A Dominant Suppressor of A and B

Abstract. A healthy blood donor was found to have no anti-A in his serum while his red cells typed as O. A maternal half-brother, whose father is not related, lacks anti-B. The pedigree shows that the effect is due to dominant suppression of normal A ¹ and B genes.     

Hepatitis A

Opinion statement Hepatitis A infection is typically transmitted by the fecal-oral route. Symptomatic infection is highly dependent on the age of the patient and usually follows a self-limited course. Once diagnosed, clinical and biochemical follow-up in the outpatient setting is generally appropriate. Treatment aims are to achieve symptomatic relief and to maintain adequate hydration and caloric intake. In patients with more severe disease, hospitalization may be needed to accomplish aggressive symptomatic therapy and close monitoring of liver function tests and mental status. Prompt evaluation for liver transplantation is appropriate in the rare case where fulminant liver failure develops. Given the absence of specific therapy for hepatitis A virus infection, the most important health care intervention is prevention of infection and/or transmission, which can be accomplished with the safe and effective use of immune globulin and commercially available vaccines.     

A case of hepatic tuberculosis: A tuberculoma

Tuberculosis (TB) is a common cause of morbidity and mortality worldwide and its eradication in the United States has stalled for the first time in decades. Isolated hepatic TB is an extremely uncommon form of extrapulmonary TB. Here we present a case of a tuberculous liver abscess and suggest that TB should be considered in patients who fail to respond to antibiotics and prompt diagnostic intervention.     

Hepatitis A

Known properties of hepatitis A virus are described in this article. HAV is a small non-enveloped picornavirus, grouped in the Enterovirus family, with unique biological features. The genome structure resembles that of other picornaviruses. Replication in cell cultures takes much longer than that of other picornaviruses and the yield is much lower. HAV is extremely heat- and pH-stable. Variants may induce cytopathogenic effects in vitro. Normally, however, the virus is non-cytopathogenic. The elimination of virus in vivo is assumed to be caused by action of HAV antigen specific CD8+ lymphocytes. In industrialized countries there is a declining incidence of reported hepatitis A cases, and the prevalence of antibodies in younger populations is low. Vaccines have been developed and in studies using human volunteers, good immunogenicity has been demonstrated. In the very near future a cell cultured derived, highly purified, inactivated vaccine will be available.     

Workshop A

We studied 108 heroindependent patients who had been “stabilized” on methadone, i.e., had no change in methadone dose for at least 2 weeks. With respect to their methadone detoxification regimen, 65 of the study patients preferred physician reg- ulation and 43 study patients preferred self-regulation. Half of each group was randomly assigned to self- or physician regulation. Twenty-five of the 108 patients reached abstinence following a regimen which lasted 22 weeks; there was no statistically significant difference in proportion of subjects reaching abstinence from any of the four study groups. We observed no differences in treatment retention, symptom severity, frequency of urines positive for morphine or quinine, or psycho- social functioning. Study subjects preferring self-regulation had statistically signif- icant increases in the number of dose raises. We conclude that there is no evidence to support the belief that physician regulation is superior to self-regulation in opioid detoxification regimens.     

A Study of Optimum Population Levels—A Progress Report

The purpose of this study is to explore different approaches and to develop a methodology that will allow a calculation of "optimum levels of population." The discussion is specialized to the United States, but the methodology should be broad enough to handle other countries, including less-developed countries. The study is based on economics, but with major inputs from the areas of technology, natural resources management, environmental effects, and demography.The general approach will be to develop an index for quality of life (IQL or Q-index) and to maximize this index as a function of level and distribution of population. The technique consists of a reshuffling of national income accounts so as to be able to go from the Gross National Product (GNP) to the index for quality of life, plus a careful discussion of what is and what is not to be included. The initial part of the study consists of a projection of the index for quality of life as population level increases and as population distribution changes, under the assumption of various technologies, particularly as these relate to the consumption of minerals, energy, and other natural resources. One would expect that as economic growth continues, an increasing fraction of expenditures would be for the diseconomics produced by population growth and economic growth.This study should be useful by providing a rational base for governmental policies regarding population, both in the United States and abroad. Another application of the study is to technology assessment, by measurement of the impact on economic well-being through the introduction of new technologies. Therefore, one can gauge the necessary and desirable investments in certain new technologies. In general, mathematical models resulting from this study can become useful diagnostic tools to analyze the consequences of various public and private policy decisions.     

Hypoglycin A: A Specific Inhibitor of Isovaleryl CoA Dehydrogenase

Evidence is presented for the specific in vivo and in vitro inhibition of isovaleryl CoA dehydrogenation by hypoglycin A and its derivative, alpha-ketomethylenecyclopropylpropionic acid. alpha-Methylbutyryl CoA dehydrogenation was also impaired, but the degree of inhibition was much lower. Isobutyryl CoA dehydrogenation was not inhibited. 4-Pentenoic acid inhibited none of these reactions. It is concluded that isovaleryl CoA is dehydrogenated by a specific enzyme, isovaleryl CoA dehydrogenase, contrary to previous assumptions that it is dehydrogenated by green acyl CoA dehydrogenase. The present concept agrees with our previous findings in isovaleric acidemia, a genetic disorder in which a specific defect of isovaleryl CoA dehydrogenase was observed. It was also demonstrated that isovaleric acidemia can be induced in experimental animals by the administration of hypoglycin A. Furthermore, some symptoms of "the vomiting sickness of Jamaica" appear to be due to isovaleric acid accumulation secondary to the ingestion of hypoglycin A.     

A distinct lineage of influenza A virus from bats

Influenza A virus reservoirs in animals have provided novel genetic elements leading to the emergence of global pandemics in humans. Most influenza A viruses circulate in waterfowl, but those that infect mammalian hosts are thought to pose the greatest risk for zoonotic spread to humans and the generation of pandemic or panzootic viruses. We have identified an influenza A virus from little yellow-shouldered bats captured at two locations in Guatemala. It is significantly divergent from known influenza A viruses. The HA of the bat virus was estimated to have diverged at roughly the same time as the known subtypes of HA and was designated as H17. The neuraminidase (NA) gene is highly divergent from all known influenza NAs, and the internal genes from the bat virus diverged from those of known influenza A viruses before the estimated divergence of the known influenza A internal gene lineages. Attempts to propagate this virus in cell cultures and chicken embryos were unsuccessful, suggesting distinct requirements compared with known influenza viruses. Despite its divergence from known influenza A viruses, the bat virus is compatible for genetic exchange with human influenza viruses in human cells, suggesting the potential capability for reassortment and contributions to new pandemic or panzootic influenza A viruses.     

A role for ultraviolet A in solar mutagenesis.

It is well established that exposure to solar UVB (290-320 nm) gives rise to mutations in oncogenes and tumor suppressor genes that initiate the molecular cascade toward skin cancer. Although UVA (320-400 nm) has also been implicated in multistage photocarcinogenesis, its potential contribution to sunlight mutagenesis remains poorly characterized. We have determined the DNA sequence specificity of mutations induced by UVB (lambda > 290 nm), and by UVA (lambda > 350 nm), at the adenine phosphoribosyltransferase locus of Chinese hamster ovary cells. This has been compared to results previously obtained for stimulated sunlight (lambda > or = 310 nm) and 254-nm UVC in the same gene. We demonstrate that T-->G transversions, a generally rare class of mutation, are induced at high frequency (up to 50%) in UVA-exposed cells. Furthermore, this event comprises a substantial proportion of the simulated sunlight-induced mutant collection (25%) but is significantly less frequent (P < 0.05) in cells irradiated with either UVB (9%) or UVC (5%). We conclude that the mutagenic specificity of broad-spectrum solar light in rodent cells is not determined entirely by the UVB component and that UVA also plays an important role.     

A subglottic foreign body mimicking croup: A case report

Introduction:Foreign body (FB) aspiration is one of the causes of respiratory distress in infants is an extremely dangerous and potentially life-threatening event. The diagnosis of FB aspiration is difficult because the signs and symptoms vary according to the degree of airway blockage or location of the FB.Patient concerns:An 11-month-old female infant visited a hospital because of a sudden onset cough. She was relatively healthy without fever, rhinorrhea cyanosis, or poor feeding. On physical examination, auscultation revealed inspiratory stridor without wheezing and crackles.Diagnosis:Croup was suspected when considering the history, physical examination, and imaging. However, she did not respond to a 4-day course of treatment for croup. Flexible laryngoscopic examination was performed, and we identified a thin, flat, and sharp FB embedded in the subglottic region.Interventions:Emergency surgery was performed to remove the FB. Short-term intravenous corticosteroids and antibiotics were used to prevent laryngeal swelling and aspiration pneumonia.Outcomes:One week after the procedure, the laryngeal mucosa had completely healed.Conclusion:FB aspiration should be considered in an infant with an impression of croup. In particular, if there is no response to medical or conservative treatment for croup, further evaluation is needed.     

A four-day workweek. A retrospective evaluation

Respiratory therapy managers are expected to provide quality patient care while keeping operational expenses at a minimum. One method that has been proposed for achieving this objective is a four-day workweek. Such a system was tried at Samaritan Hospital, Troy, NY, with disappointing results.     

A relativistic spherical vortex

This investigation is concerned with stationary relativistic flows of an inviscid and incompressible fluid. In choosing a density-pressure relation to represent relativistic “incompressibility,” it is found that a fluid in which the velocity of sound equals the velocity of light is to be preferred for reasons of mathematical simplicity. In the case of axially symmetric flows, the velocity field can be derived from a stream function obeying a partial differential equation which is nonlinear. A transformation of variables is found which makes the relativistic differential equation linear. An exact solution is obtained for the case of a vortex confined to a stationary sphere. One can make all three of the components of velocity vanish on the surface of the sphere, as in the nonrelativistic Hicks spherical vortex. In the case of an isolated vortex on whose surface the pressure is made to vanish, it is found that the pressure at the center of the sphere becomes negative, as in the nonrelativistic case.     

A Case of Thanatophoric Dysplasia Type 2: A Novel Mutation

Thanatophoric dysplasia (TD) is a lethal form of skeletal dysplasia with short-limb dwarfism. Two types distinguished with their radiological characteristics have been defined clinically. The femur is curved in type 1, while it is straight in type 2. TD is known to be due to a mutation in the fibroblast growth factor receptor 3 (FGFR3) gene. We report a male patient who showed clinical findings congruent with TD type 2 and a new mutation in the FGFR3 gene, a finding which has not been reported previously.     

A case of autoimmune hepatitis following acute hepatitis A

The pathogenesis of autoimmune hepatitis (AIH) is unclear, but viral infections have been proposed as a potential trigger in patients with genetic predisposition. We report a case of AIH following acute hepatitis A (AHA). A 57-year-old woman presented with fatigue and pitting edema for last 3 months. She had been diagnosed as an AHA 15 months ago based on clinical features, biochemical tests and positive HAV IgM antibody at a local clinic. Her biochemical tests was normalized one month after AHA diagnosis, but the serum levels of aminotransferase started to rise four months after AHA diagnosis. Antinuclear antibody was positive at a titer of 1:40, and anti-smooth muscle antibody was also positive. Hypergammaglobulinemia and liver pathology were typical for AIH. The patients had a score of 17 according to the International Autoimmune Hepatitis Group's system. She was given prednisolone and azathioprine and showed complete response to immunosuppressive therapy. The present case is the first report on AIH triggered by AHA in Korea.     

Hereditary Methemoglobinemia: A New Variant Exhibiting Dominant Inheritance of Methemoglobin A

1. A case of dominantly inherited methemoglobinemia is described.

2. Despite the pattern of autosomal dominant inheritance, the hemoglobinis thus far indistinguishable from methemoglobin A and is considered to benormal rather than one of the subtypes of hemoglobin M.

3. The primary defect is one in which there is a decreased capacity to reducemethemoglobin via the normal glucose dependent pathway.

4. The nature of the specific defect remains to be more completely elucidatedbut is considered not to result from a deficiency of TPN or DPN methemoglobinreductase.

5. Hereditary methemoglobinemia and hemoglobin M disease are reviewed.

Submitted on February 16, 1961 Accepted on May 6, 1961     

Carboxypeptidase A mechanisms.

The mode of binding of a ketonic substrate, which is an analogue of esters in which the O of the scissile bond is replaced by CH2, to carboxypeptidase A is similar to that of Gly-Tyr. The site is S'1, with the side chain in the pocket of the enzyme, the carboxylate salt-linked to Arg-145, and the carbonyl group bound to Zn. Thus, esters are probably cleaved at the peptide cleavage site, although not necessarily with the same rate-controlling step or by the same detailed mechanism. The large differences found between the behavior of the enzyme in solution and in one crystalline phase do not apply to a different crystalline phase.     

A case of coronary microfistula: A newborn microfistula

Coronary artery fistula is an abnormal connection between a coronary artery and a cardiac chamber, a great artery or the vena cava. Although coronary artery fistulas are known to be congenital malformations they might occur due to infection, trauma or may be iatrogenic. We present a case with acquired coronary microfistula, without any history of interventional procedure.     

A radioimmunoassay for prostaglandin A1 in human peripheral blood.

A specific, sensitive and accurate radioimmunoassay (RIA) method for the measurement of prostaglandin A1 (PGA1) in either human whole blood or plasma is described. Whole blood is immediately lysed with distilled water containing tritiated indicator. When plasma is assayed, the blood samples are handled at 4 C and rapidly centrifuged. The lysate or plasma is adjusted to pH 5 with buffer and quickly extracted with 5% methanol in dichloromethane. The whole blood or plasma extract is then purified by Sephadex LH20 chromatography using the system methanol: methylene chloride (5:95) which separates the major groups of PGA, PGE and PGF. The RIA is then performed using an antiserum generated in rabbits from PGA1 coupled to bovine thyroglobulin. The antibody is highly specific, possessing very low cross reactivity to other prostaglandins (PGA2, PGE, PGB and PGF). Activated florisil or ammonium sulfate can be used to separate bound from free prostaglandin. This whole blood or plasma method yields blank values of only 2 +/- 2 pg per sample with a between assay precision determined by duplicate analysis of 8% and interassay precision of 3%. The mean whole blood PGA1 concentration in 27 subjects in 2.5 +/- 1.6 (SD) ng per 100 ml. No significant sex difference in PGA1 levels was noted and values were similar whether measured in whole blood or cooled plasma rapidly prepared and extracted. These values of PGA1 are much lower than those RIA values reported by others for "PGA" using antibodies with lower specificities.     

A case of group A streptococcal meningitis in an adult

Group A streptococci are an important cause of soft tissue infections but have rarely been reported as the cause of pyogenic meningitis since the advent of antibiotics. A case of group A streptococcal meningitis in an adult is presented along with a review of similar cases reported in the literature. This case serves to illustrate the virulent nature of this pathogen in infections of the meninges, the potential for associated complications, and the need for rapid diagnosis and appropriate treatment. The source of infection in this and many other cases in the literature is the upper respiratory tract. The case presented responded well to antibiotics but resulted in permanent auditory-vestibular dysfunction.