Heterologous cAd3-Ebola and MVA-EbolaZ vaccines are safe and immunogenic in US and Uganda phase 1/1b trials

Ebola virus disease (EVD) is a filoviral infection caused by virus species of the Ebolavirus genus including Zaire ebolavirus (EBOV) and Sudan ebolavirus (SUDV). We investigated the safety and immunogenicity of a heterologous prime-boost regimen involving a chimpanzee adenovirus 3 vectored Ebola vaccine [either monovalent (cAd3-EBOZ) or bivalent (cAd3-EBO)] prime followed by a recombinant modified vaccinia virus Ankara EBOV vaccine (MVA-EbolaZ) boost in two phase 1/1b randomized open-label clinical trials in healthy adults in the United States (US) and Uganda (UG). Trial US (NCT02408913) enrolled 140 participants, including 26 EVD vaccine-naïve and 114 cAd3-Ebola-experienced participants (April-November 2015). Trial UG (NCT02354404) enrolled 90 participants, including 60 EVD vaccine-naïve and 30 DNA Ebola vaccine-experienced participants (February-April 2015). All tested vaccines and regimens were safe and well tolerated with no serious adverse events reported related to study products. Solicited local and systemic reactogenicity was mostly mild to moderate in severity. The heterologous prime-boost regimen was immunogenic, including induction of durable antibody responses which peaked as early as two weeks and persisted up to one year after each vaccination. Different prime-boost intervals impacted the magnitude of humoral and cellular immune responses. The results from these studies demonstrate promising implications for use of these vaccines in both prophylactic and outbreak settings.

Safety, tolerability, and immunogenicity of the Ebola Sudan chimpanzee adenovirus vector vaccine (cAd3-EBO S) in healthy Ugandan adults: a phase 1, open-label, dose-escalation clinical trial

BACKGROUND

Sudan Ebola virus can cause severe viral disease, with an average case fatality rate of 54%. A recent outbreak of Sudan Ebola virus in Uganda caused 55 deaths among 164 confirmed cases in the second half of 2022. Although vaccines and therapeutics specific for Zaire Ebola virus have been approved for use during outbreak situations, Sudan Ebola virus is an antigenically distinct virus with no approved vaccines available.

METHODS

In this phase 1, open-label, dose-escalation trial we evaluated the safety, tolerability, and immunogenicity of a monovalent chimpanzee adenovirus 3 vaccine against Sudan Ebola virus (cAd3-EBO S) at Makerere University Walter Reed Project in Kampala, Uganda. Study participants were recruited from the Kampala metropolitan area using International Review Board-approved written and electronic media explaining the trial intervention. Healthy adults without previous receipt of Ebola, Marburg, or cAd3 vectored-vaccines were enrolled to receive cAd3-EBO S at either 1 × 1010 or 1 × 1011 particle units (PU) in a single intramuscular vaccination and were followed up for 48 weeks. Primary safety and tolerability endpoints were assessed in all vaccine recipients by reactogenicity for the first 7 days, adverse events for the first 28 days, and serious adverse events throughout the study. Secondary immunogenicity endpoints included evaluation of binding antibody and T-cell responses against the Sudan Ebola virus glycoprotein, and neutralising antibody responses against the cAd3 vector at 4 weeks after vaccination. This study is registered with ClinicalTrials.gov, NCT04041570, and is completed.

FINDINGS

40 healthy adults were enrolled between July 22 and Oct 1, 2019, with 20 receiving 1 × 1010 PU and 20 receiving 1 × 1011 PU of cAd3-EBO S. 38 (95%) participants completed all follow-up visits. The cAd3-EBO S vaccine was well tolerated with no severe adverse events. The most common reactogenicity symptoms were pain or tenderness at the injection site (34 [85%] of 40), fatigue (29 [73%] of 40), and headache (26 [65%] of 40), and were mild to moderate in severity. Positive responses for glycoprotein-specific binding antibodies were induced by 2 weeks in 31 (78%) participants, increased to 34 (85%) participants by 4 weeks, and persisted to 48 weeks in 31 (82%) participants. Most participants developed glycoprotein-specific T-cell responses (20 [59%, 95% CI 41-75] of 34; six participants were removed from the T cell analysis after failing quality control parameters) by 4 weeks after vaccination, and neutralising titres against the cAd3 vector were also increased from baseline (90% inhibitory concentration of 47, 95% CI 30-73) to 4 weeks after vaccination (196, 125-308).

INTERPRETATION

The cAd3-EBO S vaccine was safe at both doses, rapidly inducing immune responses in most participants after a single injection. The rapid onset and durability of the vaccine-induced antibodies make this vaccine a strong candidate for emergency deployment in Sudan Ebola virus outbreaks.

FUNDING

National Institutes of Health via interagency agreement with Walter Reed Army Institute of Research.

Low-dose intravenous and subcutaneous CIS43LS monoclonal antibody for protection against malaria (VRC 612 Part C): a phase 1, adaptive trial

BACKGROUND

Human monoclonal antibodies might offer an important new approach to reduce malaria morbidity and mortality. In the first two parts of a three-part clinical trial, the antimalarial monoclonal antibody CIS43LS conferred high protection against parasitaemia at doses of 20 mg/kg or 40 mg/kg administered intravenously followed by controlled human malaria infection. The ability of CIS43LS to confer protection at lower doses or by the subcutaneous route is unknown. We aimed to provide data on the safety and optimisation of dose and route for the human antimalaria monoclonal antibody CIS43LS.

METHODS

VRC 612 Part C was the third part of a three-part, first-in-human, phase 1, adaptive trial, conducted at the University of Maryland, Baltimore Center for Vaccine Development and Global Health, Baltimore, MD, USA. We enrolled adults aged 18-50 years with no previous malaria vaccinations or infections, in a sequential, dose-escalating manner. Eligible participants received the monoclonal antibody CIS43LS in a single, open-label dose of 1 mg/kg, 5 mg/kg, or 10 mg/kg intravenously, or 5 mg/kg or 10 mg/kg subcutaneously. Participants underwent controlled human malaria infection by the bites of five mosquitoes infected with Plasmodium falciparum 3D7 strain approximately 8 weeks after their monoclonal antibody inoculation. Six additional control participants who did not receive CIS43LS underwent controlled human malaria infection simultaneously. Participants were followed-up daily on days 7-18 and day 21, with qualitative PCR used for P falciparum detection. Participants who tested positive for P falciparum were treated with atovaquone-proguanil and those who remained negative were treated at day 21. Participants were followed-up until 24 weeks after dosing. The primary outcome was safety and tolerability of CIS43LS at each dose level, assessed in the as-treated population. Secondary outcomes included protective efficacy of CIS43LS after controlled human malaria infection. This trial is now complete and is registered with ClinicalTrials.gov, NCT04206332.

FINDINGS

Between Sept 1, 2021, and Oct 29, 2021, 47 people were assessed for eligibility and 31 were enrolled (one subsequently withdrew and was replaced) and assigned to receive doses of 1 mg/kg (n=7), 5 mg/kg (n=4), and 10 mg/kg (n=3) intravenously and 5 mg/kg (n=4) and 10 mg/kg (n=4) subcutaneously, or to the control group (n=8). CIS43LS administration was safe and well tolerated; no serious adverse events occurred. CIS43LS protected 18 (82%) of 22 participants who received a dose. No participants developed parasitaemia following dosing at 5 mg/kg intravenously or subcutaneously, or at 10 mg/kg intravenously or subcutaneously. All six control participants and four of seven participants dosed at 1 mg/kg intravenously developed parasitaemia after controlled human malaria infection.

INTERPRETATION

CIS43LS was safe and well tolerated, and conferred protection against P falciparum at low doses and by the subcutaneous route, providing evidence that this approach might be useful to prevent malaria across several clinical use cases.

FUNDING

National Institute of Allergy and Infectious Diseases, National Institutes of Health.

Safety, tolerability, and immunogenicity of the chimpanzee adenovirus type 3-vectored Marburg virus (cAd3-Marburg) vaccine in healthy adults in the USA: a first-in-human, phase 1, open-label, dose-escalation trial

BACKGROUND

WHO has identified Marburg virus as an emerging virus requiring urgent vaccine research and development, particularly due to its recent emergence in Ghana. We report results from a first-in-human clinical trial evaluating a replication-deficient recombinant chimpanzee adenovirus type 3 (cAd3)-vectored vaccine encoding a wild-type Marburg virus Angola glycoprotein (cAd3-Marburg) in healthy adults.

METHODS

We did a first-in-human, phase 1, open-label, dose-escalation trial of the cAd3-Marburg vaccine at the Walter Reed Army Institute of Research Clinical Trials Center in the USA. Healthy adults aged 18-50 years were assigned to receive a single intramuscular dose of cAd3-Marburg vaccine at either 1 × 1010 or 1 × 1011 particle units (pu). Primary safety endpoints included reactogenicity assessed for the first 7 days and all adverse events assessed for 28 days after vaccination. Secondary immunogenicity endpoints were assessment of binding antibody responses and T-cell responses against the Marburg virus glycoprotein insert, and assessment of neutralising antibody responses against the cAd3 vector 4 weeks after vaccination. This study is registered with ClinicalTrials.gov, NCT03475056.

FINDINGS

Between Oct 9, 2018, and Jan 31, 2019, 40 healthy adults were enrolled and assigned to receive a single intramuscular dose of cAd3-Marburg vaccine at either 1 × 1010 pu (n=20) or 1 × 1011 pu (n=20). The cAd3-Marburg vaccine was safe, well tolerated, and immunogenic. All enrolled participants received cAd3-Marburg vaccine, with 37 (93%) participants completing follow-up visits; two (5%) participants moved from the area and one (3%) was lost to follow-up. No serious adverse events related to vaccination occurred. Mild to moderate reactogenicity was observed after vaccination, with symptoms of injection site pain and tenderness (27 [68%] of 40 participants), malaise (18 [45%] of 40 participants), headache (17 [43%] of 40 participants), and myalgia (14 [35%] of 40 participants) most commonly reported. Glycoprotein-specific antibodies were induced in 38 (95%) of 40 participants 4 weeks after vaccination, with geometric mean titres of 421 [95% CI 209-846] in the 1 × 1010 pu group and 545 [276-1078] in the 1 × 1011 pu group, and remained significantly elevated at 48 weeks compared with baseline titres (39 [95% CI 13-119] in the 1 ×1010 pu group and 27 [95-156] in the 1 ×1011 pu group; both p<0·0001). T-cell responses to the glycoprotein insert and neutralising responses against the cAd3 vector were also increased at 4 weeks after vaccination.

INTERPRETATION

This first-in-human trial of this cAd3-Marburg vaccine showed the agent is safe and immunogenic, with a safety profile similar to previously tested cAd3-vectored filovirus vaccines. 95% of participants produced a glycoprotein-specific antibody response at 4 weeks after a single vaccination, which remained in 70% of participants at 48 weeks. These findings represent a crucial step in the development of a vaccine for emergency deployment against a re-emerging pathogen that has recently expanded its reach to new regions.

FUNDING

National Institutes of Health.

Low-Dose Subcutaneous or Intravenous Monoclonal Antibody to Prevent Malaria

BACKGROUND

New approaches for the prevention and elimination of malaria, a leading cause of illness and death among infants and young children globally, are needed.

METHODS

We conducted a phase 1 clinical trial to assess the safety and pharmacokinetics of L9LS, a next-generation antimalarial monoclonal antibody, and its protective efficacy against controlled human malaria infection in healthy adults who had never had malaria or received a vaccine for malaria. The participants received L9LS either intravenously or subcutaneously at a dose of 1 mg, 5 mg, or 20 mg per kilogram of body weight. Within 2 to 6 weeks after the administration of L9LS, both the participants who received L9LS and the control participants underwent controlled human malaria infection in which they were exposed to mosquitoes carrying Plasmodium falciparum (3D7 strain).

RESULTS

No safety concerns were identified. L9LS had an estimated half-life of 56 days, and it had dose linearity, with the highest mean (±SD) maximum serum concentration (C_max) of 914.2±146.5 μg per milliliter observed in participants who had received 20 mg per kilogram intravenously and the lowest mean C_max of 41.5±4.7 μg per milliliter observed in those who had received 1 mg per kilogram intravenously; the mean C_max was 164.8±31.1 in the participants who had received 5 mg per kilogram intravenously and 68.9±22.3 in those who had received 5 mg per kilogram subcutaneously. A total of 17 L9LS recipients and 6 control participants underwent controlled human malaria infection. Of the 17 participants who received a single dose of L9LS, 15 (88%) were protected after controlled human malaria infection. Parasitemia did not develop in any of the participants who received 5 or 20 mg per kilogram of intravenous L9LS. Parasitemia developed in 1 of 5 participants who received 1 mg per kilogram intravenously, 1 of 5 participants who received 5 mg per kilogram subcutaneously, and all 6 control participants through 21 days after the controlled human malaria infection. Protection conferred by L9LS was seen at serum concentrations as low as 9.2 μg per milliliter.

CONCLUSIONS

In this small trial, L9LS administered intravenously or subcutaneously protected recipients against malaria after controlled infection, without evident safety concerns. (Funded by the National Institute of Allergy and Infectious Diseases; VRC 614 ClinicalTrials.gov number, NCT05019729.).

Safety and immunogenicity of a trivalent virus-like particle vaccine against western, eastern, and Venezuelan equine encephalitis viruses: a phase 1, open-label, dose-escalation, randomised clinical trial

BACKGROUND

Western (WEEV), eastern (EEEV), and Venezuelan (VEEV) equine encephalitis viruses are mosquito-borne pathogens classified as potential biological warfare agents for which there are currently no approved human vaccines or therapies. We aimed to evaluate the safety, tolerability, and immunogenicity of an investigational trivalent virus-like particle (VLP) vaccine, western, eastern, and Venezuelan equine encephalitis (WEVEE) VLP, composed of WEEV, EEEV, and VEEV VLPs.

METHODS

The WEVEE VLP vaccine was evaluated in a phase 1, randomised, open-label, dose-escalation trial at the Hope Clinic of the Emory Vaccine Center at Emory University, Atlanta, GA, USA. Eligible participants were healthy adults aged 18-50 years with no previous vaccination history with an investigational alphavirus vaccine. Participants were assigned to a dose group of 6 μg, 30 μg, or 60 μg vaccine product and were randomly assigned (1:1) to receive the WEVEE VLP vaccine with or without aluminium hydroxide suspension (alum) adjuvant by intramuscular injection at study day 0 and at week 8. The primary outcomes were the safety and tolerability of the vaccine (assessed in all participants who received at least one administration of study product) and the secondary outcome was immune response measured as neutralising titres by plaque reduction neutralisation test (PRNT) 4 weeks after the second vaccination. This trial is registered at ClinicalTrials.gov, NCT03879603.

FINDINGS

Between April 2, 2019, and June 13, 2019, 30 trial participants were enrolled (mean age 32 years, range 21-48; 16 [53%] female participants and 14 [47%] male participants). Six groups of five participants each received 6 μg, 30 μg, or 60 μg vaccine doses with or without adjuvant, and all 30 participants completed study follow-up. Vaccinations were safe and well tolerated. The most frequently reported symptoms were mild injection-site pain and tenderness (22 [73%] of 30) and malaise (15 [50%] of 30). Dose-dependent differences in the frequency of pain and tenderness were found between the 6 μg, 30 μg, and 60 μg groups (p=0·0217). No significant differences were observed between dosing groups for any other reactogenicity symptom. Two adverse events (mild elevated blood pressure and moderate asymptomatic neutropenia) were assessed as possibly related to the study product in one trial participant (60 μg dose with alum); both resolved without clinical sequelae. 4 weeks after second vaccine administration, neutralising antibodies were induced in all study groups with the highest response seen against all three vaccine antigens in the 30 μg plus alum group (PRNT₈₀ geometric mean titre for EEEV 60·8, 95% CI 29·9-124·0; for VEEV 111·5, 49·8-249·8; and for WEEV 187·9, 90·0-392·2). Finally, 4 weeks after second vaccine administration, for all doses, the majority of trial participants developed an immune response to all three vaccine components (24 [83%] of 29 for EEEV; 26 [90%] of 29 for VEEV; 27 [93%] of 29 for WEEV; and 22 [76%] of 29 for EEEV, VEEV, and WEEV combined).

INTERPRETATION

The favourable safety profile and neutralising antibody responses, along with pressing public health need, support further evaluation of the WEVEE VLP vaccine in advanced-phase clinical trials.

FUNDING

The Vaccine Research Center of the National Institute of Allergy and Infectious Diseases, National Institutes of Health funded the clinical trial. The US Department of Defense contributed funding for manufacturing of the study product.

Safety and immunogenicity of an HIV-1 prefusion-stabilized envelope trimer (Trimer 4571) vaccine in healthy adults: A first-in-human open-label, randomized, dose-escalation, phase 1 clinical trial

BACKGROUND

Advances in therapeutic drugs have increased life-expectancies for HIV-infected individuals, but the need for an effective vaccine remains. We assessed safety and immunogenicity of HIV-1 vaccine, Trimer 4571 (BG505 DS-SOSIP.664) adjuvanted with aluminum hydroxide (alum), in HIV-negative adults.

METHODS

We conducted a phase I, randomized, open-label, dose-escalation trial at the National Institutes of Health Clinical Center in Bethesda, MD, USA. Eligible participants were HIV-negative, healthy adults between 18-50 years. Participants were randomized 1:1 to receive Trimer 4571 adjuvanted with 500 mcg alum by either the subcutaneous (SC) or intramuscular (IM) route at weeks 0, 8, and 20 in escalating doses of 100 mcg or 500 mcg. The primary objectives were to evaluate the safety and tolerability of Trimer 4571 with a secondary objective of evaluating vaccine-induced antibody responses. The primary and safety endpoints were evaluated in all participants who received at least one dose of Trimer 4571. Trial results were summarized using descriptive statistics. This trial is registered at ClinicalTrials.gov, NCT03783130.

FINDINGS

Between March 7 and September 11, 2019, 16 HIV-negative participants were enrolled, including six (38%) males and ten (62%) females. All participants received three doses of Trimer 4571. Solicited reactogenicity was mild to moderate in severity, with one isolated instance of severe injection site redness (6%) following a third 500 mcg SC administration. The most commonly reported solicited symptoms included mild injection site tenderness in 14 (88%) and mild myalgia in six (38%) participants. The most frequent unsolicited adverse event attributed to vaccination was mild injection site pruritus in six (38%) participants. Vaccine-induced seropositivity occurred in seven (44%) participants and resolved in all but one (6%). No serious adverse events occurred. Trimer 4571-specific binding antibodies were detected in all groups two weeks after regimen completion, primarily focused on the glycan-free trimer base. Neutralizing antibody activity was limited to the 500 mcg dose groups.

INTERPRETATION

Trimer 4571 was safe, well tolerated, and immunogenic in this first-in-human trial. While this phase 1 trial is limited in size, our results inform and support further evaluation of prefusion-stabilized HIV-1 envelope trimers as a component of vaccine design strategies to generate broadly neutralizing antibodies against HIV-1.

FUNDING

Intramural Research Program of the Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health.

[Ultraviolet-A1 (UVA1) phototherapy in lichen sclerosus et atrophicus]

Two patients, a nine year old girl and a 59 year old woman, presented with extensive and recalcitrant lichen sclerosus et atrophicus (LSA). Both patients were treated with low-dose ultraviolet-A1 (UVA1) phototherapy (340-400 nm) for ten weeks. The cumulative UVA1 dose was 800 J/cm(2), the single UVA1 dose was 20 J/cm(2). After 40 treatment sessions, the previously sclerotic skin lesions had almost completely cleared in both patients. In addition 20-MHz ultrasound examination and histological specimen revealed no further signs of sclerosis. UVA1 phototherapy seems to be a new and effective treatment for LSA with optimal patients' acceptance due to the absence of systemic side effects. UVA1 should be therefore considered as therapeutic option for LSA.

[Tazarotene increases the antipsoriatic effect of dithranol in chronic psoriasis]

We examined whether it is possible to increase the antipsoriatic action by combining dithranol with a retinoid (tazarotene). In a randomized, open, prospective study with 50 psoriatic patients (22 females, 28 males, PASI>10) the antipsoriatic effectiveness of dithranol monotherapy to was compared combined therapy with dithranol and retinoid. The combination dithranol/retinoid (collective 2, reduction of the PASI from 17,2 to 2,8) revealed a significantly faster healing than the dithranol monotherapy (collective 1, reduction of the PASI from 18,5 to 4,8). The irritation of the combination therapy as evaluated with clinical score and laser doppler imaging was increased. Anti-psoriatic effectiveness of dithranol can be increased by combining it with tazarotene.

[Ranking of 20 MHz sonography of malignant melanoma and pigmented lesions in routine diagnosis]

PURPOSE

Eleven dermatology clinics from all over Germany took part in our multicenter prospective study with the aim of evaluating 20 MHz sonography in the preoperative diagnosis of malignant melanomas and other pigmented skin tumours. It was to be assessed how effective sonographic measurement of thickness would compare to histology and the clinical palpation of tumour thickness and also the significance of differential diagnosis in sonography of malignant melanomas.

METHOD

The prospective multicenter study proceed as follows. To the end of August 1997 264 patients with a primary malignant melanoma and 417 patients with benign skin tumours were examined via 20 MHz sonography. Two different examiners estimated the clinical thickness of the tumour by palpation. The tumour was then excised and examined for postoperative correlation with the histology sections.

RESULTS

The final results showed good correlation between the histological and sonographic estimation of tumour thickness (r = 0.97). Estimation of tumour thickness by palpation showed no correlation with the histology (r = 0.59). Most of the benign (44%) and malignant tumours (38.7%) were spindle shaped. There was no significant difference between the benign and malignant tumour groups in relation to the sonographic presented shapes or echo signs. No different diagnosis could be made.

CONCLUSION

The technique of high frequency sonography in relation to preoperative diagnosis of malignant melanomas has high priority. In contrast to clinical estimation of tumour thickness, sonography provided a good correlation to histology. The effectiveness of sonography with regard to the valence of the skin tumours is limited and there is no possibility of differentiating between malignant and benign tumours from the morphological face value. Hence, there is a demand for developing a 150 MHz apparatus which will be able to supply evidence regarding the valence of skin tumours.

[High resolution 20 MHz ultrasound diagnosis in dermatology for noninvasive imaging of malignant melanomas]

For years, high-resolution b-scan ultrasound is a well established technique in dermatology regarding the preoperative determination of thickness of skin tumors like malignant melanoma or basal cell carcinoma. Most tumors appear as echopoor areas in high-frequency sonography. Until today, a differentiation between skin tumors by means of high-frequency ultrasound is not possible. This is also true concerning the differentiation between the tumor tissue itself and its subtumoral inflammatory infiltration. Therefore, this lack of differentiation leads to the fact that sonometric thicknesses of tumors often exceed the originally measured tumor thickness in histology. By means of three-dimensional reconstruction of serial b-scan images, it is possible to determine each tumor's volume and surface as well as the topographical arrangement of echopoor areas and sonographical structures. Besides high-frequency ultrasound, additional non-invasive techniques like MRI, ultrasound- or laser-doppler, computer-aided image analysis and epiluminescence microscopy are also available for diagnosing malignant melanoma. Epiluminescence microscopy is used today as a standard technique in the diagnosis of malignant melanoma due to the possibility of differential diagnosis. Latest techniques like OCT (optical coherence tomography) are not ready yet to be applied regularly in diagnosis of tumors in the field of dermatology.

The hyperperfusion of the psoriatic plaque correlates histologically with dilatation of vessels

We examined psoriatic lesions on the upper legs in 20 patients, using a two-dimensional Laser-Doppler-Scanner (Laser Doppler Perfusion Imager LDI, Lisca Development, Linköping/Sweden). The plaques were evaluated weekly during therapy with dithranol. Five plaques were reconstructed three-dimensionally before and after therapy (reconstruction program ANAT 3D, SIS, Münster, Germany). The psoriatic plaque was represented in the Laser Doppler Perfusion image as a sharply demarcated, hyperperfused area. The perfusion of the plaques dropped during therapy with dithranol to just slightly increased values, compared with normal skin (2.04 arbitrary units AU, healthy skin 1.1 AU). Using three-dimensional reconstruction, we investigated the volume of dermal vessels and the density of papillae. When compared, the volume of papillary vessels was twice as large in psoriatic as in healthy skin. The number of the papillae per square millimetre, detected by three-dimensional reconstruction, was not reduced significantly during therapy. We think that the increased perfusion of the psoriatic plaque is due to the combination of morphological (dilatation of vessels), dynamic (increased blood flow) and optical effects (reduced scattering and increased sampling depth of the laser-beam in acanthotic tissue).

[Traumatic subdural hygromas (author's transl)]

Out of a group of 97 patients with intracranial haematomas, 12 were found to have a traumatic subdural hygroma. In four patients a small fluid effusion was demonstrated by CT scan just after the head injury. In the majority of cases the CT scan demonstrated a significant increase of volume and pressure of the subdural effusion during the second to third week. Half the patients simultaneously developed a moderate ventricular dilatation. The development of a subdural effusion was hard to recognize from the clinical course. Nevertheless the patients mostly had a good post-operative recovery. The hygromas disappeared by subdural peritoneal shunting. In two patients a ventriculoatrial shunt was necessary on account of the hydrocephalus. Based upon clinical and CT scan characteristics a multifactorial hypothetical model of the development of the traumatic subdural effusion is proposed.

Direction of proton translocation in proteoliposomes formed from purple membrane and acidic lipids depends on the pH during reconstitution

The reconstitution of proton pumping activity in proteoliposomes formed by brief sonication of purple membrane and lipid dispersions was studied as a function of pH. Proteoliposomes reconstituted using cardiolipin showed light-dependent proton extrusion when formed at a pH below 2.75 and proton uptake when formed above pH 2.75. Several other acidic lipids including halobacterial lipids behaved similarly. The experiments suggest that the degree of dissociation of the lipid phosphate groups determines the preferential orientation of bacteriorhodopsin in reconstituted proteoliposomes.

Phage Qbeta replicase: cell-free synthesis of the phage-specific subunit and its assembly with host subunits to form active enzyme

Cell-free translation of Qbeta RNA and subsequent partial purification of the enzyme resulted in replicase activity. From 0.5 to 1.5% of all R chains synthesised were found in the 7-S replicase complex. The presence in the 7-S complex of the host subunits of authentic replicase, i (= S1) and EF-Ts, was shown by the effect of antisera directed against ribosomal protein S1 and EF-Ts, respectively. Furthermore, the presence of EF-Ts was demonstrated by thermal denaturation of in vitro replicase made by a cell extract from an Escherichia coli mutant with a thermolabile EF-Ts. In vitro replicase did not assemble spontaneously during protein synthesis but was formed upon subsequent purification. Assembly could be induced by ammonium sulphate precipitation (60% saturation) alone. It is concluded that the functional phage-coded subunit synthesised in vitro recognises i and the EF-Tu - EF-Ts complex among a mixture of host proteins.