[Swyer-James syndrome with unilateral pulmonary edema]

A 64-year-old man with ischemic heart disease was admitted to our hospital because of dyspnea. A chest X-ray film showed a butterfly shadow in the right lung. A chest X-ray film obtained before the patient had respiratory symptoms showed hyperlucency of the left lung. CT scans obtained at maximal inspiration and expiration revealed air trapping. Pulmonary arteriography showed that the left pulmonary artery and its branches were very small. Cardiac catheterization showed poor cardiac function. Swyer-James syndrome should be included in the differential diagnosis of patients with unilateral pulmonary edema.

A- and C-reflexes elicited in cardiac sympathetic nerves by single shock to a somatic afferent nerve include spinal and supraspinal components in anesthetized rats

The spinal and supraspinal components of both A- and C-reflexes were studied in the somato-cardiac sympathetic reflex discharges elicited by a single electrical shock either to a spinal (T3-4) afferent nerve or to a limb (tibial) afferent nerve in urethane anesthetized rats. In central nervous system (CNS) intact rats, a single shock to a T3-4 spinal afferent nerve produced early and late A-reflex discharges with latencies of 20 +/- 1 ms and 62 +/- 6 ms, respectively, and a C-reflex with a latency of 136 +/- 9 ms in a cardiac sympathetic efferent nerve. After spinalization at the first cervical level, stimulation of the same spinal afferent nerve produced an A-reflex with the same latency as the early A-reflex in CNS-intact rats and a C-reflex with a latency of 86 +/- 3 ms. The amplitude of the early A-reflex became augmented after spinal transection. On the other hand, a single shock to a tibial afferent nerve evoked an A-reflex discharge with a latency of 41 +/- 2 ms and a C-reflex discharge with a latency of 210 +/- 13 ms in CNS-intact rats. These A- and C-reflexes elicited by stimulation of a tibial afferent nerve were not observed after spinalization. It was concluded that cardiac sympathetic A- and C-reflex discharges evoked by stimulation of a segmental spinal afferent nerve in CNS-intact rats are of spinal and supraspinal origin, and those evoked by tibial nerve stimulation are of supraspinal origin. The spinal reflex pathway is segmentally organized, because the spinal reflex is evoked only when stimulation is delivered to afferent nerves close to the cardiac sympathetic outflow segments. With the CNS intact, the spinal reflex component is depressed by descending inhibitory pathways originating in the brain.

Parathyroid carcinoma with metastatic calcification identified by technetium-99m methylene diphosphonate scintigraphy

We describe herein a case of parathyroid carcinoma accompanied with metastatic calcification identified by technetium-99m methylene diphosphonate (Tc-99m MDP) scintigraphy in the lungs, kidneys and stomach. Parathyroid carcinoma remains a rare disorder despite the increased prevalence of primary hyperparathyroidism. Metastatic calcification is noted infrequently even in primary hyperparathyroidism and it may cause respiratory failure. Tc-99m MDP scintigraphy three months after surgery showed a complete disappearance of Tc-99m uptake in the stomach and an obvious reduction in the kidneys but no significant change in the lungs, indicating metastatic calcification can be reversibly reabsorbed. This case indicates that the adequate excision of parathyroid carcinoma as well as the early detection of metastatic calcification by Tc-99m MDP are obligatory.

Possible involvement of an environmental agent in the development of acute eosinophilic pneumonia

BACKGROUND

Although the pathogenesis of acute eosinophilic pneumonia remains largely unknown, it has been suggested that it may include a hypersensitivity phenomenon induced by inhaled environmental antigens.

METHODS

To investigate this possibility, we studied the effect of environmental challenges in three patients with acute eosinophilic pneumonia. Symptoms and laboratory findings were evaluated before and after the challenge tests in the patient's homes and their places of work.

RESULTS

After the provocation challenges to their homes, all three patients developed fever, cough, and fatigue and two of them presented with dyspnea. Inspiratory crackles became audible in all cases, and there was a decreased Pao2 level in two. Similar challenges at their workplaces were negative. After moving out of their homes, the patients engaged in their usual work but had no recurrent episodes.

CONCLUSIONS

These results suggest that environmental factors in the home can be the cause of acute eosinophilic pneumonia. In order to elucidate the pathogenesis of the disease, it is important to further investigate environmental factors.

Biochemical evidence for the interaction of regulatory subunit of cAMP-dependent protein kinase with IDA (Inter-DFG-APE) region of catalytic subunit

To explore the structural basis required for the holoenzyme formation of cAMP-dependent protein kinase, we have prepared rabbit anti-peptide antibodies that can block the holoenzyme formation without affecting the catalytic activity of the enzyme. The antibodies were raised against a specific site in the catalytic (C)-subunit, termed IDA (Inter-DFG-APE) region, which lies between the kinase subdomains VII and VIII. Although the C-subunit immunoprecipitated with anti-IDA antibodies could not form a stable complex with regulatory (R)-subunit, it was still susceptible to inhibition by the R-subunit or by PKI, a specific inhibitor peptide containing a pseudosubstrate site. These results indicate that there exists an IDA region-mediated interaction between the R- and C-subunits, which is distinct from that mediated through the substrate site and substrate binding site. In accordance with this idea, association of synthetic IDA peptides with the R-subunit was directly demonstrated by resonance mirror analysis. The calculated association constants of IDA peptides were high enough to suggest a possible involvement of the IDA region in the initial step of holoenzyme formation.

Projection from the accommodation-related area in the superior colliculus of the cat

Our previous study has indicated that accommodative responses can be evoked with weak currents applied to a circumscribed area of the superior colliculus in the cat. We investigated efferent projections from this area with biocytin in the present study. The accommodation area in the superior colliculus was identified by systematic microstimulation in each of five anesthetized cats. Accommodative responses were detected by an infrared optometer. After mapping the superior colliculus, biocytin was injected through a glass micropipette into the accommodation area, where accommodative responses were elicited with low-intensity microstimulation. In addition, accommodative responses to stimulation of the superior colliculus were compared before and after an injection of muscimol, an agonist of inhibitory neurotransmitter, into the pretectum. Following the injection of biocytin, in the ascending projections, labeled terminals were seen mainly in the caudal portion of the nucleus of the optic tract, the nucleus of the posterior commissure, the posterior pretectal nucleus, the olivary pretectal nucleus, the mesencephalic reticular formation at the level of the oculomotor nucleus, and the lateral posterior nucleus of the thalamus on the ipsilateral side. Less dense terminals were seen in the anterior pretectal nucleus, the zona incerta, and the centromedian nucleus of the thalamus. In the descending projections, labeled terminals were observed mainly in the paramedian pontine reticular formation, the nucleus raphe interpositus, and the dorsomedial portion of the nucleus reticularis tegmenti pontis on the contralateral side. Less dense terminals were also seen in the nucleus of the brachium of the inferior colliculus, the cuneiform nucleus, the medial part of the paralemniscal tegmental field, and the dorsolateral division of the pontine nuclei on the ipsilateral side. Following the injection of muscimol into the pretectum, including the nucleus of the optic tract, the posterior pretectal nucleus, and the nucleus of the posterior commissure, accommodative responses evoked by microstimulation of the superior colliculus were reduced to 33-55% of the value before the injections. These findings suggest that the accommodation area in the superior colliculus projects to the oculomotor nucleus through the ipsilateral pretectal area, especially the nucleus of the optic tract, the nucleus of posterior commissure, and the posterior pretectal nucleus, and also projects to the pupilloconstriction area (the olivary pretectal nucleus), the vergence-related area (the mesencephalic reticular formation), and the active visual fixation-related area (the nucleus raphe interpositus).

Varicella pneumonia in a healthy adult presenting with severe respiratory failure

We describe a case of varicella pneumonia in a 24-year-old healthy man presenting with severe respiratory failure. A chest radiograph showed diffuse, bilateral airspace consolidation; additional complications included liver dysfunction and thrombocytopenia. However, treatment with intravenous acyclovir and gamma-globulin improved his clinical symptoms and signs. A greater than four-fold change in paired titers of the varicella-zoster virus antibody was observed. Bronchoalveolar lavage performed during the recovery phase revealed increased total cell and lymphocyte counts and a decreased CD4:CD8 ratio of T lymphocytes. Transbronchial lung biopsy findings were compatible with a diagnosis of interstitial pneumonia.

Interleukin-1 beta decreases sensitivity of guinea-pig airway to potassium chloride and isoproterenol by an epithelium-dependent mechanism

Airway inflammation may cause alteration of airway responses in chronic airway diseases, such as bronchial asthma. The objective of this study was to examine whether interleukin-1beta (IL-1beta) [corrected], one of the pro-inflammatory cytokines, has a direct effect on airway functions. The effects of IL-1beta on carbachol, KCl and isoproterenol (ISO) responses of isolated guinea-pig tracheal strips were examined by measuring isometric tension in tissue bath. Responses of tracheal strips with or without epithelium to each agonist were compared before and after incubation with IL-1beta (25 ng or 250 ng/mL). Both 1 h and 5 h incubation of the strips with 250 ng/mL IL-1beta significantly decreased the sensitivity not only to KCl (P < 0.05; P < 0.01, respectively), but also to ISO (both P < 0.05) without affecting maximum contraction or relaxation. Response to carbachol was not affected by IL-1beta. Epithelial denudation abolished the effects of IL-1beta on KCl and ISO responses. Indomethacin (2 micromol/L) [corrected] reversed the effects of IL-1beta both on KCl and on ISO. These results suggest that IL-1 beta decreases the sensitivity of airway strips to KCl and ISO, possibly by stimulating prostaglandin production from the airway epithelium [corrected].

Ischemic injury of the small intestine studied by 31P-MRS

In order to examine the efficacy of phosphorus-31 nuclear magnetic resonance spectroscopy (31P-MRS) of the small intestine during superior mesenteric artery occlusion (SMAO) and reperfusion, we compared the beta-ATP level measured by in vivo 31P-MRS and the ATP level measured by high performance liquid chromatography (HPLC) in a rat model. The rat small intestines were subjected to 30 or 90 min of SMAO followed by reperfusion. 31P-nuclear magnetic resonance spectra were taken every 10 min during SMAO and subsequent reperfusion. Specimens for HPLC were taken every 30 min. Metabolite levels measured by 31P-MRS and HPLC demonstrated a linear correlation. This result shows that 31P-MRS can determine the ATP content of the small intestine as well as HPLC. Additionally, the changes of beta-ATP, inorganic phosphate (Pi) and tissue pH in the small intestine during SMAO and reperfusion were examined by 31P-MRS in detail. beta-ATP decreased with longer SMAO times, and the recovery rate of beta-ATP after reperfusion also decreased with longer SMAO times. Therefore, the ATP level measured by 31P-MRS may provide a clinical parameter of tissue damage and organ viability. The levels of Pi and tissue pH changed greatly, but reached a plateau in the early phase of SMAO. Their levels after reperfusion reflected the time of SMAO, and therefore may also provide a clinical parameter of organ viability.

A clinical study of minocycline-induced pneumonitis

We studied the clinical features of minocycline-induced pneumonitis in seven patients. Acute symptoms included fever, dry cough and dyspnea, indicating acute respiratory failure. Diffuse ground glass shadows with Kerley's B lines, bronchial wall thickening, swelling of vascular bundles and pleural effusion were visible on radiography. Bronchoalveolar lavage or transbronchial lung biopsy confirmed pulmonary eosinophilia. Cessation of minocycline led to rapid remission with no treatment or only short-term steroid therapy. The lymphocyte stimulation test for minocycline with peripheral blood lymphocytes was not found to be useful for diagnosis.

[Asthma-like symptoms due to thoracic aneurysm]

We describe a case of positional dyspnea due to compression of the tracheobronchial tree by an extensive thoracic aneurysm. In a 77-year-old woman with long-standing systemic hypertension, intermittent anterior chest pain gradually developed over several years. She had no history of asthma or thoracic trauma. She was admitted to our hospital because of sudden, severe shortness of breath. The breathlessness was markedly worse when she lay on her back or on her right side. On physical examination, she was in acute respiratory distress with cyanosis, severe hypertension (180/110 mmHg), tachycardia, and inspiratory stridor. A chest X-ray film showed loss of volume and nearly complete radiopacity of the left hemithorax. Arterial blood gas analysis revealed an arterial oxygen partial pressure of 54.8 mmHg, a carbon dioxide partial pressure of 39.8 mmHg, and an oxygen saturation of 84.5 percent on room air. Computed tomographic examination of the thorax showed dilation of the aortic arch and descending aorta, and marked compression of the trachea and the left main bronchus. Examination with a fiberoptic bronchoscope revealed extrinsic compression of the trachea just proximal to the carina. The patient's symptoms stabilized. However, she did not undergo surgery because of her age and because of the size of the aneurysm. She died due to rupture of the aneurysm.

Stimulation of saphenous afferent nerve produces vasodilatation of the vasa nervorum via an axon reflex-like mechanism in the sciatic nerve of anesthetized rats

The present study was intended to examine the physiological relevance of peptidergic afferent vasodilative fibers in the regulation of blood flow in the vasa nervorum, with special reference to the axon reflex. The response of nerve blood flow (NBF) in the sciatic nerve to electrical stimulation of saphenous nerve afferents was examined using laser Doppler flowmetry in anesthetized rats whose lumbosacral afferents and efferents had been disconnected from the spinal cord. Repetitive electrical stimulation of unmyelinated fibers in the central cut end of the saphenous nerve produced an increase in NBF in the sciatic nerve ipsilateral to the stimulation, independent of changes in mean arterial blood pressure. This increase was abolished by topical application of a calcitonin gene-related peptide (CGRP) receptor antagonist, hCGRP (8-37). In conclusion, NBF in the sciatic nerve is regulated via an axon reflex-like mechanism by unmyelinated afferent CGRP containing vasodilators with collaterals in the saphenous nerve.

Dissociation between serum interleukin-6 rise and other parameters of disease activity in subacute thyroiditis during treatment with corticosteroid

Increased serum interleukin-6 (IL-6) concentrations have recently been reported in patients with subacute thyroiditis, possibly because of cytokine release from damaged thyroid cells. To investigate the changes in serum IL-6 concentrations in subacute thyroiditis during treatment with corticosteroid, serum IL-6 concentrations were determined by an enzyme-linked immunosorbent assay method in five patients with subacute thyroiditis. Serum IL-6 concentrations were increased moderately, and simultaneously, serum levels of T4, thyroglobulin, and C-reactive protein and erythrocyte sedimentation rate were increased markedly. The treatment with prednisolone rapidly and progressively decreased serum levels of thyroglobulin, T4, and C-reactive protein and the erythrocyte sedimentation rate. In contrast, serum IL-6 concentrations increased markedly 7 days after the treatment with prednisolone in all five patients and two of five patients showed further increases in serum IL-6 concentration on the 17th day. The rise in serum IL-6 levels in untreated patients with subacute thyroiditis in this study is compatible with previous reports. The rise in serum IL-6 levels after treatment with corticosteroid in subacute thyroiditis may reflect the dissociation between the persistent release of IL-6 from the damaged thyroid cells, immediate inhibition of secondary inflammatory reactions by corticosteroid, and the release of thyroglobulin and T4 from performed colloid stores in follicular lumen destroyed by subacute thyroiditis.

Mechanisms of epidermal growth factor-induced contraction of guinea pig airways

We investigated the functional effects of epidermal growth factor (EGF) on guinea pig airways in vitro. EGF (3 ng/ml to 1 microgram/ml) induced a concentration-dependent contraction in epithelium-denuded strips. The average maximal contraction was 0.64 +/- 0.1 g (mean +/- S.E., for n = 27), which was 72.0 +/- 9.5% of the 100 mM KCl-induced contraction. The EC50 was 12.3 +/- 1.6 ng/ml. The presence of the epithelium significantly suppressed the EGF-induced contraction (P < 0.01). EGF-induced contraction was abolished by cyclooxygenase inhibitors (indomethacin and ibuprofen) and a 5-lipoxygenase inhibitor, 2-(12-hydroxydodeca-5,10-diynyl)-3,5,6-trimethyl-1,4-benz oqu inone (AA-861). It was also inhibited by a leukotriene-receptor antagonist, 8-[p-(4-phenylbutyloxy)benzoyl]amino-2-(tetrazol-5-yl)-4-oxo -4H-1-benzopyran hemihydrate (ONO-1078) but not affected by a thromboxane A2-synthetase inhibitor, (E)-3-[4-(1-imidazolylmethyl)phenyl]-2-propenoic acid (OKY-046) or a thromboxane A2-receptor antagonist, 9,11-epithio-11,12-methano-thromboxane A2 (ONO-3708). A phospholipase A2 inhibitor (mepacrine) inhibited the EGF-induced contraction but a diacylglycerol-lipase inhibitor, 1,6-di-(O-(carbamoyl)cyclohexanone oxime)hexane (U-57908) and a phospholipase D inhibitor (wortmannin) did not affect it. A tyrosine kinase inhibitor (genistein) abolished it. Measurement of prostanoids showed that EGF (300 ng/ml) did not increase the prostaglandin F2 alpha level in either epithelium-intact or epithelium-denuded strips. In epithelium-intact strips, EGF significantly increased the prostaglandin E2 concentration (P < 0.01). These results suggest that EGF causes contraction of guinea pig airway smooth muscle by activating tyrosine kinase followed by phospholipase A2 activation, and that arachidonic acid metabolites, especially leukotrienes, may have important roles in this contraction.

Characterization of mouse leukemia L1210 cells resistant to the ribonucleotide reductase inhibitor 4-methyl-5-amino-1-formylisoquinoline thiosemicarbazone

Mouse leukemia L1210 cells were generated for resistance to 4-methyl-5-amino-1-formylisoquinoline thiosemicarbazone (MAIQ), a potent inhibitor of ribonucleotide reductase that is directed in the nonheme iron subunit (NHI) of the enzyme. The resistant cells, MQ-580, showed an 8-fold increase in IC50 toward MAIQ, a 4-fold increase in IC50 toward hydroxyurea, and also showed resistance to other ribonucleotide reductase inhibitors. In addition, the MQ-580 cell line was resistant to nonribonucleotide reductase inhibitors such as etoposide, daunomycin and vinblastine, but not to cisplatin. The mRNA for the NHI subunit was increased 7-fold in the MQ-580 cells with essentially no change in the mRNA level for the effector-binding subunit. The ribonucleotide reductase activity in the cell-free extracts prepared from the MQ-580 cells was only slightly elevated (30%). However, passage of the cell-free extract from the MQ-580 cells over Sephadex G-25 resulted in a 4.8-fold increase in specific activity over that of the wild-type cells. While the reductase activity in the cell-free extract from the MQ-580 cells did not show altered sensitivity to MAIQ, the reductase activity in the cell-free extract from the MQ-580 cells was much more sensitive to the effects of the iron-chelating agents Desferal and EDTA. The cell pellets from the MQ-580 cells were much darker in color than the pellets from the wild-type cells or hydroxyurea-resistant cells. The supernatant fraction from the MQ-580 cells after-SDS-PAGE showed the appearance of a strong Coomassie blue-staining band at 50 kDA that was not apparent in either the wild-type or hydroxyurea-resistant cells. This new resistant cell line offers an opportunity to explore differences in resistance mechanisms of drugs (e.g. MAIQ and hydroxyurea) that are directed at the same subunit of ribonucleotide reductase.

The nitric oxide synthase inhibitor L-NAME reduces inhibitory components of somato-vesical parasympathetic reflexes in the rat

Reflex discharges of pelvic postganglionic parasympathetic efferent fibers on the bladder surface induced by afferent volleys in the hindlimb nerve have been recorded in anesthetized rats, and the effects of the nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME) on the reflex discharges have been investigated. Single electrical stimulation of the tibial nerve at intensities supramaximal for excitation of A- and C-afferents evoked a reflex discharge in the postganglionic parasympathetic efferents with four distinct components, i.e., two inhibitory components with latencies of 49 and 203 ms, respectively, and two excitatory components with latencies of 126 and 308 ms, respectively. These reflexes could be observed when the bladder was expanded, but not markedly when the bladder was empty. Intravenous administration of L-NAME resulted in (a) a reduction in the level of resting discharge, (b) a reduction in the size of the first inhibitory component, (c) the disappearance of the second inhibitory component and (d) the exaggeration of the late excitatory component. Intracisternal injection of L-NAME caused changes similar to those observed following intravenous injection. The results suggest that inhibitory components of the somato-pelvic parasympathetic reflex are mediated by pathways that utilize nitric oxide as a neurotransmitter or neuromodulator at the level of the brainstem.

[Pneumothorax from a nasogastric feeding tube]

An 83-year-old woman was admitted to our hospital because of fever and disturbance of consciousness. Pneumonia and multiple organ failure were diagnosed from symptoms, a chest X-ray film, and laboratory findings. With the administration of antibiotics and an antiprotease inhibitor, the pneumonia and multiple organ failure began to resolve, but consciousness remained disturbed. A nasogastric feeding tube was inserted to provide parenteral nutrition. Neither abnormal resistance nor reflex coughing were noted during insertion. Bubbling rales were not heard on auscultation, and a chest X-ray film revealed that the tube had traversed the right bronchial tree, perforated the lung, coiled up in the right pleural vavity, and caused a right pneumothorax. The tube was immediately removed. The pneumothorax was treated with an intercostal drainage tube for 1 day and resolved without further problems. This case shows one of the dangers involved in inserting nasogastric feeding tubes. The medical community should be aware that pulmonary complications may develop after such tubes are inserted in patients with risk factors.

[Middle lobe syndrome--incidence and relationship to atypical mycobacterial pulmonary disease]

We evaluated the incidence of middle lobe syndrome in the Haibara area, and its relationship to atypical mycobacterial infection. Of the 30,588 persons who underwent annual mini-chest roentgenography in 1992 or 1993 or both, 51 (0.17%) had middle lobe syndrome, diagnosed from posteroanterior and lateral chest X-ray films. The incidence was significantly higher in persons over 50 years old than in persons under 50 years old (0.26% vs 0.02%: p < 0.001), and was higher in femals than in males (0.20% vs 0.11%: p = 0.527). Of 16 patients examined by bronchoscopy and computed tomography, 7 showed evidence of cylindrical bronchiectasis, and four had mycobacterium avium complex pulmonary disease presenting as middle lobe syndrome. All four were women who were 51 years of age or older and none had predisposing pulmonary disorders. Computed tomography showed multiple nodular shadows with or without bronchiectasis located in the middle lobe or the lingula. Cavitary lesions were not seen. These results indicate that middle lobe syndrome is not rare, and that infection with mycobacterium avium complex should be considered when multiple nodular shadows are seen in the middle lobe or the lingula.

The role of proteolytic enzymes in the deposition of amyloid proteins

Serum albumin from normal individuals and short-term hemodialysis patients was separated by isoelectric focusing into two bands with pIs of 4.7 (Alb-I) and 4.2 (Alb-II). However, serum albumin from long-term hemodialysis patients with CTS migrated as a single band with a pI of 4.2 (Alb-II). The major constituent of the 100,000 x g supernatant proteins from amyloid tissues that were collected from hemodialysis patients with CTS was Alb-II. Incubation of serum albumin by lysosomal enzymes in vitro caused the modification of Alb-I to Alb-II. The ratio of Alb-I/Alb-II was changed in vivo during the hemodialysis and in in-vitro experiments designed to circulate the sera. Lysosomal enzyme levels such as acid phosphatase, glucosidase, glucuronidase and dipeptidyl aminopeptidase in the serum of hemodialysis patients were higher than those of normal individuals. Plasma levels of acid phosphatase and cathepsin L were elevated during hemodialysis. These results suggest that the conformational change of serum albumin by proteolytic modification during hemodialysis may be involved in the hemodialysis-associated amyloidosis.

Evaluation of human skin irritation by carboxylic acids, alcohols, esters and aldehydes, with nitrocellulose-replica method and closed patch testing

Closed patch testing and the nitrocellulose-replica method are performed as useful clinical methods for the evaluation of human skin irritation by cosmetics and topical medicaments. Comparison of the sensitivity between microscopic scoring by nitrocellulose-replica method and visual scoring by closed patch test in the detection of skin irritation, however, has not been well studied with statistical analysis. Here, we evaluated human skin irritation by carboxylic acids, alcohols, esters and aldehydes, with different chain length (C8-C18), using both methods. The results of closed patch testing showed that, although the score of skin irritation for carboxylic acids (C8, C12), alcohols (C8) and aldehydes (C8), tested at a concentration of 0.5 m-2.0 m, significantly increased with increasing concentration of the test compounds, ester compounds scarcely caused any irritation on the surface of the skin occluded. In addition, an increase of carbon chain length in the test compounds made it impossible to detect skin irritation. In contrast, the nitrocellulose-replica method could evaluate skin reactions against very weak irritants that gave no macroscopic alterations on the skin surface in the closed patch test. However, the scoring system is somewhat subjective and should be improved to make the analysis more objective.