Determinants of the use of insecticide-treated mosquito nets in pregnant women: a mixed-methods study in Ghana.

BACKGROUND: Malaria in pregnancy remains a significant cause of morbidity and mortality, affecting the highly endemic countries of sub-Saharan Africa (SSA). Insecticide-treated nets (ITNs) are effective for malaria prevention. However, poor adherence in SSA remains a challenge. METHODS: We conducted a standard questionnaire survey among 710 pregnant women from 37 primary care clinics in the Upper West Region of Ghana from January through May 2019. Using a sequential explanatory design, we integrated the survey data from six focus group discussions with pregnant women. RESULTS: While 67% of women had some general knowledge about malaria prevention, only 19% knew the specific risks in pregnancy. Determinants of ITN use included ITN ownership (odds ratio [OR] 2.4 [95% confidence interval {CI} 1.3 to 4.4]), good maternal knowledge of the risks of malaria in pregnancy (OR 2.4 [95% CI 1.3 to 4.3]) and more antenatal care (ANC) contacts (OR 1.3 [95% CI 1.0 to 1.5)]. Focus group discussions showed that non-use of ITNs resulted from inappropriate hanging infrastructure, a preference for other malaria prevention alternatives, allergy and heat. CONCLUSIONS: Specific maternal knowledge of malaria risks in pregnancy was low and influenced the regular use of ITNs. Community and ANC-based malaria interventions should prioritize increasing knowledge of the specific risks of malaria.

Efficacy and safety of methylene blue in the treatment of malaria: a systematic review.

BACKGROUND: Methylene blue (MB) was the first synthetic antimalarial to be discovered and was used during the late 19th and early 20th centuries against all types of malaria. MB has been shown to be effective in inhibiting Plasmodium falciparum in culture, in the mouse model and in rhesus monkeys. MB was also shown to have a potent ex vivo activity against drug-resistant isolates of P. falciparum and P. vivax. In preclinical studies, MB acted synergistically with artemisinin derivates and demonstrated a strong effect on gametocyte reduction in P. falciparum. MB has, thus, been considered a potentially useful partner drug for artemisinin-based combination therapy (ACT), particularly when elimination is the final goal. The aim of this study was to review the scientific literature published until early 2017 to summarise existing knowledge on the efficacy and safety of MB in the treatment of malaria. METHODS: This systematic review followed PRISMA guidelines. Studies reporting on the efficacy and safety of MB were systematically searched for in relevant electronic databases according to a pre-designed search strategy. The search (without language restrictions) was limited to studies of humans published until February 2017. RESULTS: Out of 474 studies retrieved, a total of 22 articles reporting on 21 studies were eligible for analysis. The 21 included studies that reported data on 1504 malaria patients (2/3 were children). Older studies were case series and reports on MB monotherapy while recent studies were mainly controlled trials of combination regimens. MB was consistently shown to be highly effective in all endemic areas and demonstrated a strong effect on P. falciparum gametocyte reduction and synergy with ACT. MB treatment was associated with mild urogenital and gastrointestinal symptoms as well as blue coloration of urine. In G6PD-deficient African individuals, MB caused a slight but clinically non-significant haemoglobin reduction. CONCLUSIONS: More studies are needed to define the effects of MB in P. falciparum malaria in areas outside Africa and against P. vivax malaria. Adding MB to ACT could be a valuable approach for the prevention of resistance development and for transmission reduction in control and elimination programs. SYSTEMATIC REVIEW REGISTRATION: This study is registered at PROSPERO (registration number CRD42017062349 ).

Dynamics of dual-polarization VCSEL-based optical frequency combs under optical injection locking.

The present experimental work studies the dynamics of dual-polarization optical frequency combs (OFCs) based on gain switching (GS) vertical-cavity surface-emitting laser (VCSEL) diodes under optical injection locking (OIL). This study presents two main results. First, we have obtained an overall comb formed by two orthogonally polarized sub-combs with comparable span and power. The overall comb shows enhanced optical span and flatness and high coherence between its modes. The second result is that we have been able to control the polarization state of the overall comb by tuning the polarization state of the injected light by locking the same single teeth of the comb. This produces an overall comb with single polarization that is parallel or orthogonal. These are novel findings that provide for the development of efficient and compact OFCs based on GS VCSEL sources with versatile polarization dynamics.

Acute intermittent porphyria presenting as progressive muscular atrophy in a young black man.

Acute intermittent porphyria, the most common porphyria affecting the nervous system, typically presents with neurovisceral crises followed by a motor neuropathy. We describe a 23-year-old black South African man presenting with a progressive stuttering, lower motor neuron syndrome developing over months. He had not experienced pain or neuropsychiatric symptoms. One year after symptom onset he was bed-bound with a flaccid quadriparesis. There was marked amyotrophy, but without fasciculations. Sensation was intact apart from a hypo-aesthetic patch over the thigh. Electrophysiological investigations showed an active motor axonopathy. Urinary porphyrins, delta-aminolaevulinic acid and porphobilinogen were elevated. Mutation analysis revealed the c445C>T (R149X) mutation in the porphobilinogen deaminase gene. The patient responded dramatically to haem arginate and could walk with assistance 2 weeks later. We identified the first molecularly confirmed acute intermittent porphyria in a black South African. The clinical presentation mimicked a progressive lower motor neuron syndrome.

Temperature characteristics of surface micromachined MEMS-VCSEL with large tuning range.

Several Applications for tunable laser diodes have strict constraints in terms of overall power consumption. Furthermore, the implementation in harsh environments with large temperature fluctuations is necessary. Due to the constraint in power consumption, the application of active cooling might not be an option. For this reason we investigate the temperature characteristics of an electrically pumped MEMS-VCSEL with wide continuous wavelength tuning. For the first time, a mode hop free single mode (side mode suppression ratio (SMSR) > 40dB) tuning range of 45nm at 70°C is demonstrated with a MEMS-VCSEL. An increase of the tuning range from 85nm at 20°C to 92nm at 40°C is measured and explained. In contrast to fixed wavelength VCSEL, the investigated device shows a negative temperature induced wavelength shift of -4.5nmK(-1), which is caused by the MEMS-mirror. At 1560nm, the fibre-coupled optical output power is above 0.6mW over the entire temperature range between 20°C to 70°C and shows a maximum of > 3mW at 20°C.

Nebulized voriconazole in infections with Scedosporium apiospermum--case report and review of the literature.

Scedosporium infections are rare complications in immunocompromised patients or patients with chronic pulmonary disease. While Scedosporium prolificans is resistant to most antimycotics, Scedosporium apiospermum is usually sensitive to voriconazole and posaconazole. Pharmacokinetics and efficacy of nebulized voriconazole have been described in a murine model previously. We report for the first time the safe and effective use of nebulized voriconazole for the treatment of severe pulmonary infection with Scedosporium apiospermum in an adolescent with cystic fibrosis.

Surface micromachined tunable 1.55 µm-VCSEL with 102 nm continuous single-mode tuning.

For the first time a vertical-cavity surface-emitting laser (VCSEL) with a single-mode wavelength-tuning over 102 nm in the range of 1550 nm is demonstrated. The fiber-coupled optical output power has a maximum of 3.5 mW and is > 2 mW over the entire tuning range. The sidemode suppression ratios are > 45 dB. The wavelength tuning is achieved with the micro-electro mechanical actuation of a mirror membrane fabricated with surface micro-machining for on-wafer mass production. The mirror membrane consists of low cost dielectric materials (SiOx/SiNy) deposited with low temperature (< 100°C) Plasma Enhanced Chemical Vapor Deposition (PECVD).

The expression of protoporphyrinogen oxidase in human tissues.

Protoporphyrinogen oxidase is the penultimate enzyme in the haem biosynthetic pathway. In this study, the expression of protoporphyrinogen oxidase in a variety of human organs has been documented by immunohistochemical means at the light microscopy level in order to shed light on its inter- and intra-organ distribution. The expression varied amongst organs and the various cell types within an organ. The pattern of staining generally reflected presumed metabolic functionality and haem demand. Strongest staining was noted in hepatocytes, proximal convoluted tubules of the kidney, serous cells of the peribronchial gland in the lung, parietal cells of the stomach, tips of the villi in the small intestine and interstitial cells of the testis. Our results suggest that there are some significant sites of haem synthesis in addition to the liver and bone marrow, and should be borne in mind in studies related to haem or porphyrin dynamics and flux.

Molecular characterization of erythropoietic protoporphyria in South Africa.

BACKGROUND: Erythropoietic protoporphyria (EPP) results from a partial deficiency of ferrochelatase (FECH). Clinical expression normally requires coinheritance of a common hypomorphic FECH allele (IVS3-48C) in trans to a deleterious (primary) FECH mutation. OBJECTIVES: To characterize South African subjects with EPP, by identification and assessment of FECH sequence variations, including the IVS3-48C polymorphism. METHODS: Polymerase chain reaction amplification, single-strand conformational polymorphism analysis and restriction endonuclease analysis were employed to identify and determine the frequencies of FECH sequence variations, including the IVS3-48C polymorphism, in a study cohort of symptomatic and asymptomatic South African EPP family members, and a matched control cohort. RESULTS: We identified 29 patients from 18 families. With the exception of one family, who may represent a phenocopy of EPP, the presentation of EPP was typical. All were of European immigrant stock, and we have not identified EPP in other ethnic groups. Ten sequence variations were identified, including four apparent disease-causing mutations, the IVS3-48T/C polymorphism and five further polymorphisms. The molecular basis of EPP was established for 15 of the 17 families. A 5-bp deletion in exon 7 (757_761delAGAAG) was present in 12 of these families and haplotype studies in these families suggested a single mutational event and thus a local founder effect for this deletion. The other mutations were family specific and included two previously described splice-site mutations (IVS3+2T>G and IVS7+1G>A) and a novel 7-bp deletion in exon 4 (356_362delTTCAAGA). CONCLUSIONS: The IVS3-48C allele appears to modulate the phenotypic expression of EPP in the South African EPP cohort as observed in other populations.

Ability of mothers to diagnose fever and anaemia in their young children, in a malaria-endemic region of West Africa.

The rapid and correct diagnosis of fever and anaemia at the household level is a prerequisite for the successful management and control of life-threatening disease among young children, particularly in malaria-endemic areas of Africa. The ability of mothers to diagnose fever and anaemia in their young children has recently been explored, as part of a large, birth-cohort study in rural, north-western Burkina Faso. During a cross-sectional survey in six villages, 345 children aged, <3 years and their mothers were investigated. Each mother was asked if she considered her child to be febrile and/or anaemic before that child's temperature and haematocrit were measured, with an electronic thermometer and portable centrifuge, respectively. The recorded prevalences of fever (> or =37.5 degrees C) and anaemia (haematocrit, <25%) in the children were 12.2% and 21.4%, respectively. The mothers' diagnoses had a sensitivity of 76.2% [95% confidence interval (CI)=60.6%-88.0%] for fever and 4.1% (CI=0.8%-11.4%) for anaemia, with corresponding specificities of 87.1% (CI=82.8%-90.7%) and 95.9% (CI=92.9%-98.0%). Mothers in rural Africa appear to be fairly accurate in detecting fever in their children but less accurate in detecting anaemia. While malaria control needs to employ a mix of preventive and curative measures, anaemia control will benefit from community-based malaria-control measures as well as broader approaches addressing the nutritional status of young children.

Pyoderma gangraenosum, a rare, but potentially fatal complication in paediatric oncology patients.

Pyoderma gangraenosum (PG) is a serious chronic, ulcerative skin disorder afflicting both adults and children. As PG is often associated with systemic diseases (>50%) such as inflammatory bowel disease, rheumatoid arthritis or haematological disorders, it requires a multidisciplinary approach. This disorder is not commonly reported in paediatrics; therefore children with PG represent a particularly difficult diagnostic challenge. Clinical diagnosis is often delayed and PG is only considered after eliminating other causes of cutaneous ulcers. We report a 4-year-old boy with secondary myelodysplastic syndrome following treatment for acute lymphoblastic leukaemia who presented with a massive inflammatory, ulcerative proliferation of the lower lip which was diagnosed as PG. We have reviewed the literature with reference to diagnostic criteria and treatment options of this disorder that is particularly rare in childhood.

Conservative treatment of infantile hypertrophic pyloric stenosis with intravenous atropine sulfate does not replace pyloromyotomy.

Pyloromyotomy as described by Weber and Ramstedt has been the standard therapy for infantile hypertrophic pyloric stenosis since the 1960's and conservative therapy has been abandoned. The objective of this study was to test the effectiveness of systemic atropine applied intravenously for 7 days as a conservative therapeutic strategy and as an alternative to primary operation. Forty-two consecutive term infants with infantile hypertrophic pyloric stenosis were enrolled in the study over a period of 5 years. After confirmation of the diagnosis they all received intravenous atropine at a dose of 0.04 mg/(kg day) and increased by 0.01 mg/(kg day) up to 0.12 mg/(kg day), given as 6-8 single doses per/day. Nine pairs of parents requested that their child should be operated before completing the 7 days of medical therapy. Surgery was necessary in 8 of the remaining 33 infants (24,.2%) who did not improve after 7 days of conservative treatment. Successful treatment with i.v. atropine sulfate was achieved only in 25/33 term infants at an average maximal dose of 0.11 mg/(kg day), without any major side effects. Intravenous atropine sulfate has been considered as a potential alternative therapeutic strategy in the treatment of infantile hypertrophic pyloric stenosis. Clinical improvement however was often not seen before the 6th or 7th day of intravenous treatment. A success rate for the conservative approach of only 75% at day 7 in our study does not favour atropine therapy, in view of success rates above 95% with surgical repair.

A systematic study of the clinical and biochemical expression of variegate porphyria in a large South African family.

BACKGROUND: Variegate porphyria (VP) is an autosomal dominant disorder associated with deficient haem synthesis. Recent reports indicate that the clinical penetrance of VP may have been overestimated in studies which predated the availability of DNA-based testing for VP. OBJECTIVES: To undertake a study specifically designed to assess the clinical and biochemical penetrance of VP in a kindred characterized by gene status. METHODS: We studied a large family carrying the South African founder mutation which is known to result in almost complete haplodeficiency. All informative members were tested for the R59W mutation. Biochemical evidence of porphyria was sought by porphyrin analysis and by plasma fluorescence scanning. The presence of clinically expressed porphyria was assessed using a structured questionnaire and telephone or personal interview. RESULTS: Of 62 informative subjects, 33 had inherited the mutation. Of 28 adults, one subject had experienced a single acute attack. She and a further 10 subjects had experienced photosensitivity. The frequency of acute attacks in this family is therefore 4% (95% confidence interval, CI 1-18%), and of photosensitivity is 39.3% (95% CI 24-58%). The sensitivity and specificity of porphyrin analysis in this family were 0.46 (95% CI 0.30-0.64) and 1.00 (95% CI 0.85-1.00), respectively, and for plasma scanning the values were 0.85 (95% CI 0.58-0.96) and 1.00 (95% CI 0.72-1.00), respectively. CONCLUSIONS: The clinical penetrance of VP in our family is approximately 40%. Many more subjects with VP are diagnosed in an asymptomatic phase than previously, and the acute attack is now an uncommon manifestation of VP. Plasma scanning is more sensitive than faecal porphyrin analysis, but neither is sufficiently sensitive for the detection of carrier status.

Administration of oral activated charcoal in variegate porphyria results in a paradoxical clinical and biochemical deterioration.

BACKGROUND: Porphyrinogens are the obligate intracellular precursors of haem. These compounds are, however, unstable and are easily oxidized to the corresponding porphyrins, which are the form in which they are usually measured in the laboratory. A substantial enterohepatic cycling of porphyrins has been shown. Administration of oral activated charcoal, by interrupting this cycle, may reduce plasma and urine porphyrin levels in patients with some forms of porphyria. The effect of charcoal in subjects with variegate porphyria (VP) has not been reported. OBJECTIVES: To determine the clinical and biochemical effects of the administration of oral activated charcoal in patients with VP. METHODS: Oral activated charcoal was administered to eight subjects with VP. Clinical activity was assessed by skin lesion counts fortnightly for 6 weeks, 6 weeks after cessation of therapy, and during a subsequent 6-week control period during which no charcoal was taken. Urine and plasma porphyrins and urine precursors were measured by standard techniques. RESULTS: Treatment resulted in a significant increase in skin disease, urine and plasma porphyrins. CONCLUSIONS: Oral charcoal administration results in a paradoxical aggravation of VP, suggesting a complex and as yet undefined interaction of hepatic porphyrin metabolism and bowel porphyrin reabsorption. Oral sorbents should not be prescribed to subjects with VP.

Validation of a pencil beam model-based treatment planning system for fast neutron therapy.

Treatment planning systems (TPSs) are used to compute dose delivered to the patient. In the case of fast neutron therapy, TPSs are mostly not of general purpose but are dedicated to one facility. This is due to the few fast neutron facilities worldwide and due to the high variation in the neutron energy distributions. Efforts have been undertaken to develop a new TPS that could be applied to all the existing fast neutron facilities. The University Hospital of Essen operates a d (14 MeV) + Be fast neutron beam and the TPS used is based on an empirical model. In a previous study, the empirical model has been evolved to a pencil beam model of 35 monoenergetic neutron beams. Monte Carlo techniques have been utilized to compute distributions of the energy deposition due to primary and scattered neutrons in a simple geometry water phantom. The experimental validation of the method is now presented. Depth dose curves in water of monoenergetic neutrons have been derived from the distributions of energy deposition. The resultant depth dose curves have been utilized in order to determine the depth dose curves of the fast neutron beam of the Essen facility for the 14 radiation field sizes available in this facility. This determination requires the initial neutron spectrum. As this spectrum could not be measured at the Essen facility, the initial neutron spectrum of the Physikalisch Technische Bundesanstalt, Braunschweig, Germany, which operates the same cyclotron, was used. The calculated depth dose curves were compared to experimental depth dose curves that have been obtained in water at the University Hospital of Essen. The comparison between calculated and experimental depth dose curves showed significant deviations in the case of large radiation fields and of depth less than 5 cm. In the case of radiation field areas less than 150 cm2 and depth more than 5 cm (usual clinical situation), the measured and calculated values are in a good agreement. In the case of clinical situation, the dependence on the radiation field size is relatively well taken into account by the model presented here.

The value of urine testing for verifying adherence to anti-tuberculosis chemotherapy in children and adults in Uganda.

SETTING: Mulago Hospital, Kampala, Uganda. OBJECTIVE: To evaluate the usefulness of urine dipsticks for monitoring adherence to anti-tuberculosis chemotherapy. DESIGN: In-house urine dipsticks for detection of isoniazid (INH) metabolites were compared to commercial test strips. The value of n-butanol to detect rifampicin was compared to coloration of the urine. Non-adherence was assessed through a questionnaire and reviews of the Mulago Hospital TB register. RESULTS: Urine was obtained from 236 patients (127 adults and 109 children) on daily chemotherapy. Using commercial test strips as standard, the sensitivity of in-house urine dipsticks was 99.5% and specificity was 96.4%. The sensitivity and the specificity of n-butanol and of coloration of urine to detect rifampicin were low (64.0% and 54.9%, and 85.5% and 64.8%, respectively). Fifty patients (21.2%) admitted non-adherence to treatment during the previous month. An additional 15 (6.8%) were detected through urine testing. Of 911 patients in the TB register of Mulago Hospital who had started treatment in the first 3 months of 2000, 39.7% did not complete their treatment. Two-thirds of these had discontinued treatment in the first 2 months. CONCLUSION: In-house INH test strips are as effective as commercially available strips for detecting isoniazid in the urine. They are a simple tool for monitoring adherence. Adherence to anti-tuberculosis chemotherapy as determined by the use of isoniazid test strips and review of the TB register showed poor compliance. Tests for rifampicin are less sensitive and specific.

Balancing GFP reporter plasmid quantity in large-scale transient transfections for recombinant anti-human Rhesus-D IgG1 synthesis.

Using transient expression, high amounts (>20 mg/mL) of secreted anti-human Rhesus-D IgG1 were produced in a suspension-adapted HEK293 EBNA cell line (Meissner et al., Biotechnol Bioeng 75: 197-203, 2001). Time of harvest was 3 days after transfection. For the estimation of transfection efficiencies, we routinely co-transfected EGFP reporter DNA. At higher reporter plasmid concentrations, >2% of total transfecting plasmid DNA, a substantial reduction of recombinant antibody synthesis, was observed. This phenomenon was investigated in detail by co-expressing various green fluorescent protein (GFP) reporter constructs, which were targeted at different subcellular locations. Enhanced and humanized GFPs targeted to either the endoplasmic reticulum, the cytosol, or the nucleus reduced recombinant antibody production by 30 to 40% when present at higher concentrations in the transfection solution. The most severe effects were observed when the co-transfected EGFP was targeted to the endoplasmic reticulum, leading to a reduction of up to 80% in the presence of only 5% of reporter DNA. Interestingly, one nuclear-targeted GFP variant that was not codon optimized for expression in human cell lines could be added, to up to almost half of the total amount of transfecting DNA, without adverse effect on antibody production. Although the minimum amount of this reporter DNA needed for fluorescence reading was 10 times higher than for the other variants, it provided a much broader quantity range within which the transfection process could be studied without being negatively affected.

Empirical description and Monte Carlo simulation of fast neutron pencil beams as basis of a treatment planning system.

The fast neutron beam, used for fast neutron therapy in Essen, is produced by the nuclear reaction of a 14 MeV cyclotron-based deuteron beam on a thick beryllium target. The resulting neutron beam has a continuous energy spectrum with a mean and a maximum energy equal to 5.5 and 18 MeV, respectively. The dose delivered to the patient is computed by a treatment planning system (TPS) based on an empirical model, in which the dose components (neutron and photon) are described by analytical functions. In order to improve the dose calculation, and thus to use the fast neutron beam for other applications (e.g., Boron Neutron Capture Enhancement of Fast Neutron Therapy), in this work we aim to develop a new TPS. For this purpose, a model based on pencil beams of mono-energetic neutrons has been created. The neutron energy ranged from 0.25 MeV up to 17.25 MeV by steps of 0.5 MeV in order to cover the energy range of the Essen facility. The Monte Carlo method was then used to simulate the transport of neutrons within such pencil beams in a homogeneous water phantom. By using Monte Carlo techniques, it is possible to distinguish the energy deposition due to a primary collision in water to that due to scattered neutrons. The energy deposition due to pencil beams of 2.224 MeV photons, coming from hydrogen neutron capture reaction in the phantom or in the collimator, was also determined. In order to complete this work, air filled cylinders have been introduced in the water phantom. It is shown that the resulting depth dose curves for primary neutrons can be easily derived using the homogeneous phantom, and that the description of the effect on scattered neutron dose distribution is more complex. In this work we demonstrate the relevance of Monte Carlo simulations of mono-energetic neutron pencil beams for purposes of neutron treatment planning. Some additional work is still required to describe a clinical situation (continuous energy neutron spectrum) as well as to experimentally validate the method described here.

Porphyria cutanea tarda: the etiological importance of mutations in the HFE gene and viral infection is population-dependent.

A number of factors, including increased iron stores and alcohol consumption, are known to be associated with the development of porphyria cutanea tarda (PCT) in susceptible individuals. Recent reports have described a significant association between inheritance of the C282Y and H63D mutations in the HFE gene, associated with genetic hemochromatosis (GH) and PCT. A strong association between hepatitis C virus infection and PCT has also been demonstrated, while case reports record a link between human immunodeficiency virus (HIV) and PCT. We have investigated the frequency of these factors in a racially-mixed population of patients with PCT in Cape Town, South Africa. 57 patients with PCT drawn from three ethnic groups were screened for the presence of the C282Y and H63D mutations linked to GH, and the prevalences were compared with corresponding healthy control populations. The seroprevalence of markers for HCV, hepatitis B (HBV) and HIV infection were examined in 28 of these. In the control populations, we found that both the C282Y and H63D mutations are highly prevalent in South Africans of European origin. In a population of mixed or Asian origin, the C282Y mutation is very rare whereas the H63D mutation is common. Neither mutation was encountered in any African subject. Both mutations are associated with PCT, but the association is dependent on the ethnic origins of the population to which the patient belongs. In contrast to other studies, HCV infection is numerically unimportant in PCT in our patients. HIV infection is increasingly encountered in our patients with PCT, but the strength of the association cannot be determined in view of the high background prevalence of HIV infection in some sectors of the South African population. The contribution of specific risk factors may be heavily dependent on the population from which patients are drawn, and care should be taken in extrapolating from observations in one racial or geographic population to any other.

Transient gene expression: recombinant protein production with suspension-adapted HEK293-EBNA cells.

Transient gene expression (TGE) in mammalian cells at the reactor scale is becoming increasingly important for the rapid production of recombinant proteins. We improved a process for transient calcium phosphate-based transfection of HEK293-EBNA cells in a 1-3 L bioreactor volume. Cells were adapted to suspension culture using a commercially available medium (BioWhittaker, Walkersville, MD). Process parameters were optimized using a plasmid reporter vector encoding the enhanced green fluorescent protein (EGFP/CLONTECH, Palo Alto, CA, USA). Using GFP as a marker-protein, we observed by microscopic examination transfection efficiencies between 70-100%. Three different recombinant proteins were synthesized within a timeframe of 7 days from time of transfection to harvest. The first, a human recombinant IgG(1)-type antibody, was secreted into the supernatant of the cell culture and achieved a final concentration of >20 mg/L. An E. coli-derived DNA-binding protein remained intracellular, as expected, but accumulated to such a concentration that the lysate of cells, taken up into the entire culture volume, gave a concentration of 18 mg/L. The third protein, a transmembrane receptor, was expressed at 3-6 x 10(6) molecules/cell.