Spinal motoneurons respond aberrantly to serotonin in a rabbit model of cerebral palsy.

Cerebral palsy (CP) is caused by a variety of factors that damage the developing central nervous system. Impaired motor control, including muscle stiffness and spasticity, is the hallmark of spastic CP. Rabbits that experience hypoxic-ischemic (HI) injury in utero (at 70-80% gestation) are born with muscle stiffness, hyperreflexia, and, as recently discovered, increased serotonin (5-HT) in the spinal cord. To determine whether serotonergic modulation of spinal motoneurons (MNs) contributes to motor deficits, we performed ex vivo whole cell patch clamp in neonatal rabbit spinal cord slices at postnatal day (P) 0-5. HI MNs responded to application of α-methyl 5-HT (a 5-HT 1 /5-HT 2 receptor agonist) and citalopram (a selective 5-HT reuptake inhibitor) with hyperpolarization of persistent inward currents and threshold voltage for action potentials, reduced maximum firing rate, and an altered pattern of spike frequency adaptation while control MNs did not exhibit any of these responses. To further explore the differential sensitivity of MNs to 5-HT, we performed immunohistochemistry for inhibitory 5-HT 1A receptors in lumbar spinal MNs at P5. Fewer HI MNs expressed the 5-HT 1A receptor compared to age-matched controls. This suggests many HI MNs lack a normal mechanism of central fatigue mediated by 5-HT 1A receptors. Other 5-HT receptors (including 5-HT 2 ) are likely responsible for the robust increase in HI MN excitability. In summary, by directly exciting MNs, the increased concentration of spinal 5-HT in HI rabbits can cause MN hyperexcitability, muscle stiffness, and spasticity characteristic of CP. Therapeutic strategies that target serotonergic neuromodulation may be beneficial to individuals with CP. Key points: After prenatal hypoxia-ischemia (HI), neonatal rabbits that show hypertonia are known to have higher levels of spinal serotoninWe tested responsivity of spinal motoneurons (MNs) in neonatal control and HI rabbits to serotonin using whole cell patch clampMNs from HI rabbits showed a more robust excitatory response to serotonin than control MNs, including hyperpolarization of the persistent inward current and threshold for action potentials, larger post-inhibitory rebound, and less spike frequency adaptation Based on immunohistochemistry of lumbar MNs, fewer HI MNs express inhibitory 5HT 1A receptors than control MNs, which could account for the more robust excitatory response of HI MNs. These results suggest that after HI injury, the increased serotonin could trigger a cascade of events leading to muscle stiffness and altered motor unit development.

The impact of Scottish Government protocols on practice in Scotland.

Objectives: To investigate rates of septorhinoplasty and rhinoplasty in Scotland between 2006 and 2010, and to establish the impact of government legislation. Methods: Data on the rates of rhinoplasty and septorhinoplasty were collected and analysed according to specialty, region and year. Results: In 2006, 754 septorhinoplasty and rhinoplasty cases were recorded (147 per million population), rising to 893 (171 per million population) in 2010. Mean annual rates per million population were 152 (87 per cent of procedures) in ENT, 13.9 (8 per cent) in plastic surgery and 8.7 (8 per cent) in oromaxillofacial surgery. After 2009, there was a 43 per cent reduction in the rhinoplasty rate (p < 0.0001), although the oromaxillofacial surgery rate increased by 68 per cent (p < 0.05). Over the same period, the septorhinoplasty rate increased in ENT (46 per cent, p < 0.0001), and declined in plastic surgery (24 per cent, p = 0.49) and oromaxillofacial surgery (45 per cent, p = 0.05). Overall, the rate for rhinoplasty plus septorhinoplasty only declined by 1 per cent. There was significant regional variation. Conclusion: Overall, septorhinoplasty rates have increased and rhinoplasty rates have decreased. There was only a 1 per cent decrease in the overall rate following the 2009 legislation. Practice differs between regions.

Elasticated retractors in tracheostomy.

We present a novel way of providing and improving retraction whilst performing tracheostomies, using elasticated retractors. The benefits of this method include an improved surgical field and the facility for use by a single surgeon. This type of retraction could potentially be used in a variety of other head and neck procedures.

Current and future practices in surgical retraction.

Retraction of tissues and anatomical structures is an essential component of all forms of surgery. The means by which operative access is gained through retraction are many and diverse. In this article, the various forms of retraction methods currently available are reviewed, with special reference to hand held, self-retaining and compliant techniques. The special challenges posed by laparoscopic surgery are considered and future developments in new retraction techniques are anticipated.

Metastatic malignant melanoma of the larynx.

Metastatic malignant melanoma of the larynx is considered to be extremely rare by most authors. This paper describes a 78-year-old patient, previously treated for cutaneous malignant melanoma and intestinal fibrosarcoma, who presented with stridor due to a metastatic melanoma in the larynx. It was a pedunculated lesion and surgical excision of the lesion was accomplished with a tonsillar snare. This paper further discusses the evolving history, diagnosis and treatment of this metastatic tumour, and reviews the literature regarding previously reported cases.

Clinical evaluation of borderline nuclear changes in cervical smears at colposcopy and biopsy.

The aim of this study was to determine the incidence of cervical intraepithelial neoplasia at colposcopy and biopsy in woman with smears showing borderline nuclear changes to assess the predictive rate of colposcopy in identifying CIN and to verify the importance of follow-up. A retrospective study of 134 cases referred for colposcopic assessment with borderline nuclear changes in smears was carried out. Of the 134 patients studied, 44.8% had cervical intraepithelial neoplasia and 30% had benign changes of the cervix; 25.5% of cases were normal, 14% of the study population had HPV infection confirmed by biopsy. Of all cases of CIN, 38% were diagnosed to have low grade abnormalities, 6.8% had high-grade abnormalities. The predictive rate of colposcopy in identifying low-grade abnormalities was approximately 60% and 80.7% had a normal smear after 6 months, follow-up. As cervical intraepithelial neoplasia was found in a significant number of patients, borderline changes in cervical smears need subsequent evaluation. Even though more than two-thirds of women had negative smears at 6-month follow-up, the study recommends annual follow-up smears for several years as the long-term risk is not definitely known.

Nephroblastoma in a 76-year-old male.

Nephroblastoma is an infantile neoplasia with a low incidence in adults. A case of Wilms' tumour in a 76-year-old male is reported. In a literature review the current status of knowledge in the geriatric population is discussed.

Angioimmunoblastic lymphadenopathy, sulphasalazine exposure and villous atrophy.

A woman with inflammatory lesions in the terminal ileum was treated with sulphasalazine. Nine months later she developed angioimmunoblastic lymphadenopathy and was found to have intestinal villous atrophy. Her systemic illness partially responded to oral steroids but a gluten free diet restored clinical and biochemical well being coincident with a return of her villous pattern.

Some cytofluorimetric studies of the nuclear ploidy of mouse hepatocytes. I. A simple method for isolation of hepatocyte nuclei using in situ perfusion of the liver.

A simple method for isolating mouse hepatocyte nuclei is presented, which requires no special apparatus. Flow cytofluorimetric scans of hepatocyte nuclei, prepared by this method and stained with ethidium bromide, showed that adult mice have a high proportion of their hepatocyte nuclei in the tetraploid and octaploid states. Polyploidy was more pronounced in female animals.

Some flow cytofluorimetric studies of the nuclear ploidy of mouse hepatocytes. II. Early changes in nuclear ploidy of mouse hepatocytes following carbon tetrachloride administration: evidence for polyploid nuclei arrested in telophase.

Mature mice have a large proportion of their hepatocyte nuclei in polyploid states (tetraploid and octaploid), and this is more prominent in females. We measured nuclear ploidy distribution cytometrically using ethidium bromide-stained hepatocyte nuclei liberated by in situ collagenase perfusion of the liver via the portal vein. After s.c. administration of 0.2 ml carbon tetrachloride the ploidy distributions of 8-month-old female mice changed from a control of 35% 2N, 45% 4N, and 20% 8N to 54% 2N, 45% 4N and 1% 8N at 6 h, and 65% 2N, 35% 4N and 0% 8N at 24 h. By 72 h 92% of the nuclei were diploid. These changes preceded any changes in mitotic index and S-phase index (3H-TdR autoradiographs). Histology confirmed the loss of higher-ploid nuclei but without mitotic figures or selective cell necrosis to account for the observations. Cleaved nuclei were prominent in sections of liver examined 3 h after CCl4 administration and suggested division of polypoid nuclei that had undergone prior segregation of chromatids and had presumably been arrested in telophase.

DNA synthesis in the urinary tract epithelium of the rat induced by ureteric ligation.

The effect of ligating the left ureter on the thymidine-labeling index (LI) of epithelial cells lining the urinary tract in male Wistar rats has been investigated and compared with the LI in appropriate control groups. In experiment 1, the temporal pattern of the response was studied. In the left ureter, the LI above and below the ligature began to increase at about 8 hours and reached a peak approximately 100 times normal control values at 18 hours. At 48 hours, the LI above the ligature was still about 15 times normal, but distal to the ligature it was significantly below normal levels. There were also impressive increases in the LI in the epithelium of the left renal pelvis and in the tubular cells of the left renal cortex. An unexpected observation was a significant increase in the LI in the right ureter and bladder of these animals and similar increases in both ureters and bladders of sham-operated animals and laparotomy controls. Other unusual features were a significant decrease in the LI in the cortical tubular cells in all the sham-operated animals and in some ligated groups, and a highly significant sustained reduction in the LI of hepatocytes in both sham-operated and ligated animals but not in anesthetic controls. In experiment 2, the topographic relationship between the ligature and the changes in thymidine labeling was examined. The highest LIs were in the pieces of ureter neighboring the ligature with successively lower indices as the distance from the ligature increased. Factors potentially responsible for the changes in the LI in different parts of the urinary tract are considered, and conclusions about the mechanisms involved are tentatively drawn.

A histopathological study of the effects of intravenously administered lambda carrageenan in the mouse, with particular reference to the macrophage system.

Intravenously administered lambda-carrageenan rapidly precipitates in the marginal zone of the spleen, the hepatic sinuses and the capillaries of the heart, lung, kidney and adrenal gland. Extensive coagulative necrosis of the liver and myocardium is seen at 24 h. Phagocytosis occurs at 3 days, and is associated with transformation of the lymphocytes of the splenic white pulp. Circulating carrageenan-containing macrophages adhere to vascular endothelium in the lung and at 6 days are situated beneath it. At 30 days carrageenan granulomas have formed in the spleen and liver, probably as a result of macrophage recirculation.

Latent injury in frozen-thawed bacteriophage T4Bo.

Two interesting new phenomena have been observed in suspensions of T4Bo bacteriophage which were frozen to temperatures below the eutectic temperature of the salt (sodium chloride) in the suspending medium. Approximately 10% of the phage appeared to survive such a phase change as determined by plaque titre. However, exposure of these survivors to ultrasonic vibration or repeated freezing showed them to be hypersensitive and thus latently injured. The hypersensitivity was lost on incubating the phage at 37 degrees C. for 3 hr. Furthermore, following a eutectic phase change, the surviving phage could be inactivated by rapid cooling to -90 degrees C. followed by slow rewarming. Such inactivation cannot be accounted for by accepted theories of freezing injury.

Morphological manifestations of freezing and thawing injury in bacteriophage T4Bo.

Electron microscopic observation of negatively stained preparations of frozen and thawed suspensions of T4Bo phage clearly separated the morphological changes produced produced by low-temperature salt denaturation from those produced by eutectic phase changes. Salt denaturation caused contraction of tail sheaths. Eutectic phase changes appeared to cause two separate lesions. Firstly the tail sheath was disjointed 18-22 nm. below the collar and the tail core was disjointed at 40-60 nm. below the collar, giving rise to separated heads with a small tail remnant, and separated tails in which the sheath remarkably remained in its extended form. Secondly, tears were seen in the head membranes of particles with collapsed empty heads. In all the experiments the percentage of normal phage particles counted electron-microscopically was close to the percentage of viable phage as determined by plaque assay.

Prevention of low temperature denaturation injury in T4Bo phage by low concentrations of traditional cryoprotective additives.

The well known cryoprotective additives glucose, sucrose, glycerol, dimethyl sulphoxide, polyvinylpyrrolidone, dextran and ammonium acetate have been found to prevent inactivation of T4Bo phage frozen in sodium bromide solutions. Their protective effects in this experimental system could not be accounted for by a colligative mechanism. It is proposed that they may act by modifying the structure of the unfrozen aqueous phase rather than by direct interaction with the phage.

Osmotic injury in rapidly thawed T4 bacteriophage.

Osmotic injury in frozen-thawed T4 phage was caused by the sudden and large fall in the electrolyte concentration of the unfrozen aqueous phase during rapid thawing of frozen samples. In accordance with the classical interpretation of osmotic shock it was found that DNA was quantitatively liberated from T4 phage inactivated by the osmotic injury of rapid thawing.The degree of inactivation of osmotically shocked T4 phage was temperature dependent, being much increased by lowering the temperature, but was independant of the pH of the suspending medium. The T4Bo osmotic shock-resistant phage was refractory to the osmotic injury of rapid thawing.

Protection of T4 bacteriophage against inactivation during freezing and thawing by addition of peptides.

Peptides of rabbit globin produced by tryptic digestion, were found to be highly protective against inactivation of freeze-thawed T4 phage. In concentrations of about 10(-3) M the peptides protected the phage against inactivation by both concentrated NaBr in the unfrozen aqueous phase and the eutectic phase change.Fractionation of the peptides by G25 Sephadex showed that peptide concentration rather than peptide size was the more important factor in determining the degree of protection of the phage by electrolyte effects. In contrast, protection against eutectic injury was strongly dependent on peptide size.Possible mechanisms of action of the protective peptides are discussed.