Pathophysiology and Imaging Findings of COVID-19 Infection: An Organ-system Based Review.

BACKGROUND: COVID-19 commonly presents with upper respiratory symptoms; however, studies have shown that SARS-CoV-2 infection affects multiple organ systems. Here, we review the pathophysiology and imaging characteristics of SARS-CoV-2 infection in organ systems throughout the body and explore commonalities. OBJECTIVE: Familiarity with the underlying pathophysiology and imaging characteristics is essential for the radiologist to recognize these findings in patients with COVID-19 infection. Though pulmonary findings are the most prevalent presentation, COVID-19 may have multiple manifestations and recognition of the extrapulmonary manifestations is especially important because of the potential serious and long-term effects of COVID-19 on multiple organ systems.

Collagen-induced morphogenesis and expression of the alpha 2-integrin subunit is inhibited in c-erbB2-transfected human mammary epithelial cells.

The c-erbB2 (or Her2) oncogene is amplified and/or overexpressed in a significant proportion of breast cancers. To assess the role of the c-erbB2 oncogene in mammary tumorigenesis, we have transfected the corresponding human c-erbB2 cDNA into an immortalized human mammary epithelial cell line, MTSV1-7, that was derived from luminal epithelial cells cultured from milk. Three transfectants expressing different levels of the c-erbB2 gene product have been isolated which form colonies in agar and produce tumours in nude mice with high efficiency. We have observed that MTSV1-7 cells form three-dimensional structures in collagen gels and that alpha 2 beta 1-integrin plays a crucial role in the process of morphogenesis. We now find that the c-erbB2 transfectants exhibit an impaired ability to undergo morphogenesis in collagen gels as compared with the parental cell line or the control neomycin transfectant, and that the degree of impairment is related to the level of c-erbB2 expression. Moreover, overexpression of the c-erbB2 product was found to be correlated with a specific decrease in the expression of alpha 2-integrin subunit and in the alpha 2-mRNA. The breast cancer cell line SKBr3, which carries multiple copies of the c-erbB2 gene and overexpresses the 185-kDa product, was also found to express very low levels of the alpha 2-integrin protein and mRNA. Our results confirm the involvement of the alpha 2 beta 1-integrin in collagen-induced morphogenesis of mammary epithelial cells and suggest that the c-erbB2 gene product may inhibit this morphogenesis by inhibiting the expression of the alpha 2-integrin subunit.

Birth injury-induced glossolaryngeal paresis.

Glossolaryngeal paresis followed a difficult delivery and forceps manipulation and was due to a single extracranial traumatic lesion. Although the laryngeal palsy was suspected, hypoglossal involvement was not initially apparent. Search for additional neurologic insult is warranted when a single birth injury is identified. The glossolaryngeal paresis disappeared by age 6 months.

Acute steroid-induced tetraplegia following status asthmaticus.

A 10-year-old girl was treated for an acute asthmatic attack with ventilation and a high-dose steroids regimen. An areflexic paralysis of the four limbs was noted when artificial ventilatory support was withdrawn. Electromyography and a muscle biopsy revealed marked myopathic features. We discuss the unusual presentation of an acute steroid-induced myopathy in an asthmatic patient.

Long-term outcome of children with severe head trauma and prolonged coma.

Forty-six children with significant head trauma who remained in coma more than 24 hours were the subjects of this long-term outcome study. Twelve (38%) died. The average length of coma in the 34 survivors was 15.5 days. Follow-up ranged from 9 months to 4 years (mean 21 months). Twenty-nine percent of the survivors were normal at follow-up. An additional 53% had mild cognitive or behavioral problems, but 61% of these had evidence of similar problems prior to the injury. Nine percent of survivors had motor residua but normal intellect. Nine percent had severe intellectual and motor problems. Children less than 2 years of age had a worse outcome. Despite severe injury and prolonged coma after head trauma, most children do well. Intensive medical and surgical care increases the rate of survival and does not result in a large number of severely disabled survivors.

Toxoplasmosis: a treatable neurologic disease in the immunologically compromised patient.

A 10-year-old girl with aplastic anemia developed seizures and a mild hemiparesis following a bone marrow transplant. Based on serologic evidence and a computed tomography scan, which showed a left parietal lucency with ring enhancement, a diagnosis of toxoplasmosis was considered. A brain biopsy of the lucent area demonstrated the inflammation and necrosis but no organisms were seen. During a six-week course of pyrimethamine, sulfadiazine, and folinic acid therapy there was clinical and neuroradiologic resolution. The short course of therapy as well as the inadvertent substitution of folic acid for folinic acid and trimethoprim-sulfamethoxazole for sulfadiazine resulted in the reappearance of neurologic deficits. Reinstitution of appropriate therapy produced gradual improvement over a nine-month period. Serial computer tomography scans correlated with the clinical course. In the immunologically compromised host CNS toxoplasmosis should be considered in the differential diagnosis of an evolving CNS syndrome. Early detection and prolonged therapy with appropriate drugs can result in a favorable outcome. Computed tomography scanning may be helpful in diagnosis and follow-up.

TaqI polymorphism in the 3' flanking region of the PI gene among Kuwaiti Arabs and Russians.

The Taq1 polymorphism in the 3' flanking region of the PI gene has been reported to be associated with chronic obstructive pulmonary disease (COPD). We have studied the frequency of the Taq1 polymorphism in 117 Kuwaiti Arabs and 110 Russians using PCR/RFLP. The frequency of this polymorphism was found to be 0.235 in the Arabs and 0.027 in the Russians. Such a striking difference in allele frequencies could be due to a 'founder effect' in the Kuwaiti population. However: it may also be that this mutation provides a selective advantage, thus accounting for its fixation at a rather high frequency in some populations. Our results suggest that ethnic composition is a very important factor which should be taken into consideration when studying the association of the Taq1 polymorphism with COPD.

Efficacy of vincristine and cyclophosphamide in the therapy of recurrent medulloblastoma.

We conducted a Phase II study of combination therapy with vincristine and cyclophosphamide in the treatment of patients with recurrent or metastatic medulloblastoma. Fourteen patients were treated with vincristine 2 mg/m2 (2.0-mg maximal dose) by intravenous bolus on Day 1 and cyclophosphamide 1 g/m2 by intravenous infusion on Days 1 and 2, with cycles repeated every 4 weeks. All 4 patients with extraneural disease (biopsy-proven bony metastases) responded (duration of responses 2+, 6+, 8, and 16+ months) and 4 of 8 evaluable patients with neuraxis disease responded (duration of response 2, 2+, 2+, and 21+ months). Toxicity was limited to neutropenia without any episodes of infection. These therapeutic results compare favorably with other reports of therapy for recurrent medulloblastoma and support the inclusion of vincristine and cyclophosphamide in randomized adjuvant therapy trials of patients with medulloblastoma.

Hyperdensity on CT after seizure: a pitfall.

A 12-year-old boy had a hyperdense area corresponding to a gyral pattern on an enhanced CT brain scan within 12 hours of his last seizure. The hyperdense area disappeared on a subsequent enhanced CT scan after he was seizure free for about 48 hours. The hyperdense area was in a location (mesial frontal lobe) predicted by the interictal physical exam findings and the seizure type recorded on video-EEG monitoring. We postulate that the CT abnormality was due to transitory increase of regional cerebral blood flow and vascular permeability.

Status epilepticus.

Status epilepticus represents a true medical emergency that can affect all age groups. Failure to adequately treat this problem can lead to potentially serious systemic and neurologic complications. Management strategies should include stabilization of the cardiovascular and respiratory status of the patient, use of anticonvulsants intravenously and in proper doses, search for a cause, and maintenance therapy.

Extra and central pontine myelinolysis in a child with adrenal insufficiency.

We report a 5-year-old patient with adrenal insufficiency (AI) who had a subacute monophasic neurologic illness and brainstem and striatal lesions on brain imaging. The prominent electrolyte abnormalities in AI indicate that extra and central pontine myelinolysis is the likely cause. An association between AI and extra pontine myelinolysis has not previously been reported in children.

The diagnosis and management of headaches in childhood.

Chronic headaches are relatively common in children and adolescents. The majority of these are benign and do not reflect organic pathology. Diagnosis can usually be made by careful history and physical examination, and extensive laboratory investigations are rarely required. Most children can be managed with reassurance, simple analgesics, and mild sedation. For more severe cases, particularly of migraine, effective pharmacologic agents are available. The prognosis is favorable. Very few of these children go on to develop significant intracranial pathology, and the majority will remit spontaneously. A significant number, however, do have chronic headaches in adult life.

Pediatric radionuclide ventriculography.

Computed tomography is the standard diagnostic examination employed to identify the morbid anatomy of cerebrospinal fluid spaces in children. This noninvasive technique provides excellent anatomic information. However, CT only indirectly characterizes the cerebral spinal fluid pathways. When it is necessary to determine precise bulk cerebrospinal fluid flow for surgical correction, then radionuclide ventriculography (RNV) is a useful adjunctive procedure.

Nuclear anatomy of diversionary central nervous system shunts in children.

A simple method of demonstrating shunt morphology with 99m technetium diethylene triamine penta-acetic acid (99m Tc-DTPA) is described. The anatomic abnormalities are illustrated. Demonstration of the site of obstruction is useful in selecting the neurosurgical approach. The procedure is minimally invasive, accurate, and simple to interpret.

Paranasal sinus aspergillosis.

Nine cases of sinus aspergillosis are presented. The management of the disease is discussed in detail. Emphasis has been placed on the use of intravenous amphotericin B in combination with surgery, in the invasive variety of the disease.

The value of critical incident analysis as an educational tool and its relationship to experiential learning.

Experiential learning and teaching strategies designed to facilitate this, have become popular in nursing and midwifery education in recent years. It is advocated that such learning enables the development of knowledge, skills and attitudes grounded in practice through the use of reflection on action. One strategy that may be utilised by nursing/midwifery educators to develop reflective ability in both themselves and students is critical incident analysis. It is suggested that critical incident analysis has value and is appropriate for developing interpersonal skills and self-awareness. It is proposed that critical incident analysis is a valuable educational tool which enables nursing/midwifery students to draw on past experiences and make sense of them, not only facilitating learning from clinical practice but also going some way towards bridging the gap between theory and practice.

A randomised controlled trial of fluid restriction compared to oesophageal Doppler-guided goal-directed fluid therapy in elective major colorectal surgery within an Enhanced Recovery After Surgery program.

There is continued controversy regarding the benefits of goal-directed fluid therapy, with earlier studies showing marked improvement in morbidity and length-of-stay that have not been replicated more recently. The aim of this study was to compare patient outcomes in elective colorectal surgery patients having goal-directed versus restrictive fluid therapy. Inclusion criteria included suitability for an Enhanced Recovery After Surgery care pathway and patients with an American Society of Anesthesiologists Physical Status score of 1 to 3. Patients were intraoperatively randomised to either restrictive or Doppler-guided goal-directed fluid therapy. The primary outcome was length-of-stay; secondary outcomes included complication rate, change in haemodynamic variables and fluid volumes. Compared to restrictive therapy, goal-directed therapy resulted in a greater volume of intraoperative fluid, 2115 (interquartile range 1350 to 2560) ml versus 1500 (1200 to 2000) ml, P=0.008, and was associated with an increase in Doppler-derived stroke volume index from beginning to end of surgery, 43.7 (16.3) to 54.2 (21.1) ml/m(2), P <0.001, in the latter group. Length-of-stay was similar, 6.5 (5 to 9) versus 6 (4 to 9) days, P=0.421. The number of patients with any complication (minor or major) was similar; 0% (30) versus 52% (26), P=0.42, or major complications, 1 (2%) versus 4 (8%), P=0.36, respectively. The increased perioperative fluid volumes and increased stroke volumes at the end of surgery in patients receiving goal-directed therapy did not translate to a significant difference in length-of-stay and we did not observe a difference in the number of patients experiencing minor or major complications.

Clinical characteristics of gout: a hospital case series.

INTRODUCTION: Gout is an increasingly common medical problem. The traditional risk factors of male sex and high red meat or alcohol consumption have been joined with newer risks such as increased life expectancy, and the metabolic syndrome (hypertension, diabetes, dyslipidaemia, truncal obesity). METHODS: This was a retrospective study to determine the epidemiology, clinical features, associated conditions as well as renal related conditions in existing gout patients followed-up in Rheumatology outpatient clinic, Hospital Tuanku Ja'afar, Seremban. RESULTS: Over a three month period, we identified 54 gouty patients on our follow-up, the majority being male, Malay ethnicity, with the age of onset in the third and fourth decades of life. Commonly associated risk factors were hypertension, hyperlipidaemia and obesity. However, underlying history of diabetes mellitus, alcohol consumption, and family history were not commonly associated with gout in our group of patients. Half of our patients had at least two or more joints involvement. About half of the patients with tophaceous gout had renal impairment. CONCLUSION: Our series of gout patients highlight the high prevalence of cardiovascular risk factors. The high prevalence of tophi and renal impairment is a cause for concern.