DNA repair synthesis in human skin exposed to ultraviolet radiation used in PUVA (psoralen and UV-A) therapy for psoriasis. The ultraviolet radiation used for PUVA therapy stimulated DNA repair activity in normal human skin and in the uninvolved skin from psoriatic patients. The activity detected by autoradiography increased linearly with exposure time. No stimulation was observed when the UV-B component was removed from the incident radiation by filtration through glass. Therefore UV-B damage to DNA was found responsible for the activity detected following exposure to the unfiltered PUVA light source.


Studies on the plasma membrane of normal and psoriatic keratinocytes. I. Preparation of material and morphological characterization. A method is described for the preparation of isolated keratinocytes suitable for subsequent biochemical studies. Scanning electron microscopy showed that the maturation process is accompanied by an increase in cell size and a shortening and eventual loss of microvilli. Psoriatic keratinocytes are distinguishable by exhibiting longer microvilli at all levels of maturation.


Prolonged BCG treatment of melanoma: does it suppress the immune capacity? The immunological status of seven patients with disseminated melanoma during BCG scarification was followed. As parameters, the total peripheral blood leukocyte and lymphocyte counts, serum immunoglobulin levels, natural ABO blood group antibodies, lymphocyte responses in vitro to PHA and PPD, and skin reactivity against PPD and candidin were followed during a period of 2--36  months. The EAC-rosette-forming cells increased and the E-rosette-forming cells decreased during prolonged BCG therapy. The skin reactions and lymphocyte responses showed in most patients conversion from negative to positive or augmentation at the start of the therapy. Later on, however, the values in most patients dropped before disseminated disease became clinically apparent. In the only surviving patient the values first increased, remained high, and after 100 weeks treatment decreased. After 140 weeks' treatment immunological parameters are similar to pre-treatment levels. The possibility that prolonged intensive BCG treatment might eventually suppress the immune system, and thus result in an enhanced risk of dissemination of the disease, is discussed.


Atopic disease and dermatitis herpetiformis. Patients with dermatitis herpetiformis were found to have an increased incidence of atopic disorders compared to an age and sex matched control group. The increase in incidence was statistically significant for atopic eczema and any atopic disorder. Serum immunoglobulins (including IgE) were estimated in forty-five dermatitis herpetiformis patients and no significant abnormalities were found.


Skin conductance conditioning with dyshidrotic eczema patients. Thirty-three patients with dyshidrotic eczema were trained either to decrease or to increase the electrical conductivity of the skin. Skin conductance has been found to be related to epidermal water content as well as emotional variables, both of which have suggested links to eczema. Subjects trained to decrease skin conductance showed clinical improvement more often than the controls who were trained in the opposite direction. They also showed a significant decrease in measured conductance and anxiety. The controls showed increased anxiety and no significant changes in skin conductance level.


The normal trichogram of pubic hair.

The normal trichogram of pubic hair. The parameters of the trichogram of the pubic hair were studied with a previously described technique. Measurements were made on males and on non-pregnant, pregnant and post-partum females. In males and non-pregnant females denisty and rate of growth steadily decrease with age. There was a higher percentage of telogens in women. Hair thickness was not modified. The most important findings are related to pregnancy and post-partum which did not induce any change in the parameters of the trichogram of the public area. These findings indicate a behaviour of the pubic hair different from the scalp and axillary hair.


Quantitative microbiology of human vulva. The microbial flora of the vulva is described and compared with the flora of the forearm by utilizing the detergent scrub method. Microbial counts were higher on the vulva (2.8 x 10(6)/cm2) than on the forearm (6.4 x 10(2)/cm2). Lipophilic diphtheroids, coagulase negative staphylococci, micrococci, non-lipophilic diphtheroids and lactobacilli formed the dominant flora of the vulva. Streptococci, Gram negative rods and yeasts were also noted. The highest incidence of S. aureus was noted on the vulva (67%) followed by perianal (30%), nose (30%), and the forearm (11%).


Skin diseases in Zambia.

Skin diseases in Zambia. This is the first report on the incidence of skin diseases in Zambians. A diagnostic analysis of 12,610 patients seen over the past year in the Dermatology Clinic at the University Teaching Hospital in Lusaka, Zambia, is presented. The common diseases as well as the peculiarities are discussed. The need to develop research centres in various regions of Africa is emphasized in order to provide better insight into the special dermatological problems seen in the black Africans.


Male pattern alopecia and coronary artery disease in men. The prevalence of male pattern alopecia, coronary artery disease, hypertension and smoking habits were studied in 478 male Caucasian hospital in-patients, over the age of 20 years. No association was shown between coronary artery disease and either male pattern alopecia, premature male pattern alopecia or male pattern alopecia with a positive family history.


Aggressive basal cell carcinoma in Nigerians. It is important to emphasize that basal cell carcinoma occurs in black Africans, a fact denied in some reports. The present study shows that the disease appears to behave more aggressively in the African, particularly in albinos, than in Caucasians. In albinos preventive measures should be employed regularly.


A modified non-radioisotope method for measurement of platelet production time. Platelet production time (PPT), based on the measurement of malondialdehyde (MDA) production prior to and after the intake of acetylsalicylic acid (ASA), was determined in 20 healthy subjects. High MDA levels were produced by stimulating platelet lipid peroxidation with arachidonic acid, resulting in a reliable, sensitive and accurate technique. PPT correlated well with platelet survival time measured by 51Cr autologous labelled platelets when both methods were used simultaneously in the same patients. This modified non-radioisotope method might serve as a useful aid in the diagnosis of platelet disorders, thromboembolic diseases associated with increased platelet consumption and for the evaluation of drugs affecting platelet function.


Haemophilia 'A' in a 46,X,i(Xq) female.

Haemophilia 'A' in a 46,X,i(Xq) female. A phenotypically normal female, with negative family history for bleeding disorders, was found to be affected by severe haemophilia A. All laboratory tests performed confirmed the diagnosis. Chromosome analysis showed the presence of an X isochromosome of the long arm in every cell. It is hypothesized that the propositus inherited the affected X from her mother, a probable carrier, and the isochromosome, of paternal origin, was not able to mask the abnormal gene.


Blocking and binding type antibodies against all major vitamin B12-binders in a pernicious anaemia serum. The simultaneous occurrence of blocking and binding antibodies to intrinsic factor (IF), transcobalamin (TC- II, TC I) and other R type vitamin B12 proteins in the serum of a patient with treated pernicious anaemia (PA) is reported here for the first time. The dialysed and purified immunoglobulin-G (IgG), but not the immunoglobulin-M (IgM), from a PA patient neutralized the total unsaturated vitamin B12 binding capacity (UB12BC) of human gastric juice, saliva and serum and also of rabbit serum, suggesting that the PA IgG contained blocking antibodies against, IF, TC II, TC I and other R-binders. In addition, the PA IgG and IgM preparations contained binding antibodies since they could form macromolecular complexes with 57Co-B12 bound to IF, TC I or TC II so that each one of the latter was totally excluded from Sephadex G-200. The presence of the binding antibodies was further confirmed by the formation of radioactive precipitation lines on agarose with each one of the vitamin B12-binders bound to 58Co-B12. The PA serum did not exhibit any measurable UB12BC after dialysis against 7.5 M guanidine-HCl followed by renaturation with phosphate buffer (pH 7.4). But it did form TC I and TC II complexes with 57Co-B12 when the latter was added during the renaturation step indicating that the serum contained circulating immunoglobulin-TC complexes. The blocking antibodies should be distinguished from the previously described binding antibodies. The blocking of the binding of vitamin B12 to TCs resulted in relatively lower serum vitamin B12 levels in the present case in contrast to the presence of binding antibodies where high serum vitamin B12 levels have been reported. In addition, the binding antibodies form immunocomplexes with TCs which can easily be detected because they can bind radioactive vitamin B12 while the corresponding immunocomplexes of blocking antibodies are hidden because they prevent the binding of the vitamin to TCs.


Inherited lack of transcobalamin II in serum and megaloblastic anaemia: a further patient. We have studied a patient, unrelated to the patients previously described, with inherited lack of the vitamin B12 binding protein Transcobalamin II. Severe haematological abnormalities were found within a few weeks of birth and responded to treatment with both vitamin B12 and folic acid. He was maintained in partial remission with such treatment until adolescence, except for a time in early childhood when folic acid alone was given and he suffered severe neurological deterioration. A the age of 18 years he was admitted to hospital because of convulsions; the deoxyuridine suppression test showed intracellular deficiency of B12 despite a normal serum B12 and normal haemoglobin concentration. His serum failed to promote the uptake of radioactive B12 by bone marrow cells, and analysis of serum B12 binding proteins demonstrated the lack of Transcobalamin II. Treatment with injections of 1000 micrograms of B12 three times weekly corrected the abnormality shown in the deoxyuridine suppression test; following this treatment, together with changes in anticonvulsive therapy, he remains healthy without occurrence of further convulsions, and is haematologically normal.


Determinants of haemoglobin level in sickle cell-haemoglobin C disease. The determinants of steady state haemoglobin levels in sickle cell-haemoglobin C (SC) disease were investigated by measuring routine haematological and biochemical indices, red cell survival, oxygen affinity, pitted erythrocytes, and red cell and plasma volumes in 31 adult patients (15 male; 16 female). Red cell survival was shortened in all subjects, and was positively correlated with haemoglobin level. However, many haemoglobin values were within the normal range, especially in male subjects. Palpable splenomegaly, which occured in 53% of patients, did not appear to affect haemoglobin level, red cell survival, plasma volume, or red cell volume, but was associated with lower platelet counts and decreased pitted red cells. Sex related differences were found in total haemoglobin, packed cell volume, conductivity cell volume, red cell count, and in the blood volume measurements. Red cell, plasma and total blood volumes in patients varied with weight and cube of height in manner observed in normal subjects, although red cell volumes were lower and plasma volumes were greater than in normal subjects of given height and weight. Anaemia in SC disease is related to the haemolytic rate but the major determinant appears to be an inappropriate increase in plasma volume.


Clinical and laboratory findings in the initial diagnosis of homozygous beta thalassaemia in Fars Province, Iran. The initial clinical and laboratory presentations in 141 cases of homozygous beta thalassaemia in Fars Province, Iran, are presented. About one third of the patients were first diagnosed when they were over 4 years of age. The possible reasons for the high prevalence of the disease in Iran is described.


Viability of red cells stored in diminished concentration of citrate. A comparison was made between the post-transfusion survival of red cells stored in standard ACD-A and in modified ACD-A, containing two-thirds the amount of citrate. Measurements of survival after 28 d storage in both solutions were made in each of six subjects. Mean post-transfusion survival with the two solutions was almost identical. When the results in one subject in whom survival was particularly bad with both solutions were omitted mean values at 24 h were 74.0% for standard ACD-A and 74.9% for modified ACD-A. It is concluded that viability is just as well maintained in modified ACD-A as in standard ACD-A. The results also provide further evidence of large differences between donors with respect to the maintenance of red cell viability during storage.


Splenic irradiation in myelofibrosis: effect on circulating myeloid progenitor cells. We have investigated the mechanism of splenic irradiation-induced granulocytopenia in two patients with myelofibrosis and marked splenomegaly. Serial assays were performed for circulating granulocyte-monocyte progenitors capable of colony formation in vitro (CFU-C). For comparison, similar studies were performed on two patients receiving whole brain irradiation for glioma. Splenic irradiation caused a significant decrease in circulating CFU-C in the myelofibrosis patients. There was no decrease in circulating CFU-C in the brain-irradiated patients. No radiation-induced humoral inhibitor of granulopoiesis and no increased CFU-C radiosensitivity could be demonstrated in the myelofibrosis patients. These observations, taken together with previous data on splenic blood flow and pooling, suggest that the major mechanism of irradiation-induced granulocytopenia in myelofibrosis is destruction of proliferating precursor cells in the splenic tissue and sinusoids.


Platelets and surface-mediated clotting activity. In contrast to previously reported studies, no evidence could be adduced for the activation of Hageman factor (factor XII) by platelets, whether or not these cells had been incubated with adenosine diphosphate (ADP).


Studies on the mechanism of ristocetin-induced platelet aggregation: binding of factor VIII to platelets. The effect of ristocetin on the binding of [125I]factor VIII to platelets was studied. High and low affinity F.VIII binding sites exist on platelets. The high affinity sites bind 13 times more F.VIII than the low affinity sites. Ristocetin increased the binding of F.VIII to both types of binding sites by increasing the affinity of F.VIII for the platelet and increasing the total number of platelet binding sites. Chymotrypsin-treated platelets were not aggregated by ristocetin and F.VIII: these platelets have less of the major platelet membrane glycoproteins and bind much less [125I]F.VIII than do buffer-treated platelets with and without ristocetin.


Transitional myeloproliferative disorder. Eleven patients have been observed with clinical features of both polycythaemia vera and myelofibrosis. Detailed follow-up and repeated haematological and isotopic investigations, including the assessment of erythropoietic distribution by 52Fe scanning, over a 10 year period, have indicated that patients who initially present with this syndrome may remain in a steady state for several years and that this transitional syndrome does not necessarily imply an active or irreversible transformation into classical myelofibrosis. Therapy with iron, folic acid, alkylating agents, splenectomy or splenic irradiation may reduce the extramedullary component of myeloproliferation and allow occasional patients to revert to more classical polycythaemia vera. Radioactive phosphorus (32P) therapy may be inappropriate in polycythaemic patients with dominant extramedullary erythropoiesis, as this form of therapy has a preferential medullary action and may selectively encourage extramedullary myeloproliferation.


The reticulin content of bone marrow in acute leukaemia in adults. Marrow reticulin was studied by trephine biopsy in 44 patients with adult acute leukaemia at presentation and subsequently during the course of their illness. The findings indicate that: (1) an increase in marrow reticulin is common at presentation in patients with both acute lymphoblastic and acute non-lymphoblastic leukaemia; (2) effective anti-leukaemic therapy results in resolution of some or all of the increased marrow reticulin and is not contraindicated, even in patients with a marked increase in marrow reticulin; and (3) reappearance of an increase in marrow reticulin may be a sign of relapse of the leukaemia.


The effect of iron deficiency on whole blood viscosity in polycythaemic patients. Iron deficiency leads to a significant increase in whole blood viscosity in polycythaemic patients. This can be corrected by simultaneous treatment with iron and venesection. In patients with polycythaemia secondary to hypoxia the haemoglobin concentration may be increased by treating coexisting iron deficiency, without altering the whole blood viscosity, thus increasing oxygen availability to the tissues. Values for whole blood viscosity can be derived from the peripheral blood Hb and MCH, allowing therapeutic decisions to be made on the basis of a simple haematological examination.


Abnormal mitochondrial DNA in acute leukaemia and lymphoma. Electron microscopic examination was carried out on mitochondrial DNA molecules isolated from leucocytes in seven cases of acute leukaemia or leukaemic-phase poorly-differentiated lymphocytic lymphoma. There was a marked shift from the predominant circular monomeric form in normal leucocytes to circles with twice the normal circumference, as well as multiple interlocking circles in two of the four cases of untreated acute leukaemia, and in one of untreated lymphoma. This abnormal pattern of mitochondrial DNA evidently reflects an intrinsic aberration in the processing of mitochondrial DNA in some leukaemias and lymphomas, as it occurred in the absence of prior therapy with alkylating agents known to interact with DNA. Up to 47% of total mitochondrial DNA was present in such complex forms, which on steric grounds should be unsuitable as a template for replication of free monomers and possibly for messenger RNA production. The latter may be pertinent to previously reported abnormalities in acute leukaemia leucocytes which could be related to abnormal production of gene products of mitochondrial DNA.


Impaired microtubule assembly and polymorphonuclear leucocyte function in the Chediak-Higashi syndrome correctable by ascorbic acid. It was previously shown that the abnormal surface characteristics and defective bactericidal function of polymorphonuclear leucocytes (PMN) in the Chediak-Higashi syndrome (CHS) are correlated with impaired microtubule assembly, and in one patient direct electron microscopic evidence for an anomaly in microtubule assembly following surface membrane activation by concanavalin A (Con A). We show that very few microtubules are visible in CHS leucocytes from two additional patients under conditions where normal PMNs contain abundant microtubules, and that both in vivo and in vitro exposure of the CHS leucocytes to ascorbic acid promotes the assembly of microtubules. This agent, which normalizes chemotaxis and degranulation in CHS leucocytes, is shown also to correct granulocyte adherence in these leucocytes. It is suggested that the improved clinical course of patients with CHS following treatment with ascorbic acid is related at least in part to improvement of microtubule assembly and PMN function by the ascorbic acid.


Typical hairy-cell leukaemia with IgGk paraproteinaemia. A case of hairy-cell leukaemia (HCL) with IgG(k) paraprotein is described. The typical clinico-pathological features of the patient are stressed, and it is shown that the hairy cells (HCs) were producing and secreting IgGk. The case is placed in a more general context by the demonstration that HCs from other typical cases of HCL produce and secrete IgG. These findings conclusively demonstrate that HCL is a B-cell disease.


Junctional structures in haemopoiesis: a study of bone marrow using freeze-fracture and lanthanum impregnation techniques. Intercellular regions of contact in the haemopoietic compartment of normal rat bone marrow were studied using freeze-fracture and lanthanum tracer techniques. Small adhering junctions (like desmosomes and their variants) were found between haemopoietic and stromal cells but tight, gap or septate junctions could not be identified. These findings are in agreement with the concept that extensive junctional structures may be inconsistent with orderly development of this transient cell system, preventing the delivery of mature cells into the circulation and resulting in ineffective haemopoiesis. Occasionally 'pinching off' of a portion of the cytoplasm of erythroid cells by stromal cells was seen, providing a means for intercellular communication. Structures similar to intercellular bridges responsible for direct intercellular communication were also seen.


Studies of ineffective erythropoiesis and peripheral haemolysis in congenital dyserythropoietic anaemia type II. Erythrokinetic parameters were estimated in six patients suffering from congenital dyserythropoietic anaemia type II (CDA II) by means of a mathematical model of iron kinetics. A wide variation in effectiveness of erythroid activity was observed, and a significant negative correlation was found between ineffective erythropoiesis and peripheral haemolysis. In four patients with prominent peripheral haemolysis, splenectomy was carried out. Marked improvement in their clinical condition and in haemoglobin level resulted.


Phagocytosis of nucleated and mature beta thalassaemic red blood cells by mouse macrophages in vitro. Physiological or experimental decrease in sialic acid (SA) content on the red blood cell (RBC) membrane is believed to play an important role in the recognition of these cells by macrophages. Since there is a 20-30% decrease in the SA content on the membrane of thalassaemic RBC, the interaction between macrophages and these RBC was studied in vitro. Using mouse peritoneal macrophages, it was found that these macrophages 'recognize' and phagocytize thalassaemic RBC while RBC from normal donors are hardly phagocytized. The average level of phagocytosis of thalassaemic RBC from splenectomized patients was found to be 22-fold higher than that of RBC from normal donors. The phagocytized cells consisted of both mature and nucleated RBC. Mouse peritoneal macrophages seem to be a useful in vitro system for the study of the accelerated sequestration and shortened life span of thalassaemic RBC.


Fluxes of plasma transcobalamins following saturating doses of vitamin B12 in man. The three vitamin B12 binding proteins in plasma were saturated with vitamin B12 by an intravenous injection of 57Co-vitamin B12. All three unsaturated vitamin B12 binding proteins reappeared in plasma in detectable amounts within 15 min of the clearance of unbound vitamin B12 from plasma.


Glucose-6-phosphate dehydrogenase deficiency and neonatal jaundice in Jamaica. Glucose-6-phosphate dehydrogenase (G6PD) deficiency was detected in 16 (69.6%) of a group of 23 neonates who had unexplained moderate or severe jaundice. This proportion is significantly more than the 9.4% observed or the 22.2% expected in Jamaican neonates who are not moderately or severely jaundiced (P less than 0.003), and significantly more than the 12.6% observed or the 21.0% expected in older Jamaican children and adults (P less than 0.003). Phenobarbitone therapy and phototherapy reduced the need for exchange transfusion but this was necessary in eight patients. Two babies developed kernicterus and one died. On the other hand, only two of 21 neonates who were identified as G6PD deficient at birth subsequently became moderately or severely jaundiced, and this could be attributed to other causes in both cases. These findings indicate that apparently spontaneous neonatal jaundice is important in infants who have the G6PD A--enzyme. However, the jaundice is probably precipitated by unknown factors to which the G6PD deficient neonate is more susceptible than the infant who is not G6PD deficient. THere is also a slightly increased incidence of G6PD deficiency in neonates who develop jaundice because of ABO or Rh(D) iso-immune disease, infection or prematurity.


Storage pool disease: comparative fluorescence microscopical, cytochemical and biochemical studies on amine-storing organelles of human blood platelets. The platelet content of ATP, ADP, serotonin (5-HT), dopamine, noradrenaline and adrenaline as well as the net uptake of radiolabelled 5-HT and mepacrine were subnormal in six patients with Storage Pool Disease (SPD). Fewer amine-storing organelles were found by fluorescence microscopy with the fluorescent probe mepacrine and by electron microscopy with a cytochemical (uranaffin) reaction specific for 5'-phosphonucleotides. Both methods showed that SPD platelets have atypical organelles with a reduced capacity to store amines, 5'-phosphonucleotides and mepacrine. The changes were most marked in platelets of the two patients who also had oculocutaneous albinism.


A cohort study of mortality and cancer incidence in ethylene oxide production workers. Ethylene oxide, important as an intermediate product in the chemical industry and for sterilising hospital equipment, is mutagenic in several organisms; carcinogenicity has been suspected although this had not been supported by clinical data. Ethylene oxide has been produced by a Swedish company since the beginning of the 1940s. This paper describes a cohort study of the mortality and the cancer incidence among full-time exposed workers in ethylene oxide production, a group of maintenance workers with intermittent exposure and a group of unexposed controls. Investigation of the production processes in the building at different times has shown that workers were exposed to ethylene dichloride, ethylene chlorohydrin, ethylene, and small amounts of bis-(2-chloroethyl) ether as well as to ethylene oxide and traces of other chemicals. The full-time exposed cohort shows a considerable excess mortality deriving mainly from increased mortality from tumours and also from diseases of the circulatory system. The cancer incidence study, including living persons with malignancies, showed a significant excess in the full-time cohort. Of the 16 patients with tumours in the two more exposed cohorts there were three cases of leukaemia, six of tumours in the alimentary tract and four of urogenital malignancy. The excess mortality and cancer incidence cannot be attributed to any particular chemical in the production process, but ethylene oxide and ethylene dichloride are the prime suspects.


UK Naval Dockyards asbestosis study: survey of the sample population aged 50-59 years. As part of a general morbidity study of all civilian employees in the four Royal Naval Dockyards, the clinical, radiological and physiological effects of exposure to asbestos in 1200 men aged 50-59 years were studied in detail. The sample included all men on the Register of Asbestos Workers, one in three of those currently in occupations where intermittent exposure to asbestos may occur, and one in 30 of the remainder. The conclusions are mainly in accord with those of the comprehensive morbidity study of all the civilian dockyard workers, and show that smoking played a large part in increasing prevalence rates of radiographic, clinical, and physiological abnormalities in this population. A sub-group of 39 men, who were working as asbestos laggers or sprayers before 1957, was identified. These men showed much more extensive disease than any other sub-group, yet, even so, the smokers were worse than the non-smokers. Of these smokers, 48% had small opacities of category 1/1 or more, 76% reported that they coughed during the day and 53% had crepitations; forced expiratory volume and transfer factor were also markedly reduced in these 21 smokers. Although asbestos exposure had been intermittent for the majority of the population, the prevalences of pleural thickening, small opacities, current respiratory symptoms and crepitations were shown to be related to duration of exposure to asbestos.


Oral and pharyngeal cancer in the North-west and West Yorkshire regions of England, and occupation. Patients with oral or pharyngeal cancer in the two main textile regions of England were matched for age and sex with patients having cancers not known to be associated with textile work. Data were recorded on age, sex, cancer site, and smoking, chewing and drinking habits together with dental and occupational history. There were 102 and 61 matched pairs of males and 52 and 60 matched pairs of females in the North-west and West Yorkshire regions respectively. There were significantly (P less than 0.05) more textile workers in the cases compared with their matched controls for only the females in the North-west. No particular type of textile work occurred more frequently for the cases than the controls in all four matched comparisons. Only for the males in the North-west were there significant differences (P less than 0.05) in the proportions of textile workers in the three cancer sites of the tongue, mouth and pharynx. These results do not confirm the association between textile work and oral or pharyngeal cancer found by the mortality study of Moss and Lee (1974). The results for the association between oral or pharyngeal cancer and smoking, drinking, chewing and wearing of dentures are discussed.


Mill effect and dose-response relationships in byssinosis. Four hundred and eighty-six textile workers in three cotton mills and one wool/synthetic mill were studied for symptoms and functional effects of workroom exposure to dust. Byssinosis was found in 5.7% of 386 cotton workers, with an apparent threshold level of 0.5 mg cotton dust/m3 of air. Mean post-shift functional declines were greater in workers exposed to greater than or equal to 0.2 mg/m3. Workers with byssinosis were unequally distributed, however, with respect to job category and mill; and these variables, rather than current dust exposure levels, accounted for the observed distribution of byssinosis prevalence rates. Variation in biological potency of different samples of cotton dust could be responsible for 'mill effect', the residual variation in response rates by mill after controlling for variation due to dust exposure. A number of other potential influencing variables that are likely to be distributed unequally by mill should also be considered. Mill effect should be assessed in large-scale studies of byssinosis, most of which have analysed biological response rates by combining mill and other variables to examine first-order effects of dust dosage. In such analyses, much of the observed variability may be due to factors other than dust dosage.


Occupational lead poisoning in the United States: clinical and biochemical findings related to blood lead levels. Dose-response relationships between blood lead levels and toxic effects have been evaluated in 160 lead workers in two smelters and a chemicals plant. Blood lead levels ranged from 0.77 to 13.51 mumol/litre (16-280 microgram/dl). Clinical evidence of toxic exposure was found in 70 workers (44%), including colic in 33, wrist or ankle extensor muscle weakness in 12, anaemia (Hgb less than 8.69 mumol/litre (Hb/4) or 14.0 gm/dl) in 27, elevated blood urea nitrogen (greater than or equal to 7.14 mmol/litre or 20 mg/dl) in 28, and possible encephalopathy in two. No toxicity was detected at blood lead levels below 1.93 mumol/litre (40 microgram/dl). However, 13% of workers with blood lead levels of 1.93 to 3.81 mumol/litre (40-79 microgram/dl) had extensor muscle weakness or gastrointestinal symptoms. Anaemia was found in 5% of workers with lead levels of 1.93-2.85 mumol/litre (40-59 microgram/dl), in 14% with levels of 2.90 to 3.81 mumol/litre (60-79 microgram/dl), and in 36% with levels greater than or equal to 3.86 mumol/litre (80 microgram/dl). Elevated blood urea nitrogen occurred in long-term lead workers. All but three workers with increased blood urea nitrogen had at least four years occupational lead exposure, and nine had received oral chelation; eight of this group had reduced creatinine clearance, and eight had decreased renal concentrating ability. These data support the establishment of a permissible biological limit for blood lead at a level between 1.93 and 2.90 mumol/litre (40-60 microgram/dl).


5-aminolevulinate dehydratase activity in blood of rabbits given tin or lead. The activity of 5-aminolevulinate dehydratase (ALAD) in rabbit blood is significantly inhibited by tin. Intravenous administration of tin (0.48 or 4.8 mumol/kg body weight) causes a decrease in the activity of the enzyme by 60% or 94% respectively. The effects of tin and lead on ALAD differ: inhibition by tin is not affected by pre-incubation at 50-60 degrees C, whereas the inhibitory effect of lead is increased by the same pretreatment. The optimum pH for rabbit blood ALAD is 6.8 in control rabbits. This optimum shifts to pH 5.8-6.0 in the blood of tin-treated rabbits, with or without pre-incubation at 60 degrees C for 5 min, while a similar shift is prevented by the same pre-incubation after lead treatment. Recovery to normal activity is faster after tin than after lead treatment.


The distribution and metabolism of nickel carbonyl in mice. The distribution of 63Ni- and 14C-labelled nickel carbonyl was studied in mice by whole-body autoradiography and by liquid scintillation counting. Radioactivity from Ni(14CO)4 was found almost exclusively in the blood, probably because of the formation of 14CO-haemoglobin. After the administration of 63Ni(CO)4 the highest level of 63Ni was found in the lung. Other tissues accumulating a high amount of 63Ni were the brain and spinal cord, the heart muscle, the diaphragm, brown fat, the adrenal cortex and the corpora lutea of the ovaries. A high level of 63Ni was also present in the kidneys and the urinary bladder. Experiments designed to establish whether the nickel in the lung, the brain, the heart muscle and the blood was present in a non-ionised form, or as a cation, suggest that nickel is bound to these tissues in the cationic state (Ni++).


Aspects of the patient intake process in a psychotherapy clinic. Recent interest in psychotherapy services in the National Health Service has raised questions regarding the availability of existing psychotherapy facilities. In attempting to answer some of these questions, a study was made of aspects of the referral and assessment segments of the intake process of 180 patients referred in 1975 to the Paddington Centre for Psychotherapy Adult Out-patient Department. Of this group, 137 were referred for individual psychoanalytically oriented psychotherapy, 82 of whom were offered assessment interviews, 45 offered treatment and 40 actually began treatment during the study period. An additional seven patients originally assessed for group therapy were offered and began individual treatment. Some characteristics of the referral population, the referring agencies, the effects of a waiting list, and the phenomenon of dropouts are discussed and compared with findings from other Centres.


Some psycho-social consequences of multiple sclerosis: problems of social interaction and group identity. The study was concerned with the psycho-social consequences for married couples of multiple sclerosis being contracted by one of the partners. In particular, problems of social interaction and group identity were explored. In determining their mode of interaction with healthy people such couples can choose between normalizing, i.e. endeavouring to carry on their relationships with other people according to their pre-illness pattern, or of disassociating, i.e. turning away from former associates and seeking a new peer group among others with like affliction. In nearly every case husband and wife agreed on the choice of stratagem, a majority of the couples forming the sample opting for disassociation. Membership of the Multiple Sclerosis Society was much more usual among the disassociating couples than among those 'normalizing'. The variables of age, sex, social class and severity of illness were not found to affect the mode of interaction, whereas place of residence and medical interest in them, as perceived by patients and their spouses, were influencing factors.


Compensation-neurosis and the psycho-social requirements of the family. This paper discusses the application of basic theories of family functioning to understanding the syndrome consisting of abnormal-illness behaviour centred around a recompensable illness or injury. It sets out the socio-cultural matrix out of which it arises and postulates that compensation-neurosis may be viewed as a homeostatic response of the family system when major psycho-social requirements are not being met and the family is under stress or in crisis. It looks at two common paradigms of compensation-neurosis as met in the rehabilitation unit of a large hospital, and at the application of the theory, and gives further examples of homeostatic adjustments to meet family requirements such as those of attachment. It also uses group and inter-group dynamics to further clarify the syndrome in psycho-social terms. It goes on the discuss the implications of these theories for prevention and management of this difficult syndrome.


Locus of control and contraceptive knowledge, attitudes and practice. A series of 100 interviews with women attending ante-natal clinics at two Sydney public hospitals assessed their contraceptive knowledge, attitudes, and practice and locus of personal control (whether they believed they controlled their own lives). Multiple regression analyses showed that locus of control was significantly related to their attitudes to contraception, but not to their contraceptive knowledge or practice. The implications of that finding for family planning programmes and sex education are discussed.


Cultural differences in body perception during pregnancy. A longitudinal study of body image change during pregnancy was conducted to test what aspects of body perception are sensitive to psychological change. Fifty-five black and 30 white women who were primiparous, less than 4 months pregnant and at least 17 years old, were interviewed during their first and third trimester as well as 6 weeks post partum. Awareness of one's stomach as measured by the Stomach Focus score of the Body Focus Questionnaire was sensitive to body changes which accompany pregnancy. However, the black women did not change in awareness of their stomachs following delivery as the white women did. The Body Distortion Questionnaire revealed that the black women felt most distorted at 9 months of pregnancy but the white women declined in body distortion. Both groups reported less distortion following parturition. Thus, cultural as well as psychological and physiological factors influence the way in which the body is perceived and experienced during pregnancy.


The reasons people give for taking overdoses: a further inquiry. A representative sample of 41 cases of self-poisoning was studied in depth. In each case 'reasons' for taking the overdose, both stated spontaneously and chosen from a presented list, were recorded. The commonest spontaneous reason was the 'wish to die'. Nearly one-third indicated some non-suicidal purpose early in the interview and consistently denied suicidal intent subsequently. Apart from suicidal intent, reasons chosen from the list bore little resemblance to reasons that had been offered earlier in the interview and are therefore of uncertain relevance. Three psychiatric judges attributed reasons for each case based on common-sense criteria. Several reasons were seldom or never chosen by them; four were chosen frequently with good agreement, i.e. communicating hostility, influencing others, relieving a state of mind and suicidal intent. The first two were the most frequently chosen, attributed to 71 per cent and 54 per cent of cases respectively. They were the reasons chosen least frequently by the self-poisoners themselves. Of 23 (56 per cent) subjects indicating suicidal intent, 12 (29 per cent) were judged to be suicidal by psychiatrists. These were not clearly distinguishable on the basis of their original interviews, except that those judged suicidal tended to indicate suicidal intent early in the interviews. The clinical and research implications of these findings are discussed.


The border between the paranoid-schizoid and the depressive positions in the borderline patient. In this paper some of the mental mechanisms deployed by borderline patients are described and illustrated with clinical material. It is suggested that the term borderline has three distinct but related meanings. First, it refers to a clinical category of patients, borderline between neurosis and psychosis who, while not frankly psychotic, tend to use psychotic mechanisms. Second, it refers to a metaphor representing the subjective experience of these patients who are unable to find a permanent identity but feel themselves sitting on the fence between a variety of different identities in a borderline position. Third, it can refer to a theoretical formulation of the level of development at which these patients function. I propose that in terms of mental mechanisms, they function as if on the border between the paranoid-schizoid and depressive positions as outlined by Melanie Klein. Some of the consequences of the failure to experience and work through depressive anxieties are discussed.


Psychosexual personality traits, fixation and neuroticism. Three tests of oral and anal psychosexual personality traits, OOQ, OPQ and ai3Q, together with the EPI were administered to 128 subjects, to test the hypothesis that psychosexual fixation was related to neuroticism. This hypothesis was supported by the results.


Detection of fetal risk in postmaturity. Ninety-seven postmature pregnancies were monitored by amnioscopy or amniocentesis (to determine presence or absence of meconium), oxytocin challenge tests (OCT), 24-hour urinary oestriol estimations and fetal movement counts. The colour of the amniotic fluid and the result of the OCT predicted almost all cases of fetal distress in labour and infants with low Apgar scores. Oestriol estimations and fetal movement counts predicted fetal distress only when combined with other positive tests. Of 50 patients with no abnormal test results, 49 had uneventful labours. The Caesarean section rate was not above average and all babies were liveborn.


Dynamic fetal cephalometry.

Dynamic fetal cephalometry. An iterative method of fetal cephalometry for use with real time scanners is described using a flow chart. The method is shown to be capable of yielding measurements having a standard deivation of less than 1 mm and we have found it to be superior to the combined A and B scan technique from which it is derived.


Amniotic fluid optical density determination as a rapid test for assessment of fetal lung maturity. The lecithin/sphingomyelin (L/S) ratios and optical densities at 650 nm were determined for 158 samples of amniotic fluid obtained by amniocentesis. A further 24 samples collected by vaginal aspiration from patients with spontaneous rupture of the membranes were also analysed. The relation between the L/S ratio and the optical density suggests that the more rapidly obtainable optical density measurement could be used as a screening procedure for fetal pulmonary maturity. A valid estimate of maturity by optical density is not possible in amniotic fluid aspirated from the vagina.


The effects of ergometrine on the lower oesophageal sphincter tone at caesarean section. The effect of intravenous ergometrine 0.5 mg during general anaesthesia for Caesarean section on lower oesophageal sphincter (LOS) function was investigated in eight patients. Ergometrine increased the LOS pressure markedly (p less than 0.005).


Chlormethiazole treatment and breast feeding. Four mothers receiving chlormethiazole for pre-eclampsia and their babies were the subjects of the investigation. Blood samples at delivery and blood and breast milk samples in the postpartum period were analysed for chlormethiazole. Concentrations ranged from 1.340 to 1.640 micrograms/g of sample of umbilical artery blood at birth, and fell to 0.010 to 0.153 micrograms/g in capillary blood 20 to 26 hours later. After the start of breast feeding, chlormethiazole in the babies was detectable in only 3 out of 27 serial blood samples and was 0.018, 0.009 and 0.006 micrograms/g. The highest calculated amount of chlormethiazole ingested at a breast feed was 37.2 micrograms. It is suggested that breast feeding should not be delayed solely on account of chlormethiazole therapy.


The effect of an injectable progestogen contraceptive on blood coagulation and fibrinolysis. In 26 women receiving either medroxyprogesterone acetate (Depo-Provera) injections or combined oestrogen-progestogen pills for contraception, tests of coagulation and fibrinolysis were performed before treatment, and after 8, 16 and 24 weeks of therapy. In the medroxyprogesterone group no significant changes were induced in fibrinogen, the vitamin K-dependent factors, or antithrombin III. Plasminogen levels fell during therapy, and were significantly lower than pre-treatment values after 16 and 24 weeks. By contrast, the 13 women receiving oral contraceptives showed raised levels of fibrinogen and plasminogen after 8 weeks of treatment, and of factors VII and X after 24 weeks. These data suggest that medroxyprogesterone acetate injections induce fewer changes in the blood coagulation system than oral contraceptives.


The effect of menopausal status and sequential mestranol and norethisterone on serum cholesterol, triglyceride and electrophoretic lipoprotein patterns. The serum cholesterol, triglycerides and electrophoretic lipoprotein patterns of 35 postmenopausal women, who subsequently received sequential mestranol and norethisterone, were compared with those of 35 premenopasual women of the same age and weight. The postmenopausal women had a significantly higher level of serum cholesterol (p less than 0.01) than the premenopausal women, and a significant reduction (p less than 0.001) occurred in this group after two months of therapy. There was no significant difference in level of serum cholesterol between the premenopausal group and the postmenopausal group receiving sequential mestranol and norethisterone for two months. The serum triglycerides were not significantly higher in the postmenopausal group but there was a significant increase (p less than 0.001) after two months of therapy. The marked alteration in lipid levels at the menopause may in part account for the great increase in coronary artery disease in postmenopausal women but whether these changes are reversible by giving hormone therapy remains speculative.


Diagnostic accuracy of the MiMark endometrial cell sampler in 101 patients with postmenopausal bleeding. The efficacy of the MiMark endometrial cell sampler in the cytological assessment of endometrium was evaluated in 101 patients with postmenopausal bleeding. The apparatus was successful in daignosing all but one of the endometrial carcinomas in the series. Reports of its accuracy in diagnosing endometrial hyperplasia and other endometrial pathology cannot be substantiated.


Acute proliferative glomerulonephritis with crescents and renal failure in pregnancy successfully managed by intermittent haemodialysis. Case report. A 26-year-old patient with no previous history of renal disease developed acute non-streptococcal crescentile glomerulonephritis with severe renal failure in the 17th week of her second pregnancy. It became necessary to treat her with haemodialysis to maintain the blood urea around 25 mmol/l. The haemoglobin was maintained above 9 g/dl with regular blood transfusion and the blood pressure was controlled with hypotensive drugs. Measurement of fetal biparietal diameter and human placental lactogen indicated normal fetal growth and placental function. The patient spontaneously delivered a healthy infant at 32 weeks. Haemodialysis requirements decreased post partum and the patient even managed without dialysis for 12 weeks. Renal function, however, remained severely impaired and maintenance haemodilysis was again necessary at nine months post partum. Glomerulonephritis complicating pregnancy is reviewed and the management of acute and chronic renal failure in pregnancy is discussed.


Haemangioma of the fallopian tube. Case report. I present the sixth report of a patient with a haemangioma of the Fallopian tube and the first from the United Kingdom. The patient presented with an acute abdomen due to haemoperitoneum.


Fertility in women with Turner's syndrome. Case report and review of literature. A successful pregnancy in a woman with Turner's syndrome with a 45,X/46,XX karyotype is described. The literature contains reports of a total of nine pregnancies in seven women with a 45,X karyotype and 56 pregnancies in 23 women with mosaicism and a 45,X cell line, as well as a 46,XX and/or 47,XXX cell line. Fifteen of the latter 56 pregnancies ended in spontaneous abortion (27 per cent), and four ended in the delivery of a stillborn child; 12 of the 37 liveborn infants (32 per cent) had a physical or mental abnormality, and 8 (22 per cent) had a chromosome abnormality. Three had Down's syndrome, and five had a 45,X cell line. Due to the relatively high (8 per cent) incidence of Down's syndrome among liveborn infants of women with Turner's syndrome, amniocentesis for fetal karyotyping should be advised.


Subjective recording of fetal movement.

Subjective recording of fetal movement. A group of 137 patients, 113 of whom had obstetric complications, recorded fetal movements by a subjective method. Low fetal movement counts were associated with maternal cigarette smoking and prolongation of pregnancy and high counts with maternal ingestion of sedatives or tranquillizers, abnormal fetal heart rate in labour and a true knot in the umbilical cord. The absence of fetal movement during four consecutive 20-minute counting-sessions was not associated with poor fetal outcome. Further investigations to assess the usefulness of fetal movement counting are recommended. Such investigations should take into account the limitations imposed by the methods and the obstetric population for study.


Effect of amniotomy on fetal breathing movements. Fetal breathing movements were recorded by real-time ultrasound before and after artificial rupture of the membranes. Fifteen normal pregnancies between 39 and 41 weeks gestation were studied. A significant increase in breathing incidence and maximum breathing rate was observed in the first 10 minutes after amniotomy.


Amniotic fluid squalene and fetal maturity. Gas chromatographic profiles of neutral lipids in amniotic fluid pellets were analysed for 51 specimens collected from patients in the last two months of pregnancy. The most noticeable change was a large increase in squalene relative to other components in samples at term. By expressing data as a ratio of squalene to cholesterol (S/C), it was possible to accurately predict which amniotic fluid specimens came from patients whose pregnancies were of a gestation of 40 weeks or later. Highest values for S/C and for squalene were obtained for pregnancies which were several weeks overdue.


Poly-plethysmographic study on the effects of ritodrine on the cardiovascular system of patients in labour. The effects of ritodrine infusion on the cardiovascular system of six women in threatened or premature labour are reported. In contrast to other betamimetics, ritodrine caused a moderate rise in systolic blood pressure, the corresponding fall in diastolic pressure leading to a widened pulse pressure but no risk of hypotension. Ritodrine caused a rise in cardiac output, and was well tolerated by the patients. Special care should be taken in treating patients with known heart disease.


The distribution of polyamine oxidase activity in the fetomaternal compartments. Polyamine oxidase activity was measured in different compartments of the feto-maternal unit by a radiochemical method. The activity in the retroplacental serum (mainly of intervillous origin) was 20 to 30 times higher than in maternal uterine or peripheral venous blood sera. No activity was found in the fetal cord blood sera. The enzyme level in the maternal peripheral sera fell to undetectable levels within 72 hours post partum. Preliminary data indicate that the enzyme might be produced by the decidua rather than by the placenta. It is suggested that the enzyme may constitute an important part of a supposed local immunological barrier formed at the placental bed to help to protect the fetal allograft from maternal immune rejection through a local suppressive effect on maternal cellular immunity.


Effect of lisuride on inhibition of lactation and serum prolactin. Lisuride, a new semisynthetic ergot derivative, was given to 53 women to inhibit lactation; 26 women had 300 micrograms daily and 27 had 600 micrograms daily for seven days. Eight lactating women acted as controls. Lisuride effectively inhibited lactation and also suppressed the serum prolactin levels; the latter effect was dose related. Lisuride produced no untoward side effects.


Association of juvenile disciform maculopathy with HLA B15. Twenty patients with juvenile disciform maculopathy (JDM), which clinically cannot be differentiated from presumed ocular histoplasmosis, are presented. Histocompatibility antigen typing showed an increase in HLA B15, but this increase was not significant with respect to the corrected P-value. We are reporting our results in the hope of encouraging those who have cases of JDM in Europe to consider histocompatibility antigens and in particular HLA B15.


The inferior oblique as muscle of choice for biopsies of extraocular muscles. Suitable biopsies can easily be taken from the inferior oblique muscle without unwanted side effects from the belly of this muscle, allowing complete examination by light and electron microscopy. The inferior oblique is the muscle of choice for biopsy studies of extraocular muscle.


Tissue response to the Fadenoperation.

Tissue response to the Fadenoperation. The Fadenoperation was performed on 24 rabbit eyes. In 8 eyes the globe and muscle were removed intact and in 16 eyes the muscle was dissected from the sclera to determine the site and degree of attachment. The greatest degree of adherence was found between the muscle and the sclera at the site of the suture, less attachment at the lateral and medial border of the muscle, less in the central area close to the suture site, and least in the central anterior area. The Fadenoperation creates adherence of the muscle to the sclera. Its clinical usefulness will, however, depend on clinical evaluation.


The intraocular penetration of cefuroxime after parenteral administration. Cefuroxime (Zinacef) is a new second generation cephalosporin which is resistant to beta-lactamases produced by both Gram-negative and Gram-positive organisms, with an antibacterial spectrum that includes practically all likely ocular pathogens except pseudomonas. It is shown to penetrate into the eye after intravenous (1.5g) or intramuscular (1 g) injection and achieve therapeutic concentrations, with absence of side effects. Cefuroxime is therefore a useful antibiotic for ophthalimic infections and should have a role in combination with gentamicin in intraocular infections, particularly those of unknown aetiology.


Systemic absorption of topically applied chloramphenicol eyedrops. Five children under the age of 9 years had topical chloramphenicol drops administered 2-hourly to each eye for 5 to 7 days. Systemic absorption was not detected by 2 sensitive assays for the drug. The hazards of topical chloramphenicol and reports in the current literature are discussed.


Systemic absorption of topical and subconjunctival gentamicin. Ten patients received ocular gentamicin therapy topically or subconjunctivally. Systemic absorption was not detected after topical use but was detected after subconjuctival administration. The relative safety of ocular gentamicin therapy is discussed and the literature is reviewed.


Lipoid proteinosis (Urbach-Wiethe syndrome). A Jewish-Iranian family suffered from lipoid proteinosis. The 8 affected siblings were from consanguineous matings and presented a wide range of phenotypic expressions. Minimal manifestations in 2 heterozygote carriers and the possibility of autosomal recessive inheritance are discussed.


Orbitofacial mucormycosis with unusual pathological features. A 52-year-old man with mild diabetes and acute stem cell leukaemia developed an orbitofacial mucormycosis. Cultures showed the fungus to be Rhizopus oryzae. Vigorous treatment with amphotericin B and other bactericidal and bacteriostatic antibiotics for a concurrent sepsis failed to suppress the infections, and the patient died. On post-mortem examination characteristic haematoxylin-staining, broad, aseptate fungal hyphae were found in the right eye, orbit, and lung. A striking and unusual feature of this case is the presence of brightly birefringent crystals within the severely degenerated eye. These were found by histochemical staining and x-ray diffraction studies to be calcium salts of fatty acids, apparently liberated from necrotic adipose tissue of the orbit.


Ophthalmological features of Aicardi's syndrome: report of two cases. Two Greek female patients with Aicardi's syndrome are presented. The clinical picture, electroencephalogram, computer axial tomography scan, and the ophthalmological findings in these patients are described. The ocular features are emphasised because they can establish the diagnosis of this rare syndrome.


Corneal ulceration following measles in Nigerian children. Acute corneal ulceration in malnourished children is the commonest cause of childhood blindness in Northern Nigeria and usually develops after measles. Other severe diseases in malnourished children rarely precipitate corneal ulceration. A survey in a school for blind children showed that 69% of the children were blind from corneal disease, and a survey of children with corneal scars showed that at least 42% were caused by ulceration after measles. The clinical appearance of the active ulcers was very varied. The serum retinol-binding protein and prealbumin levels in children with corneal ulcers following measles were below normal, but a group of malnourished children without eye complaints following measles were found to have even lower levels. Thus a specific deficiency of vitamin A does not appear to be the primary cause of these ulcers, though it may be a contributory one. A specific measles keratitis and secondary herpes simplex infectious may be local factors contributing to this ulceration, and there is nearly always a background of protein calorie malnutrition. Racial factors may also be of some significance.


Xenon arc panretinal photocoagulation for central retinal vein occlusion: a randomised prospective study. Thirty-three patients with central vein occlusion were evaluated for the effects of scatter xenon arc panretinal photocoagulation. Thirty-four eyes (2 eyes of 1 patient) were randomly divided into a treatment (15 eyes) and a nontreatment group (19 eyes). The average follow-up per eye has been 29 months. The visual prognosis was not significantly better in either group. There was no difference in the development of fundus neovascularisation between groups. None of the patients in the treated group developed rubeosis or neovascular glaucoma. Two patients in the nontreatment group initially had rubeosis and 3 developed it after entry. All 5 involved eyes developed neovascular glaucoma. A significantly greater amount of central retinal capillary drop-out was present in the untreated eyes that developed rubeosis than those untreated eyes which did not. The eyes in the treated group had a similar range of capillary drop-out area, but none of these eyes developed rubeosis or neovascular glaucoma. Panretinal photocoagulation prevented the development of rubeosis and neovascular glaucoma in susceptible eyes.


Metastatic tapioca iris melanoma.

Metastatic tapioca iris melanoma. A case of metastatic tapioca melanoma of the iris in a 12-year-old girl is reported. The patient had heterochromia, a red painful eye, and was treated for iritis with secondary glaucoma. In the course of 5 months iris lesions with the clinical appearance of tapioca pudding developed, and biopsy disclosed a melanoma. The eye was immediately enucleated, and pathological examination showed a melanoma with predominantly epithelioid-type cells which had infiltrated the angle, the posterior chamber, and the surgical wounds. Conjunctival extension was noted 10 months after enucleation, and regional lymph node metastases were found 4 months later. Previously reported cases are reviewed and compared with the present case.


Microcysts of the human iris pigment epithelium. Microcysts of the iris pigment epithelium have been described in association with diabetes mellitus, systemic mucopolysaccharidoses. Menkes's syndrome, and in neonates. Our study covers 68 cases obtained at necropsy. We specifically examined the iris pigment epithelium for vacuolation. We found that microcysts are more widespread than previously thought. In our series 57.3% of the cases reviewed by the light microscope showed microcysts. Of interest was the relationship of malignant neoplasm to iris pigment epithelium microcyst: 69.4% of cases with malignancy showed microcyst, whereas only 30% of the cases without neoplasms showed microcysts. Patients treated with exogenous steroid also had a raised incidence of microcysts.


Cauterising iris scissors.

Cauterising iris scissors. The cauterising iris scissors described here are a modification achieved by suitably insulating the standard De Wecker's iris scissors. This modification provides in addition to cutting an advantageous cauterising effect, which could prove useful in the surgery of eye conditions with high risk of bleeding or metastasis. It utilises the optimum electric current range of 20-40 mA.


Juxtapapillary choroiditis in association with rising antichlamydial antibody. We present the case of a 21-year-old girl with a uniocular juxtapapillary choroiditis. During the course of her illness the titre of antichlamydial IgG increased from 1/32 to 1/4096 against Chlamydia trachomatis TRIC serotypes J and C, and antichlamydial IgM appeared in her blood. Toxoplasma dye test was positive at a level of 1/128 but no increase in the titre of antibody was detected during the course of her infection. The relevance of these findings to her ocular lesion is discussed.


Lysophosphatidyl choline in the aqueous humour during ocular inflammation. Phospholipase A and lysophosphatidyl choline (LPC) have been shown to induce significant changes in the lens permeability in vitro to cations and soluble proteins. During uveal inflammation, in various experimental models and in man as well, the levels of LPC in the aqueous humour have been shown to reach values which are harmful to the lens in vitro. In addition, a phospholipase is thought to be activated during the antigen + antibody + complement sequence. The possible significance of these findings is discussed in relation to the pathogenesis of complicated cataracts in uveitis and the possible role of the lens as a source of autoantigens in recurrent uveitis.


Interference of 50 Hz electrical cortical potentials evoked by TV systems. Application of TV systems for generating patterned stimuli for the examination of the electrical cortical potentials has disadvantages caused by the frame frequency of 50 Hz of TV sets. Apart from a larger variability in latency times of the electrical potentials as compared to the results obtained by projector systems, a 50-Hz noise on the recordings mediated through the visual system may be seen. These disadvantages can be ameliorated by increasing the frame frequency of the TV set.


Rebound nystagmus: EOG analysis of a case with a floccular tumour. Eye movements were recorded and quantitatively analysed in a patient with a tumour initially involving the cerebellar flocculus. Ocular motor abnormalities included (1) impaired smooth pursuit, (2) impaired cancellation of the vestibulo-ocular reflex when fixating an object rotating with the head, and (3) gaze paretic and rebound nystagmus. Comparable findings have been reported in monkeys with experimental floccular lesions. The rebound nystagmus (but not the other ocular motor abnormalities) disappeared when the tumour appeared to invade the brain stem in the region near the vestibular nuclei. This finding suggests that the floccular lesion unmasked a bias which created rebound nystagmus and that the bias probably arose in the vestibular nuclei.


Use of electroacoustic localisation in the management of intraocular foreign bodies. A new model of the electroacoustic discriminator and localiser has been put into production, and this paper reports on the preproduction model during its trial period in the management of patients with intraocular foreign bodies. Its particular advantage in localisation at the time of surgery and the procedure for using it are described. The visual results following surgical extraction of 17 cases of magnetic foreign bodies in the posterior segment are outlined.


Gentamicin penetration and decay in the human aqueous. The penetration of gentamicin into human aqueous was measured after intensive drops or subconjunctival injection of the antibiotic. The drop regimen proved ineffective in producing a therapeutically effective level. After a single 40 mg subconjunctival injection an effective concentration was achieved in 2 hours and maintained for 24 hours. The significance of these findings is discussed with respect to therapeutic implications.


Changes in body composition after thermal injury in the rat. 1. The effects on body composition, measured by direct techniques, of a controlled 25% body-surface-area thermal injury have been studied in two groups of forty male Wistar rats. 2. The extent of weight loss in the animals was directly related to their energy deficit resulting from a combination of injury, food intake and rat of wound healing. 3. Body fat proved the most labile source of tissue energy, decreasing to a minimum of approximately 30 g/kg body-weight. 4. Relationships between water and fat, and water and protein seen in control animals were not significantly different in the traumatized group.


The effect of pectin on the structure and function of the rat small intestine. 1. The effect of pectin on the structure and function of the rat small intestine was compared with that of a standard pellet diet and of a fibre-free basal diet. 2. The length and wet weight of the small bowel was significantly greater inpect in-fed rats than in either pellet- or basal-diet-fed rats. 3. Histological measurements of longitudinal sections from the small bowel showed a significantly greater crypt depth and muscle layer thickness in the mid-jejunum and ileum of the pectin fed rats. Villous height showed less variation. 4. The specific activity of alkaline phosphatase (EC 3.1.3.1) and leucyl-beta-naphthylamidase (EC 3.4.11.1) in mucosal scrapings was significantly lower in the upper jejunum of pectin-fed rats compared with either of the other dietary groups. The differences were not so marked in mid-jejunum or ileum. 5. Glucose absorption measured in vivo from jejunal and ileal loops was similar in all three dietary groups. 6. With two minor exceptions there were no significant differences in any of these measurements between the pellet- and basal-diet-fed rats. 7. These findings could be explained by increased epithelial cell turnover caused by pectin. The possible mechanisms of this are discussed. 8. The effect of pectin on the human small bowel requires study before it can be widely prescribed in man.


WHO sponsored collaborative studies on nutritional anaemia in India. The effects of ascorbic acid and protein supplementation on the response of pregnant women to iron, pteroylglutamic acid and cyanocobalamin therapy. 1. A study was conducted in two centres in southern and northern India of the effects of the addition of ascorbic acid and protein supplements to iron, pteroyglutamic acid and cyanocobalamin, in the prophylaxis and treatment of anaemia of pregnancy. 2. A dose of 500 mg ascorbic acid/d had no beneficial effect. Women who received 15 g calcium caseinate/d showed a superior haematological response. The reasons for this are unknown, but are more likely attributable to an increased absorption of the supplemental iron than to the correction of a protein deficiency.


WHO sponsored collaborative studies on nutritional anaemia in India. The effect of parenteral iron administration in the control of anaemia of pregnancy. 1. The relative efficacy of oral and parenteral iron administration in the prophylaxis and treatment of Fe-deficiency anaemia of pregnancy has been studied. 2. Intravenous administration of Fe by total dose infusion of Fe dextran was not superior to oral Fe 120 mg/d, 6 d/week for 10-12 weeks. 3. Intramuscular Fe dextran, 100 mg twice per week for 10-12 weeks, produced a significantly greater rise in mean haemoglobin concentration than oral Fe therapy. 4. The superiority of intramuscular Fe as compared with intravenous Fe is probably related to the different handling of the Fe dextran by the reticulo-endothelial system. 5. In spite of the better response to intramuscular Fe dextran, it is not recommended for public health practice because of the risks associated with its use and the much higher cost of the preparation and its delivery.


Intake of copper, iron, manganese and zinc by healthy, exclusively-breast-fed infants during the first 3 months of life. 1. The calculated median daily trace element intakes /kg of exclusively-breast-fed infants at 1, 2 and 3 months of age respectively were: copper 0.075, 0.051 and 0.043 mg; iron 0.075, 0.055 and 0.048 mg; manganese 0.9, 0.6 and 0.5 microgram; zinc 0.420, 0.215 and 0.150 mg. The latter values for Cu, Fe, and Zn intakes were in good agreement with earlier results, whereas the intake of Mn was lower. The intakes of trace elements by breast-fed infants seemed to be below the recommended dietary allowances (Food and Nutrition Board, 1973; WHO Expert Committee on Trace Elements in Human Nutrition, 1973). 2. There seems to be no information on trace element concentrations of breast milk related to the energy content. Such values are therefore included for breast milk from Finnish women for the 1st 6 months of lactation.


Zinc deficiency in the West of Scotland? A dietary intake study. 1. The intake of zinc in the West of Scotland was determined by atomic absorption spectrometry, in ninety-six items of food which make up the local standard diet for 1 week. 2. The diet contained less Zn than the recommended daily allowance ((US) National Academy of Sciences, 1974). This finding either indicates the need for a revision of the suggested allowances or suggests that a change of diet is necessary. 3. The change could be made simply by the substitution of wholemeal flour for white flour. Other changes in diet were considered but they were unlikely to be acceptable. Even with changes the requirement of pregnant or lactating women would not be met. If the recommended allowances are valid these women must be deficient in Zn.


Effect of varying protein and energy intakes on nitrogen balance in Indian preschool children. 1. The effect of varying protein intake at two energy levels of 334 and 418 kJ/kg body-weight was studied in four preschool children belonging to the low socio-economic group. 2. Results indicated a curvilinear relationship between N intake and N rentention. From this relationship, the protein requirement of the children at adequate energy intake was calculated. 3. At adequate energy intake (418 kJ/kg body-weight) the protein requirement of the children was 1.33 g/kg. On decreasing the energy intake by 20% to 334 kJ/kg body-weight the protein requirement was found to be increased by 20% to 1.64 g/kg. 4. Based on this study, a safe level of protein intake for Indian preschool children subsisting on a diet based predominantly on vegetable proteins has been suggested.


Factors affecting the voluntary intake of food by sheep. 2. The role of distention and tactile input from compartments of the stomach. 1. Sheep equipped with rumen and abomasal cannulas were given ad lib. access to ground and pelleted lucerne (Medicago sativa) hay except for periods of up to 6 h immediately before experimental sessions in which food intake was measured while various stomach compartments were either distended or subjected to tactile stimulation from a probe. 2. Inserting a probe, consisting of two collapsed balloons tied onto the end of a polyethylene tube, into the reticulum depressed intake by 24% after 30 min of feeding (P less than 0.025). Compensatory feeding was observed during the 30 min period immediately following removal of the probes. There were no effects of having a probe in the abomascum. 3. Distension of the reticulum with 0-800 ml water in a balloon depressed intake by 0.2 g/ml after 30 min of feeding (P less than 0.05). Removing the balloons from the animals allowed them to make up the deficit in intake completely within 30 min. Distending the rumen by 800 ml had no effect on intake (P greater than 0.05). Distending the abomasum with up to 1000 ml water in a balloon depressed intake by 0.11 g/ml after 30 min of feeding with compensatory feeding being significant (P less than 0.05) but incomplete. 4. Combinations of reticular distension up to 800 ml and of abomasal distension up to 1200 ml did not have additive depressing effects on intake.


A comparison of the dye-binding and fluorodinitrobenzene methods for determining reactive lysine in leaf-protein concentrates. 1. Twenty-eight leaf-protein concentrate (LPC) samples, subjected to different thermal treatments, were produced from five curd batches. For these samples, the fluorodinitrobenzene (FDNB)-reactive lysine values gave closer agreement with dye-binding lysine (DBL) than with the dye-binding capacity (DBC). 2. No relationship was established between the dye-bound-after-propionylation (DBAP) and the histidine + arginine value. 3. Comparison of dye-bound-protein values with those for tungstic-acid-precipitated nitrogen x 6.25 for the LPC samples showed the heat-damaged samples to lie below the regression line for the other samples. 4. Reactive-lysine values by dye-binding and by FDNB methods correlated well with total lysine, but the slopes of the regression line indicated closer agreement for values for samples not damaged by heat. 5. The correlation coefficients between DBC and total basic amino acids, DBC and histidine + arginine + DBL, and DBC and histidine + arginine + FDNB-reactive lysine were similar. 6. There was no correlation between the lightness of colour of the LPC samples and the availability of lysine.


Intraruminal injection of urea and changes in secretion of parotid saliva in sheep. 1. Sheep were injected with varying doses of urea into the rumen and changes in the amount of saliva secreted from one parotid gland were studied. When the dose of urea was 0.1-0.2 g/kg, the secretion underwent no change. When the dose was 0.3 g/kg, the secretion was inhibited. When the dose was 0.4 or 0.5 g/kg, there was a marked inhibition in the secretion. 2. There was a close relationship between the ammonia level of the jugular blood and the inhibition of salivary secretion. When the ammonia level exceeded approximately 0.28 mmol/l, the secretion was inhibited abruptly. 3. Salivary secretion and rumen movement were inhibited when the blood ammonia level exceeded 0.28 mmol/l, after injection of ammonium acetate into the jugular vein. 4. Based on the results mentioned previously, the mechanism of inhibition on the secretion of parotid saliva is discussed in relation to the domestic ruminant in which urea had been injected into the rumen.


Estimation of heat production from heart-rate measurements in cattle. 1. Heat production and heart rate of seven steers were measured simultaneously using either a calorimetric chamber or head-cage. 2. The relationship between heat production and heart rate for each animal was best described by linear regression. 3. Differences between individual animals made separate 'calibration equations' necessary for each animal. 4. Accuracy of prediction of heat production from heart rate was better than +/- 10% in all instances. 5. It is concluded that frequent measurement of heart rate appears to offer a practical method for estimation of heat production of free-range animals.


Nitrogen digestion in sheep given poor-quality indigenous hill herbages. 1. In two experiments, the sites of digestion of non-ammonia nitrogen (NAN) and the amounts of urea N recycled to the rumen were measured in mature wether sheep given diets of indigenous hill herbage (Agrostis-Festuca and heather). 2. Duodenal and ileal flow values were obtained using 103Ru-phenanthroline and 51Cr-EDTA markers in animals prepared with simple (T-shaped) cannulas. Amounts of urea N recycled to the rumen were estimated from measurements of the transfer of plasma urea carbon into rumen bicarbonate and the production rate of rumen bicarbonate using 14C-labelled urea and bicarbonate respectively. 3. The flows of NAN at the duodenum and ileum were linearly related to the intake of herbage (P less than 0.001). There was a net gain of non-ammonia N anterior to the duodenum on both diets (at an intake of 460 g organic matter (OM)/d, 3.7 g NAN/d on Agrostis-Festuca and 3.3 g NAN/d on heather). 4. Net digestibility of NAN entering the small intestine was within a normal range on the Agrostis-Festuca (0.58 at 460 g OM intake) diet but low on the heather diet (0.43 at 460 g OM intake). 5. It was calculated that at 460 g OM intake only 0.9 and 1.1 g/d respectively of the duodenal NAN on the Agrostis-Festuca and heather diets could have been derived from urea-N recycled to the rumen. Thus 2.8 g and 2.2 g/d had to be accounted for as non-urea endogenous NAN.


Effect of sodium chloride deficiency on basal metabolism in broiler chickens. 1. Male broiler chickens were given a sodium chloride-deficient or NaCl-adequate diet from 7 to 21 d of age in Expt 1 and 28 to 56 d of age in Expt 2. 2. NaCl-deficient chickens had a markedly poorer growth and food conversion efficiency than those given the NaCl-adequate diet. 3. NaCl deficiency was associated with an increase in basal metabolic rate and increases in oxygen consumption, heat production and respiratory quotients were also noted. The glycogen content of chicken livers was also higher. 4. MEasurements of acid-base balance were found to be changed in NaCl-deficient chickens. Values for pH and bicarbonate content in blood plasma were lowered. 5. NaCl deficiency increased the packed cell volume and thyroxine level in blood plasma. Sodium and chloride contents in blood were lowered. 6. Results are discussed in relation to the decreased food conversion in NaCl-deficient chickens.


The mechanism of passage of endogenous urea through the rumen wall and the role of ureolytic epithelial bacteria in the urea flux. 1. The rumen urea concentration in gnotobiotic lambs lacking ureolytic bacteria was equal to that of blood. 2. Bacterial urease (EC 3.5.1.5) activity in sheep fed by intraruminal and intra-abomasal infusion was inversely related to rumen ammonia concentration. 3. A model is proposed for the facilitation and control of urea flux by wall-found ureolytic bacteria.


Foetal plasma magnesium levels during maternal hypo- or hypermagnesaemia in ewes. 1. The influence of maternal hypo- or hypermagnesaemia of foetal plasma magnesium levels was studied in pregnant ewes between the 120th and the 145th day of gestation using a permanent catheter inserted in utero into the left aorta of the foetus on the 115th day of gestation. 2. In seven ewes, carrying eleven foetuses, the injection of 1 alpha-hydroxycholecalciferol induced a hypomagnesaemia which lasted 72 h. This had no significant effect on foetal plasma Mg levels. 3. In five ewes, carrying six foetuses, hypermagnesaemia induced by a 2 h magnesium chloride infusion had no significant effect on foetal plasma Mg levels. 4. These results provide evidence that in sheep during the last 20 d of gestation the foetal regulation of plasma Mg is independent of the maternal plasma Mg levels.


The 3-methylhistidine content of human tissues. 1. The amount of 3-methylhistidine (3-MeH) has been measured in eighty-eight samples of tissue taken post-mortem from five adults. 2. The highest concentration (mumol/g fat-free dry weight) of 3-MeH was in skeletal muscle (3.31 +/- 0.05); intermediate values (2-3) were found in cardiac muscle and those tissues containing smooth muscle; and low values (less than 1) occurred in parenchymal tissues such as liver and kidney. 3. There was little variation between the mean 3-MeH content of striated muscles in different individuals, and no significant difference between the 3-MeH concentrations of striated muscles taken from six different sites. 4. The results suggest that it is justifiable to use values obtained from single muscles to calculate the rate of myofibrillar breakdown from urinary 3-MeH excretion.


Photochemical cycle of bacteriorhodopsin studied by resonance Raman spectroscopy. Individual species of the photochemical cycle of bacteriorhodopsin, a retinal-protein complex of Halobacteria, were studied in aqueous suspensions of the "purple membrane" at room temperature by resonance Raman (RR) spectroscopy with flow systems. Two pronounced deuterium shifts were found in the RR spectra of the all-trans complex BR-570 in H2O-D2O suspensions. The first is ascribed to C=NH+ (C=ND+) stretching vibrations of the protonated Schiff base which links retinal to opsin. The second is assigned tentatively to an "X-H" ("X-D") bending mode, where "X" is an atom which carries an exchangeable proton. A RR spectrum of the 13-cis-retinal complex "BR-548" could be deduced from spectra of the dark-adapted purple membrane. The RR spectrum of the M-412 intermediate was monitored in a double-beam pump-probe experiment. The main vibrational features of the intermediate M' in the reaction M-412 in equilibrium hv M' leads to delta BR-570 could be deduced from a photostationary mixture of M-412 and M'. Difference procedures were applied to obtain RR spectra of the L-550 intermediate and of two new long-lived species, R1'-590 and R2-550. From kinetic data it is suggested that T1'-590 links the proton-translocating cycle to the "13-cis" cycle of BR-548. The protonation and isomeric states of the different species are discussed in light of the new spectroscopic and kinetic data. It is found that conformational changes during the photochemical cycle play an important role.


Influence of terminal 3' phosphates or 2',3'-cyclic phosphates on the conformations of oligoriboadenylates, oligoribocytidylates, and the corresponding monomers. The circular dichroism spectra of chemically synthesized adenylate and cytidylate dinucleotides and trinucleotides bearing terminal 3' phosphates have been compared under a variety of conditions with the spectra obtained from the corresponding oligomers with 2',3'-terminal cyclic phosphate groups. Similar comparisons for the mononucleotides are also presented. Although the base stacking of an oligomer with a terminal cyclic phosphate might be expected to be greater than that of the corresponding oligomer with a 3' phosphate from charge repulsion considerations, the magnitudes of the Cotton effects in the former class are always considerably smaller than those in the latter class. This suggests a decreased stacking. The implications of these observations are discussed in light of the compelling crystallographic evidence that cytidine 2',3'-cyclic phosphate adopts an unusual sugar puckering and the syn conformation.


Inhibition of procollagen cell-free synthesis by amino-terminal extension peptides. Peptides prepared from the amino termini of pro alpha 1(I) and pro alpha 1(III) collagen chains inhibit the production of pro alpha 1(I) and pro alpha 2 by rat calvaria rna in a reticulocyte cell-free system. The synthesis of other proteins was not altered, suggesting a specific effect on collagen production. Various peptides from the helical region of the alpha 1(I) chain did not alter translation. These studies, taken together with earlier studies showing inhibition of collagen synthesis by cells in culture receiving the amino-terminal peptides, are consistent with a regulatory function in collagen synthesis for the amino-terminal peptides from procollagen.


Isotope ratios in photosynthetic oxygen. Axenic suspensions of the fresh water green alga Ankistrodesmus braunii were illuminated under aerobic conditions. The released gas mixture was introduced into the ion source of an isotope mass spectrometer, which recorded the 18O/16O ratio. The 18O content of the photosynthetic oxygen (approximately 0.199%) exceeded that of the cell water (approximately 0.197%) significantly.


Radiative and nonradiative transitions in subchloroplast particles highly enriched in P-700. Radiative and nonradiative processes were investigated in subchloroplast particles highly enriched in P-700 (1 P-700 to 10 chlorophyll molecules) according to the method of classical fluorescence and of photoacoustical spectroscopy. The envelope of fluorescence spectrum divided into three Gaussian bands and their quantum yields of fluorescence were calculated. Indpendently the quantum yield of fluorescence was determined from the spectral course of the photoacoustical signal. Finally, the estimate of the photochemical activity of P-700, based upon the measured fluorescence quantum yield and upon the measured nonradiative losses of excitation energy, was done.


Photooxidation of the cytochrome b-559 in the presence of various substituted 2-anilinothiophenes and of some other compounds, in Chlamydomonas reinhardtii. Five substituted 2-anilinothiophenes and two substituted carbonylcyanide-phenylhydrazones were comparatively studied with respect to their capacities for inducing photooxidation of the cytochrome b-559 in chloroplast fragments and in whole cells of Chlamydomonas reinhardtii (wild type and P-700-lacking mutant Fl 5). In addition, some other compounds: antimycin A, picric acid, tetraphenylboron and NH4Cl were also tested. Cytochrome b-559 photooxidations were clearly observed in the presence of 2-(3-chloro-4-trifluoromethyl)anilino-3,5-dinitrothiophene (ANT 2p), 2-(3,4,5-trichloro)anilino-3,5-dinitrothiophene (ANT 2s), 2-(4-chloro)anilino-3,5-dinitrothiophene and, with greater amplitudes, in the presence of carbonylcyanide-p-trifluoromethoxyphenylhydrazone and carbonylcyanide-m-chlorophenylhydrazone, both in whole cells and in chloroplast fragments. Picric acid, antimycin A and tetraphenylboron were also able to induce cytochrome b-559 photooxidation in chloroplast fragments, but not in whole cells. In the wild type, the highest photoinduced redox changes were 1.1 (carbonylcyanide-p-trifluoromethoxyphenylhydrazone, carbonylcyanide-m-chlorophenyl-hydrazone) and 0.6 (ANT 2p, ANT 2s) mumol of oxidized cytochrome b-559/1 mmol of chlorophyll, corresponding to 40% and 23% of the redox changes which could be induced chemically. All these cytochrome b-559 photooxidations, the greater part of which was inhibited by 3-(3,4-dichloropheny)-1,1-dimethylurea and occurred in the mutant Fl 5, appeared to be mainly Photosystem II-dependent reactions. But 3-(3,4-dichlorophenyl)-1,1-dimethylurea-insensitive Photosystem I-dependent photooxidations of cytochrome b-559 occurred also in the wild type. On the other hand, 2-(4-dimethylamine)-anilino-3,5-dinitrothiophene, 2-N-methyl-(3-chloro-4-trifluoromethyl)anilino-3,5-dinitrothiophene and NH4Cl did not induce any cytochrome b-559 photooxidation. These results were discussed taking in consideration the nature of the molecular substitutions of the various tested substances and their respective acceleration of the deactivation reactions of the water-splitting enzyme system Y of photosynthesis capacities which had been defined elsewhere by Renger (Renger, G. (1972) Biochim. Biophys. Acta 256, 428-439) for spinach chloroplasts. Like the acceleration of the deactivation reactions of the water-splitting enzyme system Y effect, the capacity for inducing the cytochrome b-559 photooxidation appeared dependent on the acidity of the NH group and on the number of halogenous substituents in the aromatic ring of the molecule. The greatest action towards cytochrome b-559 photooxidation was obtained with the most active acceleration of the deactivation reactions of the water-splitting enzyme system Y agents: carbonylcyanide-p-trifluoromethoxyphenylhydrazone, ANT 2p and ANT 2s.


Photochemically active pigment-protein complexes from the green photosynthetic bacterium Prosthecochloris aestuarii. Photochemically active pigment-protein complexes were prepared from a bacteriochlorophyll a containing membrane preparation of the green photosynthetic bacterium Prosthecochloris aestuarii. The preparations contained about 75 and 35 bacteriochlorophyll a molecules per reaction center and had molecular weights of 6 . 10(5) and 3.5 . 10(5), respectively. Some of the other properties of these preparations are described.


Isolation and characterization of a rubredoxin and two ferredoxins from Desulfovibrio africanus. Rubredoxin and two distinct ferredoxins have been purified from Desulfovibrio africanus. The rubredoxin has a molecular weight of 6000 while the ferredoxins appear to be dimers of identical subunits of approximately 6000 to 7000 molecular weight. Rubredoxin contains one iron atom, no acid-labile sulfide and four cysteine residues per molecule. Its absorbance ratio A278/A490 is 2.23 and its amino acid composition is characterized by the absence of leucine and a preponderance of acidic amino acids. The two ferredoxins, designated I and II, are readily separated on DEAE-cellulose. The amino acid compositions of ferredoxins I and II show them to be different protein species; the greater number of acidic amino acid residues in ferredoxin I than in ferredoxin II appears to account for separation based on electronic charge. Both ferredoxins contain four iron atoms, four acid-labile residues per molecule. Spectra of the two ferredoxins differ from those of ferredoxins of other Desulfovibrio species by exhibiting a pronounced absorption peak at 283 nm consistent with an unusual high content of aromatic residues. The A385/A283 absorbance ratio of ferredoxins I and II are 0.56 and 0.62, respectively. The N-terminal sequencing data of the two ferredoxins clearly indicate that ferredoxins I and II are different protein species. However, the two proteins exhibit a high degree of homology.


Photosynthetic carbon metabolism in Panicum milioides, a C3-C4 intermediate species: evidence for a limited C4 dicarboxylic acid pathway of photosynthesis. Panicum milioides, a naturally occurring species with C4-like Kranz leaf anatomy, is intermediate between C3 and C4 plants with respect to photo-respiration and the associated oxygen inhibition of photosynthesis. This paper presents direct evidence for a limited degree of C4 photosynthesis in this C3-C4 intermediate species based on: (a) the appearance of 24% of the total 14C fixed following 4 s photosynthesis in 14CO2-air by excised leaves in malate and aspartate and the complete transfer of label from the C4 acids to Calvin cycle intermediates within a 15 s chase in 12CO2-air; (b) pyruvate- or alanine-enhanced light-dependent CO2 fixation and pyruvate stimulation ote- or alanine-enhanced light-dependent CO2 fixation and pyruvate stimulation of oxaloacetate- or 3-phosphoglycerate-dependent O2 evolution by illuminated mesophyll protoplasts, but not bundle sheath strands; and (c) NAD-malic enzyme-dependent decarboxylation of C4 acids at the C-4 carboxyl position, C4 acid-dependent O2 evolution, and 14CO2 donation from (4-14C)C4 acids to Calvin cycle intermediates during photosynthesis by bundle sheath strands, but not mesophyll protoplasts. However, P. milloides differs from C4 plants in that the activity of the C4 cycle enzymes is only 15 to 30% of a C4 Panicum species and the Calvin cycle and phosphoenolpyruvate carboxylase are present in both cell types. From these and related studies (Rathnam, C.K.M. and Chollet, R. (1979) Arch. Biochem. Biophys. 193, 346-354; (1978) Biochem. Biophys. Res. Commun. 85, 801-808) we conclude that reduced photorespiration in P. milioides is due to a limited degree of NAD-malic enzyme-type C4 photosynthesis permitting an increase in pCO2 at the site of bundle sheath, but not mesophyll, ribulose-bisphosphate carboxylase-oxygenase.


Chlorophyll a fluorescence as a monitor of nanosecond reduction of the photooxidized primary donor P-680 Of photosystem II. 1. Changes in the fluorescence yield of aerobic Chlorella vulgaris have been measured in laser flashes of 15 ns, 30 ns and 350 ns half time. The kinetics after the first flash given after a 3 min dark period could be simulated on a computer using the hypothesis that the oxidized acceptor Q and primary donor P+ are fluorescence quenchers, and Q- is a weak quencher, and that the reduction time for P+ is 20-35 ns. 2. The P+ reduction time for at least an appreciable part of the reaction centers was found to be longer after the second and subsequent flashes. In the first 5 flashes an oscillation was observed. Under steady state conditions, with a pulse separation of 3 s, a reduction time for P+ of about 400 ns for all reaction centers gave the best correspondence between computed and experimental fluorescence kinetics.


Surface potential and reaction of the membrane-bound electron transfer components. II. Integrity of the chloroplast membrane and reaction of P-700. Electrostatic characteristics of the membrane in the vicinity of P-700 were estimated by analyzing the salt and detergent effects on its reaction rate with ionic reagents using the Gouy-Chapman diffuse double layer theory in various preparations of chloroplasts. Upon disruption of thylakoid membranes by sonic treatment or by treatment with digitonin, the reaction rate markedly increased, while the estimated surface charge density became smaller. It was concluded that the membrane surface which determines the reaction rate between P-700 and the ionic reagents changed as the disruption of thylakoid structure. The outer thylakoid surface had more negative charges than the inner one. Changes in the electrical potential profile across the thylakoid membrane during the illumination were also discussed from these results.


Quenching of fluorescence by triplet excited states in chloroplasts. The fluorescence quantum yield in spinach chloroplasts at room temperature has been studied utilizing a 0.5-4.0 mus duration dye laser flash of varying intensities as an excitation source. The yield (phi) and carotenoid triplet concentration were monitored both during and following the laser flash. The triplet concentration was monitored by transient absorption spectoscopy at 515 nm, while the yield phi following the laser was probed with a low intensity xenon flash. The fluorescence is quenched by factors of up to 10-12, depending on the intensity of the flash and the time interval following the onset of the flash. This quenching is attributed to a quencher Q whose concentration is denoted by Q. The relative instantaneous concentration of Q was calculated from phi utilizing the Stern-Volmer equation, and its buildup and decay kinetics were compared to those of carotenoid triplets. At high flash intensities (greater than 10(16) photon . cm-2) the decay kinetics of Q are slower than those of the carotenoid triplets, while at lower flash intensities they are similar. Q is sensitive to oxygen and it is proposed that Q, at the higher intensities, is a trapped chlorophyll triplet. This hypothesis accounts well for the continuing rise of the carotenoid triplet concentration for 1-2 mus after the cessation of the laser pulse by a slow detrapping mechanism, and the subsequent capture of the triplet energy by carotenoid molecules. At the maximum laser intensities, the carotenoid triplet concentration is about one per 100 chlorophyll molecules. The maximum chlorophyll ion concentration generated by the laser pulses was estimated to be below 0.8 ions/100 chlorophyll molecules. None of the observations described here were altered when a picosecond pulse laser train was substituted for the microsecond pulse. A simple kinetic model describing the generation of singlets and triplets (by intersystem crossing), and their subsequent interaction leading to fluorescence quenching, accounts well for the observations. The two coupled differential equations describing the time dependent evolution of singlet and triplet excited states are solved numerically. Using a single-triplet bimolecular rate constant of gammast = 10(-8) cm3 . s-1, the following observations can be accounted for: (1) the rapid initial drop in phi and its subsequent levelling off with increasing time during the laser pulse, (2) the buildup of the triplets during the pulse, and (3) the integrated yield of triplets per pulse as a function of the energy of the flash.