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Eravacycline is the newest member of the broad-spectrum class of tetracycline antimicrobials. Pancreatitis has been previously associated with the tetracycline class of antibiotics, but, to our knowledge, we believe that this is the first reported case of eravacycline-induced pancreatitis. We describe a 46-year-old male who received eravacycline for treatment of a perirectal abscess. While the patient had slightly elevated lipase levels at baseline post-cardiopulmonary arrest, he developed abdominal pain and a further increase in lipase levels following 10 days of eravacycline, consistent with pancreatitis. Based on the Naranjo adverse drug reaction probability scale, eravacycline was the probable etiology of acute pancreatitis given improvement immediately after discontinuation. Clinicians should be aware of this potential adverse effect of eravacycline and should not initiate eravacycline in those with risk factors for acute pancreatic injury. However, acute pancreatitis should be suspected in all patients complaining of symptoms followed by immediate discontinuation of eravacycline., Competing Interests: Declaration of Competing Interest The author has no financial or other conflicts of interest to disclose., (Copyright © 2023 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.)

Microbial symbiosis is essential for the normal development and growth of hosts. Past attention has mostly been paid to its effects on plants and vertebrates. The effects of environmental pressures such as antibiotics on the microbiome of soil fauna remain largely elusive. We used bacterial 16S rRNA gene high-throughput sequencing to examine the response of microbiome of soil invertebrate Enchytraeus crypticus to oral tetracycline exposure. After two-week exposure, tetracycline-free oat was used as food to monitor the restoration of E. crypticus microbiome. The results showed that Proteobacteria, Actinobacteria and Planctomycetes were the three dominant phyla in all samples, Rhizobiaceae and Kaistia were the most abundant family and genus in all samples, respectively. After 14 days tetracycline exposure, Planctomycetes declined dramatically from 33.05% to 3.28% (P = 0.016), but Actinobacteria elevated substantially from 2.47% to 23.65% (P = 0.004). The alpha-diversity of microbial community increased significantly after tetracycline exposure compared to the control (P = 0.014). Terminating tetracycline exposure led to the recovery of E. crypticus microbiome back to the background level within 14 days. Our results suggest that while tetracycline can disturb the microbiome in E. crypticus significantly, the effects of the antibiotic on E. crypticus microbiome may not be permanent but reversibly diminish after stopping exposure for a period of time. The results may contribute to extending our understanding of the effect of antibiotics on microbiome of soil invertebrates. CAPSULE: The microbiome of E. crypticus exposed to tetracycline is perturbed and reversibly restored after terminating the exposure., (Copyright © 2018. Published by Elsevier B.V.)

Background: Helicobacter pylori is associated with benign and malignant diseases of the upper gastrointestinal tract, and increasing antibiotic resistance has made alternative treatments necessary. Our aim was to assess the efficacy and safety of a new, single-capsule treatment versus the gold standard for H pylori eradication., Methods: We did a randomised, open-label, non-inferiority, phase 3 trial in 39 sites in Europe, comparing the efficacy and safety of 10 days of quadruple therapy with omeprazole plus a single three-in-one capsule containing bismuth subcitrate potassium, metronidazole, and tetracycline (quadruple therapy) versus 7 days of omeprazole, amoxicillin, and clarithromycin (standard therapy) in adults with recorded H pylori infection. Patients were randomly assigned treatment according to a predetermined list independently generated by Quintiles Canada (Ville St-Laurent, QC, Canada). Our study was designed as a non-inferiority trial but was powered to detect superiority. Our primary outcome was H pylori eradication, established by two negative (13)C urea breath tests at a minimum of 28 and 56 days after the end of treatment. Our assessment for non-inferiority was in the per-protocol population, with subsequent assessment for superiority in the intention-to-treat population (ie, all participants randomly assigned treatment). This study is registered with ClinicalTrials.gov, number NCT00669955., Findings: 12 participants were lost to follow-up and 101 were excluded from the per-protocol analysis. In the per-protocol population (n=339), the lower bound of the CI for treatment with quadruple therapy was greater than the pre-established non-inferiority margin of -10% (95% CI 15·1-32·3; p<0·0001). In the intention-to-treat population (n=440), eradication rates were 80% (174 of 218 participants) in the quadruple therapy group versus 55% (123 of 222) in the standard therapy group (p<0·0001). Safety profiles for both treatments were similar; main adverse events were gastrointestinal and CNS disorders., Interpretation: Quadruple therapy should be considered for first-line treatment in view of the rising prevalence of clarithromycin-resistant H pylori, especially since quadruple therapy provides superior eradication with similar safety and tolerability to standard therapy., Funding: Axcan Pharma Inc., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Background: Although porcelain veneer has been proposed as the treatment of choice in cases of severe tooth discoloration, clinicians should consider a multidisciplinary approach when treating complex cases. Clinicians also need to understand the masking ability of veneer restorations., Case Description: A 20-year-old woman had severe tooth discoloration, enamel hypoplasia and malocclusion. The patient first underwent orthodontic treatment to correct the dental alignment after the author extracted her hypoplastic first molars. The author then placed porcelain veneers with high-density alumina cores on the patient's maxillary and mandibular anterior teeth. The restorations were in service for seven years without complications., Conclusions: and, Clinical Implications: Managing severe tooth discoloration requires thorough consideration of all patient factors, treatment provided in a logical sequence and the use of porcelain veneers with adequate masking ability.

Background: Tetracyclines are broad-spectrum antibiotics used by dental practitioners in the treatment of periodontal disease. They generally are safe in adults. However, caution is advised in patients who have pre-existing kidney disease., Case Description: A 42-year-old woman with polycystic kidney disease received a prescription for tetracycline (250 milligrams, four times daily) after undergoing tooth extractions. She developed nausea, vomiting and diarrhea within days and end-stage renal disease within two weeks of taking the antibiotic. Hemodialysis was required to stabilize the patient's condition. Use of the Naranjo nomogram demonstrated an association between the two events., Clinical Implications: This case illustrates the importance of obtaining a thorough medical history and understanding potential adverse drug effects before prescribing a common antibiotic.

Objective: Carbamide peroxide and hydrogen peroxide have been used as tooth whitening agents. The aim of this paper was to determine the efficiency of several enzyme-containing whitening systems. A method to determine the rate of 'in vitro' tetracycline whitening was also developed., Methods: We determined the tetracycline whitening ability of carbamide peroxide and hydrogen peroxide, and the influence of peroxidase and lactoperoxidase on this tetracycline whitening rate., Results: High peroxidase and lactoperoxidase concentrations increased the rate of tetracycline decoloration obtained with carbamide peroxide or hydrogen peroxide. The decoloration rate observed was lower when the glucose/glucose oxidase system was used to generate hydrogen peroxide 'in situ'. The presence of peroxidase increased the decoloration rate of extracted teeth obtained with carbamide., Conclusions: Enzymes such as peroxidase could be used as whitening catalysts to increase the rate of tetracycline decoloration.

The aim of this study was to determine the extent of calcium removal on root canal dentin after 17% EDTA, 17% EGTA, 15% EDTAC, and 1% tetracycline-HCl treatment; with or without subsequent use of 2.5% NaOCl. Extracted single-rooted human teeth were bisected longitudinally and the root halves (n=100) were isolated with nail varnish, leaving the root canal exposed. The samples were immersed in the test solutions for 1 and 5 minutes, after which the amount of calcium ion (Ca(2+)) release into the solutions was determined by flame photometry. Regardless of treatment time, all single (treatment solution only) and combined (treatment solution with subsequent NaOCl application) irrigation regimens removed significantly more Ca(2+) than control treatment (distilled water). Compared with other groups, treatment with 17% EDTA and 17% EDTA + 2.5% NaOCl resulted in the maximum amount of Ca(2+) removal from root canal dentin (p<0.05). All combined-treatment groups except 17% EGTA + 2.5% NaOCl removed significantly more Ca(2+) than their single-treatment versions (p<0.05). Within each test group, extending the treatment time to 5 minutes resulted in significantly more Ca(2+) removal (p<0.05).

Objective: To systematically review the scientific evidence derived from randomized controlled trials (RCT) about prevention of alveolar osteitis (AO)., Study Design: Literature searches were conducted to locate RCTs about prevention of AO. The RCTs were scrutinized for methodological details and categorized according to the preventive intervention studied. Data were analyzed in relation to the frequency of AO. Absolute risk reductions (ARR), and numbers needed to treat were calculated with 95% confidence limits., Results: There was a wide variation in the design and quality of the RCTs (N = 32). The greatest risk reduction for AO was seen for local treatment with tetracycline (ARR, 12%-31%). For a majority of the preventive interventions, the evidence was absent or inconclusive., Conclusions: Local treatment with tetracycline, and also 0.12% chlorhexidine rinsing preoperatively and 7 days postoperatively, seem to have significant and clinically relevant preventive effect on AO following surgical removal of lower third molars.

Background: Root resorption and ankylosis have been reported rarely as sequelae to guided tissue regeneration (GTR). The authors describe a clinical case of root resorption following GTR that involved the use of a bioabsorbable membrane., Case Description: Two years after GTR was performed on a Class II furcation defect, the clinical examination revealed root resorption reaching the pulp chamber. The furcation defect was filled with epithelium and connective tissue, which contained inflammatory infiltrate and fragments of the membrane. The authors also observed areas of the tooth that exhibited points of ankylosis and root resorption., Clinical Implications: Clinical trials have reported favorable clinical and histologic results with GTR. However, this case report, along with other case reports and studies in animals, suggests a high risk of root resorption and ankylosis after GTR, which could limit the indications for this technique.

Objective: The purpose of this study was to evaluate the clinical result of 546 tetracycline-stained teeth restored with a porcelain laminate veneer system (Cerinate, Den-Mat, USA) for aesthetic reasons., Methods: Tetracycline-stained teeth (546) were restored with a porcelain veneer system, and bonded with Ultra Bond resin cement. The restorations were recalled after 0.5, 1.5 and 2.5 years, respectively. Modified Ryge criteria were used to evaluate the veneers marginal adaptation, interfacial staining, secondary caries, postoperative sensitivity and the patients' satisfaction of the colour of the restorations., Results: This study found that 99% veneers had excellent marginal adaptations; and less than 1% veneers required rebonding in the first 6 months; the colour of the veneers was stable and no evident staining was found. Almost all patients were satisfied with the colour match of their restorations 1 year after placement., Conclusions: The research indicated that the porcelain veneer restoration system under investigation provided a reliable and highly satisfactory choice for the aesthetic restoration of tetracycline-stained teeth.

Background: Quadruple therapy provided inadequate eradication rate when given twice-a-day at breakfast and evening meals., Aim: To test twice daily (mid-day and evening) quadruple therapy for Helicobacter pylori eradication., Methods: This was a single-centre pilot study in which H. pylori-infected (positive histology and culture and RUT) patients were given 2 x 250 mg of metronidazole and 2 x 250 mg of tetracycline, two Pepto-Bismol tablets, plus one 20 mg rabeprazole tablet twice-a-day for 14 days. H. pylori status was confirmed 4 or more weeks after the end of therapy., Results: Thirty-seven patients including 3 with peptic ulcer disease, 19 asymptomatic infected, 4 GERD, and 11 with NUD. Mid-day quadruple therapy was successful in 92.3% (95% CI: 79-98%) including 96.2% of those with metronidazole-susceptible strains, and in 83.3% (10/12) of those with metronidazole-resistant H. pylori. Compliance was 100% by pill count except in one individual who stopped medication after 12 days because of side-effects and who failed therapy. Moderate or greater side-effects were experienced by five patients., Conclusion: Twice-a-day, mid-day, quadruple therapy proved effective using the combination of bismuth subsalicylate and rabeprazole instead of bismuth subcitrate and omeprazole. Detailed studies of different formulations (e.g. 2 x 250 mg versus 1 x 500 mg of metronidazole or tetracycline) and timing of administration (breakfast and evening meal versus mid-day and evening meals) may result in significant improvements in H. pylori eradication regimens.

Background: Pleurodesis is important in the management of malignant pleural effusions, but no consensus exists on the optimal agent or methods of pleurodesis. How pleurodesis is practiced worldwide has not been studied., Objectives: To identify variations in the clinical practice of pleurodesis in major English-speaking countries, and to quantify the experience of pulmonologists on the effectiveness and adverse effects of different pleurodesis agents worldwide., Methods: Eight hundred fifty-nine pulmonologists practicing in the United States, United Kingdom, Canada, Australia, and New Zealand participated in a Web-based survey., Results: The respondents collectively perform > 8,300 pleurodesis annually. Talc was the preferred agent by most respondents (slurry, 56%; poudrage, 12%), followed by tetracycline derivatives (26%), and bleomycin (7%). Differences were seen in pleurodesis practice patterns among practitioners among and within the surveyed countries. Physicians' overall satisfaction with the available pleurodesis agents was modest (5.0 out of 8), and the reported success rate averaged only 66%. Talc (both poudrage and slurry) was perceived as significantly more effective, but was associated with significantly more pain, nausea, and fever (p < 0.05). Respiratory failure occurred more commonly with talc poudrage than with other agents (p < 0.05), and had been observed by 70% and 54% of physicians who used talc poudrage and slurry, respectively., Conclusions: Significant variations exist in how pleurodesis is performed worldwide. Pleurodesis agents currently available are perceived as suboptimal. Talc poudrage and slurry were perceived to be more effective, but were associated with more complications, including respiratory failure.

Eradication of Helicobacter pylori from the stomach by triple therapy with bismuth, tetracycline, and metronidazole cures peptic ulcer disease. We investigated whether concomitant acid inhibition with omeprazole would improve the results of triple therapy. 108 consecutive patients with peptic-ulcer disease and biopsy-proven H pylori infection were randomised to 7 days of triple therapy with or without omeprazole 20 mg twice daily. Patients in the omeprazole-treated group were pretreated with 3 days of omeprazole. Eradication of H pylori was assessed by 10 endoscopic biopsies for urease test, histology, and culture 4-6 weeks after treatment. 53 of 54 (98.1%) patients treated with omeprazole were cured compared with 45 of 54 (83.3%) of those not treated (p = 0.02), a difference in efficacy of 14.8% (95% Cl 4.2-25.4%). Most side effects were mild and did not interfere with compliance; 105 patients (97.2%) finished treatment. Gastro-intestinal side effects were significantly fewer in the omeprazole group. We conclude that the addition of omeprazole to triple therapy improves efficacy, lessens side effects, and is sufficiently efficacious to obviate the need for a diagnostic test of cure in compliant patients.

In this clinical trial of nightguard vital bleaching for six weeks, 92 percent of the patients experienced some lightening of treated teeth. About 97 percent of patients with teeth stained through aging, inherent discoloration, brown fluorosis or trauma experienced lightening, as did 75 percent with tetracycline-stained teeth. Sixty-six percent experienced side effects, which resolved in 24 to 48 hours. Earliest re-treatment was done after one year in less time. Minimal color change occurred for 74 percent after 1 1/2 years and 62 percent after three years.

Parenteral tetracycline, one of the most commonly used agents for producing pleurodesis, is no longer available because of stricter regulations governing the manufacturing process. The objective of this project was to determine whether minocycline, a tetracycline derivative, is an effective sclerosant in an experimental model in rabbits. We also studied the relationship of the dose and the volume injected to the degree of pleurodesis. The following medications were instilled intrapleurally in anesthetized male rabbits: tetracycline, 35 mg/kg; or minocycline, 4, 7, 10, or 20 mg/kg, diluted to a total volume of 1 or 2 ml of bacteriostatic saline solution; or minocycline, 40 mg/kg, diluted to a total volume of 2 ml of the solution. Twenty-eight days after the instillation, the animals were killed. The pleural spaces were assessed grossly for evidence of pleurodesis and microscopically for evidence of fibrosis and inflammation. The degree of pleurodesis grossly and microscopically after the injection of 7, 10, 20, or 40 mg/kg of minocycline was comparable to that after the injection of 35 mg/kg of tetracycline, while the dose of 4 mg/kg was less effective. In the animals who received the higher doses of minocycline intrapleurally (ie > or = 20 mg/kg), there was an excess mortality both early (chi 2 = 3.61, 0.05 < p < 0.10) and late (chi 2 = 11.0, p < 0.005) which appeared to be related to the development of hemothorax. The intrapleural injection of the tetracycline derivatives was significantly (p < 0.05) more effective when the total volume of the solution was 2 ml rather than 1 ml. The present study demonstrates that minocycline is an effective agent for producing pleurodesis in the rabbit. Minocycline given intrapleurally at doses of 7 mg/kg or above is comparable to tetracycline, 35 mg/kg. Higher doses of minocycline (> or = 20 mg/kg) produce a high mortality that seems to be related to hemothorax. Since, in humans, a large experience confirms only 20 mg/kg of tetracycline is needed to produce adequate pleurodesis safely, we recommend a dose of 4 mg/kg of minocycline for the production of pleurodesis.

Chemical pleurodesis is a frequently performed procedure for pneumothorax and effusion and significant adverse effects are unusual. We present a previously unreported case of acute renal failure associated with tetracycline pleurodesis. Recent studies have shown that intrapleural drug administration may lead to therapeutic serum levels. Systemic toxic drug effects may therefore be noted with chemical pleurodesants such as tetracycline. Alternative methods of pleurodesis should always be considered if a sensitivity or metabolic abnormality is suspected.

Blindness due to trachoma is a serious public health issue world wide. The currently recommended treatment of active trachoma with repeated doses of tetracycline eye ointment has many disadvantages. The new azalide antibiotic azithromycin is effective as a single oral dose in the chemotherapy of genital Chlamydia trachomatis infections, and we have assessed its efficacy for trachoma treatment. We carried out a randomised single-blind comparison of azithromycin (a single oral dose of 20 mg/kg) with conventional treatment (6 weeks of topical tetracycline plus erythromycin for severe cases) in two villages with endemic trachoma in The Gambia. The patients were followed up for 26 weeks from the start of treatment by an observer unaware of treatment allocation. By 6 months' follow-up, trachoma had resolved in 76 (78%) of 97 subjects who received azithromycin compared with 70 (72%) of 97 who were treated conventionally (95% CI for difference -6% to 18%). Compliance with both treatments was good, but that for conventional treatment could probably not be achieved outside the research setting. There were no significant differences in treatment effect, baseline characteristics, or re-emergent disease between the treatment groups. Azithromycin was well tolerated. As a systemic treatment effective in a single dose it has important potential for trachoma control.

Intrathoracic extramedullary hematopoiesis rarely involves the pleura and is usually asymptomatic. We report a 73-year-old woman with myelofibrosis who had pleural involvement with extramedullary hematopoietic tissue that produced a massive hemothorax. Before the diagnosis of extramedullary hematopoietic tissue was established, sclerosis with tetracycline was attempted, which accelerated pleural bleeding and required surgical evacuation. The bleeding was ultimately controlled by low-dose radiation therapy.

We have adapted the neutral red uptake assay for quantitative assessment of injury to fibroblast cultures by potential phototoxins. Tetracycline derivatives, quinolone derivatives, and chlorpromazine were used as model compounds for development of the assay. Human fibroblasts were incubated with potential phototoxins, the cell cultures irradiated with UV, and the capacity for neutral red uptake determined. Demeclocycline and doxycycline, two known photosensitizers, showed a 94% and 95% decrease of neutral red uptake, respectively, indicating photo-induced cytotoxicity. Minocycline, a non-photosensitizing tetracycline derivative, showed no decrease in uptake. Tetracycline, a weak phototoxin, showed minor (10%) decrease at equivalent concentrations (20 micrograms/ml). Microscopic observation of neutral red uptake and cell damage paralleled the spectrophotometric findings. Chlorpromazine, a non-tetracycline phototoxin, showed 91% decrease. An additional group of phototoxic drugs, quinolone antibacterials, were studied. Nalidixic acid, ofloxacin, ciprofloxacin, and norfloxacin all demonstrated phototoxicity, with nalidixic acid showing the greatest decrease in neutral red uptake. This methodology may provide a useful rapid method to quantify phototoxic potential of new drugs or suspected phototoxins.

Between December 1985 and August 1988, there were 115 patients at 13 centers who were entered on a randomized comparison of tetracycline and bleomycin for treatment of malignant pleural effusions. Fifteen patients were not treated, primarily due to rapid progression of systemic cancer. Fifteen patients entered on a high-dose regimen of bleomycin (120 units) were excluded from this analysis (following early closure of that arm), leaving 85 patients randomized to low-dose bleomycin (60 units; 44 patients) or tetracycline (1 g; 41 patients). Patients were required to have a cytologically positive pleural effusion, good performance status (0, 1, or 2), lung reexpansion following tube thoracostomy with drainage rates of 100 ml/24 or less, no prior intrapleural therapy, no prior systemic bleomycin therapy, no chest irradiation, and no recent (four weeks) change in systemic therapy. A total of 11 patients (five with bleomycin and six with tetracycline) were not evaluable due to technical problems with tube drainage (one), loss to follow-up (two), sudden death due to pulmonary embolus (one), and rapid progression of systemic disease (seven). There were no clinically significant differences in demographic factors, primary site, performance status, or presence of metastases other than pleural effusion. Overall survival did not differ between the two groups. Median time to recurrence or progression of the effusion was 32 days for tetracycline-treated patients and at least 46 days for bleomycin-treated patients (p = 0.037). The recurrence rate within 30 days of instillation was 36 percent (10/28) with bleomycin and 67 percent (18/27) with tetracycline (p = 0.023) (not all patients were restudied in the first 30 days). By 90 days the corresponding recurrence rates were 30 percent (11/37) for bleomycin and 53 percent (19/36) for tetracycline (p = 0.047). Toxicity was similar between groups.

Myospherulosis is a complication of wound healing which results from an action between lipids and extravasated erythrocytes. A case of myospherulosis of the mandible is reviewed with its history, histopathology and occurrence.

For many years, tetracycline has been prescribed in the treatment of periodontal disease with little research data supporting such use. Current data suggest that most patients with periodontal disease are best treated by conventional techniques of subgingival debridement.

A case of an 18-year-old woman with postoperative infectious complications and multiple antibiotic allergies is discussed. The case poses several problems: the selection of an appropriate antibiotic to combat the infection, the persistence of the infection, and the treatment of multiple allergic responses to each of the antibiotic agents chosen.

Recent evidence shows tetracyclines have anticollagenolytic activity that may be clinically effective in disease treatment. This led us to use systemic tetracycline (oral tetracycline hydrochloride 1 g daily divided into 4 doses) as adjunctive therapy in treating 18 patients with persistent corneal epithelial defects. Fourteen of 18 patients healed their defects; within 48 hours (9 patients) and within two weeks (the other 5 responding patients). Two patients showed no effect and two showed disease progression.

Adverse reactions to derivatives of theophylline were studied among 2,766 medical inpatients. The primary diagnosis at discharge was cardiac disease in 23 percent, chronic obstructive pulmonary disease in 22 percent, asthma in 13 percent, pulmonary infection in 10 percent, and other disorders in 3 percent of the patients. Eight hundred seven of the patients were current cigarette smokers, and 1,209 denied smoking. Adverse effects of administration of theophylline were reported in 298 patients (10.8 percent). Gastrointestinal disturbances, reported in 7.8 percent of the recipients, were the most common adverse effects. Others were cardiovascular disturbances (1.2 percent), effects on the central nervous system (0.9 percent), and miscellaneous adverse reactions (0.9 percent). A higher frequency of adverse reactions was associated with higher doses of theophylline; however, cigarette smoking was negatively correlated with the frequency of adverse reactions. Adverse effects were experienced by 13 percent of the nonsmokers, by 11 percent of those who smoked up to 20 cigarettes daily, and by 7 percent of those who smoked more heavily. This association was most apparent among young patients with normal renal function and was least evident among the elderly.

A descriptive epidemiologic study was undertaken to determine the nature, extent, and severity of defects of the dentition alleged to be fluorosis in Native American children. An examination of 520 Native American children living on the St. Regis Reservation, and 248 non-Native American children living in adjacent areas, disclosed a much higher prevalence of generalized pigmentation of the dentition in the former (114, 22%) as compared with the latter group (13, 5.2%). The pattern of enamel pigmentation, opacity, and hypoplasia observed was not typical of fluorosis. After careful consideration of various etiologic factors, use of the antibiotic tetracycline was determined to be the probable causative agent in 112 (21.5%) cases, of which 73 (14%) were classified as esthetically objectionable according to the tetracycline severity index devised. Confirmation of incorporation of the drug into the teeth was made possible in selected cases by histopathologic analysis of extracted teeth.

A 26-year-old man had been treated for acne vulgaris with tetracycline and minocycline orally for 12 years. He developed dark brown to black pigmentary deposits in the palpebral conjunctiva bilaterally. These deposits resembled those seen in epinephrine pigmentation of the conjunctiva. Histologically the pigmented deposits were concretions in conjunctival cysts. Although they contained calcium, the concretions displayed the characteristic yellow autofluorescence of tetracycline under ultraviolet light. Presumably, tetracycline had formed extracellular chelation complexes with calcium, thus accounting for the pigmentation of the conjunctiva.

Naloxone, an opioid antagonist, and meptazinol, an opioid antagonist with agonist properties, were tested in a double-blind placebo-controlled trial in 24 Ethiopian patients with louse-borne relapsing fever. The potentially fatal Jarisch-Herxheimer reaction (J-HR), which invariably follows tetracycline treatment of the disease, was unaffected by naloxone, 30-40 mg intravenously, but was diminished by meptazinol, 300-500 mg intravenously. Compared with naloxone and placebo, meptazinol reduced the clinical severity of the reaction, significantly delayed and shortened its chill phase, delayed the rise in temperature, and reduced peak temperature and changes in pulse and respiratory rates and leucocyte count. High-dose corticosteroids given before or at the time of tetracycline treatment failed to alter the reaction, which is thought to result from release of endotoxin-like substances. Meptazinol is the first effective treatment for the J-HR of louse-borne relapsing fever. This finding suggests a role for endogenous opioids in the pathogenesis of the J-HR.

Today, bleaching alone can be effective in restoring appearance to teeth stained from various causes. Moreover, bleaching can be combined with other restorative treatment to produce results not otherwise possible. Bleaching requires careful diagnosis and techniques but offers a relatively simple, safe, and successful way to significantly improve appearance. In the future, bleaching will be a routine, conservative treatment option.

Unpigmented and pigmented cystic epithelial inclusions were found bilaterally within the lower palpebral conjunctiva temporally of a 31-year-old man. He had a history of tetracycline/minocycline therapy for 14 years because of acne vulgaris. The cysts were studied by light and electron microscopy, histochemistry, and ultraviolet light. By light microscopy the unpigmented cysts contained faintly eosinophilic globular material that disclosed yellowish-green autofluorescence indicating the presence of tetracycline/minocycline. The pigmented cysts revealed laminated eosinophilic to brownish concretions that also showed yellowish-green autofluorescence. Autofluorescence, however, decreased with increasing brown pigmentation of the concretions. Histochemically, the pigment, which failed to show the staining characteristics of lipofuscin, melanin or iron, probably represented an oxidation product of tetracycline. By electron microscopy the cysts contained moderately electron dense amorphous material as well as degenerating epithelial cells. The epithelial cells lining the conjunctival cysts, did not contain membrane-bound, large, pigment granules within their cytoplasm as has been demonstrated in the colloid and follicular epithelium of the thyroid following minocycline therapy.