Tailored treatment of female indirect inguinal hernias by using single-port laparoscopic percutaneous internal ring suture: a comparison between children and adults.

PURPOSE: To compare the outcome of indirect inguinal hernias repaired by using single-port laparoscopic percutaneous internal ring suture (SPIRS) between the pediatric and adult females. METHODS: The medical records of females who were clinically assessed to have inguinal hernia from Oct. 2016 to May 2022 were reviewed. Patients who received laparoscopy for the diagnosis of the hernia type and customized treatment according to their hernia type were included, while those who chose other operation methods initially were excluded. The patients were divided into the adult and pediatric groups based on their age. The demographic characteristics, hernia types, operation durations, and outcomes were analyzed between these two groups. RESULTS: A total of 65 adults and 60 children were included in this study. The median age was 38 years. (range: 23-88) for group A and 3 years (range: 0.1-16) for group P. Indirect hernias were present in 85% of adults and 100% of children. All the indirect hernias were repaired by SPIRS uneventfully. Incidence of contralateral patent processus vaginalis was 24% in adults and 50% in children (p = 0.016). The average operation time was 22/46 min (one/two sides) for the adults and 9/15 min (one/two sides) for the pediatrics (p < 0.010 for both). The overall complication rates were 5.4% and 3.3% for the adult and pediatric group respectively (p = 0.106). No recurrence was observed in the pediatric group, but two adults experienced recurrence and another had chronic postoperative inguinal pain, necessitating reoperation. The mean follow-up period was 38.6 ± 15.4 months for adults and 42.8 ± 18.9 months for children (p = 0.198). CONCLUSION: Our results support that the pathogenesis of indirect inguinal hernia for the female adults is due to the non-obliteration of a congenital processus vaginalis. Tailored treatment of the female IIH by using single-port laparoscopic percutaneous internal ring suture may be an alternative for the management of female IHs.

Chondroitin Sulfate Enhances Proliferation and Migration via Inducing ß-Catenin and Intracellular ROS as Well as Suppressing Metalloproteinases through Akt/NF-κB Pathway Inhibition in Human Chondrocytes.

BACKGROUND: Chondroitin sulfate (CS) is found in humans' cartilage, bone, cornea, skin, and arterial wall. It consists of the foundation substance in the extracellular matrix (ECM) of connective tissue. The oral supplement form of CS is clinically used in treating osteoarthritis (OA). METHODS: Cell migration was observed by the transwell assay. The EMT, Akt/IKK/IκB pathways, TIMPs, collagen and MMPs in cell lysate were determined by Western blotting. The expression of MMP activity was determined by gelatin zymography. The production of reactive oxygen species (ROS) was determined by using a fluorescence spectrophotometer. RESULTS: In the current report, we demonstrated that CS can increase the cell proliferation and migration of chon-001 chondrocytes. Treatment with CS induced the epithelial-mesenchymal transition and increased the expression of type II collagen and TIMP-1/TIMP2 and inhibited the expressions and activities of metalloproteinase-9 (MMP-9) and metalloproteinase-2 (MMP-2). The phosphorylation of Akt, IκB kinase (IKK), IκB and p65 was decreased by CS. CS treatment resulted in ß-catenin production and XAV939, a ß-catenin inhibitor, and inhibited the cell proliferation by CS treatment. In addition, also significantly induced intracellular ROS generation. Treatment with antioxidant propyl gallate blocked cell migration induced by CS. CONCLUSION: We demonstrated that CS induced cell proliferation and migration of chondrocytes by inducing ß-catenin and enhancing ROS production. Moreover, our studies demonstrated that CS can increase the activity of chondrocytes and help patients with osteoarthritis to restore cartilage function.

Effects of transforming growth factor-ß1 on plasminogen activation in stem cells from the apical papilla: role of activating receptor-like kinase 5/Smad2 and mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signalling.

AIM: To study the effects of TGF-ß1 on the plasminogen activation (PA) system of stem cells from the apical papilla (SCAP) and its signalling. METHODOLOGY: SCAP cells were isolated from the apical papilla of immature permanent teeth extracted for orthodontic reasons. They were exposed to various concentration of TGF-ß1 with/without pretreatment and coincubation by SB431542 (ALK/Smad2/3 inhibitor), or U0126 (MEK/ERK inhibitor). MTT assay, Western blotting and enzyme-linked immunosorbent assay (ELISA) were used to detect their effects on cell viability, and the protein expression of plasminogen activator inhibitor-1 (PAI-1), urokinase-type plasminogen activator (uPA), uPA receptor (uPAR) and their secretion. The paired Student's t-test was used for statistical analysis. RESULTS: TGF-ß1 significantly stimulated PAI-1 and soluble uPAR (suPAR) secretion of SCAP cells (P < 0.05), whereas uPA secretion was inhibited. Accordingly, TGF-ß1 induced both PAI-1 and uPAR protein expression of SCAP cells. SB431542 (an ALK5/Smad2/3 inhibitor) pretreatment and coincubation prevented the TGF-ß1-induced PAI-1 and uPAR of SCAP. U0126 attenuated the TGF-ß1-induced expression/secretion of uPAR, but not PAI-1 in SCAP. SB431542 reversed the TGF-ß1-induced decline of uPA. CONCLUSIONS: TGF-ß1 may affect the repair/regeneration activities of SCAP via differential increase or decrease of PAI-1, uPA and uPAR. These effects induced by TGF-ß1 are associated with ALK5/Smad2/3 and MEK/ERK activation. Elucidation the signalling pathways and effects of TGF-ß1 is useful for treatment of immature teeth with open apex by revascularization/revitalization procedures and tissue repair/regeneration.

Ascending aorta replacement vs. total aortic arch replacement in the treatment of acute type A dissection: a meta-analysis.

OBJECTIVE: Acute type A aortic dissection (ATAAD) is a severe, rapidly progressing disease which typically requires patients to undergo emergency surgical intervention. Despite advancements in surgical procedures, still, ATAAD remains a surgical emergency associated with high mortality. The aim of this systematic review and meta-analysis was to compare whether either ascending aorta replacement (AR) or total aortic arch replacement (TR) leads to improved short- and long-term clinical outcomes. MATERIALS AND METHODS: A search of PubMed, Embase, Science Direct, Web of Science, SciELO, BIOSIS, and China National Knowledge Infrastructure (CNKI) databases were supplemented by searching through bibliographies of key articles. Thereafter, data on early and late prognostic factors were extracted. A systematic review and meta-analysis of 15 studies were performed to compare whether either AR or TR leads to a reduction in the risk of in-hospital and short-term mortality, postoperative complications, re-operation rate, and long-term mortality. RESULTS: A total of 15 cohort studies (n = 2822 patients with ATAAD; AR with HA, partial arch = 1911, TR = 911) were deemed eligible and included in the meta-analysis. Compared with TR, AR led to a significantly lower risk of in-hospital mortality (RR = 0.77; 95% CI: 0.61-0.96), shorter cardiopulmonary bypass time (CPB, mean difference = -53.09; 95% CI: -56.68--49.50), circulatory arrest time (CA, mean difference = -8.09; 95% CI: -9.04-7.15), and antegrade cerebral perfusion (ACP, mean difference = -28.62; 95% CI: -30.23--27.00). Differences in the incidence rates of neurological dysfunctions and renal dialysis were not significant. The pooled rate of aortic re-operation was lower in TR group (AR 7.6% vs. TR 5.3%), albeit not significantly (risk ratio = 1.39; 95% CI: 0.94-2.07; p = 0.10). CONCLUSIONS: These findings demonstrate that AR is associated with a lower early mortality rate and shorter operative times overall. Nevertheless, the incidence of postoperative complications in patients undergoing AR is comparable to that of patients undergoing TR. Further prospective follow-up data needs to be collected and analyzed to discern whether there are statistically significant differences in the risks of re-operation and long-term mortality between AR and TR procedures.

Prevalence of post-operative morbidity risk factors following cardiac surgery in patients with chronic viral hepatitis: a retrospective study.

OBJECTIVE: Current cardiac risk assessments such as EuroSCORE II and the STS-Score do not take liver dysfunction into account. The purpose of this study was to evaluate the prevalence and post-operative morbidity risk factors following cardiac surgery of patients with chronic viral hepatitis. PATIENTS AND METHODS: The study group consisted of 105 patients with documented chronic viral hepatitis who were subject to elective cardiac surgery from 2001 to 2012. Subjects were evaluated for pre-operative liver dysfunction according to the MELD score. RESULTS: The average MELD score of the study group was 10.00 ± 6.00. The average EuroSCORE ii of the study group was 2.07% ± 1.62%. The primary post-operative complication was cardiac complications (n=57, 54.3%). Analysis showed significant differences in meld score, bilirubin and smoking. Multivariate logistic regression analysis showed that the variables entering into the model included such risk factors with a significant or near significant (p < 0.2) influence on hospital morbidity and consisted in valve vs. coronary artery disease, valve/cad, aortic valve replacement vs. Coronary artery bypass graft, and bilirubin (mg/dl). CONCLUSIONS: it is vital that liver dysfunction is added to the risk models which are currently utilized to predict the post-operative morbidity of cardiac surgery patients.

Molecular dynamics simulations of various coronavirus main proteinases.

In this study, two homology models (denoted as MproST and MproSH) of main proteinase (Mpro) from the novel coronavirus associated with severe acute respiratory syndrome (SARS-CoV) were constructed based on the crystal structures of Mpro from transmissible gastroenteritis coronavirus (TGEV) (MproT) and human coronavirus HcoV-229E (MproH), respectively. Both MproST and MproSH exhibit similar folds as their respective template proteins. These homology models reveal three distinct functional domains as well as an intervening loop connecting domains II and III as found in both template proteins. A catalytic cleft containing the substrate binding sites S1 and S2 between domains I and II are also observed. S2 undergoes more significant structural fluctuation than S1 during the 400 ps molecular dynamics simulations because it is located at the open mouth of the catalytic cleft, while S1 is situated in the very bottom of this cleft. The thermal unfolding of these proteins begins at domain III, where the structure is least conserved among these proteins. Mpro may still maintain its proteolytic activity while it is partially unfolded. The electrostatic interaction between Arg40 and Asp186 plays an important role in maintaining the structural integrity of both S1 and S2.

Cloning, expression and characterization of a poly(3-hydroxybutyrate) depolymerase from Marinobacter sp. NK-1.

A DNA fragment carrying the gene encoding poly(3-hydroxybutyrate) (P(3HB)) depolymerase was cloned from the genomic DNA of Marinobacter sp. DNA sequencing analysis revealed that the Marinobacter sp. P(3HB) depolymerase gene is composed of 1734bp and encodes 578 amino acids with a molecular mass of 61,757Da. A sequence homology search showed that the deduced protein contains the signal peptide, catalytic domain (CD), cadherin-type linker domain (LD), and two substrate-binding domain (SBD). The fusion proteins of glutathione S-transferase (GST) with the CD showed the hydrolytic activity for denatured P(3HB) (dP(3HB)), P(3HB) emulsion (eP(3HB)) and p-nitrophenylbutyrate. On the other hand, the fusion proteins lacking the SBD showed much lower hydrolytic activity for dP(3HB) compared to the proteins containing both CD and SBD. In addition, binding tests revealed that the SBDs are specifically bound not to eP(3HB) but dP(3HB). These suggest that the SBDs play a crucial role in the enzymatic hydrolysis of dP(3HB) that is a solid substrate.

In vitro activity of linezolid against clinical Gram-positive bacterial isolates from Taiwan: an area with a high prevalence of antibiotic resistance.

The prevalence of antibiotic-resistant bacteria in Taiwan is due to the heavy use of antimicrobial agents in both animal husbandry and clinical practice over the past decades. Minimum inhibitory concentrations (MICs) of linezolid were established for 371 clinical isolates of staphylococci, pneumococci, enterococci and group A streptococci from Taiwan. All isolates tested including those resistant to beta-lactams, erythromycin, vancomycin and quinupristin-dalfopristin were uniformly susceptible to linezolid, with MICs ranging from 0.125 to 2 mg/l. Our data support the observation that there is no cross-resistance between linezolid and other classes of antimicrobial substances.

Baicalein induces a dual growth arrest by modulating multiple cell cycle regulatory molecules.

Baicalein, a flavonoid present in the root of Scutellaria baicalensis Georgi, has been reported to inhibit cell proliferation in several types of cells. In this study, the effect of baicalein on cell growth and the mechanism of growth modulation were examined in primary cultured rat heart endothelial cells. Here, we report that treatment with 100-microM baicalein caused an almost complete inhibition of cell proliferation after 5 days of incubation. Baicalein mediated G1 and G2 growth arrest accompanied by the down-regulation of cyclin D2, cyclin A, cyclin-dependent kinase 1 (Cdk1) and cyclin-dependent kinase 2 (Cdk2), and up-regulation of p15(Ink4B), p21(CIP1/Waf1), p53 and cyclin E. Evaluation of the kinase activity of cyclin-Cdk complexes showed that baicalein decreased Cdk1, Cdk2, cyclin D2 and cyclin A expression in endothelial cells, leading to markedly reduced Cdk/cyclin-associated kinase activities. These results suggest that baicalein inhibits the proliferation of rat heart endothelial cells via G1 and G2 arrest in association with the down-regulation of the expression and function of Cdk1, Cdk2, cyclin D2 and cyclin A proteins, and up-regulation of cyclin E, p15(Ink4B), p53 and p21(CIP1/Waf1).

Paraneoplastic pemphigus in association with a retroperitoneal Castleman's disease presenting with a lichen planus pemphigoides-like eruption. A case report and review of literature.

A 50-year-old man presented with severe mucosal erosions of the lips, oral cavity and perianal area, a lichen planus-like eruption on the trunk and extremities and scaly plaques of the palms and soles. The clinical impression was of Stevens--Johnson syndrome, or paraneoplastic pemphigus (PNP). Histopathology revealed vacuolar interface and lichenoid dermatitis with dyskeratosis and suprabasal acantholytic vesiculation. Direct immunofluorescence showed deposition of IgG in the intercellular space and linear deposition of C3 along the basal membrane zone. Indirect immunofluorescence revealed circulating IgG with intercellular staining of the epithelium of rat urinary bladder. Western blotting demonstrated bands of 250- and 230-kDa antigens. The clinical, histological and immunological features were consistent with the lichen planus pemphigoides variant of PNP. A retroperitoneal hyaline-vascular Castleman's disease was detected and excised. The skin lesions worsened initially after tumour resection but improved gradually, leaving extensive melanosis after cyclosporin and mycophenolate mofetil treatment.

In vitro aberrant gene expression as the indicator of lead-induced neurotoxicity in U-373MG cells.

Lead is an important neurobehavioral toxicant and may interfere with developmental processes in the brain resulting in impairment of its functions. U-373MG, a human glioma cell line, was cultured in Dulbecco's modified Eagles' medium supplemented with either 20 or 10% FBS (fetal bovine serum) to explore the possible indications for lead-induced toxicity. Although lead did not affect cell growth rate in concentrations ranging from 0.01 to 10 microM, it substantially altered gene expression analyzed by reverse-transcription polymerase chain reaction. With 10% FBS culture, lead affected the gene expression in a dose-dependent relationship. It enhanced the expression of tumor necrosis factor-alpha (TNF-alpha), but decreased those of interleukin-1beta (IL-1beta), interleukin-6 (IL-6), gamma-aminobutyric acid (GABA) transaminase, and glutamine synthetase. With 20% FBS culture, lead also profoundly increased TNF-alpha and IL-1beta; however, it did not extensively affect the other genes examined above. Thus, the highly sensitive changes of gene expression of these cytokines or metabolic enzymes after treatments with lead acetate evidenced their usefulness as indicators for in vitro measurement of lead-induced neurotoxicity.

Cryptococcal meningitis in non-HIV-infected patients.

There are few reports on cryptococcal meningitis in non-HIV-infected patients in subtropical areas. We reviewed 94 non-HIV-infected patients microbiologically diagnosed with cryptococcal meningitis and hospitalized at National Taiwan University Hospital, 1977-1996. Forty-two patients (44.7%) had underlying diseases. The main initial manifestations were headache (86.2%), vomiting (72.3%) and fever (69. 1%). The 30 patients with T-cell suppression had more acute illnesses (median duration of symptoms: 14 days vs. 29 days), less typical presentations of meningitis, and reduced inflammatory responses compared with the 64 without T cell suppression. There was no statistical difference between patients who received amphotericin B treatment for 10 weeks and those received amphotericin B with subsequent fluconazole treatment, in terms of mortality rate and recurrence rate. Seventy-five patients (79.8%) had satisfactory clinical responses, and two relapsed. Eighteen patients died (19.1%) and 10 of these died within 2 weeks of hospitalization. Patients in this series had outcomes comparable with those from temperate and even tropical countries with high percentages of immunocompetent hosts. Factors significantly associated with death were lymphoma, semicoma, leukocytosis, and initial high titres of cryptococcal antigen in cerebral spinal fluid (especially >/=1 : 512). On multivariate analysis, lymphoma and initial high cryptococcal antigen titres were independent predictors of mortality.

High prevalence of antibiotic resistance of common pathogenic bacteria in Taiwan. The Antibiotic Resistance Study Group of the Infectious Disease Society of the Republic of China.

We analyzed the antimicrobial susceptibilities of all clinical isolates of 14 common pathogenic bacteria recovered from patients in eight medical centers in Taiwan during 1995 and 1996. Susceptibility to commonly used antimicrobial agents was tested by the disk diffusion method as recommended by the National Committee for Clinical Laboratory Standards. Of the Staphylococcus aureus isolates, 59.3% and 62% were oxacillin-resistant in 1995 and 1996, respectively, whereas 63.2% of the coagulase-negative staphylococci isolates during the study period were oxacillin-resistant. The rate of penicillin-resistance among Streptococcus pneumoniae isolates was 39.7% in 1995 and 53.7% in 1996. Macrolide-resistance was found in 71.4%, 42.1%, and 46.7% of S. pneumoniae, beta-hemolytic streptococci, and viridans streptococci, respectively, in 1996. Less than 2% of the enterococcal isolates were vancomycin resistant, but 77% of them were gentamicin resistant. Resistance to gentamicin was also common in Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter baumannii. Various degrees of resistance to ampicillin, piperacillin, cephalosporins, aztreonam, and ciprofloxacin were detected in Enterobacteriaceae, P. aeruginosa, and A. baumannii. More than 55% of Haemophilus influenzae isolates were ampicillin resistant. In summary, resistance to many antimicrobial agents in various common pathogenic bacteria is very common in Taiwan. Our results implicate that antibiotic resistance in the developing countries need to be monitored closely.

Clinical features and in vitro susceptibilities of two varieties of Cryptococcus neoformans in Taiwan.

One hundred years after introduction of the Eucalyptus tree to Taiwan, a predominantly subtropical island, we analyzed clinical and microbiological data of 59 patients with Cryptococcus neoformans infection hospitalized at National Taiwan University Hospital during 1982 to 1997. There were 38 (64.4%) cases of cryptococcosis caused by the var. neoformans and 21 (35.6%) caused by the var. gattii. Thirty-three patients (55.9%) had impaired T cell function, which included 12 patients with acquired immunodeficiency syndrome (AIDS). Eleven of the 12 patients with AIDS were diagnosed after 1995, and 11 cases were caused by var. neoformans. Minimum inhibitory concentrations (MICs) determined by the NCCLS broth microdilution method using antibiotic medium 3 improved the discrimination of in vitro susceptibility against amphotericin B and demonstrated that var. gattii isolates were less susceptible (geometric means 0.25 microg/ml versus 0.64 microg/ml, P < 0.001). In addition, a higher proportion of var. gattii were less susceptible to flucytosine as compared with var. neoformans (35.0% versus 64.9%, P = 0.030). There was no seasonal clustering for isolation of var. neoformans, though infections caused by var. gattii peaked in July and August. Compared with the first study of cryptococcosis (1957-1972) at NTUH, this study demonstrated the increase in immunocompromised and elderly patients, as well as a higher proportion of Cryptococcus isolated from blood or bone marrow. Facing the increasing adaptive plantation of Eucalyptus in Taiwan, the importance of field study regarding the role of Eucalyptus plantations in Taiwan and occurrence of cryptococcosis in human beings cannot be over-emphasized.

Imported malaria: successful treatment of 31 patients in the era of chloroquine resistance.

The diagnosis and management of imported malaria presents a continuing challenge in developed countries, including Taiwan. We retrospectively analyzed the records of all 31 patients with imported malaria treated at National Taiwan University Hospital from January 1984 through December 1998. Plasmodium falciparum was identified as the causative malarial parasite in 18 patients, P. vivax in 12, and P. ovale in one. All 31 patients had fever, but only 13 presented with the characteristic fever pattern. The most common initial laboratory abnormalities were thrombocytopenia (20/31), mild hyperbilirubinemia (20/31), and leukopenia (7/31). The median time from the onset of fever to the correct diagnosis was 4 days for P. falciparum and 5 days for P. vivax. In 28 cases, the clue that led to early diagnosis was the patient's travel history. Quinine, but not chloroquine, was effective in 17 out of 18 cases of falciparum malaria. Three patients treated with intravenous quinine required a change of regimen because of life-threatening quinine toxicity; artesunate served as a safe and effective alternative in this situation. While most patients with tertian malaria were cured with the standard chloroquine and primaquine regimen, a higher dosage was required for one case acquired in Papua New Guinea. All patients, including two with severe malaria, survived. We conclude that, the mortality of imported malaria in the chloroquine resistance era can be minimized with early recognition by obtaining a thorough travel history, and instituting appropriate antimalarial chemotherapy based on precise identification of species. Quinine toxicity should be closely monitoried, especially when this drug is given intravenously.

In vitro activity of quinupristin/dalfopristin against clinical isolates of common gram-positive bacteria in Taiwan.

The MICs of quinupristin/dalfopristin against common Gram-positive bacteria isolated from various clinical specimens at a university hospital in Taiwan were determined by the agar dilution method. The tested bacteria included methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus (MSSA), methicillin-resistant Staphylococcus epidermidis (MRSE), methicillin-susceptible S. epidermidis (MSSE), Streptococcus pyogenes, Streptococcus pneumoniae, and Enterococcus faecalis. With the exception of E. faecalis all bacteria were susceptible to quinupristin/dalfopristin. The MIC50 and MIC90 were, respectively, 0.25 microgram/mL and 0.5 microgram/mL for both MRSA and MSSA; 0.25 microgram/mL and 0.5 microgram/mL for MRSE; 0.25 microgram/mL and 0.25 microgram/mL for MSSE; 0.125 microgram/mL and 0.125 microgram/mL for S. pyogenes; and < or = 0.03 microgram/mL and 0.25 microgram/mL for S. pneumoniae. Eighty-two percent of the tested E. faecalis isolates were intermediately resistant or resistant to quinupristin/dalfopristin, with an MIC50 of 2 micrograms/mL and an MIC90 of 4 micrograms/mL. Quinupristin/dalfopristin seems to be a promising antimicrobial agent against common Gram-positive bacteria other than E. faecalis in Taiwan.

Antithyroid-drug-induced agranulocytosis complicated by life-threatening infections.

Agranulocytosis is a rare complication of antithyroid drugs, and the aetiologies of community-acquired, life-threatening infections in patients taking these drugs have not previously been systematically described. Of 5653 hyperthyroid patients treated with antithyroid drugs at National Taiwan University Hospital between January 1987 and December 1997, 13 (0.23%) developed agranulocytosis with life-threatening infections. The most common presentations were fever (92%) and sore throat (85%). Initial clinical diagnoses were acute pharyngitis (46%), acute tonsillitis (38%), pneumonia (15%) and urinary tract infection (8%). Positive blood cultures from six patients yielded Pseudomonas aeruginosa (3), Escherichia coli (1), Staphylococcus aureus (1), Capnocytophaga species (1). Two patients died of uncontrolled infection, thyroid storm and multiple organ failure. Cases of antithyroid-drug-induced agranulocytosis in the English language literature are reviewed; Gram-negative bacilli, including Klebsiella pneumoniae (4 patients) and P. aeruginosa (3), were the most common pathogens in clinical isolates. Our observation and review suggest that broad-spectrum antibiotics with anti-pseudomonal activity should be given to patients with antithyroid drug-induced agranulocytosis who present with severe infection.

Effect of UV exposure and beta-carotene supplementation on delayed-type hypersensitivity response in healthy older men.

OBJECTIVES: The aims of this study were to determine if ultraviolet light (UV) is immunosuppressive in healthy older males, if beta-carotene (betaC) supplementation could prevent any observed UV-induced immunosuppression, and to compare these effects with those observed previously in younger men. METHODS: The study was a placebo-controlled, randomized trial that employed a 2 x 2 factorial design. Healthy older men (mean age 65.5 years) received 30 mg betaC or placebo daily throughout the 47-day trial, while on a low carotenoid diet. After 28 days, half of each group received 12 suberythemic exposures to UV over a 16-day period. Delayed-type hypersensitivity (DTH) tests and plasma carotenoid assays were performed at baseline, pre-UV and post-UV time points, with DTH testing performed on an area of skin protected from UV exposure. RESULTS: UV exposure resulted in significantly suppressed DTH response in the placebo group but not in the betaC-UV group. While there was no significant interaction between betaC supplementation and UV on DTH response, there was a significant inverse relationship between final plasma betaC concentration and extent of UV-induced suppression of DTH response. A similar correlation existed among subjects not exposed to UV. CONCLUSIONS: Suberythemic UV exposure was immunosuppressive, as measured by DTH response, in healthy older men as in younger men. Higher plasma betaC was significantly associated with maintenance of DTH response, although the extent of protective effect of betaC appeared less than previously observed in younger subjects. The attenuated effect of betaC in the older UV-exposed subjects may have resulted in part from muted plasma betaC responses to betaC supplementation and/or higher plasma vitamin E levels than those of younger men. The finding that stronger DTH responses were associated with higher plasma betaC concentrations in both UV and non-UV subjects further supports a role for this nutrient in immunomodulation.