Comparison of Pain Control and Analgesic Consumption With or Without Infiltration of Bupivacaine at Port Sites after Laparoscopic Cholecystectomy

Pain management is an essential component of all surgical procedures. Analgesics are used for this purpose but there are some complications in using them. Local anesthetics like bupivacaine can be used to reduce postoperative pain as well as analgesics consumption. The objective of this study is to observe the result of infiltration of bupivacaine at port sites and to compare the postoperative pain relief with that of opioids and NSAID administration following laparoscopic cholecystectomy for chronic calculus cholecystitis. This is a cross sectional study was conducted over one year in the Department of Surgery of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from September 2018 to August 2019. Here total 40 patients were enrolled by purposive sampling. They were divided in two groups. One group received bupivacaine while other did not. A numerical pain scale was used as tool. Data will be recorded by peer reviewed interview and observation based semi structured data collection sheet. Data analysis was done by SPSS version 23.0. P-value was significant at (p<0.05) and determined by chi square test. Written informed consent was taken from the patient. The mean Numerical Rating Scale (NRS) score of pain at 6 hour was 2.55±0.6 in Group I and 6.8±1.15 in Group II. The mean NRS score of pain at 12 hour was 4.1±1.21 in Group I and 7.95±0.6 in Group II. The mean time of 1st analgesic administration was 13.85±1.57 hours in Group I and 2.75±0.72 hours in Group II. The mean repeat dose of analgesic was in 22±2.29 hours in Group I and 9.5±1.15 hours in Group II. In Group I one third patients (30.0%) single dose analgesic required in 1st 12 hours while in Group II almost 90.0% patients needed analgesics in 1st 12 hours. In Group I, total doses of analgesics required were 2 in 75.0% patients while in Group II at least 3 doses of analgesics were needed. In Group I only one patient needed analgesic in first 6 hours (5.0%) while in Group II, all the patients (100.0%) needed analgesics. The difference was statistically significant (p<0.05) between two groups. The patients receiving bupivacaine at port sites will experience less pain at postoperative period and will need less analgesic medications.

Demographic Characteristics of Patients with Breast Cancer in Bangladesh: A Single-Centre Study

We performed this study to investigate the socio-demographic factors of breast cancer patients of Bangladesh. This cross-sectional study was conducted in the Department of General Surgery at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from July 2018 to September 2019 for a period of one (1) year. All consecutive cases of breast carcinoma admitted in hospital and attended at outpatient department during the study period were selected as study population. Total 50 patients were selected. The mean age of the study patients was 51.1. Maximum number (70.0% cases) of breast cancer was belonged in 4th to 5th decade aged group. 70.0% breast cancer patients were housewives. The most of the breast carcinoma was reported in the urban people which were 78.0% cases. The percentage of educated study population was 80.0%. On religious background, 86.0% cases of breast cancer patients were Muslim. Most of breast cancer patients were sporadic in origin 94.0% cases, had no family history of breast cancer. Breast cancer was mostly distributed in pre-menopausal aged group with 82.0% cases. Ninety percent (90.0%) of the study population was come from middle class socio-economic group. In western countries, incidence of breast cancer is more in elderly aged menopause women with high socio-economic class. In this study the breast carcinoma was most prevalent among educated urban Muslim pre-menopausal housewives of age group 4th to 5th decade and most of them belonged to middle socio-economic class. The socio-demographic factors of breast cancer patients in Bangladesh are disparate from western countries in age standard, social class group and menstrual status.

A191 PERSISTENT BENEFIT OF DIETITIAN-LED GLUTEN-FREE DIET EDUCATION AT CD DIAGNOSIS ON DIETARY ADHERENCE IN CHILDREN AND ADULTS WITH TYPE 1 DIABETES AND CELIAC DISEASE

Background

Celiac disease (CD) is a common autoimmune comorbidity of type 1 diabetes (T1D) with a gluten-free diet (GFD) being the current gold standard treatment for this condition. Adherence to a GFD can be impacted by several factors including dietetic counselling, yet little is known about the impact of clinic-based interventions on long-term GFD adherence in this population.

Aims

To prospectively evaluate the impact of a dietitian-led GFD education intervention on adherence to a GFD in children and adults with T1D and CD over a 3-year period.

Methods

A cohort of N=62 pediatric and adult subjects who screened seropositive for CD as part of the CD-DIET clinical trial were followed over a 3-year period post-CD diagnosis and assessed on the basis of the GFD education regimen they received at initial CD diagnosis. This included 3 groups: 1) intensive dietitian training (IDT = 5 dietitian visits over 1 year while following GFD), 2) single dietitian training (SDT = 1 GFD training session after 1 year of following GCD) and 3) no dietitian training (NDT) at CD diagnosis. Annual visits included serologic testing of TTG-IgA titres, anthropometric assessments and the completion of questionnaires evaluating diet and adherence to a GFD. Data was analysed longitudinally using linear mixed effects and generalized estimating equations (GEE) regression modeling adjusting for the fixed effects of age, sex, duration of diabetes and time.

Results

At baseline, participants who received IDT (n=15), SDT (n=16) and NDT (n=31) represented 24.2%, 25.8%, and 50.0% of the cohort, respectively. Over the 3-year study period, participants in the IDT group had the greatest odds of self-reporting being a GFD, with odds 4.3 (95%CI: 1.1 to 16.4; P=0.033) and 9.5 (95%CI: 2.7 to 33.7; P&lt;0.001) greater than the SDT and NDT groups, respectively. The assessment of daily gluten intakes less than 10mg, as recommended for a GFD, revealed a lack of differences between the IDT and SDT groups. In contrast, the NDT group had significantly lower odds of meeting this threshold relative to those who received IDT (OR=0.2; 95%CI: 0.04 to 0.56; P=0.004). No longitudinal differences in TTG-IgA levels were seen between groups over the 3-year period.

Conclusions

In diabetes patients greater contact with a dietitian at CD diagnosis was associated with higher levels of GFD adherence over time, which was not reflected in follow-up Serologic evaluation. These findings highlight the importance of nutritional support in patients with both diabetes and celiac disease at the time of CD diagnosis. In addition, following TTG-IgA alone does not fully inform dietary compliance to a GFD.

Diet teaching stratification

Funding Agencies

Juvenile Diabetes Research Foundation / PSI

1411. Noninvasive Assessment of Intralesional Antimicrobial Concentration-Time Profiles in Pulmonary and Central Nervous System Tuberculosis using Dynamic 18F-Pretomanid Positron Emission Tomography

Background

Pretomanid is used in combination with bedaquiline and linezolid (BPaL regimen) in the treatment of multidrug-resistant tuberculosis (MDR-TB). However, the penetration of pretomanid in privileged sites remain unknown. Antimicrobial pharmacokinetic (PK) parameters are traditionally derived from clinical samples (blood and cerebrospinal fluid), which may not accurately represent the intralesional tissue PK, affected by drug properties, vascular supply, barrier permeability, and the microenvironment.

Methods

We developed 18F-pretomanid (chemically identical to pretomanid) for in vivo multi-compartment PK by positron emission tomography (PET). Dynamic 18F-pretomanid PET was used to obtain cross species pretomanid concentration-time profiles in animal models of TB (mice and rabbits) to quantify penetration into pulmonary and brain lesions. A subset of animals underwent PET/CT imaging with 18F-py-albumin and 18F-FDG to assess vascular supply and inflammation. Postmortem 18F-pretomanid autoradiography (high-resolution) and mass spectrometry were performed in infected tissues. A mouse model of TB meningitis was used to evaluate the bactericidal activity of the BPaL regimen (Figure 1).

Figure 1. Experimental schematics.

Results

18F-Pretomanid PET provided detailed concentration-time profiles in infected tissues demonstrating excellent lung and brain tissue penetration (AUC ratio to plasma &gt; 1) in both animal species, which was spatially compartmentalized, likely due to differential vascular supply (18F-py-albumin PET) (Figure 2). Brain lesions (identified by 18F-FDG PET) demonstrated localized leakiness on 18F-py-albumin PET. Autoradiography and mass spectrometry corroborated the imaging findings. The efficacy of the BPaL regimen in TB meningitis was substantially lower than standard TB treatment (Figure 3), likely due to restricted penetration of bedaquiline and linezolid into the brain parenchyma.

Figure 2. Spatial heterogeneity of 18F-Pretomanid penetration and vascular supply to pulmonary TB lesions.

Conclusion

Dynamic 18F-pretomanid PET provided holistic data on pretomanid exposures showing excellent penetration into infected lung and brain tissues. The BPaL regimen was inferior to standard TB treatment for TB meningitis. Thus, new pretomanid-containing regimens need to be developed for the treatment of MDR-TB meningitis.

Disclosures

Charles A. Peloquin, Pharm.D., Nothing to disclose Alvaro A. Ordonez, MD, Cubresa (Consultant)Fujirebio Diagnostics (Research Grant or Support) Sanjay K. Jain, MD, Fujirebio Diagnostics, Inc., USA (Research Grant or Support)Novobiotic LLC, USA (Research Grant or Support)T3 Pharma, Switzerland (Research Grant or Support) Sanjay K. Jain, MD, Fujirebio Diagnostics, Inc., USA (Individual(s) Involved: Self): Research Grant or Support; Novobiotic LLC, USA (Individual(s) Involved: Self): Research Grant or Support; T3 Pharma, Switzerland (Individual(s) Involved: Self): Research Grant or Support

191. High-Dose Rifampin-containing Regimens for the Treatment of TB Meningitis

Background

TB meningitis is the most severe form of tuberculosis (TB), associated with high morbidity and mortality. High-dose rifampin (35mg/kg/day) is safe in adults and substantially improves the bactericidal activity of standard TB regimen. However, there is conflicting data regarding its benefit in TB meningitis where outcomes may also be associated with intracerebral inflammatory responses.

Methods

A novel mouse and a validated rabbit model of TB meningitis utilizing intracranial Mycobacterium tuberculosis infections were used for these studies (Fig. 1). Animals received high-dose (35 mg/kg/day) or standard-dose (10 mg/kg/day) rifampin in combination with isoniazid, pyrazinamide and dexamethasone at human equipotent dosing. Bacterial burden, multi-modality positron emission tomography (PET) imaging, tissue drug concentrations, markers of neuroinflammation, and vascular leak were measured. Imaging data from a patient with TB meningitis was analyzed and correlated with the findings in animals.

Results

Administration of the high-dose rifampin regimen achieved four times higher brain concentration than the standard-dose regimen and displayed higher bactericidal activity in both mice and rabbits (P &lt; 0.01) (Fig. 2). There were no differences in intracerebral microglial activation (124I-DPA-713 PET and iDISCO) and pro-inflammatory cytokines during treatment in animals receiving high- or standard-dose rifampin regimens (Fig. 3). Whole-brain PET and immunolabeling demonstrated spatially compartmentalized inflammation, vascular leak and rifampin exposures (Fig. 4). Longitudinal imaging in the same animals showed a 40% decrease in vascular leak after two weeks of TB treatment. Spatially compartmentalized brain rifampin exposures and decreases in vascular edema over TB treatment were also noted in the TB meningitis patient.

Conclusion

Our cross-species findings suggest that an intensified high-dose rifampin regimen is more efficacious than the standard treatment for TB meningitis without an increase in neuroinflammation. Vascular leak decreases during TB treatment and may account for decreases in rifampin permeability over time. These studies have important implications for antimicrobial development for TB meningitis.

Disclosures

Charles A. Peloquin, Pharm.D., Nothing to disclose Alvaro A. Ordonez, MD, Cubresa (Consultant)Fujirebio Diagnostics (Research Grant or Support) Sanjay K. Jain, MD, Fujirebio Diagnostics, Inc., USA (Research Grant or Support)Novobiotic LLC, USA (Research Grant or Support)T3 Pharma, Switzerland (Research Grant or Support) Sanjay K. Jain, MD, Fujirebio Diagnostics, Inc., USA (Individual(s) Involved: Self): Research Grant or Support; Novobiotic LLC, USA (Individual(s) Involved: Self): Research Grant or Support; T3 Pharma, Switzerland (Individual(s) Involved: Self): Research Grant or Support

A Prospective Study of Deep Vein Thrombosis after Major Abdominal Surgery in a Tertiary Level Hospital

This prospective study was conducted to find the rate of deep and risk factors associated with vein thrombosis following major abdominal surgery in Sylhet MAG Osmani Medical College Hospital from 1st November 2017 to 30th April 2018. Total 103 patients aged above 20 years both male and female who got admitted in Department of Surgery, Sylhet MAG Osmani Medical College Hospital, Sylhet for their disease requiring routine and emergency major abdominal operation during the study period and fulfilling the inclusion and exclusion criteria were selected in this study. Informed written consent was obtained from the patients after full explanation of the purpose of the study. After full investigations and proper preparation of each patient for operative procedure major abdominal surgery were done. Peroperative findings were noted and post-operative period were followed up routinely. Duplex scanning was done on 3rd POD in all cases. The age of the patients ranged from 25 to 74 years with the mean age of 49.5±13.8 years. There were 60(58.3%) male and 43(41.7%) female. Deep vein thrombosis (DVT) developed in 5(4.9%) of cases and not developed in 98(95.1%) cases. All the five cases were confirmed by color duplex scan. DVT was detected in 2(3.3%) of the 60 males and 3(7.0%) of the 43 females undergoing major general surgical procedures. Among 63 patients in whom the duration of surgery was up to 2 hours, none developed DVT, while among the 40 patients in whom the duration of surgery lasted more than 2 hours, 5(12.5%) developed DVT. Among 23 patients in whom the surgery for malignancy was done, 4(17.4%) developed DVT, while among the 80 patients in whom surgery for non-malignancy, 1(1.2%) developed DVT. The Incidence of DVT in patients undergoing major abdominal surgery is 4.9%. Patients undergoing major abdominal surgery for malignancy and duration of operation greater than 2 hours have higher risk of developing DVT. But there is no significant increase in risk of development of DVT relation to age and sex; and also in patients on oral contraceptives, diabetes mellitus, obesity and smoking. Clinical findings alone cannot be relied upon for the diagnosis of DVT. The study has to be continued with larger sample size to get statistically significant results.

Plasmodium falciparum protein kinase as a potential therapeutic target for antimalarial drugs development

Malaria is one of the most dangerous infectious diseases due to its high infection and mortality rates, especially in the tropical belt. Plasmodium falciparum (P. falciparum), the most virulent malaria parasite in humans, was recently reported to develop resistance against the final efficient antimalarial drug, artemisinin. Little is known about the resistance mechanisms, which further complicates the problem as a proper counteraction is unable to be taken. Hence, the understanding of drug mode of action and its molecular target is valuable knowledge that needs to be considered to develop the next generation of antimalarial drugs. P. falciparum protein kinase (Pf PK) is an attractive target for antimalarial chemotherapy due to its vital roles in all P. falciparum life stages. Moreover, overall structural differences and the presence of unique Pf PKs that are absent in human kinome, suggesting specific inhibition of Pf PK without affecting human cells is achievable. To date, at least 86 eukaryotic protein kinases have been identified in P. falciparum kinome, by which less than 40 were validated as potential targets at the erythrocytes stage. In this review, recent progress of the furthest validated Pf PKs; Pf Nek-1, Pf CDPK1, Pf CDPK4, Pf PKG, and Pf CLK-3 will be briefly discussed.

Hand Sewn versus Stapled Closure of Duodenal Stump after Gastric Resection

This prospective comparative study was done to compare the outcome of stapled closure of the duodenal stump with hand-sewn closure during gastric resection in terms of total operating time, postoperative duodenal stump leakage, postoperative hospital stay, and surgical cost. This study was conducted from January 2013 to August 2014. Patients who were admitted to the Department of Surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh with the indication of distal or total gastrectomy were included in the study. A total of 32 patients were enrolled in this study with 16 in each group, they were divided either into Group I (Hand Sewn) or Group II (stapling). Mean±SD age of Group I was 53.38±8.69 and Group II was 50.88±9.56 (p=0.445). Male patients were predominant than the female with a male: female ratio being 3.57:1. Mean±SD total operating time was 154.38±16.32 minutes and 136.88±17.40 minutes in Group I and Group II respectively (p=0.001). In Group I, 2(12.5%) patients and in Group II, 1(6.3%) patient had duodenal stump leakage which showed no statistically significant difference (p=0.999). Postoperative hospital stay had no statistically significant difference (p=0.923). The surgical cost had a significant difference (p=0.001) which is more in Group II. This study showed there was a significant reduction in total operating time but there was no significant difference in occurring of duodenal stump leakage or postoperative hospital stay. However, use of stapler hastens the surgeon's job and it relieves extra pressure of them.

Cytologically Indeterminate Follicular Thyroid Nodule on Fine Needle Aspiration Cytology is an Indication for Total Thyroidectomy

The magnitude of case management of indeterminate thyroid nodule is very difficult and controversial. In addition there is recent evidence that the incidence of follicular lesion may be increasing that will prove to be follicular cancer. This prospective observational study was done in the department of Surgery at Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from February 2016 to January 2017 to investigates the rate of malignancy and inability of demographical, clinical and sonographic data to predict malignancy in indeterminate nodules and the unreliability of intraoperative frozen section biopsy with the scope of determining the need for total thyroidectomy in these patients. The study population consisted of 40 cases presenting indeterminate nodules (Thy3): females (80%) and males (20%) with a mean age of 35.73±11.11 years. All patients underwent total thyroidectomy. Malignancy was diagnosed in 27 out of 40 patients (67.5%). The mean nodule size was 3.67±1.69mm in malignant lesions, 40.7% of the malignant nodules were more than 3cm in size, 51.9% of malignant cases were irregular border and 29.6% of malignant lesions were hard in consistency; these data are statistically significant (<0.05) and correlated with malignancy. The rate of malignancy in cytologically indeterminate lesions was high in the present study sample compared to other reported studies. Thus, considering the fact that demographical, clinical and sonographic features were found to be inaccurate predictors of malignancy, it is our opinion that total thyroidectomy should always be recommend in such patients.

Impaired endothelial function in Hodgkin lymphoma survivors receiving mediastinal radiation

e19526

Background: Mediastinal radiation (RT) is a cause of premature coronary artery disease (CAD) in Hodgkin lymphoma survivors (HLS). Early detection of atherosclerosis may allow for improved health outcomes. Peripheral arterial tonometry (PAT) is a non-invasive technique that measures endothelial function (EF), as a surrogate marker of sub-clinical atherosclerosis. The objective of our study was to evaluate EF in HLS and age-matched controls using PAT and to determine the association of mediastinal RT. Methods: Cross sectional evaluation of 26 HLS age 12–30 years and within a minimum of two years from the completion of therapy and matched controls. Evaluation for CAD risk factors included measurement of body mass index and blood pressure, fasting lipoproteins and hsCRP. A standardized activity questionnaire (HAES, habitual activity estimation score) was completed by all participants. EF was measured using PAT hyperemia ratios (PAT-HR) in all subjects. Results: HLS and controls were similar for baseline variables (mean age 23.2 ± 5 yrs; 23.4 ± 4.6 yrs, p=0.35). HLS were on average 9.9 ± 3.9 yrs post treatment. No differences in EF or cardiovascular risk factors were observed between HLS survivors and controls. However impaired EF, as evidenced by lower PAT-HR (1.66 ± 0.18 vs. 2.08 ± 0.38, p<0.01) was seen in HLS (n=13) who received mantle/mediastinal RT (mean RT dose 2657 ± 971 cGy) compared to controls. Mean cumulative anthracycline dose did not differ between HLS who did or did not receive RT (224.1 ± 65.4 vs. 253 ± 70.3 mg/m2 p=0.18). These differences were not explained by alterations in lipoproteins or hsCRP, however activity scores were significantly lower in HLS compared with young adult controls (2.01 ± 1.1 vs. 3.6 ± 1.2 hrs daily, p=0.02). Conclusions: Impaired EF was observed in a small group of HLS who received mediastinal RT as compared to those who did not. Cancer survivors at risk may benefit from early assessment of EF as a sub-clinical marker of CAD.

No significant financial relationships to disclose.

Intraoperative pacemaker dysfunction caused by the use of electrocautery during a total hip arthroplasty

Pacemaker dysfunction encountered during orthopedic procedures is a rare but potentially life-threatening complication. With an increasing number of orthopedic procedures performed on the aging population, it is not uncommon to encounter patients with pacemakers requiring major orthopedic intervention. Most, if not all, major orthopedic procedures performed today require the use of electrocautery for hemostasis. In this article we review the literature for pacemaker complications and report a case of pacemaker failure after a single use of the unipolar electrocautery on a patient undergoing a total hip replacement.

Effects of spinal instrumentation on fusion of the lumbosacral spine

STUDY DESIGN

This study retrospectively, reviewed the effects of pedicle screw fixation on lumbosacral fusion for degenerative conditions. The records and radiographs of a group of patients treated by wide decompression and fusion of the lumbosacral spine and by one surgeon were studied. Two treatment groups were identified by fusion technique; one group received autologous bone graft only, and second group was treated by autologous bone grafting supplemented with pedicle screw fixation.

OBJECTIVES

The two study groups were compared to determine the effects of pedicle screw fixation on lumbosacral fusion for degenerative conditions after wide decompression.

SUMMARY OF BACKGROUND DATA

The reported success rate of lumbar and lumbosacral fusion in the literature is variable. Although several studies have reported high fusion rates with internal fixation, few controlled studies have been published. A critical review of isolated lumbosacral fusions (for degenerative conditions) and the effects of instrumentation is necessary to determine the effectiveness and complications associated with pedicle screw systems in this setting.

METHODS

This study reviewed 215 consecutive patients operated on from 1987 to 1992 for degenerative conditions of the lumbosacral spine. Group 1 included 126 patients who underwent autogenous posterolateral bone graft after decompression. Group 2 included 89 patients treated with Edwards instrumentation and autogenous bone graft. Fusion status was determined via radiographs. Clinical results were based on pain relief after a minimum 2-year follow-up period.

RESULTS

In Group 1, an overall fusion rate of 65% was obtained. Clinically, 56% had good or excellent results. Complications included pseudarthroses (35%), dural tears (3.2%), and infection (2.4%). In Group 2, a fusion rate of 91% was achieved. In this group, 89% had a good or excellent clinical result. Complications included pseudarthroses (9%), dural tears (2.2%), and infection (2.2%).

CONCLUSIONS

Use of pedicle screw and rod fixation with the Edwards system led to significantly improved results in lumbosacral fusions over autogenous bone graft alone, with a lower complication rate. The use of spinal is a valuable adjunct to achieve lumbosacral fusion in patients who have undergone decompressive surgery for the spine.

Reversible cystic dilatation of distal airways due to foreign body

We describe a child with foreign body aspiration whose chest radiograph showed an unusual appearance of multiple round lucencies simulating bronchiectasis. This appearance is contrary to the usual appearance of emphysema due to the check-valve type of obstruction. This report is particularly useful for pediatricians and family physicians, who should be aware of the variable appearances of foreign body aspiration. Our case emphasizes the necessity of early bronchoscopy in pediatric patients with unresolving pneumonia.

Modulation of transmission gain by protons at the photoreceptor output synapse

Synaptic transmission of the light response from photoreceptors to second-order cells of the retina was studied with the whole-cell patch-clamp technique in tiger salamander (Ambystoma tigrinum) retinal slices. Synaptic strength is modulated by extracellular pH in a striking manner: Light-sensitive postsynaptic currents in horizontal and bipolar cells were found to be exponential functions of pH, exhibiting an e-fold increase per 0.23 pH unit over the pH range from 7 to 8. Calcium channel currents in isolated photoreceptors were measured and also exhibited proton sensitivity. External alkalinization from pH 7 to 8 shifted the voltage dependence of channel activation negative by 12 mV. A model of the synaptic transfer function suggested that presynaptic Ca channels could be the primary sites of proton action. Increased Ca influx and transmitter release brought about by alkalinization give rise to larger postsynaptic currents. These results suggest that activity-dependent interstitial pH changes known to occur in the retina, while not alleviating signal clipping at this synapse, may provide an adaptative mechanism controlling gain at the photoreceptor output synapse.

The in vivo effects of naproxen on canine experimental osteoarthritic articular cartilage: composition, metalloproteinase activities and metabolism

A canine experimental model of osteoarthritis (OA), generated by arthroscopic transection of the anterior cruciate ligament (ACL) of the knee, was used to investigate the in vivo effects of the NSAID naproxen on the course of cartilage degeneration. The drug was given at the time of surgery, or from before surgery, and for 16 weeks after surgery. Analysis of the articular cartilage showed the naproxen was able to significantly suppress the decrease in proteoglycan content and metalloproteinase activities. The results indicate that pharmaceutical agents have the potential to modulate the progression of degenerative joint disease.

Congenital central nervous system anomalies

Magnetic resonance imaging, because of its multiplanar capabilities and exquisite contrast differentiation, has risen above all other forms of in vivo imaging for the classification and determination of congenital central nervous system (CNS) anomalies. We briefly discuss pertinent aspects of CNS embryology and, using a recently proposed classification of central nervous system anomalies, present examples of a spectrum of abnormalities that one may encounter in practice. These anomalies include: the Chiari malformations, encephaloceles, holoprosencephaly, septooptic dysplasia, Dandy-Walker variant, hydranencephaly, phakomatoses, schizencephaly, agyria or pachygyria, and dysgenesis of the corpus callosum.

Air embolism from mechanical ventilation in respiratory distress syndrome

Three cases of air embolism secondary to mechanical ventilation in premature infants with respiratory distress syndrome are presented, and its mechanism is discussed. A plausible mechanism for air in the hepatic veins occurring in most of these cases is also discussed. Many sudden unexplained deaths in premature infants on mechanical ventilation may be due to air embolism, which should be recognized as a component of neonatal "air-block syndrome."