Safety of labor, Valsalva maneuver, and neuraxial anesthesia for pregnant women after decompressive craniectomy: Case series and review of the literature.

Decompressive craniectomies are a neurosurgical operation aimed at normalizing intracranial pressure (ICP). Occasionally, there is delayed replacement of the skull resulting in an acquired skull defect. When managing laboring patients with an acquired skull defect there is often fear associated with traditional labor involving the Valsalva maneuver and with neuraxial anesthesia. These fears typically stem from potential ICP changes and risk of herniation. In reviewing the literature, only 15 cases are described detailing labor management after decompressive craniectomy (DC), mostly with incomplete labor histories. We aim to expand that literature by reporting two cases of safe labor with epidural anesthesia in patients with large skull defects. The first described patient underwent a cranioplasty during pregnancy because of trauma. Later, because of concerns for pre-eclampsia, induction of labor was initiated and she received neuraxial anesthesia via epidural. The patient ultimately underwent cesarean delivery 48 h after induction began due to nonreassuring fetal heart tones. The second patient underwent a cranioplasty because of infection prior to pregnancy. Once in labor, she was cleared by neurosurgery and the anesthesia team placed her epidural. She later underwent an uncomplicated standard vaginal delivery. The existing literature on labor following DC is sparse. Retrospective review of case reports can advance discussion and standardization regarding care for laboring women with a history of DC. We advocate that the Valsalva maneuver and epidural anesthesia is safe for pregnant women who are neurologically asymptomatic.

An Understated Comorbidity: The Impact of Homelessness on Traumatic Brain Injury.

Traumatic brain injury (TBI), a neurovascular injury caused by external force, is a common diagnosis among veterans and those experiencing homelessness (HL). There is a significant overlap in the veteran and homeless population, possibly accounting for the two to seven times greater incidence of TBI among those experiencing HL than the general population. Despite these statistics, individuals experiencing HL are often underdiagnosed and ineffectively treated for TBI. We introduced a novel model of HL. Over 5 weeks, adult Sprague-Dawley rats were randomly assigned to one of the following conditions: TBI only, HL only, TBI + HL, or control (n = 9 per group). To emulate HL, animals (2 animals per cage) were exposed to soiled beddings for 5 weeks. Subsequently, animals were introduced to TBI by using the moderate controlled cortical impact model, then underwent 4 consecutive days of behavioral testing (beam walk (BW), elevated body swing test (EBST), forelimb akinesia (FA), paw grasp (PG), Rotorod, and elevated T-maze). Nissl staining was performed to determine the peri-impact cell survival and the integrity of corpus callosum area. Motor function was significantly impaired by TBI, regardless of housing (beam walk or BW 85.0%, forelimb akinesia or FA 104.7%, and paw grasp or PG 100% greater deficit compared to control). Deficits were worsened by HL in TBI rats (BW 93.3%, FA 40.5%, and PG 50% greater deficit). Two-way ANOVA revealed BW (F(4, 160) = 31.69, p < 0.0001), FA (F(4, 160) = 13.71, p < 0.0001), PG (F(4, 160) = 3.873, p = 0.005), Rotorod (F(4, 160), p = 1.116), and EBST (F(4, 160) = 6.929, p < 0.0001) showed significant differences between groups. The Rotorod and EBST tests showed TBI-induced functional deficits when analyzed by day, but these deficits were not exacerbated by HL. TBI only and TBI + HL rats exhibited typical cortical impact damage (F(3,95) = 51.75, p < 0.0001) and peri-impact cell loss compared to control group (F(3,238) = 47.34, p < 0.0001). Most notably, TBI + HL rats showed significant alterations in WM area measured via the corpus callosum (F(3, 95) = 3.764, p = 0.0133). Worsened behavioral outcomes displayed by TBI + HL rats compared to TBI alone suggest HL contributes to TBI functional deficits. While an intact white matter, such as the corpus callosum, may lessen the consequent functional deficits associated with TBI by enhancing hemispheric communications, there are likely alternative cellular and molecular pathways mitigating TBI-associated inflammatory or oxidative stress responses. Here, we showed that the environmental condition of the patient, i.e., HL, participates in white matter integrity and behavioral outcomes, suggesting its key role in the disease diagnosis to aptly treat TBI patients.

Single-particle cryo-EM analysis of the shell architecture and internal organization of an intact α-carboxysome.

Carboxysomes are proteinaceous bacterial microcompartments that sequester the key enzymes for carbon fixation in cyanobacteria and some proteobacteria. They consist of a virus-like icosahedral shell, encapsulating several enzymes, including ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO), responsible for the first step of the Calvin-Benson-Bassham cycle. Despite their significance in carbon fixation and great bioengineering potentials, the structural understanding of native carboxysomes is currently limited to low-resolution studies. Here, we report the characterization of a native α-carboxysome from a marine cyanobacterium by single-particle cryoelectron microscopy (cryo-EM). We have determined the structure of its RuBisCO enzyme, and obtained low-resolution maps of its icosahedral shell, and of its concentric interior organization. Using integrative modeling approaches, we have proposed a complete atomic model of an intact carboxysome, providing insight into its organization and assembly. This is critical for a better understanding of the carbon fixation mechanism and toward repurposing carboxysomes in synthetic biology for biotechnological applications.

Structure and assembly of cargo Rubisco in two native α-carboxysomes.

Carboxysomes are a family of bacterial microcompartments in cyanobacteria and chemoautotrophs. They encapsulate Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) and carbonic anhydrase catalyzing carbon fixation inside a proteinaceous shell. How Rubisco complexes pack within the carboxysomes is unknown. Using cryo-electron tomography, we determine the distinct 3D organization of Rubisco inside two distant α-carboxysomes from a marine α-cyanobacterium Cyanobium sp. PCC 7001 where Rubiscos are organized in three concentric layers, and from a chemoautotrophic bacterium Halothiobacillus neapolitanus where they form intertwining spirals. We further resolve the structures of native Rubisco as well as its higher-order assembly at near-atomic resolutions by subtomogram averaging. The structures surprisingly reveal that the authentic intrinsically disordered linker protein CsoS2 interacts with Rubiscos in native carboxysomes but functions distinctively in the two α-carboxysomes. In contrast to the uniform Rubisco-CsoS2 association in the Cyanobium α-carboxysome, CsoS2 binds only to the Rubiscos close to the shell in the Halo α-carboxysome. Our findings provide critical knowledge of the assembly principles of α-carboxysomes, which may aid in the rational design and repurposing of carboxysome structures for new functions.

Medical management of phimosis in children: our experience with topical steroids.

PURPOSE: Circumcision has traditionally been regarded as primary therapy for persistent phimosis in boys. Recently groups in Europe and Australia have advocated the use of topical steroids as conservative treatment in children. We report our experience with this approach. MATERIALS AND METHODS: Between July 1997 and February 1998, 25 boys with a mean age of 8.3 years who presented to our clinic with phimosis were started on a topical steroid. After counseling the family regarding treatment options we prescribed a 1-month course of 0.05% betamethasone cream applied twice daily. RESULTS: Of the 25 patients 24 completed the treatment and were evaluated. A total of 16 boys (67%) had a normal appearing foreskin that was easily retracted, while in the remaining 8 the outcome was unsuccessful and circumcision was scheduled. CONCLUSIONS: Our study demonstrates that the application of topical steroids is a viable alternative for treating phimosis in children. Appropriate candidates for this therapy include boys older than 3 years who have persistent phimosis and no evidence of infection.

Response of filtered eyes to digital ocular pressure.

PURPOSE: To examine the effect of digital ocular pressure (DOP) on the intraocular pressure (IOP) of eyes 3 months or longer after successful glaucoma filtering surgery. METHODS: Fifteen patients participated in this study. Each had one eye with a successful filtering operation (IOP < or = 21 mmHg without medications) and a fellow eye that was not operated on, which served as a control. The authors measured IOP in both eyes before and serially after DOP until return to baseline or for 3 hours to determine the amounts and durations of reductions. The authors monitored changes of bleb morphology and searched for complications. RESULTS: Digital ocular pressure 3 months or more after successful filtering surgery reduced IOP by approximately 50% of baseline. The time after DOP for 50% of eyes to have intraocular pressure return to within 2 mmHg of baseline was 95 minutes; 40% recovered within 20 minutes and 30% had not recovered by 3 hours. Eyes with localized blebs recovered faster than did eyes with diffuse blebs. Transient shallowing of the anterior chamber developed in one eye. Otherwise, there were no adverse effects. Time since surgery and baseline IOP were not correlated with response. Fellow eyes had minimal response to DOP and recovered within 30 minutes. CONCLUSION: This study shows that a substantial, transient decrease of IOP after DOP occurs in glaucomatous eyes with a well-functioning bleb 3 months to 6 years after filtering surgery. The duration exceeds 90 minutes in more than 50% of the eyes tested and 180 minutes in more than 30% of the eyes tested.

Psychosis and substance abuse: cause, effect or coincidence?

An association between substance abuse and major psychiatric illness is increasingly well recognised, but most studies have been conducted in the USA and have focussed upon patients with schizophrenia rather than other disorders. We conducted a survey of 38 consecutively admitted patients with DSM-III-R functional psychoses. A semi-structured substance abuse interview was administered and a urine specimen for drug metabolite screening requested. The prevalence of cigarette smoking (63%) and current illicit drug use (26%) were higher than general population norms. The 16 subjects with schizophrenia and related disorders were more likely to smoke cigarettes than the 22 patients with an affective disorder (p = 0.008, odds ratio 8.4, 95% Cl 1.3-69.6), and showed tendencies to more illicit drug and alcohol consumption. Illicit drug users were more likely to have a forensic history and less likely to have entered further education. Substance abuse is common among patients with psychoses, particularly in those with schizophrenia and related disorders. All psychotic patients should have a detailed drug history taken, and therapeutic attempts made to reduce consumption.

Acute subdural haematoma in a neonate.

A male child of Jordanian parentage who was born in an ambulance was immediately admitted to Al-Adan Hospital, Kuwait, with left parietal cephalhaematoma. Two days later he started to convulse on the right side of the body and was found to have a dilated left pupil and spastic right leg. A computed tomographic brain scan showed a large subdural haematoma which extended from the posterior interhemispheric fissure to cover the left convexity of the brain (type II of Hayashi et al. [6]). The subdural haematoma was removed through a left temporoparietal craniectomy. The child had a smooth postoperative recovery and was in a neurologically satisfactory condition during a 16-month follow-up period.

Confidence intervals for post-test probability.

Confidence intervals are a natural way to describe the uncertainty of post-test probability in diagnostic tests. We consider confidence intervals for two different scenarios. At a site, for example, hospital emergency room or student health centre, with measured values of disease prevalence, sensitivity and specificity available, the confidence interval is similar to results in the literature, but at a site where measured values of these indices are unavailable, we develop a method, using the values of disease prevalence, sensitivity and specificity from other sites, to obtain a confidence interval for post-test probability. We use the diagnosis of strep throat to illustrate the results. We also obtain confidence intervals from simulations to compare with the results of both scenarios.

The evolution of a biodegradable membrane for use in urological surgery. A summary of 109 in vivo experiments.

The evolution of a collagen/vicryl composite membrane designed as a prosthetic material for use in urinary tract surgery is described. The early experiments in which collagen film alone was used to repair experimental ureterotomies are reviewed together with our first experiments with the collagen/vicryl prosthesis in the repair of partial nephrectomies and of full thickness defects created in the urinary bladder of experimental rabbits. These early results led to the preparation of a composite using a more highly purified collagen and employing a method of sterilisation (gamma irradiation) which would be acceptable for regular use in medical products. The results of a further series of partial nephrectomy and full thickness bladder repairs show that irradiation does not compromise the efficacy of the collagen/vicryl composite in vivo.

The in-vitro assessment of a collagen/vicryl (polyglactin) composite film together with candidate suture materials for potential use in urinary tract surgery. III. Adherence of bacteria to the material surface.

A Collagen/Vicryl (Polyglactin) composite membrane (developed for use in urinary tract surgery) has been incubated in cultures of radioactively labelled urinary tract pathogens vis Escherichia coli, Staphylococcus epidermidis, and Proteus mirabilis for up to 1 h. For comparison, collagen film, Vicryl mesh, and a number of absorbable and non-absorbable sutures were similarly tested. Following incubation, samples were also examined by scanning electron microscopy. Under the experimental conditions employed, only minimal adherence of the micro-organisms to the collagen coated Vicryl mesh, its two individual components, as well as Vicryl and nylon sutures was observed. Significantly greater numbers of bacteria, however, adhered to silk and Chromic Catgut. The results suggest that adherence of microorganisms to the prosthesis even in infected urine is unlikely to develop into a microcolony of bacteria. However, it should be emphasised that great care must be exercised when extrapolating from the in-vitro to the in-vivo situation.

The in-vitro assessment of a collagen/vicryl (polyglactin) composite film together with candidate suture materials for use in urinary tract surgery. II. Surface deposition of urinary salts.

Collagen coated vicryl mesh has been incubated with a series of urine collections from healthy and stone-forming patients. For comparison, collagen film, vicryl mesh, and a number of absorbable and non-absorbable sutures were similarly tested. Incubation in rabbit urine were also included in the study. Deposition of urinary salts, estimated qualitatively by electron microscopy, were observed on the collagen vicryl composite in approximately two thirds of the urines tested including rabbit urine. Those urines from patients with a high calcium excretion in particular caused urinary deposits on the material. Similar results were obtained with collagen film although the latter was not tested in rabbit urine. Considerably less deposits of urinary constituents were found with other absorbable materials such as vicryl mesh, vicryl sutures, and chromic catgut, whereas a higher proportion of concretions were found with the non-absorbable sutures. The results indicate that urinary salt deposition may be a problem associated with collagen based composite materials after prolonged exposure to urine. It must, however, be emphasised that great care should be exercised when extrapolating any results obtained in-vitro to the in-vivo situation.

Renal scarring secondary to vesicoureteric reflux. Critical assessment and new grading.

One hundred and fifty children with proven urinary tract infection who were assessed by renal ultrasound (U/S), intravenous urography (IVU) and dimercaptosuccinic acid (99mTc DMSA) scan, were studied to identify the sensitivity of each examination and the pick-up rate of renal scarring secondary to vesicoureteric reflux. Sixty-three of these children who had the examinations carried out within a 6-month period were assessed in detail. A DMSA scan is the most accurate method of detecting early renal scars in the young age group (0-2 and 2-5 years), followed by ultrasound. The examinations are equally sensitive over the age of 5. A new grading system of the severity of renal scarring is presented.

Unusual finger tip injury in children.

We report two children with finger tip ischaemia resulting from woollen mittens. Ischaemia has progressed to gangrene and required amputation of the affected finger.

An assessment of a collagen/vicryl composite membrane to repair defects of the urinary bladder in rabbits.

Collagen/vicryl (Polyglactin) composite membrane has been used to repair full-thickness defects in the urinary bladder of rabbits. The material has been shown to be biodegradable, prevent leakage of urine, and is readily replaced by collagenous scar tissue lined with a urothelium. Regeneration of smooth muscle has been observed in the repair area of some animals. The results suggest that such a material may well be of use to urologists wishing to augment contracted bladders or in the repair of bladder fistulae in human subjects, thereby avoiding the use of bowel or other material e.g. omentum.

The use of a biodegradable collagen/vicryl composite membrane to repair partial nephrectomy in rabbits.

A composite membrane produced from collagen and vicryl mesh has been used to cover the kidney surface following partial nephrectomy in rabbits. The membrane readily held sutures, gave satisfactory haemostasis, and prevented leakage of urine. The experiments showed that the prosthesis biodegraded in less than twenty weeks. The only observed long-term effect of the material was thickening of the renal capsule. The results indicate that this membrane may be a suitable reparative material for use in traumatised kidneys in humans.

The in vitro assessment of a collagen/vicryl (polyglactin) composite film together with candidate suture materials for use in urinary tract surgery. I. Physical testing.

A Vicryl (Polyglactin)/Collagen composite membrane has been developed for potential use in urinary tract surgery. The compatability of this membrane, together with its two individual components, collagen film and vicryl mesh, has been tested over a three week period in urine obtained from both healthy and from stone forming patients. The rate of degradation as indicated by changes in the mechanical strength was determined at regular intervals. In addition, absorbable suture materials such as plain catgut, chromic catgut, and vicryl were similarly tested; in the latter case, the breaking stress, and actual loss of weight of the material were compared. The whole series of experiments were then repeated in urine obtained from rabbits, the animal chosen for any future in vivo studies.