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Biomedical subjects

R Malhotra

Publications and source records attributed to R Malhotra.

At least 163 records · Page 9Linked to original sources
PubMed1992

Primary pyogenic abscess of the psoas muscle.

Nine children who were less than nine years old and had a primary pyogenic abscess of the psoas muscle were treated in a five-year period. This rare lesion often simulated septic arthritis of the hip. Ultrasonography was found to be the most reliable and easily performed diagnostic study. Because of the rarity of the lesion, the diagnosis requires a high index of suspicion. The best treatment is early operative drainage and administration of systemic antibiotics.

Child↗
PubMed1991

PACAP-38, a novel peptide from ovine hypothalamus, is a potent modulator of amylase release from dispersed acini from rat pancreas.

Despite studies indicating the presence of specific pancreatic acinar receptors for PACAP-38, a peptide that was recently isolated from ovine hypothalamus, the actions of the new peptide on pancreatic enzyme secretion have not been examined. The present study demonstrates that in terms of cAMP production and amylase release from dispersed acini from rat pancreatic acini, PACAP-38 and an N-terminal fragment, PACAP-27, have the same potency and efficacy as vasoactive intestinal peptide (VIP). As with VIP, these actions are potentiated by adding an inhibitor of cyclic nucleotide phosphodiesterase, and combination of PACAP-38 with bombesin, CCK-8, carbachol or the calcium ionophore A23187 results in 2-fold augmentation of the secretory actions of these agents. Inhibition of PACAP-38-induced cAMP production and amylase release by two VIP-receptor antagonists indicates that the secretory effects of PACAP-38 are mediated by interaction with VIP receptors. PACAP-38, a new brain-gut peptide, may be a physiological modulator of pancreatic enzyme secretion.

1-Methyl-3-isobutylxanthine↗
PubMed1991

Scabies presenting as bullous pemphigoid-like eruption.

Several diseases, at times, may be confused with scabies. We report the diagnosis and treatment of scabies in two patients. Their eruptions recurred and persisted and eventually developed blisters. The skin biopsy specimens submitted for light microscopy and immunofluorescence were considered to be consistent with bullous pemphigoid. Both patients were treated successfully with lindane and remained disease free for up to 6 months of follow-up.

Aged↗
PubMed1991

A new model of nephrolithiasis involving tubular dysfunction/injury.

To better understand the pathogenesis of nephrolithiasis, we developed a new animal model that closely mimics human calcium oxalate stone disease. Rats were treated with a regimen that combines moderate hyperoxaluria (produced by 10 days of feeding with 3% ammonium oxalate) with mild proximal tubular injury/dysfunction (produced by 8 daily injections of gentamicin sulfate -40 mg./kg.). This combined treatment caused a marked increase in the incidence of calcium oxalate crystals and stones over that seen in animals treated with oxalate or gentamicin alone. Using a semiquantitative scoring system for estimating the abundance of crystals in coronal sections of kidneys, we found that 63% of animals receiving gentamicin plus oxalate showed "moderate" numbers of crystal, as compared to 8% of animals receiving oxalate alone; and the majority of the crystals occurred in the papilla, a pattern similar to that seen in human stone disease. Untreated rats and rats treated with gentamicin alone did not exhibit calcium oxalate crystals or stones. Despite the abundance of crystals and stones, animals receiving gentamicin plus oxalate retained relatively normal renal function as judged by creatinine clearance. Thus, the model has several advantages over preexisting models of nephrolithiasis. Crystal and stone deposition develop rapidly (within 14 days). The pattern of deposition resembles that seen in human stone disease and renal function remains relatively normal. These findings indicate that this model of nephrolithiasis may prove useful for studies of the pathogenesis of stone disease. Moreover, they suggest that renal tubular injury and/or dysfunction may produce conditions conducive to the formation and growth of calcium oxalate stones.

Animals↗
PubMed1990

Human leukocyte C1q receptor binds other soluble proteins with collagen domains.

A receptor binding to the C1q subcomponent of complement has been reported by many workers. In this paper we report for the first time that C1q receptor binds not only to C1q, but also to three other structurally similar ligands, namely mannan binding protein (MBP), conglutinin, and lung surfactant protein (SP-A). All these ligands have been reported to enhance removal of species bound to their globular domain from blood (MBP, conglutinin, C1q) or lung (SP-A) through phagocytosis. One of the possible roles for ligand-receptor binding may be initiation of phagocytosis.

Binding, Competitive↗
PubMed1990

Syringosquamous metaplasia. A distinctive eruption in patients receiving chemotherapy.

Squamous metaplasia of the upper portion of the sweat ducts has been observed in four patients who received chemotherapy; two patients with acute myelogenous leukemia, one patient with testicular carcinoma, and one patient with anaplastic carcinoma of the lung. This change is different (but perhaps related) from what is described in neutrophilic eccrine hidradenitis in patients with acute myelogenous leukemia and other tumors after chemotherapy. Syringosquamous metaplasia may be confused with well differentiated squamous cell carcinoma histologically.

Adult↗
PubMed1989

Chemical and hydrodynamic characterization of the human leucocyte receptor for complement subcomponent C1q.

A procedure for preparation of the receptor for complement subcomponent Clq from human tonsil lymphocytes and the monocytic cell line U937 was developed. The procedure is suitable for isolation of several hundred micrograms of the receptor, Clq-R, and has yielded sufficient material for chemical and hydrodynamic characterization. Clq-R from tonsil lymphocytes behaves identically with that from U937 cells. Clq-R has a monomer Mr of 56,000, and is an acidic glycoprotein containing about 17% carbohydrate. The polypeptide chain length is estimated to be 416-448 amino acid residues, with two or three sites for N-linked glycosylation. Detergent-solubilized Clq-R exists as an elongated dimer (f/fo = 1.8), and does not bind a significant weight of detergent. The radioiodinated isolated receptor binds specifically and saturably to solid-phase Clq, but not to collagen, IgG, bovine serum albumin or complement component C3.

Carrier Proteins↗
PubMed1989

Transient acute severe aortic regurgitation complicating balloon aortic valvuloplasty.

Transient, acute severe aortic regurgitation documented by hemodynamic and Doppler-echocardiographic assessment was observed in an elderly woman immediately following balloon aortic valvuloplasty for critical aortic stenosis. Aortic regurgitation responded to medical therapy and resolved within 24 hr. Potential mechanisms are discussed. We suspect that an oversized balloon to aortic ring area stretched the annulus, separating the valve cusps and resulting in severe regurgitation, which rapidly normalized.

Acute Disease↗
PubMed1989

Midazolam as intravenous sedative for electrocardioversion.

Of the various agents which have been employed for sedation in patients undergoing electrocardioversion, diazepam has had the most extensive use. However, this agent possesses several disadvantages including pain and venous complications at the site of injection and a lower incidence of amnesia. Midazolam, a benzodiazepine derivative, is being increasingly used in general and local anesthesia as well as for procedures requiring conscious sedation, eg, endoscopy. We used intravenous midazolam for conscious sedation in 12 patients undergoing a total of 17 cardioversions. All of the patients experienced amnesia for the procedure and manifested no significant adverse effects. However, serious respiratory failure may occur when intravenous midazolam is used in patients with COPD, debilitated patients, or when the drug is injected rapidly. The use of midazolam should therefore be confined to areas that are able to deal with cardiorespiratory complications. Using guidelines and precautions described here, we encountered no major complications. We conclude that midazolam offers a safe and effective alternative to other agents for conscious sedation in patients undergoing electrocardioversion.

Aged↗
PubMed1989

Protection by desferrioxamine against histopathological changes of the liver in the post-oligaemic phase of clinical haemorrhagic shock in dogs: correlation with improved survival rate and recovery.

Haemorrhagic shock was produced in anaesthetized dogs, by rapid arterial bleeding to mean arterial blood pressure 35 mmHg, and maintained oligaemic for 4 h followed by return of withdrawn blood(ROWB). Dogs were observed for 72 h after ROWB for survival and recovery, and, for histopathological (HP) studies on liver, dogs were sacrificed 2 h after ROWB in non-survival experiments. Desferrioxamine mesylate (25 mg/kg) was administered intra-muscularly at 2,3 and 4 h after blood loss in survival experiments and for HP studies the drug was given at 4 h in one group and at 2 h plus 4 h after blood loss in the second group. With the drug given at 3 or 4 h, survival was 70% and 100% while in the 2 h and the untreated groups it was 50%. Recovery was rapid in all the drug treated survivors, few became conscious within 30 min, showed slight activity by 4-6 h, all were almost normally active by 24 and fully so by 72 h after ROWB. All the 5 control survivors remained unconscious/drowsy upto 24 h; 3 were sluggish at 72 h. By group analysis, serum iron elevation during the oligaemic and at the end of the post-oligaemic phase was less in the drug-treated animals. HP changes of shock in the liver studied by light microscopy, were markedly reduced in severity and were less prevalent in the drug-treated dogs. The salutory effects of desferrioxamine may be due to inhibition of iron catalyzed free-radical production and tissue damage, through its strong iron chelating action. It may have a therapeutic advantage in this emergency condition without the disadvantages of toxicity inherent in prolonged use.

Animals↗
PubMed1989

Angiogenic properties of normal and psoriatic skin associate with epidermis, not dermis.

Psoriasis is a chronic inflammatory and proliferative epidermal skin disease associated with prominent new vessels in the dermis. Heretofore, unresolved was the question which skin element causes stimulation of vessel formation in this lesion: the epidermis, the dermis, vessels themselves, inflammatory cells, and so forth. It has been argued that the dermis by means of its vessels is responsible for the rapid and prominent epidermal growth and that psoriasis is simply a dermal-induced epidermal disease. Recognizing that vascular proliferations do not occur in the absence of an angiogenic stimulus we asked where in psoriatic skin is that angiogenic element found. By using the rabbit cornea angiogenic assay, the vessel-stimulating properties of epidermis and dermis (separated after cold trypsinization overnight), collected from psoriatic-plaque skin and normal skin both nonpsoriatic and psoriatic patients, were measured. The corneas were examined on days 2, 4, 8, 10, and 12 and graded from 1 to 5+ for vessel growth. Psoriatic plaque epidermis revealed a 4 to 5+ stimulus (8 of 12 corneas). Epidermis from normal subjects or from nonlesional psoriatic patient skin also revealed a 4 to 5+ stimulus (3 of 5 and 5 of 8, respectively). In no case was the dermal implant from normal (7 implants) or psoriatic patients (3 implants of lesional skin) angiogenic. The angiogenic activity of epidermis is stable to freezing and boiling. This study indicates that the vessel-stimulating properties of psoriatic and nonpsoriatic skin are associated with the epidermis and that the developing psoriatic lesion may involve complex epidermal to dermal as well as dermal to epidermal signals.

Adult↗
PubMed1988

Primary tuberculous liver abscess associated with the human immunodeficiency virus.

Extrapulmonary tuberculosis has been noted to occur frequently in patients with the Acquired Immunodeficiency Syndrome (AIDS). Tuberculous liver abscesses are rare. The following case report describes a patient with Human Immunodeficiency Virus (HIV) antibody who exemplifies this unusual manifestation of mycobacterial infection.

Adult↗