Studies on the pathogenesis of bovine ephemeral fever.

A study of the pathogenesis of bovine ephemeral fever confirmed that the major clinical signs were fever lasting no more than 2 days, with increased respiratory rate, dyspnoea and some degree of lameness. Haematological observations revealed a neutrophilia with a left shift and a lymphopaenia at the time of peak clinical reaction. The net result was a slight leucopaenia on the day after this reaction. The most prominent pathological changes involved the lungs and synovial joints. Pulmonary emphysema and alveolar collapse with bronchiolitis, degenerative changes in synovial membranes and increased synovial fluid were observed. Specific fluorescence indicating the presence of BEF viral antigen could be detected at the time of peak clinical response in individual cells in the lungs, spleen and lymph nodes as well as neutrophils. Before and after the peak fever some fluorescence was seen in cells which appeared to be reticular cells in the lymph nodes. Viral isolation in mice could be made from blood, lungs, spleen and lymph nodes over a period of no more than 3 days. It is postulated that viral growth takes place mainly in the reticuloendothelial cells in the lungs, spleen and lymph nodes and not in vascular endothelium or lymphoid cells.


Factors affecting the formation of alkaline phosphatase isozymes in Escherichia coli K-12.

Physiological and genetic factors affecting the formation of isozymes of alkaline phosphatase in Escherichia coli K-12 were studied. Our results are compatible with the hypothesis proposed by Schlesinger and his co-workers (Schlesinger et al., 1975) that the multiple forms of the enzyme are produced by converting a newly synthesized one (the least negatively charged one) into less negatively charged forms. Neither energy source nor de novo synthesis of the enzyme was necessary for the conversion. It is also confirmed that the conversion is effectively inhibited by externally added arginine (Piggott et al., 1972) but only partially by canavanine (arginine analog) or casamino acids. We isolated a mutant strain which did not form isozyme(s), if any, under the condition in which the wild type strain formed isozymes. The mutation(s) was proved to be mapped in the locus (or loci) other than alkaline phosphatase structure gene in the E. coli genetic map. We tentatively proposed to designate this the iap gene(s), an abbreviation for isozyme of alkaline phosphatase, which plays a role in isozyme formation.


Studies on pyrogenic tolerance to bacterial lipopolysaccharide in rabbits.

The development of pyrogenic tolerance was studied in rabbits treated with varying doses of E. coli lipopolysaccharide (LPS). The following results were obtained. 1) Development of pyrogenic tolerance seemed to proceed in two steps: that is, the first in which tolerance appeared rapidly and the second in which tolerance proceeded more gradually or steadily in response to repeated injections of a constant dose. 2) Tolerance induced by the latter method was not absolute; the rabbits were still sensitive to increased doses of LPS. 3) Rabbits immunized with E. coli vaccine lost their pyrogenic sensitivity of parent LPS to some extent. 4) Following intracisternal injection of LPS into tolerant rabbit, pyrogenic response was not decreased but rather enhanced in comparison with control. 5) The contents of nor-epinephrine and serotonin in the brain did not differ between normal and tolerant rabbits. 6) The mechanisms of endotoxin tolerance remain to be further studied.


Use of isoelectric focusing and a chromophoric organomercurial to monitor urea-induced conformational changes of yeast phosphoglycerate kinase.

The effects of urea in concentrations from 0 to 6M on the following properties of yeast phosphoglycerate kinase were studied: the kinetics of inactivation of the enzyme, the spectrum of 2-chloromercuri-4-nitrophenol bound to the single thiol group of the enzyme, the rate of reaction between the mercurial and enzyme, and the isoelectric point. The enzyme was inactivated by as much as 30% in 1M-urea, and the other data were interpreted as a possible 'tightening' of enzyme structure. The catalytic behaviour of the enzyme in 2M-urea was time-dependent, the initial effects being similar to those in 1M-urea. Polyacrylamide-gel isoelectric focusing of the enzyme in the presence of 2M-urea showed a single species of enzyme with an isoelectric point intermediate between those in 1M- and 3M-urea; a species with an identical isoelectric point was obtained after an 11-day exposure at 4 degrees C to the denaturant at 2M. The enzyme was rapidly inactivated in 3M-urea, with the thiol group fully exposed and the isoelectric point 0.9pH unit higher than in the absence of urea. No further conformational changes could be demonstrated with urea concentrations of 4M or greater. It is suggested that the equilibrium species that exists in 2M-urea has one of two buried lysine residues exposed. The second lysine residue is exposed in 3M or greater concentrations of the denaturant.


[Dwarfism due to familial panhypopituitarism].

Three sisters of 27 7/12, 13 8/12 and 9 1/12 years of age, respectively, with proportionate dwarfism, high pitched voice and lack of sexual development are described. All the patients had very low serum levels of immunoreactive growth hormone (GH), as well as of LH and FSH. Hypoglycemia induced by insulin and arginine infusion failed to increase GH levels, and the administration of the hypothalamic LH-FSH releasing hormone (LH-RH) did not elicit any response in the secretion of gonadotropins. The oldest sister developed hypothyroidism in recent years, since the I131 thyroid uptake was normal ten years before; her serum TSH was low and did not change with TRH stimulation. In addition, a low pituitary ACTH reserve was demonstrated by the hypoglycemia and metirapone tests. Case 2 showed partial pituitary TSH and ACTH reserve, whereas the youngest child only had low TSH pituitary reserve. These patients had all the clinical and laboratory characteristics of familial panhypopituitarism, with normal sella turcica. Genetic transmission in this cases is consistent with the autosomal recessive form, which is the most frequent type of inheritance of this entity. Consanguinity can not be ruled out. The results of the hypothalamic-pituitary functional tests apparently suggest that the primary defect could be located at the pituitary level. It is also possible that the pathological process may have a progressive evolution.


Effect of testosterone cypionate on postexercise ST segment depression.

A randomised double blind study was carried out with 50 men who had ST segment depression of 0.1 mV or more after a modified two-step exercise test. Rate and duration of exercise were the same for the last of each  subject's several pretreatment tests as for his tests after 4 and 8 weeks of treatment with placebo or testosterone cypionate, 200 mg, intramuscularly weekly. The sum of ST segment depression in leads II, V4, V5, and V6 taken immediately, and 2, 4, and 6 minutes after exercise did not change significantly after 4 or 8 weeks of placebo treatment, but did decrease by 32 per cent (P less than 0.0001) and 51 per cent (P less than 0.0001) after 4 and 8 weeks, respectively, of testosterone cypionate treatment. The mechanism by which testosterone cypionate treatment results in lessened postexercise ST segment depression is not established.


Comparison of nefopam and pethidine in postoperative pain.

A double-blind, between-patient, two-dose comparison was comparison was performed with pethidine and nefopam in 100 subjects, the majority of whom were recovering from upper abdominal surgery. Either 15 or 30 mg of nefopam or 50 or 100 mg of pethidine were given by i.m. injection in a random order. All assessments were made by the same observer on the first day after operation, at least 4 h after the previous analgesic injection. Nefopam 15 mg was equipotent with pethidine 50 mg, peak analgesia being achieved 1 h after the i.m. injection. Pethidine 100 mg provided significantly better pain relief than nefopam 30 mg, the latter being not more effective than nefopam 15 mg apart from the duration of analgesia which was longer. The incidence of nausea and vomiting was similar after both drugs. Sweating and tachycardia were observed more frequently after nefopam, whereas sedative side-effects were more common after pethidine.


Analgesia after operation. A controlled comparison of meptazinol, pentazocine and pethidine.

In a double-blind investigation of the efficacy on pain following abdominal or orthopaedic surgery, meptazinol 100 mg, a new hexahydroazepine derivative, was found to be equipotent with pentazocine 60 mg and pethidine 100 mg when given i.m. Analgesia was maximal 30-60 min after injection and was still present at the end of 2 h. The duration of action of meptazinol was estimated to be 4 h. Meptazinol produced less sedation and a greater sparing of lung function tests than did pethidine and pentazocine. When meptazinol or morphine was administered for further pain relief in a single-blind manner there was no evidence of patient preference for one drug or the other.


A controlled clinical trial of oral droperidol and droperidol plus diazepam for premedication in children.

In 87 children aged 2-9 yr, oral droperidol and oral droperidol plus diazepam were compared as premedicants in a controlled double-blind clinical trial. Atropine was given orally to all the patients. Droperidol was well absorbed and produced good sedation, associated with a low incidence of vomiting after operation. Droperidol plus diazepam did not appear to offer any advantage over droperidol alone. Anxiety and extrapyramidal effects were not observed and may have been obviated by the addition of atropine. Droperidol syrup was noted to be more palatable than other oral premedicants in use.


Effects of varying inspiratory flow waveform and time in intermittent positive pressure ventilation. I: Introduction and methods.

A general review of the physiological alterations with artificial ventilation is presented with particular emphasis on the alteration of inspiratory time and flow waveform. The general methods and physiological calibration procedures used in a more elaborate study of inspiratory time and waveform effects are described, with the results of testing these methods showing that the model is satisfactory.


Effects of varying inspiratory flow waveform and time in intermittent positive pressure ventilation. III: Blockade of the autonomic nervous system.

The autonomic nervous system was blocked in dogs which were exposed to independent alterations in inspiratory flow waveform and time whilst being ventilated artificially at a constant volume and frequency. There were statistically significant differences in cardiac output between the control and blocked states, but these differences were not of marked physiological significance. Alteration in inspiratory waveform or time in the blocked animals did not alter cardiac output significantly.


A comparison of the effect of three anaesthetic techniques on postoperative arterial oxygenation in the elderly.

Ninety patients (age range 49--99 yr) with a fracture of the neck of the femur were anaesthetized by a technique using halothane in oxygen in a closed circuit, halothane and 66% nitrous oxide in oxygen in a Magill circuit or artificial ventilation with 66% nitrous oxide in oxygen ("IPPV group"). In all three groups, there was a small decrease in PaO2 from an overall mean of 9.07 kPa before operation to 8.13 kPa at 60 min after anaesthesia. There was no significant difference between the groups in respect of the decrease; it was concluded that closed-circuit halothane in oxygen anaesthesia for this type of surgery was not accompanied by a significant degree of absorption collapse.


Experience with the use of a corticosteroid aerosol.

1. In 48 patients with chronic asthma who had been receiving treatment with beclomethasone dipropionate aerosol (BDA) at a daily dose of 400 microgram for several years, observations were made on the effect of increasing the dose to 800 microgram daily for 6 months. 2. There was subjective improvement in 37 of the 48 patients, but the only objective evidence of improvement was a slight reduction in airways resistance. 3. The higher dose of BDA did not produce impairment of pituitary-adrenal function or an increase in the incidence of oropharyngeal candidiasis.


Long-term results with beclomethasone dipropionate aerosol in children with bronchial asthma: why does it sometimes fail?

1. Beclomethasone dipropionate aerosol has been shown to be a highly effective treatment for asthma in childhood, with virtual absence of side effects at this age. 2. When treatment is unsuccessful, this is usually due to failure to take it correctly and regularly. 3. A good response is usually associated with an improvement in ventilatory function and a marked increase in growth velocity.


Experience of the use of beclomethasone dipropionate aerosol in general practice.

1. The findings of an open trial of beclomethasone dipropionate aerosol (BDA), carried out in 1972 in the author's general practice, are discussed in the light of subsequent, more extensive experience of its use of BDA. 2. An important reason why BDA may be unsuccessful in controlling asthma, and may give rise to various problems, is that patients are often given an inadequate explanation of the purpose and proper use of this treatment.


Beclomethasone dipropionate aerosol in treatment of perennial and seasonal rhinitis: a review of five years' experience.

1. Five years' experience in the use of beclomethasone dipropionate aerosol (BDA) in the treatment of 315 patients with upper respiratory tract allergy is reviewed. 2. A total of 223 patients with perennial rhinitis was treated. In 23, where the nasal allergy had recurred after oral corticosteroid therapy for asthma was withdrawn, BDA was effective in 69% of cases. A similar success rate (68%) was recorded in 169 patients suffering from perennial allergic rhinitis alone, but a satisfactory response was observed in only 45% of 31 patients with nasal polypi. 3. In 92 patients with seasonal allergic rhinitis freedom from symptoms was achieved in 80%. 4. A total of approximately 534 patient-years of treatment has been recorded without any evidence of side-effects either clinically or on nasal biopsy.


Immunological investigations of Candida albicans in respiratory disease.

1. Tests against rabbit antiserum to Candida albicans showed about 40 protein antigens in cytoplasmic extract compared with two in a commercial test extract, which contained mainly polysaccharide (mannan) antigens. 2. Positive precipitin tests to the mannan preparation were recorded in 40% of 56 asthmatics on systemic corticosteroids and 37% of 56 rhinitis patients not so treated. The titres were slightly higher in the corticosteroid group. There was no increase in precipitins over 0-9 months in asthmatics treated with beclomethasone dipropionate aerosol (BDA) by inhalation, or over 0-12 months in rhinitis patients treated with BDA nasal spray. No positive reactions to the purified protein fraction were recorded. 3. Radioallergosorbent tests for specific IgE antibody showed a higher incidence of positive results with whole C. albicans yeast cells than with purified cytoplasmic protein. There was a higher incidence of positive results to protein in patients on systemic corticosteroids than in the other patients. No change in incidence occurred in asthmatics on BDA. The number of positive results in 56 rhinitis patients increased on BDA from 28 to 37 for yeast cells, and from 7 to 16 for cytoplasmic protein. This was attributed to C. albicans challenge tests. 4. Specific IgA antibodies to yeast cells were detected in 48/56 asthmatics on systemic corticosteroids, and there were no significant changes over 0-9 months on BDA. The corresponding figures for rhinitis patients were 25/56, and again there were no significant changes over 0-12 months on BDA.


Selection of an in vitro carcinogenicity test for derivatives of the carcinogen hexamethylphosphoramide.

The demonstration that hexamethylphosphoramide (HMPA) possesses potent carcinogenic properties has raised doubts about the safety of exposure to other phosphoric amides. In order to define a suitable short-term test with which to evaluate such analogues, the response of the Salmonella typhimurium mutation assay of Ames and cell transformation assay of Styles to HMPA and 3 selected analogues has been studied. These analogues were the related leukaemogen phosphoramide, the putative non-carcinogen, phosphoric trianilide and N.N'N''-trimethylphosphorothioic triamide, a compound of unknown and hitherto unpredictable properties. While both tests found the trianilide negative, the Ames test failed to detect phosphoramide as positive and gave an erratic and predominantly negative response to HMPA. In contrast, the transformation assay found both phosphoramide and HMPA positive. This test response profile indicates that the transformation assay is the preferred test with which to evaluate analogues of HMPA for potential carcinogenicity. Some structural requirements for potential carcinogenicity within this class of compounds are tentatively deduced.


Localization of carcinoembryonic antigen in medullary thyroid carcinoma by immunofluorescent techniques.

Cellular localization of carcinoembryonic antigen (CEA) in medullary thyroid carcinoma was studied in ethanol-fixed, paraffin-embedded specimens using the direct and indirect immunofluorescent techniques. It was demonstrated that CEA was present not only on the surface, but also in the cytoplasm of tumour cells. The immunofluorescence in the cytoplasm differed considerably in intensity from cell to cell. By contrast, no significant fluorescence was demonstrated in tissues of other types of thyroid adenocarcinoma, adenoma. Graves' disease and normal thyroid, with few exceptions. The results obtained indicate that CEA is actively produced by the tumour cells, and is present as a constituent of the cell membrane.


Betamethasone valerate inhalation and exercise-induced asthma in adults.

The effect of regular inhalation of betamethasone valerate (800 microgram daily) on exercise-induced asthma has been studied in 18 adult patients. The active aerosol was compared with placebo in a double-blind cross-over study, each inhaler being used for four weeks. Exercise tests after each period of treatment were performed using a cycle ergometer, care being taken to match the oxygen uptake during exercise each time a patient was tested. Twelve patients experienced less exercise-induced fall in peak expiratory flow rate after the corticosteroid inhaler, while six did not. This effect appeared to be independent of any alteration in base-line lung function, suggesting that it was due primarily to diminution of bronchial hyperreactivity. It is suggested that this change may have been due to interference with the synthesis or release of mediator substances from mast cells.


The migrating mycetoma.

A case of mycetoma is presented in which the fungus ball migrated from the apex to the base of the lung as a result of progressive parencyhmal destruction by tuberculosis. Histological and serological data suggested Aspergillus fumigatus as the cause of the mycetoma. Aspergillomas rarely coexist in cavities with active tuberculosis.


Aerobic and anaerobic mixtures of human pathogens: a rapid 4-plate counting technique.

A reliable, cheap, labour-saving technique is presented for counting viable organisms in mixtures of aerobic and anaerobic human pathogenic bacteria. Series of 0.1-ml blood agar droplets containing antibiotics are used and only 4 Petri dishes are required. A system of controls makes recognition of any errors of technique particularly simple whilst allowing direct subculture of any unexpected colonies.


The migrant cells in allotransplants of heart, kidney and skin. II. Monocyte-macrophage activity.

Within a few hours of transplantation the cells of the mononuclear phagocyte system migrate into the interstitial tissues of the organ. The cells arrive on the vascular endothelium of the allotransplanted organ either as macrophages or as monocytes but on entering the interstitial tissues they begin to enlarge, differentiate and undergo active pinocytosis. Along with the cell migration, which would appear to be their stimulus to migrate, is an extravasation of the protein-rich plasma. Erythrocytes also pass into the interstitium and, if effete, are contracted by monocyte-macrophages and phagocytosed in the classical manner. All through the natural history of an allotransplant new monocyte-macrophage recruits arrive the interstitial tissues of the allotransplant. Some of these cells escape via the lymphatics but the vast majority accumulate in the allotransplant, interdigitate and fuse with one another but make no attempt to damage the tissues into which they have migrated. The reaction to an allotransplanted organ fits into the category of an aseptic inflammatory reaction and the only obvious role played by the mononuclear phagocyte system is the classical role of scavenging interstitial debris.


Delayed hypersensitivity to Escherichia coli in the rat--a study of its possible relevance to the pathogenesis of kidney scars.

Rats sensitized to various strains of Escherichia coli (078, O2K13H1, O6K13H1 and O6K2a2cH1) showed cutaneous delayed type hypersensitivity (DTH) reactions after intradermal challenge with the same or a different strain of Esch. coli. Cutaneous DTH was transferred to non-sensitized rats by administration of lymphocytes from sensitized animals. The common antigen(s) responsible for DTH was not identified but DTH reactions were found to be unrelated to the O or K serotype of the Esch. coli strains used. Intrarenal administration of killed Esch. coli to animals showing cutaneous DTH and non-sensitized controls did not produce evidence of DTH reactions of the kidney. Instead it was shown that intrarenal administration of formalin- or heat-killed Esch. coli leads to kidney scarring in both sensitized animals and non-sensitized controls. These scars were comparable in severity, and were similar to those obtained after infection of the kidney with live organisms. It is concluded that DTH reactions do not play a role in the pathogenesis of kidney scarring associated with Esch. coli infection of the rat kidney but that the strains of Esch. coli studied possess a common heat- and formalin-stable nephrotoxic factor which induces kidney scarring.


Lymphocyte activation by streptococcal antigens in psoriasis.

Cell-mediated immune responses in 28 hospitalized patients with psoriasis and in 36 healthy controls were studied using the two-step leukocyte migration agarose test. Specific cell-mediated immunity to A-streptococcal cell wall and cell membrane antigens occurred significantly more often in patients with psoriasis than in the control group. A statistically significant correlation between psoriasis-associated antigens of the HLA-B locus and cellular immune reactivity to A-streptococcal antigens or clinical course was not found. When patients with guttate psoriasis were compared separately with the control group, leukocyte migration inhibition induced by cell-free supernatants of A-streptococcal antigen-exposed mononuclear cell cultures was found to be more frequent than in other forms of psoriasis.


Intravenous oxytocin and oral prostaglandin E2 for ripening of the unfavourable cervix.

A clinical trial involving 60 patients was conducted to assess the relative efficacy of intravenous oxytocin and oral prostaglandin E2 in ripening the unfavourable cervix, when given as a priming dose on the day before induction of labour. There was significant improvement in the Bishop score, and the subsequent induction-delivery interval following priming with prostaglandin. This improvement appeared to be dose-related.


Radioisotope dilution technique for measurement of blood loss associated with lower segment caesarean section.

Using a 51Cr-labelled red cell dilution technique, the blood loss associated with elective lower segment Caesarean section was measured in 30 patients, half of whom had a previous history of Caesarean section. The blood loss (mean +/- SD) was 1290 +/- 240 ml for first Caesarean sections and 1012 +/- 380 ml for repeat operations.


The effect of treatment with oestradiol and oestriol on fasting serum cholesterol and triglyceride levels in postmenopausal women.

The effect of natural oestrogens on serum cholesterol and serum triglyceride levels was studied in a controlled double-blind clinical trial. No statistically significant changes were found in the blood lipids when comparing the patients treated with oestradiol, 2 mg, and oestriol, 1 mg, and those given placebo.


A double-blind trial of single-dose chemoprophylaxis with co-trimoxazole during total abdominal hysterectomy.

Thirty patients received 10 ml co-trimoxazole and 29 a placebo by intravenous infusion during one hour from induction of anaesthesia for total abdominal hysterectomy. The incidence of postoperative urinary tract infections was significantly lower in patients who had received co-trimoxazole. Co-trimoxazole was also found to inhibit postoperative colonization of the upper vagina with Escherichia coli. The incidences of postoperative pyrexia (38 degrees C or over) and both early and late abdominal wound abscess formation were almost identical in the two groups of patients.


External ocular motor palsies in ophthalmic zoster: a review.

Seventy-seven new patients suffering from ophthalmic zoster and a selected group of 69 old patients were carefully examined with regard to external ocular movements. An incidence of 31% of ocular pareses was found in the new patients, and 58 in all were analysed. We were surprised to find several of these were contralateral and bilateral palsies. 28% of the palsies were asymptomatic, due to diplopia being present only in extremes of gaze and the rapid development of suppression in the affected eye. The theories of aetiology of these pareses are discussed.


Accumulation of immunoglobulin messenger ribonucleic acid in immunized mouse spleen.

We have measured the concentration of mRNAs coding for immunoglobulins, k and lambda type light chains and gamma 1 type heavy chain, in mouse spleen cells activated by bacterial lipopolysaccharide or sheep red blood cells. These mRNAs were quantitated by hybridization to radioactive DNA complementary to highly purified immunoglobulin mRNAs from mouse myelomas. In the lipopolysaccharide-stimulated spleen cells, only light chain mRNA accumulated, whereas gamma 1 type heavy chain mRNA remained unvaried. The light chain mRNA concentration also increased in purified bone-marrow-derived lymphocytes. The lipopolysaccharide-induced light chain mRNA was similar to light chain mRNAs purified from myelomas. The accumulation and disappearance of light chain mRNA in bone-marrow-derived lymphocytes coincide with the kinetics of synthesis of immunoglobulin M which is the major species induced by lipopolysaccharide. In sheep red blood cell stimulated spleen, the specific accumulation of k type light chain and gamma 1 type heavy chain mRNAs parallels immunoglobulin G synthesis. These results seem to indicate that the increment of immunoglobulin mRNA concentration in bone-marrow-derived lymphocytes is important for induction of immunoglobulin synthesis.


Heavy meromyosin binds actin with negative cooperativity.

The association of fluorescently labeled heavy meromyosin (HMM) and F-actin was measured by time-resolved fluorescence depolarization. The effects of varying the protein concentrations, temperature, KCl concentration, and pH were determined. Measurements of HMM mobility supported a model of no interaction between the two heads in the absence of actin. Measurements of actin binding, when compared with results for myosin subfragment I, indicated that the two heads of HMM do not bind independently in the rigor complex. This could result from actin-transmitted negative cooperativity or from steric inhibition due to the structure of HMM. For HMM and actin in 0.15 7 kcl at 25 degrees C: Ka = 3.9 X 10(7) M-1, deltaHco' = 36 +/- 2 J M-1, deltaSco' = 0.26 +/- 0.02 kJ M-1 K-1; the slope of ln Ka vs. [KCl]1/2 = -3.88 and the pH of maximum association was 6.9.


Acid-labilization of sterols for extraction from yeast.

A wild type strain of yeast, Saccharomyces cerevisiae, pretreated with a mild acid hydrolysis, exhibited a 4-fold increase in sterol yield upon saponification and extraction. This increased yield is reflected in both major and minor sterols (ergosterol; zymosterol) and sterol esters.


[Planar model of nucleosome and chromatin structure of high orders].

A model of nucleosome is discussed, which consists of two nucleohistone strand folds, located at the same level, similarly directed and having a rhomboid form. The folds are symmetric to each other. Four histones (H3, H2a, H2b and H4) take part in the formation of each fold. Nucleosome begins with a DNA region, bound with H1 histone and terminates with free DNA. Total sequence of histones along DNA is H1-H3-H2a-H2b-H4-H4-H2b-H2a-H3. Polypeptide chains of neighboring histones are oppositely directed and are located at opposite DNA strands. The model explains regularities of chromatin splitting under combined effect of ds-nucleases and trypsin, and of ss-nucleases. It is also in a good agreement with other properties of chromatin. Nucleosomes join to each other "side-to-side" under coincidence of terminal elements with faces of the rhomboid nucleosome structures. The model permits to explain the formation of a highest order structure--a helix of six nucleosomes, forming a fibril of 250--300 A in diameter. The degree of DNA compactness in it reaches 80--100.


[Membrane action of ionic surfactants on yeast cells].

Effect of a number of homologous series of cationic and anionic surfactants on yeast cells was examined. It is found that the cellular proteins extraction degree under the surfactants treatment depends on the agents structure. It is established that the highest extraction efficiency among the bisquaternary ammonium compounds is displayed by the decyl derivatives and among sodium alkyl sulfates--by octyl sulfate. The influence of pH, ionic strength and the agent concentration on the proteins extraction degree was studied. It is concluded that the anionic and cationic compounds act on the yeast plasma membrane by the similar way and all the differences observed are just the quantitative ones. It is suggested that the efficiency of the surfactant action on the cell is limited particularly by the ratio of cell wall pore size to the size of micelles formed by the agent in the solution.


EEG profile and behavioral changes after a single dose of clozapine in normals and schizophrenics.

Clozapine, a powerful neuroleptic with unique clinical efficacy (and without parkinsonic side effects), has been shown to have an unusual EEG profile. The EEG changes after clozapine, especially when instrumentally quantified, demonstrated the predictive value of EEG. The similarities of the EEG profile of clozapine with the profile of thymoleptic compounds indicated its possible thymoleptic effect. This later proved to be the case with therapeutic studies in depression. The EEG profile of clozapine in volunteers is similar to the EEG profile in schizophrenics (with appropriately higher doses). Instrumental quantification was performed with spectral and iterative interval analysis to show the advantages of each method and also the complementary value of both of them.


Individual differences in habituation of human physiological responses: a review of theory, method, and findings in the study of personality correlates in non-clinical populations.

Studies up to 1976 of the relationship between psychometrically defined dimensions of personality and individual differences in habituation of EEG and autonomic responses were examined. Attention was confined to reports employing persons who were not diagnosed as suffering from mental disorder, institutionalized for this reason of for delinquent or criminal behaviour. The dimensions of extraversion and anxiety were most frequently found to be implicated in predictions about individual differences in response habituation, though no consistent rationale for these predictions was identified. Methodological problems involved in studying the predictions were considered, and a number of factors relating to measurement of personality and habituation and the experimental conditions under which response habituation is studied were suggested as possible sources of confounding. A survey of the empirical literature led to the conclusions that anxiety as defined by the Manifest Anxiety Scale is related to habituation of the finger vasomotor response but probably not to habituation of the electrodermal response, while extraversion, as defined by Eysenck's scale, is related to habituation of the electrodermal response. For other scales and other dimensions, including cognitive factors, the available data are inconsistent or too meagre to permit conclusions being drawn. It is suggested that future research be directed to a systematic investigation of the conditions under which personality factors contribute significantly to individual differences in response habituation, rather than seek to identify general relationships.


Applications of the Mantel-Haenszel statistic to the comparison of survival distributions.

In comparing two survival distributions, a Mantel-Haenszel statistic can be computed after each death as a non-linear two-sample rank statistic. The distributions of both the maximum and terminal statistics in such a sequence are studied numerically, in the absence of censoring, and appropriate critical values are determined. The maximum statistic is applied to simultaneous inference, and both the maximum and terminal statistics are used as the basis for early stopping procedures (especially in the pseudo-sequential context). Procedures based on the two statistics are compared for power and for early decision properties such as stopping index and (for exponential distributions) stopping time.


Sequential allocation in clinical trials comparing two exponential survival curves.

The problem of comparing two medical treatments with respect to survival is considered. Treatment outcome is assumed to follow an exponential distribution. The ratio of expected survivals associated with the two treatments is the clinical parameter of interest. A nuisance parameter is present, but it is removed by an invariance reduction and a sequential probability ratio test is applied to the invariant likelihood ratio. A class of data-dependent treatment assignment rules is identified over which the probability of correct treatment selection at the termination of the trial is approximately constant. A cost function, the weighted sum of total patients in the trial and the number assigned to the inferior treatment is introduced, and a treatment allocation rule conjectured to minimize the expected cost is constructed. Both analytic and simulation results show that it is an improvement over rules previously proposed. The methodology contained herein can be used to construct near-optimal rules in other testing contexts.


Adaptive treatment assignment methods and clinical trials.

This paper provides a general review of adaptive experimental designs which utilize accumulating information for assigning the best treatment to the most patients in clinical trials. The historical development of such methods is traced. Though the statistical literture on adaptive designs has developed rapidly and continues to grow, the methods are almost totally unused in practice. An extensive evaluation of why adaptive designs are rarely used in clinical trials is presented. It is asserted that most published methods have important deficiencies that render them unsuitable for application. Suggestions are offered for reorienting this area of research into directions that are potentially more useful for clinical trials.


Obtaining hyperimmune anti-coli (anti-Escherichia) human plasma.

Anticoli (anti-Escherichia) plasma has been obtained from donors immunized with viable Escherichia oral vaccines, prepared from Str-d mutants of E. coli. Anticoli plasma has an therapeutic effect against diseases of Escherichia etiology.


Hemolysis due to gram-negative urinary tract infection.

Twenty-four infants 8--62 days of age with urinary tract infection have presented with a chief complaint of jaundice. The bilirubin determinations have ranged from 6--48.2 mg/dl, with elevation of both the direct and indirect reacting bilirubin fractions except for the youngest infants (under 10 days old), where only indirect bilirubin elevation was present. The BUNs ranged from 18--153 mg/dl with general correlation to the bilirubin elevation. Hemolysis was documented in 21 infants. The infecting organisms were predominantly Escherichia coli (20 patients) of the low-number serotypes. We have been able to test 11 of the isolates and have found that all produced hemolysis on blood agar plates. Another interesting observation has been the reversal of the expected frequency of the A and B blood groups in our series. There is an excessive number of infants of blood group B with a paucity of blood group A; blood group O is as expected. The relationship of blood group type and E. coli infection and the presence or absence of jaundice needs to be explored in a larger group of infants.


[Dopamine sensitive neurons of the arcuate region of the hypothalamus and their role in regulating the gonadotropic function of the pituitary].

The effect of the microiontophoretic application of dopamine (DA) into the arcuate region of the hypothalamus on the sensitivity of single neurons and on the plasma and hypophysis LH levels was examined at various stages of the estrous cycle. During the estrous cycle in rats there was no significant differences in the relative number of neurons showing activation and inhibition or non-responsive to DA. However, in the first half of proestrus (P) a significant increase in the number of neurons with the excitative reaction to the iontophoretic application of DA was observed. At all the stages of the cycle, except the second half of P, the excitative reaction of neurons correlated with increased LH level in the plasma. In the hypophysis only in diestrus-2 there was a significant increase of the LH level in response to the iontophoretic application of DA in the arcuate neurons of the hypothalamus.


[Influence of poly-A:U, dextran sulfate and yeast RNA on the colony forming ability of bone marrow in irradiated mice].

Poly-A:U, dextran sulfate and yeast RNA were shown to increase the number of endogenous (CFU) in sublethally (525 r.) irradiated mouse spleens seemingly as a result of their mutagenic effect on proliferating CFU. The preparations had no effect on the number of exogenous colonies when injected together with bone marrow syngeneic cells transfer from intact donors. Dextran sulfate led to a 2.7 time increase in the number of endogenous colonies in unevenly irradiated mouse spleens mostly due to the CFU migration from the protected sites of the bone marrow. Poly-A:U and yeast RNA complex was ineffective in such an experiment. It is quite possible that the ability of dextran sulfate to increase the migrational potencies of the stem hematogenic cells served as one of the essential factors in the mechanism of its adjuvant activity.


[Formation of recombinants of F' plasmids in recombination-defective E. coli cells and their properties].

As a result of mating of cells carrying plasmid F' lac with cells carrying plasmid F'his merodiploids carrying plasmid complex F'lacF'his were isolated. The plasmid genes of the isolated merodiploids are donated together into the recipient cells and are eliminated jointly from host-cells both spontaneously and by acridine orange. As the formation of the plasmid complex took place in E. coli cells carrying mutation in rec A gene the recombination of plasmids F' is supposed to take place in the absence of the product of gene rec. A.


[Method of exposing cells to ultrasound].

A simple chamber for studying the influence of ultrasound on low quantities of cell suspension is suggested. It consists of an organic glass cylinder, which is placed on the head of the apparatus YTP-1, the surface of which forms the floor of the chamber. Thanks to this, the loss of ultrasonic energy is eliminated, and a possibility of a rather exact determination of the intensity of ultrasound, which influences the suspension cells, is attained.


Purification and characterization of granulocytic progenitor cells (CFU-C) from human peripheral blood using immunologic surface markers.

The concentration of committed granulocytic progenitor cells (CFU-C) in functionally unique subpopulations of human peripheral blood mononuclear cells has been determined by the in vitro methyl-cellulose assay. Using immunoabsorbent column chromatography and rosette-depletion techniques, we have demonstrated that CFU-C, although not present in either purified T or B lymphocyte populations, are highly concentrated in the "null" cell population, which lacks sheep erythrocyte receptors and surface immunoglobulin. Further fractionation of this null subset has demonstrated that CFU-C do not bear complement receptors, but require the presence of peripheral blood mononuclear cell feeder layers for maximum proliferation.


Skin surface application of ketocaine to provide local anaesthesia for cutting split skin grafts.

Astra 2337 ketocaine-soaked pads applied to the skin surface produced analgesia adequate for split skin graft cutting 85 out of 86 patients. In 86 per cent, the analgesia was completely satisfactory; a few had some discomfort or pain but all could tolerate this. Application for 1 hour is time enough, but the effect lasts for at least 8 hours and probably longer. Apart from occasional redness and oedema of the skin, no adverse effects wer noted and the blood levels of absorbed ketocaine were far below the toxic level. This simple effective technique is of great value, particularly in such cases as burns who require multiple grafting operations and in whom repeated general anaesthetics can have such adverse effect.


Gustav Simon (1824-1876): Simonart (s)(z) of the band?

Gustav Simon was the first to describe how, in a bilateral hare lip, the premaxilla would move backwards when the clefts were closed. The reference invariably given for this is wrong. The "bands" which Simon Arzt created to bridge the clefts and pull back the premaxilla are almost certainly the origin of the term "Simonart's(s')(z') band.


Experimental micro-anastomosis of 0.4-0.5 mm vessels.

Ninety-two anastomoses of arteries 0.5 mm in diameter have been performed in rats with an 85-90 per cent patency rate in the second postoperative week. The factors of prime importance in the achievement of high patency rates have been atraumatic handing and meticulous suturing technique. At 1 hour and at 8 to 10 days the patency rates were not statistically different whether 20 per cent magnesium sulphate heparin or normal saline were used. Similar results were obtained with 40 repairs of divided veins averaging 0.4 mm in diameter. These results suggest strongly that clinical microvascular surgery in vessels approximately 0.5 mm in diameter, especially in children, should given results comparable to 1 mm vessel surgery.


The youngest free groin flap yet?

A successful free groin flap transfer to the arm in a 3-month-old baby is described. The vessels were large enough for microvascular anastomosis and we believe that there is no minimum age restriction for free flap transfer.


Surgical treatment of lymphangioma circumscriptum: a case report.

Lymphangioma circumscripta can only be reliably cured by excising not only the affected skin but all the subjacent subcutaneous tissue.


A trial of ascorbic acid in the treatment of the common cold.

A randomised controlled trial was carried out to study the effect of 10 g of ascorbic acid taken during the first 2 1/2 days on the symptoms of the common cold. Altogether 1524 volunteers were recruited from a number of working groups in different parts of the country; 482 developed colds. There was no evidence that upper respiratory or general constitutional symptoms were alleviated by ascorbic acid. Among the men who had any colds at all, significantly fewer on active than on placebo treatment had two or more colds; however, this effect was not seen in women. Ascorbic acid is of no value in the treatment of the common cold; its preventive effect, if any, is not such as to justify advising its general use as a prophylactic measure.


A clinical trial of phenelzine in anxiety depressive and phobic neuroses.

A double-blind clinical trial of phenelzine and diazepam against placebo and diazepam in neurotic patients over a four-week period showed phenelzine to be superior to placebo on three rating scales in some groups of patients who completed the trial. The findings suggest that phenelzine may exert a beneficial effect on some as yet undefined features of anxiety and depression which were not revealed by a multiple regression analysis of clinical symptomatology or premorbid personality.


Antidepressant drug therapy in psychotic depression.

Imipramine and phenelzine were ineffective in the treatment of five primary unipolar depressives with delusions, even when plasma levels of imipramine and desmethylimipramine or activity of platelet monoamine oxidase suggested that an adequate dose of drug had been given. Four patients went on to receive ECT and all responded well. Five non-delusional patients responded satisfactorily to the antidepressant drug given. Nine out of ten subjects were women. Non-delusional patients showed some placebo response. ECT is considered to be the treatment of choice in the acute phase of delusional depression in women.


Improvement in the computer-assisted diagnosis of cerebral tumours.

Most applications of Bayes theorem in computer-aided diagnosis have been to situations involving the differential diagnosis of a small list of disease categories. In the case of the diagnosis of cerebral tumours, if each tumour type in each main anatomical situation is counted as a single diagnosis, there are about 100 possible disease categories. This paper investigates a method of incorporating expert prior information into the computer-aided diagnosis process so that this large number of categories can be handled.


The use of double renal transplants from paediatric cadaver donors.

In 224 consecutive kidney transplantations, 3 patients, aged 44, 37 and 13 years received double renal transplants from paediatric cadaver donors aged 1 day, 23 and 19 months respectively. Both adult recipients developed severe hypertension during postoperative rejection crises leading to multiple graft ruptures in the recipient of the neonatal kidneys. 1 patient died from massive gastrointestinal bleeding 4 weeks after transplantation while kidney function was satisfactory. Excellent graft function was achieved in the 3rd patient. The techniques of removal, preservation and transplantation of double renal transplants are described. The significance of increasing the potential number of donor kidneys by the use of paediatric cadaver donors is stressed.


The use of a ureteric nipple alone for reflux prevention.

In the re-implantation of a ureter into the bladder, vesico-ureteric reflux can be prevented by a ureteric nipple alone, provided the nipple is at least 1.5 cm long. This eliminates the need for an oblique ureteric entry or a submucosal tunnel. Longer nipples may be used although they may lead to difficulties with catheterisation. Reduction in the length of the nipple frequently occurs later.


Clinical evaluation of the Makari test in urological malignancies.

The results of a double-blind controlled study of the modified Makari skin test for the detection of cancer are described. The test identified malignant disease in 95% of 37 patients with primary cancer and in 74% of 81 with recurrent cancer after the exclusion of "anergic" patients. The study suggests that the test will be useful in the monitoring of primary treatment and in the detection of recurrent malignancy.


Seasonal variation in the incidence of deep vein thrombosis.

Two double-blind controlled clinical trials of the effectiveness of prophylactic low dose subcutaneous calcium heparin (dose based on body weight) in the prevention of deep vein thrombosis (DVT) have been completed. The first was concerned with upper abdominal operations in 242 patients over 21 years of age, and the second with 50 patients presenting with a fracture of the neck of the femur. There was no increase in the incidence of bleeding or wound complications in the patients given heparin. In each trial, the incidence of DVT as diagnosed by 125I-labelled fibrinogen was significantly reduced in the treated group. The incidence of DVT in the control groups varied significantly during the period of the trials. The incidence was much higher in the cold half of the year than in the hot months. In the first trial, this variation in incidence was directly correlated with the average temperature and the diurnal variation in temperature in the perioperative period. These results may help to explain the considerable variation in the incidence of postoperative DVT reported from various parts of the world, and also from within Australia.


Hydrotalcite in the treatment of bile vomiting.

Seventeen patients have completed a double-blind cross-over study of hydrotalcite against placebo in the treatment of bile vomiting after surgery for peptic ulcer. Overall there was no significant difference between the two treatments, with 9 patients improving on hydrotalcite and 5 on placebo. The original operation had been peformed less than 3 years before the study in 9 patients; in this subgroup there was an improvement on hydrotalcite treatment in 8 patients but in only 1 on placebo. These differences are statistically significant (P less than 0.005). Nausea, vomiting, heartburn and epigastric tenderness were improved although gastritis and endoscopic changes were not affected. It appears that hydrotalcite can help palliate symptoms of bile vomiting occuring soon after surgery for peptic ulcer.


Wound implantation--A surgical hazard.

A review of the literature on wound implantation together with a report on an unusual case of implantation of squamous carcinoma at the site of a gastrostomy is presented.


A controlled comparison one- and two-layer techniques of suture for high and low colorectal anastomoses.

A controlled trial of one- and two-layer inverting techniques of sutures for the contruction of high and low colorectal anastomoses was conducted on 137 patients, the integrity of the suture lines being assessed clinically and by routine radiological examination after a small Gastrografin enema. A clinical diagnosis of anastomotic leakage was made in 9 patients (or perhaps more accurately in 5 only), but subclinical dehiscence was demonstrated radiologically in a further 39 patients (or perhaps 43). There was a slightly greater incidence of dehiscence after the one-layer technique of suture for both high and low anterior resection.


Knot properties of surgical silk: Model study.

The knot properties of surgical silk of different dimensions and from different manufacturers have been studied. Large variations were found. It is proposed that the differences are due mainly to the braiding technique. Only very few surgical silk sutures can be securely tied with a square (reef) knot today. A knot with three square throws is therefore recommended for modern surgical silk.


Prostaglandin-induced abortion and outcome of subsequent pregnancies: a prospective controlled study.

We analysed a prospective series of 204 pregnancies occurring in 168 women after a prostaglandin-induced abortion. The mean (+/-standard error of mean) interval between abortion and first subsequent conception was 10.4 +/- 0.6 months; no patient reported secondary subfertility.Fifty-five of the subsequent pregnancies were terminated, 23 during the second trimester, again using prostaglandins. Of the 149 pregnancies not terminated, 127 were delivered at term, and 19 spontaneously aborted, seven during the second trimester; there was one missed abortion and two ectopic pregnancies. Morbidity in the 127 term pregnancies was infrequent; spontaneous preterm labour occurred in three patients, and four singleton infants weighed less than 2500 g at birth. There was no apparent association between morbidity in the subsequent pregnancies and the period of gestation at the time of the previous abortion, route of prostaglandin administration, or need for post-abortion curettage.The results obtained overall were very similar to a control group of 612 women consecutively admitted for delivery or abortion to the Oxford obstetrical and gynaecological units. There was, however, an increased incidence of spontaneous abortion and placenta praevia after prostaglandin-induced abortion, and the multigravidae in that group had a longer average duration of labour than the control group. Sixty-five per cent of the post-abortion pregnancies were unplanned compared with 36% of the control group.


Acebutolol, atenolol, and propranolol and metabolic responses to acute hypoglycaemia in diabetics.

In a double-blind crossover study the symptomatic and metabolic effects of propranolol, acebutolol, and atenolol were studied during insulin-induced hypoglycaemia in diabetics treated with diet or hypoglycaemic tablets. All the drugs prevented tachycardia, but did not affect the other symptoms of hypoglycaemia. Propranolol delayed the recovery of the blood glucose concentration and impaired the secondary rise in the concentrations of blood lactate and non-esterified fatty acids in diet-treated diabetics. Acebutolol potentiated the hypoglycaemic effect of insulin in tablet-treated diabetics (mean difference of blood glucose concentration 0.7 mmol/l (12.6 mg/100 ml)) and this difference was maintained during the recovery phase4 the blood lactate response was also impaired. Atenolol did not differ perceptibly from placebo in its effect on the metabolic responses to acute hypoglycaemia. The results may be explained by differences in the known pharmacological actions of these drugs. They support the hypothesis that beta-adrenoreceptor blocking drugs that are highly beta1 specific and without membrane-stabilising activity should be safer than the non-selective drugs when used in diabetic patients at risk from hypoglycaemia.


Effect of oestrogen on the sleep, mood, and anxiety of menopausal women.

A double-blind controlled study of the effect of piperazine oestrone sulphate on sleep, depression, anxiety, and hot flushes was performed in 34 perimenopausal women. Half of the patients were given six weeks' placebo followed by eight weeks' oestrogen, and half remained on placebo throughout. Sleep was recorded electrophysiologically every week, and mood and anxiety were rated daily by means of visual analogue scales. Hot flushes were counted daily. Observer rating scales of anxiety and depression were complete at intervals. During the first month of active treatment the amount of intervening wakefulness in the first six hours of sleep decreased significantly more in the oestrone group than in those on placebo. Between the baseline period and the second treatment month the oestrone group showed a significantly greater decrease in the total amount of intervening wakefulness and in the frequency of awakenings. Their total amount of rapid eye movement sleep increased. Mood and anxiety improved and the number of hot flushes decreased to a similar degree in both groups. Although oestrogen did reduce the number of episodes of wakefulness in perimenopausal women complaining of insomnia, its effects on their psychological symptoms were little different to those of placebo.


Adjuvant liver perfusion in colorectal cancer: initial results of a clinical trial.

Fifty consecutive patients with colorectal cancer but no evidence of secondary deposits in the liver were included in an ongoing controlled clinical trial of adjuvant liver perfusion aimed at reducing the incidence of hepatic metastases. All patients had their primary tumour resected in the standard way. Twenty-six of the patients served as controls, and 24 received fluorouracil, 1 g daily, as a continuous infusion into the portal venous system during the first seven days after operation. The patients were matched for age, sex, and site and stage of the disease. The immediate postoperative mortality and morbidity did not differ significantly between the two groups. During the follow-up period (mean duration 15.5 months), however, six deaths occurred in the control group and only one in the perfusion group. At necropsy four of the controls had multiple liver metastases. Two of the surviving controls developed evidence of liver metastases, and two had a local recurrence. No patient in the perfusion group developed evidence of hepatic metastases. These initial results suggest that adjuvant portal venous perfusion with fluorouracil may reduce the incidence of liver metastases in colorectal cancer.


Computer-aided prediction of gangrenous and perforating appendicitis.

The clinical details of 100 patients with proved acute appendicitis were compared with those of 100 patients with perforating or gangrenous appendicitis. Twenty features were found to be significantly different between the two groups. This information was incorporated into a computer data base and used in the differential diagnosis of abdominal pain. A program written to predict the probability that gangrene or perforation was present in patients with appendicitis gave a diagnostic accuracy over 91%. A clinical scoring index, which accurately predicted the state of the appendix in 88% of patients, was constructed from the significant differences between the two groups. When clinical scoring or computer analysis predicts a high probability of perforation or gangrene in patients with appendicitis, surgery should be performed without delay.


Cervical ripening with intravaginal prostaglandin E2 gel.

We describe a technique of administering prostaglandin E2 (PGE2) in a viscous cellulose gel into the vagina to ripen the unfavourable cervix in patients requiring induction of labour. A total of 168 primigravidae were studied, of whom 102 received 2 mg PGE2 in 2% gel and 66 received 5 mg PGE2 in 4% gel. In the latter group, the state of the cervix was significantly improved in 58 patients (87.9%), while 32 (48.5%) had started labour before planned induction. There were no maternal or fetal side effects or complications.


Antithrombotic potential of dihomo-gamma-linolenic acid in man.

The effects of orally ingested dihomo-gamma-linolenic acid (DHLA), the natural biosynthetic precursor of prostaglandin E1 (PGE1), were assessed in human volunteers. Single doses of DHLA (0.1--2g) increased the proportion of DHLA relative to arachidonic acid in plasma and platelets and also increased the ex-vivo capacity of platelets to produce PGE1 and PGE2. More pronounced effects were observed during sustained treatment (five days to four weeks) when DHLA also accumulated in red cell membranes. These biochemical changes were accompanied by potentially antithrombotic changes in haemostatic function. The most common effect, which was consistently detected after 0.1-g single doses of DHLA or its methyl ester, was a decrease in plasma heparin-neutralising activity. Inhibition of platelet aggregation induced by adenosine diphosphate was also detected, though this was generally less pronounced. Sustained treatment in one subject also produced definite inhibition of ristocetin-induced platelet aggregation. There was only one possible adverse effect--a transient cough in a subject with a history of asthma. DHLA therefore seems to have considerable potential as an agent for preventing and treating human thromboembolic disease.


The case for recording events in clinical trials.

The value of clinical trials in detecting unwanted effects of new medicines would be enhanced if doctors recorded all adverse events experienced by patients and not just those regarded as adverse reactions to drugs. All events should be reported to the centre co-ordinating the trial and analysed in treated patients and controls. This method might have revealed the ocular toxicity of practolol before the drug was marketed in 1970.


Leucocytosis is not a manifestation of rejection.

The leucocyte response to allograft rejection was retrospectively analysed in 80 rejection episodes that occurred in 50 patients. There was no significant change in leucocyte count in 32 rejection episodes. In 27 there was a fall in leucocyte count of more than 20% and in only 21 was there a rise in count of more than 20%. Thus leucocytosis seems not to be a manifestation of rejection; indeed, it is the least common response, a fall in the count being commoner. The results also suggest that the prognosis for the graft is poorer when the leucocyte count falls significantly.


The pattern of immunological responses at various stages of syphilis.

Each of 212 sera, taken from 129 patients with clinically established syphilis, was subjected to seven immunological tests. The tests were designed to detect both anti-lipoidal and anti-treponemal antibodies and to titrate antibody of both IgG and IgM molecular species. It was found that patients of similar clinical history were usually recognisable by the similarity of results obtained in the seven tests, and a progression of these patterns of results was also found in samples of serum taken from individual patients during the course of their disease. It is suggested that this more comprehensive type of serological examination of patients can provide valuable information to the clinician.


Quantitative evaluation of the FTA-ABS-IgM and VDRL test in treated and untreated syphilis.

Observations made on fluorescent treponemal antibody absorption (FTA-ABS) immunoglobulin M (IgM) titres in patients with untreated early syphilis showed non-reactive or weakly reactive results in patients with primary (one of five cases) and secondary (two of 16 cases) lesions. In patients with primary (19.5%) and secondary (15%) syphilis sera remained reactive with increased titres for more than one year after treatment. The respective figures in the results of the Venereal Disease Research Laboratory (VDRL) test were zero in primary and 20% in secondary syphilis. The non-reactive FTA-ABS IgM results may possibly be explained by competitive inhibition of IgM by immunoglobulin G (IgG). The persistence of reactivity in a comparable percentage has been observed by other investigators (Grin et al., 1974; Wilkinson and Rodin, 1976). The current results therefore suggest that FTA-ABS IgM titres are less reliable for assessing the effect of treatment than the course of the VDRL titres. The phenomenon of a decrease in FTA-ABS IgM titres soon after treatment with a later rise before final non-reactivity is a matter for further investigation.


How suitable are available pharmaceuticals for the treatment of sexually transmitted diseases? 1: Conditions presenting as genital discharges.

The relative prevalence of sexually transmitted diseases and the agents available for the treatment of these diseases commonly presenting as genital discharges-namely, gonorrhoea, candidosis, trichomoniasis, and non-specific genital infection-are reviewed. The many agents that are active against gonorrhoea are listed, but none is ideal. Penicillin, in spite of its allergic side effects, has remained the drug of choice for 25 years because it is cheap, easily obtained, lacks toxicity even in pregnancy, and is effective. Its use is now threatened by the emergence of some strains that are able to produce penicillinase. At present the policy is to obtain the best results from penicillin while these are acceptable, but the clinician in some countries is badly served by the availability of procaine penicillin in aqueous suspension. There is a need for an effective penicillin or cephalosporin that is penicillinase resistant and cheap. Cefuroxime offers considerable hope but it is likely to be expensive in the immediate future.There are many preparations for the local treatment of candidosis. The confidence expressed by the manufacturers in recommending a three-day treatment is, it is hoped, based on a superior product. Nevertheless there is a need for a safe systemically absorbed fungicide which could be used orally, or some substance that could render the vagina an inhospitable environment for the organism.In the treatment of trichomoniasis the pharmaceutical industry in providing substances more than 90% effective in a single dose has done all that can be expected. Any further advances lie in the field of human behaviour rather than pharmaceutical research.In the treatment of non-specific genital infection the needs are more of research than of therapy. More knowledge is required of the cause of the condition and the relative role of contending pathogens, and of the results of treatment of patients and contacts in which Chlamydia or other suspect pathogens have been isolated.


Structural alterations of peripheral nerve induced by the calcium ionophore A23187.

Desheathed segments of rat peripheral nerve were incubated at 37 degrees C in oxygenated Ringer's solution with and without the addition of calcium ionophore, A23187, 10 microgram/ml. Nerve fibers incubated in the presence of both ionophore and calcium revealed extensive granular disintegration of their axonal microtubules and neurofilaments after 30 and 60 min incubation intervals. These changes were not seen following control incubations in Ringer's solution without ionophore or in calcium-free Ringer's solution containing ionophore and EGTA, 1 mmole/1. Ionophore-induced alterations were also noted in Schwann cell cytoplasm. The granular degradative alteration of axoplasm caused by exposure of nerve fibers to ionophore and calcium were believed to be due to an ionophore-mediated influx of calcium into the axoplasm with resultant elevation of intra-axoplasmic calcium concentration. These axoplasmic changes were indistinguishable from the axoplasmic alteration occurring in the distal portions of transpected neurites during Wallerian degeneration. The findings support the view that abnormal calcium influxes are determinants in the degeneration of peripheral nerve.


Recombination values and their errors.

Two four-point testcrosses comprising 87,000 tomato plants were grown and the data collected from 28 subgroups. Each subgroup consisted of 2,000 or 5,000 plants and should give a valid estimate of the three recombination values. The 28 values for each interval give more outlyers (23% are outside the 95% limits set by the standard deviation calculated by the binomial formula square root of p q/n) than would be expected by chance. If each subgroup was regarded as the control and the other groups tested against this, then 42% of the time the two subgroups would be significantly different. It is suggested that there are many cases in the literature where this comparison has been made and the significant difference wrongly ascribed to treatment. While the causes of these changes in recombination value are unknown and therefore uncontrollable, they must be anticipated in all such studies. Control and treatment must be replicated enough that chance extreme values will not be attributed to treatment.


Malignant tumours of bone: clinical aspects and natural course.

An accurate pathological diagnosis must be made prior to treatment of a primary malignant bone tumour. Consideration must be given to the clinical and radiologic aspects as well as the histology. Both benign and malignant tumours occur more frequently in certain decades. A search should be made for precursor lesions such as Paget's disease. The presenting manifestations of pain, a mass and dysfunction are not specific for tumours. Laboratory tests may be helpful, especially in distinguishing tumours from infections and metabolic diseases. Metastasis is usually via the blood stream to the lungs and bones. The low survival rate following amputation for osteosarcoma and radiation therapy for Ewing's sarcoma has been improved by chemotherapy. The lower-grade tumours such as aggressive giant cell tumour and low-grade chondrosarcoma can often by treated successfully by resection and insertion of an autograft, an allograft or a metallic implant.


Place of resection in the management of primary bone tumours.

A primary malignant sarcoma of bone in an extremity must be removed so that it will not recur locally. Amputation will accomplish this in most cases but a prosthesis is required. In carefully selected cases of malignant giant cell tumour, low-grade chondrosarcoma, low-grade fibrosarcoma, parosteal osteogenic sarcoma and adam-antinoma, resection with insertion of an autograft, allograft or metallic implant has been successful. More recently implants have been used following resection of the more malignant tumours such as osteosarcoma, high-grade fibrosarcoma and high-grade chondrosarcoma, but further time is required to determine the problems secondary to chemotherapy, other complications, the length of time for rehabilitation, and the quality of life after this procedure as compared with the more conventional amputation with early prosthetic titting.


A short encounter with Anna Freud at Berggasse 19.

This article discusses a short encounter with Dr. Anna Freud in her former consulting office in Vienna at 19 Berggasse in May 1977. Dr. Freud had gone to Vienna for the laying of a marble plaque at the site of the former BelleVue Hotel where Sigmund Freud had first started his work on the 'interpretation of dreams'. In 1900 Dr. Sigmund Freud had written to Wilhelm Fliess "Do you suppose that some day a marble tablet will be placed on the house, inscribed with the words: 'in this house on July 24, 1895, The Secret of Dreams was revealed to Dr. Sigmund Freud' At this moment I see little prospect of it". This request was realized on 6 May 1977 and the author who was present at the ceremonies, describes some of the events.


The impact of government insurance on a psychiatric clinic.

This paper considers the impact of a state medical insurance system on the structure of psychiatric services. The tendency of the upper socioeconomic classes to use private practitioners, and the lower classes to use public clinics, is examined before and after the imposition of the medical insurance system in Quebec in 1970. Data from one public clinic reveal a significant rise in the socioeconomic status of patients after Medicare. Alternative interpretations for the change in the clinic population are explored.


Adriamycin plus alkylating agents in the treatment of metastatic breast cancer.

A randomized trial of Adriamycin (A) in combination with melphalan (M), (MA therapy), and in combination with M plus cyclophosphamide (C) (MAC therapy), was initiated in 40 evaluable patients with metastatic breast cancer. Twenty-two patients demonstrated an objective response to therapy: 9/20 to the MA regimen, and 13/20 to the MAC regimen. For the 22 responders, median duration of response is not yet achieved for either complete or partial responders, at 10 and 9 months, respectively. The addition of the two alkylating agents to Adriamycin was superior to the single alkylating agent addition, both in total response rate and in completeness of response. Maintenance therapy, after achieving the maximum cumulative dose of Adriamycin, was provided by cyclophosphamide plus methotrexate and 5-fluorouracil (CMF). In 19 patients completing induction and entering maintenance therapy, only one relapse has developed with maximun follow-up at 15 months.


High dose methotrexate with citrovorum factor in adult resistant lymphoma.

Seven adult patients with advanced lymphoma, resistant to vincristine, prednisone, alkylating agents and Adriamycin were treated with "high dose" methotrexate and citrovorum factor rescue. Therapy consisted of 4 to 6-hour infusions of methotrexate (5--100 mg/kg) every 1 to 2 weeks with citrovorum rescue initiates 2 to 12 hours after termination of the infusion. Objective responses were obtained in three patients but these were short lived. Mucosal and hematologic toxicity occurred when repeat courses of therapy were administered. The results suggest that high dose methotrexate may be effective therapy in lymphoma, particularlly if citrovorum factor rescue is used early and in adequate dosage.


Ultrastructure of aneurysmal bone cyst.

The ultrastructure of 5 cases of primary aneurysmal bone cysts is described. The most frequent cells found are fibroblasts containing varying amounts of glycogen. Primitive mesenchymal cells in different stages of differentiation are seen. The foci of osteoid and bone originate through metaplastic changes of the spindle cell stroma. We feel that the fibroblastic proliferation and bone formation are manifestations of a reactive process. The giant cells are similar to those of other giant cell lesions of bone. A case of cystic chondroblastoma with secondary aneurysmal bone cyst features was studied. It shows, in addition to chondroblastoma cells, elongated cells similar to the reactive fibroblasts of primary aneurysmal bone cyst. We feel that aneurysmal bone cyst is a benign non-neoplastic condition that can develop in bone as a primary bone lesion; it may also be associated with a pre-neoplastic condition that can develop in bone as a primary bone lesion; it may also be associated with a pre-existing bone condition, and occasionally develops following trauma with subperiosteal hematoma.


Granulocytic sarcoma of the cervix as a primary manifestation: case without overt leukemic features for 26 months.

A case of granulocytic sarcoma involving the uterine cervix as primary manifestation without evidence of leukemia is presented. It was followed by neurological symptoms 19 months later and a right breast mass 26 months after the initial cervical lesion, but still with no evidence of leukemia. Two years and four months after onset, soft tissue and skin nodules developed and rare blastic cells appeared on peripheral blood smear. The patient terminally developed acute granulocytic leukemia with a rapidly downhill course. The differential diagnosis of granulocytic sarcoma and histiocytic lymphoma is discussed. The literature is reviewed with emphasis on the clinical and pathological problems that arise when the tumor presents in an unusual location without peripheral blood manifestation of leukemia.


Malignancy arising in extragonadal endometriosis: a case report and summary of the world literature.

A case of clear cell carcinoma arising in endometriosis of the retroperitoneum is presented. It occurred 5 years after supracervical hysterectomy and bilateral salpingo-oophorectomy and following 4 years of estrogen therapy. The literature concerning malignancy developing in extragonadal endometriosis has been reviewed and is summarized as follows: 1) 45 cases have been compiled, of which 32 were carcinomas and 13 sarcomas; 2) adenocarcinoma was the most common histologic type, although virtually every tumor of müllerian derivation has been described; 3) the typical patient was nulliparous and perimenopausal; 4) the rectovaginal septum was the most common site, and in general the frequency of malignancy in a given site parallels the frequency of endometriosis in that location; 5) simultaneous tumors of the uterus or ovary were present in seven cases (15%); 6) prognosis appeared affected by site and histologic type; 7) a history of prior pelvic irradiation to effect castration was present in three (9%) of the patients with adenocarcinoma; and 8) four (12%) of the patients with adenocarcinoma were subjected to exogenous estrogens or estrogen-secreting ovarian tumors.


Breast metastasis: an unusual manifestation of a malignant carcinoid tumor.

A metastasis from a bronchial carcinoid tumor presented as an isolated breast mass in a 58-year-old female. A review of the English literature revealed four cases of metastatic carcinoid to the breast that presented as an isolated breast mass. In each case, radical mastectomy was performed after the lesion had been interpreted clinically and pathologically as a primary carcinoma. When the primary tumor was excised, all cases had either regional lymph node or liver involvement. A mass was the usual presenting sign of the metastatic deposit. No metastasis was reported to be greater than 2 cm in diameter. No axillary lymph nodes were reported to contain tumor. Frozen section preparations may not be adequate to differentiate a primary carcinoma of the breast from a metastatic carcinoid tumor, thereby necessitating permanent sections, special stains, review of previously resected neoplasms, or electron microscopy. The first mammogram of a metastatic carcinoid to the breast is reported with this case.


Anti-squamous tumor antibodies in patients with squamous cell carcinoma.

Patients with advanced squamous cell carcinomas were shown to have serum antibodies directed towards cultured squamous tumor cells as shown by quantitative membrane immunofluorescence. The sera of these same patients did not react with a variety of other cultured tumor cells. Serum obtained from normals or from patients with other forms of cancer (transitional cell carcinoma, adenocarcinoma, and melanoma) did not give positive reactions. When the sera of squamous carcinoma patients were chromatographed on Sephadex G-150, tumor-reactive antibodies were recovered solely in the 19 S fraction, suggesting immunoglobulin M as the immunoglobulin isotype involved. Identification of the squamous tumor cell-reactive immunoglobulin as ijmunoglobulin M was confirmed by quantitative immunofluorescence with the use of class monospecific antisera to human immunoglobulins.


Hydroxylated metabolies of R,S-1-(tetrahydro-2-furanyl)-5-fluorouracil (Ftorafur) in rats and rabbits.

Two hydroxylated metabolies (M1 and M2) have been isolated from rabbit urine after administration of Ftorafur (FT). The structures of 3'-OH-FT and 4'-OH-FT were assigned to M1 and M2, respectively. A reverse-phase high performance liquid chromatography assay was developed for jeasuring FT, M1, M2, and 5-fluorouracil (FU) plasma levels. M1, M2, and FU were present in rabbit and rat plasma in greatly varying concentrations after FT administration. Pharmacokinetic studies suggest that FU formation proceeds via metabolic intermediate(s) and that the extent of FT activation is variable. A horse liver thymidine phosphorylase ,reparation capable of catalyzing the conversion of beta-ribo-2'-deoxy-5-fluorouracil to FU was inactive against FT and M1. However, 20% of M2 was converted to FU by this enzume, which suggests that the urinary metabolite M2 consisted of a mixture of enantiomers with 20% present in the natural beta-D configuration. The stereochemistry of M1 remains unknown. Hydroxylation of FT to beta-D-4'-OH-FT and subsequent cleavage to FU by thymidine phosphorylase represents one possible activation mechanism of FT to FU. ,owever, lack of correlation between plasma levels of M2 and FU indicates that this mode of metabolic activation may account for only part of the overall activation of FT in vivo.


Left axis deviation as a single screening criterion in acquired nonvalvulvar heart disease. Association with abnormal systolic time intervals in hypertensive subjects.

The value of left axis deviation (LAD) as a single discriminator of clinical cardiac abnormality and its association with reduced left ventricular function was investigated in 100 consecutive ambulatory subjects with LAD, and 100 age and sex-matched subjects without LAD from the patient population of a voluntary screening clinic. Analysis of clinical data and measurement of QRS frontal plane axis as well as systolic time intervals (STI) were each done separately by different investigators in a blind manner. The only large groups in the study population were those with coronary heart disease and those with hypertension. The high prevalence of definite and probable coronary artery disease among subjects with LAD (32/100) contrasted with its paucity in the control group (8/100). Hypertensive and borderline hypertensive subjects occurred in sufficient numbers.


Clinical implications of atrioventricular and intraventricular conduction abnormalities II. Acute myocardial infarction.

The diagnostic criteria and the clinical implications of atrioventricular and intraventricular conduction defects have been reviewed. Information derived from His bundle electrocardiographic studies has been incorporated in the discussion and the importance of the site of block has been stressed. Defects in the trifascicular intraventricular conduction system and their relation to prognosis and to development of complete heart block are outlined. Data on the prognosis of conduction abnormalities during acute myocardial infarction are reviewed in depth and current indications for temporary and permanent pacemaker implantation are presented.


Immunofluorescent localization of ovine placental lactogen.

The localization of ovine placental lactogen (OPL) was studied using the immunofluorescence method. The placentome sections were treated by an indirect technique with anti-OPL antibodies obtained from rabbits injected with purified hormone. OPL was located in large cells of the monostratified epithelium of chorionic villi. These cells are mono- or binucleated and PAS-positive. The immunological reaction was inhibited by the specific antigen (OPL, 400 microgram/ml undiluted anti-OPL antiserum) but not by ovine prolactin, bovine growth hormone, human placental lactogen nor by any other polypeptidic hormone tested. Reciprocally, the localization of OPL-secreting cells was unsuccessful with antibodies raised against these control hormones.


Ultrastructural identification of a new cell type--the N-cell as the source of neurotensin in the gut mucosa.

The neurotensin-cell is identified immunohistochemically and ultrastructurally by differential counting of endocrine cells in the gut of a primate (Tupaia belangeri). Utilizing light microscopy, the EC-cells are identified by the Masson-Fontana silver stain; with the same method the neurotensin cells are not stained. The other endocrine cells have been quantified in the small intestine using the peroxidase-antiperoxidase stain with antisera against glucagon, somatostatin, cholecystokinin, gastrin, secretin, pancreatic polypeptide, gastric inhibitory peptide and neurotensin. In the ileal mucosa of Tupaia, the most frequent endocrine cell is the EC-cell followed by the glucagonoid cell, (L-cell). The immunoreactive neurotensin cell represents the third most frequent endocrine cell in this region. On the ultrastructural level, this third most frequent endocrine cell is a heretofore undescribed cell, the N-cell, containing electron dense secretory granules measuring 335 +/- 87 nm in diameter.


alpha-1-Antitrypsin immunoreactivity in islet cells of adult human pancreas.

alpha-1-antitrypsin immunoreactivity was demonstrated by immunofluorescence technique in the peripheral islet cells of all ten normal adult human pancreata examined; normal adult human liver was negative. The specificity of the reactions was confirmed by applying various control tests including absorption of the specific antisera with purified alpha-1-antitrypsin, inhibition and blocking tests and by ensuring the monospecificity of the antisera used. The findings suggest that the pancreatic islet may be an additional source of alpha-1-antitrypsin.


[Indirect immunofluorescence study of 200 cases of tryponosomiasis due to Trypanosoma gambiense].

The sera and CSF collected on 200 patients suffering from sleeping sickness were collected before treatment and tested with fluorescent antibody test. The proportion of strongly positive sera is very important in the first period and decreases progressively with the alteration of CSF. This shows the reliability of the FAT technique as a screening method because it is in the first period that it is difficult to diagnose the disease. 14% of CSF collected during the 1st period are positive with FAT: this fluorescence certainly reflects the presence of the parasite and confirms Burke et al. observations. The notion of periodicity can be questioned as well as the treatment protocol whick is traditionally based on the CSF cytochemistry.


Variations in structure and function during the life cycle of malarial parasites.

The fine structure of malarial parasites is reviewed and the function of the intracellular organelles is discussed. When the erythrocytic, exoerythrocytic, and mosquito stages of plasmodia are compared, substantial differences are seen. The major differences involve the amount of surface coat of the motile forms, the structure and function of the mitochondria, and the ingestion and digestion of nutrients. Significant structural differences are also observed between comparable stages of mammalian and avian parasites. These differences indicate that malarial parasites adapt themselves to the different environments in which the parasite resides.When host cell changes induced by malarial parasite infection are reviewed, alterations characteristic of the infecting plasmodia are observed in erythrocytes. Erythrocyte changes include caveola-vesicle complexes, excrescences, and clefts. The caveola-vesicle complexes possess malarial antigens and exhibit pinocytotic activities. The excrescences form focal junctions with adjacent cells and may be responsible for infected erythrocyte sequestration in organs. The significance of these host cell changes specific to certain species of malarial parasite is still unknown.


Invasion and growth of Plasmodium falciparum in different types of human erythrocyte.

The susceptibility of human red blood cells to invasion by Plasmodium falciparum was investigated in microtissue cultures with different populations of erythrocytes containing fetal haemoglobin (HbF). Preferential invasion of HbF-containing erythrocytes was observed with umbilical cord blood. The parasites showed no preference for HbF cells in blood from a subject with hereditary persistence of fetal haemoglobin (HPFH). By contrast, a significant preference for HbA-containing erythrocytes was found with blood from young infants. Further experiments demonstrated that falciparum parasites preferentially invade "young" erythrocytes. This could explain the distribution of parasites found in blood containing HbF, because HbF-containing erythrocytes are "younger" on average in cord blood, "older" in the blood of infants, and of the same average age as HbA-containing cells in HPFH. We concluded that the susceptibility of human erythrocytes to invasion by P. falciparum is not correlated with the presence of HbF, but that aging of red cells in vivo decreases their susceptibility to invasion. Semi-quantitative measurements were made of parasite growth in cells containing HbA or HbF. The growth of individual parasites in cells containing HbF was significantly retarded. This might confer a selective advantage on individuals with thalassaemia and sickle cell trait, in which HbF levels are raised in early life.


A histidine-rich protein from Plasmodium falciparum and its interaction with membranes.

In previous studies, an unusual protein with 70% of histidine was isolated from Plasmodium lophurae. It was shown to have a possible function in the penetration of merozoites into erythrocytes. The results of the present study indicate the presence of a similar histidine-rich protein in Plasmodium falciparum. Like that of P. lophurae, the histidine-rich protein of P. falciparum is acid-soluble, but it has a slightly higher molecular weight.


Transport of amino acids and nucleic acid precursors in malarial parasites.

In vitro studies have shown that exogenously supplied amino acids are transferred into the malaria-infected cell, where they are incorporated into proteins. Most amino acids appear to enter the cell by facilitated or simple diffusion; however, the high distribution ratios seen in Plasmodium knowlesi-infected cells are difficult to explain on this basis. The changes (leakiness) observed in amino acid transport in P. lophurae infected cells are probably the result of ATP depletion in the host cell as well as the elaboration of plasmodial substances. Depletion of isoleucine, methionine, and cysteine from the medium strikingly depresses the in vitro growth of P. knowlesi. The degree of amino acid incorporation into the malaria-infected cell is not correlated with the amount of a particular amino acid in the host cell haemoglobin, the decline of that amino acid in the plasma of infected animals, or the ratio of free amino acids of the erythrocyte to those of the plasma. In erythrocyte-"free" P. lophurae, carrier-mediated transport is apparently limited to a small number of amino acids; all others seem to enter by simple diffusion.Malaria-infected erythrocytes transport exogenously supplied purines at substantially higher rates than uninfected red cells. The preferred purines are adenosine, hypoxanthine, and inosine. The only pyrimidine incorporated is orotic acid. Thymidine, cytidine, and uridine do not readily enter the red cell, and incorporation does not take place because the parasites lack the appropriate enzyme for conversion to nucleotides. Erythrocyte-"free" P. berghei and P. lophurae take up purines and orotic acid. It has been suggested that in vivo the preferred purines are hypoxanthine and inosine, and that the transport locus for erythrocytes is specific for 6-oxopurines. Similar results of purine incorporation are reported for the insect stages of P. cynomolgi and P. berghei, although transport studies have not been carried out.


Carbohydrate metabolism of malarial parasites.

The evidence for the pathways involved in the metabolism of carbohydrates by malarial parasites is critically reviewed. In all species studied, glucose is catabolized mainly by glycolysis with little participation of the pentose-phosphate pathway. It has not been proved conclusively that there is a functioning citric acid cycle in the intraerythrocytic stages of avian plasmodia, nor is it certain that these stages of any malarial parasites use oxygen.


Isolation and analysis of nucleotides from erythrocyte-free malarial parasites (Plasmodium berghei) and potential relevance to malaria chemotherapy.

Studies using erythrocyte-free preparations of P. berghei were conducted with a view to improving knowledge of parasite metabolism, particularly nucleotide metabolism. The free parasites employed in these studies were prepared by saponin lysis of parasitized mouse erythrocytes in isotonic glucose solutions. A comparative study of post-lytic metabolic activity of free parasites prepared by saponin, ammonium chloride, or osmotic lysis indicated a significantly greater retention of metabolic activity in the saponin-lysis preparations. Separations of nucleoside mono-, di-, and triphosphates extracted from free parasites were performed by means of high pressure liquid chromatography (HPLC), and ATP was additionally measured by luciferin-luciferase assay. Studies designed to differentiate among uptake, phosphorylation, and subsequent incorporation of (3)H-adenosine into nucleic acids of the free parasite strongly suggested that adenosine is metabolized either outside or on the parasite membrane, being first deaminated to inosine and then deribosylated to hypoxanthine. Observations from HPLC and radioisotope precursor studies support a hypothesis in which hypoxanthine may be proposed as being a pivotal substrate for purine salvage by malarial parasites. Some of the key steps in purine salvage and pyrimidine biosynthesis were investigated, using radiolabel uptake studies and HPLC analysis of nucleotides of the free malarial parasite. These studies suggest that hypoxanthine uptake may constitute an important new basis for chemotherapeutic attack on the malarial parasite.


Amino acid metabolism and protein synthesis in malarial parasites.

Malaria-infected red cells and free parasites have limited capabilities for the biosynthesis of amino acids. Therefore, the principal amino acid sources for parasite protein synthesis are the plasma free amino acids and host cell haemoglobin. Infected cells and plasmodia incorporate exogenously supplied amino acids into protein. However, the hypothesis that amino acid utilization (from an external source) is related to availability of that amino acid in haemoglobin is without universal support: it is true for isoleucine and for Plasmodium knowlesi and P. falciparum, but not for methionine, cysteine, and other amino acids, and it does not apply to P. lophurae. More by default than by direct evidence, haemoglobin is believed to be the main amino acid reservoir available to the intraerythrocytic plasmodium. Haemoglobin, ingested via the cytostome, is held in food vacuoles where auto-oxidation takes place. As a consequence, haem is released and accumulates in the vacuole as particulate haemozoin (= malaria pigment). Current evidence favours the view that haemozoin is mainly haematin. Acid and alkaline proteases (identified in crude extracts from mammalian and avian malarias) are presumably secreted directly into the food vacuole. They then digest the denatured globin and the resulting amino acids are incorporated into parasite protein. Cell-free protein synthesizing systems have been developed using P. knowlesi and P. lophurae ribosomes. In the main these systems are typically eukaryotic.Studies of amino acid metabolism are exceedingly limited. Arginine, lysine, methionine, and proline are incorporated into protein, whereas glutamic acid is metabolized via an NADP-specific glutamic dehydrogenase. Glutamate oxidation generates NADPH and auxiliary energy (in the form of alpha-ketoglutarate). The role of red cell glutathione in the economy of the parasite remains obscure. Important goals for future research should be: quantitative assessment of the relative importance of amino acid sources for parasite protein synthesis; purification and characterization of plasmodial proteinases; and in vitro translation of parasite messenger RNA.


Folate metabolism in malaria.

It is known that malaria parasites are inhibited by sulfonamides and antifolate compounds, require 4-aminobenzoic acid for growth, and respond only partly to intact folic and folinic acids. Biochemical data obtained during the last decade on the synthesis of nucleic acid precursors and on folate enzymes in malaria support the hypothesis that malaria parasites are similar to microorganisms that synthesize folate cofactors de novo. Sulfa drugs inhibit plasmodial dihydropteroate synthase (EC 2.5.1.15). Pyrimethamine and many other antifolate compounds bind to tetrahydrofolate dehydrogenase (EC 1.5.1.3) of the parasite more tightly than to the host enzyme. However, the metabolic consequences of the depletion of folate cofactors as a result of drug inhibition are not yet known. Other areas to be studied are the origin of the pteridine moiety of folates, the addition of glutamate(s) in folate cofactor biosynthesis, the means by which intact, exogenous folates affect malarial growth, and demonstration of the enzymes and reactions involving N(5)-methyl tetrahydrofolate.


Ultrastructure and viability of cryopreserved Plasmodium falciparum.

Cryopreserved chimpanzee erythrocytes infected with Plasmodium falciparum were examined by electron microscopy directly and after a period of culture. Light microscopic observations on the viability of cryopreserved parasites in culture were also made. Parasitaemia data from a chimpanzee infected with parasites cryostored for more than 2(1/2) years are presented. Varying degrees of damage were apparent as the parasites were examined in vitro, for viability, and by electron microscopy. Schizonts appear not to survive the process, whereas the ability of "ring" trophozoite forms to develop into large trophozoites in vitro varies from 20% to 100% in different preparations. Cryopreserved material examined by electron microscope showed degenerative changes in most of the parasites, but after 72 h of cultivation most of the parasites appeared normal. These findings suggest that some organisms may sustain reversible damage during cryostorage.


The isolation and fractionation of malaria-infected cells.

This paper is a critical review of procedures for the isolation of malarial parasites from host cells and their fractionation. The procedures are grouped according to the stage of parasite being isolated, and the procedures for isolation of the erythrocytic stages are further grouped by techniques used. Some types of procedure are described for isolation of all stages of the parasite, both those in the invertebrate and vertebrate hosts. The uses and limitations of the various procedures are described. It is concluded that all the procedures are useful for some purposes, but that from a morphological standpoint only natural release in culture and continuous flow oscillation provide large yields of intact erythrocytic parasites free of host cell membranes.


Cultivation of erythrocytic stages.

Two methods are described for the continuous cultivation of Plasmodium falciparum. One method provides for a continuous slow flow of medium over a settled layer of blood cells and does not require daily attention. With the other method, carried out in Petri dishes, the medium has to be changed manually every day. The problems and possibilities of continuous cultivation are discussed.