[Value of exfoliative cytology of the urinary bladder in occult bladder cancer and in the control of treated cancers]

The exfoliative cytology of the urinary bladder is helpful in the detection of occult bladder carcinoma, which in according to definition is not recognizable without magnification, as well as in the follow-up of treated bladder carcinoma. Within a period of 5 years 23 occult bladder carcinomas were detected by cytological studies alone. The degree of malignancy of the established transitional cell carcinoma varied between G2 and G3. The latent period between the found cytological result and the histological confirmation amounted to 14 months. In our experience the diagnosis of occult bladder carcinoma can be established by exfoliative cytology of the urinary bladder, if invisible parts of tumor with moderate and high degree of malignancy communicate with the mucosa of the bladder. The cytological recognition of malignant cells of urothelium offers valuable support for further therapeutic procedures, if there is no cystoscopic evidence of tumor in the bladder. In addition to clinical diagnosis of bladder cancer exfoliative cytology of the urinary bladder should also be part of the follow-up of treated bladder cancer.

[The urgency of special x-ray control in the conservative treatment of femoral fractures in childhood]

The conservative treatment of fractures of the shaft of the femur by extension according to Weber has been successful with children. It is simple to position the young patient on the so called "Weberbock", the position of the fragments can be always controlled radiologically, and if necessary, it can be corrected. But recent investigations have shown, that in some cases false torsions are corrected spontaneously.

Cyclic AMP receptor proteins interacts with lactose operator DNA

The wildtype lac promoter-operator region of E. coli was reinvestigated for cyclic AMP receptor protein (CRP) binding sites using the 'footprinting' method. Two distinct interaction sites were found, one in the -60 base pair region, which has previously been described, and a second one covering the lac operator. These two sites are similar in extent, orientation and the characteristic pattern of CRP-induced DNaseI enhanced cutting sites.

Sequence-specific interactions of the tight-binding I12-X86 lac repressor with non-operator DNA

The tight-binding I12-X86 lac repressor binds to non-operator DNA in a sequence-specific fashion. Using the DNA of the E. coli I gene we have investigated these sequence-specific interactions and compared them to the operator binding of wild-type repressor. The specific, non-operator DNA interactions are sensitive to the inducer IPTG. One strong binding site in the I gene DNA was found to be one of two expected on the basis of their homology with the lac operator. The binding of I12-X86 repressor to this site was visualized using the footprinting technique, and found to be consistent with an operator-like binding configuration. The protection pattern extends into an adjacent sequence suggesting that two repressor tetramers are bound in tandem.

The interaction of RNA polymerase and lac repressor with the lac control region

We have examined the interactions of lac repressor and RNA polymerase with the DNA of the lac control region, using a method for direct visualization of the regions of DNA protected by proteins from DNAase attack. The repressor protects the operator essentially as reported by Gilbert and Maxam (1) with some small modifications. However, the evidence reported here concerning the binding of RNA polymerase to the DNA of the promoter mutant UV5 indicates that : 1) the RNA polymerase molecule binds asymmetrically to the promoter DNA, 2) RNA polymerase protects DNA sequences to within a few bases of the CAP binding site, suggesting direct interaction between polymerase and the CAP protein at this site, 3) RNA polymerase still binds to the promoter when repressor is bound to the operator, but fails to form the same extensive complex.

[Autologous blood transfusion in a department of gynaecological surgery]

A single unit of 350 ml of whole blood was drawn 8 days before surgery, from 50 patients of a gynecological clinic. Hysterectomy was performed in 44 cases. Haematological values did not show any significant modification and no side effects attributable to the phlebotomy was detected before or during surgery. In 88% of cases, the utilisation of autologous blood has avoided an homologous transfusion whose side effects are well known.

DNAse footprinting: a simple method for the detection of protein-DNA binding specificity

A method for studying the sequence-specific binding of proteins to DBA is described. The technique is a simple conjoining of the Maxam-Gilbert DNA-sequencing method and the technique of DNAase-protected fragment isolation. Fragments of a 5' end-labelled, double-stranded DNA segment, partially degraded by DNAase in the presence and absence of the binding protein, are visualized by electrophoresis and autoradiography alongside the base-specific reaction products of the Maxam-Gilbert sequencing method. It is then possible to see the protective "footprint" of the binding protein on the DNA sequence. The binding of lac repressor to lac operator is visualized by "footprinting" as an example. Equillibrium estimates indicate that 10-fold sequence-specificity (differential binding constant) could be studied easily using this technique.

Mutations affecting the quaternary structure of the lac repressor

A new class of point mutations in the lacI gene of Escherichia coli is described which results in a lac repressor that is unable to form its normal tetrameric structure. Many of these mutations result in amino acid substitutions in the neighborhood of the tyrosine at residue 269. An amber mutation derived from the codon normally specifying tyrosine 269 has been suppressed with Sul, which inserts serine in response to the amber codon. The resulting altered lac repressor is also unable to form its normal tetrameric structure and can no longer bind to the lac operator. Two missense mutations which map in the part of the gene specifying amino acid residues 210 to 216 also produce repressors unable to form tetramers.

Subacute thyroiditis. Eleven cases with histological confirmation and thyrotrophic response to thyrotrophin releasing hormone

Eleven cases are reported of subacute thyroiditis with histopathological study; there were 9 females and 2 males. Bacteriological studies were inconclusive. Different stages of pathological involvement were observed at the same time in all patients. The clinical course followed the classical pattern in most cases: hyperthyroid-like, hypothyroid-like phase and recovery. Blood TSH assessment before and after TRH stimulation revealed an early phase of depression unresponsive to TRH, followed by high levels with marked stimulation; during the first phase, radioiodine uptake was low, but was enhanced by exogenous TSH administration; accordingly the low uptake seems to be due to low TSH levels and not to complete destruction of the thyroid gland. Failure of TSH levels to rise after TRH stimulation is typical of this stage of the disease. Although the final outcome is not yet predictable in some patients, definitive myxoedema appears to be probable in two cases.