740
II, and III melanosomes were mainly observed in melanocytes. After incubation with 01% L-DOPA, however, most of the premature melanosomes were further melanised to stage IV in all samples. Melanocytes with many stage IV melanosomes after the DOPA reaction were easily identified under the electron
microscope. A pregnant
Japanese
woman, the mother of
a
boy
with
tyrosinase-negative OCA, sought genetic counselling and a prenatal diagnosis. There was no family history of OCA, thus the parents were regarded as heterozygous. DNA analysis revealed that the father had one of the two mutations of the tyrosinase gene known in Japan,2,3 whereas the gene mutation of mother was not identified (Dr Y. Tomita and Dr J. Matsunaga, Tohoku University). More than 25 alleles with a different tyrosinase gene mutation in OCA have been reported;2,3 thus it would be virtually impossible to use molecular analysis for prenatal diagnosis in the present case. Accordingly, we sampled skin from the upper trunk of the fetus guided by ultrasound. On conventional electronmicroscopy, the melanocytes contained stage I and II, but no stage III and IV melanosomes. Even after incubation with L-DOPA, only stage I and II melanosomes were observed and no further melanisation was detected, confirming the lack of tyrosinase activity in these fetal melanocytes. A prenatal diagnosis of tyrosinase-negative OCA was made. The parents requested a termination and skin biopsies of the abortus confirmed the diagnosis. The electronmicroscopic DOPA reaction test of a fetal skin biopsy specimen is safe and practical, and provides reliable information for making a prenatal diagnosis of tyrosinase negativeOCA in the second trimester.
Department of Dermatology. Keio University School of of Medicine, Tokyo 160; and Department of Obstetrics and Gynecology, Nagoya City University Medical School, Nagoya, Japan
HIROSHI SHIMIZU AKIRA ISHIKO ARATA KIKUCHI MASASHI AKIYAMA KAORU SUZUMORI TAKEJI NISHIKAWA
Witkop CJ Jr, Quevedo WC Jr, Fitzpatnck TB, King RA. Albinism. In Beaudet AL, Sly WS, Valle D, eds. The metabolic basis of inherited disease. 6th ed. New York: McGraw-Hill, 1989: 2905-47. 2. Tomita Y, Takeda A, Okmaga S, Tagami H, Shibahara S. Human oculocutaneous albinism caused by single base insertion in the tyrosinase gene. Biochem Biophys Res 1.
Commun 1989; 164: 990-96. 3. Takeda A, Tomita Y, Matsunaga J, Tagami H, Shibahara S. Molecular basis of tyrosinase-negative oculocutaneous albinism. J Biol Chem 1990; 265: 17792-97 4. Eady RAJ, Gunner DB, Tidman MT, Nicolaides KH, Rodeck CH. Prenatal diagnosis of oculocutaneous albinism by electron microscopy of fetal skin J Invest Dermatol 1983; 80: 210-12. 5 Eady RAJ. Prenatal diagnosis of oculocutaneous albinism: implications for other hereditary disorders of pigmentation. Semin Dermatol 1984; 3: 241-46 6. Mishima Y. Electron microscopic cytochemistry of melanosomes and mitochondria. J Histochem Cytochem 1964; 12: 784-90.
Percentage survival of rugose and smooth variants of V cholera 01. EI Tor Inaba C6706 (PERU[] = rugose, 0= smooth) and V cholera O1 EI Tor Inaba 2164-78 (US Gulf Coast, 0 =smooth) in presence of 0 5 mg/! free chlorine Initial inoculum was 10’ colony-forming units
virulent: in ligated rabbit ileal loops, rugose and smooth variants of V cholera 01 El Tor Inaba strain C6706 both elicited a mean fluid accumulation of 1 ’5 ml/cm. Our data suggest that the V cholera rugose phenotype represents a fully virulent survival form of the organism that can persist in the presence of free chlorine. The ability of V cholerae to assume this phenotype may limit the usefulness of chlorination in blocking endemic and epidemic spread of cholera.
Drinking Water Research Division, Risk Reduction Engineering Laboratory, U S. Environmental Protection Agency, Cincinnati, Ohio Division of
Geographic Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
EUGENE W. RICE CLIFFORD J. JOHNSON ROBERT M. CLARK KIM R. Fox DONALD J. REASONER MICHELE E. DUNNIGAN
PINAKI PANIGRAHI JUDITH A. JOHNSON J. GLENN MORRIS, Jr
1. Anon. Of cabbages and chlorine: cholera m Peru. Lancet 1992; 339: 20-21. 2. Shrivastav JB. Prevention and control of cholera. In: Barua D, Burrows Cholera. Philadelphia: W. B. Saunders, 1974. 3. White PB. The rugose variant of vibrios. J Pathol Bacteriol 1938, 46: 1-6.
W, eds
More about Latin Chlorine and survival of
"rugose"
Vibrio
cholerae SIR,-Chlorination of water has traditionally been promoted as effective means of blocking transmission of cholera.12 Smooth variants of Vibrio cholerae are, indeed, exquisitely sensitive to killing by chlorine (figure). However, in studies with strains of V cholerae an
01from the Peru epidemic, we have found that V cholerae is able to shift to a phenotype having a "wrinkled" or "rugose" colonial morphology that can survive chlorination. Disinfection of the rugose culture displayed a deviation from first-order kinetics, with persistence of a subpopulation of organisms after an initial two to three order of magnitude drop in count (figure). Viable V cholerae 01could still be recovered from rugose cultures even after exposure to 2-0 mg/1 free chlorine for 30 min. The rugose form of V cholerae was first described in 1938 by Bruce White, who recognised that it might serve as a survival form of the organism.3 As he reported, and as we have confirmed, rugose variants produce an intercellular matrix that promotes cell and which may shield the organism from adverse environmental conditions. In contrast to rough mutants, which have a modified lipopolysaccharide, rugose strains can revert back to the smooth morphology. Rugose strains also seem to be fully
aggregation
SIR,-Dr Franciotta of Pavia (July 4, p 64) deplores the expression "de novo" and points out that the extant Latin writings rarely contain it. But evidently the Romans said de novo so often that they shortened it a trifle, to "denuo", and wrote that. Surely a Roman, an eminently practical person, would not have found the slightly fuller spelling even a small thorn in his side, nor attempted to tamper with its familiar and well-understood use by ourselves? Morningside Drive, Edinburgh EH10 5NS, UK
120
J. M. FORRESTER
CORRECTIONS Ethnic Health Factfile.-In the noticeboard item on this factfile (July 18, 172), the reference should have read "The Ethnic Health Factfile. Available from Dr Ghada Karimi, Public Health Directorate, North West Thames Regional Health Authority, 40 Eastboume Terrace, London W2 3QR, UK. Cheques (£12.50 plus £1.50 p & p) should be made payable to North West p
Thames RHA.
Sustained haematological response to high-dose oralalfacalcidolin patients with myelodysplastic syndromes.-In this letter by Dr S. M. Kelsey and colleagues (Aug 1, p 316), the alfacalcidol was manufactured by Leo Laboratories.
II, and III melanosomes were mainly observed in melanocytes. After incubation with 01% L-DOPA, however, most of the premature melanosomes were further melanised to stage IV in all samples. Melanocytes with many stage IV melanosomes after the DOPA reaction were easily identified under the electron
microscope. A pregnant
Japanese
woman, the mother of
a
boy
with
tyrosinase-negative OCA, sought genetic counselling and a prenatal diagnosis. There was no family history of OCA, thus the parents were regarded as heterozygous. DNA analysis revealed that the father had one of the two mutations of the tyrosinase gene known in Japan,2,3 whereas the gene mutation of mother was not identified (Dr Y. Tomita and Dr J. Matsunaga, Tohoku University). More than 25 alleles with a different tyrosinase gene mutation in OCA have been reported;2,3 thus it would be virtually impossible to use molecular analysis for prenatal diagnosis in the present case. Accordingly, we sampled skin from the upper trunk of the fetus guided by ultrasound. On conventional electronmicroscopy, the melanocytes contained stage I and II, but no stage III and IV melanosomes. Even after incubation with L-DOPA, only stage I and II melanosomes were observed and no further melanisation was detected, confirming the lack of tyrosinase activity in these fetal melanocytes. A prenatal diagnosis of tyrosinase-negative OCA was made. The parents requested a termination and skin biopsies of the abortus confirmed the diagnosis. The electronmicroscopic DOPA reaction test of a fetal skin biopsy specimen is safe and practical, and provides reliable information for making a prenatal diagnosis of tyrosinase negativeOCA in the second trimester.
Department of Dermatology. Keio University School of of Medicine, Tokyo 160; and Department of Obstetrics and Gynecology, Nagoya City University Medical School, Nagoya, Japan
HIROSHI SHIMIZU AKIRA ISHIKO ARATA KIKUCHI MASASHI AKIYAMA KAORU SUZUMORI TAKEJI NISHIKAWA
Witkop CJ Jr, Quevedo WC Jr, Fitzpatnck TB, King RA. Albinism. In Beaudet AL, Sly WS, Valle D, eds. The metabolic basis of inherited disease. 6th ed. New York: McGraw-Hill, 1989: 2905-47. 2. Tomita Y, Takeda A, Okmaga S, Tagami H, Shibahara S. Human oculocutaneous albinism caused by single base insertion in the tyrosinase gene. Biochem Biophys Res 1.
Commun 1989; 164: 990-96. 3. Takeda A, Tomita Y, Matsunaga J, Tagami H, Shibahara S. Molecular basis of tyrosinase-negative oculocutaneous albinism. J Biol Chem 1990; 265: 17792-97 4. Eady RAJ, Gunner DB, Tidman MT, Nicolaides KH, Rodeck CH. Prenatal diagnosis of oculocutaneous albinism by electron microscopy of fetal skin J Invest Dermatol 1983; 80: 210-12. 5 Eady RAJ. Prenatal diagnosis of oculocutaneous albinism: implications for other hereditary disorders of pigmentation. Semin Dermatol 1984; 3: 241-46 6. Mishima Y. Electron microscopic cytochemistry of melanosomes and mitochondria. J Histochem Cytochem 1964; 12: 784-90.
Percentage survival of rugose and smooth variants of V cholera 01. EI Tor Inaba C6706 (PERU[] = rugose, 0= smooth) and V cholera O1 EI Tor Inaba 2164-78 (US Gulf Coast, 0 =smooth) in presence of 0 5 mg/! free chlorine Initial inoculum was 10’ colony-forming units
virulent: in ligated rabbit ileal loops, rugose and smooth variants of V cholera 01 El Tor Inaba strain C6706 both elicited a mean fluid accumulation of 1 ’5 ml/cm. Our data suggest that the V cholera rugose phenotype represents a fully virulent survival form of the organism that can persist in the presence of free chlorine. The ability of V cholerae to assume this phenotype may limit the usefulness of chlorination in blocking endemic and epidemic spread of cholera.
Drinking Water Research Division, Risk Reduction Engineering Laboratory, U S. Environmental Protection Agency, Cincinnati, Ohio Division of
Geographic Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
EUGENE W. RICE CLIFFORD J. JOHNSON ROBERT M. CLARK KIM R. Fox DONALD J. REASONER MICHELE E. DUNNIGAN
PINAKI PANIGRAHI JUDITH A. JOHNSON J. GLENN MORRIS, Jr
1. Anon. Of cabbages and chlorine: cholera m Peru. Lancet 1992; 339: 20-21. 2. Shrivastav JB. Prevention and control of cholera. In: Barua D, Burrows Cholera. Philadelphia: W. B. Saunders, 1974. 3. White PB. The rugose variant of vibrios. J Pathol Bacteriol 1938, 46: 1-6.
W, eds
More about Latin Chlorine and survival of
"rugose"
Vibrio
cholerae SIR,-Chlorination of water has traditionally been promoted as effective means of blocking transmission of cholera.12 Smooth variants of Vibrio cholerae are, indeed, exquisitely sensitive to killing by chlorine (figure). However, in studies with strains of V cholerae an
01from the Peru epidemic, we have found that V cholerae is able to shift to a phenotype having a "wrinkled" or "rugose" colonial morphology that can survive chlorination. Disinfection of the rugose culture displayed a deviation from first-order kinetics, with persistence of a subpopulation of organisms after an initial two to three order of magnitude drop in count (figure). Viable V cholerae 01could still be recovered from rugose cultures even after exposure to 2-0 mg/1 free chlorine for 30 min. The rugose form of V cholerae was first described in 1938 by Bruce White, who recognised that it might serve as a survival form of the organism.3 As he reported, and as we have confirmed, rugose variants produce an intercellular matrix that promotes cell and which may shield the organism from adverse environmental conditions. In contrast to rough mutants, which have a modified lipopolysaccharide, rugose strains can revert back to the smooth morphology. Rugose strains also seem to be fully
aggregation
SIR,-Dr Franciotta of Pavia (July 4, p 64) deplores the expression "de novo" and points out that the extant Latin writings rarely contain it. But evidently the Romans said de novo so often that they shortened it a trifle, to "denuo", and wrote that. Surely a Roman, an eminently practical person, would not have found the slightly fuller spelling even a small thorn in his side, nor attempted to tamper with its familiar and well-understood use by ourselves? Morningside Drive, Edinburgh EH10 5NS, UK
120
J. M. FORRESTER
CORRECTIONS Ethnic Health Factfile.-In the noticeboard item on this factfile (July 18, 172), the reference should have read "The Ethnic Health Factfile. Available from Dr Ghada Karimi, Public Health Directorate, North West Thames Regional Health Authority, 40 Eastboume Terrace, London W2 3QR, UK. Cheques (£12.50 plus £1.50 p & p) should be made payable to North West p
Thames RHA.
Sustained haematological response to high-dose oralalfacalcidolin patients with myelodysplastic syndromes.-In this letter by Dr S. M. Kelsey and colleagues (Aug 1, p 316), the alfacalcidol was manufactured by Leo Laboratories.
