Kinetics of desynchronization and distribution of generation times in synchronized cell populations

The kinetics of the distribution of generation times in synchronized cells can be analyzed by using Fourier transform analysis. Deviations of the experimental data from the curve of completely asynchronous growth reflect the degree of synchrony at a particular time. Fourier transform analysis of these deviations yields the average generation time as well as information on the distribution of generation times characterizing a synchronized culture. A detailed analysis of synchronized cell cultures does not provide any evidence for the existence of a subcycle or a polymodal distribution in generation times. The data do indicate that cell-cell interaction occurs at cell densities as low as 2.5 X 10(3)/cm2. It is also shown that the Eyring-Stover formalism for the dynamics of survival can correctly describe the distribution of the first round of cell divisions in a synchronized culture.

Removal of viral contaminants by monoclonal antibody purification of plasma proteins

The transmittance of pathogenic viruses by the widespread administration of protein fractions such as F VIII prepared on a large scale from pooled human plasma has been of growing concern. We have now demonstrated that significant amounts of pathogenic viruses including LAV/HTLVIII may be removed by a new large scale fractionation process for the preparation of human F VIII (Monoclate) which employs immunoaffinity chromatography. Model viruses representative of different virus families and the LAV strain of HIV were added to cryoprecipitate and then the mixture was processed as for Monoclate manufacturing. Virus titers were determined at each step of the fractionation procedures. An overall reduction of at least 6 logs was obtained for the model viruses and the HIV due to the purification process. An added heating step further increased the safety margin for the product resulting in at least an overall reduction of 7-9 logs for HIV. Clinical experience with Monoclate in virgin hemophiliacs has confirmed its viral safety. Our laboratories are exploiting a similar strategy of immunoaffinity chromatography to ensure the viral safety of FIX and protein C preparations derived from plasma.

Fetoscopic laser ablation in twin-to-twin transfusion syndrome: tips for counselling

Twin-to-twin transfusion syndrome (TTTS) is a serious complication that affects approximately 10-15% of monochorionic twin pregnancies. The most important role for the development of this condition is the presence of an unbalanced flow through the inter-twin vascular anastomoses. Depending on the number, type and direction of the connecting vessels, blood can be transfused disproportionately from one twin (the donor) to the other twin (the recipient). The diagnosis is defined prenatally by ultrasound and involves of two main criteria: the presence of a monochorionic diamniotic (MCDA) pregnancy; and the presence of oligohydramnios in the donor's sac- deep vertical pocket (DVP) 2 cm - and polyhydramnios in the recipient's sac- DVP>8 cm. Once diagnosed, TTTS is usually graded by using the Quintero staging system, that is composed by five stages, from oligohydramnios in the donor and polyhydramnios in the recipient twin to fetal demise in one or both twins. Photocoagulation of the anastomotic vessels, usually followed by equatorial dichorionization, it has currently become the most common fetoscopic operation today and is considered as the gold standard for stage II-IV TTTS. pPROM, chorioamniotic separation and iatrogenic preterm birth are among the most common complications of fetoscopic laser ablation, and the mean gestational age at delivery after laser procedure is about 31 weeks.

Antibodies to the triplet codons AAA, AAC, and AUG: reactions with nucleic acids

Antibodies specific for the trinucleotide codons AAA, AUG, and AAC were examined for their reactions with nucleic acids. Anti-AUG and anti-AAC precipitated denatured DNA. Anti-AAA did not, and moreover, the binding of a tritiated AAA derivative to anti-AAA was not inhibited by denatured DNA. Radioligand-binding studies showed that anti-AAA was highly specific for the triplet sequence, some cross-reactions occurring with di-A and tetra-A but little with A and poly(A). The anti-codons did not precipitate whole yeast RNA, but binding could be demonstrated with Escherichia coli 3H-rRNA. Anti-AAC and anti-AUG (but not anti-AAA) bound E. coli 14C-tRNA. Anti-AUG was found to inhibit protein synthesis in an in vitro system in which rabbit reticulocyte mRNA was being translated. Inhibition was abolished by absorption of the antibody with AUG-RSA. The results of these and previous experiments (reference 1) are interpreted to indicate that antibodies can recognize trinucleotide sequences but not with absolute specificity, and it is suggested that antibodies to longer nucleotide sequences might show specificity comparable to that shown by antibodies to polysaccharide and peptide sequences.

Cavernous haemangioma and mid trimester pregnancy loss leading to severe haemorrhage and hysterectomy: a case report and review of literature

Background

Cavernous haemangiomas are benign vascular tumours that are known to occasionally involve the female genital tract, including the uterus. They are often underdiagnosed during pregnancy, although they can also lead to severe postpartum or antepartum haemorrhage.

Objectives

Describe our case of an uncommon second-trimester pregnancy loss in a woman with a diffuse cavernous haemangioma of the uterus and cervix and review the wider literature.

Methods

The review was conducted using MEDLINE, Scopus and PubMed electronic databases from beginning of the database to May 2023, using the following keywords: arteriovenous malformation; cavernous haemangioma/hemangioma; uterine neoplasms; pregnancy complications; abnormal vaginal bleeding.

Main outcome measures

Description of the characteristics of cavernous haemangioma during pregnancy as well as diagnostic criteria and treatment options.

Results

Twenty publications were included in the review, which included English-language case reports over a period from 1959 to 2022. No pathognomonic symptoms for cavernous haemangioma of the uterus in a pregnant woman were noted. Complications including massive secondary postpartum haemorrhage, haemoperitoneum, and severe thrombocytopenia with anaemia after delivery were reported.

Conclusions

Diagnosis and management during pregnancy can be challenging and requires considerable attention, with a multidisciplinary approach including gynaecologists, radiologists, and pathologists to avoid major complications.

What is new?

An additional case of diffuse cavernous haemangioma of the uterus and cervix is described, that adds to the little existing literature.