Search PubMed⌕ Search

Biomedical subjects

T A Bell

Publications and source records attributed to T A Bell.

At least 19 recordsLinked to original sources
PubMed1994

Risk of perinatal transmission of Chlamydia trachomatis by mode of delivery.

We compared the transmission rate of Chlamydia trachomatis infection from infected women to their infants after various modes of delivery. After vaginal birth, Chlamydia trachomatis was isolated from 58 of 125 infants with a cephalic presentation, and serological evidence of chlamydial infection was found in another eight. C. trachomatis was isolated from the only infant with a frank breech presentation. After Caesarean birth, C. trachomatis was isolated from two of 10 infants born after rupture of the membranes and from one of six without prior rupture of the membranes. No serological evidence of infection was found in any of the culture-negative infants born by Caesarean section. By survival analysis, rates of transmission were significantly lower after Caesarean section with rupture of the membranes before delivery than after vaginal delivery. Infants born to infected women are at risk of C. trachomatis infection regardless of route of delivery.

Cesarean Section↗
PubMed1993

The bacterial etiology of conjunctivitis in early infancy. Eye Prophylaxis Study Group.

The authors conducted this study to determine the etiologic agents of conjunctivitis in early infancy. From 1985 to 1990, 630 infants enrolled in a randomized, controlled, double-masked study of eye prophylaxis were observed for 60 days after delivery for signs of conjunctivitis. The following isolates were categorized as pathogens: Haemophilus influenzae, Streptococcus pneumoniae, Neisseria cinerea, Klebsiella pneumoniae, and Chlamydia trachomatis. Using conditional logistic regression for analysis of 97 infant pairs, the authors identified isolates categorized as pathogens almost exclusively among cases (odds ratio (OR) = 18.0, 95% confidence interval (CI) 2.3-128). Among the microorganisms which have not usually been regarded as pathogens in the etiology of infant conjunctivitis, Streptococcus mitis was the only microorganism associated with an increased risk of conjunctivitis (OR = 5.3, 95% CI 1.8-15.0). The findings concerning the species of bacteria most often associated with conjunctivitis, as well as the finding that method of delivery is unimportant, suggest that bacteria were transmitted to the infants' eyes after birth and not from the birth canal.

Adult↗
PubMed1993

Cefixime vs. cefaclor in the treatment of acute otitis media in children: a randomized, comparative study.

The efficacy of cefixime was compared with that of cefaclor in the treatment of 63 patients with acute otitis media. Patients received either a single dose of cefixime (8 mg/kg/day) or 3 divided doses of cefaclor (40 mg/kg/day). On the basis of otoscopic and tympanometric results at 10 to 14 days after the start of treatment, 28 (97%) of 29 cefixime-treated patients and 25 (78%) of 32 cefaclor-treated patients had resolution of acute otitis media. The clinical cure rate associated with all organisms was 94% for cefixime (16 of 17 isolates) and 68% (13 of 19 isolates) for cefaclor. The cure rate for Streptococcus pneumoniae was 12 of 12 (100%) for cefixime and 7 of 7 (100%) for cefaclor; the cure rate for Haemophilus influenzae (which includes 2 patients with mixed infections) was 3 of 4 (75%) for cefixime and 2 of 7 (29%) for cefaclor. One clinical relapse occurred among 29 cefixime-treated patients; however, at 28 days 9 recurrences were observed. Three of 25 (9%) cefaclor-treated patients failed and 4 (13%) relapsed at 10 to 14 days, an additional 2 (10%) experienced recurrence by Day 28. Eight (28%) cefixime-treated patients experienced adverse events (7 gastrointestinal and 1 diarrhea and rash); 8 (25%) cefaclor-treated patients experienced adverse events (all gastrointestinal). Our data suggest that both at end of therapy and for 14 days thereafter, cefixime given once a day for acute otitis media is clinically equivalent to cefaclor given 3 times a day.

Acute Disease↗
PubMed1993

An interview study of participants in the Tacoma, Washington, syringe exchange.

Although European and Australian studies of syringe exchange programs have reported safer injection among participants and no increase in drug use, the generalizability of these findings to the US is uncertain. We report on the operations and potential effectiveness of the longest-operating syringe exchange in the US and compare our results to studies of exchange programs outside the US. The sample of 204 study subjects reported no change in the frequency of injection, from 155 to 152 injections per month, and a decline in the frequency of unsafe injections, from 56 to 30 times per month, while participating in the program. In all studies, participants report reduction in unsafe injections, and no increase in illicit drug use. However, the comparison also suggests that a high proportion of Tacoma exchangers have higher initial rates of drug injection, unsafe injection and homelessness, all of which were associated with unsafe injection while using the exchange. These indicate a need for additional services but that the Tacoma program is no less effective than European and Australian programs.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Randomized trial of silver nitrate, erythromycin, and no eye prophylaxis for the prevention of conjunctivitis among newborns not at risk for gonococcal ophthalmitis. Eye Prophylaxis Study Group.

OBJECTIVE: To compare the efficacy of commonly used forms of eye prophylaxis for newborns with no prophylaxis in the prevention of nongonococcal conjunctivitis. DESIGN: Randomized doubly masked clinical trial. SETTING: University of Washington Hospital and affiliated clinics, Seattle, between 1985 and 1990. SUBJECTS: The medical records of 8499 women were evaluated for possible participation; 2577 were eligible. Of the 758 enrolled, the infants of 630 were evaluable. INTERVENTION: Comparison of silver nitrate, erythromycin, and no eye prophylaxis given at birth for the prevention of conjunctivitis. MAIN OUTCOME MEASURES: Conjunctivitis during the first 60 days of life and nasolacrimal duct patency in the first 2 days of life. RESULTS: The frequency of impatent tear ducts at the 30- to 48-hour examination did not differ significantly by prophylaxis group. Among the 630 infants randomized and observed, 109 (17%) developed mild conjunctivitis. Sixty-nine (63%) of the cases appeared during the first 2 weeks of life. After 2 months of observation, infants allocated to silver nitrate eye prophylaxis at birth had a 39% lower rate of conjunctivitis (hazard ratio = 0.61, 95% confidence interval = 0.39 to 0.97), and those allocated to erythromycin had a 31% lower rate of conjunctivitis (hazard ratio = 0.69, 95% confidence interval = 0.44 to 1.07), than did those allocated to no prophylaxis. CONCLUSION: Silver nitrate eye prophylaxis caused no sustained deleterious effects and even provided some benefit to infants born to women without Neisseria gonorrhoeae. However, the effect was modest and against microorganisms of low virulence. The results suggest that parental choice of a prophylaxis agent including no prophylaxis is reasonable for women receiving prenatal care and who are screened for sexually transmitted diseases during pregnancy.

Adult↗
PubMed1992

Chronic Chlamydia trachomatis infections in infants.

OBJECTIVE: --To study the natural history of Chlamydia trachomatis infections in infants. DESIGN: --Bacteriologic and serologic study of an inception cohort. SETTING: --University of Washington Medical Center, Seattle. PARTICIPANTS: --Twenty-two infants with C trachomatis infections either not treated early in life or recurring after antimicrobial treatment. MAIN OUTCOME MEASURES: --Persistence of infection in various anatomic sites, antibody responses to specific serovars (serologic variants) of C trachomatis, and serovars of isolates from mothers and infants. RESULTS: --The cumulative proportion of infants still infected at the age of 1 year was 35%. Infection persisted in the conjunctiva, nasopharynx, and oropharynx in one child for as long as 866 days (28.5 months), when she was cured by treatment. In none of the infants did serologic tests suggest acquisition of infection other than at birth. Isolates of C trachomatis from mothers and their respective infants were always of the same serovar. CONCLUSIONS: --Many infants infected with C trachomatis at birth remain infected for months or years in the absence of specific antimicrobial therapy. Such infections may be confused with those acquired by sexual abuse.

Antibodies, Bacterial↗
PubMed1992

Microscopic and ultrastructural studies of necrotizing hepatopancreatitis in Pacific white shrimp (Penaeus vannamei) cultured in Texas.

Granulomatous hepatopancreatitis of unknown etiology has been considered an important disease of Texas shrimp mariculture since 1985. Samples of Pacific white shrimp (Penaeus vannamei) were collected during 1986, 1987, and 1990 from three farms and an experimental mariculture facility with histories of production loss and increased mortality rates. Histologic and ultrastructural examination of shrimp from the four sites demonstrated two morphologically distinct, Gram-negative, double-enveloped, intracytoplasmic bacteria in necrotic hepatopancreatic epithelium. The more numerous small, pleomorphic rod as well as the helical organism are both taxonomically unclassifiable. The helical organism lacked ultrastructural characteristics of previously described helical or spiral bacteria. The relationship between the two organisms is unknown, but the pleomorphic rod is thought to play a major role in the disease. The role of a bacterial agent(s) in subsequent disease episodes is suggested by the observation that the use of oxytetracycline-medicated feed resulted in increased production and survival. Hepatopancreatic tubular epithelial necrosis and shrimp mortality correlated directly with the extent of infection by the small pleomorphic rod. Individual discrete bacteria were identified microscopically by Steiner and Steiner's method. Three major developmental stages of the disease were characterized based on the extent and number of hepatopancreatic tubular epithelial cells containing bacteria, the degree of tubular interstitial inflammation, and the extent and chronicity of tubular necrosis. Additional studies are needed to clarify the roles of the different bacteria identified and the potential role of environmental factors on the disease process.

Animals↗
PubMed1991

Cost-effectiveness of prenatal testing for Chlamydia trachomatis.

We investigated the cost-effectiveness of strategies for screening pregnant women for Chlamydia trachomatis. Screening was not cost-effective unless certain conditions were met. Direct antigen testing of all pregnant women would be cost-effective if the test cost less than $6.30 or the prevalence of infection exceeded 6%. However, the positive predictive value of the test was only 51%. Culturing was not cost-effective until the prevalence of infection exceeded 14.8%. If a direct antigen test cost less than $3.90 or prevalence exceeded 8.7%, direct antigen testing of all women and using culture to confirm positive direct antigen tests would be cost-effective. If a direct antigen test cost $8.00 and culture cost $25.00, the excess cost of performing a direct antigen test in all women and confirming positive results with culture would be $2.09 per pregnant woman. Screening all pregnant women for chlamydia is not cost-effective, but the excess cost is modest when direct antigen tests are used.

Chlamydia Infections↗
PubMed1991

The biomechanical effects of deep tissue support as related to brow and facelift procedures.

The adverse effects of increased tension across a healing wound are well known. However, the effect of closing a wound in layers in order to decrease tension on the epidermis has been a source of controversy. It is hypothesized that deep tissue support decreases skin tension upon wound closure. In order to clarify this issue, a two-part study was designed to address the immediate effects of deep tissue support in vitro using fresh-frozen cadavers and in vivo on patients undergoing scheduled surgery. Closing skin tension was measured at standard reference points in coronal brow lift and rhytidectomy procedures performed with and without galeal closure and superficial musculoaponeurotic system (SMAS) procedures, respectively. Deep tissue support was found to significantly (p less than 0.05) decrease skin tension at the time of skin closure at standard reference points in coronal brow lift and rhytidectomy procedures performed on fresh-frozen cadavers. Similar significant (p less than 0.05) decreases in closing skin tension also were found in vivo in patients undergoing similar surgical procedures. Stress relaxation was not found to play a significant role in contributing to this immediate decrease in closing skin tension. It would appear, therefore, that deep tissue support, in the form of galeal closure and an SMAS procedure in coronal brow lift and rhytidectomy procedures, respectively, provides increased viscoelastic support, producing immediate significant decreases in closing skin tension in these procedures. The beneficial effects on wound healing, scar formation, tension-related trophic skin changes, and possible improved long-term results are discussed.

Adult↗
PubMed1990

Chlamydia trachomatis infections in adolescents.

The guidelines of the Centers for Disease Control should be applied with appreciation of their limitations. The serious sequelae of chlamydial infections in young patients warrant vigorous antichlamydial therapy and specific microbiologic diagnosis. Until public health authorities implement control programs, the efforts of individual practitioners will probably be the mainstay of the flight against C. trachomatis.

Adolescent↗
PubMed1990

Endometrial histopathology in patients with culture-proved upper genital tract infection and laparoscopically diagnosed acute salpingitis.

To define and quantitate histologic changes in the endometrium that best correlate with documented upper genital tract infection (UGTI) and laparoscopically diagnosed acute salpingitis, we studied endometrial biopsy specimens from 69 consecutive patients with clinically suspected acute pelvic inflammatory disease (PID) who underwent microbiological evaluation for UGTI and laparoscopic examination for acute salpingitis. Both UGTI and acute laparoscopically confirmed salpingitis were present in 37 patients (54%), UGTI without salpingitis in 1 (1%), salpingitis without UGTI in 11 (16%), and neither UGTI nor salpingitis in 20 (29%). Chlamydia trachomatis or Neisseria gonorrhoeae UGTI was found in 34 women, Escherichia coli in two patients, Peptococcus magnus in one woman, and with Streptococcus agalactiae in one woman. The following features were correlated both with UGTI and with salpingitis: presence of any neutrophils in the endometrial surface epithelium; neutrophils within gland lumens; dense subepithelial stromal lymphocytic infiltration; any stromal plasma cells; and germinal centers containing transformed lymphocytes. The simultaneous presence of five or more neutrophils per X 400 field in endometrial surface epithelium, together with one or more plasma cell per X 120 field in endometrial stroma, was the best predictor of UGTI plus salpingitis. This combination had a sensitivity of 92% and a specificity of 87% for predicting the diagnosis of both UGTI and laparoscopically confirmable acute salpingitis. Prospective studies are needed to assess the usefulness of these criteria.

Acute Disease↗