Suction blister skin grafting--a modern application.

The suction blistering technique produces an ultra-thin skin graft with no morbidity at the donor site. Negative pressure using wall suction in outpatients is used to generate a graft that can be used for reconstruction, and it avoids the need for invasive procedures in patients with coexisting conditions. The harvested tissue has a low metabolic demand and survival is excellent. We used it in a patient when previous reconstructions after excision of skin cancer had failed. Graft survival was more than 95% by surface area and there was no donor site morbidity. We have found it particularly useful for grafting over Integra® dermal regeneration template (Integra LifeSciences Corporation, NJ, USA) to produce healing at difficult sites. Patients tolerate the procedure well and the donor site heals quickly. It is useful where recipient vascularity is poor or where coexisting conditions prevent complex procedures.

Caspase 3 deficiency rescues peripheral nervous system defect in retinoblastoma nullizygous mice.

The retinoblastoma tumor suppressor protein, pRb, is a key regulator of cell cycle and has been implicated in the terminal differentiation of neuronal cells. Mice nullizygous for pRb die by embryonic day 14.5 from hematopoietic and neurological defects attributed to failed differentiation (Clarke et al., 1992; Jacks et al., 1992; Lee et al., 1992). Previous studies by MacLeod et al. (1996) have demonstrated that the loss of p53 protects Rb-deficient CNS neurons but not peripheral nervous system (PNS) neurons from cell death. Thus, the mechanisms by which PNS neurons undergo apoptosis in response to Rb deficiency remain unknown. In view of the pivotal role of caspase 3 in the regulation of neuronal apoptosis during development, we examined its function in the execution of the wide-spread neuronal cell death induced by Rb deficiency. Our results support a number of conclusions. First, we show that caspase 3 becomes activated in all neuronal populations undergoing apoptosis. Second, caspase 3 deficiency does not extend the life span of Rb null embryos, because double null mutants exhibit high rates of liver apoptosis resulting in erythropoietic failure. Third, Rb/caspase 3 double-mutant neurons of the CNS exhibit widespread apoptosis similar to that seen in Rb mutants alone; thus caspase 3 deficiency does not protect this population from apoptosis. Finally, in contrast to the CNS, neurons of the PNS including those comprising the trigeminal ganglia and the dorsal root ganglia are protected from apoptosis in Rb/caspase 3 double-mutant embryos. Examination of the mechanistic differences between these two cell types suggest that CNS neurons may invoke other caspases to facilitate apoptosis in the absence of caspase 3. These findings suggest that PNS neurons are dependent on caspase 3 for the execution of apoptosis and that caspase 3 may serve as a key therapeutic target for neuroprotection after injury of this cell type.

Cervical lymphadenitis in children: the role of Mycobacterium avium-intracellulare.

Non-tuberculous mycobacteria are the most frequent cause of mycobacterial cervical lymphadenitis in children. Although uncommon, the incidence in recent years has shown a marked increase. Its early differentiation from tuberculous mycobacterial lymphadenitis is essential as the treatment of choice is early surgical excision rather than antituberculous chemotherapy. Three such cases are reported with emphasis on the differential diagnosis and management.

Orbital emphysema and the medial orbital wall: a review of the literature with particular reference to that associated with indirect trauma and possible blindness.

Orbital emphysema is not an uncommon finding following fractures of the facial skeleton. Both its significance as a threat to sight and its diagnostic value may well be underestimated. Fractures of the paranasal sinuses may occur as a result of indirect trauma. This article reviews the literature on the subject with particular reference to blindness as a possible sequel. Two cases of orbital wall fracture that occurred as a result of indirect trauma and which produced orbital emphysema are discussed.

Primary epithelioid sarcoma of the hard palate. A case report.

A case of primary epithelioid sarcoma of the hard palate is described with no evidence of metastases. Review of the literature revealed no other reported cases of epithelioid sarcoma at this site. The patient, a 20-year-old male negro, returned with 2 local recurrences after initial excision but with no evidence of metastases. He remains well with no evidence of disease at present. This report records a unique primary site for this tumour, and illustrates the diagnostic difficulties, both clinical and histological, which this tumour may present.

The effect of dexamethasone on neurapraxia following third molar surgery.

A double blind, controlled trial was undertaken to assess the effect of intra-muscular dexamethasone on neurapraxia following the surgical removal of mandibular third molars. No significant difference was found 24 h post-operatively between a control group and a group given dexamethasone.

Lipoid proteinosis: Urbach-Wiethe disease.

An otherwise healthy patient with Urbach-Wiethe disease required surgical removal of two 3rd molar teeth. In this multisystem disorder infiltration of the buccal, pharyngeal and laryngeal mucosa may cause difficulties with tracheal intubation and increase the likelihood of trauma. The anaesthetic implications and management are described.

Liver tissue from lactating rats produces a factor that stimulates prolactin release and gene expression.

Liver tissue from nursing rats produces a substance, termed liver lactogenic factor (LLF), that potently stimulates casein release from isolated mammary cells. Inasmuch as the production of LLF is dependent on PRL, we decided to determine whether it could influence the release of the hormone by dissociated pituitary cells in culture. This was accomplished by measuring PRL release with a reverse hemolytic plaque assay and PRL gene expression with a DNA probe complementary to PRL mRNA. Treatment of pituitary cells from day 10 lactating rats with liver slice incubates from the same type of animal caused a 35.3 +/- 4.3% increase in PRL release during a 3-h incubation. Likewise, the same dose of LLF activity markedly increased (3.5-fold) the steady state levels of PRL mRNA. The responses were reasonably specific for PRL, since neither GH plaque development nor gene expression was affected by identical treatment. Taken together these results demonstrate that LLF can act directly at the pituitary level to exert positive feedback effects on both PRL release and gene expression.

Synovial chondromatosis of the temporomandibular joint.

Synovial chondromatosis of the temporomandibular joint is a rare, benign condition of metaplastic change of the synovium. A case is reported and the world literature is reviewed.

A Champy plate template.

The construction and use of a template is described as an aid for the surgeon using the Champy bone-plate system. It could easily be adapted for use with other plating systems.

Extracranial meningioma of the oral cavity.

A case of a maxillary tumour resembling an extracranial meningioma is reported. So far as can be ascertained no other instance of this same tumour has been recorded occurring in the oral cavity.

Sources of proteins in human bile.

The proteins of 46 human bile specimens, collected by several different routes have been studied by crossed immunoelectrophoresis, by rocket immunoelectrophoresis and by radioimmunoassay. The results were analysed by plotting the variation in the bile: plasma ratio of particular proteins against molecular weight and by examination of the correlation between the concentrations of different proteins in the biles of different patients. Our results show that the majority of human bile proteins derive from plasma although bile specific proteins are always present. The majority of plasma proteins appear to enter bile by a 'sieving' mechanism which results in an inverse relationship between the bile: plasma ratio and the molecular weight. In addition there was a very high degree of correlation between the biliary concentrations of alpha 2-macroglobulin, IgG, haptoglobin, haemopexin, albumin, prealbumin, and orosomucoid. A number of other proteins namely thyroxine binding globulin, GC globulin and alpha 2HS-glycoprotein appeared in bile at concentrations greater than those expected if entry is by the sieving mechanism. These three proteins, however, are of rather low molecular weight and the reason for the lack of correlation appears to be individual variation in the 'pore size', presumably reflecting variation in the porosity of tight junction between hepatocytes. Although the majority of human bile proteins would appear to enter bile by a molecular weight-dependent pathway, four proteins, namely secretory IgA, IgM, haemoglobin and caeruloplasmin, showed significant deviation from the predicted relationship and probably enter bile at least partly by transport across cells. The concentration of beta 2-glycoprotein I was also much greater than expected from its molecular weight. The reason for this is not yet clear but may well reflect a very efficient and specific transport mechanism.