De novo lupus nephritis after SARS-CoV-2 infection

The relationship between viral infection and onset of autoimmune diseases such as systemic lupus erythematosus remains uncertain. During the COVID-19 pandemic, organ-specific and multisystemic autoimmune phenomena temporally related to the viral infection have been described. Immune dysregulation triggered by the SARS-CoV-2 virus leading to hyperactivation of both the innate and adaptive immune systems contributes to the excessive production of pro-inflammatory cytokines, autoantibodies, and subsequent autoimmune manifestations. We report two patients without known autoimmune diseases who developed lupus nephritis shortly after a documented mild SARS-CoV-2 infection. Together with other similar cases in the literature, the observation supports a viral trigger of the development of systemic lupus erythematosus in susceptible individuals.

Retrospective Review of Documentation Practices of Hepatitis B Immunoglobulin, Birth Dose, and Vaccination at the Hospital of Birth, in Thai Nationals and Migrants in Northern Thailand

Background

Vaccination remains the mainstay of prevention of hepatitis B virus (HBV) including birth dose and hepatitis B immunoglobulins (HBIGs). National estimates of vaccination coverage exclude migrants. The objective of this study is to investigate documentation practices of HBV-related infant vaccinations in Northern Thailand including migrants.

Methods

This is a retrospective review of hospital records of women who birthed infants in 2015 at Maharaj Nakorn Hospital, Chiang Mai (CM) or on the Thailand-Myanmar border, Tak.

Results

Of 2522 women, 987 were from CM (861 Thai nationals, 126 migrants) and 1535 were from Tak (651 Thai residence and 884 Myanmar residence). In CM, documentation for the birth dose vaccine (999 of 999, 100%) and HBIG was complete. In Tak, documentation was 1441 of 1549 (93%) for birth dose and 26 of 34 (76.5%) for HBIG, with missed opportunities including home delivery, delay in obtaining hepatitis B e-antigen status, and limitations of the records. Expanded Program of Immunization (EPI) documentation of 3 follow-up vaccinations dwindled with subsequent doses and distance, and complete documentation of 3 HBV EPI vaccines at the hospital of birth was low, 41.5% (1056 of 2547), but equitable for Thai or migrant status.

Conclusions

This review provides strong support for excellent documentation of HBIG and birth dose vaccination in urban and rural settings, and in migrants, consistent with Thailand's vaccination policy and practice. Documentation of the 3 HBV EPI at the hospital of birth decreases with sequential doses, especially in families further away. Innovative data linkage is required to prove coverage and identify gaps.

Diagnosis and treatment of primary Sjogren’s syndrome: an update

Primary Sjogren’s syndrome (SS) is a systemic autoimmune disease that primarily affects the exocrine glands, resulting in dryness of the mucosal membranes, particularly of the eyes and mouth. Considerable advance has been made for the classification and treatment of primary SS in the past few years. This article reviews the recent classification criteria for primary SS and briefly discusses the conventional and novel therapies of the disease.

Spin cloud induced around an elastic scatterer by the intrinsic spin hall effect

Similar to the Landauer electric dipole created around an impurity by the electric current, a spin polarized cloud of electrons can be induced by the intrinsic spin Hall effect near a spin independent elastic scatterer. It is shown that in the ballistic range around the impurity, such a cloud appears in the case of Rashba spin-orbit interaction, even though the bulk spin Hall current is absent.

Spin Hall effect on edge magnetization and electric conductance of a 2D semiconductor strip

The intrinsic spin Hall effect on spin accumulation and electric conductance in a diffusive regime of a 2D electron gas has been studied for a 2D strip of a finite width. It is shown that the spin polarization near the flanks of the strip, as well as the electric current in the longitudinal direction, exhibit damped oscillations as a function of the width and strength of the Dresselhaus spin-orbit interaction. Cubic terms of this interaction are crucial for spin accumulation near the edges. As expected, no effect on the spin accumulation and electric conductance have been found in case of Rashba spin-orbit interaction.

Strain-induced coupling of spin current to nanomechanical oscillations

We propose a setup which allows us to couple the electron spin degree of freedom to the mechanical motions of a nanomechanical system not involving any of the ferromagnetic components. The proposed method employs the strain-induced spin-orbit interaction of electrons in narrow gap semiconductors. We have shown how this method can be used for detection and manipulation of the spin flow through a suspended rod in a nanomechanical device.

Survival of BRCA1 negative ovarian cancer patients based on family history

OBJECTIVE

To compare survival of ovarian cancer patients with and without a family history of breast or ovarian cancer who are known to be without mutations in BRCA1.

METHODS

Patients with ovarian cancer were tested for germline mutations in BRCA1 by polymerase chain reaction amplification of DNA for single-strand conformation polymorphism and direct sequencing analysis to examine the 22 coding exons of BRCA1 in fresh and archived tumor specimens. Demographic and survival data were collected for statistical analysis. Survival data were calculated by the method of Kaplan and Meier and compared by the log-rank test.

RESULTS

Of the 110 patients tested at our institution, 100 were noted to be negative for BRCA1 mutations. After exclusion of nonepithelial histologies, benign tumors, primary peritoneal carcinoma, and incomplete staging, 87 patients remained for analysis, of which 37 demonstrated a family history of breast or ovarian cancer. The two groups showed similar age at diagnosis, stage, grade, residual disease, and type of chemotherapy. Median actuarial survival was 75 months for those patients with a family history versus 70 months for those without (P = 0.73). Evaluation of patients with two or more relatives with breast or ovarian cancer also revealed no differences in survival.

CONCLUSIONS

Family history of breast or ovarian cancer does not affect survival of patients with ovarian cancer in the absence of mutations in BRCA1. Previously described differences in survival among patients with BRCA1 mutations may be more related to genetic factors than to biases introduced by the presence of family history.

Regulatory CD4(+)CD25(+) T cells in tumors from patients with early-stage non-small cell lung cancer and late-stage ovarian cancer

Immunosuppression may contribute to the progression of cancer. In this study we assessed the structural and functional status of T cells from tumor specimens obtained from patients with early stage non-small cell lung cancer and late-stage ovarian cancer. Although some groups have described structural alterations in the TCR in patients with other malignancies, we did not observe decreased expression of the CD3zeta subunit in the tumor-associated T cells. However, increased percentages of CD4(+)CD25(+) T cells were observed in the non-small cell lung cancer tumor-infiltrating lymphocytes and ovarian cancer tumor-associated lymphocytes. Furthermore, these CD4(+)CD25(+) T cells were found to secrete transforming growth factor-beta, consistent with the phenotype of regulatory T cells. Despite a generalized expression of lymphocyte activation markers in the tumor-associated T-cell populations, the CD8(+) T cells expressed low levels of CD25. To determine whether expression of CD25 could be restored on the CD8 cells, tumor-associated T cells were stimulated with anti-CD3 and anti-CD28 monoclonal antibodies. After stimulation, nearly all of the CD8 T cells expressed CD25. Furthermore, despite the low levels of interleukin 2, IFN-gamma, and tumor necrosis factor-alpha secretion by the tumor-associated and peripheral blood T cells at baseline, stimulation with anti-CD3 and anti-CD28 monoclonal antibodies significantly increased the fraction of cells producing these cytokines. Thus, tumor-associated T cells from patients with early and late-stage epithelial tumors contain increased proportions of CD4(+)CD25(+) T cells that secrete the immunosuppressive cytokine transforming growth factor-beta. Furthermore, our results are consistent with previous reports showing impaired expression of CD25 on CD8(+) T cells in cancer patients. Finally, increased lymphocyte costimulation provided by triggering the CD28 receptor is able to increase CD25 expression and cytokine secretion in tumor-associated T cells. These observations provide evidence for the contribution of regulatory T cells to immune dysfunction in cancer patients.

Second-look laparotomy for epithelial ovarian cancer: a reappraisal

Although second-look laparotomy (SSL) has been used in the management of ovarian cancer for over three decades, its current clinical use is limited. On average, over 50% of patients with a clinical complete response are noted to have disease at the time of SLL, emphasizing our lack of accurate noninvasive methods for determining pathologic response. Although findings at SLL have some prognostic significance, there is no definitive evidence that those patients undergoing SLL have improved survival, and even 50% of patients with negative findings at SLL have recurrences. The lack of survival advantage for patients enduring SLL highlights the need to identify consistently effective salvage and consolidation regimens. Few published studies provide definitive evidence regarding efficacy of treatment. Prospective, randomized, controlled trials are needed to evaluate the various therapies available. In general, the performance of SLL should be confined to those patients enrolled in clinical trials.

Accelerated healing with a mesh autograft/allodermal composite skin graft treated with silver nylon dressings with and without direct current in rats

PURPOSE

Evaluation of the healing and persistence of a meshed composite skin graft applied without immunosuppression.

METHODS

The contraction of wounds grafted with 9:1 split-thickness autograft/1.5:1 allodermal mesh composite skin grafts (auto/allo MCSGs) was investigated. No immunosuppressive agent was applied. Male ACI rats and female Lewis rats reciprocally served as allodermis graft donors and recipients. Autograft/dermal autograft and allograft/dermal allograft MCSGs were the controls.

RESULTS

AT 3 months after grafting, when epithelized auto/allo MCSG wounds were measured by computerized morphometric analysis, the silver nylon (SN) dressing group displayed less contraction than the Vaseline (petroleum jelly) dressing group (p < 0.003), and direct current treatment (SNDC) was more effective than SN (p < 0.005). The histologic structures of the hair follicles appear to confine the rejection process to the allogeneic follicles of the graft. The focal nature of the rejection process and the relatively low antigenicity of the dermal matrix allowed the survival of the allodermis layer. Although direct current significantly enhanced MCSG healing, SN and SNDC were not the immunosuppressive agents that were confirmed.

CONCLUSION

This type of MCSG can heal without immunosuppressive treatment.

Direct current reduces accumulation of Evans Blue albumin in full-thickness burns

BACKGROUND

Application of direct current (DC) to a burn wound limits extension of the zone-of-stasis and reduces wound tissue edema.

OBJECTIVE

To study the effects of DC on extravasation of plasma proteins after burn by using Evans blue (EB) as a marker of plasma albumin.

MATERIALS AND METHODS

Male Sprague-Dawley rats with 20% total body surface area full-thickness scalds (100 degrees C/10 sec) were used as the experimental model. Burn wounds were treated with plain nylon, silver-nylon, silver-nylon and 40 microA DC, or no dressing. EB (30 mg/kg) was injected immediately or at variably delayed postburn (PB) times and accompanied by DC application at various time intervals PB. Tissue content of Evans blue was assessed at different times after injection of the dye or infliction of burn injury.

RESULTS

Evans blue albumin (EBA) concentration in untreated burn wounds (307.7 microg/g tissue) was nine times greater than in unburned skin (36.5 microg/g tissue) at 48 hours PB. When animals received a DC and EB injection immediately PB, DC treatment reduced EBA concentration by 60% at any time point PB. When EB was injected immediately PB, or at variably delayed times PB, accompanied by DC immediately PB, or at variably delayed times PB, DC reduced EBA accumulation at all examined times PB by more the 50% (p < 0.001).

CONCLUSION

EBA and edema fluid accumulation in burn wound change in concert after injury and show similar response to DC treatment.

The accumulation of chromosome aberrations and Dlb-1 mutations in mice with highly fractionated exposure to gamma radiation

The dichotomy between the doses at which experimental measurements of genetic effects can be made and the doses to which people are exposed is often different by two or more orders of magnitude. This presents a significant problem when determining the effects of low doses of radiation or chemicals. The solution has usually involved extrapolating the data by curve-fitting or by applying theoretical considerations. Both approaches are unsatisfactory due to uncertainties of the assumptions used in each process. The alternative solution has been to increase the sample size enormously at the lower doses. This is impractical beyond a certain point due to the variation in the spontaneous frequency and the need to quadruple the sample size for a doubling of precision. The development of new methods for measuring stable genetic effects, however, permits a simple and effective approach to this problem: if the genetic events being detected have no effect on survival, i.e., are selectively neutral, then the effects of multiple independent treatments will be additive. If the independent treatments are identical, then the effect of each is easily calculated by dividing the total effect by the number of treatments. Here we report a limited test of this approach using mice. Chromosome aberrations induced in lymphocytes and Dlb-1 mutations induced in the small intestine were measured after daily doses of 0.64, 1.85 or 5.5 cGy 137Cs gamma rays administered for 21, 42 or 63 days. The dose response curve for chromosome translocations obtained in this way, combined with the data from single larger acute doses, shows no evidence for a threshold over a 500-fold dose range. Dlb-1 mutations were increased at each dose and time but the results do not permit reliable extrapolations. The results suggest that translocations might be useful for quantifying the effect of doses below 0.05 cGy and that the effect of dose rate and dose fractionation at much lower doses than reported here could be investigated.

Management of congenitally missing maxillary lateral incisors

Congenitally absent maxillary permanent lateral incisors often lead to an unattractive appearance and difficulties in treatment planning. Many factors must be considered before a decision is made either to close spaces and modify the canines, or to redistribute the spaces and replace the missing teeth with prostheses. Good communication among patients, parents, dental specialists, and general practitioners is necessary.

Requirements of an impression material for fixed prostheses

This article reviews the clinical and laboratory steps in taking impressions for creating fixed prostheses. Recommendations for selecting impression materials and techniques for using them are discussed. Common problems associated with impressions, and their possible causes, are also included.

Optimized mesh expansion of composite skin grafts in rats treated with direct current

BACKGROUND

The purpose of this study was to determine the optimum autoepidermal and allodermal expansion ratio of each component of a meshed composite skin graft (MCSG) that would lead to successful healing.

METHODS

Male Sprague-Dawley rats were used as hosts of the MCSG and donors of autologous tissue. Male ACI rats were used as donors of allodermis. MCSGs with open meshed area (autoepidermal/allodermal) of 9:1/1.5:1, 9:1/3:1, 9:1/6:1, or 6:1/6:1 were applied to full-thickness skin defects and treated with a silver nylon dressing (SN) or SN with direct current (DC). Wound size, hair regrowth, and thickness of dermal layer were evaluated at 3 months.

RESULTS

MCSGs of 9:1/1.5:1, 9:1/3:1, and 6:1/6:1 mesh ratios healed completely within 3 months with no difference in wound size between SN dressing groups or DC-treated groups. Application of DC reduced MCSG contraction and stimulated regrowth of hair.

CONCLUSION

Fresh autoepidermis can be expanded 6:1 on a 6:1 allodermis or 9:1 on a 3:1 allodermis and achieve successful wound healing.

Correlation of toxic signs, ultrasonographic findings and pathological changes in cholecystitis

BACKGROUND

Cholecystitis is a frequently encountered clinical problem. What parameters are reliable in helping predict its severity?

METHODS

One hundred and forty-nine cholecystectomized cases of cholecystitis were analysed of which 99 (95 calculous) cases were pathologically diagnosed as chronic cholecystitis and 50 acute (43 calculous) cholecystitis. Medical records were reviewed to determine the frequency of toxic signs. Sonographic findings (performed within three days prior to operation), and final pathological changes with respect to the thickness and echotexture of the gallbladder wall were compared.

RESULTS

Of 99 chronic cholecystitis patients, 13 cases showed toxic signs. Sonography detected an abnormal wall in 64, but made a correct diagnosis in only 34 cases. A great discrepancy was found in wall thickness as measured by sonography and pathology. A discrepancy > or = 2mm was noted in 19 cases. Of 50 patients with acute cholecystitis (20 cases had complications, defined as severe acute cholecystitis), 31 cases (14 of the 20 severe acute cases) showed toxic signs. Sonographic findings demonstrated an abnormal wall in 46 cases (19 of the severe acute cases) and an accurate diagnosis in 28 cases (13 of the severe acute cases). A difference in the measurement of gallbladder wall thickness > or = 2mm was noted in 26 patients.

CONCLUSIONS

Clinical toxic signs and sonographic findings could not offer sufficient information to quickly identify lifethreatening gallbladder diseases.

Direct current reduces plasma protein extravasation after partial-thickness burn injury in rats

OBJECTIVE

To observe the effect of 40 microA direct current (DC) on plasma albumin extravasation after burn injury.

DESIGN, MATERIALS, AND METHODS

Silver-nylon wound dressings were used as anodes (-) on anesthetized male Sprague-Dawley rats with 20% total body surface partial-thickness scald burns. Burned rats with no treatment, or treated with silver-nylon dressing without current, were used as controls. Quantitative analysis of fluorescein isothiocyanate (FITC)-albumin leakage and accumulation in the wound tissue was performed using confocal fluorescence microscopy.

MEASUREMENTS AND MAIN RESULTS

In controls, the rate of albumin leakage was maximal at 1 hour postburn (PB) and then decreased, but remained higher than normal for 48 hours PB. The accumulation of FITC-albumin was maximal 4 to 6 hours PB and substantial for 48 hours. When DC was applied, leakage was reduced by 30 to 45% and approached normal control rates by 8 hours PB. FITC-albumin concentration peaked 4 hours PB, was 18 to 48% less then in burned control, and approached the level observed in unburned control by 18 hours PB.

CONCLUSIONS

DC has a beneficial effect in reducing plasma protein extravasation after burn injury.

Direct current reduces wound edema after full-thickness burn injury in rats

OBJECTIVE

To observe the effect of 4 and 40 microA direct current (DC) on edema formation after burn injury in rats.

DESIGN, MATERIALS, AND METHODS

Silver-nylon wound dressings were used as either anodes (-) or cathodes (+) on 20% total body surface area full-thickness scalds in anesthetized male Sprague-Dawley rats. Untreated burned rats and rats treated with silver-nylon dressings without current were used as controls.

MEASUREMENTS AND MAIN RESULTS

Immediately applied, continuous DC reduced burn edema by 17 to 48% at different times up to 48 hours postburn (p < 0.001). Neither reversal of electrode polarity nor change in current density had any significant effect on the results of treatment. Starting treatment during the first 8 hours postburn produced the least edema accumulation, but the reduction was significant even when DC was applied 36 hours afterburn. If started immediately after injury, treatment had to be continued a minimum of 8 hours to be most effective.

CONCLUSIONS

Direct electric current has a beneficial effect in reducing wound edema after burn injury.

The oral prevalence of aerobic and facultatively anaerobic gram-negative rods and yeasts in semi-recluse human vegetarians

Limited data exist on the oral ecology of vegetarians. Hence the dental and periodontal status, and the oral prevalence of aerobic and facultatively anaerobic Gram-negative rods (AGNR) and yeasts, were studied in 36 semi-recluse, vegetarian, Buddhist monks and nuns in Hong Kong. The oral prevalence of AGNR and yeasts was 61.1% and 33.3%. There was no correlation between the prevalence of AGNR and/or yeasts and the incidence of carious or filled teeth and the health status of the periodontium. Rather, the results of this study combined with those of previous studies suggest that increasing age and the consumption of food prepared in communal kitchens might be more important contributory factors in the oral prevalence of AGNR than the nature of the diet itself or the health of the dentition and periodontium.

Enhanced survival of autoepidermal-allodermal composite grafts in allosensitized animals by use of silver-nylon dressings and direct current

OBJECTIVE

Observe the effect of silver-nylon (SN) dressing and direct electric current on healing of meshed autoepidermal/allodermal composite skin grafts (MCSGs) in allosensitized rats.

MATERIALS AND METHODS

MCSGs were placed on experimental animals 28 to 30 days after placement of sensitizing allografts. MCSGs and control allografts were covered with either Vaseline gauze (VG) or SN; direct current, 40 microA, was applied for 5 days to some of the SN-dressed wounds (SNDCs).

MEASUREMENTS AND MAIN RESULTS

Second set rejection of MCSG was not observed. SN- and SNDC-treated grafts showed expansion of the meshed autoepidermis with complete epithelialization within 3 weeks. VG-covered wounds developed areas of open granulation and were not completely epithelialized at 3 months. Both SN and SNDC reduced wound contraction when compared to VG (SN versus VG p < 0.02, SNDC versus VG p < 0.008). MCSG was found to be of low alloantigenicity in that it did not induce second set rejection of subsequent skin allograft.

CONCLUSIONS

SN dressings enhanced survival of meshed composite skin grafts.

Prescribing patterns in primary health care in Taiwan

To identify the prescribing patterns in public group practice centers (GPCs), 84,453 prescription sheets written by primary care physicians in 168 GPCs during the period from December 7-12, 1992, were collected and analyzed. The average number of drugs per script was 4.3 and the ratio of drug to total medical expense was 44%. The 5 most common diagnoses were, in a descending order, upper respiratory tract infection, skeletomuscular and joint disease, hypertension, functional gastrointestinal disorder (including peptic ulcer) and diabetes mellitus. The top 5 most commonly dispensed drug categories were antacids and anti-ulcer drugs, anti-cough and anti-cold preparations, vitamins, simple analgesics and non-steroidal anti-inflammatory drugs, accounting for 48.8% of total prescriptions. In view of the frequency of relevant diagnoses, the overuse of antacids, vitamins, intravenous nutrient and electrolyte solutions, anti-cold preparations and antibiotics was apparent, as was that of drugs of questionable pharmacological value. These data indicate that polypharmacy is a widespread phenomenon and confirms our long-term concern over irrational drug use in GPCs in Taiwan. Both administrative and educational intervention should be implemented to improve prescribing quality at the primary health care level.

The knowledge and attitude of Hong Kong secondary school teachers and students towards HIV infection and dentistry

Although human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS) are firmly entrenched in Hong Kong no data are available on the knowledge and attitudes of Hong Kong secondary school teachers and teenage children towards this infection, and their perception of infection control measures currently undertaken by the dental profession to prevent such infectious diseases. Hence a postal questionnaire survey of a total of 2,886 teenagers and 372 school teachers of 21 secondary schools in Hong Kong was conducted. The questionnaire comprised a total of 13 questions divided into two categories; the first, aimed at assessing the respondents' general knowledge and attitudes towards AIDS, and the second related to AIDS, dentistry and infection control. More than half of the students and one quarter of the teachers surmised that HIV infection is equivalent to developing AIDS. Although the great majority of the respondents (85-97 per cent) were aware that HIV can not be transmitted through sharing combs and meals, one in two teachers and one in three students thought that the virus could be transmitted through saliva. A large majority of respondents believed television to be the most, and dentists the least, informative source on AIDS out of a list of eight options. Approximately one half of both groups were concerned about contracting HIV infection during dental treatment and 65 per cent of students and 57 per cent of teachers thought that dentists did not have sufficient knowledge to identify AIDS patients. Finally, more than three quarters of the respondents thought that it would be ill-advised to visit a dentist treating HIV-infected patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Human CC10 gene expression in airway epithelium and subchromosomal locus suggest linkage to airway disease

The CC10 gene encodes the Clara cell 10-kDa protein, which is expressed in airway epithelial cells. Quantification of CC10 gene expression in freshly isolated human proximal airway epithelial cells demonstrated very high mRNA levels, approximately fivefold greater than gamma-actin mRNA, and in situ hybridization localized CC10 mRNA to nonciliated airway epithelial cells. Sequence analysis demonstrated that the human CC10 gene is comprised of three short exons separated by a long first and short second intron, and with a 5' flanking region typical of a regulated gene. Three Alu repeats were observed in intron 1 and one in intron 2. Two polymorphic regions within the introns were identified. First, a microsatellite was localized 5' to the third Alu repeat in intron 1 with a variable number of 4- and 5-base pair (bp) repeats and a heterozygosity of 0.71. Second, in 3% of the 168 chromosomes examined, there was the insertion of a human-specific Alu repeat in intron 2, 45 bp 3' to the exon 2-intron junction. In three Centre d'Etude du Polymorphisme Humain families, meiotic breakpoint analysis using these two polymorphic loci localized the CC10 gene to 11 p12-q13 between markers D11S16 and D11S97, a region recently linked to atopy and to the beta-subunit of the high-affinity immunoglobulin E receptor. The observations in the present study of high-level expression of the CC10 gene in the epithelium of conducting airways and a subchromosomal localization of the gene to a region potentially linked to inflammatory airway disease, together with the reported anti-inflammatory and immune-modulating properties of the protein, suggest the CC10 gene product may be important in modulating inflammation within the airways. If so, the highly heterozygous microsatellite described in the present study should facilitate analysis of a possible linkage of the CC10 gene with an inherited susceptibility to asthma.

Gene therapy for the respiratory manifestations of cystic fibrosis

Cystic fibrosis (CF) is caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The major manifestations are on the airway epithelial surface, with purulent mucus, recurrent infections, chronic inflammation, and loss of lung function. Consequent to mutations in both parental genes, airway epithelial cells have insufficient CFTR function. Because this can be corrected in vitro by transfer of the normal CFTR gene into airway epithelial cells, it is reasonable to hypothesize that the respiratory manifestations of CF could be prevented by transfer of the normal human CFTR cDNA to the airway epithelium in vivo. Over the past 6 years, our laboratory has developed a strategy to accomplish this goal using a replication deficient E1-E3- recombinant adenovirus (Ad) serotype 5 vector containing the normal human CFTR cDNA (AdCFTR). Studies with experimental animals demonstrate that with administration of such a vector to the airways, the human CFTR cDNA could be transferred to the airway epithelium, with expression of the human CFTR cDNA for at least 6 weeks. Extensive preclinical studies in vitro and in vivo demonstrated that the risks to humans were sufficiently low to initiate a Phase I trial using the AdCFTR vector to treat the respiratory manifestations of CF in humans. Following approval by the National Heart, Lung, and Blood Institute Institutional Review Board, the National Institutes of Health Biosafety Committee, the National Institutes of Health Recombinant DNA Advisory Committee, and the Food and Drug Administration, we initiated the first human trial of gene therapy for CF on April 17, 1993. The clinical study is still ongoing, with safety and efficacy data being evaluated, but there is clear evidence that it is feasible to transfer and express the normal CFTR cDNA to the airway epithelium in vivo in individuals with CF.

Enhancer function of a 53-bp repetitive element in the 5' flanking region of the human neutrophil elastase gene

Expression of the human neutrophil elastase (NE) gene is limited to the early stage of myeloid cell differentiation in bone marrow cells. While NE gene expression is controlled mainly at the transcriptional level during bone marrow cell differentiation, the mechanism of transcriptional control is not fully understood. One motif of interest in the 5' flanking region of the gene is the six tandem repeats of a 53-bp nucleotide sequence (REP53) containing a potential binding site for a basic helix-loop-helix protein located at -1032 to -716. The REP53 sequence can function as a non-cell specific transcriptional enhancer which is capable of augmenting heterologous promoter activity. When the single REP53 element was inserted into the pAZ1037 chloramphenicol acetyltransferase (CAT) expression vector immediately upstream of the chicken beta-actin promoter in either normal or inverted orientation and used to transfect K-562 erythroleukemia or HeLa cervical carcinoma cells, these modified vectors achieved 2 to 3-fold higher CAT activity than the parental pAZ1037 vector irrespective of orientation of the REP53.

Cytomegalovirus-associated gastric ulcers in a normal host: a case report

Cytomegalovirus (CMV) is an ubiquitous organism, recognized as an important pathogen in patients from the neonatal period through adulthood. Although CMV infections in the gastrointestinal tract of immunocompromised individuals have been reported in increasing frequency in recent years, there have been only a few reports of CMV infections in the gastrointestinal tract of normal hosts. Here a 43-year-old female is described; she had had a four-month history of epigastric pain, and an upper gastrointestinal endoscopy revealed multiple gastric ulcers. Histologic examination of biopsies from the ulcers showed cytomegalovirus inclusion bodies. She had no detectable immunological abnormalities, blood transfusion or organ transplant history. Conventional antiulcer treatments achieved no response.

Evaluation of the respiratory epithelium of normals and individuals with cystic fibrosis for the presence of adenovirus E1a sequences relevant to the use of E1a- adenovirus vectors for gene therapy for the respiratory manifestations of cystic fibrosis

Lung disease associated with disorders such as cystic fibrosis (CF) may be amenable to somatic gene therapy in which there is delivery of the normal gene directly to the respiratory epithelium using E1a- adenovirus (Ad) type 2- or 5-based vectors. For safety reasons, the Ad vectors are rendered replication deficient by deletion of the E1a region. Because there is the theoretical possibility of an E1a- replication-deficient vector replicating as a result of recombination or complementation with Ad 2/5 E1a sequences present in the target cell, this study is directed toward evaluating respiratory epithelium of normals and individuals with CF for the presence of E1a sequences. Using Ad 2/5 E1a-specific primers and the polymerase chain reaction to evaluate DNA recovered from freshly isolated nasal and bronchial epithelium recovered by brushing, E1a sequences were detected in respiratory epithelium of 19 of 91 normals (21%). In the E1a-positive samples, the average of E1a copy number was 55 +/- 18/10(3) recovered cells. In CF individuals, 7 of 52 (13%) had detectable E1a sequences in the respiratory epithelium, with E1a copy number in the positive samples of 80 +/- 21/10(3) recovered cells. These results demonstrate that there are detectable Ad 2/5 E1a sequences in the respiratory epithelium of a small percentage of normals and individuals with CF. Because of the theoretical potential of such sequences supporting replication of E1a- Ad vectors, human gene therapy protocols for CF utilizing such vectors should consider evaluating study individuals for the presence of Ad 2/5 E1a sequences in the respiratory epithelium.

Administration of an adenovirus containing the human CFTR cDNA to the respiratory tract of individuals with cystic fibrosis

We have administered a recombinant adenovirus vector (AdCFTR) containing the normal human CFTR cDNA to the nasal and bronchial epithelium of four individuals with cystic fibrosis (CF). We show that this vector can express the CFTR cDNA in the CF respiratory epithelium in vivo. With doses up to 2 x 10(9) pfu, there was no recombination/complementation or shedding of the vector or rise of neutralizing antibody titres. At 2 x 10(9) pfu, a transient systemic and pulmonary syndrome was observed, possibly mediated by interleukin-6. Follow-up at 6-12 months demonstrated no long term adverse effects. Thus, it is feasible to use an adenovirus vector to transfer and express the CFTR cDNA in the respiratory epithelium of individuals with CF. Correction of the CF phenotype of the airway epithelium might be achieved with this strategy.

Modulation of secretory leukoprotease inhibitor gene expression in human bronchial epithelial cells by phorbol ester

Secretory leukoprotease inhibitor (SLPI), a 12-kD nonglycosylated serine antiprotease, helps to protect the epithelial surface of the airways from the destructive capacity of neutrophil elastase. Based on the recognition that SLPI levels can increase in the presence of airway inflammation, we hypothesized that inflammatory stimuli should modulate the expression of the SLPI gene in airway epithelial cells. To evaluate this, the modulation of SLPI gene expression with various inflammatory stimuli was evaluated in the HS-24 human bronchial epithelial cell line. After preliminary studies showed that several inflammatory mediators enhanced SLPI messenger RNA (mRNA) levels, PMA was used as a model inflammatory stimulus. PMA significantly increased the level of 0.7-kb SLPI mRNA transcripts in HS-24 cells in a dose- and time-dependent fashion and increased the amount of SLPI protein in the culture supernatant. Nuclear run-on analyses showed that the SLPI gene transcription rate increased approximately twofold after PMA stimulation. Transfection studies using fusion genes composed of fragments of up to 1.2 kb of the 5' flanking sequence of the SLPI gene and a luciferase reporter gene demonstrated potent promoter activity in the 131-bp segment (-115 to +16 relative to the transcription start site), and all longer segments up to 1.2 kb, whereas smaller segments showed low promoter activity. An 18-bp element (-98 to -115), in a region with homology to PMA-responsive regions in the Moloney murine leukemia virus enhancer and the IL-8 gene, was shown to be of importance in the level of transcription of the SLPI gene. However, this element was not responsible for the upregulation of SLPI gene expression by PMA. Evaluation of HS-24 cells in the presence of actinomycin D demonstrated that SLPI mRNA transcripts were very stable and became more so in the presence of PMA. Thus, SLPI gene expression in airway epithelial cells can be upregulated by an inflammatory stimulus, and this modulation is regulated at both the transcriptional and posttranscriptional levels. These mechanisms of SLPI upregulation likely play a role in defending the epithelial surface in the local milieu of inflammatory lung diseases.

Intraperitoneal in vivo gene therapy to deliver alpha 1-antitrypsin to the systemic circulation

The utility of replication-deficient recombinant adenovirus vector-mediated transfer and expression of the alpha 1-antitrypsin (alpha 1AT) cDNA to peritoneal mesothelial tissues was evaluated as a means of delivering alpha 1AT to the systemic circulation. Preliminary studies with Ad.RSV beta gal, an adenovirus vector expressing the Escherichia coli lacZ gene (beta-galactosidase), showed that intraperitoneal injection of 10(9) plaque-forming units (pfu) to cotton rats resulted in beta-galactosidase activity in mesothelial cells lining the peritoneal cavity. After intraperitoneal administration of 10(9) pfu of Ad alpha 1AT (an adenovirus vector containing the human alpha 1AT cDNA), human alpha 1AT was detectable in serum for up to 24 days, with a maximal level of 3.4 micrograms/ml at 4 days. Expression of the exogenous gene was localized to the peritoneal mesothelium as PCR analyses detected no evidence of expression of the exogenous gene in any other tissues evaluated. Anti-adenovirus vector antibodies were detectable in serum after intraperitoneal administration of the recombinant vectors, including antibodies with neutralizing activity. Repeat administrations of adenovirus vectors to the peritoneal cavity at 1 wk and 1 mo after the initial dose failed to show gene expression, but repeat administration 3 mo after demonstrated measurable gene transfer and expression. Together these observations suggest replication-deficient adenovirus-mediated gene transfer to the peritoneal mesothelium offers a promising means to transfer alpha 1AT to the systemic circulation, although immunity induced against the adenovirus may limit frequent repetitive dosing.

Gene transfer to freshly isolated human respiratory epithelial cells in vitro using a replication-deficient adenovirus containing the human cystic fibrosis transmembrane conductance regulator cDNA

Cystic fibrosis (CF) results from mutations of the CF transmembrane conductance regulator (CFTR) gene and subsequent defective regulation of cAMP-stimulated chloride (Cl-) permeability across the apical membrane of epithelial cells. In vitro transfer of normal CFTR cDNA corrects this defect, and studies in experimental animals have shown successful gene transfer to airway epithelium in vivo using a recombinant adenoviral vector containing the human CFTR cDNA (AdCFTR), supporting the feasibility of in vivo AdCFTR-mediated gene therapy for the respiratory manifestations of CF. One step in applying this therapy to CF patients is to evaluate the safety and efficacy of AdCFTR-mediated gene transfer in the actual target for human gene therapy, human airway epithelium. The present study demonstrates that AdCFTR restores cAMP-stimulated Cl- permeability in human CF bronchial epithelial cells. In addition, the study utilizes freshly isolated human airway epithelial cells from the nose and/or bronchi of normal individuals and/or individuals with CF to demonstrate that after in vitro AdCFTR-mediated gene transfer: (i) AdCFTR DNA does not replicate as a function of dose and time; (ii) CF epithelial cells express AdCFTR-mediated normal human CFTR mRNA; and (iii) CF epithelial cells, including terminally differentiated ciliated cells (the most common airway epithelial cell type), express the normal human CFTR protein. Together, these data support the use of AdCFTR in human gene therapy trials and suggest that biologic efficacy should be achievable in vivo.

Finite element analysis of cerebral contusion

Finite element analysis was carried out to study the mechanism of cerebral contusion. Clinical findings indicate that most cerebral contusions in the absence of skull fracture occur at the frontal and temporal lobes. To explain these observations, cavitation and shear strain theories have long been advocated. Plane strain finite element models of a parasagittal section of the human head were developed in the present study. The model was first validated against a set of experimental results from the literature. Frontal and occipital impacts were then simulated, and pressure and shear stress distributions in the brain were compared. While comparable negative pressures always developed in the contrecoup regions, shear stress distributions remained nearly identical regardless of the impact direction, consistent with the clinically observed pattern for contusion. Therefore, shear strain theory appears to account better for the clinical findings in cerebral contusion.

A mutation in CFTR produces different phenotypes depending on chromosomal background

Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene but the association between mutation (genotype) and disease presentation (phenotype) is not straightforward. We have been investigating whether variants in the CFTR gene that alter splicing efficiency of exon 9 can affect the phenotype produced by a mutation. A missense mutation, R117H, which has been observed in three phenotypes, was found to occur on two chromosome backgrounds with intron 8 variants that have profoundly different effects upon splicing efficiency. A close association is shown between chromosome background of the R117H mutation and phenotype. These findings demonstrate that the genetic context in which a mutation occurs can play a significant role in determining the type of illness produced.

In vivo antioxidant gene expression in human airway epithelium of normal individuals exposed to 100% O2

Human bronchial epithelium is exquisitely sensitive to high O2 levels, with tracheobronchitis usually developing after 12 h of exposure to 100% O2. To evaluate whether this vulnerability results from inability of the bronchial epithelium to provide adequate antioxidant protection, we quantified antioxidant gene expression in bronchial epithelium of normal volunteers at baseline and after exposure to 100% O2 in vivo. After 14.8 +/- 0.2 h of 100% O2, 24 of 33 individuals had evidence of tracheobronchitis. Baseline gene expression of CuZn superoxide dismutase (SOD), MnSOD, and catalase in bronchial epithelium was very low (CuZnSOD 4.1 +/- 0.8 transcripts/cell, MnSOD 5.1 +/- 0.9, catalase 1.3 +/- 0.2), with control gamma-actin expression relatively abundant (50 +/- 6 transcripts/cell). Importantly, despite 100% O2 exposure sufficient to cause tracheobronchitis in most individuals, antioxidant mRNA transcripts/cell in bronchial epithelium did not increase (P > 0.5). Catalase activity in bronchial epithelium did not change after exposure to hyperoxia (P > 0.05). Total SOD activity increased mildly (P < 0.01) but not sufficiently to protect the epithelium. Together, the very low levels of expression of intracellular antioxidant enzymes and the inability to upregulate expression at the mRNA level with oxidant stress likely have a role in human airway epithelium susceptibility to hyperoxia.

Genetic basis of variable exon 9 skipping in cystic fibrosis transmembrane conductance regulator mRNA

Variable in-frame skipping of exon 9 in cystic fibrosis transmembrane conductance regulator (CFTR) mRNA transcripts (exon 9-) occurs in the respiratory epithelium. To explore the genetic basis of this event, we evaluated respiratory epithelial cells and blood leukocytes from 124 individuals (38 with cystic fibrosis (CF), 86 without CF). We found an inverse relationship between the length of the polythymidine tract at the exon 9 splice branch/acceptor site and the proportion of exon 9- CFTR mRNA transcripts. These results strongly indicate a genetic basis in vivo modulating post-transcriptional processing of CFTR mRNA transcripts.

Alternative splicing of intron 23 of the human cystic fibrosis transmembrane conductance regulator gene resulting in a novel exon and transcript coding for a shortened intracytoplasmic C terminus

The cystic fibrosis transmembrane conductance regulator (CFTR) gene, the gene responsible for the lethal hereditary disorder cystic fibrosis, codes for a membrane protein functioning as a cAMP-regulated Cl- channel. Evaluation of human CFTR mRNA transcripts from epithelial and nonepithelial cells demonstrated a CFTR cDNA containing a 260-base pair (bp) insertion between the known CFTR exons 23 and 24, introducing a premature stop codon that would result in a CFTR protein shortened by 61 amino acids at the carboxyl terminus compared to that expected from the normal reported human CFTR coding sequences. Sequence analysis of intron 23 of the CFTR gene demonstrated that the 260-bp insertion (named exon 24a), a part of the reported intron 23 and located consecutive to exon 24, is likely generated by an alternative splice acceptor site. The exon 24a+ CFTR mRNA transcripts represented 3-16% of the total CFTR transcripts in epithelial and nonepithelial cells. These observations suggest an unexpected plasticity of expression of the CFTR gene, where alternative splicing of precursor CFTR mRNA transcripts permits the use of an alternative exon derived from a genomic segment previously believed to function as an intron.

Extensive posttranscriptional deletion of the coding sequences for part of nucleotide-binding fold 1 in respiratory epithelial mRNA transcripts of the cystic fibrosis transmembrane conductance regulator gene is not associated with the clinical manifestations of cystic fibrosis

Cystic fibrosis (CF) is a recessive hereditary disorder, requiring both parental cystic fibrosis conductance transmembrane regulator (CFTR) genes to carry mutations for clinical disease to manifest, i.e., only 50% of normal CFTR gene expression is required to maintain a normal phenotype. To help define the minimum amount of normal CFTR gene expression necessary to maintain normalcy, we have capitalized on our prior observation (Chu, C.-S., B. C. Trapnell, J. J. Murtagh, Jr., J. Moss, W. Dalemans, S. Jallat, A. Mercenier, A. Pavirani, J.-P. Lecocq, G. R. Cutting, et al. 1991. EMBO [Eur. Mol. Biol. Organ] J. 10:1355-1363) that normal individuals can have up to 66% of bronchial CFTR mRNA transcripts that are missing exon 9, a region representing 21% of the sequence coding for the critical nucleotide (ATP)-binding fold 1 (NBF1) of the predicted CFTR protein. The study population included 78 individuals with no prior diagnosis of CF. Evaluation of bronchial epithelial cells (obtained by bronchoscopy) revealed that exon 9 was variably deleted in all individuals. Remarkably, there were four individuals, all greater than or equal to 35 yr, in whom bronchial epithelial cells exhibited 73, 89, 90, and 92% CFTR transcripts with inframe deletion of exon 9, respectively, despite normal sweat Cl- and no clinical manifestation of CF. In the context that only 8% or less of bronchial CFTR transcripts need exon 9 to maintain normal airway function, these observations strongly suggest that either exon 9 is not necessary for CFTR structure and/or function or that only a very small fraction of bronchial epithelial cells need to express normal CFTR mRNA transcripts with exon 9 to perform the function of CFTR sufficient to maintain a normal phenotype in vivo.

Effects of posts on dentin stress distribution in pulpless teeth

A finite element analysis was carried out to study the roles of posts in reducing dentin stress in pulpless teeth. Two-dimensional plane strain models of the midlabiolingual section of a human maxillary central incisor were first analyzed. The results showed that the gold alloy post reduced maximal dentin stress by as much as 30%. However, the integrity of the dentin was compromised and the effects of the post were likely to be exaggerated in such models. In an effort to correct for these problems, plane stress models with side plates and axisymmetric models were analyzed. Posts were found to reduce maximal dentin stress by only 3% to 8% when the teeth were subjected to masticatory and traumatic loadings in these latter models. Although posts reduced maximal dentin stress by as much as 20% when the teeth were loaded vertically, teeth such as incisors and canines normally are not subjected to vertical loadings. Thus the reinforcement effects of posts seem to be doubtful in these teeth.

Down-regulation of cystic fibrosis transmembrane conductance regulator gene expression by agents that modulate intracellular divalent cations

In cystic fibrosis (CF), epithelial cells are unable to normally up-regulate apical membrane Cl- secretion in response to agents which increase cyclic AMP, but they do increase Cl- secretion in response to increases in intracellular Ca2+. Since intracellular divalent cations regulate the expression of many genes, we hypothesized that mobilization of intracellular Ca2+ and/or other divalent cations might modulate not only Ca(2+)-dependent Cl- channels but also cystic fibrosis transmembrane conductance regulator (CFTR) gene expression. To evaluate this concept, HT-29 human colon carcinoma cells were cultured under various conditions designed to manipulate intracellular divalent cation concentrations and CFTR gene expression was quantified at the levels of transcription, mRNA accumulation, mRNA half-life, and protein. Exposure to the divalent cation ionophores A23187 and ionomycin (agents which increase intracellular divalent cation concentrations) caused dose- and time-dependent reductions of CFTR mRNA levels, which could be blocked by the use of Ca(2+)- and Mg(2+)-free media. Ionophore-induced CFTR gene modulation was also observed with T84 human colon carcinoma cells and freshly isolated normal human bronchial epithelial cells. Incubation of HT-29 cells with thapsigargin, an agent that releases Ca2+ from intracellular stores, or in medium containing increased extracellular concentrations of Ca2+ or Mg2+ also caused down-regulation of CFTR mRNA levels. Transcription run-on analysis showed that, parallel with the decrease in CFTR mRNA levels, A23187 reduced the rate of transcription of the CFTR gene, while CFTR mRNA transcript half-life was unaffected. Consistent with the down-regulation of CFTR gene expression, CFTR protein levels also decreased after exposure to A23187. Thus, despite the independence of Ca(2+)-dependent Cl- channels and cyclic AMP-dependent CFTR-related Cl- channels in epithelial cells, increases in intracellular divalent cation concentrations down-regulate the expression of the CFTR gene at the transcriptional level, with consequent decreases in CFTR mRNA and protein.

Expression of the cystic fibrosis transmembrane conductance regulator gene in cells of non-epithelial origin

Consistent with the fact that the clinical disorder cystic fibrosis (CF) is manifested on epithelial surfaces, active transcription of the CF transmembrane conductance regulator (CFTR) gene and CFTR mRNA transcripts are detectable in a variety of epithelial cells, suggesting CFTR gene expression might be epithelial cell-specific. However, analysis of the CFTR gene promoter suggests it is a housekeeping gene, implying more widespread expression than only in epithelial cells. To evaluate the latter hypothesis, various human cells of non-epithelial origin, including lung fibroblasts, U-937 histiocytic lymphoma cells, K-562 erythroleukemia cells, HL-60 promyelocytic leukemia cells as well as freshly isolated blood lymphocytes, neutrophils, monocytes, and alveolar macrophages were examined for CFTR gene expression. Although Northern analysis failed to show CFTR mRNA transcripts in these cells, amplification of mRNA (after conversion to cDNA) by polymerase chain reaction combined with Southern analysis demonstrated the presence of CFTR mRNA transcripts at low levels in all cells evaluated except HL-60 cells. Comparative quantitative analysis showed fibroblasts contained 200-400 fold less CFTR mRNA transcripts than the T84 and HT-29 colon carcinoma epithelial cell lines, but had similar levels of CFTR transcripts to those of other epithelial cell lines. Nuclear transcription run-on analyses demonstrated very low level CFTR gene transcription in fibroblasts and U-937 cells, similar to that of other epithelial cells, but lower than the T84 and HT-29 colon carcinoma cell lines. Interestingly, while chromatin DNA of fibroblasts had no DNase I hypersensitivity sites in the 5' flanking region of the CFTR gene, HT-29 chromatin DNA exhibited four DNase I accessible sites in the same region, suggesting that these sites may be related to more active transcription of the CFTR gene in the intestinal epithelial cells than in fibroblasts.

Transdermal delivery of the alpha 2-agonist clonidine does not alter airways responses to inhaled histamine or methacholine

Previous studies have reported that the inhalation of the alpha 2-agonist clonidine decreases airways reactivity. Other studies have shown that oral doses of clonidine acutely increase airways reactivity to histamine, but not to methacholine. Recently, a transdermal clonidine delivery system (TTS) has been approved for use, and there is an increasing interest in using this system for management of postmenopausal and smoking cessation symptoms. To our knowledge, the effects of TTS on airways function in asthmatics have not been reported. The purpose of this study was to determine if use of TTS would alter airways reactivity. Six asymptomatic asthmatic subjects underwent a baseline methacholine challenge (M). In a double-blinded randomized crossover fashion, either a placebo or a TTS patch (TTS-1, 0.1 mg/day), was applied to the arm. Four days later, the challenge was repeated. After two to three days of washout, the alternate patch was applied, and a second challenge was performed. Several days later, a second baseline challenge was repeated. This sequence was then repeated using histamine (H). The patch was well tolerated by all subjects. There was no significant change in resting pulse or blood pressure, and for the group no change in airways reactivity to either M or H was noted. In conclusion, while use of TTS-1 does not improve airways function, its short-term use in asthmatics is not associated with an increase in airways reactivity.

Expression of the cystic fibrosis transmembrane conductance regulator gene in the respiratory tract of normal individuals and individuals with cystic fibrosis

The most common mutation of the cystic fibrosis transmembrane conductance regulator gene, CFTR, associated with the clinical disorder cystic fibrosis (CF) is called "delta Phe508," a triple-base deletion resulting in loss of phenylalanine at residue 508 of the predicted 1480-amino acid CFTR protein. In the context that the lung is the major site of morbidity and mortality in CF, we evaluated airway epithelial cells for CFTR mRNA transcripts in normal individuals, normal-delta Phe508 heterozygotes, and delta Phe508 homozygotes to determine if the normal and delta Phe508 CFTR alleles are expressed in the respiratory epithelium, to what extent they are expressed, and whether there are relative differences in the expression of the normal and abnormal alleles at the mRNA level. Respiratory tract epithelial cells recovered by fiberoptic bronchoscopy with a cytology brush demonstrated CFTR mRNA transcripts with sequences appropriately reflecting the normal and delta Phe508 CFTR alleles of the various study groups. CFTR gene expression quantified by limited polymerase chain reaction amplification showed that in normal individuals, CFTR mRNA transcripts are expressed in nasal, tracheal, and bronchial epithelial cells at approximately 1-2 copies per cell, more than 100-fold greater than in pharyngeal epithelium. Importantly, allele-specific hybridization studies demonstrated that the normal and delta Phe508 CFTR alleles are expressed in the respiratory epithelium in similar amounts.

Weak direct current accelerates split-thickness graft healing on tangentially excised second-degree burns

We have examined the effects of direct current (DC) conducted through silver-nylon dressings on the healing time and morphologic maturation of split-thickness grafts placed on tangentially excised deep partial-thickness burn wounds. Male guinea pigs (n = 120) were used as the experimental hosts. The DC-treated animals required 2 days for complete revascularization of their grafts; control animals required 7 days (p less than 0.01). The DC-treated animals had increased epithelial proliferation at the graft-wound interface as compared with controls (p less than 0.01). Grafts from DC-treated animals were firmly adherent within 4 days, whereas graft adherence in controls was weak before 7 days after grafting. At 3 months after grafting, control animal grafts had mild contraction with moderate hair loss and thick subepidermal fibrosis; the grafts in DC-treated animals expanded with the growth of the animals and had abundant hair growth and significantly reduced dermal fibrosis (p less than 0.01).

Down-regulation of cystic fibrosis gene mRNA transcript levels and induction of the cystic fibrosis chloride secretory phenotype in epithelial cells by phorbol ester

To evaluate the hypothesis that phorbol myristate acetate (PMA) might modulate the expression of the cystic fibrosis (CF) gene in epithelial cells, we examined the effect of PMA on CF mRNA levels and regulation of Cl- secretion. Strikingly, PMA down-regulated CF mRNA transcript numbers in a dose- and time-dependent manner. Importantly, in parallel with the reduction of CF mRNA levels, PMA-treated cells were unable to up-regulate Cl- secretion in a normal fashion in response to forskolin, an effect which was also dose- and time-dependent. Thus, PMA is capable of modulating expression of the CF gene and induces T84 cells to adopt the "CF phenotype" in regard to regulation of Cl- ion transport.

Variable deletion of exon 9 coding sequences in cystic fibrosis transmembrane conductance regulator gene mRNA transcripts in normal bronchial epithelium

The predicted protein domains coded by exons 9-12 and 19-23 of the 27 exon cystic fibrosis transmembrane conductance regulator (CFTR) gene contain two putative nucleotide-binding fold regions. Analysis of CFTR mRNA transcripts in freshly isolated bronchial epithelium from 12 normal adult individuals demonstrated that all had some CFTR mRNA transcripts with exon 9 completely deleted (exon 9- mRNA transcripts). In most (9 of 12), the exon 9- transcripts represented less than or equal to 25% of the total CFTR transcripts. However, in three individuals, the exon 9- transcripts were more abundant, comprising 39, 62 and 66% of all CFTR transcripts. Re-evaluation of the same individuals 2-4 months later showed the same proportions of exon 9- transcripts. Of the 24 CFTR alleles in the 12 individuals, the sequences of the exon-intron junctions relevant to exon 9 deletion (exon 8-intron 8, intron 8-exon 9, exon 9-intron 9, and intron 9-exon 10) were identical except for the intron 8-exon 9 region sequences. Several individuals had varying lengths of a TG repeat in the region between splice branch and splice acceptor consensus sites. Interestingly, one allele in each of the two individuals with 62 and 66% exon 9- transcripts had a TT deletion in the splice acceptor site for exon 9. These observations suggest either the unlikely possibility that sequences in exon 9 are not critical for the functioning of the CFTR or that only a minority of the CFTR mRNA transcripts need to contain exon 9 sequences to produce sufficient amounts of a normal CFTR to maintain a normal clinical phenotype.