The rhomboid flap for pilonidal disease

Introduction There have been many surgical techniques described for the treatment of pilonidal sinuses. Recurrent disease causes significant morbidity particularly with time from work. Aim To assess the rhomboid flap's role in promoting one‐stage primary healing in pilonidal disease and to evaluate the morbidity and recurrence. Methods Fifty‐three patients were prospectively recruited of which 27 had previous multiple abscess formation requiring surgical drainage from their pilonidal disease, although none had acute disease at the time of surgery. By using the transposition flap, we were able to obliterate the natal cleft and therefore the rolling action of the buttocks between the cleft in these patients and thereby remove one of the factors involved in pilonidal disease. Hospital stay, healing time, wound infection, wound breakdown and recurrence were noted. Results There were 47 males and 6 females with a median age of 28 years (range 16–64 years). Median follow‐up was 24 months (range 3–36 months). Post‐operative morbidity involved superficial wound infection in 7 (13%) which settled with out‐patient dressings. There were four recurrences (7%), two occurred between the flap and the anal canal, and the other two in the flap margin needing intervention. All the patients healed their wounds and the median healing time was 14 days. Conclusion As this condition affects a predominantly young population causing significant time off from work, we feel that the Rhomboid Flap is useful for difficult cases in that it allows early return to full activity and does not necessitate prolonged postoperative care.     

Differential effects of exercise and housing condition on murine natural killer cell activity and tumor growth.

Acute exercise and exercise conditioning have been shown to affect the activity of natural killer (NK) cells as well as the growth of experimentally induced tumors in animals. Since psychosocial factors are also known to alter NK activity and tumor growth, isolation, a known psychosocial stressor of mice, was also investigated to see if housing condition could alter exercise-induced changes in NK cell activity and tumor growth. NK cell activity and concentration of asialo GM1 (ASGM1) positive splenocytes were measured in male C3H mice inoculated i.v. with CIRAS 3 tumor cells. Mice were housed individually or in groups of four and trained to run for eight weeks on a rodent treadmill; controls remained sedentary throughout the experimental period. At four weeks into the training protocol, mice were injected with the tumor cells and continued to run for four weeks after tumor exposure. There was a significant effect of physical activity (p less than 0.019) but not of housing on splenic NK cytotoxicity against tumor targets in vitro. When the data were analyzed by presence or absence of lung metastases, only those animals without visible lung tumors had significantly higher NK activity as a function of exercise relative to sedentary controls. There were no significant differences in the frequency of ASGM1+ splenocytes between trained and untrained animals, irrespective of presence or absence of lung tumor colonies. There was a significant effect of housing (p less than 0.02), but not of physical activity, in mice with successful tumor takes with greater numbers of group housed animals (29/59) with tumor relative to individually housed animals (13/60).(ABSTRACT TRUNCATED AT 250 WORDS)     

Endometriosis: Endometriosis and infertility: raised iron concentration in the peritoneal fluid and its effect on the acrosome reaction

Endometriosis and infertility are commonly associated. Thisstudy investigated the role of accelerated lipid peroxidationof spermatozoa by the peritoneal fluid of patients with endometriosisas a cause for this association. It proposes that the increasediron concentration present in the fluid of these patients actsas a catalyst for the process. Peritoneal fluid from 25 patientswith endometriosis and 25 matched controls was obtained at laparoscopy.Spermatozoa were incubated in the fluid from both groups andthe subsequent acrosome reaction rates analysed. The relationshipbetween these results and iron concentration in the fluid wasexamined. A significant decrease in the acrosome reaction ratewas seen in the endometriotic group(P = 0.034). Overall, a decreasein the acrosome reaction rate was associated with an increasediron concentration in the fluid(18 of the 25 pairs). In milddisease, (six of 11 pairs), the relationship was not as markedas that in severe disease (12 of 14 pairs). These results suggestthat the peritoneal fluid in patients with endometriosis hasa detrimental action on the acrosome reaction of spermatozoain vitro.     

Endometriosis and Race

The pelvic findings of 202 infertile women undergoing diagnostic laparoscopy in Kuala Lumpur, Malaysia were compared to that of 464 infertile women undergoing diagnostic laparoscopy in Aberdeen, United Kingdom. Endometriosis was significantly more common in the women from Kuala Lumpur (51% against 22%, p less than 0.001). There was however no significant difference seen in the severity of the disease (AFS Classification, 1985). These findings confirm our clinical impression that endometriosis is more common in Asian women when compared to Caucasian women.     

NMDA receptors regulate developmental gap junction uncoupling via CREB signaling

Signaling through gap junctions (electrical synapses) is important in the development of the mammalian central nervous system. Abundant between neurons during postnatal development, gap junction coupling subsequently decreases and remains low in the adult, confined to specific subsets of neurons. Here we report that developmental uncoupling of gap junctions in the rat hypothalamus in vivo and in vitro is associated with a decrease in connexin 36 (Cx36) protein expression. Both developmental gap junction uncoupling and Cx36 downregulation are prevented by the blockade of NMDA glutamate receptors, action potentials and the calcium-cyclic AMP response element binding protein (CREB), and are accelerated by CREB overexpression. Developmental gap junction uncoupling and Cx36 downregulation are not affected by blockade of non-NMDA glutamate receptors, and do not occur in hypothalamic neurons from NMDA receptor subunit 1 (NMDAR1) knockout mice. These results demonstrate that NMDA receptor activity contributes to the developmental uncoupling of gap junctions via CREB-dependent downregulation of Cx36.     

Mutagenesis studies of the major benzo[a]pyrene N2-dG adduct in a 5'-TG versus a 5'-UG sequence: removal of the methyl group causes a modest decrease in the [G->T/G->A] mutational ratio

The potent mutagen/carcinogen benzo[a]pyrene (B[a]P) is metabolically activated to (+)-anti-B[a]PDE, which induces a full spectrum of mutations primarily at the G:C base pairs (e.g. GC-->TA, GC-->AT, etc.). Each of these mutations can be induced by its major adduct [+ta]-B[a]P-N(2)-dG, where DNA sequence context appears to influence both the quantitative and qualitative pattern of mutagenesis. We noted previously that 5'-TG sequences tend to have a higher fraction of G-->T mutations for both [+ta]-B[a]P-N(2)-dG and (+)-anti-B[a]PDE in comparison with 5'-CG, 5'-GG or 5'-AG sequences. To investigate a possible structural element for this trend, the role (if any) of the methyl group on the 5'-T is considered. Using adduct site-specific means, the [G-->T/G-->A] mutational ratio for [+ta]-B[a]P-N(2)-dG is determined to be approximately 1.08 in a 5'-TGT sequence, and approximately 0.60 in a 5'-UGT sequence. (G-->C mutations are minor.) Although this modest approximately 1.8-fold decrease in [G-->T/G-->A] ratio is statistically significant (P = 0.03), it suggests that the methyl group on the 5'-T is not the main reason why a 5'-T tends to enhance G-->T mutations. This study was prompted by an adduct conformational hypothesis, which predicted that the removal of the methyl group in a 5'-TG sequence would lower the fraction of G-->T mutations; however, the approximately 1.8-fold decrease is too small to do additional experiments to assess whether this conformational hypothesis, or other hypotheses, are the true cause of the decrease, which is discussed in this paper.     

Mutagenesis studies with four stereoisomeric N2-dG benzo[a]pyrene adducts in the identical 5'-CGC sequence used in NMR studies: G->T mutations dominate in each case

Benzo[a]pyrene (B[a]P) is a polycyclic aromatic hydrocarbon (PAH) and a potent mutagen/carcinogen found ubiquitously in the environment. B[a]P is primarily metabolized to diol epoxides, which react principally at N2-dG in DNA. B[a]P-N2-dG adducts have been shown to induce a variety of mutations, notably G-->T, G-->A, G-->C and -1 frameshifts. Four stereoisomers of B[a]P-N2-dG (designated: [+ta]-;, [+ca]-, [-ta] and [-ca]) were studied by NMR in duplex 11mers in a 5'-CGC sequence context, and each adopted a different adduct conformation (Geacintov, et al. (1997) Chem. Res. Toxicol., 10, 111). Herein these four identical B[a]P-containing 11mers are built into duplex plasmid genomes and mutagenesis studied in Escherichia coli following SOS-induction. In nucleotide excision repair (NER) proficient E.coli, no adduct-derived mutants are detected. In NER deficient E.coli, G-->T mutations dominate for all four stereoisomers [+ta]-, [+ca]-, [-ta] and [-ca]-B[a]P-N(2)-dG, and mutation frequency is similar. Thus, the mutagenic pattern for these four B[a]P-N2-dG stereoisomers is the same, in spite of the fact that they adopt dramatically different conformations in ds-oligonucleotides as determined by NMR. These findings suggest that adduct conformation must be fluid enough in the 5'-CGC sequence that the duplex DNA conformation can interconvert to mutagenic and non-mutagenic conformations during lesion-bypass. A comparison of all published studies with these four B[a]P-N2-dG stereoisomers in E.coli reveals that B[a]P-N2-dG adduct stereochemistry tends to have a lesser impact on mutagenic pattern (e.g. G-->T versus G-->A mutations) than does DNA sequence context, which is discussed.     

Toll-like receptor 2 mediates inflammatory cytokine induction but not sensitization for liver injury by Propioni- bacterium acnes

Recognition of Gram-positive bacteria by Toll-like receptor 2 (TLR2) induces activation of proinflammatory pathways. In mice, sensitization with the Gram-positive Propionibacterium acnes followed by a challenge with the TLR4 ligand, lipopolysaccharide (LPS), results in fulminant hepatic failure. Here, we investigated the role of TLR2 in liver sensitization to LPS-induced injury. Stimulation of Chinese hamster ovary cells and peritoneal macrophages with heat-killed P. acnes required expression of TLR2 but not of TLR4, suggesting that P. acnes was a TLR2 ligand. Cell activation by P. acnes was myeloid differentiation primary-response protein 88 (MyD88)-dependent, and it was augmented by coexpression of CD14 in mouse peritoneal macrophages. In vitro, P. acnes behaved as a TLR2 ligand and induced TLR4 hetero- and TLR2 homotolerance in peritoneal macrophages. In vivo priming of wild-type mice with P. acnes, but not with the selective TLR2 ligands peptidoglycan and lipotheicoic acid, resulted in hepatocyte necrosis, hyperelevated serum levels of tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-6, interferon-gamma (IFN-gamma), and IL-12 (p40/p70), and increased RNA expression of proinflammatory cytokines (IL-12p40, IL-1alpha, IL-6, IL-1beta, IL-18, IFN-gamma) in the liver after a LPS challenge. Furthermore, P. acnes priming sensitized TLR2-deficient (TLR2-/-) but not MyD88-/- mice to LPS-induced injury, evidenced by hepatocyte necrosis, increased levels of serum TNF-alpha, IFN-gamma, IL-6, and liver proinflammatory cytokine mRNA expression. IFN-gamma, a cytokine sensitizing to endotoxin, was induced by P. acnes in splenocytes of TLR2-/- and TLR9-/- but not MyD88-/- mice. These results suggest that although P. acnes triggers TLR2-mediated cell activation, TLR2-independent but MyD88-dependent mechanisms mediate in vivo sensitization by P. acnes for LPS-induced liver injury.     

Acrolein-Induced Toxicity—Defective Mitochondrial Function as a Possible Mechanism

Administration of acrolein (2.5 mg/kg body weight/day) to rats for 45 days depleted the glutathione level in liver, which triggered an imbalance in the antioxidant defense, resulting in lipid peroxidation. Enhanced lipid peroxidation damaged the membranous structure of mitochondria, which was indicated by the loss of lamellae, and increased the oxidation of exogenously added NADH. Loss in membrane integrity altered the activities of the tricarboxylic acid cycle enzymes and levels of cytochromes. Decreased rate of ADP—stimulated oxygen uptake, respiratory coupling ratio, and ATP synthesis—were also observed. We report that the acrolein-induced toxicity is mediated through the depletion of GSH leading to impairment of rat liver mitochondrial function. Received: 24 November 1998     

Are obstetric risk factors and bowel symptoms associated with defaecographic and manometric abnormalities in women awaiting hysterectomy?

Abdominal hysterectomy has been shown to affect anorectal function. These studies are either population-based or have been performed retrospectively. It is not clear from the literature whether those subjects awaiting hysterectomy already have an element of pelvic floor failure and which may be related to obstetric risk factors. A complete anorectal assessment was performed in a group of women awaiting hysterectomy who did not volunteer any bowel symptoms. The patients studied were part of an ongoing study of the functional effects of abdominal hysterectomy. All had their anorectal function assessed before their respective surgery by a questionnaire (functional bowel score), Cleveland continence score, endoanal ultrasound (U/S), anal manometry, defaecatory proctogram and colonic transit. A detailed obstetric history, which included risk factors such as parity, type of delivery, duration of labour and elevated birth weight, were also recorded. Patients with previous bowel disease, bowel surgery and anal sphincter repair were excluded. There were 39 subjects with a median age of 43 years (range 31-65), respectively. Thirty-three rectocoeles and 22 intussusceptions were demonstrated. Two had poor puborectalis function, while five had cough incontinence. Two women had abnormal colonic transit. Thirteen had abnormal anal manometry. Endoanal ultrasound was normal in all patients. None of the obstetric risk factors were associated with rectocoele, intussusception or abnormal anal manometry. Low squeeze pressure was associated significantly with more bowel symptoms (P=0.03). However, rectocoele, intussusception, abnormal colonic transit, abnormal resting anal pressure and maximal tolerated volume were not statistically significantly associated with bowel symptoms. The majority of female subjects who were awaiting hysterectomy had physiological and proctographic abnormalities consistent with pelvic floor failure. Obstetric risk factors were not associated with rectocoele, intussusception, abnormal colonic transit and anal manometry in this cohort of patients. Similarly, the majority of proctographic abnormalities were not associated with bowel symptoms. However, a trend was noted associating bowel symptoms with manometric abnormalities.