A massive outbreak in Milwaukee of cryptosporidium infection transmitted through the public water supply

BACKGROUND

Early in the spring of 1993 there was a widespread outbreak of acute watery diarrhea among the residents of Milwaukee.

METHODS

We investigated the two Milwaukee water-treatment plants, gathered data from clinical laboratories on the results of tests for enteric pathogens, and examined ice made during the time of the outbreak for cryptosporidium oocysts. We surveyed residents with confirmed cryptosporidium infection and a sample of those with acute watery diarrhea consistent with cryptosporidium infection. To estimate the magnitude of the outbreak, we also conducted a survey using randomly selected telephone numbers in Milwaukee and four surrounding counties.

RESULTS

There were marked increases in the turbidity of treated water at the city's southern water-treatment plant from March 23 until April 9, when the plant was shut down. Cryptosporidium oocysts were identified in water from ice made in southern Milwaukee during these weeks. The rates of isolation of other enteric pathogens remained stable, but there was more than a 100-fold increase in the rate of isolation of cryptosporidium. The median duration of illness was 9 days (range, 1 to 55). The median maximal number of stools per day was 12 (range, 1 to 90). Among 285 people surveyed who had laboratory-confirmed cryptosporidiosis, the clinical manifestations included watery diarrhea (in 93 percent), abdominal cramps (in 84 percent), fever (in 57 percent), and vomiting (in 48 percent). We estimate that 403,000 people had watery diarrhea attributable to this outbreak.

CONCLUSIONS

This massive outbreak of watery diarrhea was caused by cryptosporidium oocysts that passed through the filtration system of one of the city's water-treatment plants. Water-quality standards and the testing of patients for cryptosporidium were not adequate to detect this outbreak.

Oral mucositis and the clinical and economic outcomes of hematopoietic stem-cell transplantation

PURPOSE

To explore the relationship between oral mucositis and selected clinical and economic outcomes in blood and marrow transplant patients.

PATIENTS AND METHODS

Subjects consisted of 92 transplant patients from eight centers who participated in a multinational pilot study of a new oral mucositis scoring system (Oral Mucositis Assessment Scale [OMAS]). In the pilot study, patients were evaluated for erythema and ulceration/pseudomembrane formation beginning on the first day of conditioning and continuing for 28 days. We examined the relationship between patients' peak OMAS scores and days with fever (body temperature > 38.0 degrees C), the occurrence of significant infection, days of total parenteral nutrition (TPN), and days of injectable narcotic therapy (all over 28 days), days in hospital (over 60 days), total hospital charges for the index admission, and vital status at 100 days.

RESULTS

Patients' peak OMAS scores spanned the full range of possible values (0 to 5) and were significantly (P <.05) correlated with all of the outcomes of interest except days with fever (P =.21). In analyses controlling for type of graft (autologous v allogeneic) and study center, a 1-point increase in peak OMAS score was associated with (1) 1.0 additional day with fever (P <.01), (2) a 2.1-fold increase in risk of significant infection (P <.01), (3) 2.7 additional days of TPN (P <.0001), (4) 2.6 additional days of injectable narcotic therapy (P <.0001), (5) 2.6 additional days in hospital (P <.01), (6) $25,405 in additional hospital charges (P <.0001), and (7) a 3.9-fold increase in 100-day mortality risk (P <.01). Mean hospital charges were $42,749 higher among patients with evidence of ulceration compared with those without (P =.06).

CONCLUSION

Oral mucositis is associated with significantly worse clinical and economic outcomes in blood and marrow transplantation.

"U" curve association of blood pressure and mortality in hemodialysis patients. Medical Directors of Dialysis Clinic, Inc

BACKGROUND

Hypertension may play an important role in the pathogenesis of the excess cardiovascular and cerebrovascular (CV) morbidity observed in hemodialysis patients (HD). However, the optimal blood pressure (BP) range for HD patients has not been defined. We postulated that there is a "U" curve relationship between BP and CV mortality. To explore this hypothesis we studied 5,433 HD patients in Dialysis Clinic Inc., a large not-for-profit chain, over a five year period.

METHODS

Cox regression, with fixed and time-varying covariates, was used to assess the effect of systolic blood pressure (SBP) and diastolic blood pressure (DBP), pre- and post-dialysis, on CV mortality, while adjusting for age, gender, ethnicity, primary cause of end-stage renal disease, Kt/V, serum albumin, and antihypertensive medications.

RESULTS

The overall impact of BP on CV mortality was modest. Pre-dialysis, neither systolic nor diastolic hypertension were associated with an increase in CV mortality. Post-dialysis, SBP > or = 180 mm Hg (RR = 1.96, P < 0.015) and DBP > or = 90 mm Hg (RR = 1.73, P < 0.05) were associated with increased CV mortality. Low SBP (SBP < 110 mm Hg) was associated with increased CV mortality, pre- and post-dialysis.

CONCLUSIONS

The results suggest the presence of a "U" curve relationship between SBP post-dialysis and CV mortality in HD patients.

Validation of a new scoring system for the assessment of clinical trial research of oral mucositis induced by radiation or chemotherapy. Mucositis Study Group

BACKGROUND

An impediment to mucositis research has been the lack of an accepted, validated scoring system. The objective of this study was to design, test, and validate a new scoring system for mucositis that can be used easily, is reproducible, and provides an accurate system for research applications.

METHODS

A panel of experts, convened to design an objective, simple, and reproducible assessment tool to evaluate mucositis with specific application to multicenter clinical trials, developed a scale that measured objective and subjective indicators of mucositis. Nine centers participated in the study's validation. Paired investigators at each center evaluated patients receiving chemotherapy or head and neck radiation. Objective measures of mucositis evaluated ulceration/pseudomembrane formation and erythema. Subjective outcomes of mouth pain, ability to swallow, and function were measured. Analgesia use for mouth sensitivity was recorded.

RESULTS

One hundred eight chemotherapy and 56 radiation therapy patients were evaluated. Seventy-eight percent of chemotherapy patients and 64% of radiation therapy patients had clinically significant mucositis. Cumulative daily mucositis scores demonstrated a high correlation among observers. Using area under the curve analysis, it was found that for chemotherapy patients, the highest correlations (correlation coefficient > 0.92) occurred for the scores that selected the three highest daily values over the course of mucositis assessment. High interobserver correlations were noted for patients receiving radiation therapy. Objective mucositis scores demonstrated strong correlation with symptoms.

CONCLUSIONS

The scoring system evaluated was easily used, showed high interobserver reproducibility, was responsive over time, and measured those elements deemed to be associated with mucositis. The use of concomitant symptomatic measurements appeared to be unnecessary.

A redox-based O2 sensor in rat pulmonary vasculature

The effector mechanism of hypoxic pulmonary vasoconstriction (HPV) involves K+ channel inhibition with subsequent membrane depolarization. It remains uncertain how hypoxia modulates K+ channel activity. The similar effects of hypoxia and mitochondrial electron transport chain (ETC) inhibitors on metabolism and vascular tone suggest a common mechanism of action. ETC inhibitors and hypoxia may alter cell redox status by causing an accumulation of electron donors from the Krebs cycle and by decreasing the production of activated O2 species (AOS) by the ETC. We hypothesized that this shift toward a more reduced redox state elicits vasoconstriction by inhibition of K+ channels. Pulmonary artery pressure and AOS, measured simultaneously using enhanced chemiluminescence, were studied in isolated perfused rat lungs during exposure to hypoxia, proximal ETC inhibitors (rotenone and antimycin A), and a distal ETC inhibitor (cyanide). Patch-clamp measurements of whole-cell K+ currents were made on freshly isolated rat pulmonary vascular smooth muscle cells during exposure to hypoxia and ETC inhibitors. Hypoxia, rotenone, and antimycin A decreased lung chemiluminescence (-62 +/- 12, -46 +/- 7, and -148 +/- 36 counts/0.1 s, respectively) and subsequently increased pulmonary artery pressure (+14 +/- 2, +13 +/- 3, and +21 +/- 3 mm Hg, respectively). These agents reversibly inhibited an outward, ATP-independent, K+ current in pulmonary vascular smooth muscle cells. Antimycin A and rotenone abolished subsequent HPV. In contrast, cyanide increased AOS and did not alter K+ currents or inhibit HPV. The initial effect of rotenone, antimycin A, and hypoxia was a change in redox status (evident as a decrease in production of AOS). This was associated with the reversible inhibition of an ATP-independent K+ channel and vasoconstriction. These findings are consistent with the existence of a redox-based O2 sensor in the pulmonary vasculature.

Isolation of Aeromonas hydrophila from a metropolitan water supply: seasonal correlation with clinical isolates

The occurrence of Aeromonas spp. in the metropolitan water supply of Perth, Western Australia, Australia, was monitored at several sampling points during a period of 1 year. Water within the distribution system conformed to international standards for drinking water but contained Aeromonas spp. in numbers comparable to those in raw surface water, although this water was free of Escherichia coli. Coliforms and E. coli were found in raw surface waters, and Aeromonas spp. were found in raw water from surface and underground sources. Chemical treatment, followed by chlorination at service reservoirs, resulted in water free of E. coli and a decrease in the number of Aeromonas spp. Aeromonas spp. were found in the greatest numbers in summer. Multiple regression analysis showed that growth of Aeromonas spp. in chlorinated water was related to water temperature, residual chlorine, and interaction between these variables. The incidence of Aeromonas-associated gastroenteritis, determined from isolates referred to us for enterotoxin testing, paralleled the pattern of isolation of Aeromonas spp. in water within the distribution systems. We suggest that the presence of Aeromonas spp. in drinking water needs public health appraisal and that further work should be undertaken to permit reevaluation of standards for the quality of drinking water.

Massive outbreak of waterborne cryptosporidium infection in Milwaukee, Wisconsin: recurrence of illness and risk of secondary transmission

Contamination of the public water supply in Milwaukee during March and April 1993 resulted in a massive outbreak of cryptosporidium infection. We investigated the clinical and epidemiological features of visitors to the Milwaukee area in whom cryptosporidiosis developed, and we conducted a telephone survey of Milwaukee County households to evaluate the risk of recurrent illness and secondary transmission. Cryptosporidium infection during this outbreak generally seemed more severe than cases described in previous reports of large case series. The risk of secondary transmission within a household was low (5%) when the index case involved an adult. The recurrence of watery diarrhea after apparent recovery was a frequent occurrence among visitors with laboratory-confirmed cryptosporidium infection (39%) and among visitors and Milwaukee County residents with clinical infection (21%). The interval between the initial recovery and the onset of recurrence was prolonged (> or = 5 days) in 6%-8% of persons. This pattern of recurrence and its impact on transmission and our understanding of the pathophysiological mechanisms of cryptosporidium infection merit further investigation.

Ultralong single-wall carbon nanotubes

Since the discovery of carbon nanotubes in 1991 by Iijima, there has been great interest in creating long, continuous nanotubes for applications where their properties coupled with extended lengths will enable new technology developments. For example, ultralong nanotubes can be spun into fibres that are more than an order of magnitude stronger than any current structural material, allowing revolutionary advances in lightweight, high-strength applications. Long metallic nanotubes will enable new types of micro-electromechanical systems such as micro-electric motors, and can also act as a nanoconducting cable for wiring micro-electronic devices. Here we report the synthesis of 4-cm-long individual single-wall carbon nanotubes (SWNTs) at a high growth rate of 11 microm s(-1) by catalytic chemical vapour deposition. Our results suggest the possibility of growing SWNTs continuously without any apparent length limitation.

Benzydamine HCl for prophylaxis of radiation-induced oral mucositis: results from a multicenter, randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

Benzydamine was evaluated in patients with head and neck carcinoma for treatment of radiation-induced oral mucositis, a frequent complication of radiation therapy (RT) for which there is no predictable therapy or preventive treatment currently available.

METHODS

The safety and efficacy of 0.15% benzydamine oral rinse in preventing or decreasing erythema, ulceration, and pain associated with oral mucositis during RT were evaluated in a randomized, placebo-controlled trial conducted in patients with head and neck carcinoma. Subjects were to rinse with 15 mL for 2 minutes, 4-8 times daily before and during RT, and for 2 weeks after completion of RT; study evaluations were conducted before RT and routinely thereafter up to 3 weeks after RT.

RESULTS

During conventional RT, regimens up to cumulative doses of 5000 centigrays (cGy) benzydamine (n = 69) significantly (P = 0.006) reduced erythema and ulceration by approximately 30% compared with the placebo (n = 76); greater than 33% of benzydamine subjects remained ulcer free compared with 18% of placebo subjects (P = 0.037), and benzydamine significantly delayed the use of systemic analgesics compared with placebo (P < 0.05). Benzydamine was not effective in subjects (n = 20) receiving accelerated RT doses (> or = 220 cGy/day). The incidence of adverse events between treatment groups was comparable without significant differences. Early discontinuation because of adverse events occurred in 6% of benzydamine subjects and 5% of placebo subjects, and there was 1 death (related to the primary diagnosis) in a placebo subject.

CONCLUSIONS

Benzydamine oral rinse was effective, safe, and well tolerated for prophylactic treatment of radiation-induced oral mucositis.

Identification of a novel selD homolog from eukaryotes, bacteria, and archaea: is there an autoregulatory mechanism in selenocysteine metabolism?

Escherichia coli selenophosphate synthetase (SPS, the selD gene product) catalyzes the production of monoselenophosphate, the selenium donor compound required for synthesis of selenocysteine (Sec) and seleno-tRNAs. We report the molecular cloning of human and mouse homologs of the selD gene, designated Sps2, which contains an in-frame TGA codon at a site corresponding to the enzyme's putative active site. These sequences allow the identification of selD gene homologs in the genomes of the bacterium Haemophilus influenzae and the archaeon Methanococcus jannaschii, which had been previously misinterpreted due to their in-frame TGA codon. Sps2 mRNA levels are elevated in organs previously implicated in the synthesis of selenoproteins and in active sites of blood cell development. In addition, we show that Sps2 mRNA is up-regulated upon activation of T lymphocytes and have mapped the Sps2 gene to mouse chromosome 7. Using the mouse gene isolated from the hematopoietic cell line FDCPmixA4, we devised a construct for protein expression that results in the insertion of a FLAG tag sequence at the N terminus of the SPS2 protein. This strategy allowed us to document the readthrough of the in-frame TGA codon and the incorporation of 75Se into SPS2. These results suggest the existence of an autoregulatory mechanism involving the incorporation of Sec into SPS2 that might be relevant to blood cell biology. This mechanism is likely to have been present in ancient life forms and conserved in a variety of living organisms from all domains of life.

A recombinant Salmonella typhimurium vaccine induces local immunity by four different routes of immunization

Immunization of mice with an attenuated Salmonella typhimurium strain (Phopc) carrying a plasmid encoding a hybrid form of the hepatitis B virus core antigen (HBc) induced specific antibody responses against the bacterial lipopolysaccharide (LPS) and HBc. Different mucosal routes of immunization, i.e., oral, nasal, rectal, and vaginal, were compared for their ability to induce a systemic as well as a mucosal response at sites proximal or distant to the site of immunization. Anti-LPS and anti-HBc immunoglobulin A (IgA) antibodies were measured in saliva, in feces, and in genital, bronchial, and intestinal secretions. Specific antibodies in serum and secretions were observed after immunization via all routes; however, the response to LPS was independent of that against HBc. In serum, saliva, and genital and bronchial secretions, high amounts of anti-HBc IgA were obtained by the nasal route of immunization. Vaginal immunization resulted in two different responses in mice: high and low. We observed a correlation between the level of specific immune response and the estrous status of these mice at the time of immunization. Rectal immunization induced high amounts of IgA against HBc and LPS in colonorectal secretions and feces but not at distant sites. These data suggest that S. typhimurium is able to invade different mucosal tissues and induce long-lasting local IgA responses against itself and a carried antigen after a single immunization.

A novel technique for laminoplasty augmentation of spinal canal area using titanium miniplate stabilization. A computerized morphometric analysis

STUDY DESIGN

Titanium miniplates are used to secure the posterior elements in the open position after expansive open-door laminoplasty. Preoperative and postoperative spinal canal dimensions are measured to assess the effectiveness of this technique.

OBJECTIVES

To develop a simple yet effective technique to stabilize the posterior elements after laminoplasty and to compare preoperative and postoperative spinal canal dimensions to accepted normal values.

SUMMARY OF BACKGROUND DATA

Expansive open-door laminoplasty has been offered as a simple alternative to laminectomy, which has been associated with postoperative kyphosis. Although the technique of laminoplasty is effective, a simple and reliable method of holding the posterior elements open has not been described.

METHODS

Ten myelopathic patients with multilevel cervical canal stenosis secondary to spondylosis or ossification of the posterior longitudinal ligament were treated with an expansive open-door laminoplasty. The posterior elements were stabilized in the open position with titanium miniplates. Computer-assisted morphometric analysis was performed on preoperative and postoperative computed tomography scans to obtain spinal canal dimensions. Plain radiographs were used to monitor construct integrity.

RESULTS

The preoperative sagittal canal diameter was 8.2 +/- 0.96 mm, and the canal area was 180.6 +/- 33.7 mm2. These dimensions increased after surgery to 16.6 +/- 1.5 mm and 321.9 +/- 29.7 mm2, respectively. The titanium miniplate constructs did not fail during the follow-up period (mean, 26.4 months), and the decompression was maintained. The single significant complication was transient C5 radiculopathy.

CONCLUSIONS

Normal canal dimensions can be reestablished with open-door laminoplasty. Achieving and maintaining an increased sagittal canal diameter is probably the most important change in anatomic parameters to facilitate neurologic recovery. The use of titanium miniplates to stabilize the posterior elements after laminoplasty is a simple, durable, and effective technique to maintain the increased sagittal diameter of the spinal canal.

Low energy Helium-Neon laser in the prevention of oral mucositis in patients undergoing bone marrow transplant: results of a double blind randomized trial

PURPOSE

To evaluate the efficiency of Helium-Neon (He-Ne) laser in the prevention of oral mucositis induced by high dose chemoradiotherapy before autologous bone marrow transplantation (BMT).

METHODS AND MATERIALS

Between 1993 and 1995, 30 consecutive patients receiving an autologous peripheral stem-cell or bone marrow transplant (BMT) after high dose chemoradiotherapy were randomized to possibly receive prophylactic laser to the oral mucosa after giving informed consent. Chemotherapy consisted of cyclophosphamide, 60 mg/kg intravenously (I.V.) on day (d)-5 and d-4 in 27 cases, or melphalan 140 mg/kg I.V. on d-4 in three cases. Total body irradiation (TBI) consisted of 12 Gy midplane dose in six fractions (4 Gy/day for three days). He-Ne laser (632.8 nm wavelength, power 60 mW) applications were performed daily from d-5 to d-1 on five anatomic sites of the oral mucosa. Oral examination was performed daily from d0 to d + 20. Mucositis was scored according to an oral exam guide with a 16 item scale of which four were assessed by the patients themselves. Mean daily self assessment scores for oral pain, ability to swallow and oral dryness were measured. A daily mucositis index (DMI) and a cumulative oral mucositis score (COMS) were established. Requirement for narcotics and parenteral nutrition was recorded.

RESULTS

The COMS was significantly reduced among laser treated (L+) patients (p = 0.04). The improvement of DMI in L+ patients was also statistically significant (p < 0.05) from d + 2 to d + 7. Occurrence and duration of grade III oral mucositis were reduced in L+ patients (p = 0.01). Laser applications reduced oral pain as assessed by patients (p = 0.05) and L+ patients required less morphine (p = 0.05). Xerostomia and ability to swallow were improved among the L+ patients (p = 0.005 and p = 0.01, respectively). Requirement for parenteral nutrition was not reduced (p = NS).

CONCLUSION

Helium-Neon laser treatment was well tolerated, feasible in all cases, and reduced high dose chemoradiotherapy-induced oral mucositis. Optimal laser treatment schedules still needs to be defined.

A wheat HMW glutenin subunit gene reveals a highly repeated structure

A wheat genomic library was screened with two synthetic oligonucleotides (24 and 25 bases in length) complementary to a partial cDNA clone encoding a glutenin gene [Thompson et al. (1983) Theor. Appl. Genet. 67, 87-96]. Glutenins are large molecular weight aggregated proteins of grain endosperm, and major determinants of bread making quality of wheat. Of the two clones obtained one was fully characterized. It contained the sequence of the high molecular weight subunit of glutenin. The amino acid sequence derived from the gene sequence reveals a mature protein (817 amino acids) with a highly repeated structure of two different motifs corresponding to the high glutamine (35.7%), glycine (20.1%) and proline (13.1%) content. The gene does not contain an intron, and possesses a typical eukaryotic promoter; the RNA initiation site is 25-30 bases downstream.

Soluble and membrane-bound forms of signaling lymphocytic activation molecule (SLAM) induce proliferation and Ig synthesis by activated human B lymphocytes

In this study it is shown that both membrane-bound and soluble forms of signaling lymphocytic activation molecule (SLAM) induce proliferation and Ig synthesis by activated human B cells. Activated B cells express the membrane-bound form of SLAM (mSLAM), the soluble (s) and the cytoplasmic (c) isoforms of SLAM, and the expression levels of mSLAM on B cells are rapidly upregulated after activation in vitro. Importantly, recombinant sSLAM and L cells transfected with mSLAM efficiently enhance B cell proliferation induced by anti-mu mAbs, anti-CD40 mAbs or Staphylococcus aureus Cowan I (SAC) in the presence or absence of IL-2, IL-4, IL-10, IL-12, or IL-15. sSLAM strongly enhances proliferation of both freshly isolated B cells and B cells derived from long-term in vitro cultures, indicating that SLAM acts not only during the initial phase of B cell activation but also during the expansion of preactivated B cells. In addition, sSLAM enhances production of IgM, IgG, and IgA by B cells activated by anti-CD40 mAbs. SLAM has recently been shown to be a high affinity self-ligand, and the present data suggest that signaling through homophilic SLAM-SLAM binding during B-B and B-T cell interactions enhances the expansion and differentiation of activated B cells.

OB-BP1/Siglec-6. a leptin- and sialic acid-binding protein of the immunoglobulin superfamily

We report the expression cloning of a novel leptin-binding protein of the immunoglobulin superfamily (OB-BP1) and a cross-hybridizing clone (OB-BP2) that is identical to a recently described sialic acid-binding I-type lectin called Siglec-5. Comparisons to other known Siglec family members (CD22, CD33, myelin-associated glycoprotein, and sialoadhesin) show that OB-BP1, OB-BP2/Siglec-5, and CD33/Siglec-3 constitute a unique related subgroup with a high level of overall amino acid identity: OB-BP1 versus Siglec-5 (59%), OB-BP1 versus CD33 (63%), and OB-BP2/Siglec-5 versus CD33 (56%). The cytoplasmic domains are not as highly conserved, but display novel motifs which are putative sites of tyrosine phosphorylation, including an immunoreceptor tyrosine kinase inhibitory motif and a motif found in SLAM and SLAM-like proteins. Human tissues showed high levels of OB-BP1 mRNA in placenta and moderate expression in spleen, peripheral blood leukocytes, and small intestine. OB-BP2/Siglec-5 mRNA was detected in peripheral blood leukocytes, lung, spleen, and placenta. A monoclonal antibody specific for OB-BP1 confirmed high expression in the cyto- and syncytiotrophoblasts of the placenta. Using this antibody on peripheral blood leukocytes showed an almost exclusive expression pattern on B cells. Recombinant forms of the extracellular domains of OB-BP1, OB-BP2/Siglec-5, and CD33/Siglec-3 were assayed for specific binding of leptin. While OB-BP1 exhibited tight binding (K(d) 91 nM), the other two showed weak binding with K(d) values in the 1-2 microM range. Studies with sialylated ligands indicated that OB-BP1 selectively bound Neu5Acalpha2-6GalNAcalpha (sialyl-Tn) allowing its formal designation as Siglec-6. The identification of OB-BP1/Siglec-6 as a Siglec family member, coupled with its restricted expression pattern, suggests that it may mediate cell-cell recognition events by interacting with sialylated glycoprotein ligands expressed on specific cell populations. We also propose a role for OB-BP1 in leptin physiology, as a molecular sink to regulate leptin serum levels.

Limited humoral immunity in hepatitis C virus infection

BACKGROUND & AIMS

The extremely high rate of chronicity to hepatitis C virus (HVC) infection suggests an inefficient immune response. The humoral immune response to HCV was evaluated in 60 patients with chronic HCV infection and in 12 patients acutely infected with HCV.

METHODS

A number of recombinant HCV antigens including the core, envelope 2 (E2), nonstructural (NS) 3, NS4, and NS5 proteins, and NS4a and E2-HVR-1 peptides were used in enzyme-linked immunoassays.

RESULTS

Immunoglobulin (Ig) G antibody responses to these viral antigens, except for the HCV core, were highly restricted to the IgG1 isotype. The prevalence of antibodies of the IgG1 isotype specific for the HCV core, E2, E2-HVR1, NS3 (helicase domain), NS4, and NS5 antigens was 97%, 98%, 28%, 88%, 33%, and 68%, respectively. Antibodies of the IgG3 isotype specific for E2, E2-HVR-1, NS3, NS4, and NS5 were detected in a minority of serum samples. The IgG2 and IgG4 isotypes were rarely if ever detected. Furthermore, antibody responses to HCV viral antigens were of relatively low titer and, with the exception of anti-HCV core, were delayed in appearance until the chronic phase of infection.

CONCLUSIONS

The IgG1 restriction, low titer, and delayed appearance of antibody responses elicited during HCV infection suggest that the immunogenicity of HCV proteins is limited in the context of natural infection. Inasmuch as recombinant HCV viral antigens perform as relatively normal immunogens in small animals, we suggest that the defective humoral immune responses during HCV infection may be attributable to an "immune avoidance" strategy.

Dietary tocotrienols reduce concentrations of plasma cholesterol, apolipoprotein B, thromboxane B2, and platelet factor 4 in pigs with inherited hyperlipidemias

Normolipemic and genetically hypercholesterolemic pigs of defined lipoprotein genotype were fed a standard diet supplemented with 50 micrograms/g tocotrienol-rich fraction (TRF) isolated from palm oil. Hypercholesterolemic pigs fed the TRF supplement showed a 44% decrease in total serum cholesterol, a 60% decrease in low-density-lipoprotein (LDL)-cholesterol, and significant decreases in levels of apolipoprotein B (26%), thromboxane-B2 (41%), and platelet factor 4 (PF4; 29%). The declines in thromboxane B2 and PF4 suggest that TRF has a marked protective effect on the endothelium and platelet aggregation. The effect of the lipid-lowering diet persisted only in the hypercholesterolemic swine after 8 wk feeding of the control diet. These results support observations from previous studies on lowering plasma cholesterol in animals by tocotrienols, which are naturally occurring compounds in grain and palm oils and may have some effect on lowering plasma cholesterol in humans.

Helium-neon laser effects on conditioning-induced oral mucositis in bone marrow transplantation patients

BACKGROUND

Oral mucositis is a common complication of bone marrow transplantation (BMT) conditioning therapy. Sequelae consist of increased risk for infection, moderate to severe pain, compromised oral function, and bleeding. This study investigated helium-neon laser treatment for prevention of conditioning-induced oral mucositis in BMT patients. Patterns and severity of mucositis for specific conditioning drug regimens also were analyzed.

METHODS

Twenty patients received laser radiation to their oral mucosa, either left or right of midline. The contralateral side was sham-treated and served as a control. Mucositis severity was scored independently by two modified versions of the Oral Mucositis Index Scale (OMI-A and OMI-B) and the Eastern Cooperative Oncology Group (ECOG) Oral Toxicity Scale; pain severity was scored by subjects on a visual analogue scale (VAS). Cumulative scores were analyzed for differences between the laser-treated and sham-treated sides.

RESULTS

Oral mucositis and pain scores were significantly lower for the treated versus the untreated side by OMI-A and B (P < 0.005) and VAS (P = 0.027) criteria, respectively. Ulcerative lesions occurred in all patients bilaterally; severity increased until Day +6, and lesions resolved by Day +21. Mucositis was more severe for patients conditioned with busulfan/carboplatin/thiotepa than for patients conditioned with busulfan/cyclophosphamide/etoposide.

CONCLUSIONS

Helium-neon laser treatment was well-tolerated and reduced the severity of conditioning-induced oral mucositis in BMT patients.

Oral manifestations of chronic graft-v-host disease

Sixty patients were studied 180 to 500 days after allogeneic marrow transplantation to determine if late oral abnormalities were associated with the presence of chronic graft-v-host disease (GVHD). Lip and intraoral mucosal surfaces were evaluated for color, keratinization, atrophy, and erythema. Subjective complaints of oral pain and xerostomia were also recorded. Abnormalities were scored on a scale of 0 to 3 and tested for association with GVHD by chi 2 test. Oral manifestations most strongly associated with chronic GVHD included atrophy and erythema or lichenoid lesions of the buccal and labial mucosa and oral pain. Oral manifestations resembled several naturally occurring autoimmune disorders. Recognition of these changes can aid in the clinical diagnosis and assessment of established chronic GVHD.

Variation in the frequency and type of sperm chromosomal abnormalities among normal men

The chromosomal constitution of 1582 human sperm from 30 normal men of proven fertility was investigated after sperm penetration of hamster eggs. A minimum of 30 sperm chromosome complements were analysed per donor so that the distribution and variation in the frequency and type of sperm chromosomal abnormalities could be assessed. The mean frequency of sperm chromosomal abnormalities in individual men was 10.4% (+/- 6.0%) with a range of 0-24.7%. For numerical abnormalities the mean was 4.7% (+/- 2.9%) with a range of 0-10% and for structural abnormalities the mean was 6.2% (+/- 6.0%) with a range of 0-23.1%. The 95% confidence intervals for the mean of an individual male were 0-10.5% for numerical abnormalities, 0-18.2% for structural abnormalities, and 0-22.4% for total abnormalities. There was a significant excess of hypohaploid complements compared with hyperhaploid complements. Since hypohaploid complements could be caused by technical artefact, a conservative estimate of aneuploidy was obtained by doubling the frequency of hyperhaploid sperm, yielding an estimate of 2.4% aneuploidy. The proportion of X-bearing (53%) and Y-bearing (47%) sperm did not differ significantly. These results were compared to the other two large studies of sperm chromosome complements from normal men.

Genetics/epigenetics of oral premalignancy: current status and future research

Squamous cell carcinoma (SCC) of the oral and oropharyngeal region is the sixth most common malignancy in the world today. Despite numerous advances in treatment, long-term survival from this disease remains poor. Early detection can decrease both morbidity and mortality associated with this neoplasm. However, screening for potentially malignant disease is typically confounded by difficulty in discriminating between reactive/inflammatory lesions vs those lesions that are premalignant in nature. Furthermore, the histologic diagnosis of dysplasia can be subjective and is thus prone to a considerable range of interpretation. Similarly, no definitive, validated criteria exist for predicting which dysplastic lesions are most likely to progress to cancer over time. Given this state of science, the presence of dysplasia can only be used to indicate that an oral lesion may have an increased risk of malignant transformation. Molecular biomarkers capable of identifying the subset of lesions likely to progress to cancer are required to eliminate this clinical diagnostic dilemma. The purpose of this review is to assess the current state of knowledge regarding genetic/epigenetic alterations observed in oral mucosal premalignancy. In addition, recommendations for future research studies directed at defining the predictive capacity of specific biomarkers in this modeling are presented.

Using high throughput sequencing to explore the biodiversity in oral bacterial communities

High throughput sequencing of 16S ribosomal RNA gene amplicons is a cost-effective method for characterization of oral bacterial communities. However, before undertaking large-scale studies, it is necessary to understand the technique-associated limitations and intrinsic variability of the oral ecosystem. In this work we evaluated bias in species representation using an in vitro-assembled mock community of oral bacteria. We then characterized the bacterial communities in saliva and buccal mucosa of five healthy subjects to investigate the power of high throughput sequencing in revealing their diversity and biogeography patterns. Mock community analysis showed primer and DNA isolation biases and an overestimation of diversity that was reduced after eliminating singleton operational taxonomic units (OTUs). Sequencing of salivary and mucosal communities found a total of 455 OTUs (0.3% dissimilarity) with only 78 of these present in all subjects. We demonstrate that this variability was partly the result of incomplete richness coverage even at great sequencing depths, and so comparing communities by their structure was more effective than comparisons based solely on membership. With respect to oral biogeography, we found inter-subject variability in community structure was lower than site differences between salivary and mucosal communities within subjects. These differences were evident at very low sequencing depths and were mostly caused by the abundance of Streptococcus mitis and Gemella haemolysans in mucosa. In summary, we present an experimental and data analysis framework that will facilitate design and interpretation of pyrosequencing-based studies. Despite challenges associated with this technique, we demonstrate its power for evaluation of oral diversity and biogeography patterns.