Aberrant gut-microbiota-immune-brain axis development in premature neonates with brain damage

Premature infants are at substantial risk for suffering from perinatal white matter injury. Though the gut microbiota has been implicated in early-life development, a detailed understanding of the gut-microbiota-immune-brain axis in premature neonates is lacking. Here, we profiled the gut microbiota, immunological, and neurophysiological development of 60 extremely premature infants, which received standard hospital care including antibiotics and probiotics. We found that maturation of electrocortical activity is suppressed in infants with severe brain damage. This is accompanied by elevated γδ T cell levels and increased T cell secretion of vascular endothelial growth factor and reduced secretion of neuroprotectants. Notably, Klebsiella overgrowth in the gut is highly predictive for brain damage and is associated with a pro-inflammatory immunological tone. These results suggest that aberrant development of the gut-microbiota-immune-brain axis may drive or exacerbate brain injury in extremely premature neonates and represents a promising target for novel intervention strategies.

Ascending Vaginal Infection Using Bioluminescent Bacteria Evokes Intrauterine Inflammation, Preterm Birth, and Neonatal Brain Injury in Pregnant Mice

Preterm birth is a serious global health problem and the leading cause of infant death before 5 years of age. At least 40% of cases are associated with infection. The most common way for pathogens to access the uterine cavity is by ascending from the vagina. Bioluminescent pathogens have revolutionized the understanding of infectious diseases. We hypothesized that bioluminescent Escherichia coli can be used to track and monitor ascending vaginal infections. Two bioluminescent strains were studied: E. coli K12 MG1655-lux, a nonpathogenic laboratory strain, and E. coli K1 A192PP-lux2, a pathogenic strain capable of causing neonatal meningitis and sepsis in neonatal rats. On embryonic day 16, mice received intravaginal E. coli K12, E. coli K1, or phosphate-buffered saline followed by whole-body bioluminescent imaging. In both cases, intravaginal delivery of E. coli K12 or E. coli K1 led to bacterial ascension into the uterine cavity, but only E. coli K1 induced preterm parturition. Intravaginal administration of E. coli K1 significantly reduced the proportion of pups born alive compared with E. coli K12 and phosphate-buffered saline controls. However, in both groups of viable pups born after bacterial inoculation, there was evidence of comparable brain inflammation by postnatal day 6. This study ascribes specific mechanisms by which exposure to intrauterine bacteria leads to premature delivery and neurologic inflammation in neonates.

Requirements for Pseudomonas aeruginosa acute burn and chronic surgical wound infection

Opportunistic infections caused by Pseudomonas aeruginosa can be acute or chronic. While acute infections often spread rapidly and can cause tissue damage and sepsis with high mortality rates, chronic infections can persist for weeks, months, or years in the face of intensive clinical intervention. Remarkably, this diverse infectious capability is not accompanied by extensive variation in genomic content, suggesting that the genetic capacity to be an acute or a chronic pathogen is present in most P. aeruginosa strains. To investigate the genetic requirements for acute and chronic pathogenesis in P. aeruginosa infections, we combined high-throughput sequencing-mediated transcriptome profiling (RNA-seq) and genome-wide insertion mutant fitness profiling (Tn-seq) to characterize gene expression and fitness determinants in murine models of burn and non-diabetic chronic wound infection. Generally we discovered that expression of a gene in vivo is not correlated with its importance for fitness, with the exception of metabolic genes. By combining metabolic models generated from in vivo gene expression data with mutant fitness profiles, we determined the nutritional requirements for colonization and persistence in these infections. Specifically, we found that long-chain fatty acids represent a major carbon source in both chronic and acute wounds, and P. aeruginosa must biosynthesize purines, several amino acids, and most cofactors during infection. In addition, we determined that P. aeruginosa requires chemotactic flagellar motility for fitness and virulence in acute burn wound infections, but not in non-diabetic chronic wound infections. Our results provide novel insight into the genetic requirements for acute and chronic P. aeruginosa wound infections and demonstrate the power of using both gene expression and fitness profiling for probing bacterial virulence.

Soft tissue infections, such as those in burns, bed sores, and diabetic ulcers, are a significant healthcare and economic burden in the developed and developing world. The opportunistic pathogen P. aeruginosa can cause both acute and chronic infections, and the trajectory of these two types of infections is vastly different. We used high-throughput sequencing to profile P. aeruginosa genome-wide gene expression and mutant fitness during mouse model acute and non-diabetic chronic wound infections. Using these data, we show that wounds are nutrient-rich growth environments in which long-chain fatty acids are a primary source of carbon and energy. We also show that the ability to travel along spatio-chemical gradients by chemotaxis is critical for bacterial fitness and virulence in acute but not chronic infections. Our results demonstrate the utility of simultaneous mutant fitness and gene expression profiling to discover critical functions in complex growth environments.

[Treatment of full-thickness electric burn of skull combined with cerebral contusion and intracranial infection]

This article reports the treatment of a patient suffering from full-thickness electric burn of skull combined with cerebral contusion and intracranial infection to provide experience in treating such patients. Based on detailed analysis on patient's condition and CT results, several operations of surgery and anti-infection treatment were performed on the patient. The wounds healed 6 weeks after injury. The skull defect was repaired with three-dimensionally reconstructed titanium mesh of computer-aided design two years after wound healing. The treatment of full-thickness electric burn of skull combined with cerebral contusion was quite difficult. The timing and mode of operation were very important. Perioperative prevention and treatment of intracranial infection were essential to save the life of the patient. In the event of intracranial infection, effective systemic use of antibiotics, cerebrospinal fluid drainage, intrathecal injection of drugs, and the application of other comprehensive measures could ensure the success of treatment.

Microbiologic and histologic characteristics of the extremely preterm infant's placenta predict white matter damage and later cerebral palsy. the ELGAN study

Inflammatory phenomena seem to contribute to the occurrence of perinatal cerebral white matter damage and CP. The stimulus that initiates the inflammation remains obscure. One thousand two hundred forty-six infants born before the 28th postmenstrual week had a protocol ultrasound scan of the brain read concordantly by two independent sonologists. Eight hundred ninety-nine of the children had a neurologic examination at approximately 24-mo postterm equivalent. The placenta of each child had been biopsied under sterile conditions and later cultured. Histologic slides of the placenta were examined specifically for this study. Recovery of a single microorganism predicted an echolucent lesion, whereas polymicrobial cultures and recovery of skin flora predicted both ventriculomegaly and an echolucent lesion. Diparetic CP was predicted by recovery of a single microorganism, multiple organisms, and skin flora. Histologic inflammation predicted ventriculomegaly and diparetic CP. The risk of ventriculomegaly associated with organism recovery was heightened when accompanied by histologic inflammation, but the risk of diparetic CP was not. Low-virulence microorganisms isolated from the placenta, including common skin microflora, predict ultrasound lesions of the brain and diparetic CP in the very preterm infant. Organism recovery does not seem to be needed for placenta inflammation to predict diparetic CP.

Neuroinfections complicating foreign body implants after perinatal trauma or meningitis in 60 children

Meningitis after artificial implants in 60 children, mainly after foreign body infections (FBI) was caused more frequently by coagulase negative staphylococci and Ps. aeruginosa than other organisms and was significantly associated with perinatal trauma, hydrocephalus, haemorrhage or VLBW and had more neurologic sequels despite mortality was similar to other nosocomial meningitis.

Perinatal infections, prematurity and brain injury

PURPOSE OF REVIEW

The association between perinatal infection and brain injury is widely accepted but a cause-and-effect relationship has not yet been proven. This article summarizes available evidence and current primary publications for debate.

RECENT FINDINGS

Work completed during the review period has reinforced current understanding of perinatal infection, prematurity and brain injury. In animal experiments: lipopolysaccharides have been further implicated in brain injury, not only as a cause of brain injury but also as mediators of preconditioning and protection. Recent studies suggest that cerebral injury following low-dose lipopolysaccharide administration may become compensated in adulthood. Other studies have emphasized the complexity of the response by showing that plasma cytokine levels may not reflect those in the central nervous system or inflammatory events in the brain.

SUMMARY

Perinatal infection and maternofetal inflammation is strongly associated with preterm birth. Inflammation probably represents an important mechanism for cerebral damage, and both overt lesions and maldevelopment can result. Epidemiological data and multiple animal models to link infection, inflammation and brain damage exist, but proof of causation is elusive.

Dexamethasone decreases neurological sequelae and caspase activity

OBJECTIVE

To evaluate the use of dexamethasone in a model of meningitis-induced brain injury. Changes in neurobehavioral performance were the primary outcome variables. Changes in caspase activation and markers of neuronal injury were the secondary outcome variables.

DESIGN

Randomized, prospective animal study.

SETTING

University research laboratory.

SUBJECTS

Male Wistar rats.

INTERVENTIONS

Animals underwent a basilar cistern injection of either placebo or a suspension of Group B Streptococcus. Sixteen hours after inoculation, animals were randomized and received either dexamethasone or placebo in addition to antibiotics. Neurobehavioral performance and biological markers of brain injury were assessed at 3 days and 9 days after randomization. In a second experiment, caspase 1 and 3 were evaluated at 6 h, 24 h, and 72 h after dexamethasone administration.

MEASUREMENTS AND MAIN RESULTS

Neurobehavioral performance at 3 days and 9 days was significantly improved in the dexamethasone group. Serum C-tau and cerebral edema were decreased after 3 days of dexamethasone treatment. Dexamethasone decreased Caspase 3 activation in meningitic animals.

CONCLUSION

These findings demonstrate that dexamethasone decreases acute brain injury in a rat model of bacterial meningitis as measured by preservation of neurobehavioral performance.

Bacterial growth characteristics in craniocerebral gunshot wound of cat in a hot and humid environment

OBJECTIVE

To investigate the growth behavior of characteristics in craniocerebral gunshot wound of cats in a hot and humid environment.

METHODS

Twenty-three cross-bred cats were randomly divided into 4 groups: group A, the gunshot wound control group at normal temperature, in which tissue sampling was performed immediately after the wounding; group B, another gunshot wound control group at normal temperature, in which the samples were taken 6 h after the wounding; group C, the gunshot wound group subjected to a hot and humid environment, in which the tissue samples were obtained 6 h after the wounding; group D, the control group without undergoing the wound. The tissues from the wound tract and the surrounding tissues were sampled for bacterial culture and counting.

RESULTS

The bacterial counts of the tissues from the wound tract, the tissues within 5 mm and within 5-10 mm from wound tract varied insignificantly between groups A, B and C (P>0.05). In each group, the bacterial counts declined in the tissues as the distance of the sampling sites from the wound tract increased (P<0.01). The bacterial counts of the tissues from the wound tract and within 5 mm from the wound tract in group A, B and C were significantly different from those in group D (P<0.01).

CONCLUSION

Hot and humid environment does not significantly affect the bacterial growth in the craniocerebral gunshot wound within the first 6 h, which is a safe period against rapid bacterial growth and suitable for debridement.

The risk factors of nosocomial infection in severe craniocerebral trauma

OBJECTIVE

To explore the risk factors of nosocomial infection in severe craniocerebral trauma and the way of prevention.

METHODS

The clinical data of 387 patients with severe craniocerebral trauma were reviewed.

RESULTS

The total nosocomial infection rate of this study was 22.99%. Pulmonary nosocomial infection presented most frequently. The G-bacilli were the most common infectious bacteria. The mortality rate of the infection group was 38.20%.

CONCLUSIONS

Complications of nosocomial infection affect the prognosis of craniocerebral trauma patients. Nosocomial infection is related to the age of the patients, craniocerebral trauma severity, unreasonable utilization of antibiotics and invasive operations, such as tracheal cannula, mechanical ventilation, urethral catheterization and deep venous catheterization. Patients with severe craniocerebral trauma should be carefully treated and nursed to avoid nosocomial infection. In order to reduce the rate of nosocomial infection, intensive measurement should be adopted.

Chorioamnionitis and brain injury

The limited available evidence supports a strong association of chorioamnionitis with neonatal encephalopathy and CP in the term infant. The association of chorioamnionitis with depressed Apgar scores or neonatal seizures and with CP is equivocal in the preterm infant. Different study results may be related to differences in study populations, perhaps specifically to differences in susceptibility by stages of neurologic development as well as differences in gene frequencies associated with inflammation and thrombophilia. We require further understanding of the normal roles of cytokines in brain development, pregnancy, and inflammatory homeostasis before clinical interventions directed at cytokines, their receptors, or the inflammatory process are considered.

Perinatal infections and brain injury: current treatment options

Antimicrobial therapy can ameliorate infection and prevent long-term morbidity caused by several pathogens that infect the fetus and neonate. Ultimately, however, preventive strategies need to be developed and incorporated into routine preconceptional care. The future of prevention lies in immunizations, and if past and current successes with smallpox, polio, rubella, and measles vaccination programs are any indication, the future is bright for the developing fetus.

Microbial origin of glutamate, hibernation and tissue trauma: an in vivo microdialysis study

Using quantitative microdialysis in hibernating Arctic ground squirrels (AGS), striatal glutamate concentrations ([glu](dia)) progressively increased to approximately 200 microM after 3 days of microdialysis in euthermic but not hibernating ground squirrels. Initially, the progressive increase in [glu](dia) was thought to be related to greater tissue response in euthermic animals. Alternatively, given the vastly different body temperatures between the two groups (37 vs. 3 degrees C), glutamate might have originated from microbes, replicating at a faster rate in the warmer animals. To test these hypotheses, microdialysis was repeated using sterile technique and tissue response surrounding the probe tract was assessed in hematoxylin and eosin stained sections. Using sterile microdialysis technique, traumatic tissue response was greater in euthermic compared to hibernating tissue. However, sterile microdialysis abolished the progressive increase in glutamate. To confirm the microbial origin of glutamate we monitored [glu](dia) collected in vitro from probes immersed in glutamine-rich liquid medium incubated at 37 degrees C. In vitro, [glu](dia) increased as much as in vivo. Two bacteria isolated from in vitro dialysate and liquid medium were both identified as Ralstonia pickettii. Growth of these isolates as well as glutamate release was enhanced when glutamine rather than NH(4)NO(3) was added to the medium suggesting the bacteria utilize glutamine preferentially over ammonium as a nitrogen source.

Scedosporium apiospermum post-traumatic cranial infection

Scedosporium apiospermum is an environmental mould. Human infection caused by this organism is described more and more often. However, only a few case reports demonstrate its role as a telluric contaminant in patients affected by traumatism. This report is the case of a severe post traumatic infection by S. apiospermum in an immunocompetent young man. Surgical drainage associated with systemic therapy was successful.

Serum cleaved Tau protein and neurobehavioral battery of tests as markers of brain injury in experimental bacterial meningitis

Brain injury due to bacterial meningitis affects multiple areas of the brain with a heterogeneous distribution generating a challenge to assess severity. Tau proteins are microtubular binding proteins localized in the axonal compartment of neurons. Brain injury releases cleaved Tau proteins (C-tau) into the extracellular space where they are transported to the cerebral spinal fluid. We hypothesized that C-tau crosses the blood-brain barrier during inflammation and that it can be detected in serum. The correlation between serum C-tau levels and the extent of the meningitic insult was examined. Furthermore, we studied whether the use of a subset of neurobehavioral tasks can assess the extent of brain injury after meningitis. The tests were chosen primarily for their ability to detect deficits in the acoustic system, low brain, reflexive responding, as well as for impaired motor coordination and the higher brain functions of learning and memory. A rat model of group B streptococcal meningitis with variable severity was utilized. At five days after bacterial inoculation followed by antibiotic therapy neurobehavioral tests were performed and serum C-tau and histologic samples of the brain were obtained. Our study shows that during meningitis C-tau appears in serum and reflects the extent of neurologic damage. Neurobehavioral performance was altered after bacterial meningitis and could be correlated with histologic and biochemical markers of neurologic sequelae. We conclude that serum C-tau and a composite of neurobehavioral tests could become useful markers for assessing the severity of neurological damage in experimental bacterial meningitis.

[Clinical characteristics of burn caused by coal mine explosion]

OBJECTIVE

To investigate the characteristics of the burn injury caused by coal mine explosion so as to enhance the cure rate.

METHODS

Analyse the therapeutic result after planned standard treatment of clinical patients and review historical patients.

RESULTS

1. Coal mine explosion includes two types, i.e., gas explosion and coal dust explosion. 2. This kind of burn is a combined injury with pathologic changes of burns as the main feature. Mechanical injury is the chief cause of early death. Blast injury mainly damages the lungs. The occurrence of carboxyhemoglobinemia is not often. 3. The amount of fluid infusion in the first 24 h in exudation phase is 8% less of the traditional formula. Alkaline balanced salt solution is supplied as electrolyte solution, which can provide 45% of necessary HCO3- for correction of acidosis. 4. No thorough debridement is imposed in the treatment of burn wound. Baking with electric bulb with topical SD-Ag in semi-exposure state can be used. 5. Inhalation injury chiefly occurs in upper respiratory tract. The main bacterial species causing complicated lung infection are Pseudomonas aeruginosa and Staphylococcus aureus. 6. When MSOF occurs, the most frequently involved organ and system are the kidney and respiratory system. 7. The main bacteria causing systemic invasive infection are enteric bacilli and Pseudomonas aeruginosa. Enteric bacilli infection may be enterogenic. The latter infection is chiefly the result of cross infection in hospital.

CONCLUSION

The burn caused by coal mine explosion is a combined injury characterized by pathologic changes of burn as the main issue. This kind of burn has two types, i.e., gas-explosion-burn and coal-dust-explosion-burn.

Early intracranial infections after brain missile injuries--the role of computer tomography in diagnosis and treatment

During the war in Croatia, from August 1991 until December 1994, 138 soldiers were treated at the Split University Hospital for different brain injuries inflicted by missiles. Nine of these 138 patients developed intracranial infection. This retrospective study reports on the outcome of these 9 intracranial infections caused by penetrating missile head injuries. In case of clinically suspected infection, computerized tomography scan was obtained at two time points during the course of infection in the same patient. Scans were obtained with and without contrast media, 7 to 14 days after the injury and the 4 weeks later. The role of computerized tomography in the detection and follow-up of various intracranial infections and long-term consequences were evaluated.

[Brain injuries with abattoir guns]

The authors present a report on the treatment of 16 patients with brain injuries caused by a slaughterhouse gun. Nine patients had to be re-operated because of the presence of a foreign body; the primary operations of six patients were made in another surgical department. Two patients were re-operated twice. The reason for the first revision were bone fragments. The reason for the second revision was nasal liquorrhoea and posttraumatic hydrocephalus. Three patients (18.75%) of the investigated group died. The immediate cause of death was cerebral oedema. Eleven patients (68.75%) were referred for after-treatment to other health facilities, their condition had already improved. Two patients (12.5%) were referred in a poor, unaltered condition (coma). The rare incidence of gunshot injuries leads to a certain embarrassment how to treat patients with this type of injury. It was found that in gunshot wounds of the head and brain it is necessary to revise the gunshot canal from a craniotoic approach, remove foreign bodies, bone fragments, brain debris and then close perfectly the aperture in the dura mater, remove the margins of the bone contaminated with the injuring object and suture the skin. The authors draw attention to difficulties associated with localisation of the foreign body in the gunshot canal and possibilities of peroperative application of two-dimensional ultrasonography.

Analysis of 127 war inflicted missile brain injuries sustained in north-eastern Croatia

During the 4-year period (1991-1994) there were 127 consecutive patients with missile brain wound treated at the Division of Neurosurgery. They sustained brain injury in the region of east Slavonia, Baranya and north Bosnia, and were admitted mostly during the homeland defensive war in Croatia (1991-1992). Analysing the wounded, we divided them in two groups: "succumbed" (59 wounded) and "survivors" (68 wounded). We applied "less radical type of surgery", i.e. the patients were never re-operated only because of the retained single bone fragment. However, a retained cluster of bone fragments should be reoperated. The higher percentage of retained bone fragments (76.8%) is the result of precise visualization on the postoperative computed tomography (CT) scan. The last few cases have convinced us that the problem of the retained fragments could be solved by using an intraoprative ultrasonography. An intracranial (i.c.) infection (meningitis, abscess) occurred in 10 patients (10%), mostly among the patients who, besides the retained fragments, had cerebrospinal fluid (CSF) leak on the dehiscenced scalp wound. These cases should be reoperated soon after the CSF leak is visible on the dehiscenced wound. The overall mortality rate of 46.4% can be explained since our hospital was located close to the front-line, and some of severely wounded reached our hospital just in time to die. Excluding moribunds and those who died on the operating table (operated immediately after the admission), the mortality was 31.7%.

Posttraumatic meningitis: bacteriology, hydrocephalus, and outcome

To investigate the conditions that have developed in the treatment of posttraumatic meningitis with the use of new antibiotics, the authors studied cases with this infection retrospectively for a period of 68 months. Among 860 patients with moderate to severe head injuries, 12 (1.39%) sustained this complication. Of these, nine patients (75%) had a demonstrable basilar skull fracture and seven (58.3%) presented obvious rhinorrhea. Of these seven, four (57.1%) were treated conservatively and three (42.8%) finally underwent surgery for dural repair. The infecting agents were Gram-positive cocci (Staphylococcus haemolyticus, Staphylococcus warneri, Staphylococcus cohnii, Staphylococcus epidermidis, and Streptococcus pneumoniae) in five patients and Gram-negative bacilli in six patients (Escherichia coli in two, Klebsiella pneumoniae in two, and Acinetobacter anitratus in two). In one patient, the culture results were negative. All Gram-negative strains appeared resistant to ampicillin and third-generation cephalosporins, but sensitive to imipenem and to the quinolone ciprofloxacin. Gram-positive strains were sensitive to vancomycin. Hydrocephalus finally developed in the two patients who had received intrathecal infusions of amikacin. No other report of the relation of intrathecal infusion of antibiotics and the development of hydrocephalus was found. All patients survived, indicating that, for the present, posttraumatic meningitis is a nonfatal complication of head injury.

[The efficacy of Augmentin in suppurative complications in neurosurgery]

The results of clinical and laboratory studies on the use of augmentin in severe purulent complications after neurosurgical operations are presented. The laboratory studies carried out with the use of an automatic system Cobas Bact (Roch) showed that the numbers of the augmentin resistant strains of Staphylococcus and Enterobacteriaceae among the pathogens were 47 and an average of 64.5%, respectively. Gram-negative bacteria resistant to augmentin were 1.5 to 2 times less frequent than those resistant to amoxycillin. Still, they were much more frequent than those resistant to cefotaxime and ceftriaxone. Clinical efficacy of augmentin was studied in treatment of 39 patients with various affections of the brain such as tumors, trauma, vascular malformations and inflammatory processes. The postoperative complications were represented by meningitis, pneumonia, sepsis and their associations. The use of augmentin in the severe intra- and extracranial complications was favourable in 82.1% of the cases.

Comparative study of bacteriological contamination between primary and secondary exploration of missile head wounds

Aerobic and anaerobic bacterial contamination of scalp wounds, indriven bone fragments, and brain tracks were studied in two groups (A and B) of nonrandomized patients with missile head wounds in a 20-month study of patients from the front lines of the Iran-Iraq war. In the 53 Group B patients, the primary debridements, most of which had been performed within 24 hours after injury, were deemed insufficient and a secondary definitive exploration was performed. Group A patients (62) had primary definitive explorations at Nemazee Hospital after a mean of 66.5 hours since injury. All of the patients had been started on dexamethasone and a combination of either ampicillin and chloramphenicol or crystalline penicillin G and chloramphenicol after field evacuation. The contamination rate of scalp wounds, bone fragments and brain tracks was slightly higher in Group A (38.4%, 22.2%, and 29.6% respectively, for Group A and 31.9%, 19.5%, and 27% for Group B, respectively). Staphylococcus albus among the gram-positive and Acinetobacter among gram-negative bacteria were the most common infecting organisms. Fifty per cent of the bacteria cultured from the brain tracks of Group A and 30.8% of those cultured from Group B patients were gram-negative. A total of 125 patients in four groups was included in our overall study of victims of missile wounds that violated the dura mater. Four patients developed meningitis at Nemazee Hospital (3 postoperatively and 1 after facial penetration). Two patients in Group B were admitted with meningitis (1 with an accompanying abscess), 1 of them 20 days and the other 60 days after exploration at two different centers.(ABSTRACT TRUNCATED AT 250 WORDS)

[Prevention of wound infection in open skull and brain injuries]

Measures aimed at the prevention of complications gain foremost importance when timely surgical treatment of a penetrating craniocerebral wound cannot be conducted. Experimental research and clinical experience have shown that the administration of 50 000--100 000 U of an antibiotic (kanamycin, monomycin, hectamycin, chloramphenicol) into the wound soon after an open penetrating injury had been inflicted to the skull and brain protects the wound from microbial contamination. This provides the possibility for postponing the plastic operation of the defect in the dura mater.

Bacterial flora and infection in patients with brain injury

✓ Twenty-five patients with acute head trauma were studied prospectively for appearance of infection during hospitalization in an acute care unit. The study demonstrates: multiple changes in bacterial flora particularly in the respiratory tract, a significant morbidity due to bacterial changes in the respiratory tree, a negligible incidence of bacterial disease due to physiological monitoring procedures, and an inability to correlate changing flora with specific therapeutic or manipulative procedures except tracheostomy. Mortality correlates well with the severity of illness and indirectly with changes in bacterial flora. Despite the frequent isolation of coagulase-positive staphylococci, severity of infectious complications correlate most closely with the acquisition of gram-negative organisms in the respiratory tract.

Retained intracranial bone fragments: analysis of 42 patients

✓ Forty-two patients with retained intracranial bone fragments from Vietnam war wounds were evaluated and treated at the Walter Reed General Hospital. Forty required further debridement, 16 had positive wound cultures while they were on antibiotic therapy, 23 had gross evidence of infection, and the remainder also had debris and necrosis at the retained bone fragment sites. There were eight in-hospital deaths. All surviving patients available to follow-up have been free of infection. Retained intracranial fragments of bone should be removed as early as is possible.