Effect of onychomycosis on quality of life

BACKGROUND

Onychomycosis impairs normal nail functions, causes considerable pain, interferes with daily activities, and has negative psychosocial effects.

OBJECTIVE

Our purpose was to determine patients' perception of onychomycosis on the quality of life.

METHODS

A total of 258 patients with confirmed onychomycosis were surveyed by telephone at three centers. Responses to a standardized quality-of-life questionnaire were analyzed for patient demographics, physical and functional impact, psychosocial impact, and economic impact.

RESULTS

Highest positive responses were nail-trimming problems (76%), embarrassment (74%), pain (48%), nail pressure (40%), and discomfort wearing shoes (38%). Ability to pick up small objects was impaired in 41% of subjects with fingernail involvement. More than 58 onychomycosis-related sick days and 468 medical visits (1.8 per subject) were reported during a 6-month period.

CONCLUSION

Onychomycosis has significant social, psychologic, health, and occupational effects. Relevance of quality-of-life issues to overall health, earning potential, and social functioning should prompt reconsideration of the value of aggressive treatment of and financial coverage for onychomycosis.

Malignant epithelial tumors of the lacrimal gland: a clinicopathologic study of 21 cases

OBJECTIVE

To analyze 120 lacrimal gland masses collected during a 23-year period in the Ophthalmic Pathology Laboratory at the Cullen Eye Institute, Houston, Tex.

METHODS

Of the 120 lacrimal gland tumors, we focused on a detailed clinicopathologic study of 21 malignant epithelial tumors. Follow-up was available in 19 (90%) of 21 cases.

RESULTS

About two thirds of the masses (75 cases) were inflammatory, one third (41 cases) were of epithelial origin, and 3% (4 cases) were malignant lymphomas. Of the epithelial tumors, 17 (41%) were benign mixed tumors, 12 (29%) were adenoid cystic carcinomas arising de novo, 2 (5%) were adenocarcinoma arising de novo, 7 (17%) were malignant mixed tumors, and 3 (7%) were metastatic carcinoma. All of the patients with adenoid cystic carcinoma had local recurrences, and 60% of the patients died of their tumors (mean survival, 5 years); only 2 patients were alive 13 and 16 years after the initial surgery, both of whom had radical surgical procedures for recurrence following orbital exenteration.

CONCLUSION

The histopathologic classification and management of these tumors are discussed. This study supports the dismal prognosis of adenoid cystic carcinoma arising de novo.

Isolation and initial characterisation of complement components C3 and C4 of the nurse shark and the channel catfish

Complement components C3 and C4 have been isolated from the serum of the nurse shark (Ginglymostoma cirratum) and of the channel catfish (Ictalurus punctatus). As in the higher vertebrates, the fish C4 proteins have three-chain structures while the C3 proteins have two-chain structures. All four proteins have intra-chain thioesters located within their highest molecular mass polypeptides. N-terminal sequence analysis of the polypeptides has confirmed the identity of the proteins. In all cases except the catfish C3 alpha-chain, which appears to have a blocked N-terminus, sequence similarities are apparent in comparisons with the chains of C3 and C4 from higher vertebrates. We have confirmed that the activity/protein previously designated C2n is the nurse shark analogue of mammalian C4. This is the first report of structural evidence for C4 in both the bony and cartilaginous fish.

Outpatient geriatric evaluation and management

OBJECTIVE

To describe the development and operation of a practical model of outpatient geriatric evaluation and management (GEM) for high-risk, community-dwelling older adults.

PARTICIPANTS

Community-dwelling Medicare beneficiaries age 70 years and older who were medically stable but had a high probability of repeated admission to hospitals (P(ra) > .40) in the future (n = 248).

INTERVENTION

Outpatient GEM.

MEASUREMENTS

Demographic, clinical, and use-of-hospital characteristics of patients; nature and quantity of GEM services; satisfaction of patients and their established primary physicians.

RESULTS

At enrollment, the average patient was 78.7 years old, took 5.0 long-term prescription medications and was unable to perform 0.5 (of six) activities of daily living (ADL) and 1.4 (of seven) instrumental ADL. Many patients (71.3%) reported hospital days during the previous year. Each of three interdisciplinary teams (geriatrician, gerontological nurse practitioner, nurse and social worker) performed comprehensive assessments and then provided primary care and case management to a case load of 45 to 52 patients. On average, GEM required 6 months, during which patients visited the GEM clinic 7.4 times, had 10.4 active problems addressed, spoke to GEM staff members weekly by telephone, and were referred to two other providers. Most patients (94.4%) completed the GEM program; 66.7% completed advance directives. Satisfaction with GEM was high among the patients and their established primary physicians. The cost of the GEM personnel averaged about $1540 per patient treated.

CONCLUSIONS

This model of outpatient GEM provided 6 months of targeted intensive care at a reasonable cost. The satisfaction ratings of patients and their primary physicians were high.

Evaluation of the human hair root for DNA typing subsequent to microscopic comparison

Telogen human hairs are one of the most common useful evidence findings at crime scenes and/or on homicide victims. Occasionally, the microscopic characterization of the found telogen hair is the only physical evidence association to a victim or suspect. Recently efforts to characterize these hairs by mitochondrial DNA (mtDNA) methods have progressed. The nature of the telogen hair root morphology and ultrastructure has, however, been largely ignored. Examiners have recognized these hairs are unlikely to be typable by nuclear DNA (nuDNA) methods. Most forensic biologists have little knowledge of the complex cellular composition of anagen, catagen, and telogen hair roots or their morphogenesis. This paper reviews ex situ human hair root morphology as it relates to the likelihood of successful nuclear DNA typing. Dermatology texts of hair root morphology always demonstrate their microscopic appearance in the skin. This study investigates the use of fluorescence in situ hybridization (FISH) methods to sex type telogen head hairs, and it further investigates hair root morphology as it relates to the potential nuclear DNA content of evidence hairs. There is a need for the use of appropriate, consensus terminology for describing hair root morphology. There is also a need for standardized laboratory light microscopic methods in evaluating a hair root for DNA typing. FISH was found to be an unsuitable technique for sex determination of telogen hair clubs. It was determined that anagen/catagen hair roots without translucent sheath material are excellent candidates for nuDNA PCR-based typing and that hairs with telogen club root material only should not be submitted for nuDNA typing attempts.

Psychotherapeutic agents in older adults. Compliance: problems and opportunities

Many studies have demonstrated the problems patients have with medications. In these studies, the elderly and patients utilizing psychiatric medications are often cited as having the greatest noncompliance. This article reviews the extent of noncompliance in this population and the effect of noncompliance on disease management. Factors related to the health care provider, the patient, and the type of therapy that lead to noncompliance are reviewed. Opportunities and intervention techniques are provided to improve patient outcomes.

Hand-assisted laparoscopic splenectomy for isolated splenic metastasis from an ovarian carcinoma: a case report with review of the literature

A 56-year-old woman was found to have a solitary metastasis to the spleen from ovarian cancer. A hand-assisted laparoscopic splenectomy was carried out. The operative technique and advantages of this technique are discussed. Laparoscopy with mini laparotomy allows for manual manipulation of the spleen with the ability to control bleeding, and facilitates mobilization and removal of the specimen. Postoperative recovery is rapid. Review of the literature indicates that secondary metastasis to the spleen is quite common.

[Laparoscopic antireflux procedures]

Laparoscopic antireflux surgery is rapidly replacing traditional operations for the treatment of medically refractory gastroesophageal reflux disease. These procedures are technically demanding. Troublesome side effects can be minimized by carefully selecting patients and using a meticulous and appropriate technique. Extensive follow-up data are now emerging and indicate that these procedures can offer long-term control of symptoms with few permanent side effects.

Identification of the leader-body junctions for the viral subgenomic mRNAs and organization of the simian hemorrhagic fever virus genome: evidence for gene duplication during arterivirus evolution

Simian hemorrhagic fever virus (SHFV) was recently reclassified and assigned to the new virus family Arteriviridae. During replication, arteriviruses produce a 3' coterminal, nested set of subgenomic mRNAs (sgRNAs). These sgRNAs arise by discontinuous transcription, and each contains a 5' leader sequence which is joined to the body of the mRNA through a conserved junction sequence. Only the 5'-most open reading frame (ORF) is believed to be transcribed from each sgRNA. The SHFV genome encodes nine ORFs that are presumed to be expressed from sgRNAs. However, reverse transcription-PCR analysis with leader- and ORF-specific primers identified only eight sgRNA species. The consensus sequence 5'-UCNUUAACC-3' was identified as the junction motif. Our data suggest that sgRNA 2 may be bicistronic, expressing both ORF 2a and ORF 2b. SHFV encodes three more ORFs on its genome than the other arteriviruses. Comparative sequence analysis suggested that SHFV ORFs 2a, 2b, and 3 are related to ORFs 2 through 4 of the other arteriviruses. Evidence which suggests that SHFV ORFs 4 through 6 are related to ORFs 2a through 3 and may have resulted from a recombination event during virus evolution is presented.

Management of ingested foreign bodies within the appendix: a case report with review of the literature

A case is reported of an elective appendectomy in a patient with known ingestion of a sharp foreign body. The metal drill bit was ingested unintentionally 3 months before presentation at our institution. Plain abdominal films demonstrated the foreign body in the right lower abdominal quadrant. Because the gold dental drill bit was sharp and thought to be lodged in the terminal ileum or cecum, an attempt was made to remove the object during colonoscopy. This attempt was unsuccessful because no drill bit could be detected in the colon or terminal ileum. A laparoscopic exploration was performed, and the foreign body was found to lie in the appendix, after bowel manipulation under fluoroscopic guidance and with direct laparoscopic visualization. A laparoscopic assisted appendectomy was performed. On pathologic examination the drill bit was embedded in the tip of the appendix with signs of intramucosal acute inflammation. Management and indication for surgery of foreign bodies in the appendix are discussed, and we review the related literature. This is the second reported case of a dental drill bit in the appendix causing appendicitis.

Factors that predict malignant thyroid lesions when fine-needle aspiration is "suspicious for follicular neoplasm"

OBJECTIVE

To assess clinical factors that may improve the ability to predict the presence of a malignant lesion in thyroid nodules that are found to be "suspicious for follicular neoplasm" by fine-needle aspiration (FNA) cytology.

MATERIAL AND METHODS

We undertook a retrospective review of the medical records of all patients at the three Mayo Clinic facilities who underwent a thyroid surgical procedure between January 1992 and December 1994 and had a preoperative FNA report of "suspicious for follicular neoplasm." Patient and nodule characteristics were analyzed statistically for associations with the presence of cancer.

RESULTS

The study cohort consisted of 219 patients with a mean age of 54.3 years. Eighty-four percent of resections were done for benign disease. Of the 35 malignant lesions, 9 were incidental papillary cancers separate from the primary nodule; thus, only 26 cancers were found in the index nodule, and only 19 (9% of the total group) were follicular carcinomas. Clinical findings associated with a malignant index nodule were larger diameter, fixation of the mass, and younger age of the patient.

CONCLUSION

Clinical characteristics may be used for more accurate assessment of the risk of the presence of a malignant lesion when FNA cytology of a thyroid nodule is reported as "suspicious for follicular neoplasm."

Management of the failed antireflux operation

A further operation is required in a small proportion of patients who have had prior antireflux surgery. This has a surprisingly good chance for success in appropriately evaluated patients. The surgeon must make very specific decisions regarding the surgical approach. The use of laparoscopy for redo surgery is being defined.

In vivo antiviral activity and pharmacokinetics of (-)-cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine in woodchuck hepatitis virus-infected woodchucks

The (-) enantiomer of cis-5-fluoro-1l-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine [(-)-FTC)], a substituted oxathiolane compound with anti-hepatitis B virus activity in vitro, was assessed for its efficacy in woodchucks with naturally acquired woodchuck hepatitis virus (WHV) infection. Pharmacokinetics and in vitro anabolism were also determined. (-)-FTC was anabolized to the 5'-triphosphate in a dose-related fashion, reaching a maximum concentration at about 24 h in cultured woodchuck hepatocytes. Following administration of a dose of 10 mg/kg of body weight intraperitoneally (i.p.), the clearance of (-)-FTC from plasma was monoexponential, the terminal half-life was 3.76 +/- 1.4 h, and the systemic clearance was 0.12 +/- 0.06 liters/h/kg. The antiviral efficacy of (-)-FTC in the woodchuck model was assessed by quantitation of serum WHV DNA levels and by WHV particle-associated DNA polymerase activity at two dosages, 30 and 20 mg/kg given i.p. twice daily (b.i.d.), respectively. The level of WHV DNA in serum was reduced 20- to 150-fold (average, 56-fold) in the 30-mg/kg-b.i.d. treatment group and 6- to 49-fold (average, 27-fold) in the 20-mg/kg-b.i.d. treatment group. Viral DNA polymerase levels diminished accordingly. One week after treatment was discontinued, WHV levels returned to pretreatment levels in both studies. These animals were biopsied before and following treatment with 30 mg of (-)-FTC per kg. Their livers were characterized by a mild increase in cytoplasmic lipid levels, but this change was not associated with altered liver enzyme levels. Serum chemistry and hematology results were within the normal ranges for all treated animals. We conclude that (-)-FTC is a potent antihepadnaviral agent and that it has no detectable toxic effects in woodchucks when given for up to 25 days. Further development of (-)-FTC as an anti-hepatitis B virus therapy for patients is warranted.

A description of general health risks in adult liver transplant recipients

The focus of posttransplant care and clinical research has been on the management of rejection and short-term side effects associated with immunosuppressive therapy. Long-term side effects have only recently been recognized as potential health problems in liver transplant recipients. The aim of this pilot study was to determine the feasibility of using the Healthier People Version 4.0 Health Risk Appraisal as a tool for identifying existing and potential risk factors for premature disease and death among asymptomatic liver transplant recipients and to describe health risks in adult liver transplant recipients. The sample consisted of 50 adult first-time liver transplant recipients. It was found that this tool highlights health risks affecting life expectancy and pinpoints risks that an individual can control. It also provides practitioners with information necessary to design appropriate prevention and health promotion strategies to assure better health and quality of life for patients following liver transplantation.

Neutrophil maturation of CD34+ cells from peripheral blood and bone marrow in serum-free culture medium with PIXY321 and granulocyte-colony stimulating factor (G-CSF)

Bone marrow (BM) or peripheral blood (PB) CD34+ cells were cultured for 12 days in serum-free culture medium containing PIXY321 (IL-3/ GM-CSF fusion protein) with or without periodic supplements of granulocyte-colony stimulating factor (G-CSF). The cultures were evaluated at day 12 for total cell proliferation (fold increase from day 0), neutrophil differentiation by flow cytometry, using dual staining with CD15-FITC and CD11b-PE, and morphology using Wright-Giemsa and granule staining. In cultures containing PIXY321 where 6000 U/ml of G-CSF was added days 0 and 6, there was no significant difference (p > or = 0.05) in cell proliferation or the percent of CD15+/CD11b+ cells when compared with cultures with PIXY321 alone. ELISA analysis showed G-CSF levels had declined by 90% after 3 days of culture. Further studies were performed to assess the benefit of supplementing lower concentrations of G-CSF (600 U/ml) at more frequent intervals. A significant increase (p < or = 0.05) in cell proliferation and percent CD15+/CD11b+ was observed when G-CSF was added on days 0, 3, 6, and 9 (every 3 days) as compared with those cultures with PIXY321 alone. CD34+ cell proliferation without G-CSF was 19.6 +/- 4.8-fold, with G-CSF added on days 0 and 6 was 28.7 +/- 6.4-fold, and with G-CSF added on days 0, 3, 6, and 9 was 45.9 +/- 10.6-fold. Percent of CD15+/CD11b+ cells was 19.0 +/- 4.6%, 38.2 +/- 7.2%, and 58.5 +/- 6.5%, respectively, in these cultures. We observed more CD15+/CD11b+ cells, myelocytes/metamyelocytes, and secondary granule staining in cultures with G-CSF added on day, 0, 3, 6, and 9 as compared with cultures with G-CSF added on days 0 and 6 or no G-CSF added. We conclude that PIXY321 and G-CSF act synergistically on the in vitro proliferation and neutrophil differentiation of BM and PB CD34+ cells and that frequent supplements of G-CSF facilitate neutrophil differentiation.

Laparoscopic paraesophageal hernia repair

BACKGROUND

Paraesophageal hernias require surgery to avoid potentially serious complications.

OBJECTIVE

To evaluate paraesophageal hernia repair using the laparoscopic approach.

DESIGN

Case series.

SETTING

University hospital and foregut testing laboratory.

SUBJECTS

Sixty-five consecutive patients (mean age, 63.6 years; range, 26-90 years). Preoperative evaluation included barium esophagogram, endoscopy, esophageal manometry, and 24-hour pH monitoring.

OUTCOME MEASURES

Operative complications, postoperative morbidity, follow-up symptoms (53 patients; mean, 18 months; range, 2-54 months) and barium esophagogram (46 patients).

RESULTS

Fifty-six patients (86%) had a type III hernia and 9 (14%) had a type II hernia. Twenty (65%) of 31 patients who underwent pH monitoring had a positive 24-hour pH score, and 24 (56%) of 43 patients who underwent manometry had an incompetent lower esophageal sphincter. Four patients had a gastric volvulus and 21 patients had more than 50% of their stomach in the chest. All patients underwent hernia reduction, crural repair, and fundoplication (64 Nissen procedures and 1 Toupet procedure). The average duration of surgery was 2 hours. There were 2 conversions: gastric perforation and a difficult dissection because of a large fibrotic sac. Other complications, all managed intraoperatively, were 2 gastric perforations and bleeding in 6 patients. Average length of hospital stay was 2 days (range, 1-23 days). Early re-operation was required in 3 patients: slipped Nissen; small-bowel obstruction due to trocar-site hernia; and organo-axial rotation with gastroduodenal obstruction. Four patients required esophageal dilatation after surgery. Forty-nine of 53 patients available for long-term follow-up were satisfied with the results of surgery. Time to full recovery was 3 weeks (range, 1 week to 2 months). Seven of 46 patients experienced small type I hernias observed on routine follow-up esophagograms.

CONCLUSIONS

Most paraesophageal hernias are type III. A concomitant antireflux procedure is recommended. Paraesophageal hernias can be managed successfully by the laparoscopic route with good outcome.

Pyrrolopyrimidines: novel brain-penetrating antioxidants with neuroprotective activity in brain injury and ischemia models

A novel group of antioxidant compounds, the pyrrolopyrimidines, has been discovered recently. Many of these possess significantly improved oral bioavailability (56-70% in rats), increased efficacy and potency in protecting cultured neurons against iron-induced lipid peroxidative injury and as much as a 5-fold increase in brain uptake compared with the 21-aminosteroid antioxidant compound, tirilazad mesylate (U-74006F), described earlier. They appear to quench lipid peroxidation reactions by electron-donating and/or radical-trapping mechanisms. Several compounds in the series, such as U-101033E and U-104067F, demonstrate greater ability than tirilazad to protect the hippocampal CA1 region in the gerbil transient (5-min) forebrain ischemia model. Delaying treatment until 4 hr after the ischemic insult still results in significant CA1 neuronal protection. U-101033E is still effective in salvaging a portion of the CA1 neuronal population when the ischemic duration is extended to 10 min. In addition, U-101033E has been found to be protective in the context of focal cerebral ischemia, reducing infarct size in the mouse permanent middle cerebral artery occlusion model, in contrast to tirilazad which is minimally effective. These results suggest that antioxidant compounds with improved brain parenchymal penetration are better able to limit certain types of ischemic brain damage than those which are localized in the cerebral microvasculature. However, the activity of U-101033E in improving early post-traumatic recovery in mice subjected to severe concussive head injury is similar to that of tirilazad. Last, the oral bioavailability of many pyrrolopyrimidines suggests that they may be useful for certain chronic neurodegenerative disorders in which lipid peroxidation plays a role.

Metabolic bone disease in very-low-birth-weight infants: assessment, prevention, and treatment by neonatal nurse practitioners

OBJECTIVE

To describe the current practice of neonatal nurse practitioners in assessing skeletal health and preventing and treating metabolic bone disease in very-low-birth-weight infants.

DESIGN

Descriptive, retrospective survey.

PARTICIPANTS

Neonatal nurse practitioners in the continental United States were systematically randomly selected. A 64% response rate was obtained (112).

MAIN OUTCOME MEASURES

Responses to questions about assessing skeletal health and preventing and treating metabolic bone disease in very-low-birth-weight infants.

RESULTS

Current practice of neonatal nurse practitioners includes assessing skeletal health of very-low-birth-weight infants on the 7th (47.3%) or 14th (19.6%) day of life, with subsequent assessments every 7 (63.3%) or 14 (18.8%) days. Neonatal nurse practitioners (85.1%) estimate the incidence of metabolic bone disease at less than 15%. Neonatal nurse practitioners initiate total parenteral nutrition (99%), provide parenteral calcium and phosphorous in ratios of 1.3-1.7:1 (9%), and add powdered fortifier (90.1%) and liquid fortifier (25.2%) to expressed breast milk. All respondents use formulas made for premature infants. Physical therapy is used by 46.8% of neonatal nurse practitioners.

CONCLUSIONS

Neonatal nurse practitioners underestimate the incidence of metabolic bone disease. Parenteral calcium and phosphorous are given but in quantities that differ from the recommended ratio. Most neonatal nurse practitioners use formulas made for premature infants and add powdered fortifier to expressed breast milk. Although physical therapy is prescribed, more research on its effect on bone mineralization is warranted before this practice is recommended without reservation.

Locomotor head-trunk coordination strategies following space flight

During locomotion, angular head movements act in a compensatory fashion to oppose the vertical trunk translation that occurs during each step in the gait cycle. This coordinated strategy between head and trunk motion serves to aid gaze stabilization and perhaps simplifies the sensory coordinate transformation between the head and trunk, allowing efficient descending motor control during locomotion. Following space flight, astronauts often experience oscillopsia during locomotion in addition to postural and gait instabilities, suggesting a possible breakdown in head-trunk coordination. The goal of the present investigation was to determine if exposure to the microgravity environment of space flight induces alteration in head-trunk coordination during locomotion. Astronaut subjects were asked to walk (6.4 km/h, 20 s trials) on a motorized treadmill while visually fixating on a centrally located earthfixed target positioned either 2 m (FAR) or 30 cm (NEAR) from the eyes. In addition, some trials were also performed during periodic visual occlusion. Head and trunk kinematics during locomotion were determined with the aid of a video-based motion analyzing system. We report data collected preflight (10 days prior to launch) and postflight (2 to 4 hours after landing). The coherence between pitch head and vertical trunk movements during gaze fixation of both FAR and NEAR targets was significantly reduced following space flight indicating decreased coordination between the head and trunk during postflight locomotion. Astronauts flying on their first mission showed greater alterations in the frequency spectra of pitch head movements as compared to their more experienced counterparts. These modifications in the efficacy of head movement control may account for the reported disruption in gaze performance during locomotion and may contribute to postflight postural and gait dysfunction.

Attribution of foot bones to sex and population groups

Although cranial and pelvic bones are the preferred skeletal material used by forensic anthropologists to assign unknown individuals to their most probable sex and population (racial) groups, these remains may be unavailable. This paper presents models for classification using metatarsals, proximal pedal phalanges, and the first distal phalanx of the foot. Measurements include lengths and mediolateral and dorsoplantar widths of these foot bones. Four samples of 40 individuals each (black and white males and females) comprise the dataset. Models were developed separately for right and left sides. Three models are provided for each side: a metatarsal model, a proximal phalangeal model, and a combination model involving selected metatarsal and phalangeal measurements. A stepwise discriminant procedure was used for variable selection, with some highly correlated (r > 0.85) variables subsequently removed. The metatarsal models correctly assign approximately 77-84% of individuals to their correct sex and population groups; proximal phalangeal models yield correct assignments in 70-72% of cases, and the combination models give correct classifications in 87% of cases. Models exchanging variables selected from one side for corresponding variables on the other show discriminating power ranging from approximately 67-86%. More conservative "jackknife" estimates give correct assignments in 64-82% of cases. When these models are used for classification of sex alone, 86.2-93.7% ("jackknife" range, 84.3-91.2%) of cases are correctly classified; for race alone, 78.6-96.2% ("jackknife" range, 75.5-92.4%).

Ex vivo expansion of frozen/thawed CD34+ cells isolated from frozen human apheresis products

Human CD34+ cells purified from frozen mobilized peripheral blood apheresis products (n = 7) were studied immediately (freshly isolated) or refrozen and studied after > 30 days storage in liquid nitrogen (refrozen/thawed). The proliferation and differentiation of freshly isolated or refrozen/thawed CD34+ cells were examined after 10 days of serum-supplemented suspension culture with recombinant human hematopoietic growth factors. The proliferative capacity (fold increase) of the refrozen/thawed CD34+ cells (mean +/- SD, 54.3 +/- 34.3) was comparable to the freshly isolated CD34+ cell cultures (49.0 +/- 42.4). Two-color flow cytometry of the CD34+ cultured cell populations, fresh and refrozen/thawed, displayed typical patterns of neutrophil differentiation into CD15/CD11b neutrophil precursors. The colony-forming ability of freshly isolated and refrozen/thawed CD34+ cells showed no significant differences (p > 0.05) in the total number or type of colony-forming units (CFU-GM, CFU-M, BFU-E, CFU-GEMM) obtained. In addition, the cloning efficiencies of freshly isolated (19.5 +/- 7.6%) and refrozen/thawed CD34+ cells (21.9 +/- 12.7%) were comparable (p = 0.366). These data suggest that CD34+ cells enriched from frozen apheresis blood products can be either used immediately or stored in liquid nitrogen and thawed with minimal effect on their ability to proliferate and differentiate in liquid culture.

Enhanced in vitro neurotoxicity of artemisinin derivatives in the presence of haemin

The role of haem in the neurotoxicity of artemisinin derivatives has been studied in vitro by examining neurite outgrowth measured by image analysis and cellular metabolism of the tetrazolium salt MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) measured spectrophotometrically in the neuroblastoma cell line NB2a, and by examining binding of radiolabelled dihydroartemisinin to NB2a cell and rat brain proteins. In the cases of artemether, dihydroartemisinin, and arteether, haemin (ferriprotoporphyrin IX) significantly increased the dose-related inhibition of neurite outgrowth from differentiating NB2a cells and significantly increased the dose-dependent inhibition of MTT metabolism. Inhibition of neurite outgrowth and metabolism of MTT in the presence or absence of haemin ranged from 72% to 93% and from 27% to 49% at a drug concentration of 300 nM. Haemin also significantly increased the dose-related binding of radiolabelled dihydroartemisinin to proteins from NB2a cells approximately twofold and to rat brain between three- and sixfold. Haemin did not enhance the neurotoxicity of desoxyarteether, a structural analogue of arteether with an ether linkage in the place of the endoperoxide bridge. It is suggested that haemin may catalyse the transformation of these derivatives via an interaction with the endoperoxide bridge of the artemisinin derivative to produce free radicals or electrophilic intermediates that are toxic to neuronal cells.