Vitamin Bi Research Articles

CHEMICAL COMPOSITION AND SENSORY EVALUATION OF COOKIES PRODUCED FROM RED VARIETY OF SORGHUM, GROUNDNUT AND SOYBEAN FLOURS

Cookies are flat dry sweet biscuits eaten on a large scale across all age categories in both low and high income nationswhere non-communicable diseases are on the increase. The experimental study was carried out to evaluate the sensoryproperties, chemical composition (proximate), minerals (Ca, Mg, P and Zn), vitamins (pro-vitamin A,BI, B2 and E), antinutrients(tannin, phytate, saponin) of four formulated composite flour cookies. They were produced from sorghum flour(SF), groundnut flour (GF), soybean flour (SOF) and wheat flour (WF) and determined using standard procedures.Three ofthe formulated composite flour cookies contained no wheat flour and were blended using the following ratio:(A=70%SF:20%SOF:10%GF, B=60%SF:20%SOF:20%GF and C=50%SF:30%SOF:20%GF), respectively. The fourthsample (control) had 100% wheat flour and 15 panelists evaluated the organoleptic properties of the cookies. The proximatecomposition showed that the dry matter of the cookies ranged from 94.74% (D)-96.58% (A), moisture content ranged from3.42% (A)-5.26% (D), ash content ranged from 2.27% (D)-3.73% (C), crude fiber ranged from 2.55% (D)-4.0% (C), crudeprotein ranged from 10.87% (D)-26.92% (B), fat content ranged from 12.25% (D)-40.43% (B), carbohydrate contentsranged from 20.98% (B)-66.80% (D) and the energy values ranged from 1759.49kjoules (D)-2321.87kjoules (B). Mineralcompositions are as follows: calcium=10.40mg/100g (C)-15.20mg/100g (A), magnesium=5.30mg/100g (A,C)-7.20MG/100G (B), phosphorus=31.00mg/100g (D)-40.0mg/100g (C) and zinc=2.00mg/100g (A)-5.15MG/100G (D). Thecookies had significant amounts of pro-vitamin A (5.56ug/100g (D)-8.21ug/100g (B), vitamin E (2.43mg/100g (D)-4.76mg/100g (B), low vitamin BI and B2 (0.21mg/100g (A)-0.44mg/100g (B) and 0.14mg/100g (D)-0.38mg/100g (B),respectively. Organoleptically, all the experimental samples were similarly accepted with the control, although sample Bwas more acceptable.The study showed that enriching sorghum flour with soybean and groundnut flours in cookiesproduction improved their nutritional value and could be used to reduce the dependency on wheat flour.

Oral Prednisolone Treatment of Sudden Sensory Neural Hearing Loss: 16 A Three Year Retrospective Analysis

Sudden Sensory Neural Hearing Loss (SSNHL) is a serious medical condition and requires prompt medical attention. The study was done to estimate the effect of different protocols of oral Prednisolone plus high dose vitamin B-complex and vitamin BI, 132. Be in patients with unilateral SSNHL who have failed to respond to treatment. A retrospective study was done from January 2015 to January 2018 at the outdoor patient department of Holy Family Red Crescent Medical College Hospital, Dhaka among 75 randomly selected patients with a mean age of 46.32 years (range 25-69 years). with the preselected criteria. Each of the patient received one of the four standard oral Prednisolone dosing protocols along with high dose of vitamin B-complex and BI, 132, Be orally 20mg four times for a total dose of 80mg daily for one week, Group A, n=18; orally 20 mg three times, for a total dose of 60mg daily for one week Group B, n=18; orally 20mg two times for a total dose of 40mg daily for one week Group C, n=18; orally 10mg three times for a total dose of 30mg daily for one week. Group a n=18. All the doses were then tapered for next 5 days. Patient characteristics and pharmacological effects were compared among the 4 groups. The mean age, average duration of symptoms from onset to treatment, and degree of hearing loss were analyzed by means oft-test Treatment effects were analyzed by means of Chi-square test. P<0.05 was considered significant. Improvement of hearing was assessed by pure tone audiogram. The total effective rate was 88.89% 83.33%, 77.78% 66.67% for each treatment protocol, respectively, with no significant statistical difference between them (p00.05). The results suggest that a total dose of 80 mg is the most appropriate protocol. Prednisolone significantly improves the prognosis of SSNHL. Further multicenter studies are needed to determine the more standard treatment protocol.

티아민 보충으로 치료한 감각신경성 난청 1예

Wernicke encephalopathy is a severe neurological disorder caused by thiamine (vitamin Bi) deficiency. This disease occurs mostly in alcoholics due to malnutrition or malabsorption of vitamin B1 but also occurs in hyperemesis gravidarum, carcinoma, anorexia nervosa. Auditory neuropathy is characterized by abnormal auditory brainstem and preserved cochlear outer hair cell function. This is a case of Auditory neuropathy caused by thiamine deficiency. Brain MRI scan showed typical Wernicke encephalopathy finding. To evaluate hearing impairment, Pure tone audiogram, Speech audiogram, Otoacoustic emision and Auditory brainstem evoked response were measured and the result were compatible with auditory neuropathy. After thiamine replacement therapy, patient’s hearing imparment and serial speech recognition score showed improvement. From our study, we can assume that thiamine deficiency cause selective destruction of inner ear cell, this will eventually helps us to reveal pathophysi- olology of auditory neuropathy. (J Clinical Otolaryngol 2013;24:225–232)

Serum T3 and T4 Concentrations in Lambs with Nutritional Myodegeneration

Background: Selenium (Se) deficiency is an important etiological factor in Nutritional Myodegeneration Disease (NMD) of lambs, and Se is required for synthesis of thyroid hormones. Hypothesis: That serum T4 and T3 concentrations in lambs with NMD will be abnormal. Animals: Ten healthy lambs and 15 lambs with NMD were included in the study. Methods: Serum thyroid hormone concentrations were measured by chemiluminescence assay in samples collected from control and NMD lambs before and after treatment with a preparation containing sodium selenite, vitamin E, and vitamin Bi, which was administered subcutaneously to lambs with NMD twice, with a 2‐week interval. Results: Before treatment, serum concentrations of fT3 and TT3 in lambs with NMD were lower than those of control group (P < .001), while serum concentrations of fT4 and TT4 in lambs with NMD were significantly higher than those of control group (P < .001, P < .01, respectively). Similarly, serum creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) values in lambs with NMD were significantly higher compared with those of control (P < .001, P < .001, P < .001, P < .01, and P < .05, respectively) before treatment. However, serum concentrations of Se and α‐tocopherol in lambs with NMD were significantly lower compared with those of control (P < .001). After treatment (at day 30), none of the variables were significantly different between control and NMD lambs (P > .05). Conclusions and Clinical Importance: Nutritional myodegeneration in lambs is associated with abnormalities in serum thyroid concentrations. Abnormalities in serum thyroid concentrations can result from selenium deficiency in NMD lambs. Serum thyroid concentrations together with serum CK, LDH, AST, ALT, and ALP values can be considered additional tools in diagnosis and prognosis of NMD in lambs.

STUDY OF POSSIBLE USING 0F Streptomyces baamensis sin-l AS A NATURAL sounce 0F VITAMIN 3,2

Streptomyces baarnensis strain SW‘lwas the most efficient strain in vitamin 2-; reduction. The effects of different concentrations of oatmeal extract. some e‘- ':nmenta| factors i.e. incubation period, initial pH, temperature and shaking rate : ‘r‘erent levels were studied to obtain the maximum yield of vitamin Bu:- production re 'esults of the present study revealed that the maximum yield of vitamin Bi :'::..ction by Streptomyces baarnensis strain SW1was reached under submerged :. t..re conditions in modified fermentation medium containing 15 g L“ of the most table raw material (oatmeal extract) with initial pH value 7’ and temperature so at 32 ”C after 6 days on a rotary shaker at 200 rpm. being 8. 08pg ml.The .T‘ty of S. baarnensis SW1 dried mycelium as natural source of vitamin 012 was szsdied , the obtained results in vivo revealed that vitamin Beg derived from the dried vcelium is available .

後期高齢入所者における高齢者用栄養素補充飲料による栄養状態の改善効果

A liquid nutrient mixture especially rich in vitamin B1 was given for 8 weeks to 10 nursing home residents with poor nutritional status. The intake of trace minerals (zinc and copper) and water-soluble vitamins (B1 and B2) by these subjects had been much less than the RDA levels, although the energy intake was relatively adequate. Three of the 10 subjects showed hypoalbuminemia (serum albumin less than 3.5mg/dl), and six showed a low serum vitamin B1 level (less than 28ng/ml).The administration of the supplement did not affect the intake of the diet, but provided an increased intake of various nutrients, especially the water-soluble vitamins. The serum vitamin Bi level was increased to the standard level in all the 10 subjects after 4 weeks of administration. The three subjects with hypoalbuminemia showed an increased serum albumin concentration after 8 weeks. A body weight gain was also observed up to 8 weeks which disappeared when the administration was stopped. The administration of a supplement to provide energy, protein and water-soluble vitamins may be useful for improving the condition of elderly people with poor nutritional status.

Structural Basis for Flip-Flop Action of Thiamin Pyrophosphate-dependent Enzymes Revealed by Human Pyruvate Dehydrogenase

The derivative of vitamin B1, thiamin pyrophosphate, is a cofactor of enzymes performing catalysis in pathways of energy production. In alpha2beta2-heterotetrameric human pyruvate dehydrogenase, this cofactor is used to cleave the Calpha-C(=O) bond of pyruvate followed by reductive acetyl transfer to lipoyl-dihydrolipoamide acetyltransferase. The dynamic nonequivalence of two, otherwise chemically equivalent, catalytic sites has not yet been understood. To understand the mechanism of action of this enzyme, we determined the crystal structure of the holo-form of human pyruvate dehydrogenase at 1.95-A resolution. We propose a model for the flip-flop action of this enzyme through a concerted approximately 2-A shuttle-like motion of its heterodimers. Similarity of thiamin pyrophosphate binding in human pyruvate dehydrogenase with functionally related enzymes suggests that this newly defined shuttle-like motion of domains is common to the family of thiamin pyrophosphate-dependent enzymes.

Certification of Nutrients in Standard Reference Material 1846: Infant Formula

In 1996, the National Institute of Standards and Technology (NIST) released Standard Reference Material 1846 (Infant Formula), which can be used as a control material for assigning values to in-house control materials and for validating analytical methods for measurement of proximates, vitamins, and minerals in infant formula and similar matrixes. The SRM was manufactured by preparing a spray-dried formula base containing fat, protein, carbohydrates, and minerals and then combining that formula base with a dry-blend vitamin premix that supplied the vitamins. The Certificate of Analysis for SRM 1846 provides assigned values for concentrations of proximates (fat, protein, etc.), vitamins, and minerals for which product labeling is required by the Infant Formula Act of 1980 and by the Nutrition Labeling and Education Act of 1990. These assigned values were based on agreement of measurements by NIST and/or collaborating laboratories. Certified values are provided for vitamins A (trans), E, C, B2, and B6 and niacin. Noncertified values are provided for solids, ash, fat, nitrogen, protein, carbohydrate, calories, vitamin D, delta-tocopherol, gamma-tocopherol, vitamin B1, vitamin B12, folic acid, pantothenic acid, biotin, choline, inositol, calcium, phosphorus, magnesium, iron, zinc, copper, sodium, potassium, and chloride. Information values are provided for iodine, manganese, selenium, and vitamin K.

Epileptic Manifestations and Vitamin B<sub>1</sub>Deficiency

Sixteen of 50 consecutive neurological patients with a diagnosis of thiamine deficiency showed epileptic (10) or epileptiform (6) manifestations. A survey of the literature revealed only few reports on a possible relationship between epilepsy and thiamine deficiency. It appears that thiamine deficiency may provoke epileptic phenomena in those patients who have subclinical predisposition for seizures. The presence of irritative activity on electroencephalographic recordings in the patients may be a consequence of a vitamin B1 deficiency state. The possible pathophysiological mechanisms by which thiamine deficiency may contribute to seizure activity of the brain are discussed.

Sensitive membrane electrodes for the determination of vitamin B1 and vitamin B6

The ion-selective membrane electrode technique has become a satisfactory tool for pharmaceutical analysis, although no pharmacopoeia has so far introduced their use for assays. Recent developments in pharmaceutical analysis with membrane electrodes [l-5] enable the activities of various drugs to be measured directly and selectively, and in most cases, without prior separation of the tested drug from the formulation matrix. Ion-selective membrane electrodes sensitive to vitamin Bi and vitamin B6 based on ionassociation extraction systems were first reported by Ishibashi et al. [6, 71. Nitrobenzene and 1,Zdichloroethane were found to be adequate membrane solvents for the respective ion-association complexes with tetraphenylborate and dipicrylamine. Picrolonate [8] and tetra (m-methyl-phenyl) borate [9] were also investigated as site carriers for vitamin electrodes. Hassan et al. [lo] applied the desulphurization procedures using solid potassium hydroxide and alkali plumbite solution to determine vitamin Bi, while Segopaul and Rechnitz [ll] proposed for the same purpose a potentiometric method based on measuring the initial rate of carbon dioxide formation from a reaction sequence involving the recombination of thiamine pyrophosphate using pyruvate decarboxylase apoenzyme with the holoenzyme. Many other recent analytical methods based on high-performance liquid chromatography (HPLC) [12-151, spectrometry [16-181, etc. have been developed for vitamin Bi and B6 assay in pharmaceuticals and clinical samples. The new membrane electrodes, sensitive to vitamin Bi and vitamin B6 proposed in this paper, were successfully applied for assaying the respective vitamins in tablet and injectable solutions by standard addition method.

Thermal quenching of the fluorescence of thiamine solutions

The investigations carried out in [1-5] of the luminescence properties of solutions of derivatives of thiamine (T) (vitamin BI) made it possible to determine the nature of the lower excited states of its chromophores and the paths of intramolecular energy transfer. It was established that the fluorescence of thiamine in alcoholic solutions is caused by the emission of the pyrimidine (P) chromophore, while the phosphorescence is caused by the emission of the thiazole (T3) chromophore of the vitamin molecule. In this case, the lowest excited singlet and triplet states are states of the S~Z, 7" and T~,~* types.

Peripheral nerve conduction function, vitamin bi serum level and visual evoked potential in chronic alcoholics

Here, we compared motor evoked potentials (MEP) in response to transcranial magnetic stimulation of the motor cortex and the H-reflex during voluntary and vibration-induced air-stepping movements in humans. Both the MEPs (in mm biceps femoris, rectus femoris and tibialis anterior) and H-reflex (in m soleus) were significantly smaller during vibration-induced cyclic leg movements at matched amplitudes of angular motion and muscle activity. These findings highlight differences between voluntary and non-voluntary activation of the spinal pattern generator circuitry in humans, presumably due to an extra facilitatory effect of voluntary control/triggering of stepping on spinal motoneurons and interneurons. The results support the idea of active engagement of supraspinal motor areas in developing central pattern generator-modulating therapies.

Neonatal intraventricular hemorrhage: Hypoglycorrhachia and its relationship to CSF lactate levels

1. Ek J, and Magnus EM: Folic acid levels in infancy, in Proceedings of Fourteenth International Congress of Pediatrics, Buenos Aires, Oct. 3-9, 1974, Buenos Aires, 1974, Editorial Medica Panamericana, p 49. 2. Hibbard ED, and Kenna AP: Plasma and erythrocyte folate levels in low-birth-weight infants, J PEDIATR 84:750, 1974. 3. Landon MJ, and Oxley A: Relation between maternal and infant blood folate activities, Arch Dis Childh 46:810, 1971. 4. Morgan SK: Newborns and Folic acid, J Sci Med Assoc 64:499, 1968. 5. Brenner WE, Edelman DA, and Hendricks CH: A standard of fetal growth for the United States of America, Am J Obstet Gynecol 126:555, 1976. 6. Sterky G: Swedish standard curves for intra-uterine growth, Pediatrics 46:7, 1970. 7. Magnus E: Folate studies, Scand J Haematol Suppl No. 24, 1975. 8. Magnus E: Folate concentrations in top, middle and bottom layer of packed red cells in vitamin BI~ deficiency. Relation to treatment, Scand J Haematol (in press). 9. Ek J, and Magnus EM: Plasma and red blood cell folate in breasted infants, Acta Paediatr Scand 68:239, 1979. 10. Dixon WJ: BMDP. Biomedical Computer Programs, Berkeley, Calif., 1977, University of California Press. tl . Ek J, and Magnus E: Plasma and red blood cell folate during normal pregnancies, Acta Obstet Gynecol Scand (submitted). 12. Ek J: Plasma and red cell folate values in formula-fed term infants during the first year of life (in preparation). 13. Hoffbrand AV, Newcombe BFA, and Mollin DL: Method of assay of red cell folate activity and the value of the assay as a test for folate deficiency, J Clin Pathol 19:17, 1966. 14. Kamen BA, and Caston JD: Purification of folate binding factor in normal umbilical cord serum, Proc Natl Acad Sci USA 72:4261, 1975. 15. Ainley N J: Megaloblastic anemia of pregnancy and the puerperium, J Obstet Gynaecot Br Emp 68:254, 1961. 16. Strelling MK, Blackledge GD, Goodall HB, and Walker CHM: Megaloblastic anemia and whole-blood folate levels in premature infants, Lancet 1:898, 1966. 17. Zuelzer WW and Ogden FN: Megaloblastic anemia in infancy, Am J Dis Child 71:211, 1946.

Pharmacokinetics of gentamicin during exchange transfusions in neonates

6. Steinherz P, Rosen G, Ghavimi F, Wollner N, Wang Y, and Miller D: Improved leukocyte counts after chemotherapy with lithium carbonate, Proc Am Soc Clin Onc 20:439, 1979. 7. Ghavimi F, Exelby P, Jereb B, Scott BF, Lieberman PH, and Kosloff C: The multidisciplinary treatment for advanced stages of embryonal rhabdomyosarcoma in children, JNCI (in press). 8. Snedecor GW, and Cochran WG: Statistical methods, Ames, Iowa, 1976, Iowa State University Press, p 128. 9. Tisman, G, Herbert V, and Rosenblatt S: Evidence that lithium induces human granulocyte proliferation: Elevated Serum vitamin BI~ binding capacity in vivo and granulocyte colony proliferation in vitro, Br J Haematol 24:767, 1973. 10. MaUoy NL, Zauber NP, and Chervenick PA: The effect of lithium on blood and marrow neutrophils, Blood 52:228, 1978. 11. Rothstein G, Clarkson DR, Larsen W, Grosset BI, and Athens JW: Effect of lithium on neutrophil mass and production, N Engl J Med 298:178, 1978. 12. Rossof AH, and Coltman CA: The effect of lithium carbonate on the granulocyte phagocytic index, Experimentia 32:238, 1976. 13. Shenkman L, Borkowsky W, Holzman RS, and Shopsin B: Enhancement of lymphocyte and macrophage function in vitro by lithium carbonate, Clin Immunol Immunopathol 10:187, 1978. 14. Cohen MS, Zakhireh G, Metcalf JA, and Root RK: Granulocyte function during lithium treatment, Blood 53:913, 1979. 15. Harker WG, Rothstein G, Clarkson D, Athens JW, and Macfarlane JL: Enhancement of colony-stimulating activity production by lithium, Blood 49:263, 1977. 16. Morley DC, and Galbraith PR: Effect of lithium on granulopoiesis in culture, Can Med Assoc J 118:288, 1978. 17. Tisman G: Lithium carbonate protection against druginduced leukopenia in lymphosarcoma patients, J Int Res Commun 2:1509, 1974. 18. Catone R, Kaufman J, Mittelman A, and Murphy GP: Attenuation of myelosuppression with lithium, N Engl J Med 297:452, I977. 19. Charron D, Barrett AJ, Faille A, Alby N, Schmitt T, and Degos L: Lithium in myeloid leukemia, Lancet 1:1307, 1977. 20. Greco FA, and Brereton HD: Effect of lithium carbonate on the neutropenia caused by chemothearpy: A preliminary clinical trial, Oncology 34:153, 1977. 21. Lyman GH, Williams CG, and Preston D: A prospective randomized study of the effect of lithium carbonate on the granulocytopenia and incidence of infection associated with intensive chemotherapy and radiation therapy for undifferentiated small cell bronchogenic carcinoma, Blood 52:228, 1978. 22. Stein RS, Hanson G, Koethe S, and Hanson R: Lithiuminduced granulotosis, Ann Intern Meal 88:809, 1978. 23. Stein RS, Flexner JM, and Graber S: Lithium and granulocytopenia during induction therapy for acute myelogenous leukemia, Blood 52:277, 1978. 24. Tiefenbach A, Konja J, Potkonjak-Sesko M, and Mestrovic B: Effect of Li~CO3 on leukopenia in children during treatment of acute leukemia, Lijec Vjesm 99:163, 1977.

Determination of Vitamin Bi in Pharmaceutical Preparations Using a Lead Ion Selective Electrode and Atomic Absorption Spectroscopy

Simple, rapid, and accurate methods have been developed for determining vitamin B1 in pharmaceutical preparations without prior separation of the vitamin. The methods are based on the desulfurization reaction with potassium plumbite and measurement of the unreacted lead(II) ions at 217 nm using atomic absorption spectroscopy (AAS), or by titration with EDTA at pH 4.5 with the lead ion selective electrode and Gran's plot. The results compare favorably with those obtained using the USP fluorometric method. Recoveries of pure vitamin B1 averaged 99.1%, with a standard deviation of 0.8%, and 99.0%, with a standard deviation of 0.7%, for the AAS and ion selective electrode procedures, respectively.

Chemiluminescence method for the quantitative determination of vitamin B1 and its phosphate esters in pharmaceutical and biological samples

A large number of methods have been proposed for the quantitative determination of vitamin BI (thiamine): gravimetric [i], fluorometric [2, 3], titrimetric [3], spectrophotometric [4], polarographic [3, 5], and several others [6, 7]. The common deficiency of these methods (apart from fluorometry) is their inadequate specificity. The determination of vitamin B: and its phosphate esters by these methods suffers from interference by various organic and inorganic substances, particularly the products of hydrolysis (thiazole and aminopyrimidine derivatives) and oxidation (thiochrome and thiamine disulfide) of the original substances [8]. This necessitates prolonged and difficult operations for the preliminary separation of thiamine from the impurities by, for example, extraction, adsorption, and chromatographic methods [2, 3, 9-11]. Furthermore the bound forms of natural vitamin BI, such as cocarboxylase, require enzymolysis to thiamine before fluorometric determination [3]. The accuracy of the extant methods for determining vitamin BI varies from 0.08 [6] to 20% [2], depending on the nature of the test sample. The search for rapid, simple, and reliable methods continues to be urgent.

Tuberculous peritonitis and laparotomy.

Tuberculous Peritonitis and Laparotomy M. F. Dixon, M.B., and J. A. Davies, M.R.C.P. 674 Hospital Advisory Service G. W. Taylor, M.R.C.G.P 674 Rh Immunization in Ruptured Tubal Pregnancy R. D. Barr, M.R.C.P 674 Thiocyanate Metabolism in Human Vitamin Bi Deficiency A. G. Freeman, F.R.C.P 675 Children of Anaesthetists R. Wyatt, M.B., D.A. and A. M. Wilson, F.F.A. R.C.S. 675 Contact Sensitivity to Toothpaste L. G. Millard, M.R.C.P 676 Constraints on Consultants R. D. Scott, M.R.C.P 676 Tumoral Calcinosis in Britian K. S. Vasudev, M.B., and others 676 Drop Attacks in Women -N. Capener, F.R.C.S.; T. E. Lear, M.R.C.PSYCH. 676 Cell-mediated Immunity in Thyroid Disease N. R. Farid and others 677 Teachers and Patients H. H. 0. Wolff, F.R.C.P 677 Serum Alkaline Phosphatase and Rickets in Urban Schoolchildren A. S. Truswell, M.D 677 Lignocaine in Donor Blood J. A. G. da Costa, M.R.C.P., and others ...... 677 Congenital Hemihypertrophy A. W. Johnston, M.D 678 Day Hospitals and Day Centres J. R. Wilkie, M.B 678 Diseases of Western Civilization Surgeon Captain T. L. Cleave, M.R.C.P.; W. M. Castleden, F.R.A.C.S 678 Viral Infection and Renal Transplant Rejection J. R. T. Gabriel, M.R.C.P., and others...... 679 Postherpetic Neuralgia J. M. S. Pearce, M.D 679 Tragic Dilemma J. Lowther, M.B 679 Oil Myelography D. J. Mitchell, F.F.R.R.C.S.I 680 Efficacy of Whooping-cough Vaccines G. W. J. Bousfield, M.D 680 Immunization against Influenza T. C. G. Smith, M.B 680 Short-term Service Abroad P. Rabindran, M.R.C.P 680 Role ofPacing after Myocardial Infarction Helen H. Tucker, M.B., and others ........ 680 Cranial Nerve Palsy in Tetanus R. P. Patel, M.B., and M. Sorokin 681 Mode of Action of Verapamil D. G. McDevitt, M.D., and R. G. Shanks, M.D 681 Gateshead Tuberculin Survey E. L. Feinmann, F.R.C.P., and others ...... 681 Pregnancy after Hysterotomy R. F. Heys, M.R.C.O.G 681 Loin Percussion in Acute Pyelonephritis B. T. B. Manners, M.R.C.P 682 Earnings of General Practitioners J. Winter, M.D.; E. Platts, M.R.C.O.G.......682 Management of the N.H.S. P. N. Dixon, D.P.H 682 London Pride? R. Buchan, F.R.C.S.ED 682

PHYTOPLANKTON GROWTH AND COMPOSITION IN SHIPBOARD CULTURES SUPPLIED WITH NITRATE, AMMONIUM, OR UREA AS THE NITROGEN SOURCE1

Coastal surface seawater off southern California was enriched with phosphate, silicate, vitamins B12, B1, and biotin, a chelated trace metal mixture, and with nitrogen as nitrate, ammonium, or urea, and the cultures were incubated on deck in daylight. Natural phytoplankton present in the seawater served as inoculum. Samples were taken every 6 hr, once the cultures were established. Diel periodicity was noted in diatom cell division, in nitrate and ammonium assimilation rate, in phosphate assimilation rate, and in photosynthetic rate measured at intervals under constant, artificial irradiance, but not in the rate of chlorophyll a synthesis. The chemical composition of the crops was influenced by the nitrogen source used for growth and by diel periodicity in assimilation rates. Most of the vitamin Bi content of the crop was synthesized by the organisms, only a small proportion being supplied initially from the medium. Some species known to require vitamins continued to grow after vitamin depletion from the medium, their requirements apparently satisfied by vitamins released by other species.

Studies on the Vitamin Bi Metabolism in blood, Perilymph, and Some Organs of the Guinea-pigs and the Middle Ear Muscles and Some Organs of the Rabbits after the Exposure to White Noise

Studies on the Vitamin Bi Metabolism in blood, Perilymph, and Some Organs of the Guinea-pigs and the Middle Ear Muscles and Some Organs of the Rabbits after the Exposure to White Noise

Histochemical Findings on the State of Nucleic Acids and Vitamin Bi in the Organ of Corti

Histochemical Findings on the State of Nucleic Acids and Vitamin Bi in the Organ of Corti