. At the end of each treatment period, a group of animals was injected with [3H]thymidine and killed. After 2 weeks of DMH treatment, the crypts appeared normal histologically, but the total number of cells, the number of labeled cells, and the percentage of labeled cells per crypt column had increased. The relative distribution of labeled cells in crypt columns was not changed. DMH treatment did not affect the phases of the cell cycle of epithelial cells and the transit time of these cells through the crypt. None of the indices of crypt dynamics were altered further with the appearance of focal atypias (after 16 weeks of DMH). However, the total number of cells per crypt increased and the percentage of labeled cells decreased as adenocarcinomas developed in adjacent areas of the mucosa (after 20 to 26 weeks of DMH). The exact role of these early mucosal changes in the eventual development of malignant tumor has not been established. However, it appears that DMH carcinogenesis may involve two steps; (a) an initial increase in the number of mitotocally active cells leading to an enlarged cell population; and (b) an eventual transformation of at least some of the crypt cells of the enlarged population.


4-methyl-5-amino-1-formylisoquinoline thiosemicarbazone, a second-generation antineoplastic agent of the alpha-(N)-heterocyclic carboxaldehyde thiosemicarbazone series.

4-Methyl-5-amino-1-formylisoquinoline thiosemicarbazone (MAIQ-1) was studied to determine its potential for clinical trail as a second-generation antineoplastic agent of the alpha-(N)-heterocyclic carboxaldehyde thiosemicarbazone class. MAIQ-1 was shown to be among the most potent known inhibitors of the major target for the expression of antineoplastic activity by this class of agents, the enzyme ribonucleoside diphosphate reductase, requiring only 0.06 micronM for 50% inhibition. This potency at the enzymatic level was consistent with its antineoplastic activity against the murine neoplasms Sarcoma 180, Leukemia L1210, Leukemia P388, and the B16 melanoma. The acetylation of the 5-amino group of the model substrate 5-amino-1,4-dimethylisoquinoline was lower than that of 5-amino-1-methylisoquinoline when incubated with acetyl-coenzyme A and rat liver homogenate. This finding suggests that the presence of the 4-methyl function offers steric hinderance to enzymatic substitution of the adjacent 5-amino group. In vivo metabolism of MAIQ-1 in mice, studied with [3'-14C]MAIQ-1 showed that relatively slow excretion of this agent occurred, since the cumulative urinary excretion of radioactivity was only 35% in 48 HR. About 51% of excreted urinary radioactivity was present in chromatograms in an area corresponding to the iron chelate of MAIQ-1, and only a minor quantity of material migrating like acetylated MAIQ-1 was present in urine, a finding consistent with enzymatic data with liver homogenates. The results indicate that MAIQ-1 has the antineoplastic activity, enzyme inhibitory potency, and relative resistance to metabolic inactivation required of an agent of this class for clinical trials.


Multi-hit kinetics of tumor formation, with special reference to experimental liver and human lung carcinogenesis and some gneral conclusions.

On the basis of the multi-hit concept of cancer formation, the relationships between tumor incidence and dose and time of administration of carcinogen have been analyzed. Simple mathematics have been used, since the available data, in our opinion, hardly justify more sophisticated formularization. The exponential relationship between the cumulative tumor incidence and the dose and time of administration of carcinogen can be described as l(d,t) approximately dmtr. With use of Druckrey's formula, dtn=k, it was derived that the exponent of time, r, is equal to m-n, in which m is the power of the dose dependency of tumor formation [l(d) approximately dm measured at a fixed time] and n is the autonomous time factor featured in the former formula. The factor m is interpretable in terms of the number of discrete events (hits) required for tumor formation, whereas the factor n is mainly determined by the rate of proliferation of intermediate cell populations participating in the carcinogenic process. Since r and n can be experimentally determined, the formula allows the calculation of the exponent (m) of the dose dependency of tumor formation. Analysis of malignant liver tumor formation in the rat by continuous administration of diethylnitrosamine yeilded m = 7, from which it was concluded that seven hits were instrumental in the induction of these liver-cell tumors. Analysis of the formation of less malignant liver tumors after one pulse exposure to the same carcinogen suggested that the process was initiated by at most two concomitant hits in a liver cell and brought to completion by three spontaneous events (changes). The view was advanced that tumor formation in general may result from hits inflicted by the carcinogen applied and from "background" hits (i.e., spontaneous changes and/or hits by carcinogenic stimuli from the environment or present endogenously) and that the relative contribution of these two types of hits to the end effect may depend on dose level and potency of the carcinogen under consideration. It was pointed out that the direct measurement of the dose-response relation (l(d) approximately dm) yields only the number of hits contributed by the carcinogen applied anose rate is low or very low, the contribution of background process becomes significant, and these hits contribute to the power of time, r, of the incidence-time relation. Under these conditions, the formula m-n=r becomes (mex + mb)n=r, where mex and mb denote the number of hits scored by extrinsic carcinogen and background processes, respectively. It is argued that the epidemiological data on lung cancer caused by smoking [l(d) approximately d with respect to smoke dose, mex= 1; l(t) approximately t5 with respect to duration of smoking] are not compatible unless at least one additional background hit (mb greater than or equal to 1) is postulated...


Cytostatic effect of spleen cells of tumor-bearing mice on syngenetic tumor cells.

Spleen cell suspensions of methylcholanthrene-induced tumor-bearing mice were tested for their ability to inhibit tumor growth in vitro. The level of cytostasis was correlated with tumor growth and disappeared rapidly after surgical removal of the tumor. Pretreatment by anti-Thy 1-2 antiserum and complement, or by carbonyl iron and a magnet, showed that adherent, non-T-cells were the main effector cells of the cytostatic antitumor effect. Thymus cells suspensions from tubor-bearing mice were not effective in inhibiting tumor growth. This cytostatic effect was not tumor specific, inasmuch as the same spleen cell suspension inhibited growth of tumor cells of different origin.


Cytotoxic effects of interferon in vitro on granulocytic progenitor cells.

We have utilized in vitro marrow culture techniques to evaluate the cytotoxicity for granulocytic progenitor cells of two highly purified human leukocyte interferon preparations. Concentration- and time-related decrements in granulocytic colony-forming capacity in agar occurred with human and mouse marrow. Although mouse marrow cells were less sensitive than were human cells, these data indicate lack of strict species specificity for the cell growth-inhibitory effects of interferon. Similar cytotoxicity was noted for normal and leukemic human clonogenic cells exposed to interferon for prolonged periods. The decrease in the proportion of granulocytic progenitor cells in DNA synthesis, which occurred at high concentrations, and the diminution by interferon of the cytotoxicity caused by cytosine arabinoside demonstrate that interferon decreases DNA synthesis of granulocytic progenitor cells. The lack of enhanced cytotoxicity for rapidly proliferating mouse post-endotoxin marrow cells indicates that interferon is not a cell cycle-stage-specific drug. These data seem useful for evaluating the suppressive effects of interferon on granulopoiesis and for devising clinical trials with this agent.


Distribution of aryl hydrocarbon hydroxylase inducibility in cultured human lymphocytes.

We measured aryl hydrocarbon hydroxylase (AHH) in cultured human lymphocytes. A striking seasonal variation in AHH activity was observed with induced AHH activity levels from January through May measuring approximately 20% of the values during the remainder of the year. AHH inducibility was determined by comparing lymphocytes from the same person cultured with and without the inducer 3-methylcholanthrene. If measurements are limited to the summer and fall seasons when AHH activity is high, AHH inducibility is reproducible for most persons with repeat determinations on the same person averaging 11% from the mean. The values of AHH inducibility in 53 persons ranged from 0.9 to 5.0, but the distribution of values did not fall into three distinct, nonoverlapping classes as reported by others. We were not able to determine the distribution of AHH inducibility in lung cancer patients since lymphocytes from less than half of the patients tested could be successfully cultured.


Estradiol binding in ovariectomy-responsive and -nonresponsive rat mammary carcinoma.

MTW9, a transplantable mammary tumor in Wistar-Furth rats, is dependent upon high levels of serum prolactin for growth. The mammary tumor can be maintained by coimplantation with a pituitary mammosomatotropic tumor (MTW9-MtT) or by chronic perphenazine administration (MTW9-P). MTW9-MtT does not regress after ovariectomy (OVEX) alone, while, MTW9-P regresses rapidly whether or not rats are maintained on perphenazine. Cytosol estradiol binding was determined in MTW9-MtT, 47.6 +/- 3.6 (N = 9), Kd 9.9 +/- 2.0 X 10(-11) M; MTW9-P, 195.5 +/- 9.1 (n = 16), Kd 27.6 +/- 4.7 X 10(-11) M; MTW9-P after perphenazine was withdrawn, 86.0 +/- 6.0 (n = 6), Kd 9.9 +/- 1.5 X 10(-11) M. Eight S and 4 S peaks were found in cytosols from both tumors by sucrose gradient centrifugation; the peaks differ qualitatively and quantitatively. The possibility that differences in binding levels result from sites filled with endogenous estradiol was critically examined and rejected. Withdrawal of perphenazine results in reduction of estradiol binding but retention of response to OVEX. Hence, response of MTW9-P to OVEX cannot be explained by the 3- to 4-fold increase in estradiol binding over MTW9-MtT. The relationship between estradiol binding and response to OVEX is under study using both mammary tumor models.


The prevention of methotrexate toxicity by thymidine infusions in humans.

Continuous i.v. thymidine (TdR) was given to 12 patients with metastatic cancer in an attempt to prevent methotrexate (MTX) toxicity. MTX was infused in 27 courses with progressive dose increase from 80 mg/sq m for 24 hr to 6 g/sq m for 72 hr. TdR at 8 g/sq m/day was infused concurrently and continued 24 to 48 hr beyond MTX infusion. The median pretreatment serum TdR level was 0.19 micron. With TdR infusion, the median level was 1.5 micronM. Serum TdR fell with a half-time of 8 to 10 min after a pulse dose or cessation of infusion. Spinal fluid TdR equaled serum TdR levels after 2 hr of infusion. Less than 2% of administered TdR appeared in urine. MTX serum levels were proportional to dose infused, ranging from 80 to 100 micronM with 2 g/sq m/day. The half-time for MTX clearance from serum was 4 to 8 hr. Spinal fluid MTX reached equilibrium at 3 to 12% of serum levels by 4 hr. Bone marrow dysfunction during MTX infusion was prevented by TdR as determined by labeling indices and cytofluorographic analyses. Toxicity was not seen in patients with normal MTX clearance using 48-hr infusions of MTX where TdR was continued for an additional 48 hr after the MTX infusion had ended. However, 3 of 6 courses of MTX at 6 g/sq m over 72 hr led to toxicity. Toxicity was reversible in 2 patients, 1 of whom was retreated with a similar dose duration of MTX without toxicity when TdR was continued beyond the end of the MTX infusion for 48 hr instead of the usual 24 hr. The 3rd patient with toxicity died of progressive disease and thrombocytopenia 19 days after treatment. No TdR-related toxicity or unusual MTX toxicity was detected. Antitumor effects were noted in 4 patients. TdR offers significant protection against MTX toxicity and deserves further clinical study.


Survival differences exhibited by normal and transformed rat liver epithelial cell lines in the aggregate form.

Normal and transformed rat liver epithelial cell lines exhibited differences in the ability to survive in the aggregate form. Normal rat liver epithelial cells in the aggregate form underwent a rapid decline in the number of viable cells, while counterpart transformed epithelial cells exhibited an ability to survive and proliferate in the aggregate form. This survival ability was found to correlate with colony formation in soft agar and tumorigenicity in nude mice. Cell survival in the aggregate form could possibly serve as a criterion for in vitro transformation of epithelial cells derived from rat liver.


Effects of 6-thioguanine on macromolecular events in regenerating rat liver.

Regenerating rat liver was used as a semisynchronous system in which to investigate the effects of 6-thioguanine on biochemical processes occurring in discrete phases of the cell cycle. 6-Thioguanine inhibited the first wave of DNA biosynthesis in regenerating rat liver. This effect appeared to be the result of a decrease, caused by 6-thioguanine, in the induction of several enzyme activities (i.e., thymidine kinase, deoxycytidylate deaminase, cytidine diphosphate reductase, and DNA polymerase) necessary for the initiation of DNA replication in regenerating liver. There was a fairly short period during which 6-thioguanine could be given to rats to accomplish the inhibition of the appearance of the induced activities of these enzymes; this period corresponded to the time just before enzyme induction. The inhibition of the induced synthesis of this group of enzymes occurred in the presence of an intact translational apparatus and intact polysomes and in the absence of interference with the incorporation of radioactive leucine and tyrosine into total protein of liver. Synthesis of polyadenylate-containing RNA was depressed in 6-thioguanine-treated rats, whereas the synthesis of polyadenylate-lacking RNA was unaffected. It is suggested that the inhibition of the synthesis of polyadenylate-containing RNA by 6-thioguanine is at least in part responsible for the observed decrease in induced enzyme activities and the resulting interference with DNA replication.


Effects of estrone, estradiol, and estriol on hormone-responsive human breast cancer in long-term tissue culture.

The effects of estrone, estradiol, and estriol on MCF-7 human breast cancer are compared. In this estrogen-responsive cell line, all three estrogens are capable of inducing equivalent stimulation of amino acid and nucleoside incorporation. Estriol is capable of partially overcoming antiestrogen inhibition with Tamoxifen (lCl 46474), even when antiestrogen is present in 1000-fold excess. Antiestrogen effects are completely overcome by 100-fold less estriol. Studies of metabolism of estrogens by MCF-7 cells revealed no conversion of estriol to either estrone or estradiol. All three steroids bind to a high-affinity estrogen receptor found in these cells. The apparent dissociation constant is lower for estradiol than for estrone and estriol, but all three bind to an equal number of sites when saturating concentrations are used. Tritiated estrogens used in binding studies were shown to be radiochemically pure. We conclude that estriol can bind to estrogen receptor and stimulate human breast cancer in tissue culture. Our data do not support an antiestrogenic role for estriol in human breast cancer.


Synthesis of p-nitrophenyl 6-O-(2-acetamido-2-deoxy-beta-d-glucopyranosyl)-beta-D-galactopyranoside and p-nitrophenyl O-beta-D-galactopyranosyl-(1 linked to 3)-O-(2-acetamido-2-dexoy-beta-D-glucopyranosyl)-(1 linked to 6)-beta-D-galactopyranoside.

Condensation of 2-methyl-(3,4,6-tri-O-acetyl-1,2-dideoxy-alpha-D-glucopyrano)-[2',1':4,5]-2-oxazoline with p-nitrophenyl 2,3-di-O-acetyl-beta-D-galactopyranoside (4), followed by saponification of the resulting disaccharide derivative, produced p-nitrophenyl 6-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-beta-D-galactopyranoside as a crystalline compound. Reaction of 2-methyl-[4,6-di-O-acetyl-1,2-dideoxy-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-alpha-D-glucopyrano]-[2',1':4,5]-2-oxazoline with 4 in a similar reaction-sequence provided the title trisaccharide compound.


Effect of selected drugs and myocardial infarction on the disappearance of creatine kinase from the circulation in conscious dogs.

Estimates of infarct size based on serial plasma creatine kinase (CK) changes have been made utilising the disappearance rate of CK from blood (kd) as one parameter. This study was performed to evaluate the effects on CK disappearance of myocardial infarction per se and selected drugs often used in the management of patients with myocardial infarction. Fifty-six conscious dogs were studied. Canine myocardial CK was isolated and radioactively labelled. Experiments were performed with intravenous injections of unlabelled CK or with radioactively labelled material. After injection, plasma CK activity declined monoexponentially (r = -0.95, n = 30) exceeding the rate of CK disappearance in vitro in whole blood or plasma. Three successive daily determinations of kd differed by less than or equal to 10% in the same dog (n = 5). Removal of radioactively labelled protein from plasma paralleled disappearance of plasma CK enzyme activity for several hours after i.v. injection of 14C-CK (n = 5). Myocardial infarction after occlusion of the left anterior descending coronary artery altered kd by less than 10% (n = 5) estimated after i.v. injection of 14C-CK. Administration of large doses of Nembutal (30 mg-kg-1), morphine (2 mg-kg-1), or Valium (1 mg-kg-1) decreased kd markedly (n = 17), but low doses of morphine (0-2 mg-kg-1) or Valium (0-1 mg-kg-1) did not substantially diminish kd. Thus, enzymatic estimates of infarct size are not likely to be influenced by changes in kd occurring during myocardial infarction. However, modification of estimates may be required when pharmacological interventions are employed, capable of altering CK disappearance.


Reactive hyperaemia in the dog heart: inter-relations between adenosine, ATP, and aminophylline and the effect of indomethacin.

Intracoronary adenosine, ATP, and the release of an 8 second occlusion increased coronary blood flow (CBF) to a similar extent. Aminophylline decreased the CBF response to adenosine by 80% and that to an 8 s occlusion by 20% but did not change the CBF response to ATP. Indomethacin had no effect on CBF. The results suggest that the increase in CBF after brief occlusions is not mediated in a major way by adenosine or prostaglandins.


Left ventricular compliance in acute myocardial infarction in man.

Left ventricular end-diastolic pressure (P) and volume (V) were measured in 12 patients with acute myocardial infarction. It was assumed that the diastolic P-V relationship was exponential and corresponded to the formula P=be KV. In 7 patients submitted to volume loading, several data points of this relationship were obtained and at zero volume, the mean intercept with the ordinates was 0.037+/-0.015 kPa (SEM) (0.28+/-0.12 mmHg). In the other 5 patients, the P-V curve was plotted through this intercept and the pressure and volume co-ordinates obtained by control. The K coefficient (passive elastic modulus) was greater, and the normalised left ventricular compliance index (dV/VdP) was smaller in the infarct group than in the control group. This suggests decreased left ventricular compliance during the acute phase of myocardial infarction. By comparing left ventricular function curves plotted using either end-diastolic pressure or end-diastolic volume as the stretch index it is possible to evaluate the relative participation of decreased compliance and depressed contractility in global left ventricular function.


Pathophysiological correlates of thallium-201 myocardial uptake in experimental infarction.

The pathophysiological correlates of thallium-201 (201TI) myocardial uptake were studied in  a 24-hour-old closed-chest canine infarct model. Reduction in regional 201Tl uptake correlated well with the magnitude of tissue creatine phosphokinase depletion and microsphere estimates of transmural blood flow. In low flow endocardial regions 201Tl occasionally under-estimated the magnitude of flow reduction. Even slight reductions of 201Tl uptake (less than 0.86 of normal) were associated with histopathological and histochemical evidence of necrosis.


Screening for carotid junction disease by spectral analysis of Doppler signals.

The established test for disease in the internal carotid artery using continuous wave Doppler is to listen for flow velocity changes over the supraorbital artery with ipsilateral temporal (or facial) artery compression. This is only reliable when there is a reduction in mean pressure (and flow) distal to disease in the internal carotid artery, ie reduction of lumen diameter by more than 85%. In this study, 101 vessel segments (48 with disease at the carotid junction, 53 normal) were compared with the results of angiography. Seven gave a positive temporal artery occlusion test, all of which showed severe disease. However, spectral analysis of the Doppler signals from supraorbital and common carotid arteries showed sonagram changes both with ageing and with disease. In particular, the ratio of primary peak (A) to secondary peak (B) in systole falls, the A/B ratio being lower in disease than in health. At A/B ratios less than 1.05 there was an 88% probability of disease at the carotid junction. 36/48 (75%) diseased junctions were detected, including almost all major lesions. The method did not so reliably detect small lesions (less than 2 mm plaques, less than 60% lumen diameter stenosis, and 'minimal atheroma'). In 5/53 normal junctions the A/B ratio was in the disease range. Scanning the carotid junction for turbulence yielded additional information in some cases.


Partial standing wave formation above an abdominal aortic stenosis.

Reflection from an arterial discontinuity, such as a stenosis, would be expected to produce partial standing waves of pressure and flow proximal to the stenosis. This phenomenon is demonstrated by determining the amplitude changes of the harmonic components of pressure and flow waves recorded at three sites at different distances from an experimental stenosis of the abdominal aorta in dogs. To minimise the effect of reflections from other arterial sites, such as the peripheral beds, the animals were vasodilated. Impedance and propagation velocity measurements were made to estimate the contribution of peripheral reflections in the harmonic components of the aortic pressure and flow pulses. In general, the  peripheral contribution appeared to be small for harmonics greater than the first. The results indicate that, for the 'closed' type of reflection at the stenosis, a pressure antinode and a flow node occur immediately proximal to the stenosis. As the distance from the stenosis to the measurement site is increased, nodes and antinodes of pressure and flow occur at frequencies which correspond to integer multiples of lambda/4. Similar fluctuations take place in the impedance modulus proximal to the stenosis, such that close to the stenosis the modulus is a maximum, at the lambda/4 distance the modulus is a minimum and at the lambda/2 distance it is again a maximum. The extent of these impedance changes with distance indicates that the attenuation of the reflected, backwardgoing waves is greater than found for forwardgoing waves and that the diagnostic assessment of a vascular obstruction by means of a proximal measurement of pressure or flow may be subject to error if the measurement is not made close to the obstruction.


Creatine kinase isoenzymes: their separation and quantitation.

The cardiospecificity of the MB isoenzyme of creatine kinase, EC 2.7.3.2, (CK) with its associated diagnostic and research value has resulted in the development of a number of procedures for the separation and quantitation of the three isoenzymes of CK. In our experience methods involving cellulose acetate electrophoresis, apposition incubation, and fluoroscanning for quantitation are of limited linearity, insensitive, and irreproducible. We have, therefore, developed a method which overcomes these difficulties. Our method is based on agarose gel electrophoresis, gel overlay incubation with optimisation of all substrates and elution of the NADPH into solution for isoenzyme quantitation. We have: (1) characterised this technique; (2) used it to verify the extent to which the MB isoenzyme of CK is cardiospyocardial; (3) studied its application to the diagnosis of acute myocardial infarction; and (4) compared it with existing methods involving dithiothreitol activation and ion exchange chromatography.


Gap junctions in the cardiac muscle cells of the lamprey.

Electron microscopy of both thin sections and freeze-fracture replicas has demonstrated the occurrence of gap junctions (nexuses) in the cardiac muscle cells of the lamprey. These gap junctions are identical in basic structure with those found in the mammalian heart. However, they are much smaller (less than 0.5 micron in diameter), and more irregularly distributed than the typical gap junction in the mammalian heart. These small gap junctions seem to provide a structural basis for the electrical coupling between cardiac muscle cells in the lower vertebrates. In addition, the well developed sarcoplasmic reticulum and subsurface cisternae, which contain an electron dense spheroidal cast, frequently observed in the cardiac muscles of the lamprey.


Morphological investigation on phenylhydrazine-induced erythropoiesis in the adult mouse liver.

In adult mice suffering from a phenylhydrazine (PHZ)-induced hemolytic anemia, erythropoietic islands were observed in the liver. These islands were studied with the light and electron microscope. Within two days after the beginning of four daily injections of PHZ, erythoid elements appeared in the sinusoids and central veins. A maximum number of erythroblasts was found on day 7. Light and electron microscopic observations revealed that the erythropoietic islands consisted of centrally located macrophages(CM) with a Kupffer cell-like morphology, surrounded by erythroblasts, which were often of the same maturation stage. CM in central veins (CM-V) and in sinusoids (CM-S) were found to have a different morphology. The CM-V phagocytized less circulating red blood cells and were in contact with a smaller number of erythroblasts. Furthermore, the contact areas between erythroblasts and CM-S extended for a much longer distance than those between erythroblasts and CM-V. The progenitor cell for the CM-V is most likely a monocyte, since cells which were morphologically determined as monocytes were found to appear on the first day of the PHZ treatment and differentiated into macrophages within about 2 days. The origin of the CM-S population was less clear, but could be monocytic as well. These data are tentatively explained as a migration of a progenitor of a cellular component of the erythroid micro-environment into the liver after appropriate stimuli. In contrast to fetal liver erythropoiesis, erythroblasts in the adult liver occurred only incidentally extrasinusoidally. Furthermore, specialized membrane contacts between erythroblasts and CM or hepatocytes could not be observed in adult liver. Ferritin could not be detected on the erythroid cell membrane or located in coated vesicles. Also, no ferritin could be observed within or attached to the finger-like  processes of CM. The observations suggest that the coated vesicles in erythoid elements are partly exocytotic vesicles and are not specific for ferritin transport. The morphological aspects of PHZ-induced extramedullary erythropoiesis is discussed in relation to the hemopoietic microenvironment.


A mechanical momentum in ultrastructural development of the heart.

The question of whether mechanical moments participate in ultrastructural development of the heart cannot be decided by examining heart tissue samples during embryonic life, for during maturation processes in vivo mechanical factors are always present. The significance of mechanical moments can only be investigated in a system which allows a distinction to be made between pulsations of heart myocytes under conditions of contraction against and under conditions of contraction without mechanical stress. This double possibility is provided by cell culture. An example in which mechanical influences are absent are the so-called "minihearts"; these are cell agglomerations which are detached from the culture substrate. Their cell contractions do not act against any mechanical resistance. In the electron microscope they show abundant filaments, Z-line material and membrane specializations. The highest degree of development, however, does not exceed that characterizing the cells with which the cultures were started. Even some dedifferentiation and degeneration are apparent in the minihearts. No intercalated discs can be found even after 12 weeks, provided that the culture had been started with really isolated cells. The representatives in culture of a myocyte's connection with the heart's mechanical action are the cords, along which attached points alternate with free strands. The pulsation of these strands is restrained during each contraction by their ends, which are fixed on the culture substrate. Thus, the myocytes contract against a resistance, and in this respect their pulsations resemble those of the heart, in which the myocytes' contraction acts against the pressure of the blood. The myocyte culture under these mechanical condition, after a culture time of 10 weeks, produces electron micrographs of mature cells with reduced cytoplasm, aligned mitochondria and fibrils and intercalated discs.


Ultrastructure of arterioles in the cat brain.

A total of 110 arterioles were examined in the brains of cats; different sites were studied including the cortex, putamen, pons and crus cerebri. No internal elastic laminae were seen in the subendothelial space, although occasional fragments of elastic material were present in the larger arterioles. The media was composed of one, two or three layers of smooth muscle cells which interlocked in such a way that the vessel wall thickness was constant. Numerous tight junctions were seen between adjacent smooth muscle cells and between the endothelium and smooth muscle cells. Apart from the usual cell organelles, the smooth muscle cells of arterioles had numerous dense patches on the cell surface. The structure of the adventitia varied according to the diameter of the vessel and the site in the brain; it contained adventitial cells, bundles of collagen fibres and nerve fibres. Innervation of arterioles was more constant in the brain stem than in the cortex. Metarterioles had less specialised, atypical smooth muscle cells, a discontinuous media and numerous, extensive myoendothelial tight junctions; they were not innervated by nerve fibres. The diameter of metarterioles was less than 10 micronm whereas that of arterioles was 10-45 micronm. The possible functional aspects of arteriolar innervation are discussed.


The surface fine structure of the ependymal lining of the lateral ventricle in rats with hereditary hydrocephalus.

The ependyma of the lateral ventricle of rats with hereditary hydrocephalus was studied using scanning electron microscopy. Normal rats from the same litters were used as control animals. The surface morphology of the lateral ventricle of normal rats corresponded to results reported by other authors. The most prominent changes in the surface morphology of the ependyma of the hydrocephalic rats were seen in the cilia. They were shortened, fewer in number and clumped or matted. The surface of the ependymal cells was flattened and contained small, irregular projections. The number of large  supraependymal cells, regarded as neurons, appeared to have diminished in the hydrocephalic rats. The number of supraependymal macrophages was greatly increased in these rats, suggesting the existence of an ependymitis.


Effect of preganglionic sympathectomy on the cholinesterase activity in the superior cervical ganglia of rats and hamsters.

By employing biochemical assay and histochemical enzyme techniques the effect of preganglionic sympathectomy on the cholinesterase (ChE) activity in the superior cervical ganglia of rats and hamsters was investigated. Biochemical assays indicate that the ChE activity in the superior cervical ganglia of adult rats and hamsters is 57.19 and 28.63 respectively (expressed in micron moles acetylcholine hydrolyzed per min per g of tissue); two weeks after preganglionic denervation, about 50% and 60% of ChE activity are lost respectively. Histochemical enzyme examination reveals that in the rat superior cervical ganglion, the majority of the neurons are adrenergic with weak to moderate acetylcholinesterase (ACHhE) reaction and the minority of the neurons are cholinergic with strong AChE activity, while only one type of adrenergic neurons exhibits a weak AChE activity in the hamster superior cervical ganglion. The AChE activity is localized in the perinuclear area, in the cisternae of the rough surfaced endoplasmic reticulum, in the Golgi complex and on the plasma membrane of the hamster's neurons; it is mainly locolized in the cisternae of the rough surfaced endoplasmic reticulum of the rat's neurons. AChE reaction product is also detected on the aeolemmal membranes of the preganglionic nerve fibers in the sympathetic ganglia of rats and hamsters. After preganglionic sympathectomy, the AChE activity in the adrenergic neurons and in the preganglionic unmyelinated nerve fibers is markedly reduced, whereas the cholinergic neurons and preganglionic myelinated nerve fibers remain unchanged. On the basis of these results two conclusions have been reached: (1) The fact that strong AChE activity localized in the cholinergic neurons and preganglionic myelinated fibers is not influenced by denervation, suggests that these structures are able to produce AChE. (2) The reduction of AChE activity in the rat and hamster superior cervical ganglia two weeks after preganglionic denervation, observed by histochemical examination, can be correlated with a concomitant measurable reduction determined by biochemical assays.


Types and arrangements of neurons in the crayfish optic lamina.

The neural arrangements in the optic lamina of the crayfish Pacifastacus leniusculus Dana have been studied by light microscopy by means of silver impregnation techniques. The lamina is composed of columnar synaptic compartments (cartridges). Each cartridge is composed of seven receptor terminals distributed in two layers and second-order monopolar neurons connecting the lamina with the second synaptic region, the medulla externa. The neurons found in the lamina consist of five classes: monopolar neurons, centrifugal small-field neurons, tangential neurons, multipolar cells (possibly of a glial nature) and photoreceptor axons (fig. 13). Among the monopolar cells, five types are classified (M1-M5) according to their lamina arborizations. Two types are stratified (M3 and M5) corresponding to the photoreceptor terminal strata. On this basis, the lamina plexiform layer is subdivided into two layers (epl1 and epl2). The remaining monopolar neurons have lateral processes in both layers, two of them within one cartridge (M1 and M2) and one over several cartridges (M5). There is one type of small-field centrifugal neuron (C1) and two types of tangential medulla to lamina neurons (Tan1 and Tan2), both having processes covering a large number of cartridges. Multipolar cells with cell bodies distal (MP1) or proximal (MP2) to the plexiform layer send processes to several cartridges. The receptor axons consit of three types. One has terminals in epl1 or epl2, the second has its terminal in epl1 and a thin process to epl2, and the third (corresponding to the 8th retinular cell) bypasses the lamina and has a terminal in the medulla externa. A brief comparison is made with the neural arrangements in the lamina of the Norway lobster Nephrops norvegicus L.


Spermatogonia and the cycle of the seminiferous epithelium in the nine-banded armadillo.

The cycle of the seminiferous epithelium of the nine-banded armadillo can be divided into ten stages. As in most mammals, only one stage is observed per tubular cross-section. The process of spermiogenesis can be divided into thirteen steps according to the development of the acrosomal system and the flagellum. Four generations of spermatogonia are abserved in the germinal epithelium: 1) stem cells, 2)type "A", 3) intermediate, and 4) type "B" spermatogonia. The stem cell is characterized by a highly irregular nucleus and the presence of glycogen in its cytoplasm. The type "A" spermatogonium contains an oblong nucleus with one or two shallow infoldings of the nuclear membrane. The intermediate spermatogonium contins an ovoid nucleus characterized by one or two nuclei and heterochromatin scattered in the nuceoplasm. The nucleus of the type "B" spermatogonium is more spherically shaped with a centrally placed nucleolus and heterochromatin associated with the nuclear envelope.


A histochemical study of the innervation of cerebral blood vessels in the snake.

Dual innervation of snake cerebral blood vessels by adrenergic and cholinergic fibres was demonstrated with the use of histochemical methods. Although the nerve plexuses are somewhat less dense, the essential features of innervation of the blood vessels are similar to those of mammals with the exception that the adrenergic plexuses are more prominent than the cholinergic plexuses. The major arteries of the cerebral carotid system have a rich nerve supply. However, the innervation is less rich in the basilar and poor in the spinal (vertebral) arteries. Although the arteries supplying the right side of head are poorly developed, three pairs of arteries, cerebral carotids, ophthalmics and spinals, supply the snake brain. The carotids and ophthalmics are densely innervated and are accompanied by thick nerve bundles, suggesting that the nerves preferentially enter the skull along those arteries. Some parenchymal arterioles are also dually innervated. Connection between the brain parenchyma and intracerebral capillaries via both cholinergic and adrenergic fibres was observed. In addition cholinergic nerve fibers, connecting capillaries and the intramedullary nerve fibre bundles, were noticed. Capillary blood flow may be influenced by both adrenergic and cholinergic central neurons. The walls of capillaries also exhibit heavy acetylcholinesterase activity. This may indicate an important role for the capillary in the regulation of intracerebral blood flow.


Observations on the marginal ruffles of an established fibroblast-like cell line.

LW13K2 cells, a clone of a spontaneously in vitro transformed derivative of embryonic Lewis rat fibroblastic cells, were studied by phase contrast cine-light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The ruffles found at the advancing edge of cells grown on glass substrates in vitro form and recede in a period of less than one min if they do not make an attachment of the substrate. If they fail to make an attachment they may form pinocytotic channels near the leading edge as described by Price (1972) and/or collapse, generally backwards, towards the cell body. The "spines" which appear to reinforce the membranous ruffles are the last structures to disappear, and accumulate in an irregular array behind the ruffling edge; this area is behind that in which pinocytosis occurs. In comparison with the sparse numbers of ribosomes found in the trailing edge, they are present in notable concentrations near the leading, ruffling edge of the cell. No membrane vesicles have been found in or near the ruffling edges at the ruffle-spine concentration zone.


Electron microscopic studies on the development of the chorion of the viviparous teleost Dermogenys pusillus (Hemirhamphidae).

Eight stages in the oogenesis of Dermogenys pusillus were selected in order to demonstrate the formation of the egg membrane. In young oocytes (stages 1 and 2) the contact between oocyte and follicular cells is rather close. During stage 3 microvilli arise from the oocyte, and the follicular cells protrude lobopodia-like cell processes. When the microvilli have become arranged more regularly, the homogeneous material of the zona radiata externa is deposited between them (stage 4). During the subsequent stage (5) the inhomogeneous zona radiata interna appears. It attains its greatest thickness and its characteristic fine structure during stage 6. It then consists of cross-banded fibrillae and lamellae. Later on (stage 7) the egg membrane flattens, and finally it is a compact chorion consisting perhaps of very fine fibrils. Because of this development and of its comlex fine structure the egg membrane of Dermogenys like that of Zoarces resembles that of oviparous teleosts but remains consideribly thinner. The eight stages of oogenesis in Dermogenys are compared with those described by Arndt (1956) in several limnetic teleosts.


Ultrastucture of the male rat hypophysis chronically grafted under the kidney capsule.

Male rats were divided in two experimental groups. In group I two partes distales of the hypophysis were grafted under the kidney capsule and in group II two complete hypophyses were transplanted. Animals were  killed 5 to 22 months after the operation. The grafted tissue was excised and processed for light and electron microscopy. The transplanted pars distalis tissue showed a well developed vascularisation in contrast to the pars intermedia which appeared poorly vascularised. Six different cell types were observed in grafted pars distalis. They correspond to the different types of cells found in the rat pars distalis "in situ". The predominant cell type in the graft displayed all the morphological characteristics of stimulated prolactotrophs. Pars intermedia cells appeared hypertrophied resembling the MSH cells under stimulation. Two types of syncytial formations were frequently seen. One of them appeared to originate from prolactotrophs and the other from MSH cells. Bodian impregnated fibres and structures resembling either growth cones of axons or typical nerve endings were observed in the pars intermedia of long-term grafted hypophyses. Pituicytes remained as isolated clusters of cells. Canaliculi lined by two or more pituicytes were observed. Saccular formations resembling the hypophyseal cleft appeared in all grafts studied. The present findings suggest that in the male rat the chronically grafted pituitary gland is capable of synthesising most or all the hormones which are known to be produced by the gland "in situ". Furthermore, prolactin and MSH seem to be the predominant secretion of the transplanted pituitary.


Sterol synthesis. Chemical synthesis of 3beta-benzoyloxy -14alpha, 15alpha-epoxy-5alpha-cholest-7-ene, a key intermediate in the synthesis of 15-oxygenated sterols.

3BETA-Benzoyloxy-14alpha, 15alpha-cholest-7-ene was obtained in 96% yield upon treatment of 3beta-benzoyloxy-5alpha-cholesta-7, 14-diene with m-chloroperbenzoic acid. The delta7-14alpha, 15alpha-epoxy-steryl ester provides a useful intermediate for the syntheses of sterols with an oxygen function at carbon atom 15. For example, treatment of 3beta-benzoyloxy-14alpha, 15alpha-epoxy-5alpha-cholest-7-ene with methanolic hydrochloric acid gave 3beta-benzoyloxy-5alpha-cholest-8(14)-en-15-one in 82% yield.


Synthesis an crystal structure of 3beta-p-bromobenzoyloxy-14alpha, 15alpha-epoxy-5alpha-cholest-7-ene.

The chemical synthesis of 3beta-bromobenzoyloxy-14alpha, 15alpha-epoxy-5alpha-cholest-7-ene is described. Single crystal structral analysis was employed to unambiguously determine the location and absolute configuration of the epoxide moiety in the 3beta-p-bromobenzoyloxy-14alpha, 15alpha-epoxy-5alpha-cholest-7-ene. The space group of the crystal was P1, with unit cell parameters: a=10.873 A, b=13.841 A, c=11.037 A, alpha=75.19 degrees, beta=78.79 degrees, gamma=101.57 degrees, and two molecules per unit cell. Intitial phases were derived from the two bromine atoms. Least squares refinements on all non-hydrogen atoms were carried out to a final unweighted R value of 0.10 and weighted R value of 0.04. The epoxide ring was located at the 14, 15 position and was found to extend to the alpha side of the molecule. Molecular measurements for asymmetry parameters of the sterol nuceus indicate that ring A has a symmetrical chair conformation and ring B has a half chair conformation due to the double bond at C(7). Ring C has a fairly distorted chair conformation due to the trigonal C(8) on one sie and the almost planar 5-membered ring on the other. Ring D has the 17alpha-envelope conformation.


Benzene-lecithin interaction interaction in lecithin-benzene solutions. Part L Magnetic deuterium relaxation studies.

2D relaxation times of deuterobenzene in lecithin-benzene solutions were measured at 4.4 and 11 MHz with respect to concentration and temperature. At the temperature of the transition from the micellar solution to the gel state the relaxation behaviour was drastically changed. Analysis of the experimental results performed on the basis of familiar relaxation theory shows that there are sites at which benzene interacts with lecithin in the micellar solution as well as in the gel state. The interaction enthalpies and entropies determined for the two benzene species existing in the gel state are--1.3 kcal/mol,--20 eu and--3.1 kcal/mol, --24 eu.


Field desorption mass spectrometry of phospholipids. III. Survey of structural types.

A survey has been conducted of the behavior of a wide variety of phospholipids and related materials under field desorption mass spectrometric conditions. Phosphatidyl cholines, both acyl and alkyl, phosphatidyl ethanolamies, phosphatidic acids, the corresponding lyso compounds, glycerophosphoryl lipids and sphingolipids are among the species studied. Most of the 50 compounds measured as single species gave M + H as base peak, some associated ions, and fragment ions which became increasingly significant at higher anode temperatures. Problems encountered include interference from organic impurities and alkali metal ions, poor reproducibility of minor ions due to low ion collection rates and potential confusion in structrual assignments caused by reactions occurring on the anode prior to desorption. Various approaches to overcome these difficulties are discussed, and the potential of the field desorption technique for species specific analysis of naturally occurring phsopholipid mixtures is demonstrated by three examples.


The hemodynamic effects of potassium deficiency in the dog.

Potassium deficiency for 3 weeks in dogs caused 374 +/- 38 mEq of sodium retention with increase in body weight, plasma volume, and inulin space. Cardiac output increased from 3.7 +/- 0.6 to 5 +/- 0.6 liters/min (P less than 0.02) and systemic vascular resistance decreased from 3,050 +/- 590 to 2,000 +/- 286 dynes/cm per sec2 (P less than 0.05). Plasma renin activity (PRA) increased from 0.4 +/- 0.1 to 17.2 +/- 0.9 ng/ml per hour (P less than 0.01) without change in plasma aldosterone. Angiotensin sensitivity decreased from a rise of 37 +/- 4 mm Hg in mean arterial pressure (MAP) to 10 ng/kg per min before potassium depletion to a rise of 10 +/- 2 mm Hg after hypokalemia. Urinary prostaglandin E (PGE) excretion increased from control values of 1,224 to 1,556 ng/day to 9,352 +/- 3,670 after 21 days of hypokalemia (P less than 0.01). Indomethacin, 150 mg a day for 3 days, decreased urinary PGE to control values as PRA decreased from 17.2 +/- 5.9 to 1.1 +/- .3 ng/ml per hour and angiotensin sensitivity was partially restored. These findings indicate that hypokalemia increased urinary PGE with extracellular fluid volume expansion, decreased sensitivity to angiotensin and increase in PRA.


Production of sustained hypertension by chronic intrarenal norepinephrine infusion in conscious dogs.

The purpose of this study was to determine whether increased sympathetic nervous system activity with proportionally greater stimulation to the kidney could result in sustained hypertension. This was simulated by continuous intrarenal norepinephrine infusion. Effects of chronic infusion of norepinephrine (0.285 microng/kg per min) into the renal artery and inferior vena cava were compared in uniephrectomized conscious dogs. Ten days of intrarenal norepinephrine infusion produced a sustained rise in mean arterial pressure (25 mm Hg), and a 32-mEg positive sodium balance occurred. Inferior vena caval infusion caused a transient rise, lasting 24 hours, in mean arterial pressure which was associated with a 54-mEq natriuresis. With renal artery infusion, peripheral plasma renin activity rose from 1.0 +/- 00.2 to 4.4 +/- 0.8 ng angiotensin I/ml per hour at 1 hour (P less than 0.002) and fell to 1.4 +/- 0.4 at 24 hours (not significant). Inferior vena caval infusion produced a similar result. [Sar1,ala8]angiotensin II (6 MICrong/kg per min) produced no significant change in arterial blood pressure. (alpha-Adrenergic blockade with phentolamine normalized the blood pressure. Renal plasma flow was chronically decreased by about 25% in dogs given intrarenal norepinephrine; no significant change in glomerular filtration rate occurred. The cardiac output decreased from a control of 7.2 +/- 0.6 to 4.8 +/- 0.1 liters/min (P less than 0.01) and total peripheral resistance was increased from a control of 13 +/- 1 to 26 +/- 1 resistance units (RU) (P less than 0.0005) in dogs given intrarenal norepinephrine. The data indicate that chronic intrarenal infusion of norepinephrine in uninephrectomized conscious dogs results in sustained hypertension characterized by decreased renal plasma flow, normal glomerular filtration rate, positive sodium balance, and increased total peripheral resistance due to norepinephrine-dependent vasoconstriction.


Neurogenic control of renal tubular sodium reabsorption in the dog: a brief review and preliminary report concerning possible humoral mediation.

The evidence supporting a role for direct neurogenic control of renal tubular sodium reabsorption is reviewed. Electron microscopic and fluorescence histochemical studies have demonstrated adrenergic nerve terminals in direct contact with basement membranes of mammalian renal tubular epithelial cells. Low level direct or baroreceptor reflex stimulation of renal sympathetic nerves produces an increase in renal tubular sodium reabsorption without alterations in glomerular filtration rate, renal blood flow, or intrarenal distribution of blood flow. The antinatriuresis was prevented by prior treatment of the kidney with guanethidine or phenoxybenzamine. Rat kidney micropuncture studies have localized the site of enhanced tubular sodium reabsorption to the proximal tubule. Possible indirect mediation of the antinatriuresis by other humoral agents known to be released from the kidney upon renal nerve stimulation was explored. Renal blockade to circulating angiotensin II did not alter the antinatriuretic response to low level direct renal nerve stimulation. Indomethacin was used to inhibit prostaglandin synthesis; this resulted in a rise in mean arterial pressure, a fall in renal blood flow, no significant change in glomerular filtration rate, and a variable fall in urinary sodium excretion. Despite inhibition of prostaglandin synthesis, low level direct renal nerve stimulation produced an increase in renal tubular sodium reabsorption in the absence of changes in renal hemodynamics. Thus, the antinatriuresis of low level direct renal nerve stimulation is not mediated by either circulating angiotensin II or prostaglandin.


A comparison of the patterns of mother-baby interaction for a group of crying, irritable babies and a group of more amenable babies.

Ten babies aged 9-14 months, with a previous history of excessive crying behaviour and sleeplessness were matched with similar more contented babies. The twenty mother-baby pairs were observed individually in a 30-minute play session to test the hypothesis that prolonged crying behaviour of babies over several months would have an aversive effect on their mothers to the extent that even after this behaviour had ceased the mothers would interact with the babies less and these pairs would be less responsive to each other's overtures than the non-crying mother-baby pairs. Significant differences were seen between the two groups, 'the criers' group of pairs interacting less (P less than 0.01) and were less responsive to their partners (P less than 0.01); the most marked difference being the percentage of overtures made by the 'cryer' babies which were not responded to by their mothers (P = 0.001).


Evidence that prostaglandin synthesis inhibitors increase the concentration of sodium and chloride in rat renal medulla.

Thirty minutes after indomethacin (10 mg/kg, iv), a prostaglandin synthesis inhibitor, had been given to 10 rats, the Na concentration in renal papilla averaged 349 mEq/kg H2O, whereas it averaged only 181 in 14 "non-indomethacin" control rats (P less than 0.0001). Papillary plasma flow was closely similar in both groups. In a subsequent study, eight "indomethacin" rats had the same papillary flow as seven non-indomethacin rats but had a papillary Na concentration of 358 vs. 185 in the non-indomethacin controls (P less than 0.0001). In nine more rats, indomethacin increased Cl concentration in papillas by 66% (P less than 0.0001), while Na concentration increased 60% (P less than 0.0001). In eight other rats, micropuncture indicated that indomethacin does not greatly alter delivery of fluid out of late proximal tubule. Meclofenamate, another inhibitor, increased papillary Na just as much as indomethacin. Papillary urea is not changed with indomethacin. Thus, papillary Na concentration was almost twice as high in indomethacin rats, despite similar papillary plasma flow and late proximal flow. Apparently, inhibiting prostaglandin synthesis is associated with either a great increase in Na or Cl "pumping" or a great decrease in Na or Cl "leak" in either collecting duct or ascending limb, or in both. The collecting duct and papillary interstitial cells both synthesize prostaglandins, which seem to have a profound effect on medullary net Na transport.


Multifactorial analysis of chronic hypertension induced by electrolyte-active steroids in trained, unanesthetized dogs.

Chronic hypertension has been produced in mongrel dogs by the long-term oral administration of metyrapone (100 mg/kg per day). This model is characterized hemodynamically by wide variations in cardiac output and extracellular fluid volume and metabolically, by hypokalemia, suppressed plasma renin activity, and elevated plasma deoxycorticosterone values. Unlike the deoxycorticosterone acetate (DOCA)-saline hypertensive rat, it is associated with decreases rather than increases in plasma catecholamines. Reasons for the raised arterial pressure induced by metyrapone were sought (1) by exploring the role of cardiac output in the initiation and maintenance of hypertension, (2) by an assessment of neural contribution through the study of circulating catecholamines and use of adrenergic blocking drugs, and (3) by determining its relation to dietary sodium. The rise in pressure was not uniformly associated with an increase in cardiac output nor did prevention of rises in output by beta-blockade prevent the development of hypertension. Similarly, pretreatment with either centrally acting (clonidine) or peripherally acting (guanethidine) adrenergic blocking drugs failed to prevent the hypertension or change its pattern. In contrast, salt deprivation was singularly effective in preventing the rise in arterial pressure while increased salt intake led to parallel elevations in both blood pressure and peripheral resistance. These results point to a primary role of arteriolar resistance in determining the initiation and maintenance of hypertension induced by electrolyte-active steroids. In this regard, they agree with other reports of early changes in both membrane and structural properties of vascular smooth muscle that antedate the rise in pressure induced by DOCA and 1% saline.


Caretaking in the first year of life: the role of fathers, and mothers' social isolation.

Data are presented from a follow-up study of some 80 normal first or second born children on the extent of father participation childrearing. Though at both 30 and 60 weeks most fathers played regularly with their children, only a minority regularly undertook care-taking activities. Fathers were more participant at 60 weeks than 30 weeks especially with their daughters. No clear social class differences were found. The number of visitors to the home and excursions by mothers showed that social isolation during the day was quite widespread. Social class I and II families were less likely to have relatives in the neighbourhood and so received fewer visits and went out less often. Mothers going out without children showed less marked social class differences. Mothers of children who woke regularly at night and showed more 'difficult' behaviour went out without their children less often than the mothers of children not classified in this way.


Structural and functional changes in vascular resistance and reactivity in the deoxycorticosterone acetate (DOCA)-hypertensive pig.

The development of altered vascular resistance and reactivity was characterized in a new model of hypertension, the deoxycorticosterone acetate (DOCA)-hypertensive pig. Terminal hindlimb perfusion studies were carried out on pigs (young uninephrectomized males) approximately 50 days after implantation of DOCA or control Silastic strips. Data from these studies showed that hypertensive vascular beds (n = 5) had significantly greater (P less than 0.005) resistances than controls (n = 9) both before and after maximla vasodilation with papaverine. In response to intra-arterial injections of norepinephrine, hypertensive pigs (n = 8) demonstrated shifts in the dose-response curves to the left and lower vasoconstrictor thresholds than controls (n = 10). Preliminary observations have been made on the effects of "protecting" the hindlimb vascular bed from the increased arterial pressure by external iliac artery ligation. Although this "protection" was incomplete it prevented the development of structurally based changes in resistance and reactivity, but did not prevent the development of increased vascular smooth muscle sensitivity. It is concluded that resistance vessels in the DOCA-hypertensive pig demonstrate changes in both structure and function; structural changes do not occur when the vessels are partially protected from the increased wall stress but this does not prevent the increase in sensitivity. The structural component of resistance makes a greater contribution to the overall increase in resistance in this stage of hypertension than does the smooth muscle contraction; however, since the structural change is secondary to the increase in arterial pressure, it cannot initiate the hypertension.


Specificity of altered electrogenesis of membrane potential in hypertension.

Cardiac and hepatic portal venous muscle were used in an attempt to determine the specificity of the altered membrane potential (Em) electrogenesis found in caudal artery of spontaneously hypertensive rats (SHR). Neither the sensitivity to norepinephrine nor the electrogenesis of Em was found to be different in SHR than in their normotensive controls. Thus, ventricular myocardium and portal venous myovascular cells do not show either the increased sensitivity or the Em factor proposed as a contributor to it. A second determination of specificity was stimulation of the caudal artery by Ba2+. Both depolarization and extent of contraction were no different in SHR than in normotensive controls, suggesting that the increased sensitivity of arterial muscle does not extend to all depolarizing agents. These data define the electrogenesis of Em in cardiac and portal venous muscle of SHR and their controls and provide a test of the hypothesis that altered Em electrogenesis contributes to increased arterial norepinephrine sensitivity seen in hypertension. The data support rather than refute the hypothesis, i.e., the Em alteration was specific for both the muscle showing increased sensitivity and the agent used for depolarization.