The sequence within two primers influences the optimum concentration of dimethyl sulfoxide in the PCR.
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Base Sequence↗
Biomedical subjects
L B Johnson
Publications and source records attributed to L B Johnson.
Triiodothyronine enhances renal tubule cell replication by stimulating EGF receptor gene expression.
Thyroid hormone is known to accelerate renal function recovery following toxic acute renal failure. Because epidermal growth factor (EGF)-receptor activation is most likely critical in renal replicative repair, these studies were undertaken to assess whether triiodothyronine (T3), the most active form of thyroid hormone, may modulate EGF-induced renal proximal tubule cell proliferation by an effect on the EGF receptor. Rabbit renal proximal tubular cells were grown in primary culture and treated with or without T3 (0.1 or 1.0 nM) for 24 to 48 h. Compared with nontreated controls, T3 exposure led to significant increases in EGF-promoted DNA synthesis, as measured by [3H]thymidine incorporation, in renal tubule cells. Furthermore, T3 treatment resulted in increases in EGF receptor mRNA in proximal tubule cells compared with nontreated cells and was associated with elevated numbers of EGF receptors on the cell surface of proximal tubule cells. EGF binding studies demonstrated that T3 treatment had only modest effects on Kd values of both the high-affinity binding site (0.19 nM) and the low-affinity binding site (3.7 nM) but substantially increased the maximal number of high-affinity sites from 3.8 x 10(3) to 9.4 x 10(3) receptors/cell and the maximal number of low-affinity sites from 132 x 10(3) to 199 x 10(3) receptors/cell. These findings suggest that a T3 effect to increase EGF receptor gene expression with resulting increases in the number of cell surface EGF receptors on renal proximal tubule cells and a potentiated mitogenic response to EGF may be a mechanism for thyroid hormone to enhance renal function recovery following toxic acute renal failure.
Animals↗
Effectiveness of a stress recovery unit during the Persian Gulf War.
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Adult↗
Salivary function of persons with hereditary epidermolysis bullosa.
Oral alterations of the hard and/or soft tissues are commonly associated with the different types of epidermolysis bullosa (EB). The relationship of oral soft and hard tissue changes to the disease mechanisms in different EB types remains to be elucidated. The purpose of this investigation was to evaluate selected aspects of salivary function in a healthy control population and in persons affected with different types of EB. Sixty-one patients with EB, representing all the major types of EB, and 36 unaffected persons were examined to measure their stimulated salivary flow rates and salivary levels of IgA, albumin, and total protein. Our results show that none of the types of EB demonstrated a decreased salivary flow rate. However, patients with recessive dystrophic EB had significantly elevated salivary IgA, albumin, and total protein levels. The increased IgA level seen in this form of EB appears most likely to be related to the high prevalence of oral blistering rather than the result of altered mucosal immune function. Despite severe cutaneous and extracutaneous involvement associated with inherited EB, we found no evidence to support the hypothesis of abnormal salivary function or mucosal immunity in this disease. Taken together, these findings suggest that the rampant dental caries seen in the severe forms of EB are likely attributable to nonsalivary factors such as enamel involvement, soft tissue alterations, and/or diet. Alternatively, there may be mucosal immunity or salivary enzyme alterations that influence oral disease in these patients, but these were not evaluated in this investigation.
Adolescent↗
Oral soft tissues in hereditary epidermolysis bullosa.
Epidermolysis bullosa (EB) is associated with diverse oral manifestations, which can potentially involve both hard and soft tissues, depending on the specific EB subtype. This study determined the frequency and extent of oral soft tissue involvement in the inherited forms of EB. Examination of 216 affected persons revealed significant differences in the oral soft tissue involvement among the various types of EB. The frequency of oral involvement was greater in the dominant dystrophic (81.1%) and simplex (generalized, 58.6%; localized, 34.7%) types than previously reported. The marked frequency of oral blistering was similar in both major subtypes of junctional (Herlitz, 83.3%; non-Herlitz, 91.6%) and recessive dystrophic EB (generalized, 100%; localized, 92.3%). Obliteration of the oral vestibule, ankyloglossia, and microstomia were consistent findings in generalized recessive dystrophic EB. Oral milia were present in all major EB categories, most prevalently in the dystrophic forms, but were not seen in all the distinct EB subtypes. These findings indicate that although there are no pathognomonic intraoral soft tissue manifestations in the various forms of inherited EB, there are predictable patterns of involvement associated with specific subtypes of this disease. Understanding the oral involvement associated with EB may aid clinicians in the development of more advanced therapeutic approaches that are compatible with and directed at the unique characteristics of each EB subtype.
Blister↗
HLA and epidermolysis bullosa: evidence for independent assortment of Weber-Cockayne subtype of epidermolysis bullosa and HLA complex.
The purpose of this study was to examine the genetic linkage (but not the association) between HLA complex and Weber-Cockayne Subtype of epidermolysis bullosa (EBS-WC). We HLA typed 44 members of three multi-generation families in which 24 members have the clinical evidence of EBS-WC. The patterns of inheritance of various HLA haplotypes and the disease were mathematically analyzed to estimate frequency of recombination (i.e. genetic distance) between HLA complex and the disease by calculating Lod Scores for each family separately as well as all for three families combined. Our results show that only one family had a positive Lod Score. The Lod Scores for the remaining two families as well as the combined Lod Score for all three families were negative. These data suggest that odds are against the genetic linkage between HLA complex and Weber-Cockayne Subtype of epidermolysis bullosa and in favor of independent assortment of the disease and HLA complex.
Chromosome Mapping↗
The effect of size of giant pancreatic pseudocysts on the outcome of internal drainage procedures.
Pancreatic pseudocysts (PP) that fail to resolve spontaneously are optimally treated by internal drainage to a viscus. Pseudocysts adherent to the stomach are usually drained by way of cystgastrostomy. Recent experience with giant pseudocysts (greater than 15 centimeters), however, challenges this approach. Fifty-two patients with pancreatic pseudocysts of various sizes were treated from 1982 to 1986 at the Massachusetts General Hospital. Twenty-eight PP were suitable for internal drainage. The postoperative complication rate was directly proportional to the size of the pseudocyst. Four patients had giant PP, three of which occurred after an attack of acute pancreatitis. All four were treated by cystgastrostomy. Three of four patients with giant pseudocysts had life-threatening postoperative complications as a result of incomplete emptying of the cyst, and two patients died. No evidence of anastomotic leakage could be demonstrated by upper gastrointestinal series or computed tomographic scans. Transgastric drainage tubes in these three instances were not protective. We conclude that cystgastrostomy may not be appropriate for the treatment of giant pancreatic pseudocysts because it fails to provide dependent drainage of a large cyst cavity. If internal drainage is performed, the cyst should be anastomosed to a defunctionalized loop of jejunum in a dependent position. In some instances, external drainage of giant pancreatic pseudocysts may be safer than cystgastrostomy.
Adolescent↗
HLA and epidermolysis bullosa. Association between the HLA complex and recessive dystrophic epidermolysis bullosa.
BACKGROUND AND DESIGN: --Epidermolysis bullosa refers to a group of genetic diseases characterized by marked skin fragility and blister formation following minor mechanical trauma. The patients with recessive dystrophic epidermolysis bullosa (RDEB) are the most severely affected with marked internal and external blistering, scarring, and death at an early age, secondary to malnutrition, septicemia, and/or metastatic squamous cell carcinoma. An association between RDEB and HLA antigens was explored in 28 patients with RDEB and their family members. RESULTS: --Our data demonstrate that susceptibility to develop RDEB may be associated with the HLA complex. The gene frequencies of DR4 and DQw3 were much higher in the patients than expected. These increases were likely due to statistically significant excess of DR4 and DQw3 homozygotes in the patients. In addition, the observed frequencies of two HLA haplotypes: Bw62, DR4, DQw3 and Bw60, DR4, DQw3 were significantly higher than expected. CONCLUSION: --If these observations are confirmed in the larger series of patients, the association between RDEB and HLA complex may have clinical utility in genetic counseling of siblings of child-bearing age who are at risk of being carriers of RDEB.
Adolescent↗
Inherited blistering diseases of the skin.
Inherited epidermolysis bullosa (EB) comprises some 23 different phenotypic disorders which have as common features the presence of mechanically fragile skin and the tendency to develop blisters, erosions, and in some cases, scarring of the skin. While some forms of this disease are relatively mild, other rarer variants may prove to be life-threatening. In the past 15 years, a wealth of new information has elucidated new clinical and laboratory characteristics of specific EB subsets. In this brief review, the most important aspects of inherited EB are summarized to update the practicing pediatrician about the ever-increasing complexities being discovered about this disease.
Basement Membrane↗
Type VII collagen and 19-DEJ-1 antigen. Comparison of expression in inversa and generalized variants of recessive dystrophic epidermolysis bullosa.
The expression of type VII collagen and 19-DEJ-1 antigen was examined in 73 and 71 patients, respectively, with recessive dystrophic epidermolysis bullosa (RDEB), comprising gravis, mitis, inversa, and indeterminant subsets, to better determine the specificity and sensitivity of two monoclonal antibodies directed against these dermoepidermal junction-specific epitopes. Type VII collagen (LH 7:2 epitope) was usually absent (in 90%) in patients with the gravis variant of RDEB, whereas its expression was most often diminished (in 67%) in those with the mitis form of the disease. Only 2% and 5% of patients with gravis and mitis variants, respectively, had apparent normal amounts of type VII collagen within their skin. In contrast, six (86%) of seven patients with the inversa variant had normal expression of the antigen. Only 25% of all patients with RDEB lacked the 19-DEJ-1 antigen; of these, however, most had the gravis variant, although absence or diminution was also infrequently observed in those with the mitis and inversa forms. Intermediate findings were noted in patients classified as having indeterminant forms of RDEB. Some variability in antigen expression was also noted among affected siblings. We conclude that assessment of expression of the LH 7:2 epitope of type VII collagen may be diagnostically useful, although considerable overlap does exist between individual patients with gravis and mitis forms. 19-DEJ-1 expression is a far less sensitive probe in RDEB, although such data may prove useful in the assessment of newborns lacking the characteristic features of gravis disease. In addition, based on our experience with inversa RDEB, it would appear that altered expression of type VII collagen cannot be attributed to blister formation in this latter rare subset, since this antigen is usually strongly detected along the dermoepidermal junction, even in perilesional skin sites.
Antibodies, Monoclonal↗
Inherited epidermolysis bullosa in Croatia.
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Epidermolysis Bullosa↗
Interaction of harderian glands, illumination, and temperature on thyroid hormones in golden hamsters.
In this study, Harderianectomy (Hdx) has been shown to differentially modify circulating levels of the thyroid hormones, T4 and T3, in male and female golden hamsters exposed to low photic intensities or to moderately low temperatures. Specifically, low photic intensities depress circulating levels of T4 in both control and Harderianectomized (Hdx) male and female hamsters. In addition, T3 is decreased in both control and Hdx males but not in females, as a consequence of reduced levels of illumination. Moderately low temperatures (10 degrees C) depress T4 in both control and Hdx males but not in females, while T3 is increased in both control male and female hamsters, and in Hdx males, but not Hdx females. The data suggest that the Harderian gland of males enhances the sensitivity of the TSH-thyroid axis to photic intensity and to lower temperatures, and further, that there is a considerable sexual difference in the role the Harderian glands may play in response to these two environmental factors.
Animals↗
Regulation of melatonin in the harderian glands of golden hamsters.
A daily rhythm in melatonin concentration in Harderian glands (HG) of female golden hamsters is described and is characterized by significant reductions following lights-on. Concentrations in HG of intact or pinealectomized males are low and consistent over a 24-hour period. Castration of males is accompanied by increased levels of melatonin in the HG to approach those of females. When castrated males are exposed to short photoperiods, however, melatonin levels are typically low. Levels of serotonin (5-HT), 5-hydroxytryptophan (5-HTP), and 5-hydroxyindoleacetic acid (5-HIAA) are extremely variable in GH of both males and females, precluding definitive conclusions. Melatonin concentrations in HG of females do not appear to be affected by light or stress per se, nor are the superior cervical ganglia the pathway by which concentrations are modified.
Animals↗
Influence of diet on photoperiod-induced gonadal regression in female hamsters.
Introduction of a seed/nut mixture (Lyric) to the diet of female golden hamsters was found to stimulate growth as well as to effect a delay in the reproductive response to a short photoperiod. In a series of experiments we found that 1) growth rates of hamsters offered the Lyric diet alone or in conjunction with the standard rodent diet exceeded those of hamsters offered only the standard rodent diet. 2) Hamsters fed the standard rodent diet for eight weeks, followed by the Lyric diet for four weeks remained reproductively functional in a short photoperiod; however, 3) most hamsters that were fed the Lyric diet or the standard rodent diet continuously for 12 or 16 weeks experienced reproductive atrophy in short photoperiods; 4) The presence of a vitamin/mineral supplement in the Lyric diet did not affect the incidence of reproductive degeneration in hamsters fed this diet continuously for 12 weeks; however, 5) the vitamin/mineral supplement in this experiment did influence weight gain in hamsters exposed to short photoperiods. We conclude that the Lyric diet, offered as a novel food source after eight weeks on a standard rodent diet, acts to delay the onset of reproductive atrophy in hamsters exposed to short photoperiods. The mechanism for such an effect is not known at this time.
Animals↗
The importance of early diagnosis of acute acalculus cholecystitis.
Most observations of acute acalculus cholecystitis have been reported in patients after trauma, after unrelated surgical treatment and in critically ill patients, patient populations in whom the diagnosis of this condition is difficult. The importance of making an early diagnosis is demonstrated by the rapid development of complicated forms of cholecystitis. The results of collective reports have indicated that 40 to 100 per cent of the patients with acute acalculus cholecystitis will have advanced disease with gangrene, empyema or perforation of the gallbladder at operation. To demonstrate the importance of early suspicion and the use of sonography in making the diagnosis of this condition, a retrospective study of 40 patients with a surgical and pathologic proved diagnosis of acute acalculus cholecystitis was conducted. The fulminant nature of this disease was underscored by the fact that 70 per cent of these patients had advanced disease. Patients were divided into two groups, those who underwent operation within 48 hours of the onset of symptoms and those whose surgical treatment was delayed. Forty per cent of the patients who underwent operation more than 48 hours after the onset of symptoms had gallbladder perforation, while only 8 per cent of the patients without a delay in surgical treatment of more than 48 hours had perforations. Since advanced disease, especially perforation, carries a much higher morbidity and mortality than uncomplicated cholecystitis, making an early diagnosis is of paramount importance. Therefore, heightened awareness on the part of physicians is a key in making an early diagnosis. In 25 per cent of the patients in this study, unexplained fever was the first sign of the disease. Although most patients later presented with more classic symptoms of cholecystitis, many of these patients still presented with confusing clinical signs and symptoms leading to a delay in diagnosis due to the coexistence of the post-trauma, postsurgical or critically ill state. Ultrasound proved to be an important adjunct to the often confusing clinical clues in making an early diagnosis. Three ultrasonographic signs in the absence of stones--1, a thickened gallbladder wall; 2, an enlarged tender gallbladder, and 3, a pericholecystic collection--were suggestive of acute acalculus cholecystitis. One of these findings was present in almost 90 per cent of the patients in this study with acute acalculus cholecystitis who underwent biliary ultrasound.
Acute Disease↗
A comparison of statistical techniques for analysis of growth curves.
Frequently, experiments are conducted in order to investigate the effects of various treatments on an animal's growth rate. The data from these investigations usually consist of each animal's body weight or accumulative weight gain at specific times during the experiment. The most common statistical techniques for analysis of growth rates (increments in body weight over time) consider only terminal body weights or final accumulative weight gain. In this study, we compare growth rates over the duration of the experiment and use standard simultaneous testing procedures in order to accommodate more than two treatment groups. Results obtained by comparison of regression lines randomization analysis of variance, and repeated measures analysis are presented.
Analysis of Variance↗
Harderian glands of golden hamsters: temporal and sexual differences in immunoreactive melatonin.
Throughout a 24-h period, immunoreactive melatonin concentrations in Harderian glands of female golden hamsters were approximately 200 pg/mg protein with a significant decline to 80 pg/mg protein only at about 0600, 2 h after light on. Concentrations in glands of males are diurnally constant and low (ca. 20 pg/mg protein). Castration increases immunoreactive melatonin in glands of males to female levels. While blinding alone had no effect, it did prevent the castration-induced increase. Lower concentrations were measured in glands of blinded or blinded ovariectomized females but this decrease was not significant. These data suggest that immunoreactive melatonin concentrations in the Harderian glands of hamsters are controlled by testosterone or its derivatives; these same factors also control the male or female character of these glands.
Androgens↗
Effects of photic history and illuminance levels on male golden hamsters.
Four-week-old male hamsters, born and raised in total darkness or in LD 14:10 (hr) were exposed to several low levels of illumination for 14 weeks. Analyses showed that testicular weights were significantly affected by both photic history and illuminance levels. Animals born in the dark possessed larger testes than those born in LD cycles and, further, displayed less responsiveness to levels of illumination below those required to suppress pineal function. While gonadal responses to photic duration may be said to be "all or none," those resulting from insufficient illuminance levels are seemingly graded. Thus, the pineal gland may act indirectly as a photodosimeter at low illuminance levels.
Adrenal Glands↗